1029 files changed, 38982 insertions, 32916 deletions

diff --git a/chromium/v8/.gn b/chromium/v8/.gn
index d4ad9599548..a691fa339b0 100644
--- a/chromium/v8/.gn
+++ b/chromium/v8/.gn
@@ -7,11 +7,21 @@ import("//build/dotfile_settings.gni")
 # The location of the build configuration file.
 buildconfig = "//build/config/BUILDCONFIG.gn"
 
+# The python interpreter to use by default. On Windows, this will look
+# for python3.exe and python3.bat.
+script_executable = "python3"
+
 # These are the targets to check headers for by default. The files in targets
 # matching these patterns (see "gn help label_pattern" for format) will have
 # their includes checked for proper dependencies when you run either
 # "gn check" or "gn gen --check".
-check_targets = []
+no_check_targets = [
+  "//:cppgc_base",
+  "//:v8_internal_headers",
+  "//src/inspector:inspector",
+  "//test/cctest:cctest_sources",
+  "//third_party/icu:*",
+]
 
 # These are the list of GN files that run exec_script. This whitelist exists
 # to force additional review for new uses of exec_script, which is strongly
diff --git a/chromium/v8/AUTHORS b/chromium/v8/AUTHORS
index 07644af9d18..15909406cc6 100644
--- a/chromium/v8/AUTHORS
+++ b/chromium/v8/AUTHORS
@@ -84,6 +84,7 @@ Colin Ihrig <cjihrig@gmail.com>
 Cong Zuo <zckevinzc@gmail.com>
 Daniel Andersson <kodandersson@gmail.com>
 Daniel Bevenius <daniel.bevenius@gmail.com>
+Daniel Dromboski <dandromb@gmail.com>
 Daniel James <dnljms@gmail.com>
 David Carlier <devnexen@gmail.com>
 David Manouchehri <david@davidmanouchehri.com>
@@ -211,6 +212,7 @@ Seo Sanghyeon <sanxiyn@gmail.com>
 Shawn Anastasio <shawnanastasio@gmail.com>
 Shawn Presser <shawnpresser@gmail.com>
 Stefan Penner <stefan.penner@gmail.com>
+Stephen Belanger <stephen.belanger@datadoghq.com>
 Sylvestre Ledru <sledru@mozilla.com>
 Taketoshi Aono <brn@b6n.ch>
 Tao Liqiang <taolq@outlook.com>
@@ -228,6 +230,7 @@ Vladimir Krivosheev <develar@gmail.com>
 Vladimir Shutoff <vovan@shutoff.ru>
 Wei Wu <lazyparser@gmail.com>
 Wenlu Wang <kingwenlu@gmail.com>
+Wenyu Zhao <wenyu.zhao@anu.edu.au>
 Wiktor Garbacz <wiktor.garbacz@gmail.com>
 Wouter Vermeiren <wouter.vermeiren@essensium.com>
 Xiaofang Zou <zouxiaofang@iscas.ac.cn>
@@ -239,6 +242,7 @@ Yong Wang <ccyongwang@tencent.com>
 Youfeng Hao <ajihyf@gmail.com>
 Yu Yin <xwafish@gmail.com>
 Yusif Khudhur <yusif.khudhur@gmail.com>
+Yuri Iozzelli <yuri@leaningtech.com>
 Zac Hansen <xaxxon@gmail.com>
 Zeynep Cankara <zeynepcankara402@gmail.com>
 Zhao Jiazhong <kyslie3100@gmail.com>
diff --git a/chromium/v8/BUILD.gn b/chromium/v8/BUILD.gn
index d2bfb6129dc..5e3045bfdc1 100644
--- a/chromium/v8/BUILD.gn
+++ b/chromium/v8/BUILD.gn
@@ -41,7 +41,7 @@ declare_args() {
   v8_enable_future = false
 
   # Sets -DSYSTEM_INSTRUMENTATION. Enables OS-dependent event tracing
-  v8_enable_system_instrumentation = true
+  v8_enable_system_instrumentation = is_win || is_mac
 
   # Sets the GUID for the ETW provider
   v8_etw_guid = ""
@@ -95,8 +95,19 @@ declare_args() {
   v8_win64_unwinding_info = true
 
   # Enable code comments for builtins in the snapshot (impacts performance).
+  # This also enables v8_code_comments.
   v8_enable_snapshot_code_comments = false
 
+  # Allow runtime-enabled code comments (with --code-comments). Enabled by
+  # default in debug builds.
+  # Sets -dV8_CODE_COMMENTS
+  v8_code_comments = ""
+
+  # Allow runtime-enabled debug code (with --debug-code). Enabled by default in
+  # debug builds.
+  # Sets -dV8_ENABLE_DEBUG_CODE
+  v8_enable_debug_code = ""
+
   # Enable native counters from the snapshot (impacts performance, sets
   # -dV8_SNAPSHOT_NATIVE_CODE_COUNTERS).
   # This option will generate extra code in the snapshot to increment counters,
@@ -200,10 +211,6 @@ declare_args() {
                       (is_linux || is_chromeos || is_mac)) ||
                      (v8_current_cpu == "ppc64" && (is_linux || is_chromeos))
 
-  # Temporary flag to allow embedders to update their microtasks scopes
-  # while rolling in a new version of V8.
-  v8_check_microtasks_scopes_consistency = ""
-
   # Enable mitigations for executing untrusted code.
   # Disabled by default on ia32 due to conflicting requirements with embedded
   # builtins. Enabled by default on Android since it doesn't support
@@ -272,6 +279,10 @@ declare_args() {
   # Enable heap reservation of size 4GB. Only possible for 64bit archs.
   cppgc_enable_caged_heap = v8_current_cpu == "x64" || v8_current_cpu == "arm64"
 
+  # Enable verification of live bytes in the marking verifier.
+  # TODO(v8:11785): Enable by default when running with the verifier.
+  cppgc_enable_verify_live_bytes = false
+
   # Enable young generation in cppgc.
   cppgc_enable_young_generation = false
 
@@ -300,6 +311,12 @@ declare_args() {
   # meaning that they are not switched to fast mode.
   # Sets -DV8_DICT_PROPERTY_CONST_TRACKING
   v8_dict_property_const_tracking = false
+
+  # Enable map packing & unpacking (sets -dV8_MAP_PACKING).
+  v8_enable_map_packing = false
+
+  # Allow for JS promise hooks (instead of just C++).
+  v8_allow_javascript_in_promise_hooks = false
 }
 
 # Derived defaults.
@@ -321,9 +338,15 @@ if (v8_enable_test_features == "") {
 if (v8_enable_v8_checks == "") {
   v8_enable_v8_checks = v8_enable_debugging_features
 }
-if (v8_check_microtasks_scopes_consistency == "") {
-  v8_check_microtasks_scopes_consistency =
-      v8_enable_debugging_features || dcheck_always_on
+if (v8_enable_snapshot_code_comments) {
+  assert(v8_code_comments == true || v8_code_comments == "",
+         "v8_enable_snapshot_code_comments conflicts with v8_code_comments.")
+  v8_code_comments = true
+} else if (v8_code_comments == "") {
+  v8_code_comments = v8_enable_debugging_features
+}
+if (v8_enable_debug_code == "") {
+  v8_enable_debug_code = v8_enable_debugging_features
 }
 if (v8_enable_snapshot_native_code_counters == "") {
   v8_enable_snapshot_native_code_counters = v8_enable_debugging_features
@@ -333,7 +356,7 @@ if (v8_enable_pointer_compression == "") {
       v8_current_cpu == "arm64" || v8_current_cpu == "x64"
 }
 if (v8_enable_pointer_compression_shared_cage == "") {
-  v8_enable_pointer_compression_shared_cage = false
+  v8_enable_pointer_compression_shared_cage = v8_enable_pointer_compression
 }
 if (v8_enable_fast_torque == "") {
   v8_enable_fast_torque = v8_enable_fast_mksnapshot
@@ -357,6 +380,13 @@ if (v8_enable_atomic_object_field_writes == "") {
 if (v8_enable_atomic_marking_state == "") {
   v8_enable_atomic_marking_state = v8_enable_concurrent_marking
 }
+if (v8_enable_third_party_heap) {
+  v8_disable_write_barriers = true
+  v8_enable_single_generation = true
+  v8_enable_shared_ro_heap = false
+  v8_enable_pointer_compression = false
+  v8_enable_pointer_compression_shared_cage = false
+}
 assert(!v8_enable_concurrent_marking || v8_enable_atomic_object_field_writes,
        "Concurrent marking requires atomic object field writes.")
 assert(!v8_enable_concurrent_marking || v8_enable_atomic_marking_state,
@@ -386,7 +416,8 @@ if (v8_enable_short_builtin_calls &&
   v8_enable_short_builtin_calls = false
 }
 if (v8_enable_shared_ro_heap == "") {
-  v8_enable_shared_ro_heap = !v8_enable_pointer_compression
+  v8_enable_shared_ro_heap = !v8_enable_pointer_compression ||
+                             v8_enable_pointer_compression_shared_cage
 }
 
 assert(!v8_disable_write_barriers || v8_enable_single_generation,
@@ -398,15 +429,18 @@ assert(v8_current_cpu != "x86" || !v8_untrusted_code_mitigations,
 assert(v8_current_cpu == "arm64" || !v8_control_flow_integrity,
        "Control-flow integrity is only supported on arm64")
 
-if (v8_enable_shared_ro_heap && v8_enable_pointer_compression) {
+if (v8_enable_shared_ro_heap && v8_enable_pointer_compression &&
+    !v8_enable_pointer_compression_shared_cage) {
   assert(
       is_linux || is_chromeos || is_android,
       "Sharing read-only heap with pointer compression is only supported on Linux or Android")
 }
 
-assert(
-    !v8_enable_pointer_compression_shared_cage || !v8_enable_shared_ro_heap,
-    "Sharing read-only heap is not yet supported when sharing a pointer compression cage")
+assert(!v8_enable_map_packing || !v8_enable_pointer_compression,
+       "Map packing does not support pointer compression")
+
+assert(!v8_enable_map_packing || v8_current_cpu == "x64",
+       "Map packing is only supported on x64")
 
 assert(!v8_use_multi_snapshots || !v8_control_flow_integrity,
        "Control-flow integrity does not support multisnapshots")
@@ -418,6 +452,10 @@ assert(
     !v8_enable_pointer_compression_shared_cage || v8_enable_pointer_compression,
     "Can't share a pointer compression cage if pointers aren't compressed")
 
+assert(!v8_enable_pointer_compression_shared_cage || v8_current_cpu == "x64" ||
+           v8_current_cpu == "arm64",
+       "Sharing a pointer compression cage is only supported on x64 and arm64")
+
 assert(!v8_enable_unconditional_write_barriers || !v8_disable_write_barriers,
        "Write barriers can't be both enabled and disabled")
 
@@ -566,6 +604,7 @@ external_v8_defines = [
   "V8_IMMINENT_DEPRECATION_WARNINGS",
   "V8_NO_ARGUMENTS_ADAPTOR",
   "V8_USE_PERFETTO",
+  "V8_MAP_PACKING",
 ]
 
 enabled_external_v8_defines = []
@@ -575,11 +614,11 @@ if (v8_enable_v8_checks) {
 }
 if (v8_enable_pointer_compression) {
   enabled_external_v8_defines += [ "V8_COMPRESS_POINTERS" ]
-}
-if (v8_enable_pointer_compression_shared_cage) {
-  enabled_external_v8_defines += [ "V8_COMPRESS_POINTERS_IN_SHARED_CAGE" ]
-} else if (v8_enable_pointer_compression) {
-  enabled_external_v8_defines += [ "V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE" ]
+  if (v8_enable_pointer_compression_shared_cage) {
+    enabled_external_v8_defines += [ "V8_COMPRESS_POINTERS_IN_SHARED_CAGE" ]
+  } else {
+    enabled_external_v8_defines += [ "V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE" ]
+  }
 }
 if (v8_enable_pointer_compression || v8_enable_31bit_smis_on_64bit_arch) {
   enabled_external_v8_defines += [ "V8_31BIT_SMIS_ON_64BIT_ARCH" ]
@@ -599,6 +638,9 @@ if (v8_imminent_deprecation_warnings) {
 if (v8_use_perfetto) {
   enabled_external_v8_defines += [ "V8_USE_PERFETTO" ]
 }
+if (v8_enable_map_packing) {
+  enabled_external_v8_defines += [ "V8_MAP_PACKING" ]
+}
 
 disabled_external_v8_defines = external_v8_defines - enabled_external_v8_defines
 
@@ -665,6 +707,10 @@ config("features") {
     ":cppgc_header_features",
   ]
 
+  if (cppgc_enable_verify_live_bytes) {
+    defines += [ "CPPGC_VERIFY_LIVE_BYTES" ]
+  }
+
   if (v8_embedder_string != "") {
     defines += [ "V8_EMBEDDER_STRING=\"$v8_embedder_string\"" ]
   }
@@ -729,6 +775,12 @@ config("features") {
   if (v8_enable_handle_zapping) {
     defines += [ "ENABLE_HANDLE_ZAPPING" ]
   }
+  if (v8_code_comments == true) {
+    defines += [ "V8_CODE_COMMENTS" ]
+  }
+  if (v8_enable_debug_code) {
+    defines += [ "V8_ENABLE_DEBUG_CODE" ]
+  }
   if (v8_enable_snapshot_native_code_counters) {
     defines += [ "V8_SNAPSHOT_NATIVE_CODE_COUNTERS" ]
   }
@@ -756,9 +808,6 @@ config("features") {
   if (v8_enable_lazy_source_positions) {
     defines += [ "V8_ENABLE_LAZY_SOURCE_POSITIONS" ]
   }
-  if (v8_check_microtasks_scopes_consistency) {
-    defines += [ "V8_CHECK_MICROTASKS_SCOPES_CONSISTENCY" ]
-  }
   if (v8_use_multi_snapshots) {
     defines += [ "V8_MULTI_SNAPSHOTS" ]
   }
@@ -807,6 +856,9 @@ config("features") {
   if (v8_dict_property_const_tracking) {
     defines += [ "V8_DICT_PROPERTY_CONST_TRACKING" ]
   }
+  if (v8_allow_javascript_in_promise_hooks) {
+    defines += [ "V8_ALLOW_JAVASCRIPT_IN_PROMISE_HOOKS" ]
+  }
 }
 
 config("toolchain") {
@@ -1038,6 +1090,10 @@ config("toolchain") {
     defines += [ "ENABLE_VERIFY_CSA" ]
   }
 
+  if (v8_enable_runtime_call_stats) {
+    defines += [ "V8_RUNTIME_CALL_STATS" ]
+  }
+
   if (!v8_untrusted_code_mitigations) {
     defines += [ "DISABLE_UNTRUSTED_CODE_MITIGATIONS" ]
   }
@@ -1244,6 +1300,8 @@ action("postmortem-metadata") {
     "src/objects/map.cc",
     "src/objects/map.h",
     "src/objects/map-inl.h",
+    "src/objects/megadom-handler.h",
+    "src/objects/megadom-handler-inl.h",
     "src/objects/name.h",
     "src/objects/name-inl.h",
     "src/objects/objects.h",
@@ -1432,6 +1490,7 @@ torque_files = [
   "src/objects/js-weak-refs.tq",
   "src/objects/literal-objects.tq",
   "src/objects/map.tq",
+  "src/objects/megadom-handler.tq",
   "src/objects/microtask.tq",
   "src/objects/module.tq",
   "src/objects/name.tq",
@@ -1515,44 +1574,37 @@ template("run_torque") {
 
     destination_folder = "$target_gen_dir/torque-generated$suffix"
 
-    files = [
-      "$target_gen_dir/torque-generated/bit-fields.h",
-      "$target_gen_dir/torque-generated/builtin-definitions.h",
-      "$target_gen_dir/torque-generated/class-debug-readers.cc",
-      "$target_gen_dir/torque-generated/class-debug-readers.h",
-      "$target_gen_dir/torque-generated/class-forward-declarations.h",
-      "$target_gen_dir/torque-generated/class-verifiers.cc",
-      "$target_gen_dir/torque-generated/class-verifiers.h",
-      "$target_gen_dir/torque-generated/csa-types.h",
-      "$target_gen_dir/torque-generated/debug-macros.cc",
-      "$target_gen_dir/torque-generated/debug-macros.h",
-      "$target_gen_dir/torque-generated/enum-verifiers.cc",
-      "$target_gen_dir/torque-generated/exported-macros-assembler.cc",
-      "$target_gen_dir/torque-generated/exported-macros-assembler.h",
-      "$target_gen_dir/torque-generated/factory.cc",
-      "$target_gen_dir/torque-generated/factory.inc",
-      "$target_gen_dir/torque-generated/field-offsets.h",
-      "$target_gen_dir/torque-generated/instance-types.h",
-      "$target_gen_dir/torque-generated/interface-descriptors.inc",
-      "$target_gen_dir/torque-generated/objects-body-descriptors-inl.inc",
-      "$target_gen_dir/torque-generated/objects-printer.cc",
+    outputs = [
+      "$destination_folder/bit-fields.h",
+      "$destination_folder/builtin-definitions.h",
+      "$destination_folder/class-debug-readers.cc",
+      "$destination_folder/class-debug-readers.h",
+      "$destination_folder/class-forward-declarations.h",
+      "$destination_folder/class-verifiers.cc",
+      "$destination_folder/class-verifiers.h",
+      "$destination_folder/csa-types.h",
+      "$destination_folder/debug-macros.cc",
+      "$destination_folder/debug-macros.h",
+      "$destination_folder/enum-verifiers.cc",
+      "$destination_folder/exported-macros-assembler.cc",
+      "$destination_folder/exported-macros-assembler.h",
+      "$destination_folder/factory.cc",
+      "$destination_folder/factory.inc",
+      "$destination_folder/field-offsets.h",
+      "$destination_folder/instance-types.h",
+      "$destination_folder/interface-descriptors.inc",
+      "$destination_folder/objects-body-descriptors-inl.inc",
+      "$destination_folder/objects-printer.cc",
     ]
 
-    outputs = []
-    foreach(file, files) {
-      outputs += [ string_replace(file,
-                                  "$target_gen_dir/torque-generated",
-                                  destination_folder) ]
-    }
-
     foreach(file, torque_files) {
       filetq = string_replace(file, ".tq", "-tq")
       outputs += [
-        "$target_gen_dir/torque-generated/$filetq-csa.cc",
-        "$target_gen_dir/torque-generated/$filetq-csa.h",
-        "$target_gen_dir/torque-generated/$filetq-inl.inc",
-        "$target_gen_dir/torque-generated/$filetq.cc",
-        "$target_gen_dir/torque-generated/$filetq.inc",
+        "$destination_folder/$filetq-csa.cc",
+        "$destination_folder/$filetq-csa.h",
+        "$destination_folder/$filetq-inl.inc",
+        "$destination_folder/$filetq.cc",
+        "$destination_folder/$filetq.inc",
       ]
     }
 
@@ -1892,11 +1944,16 @@ action("v8_dump_build_config") {
     "v8_enable_atomic_object_field_writes=" +
         "$v8_enable_atomic_object_field_writes",
     "v8_enable_concurrent_marking=$v8_enable_concurrent_marking",
+    "v8_enable_single_generation=$v8_enable_single_generation",
     "v8_enable_i18n_support=$v8_enable_i18n_support",
     "v8_enable_verify_predictable=$v8_enable_verify_predictable",
     "v8_enable_verify_csa=$v8_enable_verify_csa",
     "v8_enable_lite_mode=$v8_enable_lite_mode",
+    "v8_enable_runtime_call_stats=$v8_enable_runtime_call_stats",
     "v8_enable_pointer_compression=$v8_enable_pointer_compression",
+    "v8_enable_pointer_compression_shared_cage=" +
+        "$v8_enable_pointer_compression_shared_cage",
+    "v8_enable_third_party_heap=$v8_enable_third_party_heap",
     "v8_enable_webassembly=$v8_enable_webassembly",
     "v8_control_flow_integrity=$v8_control_flow_integrity",
     "v8_target_cpu=\"$v8_target_cpu\"",
@@ -1918,7 +1975,10 @@ action("v8_dump_build_config") {
 v8_source_set("v8_snapshot") {
   visibility = [ ":*" ]  # Targets in this file can depend on this.
 
-  deps = []
+  deps = [
+    ":v8_internal_headers",
+    ":v8_libbase",
+  ]
   public_deps = [
     # This should be public so downstream targets can declare the snapshot
     # output file as their inputs.
@@ -2000,7 +2060,6 @@ v8_source_set("v8_initializers") {
     "src/builtins/builtins-conversion-gen.cc",
     "src/builtins/builtins-data-view-gen.h",
     "src/builtins/builtins-date-gen.cc",
-    "src/builtins/builtins-debug-gen.cc",
     "src/builtins/builtins-generator-gen.cc",
     "src/builtins/builtins-global-gen.cc",
     "src/builtins/builtins-handler-gen.cc",
@@ -2226,9 +2285,8 @@ if (v8_generate_external_defines_header) {
 v8_header_set("v8_shared_internal_headers") {
   visibility = [
     ":*",
-    "test/cctest:*",
-    "test/unittests:*",
-    "tools/debug_helper/:*",
+    "test/*",
+    "tools/*",
   ]
   configs = [ ":internal_config" ]
 
@@ -2245,7 +2303,10 @@ v8_header_set("v8_shared_internal_headers") {
 }
 
 v8_header_set("v8_flags") {
-  visibility = [ ":*" ]
+  visibility = [
+    ":*",
+    "tools/*",
+  ]
 
   configs = [ ":internal_config" ]
 
@@ -2273,6 +2334,7 @@ v8_header_set("v8_internal_headers") {
     "src/api/api-arguments-inl.h",
     "src/api/api-arguments.h",
     "src/api/api-inl.h",
+    "src/api/api-macros-undef.h",
     "src/api/api-macros.h",
     "src/api/api-natives.h",
     "src/api/api.h",
@@ -2289,6 +2351,7 @@ v8_header_set("v8_internal_headers") {
     "src/baseline/baseline-assembler-inl.h",
     "src/baseline/baseline-assembler.h",
     "src/baseline/baseline-compiler.h",
+    "src/baseline/baseline-osr-inl.h",
     "src/baseline/baseline.h",
     "src/baseline/bytecode-offset-iterator.h",
     "src/builtins/accessors.h",
@@ -2321,6 +2384,7 @@ v8_header_set("v8_internal_headers") {
     "src/codegen/external-reference.h",
     "src/codegen/flush-instruction-cache.h",
     "src/codegen/handler-table.h",
+    "src/codegen/interface-descriptors-inl.h",
     "src/codegen/interface-descriptors.h",
     "src/codegen/label.h",
     "src/codegen/machine-type.h",
@@ -2382,6 +2446,7 @@ v8_header_set("v8_internal_headers") {
     "src/compiler/common-operator-reducer.h",
     "src/compiler/common-operator.h",
     "src/compiler/compilation-dependencies.h",
+    "src/compiler/compilation-dependency.h",
     "src/compiler/compiler-source-position-table.h",
     "src/compiler/constant-folding-reducer.h",
     "src/compiler/control-equivalence.h",
@@ -2448,18 +2513,17 @@ v8_header_set("v8_internal_headers") {
     "src/compiler/persistent-map.h",
     "src/compiler/pipeline-statistics.h",
     "src/compiler/pipeline.h",
+    "src/compiler/processed-feedback.h",
     "src/compiler/property-access-builder.h",
     "src/compiler/raw-machine-assembler.h",
     "src/compiler/redundancy-elimination.h",
     "src/compiler/refs-map.h",
     "src/compiler/representation-change.h",
     "src/compiler/schedule.h",
-    "src/compiler/scheduled-machine-lowering.h",
     "src/compiler/scheduler.h",
     "src/compiler/select-lowering.h",
     "src/compiler/serializer-for-background-compilation.h",
     "src/compiler/serializer-hints.h",
-    "src/compiler/simd-scalar-lowering.h",
     "src/compiler/simplified-lowering.h",
     "src/compiler/simplified-operator-reducer.h",
     "src/compiler/simplified-operator.h",
@@ -2517,6 +2581,7 @@ v8_header_set("v8_internal_headers") {
     "src/execution/interrupts-scope.h",
     "src/execution/isolate-data.h",
     "src/execution/isolate-inl.h",
+    "src/execution/isolate-utils-inl.h",
     "src/execution/isolate-utils.h",
     "src/execution/isolate.h",
     "src/execution/local-isolate-inl.h",
@@ -2557,6 +2622,7 @@ v8_header_set("v8_internal_headers") {
     "src/heap/base-space.h",
     "src/heap/basic-memory-chunk.h",
     "src/heap/code-object-registry.h",
+    "src/heap/code-range.h",
     "src/heap/code-stats.h",
     "src/heap/collection-barrier.h",
     "src/heap/combined-heap.h",
@@ -2592,11 +2658,13 @@ v8_header_set("v8_internal_headers") {
     "src/heap/list.h",
     "src/heap/local-allocator-inl.h",
     "src/heap/local-allocator.h",
+    "src/heap/local-factory-inl.h",
     "src/heap/local-factory.h",
     "src/heap/local-heap-inl.h",
     "src/heap/local-heap.h",
     "src/heap/mark-compact-inl.h",
     "src/heap/mark-compact.h",
+    "src/heap/marking-barrier-inl.h",
     "src/heap/marking-barrier.h",
     "src/heap/marking-visitor-inl.h",
     "src/heap/marking-visitor.h",
@@ -2679,13 +2747,13 @@ v8_header_set("v8_internal_headers") {
     "src/libsampler/sampler.h",
     "src/logging/code-events.h",
     "src/logging/counters-definitions.h",
-    "src/logging/counters-inl.h",
     "src/logging/counters.h",
     "src/logging/local-logger.h",
     "src/logging/log-inl.h",
     "src/logging/log-utils.h",
     "src/logging/log.h",
     "src/logging/metrics.h",
+    "src/logging/runtime-call-stats.h",
     "src/logging/tracing-flags.h",
     "src/numbers/bignum-dtoa.h",
     "src/numbers/bignum.h",
@@ -2766,6 +2834,7 @@ v8_header_set("v8_internal_headers") {
     "src/objects/js-array-inl.h",
     "src/objects/js-array.h",
     "src/objects/js-collection-inl.h",
+    "src/objects/js-collection-iterator-inl.h",
     "src/objects/js-collection-iterator.h",
     "src/objects/js-collection.h",
     "src/objects/js-function-inl.h",
@@ -2782,6 +2851,8 @@ v8_header_set("v8_internal_headers") {
     "src/objects/js-regexp-string-iterator-inl.h",
     "src/objects/js-regexp-string-iterator.h",
     "src/objects/js-regexp.h",
+    "src/objects/js-segments-inl.h",
+    "src/objects/js-segments.h",
     "src/objects/js-weak-refs-inl.h",
     "src/objects/js-weak-refs.h",
     "src/objects/keys.h",
@@ -2797,6 +2868,8 @@ v8_header_set("v8_internal_headers") {
     "src/objects/map.h",
     "src/objects/maybe-object-inl.h",
     "src/objects/maybe-object.h",
+    "src/objects/megadom-handler-inl.h",
+    "src/objects/megadom-handler.h",
     "src/objects/microtask-inl.h",
     "src/objects/microtask.h",
     "src/objects/module-inl.h",
@@ -2831,6 +2904,7 @@ v8_header_set("v8_internal_headers") {
     "src/objects/property.h",
     "src/objects/prototype-info-inl.h",
     "src/objects/prototype-info.h",
+    "src/objects/prototype-inl.h",
     "src/objects/prototype.h",
     "src/objects/regexp-match-info.h",
     "src/objects/scope-info-inl.h",
@@ -2842,6 +2916,7 @@ v8_header_set("v8_internal_headers") {
     "src/objects/slots-atomic-inl.h",
     "src/objects/slots-inl.h",
     "src/objects/slots.h",
+    "src/objects/source-text-module-inl.h",
     "src/objects/source-text-module.h",
     "src/objects/stack-frame-info-inl.h",
     "src/objects/stack-frame-info.h",
@@ -2880,6 +2955,7 @@ v8_header_set("v8_internal_headers") {
     "src/parsing/expression-scope.h",
     "src/parsing/func-name-inferrer.h",
     "src/parsing/import-assertions.h",
+    "src/parsing/keywords-gen.h",
     "src/parsing/literal-buffer.h",
     "src/parsing/parse-info.h",
     "src/parsing/parser-base.h",
@@ -2892,6 +2968,7 @@ v8_header_set("v8_internal_headers") {
     "src/parsing/preparser.h",
     "src/parsing/rewriter.h",
     "src/parsing/scanner-character-streams.h",
+    "src/parsing/scanner-inl.h",
     "src/parsing/scanner.h",
     "src/parsing/token.h",
     "src/profiler/allocation-tracker.h",
@@ -2939,10 +3016,6 @@ v8_header_set("v8_internal_headers") {
     "src/roots/roots.h",
     "src/runtime/runtime-utils.h",
     "src/runtime/runtime.h",
-    "src/sanitizer/asan.h",
-    "src/sanitizer/lsan-page-allocator.h",
-    "src/sanitizer/msan.h",
-    "src/sanitizer/tsan.h",
     "src/snapshot/code-serializer.h",
     "src/snapshot/context-deserializer.h",
     "src/snapshot/context-serializer.h",
@@ -2980,6 +3053,7 @@ v8_header_set("v8_internal_headers") {
     "src/tasks/task-utils.h",
     "src/third_party/siphash/halfsiphash.h",
     "src/third_party/utf8-decoder/utf8-decoder.h",
+    "src/torque/runtime-macro-shims.h",
     "src/tracing/trace-event.h",
     "src/tracing/traced-value.h",
     "src/tracing/tracing-category-observer.h",
@@ -3046,6 +3120,7 @@ v8_header_set("v8_internal_headers") {
       "src/wasm/jump-table-assembler.h",
       "src/wasm/leb-helper.h",
       "src/wasm/local-decl-encoder.h",
+      "src/wasm/memory-protection-key.h",
       "src/wasm/memory-tracing.h",
       "src/wasm/module-compiler.h",
       "src/wasm/module-decoder.h",
@@ -3063,6 +3138,7 @@ v8_header_set("v8_internal_headers") {
       "src/wasm/wasm-feature-flags.h",
       "src/wasm/wasm-features.h",
       "src/wasm/wasm-import-wrapper-cache.h",
+      "src/wasm/wasm-init-expr.h",
       "src/wasm/wasm-js.h",
       "src/wasm/wasm-linkage.h",
       "src/wasm/wasm-module-builder.h",
@@ -3070,6 +3146,7 @@ v8_header_set("v8_internal_headers") {
       "src/wasm/wasm-module.h",
       "src/wasm/wasm-objects-inl.h",
       "src/wasm/wasm-objects.h",
+      "src/wasm/wasm-opcodes-inl.h",
       "src/wasm/wasm-opcodes.h",
       "src/wasm/wasm-result.h",
       "src/wasm/wasm-serialization.h",
@@ -3140,6 +3217,7 @@ v8_header_set("v8_internal_headers") {
       "src/codegen/ia32/assembler-ia32-inl.h",
       "src/codegen/ia32/assembler-ia32.h",
       "src/codegen/ia32/constants-ia32.h",
+      "src/codegen/ia32/interface-descriptors-ia32-inl.h",
       "src/codegen/ia32/macro-assembler-ia32.h",
       "src/codegen/ia32/register-ia32.h",
       "src/codegen/ia32/sse-instr.h",
@@ -3158,6 +3236,7 @@ v8_header_set("v8_internal_headers") {
       "src/codegen/x64/assembler-x64.h",
       "src/codegen/x64/constants-x64.h",
       "src/codegen/x64/fma-instr.h",
+      "src/codegen/x64/interface-descriptors-x64-inl.h",
       "src/codegen/x64/macro-assembler-x64.h",
       "src/codegen/x64/register-x64.h",
       "src/codegen/x64/sse-instr.h",
@@ -3187,6 +3266,7 @@ v8_header_set("v8_internal_headers") {
       "src/codegen/arm/assembler-arm-inl.h",
       "src/codegen/arm/assembler-arm.h",
       "src/codegen/arm/constants-arm.h",
+      "src/codegen/arm/interface-descriptors-arm-inl.h",
       "src/codegen/arm/macro-assembler-arm.h",
       "src/codegen/arm/register-arm.h",
       "src/compiler/backend/arm/instruction-codes-arm.h",
@@ -3206,6 +3286,7 @@ v8_header_set("v8_internal_headers") {
       "src/codegen/arm64/decoder-arm64-inl.h",
       "src/codegen/arm64/decoder-arm64.h",
       "src/codegen/arm64/instructions-arm64.h",
+      "src/codegen/arm64/interface-descriptors-arm64-inl.h",
       "src/codegen/arm64/macro-assembler-arm64-inl.h",
       "src/codegen/arm64/macro-assembler-arm64.h",
       "src/codegen/arm64/register-arm64.h",
@@ -3259,11 +3340,10 @@ v8_header_set("v8_internal_headers") {
     ]
   } else if (v8_current_cpu == "ppc") {
     sources += [  ### gcmole(arch:ppc) ###
-      "src/baseline/ppc/baseline-assembler-ppc-inl.h",
-      "src/baseline/ppc/baseline-compiler-ppc-inl.h",
       "src/codegen/ppc/assembler-ppc-inl.h",
       "src/codegen/ppc/assembler-ppc.h",
       "src/codegen/ppc/constants-ppc.h",
+      "src/codegen/ppc/interface-descriptors-ppc-inl.h",
       "src/codegen/ppc/macro-assembler-ppc.h",
       "src/codegen/ppc/register-ppc.h",
       "src/compiler/backend/ppc/instruction-codes-ppc.h",
@@ -3275,11 +3355,10 @@ v8_header_set("v8_internal_headers") {
     ]
   } else if (v8_current_cpu == "ppc64") {
     sources += [  ### gcmole(arch:ppc64) ###
-      "src/baseline/ppc/baseline-assembler-ppc-inl.h",
-      "src/baseline/ppc/baseline-compiler-ppc-inl.h",
       "src/codegen/ppc/assembler-ppc-inl.h",
       "src/codegen/ppc/assembler-ppc.h",
       "src/codegen/ppc/constants-ppc.h",
+      "src/codegen/ppc/interface-descriptors-ppc-inl.h",
       "src/codegen/ppc/macro-assembler-ppc.h",
       "src/codegen/ppc/register-ppc.h",
       "src/compiler/backend/ppc/instruction-codes-ppc.h",
@@ -3296,6 +3375,7 @@ v8_header_set("v8_internal_headers") {
       "src/codegen/s390/assembler-s390-inl.h",
       "src/codegen/s390/assembler-s390.h",
       "src/codegen/s390/constants-s390.h",
+      "src/codegen/s390/interface-descriptors-s390-inl.h",
       "src/codegen/s390/macro-assembler-s390.h",
       "src/codegen/s390/register-s390.h",
       "src/compiler/backend/s390/instruction-codes-s390.h",
@@ -3384,6 +3464,7 @@ v8_compiler_sources = [
   "src/compiler/graph-trimmer.cc",
   "src/compiler/graph-visualizer.cc",
   "src/compiler/graph.cc",
+  "src/compiler/heap-refs.cc",
   "src/compiler/js-call-reducer.cc",
   "src/compiler/js-context-specialization.cc",
   "src/compiler/js-create-lowering.cc",
@@ -3430,7 +3511,6 @@ v8_compiler_sources = [
   "src/compiler/refs-map.cc",
   "src/compiler/representation-change.cc",
   "src/compiler/schedule.cc",
-  "src/compiler/scheduled-machine-lowering.cc",
   "src/compiler/scheduler.cc",
   "src/compiler/select-lowering.cc",
   "src/compiler/serializer-for-background-compilation.cc",
@@ -3452,7 +3532,6 @@ v8_compiler_sources = [
 if (v8_enable_webassembly) {
   v8_compiler_sources += [
     "src/compiler/int64-lowering.cc",
-    "src/compiler/simd-scalar-lowering.cc",
     "src/compiler/wasm-compiler.cc",
   ]
 }
@@ -3676,6 +3755,7 @@ v8_source_set("v8_base_without_compiler") {
     "src/heap/base-space.cc",
     "src/heap/basic-memory-chunk.cc",
     "src/heap/code-object-registry.cc",
+    "src/heap/code-range.cc",
     "src/heap/code-stats.cc",
     "src/heap/collection-barrier.cc",
     "src/heap/combined-heap.cc",
@@ -3763,6 +3843,7 @@ v8_source_set("v8_base_without_compiler") {
     "src/logging/log-utils.cc",
     "src/logging/log.cc",
     "src/logging/metrics.cc",
+    "src/logging/runtime-call-stats.cc",
     "src/logging/tracing-flags.cc",
     "src/numbers/bignum-dtoa.cc",
     "src/numbers/bignum.cc",
@@ -3908,7 +3989,6 @@ v8_source_set("v8_base_without_compiler") {
     "src/runtime/runtime-typedarray.cc",
     "src/runtime/runtime-weak-refs.cc",
     "src/runtime/runtime.cc",
-    "src/sanitizer/lsan-page-allocator.cc",
     "src/snapshot/code-serializer.cc",
     "src/snapshot/context-deserializer.cc",
     "src/snapshot/context-serializer.cc",
@@ -3977,6 +4057,7 @@ v8_source_set("v8_base_without_compiler") {
       "src/wasm/graph-builder-interface.cc",
       "src/wasm/jump-table-assembler.cc",
       "src/wasm/local-decl-encoder.cc",
+      "src/wasm/memory-protection-key.cc",
       "src/wasm/memory-tracing.cc",
       "src/wasm/module-compiler.cc",
       "src/wasm/module-decoder.cc",
@@ -3988,10 +4069,12 @@ v8_source_set("v8_base_without_compiler") {
       "src/wasm/value-type.cc",
       "src/wasm/wasm-code-manager.cc",
       "src/wasm/wasm-debug.cc",
+      "src/wasm/wasm-debug.h",
       "src/wasm/wasm-engine.cc",
       "src/wasm/wasm-external-refs.cc",
       "src/wasm/wasm-features.cc",
       "src/wasm/wasm-import-wrapper-cache.cc",
+      "src/wasm/wasm-init-expr.cc",
       "src/wasm/wasm-js.cc",
       "src/wasm/wasm-module-builder.cc",
       "src/wasm/wasm-module-sourcemap.cc",
@@ -4007,7 +4090,10 @@ v8_source_set("v8_base_without_compiler") {
   if (v8_enable_third_party_heap) {
     sources += v8_third_party_heap_files
   } else {
-    sources += [ "src/heap/third-party/heap-api-stub.cc" ]
+    sources += [
+      "src/heap/third-party/heap-api-stub.cc",
+      "src/heap/third-party/heap-api.h",
+    ]
   }
 
   if (v8_enable_conservative_stack_scanning) {
@@ -4027,24 +4113,15 @@ v8_source_set("v8_base_without_compiler") {
     ]
   }
 
-  if (v8_check_header_includes) {
-    # This file will be generated by tools/generate-header-include-checks.py
-    # if the "check_v8_header_includes" gclient variable is set.
-    import("check-header-includes/sources.gni")
-    sources += check_header_includes_sources
-  }
-
   if (v8_current_cpu == "x86") {
     sources += [  ### gcmole(arch:ia32) ###
       "src/codegen/ia32/assembler-ia32.cc",
       "src/codegen/ia32/cpu-ia32.cc",
-      "src/codegen/ia32/interface-descriptors-ia32.cc",
       "src/codegen/ia32/macro-assembler-ia32.cc",
       "src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.cc",
       "src/compiler/backend/ia32/code-generator-ia32.cc",
       "src/compiler/backend/ia32/instruction-scheduler-ia32.cc",
       "src/compiler/backend/ia32/instruction-selector-ia32.cc",
-      "src/debug/ia32/debug-ia32.cc",
       "src/deoptimizer/ia32/deoptimizer-ia32.cc",
       "src/diagnostics/ia32/disasm-ia32.cc",
       "src/diagnostics/ia32/unwinder-ia32.cc",
@@ -4056,13 +4133,11 @@ v8_source_set("v8_base_without_compiler") {
       "src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.cc",
       "src/codegen/x64/assembler-x64.cc",
       "src/codegen/x64/cpu-x64.cc",
-      "src/codegen/x64/interface-descriptors-x64.cc",
       "src/codegen/x64/macro-assembler-x64.cc",
       "src/compiler/backend/x64/code-generator-x64.cc",
       "src/compiler/backend/x64/instruction-scheduler-x64.cc",
       "src/compiler/backend/x64/instruction-selector-x64.cc",
       "src/compiler/backend/x64/unwinding-info-writer-x64.cc",
-      "src/debug/x64/debug-x64.cc",
       "src/deoptimizer/x64/deoptimizer-x64.cc",
       "src/diagnostics/x64/disasm-x64.cc",
       "src/diagnostics/x64/eh-frame-x64.cc",
@@ -4091,13 +4166,11 @@ v8_source_set("v8_base_without_compiler") {
       "src/codegen/arm/assembler-arm.cc",
       "src/codegen/arm/constants-arm.cc",
       "src/codegen/arm/cpu-arm.cc",
-      "src/codegen/arm/interface-descriptors-arm.cc",
       "src/codegen/arm/macro-assembler-arm.cc",
       "src/compiler/backend/arm/code-generator-arm.cc",
       "src/compiler/backend/arm/instruction-scheduler-arm.cc",
       "src/compiler/backend/arm/instruction-selector-arm.cc",
       "src/compiler/backend/arm/unwinding-info-writer-arm.cc",
-      "src/debug/arm/debug-arm.cc",
       "src/deoptimizer/arm/deoptimizer-arm.cc",
       "src/diagnostics/arm/disasm-arm.cc",
       "src/diagnostics/arm/eh-frame-arm.cc",
@@ -4113,7 +4186,6 @@ v8_source_set("v8_base_without_compiler") {
       "src/codegen/arm64/decoder-arm64.cc",
       "src/codegen/arm64/instructions-arm64-constants.cc",
       "src/codegen/arm64/instructions-arm64.cc",
-      "src/codegen/arm64/interface-descriptors-arm64.cc",
       "src/codegen/arm64/macro-assembler-arm64.cc",
       "src/codegen/arm64/register-arm64.cc",
       "src/codegen/arm64/utils-arm64.cc",
@@ -4121,7 +4193,6 @@ v8_source_set("v8_base_without_compiler") {
       "src/compiler/backend/arm64/instruction-scheduler-arm64.cc",
       "src/compiler/backend/arm64/instruction-selector-arm64.cc",
       "src/compiler/backend/arm64/unwinding-info-writer-arm64.cc",
-      "src/debug/arm64/debug-arm64.cc",
       "src/deoptimizer/arm64/deoptimizer-arm64.cc",
       "src/diagnostics/arm64/disasm-arm64.cc",
       "src/diagnostics/arm64/eh-frame-arm64.cc",
@@ -4146,12 +4217,11 @@ v8_source_set("v8_base_without_compiler") {
       "src/codegen/mips/assembler-mips.cc",
       "src/codegen/mips/constants-mips.cc",
       "src/codegen/mips/cpu-mips.cc",
-      "src/codegen/mips/interface-descriptors-mips.cc",
+      "src/codegen/mips/interface-descriptors-mips-inl.h",
       "src/codegen/mips/macro-assembler-mips.cc",
       "src/compiler/backend/mips/code-generator-mips.cc",
       "src/compiler/backend/mips/instruction-scheduler-mips.cc",
       "src/compiler/backend/mips/instruction-selector-mips.cc",
-      "src/debug/mips/debug-mips.cc",
       "src/deoptimizer/mips/deoptimizer-mips.cc",
       "src/diagnostics/mips/disasm-mips.cc",
       "src/diagnostics/mips/unwinder-mips.cc",
@@ -4164,12 +4234,11 @@ v8_source_set("v8_base_without_compiler") {
       "src/codegen/mips64/assembler-mips64.cc",
       "src/codegen/mips64/constants-mips64.cc",
       "src/codegen/mips64/cpu-mips64.cc",
-      "src/codegen/mips64/interface-descriptors-mips64.cc",
+      "src/codegen/mips64/interface-descriptors-mips64-inl.h",
       "src/codegen/mips64/macro-assembler-mips64.cc",
       "src/compiler/backend/mips64/code-generator-mips64.cc",
       "src/compiler/backend/mips64/instruction-scheduler-mips64.cc",
       "src/compiler/backend/mips64/instruction-selector-mips64.cc",
-      "src/debug/mips64/debug-mips64.cc",
       "src/deoptimizer/mips64/deoptimizer-mips64.cc",
       "src/diagnostics/mips64/disasm-mips64.cc",
       "src/diagnostics/mips64/unwinder-mips64.cc",
@@ -4182,13 +4251,11 @@ v8_source_set("v8_base_without_compiler") {
       "src/codegen/ppc/assembler-ppc.cc",
       "src/codegen/ppc/constants-ppc.cc",
       "src/codegen/ppc/cpu-ppc.cc",
-      "src/codegen/ppc/interface-descriptors-ppc.cc",
       "src/codegen/ppc/macro-assembler-ppc.cc",
       "src/compiler/backend/ppc/code-generator-ppc.cc",
       "src/compiler/backend/ppc/instruction-scheduler-ppc.cc",
       "src/compiler/backend/ppc/instruction-selector-ppc.cc",
       "src/compiler/backend/ppc/unwinding-info-writer-ppc.cc",
-      "src/debug/ppc/debug-ppc.cc",
       "src/deoptimizer/ppc/deoptimizer-ppc.cc",
       "src/diagnostics/ppc/disasm-ppc.cc",
       "src/diagnostics/ppc/eh-frame-ppc.cc",
@@ -4202,13 +4269,11 @@ v8_source_set("v8_base_without_compiler") {
       "src/codegen/ppc/assembler-ppc.cc",
       "src/codegen/ppc/constants-ppc.cc",
       "src/codegen/ppc/cpu-ppc.cc",
-      "src/codegen/ppc/interface-descriptors-ppc.cc",
       "src/codegen/ppc/macro-assembler-ppc.cc",
       "src/compiler/backend/ppc/code-generator-ppc.cc",
       "src/compiler/backend/ppc/instruction-scheduler-ppc.cc",
       "src/compiler/backend/ppc/instruction-selector-ppc.cc",
       "src/compiler/backend/ppc/unwinding-info-writer-ppc.cc",
-      "src/debug/ppc/debug-ppc.cc",
       "src/deoptimizer/ppc/deoptimizer-ppc.cc",
       "src/diagnostics/ppc/disasm-ppc.cc",
       "src/diagnostics/ppc/eh-frame-ppc.cc",
@@ -4222,13 +4287,11 @@ v8_source_set("v8_base_without_compiler") {
       "src/codegen/s390/assembler-s390.cc",
       "src/codegen/s390/constants-s390.cc",
       "src/codegen/s390/cpu-s390.cc",
-      "src/codegen/s390/interface-descriptors-s390.cc",
       "src/codegen/s390/macro-assembler-s390.cc",
       "src/compiler/backend/s390/code-generator-s390.cc",
       "src/compiler/backend/s390/instruction-scheduler-s390.cc",
       "src/compiler/backend/s390/instruction-selector-s390.cc",
       "src/compiler/backend/s390/unwinding-info-writer-s390.cc",
-      "src/debug/s390/debug-s390.cc",
       "src/deoptimizer/s390/deoptimizer-s390.cc",
       "src/diagnostics/s390/disasm-s390.cc",
       "src/diagnostics/s390/eh-frame-s390.cc",
@@ -4239,15 +4302,17 @@ v8_source_set("v8_base_without_compiler") {
     ]
   } else if (v8_current_cpu == "riscv64") {
     sources += [  ### gcmole(arch:riscv64) ###
+      "src/baseline/riscv64/baseline-assembler-riscv64-inl.h",
+      "src/baseline/riscv64/baseline-compiler-riscv64-inl.h",
+      "src/codegen/riscv64/assembler-riscv64-inl.h",
       "src/codegen/riscv64/assembler-riscv64.cc",
       "src/codegen/riscv64/constants-riscv64.cc",
       "src/codegen/riscv64/cpu-riscv64.cc",
-      "src/codegen/riscv64/interface-descriptors-riscv64.cc",
+      "src/codegen/riscv64/interface-descriptors-riscv64-inl.h",
       "src/codegen/riscv64/macro-assembler-riscv64.cc",
       "src/compiler/backend/riscv64/code-generator-riscv64.cc",
       "src/compiler/backend/riscv64/instruction-scheduler-riscv64.cc",
       "src/compiler/backend/riscv64/instruction-selector-riscv64.cc",
-      "src/debug/riscv64/debug-riscv64.cc",
       "src/deoptimizer/riscv64/deoptimizer-riscv64.cc",
       "src/diagnostics/riscv64/disasm-riscv64.cc",
       "src/diagnostics/riscv64/unwinder-riscv64.cc",
@@ -4497,8 +4562,6 @@ v8_component("v8_libbase") {
     "src/base/atomic-utils.h",
     "src/base/atomicops.h",
     "src/base/atomicops_internals_atomicword_compat.h",
-    "src/base/atomicops_internals_portable.h",
-    "src/base/atomicops_internals_std.h",
     "src/base/base-export.h",
     "src/base/bit-field.h",
     "src/base/bits-iterator.h",
@@ -4532,7 +4595,6 @@ v8_component("v8_libbase") {
     "src/base/lazy-instance.h",
     "src/base/logging.cc",
     "src/base/logging.h",
-    "src/base/lsan.h",
     "src/base/macros.h",
     "src/base/memory.h",
     "src/base/once.cc",
@@ -4558,6 +4620,11 @@ v8_component("v8_libbase") {
     "src/base/safe_conversions.h",
     "src/base/safe_conversions_arm_impl.h",
     "src/base/safe_conversions_impl.h",
+    "src/base/sanitizer/asan.h",
+    "src/base/sanitizer/lsan-page-allocator.cc",
+    "src/base/sanitizer/lsan-page-allocator.h",
+    "src/base/sanitizer/lsan.h",
+    "src/base/sanitizer/msan.h",
     "src/base/small-vector.h",
     "src/base/sys-info.cc",
     "src/base/sys-info.h",
@@ -4694,9 +4761,11 @@ v8_component("v8_libbase") {
 
   if (is_tsan && !build_with_chromium) {
     data += [ "tools/sanitizers/tsan_suppressions.txt" ]
+  }
 
-    # llvm-symbolizer uses libstdc++ from the clang package.
-    data += [ "//third_party/llvm-build/Release+Asserts/lib/libstdc++.so.6" ]
+  if (using_sanitizer && !build_with_chromium) {
+    data_deps +=
+        [ "//build/config/clang:llvm-symbolizer_data($host_toolchain)" ]
   }
 
   # TODO(jochen): Add support for qnx, freebsd, openbsd, netbsd, and solaris.
@@ -4720,8 +4789,6 @@ v8_component("v8_libplatform") {
     "src/libplatform/delayed-task-queue.h",
     "src/libplatform/task-queue.cc",
     "src/libplatform/task-queue.h",
-    "src/libplatform/tracing/recorder-default.cc",
-    "src/libplatform/tracing/recorder.h",
     "src/libplatform/tracing/trace-buffer.cc",
     "src/libplatform/tracing/trace-buffer.h",
     "src/libplatform/tracing/trace-config.cc",
@@ -4752,8 +4819,6 @@ v8_component("v8_libplatform") {
   if (v8_use_perfetto) {
     sources -= [
       "//base/trace_event/common/trace_event_common.h",
-      "src/libplatform/tracing/recorder-default.cc",
-      "src/libplatform/tracing/recorder.h",
       "src/libplatform/tracing/trace-buffer.cc",
       "src/libplatform/tracing/trace-buffer.h",
       "src/libplatform/tracing/trace-object.cc",
@@ -4768,9 +4833,15 @@ v8_component("v8_libplatform") {
       # TODO(skyostil): Switch TraceEventListener to protozero.
       "//third_party/perfetto/protos/perfetto/trace:lite",
     ]
-  } else if (is_win) {
-    sources -= [ "src/libplatform/tracing/recorder-default.cc" ]
-    sources += [ "src/libplatform/tracing/recorder-win.cc" ]
+  }
+
+  if (v8_enable_system_instrumentation) {
+    sources += [ "src/libplatform/tracing/recorder.h" ]
+    if (is_mac) {
+      sources += [ "src/libplatform/tracing/recorder-mac.cc" ]
+    } else if (is_win) {
+      sources += [ "src/libplatform/tracing/recorder-win.cc" ]
+    }
   }
 }
 
@@ -4794,8 +4865,13 @@ v8_source_set("fuzzer_support") {
 
 v8_source_set("v8_bigint") {
   sources = [
+    "src/bigint/bigint-internal.cc",
+    "src/bigint/bigint-internal.h",
     "src/bigint/bigint.h",
+    "src/bigint/digit-arithmetic.h",
+    "src/bigint/mul-schoolbook.cc",
     "src/bigint/vector-arithmetic.cc",
+    "src/bigint/vector-arithmetic.h",
   ]
 
   configs = [ ":internal_config" ]
@@ -4807,7 +4883,6 @@ v8_source_set("v8_cppgc_shared") {
     "src/heap/base/stack.h",
     "src/heap/base/worklist.cc",
     "src/heap/base/worklist.h",
-    "src/heap/cppgc/sanitizers.h",
   ]
 
   if (is_clang || !is_win) {
@@ -4954,6 +5029,8 @@ v8_source_set("cppgc_base") {
     "src/heap/cppgc/marking-visitor.h",
     "src/heap/cppgc/marking-worklists.cc",
     "src/heap/cppgc/marking-worklists.h",
+    "src/heap/cppgc/memory.cc",
+    "src/heap/cppgc/memory.h",
     "src/heap/cppgc/metric-recorder.h",
     "src/heap/cppgc/name-trait.cc",
     "src/heap/cppgc/object-allocator.cc",
@@ -4961,6 +5038,7 @@ v8_source_set("cppgc_base") {
     "src/heap/cppgc/object-poisoner.h",
     "src/heap/cppgc/object-size-trait.cc",
     "src/heap/cppgc/object-start-bitmap.h",
+    "src/heap/cppgc/object-view.h",
     "src/heap/cppgc/page-memory.cc",
     "src/heap/cppgc/page-memory.h",
     "src/heap/cppgc/persistent-node.cc",
@@ -5032,6 +5110,35 @@ v8_source_set("cppgc_base_for_testing") {
   public_deps = [ ":cppgc_base" ]
 }
 
+if (v8_check_header_includes) {
+  # This file will be generated by tools/generate-header-include-checks.py
+  # if the "check_v8_header_includes" gclient variable is set.
+  import("check-header-includes/sources.gni")
+  v8_source_set("check_headers") {
+    configs = [ ":internal_config" ]
+    sources = check_header_includes_sources
+
+    # Any rules that contain headers files should be added here either directly
+    # or indirectly by including something that has it transitively in its
+    # public_deps.
+    deps = [
+      ":d8",
+      ":mksnapshot",
+      ":torque_base",
+      ":torque_ls_base",
+      ":v8_base_without_compiler",
+      ":v8_bigint",
+      ":v8_initializers",
+      ":v8_internal_headers",
+      ":v8_libbase",
+      ":v8_maybe_icu",
+      ":wee8",
+      "src/inspector:inspector",
+      "src/inspector:inspector_string_conversions",
+    ]
+  }
+}
+
 ###############################################################################
 # Produce a single static library for embedders
 #
@@ -5284,6 +5391,10 @@ group("gn_all") {
   if (want_v8_shell) {
     deps += [ ":v8_shell" ]
   }
+
+  if (v8_check_header_includes) {
+    deps += [ ":check_headers" ]
+  }
 }
 
 group("v8_python_base") {
@@ -6199,9 +6310,7 @@ if (!build_with_chromium && v8_use_perfetto) {
     configs = [ ":v8_tracing_config" ]
     public_configs = [ "//third_party/perfetto/gn:public_config" ]
     deps = [
-      "//third_party/perfetto/src/trace_processor:export_json",
       "//third_party/perfetto/src/trace_processor:storage_minimal",
-      "//third_party/perfetto/src/tracing:client_api",
       "//third_party/perfetto/src/tracing/core",
 
       # TODO(skyostil): Support non-POSIX platforms.
@@ -6210,5 +6319,11 @@ if (!build_with_chromium && v8_use_perfetto) {
       "//third_party/perfetto/src/tracing:in_process_backend",
       "//third_party/perfetto/src/tracing:platform_impl",
     ]
+
+    public_deps = [
+      "//third_party/perfetto/include/perfetto/trace_processor",
+      "//third_party/perfetto/src/trace_processor:export_json",
+      "//third_party/perfetto/src/tracing:client_api",
+    ]
   }
 }  # if (!build_with_chromium && v8_use_perfetto)
diff --git a/chromium/v8/DEPS b/chromium/v8/DEPS
index b27a4e8e8fa..d3de2c5ddc9 100644
--- a/chromium/v8/DEPS
+++ b/chromium/v8/DEPS
@@ -9,7 +9,6 @@ gclient_gn_args = [
   # TODO(https://crbug.com/1137662, https://crbug.com/1080854)
   # Remove when migration is complete.
   'checkout_fuchsia_for_arm64_host',
-  'checkout_google_benchmark',
 ]
 
 vars = {
@@ -44,13 +43,11 @@ vars = {
   'download_jsfunfuzz': False,
   'check_v8_header_includes': False,
 
-  'checkout_google_benchmark' : False,
-
   # GN CIPD package version.
-  'gn_version': 'git_revision:dba01723a441c358d843a575cb7720d54ddcdf92',
+  'gn_version': 'git_revision:39a87c0b36310bdf06b692c098f199a0d97fc810',
 
   # luci-go CIPD package version.
-  'luci_go': 'git_revision:d6d24b11ecded4d89f3dfd1b2e5a0072a3d4ab15',
+  'luci_go': 'git_revision:22d464e2f8f3bd2bd33f69fe819326d63f881008',
 
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling android_sdk_build-tools_version
@@ -88,15 +85,15 @@ vars = {
 
 deps = {
   'build':
-    Var('chromium_url') + '/chromium/src/build.git' + '@' + '77edba11e25386aa719d4f08c3ce2d8c4f868c15',
+    Var('chromium_url') + '/chromium/src/build.git' + '@' + '4036cf1b17581f5668b487a25e252d56e0321a7f',
   'third_party/depot_tools':
-    Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + '98a52e2e312dd10d7fcf281e322039a6b706b86b',
+    Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + '6b0a611c2c692684f94c0c3629f793feebd16b39',
   'third_party/icu':
-    Var('chromium_url') + '/chromium/deps/icu.git' + '@' + '81d656878ec611cb0b42d52c82e9dae93920d9ba',
+    Var('chromium_url') + '/chromium/deps/icu.git' + '@' + 'f022e298b4f4a782486bb6d5ce6589c998b51fe2',
   'third_party/instrumented_libraries':
-    Var('chromium_url') + '/chromium/src/third_party/instrumented_libraries.git' + '@' + '084aee04777db574038af9e9d33ca5caed577462',
+    Var('chromium_url') + '/chromium/src/third_party/instrumented_libraries.git' + '@' + '4ae2535e8e894c3cd81d46aacdaf151b5df30709',
   'buildtools':
-    Var('chromium_url') + '/chromium/src/buildtools.git' + '@' + '5dbd89c9d9c0b0ff47cefdc2bc421b8c9a1c5a21',
+    Var('chromium_url') + '/chromium/src/buildtools.git' + '@' + '20b1d0fc13ebaa263a1248f08814f523a86e6bed',
   'buildtools/clang_format/script':
     Var('chromium_url') + '/external/github.com/llvm/llvm-project/clang/tools/clang-format.git' + '@' + '99803d74e35962f63a775f29477882afd4d57d94',
   'buildtools/linux64': {
@@ -122,9 +119,9 @@ deps = {
   'buildtools/third_party/libc++/trunk':
     Var('chromium_url') + '/external/github.com/llvm/llvm-project/libcxx.git' + '@' + '8fa87946779682841e21e2da977eccfb6cb3bded',
   'buildtools/third_party/libc++abi/trunk':
-    Var('chromium_url') + '/external/github.com/llvm/llvm-project/libcxxabi.git' + '@' + 'd0f33885a2ffa7d5af74af6065b60eb48e3c70f5',
+    Var('chromium_url') + '/external/github.com/llvm/llvm-project/libcxxabi.git' + '@' + '767de317f97343db64af048e3d198ab8b10fee5d',
   'buildtools/third_party/libunwind/trunk':
-    Var('chromium_url') + '/external/github.com/llvm/llvm-project/libunwind.git' + '@' + '08f35c8514a74817103121def05351186830d4b7',
+    Var('chromium_url') + '/external/github.com/llvm/llvm-project/libunwind.git' + '@' + '7846d256355e40273f7cc192c8f5893e8665a1f9',
   'buildtools/win': {
     'packages': [
       {
@@ -136,7 +133,7 @@ deps = {
     'condition': 'host_os == "win"',
   },
   'base/trace_event/common':
-    Var('chromium_url') + '/chromium/src/base/trace_event/common.git' + '@' + 'cab90cbdaaf4444d67aef6ce3cef09fc5fdeb560',
+    Var('chromium_url') + '/chromium/src/base/trace_event/common.git' + '@' + 'd5bb24e5d9802c8c917fcaa4375d5239a586c168',
   'third_party/android_ndk': {
     'url': Var('chromium_url') + '/android_ndk.git' + '@' + '401019bf85744311b26c88ced255cd53401af8b7',
     'condition': 'checkout_android',
@@ -184,7 +181,7 @@ deps = {
       'dep_type': 'cipd',
   },
   'third_party/catapult': {
-    'url': Var('chromium_url') + '/catapult.git' + '@' + '41a5e5e465ad93d6e08224613d3544334a6278bc',
+    'url': Var('chromium_url') + '/catapult.git' + '@' + 'c1e1d559b46476584ec0eb1d83bd7f43fa5a1b36',
     'condition': 'checkout_android',
   },
   'third_party/colorama/src': {
@@ -196,10 +193,9 @@ deps = {
     'condition': 'checkout_fuchsia',
   },
   'third_party/googletest/src':
-    Var('chromium_url') + '/external/github.com/google/googletest.git' + '@' + '07f4869221012b16b7f9ee685d94856e1fc9f361',
+    Var('chromium_url') + '/external/github.com/google/googletest.git' + '@' + '23ef29555ef4789f555f1ba8c51b4c52975f0907',
   'third_party/google_benchmark/src': {
-    'url': Var('chromium_url') + '/external/github.com/google/benchmark.git' + '@' + '7f27afe83b82f3a98baf58ef595814b9d42a5b2b',
-    'condition': 'checkout_google_benchmark',
+    'url': Var('chromium_url') + '/external/github.com/google/benchmark.git' + '@' + '7d0d9061d83b663ce05d9de5da3d5865a3845b79',
   },
   'third_party/jinja2':
     Var('chromium_url') + '/chromium/src/third_party/jinja2.git' + '@' + '11b6b3e5971d760bd2d310f77643f55a818a6d25',
@@ -212,7 +208,7 @@ deps = {
   'test/mozilla/data':
     Var('chromium_url') + '/v8/deps/third_party/mozilla-tests.git' + '@' + 'f6c578a10ea707b1a8ab0b88943fe5115ce2b9be',
   'test/test262/data':
-    Var('chromium_url') + '/external/github.com/tc39/test262.git' + '@' + '31126581e7290f9233c29cefd93f66c6ac78f1c9',
+    Var('chromium_url') + '/external/github.com/tc39/test262.git' + '@' + '6d353a4436747e2de8820efac27ae5ef7e601b60',
   'test/test262/harness':
     Var('chromium_url') + '/external/github.com/test262-utils/test262-harness-py.git' + '@' + '278bcfaed0dcaa13936831fb1769d15e7c1e3b2b',
   'third_party/qemu-linux-x64': {
@@ -239,7 +235,7 @@ deps = {
       'packages': [
           {
               'package': 'fuchsia/third_party/aemu/linux-amd64',
-              'version': 'SeLS6a0f6IL-PCOUKbMTN5LYgjjJbDSnb3DGf5q9pwsC'
+              'version': '-Sz2gSN_5yVSHDlitjxUlmZpHuz-F2kFDW6TnmggCZoC'
           },
       ],
       'condition': 'host_os == "linux" and checkout_fuchsia',
@@ -256,7 +252,7 @@ deps = {
       'dep_type': 'cipd',
   },
   'tools/clang':
-    Var('chromium_url') + '/chromium/src/tools/clang.git' + '@' + 'a387faa2a6741f565e45d78804a49a0e55de5909',
+    Var('chromium_url') + '/chromium/src/tools/clang.git' + '@' + 'a38f01b956e091d5e698d2af484c81cd4e9a2a2d',
   'tools/luci-go': {
       'packages': [
         {
@@ -290,7 +286,7 @@ deps = {
   'third_party/protobuf':
     Var('chromium_url') + '/external/github.com/google/protobuf'+ '@' + '6a59a2ad1f61d9696092f79b6d74368b4d7970a3',
   'third_party/zlib':
-    Var('chromium_url') + '/chromium/src/third_party/zlib.git'+ '@' + '09490503d0f201b81e03f5ca0ab8ba8ee76d4a8e',
+    Var('chromium_url') + '/chromium/src/third_party/zlib.git'+ '@' + '5b8d433953beb2a75a755ba321a3076b95f7cdb9',
   'third_party/jsoncpp/source':
     Var('chromium_url') + '/external/github.com/open-source-parsers/jsoncpp.git'+ '@' + '9059f5cad030ba11d37818847443a53918c327b1',
   'third_party/ittapi': {
diff --git a/chromium/v8/OWNERS b/chromium/v8/OWNERS
index 2a478dbdc5c..2ad1949b515 100644
--- a/chromium/v8/OWNERS
+++ b/chromium/v8/OWNERS
@@ -21,7 +21,7 @@ per-file PRESUBMIT.py=file:INFRA_OWNERS
 per-file codereview.settings=file:INFRA_OWNERS
 
 per-file AUTHORS=file:COMMON_OWNERS
-per-file WATCHLIST=file:COMMON_OWNERS
+per-file WATCHLISTS=file:COMMON_OWNERS
 
 per-file *-mips*=file:MIPS_OWNERS
 per-file *-mips64*=file:MIPS_OWNERS
diff --git a/chromium/v8/PRESUBMIT.py b/chromium/v8/PRESUBMIT.py
index 2ee14d545ee..61963c62f62 100644
--- a/chromium/v8/PRESUBMIT.py
+++ b/chromium/v8/PRESUBMIT.py
@@ -279,7 +279,7 @@ def _CheckHeadersHaveIncludeGuards(input_api, output_api):
     for line in f.NewContents():
       for i in range(len(guard_patterns)):
         if guard_patterns[i].match(line):
-            found_patterns[i] = True
+          found_patterns[i] = True
       if skip_check_pattern.match(line):
         file_omitted = True
         break
@@ -485,7 +485,9 @@ def _CheckNoexceptAnnotations(input_api, output_api):
         files_to_check=(r'src[\\\/].*', r'test[\\\/].*'),
         # Skip api.cc since we cannot easily add the 'noexcept' annotation to
         # public methods.
-        files_to_skip=(r'src[\\\/]api[\\\/]api\.cc',))
+        # Skip src/bigint/ because it's meant to be V8-independent.
+        files_to_skip=(r'src[\\\/]api[\\\/]api\.cc',
+                       r'src[\\\/]bigint[\\\/].*'))
 
   # matches any class name.
   class_name = r'\b([A-Z][A-Za-z0-9_:]*)(?:::\1)?'
diff --git a/chromium/v8/RISCV_OWNERS b/chromium/v8/RISCV_OWNERS
index f3240b500b1..8f8e15a40a0 100644
--- a/chromium/v8/RISCV_OWNERS
+++ b/chromium/v8/RISCV_OWNERS
@@ -1,3 +1,3 @@
 brice.dobry@futurewei.com
-lazyparser@gmail.com
 peng.w@rioslab.org
+qiuji@iscas.ac.cn
diff --git a/chromium/v8/WATCHLISTS b/chromium/v8/WATCHLISTS
index fa95f144cb7..c54f15ad797 100644
--- a/chromium/v8/WATCHLISTS
+++ b/chromium/v8/WATCHLISTS
@@ -51,6 +51,9 @@
                   '|test/cctest/interpreter/' \
                   '|test/unittests/interpreter/',
     },
+    'baseline': {
+      'filepath': 'src/baseline/'
+    },
     'feature_shipping_status': {
       'filepath': 'src/flags/flag-definitions.h',
     },
@@ -91,6 +94,9 @@
       'filepath': 'src/base/ieee754\.(cc|h)' \
                   '|src/base/overflowing-math.h' \
                   '|LICENSE.fdlibm',
+    },
+    'regexp': {
+      'filepath': 'src/.*regexp',
     }
   },
 
@@ -110,6 +116,10 @@
     'interpreter': [
       'rmcilroy@chromium.org',
     ],
+    'baseline': [
+      'leszeks+watch@chromium.org',
+      'verwaest+watch@chromium.org',
+    ],
     'feature_shipping_status': [
       'hablich@chromium.org',
     ],
@@ -142,5 +152,9 @@
       'rtoy+watch@chromium.org',
       'hongchan+watch@chromium.org'
     ],
+    'regexp': [
+      'jgruber+watch@chromium.org',
+      'pthier+watch@chromium.org'
+    ],
   },
 }
diff --git a/chromium/v8/gni/v8.gni b/chromium/v8/gni/v8.gni
index 9325baf996e..8741e86c087 100644
--- a/chromium/v8/gni/v8.gni
+++ b/chromium/v8/gni/v8.gni
@@ -75,13 +75,16 @@ declare_args() {
   # executed as standard JavaScript instead.
   v8_enable_webassembly = ""
 
+  # Enable runtime call stats.
+  v8_enable_runtime_call_stats = true
+
   # Add fuzzilli fuzzer support.
   v8_fuzzilli = false
 
   # Scan the call stack conservatively during garbage collection.
   v8_enable_conservative_stack_scanning = false
 
-  v8_enable_google_benchmark = checkout_google_benchmark
+  v8_enable_google_benchmark = false
 
   cppgc_is_standalone = false
 }
diff --git a/chromium/v8/include/cppgc/allocation.h b/chromium/v8/include/cppgc/allocation.h
index f4f0e72bd51..7a803cf2cc4 100644
--- a/chromium/v8/include/cppgc/allocation.h
+++ b/chromium/v8/include/cppgc/allocation.h
@@ -8,6 +8,7 @@
 #include <stdint.h>
 
 #include <atomic>
+#include <type_traits>
 
 #include "cppgc/custom-space.h"
 #include "cppgc/garbage-collected.h"
@@ -103,6 +104,10 @@ class MakeGarbageCollectedTraitBase
    * \returns the memory to construct an object of type T on.
    */
   V8_INLINE static void* Allocate(AllocationHandle& handle, size_t size) {
+    static_assert(
+        std::is_base_of<typename T::ParentMostGarbageCollectedType, T>::value,
+        "U of GarbageCollected<U> must be a base of T. Check "
+        "GarbageCollected<T> base class inheritance.");
     return SpacePolicy<
         typename internal::GCInfoFolding<
             T, typename T::ParentMostGarbageCollectedType>::ResultType,
diff --git a/chromium/v8/include/cppgc/cross-thread-persistent.h b/chromium/v8/include/cppgc/cross-thread-persistent.h
index 9cfcd23fdf8..fe61e9acbc3 100644
--- a/chromium/v8/include/cppgc/cross-thread-persistent.h
+++ b/chromium/v8/include/cppgc/cross-thread-persistent.h
@@ -28,19 +28,19 @@ class BasicCrossThreadPersistent final : public PersistentBase,
 
   ~BasicCrossThreadPersistent() { Clear(); }
 
-  BasicCrossThreadPersistent(  // NOLINT
+  BasicCrossThreadPersistent(
       const SourceLocation& loc = SourceLocation::Current())
       : LocationPolicy(loc) {}
 
-  BasicCrossThreadPersistent(  // NOLINT
+  BasicCrossThreadPersistent(
       std::nullptr_t, const SourceLocation& loc = SourceLocation::Current())
       : LocationPolicy(loc) {}
 
-  BasicCrossThreadPersistent(  // NOLINT
+  BasicCrossThreadPersistent(
       SentinelPointer s, const SourceLocation& loc = SourceLocation::Current())
       : PersistentBase(s), LocationPolicy(loc) {}
 
-  BasicCrossThreadPersistent(  // NOLINT
+  BasicCrossThreadPersistent(
       T* raw, const SourceLocation& loc = SourceLocation::Current())
       : PersistentBase(raw), LocationPolicy(loc) {
     if (!IsValid(raw)) return;
@@ -58,7 +58,7 @@ class BasicCrossThreadPersistent final : public PersistentBase,
     friend class BasicCrossThreadPersistent;
   };
 
-  BasicCrossThreadPersistent(  // NOLINT
+  BasicCrossThreadPersistent(
       UnsafeCtorTag, T* raw,
       const SourceLocation& loc = SourceLocation::Current())
       : PersistentBase(raw), LocationPolicy(loc) {
@@ -68,14 +68,14 @@ class BasicCrossThreadPersistent final : public PersistentBase,
     this->CheckPointer(raw);
   }
 
-  BasicCrossThreadPersistent(  // NOLINT
+  BasicCrossThreadPersistent(
       T& raw, const SourceLocation& loc = SourceLocation::Current())
       : BasicCrossThreadPersistent(&raw, loc) {}
 
   template <typename U, typename MemberBarrierPolicy,
             typename MemberWeaknessTag, typename MemberCheckingPolicy,
             typename = std::enable_if_t<std::is_base_of<T, U>::value>>
-  BasicCrossThreadPersistent(  // NOLINT
+  BasicCrossThreadPersistent(
       internal::BasicMember<U, MemberBarrierPolicy, MemberWeaknessTag,
                             MemberCheckingPolicy>
           member,
@@ -94,7 +94,7 @@ class BasicCrossThreadPersistent final : public PersistentBase,
   template <typename U, typename OtherWeaknessPolicy,
             typename OtherLocationPolicy, typename OtherCheckingPolicy,
             typename = std::enable_if_t<std::is_base_of<T, U>::value>>
-  BasicCrossThreadPersistent(  // NOLINT
+  BasicCrossThreadPersistent(
       const BasicCrossThreadPersistent<U, OtherWeaknessPolicy,
                                        OtherLocationPolicy,
                                        OtherCheckingPolicy>& other,
@@ -139,7 +139,7 @@ class BasicCrossThreadPersistent final : public PersistentBase,
     GetNode()->UpdateOwner(this);
     other.SetValue(nullptr);
     other.SetNode(nullptr);
-    this->CheckPointer(GetValue());
+    this->CheckPointer(Get());
     return *this;
   }
 
@@ -236,7 +236,7 @@ class BasicCrossThreadPersistent final : public PersistentBase,
    *
    * \returns the object.
    */
-  operator T*() const { return Get(); }  // NOLINT
+  operator T*() const { return Get(); }
 
   /**
    * Dereferences the stored object.
diff --git a/chromium/v8/include/cppgc/explicit-management.h b/chromium/v8/include/cppgc/explicit-management.h
index 8fb321c08ca..cdb6af48586 100644
--- a/chromium/v8/include/cppgc/explicit-management.h
+++ b/chromium/v8/include/cppgc/explicit-management.h
@@ -12,9 +12,12 @@
 #include "cppgc/type-traits.h"
 
 namespace cppgc {
+
+class HeapHandle;
+
 namespace internal {
 
-V8_EXPORT void FreeUnreferencedObject(void*);
+V8_EXPORT void FreeUnreferencedObject(HeapHandle&, void*);
 V8_EXPORT bool Resize(void*, size_t);
 
 }  // namespace internal
@@ -30,15 +33,19 @@ namespace subtle {
  * to `object` after calling `FreeUnreferencedObject()`. In case such a
  * reference exists, it's use results in a use-after-free.
  *
+ * To aid in using the API, `FreeUnreferencedObject()` may be called from
+ * destructors on objects that would be reclaimed in the same garbage collection
+ * cycle.
+ *
+ * \param heap_handle The corresponding heap.
  * \param object Reference to an object that is of type `GarbageCollected` and
  *   should be immediately reclaimed.
  */
 template <typename T>
-void FreeUnreferencedObject(T* object) {
+void FreeUnreferencedObject(HeapHandle& heap_handle, T& object) {
   static_assert(IsGarbageCollectedTypeV<T>,
                 "Object must be of type GarbageCollected.");
-  if (!object) return;
-  internal::FreeUnreferencedObject(object);
+  internal::FreeUnreferencedObject(heap_handle, &object);
 }
 
 /**
@@ -53,6 +60,8 @@ void FreeUnreferencedObject(T* object) {
  * object down, the reclaimed area is not used anymore. Any subsequent use
  * results in a use-after-free.
  *
+ * The `object` must be live when calling `Resize()`.
+ *
  * \param object Reference to an object that is of type `GarbageCollected` and
  *   should be resized.
  * \param additional_bytes Bytes in addition to sizeof(T) that the object should
diff --git a/chromium/v8/include/cppgc/heap-statistics.h b/chromium/v8/include/cppgc/heap-statistics.h
index cf8d6633cc2..2fe6e1ae58a 100644
--- a/chromium/v8/include/cppgc/heap-statistics.h
+++ b/chromium/v8/include/cppgc/heap-statistics.h
@@ -57,7 +57,7 @@ struct HeapStatistics final {
   };
 
   /**
-   * Stastistics of the freelist (used only in non-large object spaces). For
+   * Statistics of the freelist (used only in non-large object spaces). For
    * each bucket in the freelist the statistics record the bucket size, the
    * number of freelist entries in the bucket, and the overall allocated memory
    * consumed by these freelist entries.
@@ -67,7 +67,7 @@ struct HeapStatistics final {
     std::vector<size_t> bucket_size;
     /** number of freelist entries per bucket. */
     std::vector<size_t> free_count;
-    /** memory size concumed by freelist entries per size. */
+    /** memory size consumed by freelist entries per size. */
     std::vector<size_t> free_size;
   };
 
diff --git a/chromium/v8/include/cppgc/internal/compiler-specific.h b/chromium/v8/include/cppgc/internal/compiler-specific.h
index c580894b35d..595b6398cb7 100644
--- a/chromium/v8/include/cppgc/internal/compiler-specific.h
+++ b/chromium/v8/include/cppgc/internal/compiler-specific.h
@@ -21,13 +21,13 @@ namespace cppgc {
 
 // [[no_unique_address]] comes in C++20 but supported in clang with -std >=
 // c++11.
-#if CPPGC_HAS_CPP_ATTRIBUTE(no_unique_address)  // NOLINTNEXTLINE
+#if CPPGC_HAS_CPP_ATTRIBUTE(no_unique_address)
 #define CPPGC_NO_UNIQUE_ADDRESS [[no_unique_address]]
 #else
 #define CPPGC_NO_UNIQUE_ADDRESS
 #endif
 
-#if CPPGC_HAS_ATTRIBUTE(unused)  // NOLINTNEXTLINE
+#if CPPGC_HAS_ATTRIBUTE(unused)
 #define CPPGC_UNUSED __attribute__((unused))
 #else
 #define CPPGC_UNUSED
diff --git a/chromium/v8/include/cppgc/internal/pointer-policies.h b/chromium/v8/include/cppgc/internal/pointer-policies.h
index ceb002f02d5..e09b86199f4 100644
--- a/chromium/v8/include/cppgc/internal/pointer-policies.h
+++ b/chromium/v8/include/cppgc/internal/pointer-policies.h
@@ -9,12 +9,15 @@
 #include <type_traits>
 
 #include "cppgc/internal/write-barrier.h"
+#include "cppgc/sentinel-pointer.h"
 #include "cppgc/source-location.h"
+#include "cppgc/type-traits.h"
 #include "v8config.h"  // NOLINT(build/include_directory)
 
 namespace cppgc {
 namespace internal {
 
+class HeapBase;
 class PersistentRegion;
 class CrossThreadPersistentRegion;
 
@@ -50,11 +53,31 @@ struct NoWriteBarrierPolicy {
 
 class V8_EXPORT EnabledCheckingPolicy {
  protected:
-  EnabledCheckingPolicy();
-  void CheckPointer(const void* ptr);
+  template <typename T>
+  void CheckPointer(const T* ptr) {
+    if (!ptr || (kSentinelPointer == ptr)) return;
+
+    CheckPointersImplTrampoline<T>::Call(this, ptr);
+  }
 
  private:
-  void* impl_;
+  void CheckPointerImpl(const void* ptr, bool points_to_payload);
+
+  template <typename T, bool = IsCompleteV<T>>
+  struct CheckPointersImplTrampoline {
+    static void Call(EnabledCheckingPolicy* policy, const T* ptr) {
+      policy->CheckPointerImpl(ptr, false);
+    }
+  };
+
+  template <typename T>
+  struct CheckPointersImplTrampoline<T, true> {
+    static void Call(EnabledCheckingPolicy* policy, const T* ptr) {
+      policy->CheckPointerImpl(ptr, IsGarbageCollectedTypeV<T>);
+    }
+  };
+
+  const HeapBase* heap_ = nullptr;
 };
 
 class DisabledCheckingPolicy {
@@ -63,9 +86,11 @@ class DisabledCheckingPolicy {
 };
 
 #if V8_ENABLE_CHECKS
-using DefaultCheckingPolicy = EnabledCheckingPolicy;
+using DefaultMemberCheckingPolicy = EnabledCheckingPolicy;
+using DefaultPersistentCheckingPolicy = EnabledCheckingPolicy;
 #else
-using DefaultCheckingPolicy = DisabledCheckingPolicy;
+using DefaultMemberCheckingPolicy = DisabledCheckingPolicy;
+using DefaultPersistentCheckingPolicy = DisabledCheckingPolicy;
 #endif
 
 class KeepLocationPolicy {
@@ -133,10 +158,10 @@ template <typename T, typename WeaknessPolicy,
 class BasicCrossThreadPersistent;
 template <typename T, typename WeaknessPolicy,
           typename LocationPolicy = DefaultLocationPolicy,
-          typename CheckingPolicy = DefaultCheckingPolicy>
+          typename CheckingPolicy = DefaultPersistentCheckingPolicy>
 class BasicPersistent;
 template <typename T, typename WeaknessTag, typename WriteBarrierPolicy,
-          typename CheckingPolicy = DefaultCheckingPolicy>
+          typename CheckingPolicy = DefaultMemberCheckingPolicy>
 class BasicMember;
 
 }  // namespace internal
diff --git a/chromium/v8/include/cppgc/member.h b/chromium/v8/include/cppgc/member.h
index 7b76bc4f755..16aed060226 100644
--- a/chromium/v8/include/cppgc/member.h
+++ b/chromium/v8/include/cppgc/member.h
@@ -24,8 +24,11 @@ namespace internal {
 // BasicMember on casting to the right type as needed.
 class MemberBase {
  protected:
+  struct AtomicInitializerTag {};
+
   MemberBase() = default;
   explicit MemberBase(const void* value) : raw_(value) {}
+  MemberBase(const void* value, AtomicInitializerTag) { SetRawAtomic(value); }
 
   const void** GetRawSlot() const { return &raw_; }
   const void* GetRaw() const { return raw_; }
@@ -61,6 +64,20 @@ class BasicMember final : private MemberBase, private CheckingPolicy {
     this->CheckPointer(Get());
   }
   BasicMember(T& raw) : BasicMember(&raw) {}  // NOLINT
+  // Atomic ctor. Using the AtomicInitializerTag forces BasicMember to
+  // initialize using atomic assignments. This is required for preventing
+  // data races with concurrent marking.
+  using AtomicInitializerTag = MemberBase::AtomicInitializerTag;
+  BasicMember(std::nullptr_t, AtomicInitializerTag atomic)
+      : MemberBase(nullptr, atomic) {}
+  BasicMember(SentinelPointer s, AtomicInitializerTag atomic)
+      : MemberBase(s, atomic) {}
+  BasicMember(T* raw, AtomicInitializerTag atomic) : MemberBase(raw, atomic) {
+    InitializingWriteBarrier();
+    this->CheckPointer(Get());
+  }
+  BasicMember(T& raw, AtomicInitializerTag atomic)
+      : BasicMember(&raw, atomic) {}
   // Copy ctor.
   BasicMember(const BasicMember& other) : BasicMember(other.Get()) {}
   // Allow heterogeneous construction.
@@ -79,9 +96,8 @@ class BasicMember final : private MemberBase, private CheckingPolicy {
   template <typename U, typename OtherBarrierPolicy, typename OtherWeaknessTag,
             typename OtherCheckingPolicy,
             typename = std::enable_if_t<std::is_base_of<T, U>::value>>
-  BasicMember(  // NOLINT
-      BasicMember<U, OtherWeaknessTag, OtherBarrierPolicy,
-                  OtherCheckingPolicy>&& other) noexcept
+  BasicMember(BasicMember<U, OtherWeaknessTag, OtherBarrierPolicy,
+                          OtherCheckingPolicy>&& other) noexcept
       : BasicMember(other.Get()) {
     other.Clear();
   }
@@ -90,10 +106,9 @@ class BasicMember final : private MemberBase, private CheckingPolicy {
             typename PersistentLocationPolicy,
             typename PersistentCheckingPolicy,
             typename = std::enable_if_t<std::is_base_of<T, U>::value>>
-  BasicMember(  // NOLINT
-      const BasicPersistent<U, PersistentWeaknessPolicy,
-                            PersistentLocationPolicy, PersistentCheckingPolicy>&
-          p)
+  BasicMember(const BasicPersistent<U, PersistentWeaknessPolicy,
+                                    PersistentLocationPolicy,
+                                    PersistentCheckingPolicy>& p)
       : BasicMember(p.Get()) {}
 
   // Copy assignment.
@@ -161,7 +176,7 @@ class BasicMember final : private MemberBase, private CheckingPolicy {
   }
 
   explicit operator bool() const { return Get(); }
-  operator T*() const { return Get(); }  // NOLINT
+  operator T*() const { return Get(); }
   T* operator->() const { return Get(); }
   T& operator*() const { return *Get(); }
 
diff --git a/chromium/v8/include/cppgc/persistent.h b/chromium/v8/include/cppgc/persistent.h
index d7aac723c0d..22cda7c6e8f 100644
--- a/chromium/v8/include/cppgc/persistent.h
+++ b/chromium/v8/include/cppgc/persistent.h
@@ -95,7 +95,7 @@ class BasicPersistent final : public PersistentBase,
   template <typename U, typename OtherWeaknessPolicy,
             typename OtherLocationPolicy, typename OtherCheckingPolicy,
             typename = std::enable_if_t<std::is_base_of<T, U>::value>>
-  BasicPersistent(  // NOLINT
+  BasicPersistent(
       const BasicPersistent<U, OtherWeaknessPolicy, OtherLocationPolicy,
                             OtherCheckingPolicy>& other,
       const SourceLocation& loc = SourceLocation::Current())
@@ -118,7 +118,7 @@ class BasicPersistent final : public PersistentBase,
   template <typename U, typename MemberBarrierPolicy,
             typename MemberWeaknessTag, typename MemberCheckingPolicy,
             typename = std::enable_if_t<std::is_base_of<T, U>::value>>
-  BasicPersistent(internal::BasicMember<U, MemberBarrierPolicy,  // NOLINT
+  BasicPersistent(internal::BasicMember<U, MemberBarrierPolicy,
                                         MemberWeaknessTag, MemberCheckingPolicy>
                       member,
                   const SourceLocation& loc = SourceLocation::Current())
@@ -181,7 +181,7 @@ class BasicPersistent final : public PersistentBase,
   }
 
   explicit operator bool() const { return Get(); }
-  operator T*() const { return Get(); }  // NOLINT
+  operator T*() const { return Get(); }
   T* operator->() const { return Get(); }
   T& operator*() const { return *Get(); }
 
diff --git a/chromium/v8/include/cppgc/sentinel-pointer.h b/chromium/v8/include/cppgc/sentinel-pointer.h
index f7915834e5a..b049d1a2b34 100644
--- a/chromium/v8/include/cppgc/sentinel-pointer.h
+++ b/chromium/v8/include/cppgc/sentinel-pointer.h
@@ -14,7 +14,7 @@ namespace internal {
 // sentinel is defined by the embedder.
 struct SentinelPointer {
   template <typename T>
-  operator T*() const {  // NOLINT
+  operator T*() const {
     static constexpr intptr_t kSentinelValue = 1;
     return reinterpret_cast<T*>(kSentinelValue);
   }
diff --git a/chromium/v8/include/cppgc/type-traits.h b/chromium/v8/include/cppgc/type-traits.h
index 2b50a2164b2..56cd55d61e2 100644
--- a/chromium/v8/include/cppgc/type-traits.h
+++ b/chromium/v8/include/cppgc/type-traits.h
@@ -7,6 +7,7 @@
 
 // This file should stay with minimal dependencies to allow embedder to check
 // against Oilpan types without including any other parts.
+#include <cstddef>
 #include <type_traits>
 
 namespace cppgc {
@@ -164,6 +165,18 @@ struct IsUntracedMemberType : std::false_type {};
 template <typename T>
 struct IsUntracedMemberType<T, true> : std::true_type {};
 
+template <typename T>
+struct IsComplete {
+ private:
+  template <typename U, size_t = sizeof(U)>
+  static std::true_type IsSizeOfKnown(U*);
+  static std::false_type IsSizeOfKnown(...);
+
+ public:
+  static constexpr bool value =
+      decltype(IsSizeOfKnown(std::declval<T*>()))::value;
+};
+
 }  // namespace internal
 
 /**
@@ -223,6 +236,12 @@ constexpr bool IsWeakMemberTypeV = internal::IsWeakMemberType<T>::value;
 template <typename T>
 constexpr bool IsWeakV = internal::IsWeak<T>::value;
 
+/**
+ * Value is true for types that are complete, and false otherwise.
+ */
+template <typename T>
+constexpr bool IsCompleteV = internal::IsComplete<T>::value;
+
 }  // namespace cppgc
 
 #endif  // INCLUDE_CPPGC_TYPE_TRAITS_H_
diff --git a/chromium/v8/include/js_protocol.pdl b/chromium/v8/include/js_protocol.pdl
index 666952f27b9..9c0483ae705 100644
--- a/chromium/v8/include/js_protocol.pdl
+++ b/chromium/v8/include/js_protocol.pdl
@@ -267,7 +267,7 @@ domain Debugger
       BreakpointId breakpointId
 
   # Restarts particular call frame from the beginning.
-  command restartFrame
+  deprecated command restartFrame
     parameters
       # Call frame identifier to evaluate on.
       CallFrameId callFrameId
@@ -707,6 +707,8 @@ experimental domain HeapProfiler
       # when the tracking is stopped.
       optional boolean reportProgress
       optional boolean treatGlobalObjectsAsRoots
+      # If true, numerical values are included in the snapshot
+      optional boolean captureNumericValue
 
   command takeHeapSnapshot
     parameters
@@ -714,6 +716,8 @@ experimental domain HeapProfiler
       optional boolean reportProgress
       # If true, a raw snapshot without artifical roots will be generated
       optional boolean treatGlobalObjectsAsRoots
+      # If true, numerical values are included in the snapshot
+      optional boolean captureNumericValue
 
   event addHeapSnapshotChunk
     parameters
@@ -1563,7 +1567,10 @@ domain Runtime
       # execution context. If omitted and `executionContextName` is not set,
       # the binding is exposed to all execution contexts of the target.
       # This parameter is mutually exclusive with `executionContextName`.
-      optional ExecutionContextId executionContextId
+      # Deprecated in favor of `executionContextName` due to an unclear use case
+      # and bugs in implementation (crbug.com/1169639). `executionContextId` will be
+      # removed in the future.
+      deprecated optional ExecutionContextId executionContextId
       # If specified, the binding is exposed to the executionContext with
       # matching name, even for contexts created after the binding is added.
       # See also `ExecutionContext.name` and `worldName` parameter to
diff --git a/chromium/v8/include/v8-cppgc.h b/chromium/v8/include/v8-cppgc.h
index fba35f71c9a..745fb04347e 100644
--- a/chromium/v8/include/v8-cppgc.h
+++ b/chromium/v8/include/v8-cppgc.h
@@ -28,6 +28,8 @@ namespace internal {
 class CppHeap;
 }  // namespace internal
 
+class CustomSpaceStatisticsReceiver;
+
 /**
  * Describes how V8 wrapper objects maintain references to garbage-collected C++
  * objects.
@@ -120,6 +122,16 @@ class V8_EXPORT CppHeap {
       cppgc::HeapStatistics::DetailLevel detail_level);
 
   /**
+   * Collects statistics for the given spaces and reports them to the receiver.
+   *
+   * \param custom_spaces a collection of custom space indicies.
+   * \param receiver an object that gets the results.
+   */
+  void CollectCustomSpaceStatisticsAtLastGC(
+      std::vector<cppgc::CustomSpaceIndex> custom_spaces,
+      std::unique_ptr<CustomSpaceStatisticsReceiver> receiver);
+
+  /**
    * Enables a detached mode that allows testing garbage collection using
    * `cppgc::testing` APIs. Once used, the heap cannot be attached to an
    * `Isolate` anymore.
@@ -277,6 +289,26 @@ class V8_EXPORT JSHeapConsistency final {
                                          const TracedReferenceBase& ref);
 };
 
+/**
+ * Provided as input to `CppHeap::CollectCustomSpaceStatisticsAtLastGC()`.
+ *
+ * Its method is invoked with the results of the statistic collection.
+ */
+class CustomSpaceStatisticsReceiver {
+ public:
+  virtual ~CustomSpaceStatisticsReceiver() = default;
+  /**
+   * Reports the size of a space at the last GC. It is called for each space
+   * that was requested in `CollectCustomSpaceStatisticsAtLastGC()`.
+   *
+   * \param space_index The index of the space.
+   * \param bytes The total size of live objects in the space at the last GC.
+   *    It is zero if there was no GC yet.
+   */
+  virtual void AllocatedBytes(cppgc::CustomSpaceIndex space_index,
+                              size_t bytes) = 0;
+};
+
 }  // namespace v8
 
 namespace cppgc {
diff --git a/chromium/v8/include/v8-fast-api-calls.h b/chromium/v8/include/v8-fast-api-calls.h
index f8b5acb0934..cdf67decf67 100644
--- a/chromium/v8/include/v8-fast-api-calls.h
+++ b/chromium/v8/include/v8-fast-api-calls.h
@@ -70,8 +70,7 @@
  *        return GetInternalField<CustomEmbedderType,
  *                                kV8EmbedderWrapperObjectIndex>(wrapper);
  *      }
- *      static void FastMethod(v8::ApiObject receiver_obj, int param) {
- *        v8::Object* v8_object = reinterpret_cast<v8::Object*>(&api_object);
+ *      static void FastMethod(v8::Local<v8::Object> receiver_obj, int param) {
  *        CustomEmbedderType* receiver = static_cast<CustomEmbedderType*>(
  *          receiver_obj->GetAlignedPointerFromInternalField(
  *            kV8EmbedderWrapperObjectIndex));
@@ -190,10 +189,13 @@
 #include <tuple>
 #include <type_traits>
 
+#include "v8.h"        // NOLINT(build/include_directory)
 #include "v8config.h"  // NOLINT(build/include_directory)
 
 namespace v8 {
 
+class Isolate;
+
 class CTypeInfo {
  public:
   enum class Type : uint8_t {
@@ -206,6 +208,8 @@ class CTypeInfo {
     kFloat32,
     kFloat64,
     kV8Value,
+    kApiObject,  // This will be deprecated once all users have
+                 // migrated from v8::ApiObject to v8::Local<v8::Value>.
   };
 
   // kCallbackOptionsType is not part of the Type enum
@@ -310,7 +314,7 @@ class V8_EXPORT CFunction {
   };
 };
 
-struct ApiObject {
+struct V8_DEPRECATE_SOON("Use v8::Local<v8::Value> instead.") ApiObject {
   uintptr_t address;
 };
 
@@ -322,6 +326,14 @@ struct ApiObject {
  */
 struct FastApiCallbackOptions {
   /**
+   * Creates a new instance of FastApiCallbackOptions for testing purpose.  The
+   * returned instance may be filled with mock data.
+   */
+  static FastApiCallbackOptions CreateForTesting(Isolate* isolate) {
+    return {false, {0}};
+  }
+
+  /**
    * If the callback wants to signal an error condition or to perform an
    * allocation, it must set options.fallback to true and do an early return
    * from the fast method. Then V8 checks the value of options.fallback and if
@@ -336,8 +348,12 @@ struct FastApiCallbackOptions {
 
   /**
    * The `data` passed to the FunctionTemplate constructor, or `undefined`.
+   * `data_ptr` allows for default constructing FastApiCallbackOptions.
    */
-  const ApiObject data;
+  union {
+    uintptr_t data_ptr;
+    v8::Value data;
+  };
 };
 
 namespace internal {
@@ -398,16 +414,22 @@ struct TypeInfoHelper {
     static constexpr CTypeInfo::Type Type() { return CTypeInfo::Type::Enum; } \
   };
 
-#define BASIC_C_TYPES(V) \
-  V(void, kVoid)         \
-  V(bool, kBool)         \
-  V(int32_t, kInt32)     \
-  V(uint32_t, kUint32)   \
-  V(int64_t, kInt64)     \
-  V(uint64_t, kUint64)   \
-  V(float, kFloat32)     \
-  V(double, kFloat64)    \
-  V(ApiObject, kV8Value)
+#define BASIC_C_TYPES(V)            \
+  V(void, kVoid)                    \
+  V(bool, kBool)                    \
+  V(int32_t, kInt32)                \
+  V(uint32_t, kUint32)              \
+  V(int64_t, kInt64)                \
+  V(uint64_t, kUint64)              \
+  V(float, kFloat32)                \
+  V(double, kFloat64)               \
+  V(ApiObject, kApiObject)          \
+  V(v8::Local<v8::Value>, kV8Value) \
+  V(v8::Local<v8::Object>, kV8Value)
+
+// ApiObject was a temporary solution to wrap the pointer to the v8::Value.
+// Please use v8::Local<v8::Value> in new code for the arguments and
+// v8::Local<v8::Object> for the receiver, as ApiObject will be deprecated.
 
 BASIC_C_TYPES(SPECIALIZE_GET_TYPE_INFO_HELPER_FOR)
 
diff --git a/chromium/v8/include/v8-inspector.h b/chromium/v8/include/v8-inspector.h
index a55518e4593..852b39d7252 100644
--- a/chromium/v8/include/v8-inspector.h
+++ b/chromium/v8/include/v8-inspector.h
@@ -105,8 +105,9 @@ class V8_EXPORT V8StackTrace {
   virtual StringView topSourceURL() const = 0;
   virtual int topLineNumber() const = 0;
   virtual int topColumnNumber() const = 0;
-  virtual StringView topScriptId() const = 0;
-  virtual int topScriptIdAsInteger() const = 0;
+  virtual int topScriptId() const = 0;
+  V8_DEPRECATE_SOON("Use V8::StackTrace::topScriptId() instead.")
+  int topScriptIdAsInteger() const { return topScriptId(); }
   virtual StringView topFunctionName() const = 0;
 
   virtual ~V8StackTrace() = default;
@@ -130,6 +131,10 @@ class V8_EXPORT V8InspectorSession {
     virtual v8::Local<v8::Value> get(v8::Local<v8::Context>) = 0;
     virtual ~Inspectable() = default;
   };
+  class V8_EXPORT CommandLineAPIScope {
+   public:
+    virtual ~CommandLineAPIScope() = default;
+  };
   virtual void addInspectedObject(std::unique_ptr<Inspectable>) = 0;
 
   // Dispatching protocol messages.
@@ -139,6 +144,9 @@ class V8_EXPORT V8InspectorSession {
   virtual std::vector<std::unique_ptr<protocol::Schema::API::Domain>>
   supportedDomains() = 0;
 
+  virtual std::unique_ptr<V8InspectorSession::CommandLineAPIScope>
+  initializeCommandLineAPIScope(int executionContextId) = 0;
+
   // Debugger actions.
   virtual void schedulePauseOnNextStatement(StringView breakReason,
                                             StringView breakDetails) = 0;
diff --git a/chromium/v8/include/v8-internal.h b/chromium/v8/include/v8-internal.h
index eb18f76504d..f289149d8d0 100644
--- a/chromium/v8/include/v8-internal.h
+++ b/chromium/v8/include/v8-internal.h
@@ -33,6 +33,7 @@ const int kApiSystemPointerSize = sizeof(void*);
 const int kApiDoubleSize = sizeof(double);
 const int kApiInt32Size = sizeof(int32_t);
 const int kApiInt64Size = sizeof(int64_t);
+const int kApiSizetSize = sizeof(size_t);
 
 // Tag information for HeapObject.
 const int kHeapObjectTag = 1;
@@ -40,6 +41,13 @@ const int kWeakHeapObjectTag = 3;
 const int kHeapObjectTagSize = 2;
 const intptr_t kHeapObjectTagMask = (1 << kHeapObjectTagSize) - 1;
 
+// Tag information for fowarding pointers stored in object headers.
+// 0b00 at the lowest 2 bits in the header indicates that the map word is a
+// forwarding pointer.
+const int kForwardingTag = 0;
+const int kForwardingTagSize = 2;
+const intptr_t kForwardingTagMask = (1 << kForwardingTagSize) - 1;
+
 // Tag information for Smi.
 const int kSmiTag = 0;
 const int kSmiTagSize = 1;
@@ -120,23 +128,28 @@ constexpr bool HeapSandboxIsEnabled() {
 
 using ExternalPointer_t = Address;
 
-// If the heap sandbox is enabled, these tag values will be XORed with the
+// If the heap sandbox is enabled, these tag values will be ORed with the
 // external pointers in the external pointer table to prevent use of pointers of
-// the wrong type.
-enum ExternalPointerTag : Address {
-  kExternalPointerNullTag = static_cast<Address>(0ULL),
-  kArrayBufferBackingStoreTag = static_cast<Address>(1ULL << 48),
-  kTypedArrayExternalPointerTag = static_cast<Address>(2ULL << 48),
-  kDataViewDataPointerTag = static_cast<Address>(3ULL << 48),
-  kExternalStringResourceTag = static_cast<Address>(4ULL << 48),
-  kExternalStringResourceDataTag = static_cast<Address>(5ULL << 48),
-  kForeignForeignAddressTag = static_cast<Address>(6ULL << 48),
-  kNativeContextMicrotaskQueueTag = static_cast<Address>(7ULL << 48),
-  // TODO(v8:10391, saelo): Currently has to be zero so that raw zero values are
-  // also nullptr
-  kEmbedderDataSlotPayloadTag = static_cast<Address>(0ULL << 48),
+// the wrong type. When a pointer is loaded, it is ANDed with the inverse of the
+// expected type's tag. The tags are constructed in a way that guarantees that a
+// failed type check will result in one or more of the top bits of the pointer
+// to be set, rendering the pointer inacessible. This construction allows
+// performing the type check and removing GC marking bits from the pointer at
+// the same time.
+enum ExternalPointerTag : uint64_t {
+  kExternalPointerNullTag = 0x0000000000000000,
+  kArrayBufferBackingStoreTag = 0x00ff000000000000,      // 0b000000011111111
+  kTypedArrayExternalPointerTag = 0x017f000000000000,    // 0b000000101111111
+  kDataViewDataPointerTag = 0x01bf000000000000,          // 0b000000110111111
+  kExternalStringResourceTag = 0x01df000000000000,       // 0b000000111011111
+  kExternalStringResourceDataTag = 0x01ef000000000000,   // 0b000000111101111
+  kForeignForeignAddressTag = 0x01f7000000000000,        // 0b000000111110111
+  kNativeContextMicrotaskQueueTag = 0x01fb000000000000,  // 0b000000111111011
+  kEmbedderDataSlotPayloadTag = 0x01fd000000000000,      // 0b000000111111101
 };
 
+constexpr uint64_t kExternalPointerTagMask = 0xffff000000000000;
+
 #ifdef V8_31BIT_SMIS_ON_64BIT_ARCH
 using PlatformSmiTagging = SmiTagging<kApiInt32Size>;
 #else
@@ -177,6 +190,14 @@ V8_EXPORT bool ShouldThrowOnError(v8::internal::Isolate* isolate);
  * depend on functions and constants defined here.
  */
 class Internals {
+#ifdef V8_MAP_PACKING
+  V8_INLINE static constexpr internal::Address UnpackMapWord(
+      internal::Address mapword) {
+    // TODO(wenyuzhao): Clear header metadata.
+    return mapword ^ kMapWordXorMask;
+  }
+#endif
+
  public:
   // These values match non-compiler-dependent values defined within
   // the implementation of v8.
@@ -209,8 +230,12 @@ class Internals {
       kIsolateFastCCallCallerFpOffset + kApiSystemPointerSize;
   static const int kIsolateFastApiCallTargetOffset =
       kIsolateFastCCallCallerPcOffset + kApiSystemPointerSize;
-  static const int kIsolateStackGuardOffset =
+  static const int kIsolateCageBaseOffset =
       kIsolateFastApiCallTargetOffset + kApiSystemPointerSize;
+  static const int kIsolateLongTaskStatsCounterOffset =
+      kIsolateCageBaseOffset + kApiSystemPointerSize;
+  static const int kIsolateStackGuardOffset =
+      kIsolateLongTaskStatsCounterOffset + kApiSizetSize;
   static const int kIsolateRootsOffset =
       kIsolateStackGuardOffset + 7 * kApiSystemPointerSize;
 
@@ -253,6 +278,17 @@ class Internals {
   // incremental GC once the external memory reaches this limit.
   static constexpr int kExternalAllocationSoftLimit = 64 * 1024 * 1024;
 
+#ifdef V8_MAP_PACKING
+  static const uintptr_t kMapWordMetadataMask = 0xffffULL << 48;
+  // The lowest two bits of mapwords are always `0b10`
+  static const uintptr_t kMapWordSignature = 0b10;
+  // XORing a (non-compressed) map with this mask ensures that the two
+  // low-order bits are 0b10. The 0 at the end makes this look like a Smi,
+  // although real Smis have all lower 32 bits unset. We only rely on these
+  // values passing as Smis in very few places.
+  static const int kMapWordXorMask = 0b11;
+#endif
+
   V8_EXPORT static void CheckInitializedImpl(v8::Isolate* isolate);
   V8_INLINE static void CheckInitialized(v8::Isolate* isolate) {
 #ifdef V8_ENABLE_CHECKS
@@ -279,6 +315,9 @@ class Internals {
   V8_INLINE static int GetInstanceType(const internal::Address obj) {
     typedef internal::Address A;
     A map = ReadTaggedPointerField(obj, kHeapObjectMapOffset);
+#ifdef V8_MAP_PACKING
+    map = UnpackMapWord(map);
+#endif
     return ReadRawField<uint16_t>(map, kMapInstanceTypeOffset);
   }
 
@@ -329,6 +368,12 @@ class Internals {
     return *reinterpret_cast<void* const*>(addr);
   }
 
+  V8_INLINE static void IncrementLongTasksStatsCounter(v8::Isolate* isolate) {
+    internal::Address addr = reinterpret_cast<internal::Address>(isolate) +
+                             kIsolateLongTaskStatsCounterOffset;
+    ++(*reinterpret_cast<size_t*>(addr));
+  }
+
   V8_INLINE static internal::Address* GetRoot(v8::Isolate* isolate, int index) {
     internal::Address addr = reinterpret_cast<internal::Address>(isolate) +
                              kIsolateRootsOffset +
diff --git a/chromium/v8/include/v8-metrics.h b/chromium/v8/include/v8-metrics.h
index 0217f40d63a..2404cc0a4c3 100644
--- a/chromium/v8/include/v8-metrics.h
+++ b/chromium/v8/include/v8-metrics.h
@@ -5,7 +5,8 @@
 #ifndef V8_METRICS_H_
 #define V8_METRICS_H_
 
-#include "v8.h"  // NOLINT(build/include_directory)
+#include "v8-internal.h"  // NOLINT(build/include_directory)
+#include "v8.h"           // NOLINT(build/include_directory)
 
 namespace v8 {
 namespace metrics {
@@ -183,6 +184,32 @@ class V8_EXPORT Recorder {
   static ContextId GetContextId(Local<Context> context);
 };
 
+/**
+ * Experimental API intended for the LongTasks UKM (crbug.com/1173527).
+ * The Reset() method should be called at the start of a potential
+ * long task. The Get() method returns durations of V8 work that
+ * happened during the task.
+ *
+ * This API is experimental and may be removed/changed in the future.
+ */
+struct V8_EXPORT LongTaskStats {
+  /**
+   * Resets durations of V8 work for the new task.
+   */
+  V8_INLINE static void Reset(Isolate* isolate) {
+    v8::internal::Internals::IncrementLongTasksStatsCounter(isolate);
+  }
+
+  /**
+   * Returns durations of V8 work that happened since the last Reset().
+   */
+  static LongTaskStats Get(Isolate* isolate);
+
+  int64_t gc_full_atomic_wall_clock_duration_us = 0;
+  int64_t gc_full_incremental_wall_clock_duration_us = 0;
+  int64_t gc_young_wall_clock_duration_us = 0;
+};
+
 }  // namespace metrics
 }  // namespace v8
 
diff --git a/chromium/v8/include/v8-profiler.h b/chromium/v8/include/v8-profiler.h
index 85d3f8a4821..9a40cfcf307 100644
--- a/chromium/v8/include/v8-profiler.h
+++ b/chromium/v8/include/v8-profiler.h
@@ -289,8 +289,8 @@ class V8_EXPORT CpuProfilingOptions {
    *                             interval, set via SetSamplingInterval(). If
    *                             zero, the sampling interval will be equal to
    *                             the profiler's sampling interval.
-   * \param filter_context Deprecated option to filter by context, currently a
-   *                       no-op.
+   * \param filter_context If specified, profiles will only contain frames
+   *                       using this context. Other frames will be elided.
    */
   CpuProfilingOptions(
       CpuProfilingMode mode = kLeafNodeLineNumbers,
@@ -304,9 +304,13 @@ class V8_EXPORT CpuProfilingOptions {
  private:
   friend class internal::CpuProfile;
 
+  bool has_filter_context() const { return !filter_context_.IsEmpty(); }
+  void* raw_filter_context() const;
+
   CpuProfilingMode mode_;
   unsigned max_samples_;
   int sampling_interval_us_;
+  CopyablePersistentTraits<Context>::CopyablePersistent filter_context_;
 };
 
 /**
@@ -492,7 +496,7 @@ class V8_EXPORT HeapGraphNode {
 /**
  * An interface for exporting data from V8, using "push" model.
  */
-class V8_EXPORT OutputStream {  // NOLINT
+class V8_EXPORT OutputStream {
  public:
   enum WriteResult {
     kContinue = 0,
@@ -519,7 +523,6 @@ class V8_EXPORT OutputStream {  // NOLINT
   }
 };
 
-
 /**
  * HeapSnapshots record the state of the JS heap at some moment.
  */
@@ -586,7 +589,7 @@ class V8_EXPORT HeapSnapshot {
  * An interface for reporting progress and controlling long-running
  * activities.
  */
-class V8_EXPORT ActivityControl {  // NOLINT
+class V8_EXPORT ActivityControl {
  public:
   enum ControlOption {
     kContinue = 0,
@@ -600,7 +603,6 @@ class V8_EXPORT ActivityControl {  // NOLINT
   virtual ControlOption ReportProgressValue(int done, int total) = 0;
 };
 
-
 /**
  * AllocationProfile is a sampled profile of allocations done by the program.
  * This is structured as a call-graph.
@@ -900,7 +902,8 @@ class V8_EXPORT HeapProfiler {
   const HeapSnapshot* TakeHeapSnapshot(
       ActivityControl* control = nullptr,
       ObjectNameResolver* global_object_name_resolver = nullptr,
-      bool treat_global_objects_as_roots = true);
+      bool treat_global_objects_as_roots = true,
+      bool capture_numeric_value = false);
 
   /**
    * Starts tracking of heap objects population statistics. After calling
diff --git a/chromium/v8/include/v8-util.h b/chromium/v8/include/v8-util.h
index 89ec4f6a789..8e4d66153d1 100644
--- a/chromium/v8/include/v8-util.h
+++ b/chromium/v8/include/v8-util.h
@@ -43,7 +43,7 @@ class StdMapTraits {
 
   static bool Empty(Impl* impl) { return impl->empty(); }
   static size_t Size(Impl* impl) { return impl->size(); }
-  static void Swap(Impl& a, Impl& b) { std::swap(a, b); }  // NOLINT
+  static void Swap(Impl& a, Impl& b) { std::swap(a, b); }
   static Iterator Begin(Impl* impl) { return impl->begin(); }
   static Iterator End(Impl* impl) { return impl->end(); }
   static K Key(Iterator it) { return it->first; }
diff --git a/chromium/v8/include/v8-version.h b/chromium/v8/include/v8-version.h
index 4bdb66b2bf6..4ad744f2a84 100644
--- a/chromium/v8/include/v8-version.h
+++ b/chromium/v8/include/v8-version.h
@@ -9,9 +9,9 @@
 // NOTE these macros are used by some of the tool scripts and the build
 // system so their names cannot be changed without changing the scripts.
 #define V8_MAJOR_VERSION 9
-#define V8_MINOR_VERSION 1
-#define V8_BUILD_NUMBER 269
-#define V8_PATCH_LEVEL 38
+#define V8_MINOR_VERSION 2
+#define V8_BUILD_NUMBER 230
+#define V8_PATCH_LEVEL 30
 
 // Use 1 for candidates and 0 otherwise.
 // (Boolean macro values are not supported by all preprocessors.)
diff --git a/chromium/v8/include/v8.h b/chromium/v8/include/v8.h
index 6b672ca750c..c4720ca6954 100644
--- a/chromium/v8/include/v8.h
+++ b/chromium/v8/include/v8.h
@@ -596,7 +596,7 @@ template <class T> class PersistentBase {
    */
   V8_INLINE uint16_t WrapperClassId() const;
 
-  PersistentBase(const PersistentBase& other) = delete;  // NOLINT
+  PersistentBase(const PersistentBase& other) = delete;
   void operator=(const PersistentBase&) = delete;
 
  private:
@@ -708,7 +708,7 @@ template <class T, class M> class Persistent : public PersistentBase<T> {
     return *this;
   }
   template <class S, class M2>
-  V8_INLINE Persistent& operator=(const Persistent<S, M2>& that) { // NOLINT
+  V8_INLINE Persistent& operator=(const Persistent<S, M2>& that) {
     Copy(that);
     return *this;
   }
@@ -723,7 +723,7 @@ template <class T, class M> class Persistent : public PersistentBase<T> {
 
   // TODO(dcarney): this is pretty useless, fix or remove
   template <class S>
-  V8_INLINE static Persistent<T>& Cast(const Persistent<S>& that) {  // NOLINT
+  V8_INLINE static Persistent<T>& Cast(const Persistent<S>& that) {
 #ifdef V8_ENABLE_CHECKS
     // If we're going to perform the type check then we have to check
     // that the handle isn't empty before doing the checked cast.
@@ -734,7 +734,7 @@ template <class T, class M> class Persistent : public PersistentBase<T> {
 
   // TODO(dcarney): this is pretty useless, fix or remove
   template <class S>
-  V8_INLINE Persistent<S>& As() const {  // NOLINT
+  V8_INLINE Persistent<S>& As() const {
     return Persistent<S>::Cast(*this);
   }
 
@@ -803,7 +803,7 @@ class Global : public PersistentBase<T> {
   /**
    * Pass allows returning uniques from functions, etc.
    */
-  Global Pass() { return static_cast<Global&&>(*this); }  // NOLINT
+  Global Pass() { return static_cast<Global&&>(*this); }
 
   /*
    * For compatibility with Chromium's base::Bind (base::Passed).
@@ -905,8 +905,8 @@ class TracedReferenceBase {
  * The exact semantics are:
  * - Tracing garbage collections use |v8::EmbedderHeapTracer| or cppgc.
  * - Non-tracing garbage collections refer to
- *   |v8::EmbedderHeapTracer::IsRootForNonTracingGC()| whether the handle should
- *   be treated as root or not.
+ *   |v8::EmbedderRootsHandler::IsRoot()| whether the handle should
+ * be treated as root or not.
  *
  * Note that the base class cannot be instantiated itself. Choose from
  * - TracedGlobal
@@ -1674,10 +1674,12 @@ class V8_EXPORT Module : public Data {
   /**
    * Evaluates the module and its dependencies.
    *
-   * If status is kInstantiated, run the module's code. On success, set status
-   * to kEvaluated and return the completion value; on failure, set status to
-   * kErrored and propagate the thrown exception (which is then also available
-   * via |GetException|).
+   * If status is kInstantiated, run the module's code and return a Promise
+   * object. On success, set status to kEvaluated and resolve the Promise with
+   * the completion value; on failure, set status to kErrored and reject the
+   * Promise with the error.
+   *
+   * If IsGraphAsync() is false, the returned Promise is settled.
    */
   V8_WARN_UNUSED_RESULT MaybeLocal<Value> Evaluate(Local<Context> context);
 
@@ -2424,7 +2426,7 @@ struct SampleInfo {
   StateTag vm_state;              // Current VM state.
   void* external_callback_entry;  // External callback address if VM is
                                   // executing an external callback.
-  void* top_context;              // Incumbent native context address.
+  void* context;                  // Incumbent native context address.
 };
 
 struct MemoryRange {
@@ -3276,7 +3278,7 @@ class V8_EXPORT String : public Name {
    */
   bool IsExternalOneByte() const;
 
-  class V8_EXPORT ExternalStringResourceBase {  // NOLINT
+  class V8_EXPORT ExternalStringResourceBase {
    public:
     virtual ~ExternalStringResourceBase() = default;
 
@@ -3626,10 +3628,9 @@ class V8_EXPORT Symbol : public Name {
   /**
    * Returns the description string of the symbol, or undefined if none.
    */
+  V8_DEPRECATE_SOON("Use Symbol::Description(isolate)")
   Local<Value> Description() const;
-
-  V8_DEPRECATED("Use Symbol::Description()")
-  Local<Value> Name() const { return Description(); }
+  Local<Value> Description(Isolate* isolate) const;
 
   /**
    * Create a symbol. If description is not empty, it will be used as the
@@ -3980,8 +3981,7 @@ class V8_EXPORT Object : public Value {
   //
   // Returns true on success.
   V8_WARN_UNUSED_RESULT Maybe<bool> DefineProperty(
-      Local<Context> context, Local<Name> key,
-      PropertyDescriptor& descriptor);  // NOLINT(runtime/references)
+      Local<Context> context, Local<Name> key, PropertyDescriptor& descriptor);
 
   V8_WARN_UNUSED_RESULT MaybeLocal<Value> Get(Local<Context> context,
                                               Local<Value> key);
@@ -4771,17 +4771,6 @@ class V8_EXPORT Function : public Object {
   Local<Value> GetDebugName() const;
 
   /**
-   * User-defined name assigned to the "displayName" property of this function.
-   * Used to facilitate debugging and profiling of JavaScript code.
-   */
-  V8_DEPRECATED(
-      "Use v8::Object::Get() instead to look up \"displayName\". "
-      "V8 and DevTools no longer use \"displayName\" in stack "
-      "traces, but the standard \"name\" property. "
-      "See http://crbug.com/1177685.")
-  Local<Value> GetDisplayName() const;
-
-  /**
    * Returns zero based line number of function body and
    * kLineOffsetNotFound if no information available.
    */
@@ -5358,7 +5347,7 @@ class V8_EXPORT ArrayBuffer : public Object {
    * Note that it is unsafe to call back into V8 from any of the allocator
    * functions.
    */
-  class V8_EXPORT Allocator { // NOLINT
+  class V8_EXPORT Allocator {
    public:
     virtual ~Allocator() = default;
 
@@ -6510,6 +6499,15 @@ class V8_EXPORT FunctionTemplate : public Template {
       SideEffectType side_effect_type = SideEffectType::kHasSideEffect,
       const CFunction* c_function = nullptr);
 
+  /** Creates a function template for multiple overloaded fast API calls.*/
+  static Local<FunctionTemplate> NewWithCFunctionOverloads(
+      Isolate* isolate, FunctionCallback callback = nullptr,
+      Local<Value> data = Local<Value>(),
+      Local<Signature> signature = Local<Signature>(), int length = 0,
+      ConstructorBehavior behavior = ConstructorBehavior::kAllow,
+      SideEffectType side_effect_type = SideEffectType::kHasSideEffect,
+      const MemorySpan<const CFunction>& c_function_overloads = {});
+
   /**
    * Creates a function template backed/cached by a private property.
    */
@@ -6541,7 +6539,7 @@ class V8_EXPORT FunctionTemplate : public Template {
   void SetCallHandler(
       FunctionCallback callback, Local<Value> data = Local<Value>(),
       SideEffectType side_effect_type = SideEffectType::kHasSideEffect,
-      const CFunction* c_function = nullptr);
+      const MemorySpan<const CFunction>& c_function_overloads = {});
 
   /** Set the predefined length property for the FunctionTemplate. */
   void SetLength(int length);
@@ -6602,6 +6600,15 @@ class V8_EXPORT FunctionTemplate : public Template {
    */
   bool HasInstance(Local<Value> object);
 
+  /**
+   * Returns true if the given value is an API object that was constructed by an
+   * instance of this function template (without checking for inheriting
+   * function templates).
+   *
+   * This is an experimental feature and may still change significantly.
+   */
+  bool IsLeafTemplateForApiObject(v8::Local<v8::Value> value) const;
+
   V8_INLINE static FunctionTemplate* Cast(Data* data);
 
  private:
@@ -7035,7 +7042,7 @@ class V8_EXPORT AccessorSignature : public Data {
 /**
  * Ignore
  */
-class V8_EXPORT Extension {  // NOLINT
+class V8_EXPORT Extension {
  public:
   // Note that the strings passed into this constructor must live as long
   // as the Extension itself.
@@ -7137,6 +7144,11 @@ class V8_EXPORT ResourceConstraints {
   /**
    * The amount of virtual memory reserved for generated code. This is relevant
    * for 64-bit architectures that rely on code range for calls in code.
+   *
+   * When V8_COMPRESS_POINTERS_IN_SHARED_CAGE is defined, there is a shared
+   * process-wide code range that is lazily initialized. This value is used to
+   * configure that shared code range when the first Isolate is
+   * created. Subsequent Isolates ignore this value.
    */
   size_t code_range_size_in_bytes() const { return code_range_size_; }
   void set_code_range_size_in_bytes(size_t limit) { code_range_size_ = limit; }
@@ -7587,6 +7599,10 @@ using WasmSimdEnabledCallback = bool (*)(Local<Context> context);
 // --- Callback for checking if WebAssembly exceptions are enabled ---
 using WasmExceptionsEnabledCallback = bool (*)(Local<Context> context);
 
+// --- Callback for checking if the SharedArrayBuffer constructor is enabled ---
+using SharedArrayBufferConstructorEnabledCallback =
+    bool (*)(Local<Context> context);
+
 // --- Garbage Collection Callbacks ---
 
 /**
@@ -7908,17 +7924,16 @@ using UnhandledExceptionCallback =
 /**
  * Interface for iterating through all external resources in the heap.
  */
-class V8_EXPORT ExternalResourceVisitor {  // NOLINT
+class V8_EXPORT ExternalResourceVisitor {
  public:
   virtual ~ExternalResourceVisitor() = default;
   virtual void VisitExternalString(Local<String> string) {}
 };
 
-
 /**
  * Interface for iterating through all the persistent handles in the heap.
  */
-class V8_EXPORT PersistentHandleVisitor {  // NOLINT
+class V8_EXPORT PersistentHandleVisitor {
  public:
   virtual ~PersistentHandleVisitor() = default;
   virtual void VisitPersistentHandle(Persistent<Value>* value,
@@ -7936,6 +7951,45 @@ class V8_EXPORT PersistentHandleVisitor {  // NOLINT
 enum class MemoryPressureLevel { kNone, kModerate, kCritical };
 
 /**
+ * Handler for embedder roots on non-unified heap garbage collections.
+ */
+class V8_EXPORT EmbedderRootsHandler {
+ public:
+  virtual ~EmbedderRootsHandler() = default;
+
+  /**
+   * Returns true if the TracedGlobal handle should be considered as root for
+   * the currently running non-tracing garbage collection and false otherwise.
+   * The default implementation will keep all TracedGlobal references as roots.
+   *
+   * If this returns false, then V8 may decide that the object referred to by
+   * such a handle is reclaimed. In that case:
+   * - No action is required if handles are used with destructors, i.e., by just
+   *   using |TracedGlobal|.
+   * - When run without destructors, i.e., by using |TracedReference|, V8 calls
+   *  |ResetRoot|.
+   *
+   * Note that the |handle| is different from the handle that the embedder holds
+   * for retaining the object. The embedder may use |WrapperClassId()| to
+   * distinguish cases where it wants handles to be treated as roots from not
+   * being treated as roots.
+   */
+  virtual bool IsRoot(const v8::TracedReference<v8::Value>& handle) = 0;
+  virtual bool IsRoot(const v8::TracedGlobal<v8::Value>& handle) = 0;
+
+  /**
+   * Used in combination with |IsRoot|. Called by V8 when an
+   * object that is backed by a handle is reclaimed by a non-tracing garbage
+   * collection. It is up to the embedder to reset the original handle.
+   *
+   * Note that the |handle| is different from the handle that the embedder holds
+   * for retaining the object. It is up to the embedder to find the original
+   * handle via the object or class id.
+   */
+  virtual void ResetRoot(const v8::TracedReference<v8::Value>& handle) = 0;
+};
+
+/**
  * Interface for tracing through the embedder heap. During a V8 garbage
  * collection, V8 collects hidden fields of all potential wrappers, and at the
  * end of its marking phase iterates the collection and asks the embedder to
@@ -7997,6 +8051,9 @@ class V8_EXPORT EmbedderHeapTracer {
   /**
    * Called by the embedder to notify V8 of an empty execution stack.
    */
+  V8_DEPRECATE_SOON(
+      "This call only optimized internal caches which V8 is able to figure out "
+      "on its own now.")
   void NotifyEmptyEmbedderStack();
 
   /**
@@ -8060,34 +8117,14 @@ class V8_EXPORT EmbedderHeapTracer {
   void FinalizeTracing();
 
   /**
-   * Returns true if the TracedGlobal handle should be considered as root for
-   * the currently running non-tracing garbage collection and false otherwise.
-   * The default implementation will keep all TracedGlobal references as roots.
-   *
-   * If this returns false, then V8 may decide that the object referred to by
-   * such a handle is reclaimed. In that case:
-   * - No action is required if handles are used with destructors, i.e., by just
-   * using |TracedGlobal|.
-   * - When run without destructors, i.e., by using
-   * |TracedReference|, V8 calls |ResetHandleInNonTracingGC|.
-   *
-   * Note that the |handle| is different from the handle that the embedder holds
-   * for retaining the object. The embedder may use |WrapperClassId()| to
-   * distinguish cases where it wants handles to be treated as roots from not
-   * being treated as roots.
+   * See documentation on EmbedderRootsHandler.
    */
   virtual bool IsRootForNonTracingGC(
       const v8::TracedReference<v8::Value>& handle);
   virtual bool IsRootForNonTracingGC(const v8::TracedGlobal<v8::Value>& handle);
 
   /**
-   * Used in combination with |IsRootForNonTracingGC|. Called by V8 when an
-   * object that is backed by a handle is reclaimed by a non-tracing garbage
-   * collection. It is up to the embedder to reset the original handle.
-   *
-   * Note that the |handle| is different from the handle that the embedder holds
-   * for retaining the object. It is up to the embedder to find the original
-   * handle via the object or class id.
+   * See documentation on EmbedderRootsHandler.
    */
   virtual void ResetHandleInNonTracingGC(
       const v8::TracedReference<v8::Value>& handle);
@@ -8546,6 +8583,7 @@ class V8_EXPORT Isolate {
     kWasmBulkMemory = 109,  // Unused.
     kWasmMultiValue = 110,
     kWasmExceptionHandling = 111,
+    kInvalidatedMegaDOMProtector = 112,
 
     // If you add new values here, you'll also need to update Chromium's:
     // web_feature.mojom, use_counter_callback.cc, and enums.xml. V8 changes to
@@ -8882,6 +8920,17 @@ class V8_EXPORT Isolate {
   Local<Context> GetIncumbentContext();
 
   /**
+   * Schedules a v8::Exception::Error with the given message.
+   * See ThrowException for more details. Templatized to provide compile-time
+   * errors in case of too long strings (see v8::String::NewFromUtf8Literal).
+   */
+  template <int N>
+  Local<Value> ThrowError(const char (&message)[N]) {
+    return ThrowError(String::NewFromUtf8Literal(this, message));
+  }
+  Local<Value> ThrowError(Local<String> message);
+
+  /**
    * Schedules an exception to be thrown when returning to JavaScript.  When an
    * exception has been scheduled it is illegal to invoke any JavaScript
    * operation; the caller must return immediately and only after the exception
@@ -8926,6 +8975,18 @@ class V8_EXPORT Isolate {
   EmbedderHeapTracer* GetEmbedderHeapTracer();
 
   /**
+   * Sets an embedder roots handle that V8 should consider when performing
+   * non-unified heap garbage collections.
+   *
+   * Using only EmbedderHeapTracer automatically sets up a default handler.
+   * The intended use case is for setting a custom handler after invoking
+   * `AttachCppHeap()`.
+   *
+   * V8 does not take ownership of the handler.
+   */
+  void SetEmbedderRootsHandler(EmbedderRootsHandler* handler);
+
+  /**
    * Attaches a managed C++ heap as an extension to the JavaScript heap. The
    * embedder maintains ownership of the CppHeap. At most one C++ heap can be
    * attached to V8.
@@ -9494,6 +9555,9 @@ class V8_EXPORT Isolate {
 
   void SetWasmExceptionsEnabledCallback(WasmExceptionsEnabledCallback callback);
 
+  void SetSharedArrayBufferConstructorEnabledCallback(
+      SharedArrayBufferConstructorEnabledCallback callback);
+
   /**
    * This function can be called by the embedder to signal V8 that the dynamic
    * enabling of features has finished. V8 can now set up dynamically added
@@ -9868,6 +9932,9 @@ class V8_EXPORT V8 {
    * Notifies V8 that the process is cross-origin-isolated, which enables
    * defining the SharedArrayBuffer function on the global object of Contexts.
    */
+  V8_DEPRECATED(
+      "Use the command line argument --enable-sharedarraybuffer-per-context "
+      "together with SetSharedArrayBufferConstructorEnabledCallback")
   static void SetIsCrossOriginIsolated();
 
  private:
@@ -10581,6 +10648,18 @@ class V8_EXPORT Context : public Data {
   void SetContinuationPreservedEmbedderData(Local<Value> context);
 
   /**
+   * Set or clear hooks to be invoked for promise lifecycle operations.
+   * To clear a hook, set it to an empty v8::Function. Each function will
+   * receive the observed promise as the first argument. If a chaining
+   * operation is used on a promise, the init will additionally receive
+   * the parent promise as the second argument.
+   */
+  void SetPromiseHooks(Local<Function> init_hook,
+                       Local<Function> before_hook,
+                       Local<Function> after_hook,
+                       Local<Function> resolve_hook);
+
+  /**
    * Stack-allocated class which sets the execution context for all
    * operations executed within a local scope.
    */
diff --git a/chromium/v8/include/v8config.h b/chromium/v8/include/v8config.h
index acd34d7a1f2..c1bb691f878 100644
--- a/chromium/v8/include/v8config.h
+++ b/chromium/v8/include/v8config.h
@@ -310,10 +310,6 @@ path. Add it with -I<path> to the command line
 // GCC doc: https://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html
 # define V8_HAS_COMPUTED_GOTO 1
 
-// Whether constexpr has full C++14 semantics, in particular that non-constexpr
-// code is allowed as long as it's not executed for any constexpr instantiation.
-# define V8_HAS_CXX14_CONSTEXPR 1
-
 #elif defined(__GNUC__)
 
 # define V8_CC_GNU 1
@@ -336,7 +332,10 @@ path. Add it with -I<path> to the command line
 # define V8_HAS_ATTRIBUTE_UNUSED 1
 # define V8_HAS_ATTRIBUTE_VISIBILITY 1
 # define V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT (!V8_CC_INTEL)
-# define V8_HAS_CPP_ATTRIBUTE_NODISCARD (V8_HAS_CPP_ATTRIBUTE(nodiscard))
+
+// [[nodiscard]] does not work together with with
+// __attribute__((visibility(""))) on GCC 7.4 which is why there is no define
+// for V8_HAS_CPP_ATTRIBUTE_NODISCARD. See https://crbug.com/v8/11707.
 
 # define V8_HAS_BUILTIN_ASSUME_ALIGNED 1
 # define V8_HAS_BUILTIN_CLZ 1
@@ -348,11 +347,6 @@ path. Add it with -I<path> to the command line
 // GCC doc: https://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html
 #define V8_HAS_COMPUTED_GOTO 1
 
-// Whether constexpr has full C++14 semantics, in particular that non-constexpr
-// code is allowed as long as it's not executed for any constexpr instantiation.
-// GCC only supports this since version 6.
-# define V8_HAS_CXX14_CONSTEXPR (V8_GNUC_PREREQ(6, 0, 0))
-
 #endif
 
 #if defined(_MSC_VER)
diff --git a/chromium/v8/infra/mb/mb_config.pyl b/chromium/v8/infra/mb/mb_config.pyl
index c87192896ce..9c0c933cda7 100644
--- a/chromium/v8/infra/mb/mb_config.pyl
+++ b/chromium/v8/infra/mb/mb_config.pyl
@@ -65,6 +65,7 @@
       'V8 Linux64 - debug builder': 'debug_x64',
       'V8 Linux64 - dict tracking - debug - builder': 'debug_x64_dict_tracking_trybot',
       'V8 Linux64 - custom snapshot - debug builder': 'debug_x64_custom',
+      'V8 Linux64 - heap sandbox - debug - builder': 'debug_x64_heap_sandbox',
       'V8 Linux64 - internal snapshot': 'release_x64_internal',
       'V8 Linux64 - debug - header includes': 'debug_x64_header_includes',
       'V8 Linux64 - shared': 'release_x64_shared_verify_heap',
@@ -101,6 +102,7 @@
       # FYI.
       'V8 iOS - sim': 'release_x64_ios_simulator',
       'V8 Linux64 - debug - perfetto - builder': 'debug_x64_perfetto',
+      'V8 Linux64 - debug - single generation - builder': 'debug_x64_single_generation',
       'V8 Linux64 - pointer compression': 'release_x64_pointer_compression',
       'V8 Linux64 - pointer compression without dchecks':
           'release_x64_pointer_compression_without_dchecks',
@@ -136,9 +138,13 @@
       'V8 Clusterfuzz Linux64 - debug builder': 'debug_x64',
       'V8 Clusterfuzz Linux64 ASAN no inline - release builder':
           'release_x64_asan_symbolized_verify_heap',
+      'V8 Clusterfuzz Linux ASAN no inline - release builder':
+          'release_x86_asan_symbolized_verify_heap',
       'V8 Clusterfuzz Linux64 ASAN - debug builder': 'debug_x64_asan',
+      'V8 Clusterfuzz Linux ASAN - debug builder': 'debug_x86_asan',
       'V8 Clusterfuzz Linux64 ASAN arm64 - debug builder':
           'debug_simulate_arm64_asan',
+      'V8 Clusterfuzz Linux - debug builder': 'debug_x86',
       'V8 Clusterfuzz Linux ASAN arm - debug builder':
           'debug_simulate_arm_asan',
       'V8 Clusterfuzz Linux64 CFI - release builder':
@@ -202,19 +208,23 @@
       'v8_linux_gcc_compile_rel': 'release_x86_gcc_minimal_symbols',
       'v8_linux_gcc_rel_ng': 'release_x86_gcc_minimal_symbols',
       'v8_linux_shared_compile_rel': 'release_x86_shared_verify_heap',
+      'v8_linux_vtunejit': 'debug_x86_vtunejit',
       'v8_linux64_arm64_pointer_compression_rel_ng':
           'release_simulate_arm64_pointer_compression',
       'v8_linux64_dbg_ng': 'debug_x64_trybot',
       'v8_linux64_dict_tracking_dbg_ng': 'debug_x64_dict_tracking_trybot',
       'v8_linux64_gc_stress_custom_snapshot_dbg_ng': 'debug_x64_trybot_custom',
       'v8_linux64_gcc_compile_dbg': 'debug_x64_gcc',
+      'v8_linux64_gcov_coverage': 'release_x64_gcc_coverage',
       'v8_linux64_header_includes_dbg': 'debug_x64_header_includes',
+      'v8_linux64_heap_sandbox_dbg_ng': 'debug_x64_heap_sandbox',
       'v8_linux64_fyi_rel_ng': 'release_x64_test_features_trybot',
       'v8_linux64_nodcheck_rel_ng': 'release_x64',
       'v8_linux64_perfetto_dbg_ng': 'debug_x64_perfetto',
       'v8_linux64_pointer_compression_rel_ng': 'release_x64_pointer_compression',
       'v8_linux64_rel_ng': 'release_x64_test_features_trybot',
       'v8_linux64_shared_compile_rel': 'release_x64_shared_verify_heap',
+      'v8_linux64_single_generation_dbg_ng': 'debug_x64_single_generation',
       'v8_linux64_no_wasm_compile_rel': 'release_x64_webassembly_disabled',
       'v8_linux64_verify_csa_rel_ng': 'release_x64_verify_csa',
       'v8_linux64_asan_rel_ng': 'release_x64_asan_minimal_symbols',
@@ -464,8 +474,9 @@
     'release_x64_cfi_clusterfuzz': [
       'release_bot', 'x64', 'cfi_clusterfuzz'],
     'release_x64_fuzzilli': [
-      'release_bot', 'x64', 'dcheck_always_on', 'v8_enable_slow_dchecks', 'v8_verify_heap',
-      'v8_verify_csa', 'v8_enable_verify_predictable', 'fuzzilli'],
+      'release_bot', 'x64', 'dcheck_always_on', 'v8_enable_slow_dchecks',
+      'v8_verify_heap', 'v8_verify_csa', 'v8_enable_verify_predictable',
+      'fuzzilli'],
     'release_x64_msvc': [
       'release_bot_no_goma', 'x64', 'minimal_symbols', 'msvc'],
     'release_x64_correctness_fuzzer' : [
@@ -475,8 +486,8 @@
     'release_x64_fuchsia_trybot': [
       'release_trybot', 'x64', 'fuchsia'],
     'release_x64_gcc_coverage': [
-      'release_bot_no_goma', 'x64', 'coverage', 'gcc', 'no_custom_libcxx',
-      'no_sysroot'],
+      'release_bot_no_goma', 'x64', 'coverage', 'gcc', 'lld',
+      'no_custom_libcxx', 'no_sysroot'],
     'release_x64_ios_simulator': [
       'release_bot', 'x64', 'ios_simulator'],
     'release_x64_internal': [
@@ -529,13 +540,17 @@
     'debug_x64_fuchsia': [
       'debug_bot', 'x64', 'fuchsia'],
     'debug_x64_gcc': [
-      'debug_bot_no_goma', 'x64', 'gcc', 'v8_check_header_includes'],
+      'debug_bot_no_goma', 'x64', 'gcc', 'lld', 'v8_check_header_includes'],
     'debug_x64_header_includes': [
       'debug_bot', 'x64', 'v8_check_header_includes'],
+    'debug_x64_heap_sandbox': [
+      'debug_bot', 'x64', 'v8_enable_heap_sandbox'],
     'debug_x64_minimal_symbols': [
       'debug_bot', 'x64', 'minimal_symbols'],
     'debug_x64_perfetto': [
       'debug_bot', 'x64', 'perfetto'],
+    'debug_x64_single_generation': [
+      'debug_bot', 'x64', 'v8_enable_single_generation'],
     'debug_x64_trybot': [
       'debug_trybot', 'x64'],
     'debug_x64_dict_tracking_trybot': [
@@ -548,6 +563,8 @@
     # Debug configs for x86.
     'debug_x86': [
       'debug_bot', 'x86'],
+    'debug_x86_asan': [
+      'debug_bot', 'x86', 'asan', 'lsan'],
     'debug_x86_minimal_symbols': [
       'debug_bot', 'x86', 'minimal_symbols'],
     'debug_x86_no_i18n': [
@@ -560,10 +577,13 @@
       'debug', 'x86', 'goma', 'v8_enable_slow_dchecks', 'v8_full_debug'],
 
     # Release configs for x86.
+    'release_x86_asan_symbolized_verify_heap': [
+      'release_bot', 'x86', 'asan', 'lsan', 'symbolized',
+      'v8_verify_heap'],
     'release_x86_gcc': [
-      'release_bot_no_goma', 'x86', 'gcc', 'v8_check_header_includes'],
+      'release_bot_no_goma', 'x86', 'gcc', 'lld', 'v8_check_header_includes'],
     'release_x86_gcc_minimal_symbols': [
-      'release_bot_no_goma', 'x86', 'gcc', 'minimal_symbols',
+      'release_bot_no_goma', 'x86', 'gcc', 'lld', 'minimal_symbols',
       'v8_check_header_includes'],
     'release_x86_gcmole': [
       'release_bot', 'x86', 'gcmole'],
@@ -645,7 +665,7 @@
     'debug_bot': {
       'mixins': [
         'debug', 'shared', 'goma', 'v8_enable_slow_dchecks',
-        'v8_optimized_debug'],
+        'v8_optimized_debug', 'v8_enable_google_benchmark'],
     },
 
     'debug_bot_no_goma': {
@@ -701,6 +721,10 @@
       'gn_args': 'target_cpu="x64" target_os="ios"',
     },
 
+    'lld': {
+      'gn_args': 'use_lld=true',
+    },
+
     'lsan': {
       'mixins': ['v8_enable_test_features'],
       'gn_args': 'is_lsan=true',
@@ -745,7 +769,7 @@
     },
 
     'release_bot': {
-      'mixins': ['release', 'static', 'goma'],
+      'mixins': ['release', 'static', 'goma', 'v8_enable_google_benchmark'],
     },
 
     'release_bot_no_goma': {
@@ -834,6 +858,10 @@
       'gn_args': 'v8_control_flow_integrity=true',
     },
 
+    'v8_enable_heap_sandbox': {
+      'gn_args': 'v8_enable_heap_sandbox=true',
+    },
+
     'v8_enable_lite_mode': {
       'gn_args': 'v8_enable_lite_mode=true',
     },
@@ -842,6 +870,10 @@
       'gn_args': 'v8_enable_slow_dchecks=true',
     },
 
+    'v8_enable_google_benchmark': {
+      'gn_args': 'v8_enable_google_benchmark=true',
+    },
+
     'webassembly_disabled': {
       'gn_args': 'v8_enable_webassembly=false',
     },
@@ -853,7 +885,10 @@
     'v8_disable_pointer_compression': {
       'gn_args': 'v8_enable_pointer_compression=false',
     },
-
+    'v8_enable_single_generation': {
+      'gn_args': 'v8_enable_single_generation=true ' 
+                 'v8_disable_write_barriers=true',
+    },
     'v8_enable_test_features': {
       'gn_args': 'v8_enable_test_features=true',
     },
diff --git a/chromium/v8/infra/testing/builders.pyl b/chromium/v8/infra/testing/builders.pyl
index fc0d1c55b11..8fe8872ed9b 100644
--- a/chromium/v8/infra/testing/builders.pyl
+++ b/chromium/v8/infra/testing/builders.pyl
@@ -49,7 +49,7 @@
   # Fuchsia
   'v8_fuchsia_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'fuchsia-unittests'},
@@ -57,7 +57,7 @@
   },
   'V8 Fuchsia': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'fuchsia-unittests'},
@@ -68,7 +68,7 @@
   'v8_linux_dbg_ng_triggered': {
     'swarming_dimensions' : {
       'cpu': 'x86-64-avx2',
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'benchmarks'},
@@ -102,7 +102,7 @@
   },
   'v8_linux_gc_stress_dbg_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'mjsunit', 'variant': 'slow_path', 'test_args': ['--gc-stress'], 'shards': 2},
@@ -111,7 +111,7 @@
   },
   'v8_linux_gcc_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing'},
@@ -120,7 +120,7 @@
   'v8_linux_nodcheck_rel_ng_triggered': {
     'swarming_dimensions' : {
       'cpu': 'x86-64-avx2',
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'benchmarks'},
@@ -135,7 +135,7 @@
   },
   'v8_linux_noi18n_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'mozilla', 'variant': 'default'},
@@ -146,7 +146,7 @@
   'v8_linux_rel_ng_triggered': {
     'swarming_dimensions' : {
       'cpu': 'x86-64-avx2',
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'benchmarks'},
@@ -166,7 +166,7 @@
   'v8_linux_optional_rel_ng_triggered': {
     'swarming_dimensions' : {
       'cpu': 'x86-64-avx2',
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       # Code serializer.
@@ -268,7 +268,7 @@
   },
   'v8_linux_verify_csa_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing', 'shards': 2},
@@ -278,7 +278,7 @@
   # Linux32 with arm simulators
   'v8_linux_arm_dbg_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'mjsunit_sp_frame_access'},
@@ -291,7 +291,7 @@
   },
   'v8_linux_arm_lite_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing', 'variant': 'default', 'shards': 4},
@@ -299,7 +299,7 @@
   },
   'v8_linux_arm_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'mjsunit_sp_frame_access', 'shards': 2},
@@ -314,7 +314,7 @@
   # Linux64
   'v8_linux64_asan_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'test262', 'shards': 7},
@@ -325,7 +325,7 @@
   },
   'v8_linux64_cfi_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'benchmarks'},
@@ -338,7 +338,7 @@
   'v8_linux64_dbg_ng_triggered': {
     'swarming_dimensions' : {
       'cpu': 'x86-64-avx2',
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'benchmarks'},
@@ -360,7 +360,7 @@
   'v8_linux64_dict_tracking_dbg_ng_triggered': {
     'swarming_dimensions' : {
       'cpu': 'x86-64-avx2',
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing', 'shards': 3},
@@ -368,26 +368,14 @@
   },
   'v8_linux64_fuzzilli_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     # TODO(almuthanna): Add a new test config for the fuzzilli suite.
     'tests': [],
   },
-  'v8_linux64_gc_stress_custom_snapshot_dbg_ng_triggered': {
-    'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {
-        'name': 'mjsunit',
-        'test_args': ['--gc-stress', '--no-harness'],
-        'shards': 3,
-      },
-    ],
-  },
   'v8_linux64_fyi_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       # Infra staging.
@@ -401,11 +389,41 @@
       {'name': 'mjsunit', 'variant': 'experimental_regexp'},
       # Concurrent inlining.
       {'name': 'mjsunit', 'variant': 'concurrent_inlining'},
+      # Wasm write protect code space.
+      {'name': 'mjsunit', 'variant': 'wasm_write_protect_code'},
+    ],
+  },
+  'v8_linux64_gc_stress_custom_snapshot_dbg_ng_triggered': {
+    'swarming_dimensions' : {
+      'os': 'Ubuntu-18.04',
+    },
+    'tests': [
+      {
+        'name': 'mjsunit',
+        'test_args': ['--gc-stress', '--no-harness'],
+        'shards': 3,
+      },
+    ],
+  },
+  'v8_linux64_gcov_coverage': {
+    'swarming_dimensions' : {
+      'os': 'Ubuntu-18.04',
+    },
+    'tests': [
+      {'name': 'v8testing'},
+    ],
+  },
+  'v8_linux64_heap_sandbox_dbg_ng_triggered': {
+    'swarming_dimensions' : {
+      'os': 'Ubuntu-18.04',
+    },
+    'tests': [
+      {'name': 'v8testing', 'shards': 2},
     ],
   },
   'v8_linux64_msan_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'test262', 'variant': 'default', 'shards': 2},
@@ -415,7 +433,7 @@
   'v8_linux64_nodcheck_rel_ng_triggered': {
     'swarming_dimensions' : {
       'cpu': 'x86-64-avx2',
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'benchmarks'},
@@ -438,7 +456,7 @@
   },
   'v8_linux64_perfetto_dbg_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing', 'shards': 3},
@@ -446,7 +464,15 @@
   },
   'v8_linux64_pointer_compression_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
+    },
+    'tests': [
+      {'name': 'v8testing', 'shards': 3},
+    ],
+  },
+  'v8_linux64_single_generation_dbg_ng_triggered': {
+    'swarming_dimensions' : {
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing', 'shards': 3},
@@ -455,7 +481,7 @@
   'v8_linux64_rel_ng_triggered': {
     'swarming_dimensions' : {
       'cpu': 'x86-64-avx2',
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       # TODO(machenbach): Add benchmarks.
@@ -475,7 +501,7 @@
   },
   'v8_linux64_tsan_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'benchmarks'},
@@ -489,7 +515,7 @@
   },
   'v8_linux64_tsan_no_cm_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {
@@ -507,7 +533,7 @@
   },
   'v8_linux64_tsan_isolates_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing', 'test_args': ['--isolates'], 'shards': 7},
@@ -515,7 +541,7 @@
   },
   'v8_linux64_ubsan_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing', 'shards': 2},
@@ -523,7 +549,7 @@
   },
   'v8_linux64_verify_csa_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing', 'shards': 2},
@@ -533,7 +559,7 @@
   # Linux64 with arm64 simulators
   'v8_linux_arm64_dbg_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'mjsunit_sp_frame_access'},
@@ -546,7 +572,7 @@
   },
   'v8_linux_arm64_gc_stress_dbg_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'd8testing', 'test_args': ['--gc-stress'], 'shards': 12},
@@ -554,7 +580,7 @@
   },
   'v8_linux_arm64_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'mjsunit_sp_frame_access', 'shards': 4},
@@ -567,7 +593,7 @@
   },
   'v8_linux_arm64_cfi_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'test262', 'variant': 'default', 'shards': 3},
@@ -576,7 +602,7 @@
   },
   'v8_linux64_arm64_pointer_compression_rel_ng_triggered': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing', 'variant': 'default', 'shards': 4},
@@ -586,7 +612,7 @@
   # Linux64 with RISC-V simulators
   'v8_linux64_riscv64_rel_ng_triggered': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing', 'shards': 3},
@@ -598,7 +624,7 @@
     'swarming_dimensions' : {
       'cores': '8',
       'cpu': 'armv7l-32-ODROID-XU4',
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu',
     },
     'swarming_task_attrs': {
       # Use same prio as CI due to limited resources.
@@ -760,6 +786,7 @@
     },
     'tests': [
       {'name': 'v8testing', 'shards': 8},
+      {'name': 'v8testing', 'variant': 'future', 'shards': 2},
     ],
   },
   'v8_mac_arm64_sim_dbg_ng_triggered': {
@@ -770,6 +797,7 @@
     },
     'tests': [
       {'name': 'v8testing', 'shards': 8},
+      {'name': 'v8testing', 'variant': 'future', 'shards': 2},
     ],
   },
   'v8_mac_arm64_sim_nodcheck_rel_ng_triggered': {
@@ -780,6 +808,7 @@
     },
     'tests': [
       {'name': 'v8testing', 'shards': 8},
+      {'name': 'v8testing', 'variant': 'future', 'shards': 2},
     ],
   },
   ##############################################################################
@@ -788,7 +817,7 @@
   # Main.
   'V8 Fuzzer': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'swarming_task_attrs': {
       'expiration': 14400,
@@ -802,7 +831,7 @@
   'V8 Linux': {
     'swarming_dimensions': {
       'cpu': 'x86-64-avx2',
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'benchmarks'},
@@ -873,7 +902,7 @@
   },
   'V8 Linux - arm64 - sim - CFI': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'test262', 'variant': 'default', 'shards': 3},
@@ -882,7 +911,7 @@
   },
   'V8 Linux - arm64 - sim - MSAN': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'test262', 'variant': 'default', 'shards': 3},
@@ -892,7 +921,7 @@
   'V8 Linux - debug': {
     'swarming_dimensions': {
       'cpu': 'x86-64-avx2',
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'benchmarks'},
@@ -991,7 +1020,7 @@
   },
   'V8 Linux - full debug': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing', 'variant': 'default', 'shards': 4},
@@ -999,7 +1028,7 @@
   },
   'V8 Linux - gc stress': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {
@@ -1017,7 +1046,7 @@
   },
   'V8 Linux - noi18n - debug': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'mozilla', 'variant': 'default'},
@@ -1027,7 +1056,7 @@
   },
   'V8 Linux - predictable': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'benchmarks'},
@@ -1037,7 +1066,7 @@
   },
   'V8 Linux - shared': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'mozilla'},
@@ -1047,7 +1076,7 @@
   },
   'V8 Linux - verify csa': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing'},
@@ -1055,7 +1084,7 @@
   },
   'V8 Linux gcc': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing'},
@@ -1064,7 +1093,7 @@
   'V8 Linux64': {
     'swarming_dimensions': {
       'cpu': 'x86-64-avx2',
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'benchmarks'},
@@ -1108,7 +1137,7 @@
   },
   'V8 Linux64 - cfi': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'benchmarks'},
@@ -1120,7 +1149,7 @@
   },
   'V8 Linux64 - custom snapshot - debug': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'mjsunit', 'test_args': ['--no-harness']},
@@ -1129,7 +1158,7 @@
   'V8 Linux64 - debug': {
     'swarming_dimensions': {
       'cpu': 'x86-64-avx2',
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'benchmarks'},
@@ -1171,7 +1200,7 @@
   'V8 Linux64 - dict tracking - debug': {
     'swarming_dimensions': {
       'cpu': 'x86-64-avx2',
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing', 'shards': 3},
@@ -1179,7 +1208,7 @@
   },
   'V8 Linux64 - debug - fyi': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       # Infra staging.
@@ -1193,11 +1222,13 @@
       {'name': 'mjsunit', 'variant': 'experimental_regexp'},
       # Concurrent inlining.
       {'name': 'mjsunit', 'variant': 'concurrent_inlining'},
+      # Wasm write protect code space.
+      {'name': 'mjsunit', 'variant': 'wasm_write_protect_code'},
     ],
   },
   'V8 Linux64 - debug - perfetto': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'swarming_task_attrs': {
       'expiration': 14400,
@@ -1208,9 +1239,22 @@
       {'name': 'v8testing', 'shards': 2},
     ],
   },
+  'V8 Linux64 - debug - single generation': {
+    'swarming_dimensions' : {
+      'os': 'Ubuntu-18.04',
+    },
+    'swarming_task_attrs': {
+      'expiration': 14400,
+      'hard_timeout': 3600,
+      'priority': 35,
+    },
+    'tests': [
+      {'name': 'v8testing', 'shards': 3},
+    ],
+  },
   'V8 Linux64 - fyi': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       # Infra staging.
@@ -1224,19 +1268,29 @@
       {'name': 'mjsunit', 'variant': 'experimental_regexp'},
       # Concurrent inlining.
       {'name': 'mjsunit', 'variant': 'concurrent_inlining'},
+      # Wasm write protect code space.
+      {'name': 'mjsunit', 'variant': 'wasm_write_protect_code'},
     ],
   },
   'V8 Linux64 - gcov coverage': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing'},
     ],
   },
+  'V8 Linux64 - heap sandbox - debug': {
+    'swarming_dimensions' : {
+      'os': 'Ubuntu-18.04',
+    },
+    'tests': [
+      {'name': 'v8testing', 'shards': 2},
+    ],
+  },
   'V8 Linux64 - internal snapshot': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing'},
@@ -1244,7 +1298,7 @@
   },
   'V8 Linux64 - pointer compression': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing', 'shards': 2},
@@ -1252,7 +1306,7 @@
   },
   'V8 Linux64 - shared': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'mozilla'},
@@ -1262,7 +1316,7 @@
   },
   'V8 Linux64 - verify csa': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing'},
@@ -1270,7 +1324,7 @@
   },
   'V8 Linux64 ASAN': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'test262', 'shards': 5},
@@ -1281,7 +1335,7 @@
   },
   'V8 Linux64 GC Stress - custom snapshot': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {
@@ -1293,7 +1347,7 @@
   },
   'V8 Linux64 TSAN': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'benchmarks'},
@@ -1307,7 +1361,7 @@
   },
   'V8 Linux64 TSAN - stress-incremental-marking': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'swarming_task_attrs': {
       'expiration': 14400,
@@ -1338,7 +1392,7 @@
   },
   'V8 Linux64 TSAN - isolates': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing', 'test_args': ['--isolates'], 'shards': 7},
@@ -1346,7 +1400,7 @@
   },
   'V8 Linux64 TSAN - no-concurrent-marking': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {
@@ -1364,7 +1418,7 @@
   },
   'V8 Linux64 UBSan': {
     'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'mozilla'},
@@ -1427,8 +1481,8 @@
       'priority': 35,
     },
     'tests': [
-      {'name': 'd8testing'},
-      {'name': 'd8testing', 'variant': 'extra'},
+      {'name': 'v8testing'},
+      {'name': 'v8testing', 'variant': 'extra'},
     ],
   },
   'V8 Mac - arm64 - debug': {
@@ -1460,6 +1514,7 @@
     },
     'tests': [
       {'name': 'v8testing', 'shards': 8},
+      {'name': 'v8testing', 'variant': 'future', 'shards': 2},
     ],
   },
   'V8 Mac - arm64 - sim - release': {
@@ -1475,6 +1530,7 @@
     },
     'tests': [
       {'name': 'v8testing', 'shards': 8},
+      {'name': 'v8testing', 'variant': 'future', 'shards': 2},
     ],
   },
   'V8 Win32': {
@@ -1558,7 +1614,7 @@
     'swarming_dimensions': {
       'cores': '8',
       'cpu': 'armv7l-32-ODROID-XU4',
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu',
     },
     'swarming_task_attrs': {
       'expiration': 21600,
@@ -1587,7 +1643,7 @@
     'swarming_dimensions': {
       'cores': '8',
       'cpu': 'armv7l-32-ODROID-XU4',
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu',
     },
     'swarming_task_attrs': {
       'expiration': 21600,
@@ -1615,7 +1671,7 @@
     'swarming_dimensions': {
       'cores': '8',
       'cpu': 'armv7l-32-ODROID-XU4',
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu',
     },
     'swarming_task_attrs': {
       'expiration': 21600,
@@ -1633,7 +1689,7 @@
   },
   'V8 Linux - arm - sim': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'mjsunit_sp_frame_access'},
@@ -1682,7 +1738,7 @@
   },
   'V8 Linux - arm - sim - debug': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'mjsunit_sp_frame_access', 'shards': 6},
@@ -1735,7 +1791,7 @@
   },
   'V8 Linux - arm - sim - lite': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing', 'variant': 'default', 'shards': 2},
@@ -1743,7 +1799,7 @@
   },
   'V8 Linux - arm - sim - lite - debug': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'v8testing', 'variant': 'default', 'shards': 4},
@@ -1751,7 +1807,7 @@
   },
   'V8 Linux - arm64 - sim': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'tests': [
       {'name': 'mjsunit_sp_frame_access'},
@@ -1764,7 +1820,7 @@
   },
   'V8 Linux - arm64 - sim - debug': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     # TODO(machenbach): Remove longer timeout when this builder scales better.
     'swarming_task_attrs': {
@@ -1781,7 +1837,7 @@
   },
   'V8 Linux - arm64 - sim - gc stress': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'swarming_task_attrs': {
       'expiration': 14400,
@@ -1798,7 +1854,7 @@
   },
   'V8 Linux - mips64el - sim': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'swarming_task_attrs': {
       'expiration': 14400,
@@ -1812,7 +1868,7 @@
   },
   'V8 Linux - mipsel - sim': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'swarming_task_attrs': {
       'expiration': 14400,
@@ -1826,7 +1882,7 @@
   },
   'V8 Linux - ppc64 - sim': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'swarming_task_attrs': {
       'expiration': 14400,
@@ -1839,7 +1895,7 @@
   },
   'V8 Linux - riscv64 - sim': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'swarming_task_attrs': {
       'expiration': 14400,
@@ -1852,7 +1908,7 @@
   },
   'V8 Linux - s390x - sim': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'swarming_task_attrs': {
       'expiration': 14400,
@@ -1865,7 +1921,7 @@
   },
   'V8 Linux64 - arm64 - sim - pointer compression': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'swarming_task_attrs': {
       'expiration': 14400,
@@ -1880,7 +1936,7 @@
   # Clusterfuzz.
   'V8 NumFuzz': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'swarming_task_attrs': {
       'expiration': 13800,
@@ -1897,7 +1953,7 @@
   },
   'V8 NumFuzz - TSAN': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'swarming_task_attrs': {
       'expiration': 13800,
@@ -1945,7 +2001,7 @@
   },
   'V8 NumFuzz - debug': {
     'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
+      'os': 'Ubuntu-18.04',
     },
     'swarming_task_attrs': {
       'expiration': 13800,
@@ -1998,282 +2054,4 @@
       },
     ],
   },
-  ##############################################################################
-  # Branches.
-  'V8 Linux - beta branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla'},
-      {'name': 'test262', 'variant': 'default'},
-      {'name': 'v8testing'},
-    ],
-  },
-  'V8 Linux - beta branch - debug': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla'},
-      {'name': 'test262', 'variant': 'default'},
-      {'name': 'v8testing', 'shards': 3},
-    ],
-  },
-  'V8 Linux - stable branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla'},
-      {'name': 'test262', 'variant': 'default'},
-      {'name': 'v8testing'},
-    ],
-  },
-  'V8 Linux - stable branch - debug': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla'},
-      {'name': 'test262', 'variant': 'default'},
-      {'name': 'v8testing', 'shards': 3},
-    ],
-  },
-  'V8 Linux - previous branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla'},
-      {'name': 'test262', 'variant': 'default'},
-      {'name': 'v8testing'},
-    ],
-  },
-  'V8 Linux - previous branch - debug': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla'},
-      {'name': 'test262', 'variant': 'default'},
-      {'name': 'v8testing', 'shards': 3},
-    ],
-  },
-  'V8 Linux64 - beta branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla'},
-      {'name': 'test262', 'variant': 'default'},
-      {'name': 'v8testing'},
-    ],
-  },
-  'V8 Linux64 - beta branch - debug': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla'},
-      {'name': 'test262', 'variant': 'default'},
-      {'name': 'v8testing', 'shards': 3},
-    ],
-  },
-  'V8 Linux64 - stable branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla'},
-      {'name': 'test262', 'variant': 'default'},
-      {'name': 'v8testing'},
-    ],
-  },
-  'V8 Linux64 - stable branch - debug': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla'},
-      {'name': 'test262', 'variant': 'default'},
-      {'name': 'v8testing', 'shards': 3},
-    ],
-  },
-  'V8 Linux64 - previous branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla'},
-      {'name': 'test262', 'variant': 'default'},
-      {'name': 'v8testing'},
-    ],
-  },
-  'V8 Linux64 - previous branch - debug': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla'},
-      {'name': 'test262', 'variant': 'default'},
-      {'name': 'v8testing', 'shards': 3},
-    ],
-  },
-  'V8 arm - sim - beta branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla'},
-      {'name': 'test262', 'variant': 'default'},
-      {'name': 'v8testing', 'shards': 4},
-    ],
-  },
-  'V8 arm - sim - beta branch - debug': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla', 'shards': 2},
-      {'name': 'test262', 'variant': 'default', 'shards': 2},
-      {'name': 'v8testing', 'shards': 10},
-    ],
-  },
-  'V8 arm - sim - stable branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla'},
-      {'name': 'test262', 'variant': 'default'},
-      {'name': 'v8testing', 'shards': 4},
-    ],
-  },
-  'V8 arm - sim - stable branch - debug': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla', 'shards': 2},
-      {'name': 'test262', 'variant': 'default', 'shards': 2},
-      {'name': 'v8testing', 'shards': 10},
-    ],
-  },
-  'V8 arm - sim - previous branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla'},
-      {'name': 'test262', 'variant': 'default'},
-      {'name': 'v8testing', 'shards': 4},
-    ],
-  },
-  'V8 arm - sim - previous branch - debug': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'mozilla', 'shards': 2},
-      {'name': 'test262', 'variant': 'default', 'shards': 2},
-      {'name': 'v8testing', 'shards': 10},
-    ],
-  },
-  'V8 mips64el - sim - beta branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'unittests'},
-    ],
-  },
-  'V8 mips64el - sim - stable branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'unittests'},
-    ],
-  },
-  'V8 mips64el - sim - previous branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'unittests'},
-    ],
-  },
-  'V8 mipsel - sim - beta branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'v8testing', 'shards': 4},
-    ],
-  },
-  'V8 mipsel - sim - stable branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'v8testing', 'shards': 4},
-    ],
-  },
-  'V8 mipsel - sim - previous branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'v8testing', 'shards': 4},
-    ],
-  },
-  'V8 ppc64 - sim - beta branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'unittests'},
-    ],
-  },
-  'V8 ppc64 - sim - stable branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'unittests'},
-    ],
-  },
-  'V8 ppc64 - sim - previous branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'unittests'},
-    ],
-  },
-  'V8 s390x - sim - beta branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'unittests'},
-    ],
-  },
-  'V8 s390x - sim - stable branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'unittests'},
-    ],
-  },
-  'V8 s390x - sim - previous branch': {
-    'swarming_dimensions': {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'unittests'},
-    ],
-  },
 }
diff --git a/chromium/v8/samples/OWNERS b/chromium/v8/samples/OWNERS
index 9c4f2439aa5..6df8720dc57 100644
--- a/chromium/v8/samples/OWNERS
+++ b/chromium/v8/samples/OWNERS
@@ -1,2 +1,2 @@
 mathias@chromium.org
-yangguo@chromium.org
+cbruni@chromium.org
diff --git a/chromium/v8/samples/shell.cc b/chromium/v8/samples/shell.cc
index e844ca51bf3..7de600a88fd 100644
--- a/chromium/v8/samples/shell.cc
+++ b/chromium/v8/samples/shell.cc
@@ -147,20 +147,17 @@ void Print(const v8::FunctionCallbackInfo<v8::Value>& args) {
 // the argument into a JavaScript string.
 void Read(const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() != 1) {
-    args.GetIsolate()->ThrowException(
-        v8::String::NewFromUtf8Literal(args.GetIsolate(), "Bad parameters"));
+    args.GetIsolate()->ThrowError("Bad parameters");
     return;
   }
   v8::String::Utf8Value file(args.GetIsolate(), args[0]);
   if (*file == NULL) {
-    args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
-        args.GetIsolate(), "Error loading file"));
+    args.GetIsolate()->ThrowError("Error loading file");
     return;
   }
   v8::Local<v8::String> source;
   if (!ReadFile(args.GetIsolate(), *file).ToLocal(&source)) {
-    args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
-        args.GetIsolate(), "Error loading file"));
+    args.GetIsolate()->ThrowError("Error loading file");
     return;
   }
 
@@ -175,19 +172,16 @@ void Load(const v8::FunctionCallbackInfo<v8::Value>& args) {
     v8::HandleScope handle_scope(args.GetIsolate());
     v8::String::Utf8Value file(args.GetIsolate(), args[i]);
     if (*file == NULL) {
-      args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
-          args.GetIsolate(), "Error loading file"));
+      args.GetIsolate()->ThrowError("Error loading file");
       return;
     }
     v8::Local<v8::String> source;
     if (!ReadFile(args.GetIsolate(), *file).ToLocal(&source)) {
-      args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
-          args.GetIsolate(), "Error loading file"));
+      args.GetIsolate()->ThrowError("Error loading file");
       return;
     }
     if (!ExecuteString(args.GetIsolate(), source, args[i], false, false)) {
-      args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
-          args.GetIsolate(), "Error executing file"));
+      args.GetIsolate()->ThrowError("Error executing file");
       return;
     }
   }
diff --git a/chromium/v8/src/DEPS b/chromium/v8/src/DEPS
index c3394e4b7a8..3c5dca663f6 100644
--- a/chromium/v8/src/DEPS
+++ b/chromium/v8/src/DEPS
@@ -5,6 +5,7 @@ include_rules = [
   "+src/asmjs/asm-js.h",
   "-src/baseline",
   "+src/baseline/baseline.h",
+  "+src/baseline/baseline-osr-inl.h",
   "+src/baseline/bytecode-offset-iterator.h",
   "-src/bigint",
   "+src/bigint/bigint.h",
@@ -14,6 +15,7 @@ include_rules = [
   "+src/compiler/wasm-compiler.h",
   "-src/heap",
   "+src/heap/basic-memory-chunk.h",
+  "+src/heap/code-range.h",
   "+src/heap/combined-heap.h",
   "+src/heap/embedder-tracing.h",
   "+src/heap/factory.h",
diff --git a/chromium/v8/src/api/api-arguments-inl.h b/chromium/v8/src/api/api-arguments-inl.h
index 57b533c7c9f..4edd0dad29d 100644
--- a/chromium/v8/src/api/api-arguments-inl.h
+++ b/chromium/v8/src/api/api-arguments-inl.h
@@ -96,8 +96,7 @@ inline JSReceiver FunctionCallbackArguments::holder() {
       Handle<InterceptorInfo> interceptor, Handle<Name> name) {               \
     DCHECK_NAME_COMPATIBLE(interceptor, name);                                \
     Isolate* isolate = this->isolate();                                       \
-    RuntimeCallTimerScope timer(                                              \
-        isolate, RuntimeCallCounterId::kNamed##FUNCTION##Callback);           \
+    RCS_SCOPE(isolate, RuntimeCallCounterId::kNamed##FUNCTION##Callback);     \
     Handle<Object> receiver_check_unsupported;                                \
     GenericNamedProperty##FUNCTION##Callback f =                              \
         ToCData<GenericNamedProperty##FUNCTION##Callback>(                    \
@@ -120,8 +119,7 @@ FOR_EACH_CALLBACK(CREATE_NAMED_CALLBACK)
       Handle<InterceptorInfo> interceptor, uint32_t index) {                  \
     DCHECK(!interceptor->is_named());                                         \
     Isolate* isolate = this->isolate();                                       \
-    RuntimeCallTimerScope timer(                                              \
-        isolate, RuntimeCallCounterId::kIndexed##FUNCTION##Callback);         \
+    RCS_SCOPE(isolate, RuntimeCallCounterId::kIndexed##FUNCTION##Callback);   \
     Handle<Object> receiver_check_unsupported;                                \
     IndexedProperty##FUNCTION##Callback f =                                   \
         ToCData<IndexedProperty##FUNCTION##Callback>(interceptor->TYPE());    \
@@ -142,7 +140,7 @@ FOR_EACH_CALLBACK(CREATE_INDEXED_CALLBACK)
 Handle<Object> FunctionCallbackArguments::Call(CallHandlerInfo handler) {
   Isolate* isolate = this->isolate();
   LOG(isolate, ApiObjectAccess("call", holder()));
-  RuntimeCallTimerScope timer(isolate, RuntimeCallCounterId::kFunctionCallback);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kFunctionCallback);
   v8::FunctionCallback f =
       v8::ToCData<v8::FunctionCallback>(handler.callback());
   Handle<Object> receiver_check_unsupported;
@@ -163,8 +161,7 @@ Handle<JSObject> PropertyCallbackArguments::CallNamedEnumerator(
     Handle<InterceptorInfo> interceptor) {
   DCHECK(interceptor->is_named());
   LOG(isolate(), ApiObjectAccess("interceptor-named-enumerator", holder()));
-  RuntimeCallTimerScope timer(isolate(),
-                              RuntimeCallCounterId::kNamedEnumeratorCallback);
+  RCS_SCOPE(isolate(), RuntimeCallCounterId::kNamedEnumeratorCallback);
   return CallPropertyEnumerator(interceptor);
 }
 
@@ -172,8 +169,7 @@ Handle<JSObject> PropertyCallbackArguments::CallIndexedEnumerator(
     Handle<InterceptorInfo> interceptor) {
   DCHECK(!interceptor->is_named());
   LOG(isolate(), ApiObjectAccess("interceptor-indexed-enumerator", holder()));
-  RuntimeCallTimerScope timer(isolate(),
-                              RuntimeCallCounterId::kIndexedEnumeratorCallback);
+  RCS_SCOPE(isolate(), RuntimeCallCounterId::kIndexedEnumeratorCallback);
   return CallPropertyEnumerator(interceptor);
 }
 
@@ -181,8 +177,7 @@ Handle<Object> PropertyCallbackArguments::CallNamedGetter(
     Handle<InterceptorInfo> interceptor, Handle<Name> name) {
   DCHECK_NAME_COMPATIBLE(interceptor, name);
   Isolate* isolate = this->isolate();
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kNamedGetterCallback);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kNamedGetterCallback);
   LOG(isolate,
       ApiNamedPropertyAccess("interceptor-named-getter", holder(), *name));
   GenericNamedPropertyGetterCallback f =
@@ -194,8 +189,7 @@ Handle<Object> PropertyCallbackArguments::CallNamedDescriptor(
     Handle<InterceptorInfo> interceptor, Handle<Name> name) {
   DCHECK_NAME_COMPATIBLE(interceptor, name);
   Isolate* isolate = this->isolate();
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kNamedDescriptorCallback);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kNamedDescriptorCallback);
   LOG(isolate,
       ApiNamedPropertyAccess("interceptor-named-descriptor", holder(), *name));
   GenericNamedPropertyDescriptorCallback f =
@@ -222,8 +216,7 @@ Handle<Object> PropertyCallbackArguments::CallNamedSetter(
   GenericNamedPropertySetterCallback f =
       ToCData<GenericNamedPropertySetterCallback>(interceptor->setter());
   Isolate* isolate = this->isolate();
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kNamedSetterCallback);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kNamedSetterCallback);
   PREPARE_CALLBACK_INFO_FAIL_SIDE_EFFECT_CHECK(isolate, f, Handle<Object>,
                                                v8::Value);
   LOG(isolate,
@@ -237,8 +230,7 @@ Handle<Object> PropertyCallbackArguments::CallNamedDefiner(
     const v8::PropertyDescriptor& desc) {
   DCHECK_NAME_COMPATIBLE(interceptor, name);
   Isolate* isolate = this->isolate();
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kNamedDefinerCallback);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kNamedDefinerCallback);
   GenericNamedPropertyDefinerCallback f =
       ToCData<GenericNamedPropertyDefinerCallback>(interceptor->definer());
   PREPARE_CALLBACK_INFO_FAIL_SIDE_EFFECT_CHECK(isolate, f, Handle<Object>,
@@ -253,8 +245,7 @@ Handle<Object> PropertyCallbackArguments::CallIndexedSetter(
     Handle<InterceptorInfo> interceptor, uint32_t index, Handle<Object> value) {
   DCHECK(!interceptor->is_named());
   Isolate* isolate = this->isolate();
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kIndexedSetterCallback);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kIndexedSetterCallback);
   IndexedPropertySetterCallback f =
       ToCData<IndexedPropertySetterCallback>(interceptor->setter());
   PREPARE_CALLBACK_INFO_FAIL_SIDE_EFFECT_CHECK(isolate, f, Handle<Object>,
@@ -270,8 +261,7 @@ Handle<Object> PropertyCallbackArguments::CallIndexedDefiner(
     const v8::PropertyDescriptor& desc) {
   DCHECK(!interceptor->is_named());
   Isolate* isolate = this->isolate();
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kIndexedDefinerCallback);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kIndexedDefinerCallback);
   IndexedPropertyDefinerCallback f =
       ToCData<IndexedPropertyDefinerCallback>(interceptor->definer());
   PREPARE_CALLBACK_INFO_FAIL_SIDE_EFFECT_CHECK(isolate, f, Handle<Object>,
@@ -286,8 +276,7 @@ Handle<Object> PropertyCallbackArguments::CallIndexedGetter(
     Handle<InterceptorInfo> interceptor, uint32_t index) {
   DCHECK(!interceptor->is_named());
   Isolate* isolate = this->isolate();
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kNamedGetterCallback);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kNamedGetterCallback);
   LOG(isolate,
       ApiIndexedPropertyAccess("interceptor-indexed-getter", holder(), index));
   IndexedPropertyGetterCallback f =
@@ -299,8 +288,7 @@ Handle<Object> PropertyCallbackArguments::CallIndexedDescriptor(
     Handle<InterceptorInfo> interceptor, uint32_t index) {
   DCHECK(!interceptor->is_named());
   Isolate* isolate = this->isolate();
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kIndexedDescriptorCallback);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kIndexedDescriptorCallback);
   LOG(isolate, ApiIndexedPropertyAccess("interceptor-indexed-descriptor",
                                         holder(), index));
   IndexedPropertyDescriptorCallback f =
@@ -338,8 +326,7 @@ Handle<JSObject> PropertyCallbackArguments::CallPropertyEnumerator(
 Handle<Object> PropertyCallbackArguments::CallAccessorGetter(
     Handle<AccessorInfo> info, Handle<Name> name) {
   Isolate* isolate = this->isolate();
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kAccessorGetterCallback);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kAccessorGetterCallback);
   LOG(isolate, ApiNamedPropertyAccess("accessor-getter", holder(), *name));
   AccessorNameGetterCallback f =
       ToCData<AccessorNameGetterCallback>(info->getter());
@@ -351,8 +338,7 @@ Handle<Object> PropertyCallbackArguments::CallAccessorSetter(
     Handle<AccessorInfo> accessor_info, Handle<Name> name,
     Handle<Object> value) {
   Isolate* isolate = this->isolate();
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kAccessorSetterCallback);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kAccessorSetterCallback);
   AccessorNameSetterCallback f =
       ToCData<AccessorNameSetterCallback>(accessor_info->setter());
   PREPARE_CALLBACK_INFO(isolate, f, Handle<Object>, void, accessor_info,
diff --git a/chromium/v8/src/api/api-inl.h b/chromium/v8/src/api/api-inl.h
index 849364e655c..84b9b288bb0 100644
--- a/chromium/v8/src/api/api-inl.h
+++ b/chromium/v8/src/api/api-inl.h
@@ -139,6 +139,7 @@ class V8_NODISCARD CallDepthScope {
   CallDepthScope(i::Isolate* isolate, Local<Context> context)
       : isolate_(isolate),
         context_(context),
+        did_enter_context_(false),
         escaped_(false),
         safe_for_termination_(isolate->next_v8_call_is_safe_for_termination()),
         interrupts_scope_(isolate_, i::StackGuard::TERMINATE_EXECUTION,
@@ -152,12 +153,11 @@ class V8_NODISCARD CallDepthScope {
     if (!context.IsEmpty()) {
       i::Handle<i::Context> env = Utils::OpenHandle(*context);
       i::HandleScopeImplementer* impl = isolate->handle_scope_implementer();
-      if (!isolate->context().is_null() &&
-          isolate->context().native_context() == env->native_context()) {
-        context_ = Local<Context>();
-      } else {
+      if (isolate->context().is_null() ||
+          isolate->context().native_context() != env->native_context()) {
         impl->SaveContext(isolate->context());
         isolate->set_context(*env);
+        did_enter_context_ = true;
       }
     }
     if (do_callback) isolate_->FireBeforeCallEnteredCallback();
@@ -165,16 +165,17 @@ class V8_NODISCARD CallDepthScope {
   ~CallDepthScope() {
     i::MicrotaskQueue* microtask_queue = isolate_->default_microtask_queue();
     if (!context_.IsEmpty()) {
-      i::HandleScopeImplementer* impl = isolate_->handle_scope_implementer();
-      isolate_->set_context(impl->RestoreContext());
+      if (did_enter_context_) {
+        i::HandleScopeImplementer* impl = isolate_->handle_scope_implementer();
+        isolate_->set_context(impl->RestoreContext());
+      }
 
       i::Handle<i::Context> env = Utils::OpenHandle(*context_);
       microtask_queue = env->native_context().microtask_queue();
     }
     if (!escaped_) isolate_->thread_local_top()->DecrementCallDepth(this);
     if (do_callback) isolate_->FireCallCompletedCallback(microtask_queue);
-// TODO(jochen): This should be #ifdef DEBUG
-#ifdef V8_CHECK_MICROTASKS_SCOPES_CONSISTENCY
+#ifdef DEBUG
     if (do_callback) {
       if (microtask_queue && microtask_queue->microtasks_policy() ==
                                  v8::MicrotasksPolicy::kScoped) {
@@ -213,9 +214,9 @@ class V8_NODISCARD CallDepthScope {
 
   i::Isolate* const isolate_;
   Local<Context> context_;
-  bool escaped_;
-  bool do_callback_;
-  bool safe_for_termination_;
+  bool did_enter_context_ : 1;
+  bool escaped_ : 1;
+  bool safe_for_termination_ : 1;
   i::InterruptsScope interrupts_scope_;
   i::Address previous_stack_height_;
 
diff --git a/chromium/v8/src/api/api-macros.h b/chromium/v8/src/api/api-macros.h
index b126e1cd5a0..9b339321e7a 100644
--- a/chromium/v8/src/api/api-macros.h
+++ b/chromium/v8/src/api/api-macros.h
@@ -30,9 +30,9 @@
  * TODO(jochen): Remove calls form API methods to DO_NOT_USE macros.
  */
 
-#define LOG_API(isolate, class_name, function_name)                           \
-  i::RuntimeCallTimerScope _runtime_timer(                                    \
-      isolate, i::RuntimeCallCounterId::kAPI_##class_name##_##function_name); \
+#define LOG_API(isolate, class_name, function_name)                        \
+  RCS_SCOPE(isolate,                                                       \
+            i::RuntimeCallCounterId::kAPI_##class_name##_##function_name); \
   LOG(isolate, ApiEntryCall("v8::" #class_name "::" #function_name))
 
 #define ENTER_V8_DO_NOT_USE(isolate) i::VMState<v8::OTHER> __state__((isolate))
@@ -126,7 +126,3 @@
   EXCEPTION_BAILOUT_CHECK_SCOPED_DO_NOT_USE(isolate, Nothing<T>())
 
 #define RETURN_ESCAPED(value) return handle_scope.Escape(value);
-
-// TODO(jochen): This should be #ifdef DEBUG
-#ifdef V8_CHECK_MICROTASKS_SCOPES_CONSISTENCY
-#endif
diff --git a/chromium/v8/src/api/api-natives.cc b/chromium/v8/src/api/api-natives.cc
index 56bf5bd47c4..46d54f6f587 100644
--- a/chromium/v8/src/api/api-natives.cc
+++ b/chromium/v8/src/api/api-natives.cc
@@ -74,9 +74,9 @@ MaybeHandle<Object> DefineAccessorProperty(Isolate* isolate,
                                            Handle<Object> setter,
                                            PropertyAttributes attributes) {
   DCHECK(!getter->IsFunctionTemplateInfo() ||
-         !FunctionTemplateInfo::cast(*getter).do_not_cache());
+         FunctionTemplateInfo::cast(*getter).should_cache());
   DCHECK(!setter->IsFunctionTemplateInfo() ||
-         !FunctionTemplateInfo::cast(*setter).do_not_cache());
+         FunctionTemplateInfo::cast(*setter).should_cache());
   if (getter->IsFunctionTemplateInfo() &&
       FunctionTemplateInfo::cast(*getter).BreakAtEntry()) {
     ASSIGN_RETURN_ON_EXCEPTION(
@@ -184,8 +184,7 @@ Object GetIntrinsic(Isolate* isolate, v8::Intrinsic intrinsic) {
 template <typename TemplateInfoT>
 MaybeHandle<JSObject> ConfigureInstance(Isolate* isolate, Handle<JSObject> obj,
                                         Handle<TemplateInfoT> data) {
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kConfigureInstance);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kConfigureInstance);
   HandleScope scope(isolate);
   // Disable access checks while instantiating the object.
   AccessCheckDisableScope access_check_scope(isolate, obj);
@@ -288,16 +287,20 @@ enum class CachingMode { kLimited, kUnlimited };
 MaybeHandle<JSObject> ProbeInstantiationsCache(
     Isolate* isolate, Handle<NativeContext> native_context, int serial_number,
     CachingMode caching_mode) {
-  DCHECK_LE(1, serial_number);
-  if (serial_number <= TemplateInfo::kFastTemplateInstantiationsCacheSize) {
+  DCHECK_NE(serial_number, TemplateInfo::kDoNotCache);
+  if (serial_number == TemplateInfo::kUncached) {
+    return {};
+  }
+
+  if (serial_number < TemplateInfo::kFastTemplateInstantiationsCacheSize) {
     FixedArray fast_cache =
         native_context->fast_template_instantiations_cache();
-    Handle<Object> object{fast_cache.get(serial_number - 1), isolate};
+    Handle<Object> object{fast_cache.get(serial_number), isolate};
     if (object->IsTheHole(isolate)) return {};
     return Handle<JSObject>::cast(object);
   }
   if (caching_mode == CachingMode::kUnlimited ||
-      (serial_number <= TemplateInfo::kSlowTemplateInstantiationsCacheSize)) {
+      (serial_number < TemplateInfo::kSlowTemplateInstantiationsCacheSize)) {
     SimpleNumberDictionary slow_cache =
         native_context->slow_template_instantiations_cache();
     InternalIndex entry = slow_cache.FindEntry(isolate, serial_number);
@@ -310,19 +313,27 @@ MaybeHandle<JSObject> ProbeInstantiationsCache(
 
 void CacheTemplateInstantiation(Isolate* isolate,
                                 Handle<NativeContext> native_context,
-                                int serial_number, CachingMode caching_mode,
+                                Handle<TemplateInfo> data,
+                                CachingMode caching_mode,
                                 Handle<JSObject> object) {
-  DCHECK_LE(1, serial_number);
-  if (serial_number <= TemplateInfo::kFastTemplateInstantiationsCacheSize) {
+  DCHECK_NE(TemplateInfo::kDoNotCache, data->serial_number());
+
+  int serial_number = data->serial_number();
+  if (serial_number == TemplateInfo::kUncached) {
+    serial_number = isolate->heap()->GetNextTemplateSerialNumber();
+  }
+
+  if (serial_number < TemplateInfo::kFastTemplateInstantiationsCacheSize) {
     Handle<FixedArray> fast_cache =
         handle(native_context->fast_template_instantiations_cache(), isolate);
     Handle<FixedArray> new_cache =
-        FixedArray::SetAndGrow(isolate, fast_cache, serial_number - 1, object);
+        FixedArray::SetAndGrow(isolate, fast_cache, serial_number, object);
     if (*new_cache != *fast_cache) {
       native_context->set_fast_template_instantiations_cache(*new_cache);
     }
+    data->set_serial_number(serial_number);
   } else if (caching_mode == CachingMode::kUnlimited ||
-             (serial_number <=
+             (serial_number <
               TemplateInfo::kSlowTemplateInstantiationsCacheSize)) {
     Handle<SimpleNumberDictionary> cache =
         handle(native_context->slow_template_instantiations_cache(), isolate);
@@ -331,20 +342,28 @@ void CacheTemplateInstantiation(Isolate* isolate,
     if (*new_cache != *cache) {
       native_context->set_slow_template_instantiations_cache(*new_cache);
     }
+    data->set_serial_number(serial_number);
+  } else {
+    // we've overflowed the cache limit, no more caching
+    data->set_serial_number(TemplateInfo::kDoNotCache);
   }
 }
 
 void UncacheTemplateInstantiation(Isolate* isolate,
                                   Handle<NativeContext> native_context,
-                                  int serial_number, CachingMode caching_mode) {
-  DCHECK_LE(1, serial_number);
-  if (serial_number <= TemplateInfo::kFastTemplateInstantiationsCacheSize) {
+                                  Handle<TemplateInfo> data,
+                                  CachingMode caching_mode) {
+  int serial_number = data->serial_number();
+  if (serial_number < 0) return;
+
+  if (serial_number < TemplateInfo::kFastTemplateInstantiationsCacheSize) {
     FixedArray fast_cache =
         native_context->fast_template_instantiations_cache();
-    DCHECK(!fast_cache.get(serial_number - 1).IsUndefined(isolate));
-    fast_cache.set_undefined(serial_number - 1);
+    DCHECK(!fast_cache.get(serial_number).IsUndefined(isolate));
+    fast_cache.set_undefined(serial_number);
+    data->set_serial_number(TemplateInfo::kUncached);
   } else if (caching_mode == CachingMode::kUnlimited ||
-             (serial_number <=
+             (serial_number <
               TemplateInfo::kSlowTemplateInstantiationsCacheSize)) {
     Handle<SimpleNumberDictionary> cache =
         handle(native_context->slow_template_instantiations_cache(), isolate);
@@ -352,6 +371,7 @@ void UncacheTemplateInstantiation(Isolate* isolate,
     DCHECK(entry.is_found());
     cache = SimpleNumberDictionary::DeleteEntry(isolate, cache, entry);
     native_context->set_slow_template_instantiations_cache(*cache);
+    data->set_serial_number(TemplateInfo::kUncached);
   }
 }
 
@@ -371,23 +391,22 @@ MaybeHandle<JSObject> InstantiateObject(Isolate* isolate,
                                         Handle<ObjectTemplateInfo> info,
                                         Handle<JSReceiver> new_target,
                                         bool is_prototype) {
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kInstantiateObject);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kInstantiateObject);
   Handle<JSFunction> constructor;
-  int serial_number = info->serial_number();
+  bool should_cache = info->should_cache();
   if (!new_target.is_null()) {
     if (IsSimpleInstantiation(isolate, *info, *new_target)) {
       constructor = Handle<JSFunction>::cast(new_target);
     } else {
       // Disable caching for subclass instantiation.
-      serial_number = 0;
+      should_cache = false;
     }
   }
   // Fast path.
   Handle<JSObject> result;
-  if (serial_number) {
+  if (should_cache && info->is_cached()) {
     if (ProbeInstantiationsCache(isolate, isolate->native_context(),
-                                 serial_number, CachingMode::kLimited)
+                                 info->serial_number(), CachingMode::kLimited)
             .ToHandle(&result)) {
       return isolate->factory()->CopyJSObject(result);
     }
@@ -430,9 +449,9 @@ MaybeHandle<JSObject> InstantiateObject(Isolate* isolate,
     // TODO(dcarney): is this necessary?
     JSObject::MigrateSlowToFast(result, 0, "ApiNatives::InstantiateObject");
     // Don't cache prototypes.
-    if (serial_number) {
-      CacheTemplateInstantiation(isolate, isolate->native_context(),
-                                 serial_number, CachingMode::kLimited, result);
+    if (should_cache) {
+      CacheTemplateInstantiation(isolate, isolate->native_context(), info,
+                                 CachingMode::kLimited, result);
       result = isolate->factory()->CopyJSObject(result);
     }
   }
@@ -465,12 +484,11 @@ MaybeHandle<Object> GetInstancePrototype(Isolate* isolate,
 MaybeHandle<JSFunction> InstantiateFunction(
     Isolate* isolate, Handle<NativeContext> native_context,
     Handle<FunctionTemplateInfo> data, MaybeHandle<Name> maybe_name) {
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kInstantiateFunction);
-  int serial_number = data->serial_number();
-  if (serial_number) {
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kInstantiateFunction);
+  bool should_cache = data->should_cache();
+  if (should_cache && data->is_cached()) {
     Handle<JSObject> result;
-    if (ProbeInstantiationsCache(isolate, native_context, serial_number,
+    if (ProbeInstantiationsCache(isolate, native_context, data->serial_number(),
                                  CachingMode::kUnlimited)
             .ToHandle(&result)) {
       return Handle<JSFunction>::cast(result);
@@ -504,7 +522,7 @@ MaybeHandle<JSFunction> InstantiateFunction(
                                  GetInstancePrototype(isolate, parent),
                                  JSFunction);
       CHECK(parent_prototype->IsHeapObject());
-      JSObject::ForceSetPrototype(Handle<JSObject>::cast(prototype),
+      JSObject::ForceSetPrototype(isolate, Handle<JSObject>::cast(prototype),
                                   Handle<HeapObject>::cast(parent_prototype));
     }
   }
@@ -517,18 +535,16 @@ MaybeHandle<JSFunction> InstantiateFunction(
 
   Handle<JSFunction> function = ApiNatives::CreateApiFunction(
       isolate, native_context, data, prototype, function_type, maybe_name);
-  if (serial_number) {
+  if (should_cache) {
     // Cache the function.
-    CacheTemplateInstantiation(isolate, native_context, serial_number,
+    CacheTemplateInstantiation(isolate, native_context, data,
                                CachingMode::kUnlimited, function);
   }
   MaybeHandle<JSObject> result = ConfigureInstance(isolate, function, data);
   if (result.is_null()) {
     // Uncache on error.
-    if (serial_number) {
-      UncacheTemplateInstantiation(isolate, native_context, serial_number,
-                                   CachingMode::kUnlimited);
-    }
+    UncacheTemplateInstantiation(isolate, native_context, data,
+                                 CachingMode::kUnlimited);
     return MaybeHandle<JSFunction>();
   }
   data->set_published(true);
@@ -596,7 +612,8 @@ MaybeHandle<JSObject> ApiNatives::InstantiateRemoteObject(
   object_map->set_may_have_interesting_symbols(true);
 
   Handle<JSObject> object = isolate->factory()->NewJSObjectFromMap(object_map);
-  JSObject::ForceSetPrototype(object, isolate->factory()->null_value());
+  JSObject::ForceSetPrototype(isolate, object,
+                              isolate->factory()->null_value());
 
   return object;
 }
@@ -653,8 +670,7 @@ Handle<JSFunction> ApiNatives::CreateApiFunction(
     Isolate* isolate, Handle<NativeContext> native_context,
     Handle<FunctionTemplateInfo> obj, Handle<Object> prototype,
     InstanceType type, MaybeHandle<Name> maybe_name) {
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kCreateApiFunction);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kCreateApiFunction);
   Handle<SharedFunctionInfo> shared =
       FunctionTemplateInfo::GetOrCreateSharedFunctionInfo(isolate, obj,
                                                           maybe_name);
diff --git a/chromium/v8/src/api/api.cc b/chromium/v8/src/api/api.cc
index a5c658a7992..9d1e53d3bb6 100644
--- a/chromium/v8/src/api/api.cc
+++ b/chromium/v8/src/api/api.cc
@@ -568,7 +568,7 @@ StartupData SnapshotCreator::CreateBlob(
       i::GarbageCollectionReason::kSnapshotCreator);
   {
     i::HandleScope scope(isolate);
-    isolate->heap()->CompactWeakArrayLists(internal::AllocationType::kOld);
+    isolate->heap()->CompactWeakArrayLists();
   }
 
   i::Snapshot::ClearReconstructableDataForSerialization(
@@ -1093,9 +1093,13 @@ void Context::SetAlignedPointerInEmbedderData(int index, void* value) {
 
 // --- T e m p l a t e ---
 
-static void InitializeTemplate(i::TemplateInfo that, int type) {
+static void InitializeTemplate(i::TemplateInfo that, int type,
+                               bool do_not_cache) {
   that.set_number_of_properties(0);
   that.set_tag(type);
+  int serial_number =
+      do_not_cache ? i::TemplateInfo::kDoNotCache : i::TemplateInfo::kUncached;
+  that.set_serial_number(serial_number);
 }
 
 void Template::Set(v8::Local<Name> name, v8::Local<Data> value,
@@ -1105,15 +1109,18 @@ void Template::Set(v8::Local<Name> name, v8::Local<Data> value,
   ENTER_V8_NO_SCRIPT_NO_EXCEPTION(isolate);
   i::HandleScope scope(isolate);
   auto value_obj = Utils::OpenHandle(*value);
+
   Utils::ApiCheck(!value_obj->IsJSReceiver() || value_obj->IsTemplateInfo(),
                   "v8::Template::Set",
                   "Invalid value, must be a primitive or a Template");
+
+  // The template cache only performs shallow clones, if we set an
+  // ObjectTemplate as a property value then we can not cache the receiver
+  // template.
   if (value_obj->IsObjectTemplateInfo()) {
-    templ->set_serial_number(0);
-    if (templ->IsFunctionTemplateInfo()) {
-      i::Handle<i::FunctionTemplateInfo>::cast(templ)->set_do_not_cache(true);
-    }
+    templ->set_serial_number(i::TemplateInfo::kDoNotCache);
   }
+
   i::ApiNatives::AddDataProperty(isolate, templ, Utils::OpenHandle(*name),
                                  value_obj,
                                  static_cast<i::PropertyAttributes>(attribute));
@@ -1145,8 +1152,9 @@ void Template::SetAccessorProperty(v8::Local<v8::Name> name,
 }
 
 // --- F u n c t i o n   T e m p l a t e ---
-static void InitializeFunctionTemplate(i::FunctionTemplateInfo info) {
-  InitializeTemplate(info, Consts::FUNCTION_TEMPLATE);
+static void InitializeFunctionTemplate(i::FunctionTemplateInfo info,
+                                       bool do_not_cache) {
+  InitializeTemplate(info, Consts::FUNCTION_TEMPLATE, do_not_cache);
   info.set_flag(0);
 }
 
@@ -1177,7 +1185,7 @@ void FunctionTemplate::SetPrototypeProviderTemplate(
       Utils::OpenHandle(*prototype_provider);
   Utils::ApiCheck(self->GetPrototypeTemplate().IsUndefined(i_isolate),
                   "v8::FunctionTemplate::SetPrototypeProviderTemplate",
-                  "Protoype must be undefiend");
+                  "Protoype must be undefined");
   Utils::ApiCheck(self->GetParentTemplate().IsUndefined(i_isolate),
                   "v8::FunctionTemplate::SetPrototypeProviderTemplate",
                   "Prototype provider must be empty");
@@ -1210,7 +1218,7 @@ static Local<FunctionTemplate> FunctionTemplateNew(
     bool do_not_cache,
     v8::Local<Private> cached_property_name = v8::Local<Private>(),
     SideEffectType side_effect_type = SideEffectType::kHasSideEffect,
-    const CFunction* c_function = nullptr) {
+    const MemorySpan<const CFunction>& c_function_overloads = {}) {
   i::Handle<i::Struct> struct_obj = isolate->factory()->NewStruct(
       i::FUNCTION_TEMPLATE_INFO_TYPE, i::AllocationType::kOld);
   i::Handle<i::FunctionTemplateInfo> obj =
@@ -1219,14 +1227,8 @@ static Local<FunctionTemplate> FunctionTemplateNew(
     // Disallow GC until all fields of obj have acceptable types.
     i::DisallowGarbageCollection no_gc;
     i::FunctionTemplateInfo raw = *obj;
-    InitializeFunctionTemplate(raw);
+    InitializeFunctionTemplate(raw, do_not_cache);
     raw.set_length(length);
-    raw.set_do_not_cache(do_not_cache);
-    int next_serial_number = i::FunctionTemplateInfo::kInvalidSerialNumber;
-    if (!do_not_cache) {
-      next_serial_number = isolate->heap()->GetNextTemplateSerialNumber();
-    }
-    raw.set_serial_number(next_serial_number);
     raw.set_undetectable(false);
     raw.set_needs_access_check(false);
     raw.set_accept_any_receiver(true);
@@ -1241,7 +1243,7 @@ static Local<FunctionTemplate> FunctionTemplateNew(
   }
   if (callback != nullptr) {
     Utils::ToLocal(obj)->SetCallHandler(callback, data, side_effect_type,
-                                        c_function);
+                                        c_function_overloads);
   }
   return Utils::ToLocal(obj);
 }
@@ -1255,10 +1257,24 @@ Local<FunctionTemplate> FunctionTemplate::New(
   // function templates when the isolate is created for serialization.
   LOG_API(i_isolate, FunctionTemplate, New);
   ENTER_V8_NO_SCRIPT_NO_EXCEPTION(i_isolate);
-  auto templ = FunctionTemplateNew(i_isolate, callback, data, signature, length,
-                                   behavior, false, Local<Private>(),
-                                   side_effect_type, c_function);
-  return templ;
+  return FunctionTemplateNew(
+      i_isolate, callback, data, signature, length, behavior, false,
+      Local<Private>(), side_effect_type,
+      c_function ? MemorySpan<const CFunction>{c_function, 1}
+                 : MemorySpan<const CFunction>{});
+}
+
+Local<FunctionTemplate> FunctionTemplate::NewWithCFunctionOverloads(
+    Isolate* isolate, FunctionCallback callback, v8::Local<Value> data,
+    v8::Local<Signature> signature, int length, ConstructorBehavior behavior,
+    SideEffectType side_effect_type,
+    const MemorySpan<const CFunction>& c_function_overloads) {
+  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
+  LOG_API(i_isolate, FunctionTemplate, New);
+  ENTER_V8_NO_SCRIPT_NO_EXCEPTION(i_isolate);
+  return FunctionTemplateNew(i_isolate, callback, data, signature, length,
+                             behavior, false, Local<Private>(),
+                             side_effect_type, c_function_overloads);
 }
 
 Local<FunctionTemplate> FunctionTemplate::NewWithCache(
@@ -1289,10 +1305,10 @@ Local<AccessorSignature> AccessorSignature::New(
     (obj)->setter(*foreign);                                  \
   } while (false)
 
-void FunctionTemplate::SetCallHandler(FunctionCallback callback,
-                                      v8::Local<Value> data,
-                                      SideEffectType side_effect_type,
-                                      const CFunction* c_function) {
+void FunctionTemplate::SetCallHandler(
+    FunctionCallback callback, v8::Local<Value> data,
+    SideEffectType side_effect_type,
+    const MemorySpan<const CFunction>& c_function_overloads) {
   auto info = Utils::OpenHandle(this);
   EnsureNotPublished(info, "v8::FunctionTemplate::SetCallHandler");
   i::Isolate* isolate = info->GetIsolate();
@@ -1306,15 +1322,28 @@ void FunctionTemplate::SetCallHandler(FunctionCallback callback,
     data = v8::Undefined(reinterpret_cast<v8::Isolate*>(isolate));
   }
   obj->set_data(*Utils::OpenHandle(*data));
-  // Blink passes CFunction's constructed with the default constructor
-  // for non-fast calls, so we should check the address too.
-  if (c_function != nullptr && c_function->GetAddress()) {
-    i::FunctionTemplateInfo::SetCFunction(
-        isolate, info,
-        i::handle(*FromCData(isolate, c_function->GetAddress()), isolate));
-    i::FunctionTemplateInfo::SetCSignature(
-        isolate, info,
-        i::handle(*FromCData(isolate, c_function->GetTypeInfo()), isolate));
+  if (c_function_overloads.size() > 0) {
+    // Stores the data for a sequence of CFunction overloads into a single
+    // FixedArray, as [address_0, signature_0, ... address_n-1, signature_n-1].
+    i::Handle<i::FixedArray> function_overloads =
+        isolate->factory()->NewFixedArray(static_cast<int>(
+            c_function_overloads.size() *
+            i::FunctionTemplateInfo::kFunctionOverloadEntrySize));
+    int function_count = static_cast<int>(c_function_overloads.size());
+    for (int i = 0; i < function_count; i++) {
+      const CFunction& c_function = c_function_overloads.data()[i];
+      i::Handle<i::Object> address =
+          FromCData(isolate, c_function.GetAddress());
+      function_overloads->set(
+          i::FunctionTemplateInfo::kFunctionOverloadEntrySize * i, *address);
+      i::Handle<i::Object> signature =
+          FromCData(isolate, c_function.GetTypeInfo());
+      function_overloads->set(
+          i::FunctionTemplateInfo::kFunctionOverloadEntrySize * i + 1,
+          *signature);
+    }
+    i::FunctionTemplateInfo::SetCFunctionOverloads(isolate, info,
+                                                   function_overloads);
   }
   info->set_call_code(*obj, kReleaseStore);
 }
@@ -1442,13 +1471,8 @@ static Local<ObjectTemplate> ObjectTemplateNew(
     // Disallow GC until all fields of obj have acceptable types.
     i::DisallowGarbageCollection no_gc;
     i::ObjectTemplateInfo raw = *obj;
-    InitializeTemplate(raw, Consts::OBJECT_TEMPLATE);
+    InitializeTemplate(raw, Consts::OBJECT_TEMPLATE, do_not_cache);
     raw.set_data(0);
-    int next_serial_number = 0;
-    if (!do_not_cache) {
-      next_serial_number = isolate->heap()->GetNextTemplateSerialNumber();
-    }
-    raw.set_serial_number(next_serial_number);
     if (!constructor.IsEmpty()) {
       raw.set_constructor(*Utils::OpenHandle(*constructor));
     }
@@ -1920,26 +1944,44 @@ MaybeLocal<Value> Script::Run(Local<Context> context) {
   ENTER_V8(isolate, context, Script, Run, MaybeLocal<Value>(),
            InternalEscapableScope);
   i::HistogramTimerScope execute_timer(isolate->counters()->execute(), true);
-  i::AggregatingHistogramTimerScope timer(isolate->counters()->compile_lazy());
+  i::AggregatingHistogramTimerScope histogram_timer(
+      isolate->counters()->compile_lazy());
   i::TimerEventScope<i::TimerEventExecute> timer_scope(isolate);
   auto fun = i::Handle<i::JSFunction>::cast(Utils::OpenHandle(this));
 
   // TODO(crbug.com/1193459): remove once ablation study is completed
-  if (i::FLAG_script_run_delay) {
-    v8::base::OS::Sleep(
-        v8::base::TimeDelta::FromMilliseconds(i::FLAG_script_run_delay));
+  base::ElapsedTimer timer;
+  base::TimeDelta delta;
+  if (i::FLAG_script_delay > 0) {
+    delta = v8::base::TimeDelta::FromMillisecondsD(i::FLAG_script_delay);
   }
-  if (i::FLAG_script_run_delay_once && !isolate->did_run_script_delay()) {
-    v8::base::OS::Sleep(
-        v8::base::TimeDelta::FromMilliseconds(i::FLAG_script_run_delay_once));
+  if (i::FLAG_script_delay_once > 0 && !isolate->did_run_script_delay()) {
+    delta = v8::base::TimeDelta::FromMillisecondsD(i::FLAG_script_delay_once);
     isolate->set_did_run_script_delay(true);
   }
+  if (i::FLAG_script_delay_fraction > 0.0) {
+    timer.Start();
+  } else if (delta.InMicroseconds() > 0) {
+    timer.Start();
+    while (timer.Elapsed() < delta) {
+      // Busy wait.
+    }
+  }
 
   i::Handle<i::Object> receiver = isolate->global_proxy();
   Local<Value> result;
   has_pending_exception = !ToLocal<Value>(
       i::Execution::Call(isolate, fun, receiver, 0, nullptr), &result);
 
+  if (i::FLAG_script_delay_fraction > 0.0) {
+    delta = v8::base::TimeDelta::FromMillisecondsD(
+        timer.Elapsed().InMillisecondsF() * i::FLAG_script_delay_fraction);
+    timer.Restart();
+    while (timer.Elapsed() < delta) {
+      // Busy wait.
+    }
+  }
+
   RETURN_ON_FAILED_EXECUTION(Value);
   RETURN_ESCAPED(result);
 }
@@ -4053,34 +4095,56 @@ Maybe<bool> v8::Object::CreateDataProperty(v8::Local<v8::Context> context,
                                            v8::Local<Name> key,
                                            v8::Local<Value> value) {
   auto isolate = reinterpret_cast<i::Isolate*>(context->GetIsolate());
-  ENTER_V8(isolate, context, Object, CreateDataProperty, Nothing<bool>(),
-           i::HandleScope);
   i::Handle<i::JSReceiver> self = Utils::OpenHandle(this);
   i::Handle<i::Name> key_obj = Utils::OpenHandle(*key);
   i::Handle<i::Object> value_obj = Utils::OpenHandle(*value);
 
-  Maybe<bool> result = i::JSReceiver::CreateDataProperty(
-      isolate, self, key_obj, value_obj, Just(i::kDontThrow));
-  has_pending_exception = result.IsNothing();
-  RETURN_ON_FAILED_EXECUTION_PRIMITIVE(bool);
-  return result;
+  i::LookupIterator::Key lookup_key(isolate, key_obj);
+  i::LookupIterator it(isolate, self, lookup_key, i::LookupIterator::OWN);
+  if (self->IsJSProxy()) {
+    ENTER_V8(isolate, context, Object, CreateDataProperty, Nothing<bool>(),
+             i::HandleScope);
+    Maybe<bool> result =
+        i::JSReceiver::CreateDataProperty(&it, value_obj, Just(i::kDontThrow));
+    has_pending_exception = result.IsNothing();
+    RETURN_ON_FAILED_EXECUTION_PRIMITIVE(bool);
+    return result;
+  } else {
+    ENTER_V8_NO_SCRIPT(isolate, context, Object, CreateDataProperty,
+                       Nothing<bool>(), i::HandleScope);
+    Maybe<bool> result =
+        i::JSObject::CreateDataProperty(&it, value_obj, Just(i::kDontThrow));
+    has_pending_exception = result.IsNothing();
+    RETURN_ON_FAILED_EXECUTION_PRIMITIVE(bool);
+    return result;
+  }
 }
 
 Maybe<bool> v8::Object::CreateDataProperty(v8::Local<v8::Context> context,
                                            uint32_t index,
                                            v8::Local<Value> value) {
   auto isolate = reinterpret_cast<i::Isolate*>(context->GetIsolate());
-  ENTER_V8(isolate, context, Object, CreateDataProperty, Nothing<bool>(),
-           i::HandleScope);
   i::Handle<i::JSReceiver> self = Utils::OpenHandle(this);
   i::Handle<i::Object> value_obj = Utils::OpenHandle(*value);
 
   i::LookupIterator it(isolate, self, index, self, i::LookupIterator::OWN);
-  Maybe<bool> result =
-      i::JSReceiver::CreateDataProperty(&it, value_obj, Just(i::kDontThrow));
-  has_pending_exception = result.IsNothing();
-  RETURN_ON_FAILED_EXECUTION_PRIMITIVE(bool);
-  return result;
+  if (self->IsJSProxy()) {
+    ENTER_V8(isolate, context, Object, CreateDataProperty, Nothing<bool>(),
+             i::HandleScope);
+    Maybe<bool> result =
+        i::JSReceiver::CreateDataProperty(&it, value_obj, Just(i::kDontThrow));
+    has_pending_exception = result.IsNothing();
+    RETURN_ON_FAILED_EXECUTION_PRIMITIVE(bool);
+    return result;
+  } else {
+    ENTER_V8_NO_SCRIPT(isolate, context, Object, CreateDataProperty,
+                       Nothing<bool>(), i::HandleScope);
+    Maybe<bool> result =
+        i::JSObject::CreateDataProperty(&it, value_obj, Just(i::kDontThrow));
+    has_pending_exception = result.IsNothing();
+    RETURN_ON_FAILED_EXECUTION_PRIMITIVE(bool);
+    return result;
+  }
 }
 
 struct v8::PropertyDescriptor::PrivateData {
@@ -4330,17 +4394,27 @@ Local<Value> v8::Object::GetPrototype() {
 Maybe<bool> v8::Object::SetPrototype(Local<Context> context,
                                      Local<Value> value) {
   auto isolate = reinterpret_cast<i::Isolate*>(context->GetIsolate());
-  ENTER_V8(isolate, context, Object, SetPrototype, Nothing<bool>(),
-           i::HandleScope);
   auto self = Utils::OpenHandle(this);
   auto value_obj = Utils::OpenHandle(*value);
-  // We do not allow exceptions thrown while setting the prototype
-  // to propagate outside.
-  TryCatch try_catch(reinterpret_cast<v8::Isolate*>(isolate));
-  auto result =
-      i::JSReceiver::SetPrototype(self, value_obj, false, i::kThrowOnError);
-  has_pending_exception = result.IsNothing();
-  RETURN_ON_FAILED_EXECUTION_PRIMITIVE(bool);
+  if (self->IsJSProxy()) {
+    ENTER_V8(isolate, context, Object, SetPrototype, Nothing<bool>(),
+             i::HandleScope);
+    // We do not allow exceptions thrown while setting the prototype
+    // to propagate outside.
+    TryCatch try_catch(reinterpret_cast<v8::Isolate*>(isolate));
+    auto result = i::JSProxy::SetPrototype(i::Handle<i::JSProxy>::cast(self),
+                                           value_obj, false, i::kThrowOnError);
+    has_pending_exception = result.IsNothing();
+    RETURN_ON_FAILED_EXECUTION_PRIMITIVE(bool);
+  } else {
+    ENTER_V8_NO_SCRIPT_NO_EXCEPTION(isolate);
+    auto result = i::JSObject::SetPrototype(i::Handle<i::JSObject>::cast(self),
+                                            value_obj, false, i::kThrowOnError);
+    if (result.IsNothing()) {
+      isolate->clear_pending_exception();
+      return Nothing<bool>();
+    }
+  }
   return Just(true);
 }
 
@@ -5015,25 +5089,6 @@ Local<Value> Function::GetDebugName() const {
   return Utils::ToLocal(i::Handle<i::Object>(*name, self->GetIsolate()));
 }
 
-Local<Value> Function::GetDisplayName() const {
-  auto self = Utils::OpenHandle(this);
-  i::Isolate* isolate = self->GetIsolate();
-  ENTER_V8_NO_SCRIPT_NO_EXCEPTION(isolate);
-  if (!self->IsJSFunction()) {
-    return ToApiHandle<Primitive>(isolate->factory()->undefined_value());
-  }
-  auto func = i::Handle<i::JSFunction>::cast(self);
-  i::Handle<i::String> property_name =
-      isolate->factory()->InternalizeString(i::StaticCharVector("displayName"));
-  i::Handle<i::Object> value =
-      i::JSReceiver::GetDataProperty(func, property_name);
-  if (value->IsString()) {
-    i::Handle<i::String> name = i::Handle<i::String>::cast(value);
-    if (name->length() > 0) return Utils::ToLocal(name);
-  }
-  return ToApiHandle<Primitive>(isolate->factory()->undefined_value());
-}
-
 ScriptOrigin Function::GetScriptOrigin() const {
   auto self = Utils::OpenHandle(this);
   auto isolate = reinterpret_cast<v8::Isolate*>(self->GetIsolate());
@@ -5590,19 +5645,33 @@ Local<Value> Symbol::Description() const {
     // RO_SPACE. Since RO_SPACE objects are immovable we can use the
     // Handle(Address*) constructor with the address of the description
     // field in the Symbol object without needing an isolate.
-    DCHECK(!COMPRESS_POINTERS_BOOL);
+    DCHECK(!COMPRESS_POINTERS_IN_ISOLATE_CAGE_BOOL);
+#ifndef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
     i::Handle<i::HeapObject> ro_description(reinterpret_cast<i::Address*>(
         sym->GetFieldAddress(i::Symbol::kDescriptionOffset)));
     return Utils::ToLocal(ro_description);
+#else
+    isolate = reinterpret_cast<i::Isolate*>(Isolate::GetCurrent());
+#endif
   }
 
-  i::Handle<i::Object> description(sym->description(), isolate);
+  return Description(reinterpret_cast<Isolate*>(isolate));
+}
 
+Local<Value> Symbol::Description(Isolate* isolate) const {
+  i::Handle<i::Symbol> sym = Utils::OpenHandle(this);
+  i::Handle<i::Object> description(sym->description(),
+                                   reinterpret_cast<i::Isolate*>(isolate));
   return Utils::ToLocal(description);
 }
 
 Local<Value> Private::Name() const {
-  return reinterpret_cast<const Symbol*>(this)->Description();
+  const Symbol* sym = reinterpret_cast<const Symbol*>(this);
+  i::Handle<i::Symbol> i_sym = Utils::OpenHandle(sym);
+  // v8::Private symbols are created by API and are therefore writable, so we
+  // can always recover an Isolate.
+  i::Isolate* isolate = i::GetIsolateFromWritableObject(*i_sym);
+  return sym->Description(reinterpret_cast<Isolate*>(isolate));
 }
 
 double Number::Value() const {
@@ -5886,12 +5955,7 @@ void V8::GetSharedMemoryStatistics(SharedMemoryStatistics* statistics) {
   i::ReadOnlyHeap::PopulateReadOnlySpaceStatistics(statistics);
 }
 
-void V8::SetIsCrossOriginIsolated() {
-  i::FLAG_harmony_sharedarraybuffer = true;
-#if V8_ENABLE_WEBASSEMBLY
-  i::FLAG_experimental_wasm_threads = true;
-#endif  // V8_ENABLE_WEBASSEMBLY
-}
+void V8::SetIsCrossOriginIsolated() {}
 
 template <typename ObjectType>
 struct InvokeBootstrapper;
@@ -6220,6 +6284,45 @@ void Context::SetContinuationPreservedEmbedderData(Local<Value> data) {
       *i::Handle<i::HeapObject>::cast(Utils::OpenHandle(*data)));
 }
 
+void v8::Context::SetPromiseHooks(Local<Function> init_hook,
+                                  Local<Function> before_hook,
+                                  Local<Function> after_hook,
+                                  Local<Function> resolve_hook) {
+  i::Handle<i::Context> context = Utils::OpenHandle(this);
+  i::Isolate* isolate = context->GetIsolate();
+
+  i::Handle<i::Object> init = isolate->factory()->undefined_value();
+  i::Handle<i::Object> before = isolate->factory()->undefined_value();
+  i::Handle<i::Object> after = isolate->factory()->undefined_value();
+  i::Handle<i::Object> resolve = isolate->factory()->undefined_value();
+
+  bool has_hook = false;
+
+  if (!init_hook.IsEmpty()) {
+    init = Utils::OpenHandle(*init_hook);
+    has_hook = true;
+  }
+  if (!before_hook.IsEmpty()) {
+    before = Utils::OpenHandle(*before_hook);
+    has_hook = true;
+  }
+  if (!after_hook.IsEmpty()) {
+    after = Utils::OpenHandle(*after_hook);
+    has_hook = true;
+  }
+  if (!resolve_hook.IsEmpty()) {
+    resolve = Utils::OpenHandle(*resolve_hook);
+    has_hook = true;
+  }
+
+  isolate->SetHasContextPromiseHooks(has_hook);
+
+  context->native_context().set_promise_hook_init_function(*init);
+  context->native_context().set_promise_hook_before_function(*before);
+  context->native_context().set_promise_hook_after_function(*after);
+  context->native_context().set_promise_hook_resolve_function(*resolve);
+}
+
 MaybeLocal<Context> metrics::Recorder::GetContext(
     Isolate* isolate, metrics::Recorder::ContextId id) {
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
@@ -6234,6 +6337,11 @@ metrics::Recorder::ContextId metrics::Recorder::GetContextId(
       handle(i_context->native_context(), isolate));
 }
 
+metrics::LongTaskStats metrics::LongTaskStats::Get(v8::Isolate* isolate) {
+  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
+  return *i_isolate->GetCurrentLongTaskStats();
+}
+
 namespace {
 i::Address* GetSerializedDataFromFixedArray(i::Isolate* isolate,
                                             i::FixedArray list, size_t index) {
@@ -6352,6 +6460,16 @@ bool FunctionTemplate::HasInstance(v8::Local<v8::Value> value) {
   return false;
 }
 
+bool FunctionTemplate::IsLeafTemplateForApiObject(
+    v8::Local<v8::Value> value) const {
+  i::DisallowGarbageCollection no_gc;
+
+  i::Object object = *Utils::OpenHandle(*value);
+
+  auto self = Utils::OpenHandle(this);
+  return self->IsLeafTemplateForApiObject(object);
+}
+
 Local<External> v8::External::New(Isolate* isolate, void* value) {
   STATIC_ASSERT(sizeof(value) == sizeof(i::Address));
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
@@ -7965,6 +8083,10 @@ v8::Local<v8::Context> Isolate::GetIncumbentContext() {
   return Utils::ToLocal(context);
 }
 
+v8::Local<Value> Isolate::ThrowError(v8::Local<v8::String> message) {
+  return ThrowException(v8::Exception::Error(message));
+}
+
 v8::Local<Value> Isolate::ThrowException(v8::Local<v8::Value> value) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
   ENTER_V8_DO_NOT_USE(isolate);
@@ -8037,6 +8159,11 @@ EmbedderHeapTracer* Isolate::GetEmbedderHeapTracer() {
   return isolate->heap()->GetEmbedderHeapTracer();
 }
 
+void Isolate::SetEmbedderRootsHandler(EmbedderRootsHandler* handler) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
+  isolate->heap()->SetEmbedderRootsHandler(handler);
+}
+
 void Isolate::AttachCppHeap(CppHeap* cpp_heap) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
   isolate->heap()->AttachCppHeap(cpp_heap);
@@ -8455,10 +8582,11 @@ bool Isolate::GetHeapSpaceStatistics(HeapSpaceStatistics* space_statistics,
     }
   } else {
     i::Space* space = heap->space(static_cast<int>(index));
-    space_statistics->space_size_ = space->CommittedMemory();
-    space_statistics->space_used_size_ = space->SizeOfObjects();
-    space_statistics->space_available_size_ = space->Available();
-    space_statistics->physical_space_size_ = space->CommittedPhysicalMemory();
+    space_statistics->space_size_ = space ? space->CommittedMemory() : 0;
+    space_statistics->space_used_size_ = space ? space->SizeOfObjects() : 0;
+    space_statistics->space_available_size_ = space ? space->Available() : 0;
+    space_statistics->physical_space_size_ =
+        space ? space->CommittedPhysicalMemory() : 0;
   }
   return true;
 }
@@ -8806,10 +8934,9 @@ void Isolate::SetStackLimit(uintptr_t stack_limit) {
 
 void Isolate::GetCodeRange(void** start, size_t* length_in_bytes) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
-  const base::AddressRegion& code_range =
-      isolate->heap()->memory_allocator()->code_range();
-  *start = reinterpret_cast<void*>(code_range.begin());
-  *length_in_bytes = code_range.size();
+  const base::AddressRegion& code_region = isolate->heap()->code_region();
+  *start = reinterpret_cast<void*>(code_region.begin());
+  *length_in_bytes = code_region.size();
 }
 
 void Isolate::GetEmbeddedCodeRange(const void** start,
@@ -8891,12 +9018,19 @@ CALLBACK_SETTER(WasmSimdEnabledCallback, WasmSimdEnabledCallback,
 CALLBACK_SETTER(WasmExceptionsEnabledCallback, WasmExceptionsEnabledCallback,
                 wasm_exceptions_enabled_callback)
 
+CALLBACK_SETTER(SharedArrayBufferConstructorEnabledCallback,
+                SharedArrayBufferConstructorEnabledCallback,
+                sharedarraybuffer_constructor_enabled_callback)
+
 void Isolate::InstallConditionalFeatures(Local<Context> context) {
-#if V8_ENABLE_WEBASSEMBLY
   v8::HandleScope handle_scope(this);
   v8::Context::Scope context_scope(context);
-  i::WasmJs::InstallConditionalFeatures(reinterpret_cast<i::Isolate*>(this),
-                                        Utils::OpenHandle(*context));
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
+  isolate->InstallConditionalFeatures(Utils::OpenHandle(*context));
+#if V8_ENABLE_WEBASSEMBLY
+  if (i::FLAG_expose_wasm) {
+    i::WasmJs::InstallConditionalFeatures(isolate, Utils::OpenHandle(*context));
+  }
 #endif  // V8_ENABLE_WEBASSEMBLY
 }
 
@@ -9379,7 +9513,21 @@ CpuProfilingOptions::CpuProfilingOptions(CpuProfilingMode mode,
                                          MaybeLocal<Context> filter_context)
     : mode_(mode),
       max_samples_(max_samples),
-      sampling_interval_us_(sampling_interval_us) {}
+      sampling_interval_us_(sampling_interval_us) {
+  if (!filter_context.IsEmpty()) {
+    Local<Context> local_filter_context = filter_context.ToLocalChecked();
+    filter_context_.Reset(local_filter_context->GetIsolate(),
+                          local_filter_context);
+    filter_context_.SetWeak();
+  }
+}
+
+void* CpuProfilingOptions::raw_filter_context() const {
+  return reinterpret_cast<void*>(
+      i::Context::cast(*Utils::OpenPersistent(filter_context_))
+          .native_context()
+          .address());
+}
 
 void CpuProfiler::Dispose() { delete reinterpret_cast<i::CpuProfiler*>(this); }
 
@@ -9660,10 +9808,11 @@ void HeapProfiler::ClearObjectIds() {
 
 const HeapSnapshot* HeapProfiler::TakeHeapSnapshot(
     ActivityControl* control, ObjectNameResolver* resolver,
-    bool treat_global_objects_as_roots) {
+    bool treat_global_objects_as_roots, bool capture_numeric_value) {
   return reinterpret_cast<const HeapSnapshot*>(
       reinterpret_cast<i::HeapProfiler*>(this)->TakeSnapshot(
-          control, resolver, treat_global_objects_as_roots));
+          control, resolver, treat_global_objects_as_roots,
+          capture_numeric_value));
 }
 
 void HeapProfiler::StartTrackingHeapObjects(bool track_allocations) {
@@ -9727,7 +9876,8 @@ void EmbedderHeapTracer::SetStackStart(void* stack_start) {
 void EmbedderHeapTracer::NotifyEmptyEmbedderStack() {
   CHECK(isolate_);
   reinterpret_cast<i::Isolate*>(isolate_)
-      ->global_handles()
+      ->heap()
+      ->local_embedder_heap_tracer()
       ->NotifyEmptyEmbedderStack();
 }
 
@@ -10026,8 +10176,7 @@ void InvokeAccessorGetterCallback(
     v8::AccessorNameGetterCallback getter) {
   // Leaving JavaScript.
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kAccessorGetterCallback);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kAccessorGetterCallback);
   Address getter_address = reinterpret_cast<Address>(getter);
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, getter_address);
@@ -10037,7 +10186,7 @@ void InvokeAccessorGetterCallback(
 void InvokeFunctionCallback(const v8::FunctionCallbackInfo<v8::Value>& info,
                             v8::FunctionCallback callback) {
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
-  RuntimeCallTimerScope timer(isolate, RuntimeCallCounterId::kFunctionCallback);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kFunctionCallback);
   Address callback_address = reinterpret_cast<Address>(callback);
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
@@ -10049,8 +10198,8 @@ void InvokeFinalizationRegistryCleanupFromTask(
     Handle<JSFinalizationRegistry> finalization_registry,
     Handle<Object> callback) {
   Isolate* isolate = finalization_registry->native_context().GetIsolate();
-  RuntimeCallTimerScope timer(
-      isolate, RuntimeCallCounterId::kFinalizationRegistryCleanupFromTask);
+  RCS_SCOPE(isolate,
+            RuntimeCallCounterId::kFinalizationRegistryCleanupFromTask);
   // Do not use ENTER_V8 because this is always called from a running
   // FinalizationRegistryCleanupTask within V8 and we should not log it as an
   // API call. This method is implemented here to avoid duplication of the
diff --git a/chromium/v8/src/ast/ast-value-factory.cc b/chromium/v8/src/ast/ast-value-factory.cc
index 6e454b22f1d..a300359a0a5 100644
--- a/chromium/v8/src/ast/ast-value-factory.cc
+++ b/chromium/v8/src/ast/ast-value-factory.cc
@@ -61,8 +61,8 @@ class OneByteStringStream {
 
 }  // namespace
 
-template <typename LocalIsolate>
-void AstRawString::Internalize(LocalIsolate* isolate) {
+template <typename IsolateT>
+void AstRawString::Internalize(IsolateT* isolate) {
   DCHECK(!has_string_);
   if (literal_bytes_.length() == 0) {
     set_string(isolate->factory()->empty_string());
@@ -185,8 +185,8 @@ int AstRawString::Compare(const AstRawString* lhs, const AstRawString* rhs) {
   return lhs->byte_length() - rhs->byte_length();
 }
 
-template <typename LocalIsolate>
-Handle<String> AstConsString::Allocate(LocalIsolate* isolate) const {
+template <typename IsolateT>
+Handle<String> AstConsString::Allocate(IsolateT* isolate) const {
   DCHECK(string_.is_null());
 
   if (IsEmpty()) {
@@ -210,8 +210,8 @@ template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
     Handle<String> AstConsString::Allocate<LocalIsolate>(
         LocalIsolate* isolate) const;
 
-template <typename LocalIsolate>
-Handle<String> AstConsString::AllocateFlat(LocalIsolate* isolate) const {
+template <typename IsolateT>
+Handle<String> AstConsString::AllocateFlat(IsolateT* isolate) const {
   if (IsEmpty()) {
     return isolate->factory()->empty_string();
   }
@@ -370,8 +370,8 @@ AstConsString* AstValueFactory::NewConsString(const AstRawString* str1,
   return NewConsString()->AddString(zone(), str1)->AddString(zone(), str2);
 }
 
-template <typename LocalIsolate>
-void AstValueFactory::Internalize(LocalIsolate* isolate) {
+template <typename IsolateT>
+void AstValueFactory::Internalize(IsolateT* isolate) {
   if (!zone_) return;
 
   // Strings need to be internalized before values, because values refer to
diff --git a/chromium/v8/src/ast/ast-value-factory.h b/chromium/v8/src/ast/ast-value-factory.h
index b66e11f99fa..290da7838f7 100644
--- a/chromium/v8/src/ast/ast-value-factory.h
+++ b/chromium/v8/src/ast/ast-value-factory.h
@@ -65,8 +65,8 @@ class AstRawString final : public ZoneObject {
   V8_EXPORT_PRIVATE bool IsOneByteEqualTo(const char* data) const;
   uint16_t FirstCharacter() const;
 
-  template <typename LocalIsolate>
-  void Internalize(LocalIsolate* isolate);
+  template <typename IsolateT>
+  void Internalize(IsolateT* isolate);
 
   // Access the physical representation:
   bool is_one_byte() const { return is_one_byte_; }
@@ -161,17 +161,17 @@ class AstConsString final : public ZoneObject {
     return segment_.string == nullptr;
   }
 
-  template <typename LocalIsolate>
-  Handle<String> GetString(LocalIsolate* isolate) {
+  template <typename IsolateT>
+  Handle<String> GetString(IsolateT* isolate) {
     if (string_.is_null()) {
       string_ = Allocate(isolate);
     }
     return string_;
   }
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-  Handle<String> AllocateFlat(LocalIsolate* isolate) const;
+  Handle<String> AllocateFlat(IsolateT* isolate) const;
 
   std::forward_list<const AstRawString*> ToRawStrings() const;
 
@@ -181,9 +181,9 @@ class AstConsString final : public ZoneObject {
 
   AstConsString() : string_(), segment_({nullptr, nullptr}) {}
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-  Handle<String> Allocate(LocalIsolate* isolate) const;
+  Handle<String> Allocate(IsolateT* isolate) const;
 
   Handle<String> string_;
 
@@ -354,8 +354,8 @@ class AstValueFactory {
   // Internalize all the strings in the factory, and prevent any more from being
   // allocated. Multiple calls to Internalize are allowed, for simplicity, where
   // subsequent calls are a no-op.
-  template <typename LocalIsolate>
-  void Internalize(LocalIsolate* isolate);
+  template <typename IsolateT>
+  void Internalize(IsolateT* isolate);
 
 #define F(name, str)                           \
   const AstRawString* name##_string() const {  \
diff --git a/chromium/v8/src/ast/ast.cc b/chromium/v8/src/ast/ast.cc
index 5515a4a3fcc..3054f99f1cd 100644
--- a/chromium/v8/src/ast/ast.cc
+++ b/chromium/v8/src/ast/ast.cc
@@ -443,8 +443,8 @@ int ObjectLiteral::InitDepthAndFlags() {
   return depth_acc;
 }
 
-template <typename LocalIsolate>
-void ObjectLiteral::BuildBoilerplateDescription(LocalIsolate* isolate) {
+template <typename IsolateT>
+void ObjectLiteral::BuildBoilerplateDescription(IsolateT* isolate) {
   if (!boilerplate_description_.is_null()) return;
 
   int index_keys = 0;
@@ -597,8 +597,8 @@ int ArrayLiteral::InitDepthAndFlags() {
   return depth_acc;
 }
 
-template <typename LocalIsolate>
-void ArrayLiteral::BuildBoilerplateDescription(LocalIsolate* isolate) {
+template <typename IsolateT>
+void ArrayLiteral::BuildBoilerplateDescription(IsolateT* isolate) {
   if (!boilerplate_description_.is_null()) return;
 
   int constants_length =
@@ -642,7 +642,7 @@ void ArrayLiteral::BuildBoilerplateDescription(LocalIsolate* isolate) {
       }
 
       // New handle scope here, needs to be after BuildContants().
-      typename LocalIsolate::HandleScopeType scope(isolate);
+      typename IsolateT::HandleScopeType scope(isolate);
 
       Object boilerplate_value = *GetBoilerplateValue(element, isolate);
       // We shouldn't allocate after creating the boilerplate value.
@@ -697,9 +697,9 @@ bool MaterializedLiteral::IsSimple() const {
   return false;
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<Object> MaterializedLiteral::GetBoilerplateValue(Expression* expression,
-                                                        LocalIsolate* isolate) {
+                                                        IsolateT* isolate) {
   if (expression->IsLiteral()) {
     return expression->AsLiteral()->BuildValue(isolate);
   }
@@ -742,8 +742,8 @@ bool MaterializedLiteral::NeedsInitialAllocationSite() {
   return false;
 }
 
-template <typename LocalIsolate>
-void MaterializedLiteral::BuildConstants(LocalIsolate* isolate) {
+template <typename IsolateT>
+void MaterializedLiteral::BuildConstants(IsolateT* isolate) {
   if (IsArrayLiteral()) {
     AsArrayLiteral()->BuildBoilerplateDescription(isolate);
     return;
@@ -760,9 +760,9 @@ template EXPORT_TEMPLATE_DEFINE(
     V8_BASE_EXPORT) void MaterializedLiteral::BuildConstants(LocalIsolate*
                                                                  isolate);
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<TemplateObjectDescription> GetTemplateObject::GetOrBuildDescription(
-    LocalIsolate* isolate) {
+    IsolateT* isolate) {
   Handle<FixedArray> raw_strings = isolate->factory()->NewFixedArray(
       this->raw_strings()->length(), AllocationType::kOld);
   bool raw_and_cooked_match = true;
@@ -978,8 +978,8 @@ bool Literal::AsArrayIndex(uint32_t* value) const {
   return ToUint32(value) && *value != kMaxUInt32;
 }
 
-template <typename LocalIsolate>
-Handle<Object> Literal::BuildValue(LocalIsolate* isolate) const {
+template <typename IsolateT>
+Handle<Object> Literal::BuildValue(IsolateT* isolate) const {
   switch (type()) {
     case kSmi:
       return handle(Smi::FromInt(smi_), isolate);
diff --git a/chromium/v8/src/ast/ast.h b/chromium/v8/src/ast/ast.h
index e11e6c458ff..e9c85920014 100644
--- a/chromium/v8/src/ast/ast.h
+++ b/chromium/v8/src/ast/ast.h
@@ -986,8 +986,8 @@ class Literal final : public Expression {
 
   // Returns an appropriate Object representing this Literal, allocating
   // a heap object if needed.
-  template <typename LocalIsolate>
-  Handle<Object> BuildValue(LocalIsolate* isolate) const;
+  template <typename IsolateT>
+  Handle<Object> BuildValue(IsolateT* isolate) const;
 
   // Support for using Literal as a HashMap key. NOTE: Currently, this works
   // only for string and number literals!
@@ -1058,17 +1058,16 @@ class MaterializedLiteral : public Expression {
   bool NeedsInitialAllocationSite();
 
   // Populate the constant properties/elements fixed array.
-  template <typename LocalIsolate>
-  void BuildConstants(LocalIsolate* isolate);
+  template <typename IsolateT>
+  void BuildConstants(IsolateT* isolate);
 
   // If the expression is a literal, return the literal value;
   // if the expression is a materialized literal and is_simple
   // then return an Array or Object Boilerplate Description
   // Otherwise, return undefined literal as the placeholder
   // in the object literal boilerplate.
-  template <typename LocalIsolate>
-  Handle<Object> GetBoilerplateValue(Expression* expression,
-                                     LocalIsolate* isolate);
+  template <typename IsolateT>
+  Handle<Object> GetBoilerplateValue(Expression* expression, IsolateT* isolate);
 };
 
 // Node for capturing a regexp literal.
@@ -1265,9 +1264,9 @@ class ObjectLiteral final : public AggregateLiteral {
   int InitDepthAndFlags();
 
   // Get the boilerplate description, populating it if necessary.
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   Handle<ObjectBoilerplateDescription> GetOrBuildBoilerplateDescription(
-      LocalIsolate* isolate) {
+      IsolateT* isolate) {
     if (boilerplate_description_.is_null()) {
       BuildBoilerplateDescription(isolate);
     }
@@ -1275,8 +1274,8 @@ class ObjectLiteral final : public AggregateLiteral {
   }
 
   // Populate the boilerplate description.
-  template <typename LocalIsolate>
-  void BuildBoilerplateDescription(LocalIsolate* isolate);
+  template <typename IsolateT>
+  void BuildBoilerplateDescription(IsolateT* isolate);
 
   // Mark all computed expressions that are bound to a key that
   // is shadowed by a later occurrence of the same key. For the
@@ -1366,9 +1365,9 @@ class ArrayLiteral final : public AggregateLiteral {
   int InitDepthAndFlags();
 
   // Get the boilerplate description, populating it if necessary.
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   Handle<ArrayBoilerplateDescription> GetOrBuildBoilerplateDescription(
-      LocalIsolate* isolate) {
+      IsolateT* isolate) {
     if (boilerplate_description_.is_null()) {
       BuildBoilerplateDescription(isolate);
     }
@@ -1376,8 +1375,8 @@ class ArrayLiteral final : public AggregateLiteral {
   }
 
   // Populate the boilerplate description.
-  template <typename LocalIsolate>
-  void BuildBoilerplateDescription(LocalIsolate* isolate);
+  template <typename IsolateT>
+  void BuildBoilerplateDescription(IsolateT* isolate);
 
   // Determines whether the {CreateShallowArrayLiteral} builtin can be used.
   bool IsFastCloningSupported() const;
@@ -2121,8 +2120,8 @@ class FunctionLiteral final : public Expression {
 
   // Empty handle means that the function does not have a shared name (i.e.
   // the name will be set dynamically after creation of the function closure).
-  template <typename LocalIsolate>
-  MaybeHandle<String> GetName(LocalIsolate* isolate) const {
+  template <typename IsolateT>
+  MaybeHandle<String> GetName(IsolateT* isolate) const {
     return raw_name_ ? raw_name_->AllocateFlat(isolate) : MaybeHandle<String>();
   }
   bool has_shared_name() const { return raw_name_ != nullptr; }
@@ -2644,9 +2643,8 @@ class GetTemplateObject final : public Expression {
     return raw_strings_;
   }
 
-  template <typename LocalIsolate>
-  Handle<TemplateObjectDescription> GetOrBuildDescription(
-      LocalIsolate* isolate);
+  template <typename IsolateT>
+  Handle<TemplateObjectDescription> GetOrBuildDescription(IsolateT* isolate);
 
  private:
   friend class AstNodeFactory;
diff --git a/chromium/v8/src/ast/modules.cc b/chromium/v8/src/ast/modules.cc
index 62dc6191414..6d1bff226d9 100644
--- a/chromium/v8/src/ast/modules.cc
+++ b/chromium/v8/src/ast/modules.cc
@@ -116,17 +116,17 @@ void SourceTextModuleDescriptor::AddStarExport(
 }
 
 namespace {
-template <typename LocalIsolate>
-Handle<PrimitiveHeapObject> ToStringOrUndefined(LocalIsolate* isolate,
+template <typename IsolateT>
+Handle<PrimitiveHeapObject> ToStringOrUndefined(IsolateT* isolate,
                                                 const AstRawString* s) {
   if (s == nullptr) return isolate->factory()->undefined_value();
   return s->string();
 }
 }  // namespace
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<ModuleRequest> SourceTextModuleDescriptor::AstModuleRequest::Serialize(
-    LocalIsolate* isolate) const {
+    IsolateT* isolate) const {
   // The import assertions will be stored in this array in the form:
   // [key1, value1, location1, key2, value2, location2, ...]
   Handle<FixedArray> import_assertions_array =
@@ -151,9 +151,9 @@ template Handle<ModuleRequest>
 SourceTextModuleDescriptor::AstModuleRequest::Serialize(
     LocalIsolate* isolate) const;
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<SourceTextModuleInfoEntry> SourceTextModuleDescriptor::Entry::Serialize(
-    LocalIsolate* isolate) const {
+    IsolateT* isolate) const {
   CHECK(Smi::IsValid(module_request));  // TODO(neis): Check earlier?
   return SourceTextModuleInfoEntry::New(
       isolate, ToStringOrUndefined(isolate, export_name),
@@ -166,9 +166,9 @@ SourceTextModuleDescriptor::Entry::Serialize(Isolate* isolate) const;
 template Handle<SourceTextModuleInfoEntry>
 SourceTextModuleDescriptor::Entry::Serialize(LocalIsolate* isolate) const;
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<FixedArray> SourceTextModuleDescriptor::SerializeRegularExports(
-    LocalIsolate* isolate, Zone* zone) const {
+    IsolateT* isolate, Zone* zone) const {
   // We serialize regular exports in a way that lets us later iterate over their
   // local names and for each local name immediately access all its export
   // names.  (Regular exports have neither import name nor module request.)
diff --git a/chromium/v8/src/ast/modules.h b/chromium/v8/src/ast/modules.h
index f776d2b5226..f496a0bb85a 100644
--- a/chromium/v8/src/ast/modules.h
+++ b/chromium/v8/src/ast/modules.h
@@ -115,8 +115,8 @@ class SourceTextModuleDescriptor : public ZoneObject {
           module_request(-1),
           cell_index(0) {}
 
-    template <typename LocalIsolate>
-    Handle<SourceTextModuleInfoEntry> Serialize(LocalIsolate* isolate) const;
+    template <typename IsolateT>
+    Handle<SourceTextModuleInfoEntry> Serialize(IsolateT* isolate) const;
   };
 
   enum CellIndexKind { kInvalid, kExport, kImport };
@@ -132,8 +132,8 @@ class SourceTextModuleDescriptor : public ZoneObject {
           position_(position),
           index_(index) {}
 
-    template <typename LocalIsolate>
-    Handle<v8::internal::ModuleRequest> Serialize(LocalIsolate* isolate) const;
+    template <typename IsolateT>
+    Handle<v8::internal::ModuleRequest> Serialize(IsolateT* isolate) const;
 
     const AstRawString* specifier() const { return specifier_; }
     const ImportAssertions* import_assertions() const {
@@ -225,8 +225,8 @@ class SourceTextModuleDescriptor : public ZoneObject {
     namespace_imports_.push_back(entry);
   }
 
-  template <typename LocalIsolate>
-  Handle<FixedArray> SerializeRegularExports(LocalIsolate* isolate,
+  template <typename IsolateT>
+  Handle<FixedArray> SerializeRegularExports(IsolateT* isolate,
                                              Zone* zone) const;
 
  private:
diff --git a/chromium/v8/src/ast/scopes.cc b/chromium/v8/src/ast/scopes.cc
index de9b25a5c59..e5b621a283a 100644
--- a/chromium/v8/src/ast/scopes.cc
+++ b/chromium/v8/src/ast/scopes.cc
@@ -623,9 +623,9 @@ void DeclarationScope::HoistSloppyBlockFunctions(AstNodeFactory* factory) {
 }
 
 bool DeclarationScope::Analyze(ParseInfo* info) {
-  RuntimeCallTimerScope runtimeTimer(
-      info->runtime_call_stats(), RuntimeCallCounterId::kCompileScopeAnalysis,
-      RuntimeCallStats::kThreadSpecific);
+  RCS_SCOPE(info->runtime_call_stats(),
+            RuntimeCallCounterId::kCompileScopeAnalysis,
+            RuntimeCallStats::kThreadSpecific);
   DCHECK_NOT_NULL(info->literal());
   DeclarationScope* scope = info->literal()->scope();
 
@@ -2532,8 +2532,8 @@ void Scope::AllocateVariablesRecursively() {
   });
 }
 
-template <typename LocalIsolate>
-void Scope::AllocateScopeInfosRecursively(LocalIsolate* isolate,
+template <typename IsolateT>
+void Scope::AllocateScopeInfosRecursively(IsolateT* isolate,
                                           MaybeHandle<ScopeInfo> outer_scope) {
   DCHECK(scope_info_.is_null());
   MaybeHandle<ScopeInfo> next_outer_scope = outer_scope;
@@ -2603,9 +2603,8 @@ void DeclarationScope::RecordNeedsPrivateNameContextChainRecalc() {
 }
 
 // static
-template <typename LocalIsolate>
-void DeclarationScope::AllocateScopeInfos(ParseInfo* info,
-                                          LocalIsolate* isolate) {
+template <typename IsolateT>
+void DeclarationScope::AllocateScopeInfos(ParseInfo* info, IsolateT* isolate) {
   DeclarationScope* scope = info->literal()->scope();
 
   // No one else should have allocated a scope info for this scope yet.
diff --git a/chromium/v8/src/ast/scopes.h b/chromium/v8/src/ast/scopes.h
index 717c797383b..2aa0c237679 100644
--- a/chromium/v8/src/ast/scopes.h
+++ b/chromium/v8/src/ast/scopes.h
@@ -716,8 +716,8 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
   V8_INLINE void AllocateNonParameterLocalsAndDeclaredGlobals();
   void AllocateVariablesRecursively();
 
-  template <typename LocalIsolate>
-  void AllocateScopeInfosRecursively(LocalIsolate* isolate,
+  template <typename IsolateT>
+  void AllocateScopeInfosRecursively(IsolateT* isolate,
                                      MaybeHandle<ScopeInfo> outer_scope);
 
   void AllocateDebuggerScopeInfos(Isolate* isolate,
@@ -1151,9 +1151,9 @@ class V8_EXPORT_PRIVATE DeclarationScope : public Scope {
 
   // Allocate ScopeInfos for top scope and any inner scopes that need them.
   // Does nothing if ScopeInfo is already allocated.
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   V8_EXPORT_PRIVATE static void AllocateScopeInfos(ParseInfo* info,
-                                                   LocalIsolate* isolate);
+                                                   IsolateT* isolate);
 
   Handle<StringSet> CollectNonLocals(Isolate* isolate,
                                      Handle<StringSet> non_locals);
diff --git a/chromium/v8/src/ast/variables.cc b/chromium/v8/src/ast/variables.cc
index da2d8387f51..4f1f46150ff 100644
--- a/chromium/v8/src/ast/variables.cc
+++ b/chromium/v8/src/ast/variables.cc
@@ -30,14 +30,15 @@ bool Variable::IsGlobalObjectProperty() const {
          scope_ != nullptr && scope_->is_script_scope();
 }
 
-bool Variable::IsReplGlobalLet() const {
-  return scope()->is_repl_mode_scope() && mode() == VariableMode::kLet;
+bool Variable::IsReplGlobal() const {
+  return scope()->is_repl_mode_scope() &&
+         (mode() == VariableMode::kLet || mode() == VariableMode::kConst);
 }
 
 void Variable::RewriteLocationForRepl() {
   DCHECK(scope_->is_repl_mode_scope());
 
-  if (mode() == VariableMode::kLet) {
+  if (mode() == VariableMode::kLet || mode() == VariableMode::kConst) {
     DCHECK_EQ(location(), VariableLocation::CONTEXT);
     bit_field_ =
         LocationField::update(bit_field_, VariableLocation::REPL_GLOBAL);
diff --git a/chromium/v8/src/ast/variables.h b/chromium/v8/src/ast/variables.h
index 7c6ee4324e8..ec31eb0689e 100644
--- a/chromium/v8/src/ast/variables.h
+++ b/chromium/v8/src/ast/variables.h
@@ -125,8 +125,9 @@ class Variable final : public ZoneObject {
   bool IsLookupSlot() const { return location() == VariableLocation::LOOKUP; }
   bool IsGlobalObjectProperty() const;
 
-  // True for 'let' variables declared in the script scope of a REPL script.
-  bool IsReplGlobalLet() const;
+  // True for 'let' and 'const' variables declared in the script scope of a REPL
+  // script.
+  bool IsReplGlobal() const;
 
   bool is_dynamic() const { return IsDynamicVariableMode(mode()); }
 
diff --git a/chromium/v8/src/base/atomicops.h b/chromium/v8/src/base/atomicops.h
index 5d6422be520..cb6940ea70a 100644
--- a/chromium/v8/src/base/atomicops.h
+++ b/chromium/v8/src/base/atomicops.h
@@ -27,6 +27,8 @@
 
 #include <stdint.h>
 
+#include <atomic>
+
 // Small C++ header which defines implementation specific macros used to
 // identify the STL implementation.
 // - libc++: captures __config for _LIBCPP_VERSION
@@ -35,6 +37,7 @@
 
 #include "src/base/base-export.h"
 #include "src/base/build_config.h"
+#include "src/base/macros.h"
 
 #if defined(V8_OS_STARBOARD)
 #include "starboard/atomic.h"
@@ -77,6 +80,21 @@ using AtomicWord = SbAtomicPtr;
 using AtomicWord = intptr_t;
 #endif
 
+namespace helper {
+template <typename T>
+volatile std::atomic<T>* to_std_atomic(volatile T* ptr) {
+  return reinterpret_cast<volatile std::atomic<T>*>(ptr);
+}
+template <typename T>
+volatile const std::atomic<T>* to_std_atomic_const(volatile const T* ptr) {
+  return reinterpret_cast<volatile const std::atomic<T>*>(ptr);
+}
+}  // namespace helper
+
+inline void SeqCst_MemoryFence() {
+  std::atomic_thread_fence(std::memory_order_seq_cst);
+}
+
 // Atomically execute:
 //   result = *ptr;
 //   if (result == old_value)
@@ -86,75 +104,225 @@ using AtomicWord = intptr_t;
 // I.e. replace |*ptr| with |new_value| if |*ptr| used to be |old_value|.
 // Always return the value of |*ptr| before the operation.
 // Acquire, Relaxed, Release correspond to standard C++ memory orders.
-Atomic8 Relaxed_CompareAndSwap(volatile Atomic8* ptr, Atomic8 old_value,
-                               Atomic8 new_value);
-Atomic16 Relaxed_CompareAndSwap(volatile Atomic16* ptr, Atomic16 old_value,
-                                Atomic16 new_value);
-Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr, Atomic32 old_value,
-                                Atomic32 new_value);
-Atomic32 AcquireRelease_CompareAndSwap(volatile Atomic32* ptr,
-                                       Atomic32 old_value, Atomic32 new_value);
-Atomic32 Relaxed_CompareAndSwap(volatile Atomic32* ptr, Atomic32 old_value,
-                                Atomic32 new_value);
-Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr, Atomic32 old_value,
-                                Atomic32 new_value);
-#ifdef V8_HOST_ARCH_64_BIT
-Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr, Atomic64 old_value,
-                                Atomic64 new_value);
-Atomic64 AcquireRelease_CompareAndSwap(volatile Atomic64* ptr,
-                                       Atomic64 old_value, Atomic64 new_value);
-Atomic64 Relaxed_CompareAndSwap(volatile Atomic64* ptr, Atomic64 old_value,
-                                Atomic64 new_value);
-Atomic64 Release_CompareAndSwap(volatile Atomic64* ptr, Atomic64 old_value,
-                                Atomic64 new_value);
-#endif  // V8_HOST_ARCH_64_BIT
-
-// Atomically store new_value into |*ptr|, returning the previous value held in
-// |*ptr|.
-Atomic32 Relaxed_AtomicExchange(volatile Atomic32* ptr, Atomic32 new_value);
-#ifdef V8_HOST_ARCH_64_BIT
-Atomic64 Relaxed_AtomicExchange(volatile Atomic64* ptr, Atomic64 new_value);
-#endif  // V8_HOST_ARCH_64_BIT
-
-// Atomically increment |*ptr| by |increment|. Returns the new value of
-// |*ptr| with the increment applied.
-Atomic32 Relaxed_AtomicIncrement(volatile Atomic32* ptr, Atomic32 increment);
-
-#ifdef V8_HOST_ARCH_64_BIT
-Atomic64 Relaxed_AtomicIncrement(volatile Atomic64* ptr, Atomic64 increment);
-#endif  // V8_HOST_ARCH_64_BIT
-
-void SeqCst_MemoryFence();
-
-void Relaxed_Store(volatile Atomic8* ptr, Atomic8 value);
-void Relaxed_Store(volatile Atomic16* ptr, Atomic16 value);
-void Relaxed_Store(volatile Atomic32* ptr, Atomic32 value);
-void Release_Store(volatile Atomic32* ptr, Atomic32 value);
-#ifdef V8_HOST_ARCH_64_BIT
-void Relaxed_Store(volatile Atomic64* ptr, Atomic64 value);
-void Release_Store(volatile Atomic64* ptr, Atomic64 value);
-#endif  // V8_HOST_ARCH_64_BIT
-
-Atomic8 Relaxed_Load(volatile const Atomic8* ptr);
-Atomic16 Relaxed_Load(volatile const Atomic16* ptr);
-Atomic32 Relaxed_Load(volatile const Atomic32* ptr);
-Atomic32 Acquire_Load(volatile const Atomic32* ptr);
-#ifdef V8_HOST_ARCH_64_BIT
-Atomic64 Relaxed_Load(volatile const Atomic64* ptr);
-Atomic64 Acquire_Load(volatile const Atomic64* ptr);
-#endif  // V8_HOST_ARCH_64_BIT
+inline Atomic8 Relaxed_CompareAndSwap(volatile Atomic8* ptr, Atomic8 old_value,
+                                      Atomic8 new_value) {
+  std::atomic_compare_exchange_strong_explicit(
+      helper::to_std_atomic(ptr), &old_value, new_value,
+      std::memory_order_relaxed, std::memory_order_relaxed);
+  return old_value;
+}
+
+inline Atomic16 Relaxed_CompareAndSwap(volatile Atomic16* ptr,
+                                       Atomic16 old_value, Atomic16 new_value) {
+  std::atomic_compare_exchange_strong_explicit(
+      helper::to_std_atomic(ptr), &old_value, new_value,
+      std::memory_order_relaxed, std::memory_order_relaxed);
+  return old_value;
+}
+
+inline Atomic32 Relaxed_CompareAndSwap(volatile Atomic32* ptr,
+                                       Atomic32 old_value, Atomic32 new_value) {
+  std::atomic_compare_exchange_strong_explicit(
+      helper::to_std_atomic(ptr), &old_value, new_value,
+      std::memory_order_relaxed, std::memory_order_relaxed);
+  return old_value;
+}
+
+inline Atomic32 Relaxed_AtomicExchange(volatile Atomic32* ptr,
+                                       Atomic32 new_value) {
+  return std::atomic_exchange_explicit(helper::to_std_atomic(ptr), new_value,
+                                       std::memory_order_relaxed);
+}
+
+inline Atomic32 Relaxed_AtomicIncrement(volatile Atomic32* ptr,
+                                        Atomic32 increment) {
+  return increment + std::atomic_fetch_add_explicit(helper::to_std_atomic(ptr),
+                                                    increment,
+                                                    std::memory_order_relaxed);
+}
+
+inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr,
+                                       Atomic32 old_value, Atomic32 new_value) {
+  atomic_compare_exchange_strong_explicit(
+      helper::to_std_atomic(ptr), &old_value, new_value,
+      std::memory_order_acquire, std::memory_order_acquire);
+  return old_value;
+}
+
+inline Atomic8 Release_CompareAndSwap(volatile Atomic8* ptr, Atomic8 old_value,
+                                      Atomic8 new_value) {
+  bool result = atomic_compare_exchange_strong_explicit(
+      helper::to_std_atomic(ptr), &old_value, new_value,
+      std::memory_order_release, std::memory_order_relaxed);
+  USE(result);  // Make gcc compiler happy.
+  return old_value;
+}
+
+inline Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr,
+                                       Atomic32 old_value, Atomic32 new_value) {
+  atomic_compare_exchange_strong_explicit(
+      helper::to_std_atomic(ptr), &old_value, new_value,
+      std::memory_order_release, std::memory_order_relaxed);
+  return old_value;
+}
+
+inline Atomic32 AcquireRelease_CompareAndSwap(volatile Atomic32* ptr,
+                                              Atomic32 old_value,
+                                              Atomic32 new_value) {
+  atomic_compare_exchange_strong_explicit(
+      helper::to_std_atomic(ptr), &old_value, new_value,
+      std::memory_order_acq_rel, std::memory_order_acquire);
+  return old_value;
+}
+
+inline void Relaxed_Store(volatile Atomic8* ptr, Atomic8 value) {
+  std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
+                             std::memory_order_relaxed);
+}
+
+inline void Relaxed_Store(volatile Atomic16* ptr, Atomic16 value) {
+  std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
+                             std::memory_order_relaxed);
+}
+
+inline void Relaxed_Store(volatile Atomic32* ptr, Atomic32 value) {
+  std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
+                             std::memory_order_relaxed);
+}
+
+inline void Release_Store(volatile Atomic8* ptr, Atomic8 value) {
+  std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
+                             std::memory_order_release);
+}
+
+inline void Release_Store(volatile Atomic32* ptr, Atomic32 value) {
+  std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
+                             std::memory_order_release);
+}
+
+inline Atomic8 Relaxed_Load(volatile const Atomic8* ptr) {
+  return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
+                                   std::memory_order_relaxed);
+}
+
+inline Atomic16 Relaxed_Load(volatile const Atomic16* ptr) {
+  return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
+                                   std::memory_order_relaxed);
+}
+
+inline Atomic32 Relaxed_Load(volatile const Atomic32* ptr) {
+  return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
+                                   std::memory_order_relaxed);
+}
+
+inline Atomic8 Acquire_Load(volatile const Atomic8* ptr) {
+  return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
+                                   std::memory_order_acquire);
+}
+
+inline Atomic32 Acquire_Load(volatile const Atomic32* ptr) {
+  return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
+                                   std::memory_order_acquire);
+}
+
+#if defined(V8_HOST_ARCH_64_BIT)
+
+inline Atomic64 Relaxed_CompareAndSwap(volatile Atomic64* ptr,
+                                       Atomic64 old_value, Atomic64 new_value) {
+  std::atomic_compare_exchange_strong_explicit(
+      helper::to_std_atomic(ptr), &old_value, new_value,
+      std::memory_order_relaxed, std::memory_order_relaxed);
+  return old_value;
+}
+
+inline Atomic64 Relaxed_AtomicExchange(volatile Atomic64* ptr,
+                                       Atomic64 new_value) {
+  return std::atomic_exchange_explicit(helper::to_std_atomic(ptr), new_value,
+                                       std::memory_order_relaxed);
+}
+
+inline Atomic64 Relaxed_AtomicIncrement(volatile Atomic64* ptr,
+                                        Atomic64 increment) {
+  return increment + std::atomic_fetch_add_explicit(helper::to_std_atomic(ptr),
+                                                    increment,
+                                                    std::memory_order_relaxed);
+}
+
+inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr,
+                                       Atomic64 old_value, Atomic64 new_value) {
+  std::atomic_compare_exchange_strong_explicit(
+      helper::to_std_atomic(ptr), &old_value, new_value,
+      std::memory_order_acquire, std::memory_order_acquire);
+  return old_value;
+}
+
+inline Atomic64 Release_CompareAndSwap(volatile Atomic64* ptr,
+                                       Atomic64 old_value, Atomic64 new_value) {
+  std::atomic_compare_exchange_strong_explicit(
+      helper::to_std_atomic(ptr), &old_value, new_value,
+      std::memory_order_release, std::memory_order_relaxed);
+  return old_value;
+}
+
+inline Atomic64 AcquireRelease_CompareAndSwap(volatile Atomic64* ptr,
+                                              Atomic64 old_value,
+                                              Atomic64 new_value) {
+  std::atomic_compare_exchange_strong_explicit(
+      helper::to_std_atomic(ptr), &old_value, new_value,
+      std::memory_order_acq_rel, std::memory_order_acquire);
+  return old_value;
+}
+
+inline void Relaxed_Store(volatile Atomic64* ptr, Atomic64 value) {
+  std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
+                             std::memory_order_relaxed);
+}
+
+inline void Release_Store(volatile Atomic64* ptr, Atomic64 value) {
+  std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
+                             std::memory_order_release);
+}
+
+inline Atomic64 Relaxed_Load(volatile const Atomic64* ptr) {
+  return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
+                                   std::memory_order_relaxed);
+}
+
+inline Atomic64 Acquire_Load(volatile const Atomic64* ptr) {
+  return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
+                                   std::memory_order_acquire);
+}
+
+#endif  // defined(V8_HOST_ARCH_64_BIT)
+
+inline void Relaxed_Memcpy(volatile Atomic8* dst, volatile const Atomic8* src,
+                           size_t bytes) {
+  constexpr size_t kAtomicWordSize = sizeof(AtomicWord);
+  while (bytes > 0 &&
+         !IsAligned(reinterpret_cast<uintptr_t>(dst), kAtomicWordSize)) {
+    Relaxed_Store(dst++, Relaxed_Load(src++));
+    --bytes;
+  }
+  if (IsAligned(reinterpret_cast<uintptr_t>(src), kAtomicWordSize) &&
+      IsAligned(reinterpret_cast<uintptr_t>(dst), kAtomicWordSize)) {
+    while (bytes >= kAtomicWordSize) {
+      Relaxed_Store(
+          reinterpret_cast<volatile AtomicWord*>(dst),
+          Relaxed_Load(reinterpret_cast<const volatile AtomicWord*>(src)));
+      dst += kAtomicWordSize;
+      src += kAtomicWordSize;
+      bytes -= kAtomicWordSize;
+    }
+  }
+  while (bytes > 0) {
+    Relaxed_Store(dst++, Relaxed_Load(src++));
+    --bytes;
+  }
+}
 
 }  // namespace base
 }  // namespace v8
 
-#if defined(V8_OS_WIN) || defined(V8_OS_STARBOARD)
-#include "src/base/atomicops_internals_std.h"
-#else
-// TODO(ulan): Switch to std version after performance regression with Wheezy
-// sysroot is no longer relevant. Debian Wheezy LTS ends on 31st of May 2018.
-#include "src/base/atomicops_internals_portable.h"
-#endif
-
 // On some platforms we need additional declarations to make
 // AtomicWord compatible with our other Atomic* types.
 #if defined(V8_OS_MACOSX) || defined(V8_OS_OPENBSD) || defined(V8_OS_AIX)
diff --git a/chromium/v8/src/base/atomicops_internals_portable.h b/chromium/v8/src/base/atomicops_internals_portable.h
deleted file mode 100644
index ac162e2a825..00000000000
--- a/chromium/v8/src/base/atomicops_internals_portable.h
+++ /dev/null
@@ -1,216 +0,0 @@
-// Copyright 2016 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// This file is an internal atomic implementation, use atomicops.h instead.
-//
-// This implementation uses C++11 atomics' member functions. The code base is
-// currently written assuming atomicity revolves around accesses instead of
-// C++11's memory locations. The burden is on the programmer to ensure that all
-// memory locations accessed atomically are never accessed non-atomically (tsan
-// should help with this).
-//
-// Of note in this implementation:
-//  * All NoBarrier variants are implemented as relaxed.
-//  * All Barrier variants are implemented as sequentially-consistent.
-//  * Compare exchange's failure ordering is always the same as the success one
-//    (except for release, which fails as relaxed): using a weaker ordering is
-//    only valid under certain uses of compare exchange.
-//  * Acquire store doesn't exist in the C11 memory model, it is instead
-//    implemented as a relaxed store followed by a sequentially consistent
-//    fence.
-//  * Release load doesn't exist in the C11 memory model, it is instead
-//    implemented as sequentially consistent fence followed by a relaxed load.
-//  * Atomic increment is expected to return the post-incremented value, whereas
-//    C11 fetch add returns the previous value. The implementation therefore
-//    needs to increment twice (which the compiler should be able to detect and
-//    optimize).
-
-#ifndef V8_BASE_ATOMICOPS_INTERNALS_PORTABLE_H_
-#define V8_BASE_ATOMICOPS_INTERNALS_PORTABLE_H_
-
-#include <atomic>
-
-#include "src/base/build_config.h"
-#include "src/base/macros.h"
-
-namespace v8 {
-namespace base {
-
-// This implementation is transitional and maintains the original API for
-// atomicops.h.
-
-inline void SeqCst_MemoryFence() {
-#if defined(__GLIBCXX__)
-  // Work around libstdc++ bug 51038 where atomic_thread_fence was declared but
-  // not defined, leading to the linker complaining about undefined references.
-  __atomic_thread_fence(std::memory_order_seq_cst);
-#else
-  std::atomic_thread_fence(std::memory_order_seq_cst);
-#endif
-}
-
-inline Atomic8 Relaxed_CompareAndSwap(volatile Atomic8* ptr, Atomic8 old_value,
-                                      Atomic8 new_value) {
-  bool result = __atomic_compare_exchange_n(ptr, &old_value, new_value, false,
-                                            __ATOMIC_RELAXED, __ATOMIC_RELAXED);
-  USE(result);  // Make gcc compiler happy.
-  return old_value;
-}
-
-inline Atomic16 Relaxed_CompareAndSwap(volatile Atomic16* ptr,
-                                       Atomic16 old_value, Atomic16 new_value) {
-  __atomic_compare_exchange_n(ptr, &old_value, new_value, false,
-                              __ATOMIC_RELAXED, __ATOMIC_RELAXED);
-  return old_value;
-}
-
-inline Atomic32 Relaxed_CompareAndSwap(volatile Atomic32* ptr,
-                                       Atomic32 old_value, Atomic32 new_value) {
-  __atomic_compare_exchange_n(ptr, &old_value, new_value, false,
-                              __ATOMIC_RELAXED, __ATOMIC_RELAXED);
-  return old_value;
-}
-
-inline Atomic32 Relaxed_AtomicExchange(volatile Atomic32* ptr,
-                                       Atomic32 new_value) {
-  return __atomic_exchange_n(ptr, new_value, __ATOMIC_RELAXED);
-}
-
-inline Atomic32 Relaxed_AtomicIncrement(volatile Atomic32* ptr,
-                                        Atomic32 increment) {
-  return increment + __atomic_fetch_add(ptr, increment, __ATOMIC_RELAXED);
-}
-
-inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr,
-                                       Atomic32 old_value, Atomic32 new_value) {
-  __atomic_compare_exchange_n(ptr, &old_value, new_value, false,
-                              __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE);
-  return old_value;
-}
-
-inline Atomic8 Release_CompareAndSwap(volatile Atomic8* ptr, Atomic8 old_value,
-                                      Atomic8 new_value) {
-  bool result = __atomic_compare_exchange_n(ptr, &old_value, new_value, false,
-                                            __ATOMIC_RELEASE, __ATOMIC_RELAXED);
-  USE(result);  // Make gcc compiler happy.
-  return old_value;
-}
-
-inline Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr,
-                                       Atomic32 old_value, Atomic32 new_value) {
-  __atomic_compare_exchange_n(ptr, &old_value, new_value, false,
-                              __ATOMIC_RELEASE, __ATOMIC_RELAXED);
-  return old_value;
-}
-
-inline Atomic32 AcquireRelease_CompareAndSwap(volatile Atomic32* ptr,
-                                              Atomic32 old_value,
-                                              Atomic32 new_value) {
-  __atomic_compare_exchange_n(ptr, &old_value, new_value, false,
-                              __ATOMIC_ACQ_REL, __ATOMIC_ACQUIRE);
-  return old_value;
-}
-
-inline void Relaxed_Store(volatile Atomic8* ptr, Atomic8 value) {
-  __atomic_store_n(ptr, value, __ATOMIC_RELAXED);
-}
-
-inline void Relaxed_Store(volatile Atomic16* ptr, Atomic16 value) {
-  __atomic_store_n(ptr, value, __ATOMIC_RELAXED);
-}
-
-inline void Relaxed_Store(volatile Atomic32* ptr, Atomic32 value) {
-  __atomic_store_n(ptr, value, __ATOMIC_RELAXED);
-}
-
-inline void Release_Store(volatile Atomic8* ptr, Atomic8 value) {
-  __atomic_store_n(ptr, value, __ATOMIC_RELEASE);
-}
-
-inline void Release_Store(volatile Atomic32* ptr, Atomic32 value) {
-  __atomic_store_n(ptr, value, __ATOMIC_RELEASE);
-}
-
-inline Atomic8 Relaxed_Load(volatile const Atomic8* ptr) {
-  return __atomic_load_n(ptr, __ATOMIC_RELAXED);
-}
-
-inline Atomic16 Relaxed_Load(volatile const Atomic16* ptr) {
-  return __atomic_load_n(ptr, __ATOMIC_RELAXED);
-}
-
-inline Atomic32 Relaxed_Load(volatile const Atomic32* ptr) {
-  return __atomic_load_n(ptr, __ATOMIC_RELAXED);
-}
-
-inline Atomic8 Acquire_Load(volatile const Atomic8* ptr) {
-  return __atomic_load_n(ptr, __ATOMIC_ACQUIRE);
-}
-
-inline Atomic32 Acquire_Load(volatile const Atomic32* ptr) {
-  return __atomic_load_n(ptr, __ATOMIC_ACQUIRE);
-}
-
-#if defined(V8_HOST_ARCH_64_BIT)
-
-inline Atomic64 Relaxed_CompareAndSwap(volatile Atomic64* ptr,
-                                       Atomic64 old_value, Atomic64 new_value) {
-  __atomic_compare_exchange_n(ptr, &old_value, new_value, false,
-                              __ATOMIC_RELAXED, __ATOMIC_RELAXED);
-  return old_value;
-}
-
-inline Atomic64 Relaxed_AtomicExchange(volatile Atomic64* ptr,
-                                       Atomic64 new_value) {
-  return __atomic_exchange_n(ptr, new_value, __ATOMIC_RELAXED);
-}
-
-inline Atomic64 Relaxed_AtomicIncrement(volatile Atomic64* ptr,
-                                        Atomic64 increment) {
-  return increment + __atomic_fetch_add(ptr, increment, __ATOMIC_RELAXED);
-}
-
-inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr,
-                                       Atomic64 old_value, Atomic64 new_value) {
-  __atomic_compare_exchange_n(ptr, &old_value, new_value, false,
-                              __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE);
-  return old_value;
-}
-
-inline Atomic64 Release_CompareAndSwap(volatile Atomic64* ptr,
-                                       Atomic64 old_value, Atomic64 new_value) {
-  __atomic_compare_exchange_n(ptr, &old_value, new_value, false,
-                              __ATOMIC_RELEASE, __ATOMIC_RELAXED);
-  return old_value;
-}
-
-inline Atomic64 AcquireRelease_CompareAndSwap(volatile Atomic64* ptr,
-                                              Atomic64 old_value,
-                                              Atomic64 new_value) {
-  __atomic_compare_exchange_n(ptr, &old_value, new_value, false,
-                              __ATOMIC_ACQ_REL, __ATOMIC_ACQUIRE);
-  return old_value;
-}
-
-inline void Relaxed_Store(volatile Atomic64* ptr, Atomic64 value) {
-  __atomic_store_n(ptr, value, __ATOMIC_RELAXED);
-}
-
-inline void Release_Store(volatile Atomic64* ptr, Atomic64 value) {
-  __atomic_store_n(ptr, value, __ATOMIC_RELEASE);
-}
-
-inline Atomic64 Relaxed_Load(volatile const Atomic64* ptr) {
-  return __atomic_load_n(ptr, __ATOMIC_RELAXED);
-}
-
-inline Atomic64 Acquire_Load(volatile const Atomic64* ptr) {
-  return __atomic_load_n(ptr, __ATOMIC_ACQUIRE);
-}
-
-#endif  // defined(V8_HOST_ARCH_64_BIT)
-}  // namespace base
-}  // namespace v8
-
-#endif  // V8_BASE_ATOMICOPS_INTERNALS_PORTABLE_H_
diff --git a/chromium/v8/src/base/atomicops_internals_std.h b/chromium/v8/src/base/atomicops_internals_std.h
deleted file mode 100644
index 1638b8b52a0..00000000000
--- a/chromium/v8/src/base/atomicops_internals_std.h
+++ /dev/null
@@ -1,224 +0,0 @@
-// Copyright 2017 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef V8_BASE_ATOMICOPS_INTERNALS_STD_H_
-#define V8_BASE_ATOMICOPS_INTERNALS_STD_H_
-
-#include <atomic>
-
-#include "src/base/build_config.h"
-#include "src/base/macros.h"
-
-namespace v8 {
-namespace base {
-
-namespace helper {
-template <typename T>
-volatile std::atomic<T>* to_std_atomic(volatile T* ptr) {
-  return reinterpret_cast<volatile std::atomic<T>*>(ptr);
-}
-template <typename T>
-volatile const std::atomic<T>* to_std_atomic_const(volatile const T* ptr) {
-  return reinterpret_cast<volatile const std::atomic<T>*>(ptr);
-}
-}  // namespace helper
-
-inline void SeqCst_MemoryFence() {
-  std::atomic_thread_fence(std::memory_order_seq_cst);
-}
-
-inline Atomic8 Relaxed_CompareAndSwap(volatile Atomic8* ptr, Atomic8 old_value,
-                                      Atomic8 new_value) {
-  std::atomic_compare_exchange_strong_explicit(
-      helper::to_std_atomic(ptr), &old_value, new_value,
-      std::memory_order_relaxed, std::memory_order_relaxed);
-  return old_value;
-}
-
-inline Atomic16 Relaxed_CompareAndSwap(volatile Atomic16* ptr,
-                                       Atomic16 old_value, Atomic16 new_value) {
-  std::atomic_compare_exchange_strong_explicit(
-      helper::to_std_atomic(ptr), &old_value, new_value,
-      std::memory_order_relaxed, std::memory_order_relaxed);
-  return old_value;
-}
-
-inline Atomic32 Relaxed_CompareAndSwap(volatile Atomic32* ptr,
-                                       Atomic32 old_value, Atomic32 new_value) {
-  std::atomic_compare_exchange_strong_explicit(
-      helper::to_std_atomic(ptr), &old_value, new_value,
-      std::memory_order_relaxed, std::memory_order_relaxed);
-  return old_value;
-}
-
-inline Atomic32 Relaxed_AtomicExchange(volatile Atomic32* ptr,
-                                       Atomic32 new_value) {
-  return std::atomic_exchange_explicit(helper::to_std_atomic(ptr), new_value,
-                                       std::memory_order_relaxed);
-}
-
-inline Atomic32 Relaxed_AtomicIncrement(volatile Atomic32* ptr,
-                                        Atomic32 increment) {
-  return increment + std::atomic_fetch_add_explicit(helper::to_std_atomic(ptr),
-                                                    increment,
-                                                    std::memory_order_relaxed);
-}
-
-inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr,
-                                       Atomic32 old_value, Atomic32 new_value) {
-  atomic_compare_exchange_strong_explicit(
-      helper::to_std_atomic(ptr), &old_value, new_value,
-      std::memory_order_acquire, std::memory_order_acquire);
-  return old_value;
-}
-
-inline Atomic8 Release_CompareAndSwap(volatile Atomic8* ptr, Atomic8 old_value,
-                                      Atomic8 new_value) {
-  bool result = atomic_compare_exchange_strong_explicit(
-      helper::to_std_atomic(ptr), &old_value, new_value,
-      std::memory_order_release, std::memory_order_relaxed);
-  USE(result);  // Make gcc compiler happy.
-  return old_value;
-}
-
-inline Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr,
-                                       Atomic32 old_value, Atomic32 new_value) {
-  atomic_compare_exchange_strong_explicit(
-      helper::to_std_atomic(ptr), &old_value, new_value,
-      std::memory_order_release, std::memory_order_relaxed);
-  return old_value;
-}
-
-inline Atomic32 AcquireRelease_CompareAndSwap(volatile Atomic32* ptr,
-                                              Atomic32 old_value,
-                                              Atomic32 new_value) {
-  atomic_compare_exchange_strong_explicit(
-      helper::to_std_atomic(ptr), &old_value, new_value,
-      std::memory_order_acq_rel, std::memory_order_acquire);
-  return old_value;
-}
-
-inline void Relaxed_Store(volatile Atomic8* ptr, Atomic8 value) {
-  std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
-                             std::memory_order_relaxed);
-}
-
-inline void Relaxed_Store(volatile Atomic16* ptr, Atomic16 value) {
-  std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
-                             std::memory_order_relaxed);
-}
-
-inline void Relaxed_Store(volatile Atomic32* ptr, Atomic32 value) {
-  std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
-                             std::memory_order_relaxed);
-}
-
-inline void Release_Store(volatile Atomic8* ptr, Atomic8 value) {
-  std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
-                             std::memory_order_release);
-}
-
-inline void Release_Store(volatile Atomic32* ptr, Atomic32 value) {
-  std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
-                             std::memory_order_release);
-}
-
-inline Atomic8 Relaxed_Load(volatile const Atomic8* ptr) {
-  return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
-                                   std::memory_order_relaxed);
-}
-
-inline Atomic16 Relaxed_Load(volatile const Atomic16* ptr) {
-  return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
-                                   std::memory_order_relaxed);
-}
-
-inline Atomic32 Relaxed_Load(volatile const Atomic32* ptr) {
-  return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
-                                   std::memory_order_relaxed);
-}
-
-inline Atomic8 Acquire_Load(volatile const Atomic8* ptr) {
-  return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
-                                   std::memory_order_acquire);
-}
-
-inline Atomic32 Acquire_Load(volatile const Atomic32* ptr) {
-  return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
-                                   std::memory_order_acquire);
-}
-
-#if defined(V8_HOST_ARCH_64_BIT)
-
-inline Atomic64 Relaxed_CompareAndSwap(volatile Atomic64* ptr,
-                                       Atomic64 old_value, Atomic64 new_value) {
-  std::atomic_compare_exchange_strong_explicit(
-      helper::to_std_atomic(ptr), &old_value, new_value,
-      std::memory_order_relaxed, std::memory_order_relaxed);
-  return old_value;
-}
-
-inline Atomic64 Relaxed_AtomicExchange(volatile Atomic64* ptr,
-                                       Atomic64 new_value) {
-  return std::atomic_exchange_explicit(helper::to_std_atomic(ptr), new_value,
-                                       std::memory_order_relaxed);
-}
-
-inline Atomic64 Relaxed_AtomicIncrement(volatile Atomic64* ptr,
-                                        Atomic64 increment) {
-  return increment + std::atomic_fetch_add_explicit(helper::to_std_atomic(ptr),
-                                                    increment,
-                                                    std::memory_order_relaxed);
-}
-
-inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr,
-                                       Atomic64 old_value, Atomic64 new_value) {
-  std::atomic_compare_exchange_strong_explicit(
-      helper::to_std_atomic(ptr), &old_value, new_value,
-      std::memory_order_acquire, std::memory_order_acquire);
-  return old_value;
-}
-
-inline Atomic64 Release_CompareAndSwap(volatile Atomic64* ptr,
-                                       Atomic64 old_value, Atomic64 new_value) {
-  std::atomic_compare_exchange_strong_explicit(
-      helper::to_std_atomic(ptr), &old_value, new_value,
-      std::memory_order_release, std::memory_order_relaxed);
-  return old_value;
-}
-
-inline Atomic64 AcquireRelease_CompareAndSwap(volatile Atomic64* ptr,
-                                              Atomic64 old_value,
-                                              Atomic64 new_value) {
-  std::atomic_compare_exchange_strong_explicit(
-      helper::to_std_atomic(ptr), &old_value, new_value,
-      std::memory_order_acq_rel, std::memory_order_acquire);
-  return old_value;
-}
-
-inline void Relaxed_Store(volatile Atomic64* ptr, Atomic64 value) {
-  std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
-                             std::memory_order_relaxed);
-}
-
-inline void Release_Store(volatile Atomic64* ptr, Atomic64 value) {
-  std::atomic_store_explicit(helper::to_std_atomic(ptr), value,
-                             std::memory_order_release);
-}
-
-inline Atomic64 Relaxed_Load(volatile const Atomic64* ptr) {
-  return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
-                                   std::memory_order_relaxed);
-}
-
-inline Atomic64 Acquire_Load(volatile const Atomic64* ptr) {
-  return std::atomic_load_explicit(helper::to_std_atomic_const(ptr),
-                                   std::memory_order_acquire);
-}
-
-#endif  // defined(V8_HOST_ARCH_64_BIT)
-}  // namespace base
-}  // namespace v8
-
-#endif  // V8_BASE_ATOMICOPS_INTERNALS_STD_H_
diff --git a/chromium/v8/src/base/bit-field.h b/chromium/v8/src/base/bit-field.h
index ca5fb459210..7b2796e3df2 100644
--- a/chromium/v8/src/base/bit-field.h
+++ b/chromium/v8/src/base/bit-field.h
@@ -52,7 +52,7 @@ class BitField final {
 
   // Returns a type U with the bit field value encoded.
   static constexpr U encode(T value) {
-    CONSTEXPR_DCHECK(is_valid(value));
+    DCHECK(is_valid(value));
     return static_cast<U>(value) << kShift;
   }
 
diff --git a/chromium/v8/src/base/bits.h b/chromium/v8/src/base/bits.h
index b137f73936a..f790dfaab47 100644
--- a/chromium/v8/src/base/bits.h
+++ b/chromium/v8/src/base/bits.h
@@ -144,7 +144,7 @@ inline constexpr
     typename std::enable_if<std::is_integral<T>::value && sizeof(T) <= 8,
                             unsigned>::type
     CountTrailingZerosNonZero(T value) {
-  CONSTEXPR_DCHECK(value != 0);
+  DCHECK_NE(0, value);
 #if V8_HAS_BUILTIN_CTZ
   return bits == 64 ? __builtin_ctzll(static_cast<uint64_t>(value))
                     : __builtin_ctz(static_cast<uint32_t>(value));
@@ -165,7 +165,7 @@ constexpr inline bool IsPowerOfTwo(T value) {
 template <typename T,
           typename = typename std::enable_if<std::is_integral<T>::value>::type>
 inline constexpr int WhichPowerOfTwo(T value) {
-  CONSTEXPR_DCHECK(IsPowerOfTwo(value));
+  DCHECK(IsPowerOfTwo(value));
 #if V8_HAS_BUILTIN_CTZ
   STATIC_ASSERT(sizeof(T) <= 8);
   return sizeof(T) == 8 ? __builtin_ctzll(static_cast<uint64_t>(value))
diff --git a/chromium/v8/src/base/bounds.h b/chromium/v8/src/base/bounds.h
index fb8c968d660..0fe141b3097 100644
--- a/chromium/v8/src/base/bounds.h
+++ b/chromium/v8/src/base/bounds.h
@@ -15,7 +15,7 @@ namespace base {
 // branch.
 template <typename T, typename U>
 inline constexpr bool IsInRange(T value, U lower_limit, U higher_limit) {
-  CONSTEXPR_DCHECK(lower_limit <= higher_limit);
+  DCHECK_LE(lower_limit, higher_limit);
   STATIC_ASSERT(sizeof(U) <= sizeof(T));
   using unsigned_T = typename std::make_unsigned<T>::type;
   // Use static_cast to support enum classes.
diff --git a/chromium/v8/src/base/cpu.cc b/chromium/v8/src/base/cpu.cc
index 17ef42a299a..9ddf8939bef 100644
--- a/chromium/v8/src/base/cpu.cc
+++ b/chromium/v8/src/base/cpu.cc
@@ -50,7 +50,7 @@
 #include "src/base/logging.h"
 #include "src/base/platform/wrappers.h"
 #if V8_OS_WIN
-#include "src/base/win32-headers.h"  // NOLINT
+#include "src/base/win32-headers.h"
 #endif
 
 namespace v8 {
diff --git a/chromium/v8/src/base/enum-set.h b/chromium/v8/src/base/enum-set.h
index f623198c2d2..ce49b3996ed 100644
--- a/chromium/v8/src/base/enum-set.h
+++ b/chromium/v8/src/base/enum-set.h
@@ -79,7 +79,7 @@ class EnumSet {
   explicit constexpr EnumSet(T bits) : bits_(bits) {}
 
   static constexpr T Mask(E element) {
-    CONSTEXPR_DCHECK(sizeof(T) * 8 > static_cast<size_t>(element));
+    DCHECK_GT(sizeof(T) * 8, static_cast<size_t>(element));
     return T{1} << static_cast<typename std::underlying_type<E>::type>(element);
   }
 
diff --git a/chromium/v8/src/base/hashmap.h b/chromium/v8/src/base/hashmap.h
index 179da5ecba6..819d589a81e 100644
--- a/chromium/v8/src/base/hashmap.h
+++ b/chromium/v8/src/base/hashmap.h
@@ -530,8 +530,8 @@ class TemplateHashMap
                                    AllocationPolicy>;
 
  public:
-  STATIC_ASSERT(sizeof(Key*) == sizeof(void*));    // NOLINT
-  STATIC_ASSERT(sizeof(Value*) == sizeof(void*));  // NOLINT
+  STATIC_ASSERT(sizeof(Key*) == sizeof(void*));
+  STATIC_ASSERT(sizeof(Value*) == sizeof(void*));
   struct value_type {
     Key* first;
     Value* second;
diff --git a/chromium/v8/src/base/logging.h b/chromium/v8/src/base/logging.h
index 2c4c536cf32..08db24a947e 100644
--- a/chromium/v8/src/base/logging.h
+++ b/chromium/v8/src/base/logging.h
@@ -134,12 +134,6 @@ V8_BASE_EXPORT void SetDcheckFunction(void (*dcheck_Function)(const char*, int,
 
 #endif
 
-#if V8_HAS_CXX14_CONSTEXPR
-#define CONSTEXPR_DCHECK(cond) DCHECK(cond)
-#else
-#define CONSTEXPR_DCHECK(cond)
-#endif
-
 namespace detail {
 template <typename... Ts>
 std::string PrintToString(Ts&&... ts) {
diff --git a/chromium/v8/src/base/once.h b/chromium/v8/src/base/once.h
index dd8b6be6213..c4224e84e35 100644
--- a/chromium/v8/src/base/once.h
+++ b/chromium/v8/src/base/once.h
@@ -53,10 +53,12 @@
 #define V8_BASE_ONCE_H_
 
 #include <stddef.h>
+
 #include <atomic>
 #include <functional>
 
 #include "src/base/base-export.h"
+#include "src/base/template-utils.h"
 
 namespace v8 {
 namespace base {
@@ -76,9 +78,9 @@ enum : uint8_t {
 
 using PointerArgFunction = void (*)(void* arg);
 
-template <typename T>
-struct OneArgFunction {
-  using type = void (*)(T);
+template <typename... Args>
+struct FunctionWithArgs {
+  using type = void (*)(Args...);
 };
 
 V8_BASE_EXPORT void CallOnceImpl(OnceType* once,
@@ -90,11 +92,13 @@ inline void CallOnce(OnceType* once, std::function<void()> init_func) {
   }
 }
 
-template <typename Arg>
+template <typename... Args, typename = std::enable_if_t<
+                                conjunction<std::is_scalar<Args>...>::value>>
 inline void CallOnce(OnceType* once,
-    typename OneArgFunction<Arg*>::type init_func, Arg* arg) {
+                     typename FunctionWithArgs<Args...>::type init_func,
+                     Args... args) {
   if (once->load(std::memory_order_acquire) != ONCE_STATE_DONE) {
-    CallOnceImpl(once, [=]() { init_func(arg); });
+    CallOnceImpl(once, [=]() { init_func(args...); });
   }
 }
 
diff --git a/chromium/v8/src/base/optional.h b/chromium/v8/src/base/optional.h
index 3c13e654c80..77e9bb896e3 100644
--- a/chromium/v8/src/base/optional.h
+++ b/chromium/v8/src/base/optional.h
@@ -558,32 +558,32 @@ class OPTIONAL_DECLSPEC_EMPTY_BASES Optional
   }
 
   constexpr const T* operator->() const {
-    CONSTEXPR_DCHECK(storage_.is_populated_);
+    DCHECK(storage_.is_populated_);
     return &storage_.value_;
   }
 
   constexpr T* operator->() {
-    CONSTEXPR_DCHECK(storage_.is_populated_);
+    DCHECK(storage_.is_populated_);
     return &storage_.value_;
   }
 
   constexpr const T& operator*() const& {
-    CONSTEXPR_DCHECK(storage_.is_populated_);
+    DCHECK(storage_.is_populated_);
     return storage_.value_;
   }
 
   constexpr T& operator*() & {
-    CONSTEXPR_DCHECK(storage_.is_populated_);
+    DCHECK(storage_.is_populated_);
     return storage_.value_;
   }
 
   constexpr const T&& operator*() const&& {
-    CONSTEXPR_DCHECK(storage_.is_populated_);
+    DCHECK(storage_.is_populated_);
     return std::move(storage_.value_);
   }
 
   constexpr T&& operator*() && {
-    CONSTEXPR_DCHECK(storage_.is_populated_);
+    DCHECK(storage_.is_populated_);
     return std::move(storage_.value_);
   }
 
diff --git a/chromium/v8/src/base/platform/mutex.h b/chromium/v8/src/base/platform/mutex.h
index 5685797f4ee..328c593a30e 100644
--- a/chromium/v8/src/base/platform/mutex.h
+++ b/chromium/v8/src/base/platform/mutex.h
@@ -14,7 +14,7 @@
 #include "src/base/logging.h"
 
 #if V8_OS_POSIX
-#include <pthread.h>  // NOLINT
+#include <pthread.h>
 #endif
 
 #if V8_OS_STARBOARD
@@ -164,6 +164,8 @@ class V8_BASE_EXPORT RecursiveMutex final {
   // successfully locked.
   bool TryLock() V8_WARN_UNUSED_RESULT;
 
+  V8_INLINE void AssertHeld() const { DCHECK_LT(0, level_); }
+
  private:
   // The implementation-defined native handle type.
 #if V8_OS_POSIX
diff --git a/chromium/v8/src/base/platform/platform-aix.cc b/chromium/v8/src/base/platform/platform-aix.cc
index 6b6a870370b..e5a5305d483 100644
--- a/chromium/v8/src/base/platform/platform-aix.cc
+++ b/chromium/v8/src/base/platform/platform-aix.cc
@@ -82,7 +82,7 @@ double AIXTimezoneCache::LocalTimeOffset(double time_ms, bool is_utc) {
 TimezoneCache* OS::CreateTimezoneCache() { return new AIXTimezoneCache(); }
 
 static unsigned StringToLong(char* buffer) {
-  return static_cast<unsigned>(strtol(buffer, nullptr, 16));  // NOLINT
+  return static_cast<unsigned>(strtol(buffer, nullptr, 16));
 }
 
 std::vector<OS::SharedLibraryAddress> OS::GetSharedLibraryAddresses() {
diff --git a/chromium/v8/src/base/platform/platform-freebsd.cc b/chromium/v8/src/base/platform/platform-freebsd.cc
index edc793c662e..ac36b0527e7 100644
--- a/chromium/v8/src/base/platform/platform-freebsd.cc
+++ b/chromium/v8/src/base/platform/platform-freebsd.cc
@@ -44,7 +44,7 @@ TimezoneCache* OS::CreateTimezoneCache() {
 }
 
 static unsigned StringToLong(char* buffer) {
-  return static_cast<unsigned>(strtol(buffer, nullptr, 16));  // NOLINT
+  return static_cast<unsigned>(strtol(buffer, nullptr, 16));
 }
 
 std::vector<OS::SharedLibraryAddress> OS::GetSharedLibraryAddresses() {
diff --git a/chromium/v8/src/base/platform/platform-posix.cc b/chromium/v8/src/base/platform/platform-posix.cc
index ee787f7d9ab..9f61a0aeb57 100644
--- a/chromium/v8/src/base/platform/platform-posix.cc
+++ b/chromium/v8/src/base/platform/platform-posix.cc
@@ -23,12 +23,12 @@
 #include <sys/types.h>
 #if defined(__APPLE__) || defined(__DragonFly__) || defined(__FreeBSD__) || \
     defined(__NetBSD__) || defined(__OpenBSD__)
-#include <sys/sysctl.h>  // NOLINT, for sysctl
+#include <sys/sysctl.h>  // for sysctl
 #endif
 
 #if defined(ANDROID) && !defined(V8_ANDROID_LOG_STDOUT)
 #define LOG_TAG "v8"
-#include <android/log.h>  // NOLINT
+#include <android/log.h>
 #endif
 
 #include <cmath>
@@ -52,7 +52,7 @@
 #endif
 
 #if V8_OS_LINUX
-#include <sys/prctl.h>  // NOLINT, for prctl
+#include <sys/prctl.h>  // for prctl
 #endif
 
 #if defined(V8_OS_FUCHSIA)
@@ -82,7 +82,7 @@ extern int madvise(caddr_t, size_t, int);
 #endif
 
 #if defined(V8_LIBC_GLIBC)
-extern "C" void* __libc_stack_end;  // NOLINT
+extern "C" void* __libc_stack_end;
 #endif
 
 namespace v8 {
@@ -936,8 +936,7 @@ static void InitializeTlsBaseOffset() {
   buffer[kBufferSize - 1] = '\0';
   char* period_pos = strchr(buffer, '.');
   *period_pos = '\0';
-  int kernel_version_major =
-      static_cast<int>(strtol(buffer, nullptr, 10));  // NOLINT
+  int kernel_version_major = static_cast<int>(strtol(buffer, nullptr, 10));
   // The constants below are taken from pthreads.s from the XNU kernel
   // sources archive at www.opensource.apple.com.
   if (kernel_version_major < 11) {
diff --git a/chromium/v8/src/base/platform/platform-win32.cc b/chromium/v8/src/base/platform/platform-win32.cc
index 50da60c72f5..9fbb2570760 100644
--- a/chromium/v8/src/base/platform/platform-win32.cc
+++ b/chromium/v8/src/base/platform/platform-win32.cc
@@ -30,7 +30,7 @@
 #include <VersionHelpers.h>
 
 #if defined(_MSC_VER)
-#include <crtdbg.h>  // NOLINT
+#include <crtdbg.h>
 #endif               // defined(_MSC_VER)
 
 // Extra functions for MinGW. Most of these are the _s functions which are in
diff --git a/chromium/v8/src/base/platform/semaphore.h b/chromium/v8/src/base/platform/semaphore.h
index 83a7a3392f7..ec107bd290e 100644
--- a/chromium/v8/src/base/platform/semaphore.h
+++ b/chromium/v8/src/base/platform/semaphore.h
@@ -12,9 +12,9 @@
 #endif
 
 #if V8_OS_MACOSX
-#include <dispatch/dispatch.h>  // NOLINT
+#include <dispatch/dispatch.h>
 #elif V8_OS_POSIX
-#include <semaphore.h>  // NOLINT
+#include <semaphore.h>
 #endif
 
 #if V8_OS_STARBOARD
diff --git a/chromium/v8/src/base/sanitizer/asan.h b/chromium/v8/src/base/sanitizer/asan.h
new file mode 100644
index 00000000000..291006d58c2
--- /dev/null
+++ b/chromium/v8/src/base/sanitizer/asan.h
@@ -0,0 +1,37 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// AddressSanitizer support.
+
+#ifndef V8_BASE_SANITIZER_ASAN_H_
+#define V8_BASE_SANITIZER_ASAN_H_
+
+#include <type_traits>
+
+#include "src/base/macros.h"
+
+#ifdef V8_USE_ADDRESS_SANITIZER
+
+#include <sanitizer/asan_interface.h>
+
+#if !defined(ASAN_POISON_MEMORY_REGION) || !defined(ASAN_UNPOISON_MEMORY_REGION)
+#error \
+    "ASAN_POISON_MEMORY_REGION and ASAN_UNPOISON_MEMORY_REGION must be defined"
+#endif
+
+#else  // !V8_USE_ADDRESS_SANITIZER
+
+#define ASAN_POISON_MEMORY_REGION(start, size)                      \
+  static_assert(std::is_pointer<decltype(start)>::value,            \
+                "static type violation");                           \
+  static_assert(std::is_convertible<decltype(size), size_t>::value, \
+                "static type violation");                           \
+  USE(start, size)
+
+#define ASAN_UNPOISON_MEMORY_REGION(start, size) \
+  ASAN_POISON_MEMORY_REGION(start, size)
+
+#endif  // !V8_USE_ADDRESS_SANITIZER
+
+#endif  // V8_BASE_SANITIZER_ASAN_H_
diff --git a/chromium/v8/src/sanitizer/lsan-page-allocator.cc b/chromium/v8/src/base/sanitizer/lsan-page-allocator.cc
index 7794e0b734e..bb52eb368fd 100644
--- a/chromium/v8/src/sanitizer/lsan-page-allocator.cc
+++ b/chromium/v8/src/base/sanitizer/lsan-page-allocator.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "src/sanitizer/lsan-page-allocator.h"
+#include "src/base/sanitizer/lsan-page-allocator.h"
 
 #include "include/v8-platform.h"
 #include "src/base/logging.h"
diff --git a/chromium/v8/src/sanitizer/lsan-page-allocator.h b/chromium/v8/src/base/sanitizer/lsan-page-allocator.h
index f86ffd98e84..4c8a1f04a0d 100644
--- a/chromium/v8/src/sanitizer/lsan-page-allocator.h
+++ b/chromium/v8/src/base/sanitizer/lsan-page-allocator.h
@@ -2,10 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef V8_SANITIZER_LSAN_PAGE_ALLOCATOR_H_
-#define V8_SANITIZER_LSAN_PAGE_ALLOCATOR_H_
+#ifndef V8_BASE_SANITIZER_LSAN_PAGE_ALLOCATOR_H_
+#define V8_BASE_SANITIZER_LSAN_PAGE_ALLOCATOR_H_
 
 #include "include/v8-platform.h"
+#include "src/base/base-export.h"
 #include "src/base/compiler-specific.h"
 
 namespace v8 {
@@ -14,7 +15,7 @@ namespace base {
 // This is a v8::PageAllocator implementation that decorates provided page
 // allocator object with leak sanitizer notifications when LEAK_SANITIZER
 // is defined.
-class LsanPageAllocator : public v8::PageAllocator {
+class V8_BASE_EXPORT LsanPageAllocator : public v8::PageAllocator {
  public:
   explicit LsanPageAllocator(v8::PageAllocator* page_allocator);
   ~LsanPageAllocator() override = default;
@@ -56,4 +57,4 @@ class LsanPageAllocator : public v8::PageAllocator {
 
 }  // namespace base
 }  // namespace v8
-#endif  // V8_SANITIZER_LSAN_PAGE_ALLOCATOR_H_
+#endif  // V8_BASE_SANITIZER_LSAN_PAGE_ALLOCATOR_H_
diff --git a/chromium/v8/src/base/lsan.h b/chromium/v8/src/base/sanitizer/lsan.h
index fd9bbd21c1b..2d7dcd7f680 100644
--- a/chromium/v8/src/base/lsan.h
+++ b/chromium/v8/src/base/sanitizer/lsan.h
@@ -4,14 +4,16 @@
 
 // LeakSanitizer support.
 
-#ifndef V8_BASE_LSAN_H_
-#define V8_BASE_LSAN_H_
+#ifndef V8_BASE_SANITIZER_LSAN_H_
+#define V8_BASE_SANITIZER_LSAN_H_
 
 #include <type_traits>
 
-// There is no compile time flag for LSan, to enable this whenever ASan is
+#include "src/base/macros.h"
+
+// There is no compile time flag for LSan, so enable this whenever ASan is
 // enabled. Note that LSan can be used as part of ASan with 'detect_leaks=1'.
-// On windows, LSan is not implemented yet, so disable it there.
+// On Windows, LSan is not implemented yet, so disable it there.
 #if defined(V8_USE_ADDRESS_SANITIZER) && !defined(V8_OS_WIN)
 
 #include <sanitizer/lsan_interface.h>
@@ -26,4 +28,4 @@
 
 #endif  // defined(V8_USE_ADDRESS_SANITIZER) && !defined(V8_OS_WIN)
 
-#endif  // V8_BASE_LSAN_H_
+#endif  // V8_BASE_SANITIZER_LSAN_H_
diff --git a/chromium/v8/src/base/sanitizer/msan.h b/chromium/v8/src/base/sanitizer/msan.h
new file mode 100644
index 00000000000..e15208efaf8
--- /dev/null
+++ b/chromium/v8/src/base/sanitizer/msan.h
@@ -0,0 +1,40 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// MemorySanitizer support.
+
+#ifndef V8_BASE_SANITIZER_MSAN_H_
+#define V8_BASE_SANITIZER_MSAN_H_
+
+#include "src/base/macros.h"
+#include "src/base/memory.h"
+
+#ifdef V8_USE_MEMORY_SANITIZER
+
+#include <sanitizer/msan_interface.h>
+
+// Marks a memory range as uninitialized, as if it was allocated here.
+#define MSAN_ALLOCATED_UNINITIALIZED_MEMORY(start, size) \
+  __msan_allocated_memory(reinterpret_cast<const void*>(start), (size))
+
+// Marks a memory range as initialized.
+#define MSAN_MEMORY_IS_INITIALIZED(start, size) \
+  __msan_unpoison(reinterpret_cast<const void*>(start), (size))
+
+#else  // !V8_USE_MEMORY_SANITIZER
+
+#define MSAN_ALLOCATED_UNINITIALIZED_MEMORY(start, size)                   \
+  static_assert((std::is_pointer<decltype(start)>::value ||                \
+                 std::is_same<v8::base::Address, decltype(start)>::value), \
+                "static type violation");                                  \
+  static_assert(std::is_convertible<decltype(size), size_t>::value,        \
+                "static type violation");                                  \
+  USE(start, size)
+
+#define MSAN_MEMORY_IS_INITIALIZED(start, size) \
+  MSAN_ALLOCATED_UNINITIALIZED_MEMORY(start, size)
+
+#endif  // V8_USE_MEMORY_SANITIZER
+
+#endif  // V8_BASE_SANITIZER_MSAN_H_
diff --git a/chromium/v8/src/base/small-vector.h b/chromium/v8/src/base/small-vector.h
index c337b9052d4..b087d44be4e 100644
--- a/chromium/v8/src/base/small-vector.h
+++ b/chromium/v8/src/base/small-vector.h
@@ -154,6 +154,13 @@ class SmallVector {
         base::bits::RoundUpToPowerOfTwo(std::max(min_capacity, 2 * capacity()));
     T* new_storage =
         reinterpret_cast<T*>(base::Malloc(sizeof(T) * new_capacity));
+    if (new_storage == nullptr) {
+      // Should be: V8::FatalProcessOutOfMemory, but we don't include V8 from
+      // base. The message is intentionally the same as FatalProcessOutOfMemory
+      // since that will help fuzzers and chromecrash to categorize such
+      // crashes appropriately.
+      FATAL("Fatal process out of memory: base::SmallVector::Grow");
+    }
     base::Memcpy(new_storage, begin_, sizeof(T) * in_use);
     if (is_big()) base::Free(begin_);
     begin_ = new_storage;
diff --git a/chromium/v8/src/base/template-utils.h b/chromium/v8/src/base/template-utils.h
index 4f082845d95..f222593e2d2 100644
--- a/chromium/v8/src/base/template-utils.h
+++ b/chromium/v8/src/base/template-utils.h
@@ -98,6 +98,15 @@ struct make_void {
 template <class... Ts>
 using void_t = typename make_void<Ts...>::type;
 
+// Corresponds to C++17's std::conjunction
+template <class...>
+struct conjunction : std::true_type {};
+template <class B>
+struct conjunction<B> : B {};
+template <class B, class... Bn>
+struct conjunction<B, Bn...>
+    : std::conditional_t<bool(B::value), conjunction<Bn...>, B> {};
+
 }  // namespace base
 }  // namespace v8
 
diff --git a/chromium/v8/src/base/v8-fallthrough.h b/chromium/v8/src/base/v8-fallthrough.h
index f61238de060..a6dc6972d6d 100644
--- a/chromium/v8/src/base/v8-fallthrough.h
+++ b/chromium/v8/src/base/v8-fallthrough.h
@@ -13,7 +13,7 @@
 // So do not include this header in any of v8's public headers -- only
 // use it in src/, not in include/.
 #if defined(__clang__)
-#define V8_FALLTHROUGH [[clang::fallthrough]]  // NOLINT(whitespace/braces)
+#define V8_FALLTHROUGH [[clang::fallthrough]]
 #else
 #define V8_FALLTHROUGH
 #endif
diff --git a/chromium/v8/src/base/vlq.h b/chromium/v8/src/base/vlq.h
index baeb5b9430d..96ee42cf6e8 100644
--- a/chromium/v8/src/base/vlq.h
+++ b/chromium/v8/src/base/vlq.h
@@ -14,60 +14,95 @@ namespace v8 {
 namespace base {
 
 static constexpr uint32_t kContinueShift = 7;
-static constexpr uint32_t kContinueMask = 1 << kContinueShift;
-static constexpr uint32_t kDataMask = kContinueMask - 1;
+static constexpr uint32_t kContinueBit = 1 << kContinueShift;
+static constexpr uint32_t kDataMask = kContinueBit - 1;
 
 // Encodes an unsigned value using variable-length encoding and stores it using
-// the passed process_byte function.
-inline void VLQEncodeUnsigned(const std::function<void(byte)>& process_byte,
-                              uint32_t value) {
-  bool has_next;
+// the passed process_byte function. The function should return a pointer to
+// the byte that was written, so that VLQEncodeUnsigned can mutate it after
+// writing it.
+template <typename Function>
+inline typename std::enable_if<
+    std::is_same<decltype(std::declval<Function>()(0)), byte*>::value,
+    void>::type
+VLQEncodeUnsigned(Function&& process_byte, uint32_t value) {
+  byte* written_byte = process_byte(value);
+  if (value <= kDataMask) {
+    // Value fits in first byte, early return.
+    return;
+  }
   do {
-    byte cur_byte = value & kDataMask;
+    // Turn on continuation bit in the byte we just wrote.
+    *written_byte |= kContinueBit;
     value >>= kContinueShift;
-    has_next = value != 0;
-    // The most significant bit is set when we are not done with the value yet.
-    cur_byte |= static_cast<uint32_t>(has_next) << kContinueShift;
-    process_byte(cur_byte);
-  } while (has_next);
+    written_byte = process_byte(value);
+  } while (value > kDataMask);
 }
 
 // Encodes value using variable-length encoding and stores it using the passed
 // process_byte function.
-inline void VLQEncode(const std::function<void(byte)>& process_byte,
-                      int32_t value) {
+template <typename Function>
+inline typename std::enable_if<
+    std::is_same<decltype(std::declval<Function>()(0)), byte*>::value,
+    void>::type
+VLQEncode(Function&& process_byte, int32_t value) {
   // This wouldn't handle kMinInt correctly if it ever encountered it.
   DCHECK_NE(value, std::numeric_limits<int32_t>::min());
   bool is_negative = value < 0;
   // Encode sign in least significant bit.
   uint32_t bits = static_cast<uint32_t>((is_negative ? -value : value) << 1) |
                   static_cast<uint32_t>(is_negative);
-  VLQEncodeUnsigned(process_byte, bits);
+  VLQEncodeUnsigned(std::forward<Function>(process_byte), bits);
 }
 
 // Wrapper of VLQEncode for std::vector backed storage containers.
 template <typename A>
 inline void VLQEncode(std::vector<byte, A>* data, int32_t value) {
-  VLQEncode([data](byte value) { data->push_back(value); }, value);
+  VLQEncode(
+      [data](byte value) {
+        data->push_back(value);
+        return &data->back();
+      },
+      value);
 }
 
 // Wrapper of VLQEncodeUnsigned for std::vector backed storage containers.
 template <typename A>
 inline void VLQEncodeUnsigned(std::vector<byte, A>* data, uint32_t value) {
-  VLQEncodeUnsigned([data](byte value) { data->push_back(value); }, value);
+  VLQEncodeUnsigned(
+      [data](byte value) {
+        data->push_back(value);
+        return &data->back();
+      },
+      value);
+}
+
+// Decodes a variable-length encoded unsigned value from bytes returned by
+// successive calls to the given function.
+template <typename GetNextFunction>
+inline typename std::enable_if<
+    std::is_same<decltype(std::declval<GetNextFunction>()()), byte>::value,
+    uint32_t>::type
+VLQDecodeUnsigned(GetNextFunction&& get_next) {
+  byte cur_byte = get_next();
+  // Single byte fast path; no need to mask.
+  if (cur_byte <= kDataMask) {
+    return cur_byte;
+  }
+  uint32_t bits = cur_byte & kDataMask;
+  for (int shift = kContinueShift; shift <= 32; shift += kContinueShift) {
+    byte cur_byte = get_next();
+    bits |= (cur_byte & kDataMask) << shift;
+    if (cur_byte <= kDataMask) break;
+  }
+  return bits;
 }
 
 // Decodes a variable-length encoded unsigned value stored in contiguous memory
 // starting at data_start + index, updating index to where the next encoded
 // value starts.
 inline uint32_t VLQDecodeUnsigned(byte* data_start, int* index) {
-  uint32_t bits = 0;
-  for (int shift = 0; true; shift += kContinueShift) {
-    byte cur_byte = data_start[(*index)++];
-    bits += (cur_byte & kDataMask) << shift;
-    if ((cur_byte & kContinueMask) == 0) break;
-  }
-  return bits;
+  return VLQDecodeUnsigned([&] { return data_start[(*index)++]; });
 }
 
 // Decodes a variable-length encoded value stored in contiguous memory starting
diff --git a/chromium/v8/src/baseline/arm/baseline-assembler-arm-inl.h b/chromium/v8/src/baseline/arm/baseline-assembler-arm-inl.h
index eca2b47cc0e..bfccef90f8f 100644
--- a/chromium/v8/src/baseline/arm/baseline-assembler-arm-inl.h
+++ b/chromium/v8/src/baseline/arm/baseline-assembler-arm-inl.h
@@ -124,7 +124,7 @@ void BaselineAssembler::CallBuiltin(Builtins::Name builtin) {
   Register temp = temps.AcquireScratch();
   __ LoadEntryFromBuiltinIndex(builtin, temp);
   __ Call(temp);
-  if (FLAG_code_comments) __ RecordComment("]");
+  __ RecordComment("]");
 }
 
 void BaselineAssembler::TailCallBuiltin(Builtins::Name builtin) {
@@ -133,7 +133,7 @@ void BaselineAssembler::TailCallBuiltin(Builtins::Name builtin) {
   Register temp = temps.AcquireScratch();
   __ LoadEntryFromBuiltinIndex(builtin, temp);
   __ Jump(temp);
-  if (FLAG_code_comments) __ RecordComment("]");
+  __ RecordComment("]");
 }
 
 void BaselineAssembler::Test(Register value, int mask) {
@@ -151,7 +151,7 @@ void BaselineAssembler::CmpInstanceType(Register map,
                                         InstanceType instance_type) {
   ScratchRegisterScope temps(this);
   Register type = temps.AcquireScratch();
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ AssertNotSmi(map);
     __ CompareObjectType(map, type, type, MAP_TYPE);
     __ Assert(eq, AbortReason::kUnexpectedValue);
@@ -198,10 +198,10 @@ void BaselineAssembler::Move(MemOperand output, Register source) {
   __ str(source, output);
 }
 void BaselineAssembler::Move(Register output, ExternalReference reference) {
-  __ mov(output, Operand(reference));
+  __ Move32BitImmediate(output, Operand(reference));
 }
 void BaselineAssembler::Move(Register output, Handle<HeapObject> value) {
-  __ mov(output, Operand(value));
+  __ Move32BitImmediate(output, Operand(value));
 }
 void BaselineAssembler::Move(Register output, int32_t value) {
   __ mov(output, Operand(value));
@@ -351,7 +351,7 @@ void BaselineAssembler::StoreTaggedFieldWithWriteBarrier(Register target,
                                                          Register value) {
   __ str(value, FieldMemOperand(target, offset));
   __ RecordWriteField(target, offset, value, kLRHasNotBeenSaved,
-                      kDontSaveFPRegs);
+                      SaveFPRegsMode::kIgnore);
 }
 void BaselineAssembler::StoreTaggedFieldNoWriteBarrier(Register target,
                                                        int offset,
diff --git a/chromium/v8/src/baseline/arm/baseline-compiler-arm-inl.h b/chromium/v8/src/baseline/arm/baseline-compiler-arm-inl.h
index ff2b6d1a831..d7f0a606d3b 100644
--- a/chromium/v8/src/baseline/arm/baseline-compiler-arm-inl.h
+++ b/chromium/v8/src/baseline/arm/baseline-compiler-arm-inl.h
@@ -19,9 +19,9 @@ void BaselineCompiler::Prologue() {
   __ masm()->EnterFrame(StackFrame::BASELINE);
   DCHECK_EQ(kJSFunctionRegister, kJavaScriptCallTargetRegister);
   int max_frame_size = bytecode_->frame_size() + max_call_args_;
-  CallBuiltin(Builtins::kBaselineOutOfLinePrologue, kContextRegister,
-              kJSFunctionRegister, kJavaScriptCallArgCountRegister,
-              max_frame_size, kJavaScriptCallNewTargetRegister, bytecode_);
+  CallBuiltin<Builtins::kBaselineOutOfLinePrologue>(
+      kContextRegister, kJSFunctionRegister, kJavaScriptCallArgCountRegister,
+      max_frame_size, kJavaScriptCallNewTargetRegister, bytecode_);
 
   PrologueFillFrame();
 }
diff --git a/chromium/v8/src/baseline/arm64/baseline-assembler-arm64-inl.h b/chromium/v8/src/baseline/arm64/baseline-assembler-arm64-inl.h
index 27b7c2b2d8d..63e90df4d62 100644
--- a/chromium/v8/src/baseline/arm64/baseline-assembler-arm64-inl.h
+++ b/chromium/v8/src/baseline/arm64/baseline-assembler-arm64-inl.h
@@ -167,7 +167,7 @@ void BaselineAssembler::CmpInstanceType(Register map,
                                         InstanceType instance_type) {
   ScratchRegisterScope temps(this);
   Register type = temps.AcquireScratch();
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ AssertNotSmi(map);
     __ CompareObjectType(map, type, type, MAP_TYPE);
     __ Assert(eq, AbortReason::kUnexpectedValue);
@@ -422,7 +422,7 @@ void BaselineAssembler::StoreTaggedFieldWithWriteBarrier(Register target,
                                                          Register value) {
   __ StoreTaggedField(value, FieldMemOperand(target, offset));
   __ RecordWriteField(target, offset, value, kLRHasNotBeenSaved,
-                      kDontSaveFPRegs);
+                      SaveFPRegsMode::kIgnore);
 }
 void BaselineAssembler::StoreTaggedFieldNoWriteBarrier(Register target,
                                                        int offset,
diff --git a/chromium/v8/src/baseline/arm64/baseline-compiler-arm64-inl.h b/chromium/v8/src/baseline/arm64/baseline-compiler-arm64-inl.h
index e567be41d24..0807c5434ac 100644
--- a/chromium/v8/src/baseline/arm64/baseline-compiler-arm64-inl.h
+++ b/chromium/v8/src/baseline/arm64/baseline-compiler-arm64-inl.h
@@ -18,9 +18,9 @@ void BaselineCompiler::Prologue() {
   __ masm()->EnterFrame(StackFrame::BASELINE);
   DCHECK_EQ(kJSFunctionRegister, kJavaScriptCallTargetRegister);
   int max_frame_size = bytecode_->frame_size() + max_call_args_;
-  CallBuiltin(Builtins::kBaselineOutOfLinePrologue, kContextRegister,
-              kJSFunctionRegister, kJavaScriptCallArgCountRegister,
-              max_frame_size, kJavaScriptCallNewTargetRegister, bytecode_);
+  CallBuiltin<Builtins::kBaselineOutOfLinePrologue>(
+      kContextRegister, kJSFunctionRegister, kJavaScriptCallArgCountRegister,
+      max_frame_size, kJavaScriptCallNewTargetRegister, bytecode_);
 
   __ masm()->AssertSpAligned();
   PrologueFillFrame();
diff --git a/chromium/v8/src/baseline/baseline-assembler-inl.h b/chromium/v8/src/baseline/baseline-assembler-inl.h
index 8fd54d63a2f..401062517f6 100644
--- a/chromium/v8/src/baseline/baseline-assembler-inl.h
+++ b/chromium/v8/src/baseline/baseline-assembler-inl.h
@@ -8,12 +8,13 @@
 // TODO(v8:11421): Remove #if once baseline compiler is ported to other
 // architectures.
 #if V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || \
-    V8_TARGET_ARCH_ARM
+    V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_RISCV64
 
 #include <type_traits>
 #include <unordered_map>
 
 #include "src/baseline/baseline-assembler.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/interpreter/bytecode-register.h"
 #include "src/objects/feedback-cell.h"
 #include "src/objects/js-function.h"
@@ -27,6 +28,8 @@
 #include "src/baseline/ia32/baseline-assembler-ia32-inl.h"
 #elif V8_TARGET_ARCH_ARM
 #include "src/baseline/arm/baseline-assembler-arm-inl.h"
+#elif V8_TARGET_ARCH_RISCV64
+#include "src/baseline/riscv64/baseline-assembler-riscv64-inl.h"
 #else
 #error Unsupported target architecture.
 #endif
@@ -41,10 +44,10 @@ void BaselineAssembler::GetCode(Isolate* isolate, CodeDesc* desc) {
   __ GetCode(isolate, desc);
 }
 int BaselineAssembler::pc_offset() const { return __ pc_offset(); }
-bool BaselineAssembler::emit_debug_code() const { return __ emit_debug_code(); }
 void BaselineAssembler::CodeEntry() const { __ CodeEntry(); }
 void BaselineAssembler::ExceptionHandler() const { __ ExceptionHandler(); }
 void BaselineAssembler::RecordComment(const char* string) {
+  if (!FLAG_code_comments) return;
   __ RecordComment(string);
 }
 void BaselineAssembler::Trap() { __ Trap(); }
diff --git a/chromium/v8/src/baseline/baseline-assembler.h b/chromium/v8/src/baseline/baseline-assembler.h
index 38874d556f0..7c46cd5e2c4 100644
--- a/chromium/v8/src/baseline/baseline-assembler.h
+++ b/chromium/v8/src/baseline/baseline-assembler.h
@@ -8,7 +8,7 @@
 // TODO(v8:11421): Remove #if once baseline compiler is ported to other
 // architectures.
 #if V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || \
-    V8_TARGET_ARCH_ARM
+    V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_RISCV64
 
 #include "src/codegen/macro-assembler.h"
 #include "src/objects/tagged-index.h"
@@ -32,10 +32,9 @@ class BaselineAssembler {
 
   inline void GetCode(Isolate* isolate, CodeDesc* desc);
   inline int pc_offset() const;
-  inline bool emit_debug_code() const;
   inline void CodeEntry() const;
   inline void ExceptionHandler() const;
-  inline void RecordComment(const char* string);
+  V8_INLINE void RecordComment(const char* string);
   inline void Trap();
   inline void DebugBreak();
 
diff --git a/chromium/v8/src/baseline/baseline-compiler.cc b/chromium/v8/src/baseline/baseline-compiler.cc
index 3d599c11fd5..9c6e3f10e6d 100644
--- a/chromium/v8/src/baseline/baseline-compiler.cc
+++ b/chromium/v8/src/baseline/baseline-compiler.cc
@@ -4,8 +4,9 @@
 
 // TODO(v8:11421): Remove #if once baseline compiler is ported to other
 // architectures.
+#include "src/base/bits.h"
 #if V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || \
-    V8_TARGET_ARCH_ARM
+    V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_RISCV64
 
 #include "src/baseline/baseline-compiler.h"
 
@@ -19,7 +20,7 @@
 #include "src/builtins/builtins.h"
 #include "src/codegen/assembler.h"
 #include "src/codegen/compiler.h"
-#include "src/codegen/interface-descriptors.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/machine-type.h"
 #include "src/codegen/macro-assembler-inl.h"
 #include "src/common/globals.h"
@@ -40,6 +41,8 @@
 #include "src/baseline/ia32/baseline-compiler-ia32-inl.h"
 #elif V8_TARGET_ARCH_ARM
 #include "src/baseline/arm/baseline-compiler-arm-inl.h"
+#elif V8_TARGET_ARCH_RISCV64
+#include "src/baseline/riscv64/baseline-compiler-riscv64-inl.h"
 #else
 #error Unsupported target architecture.
 #endif
@@ -48,9 +51,9 @@ namespace v8 {
 namespace internal {
 namespace baseline {
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<ByteArray> BytecodeOffsetTableBuilder::ToBytecodeOffsetTable(
-    LocalIsolate* isolate) {
+    IsolateT* isolate) {
   if (bytes_.empty()) return isolate->factory()->empty_byte_array();
   Handle<ByteArray> table = isolate->factory()->NewByteArray(
       static_cast<int>(bytes_.size()), AllocationType::kOld);
@@ -68,6 +71,7 @@ bool Clobbers(Register target, TaggedIndex index) { return false; }
 bool Clobbers(Register target, int32_t imm) { return false; }
 bool Clobbers(Register target, RootIndex index) { return false; }
 bool Clobbers(Register target, interpreter::Register reg) { return false; }
+bool Clobbers(Register target, interpreter::RegisterList list) { return false; }
 
 // We don't know what's inside machine registers or operands, so assume they
 // match.
@@ -97,134 +101,151 @@ bool MachineTypeMatches(MachineType type, interpreter::Register reg) {
   return type.IsTagged();
 }
 
-template <typename... Args>
+template <typename Descriptor, typename... Args>
 struct CheckArgsHelper;
 
-template <>
-struct CheckArgsHelper<> {
-  static void Check(BaselineAssembler* masm, CallInterfaceDescriptor descriptor,
-                    int i) {
-    if (descriptor.AllowVarArgs()) {
-      CHECK_GE(i, descriptor.GetParameterCount());
+template <typename Descriptor>
+struct CheckArgsHelper<Descriptor> {
+  static void Check(BaselineAssembler* masm, int i) {
+    if (Descriptor::AllowVarArgs()) {
+      CHECK_GE(i, Descriptor::GetParameterCount());
     } else {
-      CHECK_EQ(i, descriptor.GetParameterCount());
+      CHECK_EQ(i, Descriptor::GetParameterCount());
     }
   }
 };
 
-template <typename Arg, typename... Args>
-struct CheckArgsHelper<Arg, Args...> {
-  static void Check(BaselineAssembler* masm, CallInterfaceDescriptor descriptor,
-                    int i, Arg arg, Args... args) {
-    if (i >= descriptor.GetParameterCount()) {
-      CHECK(descriptor.AllowVarArgs());
+template <typename Descriptor, typename Arg, typename... Args>
+struct CheckArgsHelper<Descriptor, Arg, Args...> {
+  static void Check(BaselineAssembler* masm, int i, Arg arg, Args... args) {
+    if (i >= Descriptor::GetParameterCount()) {
+      CHECK(Descriptor::AllowVarArgs());
       return;
     }
-    CHECK(MachineTypeMatches(descriptor.GetParameterType(i), arg));
-    CheckArgsHelper<Args...>::Check(masm, descriptor, i + 1, args...);
+    CHECK(MachineTypeMatches(Descriptor().GetParameterType(i), arg));
+    CheckArgsHelper<Descriptor, Args...>::Check(masm, i + 1, args...);
   }
 };
 
-template <typename... Args>
-struct CheckArgsHelper<interpreter::RegisterList, Args...> {
-  static void Check(BaselineAssembler* masm, CallInterfaceDescriptor descriptor,
-                    int i, interpreter::RegisterList list, Args... args) {
+template <typename Descriptor, typename... Args>
+struct CheckArgsHelper<Descriptor, interpreter::RegisterList, Args...> {
+  static void Check(BaselineAssembler* masm, int i,
+                    interpreter::RegisterList list, Args... args) {
     for (int reg_index = 0; reg_index < list.register_count();
          ++reg_index, ++i) {
-      if (i >= descriptor.GetParameterCount()) {
-        CHECK(descriptor.AllowVarArgs());
+      if (i >= Descriptor::GetParameterCount()) {
+        CHECK(Descriptor::AllowVarArgs());
         return;
       }
-      CHECK(
-          MachineTypeMatches(descriptor.GetParameterType(i), list[reg_index]));
+      CHECK(MachineTypeMatches(Descriptor().GetParameterType(i),
+                               list[reg_index]));
     }
-    CheckArgsHelper<Args...>::Check(masm, descriptor, i, args...);
+    CheckArgsHelper<Descriptor, Args...>::Check(masm, i, args...);
   }
 };
 
-template <typename... Args>
-void CheckArgs(BaselineAssembler* masm, CallInterfaceDescriptor descriptor,
-               Args... args) {
-  CheckArgsHelper<Args...>::Check(masm, descriptor, 0, args...);
+template <typename Descriptor, typename... Args>
+void CheckArgs(BaselineAssembler* masm, Args... args) {
+  CheckArgsHelper<Descriptor, Args...>::Check(masm, 0, args...);
+}
+
+void CheckSettingDoesntClobber(Register target) {}
+template <typename Arg, typename... Args>
+void CheckSettingDoesntClobber(Register target, Arg arg, Args... args) {
+  DCHECK(!Clobbers(target, arg));
+  CheckSettingDoesntClobber(target, args...);
 }
 
 #else  // DEBUG
 
-template <typename... Args>
+template <typename Descriptor, typename... Args>
 void CheckArgs(Args... args) {}
 
+template <typename... Args>
+void CheckSettingDoesntClobber(Register target, Args... args) {}
+
 #endif  // DEBUG
 
-template <typename... Args>
+template <typename Descriptor, int ArgIndex, bool kIsRegister, typename... Args>
 struct ArgumentSettingHelper;
 
-template <>
-struct ArgumentSettingHelper<> {
-  static void Set(BaselineAssembler* masm, CallInterfaceDescriptor descriptor,
-                  int i) {}
-  static void CheckSettingDoesntClobber(Register target, int arg_index) {}
+template <typename Descriptor, int ArgIndex, bool kIsRegister>
+struct ArgumentSettingHelper<Descriptor, ArgIndex, kIsRegister> {
+  static void Set(BaselineAssembler* masm) {
+    // Should only ever be called for the end of register arguments.
+    STATIC_ASSERT(ArgIndex == Descriptor::GetRegisterParameterCount());
+  }
 };
 
-template <typename Arg, typename... Args>
-struct ArgumentSettingHelper<Arg, Args...> {
-  static void Set(BaselineAssembler* masm, CallInterfaceDescriptor descriptor,
-                  int i, Arg arg, Args... args) {
-    if (i < descriptor.GetRegisterParameterCount()) {
-      Register target = descriptor.GetRegisterParameter(i);
-      ArgumentSettingHelper<Args...>::CheckSettingDoesntClobber(target, i + 1,
-                                                                args...);
-      masm->Move(target, arg);
-      ArgumentSettingHelper<Args...>::Set(masm, descriptor, i + 1, args...);
-    } else if (descriptor.GetStackArgumentOrder() ==
-               StackArgumentOrder::kDefault) {
-      masm->Push(arg, args...);
-    } else {
-      masm->PushReverse(arg, args...);
-    }
+template <typename Descriptor, int ArgIndex, typename Arg, typename... Args>
+struct ArgumentSettingHelper<Descriptor, ArgIndex, true, Arg, Args...> {
+  static void Set(BaselineAssembler* masm, Arg arg, Args... args) {
+    STATIC_ASSERT(ArgIndex < Descriptor::GetRegisterParameterCount());
+    Register target = Descriptor::GetRegisterParameter(ArgIndex);
+    CheckSettingDoesntClobber(target, args...);
+    masm->Move(target, arg);
+    ArgumentSettingHelper<Descriptor, ArgIndex + 1,
+                          (ArgIndex + 1 <
+                           Descriptor::GetRegisterParameterCount()),
+                          Args...>::Set(masm, args...);
   }
-  static void CheckSettingDoesntClobber(Register target, int arg_index, Arg arg,
-                                        Args... args) {
-    DCHECK(!Clobbers(target, arg));
-    ArgumentSettingHelper<Args...>::CheckSettingDoesntClobber(
-        target, arg_index + 1, args...);
+};
+
+template <typename Descriptor, int ArgIndex>
+struct ArgumentSettingHelper<Descriptor, ArgIndex, true,
+                             interpreter::RegisterList> {
+  static void Set(BaselineAssembler* masm, interpreter::RegisterList list) {
+    STATIC_ASSERT(ArgIndex < Descriptor::GetRegisterParameterCount());
+    DCHECK_EQ(ArgIndex + list.register_count(),
+              Descriptor::GetRegisterParameterCount());
+    for (int i = 0; ArgIndex + i < Descriptor::GetRegisterParameterCount();
+         ++i) {
+      Register target = Descriptor::GetRegisterParameter(ArgIndex + i);
+      masm->Move(target, masm->RegisterFrameOperand(list[i]));
+    }
   }
 };
 
-// Specialization for interpreter::RegisterList which iterates it.
-// RegisterLists are only allowed to be the last argument.
-template <>
-struct ArgumentSettingHelper<interpreter::RegisterList> {
-  static void Set(BaselineAssembler* masm, CallInterfaceDescriptor descriptor,
-                  int i, interpreter::RegisterList list) {
-    // Either all the values are in machine registers, or they're all on the
-    // stack.
-    if (i < descriptor.GetRegisterParameterCount()) {
-      for (int reg_index = 0; reg_index < list.register_count();
-           ++reg_index, ++i) {
-        Register target = descriptor.GetRegisterParameter(i);
-        masm->Move(target, masm->RegisterFrameOperand(list[reg_index]));
-      }
-    } else if (descriptor.GetStackArgumentOrder() ==
-               StackArgumentOrder::kDefault) {
-      masm->Push(list);
+template <typename Descriptor, int ArgIndex, typename Arg, typename... Args>
+struct ArgumentSettingHelper<Descriptor, ArgIndex, false, Arg, Args...> {
+  static void Set(BaselineAssembler* masm, Arg arg, Args... args) {
+    if (Descriptor::kStackArgumentOrder == StackArgumentOrder::kDefault) {
+      masm->Push(arg, args...);
     } else {
-      masm->PushReverse(list);
+      masm->PushReverse(arg, args...);
     }
   }
-  static void CheckSettingDoesntClobber(Register target, int arg_index,
-                                        interpreter::RegisterList arg) {}
 };
 
-template <typename... Args>
-void MoveArgumentsForDescriptor(BaselineAssembler* masm,
-                                CallInterfaceDescriptor descriptor,
-                                Args... args) {
-  CheckArgs(masm, descriptor, args...);
-  ArgumentSettingHelper<Args...>::Set(masm, descriptor, 0, args...);
+template <Builtins::Name kBuiltin, typename... Args>
+void MoveArgumentsForBuiltin(BaselineAssembler* masm, Args... args) {
+  using Descriptor = typename CallInterfaceDescriptorFor<kBuiltin>::type;
+  CheckArgs<Descriptor>(masm, args...);
+  ArgumentSettingHelper<Descriptor, 0,
+                        (0 < Descriptor::GetRegisterParameterCount()),
+                        Args...>::Set(masm, args...);
+  if (Descriptor::HasContextParameter()) {
+    masm->LoadContext(Descriptor::ContextRegister());
+  }
 }
 
 }  // namespace detail
 
+namespace {
+// Rough upper-bound estimate. Copying the data is most likely more expensive
+// than pre-allocating a large enough buffer.
+#ifdef V8_TARGET_ARCH_IA32
+const int kAverageBytecodeToInstructionRatio = 5;
+#else
+const int kAverageBytecodeToInstructionRatio = 7;
+#endif
+std::unique_ptr<AssemblerBuffer> AllocateBuffer(
+    Handle<BytecodeArray> bytecodes) {
+  int estimated_size = bytecodes->length() * kAverageBytecodeToInstructionRatio;
+  return NewAssemblerBuffer(RoundUp(estimated_size, 4 * KB));
+}
+}  // namespace
+
 BaselineCompiler::BaselineCompiler(
     Isolate* isolate, Handle<SharedFunctionInfo> shared_function_info,
     Handle<BytecodeArray> bytecode)
@@ -232,20 +253,26 @@ BaselineCompiler::BaselineCompiler(
       stats_(isolate->counters()->runtime_call_stats()),
       shared_function_info_(shared_function_info),
       bytecode_(bytecode),
-      masm_(isolate, CodeObjectRequired::kNo),
+      masm_(isolate, CodeObjectRequired::kNo, AllocateBuffer(bytecode)),
       basm_(&masm_),
       iterator_(bytecode_),
       zone_(isolate->allocator(), ZONE_NAME),
       labels_(zone_.NewArray<BaselineLabels*>(bytecode_->length())) {
   MemsetPointer(labels_, nullptr, bytecode_->length());
+
+  // Empirically determined expected size of the offset table at the 95th %ile,
+  // based on the size of the bytecode, to be:
+  //
+  //   16 + (bytecode size) / 4
+  bytecode_offset_table_builder_.Reserve(
+      base::bits::RoundUpToPowerOfTwo(16 + bytecode_->Size() / 4));
 }
 
 #define __ basm_.
 
 void BaselineCompiler::GenerateCode() {
   {
-    RuntimeCallTimerScope runtimeTimer(
-        stats_, RuntimeCallCounterId::kCompileBaselinePreVisit);
+    RCS_SCOPE(stats_, RuntimeCallCounterId::kCompileBaselinePreVisit);
     for (; !iterator_.done(); iterator_.Advance()) {
       PreVisitSingleBytecode();
     }
@@ -257,8 +284,7 @@ void BaselineCompiler::GenerateCode() {
   __ CodeEntry();
 
   {
-    RuntimeCallTimerScope runtimeTimer(
-        stats_, RuntimeCallCounterId::kCompileBaselineVisit);
+    RCS_SCOPE(stats_, RuntimeCallCounterId::kCompileBaselineVisit);
     Prologue();
     AddPosition();
     for (; !iterator_.done(); iterator_.Advance()) {
@@ -453,7 +479,7 @@ void BaselineCompiler::VisitSingleBytecode() {
 }
 
 void BaselineCompiler::VerifyFrame() {
-  if (__ emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ RecordComment("[ Verify frame");
     __ RecordComment(" -- Verify frame size");
     VerifyFrameSize();
@@ -552,28 +578,18 @@ Label* BaselineCompiler::BuildForwardJumpLabel() {
   return &threaded_label->label;
 }
 
-template <typename... Args>
-void BaselineCompiler::CallBuiltin(Builtins::Name builtin, Args... args) {
+template <Builtins::Name kBuiltin, typename... Args>
+void BaselineCompiler::CallBuiltin(Args... args) {
   __ RecordComment("[ CallBuiltin");
-  CallInterfaceDescriptor descriptor =
-      Builtins::CallInterfaceDescriptorFor(builtin);
-  detail::MoveArgumentsForDescriptor(&basm_, descriptor, args...);
-  if (descriptor.HasContextParameter()) {
-    __ LoadContext(descriptor.ContextRegister());
-  }
-  __ CallBuiltin(builtin);
+  detail::MoveArgumentsForBuiltin<kBuiltin>(&basm_, args...);
+  __ CallBuiltin(kBuiltin);
   __ RecordComment("]");
 }
 
-template <typename... Args>
-void BaselineCompiler::TailCallBuiltin(Builtins::Name builtin, Args... args) {
-  CallInterfaceDescriptor descriptor =
-      Builtins::CallInterfaceDescriptorFor(builtin);
-  detail::MoveArgumentsForDescriptor(&basm_, descriptor, args...);
-  if (descriptor.HasContextParameter()) {
-    __ LoadContext(descriptor.ContextRegister());
-  }
-  __ TailCallBuiltin(builtin);
+template <Builtins::Name kBuiltin, typename... Args>
+void BaselineCompiler::TailCallBuiltin(Args... args) {
+  detail::MoveArgumentsForBuiltin<kBuiltin>(&basm_, args...);
+  __ TailCallBuiltin(kBuiltin);
 }
 
 template <typename... Args>
@@ -584,27 +600,17 @@ void BaselineCompiler::CallRuntime(Runtime::FunctionId function, Args... args) {
 }
 
 // Returns into kInterpreterAccumulatorRegister
-void BaselineCompiler::JumpIfToBoolean(bool do_jump_if_true, Register reg,
-                                       Label* label, Label::Distance distance) {
-  Label end;
-  Label::Distance end_distance = Label::kNear;
-
-  Label* true_label = do_jump_if_true ? label : &end;
-  Label::Distance true_distance = do_jump_if_true ? distance : end_distance;
-  Label* false_label = do_jump_if_true ? &end : label;
-  Label::Distance false_distance = do_jump_if_true ? end_distance : distance;
-
-  BaselineAssembler::ScratchRegisterScope scratch_scope(&basm_);
-  Register to_boolean = scratch_scope.AcquireScratch();
-  {
-    SaveAccumulatorScope accumulator_scope(&basm_);
-    CallBuiltin(Builtins::kToBoolean, reg);
-    __ Move(to_boolean, kInterpreterAccumulatorRegister);
-  }
-  __ JumpIfRoot(to_boolean, RootIndex::kTrueValue, true_label, true_distance);
-  if (false_label != &end) __ Jump(false_label, false_distance);
-
-  __ Bind(&end);
+void BaselineCompiler::JumpIfToBoolean(bool do_jump_if_true, Label* label,
+                                       Label::Distance distance) {
+  CallBuiltin<Builtins::kToBooleanForBaselineJump>(
+      kInterpreterAccumulatorRegister);
+  // ToBooleanForBaselineJump returns the ToBoolean value into return reg 1, and
+  // the original value into kInterpreterAccumulatorRegister, so we don't have
+  // to worry about it getting clobbered.
+  STATIC_ASSERT(kReturnRegister0 == kInterpreterAccumulatorRegister);
+  __ Cmp(kReturnRegister1, Smi::FromInt(0));
+  __ JumpIf(do_jump_if_true ? Condition::kNotEqual : Condition::kEqual, label,
+            distance);
 }
 
 void BaselineCompiler::VisitLdaZero() {
@@ -641,22 +647,21 @@ void BaselineCompiler::VisitLdaConstant() {
 }
 
 void BaselineCompiler::VisitLdaGlobal() {
-  CallBuiltin(Builtins::kLoadGlobalICBaseline,
-              Constant<Name>(0),  // name
-              IndexAsTagged(1));  // slot
+  CallBuiltin<Builtins::kLoadGlobalICBaseline>(Constant<Name>(0),  // name
+                                               IndexAsTagged(1));  // slot
 }
 
 void BaselineCompiler::VisitLdaGlobalInsideTypeof() {
-  CallBuiltin(Builtins::kLoadGlobalICInsideTypeofBaseline,
-              Constant<Name>(0),  // name
-              IndexAsTagged(1));  // slot
+  CallBuiltin<Builtins::kLoadGlobalICInsideTypeofBaseline>(
+      Constant<Name>(0),  // name
+      IndexAsTagged(1));  // slot
 }
 
 void BaselineCompiler::VisitStaGlobal() {
-  CallBuiltin(Builtins::kStoreGlobalICBaseline,
-              Constant<Name>(0),                // name
-              kInterpreterAccumulatorRegister,  // value
-              IndexAsTagged(1));                // slot
+  CallBuiltin<Builtins::kStoreGlobalICBaseline>(
+      Constant<Name>(0),                // name
+      kInterpreterAccumulatorRegister,  // value
+      IndexAsTagged(1));                // slot
 }
 
 void BaselineCompiler::VisitPushContext() {
@@ -730,13 +735,13 @@ void BaselineCompiler::VisitLdaLookupSlot() {
 }
 
 void BaselineCompiler::VisitLdaLookupContextSlot() {
-  CallBuiltin(Builtins::kLookupContextBaseline, Constant<Name>(0),
-              UintAsTagged(2), IndexAsTagged(1));
+  CallBuiltin<Builtins::kLookupContextBaseline>(
+      Constant<Name>(0), UintAsTagged(2), IndexAsTagged(1));
 }
 
 void BaselineCompiler::VisitLdaLookupGlobalSlot() {
-  CallBuiltin(Builtins::kLookupGlobalICBaseline, Constant<Name>(0),
-              UintAsTagged(2), IndexAsTagged(1));
+  CallBuiltin<Builtins::kLookupGlobalICBaseline>(
+      Constant<Name>(0), UintAsTagged(2), IndexAsTagged(1));
 }
 
 void BaselineCompiler::VisitLdaLookupSlotInsideTypeof() {
@@ -744,13 +749,13 @@ void BaselineCompiler::VisitLdaLookupSlotInsideTypeof() {
 }
 
 void BaselineCompiler::VisitLdaLookupContextSlotInsideTypeof() {
-  CallBuiltin(Builtins::kLookupContextInsideTypeofBaseline, Constant<Name>(0),
-              UintAsTagged(2), IndexAsTagged(1));
+  CallBuiltin<Builtins::kLookupContextInsideTypeofBaseline>(
+      Constant<Name>(0), UintAsTagged(2), IndexAsTagged(1));
 }
 
 void BaselineCompiler::VisitLdaLookupGlobalSlotInsideTypeof() {
-  CallBuiltin(Builtins::kLookupGlobalICInsideTypeofBaseline, Constant<Name>(0),
-              UintAsTagged(2), IndexAsTagged(1));
+  CallBuiltin<Builtins::kLookupGlobalICInsideTypeofBaseline>(
+      Constant<Name>(0), UintAsTagged(2), IndexAsTagged(1));
 }
 
 void BaselineCompiler::VisitStaLookupSlot() {
@@ -793,14 +798,13 @@ void BaselineCompiler::VisitMov() {
 }
 
 void BaselineCompiler::VisitLdaNamedProperty() {
-  CallBuiltin(Builtins::kLoadICBaseline,
-              RegisterOperand(0),  // object
-              Constant<Name>(1),   // name
-              IndexAsTagged(2));   // slot
+  CallBuiltin<Builtins::kLoadICBaseline>(RegisterOperand(0),  // object
+                                         Constant<Name>(1),   // name
+                                         IndexAsTagged(2));   // slot
 }
 
 void BaselineCompiler::VisitLdaNamedPropertyNoFeedback() {
-  CallBuiltin(Builtins::kGetProperty, RegisterOperand(0), Constant<Name>(1));
+  CallBuiltin<Builtins::kGetProperty>(RegisterOperand(0), Constant<Name>(1));
 }
 
 void BaselineCompiler::VisitLdaNamedPropertyFromSuper() {
@@ -808,19 +812,19 @@ void BaselineCompiler::VisitLdaNamedPropertyFromSuper() {
       LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister(),
       kInterpreterAccumulatorRegister);
 
-  CallBuiltin(Builtins::kLoadSuperICBaseline,
-              RegisterOperand(0),  // object
-              LoadWithReceiverAndVectorDescriptor::
-                  LookupStartObjectRegister(),  // lookup start
-              Constant<Name>(1),                // name
-              IndexAsTagged(2));                // slot
+  CallBuiltin<Builtins::kLoadSuperICBaseline>(
+      RegisterOperand(0),  // object
+      LoadWithReceiverAndVectorDescriptor::
+          LookupStartObjectRegister(),  // lookup start
+      Constant<Name>(1),                // name
+      IndexAsTagged(2));                // slot
 }
 
 void BaselineCompiler::VisitLdaKeyedProperty() {
-  CallBuiltin(Builtins::kKeyedLoadICBaseline,
-              RegisterOperand(0),               // object
-              kInterpreterAccumulatorRegister,  // key
-              IndexAsTagged(1));                // slot
+  CallBuiltin<Builtins::kKeyedLoadICBaseline>(
+      RegisterOperand(0),               // object
+      kInterpreterAccumulatorRegister,  // key
+      IndexAsTagged(1));                // slot
 }
 
 void BaselineCompiler::VisitLdaModuleVariable() {
@@ -878,11 +882,11 @@ void BaselineCompiler::VisitStaModuleVariable() {
 }
 
 void BaselineCompiler::VisitStaNamedProperty() {
-  CallBuiltin(Builtins::kStoreICBaseline,
-              RegisterOperand(0),               // object
-              Constant<Name>(1),                // name
-              kInterpreterAccumulatorRegister,  // value
-              IndexAsTagged(2));                // slot
+  CallBuiltin<Builtins::kStoreICBaseline>(
+      RegisterOperand(0),               // object
+      Constant<Name>(1),                // name
+      kInterpreterAccumulatorRegister,  // value
+      IndexAsTagged(2));                // slot
 }
 
 void BaselineCompiler::VisitStaNamedPropertyNoFeedback() {
@@ -900,19 +904,19 @@ void BaselineCompiler::VisitStaNamedOwnProperty() {
 }
 
 void BaselineCompiler::VisitStaKeyedProperty() {
-  CallBuiltin(Builtins::kKeyedStoreICBaseline,
-              RegisterOperand(0),               // object
-              RegisterOperand(1),               // key
-              kInterpreterAccumulatorRegister,  // value
-              IndexAsTagged(2));                // slot
+  CallBuiltin<Builtins::kKeyedStoreICBaseline>(
+      RegisterOperand(0),               // object
+      RegisterOperand(1),               // key
+      kInterpreterAccumulatorRegister,  // value
+      IndexAsTagged(2));                // slot
 }
 
 void BaselineCompiler::VisitStaInArrayLiteral() {
-  CallBuiltin(Builtins::kStoreInArrayLiteralICBaseline,
-              RegisterOperand(0),               // object
-              RegisterOperand(1),               // name
-              kInterpreterAccumulatorRegister,  // value
-              IndexAsTagged(2));                // slot
+  CallBuiltin<Builtins::kStoreInArrayLiteralICBaseline>(
+      RegisterOperand(0),               // object
+      RegisterOperand(1),               // name
+      kInterpreterAccumulatorRegister,  // value
+      IndexAsTagged(2));                // slot
 }
 
 void BaselineCompiler::VisitStaDataPropertyInLiteral() {
@@ -934,140 +938,149 @@ void BaselineCompiler::VisitCollectTypeProfile() {
 }
 
 void BaselineCompiler::VisitAdd() {
-  CallBuiltin(Builtins::kAdd_Baseline, RegisterOperand(0),
-              kInterpreterAccumulatorRegister, Index(1));
+  CallBuiltin<Builtins::kAdd_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitSub() {
-  CallBuiltin(Builtins::kSubtract_Baseline, RegisterOperand(0),
-              kInterpreterAccumulatorRegister, Index(1));
+  CallBuiltin<Builtins::kSubtract_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitMul() {
-  CallBuiltin(Builtins::kMultiply_Baseline, RegisterOperand(0),
-              kInterpreterAccumulatorRegister, Index(1));
+  CallBuiltin<Builtins::kMultiply_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitDiv() {
-  CallBuiltin(Builtins::kDivide_Baseline, RegisterOperand(0),
-              kInterpreterAccumulatorRegister, Index(1));
+  CallBuiltin<Builtins::kDivide_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitMod() {
-  CallBuiltin(Builtins::kModulus_Baseline, RegisterOperand(0),
-              kInterpreterAccumulatorRegister, Index(1));
+  CallBuiltin<Builtins::kModulus_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitExp() {
-  CallBuiltin(Builtins::kExponentiate_Baseline, RegisterOperand(0),
-              kInterpreterAccumulatorRegister, Index(1));
+  CallBuiltin<Builtins::kExponentiate_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitBitwiseOr() {
-  CallBuiltin(Builtins::kBitwiseOr_Baseline, RegisterOperand(0),
-              kInterpreterAccumulatorRegister, Index(1));
+  CallBuiltin<Builtins::kBitwiseOr_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitBitwiseXor() {
-  CallBuiltin(Builtins::kBitwiseXor_Baseline, RegisterOperand(0),
-              kInterpreterAccumulatorRegister, Index(1));
+  CallBuiltin<Builtins::kBitwiseXor_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitBitwiseAnd() {
-  CallBuiltin(Builtins::kBitwiseAnd_Baseline, RegisterOperand(0),
-              kInterpreterAccumulatorRegister, Index(1));
+  CallBuiltin<Builtins::kBitwiseAnd_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitShiftLeft() {
-  CallBuiltin(Builtins::kShiftLeft_Baseline, RegisterOperand(0),
-              kInterpreterAccumulatorRegister, Index(1));
+  CallBuiltin<Builtins::kShiftLeft_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitShiftRight() {
-  CallBuiltin(Builtins::kShiftRight_Baseline, RegisterOperand(0),
-              kInterpreterAccumulatorRegister, Index(1));
+  CallBuiltin<Builtins::kShiftRight_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitShiftRightLogical() {
-  CallBuiltin(Builtins::kShiftRightLogical_Baseline, RegisterOperand(0),
-              kInterpreterAccumulatorRegister, Index(1));
-}
-
-void BaselineCompiler::BuildBinopWithConstant(Builtins::Name builtin_name) {
-  CallBuiltin(builtin_name, kInterpreterAccumulatorRegister, IntAsSmi(0),
-              Index(1));
+  CallBuiltin<Builtins::kShiftRightLogical_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitAddSmi() {
-  BuildBinopWithConstant(Builtins::kAdd_Baseline);
+  CallBuiltin<Builtins::kAdd_Baseline>(kInterpreterAccumulatorRegister,
+                                       IntAsSmi(0), Index(1));
 }
 
 void BaselineCompiler::VisitSubSmi() {
-  BuildBinopWithConstant(Builtins::kSubtract_Baseline);
+  CallBuiltin<Builtins::kSubtract_Baseline>(kInterpreterAccumulatorRegister,
+                                            IntAsSmi(0), Index(1));
 }
 
 void BaselineCompiler::VisitMulSmi() {
-  BuildBinopWithConstant(Builtins::kMultiply_Baseline);
+  CallBuiltin<Builtins::kMultiply_Baseline>(kInterpreterAccumulatorRegister,
+                                            IntAsSmi(0), Index(1));
 }
 
 void BaselineCompiler::VisitDivSmi() {
-  BuildBinopWithConstant(Builtins::kDivide_Baseline);
+  CallBuiltin<Builtins::kDivide_Baseline>(kInterpreterAccumulatorRegister,
+                                          IntAsSmi(0), Index(1));
 }
 
 void BaselineCompiler::VisitModSmi() {
-  BuildBinopWithConstant(Builtins::kModulus_Baseline);
+  CallBuiltin<Builtins::kModulus_Baseline>(kInterpreterAccumulatorRegister,
+                                           IntAsSmi(0), Index(1));
 }
 
 void BaselineCompiler::VisitExpSmi() {
-  BuildBinopWithConstant(Builtins::kExponentiate_Baseline);
+  CallBuiltin<Builtins::kExponentiate_Baseline>(kInterpreterAccumulatorRegister,
+                                                IntAsSmi(0), Index(1));
 }
 
 void BaselineCompiler::VisitBitwiseOrSmi() {
-  BuildBinopWithConstant(Builtins::kBitwiseOr_Baseline);
+  CallBuiltin<Builtins::kBitwiseOr_Baseline>(kInterpreterAccumulatorRegister,
+                                             IntAsSmi(0), Index(1));
 }
 
 void BaselineCompiler::VisitBitwiseXorSmi() {
-  BuildBinopWithConstant(Builtins::kBitwiseXor_Baseline);
+  CallBuiltin<Builtins::kBitwiseXor_Baseline>(kInterpreterAccumulatorRegister,
+                                              IntAsSmi(0), Index(1));
 }
 
 void BaselineCompiler::VisitBitwiseAndSmi() {
-  BuildBinopWithConstant(Builtins::kBitwiseAnd_Baseline);
+  CallBuiltin<Builtins::kBitwiseAnd_Baseline>(kInterpreterAccumulatorRegister,
+                                              IntAsSmi(0), Index(1));
 }
 
 void BaselineCompiler::VisitShiftLeftSmi() {
-  BuildBinopWithConstant(Builtins::kShiftLeft_Baseline);
+  CallBuiltin<Builtins::kShiftLeft_Baseline>(kInterpreterAccumulatorRegister,
+                                             IntAsSmi(0), Index(1));
 }
 
 void BaselineCompiler::VisitShiftRightSmi() {
-  BuildBinopWithConstant(Builtins::kShiftRight_Baseline);
+  CallBuiltin<Builtins::kShiftRight_Baseline>(kInterpreterAccumulatorRegister,
+                                              IntAsSmi(0), Index(1));
 }
 
 void BaselineCompiler::VisitShiftRightLogicalSmi() {
-  BuildBinopWithConstant(Builtins::kShiftRightLogical_Baseline);
+  CallBuiltin<Builtins::kShiftRightLogical_Baseline>(
+      kInterpreterAccumulatorRegister, IntAsSmi(0), Index(1));
 }
 
-void BaselineCompiler::BuildUnop(Builtins::Name builtin_name) {
-  CallBuiltin(builtin_name,
-              kInterpreterAccumulatorRegister,  // value
-              Index(0));                        // slot
+void BaselineCompiler::VisitInc() {
+  CallBuiltin<Builtins::kIncrement_Baseline>(kInterpreterAccumulatorRegister,
+                                             Index(0));
 }
 
-void BaselineCompiler::VisitInc() { BuildUnop(Builtins::kIncrement_Baseline); }
-
-void BaselineCompiler::VisitDec() { BuildUnop(Builtins::kDecrement_Baseline); }
+void BaselineCompiler::VisitDec() {
+  CallBuiltin<Builtins::kDecrement_Baseline>(kInterpreterAccumulatorRegister,
+                                             Index(0));
+}
 
-void BaselineCompiler::VisitNegate() { BuildUnop(Builtins::kNegate_Baseline); }
+void BaselineCompiler::VisitNegate() {
+  CallBuiltin<Builtins::kNegate_Baseline>(kInterpreterAccumulatorRegister,
+                                          Index(0));
+}
 
 void BaselineCompiler::VisitBitwiseNot() {
-  BuildUnop(Builtins::kBitwiseNot_Baseline);
+  CallBuiltin<Builtins::kBitwiseNot_Baseline>(kInterpreterAccumulatorRegister,
+                                              Index(0));
 }
 
 void BaselineCompiler::VisitToBooleanLogicalNot() {
   SelectBooleanConstant(kInterpreterAccumulatorRegister,
                         [&](Label* if_true, Label::Distance distance) {
-                          JumpIfToBoolean(false,
-                                          kInterpreterAccumulatorRegister,
-                                          if_true, distance);
+                          JumpIfToBoolean(false, if_true, distance);
                         });
 }
 
@@ -1081,23 +1094,23 @@ void BaselineCompiler::VisitLogicalNot() {
 }
 
 void BaselineCompiler::VisitTypeOf() {
-  CallBuiltin(Builtins::kTypeof, kInterpreterAccumulatorRegister);
+  CallBuiltin<Builtins::kTypeof>(kInterpreterAccumulatorRegister);
 }
 
 void BaselineCompiler::VisitDeletePropertyStrict() {
   BaselineAssembler::ScratchRegisterScope scratch_scope(&basm_);
   Register scratch = scratch_scope.AcquireScratch();
   __ Move(scratch, kInterpreterAccumulatorRegister);
-  CallBuiltin(Builtins::kDeleteProperty, RegisterOperand(0), scratch,
-              Smi::FromEnum(LanguageMode::kStrict));
+  CallBuiltin<Builtins::kDeleteProperty>(RegisterOperand(0), scratch,
+                                         Smi::FromEnum(LanguageMode::kStrict));
 }
 
 void BaselineCompiler::VisitDeletePropertySloppy() {
   BaselineAssembler::ScratchRegisterScope scratch_scope(&basm_);
   Register scratch = scratch_scope.AcquireScratch();
   __ Move(scratch, kInterpreterAccumulatorRegister);
-  CallBuiltin(Builtins::kDeleteProperty, RegisterOperand(0), scratch,
-              Smi::FromEnum(LanguageMode::kSloppy));
+  CallBuiltin<Builtins::kDeleteProperty>(RegisterOperand(0), scratch,
+                                         Smi::FromEnum(LanguageMode::kSloppy));
 }
 
 void BaselineCompiler::VisitGetSuperConstructor() {
@@ -1106,87 +1119,115 @@ void BaselineCompiler::VisitGetSuperConstructor() {
   __ LoadPrototype(prototype, kInterpreterAccumulatorRegister);
   StoreRegister(0, prototype);
 }
-template <typename... Args>
-void BaselineCompiler::BuildCall(ConvertReceiverMode mode, uint32_t slot,
-                                 uint32_t arg_count, Args... args) {
-  Builtins::Name builtin;
+
+namespace {
+constexpr Builtins::Name ConvertReceiverModeToCompactBuiltin(
+    ConvertReceiverMode mode) {
   switch (mode) {
     case ConvertReceiverMode::kAny:
-      builtin = Builtins::kCall_ReceiverIsAny_Baseline;
+      return Builtins::kCall_ReceiverIsAny_Baseline_Compact;
       break;
     case ConvertReceiverMode::kNullOrUndefined:
-      builtin = Builtins::kCall_ReceiverIsNullOrUndefined_Baseline;
+      return Builtins::kCall_ReceiverIsNullOrUndefined_Baseline_Compact;
       break;
     case ConvertReceiverMode::kNotNullOrUndefined:
-      builtin = Builtins::kCall_ReceiverIsNotNullOrUndefined_Baseline;
+      return Builtins::kCall_ReceiverIsNotNullOrUndefined_Baseline_Compact;
       break;
-    default:
-      UNREACHABLE();
   }
-  CallBuiltin(builtin,
-              RegisterOperand(0),  // kFunction
-              arg_count,           // kActualArgumentsCount
-              slot,                // kSlot
-              args...);            // Arguments
+}
+constexpr Builtins::Name ConvertReceiverModeToBuiltin(
+    ConvertReceiverMode mode) {
+  switch (mode) {
+    case ConvertReceiverMode::kAny:
+      return Builtins::kCall_ReceiverIsAny_Baseline;
+      break;
+    case ConvertReceiverMode::kNullOrUndefined:
+      return Builtins::kCall_ReceiverIsNullOrUndefined_Baseline;
+      break;
+    case ConvertReceiverMode::kNotNullOrUndefined:
+      return Builtins::kCall_ReceiverIsNotNullOrUndefined_Baseline;
+      break;
+  }
+}
+}  // namespace
+
+template <ConvertReceiverMode kMode, typename... Args>
+void BaselineCompiler::BuildCall(uint32_t slot, uint32_t arg_count,
+                                 Args... args) {
+  uint32_t bitfield;
+  if (CallTrampoline_Baseline_CompactDescriptor::EncodeBitField(arg_count, slot,
+                                                                &bitfield)) {
+    CallBuiltin<ConvertReceiverModeToCompactBuiltin(kMode)>(
+        RegisterOperand(0),  // kFunction
+        bitfield,            // kActualArgumentsCount | kSlot
+        args...);            // Arguments
+  } else {
+    CallBuiltin<ConvertReceiverModeToBuiltin(kMode)>(
+        RegisterOperand(0),  // kFunction
+        arg_count,           // kActualArgumentsCount
+        slot,                // kSlot
+        args...);            // Arguments
+  }
 }
 
 void BaselineCompiler::VisitCallAnyReceiver() {
   interpreter::RegisterList args = iterator().GetRegisterListOperand(1);
   uint32_t arg_count = args.register_count() - 1;  // Remove receiver.
-  BuildCall(ConvertReceiverMode::kAny, Index(3), arg_count, args);
+  BuildCall<ConvertReceiverMode::kAny>(Index(3), arg_count, args);
 }
 
 void BaselineCompiler::VisitCallProperty() {
   interpreter::RegisterList args = iterator().GetRegisterListOperand(1);
   uint32_t arg_count = args.register_count() - 1;  // Remove receiver.
-  BuildCall(ConvertReceiverMode::kNotNullOrUndefined, Index(3), arg_count,
-            args);
+  BuildCall<ConvertReceiverMode::kNotNullOrUndefined>(Index(3), arg_count,
+                                                      args);
 }
 
 void BaselineCompiler::VisitCallProperty0() {
-  BuildCall(ConvertReceiverMode::kNotNullOrUndefined, Index(2), 0,
-            RegisterOperand(1));
+  BuildCall<ConvertReceiverMode::kNotNullOrUndefined>(Index(2), 0,
+                                                      RegisterOperand(1));
 }
 
 void BaselineCompiler::VisitCallProperty1() {
-  BuildCall(ConvertReceiverMode::kNotNullOrUndefined, Index(3), 1,
-            RegisterOperand(1), RegisterOperand(2));
+  BuildCall<ConvertReceiverMode::kNotNullOrUndefined>(
+      Index(3), 1, RegisterOperand(1), RegisterOperand(2));
 }
 
 void BaselineCompiler::VisitCallProperty2() {
-  BuildCall(ConvertReceiverMode::kNotNullOrUndefined, Index(4), 2,
-            RegisterOperand(1), RegisterOperand(2), RegisterOperand(3));
+  BuildCall<ConvertReceiverMode::kNotNullOrUndefined>(
+      Index(4), 2, RegisterOperand(1), RegisterOperand(2), RegisterOperand(3));
 }
 
 void BaselineCompiler::VisitCallUndefinedReceiver() {
   interpreter::RegisterList args = iterator().GetRegisterListOperand(1);
   uint32_t arg_count = args.register_count();
-  BuildCall(ConvertReceiverMode::kNullOrUndefined, Index(3), arg_count,
-            RootIndex::kUndefinedValue, args);
+  BuildCall<ConvertReceiverMode::kNullOrUndefined>(
+      Index(3), arg_count, RootIndex::kUndefinedValue, args);
 }
 
 void BaselineCompiler::VisitCallUndefinedReceiver0() {
-  BuildCall(ConvertReceiverMode::kNullOrUndefined, Index(1), 0,
-            RootIndex::kUndefinedValue);
+  BuildCall<ConvertReceiverMode::kNullOrUndefined>(Index(1), 0,
+                                                   RootIndex::kUndefinedValue);
 }
 
 void BaselineCompiler::VisitCallUndefinedReceiver1() {
-  BuildCall(ConvertReceiverMode::kNullOrUndefined, Index(2), 1,
-            RootIndex::kUndefinedValue, RegisterOperand(1));
+  BuildCall<ConvertReceiverMode::kNullOrUndefined>(
+      Index(2), 1, RootIndex::kUndefinedValue, RegisterOperand(1));
 }
 
 void BaselineCompiler::VisitCallUndefinedReceiver2() {
-  BuildCall(ConvertReceiverMode::kNullOrUndefined, Index(3), 2,
-            RootIndex::kUndefinedValue, RegisterOperand(1), RegisterOperand(2));
+  BuildCall<ConvertReceiverMode::kNullOrUndefined>(
+      Index(3), 2, RootIndex::kUndefinedValue, RegisterOperand(1),
+      RegisterOperand(2));
 }
 
 void BaselineCompiler::VisitCallNoFeedback() {
   interpreter::RegisterList args = iterator().GetRegisterListOperand(1);
   uint32_t arg_count = args.register_count();
-  CallBuiltin(Builtins::kCall_ReceiverIsAny,
-              RegisterOperand(0),  // kFunction
-              arg_count - 1,       // kActualArgumentsCount
-              args);
+  CallBuiltin<Builtins::kCall_ReceiverIsAny>(
+      RegisterOperand(0),  // kFunction
+      arg_count - 1,       // kActualArgumentsCount
+      args);
 }
 
 void BaselineCompiler::VisitCallWithSpread() {
@@ -1198,12 +1239,12 @@ void BaselineCompiler::VisitCallWithSpread() {
 
   uint32_t arg_count = args.register_count() - 1;  // Remove receiver.
 
-  CallBuiltin(Builtins::kCallWithSpread_Baseline,
-              RegisterOperand(0),  // kFunction
-              arg_count,           // kActualArgumentsCount
-              spread_register,     // kSpread
-              Index(3),            // kSlot
-              args);
+  CallBuiltin<Builtins::kCallWithSpread_Baseline>(
+      RegisterOperand(0),  // kFunction
+      arg_count,           // kActualArgumentsCount
+      spread_register,     // kSpread
+      Index(3),            // kSlot
+      args);
 }
 
 void BaselineCompiler::VisitCallRuntime() {
@@ -1226,11 +1267,11 @@ void BaselineCompiler::VisitCallJSRuntime() {
   __ LoadContext(kContextRegister);
   __ LoadNativeContextSlot(kJavaScriptCallTargetRegister,
                            iterator().GetNativeContextIndexOperand(0));
-  CallBuiltin(Builtins::kCall_ReceiverIsNullOrUndefined,
-              kJavaScriptCallTargetRegister,  // kFunction
-              arg_count,                      // kActualArgumentsCount
-              RootIndex::kUndefinedValue,     // kReceiver
-              args);
+  CallBuiltin<Builtins::kCall_ReceiverIsNullOrUndefined>(
+      kJavaScriptCallTargetRegister,  // kFunction
+      arg_count,                      // kActualArgumentsCount
+      RootIndex::kUndefinedValue,     // kReceiver
+      args);
 }
 
 void BaselineCompiler::VisitInvokeIntrinsic() {
@@ -1301,29 +1342,25 @@ void BaselineCompiler::VisitIntrinsicIsSmi(interpreter::RegisterList args) {
 
 void BaselineCompiler::VisitIntrinsicCopyDataProperties(
     interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kCopyDataProperties, args);
+  CallBuiltin<Builtins::kCopyDataProperties>(args);
 }
 
 void BaselineCompiler::VisitIntrinsicCreateIterResultObject(
     interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kCreateIterResultObject, args);
+  CallBuiltin<Builtins::kCreateIterResultObject>(args);
 }
 
 void BaselineCompiler::VisitIntrinsicHasProperty(
     interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kHasProperty, args);
-}
-
-void BaselineCompiler::VisitIntrinsicToString(interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kToString, args);
+  CallBuiltin<Builtins::kHasProperty>(args);
 }
 
 void BaselineCompiler::VisitIntrinsicToLength(interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kToLength, args);
+  CallBuiltin<Builtins::kToLength>(args);
 }
 
 void BaselineCompiler::VisitIntrinsicToObject(interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kToObject, args);
+  CallBuiltin<Builtins::kToObject>(args);
 }
 
 void BaselineCompiler::VisitIntrinsicCall(interpreter::RegisterList args) {
@@ -1335,20 +1372,20 @@ void BaselineCompiler::VisitIntrinsicCall(interpreter::RegisterList args) {
   args = args.PopLeft();
 
   uint32_t arg_count = args.register_count();
-  CallBuiltin(Builtins::kCall_ReceiverIsAny,
-              kJavaScriptCallTargetRegister,  // kFunction
-              arg_count - 1,                  // kActualArgumentsCount
-              args);
+  CallBuiltin<Builtins::kCall_ReceiverIsAny>(
+      kJavaScriptCallTargetRegister,  // kFunction
+      arg_count - 1,                  // kActualArgumentsCount
+      args);
 }
 
 void BaselineCompiler::VisitIntrinsicCreateAsyncFromSyncIterator(
     interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kCreateAsyncFromSyncIteratorBaseline, args[0]);
+  CallBuiltin<Builtins::kCreateAsyncFromSyncIteratorBaseline>(args[0]);
 }
 
 void BaselineCompiler::VisitIntrinsicCreateJSGeneratorObject(
     interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kCreateGeneratorObject, args);
+  CallBuiltin<Builtins::kCreateGeneratorObject>(args);
 }
 
 void BaselineCompiler::VisitIntrinsicGeneratorGetResumeMode(
@@ -1370,69 +1407,69 @@ void BaselineCompiler::VisitIntrinsicGeneratorClose(
 
 void BaselineCompiler::VisitIntrinsicGetImportMetaObject(
     interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kGetImportMetaObjectBaseline);
+  CallBuiltin<Builtins::kGetImportMetaObjectBaseline>();
 }
 
 void BaselineCompiler::VisitIntrinsicAsyncFunctionAwaitCaught(
     interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kAsyncFunctionAwaitCaught, args);
+  CallBuiltin<Builtins::kAsyncFunctionAwaitCaught>(args);
 }
 
 void BaselineCompiler::VisitIntrinsicAsyncFunctionAwaitUncaught(
     interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kAsyncFunctionAwaitUncaught, args);
+  CallBuiltin<Builtins::kAsyncFunctionAwaitUncaught>(args);
 }
 
 void BaselineCompiler::VisitIntrinsicAsyncFunctionEnter(
     interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kAsyncFunctionEnter, args);
+  CallBuiltin<Builtins::kAsyncFunctionEnter>(args);
 }
 
 void BaselineCompiler::VisitIntrinsicAsyncFunctionReject(
     interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kAsyncFunctionReject, args);
+  CallBuiltin<Builtins::kAsyncFunctionReject>(args);
 }
 
 void BaselineCompiler::VisitIntrinsicAsyncFunctionResolve(
     interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kAsyncFunctionResolve, args);
+  CallBuiltin<Builtins::kAsyncFunctionResolve>(args);
 }
 
 void BaselineCompiler::VisitIntrinsicAsyncGeneratorAwaitCaught(
     interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kAsyncGeneratorAwaitCaught, args);
+  CallBuiltin<Builtins::kAsyncGeneratorAwaitCaught>(args);
 }
 
 void BaselineCompiler::VisitIntrinsicAsyncGeneratorAwaitUncaught(
     interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kAsyncGeneratorAwaitUncaught, args);
+  CallBuiltin<Builtins::kAsyncGeneratorAwaitUncaught>(args);
 }
 
 void BaselineCompiler::VisitIntrinsicAsyncGeneratorReject(
     interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kAsyncGeneratorReject, args);
+  CallBuiltin<Builtins::kAsyncGeneratorReject>(args);
 }
 
 void BaselineCompiler::VisitIntrinsicAsyncGeneratorResolve(
     interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kAsyncGeneratorResolve, args);
+  CallBuiltin<Builtins::kAsyncGeneratorResolve>(args);
 }
 
 void BaselineCompiler::VisitIntrinsicAsyncGeneratorYield(
     interpreter::RegisterList args) {
-  CallBuiltin(Builtins::kAsyncGeneratorYield, args);
+  CallBuiltin<Builtins::kAsyncGeneratorYield>(args);
 }
 
 void BaselineCompiler::VisitConstruct() {
   interpreter::RegisterList args = iterator().GetRegisterListOperand(1);
   uint32_t arg_count = args.register_count();
-  CallBuiltin(Builtins::kConstruct_Baseline,
-              RegisterOperand(0),               // kFunction
-              kInterpreterAccumulatorRegister,  // kNewTarget
-              arg_count,                        // kActualArgumentsCount
-              Index(3),                         // kSlot
-              RootIndex::kUndefinedValue,       // kReceiver
-              args);
+  CallBuiltin<Builtins::kConstruct_Baseline>(
+      RegisterOperand(0),               // kFunction
+      kInterpreterAccumulatorRegister,  // kNewTarget
+      arg_count,                        // kActualArgumentsCount
+      Index(3),                         // kSlot
+      RootIndex::kUndefinedValue,       // kReceiver
+      args);
 }
 
 void BaselineCompiler::VisitConstructWithSpread() {
@@ -1444,51 +1481,50 @@ void BaselineCompiler::VisitConstructWithSpread() {
 
   uint32_t arg_count = args.register_count();
 
+  using Descriptor =
+      CallInterfaceDescriptorFor<Builtins::kConstructWithSpread_Baseline>::type;
   Register new_target =
-      Builtins::CallInterfaceDescriptorFor(
-          Builtins::kConstructWithSpread_Baseline)
-          .GetRegisterParameter(
-              ConstructWithSpread_BaselineDescriptor::kNewTarget);
+      Descriptor::GetRegisterParameter(Descriptor::kNewTarget);
   __ Move(new_target, kInterpreterAccumulatorRegister);
 
-  CallBuiltin(Builtins::kConstructWithSpread_Baseline,
-              RegisterOperand(0),          // kFunction
-              new_target,                  // kNewTarget
-              arg_count,                   // kActualArgumentsCount
-              Index(3),                    // kSlot
-              spread_register,             // kSpread
-              RootIndex::kUndefinedValue,  // kReceiver
-              args);
-}
-
-void BaselineCompiler::BuildCompare(Builtins::Name builtin_name) {
-  CallBuiltin(builtin_name, RegisterOperand(0),  // lhs
-              kInterpreterAccumulatorRegister,   // rhs
-              Index(1));                         // slot
+  CallBuiltin<Builtins::kConstructWithSpread_Baseline>(
+      RegisterOperand(0),          // kFunction
+      new_target,                  // kNewTarget
+      arg_count,                   // kActualArgumentsCount
+      Index(3),                    // kSlot
+      spread_register,             // kSpread
+      RootIndex::kUndefinedValue,  // kReceiver
+      args);
 }
 
 void BaselineCompiler::VisitTestEqual() {
-  BuildCompare(Builtins::kEqual_Baseline);
+  CallBuiltin<Builtins::kEqual_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitTestEqualStrict() {
-  BuildCompare(Builtins::kStrictEqual_Baseline);
+  CallBuiltin<Builtins::kStrictEqual_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitTestLessThan() {
-  BuildCompare(Builtins::kLessThan_Baseline);
+  CallBuiltin<Builtins::kLessThan_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitTestGreaterThan() {
-  BuildCompare(Builtins::kGreaterThan_Baseline);
+  CallBuiltin<Builtins::kGreaterThan_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitTestLessThanOrEqual() {
-  BuildCompare(Builtins::kLessThanOrEqual_Baseline);
+  CallBuiltin<Builtins::kLessThanOrEqual_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitTestGreaterThanOrEqual() {
-  BuildCompare(Builtins::kGreaterThanOrEqual_Baseline);
+  CallBuiltin<Builtins::kGreaterThanOrEqual_Baseline>(
+      RegisterOperand(0), kInterpreterAccumulatorRegister, Index(1));
 }
 
 void BaselineCompiler::VisitTestReferenceEqual() {
@@ -1502,21 +1538,21 @@ void BaselineCompiler::VisitTestReferenceEqual() {
 }
 
 void BaselineCompiler::VisitTestInstanceOf() {
-  Register callable =
-      Builtins::CallInterfaceDescriptorFor(Builtins::kInstanceOf_Baseline)
-          .GetRegisterParameter(Compare_BaselineDescriptor::kRight);
+  using Descriptor =
+      CallInterfaceDescriptorFor<Builtins::kInstanceOf_Baseline>::type;
+  Register callable = Descriptor::GetRegisterParameter(Descriptor::kRight);
   __ Move(callable, kInterpreterAccumulatorRegister);
-  CallBuiltin(Builtins::kInstanceOf_Baseline,
-              RegisterOperand(0),  // object
-              callable,            // callable
-              Index(1));           // slot
+
+  CallBuiltin<Builtins::kInstanceOf_Baseline>(RegisterOperand(0),  // object
+                                              callable,            // callable
+                                              Index(1));           // slot
 }
 
 void BaselineCompiler::VisitTestIn() {
-  CallBuiltin(Builtins::kKeyedHasICBaseline,
-              kInterpreterAccumulatorRegister,  // object
-              RegisterOperand(0),               // name
-              IndexAsTagged(1));                // slot
+  CallBuiltin<Builtins::kKeyedHasICBaseline>(
+      kInterpreterAccumulatorRegister,  // object
+      RegisterOperand(0),               // name
+      IndexAsTagged(1));                // slot
 }
 
 void BaselineCompiler::VisitTestUndetectable() {
@@ -1727,36 +1763,36 @@ void BaselineCompiler::VisitTestTypeOf() {
 
 void BaselineCompiler::VisitToName() {
   SaveAccumulatorScope save_accumulator(&basm_);
-  CallBuiltin(Builtins::kToName, kInterpreterAccumulatorRegister);
+  CallBuiltin<Builtins::kToName>(kInterpreterAccumulatorRegister);
   StoreRegister(0, kInterpreterAccumulatorRegister);
 }
 
 void BaselineCompiler::VisitToNumber() {
-  CallBuiltin(Builtins::kToNumber_Baseline, kInterpreterAccumulatorRegister,
-              Index(0));
+  CallBuiltin<Builtins::kToNumber_Baseline>(kInterpreterAccumulatorRegister,
+                                            Index(0));
 }
 
 void BaselineCompiler::VisitToNumeric() {
-  CallBuiltin(Builtins::kToNumeric_Baseline, kInterpreterAccumulatorRegister,
-              Index(0));
+  CallBuiltin<Builtins::kToNumeric_Baseline>(kInterpreterAccumulatorRegister,
+                                             Index(0));
 }
 
 void BaselineCompiler::VisitToObject() {
   SaveAccumulatorScope save_accumulator(&basm_);
-  CallBuiltin(Builtins::kToObject, kInterpreterAccumulatorRegister);
+  CallBuiltin<Builtins::kToObject>(kInterpreterAccumulatorRegister);
   StoreRegister(0, kInterpreterAccumulatorRegister);
 }
 
 void BaselineCompiler::VisitToString() {
-  CallBuiltin(Builtins::kToString, kInterpreterAccumulatorRegister);
+  CallBuiltin<Builtins::kToString>(kInterpreterAccumulatorRegister);
 }
 
 void BaselineCompiler::VisitCreateRegExpLiteral() {
-  CallBuiltin(Builtins::kCreateRegExpLiteral,
-              FeedbackVector(),         // feedback vector
-              IndexAsTagged(1),         // slot
-              Constant<HeapObject>(0),  // pattern
-              FlagAsSmi(2));            // flags
+  CallBuiltin<Builtins::kCreateRegExpLiteral>(
+      FeedbackVector(),         // feedback vector
+      IndexAsTagged(1),         // slot
+      Constant<HeapObject>(0),  // pattern
+      FlagAsSmi(2));            // flags
 }
 
 void BaselineCompiler::VisitCreateArrayLiteral() {
@@ -1765,11 +1801,11 @@ void BaselineCompiler::VisitCreateArrayLiteral() {
       interpreter::CreateArrayLiteralFlags::FlagsBits::decode(flags));
   if (flags &
       interpreter::CreateArrayLiteralFlags::FastCloneSupportedBit::kMask) {
-    CallBuiltin(Builtins::kCreateShallowArrayLiteral,
-                FeedbackVector(),          // feedback vector
-                IndexAsTagged(1),          // slot
-                Constant<HeapObject>(0),   // constant elements
-                Smi::FromInt(flags_raw));  // flags
+    CallBuiltin<Builtins::kCreateShallowArrayLiteral>(
+        FeedbackVector(),          // feedback vector
+        IndexAsTagged(1),          // slot
+        Constant<HeapObject>(0),   // constant elements
+        Smi::FromInt(flags_raw));  // flags
   } else {
     CallRuntime(Runtime::kCreateArrayLiteral,
                 FeedbackVector(),          // feedback vector
@@ -1780,13 +1816,13 @@ void BaselineCompiler::VisitCreateArrayLiteral() {
 }
 
 void BaselineCompiler::VisitCreateArrayFromIterable() {
-  CallBuiltin(Builtins::kIterableToListWithSymbolLookup,
-              kInterpreterAccumulatorRegister);  // iterable
+  CallBuiltin<Builtins::kIterableToListWithSymbolLookup>(
+      kInterpreterAccumulatorRegister);  // iterable
 }
 
 void BaselineCompiler::VisitCreateEmptyArrayLiteral() {
-  CallBuiltin(Builtins::kCreateEmptyArrayLiteral, FeedbackVector(),
-              IndexAsTagged(0));
+  CallBuiltin<Builtins::kCreateEmptyArrayLiteral>(FeedbackVector(),
+                                                  IndexAsTagged(0));
 }
 
 void BaselineCompiler::VisitCreateObjectLiteral() {
@@ -1795,11 +1831,11 @@ void BaselineCompiler::VisitCreateObjectLiteral() {
       interpreter::CreateObjectLiteralFlags::FlagsBits::decode(flags));
   if (flags &
       interpreter::CreateObjectLiteralFlags::FastCloneSupportedBit::kMask) {
-    CallBuiltin(Builtins::kCreateShallowObjectLiteral,
-                FeedbackVector(),                           // feedback vector
-                IndexAsTagged(1),                           // slot
-                Constant<ObjectBoilerplateDescription>(0),  // boilerplate
-                Smi::FromInt(flags_raw));                   // flags
+    CallBuiltin<Builtins::kCreateShallowObjectLiteral>(
+        FeedbackVector(),                           // feedback vector
+        IndexAsTagged(1),                           // slot
+        Constant<ObjectBoilerplateDescription>(0),  // boilerplate
+        Smi::FromInt(flags_raw));                   // flags
   } else {
     CallRuntime(Runtime::kCreateObjectLiteral,
                 FeedbackVector(),                           // feedback vector
@@ -1810,39 +1846,39 @@ void BaselineCompiler::VisitCreateObjectLiteral() {
 }
 
 void BaselineCompiler::VisitCreateEmptyObjectLiteral() {
-  CallBuiltin(Builtins::kCreateEmptyLiteralObject);
+  CallBuiltin<Builtins::kCreateEmptyLiteralObject>();
 }
 
 void BaselineCompiler::VisitCloneObject() {
   uint32_t flags = Flag(1);
   int32_t raw_flags =
       interpreter::CreateObjectLiteralFlags::FlagsBits::decode(flags);
-  CallBuiltin(Builtins::kCloneObjectICBaseline,
-              RegisterOperand(0),       // source
-              Smi::FromInt(raw_flags),  // flags
-              IndexAsTagged(2));        // slot
+  CallBuiltin<Builtins::kCloneObjectICBaseline>(
+      RegisterOperand(0),       // source
+      Smi::FromInt(raw_flags),  // flags
+      IndexAsTagged(2));        // slot
 }
 
 void BaselineCompiler::VisitGetTemplateObject() {
   BaselineAssembler::ScratchRegisterScope scratch_scope(&basm_);
-  CallBuiltin(Builtins::kGetTemplateObject,
-              shared_function_info_,    // shared function info
-              Constant<HeapObject>(0),  // description
-              Index(1),                 // slot
-              FeedbackVector());        // feedback_vector
+  CallBuiltin<Builtins::kGetTemplateObject>(
+      shared_function_info_,    // shared function info
+      Constant<HeapObject>(0),  // description
+      Index(1),                 // slot
+      FeedbackVector());        // feedback_vector
 }
 
 void BaselineCompiler::VisitCreateClosure() {
   Register feedback_cell =
-      Builtins::CallInterfaceDescriptorFor(Builtins::kFastNewClosure)
-          .GetRegisterParameter(FastNewClosureDescriptor::kFeedbackCell);
+      FastNewClosureBaselineDescriptor::GetRegisterParameter(
+          FastNewClosureBaselineDescriptor::kFeedbackCell);
   LoadClosureFeedbackArray(feedback_cell);
   __ LoadFixedArrayElement(feedback_cell, feedback_cell, Index(1));
 
   uint32_t flags = Flag(2);
   if (interpreter::CreateClosureFlags::FastNewClosureBit::decode(flags)) {
-    CallBuiltin(Builtins::kFastNewClosure, Constant<SharedFunctionInfo>(0),
-                feedback_cell);
+    CallBuiltin<Builtins::kFastNewClosureBaseline>(
+        Constant<SharedFunctionInfo>(0), feedback_cell);
   } else {
     Runtime::FunctionId function_id =
         interpreter::CreateClosureFlags::PretenuredBit::decode(flags)
@@ -1868,7 +1904,7 @@ void BaselineCompiler::VisitCreateFunctionContext() {
   if (slot_count < static_cast<uint32_t>(
                        ConstructorBuiltins::MaximumFunctionContextSlots())) {
     DCHECK_EQ(info->scope_type(), ScopeType::FUNCTION_SCOPE);
-    CallBuiltin(Builtins::kFastNewFunctionContextFunction, info, slot_count);
+    CallBuiltin<Builtins::kFastNewFunctionContextFunction>(info, slot_count);
   } else {
     CallRuntime(Runtime::kNewFunctionContext, Constant<ScopeInfo>(0));
   }
@@ -1880,7 +1916,7 @@ void BaselineCompiler::VisitCreateEvalContext() {
   if (slot_count < static_cast<uint32_t>(
                        ConstructorBuiltins::MaximumFunctionContextSlots())) {
     DCHECK_EQ(info->scope_type(), ScopeType::EVAL_SCOPE);
-    CallBuiltin(Builtins::kFastNewFunctionContextEval, info, slot_count);
+    CallBuiltin<Builtins::kFastNewFunctionContextEval>(info, slot_count);
   } else {
     CallRuntime(Runtime::kNewFunctionContext, Constant<ScopeInfo>(0));
   }
@@ -1896,16 +1932,16 @@ void BaselineCompiler::VisitCreateMappedArguments() {
   if (shared_function_info_->has_duplicate_parameters()) {
     CallRuntime(Runtime::kNewSloppyArguments, __ FunctionOperand());
   } else {
-    CallBuiltin(Builtins::kFastNewSloppyArguments, __ FunctionOperand());
+    CallBuiltin<Builtins::kFastNewSloppyArguments>(__ FunctionOperand());
   }
 }
 
 void BaselineCompiler::VisitCreateUnmappedArguments() {
-  CallBuiltin(Builtins::kFastNewStrictArguments, __ FunctionOperand());
+  CallBuiltin<Builtins::kFastNewStrictArguments>(__ FunctionOperand());
 }
 
 void BaselineCompiler::VisitCreateRestParameter() {
-  CallBuiltin(Builtins::kFastNewRestArguments, __ FunctionOperand());
+  CallBuiltin<Builtins::kFastNewRestArguments>(__ FunctionOperand());
 }
 
 void BaselineCompiler::VisitJumpLoop() {
@@ -1919,7 +1955,7 @@ void BaselineCompiler::VisitJumpLoop() {
   int loop_depth = iterator().GetImmediateOperand(1);
   __ CompareByte(osr_level, loop_depth);
   __ JumpIf(Condition::kUnsignedLessThanEqual, &osr_not_armed);
-  CallBuiltin(Builtins::kBaselineOnStackReplacement);
+  CallBuiltin<Builtins::kBaselineOnStackReplacement>();
   __ RecordComment("]");
 
   __ Bind(&osr_not_armed);
@@ -1972,16 +2008,14 @@ void BaselineCompiler::VisitJumpIfToBooleanFalseConstant() {
 
 void BaselineCompiler::VisitJumpIfToBooleanTrue() {
   Label dont_jump;
-  JumpIfToBoolean(false, kInterpreterAccumulatorRegister, &dont_jump,
-                  Label::kNear);
+  JumpIfToBoolean(false, &dont_jump, Label::kNear);
   UpdateInterruptBudgetAndDoInterpreterJump();
   __ Bind(&dont_jump);
 }
 
 void BaselineCompiler::VisitJumpIfToBooleanFalse() {
   Label dont_jump;
-  JumpIfToBoolean(true, kInterpreterAccumulatorRegister, &dont_jump,
-                  Label::kNear);
+  JumpIfToBoolean(true, &dont_jump, Label::kNear);
   UpdateInterruptBudgetAndDoInterpreterJump();
   __ Bind(&dont_jump);
 }
@@ -2057,13 +2091,13 @@ void BaselineCompiler::VisitSwitchOnSmiNoFeedback() {
 }
 
 void BaselineCompiler::VisitForInEnumerate() {
-  CallBuiltin(Builtins::kForInEnumerate, RegisterOperand(0));
+  CallBuiltin<Builtins::kForInEnumerate>(RegisterOperand(0));
 }
 
 void BaselineCompiler::VisitForInPrepare() {
   StoreRegister(0, kInterpreterAccumulatorRegister);
-  CallBuiltin(Builtins::kForInPrepare, kInterpreterAccumulatorRegister,
-              IndexAsTagged(1), FeedbackVector());
+  CallBuiltin<Builtins::kForInPrepare>(kInterpreterAccumulatorRegister,
+                                       IndexAsTagged(1), FeedbackVector());
   interpreter::Register first = iterator().GetRegisterOperand(0);
   interpreter::Register second(first.index() + 1);
   interpreter::Register third(first.index() + 2);
@@ -2085,13 +2119,12 @@ void BaselineCompiler::VisitForInContinue() {
 void BaselineCompiler::VisitForInNext() {
   interpreter::Register cache_type, cache_array;
   std::tie(cache_type, cache_array) = iterator().GetRegisterPairOperand(2);
-  CallBuiltin(Builtins::kForInNext,
-              Index(3),            // vector slot
-              RegisterOperand(0),  // object
-              cache_array,         // cache array
-              cache_type,          // cache type
-              RegisterOperand(1),  // index
-              FeedbackVector());   // feedback vector
+  CallBuiltin<Builtins::kForInNext>(Index(3),            // vector slot
+                                    RegisterOperand(0),  // object
+                                    cache_array,         // cache array
+                                    cache_type,          // cache type
+                                    RegisterOperand(1),  // index
+                                    FeedbackVector());   // feedback vector
 }
 
 void BaselineCompiler::VisitForInStep() {
@@ -2131,8 +2164,8 @@ void BaselineCompiler::VisitReturn() {
   int parameter_count_without_receiver =
       parameter_count - 1;  // Exclude the receiver to simplify the
                             // computation. We'll account for it at the end.
-  TailCallBuiltin(Builtins::kBaselineLeaveFrame,
-                  parameter_count_without_receiver, -profiling_weight);
+  TailCallBuiltin<Builtins::kBaselineLeaveFrame>(
+      parameter_count_without_receiver, -profiling_weight);
   __ RecordComment("]");
 }
 
@@ -2235,10 +2268,11 @@ void BaselineCompiler::VisitSuspendGenerator() {
 
     int bytecode_offset =
         BytecodeArray::kHeaderSize + iterator().current_offset();
-    CallBuiltin(Builtins::kSuspendGeneratorBaseline, generator_object,
-                static_cast<int>(Uint(3)),  // suspend_id
-                bytecode_offset,
-                static_cast<int>(RegisterCount(2)));  // register_count
+    CallBuiltin<Builtins::kSuspendGeneratorBaseline>(
+        generator_object,
+        static_cast<int>(Uint(3)),  // suspend_id
+        bytecode_offset,
+        static_cast<int>(RegisterCount(2)));  // register_count
   }
   VisitReturn();
 }
@@ -2248,26 +2282,27 @@ void BaselineCompiler::VisitResumeGenerator() {
   BaselineAssembler::ScratchRegisterScope scratch_scope(&basm_);
   Register generator_object = scratch_scope.AcquireScratch();
   LoadRegister(generator_object, 0);
-  CallBuiltin(Builtins::kResumeGeneratorBaseline, generator_object,
-              static_cast<int>(RegisterCount(2)));  // register_count
+  CallBuiltin<Builtins::kResumeGeneratorBaseline>(
+      generator_object,
+      static_cast<int>(RegisterCount(2)));  // register_count
 }
 
 void BaselineCompiler::VisitGetIterator() {
-  CallBuiltin(Builtins::kGetIteratorBaseline,
-              RegisterOperand(0),  // receiver
-              IndexAsTagged(1),    // load_slot
-              IndexAsTagged(2));   // call_slot
+  CallBuiltin<Builtins::kGetIteratorBaseline>(RegisterOperand(0),  // receiver
+                                              IndexAsTagged(1),    // load_slot
+                                              IndexAsTagged(2));   // call_slot
 }
 
 void BaselineCompiler::VisitDebugger() {
   SaveAccumulatorScope accumulator_scope(&basm_);
-  CallBuiltin(Builtins::kHandleDebuggerStatement);
+  CallRuntime(Runtime::kHandleDebuggerStatement);
 }
 
 void BaselineCompiler::VisitIncBlockCounter() {
   SaveAccumulatorScope accumulator_scope(&basm_);
-  CallBuiltin(Builtins::kIncBlockCounter, __ FunctionOperand(),
-              IndexAsSmi(0));  // coverage array slot
+  CallBuiltin<Builtins::kIncBlockCounter>(
+      __ FunctionOperand(),
+      IndexAsSmi(0));  // coverage array slot
 }
 
 void BaselineCompiler::VisitAbort() {
diff --git a/chromium/v8/src/baseline/baseline-compiler.h b/chromium/v8/src/baseline/baseline-compiler.h
index dbb2f64f6c5..c86d9417e8a 100644
--- a/chromium/v8/src/baseline/baseline-compiler.h
+++ b/chromium/v8/src/baseline/baseline-compiler.h
@@ -8,7 +8,7 @@
 // TODO(v8:11421): Remove #if once baseline compiler is ported to other
 // architectures.
 #if V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || \
-    V8_TARGET_ARCH_ARM
+    V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_RISCV64
 
 #include "src/base/logging.h"
 #include "src/base/threaded-list.h"
@@ -39,8 +39,10 @@ class BytecodeOffsetTableBuilder {
     previous_pc_ = pc_offset;
   }
 
-  template <typename LocalIsolate>
-  Handle<ByteArray> ToBytecodeOffsetTable(LocalIsolate* isolate);
+  template <typename IsolateT>
+  Handle<ByteArray> ToBytecodeOffsetTable(IsolateT* isolate);
+
+  void Reserve(size_t size) { bytes_.reserve(size); }
 
  private:
   size_t previous_pc_ = 0;
@@ -121,31 +123,21 @@ class BaselineCompiler {
   void SelectBooleanConstant(
       Register output, std::function<void(Label*, Label::Distance)> jump_func);
 
-  // Returns ToBoolean result into kInterpreterAccumulatorRegister.
-  void JumpIfToBoolean(bool do_jump_if_true, Register reg, Label* label,
+  // Jumps based on calling ToBoolean on kInterpreterAccumulatorRegister.
+  void JumpIfToBoolean(bool do_jump_if_true, Label* label,
                        Label::Distance distance = Label::kFar);
 
   // Call helpers.
-  template <typename... Args>
-  void CallBuiltin(Builtins::Name builtin, Args... args);
+  template <Builtins::Name kBuiltin, typename... Args>
+  void CallBuiltin(Args... args);
   template <typename... Args>
   void CallRuntime(Runtime::FunctionId function, Args... args);
 
-  template <typename... Args>
-  void TailCallBuiltin(Builtins::Name builtin, Args... args);
+  template <Builtins::Name kBuiltin, typename... Args>
+  void TailCallBuiltin(Args... args);
 
-  void BuildBinop(
-      Builtins::Name builtin_name, bool fast_path = false,
-      bool check_overflow = false,
-      std::function<void(Register, Register)> instruction = [](Register,
-                                                               Register) {});
-  void BuildUnop(Builtins::Name builtin_name);
-  void BuildCompare(Builtins::Name builtin_name);
-  void BuildBinopWithConstant(Builtins::Name builtin_name);
-
-  template <typename... Args>
-  void BuildCall(ConvertReceiverMode mode, uint32_t slot, uint32_t arg_count,
-                 Args... args);
+  template <ConvertReceiverMode kMode, typename... Args>
+  void BuildCall(uint32_t slot, uint32_t arg_count, Args... args);
 
 #ifdef V8_TRACE_UNOPTIMIZED
   void TraceBytecode(Runtime::FunctionId function_id);
diff --git a/chromium/v8/src/baseline/baseline-osr-inl.h b/chromium/v8/src/baseline/baseline-osr-inl.h
new file mode 100644
index 00000000000..d37007f9cf6
--- /dev/null
+++ b/chromium/v8/src/baseline/baseline-osr-inl.h
@@ -0,0 +1,38 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+#ifndef V8_BASELINE_BASELINE_OSR_INL_H_
+#define V8_BASELINE_BASELINE_OSR_INL_H_
+
+#include "src/execution/frames.h"
+#include "src/execution/isolate-inl.h"
+
+namespace v8 {
+namespace internal {
+
+inline void OSRInterpreterFrameToBaseline(Isolate* isolate,
+                                          Handle<JSFunction> function,
+                                          UnoptimizedFrame* frame) {
+  IsCompiledScope is_compiled_scope(
+      function->shared().is_compiled_scope(isolate));
+  if (Compiler::CompileBaseline(isolate, function, Compiler::CLEAR_EXCEPTION,
+                                &is_compiled_scope)) {
+    if (V8_LIKELY(FLAG_use_osr)) {
+      DCHECK_NOT_NULL(frame);
+      if (FLAG_trace_osr) {
+        CodeTracer::Scope scope(isolate->GetCodeTracer());
+        PrintF(scope.file(),
+               "[OSR - Entry at OSR bytecode offset %d into baseline code]\n",
+               frame->GetBytecodeOffset());
+      }
+      frame->GetBytecodeArray().set_osr_loop_nesting_level(
+          AbstractCode::kMaxLoopNestingMarker);
+    }
+  }
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_BASELINE_BASELINE_OSR_INL_H_
diff --git a/chromium/v8/src/baseline/baseline.cc b/chromium/v8/src/baseline/baseline.cc
index b5355660f94..c7cc130c5ed 100644
--- a/chromium/v8/src/baseline/baseline.cc
+++ b/chromium/v8/src/baseline/baseline.cc
@@ -5,14 +5,16 @@
 #include "src/baseline/baseline.h"
 
 #include "src/handles/maybe-handles.h"
+#include "src/objects/shared-function-info.h"
 
 // TODO(v8:11421): Remove #if once baseline compiler is ported to other
 // architectures.
 #if V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || \
-    V8_TARGET_ARCH_ARM
+    V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_RISCV64
 
 #include "src/baseline/baseline-assembler-inl.h"
 #include "src/baseline/baseline-compiler.h"
+#include "src/debug/debug.h"
 #include "src/heap/factory-inl.h"
 #include "src/logging/counters.h"
 #include "src/objects/script-inl.h"
@@ -21,10 +23,36 @@
 namespace v8 {
 namespace internal {
 
+bool CanCompileWithBaseline(Isolate* isolate, SharedFunctionInfo shared) {
+  DisallowGarbageCollection no_gc;
+
+  if (!FLAG_sparkplug) return false;
+
+  // Check that short builtin calls are enabled if needed.
+  if (FLAG_sparkplug_needs_short_builtins &&
+      !isolate->is_short_builtin_calls_enabled()) {
+    return false;
+  }
+
+  // Check if we actually have bytecode.
+  if (!shared.HasBytecodeArray()) return false;
+
+  // Do not optimize when debugger needs to hook into every call.
+  if (isolate->debug()->needs_check_on_function_call()) return false;
+
+  // Functions with breakpoints have to stay interpreted.
+  if (shared.HasBreakInfo()) return false;
+
+  // Do not baseline compile if sparkplug is disabled or function doesn't pass
+  // sparkplug_filter.
+  if (!shared.PassesFilter(FLAG_sparkplug_filter)) return false;
+
+  return true;
+}
+
 MaybeHandle<Code> GenerateBaselineCode(Isolate* isolate,
                                        Handle<SharedFunctionInfo> shared) {
-  RuntimeCallTimerScope runtimeTimer(isolate,
-                                     RuntimeCallCounterId::kCompileBaseline);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kCompileBaseline);
   baseline::BaselineCompiler compiler(
       isolate, shared, handle(shared->GetBytecodeArray(isolate), isolate));
 
@@ -48,6 +76,10 @@ void EmitReturnBaseline(MacroAssembler* masm) {
 namespace v8 {
 namespace internal {
 
+bool CanCompileWithBaseline(Isolate* isolate, SharedFunctionInfo shared) {
+  return false;
+}
+
 MaybeHandle<Code> GenerateBaselineCode(Isolate* isolate,
                                        Handle<SharedFunctionInfo> shared) {
   UNREACHABLE();
diff --git a/chromium/v8/src/baseline/baseline.h b/chromium/v8/src/baseline/baseline.h
index 2dba2d9674b..10a6e25e4fb 100644
--- a/chromium/v8/src/baseline/baseline.h
+++ b/chromium/v8/src/baseline/baseline.h
@@ -14,6 +14,8 @@ class Code;
 class SharedFunctionInfo;
 class MacroAssembler;
 
+bool CanCompileWithBaseline(Isolate* isolate, SharedFunctionInfo shared);
+
 MaybeHandle<Code> GenerateBaselineCode(Isolate* isolate,
                                        Handle<SharedFunctionInfo> shared);
 
diff --git a/chromium/v8/src/baseline/ia32/baseline-assembler-ia32-inl.h b/chromium/v8/src/baseline/ia32/baseline-assembler-ia32-inl.h
index 2cd34aef710..8babb4a5b7b 100644
--- a/chromium/v8/src/baseline/ia32/baseline-assembler-ia32-inl.h
+++ b/chromium/v8/src/baseline/ia32/baseline-assembler-ia32-inl.h
@@ -122,13 +122,13 @@ void BaselineAssembler::JumpIfNotSmi(Register value, Label* target,
 void BaselineAssembler::CallBuiltin(Builtins::Name builtin) {
   __ RecordCommentForOffHeapTrampoline(builtin);
   __ Call(__ EntryFromBuiltinIndexAsOperand(builtin));
-  if (FLAG_code_comments) __ RecordComment("]");
+  __ RecordComment("]");
 }
 
 void BaselineAssembler::TailCallBuiltin(Builtins::Name builtin) {
   __ RecordCommentForOffHeapTrampoline(builtin);
   __ jmp(__ EntryFromBuiltinIndexAsOperand(builtin));
-  if (FLAG_code_comments) __ RecordComment("]");
+  __ RecordComment("]");
 }
 
 void BaselineAssembler::Test(Register value, int mask) {
@@ -147,7 +147,7 @@ void BaselineAssembler::CmpObjectType(Register object,
 }
 void BaselineAssembler::CmpInstanceType(Register map,
                                         InstanceType instance_type) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ movd(xmm0, eax);
     __ AssertNotSmi(map);
     __ CmpObjectType(map, MAP_TYPE, eax);
@@ -320,7 +320,7 @@ void BaselineAssembler::StoreTaggedFieldWithWriteBarrier(Register target,
   Register scratch = scratch_scope.AcquireScratch();
   DCHECK(!AreAliased(scratch, target, value));
   __ mov(FieldOperand(target, offset), value);
-  __ RecordWriteField(target, offset, value, scratch, kDontSaveFPRegs);
+  __ RecordWriteField(target, offset, value, scratch, SaveFPRegsMode::kIgnore);
 }
 void BaselineAssembler::StoreTaggedFieldNoWriteBarrier(Register target,
                                                        int offset,
diff --git a/chromium/v8/src/baseline/ia32/baseline-compiler-ia32-inl.h b/chromium/v8/src/baseline/ia32/baseline-compiler-ia32-inl.h
index 733c05fe185..4d09f536653 100644
--- a/chromium/v8/src/baseline/ia32/baseline-compiler-ia32-inl.h
+++ b/chromium/v8/src/baseline/ia32/baseline-compiler-ia32-inl.h
@@ -18,9 +18,9 @@ namespace baseline {
 void BaselineCompiler::Prologue() {
   DCHECK_EQ(kJSFunctionRegister, kJavaScriptCallTargetRegister);
   int max_frame_size = bytecode_->frame_size() + max_call_args_;
-  CallBuiltin(Builtins::kBaselineOutOfLinePrologue, kContextRegister,
-              kJSFunctionRegister, kJavaScriptCallArgCountRegister,
-              max_frame_size, kJavaScriptCallNewTargetRegister, bytecode_);
+  CallBuiltin<Builtins::kBaselineOutOfLinePrologue>(
+      kContextRegister, kJSFunctionRegister, kJavaScriptCallArgCountRegister,
+      max_frame_size, kJavaScriptCallNewTargetRegister, bytecode_);
 
   PrologueFillFrame();
 }
diff --git a/chromium/v8/src/baseline/riscv64/baseline-assembler-riscv64-inl.h b/chromium/v8/src/baseline/riscv64/baseline-assembler-riscv64-inl.h
new file mode 100644
index 00000000000..e0667d3472b
--- /dev/null
+++ b/chromium/v8/src/baseline/riscv64/baseline-assembler-riscv64-inl.h
@@ -0,0 +1,615 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_BASELINE_RISCV64_BASELINE_ASSEMBLER_RISCV64_INL_H_
+#define V8_BASELINE_RISCV64_BASELINE_ASSEMBLER_RISCV64_INL_H_
+
+#include "src/baseline/baseline-assembler.h"
+#include "src/codegen/assembler-inl.h"
+#include "src/codegen/interface-descriptors.h"
+namespace v8 {
+namespace internal {
+namespace baseline {
+
+constexpr Register kTestReg = t0;
+class BaselineAssembler::ScratchRegisterScope {
+ public:
+  explicit ScratchRegisterScope(BaselineAssembler* assembler)
+      : assembler_(assembler),
+        prev_scope_(assembler->scratch_register_scope_),
+        wrapped_scope_(assembler->masm()) {
+    if (!assembler_->scratch_register_scope_) {
+      // If we haven't opened a scratch scope yet, for the first one add a
+      // couple of extra registers.
+      wrapped_scope_.Include(t2, t4);
+    }
+    assembler_->scratch_register_scope_ = this;
+  }
+  ~ScratchRegisterScope() { assembler_->scratch_register_scope_ = prev_scope_; }
+
+  Register AcquireScratch() { return wrapped_scope_.Acquire(); }
+
+ private:
+  BaselineAssembler* assembler_;
+  ScratchRegisterScope* prev_scope_;
+  UseScratchRegisterScope wrapped_scope_;
+};
+
+enum class Condition : uint32_t {
+  kEqual = eq,
+  kNotEqual = ne,
+
+  kLessThan = lt,
+  kGreaterThan = gt,
+  kLessThanEqual = le,
+  kGreaterThanEqual = ge,
+
+  kUnsignedLessThan = Uless,
+  kUnsignedGreaterThan = Ugreater,
+  kUnsignedLessThanEqual = Uless_equal,
+  kUnsignedGreaterThanEqual = Ugreater_equal,
+
+  kOverflow = overflow,
+  kNoOverflow = no_overflow,
+
+  kZero = eq,
+  kNotZero = ne,
+};
+
+inline internal::Condition AsMasmCondition(Condition cond) {
+  return static_cast<internal::Condition>(cond);
+}
+
+namespace detail {
+
+#ifdef DEBUG
+inline bool Clobbers(Register target, MemOperand op) {
+  return op.is_reg() && op.rm() == target;
+}
+#endif
+
+}  // namespace detail
+
+#define __ masm_->
+
+MemOperand BaselineAssembler::RegisterFrameOperand(
+    interpreter::Register interpreter_register) {
+  return MemOperand(fp, interpreter_register.ToOperand() * kSystemPointerSize);
+}
+MemOperand BaselineAssembler::FeedbackVectorOperand() {
+  return MemOperand(fp, BaselineFrameConstants::kFeedbackVectorFromFp);
+}
+
+void BaselineAssembler::Bind(Label* label) { __ bind(label); }
+
+void BaselineAssembler::BindWithoutJumpTarget(Label* label) { __ bind(label); }
+
+void BaselineAssembler::JumpTarget() {
+  // Nop
+}
+
+void BaselineAssembler::Jump(Label* target, Label::Distance distance) {
+  __ jmp(target);
+}
+void BaselineAssembler::JumpIf(Condition cc, Label* target, Label::Distance) {
+  __ Branch(target, AsMasmCondition(cc), kTestReg, Operand((int64_t)0));
+}
+void BaselineAssembler::JumpIfRoot(Register value, RootIndex index,
+                                   Label* target, Label::Distance) {
+  __ JumpIfRoot(value, index, target);
+}
+void BaselineAssembler::JumpIfNotRoot(Register value, RootIndex index,
+                                      Label* target, Label::Distance) {
+  __ JumpIfNotRoot(value, index, target);
+}
+void BaselineAssembler::JumpIfSmi(Register value, Label* target,
+                                  Label::Distance) {
+  __ JumpIfSmi(value, target);
+}
+void BaselineAssembler::JumpIfNotSmi(Register value, Label* target,
+                                     Label::Distance) {
+  __ JumpIfSmi(value, target);
+}
+
+void BaselineAssembler::CallBuiltin(Builtins::Name builtin) {
+  if (masm()->options().short_builtin_calls) {
+    __ CallBuiltin(builtin);
+  } else {
+    __ RecordCommentForOffHeapTrampoline(builtin);
+    Register temp = t6;
+    __ LoadEntryFromBuiltinIndex(builtin, temp);
+    __ Call(temp);
+    __ RecordComment("]");
+  }
+}
+
+void BaselineAssembler::TailCallBuiltin(Builtins::Name builtin) {
+  if (masm()->options().short_builtin_calls) {
+    // Generate pc-relative jump.
+    __ TailCallBuiltin(builtin);
+  } else {
+    __ RecordCommentForOffHeapTrampoline(builtin);
+    // t6 be used for function call in RISCV64
+    // For example 'jalr t6' or 'jal t6'
+    Register temp = t6;
+    __ LoadEntryFromBuiltinIndex(builtin, temp);
+    __ Jump(temp);
+    __ RecordComment("]");
+  }
+}
+
+void BaselineAssembler::Test(Register value, int mask) {
+  __ And(kTestReg, value, Operand(mask));
+}
+
+void BaselineAssembler::CmpObjectType(Register object,
+                                      InstanceType instance_type,
+                                      Register map) {
+  ScratchRegisterScope temps(this);
+  Register type = temps.AcquireScratch();
+  __ GetObjectType(object, map, type);
+  __ Sub64(kTestReg, type, Operand(instance_type));
+}
+void BaselineAssembler::CmpInstanceType(Register value,
+                                        InstanceType instance_type) {
+  ScratchRegisterScope temps(this);
+  Register type = temps.AcquireScratch();
+  __ Ld(type, FieldMemOperand(value, Map::kInstanceTypeOffset));
+  __ Sub64(kTestReg, type, Operand(instance_type));
+}
+
+void BaselineAssembler::Cmp(Register value, Smi smi) {
+  ScratchRegisterScope temps(this);
+  Register temp = temps.AcquireScratch();
+  __ li(temp, Operand(smi));
+  __ SmiUntag(temp);
+  __ Sub64(kTestReg, value, temp);
+}
+void BaselineAssembler::ComparePointer(Register value, MemOperand operand) {
+  ScratchRegisterScope temps(this);
+  Register temp = temps.AcquireScratch();
+  __ Ld(temp, operand);
+  __ Sub64(kTestReg, value, temp);
+}
+
+void BaselineAssembler::SmiCompare(Register lhs, Register rhs) {
+  __ AssertSmi(lhs);
+  __ AssertSmi(rhs);
+  if (COMPRESS_POINTERS_BOOL) {
+    __ Sub32(kTestReg, lhs, rhs);
+  } else {
+    __ Sub64(kTestReg, lhs, rhs);
+  }
+}
+void BaselineAssembler::CompareTagged(Register value, MemOperand operand) {
+  ScratchRegisterScope temps(this);
+  Register tmp = temps.AcquireScratch();
+  __ Ld(tmp, operand);
+  if (COMPRESS_POINTERS_BOOL) {
+    __ Sub32(kTestReg, value, tmp);
+  } else {
+    __ Sub64(kTestReg, value, tmp);
+  }
+}
+void BaselineAssembler::CompareTagged(MemOperand operand, Register value) {
+  ScratchRegisterScope temps(this);
+  Register tmp = temps.AcquireScratch();
+  __ Ld(tmp, operand);
+  if (COMPRESS_POINTERS_BOOL) {
+    __ Sub32(kTestReg, tmp, value);
+  } else {
+    __ Sub64(kTestReg, tmp, value);
+  }
+}
+
+void BaselineAssembler::CompareByte(Register value, int32_t byte) {
+  __ Sub64(kTestReg, value, Operand(byte));
+}
+
+void BaselineAssembler::Move(interpreter::Register output, Register source) {
+  Move(RegisterFrameOperand(output), source);
+}
+void BaselineAssembler::Move(Register output, TaggedIndex value) {
+  __ li(output, Operand(value.ptr()));
+}
+void BaselineAssembler::Move(MemOperand output, Register source) {
+  __ Sd(source, output);
+}
+void BaselineAssembler::Move(Register output, ExternalReference reference) {
+  __ li(output, Operand(reference));
+}
+void BaselineAssembler::Move(Register output, Handle<HeapObject> value) {
+  __ li(output, Operand(value));
+}
+void BaselineAssembler::Move(Register output, int32_t value) {
+  __ li(output, Operand(value));
+}
+void BaselineAssembler::MoveMaybeSmi(Register output, Register source) {
+  __ Move(output, source);
+}
+void BaselineAssembler::MoveSmi(Register output, Register source) {
+  __ Move(output, source);
+}
+
+namespace detail {
+
+template <typename Arg>
+inline Register ToRegister(BaselineAssembler* basm,
+                           BaselineAssembler::ScratchRegisterScope* scope,
+                           Arg arg) {
+  Register reg = scope->AcquireScratch();
+  basm->Move(reg, arg);
+  return reg;
+}
+inline Register ToRegister(BaselineAssembler* basm,
+                           BaselineAssembler::ScratchRegisterScope* scope,
+                           Register reg) {
+  return reg;
+}
+
+template <typename... Args>
+struct CountPushHelper;
+template <>
+struct CountPushHelper<> {
+  static int Count() { return 0; }
+};
+template <typename Arg, typename... Args>
+struct CountPushHelper<Arg, Args...> {
+  static int Count(Arg arg, Args... args) {
+    return 1 + CountPushHelper<Args...>::Count(args...);
+  }
+};
+template <typename... Args>
+struct CountPushHelper<interpreter::RegisterList, Args...> {
+  static int Count(interpreter::RegisterList list, Args... args) {
+    return list.register_count() + CountPushHelper<Args...>::Count(args...);
+  }
+};
+
+template <typename... Args>
+struct PushAllHelper;
+template <typename... Args>
+void PushAll(BaselineAssembler* basm, Args... args) {
+  PushAllHelper<Args...>::Push(basm, args...);
+}
+template <typename... Args>
+void PushAllReverse(BaselineAssembler* basm, Args... args) {
+  PushAllHelper<Args...>::PushReverse(basm, args...);
+}
+
+template <>
+struct PushAllHelper<> {
+  static void Push(BaselineAssembler* basm) {}
+  static void PushReverse(BaselineAssembler* basm) {}
+};
+
+inline void PushSingle(MacroAssembler* masm, RootIndex source) {
+  masm->PushRoot(source);
+}
+inline void PushSingle(MacroAssembler* masm, Register reg) { masm->Push(reg); }
+
+inline void PushSingle(MacroAssembler* masm, Smi value) { masm->Push(value); }
+inline void PushSingle(MacroAssembler* masm, Handle<HeapObject> object) {
+  masm->Push(object);
+}
+inline void PushSingle(MacroAssembler* masm, int32_t immediate) {
+  masm->li(kScratchReg, (int64_t)(immediate));
+  PushSingle(masm, kScratchReg);
+}
+
+inline void PushSingle(MacroAssembler* masm, TaggedIndex value) {
+  masm->li(kScratchReg, static_cast<int64_t>(value.ptr()));
+  PushSingle(masm, kScratchReg);
+}
+inline void PushSingle(MacroAssembler* masm, MemOperand operand) {
+  masm->Ld(kScratchReg, operand);
+  PushSingle(masm, kScratchReg);
+}
+inline void PushSingle(MacroAssembler* masm, interpreter::Register source) {
+  return PushSingle(masm, BaselineAssembler::RegisterFrameOperand(source));
+}
+
+template <typename Arg>
+struct PushAllHelper<Arg> {
+  static void Push(BaselineAssembler* basm, Arg arg) {
+    PushSingle(basm->masm(), arg);
+  }
+  static void PushReverse(BaselineAssembler* basm, Arg arg) {
+    // Push the padding register to round up the amount of values pushed.
+    return Push(basm, arg);
+  }
+};
+template <typename Arg1, typename Arg2, typename... Args>
+struct PushAllHelper<Arg1, Arg2, Args...> {
+  static void Push(BaselineAssembler* basm, Arg1 arg1, Arg2 arg2,
+                   Args... args) {
+    {
+      BaselineAssembler::ScratchRegisterScope scope(basm);
+      basm->masm()->Push(ToRegister(basm, &scope, arg1),
+                         ToRegister(basm, &scope, arg2));
+    }
+    PushAll(basm, args...);
+  }
+  static void PushReverse(BaselineAssembler* basm, Arg1 arg1, Arg2 arg2,
+                          Args... args) {
+    PushAllReverse(basm, args...);
+    {
+      BaselineAssembler::ScratchRegisterScope scope(basm);
+      basm->masm()->Push(ToRegister(basm, &scope, arg2),
+                         ToRegister(basm, &scope, arg1));
+    }
+  }
+};
+// Currently RegisterLists are always be the last argument, so we don't
+// specialize for the case where they're not. We do still specialise for the
+// aligned and unaligned cases.
+template <typename Arg>
+struct PushAllHelper<Arg, interpreter::RegisterList> {
+  static void Push(BaselineAssembler* basm, Arg arg,
+                   interpreter::RegisterList list) {
+    DCHECK_EQ(list.register_count() % 2, 1);
+    PushAll(basm, arg, list[0], list.PopLeft());
+  }
+  static void PushReverse(BaselineAssembler* basm, Arg arg,
+                          interpreter::RegisterList list) {
+    if (list.register_count() == 0) {
+      PushAllReverse(basm, arg);
+    } else {
+      PushAllReverse(basm, arg, list[0], list.PopLeft());
+    }
+  }
+};
+template <>
+struct PushAllHelper<interpreter::RegisterList> {
+  static void Push(BaselineAssembler* basm, interpreter::RegisterList list) {
+    DCHECK_EQ(list.register_count() % 2, 0);
+    for (int reg_index = 0; reg_index < list.register_count(); reg_index += 2) {
+      PushAll(basm, list[reg_index], list[reg_index + 1]);
+    }
+  }
+  static void PushReverse(BaselineAssembler* basm,
+                          interpreter::RegisterList list) {
+    int reg_index = list.register_count() - 1;
+    if (reg_index % 2 == 0) {
+      // Push the padding register to round up the amount of values pushed.
+      PushAllReverse(basm, list[reg_index]);
+      reg_index--;
+    }
+    for (; reg_index >= 1; reg_index -= 2) {
+      PushAllReverse(basm, list[reg_index - 1], list[reg_index]);
+    }
+  }
+};
+
+template <typename... T>
+struct PopAllHelper;
+template <>
+struct PopAllHelper<> {
+  static void Pop(BaselineAssembler* basm) {}
+};
+template <>
+struct PopAllHelper<Register> {
+  static void Pop(BaselineAssembler* basm, Register reg) {
+    basm->masm()->Pop(reg);
+  }
+};
+template <typename... T>
+struct PopAllHelper<Register, Register, T...> {
+  static void Pop(BaselineAssembler* basm, Register reg1, Register reg2,
+                  T... tail) {
+    basm->masm()->Pop(reg1, reg2);
+    PopAllHelper<T...>::Pop(basm, tail...);
+  }
+};
+
+}  // namespace detail
+
+template <typename... T>
+int BaselineAssembler::Push(T... vals) {
+  // We have to count the pushes first, to decide whether to add padding before
+  // the first push.
+  int push_count = detail::CountPushHelper<T...>::Count(vals...);
+  if (push_count % 2 == 0) {
+    detail::PushAll(this, vals...);
+  } else {
+    detail::PushAll(this, vals...);
+  }
+  return push_count;
+}
+
+template <typename... T>
+void BaselineAssembler::PushReverse(T... vals) {
+  detail::PushAllReverse(this, vals...);
+}
+
+template <typename... T>
+void BaselineAssembler::Pop(T... registers) {
+  detail::PopAllHelper<T...>::Pop(this, registers...);
+}
+
+void BaselineAssembler::LoadTaggedPointerField(Register output, Register source,
+                                               int offset) {
+  // FIXME(riscv64): riscv64 don't implement pointer compressed
+  // __ LoadTaggedPointerField(output, FieldMemOperand(source, offset));
+  __ Ld(output, FieldMemOperand(source, offset));
+}
+void BaselineAssembler::LoadTaggedSignedField(Register output, Register source,
+                                              int offset) {
+  // FIXME(riscv64): riscv64 don't implement pointer compressed
+  __ Ld(output, FieldMemOperand(source, offset));
+}
+void BaselineAssembler::LoadTaggedAnyField(Register output, Register source,
+                                           int offset) {
+  // FIXME(riscv64): riscv64 don't implement pointer compressed
+  __ Ld(output, FieldMemOperand(source, offset));
+}
+void BaselineAssembler::LoadByteField(Register output, Register source,
+                                      int offset) {
+  __ Ld(output, FieldMemOperand(source, offset));
+}
+void BaselineAssembler::StoreTaggedSignedField(Register target, int offset,
+                                               Smi value) {
+  ScratchRegisterScope temps(this);
+  Register tmp = temps.AcquireScratch();
+  __ li(tmp, Operand(value));
+  // FIXME(riscv64): riscv64 don't implement pointer compressed
+  __ Sd(tmp, FieldMemOperand(target, offset));
+}
+void BaselineAssembler::StoreTaggedFieldWithWriteBarrier(Register target,
+                                                         int offset,
+                                                         Register value) {
+  // FIXME(riscv64): riscv64 don't implement pointer compressed
+  __ Sd(value, FieldMemOperand(target, offset));
+  ScratchRegisterScope temps(this);
+  Register tmp = temps.AcquireScratch();
+  __ RecordWriteField(target, offset, value, tmp, kRAHasNotBeenSaved,
+                      SaveFPRegsMode::kIgnore);
+}
+void BaselineAssembler::StoreTaggedFieldNoWriteBarrier(Register target,
+                                                       int offset,
+                                                       Register value) {
+  // FIXME(riscv64): riscv64 don't implement pointer compressed
+  __ Sd(value, FieldMemOperand(target, offset));
+}
+
+void BaselineAssembler::AddToInterruptBudget(int32_t weight) {
+  ScratchRegisterScope scratch_scope(this);
+  Register feedback_cell = scratch_scope.AcquireScratch();
+  LoadFunction(feedback_cell);
+  LoadTaggedPointerField(feedback_cell, feedback_cell,
+                         JSFunction::kFeedbackCellOffset);
+
+  Register interrupt_budget = scratch_scope.AcquireScratch();
+  __ Ld(interrupt_budget,
+        FieldMemOperand(feedback_cell, FeedbackCell::kInterruptBudgetOffset));
+  // Remember to set flags as part of the add!
+  __ Add64(interrupt_budget, interrupt_budget, weight);
+  __ Sd(interrupt_budget,
+        FieldMemOperand(feedback_cell, FeedbackCell::kInterruptBudgetOffset));
+}
+
+void BaselineAssembler::AddToInterruptBudget(Register weight) {
+  ScratchRegisterScope scratch_scope(this);
+  Register feedback_cell = scratch_scope.AcquireScratch();
+  LoadFunction(feedback_cell);
+  LoadTaggedPointerField(feedback_cell, feedback_cell,
+                         JSFunction::kFeedbackCellOffset);
+
+  Register interrupt_budget = scratch_scope.AcquireScratch();
+  __ Ld(interrupt_budget,
+        FieldMemOperand(feedback_cell, FeedbackCell::kInterruptBudgetOffset));
+  // Remember to set flags as part of the add!
+  __ Add64(interrupt_budget, interrupt_budget, weight);
+  __ Sd(interrupt_budget,
+        FieldMemOperand(feedback_cell, FeedbackCell::kInterruptBudgetOffset));
+}
+
+void BaselineAssembler::AddSmi(Register lhs, Smi rhs) {
+  if (SmiValuesAre31Bits()) {
+    __ Add32(lhs, lhs, Operand(rhs));
+  } else {
+    __ Add64(lhs, lhs, Operand(rhs));
+  }
+}
+
+void BaselineAssembler::Switch(Register reg, int case_value_base,
+                               Label** labels, int num_labels) {
+  Label fallthrough;
+  if (case_value_base > 0) {
+    __ Sub64(reg, reg, Operand(case_value_base));
+  }
+
+  // Mostly copied from code-generator-riscv64.cc
+  ScratchRegisterScope scope(this);
+  Register temp = scope.AcquireScratch();
+  Label table;
+  __ Branch(&fallthrough, AsMasmCondition(Condition::kUnsignedGreaterThanEqual),
+            reg, Operand(int64_t(num_labels)));
+  int64_t imm64;
+  imm64 = __ branch_long_offset(&table);
+  DCHECK(is_int32(imm64));
+  int32_t Hi20 = (((int32_t)imm64 + 0x800) >> 12);
+  int32_t Lo12 = (int32_t)imm64 << 20 >> 20;
+  __ auipc(temp, Hi20);  // Read PC + Hi20 into t6
+  __ lui(temp, Lo12);    // jump PC + Hi20 + Lo12
+
+  int entry_size_log2 = 2;
+  Register temp2 = scope.AcquireScratch();
+  __ CalcScaledAddress(temp2, temp, reg, entry_size_log2);
+  __ Jump(temp);
+  {
+    TurboAssembler::BlockTrampolinePoolScope(masm());
+    __ BlockTrampolinePoolFor(num_labels * kInstrSize);
+    __ bind(&table);
+    for (int i = 0; i < num_labels; ++i) {
+      __ Branch(labels[i]);
+    }
+    DCHECK_EQ(num_labels * kInstrSize, __ InstructionsGeneratedSince(&table));
+    __ bind(&fallthrough);
+  }
+}
+
+#undef __
+
+#define __ basm.
+
+void BaselineAssembler::EmitReturn(MacroAssembler* masm) {
+  BaselineAssembler basm(masm);
+
+  Register weight = BaselineLeaveFrameDescriptor::WeightRegister();
+  Register params_size = BaselineLeaveFrameDescriptor::ParamsSizeRegister();
+
+  __ RecordComment("[ Update Interrupt Budget");
+  __ AddToInterruptBudget(weight);
+
+  // Use compare flags set by add
+  Label skip_interrupt_label;
+  __ JumpIf(Condition::kGreaterThanEqual, &skip_interrupt_label);
+  {
+    __ masm()->SmiTag(params_size);
+    __ masm()->Push(params_size, kInterpreterAccumulatorRegister);
+
+    __ LoadContext(kContextRegister);
+    __ LoadFunction(kJSFunctionRegister);
+    __ masm()->Push(kJSFunctionRegister);
+    __ CallRuntime(Runtime::kBytecodeBudgetInterruptFromBytecode, 1);
+
+    __ masm()->Pop(kInterpreterAccumulatorRegister, params_size);
+    __ masm()->SmiUntag(params_size);
+  }
+  __ RecordComment("]");
+
+  __ Bind(&skip_interrupt_label);
+
+  BaselineAssembler::ScratchRegisterScope temps(&basm);
+  Register actual_params_size = temps.AcquireScratch();
+  // Compute the size of the actual parameters + receiver (in bytes).
+  __ Move(actual_params_size,
+          MemOperand(fp, StandardFrameConstants::kArgCOffset));
+
+  // If actual is bigger than formal, then we should use it to free up the stack
+  // arguments.
+  Label corrected_args_count;
+  __ masm()->Branch(&corrected_args_count, ge, params_size,
+                    Operand(actual_params_size));
+  __ masm()->Move(params_size, actual_params_size);
+  __ Bind(&corrected_args_count);
+
+  // Leave the frame (also dropping the register file).
+  __ masm()->LeaveFrame(StackFrame::BASELINE);
+
+  // Drop receiver + arguments.
+  __ masm()->Add64(params_size, params_size, 1);  // Include the receiver.
+  __ masm()->slli(params_size, params_size, kPointerSizeLog2);
+  __ masm()->Add64(sp, sp, params_size);
+  __ masm()->Ret();
+}
+
+#undef __
+
+}  // namespace baseline
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_BASELINE_RISCV64_BASELINE_ASSEMBLER_RISCV64_INL_H_
diff --git a/chromium/v8/src/baseline/riscv64/baseline-compiler-riscv64-inl.h b/chromium/v8/src/baseline/riscv64/baseline-compiler-riscv64-inl.h
new file mode 100644
index 00000000000..98ca62e3034
--- /dev/null
+++ b/chromium/v8/src/baseline/riscv64/baseline-compiler-riscv64-inl.h
@@ -0,0 +1,112 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_BASELINE_RISCV64_BASELINE_COMPILER_RISCV64_INL_H_
+#define V8_BASELINE_RISCV64_BASELINE_COMPILER_RISCV64_INL_H_
+
+#include "src/baseline/baseline-compiler.h"
+
+namespace v8 {
+namespace internal {
+namespace baseline {
+
+#define __ basm_.
+
+void BaselineCompiler::Prologue() {
+  // Enter the frame here, since CallBuiltin will override lr.
+  __ masm()->EnterFrame(StackFrame::BASELINE);
+  DCHECK_EQ(kJSFunctionRegister, kJavaScriptCallTargetRegister);
+  int max_frame_size = bytecode_->frame_size() + max_call_args_;
+  CallBuiltin<Builtins::kBaselineOutOfLinePrologue>(
+      kContextRegister, kJSFunctionRegister, kJavaScriptCallArgCountRegister,
+      max_frame_size, kJavaScriptCallNewTargetRegister, bytecode_);
+  PrologueFillFrame();
+}
+
+void BaselineCompiler::PrologueFillFrame() {
+  __ RecordComment("[ Fill frame");
+  // Inlined register frame fill
+  interpreter::Register new_target_or_generator_register =
+      bytecode_->incoming_new_target_or_generator_register();
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
+  int register_count = bytecode_->register_count();
+  // Magic value
+  const int kLoopUnrollSize = 8;
+  const int new_target_index = new_target_or_generator_register.index();
+  const bool has_new_target = new_target_index != kMaxInt;
+  // BaselineOutOfLinePrologue already pushed one undefined.
+  register_count -= 1;
+  if (has_new_target) {
+    if (new_target_index == 0) {
+      // Oops, need to fix up that undefined that BaselineOutOfLinePrologue
+      // pushed.
+      __ masm()->Sd(kJavaScriptCallNewTargetRegister, MemOperand(sp));
+    } else {
+      DCHECK_LE(new_target_index, register_count);
+      int index = 1;
+      for (; index + 2 <= new_target_index; index += 2) {
+        __ masm()->Push(kInterpreterAccumulatorRegister,
+                        kInterpreterAccumulatorRegister);
+      }
+      if (index == new_target_index) {
+        __ masm()->Push(kJavaScriptCallNewTargetRegister,
+                        kInterpreterAccumulatorRegister);
+      } else {
+        DCHECK_EQ(index, new_target_index - 1);
+        __ masm()->Push(kInterpreterAccumulatorRegister,
+                        kJavaScriptCallNewTargetRegister);
+      }
+      // We pushed "index" registers, minus the one the prologue pushed, plus
+      // the two registers that included new_target.
+      register_count -= (index - 1 + 2);
+    }
+  }
+  if (register_count < 2 * kLoopUnrollSize) {
+    // If the frame is small enough, just unroll the frame fill completely.
+    for (int i = 0; i < register_count; i += 2) {
+      __ masm()->Push(kInterpreterAccumulatorRegister,
+                      kInterpreterAccumulatorRegister);
+    }
+  } else {
+    BaselineAssembler::ScratchRegisterScope temps(&basm_);
+    Register scratch = temps.AcquireScratch();
+
+    // Extract the first few registers to round to the unroll size.
+    int first_registers = register_count % kLoopUnrollSize;
+    for (int i = 0; i < first_registers; i += 2) {
+      __ masm()->Push(kInterpreterAccumulatorRegister,
+                      kInterpreterAccumulatorRegister);
+    }
+    __ Move(scratch, register_count / kLoopUnrollSize);
+    // We enter the loop unconditionally, so make sure we need to loop at least
+    // once.
+    DCHECK_GT(register_count / kLoopUnrollSize, 0);
+    Label loop;
+    __ Bind(&loop);
+    for (int i = 0; i < kLoopUnrollSize; i += 2) {
+      __ masm()->Push(kInterpreterAccumulatorRegister,
+                      kInterpreterAccumulatorRegister);
+    }
+    __ masm()->Sub64(scratch, scratch, 1);
+    __ JumpIf(Condition::kGreaterThan, &loop);
+  }
+  __ RecordComment("]");
+}
+
+void BaselineCompiler::VerifyFrameSize() {
+  __ masm()->Add64(kScratchReg, sp,
+                   RoundUp(InterpreterFrameConstants::kFixedFrameSizeFromFp +
+                               bytecode_->frame_size(),
+                           2 * kSystemPointerSize));
+  __ masm()->Assert(eq, AbortReason::kUnexpectedStackPointer, kScratchReg,
+                    Operand(fp));
+}
+
+#undef __
+
+}  // namespace baseline
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_BASELINE_RISCV64_BASELINE_COMPILER_RISCV64_INL_H_
diff --git a/chromium/v8/src/baseline/x64/baseline-assembler-x64-inl.h b/chromium/v8/src/baseline/x64/baseline-assembler-x64-inl.h
index 202f83c7615..98ed29a9cae 100644
--- a/chromium/v8/src/baseline/x64/baseline-assembler-x64-inl.h
+++ b/chromium/v8/src/baseline/x64/baseline-assembler-x64-inl.h
@@ -7,7 +7,6 @@
 
 #include "src/base/macros.h"
 #include "src/baseline/baseline-assembler.h"
-#include "src/codegen/interface-descriptors.h"
 #include "src/codegen/x64/register-x64.h"
 
 namespace v8 {
@@ -129,7 +128,7 @@ void BaselineAssembler::CallBuiltin(Builtins::Name builtin) {
   } else {
     __ RecordCommentForOffHeapTrampoline(builtin);
     __ Call(__ EntryFromBuiltinIndexAsOperand(builtin));
-    if (FLAG_code_comments) __ RecordComment("]");
+    __ RecordComment("]");
   }
 }
 
@@ -140,7 +139,7 @@ void BaselineAssembler::TailCallBuiltin(Builtins::Name builtin) {
   } else {
     __ RecordCommentForOffHeapTrampoline(builtin);
     __ Jump(__ EntryFromBuiltinIndexAsOperand(builtin));
-    if (FLAG_code_comments) __ RecordComment("]");
+    __ RecordComment("]");
   }
 }
 
@@ -160,7 +159,7 @@ void BaselineAssembler::CmpObjectType(Register object,
 }
 void BaselineAssembler::CmpInstanceType(Register map,
                                         InstanceType instance_type) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ AssertNotSmi(map);
     __ CmpObjectType(map, MAP_TYPE, kScratchRegister);
     __ Assert(equal, AbortReason::kUnexpectedValue);
@@ -201,7 +200,7 @@ void BaselineAssembler::Move(Register output, Handle<HeapObject> value) {
   __ Move(output, value);
 }
 void BaselineAssembler::Move(Register output, int32_t value) {
-  __ Move(output, Immediate(value));
+  __ Move(output, value);
 }
 void BaselineAssembler::MoveMaybeSmi(Register output, Register source) {
   __ mov_tagged(output, source);
@@ -326,7 +325,7 @@ void BaselineAssembler::StoreTaggedFieldWithWriteBarrier(Register target,
   DCHECK_NE(target, scratch);
   DCHECK_NE(value, scratch);
   __ StoreTaggedField(FieldOperand(target, offset), value);
-  __ RecordWriteField(target, offset, value, scratch, kDontSaveFPRegs);
+  __ RecordWriteField(target, offset, value, scratch, SaveFPRegsMode::kIgnore);
 }
 void BaselineAssembler::StoreTaggedFieldNoWriteBarrier(Register target,
                                                        int offset,
diff --git a/chromium/v8/src/baseline/x64/baseline-compiler-x64-inl.h b/chromium/v8/src/baseline/x64/baseline-compiler-x64-inl.h
index 73b43770e56..a4d547b0671 100644
--- a/chromium/v8/src/baseline/x64/baseline-compiler-x64-inl.h
+++ b/chromium/v8/src/baseline/x64/baseline-compiler-x64-inl.h
@@ -18,9 +18,9 @@ namespace baseline {
 void BaselineCompiler::Prologue() {
   DCHECK_EQ(kJSFunctionRegister, kJavaScriptCallTargetRegister);
   int max_frame_size = bytecode_->frame_size() + max_call_args_;
-  CallBuiltin(Builtins::kBaselineOutOfLinePrologue, kContextRegister,
-              kJSFunctionRegister, kJavaScriptCallArgCountRegister,
-              max_frame_size, kJavaScriptCallNewTargetRegister, bytecode_);
+  CallBuiltin<Builtins::kBaselineOutOfLinePrologue>(
+      kContextRegister, kJSFunctionRegister, kJavaScriptCallArgCountRegister,
+      max_frame_size, kJavaScriptCallNewTargetRegister, bytecode_);
 
   PrologueFillFrame();
 }
diff --git a/chromium/v8/src/bigint/bigint-internal.cc b/chromium/v8/src/bigint/bigint-internal.cc
new file mode 100644
index 00000000000..6630c6c4c9d
--- /dev/null
+++ b/chromium/v8/src/bigint/bigint-internal.cc
@@ -0,0 +1,43 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/bigint/bigint-internal.h"
+
+namespace v8 {
+namespace bigint {
+
+ProcessorImpl::ProcessorImpl(Platform* platform) : platform_(platform) {}
+
+ProcessorImpl::~ProcessorImpl() { delete platform_; }
+
+Status ProcessorImpl::get_and_clear_status() {
+  Status result = status_;
+  status_ = Status::kOk;
+  return result;
+}
+
+Processor* Processor::New(Platform* platform) {
+  ProcessorImpl* impl = new ProcessorImpl(platform);
+  return static_cast<Processor*>(impl);
+}
+
+void Processor::Destroy() { delete static_cast<ProcessorImpl*>(this); }
+
+void ProcessorImpl::Multiply(RWDigits Z, Digits X, Digits Y) {
+  X.Normalize();
+  Y.Normalize();
+  if (X.len() == 0 || Y.len() == 0) return Z.Clear();
+  if (X.len() < Y.len()) std::swap(X, Y);
+  if (Y.len() == 1) return MultiplySingle(Z, X, Y[0]);
+  return MultiplySchoolbook(Z, X, Y);
+}
+
+Status Processor::Multiply(RWDigits Z, Digits X, Digits Y) {
+  ProcessorImpl* impl = static_cast<ProcessorImpl*>(this);
+  impl->Multiply(Z, X, Y);
+  return impl->get_and_clear_status();
+}
+
+}  // namespace bigint
+}  // namespace v8
diff --git a/chromium/v8/src/bigint/bigint-internal.h b/chromium/v8/src/bigint/bigint-internal.h
new file mode 100644
index 00000000000..efe63a06a51
--- /dev/null
+++ b/chromium/v8/src/bigint/bigint-internal.h
@@ -0,0 +1,65 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_BIGINT_BIGINT_INTERNAL_H_
+#define V8_BIGINT_BIGINT_INTERNAL_H_
+
+#include "src/bigint/bigint.h"
+
+namespace v8 {
+namespace bigint {
+
+class ProcessorImpl : public Processor {
+ public:
+  explicit ProcessorImpl(Platform* platform);
+  ~ProcessorImpl();
+
+  Status get_and_clear_status();
+
+  void Multiply(RWDigits Z, Digits X, Digits Y);
+  void MultiplySingle(RWDigits Z, Digits X, digit_t y);
+  void MultiplySchoolbook(RWDigits Z, Digits X, Digits Y);
+
+ private:
+  // Each unit is supposed to represent approximately one CPU {mul} instruction.
+  // Doesn't need to be accurate; we just want to make sure to check for
+  // interrupt requests every now and then (roughly every 10-100 ms; often
+  // enough not to appear stuck, rarely enough not to cause noticeable
+  // overhead).
+  static const uintptr_t kWorkEstimateThreshold = 5000000;
+
+  void AddWorkEstimate(uintptr_t estimate) {
+    work_estimate_ += estimate;
+    if (work_estimate_ >= kWorkEstimateThreshold) {
+      work_estimate_ = 0;
+      if (platform_->InterruptRequested()) {
+        status_ = Status::kInterrupted;
+      }
+    }
+  }
+
+  bool should_terminate() { return status_ == Status::kInterrupted; }
+
+  uintptr_t work_estimate_{0};
+  Status status_{Status::kOk};
+  Platform* platform_;
+};
+
+#define CHECK(cond)                                   \
+  if (!(cond)) {                                      \
+    std::cerr << __FILE__ << ":" << __LINE__ << ": "; \
+    std::cerr << "Assertion failed: " #cond "\n";     \
+    abort();                                          \
+  }
+
+#ifdef DEBUG
+#define DCHECK(cond) CHECK(cond)
+#else
+#define DCHECK(cond) (void(0))
+#endif
+
+}  // namespace bigint
+}  // namespace v8
+
+#endif  // V8_BIGINT_BIGINT_INTERNAL_H_
diff --git a/chromium/v8/src/bigint/bigint.h b/chromium/v8/src/bigint/bigint.h
index a87622b167a..a365359c530 100644
--- a/chromium/v8/src/bigint/bigint.h
+++ b/chromium/v8/src/bigint/bigint.h
@@ -120,9 +120,117 @@ class Digits {
   }
 };
 
+// Writable version of a Digits array.
+// Does not own the memory it points at.
+class RWDigits : public Digits {
+ public:
+  RWDigits(digit_t* mem, int len) : Digits(mem, len) {}
+  RWDigits(RWDigits src, int offset, int len) : Digits(src, offset, len) {}
+  RWDigits operator+(int i) {
+    BIGINT_H_DCHECK(i >= 0 && i <= len_);
+    return RWDigits(digits_ + i, len_ - i);
+  }
+
+#if UINTPTR_MAX == 0xFFFFFFFF
+  digit_t& operator[](int i) {
+    BIGINT_H_DCHECK(i >= 0 && i < len_);
+    return digits_[i];
+  }
+#else
+  // 64-bit platform. We only require digits arrays to be 4-byte aligned,
+  // so we use a wrapper class to allow regular array syntax while
+  // performing unaligned memory accesses under the hood.
+  class WritableDigitReference {
+   public:
+    // Support "X[i] = x" notation.
+    void operator=(digit_t digit) { memcpy(ptr_, &digit, sizeof(digit)); }
+    // Support "X[i] = Y[j]" notation.
+    WritableDigitReference& operator=(const WritableDigitReference& src) {
+      memcpy(ptr_, src.ptr_, sizeof(digit_t));
+      return *this;
+    }
+    // Support "x = X[i]" notation.
+    operator digit_t() {
+      digit_t result;
+      memcpy(&result, ptr_, sizeof(result));
+      return result;
+    }
+
+   private:
+    // This class is not for public consumption.
+    friend class RWDigits;
+    // Primary constructor.
+    explicit WritableDigitReference(digit_t* ptr)
+        : ptr_(reinterpret_cast<uint32_t*>(ptr)) {}
+    // Required for returning WDR instances from "operator[]" below.
+    WritableDigitReference(const WritableDigitReference& src) = default;
+
+    uint32_t* ptr_;
+  };
+
+  WritableDigitReference operator[](int i) {
+    BIGINT_H_DCHECK(i >= 0 && i < len_);
+    return WritableDigitReference(digits_ + i);
+  }
+#endif
+
+  digit_t* digits() { return digits_; }
+  void set_len(int len) { len_ = len; }
+
+  void Clear() { memset(digits_, 0, len_ * sizeof(digit_t)); }
+};
+
+class Platform {
+ public:
+  virtual ~Platform() = default;
+
+  // If you want the ability to interrupt long-running operations, implement
+  // a Platform subclass that overrides this method. It will be queried
+  // every now and then by long-running operations.
+  virtual bool InterruptRequested() { return false; }
+};
+
+// These are the operations that this library supports.
+// The signatures follow the convention:
+//
+//   void Operation(RWDigits results, Digits inputs);
+//
+// You must preallocate the result; use the respective {OperationResultLength}
+// function to determine its minimum required length. The actual result may
+// be smaller, so you should call result.Normalize() on the result.
+//
+// The operations are divided into two groups: "fast" (O(n) with small
+// coefficient) operations are exposed directly as free functions, "slow"
+// operations are methods on a {BigIntProcessor} object, which provides
+// support for interrupting execution via the {Platform}'s {InterruptRequested}
+// mechanism when it takes too long. These functions return a {Status} value.
+
 // Returns r such that r < 0 if A < B; r > 0 if A > B; r == 0 if A == B.
 int Compare(Digits A, Digits B);
 
+enum class Status { kOk, kInterrupted };
+
+class Processor {
+ public:
+  // Takes ownership of {platform}.
+  static Processor* New(Platform* platform);
+
+  // Use this for any std::unique_ptr holding an instance of BigIntProcessor.
+  class Destroyer {
+   public:
+    void operator()(Processor* proc) { proc->Destroy(); }
+  };
+  // When not using std::unique_ptr, call this to delete the instance.
+  void Destroy();
+
+  // Z := X * Y
+  Status Multiply(RWDigits Z, Digits X, Digits Y);
+};
+
+inline int MultiplyResultLength(Digits X, Digits Y) {
+  return X.len() + Y.len();
+}
+
 }  // namespace bigint
 }  // namespace v8
 
diff --git a/chromium/v8/src/bigint/digit-arithmetic.h b/chromium/v8/src/bigint/digit-arithmetic.h
new file mode 100644
index 00000000000..1c5c93c0353
--- /dev/null
+++ b/chromium/v8/src/bigint/digit-arithmetic.h
@@ -0,0 +1,87 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Helper functions that operate on individual digits.
+
+#ifndef V8_BIGINT_DIGIT_ARITHMETIC_H_
+#define V8_BIGINT_DIGIT_ARITHMETIC_H_
+
+#include "src/bigint/bigint.h"
+
+namespace v8 {
+namespace bigint {
+
+static constexpr int kHalfDigitBits = kDigitBits / 2;
+static constexpr digit_t kHalfDigitBase = digit_t{1} << kHalfDigitBits;
+static constexpr digit_t kHalfDigitMask = kHalfDigitBase - 1;
+
+// {carry} will be set to 0 or 1.
+inline digit_t digit_add2(digit_t a, digit_t b, digit_t* carry) {
+#if HAVE_TWODIGIT_T
+  twodigit_t result = twodigit_t{a} + b;
+  *carry = result >> kDigitBits;
+  return static_cast<digit_t>(result);
+#else
+  digit_t result = a + b;
+  *carry = (result < a) ? 1 : 0;
+  return result;
+#endif
+}
+
+// This compiles to slightly better machine code than repeated invocations
+// of {digit_add2}.
+inline digit_t digit_add3(digit_t a, digit_t b, digit_t c, digit_t* carry) {
+#if HAVE_TWODIGIT_T
+  twodigit_t result = twodigit_t{a} + b + c;
+  *carry = result >> kDigitBits;
+  return static_cast<digit_t>(result);
+#else
+  digit_t result = a + b;
+  *carry = (result < a) ? 1 : 0;
+  result += c;
+  if (result < c) *carry += 1;
+  return result;
+#endif
+}
+
+// Returns the low half of the result. High half is in {high}.
+inline digit_t digit_mul(digit_t a, digit_t b, digit_t* high) {
+#if HAVE_TWODIGIT_T
+  twodigit_t result = twodigit_t{a} * b;
+  *high = result >> kDigitBits;
+  return static_cast<digit_t>(result);
+#else
+  // Multiply in half-pointer-sized chunks.
+  // For inputs [AH AL]*[BH BL], the result is:
+  //
+  //            [AL*BL]  // r_low
+  //    +    [AL*BH]     // r_mid1
+  //    +    [AH*BL]     // r_mid2
+  //    + [AH*BH]        // r_high
+  //    = [R4 R3 R2 R1]  // high = [R4 R3], low = [R2 R1]
+  //
+  // Where of course we must be careful with carries between the columns.
+  digit_t a_low = a & kHalfDigitMask;
+  digit_t a_high = a >> kHalfDigitBits;
+  digit_t b_low = b & kHalfDigitMask;
+  digit_t b_high = b >> kHalfDigitBits;
+
+  digit_t r_low = a_low * b_low;
+  digit_t r_mid1 = a_low * b_high;
+  digit_t r_mid2 = a_high * b_low;
+  digit_t r_high = a_high * b_high;
+
+  digit_t carry = 0;
+  digit_t low = digit_add3(r_low, r_mid1 << kHalfDigitBits,
+                           r_mid2 << kHalfDigitBits, &carry);
+  *high =
+      (r_mid1 >> kHalfDigitBits) + (r_mid2 >> kHalfDigitBits) + r_high + carry;
+  return low;
+#endif
+}
+
+}  // namespace bigint
+}  // namespace v8
+
+#endif  // V8_BIGINT_DIGIT_ARITHMETIC_H_
diff --git a/chromium/v8/src/bigint/mul-schoolbook.cc b/chromium/v8/src/bigint/mul-schoolbook.cc
new file mode 100644
index 00000000000..8e10685018c
--- /dev/null
+++ b/chromium/v8/src/bigint/mul-schoolbook.cc
@@ -0,0 +1,99 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/bigint/bigint-internal.h"
+#include "src/bigint/digit-arithmetic.h"
+#include "src/bigint/vector-arithmetic.h"
+
+namespace v8 {
+namespace bigint {
+
+// Z := X * y, where y is a single digit.
+void ProcessorImpl::MultiplySingle(RWDigits Z, Digits X, digit_t y) {
+  DCHECK(y != 0);  // NOLINT(readability/check)
+  digit_t carry = 0;
+  digit_t high = 0;
+  for (int i = 0; i < X.len(); i++) {
+    digit_t new_high;
+    digit_t low = digit_mul(X[i], y, &new_high);
+    Z[i] = digit_add3(low, high, carry, &carry);
+    high = new_high;
+  }
+  AddWorkEstimate(X.len());
+  Z[X.len()] = carry + high;
+  for (int i = X.len() + 1; i < Z.len(); i++) Z[i] = 0;
+}
+
+#define BODY(min, max)                              \
+  for (int j = min; j <= max; j++) {                \
+    digit_t high;                                   \
+    digit_t low = digit_mul(X[j], Y[i - j], &high); \
+    digit_t carrybit;                               \
+    zi = digit_add2(zi, low, &carrybit);            \
+    carry += carrybit;                              \
+    next = digit_add2(next, high, &carrybit);       \
+    next_carry += carrybit;                         \
+  }                                                 \
+  Z[i] = zi
+
+// Z := X * Y.
+// O(n²) "schoolbook" multiplication algorithm. Optimized to minimize
+// bounds and overflow checks: rather than looping over X for every digit
+// of Y (or vice versa), we loop over Z. The {BODY} macro above is what
+// computes one of Z's digits as a sum of the products of relevant digits
+// of X and Y. This yields a nearly 2x improvement compared to more obvious
+// implementations.
+// This method is *highly* performance sensitive even for the advanced
+// algorithms, which use this as the base case of their recursive calls.
+void ProcessorImpl::MultiplySchoolbook(RWDigits Z, Digits X, Digits Y) {
+  DCHECK(IsDigitNormalized(X));
+  DCHECK(IsDigitNormalized(Y));
+  DCHECK(X.len() >= Y.len());
+  DCHECK(Z.len() >= X.len() + Y.len());
+  if (X.len() == 0 || Y.len() == 0) return Z.Clear();
+  digit_t next, next_carry = 0, carry = 0;
+  // Unrolled first iteration: it's trivial.
+  Z[0] = digit_mul(X[0], Y[0], &next);
+  int i = 1;
+  // Unrolled second iteration: a little less setup.
+  if (i < Y.len()) {
+    digit_t zi = next;
+    next = 0;
+    BODY(0, 1);
+    i++;
+  }
+  // Main part: since X.len() >= Y.len() > i, no bounds checks are needed.
+  for (; i < Y.len(); i++) {
+    digit_t zi = digit_add2(next, carry, &carry);
+    next = next_carry + carry;
+    carry = 0;
+    next_carry = 0;
+    BODY(0, i);
+    AddWorkEstimate(i);
+    if (should_terminate()) return;
+  }
+  // Last part: i exceeds Y now, we have to be careful about bounds.
+  int loop_end = X.len() + Y.len() - 2;
+  for (; i <= loop_end; i++) {
+    int max_x_index = std::min(i, X.len() - 1);
+    int max_y_index = Y.len() - 1;
+    int min_x_index = i - max_y_index;
+    digit_t zi = digit_add2(next, carry, &carry);
+    next = next_carry + carry;
+    carry = 0;
+    next_carry = 0;
+    BODY(min_x_index, max_x_index);
+    AddWorkEstimate(max_x_index - min_x_index);
+    if (should_terminate()) return;
+  }
+  // Write the last digit, and zero out any extra space in Z.
+  Z[i++] = digit_add2(next, carry, &carry);
+  DCHECK(carry == 0);  // NOLINT(readability/check)
+  for (; i < Z.len(); i++) Z[i] = 0;
+}
+
+#undef BODY
+
+}  // namespace bigint
+}  // namespace v8
diff --git a/chromium/v8/src/bigint/vector-arithmetic.cc b/chromium/v8/src/bigint/vector-arithmetic.cc
index 9a28b168ba5..734b4439110 100644
--- a/chromium/v8/src/bigint/vector-arithmetic.cc
+++ b/chromium/v8/src/bigint/vector-arithmetic.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "src/bigint/bigint.h"
+#include "src/bigint/vector-arithmetic.h"
 
 namespace v8 {
 namespace bigint {
diff --git a/chromium/v8/src/bigint/vector-arithmetic.h b/chromium/v8/src/bigint/vector-arithmetic.h
new file mode 100644
index 00000000000..617cb20b552
--- /dev/null
+++ b/chromium/v8/src/bigint/vector-arithmetic.h
@@ -0,0 +1,20 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Helper functions that operate on {Digits} vectors of digits.
+
+#ifndef V8_BIGINT_VECTOR_ARITHMETIC_H_
+#define V8_BIGINT_VECTOR_ARITHMETIC_H_
+
+#include "src/bigint/bigint.h"
+
+namespace v8 {
+namespace bigint {
+
+inline bool IsDigitNormalized(Digits X) { return X.len() == 0 || X.msd() != 0; }
+
+}  // namespace bigint
+}  // namespace v8
+
+#endif  // V8_BIGINT_VECTOR_ARITHMETIC_H_
diff --git a/chromium/v8/src/builtins/accessors.cc b/chromium/v8/src/builtins/accessors.cc
index c255184caeb..0285b33e1f6 100644
--- a/chromium/v8/src/builtins/accessors.cc
+++ b/chromium/v8/src/builtins/accessors.cc
@@ -113,8 +113,7 @@ void Accessors::ReconfigureToDataProperty(
     v8::Local<v8::Name> key, v8::Local<v8::Value> val,
     const v8::PropertyCallbackInfo<v8::Boolean>& info) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(info.GetIsolate());
-  RuntimeCallTimerScope stats_scope(
-      isolate, RuntimeCallCounterId::kReconfigureToDataProperty);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kReconfigureToDataProperty);
   HandleScope scope(isolate);
   Handle<Object> receiver = Utils::OpenHandle(*info.This());
   Handle<JSObject> holder =
@@ -155,8 +154,7 @@ Handle<AccessorInfo> Accessors::MakeArgumentsIteratorInfo(Isolate* isolate) {
 void Accessors::ArrayLengthGetter(
     v8::Local<v8::Name> name, const v8::PropertyCallbackInfo<v8::Value>& info) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(info.GetIsolate());
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kArrayLengthGetter);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kArrayLengthGetter);
   DisallowGarbageCollection no_gc;
   HandleScope scope(isolate);
   JSArray holder = JSArray::cast(*Utils::OpenHandle(*info.Holder()));
@@ -168,8 +166,7 @@ void Accessors::ArrayLengthSetter(
     v8::Local<v8::Name> name, v8::Local<v8::Value> val,
     const v8::PropertyCallbackInfo<v8::Boolean>& info) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(info.GetIsolate());
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kArrayLengthSetter);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kArrayLengthSetter);
   HandleScope scope(isolate);
 
   DCHECK(Utils::OpenHandle(*name)->SameValue(
@@ -206,7 +203,12 @@ void Accessors::ArrayLengthSetter(
     return;
   }
 
-  JSArray::SetLength(array, length);
+  if (JSArray::SetLength(array, length).IsNothing()) {
+    // TODO(victorgomes): AccessorNameBooleanSetterCallback does not handle
+    // exceptions.
+    FATAL("Fatal JavaScript invalid array length %u", length);
+    UNREACHABLE();
+  }
 
   uint32_t actual_new_len = 0;
   CHECK(array->length().ToArrayLength(&actual_new_len));
@@ -282,8 +284,7 @@ Handle<AccessorInfo> Accessors::MakeModuleNamespaceEntryInfo(
 void Accessors::StringLengthGetter(
     v8::Local<v8::Name> name, const v8::PropertyCallbackInfo<v8::Value>& info) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(info.GetIsolate());
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kStringLengthGetter);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kStringLengthGetter);
   DisallowGarbageCollection no_gc;
   HandleScope scope(isolate);
 
@@ -330,8 +331,7 @@ static Handle<Object> GetFunctionPrototype(Isolate* isolate,
 void Accessors::FunctionPrototypeGetter(
     v8::Local<v8::Name> name, const v8::PropertyCallbackInfo<v8::Value>& info) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(info.GetIsolate());
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kFunctionPrototypeGetter);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kFunctionPrototypeGetter);
   HandleScope scope(isolate);
   Handle<JSFunction> function =
       Handle<JSFunction>::cast(Utils::OpenHandle(*info.Holder()));
@@ -344,8 +344,7 @@ void Accessors::FunctionPrototypeSetter(
     v8::Local<v8::Name> name, v8::Local<v8::Value> val,
     const v8::PropertyCallbackInfo<v8::Boolean>& info) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(info.GetIsolate());
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kFunctionPrototypeSetter);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kFunctionPrototypeSetter);
   HandleScope scope(isolate);
   Handle<Object> value = Utils::OpenHandle(*val);
   Handle<JSFunction> object =
@@ -367,8 +366,7 @@ Handle<AccessorInfo> Accessors::MakeFunctionPrototypeInfo(Isolate* isolate) {
 void Accessors::FunctionLengthGetter(
     v8::Local<v8::Name> name, const v8::PropertyCallbackInfo<v8::Value>& info) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(info.GetIsolate());
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kFunctionLengthGetter);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kFunctionLengthGetter);
   HandleScope scope(isolate);
   Handle<JSFunction> function =
       Handle<JSFunction>::cast(Utils::OpenHandle(*info.Holder()));
@@ -722,8 +720,7 @@ Handle<AccessorInfo> Accessors::MakeFunctionCallerInfo(Isolate* isolate) {
 void Accessors::BoundFunctionLengthGetter(
     v8::Local<v8::Name> name, const v8::PropertyCallbackInfo<v8::Value>& info) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(info.GetIsolate());
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kBoundFunctionLengthGetter);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kBoundFunctionLengthGetter);
   HandleScope scope(isolate);
   Handle<JSBoundFunction> function =
       Handle<JSBoundFunction>::cast(Utils::OpenHandle(*info.Holder()));
@@ -749,8 +746,7 @@ Handle<AccessorInfo> Accessors::MakeBoundFunctionLengthInfo(Isolate* isolate) {
 void Accessors::BoundFunctionNameGetter(
     v8::Local<v8::Name> name, const v8::PropertyCallbackInfo<v8::Value>& info) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(info.GetIsolate());
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kBoundFunctionNameGetter);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kBoundFunctionNameGetter);
   HandleScope scope(isolate);
   Handle<JSBoundFunction> function =
       Handle<JSBoundFunction>::cast(Utils::OpenHandle(*info.Holder()));
diff --git a/chromium/v8/src/builtins/aggregate-error.tq b/chromium/v8/src/builtins/aggregate-error.tq
index 9c70ffcb006..c811403274d 100644
--- a/chromium/v8/src/builtins/aggregate-error.tq
+++ b/chromium/v8/src/builtins/aggregate-error.tq
@@ -19,8 +19,9 @@ transitioning javascript builtin AggregateErrorConstructor(
   //   [[Writable]]: *true*, [[Enumerable]]: *false*, [[Configurable]]: *true*
   //   c. Perform ! DefinePropertyOrThrow(_O_, *"message"*, _msgDesc_).
   const message: JSAny = arguments[1];
-  const obj: JSObject =
-      ConstructAggregateErrorHelper(context, target, newTarget, message);
+  const options: JSAny = arguments[2];
+  const obj: JSObject = ConstructAggregateErrorHelper(
+      context, target, newTarget, message, options);
 
   // 4. Let errorsList be ? IterableToList(errors).
   const errors: JSAny = arguments[0];
@@ -38,7 +39,7 @@ transitioning javascript builtin AggregateErrorConstructor(
 }
 
 extern transitioning runtime ConstructAggregateErrorHelper(
-    Context, JSFunction, JSAny, Object): JSObject;
+    Context, JSFunction, JSAny, Object, Object): JSObject;
 
 extern transitioning runtime ConstructInternalAggregateErrorHelper(
     Context, Object): JSObject;
diff --git a/chromium/v8/src/builtins/arm/builtins-arm.cc b/chromium/v8/src/builtins/arm/builtins-arm.cc
index 817d30fe26a..83252446af8 100644
--- a/chromium/v8/src/builtins/arm/builtins-arm.cc
+++ b/chromium/v8/src/builtins/arm/builtins-arm.cc
@@ -6,6 +6,7 @@
 
 #include "src/api/api-arguments.h"
 #include "src/codegen/code-factory.h"
+#include "src/codegen/interface-descriptors-inl.h"
 // For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
 #include "src/codegen/macro-assembler-inl.h"
 #include "src/codegen/register-configuration.h"
@@ -118,7 +119,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     // r0: number of arguments (untagged)
     // r1: constructor function
     // r3: new target
-    __ InvokeFunctionWithNewTarget(r1, r3, r0, CALL_FUNCTION);
+    __ InvokeFunctionWithNewTarget(r1, r3, r0, InvokeType::kCall);
 
     // Restore context from the frame.
     __ ldr(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
@@ -236,7 +237,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
   __ Push(r6);
 
   // Call the function.
-  __ InvokeFunctionWithNewTarget(r1, r3, r0, CALL_FUNCTION);
+  __ InvokeFunctionWithNewTarget(r1, r3, r0, InvokeType::kCall);
 
   // ----------- S t a t e -------------
   //  --                 r0: constructor result
@@ -337,7 +338,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Store input value into generator object.
   __ str(r0, FieldMemOperand(r1, JSGeneratorObject::kInputOrDebugPosOffset));
   __ RecordWriteField(r1, JSGeneratorObject::kInputOrDebugPosOffset, r0,
-                      kLRHasNotBeenSaved, kDontSaveFPRegs);
+                      kLRHasNotBeenSaved, SaveFPRegsMode::kIgnore);
 
   // Load suspended function and context.
   __ ldr(r4, FieldMemOperand(r1, JSGeneratorObject::kFunctionOffset));
@@ -388,16 +389,13 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
          FieldMemOperand(r1, JSGeneratorObject::kParametersAndRegistersOffset));
   {
     Label done_loop, loop;
-    __ mov(r6, r3);
-
     __ bind(&loop);
-    __ sub(r6, r6, Operand(1), SetCC);
+    __ sub(r3, r3, Operand(1), SetCC);
     __ b(lt, &done_loop);
-    __ add(scratch, r2, Operand(r6, LSL, kTaggedSizeLog2));
+    __ add(scratch, r2, Operand(r3, LSL, kTaggedSizeLog2));
     __ ldr(scratch, FieldMemOperand(scratch, FixedArray::kHeaderSize));
     __ Push(scratch);
     __ b(&loop);
-
     __ bind(&done_loop);
 
     // Push receiver.
@@ -799,8 +797,8 @@ static void ReplaceClosureCodeWithOptimizedCode(MacroAssembler* masm,
   // Store code entry in the closure.
   __ str(optimized_code, FieldMemOperand(closure, JSFunction::kCodeOffset));
   __ RecordWriteField(closure, JSFunction::kCodeOffset, optimized_code,
-                      kLRHasNotBeenSaved, kDontSaveFPRegs, OMIT_REMEMBERED_SET,
-                      OMIT_SMI_CHECK);
+                      kLRHasNotBeenSaved, SaveFPRegsMode::kIgnore,
+                      RememberedSetAction::kOmit, SmiCheck::kOmit);
 }
 
 static void LeaveInterpreterFrame(MacroAssembler* masm, Register scratch1,
@@ -1051,7 +1049,7 @@ void Builtins::Generate_BaselineOutOfLinePrologue(MacroAssembler* masm) {
   __ ldr(feedback_vector,
          FieldMemOperand(closure, JSFunction::kFeedbackCellOffset));
   __ ldr(feedback_vector, FieldMemOperand(feedback_vector, Cell::kValueOffset));
-  if (__ emit_debug_code()) {
+  if (FLAG_debug_code) {
     UseScratchRegisterScope temps(masm);
     Register scratch = temps.Acquire();
     __ CompareObjectType(feedback_vector, scratch, scratch,
@@ -1124,7 +1122,7 @@ void Builtins::Generate_BaselineOutOfLinePrologue(MacroAssembler* masm) {
 
   // Baseline code frames store the feedback vector where interpreter would
   // store the bytecode offset.
-  if (__ emit_debug_code()) {
+  if (FLAG_debug_code) {
     UseScratchRegisterScope temps(masm);
     Register scratch = temps.Acquire();
     __ CompareObjectType(feedback_vector, scratch, scratch,
@@ -1646,7 +1644,7 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   __ Jump(kJavaScriptCallCodeStartRegister);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtNextBytecode(MacroAssembler* masm) {
   // Get bytecode array and bytecode offset from the stack frame.
   __ ldr(kInterpreterBytecodeArrayRegister,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
@@ -1691,7 +1689,7 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
   __ Abort(AbortReason::kInvalidBytecodeAdvance);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeDispatch(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtBytecode(MacroAssembler* masm) {
   Generate_InterpreterEnterBytecode(masm);
 }
 
@@ -1841,6 +1839,8 @@ void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_BaselineOnStackReplacement(MacroAssembler* masm) {
+  __ ldr(kContextRegister,
+         MemOperand(fp, BaselineFrameConstants::kContextOffset));
   return OnStackReplacement(masm, false);
 }
 
@@ -2009,6 +2009,7 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
 }
 
 // static
+// TODO(v8:11615): Observe Code::kMaxArguments in CallOrConstructVarargs
 void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
                                                Handle<Code> code) {
   // ----------- S t a t e -------------
@@ -2020,7 +2021,7 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
   // -----------------------------------
   Register scratch = r8;
 
-  if (masm->emit_debug_code()) {
+  if (FLAG_debug_code) {
     // Allow r2 to be a FixedArray, or a FixedDoubleArray if r4 == 0.
     Label ok, fail;
     __ AssertNotSmi(r2);
@@ -2278,7 +2279,7 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
 
   __ ldrh(r2,
           FieldMemOperand(r2, SharedFunctionInfo::kFormalParameterCountOffset));
-  __ InvokeFunctionCode(r1, no_reg, r2, r0, JUMP_FUNCTION);
+  __ InvokeFunctionCode(r1, no_reg, r2, r0, InvokeType::kJump);
 
   // The function is a "classConstructor", need to raise an exception.
   __ bind(&class_constructor);
@@ -2640,6 +2641,11 @@ void Builtins::Generate_GenericJSToWasmWrapper(MacroAssembler* masm) {
   // TODO(v8:10701): Implement for this platform.
   __ Trap();
 }
+
+void Builtins::Generate_WasmOnStackReplace(MacroAssembler* masm) {
+  // Only needed on x64.
+  __ Trap();
+}
 #endif  // V8_ENABLE_WEBASSEMBLY
 
 void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
@@ -2652,12 +2658,12 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // sp: stack pointer  (restored as callee's sp after C call)
   // cp: current context  (C callee-saved)
   //
-  // If argv_mode == kArgvInRegister:
+  // If argv_mode == ArgvMode::kRegister:
   // r2: pointer to the first argument
 
   __ mov(r5, Operand(r1));
 
-  if (argv_mode == kArgvInRegister) {
+  if (argv_mode == ArgvMode::kRegister) {
     // Move argv into the correct register.
     __ mov(r1, Operand(r2));
   } else {
@@ -2669,7 +2675,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // Enter the exit frame that transitions from JavaScript to C++.
   FrameScope scope(masm, StackFrame::MANUAL);
   __ EnterExitFrame(
-      save_doubles == kSaveFPRegs, 0,
+      save_doubles == SaveFPRegsMode::kSave, 0,
       builtin_exit_frame ? StackFrame::BUILTIN_EXIT : StackFrame::EXIT);
 
   // Store a copy of argc in callee-saved registers for later.
@@ -2726,12 +2732,12 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // r0:r1: result
   // sp: stack pointer
   // fp: frame pointer
-  Register argc = argv_mode == kArgvInRegister
+  Register argc = argv_mode == ArgvMode::kRegister
                       // We don't want to pop arguments so set argc to no_reg.
                       ? no_reg
                       // Callee-saved register r4 still holds argc.
                       : r4;
-  __ LeaveExitFrame(save_doubles == kSaveFPRegs, argc);
+  __ LeaveExitFrame(save_doubles == SaveFPRegsMode::kSave, argc);
   __ mov(pc, lr);
 
   // Handling of exception.
@@ -2841,7 +2847,7 @@ void Builtins::Generate_DoubleToI(MacroAssembler* masm) {
   // If we reach this code, 30 <= exponent <= 83.
   // `TryInlineTruncateDoubleToI` above will have truncated any double with an
   // exponent lower than 30.
-  if (masm->emit_debug_code()) {
+  if (FLAG_debug_code) {
     // Scratch is exponent - 1.
     __ cmp(scratch, Operand(30 - 1));
     __ Check(ge, AbortReason::kUnexpectedValue);
@@ -2957,7 +2963,7 @@ void CallApiFunctionAndReturn(MacroAssembler* masm, Register function_address,
   // No more valid handles (the result handle was the last one). Restore
   // previous handle scope.
   __ str(r4, MemOperand(r9, kNextOffset));
-  if (__ emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ ldr(r1, MemOperand(r9, kLevelOffset));
     __ cmp(r1, r6);
     __ Check(eq, AbortReason::kUnexpectedLevelAfterReturnFromApiCall);
diff --git a/chromium/v8/src/builtins/arm64/builtins-arm64.cc b/chromium/v8/src/builtins/arm64/builtins-arm64.cc
index d095d60b302..3cf3f0153fc 100644
--- a/chromium/v8/src/builtins/arm64/builtins-arm64.cc
+++ b/chromium/v8/src/builtins/arm64/builtins-arm64.cc
@@ -6,6 +6,7 @@
 
 #include "src/api/api-arguments.h"
 #include "src/codegen/code-factory.h"
+#include "src/codegen/interface-descriptors-inl.h"
 // For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
 #include "src/codegen/macro-assembler-inl.h"
 #include "src/codegen/register-configuration.h"
@@ -99,7 +100,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     Label already_aligned;
     Register argc = x0;
 
-    if (__ emit_debug_code()) {
+    if (FLAG_debug_code) {
       // Check that FrameScope pushed the context on to the stack already.
       __ Peek(x2, 0);
       __ Cmp(x2, cp);
@@ -176,7 +177,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     // -----------------------------------
 
     // Call the function.
-    __ InvokeFunctionWithNewTarget(x1, x3, argc, CALL_FUNCTION);
+    __ InvokeFunctionWithNewTarget(x1, x3, argc, InvokeType::kCall);
 
     // Restore the context from the frame.
     __ Ldr(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
@@ -219,7 +220,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
   __ EnterFrame(StackFrame::CONSTRUCT);
   Label post_instantiation_deopt_entry, not_create_implicit_receiver;
 
-  if (__ emit_debug_code()) {
+  if (FLAG_debug_code) {
     // Check that FrameScope pushed the context on to the stack already.
     __ Peek(x2, 0);
     __ Cmp(x2, cp);
@@ -336,7 +337,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
 
   // Call the function.
   __ Mov(x0, x12);
-  __ InvokeFunctionWithNewTarget(x1, x3, x0, CALL_FUNCTION);
+  __ InvokeFunctionWithNewTarget(x1, x3, x0, InvokeType::kCall);
 
   // ----------- S t a t e -------------
   //  -- sp[0*kSystemPointerSize]: implicit receiver
@@ -442,7 +443,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   __ StoreTaggedField(
       x0, FieldMemOperand(x1, JSGeneratorObject::kInputOrDebugPosOffset));
   __ RecordWriteField(x1, JSGeneratorObject::kInputOrDebugPosOffset, x0,
-                      kLRHasNotBeenSaved, kDontSaveFPRegs);
+                      kLRHasNotBeenSaved, SaveFPRegsMode::kIgnore);
 
   // Load suspended function and context.
   __ LoadTaggedPointerField(
@@ -639,7 +640,8 @@ void Generate_JSEntryVariant(MacroAssembler* masm, StackFrame::Type type,
 
 #ifdef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
     // Initialize the pointer cage base register.
-    __ Mov(kPointerCageBaseRegister, x0);
+    __ LoadRootRelative(kPtrComprCageBaseRegister,
+                        IsolateData::cage_base_offset());
 #endif
   }
 
@@ -925,7 +927,7 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
     // Don't initialize the reserved registers.
     // x26 : root register (kRootRegister).
     // x27 : context pointer (cp).
-    // x28 : pointer cage base register (kPointerCageBaseRegister).
+    // x28 : pointer cage base register (kPtrComprCageBaseRegister).
     // x29 : frame pointer (fp).
 
     Handle<Code> builtin = is_construct
@@ -966,8 +968,8 @@ static void ReplaceClosureCodeWithOptimizedCode(MacroAssembler* masm,
   __ StoreTaggedField(optimized_code,
                       FieldMemOperand(closure, JSFunction::kCodeOffset));
   __ RecordWriteField(closure, JSFunction::kCodeOffset, optimized_code,
-                      kLRHasNotBeenSaved, kDontSaveFPRegs, OMIT_REMEMBERED_SET,
-                      OMIT_SMI_CHECK);
+                      kLRHasNotBeenSaved, SaveFPRegsMode::kIgnore,
+                      RememberedSetAction::kOmit, SmiCheck::kOmit);
 }
 
 static void LeaveInterpreterFrame(MacroAssembler* masm, Register scratch1,
@@ -998,7 +1000,7 @@ static void LeaveInterpreterFrame(MacroAssembler* masm, Register scratch1,
   __ LeaveFrame(StackFrame::INTERPRETED);
 
   // Drop receiver + arguments.
-  if (__ emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ Tst(params_size, kSystemPointerSize - 1);
     __ Check(eq, AbortReason::kUnexpectedValue);
   }
@@ -1230,7 +1232,7 @@ void Builtins::Generate_BaselineOutOfLinePrologue(MacroAssembler* masm) {
       FieldMemOperand(closure, JSFunction::kFeedbackCellOffset));
   __ LoadTaggedPointerField(
       feedback_vector, FieldMemOperand(feedback_vector, Cell::kValueOffset));
-  if (__ emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ CompareObjectType(feedback_vector, x4, x4, FEEDBACK_VECTOR_TYPE);
     __ Assert(eq, AbortReason::kExpectedFeedbackVector);
   }
@@ -1288,7 +1290,7 @@ void Builtins::Generate_BaselineOutOfLinePrologue(MacroAssembler* masm) {
 
   // Baseline code frames store the feedback vector where interpreter would
   // store the bytecode offset.
-  if (__ emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ CompareObjectType(feedback_vector, x4, x4, FEEDBACK_VECTOR_TYPE);
     __ Assert(eq, AbortReason::kExpectedFeedbackVector);
   }
@@ -1859,7 +1861,7 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   __ Br(x17);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtNextBytecode(MacroAssembler* masm) {
   // Get bytecode array and bytecode offset from the stack frame.
   __ ldr(kInterpreterBytecodeArrayRegister,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
@@ -1903,7 +1905,7 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
   __ Abort(AbortReason::kInvalidBytecodeAdvance);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeDispatch(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtBytecode(MacroAssembler* masm) {
   Generate_InterpreterEnterBytecode(masm);
 }
 
@@ -2087,6 +2089,8 @@ void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_BaselineOnStackReplacement(MacroAssembler* masm) {
+  __ ldr(kContextRegister,
+         MemOperand(fp, BaselineFrameConstants::kContextOffset));
   return OnStackReplacement(masm, false);
 }
 
@@ -2385,6 +2389,7 @@ void Generate_PrepareForCopyingVarargs(MacroAssembler* masm, Register argc,
 }  // namespace
 
 // static
+// TODO(v8:11615): Observe Code::kMaxArguments in CallOrConstructVarargs
 void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
                                                Handle<Code> code) {
   // ----------- S t a t e -------------
@@ -2394,7 +2399,7 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
   //  -- x4 : len (number of elements to push from args)
   //  -- x3 : new.target (for [[Construct]])
   // -----------------------------------
-  if (masm->emit_debug_code()) {
+  if (FLAG_debug_code) {
     // Allow x2 to be a FixedArray, or a FixedDoubleArray if x4 == 0.
     Label ok, fail;
     __ AssertNotSmi(x2, AbortReason::kOperandIsNotAFixedArray);
@@ -2618,7 +2623,7 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
 
   __ Ldrh(x2,
           FieldMemOperand(x2, SharedFunctionInfo::kFormalParameterCountOffset));
-  __ InvokeFunctionCode(x1, no_reg, x2, x0, JUMP_FUNCTION);
+  __ InvokeFunctionCode(x1, no_reg, x2, x0, InvokeType::kJump);
 
   // The function is a "classConstructor", need to raise an exception.
   __ Bind(&class_constructor);
@@ -3036,6 +3041,11 @@ void Builtins::Generate_GenericJSToWasmWrapper(MacroAssembler* masm) {
   // TODO(v8:10701): Implement for this platform.
   __ Trap();
 }
+
+void Builtins::Generate_WasmOnStackReplace(MacroAssembler* masm) {
+  // Only needed on x64.
+  __ Trap();
+}
 #endif  // V8_ENABLE_WEBASSEMBLY
 
 void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
@@ -3053,7 +3063,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // Register parameters:
   //    x0: argc (including receiver, untagged)
   //    x1: target
-  // If argv_mode == kArgvInRegister:
+  // If argv_mode == ArgvMode::kRegister:
   //    x11: argv (pointer to first argument)
   //
   // The stack on entry holds the arguments and the receiver, with the receiver
@@ -3085,7 +3095,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // (arg[argc-2]), or just below the receiver in case there are no arguments.
   //  - Adjust for the arg[] array.
   Register temp_argv = x11;
-  if (argv_mode == kArgvOnStack) {
+  if (argv_mode == ArgvMode::kStack) {
     __ SlotAddress(temp_argv, x0);
     //  - Adjust for the receiver.
     __ Sub(temp_argv, temp_argv, 1 * kSystemPointerSize);
@@ -3096,7 +3106,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // Enter the exit frame.
   FrameScope scope(masm, StackFrame::MANUAL);
   __ EnterExitFrame(
-      save_doubles == kSaveFPRegs, x10, extra_stack_space,
+      save_doubles == SaveFPRegsMode::kSave, x10, extra_stack_space,
       builtin_exit_frame ? StackFrame::BUILTIN_EXIT : StackFrame::EXIT);
 
   // Poke callee-saved registers into reserved space.
@@ -3177,8 +3187,8 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   __ Peek(argc, 2 * kSystemPointerSize);
   __ Peek(target, 3 * kSystemPointerSize);
 
-  __ LeaveExitFrame(save_doubles == kSaveFPRegs, x10, x9);
-  if (argv_mode == kArgvOnStack) {
+  __ LeaveExitFrame(save_doubles == SaveFPRegsMode::kSave, x10, x9);
+  if (argv_mode == ArgvMode::kStack) {
     // Drop the remaining stack slots and return from the stub.
     __ DropArguments(x11);
   }
@@ -3247,7 +3257,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
 
   // Compute the handler entry address and jump to it. We use x17 here for the
   // jump target, as this jump can occasionally end up at the start of
-  // InterpreterEnterBytecodeDispatch, which when CFI is enabled starts with
+  // InterpreterEnterAtBytecode, which when CFI is enabled starts with
   // a "BTI c".
   UseScratchRegisterScope temps(masm);
   temps.Exclude(x17);
@@ -3296,7 +3306,7 @@ void Builtins::Generate_DoubleToI(MacroAssembler* masm) {
   // signed overflow in the int64_t target. Since we've already handled
   // exponents >= 84, we can guarantee that 63 <= exponent < 84.
 
-  if (masm->emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ Cmp(exponent, HeapNumber::kExponentBias + 63);
     // Exponents less than this should have been handled by the Fcvt case.
     __ Check(ge, AbortReason::kUnexpectedValue);
@@ -3412,7 +3422,7 @@ void CallApiFunctionAndReturn(MacroAssembler* masm, Register function_address,
   // No more valid handles (the result handle was the last one). Restore
   // previous handle scope.
   __ Str(next_address_reg, MemOperand(handle_scope_base, kNextOffset));
-  if (__ emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ Ldr(w1, MemOperand(handle_scope_base, kLevelOffset));
     __ Cmp(w1, level_reg);
     __ Check(eq, AbortReason::kUnexpectedLevelAfterReturnFromApiCall);
diff --git a/chromium/v8/src/builtins/arraybuffer.tq b/chromium/v8/src/builtins/arraybuffer.tq
index 179c4b38fd2..5794414443b 100644
--- a/chromium/v8/src/builtins/arraybuffer.tq
+++ b/chromium/v8/src/builtins/arraybuffer.tq
@@ -9,21 +9,25 @@ transitioning javascript builtin ArrayBufferPrototypeGetByteLength(
     js-implicit context: NativeContext, receiver: JSAny)(): Number {
   // 1. Let O be the this value.
   // 2. Perform ? RequireInternalSlot(O, [[ArrayBufferData]]).
+  const functionName = 'get ArrayBuffer.prototype.byteLength';
   const o = Cast<JSArrayBuffer>(receiver) otherwise
   ThrowTypeError(
-      MessageTemplate::kIncompatibleMethodReceiver,
-      'get ArrayBuffer.prototype.byteLength', receiver);
+      MessageTemplate::kIncompatibleMethodReceiver, functionName, receiver);
   // 3. If IsSharedArrayBuffer(O) is true, throw a TypeError exception.
   if (IsSharedArrayBuffer(o)) {
     ThrowTypeError(
-        MessageTemplate::kIncompatibleMethodReceiver,
-        'get ArrayBuffer.prototype.byteLength', receiver);
+        MessageTemplate::kIncompatibleMethodReceiver, functionName, receiver);
   }
-  // 4. If IsDetachedBuffer(O) is true, throw a TypeError exception.
+  // 4. If IsResizableArrayBuffer(O) is true, throw a TypeError exception.
+  if (IsResizableArrayBuffer(o)) {
+    ThrowTypeError(
+        MessageTemplate::kIncompatibleMethodReceiver, functionName, receiver);
+  }
+  // 5. If IsDetachedBuffer(O) is true, throw a TypeError exception.
   // TODO(v8:4895): We don't actually throw here.
-  // 5. Let length be O.[[ArrayBufferByteLength]].
+  // 6. Let length be O.[[ArrayBufferByteLength]].
   const length = o.byte_length;
-  // 6. Return length.
+  // 7. Return length.
   return Convert<Number>(length);
 }
 
@@ -32,15 +36,43 @@ transitioning javascript builtin SharedArrayBufferPrototypeGetByteLength(
     js-implicit context: NativeContext, receiver: JSAny)(): Number {
   // 1. Let O be the this value.
   // 2. Perform ? RequireInternalSlot(O, [[ArrayBufferData]]).
+  const functionName = 'get SharedArrayBuffer.prototype.byteLength';
   const o = Cast<JSArrayBuffer>(receiver) otherwise
   ThrowTypeError(
-      MessageTemplate::kIncompatibleMethodReceiver,
-      'get SharedArrayBuffer.prototype.byteLength', receiver);
-  // 3. If IsSharedArrayBuffer(O) is false, throw a TypeError exception.
+      MessageTemplate::kIncompatibleMethodReceiver, functionName, receiver);
+  // 3. Perform ? RequireInternalSlot(O, [[ArrayBufferData]]).
   if (!IsSharedArrayBuffer(o)) {
     ThrowTypeError(
-        MessageTemplate::kIncompatibleMethodReceiver,
-        'get SharedArrayBuffer.prototype.byteLength', receiver);
+        MessageTemplate::kIncompatibleMethodReceiver, functionName, receiver);
+  }
+  // 4. If IsResizableArrayBuffer(O) is true, throw a TypeError exception.
+  if (IsResizableArrayBuffer(o)) {
+    ThrowTypeError(
+        MessageTemplate::kIncompatibleMethodReceiver, functionName, receiver);
+  }
+  // 5. Let length be O.[[ArrayBufferByteLength]].
+  const length = o.byte_length;
+  // 6. Return length.
+  return Convert<Number>(length);
+}
+
+// #sec-get-resizablearraybuffer.prototype.bytelength
+transitioning javascript builtin ResizableArrayBufferPrototypeGetByteLength(
+    js-implicit context: NativeContext, receiver: JSAny)(): Number {
+  // 1. Let O be the this value.
+  // 2. Perform ? RequireInternalSlot(O, [[ArrayBufferMaxByteLength]]).
+  const functionName = 'get ResizableArrayBuffer.prototype.byteLength';
+  const o = Cast<JSArrayBuffer>(receiver) otherwise
+  ThrowTypeError(
+      MessageTemplate::kIncompatibleMethodReceiver, functionName, receiver);
+  if (!IsResizableArrayBuffer(o)) {
+    ThrowTypeError(
+        MessageTemplate::kIncompatibleMethodReceiver, functionName, receiver);
+  }
+  // 3. If IsSharedArrayBuffer(O) is true, throw a TypeError exception.
+  if (IsSharedArrayBuffer(o)) {
+    ThrowTypeError(
+        MessageTemplate::kIncompatibleMethodReceiver, functionName, receiver);
   }
   // 4. Let length be O.[[ArrayBufferByteLength]].
   const length = o.byte_length;
@@ -48,6 +80,55 @@ transitioning javascript builtin SharedArrayBufferPrototypeGetByteLength(
   return Convert<Number>(length);
 }
 
+// #sec-get-resizablearraybuffer.prototype.maxbytelength
+transitioning javascript builtin ResizableArrayBufferPrototypeGetMaxByteLength(
+    js-implicit context: NativeContext, receiver: JSAny)(): Number {
+  // 1. Let O be the this value.
+  // 2. Perform ? RequireInternalSlot(O, [[ArrayBufferMaxByteLength]]).
+  const functionName = 'get ResizableArrayBuffer.prototype.maxByteLength';
+  const o = Cast<JSArrayBuffer>(receiver) otherwise
+  ThrowTypeError(
+      MessageTemplate::kIncompatibleMethodReceiver, functionName, receiver);
+  if (!IsResizableArrayBuffer(o)) {
+    ThrowTypeError(
+        MessageTemplate::kIncompatibleMethodReceiver, functionName, receiver);
+  }
+  // 3. If IsSharedArrayBuffer(O) is true, throw a TypeError exception.
+  if (IsSharedArrayBuffer(o)) {
+    ThrowTypeError(
+        MessageTemplate::kIncompatibleMethodReceiver, functionName, receiver);
+  }
+  // 4. Let length be O.[[ArrayBufferMaxByteLength]].
+  const length = o.max_byte_length;
+  // 5. Return length.
+  return Convert<Number>(length);
+}
+
+// #sec-get-growablesharedarraybuffer.prototype.maxbytelength
+transitioning javascript builtin
+GrowableSharedArrayBufferPrototypeGetMaxByteLength(
+    js-implicit context: NativeContext, receiver: JSAny)(): Number {
+  // 1. Let O be the this value.
+  // 2. Perform ? RequireInternalSlot(O, [[ArrayBufferMaxByteLength]]).
+  const functionName = 'get GrowableSharedArrayBuffer.prototype.maxByteLength';
+  const o = Cast<JSArrayBuffer>(receiver) otherwise
+  ThrowTypeError(
+      MessageTemplate::kIncompatibleMethodReceiver, functionName, receiver);
+  if (!IsResizableArrayBuffer(o)) {
+    ThrowTypeError(
+        MessageTemplate::kIncompatibleMethodReceiver, functionName, receiver);
+  }
+  // 3. If IsSharedArrayBuffer(O) is false, throw a TypeError exception.
+  if (!IsSharedArrayBuffer(o)) {
+    ThrowTypeError(
+        MessageTemplate::kIncompatibleMethodReceiver, functionName, receiver);
+  }
+  // 4. Let length be O.[[ArrayBufferMaxByteLength]].
+  const length = o.max_byte_length;
+  // 5. Return length.
+  return Convert<Number>(length);
+}
+
 // #sec-arraybuffer.isview
 transitioning javascript builtin ArrayBufferIsView(arg: JSAny): Boolean {
   // 1. If Type(arg) is not Object, return false.
diff --git a/chromium/v8/src/builtins/base.tq b/chromium/v8/src/builtins/base.tq
index 08639c04daf..fc84e1a2ce4 100644
--- a/chromium/v8/src/builtins/base.tq
+++ b/chromium/v8/src/builtins/base.tq
@@ -141,6 +141,7 @@ intrinsic %MakeLazy<T: type, A1: type, A2: type, A3: type>(
 // template, but Torque doesn't understand how to use templates for extern
 // macros, so just add whatever overload definitions you need here.
 extern macro RunLazy(Lazy<Smi>): Smi;
+extern macro RunLazy(Lazy<JSAny>): JSAny;
 
 // A Smi value containing a bitfield struct as its integer data.
 @useParentTypeChecker type SmiTagged<T : type extends uint31> extends Smi;
@@ -262,6 +263,8 @@ extern enum UpdateFeedbackMode { kOptionalFeedback, kGuaranteedFeedback }
 extern operator '==' macro UpdateFeedbackModeEqual(
     constexpr UpdateFeedbackMode, constexpr UpdateFeedbackMode): constexpr bool;
 
+extern enum CallFeedbackContent extends int32 { kTarget, kReceiver }
+
 extern enum UnicodeEncoding { UTF16, UTF32 }
 
 // Promise constants
@@ -961,6 +964,8 @@ extern operator '|' macro ConstexprWord32Or(
     constexpr int32, constexpr int32): constexpr int32;
 extern operator '^' macro Word32Xor(int32, int32): int32;
 extern operator '^' macro Word32Xor(uint32, uint32): uint32;
+extern operator '<<' macro ConstexprWord32Shl(
+    constexpr uint32, constexpr int32): uint32;
 
 extern operator '==' macro Word64Equal(int64, int64): bool;
 extern operator '==' macro Word64Equal(uint64, uint64): bool;
@@ -1296,6 +1301,9 @@ macro GetFastAliasedArgumentsMap(implicit context: Context)(): Map {
 macro GetWeakCellMap(implicit context: Context)(): Map {
   return %GetClassMapConstant<WeakCell>();
 }
+macro GetPrototypeApplyFunction(implicit context: Context)(): JSFunction {
+  return *NativeContextSlot(ContextSlot::FUNCTION_PROTOTYPE_APPLY_INDEX);
+}
 
 // Call(Context, Target, Receiver, ...Args)
 // TODO(joshualitt): Assuming the context parameter is for throwing when Target
@@ -1689,7 +1697,7 @@ extern transitioning runtime SetOwnPropertyIgnoreAttributes(
 
 namespace runtime {
 extern runtime
-GetDerivedMap(Context, JSFunction, JSReceiver): Map;
+GetDerivedMap(Context, JSFunction, JSReceiver, JSAny): Map;
 }
 extern macro IsDeprecatedMap(Map): bool;
 
diff --git a/chromium/v8/src/builtins/builtins-api.cc b/chromium/v8/src/builtins/builtins-api.cc
index 35e6cc393cb..b39bfc84a55 100644
--- a/chromium/v8/src/builtins/builtins-api.cc
+++ b/chromium/v8/src/builtins/builtins-api.cc
@@ -23,8 +23,7 @@ namespace {
 // TODO(dcarney): CallOptimization duplicates this logic, merge.
 JSReceiver GetCompatibleReceiver(Isolate* isolate, FunctionTemplateInfo info,
                                  JSReceiver receiver) {
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kGetCompatibleReceiver);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kGetCompatibleReceiver);
   Object recv_type = info.signature();
   // No signature, return holder.
   if (!recv_type.IsFunctionTemplateInfo()) return receiver;
@@ -171,8 +170,7 @@ MaybeHandle<Object> Builtins::InvokeApiFunction(Isolate* isolate,
                                                 Handle<Object> receiver,
                                                 int argc, Handle<Object> args[],
                                                 Handle<HeapObject> new_target) {
-  RuntimeCallTimerScope timer(isolate,
-                              RuntimeCallCounterId::kInvokeApiFunction);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kInvokeApiFunction);
   DCHECK(function->IsFunctionTemplateInfo() ||
          (function->IsJSFunction() &&
           JSFunction::cast(*function).shared().IsApiFunction()));
diff --git a/chromium/v8/src/builtins/builtins-array-gen.cc b/chromium/v8/src/builtins/builtins-array-gen.cc
index 6b522fda6c0..833627c7b41 100644
--- a/chromium/v8/src/builtins/builtins-array-gen.cc
+++ b/chromium/v8/src/builtins/builtins-array-gen.cc
@@ -10,6 +10,7 @@
 #include "src/builtins/builtins-utils-gen.h"
 #include "src/builtins/builtins.h"
 #include "src/codegen/code-stub-assembler.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/execution/frame-constants.h"
 #include "src/heap/factory-inl.h"
 #include "src/objects/allocation-site-inl.h"
diff --git a/chromium/v8/src/builtins/builtins-array.cc b/chromium/v8/src/builtins/builtins-array.cc
index d3bbd980a55..6fe1bfc712f 100644
--- a/chromium/v8/src/builtins/builtins-array.cc
+++ b/chromium/v8/src/builtins/builtins-array.cc
@@ -173,7 +173,8 @@ V8_WARN_UNUSED_RESULT MaybeHandle<Object> SetLengthProperty(
     Handle<JSArray> array = Handle<JSArray>::cast(receiver);
     if (!JSArray::HasReadOnlyLength(array)) {
       DCHECK_LE(length, kMaxUInt32);
-      JSArray::SetLength(array, static_cast<uint32_t>(length));
+      MAYBE_RETURN_NULL(
+          JSArray::SetLength(array, static_cast<uint32_t>(length)));
       return receiver;
     }
   }
@@ -207,16 +208,16 @@ V8_WARN_UNUSED_RESULT Object GenericArrayFill(Isolate* isolate,
   return *receiver;
 }
 
-V8_WARN_UNUSED_RESULT bool TryFastArrayFill(
+V8_WARN_UNUSED_RESULT Maybe<bool> TryFastArrayFill(
     Isolate* isolate, BuiltinArguments* args, Handle<JSReceiver> receiver,
     Handle<Object> value, double start_index, double end_index) {
   // If indices are too large, use generic path since they are stored as
   // properties, not in the element backing store.
-  if (end_index > kMaxUInt32) return false;
-  if (!receiver->IsJSObject()) return false;
+  if (end_index > kMaxUInt32) return Just(false);
+  if (!receiver->IsJSObject()) return Just(false);
 
   if (!EnsureJSArrayWithWritableFastElements(isolate, receiver, args, 1, 1)) {
-    return false;
+    return Just(false);
   }
 
   Handle<JSArray> array = Handle<JSArray>::cast(receiver);
@@ -240,14 +241,14 @@ V8_WARN_UNUSED_RESULT bool TryFastArrayFill(
   CHECK(DoubleToUint32IfEqualToSelf(end_index, &end));
 
   ElementsAccessor* accessor = array->GetElementsAccessor();
-  accessor->Fill(array, value, start, end);
-  return true;
+  RETURN_ON_EXCEPTION_VALUE(isolate, accessor->Fill(array, value, start, end),
+                            Nothing<bool>());
+  return Just(true);
 }
 }  // namespace
 
 BUILTIN(ArrayPrototypeFill) {
   HandleScope scope(isolate);
-
   if (isolate->debug_execution_mode() == DebugInfo::kSideEffects) {
     if (!isolate->debug()->PerformSideEffectCheckForObject(args.receiver())) {
       return ReadOnlyRoots(isolate).exception();
@@ -292,10 +293,12 @@ BUILTIN(ArrayPrototypeFill) {
 
   Handle<Object> value = args.atOrUndefined(isolate, 1);
 
-  if (TryFastArrayFill(isolate, &args, receiver, value, start_index,
-                       end_index)) {
-    return *receiver;
-  }
+  bool success;
+  MAYBE_ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, success,
+      TryFastArrayFill(isolate, &args, receiver, value, start_index,
+                       end_index));
+  if (success) return *receiver;
   return GenericArrayFill(isolate, receiver, value, start_index, end_index);
 }
 
@@ -385,7 +388,9 @@ BUILTIN(ArrayPush) {
   }
 
   ElementsAccessor* accessor = array->GetElementsAccessor();
-  uint32_t new_length = accessor->Push(array, &args, to_add);
+  uint32_t new_length;
+  MAYBE_ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, new_length, accessor->Push(array, &args, to_add));
   return *isolate->factory()->NewNumberFromUint((new_length));
 }
 
@@ -468,7 +473,8 @@ BUILTIN(ArrayPop) {
   Handle<Object> result;
   if (IsJSArrayFastElementMovingAllowed(isolate, JSArray::cast(*receiver))) {
     // Fast Elements Path
-    result = array->GetElementsAccessor()->Pop(array);
+    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+        isolate, result, array->GetElementsAccessor()->Pop(array));
   } else {
     // Use Slow Lookup otherwise
     uint32_t new_length = len - 1;
@@ -483,7 +489,9 @@ BUILTIN(ArrayPop) {
                                 isolate->factory()->length_string(),
                                 Object::TypeOf(isolate, array), array));
     }
-    JSArray::SetLength(array, new_length);
+    bool set_len_ok;
+    MAYBE_ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+        isolate, set_len_ok, JSArray::SetLength(array, new_length));
   }
 
   return *result;
@@ -595,7 +603,8 @@ BUILTIN(ArrayShift) {
 
   if (CanUseFastArrayShift(isolate, receiver)) {
     Handle<JSArray> array = Handle<JSArray>::cast(receiver);
-    return *array->GetElementsAccessor()->Shift(array);
+    RETURN_RESULT_OR_FAILURE(isolate,
+                             array->GetElementsAccessor()->Shift(array));
   }
 
   return GenericArrayShift(isolate, receiver, length);
@@ -623,7 +632,9 @@ BUILTIN(ArrayUnshift) {
   DCHECK(!JSArray::HasReadOnlyLength(array));
 
   ElementsAccessor* accessor = array->GetElementsAccessor();
-  int new_length = accessor->Unshift(array, &args, to_add);
+  uint32_t new_length;
+  MAYBE_ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, new_length, accessor->Unshift(array, &args, to_add));
   return Smi::FromInt(new_length);
 }
 
@@ -742,7 +753,7 @@ class ArrayConcatVisitor {
         array, fast_elements() ? HOLEY_ELEMENTS : DICTIONARY_ELEMENTS);
     array->set_length(*length);
     array->set_elements(*storage_fixed_array());
-    array->synchronized_set_map(*map);
+    array->set_map(*map, kReleaseStore);
     return array;
   }
 
@@ -880,9 +891,11 @@ uint32_t EstimateElementCount(Isolate* isolate, Handle<JSArray> array) {
 #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) case TYPE##_ELEMENTS:
 
       TYPED_ARRAYS(TYPED_ARRAY_CASE)
-#undef TYPED_ARRAY_CASE
+      RAB_GSAB_TYPED_ARRAYS(TYPED_ARRAY_CASE)
       // External arrays are always dense.
       return length;
+
+#undef TYPED_ARRAY_CASE
     case NO_ELEMENTS:
       return 0;
     case FAST_SLOPPY_ARGUMENTS_ELEMENTS:
@@ -956,9 +969,7 @@ void CollectElementIndices(Isolate* isolate, Handle<JSObject> object,
     }
 #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) case TYPE##_ELEMENTS:
 
-      TYPED_ARRAYS(TYPED_ARRAY_CASE)
-#undef TYPED_ARRAY_CASE
-      {
+      TYPED_ARRAYS(TYPED_ARRAY_CASE) {
         size_t length = Handle<JSTypedArray>::cast(object)->length();
         if (range <= length) {
           length = range;
@@ -974,6 +985,11 @@ void CollectElementIndices(Isolate* isolate, Handle<JSObject> object,
         if (length == range) return;  // All indices accounted for already.
         break;
       }
+      RAB_GSAB_TYPED_ARRAYS(TYPED_ARRAY_CASE)
+      // TODO(v8:11111): Support RAB / GSAB.
+      UNREACHABLE();
+
+#undef TYPED_ARRAY_CASE
     case FAST_SLOPPY_ARGUMENTS_ELEMENTS:
     case SLOW_SLOPPY_ARGUMENTS_ELEMENTS: {
       DisallowGarbageCollection no_gc;
@@ -1199,8 +1215,11 @@ bool IterateElements(Isolate* isolate, Handle<JSReceiver> receiver,
       break;
 #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) case TYPE##_ELEMENTS:
       TYPED_ARRAYS(TYPED_ARRAY_CASE)
-#undef TYPED_ARRAY_CASE
       return IterateElementsSlow(isolate, receiver, length, visitor);
+      RAB_GSAB_TYPED_ARRAYS(TYPED_ARRAY_CASE)
+      // TODO(v8:11111): Support RAB / GSAB.
+      UNREACHABLE();
+#undef TYPED_ARRAY_CASE
     case FAST_STRING_WRAPPER_ELEMENTS:
     case SLOW_STRING_WRAPPER_ELEMENTS:
       // |array| is guaranteed to be an array or typed array.
diff --git a/chromium/v8/src/builtins/builtins-arraybuffer.cc b/chromium/v8/src/builtins/builtins-arraybuffer.cc
index 0f5f9051861..2d07847d570 100644
--- a/chromium/v8/src/builtins/builtins-arraybuffer.cc
+++ b/chromium/v8/src/builtins/builtins-arraybuffer.cc
@@ -23,17 +23,43 @@ namespace internal {
                      name));                                                \
   }
 
+#define CHECK_RESIZABLE(expected, name, method)                             \
+  if (name->is_resizable() != expected) {                                   \
+    THROW_NEW_ERROR_RETURN_FAILURE(                                         \
+        isolate,                                                            \
+        NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,          \
+                     isolate->factory()->NewStringFromAsciiChecked(method), \
+                     name));                                                \
+  }
+
 // -----------------------------------------------------------------------------
 // ES#sec-arraybuffer-objects
 
 namespace {
 
+bool RoundUpToPageSize(size_t byte_length, size_t page_size,
+                       size_t max_allowed_byte_length, size_t* pages) {
+  size_t bytes_wanted = RoundUp(byte_length, page_size);
+  if (bytes_wanted > max_allowed_byte_length) {
+    return false;
+  }
+  *pages = bytes_wanted / page_size;
+  return true;
+}
+
 Object ConstructBuffer(Isolate* isolate, Handle<JSFunction> target,
                        Handle<JSReceiver> new_target, Handle<Object> length,
-                       InitializedFlag initialized) {
-  SharedFlag shared = (*target != target->native_context().array_buffer_fun())
-                          ? SharedFlag::kShared
-                          : SharedFlag::kNotShared;
+                       Handle<Object> max_length, InitializedFlag initialized) {
+  SharedFlag shared =
+      (*target != target->native_context().array_buffer_fun() &&
+       *target != target->native_context().resizable_array_buffer_fun())
+          ? SharedFlag::kShared
+          : SharedFlag::kNotShared;
+  ResizableFlag resizable =
+      (*target == target->native_context().resizable_array_buffer_fun() ||
+       *target == target->native_context().growable_shared_array_buffer_fun())
+          ? ResizableFlag::kResizable
+          : ResizableFlag::kNotResizable;
   Handle<JSObject> result;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
       isolate, result,
@@ -42,9 +68,10 @@ Object ConstructBuffer(Isolate* isolate, Handle<JSFunction> target,
   // Ensure that all fields are initialized because BackingStore::Allocate is
   // allowed to GC. Note that we cannot move the allocation of the ArrayBuffer
   // after BackingStore::Allocate because of the spec.
-  array_buffer->Setup(shared, nullptr);
+  array_buffer->Setup(shared, resizable, nullptr);
 
   size_t byte_length;
+  size_t max_byte_length = 0;
   if (!TryNumberToSize(*length, &byte_length) ||
       byte_length > JSArrayBuffer::kMaxByteLength) {
     // ToNumber failed.
@@ -52,8 +79,46 @@ Object ConstructBuffer(Isolate* isolate, Handle<JSFunction> target,
         isolate, NewRangeError(MessageTemplate::kInvalidArrayBufferLength));
   }
 
-  auto backing_store =
-      BackingStore::Allocate(isolate, byte_length, shared, initialized);
+  std::unique_ptr<BackingStore> backing_store;
+  if (resizable == ResizableFlag::kNotResizable) {
+    backing_store =
+        BackingStore::Allocate(isolate, byte_length, shared, initialized);
+  } else {
+    Handle<Object> number_max_length;
+    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, number_max_length,
+                                       Object::ToInteger(isolate, max_length));
+
+    if (!TryNumberToSize(*number_max_length, &max_byte_length)) {
+      THROW_NEW_ERROR_RETURN_FAILURE(
+          isolate,
+          NewRangeError(MessageTemplate::kInvalidArrayBufferMaxLength));
+    }
+    if (byte_length > max_byte_length) {
+      THROW_NEW_ERROR_RETURN_FAILURE(
+          isolate,
+          NewRangeError(MessageTemplate::kInvalidArrayBufferMaxLength));
+    }
+
+    size_t page_size = AllocatePageSize();
+    size_t initial_pages;
+    if (!RoundUpToPageSize(byte_length, page_size,
+                           JSArrayBuffer::kMaxByteLength, &initial_pages)) {
+      THROW_NEW_ERROR_RETURN_FAILURE(
+          isolate, NewRangeError(MessageTemplate::kInvalidArrayBufferLength));
+    }
+
+    size_t max_pages;
+    if (!RoundUpToPageSize(max_byte_length, page_size,
+                           JSArrayBuffer::kMaxByteLength, &max_pages)) {
+      THROW_NEW_ERROR_RETURN_FAILURE(
+          isolate,
+          NewRangeError(MessageTemplate::kInvalidArrayBufferMaxLength));
+    }
+    constexpr bool kIsWasmMemory = false;
+    backing_store = BackingStore::TryAllocateAndPartiallyCommitMemory(
+        isolate, byte_length, page_size, initial_pages, max_pages,
+        kIsWasmMemory, shared);
+  }
   if (!backing_store) {
     // Allocation of backing store failed.
     THROW_NEW_ERROR_RETURN_FAILURE(
@@ -61,6 +126,7 @@ Object ConstructBuffer(Isolate* isolate, Handle<JSFunction> target,
   }
 
   array_buffer->Attach(std::move(backing_store));
+  array_buffer->set_max_byte_length(max_byte_length);
   return *array_buffer;
 }
 
@@ -71,7 +137,10 @@ BUILTIN(ArrayBufferConstructor) {
   HandleScope scope(isolate);
   Handle<JSFunction> target = args.target();
   DCHECK(*target == target->native_context().array_buffer_fun() ||
-         *target == target->native_context().shared_array_buffer_fun());
+         *target == target->native_context().shared_array_buffer_fun() ||
+         *target == target->native_context().resizable_array_buffer_fun() ||
+         *target ==
+             target->native_context().growable_shared_array_buffer_fun());
   if (args.new_target()->IsUndefined(isolate)) {  // [[Call]]
     THROW_NEW_ERROR_RETURN_FAILURE(
         isolate, NewTypeError(MessageTemplate::kConstructorNotFunction,
@@ -87,10 +156,11 @@ BUILTIN(ArrayBufferConstructor) {
   if (number_length->Number() < 0.0) {
     THROW_NEW_ERROR_RETURN_FAILURE(
         isolate, NewRangeError(MessageTemplate::kInvalidArrayBufferLength));
-    }
+  }
 
-    return ConstructBuffer(isolate, target, new_target, number_length,
-                           InitializedFlag::kZeroInitialized);
+  Handle<Object> max_length = args.atOrUndefined(isolate, 2);
+  return ConstructBuffer(isolate, target, new_target, number_length, max_length,
+                         InitializedFlag::kZeroInitialized);
 }
 
 // This is a helper to construct an ArrayBuffer with uinitialized memory.
@@ -101,7 +171,7 @@ BUILTIN(ArrayBufferConstructor_DoNotInitialize) {
   Handle<JSFunction> target(isolate->native_context()->array_buffer_fun(),
                             isolate);
   Handle<Object> length = args.atOrUndefined(isolate, 1);
-  return ConstructBuffer(isolate, target, target, length,
+  return ConstructBuffer(isolate, target, target, length, Handle<Object>(),
                          InitializedFlag::kUninitialized);
 }
 
@@ -119,6 +189,8 @@ static Object SliceHelper(BuiltinArguments args, Isolate* isolate,
   // * [SAB] If IsSharedArrayBuffer(O) is false, throw a TypeError exception.
   CHECK_SHARED(is_shared, array_buffer, kMethodName);
 
+  CHECK_RESIZABLE(false, array_buffer, kMethodName);
+
   // * [AB] If IsDetachedBuffer(buffer) is true, throw a TypeError exception.
   if (!is_shared && array_buffer->was_detached()) {
     THROW_NEW_ERROR_RETURN_FAILURE(
@@ -280,5 +352,158 @@ BUILTIN(ArrayBufferPrototypeSlice) {
   return SliceHelper(args, isolate, kMethodName, false);
 }
 
+static Object ResizeHelper(BuiltinArguments args, Isolate* isolate,
+                           const char* kMethodName, bool is_shared) {
+  HandleScope scope(isolate);
+
+  // 1 Let O be the this value.
+  // 2. Perform ? RequireInternalSlot(O, [[ArrayBufferMaxByteLength]]).
+  CHECK_RECEIVER(JSArrayBuffer, array_buffer, kMethodName);
+  CHECK_RESIZABLE(true, array_buffer, kMethodName);
+
+  // [RAB] 3. If IsSharedArrayBuffer(O) is true, throw a *TypeError* exception
+  // [GSAB] 3. If IsSharedArrayBuffer(O) is false, throw a *TypeError* exception
+  CHECK_SHARED(is_shared, array_buffer, kMethodName);
+
+  // Let newByteLength to ? ToIntegerOrInfinity(newLength).
+  Handle<Object> new_length = args.at(1);
+  Handle<Object> number_new_byte_length;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, number_new_byte_length,
+                                     Object::ToInteger(isolate, new_length));
+
+  // [RAB] If IsDetachedBuffer(O) is true, throw a TypeError exception.
+  if (!is_shared && array_buffer->was_detached()) {
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate, NewTypeError(MessageTemplate::kDetachedOperation,
+                              isolate->factory()->NewStringFromAsciiChecked(
+                                  kMethodName)));
+  }
+
+  // [RAB] If newByteLength < 0 or newByteLength >
+  // O.[[ArrayBufferMaxByteLength]], throw a RangeError exception.
+
+  // [GSAB] If newByteLength < currentByteLength or newByteLength >
+  // O.[[ArrayBufferMaxByteLength]], throw a RangeError exception.
+  size_t new_byte_length;
+  if (!TryNumberToSize(*number_new_byte_length, &new_byte_length)) {
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate, NewRangeError(MessageTemplate::kInvalidArrayBufferResizeLength,
+                               isolate->factory()->NewStringFromAsciiChecked(
+                                   kMethodName)));
+  }
+
+  if (is_shared && new_byte_length < array_buffer->byte_length()) {
+    // GrowableSharedArrayBuffer is only allowed to grow.
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate, NewRangeError(MessageTemplate::kInvalidArrayBufferResizeLength,
+                               isolate->factory()->NewStringFromAsciiChecked(
+                                   kMethodName)));
+  }
+
+  if (new_byte_length > array_buffer->max_byte_length()) {
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate, NewRangeError(MessageTemplate::kInvalidArrayBufferResizeLength,
+                               isolate->factory()->NewStringFromAsciiChecked(
+                                   kMethodName)));
+  }
+
+  size_t page_size = AllocatePageSize();
+  size_t new_committed_pages;
+  bool round_return_value =
+      RoundUpToPageSize(new_byte_length, page_size,
+                        JSArrayBuffer::kMaxByteLength, &new_committed_pages);
+  CHECK(round_return_value);
+
+  // [RAB] Let hostHandled be ? HostResizeArrayBuffer(O, newByteLength).
+  // [GSAB] Let hostHandled be ? HostGrowArrayBuffer(O, newByteLength).
+  // If hostHandled is handled, return undefined.
+
+  // TODO(v8:11111): Wasm integration.
+
+  if (!is_shared) {
+    // [RAB] Let oldBlock be O.[[ArrayBufferData]].
+    // [RAB] Let newBlock be ? CreateByteDataBlock(newByteLength).
+    // [RAB] Let copyLength be min(newByteLength, O.[[ArrayBufferByteLength]]).
+    // [RAB] Perform CopyDataBlockBytes(newBlock, 0, oldBlock, 0, copyLength).
+    // [RAB] NOTE: Neither creation of the new Data Block nor copying from the
+    // old Data Block are observable. Implementations reserve the right to
+    // implement this method as in-place growth or shrinkage.
+    if (array_buffer->GetBackingStore()->ResizeInPlace(
+            isolate, new_byte_length, new_committed_pages * page_size) !=
+        BackingStore::ResizeOrGrowResult::kSuccess) {
+      THROW_NEW_ERROR_RETURN_FAILURE(
+          isolate, NewRangeError(MessageTemplate::kOutOfMemory,
+                                 isolate->factory()->NewStringFromAsciiChecked(
+                                     kMethodName)));
+    }
+    // [RAB] Set O.[[ArrayBufferByteLength]] to newLength.
+    array_buffer->set_byte_length(new_byte_length);
+  } else {
+    // [GSAB] (Detailed description of the algorithm omitted.)
+    auto result = array_buffer->GetBackingStore()->GrowInPlace(
+        isolate, new_byte_length, new_committed_pages * page_size);
+    if (result == BackingStore::ResizeOrGrowResult::kFailure) {
+      THROW_NEW_ERROR_RETURN_FAILURE(
+          isolate, NewRangeError(MessageTemplate::kOutOfMemory,
+                                 isolate->factory()->NewStringFromAsciiChecked(
+                                     kMethodName)));
+    }
+    if (result == BackingStore::ResizeOrGrowResult::kRace) {
+      THROW_NEW_ERROR_RETURN_FAILURE(
+          isolate,
+          NewRangeError(
+              MessageTemplate::kInvalidArrayBufferResizeLength,
+              isolate->factory()->NewStringFromAsciiChecked(kMethodName)));
+    }
+    // Invariant: byte_length for a GSAB is 0 (it needs to be read from the
+    // BackingStore).
+    CHECK_EQ(0, array_buffer->byte_length());
+  }
+  return ReadOnlyRoots(isolate).undefined_value();
+}
+
+// ES #sec-get-growablesharedarraybuffer.prototype.bytelength
+// get GrowableSharedArrayBuffer.prototype.byteLength
+BUILTIN(GrowableSharedArrayBufferPrototypeGetByteLength) {
+  const char* const kMethodName =
+      "get GrowableSharedArrayBuffer.prototype.byteLength";
+  HandleScope scope(isolate);
+
+  // 1. Let O be the this value.
+  // 2. Perform ? RequireInternalSlot(O, [[ArrayBufferMaxLength]]).
+  CHECK_RECEIVER(JSArrayBuffer, array_buffer, kMethodName);
+  CHECK_RESIZABLE(true, array_buffer, kMethodName);
+  // 3. If IsSharedArrayBuffer(O) is false, throw a TypeError exception.
+  CHECK_SHARED(true, array_buffer, kMethodName);
+
+  // 4. Let length be ArrayBufferByteLength(O, SeqCst).
+
+  // Invariant: byte_length for GSAB is 0 (it needs to be read from the
+  // BackingStore).
+  DCHECK_EQ(0, array_buffer->byte_length());
+
+  size_t byte_length =
+      array_buffer->GetBackingStore()->byte_length(std::memory_order_seq_cst);
+
+  // 5. Return length.
+  return *isolate->factory()->NewNumberFromSize(byte_length);
+}
+
+// ES #sec-resizablearraybuffer.prototype.resize
+// ResizableArrayBuffer.prototype.resize(new_size))
+BUILTIN(ResizableArrayBufferPrototypeResize) {
+  const char* const kMethodName = "ResizableArrayBuffer.prototype.resize";
+  constexpr bool kIsShared = false;
+  return ResizeHelper(args, isolate, kMethodName, kIsShared);
+}
+
+// ES #sec-growablesharedarraybuffer.prototype.grow
+// GrowableSharedArrayBuffer.prototype.grow(new_size))
+BUILTIN(GrowableSharedArrayBufferPrototypeGrow) {
+  const char* const kMethodName = "GrowableSharedArrayBuffer.prototype.grow";
+  constexpr bool kIsShared = true;
+  return ResizeHelper(args, isolate, kMethodName, kIsShared);
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/builtins/builtins-async-function-gen.cc b/chromium/v8/src/builtins/builtins-async-function-gen.cc
index 49b00caa048..1644997ed01 100644
--- a/chromium/v8/src/builtins/builtins-async-function-gen.cc
+++ b/chromium/v8/src/builtins/builtins-async-function-gen.cc
@@ -157,12 +157,14 @@ TF_BUILTIN(AsyncFunctionEnter, AsyncFunctionBuiltinsAssembler) {
   StoreObjectFieldNoWriteBarrier(
       async_function_object, JSAsyncFunctionObject::kPromiseOffset, promise);
 
+  RunContextPromiseHookInit(context, promise, UndefinedConstant());
+
   // Fire promise hooks if enabled and push the Promise under construction
   // in an async function on the catch prediction stack to handle exceptions
   // thrown before the first await.
   Label if_instrumentation(this, Label::kDeferred),
       if_instrumentation_done(this);
-  Branch(IsPromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate(),
+  Branch(IsIsolatePromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate(),
          &if_instrumentation, &if_instrumentation_done);
   BIND(&if_instrumentation);
   {
diff --git a/chromium/v8/src/builtins/builtins-async-gen.cc b/chromium/v8/src/builtins/builtins-async-gen.cc
index 9ee6037b2bd..629f1e94fa4 100644
--- a/chromium/v8/src/builtins/builtins-async-gen.cc
+++ b/chromium/v8/src/builtins/builtins-async-gen.cc
@@ -97,18 +97,11 @@ TNode<Object> AsyncBuiltinsAssembler::AwaitOld(
 
   TVARIABLE(HeapObject, var_throwaway, UndefinedConstant());
 
-  // Deal with PromiseHooks and debug support in the runtime. This
-  // also allocates the throwaway promise, which is only needed in
-  // case of PromiseHooks or debugging.
-  Label if_debugging(this, Label::kDeferred), do_resolve_promise(this);
-  Branch(IsPromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate(),
-         &if_debugging, &do_resolve_promise);
-  BIND(&if_debugging);
-  var_throwaway =
-      CAST(CallRuntime(Runtime::kAwaitPromisesInitOld, context, value, promise,
-                       outer_promise, on_reject, is_predicted_as_caught));
-  Goto(&do_resolve_promise);
-  BIND(&do_resolve_promise);
+  RunContextPromiseHookInit(context, promise, outer_promise);
+
+  InitAwaitPromise(Runtime::kAwaitPromisesInitOld, context, value, promise,
+                   outer_promise, on_reject, is_predicted_as_caught,
+                   &var_throwaway);
 
   // Perform ! Call(promiseCapability.[[Resolve]], undefined, « promise »).
   CallBuiltin(Builtins::kResolvePromise, context, promise, value);
@@ -168,21 +161,46 @@ TNode<Object> AsyncBuiltinsAssembler::AwaitOptimized(
 
   TVARIABLE(HeapObject, var_throwaway, UndefinedConstant());
 
+  InitAwaitPromise(Runtime::kAwaitPromisesInit, context, promise, promise,
+                   outer_promise, on_reject, is_predicted_as_caught,
+                   &var_throwaway);
+
+  return CallBuiltin(Builtins::kPerformPromiseThen, native_context, promise,
+                     on_resolve, on_reject, var_throwaway.value());
+}
+
+void AsyncBuiltinsAssembler::InitAwaitPromise(
+    Runtime::FunctionId id, TNode<Context> context, TNode<Object> value,
+    TNode<Object> promise, TNode<Object> outer_promise,
+    TNode<HeapObject> on_reject, TNode<Oddball> is_predicted_as_caught,
+    TVariable<HeapObject>* var_throwaway) {
   // Deal with PromiseHooks and debug support in the runtime. This
   // also allocates the throwaway promise, which is only needed in
   // case of PromiseHooks or debugging.
-  Label if_debugging(this, Label::kDeferred), do_perform_promise_then(this);
-  Branch(IsPromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate(),
-         &if_debugging, &do_perform_promise_then);
+  Label if_debugging(this, Label::kDeferred),
+      if_promise_hook(this, Label::kDeferred),
+      not_debugging(this),
+      do_nothing(this);
+  TNode<Uint32T> promiseHookFlags = PromiseHookFlags();
+  Branch(IsIsolatePromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate(
+      promiseHookFlags), &if_debugging, &not_debugging);
   BIND(&if_debugging);
-  var_throwaway =
-      CAST(CallRuntime(Runtime::kAwaitPromisesInit, context, promise, promise,
+  *var_throwaway =
+      CAST(CallRuntime(id, context, value, promise,
                        outer_promise, on_reject, is_predicted_as_caught));
-  Goto(&do_perform_promise_then);
-  BIND(&do_perform_promise_then);
-
-  return CallBuiltin(Builtins::kPerformPromiseThen, native_context, promise,
-                     on_resolve, on_reject, var_throwaway.value());
+  Goto(&do_nothing);
+  BIND(&not_debugging);
+
+  // This call to NewJSPromise is to keep behaviour parity with what happens
+  // in Runtime::kAwaitPromisesInit above if native hooks are set. It will
+  // create a throwaway promise that will trigger an init event and will get
+  // passed into Builtins::kPerformPromiseThen below.
+  Branch(IsContextPromiseHookEnabled(promiseHookFlags), &if_promise_hook,
+         &do_nothing);
+  BIND(&if_promise_hook);
+  *var_throwaway = NewJSPromise(context, promise);
+  Goto(&do_nothing);
+  BIND(&do_nothing);
 }
 
 TNode<Object> AsyncBuiltinsAssembler::Await(
diff --git a/chromium/v8/src/builtins/builtins-async-gen.h b/chromium/v8/src/builtins/builtins-async-gen.h
index 833e78d45d5..34b7a0ce1d6 100644
--- a/chromium/v8/src/builtins/builtins-async-gen.h
+++ b/chromium/v8/src/builtins/builtins-async-gen.h
@@ -62,6 +62,12 @@ class AsyncBuiltinsAssembler : public PromiseBuiltinsAssembler {
                                TNode<SharedFunctionInfo> on_resolve_sfi,
                                TNode<SharedFunctionInfo> on_reject_sfi,
                                TNode<Oddball> is_predicted_as_caught);
+
+  void InitAwaitPromise(
+      Runtime::FunctionId id, TNode<Context> context, TNode<Object> value,
+      TNode<Object> promise, TNode<Object> outer_promise,
+      TNode<HeapObject> on_reject, TNode<Oddball> is_predicted_as_caught,
+      TVariable<HeapObject>* var_throwaway);
 };
 
 }  // namespace internal
diff --git a/chromium/v8/src/builtins/builtins-async-generator-gen.cc b/chromium/v8/src/builtins/builtins-async-generator-gen.cc
index 03df9e307c7..0e94fd20939 100644
--- a/chromium/v8/src/builtins/builtins-async-generator-gen.cc
+++ b/chromium/v8/src/builtins/builtins-async-generator-gen.cc
@@ -518,7 +518,7 @@ TF_BUILTIN(AsyncGeneratorResolve, AsyncGeneratorBuiltinsAssembler) {
   // the "promiseResolve" hook would not be fired otherwise.
   Label if_fast(this), if_slow(this, Label::kDeferred), return_promise(this);
   GotoIfForceSlowPath(&if_slow);
-  GotoIf(IsPromiseHookEnabled(), &if_slow);
+  GotoIf(IsIsolatePromiseHookEnabledOrHasAsyncEventDelegate(), &if_slow);
   Branch(IsPromiseThenProtectorCellInvalid(), &if_slow, &if_fast);
 
   BIND(&if_fast);
diff --git a/chromium/v8/src/builtins/builtins-call-gen.cc b/chromium/v8/src/builtins/builtins-call-gen.cc
index 664f57aadb2..89bf77d0b07 100644
--- a/chromium/v8/src/builtins/builtins-call-gen.cc
+++ b/chromium/v8/src/builtins/builtins-call-gen.cc
@@ -64,38 +64,45 @@ void Builtins::Generate_CallFunctionForwardVarargs(MacroAssembler* masm) {
       masm->isolate()->builtins()->CallFunction());
 }
 
+// TODO(cbruni): Try reusing code between builtin versions to avoid binary
+// overhead.
+TF_BUILTIN(Call_ReceiverIsNullOrUndefined_Baseline_Compact,
+           CallOrConstructBuiltinsAssembler) {
+  auto receiver = UndefinedConstant();
+  CallReceiver<Descriptor>(Builtins::kCall_ReceiverIsNullOrUndefined, receiver);
+}
+
 TF_BUILTIN(Call_ReceiverIsNullOrUndefined_Baseline,
            CallOrConstructBuiltinsAssembler) {
-  auto target = Parameter<Object>(Descriptor::kFunction);
   auto argc = UncheckedParameter<Int32T>(Descriptor::kActualArgumentsCount);
-  auto context = LoadContextFromBaseline();
-  auto feedback_vector = LoadFeedbackVectorFromBaseline();
   auto slot = UncheckedParameter<UintPtrT>(Descriptor::kSlot);
-  CollectCallFeedback(target, context, feedback_vector, slot);
-  TailCallBuiltin(Builtins::kCall_ReceiverIsNullOrUndefined, context, target,
-                  argc);
+  auto receiver = UndefinedConstant();
+  CallReceiver<Descriptor>(Builtins::kCall_ReceiverIsNullOrUndefined, argc,
+                           slot, receiver);
+}
+
+TF_BUILTIN(Call_ReceiverIsNotNullOrUndefined_Baseline_Compact,
+           CallOrConstructBuiltinsAssembler) {
+  CallReceiver<Descriptor>(Builtins::kCall_ReceiverIsNotNullOrUndefined);
 }
 
 TF_BUILTIN(Call_ReceiverIsNotNullOrUndefined_Baseline,
            CallOrConstructBuiltinsAssembler) {
-  auto target = Parameter<Object>(Descriptor::kFunction);
   auto argc = UncheckedParameter<Int32T>(Descriptor::kActualArgumentsCount);
-  auto context = LoadContextFromBaseline();
-  auto feedback_vector = LoadFeedbackVectorFromBaseline();
   auto slot = UncheckedParameter<UintPtrT>(Descriptor::kSlot);
-  CollectCallFeedback(target, context, feedback_vector, slot);
-  TailCallBuiltin(Builtins::kCall_ReceiverIsNotNullOrUndefined, context, target,
-                  argc);
+  CallReceiver<Descriptor>(Builtins::kCall_ReceiverIsNotNullOrUndefined, argc,
+                           slot);
+}
+
+TF_BUILTIN(Call_ReceiverIsAny_Baseline_Compact,
+           CallOrConstructBuiltinsAssembler) {
+  CallReceiver<Descriptor>(Builtins::kCall_ReceiverIsAny);
 }
 
 TF_BUILTIN(Call_ReceiverIsAny_Baseline, CallOrConstructBuiltinsAssembler) {
-  auto target = Parameter<Object>(Descriptor::kFunction);
   auto argc = UncheckedParameter<Int32T>(Descriptor::kActualArgumentsCount);
-  auto context = LoadContextFromBaseline();
-  auto feedback_vector = LoadFeedbackVectorFromBaseline();
   auto slot = UncheckedParameter<UintPtrT>(Descriptor::kSlot);
-  CollectCallFeedback(target, context, feedback_vector, slot);
-  TailCallBuiltin(Builtins::kCall_ReceiverIsAny, context, target, argc);
+  CallReceiver<Descriptor>(Builtins::kCall_ReceiverIsAny, argc, slot);
 }
 
 TF_BUILTIN(Call_ReceiverIsNullOrUndefined_WithFeedback,
@@ -105,7 +112,9 @@ TF_BUILTIN(Call_ReceiverIsNullOrUndefined_WithFeedback,
   auto context = Parameter<Context>(Descriptor::kContext);
   auto feedback_vector = Parameter<FeedbackVector>(Descriptor::kFeedbackVector);
   auto slot = UncheckedParameter<UintPtrT>(Descriptor::kSlot);
-  CollectCallFeedback(target, context, feedback_vector, slot);
+  auto receiver = Parameter<Object>(Descriptor::kReceiver);
+  CollectCallFeedback(
+      target, [=] { return receiver; }, context, feedback_vector, slot);
   TailCallBuiltin(Builtins::kCall_ReceiverIsNullOrUndefined, context, target,
                   argc);
 }
@@ -117,7 +126,9 @@ TF_BUILTIN(Call_ReceiverIsNotNullOrUndefined_WithFeedback,
   auto context = Parameter<Context>(Descriptor::kContext);
   auto feedback_vector = Parameter<FeedbackVector>(Descriptor::kFeedbackVector);
   auto slot = UncheckedParameter<UintPtrT>(Descriptor::kSlot);
-  CollectCallFeedback(target, context, feedback_vector, slot);
+  auto receiver = Parameter<Object>(Descriptor::kReceiver);
+  CollectCallFeedback(
+      target, [=] { return receiver; }, context, feedback_vector, slot);
   TailCallBuiltin(Builtins::kCall_ReceiverIsNotNullOrUndefined, context, target,
                   argc);
 }
@@ -128,7 +139,9 @@ TF_BUILTIN(Call_ReceiverIsAny_WithFeedback, CallOrConstructBuiltinsAssembler) {
   auto context = Parameter<Context>(Descriptor::kContext);
   auto feedback_vector = Parameter<FeedbackVector>(Descriptor::kFeedbackVector);
   auto slot = UncheckedParameter<UintPtrT>(Descriptor::kSlot);
-  CollectCallFeedback(target, context, feedback_vector, slot);
+  auto receiver = Parameter<Object>(Descriptor::kReceiver);
+  CollectCallFeedback(
+      target, [=] { return receiver; }, context, feedback_vector, slot);
   TailCallBuiltin(Builtins::kCall_ReceiverIsAny, context, target, argc);
 }
 
@@ -449,6 +462,43 @@ void CallOrConstructBuiltinsAssembler::CallOrConstructWithSpread(
   }
 }
 
+template <class Descriptor>
+void CallOrConstructBuiltinsAssembler::CallReceiver(
+    Builtins::Name id, base::Optional<TNode<Object>> receiver) {
+  static_assert(std::is_same<Descriptor,
+                             CallTrampoline_Baseline_CompactDescriptor>::value,
+                "Incompatible Descriptor");
+  auto bitfield = UncheckedParameter<Word32T>(Descriptor::kBitField);
+  TNode<Int32T> argc =
+      Signed(DecodeWord32<
+             CallTrampoline_Baseline_CompactDescriptor::ArgumentCountField>(
+          bitfield));
+  TNode<UintPtrT> slot = ChangeUint32ToWord(
+      DecodeWord32<CallTrampoline_Baseline_CompactDescriptor::SlotField>(
+          bitfield));
+  CallReceiver<Descriptor>(id, argc, slot, receiver);
+}
+
+template <class Descriptor>
+void CallOrConstructBuiltinsAssembler::CallReceiver(
+    Builtins::Name id, TNode<Int32T> argc, TNode<UintPtrT> slot,
+    base::Optional<TNode<Object>> maybe_receiver) {
+  auto target = Parameter<Object>(Descriptor::kFunction);
+  auto context = LoadContextFromBaseline();
+  auto feedback_vector = LoadFeedbackVectorFromBaseline();
+  LazyNode<Object> receiver = [=] {
+    if (maybe_receiver) {
+      return *maybe_receiver;
+    } else {
+      CodeStubArguments args(this, argc);
+      return args.GetReceiver();
+    }
+  };
+
+  CollectCallFeedback(target, receiver, context, feedback_vector, slot);
+  TailCallBuiltin(id, context, target, argc);
+}
+
 TF_BUILTIN(CallWithArrayLike, CallOrConstructBuiltinsAssembler) {
   auto target = Parameter<Object>(Descriptor::kTarget);
   base::Optional<TNode<Object>> new_target = base::nullopt;
@@ -464,7 +514,9 @@ TF_BUILTIN(CallWithArrayLike_WithFeedback, CallOrConstructBuiltinsAssembler) {
   auto context = Parameter<Context>(Descriptor::kContext);
   auto feedback_vector = Parameter<FeedbackVector>(Descriptor::kFeedbackVector);
   auto slot = UncheckedParameter<UintPtrT>(Descriptor::kSlot);
-  CollectCallFeedback(target, context, feedback_vector, slot);
+  auto receiver = Parameter<Object>(Descriptor::kReceiver);
+  CollectCallFeedback(
+      target, [=] { return receiver; }, context, feedback_vector, slot);
   CallOrConstructWithArrayLike(target, new_target, arguments_list, context);
 }
 
@@ -485,7 +537,10 @@ TF_BUILTIN(CallWithSpread_Baseline, CallOrConstructBuiltinsAssembler) {
   auto context = LoadContextFromBaseline();
   auto feedback_vector = LoadFeedbackVectorFromBaseline();
   auto slot = UncheckedParameter<UintPtrT>(Descriptor::kSlot);
-  CollectCallFeedback(target, context, feedback_vector, slot);
+  CodeStubArguments args(this, args_count);
+  CollectCallFeedback(
+      target, [=] { return args.GetReceiver(); }, context, feedback_vector,
+      slot);
   CallOrConstructWithSpread(target, new_target, spread, args_count, context);
 }
 
@@ -497,7 +552,9 @@ TF_BUILTIN(CallWithSpread_WithFeedback, CallOrConstructBuiltinsAssembler) {
   auto context = Parameter<Context>(Descriptor::kContext);
   auto feedback_vector = Parameter<FeedbackVector>(Descriptor::kFeedbackVector);
   auto slot = UncheckedParameter<UintPtrT>(Descriptor::kSlot);
-  CollectCallFeedback(target, context, feedback_vector, slot);
+  auto receiver = Parameter<Object>(Descriptor::kReceiver);
+  CollectCallFeedback(
+      target, [=] { return receiver; }, context, feedback_vector, slot);
   CallOrConstructWithSpread(target, new_target, spread, args_count, context);
 }
 
diff --git a/chromium/v8/src/builtins/builtins-call-gen.h b/chromium/v8/src/builtins/builtins-call-gen.h
index c938662d5e5..ff4d998ff3a 100644
--- a/chromium/v8/src/builtins/builtins-call-gen.h
+++ b/chromium/v8/src/builtins/builtins-call-gen.h
@@ -30,6 +30,13 @@ class CallOrConstructBuiltinsAssembler : public CodeStubAssembler {
                                  TNode<Object> spread, TNode<Int32T> args_count,
                                  TNode<Context> context);
 
+  template <class Descriptor>
+  void CallReceiver(Builtins::Name id,
+                    base::Optional<TNode<Object>> = base::nullopt);
+  template <class Descriptor>
+  void CallReceiver(Builtins::Name id, TNode<Int32T> argc, TNode<UintPtrT> slot,
+                    base::Optional<TNode<Object>> = base::nullopt);
+
   enum class CallFunctionTemplateMode : uint8_t {
     kCheckAccess,
     kCheckCompatibleReceiver,
diff --git a/chromium/v8/src/builtins/builtins-debug-gen.cc b/chromium/v8/src/builtins/builtins-debug-gen.cc
deleted file mode 100644
index 9d47cf16006..00000000000
--- a/chromium/v8/src/builtins/builtins-debug-gen.cc
+++ /dev/null
@@ -1,22 +0,0 @@
-// Copyright 2016 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "src/builtins/builtins-utils.h"
-#include "src/builtins/builtins.h"
-#include "src/debug/debug.h"
-#include "src/objects/objects-inl.h"
-
-namespace v8 {
-namespace internal {
-
-void Builtins::Generate_FrameDropperTrampoline(MacroAssembler* masm) {
-  DebugCodegen::GenerateFrameDropperTrampoline(masm);
-}
-
-void Builtins::Generate_HandleDebuggerStatement(MacroAssembler* masm) {
-  DebugCodegen::GenerateHandleDebuggerStatement(masm);
-}
-
-}  // namespace internal
-}  // namespace v8
diff --git a/chromium/v8/src/builtins/builtins-definitions.h b/chromium/v8/src/builtins/builtins-definitions.h
index b0e608418eb..78255a30e93 100644
--- a/chromium/v8/src/builtins/builtins-definitions.h
+++ b/chromium/v8/src/builtins/builtins-definitions.h
@@ -50,8 +50,13 @@ namespace internal {
   ASM(Call_ReceiverIsNullOrUndefined, CallTrampoline)                          \
   ASM(Call_ReceiverIsNotNullOrUndefined, CallTrampoline)                       \
   ASM(Call_ReceiverIsAny, CallTrampoline)                                      \
+  TFC(Call_ReceiverIsNullOrUndefined_Baseline_Compact,                         \
+      CallTrampoline_Baseline_Compact)                                         \
   TFC(Call_ReceiverIsNullOrUndefined_Baseline, CallTrampoline_Baseline)        \
+  TFC(Call_ReceiverIsNotNullOrUndefined_Baseline_Compact,                      \
+      CallTrampoline_Baseline_Compact)                                         \
   TFC(Call_ReceiverIsNotNullOrUndefined_Baseline, CallTrampoline_Baseline)     \
+  TFC(Call_ReceiverIsAny_Baseline_Compact, CallTrampoline_Baseline_Compact)    \
   TFC(Call_ReceiverIsAny_Baseline, CallTrampoline_Baseline)                    \
   TFC(Call_ReceiverIsNullOrUndefined_WithFeedback,                             \
       CallTrampoline_WithFeedback)                                             \
@@ -133,13 +138,13 @@ namespace internal {
       InterpreterPushArgsThenConstruct)                                        \
   ASM(InterpreterPushArgsThenConstructWithFinalSpread,                         \
       InterpreterPushArgsThenConstruct)                                        \
-  ASM(InterpreterEnterBytecodeAdvance, Dummy)                                  \
-  ASM(InterpreterEnterBytecodeDispatch, Dummy)                                 \
+  ASM(InterpreterEnterAtBytecode, Dummy)                                       \
+  ASM(InterpreterEnterAtNextBytecode, Dummy)                                   \
   ASM(InterpreterOnStackReplacement, ContextOnly)                              \
                                                                                \
   /* Baseline Compiler */                                                      \
   ASM(BaselineOutOfLinePrologue, BaselineOutOfLinePrologue)                    \
-  ASM(BaselineOnStackReplacement, ContextOnly)                                 \
+  ASM(BaselineOnStackReplacement, Void)                                        \
   ASM(BaselineLeaveFrame, BaselineLeaveFrame)                                  \
   ASM(BaselineEnterAtBytecode, Void)                                           \
   ASM(BaselineEnterAtNextBytecode, Void)                                       \
@@ -200,8 +205,6 @@ namespace internal {
                                                                                \
   /* Debugger */                                                               \
   TFJ(DebugBreakTrampoline, kDontAdaptArgumentsSentinel)                       \
-  ASM(FrameDropperTrampoline, FrameDropperTrampoline)                          \
-  ASM(HandleDebuggerStatement, ContextOnly)                                    \
                                                                                \
   /* Type conversions */                                                       \
   TFC(ToNumber, TypeConversion)                                                \
@@ -770,6 +773,11 @@ namespace internal {
   ASM(RegExpInterpreterTrampoline, CCall)                                      \
   ASM(RegExpExperimentalTrampoline, CCall)                                     \
                                                                                \
+  /* ResizableArrayBuffer & GrowableSharedArrayBuffer */                       \
+  CPP(ResizableArrayBufferPrototypeResize)                                     \
+  CPP(GrowableSharedArrayBufferPrototypeGrow)                                  \
+  CPP(GrowableSharedArrayBufferPrototypeGetByteLength)                         \
+                                                                               \
   /* Set */                                                                    \
   TFJ(SetConstructor, kDontAdaptArgumentsSentinel)                             \
   TFJ(SetPrototypeHas, 1, kReceiver, kKey)                                     \
@@ -863,6 +871,7 @@ namespace internal {
   IF_WASM(ASM, GenericJSToWasmWrapper, Dummy)                                  \
   IF_WASM(ASM, WasmCompileLazy, Dummy)                                         \
   IF_WASM(ASM, WasmDebugBreak, Dummy)                                          \
+  IF_WASM(ASM, WasmOnStackReplace, Dummy)                                      \
   IF_WASM(TFC, WasmFloat32ToNumber, WasmFloat32ToNumber)                       \
   IF_WASM(TFC, WasmFloat64ToNumber, WasmFloat64ToNumber)                       \
   IF_WASM(TFC, WasmI32AtomicWait32, WasmI32AtomicWait32)                       \
@@ -983,6 +992,7 @@ namespace internal {
   CPP(CollatorPrototypeCompare)                                        \
   /* ecma402 #sec-intl.collator.supportedlocalesof */                  \
   CPP(CollatorSupportedLocalesOf)                                      \
+  /* ecma402 #sec-intl.collator.prototype.resolvedoptions */           \
   CPP(CollatorPrototypeResolvedOptions)                                \
   /* ecma402 #sup-date.prototype.tolocaledatestring */                 \
   CPP(DatePrototypeToLocaleDateString)                                 \
@@ -1028,21 +1038,46 @@ namespace internal {
   CPP(ListFormatSupportedLocalesOf)                                    \
   /* ecma402 #sec-intl-locale-constructor */                           \
   CPP(LocaleConstructor)                                               \
+  /* ecma402 #sec-Intl.Locale.prototype.baseName */                    \
   CPP(LocalePrototypeBaseName)                                         \
+  /* ecma402 #sec-Intl.Locale.prototype.calendar */                    \
   CPP(LocalePrototypeCalendar)                                         \
+  /* ecma402 #sec-Intl.Locale.prototype.calendars */                   \
+  CPP(LocalePrototypeCalendars)                                        \
+  /* ecma402 #sec-Intl.Locale.prototype.caseFirst */                   \
   CPP(LocalePrototypeCaseFirst)                                        \
+  /* ecma402 #sec-Intl.Locale.prototype.collation */                   \
   CPP(LocalePrototypeCollation)                                        \
+  /* ecma402 #sec-Intl.Locale.prototype.collations */                  \
+  CPP(LocalePrototypeCollations)                                       \
+  /* ecma402 #sec-Intl.Locale.prototype.hourCycle */                   \
   CPP(LocalePrototypeHourCycle)                                        \
+  /* ecma402 #sec-Intl.Locale.prototype.hourCycles */                  \
+  CPP(LocalePrototypeHourCycles)                                       \
+  /* ecma402 #sec-Intl.Locale.prototype.language */                    \
   CPP(LocalePrototypeLanguage)                                         \
   /* ecma402 #sec-Intl.Locale.prototype.maximize */                    \
   CPP(LocalePrototypeMaximize)                                         \
   /* ecma402 #sec-Intl.Locale.prototype.minimize */                    \
   CPP(LocalePrototypeMinimize)                                         \
+  /* ecma402 #sec-Intl.Locale.prototype.numeric */                     \
   CPP(LocalePrototypeNumeric)                                          \
+  /* ecma402 #sec-Intl.Locale.prototype.numberingSystem */             \
   CPP(LocalePrototypeNumberingSystem)                                  \
+  /* ecma402 #sec-Intl.Locale.prototype.numberingSystems */            \
+  CPP(LocalePrototypeNumberingSystems)                                 \
+  /* ecma402 #sec-Intl.Locale.prototype.region */                      \
   CPP(LocalePrototypeRegion)                                           \
+  /* ecma402 #sec-Intl.Locale.prototype.script */                      \
   CPP(LocalePrototypeScript)                                           \
+  /* ecma402 #sec-Intl.Locale.prototype.textInfo */                    \
+  CPP(LocalePrototypeTextInfo)                                         \
+  /* ecma402 #sec-Intl.Locale.prototype.timezones */                   \
+  CPP(LocalePrototypeTimeZones)                                        \
+  /* ecma402 #sec-Intl.Locale.prototype.toString */                    \
   CPP(LocalePrototypeToString)                                         \
+  /* ecma402 #sec-Intl.Locale.prototype.weekInfo */                    \
+  CPP(LocalePrototypeWeekInfo)                                         \
   /* ecma402 #sec-intl.numberformat */                                 \
   CPP(NumberFormatConstructor)                                         \
   /* ecma402 #sec-number-format-functions */                           \
@@ -1057,6 +1092,7 @@ namespace internal {
   CPP(NumberFormatSupportedLocalesOf)                                  \
   /* ecma402 #sec-intl.pluralrules */                                  \
   CPP(PluralRulesConstructor)                                          \
+  /* ecma402 #sec-intl.pluralrules.prototype.resolvedoptions */        \
   CPP(PluralRulesPrototypeResolvedOptions)                             \
   /* ecma402 #sec-intl.pluralrules.prototype.select */                 \
   CPP(PluralRulesPrototypeSelect)                                      \
diff --git a/chromium/v8/src/builtins/builtins-error.cc b/chromium/v8/src/builtins/builtins-error.cc
index 840298eacbf..44dce9224a3 100644
--- a/chromium/v8/src/builtins/builtins-error.cc
+++ b/chromium/v8/src/builtins/builtins-error.cc
@@ -18,9 +18,12 @@ namespace internal {
 // ES6 section 19.5.1.1 Error ( message )
 BUILTIN(ErrorConstructor) {
   HandleScope scope(isolate);
+  Handle<Object> options = FLAG_harmony_error_cause
+                               ? args.atOrUndefined(isolate, 2)
+                               : isolate->factory()->undefined_value();
   RETURN_RESULT_OR_FAILURE(
       isolate, ErrorUtils::Construct(isolate, args.target(), args.new_target(),
-                                     args.atOrUndefined(isolate, 1)));
+                                     args.atOrUndefined(isolate, 1), options));
 }
 
 // static
diff --git a/chromium/v8/src/builtins/builtins-generator-gen.cc b/chromium/v8/src/builtins/builtins-generator-gen.cc
index 2e9d7e24e4f..b2d6e223e16 100644
--- a/chromium/v8/src/builtins/builtins-generator-gen.cc
+++ b/chromium/v8/src/builtins/builtins-generator-gen.cc
@@ -205,7 +205,7 @@ TF_BUILTIN(GeneratorPrototypeThrow, GeneratorBuiltinsAssembler) {
 // TODO(cbruni): Merge with corresponding bytecode handler.
 TF_BUILTIN(SuspendGeneratorBaseline, GeneratorBuiltinsAssembler) {
   auto generator = Parameter<JSGeneratorObject>(Descriptor::kGeneratorObject);
-  auto context = Parameter<Context>(Descriptor::kContext);
+  auto context = LoadContextFromBaseline();
   StoreJSGeneratorObjectContext(generator, context);
   auto suspend_id = SmiTag(UncheckedParameter<IntPtrT>(Descriptor::kSuspendId));
   StoreJSGeneratorObjectContinuation(generator, suspend_id);
diff --git a/chromium/v8/src/builtins/builtins-handler-gen.cc b/chromium/v8/src/builtins/builtins-handler-gen.cc
index 3cbd626b8e4..19a31b81a7c 100644
--- a/chromium/v8/src/builtins/builtins-handler-gen.cc
+++ b/chromium/v8/src/builtins/builtins-handler-gen.cc
@@ -183,28 +183,39 @@ TF_BUILTIN(ElementsTransitionAndStore_NoTransitionHandleCOW,
 
 // All elements kinds handled by EmitElementStore. Specifically, this includes
 // fast elements and fixed typed array elements.
-#define ELEMENTS_KINDS(V)          \
-  V(PACKED_SMI_ELEMENTS)           \
-  V(HOLEY_SMI_ELEMENTS)            \
-  V(PACKED_ELEMENTS)               \
-  V(PACKED_NONEXTENSIBLE_ELEMENTS) \
-  V(PACKED_SEALED_ELEMENTS)        \
-  V(HOLEY_ELEMENTS)                \
-  V(HOLEY_NONEXTENSIBLE_ELEMENTS)  \
-  V(HOLEY_SEALED_ELEMENTS)         \
-  V(PACKED_DOUBLE_ELEMENTS)        \
-  V(HOLEY_DOUBLE_ELEMENTS)         \
-  V(UINT8_ELEMENTS)                \
-  V(INT8_ELEMENTS)                 \
-  V(UINT16_ELEMENTS)               \
-  V(INT16_ELEMENTS)                \
-  V(UINT32_ELEMENTS)               \
-  V(INT32_ELEMENTS)                \
-  V(FLOAT32_ELEMENTS)              \
-  V(FLOAT64_ELEMENTS)              \
-  V(UINT8_CLAMPED_ELEMENTS)        \
-  V(BIGUINT64_ELEMENTS)            \
-  V(BIGINT64_ELEMENTS)
+#define ELEMENTS_KINDS(V)            \
+  V(PACKED_SMI_ELEMENTS)             \
+  V(HOLEY_SMI_ELEMENTS)              \
+  V(PACKED_ELEMENTS)                 \
+  V(PACKED_NONEXTENSIBLE_ELEMENTS)   \
+  V(PACKED_SEALED_ELEMENTS)          \
+  V(HOLEY_ELEMENTS)                  \
+  V(HOLEY_NONEXTENSIBLE_ELEMENTS)    \
+  V(HOLEY_SEALED_ELEMENTS)           \
+  V(PACKED_DOUBLE_ELEMENTS)          \
+  V(HOLEY_DOUBLE_ELEMENTS)           \
+  V(UINT8_ELEMENTS)                  \
+  V(INT8_ELEMENTS)                   \
+  V(UINT16_ELEMENTS)                 \
+  V(INT16_ELEMENTS)                  \
+  V(UINT32_ELEMENTS)                 \
+  V(INT32_ELEMENTS)                  \
+  V(FLOAT32_ELEMENTS)                \
+  V(FLOAT64_ELEMENTS)                \
+  V(UINT8_CLAMPED_ELEMENTS)          \
+  V(BIGUINT64_ELEMENTS)              \
+  V(BIGINT64_ELEMENTS)               \
+  V(RAB_GSAB_UINT8_ELEMENTS)         \
+  V(RAB_GSAB_INT8_ELEMENTS)          \
+  V(RAB_GSAB_UINT16_ELEMENTS)        \
+  V(RAB_GSAB_INT16_ELEMENTS)         \
+  V(RAB_GSAB_UINT32_ELEMENTS)        \
+  V(RAB_GSAB_INT32_ELEMENTS)         \
+  V(RAB_GSAB_FLOAT32_ELEMENTS)       \
+  V(RAB_GSAB_FLOAT64_ELEMENTS)       \
+  V(RAB_GSAB_UINT8_CLAMPED_ELEMENTS) \
+  V(RAB_GSAB_BIGUINT64_ELEMENTS)     \
+  V(RAB_GSAB_BIGINT64_ELEMENTS)
 
 void HandlerBuiltinsAssembler::DispatchByElementsKind(
     TNode<Int32T> elements_kind, const ElementsKindSwitchCase& case_function,
diff --git a/chromium/v8/src/builtins/builtins-ic-gen.cc b/chromium/v8/src/builtins/builtins-ic-gen.cc
index 81bf6379ece..e172b5a129b 100644
--- a/chromium/v8/src/builtins/builtins-ic-gen.cc
+++ b/chromium/v8/src/builtins/builtins-ic-gen.cc
@@ -10,70 +10,221 @@
 namespace v8 {
 namespace internal {
 
-#define IC_BUILTIN(Name)                                                \
-  void Builtins::Generate_##Name(compiler::CodeAssemblerState* state) { \
-    AccessorAssembler assembler(state);                                 \
-    assembler.Generate##Name();                                         \
-  }
+void Builtins::Generate_LoadIC(compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLoadIC();
+}
+void Builtins::Generate_LoadIC_Megamorphic(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLoadIC_Megamorphic();
+}
+void Builtins::Generate_LoadIC_Noninlined(compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLoadIC_Noninlined();
+}
+void Builtins::Generate_LoadIC_NoFeedback(compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLoadIC_NoFeedback();
+}
+void Builtins::Generate_LoadICTrampoline(compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLoadICTrampoline();
+}
+void Builtins::Generate_LoadICBaseline(compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLoadICBaseline();
+}
+void Builtins::Generate_LoadICTrampoline_Megamorphic(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLoadICTrampoline_Megamorphic();
+}
+void Builtins::Generate_LoadSuperIC(compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLoadSuperIC();
+}
+void Builtins::Generate_LoadSuperICBaseline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLoadSuperICBaseline();
+}
+void Builtins::Generate_KeyedLoadIC(compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateKeyedLoadIC();
+}
+void Builtins::Generate_KeyedLoadIC_Megamorphic(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateKeyedLoadIC_Megamorphic();
+}
+void Builtins::Generate_KeyedLoadIC_PolymorphicName(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateKeyedLoadIC_PolymorphicName();
+}
+void Builtins::Generate_KeyedLoadICTrampoline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateKeyedLoadICTrampoline();
+}
+void Builtins::Generate_KeyedLoadICBaseline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateKeyedLoadICBaseline();
+}
+void Builtins::Generate_KeyedLoadICTrampoline_Megamorphic(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateKeyedLoadICTrampoline_Megamorphic();
+}
+void Builtins::Generate_LoadGlobalIC_NoFeedback(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLoadGlobalIC_NoFeedback();
+}
+void Builtins::Generate_StoreGlobalIC(compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateStoreGlobalIC();
+}
+void Builtins::Generate_StoreGlobalICTrampoline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateStoreGlobalICTrampoline();
+}
+void Builtins::Generate_StoreGlobalICBaseline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateStoreGlobalICBaseline();
+}
+void Builtins::Generate_StoreIC(compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateStoreIC();
+}
+void Builtins::Generate_StoreICTrampoline(compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateStoreICTrampoline();
+}
+void Builtins::Generate_StoreICBaseline(compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateStoreICBaseline();
+}
+void Builtins::Generate_KeyedStoreIC(compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateKeyedStoreIC();
+}
+void Builtins::Generate_KeyedStoreICTrampoline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateKeyedStoreICTrampoline();
+}
+void Builtins::Generate_KeyedStoreICBaseline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateKeyedStoreICBaseline();
+}
+void Builtins::Generate_StoreInArrayLiteralIC(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateStoreInArrayLiteralIC();
+}
+void Builtins::Generate_StoreInArrayLiteralICBaseline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateStoreInArrayLiteralICBaseline();
+}
+void Builtins::Generate_CloneObjectIC(compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateCloneObjectIC();
+}
+void Builtins::Generate_CloneObjectICBaseline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateCloneObjectICBaseline();
+}
+void Builtins::Generate_CloneObjectIC_Slow(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateCloneObjectIC_Slow();
+}
+void Builtins::Generate_KeyedHasIC(compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateKeyedHasIC();
+}
+void Builtins::Generate_KeyedHasICBaseline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateKeyedHasICBaseline();
+}
+void Builtins::Generate_KeyedHasIC_Megamorphic(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateKeyedHasIC_Megamorphic();
+}
+void Builtins::Generate_KeyedHasIC_PolymorphicName(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateKeyedHasIC_PolymorphicName();
+}
+
+void Builtins::Generate_LoadGlobalIC(compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLoadGlobalIC(TypeofMode::kNotInside);
+}
 
-#define IC_BUILTIN_PARAM(BuiltinName, GeneratorName, parameter)                \
-  void Builtins::Generate_##BuiltinName(compiler::CodeAssemblerState* state) { \
-    AccessorAssembler assembler(state);                                        \
-    assembler.Generate##GeneratorName(parameter);                              \
-  }
+void Builtins::Generate_LoadGlobalICInsideTypeof(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLoadGlobalIC(TypeofMode::kInside);
+}
 
-IC_BUILTIN(LoadIC)
-IC_BUILTIN(LoadIC_Megamorphic)
-IC_BUILTIN(LoadIC_Noninlined)
-IC_BUILTIN(LoadIC_NoFeedback)
-IC_BUILTIN(LoadICTrampoline)
-IC_BUILTIN(LoadICBaseline)
-IC_BUILTIN(LoadICTrampoline_Megamorphic)
-IC_BUILTIN(LoadSuperIC)
-IC_BUILTIN(LoadSuperICBaseline)
-IC_BUILTIN(KeyedLoadIC)
-IC_BUILTIN(KeyedLoadIC_Megamorphic)
-IC_BUILTIN(KeyedLoadIC_PolymorphicName)
-IC_BUILTIN(KeyedLoadICTrampoline)
-IC_BUILTIN(KeyedLoadICBaseline)
-IC_BUILTIN(KeyedLoadICTrampoline_Megamorphic)
-IC_BUILTIN(LoadGlobalIC_NoFeedback)
-IC_BUILTIN(StoreGlobalIC)
-IC_BUILTIN(StoreGlobalICTrampoline)
-IC_BUILTIN(StoreGlobalICBaseline)
-IC_BUILTIN(StoreIC)
-IC_BUILTIN(StoreICTrampoline)
-IC_BUILTIN(StoreICBaseline)
-IC_BUILTIN(KeyedStoreIC)
-IC_BUILTIN(KeyedStoreICTrampoline)
-IC_BUILTIN(KeyedStoreICBaseline)
-IC_BUILTIN(StoreInArrayLiteralIC)
-IC_BUILTIN(StoreInArrayLiteralICBaseline)
-IC_BUILTIN(CloneObjectIC)
-IC_BUILTIN(CloneObjectICBaseline)
-IC_BUILTIN(CloneObjectIC_Slow)
-IC_BUILTIN(KeyedHasIC)
-IC_BUILTIN(KeyedHasICBaseline)
-IC_BUILTIN(KeyedHasIC_Megamorphic)
-IC_BUILTIN(KeyedHasIC_PolymorphicName)
+void Builtins::Generate_LoadGlobalICTrampoline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLoadGlobalICTrampoline(TypeofMode::kNotInside);
+}
 
-IC_BUILTIN_PARAM(LoadGlobalIC, LoadGlobalIC, NOT_INSIDE_TYPEOF)
-IC_BUILTIN_PARAM(LoadGlobalICInsideTypeof, LoadGlobalIC, INSIDE_TYPEOF)
-IC_BUILTIN_PARAM(LoadGlobalICTrampoline, LoadGlobalICTrampoline,
-                 NOT_INSIDE_TYPEOF)
-IC_BUILTIN_PARAM(LoadGlobalICInsideTypeofTrampoline, LoadGlobalICTrampoline,
-                 INSIDE_TYPEOF)
-IC_BUILTIN_PARAM(LoadGlobalICBaseline, LoadGlobalICBaseline, NOT_INSIDE_TYPEOF)
-IC_BUILTIN_PARAM(LoadGlobalICInsideTypeofBaseline, LoadGlobalICBaseline,
-                 INSIDE_TYPEOF)
-IC_BUILTIN_PARAM(LookupGlobalICBaseline, LookupGlobalICBaseline,
-                 NOT_INSIDE_TYPEOF)
-IC_BUILTIN_PARAM(LookupGlobalICInsideTypeofBaseline, LookupGlobalICBaseline,
-                 INSIDE_TYPEOF)
-IC_BUILTIN_PARAM(LookupContextBaseline, LookupContextBaseline,
-                 NOT_INSIDE_TYPEOF)
-IC_BUILTIN_PARAM(LookupContextInsideTypeofBaseline, LookupContextBaseline,
-                 INSIDE_TYPEOF)
+void Builtins::Generate_LoadGlobalICInsideTypeofTrampoline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLoadGlobalICTrampoline(TypeofMode::kInside);
+}
+
+void Builtins::Generate_LoadGlobalICBaseline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLoadGlobalICBaseline(TypeofMode::kNotInside);
+}
+
+void Builtins::Generate_LoadGlobalICInsideTypeofBaseline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLoadGlobalICBaseline(TypeofMode::kInside);
+}
+
+void Builtins::Generate_LookupGlobalICBaseline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLookupGlobalICBaseline(TypeofMode::kNotInside);
+}
+
+void Builtins::Generate_LookupGlobalICInsideTypeofBaseline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLookupGlobalICBaseline(TypeofMode::kInside);
+}
+
+void Builtins::Generate_LookupContextBaseline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLookupContextBaseline(TypeofMode::kNotInside);
+}
+
+void Builtins::Generate_LookupContextInsideTypeofBaseline(
+    compiler::CodeAssemblerState* state) {
+  AccessorAssembler assembler(state);
+  assembler.GenerateLookupContextBaseline(TypeofMode::kInside);
+}
 
 TF_BUILTIN(DynamicCheckMaps, CodeStubAssembler) {
   auto map = Parameter<Map>(Descriptor::kMap);
diff --git a/chromium/v8/src/builtins/builtins-internal-gen.cc b/chromium/v8/src/builtins/builtins-internal-gen.cc
index 0c4131dba96..274709b46a0 100644
--- a/chromium/v8/src/builtins/builtins-internal-gen.cc
+++ b/chromium/v8/src/builtins/builtins-internal-gen.cc
@@ -7,6 +7,7 @@
 #include "src/builtins/builtins-utils-gen.h"
 #include "src/builtins/builtins.h"
 #include "src/codegen/code-stub-assembler.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/macro-assembler.h"
 #include "src/execution/frame-constants.h"
 #include "src/heap/memory-chunk.h"
@@ -172,11 +173,11 @@ class RecordWriteCodeStubAssembler : public CodeStubAssembler {
   }
 
   TNode<BoolT> ShouldSkipFPRegs(TNode<Smi> mode) {
-    return TaggedEqual(mode, SmiConstant(kDontSaveFPRegs));
+    return TaggedEqual(mode, SmiConstant(SaveFPRegsMode::kIgnore));
   }
 
   TNode<BoolT> ShouldEmitRememberSet(TNode<Smi> remembered_set) {
-    return TaggedEqual(remembered_set, SmiConstant(EMIT_REMEMBERED_SET));
+    return TaggedEqual(remembered_set, SmiConstant(RememberedSetAction::kEmit));
   }
 
   template <typename Ret, typename Arg0, typename Arg1>
@@ -188,7 +189,7 @@ class RecordWriteCodeStubAssembler : public CodeStubAssembler {
     BIND(&dont_save_fp);
     {
       CallCFunctionWithCallerSavedRegisters(
-          function, MachineTypeOf<Ret>::value, kDontSaveFPRegs,
+          function, MachineTypeOf<Ret>::value, SaveFPRegsMode::kIgnore,
           std::make_pair(MachineTypeOf<Arg0>::value, arg0),
           std::make_pair(MachineTypeOf<Arg1>::value, arg1));
       Goto(next);
@@ -197,7 +198,7 @@ class RecordWriteCodeStubAssembler : public CodeStubAssembler {
     BIND(&save_fp);
     {
       CallCFunctionWithCallerSavedRegisters(
-          function, MachineTypeOf<Ret>::value, kSaveFPRegs,
+          function, MachineTypeOf<Ret>::value, SaveFPRegsMode::kSave,
           std::make_pair(MachineTypeOf<Arg0>::value, arg0),
           std::make_pair(MachineTypeOf<Arg1>::value, arg1));
       Goto(next);
@@ -213,7 +214,7 @@ class RecordWriteCodeStubAssembler : public CodeStubAssembler {
     BIND(&dont_save_fp);
     {
       CallCFunctionWithCallerSavedRegisters(
-          function, MachineTypeOf<Ret>::value, kDontSaveFPRegs,
+          function, MachineTypeOf<Ret>::value, SaveFPRegsMode::kIgnore,
           std::make_pair(MachineTypeOf<Arg0>::value, arg0),
           std::make_pair(MachineTypeOf<Arg1>::value, arg1),
           std::make_pair(MachineTypeOf<Arg2>::value, arg2));
@@ -223,7 +224,7 @@ class RecordWriteCodeStubAssembler : public CodeStubAssembler {
     BIND(&save_fp);
     {
       CallCFunctionWithCallerSavedRegisters(
-          function, MachineTypeOf<Ret>::value, kSaveFPRegs,
+          function, MachineTypeOf<Ret>::value, SaveFPRegsMode::kSave,
           std::make_pair(MachineTypeOf<Arg0>::value, arg0),
           std::make_pair(MachineTypeOf<Arg1>::value, arg1),
           std::make_pair(MachineTypeOf<Arg2>::value, arg2));
@@ -821,8 +822,9 @@ TF_BUILTIN(AdaptorWithBuiltinExitFrame, CodeStubAssembler) {
       Int32Constant(BuiltinExitFrameConstants::kNumExtraArgsWithReceiver));
 
   const bool builtin_exit_frame = true;
-  TNode<Code> code = HeapConstant(CodeFactory::CEntry(
-      isolate(), 1, kDontSaveFPRegs, kArgvOnStack, builtin_exit_frame));
+  TNode<Code> code =
+      HeapConstant(CodeFactory::CEntry(isolate(), 1, SaveFPRegsMode::kIgnore,
+                                       ArgvMode::kStack, builtin_exit_frame));
 
   // Unconditionally push argc, target and new target as extra stack arguments.
   // They will be used by stack frame iterators when constructing stack trace.
@@ -891,54 +893,54 @@ TF_BUILTIN(AbortCSAAssert, CodeStubAssembler) {
 
 void Builtins::Generate_CEntry_Return1_DontSaveFPRegs_ArgvOnStack_NoBuiltinExit(
     MacroAssembler* masm) {
-  Generate_CEntry(masm, 1, kDontSaveFPRegs, kArgvOnStack, false);
+  Generate_CEntry(masm, 1, SaveFPRegsMode::kIgnore, ArgvMode::kStack, false);
 }
 
 void Builtins::Generate_CEntry_Return1_DontSaveFPRegs_ArgvOnStack_BuiltinExit(
     MacroAssembler* masm) {
-  Generate_CEntry(masm, 1, kDontSaveFPRegs, kArgvOnStack, true);
+  Generate_CEntry(masm, 1, SaveFPRegsMode::kIgnore, ArgvMode::kStack, true);
 }
 
 void Builtins::
     Generate_CEntry_Return1_DontSaveFPRegs_ArgvInRegister_NoBuiltinExit(
         MacroAssembler* masm) {
-  Generate_CEntry(masm, 1, kDontSaveFPRegs, kArgvInRegister, false);
+  Generate_CEntry(masm, 1, SaveFPRegsMode::kIgnore, ArgvMode::kRegister, false);
 }
 
 void Builtins::Generate_CEntry_Return1_SaveFPRegs_ArgvOnStack_NoBuiltinExit(
     MacroAssembler* masm) {
-  Generate_CEntry(masm, 1, kSaveFPRegs, kArgvOnStack, false);
+  Generate_CEntry(masm, 1, SaveFPRegsMode::kSave, ArgvMode::kStack, false);
 }
 
 void Builtins::Generate_CEntry_Return1_SaveFPRegs_ArgvOnStack_BuiltinExit(
     MacroAssembler* masm) {
-  Generate_CEntry(masm, 1, kSaveFPRegs, kArgvOnStack, true);
+  Generate_CEntry(masm, 1, SaveFPRegsMode::kSave, ArgvMode::kStack, true);
 }
 
 void Builtins::Generate_CEntry_Return2_DontSaveFPRegs_ArgvOnStack_NoBuiltinExit(
     MacroAssembler* masm) {
-  Generate_CEntry(masm, 2, kDontSaveFPRegs, kArgvOnStack, false);
+  Generate_CEntry(masm, 2, SaveFPRegsMode::kIgnore, ArgvMode::kStack, false);
 }
 
 void Builtins::Generate_CEntry_Return2_DontSaveFPRegs_ArgvOnStack_BuiltinExit(
     MacroAssembler* masm) {
-  Generate_CEntry(masm, 2, kDontSaveFPRegs, kArgvOnStack, true);
+  Generate_CEntry(masm, 2, SaveFPRegsMode::kIgnore, ArgvMode::kStack, true);
 }
 
 void Builtins::
     Generate_CEntry_Return2_DontSaveFPRegs_ArgvInRegister_NoBuiltinExit(
         MacroAssembler* masm) {
-  Generate_CEntry(masm, 2, kDontSaveFPRegs, kArgvInRegister, false);
+  Generate_CEntry(masm, 2, SaveFPRegsMode::kIgnore, ArgvMode::kRegister, false);
 }
 
 void Builtins::Generate_CEntry_Return2_SaveFPRegs_ArgvOnStack_NoBuiltinExit(
     MacroAssembler* masm) {
-  Generate_CEntry(masm, 2, kSaveFPRegs, kArgvOnStack, false);
+  Generate_CEntry(masm, 2, SaveFPRegsMode::kSave, ArgvMode::kStack, false);
 }
 
 void Builtins::Generate_CEntry_Return2_SaveFPRegs_ArgvOnStack_BuiltinExit(
     MacroAssembler* masm) {
-  Generate_CEntry(masm, 2, kSaveFPRegs, kArgvOnStack, true);
+  Generate_CEntry(masm, 2, SaveFPRegsMode::kSave, ArgvMode::kStack, true);
 }
 
 #if !defined(V8_TARGET_ARCH_ARM) && !defined(V8_TARGET_ARCH_MIPS)
@@ -956,7 +958,7 @@ void Builtins::Generate_MemMove(MacroAssembler* masm) {
 // TODO(v8:11421): Remove #if once baseline compiler is ported to other
 // architectures.
 #if V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || \
-    V8_TARGET_ARCH_ARM
+    V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_RISCV64
 void Builtins::Generate_BaselineLeaveFrame(MacroAssembler* masm) {
   EmitReturnBaseline(masm);
 }
diff --git a/chromium/v8/src/builtins/builtins-intl.cc b/chromium/v8/src/builtins/builtins-intl.cc
index fe32a484a3e..6febc81c3a5 100644
--- a/chromium/v8/src/builtins/builtins-intl.cc
+++ b/chromium/v8/src/builtins/builtins-intl.cc
@@ -668,6 +668,49 @@ BUILTIN(LocalePrototypeMinimize) {
   RETURN_RESULT_OR_FAILURE(isolate, JSLocale::Minimize(isolate, locale));
 }
 
+BUILTIN(LocalePrototypeCalendars) {
+  HandleScope scope(isolate);
+  CHECK_RECEIVER(JSLocale, locale, "Intl.Locale.prototype.calendars");
+  RETURN_RESULT_OR_FAILURE(isolate, JSLocale::Calendars(isolate, locale));
+}
+
+BUILTIN(LocalePrototypeCollations) {
+  HandleScope scope(isolate);
+  CHECK_RECEIVER(JSLocale, locale, "Intl.Locale.prototype.collations");
+  RETURN_RESULT_OR_FAILURE(isolate, JSLocale::Collations(isolate, locale));
+}
+
+BUILTIN(LocalePrototypeHourCycles) {
+  HandleScope scope(isolate);
+  CHECK_RECEIVER(JSLocale, locale, "Intl.Locale.prototype.hourCycles");
+  RETURN_RESULT_OR_FAILURE(isolate, JSLocale::HourCycles(isolate, locale));
+}
+
+BUILTIN(LocalePrototypeNumberingSystems) {
+  HandleScope scope(isolate);
+  CHECK_RECEIVER(JSLocale, locale, "Intl.Locale.prototype.numberingSystems");
+  RETURN_RESULT_OR_FAILURE(isolate,
+                           JSLocale::NumberingSystems(isolate, locale));
+}
+
+BUILTIN(LocalePrototypeTextInfo) {
+  HandleScope scope(isolate);
+  CHECK_RECEIVER(JSLocale, locale, "Intl.Locale.prototype.textInfo");
+  RETURN_RESULT_OR_FAILURE(isolate, JSLocale::TextInfo(isolate, locale));
+}
+
+BUILTIN(LocalePrototypeTimeZones) {
+  HandleScope scope(isolate);
+  CHECK_RECEIVER(JSLocale, locale, "Intl.Locale.prototype.timeZones");
+  RETURN_RESULT_OR_FAILURE(isolate, JSLocale::TimeZones(isolate, locale));
+}
+
+BUILTIN(LocalePrototypeWeekInfo) {
+  HandleScope scope(isolate);
+  CHECK_RECEIVER(JSLocale, locale, "Intl.Locale.prototype.weekInfo");
+  RETURN_RESULT_OR_FAILURE(isolate, JSLocale::WeekInfo(isolate, locale));
+}
+
 BUILTIN(RelativeTimeFormatSupportedLocalesOf) {
   HandleScope scope(isolate);
   Handle<Object> locales = args.atOrUndefined(isolate, 1);
diff --git a/chromium/v8/src/builtins/builtins-lazy-gen.cc b/chromium/v8/src/builtins/builtins-lazy-gen.cc
index 8af0bef95d2..4749ee094bc 100644
--- a/chromium/v8/src/builtins/builtins-lazy-gen.cc
+++ b/chromium/v8/src/builtins/builtins-lazy-gen.cc
@@ -154,20 +154,7 @@ void LazyBuiltinsAssembler::CompileLazy(TNode<JSFunction> function) {
   GotoIf(InstanceTypeEqual(sfi_data_type.value(), BASELINE_DATA_TYPE),
          &baseline);
 
-  // Finally, check for presence of an NCI cached Code object - if an entry
-  // possibly exists, call into runtime to query the cache.
-  TNode<Uint8T> flags2 =
-      LoadObjectField<Uint8T>(shared, SharedFunctionInfo::kFlags2Offset);
-  TNode<BoolT> may_have_cached_code =
-      IsSetWord32<SharedFunctionInfo::MayHaveCachedCodeBit>(flags2);
-  code = Select<Code>(
-      may_have_cached_code,
-      [=]() {
-        return CAST(CallRuntime(Runtime::kTryInstallNCICode,
-                                Parameter<Context>(Descriptor::kContext),
-                                function));
-      },
-      [=]() { return sfi_code; });
+  code = sfi_code;
   Goto(&tailcall_code);
 
   BIND(&baseline);
diff --git a/chromium/v8/src/builtins/builtins-microtask-queue-gen.cc b/chromium/v8/src/builtins/builtins-microtask-queue-gen.cc
index 9f16186d13b..281e9234dc7 100644
--- a/chromium/v8/src/builtins/builtins-microtask-queue-gen.cc
+++ b/chromium/v8/src/builtins/builtins-microtask-queue-gen.cc
@@ -46,8 +46,11 @@ class MicrotaskQueueBuiltinsAssembler : public CodeStubAssembler {
   void EnterMicrotaskContext(TNode<Context> native_context);
   void RewindEnteredContext(TNode<IntPtrT> saved_entered_context_count);
 
+  void RunAllPromiseHooks(PromiseHookType type, TNode<Context> context,
+                          TNode<HeapObject> promise_or_capability);
   void RunPromiseHook(Runtime::FunctionId id, TNode<Context> context,
-                      TNode<HeapObject> promise_or_capability);
+                      TNode<HeapObject> promise_or_capability,
+                      TNode<Uint32T> promiseHookFlags);
 };
 
 TNode<RawPtrT> MicrotaskQueueBuiltinsAssembler::GetMicrotaskQueue(
@@ -199,7 +202,7 @@ void MicrotaskQueueBuiltinsAssembler::RunSingleMicrotask(
     const TNode<Object> thenable = LoadObjectField(
         microtask, PromiseResolveThenableJobTask::kThenableOffset);
 
-    RunPromiseHook(Runtime::kPromiseHookBefore, microtask_context,
+    RunAllPromiseHooks(PromiseHookType::kBefore, microtask_context,
                    CAST(promise_to_resolve));
 
     {
@@ -208,7 +211,7 @@ void MicrotaskQueueBuiltinsAssembler::RunSingleMicrotask(
                   promise_to_resolve, thenable, then);
     }
 
-    RunPromiseHook(Runtime::kPromiseHookAfter, microtask_context,
+    RunAllPromiseHooks(PromiseHookType::kAfter, microtask_context,
                    CAST(promise_to_resolve));
 
     RewindEnteredContext(saved_entered_context_count);
@@ -243,8 +246,8 @@ void MicrotaskQueueBuiltinsAssembler::RunSingleMicrotask(
     BIND(&preserved_data_done);
 
     // Run the promise before/debug hook if enabled.
-    RunPromiseHook(Runtime::kPromiseHookBefore, microtask_context,
-                   promise_or_capability);
+    RunAllPromiseHooks(PromiseHookType::kBefore, microtask_context,
+                       promise_or_capability);
 
     {
       ScopedExceptionHandler handler(this, &if_exception, &var_exception);
@@ -253,8 +256,8 @@ void MicrotaskQueueBuiltinsAssembler::RunSingleMicrotask(
     }
 
     // Run the promise after/debug hook if enabled.
-    RunPromiseHook(Runtime::kPromiseHookAfter, microtask_context,
-                   promise_or_capability);
+    RunAllPromiseHooks(PromiseHookType::kAfter, microtask_context,
+                       promise_or_capability);
 
     Label preserved_data_reset_done(this);
     GotoIf(IsUndefined(preserved_embedder_data), &preserved_data_reset_done);
@@ -296,8 +299,8 @@ void MicrotaskQueueBuiltinsAssembler::RunSingleMicrotask(
     BIND(&preserved_data_done);
 
     // Run the promise before/debug hook if enabled.
-    RunPromiseHook(Runtime::kPromiseHookBefore, microtask_context,
-                   promise_or_capability);
+    RunAllPromiseHooks(PromiseHookType::kBefore, microtask_context,
+                       promise_or_capability);
 
     {
       ScopedExceptionHandler handler(this, &if_exception, &var_exception);
@@ -306,8 +309,8 @@ void MicrotaskQueueBuiltinsAssembler::RunSingleMicrotask(
     }
 
     // Run the promise after/debug hook if enabled.
-    RunPromiseHook(Runtime::kPromiseHookAfter, microtask_context,
-                   promise_or_capability);
+    RunAllPromiseHooks(PromiseHookType::kAfter, microtask_context,
+                       promise_or_capability);
 
     Label preserved_data_reset_done(this);
     GotoIf(IsUndefined(preserved_embedder_data), &preserved_data_reset_done);
@@ -465,12 +468,42 @@ void MicrotaskQueueBuiltinsAssembler::RewindEnteredContext(
       saved_entered_context_count);
 }
 
+void MicrotaskQueueBuiltinsAssembler::RunAllPromiseHooks(
+    PromiseHookType type, TNode<Context> context,
+    TNode<HeapObject> promise_or_capability) {
+  Label hook(this, Label::kDeferred), done_hook(this);
+  TNode<Uint32T> promiseHookFlags = PromiseHookFlags();
+  Branch(NeedsAnyPromiseHooks(promiseHookFlags), &hook, &done_hook);
+  BIND(&hook);
+  {
+    switch (type) {
+      case PromiseHookType::kBefore:
+        RunContextPromiseHookBefore(context, promise_or_capability,
+                                    promiseHookFlags);
+        RunPromiseHook(Runtime::kPromiseHookBefore, context,
+                       promise_or_capability, promiseHookFlags);
+        break;
+      case PromiseHookType::kAfter:
+        RunContextPromiseHookAfter(context, promise_or_capability,
+                                   promiseHookFlags);
+        RunPromiseHook(Runtime::kPromiseHookAfter, context,
+                       promise_or_capability, promiseHookFlags);
+        break;
+      default:
+        UNREACHABLE();
+    }
+    Goto(&done_hook);
+  }
+  BIND(&done_hook);
+}
+
 void MicrotaskQueueBuiltinsAssembler::RunPromiseHook(
     Runtime::FunctionId id, TNode<Context> context,
-    TNode<HeapObject> promise_or_capability) {
+    TNode<HeapObject> promise_or_capability,
+    TNode<Uint32T> promiseHookFlags) {
   Label hook(this, Label::kDeferred), done_hook(this);
-  Branch(IsPromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate(), &hook,
-         &done_hook);
+  Branch(IsIsolatePromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate(
+      promiseHookFlags), &hook, &done_hook);
   BIND(&hook);
   {
     // Get to the underlying JSPromise instance.
diff --git a/chromium/v8/src/builtins/builtins-regexp-gen.cc b/chromium/v8/src/builtins/builtins-regexp-gen.cc
index 23648efb98b..e59d2a00ac3 100644
--- a/chromium/v8/src/builtins/builtins-regexp-gen.cc
+++ b/chromium/v8/src/builtins/builtins-regexp-gen.cc
@@ -1014,6 +1014,12 @@ TF_BUILTIN(RegExpExecInternal, RegExpBuiltinsAssembler) {
 TNode<String> RegExpBuiltinsAssembler::FlagsGetter(TNode<Context> context,
                                                    TNode<Object> regexp,
                                                    bool is_fastpath) {
+  TVARIABLE(String, result);
+  Label runtime(this, Label::kDeferred), done(this, &result);
+  if (is_fastpath) {
+    GotoIfForceSlowPath(&runtime);
+  }
+
   Isolate* isolate = this->isolate();
 
   const TNode<IntPtrT> int_one = IntPtrConstant(1);
@@ -1110,7 +1116,7 @@ TNode<String> RegExpBuiltinsAssembler::FlagsGetter(TNode<Context> context,
   // corresponding char for each set flag.
 
   {
-    const TNode<String> result = AllocateSeqOneByteString(var_length.value());
+    const TNode<String> string = AllocateSeqOneByteString(var_length.value());
 
     TVARIABLE(IntPtrT, var_offset,
               IntPtrConstant(SeqOneByteString::kHeaderSize - kHeapObjectTag));
@@ -1120,7 +1126,7 @@ TNode<String> RegExpBuiltinsAssembler::FlagsGetter(TNode<Context> context,
     Label next(this);                                          \
     GotoIfNot(IsSetWord(var_flags.value(), FLAG), &next);      \
     const TNode<Int32T> value = Int32Constant(CHAR);           \
-    StoreNoWriteBarrier(MachineRepresentation::kWord8, result, \
+    StoreNoWriteBarrier(MachineRepresentation::kWord8, string, \
                         var_offset.value(), value);            \
     var_offset = IntPtrAdd(var_offset.value(), int_one);       \
     Goto(&next);                                               \
@@ -1137,7 +1143,26 @@ TNode<String> RegExpBuiltinsAssembler::FlagsGetter(TNode<Context> context,
     CASE_FOR_FLAG(JSRegExp::kSticky, 'y');
 #undef CASE_FOR_FLAG
 
-    return result;
+    if (is_fastpath) {
+#ifdef V8_ENABLE_FORCE_SLOW_PATH
+      result = string;
+      Goto(&done);
+
+      BIND(&runtime);
+      {
+        result =
+            CAST(CallRuntime(Runtime::kRegExpStringFromFlags, context, regexp));
+        Goto(&done);
+      }
+
+      BIND(&done);
+      return result.value();
+#else
+      return string;
+#endif
+    } else {
+      return string;
+    }
   }
 }
 
diff --git a/chromium/v8/src/builtins/builtins-trace.cc b/chromium/v8/src/builtins/builtins-trace.cc
index cf85ce9948b..24baf59522b 100644
--- a/chromium/v8/src/builtins/builtins-trace.cc
+++ b/chromium/v8/src/builtins/builtins-trace.cc
@@ -9,6 +9,7 @@
 #include "src/json/json-stringifier.h"
 #include "src/logging/counters.h"
 #include "src/objects/objects-inl.h"
+#include "src/tracing/traced-value.h"
 
 #if defined(V8_USE_PERFETTO)
 #include "protos/perfetto/trace/track_event/debug_annotation.pbzero.h"
diff --git a/chromium/v8/src/builtins/builtins-typed-array-gen.cc b/chromium/v8/src/builtins/builtins-typed-array-gen.cc
index 65b1ab2f2b9..d333a61e395 100644
--- a/chromium/v8/src/builtins/builtins-typed-array-gen.cc
+++ b/chromium/v8/src/builtins/builtins-typed-array-gen.cc
@@ -123,13 +123,26 @@ TF_BUILTIN(TypedArrayPrototypeByteLength, TypedArrayBuiltinsAssembler) {
   // Check if the {receiver} is actually a JSTypedArray.
   ThrowIfNotInstanceType(context, receiver, JS_TYPED_ARRAY_TYPE, kMethodName);
 
-  // Default to zero if the {receiver}s buffer was detached.
+  TNode<JSTypedArray> receiver_array = CAST(receiver);
   TNode<JSArrayBuffer> receiver_buffer =
-      LoadJSArrayBufferViewBuffer(CAST(receiver));
-  TNode<UintPtrT> byte_length = Select<UintPtrT>(
-      IsDetachedBuffer(receiver_buffer), [=] { return UintPtrConstant(0); },
-      [=] { return LoadJSArrayBufferViewByteLength(CAST(receiver)); });
-  Return(ChangeUintPtrToTagged(byte_length));
+      LoadJSArrayBufferViewBuffer(receiver_array);
+
+  Label variable_length(this), normal(this);
+  Branch(IsVariableLengthTypedArray(receiver_array), &variable_length, &normal);
+  BIND(&variable_length);
+  {
+    Return(ChangeUintPtrToTagged(LoadVariableLengthJSTypedArrayByteLength(
+        context, receiver_array, receiver_buffer)));
+  }
+
+  BIND(&normal);
+  {
+    // Default to zero if the {receiver}s buffer was detached.
+    TNode<UintPtrT> byte_length = Select<UintPtrT>(
+        IsDetachedBuffer(receiver_buffer), [=] { return UintPtrConstant(0); },
+        [=] { return LoadJSArrayBufferViewByteLength(receiver_array); });
+    Return(ChangeUintPtrToTagged(byte_length));
+  }
 }
 
 // ES6 #sec-get-%typedarray%.prototype.byteoffset
@@ -159,13 +172,29 @@ TF_BUILTIN(TypedArrayPrototypeLength, TypedArrayBuiltinsAssembler) {
   // Check if the {receiver} is actually a JSTypedArray.
   ThrowIfNotInstanceType(context, receiver, JS_TYPED_ARRAY_TYPE, kMethodName);
 
-  // Default to zero if the {receiver}s buffer was detached.
+  TNode<JSTypedArray> receiver_array = CAST(receiver);
   TNode<JSArrayBuffer> receiver_buffer =
-      LoadJSArrayBufferViewBuffer(CAST(receiver));
-  TNode<UintPtrT> length = Select<UintPtrT>(
-      IsDetachedBuffer(receiver_buffer), [=] { return UintPtrConstant(0); },
-      [=] { return LoadJSTypedArrayLength(CAST(receiver)); });
-  Return(ChangeUintPtrToTagged(length));
+      LoadJSArrayBufferViewBuffer(receiver_array);
+
+  Label variable_length(this), normal(this);
+  Branch(IsVariableLengthTypedArray(receiver_array), &variable_length, &normal);
+  BIND(&variable_length);
+  {
+    Label miss(this);
+    Return(ChangeUintPtrToTagged(LoadVariableLengthJSTypedArrayLength(
+        receiver_array, receiver_buffer, &miss)));
+    BIND(&miss);
+    Return(ChangeUintPtrToTagged(UintPtrConstant(0)));
+  }
+
+  BIND(&normal);
+  {
+    // Default to zero if the {receiver}s buffer was detached.
+    TNode<UintPtrT> length = Select<UintPtrT>(
+        IsDetachedBuffer(receiver_buffer), [=] { return UintPtrConstant(0); },
+        [=] { return LoadJSTypedArrayLength(receiver_array); });
+    Return(ChangeUintPtrToTagged(length));
+  }
 }
 
 TNode<BoolT> TypedArrayBuiltinsAssembler::IsUint8ElementsKind(
@@ -322,17 +351,18 @@ void TypedArrayBuiltinsAssembler::DispatchTypedArrayByElementsKind(
 
   int32_t elements_kinds[] = {
 #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) TYPE##_ELEMENTS,
-      TYPED_ARRAYS(TYPED_ARRAY_CASE)
+      TYPED_ARRAYS(TYPED_ARRAY_CASE) RAB_GSAB_TYPED_ARRAYS(TYPED_ARRAY_CASE)
 #undef TYPED_ARRAY_CASE
   };
 
 #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) Label if_##type##array(this);
   TYPED_ARRAYS(TYPED_ARRAY_CASE)
+  RAB_GSAB_TYPED_ARRAYS(TYPED_ARRAY_CASE)
 #undef TYPED_ARRAY_CASE
 
   Label* elements_kind_labels[] = {
 #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) &if_##type##array,
-      TYPED_ARRAYS(TYPED_ARRAY_CASE)
+      TYPED_ARRAYS(TYPED_ARRAY_CASE) RAB_GSAB_TYPED_ARRAYS(TYPED_ARRAY_CASE)
 #undef TYPED_ARRAY_CASE
   };
   STATIC_ASSERT(arraysize(elements_kinds) == arraysize(elements_kind_labels));
@@ -350,6 +380,15 @@ void TypedArrayBuiltinsAssembler::DispatchTypedArrayByElementsKind(
   TYPED_ARRAYS(TYPED_ARRAY_CASE)
 #undef TYPED_ARRAY_CASE
 
+#define TYPED_ARRAY_CASE(Type, type, TYPE, ctype)     \
+  BIND(&if_##type##array);                            \
+  {                                                   \
+    case_function(TYPE##_ELEMENTS, sizeof(ctype), 0); \
+    Goto(&next);                                      \
+  }
+  RAB_GSAB_TYPED_ARRAYS(TYPED_ARRAY_CASE)
+#undef TYPED_ARRAY_CASE
+
   BIND(&if_unknown_type);
   Unreachable();
 
@@ -374,7 +413,7 @@ void TypedArrayBuiltinsAssembler::SetJSTypedArrayOnHeapDataPtr(
         IntPtrSub(full_base, Signed(ChangeUint32ToWord(compressed_base)));
     // Add JSTypedArray::ExternalPointerCompensationForOnHeapArray() to offset.
     DCHECK_EQ(
-        isolate()->isolate_root(),
+        isolate()->cage_base(),
         JSTypedArray::ExternalPointerCompensationForOnHeapArray(isolate()));
     // See JSTypedArray::SetOnHeapDataPtr() for details.
     offset = Unsigned(IntPtrAdd(offset, ptr_compr_cage_base));
diff --git a/chromium/v8/src/builtins/builtins-typed-array.cc b/chromium/v8/src/builtins/builtins-typed-array.cc
index fdadc7a554c..bb936e6e463 100644
--- a/chromium/v8/src/builtins/builtins-typed-array.cc
+++ b/chromium/v8/src/builtins/builtins-typed-array.cc
@@ -154,7 +154,8 @@ BUILTIN(TypedArrayPrototypeFill) {
   DCHECK_LE(end, len);
   DCHECK_LE(count, len);
 
-  return ElementsAccessor::ForKind(kind)->Fill(array, obj_value, start, end);
+  RETURN_RESULT_OR_FAILURE(isolate, ElementsAccessor::ForKind(kind)->Fill(
+                                        array, obj_value, start, end));
 }
 
 BUILTIN(TypedArrayPrototypeIncludes) {
diff --git a/chromium/v8/src/builtins/builtins-utils.h b/chromium/v8/src/builtins/builtins-utils.h
index e5f420a20de..b9146ab6253 100644
--- a/chromium/v8/src/builtins/builtins-utils.h
+++ b/chromium/v8/src/builtins/builtins-utils.h
@@ -85,8 +85,7 @@ class BuiltinArguments : public JavaScriptArguments {
   V8_NOINLINE static Address Builtin_Impl_Stats_##name(                     \
       int args_length, Address* args_object, Isolate* isolate) {            \
     BuiltinArguments args(args_length, args_object);                        \
-    RuntimeCallTimerScope timer(isolate,                                    \
-                                RuntimeCallCounterId::kBuiltin_##name);     \
+    RCS_SCOPE(isolate, RuntimeCallCounterId::kBuiltin_##name);              \
     TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.runtime"),                   \
                  "V8.Builtin_" #name);                                      \
     return CONVERT_OBJECT(Builtin_Impl_##name(args, isolate));              \
diff --git a/chromium/v8/src/builtins/builtins-wasm-gen.cc b/chromium/v8/src/builtins/builtins-wasm-gen.cc
index 0704d8681ba..eb9311d0c62 100644
--- a/chromium/v8/src/builtins/builtins-wasm-gen.cc
+++ b/chromium/v8/src/builtins/builtins-wasm-gen.cc
@@ -9,7 +9,6 @@
 #include "src/codegen/interface-descriptors.h"
 #include "src/objects/objects-inl.h"
 #include "src/wasm/wasm-objects.h"
-#include "src/wasm/wasm-opcodes.h"
 
 namespace v8 {
 namespace internal {
diff --git a/chromium/v8/src/builtins/cast.tq b/chromium/v8/src/builtins/cast.tq
index b490055a19e..d7d2eb6aa6d 100644
--- a/chromium/v8/src/builtins/cast.tq
+++ b/chromium/v8/src/builtins/cast.tq
@@ -329,6 +329,24 @@ Cast<Number|TheHole>(o: Object): Number|TheHole labels CastError {
   }
 }
 
+Cast<Context|Zero|Undefined>(o: Object): Context|Zero|Undefined
+    labels CastError {
+  typeswitch (o) {
+    case (o: Context): {
+      return o;
+    }
+    case (o: Zero): {
+      return o;
+    }
+    case (o: Undefined): {
+      return o;
+    }
+    case (Object): {
+      goto CastError;
+    }
+  }
+}
+
 macro Cast<A : type extends HeapObject>(o: HeapObject): A
     labels CastError;
 
@@ -386,6 +404,12 @@ Cast<Undefined|Callable>(o: HeapObject): Undefined|Callable
   return HeapObjectToCallable(o) otherwise CastError;
 }
 
+Cast<Undefined|JSFunction>(o: HeapObject): Undefined|JSFunction
+    labels CastError {
+  if (o == Undefined) return Undefined;
+  return Cast<JSFunction>(o) otherwise CastError;
+}
+
 macro Cast<T : type extends Symbol>(o: Symbol): T labels CastError;
 Cast<PublicSymbol>(s: Symbol): PublicSymbol labels CastError {
   if (s.flags.is_private) goto CastError;
diff --git a/chromium/v8/src/builtins/constructor.tq b/chromium/v8/src/builtins/constructor.tq
index add6db03052..d929c7f485f 100644
--- a/chromium/v8/src/builtins/constructor.tq
+++ b/chromium/v8/src/builtins/constructor.tq
@@ -15,6 +15,8 @@ extern runtime CreateObjectLiteral(
 
 namespace constructor {
 
+extern builtin FastNewClosure(
+    Context, SharedFunctionInfo, FeedbackCell): JSFunction;
 extern builtin FastNewObject(Context, JSFunction, JSReceiver): JSObject;
 
 extern enum AllocationSiteMode {
@@ -42,6 +44,15 @@ extern macro ConstructorBuiltinsAssembler::CreateShallowObjectLiteral(
 extern macro ConstructorBuiltinsAssembler::CreateEmptyObjectLiteral(Context):
     JSObject;
 
+extern macro LoadContextFromBaseline(): Context;
+
+builtin FastNewClosureBaseline(
+    sharedFunctionInfo: SharedFunctionInfo,
+    feedbackCell: FeedbackCell): JSFunction {
+  const context = LoadContextFromBaseline();
+  tail FastNewClosure(context, sharedFunctionInfo, feedbackCell);
+}
+
 builtin FastNewFunctionContextEval(implicit context: Context)(
     scopeInfo: ScopeInfo, slots: uint32): Context {
   return FastNewFunctionContext(scopeInfo, slots, context, kEvalScope);
diff --git a/chromium/v8/src/builtins/conversion.tq b/chromium/v8/src/builtins/conversion.tq
index 5a2dccd068c..636f49a024d 100644
--- a/chromium/v8/src/builtins/conversion.tq
+++ b/chromium/v8/src/builtins/conversion.tq
@@ -45,11 +45,30 @@ builtin NumberToString(implicit context: Context)(input: Number): String {
 }
 
 // ES6 section 7.1.2 ToBoolean ( argument )
-builtin ToBoolean(implicit context: Context)(input: JSAny): Boolean {
+builtin ToBoolean(input: JSAny): Boolean {
   BranchIfToBooleanIsTrue(input) otherwise return TrueConstant(),
       return FalseConstant();
 }
 
+struct ToBooleanForBaselineJumpResult {
+  value: JSAny;
+  is_to_boolean: Smi;
+}
+// ToBoolean for baseline code jumps, which
+//   a) returns the original value as the first return value, to avoid needing
+//      to save it in the caller, and
+//   b) returns the true/false value as a Smi, to make the baseline-side
+//      comparison cheaper.
+builtin ToBooleanForBaselineJump(input: JSAny): ToBooleanForBaselineJumpResult {
+  try {
+    BranchIfToBooleanIsTrue(input) otherwise IsTrue, IsFalse;
+  } label IsTrue {
+    return ToBooleanForBaselineJumpResult{value: input, is_to_boolean: 1};
+  } label IsFalse {
+    return ToBooleanForBaselineJumpResult{value: input, is_to_boolean: 0};
+  }
+}
+
 transitioning builtin ToLength(implicit context: Context)(input: JSAny):
     Number {
   // We might need to loop once for ToNumber conversion.
diff --git a/chromium/v8/src/builtins/ia32/builtins-ia32.cc b/chromium/v8/src/builtins/ia32/builtins-ia32.cc
index 44b71bed915..4993de4816f 100644
--- a/chromium/v8/src/builtins/ia32/builtins-ia32.cc
+++ b/chromium/v8/src/builtins/ia32/builtins-ia32.cc
@@ -8,6 +8,7 @@
 #include "src/base/bits-iterator.h"
 #include "src/base/iterator.h"
 #include "src/codegen/code-factory.h"
+#include "src/codegen/interface-descriptors-inl.h"
 // For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
 #include "src/codegen/macro-assembler-inl.h"
 #include "src/codegen/register-configuration.h"
@@ -116,7 +117,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     // edx: new target
     // Reload context from the frame.
     __ mov(esi, Operand(ebp, ConstructFrameConstants::kContextOffset));
-    __ InvokeFunction(edi, edx, eax, CALL_FUNCTION);
+    __ InvokeFunction(edi, edx, eax, InvokeType::kCall);
 
     // Restore context from the frame.
     __ mov(esi, Operand(ebp, ConstructFrameConstants::kContextOffset));
@@ -245,7 +246,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
 
   // Restore and and call the constructor function.
   __ mov(edi, Operand(ebp, ConstructFrameConstants::kConstructorOffset));
-  __ InvokeFunction(edi, edx, eax, CALL_FUNCTION);
+  __ InvokeFunction(edi, edx, eax, InvokeType::kCall);
 
   // ----------- S t a t e -------------
   //  --                eax: constructor result
@@ -597,7 +598,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Store input value into generator object.
   __ mov(FieldOperand(edx, JSGeneratorObject::kInputOrDebugPosOffset), eax);
   __ RecordWriteField(edx, JSGeneratorObject::kInputOrDebugPosOffset, eax, ecx,
-                      kDontSaveFPRegs);
+                      SaveFPRegsMode::kIgnore);
 
   // Load suspended function and context.
   __ mov(edi, FieldOperand(edx, JSGeneratorObject::kFunctionOffset));
@@ -645,15 +646,12 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
            FieldOperand(edx, JSGeneratorObject::kParametersAndRegistersOffset));
     {
       Label done_loop, loop;
-      __ mov(edi, ecx);
-
       __ bind(&loop);
-      __ dec(edi);
+      __ dec(ecx);
       __ j(less, &done_loop);
       __ Push(
-          FieldOperand(ebx, edi, times_tagged_size, FixedArray::kHeaderSize));
+          FieldOperand(ebx, ecx, times_tagged_size, FixedArray::kHeaderSize));
       __ jmp(&loop);
-
       __ bind(&done_loop);
     }
 
@@ -740,7 +738,8 @@ static void ReplaceClosureCodeWithOptimizedCode(MacroAssembler* masm,
   __ mov(FieldOperand(closure, JSFunction::kCodeOffset), optimized_code);
   __ mov(scratch1, optimized_code);  // Write barrier clobbers scratch1 below.
   __ RecordWriteField(closure, JSFunction::kCodeOffset, scratch1, scratch2,
-                      kDontSaveFPRegs, OMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
+                      SaveFPRegsMode::kIgnore, RememberedSetAction::kOmit,
+                      SmiCheck::kOmit);
 }
 
 static void LeaveInterpreterFrame(MacroAssembler* masm, Register scratch1,
@@ -1458,7 +1457,7 @@ void Builtins::Generate_InterpreterPushArgsThenConstructImpl(
   // and edi are used as scratch registers.
   Generate_InterpreterPushZeroAndArgsAndReturnAddress(
       masm, eax, ecx, edx, edi,
-      InterpreterPushArgsThenConstructDescriptor::kStackArgumentsCount,
+      InterpreterPushArgsThenConstructDescriptor::GetStackParameterCount(),
       &stack_overflow);
 
   // Call the appropriate constructor. eax and ecx already contain intended
@@ -1591,7 +1590,7 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   __ jmp(kJavaScriptCallCodeStartRegister);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtNextBytecode(MacroAssembler* masm) {
   // Get bytecode array and bytecode offset from the stack frame.
   __ mov(kInterpreterBytecodeArrayRegister,
          Operand(ebp, InterpreterFrameConstants::kBytecodeArrayFromFp));
@@ -1636,7 +1635,7 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
   __ Abort(AbortReason::kInvalidBytecodeAdvance);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeDispatch(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtBytecode(MacroAssembler* masm) {
   Generate_InterpreterEnterBytecode(masm);
 }
 // static
@@ -1666,7 +1665,7 @@ void Builtins::Generate_BaselineOutOfLinePrologue(MacroAssembler* masm) {
   __ mov(feedback_vector,
          FieldOperand(closure, JSFunction::kFeedbackCellOffset));
   __ mov(feedback_vector, FieldOperand(feedback_vector, Cell::kValueOffset));
-  if (__ emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ CmpObjectType(feedback_vector, FEEDBACK_VECTOR_TYPE, scratch);
     __ Assert(equal, AbortReason::kExpectedFeedbackVector);
   }
@@ -1939,7 +1938,7 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   // arguments to the receiver.
   __ bind(&no_arguments);
   {
-    __ Set(eax, 0);
+    __ Move(eax, 0);
     __ Jump(masm->isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
   }
 }
@@ -2108,6 +2107,7 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
 }
 
 // static
+// TODO(v8:11615): Observe Code::kMaxArguments in CallOrConstructVarargs
 void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
                                                Handle<Code> code) {
   // ----------- S t a t e -------------
@@ -2133,7 +2133,7 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
   __ pop(kArgumentsList);
   __ PushReturnAddressFrom(edx);
 
-  if (masm->emit_debug_code()) {
+  if (FLAG_debug_code) {
     // Allow kArgumentsList to be a FixedArray, or a FixedDoubleArray if
     // kArgumentsLength == 0.
     Label ok, fail;
@@ -2294,7 +2294,7 @@ void Builtins::Generate_CallOrConstructForwardVarargs(MacroAssembler* masm,
       __ AllocateStackSpace(scratch);
       // Include return address and receiver.
       __ add(eax, Immediate(2));
-      __ Set(current, 0);
+      __ Move(current, 0);
       __ jmp(&check);
       // Loop.
       __ bind(&copy);
@@ -2443,7 +2443,7 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
 
   __ movzx_w(
       ecx, FieldOperand(edx, SharedFunctionInfo::kFormalParameterCountOffset));
-  __ InvokeFunctionCode(edi, no_reg, ecx, eax, JUMP_FUNCTION);
+  __ InvokeFunctionCode(edi, no_reg, ecx, eax, InvokeType::kJump);
   // The function is a "classConstructor", need to raise an exception.
   __ bind(&class_constructor);
   {
@@ -2788,6 +2788,8 @@ void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_BaselineOnStackReplacement(MacroAssembler* masm) {
+  __ mov(kContextRegister,
+         MemOperand(ebp, BaselineFrameConstants::kContextOffset));
   return OnStackReplacement(masm, false);
 }
 
@@ -2896,6 +2898,11 @@ void Builtins::Generate_GenericJSToWasmWrapper(MacroAssembler* masm) {
   // TODO(v8:10701): Implement for this platform.
   __ Trap();
 }
+
+void Builtins::Generate_WasmOnStackReplace(MacroAssembler* masm) {
+  // Only needed on x64.
+  __ Trap();
+}
 #endif  // V8_ENABLE_WEBASSEMBLY
 
 void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
@@ -2908,7 +2915,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // esi: current context (C callee-saved)
   // edi: JS function of the caller (C callee-saved)
   //
-  // If argv_mode == kArgvInRegister:
+  // If argv_mode == ArgvMode::kRegister:
   // ecx: pointer to the first argument
 
   STATIC_ASSERT(eax == kRuntimeCallArgCountRegister);
@@ -2928,8 +2935,8 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   int arg_stack_space = 3;
 
   // Enter the exit frame that transitions from JavaScript to C++.
-  if (argv_mode == kArgvInRegister) {
-    DCHECK(save_doubles == kDontSaveFPRegs);
+  if (argv_mode == ArgvMode::kRegister) {
+    DCHECK(save_doubles == SaveFPRegsMode::kIgnore);
     DCHECK(!builtin_exit_frame);
     __ EnterApiExitFrame(arg_stack_space, edi);
 
@@ -2938,7 +2945,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
     __ mov(edi, eax);
   } else {
     __ EnterExitFrame(
-        arg_stack_space, save_doubles == kSaveFPRegs,
+        arg_stack_space, save_doubles == SaveFPRegsMode::kSave,
         builtin_exit_frame ? StackFrame::BUILTIN_EXIT : StackFrame::EXIT);
   }
 
@@ -2985,7 +2992,8 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   }
 
   // Exit the JavaScript to C++ exit frame.
-  __ LeaveExitFrame(save_doubles == kSaveFPRegs, argv_mode == kArgvOnStack);
+  __ LeaveExitFrame(save_doubles == SaveFPRegsMode::kSave,
+                    argv_mode == ArgvMode::kStack);
   __ ret(0);
 
   // Handling of exception.
@@ -3148,7 +3156,7 @@ Operand ApiParameterOperand(int index) {
 // stores the pointer to the reserved slot into esi.
 void PrepareCallApiFunction(MacroAssembler* masm, int argc, Register scratch) {
   __ EnterApiExitFrame(argc, scratch);
-  if (__ emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ mov(esi, Immediate(bit_cast<int32_t>(kZapValue)));
   }
 }
@@ -3961,9 +3969,16 @@ void Generate_DeoptimizationEntry(MacroAssembler* masm,
     __ movsd(Operand(esi, dst_offset), xmm0);
   }
 
+  if (FLAG_debug_code) {
+    const int kTopMask = 0x3800;
+    __ push(eax);
+    __ fwait();
+    __ fnstsw_ax();
+    __ test(eax, Immediate(kTopMask));
+    __ Assert(zero, AbortReason::kFpuTopIsNotZeroInDeoptimizer);
+    __ pop(eax);
+  }
   // Clear FPU all exceptions.
-  // TODO(ulan): Find out why the TOP register is not zero here in some cases,
-  // and check that the generated code never deoptimizes with unbalanced stack.
   __ fnclex();
 
   // Mark the stack as not iterable for the CPU profiler which won't be able to
diff --git a/chromium/v8/src/builtins/ic-callable.tq b/chromium/v8/src/builtins/ic-callable.tq
index 85525c4c683..dd29e8bf5e2 100644
--- a/chromium/v8/src/builtins/ic-callable.tq
+++ b/chromium/v8/src/builtins/ic-callable.tq
@@ -6,6 +6,10 @@ namespace ic {
 namespace callable {
 
 extern macro IncrementCallCount(FeedbackVector, uintptr): void;
+const kCallFeedbackContentFieldMask: constexpr int32
+    generates 'FeedbackNexus::CallFeedbackContentField::kMask';
+const kCallFeedbackContentFieldShift: constexpr uint32
+    generates 'FeedbackNexus::CallFeedbackContentField::kShift';
 
 macro IsMonomorphic(feedback: MaybeObject, target: JSAny): bool {
   return IsWeakReferenceToObject(feedback, target);
@@ -50,8 +54,42 @@ macro TransitionToMegamorphic(implicit context: Context)(
   ReportFeedbackUpdate(feedbackVector, slotId, 'Call:TransitionMegamorphic');
 }
 
+macro TaggedEqualPrototypeApplyFunction(implicit context: Context)(
+    target: JSAny): bool {
+  return TaggedEqual(target, GetPrototypeApplyFunction());
+}
+
+macro FeedbackValueIsReceiver(implicit context: Context)(
+    feedbackVector: FeedbackVector, slotId: uintptr): bool {
+  const callCount: intptr = SmiUntag(Cast<Smi>(LoadFeedbackVectorSlot(
+      feedbackVector, slotId, kTaggedSize)) otherwise return false);
+  return (callCount & IntPtrConstant(kCallFeedbackContentFieldMask)) !=
+      IntPtrConstant(0);
+}
+
+macro SetCallFeedbackContent(implicit context: Context)(
+    feedbackVector: FeedbackVector, slotId: uintptr,
+    callFeedbackContent: constexpr CallFeedbackContent): void {
+  // Load the call count field from the feecback vector.
+  const callCount: intptr = SmiUntag(Cast<Smi>(LoadFeedbackVectorSlot(
+      feedbackVector, slotId, kTaggedSize)) otherwise return );
+  // The second lowest bits of the call count are used to state whether the
+  // feedback collected is a target or a receiver. Change that bit based on the
+  // callFeedbackContent input.
+  const callFeedbackContentFieldMask: intptr =
+      ~IntPtrConstant(kCallFeedbackContentFieldMask);
+  const newCount: intptr = (callCount & callFeedbackContentFieldMask) |
+      Convert<intptr>(Signed(
+          %RawConstexprCast<constexpr uint32>(callFeedbackContent)
+          << kCallFeedbackContentFieldShift));
+  StoreFeedbackVectorSlot(
+      feedbackVector, slotId, SmiTag(newCount), SKIP_WRITE_BARRIER,
+      kTaggedSize);
+  ReportFeedbackUpdate(feedbackVector, slotId, 'Call:SetCallFeedbackContent');
+}
+
 macro CollectCallFeedback(
-    maybeTarget: JSAny, context: Context,
+    maybeTarget: JSAny, maybeReceiver: Lazy<JSAny>, context: Context,
     maybeFeedbackVector: Undefined|FeedbackVector, slotId: uintptr): void {
   // TODO(v8:9891): Remove this assert once all callers are ported to Torque.
   // This assert ensures correctness of maybeFeedbackVector's type which can
@@ -72,7 +110,24 @@ macro CollectCallFeedback(
 
     // If cleared, we have a new chance to become monomorphic.
     const feedbackValue: HeapObject =
-        MaybeObjectToStrong(feedback) otherwise TryInitializeAsMonomorphic;
+        MaybeObjectToStrong(feedback) otherwise TryReinitializeAsMonomorphic;
+
+    if (FeedbackValueIsReceiver(feedbackVector, slotId) &&
+        TaggedEqualPrototypeApplyFunction(maybeTarget)) {
+      // If the Receiver is recorded and the target is
+      // Function.prototype.apply, check whether we can stay monomorphic based
+      // on the receiver.
+      if (IsMonomorphic(feedback, RunLazy(maybeReceiver))) {
+        return;
+      } else {
+        // If not, reinitialize the feedback with target.
+        SetCallFeedbackContent(
+            feedbackVector, slotId, CallFeedbackContent::kTarget);
+        TryInitializeAsMonomorphic(maybeTarget, feedbackVector, slotId)
+            otherwise TransitionToMegamorphic;
+        return;
+      }
+    }
 
     // Try transitioning to a feedback cell.
     // Check if {target}s feedback cell matches the {feedbackValue}.
@@ -92,8 +147,20 @@ macro CollectCallFeedback(
 
     StoreWeakReferenceInFeedbackVector(feedbackVector, slotId, feedbackCell);
     ReportFeedbackUpdate(feedbackVector, slotId, 'Call:FeedbackVectorCell');
+  } label TryReinitializeAsMonomorphic {
+    SetCallFeedbackContent(
+        feedbackVector, slotId, CallFeedbackContent::kTarget);
+    goto TryInitializeAsMonomorphic;
   } label TryInitializeAsMonomorphic {
-    TryInitializeAsMonomorphic(maybeTarget, feedbackVector, slotId)
+    let recordedFunction = maybeTarget;
+    if (TaggedEqualPrototypeApplyFunction(maybeTarget)) {
+      recordedFunction = RunLazy(maybeReceiver);
+      SetCallFeedbackContent(
+          feedbackVector, slotId, CallFeedbackContent::kReceiver);
+    } else {
+      assert(!FeedbackValueIsReceiver(feedbackVector, slotId));
+    }
+    TryInitializeAsMonomorphic(recordedFunction, feedbackVector, slotId)
         otherwise TransitionToMegamorphic;
   } label TransitionToMegamorphic {
     TransitionToMegamorphic(feedbackVector, slotId);
diff --git a/chromium/v8/src/builtins/ic.tq b/chromium/v8/src/builtins/ic.tq
index 49d4e78fa55..a9e92cf63ec 100644
--- a/chromium/v8/src/builtins/ic.tq
+++ b/chromium/v8/src/builtins/ic.tq
@@ -8,10 +8,10 @@ namespace ic {
 
 @export
 macro CollectCallFeedback(
-    maybeTarget: JSAny, context: Context,
+    maybeTarget: JSAny, maybeReceiver: Lazy<JSAny>, context: Context,
     maybeFeedbackVector: Undefined|FeedbackVector, slotId: uintptr): void {
   callable::CollectCallFeedback(
-      maybeTarget, context, maybeFeedbackVector, slotId);
+      maybeTarget, maybeReceiver, context, maybeFeedbackVector, slotId);
 }
 
 @export
@@ -51,10 +51,15 @@ macro IsUninitialized(feedback: MaybeObject): bool {
 }
 
 extern macro LoadFeedbackVectorSlot(FeedbackVector, uintptr): MaybeObject;
+extern macro LoadFeedbackVectorSlot(
+    FeedbackVector, uintptr, constexpr int32): MaybeObject;
 extern operator '[]' macro LoadFeedbackVectorSlot(
     FeedbackVector, intptr): MaybeObject;
 extern macro StoreFeedbackVectorSlot(
     FeedbackVector, uintptr, MaybeObject): void;
+extern macro StoreFeedbackVectorSlot(
+    FeedbackVector, uintptr, MaybeObject, constexpr WriteBarrierMode,
+    constexpr int32): void;
 extern macro StoreWeakReferenceInFeedbackVector(
     FeedbackVector, uintptr, HeapObject): MaybeObject;
 extern macro ReportFeedbackUpdate(FeedbackVector, uintptr, constexpr string);
diff --git a/chromium/v8/src/builtins/iterator.tq b/chromium/v8/src/builtins/iterator.tq
index 05993ea6d77..150e3d2cb57 100644
--- a/chromium/v8/src/builtins/iterator.tq
+++ b/chromium/v8/src/builtins/iterator.tq
@@ -78,8 +78,8 @@ extern macro LoadContextFromBaseline(): Context;
 extern macro LoadFeedbackVectorFromBaseline(): FeedbackVector;
 
 transitioning builtin GetIteratorBaseline(
-    context: Context, receiver: JSAny, loadSlot: TaggedIndex,
-    callSlot: TaggedIndex): JSAny {
+    receiver: JSAny, loadSlot: TaggedIndex, callSlot: TaggedIndex): JSAny {
+  const context: Context = LoadContextFromBaseline();
   const feedback: FeedbackVector = LoadFeedbackVectorFromBaseline();
   const iteratorMethod: JSAny =
       LoadIC(context, receiver, IteratorSymbolConstant(), loadSlot, feedback);
@@ -97,12 +97,18 @@ transitioning builtin CreateAsyncFromSyncIteratorBaseline(syncIterator: JSAny):
   return CreateAsyncFromSyncIterator(context, syncIterator);
 }
 
+macro GetLazyReceiver(receiver: JSAny): JSAny {
+  return receiver;
+}
+
 transitioning builtin CallIteratorWithFeedback(
     context: Context, receiver: JSAny, iteratorMethod: JSAny, callSlot: Smi,
     feedback: Undefined|FeedbackVector): JSAny {
   // TODO(v8:10047): Use TaggedIndex here once TurboFan supports it.
   const callSlotUnTagged: uintptr = Unsigned(SmiUntag(callSlot));
-  ic::CollectCallFeedback(iteratorMethod, context, feedback, callSlotUnTagged);
+  ic::CollectCallFeedback(
+      iteratorMethod, %MakeLazy<JSAny, JSAny>('GetLazyReceiver', receiver),
+      context, feedback, callSlotUnTagged);
   const iteratorCallable: Callable = Cast<Callable>(iteratorMethod)
       otherwise ThrowCalledNonCallable(iteratorMethod);
   return Call(context, iteratorCallable, receiver);
diff --git a/chromium/v8/src/builtins/mips/builtins-mips.cc b/chromium/v8/src/builtins/mips/builtins-mips.cc
index 1d8e80bdf87..6ff2ed4b5c3 100644
--- a/chromium/v8/src/builtins/mips/builtins-mips.cc
+++ b/chromium/v8/src/builtins/mips/builtins-mips.cc
@@ -6,6 +6,7 @@
 
 #include "src/api/api-arguments.h"
 #include "src/codegen/code-factory.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer/deoptimizer.h"
 #include "src/execution/frame-constants.h"
@@ -102,7 +103,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     // a0: number of arguments (untagged)
     // a1: constructor function
     // a3: new target
-    __ InvokeFunctionWithNewTarget(a1, a3, a0, CALL_FUNCTION);
+    __ InvokeFunctionWithNewTarget(a1, a3, a0, InvokeType::kCall);
 
     // Restore context from the frame.
     __ lw(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
@@ -226,7 +227,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
   __ Push(s0);
 
   // Call the function.
-  __ InvokeFunctionWithNewTarget(a1, a3, a0, CALL_FUNCTION);
+  __ InvokeFunctionWithNewTarget(a1, a3, a0, InvokeType::kCall);
 
   // ----------- S t a t e -------------
   //  --                 v0: constructor result
@@ -637,7 +638,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Store input value into generator object.
   __ sw(v0, FieldMemOperand(a1, JSGeneratorObject::kInputOrDebugPosOffset));
   __ RecordWriteField(a1, JSGeneratorObject::kInputOrDebugPosOffset, v0, a3,
-                      kRAHasNotBeenSaved, kDontSaveFPRegs);
+                      kRAHasNotBeenSaved, SaveFPRegsMode::kIgnore);
 
   // Load suspended function and context.
   __ lw(t0, FieldMemOperand(a1, JSGeneratorObject::kFunctionOffset));
@@ -761,8 +762,8 @@ static void ReplaceClosureCodeWithOptimizedCode(MacroAssembler* masm,
   __ sw(optimized_code, FieldMemOperand(closure, JSFunction::kCodeOffset));
   __ mov(scratch1, optimized_code);  // Write barrier clobbers scratch1 below.
   __ RecordWriteField(closure, JSFunction::kCodeOffset, scratch1, scratch2,
-                      kRAHasNotBeenSaved, kDontSaveFPRegs, OMIT_REMEMBERED_SET,
-                      OMIT_SMI_CHECK);
+                      kRAHasNotBeenSaved, SaveFPRegsMode::kIgnore,
+                      RememberedSetAction::kOmit, SmiCheck::kOmit);
 }
 
 static void LeaveInterpreterFrame(MacroAssembler* masm, Register scratch1,
@@ -1406,7 +1407,7 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   __ Jump(kJavaScriptCallCodeStartRegister);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtNextBytecode(MacroAssembler* masm) {
   // Advance the current bytecode offset stored within the given interpreter
   // stack frame. This simulates what all bytecode handlers do upon completion
   // of the underlying operation.
@@ -1453,7 +1454,7 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
   __ Abort(AbortReason::kInvalidBytecodeAdvance);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeDispatch(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtBytecode(MacroAssembler* masm) {
   Generate_InterpreterEnterBytecode(masm);
 }
 
@@ -1756,7 +1757,7 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
   //  -- t0 : len (number of elements to push from args)
   //  -- a3 : new.target (for [[Construct]])
   // -----------------------------------
-  if (masm->emit_debug_code()) {
+  if (FLAG_debug_code) {
     // Allow a2 to be a FixedArray, or a FixedDoubleArray if t0 == 0.
     Label ok, fail;
     __ AssertNotSmi(a2);
@@ -2005,7 +2006,7 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
 
   __ lhu(a2,
          FieldMemOperand(a2, SharedFunctionInfo::kFormalParameterCountOffset));
-  __ InvokeFunctionCode(a1, no_reg, a2, a0, JUMP_FUNCTION);
+  __ InvokeFunctionCode(a1, no_reg, a2, a0, InvokeType::kJump);
 
   // The function is a "classConstructor", need to raise an exception.
   __ bind(&class_constructor);
@@ -2364,6 +2365,12 @@ void Builtins::Generate_WasmDebugBreak(MacroAssembler* masm) {
 void Builtins::Generate_GenericJSToWasmWrapper(MacroAssembler* masm) {
   __ Trap();
 }
+
+void Builtins::Generate_WasmOnStackReplace(MacroAssembler* masm) {
+  // Only needed on x64.
+  __ Trap();
+}
+
 #endif  // V8_ENABLE_WEBASSEMBLY
 
 void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
@@ -2376,10 +2383,10 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // sp: stack pointer    (restored as callee's sp after C call)
   // cp: current context  (C callee-saved)
   //
-  // If argv_mode == kArgvInRegister:
+  // If argv_mode == ArgvMode::kRegister:
   // a2: pointer to the first argument
 
-  if (argv_mode == kArgvInRegister) {
+  if (argv_mode == ArgvMode::kRegister) {
     // Move argv into the correct register.
     __ mov(s1, a2);
   } else {
@@ -2391,7 +2398,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // Enter the exit frame that transitions from JavaScript to C++.
   FrameScope scope(masm, StackFrame::MANUAL);
   __ EnterExitFrame(
-      save_doubles == kSaveFPRegs, 0,
+      save_doubles == SaveFPRegsMode::kSave, 0,
       builtin_exit_frame ? StackFrame::BUILTIN_EXIT : StackFrame::EXIT);
 
   // s0: number of arguments  including receiver (C callee-saved)
@@ -2440,12 +2447,12 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // v0:v1: result
   // sp: stack pointer
   // fp: frame pointer
-  Register argc = argv_mode == kArgvInRegister
+  Register argc = argv_mode == ArgvMode::kRegister
                       // We don't want to pop arguments so set argc to no_reg.
                       ? no_reg
                       // s0: still holds argc (callee-saved).
                       : s0;
-  __ LeaveExitFrame(save_doubles == kSaveFPRegs, argc, EMIT_RETURN);
+  __ LeaveExitFrame(save_doubles == SaveFPRegsMode::kSave, argc, EMIT_RETURN);
 
   // Handling of exception.
   __ bind(&exception_returned);
@@ -2698,7 +2705,7 @@ void CallApiFunctionAndReturn(MacroAssembler* masm, Register function_address,
   // No more valid handles (the result handle was the last one). Restore
   // previous handle scope.
   __ sw(s0, MemOperand(s5, kNextOffset));
-  if (__ emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ lw(a1, MemOperand(s5, kLevelOffset));
     __ Check(eq, AbortReason::kUnexpectedLevelAfterReturnFromApiCall, a1,
              Operand(s2));
diff --git a/chromium/v8/src/builtins/mips64/builtins-mips64.cc b/chromium/v8/src/builtins/mips64/builtins-mips64.cc
index c029188f146..9d0156e9278 100644
--- a/chromium/v8/src/builtins/mips64/builtins-mips64.cc
+++ b/chromium/v8/src/builtins/mips64/builtins-mips64.cc
@@ -6,6 +6,7 @@
 
 #include "src/api/api-arguments.h"
 #include "src/codegen/code-factory.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer/deoptimizer.h"
 #include "src/execution/frame-constants.h"
@@ -102,7 +103,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     // a0: number of arguments (untagged)
     // a1: constructor function
     // a3: new target
-    __ InvokeFunctionWithNewTarget(a1, a3, a0, CALL_FUNCTION);
+    __ InvokeFunctionWithNewTarget(a1, a3, a0, InvokeType::kCall);
 
     // Restore context from the frame.
     __ Ld(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
@@ -227,7 +228,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
   __ Push(a6);
 
   // Call the function.
-  __ InvokeFunctionWithNewTarget(a1, a3, a0, CALL_FUNCTION);
+  __ InvokeFunctionWithNewTarget(a1, a3, a0, InvokeType::kCall);
 
   // ----------- S t a t e -------------
   //  --                 v0: constructor result
@@ -324,7 +325,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Store input value into generator object.
   __ Sd(v0, FieldMemOperand(a1, JSGeneratorObject::kInputOrDebugPosOffset));
   __ RecordWriteField(a1, JSGeneratorObject::kInputOrDebugPosOffset, v0, a3,
-                      kRAHasNotBeenSaved, kDontSaveFPRegs);
+                      kRAHasNotBeenSaved, SaveFPRegsMode::kIgnore);
 
   // Load suspended function and context.
   __ Ld(a4, FieldMemOperand(a1, JSGeneratorObject::kFunctionOffset));
@@ -777,8 +778,8 @@ static void ReplaceClosureCodeWithOptimizedCode(MacroAssembler* masm,
   __ Sd(optimized_code, FieldMemOperand(closure, JSFunction::kCodeOffset));
   __ mov(scratch1, optimized_code);  // Write barrier clobbers scratch1 below.
   __ RecordWriteField(closure, JSFunction::kCodeOffset, scratch1, scratch2,
-                      kRAHasNotBeenSaved, kDontSaveFPRegs, OMIT_REMEMBERED_SET,
-                      OMIT_SMI_CHECK);
+                      kRAHasNotBeenSaved, SaveFPRegsMode::kIgnore,
+                      RememberedSetAction::kOmit, SmiCheck::kOmit);
 }
 
 static void LeaveInterpreterFrame(MacroAssembler* masm, Register scratch1,
@@ -1424,7 +1425,7 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   __ Jump(kJavaScriptCallCodeStartRegister);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtNextBytecode(MacroAssembler* masm) {
   // Advance the current bytecode offset stored within the given interpreter
   // stack frame. This simulates what all bytecode handlers do upon completion
   // of the underlying operation.
@@ -1471,7 +1472,7 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
   __ Abort(AbortReason::kInvalidBytecodeAdvance);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeDispatch(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtBytecode(MacroAssembler* masm) {
   Generate_InterpreterEnterBytecode(masm);
 }
 
@@ -1815,7 +1816,7 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
   //  -- a4 : len (number of elements to push from args)
   //  -- a3 : new.target (for [[Construct]])
   // -----------------------------------
-  if (masm->emit_debug_code()) {
+  if (FLAG_debug_code) {
     // Allow a2 to be a FixedArray, or a FixedDoubleArray if a4 == 0.
     Label ok, fail;
     __ AssertNotSmi(a2);
@@ -2073,7 +2074,7 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
 
   __ Lhu(a2,
          FieldMemOperand(a2, SharedFunctionInfo::kFormalParameterCountOffset));
-  __ InvokeFunctionCode(a1, no_reg, a2, a0, JUMP_FUNCTION);
+  __ InvokeFunctionCode(a1, no_reg, a2, a0, InvokeType::kJump);
 
   // The function is a "classConstructor", need to raise an exception.
   __ bind(&class_constructor);
@@ -2395,7 +2396,11 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
     __ Lbu(a1, MemOperand(a1));
     __ Branch(&push_doubles, le, a1, Operand(zero_reg));
     // Save vector registers.
-    __ MultiPushMSA(fp_regs);
+    {
+      CpuFeatureScope msa_scope(
+          masm, MIPS_SIMD, CpuFeatureScope::CheckPolicy::kDontCheckSupported);
+      __ MultiPushMSA(fp_regs);
+    }
     __ Branch(&simd_pushed);
     __ bind(&push_doubles);
     __ MultiPushFPU(fp_regs);
@@ -2419,7 +2424,11 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
     __ Lbu(a1, MemOperand(a1));
     __ Branch(&pop_doubles, le, a1, Operand(zero_reg));
     // Pop vector registers.
-    __ MultiPopMSA(fp_regs);
+    {
+      CpuFeatureScope msa_scope(
+          masm, MIPS_SIMD, CpuFeatureScope::CheckPolicy::kDontCheckSupported);
+      __ MultiPopMSA(fp_regs);
+    }
     __ Branch(&simd_popped);
     __ bind(&pop_doubles);
     __ Daddu(sp, sp, base::bits::CountPopulation(fp_regs) * kDoubleSize);
@@ -2456,6 +2465,12 @@ void Builtins::Generate_WasmDebugBreak(MacroAssembler* masm) {
 void Builtins::Generate_GenericJSToWasmWrapper(MacroAssembler* masm) {
   __ Trap();
 }
+
+void Builtins::Generate_WasmOnStackReplace(MacroAssembler* masm) {
+  // Only needed on x64.
+  __ Trap();
+}
+
 #endif  // V8_ENABLE_WEBASSEMBLY
 
 void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
@@ -2468,10 +2483,10 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // sp: stack pointer    (restored as callee's sp after C call)
   // cp: current context  (C callee-saved)
   //
-  // If argv_mode == kArgvInRegister:
+  // If argv_mode == ArgvMode::kRegister:
   // a2: pointer to the first argument
 
-  if (argv_mode == kArgvInRegister) {
+  if (argv_mode == ArgvMode::kRegister) {
     // Move argv into the correct register.
     __ mov(s1, a2);
   } else {
@@ -2483,7 +2498,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // Enter the exit frame that transitions from JavaScript to C++.
   FrameScope scope(masm, StackFrame::MANUAL);
   __ EnterExitFrame(
-      save_doubles == kSaveFPRegs, 0,
+      save_doubles == SaveFPRegsMode::kSave, 0,
       builtin_exit_frame ? StackFrame::BUILTIN_EXIT : StackFrame::EXIT);
 
   // s0: number of arguments  including receiver (C callee-saved)
@@ -2532,12 +2547,12 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // v0:v1: result
   // sp: stack pointer
   // fp: frame pointer
-  Register argc = argv_mode == kArgvInRegister
+  Register argc = argv_mode == ArgvMode::kRegister
                       // We don't want to pop arguments so set argc to no_reg.
                       ? no_reg
                       // s0: still holds argc (callee-saved).
                       : s0;
-  __ LeaveExitFrame(save_doubles == kSaveFPRegs, argc, EMIT_RETURN);
+  __ LeaveExitFrame(save_doubles == SaveFPRegsMode::kSave, argc, EMIT_RETURN);
 
   // Handling of exception.
   __ bind(&exception_returned);
@@ -2794,7 +2809,7 @@ void CallApiFunctionAndReturn(MacroAssembler* masm, Register function_address,
   // No more valid handles (the result handle was the last one). Restore
   // previous handle scope.
   __ Sd(s0, MemOperand(s5, kNextOffset));
-  if (__ emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ Lw(a1, MemOperand(s5, kLevelOffset));
     __ Check(eq, AbortReason::kUnexpectedLevelAfterReturnFromApiCall, a1,
              Operand(s2));
diff --git a/chromium/v8/src/builtins/ppc/builtins-ppc.cc b/chromium/v8/src/builtins/ppc/builtins-ppc.cc
index bc467c9ff9f..35d817d3a26 100644
--- a/chromium/v8/src/builtins/ppc/builtins-ppc.cc
+++ b/chromium/v8/src/builtins/ppc/builtins-ppc.cc
@@ -6,6 +6,7 @@
 
 #include "src/api/api-arguments.h"
 #include "src/codegen/code-factory.h"
+#include "src/codegen/interface-descriptors-inl.h"
 // For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
 #include "src/codegen/macro-assembler-inl.h"
 #include "src/codegen/register-configuration.h"
@@ -113,13 +114,13 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     // r6: new target
     {
       ConstantPoolUnavailableScope constant_pool_unavailable(masm);
-      __ InvokeFunctionWithNewTarget(r4, r6, r3, CALL_FUNCTION);
+      __ InvokeFunctionWithNewTarget(r4, r6, r3, InvokeType::kCall);
     }
 
     // Restore context from the frame.
-    __ LoadP(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
+    __ LoadU64(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
     // Restore smi-tagged arguments count from the frame.
-    __ LoadP(scratch, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
+    __ LoadU64(scratch, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
 
     // Leave construct frame.
   }
@@ -229,8 +230,8 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
   // -----------------------------------
 
   // Restore constructor function and argument count.
-  __ LoadP(r4, MemOperand(fp, ConstructFrameConstants::kConstructorOffset));
-  __ LoadP(r3, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
+  __ LoadU64(r4, MemOperand(fp, ConstructFrameConstants::kConstructorOffset));
+  __ LoadU64(r3, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
   __ SmiUntag(r3);
 
   Label stack_overflow;
@@ -245,7 +246,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
   // Call the function.
   {
     ConstantPoolUnavailableScope constant_pool_unavailable(masm);
-    __ InvokeFunctionWithNewTarget(r4, r6, r3, CALL_FUNCTION);
+    __ InvokeFunctionWithNewTarget(r4, r6, r3, InvokeType::kCall);
   }
 
   // ----------- S t a t e -------------
@@ -275,12 +276,12 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
   // Throw away the result of the constructor invocation and use the
   // on-stack receiver as the result.
   __ bind(&use_receiver);
-  __ LoadP(r3, MemOperand(sp));
+  __ LoadU64(r3, MemOperand(sp));
   __ JumpIfRoot(r3, RootIndex::kTheHoleValue, &do_throw);
 
   __ bind(&leave_and_return);
   // Restore smi-tagged arguments count from the frame.
-  __ LoadP(r4, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
+  __ LoadU64(r4, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
   // Leave construct frame.
   __ LeaveFrame(StackFrame::CONSTRUCT);
 
@@ -305,13 +306,13 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
 
   __ bind(&do_throw);
   // Restore the context from the frame.
-  __ LoadP(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
+  __ LoadU64(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
   __ CallRuntime(Runtime::kThrowConstructorReturnedNonObject);
   __ bkpt(0);
 
   __ bind(&stack_overflow);
   // Restore the context from the frame.
-  __ LoadP(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
+  __ LoadU64(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
   __ CallRuntime(Runtime::kThrowStackOverflow);
   // Unreachable code.
   __ bkpt(0);
@@ -347,7 +348,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   __ StoreTaggedField(
       r3, FieldMemOperand(r4, JSGeneratorObject::kInputOrDebugPosOffset), r0);
   __ RecordWriteField(r4, JSGeneratorObject::kInputOrDebugPosOffset, r3, r6,
-                      kLRHasNotBeenSaved, kDontSaveFPRegs);
+                      kLRHasNotBeenSaved, SaveFPRegsMode::kIgnore);
 
   // Load suspended function and context.
   __ LoadTaggedPointerField(
@@ -373,7 +374,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
       ExternalReference::debug_suspended_generator_address(masm->isolate());
 
   __ Move(scratch, debug_suspended_generator);
-  __ LoadP(scratch, MemOperand(scratch));
+  __ LoadU64(scratch, MemOperand(scratch));
   __ cmp(scratch, r4);
   __ beq(&prepare_step_in_suspended_generator);
   __ bind(&stepping_prepared);
@@ -402,19 +403,16 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
       FieldMemOperand(r4, JSGeneratorObject::kParametersAndRegistersOffset));
   {
     Label done_loop, loop;
-    __ mr(r9, r6);
-
     __ bind(&loop);
-    __ subi(r9, r9, Operand(1));
-    __ cmpi(r9, Operand::Zero());
+    __ subi(r6, r6, Operand(1));
+    __ cmpi(r6, Operand::Zero());
     __ blt(&done_loop);
-    __ ShiftLeftImm(r10, r9, Operand(kTaggedSizeLog2));
+    __ ShiftLeftImm(r10, r6, Operand(kTaggedSizeLog2));
     __ add(scratch, r5, r10);
     __ LoadAnyTaggedField(scratch,
                           FieldMemOperand(scratch, FixedArray::kHeaderSize));
     __ Push(scratch);
     __ b(&loop);
-
     __ bind(&done_loop);
 
     // Push receiver.
@@ -554,7 +552,7 @@ void Generate_JSEntryVariant(MacroAssembler* masm, StackFrame::Type type,
   // Save copies of the top frame descriptor on the stack.
   __ Move(r3, ExternalReference::Create(IsolateAddressId::kCEntryFPAddress,
                                         masm->isolate()));
-  __ LoadP(r0, MemOperand(r3));
+  __ LoadU64(r0, MemOperand(r3));
   __ push(r0);
 
   // Clear c_entry_fp, now we've pushed its previous value to the stack.
@@ -574,7 +572,7 @@ void Generate_JSEntryVariant(MacroAssembler* masm, StackFrame::Type type,
       ExternalReference::Create(IsolateAddressId::kJSEntrySPAddress,
                                 masm->isolate());
   __ Move(r3, js_entry_sp);
-  __ LoadP(scratch, MemOperand(r3));
+  __ LoadU64(scratch, MemOperand(r3));
   __ cmpi(scratch, Operand::Zero());
   __ bne(&non_outermost_js);
   __ StoreP(fp, MemOperand(r3));
@@ -663,7 +661,7 @@ void Generate_JSEntryVariant(MacroAssembler* masm, StackFrame::Type type,
   __ MultiPop(kCalleeSaved);
 
   // Return
-  __ LoadP(r0, MemOperand(sp, kStackFrameLRSlot * kSystemPointerSize));
+  __ LoadU64(r0, MemOperand(sp, kStackFrameLRSlot * kSystemPointerSize));
   __ mtlr(r0);
   __ blr();
 }
@@ -703,7 +701,7 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
     ExternalReference context_address = ExternalReference::Create(
         IsolateAddressId::kContextAddress, masm->isolate());
     __ Move(cp, context_address);
-    __ LoadP(cp, MemOperand(cp));
+    __ LoadU64(cp, MemOperand(cp));
 
     // Push the function.
     __ Push(r5);
@@ -734,7 +732,7 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
     __ mtctr(r7);
     __ bind(&loop);
     __ LoadPU(r9, MemOperand(r8, -kSystemPointerSize));  // read next parameter
-    __ LoadP(r0, MemOperand(r9));                        // dereference handle
+    __ LoadU64(r0, MemOperand(r9));                      // dereference handle
     __ push(r0);                                         // push parameter
     __ bdnz(&loop);
     __ bind(&done);
@@ -800,23 +798,23 @@ static void ReplaceClosureCodeWithOptimizedCode(MacroAssembler* masm,
                       FieldMemOperand(closure, JSFunction::kCodeOffset), r0);
   __ mr(scratch1, optimized_code);  // Write barrier clobbers scratch1 below.
   __ RecordWriteField(closure, JSFunction::kCodeOffset, scratch1, scratch2,
-                      kLRHasNotBeenSaved, kDontSaveFPRegs, OMIT_REMEMBERED_SET,
-                      OMIT_SMI_CHECK);
+                      kLRHasNotBeenSaved, SaveFPRegsMode::kIgnore,
+                      RememberedSetAction::kOmit, SmiCheck::kOmit);
 }
 
 static void LeaveInterpreterFrame(MacroAssembler* masm, Register scratch1,
                                   Register scratch2) {
   Register params_size = scratch1;
   // Get the size of the formal parameters + receiver (in bytes).
-  __ LoadP(params_size,
-           MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
+  __ LoadU64(params_size,
+             MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
   __ lwz(params_size,
          FieldMemOperand(params_size, BytecodeArray::kParameterSizeOffset));
 
   Register actual_params_size = scratch2;
   // Compute the size of the actual parameters + receiver (in bytes).
-  __ LoadP(actual_params_size,
-           MemOperand(fp, StandardFrameConstants::kArgCOffset));
+  __ LoadU64(actual_params_size,
+             MemOperand(fp, StandardFrameConstants::kArgCOffset));
   __ ShiftLeftImm(actual_params_size, actual_params_size,
                   Operand(kSystemPointerSizeLog2));
   __ addi(actual_params_size, actual_params_size, Operand(kSystemPointerSize));
@@ -869,7 +867,7 @@ static void TailCallOptimizedCodeSlot(MacroAssembler* masm,
   __ LoadTaggedPointerField(
       scratch,
       FieldMemOperand(optimized_code_entry, Code::kCodeDataContainerOffset));
-  __ LoadWordArith(
+  __ LoadS32(
       scratch,
       FieldMemOperand(scratch, CodeDataContainer::kKindSpecificFlagsOffset));
   __ TestBit(scratch, Code::kMarkedForDeoptimizationBit, r0);
@@ -1082,9 +1080,9 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   Register optimization_state = r7;
 
   // Read off the optimization state in the feedback vector.
-  __ LoadWord(optimization_state,
-              FieldMemOperand(feedback_vector, FeedbackVector::kFlagsOffset),
-              r0);
+  __ LoadU32(optimization_state,
+             FieldMemOperand(feedback_vector, FeedbackVector::kFlagsOffset),
+             r0);
 
   // Check if the optimized code slot is not empty or has a optimization marker.
   Label has_optimized_code_or_marker;
@@ -1097,7 +1095,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ bind(&not_optimized);
 
   // Increment invocation count for the function.
-  __ LoadWord(
+  __ LoadU32(
       r8,
       FieldMemOperand(feedback_vector, FeedbackVector::kInvocationCountOffset),
       r0);
@@ -1165,10 +1163,10 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   // If the bytecode array has a valid incoming new target or generator object
   // register, initialize it with incoming value which was passed in r6.
   Label no_incoming_new_target_or_generator_register;
-  __ LoadWordArith(
-      r8, FieldMemOperand(
-              kInterpreterBytecodeArrayRegister,
-              BytecodeArray::kIncomingNewTargetOrGeneratorRegisterOffset));
+  __ LoadS32(r8,
+             FieldMemOperand(
+                 kInterpreterBytecodeArrayRegister,
+                 BytecodeArray::kIncomingNewTargetOrGeneratorRegisterOffset));
   __ cmpi(r8, Operand::Zero());
   __ beq(&no_incoming_new_target_or_generator_register);
   __ ShiftLeftImm(r8, r8, Operand(kSystemPointerSizeLog2));
@@ -1205,10 +1203,10 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   // or the interpreter tail calling a builtin and then a dispatch.
 
   // Get bytecode array and bytecode offset from the stack frame.
-  __ LoadP(kInterpreterBytecodeArrayRegister,
-           MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
-  __ LoadP(kInterpreterBytecodeOffsetRegister,
-           MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
+  __ LoadU64(kInterpreterBytecodeArrayRegister,
+             MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
+  __ LoadU64(kInterpreterBytecodeOffsetRegister,
+             MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
   // Either return, or advance to the next bytecode and dispatch.
@@ -1238,8 +1236,8 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   // After the call, restore the bytecode array, bytecode offset and accumulator
   // registers again. Also, restore the bytecode offset in the stack to its
   // previous value.
-  __ LoadP(kInterpreterBytecodeArrayRegister,
-           MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
+  __ LoadU64(kInterpreterBytecodeArrayRegister,
+             MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
   __ mov(kInterpreterBytecodeOffsetRegister,
          Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
   __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
@@ -1313,7 +1311,7 @@ void Builtins::Generate_InterpreterPushArgsThenCallImpl(
     // Pass the spread in the register r3.
     // r2 already points to the penultimate argument, the spread
     // lies in the next interpreter register.
-    __ LoadP(r5, MemOperand(r5, -kSystemPointerSize));
+    __ LoadU64(r5, MemOperand(r5, -kSystemPointerSize));
   }
 
   // Call the target.
@@ -1364,7 +1362,7 @@ void Builtins::Generate_InterpreterPushArgsThenConstructImpl(
     // r4 already points to the penultimate argument, the spread
     // lies in the next interpreter register.
     __ subi(r7, r7, Operand(kSystemPointerSize));
-    __ LoadP(r5, MemOperand(r7));
+    __ LoadU64(r5, MemOperand(r7));
   } else {
     __ AssertUndefinedOrAllocationSite(r5, r8);
   }
@@ -1406,7 +1404,7 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   // custom copy of the interpreter entry trampoline for profiling. If so,
   // get the custom trampoline, otherwise grab the entry address of the global
   // trampoline.
-  __ LoadP(r5, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
+  __ LoadU64(r5, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
   __ LoadTaggedPointerField(
       r5, FieldMemOperand(r5, JSFunction::kSharedFunctionInfoOffset));
   __ LoadTaggedPointerField(
@@ -1425,7 +1423,7 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   __ Move(r5, ExternalReference::
                   address_of_interpreter_entry_trampoline_instruction_start(
                       masm->isolate()));
-  __ LoadP(r5, MemOperand(r5));
+  __ LoadU64(r5, MemOperand(r5));
 
   __ bind(&trampoline_loaded);
   __ addi(r0, r5, Operand(interpreter_entry_return_pc_offset.value()));
@@ -1437,8 +1435,8 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
       ExternalReference::interpreter_dispatch_table_address(masm->isolate()));
 
   // Get the bytecode array pointer from the frame.
-  __ LoadP(kInterpreterBytecodeArrayRegister,
-           MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
+  __ LoadU64(kInterpreterBytecodeArrayRegister,
+             MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
 
   if (FLAG_debug_code) {
     // Check function data field is actually a BytecodeArray object.
@@ -1453,8 +1451,8 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   }
 
   // Get the target bytecode offset from the frame.
-  __ LoadP(kInterpreterBytecodeOffsetRegister,
-           MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
+  __ LoadU64(kInterpreterBytecodeOffsetRegister,
+             MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
   if (FLAG_debug_code) {
@@ -1478,12 +1476,12 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   __ Jump(kJavaScriptCallCodeStartRegister);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtNextBytecode(MacroAssembler* masm) {
   // Get bytecode array and bytecode offset from the stack frame.
-  __ LoadP(kInterpreterBytecodeArrayRegister,
-           MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
-  __ LoadP(kInterpreterBytecodeOffsetRegister,
-           MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
+  __ LoadU64(kInterpreterBytecodeArrayRegister,
+             MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
+  __ LoadU64(kInterpreterBytecodeOffsetRegister,
+             MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
   Label enter_bytecode, function_entry_bytecode;
@@ -1524,7 +1522,7 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
   __ Abort(AbortReason::kInvalidBytecodeAdvance);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeDispatch(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtBytecode(MacroAssembler* masm) {
   Generate_InterpreterEnterBytecode(masm);
 }
 
@@ -1567,7 +1565,7 @@ void Generate_ContinueToBuiltinHelper(MacroAssembler* masm,
     __ subi(r3, r3,
             Operand(BuiltinContinuationFrameConstants::kFixedSlotCount));
   }
-  __ LoadP(
+  __ LoadU64(
       fp,
       MemOperand(sp, BuiltinContinuationFrameConstants::kFixedFrameSizeFromFp));
   // Load builtin index (stored as a Smi) and use it to get the builtin start
@@ -1609,7 +1607,7 @@ void Builtins::Generate_NotifyDeoptimized(MacroAssembler* masm) {
   }
 
   DCHECK_EQ(kInterpreterAccumulatorRegister.code(), r3.code());
-  __ LoadP(r3, MemOperand(sp, 0 * kSystemPointerSize));
+  __ LoadU64(r3, MemOperand(sp, 0 * kSystemPointerSize));
   __ addi(sp, sp, Operand(1 * kSystemPointerSize));
   __ Ret();
 }
@@ -1677,13 +1675,13 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
     __ mr(r5, r8);
 
     Label done;
-    __ LoadP(r4, MemOperand(sp));  // receiver
+    __ LoadU64(r4, MemOperand(sp));  // receiver
     __ cmpi(r3, Operand(1));
     __ blt(&done);
-    __ LoadP(r8, MemOperand(sp, kSystemPointerSize));  // thisArg
+    __ LoadU64(r8, MemOperand(sp, kSystemPointerSize));  // thisArg
     __ cmpi(r3, Operand(2));
     __ blt(&done);
-    __ LoadP(r5, MemOperand(sp, 2 * kSystemPointerSize));  // argArray
+    __ LoadU64(r5, MemOperand(sp, 2 * kSystemPointerSize));  // argArray
 
     __ bind(&done);
     __ ShiftLeftImm(ip, r3, Operand(kSystemPointerSizeLog2));
@@ -1762,13 +1760,13 @@ void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
     Label done;
     __ cmpi(r3, Operand(1));
     __ blt(&done);
-    __ LoadP(r4, MemOperand(sp, kSystemPointerSize));  // thisArg
+    __ LoadU64(r4, MemOperand(sp, kSystemPointerSize));  // thisArg
     __ cmpi(r3, Operand(2));
     __ blt(&done);
-    __ LoadP(r8, MemOperand(sp, 2 * kSystemPointerSize));  // argArray
+    __ LoadU64(r8, MemOperand(sp, 2 * kSystemPointerSize));  // argArray
     __ cmpi(r3, Operand(3));
     __ blt(&done);
-    __ LoadP(r5, MemOperand(sp, 3 * kSystemPointerSize));  // argArray
+    __ LoadU64(r5, MemOperand(sp, 3 * kSystemPointerSize));  // argArray
 
     __ bind(&done);
     __ ShiftLeftImm(ip, r3, Operand(kSystemPointerSizeLog2));
@@ -1812,14 +1810,14 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
     __ mr(r7, r4);
     __ cmpi(r3, Operand(1));
     __ blt(&done);
-    __ LoadP(r4, MemOperand(sp, kSystemPointerSize));  // thisArg
+    __ LoadU64(r4, MemOperand(sp, kSystemPointerSize));  // thisArg
     __ mr(r6, r4);
     __ cmpi(r3, Operand(2));
     __ blt(&done);
-    __ LoadP(r5, MemOperand(sp, 2 * kSystemPointerSize));  // argArray
+    __ LoadU64(r5, MemOperand(sp, 2 * kSystemPointerSize));  // argArray
     __ cmpi(r3, Operand(3));
     __ blt(&done);
-    __ LoadP(r6, MemOperand(sp, 3 * kSystemPointerSize));  // argArray
+    __ LoadU64(r6, MemOperand(sp, 3 * kSystemPointerSize));  // argArray
     __ bind(&done);
     __ ShiftLeftImm(r0, r3, Operand(kSystemPointerSizeLog2));
     __ add(sp, sp, r0);
@@ -1847,6 +1845,7 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
 }
 
 // static
+// TODO(v8:11615): Observe Code::kMaxArguments in CallOrConstructVarargs
 void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
                                                Handle<Code> code) {
   // ----------- S t a t e -------------
@@ -1859,7 +1858,7 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
 
   Register scratch = ip;
 
-  if (masm->emit_debug_code()) {
+  if (FLAG_debug_code) {
     // Allow r5 to be a FixedArray, or a FixedDoubleArray if r7 == 0.
     Label ok, fail;
     __ AssertNotSmi(r5);
@@ -1963,7 +1962,7 @@ void Builtins::Generate_CallOrConstructForwardVarargs(MacroAssembler* masm,
   }
 
   Label stack_done, stack_overflow;
-  __ LoadP(r8, MemOperand(fp, StandardFrameConstants::kArgCOffset));
+  __ LoadU64(r8, MemOperand(fp, StandardFrameConstants::kArgCOffset));
   __ sub(r8, r8, r5, LeaveOE, SetRC);
   __ ble(&stack_done, cr0);
   {
@@ -2125,7 +2124,7 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
 
   __ LoadHalfWord(
       r5, FieldMemOperand(r5, SharedFunctionInfo::kFormalParameterCountOffset));
-  __ InvokeFunctionCode(r4, no_reg, r5, r3, JUMP_FUNCTION);
+  __ InvokeFunctionCode(r4, no_reg, r5, r3, InvokeType::kJump);
 
   // The function is a "classConstructor", need to raise an exception.
   __ bind(&class_constructor);
@@ -2511,6 +2510,11 @@ void Builtins::Generate_GenericJSToWasmWrapper(MacroAssembler* masm) {
   // TODO(v8:10701): Implement for this platform.
   __ Trap();
 }
+
+void Builtins::Generate_WasmOnStackReplace(MacroAssembler* masm) {
+  // Only needed on x64.
+  __ Trap();
+}
 #endif  // V8_ENABLE_WEBASSEMBLY
 
 void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
@@ -2523,12 +2527,12 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // sp: stack pointer  (restored as callee's sp after C call)
   // cp: current context  (C callee-saved)
   //
-  // If argv_mode == kArgvInRegister:
+  // If argv_mode == ArgvMode::kRegister:
   // r5: pointer to the first argument
 
   __ mr(r15, r4);
 
-  if (argv_mode == kArgvInRegister) {
+  if (argv_mode == ArgvMode::kRegister) {
     // Move argv into the correct register.
     __ mr(r4, r5);
   } else {
@@ -2552,7 +2556,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   }
 
   __ EnterExitFrame(
-      save_doubles, arg_stack_space,
+      save_doubles == SaveFPRegsMode::kSave, arg_stack_space,
       builtin_exit_frame ? StackFrame::BUILTIN_EXIT : StackFrame::EXIT);
 
   // Store a copy of argc in callee-saved registers for later.
@@ -2584,8 +2588,8 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
 
   // If return value is on the stack, pop it to registers.
   if (needs_return_buffer) {
-    __ LoadP(r4, MemOperand(r3, kSystemPointerSize));
-    __ LoadP(r3, MemOperand(r3));
+    __ LoadU64(r4, MemOperand(r3, kSystemPointerSize));
+    __ LoadU64(r3, MemOperand(r3));
   }
 
   // Check result for exception sentinel.
@@ -2601,7 +2605,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
         IsolateAddressId::kPendingExceptionAddress, masm->isolate());
 
     __ Move(r6, pending_exception_address);
-    __ LoadP(r6, MemOperand(r6));
+    __ LoadU64(r6, MemOperand(r6));
     __ CompareRoot(r6, RootIndex::kTheHoleValue);
     // Cannot use check here as it attempts to generate call into runtime.
     __ beq(&okay);
@@ -2613,12 +2617,12 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // r3:r4: result
   // sp: stack pointer
   // fp: frame pointer
-  Register argc = argv_mode == kArgvInRegister
+  Register argc = argv_mode == ArgvMode::kRegister
                       // We don't want to pop arguments so set argc to no_reg.
                       ? no_reg
                       // r14: still holds argc (callee-saved).
                       : r14;
-  __ LeaveExitFrame(save_doubles, argc);
+  __ LeaveExitFrame(save_doubles == SaveFPRegsMode::kSave, argc);
   __ blr();
 
   // Handling of exception.
@@ -2653,11 +2657,11 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
 
   // Retrieve the handler context, SP and FP.
   __ Move(cp, pending_handler_context_address);
-  __ LoadP(cp, MemOperand(cp));
+  __ LoadU64(cp, MemOperand(cp));
   __ Move(sp, pending_handler_sp_address);
-  __ LoadP(sp, MemOperand(sp));
+  __ LoadU64(sp, MemOperand(sp));
   __ Move(fp, pending_handler_fp_address);
-  __ LoadP(fp, MemOperand(fp));
+  __ LoadU64(fp, MemOperand(fp));
 
   // If the handler is a JS frame, restore the context to the frame. Note that
   // the context will be set to (cp == 0) for non-JS frames.
@@ -2685,10 +2689,10 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // Compute the handler entry address and jump to it.
   ConstantPoolUnavailableScope constant_pool_unavailable(masm);
   __ Move(ip, pending_handler_entrypoint_address);
-  __ LoadP(ip, MemOperand(ip));
+  __ LoadU64(ip, MemOperand(ip));
   if (FLAG_enable_embedded_constant_pool) {
     __ Move(kConstantPoolRegister, pending_handler_constant_pool_address);
-    __ LoadP(kConstantPoolRegister, MemOperand(kConstantPoolRegister));
+    __ LoadU64(kConstantPoolRegister, MemOperand(kConstantPoolRegister));
   }
   __ Jump(ip);
 }
@@ -2873,8 +2877,8 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
   // r15 - next_address->kLimitOffset
   // r16 - next_address->kLevelOffset
   __ Move(r17, next_address);
-  __ LoadP(r14, MemOperand(r17, kNextOffset));
-  __ LoadP(r15, MemOperand(r17, kLimitOffset));
+  __ LoadU64(r14, MemOperand(r17, kNextOffset));
+  __ LoadU64(r15, MemOperand(r17, kLimitOffset));
   __ lwz(r16, MemOperand(r17, kLevelOffset));
   __ addi(r16, r16, Operand(1));
   __ stw(r16, MemOperand(r17, kLevelOffset));
@@ -2887,19 +2891,19 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
   Label return_value_loaded;
 
   // load value from ReturnValue
-  __ LoadP(r3, return_value_operand);
+  __ LoadU64(r3, return_value_operand);
   __ bind(&return_value_loaded);
   // No more valid handles (the result handle was the last one). Restore
   // previous handle scope.
   __ StoreP(r14, MemOperand(r17, kNextOffset));
-  if (__ emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ lwz(r4, MemOperand(r17, kLevelOffset));
     __ cmp(r4, r16);
     __ Check(eq, AbortReason::kUnexpectedLevelAfterReturnFromApiCall);
   }
   __ subi(r16, r16, Operand(1));
   __ stw(r16, MemOperand(r17, kLevelOffset));
-  __ LoadP(r0, MemOperand(r17, kLimitOffset));
+  __ LoadU64(r0, MemOperand(r17, kLimitOffset));
   __ cmp(r15, r0);
   __ bne(&delete_allocated_handles);
 
@@ -2907,7 +2911,7 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
   __ bind(&leave_exit_frame);
   // LeaveExitFrame expects unwind space to be in a register.
   if (stack_space_operand != nullptr) {
-    __ LoadP(r14, *stack_space_operand);
+    __ LoadU64(r14, *stack_space_operand);
   } else {
     __ mov(r14, Operand(stack_space));
   }
@@ -2916,7 +2920,7 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
   // Check if the function scheduled an exception.
   __ LoadRoot(r14, RootIndex::kTheHoleValue);
   __ Move(r15, ExternalReference::scheduled_exception_address(isolate));
-  __ LoadP(r15, MemOperand(r15));
+  __ LoadU64(r15, MemOperand(r15));
   __ cmp(r14, r15);
   __ bne(&promote_scheduled_exception);
 
@@ -3151,8 +3155,8 @@ void Builtins::Generate_CallApiGetter(MacroAssembler* masm) {
 
   __ LoadTaggedPointerField(
       scratch, FieldMemOperand(callback, AccessorInfo::kJsGetterOffset));
-  __ LoadP(api_function_address,
-        FieldMemOperand(scratch, Foreign::kForeignAddressOffset));
+  __ LoadU64(api_function_address,
+             FieldMemOperand(scratch, Foreign::kForeignAddressOffset));
 
   // +3 is to skip prolog, return address and name handle.
   MemOperand return_value_operand(
@@ -3174,13 +3178,14 @@ void Builtins::Generate_DirectCEntry(MacroAssembler* masm) {
 
   if (ABI_USES_FUNCTION_DESCRIPTORS) {
     // AIX/PPC64BE Linux use a function descriptor;
-    __ LoadP(ToRegister(ABI_TOC_REGISTER),
-             MemOperand(temp2, kSystemPointerSize));
-    __ LoadP(temp2, MemOperand(temp2, 0));  // Instruction address
+    __ LoadU64(ToRegister(ABI_TOC_REGISTER),
+               MemOperand(temp2, kSystemPointerSize));
+    __ LoadU64(temp2, MemOperand(temp2, 0));  // Instruction address
   }
 
   __ Call(temp2);  // Call the C++ function.
-  __ LoadP(r0, MemOperand(sp, kStackFrameExtraParamSlot * kSystemPointerSize));
+  __ LoadU64(r0,
+             MemOperand(sp, kStackFrameExtraParamSlot * kSystemPointerSize));
   __ mtlr(r0);
   __ blr();
 }
@@ -3230,9 +3235,6 @@ void Generate_DeoptimizationEntry(MacroAssembler* masm,
   const int kSavedRegistersAreaSize =
       (kNumberOfRegisters * kSystemPointerSize) + kDoubleRegsSize;
 
-  // Get the bailout id is passed as r29 by the caller.
-  __ mr(r5, r29);
-
   __ mov(r5, Operand(Deoptimizer::kFixedExitSizeMarker));
   // Get the address of the location in the code object (r6) (return
   // address for lazy deoptimization) and compute the fp-to-sp delta in
@@ -3246,9 +3248,10 @@ void Generate_DeoptimizationEntry(MacroAssembler* masm,
   __ PrepareCallCFunction(6, r8);
   __ li(r3, Operand::Zero());
   Label context_check;
-  __ LoadP(r4, MemOperand(fp, CommonFrameConstants::kContextOrFrameTypeOffset));
+  __ LoadU64(r4,
+             MemOperand(fp, CommonFrameConstants::kContextOrFrameTypeOffset));
   __ JumpIfSmi(r4, &context_check);
-  __ LoadP(r3, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
+  __ LoadU64(r3, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
   __ bind(&context_check);
   __ li(r4, Operand(static_cast<int>(deopt_kind)));
   // r5: bailout id already loaded.
@@ -3263,14 +3266,14 @@ void Generate_DeoptimizationEntry(MacroAssembler* masm,
 
   // Preserve "deoptimizer" object in register r3 and get the input
   // frame descriptor pointer to r4 (deoptimizer->input_);
-  __ LoadP(r4, MemOperand(r3, Deoptimizer::input_offset()));
+  __ LoadU64(r4, MemOperand(r3, Deoptimizer::input_offset()));
 
   // Copy core registers into FrameDescription::registers_[kNumRegisters].
   DCHECK_EQ(Register::kNumRegisters, kNumberOfRegisters);
   for (int i = 0; i < kNumberOfRegisters; i++) {
     int offset =
         (i * kSystemPointerSize) + FrameDescription::registers_offset();
-    __ LoadP(r5, MemOperand(sp, i * kSystemPointerSize));
+    __ LoadU64(r5, MemOperand(sp, i * kSystemPointerSize));
     __ StoreP(r5, MemOperand(r4, offset));
   }
 
@@ -3302,7 +3305,7 @@ void Generate_DeoptimizationEntry(MacroAssembler* masm,
 
   // Compute a pointer to the unwinding limit in register r5; that is
   // the first stack slot not part of the input frame.
-  __ LoadP(r5, MemOperand(r4, FrameDescription::frame_size_offset()));
+  __ LoadU64(r5, MemOperand(r4, FrameDescription::frame_size_offset()));
   __ add(r5, r5, sp);
 
   // Unwind the stack down to - but not including - the unwinding
@@ -3331,28 +3334,29 @@ void Generate_DeoptimizationEntry(MacroAssembler* masm,
   }
   __ pop(r3);  // Restore deoptimizer object (class Deoptimizer).
 
-  __ LoadP(sp, MemOperand(r3, Deoptimizer::caller_frame_top_offset()));
+  __ LoadU64(sp, MemOperand(r3, Deoptimizer::caller_frame_top_offset()));
 
   // Replace the current (input) frame with the output frames.
   Label outer_push_loop, inner_push_loop, outer_loop_header, inner_loop_header;
   // Outer loop state: r7 = current "FrameDescription** output_",
   // r4 = one past the last FrameDescription**.
   __ lwz(r4, MemOperand(r3, Deoptimizer::output_count_offset()));
-  __ LoadP(r7, MemOperand(r3, Deoptimizer::output_offset()));  // r7 is output_.
+  __ LoadU64(r7,
+             MemOperand(r3, Deoptimizer::output_offset()));  // r7 is output_.
   __ ShiftLeftImm(r4, r4, Operand(kSystemPointerSizeLog2));
   __ add(r4, r7, r4);
   __ b(&outer_loop_header);
 
   __ bind(&outer_push_loop);
   // Inner loop state: r5 = current FrameDescription*, r6 = loop index.
-  __ LoadP(r5, MemOperand(r7, 0));  // output_[ix]
-  __ LoadP(r6, MemOperand(r5, FrameDescription::frame_size_offset()));
+  __ LoadU64(r5, MemOperand(r7, 0));  // output_[ix]
+  __ LoadU64(r6, MemOperand(r5, FrameDescription::frame_size_offset()));
   __ b(&inner_loop_header);
 
   __ bind(&inner_push_loop);
   __ addi(r6, r6, Operand(-sizeof(intptr_t)));
   __ add(r9, r5, r6);
-  __ LoadP(r9, MemOperand(r9, FrameDescription::frame_content_offset()));
+  __ LoadU64(r9, MemOperand(r9, FrameDescription::frame_content_offset()));
   __ push(r9);
 
   __ bind(&inner_loop_header);
@@ -3364,7 +3368,7 @@ void Generate_DeoptimizationEntry(MacroAssembler* masm,
   __ cmp(r7, r4);
   __ blt(&outer_push_loop);
 
-  __ LoadP(r4, MemOperand(r3, Deoptimizer::input_offset()));
+  __ LoadU64(r4, MemOperand(r3, Deoptimizer::input_offset()));
   for (int i = 0; i < config->num_allocatable_double_registers(); ++i) {
     int code = config->GetAllocatableDoubleCode(i);
     const DoubleRegister dreg = DoubleRegister::from_code(code);
@@ -3373,9 +3377,9 @@ void Generate_DeoptimizationEntry(MacroAssembler* masm,
   }
 
   // Push pc, and continuation from the last output frame.
-  __ LoadP(r9, MemOperand(r5, FrameDescription::pc_offset()));
+  __ LoadU64(r9, MemOperand(r5, FrameDescription::pc_offset()));
   __ push(r9);
-  __ LoadP(r9, MemOperand(r5, FrameDescription::continuation_offset()));
+  __ LoadU64(r9, MemOperand(r5, FrameDescription::continuation_offset()));
   __ push(r9);
 
   // Restore the registers from the last output frame.
@@ -3388,7 +3392,7 @@ void Generate_DeoptimizationEntry(MacroAssembler* masm,
       int offset =
           (i * kSystemPointerSize) + FrameDescription::registers_offset();
       if ((restored_regs & (1 << i)) != 0) {
-        __ LoadP(ToRegister(i), MemOperand(scratch, offset));
+        __ LoadU64(ToRegister(i), MemOperand(scratch, offset));
       }
     }
   }
@@ -3465,11 +3469,12 @@ void Builtins::Generate_DynamicCheckMapsTrampoline(MacroAssembler* masm) {
       descriptor.GetRegisterParameter(DynamicCheckMapsDescriptor::kSlot);
   Register handler_arg =
       descriptor.GetRegisterParameter(DynamicCheckMapsDescriptor::kHandler);
-  __ LoadP(handler_arg, MemOperand(fp, CommonFrameConstants::kCallerPCOffset));
-  __ LoadP(
+  __ LoadU64(handler_arg,
+             MemOperand(fp, CommonFrameConstants::kCallerPCOffset));
+  __ LoadU64(
       slot_arg,
       MemOperand(handler_arg, Deoptimizer::kEagerWithResumeImmedArgs1PcOffset));
-  __ LoadP(
+  __ LoadU64(
       handler_arg,
       MemOperand(handler_arg, Deoptimizer::kEagerWithResumeImmedArgs2PcOffset));
 
diff --git a/chromium/v8/src/builtins/promise-abstract-operations.tq b/chromium/v8/src/builtins/promise-abstract-operations.tq
index b7a1b571e64..0e435afad9b 100644
--- a/chromium/v8/src/builtins/promise-abstract-operations.tq
+++ b/chromium/v8/src/builtins/promise-abstract-operations.tq
@@ -196,6 +196,8 @@ FulfillPromise(implicit context: Context)(
   // Assert: The value of promise.[[PromiseState]] is "pending".
   assert(promise.Status() == PromiseState::kPending);
 
+  RunContextPromiseHookResolve(promise);
+
   // 2. Let reactions be promise.[[PromiseFulfillReactions]].
   const reactions =
       UnsafeCast<(Zero | PromiseReaction)>(promise.reactions_or_result);
@@ -214,17 +216,24 @@ FulfillPromise(implicit context: Context)(
 }
 
 extern macro PromiseBuiltinsAssembler::
-    IsPromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate(): bool;
+    IsIsolatePromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate(): bool;
+
+extern macro PromiseBuiltinsAssembler::
+    IsIsolatePromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate(uint32):
+        bool;
 
 // https://tc39.es/ecma262/#sec-rejectpromise
 transitioning builtin
 RejectPromise(implicit context: Context)(
     promise: JSPromise, reason: JSAny, debugEvent: Boolean): JSAny {
+  const promiseHookFlags = PromiseHookFlags();
+
   // If promise hook is enabled or the debugger is active, let
   // the runtime handle this operation, which greatly reduces
   // the complexity here and also avoids a couple of back and
   // forth between JavaScript and C++ land.
-  if (IsPromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate() ||
+  if (IsIsolatePromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate(
+          promiseHookFlags) ||
       !promise.HasHandler()) {
     // 7. If promise.[[PromiseIsHandled]] is false, perform
     //    HostPromiseRejectionTracker(promise, "reject").
@@ -233,6 +242,8 @@ RejectPromise(implicit context: Context)(
     return runtime::RejectPromise(promise, reason, debugEvent);
   }
 
+  RunContextPromiseHookResolve(promise, promiseHookFlags);
+
   // 2. Let reactions be promise.[[PromiseRejectReactions]].
   const reactions =
       UnsafeCast<(Zero | PromiseReaction)>(promise.reactions_or_result);
diff --git a/chromium/v8/src/builtins/promise-all.tq b/chromium/v8/src/builtins/promise-all.tq
index 41dee8b9e76..5ab64a167d3 100644
--- a/chromium/v8/src/builtins/promise-all.tq
+++ b/chromium/v8/src/builtins/promise-all.tq
@@ -231,8 +231,7 @@ Reject(Object) {
       // the PromiseReaction (aka we can pass undefined to
       // PerformPromiseThen), since this is only necessary for DevTools and
       // PromiseHooks.
-      if (promiseResolveFunction != Undefined ||
-          IsPromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate() ||
+      if (promiseResolveFunction != Undefined || NeedsAnyPromiseHooks() ||
           IsPromiseSpeciesProtectorCellInvalid() || Is<Smi>(nextValue) ||
           !IsPromiseThenLookupChainIntact(
               nativeContext, UnsafeCast<HeapObject>(nextValue).map)) {
diff --git a/chromium/v8/src/builtins/promise-constructor.tq b/chromium/v8/src/builtins/promise-constructor.tq
index 3c5a5e560d4..b5f7292a77c 100644
--- a/chromium/v8/src/builtins/promise-constructor.tq
+++ b/chromium/v8/src/builtins/promise-constructor.tq
@@ -40,7 +40,8 @@ extern macro ConstructorBuiltinsAssembler::FastNewObject(
     Context, JSFunction, JSReceiver): JSObject;
 
 extern macro
-PromiseBuiltinsAssembler::IsPromiseHookEnabledOrHasAsyncEventDelegate(): bool;
+PromiseBuiltinsAssembler::IsIsolatePromiseHookEnabledOrHasAsyncEventDelegate(
+    uint32): bool;
 
 // https://tc39.es/ecma262/#sec-promise-executor
 transitioning javascript builtin
@@ -73,9 +74,7 @@ PromiseConstructor(
     result = UnsafeCast<JSPromise>(
         FastNewObject(context, promiseFun, UnsafeCast<JSReceiver>(newTarget)));
     PromiseInit(result);
-    if (IsPromiseHookEnabledOrHasAsyncEventDelegate()) {
-      runtime::PromiseHookInit(result, Undefined);
-    }
+    RunAnyPromiseHookInit(result, Undefined);
   }
 
   const isDebugActive = IsDebugActive();
diff --git a/chromium/v8/src/builtins/promise-jobs.tq b/chromium/v8/src/builtins/promise-jobs.tq
index 80e98f373b9..77d2e7cf9c4 100644
--- a/chromium/v8/src/builtins/promise-jobs.tq
+++ b/chromium/v8/src/builtins/promise-jobs.tq
@@ -7,6 +7,7 @@
 // https://tc39.es/ecma262/#sec-promise-jobs
 namespace promise {
 extern macro IsJSPromiseMap(Map): bool;
+extern macro NeedsAnyPromiseHooks(): bool;
 
 // https://tc39.es/ecma262/#sec-promiseresolvethenablejob
 transitioning builtin
@@ -25,7 +26,7 @@ PromiseResolveThenableJob(implicit context: Context)(
   const promiseThen = *NativeContextSlot(ContextSlot::PROMISE_THEN_INDEX);
   const thenableMap = thenable.map;
   if (TaggedEqual(then, promiseThen) && IsJSPromiseMap(thenableMap) &&
-      !IsPromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate() &&
+      !NeedsAnyPromiseHooks() &&
       IsPromiseSpeciesLookupChainIntact(nativeContext, thenableMap)) {
     // We know that the {thenable} is a JSPromise, which doesn't require
     // any special treatment and that {then} corresponds to the initial
diff --git a/chromium/v8/src/builtins/promise-misc.tq b/chromium/v8/src/builtins/promise-misc.tq
index 67e5e38687d..0eae717b3fc 100644
--- a/chromium/v8/src/builtins/promise-misc.tq
+++ b/chromium/v8/src/builtins/promise-misc.tq
@@ -8,6 +8,9 @@
 namespace runtime {
 extern transitioning runtime
 AllowDynamicFunction(implicit context: Context)(JSAny): JSAny;
+
+extern transitioning runtime
+ReportMessageFromMicrotask(implicit context: Context)(JSAny): JSAny;
 }
 
 // Unsafe functions that should be used very carefully.
@@ -17,6 +20,12 @@ extern macro PromiseBuiltinsAssembler::ZeroOutEmbedderOffsets(JSPromise): void;
 extern macro PromiseBuiltinsAssembler::AllocateJSPromise(Context): HeapObject;
 }
 
+extern macro
+PromiseBuiltinsAssembler::IsContextPromiseHookEnabled(uint32): bool;
+
+extern macro
+PromiseBuiltinsAssembler::PromiseHookFlags(): uint32;
+
 namespace promise {
 extern macro IsFunctionWithPrototypeSlotMap(Map): bool;
 
@@ -90,6 +99,109 @@ macro NewPromiseRejectReactionJobTask(implicit context: Context)(
   };
 }
 
+@export
+transitioning macro RunContextPromiseHookInit(implicit context: Context)(
+    promise: JSPromise, parent: Object) {
+  const maybeHook = *NativeContextSlot(
+      ContextSlot::PROMISE_HOOK_INIT_FUNCTION_INDEX);
+  const hook = Cast<Callable>(maybeHook) otherwise return;
+  const parentObject = Is<JSPromise>(parent) ? Cast<JSPromise>(parent)
+      otherwise unreachable: Undefined;
+
+  try {
+    Call(context, hook, Undefined, promise, parentObject);
+  } catch (e) {
+    runtime::ReportMessageFromMicrotask(e);
+  }
+}
+
+@export
+transitioning macro RunContextPromiseHookResolve(implicit context: Context)(
+    promise: JSPromise) {
+  RunContextPromiseHook(
+      ContextSlot::PROMISE_HOOK_RESOLVE_FUNCTION_INDEX, promise,
+      PromiseHookFlags());
+}
+
+@export
+transitioning macro RunContextPromiseHookResolve(implicit context: Context)(
+    promise: JSPromise, flags: uint32) {
+  RunContextPromiseHook(
+      ContextSlot::PROMISE_HOOK_RESOLVE_FUNCTION_INDEX, promise, flags);
+}
+
+@export
+transitioning macro RunContextPromiseHookBefore(implicit context: Context)(
+    promiseOrCapability: JSPromise|PromiseCapability|Undefined) {
+  RunContextPromiseHook(
+      ContextSlot::PROMISE_HOOK_BEFORE_FUNCTION_INDEX, promiseOrCapability,
+      PromiseHookFlags());
+}
+
+@export
+transitioning macro RunContextPromiseHookBefore(implicit context: Context)(
+    promiseOrCapability: JSPromise|PromiseCapability|Undefined, flags: uint32) {
+  RunContextPromiseHook(
+      ContextSlot::PROMISE_HOOK_BEFORE_FUNCTION_INDEX, promiseOrCapability,
+      flags);
+}
+
+@export
+transitioning macro RunContextPromiseHookAfter(implicit context: Context)(
+    promiseOrCapability: JSPromise|PromiseCapability|Undefined) {
+  RunContextPromiseHook(
+      ContextSlot::PROMISE_HOOK_AFTER_FUNCTION_INDEX, promiseOrCapability,
+      PromiseHookFlags());
+}
+
+@export
+transitioning macro RunContextPromiseHookAfter(implicit context: Context)(
+    promiseOrCapability: JSPromise|PromiseCapability|Undefined, flags: uint32) {
+  RunContextPromiseHook(
+      ContextSlot::PROMISE_HOOK_AFTER_FUNCTION_INDEX, promiseOrCapability,
+      flags);
+}
+
+transitioning macro RunContextPromiseHook(implicit context: Context)(
+    slot: Slot<NativeContext, Undefined|Callable>,
+    promiseOrCapability: JSPromise|PromiseCapability|Undefined, flags: uint32) {
+  if (!IsContextPromiseHookEnabled(flags)) return;
+  const maybeHook = *NativeContextSlot(slot);
+  const hook = Cast<Callable>(maybeHook) otherwise return;
+
+  let promise: JSPromise;
+  typeswitch (promiseOrCapability) {
+    case (jspromise: JSPromise): {
+      promise = jspromise;
+    }
+    case (capability: PromiseCapability): {
+      promise = Cast<JSPromise>(capability.promise) otherwise return;
+    }
+    case (Undefined): {
+      return;
+    }
+  }
+
+  try {
+    Call(context, hook, Undefined, promise);
+  } catch (e) {
+    runtime::ReportMessageFromMicrotask(e);
+  }
+}
+
+transitioning macro RunAnyPromiseHookInit(implicit context: Context)(
+    promise: JSPromise, parent: Object) {
+  const promiseHookFlags = PromiseHookFlags();
+  // Fast return if no hooks are set.
+  if (promiseHookFlags == 0) return;
+  if (IsContextPromiseHookEnabled(promiseHookFlags)) {
+    RunContextPromiseHookInit(promise, parent);
+  }
+  if (IsIsolatePromiseHookEnabledOrHasAsyncEventDelegate(promiseHookFlags)) {
+    runtime::PromiseHookInit(promise, parent);
+  }
+}
+
 // These allocate and initialize a promise with pending state and
 // undefined fields.
 //
@@ -100,9 +212,7 @@ transitioning macro NewJSPromise(implicit context: Context)(parent: Object):
     JSPromise {
   const instance = InnerNewJSPromise();
   PromiseInit(instance);
-  if (IsPromiseHookEnabledOrHasAsyncEventDelegate()) {
-    runtime::PromiseHookInit(instance, parent);
-  }
+  RunAnyPromiseHookInit(instance, parent);
   return instance;
 }
 
@@ -124,10 +234,7 @@ transitioning macro NewJSPromise(implicit context: Context)(
   instance.reactions_or_result = result;
   instance.SetStatus(status);
   promise_internal::ZeroOutEmbedderOffsets(instance);
-
-  if (IsPromiseHookEnabledOrHasAsyncEventDelegate()) {
-    runtime::PromiseHookInit(instance, Undefined);
-  }
+  RunAnyPromiseHookInit(instance, Undefined);
   return instance;
 }
 
diff --git a/chromium/v8/src/builtins/promise-resolve.tq b/chromium/v8/src/builtins/promise-resolve.tq
index e933dfbae0a..fa3d19411fc 100644
--- a/chromium/v8/src/builtins/promise-resolve.tq
+++ b/chromium/v8/src/builtins/promise-resolve.tq
@@ -30,7 +30,8 @@ transitioning builtin
 PromiseResolve(implicit context: Context)(
     constructor: JSReceiver, value: JSAny): JSAny {
   const nativeContext = LoadNativeContext(context);
-  const promiseFun = *NativeContextSlot(ContextSlot::PROMISE_FUNCTION_INDEX);
+  const promiseFun = *NativeContextSlot(
+      nativeContext, ContextSlot::PROMISE_FUNCTION_INDEX);
   try {
     // Check if {value} is a JSPromise.
     const value = Cast<JSPromise>(value) otherwise NeedToAllocate;
@@ -40,7 +41,8 @@ PromiseResolve(implicit context: Context)(
     // intact, as that guards the lookup path for "constructor" on
     // JSPromise instances which have the (initial) Promise.prototype.
     const promisePrototype =
-        *NativeContextSlot(ContextSlot::PROMISE_PROTOTYPE_INDEX);
+        *NativeContextSlot(
+        nativeContext, ContextSlot::PROMISE_PROTOTYPE_INDEX);
     // Check that Torque load elimination works.
     static_assert(nativeContext == LoadNativeContext(context));
     if (value.map.prototype != promisePrototype) {
@@ -97,7 +99,7 @@ ResolvePromise(implicit context: Context)(
   // We also let the runtime handle it if promise == resolution.
   // We can use pointer comparison here, since the {promise} is guaranteed
   // to be a JSPromise inside this function and thus is reference comparable.
-  if (IsPromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate() ||
+  if (IsIsolatePromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate() ||
       TaggedEqual(promise, resolution))
     deferred {
       return runtime::ResolvePromise(promise, resolution);
@@ -139,7 +141,8 @@ ResolvePromise(implicit context: Context)(
       assert(IsJSReceiverMap(resolutionMap));
       assert(!IsPromiseThenProtectorCellInvalid());
       if (resolutionMap ==
-          *NativeContextSlot(ContextSlot::ITERATOR_RESULT_MAP_INDEX)) {
+          *NativeContextSlot(
+              nativeContext, ContextSlot::ITERATOR_RESULT_MAP_INDEX)) {
         return FulfillPromise(promise, resolution);
       } else {
         goto Slow;
@@ -147,10 +150,11 @@ ResolvePromise(implicit context: Context)(
     }
 
     const promisePrototype =
-        *NativeContextSlot(ContextSlot::PROMISE_PROTOTYPE_INDEX);
+        *NativeContextSlot(
+        nativeContext, ContextSlot::PROMISE_PROTOTYPE_INDEX);
     if (resolutionMap.prototype == promisePrototype) {
       // The {resolution} is a native Promise in this case.
-      then = *NativeContextSlot(ContextSlot::PROMISE_THEN_INDEX);
+      then = *NativeContextSlot(nativeContext, ContextSlot::PROMISE_THEN_INDEX);
       // Check that Torque load elimination works.
       static_assert(nativeContext == LoadNativeContext(context));
       goto Enqueue;
diff --git a/chromium/v8/src/builtins/riscv64/builtins-riscv64.cc b/chromium/v8/src/builtins/riscv64/builtins-riscv64.cc
index 04907f5268a..afd9a1fca1c 100644
--- a/chromium/v8/src/builtins/riscv64/builtins-riscv64.cc
+++ b/chromium/v8/src/builtins/riscv64/builtins-riscv64.cc
@@ -6,6 +6,7 @@
 
 #include "src/api/api-arguments.h"
 #include "src/codegen/code-factory.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer/deoptimizer.h"
 #include "src/execution/frame-constants.h"
@@ -100,7 +101,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     // a0: number of arguments (untagged)
     // a1: constructor function
     // a3: new target
-    __ InvokeFunctionWithNewTarget(a1, a3, a0, CALL_FUNCTION);
+    __ InvokeFunctionWithNewTarget(a1, a3, a0, InvokeType::kCall);
 
     // Restore context from the frame.
     __ Ld(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
@@ -225,7 +226,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
   __ Push(a6);
 
   // Call the function.
-  __ InvokeFunctionWithNewTarget(a1, a3, a0, CALL_FUNCTION);
+  __ InvokeFunctionWithNewTarget(a1, a3, a0, InvokeType::kCall);
 
   // ----------- S t a t e -------------
   //  --                 a0: constructor result
@@ -300,12 +301,16 @@ void Builtins::Generate_JSBuiltinsConstructStub(MacroAssembler* masm) {
   Generate_JSBuiltinsConstructStubHelper(masm);
 }
 
-static void GetSharedFunctionInfoBytecode(MacroAssembler* masm,
-                                          Register sfi_data,
-                                          Register scratch1) {
+// TODO(v8:11429): Add a path for "not_compiled" and unify the two uses under
+// the more general dispatch.
+static void GetSharedFunctionInfoBytecodeOrBaseline(MacroAssembler* masm,
+                                                    Register sfi_data,
+                                                    Register scratch1,
+                                                    Label* is_baseline) {
   Label done;
 
   __ GetObjectType(sfi_data, scratch1, scratch1);
+  __ Branch(is_baseline, eq, scratch1, Operand(BASELINE_DATA_TYPE));
   __ Branch(&done, ne, scratch1, Operand(INTERPRETER_DATA_TYPE));
   __ Ld(sfi_data,
         FieldMemOperand(sfi_data, InterpreterData::kBytecodeArrayOffset));
@@ -325,7 +330,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Store input value into generator object.
   __ Sd(a0, FieldMemOperand(a1, JSGeneratorObject::kInputOrDebugPosOffset));
   __ RecordWriteField(a1, JSGeneratorObject::kInputOrDebugPosOffset, a0, a3,
-                      kRAHasNotBeenSaved, kDontSaveFPRegs);
+                      kRAHasNotBeenSaved, SaveFPRegsMode::kIgnore);
 
   // Load suspended function and context.
   __ Ld(a4, FieldMemOperand(a1, JSGeneratorObject::kFunctionOffset));
@@ -388,12 +393,14 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
 
   // Underlying function needs to have bytecode available.
   if (FLAG_debug_code) {
+    Label is_baseline;
     __ Ld(a3, FieldMemOperand(a4, JSFunction::kSharedFunctionInfoOffset));
     __ Ld(a3, FieldMemOperand(a3, SharedFunctionInfo::kFunctionDataOffset));
-    GetSharedFunctionInfoBytecode(masm, a3, a0);
+    GetSharedFunctionInfoBytecodeOrBaseline(masm, a3, a0, &is_baseline);
     __ GetObjectType(a3, a3, a3);
     __ Assert(eq, AbortReason::kMissingBytecodeArray, a3,
               Operand(BYTECODE_ARRAY_TYPE));
+    __ bind(&is_baseline);
   }
 
   // Resume (Ignition/TurboFan) generator object.
@@ -763,8 +770,8 @@ static void ReplaceClosureCodeWithOptimizedCode(MacroAssembler* masm,
   __ Sd(optimized_code, FieldMemOperand(closure, JSFunction::kCodeOffset));
   __ Move(scratch1, optimized_code);  // Write barrier clobbers scratch1 below.
   __ RecordWriteField(closure, JSFunction::kCodeOffset, scratch1, scratch2,
-                      kRAHasNotBeenSaved, kDontSaveFPRegs, OMIT_REMEMBERED_SET,
-                      OMIT_SMI_CHECK);
+                      kRAHasNotBeenSaved, SaveFPRegsMode::kIgnore,
+                      RememberedSetAction::kOmit, SmiCheck::kOmit);
 }
 
 static void LeaveInterpreterFrame(MacroAssembler* masm, Register scratch1,
@@ -964,6 +971,184 @@ static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
   __ bind(&end);
 }
 
+// Read off the optimization state in the feedback vector and check if there
+// is optimized code or a optimization marker that needs to be processed.
+static void LoadOptimizationStateAndJumpIfNeedsProcessing(
+    MacroAssembler* masm, Register optimization_state, Register feedback_vector,
+    Label* has_optimized_code_or_marker) {
+  __ RecordComment("[ Check optimization state");
+  UseScratchRegisterScope temps(masm);
+  Register scratch = temps.Acquire();
+  __ Lw(optimization_state,
+        FieldMemOperand(feedback_vector, FeedbackVector::kFlagsOffset));
+  __ And(
+      scratch, optimization_state,
+      Operand(FeedbackVector::kHasOptimizedCodeOrCompileOptimizedMarkerMask));
+  __ Branch(has_optimized_code_or_marker, ne, scratch, Operand(zero_reg));
+  __ RecordComment("]");
+}
+
+static void MaybeOptimizeCodeOrTailCallOptimizedCodeSlot(
+    MacroAssembler* masm, Register optimization_state,
+    Register feedback_vector) {
+  Label maybe_has_optimized_code;
+  // Check if optimized code marker is available
+  __ And(
+      t0, optimization_state,
+      Operand(FeedbackVector::kHasCompileOptimizedOrLogFirstExecutionMarker));
+  __ Branch(&maybe_has_optimized_code, eq, t0, Operand(zero_reg));
+
+  Register optimization_marker = optimization_state;
+  __ DecodeField<FeedbackVector::OptimizationMarkerBits>(optimization_marker);
+  MaybeOptimizeCode(masm, feedback_vector, optimization_marker);
+
+  __ bind(&maybe_has_optimized_code);
+  Register optimized_code_entry = optimization_state;
+  __ Ld(optimization_marker,
+        FieldMemOperand(feedback_vector,
+                        FeedbackVector::kMaybeOptimizedCodeOffset));
+  TailCallOptimizedCodeSlot(masm, optimized_code_entry, t4, a5);
+}
+
+// static
+void Builtins::Generate_BaselineOutOfLinePrologue(MacroAssembler* masm) {
+  UseScratchRegisterScope temps(masm);
+  temps.Include(kScratchReg.bit() | kScratchReg2.bit());
+  auto descriptor = Builtins::CallInterfaceDescriptorFor(
+      Builtins::kBaselineOutOfLinePrologue);
+  Register closure = descriptor.GetRegisterParameter(
+      BaselineOutOfLinePrologueDescriptor::kClosure);
+  // Load the feedback vector from the closure.
+  Register feedback_vector = temps.Acquire();
+  __ Ld(feedback_vector,
+        FieldMemOperand(closure, JSFunction::kFeedbackCellOffset));
+  __ Ld(feedback_vector, FieldMemOperand(feedback_vector, Cell::kValueOffset));
+  if (FLAG_debug_code) {
+    __ GetObjectType(feedback_vector, t0, t0);
+    __ Assert(eq, AbortReason::kExpectedFeedbackVector, t0,
+              Operand(FEEDBACK_VECTOR_TYPE));
+  }
+
+  // Check for an optimization marker.
+  Label has_optimized_code_or_marker;
+  Register optimization_state = temps.Acquire();
+  LoadOptimizationStateAndJumpIfNeedsProcessing(
+      masm, optimization_state, feedback_vector, &has_optimized_code_or_marker);
+
+  // Increment invocation count for the function.
+  {
+    Register invocation_count = t0;
+    __ Lw(invocation_count,
+          FieldMemOperand(feedback_vector,
+                          FeedbackVector::kInvocationCountOffset));
+    __ Add32(invocation_count, invocation_count, Operand(1));
+    __ Sw(invocation_count,
+          FieldMemOperand(feedback_vector,
+                          FeedbackVector::kInvocationCountOffset));
+  }
+
+  __ RecordComment("[ Frame Setup");
+  FrameScope frame_scope(masm, StackFrame::MANUAL);
+  // Normally the first thing we'd do here is Push(lr, fp), but we already
+  // entered the frame in BaselineCompiler::Prologue, as we had to use the
+  // value lr before the call to this BaselineOutOfLinePrologue builtin.
+
+  Register callee_context = descriptor.GetRegisterParameter(
+      BaselineOutOfLinePrologueDescriptor::kCalleeContext);
+  Register callee_js_function = descriptor.GetRegisterParameter(
+      BaselineOutOfLinePrologueDescriptor::kClosure);
+  __ Push(callee_context, callee_js_function);
+  DCHECK_EQ(callee_js_function, kJavaScriptCallTargetRegister);
+  DCHECK_EQ(callee_js_function, kJSFunctionRegister);
+
+  Register argc = descriptor.GetRegisterParameter(
+      BaselineOutOfLinePrologueDescriptor::kJavaScriptCallArgCount);
+  // We'll use the bytecode for both code age/OSR resetting, and pushing onto
+  // the frame, so load it into a register.
+  Register bytecodeArray = descriptor.GetRegisterParameter(
+      BaselineOutOfLinePrologueDescriptor::kInterpreterBytecodeArray);
+
+  // Reset code age and the OSR arming. The OSR field and BytecodeAgeOffset
+  // are 8-bit fields next to each other, so we could just optimize by writing
+  // a 16-bit. These static asserts guard our assumption is valid.
+  STATIC_ASSERT(BytecodeArray::kBytecodeAgeOffset ==
+                BytecodeArray::kOsrNestingLevelOffset + kCharSize);
+  STATIC_ASSERT(BytecodeArray::kNoAgeBytecodeAge == 0);
+  __ Sh(zero_reg,
+        FieldMemOperand(bytecodeArray, BytecodeArray::kOsrNestingLevelOffset));
+
+  __ Push(argc, bytecodeArray);
+
+  // Baseline code frames store the feedback vector where interpreter would
+  // store the bytecode offset.
+  if (FLAG_debug_code) {
+    __ GetObjectType(feedback_vector, t0, t0);
+    __ Assert(eq, AbortReason::kExpectedFeedbackVector, t0,
+              Operand(FEEDBACK_VECTOR_TYPE));
+  }
+  // Our stack is currently aligned. We have have to push something along with
+  // the feedback vector to keep it that way -- we may as well start
+  // initialising the register frame.
+  // TODO(v8:11429,leszeks): Consider guaranteeing that this call leaves
+  // `undefined` in the accumulator register, to skip the load in the baseline
+  // code.
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
+  __ Push(feedback_vector, kInterpreterAccumulatorRegister);
+  __ RecordComment("]");
+
+  __ RecordComment("[ Stack/interrupt check");
+  Label call_stack_guard;
+  {
+    // Stack check. This folds the checks for both the interrupt stack limit
+    // check and the real stack limit into one by just checking for the
+    // interrupt limit. The interrupt limit is either equal to the real stack
+    // limit or tighter. By ensuring we have space until that limit after
+    // building the frame we can quickly precheck both at once.
+    Register frame_size = t0;
+    __ Ld(frame_size,
+          FieldMemOperand(bytecodeArray, BytecodeArray::kFrameSizeOffset));
+    Register sp_minus_frame_size = frame_size;
+    __ Sub64(sp_minus_frame_size, sp, frame_size);
+    Register interrupt_limit = t1;
+    __ LoadStackLimit(interrupt_limit,
+                      MacroAssembler::StackLimitKind::kInterruptStackLimit);
+    __ Branch(&call_stack_guard, Uless, sp_minus_frame_size,
+              Operand(interrupt_limit));
+    __ RecordComment("]");
+  }
+
+  // Do "fast" return to the caller pc in lr.
+  // TODO(v8:11429): Document this frame setup better.
+  __ Ret();
+
+  __ bind(&has_optimized_code_or_marker);
+  {
+    __ RecordComment("[ Optimized marker check");
+    // Drop the frame created by the baseline call.
+    __ Pop(fp, ra);
+    MaybeOptimizeCodeOrTailCallOptimizedCodeSlot(masm, optimization_state,
+                                                 feedback_vector);
+    __ Trap();
+    __ RecordComment("]");
+  }
+
+  __ bind(&call_stack_guard);
+  {
+    Register new_target = descriptor.GetRegisterParameter(
+        BaselineOutOfLinePrologueDescriptor::kJavaScriptCallNewTarget);
+
+    FrameScope frame_scope(masm, StackFrame::INTERNAL);
+    __ RecordComment("[ Stack/interrupt call");
+    // Save incoming new target or generator
+    __ Push(zero_reg, new_target);
+    __ CallRuntime(Runtime::kStackGuard);
+    __ Pop(new_target, zero_reg);
+    __ RecordComment("]");
+  }
+  __ Ret();
+  temps.Exclude(kScratchReg.bit() | kScratchReg2.bit());
+}
+
 // Generate code for entering a JS function with the interpreter.
 // On entry to the function the receiver and arguments have been pushed on the
 // stack left to right.
@@ -989,8 +1174,9 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
         FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
   __ Ld(kInterpreterBytecodeArrayRegister,
         FieldMemOperand(kScratchReg, SharedFunctionInfo::kFunctionDataOffset));
-  GetSharedFunctionInfoBytecode(masm, kInterpreterBytecodeArrayRegister,
-                                kScratchReg);
+  Label is_baseline;
+  GetSharedFunctionInfoBytecodeOrBaseline(
+      masm, kInterpreterBytecodeArrayRegister, kScratchReg, &is_baseline);
 
   // The bytecode array could have been flushed from the shared function info,
   // if so, call into CompileLazy.
@@ -1188,6 +1374,44 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
                         FeedbackVector::kMaybeOptimizedCodeOffset));
 
   TailCallOptimizedCodeSlot(masm, optimized_code_entry, t4, a5);
+  __ bind(&is_baseline);
+  {
+    // Load the feedback vector from the closure.
+    __ Ld(feedback_vector,
+          FieldMemOperand(closure, JSFunction::kFeedbackCellOffset));
+    __ Ld(feedback_vector,
+          FieldMemOperand(feedback_vector, Cell::kValueOffset));
+
+    Label install_baseline_code;
+    // Check if feedback vector is valid. If not, call prepare for baseline to
+    // allocate it.
+    __ Ld(t0, FieldMemOperand(feedback_vector, HeapObject::kMapOffset));
+    __ Lh(t0, FieldMemOperand(t0, Map::kInstanceTypeOffset));
+    __ Branch(&install_baseline_code, ne, t0, Operand(FEEDBACK_VECTOR_TYPE));
+
+    // Read off the optimization state in the feedback vector.
+    // TODO(v8:11429): Is this worth doing here? Baseline code will check it
+    // anyway...
+    __ Ld(optimization_state,
+          FieldMemOperand(feedback_vector, FeedbackVector::kFlagsOffset));
+
+    // Check if there is optimized code or a optimization marker that needes to
+    // be processed.
+    __ And(
+        t0, optimization_state,
+        Operand(FeedbackVector::kHasOptimizedCodeOrCompileOptimizedMarkerMask));
+    __ Branch(&has_optimized_code_or_marker, ne, t0, Operand(zero_reg));
+
+    // Load the baseline code into the closure.
+    __ Ld(a2, FieldMemOperand(kInterpreterBytecodeArrayRegister,
+                              BaselineData::kBaselineCodeOffset));
+    static_assert(kJavaScriptCallCodeStartRegister == a2, "ABI mismatch");
+    ReplaceClosureCodeWithOptimizedCode(masm, a2, closure, t0, t1);
+    __ JumpCodeObject(a2);
+
+    __ bind(&install_baseline_code);
+    GenerateTailCallToReturnedCode(masm, Runtime::kInstallBaselineCode);
+  }
 
   __ bind(&compile_lazy);
   GenerateTailCallToReturnedCode(masm, Runtime::kCompileLazy);
@@ -1407,7 +1631,7 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   __ Jump(kJavaScriptCallCodeStartRegister);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtNextBytecode(MacroAssembler* masm) {
   // Advance the current bytecode offset stored within the given interpreter
   // stack frame. This simulates what all bytecode handlers do upon completion
   // of the underlying operation.
@@ -1454,7 +1678,7 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
   __ Abort(AbortReason::kInvalidBytecodeAdvance);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeDispatch(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtBytecode(MacroAssembler* masm) {
   Generate_InterpreterEnterBytecode(masm);
 }
 
@@ -1503,12 +1727,12 @@ void Generate_ContinueToBuiltinHelper(MacroAssembler* masm,
                 sp, BuiltinContinuationFrameConstants::kFixedFrameSizeFromFp));
   // Load builtin index (stored as a Smi) and use it to get the builtin start
   // address from the builtins table.
-  __ Pop(t0);
+  __ Pop(t6);
   __ Add64(sp, sp,
            Operand(BuiltinContinuationFrameConstants::kFixedFrameSizeFromFp));
   __ Pop(ra);
-  __ LoadEntryFromBuiltinIndex(t0);
-  __ Jump(t0);
+  __ LoadEntryFromBuiltinIndex(t6);
+  __ Jump(t6);
 }
 }  // namespace
 
@@ -1542,7 +1766,20 @@ void Builtins::Generate_NotifyDeoptimized(MacroAssembler* masm) {
   __ Ret();
 }
 
-void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
+void Builtins::Generate_TailCallOptimizedCodeSlot(MacroAssembler* masm) {
+  Register optimized_code_entry = kJavaScriptCallCodeStartRegister;
+  TailCallOptimizedCodeSlot(masm, optimized_code_entry, t4, t0);
+}
+namespace {
+
+void Generate_OSREntry(MacroAssembler* masm, Register entry_address,
+                       Operand offset = Operand(int64_t(0))) {
+  __ Add64(ra, entry_address, offset);
+  // And "return" to the OSR entry point of the function.
+  __ Ret();
+}
+
+void OnStackReplacement(MacroAssembler* masm, bool is_interpreter) {
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
     __ CallRuntime(Runtime::kCompileForOnStackReplacement);
@@ -1550,11 +1787,11 @@ void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
 
   // If the code object is null, just return to the caller.
   __ Ret(eq, a0, Operand(Smi::zero()));
-
-  // Drop the handler frame that is be sitting on top of the actual
-  // JavaScript frame. This is the case then OSR is triggered from bytecode.
-  __ LeaveFrame(StackFrame::STUB);
-
+  if (is_interpreter) {
+    // Drop the handler frame that is be sitting on top of the actual
+    // JavaScript frame. This is the case then OSR is triggered from bytecode.
+    __ LeaveFrame(StackFrame::STUB);
+  }
   // Load deoptimization data from the code object.
   // <deopt_data> = <code>[#deoptimization_data_offset]
   __ Ld(a1, MemOperand(a0, Code::kDeoptimizationDataOffset - kHeapObjectTag));
@@ -1568,9 +1805,18 @@ void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
   // Compute the target address = code_obj + header_size + osr_offset
   // <entry_addr> = <code_obj> + #header_size + <osr_offset>
   __ Add64(a0, a0, a1);
-  __ Add64(ra, a0, Code::kHeaderSize - kHeapObjectTag);
-  // And "return" to the OSR entry point of the function.
-  __ Ret();
+  Generate_OSREntry(masm, a0, Operand(Code::kHeaderSize - kHeapObjectTag));
+}
+}  // namespace
+
+void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
+  return OnStackReplacement(masm, true);
+}
+
+void Builtins::Generate_BaselineOnStackReplacement(MacroAssembler* masm) {
+  __ Ld(kContextRegister,
+        MemOperand(fp, StandardFrameConstants::kContextOffset));
+  return OnStackReplacement(masm, false);
 }
 
 // static
@@ -1808,7 +2054,7 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
   //  -- a4 : len (number of elements to push from args)
   //  -- a3 : new.target (for [[Construct]])
   // -----------------------------------
-  if (masm->emit_debug_code()) {
+  if (FLAG_debug_code) {
     // Allow a2 to be a FixedArray, or a FixedDoubleArray if a4 == 0.
     Label ok, fail;
     __ AssertNotSmi(a2);
@@ -2070,7 +2316,7 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
 
   __ Lhu(a2,
          FieldMemOperand(a2, SharedFunctionInfo::kFormalParameterCountOffset));
-  __ InvokeFunctionCode(a1, no_reg, a2, a0, JUMP_FUNCTION);
+  __ InvokeFunctionCode(a1, no_reg, a2, a0, InvokeType::kJump);
 
   // The function is a "classConstructor", need to raise an exception.
   __ bind(&class_constructor);
@@ -2438,10 +2684,10 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // sp: stack pointer    (restored as callee's sp after C call)
   // cp: current context  (C callee-saved)
   //
-  // If argv_mode == kArgvInRegister:
+  // If argv_mode == ArgvMode::kRegister:
   // a2: pointer to the first argument
 
-  if (argv_mode == kArgvInRegister) {
+  if (argv_mode == ArgvMode::kRegister) {
     // Move argv into the correct register.
     __ Move(s1, a2);
   } else {
@@ -2453,7 +2699,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // Enter the exit frame that transitions from JavaScript to C++.
   FrameScope scope(masm, StackFrame::MANUAL);
   __ EnterExitFrame(
-      save_doubles == kSaveFPRegs, 0,
+      save_doubles == SaveFPRegsMode::kSave, 0,
       builtin_exit_frame ? StackFrame::BUILTIN_EXIT : StackFrame::EXIT);
 
   // s3: number of arguments  including receiver (C callee-saved)
@@ -2502,12 +2748,12 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // a0:a1: result
   // sp: stack pointer
   // fp: frame pointer
-  Register argc = argv_mode == kArgvInRegister
+  Register argc = argv_mode == ArgvMode::kRegister
                       // We don't want to pop arguments so set argc to no_reg.
                       ? no_reg
                       // s3: still holds argc (callee-saved).
                       : s3;
-  __ LeaveExitFrame(save_doubles == kSaveFPRegs, argc, EMIT_RETURN);
+  __ LeaveExitFrame(save_doubles == SaveFPRegsMode::kSave, argc, EMIT_RETURN);
 
   // Handling of exception.
   __ bind(&exception_returned);
@@ -2689,6 +2935,10 @@ void Builtins::Generate_GenericJSToWasmWrapper(MacroAssembler* masm) {
   __ Trap();
 }
 
+void Builtins::Generate_WasmOnStackReplace(MacroAssembler* masm) {
+  // Only needed on x64.
+  __ Trap();
+}
 namespace {
 
 int AddressOffset(ExternalReference ref0, ExternalReference ref1) {
@@ -2762,7 +3012,7 @@ void CallApiFunctionAndReturn(MacroAssembler* masm, Register function_address,
   // No more valid handles (the result handle was the last one). Restore
   // previous handle scope.
   __ Sd(s3, MemOperand(s5, kNextOffset));
-  if (__ emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ Lw(a1, MemOperand(s5, kLevelOffset));
     __ Check(eq, AbortReason::kUnexpectedLevelAfterReturnFromApiCall, a1,
              Operand(s2));
@@ -3228,9 +3478,9 @@ void Generate_DeoptimizationEntry(MacroAssembler* masm,
     }
   }
 
-  __ pop(t3);  // Get continuation, leave pc on stack.
+  __ pop(t6);  // Get continuation, leave pc on stack.
   __ pop(ra);
-  __ Jump(t3);
+  __ Jump(t6);
   __ stop();
 }
 
@@ -3252,6 +3502,146 @@ void Builtins::Generate_DeoptimizationEntry_Lazy(MacroAssembler* masm) {
   Generate_DeoptimizationEntry(masm, DeoptimizeKind::kLazy);
 }
 
+namespace {
+
+// Converts an interpreter frame into a baseline frame and continues execution
+// in baseline code (baseline code has to exist on the shared function info),
+// either at the start or the end of the current bytecode.
+void Generate_BaselineEntry(MacroAssembler* masm, bool next_bytecode,
+                            bool is_osr = false) {
+  __ Push(zero_reg, kInterpreterAccumulatorRegister);
+  Label start;
+  __ bind(&start);
+
+  // Get function from the frame.
+  Register closure = a1;
+  __ Ld(closure, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
+
+  // Replace BytecodeOffset with the feedback vector.
+  Register feedback_vector = a2;
+  __ Ld(feedback_vector,
+        FieldMemOperand(closure, JSFunction::kFeedbackCellOffset));
+  __ Ld(feedback_vector, FieldMemOperand(feedback_vector, Cell::kValueOffset));
+  Label install_baseline_code;
+  // Check if feedback vector is valid. If not, call prepare for baseline to
+  // allocate it.
+  __ GetObjectType(feedback_vector, t0, t0);
+  __ Branch(&install_baseline_code, eq, t0, Operand(FEEDBACK_VECTOR_TYPE));
+  // Save BytecodeOffset from the stack frame.
+  __ SmiUntag(kInterpreterBytecodeOffsetRegister,
+              MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
+  // Replace BytecodeOffset with the feedback vector.
+  __ Sd(feedback_vector,
+        MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
+  feedback_vector = no_reg;
+
+  // Get the Code object from the shared function info.
+  UseScratchRegisterScope temps(masm);
+  Register code_obj = temps.Acquire();
+  __ Ld(code_obj,
+        FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
+  __ Ld(code_obj,
+        FieldMemOperand(code_obj, SharedFunctionInfo::kFunctionDataOffset));
+  __ Ld(code_obj, FieldMemOperand(code_obj, BaselineData::kBaselineCodeOffset));
+
+  // Compute baseline pc for bytecode offset.
+  __ Push(zero_reg, kInterpreterAccumulatorRegister);
+  ExternalReference get_baseline_pc_extref;
+  if (next_bytecode || is_osr) {
+    get_baseline_pc_extref =
+        ExternalReference::baseline_pc_for_next_executed_bytecode();
+  } else {
+    get_baseline_pc_extref =
+        ExternalReference::baseline_pc_for_bytecode_offset();
+  }
+
+  Register get_baseline_pc = a3;
+  __ li(get_baseline_pc, get_baseline_pc_extref);
+
+  // If the code deoptimizes during the implicit function entry stack interrupt
+  // check, it will have a bailout ID of kFunctionEntryBytecodeOffset, which is
+  // not a valid bytecode offset.
+  // TODO(pthier): Investigate if it is feasible to handle this special case
+  // in TurboFan instead of here.
+  Label valid_bytecode_offset, function_entry_bytecode;
+  if (!is_osr) {
+    __ Branch(&function_entry_bytecode, eq, kInterpreterBytecodeOffsetRegister,
+              Operand(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                      kFunctionEntryBytecodeOffset));
+  }
+
+  __ Sub64(kInterpreterBytecodeOffsetRegister,
+           kInterpreterBytecodeOffsetRegister,
+           (BytecodeArray::kHeaderSize - kHeapObjectTag));
+
+  __ bind(&valid_bytecode_offset);
+  // Get bytecode array from the stack frame.
+  __ Ld(kInterpreterBytecodeArrayRegister,
+        MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
+  {
+    Register arg_reg_1 = a0;
+    Register arg_reg_2 = a1;
+    Register arg_reg_3 = a2;
+    __ Move(arg_reg_1, code_obj);
+    __ Move(arg_reg_2, kInterpreterBytecodeOffsetRegister);
+    __ Move(arg_reg_3, kInterpreterBytecodeArrayRegister);
+    FrameScope scope(masm, StackFrame::INTERNAL);
+    __ CallCFunction(get_baseline_pc, 3, 0);
+  }
+  __ Add64(code_obj, code_obj, kReturnRegister0);
+  __ Pop(kInterpreterAccumulatorRegister, zero_reg);
+
+  if (is_osr) {
+    // Reset the OSR loop nesting depth to disarm back edges.
+    // TODO(pthier): Separate baseline Sparkplug from TF arming and don't disarm
+    // Sparkplug here.
+    __ Sd(zero_reg, FieldMemOperand(kInterpreterBytecodeArrayRegister,
+                                    BytecodeArray::kOsrNestingLevelOffset));
+    Generate_OSREntry(masm, code_obj,
+                      Operand(Code::kHeaderSize - kHeapObjectTag));
+  } else {
+    __ Add64(code_obj, code_obj, Code::kHeaderSize - kHeapObjectTag);
+    __ Jump(code_obj);
+  }
+  __ Trap();  // Unreachable.
+
+  if (!is_osr) {
+    __ bind(&function_entry_bytecode);
+    // If the bytecode offset is kFunctionEntryOffset, get the start address of
+    // the first bytecode.
+    __ li(kInterpreterBytecodeOffsetRegister, Operand(int64_t(0)));
+    if (next_bytecode) {
+      __ li(get_baseline_pc,
+            ExternalReference::baseline_pc_for_bytecode_offset());
+    }
+    __ Branch(&valid_bytecode_offset);
+  }
+
+  __ bind(&install_baseline_code);
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
+    __ Push(closure);
+    __ CallRuntime(Runtime::kInstallBaselineCode, 1);
+  }
+  // Retry from the start after installing baseline code.
+  __ Branch(&start);
+}
+
+}  // namespace
+
+void Builtins::Generate_BaselineEnterAtBytecode(MacroAssembler* masm) {
+  Generate_BaselineEntry(masm, false);
+}
+
+void Builtins::Generate_BaselineEnterAtNextBytecode(MacroAssembler* masm) {
+  Generate_BaselineEntry(masm, true);
+}
+
+void Builtins::Generate_InterpreterOnStackReplacement_ToBaseline(
+    MacroAssembler* masm) {
+  Generate_BaselineEntry(masm, false, true);
+}
+
 void Builtins::Generate_DynamicCheckMapsTrampoline(MacroAssembler* masm) {
   FrameScope scope(masm, StackFrame::MANUAL);
   __ EnterFrame(StackFrame::INTERNAL);
diff --git a/chromium/v8/src/builtins/s390/builtins-s390.cc b/chromium/v8/src/builtins/s390/builtins-s390.cc
index 7711af6e901..0272621ac01 100644
--- a/chromium/v8/src/builtins/s390/builtins-s390.cc
+++ b/chromium/v8/src/builtins/s390/builtins-s390.cc
@@ -6,6 +6,7 @@
 
 #include "src/api/api-arguments.h"
 #include "src/codegen/code-factory.h"
+#include "src/codegen/interface-descriptors-inl.h"
 // For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
 #include "src/codegen/macro-assembler-inl.h"
 #include "src/codegen/register-configuration.h"
@@ -110,7 +111,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     // r3: constructor function
     // r5: new target
 
-    __ InvokeFunctionWithNewTarget(r3, r5, r2, CALL_FUNCTION);
+    __ InvokeFunctionWithNewTarget(r3, r5, r2, InvokeType::kCall);
 
     // Restore context from the frame.
     __ LoadU64(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
@@ -238,7 +239,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
   __ Push(r8);
 
   // Call the function.
-  __ InvokeFunctionWithNewTarget(r3, r5, r2, CALL_FUNCTION);
+  __ InvokeFunctionWithNewTarget(r3, r5, r2, InvokeType::kCall);
 
   // ----------- S t a t e -------------
   //  --                 r0: constructor result
@@ -339,7 +340,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   __ StoreTaggedField(
       r2, FieldMemOperand(r3, JSGeneratorObject::kInputOrDebugPosOffset), r0);
   __ RecordWriteField(r3, JSGeneratorObject::kInputOrDebugPosOffset, r2, r5,
-                      kLRHasNotBeenSaved, kDontSaveFPRegs);
+                      kLRHasNotBeenSaved, SaveFPRegsMode::kIgnore);
 
   // Load suspended function and context.
   __ LoadTaggedPointerField(
@@ -395,18 +396,15 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
       FieldMemOperand(r3, JSGeneratorObject::kParametersAndRegistersOffset));
   {
     Label done_loop, loop;
-    __ mov(r8, r5);
-
     __ bind(&loop);
-    __ SubS64(r8, r8, Operand(1));
+    __ SubS64(r5, r5, Operand(1));
     __ blt(&done_loop);
-    __ ShiftLeftU64(r1, r8, Operand(kTaggedSizeLog2));
+    __ ShiftLeftU64(r1, r5, Operand(kTaggedSizeLog2));
     __ la(scratch, MemOperand(r4, r1));
     __ LoadAnyTaggedField(scratch,
                           FieldMemOperand(scratch, FixedArray::kHeaderSize));
     __ Push(scratch);
     __ b(&loop);
-
     __ bind(&done_loop);
 
     // Push receiver.
@@ -857,8 +855,8 @@ static void ReplaceClosureCodeWithOptimizedCode(MacroAssembler* masm,
   __ mov(scratch1,
          optimized_code);  // Write barrier clobbers scratch1 below.
   __ RecordWriteField(closure, JSFunction::kCodeOffset, scratch1, scratch2,
-                      kLRHasNotBeenSaved, kDontSaveFPRegs, OMIT_REMEMBERED_SET,
-                      OMIT_SMI_CHECK);
+                      kLRHasNotBeenSaved, SaveFPRegsMode::kIgnore,
+                      RememberedSetAction::kOmit, SmiCheck::kOmit);
 }
 
 static void LeaveInterpreterFrame(MacroAssembler* masm, Register scratch1,
@@ -1527,7 +1525,7 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   __ Jump(kJavaScriptCallCodeStartRegister);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtNextBytecode(MacroAssembler* masm) {
   // Get bytecode array and bytecode offset from the stack frame.
   __ LoadU64(kInterpreterBytecodeArrayRegister,
              MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
@@ -1573,7 +1571,7 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
   __ Abort(AbortReason::kInvalidBytecodeAdvance);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeDispatch(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtBytecode(MacroAssembler* masm) {
   Generate_InterpreterEnterBytecode(masm);
 }
 
@@ -1890,6 +1888,7 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
 }
 
 // static
+// TODO(v8:11615): Observe Code::kMaxArguments in CallOrConstructVarargs
 void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
                                                Handle<Code> code) {
   // ----------- S t a t e -------------
@@ -1902,7 +1901,7 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
 
   Register scratch = ip;
 
-  if (masm->emit_debug_code()) {
+  if (FLAG_debug_code) {
     // Allow r4 to be a FixedArray, or a FixedDoubleArray if r6 == 0.
     Label ok, fail;
     __ AssertNotSmi(r4);
@@ -2177,7 +2176,7 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
 
   __ LoadU16(
       r4, FieldMemOperand(r4, SharedFunctionInfo::kFormalParameterCountOffset));
-  __ InvokeFunctionCode(r3, no_reg, r4, r2, JUMP_FUNCTION);
+  __ InvokeFunctionCode(r3, no_reg, r4, r2, InvokeType::kJump);
 
   // The function is a "classConstructor", need to raise an exception.
   __ bind(&class_constructor);
@@ -2549,6 +2548,11 @@ void Builtins::Generate_GenericJSToWasmWrapper(MacroAssembler* masm) {
   // TODO(v8:10701): Implement for this platform.
   __ Trap();
 }
+
+void Builtins::Generate_WasmOnStackReplace(MacroAssembler* masm) {
+  // Only needed on x64.
+  __ Trap();
+}
 #endif  // V8_ENABLE_WEBASSEMBLY
 
 void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
@@ -2561,12 +2565,12 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // sp: stack pointer  (restored as callee's sp after C call)
   // cp: current context  (C callee-saved)
   //
-  // If argv_mode == kArgvInRegister:
+  // If argv_mode == ArgvMode::kRegister:
   // r4: pointer to the first argument
 
   __ mov(r7, r3);
 
-  if (argv_mode == kArgvInRegister) {
+  if (argv_mode == ArgvMode::kRegister) {
     // Move argv into the correct register.
     __ mov(r3, r4);
   } else {
@@ -2594,7 +2598,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
 #endif
 
   __ EnterExitFrame(
-      save_doubles, arg_stack_space,
+      save_doubles == SaveFPRegsMode::kSave, arg_stack_space,
       builtin_exit_frame ? StackFrame::BUILTIN_EXIT : StackFrame::EXIT);
 
   // Store a copy of argc, argv in callee-saved registers for later.
@@ -2657,12 +2661,12 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // r2:r3: result
   // sp: stack pointer
   // fp: frame pointer
-  Register argc = argv_mode == kArgvInRegister
+  Register argc = argv_mode == ArgvMode::kRegister
                       // We don't want to pop arguments so set argc to no_reg.
                       ? no_reg
                       // r6: still holds argc (callee-saved).
                       : r6;
-  __ LeaveExitFrame(save_doubles, argc);
+  __ LeaveExitFrame(save_doubles == SaveFPRegsMode::kSave, argc);
   __ b(r14);
 
   // Handling of exception.
@@ -2916,7 +2920,7 @@ static void CallApiFunctionAndReturn(MacroAssembler* masm,
   // No more valid handles (the result handle was the last one). Restore
   // previous handle scope.
   __ StoreU64(r6, MemOperand(r9, kNextOffset));
-  if (__ emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ LoadU32(r3, MemOperand(r9, kLevelOffset));
     __ CmpS64(r3, r8);
     __ Check(eq, AbortReason::kUnexpectedLevelAfterReturnFromApiCall);
@@ -3464,11 +3468,12 @@ void Builtins::Generate_DynamicCheckMapsTrampoline(MacroAssembler* masm) {
       descriptor.GetRegisterParameter(DynamicCheckMapsDescriptor::kSlot);
   Register handler_arg =
       descriptor.GetRegisterParameter(DynamicCheckMapsDescriptor::kHandler);
-  __ LoadP(handler_arg, MemOperand(fp, CommonFrameConstants::kCallerPCOffset));
-  __ LoadP(
+  __ LoadU64(handler_arg,
+             MemOperand(fp, CommonFrameConstants::kCallerPCOffset));
+  __ LoadU64(
       slot_arg,
       MemOperand(handler_arg, Deoptimizer::kEagerWithResumeImmedArgs1PcOffset));
-  __ LoadP(
+  __ LoadU64(
       handler_arg,
       MemOperand(handler_arg, Deoptimizer::kEagerWithResumeImmedArgs2PcOffset));
 
diff --git a/chromium/v8/src/builtins/setup-builtins-internal.cc b/chromium/v8/src/builtins/setup-builtins-internal.cc
index 348866c9bde..fbcfab56f43 100644
--- a/chromium/v8/src/builtins/setup-builtins-internal.cc
+++ b/chromium/v8/src/builtins/setup-builtins-internal.cc
@@ -11,7 +11,6 @@
 #include "src/compiler/code-assembler.h"
 #include "src/execution/isolate.h"
 #include "src/handles/handles-inl.h"
-#include "src/heap/heap-inl.h"  // For Heap::code_range.
 #include "src/init/setup-isolate.h"
 #include "src/interpreter/bytecodes.h"
 #include "src/interpreter/interpreter-generator.h"
@@ -42,10 +41,10 @@ AssemblerOptions BuiltinAssemblerOptions(Isolate* isolate,
     return options;
   }
 
-  const base::AddressRegion& code_range = isolate->heap()->code_range();
+  const base::AddressRegion& code_region = isolate->heap()->code_region();
   bool pc_relative_calls_fit_in_code_range =
-      !code_range.is_empty() &&
-      std::ceil(static_cast<float>(code_range.size() / MB)) <=
+      !code_region.is_empty() &&
+      std::ceil(static_cast<float>(code_region.size() / MB)) <=
           kMaxPCRelativeCodeRangeInMB;
 
   options.isolate_independent_code = true;
@@ -219,7 +218,7 @@ void SetupIsolateDelegate::PopulateWithPlaceholders(Isolate* isolate) {
 
 // static
 void SetupIsolateDelegate::ReplacePlaceholders(Isolate* isolate) {
-  // Replace references from all code objects to placeholders.
+  // Replace references from all builtin code objects to placeholders.
   Builtins* builtins = isolate->builtins();
   DisallowGarbageCollection no_gc;
   CodeSpaceMemoryModificationScope modification_scope(isolate->heap());
@@ -228,11 +227,8 @@ void SetupIsolateDelegate::ReplacePlaceholders(Isolate* isolate) {
       RelocInfo::ModeMask(RelocInfo::FULL_EMBEDDED_OBJECT) |
       RelocInfo::ModeMask(RelocInfo::COMPRESSED_EMBEDDED_OBJECT) |
       RelocInfo::ModeMask(RelocInfo::RELATIVE_CODE_TARGET);
-  HeapObjectIterator iterator(isolate->heap());
-  for (HeapObject obj = iterator.Next(); !obj.is_null();
-       obj = iterator.Next()) {
-    if (!obj.IsCode()) continue;
-    Code code = Code::cast(obj);
+  for (int i = 0; i < Builtins::builtin_count; i++) {
+    Code code = builtins->builtin(i);
     bool flush_icache = false;
     for (RelocIterator it(code, kRelocMask); !it.done(); it.next()) {
       RelocInfo* rinfo = it.rinfo();
diff --git a/chromium/v8/src/builtins/typed-array-createtypedarray.tq b/chromium/v8/src/builtins/typed-array-createtypedarray.tq
index 6e416ddd98f..6333ebf97fd 100644
--- a/chromium/v8/src/builtins/typed-array-createtypedarray.tq
+++ b/chromium/v8/src/builtins/typed-array-createtypedarray.tq
@@ -19,11 +19,17 @@ extern macro TypedArrayBuiltinsAssembler::SetupTypedArrayEmbedderFields(
 extern runtime ThrowInvalidTypedArrayAlignment(implicit context: Context)(
     Map, String): never;
 
+extern runtime GrowableSharedArrayBufferByteLength(implicit context: Context)(
+    Object): JSAny;
+
 transitioning macro AllocateTypedArray(implicit context: Context)(
     isOnHeap: constexpr bool, map: Map, buffer: JSArrayBuffer,
-    byteOffset: uintptr, byteLength: uintptr, length: uintptr): JSTypedArray {
+    byteOffset: uintptr, byteLength: uintptr, length: uintptr,
+    isLengthTracking: bool): JSTypedArray {
   let elements: ByteArray;
   if constexpr (isOnHeap) {
+    assert(!IsResizableArrayBuffer(buffer));
+    assert(!isLengthTracking);
     elements = AllocateByteArray(byteLength);
   } else {
     elements = kEmptyByteArray;
@@ -53,6 +59,9 @@ transitioning macro AllocateTypedArray(implicit context: Context)(
   typedArray.byte_offset = byteOffset;
   typedArray.byte_length = byteLength;
   typedArray.length = length;
+  typedArray.bit_field.is_length_tracking = isLengthTracking;
+  typedArray.bit_field.is_backed_by_rab =
+      IsResizableArrayBuffer(buffer) && !IsSharedArrayBuffer(buffer);
   typed_array::AllocateJSTypedArrayExternalPointerEntry(typedArray);
   if constexpr (isOnHeap) {
     typed_array::SetJSTypedArrayOnHeapDataPtr(typedArray, elements, byteOffset);
@@ -88,8 +97,10 @@ transitioning macro TypedArrayInitialize(implicit context: Context)(
     const buffer = AllocateEmptyOnHeapBuffer(byteLength);
 
     const isOnHeap: constexpr bool = true;
+    const isLengthTracking: constexpr bool = false;
     const typedArray = AllocateTypedArray(
-        isOnHeap, map, buffer, byteOffset, byteLength, length);
+        isOnHeap, map, buffer, byteOffset, byteLength, length,
+        isLengthTracking);
 
     if constexpr (initialize) {
       const backingStore = typedArray.data_ptr;
@@ -107,8 +118,10 @@ transitioning macro TypedArrayInitialize(implicit context: Context)(
   } label AttachOffHeapBuffer(bufferObj: Object) {
     const buffer = Cast<JSArrayBuffer>(bufferObj) otherwise unreachable;
     const isOnHeap: constexpr bool = false;
+    const isLengthTracking: constexpr bool = false;
     return AllocateTypedArray(
-        isOnHeap, map, buffer, byteOffset, byteLength, length);
+        isOnHeap, map, buffer, byteOffset, byteLength, length,
+        isLengthTracking);
   }
 }
 
@@ -204,8 +217,26 @@ transitioning macro ConstructByTypedArray(implicit context: Context)(
 // 22.2.4.5 TypedArray ( buffer, byteOffset, length )
 // ES #sec-typedarray-buffer-byteoffset-length
 transitioning macro ConstructByArrayBuffer(implicit context: Context)(
-    map: Map, buffer: JSArrayBuffer, byteOffset: JSAny, length: JSAny,
-    elementsInfo: typed_array::TypedArrayElementsInfo): JSTypedArray {
+    target: JSFunction, newTarget: JSReceiver, buffer: JSArrayBuffer,
+    byteOffset: JSAny, length: JSAny): JSTypedArray {
+  let map: Map;
+  const isLengthTracking: bool =
+      IsResizableArrayBuffer(buffer) && (length == Undefined);
+  // Pick the RAB / GSAB map (containing the corresponding RAB / GSAB
+  // ElementsKind). GSAB-backed non-length-tracking TypedArrays behave just like
+  // normal TypedArrays, so exclude them.
+  const rabGsab: bool = IsResizableArrayBuffer(buffer) &&
+      (!IsSharedArrayBuffer(buffer) || isLengthTracking);
+  if (rabGsab) {
+    map = GetDerivedRabGsabMap(target, newTarget);
+  } else {
+    map = GetDerivedMap(target, newTarget);
+  }
+
+  // 5. Let elementSize be the Number value of the Element Size value in Table
+  // 56 for constructorName.
+  const elementsInfo = GetTypedArrayElementsInfo(map);
+
   try {
     // 6. Let offset be ? ToIndex(byteOffset).
     const offset: uintptr = ToIndex(byteOffset) otherwise IfInvalidOffset;
@@ -226,7 +257,13 @@ transitioning macro ConstructByArrayBuffer(implicit context: Context)(
     }
 
     // 10. Let bufferByteLength be buffer.[[ArrayBufferByteLength]].
-    const bufferByteLength: uintptr = buffer.byte_length;
+    let bufferByteLength: uintptr;
+    if (IsResizableArrayBuffer(buffer) && IsSharedArrayBuffer(buffer)) {
+      bufferByteLength = ToIndex(GrowableSharedArrayBufferByteLength(buffer))
+          otherwise unreachable;
+    } else {
+      bufferByteLength = buffer.byte_length;
+    }
 
     // 11. If length is either not present or undefined, then
     if (length == Undefined) {
@@ -261,7 +298,8 @@ transitioning macro ConstructByArrayBuffer(implicit context: Context)(
 
     const isOnHeap: constexpr bool = false;
     return AllocateTypedArray(
-        isOnHeap, map, buffer, offset, newByteLength, newLength);
+        isOnHeap, map, buffer, offset, newByteLength, newLength,
+        isLengthTracking);
   } label IfInvalidAlignment(problemString: String) deferred {
     ThrowInvalidTypedArrayAlignment(map, problemString);
   } label IfInvalidLength deferred {
@@ -286,6 +324,8 @@ transitioning macro TypedArrayCreateByLength(implicit context: Context)(
   //    ValidateTypedArray currently returns the array, not the ViewBuffer.
   const newTypedArray: JSTypedArray =
       ValidateTypedArray(context, newTypedArrayObj, methodName);
+  newTypedArray.bit_field.is_length_tracking = false;
+  newTypedArray.bit_field.is_backed_by_rab = false;
 
   if (IsDetachedBuffer(newTypedArray.buffer)) deferred {
       ThrowTypeError(MessageTemplate::kDetachedOperation, methodName);
@@ -336,21 +376,16 @@ transitioning builtin CreateTypedArray(
   assert(IsConstructor(target));
   // 4. Let O be ? AllocateTypedArray(constructorName, NewTarget,
   // "%TypedArrayPrototype%").
-  const map = GetDerivedMap(target, newTarget);
-
-  // 5. Let elementSize be the Number value of the Element Size value in Table
-  // 56 for constructorName.
-  const elementsInfo = GetTypedArrayElementsInfo(map);
-
   try {
     typeswitch (arg1) {
       case (length: Smi): {
         goto IfConstructByLength(length);
       }
       case (buffer: JSArrayBuffer): {
-        return ConstructByArrayBuffer(map, buffer, arg2, arg3, elementsInfo);
+        return ConstructByArrayBuffer(target, newTarget, buffer, arg2, arg3);
       }
       case (typedArray: JSTypedArray): {
+        // TODO(v8:11111): Support RAB / GSAB.
         ConstructByTypedArray(typedArray) otherwise IfConstructByArrayLike;
       }
       case (obj: JSReceiver): {
@@ -363,9 +398,18 @@ transitioning builtin CreateTypedArray(
       }
     }
   } label IfConstructByLength(length: JSAny) {
+    const map = GetDerivedMap(target, newTarget);
+    // 5. Let elementSize be the Number value of the Element Size value in Table
+    // 56 for constructorName.
+    const elementsInfo = GetTypedArrayElementsInfo(map);
+
     return ConstructByLength(map, length, elementsInfo);
   } label IfConstructByArrayLike(
       arrayLike: JSReceiver, length: uintptr, bufferConstructor: JSReceiver) {
+    const map = GetDerivedMap(target, newTarget);
+    // 5. Let elementSize be the Number value of the Element Size value in Table
+    // 56 for constructorName.
+    const elementsInfo = GetTypedArrayElementsInfo(map);
     return ConstructByArrayLike(
         map, arrayLike, length, elementsInfo, bufferConstructor);
   }
diff --git a/chromium/v8/src/builtins/wasm.tq b/chromium/v8/src/builtins/wasm.tq
index 05a15162040..f859d1e0bf2 100644
--- a/chromium/v8/src/builtins/wasm.tq
+++ b/chromium/v8/src/builtins/wasm.tq
@@ -287,8 +287,9 @@ builtin WasmAllocateRtt(typeIndex: intptr, parent: Map): Map {
 }
 
 builtin WasmAllocateStructWithRtt(rtt: Map): HeapObject {
-  const instanceSize: intptr =
-      unsafe::TimesTaggedSize(Convert<intptr>(rtt.instance_size_in_words));
+  const typeInfo: WasmTypeInfo = %RawDownCast<WasmTypeInfo>(
+      rtt.constructor_or_back_pointer_or_native_context);
+  const instanceSize: intptr = SmiUntag(typeInfo.instance_size);
   const result: HeapObject = unsafe::Allocate(
       instanceSize, AllocationFlag::kAllowLargeObjectAllocation);
   *UnsafeConstCast(&result.map) = rtt;
diff --git a/chromium/v8/src/builtins/x64/builtins-x64.cc b/chromium/v8/src/builtins/x64/builtins-x64.cc
index 5b5e964ef95..7fc7c5dec78 100644
--- a/chromium/v8/src/builtins/x64/builtins-x64.cc
+++ b/chromium/v8/src/builtins/x64/builtins-x64.cc
@@ -8,18 +8,19 @@
 #include "src/base/bits-iterator.h"
 #include "src/base/iterator.h"
 #include "src/codegen/code-factory.h"
-#include "src/common/globals.h"
-#include "src/objects/code.h"
+#include "src/codegen/interface-descriptors-inl.h"
 // For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
 #include "src/codegen/macro-assembler-inl.h"
 #include "src/codegen/register-configuration.h"
 #include "src/codegen/x64/assembler-x64.h"
+#include "src/common/globals.h"
 #include "src/deoptimizer/deoptimizer.h"
 #include "src/execution/frame-constants.h"
 #include "src/execution/frames.h"
 #include "src/heap/heap-inl.h"
 #include "src/logging/counters.h"
 #include "src/objects/cell.h"
+#include "src/objects/code.h"
 #include "src/objects/debug-objects.h"
 #include "src/objects/foreign.h"
 #include "src/objects/heap-number.h"
@@ -118,7 +119,7 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     // rax: number of arguments (untagged)
     // rdi: constructor function
     // rdx: new target
-    __ InvokeFunction(rdi, rdx, rax, CALL_FUNCTION);
+    __ InvokeFunction(rdi, rdx, rax, InvokeType::kCall);
 
     // Restore smi-tagged arguments count from the frame.
     __ movq(rbx, Operand(rbp, ConstructFrameConstants::kLengthOffset));
@@ -242,7 +243,7 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
   __ Push(r8);
 
   // Call the function.
-  __ InvokeFunction(rdi, rdx, rax, CALL_FUNCTION);
+  __ InvokeFunction(rdi, rdx, rax, InvokeType::kCall);
 
   // ----------- S t a t e -------------
   //  -- rax                 constructor result
@@ -383,8 +384,8 @@ void Generate_JSEntryVariant(MacroAssembler* masm, StackFrame::Type type,
 
 #ifdef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
     // Initialize the pointer cage base register.
-    // TODO(syg): Actually make a cage.
-    __ movq(kPointerCageBaseRegister, arg_reg_1);
+    __ LoadRootRelative(kPtrComprCageBaseRegister,
+                        IsolateData::cage_base_offset());
 #endif
   }
 
@@ -560,7 +561,7 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
     // rdx : new_target
 
     // Clear the context before we push it when entering the internal frame.
-    __ Set(rsi, 0);
+    __ Move(rsi, 0);
 
     // Enter an internal frame.
     FrameScope scope(masm, StackFrame::INTERNAL);
@@ -687,9 +688,9 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   __ StoreTaggedField(
       FieldOperand(rdx, JSGeneratorObject::kInputOrDebugPosOffset), rax);
   __ RecordWriteField(rdx, JSGeneratorObject::kInputOrDebugPosOffset, rax, rcx,
-                      kDontSaveFPRegs);
+                      SaveFPRegsMode::kIgnore);
 
-  Register decompr_scratch1 = COMPRESS_POINTERS_BOOL ? r11 : no_reg;
+  Register decompr_scratch1 = COMPRESS_POINTERS_BOOL ? r8 : no_reg;
 
   // Load suspended function and context.
   __ LoadTaggedPointerField(
@@ -740,20 +741,15 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
       rbx, FieldOperand(rdx, JSGeneratorObject::kParametersAndRegistersOffset));
 
   {
-    {
-      Label done_loop, loop;
-      __ movq(r9, rcx);
-
-      __ bind(&loop);
-      __ decq(r9);
-      __ j(less, &done_loop, Label::kNear);
-      __ PushTaggedAnyField(
-          FieldOperand(rbx, r9, times_tagged_size, FixedArray::kHeaderSize),
-          decompr_scratch1);
-      __ jmp(&loop);
-
-      __ bind(&done_loop);
-    }
+    Label done_loop, loop;
+    __ bind(&loop);
+    __ decq(rcx);
+    __ j(less, &done_loop, Label::kNear);
+    __ PushTaggedAnyField(
+        FieldOperand(rbx, rcx, times_tagged_size, FixedArray::kHeaderSize),
+        decompr_scratch1);
+    __ jmp(&loop);
+    __ bind(&done_loop);
 
     // Push the receiver.
     __ PushTaggedPointerField(
@@ -841,7 +837,8 @@ static void ReplaceClosureCodeWithOptimizedCode(MacroAssembler* masm,
                       optimized_code);
   __ movq(scratch1, optimized_code);  // Write barrier clobbers scratch1 below.
   __ RecordWriteField(closure, JSFunction::kCodeOffset, scratch1, scratch2,
-                      kDontSaveFPRegs, OMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
+                      SaveFPRegsMode::kIgnore, RememberedSetAction::kOmit,
+                      SmiCheck::kOmit);
 }
 
 static void LeaveInterpreterFrame(MacroAssembler* masm, Register scratch1,
@@ -1084,7 +1081,7 @@ static void MaybeOptimizeCodeOrTailCallOptimizedCodeSlot(
   __ LoadAnyTaggedField(
       optimized_code_entry,
       FieldOperand(feedback_vector, FeedbackVector::kMaybeOptimizedCodeOffset));
-  TailCallOptimizedCodeSlot(masm, optimized_code_entry, r11, r15, jump_mode);
+  TailCallOptimizedCodeSlot(masm, optimized_code_entry, r8, r15, jump_mode);
 }
 
 // Generate code for entering a JS function with the interpreter.
@@ -1236,10 +1233,11 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ Move(
       kInterpreterDispatchTableRegister,
       ExternalReference::interpreter_dispatch_table_address(masm->isolate()));
-  __ movzxbq(r11, Operand(kInterpreterBytecodeArrayRegister,
-                          kInterpreterBytecodeOffsetRegister, times_1, 0));
+  __ movzxbq(kScratchRegister,
+             Operand(kInterpreterBytecodeArrayRegister,
+                     kInterpreterBytecodeOffsetRegister, times_1, 0));
   __ movq(kJavaScriptCallCodeStartRegister,
-          Operand(kInterpreterDispatchTableRegister, r11,
+          Operand(kInterpreterDispatchTableRegister, kScratchRegister,
                   times_system_pointer_size, 0));
   __ call(kJavaScriptCallCodeStartRegister);
   masm->isolate()->heap()->SetInterpreterEntryReturnPCOffset(masm->pc_offset());
@@ -1259,7 +1257,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
                           kInterpreterBytecodeOffsetRegister, times_1, 0));
   AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
                                 kInterpreterBytecodeOffsetRegister, rbx, rcx,
-                                r11, &do_return);
+                                r8, &do_return);
   __ jmp(&do_dispatch);
 
   __ bind(&do_return);
@@ -1558,15 +1556,16 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   }
 
   // Dispatch to the target bytecode.
-  __ movzxbq(r11, Operand(kInterpreterBytecodeArrayRegister,
-                          kInterpreterBytecodeOffsetRegister, times_1, 0));
+  __ movzxbq(kScratchRegister,
+             Operand(kInterpreterBytecodeArrayRegister,
+                     kInterpreterBytecodeOffsetRegister, times_1, 0));
   __ movq(kJavaScriptCallCodeStartRegister,
-          Operand(kInterpreterDispatchTableRegister, r11,
+          Operand(kInterpreterDispatchTableRegister, kScratchRegister,
                   times_system_pointer_size, 0));
   __ jmp(kJavaScriptCallCodeStartRegister);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtNextBytecode(MacroAssembler* masm) {
   // Get bytecode array and bytecode offset from the stack frame.
   __ movq(kInterpreterBytecodeArrayRegister,
           Operand(rbp, InterpreterFrameConstants::kBytecodeArrayFromFp));
@@ -1587,7 +1586,7 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
   Label if_return;
   AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
                                 kInterpreterBytecodeOffsetRegister, rbx, rcx,
-                                r11, &if_return);
+                                r8, &if_return);
 
   __ bind(&enter_bytecode);
   // Convert new bytecode offset to a Smi and save in the stackframe.
@@ -1611,29 +1610,38 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
   __ Abort(AbortReason::kInvalidBytecodeAdvance);
 }
 
-void Builtins::Generate_InterpreterEnterBytecodeDispatch(MacroAssembler* masm) {
+void Builtins::Generate_InterpreterEnterAtBytecode(MacroAssembler* masm) {
   Generate_InterpreterEnterBytecode(masm);
 }
 
 // static
 void Builtins::Generate_BaselineOutOfLinePrologue(MacroAssembler* masm) {
+  Register feedback_vector = r8;
+  Register optimization_state = rcx;
+  Register return_address = r15;
+
+#ifdef DEBUG
+  for (auto reg : BaselineOutOfLinePrologueDescriptor::registers()) {
+    DCHECK(
+        !AreAliased(feedback_vector, optimization_state, return_address, reg));
+  }
+#endif
+
   auto descriptor = Builtins::CallInterfaceDescriptorFor(
       Builtins::kBaselineOutOfLinePrologue);
   Register closure = descriptor.GetRegisterParameter(
       BaselineOutOfLinePrologueDescriptor::kClosure);
   // Load the feedback vector from the closure.
-  Register feedback_vector = r11;
   __ LoadTaggedPointerField(
       feedback_vector, FieldOperand(closure, JSFunction::kFeedbackCellOffset));
   __ LoadTaggedPointerField(feedback_vector,
                             FieldOperand(feedback_vector, Cell::kValueOffset));
-  if (__ emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ CmpObjectType(feedback_vector, FEEDBACK_VECTOR_TYPE, kScratchRegister);
     __ Assert(equal, AbortReason::kExpectedFeedbackVector);
   }
 
   // Check for an optimization marker.
-  Register optimization_state = rcx;
   Label has_optimized_code_or_marker;
   LoadOptimizationStateAndJumpIfNeedsProcessing(
       masm, optimization_state, feedback_vector, &has_optimized_code_or_marker);
@@ -1642,8 +1650,6 @@ void Builtins::Generate_BaselineOutOfLinePrologue(MacroAssembler* masm) {
   __ incl(
       FieldOperand(feedback_vector, FeedbackVector::kInvocationCountOffset));
 
-  Register return_address = r15;
-
   __ RecordComment("[ Frame Setup");
   // Save the return address, so that we can push it to the end of the newly
   // set-up frame once we're done setting it up.
@@ -1723,8 +1729,8 @@ void Builtins::Generate_BaselineOutOfLinePrologue(MacroAssembler* masm) {
     // return since we may do a runtime call along the way that requires the
     // stack to only contain valid frames.
     __ Drop(1);
-    MaybeOptimizeCodeOrTailCallOptimizedCodeSlot(masm, rcx, feedback_vector,
-                                                 JumpMode::kPushAndReturn);
+    MaybeOptimizeCodeOrTailCallOptimizedCodeSlot(
+        masm, optimization_state, feedback_vector, JumpMode::kPushAndReturn);
     __ Trap();
     __ RecordComment("]");
   }
@@ -1840,7 +1846,7 @@ void Builtins::Generate_NotifyDeoptimized(MacroAssembler* masm) {
 
 void Builtins::Generate_TailCallOptimizedCodeSlot(MacroAssembler* masm) {
   Register optimized_code_entry = kJavaScriptCallCodeStartRegister;
-  TailCallOptimizedCodeSlot(masm, optimized_code_entry, r11, r15,
+  TailCallOptimizedCodeSlot(masm, optimized_code_entry, r8, r15,
                             JumpMode::kJump);
 }
 
@@ -1905,7 +1911,7 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   // Function.prototype.apply() yet, we use a normal Call builtin here.
   __ bind(&no_arguments);
   {
-    __ Set(rax, 0);
+    __ Move(rax, 0);
     __ Jump(masm->isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
   }
 }
@@ -2062,6 +2068,7 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
 }
 
 // static
+// TODO(v8:11615): Observe Code::kMaxArguments in CallOrConstructVarargs
 void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
                                                Handle<Code> code) {
   // ----------- S t a t e -------------
@@ -2072,14 +2079,13 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
   //  -- rdx    : new.target (for [[Construct]])
   //  -- rsp[0] : return address
   // -----------------------------------
-  Register scratch = r11;
 
-  if (masm->emit_debug_code()) {
+  if (FLAG_debug_code) {
     // Allow rbx to be a FixedArray, or a FixedDoubleArray if rcx == 0.
     Label ok, fail;
     __ AssertNotSmi(rbx);
     Register map = r9;
-    __ LoadTaggedPointerField(map, FieldOperand(rbx, HeapObject::kMapOffset));
+    __ LoadMap(map, rbx);
     __ CmpInstanceType(map, FIXED_ARRAY_TYPE);
     __ j(equal, &ok);
     __ CmpInstanceType(map, FIXED_DOUBLE_ARRAY_TYPE);
@@ -2101,13 +2107,13 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
   // including the receiver and the return address.
   {
     Label copy, check;
-    Register src = r8, dest = rsp, num = r9, current = r11;
+    Register src = r8, dest = rsp, num = r9, current = r12;
     __ movq(src, rsp);
     __ leaq(kScratchRegister, Operand(rcx, times_system_pointer_size, 0));
     __ AllocateStackSpace(kScratchRegister);
     __ leaq(num, Operand(rax, 2));  // Number of words to copy.
                                     // +2 for receiver and return address.
-    __ Set(current, 0);
+    __ Move(current, 0);
     __ jmp(&check);
     __ bind(&copy);
     __ movq(kScratchRegister,
@@ -2123,9 +2129,9 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
 
   // Copy the additional arguments onto the stack.
   {
-    Register value = scratch;
+    Register value = r12;
     Register src = rbx, dest = r8, num = rcx, current = r9;
-    __ Set(current, 0);
+    __ Move(current, 0);
     Label done, push, loop;
     __ bind(&loop);
     __ cmpl(current, num);
@@ -2166,7 +2172,7 @@ void Builtins::Generate_CallOrConstructForwardVarargs(MacroAssembler* masm,
   if (mode == CallOrConstructMode::kConstruct) {
     Label new_target_constructor, new_target_not_constructor;
     __ JumpIfSmi(rdx, &new_target_not_constructor, Label::kNear);
-    __ LoadTaggedPointerField(rbx, FieldOperand(rdx, HeapObject::kMapOffset));
+    __ LoadMap(rbx, rdx);
     __ testb(FieldOperand(rbx, Map::kBitFieldOffset),
              Immediate(Map::Bits1::IsConstructorBit::kMask));
     __ j(not_zero, &new_target_constructor, Label::kNear);
@@ -2203,13 +2209,13 @@ void Builtins::Generate_CallOrConstructForwardVarargs(MacroAssembler* masm,
     // including the receiver and the return address.
     {
       Label copy, check;
-      Register src = r9, dest = rsp, num = r12, current = r11;
+      Register src = r9, dest = rsp, num = r12, current = r15;
       __ movq(src, rsp);
       __ leaq(kScratchRegister, Operand(r8, times_system_pointer_size, 0));
       __ AllocateStackSpace(kScratchRegister);
       __ leaq(num, Operand(rax, 2));  // Number of words to copy.
                                       // +2 for receiver and return address.
-      __ Set(current, 0);
+      __ Move(current, 0);
       __ jmp(&check);
       __ bind(&copy);
       __ movq(kScratchRegister,
@@ -2359,7 +2365,7 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
   __ movzxwq(
       rbx, FieldOperand(rdx, SharedFunctionInfo::kFormalParameterCountOffset));
 
-  __ InvokeFunctionCode(rdi, no_reg, rbx, rax, JUMP_FUNCTION);
+  __ InvokeFunctionCode(rdi, no_reg, rbx, rax, InvokeType::kJump);
 
   // The function is a "classConstructor", need to raise an exception.
   __ bind(&class_constructor);
@@ -2592,7 +2598,7 @@ void Builtins::Generate_Construct(MacroAssembler* masm) {
   __ JumpIfSmi(rdi, &non_constructor);
 
   // Check if target has a [[Construct]] internal method.
-  __ LoadTaggedPointerField(rcx, FieldOperand(rdi, HeapObject::kMapOffset));
+  __ LoadMap(rcx, rdi);
   __ testb(FieldOperand(rcx, Map::kBitFieldOffset),
            Immediate(Map::Bits1::IsConstructorBit::kMask));
   __ j(zero, &non_constructor);
@@ -2682,15 +2688,17 @@ void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_BaselineOnStackReplacement(MacroAssembler* masm) {
+  __ movq(kContextRegister,
+          MemOperand(rbp, BaselineFrameConstants::kContextOffset));
   return OnStackReplacement(masm, false);
 }
 
 #if V8_ENABLE_WEBASSEMBLY
 void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
   // The function index was pushed to the stack by the caller as int32.
-  __ Pop(r11);
+  __ Pop(r15);
   // Convert to Smi for the runtime call.
-  __ SmiTag(r11);
+  __ SmiTag(r15);
   {
     HardAbortScope hard_abort(masm);  // Avoid calls to Abort.
     FrameScope scope(masm, StackFrame::WASM_COMPILE_LAZY);
@@ -2717,13 +2725,13 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
     // Push the Wasm instance as an explicit argument to WasmCompileLazy.
     __ Push(kWasmInstanceRegister);
     // Push the function index as second argument.
-    __ Push(r11);
+    __ Push(r15);
     // Initialize the JavaScript context with 0. CEntry will use it to
     // set the current context on the isolate.
     __ Move(kContextRegister, Smi::zero());
     __ CallRuntime(Runtime::kWasmCompileLazy, 2);
     // The entrypoint address is the return value.
-    __ movq(r11, kReturnRegister0);
+    __ movq(r15, kReturnRegister0);
 
     // Restore registers.
     for (DoubleRegister reg : base::Reversed(wasm::kFpParamRegisters)) {
@@ -2737,7 +2745,7 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
     }
   }
   // Finally, jump to the entrypoint.
-  __ jmp(r11);
+  __ jmp(r15);
 }
 
 void Builtins::Generate_WasmDebugBreak(MacroAssembler* masm) {
@@ -2915,7 +2923,7 @@ void Builtins::Generate_GenericJSToWasmWrapper(MacroAssembler* masm) {
   __ LoadExternalPointerField(
       signature,
       FieldOperand(foreign_signature, Foreign::kForeignAddressOffset),
-      kForeignForeignAddressTag);
+      kForeignForeignAddressTag, kScratchRegister);
   foreign_signature = no_reg;
   Register return_count = r8;
   __ movq(return_count,
@@ -3243,28 +3251,17 @@ void Builtins::Generate_GenericJSToWasmWrapper(MacroAssembler* masm) {
       thread_in_wasm_flag_addr,
       MemOperand(kRootRegister, Isolate::thread_in_wasm_flag_address_offset()));
   __ movl(MemOperand(thread_in_wasm_flag_addr, 0), Immediate(1));
-
-  Register jump_table_start = thread_in_wasm_flag_addr;
-  __ movq(jump_table_start,
-          MemOperand(wasm_instance,
-                     wasm::ObjectAccess::ToTagged(
-                         WasmInstanceObject::kJumpTableStartOffset)));
   thread_in_wasm_flag_addr = no_reg;
 
-  Register jump_table_offset = function_data;
-  __ LoadAnyTaggedField(
-      jump_table_offset,
-      MemOperand(
-          function_data,
-          WasmExportedFunctionData::kJumpTableOffsetOffset - kHeapObjectTag));
-
-  // Change from smi to integer.
-  __ SmiUntag(jump_table_offset);
-
-  Register function_entry = jump_table_offset;
-  __ addq(function_entry, jump_table_start);
-  jump_table_offset = no_reg;
-  jump_table_start = no_reg;
+  Register function_entry = function_data;
+  Register scratch = r12;
+  __ LoadExternalPointerField(
+      function_entry,
+      FieldOperand(function_data,
+                   WasmExportedFunctionData::kForeignAddressOffset),
+      kForeignForeignAddressTag, scratch);
+  function_data = no_reg;
+  scratch = no_reg;
 
   // We set the indicating value for the GC to the proper one for Wasm call.
   constexpr int kWasmCallGCScanSlotCount = 0;
@@ -3349,6 +3346,9 @@ void Builtins::Generate_GenericJSToWasmWrapper(MacroAssembler* masm) {
   // Param conversion builtins.
   // -------------------------------------------
   __ bind(&convert_param);
+  // Restore function_data register (which was clobbered by the code above,
+  // but was valid when jumping here earlier).
+  function_data = rdi;
   // The order of pushes is important. We want the heap objects, that should be
   // scanned by GC, to be on the top of the stack.
   // We have to set the indicating value for the GC to the number of values on
@@ -3527,6 +3527,13 @@ void Builtins::Generate_GenericJSToWasmWrapper(MacroAssembler* masm) {
   __ jmp(&compile_wrapper_done);
 }
 
+void Builtins::Generate_WasmOnStackReplace(MacroAssembler* masm) {
+  MemOperand OSRTargetSlot(rbp, -wasm::kOSRTargetOffset);
+  __ movq(kScratchRegister, OSRTargetSlot);
+  __ movq(OSRTargetSlot, Immediate(0));
+  __ jmp(kScratchRegister);
+}
+
 #endif  // V8_ENABLE_WEBASSEMBLY
 
 void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
@@ -3538,7 +3545,7 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   // rsp: stack pointer  (restored after C call)
   // rsi: current context (restored)
   //
-  // If argv_mode == kArgvInRegister:
+  // If argv_mode == ArgvMode::kRegister:
   // r15: pointer to the first argument
 
 #ifdef V8_TARGET_OS_WIN
@@ -3569,15 +3576,15 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   int arg_stack_space =
       kArgExtraStackSpace +
       (result_size <= kMaxRegisterResultSize ? 0 : result_size);
-  if (argv_mode == kArgvInRegister) {
-    DCHECK(save_doubles == kDontSaveFPRegs);
+  if (argv_mode == ArgvMode::kRegister) {
+    DCHECK(save_doubles == SaveFPRegsMode::kIgnore);
     DCHECK(!builtin_exit_frame);
     __ EnterApiExitFrame(arg_stack_space);
     // Move argc into r12 (argv is already in r15).
     __ movq(r12, rax);
   } else {
     __ EnterExitFrame(
-        arg_stack_space, save_doubles == kSaveFPRegs,
+        arg_stack_space, save_doubles == SaveFPRegsMode::kSave,
         builtin_exit_frame ? StackFrame::BUILTIN_EXIT : StackFrame::EXIT);
   }
 
@@ -3641,7 +3648,8 @@ void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
   }
 
   // Exit the JavaScript to C++ exit frame.
-  __ LeaveExitFrame(save_doubles == kSaveFPRegs, argv_mode == kArgvOnStack);
+  __ LeaveExitFrame(save_doubles == SaveFPRegsMode::kSave,
+                    argv_mode == ArgvMode::kStack);
   __ ret(0);
 
   // Handling of exception.
@@ -3866,9 +3874,7 @@ void CallApiFunctionAndReturn(MacroAssembler* masm, Register function_address,
   Register map = rcx;
 
   __ JumpIfSmi(return_value, &ok, Label::kNear);
-  __ LoadTaggedPointerField(map,
-                            FieldOperand(return_value, HeapObject::kMapOffset));
-
+  __ LoadMap(map, return_value);
   __ CmpInstanceType(map, LAST_NAME_TYPE);
   __ j(below_equal, &ok, Label::kNear);
 
@@ -4053,7 +4059,7 @@ void Builtins::Generate_CallApiGetter(MacroAssembler* masm) {
   Register holder = ApiGetterDescriptor::HolderRegister();
   Register callback = ApiGetterDescriptor::CallbackRegister();
   Register scratch = rax;
-  Register decompr_scratch1 = COMPRESS_POINTERS_BOOL ? r11 : no_reg;
+  Register decompr_scratch1 = COMPRESS_POINTERS_BOOL ? r15 : no_reg;
 
   DCHECK(!AreAliased(receiver, holder, callback, scratch, decompr_scratch1));
 
@@ -4116,7 +4122,7 @@ void Builtins::Generate_CallApiGetter(MacroAssembler* masm) {
   __ LoadExternalPointerField(
       api_function_address,
       FieldOperand(scratch, Foreign::kForeignAddressOffset),
-      kForeignForeignAddressTag);
+      kForeignForeignAddressTag, kScratchRegister);
 
   // +3 is to skip prolog, return address and name handle.
   Operand return_value_operand(
@@ -4172,7 +4178,7 @@ void Generate_DeoptimizationEntry(MacroAssembler* masm,
   // We use this to keep the value of the fifth argument temporarily.
   // Unfortunately we can't store it directly in r8 (used for passing
   // this on linux), since it is another parameter passing register on windows.
-  Register arg5 = r11;
+  Register arg5 = r15;
 
   __ movq(arg_reg_3, Immediate(Deoptimizer::kFixedExitSizeMarker));
   // Get the address of the location in the code object
@@ -4192,7 +4198,7 @@ void Generate_DeoptimizationEntry(MacroAssembler* masm,
   __ movq(rax, Operand(rbp, StandardFrameConstants::kFunctionOffset));
   __ bind(&context_check);
   __ movq(arg_reg_1, rax);
-  __ Set(arg_reg_2, static_cast<int>(deopt_kind));
+  __ Move(arg_reg_2, static_cast<int>(deopt_kind));
   // Args 3 and 4 are already in the right registers.
 
   // On windows put the arguments on the stack (PrepareCallCFunction
diff --git a/chromium/v8/src/codegen/arm/assembler-arm-inl.h b/chromium/v8/src/codegen/arm/assembler-arm-inl.h
index 7035fa2492b..f72e27703e9 100644
--- a/chromium/v8/src/codegen/arm/assembler-arm-inl.h
+++ b/chromium/v8/src/codegen/arm/assembler-arm-inl.h
@@ -206,7 +206,7 @@ Operand::Operand(Smi value) : rmode_(RelocInfo::NONE) {
 Operand::Operand(Register rm) : rm_(rm), shift_op_(LSL), shift_imm_(0) {}
 
 void Assembler::CheckBuffer() {
-  if (buffer_space() <= kGap) {
+  if (V8_UNLIKELY(buffer_space() <= kGap)) {
     GrowBuffer();
   }
   MaybeCheckConstPool();
diff --git a/chromium/v8/src/codegen/arm/assembler-arm.cc b/chromium/v8/src/codegen/arm/assembler-arm.cc
index 17a20a6f977..09c57928ffa 100644
--- a/chromium/v8/src/codegen/arm/assembler-arm.cc
+++ b/chromium/v8/src/codegen/arm/assembler-arm.cc
@@ -534,9 +534,8 @@ Assembler::Assembler(const AssemblerOptions& options,
     : AssemblerBase(options, std::move(buffer)),
       pending_32_bit_constants_(),
       scratch_register_list_(ip.bit()) {
-  pending_32_bit_constants_.reserve(kMinNumPendingConstants);
   reloc_info_writer.Reposition(buffer_start_ + buffer_->size(), pc_);
-  next_buffer_check_ = 0;
+  constant_pool_deadline_ = kMaxInt;
   const_pool_blocked_nesting_ = 0;
   no_const_pool_before_ = 0;
   first_const_pool_32_use_ = -1;
@@ -556,7 +555,10 @@ Assembler::Assembler(const AssemblerOptions& options,
   }
 }
 
-Assembler::~Assembler() { DCHECK_EQ(const_pool_blocked_nesting_, 0); }
+Assembler::~Assembler() {
+  DCHECK_EQ(const_pool_blocked_nesting_, 0);
+  DCHECK_EQ(first_const_pool_32_use_, -1);
+}
 
 void Assembler::GetCode(Isolate* isolate, CodeDesc* desc,
                         SafepointTableBuilder* safepoint_table_builder,
@@ -841,7 +843,7 @@ void Assembler::target_at_put(int pos, int target_pos) {
     //      orr dst, dst, #target8_2 << 16
 
     uint32_t target24 = target_pos + (Code::kHeaderSize - kHeapObjectTag);
-    DCHECK(is_uint24(target24));
+    CHECK(is_uint24(target24));
     if (is_uint8(target24)) {
       // If the target fits in a byte then only patch with a mov
       // instruction.
@@ -897,7 +899,7 @@ void Assembler::target_at_put(int pos, int target_pos) {
     instr &= ~kImm24Mask;
   }
   int imm24 = imm26 >> 2;
-  DCHECK(is_int24(imm24));
+  CHECK(is_int24(imm24));
   instr_at_put(pos, instr | (imm24 & kImm24Mask));
 }
 
@@ -1030,10 +1032,53 @@ namespace {
 bool FitsShifter(uint32_t imm32, uint32_t* rotate_imm, uint32_t* immed_8,
                  Instr* instr) {
   // imm32 must be unsigned.
-  for (int rot = 0; rot < 16; rot++) {
-    uint32_t imm8 = base::bits::RotateLeft32(imm32, 2 * rot);
-    if ((imm8 <= 0xFF)) {
-      *rotate_imm = rot;
+  {
+    // 32-bit immediates can be encoded as:
+    //   (8-bit value, 2*N bit left rotation)
+    // e.g. 0xab00 can be encoded as 0xab shifted left by 8 == 2*4, i.e.
+    //   (0xab, 4)
+    //
+    // Check three categories which cover all possible shifter fits:
+    //   1. 0x000000FF: The value is already 8-bit (no shifting necessary),
+    //   2. 0x000FF000: The 8-bit value is somewhere in the middle of the 32-bit
+    //                  value, and
+    //   3. 0xF000000F: The 8-bit value is split over the beginning and end of
+    //                  the 32-bit value.
+
+    // For 0x000000FF.
+    if (imm32 <= 0xFF) {
+      *rotate_imm = 0;
+      *immed_8 = imm32;
+      return true;
+    }
+    // For 0x000FF000, count trailing zeros and shift down to 0x000000FF. Note
+    // that we have to round the trailing zeros down to the nearest multiple of
+    // two, since we can only encode shifts of 2*N. Note also that we know that
+    // imm32 isn't zero, since we already checked if it's less than 0xFF.
+    int half_trailing_zeros = base::bits::CountTrailingZerosNonZero(imm32) / 2;
+    uint32_t imm8 = imm32 >> (half_trailing_zeros * 2);
+    if (imm8 <= 0xFF) {
+      DCHECK_GT(half_trailing_zeros, 0);
+      // Rotating right by trailing_zeros is equivalent to rotating left by
+      // 32 - trailing_zeros. We return rotate_right / 2, so calculate
+      // (32 - trailing_zeros)/2 == 16 - trailing_zeros/2.
+      *rotate_imm = (16 - half_trailing_zeros);
+      *immed_8 = imm8;
+      return true;
+    }
+    // For 0xF000000F, rotate by 16 to get 0x000FF000 and continue as if it
+    // were that case.
+    uint32_t imm32_rot16 = base::bits::RotateLeft32(imm32, 16);
+    half_trailing_zeros =
+        base::bits::CountTrailingZerosNonZero(imm32_rot16) / 2;
+    imm8 = imm32_rot16 >> (half_trailing_zeros * 2);
+    if (imm8 <= 0xFF) {
+      // We've rotated left by 2*8, so we can't have more than that many
+      // trailing zeroes.
+      DCHECK_LT(half_trailing_zeros, 8);
+      // We've already rotated by 2*8, before calculating trailing_zeros/2,
+      // so we need (32 - (16 + trailing_zeros))/2 == 8 - trailing_zeros/2.
+      *rotate_imm = 8 - half_trailing_zeros;
       *immed_8 = imm8;
       return true;
     }
@@ -2258,7 +2303,7 @@ void Assembler::bkpt(uint32_t imm16) {
 }
 
 void Assembler::svc(uint32_t imm24, Condition cond) {
-  DCHECK(is_uint24(imm24));
+  CHECK(is_uint24(imm24));
   emit(cond | 15 * B24 | imm24);
 }
 
@@ -5204,8 +5249,13 @@ void Assembler::ConstantPoolAddEntry(int position, RelocInfo::Mode rmode,
                     (rmode == RelocInfo::CODE_TARGET && value != 0) ||
                     (RelocInfo::IsEmbeddedObjectMode(rmode) && value != 0);
   DCHECK_LT(pending_32_bit_constants_.size(), kMaxNumPending32Constants);
-  if (pending_32_bit_constants_.empty()) {
+  if (first_const_pool_32_use_ < 0) {
+    DCHECK(pending_32_bit_constants_.empty());
+    DCHECK_EQ(constant_pool_deadline_, kMaxInt);
     first_const_pool_32_use_ = position;
+    constant_pool_deadline_ = position + kCheckPoolDeadline;
+  } else {
+    DCHECK(!pending_32_bit_constants_.empty());
   }
   ConstantPoolEntry entry(position, value, sharing_ok, rmode);
 
@@ -5224,7 +5274,7 @@ void Assembler::ConstantPoolAddEntry(int position, RelocInfo::Mode rmode,
     }
   }
 
-  pending_32_bit_constants_.push_back(entry);
+  pending_32_bit_constants_.emplace_back(entry);
 
   // Make sure the constant pool is not emitted in place of the next
   // instruction for which we just recorded relocation info.
@@ -5239,17 +5289,17 @@ void Assembler::ConstantPoolAddEntry(int position, RelocInfo::Mode rmode,
 void Assembler::BlockConstPoolFor(int instructions) {
   int pc_limit = pc_offset() + instructions * kInstrSize;
   if (no_const_pool_before_ < pc_limit) {
-    // Max pool start (if we need a jump and an alignment).
-#ifdef DEBUG
-    int start = pc_limit + kInstrSize + 2 * kPointerSize;
-    DCHECK(pending_32_bit_constants_.empty() ||
-           (start < first_const_pool_32_use_ + kMaxDistToIntPool));
-#endif
     no_const_pool_before_ = pc_limit;
   }
 
-  if (next_buffer_check_ < no_const_pool_before_) {
-    next_buffer_check_ = no_const_pool_before_;
+  // If we're due a const pool check before the block finishes, move it to just
+  // after the block.
+  if (constant_pool_deadline_ < no_const_pool_before_) {
+    // Make sure that the new deadline isn't too late (including a jump and the
+    // constant pool marker).
+    DCHECK_LE(no_const_pool_before_,
+              first_const_pool_32_use_ + kMaxDistToIntPool);
+    constant_pool_deadline_ = no_const_pool_before_;
   }
 }
 
@@ -5265,49 +5315,44 @@ void Assembler::CheckConstPool(bool force_emit, bool require_jump) {
 
   // There is nothing to do if there are no pending constant pool entries.
   if (pending_32_bit_constants_.empty()) {
-    // Calculate the offset of the next check.
-    next_buffer_check_ = pc_offset() + kCheckPoolInterval;
+    // We should only fall into this case if we're either trying to forcing
+    // emission or opportunistically checking after a jump.
+    DCHECK(force_emit || !require_jump);
     return;
   }
 
-  // Check that the code buffer is large enough before emitting the constant
-  // pool (include the jump over the pool and the constant pool marker and
-  // the gap to the relocation information).
-  int jump_instr = require_jump ? kInstrSize : 0;
-  int size_up_to_marker = jump_instr + kInstrSize;
-  int estimated_size_after_marker =
-      pending_32_bit_constants_.size() * kPointerSize;
-  int estimated_size = size_up_to_marker + estimated_size_after_marker;
-
   // We emit a constant pool when:
   //  * requested to do so by parameter force_emit (e.g. after each function).
   //  * the distance from the first instruction accessing the constant pool to
-  //    any of the constant pool entries will exceed its limit the next
-  //    time the pool is checked. This is overly restrictive, but we don't emit
-  //    constant pool entries in-order so it's conservatively correct.
+  //    the first constant pool entry will exceed its limit the next time the
+  //    pool is checked.
   //  * the instruction doesn't require a jump after itself to jump over the
   //    constant pool, and we're getting close to running out of range.
   if (!force_emit) {
-    DCHECK(!pending_32_bit_constants_.empty());
-    bool need_emit = false;
-    int dist32 = pc_offset() + estimated_size - first_const_pool_32_use_;
-    if ((dist32 >= kMaxDistToIntPool - kCheckPoolInterval) ||
-        (!require_jump && (dist32 >= kMaxDistToIntPool / 2))) {
-      need_emit = true;
+    DCHECK_NE(first_const_pool_32_use_, -1);
+    int dist32 = pc_offset() - first_const_pool_32_use_;
+    if (require_jump) {
+      // We should only be on this path if we've exceeded our deadline.
+      DCHECK_GE(dist32, kCheckPoolDeadline);
+    } else if (dist32 < kCheckPoolDeadline / 2) {
+      return;
     }
-    if (!need_emit) return;
   }
 
-  // Deduplicate constants.
-  int size_after_marker = estimated_size_after_marker;
+  int size_after_marker = pending_32_bit_constants_.size() * kPointerSize;
 
+  // Deduplicate constants.
   for (size_t i = 0; i < pending_32_bit_constants_.size(); i++) {
     ConstantPoolEntry& entry = pending_32_bit_constants_[i];
     if (entry.is_merged()) size_after_marker -= kPointerSize;
   }
 
+  // Check that the code buffer is large enough before emitting the constant
+  // pool (include the jump over the pool and the constant pool marker and
+  // the gap to the relocation information).
+  int jump_instr = require_jump ? kInstrSize : 0;
+  int size_up_to_marker = jump_instr + kInstrSize;
   int size = size_up_to_marker + size_after_marker;
-
   int needed_space = size + kGap;
   while (buffer_space() <= needed_space) GrowBuffer();
 
@@ -5331,6 +5376,14 @@ void Assembler::CheckConstPool(bool force_emit, bool require_jump) {
     emit(kConstantPoolMarker |
          EncodeConstantPoolLength(size_after_marker / kPointerSize));
 
+    // The first entry in the constant pool should also be the first
+    CHECK_EQ(first_const_pool_32_use_, pending_32_bit_constants_[0].position());
+    CHECK(!pending_32_bit_constants_[0].is_merged());
+
+    // Make sure we're not emitting the constant too late.
+    CHECK_LE(pc_offset(),
+             first_const_pool_32_use_ + kMaxDistToPcRelativeConstant);
+
     // Emit 32-bit constant pool entries.
     for (size_t i = 0; i < pending_32_bit_constants_.size(); i++) {
       ConstantPoolEntry& entry = pending_32_bit_constants_[i];
@@ -5354,6 +5407,7 @@ void Assembler::CheckConstPool(bool force_emit, bool require_jump) {
         ConstantPoolEntry& merged =
             pending_32_bit_constants_[entry.merged_index()];
         DCHECK(entry.value() == merged.value());
+        DCHECK_LT(merged.position(), entry.position());
         Instr merged_instr = instr_at(merged.position());
         DCHECK(IsLdrPcImmediateOffset(merged_instr));
         delta = GetLdrRegisterImmediateOffset(merged_instr);
@@ -5379,9 +5433,9 @@ void Assembler::CheckConstPool(bool force_emit, bool require_jump) {
     }
   }
 
-  // Since a constant pool was just emitted, move the check offset forward by
-  // the standard interval.
-  next_buffer_check_ = pc_offset() + kCheckPoolInterval;
+  // Since a constant pool was just emitted, we don't need another check until
+  // the next constant pool entry is added.
+  constant_pool_deadline_ = kMaxInt;
 }
 
 PatchingAssembler::PatchingAssembler(const AssemblerOptions& options,
diff --git a/chromium/v8/src/codegen/arm/assembler-arm.h b/chromium/v8/src/codegen/arm/assembler-arm.h
index e0490a68533..04d5eef054d 100644
--- a/chromium/v8/src/codegen/arm/assembler-arm.h
+++ b/chromium/v8/src/codegen/arm/assembler-arm.h
@@ -45,6 +45,7 @@
 #include <memory>
 #include <vector>
 
+#include "src/base/small-vector.h"
 #include "src/codegen/arm/constants-arm.h"
 #include "src/codegen/arm/register-arm.h"
 #include "src/codegen/assembler.h"
@@ -310,7 +311,10 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
 
   ~Assembler() override;
 
-  void AbortedCodeGeneration() override { pending_32_bit_constants_.clear(); }
+  void AbortedCodeGeneration() override {
+    pending_32_bit_constants_.clear();
+    first_const_pool_32_use_ = -1;
+  }
 
   // GetCode emits any pending (non-emitted) code and fills the descriptor desc.
   static constexpr int kNoHandlerTable = 0;
@@ -1148,13 +1152,24 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   static int DecodeShiftImm(Instr instr);
   static Instr PatchShiftImm(Instr instr, int immed);
 
-  // Constants in pools are accessed via pc relative addressing, which can
-  // reach +/-4KB for integer PC-relative loads and +/-1KB for floating-point
+  // Constants are accessed via pc relative addressing, which can reach −4095 to
+  // 4095 for integer PC-relative loads, and −1020 to 1020 for floating-point
   // PC-relative loads, thereby defining a maximum distance between the
-  // instruction and the accessed constant.
-  static constexpr int kMaxDistToIntPool = 4 * KB;
-  // All relocations could be integer, it therefore acts as the limit.
-  static constexpr int kMinNumPendingConstants = 4;
+  // instruction and the accessed constant. Additionally, PC-relative loads
+  // start at a delta from the actual load instruction's PC, so we can add this
+  // on to the (positive) distance.
+  static constexpr int kMaxDistToPcRelativeConstant =
+      4095 + Instruction::kPcLoadDelta;
+  // The constant pool needs to be jumped over, and has a marker, so the actual
+  // distance from the instruction and start of the constant pool has to include
+  // space for these two instructions.
+  static constexpr int kMaxDistToIntPool =
+      kMaxDistToPcRelativeConstant - 2 * kInstrSize;
+  // Experimentally derived as sufficient for ~95% of compiles.
+  static constexpr int kTypicalNumPending32Constants = 32;
+  // The maximum number of pending constants is reached by a sequence of only
+  // constant loads, which limits it to the number of constant loads that can
+  // fit between the first constant load and the distance to the constant pool.
   static constexpr int kMaxNumPending32Constants =
       kMaxDistToIntPool / kInstrSize;
 
@@ -1165,8 +1180,8 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   // Check if is time to emit a constant pool.
   void CheckConstPool(bool force_emit, bool require_jump);
 
-  void MaybeCheckConstPool() {
-    if (pc_offset() >= next_buffer_check_) {
+  V8_INLINE void MaybeCheckConstPool() {
+    if (V8_UNLIKELY(pc_offset() >= constant_pool_deadline_)) {
       CheckConstPool(false, true);
     }
   }
@@ -1192,9 +1207,8 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   // number of call to EndBlockConstpool.
   void StartBlockConstPool() {
     if (const_pool_blocked_nesting_++ == 0) {
-      // Prevent constant pool checks happening by setting the next check to
-      // the biggest possible offset.
-      next_buffer_check_ = kMaxInt;
+      // Prevent constant pool checks happening by resetting the deadline.
+      constant_pool_deadline_ = kMaxInt;
     }
   }
 
@@ -1202,19 +1216,14 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   // StartBlockConstPool to have an effect.
   void EndBlockConstPool() {
     if (--const_pool_blocked_nesting_ == 0) {
+      if (first_const_pool_32_use_ >= 0) {
 #ifdef DEBUG
-      // Max pool start (if we need a jump and an alignment).
-      int start = pc_offset() + kInstrSize + 2 * kPointerSize;
-      // Check the constant pool hasn't been blocked for too long.
-      DCHECK(pending_32_bit_constants_.empty() ||
-             (start < first_const_pool_32_use_ + kMaxDistToIntPool));
+        // Check the constant pool hasn't been blocked for too long.
+        DCHECK_LE(pc_offset(), first_const_pool_32_use_ + kMaxDistToIntPool);
 #endif
-      // Two cases:
-      //  * no_const_pool_before_ >= next_buffer_check_ and the emission is
-      //    still blocked
-      //  * no_const_pool_before_ < next_buffer_check_ and the next emit will
-      //    trigger a check.
-      next_buffer_check_ = no_const_pool_before_;
+        // Reset the constant pool check back to the deadline.
+        constant_pool_deadline_ = first_const_pool_32_use_ + kCheckPoolDeadline;
+      }
     }
   }
 
@@ -1258,7 +1267,8 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   // pending relocation entry per instruction.
 
   // The buffers of pending constant pool entries.
-  std::vector<ConstantPoolEntry> pending_32_bit_constants_;
+  base::SmallVector<ConstantPoolEntry, kTypicalNumPending32Constants>
+      pending_32_bit_constants_;
 
   // Scratch registers available for use by the Assembler.
   RegList scratch_register_list_;
@@ -1268,8 +1278,6 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   // Avoid overflows for displacements etc.
   static const int kMaximalBufferSize = 512 * MB;
 
-  int next_buffer_check_;  // pc offset of next buffer check
-
   // Constant pool generation
   // Pools are emitted in the instruction stream, preferably after unconditional
   // jumps or after returns from functions (in dead code locations).
@@ -1281,11 +1289,16 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   // if so, a relocation info entry is associated to the constant pool entry.
 
   // Repeated checking whether the constant pool should be emitted is rather
-  // expensive. By default we only check again once a number of instructions
-  // has been generated. That also means that the sizing of the buffers is not
-  // an exact science, and that we rely on some slop to not overrun buffers.
-  static constexpr int kCheckPoolIntervalInst = 32;
-  static constexpr int kCheckPoolInterval = kCheckPoolIntervalInst * kInstrSize;
+  // expensive. Instead, we check once a deadline is hit; the deadline being
+  // when there is a possibility that MaybeCheckConstPool won't be called before
+  // kMaxDistToIntPoolWithHeader is exceeded. Since MaybeCheckConstPool is
+  // called in CheckBuffer, this means that kGap is an upper bound on this
+  // check. Use 2 * kGap just to give it some slack around BlockConstPoolScopes.
+  static constexpr int kCheckPoolDeadline = kMaxDistToIntPool - 2 * kGap;
+
+  // pc offset of the upcoming constant pool deadline. Equivalent to
+  // first_const_pool_32_use_ + kCheckPoolDeadline.
+  int constant_pool_deadline_;
 
   // Emission of the constant pool may be blocked in some code sequences.
   int const_pool_blocked_nesting_;  // Block emission if this is not zero.
@@ -1298,7 +1311,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   // The bound position, before this we cannot do instruction elimination.
   int last_bound_pos_;
 
-  inline void CheckBuffer();
+  V8_INLINE void CheckBuffer();
   void GrowBuffer();
 
   // Instruction generation
diff --git a/chromium/v8/src/codegen/arm/cpu-arm.cc b/chromium/v8/src/codegen/arm/cpu-arm.cc
index 47fe4bdb740..88491c5e51c 100644
--- a/chromium/v8/src/codegen/arm/cpu-arm.cc
+++ b/chromium/v8/src/codegen/arm/cpu-arm.cc
@@ -6,7 +6,7 @@
 #ifdef __arm__
 #ifdef __QNXNTO__
 #include <sys/mman.h>  // for cache flushing.
-#undef MAP_TYPE        // NOLINT
+#undef MAP_TYPE
 #elif V8_OS_FREEBSD
 #include <machine/sysarch.h>  // for cache flushing
 #include <sys/types.h>
diff --git a/chromium/v8/src/codegen/arm/interface-descriptors-arm-inl.h b/chromium/v8/src/codegen/arm/interface-descriptors-arm-inl.h
new file mode 100644
index 00000000000..296f72d1578
--- /dev/null
+++ b/chromium/v8/src/codegen/arm/interface-descriptors-arm-inl.h
@@ -0,0 +1,256 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_CODEGEN_ARM_INTERFACE_DESCRIPTORS_ARM_INL_H_
+#define V8_CODEGEN_ARM_INTERFACE_DESCRIPTORS_ARM_INL_H_
+
+#if V8_TARGET_ARCH_ARM
+
+#include "src/codegen/interface-descriptors.h"
+#include "src/execution/frames.h"
+
+namespace v8 {
+namespace internal {
+
+constexpr auto CallInterfaceDescriptor::DefaultRegisterArray() {
+  auto registers = RegisterArray(r0, r1, r2, r3, r4);
+  STATIC_ASSERT(registers.size() == kMaxBuiltinRegisterParams);
+  return registers;
+}
+
+// static
+constexpr auto RecordWriteDescriptor::registers() {
+  return RegisterArray(r0, r1, r2, r3, r4, kReturnRegister0);
+}
+
+// static
+constexpr auto DynamicCheckMapsDescriptor::registers() {
+  return RegisterArray(r0, r1, r2, r3, cp);
+}
+
+// static
+constexpr auto EphemeronKeyBarrierDescriptor::registers() {
+  return RegisterArray(r0, r1, r2, r3, r4, kReturnRegister0);
+}
+
+// static
+constexpr Register LoadDescriptor::ReceiverRegister() { return r1; }
+// static
+constexpr Register LoadDescriptor::NameRegister() { return r2; }
+// static
+constexpr Register LoadDescriptor::SlotRegister() { return r0; }
+
+// static
+constexpr Register LoadWithVectorDescriptor::VectorRegister() { return r3; }
+
+// static
+constexpr Register
+LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
+  return r4;
+}
+
+// static
+constexpr Register StoreDescriptor::ReceiverRegister() { return r1; }
+// static
+constexpr Register StoreDescriptor::NameRegister() { return r2; }
+// static
+constexpr Register StoreDescriptor::ValueRegister() { return r0; }
+// static
+constexpr Register StoreDescriptor::SlotRegister() { return r4; }
+
+// static
+constexpr Register StoreWithVectorDescriptor::VectorRegister() { return r3; }
+
+// static
+constexpr Register StoreTransitionDescriptor::MapRegister() { return r5; }
+
+// static
+constexpr Register ApiGetterDescriptor::HolderRegister() { return r0; }
+// static
+constexpr Register ApiGetterDescriptor::CallbackRegister() { return r3; }
+
+// static
+constexpr Register GrowArrayElementsDescriptor::ObjectRegister() { return r0; }
+// static
+constexpr Register GrowArrayElementsDescriptor::KeyRegister() { return r3; }
+
+// static
+constexpr Register BaselineLeaveFrameDescriptor::ParamsSizeRegister() {
+  return r3;
+}
+// static
+constexpr Register BaselineLeaveFrameDescriptor::WeightRegister() { return r4; }
+
+// static
+// static
+constexpr Register TypeConversionDescriptor::ArgumentRegister() { return r0; }
+
+// static
+constexpr auto TypeofDescriptor::registers() { return RegisterArray(r3); }
+
+// static
+constexpr auto CallTrampolineDescriptor::registers() {
+  // r0 : number of arguments
+  // r1 : the target to call
+  return RegisterArray(r1, r0);
+}
+
+// static
+constexpr auto CallVarargsDescriptor::registers() {
+  // r0 : number of arguments (on the stack, not including receiver)
+  // r1 : the target to call
+  // r4 : arguments list length (untagged)
+  // r2 : arguments list (FixedArray)
+  return RegisterArray(r1, r0, r4, r2);
+}
+
+// static
+constexpr auto CallForwardVarargsDescriptor::registers() {
+  // r0 : number of arguments
+  // r2 : start index (to support rest parameters)
+  // r1 : the target to call
+  return RegisterArray(r1, r0, r2);
+}
+
+// static
+constexpr auto CallFunctionTemplateDescriptor::registers() {
+  // r1 : function template info
+  // r2 : number of arguments (on the stack, not including receiver)
+  return RegisterArray(r1, r2);
+}
+
+// static
+constexpr auto CallWithSpreadDescriptor::registers() {
+  // r0 : number of arguments (on the stack, not including receiver)
+  // r1 : the target to call
+  // r2 : the object to spread
+  return RegisterArray(r1, r0, r2);
+}
+
+// static
+constexpr auto CallWithArrayLikeDescriptor::registers() {
+  // r1 : the target to call
+  // r2 : the arguments list
+  return RegisterArray(r1, r2);
+}
+
+// static
+constexpr auto ConstructVarargsDescriptor::registers() {
+  // r0 : number of arguments (on the stack, not including receiver)
+  // r1 : the target to call
+  // r3 : the new target
+  // r4 : arguments list length (untagged)
+  // r2 : arguments list (FixedArray)
+  return RegisterArray(r1, r3, r0, r4, r2);
+}
+
+// static
+constexpr auto ConstructForwardVarargsDescriptor::registers() {
+  // r0 : number of arguments
+  // r3 : the new target
+  // r2 : start index (to support rest parameters)
+  // r1 : the target to call
+  return RegisterArray(r1, r3, r0, r2);
+}
+
+// static
+constexpr auto ConstructWithSpreadDescriptor::registers() {
+  // r0 : number of arguments (on the stack, not including receiver)
+  // r1 : the target to call
+  // r3 : the new target
+  // r2 : the object to spread
+  return RegisterArray(r1, r3, r0, r2);
+}
+
+// static
+constexpr auto ConstructWithArrayLikeDescriptor::registers() {
+  // r1 : the target to call
+  // r3 : the new target
+  // r2 : the arguments list
+  return RegisterArray(r1, r3, r2);
+}
+
+// static
+constexpr auto ConstructStubDescriptor::registers() {
+  // r0 : number of arguments
+  // r1 : the target to call
+  // r3 : the new target
+  // r2 : allocation site or undefined
+  return RegisterArray(r1, r3, r0, r2);
+}
+
+// static
+constexpr auto AbortDescriptor::registers() { return RegisterArray(r1); }
+
+// static
+constexpr auto CompareDescriptor::registers() { return RegisterArray(r1, r0); }
+
+// static
+constexpr auto Compare_BaselineDescriptor::registers() {
+  // r1: left operand
+  // r0: right operand
+  // r2: feedback slot
+  return RegisterArray(r1, r0, r2);
+}
+
+// static
+constexpr auto BinaryOpDescriptor::registers() { return RegisterArray(r1, r0); }
+
+// static
+constexpr auto BinaryOp_BaselineDescriptor::registers() {
+  // r1: left operand
+  // r0: right operand
+  // r2: feedback slot
+  return RegisterArray(r1, r0, r2);
+}
+
+// static
+constexpr auto ApiCallbackDescriptor::registers() {
+  return RegisterArray(r1,   // kApiFunctionAddress
+                       r2,   // kArgc
+                       r3,   // kCallData
+                       r0);  // kHolder
+}
+
+// static
+constexpr auto InterpreterDispatchDescriptor::registers() {
+  return RegisterArray(
+      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
+      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister);
+}
+
+// static
+constexpr auto InterpreterPushArgsThenCallDescriptor::registers() {
+  return RegisterArray(r0,   // argument count (not including receiver)
+                       r2,   // address of first argument
+                       r1);  // the target callable to be call
+}
+
+// static
+constexpr auto InterpreterPushArgsThenConstructDescriptor::registers() {
+  return RegisterArray(
+      r0,   // argument count (not including receiver)
+      r4,   // address of the first argument
+      r1,   // constructor to call
+      r3,   // new target
+      r2);  // allocation site feedback if available, undefined otherwise
+}
+
+// static
+constexpr auto ResumeGeneratorDescriptor::registers() {
+  return RegisterArray(r0,   // the value to pass to the generator
+                       r1);  // the JSGeneratorObject to resume
+}
+
+// static
+constexpr auto RunMicrotasksEntryDescriptor::registers() {
+  return RegisterArray(r0, r1);
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TARGET_ARCH_ARM
+
+#endif  // V8_CODEGEN_ARM_INTERFACE_DESCRIPTORS_ARM_INL_H_
diff --git a/chromium/v8/src/codegen/arm/interface-descriptors-arm.cc b/chromium/v8/src/codegen/arm/interface-descriptors-arm.cc
deleted file mode 100644
index 53992227ab3..00000000000
--- a/chromium/v8/src/codegen/arm/interface-descriptors-arm.cc
+++ /dev/null
@@ -1,306 +0,0 @@
-// Copyright 2012 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#if V8_TARGET_ARCH_ARM
-
-#include "src/codegen/interface-descriptors.h"
-
-#include "src/execution/frames.h"
-
-namespace v8 {
-namespace internal {
-
-const Register CallInterfaceDescriptor::ContextRegister() { return cp; }
-
-void CallInterfaceDescriptor::DefaultInitializePlatformSpecific(
-    CallInterfaceDescriptorData* data, int register_parameter_count) {
-  const Register default_stub_registers[] = {r0, r1, r2, r3, r4};
-  CHECK_LE(static_cast<size_t>(register_parameter_count),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(register_parameter_count,
-                                   default_stub_registers);
-}
-
-void RecordWriteDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {r0, r1, r2, r3, r4};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void DynamicCheckMapsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register default_stub_registers[] = {r0, r1, r2, r3, cp};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void EphemeronKeyBarrierDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {r0, r1, r2, r3, r4};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-const Register LoadDescriptor::ReceiverRegister() { return r1; }
-const Register LoadDescriptor::NameRegister() { return r2; }
-const Register LoadDescriptor::SlotRegister() { return r0; }
-
-const Register LoadWithVectorDescriptor::VectorRegister() { return r3; }
-
-const Register
-LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
-  return r4;
-}
-
-const Register StoreDescriptor::ReceiverRegister() { return r1; }
-const Register StoreDescriptor::NameRegister() { return r2; }
-const Register StoreDescriptor::ValueRegister() { return r0; }
-const Register StoreDescriptor::SlotRegister() { return r4; }
-
-const Register StoreWithVectorDescriptor::VectorRegister() { return r3; }
-
-const Register StoreTransitionDescriptor::SlotRegister() { return r4; }
-const Register StoreTransitionDescriptor::VectorRegister() { return r3; }
-const Register StoreTransitionDescriptor::MapRegister() { return r5; }
-
-const Register ApiGetterDescriptor::HolderRegister() { return r0; }
-const Register ApiGetterDescriptor::CallbackRegister() { return r3; }
-
-const Register GrowArrayElementsDescriptor::ObjectRegister() { return r0; }
-const Register GrowArrayElementsDescriptor::KeyRegister() { return r3; }
-
-const Register BaselineLeaveFrameDescriptor::ParamsSizeRegister() { return r3; }
-const Register BaselineLeaveFrameDescriptor::WeightRegister() { return r4; }
-
-// static
-const Register TypeConversionDescriptor::ArgumentRegister() { return r0; }
-
-void TypeofDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {r3};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r0 : number of arguments
-  // r1 : the target to call
-  Register registers[] = {r1, r0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r0 : number of arguments (on the stack, not including receiver)
-  // r1 : the target to call
-  // r4 : arguments list length (untagged)
-  // r2 : arguments list (FixedArray)
-  Register registers[] = {r1, r0, r4, r2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r0 : number of arguments
-  // r2 : start index (to support rest parameters)
-  // r1 : the target to call
-  Register registers[] = {r1, r0, r2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallFunctionTemplateDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r1 : function template info
-  // r2 : number of arguments (on the stack, not including receiver)
-  Register registers[] = {r1, r2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r0 : number of arguments (on the stack, not including receiver)
-  // r1 : the target to call
-  // r2 : the object to spread
-  Register registers[] = {r1, r0, r2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r1 : the target to call
-  // r2 : the arguments list
-  Register registers[] = {r1, r2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r0 : number of arguments (on the stack, not including receiver)
-  // r1 : the target to call
-  // r3 : the new target
-  // r4 : arguments list length (untagged)
-  // r2 : arguments list (FixedArray)
-  Register registers[] = {r1, r3, r0, r4, r2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r0 : number of arguments
-  // r3 : the new target
-  // r2 : start index (to support rest parameters)
-  // r1 : the target to call
-  Register registers[] = {r1, r3, r0, r2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r0 : number of arguments (on the stack, not including receiver)
-  // r1 : the target to call
-  // r3 : the new target
-  // r2 : the object to spread
-  Register registers[] = {r1, r3, r0, r2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r1 : the target to call
-  // r3 : the new target
-  // r2 : the arguments list
-  Register registers[] = {r1, r3, r2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructStubDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r0 : number of arguments
-  // r1 : the target to call
-  // r3 : the new target
-  // r2 : allocation site or undefined
-  Register registers[] = {r1, r3, r0, r2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void AbortDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {r1};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CompareDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {r1, r0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void Compare_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r1: left operand
-  // r0: right operand
-  // r2: feedback slot
-  Register registers[] = {r1, r0, r2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void BinaryOpDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {r1, r0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void BinaryOp_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r1: left operand
-  // r0: right operand
-  // r2: feedback slot
-  Register registers[] = {r1, r0, r2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ApiCallbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      r1,  // kApiFunctionAddress
-      r2,  // kArgc
-      r3,  // kCallData
-      r0,  // kHolder
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterDispatchDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
-      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenCallDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      r0,  // argument count (not including receiver)
-      r2,  // address of first argument
-      r1   // the target callable to be call
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenConstructDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      r0,  // argument count (not including receiver)
-      r4,  // address of the first argument
-      r1,  // constructor to call
-      r3,  // new target
-      r2,  // allocation site feedback if available, undefined otherwise
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ResumeGeneratorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      r0,  // the value to pass to the generator
-      r1   // the JSGeneratorObject to resume
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void FrameDropperTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      r1,  // loaded new FP
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void RunMicrotasksEntryDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {r0, r1};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_TARGET_ARCH_ARM
diff --git a/chromium/v8/src/codegen/arm/macro-assembler-arm.cc b/chromium/v8/src/codegen/arm/macro-assembler-arm.cc
index f83eee4a919..d4e12f3092d 100644
--- a/chromium/v8/src/codegen/arm/macro-assembler-arm.cc
+++ b/chromium/v8/src/codegen/arm/macro-assembler-arm.cc
@@ -13,6 +13,7 @@
 #include "src/codegen/callable.h"
 #include "src/codegen/code-factory.h"
 #include "src/codegen/external-reference-table.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/macro-assembler.h"
 #include "src/codegen/register-configuration.h"
 #include "src/debug/debug.h"
@@ -59,7 +60,7 @@ int TurboAssembler::RequiredStackSizeForCallerSaved(SaveFPRegsMode fp_mode,
 
   bytes += NumRegs(list) * kPointerSize;
 
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     bytes += DwVfpRegister::kNumRegisters * DwVfpRegister::kSizeInBytes;
   }
 
@@ -85,7 +86,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
 
   bytes += NumRegs(list) * kPointerSize;
 
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     SaveFPRegs(sp, lr);
     bytes += DwVfpRegister::kNumRegisters * DwVfpRegister::kSizeInBytes;
   }
@@ -96,7 +97,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
 int TurboAssembler::PopCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
                                    Register exclusion2, Register exclusion3) {
   int bytes = 0;
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     RestoreFPRegs(sp, lr);
     bytes += DwVfpRegister::kNumRegisters * DwVfpRegister::kSizeInBytes;
   }
@@ -660,7 +661,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   Label done;
 
   // Skip barrier if writing a smi.
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     JumpIfSmi(value, &done);
   }
 
@@ -668,7 +669,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   // of the object, so so offset must be a multiple of kPointerSize.
   DCHECK(IsAligned(offset, kPointerSize));
 
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label ok;
     UseScratchRegisterScope temps(this);
     Register scratch = temps.Acquire();
@@ -680,7 +681,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   }
 
   RecordWrite(object, Operand(offset - kHeapObjectTag), value, lr_status,
-              save_fp, remembered_set_action, OMIT_SMI_CHECK);
+              save_fp, remembered_set_action, SmiCheck::kOmit);
 
   bind(&done);
 }
@@ -826,7 +827,7 @@ void MacroAssembler::RecordWrite(Register object, Operand offset,
                                  RememberedSetAction remembered_set_action,
                                  SmiCheck smi_check) {
   DCHECK_NE(object, value);
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     {
       UseScratchRegisterScope temps(this);
       Register scratch = temps.Acquire();
@@ -837,7 +838,7 @@ void MacroAssembler::RecordWrite(Register object, Operand offset,
     Check(eq, AbortReason::kWrongAddressOrValuePassedToRecordWrite);
   }
 
-  if ((remembered_set_action == OMIT_REMEMBERED_SET &&
+  if ((remembered_set_action == RememberedSetAction::kOmit &&
        !FLAG_incremental_marking) ||
       FLAG_disable_write_barriers) {
     return;
@@ -847,7 +848,7 @@ void MacroAssembler::RecordWrite(Register object, Operand offset,
   // catch stores of smis and stores into the young generation.
   Label done;
 
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     JumpIfSmi(value, &done);
   }
 
@@ -1435,7 +1436,7 @@ void MacroAssembler::EnterExitFrame(bool save_doubles, int stack_space,
   PushCommonFrame(scratch);
   // Reserve room for saved entry sp.
   sub(sp, fp, Operand(ExitFrameConstants::kFixedFrameSizeFromFp));
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     mov(scratch, Operand::Zero());
     str(scratch, MemOperand(fp, ExitFrameConstants::kSPOffset));
   }
@@ -1622,7 +1623,7 @@ void MacroAssembler::StackOverflowCheck(Register num_args, Register scratch,
 
 void MacroAssembler::InvokePrologue(Register expected_parameter_count,
                                     Register actual_parameter_count,
-                                    Label* done, InvokeFlag flag) {
+                                    Label* done, InvokeType type) {
   Label regular_invoke;
   //  r0: actual arguments count
   //  r1: function (passed through to callee)
@@ -1722,9 +1723,9 @@ void MacroAssembler::CallDebugOnFunctionCall(Register fun, Register new_target,
 void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
                                         Register expected_parameter_count,
                                         Register actual_parameter_count,
-                                        InvokeFlag flag) {
+                                        InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
   DCHECK_EQ(function, r1);
   DCHECK_IMPLIES(new_target.is_valid(), new_target == r3);
 
@@ -1746,17 +1747,19 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
   }
 
   Label done;
-  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, flag);
+  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, type);
   // We call indirectly through the code field in the function to
   // allow recompilation to take effect without changing any of the
   // call sites.
   Register code = kJavaScriptCallCodeStartRegister;
   ldr(code, FieldMemOperand(function, JSFunction::kCodeOffset));
-  if (flag == CALL_FUNCTION) {
-    CallCodeObject(code);
-  } else {
-    DCHECK(flag == JUMP_FUNCTION);
-    JumpCodeObject(code);
+  switch (type) {
+    case InvokeType::kCall:
+      CallCodeObject(code);
+      break;
+    case InvokeType::kJump:
+      JumpCodeObject(code);
+      break;
   }
   b(&done);
 
@@ -1773,9 +1776,9 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
 
 void MacroAssembler::InvokeFunctionWithNewTarget(
     Register fun, Register new_target, Register actual_parameter_count,
-    InvokeFlag flag) {
+    InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
 
   // Contract with called JS functions requires that function is passed in r1.
   DCHECK_EQ(fun, r1);
@@ -1790,15 +1793,15 @@ void MacroAssembler::InvokeFunctionWithNewTarget(
                        SharedFunctionInfo::kFormalParameterCountOffset));
 
   InvokeFunctionCode(fun, new_target, expected_reg, actual_parameter_count,
-                     flag);
+                     type);
 }
 
 void MacroAssembler::InvokeFunction(Register function,
                                     Register expected_parameter_count,
                                     Register actual_parameter_count,
-                                    InvokeFlag flag) {
+                                    InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
 
   // Contract with called JS functions requires that function is passed in r1.
   DCHECK_EQ(function, r1);
@@ -1807,18 +1810,7 @@ void MacroAssembler::InvokeFunction(Register function,
   ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
 
   InvokeFunctionCode(r1, no_reg, expected_parameter_count,
-                     actual_parameter_count, flag);
-}
-
-void MacroAssembler::MaybeDropFrames() {
-  // Check whether we need to drop frames to restart a function on the stack.
-  ExternalReference restart_fp =
-      ExternalReference::debug_restart_fp_address(isolate());
-  Move(r1, restart_fp);
-  ldr(r1, MemOperand(r1));
-  tst(r1, r1);
-  Jump(BUILTIN_CODE(isolate(), FrameDropperTrampoline), RelocInfo::CODE_TARGET,
-       ne);
+                     actual_parameter_count, type);
 }
 
 void MacroAssembler::PushStackHandler() {
@@ -1993,8 +1985,8 @@ void MacroAssembler::JumpToExternalReference(const ExternalReference& builtin,
   DCHECK_EQ(builtin.address() & 1, 1);
 #endif
   Move(r1, builtin);
-  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, kDontSaveFPRegs,
-                                          kArgvOnStack, builtin_exit_frame);
+  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, SaveFPRegsMode::kIgnore,
+                                          ArgvMode::kStack, builtin_exit_frame);
   Jump(code, RelocInfo::CODE_TARGET);
 }
 
@@ -2034,11 +2026,11 @@ void MacroAssembler::DecrementCounter(StatsCounter* counter, int value,
 }
 
 void TurboAssembler::Assert(Condition cond, AbortReason reason) {
-  if (emit_debug_code()) Check(cond, reason);
+  if (FLAG_debug_code) Check(cond, reason);
 }
 
 void TurboAssembler::AssertUnreachable(AbortReason reason) {
-  if (emit_debug_code()) Abort(reason);
+  if (FLAG_debug_code) Abort(reason);
 }
 
 void TurboAssembler::Check(Condition cond, AbortReason reason) {
@@ -2052,11 +2044,11 @@ void TurboAssembler::Check(Condition cond, AbortReason reason) {
 void TurboAssembler::Abort(AbortReason reason) {
   Label abort_start;
   bind(&abort_start);
-#ifdef DEBUG
-  const char* msg = GetAbortReason(reason);
-  RecordComment("Abort message: ");
-  RecordComment(msg);
-#endif
+  if (FLAG_code_comments) {
+    const char* msg = GetAbortReason(reason);
+    RecordComment("Abort message: ");
+    RecordComment(msg);
+  }
 
   // Avoid emitting call to builtin if requested.
   if (trap_on_abort()) {
@@ -2143,7 +2135,7 @@ void MacroAssembler::JumpIfNotSmi(Register value, Label* not_smi_label) {
 }
 
 void MacroAssembler::AssertNotSmi(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     tst(object, Operand(kSmiTagMask));
     Check(ne, AbortReason::kOperandIsASmi);
@@ -2151,7 +2143,7 @@ void MacroAssembler::AssertNotSmi(Register object) {
 }
 
 void MacroAssembler::AssertSmi(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     tst(object, Operand(kSmiTagMask));
     Check(eq, AbortReason::kOperandIsNotASmi);
@@ -2159,7 +2151,7 @@ void MacroAssembler::AssertSmi(Register object) {
 }
 
 void MacroAssembler::AssertConstructor(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     tst(object, Operand(kSmiTagMask));
     Check(ne, AbortReason::kOperandIsASmiAndNotAConstructor);
@@ -2173,7 +2165,7 @@ void MacroAssembler::AssertConstructor(Register object) {
 }
 
 void MacroAssembler::AssertFunction(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     tst(object, Operand(kSmiTagMask));
     Check(ne, AbortReason::kOperandIsASmiAndNotAFunction);
@@ -2187,7 +2179,7 @@ void MacroAssembler::AssertFunction(Register object) {
 }
 
 void MacroAssembler::AssertBoundFunction(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     tst(object, Operand(kSmiTagMask));
     Check(ne, AbortReason::kOperandIsASmiAndNotABoundFunction);
@@ -2199,7 +2191,7 @@ void MacroAssembler::AssertBoundFunction(Register object) {
 }
 
 void MacroAssembler::AssertGeneratorObject(Register object) {
-  if (!emit_debug_code()) return;
+  if (!FLAG_debug_code) return;
   tst(object, Operand(kSmiTagMask));
   Check(ne, AbortReason::kOperandIsASmiAndNotAGeneratorObject);
 
@@ -2229,7 +2221,7 @@ void MacroAssembler::AssertGeneratorObject(Register object) {
 
 void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
                                                      Register scratch) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label done_checking;
     AssertNotSmi(object);
     CompareRoot(object, RootIndex::kUndefinedValue);
@@ -2520,7 +2512,7 @@ void TurboAssembler::CallCFunctionHelper(Register function,
   // running in the simulator. The simulator has its own alignment check which
   // provides more information.
 #if V8_HOST_ARCH_ARM
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     int frame_alignment = base::OS::ActivationFrameAlignment();
     int frame_alignment_mask = frame_alignment - 1;
     if (frame_alignment > kPointerSize) {
diff --git a/chromium/v8/src/codegen/arm/macro-assembler-arm.h b/chromium/v8/src/codegen/arm/macro-assembler-arm.h
index e622d4aa172..3a54f6c45fc 100644
--- a/chromium/v8/src/codegen/arm/macro-assembler-arm.h
+++ b/chromium/v8/src/codegen/arm/macro-assembler-arm.h
@@ -29,8 +29,6 @@ inline MemOperand FieldMemOperand(Register object, int offset) {
   return MemOperand(object, offset - kHeapObjectTag);
 }
 
-enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
-enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
 enum LinkRegisterStatus { kLRHasNotBeenSaved, kLRHasBeenSaved };
 
 Register GetRegisterThatIsNotOneOf(Register reg1, Register reg2 = no_reg,
@@ -656,16 +654,16 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   void RecordWriteField(
       Register object, int offset, Register value, LinkRegisterStatus lr_status,
       SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
   // For a given |object| notify the garbage collector that the slot at |offset|
   // has been written. |value| is the object being stored.
   void RecordWrite(
       Register object, Operand offset, Register value,
       LinkRegisterStatus lr_status, SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
   // Enter exit frame.
   // stack_space - extra stack space, used for alignment before call to C.
@@ -689,7 +687,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // Invoke the JavaScript function code by either calling or jumping.
   void InvokeFunctionCode(Register function, Register new_target,
                           Register expected_parameter_count,
-                          Register actual_parameter_count, InvokeFlag flag);
+                          Register actual_parameter_count, InvokeType type);
 
   // On function call, call into the debugger.
   void CallDebugOnFunctionCall(Register fun, Register new_target,
@@ -700,13 +698,10 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // current context to the context in the function before invoking.
   void InvokeFunctionWithNewTarget(Register function, Register new_target,
                                    Register actual_parameter_count,
-                                   InvokeFlag flag);
+                                   InvokeType type);
 
   void InvokeFunction(Register function, Register expected_parameter_count,
-                      Register actual_parameter_count, InvokeFlag flag);
-
-  // Frame restart support
-  void MaybeDropFrames();
+                      Register actual_parameter_count, InvokeType type);
 
   // Exception handling
 
@@ -784,18 +779,18 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
 
   // Call a runtime routine.
   void CallRuntime(const Runtime::Function* f, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs);
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore);
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId fid,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     const Runtime::Function* function = Runtime::FunctionForId(fid);
     CallRuntime(function, function->nargs, save_doubles);
   }
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId fid, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     CallRuntime(Runtime::FunctionForId(fid), num_arguments, save_doubles);
   }
 
@@ -874,7 +869,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // Helper functions for generating invokes.
   void InvokePrologue(Register expected_parameter_count,
                       Register actual_parameter_count, Label* done,
-                      InvokeFlag flag);
+                      InvokeType type);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(MacroAssembler);
 };
diff --git a/chromium/v8/src/codegen/arm64/assembler-arm64-inl.h b/chromium/v8/src/codegen/arm64/assembler-arm64-inl.h
index ee64dbe1f26..2668502f816 100644
--- a/chromium/v8/src/codegen/arm64/assembler-arm64-inl.h
+++ b/chromium/v8/src/codegen/arm64/assembler-arm64-inl.h
@@ -1072,12 +1072,12 @@ const Register& Assembler::AppropriateZeroRegFor(const CPURegister& reg) const {
 
 inline void Assembler::CheckBufferSpace() {
   DCHECK_LT(pc_, buffer_start_ + buffer_->size());
-  if (buffer_space() < kGap) {
+  if (V8_UNLIKELY(buffer_space() < kGap)) {
     GrowBuffer();
   }
 }
 
-inline void Assembler::CheckBuffer() {
+V8_INLINE void Assembler::CheckBuffer() {
   CheckBufferSpace();
   if (pc_offset() >= next_veneer_pool_check_) {
     CheckVeneerPool(false, true);
@@ -1085,6 +1085,10 @@ inline void Assembler::CheckBuffer() {
   constpool_.MaybeCheck();
 }
 
+EnsureSpace::EnsureSpace(Assembler* assembler) : block_pools_scope_(assembler) {
+  assembler->CheckBufferSpace();
+}
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/chromium/v8/src/codegen/arm64/assembler-arm64.h b/chromium/v8/src/codegen/arm64/assembler-arm64.h
index aa2ffb26cdf..9d8b135954b 100644
--- a/chromium/v8/src/codegen/arm64/assembler-arm64.h
+++ b/chromium/v8/src/codegen/arm64/assembler-arm64.h
@@ -2634,7 +2634,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   }
 
   void GrowBuffer();
-  void CheckBufferSpace();
+  V8_INLINE void CheckBufferSpace();
   void CheckBuffer();
 
   // Emission of the veneer pools may be blocked in some code sequences.
@@ -2786,9 +2786,7 @@ class PatchingAssembler : public Assembler {
 
 class EnsureSpace {
  public:
-  explicit EnsureSpace(Assembler* assembler) : block_pools_scope_(assembler) {
-    assembler->CheckBufferSpace();
-  }
+  explicit V8_INLINE EnsureSpace(Assembler* assembler);
 
  private:
   Assembler::BlockPoolsScope block_pools_scope_;
diff --git a/chromium/v8/src/codegen/arm64/cpu-arm64.cc b/chromium/v8/src/codegen/arm64/cpu-arm64.cc
index d7bd4834b0e..4baf2e07ec4 100644
--- a/chromium/v8/src/codegen/arm64/cpu-arm64.cc
+++ b/chromium/v8/src/codegen/arm64/cpu-arm64.cc
@@ -23,7 +23,7 @@ class CacheLineSizes {
     cache_type_register_ = 0;
 #else
     // Copy the content of the cache type register to a core register.
-    __asm__ __volatile__("mrs %x[ctr], ctr_el0"  // NOLINT
+    __asm__ __volatile__("mrs %x[ctr], ctr_el0"
                          : [ctr] "=r"(cache_type_register_));
 #endif
   }
@@ -64,9 +64,8 @@ void CpuFeatures::FlushICache(void* address, size_t length) {
   uintptr_t istart = start & ~(isize - 1);
   uintptr_t end = start + length;
 
-  __asm__ __volatile__(  // NOLINT
-                         // Clean every line of the D cache containing the
-                         // target data.
+  __asm__ __volatile__(
+      // Clean every line of the D cache containing the target data.
       "0:                                \n\t"
       // dc       : Data Cache maintenance
       //    c     : Clean
@@ -111,7 +110,7 @@ void CpuFeatures::FlushICache(void* address, size_t length) {
       : [dsize] "r"(dsize), [isize] "r"(isize), [end] "r"(end)
       // This code does not write to memory but without the dependency gcc might
       // move this code before the code is generated.
-      : "cc", "memory");  // NOLINT
+      : "cc", "memory");
 #endif  // V8_OS_WIN
 #endif  // V8_HOST_ARCH_ARM64
 }
diff --git a/chromium/v8/src/codegen/arm64/interface-descriptors-arm64-inl.h b/chromium/v8/src/codegen/arm64/interface-descriptors-arm64-inl.h
new file mode 100644
index 00000000000..90123dbdcb1
--- /dev/null
+++ b/chromium/v8/src/codegen/arm64/interface-descriptors-arm64-inl.h
@@ -0,0 +1,265 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_CODEGEN_ARM64_INTERFACE_DESCRIPTORS_ARM64_INL_H_
+#define V8_CODEGEN_ARM64_INTERFACE_DESCRIPTORS_ARM64_INL_H_
+
+#if V8_TARGET_ARCH_ARM64
+
+#include "src/base/template-utils.h"
+#include "src/codegen/interface-descriptors.h"
+#include "src/execution/frames.h"
+
+namespace v8 {
+namespace internal {
+
+constexpr auto CallInterfaceDescriptor::DefaultRegisterArray() {
+  auto registers = RegisterArray(x0, x1, x2, x3, x4);
+  STATIC_ASSERT(registers.size() == kMaxBuiltinRegisterParams);
+  return registers;
+}
+
+// static
+constexpr auto RecordWriteDescriptor::registers() {
+  return RegisterArray(x0, x1, x2, x3, x4, kReturnRegister0);
+}
+
+// static
+constexpr auto DynamicCheckMapsDescriptor::registers() {
+  return RegisterArray(x0, x1, x2, x3, cp);
+}
+
+// static
+constexpr auto EphemeronKeyBarrierDescriptor::registers() {
+  return RegisterArray(x0, x1, x2, x3, x4, kReturnRegister0);
+}
+
+// static
+constexpr Register LoadDescriptor::ReceiverRegister() { return x1; }
+// static
+constexpr Register LoadDescriptor::NameRegister() { return x2; }
+// static
+constexpr Register LoadDescriptor::SlotRegister() { return x0; }
+
+// static
+constexpr Register LoadWithVectorDescriptor::VectorRegister() { return x3; }
+
+// static
+constexpr Register
+LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
+  return x4;
+}
+
+// static
+constexpr Register StoreDescriptor::ReceiverRegister() { return x1; }
+// static
+constexpr Register StoreDescriptor::NameRegister() { return x2; }
+// static
+constexpr Register StoreDescriptor::ValueRegister() { return x0; }
+// static
+constexpr Register StoreDescriptor::SlotRegister() { return x4; }
+
+// static
+constexpr Register StoreWithVectorDescriptor::VectorRegister() { return x3; }
+
+// static
+constexpr Register StoreTransitionDescriptor::MapRegister() { return x5; }
+
+// static
+constexpr Register ApiGetterDescriptor::HolderRegister() { return x0; }
+// static
+constexpr Register ApiGetterDescriptor::CallbackRegister() { return x3; }
+
+// static
+constexpr Register GrowArrayElementsDescriptor::ObjectRegister() { return x0; }
+// static
+constexpr Register GrowArrayElementsDescriptor::KeyRegister() { return x3; }
+
+// static
+constexpr Register BaselineLeaveFrameDescriptor::ParamsSizeRegister() {
+  return x3;
+}
+// static
+constexpr Register BaselineLeaveFrameDescriptor::WeightRegister() { return x4; }
+
+// static
+// static
+constexpr Register TypeConversionDescriptor::ArgumentRegister() { return x0; }
+
+// static
+constexpr auto TypeofDescriptor::registers() { return RegisterArray(x3); }
+
+// static
+constexpr auto CallTrampolineDescriptor::registers() {
+  // x1: target
+  // x0: number of arguments
+  return RegisterArray(x1, x0);
+}
+
+// static
+constexpr auto CallVarargsDescriptor::registers() {
+  // x0 : number of arguments (on the stack, not including receiver)
+  // x1 : the target to call
+  // x4 : arguments list length (untagged)
+  // x2 : arguments list (FixedArray)
+  return RegisterArray(x1, x0, x4, x2);
+}
+
+// static
+constexpr auto CallForwardVarargsDescriptor::registers() {
+  // x1: target
+  // x0: number of arguments
+  // x2: start index (to supported rest parameters)
+  return RegisterArray(x1, x0, x2);
+}
+
+// static
+constexpr auto CallFunctionTemplateDescriptor::registers() {
+  // x1 : function template info
+  // x2 : number of arguments (on the stack, not including receiver)
+  return RegisterArray(x1, x2);
+}
+
+// static
+constexpr auto CallWithSpreadDescriptor::registers() {
+  // x0 : number of arguments (on the stack, not including receiver)
+  // x1 : the target to call
+  // x2 : the object to spread
+  return RegisterArray(x1, x0, x2);
+}
+
+// static
+constexpr auto CallWithArrayLikeDescriptor::registers() {
+  // x1 : the target to call
+  // x2 : the arguments list
+  return RegisterArray(x1, x2);
+}
+
+// static
+constexpr auto ConstructVarargsDescriptor::registers() {
+  // x0 : number of arguments (on the stack, not including receiver)
+  // x1 : the target to call
+  // x3 : the new target
+  // x4 : arguments list length (untagged)
+  // x2 : arguments list (FixedArray)
+  return RegisterArray(x1, x3, x0, x4, x2);
+}
+
+// static
+constexpr auto ConstructForwardVarargsDescriptor::registers() {
+  // x3: new target
+  // x1: target
+  // x0: number of arguments
+  // x2: start index (to supported rest parameters)
+  return RegisterArray(x1, x3, x0, x2);
+}
+
+// static
+constexpr auto ConstructWithSpreadDescriptor::registers() {
+  // x0 : number of arguments (on the stack, not including receiver)
+  // x1 : the target to call
+  // x3 : the new target
+  // x2 : the object to spread
+  return RegisterArray(x1, x3, x0, x2);
+}
+
+// static
+constexpr auto ConstructWithArrayLikeDescriptor::registers() {
+  // x1 : the target to call
+  // x3 : the new target
+  // x2 : the arguments list
+  return RegisterArray(x1, x3, x2);
+}
+
+// static
+constexpr auto ConstructStubDescriptor::registers() {
+  // x3: new target
+  // x1: target
+  // x0: number of arguments
+  // x2: allocation site or undefined
+  return RegisterArray(x1, x3, x0, x2);
+}
+
+// static
+constexpr auto AbortDescriptor::registers() { return RegisterArray(x1); }
+
+// static
+constexpr auto CompareDescriptor::registers() {
+  // x1: left operand
+  // x0: right operand
+  return RegisterArray(x1, x0);
+}
+
+// static
+constexpr auto Compare_BaselineDescriptor::registers() {
+  // x1: left operand
+  // x0: right operand
+  // x2: feedback slot
+  return RegisterArray(x1, x0, x2);
+}
+
+// static
+constexpr auto BinaryOpDescriptor::registers() {
+  // x1: left operand
+  // x0: right operand
+  return RegisterArray(x1, x0);
+}
+
+// static
+constexpr auto BinaryOp_BaselineDescriptor::registers() {
+  // x1: left operand
+  // x0: right operand
+  // x2: feedback slot
+  return RegisterArray(x1, x0, x2);
+}
+
+// static
+constexpr auto ApiCallbackDescriptor::registers() {
+  return RegisterArray(x1,   // kApiFunctionAddress
+                       x2,   // kArgc
+                       x3,   // kCallData
+                       x0);  // kHolder
+}
+
+// static
+constexpr auto InterpreterDispatchDescriptor::registers() {
+  return RegisterArray(
+      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
+      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister);
+}
+
+// static
+constexpr auto InterpreterPushArgsThenCallDescriptor::registers() {
+  return RegisterArray(x0,   // argument count (not including receiver)
+                       x2,   // address of first argument
+                       x1);  // the target callable to be call
+}
+
+// static
+constexpr auto InterpreterPushArgsThenConstructDescriptor::registers() {
+  return RegisterArray(
+      x0,   // argument count (not including receiver)
+      x4,   // address of the first argument
+      x1,   // constructor to call
+      x3,   // new target
+      x2);  // allocation site feedback if available, undefined otherwise
+}
+
+// static
+constexpr auto ResumeGeneratorDescriptor::registers() {
+  return RegisterArray(x0,   // the value to pass to the generator
+                       x1);  // the JSGeneratorObject to resume
+}
+
+// static
+constexpr auto RunMicrotasksEntryDescriptor::registers() {
+  return RegisterArray(x0, x1);
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TARGET_ARCH_ARM64
+
+#endif  // V8_CODEGEN_ARM64_INTERFACE_DESCRIPTORS_ARM64_INL_H_
diff --git a/chromium/v8/src/codegen/arm64/interface-descriptors-arm64.cc b/chromium/v8/src/codegen/arm64/interface-descriptors-arm64.cc
deleted file mode 100644
index 246d6fc9610..00000000000
--- a/chromium/v8/src/codegen/arm64/interface-descriptors-arm64.cc
+++ /dev/null
@@ -1,310 +0,0 @@
-// Copyright 2012 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#if V8_TARGET_ARCH_ARM64
-
-#include "src/codegen/interface-descriptors.h"
-
-#include "src/execution/frames.h"
-
-namespace v8 {
-namespace internal {
-
-const Register CallInterfaceDescriptor::ContextRegister() { return cp; }
-
-void CallInterfaceDescriptor::DefaultInitializePlatformSpecific(
-    CallInterfaceDescriptorData* data, int register_parameter_count) {
-  const Register default_stub_registers[] = {x0, x1, x2, x3, x4};
-  CHECK_LE(static_cast<size_t>(register_parameter_count),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(register_parameter_count,
-                                   default_stub_registers);
-}
-
-void RecordWriteDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {x0, x1, x2, x3, x4};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void DynamicCheckMapsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register default_stub_registers[] = {x0, x1, x2, x3, cp};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void EphemeronKeyBarrierDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {x0, x1, x2, x3, x4};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-const Register LoadDescriptor::ReceiverRegister() { return x1; }
-const Register LoadDescriptor::NameRegister() { return x2; }
-const Register LoadDescriptor::SlotRegister() { return x0; }
-
-const Register LoadWithVectorDescriptor::VectorRegister() { return x3; }
-
-const Register
-LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
-  return x4;
-}
-
-const Register StoreDescriptor::ReceiverRegister() { return x1; }
-const Register StoreDescriptor::NameRegister() { return x2; }
-const Register StoreDescriptor::ValueRegister() { return x0; }
-const Register StoreDescriptor::SlotRegister() { return x4; }
-
-const Register StoreWithVectorDescriptor::VectorRegister() { return x3; }
-
-const Register StoreTransitionDescriptor::SlotRegister() { return x4; }
-const Register StoreTransitionDescriptor::VectorRegister() { return x3; }
-const Register StoreTransitionDescriptor::MapRegister() { return x5; }
-
-const Register ApiGetterDescriptor::HolderRegister() { return x0; }
-const Register ApiGetterDescriptor::CallbackRegister() { return x3; }
-
-const Register GrowArrayElementsDescriptor::ObjectRegister() { return x0; }
-const Register GrowArrayElementsDescriptor::KeyRegister() { return x3; }
-
-const Register BaselineLeaveFrameDescriptor::ParamsSizeRegister() { return x3; }
-const Register BaselineLeaveFrameDescriptor::WeightRegister() { return x4; }
-
-// static
-const Register TypeConversionDescriptor::ArgumentRegister() { return x0; }
-
-void TypeofDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {x3};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // x1: target
-  // x0: number of arguments
-  Register registers[] = {x1, x0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // x0 : number of arguments (on the stack, not including receiver)
-  // x1 : the target to call
-  // x4 : arguments list length (untagged)
-  // x2 : arguments list (FixedArray)
-  Register registers[] = {x1, x0, x4, x2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // x1: target
-  // x0: number of arguments
-  // x2: start index (to supported rest parameters)
-  Register registers[] = {x1, x0, x2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallFunctionTemplateDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // x1 : function template info
-  // x2 : number of arguments (on the stack, not including receiver)
-  Register registers[] = {x1, x2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // x0 : number of arguments (on the stack, not including receiver)
-  // x1 : the target to call
-  // x2 : the object to spread
-  Register registers[] = {x1, x0, x2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // x1 : the target to call
-  // x2 : the arguments list
-  Register registers[] = {x1, x2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // x0 : number of arguments (on the stack, not including receiver)
-  // x1 : the target to call
-  // x3 : the new target
-  // x4 : arguments list length (untagged)
-  // x2 : arguments list (FixedArray)
-  Register registers[] = {x1, x3, x0, x4, x2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // x3: new target
-  // x1: target
-  // x0: number of arguments
-  // x2: start index (to supported rest parameters)
-  Register registers[] = {x1, x3, x0, x2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // x0 : number of arguments (on the stack, not including receiver)
-  // x1 : the target to call
-  // x3 : the new target
-  // x2 : the object to spread
-  Register registers[] = {x1, x3, x0, x2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // x1 : the target to call
-  // x3 : the new target
-  // x2 : the arguments list
-  Register registers[] = {x1, x3, x2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructStubDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // x3: new target
-  // x1: target
-  // x0: number of arguments
-  // x2: allocation site or undefined
-  Register registers[] = {x1, x3, x0, x2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void AbortDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {x1};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CompareDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // x1: left operand
-  // x0: right operand
-  Register registers[] = {x1, x0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void Compare_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // x1: left operand
-  // x0: right operand
-  // x2: feedback slot
-  Register registers[] = {x1, x0, x2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void BinaryOpDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // x1: left operand
-  // x0: right operand
-  Register registers[] = {x1, x0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void BinaryOp_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // x1: left operand
-  // x0: right operand
-  // x2: feedback slot
-  Register registers[] = {x1, x0, x2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ApiCallbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      x1,  // kApiFunctionAddress
-      x2,  // kArgc
-      x3,  // kCallData
-      x0,  // kHolder
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterDispatchDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
-      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenCallDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      x0,  // argument count (not including receiver)
-      x2,  // address of first argument
-      x1   // the target callable to be call
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenConstructDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      x0,  // argument count (not including receiver)
-      x4,  // address of the first argument
-      x1,  // constructor to call
-      x3,  // new target
-      x2,  // allocation site feedback if available, undefined otherwise
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ResumeGeneratorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      x0,  // the value to pass to the generator
-      x1   // the JSGeneratorObject to resume
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void FrameDropperTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      x1,  // loaded new FP
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void RunMicrotasksEntryDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {x0, x1};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_TARGET_ARCH_ARM64
diff --git a/chromium/v8/src/codegen/arm64/macro-assembler-arm64-inl.h b/chromium/v8/src/codegen/arm64/macro-assembler-arm64-inl.h
index 6a33f864ab7..8fb9bbfd7b7 100644
--- a/chromium/v8/src/codegen/arm64/macro-assembler-arm64-inl.h
+++ b/chromium/v8/src/codegen/arm64/macro-assembler-arm64-inl.h
@@ -7,12 +7,12 @@
 
 #include <ctype.h>
 
-#include "src/common/globals.h"
-
 #include "src/base/bits.h"
 #include "src/codegen/arm64/assembler-arm64-inl.h"
 #include "src/codegen/arm64/assembler-arm64.h"
 #include "src/codegen/macro-assembler.h"
+#include "src/common/globals.h"
+#include "src/execution/isolate-data.h"
 
 namespace v8 {
 namespace internal {
@@ -1037,7 +1037,7 @@ void TurboAssembler::InitializeRootRegister() {
   ExternalReference isolate_root = ExternalReference::isolate_root(isolate());
   Mov(kRootRegister, Operand(isolate_root));
 #ifdef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
-  Mov(kPointerCageBaseRegister, Operand(isolate_root));
+  LoadRootRelative(kPtrComprCageBaseRegister, IsolateData::cage_base_offset());
 #endif
 }
 
@@ -1200,7 +1200,7 @@ void TurboAssembler::Poke(const CPURegister& src, const Operand& offset) {
 
   if (offset.IsImmediate()) {
     DCHECK_GE(offset.ImmediateValue(), 0);
-  } else if (emit_debug_code()) {
+  } else if (FLAG_debug_code) {
     Cmp(xzr, offset);
     Check(le, AbortReason::kStackAccessBelowStackPointer);
   }
@@ -1212,7 +1212,7 @@ template <TurboAssembler::LoadLRMode lr_mode>
 void TurboAssembler::Peek(const CPURegister& dst, const Operand& offset) {
   if (offset.IsImmediate()) {
     DCHECK_GE(offset.ImmediateValue(), 0);
-  } else if (emit_debug_code()) {
+  } else if (FLAG_debug_code) {
     Cmp(xzr, offset);
     Check(le, AbortReason::kStackAccessBelowStackPointer);
   }
diff --git a/chromium/v8/src/codegen/arm64/macro-assembler-arm64.cc b/chromium/v8/src/codegen/arm64/macro-assembler-arm64.cc
index a3570b80354..b18ff554553 100644
--- a/chromium/v8/src/codegen/arm64/macro-assembler-arm64.cc
+++ b/chromium/v8/src/codegen/arm64/macro-assembler-arm64.cc
@@ -10,6 +10,7 @@
 #include "src/codegen/callable.h"
 #include "src/codegen/code-factory.h"
 #include "src/codegen/external-reference-table.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/macro-assembler-inl.h"
 #include "src/codegen/register-configuration.h"
 #include "src/codegen/reloc-info.h"
@@ -52,7 +53,7 @@ int TurboAssembler::RequiredStackSizeForCallerSaved(SaveFPRegsMode fp_mode,
 
   int bytes = list.Count() * kXRegSizeInBits / 8;
 
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     DCHECK_EQ(kCallerSavedV.Count() % 2, 0);
     bytes += kCallerSavedV.Count() * kDRegSizeInBits / 8;
   }
@@ -69,7 +70,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode,
 
   int bytes = list.Count() * kXRegSizeInBits / 8;
 
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     DCHECK_EQ(kCallerSavedV.Count() % 2, 0);
     PushCPURegList(kCallerSavedV);
     bytes += kCallerSavedV.Count() * kDRegSizeInBits / 8;
@@ -79,7 +80,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode,
 
 int TurboAssembler::PopCallerSaved(SaveFPRegsMode fp_mode, Register exclusion) {
   int bytes = 0;
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     DCHECK_EQ(kCallerSavedV.Count() % 2, 0);
     PopCPURegList(kCallerSavedV);
     bytes += kCallerSavedV.Count() * kDRegSizeInBits / 8;
@@ -1266,7 +1267,7 @@ void MacroAssembler::PopCalleeSavedRegisters() {
 }
 
 void TurboAssembler::AssertSpAligned() {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     HardAbortScope hard_abort(this);  // Avoid calls to Abort.
     // Arm64 requires the stack pointer to be 16-byte aligned prior to address
     // calculation.
@@ -1299,7 +1300,7 @@ void TurboAssembler::CopyDoubleWords(Register dst, Register src, Register count,
                                      CopyDoubleWordsMode mode) {
   DCHECK(!AreAliased(dst, src, count));
 
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Register pointer1 = dst;
     Register pointer2 = src;
     if (mode == kSrcLessThanDst) {
@@ -1374,7 +1375,7 @@ void TurboAssembler::SlotAddress(Register dst, Register slot_offset) {
 }
 
 void TurboAssembler::AssertFPCRState(Register fpcr) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label unexpected_mode, done;
     UseScratchRegisterScope temps(this);
     if (fpcr.IsNone()) {
@@ -1473,7 +1474,7 @@ void TurboAssembler::Swap(VRegister lhs, VRegister rhs) {
 }
 
 void TurboAssembler::AssertSmi(Register object, AbortReason reason) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     Tst(object, kSmiTagMask);
     Check(eq, reason);
@@ -1481,7 +1482,7 @@ void TurboAssembler::AssertSmi(Register object, AbortReason reason) {
 }
 
 void MacroAssembler::AssertNotSmi(Register object, AbortReason reason) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     Tst(object, kSmiTagMask);
     Check(ne, reason);
@@ -1489,7 +1490,7 @@ void MacroAssembler::AssertNotSmi(Register object, AbortReason reason) {
 }
 
 void MacroAssembler::AssertConstructor(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     AssertNotSmi(object, AbortReason::kOperandIsASmiAndNotAConstructor);
 
     UseScratchRegisterScope temps(this);
@@ -1504,7 +1505,7 @@ void MacroAssembler::AssertConstructor(Register object) {
 }
 
 void MacroAssembler::AssertFunction(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     AssertNotSmi(object, AbortReason::kOperandIsASmiAndNotAFunction);
 
     UseScratchRegisterScope temps(this);
@@ -1517,7 +1518,7 @@ void MacroAssembler::AssertFunction(Register object) {
 }
 
 void MacroAssembler::AssertBoundFunction(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     AssertNotSmi(object, AbortReason::kOperandIsASmiAndNotABoundFunction);
 
     UseScratchRegisterScope temps(this);
@@ -1529,7 +1530,7 @@ void MacroAssembler::AssertBoundFunction(Register object) {
 }
 
 void MacroAssembler::AssertGeneratorObject(Register object) {
-  if (!emit_debug_code()) return;
+  if (!FLAG_debug_code) return;
   AssertNotSmi(object, AbortReason::kOperandIsASmiAndNotAGeneratorObject);
 
   // Load map
@@ -1555,7 +1556,7 @@ void MacroAssembler::AssertGeneratorObject(Register object) {
 }
 
 void MacroAssembler::AssertUndefinedOrAllocationSite(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     UseScratchRegisterScope temps(this);
     Register scratch = temps.AcquireX();
     Label done_checking;
@@ -1569,7 +1570,7 @@ void MacroAssembler::AssertUndefinedOrAllocationSite(Register object) {
 }
 
 void TurboAssembler::AssertPositiveOrZero(Register value) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label done;
     int sign_bit = value.Is64Bits() ? kXSignBit : kWSignBit;
     Tbz(value, sign_bit, &done);
@@ -1599,8 +1600,8 @@ void MacroAssembler::CallRuntime(const Runtime::Function* f, int num_arguments,
 void MacroAssembler::JumpToExternalReference(const ExternalReference& builtin,
                                              bool builtin_exit_frame) {
   Mov(x1, builtin);
-  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, kDontSaveFPRegs,
-                                          kArgvOnStack, builtin_exit_frame);
+  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, SaveFPRegsMode::kIgnore,
+                                          ArgvMode::kStack, builtin_exit_frame);
   Jump(code, RelocInfo::CODE_TARGET);
 }
 
@@ -1942,7 +1943,7 @@ void TurboAssembler::CallBuiltin(int builtin_index) {
     Ldr(scratch, Operand(entry, RelocInfo::OFF_HEAP_TARGET));
     Call(scratch);
   }
-  if (FLAG_code_comments) RecordComment("]");
+  RecordComment("]");
 }
 
 void TurboAssembler::TailCallBuiltin(int builtin_index) {
@@ -1971,7 +1972,7 @@ void TurboAssembler::TailCallBuiltin(int builtin_index) {
     Ldr(temp, Operand(entry, RelocInfo::OFF_HEAP_TARGET));
     Jump(temp);
   }
-  if (FLAG_code_comments) RecordComment("]");
+  RecordComment("]");
 }
 
 void TurboAssembler::LoadCodeObjectEntry(Register destination,
@@ -2059,7 +2060,7 @@ void TurboAssembler::StoreReturnAddressAndCall(Register target) {
 #endif
   Poke(x17, 0);
 
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     // Verify that the slot below fp[kSPOffset]-8 points to the signed return
     // location.
     Ldr(x16, MemOperand(fp, ExitFrameConstants::kSPOffset));
@@ -2189,7 +2190,7 @@ void MacroAssembler::StackOverflowCheck(Register num_args,
 
 void MacroAssembler::InvokePrologue(Register formal_parameter_count,
                                     Register actual_argument_count, Label* done,
-                                    InvokeFlag flag) {
+                                    InvokeType type) {
   //  x0: actual arguments count.
   //  x1: function (passed through to callee).
   //  x2: expected arguments count.
@@ -2320,9 +2321,9 @@ void MacroAssembler::CallDebugOnFunctionCall(Register fun, Register new_target,
 void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
                                         Register expected_parameter_count,
                                         Register actual_parameter_count,
-                                        InvokeFlag flag) {
+                                        InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
   DCHECK_EQ(function, x1);
   DCHECK_IMPLIES(new_target.is_valid(), new_target == x3);
 
@@ -2341,7 +2342,7 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
   }
 
   Label done;
-  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, flag);
+  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, type);
 
   // If actual != expected, InvokePrologue will have handled the call through
   // the argument adaptor mechanism.
@@ -2352,11 +2353,13 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
   Register code = kJavaScriptCallCodeStartRegister;
   LoadTaggedPointerField(code,
                          FieldMemOperand(function, JSFunction::kCodeOffset));
-  if (flag == CALL_FUNCTION) {
-    CallCodeObject(code);
-  } else {
-    DCHECK(flag == JUMP_FUNCTION);
-    JumpCodeObject(code);
+  switch (type) {
+    case InvokeType::kCall:
+      CallCodeObject(code);
+      break;
+    case InvokeType::kJump:
+      JumpCodeObject(code);
+      break;
   }
   B(&done);
 
@@ -2377,9 +2380,9 @@ Operand MacroAssembler::ReceiverOperand(Register arg_count) {
 
 void MacroAssembler::InvokeFunctionWithNewTarget(
     Register function, Register new_target, Register actual_parameter_count,
-    InvokeFlag flag) {
+    InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK(flag == JUMP_FUNCTION || has_frame());
+  DCHECK(type == InvokeType::kJump || has_frame());
 
   // Contract with called JS functions requires that function is passed in x1.
   // (See FullCodeGenerator::Generate().)
@@ -2400,15 +2403,15 @@ void MacroAssembler::InvokeFunctionWithNewTarget(
                        SharedFunctionInfo::kFormalParameterCountOffset));
 
   InvokeFunctionCode(function, new_target, expected_parameter_count,
-                     actual_parameter_count, flag);
+                     actual_parameter_count, type);
 }
 
 void MacroAssembler::InvokeFunction(Register function,
                                     Register expected_parameter_count,
                                     Register actual_parameter_count,
-                                    InvokeFlag flag) {
+                                    InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK(flag == JUMP_FUNCTION || has_frame());
+  DCHECK(type == InvokeType::kJump || has_frame());
 
   // Contract with called JS functions requires that function is passed in x1.
   // (See FullCodeGenerator::Generate().)
@@ -2419,7 +2422,7 @@ void MacroAssembler::InvokeFunction(Register function,
                          FieldMemOperand(function, JSFunction::kContextOffset));
 
   InvokeFunctionCode(function, no_reg, expected_parameter_count,
-                     actual_parameter_count, flag);
+                     actual_parameter_count, type);
 }
 
 void TurboAssembler::TryConvertDoubleToInt64(Register result,
@@ -2664,7 +2667,7 @@ void MacroAssembler::LeaveExitFrame(bool restore_doubles,
       ExternalReference::Create(IsolateAddressId::kContextAddress, isolate()));
   Ldr(cp, MemOperand(scratch));
 
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     // Also emit debug code to clear the cp in the top frame.
     Mov(scratch2, Operand(Context::kInvalidContext));
     Mov(scratch, ExternalReference::Create(IsolateAddressId::kContextAddress,
@@ -2715,15 +2718,6 @@ void MacroAssembler::DecrementCounter(StatsCounter* counter, int value,
   IncrementCounter(counter, -value, scratch1, scratch2);
 }
 
-void MacroAssembler::MaybeDropFrames() {
-  // Check whether we need to drop frames to restart a function on the stack.
-  Mov(x1, ExternalReference::debug_restart_fp_address(isolate()));
-  Ldr(x1, MemOperand(x1));
-  Tst(x1, x1);
-  Jump(BUILTIN_CODE(isolate(), FrameDropperTrampoline), RelocInfo::CODE_TARGET,
-       ne);
-}
-
 void MacroAssembler::JumpIfObjectType(Register object, Register map,
                                       Register type_reg, InstanceType type,
                                       Label* if_cond_pass, Condition cond) {
@@ -2860,14 +2854,14 @@ void TurboAssembler::DecompressTaggedPointer(const Register& destination,
                                              const MemOperand& field_operand) {
   RecordComment("[ DecompressTaggedPointer");
   Ldr(destination.W(), field_operand);
-  Add(destination, kPointerCageBaseRegister, destination);
+  Add(destination, kPtrComprCageBaseRegister, destination);
   RecordComment("]");
 }
 
 void TurboAssembler::DecompressTaggedPointer(const Register& destination,
                                              const Register& source) {
   RecordComment("[ DecompressTaggedPointer");
-  Add(destination, kPointerCageBaseRegister, Operand(source, UXTW));
+  Add(destination, kPtrComprCageBaseRegister, Operand(source, UXTW));
   RecordComment("]");
 }
 
@@ -2875,7 +2869,7 @@ void TurboAssembler::DecompressAnyTagged(const Register& destination,
                                          const MemOperand& field_operand) {
   RecordComment("[ DecompressAnyTagged");
   Ldr(destination.W(), field_operand);
-  Add(destination, kPointerCageBaseRegister, destination);
+  Add(destination, kPtrComprCageBaseRegister, destination);
   RecordComment("]");
 }
 
@@ -2904,7 +2898,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   Label done;
 
   // Skip the barrier if writing a smi.
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     JumpIfSmi(value, &done);
   }
 
@@ -2912,7 +2906,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   // of the object, so offset must be a multiple of kTaggedSize.
   DCHECK(IsAligned(offset, kTaggedSize));
 
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label ok;
     UseScratchRegisterScope temps(this);
     Register scratch = temps.AcquireX();
@@ -2924,7 +2918,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   }
 
   RecordWrite(object, Operand(offset - kHeapObjectTag), value, lr_status,
-              save_fp, remembered_set_action, OMIT_SMI_CHECK);
+              save_fp, remembered_set_action, SmiCheck::kOmit);
 
   Bind(&done);
 }
@@ -3069,7 +3063,7 @@ void MacroAssembler::RecordWrite(Register object, Operand offset,
   ASM_LOCATION_IN_ASSEMBLER("MacroAssembler::RecordWrite");
   DCHECK(!AreAliased(object, value));
 
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     UseScratchRegisterScope temps(this);
     Register temp = temps.AcquireX();
 
@@ -3079,7 +3073,7 @@ void MacroAssembler::RecordWrite(Register object, Operand offset,
     Check(eq, AbortReason::kWrongAddressOrValuePassedToRecordWrite);
   }
 
-  if ((remembered_set_action == OMIT_REMEMBERED_SET &&
+  if ((remembered_set_action == RememberedSetAction::kOmit &&
        !FLAG_incremental_marking) ||
       FLAG_disable_write_barriers) {
     return;
@@ -3089,7 +3083,7 @@ void MacroAssembler::RecordWrite(Register object, Operand offset,
   // catch stores of smis and stores into the young generation.
   Label done;
 
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     DCHECK_EQ(0, kSmiTag);
     JumpIfSmi(value, &done);
   }
@@ -3112,13 +3106,13 @@ void MacroAssembler::RecordWrite(Register object, Operand offset,
 }
 
 void TurboAssembler::Assert(Condition cond, AbortReason reason) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Check(cond, reason);
   }
 }
 
 void TurboAssembler::AssertUnreachable(AbortReason reason) {
-  if (emit_debug_code()) Abort(reason);
+  if (FLAG_debug_code) Abort(reason);
 }
 
 void TurboAssembler::Check(Condition cond, AbortReason reason) {
@@ -3133,10 +3127,10 @@ void TurboAssembler::Trap() { Brk(0); }
 void TurboAssembler::DebugBreak() { Debug("DebugBreak", 0, BREAK); }
 
 void TurboAssembler::Abort(AbortReason reason) {
-#ifdef DEBUG
-  RecordComment("Abort message: ");
-  RecordComment(GetAbortReason(reason));
-#endif
+  if (FLAG_code_comments) {
+    RecordComment("Abort message: ");
+    RecordComment(GetAbortReason(reason));
+  }
 
   // Avoid emitting call to builtin if requested.
   if (trap_on_abort()) {
diff --git a/chromium/v8/src/codegen/arm64/macro-assembler-arm64.h b/chromium/v8/src/codegen/arm64/macro-assembler-arm64.h
index a749676cccd..7bc6432c360 100644
--- a/chromium/v8/src/codegen/arm64/macro-assembler-arm64.h
+++ b/chromium/v8/src/codegen/arm64/macro-assembler-arm64.h
@@ -126,8 +126,6 @@ inline BranchType InvertBranchType(BranchType type) {
   }
 }
 
-enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
-enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
 enum LinkRegisterStatus { kLRHasNotBeenSaved, kLRHasBeenSaved };
 enum DiscardMoveMode { kDontDiscardForSameWReg, kDiscardForSameWReg };
 
@@ -1849,17 +1847,17 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // ---- Calling / Jumping helpers ----
 
   void CallRuntime(const Runtime::Function* f, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs);
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore);
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId fid, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     CallRuntime(Runtime::FunctionForId(fid), num_arguments, save_doubles);
   }
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId fid,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     const Runtime::Function* function = Runtime::FunctionForId(fid);
     CallRuntime(function, function->nargs, save_doubles);
   }
@@ -1882,7 +1880,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // 'call_kind' must be x5.
   void InvokePrologue(Register expected_parameter_count,
                       Register actual_parameter_count, Label* done,
-                      InvokeFlag flag);
+                      InvokeType type);
 
   // On function call, call into the debugger.
   void CallDebugOnFunctionCall(Register fun, Register new_target,
@@ -1890,20 +1888,17 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
                                Register actual_parameter_count);
   void InvokeFunctionCode(Register function, Register new_target,
                           Register expected_parameter_count,
-                          Register actual_parameter_count, InvokeFlag flag);
+                          Register actual_parameter_count, InvokeType type);
   // Invoke the JavaScript function in the given register.
   // Changes the current context to the context in the function before invoking.
   void InvokeFunctionWithNewTarget(Register function, Register new_target,
                                    Register actual_parameter_count,
-                                   InvokeFlag flag);
+                                   InvokeType type);
   void InvokeFunction(Register function, Register expected_parameter_count,
-                      Register actual_parameter_count, InvokeFlag flag);
+                      Register actual_parameter_count, InvokeType type);
 
   // ---- Code generation helpers ----
 
-  // Frame restart support
-  void MaybeDropFrames();
-
   // ---------------------------------------------------------------------------
   // Support functions.
 
@@ -2032,16 +2027,16 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   void RecordWriteField(
       Register object, int offset, Register value, LinkRegisterStatus lr_status,
       SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
   // For a given |object| notify the garbage collector that the slot at |offset|
   // has been written. |value| is the object being stored.
   void RecordWrite(
       Register object, Operand offset, Register value,
       LinkRegisterStatus lr_status, SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
   // ---------------------------------------------------------------------------
   // Debugging.
diff --git a/chromium/v8/src/codegen/arm64/register-arm64.h b/chromium/v8/src/codegen/arm64/register-arm64.h
index 605856e51c1..1150daf4c60 100644
--- a/chromium/v8/src/codegen/arm64/register-arm64.h
+++ b/chromium/v8/src/codegen/arm64/register-arm64.h
@@ -102,7 +102,7 @@ class CPURegister : public RegisterBase<CPURegister, kRegAfterLast> {
   }
 
   static constexpr CPURegister Create(int code, int size, RegisterType type) {
-    CONSTEXPR_DCHECK(IsValid(code, size, type));
+    DCHECK(IsValid(code, size, type));
     return CPURegister{code, size, type};
   }
 
@@ -320,7 +320,7 @@ class VRegister : public CPURegister {
   }
 
   static constexpr VRegister Create(int code, int size, int lane_count = 1) {
-    CONSTEXPR_DCHECK(IsValidLaneCount(lane_count));
+    DCHECK(IsValidLaneCount(lane_count));
     return VRegister(CPURegister::Create(code, size, CPURegister::kVRegister),
                      lane_count);
   }
@@ -477,9 +477,9 @@ ALIAS_REGISTER(Register, kRootRegister, x26);
 ALIAS_REGISTER(Register, rr, x26);
 // Pointer cage base register.
 #ifdef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
-ALIAS_REGISTER(Register, kPointerCageBaseRegister, x28);
+ALIAS_REGISTER(Register, kPtrComprCageBaseRegister, x28);
 #else
-ALIAS_REGISTER(Register, kPointerCageBaseRegister, kRootRegister);
+ALIAS_REGISTER(Register, kPtrComprCageBaseRegister, kRootRegister);
 #endif
 // Context pointer register.
 ALIAS_REGISTER(Register, cp, x27);
diff --git a/chromium/v8/src/codegen/assembler.cc b/chromium/v8/src/codegen/assembler.cc
index 95983705abd..bb80d366de3 100644
--- a/chromium/v8/src/codegen/assembler.cc
+++ b/chromium/v8/src/codegen/assembler.cc
@@ -69,7 +69,7 @@ AssemblerOptions AssemblerOptions::Default(Isolate* isolate) {
 #endif
   options.inline_offheap_trampolines &= !generating_embedded_builtin;
 #if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64
-  const base::AddressRegion& code_range = isolate->heap()->code_range();
+  const base::AddressRegion& code_range = isolate->heap()->code_region();
   DCHECK_IMPLIES(code_range.begin() != kNullAddress, !code_range.is_empty());
   options.code_range_start = code_range.begin();
 #endif
@@ -180,7 +180,6 @@ AssemblerBase::AssemblerBase(const AssemblerOptions& options,
     : buffer_(std::move(buffer)),
       options_(options),
       enabled_cpu_features_(0),
-      emit_debug_code_(FLAG_debug_code),
       predictable_code_size_(false),
       constant_pool_available_(false),
       jump_optimization_info_(nullptr) {
@@ -298,6 +297,7 @@ Handle<HeapObject> AssemblerBase::GetEmbeddedObject(
 
 
 int Assembler::WriteCodeComments() {
+  if (!FLAG_code_comments) return 0;
   CHECK_IMPLIES(code_comments_writer_.entry_count() > 0,
                 options().emit_code_comments);
   if (code_comments_writer_.entry_count() == 0) return 0;
diff --git a/chromium/v8/src/codegen/assembler.h b/chromium/v8/src/codegen/assembler.h
index 70669059664..98cca61a7c6 100644
--- a/chromium/v8/src/codegen/assembler.h
+++ b/chromium/v8/src/codegen/assembler.h
@@ -222,9 +222,6 @@ class V8_EXPORT_PRIVATE AssemblerBase : public Malloced {
 
   const AssemblerOptions& options() const { return options_; }
 
-  bool emit_debug_code() const { return emit_debug_code_; }
-  void set_emit_debug_code(bool value) { emit_debug_code_ = value; }
-
   bool predictable_code_size() const { return predictable_code_size_; }
   void set_predictable_code_size(bool value) { predictable_code_size_ = value; }
 
@@ -291,7 +288,10 @@ class V8_EXPORT_PRIVATE AssemblerBase : public Malloced {
 
   // Record an inline code comment that can be used by a disassembler.
   // Use --code-comments to enable.
-  void RecordComment(const char* msg) {
+  V8_INLINE void RecordComment(const char* msg) {
+    // Set explicit dependency on --code-comments for dead-code elimination in
+    // release builds.
+    if (!FLAG_code_comments) return;
     if (options().emit_code_comments) {
       code_comments_writer_.Add(pc_offset(), std::string(msg));
     }
@@ -346,7 +346,7 @@ class V8_EXPORT_PRIVATE AssemblerBase : public Malloced {
     DCHECK(!RelocInfo::IsNone(rmode));
     if (options().disable_reloc_info_for_patching) return false;
     if (RelocInfo::IsOnlyForSerializer(rmode) &&
-        !options().record_reloc_info_for_serialization && !emit_debug_code()) {
+        !options().record_reloc_info_for_serialization && !FLAG_debug_code) {
       return false;
     }
     return true;
@@ -378,7 +378,6 @@ class V8_EXPORT_PRIVATE AssemblerBase : public Malloced {
 
   const AssemblerOptions options_;
   uint64_t enabled_cpu_features_;
-  bool emit_debug_code_;
   bool predictable_code_size_;
 
   // Indicates whether the constant pool can be accessed, which is only possible
@@ -392,20 +391,6 @@ class V8_EXPORT_PRIVATE AssemblerBase : public Malloced {
   friend class ConstantPoolUnavailableScope;
 };
 
-// Avoids emitting debug code during the lifetime of this scope object.
-class V8_NODISCARD DontEmitDebugCodeScope {
- public:
-  explicit DontEmitDebugCodeScope(AssemblerBase* assembler)
-      : assembler_(assembler), old_value_(assembler->emit_debug_code()) {
-    assembler_->set_emit_debug_code(false);
-  }
-  ~DontEmitDebugCodeScope() { assembler_->set_emit_debug_code(old_value_); }
-
- private:
-  AssemblerBase* assembler_;
-  bool old_value_;
-};
-
 // Enable a specified feature within a scope.
 class V8_EXPORT_PRIVATE V8_NODISCARD CpuFeatureScope {
  public:
@@ -425,7 +410,7 @@ class V8_EXPORT_PRIVATE V8_NODISCARD CpuFeatureScope {
 #else
   CpuFeatureScope(AssemblerBase* assembler, CpuFeature f,
                   CheckPolicy check = kCheckSupported) {}
-  ~CpuFeatureScope() {  // NOLINT (modernize-use-equals-default)
+  ~CpuFeatureScope() {
     // Define a destructor to avoid unused variable warnings.
   }
 #endif
diff --git a/chromium/v8/src/codegen/bailout-reason.h b/chromium/v8/src/codegen/bailout-reason.h
index 57bbbca7230..e8afa74e168 100644
--- a/chromium/v8/src/codegen/bailout-reason.h
+++ b/chromium/v8/src/codegen/bailout-reason.h
@@ -24,6 +24,7 @@ namespace internal {
   V(kExpectedFeedbackVector, "Expected feedback vector")                       \
   V(kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry,                      \
     "The function_data field should be a BytecodeArray on interpreter entry")  \
+  V(kFpuTopIsNotZeroInDeoptimizer, "FPU TOP is not zero in deoptimizer")       \
   V(kInputStringTooLong, "Input string too long")                              \
   V(kInvalidBytecode, "Invalid bytecode")                                      \
   V(kInvalidBytecodeAdvance, "Cannot advance current bytecode, ")              \
diff --git a/chromium/v8/src/codegen/code-factory.cc b/chromium/v8/src/codegen/code-factory.cc
index ece8200023d..854969f8cb4 100644
--- a/chromium/v8/src/codegen/code-factory.cc
+++ b/chromium/v8/src/codegen/code-factory.cc
@@ -31,25 +31,35 @@ Handle<Code> CodeFactory::CEntry(Isolate* isolate, int result_size,
   const ArgvMode am = argv_mode;
   const bool be = builtin_exit_frame;
 
-  if (rs == 1 && sd == kDontSaveFPRegs && am == kArgvOnStack && !be) {
+  if (rs == 1 && sd == SaveFPRegsMode::kIgnore && am == ArgvMode::kStack &&
+      !be) {
     return CENTRY_CODE(Return1, DontSaveFPRegs, ArgvOnStack, NoBuiltinExit);
-  } else if (rs == 1 && sd == kDontSaveFPRegs && am == kArgvOnStack && be) {
+  } else if (rs == 1 && sd == SaveFPRegsMode::kIgnore &&
+             am == ArgvMode::kStack && be) {
     return CENTRY_CODE(Return1, DontSaveFPRegs, ArgvOnStack, BuiltinExit);
-  } else if (rs == 1 && sd == kDontSaveFPRegs && am == kArgvInRegister && !be) {
+  } else if (rs == 1 && sd == SaveFPRegsMode::kIgnore &&
+             am == ArgvMode::kRegister && !be) {
     return CENTRY_CODE(Return1, DontSaveFPRegs, ArgvInRegister, NoBuiltinExit);
-  } else if (rs == 1 && sd == kSaveFPRegs && am == kArgvOnStack && !be) {
+  } else if (rs == 1 && sd == SaveFPRegsMode::kSave && am == ArgvMode::kStack &&
+             !be) {
     return CENTRY_CODE(Return1, SaveFPRegs, ArgvOnStack, NoBuiltinExit);
-  } else if (rs == 1 && sd == kSaveFPRegs && am == kArgvOnStack && be) {
+  } else if (rs == 1 && sd == SaveFPRegsMode::kSave && am == ArgvMode::kStack &&
+             be) {
     return CENTRY_CODE(Return1, SaveFPRegs, ArgvOnStack, BuiltinExit);
-  } else if (rs == 2 && sd == kDontSaveFPRegs && am == kArgvOnStack && !be) {
+  } else if (rs == 2 && sd == SaveFPRegsMode::kIgnore &&
+             am == ArgvMode::kStack && !be) {
     return CENTRY_CODE(Return2, DontSaveFPRegs, ArgvOnStack, NoBuiltinExit);
-  } else if (rs == 2 && sd == kDontSaveFPRegs && am == kArgvOnStack && be) {
+  } else if (rs == 2 && sd == SaveFPRegsMode::kIgnore &&
+             am == ArgvMode::kStack && be) {
     return CENTRY_CODE(Return2, DontSaveFPRegs, ArgvOnStack, BuiltinExit);
-  } else if (rs == 2 && sd == kDontSaveFPRegs && am == kArgvInRegister && !be) {
+  } else if (rs == 2 && sd == SaveFPRegsMode::kIgnore &&
+             am == ArgvMode::kRegister && !be) {
     return CENTRY_CODE(Return2, DontSaveFPRegs, ArgvInRegister, NoBuiltinExit);
-  } else if (rs == 2 && sd == kSaveFPRegs && am == kArgvOnStack && !be) {
+  } else if (rs == 2 && sd == SaveFPRegsMode::kSave && am == ArgvMode::kStack &&
+             !be) {
     return CENTRY_CODE(Return2, SaveFPRegs, ArgvOnStack, NoBuiltinExit);
-  } else if (rs == 2 && sd == kSaveFPRegs && am == kArgvOnStack && be) {
+  } else if (rs == 2 && sd == SaveFPRegsMode::kSave && am == ArgvMode::kStack &&
+             be) {
     return CENTRY_CODE(Return2, SaveFPRegs, ArgvOnStack, BuiltinExit);
   }
 
@@ -70,7 +80,7 @@ Callable CodeFactory::CallApiCallback(Isolate* isolate) {
 
 // static
 Callable CodeFactory::LoadGlobalIC(Isolate* isolate, TypeofMode typeof_mode) {
-  return typeof_mode == NOT_INSIDE_TYPEOF
+  return typeof_mode == TypeofMode::kNotInside
              ? Builtins::CallableFor(isolate, Builtins::kLoadGlobalICTrampoline)
              : Builtins::CallableFor(
                    isolate, Builtins::kLoadGlobalICInsideTypeofTrampoline);
@@ -79,7 +89,7 @@ Callable CodeFactory::LoadGlobalIC(Isolate* isolate, TypeofMode typeof_mode) {
 // static
 Callable CodeFactory::LoadGlobalICInOptimizedCode(Isolate* isolate,
                                                   TypeofMode typeof_mode) {
-  return typeof_mode == NOT_INSIDE_TYPEOF
+  return typeof_mode == TypeofMode::kNotInside
              ? Builtins::CallableFor(isolate, Builtins::kLoadGlobalIC)
              : Builtins::CallableFor(isolate,
                                      Builtins::kLoadGlobalICInsideTypeof);
@@ -233,16 +243,6 @@ Callable CodeFactory::ResumeGenerator(Isolate* isolate) {
 }
 
 // static
-Callable CodeFactory::FrameDropperTrampoline(Isolate* isolate) {
-  return Builtins::CallableFor(isolate, Builtins::kFrameDropperTrampoline);
-}
-
-// static
-Callable CodeFactory::HandleDebuggerStatement(Isolate* isolate) {
-  return Builtins::CallableFor(isolate, Builtins::kHandleDebuggerStatement);
-}
-
-// static
 Callable CodeFactory::FastNewFunctionContext(Isolate* isolate,
                                              ScopeType scope_type) {
   switch (scope_type) {
@@ -388,8 +388,8 @@ Callable CodeFactory::InterpreterPushArgsThenConstruct(
 Callable CodeFactory::InterpreterCEntry(Isolate* isolate, int result_size) {
   // Note: If we ever use fpregs in the interpreter then we will need to
   // save fpregs too.
-  Handle<Code> code = CodeFactory::CEntry(isolate, result_size, kDontSaveFPRegs,
-                                          kArgvInRegister);
+  Handle<Code> code = CodeFactory::CEntry(
+      isolate, result_size, SaveFPRegsMode::kIgnore, ArgvMode::kRegister);
   if (result_size == 1) {
     return Callable(code, InterpreterCEntry1Descriptor{});
   } else {
diff --git a/chromium/v8/src/codegen/code-factory.h b/chromium/v8/src/codegen/code-factory.h
index aab29770453..e55de10533e 100644
--- a/chromium/v8/src/codegen/code-factory.h
+++ b/chromium/v8/src/codegen/code-factory.h
@@ -28,10 +28,10 @@ class V8_EXPORT_PRIVATE CodeFactory final {
   // is exported here.
   static Handle<Code> RuntimeCEntry(Isolate* isolate, int result_size = 1);
 
-  static Handle<Code> CEntry(Isolate* isolate, int result_size = 1,
-                             SaveFPRegsMode save_doubles = kDontSaveFPRegs,
-                             ArgvMode argv_mode = kArgvOnStack,
-                             bool builtin_exit_frame = false);
+  static Handle<Code> CEntry(
+      Isolate* isolate, int result_size = 1,
+      SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore,
+      ArgvMode argv_mode = ArgvMode::kStack, bool builtin_exit_frame = false);
 
   // Initial states for ICs.
   static Callable LoadGlobalIC(Isolate* isolate, TypeofMode typeof_mode);
@@ -49,9 +49,6 @@ class V8_EXPORT_PRIVATE CodeFactory final {
 
   static Callable ResumeGenerator(Isolate* isolate);
 
-  static Callable FrameDropperTrampoline(Isolate* isolate);
-  static Callable HandleDebuggerStatement(Isolate* isolate);
-
   static Callable BinaryOperation(Isolate* isolate, Operation op);
 
   static Callable ApiGetter(Isolate* isolate);
diff --git a/chromium/v8/src/codegen/code-stub-assembler.cc b/chromium/v8/src/codegen/code-stub-assembler.cc
index 0b039e40fac..5995a766d11 100644
--- a/chromium/v8/src/codegen/code-stub-assembler.cc
+++ b/chromium/v8/src/codegen/code-stub-assembler.cc
@@ -103,7 +103,7 @@ void CodeStubAssembler::Check(const BranchGenerator& branch,
                               std::initializer_list<ExtraNode> extra_nodes) {
   Label ok(this);
   Label not_ok(this, Label::kDeferred);
-  if (message != nullptr && FLAG_code_comments) {
+  if (message != nullptr) {
     Comment("[ Assert: ", message);
   } else {
     Comment("[ Assert");
@@ -1368,6 +1368,7 @@ TNode<HeapObject> CodeStubAssembler::AllocateInNewSpace(
 TNode<HeapObject> CodeStubAssembler::Allocate(TNode<IntPtrT> size_in_bytes,
                                               AllocationFlags flags) {
   Comment("Allocate");
+  if (FLAG_single_generation) flags |= kPretenured;
   bool const new_space = !(flags & kPretenured);
   bool const allow_large_objects = flags & kAllowLargeObjectAllocation;
   // For optimized allocations, we don't allow the allocation to happen in a
@@ -1574,8 +1575,8 @@ TNode<RawPtrT> CodeStubAssembler::LoadExternalPointerFromObject(
 
   TNode<UintPtrT> entry = Load<UintPtrT>(table, table_offset);
   if (external_pointer_tag != 0) {
-    TNode<UintPtrT> tag = UintPtrConstant(external_pointer_tag);
-    entry = UncheckedCast<UintPtrT>(WordXor(entry, tag));
+    TNode<UintPtrT> tag = UintPtrConstant(~external_pointer_tag);
+    entry = UncheckedCast<UintPtrT>(WordAnd(entry, tag));
   }
   return UncheckedCast<RawPtrT>(UncheckedCast<WordT>(entry));
 #else
@@ -1603,7 +1604,7 @@ void CodeStubAssembler::StoreExternalPointerToObject(
   TNode<UintPtrT> value = UncheckedCast<UintPtrT>(pointer);
   if (external_pointer_tag != 0) {
     TNode<UintPtrT> tag = UintPtrConstant(external_pointer_tag);
-    value = UncheckedCast<UintPtrT>(WordXor(pointer, tag));
+    value = UncheckedCast<UintPtrT>(WordOr(pointer, tag));
   }
   StoreNoWriteBarrier(MachineType::PointerRepresentation(), table, table_offset,
                       value);
@@ -1619,6 +1620,8 @@ TNode<Object> CodeStubAssembler::LoadFromParentFrame(int offset) {
 
 TNode<IntPtrT> CodeStubAssembler::LoadAndUntagObjectField(
     TNode<HeapObject> object, int offset) {
+  // Please use LoadMap(object) instead.
+  DCHECK_NE(offset, HeapObject::kMapOffset);
   if (SmiValuesAre32Bits()) {
 #if V8_TARGET_LITTLE_ENDIAN
     offset += 4;
@@ -1631,6 +1634,8 @@ TNode<IntPtrT> CodeStubAssembler::LoadAndUntagObjectField(
 
 TNode<Int32T> CodeStubAssembler::LoadAndUntagToWord32ObjectField(
     TNode<HeapObject> object, int offset) {
+  // Please use LoadMap(object) instead.
+  DCHECK_NE(offset, HeapObject::kMapOffset);
   if (SmiValuesAre32Bits()) {
 #if V8_TARGET_LITTLE_ENDIAN
     offset += 4;
@@ -1656,7 +1661,15 @@ TNode<Map> CodeStubAssembler::GetInstanceTypeMap(InstanceType instance_type) {
 }
 
 TNode<Map> CodeStubAssembler::LoadMap(TNode<HeapObject> object) {
-  return LoadObjectField<Map>(object, HeapObject::kMapOffset);
+  TNode<Map> map = LoadObjectField<Map>(object, HeapObject::kMapOffset);
+#ifdef V8_MAP_PACKING
+  // Check the loaded map is unpacked. i.e. the lowest two bits != 0b10
+  CSA_ASSERT(this,
+             WordNotEqual(WordAnd(BitcastTaggedToWord(map),
+                                  IntPtrConstant(Internals::kMapWordXorMask)),
+                          IntPtrConstant(Internals::kMapWordSignature)));
+#endif
+  return map;
 }
 
 TNode<Uint16T> CodeStubAssembler::LoadInstanceType(TNode<HeapObject> object) {
@@ -2033,6 +2046,13 @@ void CodeStubAssembler::DispatchMaybeObject(TNode<MaybeObject> maybe_object,
   Goto(if_strong);
 }
 
+void CodeStubAssembler::AssertHasValidMap(TNode<HeapObject> object) {
+#ifdef V8_MAP_PACKING
+  // Test if the map is an unpacked and valid map
+  CSA_ASSERT(this, IsMap(LoadMap(object)));
+#endif
+}
+
 TNode<BoolT> CodeStubAssembler::IsStrong(TNode<MaybeObject> value) {
   return Word32Equal(Word32And(TruncateIntPtrToInt32(
                                    BitcastTaggedToWordForTagAndSmiBits(value)),
@@ -2943,12 +2963,14 @@ void CodeStubAssembler::StoreObjectField(TNode<HeapObject> object,
 
 void CodeStubAssembler::UnsafeStoreObjectFieldNoWriteBarrier(
     TNode<HeapObject> object, int offset, TNode<Object> value) {
+  DCHECK_NE(HeapObject::kMapOffset, offset);  // Use StoreMap instead.
   OptimizedStoreFieldUnsafeNoWriteBarrier(MachineRepresentation::kTagged,
                                           object, offset, value);
 }
 
 void CodeStubAssembler::StoreMap(TNode<HeapObject> object, TNode<Map> map) {
   OptimizedStoreMap(object, map);
+  AssertHasValidMap(object);
 }
 
 void CodeStubAssembler::StoreMapNoWriteBarrier(TNode<HeapObject> object,
@@ -2958,16 +2980,19 @@ void CodeStubAssembler::StoreMapNoWriteBarrier(TNode<HeapObject> object,
 
 void CodeStubAssembler::StoreMapNoWriteBarrier(TNode<HeapObject> object,
                                                TNode<Map> map) {
-  OptimizedStoreFieldAssertNoWriteBarrier(MachineRepresentation::kTaggedPointer,
-                                          object, HeapObject::kMapOffset, map);
+  OptimizedStoreMap(object, map);
+  AssertHasValidMap(object);
 }
 
 void CodeStubAssembler::StoreObjectFieldRoot(TNode<HeapObject> object,
                                              int offset, RootIndex root_index) {
-  if (RootsTable::IsImmortalImmovable(root_index)) {
-    StoreObjectFieldNoWriteBarrier(object, offset, LoadRoot(root_index));
+  TNode<Object> root = LoadRoot(root_index);
+  if (offset == HeapObject::kMapOffset) {
+    StoreMap(object, CAST(root));
+  } else if (RootsTable::IsImmortalImmovable(root_index)) {
+    StoreObjectFieldNoWriteBarrier(object, offset, root);
   } else {
-    StoreObjectField(object, offset, LoadRoot(root_index));
+    StoreObjectField(object, offset, root);
   }
 }
 
@@ -4762,7 +4787,11 @@ void CodeStubAssembler::MoveElements(ElementsKind kind,
                                      TNode<IntPtrT> length) {
   Label finished(this);
   Label needs_barrier(this);
+#ifdef V8_DISABLE_WRITE_BARRIERS
+  const bool needs_barrier_check = false;
+#else
   const bool needs_barrier_check = !IsDoubleElementsKind(kind);
+#endif  // V8_DISABLE_WRITE_BARRIERS
 
   DCHECK(IsFastElementsKind(kind));
   CSA_ASSERT(this, IsFixedArrayWithKind(elements, kind));
@@ -4847,7 +4876,11 @@ void CodeStubAssembler::CopyElements(ElementsKind kind,
                                      WriteBarrierMode write_barrier) {
   Label finished(this);
   Label needs_barrier(this);
+#ifdef V8_DISABLE_WRITE_BARRIERS
+  const bool needs_barrier_check = false;
+#else
   const bool needs_barrier_check = !IsDoubleElementsKind(kind);
+#endif  // V8_DISABLE_WRITE_BARRIERS
 
   DCHECK(IsFastElementsKind(kind));
   CSA_ASSERT(this, IsFixedArrayWithKind(dst_elements, kind));
@@ -5294,6 +5327,10 @@ TNode<FixedArrayBase> CodeStubAssembler::GrowElementsCapacity(
   return new_elements;
 }
 
+template TNode<FixedArrayBase> CodeStubAssembler::GrowElementsCapacity<IntPtrT>(
+    TNode<HeapObject>, TNode<FixedArrayBase>, ElementsKind, ElementsKind,
+    TNode<IntPtrT>, TNode<IntPtrT>, compiler::CodeAssemblerLabel*);
+
 void CodeStubAssembler::InitializeAllocationMemento(
     TNode<HeapObject> base, TNode<IntPtrT> base_allocation_size,
     TNode<AllocationSite> allocation_site) {
@@ -6036,6 +6073,13 @@ TNode<BoolT> CodeStubAssembler::IsNoElementsProtectorCellInvalid() {
   return TaggedEqual(cell_value, invalid);
 }
 
+TNode<BoolT> CodeStubAssembler::IsMegaDOMProtectorCellInvalid() {
+  TNode<Smi> invalid = SmiConstant(Protectors::kProtectorInvalid);
+  TNode<PropertyCell> cell = MegaDOMProtectorConstant();
+  TNode<Object> cell_value = LoadObjectField(cell, PropertyCell::kValueOffset);
+  return TaggedEqual(cell_value, invalid);
+}
+
 TNode<BoolT> CodeStubAssembler::IsArrayIteratorProtectorCellInvalid() {
   TNode<Smi> invalid = SmiConstant(Protectors::kProtectorInvalid);
   TNode<PropertyCell> cell = ArrayIteratorProtectorConstant();
@@ -6285,14 +6329,27 @@ TNode<BoolT> CodeStubAssembler::IsJSObjectInstanceType(
                                  Int32Constant(FIRST_JS_OBJECT_TYPE));
 }
 
+TNode<BoolT> CodeStubAssembler::IsJSApiObjectInstanceType(
+    TNode<Int32T> instance_type) {
+  return InstanceTypeEqual(instance_type, JS_API_OBJECT_TYPE);
+}
+
 TNode<BoolT> CodeStubAssembler::IsJSObjectMap(TNode<Map> map) {
   return IsJSObjectInstanceType(LoadMapInstanceType(map));
 }
 
+TNode<BoolT> CodeStubAssembler::IsJSApiObjectMap(TNode<Map> map) {
+  return IsJSApiObjectInstanceType(LoadMapInstanceType(map));
+}
+
 TNode<BoolT> CodeStubAssembler::IsJSObject(TNode<HeapObject> object) {
   return IsJSObjectMap(LoadMap(object));
 }
 
+TNode<BoolT> CodeStubAssembler::IsJSApiObject(TNode<HeapObject> object) {
+  return IsJSApiObjectMap(LoadMap(object));
+}
+
 TNode<BoolT> CodeStubAssembler::IsJSFinalizationRegistryMap(TNode<Map> map) {
   return InstanceTypeEqual(LoadMapInstanceType(map),
                            JS_FINALIZATION_REGISTRY_TYPE);
@@ -7672,15 +7729,25 @@ TNode<Object> CodeStubAssembler::OrdinaryToPrimitive(
 TNode<Uint32T> CodeStubAssembler::DecodeWord32(TNode<Word32T> word32,
                                                uint32_t shift, uint32_t mask) {
   DCHECK_EQ((mask >> shift) << shift, mask);
-  return Unsigned(Word32And(Word32Shr(word32, static_cast<int>(shift)),
-                            Int32Constant(mask >> shift)));
+  if ((std::numeric_limits<uint32_t>::max() >> shift) ==
+      ((std::numeric_limits<uint32_t>::max() & mask) >> shift)) {
+    return Unsigned(Word32Shr(word32, static_cast<int>(shift)));
+  } else {
+    return Unsigned(Word32And(Word32Shr(word32, static_cast<int>(shift)),
+                              Int32Constant(mask >> shift)));
+  }
 }
 
 TNode<UintPtrT> CodeStubAssembler::DecodeWord(TNode<WordT> word, uint32_t shift,
                                               uintptr_t mask) {
   DCHECK_EQ((mask >> shift) << shift, mask);
-  return Unsigned(WordAnd(WordShr(word, static_cast<int>(shift)),
-                          IntPtrConstant(mask >> shift)));
+  if ((std::numeric_limits<uintptr_t>::max() >> shift) ==
+      ((std::numeric_limits<uintptr_t>::max() & mask) >> shift)) {
+    return Unsigned(WordShr(word, static_cast<int>(shift)));
+  } else {
+    return Unsigned(WordAnd(WordShr(word, static_cast<int>(shift)),
+                            IntPtrConstant(mask >> shift)));
+  }
 }
 
 TNode<Word32T> CodeStubAssembler::UpdateWord32(TNode<Word32T> word,
@@ -8871,9 +8938,9 @@ void CodeStubAssembler::ForEachEnumerableOwnProperty(
           {
             Label slow_load(this, Label::kDeferred);
 
-            var_value = CallGetterIfAccessor(var_value.value(), object,
-                                             var_details.value(), context,
-                                             object, &slow_load, kCallJSGetter);
+            var_value = CallGetterIfAccessor(
+                var_value.value(), object, var_details.value(), context, object,
+                next_key, &slow_load, kCallJSGetter);
             Goto(&callback);
 
             BIND(&slow_load);
@@ -9325,8 +9392,8 @@ template void CodeStubAssembler::LoadPropertyFromDictionary(
 // result of the getter call.
 TNode<Object> CodeStubAssembler::CallGetterIfAccessor(
     TNode<Object> value, TNode<HeapObject> holder, TNode<Uint32T> details,
-    TNode<Context> context, TNode<Object> receiver, Label* if_bailout,
-    GetOwnPropertyMode mode) {
+    TNode<Context> context, TNode<Object> receiver, TNode<Object> name,
+    Label* if_bailout, GetOwnPropertyMode mode) {
   TVARIABLE(Object, var_value, value);
   Label done(this), if_accessor_info(this, Label::kDeferred);
 
@@ -9354,13 +9421,16 @@ TNode<Object> CodeStubAssembler::CallGetterIfAccessor(
 
       BIND(&if_callable);
       {
-        // Call the accessor.
+        // Call the accessor. No need to check side-effect mode here, since it
+        // will be checked later in DebugOnFunctionCall.
         var_value = Call(context, getter, receiver);
         Goto(&done);
       }
 
       BIND(&if_function_template_info);
       {
+        Label runtime(this, Label::kDeferred);
+        GotoIf(IsSideEffectFreeDebuggingActive(), &runtime);
         TNode<HeapObject> cached_property_name = LoadObjectField<HeapObject>(
             getter, FunctionTemplateInfo::kCachedPropertyNameOffset);
         GotoIfNot(IsTheHole(cached_property_name), if_bailout);
@@ -9371,6 +9441,13 @@ TNode<Object> CodeStubAssembler::CallGetterIfAccessor(
             Builtins::kCallFunctionTemplate_CheckAccessAndCompatibleReceiver,
             creation_context, getter, IntPtrConstant(0), receiver);
         Goto(&done);
+
+        BIND(&runtime);
+        {
+          var_value = CallRuntime(Runtime::kGetProperty, context, holder, name,
+                                  receiver);
+          Goto(&done);
+        }
       }
     } else {
       Goto(&done);
@@ -9505,7 +9582,7 @@ void CodeStubAssembler::TryGetOwnProperty(
     }
     TNode<Object> value =
         CallGetterIfAccessor(var_value->value(), object, var_details->value(),
-                             context, receiver, if_bailout, mode);
+                             context, receiver, unique_name, if_bailout, mode);
     *var_value = value;
     Goto(if_found_value);
   }
@@ -9554,6 +9631,7 @@ void CodeStubAssembler::TryLookupElement(
       BIGUINT64_ELEMENTS,
       BIGINT64_ELEMENTS,
   };
+  // TODO(v8:11111): Support RAB / GSAB.
   Label* labels[] = {
       &if_isobjectorsmi, &if_isobjectorsmi, &if_isobjectorsmi,
       &if_isobjectorsmi, &if_isobjectorsmi, &if_isobjectorsmi,
@@ -10811,6 +10889,12 @@ void CodeStubAssembler::EmitElementStore(
     TNode<Context> context, TVariable<Object>* maybe_converted_value) {
   CSA_ASSERT(this, Word32BinaryNot(IsJSProxy(object)));
 
+  // TODO(v8:11111): Fast path for RAB / GSAB backed TypedArrays.
+  if (IsRabGsabTypedArrayElementsKind(elements_kind)) {
+    GotoIf(Int32TrueConstant(), bailout);
+    return;
+  }
+
   TNode<FixedArrayBase> elements = LoadElements(object);
   if (!(IsSmiOrObjectElementsKind(elements_kind) ||
         IsSealedElementsKind(elements_kind) ||
@@ -11057,6 +11141,8 @@ void CodeStubAssembler::TrapAllocationMemento(TNode<JSObject> object,
 
   // Bail out if the object is not in new space.
   TNode<IntPtrT> object_word = BitcastTaggedToWord(object);
+  // TODO(v8:11641): Skip TrapAllocationMemento when allocation-site
+  // tracking is disabled.
   TNode<IntPtrT> object_page = PageFromAddress(object_word);
   {
     TNode<IntPtrT> page_flags =
@@ -11102,15 +11188,19 @@ void CodeStubAssembler::TrapAllocationMemento(TNode<JSObject> object,
   // Memento map check.
   BIND(&map_check);
   {
-    TNode<Object> memento_map = LoadObjectField(object, kMementoMapOffset);
-    Branch(TaggedEqual(memento_map, AllocationMementoMapConstant()),
-           memento_found, &no_memento_found);
+    TNode<AnyTaggedT> maybe_mapword =
+        LoadObjectField(object, kMementoMapOffset);
+    TNode<AnyTaggedT> memento_mapword =
+        LoadRootMapWord(RootIndex::kAllocationMementoMap);
+    Branch(TaggedEqual(maybe_mapword, memento_mapword), memento_found,
+           &no_memento_found);
   }
   BIND(&no_memento_found);
   Comment("] TrapAllocationMemento");
 }
 
 TNode<IntPtrT> CodeStubAssembler::PageFromAddress(TNode<IntPtrT> address) {
+  if (FLAG_enable_third_party_heap) Unreachable();
   return WordAnd(address, IntPtrConstant(~kPageAlignmentMask));
 }
 
@@ -11323,7 +11413,12 @@ void CodeStubAssembler::InitializeFieldsWithRoot(TNode<HeapObject> object,
   CSA_SLOW_ASSERT(this, TaggedIsNotSmi(object));
   start_offset = IntPtrAdd(start_offset, IntPtrConstant(-kHeapObjectTag));
   end_offset = IntPtrAdd(end_offset, IntPtrConstant(-kHeapObjectTag));
-  TNode<Object> root_value = LoadRoot(root_index);
+  TNode<AnyTaggedT> root_value;
+  if (root_index == RootIndex::kOnePointerFillerMap) {
+    root_value = LoadRootMapWord(root_index);
+  } else {
+    root_value = LoadRoot(root_index);
+  }
   BuildFastLoop<IntPtrT>(
       end_offset, start_offset,
       [=](TNode<IntPtrT> current) {
@@ -13597,6 +13692,149 @@ TNode<UintPtrT> CodeStubAssembler::LoadJSTypedArrayLength(
   return LoadObjectField<UintPtrT>(typed_array, JSTypedArray::kLengthOffset);
 }
 
+// ES #sec-integerindexedobjectlength
+TNode<UintPtrT> CodeStubAssembler::LoadVariableLengthJSTypedArrayLength(
+    TNode<JSTypedArray> array, TNode<JSArrayBuffer> buffer, Label* miss) {
+  Label is_gsab(this), is_rab(this), end(this);
+  TVARIABLE(UintPtrT, result);
+
+  Branch(IsSharedArrayBuffer(buffer), &is_gsab, &is_rab);
+  BIND(&is_gsab);
+  {
+    // Non-length-tracking GSAB-backed TypedArrays shouldn't end up here.
+    CSA_ASSERT(this, IsLengthTrackingTypedArray(array));
+    // Read the byte length from the BackingStore.
+    const TNode<ExternalReference> length_function = ExternalConstant(
+        ExternalReference::length_tracking_gsab_backed_typed_array_length());
+    TNode<ExternalReference> isolate_ptr =
+        ExternalConstant(ExternalReference::isolate_address(isolate()));
+    result = UncheckedCast<UintPtrT>(
+        CallCFunction(length_function, MachineType::UintPtr(),
+                      std::make_pair(MachineType::Pointer(), isolate_ptr),
+                      std::make_pair(MachineType::AnyTagged(), array)));
+    Goto(&end);
+  }
+
+  BIND(&is_rab);
+  {
+    GotoIf(IsDetachedBuffer(buffer), miss);
+
+    TNode<UintPtrT> buffer_byte_length = LoadJSArrayBufferByteLength(buffer);
+    TNode<UintPtrT> array_byte_offset = LoadJSArrayBufferViewByteOffset(array);
+
+    Label is_length_tracking(this), not_length_tracking(this);
+    Branch(IsLengthTrackingTypedArray(array), &is_length_tracking,
+           &not_length_tracking);
+
+    BIND(&is_length_tracking);
+    {
+      // The backing RAB might have been shrunk so that the start of the
+      // TypedArray is already out of bounds.
+      GotoIfNot(UintPtrLessThanOrEqual(array_byte_offset, buffer_byte_length),
+                miss);
+      // length = (buffer_byte_length - byte_offset) / element_size
+      // Conversion to signed is OK since buffer_byte_length <
+      // JSArrayBuffer::kMaxByteLength.
+      TNode<IntPtrT> element_size =
+          RabGsabElementsKindToElementByteSize(LoadElementsKind(array));
+      TNode<IntPtrT> length =
+          IntPtrDiv(Signed(UintPtrSub(buffer_byte_length, array_byte_offset)),
+                    element_size);
+      result = Unsigned(length);
+      Goto(&end);
+    }
+
+    BIND(&not_length_tracking);
+    {
+      // Check if the backing RAB has shrunk so that the buffer is out of
+      // bounds.
+      TNode<UintPtrT> array_byte_length =
+          LoadJSArrayBufferViewByteLength(array);
+      GotoIfNot(UintPtrGreaterThanOrEqual(
+                    buffer_byte_length,
+                    UintPtrAdd(array_byte_offset, array_byte_length)),
+                miss);
+      result = LoadJSTypedArrayLength(array);
+      Goto(&end);
+    }
+  }
+  BIND(&end);
+  return result.value();
+}
+
+// ES #sec-integerindexedobjectbytelength
+TNode<UintPtrT> CodeStubAssembler::LoadVariableLengthJSTypedArrayByteLength(
+    TNode<Context> context, TNode<JSTypedArray> array,
+    TNode<JSArrayBuffer> buffer) {
+  Label miss(this), end(this);
+  TVARIABLE(UintPtrT, result);
+
+  TNode<UintPtrT> length =
+      LoadVariableLengthJSTypedArrayLength(array, buffer, &miss);
+  TNode<IntPtrT> element_size =
+      RabGsabElementsKindToElementByteSize(LoadElementsKind(array));
+  // Conversion to signed is OK since length < JSArrayBuffer::kMaxByteLength.
+  TNode<IntPtrT> byte_length = IntPtrMul(Signed(length), element_size);
+  result = Unsigned(byte_length);
+  Goto(&end);
+  BIND(&miss);
+  {
+    result = UintPtrConstant(0);
+    Goto(&end);
+  }
+  BIND(&end);
+  return result.value();
+}
+
+TNode<IntPtrT> CodeStubAssembler::RabGsabElementsKindToElementByteSize(
+    TNode<Int32T> elements_kind) {
+  TVARIABLE(IntPtrT, result);
+  Label elements_8(this), elements_16(this), elements_32(this),
+      elements_64(this), not_found(this), end(this);
+  int32_t elements_kinds[] = {
+      RAB_GSAB_UINT8_ELEMENTS,    RAB_GSAB_UINT8_CLAMPED_ELEMENTS,
+      RAB_GSAB_INT8_ELEMENTS,     RAB_GSAB_UINT16_ELEMENTS,
+      RAB_GSAB_INT16_ELEMENTS,    RAB_GSAB_UINT32_ELEMENTS,
+      RAB_GSAB_INT32_ELEMENTS,    RAB_GSAB_FLOAT32_ELEMENTS,
+      RAB_GSAB_FLOAT64_ELEMENTS,  RAB_GSAB_BIGINT64_ELEMENTS,
+      RAB_GSAB_BIGUINT64_ELEMENTS};
+  Label* elements_kind_labels[] = {&elements_8,  &elements_8,  &elements_8,
+                                   &elements_16, &elements_16, &elements_32,
+                                   &elements_32, &elements_32, &elements_64,
+                                   &elements_64, &elements_64};
+  const size_t kTypedElementsKindCount =
+      LAST_RAB_GSAB_FIXED_TYPED_ARRAY_ELEMENTS_KIND -
+      FIRST_RAB_GSAB_FIXED_TYPED_ARRAY_ELEMENTS_KIND + 1;
+  DCHECK_EQ(kTypedElementsKindCount, arraysize(elements_kinds));
+  DCHECK_EQ(kTypedElementsKindCount, arraysize(elements_kind_labels));
+  Switch(elements_kind, &not_found, elements_kinds, elements_kind_labels,
+         kTypedElementsKindCount);
+  BIND(&elements_8);
+  {
+    result = IntPtrConstant(1);
+    Goto(&end);
+  }
+  BIND(&elements_16);
+  {
+    result = IntPtrConstant(2);
+    Goto(&end);
+  }
+  BIND(&elements_32);
+  {
+    result = IntPtrConstant(4);
+    Goto(&end);
+  }
+  BIND(&elements_64);
+  {
+    result = IntPtrConstant(8);
+    Goto(&end);
+  }
+  BIND(&not_found);
+  { Unreachable(); }
+  BIND(&end);
+  return result.value();
+}
+
 TNode<JSArrayBuffer> CodeStubAssembler::GetTypedArrayBuffer(
     TNode<Context> context, TNode<JSTypedArray> array) {
   Label call_runtime(this), done(this);
@@ -13799,10 +14037,15 @@ TNode<BoolT> CodeStubAssembler::IsDebugActive() {
   return Word32NotEqual(is_debug_active, Int32Constant(0));
 }
 
-TNode<BoolT> CodeStubAssembler::IsPromiseHookEnabled() {
-  const TNode<RawPtrT> promise_hook = Load<RawPtrT>(
-      ExternalConstant(ExternalReference::promise_hook_address(isolate())));
-  return WordNotEqual(promise_hook, IntPtrConstant(0));
+TNode<BoolT> CodeStubAssembler::IsSideEffectFreeDebuggingActive() {
+  TNode<Uint8T> debug_execution_mode = Load<Uint8T>(ExternalConstant(
+      ExternalReference::debug_execution_mode_address(isolate())));
+
+  TNode<BoolT> is_active =
+      Word32Equal(debug_execution_mode,
+                  Int32Constant(DebugInfo::ExecutionMode::kSideEffects));
+
+  return is_active;
 }
 
 TNode<BoolT> CodeStubAssembler::HasAsyncEventDelegate() {
@@ -13811,23 +14054,40 @@ TNode<BoolT> CodeStubAssembler::HasAsyncEventDelegate() {
   return WordNotEqual(async_event_delegate, IntPtrConstant(0));
 }
 
-TNode<BoolT> CodeStubAssembler::IsPromiseHookEnabledOrHasAsyncEventDelegate() {
-  const TNode<Uint8T> promise_hook_or_async_event_delegate =
-      Load<Uint8T>(ExternalConstant(
-          ExternalReference::promise_hook_or_async_event_delegate_address(
-              isolate())));
-  return Word32NotEqual(promise_hook_or_async_event_delegate, Int32Constant(0));
+TNode<Uint32T> CodeStubAssembler::PromiseHookFlags() {
+  return Load<Uint32T>(ExternalConstant(
+    ExternalReference::promise_hook_flags_address(isolate())));
+}
+
+TNode<BoolT> CodeStubAssembler::IsAnyPromiseHookEnabled(TNode<Uint32T> flags) {
+  uint32_t mask = Isolate::PromiseHookFields::HasContextPromiseHook::kMask |
+                  Isolate::PromiseHookFields::HasIsolatePromiseHook::kMask;
+  return IsSetWord32(flags, mask);
+}
+
+TNode<BoolT> CodeStubAssembler::IsContextPromiseHookEnabled(
+    TNode<Uint32T> flags) {
+  return IsSetWord32<Isolate::PromiseHookFields::HasContextPromiseHook>(flags);
 }
 
 TNode<BoolT> CodeStubAssembler::
-    IsPromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate() {
-  const TNode<Uint8T> promise_hook_or_debug_is_active_or_async_event_delegate =
-      Load<Uint8T>(ExternalConstant(
-          ExternalReference::
-              promise_hook_or_debug_is_active_or_async_event_delegate_address(
-                  isolate())));
-  return Word32NotEqual(promise_hook_or_debug_is_active_or_async_event_delegate,
-                        Int32Constant(0));
+    IsIsolatePromiseHookEnabledOrHasAsyncEventDelegate(TNode<Uint32T> flags) {
+  uint32_t mask = Isolate::PromiseHookFields::HasIsolatePromiseHook::kMask |
+                  Isolate::PromiseHookFields::HasAsyncEventDelegate::kMask;
+  return IsSetWord32(flags, mask);
+}
+
+TNode<BoolT> CodeStubAssembler::
+    IsIsolatePromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate(
+        TNode<Uint32T> flags) {
+  uint32_t mask = Isolate::PromiseHookFields::HasIsolatePromiseHook::kMask |
+                  Isolate::PromiseHookFields::HasAsyncEventDelegate::kMask |
+                  Isolate::PromiseHookFields::IsDebugActive::kMask;
+  return IsSetWord32(flags, mask);
+}
+
+TNode<BoolT> CodeStubAssembler::NeedsAnyPromiseHooks(TNode<Uint32T> flags) {
+  return Word32NotEqual(flags, Int32Constant(0));
 }
 
 TNode<Code> CodeStubAssembler::LoadBuiltin(TNode<Smi> builtin_id) {
diff --git a/chromium/v8/src/codegen/code-stub-assembler.h b/chromium/v8/src/codegen/code-stub-assembler.h
index 72b8fbc8a80..9b54b5014e3 100644
--- a/chromium/v8/src/codegen/code-stub-assembler.h
+++ b/chromium/v8/src/codegen/code-stub-assembler.h
@@ -67,6 +67,7 @@ enum class PrimitiveType { kBoolean, kNumber, kString, kSymbol };
     AsyncIteratorValueUnwrapSharedFun)                                         \
   V(MapIteratorProtector, map_iterator_protector, MapIteratorProtector)        \
   V(NoElementsProtector, no_elements_protector, NoElementsProtector)           \
+  V(MegaDOMProtector, mega_dom_protector, MegaDOMProtector)                    \
   V(NumberStringCache, number_string_cache, NumberStringCache)                 \
   V(PromiseAllResolveElementSharedFun, promise_all_resolve_element_shared_fun, \
     PromiseAllResolveElementSharedFun)                                         \
@@ -157,6 +158,7 @@ enum class PrimitiveType { kBoolean, kNumber, kString, kSymbol };
   V(ManyClosuresCellMap, many_closures_cell_map, ManyClosuresCellMap)        \
   V(match_symbol, match_symbol, MatchSymbol)                                 \
   V(megamorphic_symbol, megamorphic_symbol, MegamorphicSymbol)               \
+  V(mega_dom_symbol, mega_dom_symbol, MegaDOMSymbol)                         \
   V(message_string, message_string, MessageString)                           \
   V(minus_Infinity_string, minus_Infinity_string, MinusInfinityString)       \
   V(MinusZeroValue, minus_zero_value, MinusZero)                             \
@@ -1088,7 +1090,19 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   }
   // Load a field from an object on the heap.
   template <class T, typename std::enable_if<
-                         std::is_convertible<TNode<T>, TNode<Object>>::value,
+                         std::is_convertible<TNode<T>, TNode<Object>>::value &&
+                             std::is_base_of<T, Map>::value,
+                         int>::type = 0>
+  TNode<T> LoadObjectField(TNode<HeapObject> object, int offset) {
+    const MachineType machine_type = offset == HeapObject::kMapOffset
+                                         ? MachineType::MapInHeader()
+                                         : MachineTypeOf<T>::value;
+    return CAST(LoadFromObject(machine_type, object,
+                               IntPtrConstant(offset - kHeapObjectTag)));
+  }
+  template <class T, typename std::enable_if<
+                         std::is_convertible<TNode<T>, TNode<Object>>::value &&
+                             !std::is_base_of<T, Map>::value,
                          int>::type = 0>
   TNode<T> LoadObjectField(TNode<HeapObject> object, int offset) {
     return CAST(LoadFromObject(MachineTypeOf<T>::value, object,
@@ -1163,6 +1177,12 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
                          std::is_convertible<TNode<T>, TNode<Object>>::value,
                          int>::type = 0>
   TNode<T> LoadReference(Reference reference) {
+    if (IsMapOffsetConstant(reference.offset)) {
+      TNode<Map> map = LoadMap(CAST(reference.object));
+      DCHECK((std::is_base_of<T, Map>::value));
+      return ReinterpretCast<T>(map);
+    }
+
     TNode<IntPtrT> offset =
         IntPtrSub(reference.offset, IntPtrConstant(kHeapObjectTag));
     CSA_ASSERT(this, TaggedIsNotSmi(reference.object));
@@ -1175,6 +1195,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
                     std::is_same<T, MaybeObject>::value,
                 int>::type = 0>
   TNode<T> LoadReference(Reference reference) {
+    DCHECK(!IsMapOffsetConstant(reference.offset));
     TNode<IntPtrT> offset =
         IntPtrSub(reference.offset, IntPtrConstant(kHeapObjectTag));
     return UncheckedCast<T>(
@@ -1185,6 +1206,10 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
                              std::is_same<T, MaybeObject>::value,
                          int>::type = 0>
   void StoreReference(Reference reference, TNode<T> value) {
+    if (IsMapOffsetConstant(reference.offset)) {
+      DCHECK((std::is_base_of<T, Map>::value));
+      return StoreMap(CAST(reference.object), ReinterpretCast<Map>(value));
+    }
     MachineRepresentation rep = MachineRepresentationOf<T>::value;
     StoreToObjectWriteBarrier write_barrier = StoreToObjectWriteBarrier::kFull;
     if (std::is_same<T, Smi>::value) {
@@ -1201,6 +1226,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
                          std::is_convertible<TNode<T>, TNode<UntaggedT>>::value,
                          int>::type = 0>
   void StoreReference(Reference reference, TNode<T> value) {
+    DCHECK(!IsMapOffsetConstant(reference.offset));
     TNode<IntPtrT> offset =
         IntPtrSub(reference.offset, IntPtrConstant(kHeapObjectTag));
     StoreToObject(MachineRepresentationOf<T>::value, reference.object, offset,
@@ -2346,6 +2372,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   // JSProxy or an object with interceptors.
   TNode<BoolT> InstanceTypeEqual(TNode<Int32T> instance_type, int type);
   TNode<BoolT> IsNoElementsProtectorCellInvalid();
+  TNode<BoolT> IsMegaDOMProtectorCellInvalid();
   TNode<BoolT> IsArrayIteratorProtectorCellInvalid();
   TNode<BoolT> IsBigIntInstanceType(TNode<Int32T> instance_type);
   TNode<BoolT> IsBigInt(TNode<HeapObject> object);
@@ -2395,6 +2422,9 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   TNode<BoolT> IsJSObjectInstanceType(TNode<Int32T> instance_type);
   TNode<BoolT> IsJSObjectMap(TNode<Map> map);
   TNode<BoolT> IsJSObject(TNode<HeapObject> object);
+  TNode<BoolT> IsJSApiObjectInstanceType(TNode<Int32T> instance_type);
+  TNode<BoolT> IsJSApiObjectMap(TNode<Map> map);
+  TNode<BoolT> IsJSApiObject(TNode<HeapObject> object);
   TNode<BoolT> IsJSFinalizationRegistryMap(TNode<Map> map);
   TNode<BoolT> IsJSFinalizationRegistry(TNode<HeapObject> object);
   TNode<BoolT> IsJSPromiseMap(TNode<Map> map);
@@ -3451,6 +3481,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
 
   // Debug helpers
   TNode<BoolT> IsDebugActive();
+  TNode<BoolT> IsSideEffectFreeDebuggingActive();
 
   // JSArrayBuffer helpers
   TNode<RawPtrT> LoadJSArrayBufferBackingStorePtr(
@@ -3464,6 +3495,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
       TNode<JSArrayBufferView> array_buffer_view);
   TNode<UintPtrT> LoadJSArrayBufferViewByteLength(
       TNode<JSArrayBufferView> array_buffer_view);
+
   TNode<UintPtrT> LoadJSArrayBufferViewByteOffset(
       TNode<JSArrayBufferView> array_buffer_view);
   void ThrowIfArrayBufferViewBufferIsDetached(
@@ -3472,6 +3504,17 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
 
   // JSTypedArray helpers
   TNode<UintPtrT> LoadJSTypedArrayLength(TNode<JSTypedArray> typed_array);
+  // Helper for length tracking JSTypedArrays and JSTypedArrays backed by
+  // ResizableArrayBuffer.
+  TNode<UintPtrT> LoadVariableLengthJSTypedArrayLength(
+      TNode<JSTypedArray> array, TNode<JSArrayBuffer> buffer, Label* miss);
+  // Helper for length tracking JSTypedArrays and JSTypedArrays backed by
+  // ResizableArrayBuffer.
+  TNode<UintPtrT> LoadVariableLengthJSTypedArrayByteLength(
+      TNode<Context> context, TNode<JSTypedArray> array,
+      TNode<JSArrayBuffer> buffer);
+  TNode<IntPtrT> RabGsabElementsKindToElementByteSize(
+      TNode<Int32T> elementsKind);
   TNode<RawPtrT> LoadJSTypedArrayDataPtr(TNode<JSTypedArray> typed_array);
   TNode<JSArrayBuffer> GetTypedArrayBuffer(TNode<Context> context,
                                            TNode<JSTypedArray> array);
@@ -3504,10 +3547,35 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
       TNode<Context> context);
 
   // Promise helpers
-  TNode<BoolT> IsPromiseHookEnabled();
+  TNode<Uint32T> PromiseHookFlags();
   TNode<BoolT> HasAsyncEventDelegate();
-  TNode<BoolT> IsPromiseHookEnabledOrHasAsyncEventDelegate();
-  TNode<BoolT> IsPromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate();
+  TNode<BoolT> IsContextPromiseHookEnabled(TNode<Uint32T> flags);
+  TNode<BoolT> IsContextPromiseHookEnabled() {
+    return IsContextPromiseHookEnabled(PromiseHookFlags());
+  }
+  TNode<BoolT> IsAnyPromiseHookEnabled(TNode<Uint32T> flags);
+  TNode<BoolT> IsAnyPromiseHookEnabled() {
+    return IsAnyPromiseHookEnabled(PromiseHookFlags());
+  }
+  TNode<BoolT> IsIsolatePromiseHookEnabledOrHasAsyncEventDelegate(
+      TNode<Uint32T> flags);
+  TNode<BoolT> IsIsolatePromiseHookEnabledOrHasAsyncEventDelegate() {
+    return IsIsolatePromiseHookEnabledOrHasAsyncEventDelegate(
+        PromiseHookFlags());
+  }
+  TNode<BoolT>
+  IsIsolatePromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate(
+      TNode<Uint32T> flags);
+  TNode<BoolT>
+  IsIsolatePromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate() {
+    return IsIsolatePromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate(
+        PromiseHookFlags());
+  }
+
+  TNode<BoolT> NeedsAnyPromiseHooks(TNode<Uint32T> flags);
+  TNode<BoolT> NeedsAnyPromiseHooks() {
+    return NeedsAnyPromiseHooks(PromiseHookFlags());
+  }
 
   // for..in helpers
   void CheckPrototypeEnumCache(TNode<JSReceiver> receiver,
@@ -3568,6 +3636,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   }
 
   int32_t ConstexprWord32Or(int32_t a, int32_t b) { return a | b; }
+  uint32_t ConstexprWord32Shl(uint32_t a, int32_t b) { return a << b; }
 
   bool ConstexprUintPtrLessThan(uintptr_t a, uintptr_t b) { return a < b; }
 
@@ -3680,12 +3749,10 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
                                     const ForEachKeyValueFunction& body,
                                     Label* bailout);
 
-  TNode<Object> CallGetterIfAccessor(TNode<Object> value,
-                                     TNode<HeapObject> holder,
-                                     TNode<Uint32T> details,
-                                     TNode<Context> context,
-                                     TNode<Object> receiver, Label* if_bailout,
-                                     GetOwnPropertyMode mode = kCallJSGetter);
+  TNode<Object> CallGetterIfAccessor(
+      TNode<Object> value, TNode<HeapObject> holder, TNode<Uint32T> details,
+      TNode<Context> context, TNode<Object> receiver, TNode<Object> name,
+      Label* if_bailout, GetOwnPropertyMode mode = kCallJSGetter);
 
   TNode<IntPtrT> TryToIntptr(TNode<Object> key, Label* if_not_intptr,
                              TVariable<Int32T>* var_instance_type = nullptr);
@@ -3884,6 +3951,10 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
     return CodeAssembler::LoadRoot(root_index);
   }
 
+  TNode<AnyTaggedT> LoadRootMapWord(RootIndex root_index) {
+    return CodeAssembler::LoadRootMapWord(root_index);
+  }
+
   template <typename TIndex>
   void StoreFixedArrayOrPropertyArrayElement(
       TNode<UnionT<FixedArray, PropertyArray>> array, TNode<TIndex> index,
@@ -3923,6 +3994,8 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
                                           TVariable<Number>* var_result,
                                           Label* if_bailout);
 
+  void AssertHasValidMap(TNode<HeapObject> object);
+
   template <typename TValue>
   void EmitElementStoreTypedArray(TNode<JSTypedArray> typed_array,
                                   TNode<IntPtrT> key, TNode<Object> value,
diff --git a/chromium/v8/src/codegen/compilation-cache.cc b/chromium/v8/src/codegen/compilation-cache.cc
index 3941e56e6a6..ee50f8b0153 100644
--- a/chromium/v8/src/codegen/compilation-cache.cc
+++ b/chromium/v8/src/codegen/compilation-cache.cc
@@ -29,10 +29,9 @@ CompilationCache::CompilationCache(Isolate* isolate)
       eval_global_(isolate),
       eval_contextual_(isolate),
       reg_exp_(isolate, kRegExpGenerations),
-      code_(isolate),
       enabled_script_and_eval_(true) {
   CompilationSubCache* subcaches[kSubCacheCount] = {
-      &script_, &eval_global_, &eval_contextual_, &reg_exp_, &code_};
+      &script_, &eval_global_, &eval_contextual_, &reg_exp_};
   for (int i = 0; i < kSubCacheCount; ++i) {
     subcaches_[i] = subcaches[i];
   }
@@ -77,10 +76,6 @@ void CompilationCacheScript::Age() {
 }
 void CompilationCacheEval::Age() { AgeCustom(this); }
 void CompilationCacheRegExp::Age() { AgeByGeneration(this); }
-void CompilationCacheCode::Age() {
-  if (FLAG_trace_turbo_nci) CompilationCacheCode::TraceAgeing();
-  AgeByGeneration(this);
-}
 
 void CompilationSubCache::Iterate(RootVisitor* v) {
   v->VisitRootPointers(Root::kCompilationCache, nullptr,
@@ -267,58 +262,6 @@ void CompilationCacheRegExp::Put(Handle<String> source, JSRegExp::Flags flags,
       CompilationCacheTable::PutRegExp(isolate(), table, source, flags, data));
 }
 
-MaybeHandle<Code> CompilationCacheCode::Lookup(Handle<SharedFunctionInfo> key) {
-  // Make sure not to leak the table into the surrounding handle
-  // scope. Otherwise, we risk keeping old tables around even after
-  // having cleared the cache.
-  HandleScope scope(isolate());
-  MaybeHandle<Code> maybe_value;
-  int generation = 0;
-  for (; generation < generations(); generation++) {
-    Handle<CompilationCacheTable> table = GetTable(generation);
-    maybe_value = table->LookupCode(key);
-    if (!maybe_value.is_null()) break;
-  }
-
-  if (maybe_value.is_null()) {
-    isolate()->counters()->compilation_cache_misses()->Increment();
-    return MaybeHandle<Code>();
-  }
-
-  Handle<Code> value = maybe_value.ToHandleChecked();
-  if (generation != 0) Put(key, value);  // Add to the first generation.
-  isolate()->counters()->compilation_cache_hits()->Increment();
-  return scope.CloseAndEscape(value);
-}
-
-void CompilationCacheCode::Put(Handle<SharedFunctionInfo> key,
-                               Handle<Code> value) {
-  HandleScope scope(isolate());
-  Handle<CompilationCacheTable> table = GetFirstTable();
-  SetFirstTable(CompilationCacheTable::PutCode(isolate(), table, key, value));
-}
-
-void CompilationCacheCode::TraceAgeing() {
-  DCHECK(FLAG_trace_turbo_nci);
-  StdoutStream os;
-  os << "NCI cache ageing: Removing oldest generation" << std::endl;
-}
-
-void CompilationCacheCode::TraceInsertion(Handle<SharedFunctionInfo> key,
-                                          Handle<Code> value) {
-  DCHECK(FLAG_trace_turbo_nci);
-  StdoutStream os;
-  os << "NCI cache insertion: " << Brief(*key) << ", " << Brief(*value)
-     << std::endl;
-}
-
-void CompilationCacheCode::TraceHit(Handle<SharedFunctionInfo> key,
-                                    Handle<Code> value) {
-  DCHECK(FLAG_trace_turbo_nci);
-  StdoutStream os;
-  os << "NCI cache hit: " << Brief(*key) << ", " << Brief(*value) << std::endl;
-}
-
 void CompilationCache::Remove(Handle<SharedFunctionInfo> function_info) {
   if (!IsEnabledScriptAndEval()) return;
 
@@ -372,10 +315,6 @@ MaybeHandle<FixedArray> CompilationCache::LookupRegExp(Handle<String> source,
   return reg_exp_.Lookup(source, flags);
 }
 
-MaybeHandle<Code> CompilationCache::LookupCode(Handle<SharedFunctionInfo> sfi) {
-  return code_.Lookup(sfi);
-}
-
 void CompilationCache::PutScript(Handle<String> source,
                                  LanguageMode language_mode,
                                  Handle<SharedFunctionInfo> function_info) {
@@ -414,11 +353,6 @@ void CompilationCache::PutRegExp(Handle<String> source, JSRegExp::Flags flags,
   reg_exp_.Put(source, flags, data);
 }
 
-void CompilationCache::PutCode(Handle<SharedFunctionInfo> shared,
-                               Handle<Code> code) {
-  code_.Put(shared, code);
-}
-
 void CompilationCache::Clear() {
   for (int i = 0; i < kSubCacheCount; i++) {
     subcaches_[i]->Clear();
diff --git a/chromium/v8/src/codegen/compilation-cache.h b/chromium/v8/src/codegen/compilation-cache.h
index 0ed13e53b6d..d4f4ae52dca 100644
--- a/chromium/v8/src/codegen/compilation-cache.h
+++ b/chromium/v8/src/codegen/compilation-cache.h
@@ -150,32 +150,6 @@ class CompilationCacheRegExp : public CompilationSubCache {
   DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheRegExp);
 };
 
-// Sub-cache for Code objects. All code inserted into this cache must
-// be usable across different native contexts.
-class CompilationCacheCode : public CompilationSubCache {
- public:
-  explicit CompilationCacheCode(Isolate* isolate)
-      : CompilationSubCache(isolate, kGenerations) {}
-
-  MaybeHandle<Code> Lookup(Handle<SharedFunctionInfo> key);
-  void Put(Handle<SharedFunctionInfo> key, Handle<Code> value);
-
-  void Age() override;
-
-  // TODO(jgruber,v8:8888): For simplicity we use the generational
-  // approach here, but could consider something else (or more
-  // generations) in the future.
-  static constexpr int kGenerations = 2;
-
-  static void TraceAgeing();
-  static void TraceInsertion(Handle<SharedFunctionInfo> key,
-                             Handle<Code> value);
-  static void TraceHit(Handle<SharedFunctionInfo> key, Handle<Code> value);
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheCode);
-};
-
 // The compilation cache keeps shared function infos for compiled
 // scripts and evals. The shared function infos are looked up using
 // the source string as the key. For regular expressions the
@@ -206,8 +180,6 @@ class V8_EXPORT_PRIVATE CompilationCache {
   MaybeHandle<FixedArray> LookupRegExp(Handle<String> source,
                                        JSRegExp::Flags flags);
 
-  MaybeHandle<Code> LookupCode(Handle<SharedFunctionInfo> sfi);
-
   // Associate the (source, kind) pair to the shared function
   // info. This may overwrite an existing mapping.
   void PutScript(Handle<String> source, LanguageMode language_mode,
@@ -225,8 +197,6 @@ class V8_EXPORT_PRIVATE CompilationCache {
   void PutRegExp(Handle<String> source, JSRegExp::Flags flags,
                  Handle<FixedArray> data);
 
-  void PutCode(Handle<SharedFunctionInfo> shared, Handle<Code> code);
-
   // Clear the cache - also used to initialize the cache at startup.
   void Clear();
 
@@ -269,9 +239,8 @@ class V8_EXPORT_PRIVATE CompilationCache {
   CompilationCacheEval eval_global_;
   CompilationCacheEval eval_contextual_;
   CompilationCacheRegExp reg_exp_;
-  CompilationCacheCode code_;
 
-  static constexpr int kSubCacheCount = 5;
+  static constexpr int kSubCacheCount = 4;
   CompilationSubCache* subcaches_[kSubCacheCount];
 
   // Current enable state of the compilation cache for scripts and eval.
diff --git a/chromium/v8/src/codegen/compiler.cc b/chromium/v8/src/codegen/compiler.cc
index e46639d90a4..9de4ae24a3a 100644
--- a/chromium/v8/src/codegen/compiler.cc
+++ b/chromium/v8/src/codegen/compiler.cc
@@ -559,10 +559,10 @@ void InstallInterpreterTrampolineCopy(
                                    script_name, line_num, column_num));
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 void InstallUnoptimizedCode(UnoptimizedCompilationInfo* compilation_info,
                             Handle<SharedFunctionInfo> shared_info,
-                            LocalIsolate* isolate) {
+                            IsolateT* isolate) {
   if (compilation_info->has_bytecode_array()) {
     DCHECK(!shared_info->HasBytecodeArray());  // Only compiled once.
     DCHECK(!compilation_info->has_asm_wasm_data());
@@ -585,7 +585,7 @@ void InstallUnoptimizedCode(UnoptimizedCompilationInfo* compilation_info,
 #if V8_ENABLE_WEBASSEMBLY
     DCHECK(compilation_info->has_asm_wasm_data());
     // We should only have asm/wasm data when finalizing on the main thread.
-    DCHECK((std::is_same<LocalIsolate, Isolate>::value));
+    DCHECK((std::is_same<IsolateT, Isolate>::value));
     shared_info->set_asm_wasm_data(*compilation_info->asm_wasm_data());
     shared_info->set_feedback_metadata(
         ReadOnlyRoots(isolate).empty_feedback_metadata());
@@ -606,13 +606,15 @@ void LogUnoptimizedCompilation(Isolate* isolate,
   RecordUnoptimizedCompilationStats(isolate, shared_info);
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 void EnsureSharedFunctionInfosArrayOnScript(Handle<Script> script,
                                             ParseInfo* parse_info,
-                                            LocalIsolate* isolate) {
+                                            IsolateT* isolate) {
   DCHECK(parse_info->flags().is_toplevel());
-  if (script->shared_function_infos().length() > 0) {
-    DCHECK_EQ(script->shared_function_infos().length(),
+  if (script->shared_function_info_count() > 0) {
+    DCHECK_LE(script->shared_function_info_count(),
+              script->shared_function_infos().length());
+    DCHECK_EQ(script->shared_function_info_count(),
               parse_info->max_function_literal_id() + 1);
     return;
   }
@@ -640,26 +642,6 @@ void UpdateSharedFunctionFlagsAfterCompilation(FunctionLiteral* literal,
   shared_info.SetScopeInfo(*literal->scope()->scope_info());
 }
 
-bool CanCompileWithBaseline(Isolate* isolate,
-                            Handle<SharedFunctionInfo> shared) {
-  // Check if we actually have bytecode.
-  if (!shared->HasBytecodeArray()) return false;
-
-  // Do not optimize when debugger needs to hook into every call.
-  if (isolate->debug()->needs_check_on_function_call()) return false;
-
-  // Functions with breakpoints have to stay interpreted.
-  if (shared->HasBreakInfo()) return false;
-
-  // Do not baseline compile if sparkplug is disabled or function doesn't pass
-  // sparkplug_filter.
-  if (!FLAG_sparkplug || !shared->PassesFilter(FLAG_sparkplug_filter)) {
-    return false;
-  }
-
-  return true;
-}
-
 bool CompileSharedWithBaseline(Isolate* isolate,
                                Handle<SharedFunctionInfo> shared,
                                Compiler::ClearExceptionFlag flag,
@@ -671,7 +653,7 @@ bool CompileSharedWithBaseline(Isolate* isolate,
   if (shared->HasBaselineData()) return true;
 
   // Check if we actually can compile with baseline.
-  if (!CanCompileWithBaseline(isolate, shared)) return false;
+  if (!CanCompileWithBaseline(isolate, *shared)) return false;
 
   StackLimitCheck check(isolate);
   if (check.JsHasOverflowed(kStackSpaceRequiredForCompilation * KB)) {
@@ -714,10 +696,10 @@ bool CompileSharedWithBaseline(Isolate* isolate,
 // Finalize a single compilation job. This function can return
 // RETRY_ON_MAIN_THREAD if the job cannot be finalized off-thread, in which case
 // it should be safe to call it again on the main thread with the same job.
-template <typename LocalIsolate>
+template <typename IsolateT>
 CompilationJob::Status FinalizeSingleUnoptimizedCompilationJob(
     UnoptimizedCompilationJob* job, Handle<SharedFunctionInfo> shared_info,
-    LocalIsolate* isolate,
+    IsolateT* isolate,
     FinalizeUnoptimizedCompilationDataList*
         finalize_unoptimized_compilation_data_list) {
   UnoptimizedCompilationInfo* compilation_info = job->compilation_info();
@@ -736,9 +718,8 @@ CompilationJob::Status FinalizeSingleUnoptimizedCompilationJob(
         isolate, shared_info, coverage_info, job->time_taken_to_execute(),
         job->time_taken_to_finalize());
   }
-  DCHECK_IMPLIES(
-      status == CompilationJob::RETRY_ON_MAIN_THREAD,
-      (std::is_same<LocalIsolate, v8::internal::LocalIsolate>::value));
+  DCHECK_IMPLIES(status == CompilationJob::RETRY_ON_MAIN_THREAD,
+                 (std::is_same<IsolateT, LocalIsolate>::value));
   return status;
 }
 
@@ -801,9 +782,9 @@ bool RecursivelyExecuteUnoptimizedCompilationJobs(
   return true;
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 bool IterativelyExecuteAndFinalizeUnoptimizedCompilationJobs(
-    LocalIsolate* isolate, Handle<SharedFunctionInfo> outer_shared_info,
+    IsolateT* isolate, Handle<SharedFunctionInfo> outer_shared_info,
     Handle<Script> script, ParseInfo* parse_info,
     AccountingAllocator* allocator, IsCompiledScope* is_compiled_scope,
     FinalizeUnoptimizedCompilationDataList*
@@ -849,7 +830,7 @@ bool IterativelyExecuteAndFinalizeUnoptimizedCompilationJobs(
 
       case CompilationJob::RETRY_ON_MAIN_THREAD:
         // This should not happen on the main thread.
-        DCHECK((!std::is_same<LocalIsolate, Isolate>::value));
+        DCHECK((!std::is_same<IsolateT, Isolate>::value));
         DCHECK_NOT_NULL(jobs_to_retry_finalization_on_main_thread);
 
         // Clear the literal and ParseInfo to prevent further attempts to
@@ -943,11 +924,9 @@ bool FinalizeDeferredUnoptimizedCompilationJobs(
 V8_WARN_UNUSED_RESULT MaybeHandle<Code> GetCodeFromOptimizedCodeCache(
     Handle<JSFunction> function, BytecodeOffset osr_offset,
     CodeKind code_kind) {
-  RuntimeCallTimerScope runtimeTimer(
-      function->GetIsolate(),
-      RuntimeCallCounterId::kCompileGetFromOptimizedCodeMap);
-  Handle<SharedFunctionInfo> shared(function->shared(), function->GetIsolate());
   Isolate* isolate = function->GetIsolate();
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kCompileGetFromOptimizedCodeMap);
+  Handle<SharedFunctionInfo> shared(function->shared(), isolate);
   DisallowGarbageCollection no_gc;
   Code code;
   if (osr_offset.IsNone() && function->has_feedback_vector()) {
@@ -975,8 +954,6 @@ V8_WARN_UNUSED_RESULT MaybeHandle<Code> GetCodeFromOptimizedCodeCache(
 }
 
 void ClearOptimizedCodeCache(OptimizedCompilationInfo* compilation_info) {
-  DCHECK(!CodeKindIsNativeContextIndependentJSFunction(
-      compilation_info->code_kind()));
   Handle<JSFunction> function = compilation_info->closure();
   if (compilation_info->osr_offset().IsNone()) {
     Handle<FeedbackVector> vector =
@@ -1015,31 +992,6 @@ void InsertCodeIntoOptimizedCodeCache(
   }
 }
 
-void InsertCodeIntoCompilationCache(Isolate* isolate,
-                                    OptimizedCompilationInfo* info) {
-  if (!CodeKindIsNativeContextIndependentJSFunction(info->code_kind())) return;
-
-  DCHECK(info->osr_offset().IsNone());
-
-  Handle<Code> code = info->code();
-  DCHECK(!info->function_context_specializing());
-
-  Handle<SharedFunctionInfo> sfi = info->shared_info();
-  CompilationCache* cache = isolate->compilation_cache();
-  cache->PutCode(sfi, code);
-  DCHECK(!cache->LookupCode(sfi).is_null());
-
-  sfi->set_may_have_cached_code(true);
-
-  if (FLAG_trace_turbo_nci) CompilationCacheCode::TraceInsertion(sfi, code);
-}
-
-V8_WARN_UNUSED_RESULT MaybeHandle<Code> GetCodeFromCompilationCache(
-    Isolate* isolate, Handle<SharedFunctionInfo> shared) {
-  if (!shared->may_have_cached_code()) return {};
-  return shared->TryGetCachedCode(isolate);
-}
-
 // Runs PrepareJob in the proper compilation & canonical scopes. Handles will be
 // allocated in a persistent handle scope that is detached and handed off to the
 // {compilation_info} after PrepareJob.
@@ -1054,8 +1006,7 @@ bool PrepareJobWithHandleScope(OptimizedCompilationJob* job, Isolate* isolate,
 bool GetOptimizedCodeNow(OptimizedCompilationJob* job, Isolate* isolate,
                          OptimizedCompilationInfo* compilation_info) {
   TimerEventScope<TimerEventRecompileSynchronous> timer(isolate);
-  RuntimeCallTimerScope runtimeTimer(
-      isolate, RuntimeCallCounterId::kOptimizeNonConcurrent);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kOptimizeNonConcurrent);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                "V8.OptimizeNonConcurrent");
 
@@ -1111,8 +1062,7 @@ bool GetOptimizedCodeLater(std::unique_ptr<OptimizedCompilationJob> job,
   }
 
   TimerEventScope<TimerEventRecompileSynchronous> timer(isolate);
-  RuntimeCallTimerScope runtimeTimer(
-      isolate, RuntimeCallCounterId::kOptimizeConcurrentPrepare);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kOptimizeConcurrentPrepare);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                "V8.OptimizeConcurrentPrepare");
 
@@ -1134,11 +1084,10 @@ bool GetOptimizedCodeLater(std::unique_ptr<OptimizedCompilationJob> job,
     function->SetOptimizationMarker(OptimizationMarker::kInOptimizationQueue);
   }
 
-  // Note: Usually the active tier is expected to be Ignition or NCI at this
-  // point (in other words we don't expect to optimize if the function is
-  // already TF-optimized). There is a special case for OSR though, for which
-  // we *can* reach this point even if we've already generated non-OSR'd TF
-  // code.
+  // Note: Usually the active tier is expected to be Ignition at this point (in
+  // other words we don't expect to optimize if the function is already
+  // TF-optimized). There is a special case for OSR though, for which we *can*
+  // reach this point even if we've already generated non-OSR'd TF code.
   DCHECK(function->shared().HasBytecodeArray());
   return true;
 }
@@ -1148,13 +1097,7 @@ bool GetOptimizedCodeLater(std::unique_ptr<OptimizedCompilationJob> job,
 Handle<Code> ContinuationForConcurrentOptimization(
     Isolate* isolate, Handle<JSFunction> function) {
   Handle<Code> cached_code;
-  if (FLAG_turbo_nci && function->NextTier() == CodeKindForTopTier() &&
-      GetCodeFromCompilationCache(isolate, handle(function->shared(), isolate))
-          .ToHandle(&cached_code)) {
-    // Tiering up to Turbofan and cached optimized code exists. Continue
-    // execution there until TF optimization has finished.
-    return cached_code;
-  } else if (FLAG_turboprop && function->HasAvailableOptimizedCode()) {
+  if (FLAG_turboprop && function->HasAvailableOptimizedCode()) {
     DCHECK(!FLAG_turboprop_as_toptier);
     DCHECK(function->NextTier() == CodeKind::TURBOFAN);
     // It is possible that we have marked a closure for TurboFan optimization
@@ -1179,23 +1122,26 @@ Handle<Code> ContinuationForConcurrentOptimization(
   return BUILTIN_CODE(isolate, InterpreterEntryTrampoline);
 }
 
+enum class GetOptimizedCodeResultHandling {
+  // Default behavior, i.e. install the result, insert into caches, etc.
+  kDefault,
+  // Used only for stress testing. The compilation result should be discarded.
+  kDiscardForTesting,
+};
+
 MaybeHandle<Code> GetOptimizedCode(
-    Handle<JSFunction> function, ConcurrencyMode mode, CodeKind code_kind,
-    BytecodeOffset osr_offset = BytecodeOffset::None(),
-    JavaScriptFrame* osr_frame = nullptr) {
+    Isolate* isolate, Handle<JSFunction> function, ConcurrencyMode mode,
+    CodeKind code_kind, BytecodeOffset osr_offset = BytecodeOffset::None(),
+    JavaScriptFrame* osr_frame = nullptr,
+    GetOptimizedCodeResultHandling result_handling =
+        GetOptimizedCodeResultHandling::kDefault) {
   DCHECK(CodeKindIsOptimizedJSFunction(code_kind));
 
-  Isolate* isolate = function->GetIsolate();
   Handle<SharedFunctionInfo> shared(function->shared(), isolate);
 
   // Make sure we clear the optimization marker on the function so that we
   // don't try to re-optimize.
-  // If compiling for NCI (which does not use the optimization marker), don't
-  // touch the marker to avoid interfering with Turbofan compilation.
-  if (!CodeKindIsNativeContextIndependentJSFunction(code_kind) &&
-      function->HasOptimizationMarker()) {
-    function->ClearOptimizationMarker();
-  }
+  if (function->HasOptimizationMarker()) function->ClearOptimizationMarker();
 
   if (shared->optimization_disabled() &&
       shared->disable_optimization_reason() == BailoutReason::kNeverOptimize) {
@@ -1233,25 +1179,9 @@ MaybeHandle<Code> GetOptimizedCode(
   DCHECK(shared->is_compiled());
   function->feedback_vector().set_profiler_ticks(0);
 
-  // Check the compilation cache (stored on the Isolate, shared between native
-  // contexts).
-  if (CodeKindIsNativeContextIndependentJSFunction(code_kind)) {
-    DCHECK(osr_offset.IsNone());
-
-    Handle<Code> cached_code;
-    if (GetCodeFromCompilationCache(isolate, shared).ToHandle(&cached_code)) {
-      CHECK_EQ(cached_code->kind(), CodeKind::NATIVE_CONTEXT_INDEPENDENT);
-      if (FLAG_trace_turbo_nci) {
-        CompilationCacheCode::TraceHit(shared, cached_code);
-      }
-      return cached_code;
-    }
-  }
-
   VMState<COMPILER> state(isolate);
   TimerEventScope<TimerEventOptimizeCode> optimize_code_timer(isolate);
-  RuntimeCallTimerScope runtimeTimer(isolate,
-                                     RuntimeCallCounterId::kOptimizeCode);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kOptimizeCode);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.OptimizeCode");
 
   DCHECK(!isolate->has_pending_exception());
@@ -1265,6 +1195,10 @@ MaybeHandle<Code> GetOptimizedCode(
                                             has_script, osr_offset, osr_frame));
   OptimizedCompilationInfo* compilation_info = job->compilation_info();
 
+  if (result_handling == GetOptimizedCodeResultHandling::kDiscardForTesting) {
+    compilation_info->set_discard_result_for_testing();
+  }
+
   // Prepare the job and launch concurrent compilation, or compile now.
   if (mode == ConcurrencyMode::kConcurrent) {
     if (GetOptimizedCodeLater(std::move(job), isolate, compilation_info,
@@ -1274,7 +1208,6 @@ MaybeHandle<Code> GetOptimizedCode(
   } else {
     DCHECK_EQ(mode, ConcurrencyMode::kNotConcurrent);
     if (GetOptimizedCodeNow(job.get(), isolate, compilation_info)) {
-      InsertCodeIntoCompilationCache(isolate, compilation_info);
       return compilation_info->code();
     }
   }
@@ -1283,13 +1216,30 @@ MaybeHandle<Code> GetOptimizedCode(
   return {};
 }
 
+// When --stress-concurrent-inlining is enabled, spawn concurrent jobs in
+// addition to non-concurrent compiles to increase coverage in mjsunit tests
+// (where most interesting compiles are non-concurrent). The result of the
+// compilation is thrown out.
+void SpawnDuplicateConcurrentJobForStressTesting(Isolate* isolate,
+                                                 Handle<JSFunction> function,
+                                                 ConcurrencyMode mode,
+                                                 CodeKind code_kind) {
+  DCHECK(FLAG_stress_concurrent_inlining &&
+         isolate->concurrent_recompilation_enabled() &&
+         mode == ConcurrencyMode::kNotConcurrent &&
+         isolate->node_observer() == nullptr);
+  USE(GetOptimizedCode(isolate, function, ConcurrencyMode::kConcurrent,
+                       code_kind, BytecodeOffset::None(), nullptr,
+                       GetOptimizedCodeResultHandling::kDiscardForTesting));
+}
+
 bool FailAndClearPendingException(Isolate* isolate) {
   isolate->clear_pending_exception();
   return false;
 }
 
-template <typename LocalIsolate>
-bool PreparePendingException(LocalIsolate* isolate, ParseInfo* parse_info) {
+template <typename IsolateT>
+bool PreparePendingException(IsolateT* isolate, ParseInfo* parse_info) {
   if (parse_info->pending_error_handler()->has_pending_error()) {
     parse_info->pending_error_handler()->PrepareErrors(
         isolate, parse_info->ast_value_factory());
@@ -1389,8 +1339,7 @@ void FinalizeUnoptimizedScriptCompilation(
       FunctionLiteral* literal = it.first;
       CompilerDispatcher::JobId job_id = it.second;
       MaybeHandle<SharedFunctionInfo> maybe_shared_for_task =
-          script->FindSharedFunctionInfo(isolate,
-                                         literal->function_literal_id());
+          Script::FindSharedFunctionInfo(script, isolate, literal);
       Handle<SharedFunctionInfo> shared_for_task;
       if (maybe_shared_for_task.ToHandle(&shared_for_task)) {
         dispatcher->RegisterSharedFunctionInfo(job_id, *shared_for_task);
@@ -1412,7 +1361,7 @@ void CompileAllWithBaseline(Isolate* isolate,
     Handle<SharedFunctionInfo> shared_info = finalize_data.function_handle();
     IsCompiledScope is_compiled_scope(*shared_info, isolate);
     if (!is_compiled_scope.is_compiled()) continue;
-    if (!CanCompileWithBaseline(isolate, shared_info)) continue;
+    if (!CanCompileWithBaseline(isolate, *shared_info)) continue;
     CompileSharedWithBaseline(isolate, shared_info, Compiler::CLEAR_EXCEPTION,
                               &is_compiled_scope);
   }
@@ -1420,9 +1369,9 @@ void CompileAllWithBaseline(Isolate* isolate,
 
 // Create shared function info for top level and shared function infos array for
 // inner functions.
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<SharedFunctionInfo> CreateTopLevelSharedFunctionInfo(
-    ParseInfo* parse_info, Handle<Script> script, LocalIsolate* isolate) {
+    ParseInfo* parse_info, Handle<Script> script, IsolateT* isolate) {
   EnsureSharedFunctionInfosArrayOnScript(script, parse_info, isolate);
   DCHECK_EQ(kNoSourcePosition,
             parse_info->literal()->function_token_position());
@@ -1440,10 +1389,9 @@ MaybeHandle<SharedFunctionInfo> CompileToplevel(
 
   PostponeInterruptsScope postpone(isolate);
   DCHECK(!isolate->native_context().is_null());
-  RuntimeCallTimerScope runtimeTimer(
-      isolate, parse_info->flags().is_eval()
-                   ? RuntimeCallCounterId::kCompileEval
-                   : RuntimeCallCounterId::kCompileScript);
+  RCS_SCOPE(isolate, parse_info->flags().is_eval()
+                         ? RuntimeCallCounterId::kCompileEval
+                         : RuntimeCallCounterId::kCompileScript);
   VMState<BYTECODE_COMPILER> state(isolate);
   if (parse_info->literal() == nullptr &&
       !parsing::ParseProgram(parse_info, script, maybe_outer_scope_info,
@@ -1494,6 +1442,7 @@ MaybeHandle<SharedFunctionInfo> CompileToplevel(
   return shared_info;
 }
 
+#ifdef V8_RUNTIME_CALL_STATS
 RuntimeCallCounterId RuntimeCallCounterIdForCompileBackground(
     ParseInfo* parse_info) {
   if (parse_info->flags().is_toplevel()) {
@@ -1504,6 +1453,7 @@ RuntimeCallCounterId RuntimeCallCounterIdForCompileBackground(
   }
   return RuntimeCallCounterId::kCompileBackgroundFunction;
 }
+#endif  // V8_RUNTIME_CALL_STATS
 
 MaybeHandle<SharedFunctionInfo> CompileAndFinalizeOnBackgroundThread(
     ParseInfo* parse_info, AccountingAllocator* allocator,
@@ -1514,9 +1464,8 @@ MaybeHandle<SharedFunctionInfo> CompileAndFinalizeOnBackgroundThread(
     IsCompiledScope* is_compiled_scope) {
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                "V8.CompileCodeBackground");
-  RuntimeCallTimerScope runtimeTimer(
-      parse_info->runtime_call_stats(),
-      RuntimeCallCounterIdForCompileBackground(parse_info));
+  RCS_SCOPE(parse_info->runtime_call_stats(),
+            RuntimeCallCounterIdForCompileBackground(parse_info));
 
   Handle<SharedFunctionInfo> shared_info =
       CreateTopLevelSharedFunctionInfo(parse_info, script, isolate);
@@ -1541,9 +1490,8 @@ void CompileOnBackgroundThread(ParseInfo* parse_info,
   DisallowHeapAccess no_heap_access;
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                "V8.CompileCodeBackground");
-  RuntimeCallTimerScope runtimeTimer(
-      parse_info->runtime_call_stats(),
-      RuntimeCallCounterIdForCompileBackground(parse_info));
+  RCS_SCOPE(parse_info->runtime_call_stats(),
+            RuntimeCallCounterIdForCompileBackground(parse_info));
 
   // Generate the unoptimized bytecode or asm-js data.
   DCHECK(jobs->empty());
@@ -1557,6 +1505,7 @@ void CompileOnBackgroundThread(ParseInfo* parse_info,
   // Character stream shouldn't be used again.
   parse_info->ResetCharacterStream();
 }
+
 }  // namespace
 
 CompilationHandleScope::~CompilationHandleScope() {
@@ -1660,8 +1609,8 @@ class V8_NODISCARD OffThreadParseInfoScope {
       ParseInfo* parse_info,
       WorkerThreadRuntimeCallStats* worker_thread_runtime_stats, int stack_size)
       : parse_info_(parse_info),
-        original_runtime_call_stats_(parse_info_->runtime_call_stats()),
         original_stack_limit_(parse_info_->stack_limit()),
+        original_runtime_call_stats_(parse_info_->runtime_call_stats()),
         worker_thread_scope_(worker_thread_runtime_stats) {
     parse_info_->SetPerThreadState(GetCurrentStackPosition() - stack_size * KB,
                                    worker_thread_scope_.Get());
@@ -1678,8 +1627,8 @@ class V8_NODISCARD OffThreadParseInfoScope {
 
  private:
   ParseInfo* parse_info_;
-  RuntimeCallStats* original_runtime_call_stats_;
   uintptr_t original_stack_limit_;
+  RuntimeCallStats* original_runtime_call_stats_;
   WorkerThreadRuntimeCallStatsScope worker_thread_scope_;
 };
 
@@ -1692,9 +1641,8 @@ void BackgroundCompileTask::Run() {
       stack_size_);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                "BackgroundCompileTask::Run");
-  RuntimeCallTimerScope runtimeTimer(
-      info_->runtime_call_stats(),
-      RuntimeCallCounterId::kCompileBackgroundCompileTask);
+  RCS_SCOPE(info_->runtime_call_stats(),
+            RuntimeCallCounterId::kCompileBackgroundCompileTask);
 
   // Update the character stream's runtime call stats.
   info_->character_stream()->set_runtime_call_stats(
@@ -1817,8 +1765,7 @@ bool Compiler::CollectSourcePositions(Isolate* isolate,
   DCHECK(!isolate->has_pending_exception());
   VMState<BYTECODE_COMPILER> state(isolate);
   PostponeInterruptsScope postpone(isolate);
-  RuntimeCallTimerScope runtimeTimer(
-      isolate, RuntimeCallCounterId::kCompileCollectSourcePositions);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kCompileCollectSourcePositions);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                "V8.CollectSourcePositions");
   HistogramTimerScope timer(isolate->counters()->collect_source_positions());
@@ -1894,8 +1841,7 @@ bool Compiler::Compile(Isolate* isolate, Handle<SharedFunctionInfo> shared_info,
   VMState<BYTECODE_COMPILER> state(isolate);
   PostponeInterruptsScope postpone(isolate);
   TimerEventScope<TimerEventCompileCode> compile_timer(isolate);
-  RuntimeCallTimerScope runtimeTimer(isolate,
-                                     RuntimeCallCounterId::kCompileFunction);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kCompileFunction);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.CompileCode");
   AggregatedHistogramTimerScope timer(isolate->counters()->compile_lazy());
 
@@ -2000,9 +1946,19 @@ bool Compiler::Compile(Isolate* isolate, Handle<JSFunction> function,
     CompilerTracer::TraceOptimizeForAlwaysOpt(isolate, function,
                                               CodeKindForTopTier());
 
+    const CodeKind code_kind = CodeKindForTopTier();
+    const ConcurrencyMode concurrency_mode = ConcurrencyMode::kNotConcurrent;
+
+    if (FLAG_stress_concurrent_inlining &&
+        isolate->concurrent_recompilation_enabled() &&
+        concurrency_mode == ConcurrencyMode::kNotConcurrent &&
+        isolate->node_observer() == nullptr) {
+      SpawnDuplicateConcurrentJobForStressTesting(isolate, function,
+                                                  concurrency_mode, code_kind);
+    }
+
     Handle<Code> maybe_code;
-    if (GetOptimizedCode(function, ConcurrencyMode::kNotConcurrent,
-                         CodeKindForTopTier())
+    if (GetOptimizedCode(isolate, function, concurrency_mode, code_kind)
             .ToHandle(&maybe_code)) {
       code = maybe_code;
     }
@@ -2058,8 +2014,8 @@ bool Compiler::FinalizeBackgroundCompileTask(
 
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                "V8.FinalizeBackgroundCompileTask");
-  RuntimeCallTimerScope runtimeTimer(
-      isolate, RuntimeCallCounterId::kCompileFinalizeBackgroundCompileTask);
+  RCS_SCOPE(isolate,
+            RuntimeCallCounterId::kCompileFinalizeBackgroundCompileTask);
   HandleScope scope(isolate);
   ParseInfo* parse_info = task->info();
   DCHECK(!parse_info->flags().is_toplevel());
@@ -2099,8 +2055,16 @@ bool Compiler::CompileOptimized(Isolate* isolate, Handle<JSFunction> function,
   DCHECK(CodeKindIsOptimizedJSFunction(code_kind));
   DCHECK(AllowCompilation::IsAllowed(isolate));
 
+  if (FLAG_stress_concurrent_inlining &&
+      isolate->concurrent_recompilation_enabled() &&
+      mode == ConcurrencyMode::kNotConcurrent &&
+      isolate->node_observer() == nullptr) {
+    SpawnDuplicateConcurrentJobForStressTesting(isolate, function, mode,
+                                                code_kind);
+  }
+
   Handle<Code> code;
-  if (!GetOptimizedCode(function, mode, code_kind).ToHandle(&code)) {
+  if (!GetOptimizedCode(isolate, function, mode, code_kind).ToHandle(&code)) {
     // Optimization failed, get the existing code. We could have optimized code
     // from a lower tier here. Unoptimized code must exist already if we are
     // optimizing.
@@ -2110,23 +2074,18 @@ bool Compiler::CompileOptimized(Isolate* isolate, Handle<JSFunction> function,
     code = ContinuationForConcurrentOptimization(isolate, function);
   }
 
-  if (!CodeKindIsNativeContextIndependentJSFunction(code_kind)) {
-    function->set_code(*code, kReleaseStore);
-  }
+  function->set_code(*code, kReleaseStore);
 
   // Check postconditions on success.
   DCHECK(!isolate->has_pending_exception());
   DCHECK(function->shared().is_compiled());
-  DCHECK(CodeKindIsNativeContextIndependentJSFunction(code_kind) ||
-         function->is_compiled());
-  if (!CodeKindIsNativeContextIndependentJSFunction(code_kind)) {
-    DCHECK_IMPLIES(function->HasOptimizationMarker(),
-                   function->IsInOptimizationQueue());
-    DCHECK_IMPLIES(function->HasOptimizationMarker(),
-                   function->ChecksOptimizationMarker());
-    DCHECK_IMPLIES(function->IsInOptimizationQueue(),
-                   mode == ConcurrencyMode::kConcurrent);
-  }
+  DCHECK(function->is_compiled());
+  DCHECK_IMPLIES(function->HasOptimizationMarker(),
+                 function->IsInOptimizationQueue());
+  DCHECK_IMPLIES(function->HasOptimizationMarker(),
+                 function->ChecksOptimizationMarker());
+  DCHECK_IMPLIES(function->IsInOptimizationQueue(),
+                 mode == ConcurrencyMode::kConcurrent);
   return true;
 }
 
@@ -2281,8 +2240,7 @@ bool CodeGenerationFromStringsAllowed(Isolate* isolate, Handle<Context> context,
 
   // Callback set. Let it decide if code generation is allowed.
   VMState<EXTERNAL> state(isolate);
-  RuntimeCallTimerScope timer(
-      isolate, RuntimeCallCounterId::kCodeGenerationFromStringsCallbacks);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kCodeGenerationFromStringsCallbacks);
   AllowCodeGenerationFromStringsCallback callback =
       isolate->allow_code_gen_callback();
   return callback(v8::Utils::ToLocal(context), v8::Utils::ToLocal(source));
@@ -2301,8 +2259,7 @@ bool ModifyCodeGenerationFromStrings(Isolate* isolate, Handle<Context> context,
   // Callback set. Run it, and use the return value as source, or block
   // execution if it's not set.
   VMState<EXTERNAL> state(isolate);
-  RuntimeCallTimerScope timer(
-      isolate, RuntimeCallCounterId::kCodeGenerationFromStringsCallbacks);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kCodeGenerationFromStringsCallbacks);
   ModifyCodeGenerationFromStringsResult result =
       isolate->modify_code_gen_callback()
           ? isolate->modify_code_gen_callback()(v8::Utils::ToLocal(context),
@@ -2881,8 +2838,7 @@ MaybeHandle<SharedFunctionInfo> Compiler::GetSharedFunctionInfoForScript(
       compile_timer.set_consuming_code_cache();
       // Then check cached code provided by embedder.
       HistogramTimerScope timer(isolate->counters()->compile_deserialize());
-      RuntimeCallTimerScope runtimeTimer(
-          isolate, RuntimeCallCounterId::kCompileDeserialize);
+      RCS_SCOPE(isolate, RuntimeCallCounterId::kCompileDeserialize);
       TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                    "V8.CompileDeserialize");
       Handle<SharedFunctionInfo> inner_result;
@@ -2894,7 +2850,6 @@ MaybeHandle<SharedFunctionInfo> Compiler::GetSharedFunctionInfoForScript(
         is_compiled_scope = inner_result->is_compiled_scope(isolate);
         DCHECK(is_compiled_scope.is_compiled());
         compilation_cache->PutScript(source, language_mode, inner_result);
-        Handle<Script> script(Script::cast(inner_result->script()), isolate);
         maybe_result = inner_result;
       } else {
         // Deserializer failed. Fall through to compile.
@@ -2970,8 +2925,7 @@ MaybeHandle<JSFunction> Compiler::GetWrappedFunction(
     compile_timer.set_consuming_code_cache();
     // Then check cached code provided by embedder.
     HistogramTimerScope timer(isolate->counters()->compile_deserialize());
-    RuntimeCallTimerScope runtimeTimer(
-        isolate, RuntimeCallCounterId::kCompileDeserialize);
+    RCS_SCOPE(isolate, RuntimeCallCounterId::kCompileDeserialize);
     TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                  "V8.CompileDeserialize");
     maybe_result = CodeSerializer::Deserialize(isolate, cached_data, source,
@@ -3074,8 +3028,8 @@ Compiler::GetSharedFunctionInfoForStreamedScript(
 
     Handle<Script> script;
     if (FLAG_finalize_streaming_on_background && !origin_options.IsModule()) {
-      RuntimeCallTimerScope runtimeTimerScope(
-          isolate, RuntimeCallCounterId::kCompilePublishBackgroundFinalization);
+      RCS_SCOPE(isolate,
+                RuntimeCallCounterId::kCompilePublishBackgroundFinalization);
       TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                    "V8.OffThreadFinalization.Publish");
 
@@ -3163,15 +3117,14 @@ Compiler::GetSharedFunctionInfoForStreamedScript(
 }
 
 // static
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfo(
-    FunctionLiteral* literal, Handle<Script> script, LocalIsolate* isolate) {
+    FunctionLiteral* literal, Handle<Script> script, IsolateT* isolate) {
   // Precondition: code has been parsed and scopes have been analyzed.
   MaybeHandle<SharedFunctionInfo> maybe_existing;
 
   // Find any previously allocated shared function info for the given literal.
-  maybe_existing =
-      script->FindSharedFunctionInfo(isolate, literal->function_literal_id());
+  maybe_existing = Script::FindSharedFunctionInfo(script, isolate, literal);
 
   // If we found an existing shared function info, return it.
   Handle<SharedFunctionInfo> existing;
@@ -3215,12 +3168,13 @@ template Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfo(
     FunctionLiteral* literal, Handle<Script> script, LocalIsolate* isolate);
 
 // static
-MaybeHandle<Code> Compiler::GetOptimizedCodeForOSR(Handle<JSFunction> function,
+MaybeHandle<Code> Compiler::GetOptimizedCodeForOSR(Isolate* isolate,
+                                                   Handle<JSFunction> function,
                                                    BytecodeOffset osr_offset,
                                                    JavaScriptFrame* osr_frame) {
   DCHECK(!osr_offset.IsNone());
   DCHECK_NOT_NULL(osr_frame);
-  return GetOptimizedCode(function, ConcurrencyMode::kNotConcurrent,
+  return GetOptimizedCode(isolate, function, ConcurrencyMode::kNotConcurrent,
                           CodeKindForOSR(), osr_offset, osr_frame);
 }
 
@@ -3233,17 +3187,14 @@ bool Compiler::FinalizeOptimizedCompilationJob(OptimizedCompilationJob* job,
   OptimizedCompilationInfo* compilation_info = job->compilation_info();
 
   TimerEventScope<TimerEventRecompileSynchronous> timer(isolate);
-  RuntimeCallTimerScope runtimeTimer(
-      isolate, RuntimeCallCounterId::kOptimizeConcurrentFinalize);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kOptimizeConcurrentFinalize);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                "V8.OptimizeConcurrentFinalize");
 
   Handle<SharedFunctionInfo> shared = compilation_info->shared_info();
 
-  CodeKind code_kind = compilation_info->code_kind();
-  const bool should_install_code_on_function =
-      !CodeKindIsNativeContextIndependentJSFunction(code_kind);
-  if (should_install_code_on_function) {
+  const bool use_result = !compilation_info->discard_result_for_testing();
+  if (V8_LIKELY(use_result)) {
     // Reset profiler ticks, function is no longer considered hot.
     compilation_info->closure()->feedback_vector().set_profiler_ticks(0);
   }
@@ -3263,10 +3214,9 @@ bool Compiler::FinalizeOptimizedCompilationJob(OptimizedCompilationJob* job,
                                   isolate);
       job->RecordFunctionCompilation(CodeEventListener::LAZY_COMPILE_TAG,
                                      isolate);
-      InsertCodeIntoOptimizedCodeCache(compilation_info);
-      InsertCodeIntoCompilationCache(isolate, compilation_info);
-      CompilerTracer::TraceCompletedJob(isolate, compilation_info);
-      if (should_install_code_on_function) {
+      if (V8_LIKELY(use_result)) {
+        InsertCodeIntoOptimizedCodeCache(compilation_info);
+        CompilerTracer::TraceCompletedJob(isolate, compilation_info);
         compilation_info->closure()->set_code(*compilation_info->code(),
                                               kReleaseStore);
       }
@@ -3276,11 +3226,12 @@ bool Compiler::FinalizeOptimizedCompilationJob(OptimizedCompilationJob* job,
 
   DCHECK_EQ(job->state(), CompilationJob::State::kFailed);
   CompilerTracer::TraceAbortedJob(isolate, compilation_info);
-  compilation_info->closure()->set_code(shared->GetCode(), kReleaseStore);
-  // Clear the InOptimizationQueue marker, if it exists.
-  if (!CodeKindIsNativeContextIndependentJSFunction(code_kind) &&
-      compilation_info->closure()->IsInOptimizationQueue()) {
-    compilation_info->closure()->ClearOptimizationMarker();
+  if (V8_LIKELY(use_result)) {
+    compilation_info->closure()->set_code(shared->GetCode(), kReleaseStore);
+    // Clear the InOptimizationQueue marker, if it exists.
+    if (compilation_info->closure()->IsInOptimizationQueue()) {
+      compilation_info->closure()->ClearOptimizationMarker();
+    }
   }
   return CompilationJob::FAILED;
 }
diff --git a/chromium/v8/src/codegen/compiler.h b/chromium/v8/src/codegen/compiler.h
index 7ff1b5eecd4..e7d05b3ba3b 100644
--- a/chromium/v8/src/codegen/compiler.h
+++ b/chromium/v8/src/codegen/compiler.h
@@ -190,9 +190,10 @@ class V8_EXPORT_PRIVATE Compiler : public AllStatic {
 
   // Create a shared function info object for the given function literal
   // node (the code may be lazily compiled).
-  template <typename LocalIsolate>
-  static Handle<SharedFunctionInfo> GetSharedFunctionInfo(
-      FunctionLiteral* node, Handle<Script> script, LocalIsolate* isolate);
+  template <typename IsolateT>
+  static Handle<SharedFunctionInfo> GetSharedFunctionInfo(FunctionLiteral* node,
+                                                          Handle<Script> script,
+                                                          IsolateT* isolate);
 
   // ===========================================================================
   // The following family of methods provides support for OSR. Code generated
@@ -205,7 +206,7 @@ class V8_EXPORT_PRIVATE Compiler : public AllStatic {
 
   // Generate and return optimized code for OSR, or empty handle on failure.
   V8_WARN_UNUSED_RESULT static MaybeHandle<Code> GetOptimizedCodeForOSR(
-      Handle<JSFunction> function, BytecodeOffset osr_offset,
+      Isolate* isolate, Handle<JSFunction> function, BytecodeOffset osr_offset,
       JavaScriptFrame* osr_frame);
 };
 
diff --git a/chromium/v8/src/codegen/constants-arch.h b/chromium/v8/src/codegen/constants-arch.h
index cea8dc068fe..2417be5d4dc 100644
--- a/chromium/v8/src/codegen/constants-arch.h
+++ b/chromium/v8/src/codegen/constants-arch.h
@@ -6,23 +6,23 @@
 #define V8_CODEGEN_CONSTANTS_ARCH_H_
 
 #if V8_TARGET_ARCH_ARM
-#include "src/codegen/arm/constants-arm.h"  // NOLINT
+#include "src/codegen/arm/constants-arm.h"
 #elif V8_TARGET_ARCH_ARM64
-#include "src/codegen/arm64/constants-arm64.h"  // NOLINT
+#include "src/codegen/arm64/constants-arm64.h"
 #elif V8_TARGET_ARCH_IA32
-#include "src/codegen/ia32/constants-ia32.h"  // NOLINT
+#include "src/codegen/ia32/constants-ia32.h"
 #elif V8_TARGET_ARCH_MIPS
-#include "src/codegen/mips/constants-mips.h"  // NOLINT
+#include "src/codegen/mips/constants-mips.h"
 #elif V8_TARGET_ARCH_MIPS64
-#include "src/codegen/mips64/constants-mips64.h"  // NOLINT
+#include "src/codegen/mips64/constants-mips64.h"
 #elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
-#include "src/codegen/ppc/constants-ppc.h"  // NOLINT
+#include "src/codegen/ppc/constants-ppc.h"
 #elif V8_TARGET_ARCH_S390
-#include "src/codegen/s390/constants-s390.h"  // NOLINT
+#include "src/codegen/s390/constants-s390.h"
 #elif V8_TARGET_ARCH_X64
-#include "src/codegen/x64/constants-x64.h"  // NOLINT
+#include "src/codegen/x64/constants-x64.h"
 #elif V8_TARGET_ARCH_RISCV64
-#include "src/codegen/riscv64/constants-riscv64.h"  // NOLINT
+#include "src/codegen/riscv64/constants-riscv64.h"
 #else
 #error Unsupported target architecture.
 #endif
diff --git a/chromium/v8/src/codegen/cpu-features.h b/chromium/v8/src/codegen/cpu-features.h
index b9a450ea3a0..6833ee60d08 100644
--- a/chromium/v8/src/codegen/cpu-features.h
+++ b/chromium/v8/src/codegen/cpu-features.h
@@ -109,6 +109,9 @@ class V8_EXPORT_PRIVATE CpuFeatures : public AllStatic {
     return (supported_ & (1u << f)) != 0;
   }
 
+  static void SetSupported(CpuFeature f) { supported_ |= 1u << f; }
+  static void SetUnsupported(CpuFeature f) { supported_ &= ~(1u << f); }
+
   static bool SupportsWasmSimd128();
 
   static inline bool SupportsOptimizer();
diff --git a/chromium/v8/src/codegen/external-reference-table.cc b/chromium/v8/src/codegen/external-reference-table.cc
index 2741bd8ec2a..6c109861a2c 100644
--- a/chromium/v8/src/codegen/external-reference-table.cc
+++ b/chromium/v8/src/codegen/external-reference-table.cc
@@ -33,20 +33,24 @@ namespace internal {
 // clang-format off
 const char* const
     ExternalReferenceTable::ref_name_[ExternalReferenceTable::kSize] = {
+        // === Isolate independent ===
         // Special references:
         "nullptr",
-        // External references:
+        // External references (without isolate):
         EXTERNAL_REFERENCE_LIST(ADD_EXT_REF_NAME)
-        EXTERNAL_REFERENCE_LIST_WITH_ISOLATE(ADD_EXT_REF_NAME)
         // Builtins:
         BUILTIN_LIST_C(ADD_BUILTIN_NAME)
         // Runtime functions:
         FOR_EACH_INTRINSIC(ADD_RUNTIME_FUNCTION)
-        // Isolate addresses:
-        FOR_EACH_ISOLATE_ADDRESS_NAME(ADD_ISOLATE_ADDR)
         // Accessors:
         ACCESSOR_INFO_LIST_GENERATOR(ADD_ACCESSOR_INFO_NAME, /* not used */)
         ACCESSOR_SETTER_LIST(ADD_ACCESSOR_SETTER_NAME)
+
+        // === Isolate dependent ===
+        // External references (with isolate):
+        EXTERNAL_REFERENCE_LIST_WITH_ISOLATE(ADD_EXT_REF_NAME)
+        // Isolate addresses:
+        FOR_EACH_ISOLATE_ADDRESS_NAME(ADD_ISOLATE_ADDR)
         // Stub cache:
         "Load StubCache::primary_->key",
         "Load StubCache::primary_->value",
@@ -72,6 +76,11 @@ const char* const
 #undef ADD_ACCESSOR_SETTER_NAME
 #undef ADD_STATS_COUNTER_NAME
 
+namespace {
+static Address ref_addr_isolate_independent_
+    [ExternalReferenceTable::kSizeIsolateIndependent] = {0};
+}  // namespace
+
 // Forward declarations for C++ builtins.
 #define FORWARD_DECLARE(Name) \
   Address Builtin_##Name(int argc, Address* args, Isolate* isolate);
@@ -81,13 +90,10 @@ BUILTIN_LIST_C(FORWARD_DECLARE)
 void ExternalReferenceTable::Init(Isolate* isolate) {
   int index = 0;
 
-  // kNullAddress is preserved through serialization/deserialization.
-  Add(kNullAddress, &index);
-  AddReferences(isolate, &index);
-  AddBuiltins(&index);
-  AddRuntimeFunctions(&index);
+  CopyIsolateIndependentReferences(&index);
+
+  AddIsolateDependentReferences(isolate, &index);
   AddIsolateAddresses(isolate, &index);
-  AddAccessors(&index);
   AddStubCache(isolate, &index);
   AddNativeCodeStatsCounters(isolate, &index);
   is_initialized_ = static_cast<uint32_t>(true);
@@ -108,28 +114,66 @@ const char* ExternalReferenceTable::ResolveSymbol(void* address) {
 #endif  // SYMBOLIZE_FUNCTION
 }
 
+void ExternalReferenceTable::InitializeOncePerProcess() {
+  int index = 0;
+
+  // kNullAddress is preserved through serialization/deserialization.
+  AddIsolateIndependent(kNullAddress, &index);
+  AddIsolateIndependentReferences(&index);
+  AddBuiltins(&index);
+  AddRuntimeFunctions(&index);
+  AddAccessors(&index);
+
+  CHECK_EQ(kSizeIsolateIndependent, index);
+}
+
+const char* ExternalReferenceTable::NameOfIsolateIndependentAddress(
+    Address address) {
+  for (int i = 0; i < kSizeIsolateIndependent; i++) {
+    if (ref_addr_isolate_independent_[i] == address) {
+      return ref_name_[i];
+    }
+  }
+  return "<unknown>";
+}
+
 void ExternalReferenceTable::Add(Address address, int* index) {
   ref_addr_[(*index)++] = address;
 }
 
-void ExternalReferenceTable::AddReferences(Isolate* isolate, int* index) {
+void ExternalReferenceTable::AddIsolateIndependent(Address address,
+                                                   int* index) {
+  ref_addr_isolate_independent_[(*index)++] = address;
+}
+
+void ExternalReferenceTable::AddIsolateIndependentReferences(int* index) {
   CHECK_EQ(kSpecialReferenceCount, *index);
 
 #define ADD_EXTERNAL_REFERENCE(name, desc) \
-  Add(ExternalReference::name().address(), index);
+  AddIsolateIndependent(ExternalReference::name().address(), index);
   EXTERNAL_REFERENCE_LIST(ADD_EXTERNAL_REFERENCE)
 #undef ADD_EXTERNAL_REFERENCE
 
+  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCountIsolateIndependent,
+           *index);
+}
+
+void ExternalReferenceTable::AddIsolateDependentReferences(Isolate* isolate,
+                                                           int* index) {
+  CHECK_EQ(kSizeIsolateIndependent, *index);
+
 #define ADD_EXTERNAL_REFERENCE(name, desc) \
   Add(ExternalReference::name(isolate).address(), index);
   EXTERNAL_REFERENCE_LIST_WITH_ISOLATE(ADD_EXTERNAL_REFERENCE)
 #undef ADD_EXTERNAL_REFERENCE
 
-  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCount, *index);
+  CHECK_EQ(kSizeIsolateIndependent + kExternalReferenceCountIsolateDependent,
+           *index);
 }
 
 void ExternalReferenceTable::AddBuiltins(int* index) {
-  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCount, *index);
+  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCountIsolateIndependent,
+           *index);
 
   static const Address c_builtins[] = {
 #define DEF_ENTRY(Name, ...) FUNCTION_ADDR(&Builtin_##Name),
@@ -137,16 +181,16 @@ void ExternalReferenceTable::AddBuiltins(int* index) {
 #undef DEF_ENTRY
   };
   for (Address addr : c_builtins) {
-    Add(ExternalReference::Create(addr).address(), index);
+    AddIsolateIndependent(ExternalReference::Create(addr).address(), index);
   }
 
-  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCount +
+  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCountIsolateIndependent +
                kBuiltinsReferenceCount,
            *index);
 }
 
 void ExternalReferenceTable::AddRuntimeFunctions(int* index) {
-  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCount +
+  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCountIsolateIndependent +
                kBuiltinsReferenceCount,
            *index);
 
@@ -157,33 +201,38 @@ void ExternalReferenceTable::AddRuntimeFunctions(int* index) {
   };
 
   for (Runtime::FunctionId fId : runtime_functions) {
-    Add(ExternalReference::Create(fId).address(), index);
+    AddIsolateIndependent(ExternalReference::Create(fId).address(), index);
   }
 
-  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCount +
+  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCountIsolateIndependent +
                kBuiltinsReferenceCount + kRuntimeReferenceCount,
            *index);
 }
 
+void ExternalReferenceTable::CopyIsolateIndependentReferences(int* index) {
+  CHECK_EQ(0, *index);
+
+  std::copy(ref_addr_isolate_independent_,
+            ref_addr_isolate_independent_ + kSizeIsolateIndependent, ref_addr_);
+  *index += kSizeIsolateIndependent;
+}
+
 void ExternalReferenceTable::AddIsolateAddresses(Isolate* isolate, int* index) {
-  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCount +
-               kBuiltinsReferenceCount + kRuntimeReferenceCount,
+  CHECK_EQ(kSizeIsolateIndependent + kExternalReferenceCountIsolateDependent,
            *index);
 
   for (int i = 0; i < IsolateAddressId::kIsolateAddressCount; ++i) {
     Add(isolate->get_address_from_id(static_cast<IsolateAddressId>(i)), index);
   }
 
-  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCount +
-               kBuiltinsReferenceCount + kRuntimeReferenceCount +
+  CHECK_EQ(kSizeIsolateIndependent + kExternalReferenceCountIsolateDependent +
                kIsolateAddressReferenceCount,
            *index);
 }
 
 void ExternalReferenceTable::AddAccessors(int* index) {
-  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCount +
-               kBuiltinsReferenceCount + kRuntimeReferenceCount +
-               kIsolateAddressReferenceCount,
+  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCountIsolateIndependent +
+               kBuiltinsReferenceCount + kRuntimeReferenceCount,
            *index);
 
   static const Address accessors[] = {
@@ -199,19 +248,18 @@ void ExternalReferenceTable::AddAccessors(int* index) {
   };
 
   for (Address addr : accessors) {
-    Add(addr, index);
+    AddIsolateIndependent(addr, index);
   }
 
-  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCount +
+  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCountIsolateIndependent +
                kBuiltinsReferenceCount + kRuntimeReferenceCount +
-               kIsolateAddressReferenceCount + kAccessorReferenceCount,
+               kAccessorReferenceCount,
            *index);
 }
 
 void ExternalReferenceTable::AddStubCache(Isolate* isolate, int* index) {
-  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCount +
-               kBuiltinsReferenceCount + kRuntimeReferenceCount +
-               kIsolateAddressReferenceCount + kAccessorReferenceCount,
+  CHECK_EQ(kSizeIsolateIndependent + kExternalReferenceCountIsolateDependent +
+               kIsolateAddressReferenceCount,
            *index);
 
   StubCache* load_stub_cache = isolate->load_stub_cache();
@@ -235,10 +283,8 @@ void ExternalReferenceTable::AddStubCache(Isolate* isolate, int* index) {
       index);
   Add(store_stub_cache->map_reference(StubCache::kSecondary).address(), index);
 
-  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCount +
-               kBuiltinsReferenceCount + kRuntimeReferenceCount +
-               kIsolateAddressReferenceCount + kAccessorReferenceCount +
-               kStubCacheReferenceCount,
+  CHECK_EQ(kSizeIsolateIndependent + kExternalReferenceCountIsolateDependent +
+               kIsolateAddressReferenceCount + kStubCacheReferenceCount,
            *index);
 }
 
@@ -251,10 +297,8 @@ Address ExternalReferenceTable::GetStatsCounterAddress(StatsCounter* counter) {
 
 void ExternalReferenceTable::AddNativeCodeStatsCounters(Isolate* isolate,
                                                         int* index) {
-  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCount +
-               kBuiltinsReferenceCount + kRuntimeReferenceCount +
-               kIsolateAddressReferenceCount + kAccessorReferenceCount +
-               kStubCacheReferenceCount,
+  CHECK_EQ(kSizeIsolateIndependent + kExternalReferenceCountIsolateDependent +
+               kIsolateAddressReferenceCount + kStubCacheReferenceCount,
            *index);
 
   Counters* counters = isolate->counters();
@@ -263,10 +307,9 @@ void ExternalReferenceTable::AddNativeCodeStatsCounters(Isolate* isolate,
   STATS_COUNTER_NATIVE_CODE_LIST(SC)
 #undef SC
 
-  CHECK_EQ(kSpecialReferenceCount + kExternalReferenceCount +
-               kBuiltinsReferenceCount + kRuntimeReferenceCount +
-               kIsolateAddressReferenceCount + kAccessorReferenceCount +
-               kStubCacheReferenceCount + kStatsCountersReferenceCount,
+  CHECK_EQ(kSizeIsolateIndependent + kExternalReferenceCountIsolateDependent +
+               kIsolateAddressReferenceCount + kStubCacheReferenceCount +
+               kStatsCountersReferenceCount,
            *index);
   CHECK_EQ(kSize, *index);
 }
diff --git a/chromium/v8/src/codegen/external-reference-table.h b/chromium/v8/src/codegen/external-reference-table.h
index 9f75d0fa741..0bf42477ae9 100644
--- a/chromium/v8/src/codegen/external-reference-table.h
+++ b/chromium/v8/src/codegen/external-reference-table.h
@@ -24,8 +24,10 @@ class ExternalReferenceTable {
  public:
   // For the nullptr ref, see the constructor.
   static constexpr int kSpecialReferenceCount = 1;
-  static constexpr int kExternalReferenceCount =
-      ExternalReference::kExternalReferenceCount;
+  static constexpr int kExternalReferenceCountIsolateIndependent =
+      ExternalReference::kExternalReferenceCountIsolateIndependent;
+  static constexpr int kExternalReferenceCountIsolateDependent =
+      ExternalReference::kExternalReferenceCountIsolateDependent;
   static constexpr int kBuiltinsReferenceCount =
 #define COUNT_C_BUILTIN(...) +1
       BUILTIN_LIST_C(COUNT_C_BUILTIN);
@@ -42,11 +44,14 @@ class ExternalReferenceTable {
 #define SC(...) +1
       STATS_COUNTER_NATIVE_CODE_LIST(SC);
 #undef SC
-  static constexpr int kSize =
-      kSpecialReferenceCount + kExternalReferenceCount +
+  static constexpr int kSizeIsolateIndependent =
+      kSpecialReferenceCount + kExternalReferenceCountIsolateIndependent +
       kBuiltinsReferenceCount + kRuntimeReferenceCount +
-      kIsolateAddressReferenceCount + kAccessorReferenceCount +
-      kStubCacheReferenceCount + kStatsCountersReferenceCount;
+      kAccessorReferenceCount;
+  static constexpr int kSize =
+      kSizeIsolateIndependent + kExternalReferenceCountIsolateDependent +
+      kIsolateAddressReferenceCount + kStubCacheReferenceCount +
+      kStatsCountersReferenceCount;
   static constexpr uint32_t kEntrySize =
       static_cast<uint32_t>(kSystemPointerSize);
   static constexpr uint32_t kSizeInBytes = kSize * kEntrySize + 2 * kUInt32Size;
@@ -63,6 +68,9 @@ class ExternalReferenceTable {
     return i * kEntrySize;
   }
 
+  static void InitializeOncePerProcess();
+  static const char* NameOfIsolateIndependentAddress(Address address);
+
   const char* NameFromOffset(uint32_t offset) {
     DCHECK_EQ(offset % kEntrySize, 0);
     DCHECK_LT(offset, kSizeInBytes);
@@ -76,13 +84,18 @@ class ExternalReferenceTable {
   void Init(Isolate* isolate);
 
  private:
+  static void AddIsolateIndependent(Address address, int* index);
+
+  static void AddIsolateIndependentReferences(int* index);
+  static void AddBuiltins(int* index);
+  static void AddRuntimeFunctions(int* index);
+  static void AddAccessors(int* index);
+
   void Add(Address address, int* index);
 
-  void AddReferences(Isolate* isolate, int* index);
-  void AddBuiltins(int* index);
-  void AddRuntimeFunctions(int* index);
+  void CopyIsolateIndependentReferences(int* index);
+  void AddIsolateDependentReferences(Isolate* isolate, int* index);
   void AddIsolateAddresses(Isolate* isolate, int* index);
-  void AddAccessors(int* index);
   void AddStubCache(Isolate* isolate, int* index);
 
   Address GetStatsCounterAddress(StatsCounter* counter);
diff --git a/chromium/v8/src/codegen/external-reference.cc b/chromium/v8/src/codegen/external-reference.cc
index 454b04e8935..3e91306b158 100644
--- a/chromium/v8/src/codegen/external-reference.cc
+++ b/chromium/v8/src/codegen/external-reference.cc
@@ -819,6 +819,9 @@ ExternalReference ExternalReference::search_string_raw() {
 FUNCTION_REFERENCE(jsarray_array_join_concat_to_sequential_string,
                    JSArray::ArrayJoinConcatToSequentialString)
 
+FUNCTION_REFERENCE(length_tracking_gsab_backed_typed_array_length,
+                   JSTypedArray::LengthTrackingGsabBackedTypedArrayLength)
+
 ExternalReference ExternalReference::search_string_raw_one_one() {
   return search_string_raw<const uint8_t, const uint8_t>();
 }
@@ -965,6 +968,11 @@ ExternalReference ExternalReference::cpu_features() {
   return ExternalReference(&CpuFeatures::supported_);
 }
 
+ExternalReference ExternalReference::promise_hook_flags_address(
+    Isolate* isolate) {
+  return ExternalReference(isolate->promise_hook_flags_address());
+}
+
 ExternalReference ExternalReference::promise_hook_address(Isolate* isolate) {
   return ExternalReference(isolate->promise_hook_address());
 }
@@ -974,21 +982,6 @@ ExternalReference ExternalReference::async_event_delegate_address(
   return ExternalReference(isolate->async_event_delegate_address());
 }
 
-ExternalReference
-ExternalReference::promise_hook_or_async_event_delegate_address(
-    Isolate* isolate) {
-  return ExternalReference(
-      isolate->promise_hook_or_async_event_delegate_address());
-}
-
-ExternalReference ExternalReference::
-    promise_hook_or_debug_is_active_or_async_event_delegate_address(
-        Isolate* isolate) {
-  return ExternalReference(
-      isolate
-          ->promise_hook_or_debug_is_active_or_async_event_delegate_address());
-}
-
 ExternalReference ExternalReference::debug_execution_mode_address(
     Isolate* isolate) {
   return ExternalReference(isolate->debug_execution_mode_address());
@@ -1027,11 +1020,6 @@ ExternalReference ExternalReference::debug_suspended_generator_address(
   return ExternalReference(isolate->debug()->suspended_generator_address());
 }
 
-ExternalReference ExternalReference::debug_restart_fp_address(
-    Isolate* isolate) {
-  return ExternalReference(isolate->debug()->restart_fp_address());
-}
-
 ExternalReference ExternalReference::fast_c_call_caller_fp_address(
     Isolate* isolate) {
   return ExternalReference(
diff --git a/chromium/v8/src/codegen/external-reference.h b/chromium/v8/src/codegen/external-reference.h
index f53db401c9e..f75a5c694ad 100644
--- a/chromium/v8/src/codegen/external-reference.h
+++ b/chromium/v8/src/codegen/external-reference.h
@@ -50,13 +50,9 @@ class StatsCounter;
   V(handle_scope_limit_address, "HandleScope::limit")                          \
   V(scheduled_exception_address, "Isolate::scheduled_exception")               \
   V(address_of_pending_message_obj, "address_of_pending_message_obj")          \
+  V(promise_hook_flags_address, "Isolate::promise_hook_flags_address()")       \
   V(promise_hook_address, "Isolate::promise_hook_address()")                   \
   V(async_event_delegate_address, "Isolate::async_event_delegate_address()")   \
-  V(promise_hook_or_async_event_delegate_address,                              \
-    "Isolate::promise_hook_or_async_event_delegate_address()")                 \
-  V(promise_hook_or_debug_is_active_or_async_event_delegate_address,           \
-    "Isolate::promise_hook_or_debug_is_active_or_async_event_delegate_"        \
-    "address()")                                                               \
   V(debug_execution_mode_address, "Isolate::debug_execution_mode_address()")   \
   V(debug_is_active_address, "Debug::is_active_address()")                     \
   V(debug_hook_on_function_call_address,                                       \
@@ -66,7 +62,6 @@ class StatsCounter;
   V(is_profiling_address, "Isolate::is_profiling")                             \
   V(debug_suspended_generator_address,                                         \
     "Debug::step_suspended_generator_address()")                               \
-  V(debug_restart_fp_address, "Debug::restart_fp_address()")                   \
   V(fast_c_call_caller_fp_address,                                             \
     "IsolateData::fast_c_call_caller_fp_address")                              \
   V(fast_c_call_caller_pc_address,                                             \
@@ -174,6 +169,8 @@ class StatsCounter;
   V(jsarray_array_join_concat_to_sequential_string,                            \
     "jsarray_array_join_concat_to_sequential_string")                          \
   V(jsreceiver_create_identity_hash, "jsreceiver_create_identity_hash")        \
+  V(length_tracking_gsab_backed_typed_array_length,                            \
+    "LengthTrackingGsabBackedTypedArrayLength")                                \
   V(libc_memchr_function, "libc_memchr")                                       \
   V(libc_memcpy_function, "libc_memcpy")                                       \
   V(libc_memmove_function, "libc_memmove")                                     \
@@ -342,10 +339,11 @@ class ExternalReference {
     PROFILING_GETTER_CALL
   };
 
-  static constexpr int kExternalReferenceCount =
 #define COUNT_EXTERNAL_REFERENCE(name, desc) +1
-      EXTERNAL_REFERENCE_LIST(COUNT_EXTERNAL_REFERENCE)
-          EXTERNAL_REFERENCE_LIST_WITH_ISOLATE(COUNT_EXTERNAL_REFERENCE);
+  static constexpr int kExternalReferenceCountIsolateIndependent =
+      EXTERNAL_REFERENCE_LIST(COUNT_EXTERNAL_REFERENCE);
+  static constexpr int kExternalReferenceCountIsolateDependent =
+      EXTERNAL_REFERENCE_LIST_WITH_ISOLATE(COUNT_EXTERNAL_REFERENCE);
 #undef COUNT_EXTERNAL_REFERENCE
 
   ExternalReference() : address_(kNullAddress) {}
diff --git a/chromium/v8/src/codegen/handler-table.h b/chromium/v8/src/codegen/handler-table.h
index e1626e2be50..5b83bf4a696 100644
--- a/chromium/v8/src/codegen/handler-table.h
+++ b/chromium/v8/src/codegen/handler-table.h
@@ -97,8 +97,8 @@ class V8_EXPORT_PRIVATE HandlerTable {
   int NumberOfReturnEntries() const;
 
 #ifdef ENABLE_DISASSEMBLER
-  void HandlerTableRangePrint(std::ostream& os);   // NOLINT
-  void HandlerTableReturnPrint(std::ostream& os);  // NOLINT
+  void HandlerTableRangePrint(std::ostream& os);
+  void HandlerTableReturnPrint(std::ostream& os);
 #endif
 
  private:
diff --git a/chromium/v8/src/codegen/ia32/assembler-ia32.cc b/chromium/v8/src/codegen/ia32/assembler-ia32.cc
index 809df1daef0..688b038e917 100644
--- a/chromium/v8/src/codegen/ia32/assembler-ia32.cc
+++ b/chromium/v8/src/codegen/ia32/assembler-ia32.cc
@@ -138,39 +138,38 @@ void CpuFeatures::ProbeImpl(bool cross_compile) {
   // Only use statically determined features for cross compile (snapshot).
   if (cross_compile) return;
 
-  // To deal with any combination of flags (e.g. --no-enable-sse4-1
-  // --enable-sse-4-2), we start checking from the "highest" supported
-  // extension, for each extension, enable if newer extension is supported.
-  if (cpu.has_avx2() && FLAG_enable_avx2 && IsSupported(AVX)) {
-    supported_ |= 1u << AVX2;
+  if (cpu.has_sse42()) SetSupported(SSE4_2);
+  if (cpu.has_sse41()) SetSupported(SSE4_1);
+  if (cpu.has_ssse3()) SetSupported(SSSE3);
+  if (cpu.has_sse3()) SetSupported(SSE3);
+  if (cpu.has_avx() && cpu.has_osxsave() && OSHasAVXSupport()) {
+    SetSupported(AVX);
+    if (cpu.has_avx2()) SetSupported(AVX2);
+    if (cpu.has_fma3()) SetSupported(FMA3);
   }
-  if (cpu.has_fma3() && FLAG_enable_fma3 && cpu.has_osxsave() &&
-      OSHasAVXSupport()) {
-    supported_ |= 1u << FMA3;
-  }
-  if ((cpu.has_avx() && FLAG_enable_avx && cpu.has_osxsave() &&
-       OSHasAVXSupport()) ||
-      IsSupported(AVX2) || IsSupported(FMA3)) {
-    supported_ |= 1u << AVX;
-  }
-  if ((cpu.has_sse42() && FLAG_enable_sse4_2) || IsSupported(AVX))
-    supported_ |= 1u << SSE4_2;
-  if ((cpu.has_sse41() && FLAG_enable_sse4_1) || IsSupported(SSE4_2))
-    supported_ |= 1u << SSE4_1;
-  if ((cpu.has_ssse3() && FLAG_enable_ssse3) || IsSupported(SSE4_1))
-    supported_ |= 1u << SSSE3;
-  if ((cpu.has_sse3() && FLAG_enable_sse3) || IsSupported(SSSE3))
-    supported_ |= 1u << SSE3;
-  if (cpu.has_bmi1() && FLAG_enable_bmi1) supported_ |= 1u << BMI1;
-  if (cpu.has_bmi2() && FLAG_enable_bmi2) supported_ |= 1u << BMI2;
-  if (cpu.has_lzcnt() && FLAG_enable_lzcnt) supported_ |= 1u << LZCNT;
-  if (cpu.has_popcnt() && FLAG_enable_popcnt) supported_ |= 1u << POPCNT;
+
+  if (cpu.has_bmi1() && FLAG_enable_bmi1) SetSupported(BMI1);
+  if (cpu.has_bmi2() && FLAG_enable_bmi2) SetSupported(BMI2);
+  if (cpu.has_lzcnt() && FLAG_enable_lzcnt) SetSupported(LZCNT);
+  if (cpu.has_popcnt() && FLAG_enable_popcnt) SetSupported(POPCNT);
   if (strcmp(FLAG_mcpu, "auto") == 0) {
-    if (cpu.is_atom()) supported_ |= 1u << ATOM;
+    if (cpu.is_atom()) SetSupported(ATOM);
   } else if (strcmp(FLAG_mcpu, "atom") == 0) {
-    supported_ |= 1u << ATOM;
+    SetSupported(ATOM);
   }
 
+  // Ensure that supported cpu features make sense. E.g. it is wrong to support
+  // AVX but not SSE4_2, if we have --enable-avx and --no-enable-sse4-2, the
+  // code above would set AVX to supported, and SSE4_2 to unsupported, then the
+  // checks below will set AVX to unsupported.
+  if (!FLAG_enable_sse3) SetUnsupported(SSE3);
+  if (!FLAG_enable_ssse3 || !IsSupported(SSE3)) SetUnsupported(SSSE3);
+  if (!FLAG_enable_sse4_1 || !IsSupported(SSSE3)) SetUnsupported(SSE4_1);
+  if (!FLAG_enable_sse4_2 || !IsSupported(SSE4_1)) SetUnsupported(SSE4_2);
+  if (!FLAG_enable_avx || !IsSupported(SSE4_2)) SetUnsupported(AVX);
+  if (!FLAG_enable_avx2 || !IsSupported(AVX)) SetUnsupported(AVX2);
+  if (!FLAG_enable_fma3 || !IsSupported(AVX)) SetUnsupported(FMA3);
+
   // Set a static value on whether Simd is supported.
   // This variable is only used for certain archs to query SupportWasmSimd128()
   // at runtime in builtins using an extern ref. Other callers should use
@@ -2489,6 +2488,13 @@ void Assembler::movhlps(XMMRegister dst, XMMRegister src) {
   emit_sse_operand(dst, src);
 }
 
+void Assembler::movlhps(XMMRegister dst, XMMRegister src) {
+  EnsureSpace ensure_space(this);
+  EMIT(0x0F);
+  EMIT(0x16);
+  emit_sse_operand(dst, src);
+}
+
 void Assembler::movlps(XMMRegister dst, Operand src) {
   EnsureSpace ensure_space(this);
   EMIT(0x0F);
@@ -2980,6 +2986,10 @@ void Assembler::vmovhlps(XMMRegister dst, XMMRegister src1, XMMRegister src2) {
   vinstr(0x12, dst, src1, src2, kNone, k0F, kWIG);
 }
 
+void Assembler::vmovlhps(XMMRegister dst, XMMRegister src1, XMMRegister src2) {
+  vinstr(0x16, dst, src1, src2, kNone, k0F, kWIG);
+}
+
 void Assembler::vmovlps(XMMRegister dst, XMMRegister src1, Operand src2) {
   vinstr(0x12, dst, src1, src2, kNone, k0F, kWIG);
 }
@@ -3276,9 +3286,9 @@ void Assembler::sse4_instr(XMMRegister dst, Operand src, byte prefix,
 }
 
 void Assembler::vinstr(byte op, XMMRegister dst, XMMRegister src1,
-                       XMMRegister src2, SIMDPrefix pp, LeadingOpcode m,
-                       VexW w) {
-  DCHECK(IsEnabled(AVX));
+                       XMMRegister src2, SIMDPrefix pp, LeadingOpcode m, VexW w,
+                       CpuFeature feature) {
+  DCHECK(IsEnabled(feature));
   EnsureSpace ensure_space(this);
   emit_vex_prefix(src1, kL128, pp, m, w);
   EMIT(op);
@@ -3286,8 +3296,9 @@ void Assembler::vinstr(byte op, XMMRegister dst, XMMRegister src1,
 }
 
 void Assembler::vinstr(byte op, XMMRegister dst, XMMRegister src1, Operand src2,
-                       SIMDPrefix pp, LeadingOpcode m, VexW w) {
-  DCHECK(IsEnabled(AVX));
+                       SIMDPrefix pp, LeadingOpcode m, VexW w,
+                       CpuFeature feature) {
+  DCHECK(IsEnabled(feature));
   EnsureSpace ensure_space(this);
   emit_vex_prefix(src1, kL128, pp, m, w);
   EMIT(op);
diff --git a/chromium/v8/src/codegen/ia32/assembler-ia32.h b/chromium/v8/src/codegen/ia32/assembler-ia32.h
index 2a8fd3ee28b..806d17a2d4d 100644
--- a/chromium/v8/src/codegen/ia32/assembler-ia32.h
+++ b/chromium/v8/src/codegen/ia32/assembler-ia32.h
@@ -868,6 +868,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   void shufpd(XMMRegister dst, XMMRegister src, byte imm8);
 
   void movhlps(XMMRegister dst, XMMRegister src);
+  void movlhps(XMMRegister dst, XMMRegister src);
   void movlps(XMMRegister dst, Operand src);
   void movlps(Operand dst, XMMRegister src);
   void movhps(XMMRegister dst, Operand src);
@@ -1398,6 +1399,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   void vshufpd(XMMRegister dst, XMMRegister src1, Operand src2, byte imm8);
 
   void vmovhlps(XMMRegister dst, XMMRegister src1, XMMRegister src2);
+  void vmovlhps(XMMRegister dst, XMMRegister src1, XMMRegister src2);
   void vmovlps(XMMRegister dst, XMMRegister src1, Operand src2);
   void vmovlps(Operand dst, XMMRegister src);
   void vmovhps(XMMRegister dst, XMMRegister src1, Operand src2);
@@ -1516,6 +1518,9 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   void vmovshdup(XMMRegister dst, XMMRegister src) {
     vinstr(0x16, dst, xmm0, src, kF3, k0F, kWIG);
   }
+  void vbroadcastss(XMMRegister dst, XMMRegister src) {
+    vinstr(0x18, dst, xmm0, src, k66, k0F38, kW0, AVX2);
+  }
   void vbroadcastss(XMMRegister dst, Operand src) {
     vinstr(0x18, dst, xmm0, src, k66, k0F38, kW0);
   }
@@ -1892,9 +1897,9 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   void sse4_instr(XMMRegister dst, Operand src, byte prefix, byte escape1,
                   byte escape2, byte opcode);
   void vinstr(byte op, XMMRegister dst, XMMRegister src1, XMMRegister src2,
-              SIMDPrefix pp, LeadingOpcode m, VexW w);
+              SIMDPrefix pp, LeadingOpcode m, VexW w, CpuFeature = AVX);
   void vinstr(byte op, XMMRegister dst, XMMRegister src1, Operand src2,
-              SIMDPrefix pp, LeadingOpcode m, VexW w);
+              SIMDPrefix pp, LeadingOpcode m, VexW w, CpuFeature = AVX);
   // Most BMI instructions are similar.
   void bmi1(byte op, Register reg, Register vreg, Operand rm);
   void bmi2(SIMDPrefix pp, byte op, Register reg, Register vreg, Operand rm);
@@ -1933,10 +1938,10 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
 // checks that we did not generate too much.
 class EnsureSpace {
  public:
-  explicit EnsureSpace(Assembler* assembler) : assembler_(assembler) {
-    if (assembler_->buffer_overflow()) assembler_->GrowBuffer();
+  explicit V8_INLINE EnsureSpace(Assembler* assembler) : assembler_(assembler) {
+    if (V8_UNLIKELY(assembler_->buffer_overflow())) assembler_->GrowBuffer();
 #ifdef DEBUG
-    space_before_ = assembler_->available_space();
+    space_before_ = assembler->available_space();
 #endif
   }
 
@@ -1948,7 +1953,7 @@ class EnsureSpace {
 #endif
 
  private:
-  Assembler* assembler_;
+  Assembler* const assembler_;
 #ifdef DEBUG
   int space_before_;
 #endif
diff --git a/chromium/v8/src/codegen/ia32/interface-descriptors-ia32-inl.h b/chromium/v8/src/codegen/ia32/interface-descriptors-ia32-inl.h
new file mode 100644
index 00000000000..d079dfd7256
--- /dev/null
+++ b/chromium/v8/src/codegen/ia32/interface-descriptors-ia32-inl.h
@@ -0,0 +1,267 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_CODEGEN_IA32_INTERFACE_DESCRIPTORS_IA32_INL_H_
+#define V8_CODEGEN_IA32_INTERFACE_DESCRIPTORS_IA32_INL_H_
+
+#if V8_TARGET_ARCH_IA32
+
+#include "src/codegen/interface-descriptors.h"
+
+namespace v8 {
+namespace internal {
+
+constexpr auto CallInterfaceDescriptor::DefaultRegisterArray() {
+  auto registers = RegisterArray(eax, ecx, edx, edi);
+  STATIC_ASSERT(registers.size() == kMaxBuiltinRegisterParams);
+  return registers;
+}
+
+// static
+constexpr auto RecordWriteDescriptor::registers() {
+  return RegisterArray(ecx, edx, esi, edi, kReturnRegister0);
+}
+
+// static
+constexpr auto DynamicCheckMapsDescriptor::registers() {
+  return RegisterArray(eax, ecx, edx, edi, esi);
+}
+
+// static
+constexpr auto EphemeronKeyBarrierDescriptor::registers() {
+  return RegisterArray(ecx, edx, esi, edi, kReturnRegister0);
+}
+
+// static
+constexpr Register LoadDescriptor::ReceiverRegister() { return edx; }
+// static
+constexpr Register LoadDescriptor::NameRegister() { return ecx; }
+// static
+constexpr Register LoadDescriptor::SlotRegister() { return eax; }
+
+// static
+constexpr Register LoadWithVectorDescriptor::VectorRegister() { return no_reg; }
+
+// static
+constexpr Register
+LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
+  return edi;
+}
+
+// static
+constexpr Register StoreDescriptor::ReceiverRegister() { return edx; }
+// static
+constexpr Register StoreDescriptor::NameRegister() { return ecx; }
+// static
+constexpr Register StoreDescriptor::ValueRegister() { return no_reg; }
+// static
+constexpr Register StoreDescriptor::SlotRegister() { return no_reg; }
+
+// static
+constexpr Register StoreWithVectorDescriptor::VectorRegister() {
+  return no_reg;
+}
+
+// static
+constexpr Register StoreTransitionDescriptor::MapRegister() { return edi; }
+
+// static
+constexpr Register ApiGetterDescriptor::HolderRegister() { return ecx; }
+// static
+constexpr Register ApiGetterDescriptor::CallbackRegister() { return eax; }
+
+// static
+constexpr Register GrowArrayElementsDescriptor::ObjectRegister() { return eax; }
+// static
+constexpr Register GrowArrayElementsDescriptor::KeyRegister() { return ecx; }
+
+// static
+constexpr Register BaselineLeaveFrameDescriptor::ParamsSizeRegister() {
+  return esi;
+}
+// static
+constexpr Register BaselineLeaveFrameDescriptor::WeightRegister() {
+  return edi;
+}
+
+// static
+constexpr Register TypeConversionDescriptor::ArgumentRegister() { return eax; }
+
+// static
+constexpr auto TypeofDescriptor::registers() { return RegisterArray(ecx); }
+
+// static
+constexpr auto CallTrampolineDescriptor::registers() {
+  // eax : number of arguments
+  // edi : the target to call
+  return RegisterArray(edi, eax);
+}
+
+// static
+constexpr auto CallVarargsDescriptor::registers() {
+  // eax : number of arguments (on the stack, not including receiver)
+  // edi : the target to call
+  // ecx : arguments list length (untagged)
+  // On the stack : arguments list (FixedArray)
+  return RegisterArray(edi, eax, ecx);
+}
+
+// static
+constexpr auto CallForwardVarargsDescriptor::registers() {
+  // eax : number of arguments
+  // ecx : start index (to support rest parameters)
+  // edi : the target to call
+  return RegisterArray(edi, eax, ecx);
+}
+
+// static
+constexpr auto CallFunctionTemplateDescriptor::registers() {
+  // edx : function template info
+  // ecx : number of arguments (on the stack, not including receiver)
+  return RegisterArray(edx, ecx);
+}
+
+// static
+constexpr auto CallWithSpreadDescriptor::registers() {
+  // eax : number of arguments (on the stack, not including receiver)
+  // edi : the target to call
+  // ecx : the object to spread
+  return RegisterArray(edi, eax, ecx);
+}
+
+// static
+constexpr auto CallWithArrayLikeDescriptor::registers() {
+  // edi : the target to call
+  // edx : the arguments list
+  return RegisterArray(edi, edx);
+}
+
+// static
+constexpr auto ConstructVarargsDescriptor::registers() {
+  // eax : number of arguments (on the stack, not including receiver)
+  // edi : the target to call
+  // edx : the new target
+  // ecx : arguments list length (untagged)
+  // On the stack : arguments list (FixedArray)
+  return RegisterArray(edi, edx, eax, ecx);
+}
+
+// static
+constexpr auto ConstructForwardVarargsDescriptor::registers() {
+  // eax : number of arguments
+  // edx : the new target
+  // ecx : start index (to support rest parameters)
+  // edi : the target to call
+  return RegisterArray(edi, edx, eax, ecx);
+}
+
+// static
+constexpr auto ConstructWithSpreadDescriptor::registers() {
+  // eax : number of arguments (on the stack, not including receiver)
+  // edi : the target to call
+  // edx : the new target
+  // ecx : the object to spread
+  return RegisterArray(edi, edx, eax, ecx);
+}
+
+// static
+constexpr auto ConstructWithArrayLikeDescriptor::registers() {
+  // edi : the target to call
+  // edx : the new target
+  // ecx : the arguments list
+  return RegisterArray(edi, edx, ecx);
+}
+
+// static
+constexpr auto ConstructStubDescriptor::registers() {
+  // eax : number of arguments
+  // edx : the new target
+  // edi : the target to call
+  // ecx : allocation site or undefined
+  // TODO(jgruber): Remove the unused allocation site parameter.
+  return RegisterArray(edi, edx, eax, ecx);
+}
+
+// static
+constexpr auto AbortDescriptor::registers() { return RegisterArray(edx); }
+
+// static
+constexpr auto CompareDescriptor::registers() {
+  return RegisterArray(edx, eax);
+}
+
+// static
+constexpr auto Compare_BaselineDescriptor::registers() {
+  return RegisterArray(edx, eax, ecx);
+}
+
+// static
+constexpr auto BinaryOpDescriptor::registers() {
+  return RegisterArray(edx, eax);
+}
+
+// static
+constexpr auto BinaryOp_BaselineDescriptor::registers() {
+  return RegisterArray(edx, eax, ecx);
+}
+
+// static
+constexpr auto ApiCallbackDescriptor::registers() {
+  return RegisterArray(edx,   // kApiFunctionAddress
+                       ecx,   // kArgc
+                       eax,   // kCallData
+                       edi);  // kHolder
+}
+
+// static
+constexpr auto InterpreterDispatchDescriptor::registers() {
+  return RegisterArray(
+      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
+      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister);
+}
+
+// static
+constexpr auto InterpreterPushArgsThenCallDescriptor::registers() {
+  return RegisterArray(eax,   // argument count (not including receiver)
+                       ecx,   // address of first argument
+                       edi);  // the target callable to be call
+}
+
+// static
+constexpr auto InterpreterPushArgsThenConstructDescriptor::registers() {
+  return RegisterArray(eax,   // argument count (not including receiver)
+                       ecx);  // address of first argument
+}
+
+// static
+constexpr auto ResumeGeneratorDescriptor::registers() {
+  return RegisterArray(eax,   // the value to pass to the generator
+                       edx);  // the JSGeneratorObject to resume
+}
+
+// static
+constexpr auto RunMicrotasksEntryDescriptor::registers() {
+  return RegisterArray();
+}
+
+// static
+constexpr auto WasmFloat32ToNumberDescriptor::registers() {
+  // Work around using eax, whose register code is 0, and leads to the FP
+  // parameter being passed via xmm0, which is not allocatable on ia32.
+  return RegisterArray(ecx);
+}
+
+// static
+constexpr auto WasmFloat64ToNumberDescriptor::registers() {
+  // Work around using eax, whose register code is 0, and leads to the FP
+  // parameter being passed via xmm0, which is not allocatable on ia32.
+  return RegisterArray(ecx);
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TARGET_ARCH_IA32
+
+#endif  // V8_CODEGEN_IA32_INTERFACE_DESCRIPTORS_IA32_INL_H_
diff --git a/chromium/v8/src/codegen/ia32/interface-descriptors-ia32.cc b/chromium/v8/src/codegen/ia32/interface-descriptors-ia32.cc
deleted file mode 100644
index fd76e01590b..00000000000
--- a/chromium/v8/src/codegen/ia32/interface-descriptors-ia32.cc
+++ /dev/null
@@ -1,318 +0,0 @@
-// Copyright 2012 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#if V8_TARGET_ARCH_IA32
-
-#include "src/codegen/interface-descriptors.h"
-
-#include "src/execution/frames.h"
-
-namespace v8 {
-namespace internal {
-
-const Register CallInterfaceDescriptor::ContextRegister() { return esi; }
-
-void CallInterfaceDescriptor::DefaultInitializePlatformSpecific(
-    CallInterfaceDescriptorData* data, int register_parameter_count) {
-  constexpr Register default_stub_registers[] = {eax, ecx, edx, edi};
-  STATIC_ASSERT(arraysize(default_stub_registers) == kMaxBuiltinRegisterParams);
-  CHECK_LE(static_cast<size_t>(register_parameter_count),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(register_parameter_count,
-                                   default_stub_registers);
-}
-
-void RecordWriteDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  static const Register default_stub_registers[] = {ecx, edx, esi, edi,
-                                                    kReturnRegister0};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void DynamicCheckMapsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register default_stub_registers[] = {eax, ecx, edx, edi, esi};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void EphemeronKeyBarrierDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  static const Register default_stub_registers[] = {ecx, edx, esi, edi,
-                                                    kReturnRegister0};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-const Register LoadDescriptor::ReceiverRegister() { return edx; }
-const Register LoadDescriptor::NameRegister() { return ecx; }
-const Register LoadDescriptor::SlotRegister() { return eax; }
-
-const Register LoadWithVectorDescriptor::VectorRegister() { return no_reg; }
-
-const Register
-LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
-  return edi;
-}
-
-const Register StoreDescriptor::ReceiverRegister() { return edx; }
-const Register StoreDescriptor::NameRegister() { return ecx; }
-const Register StoreDescriptor::ValueRegister() { return no_reg; }
-const Register StoreDescriptor::SlotRegister() { return no_reg; }
-
-const Register StoreWithVectorDescriptor::VectorRegister() { return no_reg; }
-
-const Register StoreTransitionDescriptor::SlotRegister() { return no_reg; }
-const Register StoreTransitionDescriptor::VectorRegister() { return no_reg; }
-const Register StoreTransitionDescriptor::MapRegister() { return edi; }
-
-const Register ApiGetterDescriptor::HolderRegister() { return ecx; }
-const Register ApiGetterDescriptor::CallbackRegister() { return eax; }
-
-const Register GrowArrayElementsDescriptor::ObjectRegister() { return eax; }
-const Register GrowArrayElementsDescriptor::KeyRegister() { return ecx; }
-
-const Register BaselineLeaveFrameDescriptor::ParamsSizeRegister() {
-  return esi;
-}
-const Register BaselineLeaveFrameDescriptor::WeightRegister() { return edi; }
-
-// static
-const Register TypeConversionDescriptor::ArgumentRegister() { return eax; }
-
-void TypeofDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {ecx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // eax : number of arguments
-  // edi : the target to call
-  Register registers[] = {edi, eax};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // eax : number of arguments (on the stack, not including receiver)
-  // edi : the target to call
-  // ecx : arguments list length (untagged)
-  // On the stack : arguments list (FixedArray)
-  Register registers[] = {edi, eax, ecx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // eax : number of arguments
-  // ecx : start index (to support rest parameters)
-  // edi : the target to call
-  Register registers[] = {edi, eax, ecx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallFunctionTemplateDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // edx : function template info
-  // ecx : number of arguments (on the stack, not including receiver)
-  Register registers[] = {edx, ecx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // eax : number of arguments (on the stack, not including receiver)
-  // edi : the target to call
-  // ecx : the object to spread
-  Register registers[] = {edi, eax, ecx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // edi : the target to call
-  // edx : the arguments list
-  Register registers[] = {edi, edx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // eax : number of arguments (on the stack, not including receiver)
-  // edi : the target to call
-  // edx : the new target
-  // ecx : arguments list length (untagged)
-  // On the stack : arguments list (FixedArray)
-  Register registers[] = {edi, edx, eax, ecx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // eax : number of arguments
-  // edx : the new target
-  // ecx : start index (to support rest parameters)
-  // edi : the target to call
-  Register registers[] = {edi, edx, eax, ecx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // eax : number of arguments (on the stack, not including receiver)
-  // edi : the target to call
-  // edx : the new target
-  // ecx : the object to spread
-  Register registers[] = {edi, edx, eax, ecx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // edi : the target to call
-  // edx : the new target
-  // ecx : the arguments list
-  Register registers[] = {edi, edx, ecx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructStubDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // eax : number of arguments
-  // edx : the new target
-  // edi : the target to call
-  // ecx : allocation site or undefined
-  // TODO(jgruber): Remove the unused allocation site parameter.
-  Register registers[] = {edi, edx, eax, ecx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void AbortDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {edx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CompareDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {edx, eax};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void Compare_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {edx, eax, ecx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void BinaryOpDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {edx, eax};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void BinaryOp_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {edx, eax, ecx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ApiCallbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      edx,  // kApiFunctionAddress
-      ecx,  // kArgc
-      eax,  // kCallData
-      edi,  // kHolder
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterDispatchDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
-      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenCallDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      eax,  // argument count (not including receiver)
-      ecx,  // address of first argument
-      edi   // the target callable to be call
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenConstructDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      eax,  // argument count (not including receiver)
-      ecx,  // address of first argument
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ResumeGeneratorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      eax,  // the value to pass to the generator
-      edx   // the JSGeneratorObject to resume
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void FrameDropperTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      eax,  // loaded new FP
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void RunMicrotasksEntryDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  data->InitializePlatformSpecific(0, nullptr);
-}
-
-void WasmFloat32ToNumberDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // Work around using eax, whose register code is 0, and leads to the FP
-  // parameter being passed via xmm0, which is not allocatable on ia32.
-  Register registers[] = {ecx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void WasmFloat64ToNumberDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // Work around using eax, whose register code is 0, and leads to the FP
-  // parameter being passed via xmm0, which is not allocatable on ia32.
-  Register registers[] = {ecx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_TARGET_ARCH_IA32
diff --git a/chromium/v8/src/codegen/ia32/macro-assembler-ia32.cc b/chromium/v8/src/codegen/ia32/macro-assembler-ia32.cc
index 9892eb9470e..7c8af3fde00 100644
--- a/chromium/v8/src/codegen/ia32/macro-assembler-ia32.cc
+++ b/chromium/v8/src/codegen/ia32/macro-assembler-ia32.cc
@@ -19,7 +19,7 @@
 #include "src/codegen/external-reference.h"
 #include "src/codegen/ia32/assembler-ia32.h"
 #include "src/codegen/ia32/register-ia32.h"
-#include "src/codegen/interface-descriptors.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/label.h"
 #include "src/codegen/macro-assembler.h"
 #include "src/codegen/register.h"
@@ -294,7 +294,7 @@ int TurboAssembler::RequiredStackSizeForCallerSaved(SaveFPRegsMode fp_mode,
     }
   }
 
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     // Count all XMM registers except XMM0.
     bytes += kDoubleSize * (XMMRegister::kNumRegisters - 1);
   }
@@ -316,7 +316,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
     }
   }
 
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     // Save all XMM registers except XMM0.
     int delta = kDoubleSize * (XMMRegister::kNumRegisters - 1);
     AllocateStackSpace(delta);
@@ -333,7 +333,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
 int TurboAssembler::PopCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
                                    Register exclusion2, Register exclusion3) {
   int bytes = 0;
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     // Restore all XMM registers except XMM0.
     int delta = kDoubleSize * (XMMRegister::kNumRegisters - 1);
     for (int i = XMMRegister::kNumRegisters - 1; i > 0; i--) {
@@ -365,7 +365,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   Label done;
 
   // Skip barrier if writing a smi.
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     JumpIfSmi(value, &done);
   }
 
@@ -374,7 +374,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   DCHECK(IsAligned(offset, kTaggedSize));
 
   lea(dst, FieldOperand(object, offset));
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label ok;
     test_b(dst, Immediate(kTaggedSize - 1));
     j(zero, &ok, Label::kNear);
@@ -383,13 +383,13 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   }
 
   RecordWrite(object, dst, value, save_fp, remembered_set_action,
-              OMIT_SMI_CHECK);
+              SmiCheck::kOmit);
 
   bind(&done);
 
   // Clobber clobbered input registers when running with the debug-code flag
   // turned on to provoke errors.
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     mov(value, Immediate(bit_cast<int32_t>(kZapValue)));
     mov(dst, Immediate(bit_cast<int32_t>(kZapValue)));
   }
@@ -511,13 +511,13 @@ void MacroAssembler::RecordWrite(Register object, Register address,
   DCHECK(value != address);
   AssertNotSmi(object);
 
-  if ((remembered_set_action == OMIT_REMEMBERED_SET &&
+  if ((remembered_set_action == RememberedSetAction::kOmit &&
        !FLAG_incremental_marking) ||
       FLAG_disable_write_barriers) {
     return;
   }
 
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label ok;
     cmp(value, Operand(address, 0));
     j(equal, &ok, Label::kNear);
@@ -529,7 +529,7 @@ void MacroAssembler::RecordWrite(Register object, Register address,
   // catch stores of Smis and stores into young gen.
   Label done;
 
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     // Skip barrier if writing a smi.
     JumpIfSmi(value, &done, Label::kNear);
   }
@@ -549,25 +549,12 @@ void MacroAssembler::RecordWrite(Register object, Register address,
 
   // Clobber clobbered registers when running with the debug-code flag
   // turned on to provoke errors.
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     mov(address, Immediate(bit_cast<int32_t>(kZapValue)));
     mov(value, Immediate(bit_cast<int32_t>(kZapValue)));
   }
 }
 
-void MacroAssembler::MaybeDropFrames() {
-  // Check whether we need to drop frames to restart a function on the stack.
-  Label dont_drop;
-  ExternalReference restart_fp =
-      ExternalReference::debug_restart_fp_address(isolate());
-  mov(eax, ExternalReferenceAsOperand(restart_fp, eax));
-  test(eax, eax);
-  j(zero, &dont_drop, Label::kNear);
-
-  Jump(BUILTIN_CODE(isolate(), FrameDropperTrampoline), RelocInfo::CODE_TARGET);
-  bind(&dont_drop);
-}
-
 void TurboAssembler::Cvtsi2ss(XMMRegister dst, Operand src) {
   xorps(dst, dst);
   cvtsi2ss(dst, src);
@@ -1029,14 +1016,14 @@ void MacroAssembler::CmpInstanceTypeRange(Register map, Register scratch,
 }
 
 void MacroAssembler::AssertSmi(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     test(object, Immediate(kSmiTagMask));
     Check(equal, AbortReason::kOperandIsNotASmi);
   }
 }
 
 void MacroAssembler::AssertConstructor(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     test(object, Immediate(kSmiTagMask));
     Check(not_equal, AbortReason::kOperandIsASmiAndNotAConstructor);
     Push(object);
@@ -1049,7 +1036,7 @@ void MacroAssembler::AssertConstructor(Register object) {
 }
 
 void MacroAssembler::AssertFunction(Register object, Register scratch) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     test(object, Immediate(kSmiTagMask));
     Check(not_equal, AbortReason::kOperandIsASmiAndNotAFunction);
     Push(object);
@@ -1062,7 +1049,7 @@ void MacroAssembler::AssertFunction(Register object, Register scratch) {
 }
 
 void MacroAssembler::AssertBoundFunction(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     test(object, Immediate(kSmiTagMask));
     Check(not_equal, AbortReason::kOperandIsASmiAndNotABoundFunction);
     Push(object);
@@ -1073,7 +1060,7 @@ void MacroAssembler::AssertBoundFunction(Register object) {
 }
 
 void MacroAssembler::AssertGeneratorObject(Register object) {
-  if (!emit_debug_code()) return;
+  if (!FLAG_debug_code) return;
 
   test(object, Immediate(kSmiTagMask));
   Check(not_equal, AbortReason::kOperandIsASmiAndNotAGeneratorObject);
@@ -1105,7 +1092,7 @@ void MacroAssembler::AssertGeneratorObject(Register object) {
 
 void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
                                                      Register scratch) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label done_checking;
     AssertNotSmi(object);
     CompareRoot(object, scratch, RootIndex::kUndefinedValue);
@@ -1118,7 +1105,7 @@ void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
 }
 
 void MacroAssembler::AssertNotSmi(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     test(object, Immediate(kSmiTagMask));
     Check(not_equal, AbortReason::kOperandIsASmi);
   }
@@ -1147,7 +1134,7 @@ void TurboAssembler::EnterFrame(StackFrame::Type type) {
 }
 
 void TurboAssembler::LeaveFrame(StackFrame::Type type) {
-  if (emit_debug_code() && !StackFrame::IsJavaScript(type)) {
+  if (FLAG_debug_code && !StackFrame::IsJavaScript(type)) {
     cmp(Operand(ebp, CommonFrameConstants::kContextOrFrameTypeOffset),
         Immediate(StackFrame::TypeToMarker(type)));
     Check(equal, AbortReason::kStackFrameTypesMustMatch);
@@ -1389,8 +1376,8 @@ void MacroAssembler::JumpToExternalReference(const ExternalReference& ext,
                                              bool builtin_exit_frame) {
   // Set the entry point and jump to the C entry runtime stub.
   Move(kRuntimeCallFunctionRegister, Immediate(ext));
-  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, kDontSaveFPRegs,
-                                          kArgvOnStack, builtin_exit_frame);
+  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, SaveFPRegsMode::kIgnore,
+                                          ArgvMode::kStack, builtin_exit_frame);
   Jump(code, RelocInfo::CODE_TARGET);
 }
 
@@ -1494,7 +1481,7 @@ void MacroAssembler::StackOverflowCheck(Register num_args, Register scratch,
 
 void MacroAssembler::InvokePrologue(Register expected_parameter_count,
                                     Register actual_parameter_count,
-                                    Label* done, InvokeFlag flag) {
+                                    Label* done, InvokeType type) {
   if (expected_parameter_count != actual_parameter_count) {
     DCHECK_EQ(actual_parameter_count, eax);
     DCHECK_EQ(expected_parameter_count, ecx);
@@ -1531,9 +1518,9 @@ void MacroAssembler::InvokePrologue(Register expected_parameter_count,
           Operand(expected_parameter_count, times_system_pointer_size, 0));
       AllocateStackSpace(scratch);
       // Extra words are the receiver and the return address (if a jump).
-      int extra_words = flag == CALL_FUNCTION ? 1 : 2;
+      int extra_words = type == InvokeType::kCall ? 1 : 2;
       lea(num, Operand(eax, extra_words));  // Number of words to copy.
-      Set(current, 0);
+      Move(current, 0);
       // Fall-through to the loop body because there are non-zero words to copy.
       bind(&copy);
       mov(scratch, Operand(src, current, times_system_pointer_size, 0));
@@ -1610,9 +1597,9 @@ void MacroAssembler::CallDebugOnFunctionCall(Register fun, Register new_target,
 void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
                                         Register expected_parameter_count,
                                         Register actual_parameter_count,
-                                        InvokeFlag flag) {
+                                        InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
   DCHECK_EQ(function, edi);
   DCHECK_IMPLIES(new_target.is_valid(), new_target == edx);
   DCHECK(expected_parameter_count == ecx || expected_parameter_count == eax);
@@ -1636,17 +1623,19 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
   }
 
   Label done;
-  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, flag);
+  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, type);
   // We call indirectly through the code field in the function to
   // allow recompilation to take effect without changing any of the
   // call sites.
   static_assert(kJavaScriptCallCodeStartRegister == ecx, "ABI mismatch");
   mov(ecx, FieldOperand(function, JSFunction::kCodeOffset));
-  if (flag == CALL_FUNCTION) {
-    CallCodeObject(ecx);
-  } else {
-    DCHECK(flag == JUMP_FUNCTION);
-    JumpCodeObject(ecx);
+  switch (type) {
+    case InvokeType::kCall:
+      CallCodeObject(ecx);
+      break;
+    case InvokeType::kJump:
+      JumpCodeObject(ecx);
+      break;
   }
   jmp(&done, Label::kNear);
 
@@ -1661,9 +1650,9 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
 
 void MacroAssembler::InvokeFunction(Register fun, Register new_target,
                                     Register actual_parameter_count,
-                                    InvokeFlag flag) {
+                                    InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK(flag == JUMP_FUNCTION || has_frame());
+  DCHECK(type == InvokeType::kJump || has_frame());
 
   DCHECK(fun == edi);
   mov(ecx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
@@ -1671,7 +1660,7 @@ void MacroAssembler::InvokeFunction(Register fun, Register new_target,
   movzx_w(ecx,
           FieldOperand(ecx, SharedFunctionInfo::kFormalParameterCountOffset));
 
-  InvokeFunctionCode(edi, new_target, ecx, actual_parameter_count, flag);
+  InvokeFunctionCode(edi, new_target, ecx, actual_parameter_count, type);
 }
 
 void MacroAssembler::LoadGlobalProxy(Register dst) {
@@ -1852,34 +1841,6 @@ void TurboAssembler::Pshufb(XMMRegister dst, XMMRegister src, Operand mask) {
   pshufb(dst, mask);
 }
 
-void TurboAssembler::Pblendw(XMMRegister dst, Operand src, uint8_t imm8) {
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    vpblendw(dst, dst, src, imm8);
-    return;
-  }
-  if (CpuFeatures::IsSupported(SSE4_1)) {
-    CpuFeatureScope sse_scope(this, SSE4_1);
-    pblendw(dst, src, imm8);
-    return;
-  }
-  FATAL("no AVX or SSE4.1 support");
-}
-
-void TurboAssembler::Palignr(XMMRegister dst, Operand src, uint8_t imm8) {
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    vpalignr(dst, dst, src, imm8);
-    return;
-  }
-  if (CpuFeatures::IsSupported(SSSE3)) {
-    CpuFeatureScope sse_scope(this, SSSE3);
-    palignr(dst, src, imm8);
-    return;
-  }
-  FATAL("no AVX or SSE3 support");
-}
-
 void TurboAssembler::Pextrd(Register dst, XMMRegister src, uint8_t imm8) {
   if (imm8 == 0) {
     Movd(dst, src);
@@ -1994,19 +1955,6 @@ void TurboAssembler::Vbroadcastss(XMMRegister dst, Operand src) {
   shufps(dst, dst, static_cast<byte>(0));
 }
 
-void TurboAssembler::Shufps(XMMRegister dst, XMMRegister src1, XMMRegister src2,
-                            uint8_t imm8) {
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope avx_scope(this, AVX);
-    vshufps(dst, src1, src2, imm8);
-  } else {
-    if (dst != src1) {
-      movaps(dst, src1);
-    }
-    shufps(dst, src2, imm8);
-  }
-}
-
 void TurboAssembler::Lzcnt(Register dst, Operand src) {
   if (CpuFeatures::IsSupported(LZCNT)) {
     CpuFeatureScope scope(this, LZCNT);
@@ -2079,11 +2027,11 @@ void MacroAssembler::DecrementCounter(StatsCounter* counter, int value,
 }
 
 void TurboAssembler::Assert(Condition cc, AbortReason reason) {
-  if (emit_debug_code()) Check(cc, reason);
+  if (FLAG_debug_code) Check(cc, reason);
 }
 
 void TurboAssembler::AssertUnreachable(AbortReason reason) {
-  if (emit_debug_code()) Abort(reason);
+  if (FLAG_debug_code) Abort(reason);
 }
 
 void TurboAssembler::Check(Condition cc, AbortReason reason) {
@@ -2109,11 +2057,11 @@ void TurboAssembler::CheckStackAlignment() {
 }
 
 void TurboAssembler::Abort(AbortReason reason) {
-#ifdef DEBUG
-  const char* msg = GetAbortReason(reason);
-  RecordComment("Abort message: ");
-  RecordComment(msg);
-#endif
+  if (FLAG_code_comments) {
+    const char* msg = GetAbortReason(reason);
+    RecordComment("Abort message: ");
+    RecordComment(msg);
+  }
 
   // Avoid emitting call to builtin if requested.
   if (trap_on_abort()) {
@@ -2171,7 +2119,7 @@ void TurboAssembler::CallCFunction(Register function, int num_arguments) {
   DCHECK_LE(num_arguments, kMaxCParameters);
   DCHECK(has_frame());
   // Check stack alignment.
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     CheckStackAlignment();
   }
 
diff --git a/chromium/v8/src/codegen/ia32/macro-assembler-ia32.h b/chromium/v8/src/codegen/ia32/macro-assembler-ia32.h
index 4c5c3ade021..a21a3555682 100644
--- a/chromium/v8/src/codegen/ia32/macro-assembler-ia32.h
+++ b/chromium/v8/src/codegen/ia32/macro-assembler-ia32.h
@@ -44,9 +44,6 @@ class StatsCounter;
 // distinguish memory operands from other operands on ia32.
 using MemOperand = Operand;
 
-enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
-enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
-
 // TODO(victorgomes): Move definition to macro-assembler.h, once all other
 // platforms are updated.
 enum class StackLimitKind { kInterruptStackLimit, kRealStackLimit };
@@ -122,6 +119,13 @@ class V8_EXPORT_PRIVATE TurboAssembler : public SharedTurboAssembler {
   void CheckStackAlignment();
 
   // Move a constant into a destination using the most efficient encoding.
+  void Move(Register dst, int32_t x) {
+    if (x == 0) {
+      xor_(dst, dst);
+    } else {
+      mov(dst, Immediate(x));
+    }
+  }
   void Move(Register dst, const Immediate& src);
   void Move(Register dst, Smi src) { Move(dst, Immediate(src)); }
   void Move(Register dst, Handle<HeapObject> src);
@@ -301,152 +305,11 @@ class V8_EXPORT_PRIVATE TurboAssembler : public SharedTurboAssembler {
   // may be bigger than 2^16 - 1.  Requires a scratch register.
   void Ret(int bytes_dropped, Register scratch);
 
-// Only use these macros when non-destructive source of AVX version is not
-// needed.
-#define AVX_OP3_WITH_TYPE(macro_name, name, dst_type, src_type) \
-  void macro_name(dst_type dst, src_type src) {                 \
-    if (CpuFeatures::IsSupported(AVX)) {                        \
-      CpuFeatureScope scope(this, AVX);                         \
-      v##name(dst, dst, src);                                   \
-    } else {                                                    \
-      name(dst, src);                                           \
-    }                                                           \
-  }
-#define AVX_OP3_XO(macro_name, name)                            \
-  AVX_OP3_WITH_TYPE(macro_name, name, XMMRegister, XMMRegister) \
-  AVX_OP3_WITH_TYPE(macro_name, name, XMMRegister, Operand)
-
-  AVX_OP3_XO(Packsswb, packsswb)
-  AVX_OP3_XO(Packuswb, packuswb)
-  AVX_OP3_XO(Paddusb, paddusb)
-  AVX_OP3_XO(Pand, pand)
-  AVX_OP3_XO(Pcmpeqb, pcmpeqb)
-  AVX_OP3_XO(Pcmpeqw, pcmpeqw)
-  AVX_OP3_XO(Pcmpeqd, pcmpeqd)
-  AVX_OP3_XO(Por, por)
-  AVX_OP3_XO(Psubb, psubb)
-  AVX_OP3_XO(Psubw, psubw)
-  AVX_OP3_XO(Psubd, psubd)
-  AVX_OP3_XO(Psubq, psubq)
-  AVX_OP3_XO(Punpcklbw, punpcklbw)
-  AVX_OP3_XO(Punpckhbw, punpckhbw)
-  AVX_OP3_XO(Punpckldq, punpckldq)
-  AVX_OP3_XO(Punpcklqdq, punpcklqdq)
-  AVX_OP3_XO(Pxor, pxor)
-  AVX_OP3_XO(Andps, andps)
-  AVX_OP3_XO(Andpd, andpd)
-  AVX_OP3_XO(Xorps, xorps)
-  AVX_OP3_XO(Xorpd, xorpd)
-  AVX_OP3_XO(Sqrtss, sqrtss)
-  AVX_OP3_XO(Sqrtsd, sqrtsd)
-  AVX_OP3_XO(Orps, orps)
-  AVX_OP3_XO(Orpd, orpd)
-  AVX_OP3_XO(Andnpd, andnpd)
-  AVX_OP3_WITH_TYPE(Movhlps, movhlps, XMMRegister, XMMRegister)
-  AVX_OP3_WITH_TYPE(Psraw, psraw, XMMRegister, uint8_t)
-  AVX_OP3_WITH_TYPE(Psrlq, psrlq, XMMRegister, uint8_t)
-
-#undef AVX_OP3_XO
-#undef AVX_OP3_WITH_TYPE
-
-// Same as AVX_OP3_WITH_TYPE but supports a CpuFeatureScope
-#define AVX_OP2_WITH_TYPE_SCOPE(macro_name, name, dst_type, src_type, \
-                                sse_scope)                            \
-  void macro_name(dst_type dst, src_type src) {                       \
-    if (CpuFeatures::IsSupported(AVX)) {                              \
-      CpuFeatureScope scope(this, AVX);                               \
-      v##name(dst, dst, src);                                         \
-    } else if (CpuFeatures::IsSupported(sse_scope)) {                 \
-      CpuFeatureScope scope(this, sse_scope);                         \
-      name(dst, src);                                                 \
-    }                                                                 \
-  }
-#define AVX_OP2_XO(macro_name, name, sse_scope)                       \
-  AVX_OP2_WITH_TYPE_SCOPE(macro_name, name, XMMRegister, XMMRegister, \
-                          sse_scope)                                  \
-  AVX_OP2_WITH_TYPE_SCOPE(macro_name, name, XMMRegister, Operand, sse_scope)
-  AVX_OP2_XO(Psignb, psignb, SSSE3)
-  AVX_OP2_XO(Psignw, psignw, SSSE3)
-  AVX_OP2_XO(Psignd, psignd, SSSE3)
-  AVX_OP2_XO(Pcmpeqq, pcmpeqq, SSE4_1)
-#undef AVX_OP2_XO
-#undef AVX_OP2_WITH_TYPE_SCOPE
-
-// Only use this macro when dst and src1 is the same in SSE case.
-#define AVX_PACKED_OP3_WITH_TYPE(macro_name, name, dst_type, src_type) \
-  void macro_name(dst_type dst, dst_type src1, src_type src2) {        \
-    if (CpuFeatures::IsSupported(AVX)) {                               \
-      CpuFeatureScope scope(this, AVX);                                \
-      v##name(dst, src1, src2);                                        \
-    } else {                                                           \
-      DCHECK_EQ(dst, src1);                                            \
-      name(dst, src2);                                                 \
-    }                                                                  \
-  }
-#define AVX_PACKED_OP3(macro_name, name)                               \
-  AVX_PACKED_OP3_WITH_TYPE(macro_name, name, XMMRegister, XMMRegister) \
-  AVX_PACKED_OP3_WITH_TYPE(macro_name, name, XMMRegister, Operand)
-
-  AVX_PACKED_OP3(Unpcklps, unpcklps)
-  AVX_PACKED_OP3(Andnps, andnps)
-  AVX_PACKED_OP3(Addps, addps)
-  AVX_PACKED_OP3(Addpd, addpd)
-  AVX_PACKED_OP3(Subps, subps)
-  AVX_PACKED_OP3(Subpd, subpd)
-  AVX_PACKED_OP3(Mulps, mulps)
-  AVX_PACKED_OP3(Mulpd, mulpd)
-  AVX_PACKED_OP3(Divps, divps)
-  AVX_PACKED_OP3(Divpd, divpd)
-  AVX_PACKED_OP3(Cmpeqpd, cmpeqpd)
-  AVX_PACKED_OP3(Cmpneqpd, cmpneqpd)
-  AVX_PACKED_OP3(Cmpltpd, cmpltpd)
-  AVX_PACKED_OP3(Cmpleps, cmpleps)
-  AVX_PACKED_OP3(Cmplepd, cmplepd)
-  AVX_PACKED_OP3(Minps, minps)
-  AVX_PACKED_OP3(Minpd, minpd)
-  AVX_PACKED_OP3(Maxps, maxps)
-  AVX_PACKED_OP3(Maxpd, maxpd)
-  AVX_PACKED_OP3(Cmpunordps, cmpunordps)
-  AVX_PACKED_OP3(Cmpunordpd, cmpunordpd)
-  AVX_PACKED_OP3(Psllw, psllw)
-  AVX_PACKED_OP3(Pslld, pslld)
-  AVX_PACKED_OP3(Psllq, psllq)
-  AVX_PACKED_OP3(Psrlw, psrlw)
-  AVX_PACKED_OP3(Psrld, psrld)
-  AVX_PACKED_OP3(Psrlq, psrlq)
-  AVX_PACKED_OP3(Psraw, psraw)
-  AVX_PACKED_OP3(Psrad, psrad)
-  AVX_PACKED_OP3(Paddd, paddd)
-  AVX_PACKED_OP3(Paddq, paddq)
-  AVX_PACKED_OP3(Psubd, psubd)
-  AVX_PACKED_OP3(Psubq, psubq)
-  AVX_PACKED_OP3(Pmuludq, pmuludq)
-  AVX_PACKED_OP3(Pavgb, pavgb)
-  AVX_PACKED_OP3(Pavgw, pavgw)
-  AVX_PACKED_OP3(Pand, pand)
-  AVX_PACKED_OP3(Pminub, pminub)
-  AVX_PACKED_OP3(Pmaxub, pmaxub)
-  AVX_PACKED_OP3(Paddusb, paddusb)
-  AVX_PACKED_OP3(Psubusb, psubusb)
-  AVX_PACKED_OP3(Pcmpgtb, pcmpgtb)
-  AVX_PACKED_OP3(Pcmpeqb, pcmpeqb)
-  AVX_PACKED_OP3(Paddb, paddb)
-  AVX_PACKED_OP3(Paddsb, paddsb)
-  AVX_PACKED_OP3(Psubb, psubb)
-  AVX_PACKED_OP3(Psubsb, psubsb)
-
-#undef AVX_PACKED_OP3
-
-  AVX_PACKED_OP3_WITH_TYPE(Psllw, psllw, XMMRegister, uint8_t)
-  AVX_PACKED_OP3_WITH_TYPE(Pslld, pslld, XMMRegister, uint8_t)
-  AVX_PACKED_OP3_WITH_TYPE(Psllq, psllq, XMMRegister, uint8_t)
-  AVX_PACKED_OP3_WITH_TYPE(Psrlw, psrlw, XMMRegister, uint8_t)
-  AVX_PACKED_OP3_WITH_TYPE(Psrld, psrld, XMMRegister, uint8_t)
-  AVX_PACKED_OP3_WITH_TYPE(Psrlq, psrlq, XMMRegister, uint8_t)
-  AVX_PACKED_OP3_WITH_TYPE(Psraw, psraw, XMMRegister, uint8_t)
-  AVX_PACKED_OP3_WITH_TYPE(Psrad, psrad, XMMRegister, uint8_t)
-
-#undef AVX_PACKED_OP3_WITH_TYPE
+  // Defined here because some callers take a pointer to member functions.
+  AVX_OP(Pcmpeqb, pcmpeqb)
+  AVX_OP(Pcmpeqw, pcmpeqw)
+  AVX_OP(Pcmpeqd, pcmpeqd)
+  AVX_OP_SSE4_1(Pcmpeqq, pcmpeqq)
 
 // Macro for instructions that have 2 operands for AVX version and 1 operand for
 // SSE version. Will move src1 to dst if dst != src1.
@@ -468,35 +331,6 @@ class V8_EXPORT_PRIVATE TurboAssembler : public SharedTurboAssembler {
   AVX_OP3_WITH_MOVE(Pmaddwd, pmaddwd, XMMRegister, Operand)
 #undef AVX_OP3_WITH_MOVE
 
-#define AVX_OP3_WITH_TYPE_SCOPE(macro_name, name, dst_type, src_type, \
-                                sse_scope)                            \
-  void macro_name(dst_type dst, dst_type src1, src_type src2) {       \
-    if (CpuFeatures::IsSupported(AVX)) {                              \
-      CpuFeatureScope scope(this, AVX);                               \
-      v##name(dst, src1, src2);                                       \
-      return;                                                         \
-    }                                                                 \
-    if (CpuFeatures::IsSupported(sse_scope)) {                        \
-      CpuFeatureScope scope(this, sse_scope);                         \
-      DCHECK_EQ(dst, src1);                                           \
-      name(dst, src2);                                                \
-      return;                                                         \
-    }                                                                 \
-    UNREACHABLE();                                                    \
-  }
-#define AVX_OP3_XO_SSE4(macro_name, name)                                     \
-  AVX_OP3_WITH_TYPE_SCOPE(macro_name, name, XMMRegister, XMMRegister, SSE4_1) \
-  AVX_OP3_WITH_TYPE_SCOPE(macro_name, name, XMMRegister, Operand, SSE4_1)
-
-  AVX_OP3_WITH_TYPE_SCOPE(Haddps, haddps, XMMRegister, Operand, SSE3)
-  AVX_OP3_XO_SSE4(Pmaxsd, pmaxsd)
-  AVX_OP3_XO_SSE4(Pminsb, pminsb)
-  AVX_OP3_XO_SSE4(Pmaxsb, pmaxsb)
-  AVX_OP3_XO_SSE4(Pcmpeqq, pcmpeqq)
-
-#undef AVX_OP3_XO_SSE4
-#undef AVX_OP3_WITH_TYPE_SCOPE
-
   // TODO(zhin): Remove after moving more definitions into SharedTurboAssembler.
   void Movlps(Operand dst, XMMRegister src) {
     SharedTurboAssembler::Movlps(dst, src);
@@ -513,16 +347,6 @@ class V8_EXPORT_PRIVATE TurboAssembler : public SharedTurboAssembler {
   }
   void Pshufb(XMMRegister dst, XMMRegister src, Operand mask);
 
-  void Pblendw(XMMRegister dst, XMMRegister src, uint8_t imm8) {
-    Pblendw(dst, Operand(src), imm8);
-  }
-  void Pblendw(XMMRegister dst, Operand src, uint8_t imm8);
-
-  void Palignr(XMMRegister dst, XMMRegister src, uint8_t imm8) {
-    Palignr(dst, Operand(src), imm8);
-  }
-  void Palignr(XMMRegister dst, Operand src, uint8_t imm8);
-
   void Pextrd(Register dst, XMMRegister src, uint8_t imm8);
   void Pinsrb(XMMRegister dst, Register src, int8_t imm8) {
     Pinsrb(dst, Operand(src), imm8);
@@ -544,10 +368,6 @@ class V8_EXPORT_PRIVATE TurboAssembler : public SharedTurboAssembler {
   void Pinsrw(XMMRegister dst, XMMRegister src1, Operand src2, int8_t imm8);
   void Vbroadcastss(XMMRegister dst, Operand src);
 
-  // Shufps that will mov src1 into dst if AVX is not supported.
-  void Shufps(XMMRegister dst, XMMRegister src1, XMMRegister src2,
-              uint8_t imm8);
-
   // Expression support
   // cvtsi2sd instruction only writes to the low 64-bit of dst register, which
   // hinders register renaming and makes dependence chains longer. So we use
@@ -680,15 +500,6 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
  public:
   using TurboAssembler::TurboAssembler;
 
-  // Load a register with a long value as efficiently as possible.
-  void Set(Register dst, int32_t x) {
-    if (x == 0) {
-      xor_(dst, dst);
-    } else {
-      mov(dst, Immediate(x));
-    }
-  }
-
   void PushRoot(RootIndex index);
 
   // Compare the object in a register to a value and jump if they are equal.
@@ -722,8 +533,8 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   void RecordWriteField(
       Register object, int offset, Register value, Register scratch,
       SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
   // For page containing |object| mark region covering |address|
   // dirty. |object| is the object being stored into, |value| is the
@@ -732,11 +543,8 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // write barrier if the value is a smi.
   void RecordWrite(
       Register object, Register address, Register value, SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
-
-  // Frame restart support
-  void MaybeDropFrames();
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
   // Enter specific kind of exit frame. Expects the number of
   // arguments in register eax and sets up the number of arguments in
@@ -768,7 +576,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
 
   void InvokeFunctionCode(Register function, Register new_target,
                           Register expected_parameter_count,
-                          Register actual_parameter_count, InvokeFlag flag);
+                          Register actual_parameter_count, InvokeType type);
 
   // On function call, call into the debugger.
   // This may clobber ecx.
@@ -779,7 +587,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // Invoke the JavaScript function in the given register. Changes the
   // current context to the context in the function before invoking.
   void InvokeFunction(Register function, Register new_target,
-                      Register actual_parameter_count, InvokeFlag flag);
+                      Register actual_parameter_count, InvokeType type);
 
   // Compare object type for heap object.
   // Incoming register is heap_object and outgoing register is map.
@@ -865,18 +673,18 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
 
   // Call a runtime routine.
   void CallRuntime(const Runtime::Function* f, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs);
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore);
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId fid,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     const Runtime::Function* function = Runtime::FunctionForId(fid);
     CallRuntime(function, function->nargs, save_doubles);
   }
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId fid, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     CallRuntime(Runtime::FunctionForId(fid), num_arguments, save_doubles);
   }
 
@@ -921,7 +729,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // Helper functions for generating invokes.
   void InvokePrologue(Register expected_parameter_count,
                       Register actual_parameter_count, Label* done,
-                      InvokeFlag flag);
+                      InvokeType type);
 
   void EnterExitFramePrologue(StackFrame::Type frame_type, Register scratch);
   void EnterExitFrameEpilogue(int argc, bool save_doubles);
diff --git a/chromium/v8/src/codegen/interface-descriptors-inl.h b/chromium/v8/src/codegen/interface-descriptors-inl.h
new file mode 100644
index 00000000000..273e9d3e8e0
--- /dev/null
+++ b/chromium/v8/src/codegen/interface-descriptors-inl.h
@@ -0,0 +1,484 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_CODEGEN_INTERFACE_DESCRIPTORS_INL_H_
+#define V8_CODEGEN_INTERFACE_DESCRIPTORS_INL_H_
+
+#include <utility>
+
+#include "src/base/logging.h"
+#include "src/codegen/interface-descriptors.h"
+#include "src/codegen/register-arch.h"
+
+#if V8_TARGET_ARCH_X64
+#include "src/codegen/x64/interface-descriptors-x64-inl.h"
+#elif V8_TARGET_ARCH_ARM64
+#include "src/codegen/arm64/interface-descriptors-arm64-inl.h"
+#elif V8_TARGET_ARCH_IA32
+#include "src/codegen/ia32/interface-descriptors-ia32-inl.h"
+#elif V8_TARGET_ARCH_ARM
+#include "src/codegen/arm/interface-descriptors-arm-inl.h"
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
+#include "src/codegen/ppc/interface-descriptors-ppc-inl.h"
+#elif V8_TARGET_ARCH_S390
+#include "src/codegen/s390/interface-descriptors-s390-inl.h"
+#elif V8_TARGET_ARCH_MIPS64
+#include "src/codegen/mips64/interface-descriptors-mips64-inl.h"
+#elif V8_TARGET_ARCH_MIPS
+#include "src/codegen/mips/interface-descriptors-mips-inl.h"
+#elif V8_TARGET_ARCH_RISCV64
+#include "src/codegen/riscv64/interface-descriptors-riscv64-inl.h"
+#else
+#error Unsupported target architecture.
+#endif
+
+namespace v8 {
+namespace internal {
+
+// static
+constexpr std::array<Register, kJSBuiltinRegisterParams>
+CallInterfaceDescriptor::DefaultJSRegisterArray() {
+  return RegisterArray(
+      kJavaScriptCallTargetRegister, kJavaScriptCallNewTargetRegister,
+      kJavaScriptCallArgCountRegister, kJavaScriptCallExtraArg1Register);
+}
+
+// static
+template <typename DerivedDescriptor>
+constexpr auto StaticCallInterfaceDescriptor<DerivedDescriptor>::registers() {
+  return CallInterfaceDescriptor::DefaultRegisterArray();
+}
+
+// static
+template <typename DerivedDescriptor>
+constexpr auto StaticJSCallInterfaceDescriptor<DerivedDescriptor>::registers() {
+  return CallInterfaceDescriptor::DefaultJSRegisterArray();
+}
+
+template <typename DerivedDescriptor>
+void StaticCallInterfaceDescriptor<DerivedDescriptor>::Initialize(
+    CallInterfaceDescriptorData* data) {
+  // Static local copy of the Registers array, for platform-specific
+  // initialization
+  static auto registers = DerivedDescriptor::registers();
+
+  // The passed pointer should be a modifiable pointer to our own data.
+  DCHECK_EQ(data, this->data());
+  DCHECK(!data->IsInitialized());
+
+  if (DerivedDescriptor::kRestrictAllocatableRegisters) {
+    data->RestrictAllocatableRegisters(registers.data(), registers.size());
+  }
+
+  data->InitializeRegisters(
+      DerivedDescriptor::flags(), DerivedDescriptor::kReturnCount,
+      DerivedDescriptor::GetParameterCount(),
+      DerivedDescriptor::kStackArgumentOrder,
+      DerivedDescriptor::GetRegisterParameterCount(), registers.data());
+
+  // InitializeTypes is customizable by the DerivedDescriptor subclass.
+  DerivedDescriptor::InitializeTypes(data);
+
+  DCHECK(data->IsInitialized());
+  DCHECK(this->CheckFloatingPointParameters(data));
+}
+
+// static
+template <typename DerivedDescriptor>
+constexpr int
+StaticCallInterfaceDescriptor<DerivedDescriptor>::GetReturnCount() {
+  static_assert(
+      DerivedDescriptor::kReturnCount >= 0,
+      "DerivedDescriptor subclass should override return count with a value "
+      "that is greater than 0");
+
+  return DerivedDescriptor::kReturnCount;
+}
+
+// static
+template <typename DerivedDescriptor>
+constexpr int
+StaticCallInterfaceDescriptor<DerivedDescriptor>::GetParameterCount() {
+  static_assert(
+      DerivedDescriptor::kParameterCount >= 0,
+      "DerivedDescriptor subclass should override parameter count with a "
+      "value that is greater than 0");
+
+  return DerivedDescriptor::kParameterCount;
+}
+
+namespace detail {
+
+// Helper trait for statically checking if a type is a std::array<Register,N>.
+template <typename T>
+struct IsRegisterArray : public std::false_type {};
+template <size_t N>
+struct IsRegisterArray<std::array<Register, N>> : public std::true_type {};
+template <>
+struct IsRegisterArray<EmptyRegisterArray> : public std::true_type {};
+
+// Helper for finding the index of the first invalid register in a register
+// array.
+template <size_t N, size_t Index>
+struct FirstInvalidRegisterHelper {
+  static constexpr int Call(std::array<Register, N> regs) {
+    if (!std::get<Index>(regs).is_valid()) {
+      // All registers after the first invalid one have to also be invalid (this
+      // DCHECK will be checked recursively).
+      DCHECK_EQ((FirstInvalidRegisterHelper<N, Index + 1>::Call(regs)),
+                Index + 1);
+      return Index;
+    }
+    return FirstInvalidRegisterHelper<N, Index + 1>::Call(regs);
+  }
+};
+template <size_t N>
+struct FirstInvalidRegisterHelper<N, N> {
+  static constexpr int Call(std::array<Register, N> regs) { return N; }
+};
+template <size_t N, size_t Index = 0>
+constexpr size_t FirstInvalidRegister(std::array<Register, N> regs) {
+  return FirstInvalidRegisterHelper<N, 0>::Call(regs);
+}
+constexpr size_t FirstInvalidRegister(EmptyRegisterArray regs) { return 0; }
+
+}  // namespace detail
+
+// static
+template <typename DerivedDescriptor>
+constexpr int
+StaticCallInterfaceDescriptor<DerivedDescriptor>::GetRegisterParameterCount() {
+  static_assert(
+      detail::IsRegisterArray<decltype(DerivedDescriptor::registers())>::value,
+      "DerivedDescriptor subclass should define a registers() function "
+      "returning a std::array<Register>");
+
+  // The register parameter count is the minimum of:
+  //   1. The number of named parameters in the descriptor, and
+  //   2. The number of valid registers the descriptor provides with its
+  //      registers() function, e.g. for {rax, rbx, no_reg} this number is 2.
+  //   3. The maximum number of register parameters allowed (
+  //      kMaxBuiltinRegisterParams for most builtins,
+  //      kMaxTFSBuiltinRegisterParams for TFS builtins, customizable by the
+  //      subclass otherwise).
+  return std::min<int>({DerivedDescriptor::GetParameterCount(),
+                        static_cast<int>(detail::FirstInvalidRegister(
+                            DerivedDescriptor::registers())),
+                        DerivedDescriptor::kMaxRegisterParams});
+}
+
+// static
+template <typename DerivedDescriptor>
+constexpr int
+StaticCallInterfaceDescriptor<DerivedDescriptor>::GetStackParameterCount() {
+  return DerivedDescriptor::GetParameterCount() -
+         DerivedDescriptor::GetRegisterParameterCount();
+}
+
+// static
+constexpr Register FastNewObjectDescriptor::TargetRegister() {
+  return kJSFunctionRegister;
+}
+
+// static
+constexpr Register FastNewObjectDescriptor::NewTargetRegister() {
+  return kJavaScriptCallNewTargetRegister;
+}
+
+// static
+constexpr Register ApiGetterDescriptor::ReceiverRegister() {
+  return LoadDescriptor::ReceiverRegister();
+}
+
+// static
+constexpr Register LoadGlobalNoFeedbackDescriptor::ICKindRegister() {
+  return LoadDescriptor::SlotRegister();
+}
+
+// static
+constexpr Register LoadNoFeedbackDescriptor::ICKindRegister() {
+  return LoadGlobalNoFeedbackDescriptor::ICKindRegister();
+}
+
+#if V8_TARGET_ARCH_IA32
+// On ia32, LoadWithVectorDescriptor passes vector on the stack and thus we
+// need to choose a new register here.
+// static
+constexpr Register LoadGlobalWithVectorDescriptor::VectorRegister() {
+  STATIC_ASSERT(!LoadWithVectorDescriptor::VectorRegister().is_valid());
+  return LoadDescriptor::ReceiverRegister();
+}
+#else
+// static
+constexpr Register LoadGlobalWithVectorDescriptor::VectorRegister() {
+  return LoadWithVectorDescriptor::VectorRegister();
+}
+#endif
+
+// static
+constexpr auto LoadDescriptor::registers() {
+  return RegisterArray(ReceiverRegister(), NameRegister(), SlotRegister());
+}
+
+// static
+constexpr auto LoadBaselineDescriptor::registers() {
+  return LoadDescriptor::registers();
+}
+
+// static
+constexpr auto LoadGlobalDescriptor::registers() {
+  return RegisterArray(LoadDescriptor::NameRegister(),
+                       LoadDescriptor::SlotRegister());
+}
+
+// static
+constexpr auto LoadGlobalBaselineDescriptor::registers() {
+  return LoadGlobalDescriptor::registers();
+}
+
+// static
+constexpr auto StoreDescriptor::registers() {
+  return RegisterArray(ReceiverRegister(), NameRegister(), ValueRegister(),
+                       SlotRegister());
+}
+
+// static
+constexpr auto StoreBaselineDescriptor::registers() {
+  return StoreDescriptor::registers();
+}
+
+// static
+constexpr auto StoreGlobalDescriptor::registers() {
+  return RegisterArray(StoreDescriptor::NameRegister(),
+                       StoreDescriptor::ValueRegister(),
+                       StoreDescriptor::SlotRegister());
+}
+
+// static
+constexpr auto StoreGlobalBaselineDescriptor::registers() {
+  return StoreGlobalDescriptor::registers();
+}
+
+// static
+constexpr auto LoadWithReceiverBaselineDescriptor::registers() {
+  return RegisterArray(
+      LoadDescriptor::ReceiverRegister(),
+      LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister(),
+      LoadDescriptor::NameRegister(), LoadDescriptor::SlotRegister());
+}
+
+// static
+constexpr auto BaselineOutOfLinePrologueDescriptor::registers() {
+  // TODO(v8:11421): Implement on other platforms.
+#if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_IA32 || \
+    V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64 ||  \
+    V8_TARGET_ARCH_S390 || V8_TARGET_ARCH_RISCV64
+  return RegisterArray(
+      kContextRegister, kJSFunctionRegister, kJavaScriptCallArgCountRegister,
+      kJavaScriptCallExtraArg1Register, kJavaScriptCallNewTargetRegister,
+      kInterpreterBytecodeArrayRegister);
+#else
+  return DefaultRegisterArray();
+#endif
+}
+
+// static
+constexpr auto BaselineLeaveFrameDescriptor::registers() {
+  // TODO(v8:11421): Implement on other platforms.
+#if V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || \
+    V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64 ||  \
+    V8_TARGET_ARCH_S390 || V8_TARGET_ARCH_RISCV64
+  return RegisterArray(ParamsSizeRegister(), WeightRegister());
+#else
+  return DefaultRegisterArray();
+#endif
+}
+
+// static
+constexpr auto VoidDescriptor::registers() { return RegisterArray(); }
+
+// static
+constexpr auto AllocateDescriptor::registers() {
+  return RegisterArray(kAllocateSizeRegister);
+}
+
+// static
+constexpr auto CEntry1ArgvOnStackDescriptor::registers() {
+  return RegisterArray(kRuntimeCallArgCountRegister,
+                       kRuntimeCallFunctionRegister);
+}
+
+// static
+constexpr auto InterpreterCEntry1Descriptor::registers() {
+  return RegisterArray(kRuntimeCallArgCountRegister, kRuntimeCallArgvRegister,
+                       kRuntimeCallFunctionRegister);
+}
+
+// static
+constexpr auto InterpreterCEntry2Descriptor::registers() {
+  return RegisterArray(kRuntimeCallArgCountRegister, kRuntimeCallArgvRegister,
+                       kRuntimeCallFunctionRegister);
+}
+
+// static
+constexpr auto FastNewObjectDescriptor::registers() {
+  return RegisterArray(TargetRegister(), NewTargetRegister());
+}
+
+// static
+constexpr auto TailCallOptimizedCodeSlotDescriptor::registers() {
+  return RegisterArray(kJavaScriptCallCodeStartRegister);
+}
+
+// static
+constexpr auto LoadNoFeedbackDescriptor::registers() {
+  return RegisterArray(LoadDescriptor::ReceiverRegister(),
+                       LoadDescriptor::NameRegister(), ICKindRegister());
+}
+
+// static
+constexpr auto LoadGlobalNoFeedbackDescriptor::registers() {
+  return RegisterArray(LoadDescriptor::NameRegister(), ICKindRegister());
+}
+
+// static
+constexpr auto LoadGlobalWithVectorDescriptor::registers() {
+  return RegisterArray(LoadDescriptor::NameRegister(),
+                       LoadDescriptor::SlotRegister(), VectorRegister());
+}
+
+// static
+constexpr auto LoadWithReceiverAndVectorDescriptor::registers() {
+  return RegisterArray(
+      LoadDescriptor::ReceiverRegister(), LookupStartObjectRegister(),
+      LoadDescriptor::NameRegister(), LoadDescriptor::SlotRegister(),
+      LoadWithVectorDescriptor::VectorRegister());
+}
+
+// static
+constexpr auto StoreGlobalWithVectorDescriptor::registers() {
+  return RegisterArray(StoreDescriptor::NameRegister(),
+                       StoreDescriptor::ValueRegister(),
+                       StoreDescriptor::SlotRegister(),
+                       StoreWithVectorDescriptor::VectorRegister());
+}
+
+// static
+constexpr auto StoreTransitionDescriptor::registers() {
+  return RegisterArray(StoreDescriptor::ReceiverRegister(),
+                       StoreDescriptor::NameRegister(), MapRegister(),
+                       StoreDescriptor::ValueRegister(),
+                       StoreDescriptor::SlotRegister(),
+                       StoreWithVectorDescriptor::VectorRegister());
+}
+
+// static
+constexpr auto TypeConversionDescriptor::registers() {
+  return RegisterArray(ArgumentRegister());
+}
+
+// static
+constexpr auto TypeConversionNoContextDescriptor::registers() {
+  return RegisterArray(TypeConversionDescriptor::ArgumentRegister());
+}
+
+// static
+constexpr auto SingleParameterOnStackDescriptor::registers() {
+  return RegisterArray();
+}
+
+// static
+constexpr auto AsyncFunctionStackParameterDescriptor::registers() {
+  return RegisterArray();
+}
+
+// static
+constexpr auto GetIteratorStackParameterDescriptor::registers() {
+  return RegisterArray();
+}
+
+// static
+constexpr auto LoadWithVectorDescriptor::registers() {
+  return RegisterArray(LoadDescriptor::ReceiverRegister(),
+                       LoadDescriptor::NameRegister(),
+                       LoadDescriptor::SlotRegister(), VectorRegister());
+}
+
+// static
+constexpr auto StoreWithVectorDescriptor::registers() {
+  return RegisterArray(StoreDescriptor::ReceiverRegister(),
+                       StoreDescriptor::NameRegister(),
+                       StoreDescriptor::ValueRegister(),
+                       StoreDescriptor::SlotRegister(), VectorRegister());
+}
+
+// static
+constexpr auto ApiGetterDescriptor::registers() {
+  return RegisterArray(ReceiverRegister(), HolderRegister(),
+                       CallbackRegister());
+}
+
+// static
+constexpr auto ContextOnlyDescriptor::registers() { return RegisterArray(); }
+
+// static
+constexpr auto NoContextDescriptor::registers() { return RegisterArray(); }
+
+// static
+constexpr auto GrowArrayElementsDescriptor::registers() {
+  return RegisterArray(ObjectRegister(), KeyRegister());
+}
+
+// static
+constexpr auto ArrayNArgumentsConstructorDescriptor::registers() {
+  // Keep the arguments on the same registers as they were in
+  // ArrayConstructorDescriptor to avoid unnecessary register moves.
+  // kFunction, kAllocationSite, kActualArgumentsCount
+  return RegisterArray(kJavaScriptCallTargetRegister,
+                       kJavaScriptCallExtraArg1Register,
+                       kJavaScriptCallArgCountRegister);
+}
+
+// static
+constexpr auto ArrayNoArgumentConstructorDescriptor::registers() {
+  // This descriptor must use the same set of registers as the
+  // ArrayNArgumentsConstructorDescriptor.
+  return ArrayNArgumentsConstructorDescriptor::registers();
+}
+
+// static
+constexpr auto ArraySingleArgumentConstructorDescriptor::registers() {
+  // This descriptor must use the same set of registers as the
+  // ArrayNArgumentsConstructorDescriptor.
+  return ArrayNArgumentsConstructorDescriptor::registers();
+}
+
+// static
+// static
+constexpr Register RunMicrotasksDescriptor::MicrotaskQueueRegister() {
+  return GetRegisterParameter(0);
+}
+
+#define DEFINE_STATIC_BUILTIN_DESCRIPTOR_GETTER(Name, DescriptorName) \
+  template <>                                                         \
+  struct CallInterfaceDescriptorFor<Builtins::k##Name> {              \
+    using type = DescriptorName##Descriptor;                          \
+  };
+BUILTIN_LIST(IGNORE_BUILTIN, IGNORE_BUILTIN,
+             /*TFC*/ DEFINE_STATIC_BUILTIN_DESCRIPTOR_GETTER, IGNORE_BUILTIN,
+             /*TFH*/ DEFINE_STATIC_BUILTIN_DESCRIPTOR_GETTER, IGNORE_BUILTIN,
+             /*ASM*/ DEFINE_STATIC_BUILTIN_DESCRIPTOR_GETTER)
+#undef DEFINE_STATIC_BUILTIN_DESCRIPTOR_GETTER
+#define DEFINE_STATIC_BUILTIN_DESCRIPTOR_GETTER(Name, ...) \
+  template <>                                              \
+  struct CallInterfaceDescriptorFor<Builtins::k##Name> {   \
+    using type = Name##Descriptor;                         \
+  };
+BUILTIN_LIST_TFS(DEFINE_STATIC_BUILTIN_DESCRIPTOR_GETTER)
+#undef DEFINE_STATIC_BUILTIN_DESCRIPTOR_GETTER
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_CODEGEN_INTERFACE_DESCRIPTORS_INL_H_
diff --git a/chromium/v8/src/codegen/interface-descriptors.cc b/chromium/v8/src/codegen/interface-descriptors.cc
index 53b678580e4..2cafcae3442 100644
--- a/chromium/v8/src/codegen/interface-descriptors.cc
+++ b/chromium/v8/src/codegen/interface-descriptors.cc
@@ -4,49 +4,48 @@
 
 #include "src/codegen/interface-descriptors.h"
 
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/macro-assembler.h"
 
 namespace v8 {
 namespace internal {
 
-void CallInterfaceDescriptorData::InitializePlatformSpecific(
-    int register_parameter_count, const Register* registers) {
-  DCHECK(!IsInitializedPlatformIndependent());
-
-  register_param_count_ = register_parameter_count;
-
-  // UBSan doesn't like creating zero-length arrays.
-  if (register_parameter_count == 0) return;
+void CallInterfaceDescriptorData::InitializeRegisters(
+    Flags flags, int return_count, int parameter_count,
+    StackArgumentOrder stack_order, int register_parameter_count,
+    const Register* registers) {
+  DCHECK(!IsInitializedTypes());
 
-  // InterfaceDescriptor owns a copy of the registers array.
-  register_params_ = NewArray<Register>(register_parameter_count, no_reg);
-  for (int i = 0; i < register_parameter_count; i++) {
-    // The value of the root register must be reserved, thus any uses
-    // within the calling convention are disallowed.
 #ifdef DEBUG
-    CHECK_NE(registers[i], kRootRegister);
+  {
+    // Make sure that the registers are all valid, and don't alias each other.
+    RegList reglist = 0;
+    for (int i = 0; i < register_parameter_count; ++i) {
+      Register reg = registers[i];
+      DCHECK(reg.is_valid());
+      DCHECK_EQ(reglist & reg.bit(), 0);
+      DCHECK_NE(reg, kRootRegister);
 #ifdef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
-    CHECK_NE(registers[i], kPointerCageBaseRegister);
+      DCHECK_NE(reg, kPtrComprCageBaseRegister);
 #endif
-    // Check for duplicated registers.
-    for (int j = i + 1; j < register_parameter_count; j++) {
-      CHECK_NE(registers[i], registers[j]);
+      reglist = CombineRegLists(reglist, reg.bit());
     }
-#endif
-    register_params_[i] = registers[i];
   }
-}
-
-void CallInterfaceDescriptorData::InitializePlatformIndependent(
-    Flags flags, int return_count, int parameter_count,
-    const MachineType* machine_types, int machine_types_length,
-    StackArgumentOrder stack_order) {
-  DCHECK(IsInitializedPlatformSpecific());
+#endif
 
   flags_ = flags;
   stack_order_ = stack_order;
   return_count_ = return_count;
   param_count_ = parameter_count;
+  register_param_count_ = register_parameter_count;
+
+  // The caller owns the the registers array, so we just set the pointer.
+  register_params_ = registers;
+}
+
+void CallInterfaceDescriptorData::InitializeTypes(
+    const MachineType* machine_types, int machine_types_length) {
+  DCHECK(IsInitializedRegisters());
   const int types_length = return_count_ + param_count_;
 
   // Machine types are either fully initialized or null.
@@ -77,7 +76,6 @@ bool CallInterfaceDescriptorData::AllStackParametersAreTagged() const {
 void CallInterfaceDescriptorData::Reset() {
   delete[] machine_types_;
   machine_types_ = nullptr;
-  delete[] register_params_;
   register_params_ = nullptr;
 }
 
@@ -105,27 +103,6 @@ void CallDescriptors::TearDown() {
   }
 }
 
-void CallInterfaceDescriptor::JSDefaultInitializePlatformSpecific(
-    CallInterfaceDescriptorData* data, int non_js_register_parameter_count) {
-  DCHECK_LE(static_cast<unsigned>(non_js_register_parameter_count), 1);
-
-  // 3 is for kTarget, kNewTarget and kActualArgumentsCount
-  int register_parameter_count = 3 + non_js_register_parameter_count;
-
-  DCHECK(!AreAliased(
-      kJavaScriptCallTargetRegister, kJavaScriptCallNewTargetRegister,
-      kJavaScriptCallArgCountRegister, kJavaScriptCallExtraArg1Register));
-
-  const Register default_js_stub_registers[] = {
-      kJavaScriptCallTargetRegister, kJavaScriptCallNewTargetRegister,
-      kJavaScriptCallArgCountRegister, kJavaScriptCallExtraArg1Register};
-
-  CHECK_LE(static_cast<size_t>(register_parameter_count),
-           arraysize(default_js_stub_registers));
-  data->InitializePlatformSpecific(register_parameter_count,
-                                   default_js_stub_registers);
-}
-
 const char* CallInterfaceDescriptor::DebugName() const {
   CallDescriptors::Key key = CallDescriptors::GetKey(data_);
   switch (key) {
@@ -140,492 +117,12 @@ const char* CallInterfaceDescriptor::DebugName() const {
   return "";
 }
 
-#if !defined(V8_TARGET_ARCH_MIPS) && !defined(V8_TARGET_ARCH_MIPS64)
 bool CallInterfaceDescriptor::IsValidFloatParameterRegister(Register reg) {
-  return true;
-}
-#endif
-
-void VoidDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  data->InitializePlatformSpecific(0, nullptr);
-}
-
-void AllocateDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {kAllocateSizeRegister};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CEntry1ArgvOnStackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {kRuntimeCallArgCountRegister,
-                          kRuntimeCallFunctionRegister};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-namespace {
-
-void InterpreterCEntryDescriptor_InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {kRuntimeCallArgCountRegister,
-                          kRuntimeCallArgvRegister,
-                          kRuntimeCallFunctionRegister};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-}  // namespace
-
-void InterpreterCEntry1Descriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  InterpreterCEntryDescriptor_InitializePlatformSpecific(data);
-}
-
-void InterpreterCEntry2Descriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  InterpreterCEntryDescriptor_InitializePlatformSpecific(data);
-}
-
-void FastNewObjectDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {TargetRegister(), NewTargetRegister()};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-const Register FastNewObjectDescriptor::TargetRegister() {
-  return kJSFunctionRegister;
-}
-
-const Register FastNewObjectDescriptor::NewTargetRegister() {
-  return kJavaScriptCallNewTargetRegister;
-}
-
-void TailCallOptimizedCodeSlotDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {kJavaScriptCallCodeStartRegister};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void LoadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {ReceiverRegister(), NameRegister(), SlotRegister()};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void LoadBaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {LoadDescriptor::ReceiverRegister(),
-                          LoadDescriptor::NameRegister(),
-                          LoadDescriptor::SlotRegister()};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void LoadNoFeedbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {ReceiverRegister(), NameRegister(), ICKindRegister()};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void LoadGlobalDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {NameRegister(), SlotRegister()};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void LoadGlobalBaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {LoadGlobalDescriptor::NameRegister(),
-                          LoadGlobalDescriptor::SlotRegister()};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void LookupBaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-void LoadGlobalNoFeedbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {NameRegister(), ICKindRegister()};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void LoadGlobalWithVectorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {NameRegister(), SlotRegister(), VectorRegister()};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void LoadWithReceiverAndVectorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DCHECK(!AreAliased(ReceiverRegister(), LookupStartObjectRegister(),
-                     NameRegister(), SlotRegister(), VectorRegister()));
-  Register registers[] = {ReceiverRegister(), LookupStartObjectRegister(),
-                          NameRegister(), SlotRegister(), VectorRegister()};
-  int len = arraysize(registers) - kStackArgumentsCount;
-  data->InitializePlatformSpecific(len, registers);
-}
-
-void LoadWithReceiverBaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      LoadWithReceiverAndVectorDescriptor::ReceiverRegister(),
-      LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister(),
-      LoadWithReceiverAndVectorDescriptor::NameRegister(),
-      LoadWithReceiverAndVectorDescriptor::SlotRegister()};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void StoreGlobalDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {NameRegister(), ValueRegister(), SlotRegister()};
-
-  int len = arraysize(registers) - kStackArgumentsCount;
-  data->InitializePlatformSpecific(len, registers);
-}
-
-void StoreGlobalBaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {StoreGlobalDescriptor::NameRegister(),
-                          StoreGlobalDescriptor::ValueRegister(),
-                          StoreGlobalDescriptor::SlotRegister()};
-
-  int len = arraysize(registers) - kStackArgumentsCount;
-  data->InitializePlatformSpecific(len, registers);
-}
-
-void StoreGlobalWithVectorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {NameRegister(), ValueRegister(), SlotRegister(),
-                          VectorRegister()};
-  int len = arraysize(registers) - kStackArgumentsCount;
-  data->InitializePlatformSpecific(len, registers);
-}
-
-void StoreDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {ReceiverRegister(), NameRegister(), ValueRegister(),
-                          SlotRegister()};
-
-  int len = arraysize(registers) - kStackArgumentsCount;
-  data->InitializePlatformSpecific(len, registers);
-}
-
-void StoreBaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      StoreDescriptor::ReceiverRegister(), StoreDescriptor::NameRegister(),
-      StoreDescriptor::ValueRegister(), StoreDescriptor::SlotRegister()};
-
-  int len = arraysize(registers) - kStackArgumentsCount;
-  data->InitializePlatformSpecific(len, registers);
-}
-
-void StoreTransitionDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      ReceiverRegister(), NameRegister(), MapRegister(),
-      ValueRegister(),    SlotRegister(), VectorRegister(),
-  };
-  int len = arraysize(registers) - kStackArgumentsCount;
-  data->InitializePlatformSpecific(len, registers);
-}
-
-void BaselineOutOfLinePrologueDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // TODO(v8:11421): Implement on other platforms.
-#if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_IA32 || \
-    V8_TARGET_ARCH_ARM
-  Register registers[] = {kContextRegister,
-                          kJSFunctionRegister,
-                          kJavaScriptCallArgCountRegister,
-                          kJavaScriptCallExtraArg1Register,
-                          kJavaScriptCallNewTargetRegister,
-                          kInterpreterBytecodeArrayRegister};
-  data->InitializePlatformSpecific(kParameterCount - kStackArgumentsCount,
-                                   registers);
-#else
-  InitializePlatformUnimplemented(data, kParameterCount);
-#endif
-}
-
-void BaselineLeaveFrameDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // TODO(v8:11421): Implement on other platforms.
-#if V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || \
-    V8_TARGET_ARCH_ARM
-  Register registers[] = {ParamsSizeRegister(), WeightRegister()};
-  data->InitializePlatformSpecific(kParameterCount, registers);
+#if defined(V8_TARGET_ARCH_MIPS) || defined(V8_TARGET_ARCH_MIPS64)
+  return reg.code() % 2 == 0;
 #else
-  InitializePlatformUnimplemented(data, kParameterCount);
-#endif
-}
-
-void StringAtDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-void StringAtAsStringDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-void StringSubstringDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-void TypeConversionDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {ArgumentRegister()};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void TypeConversionNoContextDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {TypeConversionDescriptor::ArgumentRegister()};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void TypeConversion_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-void SingleParameterOnStackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  data->InitializePlatformSpecific(0, nullptr);
-}
-
-void AsyncFunctionStackParameterDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  data->InitializePlatformSpecific(0, nullptr);
-}
-
-void GetIteratorStackParameterDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  data->InitializePlatformSpecific(0, nullptr);
-}
-
-void LoadWithVectorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {ReceiverRegister(), NameRegister(), SlotRegister(),
-                          VectorRegister()};
-  // TODO(jgruber): This DCHECK could be enabled if RegisterBase::ListOf were
-  // to allow no_reg entries.
-  // DCHECK(!AreAliased(ReceiverRegister(), NameRegister(), SlotRegister(),
-  //                    VectorRegister(), kRootRegister));
-  int len = arraysize(registers) - kStackArgumentsCount;
-  data->InitializePlatformSpecific(len, registers);
-}
-
-void StoreWithVectorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {ReceiverRegister(), NameRegister(), ValueRegister(),
-                          SlotRegister(), VectorRegister()};
-  // TODO(jgruber): This DCHECK could be enabled if RegisterBase::ListOf were
-  // to allow no_reg entries.
-  // DCHECK(!AreAliased(ReceiverRegister(), NameRegister(), kRootRegister));
-  int len = arraysize(registers) - kStackArgumentsCount;
-  data->InitializePlatformSpecific(len, registers);
-}
-
-const Register ApiGetterDescriptor::ReceiverRegister() {
-  return LoadDescriptor::ReceiverRegister();
-}
-
-void ApiGetterDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {ReceiverRegister(), HolderRegister(),
-                          CallbackRegister()};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ContextOnlyDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  data->InitializePlatformSpecific(0, nullptr);
-}
-
-void NoContextDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  data->InitializePlatformSpecific(0, nullptr);
-}
-
-void GrowArrayElementsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {ObjectRegister(), KeyRegister()};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ArrayNoArgumentConstructorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // This descriptor must use the same set of registers as the
-  // ArrayNArgumentsConstructorDescriptor.
-  ArrayNArgumentsConstructorDescriptor::InitializePlatformSpecific(data);
-}
-
-void ArraySingleArgumentConstructorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // This descriptor must use the same set of registers as the
-  // ArrayNArgumentsConstructorDescriptor.
-  ArrayNArgumentsConstructorDescriptor::InitializePlatformSpecific(data);
-}
-
-void ArrayNArgumentsConstructorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // Keep the arguments on the same registers as they were in
-  // ArrayConstructorDescriptor to avoid unnecessary register moves.
-  // kFunction, kAllocationSite, kActualArgumentsCount
-  Register registers[] = {kJavaScriptCallTargetRegister,
-                          kJavaScriptCallExtraArg1Register,
-                          kJavaScriptCallArgCountRegister};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-#if !V8_TARGET_ARCH_IA32
-// We need a custom descriptor on ia32 to avoid using xmm0.
-void WasmFloat32ToNumberDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-// We need a custom descriptor on ia32 to avoid using xmm0.
-void WasmFloat64ToNumberDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-#endif  // !V8_TARGET_ARCH_IA32
-
-#if !defined(V8_TARGET_ARCH_MIPS) && !defined(V8_TARGET_ARCH_MIPS64) && \
-    !defined(V8_TARGET_ARCH_RISCV64)
-void WasmI32AtomicWait32Descriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-void WasmI64AtomicWait32Descriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data,
-                                    kParameterCount - kStackArgumentsCount);
-}
+  return true;
 #endif
-
-void CloneObjectWithVectorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-void CloneObjectBaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-// static
-Register RunMicrotasksDescriptor::MicrotaskQueueRegister() {
-  return CallDescriptors::call_descriptor_data(CallDescriptors::RunMicrotasks)
-      ->register_param(0);
-}
-
-void RunMicrotasksDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-void I64ToBigIntDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-void I32PairToBigIntDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-void BigIntToI64Descriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-void BigIntToI32PairDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-void BinaryOp_WithFeedbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, 4);
-}
-
-void CallTrampoline_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-void CallTrampoline_WithFeedbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, 4);
-}
-
-void CallWithArrayLike_WithFeedbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, 4);
-}
-
-void CallWithSpread_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-void CallWithSpread_WithFeedbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, 4);
-}
-
-void ConstructWithArrayLike_WithFeedbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, 4);
-}
-
-void ConstructWithSpread_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data,
-                                    kParameterCount - kStackArgumentsCount);
-}
-
-void ConstructWithSpread_WithFeedbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, 4);
-}
-
-void Compare_WithFeedbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, 4);
-}
-
-void UnaryOp_WithFeedbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, 3);
-}
-
-void UnaryOp_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, 2);
-}
-
-void ForInPrepareDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-void SuspendGeneratorBaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
-}
-
-void ResumeGeneratorBaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  DefaultInitializePlatformSpecific(data, kParameterCount);
 }
 
 }  // namespace internal
diff --git a/chromium/v8/src/codegen/interface-descriptors.h b/chromium/v8/src/codegen/interface-descriptors.h
index 8d03907efc0..e64826e6fc1 100644
--- a/chromium/v8/src/codegen/interface-descriptors.h
+++ b/chromium/v8/src/codegen/interface-descriptors.h
@@ -7,6 +7,7 @@
 
 #include <memory>
 
+#include "src/base/logging.h"
 #include "src/codegen/machine-type.h"
 #include "src/codegen/register-arch.h"
 #include "src/codegen/tnode.h"
@@ -39,6 +40,7 @@ namespace internal {
   V(CallFunctionTemplate)                \
   V(CallTrampoline)                      \
   V(CallTrampoline_Baseline)             \
+  V(CallTrampoline_Baseline_Compact)     \
   V(CallTrampoline_WithFeedback)         \
   V(CallVarargs)                         \
   V(CallWithArrayLike)                   \
@@ -68,7 +70,6 @@ namespace internal {
   V(EphemeronKeyBarrier)                 \
   V(FastNewObject)                       \
   V(ForInPrepare)                        \
-  V(FrameDropperTrampoline)              \
   V(GetIteratorStackParameter)           \
   V(GetProperty)                         \
   V(GrowArrayElements)                   \
@@ -151,17 +152,21 @@ class V8_EXPORT_PRIVATE CallInterfaceDescriptorData {
   };
   using Flags = base::Flags<Flag>;
 
+  static constexpr int kUninitializedCount = -1;
+
   CallInterfaceDescriptorData() = default;
 
   CallInterfaceDescriptorData(const CallInterfaceDescriptorData&) = delete;
   CallInterfaceDescriptorData& operator=(const CallInterfaceDescriptorData&) =
       delete;
 
-  // A copy of the passed in registers and param_representations is made
-  // and owned by the CallInterfaceDescriptorData.
-
-  void InitializePlatformSpecific(int register_parameter_count,
-                                  const Register* registers);
+  // The passed registers are owned by the caller, and their lifetime is
+  // expected to exceed that of this data. In practice, they are expected to
+  // be in a static local.
+  void InitializeRegisters(Flags flags, int return_count, int parameter_count,
+                           StackArgumentOrder stack_order,
+                           int register_parameter_count,
+                           const Register* registers);
 
   // if machine_types is null, then an array of size
   // (return_count + parameter_count) will be created with
@@ -171,17 +176,13 @@ class V8_EXPORT_PRIVATE CallInterfaceDescriptorData {
   // (return_count + parameter_count). Those members of the parameter array will
   // be initialized from {machine_types}, and the rest initialized to
   // MachineType::AnyTagged().
-  void InitializePlatformIndependent(Flags flags, int return_count,
-                                     int parameter_count,
-                                     const MachineType* machine_types,
-                                     int machine_types_length,
-                                     StackArgumentOrder stack_order);
+  void InitializeTypes(const MachineType* machine_types,
+                       int machine_types_length);
 
   void Reset();
 
   bool IsInitialized() const {
-    return IsInitializedPlatformSpecific() &&
-           IsInitializedPlatformIndependent();
+    return IsInitializedRegisters() && IsInitializedTypes();
   }
 
   Flags flags() const { return flags_; }
@@ -189,7 +190,6 @@ class V8_EXPORT_PRIVATE CallInterfaceDescriptorData {
   int param_count() const { return param_count_; }
   int register_param_count() const { return register_param_count_; }
   Register register_param(int index) const { return register_params_[index]; }
-  Register* register_params() const { return register_params_; }
   MachineType return_type(int index) const {
     DCHECK_LT(index, return_count_);
     return machine_types_[index];
@@ -200,9 +200,9 @@ class V8_EXPORT_PRIVATE CallInterfaceDescriptorData {
   }
   StackArgumentOrder stack_order() const { return stack_order_; }
 
-  void RestrictAllocatableRegisters(const Register* registers, int num) {
+  void RestrictAllocatableRegisters(const Register* registers, size_t num) {
     DCHECK_EQ(allocatable_registers_, 0);
-    for (int i = 0; i < num; ++i) {
+    for (size_t i = 0; i < num; ++i) {
       allocatable_registers_ |= registers[i].bit();
     }
     DCHECK_GT(NumRegs(allocatable_registers_), 0);
@@ -211,17 +211,17 @@ class V8_EXPORT_PRIVATE CallInterfaceDescriptorData {
   RegList allocatable_registers() const { return allocatable_registers_; }
 
  private:
-  bool IsInitializedPlatformSpecific() const {
+  bool IsInitializedRegisters() const {
     const bool initialized =
-        (register_param_count_ == 0 && register_params_ == nullptr) ||
-        (register_param_count_ > 0 && register_params_ != nullptr);
-    // Platform-specific initialization happens before platform-independent.
+        return_count_ != kUninitializedCount &&
+        param_count_ != kUninitializedCount &&
+        (register_param_count_ == 0 || register_params_ != nullptr);
+    // Register initialization happens before type initialization.
     return initialized;
   }
-  bool IsInitializedPlatformIndependent() const {
-    const bool initialized =
-        return_count_ >= 0 && param_count_ >= 0 && machine_types_ != nullptr;
-    // Platform-specific initialization happens before platform-independent.
+  bool IsInitializedTypes() const {
+    const bool initialized = machine_types_ != nullptr;
+    // Register initialization happens before type initialization.
     return initialized;
   }
 
@@ -229,9 +229,9 @@ class V8_EXPORT_PRIVATE CallInterfaceDescriptorData {
   bool AllStackParametersAreTagged() const;
 #endif  // DEBUG
 
-  int register_param_count_ = -1;
-  int return_count_ = -1;
-  int param_count_ = -1;
+  int register_param_count_ = kUninitializedCount;
+  int return_count_ = kUninitializedCount;
+  int param_count_ = kUninitializedCount;
   Flags flags_ = kNoFlags;
   StackArgumentOrder stack_order_ = StackArgumentOrder::kDefault;
 
@@ -242,10 +242,10 @@ class V8_EXPORT_PRIVATE CallInterfaceDescriptorData {
   // |registers_params_| defines registers that are used for parameter passing.
   // |machine_types_| defines machine types for resulting values and incomping
   // parameters.
-  // Both arrays are allocated dynamically by the InterfaceDescriptor and
-  // freed on destruction. This is because static arrays cause creation of
-  // runtime static initializers which we don't want.
-  Register* register_params_ = nullptr;
+  // The register params array is owned by the caller, and it's expected that it
+  // is a static local stored in the caller function. The machine types are
+  // allocated dynamically by the InterfaceDescriptor and freed on destruction.
+  const Register* register_params_ = nullptr;
   MachineType* machine_types_ = nullptr;
 };
 
@@ -278,12 +278,35 @@ class V8_EXPORT_PRIVATE CallDescriptors : public AllStatic {
       call_descriptor_data_[NUMBER_OF_DESCRIPTORS];
 };
 
+#if defined(V8_TARGET_ARCH_IA32)
+// To support all possible cases, we must limit the number of register args for
+// TFS builtins on ia32 to 3. Out of the 6 allocatable registers, esi is taken
+// as the context register and ebx is the root register. One register must
+// remain available to store the jump/call target. Thus 3 registers remain for
+// arguments. The reason this applies to TFS builtins specifically is because
+// this becomes relevant for builtins used as targets of Torque function
+// pointers (which must have a register available to store the target).
+// TODO(jgruber): Ideally we should just decrement kMaxBuiltinRegisterParams but
+// that comes with its own set of complications. It's possible, but requires
+// refactoring the calling convention of other existing stubs.
+constexpr int kMaxBuiltinRegisterParams = 4;
+constexpr int kMaxTFSBuiltinRegisterParams = 3;
+#else
+constexpr int kMaxBuiltinRegisterParams = 5;
+constexpr int kMaxTFSBuiltinRegisterParams = kMaxBuiltinRegisterParams;
+#endif
+STATIC_ASSERT(kMaxTFSBuiltinRegisterParams <= kMaxBuiltinRegisterParams);
+constexpr int kJSBuiltinRegisterParams = 4;
+
+// Polymorphic base class for call interface descriptors, which defines getters
+// for the various descriptor properties via a runtime-loaded
+// CallInterfaceDescriptorData field.
 class V8_EXPORT_PRIVATE CallInterfaceDescriptor {
  public:
   using Flags = CallInterfaceDescriptorData::Flags;
 
   CallInterfaceDescriptor() : data_(nullptr) {}
-  virtual ~CallInterfaceDescriptor() = default;
+  ~CallInterfaceDescriptor() = default;
 
   explicit CallInterfaceDescriptor(CallDescriptors::Key key)
       : data_(CallDescriptors::call_descriptor_data(key)) {}
@@ -333,7 +356,9 @@ class V8_EXPORT_PRIVATE CallInterfaceDescriptor {
     return data()->stack_order();
   }
 
-  static const Register ContextRegister();
+  static constexpr inline Register ContextRegister() {
+    return kContextRegister;
+  }
 
   const char* DebugName() const;
 
@@ -344,39 +369,13 @@ class V8_EXPORT_PRIVATE CallInterfaceDescriptor {
  protected:
   const CallInterfaceDescriptorData* data() const { return data_; }
 
-  virtual void InitializePlatformSpecific(CallInterfaceDescriptorData* data) {
-    UNREACHABLE();
-  }
-
-  // Initializes |data| to an unspecified state, for platforms that haven't
-  // implemented a given builtin.
-  static void InitializePlatformUnimplemented(CallInterfaceDescriptorData* data,
-                                              int register_parameter_count) {
-    DefaultInitializePlatformSpecific(data,
-                                      std::min(register_parameter_count, 4));
-  }
-
-  virtual void InitializePlatformIndependent(
-      CallInterfaceDescriptorData* data) {
-    // Default descriptor configuration: one result, all parameters are passed
-    // in registers and all parameters have MachineType::AnyTagged() type.
-    data->InitializePlatformIndependent(
-        CallInterfaceDescriptorData::kNoFlags, 1, data->register_param_count(),
-        nullptr, 0, StackArgumentOrder::kDefault);
-  }
-
-  // Initializes |data| using the platform dependent default set of registers.
-  // It is intended to be used for TurboFan stubs when particular set of
-  // registers does not matter.
-  static void DefaultInitializePlatformSpecific(
-      CallInterfaceDescriptorData* data, int register_parameter_count);
-
-  // Initializes |data| using the platform dependent default set of registers
-  // for JavaScript-compatible calling convention.
-  // It is intended to be used for TurboFan stubs being called with JavaScript
-  // linkage + additional parameters on registers and stack.
-  static void JSDefaultInitializePlatformSpecific(
-      CallInterfaceDescriptorData* data, int non_js_register_parameter_count);
+  // Helper for defining the default register set.
+  //
+  // Use auto for the return type to allow different architectures to have
+  // differently sized default register arrays.
+  static constexpr inline auto DefaultRegisterArray();
+  static constexpr inline std::array<Register, kJSBuiltinRegisterParams>
+  DefaultJSRegisterArray();
 
   // Checks if float parameters are not assigned invalid registers.
   bool CheckFloatingPointParameters(CallInterfaceDescriptorData* data) {
@@ -393,104 +392,164 @@ class V8_EXPORT_PRIVATE CallInterfaceDescriptor {
   bool IsValidFloatParameterRegister(Register reg);
 
  private:
+  const CallInterfaceDescriptorData* data_;
+};
+
+// CRTP base class for call interface descriptors, which defines static getters
+// for the various descriptor properties based on static values defined in the
+// subclass.
+template <typename DerivedDescriptor>
+class StaticCallInterfaceDescriptor : public CallInterfaceDescriptor {
+ public:
+  // ===========================================================================
+  // The following are the descriptor's CRTP configuration points, overwritable
+  // by DerivedDescriptor.
+  static constexpr int kReturnCount =
+      CallInterfaceDescriptorData::kUninitializedCount;
+  static constexpr int kParameterCount =
+      CallInterfaceDescriptorData::kUninitializedCount;
+  static constexpr bool kNoContext = false;
+  static constexpr bool kAllowVarArgs = false;
+  static constexpr bool kNoStackScan = false;
+  static constexpr auto kStackArgumentOrder = StackArgumentOrder::kDefault;
+
+  // The set of registers available to the parameters, as a
+  // std::array<Register,N>. Can be larger or smaller than kParameterCount; if
+  // larger then any remaining registers are ignored; if smaller, any parameters
+  // after registers().size() will be stack registers.
+  //
+  // Defaults to CallInterfaceDescriptor::DefaultRegisterArray().
+  static constexpr inline auto registers();
+
+  // An additional limit on the number of register parameters allowed. This is
+  // here so that it can be overwritten to kMaxTFSBuiltinRegisterParams for TFS
+  // builtins, see comment on kMaxTFSBuiltinRegisterParams above.
+  static constexpr int kMaxRegisterParams = kMaxBuiltinRegisterParams;
+
+  // If set to true, the descriptor will restrict the set of allocatable
+  // registers to the set returned by registers(). Then, it is expected that
+  // the first kParameterCount registers() are the parameters of the builtin.
+  static constexpr bool kRestrictAllocatableRegisters = false;
+
+  // End of customization points.
+  // ===========================================================================
+
+  static constexpr inline Flags flags() {
+    return Flags((DerivedDescriptor::kNoContext
+                      ? CallInterfaceDescriptorData::kNoContext
+                      : 0) |
+                 (DerivedDescriptor::kAllowVarArgs
+                      ? CallInterfaceDescriptorData::kAllowVarArgs
+                      : 0) |
+                 (DerivedDescriptor::kNoStackScan
+                      ? CallInterfaceDescriptorData::kNoStackScan
+                      : 0));
+  }
+  static constexpr inline bool AllowVarArgs() {
+    return DerivedDescriptor::kAllowVarArgs;
+  }
+  static constexpr inline bool HasContextParameter() {
+    return !DerivedDescriptor::kNoContext;
+  }
+
+  static constexpr inline int GetReturnCount();
+  static constexpr inline int GetParameterCount();
+  static constexpr inline int GetRegisterParameterCount();
+  static constexpr inline int GetStackParameterCount();
+  static constexpr inline Register* GetRegisterData();
+
+  static constexpr inline Register GetRegisterParameter(int i) {
+    return DerivedDescriptor::registers()[i];
+  }
+
+  explicit StaticCallInterfaceDescriptor(CallDescriptors::Key key)
+      : CallInterfaceDescriptor(key) {}
+
+ private:
   // {CallDescriptors} is allowed to call the private {Initialize} method.
   friend class CallDescriptors;
 
-  const CallInterfaceDescriptorData* data_;
+  inline void Initialize(CallInterfaceDescriptorData* data);
 
-  void Initialize(CallInterfaceDescriptorData* data) {
-    // The passed pointer should be a modifiable pointer to our own data.
-    DCHECK_EQ(data, data_);
-    DCHECK(!data->IsInitialized());
-    InitializePlatformSpecific(data);
-    InitializePlatformIndependent(data);
-    DCHECK(data->IsInitialized());
-    DCHECK(CheckFloatingPointParameters(data));
+  // Set up the types of the descriptor. This is a static function, so that it
+  // is overwritable by subclasses. By default, all parameters have
+  // MachineType::AnyTagged() type.
+  static void InitializeTypes(CallInterfaceDescriptorData* data) {
+    data->InitializeTypes(nullptr, 0);
   }
 };
 
-#define DECLARE_DESCRIPTOR_WITH_BASE(name, base) \
- public:                                         \
-  explicit name() : base(key()) {}               \
-  static inline CallDescriptors::Key key();
+template <typename Descriptor>
+class StaticJSCallInterfaceDescriptor
+    : public StaticCallInterfaceDescriptor<Descriptor> {
+ public:
+  static constexpr auto kStackArgumentOrder = StackArgumentOrder::kJS;
+  static constexpr inline auto registers();
 
-#if defined(V8_TARGET_ARCH_IA32)
-// To support all possible cases, we must limit the number of register args for
-// TFS builtins on ia32 to 3. Out of the 6 allocatable registers, esi is taken
-// as the context register and ebx is the root register. One register must
-// remain available to store the jump/call target. Thus 3 registers remain for
-// arguments. The reason this applies to TFS builtins specifically is because
-// this becomes relevant for builtins used as targets of Torque function
-// pointers (which must have a register available to store the target).
-// TODO(jgruber): Ideally we should just decrement kMaxBuiltinRegisterParams but
-// that comes with its own set of complications. It's possible, but requires
-// refactoring the calling convention of other existing stubs.
-constexpr int kMaxBuiltinRegisterParams = 4;
-constexpr int kMaxTFSBuiltinRegisterParams = 3;
-#else
-constexpr int kMaxBuiltinRegisterParams = 5;
-constexpr int kMaxTFSBuiltinRegisterParams = kMaxBuiltinRegisterParams;
-#endif
-STATIC_ASSERT(kMaxTFSBuiltinRegisterParams <= kMaxBuiltinRegisterParams);
+  using StaticCallInterfaceDescriptor<
+      Descriptor>::StaticCallInterfaceDescriptor;
+};
 
-#define DECLARE_DEFAULT_DESCRIPTOR(name, base)                                 \
-  DECLARE_DESCRIPTOR_WITH_BASE(name, base)                                     \
- protected:                                                                    \
-  static const int kRegisterParams =                                           \
-      kParameterCount > kMaxTFSBuiltinRegisterParams                           \
-          ? kMaxTFSBuiltinRegisterParams                                       \
-          : kParameterCount;                                                   \
-  static const int kStackParams = kParameterCount - kRegisterParams;           \
-  void InitializePlatformSpecific(CallInterfaceDescriptorData* data)           \
-      override {                                                               \
-    DefaultInitializePlatformSpecific(data, kRegisterParams);                  \
-  }                                                                            \
-  void InitializePlatformIndependent(CallInterfaceDescriptorData* data)        \
-      override {                                                               \
-    data->InitializePlatformIndependent(Flags(kDescriptorFlags), kReturnCount, \
-                                        kParameterCount, nullptr, 0,           \
-                                        kStackArgumentOrder);                  \
-  }                                                                            \
-  name(CallDescriptors::Key key) : base(key) {}                                \
-                                                                               \
- public:
-
-#define DECLARE_JS_COMPATIBLE_DESCRIPTOR(name, base,                        \
-                                         non_js_reg_parameters_count)       \
-  DECLARE_DESCRIPTOR_WITH_BASE(name, base)                                  \
- protected:                                                                 \
-  void InitializePlatformSpecific(CallInterfaceDescriptorData* data)        \
-      override {                                                            \
-    JSDefaultInitializePlatformSpecific(data, non_js_reg_parameters_count); \
-  }                                                                         \
-  name(CallDescriptors::Key key) : base(key) {}                             \
-                                                                            \
- public:
-
-#define DEFINE_FLAGS_AND_RESULT_AND_PARAMETERS(flags, stack_order,       \
-                                               return_count, ...)        \
-  static constexpr int kDescriptorFlags = flags;                         \
-  static constexpr int kReturnCount = return_count;                      \
-  static constexpr StackArgumentOrder kStackArgumentOrder = stack_order; \
-  enum ParameterIndices {                                                \
-    __dummy = -1, /* to be able to pass zero arguments */                \
-    ##__VA_ARGS__,                                                       \
-                                                                         \
-    kParameterCount,                                                     \
-    kContext = kParameterCount /* implicit parameter */                  \
-  };
+template <Builtins::Name kBuiltin>
+struct CallInterfaceDescriptorFor;
+
+// Stub class replacing std::array<Register, 0>, as a workaround for MSVC's
+// https://github.com/microsoft/STL/issues/942
+struct EmptyRegisterArray {
+  Register* data() { return nullptr; }
+  size_t size() const { return 0; }
+  Register operator[](size_t i) const { UNREACHABLE(); }
+};
 
-#define DEFINE_RESULT_AND_PARAMETERS(return_count, ...)                    \
-  DEFINE_FLAGS_AND_RESULT_AND_PARAMETERS(                                  \
-      CallInterfaceDescriptorData::kNoFlags, StackArgumentOrder::kDefault, \
-      return_count, ##__VA_ARGS__)
+// Helper method for defining an array of registers for the various
+// Descriptor::registers() methods.
+template <typename... Registers>
+constexpr std::array<Register, 1 + sizeof...(Registers)> RegisterArray(
+    Register first_reg, Registers... regs) {
+  return {first_reg, regs...};
+}
+constexpr EmptyRegisterArray RegisterArray() { return {}; }
+
+#define DECLARE_DESCRIPTOR_WITH_BASE(name, base)                  \
+ public:                                                          \
+  /* StaticCallInterfaceDescriptor can call Initialize methods */ \
+  friend class StaticCallInterfaceDescriptor<name>;               \
+  explicit name() : base(key()) {}                                \
+  static inline CallDescriptors::Key key();
+
+#define DECLARE_DEFAULT_DESCRIPTOR(name)                                  \
+  DECLARE_DESCRIPTOR_WITH_BASE(name, StaticCallInterfaceDescriptor)       \
+  static constexpr int kMaxRegisterParams = kMaxTFSBuiltinRegisterParams; \
+                                                                          \
+ protected:                                                               \
+  explicit name(CallDescriptors::Key key)                                 \
+      : StaticCallInterfaceDescriptor(key) {}                             \
+                                                                          \
+ public:
+
+#define DECLARE_JS_COMPATIBLE_DESCRIPTOR(name)                        \
+  DECLARE_DESCRIPTOR_WITH_BASE(name, StaticJSCallInterfaceDescriptor) \
+ protected:                                                           \
+  explicit name(CallDescriptors::Key key)                             \
+      : StaticJSCallInterfaceDescriptor(key) {}                       \
+                                                                      \
+ public:
+
+#define DEFINE_RESULT_AND_PARAMETERS(return_count, ...)   \
+  static constexpr int kReturnCount = return_count;       \
+  enum ParameterIndices {                                 \
+    __dummy = -1, /* to be able to pass zero arguments */ \
+    ##__VA_ARGS__,                                        \
+                                                          \
+    kParameterCount,                                      \
+    kContext = kParameterCount /* implicit parameter */   \
+  };
 
 // This is valid only for builtins that use EntryFrame, which does not scan
 // stack arguments on GC.
 #define DEFINE_PARAMETERS_ENTRY(...)                        \
-  static constexpr int kDescriptorFlags =                   \
-      CallInterfaceDescriptorData::kNoContext |             \
-      CallInterfaceDescriptorData::kNoStackScan;            \
+  static constexpr bool kNoContext = true;                  \
+  static constexpr bool kNoStackScan = true;                \
   static constexpr StackArgumentOrder kStackArgumentOrder = \
       StackArgumentOrder::kDefault;                         \
   static constexpr int kReturnCount = 1;                    \
@@ -501,37 +560,37 @@ STATIC_ASSERT(kMaxTFSBuiltinRegisterParams <= kMaxBuiltinRegisterParams);
     kParameterCount                                         \
   };
 
-#define DEFINE_PARAMETERS(...)                                                \
-  DEFINE_FLAGS_AND_RESULT_AND_PARAMETERS(                                     \
-      CallInterfaceDescriptorData::kNoFlags, StackArgumentOrder::kDefault, 1, \
-      ##__VA_ARGS__)
+#define DEFINE_PARAMETERS(...) DEFINE_RESULT_AND_PARAMETERS(1, ##__VA_ARGS__)
+
+#define DEFINE_PARAMETERS_NO_CONTEXT(...) \
+  DEFINE_PARAMETERS(__VA_ARGS__)          \
+  static constexpr bool kNoContext = true;
+
+#define DEFINE_PARAMETERS_VARARGS(...)                      \
+  DEFINE_PARAMETERS(__VA_ARGS__)                            \
+  static constexpr bool kAllowVarArgs = true;               \
+  static constexpr StackArgumentOrder kStackArgumentOrder = \
+      StackArgumentOrder::kJS;
 
-#define DEFINE_PARAMETERS_NO_CONTEXT(...)                                    \
-  DEFINE_FLAGS_AND_RESULT_AND_PARAMETERS(                                    \
-      CallInterfaceDescriptorData::kNoContext, StackArgumentOrder::kDefault, \
-      1, ##__VA_ARGS__)
+#define DEFINE_PARAMETERS_NO_CONTEXT_VARARGS(...)           \
+  DEFINE_PARAMETERS_NO_CONTEXT(__VA_ARGS__)                 \
+  static constexpr bool kAllowVarArgs = true;               \
+  static constexpr StackArgumentOrder kStackArgumentOrder = \
+      StackArgumentOrder::kJS;
 
-#define DEFINE_PARAMETERS_VARARGS(...)                                        \
-  DEFINE_FLAGS_AND_RESULT_AND_PARAMETERS(                                     \
-      CallInterfaceDescriptorData::kAllowVarArgs, StackArgumentOrder::kJS, 1, \
-      ##__VA_ARGS__)
+#define DEFINE_RESULT_AND_PARAMETERS_NO_CONTEXT(return_count, ...) \
+  DEFINE_RESULT_AND_PARAMETERS(return_count, ##__VA_ARGS__)        \
+  static constexpr bool kNoContext = true;
 
-#define DEFINE_RESULT_AND_PARAMETER_TYPES_WITH_FLAG(flag, ...)                \
-  void InitializePlatformIndependent(CallInterfaceDescriptorData* data)       \
-      override {                                                              \
+#define DEFINE_RESULT_AND_PARAMETER_TYPES(...)                                \
+  static void InitializeTypes(CallInterfaceDescriptorData* data) {            \
     MachineType machine_types[] = {__VA_ARGS__};                              \
     static_assert(                                                            \
         kReturnCount + kParameterCount == arraysize(machine_types),           \
         "Parameter names definition is not consistent with parameter types"); \
-    data->InitializePlatformIndependent(                                      \
-        Flags(flag | kDescriptorFlags), kReturnCount, kParameterCount,        \
-        machine_types, arraysize(machine_types), kStackArgumentOrder);        \
+    data->InitializeTypes(machine_types, arraysize(machine_types));           \
   }
 
-#define DEFINE_RESULT_AND_PARAMETER_TYPES(...) \
-  DEFINE_RESULT_AND_PARAMETER_TYPES_WITH_FLAG( \
-      CallInterfaceDescriptorData::kNoFlags, __VA_ARGS__)
-
 #define DEFINE_PARAMETER_TYPES(...)                                        \
   DEFINE_RESULT_AND_PARAMETER_TYPES(MachineType::AnyTagged() /* result */, \
                                     ##__VA_ARGS__)
@@ -539,8 +598,7 @@ STATIC_ASSERT(kMaxTFSBuiltinRegisterParams <= kMaxBuiltinRegisterParams);
 // When the extra arguments described here are located in the stack, they are
 // just above the return address in the frame (first arguments).
 #define DEFINE_JS_PARAMETERS(...)                           \
-  static constexpr int kDescriptorFlags =                   \
-      CallInterfaceDescriptorData::kAllowVarArgs;           \
+  static constexpr bool kAllowVarArgs = true;               \
   static constexpr int kReturnCount = 1;                    \
   static constexpr StackArgumentOrder kStackArgumentOrder = \
       StackArgumentOrder::kJS;                              \
@@ -554,9 +612,8 @@ STATIC_ASSERT(kMaxTFSBuiltinRegisterParams <= kMaxBuiltinRegisterParams);
   };
 
 #define DEFINE_JS_PARAMETERS_NO_CONTEXT(...)                \
-  static constexpr int kDescriptorFlags =                   \
-      CallInterfaceDescriptorData::kAllowVarArgs |          \
-      CallInterfaceDescriptorData::kNoContext;              \
+  static constexpr bool kAllowVarArgs = true;               \
+  static constexpr bool kNoContext = true;                  \
   static constexpr int kReturnCount = 1;                    \
   static constexpr StackArgumentOrder kStackArgumentOrder = \
       StackArgumentOrder::kJS;                              \
@@ -574,63 +631,22 @@ STATIC_ASSERT(kMaxTFSBuiltinRegisterParams <= kMaxBuiltinRegisterParams);
                          MachineType::Int32(),     /* kActualArgumentsCount */ \
                          ##__VA_ARGS__)
 
-#define DECLARE_DESCRIPTOR(name, base)                                         \
-  DECLARE_DESCRIPTOR_WITH_BASE(name, base)                                     \
- protected:                                                                    \
-  void InitializePlatformSpecific(CallInterfaceDescriptorData* data) override; \
-  name(CallDescriptors::Key key) : base(key) {}                                \
-                                                                               \
+#define DECLARE_DESCRIPTOR(name)                                    \
+  DECLARE_DESCRIPTOR_WITH_BASE(name, StaticCallInterfaceDescriptor) \
+ protected:                                                         \
+  explicit name(CallDescriptors::Key key)                           \
+      : StaticCallInterfaceDescriptor(key) {}                       \
+                                                                    \
  public:
 
-class V8_EXPORT_PRIVATE VoidDescriptor : public CallInterfaceDescriptor {
+class V8_EXPORT_PRIVATE VoidDescriptor
+    : public StaticCallInterfaceDescriptor<VoidDescriptor> {
  public:
   DEFINE_PARAMETERS()
   DEFINE_PARAMETER_TYPES()
-  DECLARE_DESCRIPTOR(VoidDescriptor, CallInterfaceDescriptor)
-};
-
-// This class is subclassed by Torque-generated call interface descriptors.
-template <int return_count, int parameter_count, bool has_context_parameter>
-class TorqueInterfaceDescriptor : public CallInterfaceDescriptor {
- public:
-  static constexpr int kDescriptorFlags =
-      has_context_parameter ? CallInterfaceDescriptorData::kNoFlags
-                            : CallInterfaceDescriptorData::kNoContext;
-  static constexpr int kParameterCount = parameter_count;
-  enum ParameterIndices { kContext = kParameterCount };
-  template <int i>
-  static ParameterIndices ParameterIndex() {
-    STATIC_ASSERT(0 <= i && i < kParameterCount);
-    return static_cast<ParameterIndices>(i);
-  }
-  static constexpr int kReturnCount = return_count;
-
-  using CallInterfaceDescriptor::CallInterfaceDescriptor;
+  DECLARE_DESCRIPTOR(VoidDescriptor)
 
- protected:
-  static const int kRegisterParams =
-      kParameterCount > kMaxTFSBuiltinRegisterParams
-          ? kMaxTFSBuiltinRegisterParams
-          : kParameterCount;
-  static const int kStackParams = kParameterCount - kRegisterParams;
-  virtual std::vector<MachineType> ReturnType() = 0;
-  virtual std::array<MachineType, kParameterCount> ParameterTypes() = 0;
-  void InitializePlatformSpecific(CallInterfaceDescriptorData* data) override {
-    DefaultInitializePlatformSpecific(data, kRegisterParams);
-  }
-  void InitializePlatformIndependent(
-      CallInterfaceDescriptorData* data) override {
-    std::vector<MachineType> machine_types = ReturnType();
-    DCHECK_EQ(kReturnCount, machine_types.size());
-    auto parameter_types = ParameterTypes();
-    machine_types.insert(machine_types.end(), parameter_types.begin(),
-                         parameter_types.end());
-    DCHECK_EQ(kReturnCount + kParameterCount, machine_types.size());
-    data->InitializePlatformIndependent(Flags(kDescriptorFlags), kReturnCount,
-                                        kParameterCount, machine_types.data(),
-                                        static_cast<int>(machine_types.size()),
-                                        StackArgumentOrder::kDefault);
-  }
+  static constexpr auto registers();
 };
 
 // Dummy descriptor used to mark builtins that don't yet have their proper
@@ -646,180 +662,171 @@ using CCallDescriptor = VoidDescriptor;
 // here.
 using DeoptimizationEntryDescriptor = VoidDescriptor;
 
-class AllocateDescriptor : public CallInterfaceDescriptor {
+class AllocateDescriptor
+    : public StaticCallInterfaceDescriptor<AllocateDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kRequestedSize)
   DEFINE_RESULT_AND_PARAMETER_TYPES(MachineType::TaggedPointer(),  // result 1
                                     MachineType::IntPtr())  // kRequestedSize
-  DECLARE_DESCRIPTOR(AllocateDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(AllocateDescriptor)
+
+  static constexpr auto registers();
 };
 
 // This descriptor defines the JavaScript calling convention that can be used
 // by stubs: target, new.target, argc (not including the receiver) and context
 // are passed in registers while receiver and the rest of the JS arguments are
 // passed on the stack.
-class JSTrampolineDescriptor : public CallInterfaceDescriptor {
+class JSTrampolineDescriptor
+    : public StaticJSCallInterfaceDescriptor<JSTrampolineDescriptor> {
  public:
   DEFINE_JS_PARAMETERS()
   DEFINE_JS_PARAMETER_TYPES()
 
-  DECLARE_JS_COMPATIBLE_DESCRIPTOR(JSTrampolineDescriptor,
-                                   CallInterfaceDescriptor, 0)
+  DECLARE_JS_COMPATIBLE_DESCRIPTOR(JSTrampolineDescriptor)
 };
 
-class ContextOnlyDescriptor : public CallInterfaceDescriptor {
+class ContextOnlyDescriptor
+    : public StaticCallInterfaceDescriptor<ContextOnlyDescriptor> {
  public:
   DEFINE_PARAMETERS()
   DEFINE_PARAMETER_TYPES()
-  DECLARE_DESCRIPTOR(ContextOnlyDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(ContextOnlyDescriptor)
+
+  static constexpr auto registers();
 };
 
-class NoContextDescriptor : public CallInterfaceDescriptor {
+class NoContextDescriptor
+    : public StaticCallInterfaceDescriptor<NoContextDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT()
   DEFINE_PARAMETER_TYPES()
-  DECLARE_DESCRIPTOR(NoContextDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(NoContextDescriptor)
+
+  static constexpr auto registers();
 };
 
 // LoadDescriptor is used by all stubs that implement Load/KeyedLoad ICs.
-class LoadDescriptor : public CallInterfaceDescriptor {
+class LoadDescriptor : public StaticCallInterfaceDescriptor<LoadDescriptor> {
  public:
   DEFINE_PARAMETERS(kReceiver, kName, kSlot)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),     // kReceiver
                          MachineType::AnyTagged(),     // kName
                          MachineType::TaggedSigned())  // kSlot
-  DECLARE_DESCRIPTOR(LoadDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(LoadDescriptor)
+
+  static constexpr inline Register ReceiverRegister();
+  static constexpr inline Register NameRegister();
+  static constexpr inline Register SlotRegister();
 
-  static const Register ReceiverRegister();
-  static const Register NameRegister();
-  static const Register SlotRegister();
+  static constexpr auto registers();
 };
 
 // LoadBaselineDescriptor is a load descriptor that does not take a context as
 // input.
-class LoadBaselineDescriptor : public CallInterfaceDescriptor {
+class LoadBaselineDescriptor
+    : public StaticCallInterfaceDescriptor<LoadBaselineDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kReceiver, kName, kSlot)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),     // kReceiver
                          MachineType::AnyTagged(),     // kName
                          MachineType::TaggedSigned())  // kSlot
-  DECLARE_DESCRIPTOR(LoadBaselineDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(LoadBaselineDescriptor)
+
+  static constexpr auto registers();
 };
 
-class LoadGlobalNoFeedbackDescriptor : public CallInterfaceDescriptor {
+class LoadGlobalNoFeedbackDescriptor
+    : public StaticCallInterfaceDescriptor<LoadGlobalNoFeedbackDescriptor> {
  public:
   DEFINE_PARAMETERS(kName, kICKind)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),     // kName
                          MachineType::TaggedSigned())  // kICKind
-  DECLARE_DESCRIPTOR(LoadGlobalNoFeedbackDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(LoadGlobalNoFeedbackDescriptor)
 
-  static const Register NameRegister() {
-    return LoadDescriptor::NameRegister();
-  }
+  static constexpr inline Register ICKindRegister();
 
-  static const Register ICKindRegister() {
-    return LoadDescriptor::SlotRegister();
-  }
+  static constexpr auto registers();
 };
 
-class LoadNoFeedbackDescriptor : public LoadGlobalNoFeedbackDescriptor {
+class LoadNoFeedbackDescriptor
+    : public StaticCallInterfaceDescriptor<LoadNoFeedbackDescriptor> {
  public:
   DEFINE_PARAMETERS(kReceiver, kName, kICKind)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),     // kReceiver
                          MachineType::AnyTagged(),     // kName
                          MachineType::TaggedSigned())  // kICKind
-  DECLARE_DESCRIPTOR(LoadNoFeedbackDescriptor, LoadGlobalNoFeedbackDescriptor)
-
-  static const Register ReceiverRegister() {
-    return LoadDescriptor::ReceiverRegister();
-  }
+  DECLARE_DESCRIPTOR(LoadNoFeedbackDescriptor)
 
-  static const Register NameRegister() {
-    return LoadGlobalNoFeedbackDescriptor::NameRegister();
-  }
+  static constexpr inline Register ICKindRegister();
 
-  static const Register ICKindRegister() {
-    return LoadGlobalNoFeedbackDescriptor::ICKindRegister();
-  }
+  static constexpr auto registers();
 };
 
-class LoadGlobalDescriptor : public CallInterfaceDescriptor {
+class LoadGlobalDescriptor
+    : public StaticCallInterfaceDescriptor<LoadGlobalDescriptor> {
  public:
   DEFINE_PARAMETERS(kName, kSlot)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),     // kName
                          MachineType::TaggedSigned())  // kSlot
-  DECLARE_DESCRIPTOR(LoadGlobalDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(LoadGlobalDescriptor)
 
-  static const Register NameRegister() {
-    return LoadDescriptor::NameRegister();
-  }
-
-  static const Register SlotRegister() {
-    return LoadDescriptor::SlotRegister();
-  }
+  static constexpr auto registers();
 };
 
-class LoadGlobalBaselineDescriptor : public CallInterfaceDescriptor {
+class LoadGlobalBaselineDescriptor
+    : public StaticCallInterfaceDescriptor<LoadGlobalBaselineDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kName, kSlot)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),     // kName
                          MachineType::TaggedSigned())  // kSlot
-  DECLARE_DESCRIPTOR(LoadGlobalBaselineDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(LoadGlobalBaselineDescriptor)
+
+  static constexpr auto registers();
 };
 
-class LookupBaselineDescriptor : public CallInterfaceDescriptor {
+class LookupBaselineDescriptor
+    : public StaticCallInterfaceDescriptor<LookupBaselineDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kName, kDepth, kSlot)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kName
                          MachineType::AnyTagged(),  // kDepth
                          MachineType::AnyTagged())  // kSlot
-  DECLARE_DESCRIPTOR(LookupBaselineDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(LookupBaselineDescriptor)
 };
 
-class StoreDescriptor : public CallInterfaceDescriptor {
+class StoreDescriptor : public StaticCallInterfaceDescriptor<StoreDescriptor> {
  public:
   DEFINE_PARAMETERS(kReceiver, kName, kValue, kSlot)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),     // kReceiver
                          MachineType::AnyTagged(),     // kName
                          MachineType::AnyTagged(),     // kValue
                          MachineType::TaggedSigned())  // kSlot
-  DECLARE_DESCRIPTOR(StoreDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(StoreDescriptor)
 
-  static const Register ReceiverRegister();
-  static const Register NameRegister();
-  static const Register ValueRegister();
-  static const Register SlotRegister();
+  static constexpr inline Register ReceiverRegister();
+  static constexpr inline Register NameRegister();
+  static constexpr inline Register ValueRegister();
+  static constexpr inline Register SlotRegister();
 
-#if V8_TARGET_ARCH_IA32
-  static const bool kPassLastArgsOnStack = true;
-#else
-  static const bool kPassLastArgsOnStack = false;
-#endif
-
-  // Pass value and slot through the stack.
-  static const int kStackArgumentsCount = kPassLastArgsOnStack ? 2 : 0;
+  static constexpr auto registers();
 };
 
-class StoreBaselineDescriptor : public CallInterfaceDescriptor {
+class StoreBaselineDescriptor
+    : public StaticCallInterfaceDescriptor<StoreBaselineDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kReceiver, kName, kValue, kSlot)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),     // kReceiver
                          MachineType::AnyTagged(),     // kName
                          MachineType::AnyTagged(),     // kValue
                          MachineType::TaggedSigned())  // kSlot
-  DECLARE_DESCRIPTOR(StoreBaselineDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(StoreBaselineDescriptor)
 
-#if V8_TARGET_ARCH_IA32
-  static const bool kPassLastArgsOnStack = true;
-#else
-  static const bool kPassLastArgsOnStack = false;
-#endif
-
-  // Pass value and slot through the stack.
-  static const int kStackArgumentsCount = kPassLastArgsOnStack ? 2 : 0;
+  static constexpr auto registers();
 };
 
-class StoreTransitionDescriptor : public StoreDescriptor {
+class StoreTransitionDescriptor
+    : public StaticCallInterfaceDescriptor<StoreTransitionDescriptor> {
  public:
   DEFINE_PARAMETERS(kReceiver, kName, kMap, kValue, kSlot, kVector)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),     // kReceiver
@@ -828,17 +835,15 @@ class StoreTransitionDescriptor : public StoreDescriptor {
                          MachineType::AnyTagged(),     // kValue
                          MachineType::TaggedSigned(),  // kSlot
                          MachineType::AnyTagged())     // kVector
-  DECLARE_DESCRIPTOR(StoreTransitionDescriptor, StoreDescriptor)
+  DECLARE_DESCRIPTOR(StoreTransitionDescriptor)
 
-  static const Register MapRegister();
-  static const Register SlotRegister();
-  static const Register VectorRegister();
+  static constexpr inline Register MapRegister();
 
-  // Pass value, slot and vector through the stack.
-  static const int kStackArgumentsCount = kPassLastArgsOnStack ? 3 : 0;
+  static constexpr auto registers();
 };
 
-class StoreWithVectorDescriptor : public StoreDescriptor {
+class StoreWithVectorDescriptor
+    : public StaticCallInterfaceDescriptor<StoreWithVectorDescriptor> {
  public:
   DEFINE_PARAMETERS(kReceiver, kName, kValue, kSlot, kVector)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),     // kReceiver
@@ -846,72 +851,52 @@ class StoreWithVectorDescriptor : public StoreDescriptor {
                          MachineType::AnyTagged(),     // kValue
                          MachineType::TaggedSigned(),  // kSlot
                          MachineType::AnyTagged())     // kVector
-  DECLARE_DESCRIPTOR(StoreWithVectorDescriptor, StoreDescriptor)
+  DECLARE_DESCRIPTOR(StoreWithVectorDescriptor)
 
-  static const Register VectorRegister();
+  static constexpr inline Register VectorRegister();
 
-  // Pass value, slot and vector through the stack.
-  static const int kStackArgumentsCount = kPassLastArgsOnStack ? 3 : 0;
+  static constexpr auto registers();
 };
 
-class StoreGlobalDescriptor : public CallInterfaceDescriptor {
+class StoreGlobalDescriptor
+    : public StaticCallInterfaceDescriptor<StoreGlobalDescriptor> {
  public:
   DEFINE_PARAMETERS(kName, kValue, kSlot)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),     // kName
                          MachineType::AnyTagged(),     // kValue
                          MachineType::TaggedSigned())  // kSlot
-  DECLARE_DESCRIPTOR(StoreGlobalDescriptor, CallInterfaceDescriptor)
-
-  static const bool kPassLastArgsOnStack =
-      StoreDescriptor::kPassLastArgsOnStack;
-  // Pass value and slot through the stack.
-  static const int kStackArgumentsCount = kPassLastArgsOnStack ? 2 : 0;
-
-  static const Register NameRegister() {
-    return StoreDescriptor::NameRegister();
-  }
-
-  static const Register ValueRegister() {
-    return StoreDescriptor::ValueRegister();
-  }
+  DECLARE_DESCRIPTOR(StoreGlobalDescriptor)
 
-  static const Register SlotRegister() {
-    return StoreDescriptor::SlotRegister();
-  }
+  static constexpr auto registers();
 };
 
-class StoreGlobalBaselineDescriptor : public CallInterfaceDescriptor {
+class StoreGlobalBaselineDescriptor
+    : public StaticCallInterfaceDescriptor<StoreGlobalBaselineDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kName, kValue, kSlot)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),     // kName
                          MachineType::AnyTagged(),     // kValue
                          MachineType::TaggedSigned())  // kSlot
-  DECLARE_DESCRIPTOR(StoreGlobalBaselineDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(StoreGlobalBaselineDescriptor)
 
-  static const bool kPassLastArgsOnStack =
-      StoreDescriptor::kPassLastArgsOnStack;
-  // Pass value and slot through the stack.
-  static const int kStackArgumentsCount = kPassLastArgsOnStack ? 2 : 0;
+  static constexpr auto registers();
 };
 
-class StoreGlobalWithVectorDescriptor : public StoreGlobalDescriptor {
+class StoreGlobalWithVectorDescriptor
+    : public StaticCallInterfaceDescriptor<StoreGlobalWithVectorDescriptor> {
  public:
   DEFINE_PARAMETERS(kName, kValue, kSlot, kVector)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),     // kName
                          MachineType::AnyTagged(),     // kValue
                          MachineType::TaggedSigned(),  // kSlot
                          MachineType::AnyTagged())     // kVector
-  DECLARE_DESCRIPTOR(StoreGlobalWithVectorDescriptor, StoreGlobalDescriptor)
-
-  static const Register VectorRegister() {
-    return StoreWithVectorDescriptor::VectorRegister();
-  }
+  DECLARE_DESCRIPTOR(StoreGlobalWithVectorDescriptor)
 
-  // Pass value, slot and vector through the stack.
-  static const int kStackArgumentsCount = kPassLastArgsOnStack ? 3 : 0;
+  static constexpr auto registers();
 };
 
-class LoadWithVectorDescriptor : public LoadDescriptor {
+class LoadWithVectorDescriptor
+    : public StaticCallInterfaceDescriptor<LoadWithVectorDescriptor> {
  public:
   // TODO(v8:9497): Revert the Machine type for kSlot to the
   // TaggedSigned once Torque can emit better call descriptors
@@ -920,24 +905,19 @@ class LoadWithVectorDescriptor : public LoadDescriptor {
                          MachineType::AnyTagged(),  // kName
                          MachineType::AnyTagged(),  // kSlot
                          MachineType::AnyTagged())  // kVector
-  DECLARE_DESCRIPTOR(LoadWithVectorDescriptor, LoadDescriptor)
+  DECLARE_DESCRIPTOR(LoadWithVectorDescriptor)
 
-  static const Register VectorRegister();
-
-#if V8_TARGET_ARCH_IA32
-  static const bool kPassLastArgsOnStack = true;
-#else
-  static const bool kPassLastArgsOnStack = false;
-#endif
+  static constexpr inline Register VectorRegister();
 
-  // Pass vector through the stack.
-  static const int kStackArgumentsCount = kPassLastArgsOnStack ? 1 : 0;
+  static constexpr auto registers();
 };
 
 // Like LoadWithVectorDescriptor, except we pass the receiver (the object which
 // should be used as the receiver for accessor function calls) and the lookup
 // start object separately.
-class LoadWithReceiverAndVectorDescriptor : public LoadWithVectorDescriptor {
+class LoadWithReceiverAndVectorDescriptor
+    : public StaticCallInterfaceDescriptor<
+          LoadWithReceiverAndVectorDescriptor> {
  public:
   // TODO(v8:9497): Revert the Machine type for kSlot to the
   // TaggedSigned once Torque can emit better call descriptors
@@ -947,22 +927,15 @@ class LoadWithReceiverAndVectorDescriptor : public LoadWithVectorDescriptor {
                          MachineType::AnyTagged(),  // kName
                          MachineType::AnyTagged(),  // kSlot
                          MachineType::AnyTagged())  // kVector
-  DECLARE_DESCRIPTOR(LoadWithReceiverAndVectorDescriptor,
-                     LoadWithVectorDescriptor)
+  DECLARE_DESCRIPTOR(LoadWithReceiverAndVectorDescriptor)
 
-  static const Register LookupStartObjectRegister();
+  static constexpr inline Register LookupStartObjectRegister();
 
-#if V8_TARGET_ARCH_IA32
-  static const bool kPassLastArgsOnStack = true;
-#else
-  static const bool kPassLastArgsOnStack = false;
-#endif
-
-  // Pass vector through the stack.
-  static const int kStackArgumentsCount = kPassLastArgsOnStack ? 1 : 0;
+  static constexpr auto registers();
 };
 
-class LoadWithReceiverBaselineDescriptor : public LoadBaselineDescriptor {
+class LoadWithReceiverBaselineDescriptor
+    : public StaticCallInterfaceDescriptor<LoadWithReceiverBaselineDescriptor> {
  public:
   // TODO(v8:9497): Revert the Machine type for kSlot to the
   // TaggedSigned once Torque can emit better call descriptors
@@ -971,29 +944,27 @@ class LoadWithReceiverBaselineDescriptor : public LoadBaselineDescriptor {
                          MachineType::AnyTagged(),  // kLookupStartObject
                          MachineType::AnyTagged(),  // kName
                          MachineType::AnyTagged())  // kSlot
-  DECLARE_DESCRIPTOR(LoadWithReceiverBaselineDescriptor, LoadBaselineDescriptor)
+  DECLARE_DESCRIPTOR(LoadWithReceiverBaselineDescriptor)
+
+  static constexpr auto registers();
 };
 
-class LoadGlobalWithVectorDescriptor : public LoadGlobalDescriptor {
+class LoadGlobalWithVectorDescriptor
+    : public StaticCallInterfaceDescriptor<LoadGlobalWithVectorDescriptor> {
  public:
   DEFINE_PARAMETERS(kName, kSlot, kVector)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),     // kName
                          MachineType::TaggedSigned(),  // kSlot
                          MachineType::AnyTagged())     // kVector
-  DECLARE_DESCRIPTOR(LoadGlobalWithVectorDescriptor, LoadGlobalDescriptor)
+  DECLARE_DESCRIPTOR(LoadGlobalWithVectorDescriptor)
 
-#if V8_TARGET_ARCH_IA32
-  // On ia32, LoadWithVectorDescriptor passes vector on the stack and thus we
-  // need to choose a new register here.
-  static const Register VectorRegister() { return edx; }
-#else
-  static const Register VectorRegister() {
-    return LoadWithVectorDescriptor::VectorRegister();
-  }
-#endif
+  static constexpr inline Register VectorRegister();
+
+  static constexpr auto registers();
 };
 
-class DynamicCheckMapsDescriptor final : public CallInterfaceDescriptor {
+class DynamicCheckMapsDescriptor final
+    : public StaticCallInterfaceDescriptor<DynamicCheckMapsDescriptor> {
  public:
   DEFINE_PARAMETERS(kMap, kSlot, kHandler)
   DEFINE_RESULT_AND_PARAMETER_TYPES(MachineType::Int32(),          // return val
@@ -1001,20 +972,28 @@ class DynamicCheckMapsDescriptor final : public CallInterfaceDescriptor {
                                     MachineType::IntPtr(),         // kSlot
                                     MachineType::TaggedSigned())   // kHandler
 
-  DECLARE_DESCRIPTOR(DynamicCheckMapsDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(DynamicCheckMapsDescriptor)
+
+  static constexpr auto registers();
+  static constexpr bool kRestrictAllocatableRegisters = true;
 };
 
-class FastNewObjectDescriptor : public CallInterfaceDescriptor {
+class FastNewObjectDescriptor
+    : public StaticCallInterfaceDescriptor<FastNewObjectDescriptor> {
  public:
   DEFINE_PARAMETERS(kTarget, kNewTarget)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kTarget
                          MachineType::AnyTagged())  // kNewTarget
-  DECLARE_DESCRIPTOR(FastNewObjectDescriptor, CallInterfaceDescriptor)
-  static const Register TargetRegister();
-  static const Register NewTargetRegister();
+  DECLARE_DESCRIPTOR(FastNewObjectDescriptor)
+
+  static constexpr inline Register TargetRegister();
+  static constexpr inline Register NewTargetRegister();
+
+  static constexpr auto registers();
 };
 
-class RecordWriteDescriptor final : public CallInterfaceDescriptor {
+class RecordWriteDescriptor final
+    : public StaticCallInterfaceDescriptor<RecordWriteDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kObject, kSlot, kRememberedSet, kFPMode)
   DEFINE_PARAMETER_TYPES(MachineType::TaggedPointer(),  // kObject
@@ -1022,90 +1001,119 @@ class RecordWriteDescriptor final : public CallInterfaceDescriptor {
                          MachineType::TaggedSigned(),   // kRememberedSet
                          MachineType::TaggedSigned())   // kFPMode
 
-  DECLARE_DESCRIPTOR(RecordWriteDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(RecordWriteDescriptor)
+
+  static constexpr auto registers();
+  static constexpr bool kRestrictAllocatableRegisters = true;
 };
 
-class EphemeronKeyBarrierDescriptor final : public CallInterfaceDescriptor {
+class EphemeronKeyBarrierDescriptor final
+    : public StaticCallInterfaceDescriptor<EphemeronKeyBarrierDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kObject, kSlotAddress, kFPMode)
   DEFINE_PARAMETER_TYPES(MachineType::TaggedPointer(),  // kObject
                          MachineType::Pointer(),        // kSlotAddress
                          MachineType::TaggedSigned())   // kFPMode
 
-  DECLARE_DESCRIPTOR(EphemeronKeyBarrierDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(EphemeronKeyBarrierDescriptor)
+
+  static constexpr auto registers();
+  static constexpr bool kRestrictAllocatableRegisters = true;
 };
 
-class TypeConversionDescriptor final : public CallInterfaceDescriptor {
+class TypeConversionDescriptor final
+    : public StaticCallInterfaceDescriptor<TypeConversionDescriptor> {
  public:
   DEFINE_PARAMETERS(kArgument)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged())
-  DECLARE_DESCRIPTOR(TypeConversionDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(TypeConversionDescriptor)
+
+  static constexpr inline Register ArgumentRegister();
 
-  static const Register ArgumentRegister();
+  static constexpr auto registers();
 };
 
-class TypeConversionNoContextDescriptor final : public CallInterfaceDescriptor {
+class TypeConversionNoContextDescriptor final
+    : public StaticCallInterfaceDescriptor<TypeConversionNoContextDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kArgument)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged())
-  DECLARE_DESCRIPTOR(TypeConversionNoContextDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(TypeConversionNoContextDescriptor)
+
+  static constexpr auto registers();
 };
 
-class TypeConversion_BaselineDescriptor final : public CallInterfaceDescriptor {
+class TypeConversion_BaselineDescriptor final
+    : public StaticCallInterfaceDescriptor<TypeConversion_BaselineDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kArgument, kSlot)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(), MachineType::UintPtr())
-  DECLARE_DESCRIPTOR(TypeConversion_BaselineDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(TypeConversion_BaselineDescriptor)
 };
 
-class SingleParameterOnStackDescriptor final : public CallInterfaceDescriptor {
+class SingleParameterOnStackDescriptor final
+    : public StaticCallInterfaceDescriptor<SingleParameterOnStackDescriptor> {
  public:
   DEFINE_PARAMETERS(kArgument)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged())
-  DECLARE_DESCRIPTOR(SingleParameterOnStackDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(SingleParameterOnStackDescriptor)
+
+  static constexpr auto registers();
 };
 
 class AsyncFunctionStackParameterDescriptor final
-    : public CallInterfaceDescriptor {
+    : public StaticCallInterfaceDescriptor<
+          AsyncFunctionStackParameterDescriptor> {
  public:
   DEFINE_PARAMETERS(kPromise, kResult)
   DEFINE_PARAMETER_TYPES(MachineType::TaggedPointer(), MachineType::AnyTagged())
-  DECLARE_DESCRIPTOR(AsyncFunctionStackParameterDescriptor,
-                     CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(AsyncFunctionStackParameterDescriptor)
+
+  static constexpr auto registers();
 };
 
 class GetIteratorStackParameterDescriptor final
-    : public CallInterfaceDescriptor {
+    : public StaticCallInterfaceDescriptor<
+          GetIteratorStackParameterDescriptor> {
  public:
   DEFINE_PARAMETERS(kReceiver, kCallSlot, kFeedback, kResult)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(), MachineType::AnyTagged(),
                          MachineType::AnyTagged(), MachineType::AnyTagged())
-  DECLARE_DESCRIPTOR(GetIteratorStackParameterDescriptor,
-                     CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(GetIteratorStackParameterDescriptor)
+
+  static constexpr auto registers();
 };
 
-class GetPropertyDescriptor final : public CallInterfaceDescriptor {
+class GetPropertyDescriptor final
+    : public StaticCallInterfaceDescriptor<GetPropertyDescriptor> {
  public:
   DEFINE_PARAMETERS(kObject, kKey)
-  DECLARE_DEFAULT_DESCRIPTOR(GetPropertyDescriptor, CallInterfaceDescriptor)
+  DECLARE_DEFAULT_DESCRIPTOR(GetPropertyDescriptor)
 };
 
-class TypeofDescriptor : public CallInterfaceDescriptor {
+class TypeofDescriptor
+    : public StaticCallInterfaceDescriptor<TypeofDescriptor> {
  public:
   DEFINE_PARAMETERS(kObject)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged())
-  DECLARE_DESCRIPTOR(TypeofDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(TypeofDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class CallTrampolineDescriptor : public CallInterfaceDescriptor {
+class CallTrampolineDescriptor
+    : public StaticCallInterfaceDescriptor<CallTrampolineDescriptor> {
  public:
   DEFINE_PARAMETERS_VARARGS(kFunction, kActualArgumentsCount)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kFunction
                          MachineType::Int32())      // kActualArgumentsCount
-  DECLARE_DESCRIPTOR(CallTrampolineDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(CallTrampolineDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class CallVarargsDescriptor : public CallInterfaceDescriptor {
+class CallVarargsDescriptor
+    : public StaticCallInterfaceDescriptor<CallVarargsDescriptor> {
  public:
   DEFINE_PARAMETERS_VARARGS(kTarget, kActualArgumentsCount, kArgumentsLength,
                             kArgumentsList)
@@ -1113,123 +1121,143 @@ class CallVarargsDescriptor : public CallInterfaceDescriptor {
                          MachineType::Int32(),      // kActualArgumentsCount
                          MachineType::Int32(),      // kArgumentsLength
                          MachineType::AnyTagged())  // kArgumentsList
-  DECLARE_DESCRIPTOR(CallVarargsDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(CallVarargsDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class CallForwardVarargsDescriptor : public CallInterfaceDescriptor {
+class CallForwardVarargsDescriptor
+    : public StaticCallInterfaceDescriptor<CallForwardVarargsDescriptor> {
  public:
   DEFINE_PARAMETERS_VARARGS(kTarget, kActualArgumentsCount, kStartIndex)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kTarget
                          MachineType::Int32(),      // kActualArgumentsCount
                          MachineType::Int32())      // kStartIndex
-  DECLARE_DESCRIPTOR(CallForwardVarargsDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(CallForwardVarargsDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class CallFunctionTemplateDescriptor : public CallInterfaceDescriptor {
+class CallFunctionTemplateDescriptor
+    : public StaticCallInterfaceDescriptor<CallFunctionTemplateDescriptor> {
  public:
   DEFINE_PARAMETERS_VARARGS(kFunctionTemplateInfo, kArgumentsCount)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kFunctionTemplateInfo
                          MachineType::IntPtr())     // kArgumentsCount
-  DECLARE_DESCRIPTOR(CallFunctionTemplateDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(CallFunctionTemplateDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class CallWithSpreadDescriptor : public CallInterfaceDescriptor {
+class CallWithSpreadDescriptor
+    : public StaticCallInterfaceDescriptor<CallWithSpreadDescriptor> {
  public:
   DEFINE_PARAMETERS_VARARGS(kTarget, kArgumentsCount, kSpread)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kTarget
                          MachineType::Int32(),      // kArgumentsCount
                          MachineType::AnyTagged())  // kSpread
-  DECLARE_DESCRIPTOR(CallWithSpreadDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(CallWithSpreadDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class CallWithSpread_BaselineDescriptor : public CallInterfaceDescriptor {
+class CallWithSpread_BaselineDescriptor
+    : public StaticCallInterfaceDescriptor<CallWithSpread_BaselineDescriptor> {
  public:
-  DEFINE_PARAMETERS_VARARGS(kTarget, kArgumentsCount, kSpread, kSlot)
+  DEFINE_PARAMETERS_NO_CONTEXT_VARARGS(kTarget, kArgumentsCount, kSpread, kSlot)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kTarget
                          MachineType::Int32(),      // kArgumentsCount
                          MachineType::AnyTagged(),  // kSpread
                          MachineType::UintPtr())    // kSlot
-  DECLARE_DESCRIPTOR(CallWithSpread_BaselineDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(CallWithSpread_BaselineDescriptor)
 };
 
-class CallWithSpread_WithFeedbackDescriptor : public CallInterfaceDescriptor {
+class CallWithSpread_WithFeedbackDescriptor
+    : public StaticCallInterfaceDescriptor<
+          CallWithSpread_WithFeedbackDescriptor> {
  public:
   DEFINE_PARAMETERS_VARARGS(kTarget, kArgumentsCount, kSpread, kSlot,
-                            kFeedbackVector)
+                            kFeedbackVector, kReceiver)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kTarget
                          MachineType::Int32(),      // kArgumentsCount
                          MachineType::AnyTagged(),  // kSpread
                          MachineType::UintPtr(),    // kSlot
-                         MachineType::AnyTagged())  // kFeedbackVector
-  DECLARE_DESCRIPTOR(CallWithSpread_WithFeedbackDescriptor,
-                     CallInterfaceDescriptor)
+                         MachineType::AnyTagged(),  // kFeedbackVector
+                         MachineType::AnyTagged())  // kReceiver
+  DECLARE_DESCRIPTOR(CallWithSpread_WithFeedbackDescriptor)
 };
 
-class CallWithArrayLikeDescriptor : public CallInterfaceDescriptor {
+class CallWithArrayLikeDescriptor
+    : public StaticCallInterfaceDescriptor<CallWithArrayLikeDescriptor> {
  public:
   DEFINE_PARAMETERS(kTarget, kArgumentsList)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kTarget
                          MachineType::AnyTagged())  // kArgumentsList
-  DECLARE_DESCRIPTOR(CallWithArrayLikeDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(CallWithArrayLikeDescriptor)
+
+  static constexpr inline auto registers();
 };
 
 class CallWithArrayLike_WithFeedbackDescriptor
-    : public CallInterfaceDescriptor {
+    : public StaticCallInterfaceDescriptor<
+          CallWithArrayLike_WithFeedbackDescriptor> {
  public:
-  DEFINE_PARAMETERS(kTarget, kArgumentsList, kSlot, kFeedbackVector)
+  DEFINE_PARAMETERS(kTarget, kArgumentsList, kSlot, kFeedbackVector, kReceiver)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kTarget
                          MachineType::AnyTagged(),  // kArgumentsList
                          MachineType::UintPtr(),    // kSlot
-                         MachineType::AnyTagged())  // kFeedbackVector
-  DECLARE_DESCRIPTOR(CallWithArrayLike_WithFeedbackDescriptor,
-                     CallInterfaceDescriptor)
+                         MachineType::AnyTagged(),  // kFeedbackVector
+                         MachineType::AnyTagged())  // kReceiver
+  DECLARE_DESCRIPTOR(CallWithArrayLike_WithFeedbackDescriptor)
 };
 
-class ConstructVarargsDescriptor : public CallInterfaceDescriptor {
+class ConstructVarargsDescriptor
+    : public StaticCallInterfaceDescriptor<ConstructVarargsDescriptor> {
  public:
   DEFINE_JS_PARAMETERS(kArgumentsLength, kArgumentsList)
   DEFINE_JS_PARAMETER_TYPES(MachineType::Int32(),      // kArgumentsLength
                             MachineType::AnyTagged())  // kArgumentsList
 
-  DECLARE_DESCRIPTOR(ConstructVarargsDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(ConstructVarargsDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class ConstructForwardVarargsDescriptor : public CallInterfaceDescriptor {
+class ConstructForwardVarargsDescriptor
+    : public StaticCallInterfaceDescriptor<ConstructForwardVarargsDescriptor> {
  public:
   DEFINE_JS_PARAMETERS(kStartIndex)
   DEFINE_JS_PARAMETER_TYPES(MachineType::Int32())
-  DECLARE_DESCRIPTOR(ConstructForwardVarargsDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(ConstructForwardVarargsDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class ConstructWithSpreadDescriptor : public CallInterfaceDescriptor {
+class ConstructWithSpreadDescriptor
+    : public StaticCallInterfaceDescriptor<ConstructWithSpreadDescriptor> {
  public:
   DEFINE_JS_PARAMETERS(kSpread)
   DEFINE_JS_PARAMETER_TYPES(MachineType::AnyTagged())
-  DECLARE_DESCRIPTOR(ConstructWithSpreadDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(ConstructWithSpreadDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class ConstructWithSpread_BaselineDescriptor : public CallInterfaceDescriptor {
+class ConstructWithSpread_BaselineDescriptor
+    : public StaticCallInterfaceDescriptor<
+          ConstructWithSpread_BaselineDescriptor> {
  public:
   // Note: kSlot comes before kSpread since as an untagged value it must be
   // passed in a register.
-  DEFINE_JS_PARAMETERS(kSlot, kSpread)
+  DEFINE_JS_PARAMETERS_NO_CONTEXT(kSlot, kSpread)
   DEFINE_JS_PARAMETER_TYPES(MachineType::UintPtr(),    // kSlot
                             MachineType::AnyTagged())  // kSpread
-  DECLARE_DESCRIPTOR(ConstructWithSpread_BaselineDescriptor,
-                     CallInterfaceDescriptor)
-
-#if V8_TARGET_ARCH_IA32
-  static const bool kPassLastArgsOnStack = true;
-#else
-  static const bool kPassLastArgsOnStack = false;
-#endif
-
-  // Pass spread through the stack.
-  static const int kStackArgumentsCount = kPassLastArgsOnStack ? 1 : 0;
+  DECLARE_DESCRIPTOR(ConstructWithSpread_BaselineDescriptor)
 };
 
 class ConstructWithSpread_WithFeedbackDescriptor
-    : public CallInterfaceDescriptor {
+    : public StaticCallInterfaceDescriptor<
+          ConstructWithSpread_WithFeedbackDescriptor> {
  public:
   // Note: kSlot comes before kSpread since as an untagged value it must be
   // passed in a register.
@@ -1237,21 +1265,24 @@ class ConstructWithSpread_WithFeedbackDescriptor
   DEFINE_JS_PARAMETER_TYPES(MachineType::UintPtr(),    // kSlot
                             MachineType::AnyTagged(),  // kSpread
                             MachineType::AnyTagged())  // kFeedbackVector
-  DECLARE_DESCRIPTOR(ConstructWithSpread_WithFeedbackDescriptor,
-                     CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(ConstructWithSpread_WithFeedbackDescriptor)
 };
 
-class ConstructWithArrayLikeDescriptor : public CallInterfaceDescriptor {
+class ConstructWithArrayLikeDescriptor
+    : public StaticCallInterfaceDescriptor<ConstructWithArrayLikeDescriptor> {
  public:
   DEFINE_PARAMETERS(kTarget, kNewTarget, kArgumentsList)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kTarget
                          MachineType::AnyTagged(),  // kNewTarget
                          MachineType::AnyTagged())  // kArgumentsList
-  DECLARE_DESCRIPTOR(ConstructWithArrayLikeDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(ConstructWithArrayLikeDescriptor)
+
+  static constexpr inline auto registers();
 };
 
 class ConstructWithArrayLike_WithFeedbackDescriptor
-    : public CallInterfaceDescriptor {
+    : public StaticCallInterfaceDescriptor<
+          ConstructWithArrayLike_WithFeedbackDescriptor> {
  public:
   DEFINE_PARAMETERS(kTarget, kNewTarget, kArgumentsList, kSlot, kFeedbackVector)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kTarget
@@ -1259,38 +1290,44 @@ class ConstructWithArrayLike_WithFeedbackDescriptor
                          MachineType::AnyTagged(),  // kArgumentsList
                          MachineType::UintPtr(),    // kSlot
                          MachineType::AnyTagged())  // kFeedbackVector
-  DECLARE_DESCRIPTOR(ConstructWithArrayLike_WithFeedbackDescriptor,
-                     CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(ConstructWithArrayLike_WithFeedbackDescriptor)
 };
 
 // TODO(ishell): consider merging this with ArrayConstructorDescriptor
-class ConstructStubDescriptor : public CallInterfaceDescriptor {
+class ConstructStubDescriptor
+    : public StaticCallInterfaceDescriptor<ConstructStubDescriptor> {
  public:
   // TODO(jgruber): Remove the unused allocation site parameter.
   DEFINE_JS_PARAMETERS(kAllocationSite)
   DEFINE_JS_PARAMETER_TYPES(MachineType::AnyTagged())
 
   // TODO(ishell): Use DECLARE_JS_COMPATIBLE_DESCRIPTOR if registers match
-  DECLARE_DESCRIPTOR(ConstructStubDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(ConstructStubDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class AbortDescriptor : public CallInterfaceDescriptor {
+class AbortDescriptor : public StaticCallInterfaceDescriptor<AbortDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kMessageOrMessageId)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged())
-  DECLARE_DESCRIPTOR(AbortDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(AbortDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class ArrayConstructorDescriptor : public CallInterfaceDescriptor {
+class ArrayConstructorDescriptor
+    : public StaticJSCallInterfaceDescriptor<ArrayConstructorDescriptor> {
  public:
   DEFINE_JS_PARAMETERS(kAllocationSite)
   DEFINE_JS_PARAMETER_TYPES(MachineType::AnyTagged())
 
-  DECLARE_JS_COMPATIBLE_DESCRIPTOR(ArrayConstructorDescriptor,
-                                   CallInterfaceDescriptor, 1)
+  DECLARE_JS_COMPATIBLE_DESCRIPTOR(ArrayConstructorDescriptor)
 };
 
-class ArrayNArgumentsConstructorDescriptor : public CallInterfaceDescriptor {
+class ArrayNArgumentsConstructorDescriptor
+    : public StaticCallInterfaceDescriptor<
+          ArrayNArgumentsConstructorDescriptor> {
  public:
   // This descriptor declares only register arguments while respective number
   // of JS arguments stay on the expression stack.
@@ -1300,12 +1337,14 @@ class ArrayNArgumentsConstructorDescriptor : public CallInterfaceDescriptor {
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kFunction,
                          MachineType::AnyTagged(),  // kAllocationSite
                          MachineType::Int32())      // kActualArgumentsCount
-  DECLARE_DESCRIPTOR(ArrayNArgumentsConstructorDescriptor,
-                     CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(ArrayNArgumentsConstructorDescriptor)
+
+  static constexpr auto registers();
 };
 
 class ArrayNoArgumentConstructorDescriptor
-    : public ArrayNArgumentsConstructorDescriptor {
+    : public StaticCallInterfaceDescriptor<
+          ArrayNoArgumentConstructorDescriptor> {
  public:
   // This descriptor declares same register arguments as the parent
   // ArrayNArgumentsConstructorDescriptor and it declares indices for
@@ -1316,12 +1355,14 @@ class ArrayNoArgumentConstructorDescriptor
                          MachineType::AnyTagged(),  // kAllocationSite
                          MachineType::Int32(),      // kActualArgumentsCount
                          MachineType::AnyTagged())  // kFunctionParameter
-  DECLARE_DESCRIPTOR(ArrayNoArgumentConstructorDescriptor,
-                     ArrayNArgumentsConstructorDescriptor)
+  DECLARE_DESCRIPTOR(ArrayNoArgumentConstructorDescriptor)
+
+  static constexpr auto registers();
 };
 
 class ArraySingleArgumentConstructorDescriptor
-    : public ArrayNArgumentsConstructorDescriptor {
+    : public StaticCallInterfaceDescriptor<
+          ArraySingleArgumentConstructorDescriptor> {
  public:
   // This descriptor declares same register arguments as the parent
   // ArrayNArgumentsConstructorDescriptor and it declares indices for
@@ -1334,44 +1375,56 @@ class ArraySingleArgumentConstructorDescriptor
                          // JS arguments on the stack
                          MachineType::AnyTagged(),  // kArraySizeSmiParameter
                          MachineType::AnyTagged())  // kReceiverParameter
-  DECLARE_DESCRIPTOR(ArraySingleArgumentConstructorDescriptor,
-                     ArrayNArgumentsConstructorDescriptor)
+  DECLARE_DESCRIPTOR(ArraySingleArgumentConstructorDescriptor)
+
+  static constexpr auto registers();
 };
 
-class CompareDescriptor : public CallInterfaceDescriptor {
+class CompareDescriptor
+    : public StaticCallInterfaceDescriptor<CompareDescriptor> {
  public:
   DEFINE_PARAMETERS(kLeft, kRight)
-  DECLARE_DESCRIPTOR(CompareDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(CompareDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class BinaryOpDescriptor : public CallInterfaceDescriptor {
+class BinaryOpDescriptor
+    : public StaticCallInterfaceDescriptor<BinaryOpDescriptor> {
  public:
   DEFINE_PARAMETERS(kLeft, kRight)
-  DECLARE_DESCRIPTOR(BinaryOpDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(BinaryOpDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class BinaryOp_BaselineDescriptor : public CallInterfaceDescriptor {
+class BinaryOp_BaselineDescriptor
+    : public StaticCallInterfaceDescriptor<BinaryOp_BaselineDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kLeft, kRight, kSlot)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kLeft
                          MachineType::AnyTagged(),  // kRight
                          MachineType::UintPtr())    // kSlot
-  DECLARE_DESCRIPTOR(BinaryOp_BaselineDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(BinaryOp_BaselineDescriptor)
+
+  static constexpr inline auto registers();
 };
 
 // This desciptor is shared among String.p.charAt/charCodeAt/codePointAt
 // as they all have the same interface.
-class StringAtDescriptor final : public CallInterfaceDescriptor {
+class StringAtDescriptor final
+    : public StaticCallInterfaceDescriptor<StringAtDescriptor> {
  public:
   DEFINE_PARAMETERS(kReceiver, kPosition)
   // TODO(turbofan): Return untagged value here.
   DEFINE_RESULT_AND_PARAMETER_TYPES(MachineType::TaggedSigned(),  // result 1
                                     MachineType::AnyTagged(),     // kReceiver
                                     MachineType::IntPtr())        // kPosition
-  DECLARE_DESCRIPTOR(StringAtDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(StringAtDescriptor)
 };
 
-class StringAtAsStringDescriptor final : public CallInterfaceDescriptor {
+class StringAtAsStringDescriptor final
+    : public StaticCallInterfaceDescriptor<StringAtAsStringDescriptor> {
  public:
   DEFINE_PARAMETERS(kReceiver, kPosition)
   // TODO(turbofan): Return untagged value here.
@@ -1379,10 +1432,11 @@ class StringAtAsStringDescriptor final : public CallInterfaceDescriptor {
       MachineType::TaggedPointer(),  // result string
       MachineType::AnyTagged(),      // kReceiver
       MachineType::IntPtr())         // kPosition
-  DECLARE_DESCRIPTOR(StringAtAsStringDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(StringAtAsStringDescriptor)
 };
 
-class StringSubstringDescriptor final : public CallInterfaceDescriptor {
+class StringSubstringDescriptor final
+    : public StaticCallInterfaceDescriptor<StringSubstringDescriptor> {
  public:
   DEFINE_PARAMETERS(kString, kFrom, kTo)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kString
@@ -1390,18 +1444,19 @@ class StringSubstringDescriptor final : public CallInterfaceDescriptor {
                          MachineType::IntPtr())     // kTo
 
   // TODO(turbofan): Allow builtins to return untagged values.
-  DECLARE_DESCRIPTOR(StringSubstringDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(StringSubstringDescriptor)
 };
 
-class CppBuiltinAdaptorDescriptor : public CallInterfaceDescriptor {
+class CppBuiltinAdaptorDescriptor
+    : public StaticJSCallInterfaceDescriptor<CppBuiltinAdaptorDescriptor> {
  public:
   DEFINE_JS_PARAMETERS(kCFunction)
   DEFINE_JS_PARAMETER_TYPES(MachineType::Pointer())
-  DECLARE_JS_COMPATIBLE_DESCRIPTOR(CppBuiltinAdaptorDescriptor,
-                                   CallInterfaceDescriptor, 1)
+  DECLARE_JS_COMPATIBLE_DESCRIPTOR(CppBuiltinAdaptorDescriptor)
 };
 
-class CEntry1ArgvOnStackDescriptor : public CallInterfaceDescriptor {
+class CEntry1ArgvOnStackDescriptor
+    : public StaticCallInterfaceDescriptor<CEntry1ArgvOnStackDescriptor> {
  public:
   DEFINE_PARAMETERS(kArity,          // register argument
                     kCFunction,      // register argument
@@ -1415,10 +1470,13 @@ class CEntry1ArgvOnStackDescriptor : public CallInterfaceDescriptor {
                          MachineType::AnyTagged(),  // kArgcSmi
                          MachineType::AnyTagged(),  // kTargetCopy
                          MachineType::AnyTagged())  // kNewTargetCopy
-  DECLARE_DESCRIPTOR(CEntry1ArgvOnStackDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(CEntry1ArgvOnStackDescriptor)
+
+  static constexpr auto registers();
 };
 
-class ApiCallbackDescriptor : public CallInterfaceDescriptor {
+class ApiCallbackDescriptor
+    : public StaticCallInterfaceDescriptor<ApiCallbackDescriptor> {
  public:
   DEFINE_PARAMETERS_VARARGS(kApiFunctionAddress, kActualArgumentsCount,
                             kCallData, kHolder)
@@ -1428,44 +1486,56 @@ class ApiCallbackDescriptor : public CallInterfaceDescriptor {
                          MachineType::IntPtr(),     // kActualArgumentsCount
                          MachineType::AnyTagged(),  // kCallData
                          MachineType::AnyTagged())  // kHolder
-  DECLARE_DESCRIPTOR(ApiCallbackDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(ApiCallbackDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class ApiGetterDescriptor : public CallInterfaceDescriptor {
+class ApiGetterDescriptor
+    : public StaticCallInterfaceDescriptor<ApiGetterDescriptor> {
  public:
   DEFINE_PARAMETERS(kReceiver, kHolder, kCallback)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kReceiver
                          MachineType::AnyTagged(),  // kHolder
                          MachineType::AnyTagged())  // kCallback
-  DECLARE_DESCRIPTOR(ApiGetterDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(ApiGetterDescriptor)
 
-  static const Register ReceiverRegister();
-  static const Register HolderRegister();
-  static const Register CallbackRegister();
+  static constexpr inline Register ReceiverRegister();
+  static constexpr inline Register HolderRegister();
+  static constexpr inline Register CallbackRegister();
+
+  static constexpr auto registers();
 };
 
 // TODO(turbofan): We should probably rename this to GrowFastElementsDescriptor.
-class GrowArrayElementsDescriptor : public CallInterfaceDescriptor {
+class GrowArrayElementsDescriptor
+    : public StaticCallInterfaceDescriptor<GrowArrayElementsDescriptor> {
  public:
   DEFINE_PARAMETERS(kObject, kKey)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kObject
                          MachineType::AnyTagged())  // kKey
-  DECLARE_DESCRIPTOR(GrowArrayElementsDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(GrowArrayElementsDescriptor)
+
+  static constexpr inline Register ObjectRegister();
+  static constexpr inline Register KeyRegister();
 
-  static const Register ObjectRegister();
-  static const Register KeyRegister();
+  static constexpr auto registers();
 };
 
 class V8_EXPORT_PRIVATE TailCallOptimizedCodeSlotDescriptor
-    : public CallInterfaceDescriptor {
+    : public StaticCallInterfaceDescriptor<
+          TailCallOptimizedCodeSlotDescriptor> {
  public:
   DEFINE_PARAMETERS(kOptimizedCodeEntry)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged())  // kAccumulator
-  DECLARE_DESCRIPTOR(TailCallOptimizedCodeSlotDescriptor,
-                     CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(TailCallOptimizedCodeSlotDescriptor)
+
+  static constexpr auto registers();
 };
 
-class BaselineOutOfLinePrologueDescriptor : public CallInterfaceDescriptor {
+class BaselineOutOfLinePrologueDescriptor
+    : public StaticCallInterfaceDescriptor<
+          BaselineOutOfLinePrologueDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kCalleeContext, kClosure,
                                kJavaScriptCallArgCount, kStackFrameSize,
@@ -1477,32 +1547,31 @@ class BaselineOutOfLinePrologueDescriptor : public CallInterfaceDescriptor {
                          MachineType::Int32(),      // kStackFrameSize
                          MachineType::AnyTagged(),  // kJavaScriptCallNewTarget
                          MachineType::AnyTagged())  // kInterpreterBytecodeArray
-  DECLARE_DESCRIPTOR(BaselineOutOfLinePrologueDescriptor,
-                     CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(BaselineOutOfLinePrologueDescriptor)
 
-#if V8_TARGET_ARCH_IA32
-  static const bool kPassLastArgsOnStack = true;
-#else
-  static const bool kPassLastArgsOnStack = false;
-#endif
+  static constexpr inline auto registers();
 
-  // Pass bytecode array through the stack.
-  static const int kStackArgumentsCount = kPassLastArgsOnStack ? 1 : 0;
+  // We pass the context manually, so we have one extra register.
+  static constexpr int kMaxRegisterParams =
+      StaticCallInterfaceDescriptor::kMaxRegisterParams + 1;
 };
 
-class BaselineLeaveFrameDescriptor : public CallInterfaceDescriptor {
+class BaselineLeaveFrameDescriptor
+    : public StaticCallInterfaceDescriptor<BaselineLeaveFrameDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kParamsSize, kWeight)
   DEFINE_PARAMETER_TYPES(MachineType::Int32(),  // kParamsSize
                          MachineType::Int32())  // kWeight
-  DECLARE_DESCRIPTOR(BaselineLeaveFrameDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(BaselineLeaveFrameDescriptor)
+
+  static constexpr inline Register ParamsSizeRegister();
+  static constexpr inline Register WeightRegister();
 
-  static const Register ParamsSizeRegister();
-  static const Register WeightRegister();
+  static constexpr inline auto registers();
 };
 
 class V8_EXPORT_PRIVATE InterpreterDispatchDescriptor
-    : public CallInterfaceDescriptor {
+    : public StaticCallInterfaceDescriptor<InterpreterDispatchDescriptor> {
  public:
   DEFINE_PARAMETERS(kAccumulator, kBytecodeOffset, kBytecodeArray,
                     kDispatchTable)
@@ -1510,21 +1579,27 @@ class V8_EXPORT_PRIVATE InterpreterDispatchDescriptor
                          MachineType::IntPtr(),     // kBytecodeOffset
                          MachineType::AnyTagged(),  // kBytecodeArray
                          MachineType::IntPtr())     // kDispatchTable
-  DECLARE_DESCRIPTOR(InterpreterDispatchDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(InterpreterDispatchDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class InterpreterPushArgsThenCallDescriptor : public CallInterfaceDescriptor {
+class InterpreterPushArgsThenCallDescriptor
+    : public StaticCallInterfaceDescriptor<
+          InterpreterPushArgsThenCallDescriptor> {
  public:
   DEFINE_PARAMETERS(kNumberOfArguments, kFirstArgument, kFunction)
   DEFINE_PARAMETER_TYPES(MachineType::Int32(),      // kNumberOfArguments
                          MachineType::Pointer(),    // kFirstArgument
                          MachineType::AnyTagged())  // kFunction
-  DECLARE_DESCRIPTOR(InterpreterPushArgsThenCallDescriptor,
-                     CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(InterpreterPushArgsThenCallDescriptor)
+
+  static constexpr inline auto registers();
 };
 
 class InterpreterPushArgsThenConstructDescriptor
-    : public CallInterfaceDescriptor {
+    : public StaticCallInterfaceDescriptor<
+          InterpreterPushArgsThenConstructDescriptor> {
  public:
   DEFINE_PARAMETERS(kNumberOfArguments, kFirstArgument, kConstructor,
                     kNewTarget, kFeedbackElement)
@@ -1533,20 +1608,13 @@ class InterpreterPushArgsThenConstructDescriptor
                          MachineType::AnyTagged(),  // kConstructor
                          MachineType::AnyTagged(),  // kNewTarget
                          MachineType::AnyTagged())  // kFeedbackElement
-  DECLARE_DESCRIPTOR(InterpreterPushArgsThenConstructDescriptor,
-                     CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(InterpreterPushArgsThenConstructDescriptor)
 
-#if V8_TARGET_ARCH_IA32
-  static const bool kPassLastArgsOnStack = true;
-#else
-  static const bool kPassLastArgsOnStack = false;
-#endif
-
-  // Pass constructor, new target and feedback element through the stack.
-  static const int kStackArgumentsCount = kPassLastArgsOnStack ? 3 : 0;
+  static constexpr inline auto registers();
 };
 
-class InterpreterCEntry1Descriptor : public CallInterfaceDescriptor {
+class InterpreterCEntry1Descriptor
+    : public StaticCallInterfaceDescriptor<InterpreterCEntry1Descriptor> {
  public:
   DEFINE_RESULT_AND_PARAMETERS(1, kNumberOfArguments, kFirstArgument,
                                kFunctionEntry)
@@ -1554,10 +1622,13 @@ class InterpreterCEntry1Descriptor : public CallInterfaceDescriptor {
                                     MachineType::Int32(),  // kNumberOfArguments
                                     MachineType::Pointer(),  // kFirstArgument
                                     MachineType::Pointer())  // kFunctionEntry
-  DECLARE_DESCRIPTOR(InterpreterCEntry1Descriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(InterpreterCEntry1Descriptor)
+
+  static constexpr auto registers();
 };
 
-class InterpreterCEntry2Descriptor : public CallInterfaceDescriptor {
+class InterpreterCEntry2Descriptor
+    : public StaticCallInterfaceDescriptor<InterpreterCEntry2Descriptor> {
  public:
   DEFINE_RESULT_AND_PARAMETERS(2, kNumberOfArguments, kFirstArgument,
                                kFunctionEntry)
@@ -1566,10 +1637,13 @@ class InterpreterCEntry2Descriptor : public CallInterfaceDescriptor {
                                     MachineType::Int32(),  // kNumberOfArguments
                                     MachineType::Pointer(),  // kFirstArgument
                                     MachineType::Pointer())  // kFunctionEntry
-  DECLARE_DESCRIPTOR(InterpreterCEntry2Descriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(InterpreterCEntry2Descriptor)
+
+  static constexpr auto registers();
 };
 
-class ForInPrepareDescriptor : public CallInterfaceDescriptor {
+class ForInPrepareDescriptor
+    : public StaticCallInterfaceDescriptor<ForInPrepareDescriptor> {
  public:
   DEFINE_RESULT_AND_PARAMETERS(2, kEnumerator, kVectorIndex, kFeedbackVector)
   DEFINE_RESULT_AND_PARAMETER_TYPES(
@@ -1578,120 +1652,133 @@ class ForInPrepareDescriptor : public CallInterfaceDescriptor {
       MachineType::AnyTagged(),     // kEnumerator
       MachineType::TaggedSigned(),  // kVectorIndex
       MachineType::AnyTagged())     // kFeedbackVector
-  DECLARE_DESCRIPTOR(ForInPrepareDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(ForInPrepareDescriptor)
 };
 
-class ResumeGeneratorDescriptor final : public CallInterfaceDescriptor {
+class ResumeGeneratorDescriptor final
+    : public StaticCallInterfaceDescriptor<ResumeGeneratorDescriptor> {
  public:
   DEFINE_PARAMETERS(kValue, kGenerator)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kValue
                          MachineType::AnyTagged())  // kGenerator
-  DECLARE_DESCRIPTOR(ResumeGeneratorDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(ResumeGeneratorDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class ResumeGeneratorBaselineDescriptor final : public CallInterfaceDescriptor {
+class ResumeGeneratorBaselineDescriptor final
+    : public StaticCallInterfaceDescriptor<ResumeGeneratorBaselineDescriptor> {
  public:
-  DEFINE_PARAMETERS(kGeneratorObject, kRegisterCount)
+  DEFINE_PARAMETERS_NO_CONTEXT(kGeneratorObject, kRegisterCount)
   DEFINE_RESULT_AND_PARAMETER_TYPES(
       MachineType::TaggedSigned(),  // return type
       MachineType::AnyTagged(),     // kGeneratorObject
       MachineType::IntPtr(),        // kRegisterCount
   )
-  DECLARE_DESCRIPTOR(ResumeGeneratorBaselineDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(ResumeGeneratorBaselineDescriptor)
 };
 
 class SuspendGeneratorBaselineDescriptor final
-    : public CallInterfaceDescriptor {
+    : public StaticCallInterfaceDescriptor<SuspendGeneratorBaselineDescriptor> {
  public:
-  DEFINE_PARAMETERS(kGeneratorObject, kSuspendId, kBytecodeOffset,
-                    kRegisterCount)
+  DEFINE_PARAMETERS_NO_CONTEXT(kGeneratorObject, kSuspendId, kBytecodeOffset,
+                               kRegisterCount)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kGeneratorObject
                          MachineType::IntPtr(),     // kSuspendId
                          MachineType::IntPtr(),     // kBytecodeOffset
                          MachineType::IntPtr(),     // kRegisterCount
   )
-  DECLARE_DESCRIPTOR(SuspendGeneratorBaselineDescriptor,
-                     CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(SuspendGeneratorBaselineDescriptor)
 };
 
-class FrameDropperTrampolineDescriptor final : public CallInterfaceDescriptor {
- public:
-  DEFINE_PARAMETERS(kRestartFp)
-  DEFINE_PARAMETER_TYPES(MachineType::Pointer())
-  DECLARE_DESCRIPTOR(FrameDropperTrampolineDescriptor, CallInterfaceDescriptor)
-};
-
-class RunMicrotasksEntryDescriptor final : public CallInterfaceDescriptor {
+class RunMicrotasksEntryDescriptor final
+    : public StaticCallInterfaceDescriptor<RunMicrotasksEntryDescriptor> {
  public:
   DEFINE_PARAMETERS_ENTRY(kRootRegisterValue, kMicrotaskQueue)
   DEFINE_PARAMETER_TYPES(MachineType::Pointer(),  // kRootRegisterValue
                          MachineType::Pointer())  // kMicrotaskQueue
-  DECLARE_DESCRIPTOR(RunMicrotasksEntryDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(RunMicrotasksEntryDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class RunMicrotasksDescriptor final : public CallInterfaceDescriptor {
+class RunMicrotasksDescriptor final
+    : public StaticCallInterfaceDescriptor<RunMicrotasksDescriptor> {
  public:
   DEFINE_PARAMETERS(kMicrotaskQueue)
   DEFINE_PARAMETER_TYPES(MachineType::Pointer())
-  DECLARE_DESCRIPTOR(RunMicrotasksDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(RunMicrotasksDescriptor)
 
-  static Register MicrotaskQueueRegister();
+  static constexpr inline Register MicrotaskQueueRegister();
 };
 
-class WasmFloat32ToNumberDescriptor final : public CallInterfaceDescriptor {
+class WasmFloat32ToNumberDescriptor final
+    : public StaticCallInterfaceDescriptor<WasmFloat32ToNumberDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kValue)
   DEFINE_RESULT_AND_PARAMETER_TYPES(MachineType::AnyTagged(),  // result
                                     MachineType::Float32())    // value
-  DECLARE_DESCRIPTOR(WasmFloat32ToNumberDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(WasmFloat32ToNumberDescriptor)
+
+#if V8_TARGET_ARCH_IA32
+  // We need a custom descriptor on ia32 to avoid using xmm0.
+  static constexpr inline auto registers();
+#endif
 };
 
-class WasmFloat64ToNumberDescriptor final : public CallInterfaceDescriptor {
+class WasmFloat64ToNumberDescriptor final
+    : public StaticCallInterfaceDescriptor<WasmFloat64ToNumberDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kValue)
   DEFINE_RESULT_AND_PARAMETER_TYPES(MachineType::AnyTagged(),  // result
                                     MachineType::Float64())    // value
-  DECLARE_DESCRIPTOR(WasmFloat64ToNumberDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(WasmFloat64ToNumberDescriptor)
+
+#if V8_TARGET_ARCH_IA32
+  // We need a custom descriptor on ia32 to avoid using xmm0.
+  static constexpr inline auto registers();
+#endif
 };
 
 class V8_EXPORT_PRIVATE I64ToBigIntDescriptor final
-    : public CallInterfaceDescriptor {
+    : public StaticCallInterfaceDescriptor<I64ToBigIntDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kArgument)
   DEFINE_PARAMETER_TYPES(MachineType::Int64())  // kArgument
-  DECLARE_DESCRIPTOR(I64ToBigIntDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(I64ToBigIntDescriptor)
 };
 
 // 32 bits version of the I64ToBigIntDescriptor call interface descriptor
 class V8_EXPORT_PRIVATE I32PairToBigIntDescriptor final
-    : public CallInterfaceDescriptor {
+    : public StaticCallInterfaceDescriptor<I32PairToBigIntDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kLow, kHigh)
   DEFINE_PARAMETER_TYPES(MachineType::Uint32(),  // kLow
                          MachineType::Uint32())  // kHigh
-  DECLARE_DESCRIPTOR(I32PairToBigIntDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(I32PairToBigIntDescriptor)
 };
 
 class V8_EXPORT_PRIVATE BigIntToI64Descriptor final
-    : public CallInterfaceDescriptor {
+    : public StaticCallInterfaceDescriptor<BigIntToI64Descriptor> {
  public:
   DEFINE_PARAMETERS(kArgument)
   DEFINE_RESULT_AND_PARAMETER_TYPES(MachineType::Int64(),      // result 1
                                     MachineType::AnyTagged())  // kArgument
-  DECLARE_DESCRIPTOR(BigIntToI64Descriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(BigIntToI64Descriptor)
 };
 
 class V8_EXPORT_PRIVATE BigIntToI32PairDescriptor final
-    : public CallInterfaceDescriptor {
+    : public StaticCallInterfaceDescriptor<BigIntToI32PairDescriptor> {
  public:
   DEFINE_RESULT_AND_PARAMETERS(2, kArgument)
   DEFINE_RESULT_AND_PARAMETER_TYPES(MachineType::Uint32(),     // result 1
                                     MachineType::Uint32(),     // result 2
                                     MachineType::AnyTagged())  // kArgument
-  DECLARE_DESCRIPTOR(BigIntToI32PairDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(BigIntToI32PairDescriptor)
 };
 
-class WasmI32AtomicWait32Descriptor final : public CallInterfaceDescriptor {
+class WasmI32AtomicWait32Descriptor final
+    : public StaticCallInterfaceDescriptor<WasmI32AtomicWait32Descriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kAddress, kExpectedValue, kTimeoutLow,
                                kTimeoutHigh)
@@ -1700,36 +1787,30 @@ class WasmI32AtomicWait32Descriptor final : public CallInterfaceDescriptor {
                                     MachineType::Int32(),   // kExpectedValue
                                     MachineType::Uint32(),  // kTimeoutLow
                                     MachineType::Uint32())  // kTimeoutHigh
-  DECLARE_DESCRIPTOR(WasmI32AtomicWait32Descriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(WasmI32AtomicWait32Descriptor)
 };
 
-class WasmI64AtomicWait32Descriptor final : public CallInterfaceDescriptor {
+class WasmI64AtomicWait32Descriptor final
+    : public StaticCallInterfaceDescriptor<WasmI64AtomicWait32Descriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kAddress, kExpectedValueLow, kExpectedValueHigh,
                                kTimeoutLow, kTimeoutHigh)
 
-  DEFINE_RESULT_AND_PARAMETER_TYPES_WITH_FLAG(
-      CallInterfaceDescriptorData::kNoStackScan,  // allow untagged stack params
-      MachineType::Uint32(),                      // result 1
-      MachineType::Uint32(),                      // kAddress
-      MachineType::Uint32(),                      // kExpectedValueLow
-      MachineType::Uint32(),                      // kExpectedValueHigh
-      MachineType::Uint32(),                      // kTimeoutLow
-      MachineType::Uint32())                      // kTimeoutHigh
+  static constexpr bool kNoStackScan = true;
 
-#if V8_TARGET_ARCH_IA32
-  static constexpr bool kPassLastArgOnStack = true;
-#else
-  static constexpr bool kPassLastArgOnStack = false;
-#endif
-
-  // Pass the last parameter through the stack.
-  static constexpr int kStackArgumentsCount = kPassLastArgOnStack ? 1 : 0;
+  DEFINE_RESULT_AND_PARAMETER_TYPES(
+      MachineType::Uint32(),  // result 1
+      MachineType::Uint32(),  // kAddress
+      MachineType::Uint32(),  // kExpectedValueLow
+      MachineType::Uint32(),  // kExpectedValueHigh
+      MachineType::Uint32(),  // kTimeoutLow
+      MachineType::Uint32())  // kTimeoutHigh
 
-  DECLARE_DESCRIPTOR(WasmI64AtomicWait32Descriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(WasmI64AtomicWait32Descriptor)
 };
 
-class CloneObjectWithVectorDescriptor final : public CallInterfaceDescriptor {
+class CloneObjectWithVectorDescriptor final
+    : public StaticCallInterfaceDescriptor<CloneObjectWithVectorDescriptor> {
  public:
   DEFINE_PARAMETERS(kSource, kFlags, kSlot, kVector)
   DEFINE_RESULT_AND_PARAMETER_TYPES(MachineType::TaggedPointer(),  // result 1
@@ -1737,108 +1818,142 @@ class CloneObjectWithVectorDescriptor final : public CallInterfaceDescriptor {
                                     MachineType::TaggedSigned(),   // kFlags
                                     MachineType::TaggedSigned(),   // kSlot
                                     MachineType::AnyTagged())      // kVector
-  DECLARE_DESCRIPTOR(CloneObjectWithVectorDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(CloneObjectWithVectorDescriptor)
 };
 
-class CloneObjectBaselineDescriptor final : public CallInterfaceDescriptor {
+class CloneObjectBaselineDescriptor final
+    : public StaticCallInterfaceDescriptor<CloneObjectBaselineDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kSource, kFlags, kSlot)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),     // kSource
                          MachineType::TaggedSigned(),  // kFlags
                          MachineType::TaggedSigned())  // kSlot
-  DECLARE_DESCRIPTOR(CloneObjectBaselineDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(CloneObjectBaselineDescriptor)
 };
 
-class BinaryOp_WithFeedbackDescriptor : public CallInterfaceDescriptor {
+class BinaryOp_WithFeedbackDescriptor
+    : public StaticCallInterfaceDescriptor<BinaryOp_WithFeedbackDescriptor> {
  public:
   DEFINE_PARAMETERS(kLeft, kRight, kSlot, kFeedbackVector)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kLeft
                          MachineType::AnyTagged(),  // kRight
                          MachineType::UintPtr(),    // kSlot
                          MachineType::AnyTagged())  // kFeedbackVector
-  DECLARE_DESCRIPTOR(BinaryOp_WithFeedbackDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(BinaryOp_WithFeedbackDescriptor)
+};
+
+class CallTrampoline_Baseline_CompactDescriptor
+    : public StaticCallInterfaceDescriptor<
+          CallTrampoline_Baseline_CompactDescriptor> {
+ public:
+  using ArgumentCountField = base::BitField<uint32_t, 0, 8>;
+  using SlotField = base::BitField<uintptr_t, 8, 24>;
+
+  static bool EncodeBitField(uint32_t argc, uintptr_t slot, uint32_t* out) {
+    if (ArgumentCountField::is_valid(argc) && SlotField::is_valid(slot)) {
+      *out = ArgumentCountField::encode(argc) | SlotField::encode(slot);
+      return true;
+    }
+    return false;
+  }
+
+  DEFINE_PARAMETERS_NO_CONTEXT_VARARGS(kFunction, kBitField)
+  DEFINE_PARAMETER_TYPES(
+      MachineType::AnyTagged(),  // kFunction
+      MachineType::Uint32())     // kBitField = ArgumentCountField | SlotField
+  DECLARE_DESCRIPTOR(CallTrampoline_Baseline_CompactDescriptor)
 };
 
-class CallTrampoline_BaselineDescriptor : public CallInterfaceDescriptor {
+class CallTrampoline_BaselineDescriptor
+    : public StaticCallInterfaceDescriptor<CallTrampoline_BaselineDescriptor> {
  public:
-  DEFINE_PARAMETERS_VARARGS(kFunction, kActualArgumentsCount, kSlot)
+  DEFINE_PARAMETERS_NO_CONTEXT_VARARGS(kFunction, kActualArgumentsCount, kSlot)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kFunction
                          MachineType::Int32(),      // kActualArgumentsCount
                          MachineType::UintPtr())    // kSlot
-  DECLARE_DESCRIPTOR(CallTrampoline_BaselineDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(CallTrampoline_BaselineDescriptor)
 };
 
-class CallTrampoline_WithFeedbackDescriptor : public CallInterfaceDescriptor {
+class CallTrampoline_WithFeedbackDescriptor
+    : public StaticCallInterfaceDescriptor<
+          CallTrampoline_WithFeedbackDescriptor> {
  public:
   DEFINE_PARAMETERS_VARARGS(kFunction, kActualArgumentsCount, kSlot,
-                            kFeedbackVector)
+                            kFeedbackVector, kReceiver)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kFunction
                          MachineType::Int32(),      // kActualArgumentsCount
                          MachineType::UintPtr(),    // kSlot
-                         MachineType::AnyTagged())  // kFeedbackVector
-  DECLARE_DESCRIPTOR(CallTrampoline_WithFeedbackDescriptor,
-                     CallInterfaceDescriptor)
+                         MachineType::AnyTagged(),  // kFeedbackVector
+                         MachineType::AnyTagged())  // kReceiver
+  DECLARE_DESCRIPTOR(CallTrampoline_WithFeedbackDescriptor)
 };
 
-class Compare_WithFeedbackDescriptor : public CallInterfaceDescriptor {
+class Compare_WithFeedbackDescriptor
+    : public StaticCallInterfaceDescriptor<Compare_WithFeedbackDescriptor> {
  public:
   DEFINE_PARAMETERS(kLeft, kRight, kSlot, kFeedbackVector)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kLeft
                          MachineType::AnyTagged(),  // kRight
                          MachineType::UintPtr(),    // kSlot
                          MachineType::AnyTagged())  // kFeedbackVector
-  DECLARE_DESCRIPTOR(Compare_WithFeedbackDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(Compare_WithFeedbackDescriptor)
 };
 
-class Compare_BaselineDescriptor : public CallInterfaceDescriptor {
+class Compare_BaselineDescriptor
+    : public StaticCallInterfaceDescriptor<Compare_BaselineDescriptor> {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kLeft, kRight, kSlot)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kLeft
                          MachineType::AnyTagged(),  // kRight
                          MachineType::UintPtr())    // kSlot
-  DECLARE_DESCRIPTOR(Compare_BaselineDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(Compare_BaselineDescriptor)
+
+  static constexpr inline auto registers();
 };
 
-class Construct_BaselineDescriptor : public CallInterfaceDescriptor {
+class Construct_BaselineDescriptor
+    : public StaticJSCallInterfaceDescriptor<Construct_BaselineDescriptor> {
  public:
   DEFINE_JS_PARAMETERS_NO_CONTEXT(kSlot)
   DEFINE_JS_PARAMETER_TYPES(MachineType::UintPtr())  // kSlot
-  DECLARE_JS_COMPATIBLE_DESCRIPTOR(Construct_BaselineDescriptor,
-                                   CallInterfaceDescriptor, 1)
+  DECLARE_JS_COMPATIBLE_DESCRIPTOR(Construct_BaselineDescriptor)
 };
 
-class Construct_WithFeedbackDescriptor : public CallInterfaceDescriptor {
+class Construct_WithFeedbackDescriptor
+    : public StaticJSCallInterfaceDescriptor<Construct_WithFeedbackDescriptor> {
  public:
   // kSlot is passed in a register, kFeedbackVector on the stack.
   DEFINE_JS_PARAMETERS(kSlot, kFeedbackVector)
   DEFINE_JS_PARAMETER_TYPES(MachineType::UintPtr(),    // kSlot
                             MachineType::AnyTagged())  // kFeedbackVector
-  DECLARE_JS_COMPATIBLE_DESCRIPTOR(Construct_WithFeedbackDescriptor,
-                                   CallInterfaceDescriptor, 1)
+  DECLARE_JS_COMPATIBLE_DESCRIPTOR(Construct_WithFeedbackDescriptor)
 };
 
-class UnaryOp_WithFeedbackDescriptor : public CallInterfaceDescriptor {
+class UnaryOp_WithFeedbackDescriptor
+    : public StaticCallInterfaceDescriptor<UnaryOp_WithFeedbackDescriptor> {
  public:
   DEFINE_PARAMETERS(kValue, kSlot, kFeedbackVector)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kValue
                          MachineType::UintPtr(),    // kSlot
                          MachineType::AnyTagged())  // kFeedbackVector
-  DECLARE_DESCRIPTOR(UnaryOp_WithFeedbackDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(UnaryOp_WithFeedbackDescriptor)
 };
 
-class UnaryOp_BaselineDescriptor : public CallInterfaceDescriptor {
+class UnaryOp_BaselineDescriptor
+    : public StaticCallInterfaceDescriptor<UnaryOp_BaselineDescriptor> {
  public:
-  DEFINE_PARAMETERS(kValue, kSlot)
+  DEFINE_PARAMETERS_NO_CONTEXT(kValue, kSlot)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kValue
                          MachineType::UintPtr())    // kSlot
-  DECLARE_DESCRIPTOR(UnaryOp_BaselineDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(UnaryOp_BaselineDescriptor)
 };
 
-#define DEFINE_TFS_BUILTIN_DESCRIPTOR(Name, ...)                          \
-  class Name##Descriptor : public CallInterfaceDescriptor {               \
-   public:                                                                \
-    DEFINE_PARAMETERS(__VA_ARGS__)                                        \
-    DECLARE_DEFAULT_DESCRIPTOR(Name##Descriptor, CallInterfaceDescriptor) \
+#define DEFINE_TFS_BUILTIN_DESCRIPTOR(Name, ...)                 \
+  class Name##Descriptor                                         \
+      : public StaticCallInterfaceDescriptor<Name##Descriptor> { \
+   public:                                                       \
+    DEFINE_PARAMETERS(__VA_ARGS__)                               \
+    DECLARE_DEFAULT_DESCRIPTOR(Name##Descriptor)                 \
   };
 BUILTIN_LIST_TFS(DEFINE_TFS_BUILTIN_DESCRIPTOR)
 #undef DEFINE_TFS_BUILTIN_DESCRIPTOR
@@ -1852,11 +1967,12 @@ BUILTIN_LIST_TFS(DEFINE_TFS_BUILTIN_DESCRIPTOR)
 #undef DECLARE_DESCRIPTOR_WITH_BASE
 #undef DECLARE_DESCRIPTOR
 #undef DECLARE_JS_COMPATIBLE_DESCRIPTOR
-#undef DEFINE_FLAGS_AND_RESULT_AND_PARAMETERS
 #undef DEFINE_RESULT_AND_PARAMETERS
+#undef DEFINE_PARAMETERS_ENTRY
 #undef DEFINE_PARAMETERS
 #undef DEFINE_PARAMETERS_VARARGS
 #undef DEFINE_PARAMETERS_NO_CONTEXT
+#undef DEFINE_RESULT_AND_PARAMETERS_NO_CONTEXT
 #undef DEFINE_RESULT_AND_PARAMETER_TYPES
 #undef DEFINE_PARAMETER_TYPES
 #undef DEFINE_JS_PARAMETERS
diff --git a/chromium/v8/src/codegen/machine-type.cc b/chromium/v8/src/codegen/machine-type.cc
index 86fc480ea5b..1972c41b248 100644
--- a/chromium/v8/src/codegen/machine-type.cc
+++ b/chromium/v8/src/codegen/machine-type.cc
@@ -55,6 +55,8 @@ const char* MachineReprToString(MachineRepresentation rep) {
       return "kRepCompressedPointer";
     case MachineRepresentation::kCompressed:
       return "kRepCompressed";
+    case MachineRepresentation::kMapWord:
+      return "kRepMapWord";
   }
   UNREACHABLE();
 }
diff --git a/chromium/v8/src/codegen/machine-type.h b/chromium/v8/src/codegen/machine-type.h
index ac21d3c3e60..7a006084590 100644
--- a/chromium/v8/src/codegen/machine-type.h
+++ b/chromium/v8/src/codegen/machine-type.h
@@ -22,6 +22,19 @@ enum class MachineRepresentation : uint8_t {
   kWord16,
   kWord32,
   kWord64,
+  // (uncompressed) MapWord
+  // kMapWord is the representation of a map word, i.e. a map in the header
+  // of a HeapObject.
+  // If V8_MAP_PACKING is disabled, a map word is just the map itself. Hence
+  //     kMapWord is equivalent to kTaggedPointer -- in fact it will be
+  //     translated to kTaggedPointer during memory lowering.
+  // If V8_MAP_PACKING is enabled, a map word is a Smi-like encoding of a map
+  //     and some meta data. Memory lowering of kMapWord loads/stores
+  //     produces low-level kTagged loads/stores plus the necessary
+  //     decode/encode operations.
+  // In either case, the kMapWord representation is not used after memory
+  // lowering.
+  kMapWord,
   kTaggedSigned,       // (uncompressed) Smi
   kTaggedPointer,      // (uncompressed) HeapObject
   kTagged,             // (uncompressed) Object (Smi or HeapObject)
@@ -102,6 +115,10 @@ class MachineType {
     return representation() == MachineRepresentation::kNone;
   }
 
+  constexpr bool IsMapWord() const {
+    return representation() == MachineRepresentation::kMapWord;
+  }
+
   constexpr bool IsSigned() const {
     return semantic() == MachineSemantic::kInt32 ||
            semantic() == MachineSemantic::kInt64;
@@ -187,6 +204,9 @@ class MachineType {
     return MachineType(MachineRepresentation::kTaggedPointer,
                        MachineSemantic::kAny);
   }
+  constexpr static MachineType MapInHeader() {
+    return MachineType(MachineRepresentation::kMapWord, MachineSemantic::kAny);
+  }
   constexpr static MachineType TaggedSigned() {
     return MachineType(MachineRepresentation::kTaggedSigned,
                        MachineSemantic::kInt32);
@@ -283,7 +303,8 @@ inline bool IsFloatingPoint(MachineRepresentation rep) {
 
 inline bool CanBeTaggedPointer(MachineRepresentation rep) {
   return rep == MachineRepresentation::kTagged ||
-         rep == MachineRepresentation::kTaggedPointer;
+         rep == MachineRepresentation::kTaggedPointer ||
+         rep == MachineRepresentation::kMapWord;
 }
 
 inline bool CanBeTaggedSigned(MachineRepresentation rep) {
@@ -328,16 +349,12 @@ V8_EXPORT_PRIVATE inline constexpr int ElementSizeLog2Of(
     case MachineRepresentation::kTaggedSigned:
     case MachineRepresentation::kTaggedPointer:
     case MachineRepresentation::kTagged:
+    case MachineRepresentation::kMapWord:
     case MachineRepresentation::kCompressedPointer:
     case MachineRepresentation::kCompressed:
       return kTaggedSizeLog2;
     default:
-#if V8_HAS_CXX14_CONSTEXPR
       UNREACHABLE();
-#else
-      // Return something for older compilers.
-      return -1;
-#endif
   }
 }
 
diff --git a/chromium/v8/src/codegen/macro-assembler.h b/chromium/v8/src/codegen/macro-assembler.h
index ce3ccbf332b..484ec9e4b2c 100644
--- a/chromium/v8/src/codegen/macro-assembler.h
+++ b/chromium/v8/src/codegen/macro-assembler.h
@@ -10,7 +10,7 @@
 #include "src/heap/heap.h"
 
 // Helper types to make boolean flag easier to read at call-site.
-enum InvokeFlag { CALL_FUNCTION, JUMP_FUNCTION };
+enum class InvokeType { kCall, kJump };
 
 // Flags used for the AllocateInNewSpace functions.
 enum AllocationFlags {
@@ -28,6 +28,10 @@ enum AllocationFlags {
   PRETENURE = 1 << 3,
 };
 
+enum class RememberedSetAction { kOmit, kEmit };
+
+enum class SmiCheck { kOmit, kInline };
+
 // This is the only place allowed to include the platform-specific headers.
 #define INCLUDED_FROM_MACRO_ASSEMBLER_H
 #if V8_TARGET_ARCH_IA32
diff --git a/chromium/v8/src/codegen/mips/assembler-mips.cc b/chromium/v8/src/codegen/mips/assembler-mips.cc
index 2ef08ae87c2..c254860b147 100644
--- a/chromium/v8/src/codegen/mips/assembler-mips.cc
+++ b/chromium/v8/src/codegen/mips/assembler-mips.cc
@@ -261,29 +261,27 @@ static const int kNegOffset = 0x00008000;
 // operations as post-increment of sp.
 const Instr kPopInstruction = ADDIU | (sp.code() << kRsShift) |
                               (sp.code() << kRtShift) |
-                              (kPointerSize & kImm16Mask);  // NOLINT
+                              (kPointerSize & kImm16Mask);
 // addiu(sp, sp, -4) part of Push(r) operation as pre-decrement of sp.
 const Instr kPushInstruction = ADDIU | (sp.code() << kRsShift) |
                                (sp.code() << kRtShift) |
-                               (-kPointerSize & kImm16Mask);  // NOLINT
+                               (-kPointerSize & kImm16Mask);
 // sw(r, MemOperand(sp, 0))
-const Instr kPushRegPattern =
-    SW | (sp.code() << kRsShift) | (0 & kImm16Mask);  // NOLINT
+const Instr kPushRegPattern = SW | (sp.code() << kRsShift) | (0 & kImm16Mask);
 //  lw(r, MemOperand(sp, 0))
-const Instr kPopRegPattern =
-    LW | (sp.code() << kRsShift) | (0 & kImm16Mask);  // NOLINT
+const Instr kPopRegPattern = LW | (sp.code() << kRsShift) | (0 & kImm16Mask);
 
 const Instr kLwRegFpOffsetPattern =
-    LW | (fp.code() << kRsShift) | (0 & kImm16Mask);  // NOLINT
+    LW | (fp.code() << kRsShift) | (0 & kImm16Mask);
 
 const Instr kSwRegFpOffsetPattern =
-    SW | (fp.code() << kRsShift) | (0 & kImm16Mask);  // NOLINT
+    SW | (fp.code() << kRsShift) | (0 & kImm16Mask);
 
 const Instr kLwRegFpNegOffsetPattern =
-    LW | (fp.code() << kRsShift) | (kNegOffset & kImm16Mask);  // NOLINT
+    LW | (fp.code() << kRsShift) | (kNegOffset & kImm16Mask);
 
 const Instr kSwRegFpNegOffsetPattern =
-    SW | (fp.code() << kRsShift) | (kNegOffset & kImm16Mask);  // NOLINT
+    SW | (fp.code() << kRsShift) | (kNegOffset & kImm16Mask);
 // A mask for the Rt register for push, pop, lw, sw instructions.
 const Instr kRtMask = kRtFieldMask;
 const Instr kLwSwInstrTypeMask = 0xFFE00000;
diff --git a/chromium/v8/src/codegen/mips/assembler-mips.h b/chromium/v8/src/codegen/mips/assembler-mips.h
index ccdea03a79c..47bdf26d551 100644
--- a/chromium/v8/src/codegen/mips/assembler-mips.h
+++ b/chromium/v8/src/codegen/mips/assembler-mips.h
@@ -1907,7 +1907,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
 
 class EnsureSpace {
  public:
-  explicit inline EnsureSpace(Assembler* assembler);
+  explicit V8_INLINE EnsureSpace(Assembler* assembler);
 };
 
 class V8_EXPORT_PRIVATE V8_NODISCARD UseScratchRegisterScope {
diff --git a/chromium/v8/src/codegen/mips/interface-descriptors-mips-inl.h b/chromium/v8/src/codegen/mips/interface-descriptors-mips-inl.h
new file mode 100644
index 00000000000..edea1b3844a
--- /dev/null
+++ b/chromium/v8/src/codegen/mips/interface-descriptors-mips-inl.h
@@ -0,0 +1,258 @@
+// Copyright 2012 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_CODEGEN_MIPS_INTERFACE_DESCRIPTORS_MIPS_INL_H_
+#define V8_CODEGEN_MIPS_INTERFACE_DESCRIPTORS_MIPS_INL_H_
+
+#if V8_TARGET_ARCH_MIPS
+
+#include "src/codegen/interface-descriptors.h"
+#include "src/execution/frames.h"
+
+namespace v8 {
+namespace internal {
+
+constexpr auto CallInterfaceDescriptor::DefaultRegisterArray() {
+  auto registers = RegisterArray(a0, a1, a2, a3, t0);
+  STATIC_ASSERT(registers.size() == kMaxBuiltinRegisterParams);
+  return registers;
+}
+
+// static
+constexpr auto RecordWriteDescriptor::registers() {
+  return RegisterArray(a0, a1, a2, a3, kReturnRegister0);
+}
+
+// static
+constexpr auto DynamicCheckMapsDescriptor::registers() {
+  return RegisterArray(kReturnRegister0, a0, a1, a2, cp);
+}
+
+// static
+constexpr auto EphemeronKeyBarrierDescriptor::registers() {
+  return RegisterArray(a0, a1, a2, a3, kReturnRegister0);
+}
+
+// static
+constexpr Register LoadDescriptor::ReceiverRegister() { return a1; }
+// static
+constexpr Register LoadDescriptor::NameRegister() { return a2; }
+// static
+constexpr Register LoadDescriptor::SlotRegister() { return a0; }
+
+// static
+constexpr Register LoadWithVectorDescriptor::VectorRegister() { return a3; }
+
+// static
+constexpr Register
+LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
+  return t0;
+}
+
+// static
+constexpr Register StoreDescriptor::ReceiverRegister() { return a1; }
+// static
+constexpr Register StoreDescriptor::NameRegister() { return a2; }
+// static
+constexpr Register StoreDescriptor::ValueRegister() { return a0; }
+// static
+constexpr Register StoreDescriptor::SlotRegister() { return t0; }
+
+// static
+constexpr Register StoreWithVectorDescriptor::VectorRegister() { return a3; }
+
+// static
+constexpr Register StoreTransitionDescriptor::MapRegister() { return t1; }
+
+// static
+constexpr Register ApiGetterDescriptor::HolderRegister() { return a0; }
+// static
+constexpr Register ApiGetterDescriptor::CallbackRegister() { return a3; }
+
+// static
+constexpr Register GrowArrayElementsDescriptor::ObjectRegister() { return a0; }
+// static
+constexpr Register GrowArrayElementsDescriptor::KeyRegister() { return a3; }
+
+// static
+constexpr Register BaselineLeaveFrameDescriptor::ParamsSizeRegister() {
+  // TODO(v8:11421): Implement on this platform.
+  return a3;
+}
+
+// static
+constexpr Register BaselineLeaveFrameDescriptor::WeightRegister() {
+  // TODO(v8:11421): Implement on this platform.
+  return t0;
+}
+
+// static
+constexpr Register TypeConversionDescriptor::ArgumentRegister() { return a0; }
+
+// static
+constexpr auto TypeofDescriptor::registers() { return RegisterArray(a3); }
+
+// static
+constexpr auto CallTrampolineDescriptor::registers() {
+  // a1: target
+  // a0: number of arguments
+  return RegisterArray(a1, a0);
+}
+
+// static
+constexpr auto CallVarargsDescriptor::registers() {
+  // a0 : number of arguments (on the stack, not including receiver)
+  // a1 : the target to call
+  // t0 : arguments list length (untagged)
+  // a2 : arguments list (FixedArray)
+  return RegisterArray(a1, a0, t0, a2);
+}
+
+// static
+constexpr auto CallForwardVarargsDescriptor::registers() {
+  // a1: the target to call
+  // a0: number of arguments
+  // a2: start index (to support rest parameters)
+  return RegisterArray(a1, a0, a2);
+}
+
+// static
+constexpr auto CallFunctionTemplateDescriptor::registers() {
+  // a1 : function template info
+  // a0 : number of arguments (on the stack, not including receiver)
+  return RegisterArray(a1, a0);
+}
+
+// static
+constexpr auto CallWithSpreadDescriptor::registers() {
+  // a0 : number of arguments (on the stack, not including receiver)
+  // a1 : the target to call
+  // a2 : the object to spread
+  return RegisterArray(a1, a0, a2);
+}
+
+// static
+constexpr auto CallWithArrayLikeDescriptor::registers() {
+  // a1 : the target to call
+  // a2 : the arguments list
+  return RegisterArray(a1, a2);
+}
+
+// static
+constexpr auto ConstructVarargsDescriptor::registers() {
+  // a0 : number of arguments (on the stack, not including receiver)
+  // a1 : the target to call
+  // a3 : the new target
+  // t0 : arguments list length (untagged)
+  // a2 : arguments list (FixedArray)
+  return RegisterArray(a1, a3, a0, t0, a2);
+}
+
+// static
+constexpr auto ConstructForwardVarargsDescriptor::registers() {
+  // a1: the target to call
+  // a3: new target
+  // a0: number of arguments
+  // a2: start index (to support rest parameters)
+  return RegisterArray(a1, a3, a0, a2);
+}
+
+// static
+constexpr auto ConstructWithSpreadDescriptor::registers() {
+  // a0 : number of arguments (on the stack, not including receiver)
+  // a1 : the target to call
+  // a3 : the new target
+  // a2 : the object to spread
+  return RegisterArray(a1, a3, a0, a2);
+}
+
+// static
+constexpr auto ConstructWithArrayLikeDescriptor::registers() {
+  // a1 : the target to call
+  // a3 : the new target
+  // a2 : the arguments list
+  return RegisterArray(a1, a3, a2);
+}
+
+// static
+constexpr auto ConstructStubDescriptor::registers() {
+  // a1: target
+  // a3: new target
+  // a0: number of arguments
+  // a2: allocation site or undefined
+  return RegisterArray(a1, a3, a0, a2);
+}
+
+// static
+constexpr auto AbortDescriptor::registers() { return RegisterArray(a0); }
+
+// static
+constexpr auto CompareDescriptor::registers() { return RegisterArray(a1, a0); }
+
+// static
+constexpr auto Compare_BaselineDescriptor::registers() {
+  return RegisterArray(a1, a0, a2);
+}
+
+// static
+constexpr auto BinaryOpDescriptor::registers() { return RegisterArray(a1, a0); }
+
+// static
+constexpr auto BinaryOp_BaselineDescriptor::registers() {
+  // TODO(v8:11421): Implement on this platform.
+  return RegisterArray(a1, a0, a2);
+}
+
+// static
+constexpr auto ApiCallbackDescriptor::registers() {
+  // a1 : kApiFunctionAddress
+  // a2 : kArgc
+  // a3 : kCallData
+  // a0 : kHolder
+  return RegisterArray(a1, a2, a3, a0);
+}
+
+// static
+constexpr auto InterpreterDispatchDescriptor::registers() {
+  return RegisterArray(
+      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
+      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister);
+}
+
+// static
+constexpr auto InterpreterPushArgsThenCallDescriptor::registers() {
+  // a0 : argument count (not including receiver
+  // a2 : address of first argument
+  // a1 : the target callable to be call
+  return RegisterArray(a0, a2, a1);
+}
+
+// static
+constexpr auto InterpreterPushArgsThenConstructDescriptor::registers() {
+  // a0 : argument count (not including receiver)
+  // t4 : address of the first argument
+  // a1 : constructor to call
+  // a3 : new target
+  // a2 : allocation site feedback if available, undefined otherwise
+  return RegisterArray(a0, t4, a1, a3, a2);
+}
+
+// static
+constexpr auto ResumeGeneratorDescriptor::registers() {
+  // v0 : the value to pass to the generator
+  // a1 : the JSGeneratorObject to resume
+  return RegisterArray(v0, a1);
+}
+
+// static
+constexpr auto RunMicrotasksEntryDescriptor::registers() {
+  return RegisterArray(a0, a1);
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TARGET_ARCH_MIPS
+
+#endif  // V8_CODEGEN_MIPS_INTERFACE_DESCRIPTORS_MIPS_INL_H_
diff --git a/chromium/v8/src/codegen/mips/interface-descriptors-mips.cc b/chromium/v8/src/codegen/mips/interface-descriptors-mips.cc
deleted file mode 100644
index f41a0e14ca7..00000000000
--- a/chromium/v8/src/codegen/mips/interface-descriptors-mips.cc
+++ /dev/null
@@ -1,332 +0,0 @@
-// Copyright 2012 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#if V8_TARGET_ARCH_MIPS
-
-#include "src/codegen/interface-descriptors.h"
-
-#include "src/execution/frames.h"
-
-namespace v8 {
-namespace internal {
-
-const Register CallInterfaceDescriptor::ContextRegister() { return cp; }
-
-void CallInterfaceDescriptor::DefaultInitializePlatformSpecific(
-    CallInterfaceDescriptorData* data, int register_parameter_count) {
-  const Register default_stub_registers[] = {a0, a1, a2, a3, t0};
-  CHECK_LE(static_cast<size_t>(register_parameter_count),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(register_parameter_count,
-                                   default_stub_registers);
-}
-
-// On MIPS it is not allowed to use odd numbered floating point registers
-// (e.g. f1, f3, etc.) for parameters. This can happen if we use
-// DefaultInitializePlatformSpecific to assign float registers for parameters.
-// E.g if fourth parameter goes to float register, f7 would be assigned for
-// parameter (a3 casted to int is 7).
-bool CallInterfaceDescriptor::IsValidFloatParameterRegister(Register reg) {
-  return reg.code() % 2 == 0;
-}
-
-void WasmI32AtomicWait32Descriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {a0, a1, a2, a3};
-  CHECK_EQ(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void WasmI64AtomicWait32Descriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {a0, a1, a2, a3, t0};
-  CHECK_EQ(static_cast<size_t>(kParameterCount - kStackArgumentsCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount - kStackArgumentsCount,
-                                   default_stub_registers);
-}
-
-void RecordWriteDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {a0, a1, a2, a3, kReturnRegister0};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void DynamicCheckMapsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register default_stub_registers[] = {kReturnRegister0, a0, a1, a2, cp};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void EphemeronKeyBarrierDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {a0, a1, a2, a3, kReturnRegister0};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-const Register LoadDescriptor::ReceiverRegister() { return a1; }
-const Register LoadDescriptor::NameRegister() { return a2; }
-const Register LoadDescriptor::SlotRegister() { return a0; }
-
-const Register LoadWithVectorDescriptor::VectorRegister() { return a3; }
-
-const Register
-LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
-  return t0;
-}
-
-const Register StoreDescriptor::ReceiverRegister() { return a1; }
-const Register StoreDescriptor::NameRegister() { return a2; }
-const Register StoreDescriptor::ValueRegister() { return a0; }
-const Register StoreDescriptor::SlotRegister() { return t0; }
-
-const Register StoreWithVectorDescriptor::VectorRegister() { return a3; }
-
-const Register StoreTransitionDescriptor::SlotRegister() { return t0; }
-const Register StoreTransitionDescriptor::VectorRegister() { return a3; }
-const Register StoreTransitionDescriptor::MapRegister() { return t1; }
-
-const Register ApiGetterDescriptor::HolderRegister() { return a0; }
-const Register ApiGetterDescriptor::CallbackRegister() { return a3; }
-
-const Register GrowArrayElementsDescriptor::ObjectRegister() { return a0; }
-const Register GrowArrayElementsDescriptor::KeyRegister() { return a3; }
-
-const Register BaselineLeaveFrameDescriptor::ParamsSizeRegister() {
-  // TODO(v8:11421): Implement on this platform.
-  UNREACHABLE();
-}
-const Register BaselineLeaveFrameDescriptor::WeightRegister() {
-  // TODO(v8:11421): Implement on this platform.
-  UNREACHABLE();
-}
-
-// static
-const Register TypeConversionDescriptor::ArgumentRegister() { return a0; }
-
-void TypeofDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {a3};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1: target
-  // a0: number of arguments
-  Register registers[] = {a1, a0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a0 : number of arguments (on the stack, not including receiver)
-  // a1 : the target to call
-  // t0 : arguments list length (untagged)
-  // a2 : arguments list (FixedArray)
-  Register registers[] = {a1, a0, t0, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1: the target to call
-  // a0: number of arguments
-  // a2: start index (to support rest parameters)
-  Register registers[] = {a1, a0, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallFunctionTemplateDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1 : function template info
-  // a0 : number of arguments (on the stack, not including receiver)
-  Register registers[] = {a1, a0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a0 : number of arguments (on the stack, not including receiver)
-  // a1 : the target to call
-  // a2 : the object to spread
-  Register registers[] = {a1, a0, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1 : the target to call
-  // a2 : the arguments list
-  Register registers[] = {a1, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a0 : number of arguments (on the stack, not including receiver)
-  // a1 : the target to call
-  // a3 : the new target
-  // t0 : arguments list length (untagged)
-  // a2 : arguments list (FixedArray)
-  Register registers[] = {a1, a3, a0, t0, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1: the target to call
-  // a3: new target
-  // a0: number of arguments
-  // a2: start index (to support rest parameters)
-  Register registers[] = {a1, a3, a0, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a0 : number of arguments (on the stack, not including receiver)
-  // a1 : the target to call
-  // a3 : the new target
-  // a2 : the object to spread
-  Register registers[] = {a1, a3, a0, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1 : the target to call
-  // a3 : the new target
-  // a2 : the arguments list
-  Register registers[] = {a1, a3, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructStubDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1: target
-  // a3: new target
-  // a0: number of arguments
-  // a2: allocation site or undefined
-  Register registers[] = {a1, a3, a0, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void AbortDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {a0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CompareDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {a1, a0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void Compare_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // TODO(v8:11421): Implement on this platform.
-  InitializePlatformUnimplemented(data, kParameterCount);
-}
-
-void BinaryOpDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {a1, a0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void BinaryOp_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // TODO(v8:11421): Implement on this platform.
-  InitializePlatformUnimplemented(data, kParameterCount);
-}
-
-void ApiCallbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      a1,  // kApiFunctionAddress
-      a2,  // kArgc
-      a3,  // kCallData
-      a0,  // kHolder
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterDispatchDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
-      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenCallDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      a0,  // argument count (not including receiver)
-      a2,  // address of first argument
-      a1   // the target callable to be call
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenConstructDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      a0,  // argument count (not including receiver)
-      t4,  // address of the first argument
-      a1,  // constructor to call
-      a3,  // new target
-      a2,  // allocation site feedback if available, undefined otherwise
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ResumeGeneratorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      v0,  // the value to pass to the generator
-      a1   // the JSGeneratorObject to resume
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void FrameDropperTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      a1,  // loaded new FP
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void RunMicrotasksEntryDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {a0, a1};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_TARGET_ARCH_MIPS
diff --git a/chromium/v8/src/codegen/mips/macro-assembler-mips.cc b/chromium/v8/src/codegen/mips/macro-assembler-mips.cc
index 8bbdbca6627..d48b441c7bd 100644
--- a/chromium/v8/src/codegen/mips/macro-assembler-mips.cc
+++ b/chromium/v8/src/codegen/mips/macro-assembler-mips.cc
@@ -12,6 +12,7 @@
 #include "src/codegen/callable.h"
 #include "src/codegen/code-factory.h"
 #include "src/codegen/external-reference-table.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/macro-assembler.h"
 #include "src/codegen/register-configuration.h"
 #include "src/debug/debug.h"
@@ -64,7 +65,7 @@ int TurboAssembler::RequiredStackSizeForCallerSaved(SaveFPRegsMode fp_mode,
   RegList list = kJSCallerSaved & ~exclusions;
   bytes += NumRegs(list) * kPointerSize;
 
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     bytes += NumRegs(kCallerSavedFPU) * kDoubleSize;
   }
 
@@ -89,7 +90,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
   MultiPush(list);
   bytes += NumRegs(list) * kPointerSize;
 
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     MultiPushFPU(kCallerSavedFPU);
     bytes += NumRegs(kCallerSavedFPU) * kDoubleSize;
   }
@@ -100,7 +101,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
 int TurboAssembler::PopCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
                                    Register exclusion2, Register exclusion3) {
   int bytes = 0;
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     MultiPopFPU(kCallerSavedFPU);
     bytes += NumRegs(kCallerSavedFPU) * kDoubleSize;
   }
@@ -179,7 +180,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   Label done;
 
   // Skip barrier if writing a smi.
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     JumpIfSmi(value, &done);
   }
 
@@ -188,7 +189,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   DCHECK(IsAligned(offset, kPointerSize));
 
   Addu(dst, object, Operand(offset - kHeapObjectTag));
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     BlockTrampolinePoolScope block_trampoline_pool(this);
     Label ok;
     And(t8, dst, Operand(kPointerSize - 1));
@@ -198,13 +199,13 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   }
 
   RecordWrite(object, dst, value, ra_status, save_fp, remembered_set_action,
-              OMIT_SMI_CHECK);
+              SmiCheck::kOmit);
 
   bind(&done);
 
   // Clobber clobbered input registers when running with the debug-code flag
   // turned on to provoke errors.
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     li(value, Operand(bit_cast<int32_t>(kZapValue + 4)));
     li(dst, Operand(bit_cast<int32_t>(kZapValue + 8)));
   }
@@ -336,7 +337,7 @@ void MacroAssembler::RecordWrite(Register object, Register address,
   DCHECK(!AreAliased(object, address, value, t8));
   DCHECK(!AreAliased(object, address, value, t9));
 
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     UseScratchRegisterScope temps(this);
     Register scratch = temps.Acquire();
     lw(scratch, MemOperand(address));
@@ -344,7 +345,7 @@ void MacroAssembler::RecordWrite(Register object, Register address,
            Operand(value));
   }
 
-  if ((remembered_set_action == OMIT_REMEMBERED_SET &&
+  if ((remembered_set_action == RememberedSetAction::kOmit &&
        !FLAG_incremental_marking) ||
       FLAG_disable_write_barriers) {
     return;
@@ -354,7 +355,7 @@ void MacroAssembler::RecordWrite(Register object, Register address,
   // catch stores of smis and stores into the young generation.
   Label done;
 
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     DCHECK_EQ(0, kSmiTag);
     JumpIfSmi(value, &done);
   }
@@ -379,7 +380,7 @@ void MacroAssembler::RecordWrite(Register object, Register address,
 
   // Clobber clobbered registers when running with the debug-code flag
   // turned on to provoke errors.
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     li(address, Operand(bit_cast<int32_t>(kZapValue + 12)));
     li(value, Operand(bit_cast<int32_t>(kZapValue + 16)));
   }
@@ -4176,14 +4177,6 @@ void TurboAssembler::PushArray(Register array, Register size, Register scratch,
   }
 }
 
-void MacroAssembler::MaybeDropFrames() {
-  // Check whether we need to drop frames to restart a function on the stack.
-  li(a1, ExternalReference::debug_restart_fp_address(isolate()));
-  lw(a1, MemOperand(a1));
-  Jump(BUILTIN_CODE(isolate(), FrameDropperTrampoline), RelocInfo::CODE_TARGET,
-       ne, a1, Operand(zero_reg));
-}
-
 // ---------------------------------------------------------------------------
 // Exception handling.
 
@@ -4373,7 +4366,7 @@ void MacroAssembler::StackOverflowCheck(Register num_args, Register scratch1,
 
 void MacroAssembler::InvokePrologue(Register expected_parameter_count,
                                     Register actual_parameter_count,
-                                    Label* done, InvokeFlag flag) {
+                                    Label* done, InvokeType type) {
   Label regular_invoke;
 
   //  a0: actual arguments count
@@ -4484,9 +4477,9 @@ void MacroAssembler::CheckDebugHook(Register fun, Register new_target,
 void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
                                         Register expected_parameter_count,
                                         Register actual_parameter_count,
-                                        InvokeFlag flag) {
+                                        InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
   DCHECK_EQ(function, a1);
   DCHECK_IMPLIES(new_target.is_valid(), new_target == a3);
 
@@ -4500,19 +4493,21 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
   }
 
   Label done;
-  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, flag);
+  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, type);
   // We call indirectly through the code field in the function to
   // allow recompilation to take effect without changing any of the
   // call sites.
   Register code = kJavaScriptCallCodeStartRegister;
   lw(code, FieldMemOperand(function, JSFunction::kCodeOffset));
-  if (flag == CALL_FUNCTION) {
-    Addu(code, code, Code::kHeaderSize - kHeapObjectTag);
-    Call(code);
-  } else {
-    DCHECK(flag == JUMP_FUNCTION);
-    Addu(code, code, Code::kHeaderSize - kHeapObjectTag);
-    Jump(code);
+  switch (type) {
+    case InvokeType::kCall:
+      Addu(code, code, Code::kHeaderSize - kHeapObjectTag);
+      Call(code);
+      break;
+    case InvokeType::kJump:
+      Addu(code, code, Code::kHeaderSize - kHeapObjectTag);
+      Jump(code);
+      break;
   }
 
   // Continue here if InvokePrologue does handle the invocation due to
@@ -4522,9 +4517,9 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
 
 void MacroAssembler::InvokeFunctionWithNewTarget(
     Register function, Register new_target, Register actual_parameter_count,
-    InvokeFlag flag) {
+    InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
 
   // Contract with called JS functions requires that function is passed in a1.
   DCHECK_EQ(function, a1);
@@ -4538,15 +4533,15 @@ void MacroAssembler::InvokeFunctionWithNewTarget(
                       SharedFunctionInfo::kFormalParameterCountOffset));
 
   InvokeFunctionCode(function, new_target, expected_reg, actual_parameter_count,
-                     flag);
+                     type);
 }
 
 void MacroAssembler::InvokeFunction(Register function,
                                     Register expected_parameter_count,
                                     Register actual_parameter_count,
-                                    InvokeFlag flag) {
+                                    InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
 
   // Contract with called JS functions requires that function is passed in a1.
   DCHECK_EQ(function, a1);
@@ -4555,7 +4550,7 @@ void MacroAssembler::InvokeFunction(Register function,
   lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
 
   InvokeFunctionCode(a1, no_reg, expected_parameter_count,
-                     actual_parameter_count, flag);
+                     actual_parameter_count, type);
 }
 
 // ---------------------------------------------------------------------------
@@ -4699,8 +4694,8 @@ void MacroAssembler::JumpToExternalReference(const ExternalReference& builtin,
                                              BranchDelaySlot bd,
                                              bool builtin_exit_frame) {
   PrepareCEntryFunction(builtin);
-  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, kDontSaveFPRegs,
-                                          kArgvOnStack, builtin_exit_frame);
+  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, SaveFPRegsMode::kIgnore,
+                                          ArgvMode::kStack, builtin_exit_frame);
   Jump(code, RelocInfo::CODE_TARGET, al, zero_reg, Operand(zero_reg), bd);
 }
 
@@ -4746,7 +4741,7 @@ void TurboAssembler::DebugBreak() { stop(); }
 
 void TurboAssembler::Assert(Condition cc, AbortReason reason, Register rs,
                             Operand rt) {
-  if (emit_debug_code()) Check(cc, reason, rs, rt);
+  if (FLAG_debug_code) Check(cc, reason, rs, rt);
 }
 
 void TurboAssembler::Check(Condition cc, AbortReason reason, Register rs,
@@ -4761,11 +4756,11 @@ void TurboAssembler::Check(Condition cc, AbortReason reason, Register rs,
 void TurboAssembler::Abort(AbortReason reason) {
   Label abort_start;
   bind(&abort_start);
-#ifdef DEBUG
-  const char* msg = GetAbortReason(reason);
-  RecordComment("Abort message: ");
-  RecordComment(msg);
-#endif
+  if (FLAG_code_comments) {
+    const char* msg = GetAbortReason(reason);
+    RecordComment("Abort message: ");
+    RecordComment(msg);
+  }
 
   // Avoid emitting call to builtin if requested.
   if (trap_on_abort()) {
@@ -4885,7 +4880,7 @@ void MacroAssembler::EnterExitFrame(bool save_doubles, int stack_space,
   // Set up new frame pointer.
   addiu(fp, sp, ExitFrameConstants::kFixedFrameSizeFromFp);
 
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     sw(zero_reg, MemOperand(fp, ExitFrameConstants::kSPOffset));
   }
 
@@ -4999,7 +4994,7 @@ int TurboAssembler::ActivationFrameAlignment() {
 }
 
 void MacroAssembler::AssertStackIsAligned() {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     const int frame_alignment = ActivationFrameAlignment();
     const int frame_alignment_mask = frame_alignment - 1;
 
@@ -5032,7 +5027,7 @@ void MacroAssembler::JumpIfNotSmi(Register value, Label* not_smi_label,
 }
 
 void MacroAssembler::AssertNotSmi(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     UseScratchRegisterScope temps(this);
     Register scratch = temps.Acquire();
@@ -5042,7 +5037,7 @@ void MacroAssembler::AssertNotSmi(Register object) {
 }
 
 void MacroAssembler::AssertSmi(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     UseScratchRegisterScope temps(this);
     Register scratch = temps.Acquire();
@@ -5052,7 +5047,7 @@ void MacroAssembler::AssertSmi(Register object) {
 }
 
 void MacroAssembler::AssertConstructor(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     BlockTrampolinePoolScope block_trampoline_pool(this);
     STATIC_ASSERT(kSmiTag == 0);
     SmiTst(object, t8);
@@ -5067,7 +5062,7 @@ void MacroAssembler::AssertConstructor(Register object) {
 }
 
 void MacroAssembler::AssertFunction(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     BlockTrampolinePoolScope block_trampoline_pool(this);
     STATIC_ASSERT(kSmiTag == 0);
     SmiTst(object, t8);
@@ -5083,7 +5078,7 @@ void MacroAssembler::AssertFunction(Register object) {
 }
 
 void MacroAssembler::AssertBoundFunction(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     BlockTrampolinePoolScope block_trampoline_pool(this);
     STATIC_ASSERT(kSmiTag == 0);
     SmiTst(object, t8);
@@ -5096,7 +5091,7 @@ void MacroAssembler::AssertBoundFunction(Register object) {
 }
 
 void MacroAssembler::AssertGeneratorObject(Register object) {
-  if (!emit_debug_code()) return;
+  if (!FLAG_debug_code) return;
   BlockTrampolinePoolScope block_trampoline_pool(this);
   STATIC_ASSERT(kSmiTag == 0);
   SmiTst(object, t8);
@@ -5123,7 +5118,7 @@ void MacroAssembler::AssertGeneratorObject(Register object) {
 
 void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
                                                      Register scratch) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label done_checking;
     AssertNotSmi(object);
     LoadRoot(scratch, RootIndex::kUndefinedValue);
@@ -5416,7 +5411,7 @@ void TurboAssembler::CallCFunctionHelper(Register function_base,
   // PrepareCallCFunction. The C function must be called via t9, for mips ABI.
 
 #if V8_HOST_ARCH_MIPS
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     int frame_alignment = base::OS::ActivationFrameAlignment();
     int frame_alignment_mask = frame_alignment - 1;
     if (frame_alignment > kPointerSize) {
diff --git a/chromium/v8/src/codegen/mips/macro-assembler-mips.h b/chromium/v8/src/codegen/mips/macro-assembler-mips.h
index 8d54e0b737c..8a82eea6fa5 100644
--- a/chromium/v8/src/codegen/mips/macro-assembler-mips.h
+++ b/chromium/v8/src/codegen/mips/macro-assembler-mips.h
@@ -45,8 +45,6 @@ enum LiFlags {
   CONSTANT_SIZE = 1
 };
 
-enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
-enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
 enum RAStatus { kRAHasNotBeenSaved, kRAHasBeenSaved };
 
 Register GetRegisterThatIsNotOneOf(Register reg1, Register reg2 = no_reg,
@@ -974,8 +972,8 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   void RecordWriteField(
       Register object, int offset, Register value, Register scratch,
       RAStatus ra_status, SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
   // For a given |object| notify the garbage collector that the slot |address|
   // has been written.  |value| is the object being stored. The value and
@@ -983,8 +981,8 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   void RecordWrite(
       Register object, Register address, Register value, RAStatus ra_status,
       SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
   void Pref(int32_t hint, const MemOperand& rs);
 
@@ -1016,7 +1014,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // Invoke the JavaScript function code by either calling or jumping.
   void InvokeFunctionCode(Register function, Register new_target,
                           Register expected_parameter_count,
-                          Register actual_parameter_count, InvokeFlag flag);
+                          Register actual_parameter_count, InvokeType type);
 
   // On function call, call into the debugger if necessary.
   void CheckDebugHook(Register fun, Register new_target,
@@ -1027,13 +1025,10 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // current context to the context in the function before invoking.
   void InvokeFunctionWithNewTarget(Register function, Register new_target,
                                    Register actual_parameter_count,
-                                   InvokeFlag flag);
+                                   InvokeType type);
 
   void InvokeFunction(Register function, Register expected_parameter_count,
-                      Register actual_parameter_count, InvokeFlag flag);
-
-  // Frame restart support.
-  void MaybeDropFrames();
+                      Register actual_parameter_count, InvokeType type);
 
   // Exception handling.
 
@@ -1057,18 +1052,18 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
 
   // Call a runtime routine.
   void CallRuntime(const Runtime::Function* f, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs);
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore);
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId fid,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     const Runtime::Function* function = Runtime::FunctionForId(fid);
     CallRuntime(function, function->nargs, save_doubles);
   }
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId id, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     CallRuntime(Runtime::FunctionForId(id), num_arguments, save_doubles);
   }
 
@@ -1155,7 +1150,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // Helper functions for generating invokes.
   void InvokePrologue(Register expected_parameter_count,
                       Register actual_parameter_count, Label* done,
-                      InvokeFlag flag);
+                      InvokeType type);
 
   // Compute memory operands for safepoint stack slots.
   static int SafepointRegisterStackIndex(int reg_code);
diff --git a/chromium/v8/src/codegen/mips64/assembler-mips64.cc b/chromium/v8/src/codegen/mips64/assembler-mips64.cc
index 7f7ebd2c736..70a02ddb6ff 100644
--- a/chromium/v8/src/codegen/mips64/assembler-mips64.cc
+++ b/chromium/v8/src/codegen/mips64/assembler-mips64.cc
@@ -235,29 +235,27 @@ void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
 // operations as post-increment of sp.
 const Instr kPopInstruction = DADDIU | (sp.code() << kRsShift) |
                               (sp.code() << kRtShift) |
-                              (kPointerSize & kImm16Mask);  // NOLINT
+                              (kPointerSize & kImm16Mask);
 // daddiu(sp, sp, -8) part of Push(r) operation as pre-decrement of sp.
 const Instr kPushInstruction = DADDIU | (sp.code() << kRsShift) |
                                (sp.code() << kRtShift) |
-                               (-kPointerSize & kImm16Mask);  // NOLINT
+                               (-kPointerSize & kImm16Mask);
 // Sd(r, MemOperand(sp, 0))
-const Instr kPushRegPattern =
-    SD | (sp.code() << kRsShift) | (0 & kImm16Mask);  // NOLINT
+const Instr kPushRegPattern = SD | (sp.code() << kRsShift) | (0 & kImm16Mask);
 //  Ld(r, MemOperand(sp, 0))
-const Instr kPopRegPattern =
-    LD | (sp.code() << kRsShift) | (0 & kImm16Mask);  // NOLINT
+const Instr kPopRegPattern = LD | (sp.code() << kRsShift) | (0 & kImm16Mask);
 
 const Instr kLwRegFpOffsetPattern =
-    LW | (fp.code() << kRsShift) | (0 & kImm16Mask);  // NOLINT
+    LW | (fp.code() << kRsShift) | (0 & kImm16Mask);
 
 const Instr kSwRegFpOffsetPattern =
-    SW | (fp.code() << kRsShift) | (0 & kImm16Mask);  // NOLINT
+    SW | (fp.code() << kRsShift) | (0 & kImm16Mask);
 
 const Instr kLwRegFpNegOffsetPattern =
-    LW | (fp.code() << kRsShift) | (kNegOffset & kImm16Mask);  // NOLINT
+    LW | (fp.code() << kRsShift) | (kNegOffset & kImm16Mask);
 
 const Instr kSwRegFpNegOffsetPattern =
-    SW | (fp.code() << kRsShift) | (kNegOffset & kImm16Mask);  // NOLINT
+    SW | (fp.code() << kRsShift) | (kNegOffset & kImm16Mask);
 // A mask for the Rt register for push, pop, lw, sw instructions.
 const Instr kRtMask = kRtFieldMask;
 const Instr kLwSwInstrTypeMask = 0xFFE00000;
diff --git a/chromium/v8/src/codegen/mips64/interface-descriptors-mips64-inl.h b/chromium/v8/src/codegen/mips64/interface-descriptors-mips64-inl.h
new file mode 100644
index 00000000000..62e32776ef1
--- /dev/null
+++ b/chromium/v8/src/codegen/mips64/interface-descriptors-mips64-inl.h
@@ -0,0 +1,258 @@
+// Copyright 2012 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_CODEGEN_MIPS64_INTERFACE_DESCRIPTORS_MIPS64_INL_H_
+#define V8_CODEGEN_MIPS64_INTERFACE_DESCRIPTORS_MIPS64_INL_H_
+
+#if V8_TARGET_ARCH_MIPS64
+
+#include "src/codegen/interface-descriptors.h"
+#include "src/execution/frames.h"
+
+namespace v8 {
+namespace internal {
+
+constexpr auto CallInterfaceDescriptor::DefaultRegisterArray() {
+  auto registers = RegisterArray(a0, a1, a2, a3, a4);
+  STATIC_ASSERT(registers.size() == kMaxBuiltinRegisterParams);
+  return registers;
+}
+
+// static
+constexpr auto RecordWriteDescriptor::registers() {
+  return RegisterArray(a0, a1, a2, a3, kReturnRegister0);
+}
+
+// static
+constexpr auto DynamicCheckMapsDescriptor::registers() {
+  return RegisterArray(kReturnRegister0, a0, a1, a2, cp);
+}
+
+// static
+constexpr auto EphemeronKeyBarrierDescriptor::registers() {
+  return RegisterArray(a0, a1, a2, a3, kReturnRegister0);
+}
+
+// static
+constexpr Register LoadDescriptor::ReceiverRegister() { return a1; }
+// static
+constexpr Register LoadDescriptor::NameRegister() { return a2; }
+// static
+constexpr Register LoadDescriptor::SlotRegister() { return a0; }
+
+// static
+constexpr Register LoadWithVectorDescriptor::VectorRegister() { return a3; }
+
+// static
+constexpr Register
+LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
+  return a4;
+}
+
+// static
+constexpr Register StoreDescriptor::ReceiverRegister() { return a1; }
+// static
+constexpr Register StoreDescriptor::NameRegister() { return a2; }
+// static
+constexpr Register StoreDescriptor::ValueRegister() { return a0; }
+// static
+constexpr Register StoreDescriptor::SlotRegister() { return a4; }
+
+// static
+constexpr Register StoreWithVectorDescriptor::VectorRegister() { return a3; }
+
+// static
+constexpr Register StoreTransitionDescriptor::MapRegister() { return a5; }
+
+// static
+constexpr Register ApiGetterDescriptor::HolderRegister() { return a0; }
+// static
+constexpr Register ApiGetterDescriptor::CallbackRegister() { return a3; }
+
+// static
+constexpr Register GrowArrayElementsDescriptor::ObjectRegister() { return a0; }
+// static
+constexpr Register GrowArrayElementsDescriptor::KeyRegister() { return a3; }
+
+// static
+constexpr Register BaselineLeaveFrameDescriptor::ParamsSizeRegister() {
+  // TODO(v8:11421): Implement on this platform.
+  return a3;
+}
+
+// static
+constexpr Register BaselineLeaveFrameDescriptor::WeightRegister() {
+  // TODO(v8:11421): Implement on this platform.
+  return a4;
+}
+
+// static
+constexpr Register TypeConversionDescriptor::ArgumentRegister() { return a0; }
+
+// static
+constexpr auto TypeofDescriptor::registers() { return RegisterArray(a3); }
+
+// static
+constexpr auto CallTrampolineDescriptor::registers() {
+  // a1: target
+  // a0: number of arguments
+  return RegisterArray(a1, a0);
+}
+
+// static
+constexpr auto CallVarargsDescriptor::registers() {
+  // a0 : number of arguments (on the stack, not including receiver)
+  // a1 : the target to call
+  // a4 : arguments list length (untagged)
+  // a2 : arguments list (FixedArray)
+  return RegisterArray(a1, a0, a4, a2);
+}
+
+// static
+constexpr auto CallForwardVarargsDescriptor::registers() {
+  // a1: the target to call
+  // a0: number of arguments
+  // a2: start index (to support rest parameters)
+  return RegisterArray(a1, a0, a2);
+}
+
+// static
+constexpr auto CallFunctionTemplateDescriptor::registers() {
+  // a1 : function template info
+  // a0 : number of arguments (on the stack, not including receiver)
+  return RegisterArray(a1, a0);
+}
+
+// static
+constexpr auto CallWithSpreadDescriptor::registers() {
+  // a0 : number of arguments (on the stack, not including receiver)
+  // a1 : the target to call
+  // a2 : the object to spread
+  return RegisterArray(a1, a0, a2);
+}
+
+// static
+constexpr auto CallWithArrayLikeDescriptor::registers() {
+  // a1 : the target to call
+  // a2 : the arguments list
+  return RegisterArray(a1, a2);
+}
+
+// static
+constexpr auto ConstructVarargsDescriptor::registers() {
+  // a0 : number of arguments (on the stack, not including receiver)
+  // a1 : the target to call
+  // a3 : the new target
+  // a4 : arguments list length (untagged)
+  // a2 : arguments list (FixedArray)
+  return RegisterArray(a1, a3, a0, a4, a2);
+}
+
+// static
+constexpr auto ConstructForwardVarargsDescriptor::registers() {
+  // a1: the target to call
+  // a3: new target
+  // a0: number of arguments
+  // a2: start index (to support rest parameters)
+  return RegisterArray(a1, a3, a0, a2);
+}
+
+// static
+constexpr auto ConstructWithSpreadDescriptor::registers() {
+  // a0 : number of arguments (on the stack, not including receiver)
+  // a1 : the target to call
+  // a3 : the new target
+  // a2 : the object to spread
+  return RegisterArray(a1, a3, a0, a2);
+}
+
+// static
+constexpr auto ConstructWithArrayLikeDescriptor::registers() {
+  // a1 : the target to call
+  // a3 : the new target
+  // a2 : the arguments list
+  return RegisterArray(a1, a3, a2);
+}
+
+// static
+constexpr auto ConstructStubDescriptor::registers() {
+  // a1: target
+  // a3: new target
+  // a0: number of arguments
+  // a2: allocation site or undefined
+  return RegisterArray(a1, a3, a0, a2);
+}
+
+// static
+constexpr auto AbortDescriptor::registers() { return RegisterArray(a0); }
+
+// static
+constexpr auto CompareDescriptor::registers() { return RegisterArray(a1, a0); }
+
+// static
+constexpr auto Compare_BaselineDescriptor::registers() {
+  // TODO(v8:11421): Implement on this platform.
+  return RegisterArray(a1, a0, a2);
+}
+
+// static
+constexpr auto BinaryOpDescriptor::registers() { return RegisterArray(a1, a0); }
+
+// static
+constexpr auto BinaryOp_BaselineDescriptor::registers() {
+  return RegisterArray(a1, a0, a2);
+}
+
+// static
+constexpr auto ApiCallbackDescriptor::registers() {
+  // a1 : kApiFunctionAddress
+  // a2 : kArgc
+  // a3 : kCallData
+  // a0 : kHolder
+  return RegisterArray(a1, a2, a3, a0);
+}
+
+// static
+constexpr auto InterpreterDispatchDescriptor::registers() {
+  return RegisterArray(
+      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
+      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister);
+}
+
+// static
+constexpr auto InterpreterPushArgsThenCallDescriptor::registers() {
+  // a0 : argument count (not including receiver)
+  // a2 : address of first argument
+  // a1 : the target callable to be call
+  return RegisterArray(a0, a2, a1);
+}
+
+// static
+constexpr auto InterpreterPushArgsThenConstructDescriptor::registers() {
+  // a0 : argument count (not including receiver)
+  // a4 : address of the first argument
+  // a1 : constructor to call
+  // a3 : new target
+  // a2 : allocation site feedback if available, undefined otherwise
+  return RegisterArray(a0, a4, a1, a3, a2);
+}
+
+// static
+constexpr auto ResumeGeneratorDescriptor::registers() {
+  // v0 : the value to pass to the generator
+  // a1 : the JSGeneratorObject to resume
+  return RegisterArray(v0, a1);
+}
+
+// static
+constexpr auto RunMicrotasksEntryDescriptor::registers() {
+  return RegisterArray(a0, a1);
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TARGET_ARCH_MIPS64
+
+#endif  // V8_CODEGEN_MIPS64_INTERFACE_DESCRIPTORS_MIPS64_INL_H_
diff --git a/chromium/v8/src/codegen/mips64/interface-descriptors-mips64.cc b/chromium/v8/src/codegen/mips64/interface-descriptors-mips64.cc
deleted file mode 100644
index f34d16e15b7..00000000000
--- a/chromium/v8/src/codegen/mips64/interface-descriptors-mips64.cc
+++ /dev/null
@@ -1,332 +0,0 @@
-// Copyright 2012 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#if V8_TARGET_ARCH_MIPS64
-
-#include "src/codegen/interface-descriptors.h"
-
-#include "src/execution/frames.h"
-
-namespace v8 {
-namespace internal {
-
-const Register CallInterfaceDescriptor::ContextRegister() { return cp; }
-
-void CallInterfaceDescriptor::DefaultInitializePlatformSpecific(
-    CallInterfaceDescriptorData* data, int register_parameter_count) {
-  const Register default_stub_registers[] = {a0, a1, a2, a3, a4};
-  CHECK_LE(static_cast<size_t>(register_parameter_count),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(register_parameter_count,
-                                   default_stub_registers);
-}
-
-// On MIPS it is not allowed to use odd numbered floating point registers
-// (e.g. f1, f3, etc.) for parameters. This can happen if we use
-// DefaultInitializePlatformSpecific to assign float registers for parameters.
-// E.g if fourth parameter goes to float register, f7 would be assigned for
-// parameter (a3 casted to int is 7).
-bool CallInterfaceDescriptor::IsValidFloatParameterRegister(Register reg) {
-  return reg.code() % 2 == 0;
-}
-
-void WasmI32AtomicWait32Descriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {a0, a1, a2, a3};
-  CHECK_EQ(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void WasmI64AtomicWait32Descriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {a0, a1, a2, a3, a4};
-  CHECK_EQ(static_cast<size_t>(kParameterCount - kStackArgumentsCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount - kStackArgumentsCount,
-                                   default_stub_registers);
-}
-
-void RecordWriteDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {a0, a1, a2, a3, kReturnRegister0};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void DynamicCheckMapsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register default_stub_registers[] = {kReturnRegister0, a0, a1, a2, cp};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void EphemeronKeyBarrierDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {a0, a1, a2, a3, kReturnRegister0};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-const Register LoadDescriptor::ReceiverRegister() { return a1; }
-const Register LoadDescriptor::NameRegister() { return a2; }
-const Register LoadDescriptor::SlotRegister() { return a0; }
-
-const Register LoadWithVectorDescriptor::VectorRegister() { return a3; }
-
-const Register
-LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
-  return a4;
-}
-
-const Register StoreDescriptor::ReceiverRegister() { return a1; }
-const Register StoreDescriptor::NameRegister() { return a2; }
-const Register StoreDescriptor::ValueRegister() { return a0; }
-const Register StoreDescriptor::SlotRegister() { return a4; }
-
-const Register StoreWithVectorDescriptor::VectorRegister() { return a3; }
-
-const Register StoreTransitionDescriptor::SlotRegister() { return a4; }
-const Register StoreTransitionDescriptor::VectorRegister() { return a3; }
-const Register StoreTransitionDescriptor::MapRegister() { return a5; }
-
-const Register ApiGetterDescriptor::HolderRegister() { return a0; }
-const Register ApiGetterDescriptor::CallbackRegister() { return a3; }
-
-const Register GrowArrayElementsDescriptor::ObjectRegister() { return a0; }
-const Register GrowArrayElementsDescriptor::KeyRegister() { return a3; }
-
-const Register BaselineLeaveFrameDescriptor::ParamsSizeRegister() {
-  // TODO(v8:11421): Implement on this platform.
-  UNREACHABLE();
-}
-const Register BaselineLeaveFrameDescriptor::WeightRegister() {
-  // TODO(v8:11421): Implement on this platform.
-  UNREACHABLE();
-}
-
-// static
-const Register TypeConversionDescriptor::ArgumentRegister() { return a0; }
-
-void TypeofDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {a3};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1: target
-  // a0: number of arguments
-  Register registers[] = {a1, a0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a0 : number of arguments (on the stack, not including receiver)
-  // a1 : the target to call
-  // a4 : arguments list length (untagged)
-  // a2 : arguments list (FixedArray)
-  Register registers[] = {a1, a0, a4, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1: the target to call
-  // a0: number of arguments
-  // a2: start index (to support rest parameters)
-  Register registers[] = {a1, a0, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallFunctionTemplateDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1 : function template info
-  // a0 : number of arguments (on the stack, not including receiver)
-  Register registers[] = {a1, a0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a0 : number of arguments (on the stack, not including receiver)
-  // a1 : the target to call
-  // a2 : the object to spread
-  Register registers[] = {a1, a0, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1 : the target to call
-  // a2 : the arguments list
-  Register registers[] = {a1, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a0 : number of arguments (on the stack, not including receiver)
-  // a1 : the target to call
-  // a3 : the new target
-  // a4 : arguments list length (untagged)
-  // a2 : arguments list (FixedArray)
-  Register registers[] = {a1, a3, a0, a4, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1: the target to call
-  // a3: new target
-  // a0: number of arguments
-  // a2: start index (to support rest parameters)
-  Register registers[] = {a1, a3, a0, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a0 : number of arguments (on the stack, not including receiver)
-  // a1 : the target to call
-  // a3 : the new target
-  // a2 : the object to spread
-  Register registers[] = {a1, a3, a0, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1 : the target to call
-  // a3 : the new target
-  // a2 : the arguments list
-  Register registers[] = {a1, a3, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructStubDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1: target
-  // a3: new target
-  // a0: number of arguments
-  // a2: allocation site or undefined
-  Register registers[] = {a1, a3, a0, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void AbortDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {a0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CompareDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {a1, a0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void Compare_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // TODO(v8:11421): Implement on this platform.
-  InitializePlatformUnimplemented(data, kParameterCount);
-}
-
-void BinaryOpDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {a1, a0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void BinaryOp_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // TODO(v8:11421): Implement on this platform.
-  InitializePlatformUnimplemented(data, kParameterCount);
-}
-
-void ApiCallbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      a1,  // kApiFunctionAddress
-      a2,  // kArgc
-      a3,  // kCallData
-      a0,  // kHolder
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterDispatchDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
-      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenCallDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      a0,  // argument count (not including receiver)
-      a2,  // address of first argument
-      a1   // the target callable to be call
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenConstructDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      a0,  // argument count (not including receiver)
-      a4,  // address of the first argument
-      a1,  // constructor to call
-      a3,  // new target
-      a2,  // allocation site feedback if available, undefined otherwise
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ResumeGeneratorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      v0,  // the value to pass to the generator
-      a1   // the JSGeneratorObject to resume
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void FrameDropperTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      a1,  // loaded new FP
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void RunMicrotasksEntryDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {a0, a1};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_TARGET_ARCH_MIPS64
diff --git a/chromium/v8/src/codegen/mips64/macro-assembler-mips64.cc b/chromium/v8/src/codegen/mips64/macro-assembler-mips64.cc
index 29443a2e58d..a1896624e53 100644
--- a/chromium/v8/src/codegen/mips64/macro-assembler-mips64.cc
+++ b/chromium/v8/src/codegen/mips64/macro-assembler-mips64.cc
@@ -12,6 +12,7 @@
 #include "src/codegen/callable.h"
 #include "src/codegen/code-factory.h"
 #include "src/codegen/external-reference-table.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/macro-assembler.h"
 #include "src/codegen/register-configuration.h"
 #include "src/debug/debug.h"
@@ -64,7 +65,7 @@ int TurboAssembler::RequiredStackSizeForCallerSaved(SaveFPRegsMode fp_mode,
   RegList list = kJSCallerSaved & ~exclusions;
   bytes += NumRegs(list) * kPointerSize;
 
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     bytes += NumRegs(kCallerSavedFPU) * kDoubleSize;
   }
 
@@ -89,7 +90,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
   MultiPush(list);
   bytes += NumRegs(list) * kPointerSize;
 
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     MultiPushFPU(kCallerSavedFPU);
     bytes += NumRegs(kCallerSavedFPU) * kDoubleSize;
   }
@@ -100,7 +101,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
 int TurboAssembler::PopCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
                                    Register exclusion2, Register exclusion3) {
   int bytes = 0;
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     MultiPopFPU(kCallerSavedFPU);
     bytes += NumRegs(kCallerSavedFPU) * kDoubleSize;
   }
@@ -177,7 +178,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   Label done;
 
   // Skip barrier if writing a smi.
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     JumpIfSmi(value, &done);
   }
 
@@ -186,7 +187,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   DCHECK(IsAligned(offset, kPointerSize));
 
   Daddu(dst, object, Operand(offset - kHeapObjectTag));
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     BlockTrampolinePoolScope block_trampoline_pool(this);
     Label ok;
     And(t8, dst, Operand(kPointerSize - 1));
@@ -196,13 +197,13 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   }
 
   RecordWrite(object, dst, value, ra_status, save_fp, remembered_set_action,
-              OMIT_SMI_CHECK);
+              SmiCheck::kOmit);
 
   bind(&done);
 
   // Clobber clobbered input registers when running with the debug-code flag
   // turned on to provoke errors.
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     li(value, Operand(bit_cast<int64_t>(kZapValue + 4)));
     li(dst, Operand(bit_cast<int64_t>(kZapValue + 8)));
   }
@@ -334,7 +335,7 @@ void MacroAssembler::RecordWrite(Register object, Register address,
   DCHECK(!AreAliased(object, address, value, t8));
   DCHECK(!AreAliased(object, address, value, t9));
 
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     UseScratchRegisterScope temps(this);
     Register scratch = temps.Acquire();
     Ld(scratch, MemOperand(address));
@@ -342,7 +343,7 @@ void MacroAssembler::RecordWrite(Register object, Register address,
            Operand(value));
   }
 
-  if ((remembered_set_action == OMIT_REMEMBERED_SET &&
+  if ((remembered_set_action == RememberedSetAction::kOmit &&
        !FLAG_incremental_marking) ||
       FLAG_disable_write_barriers) {
     return;
@@ -352,7 +353,7 @@ void MacroAssembler::RecordWrite(Register object, Register address,
   // catch stores of smis and stores into the young generation.
   Label done;
 
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     DCHECK_EQ(0, kSmiTag);
     JumpIfSmi(value, &done);
   }
@@ -377,7 +378,7 @@ void MacroAssembler::RecordWrite(Register object, Register address,
 
   // Clobber clobbered registers when running with the debug-code flag
   // turned on to provoke errors.
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     li(address, Operand(bit_cast<int64_t>(kZapValue + 12)));
     li(value, Operand(bit_cast<int64_t>(kZapValue + 16)));
   }
@@ -4687,14 +4688,6 @@ void TurboAssembler::PushArray(Register array, Register size, Register scratch,
   }
 }
 
-void MacroAssembler::MaybeDropFrames() {
-  // Check whether we need to drop frames to restart a function on the stack.
-  li(a1, ExternalReference::debug_restart_fp_address(isolate()));
-  Ld(a1, MemOperand(a1));
-  Jump(BUILTIN_CODE(isolate(), FrameDropperTrampoline), RelocInfo::CODE_TARGET,
-       ne, a1, Operand(zero_reg));
-}
-
 // ---------------------------------------------------------------------------
 // Exception handling.
 
@@ -4887,7 +4880,7 @@ void MacroAssembler::StackOverflowCheck(Register num_args, Register scratch1,
 
 void MacroAssembler::InvokePrologue(Register expected_parameter_count,
                                     Register actual_parameter_count,
-                                    Label* done, InvokeFlag flag) {
+                                    Label* done, InvokeType type) {
   Label regular_invoke;
 
   //  a0: actual arguments count
@@ -4999,9 +4992,9 @@ void MacroAssembler::CheckDebugHook(Register fun, Register new_target,
 void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
                                         Register expected_parameter_count,
                                         Register actual_parameter_count,
-                                        InvokeFlag flag) {
+                                        InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
   DCHECK_EQ(function, a1);
   DCHECK_IMPLIES(new_target.is_valid(), new_target == a3);
 
@@ -5015,19 +5008,21 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
   }
 
   Label done;
-  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, flag);
+  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, type);
   // We call indirectly through the code field in the function to
   // allow recompilation to take effect without changing any of the
   // call sites.
   Register code = kJavaScriptCallCodeStartRegister;
   Ld(code, FieldMemOperand(function, JSFunction::kCodeOffset));
-  if (flag == CALL_FUNCTION) {
-    Daddu(code, code, Operand(Code::kHeaderSize - kHeapObjectTag));
-    Call(code);
-  } else {
-    DCHECK(flag == JUMP_FUNCTION);
-    Daddu(code, code, Operand(Code::kHeaderSize - kHeapObjectTag));
-    Jump(code);
+  switch (type) {
+    case InvokeType::kCall:
+      Daddu(code, code, Operand(Code::kHeaderSize - kHeapObjectTag));
+      Call(code);
+      break;
+    case InvokeType::kJump:
+      Daddu(code, code, Operand(Code::kHeaderSize - kHeapObjectTag));
+      Jump(code);
+      break;
   }
 
   // Continue here if InvokePrologue does handle the invocation due to
@@ -5037,9 +5032,9 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
 
 void MacroAssembler::InvokeFunctionWithNewTarget(
     Register function, Register new_target, Register actual_parameter_count,
-    InvokeFlag flag) {
+    InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
 
   // Contract with called JS functions requires that function is passed in a1.
   DCHECK_EQ(function, a1);
@@ -5053,15 +5048,15 @@ void MacroAssembler::InvokeFunctionWithNewTarget(
                       SharedFunctionInfo::kFormalParameterCountOffset));
 
   InvokeFunctionCode(a1, new_target, expected_parameter_count,
-                     actual_parameter_count, flag);
+                     actual_parameter_count, type);
 }
 
 void MacroAssembler::InvokeFunction(Register function,
                                     Register expected_parameter_count,
                                     Register actual_parameter_count,
-                                    InvokeFlag flag) {
+                                    InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
 
   // Contract with called JS functions requires that function is passed in a1.
   DCHECK_EQ(function, a1);
@@ -5070,7 +5065,7 @@ void MacroAssembler::InvokeFunction(Register function,
   Ld(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
 
   InvokeFunctionCode(a1, no_reg, expected_parameter_count,
-                     actual_parameter_count, flag);
+                     actual_parameter_count, type);
 }
 
 // ---------------------------------------------------------------------------
@@ -5214,8 +5209,8 @@ void MacroAssembler::JumpToExternalReference(const ExternalReference& builtin,
                                              BranchDelaySlot bd,
                                              bool builtin_exit_frame) {
   PrepareCEntryFunction(builtin);
-  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, kDontSaveFPRegs,
-                                          kArgvOnStack, builtin_exit_frame);
+  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, SaveFPRegsMode::kIgnore,
+                                          ArgvMode::kStack, builtin_exit_frame);
   Jump(code, RelocInfo::CODE_TARGET, al, zero_reg, Operand(zero_reg), bd);
 }
 
@@ -5267,7 +5262,7 @@ void TurboAssembler::DebugBreak() { stop(); }
 
 void TurboAssembler::Assert(Condition cc, AbortReason reason, Register rs,
                             Operand rt) {
-  if (emit_debug_code()) Check(cc, reason, rs, rt);
+  if (FLAG_debug_code) Check(cc, reason, rs, rt);
 }
 
 void TurboAssembler::Check(Condition cc, AbortReason reason, Register rs,
@@ -5282,11 +5277,11 @@ void TurboAssembler::Check(Condition cc, AbortReason reason, Register rs,
 void TurboAssembler::Abort(AbortReason reason) {
   Label abort_start;
   bind(&abort_start);
-#ifdef DEBUG
-  const char* msg = GetAbortReason(reason);
-  RecordComment("Abort message: ");
-  RecordComment(msg);
-#endif
+  if (FLAG_code_comments) {
+    const char* msg = GetAbortReason(reason);
+    RecordComment("Abort message: ");
+    RecordComment(msg);
+  }
 
   // Avoid emitting call to builtin if requested.
   if (trap_on_abort()) {
@@ -5405,7 +5400,7 @@ void MacroAssembler::EnterExitFrame(bool save_doubles, int stack_space,
   // Set up new frame pointer.
   daddiu(fp, sp, ExitFrameConstants::kFixedFrameSizeFromFp);
 
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Sd(zero_reg, MemOperand(fp, ExitFrameConstants::kSPOffset));
   }
 
@@ -5521,7 +5516,7 @@ int TurboAssembler::ActivationFrameAlignment() {
 }
 
 void MacroAssembler::AssertStackIsAligned() {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     const int frame_alignment = ActivationFrameAlignment();
     const int frame_alignment_mask = frame_alignment - 1;
 
@@ -5566,7 +5561,7 @@ void MacroAssembler::JumpIfNotSmi(Register value, Label* not_smi_label,
 }
 
 void MacroAssembler::AssertNotSmi(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     UseScratchRegisterScope temps(this);
     Register scratch = temps.Acquire();
@@ -5576,7 +5571,7 @@ void MacroAssembler::AssertNotSmi(Register object) {
 }
 
 void MacroAssembler::AssertSmi(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     UseScratchRegisterScope temps(this);
     Register scratch = temps.Acquire();
@@ -5586,7 +5581,7 @@ void MacroAssembler::AssertSmi(Register object) {
 }
 
 void MacroAssembler::AssertConstructor(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     BlockTrampolinePoolScope block_trampoline_pool(this);
     STATIC_ASSERT(kSmiTag == 0);
     SmiTst(object, t8);
@@ -5601,7 +5596,7 @@ void MacroAssembler::AssertConstructor(Register object) {
 }
 
 void MacroAssembler::AssertFunction(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     BlockTrampolinePoolScope block_trampoline_pool(this);
     STATIC_ASSERT(kSmiTag == 0);
     SmiTst(object, t8);
@@ -5617,7 +5612,7 @@ void MacroAssembler::AssertFunction(Register object) {
 }
 
 void MacroAssembler::AssertBoundFunction(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     BlockTrampolinePoolScope block_trampoline_pool(this);
     STATIC_ASSERT(kSmiTag == 0);
     SmiTst(object, t8);
@@ -5630,7 +5625,7 @@ void MacroAssembler::AssertBoundFunction(Register object) {
 }
 
 void MacroAssembler::AssertGeneratorObject(Register object) {
-  if (!emit_debug_code()) return;
+  if (!FLAG_debug_code) return;
   BlockTrampolinePoolScope block_trampoline_pool(this);
   STATIC_ASSERT(kSmiTag == 0);
   SmiTst(object, t8);
@@ -5657,7 +5652,7 @@ void MacroAssembler::AssertGeneratorObject(Register object) {
 
 void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
                                                      Register scratch) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label done_checking;
     AssertNotSmi(object);
     LoadRoot(scratch, RootIndex::kUndefinedValue);
@@ -5949,7 +5944,7 @@ void TurboAssembler::CallCFunctionHelper(Register function,
   // PrepareCallCFunction. The C function must be called via t9, for mips ABI.
 
 #if V8_HOST_ARCH_MIPS || V8_HOST_ARCH_MIPS64
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     int frame_alignment = base::OS::ActivationFrameAlignment();
     int frame_alignment_mask = frame_alignment - 1;
     if (frame_alignment > kPointerSize) {
diff --git a/chromium/v8/src/codegen/mips64/macro-assembler-mips64.h b/chromium/v8/src/codegen/mips64/macro-assembler-mips64.h
index 756b594edb7..054f3345d1b 100644
--- a/chromium/v8/src/codegen/mips64/macro-assembler-mips64.h
+++ b/chromium/v8/src/codegen/mips64/macro-assembler-mips64.h
@@ -55,8 +55,6 @@ enum LiFlags {
   ADDRESS_LOAD = 2
 };
 
-enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
-enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
 enum RAStatus { kRAHasNotBeenSaved, kRAHasBeenSaved };
 
 Register GetRegisterThatIsNotOneOf(Register reg1, Register reg2 = no_reg,
@@ -994,8 +992,8 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   void RecordWriteField(
       Register object, int offset, Register value, Register scratch,
       RAStatus ra_status, SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
   // For a given |object| notify the garbage collector that the slot |address|
   // has been written.  |value| is the object being stored. The value and
@@ -1003,8 +1001,8 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   void RecordWrite(
       Register object, Register address, Register value, RAStatus ra_status,
       SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
   void Pref(int32_t hint, const MemOperand& rs);
 
@@ -1072,7 +1070,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // Invoke the JavaScript function code by either calling or jumping.
   void InvokeFunctionCode(Register function, Register new_target,
                           Register expected_parameter_count,
-                          Register actual_parameter_count, InvokeFlag flag);
+                          Register actual_parameter_count, InvokeType type);
 
   // On function call, call into the debugger if necessary.
   void CheckDebugHook(Register fun, Register new_target,
@@ -1083,12 +1081,9 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // current context to the context in the function before invoking.
   void InvokeFunctionWithNewTarget(Register function, Register new_target,
                                    Register actual_parameter_count,
-                                   InvokeFlag flag);
+                                   InvokeType type);
   void InvokeFunction(Register function, Register expected_parameter_count,
-                      Register actual_parameter_count, InvokeFlag flag);
-
-  // Frame restart support.
-  void MaybeDropFrames();
+                      Register actual_parameter_count, InvokeType type);
 
   // Exception handling.
 
@@ -1112,18 +1107,18 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
 
   // Call a runtime routine.
   void CallRuntime(const Runtime::Function* f, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs);
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore);
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId fid,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     const Runtime::Function* function = Runtime::FunctionForId(fid);
     CallRuntime(function, function->nargs, save_doubles);
   }
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId fid, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     CallRuntime(Runtime::FunctionForId(fid), num_arguments, save_doubles);
   }
 
@@ -1230,7 +1225,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // Helper functions for generating invokes.
   void InvokePrologue(Register expected_parameter_count,
                       Register actual_parameter_count, Label* done,
-                      InvokeFlag flag);
+                      InvokeType type);
 
   // Compute memory operands for safepoint stack slots.
   static int SafepointRegisterStackIndex(int reg_code);
diff --git a/chromium/v8/src/codegen/optimized-compilation-info.cc b/chromium/v8/src/codegen/optimized-compilation-info.cc
index f6fd5862fdc..4d5c7a1d574 100644
--- a/chromium/v8/src/codegen/optimized-compilation-info.cc
+++ b/chromium/v8/src/codegen/optimized-compilation-info.cc
@@ -23,12 +23,16 @@ namespace internal {
 
 OptimizedCompilationInfo::OptimizedCompilationInfo(
     Zone* zone, Isolate* isolate, Handle<SharedFunctionInfo> shared,
-    Handle<JSFunction> closure, CodeKind code_kind)
+    Handle<JSFunction> closure, CodeKind code_kind, BytecodeOffset osr_offset,
+    JavaScriptFrame* osr_frame)
     : code_kind_(code_kind),
+      osr_offset_(osr_offset),
+      osr_frame_(osr_frame),
       zone_(zone),
       optimization_id_(isolate->NextOptimizationId()) {
   DCHECK_EQ(*shared, closure->shared());
   DCHECK(shared->is_compiled());
+  DCHECK_IMPLIES(is_osr(), IsOptimizing());
   bytecode_array_ = handle(shared->GetBytecodeArray(isolate), isolate);
   shared_info_ = shared;
   closure_ = closure;
@@ -64,8 +68,6 @@ bool OptimizedCompilationInfo::FlagSetIsValid(Flag flag) const {
   switch (flag) {
     case kPoisonRegisterArguments:
       return untrusted_code_mitigations();
-    case kFunctionContextSpecializing:
-      return !IsNativeContextIndependent();
     default:
       return true;
   }
@@ -86,18 +88,22 @@ bool OptimizedCompilationInfo::FlagGetIsValid(Flag flag) const {
 
 void OptimizedCompilationInfo::ConfigureFlags() {
   if (FLAG_untrusted_code_mitigations) set_untrusted_code_mitigations();
+  if (FLAG_turbo_inline_js_wasm_calls) set_inline_js_wasm_calls();
+
+  if (!is_osr() && (IsTurboprop() || FLAG_concurrent_inlining)) {
+    set_concurrent_inlining();
+  }
 
   switch (code_kind_) {
     case CodeKind::TURBOFAN:
       if (FLAG_function_context_specialization) {
         set_function_context_specializing();
       }
+      if (FLAG_turbo_splitting) set_splitting();
       V8_FALLTHROUGH;
     case CodeKind::TURBOPROP:
-    case CodeKind::NATIVE_CONTEXT_INDEPENDENT:
       set_called_with_code_start_register();
       set_switch_jump_table();
-      if (FLAG_turbo_splitting) set_splitting();
       if (FLAG_untrusted_code_mitigations) set_poison_register_arguments();
       // TODO(yangguo): Disable this in case of debugging for crbug.com/826613
       if (FLAG_analyze_environment_liveness) set_analyze_environment_liveness();
diff --git a/chromium/v8/src/codegen/optimized-compilation-info.h b/chromium/v8/src/codegen/optimized-compilation-info.h
index 20386cbbee0..b5ad1c98162 100644
--- a/chromium/v8/src/codegen/optimized-compilation-info.h
+++ b/chromium/v8/src/codegen/optimized-compilation-info.h
@@ -70,7 +70,9 @@ class V8_EXPORT_PRIVATE OptimizedCompilationInfo final {
   V(TraceTurboAllocation, trace_turbo_allocation, 16)                \
   V(TraceHeapBroker, trace_heap_broker, 17)                          \
   V(WasmRuntimeExceptionSupport, wasm_runtime_exception_support, 18) \
-  V(ConcurrentInlining, concurrent_inlining, 19)
+  V(ConcurrentInlining, concurrent_inlining, 19)                     \
+  V(DiscardResultForTesting, discard_result_for_testing, 20)         \
+  V(InlineJSWasmCalls, inline_js_wasm_calls, 21)
 
   enum Flag {
 #define DEF_ENUM(Camel, Lower, Bit) k##Camel = 1 << Bit,
@@ -102,7 +104,15 @@ class V8_EXPORT_PRIVATE OptimizedCompilationInfo final {
   // Construct a compilation info for optimized compilation.
   OptimizedCompilationInfo(Zone* zone, Isolate* isolate,
                            Handle<SharedFunctionInfo> shared,
-                           Handle<JSFunction> closure, CodeKind code_kind);
+                           Handle<JSFunction> closure, CodeKind code_kind,
+                           BytecodeOffset osr_offset,
+                           JavaScriptFrame* osr_frame);
+  // For testing.
+  OptimizedCompilationInfo(Zone* zone, Isolate* isolate,
+                           Handle<SharedFunctionInfo> shared,
+                           Handle<JSFunction> closure, CodeKind code_kind)
+      : OptimizedCompilationInfo(zone, isolate, shared, closure, code_kind,
+                                 BytecodeOffset::None(), nullptr) {}
   // Construct a compilation info for stub compilation, Wasm, and testing.
   OptimizedCompilationInfo(Vector<const char> debug_name, Zone* zone,
                            CodeKind code_kind);
@@ -160,21 +170,11 @@ class V8_EXPORT_PRIVATE OptimizedCompilationInfo final {
   bool IsOptimizing() const {
     return CodeKindIsOptimizedJSFunction(code_kind());
   }
-  bool IsNativeContextIndependent() const {
-    return code_kind() == CodeKind::NATIVE_CONTEXT_INDEPENDENT;
-  }
   bool IsTurboprop() const { return code_kind() == CodeKind::TURBOPROP; }
 #if V8_ENABLE_WEBASSEMBLY
   bool IsWasm() const { return code_kind() == CodeKind::WASM_FUNCTION; }
 #endif  // V8_ENABLE_WEBASSEMBLY
 
-  void SetOptimizingForOsr(BytecodeOffset osr_offset,
-                           JavaScriptFrame* osr_frame) {
-    DCHECK(IsOptimizing());
-    osr_offset_ = osr_offset;
-    osr_frame_ = osr_frame;
-  }
-
   void set_persistent_handles(
       std::unique_ptr<PersistentHandles> persistent_handles) {
     DCHECK_NULL(ph_);
@@ -293,7 +293,9 @@ class V8_EXPORT_PRIVATE OptimizedCompilationInfo final {
 #endif  // V8_ENABLE_WEBASSEMBLY
 
   // Entry point when compiling for OSR, {BytecodeOffset::None} otherwise.
-  BytecodeOffset osr_offset_ = BytecodeOffset::None();
+  const BytecodeOffset osr_offset_ = BytecodeOffset::None();
+  // The current OSR frame for specialization or {nullptr}.
+  JavaScriptFrame* const osr_frame_ = nullptr;
 
   // The zone from which the compilation pipeline working on this
   // OptimizedCompilationInfo allocates.
@@ -309,9 +311,6 @@ class V8_EXPORT_PRIVATE OptimizedCompilationInfo final {
   const int optimization_id_;
   unsigned inlined_bytecode_size_ = 0;
 
-  // The current OSR frame for specialization or {nullptr}.
-  JavaScriptFrame* osr_frame_ = nullptr;
-
   Vector<const char> debug_name_;
   std::unique_ptr<char[]> trace_turbo_filename_;
 
diff --git a/chromium/v8/src/codegen/ppc/assembler-ppc.cc b/chromium/v8/src/codegen/ppc/assembler-ppc.cc
index 7da9484cce1..437f5f96c61 100644
--- a/chromium/v8/src/codegen/ppc/assembler-ppc.cc
+++ b/chromium/v8/src/codegen/ppc/assembler-ppc.cc
@@ -55,7 +55,11 @@ static unsigned CpuFeaturesImpliedByCompiler() {
 }
 
 bool CpuFeatures::SupportsWasmSimd128() {
+#if V8_ENABLE_WEBASSEMBLY
   return CpuFeatures::IsSupported(SIMD);
+#else
+  return false;
+#endif  // V8_ENABLE_WEBASSEMBLY
 }
 
 void CpuFeatures::ProbeImpl(bool cross_compile) {
@@ -1824,6 +1828,12 @@ void Assembler::lxvd(const Simd128Register rt, const MemOperand& src) {
        TX);
 }
 
+void Assembler::lxvx(const Simd128Register rt, const MemOperand& src) {
+  int TX = 1;
+  emit(LXVX | rt.code() * B21 | src.ra().code() * B16 | src.rb().code() * B11 |
+       TX);
+}
+
 void Assembler::lxsdx(const Simd128Register rt, const MemOperand& src) {
   int TX = 1;
   emit(LXSDX | rt.code() * B21 | src.ra().code() * B16 | src.rb().code() * B11 |
@@ -1878,18 +1888,18 @@ void Assembler::stxvd(const Simd128Register rt, const MemOperand& dst) {
        SX);
 }
 
+void Assembler::stxvx(const Simd128Register rt, const MemOperand& dst) {
+  int SX = 1;
+  emit(STXVX | rt.code() * B21 | dst.ra().code() * B16 | dst.rb().code() * B11 |
+       SX);
+}
+
 void Assembler::xxspltib(const Simd128Register rt, const Operand& imm) {
   int TX = 1;
   CHECK(is_uint8(imm.immediate()));
   emit(XXSPLTIB | rt.code() * B21 | imm.immediate() * B11 | TX);
 }
 
-void Assembler::xxbrq(const Simd128Register rt, const Simd128Register rb) {
-  int BX = 1;
-  int TX = 1;
-  emit(XXBRQ | rt.code() * B21 | 31 * B16 | rb.code() * B11 | BX * B1 | TX);
-}
-
 // Pseudo instructions.
 void Assembler::nop(int type) {
   Register reg = r0;
diff --git a/chromium/v8/src/codegen/ppc/assembler-ppc.h b/chromium/v8/src/codegen/ppc/assembler-ppc.h
index d5b37fe59fe..1d7ecf76d7c 100644
--- a/chromium/v8/src/codegen/ppc/assembler-ppc.h
+++ b/chromium/v8/src/codegen/ppc/assembler-ppc.h
@@ -448,6 +448,7 @@ class Assembler : public AssemblerBase {
   }
 
   PPC_XX2_OPCODE_A_FORM_LIST(DECLARE_PPC_XX2_INSTRUCTIONS)
+  PPC_XX2_OPCODE_B_FORM_LIST(DECLARE_PPC_XX2_INSTRUCTIONS)
 #undef DECLARE_PPC_XX2_INSTRUCTIONS
 
 #define DECLARE_PPC_XX3_INSTRUCTIONS(name, instr_name, instr_value)    \
@@ -500,6 +501,9 @@ class Assembler : public AssemblerBase {
   PPC_VX_OPCODE_A_FORM_LIST(DECLARE_PPC_VX_INSTRUCTIONS_A_FORM)
   PPC_VX_OPCODE_B_FORM_LIST(DECLARE_PPC_VX_INSTRUCTIONS_B_FORM)
   PPC_VX_OPCODE_C_FORM_LIST(DECLARE_PPC_VX_INSTRUCTIONS_C_FORM)
+  PPC_VX_OPCODE_D_FORM_LIST(
+      DECLARE_PPC_VX_INSTRUCTIONS_C_FORM) /* OPCODE_D_FORM can use
+                                             INSTRUCTIONS_C_FORM */
 #undef DECLARE_PPC_VX_INSTRUCTIONS_A_FORM
 #undef DECLARE_PPC_VX_INSTRUCTIONS_B_FORM
 #undef DECLARE_PPC_VX_INSTRUCTIONS_C_FORM
@@ -1028,6 +1032,7 @@ class Assembler : public AssemblerBase {
   void mtvsrd(const Simd128Register rt, const Register ra);
   void mtvsrdd(const Simd128Register rt, const Register ra, const Register rb);
   void lxvd(const Simd128Register rt, const MemOperand& src);
+  void lxvx(const Simd128Register rt, const MemOperand& src);
   void lxsdx(const Simd128Register rt, const MemOperand& src);
   void lxsibzx(const Simd128Register rt, const MemOperand& src);
   void lxsihzx(const Simd128Register rt, const MemOperand& src);
@@ -1037,8 +1042,8 @@ class Assembler : public AssemblerBase {
   void stxsihx(const Simd128Register rs, const MemOperand& src);
   void stxsiwx(const Simd128Register rs, const MemOperand& src);
   void stxvd(const Simd128Register rt, const MemOperand& src);
+  void stxvx(const Simd128Register rt, const MemOperand& src);
   void xxspltib(const Simd128Register rt, const Operand& imm);
-  void xxbrq(const Simd128Register rt, const Simd128Register rb);
 
   // Pseudo instructions
 
diff --git a/chromium/v8/src/codegen/ppc/constants-ppc.h b/chromium/v8/src/codegen/ppc/constants-ppc.h
index 5b37a2ee110..56732b7f8b9 100644
--- a/chromium/v8/src/codegen/ppc/constants-ppc.h
+++ b/chromium/v8/src/codegen/ppc/constants-ppc.h
@@ -418,6 +418,10 @@ using Instr = uint32_t;
   /* Saturate */                                                             \
   V(xvcvdpuxws, XVCVDPUXWS, 0xF0000320)
 
+#define PPC_XX2_OPCODE_B_FORM_LIST(V) \
+  /* Vector Byte-Reverse Quadword */  \
+  V(xxbrq, XXBRQ, 0xF01F076C)
+
 #define PPC_XX2_OPCODE_UNUSED_LIST(V)                                        \
   /* VSX Scalar Square Root Double-Precision */                              \
   V(xssqrtdp, XSSQRTDP, 0xF000012C)                                          \
@@ -520,12 +524,11 @@ using Instr = uint32_t;
   /* VSX Vector Test for software Square Root Single-Precision */            \
   V(xvtsqrtsp, XVTSQRTSP, 0xF00002A8)                                        \
   /* Vector Splat Immediate Byte */                                          \
-  V(xxspltib, XXSPLTIB, 0xF00002D0)                                          \
-  /* Vector Byte-Reverse Quadword */                                         \
-  V(xxbrq, XXBRQ, 0xF000076C)
+  V(xxspltib, XXSPLTIB, 0xF00002D0)
 
 #define PPC_XX2_OPCODE_LIST(V)  \
   PPC_XX2_OPCODE_A_FORM_LIST(V) \
+  PPC_XX2_OPCODE_B_FORM_LIST(V) \
   PPC_XX2_OPCODE_UNUSED_LIST(V)
 
 #define PPC_EVX_OPCODE_LIST(V)                                                \
@@ -1983,6 +1986,8 @@ using Instr = uint32_t;
   V(lxsspx, LXSSPX, 0x7C000418)                            \
   /* Load VSR Vector Doubleword*2 Indexed */               \
   V(lxvd, LXVD, 0x7C000698)                                \
+  /* Load VSX Vector Indexed */                            \
+  V(lxvx, LXVX, 0x7C000218)                                \
   /* Load VSR Vector Doubleword & Splat Indexed */         \
   V(lxvdsx, LXVDSX, 0x7C000298)                            \
   /* Load VSR Vector Word*4 Indexed */                     \
@@ -2011,6 +2016,8 @@ using Instr = uint32_t;
   V(stxsspx, STXSSPX, 0x7C000518)                          \
   /* Store VSR Vector Doubleword*2 Indexed */              \
   V(stxvd, STXVD, 0x7C000798)                              \
+  /* Store VSX Vector Indexed */                           \
+  V(stxvx, STXVX, 0x7C000318)                              \
   /* Store VSR Vector Word*4 Indexed */                    \
   V(stxvw, STXVW, 0x7C000718)
 
@@ -2430,6 +2437,12 @@ using Instr = uint32_t;
   /* Vector Population Count Byte */       \
   V(vpopcntb, VPOPCNTB, 0x10000703)
 
+#define PPC_VX_OPCODE_D_FORM_LIST(V) \
+  /* Vector Negate Word */           \
+  V(vnegw, VNEGW, 0x10060602)        \
+  /* Vector Negate Doubleword */     \
+  V(vnegd, VNEGD, 0x10070602)
+
 #define PPC_VX_OPCODE_UNUSED_LIST(V)                                      \
   /* Decimal Add Modulo */                                                \
   V(bcdadd, BCDADD, 0xF0000400)                                           \
@@ -2586,6 +2599,7 @@ using Instr = uint32_t;
   PPC_VX_OPCODE_A_FORM_LIST(V) \
   PPC_VX_OPCODE_B_FORM_LIST(V) \
   PPC_VX_OPCODE_C_FORM_LIST(V) \
+  PPC_VX_OPCODE_D_FORM_LIST(V) \
   PPC_VX_OPCODE_UNUSED_LIST(V)
 
 #define PPC_XS_OPCODE_LIST(V)                      \
@@ -2919,9 +2933,19 @@ class Instruction {
       PPC_VA_OPCODE_LIST(OPCODE_CASES)
       return static_cast<Opcode>(opcode);
     }
+    // Some VX opcodes have integers hard coded in the middle, handle those
+    // first.
+    opcode = extcode | BitField(20, 16) | BitField(10, 0);
+    switch (opcode) {
+      PPC_VX_OPCODE_D_FORM_LIST(OPCODE_CASES)
+      return static_cast<Opcode>(opcode);
+    }
     opcode = extcode | BitField(10, 0);
     switch (opcode) {
-      PPC_VX_OPCODE_LIST(OPCODE_CASES)
+      PPC_VX_OPCODE_A_FORM_LIST(OPCODE_CASES)
+      PPC_VX_OPCODE_B_FORM_LIST(OPCODE_CASES)
+      PPC_VX_OPCODE_C_FORM_LIST(OPCODE_CASES)
+      PPC_VX_OPCODE_UNUSED_LIST(OPCODE_CASES)
       PPC_X_OPCODE_EH_S_FORM_LIST(OPCODE_CASES)
       return static_cast<Opcode>(opcode);
     }
@@ -2935,9 +2959,17 @@ class Instruction {
       PPC_XFX_OPCODE_LIST(OPCODE_CASES)
       return static_cast<Opcode>(opcode);
     }
+    // Some XX2 opcodes have integers hard coded in the middle, handle those
+    // first.
+    opcode = extcode | BitField(20, 16) | BitField(10, 2);
+    switch (opcode) {
+      PPC_XX2_OPCODE_B_FORM_LIST(OPCODE_CASES)
+      return static_cast<Opcode>(opcode);
+    }
     opcode = extcode | BitField(10, 2);
     switch (opcode) {
-      PPC_XX2_OPCODE_LIST(OPCODE_CASES)
+      PPC_XX2_OPCODE_A_FORM_LIST(OPCODE_CASES)
+      PPC_XX2_OPCODE_UNUSED_LIST(OPCODE_CASES)
       return static_cast<Opcode>(opcode);
     }
     opcode = extcode | BitField(10, 1);
diff --git a/chromium/v8/src/codegen/ppc/interface-descriptors-ppc-inl.h b/chromium/v8/src/codegen/ppc/interface-descriptors-ppc-inl.h
new file mode 100644
index 00000000000..69529a3ce68
--- /dev/null
+++ b/chromium/v8/src/codegen/ppc/interface-descriptors-ppc-inl.h
@@ -0,0 +1,256 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_CODEGEN_PPC_INTERFACE_DESCRIPTORS_PPC_INL_H_
+#define V8_CODEGEN_PPC_INTERFACE_DESCRIPTORS_PPC_INL_H_
+
+#if V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
+
+#include "src/codegen/interface-descriptors.h"
+#include "src/execution/frames.h"
+
+namespace v8 {
+namespace internal {
+
+constexpr auto CallInterfaceDescriptor::DefaultRegisterArray() {
+  auto registers = RegisterArray(r3, r4, r5, r6, r7);
+  STATIC_ASSERT(registers.size() == kMaxBuiltinRegisterParams);
+  return registers;
+}
+
+// static
+constexpr auto RecordWriteDescriptor::registers() {
+  return RegisterArray(r3, r4, r5, r6, r7, kReturnRegister0);
+}
+
+// static
+constexpr auto DynamicCheckMapsDescriptor::registers() {
+  return RegisterArray(r3, r4, r5, r6, cp);
+}
+
+// static
+constexpr auto EphemeronKeyBarrierDescriptor::registers() {
+  return RegisterArray(r3, r4, r5, r6, r7, kReturnRegister0);
+}
+
+// static
+constexpr Register LoadDescriptor::ReceiverRegister() { return r4; }
+// static
+constexpr Register LoadDescriptor::NameRegister() { return r5; }
+// static
+constexpr Register LoadDescriptor::SlotRegister() { return r3; }
+
+// static
+constexpr Register LoadWithVectorDescriptor::VectorRegister() { return r6; }
+
+// static
+constexpr Register
+LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
+  return r7;
+}
+
+// static
+constexpr Register StoreDescriptor::ReceiverRegister() { return r4; }
+// static
+constexpr Register StoreDescriptor::NameRegister() { return r5; }
+// static
+constexpr Register StoreDescriptor::ValueRegister() { return r3; }
+// static
+constexpr Register StoreDescriptor::SlotRegister() { return r7; }
+
+// static
+constexpr Register StoreWithVectorDescriptor::VectorRegister() { return r6; }
+
+// static
+constexpr Register StoreTransitionDescriptor::MapRegister() { return r8; }
+
+// static
+constexpr Register ApiGetterDescriptor::HolderRegister() { return r3; }
+// static
+constexpr Register ApiGetterDescriptor::CallbackRegister() { return r6; }
+
+// static
+constexpr Register GrowArrayElementsDescriptor::ObjectRegister() { return r3; }
+// static
+constexpr Register GrowArrayElementsDescriptor::KeyRegister() { return r6; }
+
+// static
+constexpr Register BaselineLeaveFrameDescriptor::ParamsSizeRegister() {
+  // TODO(v8:11421): Implement on this platform.
+  return r6;
+}
+// static
+constexpr Register BaselineLeaveFrameDescriptor::WeightRegister() {
+  // TODO(v8:11421): Implement on this platform.
+  return r7;
+}
+
+// static
+// static
+constexpr Register TypeConversionDescriptor::ArgumentRegister() { return r3; }
+
+// static
+constexpr auto TypeofDescriptor::registers() { return RegisterArray(r6); }
+
+// static
+constexpr auto CallTrampolineDescriptor::registers() {
+  // r3 : number of arguments
+  // r4 : the target to call
+  return RegisterArray(r4, r3);
+}
+
+// static
+constexpr auto CallVarargsDescriptor::registers() {
+  // r3 : number of arguments (on the stack, not including receiver)
+  // r4 : the target to call
+  // r7 : arguments list length (untagged)
+  // r5 : arguments list (FixedArray)
+  return RegisterArray(r4, r3, r7, r5);
+}
+
+// static
+constexpr auto CallForwardVarargsDescriptor::registers() {
+  // r3 : number of arguments
+  // r5 : start index (to support rest parameters)
+  // r4 : the target to call
+  return RegisterArray(r4, r3, r5);
+}
+
+// static
+constexpr auto CallFunctionTemplateDescriptor::registers() {
+  // r4 : function template info
+  // r5 : number of arguments (on the stack, not including receiver)
+  return RegisterArray(r4, r5);
+}
+
+// static
+constexpr auto CallWithSpreadDescriptor::registers() {
+  // r3 : number of arguments (on the stack, not including receiver)
+  // r4 : the target to call
+  // r5 : the object to spread
+  return RegisterArray(r4, r3, r5);
+}
+
+// static
+constexpr auto CallWithArrayLikeDescriptor::registers() {
+  // r4 : the target to call
+  // r5 : the arguments list
+  return RegisterArray(r4, r5);
+}
+
+// static
+constexpr auto ConstructVarargsDescriptor::registers() {
+  // r3 : number of arguments (on the stack, not including receiver)
+  // r4 : the target to call
+  // r6 : the new target
+  // r7 : arguments list length (untagged)
+  // r5 : arguments list (FixedArray)
+  return RegisterArray(r4, r6, r3, r7, r5);
+}
+
+// static
+constexpr auto ConstructForwardVarargsDescriptor::registers() {
+  // r3 : number of arguments
+  // r6 : the new target
+  // r5 : start index (to support rest parameters)
+  // r4 : the target to call
+  return RegisterArray(r4, r6, r3, r5);
+}
+
+// static
+constexpr auto ConstructWithSpreadDescriptor::registers() {
+  // r3 : number of arguments (on the stack, not including receiver)
+  // r4 : the target to call
+  // r6 : the new target
+  // r5 : the object to spread
+  return RegisterArray(r4, r6, r3, r5);
+}
+
+// static
+constexpr auto ConstructWithArrayLikeDescriptor::registers() {
+  // r4 : the target to call
+  // r6 : the new target
+  // r5 : the arguments list
+  return RegisterArray(r4, r6, r5);
+}
+
+// static
+constexpr auto ConstructStubDescriptor::registers() {
+  // r3 : number of arguments
+  // r4 : the target to call
+  // r6 : the new target
+  // r5 : allocation site or undefined
+  return RegisterArray(r4, r6, r3, r5);
+}
+
+// static
+constexpr auto AbortDescriptor::registers() { return RegisterArray(r4); }
+
+// static
+constexpr auto CompareDescriptor::registers() { return RegisterArray(r4, r3); }
+
+// static
+constexpr auto Compare_BaselineDescriptor::registers() {
+  // TODO(v8:11421): Implement on this platform.
+  return DefaultRegisterArray();
+}
+
+// static
+constexpr auto BinaryOpDescriptor::registers() { return RegisterArray(r4, r3); }
+
+// static
+constexpr auto BinaryOp_BaselineDescriptor::registers() {
+  // TODO(v8:11421): Implement on this platform.
+  return DefaultRegisterArray();
+}
+
+// static
+constexpr auto ApiCallbackDescriptor::registers() {
+  return RegisterArray(r4,   // kApiFunctionAddress
+                       r5,   // kArgc
+                       r6,   // kCallData
+                       r3);  // kHolder
+}
+
+// static
+constexpr auto InterpreterDispatchDescriptor::registers() {
+  return RegisterArray(
+      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
+      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister);
+}
+
+// static
+constexpr auto InterpreterPushArgsThenCallDescriptor::registers() {
+  return RegisterArray(r3,   // argument count (not including receiver)
+                       r5,   // address of first argument
+                       r4);  // the target callable to be call
+}
+
+// static
+constexpr auto InterpreterPushArgsThenConstructDescriptor::registers() {
+  return RegisterArray(
+      r3,   // argument count (not including receiver)
+      r7,   // address of the first argument
+      r4,   // constructor to call
+      r6,   // new target
+      r5);  // allocation site feedback if available, undefined otherwise
+}
+
+// static
+constexpr auto ResumeGeneratorDescriptor::registers() {
+  return RegisterArray(r3,   // the value to pass to the generator
+                       r4);  // the JSGeneratorObject to resume
+}
+
+// static
+constexpr auto RunMicrotasksEntryDescriptor::registers() {
+  return RegisterArray(r3, r4);
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
+
+#endif  // V8_CODEGEN_PPC_INTERFACE_DESCRIPTORS_PPC_INL_H_
diff --git a/chromium/v8/src/codegen/ppc/interface-descriptors-ppc.cc b/chromium/v8/src/codegen/ppc/interface-descriptors-ppc.cc
deleted file mode 100644
index ed304e80fc1..00000000000
--- a/chromium/v8/src/codegen/ppc/interface-descriptors-ppc.cc
+++ /dev/null
@@ -1,306 +0,0 @@
-// Copyright 2014 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#if V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
-
-#include "src/codegen/interface-descriptors.h"
-
-#include "src/execution/frames.h"
-
-namespace v8 {
-namespace internal {
-
-const Register CallInterfaceDescriptor::ContextRegister() { return cp; }
-
-void CallInterfaceDescriptor::DefaultInitializePlatformSpecific(
-    CallInterfaceDescriptorData* data, int register_parameter_count) {
-  const Register default_stub_registers[] = {r3, r4, r5, r6, r7};
-  CHECK_LE(static_cast<size_t>(register_parameter_count),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(register_parameter_count,
-                                   default_stub_registers);
-}
-
-void RecordWriteDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {r3, r4, r5, r6, r7};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void DynamicCheckMapsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register default_stub_registers[] = {r3, r4, r5, r6, cp};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void EphemeronKeyBarrierDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {r3, r4, r5, r6, r7};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-const Register LoadDescriptor::ReceiverRegister() { return r4; }
-const Register LoadDescriptor::NameRegister() { return r5; }
-const Register LoadDescriptor::SlotRegister() { return r3; }
-
-const Register LoadWithVectorDescriptor::VectorRegister() { return r6; }
-
-const Register
-LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
-  return r7;
-}
-
-const Register StoreDescriptor::ReceiverRegister() { return r4; }
-const Register StoreDescriptor::NameRegister() { return r5; }
-const Register StoreDescriptor::ValueRegister() { return r3; }
-const Register StoreDescriptor::SlotRegister() { return r7; }
-
-const Register StoreWithVectorDescriptor::VectorRegister() { return r6; }
-
-const Register StoreTransitionDescriptor::SlotRegister() { return r7; }
-const Register StoreTransitionDescriptor::VectorRegister() { return r6; }
-const Register StoreTransitionDescriptor::MapRegister() { return r8; }
-
-const Register ApiGetterDescriptor::HolderRegister() { return r3; }
-const Register ApiGetterDescriptor::CallbackRegister() { return r6; }
-
-const Register GrowArrayElementsDescriptor::ObjectRegister() { return r3; }
-const Register GrowArrayElementsDescriptor::KeyRegister() { return r6; }
-
-const Register BaselineLeaveFrameDescriptor::ParamsSizeRegister() {
-  // TODO(v8:11421): Implement on this platform.
-  UNREACHABLE();
-}
-const Register BaselineLeaveFrameDescriptor::WeightRegister() {
-  // TODO(v8:11421): Implement on this platform.
-  UNREACHABLE();
-}
-
-// static
-const Register TypeConversionDescriptor::ArgumentRegister() { return r3; }
-
-void TypeofDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {r6};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r3 : number of arguments
-  // r4 : the target to call
-  Register registers[] = {r4, r3};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r3 : number of arguments (on the stack, not including receiver)
-  // r4 : the target to call
-  // r7 : arguments list length (untagged)
-  // r5 : arguments list (FixedArray)
-  Register registers[] = {r4, r3, r7, r5};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r3 : number of arguments
-  // r5 : start index (to support rest parameters)
-  // r4 : the target to call
-  Register registers[] = {r4, r3, r5};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallFunctionTemplateDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r4 : function template info
-  // r5 : number of arguments (on the stack, not including receiver)
-  Register registers[] = {r4, r5};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r3 : number of arguments (on the stack, not including receiver)
-  // r4 : the target to call
-  // r5 : the object to spread
-  Register registers[] = {r4, r3, r5};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r4 : the target to call
-  // r5 : the arguments list
-  Register registers[] = {r4, r5};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r3 : number of arguments (on the stack, not including receiver)
-  // r4 : the target to call
-  // r6 : the new target
-  // r7 : arguments list length (untagged)
-  // r5 : arguments list (FixedArray)
-  Register registers[] = {r4, r6, r3, r7, r5};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r3 : number of arguments
-  // r6 : the new target
-  // r5 : start index (to support rest parameters)
-  // r4 : the target to call
-  Register registers[] = {r4, r6, r3, r5};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r3 : number of arguments (on the stack, not including receiver)
-  // r4 : the target to call
-  // r6 : the new target
-  // r5 : the object to spread
-  Register registers[] = {r4, r6, r3, r5};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r4 : the target to call
-  // r6 : the new target
-  // r5 : the arguments list
-  Register registers[] = {r4, r6, r5};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructStubDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r3 : number of arguments
-  // r4 : the target to call
-  // r6 : the new target
-  // r5 : allocation site or undefined
-  Register registers[] = {r4, r6, r3, r5};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void AbortDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {r4};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CompareDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {r4, r3};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void Compare_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // TODO(v8:11421): Implement on this platform.
-  InitializePlatformUnimplemented(data, kParameterCount);
-}
-
-void BinaryOpDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {r4, r3};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void BinaryOp_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // TODO(v8:11421): Implement on this platform.
-  InitializePlatformUnimplemented(data, kParameterCount);
-}
-
-void ApiCallbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      r4,  // kApiFunctionAddress
-      r5,  // kArgc
-      r6,  // kCallData
-      r3,  // kHolder
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterDispatchDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
-      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenCallDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      r3,  // argument count (not including receiver)
-      r5,  // address of first argument
-      r4   // the target callable to be call
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenConstructDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      r3,  // argument count (not including receiver)
-      r7,  // address of the first argument
-      r4,  // constructor to call
-      r6,  // new target
-      r5,  // allocation site feedback if available, undefined otherwise
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ResumeGeneratorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      r3,  // the value to pass to the generator
-      r4   // the JSGeneratorObject to resume
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void FrameDropperTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      r4,  // loaded new FP
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void RunMicrotasksEntryDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {r3, r4};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
diff --git a/chromium/v8/src/codegen/ppc/macro-assembler-ppc.cc b/chromium/v8/src/codegen/ppc/macro-assembler-ppc.cc
index 658a41f381f..e9bce8411f1 100644
--- a/chromium/v8/src/codegen/ppc/macro-assembler-ppc.cc
+++ b/chromium/v8/src/codegen/ppc/macro-assembler-ppc.cc
@@ -12,6 +12,7 @@
 #include "src/codegen/callable.h"
 #include "src/codegen/code-factory.h"
 #include "src/codegen/external-reference-table.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/macro-assembler.h"
 #include "src/codegen/register-configuration.h"
 #include "src/debug/debug.h"
@@ -55,7 +56,7 @@ int TurboAssembler::RequiredStackSizeForCallerSaved(SaveFPRegsMode fp_mode,
   RegList list = kJSCallerSaved & ~exclusions;
   bytes += NumRegs(list) * kSystemPointerSize;
 
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     bytes += kNumCallerSavedDoubles * kDoubleSize;
   }
 
@@ -80,7 +81,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
   MultiPush(list);
   bytes += NumRegs(list) * kSystemPointerSize;
 
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     MultiPushDoubles(kCallerSavedDoubles);
     bytes += kNumCallerSavedDoubles * kDoubleSize;
   }
@@ -91,7 +92,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
 int TurboAssembler::PopCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
                                    Register exclusion2, Register exclusion3) {
   int bytes = 0;
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     MultiPopDoubles(kCallerSavedDoubles);
     bytes += kNumCallerSavedDoubles * kDoubleSize;
   }
@@ -133,7 +134,7 @@ void TurboAssembler::LoadFromConstantsTable(Register destination,
 }
 
 void TurboAssembler::LoadRootRelative(Register destination, int32_t offset) {
-  LoadP(destination, MemOperand(kRootRegister, offset), r0);
+  LoadU64(destination, MemOperand(kRootRegister, offset), r0);
 }
 
 void TurboAssembler::LoadRootRegisterOffset(Register destination,
@@ -184,7 +185,7 @@ void TurboAssembler::Jump(Handle<Code> code, RelocInfo::Mode rmode,
     Register scratch = ip;
     int offset = code->builtin_index() * kSystemPointerSize +
                  IsolateData::builtin_entry_table_offset();
-    LoadP(scratch, MemOperand(kRootRegister, offset), r0);
+    LoadU64(scratch, MemOperand(kRootRegister, offset), r0);
     if (cond != al) b(NegateCondition(cond), &skip, cr);
     Jump(scratch);
     bind(&skip);
@@ -214,9 +215,9 @@ void TurboAssembler::Jump(const ExternalReference& reference) {
   if (ABI_USES_FUNCTION_DESCRIPTORS) {
     // AIX uses a function descriptor. When calling C code be
     // aware of this descriptor and pick up values from it.
-    LoadP(ToRegister(ABI_TOC_REGISTER),
-          MemOperand(scratch, kSystemPointerSize));
-    LoadP(scratch, MemOperand(scratch, 0));
+    LoadU64(ToRegister(ABI_TOC_REGISTER),
+            MemOperand(scratch, kSystemPointerSize));
+    LoadU64(scratch, MemOperand(scratch, 0));
   }
   Jump(scratch);
 }
@@ -272,7 +273,7 @@ void TurboAssembler::Call(Handle<Code> code, RelocInfo::Mode rmode,
     Label skip;
     int offset = code->builtin_index() * kSystemPointerSize +
                  IsolateData::builtin_entry_table_offset();
-    LoadP(ip, MemOperand(kRootRegister, offset));
+    LoadU64(ip, MemOperand(kRootRegister, offset));
     if (cond != al) b(NegateCondition(cond), &skip);
     Call(ip);
     bind(&skip);
@@ -411,7 +412,7 @@ void TurboAssembler::MultiPop(RegList regs, Register location) {
 
   for (int16_t i = 0; i < Register::kNumRegisters; i++) {
     if ((regs & (1 << i)) != 0) {
-      LoadP(ToRegister(i), MemOperand(location, stack_offset));
+      LoadU64(ToRegister(i), MemOperand(location, stack_offset));
       stack_offset += kSystemPointerSize;
     }
   }
@@ -442,7 +443,7 @@ void TurboAssembler::MultiPushV128(RegList dregs, Register location) {
       Simd128Register dreg = Simd128Register::from_code(i);
       stack_offset -= kSimd128Size;
       li(ip, Operand(stack_offset));
-      StoreSimd128(dreg, MemOperand(location, ip), r0, kScratchSimd128Reg);
+      StoreSimd128(dreg, MemOperand(location, ip));
     }
   }
 }
@@ -467,7 +468,7 @@ void TurboAssembler::MultiPopV128(RegList dregs, Register location) {
     if ((dregs & (1 << i)) != 0) {
       Simd128Register dreg = Simd128Register::from_code(i);
       li(ip, Operand(stack_offset));
-      LoadSimd128(dreg, MemOperand(location, ip), r0, kScratchSimd128Reg);
+      LoadSimd128(dreg, MemOperand(location, ip));
       stack_offset += kSimd128Size;
     }
   }
@@ -477,8 +478,8 @@ void TurboAssembler::MultiPopV128(RegList dregs, Register location) {
 void TurboAssembler::LoadRoot(Register destination, RootIndex index,
                               Condition cond) {
   DCHECK(cond == al);
-  LoadP(destination,
-        MemOperand(kRootRegister, RootRegisterOffsetForRootIndex(index)), r0);
+  LoadU64(destination,
+          MemOperand(kRootRegister, RootRegisterOffsetForRootIndex(index)), r0);
 }
 
 void TurboAssembler::LoadTaggedPointerField(const Register& destination,
@@ -487,7 +488,7 @@ void TurboAssembler::LoadTaggedPointerField(const Register& destination,
   if (COMPRESS_POINTERS_BOOL) {
     DecompressTaggedPointer(destination, field_operand);
   } else {
-    LoadP(destination, field_operand, scratch);
+    LoadU64(destination, field_operand, scratch);
   }
 }
 
@@ -497,7 +498,7 @@ void TurboAssembler::LoadAnyTaggedField(const Register& destination,
   if (COMPRESS_POINTERS_BOOL) {
     DecompressAnyTagged(destination, field_operand);
   } else {
-    LoadP(destination, field_operand, scratch);
+    LoadU64(destination, field_operand, scratch);
   }
 }
 
@@ -505,7 +506,7 @@ void TurboAssembler::SmiUntag(Register dst, const MemOperand& src, RCBit rc) {
   if (SmiValuesAre31Bits()) {
     lwz(dst, src);
   } else {
-    LoadP(dst, src);
+    LoadU64(dst, src);
   }
 
   SmiUntag(dst, rc);
@@ -550,7 +551,7 @@ void TurboAssembler::DecompressTaggedSigned(Register destination,
 void TurboAssembler::DecompressTaggedSigned(Register destination,
                                             MemOperand field_operand) {
   RecordComment("[ DecompressTaggedSigned");
-  LoadWord(destination, field_operand, r0);
+  LoadU32(destination, field_operand, r0);
   RecordComment("]");
 }
 
@@ -565,7 +566,7 @@ void TurboAssembler::DecompressTaggedPointer(Register destination,
 void TurboAssembler::DecompressTaggedPointer(Register destination,
                                              MemOperand field_operand) {
   RecordComment("[ DecompressTaggedPointer");
-  LoadWord(destination, field_operand, r0);
+  LoadU32(destination, field_operand, r0);
   add(destination, destination, kRootRegister);
   RecordComment("]");
 }
@@ -573,7 +574,7 @@ void TurboAssembler::DecompressTaggedPointer(Register destination,
 void TurboAssembler::DecompressAnyTagged(Register destination,
                                          MemOperand field_operand) {
   RecordComment("[ DecompressAnyTagged");
-  LoadWord(destination, field_operand, r0);
+  LoadU32(destination, field_operand, r0);
   add(destination, destination, kRootRegister);
   RecordComment("]");
 }
@@ -597,7 +598,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   Label done;
 
   // Skip barrier if writing a smi.
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     JumpIfSmi(value, &done);
   }
 
@@ -606,7 +607,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   DCHECK(IsAligned(offset, kTaggedSize));
 
   Add(dst, object, offset - kHeapObjectTag, r0);
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label ok;
     andi(r0, dst, Operand(kTaggedSize - 1));
     beq(&ok, cr0);
@@ -615,13 +616,13 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   }
 
   RecordWrite(object, dst, value, lr_status, save_fp, remembered_set_action,
-              OMIT_SMI_CHECK);
+              SmiCheck::kOmit);
 
   bind(&done);
 
   // Clobber clobbered input registers when running with the debug-code flag
   // turned on to provoke errors.
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     mov(value, Operand(bit_cast<intptr_t>(kZapValue + 4)));
     mov(dst, Operand(bit_cast<intptr_t>(kZapValue + 8)));
   }
@@ -752,13 +753,13 @@ void MacroAssembler::RecordWrite(Register object, Register address,
                                  RememberedSetAction remembered_set_action,
                                  SmiCheck smi_check) {
   DCHECK(object != value);
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     LoadTaggedPointerField(r0, MemOperand(address));
     cmp(r0, value);
     Check(eq, AbortReason::kWrongAddressOrValuePassedToRecordWrite);
   }
 
-  if ((remembered_set_action == OMIT_REMEMBERED_SET &&
+  if ((remembered_set_action == RememberedSetAction::kOmit &&
        !FLAG_incremental_marking) ||
       FLAG_disable_write_barriers) {
     return;
@@ -768,7 +769,7 @@ void MacroAssembler::RecordWrite(Register object, Register address,
   // catch stores of smis and stores into the young generation.
   Label done;
 
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     JumpIfSmi(value, &done);
   }
 
@@ -794,7 +795,7 @@ void MacroAssembler::RecordWrite(Register object, Register address,
 
   // Clobber clobbered registers when running with the debug-code flag
   // turned on to provoke errors.
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     mov(address, Operand(bit_cast<intptr_t>(kZapValue + 12)));
     mov(value, Operand(bit_cast<intptr_t>(kZapValue + 16)));
   }
@@ -849,12 +850,12 @@ void TurboAssembler::PushStandardFrame(Register function_reg) {
 
 void TurboAssembler::RestoreFrameStateForTailCall() {
   if (FLAG_enable_embedded_constant_pool) {
-    LoadP(kConstantPoolRegister,
-          MemOperand(fp, StandardFrameConstants::kConstantPoolOffset));
+    LoadU64(kConstantPoolRegister,
+            MemOperand(fp, StandardFrameConstants::kConstantPoolOffset));
     set_constant_pool_available(false);
   }
-  LoadP(r0, MemOperand(fp, StandardFrameConstants::kCallerPCOffset));
-  LoadP(fp, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  LoadU64(r0, MemOperand(fp, StandardFrameConstants::kCallerPCOffset));
+  LoadU64(fp, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
   mtlr(r0);
 }
 
@@ -1174,11 +1175,11 @@ int TurboAssembler::LeaveFrame(StackFrame::Type type, int stack_adjustment) {
   // Drop the execution stack down to the frame pointer and restore
   // the caller's state.
   int frame_ends;
-  LoadP(r0, MemOperand(fp, StandardFrameConstants::kCallerPCOffset));
-  LoadP(ip, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  LoadU64(r0, MemOperand(fp, StandardFrameConstants::kCallerPCOffset));
+  LoadU64(ip, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
   if (FLAG_enable_embedded_constant_pool) {
-    LoadP(kConstantPoolRegister,
-          MemOperand(fp, StandardFrameConstants::kConstantPoolOffset));
+    LoadU64(kConstantPoolRegister,
+            MemOperand(fp, StandardFrameConstants::kConstantPoolOffset));
   }
   mtlr(r0);
   frame_ends = pc_offset();
@@ -1221,7 +1222,7 @@ void MacroAssembler::EnterExitFrame(bool save_doubles, int stack_space,
   // Reserve room for saved entry sp.
   subi(sp, fp, Operand(ExitFrameConstants::kFixedFrameSizeFromFp));
 
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     li(r8, Operand::Zero());
     StoreP(r8, MemOperand(fp, ExitFrameConstants::kSPOffset));
   }
@@ -1305,7 +1306,7 @@ void MacroAssembler::LeaveExitFrame(bool save_doubles, Register argument_count,
   // Restore current context from top and clear it in debug mode.
   Move(ip,
        ExternalReference::Create(IsolateAddressId::kContextAddress, isolate()));
-  LoadP(cp, MemOperand(ip));
+  LoadU64(cp, MemOperand(ip));
 
 #ifdef DEBUG
   mov(r6, Operand(Context::kInvalidContext));
@@ -1393,7 +1394,7 @@ void MacroAssembler::LoadStackLimit(Register destination, StackLimitKind kind) {
   intptr_t offset =
       TurboAssembler::RootRegisterOffsetForExternalReference(isolate, limit);
   CHECK(is_int32(offset));
-  LoadP(destination, MemOperand(kRootRegister, offset), r0);
+  LoadU64(destination, MemOperand(kRootRegister, offset), r0);
 }
 
 void MacroAssembler::StackOverflowCheck(Register num_args, Register scratch,
@@ -1413,7 +1414,7 @@ void MacroAssembler::StackOverflowCheck(Register num_args, Register scratch,
 
 void MacroAssembler::InvokePrologue(Register expected_parameter_count,
                                     Register actual_parameter_count,
-                                    Label* done, InvokeFlag flag) {
+                                    Label* done, InvokeType type) {
   Label regular_invoke;
 
   //  r3: actual arguments count
@@ -1528,9 +1529,9 @@ void MacroAssembler::CheckDebugHook(Register fun, Register new_target,
 void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
                                         Register expected_parameter_count,
                                         Register actual_parameter_count,
-                                        InvokeFlag flag) {
+                                        InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
   DCHECK_EQ(function, r4);
   DCHECK_IMPLIES(new_target.is_valid(), new_target == r6);
 
@@ -1544,18 +1545,20 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
   }
 
   Label done;
-  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, flag);
+  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, type);
   // We call indirectly through the code field in the function to
   // allow recompilation to take effect without changing any of the
   // call sites.
   Register code = kJavaScriptCallCodeStartRegister;
   LoadTaggedPointerField(code,
                          FieldMemOperand(function, JSFunction::kCodeOffset));
-  if (flag == CALL_FUNCTION) {
-    CallCodeObject(code);
-  } else {
-    DCHECK(flag == JUMP_FUNCTION);
-    JumpCodeObject(code);
+  switch (type) {
+    case InvokeType::kCall:
+      CallCodeObject(code);
+      break;
+    case InvokeType::kJump:
+      JumpCodeObject(code);
+      break;
   }
 
     // Continue here if InvokePrologue does handle the invocation due to
@@ -1565,9 +1568,9 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
 
 void MacroAssembler::InvokeFunctionWithNewTarget(
     Register fun, Register new_target, Register actual_parameter_count,
-    InvokeFlag flag) {
+    InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
 
   // Contract with called JS functions requires that function is passed in r4.
   DCHECK_EQ(fun, r4);
@@ -1583,15 +1586,15 @@ void MacroAssembler::InvokeFunctionWithNewTarget(
                    temp_reg, SharedFunctionInfo::kFormalParameterCountOffset));
 
   InvokeFunctionCode(fun, new_target, expected_reg, actual_parameter_count,
-                     flag);
+                     type);
 }
 
 void MacroAssembler::InvokeFunction(Register function,
                                     Register expected_parameter_count,
                                     Register actual_parameter_count,
-                                    InvokeFlag flag) {
+                                    InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
 
   // Contract with called JS functions requires that function is passed in r4.
   DCHECK_EQ(function, r4);
@@ -1600,18 +1603,7 @@ void MacroAssembler::InvokeFunction(Register function,
   LoadTaggedPointerField(cp, FieldMemOperand(r4, JSFunction::kContextOffset));
 
   InvokeFunctionCode(r4, no_reg, expected_parameter_count,
-                     actual_parameter_count, flag);
-}
-
-void MacroAssembler::MaybeDropFrames() {
-  // Check whether we need to drop frames to restart a function on the stack.
-  ExternalReference restart_fp =
-      ExternalReference::debug_restart_fp_address(isolate());
-  Move(r4, restart_fp);
-  LoadP(r4, MemOperand(r4));
-  cmpi(r4, Operand::Zero());
-  Jump(BUILTIN_CODE(isolate(), FrameDropperTrampoline), RelocInfo::CODE_TARGET,
-       ne);
+                     actual_parameter_count, type);
 }
 
 void MacroAssembler::PushStackHandler() {
@@ -1625,7 +1617,7 @@ void MacroAssembler::PushStackHandler() {
   // Preserve r4-r8.
   Move(r3,
        ExternalReference::Create(IsolateAddressId::kHandlerAddress, isolate()));
-  LoadP(r0, MemOperand(r3));
+  LoadU64(r0, MemOperand(r3));
   push(r0);
 
   // Set this new handler as the current one.
@@ -1806,7 +1798,7 @@ void TurboAssembler::TruncateDoubleToI(Isolate* isolate, Zone* zone,
     Call(BUILTIN_CODE(isolate, DoubleToI), RelocInfo::CODE_TARGET);
   }
 
-  LoadP(result, MemOperand(sp));
+  LoadU64(result, MemOperand(sp));
   addi(sp, sp, Operand(kDoubleSize));
   pop(r0);
   mtlr(r0);
@@ -1873,8 +1865,8 @@ void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid) {
 void MacroAssembler::JumpToExternalReference(const ExternalReference& builtin,
                                              bool builtin_exit_frame) {
   Move(r4, builtin);
-  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, kDontSaveFPRegs,
-                                          kArgvOnStack, builtin_exit_frame);
+  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, SaveFPRegsMode::kIgnore,
+                                          ArgvMode::kStack, builtin_exit_frame);
   Jump(code, RelocInfo::CODE_TARGET);
 }
 
@@ -1921,7 +1913,7 @@ void MacroAssembler::DecrementCounter(StatsCounter* counter, int value,
 }
 
 void TurboAssembler::Assert(Condition cond, AbortReason reason, CRegister cr) {
-  if (emit_debug_code()) Check(cond, reason, cr);
+  if (FLAG_debug_code) Check(cond, reason, cr);
 }
 
 void TurboAssembler::Check(Condition cond, AbortReason reason, CRegister cr) {
@@ -1935,11 +1927,11 @@ void TurboAssembler::Check(Condition cond, AbortReason reason, CRegister cr) {
 void TurboAssembler::Abort(AbortReason reason) {
   Label abort_start;
   bind(&abort_start);
-#ifdef DEBUG
-  const char* msg = GetAbortReason(reason);
-  RecordComment("Abort message: ");
-  RecordComment(msg);
-#endif
+  if (FLAG_code_comments) {
+    const char* msg = GetAbortReason(reason);
+    RecordComment("Abort message: ");
+    RecordComment(msg);
+  }
 
   // Avoid emitting call to builtin if requested.
   if (trap_on_abort()) {
@@ -1984,7 +1976,7 @@ void MacroAssembler::LoadNativeContextSlot(Register dst, int index) {
 }
 
 void MacroAssembler::AssertNotSmi(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     TestIfSmi(object, r0);
     Check(ne, AbortReason::kOperandIsASmi, cr0);
@@ -1992,7 +1984,7 @@ void MacroAssembler::AssertNotSmi(Register object) {
 }
 
 void MacroAssembler::AssertSmi(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     TestIfSmi(object, r0);
     Check(eq, AbortReason::kOperandIsNotASmi, cr0);
@@ -2000,7 +1992,7 @@ void MacroAssembler::AssertSmi(Register object) {
 }
 
 void MacroAssembler::AssertConstructor(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     TestIfSmi(object, r0);
     Check(ne, AbortReason::kOperandIsASmiAndNotAConstructor, cr0);
@@ -2014,7 +2006,7 @@ void MacroAssembler::AssertConstructor(Register object) {
 }
 
 void MacroAssembler::AssertFunction(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     TestIfSmi(object, r0);
     Check(ne, AbortReason::kOperandIsASmiAndNotAFunction, cr0);
@@ -2028,7 +2020,7 @@ void MacroAssembler::AssertFunction(Register object) {
 }
 
 void MacroAssembler::AssertBoundFunction(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     TestIfSmi(object, r0);
     Check(ne, AbortReason::kOperandIsASmiAndNotABoundFunction, cr0);
@@ -2040,7 +2032,7 @@ void MacroAssembler::AssertBoundFunction(Register object) {
 }
 
 void MacroAssembler::AssertGeneratorObject(Register object) {
-  if (!emit_debug_code()) return;
+  if (!FLAG_debug_code) return;
   TestIfSmi(object, r0);
   Check(ne, AbortReason::kOperandIsASmiAndNotAGeneratorObject, cr0);
 
@@ -2070,7 +2062,7 @@ void MacroAssembler::AssertGeneratorObject(Register object) {
 
 void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
                                                      Register scratch) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label done_checking;
     AssertNotSmi(object);
     CompareRoot(object, RootIndex::kUndefinedValue);
@@ -2217,9 +2209,9 @@ void TurboAssembler::CallCFunctionHelper(Register function,
   if (ABI_USES_FUNCTION_DESCRIPTORS && has_function_descriptor) {
     // AIX/PPC64BE Linux uses a function descriptor. When calling C code be
     // aware of this descriptor and pick up values from it
-    LoadP(ToRegister(ABI_TOC_REGISTER),
-          MemOperand(function, kSystemPointerSize));
-    LoadP(ip, MemOperand(function, 0));
+    LoadU64(ToRegister(ABI_TOC_REGISTER),
+            MemOperand(function, kSystemPointerSize));
+    LoadU64(ip, MemOperand(function, 0));
     dest = ip;
   } else if (ABI_CALL_VIA_IP) {
     // pLinux and Simualtor, not AIX
@@ -2251,7 +2243,7 @@ void TurboAssembler::CallCFunctionHelper(Register function,
       CalculateStackPassedWords(num_reg_arguments, num_double_arguments);
   int stack_space = kNumRequiredStackFrameSlots + stack_passed_arguments;
   if (ActivationFrameAlignment() > kSystemPointerSize) {
-    LoadP(sp, MemOperand(sp, stack_space * kSystemPointerSize));
+    LoadU64(sp, MemOperand(sp, stack_space * kSystemPointerSize));
   } else {
     addi(sp, sp, Operand(stack_space * kSystemPointerSize));
   }
@@ -2263,7 +2255,7 @@ void TurboAssembler::CheckPageFlag(
     int mask, Condition cc, Label* condition_met) {
   DCHECK(cc == ne || cc == eq);
   ClearRightImm(scratch, object, Operand(kPageSizeBits));
-  LoadP(scratch, MemOperand(scratch, BasicMemoryChunk::kFlagsOffset));
+  LoadU64(scratch, MemOperand(scratch, BasicMemoryChunk::kFlagsOffset));
 
   mov(r0, Operand(mask));
   and_(r0, scratch, r0, SetRC);
@@ -2703,8 +2695,8 @@ void MacroAssembler::AndSmiLiteral(Register dst, Register src, Smi smi,
 }
 
 // Load a "pointer" sized value from the memory location
-void TurboAssembler::LoadP(Register dst, const MemOperand& mem,
-                           Register scratch) {
+void TurboAssembler::LoadU64(Register dst, const MemOperand& mem,
+                             Register scratch) {
   DCHECK_EQ(mem.rb(), no_reg);
   int offset = mem.offset();
   int misaligned = (offset & 3);
@@ -2797,43 +2789,41 @@ void TurboAssembler::StorePU(Register src, const MemOperand& mem,
   }
 }
 
-void TurboAssembler::LoadWordArith(Register dst, const MemOperand& mem,
-                                   Register scratch) {
+void TurboAssembler::LoadS32(Register dst, const MemOperand& mem,
+                             Register scratch) {
   int offset = mem.offset();
 
   if (!is_int16(offset)) {
-    DCHECK(scratch != no_reg);
+    CHECK(scratch != no_reg);
     mov(scratch, Operand(offset));
     lwax(dst, MemOperand(mem.ra(), scratch));
   } else {
-#if V8_TARGET_ARCH_PPC64
     int misaligned = (offset & 3);
     if (misaligned) {
       // adjust base to conform to offset alignment requirements
       // Todo: enhance to use scratch if dst is unsuitable
-      DCHECK(dst != r0);
+      CHECK(dst != r0);
       addi(dst, mem.ra(), Operand((offset & 3) - 4));
       lwa(dst, MemOperand(dst, (offset & ~3) + 4));
     } else {
       lwa(dst, mem);
     }
-#else
-    lwz(dst, mem);
-#endif
   }
 }
 
 // Variable length depending on whether offset fits into immediate field
 // MemOperand currently only supports d-form
-void TurboAssembler::LoadWord(Register dst, const MemOperand& mem,
-                              Register scratch) {
+void TurboAssembler::LoadU32(Register dst, const MemOperand& mem,
+                             Register scratch) {
   Register base = mem.ra();
   int offset = mem.offset();
 
   if (!is_int16(offset)) {
-    LoadIntLiteral(scratch, offset);
+    CHECK(scratch != no_reg);
+    mov(scratch, Operand(offset));
     lwzx(dst, MemOperand(base, scratch));
   } else {
+    // lwz can handle offset misalign
     lwz(dst, mem);
   }
 }
@@ -2992,22 +2982,8 @@ void TurboAssembler::LoadSingleU(DoubleRegister dst, const MemOperand& mem,
   }
 }
 
-void TurboAssembler::LoadSimd128(Simd128Register dst, const MemOperand& mem,
-                                 Register ScratchReg,
-                                 Simd128Register ScratchDoubleReg) {
-  // lvx needs the stack to be 16 byte aligned.
-  // We first use lxvd/stxvd to copy the content on an aligned address. lxvd
-  // itself reverses the lanes so it cannot be used as is.
-  lxvd(ScratchDoubleReg, mem);
-  mr(ScratchReg, sp);
-  ClearRightImm(
-      sp, sp,
-      Operand(base::bits::WhichPowerOfTwo(16)));  // equivalent to &= -16
-  addi(sp, sp, Operand(-16));
-  stxvd(ScratchDoubleReg, MemOperand(r0, sp));
-  // Load it with correct lane ordering.
-  lvx(dst, MemOperand(r0, sp));
-  mr(sp, ScratchReg);
+void TurboAssembler::LoadSimd128(Simd128Register dst, const MemOperand& mem) {
+  lxvx(dst, mem);
 }
 
 void TurboAssembler::StoreDouble(DoubleRegister src, const MemOperand& mem,
@@ -3062,21 +3038,8 @@ void TurboAssembler::StoreSingleU(DoubleRegister src, const MemOperand& mem,
   }
 }
 
-void TurboAssembler::StoreSimd128(Simd128Register src, const MemOperand& mem,
-                                  Register ScratchReg,
-                                  Simd128Register ScratchDoubleReg) {
-  // stvx needs the stack to be 16 byte aligned.
-  // We use lxvd/stxvd to store the content on an aligned address. stxvd
-  // itself reverses the lanes so it cannot be used as is.
-  mr(ScratchReg, sp);
-  ClearRightImm(
-      sp, sp,
-      Operand(base::bits::WhichPowerOfTwo(16)));  // equivalent to &= -16
-  addi(sp, sp, Operand(-16));
-  stvx(src, MemOperand(r0, sp));
-  lxvd(ScratchDoubleReg, MemOperand(r0, sp));
-  mr(sp, ScratchReg);
-  stxvd(ScratchDoubleReg, mem);
+void TurboAssembler::StoreSimd128(Simd128Register src, const MemOperand& mem) {
+  stxvx(src, mem);
 }
 
 Register GetRegisterThatIsNotOneOf(Register reg1, Register reg2, Register reg3,
@@ -3115,7 +3078,7 @@ void TurboAssembler::SwapP(Register src, MemOperand dst, Register scratch) {
     DCHECK(!AreAliased(src, dst.rb(), scratch));
   DCHECK(!AreAliased(src, scratch));
   mr(scratch, src);
-  LoadP(src, dst, r0);
+  LoadU64(src, dst, r0);
   StoreP(scratch, dst, r0);
 }
 
@@ -3137,14 +3100,14 @@ void TurboAssembler::SwapP(MemOperand src, MemOperand dst, Register scratch_0,
       src = dst;
       dst = temp;
     }
-    LoadP(scratch_1, dst, scratch_0);
-    LoadP(scratch_0, src);
+    LoadU64(scratch_1, dst, scratch_0);
+    LoadU64(scratch_0, src);
     StoreP(scratch_1, src);
     StoreP(scratch_0, dst, scratch_1);
   } else {
-    LoadP(scratch_1, dst, scratch_0);
+    LoadU64(scratch_1, dst, scratch_0);
     push(scratch_1);
-    LoadP(scratch_0, src, scratch_1);
+    LoadU64(scratch_0, src, scratch_1);
     StoreP(scratch_0, dst, scratch_1);
     pop(scratch_1);
     StoreP(scratch_1, src, scratch_0);
@@ -3218,13 +3181,13 @@ void TurboAssembler::SwapSimd128(Simd128Register src, MemOperand dst,
   DCHECK(src != scratch);
   // push v0, to be used as scratch
   addi(sp, sp, Operand(-kSimd128Size));
-  StoreSimd128(v0, MemOperand(r0, sp), r0, scratch);
+  StoreSimd128(v0, MemOperand(r0, sp));
   mov(ip, Operand(dst.offset()));
-  LoadSimd128(v0, MemOperand(dst.ra(), ip), r0, scratch);
-  StoreSimd128(src, MemOperand(dst.ra(), ip), r0, scratch);
+  LoadSimd128(v0, MemOperand(dst.ra(), ip));
+  StoreSimd128(src, MemOperand(dst.ra(), ip));
   vor(src, v0, v0);
   // restore v0
-  LoadSimd128(v0, MemOperand(r0, sp), ip, scratch);
+  LoadSimd128(v0, MemOperand(r0, sp));
   addi(sp, sp, Operand(kSimd128Size));
 }
 
@@ -3232,23 +3195,23 @@ void TurboAssembler::SwapSimd128(MemOperand src, MemOperand dst,
                                  Simd128Register scratch) {
   // push v0 and v1, to be used as scratch
   addi(sp, sp, Operand(2 * -kSimd128Size));
-  StoreSimd128(v0, MemOperand(r0, sp), ip, scratch);
+  StoreSimd128(v0, MemOperand(r0, sp));
   li(ip, Operand(kSimd128Size));
-  StoreSimd128(v1, MemOperand(ip, sp), r0, scratch);
+  StoreSimd128(v1, MemOperand(ip, sp));
 
   mov(ip, Operand(src.offset()));
-  LoadSimd128(v0, MemOperand(src.ra(), ip), r0, scratch);
+  LoadSimd128(v0, MemOperand(src.ra(), ip));
   mov(ip, Operand(dst.offset()));
-  LoadSimd128(v1, MemOperand(dst.ra(), ip), r0, scratch);
+  LoadSimd128(v1, MemOperand(dst.ra(), ip));
 
-  StoreSimd128(v0, MemOperand(dst.ra(), ip), r0, scratch);
+  StoreSimd128(v0, MemOperand(dst.ra(), ip));
   mov(ip, Operand(src.offset()));
-  StoreSimd128(v1, MemOperand(src.ra(), ip), r0, scratch);
+  StoreSimd128(v1, MemOperand(src.ra(), ip));
 
   // restore v0 and v1
-  LoadSimd128(v0, MemOperand(r0, sp), ip, scratch);
+  LoadSimd128(v0, MemOperand(r0, sp));
   li(ip, Operand(kSimd128Size));
-  LoadSimd128(v1, MemOperand(ip, sp), r0, scratch);
+  LoadSimd128(v1, MemOperand(ip, sp));
   addi(sp, sp, Operand(2 * kSimd128Size));
 }
 
@@ -3313,7 +3276,7 @@ void TurboAssembler::LoadCodeObjectEntry(Register destination,
     // Check whether the Code object is an off-heap trampoline. If so, call its
     // (off-heap) entry point directly without going through the (on-heap)
     // trampoline.  Otherwise, just call the Code object as always.
-    LoadWordArith(scratch, FieldMemOperand(code_object, Code::kFlagsOffset));
+    LoadS32(scratch, FieldMemOperand(code_object, Code::kFlagsOffset));
     mov(r0, Operand(Code::IsOffHeapTrampoline::kMask));
     and_(r0, scratch, r0, SetRC);
     bne(&if_code_is_off_heap, cr0);
@@ -3326,13 +3289,12 @@ void TurboAssembler::LoadCodeObjectEntry(Register destination,
     // An off-heap trampoline, the entry point is loaded from the builtin entry
     // table.
     bind(&if_code_is_off_heap);
-    LoadWordArith(scratch,
-                  FieldMemOperand(code_object, Code::kBuiltinIndexOffset));
+    LoadS32(scratch, FieldMemOperand(code_object, Code::kBuiltinIndexOffset));
     ShiftLeftImm(destination, scratch, Operand(kSystemPointerSizeLog2));
     add(destination, destination, kRootRegister);
-    LoadP(destination,
-          MemOperand(destination, IsolateData::builtin_entry_table_offset()),
-          r0);
+    LoadU64(destination,
+            MemOperand(destination, IsolateData::builtin_entry_table_offset()),
+            r0);
 
     bind(&out);
   } else {
@@ -3366,8 +3328,9 @@ void TurboAssembler::StoreReturnAddressAndCall(Register target) {
   if (ABI_USES_FUNCTION_DESCRIPTORS) {
     // AIX/PPC64BE Linux uses a function descriptor. When calling C code be
     // aware of this descriptor and pick up values from it
-    LoadP(ToRegister(ABI_TOC_REGISTER), MemOperand(target, kSystemPointerSize));
-    LoadP(ip, MemOperand(target, 0));
+    LoadU64(ToRegister(ABI_TOC_REGISTER),
+            MemOperand(target, kSystemPointerSize));
+    LoadU64(ip, MemOperand(target, 0));
     dest = ip;
   } else if (ABI_CALL_VIA_IP && dest != ip) {
     Move(ip, target);
@@ -3388,8 +3351,8 @@ void TurboAssembler::CallForDeoptimization(Builtins::Name target, int,
                                            Label* exit, DeoptimizeKind kind,
                                            Label* ret, Label*) {
   BlockTrampolinePoolScope block_trampoline_pool(this);
-  LoadP(ip, MemOperand(kRootRegister,
-                       IsolateData::builtin_entry_slot_offset(target)));
+  LoadU64(ip, MemOperand(kRootRegister,
+                         IsolateData::builtin_entry_slot_offset(target)));
   Call(ip);
   DCHECK_EQ(SizeOfCodeGeneratedSince(exit),
             (kind == DeoptimizeKind::kLazy)
diff --git a/chromium/v8/src/codegen/ppc/macro-assembler-ppc.h b/chromium/v8/src/codegen/ppc/macro-assembler-ppc.h
index 1d8f3a388d4..f657f90f760 100644
--- a/chromium/v8/src/codegen/ppc/macro-assembler-ppc.h
+++ b/chromium/v8/src/codegen/ppc/macro-assembler-ppc.h
@@ -28,8 +28,6 @@ inline MemOperand FieldMemOperand(Register object, int offset) {
   return MemOperand(object, offset - kHeapObjectTag);
 }
 
-enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
-enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
 enum LinkRegisterStatus { kLRHasNotBeenSaved, kLRHasBeenSaved };
 
 Register GetRegisterThatIsNotOneOf(Register reg1, Register reg2 = no_reg,
@@ -149,10 +147,9 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   }
 
   // These exist to provide portability between 32 and 64bit
-  void LoadP(Register dst, const MemOperand& mem, Register scratch = no_reg);
+  void LoadU64(Register dst, const MemOperand& mem, Register scratch = no_reg);
   void LoadPU(Register dst, const MemOperand& mem, Register scratch = no_reg);
-  void LoadWordArith(Register dst, const MemOperand& mem,
-                     Register scratch = no_reg);
+  void LoadS32(Register dst, const MemOperand& mem, Register scratch = no_reg);
   void StoreP(Register src, const MemOperand& mem, Register scratch = no_reg);
   void StorePU(Register src, const MemOperand& mem, Register scratch = no_reg);
 
@@ -161,8 +158,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void LoadFloat32(DoubleRegister dst, const MemOperand& mem,
                    Register scratch = no_reg);
   void LoadDoubleLiteral(DoubleRegister result, Double value, Register scratch);
-  void LoadSimd128(Simd128Register dst, const MemOperand& mem,
-                   Register ScratchReg, Simd128Register ScratchDoubleReg);
+  void LoadSimd128(Simd128Register dst, const MemOperand& mem);
 
   // load a literal signed int value <value> to GPR <dst>
   void LoadIntLiteral(Register dst, int value);
@@ -185,8 +181,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
                    Register scratch = no_reg);
   void StoreSingleU(DoubleRegister src, const MemOperand& mem,
                     Register scratch = no_reg);
-  void StoreSimd128(Simd128Register src, const MemOperand& mem,
-                    Register ScratchReg, Simd128Register ScratchDoubleReg);
+  void StoreSimd128(Simd128Register src, const MemOperand& mem);
 
   void Cmpi(Register src1, const Operand& src2, Register scratch,
             CRegister cr = cr7);
@@ -253,36 +248,36 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 
   // Pop two registers. Pops rightmost register first (from lower address).
   void Pop(Register src1, Register src2) {
-    LoadP(src2, MemOperand(sp, 0));
-    LoadP(src1, MemOperand(sp, kSystemPointerSize));
+    LoadU64(src2, MemOperand(sp, 0));
+    LoadU64(src1, MemOperand(sp, kSystemPointerSize));
     addi(sp, sp, Operand(2 * kSystemPointerSize));
   }
 
   // Pop three registers.  Pops rightmost register first (from lower address).
   void Pop(Register src1, Register src2, Register src3) {
-    LoadP(src3, MemOperand(sp, 0));
-    LoadP(src2, MemOperand(sp, kSystemPointerSize));
-    LoadP(src1, MemOperand(sp, 2 * kSystemPointerSize));
+    LoadU64(src3, MemOperand(sp, 0));
+    LoadU64(src2, MemOperand(sp, kSystemPointerSize));
+    LoadU64(src1, MemOperand(sp, 2 * kSystemPointerSize));
     addi(sp, sp, Operand(3 * kSystemPointerSize));
   }
 
   // Pop four registers.  Pops rightmost register first (from lower address).
   void Pop(Register src1, Register src2, Register src3, Register src4) {
-    LoadP(src4, MemOperand(sp, 0));
-    LoadP(src3, MemOperand(sp, kSystemPointerSize));
-    LoadP(src2, MemOperand(sp, 2 * kSystemPointerSize));
-    LoadP(src1, MemOperand(sp, 3 * kSystemPointerSize));
+    LoadU64(src4, MemOperand(sp, 0));
+    LoadU64(src3, MemOperand(sp, kSystemPointerSize));
+    LoadU64(src2, MemOperand(sp, 2 * kSystemPointerSize));
+    LoadU64(src1, MemOperand(sp, 3 * kSystemPointerSize));
     addi(sp, sp, Operand(4 * kSystemPointerSize));
   }
 
   // Pop five registers.  Pops rightmost register first (from lower address).
   void Pop(Register src1, Register src2, Register src3, Register src4,
            Register src5) {
-    LoadP(src5, MemOperand(sp, 0));
-    LoadP(src4, MemOperand(sp, kSystemPointerSize));
-    LoadP(src3, MemOperand(sp, 2 * kSystemPointerSize));
-    LoadP(src2, MemOperand(sp, 3 * kSystemPointerSize));
-    LoadP(src1, MemOperand(sp, 4 * kSystemPointerSize));
+    LoadU64(src5, MemOperand(sp, 0));
+    LoadU64(src4, MemOperand(sp, kSystemPointerSize));
+    LoadU64(src3, MemOperand(sp, 2 * kSystemPointerSize));
+    LoadU64(src2, MemOperand(sp, 3 * kSystemPointerSize));
+    LoadU64(src1, MemOperand(sp, 4 * kSystemPointerSize));
     addi(sp, sp, Operand(5 * kSystemPointerSize));
   }
 
@@ -716,7 +711,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void DecompressAnyTagged(Register destination, MemOperand field_operand);
   void DecompressAnyTagged(Register destination, Register source);
 
-  void LoadWord(Register dst, const MemOperand& mem, Register scratch);
+  void LoadU32(Register dst, const MemOperand& mem, Register scratch);
   void StoreWord(Register src, const MemOperand& mem, Register scratch);
 
  private:
@@ -743,7 +738,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // TODO(victorgomes): Remove this function once we stick with the reversed
   // arguments order.
   void LoadReceiver(Register dest, Register argc) {
-    LoadP(dest, MemOperand(sp, 0));
+    LoadU64(dest, MemOperand(sp, 0));
   }
 
   void StoreReceiver(Register rec, Register argc, Register scratch) {
@@ -761,8 +756,8 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   void RecordWriteField(
       Register object, int offset, Register value, Register scratch,
       LinkRegisterStatus lr_status, SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
   // For a given |object| notify the garbage collector that the slot |address|
   // has been written.  |value| is the object being stored. The value and
@@ -770,8 +765,8 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   void RecordWrite(
       Register object, Register address, Register value,
       LinkRegisterStatus lr_status, SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
   // Enter exit frame.
   // stack_space - extra stack space, used for parameters before call to C.
@@ -837,7 +832,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // Invoke the JavaScript function code by either calling or jumping.
   void InvokeFunctionCode(Register function, Register new_target,
                           Register expected_parameter_count,
-                          Register actual_parameter_count, InvokeFlag flag);
+                          Register actual_parameter_count, InvokeType type);
 
   // On function call, call into the debugger if necessary.
   void CheckDebugHook(Register fun, Register new_target,
@@ -848,12 +843,9 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // current context to the context in the function before invoking.
   void InvokeFunctionWithNewTarget(Register function, Register new_target,
                                    Register actual_parameter_count,
-                                   InvokeFlag flag);
+                                   InvokeType type);
   void InvokeFunction(Register function, Register expected_parameter_count,
-                      Register actual_parameter_count, InvokeFlag flag);
-
-  // Frame restart support
-  void MaybeDropFrames();
+                      Register actual_parameter_count, InvokeType type);
 
   // Exception handling
 
@@ -926,22 +918,22 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
 
   // Call a runtime routine.
   void CallRuntime(const Runtime::Function* f, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs);
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore);
   void CallRuntimeSaveDoubles(Runtime::FunctionId fid) {
     const Runtime::Function* function = Runtime::FunctionForId(fid);
-    CallRuntime(function, function->nargs, kSaveFPRegs);
+    CallRuntime(function, function->nargs, SaveFPRegsMode::kSave);
   }
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId fid,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     const Runtime::Function* function = Runtime::FunctionForId(fid);
     CallRuntime(function, function->nargs, save_doubles);
   }
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId fid, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     CallRuntime(Runtime::FunctionForId(fid), num_arguments, save_doubles);
   }
 
@@ -1053,7 +1045,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // Helper functions for generating invokes.
   void InvokePrologue(Register expected_parameter_count,
                       Register actual_parameter_count, Label* done,
-                      InvokeFlag flag);
+                      InvokeType type);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(MacroAssembler);
 };
diff --git a/chromium/v8/src/codegen/register-arch.h b/chromium/v8/src/codegen/register-arch.h
index 3936ee80cc2..eb4cdb8789b 100644
--- a/chromium/v8/src/codegen/register-arch.h
+++ b/chromium/v8/src/codegen/register-arch.h
@@ -41,6 +41,27 @@ constexpr bool ShouldPadArguments(int argument_count) {
   return ArgumentPaddingSlots(argument_count) != 0;
 }
 
+#ifdef DEBUG
+struct CountIfValidRegisterFunctor {
+  template <typename RegType>
+  constexpr int operator()(int count, RegType reg) const {
+    return count + (reg.is_valid() ? 1 : 0);
+  }
+};
+
+template <typename RegType, typename... RegTypes,
+          // All arguments must be either Register or DoubleRegister.
+          typename = typename std::enable_if<
+              base::is_same<Register, RegType, RegTypes...>::value ||
+              base::is_same<DoubleRegister, RegType, RegTypes...>::value>::type>
+inline constexpr bool AreAliased(RegType first_reg, RegTypes... regs) {
+  int num_different_regs = NumRegs(RegType::ListOf(first_reg, regs...));
+  int num_given_regs =
+      base::fold(CountIfValidRegisterFunctor{}, 0, first_reg, regs...);
+  return num_different_regs < num_given_regs;
+}
+#endif
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/chromium/v8/src/codegen/register.h b/chromium/v8/src/codegen/register.h
index 57f3a1c62ab..49f67ceb1d3 100644
--- a/chromium/v8/src/codegen/register.h
+++ b/chromium/v8/src/codegen/register.h
@@ -33,7 +33,7 @@ class RegisterBase {
   static constexpr SubType no_reg() { return SubType{kCode_no_reg}; }
 
   static constexpr SubType from_code(int code) {
-    CONSTEXPR_DCHECK(base::IsInRange(code, 0, kNumRegisters - 1));
+    DCHECK(base::IsInRange(code, 0, kNumRegisters - 1));
     return SubType{code};
   }
 
@@ -45,7 +45,7 @@ class RegisterBase {
   constexpr bool is_valid() const { return reg_code_ != kCode_no_reg; }
 
   constexpr int code() const {
-    CONSTEXPR_DCHECK(is_valid());
+    DCHECK(is_valid());
     return reg_code_;
   }
 
diff --git a/chromium/v8/src/codegen/reloc-info.cc b/chromium/v8/src/codegen/reloc-info.cc
index 753b34bdbf5..4781e7609be 100644
--- a/chromium/v8/src/codegen/reloc-info.cc
+++ b/chromium/v8/src/codegen/reloc-info.cc
@@ -4,6 +4,7 @@
 
 #include "src/codegen/reloc-info.h"
 
+#include "src/base/vlq.h"
 #include "src/codegen/assembler-inl.h"
 #include "src/codegen/code-reference.h"
 #include "src/codegen/external-reference-encoder.h"
@@ -56,11 +57,10 @@ const char* const RelocInfo::kFillerCommentString = "DEOPTIMIZATION PADDING";
 //  the following record in the usual way. The long pc jump record has variable
 //  length:
 //               pc-jump:        [PC_JUMP] 11
-//                               [7 bits data] 0
+//                               1 [7 bits data]
 //                                  ...
-//                               [7 bits data] 1
-//               (Bits 6..31 of pc delta, with leading zeroes
-//                dropped, and last non-zero chunk tagged with 1.)
+//                               0 [7 bits data]
+//               (Bits 6..31 of pc delta, encoded with VLQ.)
 
 const int kTagBits = 2;
 const int kTagMask = (1 << kTagBits) - 1;
@@ -75,12 +75,6 @@ const int kSmallPCDeltaBits = kBitsPerByte - kTagBits;
 const int kSmallPCDeltaMask = (1 << kSmallPCDeltaBits) - 1;
 const int RelocInfo::kMaxSmallPCDelta = kSmallPCDeltaMask;
 
-const int kChunkBits = 7;
-const int kChunkMask = (1 << kChunkBits) - 1;
-const int kLastChunkTagBits = 1;
-const int kLastChunkTagMask = 1;
-const int kLastChunkTag = 1;
-
 uint32_t RelocInfoWriter::WriteLongPCJump(uint32_t pc_delta) {
   // Return if the pc_delta can fit in kSmallPCDeltaBits bits.
   // Otherwise write a variable length PC jump for the bits that do
@@ -89,13 +83,12 @@ uint32_t RelocInfoWriter::WriteLongPCJump(uint32_t pc_delta) {
   WriteMode(RelocInfo::PC_JUMP);
   uint32_t pc_jump = pc_delta >> kSmallPCDeltaBits;
   DCHECK_GT(pc_jump, 0);
-  // Write kChunkBits size chunks of the pc_jump.
-  for (; pc_jump > 0; pc_jump = pc_jump >> kChunkBits) {
-    byte b = pc_jump & kChunkMask;
-    *--pos_ = b << kLastChunkTagBits;
-  }
-  // Tag the last chunk so it can be identified.
-  *pos_ = *pos_ | kLastChunkTag;
+  base::VLQEncodeUnsigned(
+      [this](byte byte) {
+        *--pos_ = byte;
+        return pos_;
+      },
+      pc_jump);
   // Return the remaining kSmallPCDeltaBits of the pc_delta.
   return pc_delta & kSmallPCDeltaMask;
 }
@@ -205,14 +198,8 @@ void RelocIterator::AdvanceReadData() {
 
 void RelocIterator::AdvanceReadLongPCJump() {
   // Read the 32-kSmallPCDeltaBits most significant bits of the
-  // pc jump in kChunkBits bit chunks and shift them into place.
-  // Stop when the last chunk is encountered.
-  uint32_t pc_jump = 0;
-  for (int i = 0; i < kIntSize; i++) {
-    byte pc_jump_part = *--pos_;
-    pc_jump |= (pc_jump_part >> kLastChunkTagBits) << i * kChunkBits;
-    if ((pc_jump_part & kLastChunkTagMask) == 1) break;
-  }
+  // pc jump as a VLQ encoded integer.
+  uint32_t pc_jump = base::VLQDecodeUnsigned([this] { return *--pos_; });
   // The least significant kSmallPCDeltaBits bits will be added
   // later.
   rinfo_.pc_ += pc_jump << kSmallPCDeltaBits;
@@ -450,7 +437,7 @@ const char* RelocInfo::RelocModeName(RelocInfo::Mode rmode) {
   return "unknown relocation type";
 }
 
-void RelocInfo::Print(Isolate* isolate, std::ostream& os) {  // NOLINT
+void RelocInfo::Print(Isolate* isolate, std::ostream& os) {
   os << reinterpret_cast<const void*>(pc_) << "  " << RelocModeName(rmode_);
   if (rmode_ == DEOPT_SCRIPT_OFFSET || rmode_ == DEOPT_INLINING_ID) {
     os << "  (" << data() << ")";
diff --git a/chromium/v8/src/codegen/reloc-info.h b/chromium/v8/src/codegen/reloc-info.h
index bef433e10b1..e8b3c0b98bb 100644
--- a/chromium/v8/src/codegen/reloc-info.h
+++ b/chromium/v8/src/codegen/reloc-info.h
@@ -328,8 +328,8 @@ class RelocInfo {
 #ifdef ENABLE_DISASSEMBLER
   // Printing
   static const char* RelocModeName(Mode rmode);
-  void Print(Isolate* isolate, std::ostream& os);  // NOLINT
-#endif                                             // ENABLE_DISASSEMBLER
+  void Print(Isolate* isolate, std::ostream& os);
+#endif  // ENABLE_DISASSEMBLER
 #ifdef VERIFY_HEAP
   void Verify(Isolate* isolate);
 #endif
diff --git a/chromium/v8/src/codegen/riscv64/assembler-riscv64-inl.h b/chromium/v8/src/codegen/riscv64/assembler-riscv64-inl.h
index 40bd56d15b5..d301a00bf4e 100644
--- a/chromium/v8/src/codegen/riscv64/assembler-riscv64-inl.h
+++ b/chromium/v8/src/codegen/riscv64/assembler-riscv64-inl.h
@@ -63,11 +63,15 @@ void RelocInfo::apply(intptr_t delta) {
   if (IsInternalReference(rmode_) || IsInternalReferenceEncoded(rmode_)) {
     // Absolute code pointer inside code object moves with the code object.
     Assembler::RelocateInternalReference(rmode_, pc_, delta);
+  } else {
+    DCHECK(IsRelativeCodeTarget(rmode_));
+    Assembler::RelocateRelativeReference(rmode_, pc_, delta);
   }
 }
 
 Address RelocInfo::target_address() {
-  DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_) || IsWasmCall(rmode_));
+  DCHECK(IsCodeTargetMode(rmode_) || IsRuntimeEntry(rmode_) ||
+         IsWasmCall(rmode_));
   return Assembler::target_address_at(pc_, constant_pool_);
 }
 
@@ -133,9 +137,13 @@ HeapObject RelocInfo::target_object_no_host(Isolate* isolate) {
 }
 
 Handle<HeapObject> RelocInfo::target_object_handle(Assembler* origin) {
-  DCHECK(IsCodeTarget(rmode_) || IsFullEmbeddedObject(rmode_));
-  return Handle<HeapObject>(reinterpret_cast<Address*>(
-      Assembler::target_address_at(pc_, constant_pool_)));
+  if (IsCodeTarget(rmode_) || IsFullEmbeddedObject(rmode_)) {
+    return Handle<HeapObject>(reinterpret_cast<Address*>(
+        Assembler::target_address_at(pc_, constant_pool_)));
+  } else {
+    DCHECK(IsRelativeCodeTarget(rmode_));
+    return origin->relative_code_target_object_handle_at(pc_);
+  }
 }
 
 void RelocInfo::set_target_object(Heap* heap, HeapObject target,
@@ -163,11 +171,11 @@ void RelocInfo::set_target_external_reference(
 }
 
 Address RelocInfo::target_internal_reference() {
-  if (rmode_ == INTERNAL_REFERENCE) {
+  if (IsInternalReference(rmode_)) {
     return Memory<Address>(pc_);
   } else {
     // Encoded internal references are j/jal instructions.
-    DCHECK(rmode_ == INTERNAL_REFERENCE_ENCODED);
+    DCHECK(IsInternalReferenceEncoded(rmode_));
     DCHECK(Assembler::IsLui(Assembler::instr_at(pc_ + 0 * kInstrSize)));
     Address address = Assembler::target_address_at(pc_);
     return address;
@@ -175,10 +183,20 @@ Address RelocInfo::target_internal_reference() {
 }
 
 Address RelocInfo::target_internal_reference_address() {
-  DCHECK(rmode_ == INTERNAL_REFERENCE || rmode_ == INTERNAL_REFERENCE_ENCODED);
+  DCHECK(IsInternalReference(rmode_) || IsInternalReferenceEncoded(rmode_));
   return pc_;
 }
 
+Handle<Code> Assembler::relative_code_target_object_handle_at(
+    Address pc) const {
+  Instr instr1 = Assembler::instr_at(pc);
+  Instr instr2 = Assembler::instr_at(pc + kInstrSize);
+  DCHECK(IsAuipc(instr1));
+  DCHECK(IsJalr(instr2));
+  int32_t code_target_index = BrachlongOffset(instr1, instr2);
+  return GetCodeTarget(code_target_index);
+}
+
 Address RelocInfo::target_runtime_entry(Assembler* origin) {
   DCHECK(IsRuntimeEntry(rmode_));
   return target_address();
diff --git a/chromium/v8/src/codegen/riscv64/assembler-riscv64.cc b/chromium/v8/src/codegen/riscv64/assembler-riscv64.cc
index 914ea26f9fe..35c56ccdf53 100644
--- a/chromium/v8/src/codegen/riscv64/assembler-riscv64.cc
+++ b/chromium/v8/src/codegen/riscv64/assembler-riscv64.cc
@@ -128,7 +128,8 @@ Register ToRegister(int num) {
 
 const int RelocInfo::kApplyMask =
     RelocInfo::ModeMask(RelocInfo::INTERNAL_REFERENCE) |
-    RelocInfo::ModeMask(RelocInfo::INTERNAL_REFERENCE_ENCODED);
+    RelocInfo::ModeMask(RelocInfo::INTERNAL_REFERENCE_ENCODED) |
+    RelocInfo::ModeMask(RelocInfo::RELATIVE_CODE_TARGET);
 
 bool RelocInfo::IsCodedSpecially() {
   // The deserializer needs to know whether a pointer is specially coded.  Being
@@ -454,6 +455,16 @@ static inline Instr SetAuipcOffset(int32_t offset, Instr instr) {
   return instr;
 }
 
+static inline Instr SetJalrOffset(int32_t offset, Instr instr) {
+  DCHECK(Assembler::IsJalr(instr));
+  DCHECK(is_int12(offset));
+  instr &= ~kImm12Mask;
+  int32_t imm12 = offset << kImm12Shift;
+  DCHECK(Assembler::IsJalr(instr | (imm12 & kImm12Mask)));
+  DCHECK(Assembler::JalrOffset(instr | (imm12 & kImm12Mask)) == offset);
+  return instr | (imm12 & kImm12Mask);
+}
+
 static inline Instr SetJalOffset(int32_t pos, int32_t target_pos, Instr instr) {
   DCHECK(Assembler::IsJal(instr));
   int32_t imm = target_pos - pos;
@@ -689,17 +700,36 @@ int Assembler::CJumpOffset(Instr instr) {
 int Assembler::BrachlongOffset(Instr auipc, Instr instr_I) {
   DCHECK(reinterpret_cast<Instruction*>(&instr_I)->InstructionType() ==
          InstructionBase::kIType);
-  const int kImm19_0Mask = ((1 << 20) - 1);
-  int32_t imm_auipc = auipc & (kImm19_0Mask << 12);
-  int32_t imm_12 = instr_I >> 20;
-  int32_t offset = imm_12 + imm_auipc;
+  DCHECK(IsAuipc(auipc));
+  int32_t imm_auipc = AuipcOffset(auipc);
+  int32_t imm12 = (instr_I & kImm12Mask) >> 20;
+  int32_t offset = imm12 + imm_auipc;
   return offset;
 }
 
+int Assembler::PatchBranchlongOffset(Address pc, Instr instr_auipc,
+                                     Instr instr_jalr, int32_t offset) {
+  DCHECK(IsAuipc(instr_auipc));
+  DCHECK(IsJalr(instr_jalr));
+  int32_t Hi20 = (((int32_t)offset + 0x800) >> 12);
+  int32_t Lo12 = (int32_t)offset << 20 >> 20;
+  CHECK(is_int32(offset));
+  instr_at_put(pc, SetAuipcOffset(Hi20, instr_auipc));
+  instr_at_put(pc + 4, SetJalrOffset(Lo12, instr_jalr));
+  DCHECK(offset ==
+         BrachlongOffset(Assembler::instr_at(pc), Assembler::instr_at(pc + 4)));
+  return 2;
+}
+
 int Assembler::LdOffset(Instr instr) {
   DCHECK(IsLd(instr));
   int32_t imm12 = (instr & kImm12Mask) >> 20;
-  imm12 = imm12 << 12 >> 12;
+  return imm12;
+}
+
+int Assembler::JalrOffset(Instr instr) {
+  DCHECK(IsJalr(instr));
+  int32_t imm12 = (instr & kImm12Mask) >> 20;
   return imm12;
 }
 
@@ -717,7 +747,7 @@ bool Assembler::MustUseReg(RelocInfo::Mode rmode) {
 }
 
 void Assembler::disassembleInstr(Instr instr) {
-  if (!FLAG_debug_riscv) return;
+  if (!FLAG_riscv_debug) return;
   disasm::NameConverter converter;
   disasm::Disassembler disasm(converter);
   EmbeddedVector<char, 128> disasm_buffer;
@@ -2567,9 +2597,25 @@ void Assembler::AdjustBaseAndOffset(MemOperand* src, Register scratch,
   // Must not overwrite the register 'base' while loading 'offset'.
   DCHECK(src->rm() != scratch);
 
-  RV_li(scratch, src->offset());
-  add(scratch, scratch, src->rm());
-  src->offset_ = 0;
+  constexpr int32_t kMinOffsetForSimpleAdjustment = 0x7F8;
+  constexpr int32_t kMaxOffsetForSimpleAdjustment =
+      2 * kMinOffsetForSimpleAdjustment;
+  if (0 <= src->offset() && src->offset() <= kMaxOffsetForSimpleAdjustment) {
+    addi(scratch, src->rm(), kMinOffsetForSimpleAdjustment);
+    src->offset_ -= kMinOffsetForSimpleAdjustment;
+  } else if (-kMaxOffsetForSimpleAdjustment <= src->offset() &&
+             src->offset() < 0) {
+    addi(scratch, src->rm(), -kMinOffsetForSimpleAdjustment);
+    src->offset_ += kMinOffsetForSimpleAdjustment;
+  } else if (access_type == OffsetAccessType::SINGLE_ACCESS) {
+    RV_li(scratch, (static_cast<int64_t>(src->offset()) + 0x800) >> 12 << 12);
+    add(scratch, scratch, src->rm());
+    src->offset_ = src->offset() << 20 >> 20;
+  } else {
+    RV_li(scratch, src->offset());
+    add(scratch, scratch, src->rm());
+    src->offset_ = 0;
+  }
   src->rm_ = scratch;
 }
 
@@ -2596,6 +2642,22 @@ int Assembler::RelocateInternalReference(RelocInfo::Mode rmode, Address pc,
   }
 }
 
+void Assembler::RelocateRelativeReference(RelocInfo::Mode rmode, Address pc,
+                                          intptr_t pc_delta) {
+  Instr instr = instr_at(pc);
+  Instr instr1 = instr_at(pc + 1 * kInstrSize);
+  DCHECK(RelocInfo::IsRelativeCodeTarget(rmode));
+  if (IsAuipc(instr) && IsJalr(instr1)) {
+    int32_t imm;
+    imm = BrachlongOffset(instr, instr1);
+    imm -= pc_delta;
+    PatchBranchlongOffset(pc, instr, instr1, imm);
+    return;
+  } else {
+    UNREACHABLE();
+  }
+}
+
 void Assembler::GrowBuffer() {
   DEBUG_PRINTF("GrowBuffer: %p -> ", buffer_start_);
   // Compute new buffer size.
@@ -2766,12 +2828,23 @@ void Assembler::set_target_address_at(Address pc, Address constant_pool,
                                       ICacheFlushMode icache_flush_mode) {
   Instr* instr = reinterpret_cast<Instr*>(pc);
   if (IsAuipc(*instr)) {
-    DCHECK(IsLd(*reinterpret_cast<Instr*>(pc + 4)));
-    int32_t Hi20 = AuipcOffset(*instr);
-    int32_t Lo12 = LdOffset(*reinterpret_cast<Instr*>(pc + 4));
-    Memory<Address>(pc + Hi20 + Lo12) = target;
-    if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
-      FlushInstructionCache(pc + Hi20 + Lo12, 2 * kInstrSize);
+    if (IsLd(*reinterpret_cast<Instr*>(pc + 4))) {
+      int32_t Hi20 = AuipcOffset(*instr);
+      int32_t Lo12 = LdOffset(*reinterpret_cast<Instr*>(pc + 4));
+      Memory<Address>(pc + Hi20 + Lo12) = target;
+      if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
+        FlushInstructionCache(pc + Hi20 + Lo12, 2 * kInstrSize);
+      }
+    } else {
+      DCHECK(IsJalr(*reinterpret_cast<Instr*>(pc + 4)));
+      int64_t imm = (int64_t)target - (int64_t)pc;
+      Instr instr = instr_at(pc);
+      Instr instr1 = instr_at(pc + 1 * kInstrSize);
+      DCHECK(is_int32(imm));
+      int num = PatchBranchlongOffset(pc, instr, instr1, (int32_t)imm);
+      if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
+        FlushInstructionCache(pc, num * kInstrSize);
+      }
     }
   } else {
     set_target_address_at(pc, target, icache_flush_mode);
@@ -2781,10 +2854,17 @@ void Assembler::set_target_address_at(Address pc, Address constant_pool,
 Address Assembler::target_address_at(Address pc, Address constant_pool) {
   Instr* instr = reinterpret_cast<Instr*>(pc);
   if (IsAuipc(*instr)) {
-    DCHECK(IsLd(*reinterpret_cast<Instr*>(pc + 4)));
-    int32_t Hi20 = AuipcOffset(*instr);
-    int32_t Lo12 = LdOffset(*reinterpret_cast<Instr*>(pc + 4));
-    return Memory<Address>(pc + Hi20 + Lo12);
+    if (IsLd(*reinterpret_cast<Instr*>(pc + 4))) {
+      int32_t Hi20 = AuipcOffset(*instr);
+      int32_t Lo12 = LdOffset(*reinterpret_cast<Instr*>(pc + 4));
+      return Memory<Address>(pc + Hi20 + Lo12);
+    } else {
+      DCHECK(IsJalr(*reinterpret_cast<Instr*>(pc + 4)));
+      int32_t Hi20 = AuipcOffset(*instr);
+      int32_t Lo12 = JalrOffset(*reinterpret_cast<Instr*>(pc + 4));
+      return pc + Hi20 + Lo12;
+    }
+
   } else {
     return target_address_at(pc);
   }
@@ -2890,17 +2970,17 @@ bool UseScratchRegisterScope::hasAvailable() const { return *available_ != 0; }
 bool Assembler::IsConstantPoolAt(Instruction* instr) {
   // The constant pool marker is made of two instructions. These instructions
   // will never be emitted by the JIT, so checking for the first one is enough:
-  // 0: ld x0, t3, #offset
+  // 0: ld x0, x0, #offset
   Instr instr_value = *reinterpret_cast<Instr*>(instr);
-
-  bool result = IsLd(instr_value) && (instr->RdValue() == kRegCode_zero_reg);
-  // It is still worth asserting the marker is complete.
-  // 4: j 0
+  bool result = IsLd(instr_value) && (instr->Rs1Value() == kRegCode_zero_reg) &&
+                (instr->RdValue() == kRegCode_zero_reg);
 #ifdef DEBUG
-  Instruction* instr_fllowing = instr + kInstrSize;
-  DCHECK(!result || (IsJal(*reinterpret_cast<Instr*>(instr_fllowing)) &&
-                     instr_fllowing->Imm20JValue() == 0 &&
-                     instr_fllowing->RdValue() == kRegCode_zero_reg));
+  // It is still worth asserting the marker is complete.
+  // 1: j 0x0
+  Instruction* instr_following = instr + kInstrSize;
+  DCHECK(!result || (IsJal(*reinterpret_cast<Instr*>(instr_following)) &&
+                     instr_following->Imm20JValue() == 0 &&
+                     instr_following->RdValue() == kRegCode_zero_reg));
 #endif
   return result;
 }
@@ -2941,9 +3021,9 @@ void ConstantPool::EmitPrologue(Alignment require_alignment) {
 
 int ConstantPool::PrologueSize(Jump require_jump) const {
   // Prologue is:
-  //   j   over  ;; if require_jump
-  //   ld x0, t3, #pool_size
-  //   j xzr
+  //   j over  ;; if require_jump
+  //   ld x0, x0, #pool_size
+  //   j 0x0
   int prologue_size = require_jump == Jump::kRequired ? kInstrSize : 0;
   prologue_size += 2 * kInstrSize;
   return prologue_size;
@@ -2954,7 +3034,7 @@ void ConstantPool::SetLoadOffsetToConstPoolEntry(int load_offset,
                                                  const ConstantPoolKey& key) {
   Instr instr_auipc = assm_->instr_at(load_offset);
   Instr instr_ld = assm_->instr_at(load_offset + 4);
-  // Instruction to patch must be 'ld t3, t3, offset' with offset == kInstrSize.
+  // Instruction to patch must be 'ld rd, offset(rd)' with 'offset == 0'.
   DCHECK(assm_->IsAuipc(instr_auipc));
   DCHECK(assm_->IsLd(instr_ld));
   DCHECK_EQ(assm_->LdOffset(instr_ld), 0);
diff --git a/chromium/v8/src/codegen/riscv64/assembler-riscv64.h b/chromium/v8/src/codegen/riscv64/assembler-riscv64.h
index 1dcf4e0aae1..ff66351d6a4 100644
--- a/chromium/v8/src/codegen/riscv64/assembler-riscv64.h
+++ b/chromium/v8/src/codegen/riscv64/assembler-riscv64.h
@@ -53,7 +53,7 @@ namespace v8 {
 namespace internal {
 
 #define DEBUG_PRINTF(...) \
-  if (FLAG_debug_riscv) { \
+  if (FLAG_riscv_debug) { \
     printf(__VA_ARGS__);  \
   }
 
@@ -160,6 +160,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
 
   virtual ~Assembler() { CHECK(constpool_.IsEmpty()); }
 
+  void AbortedCodeGeneration() { constpool_.Clear(); }
   // GetCode emits any pending (non-emitted) code and fills the descriptor desc.
   static constexpr int kNoHandlerTable = 0;
   static constexpr SafepointTableBuilder* kNoSafepointTable = nullptr;
@@ -208,11 +209,14 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
 
   // Get offset from instr.
   int BranchOffset(Instr instr);
-  int BrachlongOffset(Instr auipc, Instr jalr);
+  static int BrachlongOffset(Instr auipc, Instr jalr);
+  static int PatchBranchlongOffset(Address pc, Instr auipc, Instr instr_I,
+                                   int32_t offset);
   int JumpOffset(Instr instr);
   int CJumpOffset(Instr instr);
   static int LdOffset(Instr instr);
   static int AuipcOffset(Instr instr);
+  static int JalrOffset(Instr instr);
 
   // Returns the branch offset to the given label from the current code
   // position. Links the label to the current position if it is still unbound.
@@ -800,6 +804,8 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
 
   static int RelocateInternalReference(RelocInfo::Mode rmode, Address pc,
                                        intptr_t pc_delta);
+  static void RelocateRelativeReference(RelocInfo::Mode rmode, Address pc,
+                                        intptr_t pc_delta);
 
   // Writes a single byte or word of data in the code stream.  Used for
   // inline tables, e.g., jump-tables.
@@ -862,8 +868,40 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   static bool IsLd(Instr instr);
   void CheckTrampolinePool();
 
+  // Get the code target object for a pc-relative call or jump.
+  V8_INLINE Handle<Code> relative_code_target_object_handle_at(
+      Address pc_) const;
+
   inline int UnboundLabelsCount() { return unbound_labels_count_; }
 
+  using BlockPoolsScope = BlockTrampolinePoolScope;
+
+  void RecordConstPool(int size);
+
+  void ForceConstantPoolEmissionWithoutJump() {
+    constpool_.Check(Emission::kForced, Jump::kOmitted);
+  }
+  void ForceConstantPoolEmissionWithJump() {
+    constpool_.Check(Emission::kForced, Jump::kRequired);
+  }
+  // Check if the const pool needs to be emitted while pretending that {margin}
+  // more bytes of instructions have already been emitted.
+  void EmitConstPoolWithJumpIfNeeded(size_t margin = 0) {
+    constpool_.Check(Emission::kIfNeeded, Jump::kRequired, margin);
+  }
+
+  void EmitConstPoolWithoutJumpIfNeeded(size_t margin = 0) {
+    constpool_.Check(Emission::kIfNeeded, Jump::kOmitted, margin);
+  }
+
+  void RecordEntry(uint32_t data, RelocInfo::Mode rmode) {
+    constpool_.RecordEntry(data, rmode);
+  }
+
+  void RecordEntry(uint64_t data, RelocInfo::Mode rmode) {
+    constpool_.RecordEntry(data, rmode);
+  }
+
  protected:
   // Readable constants for base and offset adjustment helper, these indicate if
   // aside from offset, another value like offset + 4 should fit into int16.
@@ -949,34 +987,6 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
     }
   }
 
-  using BlockPoolsScope = BlockTrampolinePoolScope;
-
-  void RecordConstPool(int size);
-
-  void ForceConstantPoolEmissionWithoutJump() {
-    constpool_.Check(Emission::kForced, Jump::kOmitted);
-  }
-  void ForceConstantPoolEmissionWithJump() {
-    constpool_.Check(Emission::kForced, Jump::kRequired);
-  }
-  // Check if the const pool needs to be emitted while pretending that {margin}
-  // more bytes of instructions have already been emitted.
-  void EmitConstPoolWithJumpIfNeeded(size_t margin = 0) {
-    constpool_.Check(Emission::kIfNeeded, Jump::kRequired, margin);
-  }
-
-  void EmitConstPoolWithoutJumpIfNeeded(size_t margin = 0) {
-    constpool_.Check(Emission::kIfNeeded, Jump::kOmitted, margin);
-  }
-
-  void RecordEntry(uint32_t data, RelocInfo::Mode rmode) {
-    constpool_.RecordEntry(data, rmode);
-  }
-
-  void RecordEntry(uint64_t data, RelocInfo::Mode rmode) {
-    constpool_.RecordEntry(data, rmode);
-  }
-
  private:
   // Avoid overflows for displacements etc.
   static const int kMaximalBufferSize = 512 * MB;
@@ -1231,6 +1241,16 @@ class V8_EXPORT_PRIVATE UseScratchRegisterScope {
 
   Register Acquire();
   bool hasAvailable() const;
+  void Include(const RegList& list) { *available_ |= list; }
+  void Exclude(const RegList& list) { *available_ &= ~list; }
+  void Include(const Register& reg1, const Register& reg2 = no_reg) {
+    RegList list(reg1.bit() | reg2.bit());
+    Include(list);
+  }
+  void Exclude(const Register& reg1, const Register& reg2 = no_reg) {
+    RegList list(reg1.bit() | reg2.bit());
+    Exclude(list);
+  }
 
  private:
   RegList* available_;
diff --git a/chromium/v8/src/codegen/riscv64/constants-riscv64.cc b/chromium/v8/src/codegen/riscv64/constants-riscv64.cc
index 045488bf7fa..d2709dc2c7c 100644
--- a/chromium/v8/src/codegen/riscv64/constants-riscv64.cc
+++ b/chromium/v8/src/codegen/riscv64/constants-riscv64.cc
@@ -106,8 +106,11 @@ int FPURegisters::Number(const char* name) {
 }
 
 InstructionBase::Type InstructionBase::InstructionType() const {
+  if (IsIllegalInstruction()) {
+    return kUnsupported;
+  }
   // RV64C Instruction
-  if (IsShortInstruction()) {
+  if (FLAG_riscv_c_extension && IsShortInstruction()) {
     switch (InstructionBits() & kRvcOpcodeMask) {
       case RO_C_ADDI4SPN:
         return kCIWType;
diff --git a/chromium/v8/src/codegen/riscv64/constants-riscv64.h b/chromium/v8/src/codegen/riscv64/constants-riscv64.h
index 3b5ffff6dac..c8f54d8f7f9 100644
--- a/chromium/v8/src/codegen/riscv64/constants-riscv64.h
+++ b/chromium/v8/src/codegen/riscv64/constants-riscv64.h
@@ -8,6 +8,7 @@
 #include "src/base/logging.h"
 #include "src/base/macros.h"
 #include "src/common/globals.h"
+#include "src/flags/flags.h"
 
 // UNIMPLEMENTED_ macro for RISCV.
 #ifdef DEBUG
@@ -55,8 +56,7 @@ const uint32_t kLessSignificantWordInDoublewordOffset = 4;
 namespace v8 {
 namespace internal {
 
-// TODO(sigurds): Change this value once we use relative jumps.
-constexpr size_t kMaxPCRelativeCodeRangeInMB = 0;
+constexpr size_t kMaxPCRelativeCodeRangeInMB = 4096;
 
 // -----------------------------------------------------------------------------
 // Registers and FPURegisters.
@@ -727,18 +727,25 @@ class InstructionBase {
     kUnsupported = -1
   };
 
+  inline bool IsIllegalInstruction() const {
+    uint8_t FirstHalfWord = *reinterpret_cast<const uint16_t*>(this);
+    return FirstHalfWord == 0;
+  }
+
   inline bool IsShortInstruction() const {
     uint8_t FirstByte = *reinterpret_cast<const uint8_t*>(this);
     return (FirstByte & 0x03) <= C2;
   }
 
   inline uint8_t InstructionSize() const {
-    return this->IsShortInstruction() ? kShortInstrSize : kInstrSize;
+    return (FLAG_riscv_c_extension && this->IsShortInstruction())
+               ? kShortInstrSize
+               : kInstrSize;
   }
 
   // Get the raw instruction bits.
   inline Instr InstructionBits() const {
-    if (this->IsShortInstruction()) {
+    if (FLAG_riscv_c_extension && this->IsShortInstruction()) {
       return 0x0000FFFF & (*reinterpret_cast<const ShortInstr*>(this));
     }
     return *reinterpret_cast<const Instr*>(this);
diff --git a/chromium/v8/src/codegen/riscv64/interface-descriptors-riscv64-inl.h b/chromium/v8/src/codegen/riscv64/interface-descriptors-riscv64-inl.h
new file mode 100644
index 00000000000..4a8bb0d9ee6
--- /dev/null
+++ b/chromium/v8/src/codegen/riscv64/interface-descriptors-riscv64-inl.h
@@ -0,0 +1,265 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_CODEGEN_RISCV64_INTERFACE_DESCRIPTORS_RISCV64_INL_H_
+#define V8_CODEGEN_RISCV64_INTERFACE_DESCRIPTORS_RISCV64_INL_H_
+
+#if V8_TARGET_ARCH_RISCV64
+
+#include "src/base/template-utils.h"
+#include "src/codegen/interface-descriptors.h"
+#include "src/execution/frames.h"
+
+namespace v8 {
+namespace internal {
+
+constexpr auto CallInterfaceDescriptor::DefaultRegisterArray() {
+  auto registers = RegisterArray(a0, a1, a2, a3, a4);
+  STATIC_ASSERT(registers.size() == kMaxBuiltinRegisterParams);
+  return registers;
+}
+
+// static
+constexpr auto RecordWriteDescriptor::registers() {
+  return RegisterArray(a0, a1, a2, a3, kReturnRegister0);
+}
+
+// static
+constexpr auto DynamicCheckMapsDescriptor::registers() {
+  return RegisterArray(kReturnRegister0, a1, a2, a3, cp);
+}
+
+// static
+constexpr auto EphemeronKeyBarrierDescriptor::registers() {
+  return RegisterArray(a0, a1, a2, a3, kReturnRegister0);
+}
+
+// static
+constexpr Register LoadDescriptor::ReceiverRegister() { return a1; }
+// static
+constexpr Register LoadDescriptor::NameRegister() { return a2; }
+// static
+constexpr Register LoadDescriptor::SlotRegister() { return a0; }
+
+// static
+constexpr Register LoadWithVectorDescriptor::VectorRegister() { return a3; }
+
+// static
+constexpr Register
+LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
+  return a4;
+}
+
+// static
+constexpr Register StoreDescriptor::ReceiverRegister() { return a1; }
+// static
+constexpr Register StoreDescriptor::NameRegister() { return a2; }
+// static
+constexpr Register StoreDescriptor::ValueRegister() { return a0; }
+// static
+constexpr Register StoreDescriptor::SlotRegister() { return a4; }
+
+// static
+constexpr Register StoreWithVectorDescriptor::VectorRegister() { return a3; }
+
+// static
+constexpr Register StoreTransitionDescriptor::MapRegister() { return a5; }
+
+// static
+constexpr Register ApiGetterDescriptor::HolderRegister() { return a0; }
+// static
+constexpr Register ApiGetterDescriptor::CallbackRegister() { return a3; }
+
+// static
+constexpr Register GrowArrayElementsDescriptor::ObjectRegister() { return a0; }
+// static
+constexpr Register GrowArrayElementsDescriptor::KeyRegister() { return a3; }
+
+// static
+constexpr Register BaselineLeaveFrameDescriptor::ParamsSizeRegister() {
+  return a2;
+}
+// static
+constexpr Register BaselineLeaveFrameDescriptor::WeightRegister() { return a3; }
+
+// static
+// static
+constexpr Register TypeConversionDescriptor::ArgumentRegister() { return a0; }
+
+// static
+constexpr auto TypeofDescriptor::registers() { return RegisterArray(a3); }
+
+// static
+constexpr auto CallTrampolineDescriptor::registers() {
+  // a1: target
+  // a0: number of arguments
+  return RegisterArray(a1, a0);
+}
+
+// static
+constexpr auto CallVarargsDescriptor::registers() {
+  // a0 : number of arguments (on the stack, not including receiver)
+  // a1 : the target to call
+  // a4 : arguments list length (untagged)
+  // a2 : arguments list (FixedArray)
+  return RegisterArray(a1, a0, a4, a2);
+}
+
+// static
+constexpr auto CallForwardVarargsDescriptor::registers() {
+  // a1: target
+  // a0: number of arguments
+  // a2: start index (to supported rest parameters)
+  return RegisterArray(a1, a0, a2);
+}
+
+// static
+constexpr auto CallFunctionTemplateDescriptor::registers() {
+  // a1 : function template info
+  // a0 : number of arguments (on the stack, not including receiver)
+  return RegisterArray(a1, a0);
+}
+
+// static
+constexpr auto CallWithSpreadDescriptor::registers() {
+  // a0 : number of arguments (on the stack, not including receiver)
+  // a1 : the target to call
+  // a2 : the object to spread
+  return RegisterArray(a1, a0, a2);
+}
+
+// static
+constexpr auto CallWithArrayLikeDescriptor::registers() {
+  // a1 : the target to call
+  // a2 : the arguments list
+  return RegisterArray(a1, a2);
+}
+
+// static
+constexpr auto ConstructVarargsDescriptor::registers() {
+  // a0 : number of arguments (on the stack, not including receiver)
+  // a1 : the target to call
+  // a3 : the new target
+  // a4 : arguments list length (untagged)
+  // a2 : arguments list (FixedArray)
+  return RegisterArray(a1, a3, a0, a4, a2);
+}
+
+// static
+constexpr auto ConstructForwardVarargsDescriptor::registers() {
+  // a3: new target
+  // a1: target
+  // a0: number of arguments
+  // a2: start index (to supported rest parameters)
+  return RegisterArray(a1, a3, a0, a2);
+}
+
+// static
+constexpr auto ConstructWithSpreadDescriptor::registers() {
+  // a0 : number of arguments (on the stack, not including receiver)
+  // a1 : the target to call
+  // a3 : the new target
+  // a2 : the object to spread
+  return RegisterArray(a1, a3, a0, a2);
+}
+
+// static
+constexpr auto ConstructWithArrayLikeDescriptor::registers() {
+  // a1 : the target to call
+  // a3 : the new target
+  // a2 : the arguments list
+  return RegisterArray(a1, a3, a2);
+}
+
+// static
+constexpr auto ConstructStubDescriptor::registers() {
+  // a3: new target
+  // a1: target
+  // a0: number of arguments
+  // a2: allocation site or undefined
+  return RegisterArray(a1, a3, a0, a2);
+}
+
+// static
+constexpr auto AbortDescriptor::registers() { return RegisterArray(a0); }
+
+// static
+constexpr auto CompareDescriptor::registers() {
+  // a1: left operand
+  // a0: right operand
+  return RegisterArray(a1, a0);
+}
+
+// static
+constexpr auto Compare_BaselineDescriptor::registers() {
+  // a1: left operand
+  // a0: right operand
+  // a2: feedback slot
+  return RegisterArray(a1, a0, a2);
+}
+
+// static
+constexpr auto BinaryOpDescriptor::registers() {
+  // a1: left operand
+  // a0: right operand
+  return RegisterArray(a1, a0);
+}
+
+// static
+constexpr auto BinaryOp_BaselineDescriptor::registers() {
+  // a1: left operand
+  // a0: right operand
+  // a2: feedback slot
+  return RegisterArray(a1, a0, a2);
+}
+
+// static
+constexpr auto ApiCallbackDescriptor::registers() {
+  return RegisterArray(a1,   // kApiFunctionAddress
+                       a2,   // kArgc
+                       a3,   // kCallData
+                       a0);  // kHolder
+}
+
+// static
+constexpr auto InterpreterDispatchDescriptor::registers() {
+  return RegisterArray(
+      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
+      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister);
+}
+
+// static
+constexpr auto InterpreterPushArgsThenCallDescriptor::registers() {
+  return RegisterArray(a0,   // argument count (not including receiver)
+                       a2,   // address of first argument
+                       a1);  // the target callable to be call
+}
+
+// static
+constexpr auto InterpreterPushArgsThenConstructDescriptor::registers() {
+  return RegisterArray(
+      a0,   // argument count (not including receiver)
+      a4,   // address of the first argument
+      a1,   // constructor to call
+      a3,   // new target
+      a2);  // allocation site feedback if available, undefined otherwise
+}
+
+// static
+constexpr auto ResumeGeneratorDescriptor::registers() {
+  return RegisterArray(a0,   // the value to pass to the generator
+                       a1);  // the JSGeneratorObject to resume
+}
+
+// static
+constexpr auto RunMicrotasksEntryDescriptor::registers() {
+  return RegisterArray(a0, a1);
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TARGET_ARCH_RISCV64
+
+#endif  // V8_CODEGEN_RISCV64_INTERFACE_DESCRIPTORS_RISCV64_INL_H_
diff --git a/chromium/v8/src/codegen/riscv64/interface-descriptors-riscv64.cc b/chromium/v8/src/codegen/riscv64/interface-descriptors-riscv64.cc
deleted file mode 100644
index 23953097cd1..00000000000
--- a/chromium/v8/src/codegen/riscv64/interface-descriptors-riscv64.cc
+++ /dev/null
@@ -1,313 +0,0 @@
-// Copyright 2021 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#if V8_TARGET_ARCH_RISCV64
-
-#include "src/codegen/interface-descriptors.h"
-#include "src/execution/frames.h"
-
-namespace v8 {
-namespace internal {
-
-const Register CallInterfaceDescriptor::ContextRegister() { return cp; }
-
-void CallInterfaceDescriptor::DefaultInitializePlatformSpecific(
-    CallInterfaceDescriptorData* data, int register_parameter_count) {
-  const Register default_stub_registers[] = {a0, a1, a2, a3, a4};
-  CHECK_LE(static_cast<size_t>(register_parameter_count),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(register_parameter_count,
-                                   default_stub_registers);
-}
-
-void WasmI32AtomicWait32Descriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {a0, a1, a2, a3};
-  CHECK_EQ(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void WasmI64AtomicWait32Descriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {a0, a1, a2, a3, a4};
-  CHECK_EQ(static_cast<size_t>(kParameterCount - kStackArgumentsCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount - kStackArgumentsCount,
-                                   default_stub_registers);
-}
-
-void RecordWriteDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {a0, a1, a2, a3, kReturnRegister0};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void EphemeronKeyBarrierDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {a0, a1, a2, a3, kReturnRegister0};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void DynamicCheckMapsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register default_stub_registers[] = {kReturnRegister0, a1, a2, a3, cp};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-const Register LoadDescriptor::ReceiverRegister() { return a1; }
-const Register LoadDescriptor::NameRegister() { return a2; }
-const Register LoadDescriptor::SlotRegister() { return a0; }
-
-const Register LoadWithVectorDescriptor::VectorRegister() { return a3; }
-
-const Register
-LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
-  return a4;
-}
-
-const Register StoreDescriptor::ReceiverRegister() { return a1; }
-const Register StoreDescriptor::NameRegister() { return a2; }
-const Register StoreDescriptor::ValueRegister() { return a0; }
-const Register StoreDescriptor::SlotRegister() { return a4; }
-
-const Register StoreWithVectorDescriptor::VectorRegister() { return a3; }
-
-const Register StoreTransitionDescriptor::SlotRegister() { return a4; }
-const Register StoreTransitionDescriptor::VectorRegister() { return a3; }
-const Register StoreTransitionDescriptor::MapRegister() { return a5; }
-
-const Register ApiGetterDescriptor::HolderRegister() { return a0; }
-const Register ApiGetterDescriptor::CallbackRegister() { return a3; }
-
-const Register GrowArrayElementsDescriptor::ObjectRegister() { return a0; }
-const Register GrowArrayElementsDescriptor::KeyRegister() { return a3; }
-
-// static
-const Register TypeConversionDescriptor::ArgumentRegister() { return a0; }
-
-void TypeofDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {a3};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1: target
-  // a0: number of arguments
-  Register registers[] = {a1, a0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a0 : number of arguments (on the stack, not including receiver)
-  // a1 : the target to call
-  // a4 : arguments list length (untagged)
-  // a2 : arguments list (FixedArray)
-  Register registers[] = {a1, a0, a4, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1: the target to call
-  // a0: number of arguments
-  // a2: start index (to support rest parameters)
-  Register registers[] = {a1, a0, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallFunctionTemplateDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1 : function template info
-  // a0 : number of arguments (on the stack, not including receiver)
-  Register registers[] = {a1, a0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a0 : number of arguments (on the stack, not including receiver)
-  // a1 : the target to call
-  // a2 : the object to spread
-  Register registers[] = {a1, a0, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1 : the target to call
-  // a2 : the arguments list
-  Register registers[] = {a1, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a0 : number of arguments (on the stack, not including receiver)
-  // a1 : the target to call
-  // a3 : the new target
-  // a4 : arguments list length (untagged)
-  // a2 : arguments list (FixedArray)
-  Register registers[] = {a1, a3, a0, a4, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1: the target to call
-  // a3: new target
-  // a0: number of arguments
-  // a2: start index (to support rest parameters)
-  Register registers[] = {a1, a3, a0, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a0 : number of arguments (on the stack, not including receiver)
-  // a1 : the target to call
-  // a3 : the new target
-  // a2 : the object to spread
-  Register registers[] = {a1, a3, a0, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1 : the target to call
-  // a3 : the new target
-  // a2 : the arguments list
-  Register registers[] = {a1, a3, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructStubDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // a1: target
-  // a3: new target
-  // a0: number of arguments
-  // a2: allocation site or undefined
-  Register registers[] = {a1, a3, a0, a2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void AbortDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {a0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CompareDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {a1, a0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void BinaryOpDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {a1, a0};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ApiCallbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      a1,  // kApiFunctionAddress
-      a2,  // kArgc
-      a3,  // kCallData
-      a0,  // kHolder
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterDispatchDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
-      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenCallDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      a0,  // argument count (not including receiver)
-      a2,  // address of first argument
-      a1   // the target callable to be call
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenConstructDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      a0,  // argument count (not including receiver)
-      a4,  // address of the first argument
-      a1,  // constructor to call
-      a3,  // new target
-      a2,  // allocation site feedback if available, undefined otherwise
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ResumeGeneratorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      a0,  // the value to pass to the generator
-      a1   // the JSGeneratorObject to resume
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void BinaryOp_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // TODO(v8:11421): Implement on this platform.
-  InitializePlatformUnimplemented(data, kParameterCount);
-}
-
-void Compare_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // TODO(v8:11421): Implement on this platform.
-  InitializePlatformUnimplemented(data, kParameterCount);
-}
-
-void FrameDropperTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      a1,  // loaded new FP
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void RunMicrotasksEntryDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {a0, a1};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_TARGET_ARCH_RISCV64
diff --git a/chromium/v8/src/codegen/riscv64/macro-assembler-riscv64.cc b/chromium/v8/src/codegen/riscv64/macro-assembler-riscv64.cc
index ff798da0e9f..801a74f5698 100644
--- a/chromium/v8/src/codegen/riscv64/macro-assembler-riscv64.cc
+++ b/chromium/v8/src/codegen/riscv64/macro-assembler-riscv64.cc
@@ -12,6 +12,7 @@
 #include "src/codegen/callable.h"
 #include "src/codegen/code-factory.h"
 #include "src/codegen/external-reference-table.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/macro-assembler.h"
 #include "src/codegen/register-configuration.h"
 #include "src/debug/debug.h"
@@ -61,7 +62,7 @@ int TurboAssembler::RequiredStackSizeForCallerSaved(SaveFPRegsMode fp_mode,
   RegList list = kJSCallerSaved & ~exclusions;
   bytes += NumRegs(list) * kPointerSize;
 
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     bytes += NumRegs(kCallerSavedFPU) * kDoubleSize;
   }
 
@@ -86,7 +87,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
   MultiPush(list);
   bytes += NumRegs(list) * kPointerSize;
 
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     MultiPushFPU(kCallerSavedFPU);
     bytes += NumRegs(kCallerSavedFPU) * kDoubleSize;
   }
@@ -97,7 +98,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
 int TurboAssembler::PopCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
                                    Register exclusion2, Register exclusion3) {
   int bytes = 0;
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     MultiPopFPU(kCallerSavedFPU);
     bytes += NumRegs(kCallerSavedFPU) * kDoubleSize;
   }
@@ -175,7 +176,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   Label done;
 
   // Skip barrier if writing a smi.
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     JumpIfSmi(value, &done);
   }
 
@@ -184,7 +185,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   DCHECK(IsAligned(offset, kPointerSize));
 
   Add64(dst, object, Operand(offset - kHeapObjectTag));
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     UseScratchRegisterScope temps(this);
     Register scratch = temps.Acquire();
     BlockTrampolinePoolScope block_trampoline_pool(this);
@@ -197,13 +198,13 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   }
 
   RecordWrite(object, dst, value, ra_status, save_fp, remembered_set_action,
-              OMIT_SMI_CHECK);
+              SmiCheck::kOmit);
 
   bind(&done);
 
   // Clobber clobbered input registers when running with the debug-code flag
   // turned on to provoke errors.
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     li(value, Operand(bit_cast<int64_t>(kZapValue + 4)));
     li(dst, Operand(bit_cast<int64_t>(kZapValue + 8)));
   }
@@ -336,14 +337,14 @@ void MacroAssembler::RecordWrite(Register object, Register address,
                                  SaveFPRegsMode fp_mode,
                                  RememberedSetAction remembered_set_action,
                                  SmiCheck smi_check) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     DCHECK(!AreAliased(object, address, value, kScratchReg));
     Ld(kScratchReg, MemOperand(address));
     Assert(eq, AbortReason::kWrongAddressOrValuePassedToRecordWrite,
            kScratchReg, Operand(value));
   }
 
-  if ((remembered_set_action == OMIT_REMEMBERED_SET &&
+  if ((remembered_set_action == RememberedSetAction::kOmit &&
        !FLAG_incremental_marking) ||
       FLAG_disable_write_barriers) {
     return;
@@ -353,7 +354,7 @@ void MacroAssembler::RecordWrite(Register object, Register address,
   // catch stores of smis and stores into the young generation.
   Label done;
 
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     DCHECK_EQ(0, kSmiTag);
     JumpIfSmi(value, &done);
   }
@@ -378,7 +379,7 @@ void MacroAssembler::RecordWrite(Register object, Register address,
 
   // Clobber clobbered registers when running with the debug-code flag
   // turned on to provoke errors.
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     li(address, Operand(bit_cast<int64_t>(kZapValue + 12)));
     li(value, Operand(bit_cast<int64_t>(kZapValue + 16)));
   }
@@ -393,6 +394,10 @@ void TurboAssembler::Add32(Register rd, Register rs, const Operand& rt) {
   } else {
     if (is_int12(rt.immediate()) && !MustUseReg(rt.rmode())) {
       addiw(rd, rs, static_cast<int32_t>(rt.immediate()));
+    } else if ((-4096 <= rt.immediate() && rt.immediate() <= -2049) ||
+               (2048 <= rt.immediate() && rt.immediate() <= 4094)) {
+      addiw(rd, rs, rt.immediate() / 2);
+      addiw(rd, rd, rt.immediate() - (rt.immediate() / 2));
     } else {
       // li handles the relocation.
       UseScratchRegisterScope temps(this);
@@ -409,6 +414,10 @@ void TurboAssembler::Add64(Register rd, Register rs, const Operand& rt) {
   } else {
     if (is_int12(rt.immediate()) && !MustUseReg(rt.rmode())) {
       addi(rd, rs, static_cast<int32_t>(rt.immediate()));
+    } else if ((-4096 <= rt.immediate() && rt.immediate() <= -2049) ||
+               (2048 <= rt.immediate() && rt.immediate() <= 4094)) {
+      addi(rd, rs, rt.immediate() / 2);
+      addi(rd, rd, rt.immediate() - (rt.immediate() / 2));
     } else {
       // li handles the relocation.
       UseScratchRegisterScope temps(this);
@@ -429,6 +438,10 @@ void TurboAssembler::Sub32(Register rd, Register rs, const Operand& rt) {
       addiw(rd, rs,
             static_cast<int32_t>(
                 -rt.immediate()));  // No subiw instr, use addiw(x, y, -imm).
+    } else if ((-4096 <= -rt.immediate() && -rt.immediate() <= -2049) ||
+               (2048 <= -rt.immediate() && -rt.immediate() <= 4094)) {
+      addiw(rd, rs, -rt.immediate() / 2);
+      addiw(rd, rd, -rt.immediate() - (-rt.immediate() / 2));
     } else {
       UseScratchRegisterScope temps(this);
       Register scratch = temps.Acquire();
@@ -452,6 +465,10 @@ void TurboAssembler::Sub64(Register rd, Register rs, const Operand& rt) {
     addi(rd, rs,
          static_cast<int32_t>(
              -rt.immediate()));  // No subi instr, use addi(x, y, -imm).
+  } else if ((-4096 <= -rt.immediate() && -rt.immediate() <= -2049) ||
+             (2048 <= -rt.immediate() && -rt.immediate() <= 4094)) {
+    addi(rd, rs, -rt.immediate() / 2);
+    addi(rd, rd, -rt.immediate() - (-rt.immediate() / 2));
   } else {
     int li_count = InstrCountForLi64Bit(rt.immediate());
     int li_neg_count = InstrCountForLi64Bit(-rt.immediate());
@@ -884,6 +901,7 @@ void TurboAssembler::Sll64(Register rd, Register rs, const Operand& rt) {
 void TurboAssembler::Ror(Register rd, Register rs, const Operand& rt) {
   UseScratchRegisterScope temps(this);
   Register scratch = temps.Acquire();
+  BlockTrampolinePoolScope block_trampoline_pool(this);
   if (rt.is_reg()) {
     negw(scratch, rt.rm());
     sllw(scratch, rs, scratch);
@@ -908,6 +926,7 @@ void TurboAssembler::Ror(Register rd, Register rs, const Operand& rt) {
 void TurboAssembler::Dror(Register rd, Register rs, const Operand& rt) {
   UseScratchRegisterScope temps(this);
   Register scratch = temps.Acquire();
+  BlockTrampolinePoolScope block_trampoline_pool(this);
   if (rt.is_reg()) {
     negw(scratch, rt.rm());
     sll(scratch, rs, scratch);
@@ -928,9 +947,10 @@ void TurboAssembler::Dror(Register rd, Register rs, const Operand& rt) {
 }
 
 void TurboAssembler::CalcScaledAddress(Register rd, Register rt, Register rs,
-                                       uint8_t sa, Register scratch) {
+                                       uint8_t sa) {
   DCHECK(sa >= 1 && sa <= 31);
-  Register tmp = rd == rt ? scratch : rd;
+  UseScratchRegisterScope temps(this);
+  Register tmp = rd == rt ? temps.Acquire() : rd;
   DCHECK(tmp != rt);
   slli(tmp, rs, sa);
   Add64(rd, rt, tmp);
@@ -1215,8 +1235,9 @@ void TurboAssembler::Uld(Register rd, const MemOperand& rs) {
 // Load consequent 32-bit word pair in 64-bit reg. and put first word in low
 // bits,
 // second word in high bits.
-void MacroAssembler::LoadWordPair(Register rd, const MemOperand& rs,
-                                  Register scratch) {
+void MacroAssembler::LoadWordPair(Register rd, const MemOperand& rs) {
+  UseScratchRegisterScope temps(this);
+  Register scratch = temps.Acquire();
   Lwu(rd, rs);
   Lw(scratch, MemOperand(rs.rm(), rs.offset() + kPointerSize / 2));
   slli(scratch, scratch, 32);
@@ -1228,8 +1249,9 @@ void TurboAssembler::Usd(Register rd, const MemOperand& rs) {
 }
 
 // Do 64-bit store as two consequent 32-bit stores to unaligned address.
-void MacroAssembler::StoreWordPair(Register rd, const MemOperand& rs,
-                                   Register scratch) {
+void MacroAssembler::StoreWordPair(Register rd, const MemOperand& rs) {
+  UseScratchRegisterScope temps(this);
+  Register scratch = temps.Acquire();
   Sw(rd, rs);
   srai(scratch, rd, 32);
   Sw(scratch, MemOperand(rs.rm(), rs.offset() + kPointerSize / 2));
@@ -1464,7 +1486,7 @@ void TurboAssembler::li(Register rd, Operand j, LiFlags mode) {
     UseScratchRegisterScope temps(this);
     int count = li_estimate(j.immediate(), temps.hasAvailable());
     int reverse_count = li_estimate(~j.immediate(), temps.hasAvailable());
-    if (!FLAG_disable_riscv_constant_pool && count >= 4 && reverse_count >= 4) {
+    if (FLAG_riscv_constant_pool && count >= 4 && reverse_count >= 4) {
       // Ld a Address from a constant pool.
       RecordEntry((uint64_t)j.immediate(), j.rmode());
       auipc(rd, 0);
@@ -1864,6 +1886,28 @@ void TurboAssembler::RoundHelper(FPURegister dst, FPURegister src,
       fmv_s(dst, src);
     }
   }
+  {
+    Label not_NaN;
+    UseScratchRegisterScope temps2(this);
+    Register scratch = temps2.Acquire();
+    // According to the wasm spec
+    // (https://webassembly.github.io/spec/core/exec/numerics.html#aux-nans)
+    // if input is canonical NaN, then output is canonical NaN, and if input is
+    // any other NaN, then output is any NaN with most significant bit of
+    // payload is 1. In RISC-V, feq_d will set scratch to 0 if src is a NaN. If
+    // src is not a NaN, branch to the label and do nothing, but if it is,
+    // fmin_d will set dst to the canonical NaN.
+    if (std::is_same<F, double>::value) {
+      feq_d(scratch, src, src);
+      bnez(scratch, &not_NaN);
+      fmin_d(dst, src, src);
+    } else {
+      feq_s(scratch, src, src);
+      bnez(scratch, &not_NaN);
+      fmin_s(dst, src, src);
+    }
+    bind(&not_NaN);
+  }
 
   // If real exponent (i.e., t6 - kFloatExponentBias) is greater than
   // kFloat32MantissaBits, it means the floating-point value has no fractional
@@ -2030,8 +2074,8 @@ void TurboAssembler::CompareF64(Register rd, FPUCondition cc, FPURegister cmp1,
   }
 }
 
-void TurboAssembler::CompareIsNanF32(Register rd, FPURegister cmp1,
-                                     FPURegister cmp2) {
+void TurboAssembler::CompareIsNotNanF32(Register rd, FPURegister cmp1,
+                                        FPURegister cmp2) {
   UseScratchRegisterScope temps(this);
   BlockTrampolinePoolScope block_trampoline_pool(this);
   Register scratch = temps.Acquire();
@@ -2039,11 +2083,10 @@ void TurboAssembler::CompareIsNanF32(Register rd, FPURegister cmp1,
   feq_s(rd, cmp1, cmp1);       // rd <- !isNan(cmp1)
   feq_s(scratch, cmp2, cmp2);  // scratch <- !isNaN(cmp2)
   And(rd, rd, scratch);        // rd <- !isNan(cmp1) && !isNan(cmp2)
-  Xor(rd, rd, 1);              // rd <- isNan(cmp1) || isNan(cmp2)
 }
 
-void TurboAssembler::CompareIsNanF64(Register rd, FPURegister cmp1,
-                                     FPURegister cmp2) {
+void TurboAssembler::CompareIsNotNanF64(Register rd, FPURegister cmp1,
+                                        FPURegister cmp2) {
   UseScratchRegisterScope temps(this);
   BlockTrampolinePoolScope block_trampoline_pool(this);
   Register scratch = temps.Acquire();
@@ -2051,7 +2094,18 @@ void TurboAssembler::CompareIsNanF64(Register rd, FPURegister cmp1,
   feq_d(rd, cmp1, cmp1);       // rd <- !isNan(cmp1)
   feq_d(scratch, cmp2, cmp2);  // scratch <- !isNaN(cmp2)
   And(rd, rd, scratch);        // rd <- !isNan(cmp1) && !isNan(cmp2)
-  Xor(rd, rd, 1);              // rd <- isNan(cmp1) || isNan(cmp2)
+}
+
+void TurboAssembler::CompareIsNanF32(Register rd, FPURegister cmp1,
+                                     FPURegister cmp2) {
+  CompareIsNotNanF32(rd, cmp1, cmp2);  // rd <- !isNan(cmp1) && !isNan(cmp2)
+  Xor(rd, rd, 1);                      // rd <- isNan(cmp1) || isNan(cmp2)
+}
+
+void TurboAssembler::CompareIsNanF64(Register rd, FPURegister cmp1,
+                                     FPURegister cmp2) {
+  CompareIsNotNanF64(rd, cmp1, cmp2);  // rd <- !isNan(cmp1) && !isNan(cmp2)
+  Xor(rd, rd, 1);                      // rd <- isNan(cmp1) || isNan(cmp2)
 }
 
 void TurboAssembler::BranchTrueShortF(Register rs, Label* target) {
@@ -2949,9 +3003,20 @@ void TurboAssembler::Jump(Handle<Code> code, RelocInfo::Mode rmode,
   bool target_is_isolate_independent_builtin =
       isolate()->builtins()->IsBuiltinHandle(code, &builtin_index) &&
       Builtins::IsIsolateIndependent(builtin_index);
-
-  if (root_array_available_ && options().isolate_independent_code &&
-      target_is_isolate_independent_builtin) {
+  if (target_is_isolate_independent_builtin &&
+      options().use_pc_relative_calls_and_jumps) {
+    int32_t code_target_index = AddCodeTarget(code);
+    Label skip;
+    BlockTrampolinePoolScope block_trampoline_pool(this);
+    if (cond != al) {
+      Branch(&skip, NegateCondition(cond), rs, rt);
+    }
+    RecordRelocInfo(RelocInfo::RELATIVE_CODE_TARGET);
+    GenPCRelativeJump(t6, code_target_index);
+    bind(&skip);
+    return;
+  } else if (root_array_available_ && options().isolate_independent_code &&
+             target_is_isolate_independent_builtin) {
     int offset = code->builtin_index() * kSystemPointerSize +
                  IsolateData::builtin_entry_table_offset();
     Ld(t6, MemOperand(kRootRegister, offset));
@@ -3017,8 +3082,22 @@ void TurboAssembler::Call(Handle<Code> code, RelocInfo::Mode rmode,
   bool target_is_isolate_independent_builtin =
       isolate()->builtins()->IsBuiltinHandle(code, &builtin_index) &&
       Builtins::IsIsolateIndependent(builtin_index);
-  if (root_array_available_ && options().isolate_independent_code &&
-      target_is_isolate_independent_builtin) {
+  if (target_is_isolate_independent_builtin &&
+      options().use_pc_relative_calls_and_jumps) {
+    int32_t code_target_index = AddCodeTarget(code);
+    Label skip;
+    BlockTrampolinePoolScope block_trampoline_pool(this);
+    RecordCommentForOffHeapTrampoline(builtin_index);
+    if (cond != al) {
+      Branch(&skip, NegateCondition(cond), rs, rt);
+    }
+    RecordRelocInfo(RelocInfo::RELATIVE_CODE_TARGET);
+    GenPCRelativeJumpAndLink(t6, code_target_index);
+    bind(&skip);
+    RecordComment("]");
+    return;
+  } else if (root_array_available_ && options().isolate_independent_code &&
+             target_is_isolate_independent_builtin) {
     int offset = code->builtin_index() * kSystemPointerSize +
                  IsolateData::builtin_entry_table_offset();
     LoadRootRelative(t6, offset);
@@ -3059,6 +3138,46 @@ void TurboAssembler::CallBuiltinByIndex(Register builtin_index) {
   Call(builtin_index);
 }
 
+void TurboAssembler::CallBuiltin(int builtin_index) {
+  DCHECK(Builtins::IsBuiltinId(builtin_index));
+  RecordCommentForOffHeapTrampoline(builtin_index);
+  CHECK_NE(builtin_index, Builtins::kNoBuiltinId);
+  EmbeddedData d = EmbeddedData::FromBlob(isolate());
+  Address entry = d.InstructionStartOfBuiltin(builtin_index);
+  if (options().short_builtin_calls) {
+    Call(entry, RelocInfo::RUNTIME_ENTRY);
+  } else {
+    Call(entry, RelocInfo::OFF_HEAP_TARGET);
+  }
+  RecordComment("]");
+}
+
+void TurboAssembler::TailCallBuiltin(int builtin_index) {
+  DCHECK(Builtins::IsBuiltinId(builtin_index));
+  RecordCommentForOffHeapTrampoline(builtin_index);
+  CHECK_NE(builtin_index, Builtins::kNoBuiltinId);
+  EmbeddedData d = EmbeddedData::FromBlob(isolate());
+  Address entry = d.InstructionStartOfBuiltin(builtin_index);
+  if (options().short_builtin_calls) {
+    Jump(entry, RelocInfo::RUNTIME_ENTRY);
+  } else {
+    Jump(entry, RelocInfo::OFF_HEAP_TARGET);
+  }
+  RecordComment("]");
+}
+
+void TurboAssembler::LoadEntryFromBuiltinIndex(Builtins::Name builtin_index,
+                                               Register destination) {
+  Ld(destination, EntryFromBuiltinIndexAsOperand(builtin_index));
+}
+
+MemOperand TurboAssembler::EntryFromBuiltinIndexAsOperand(
+    Builtins::Name builtin_index) {
+  DCHECK(root_array_available());
+  return MemOperand(kRootRegister,
+                    IsolateData::builtin_entry_slot_offset(builtin_index));
+}
+
 void TurboAssembler::PatchAndJump(Address target) {
   UseScratchRegisterScope temps(this);
   Register scratch = temps.Acquire();
@@ -3115,16 +3234,28 @@ void TurboAssembler::Ret(Condition cond, Register rs, const Operand& rt) {
   }
 }
 
+void TurboAssembler::GenPCRelativeJump(Register rd, int64_t imm32) {
+  DCHECK(is_int32(imm32));
+  int32_t Hi20 = (((int32_t)imm32 + 0x800) >> 12);
+  int32_t Lo12 = (int32_t)imm32 << 20 >> 20;
+  auipc(rd, Hi20);  // Read PC + Hi20 into scratch.
+  jr(rd, Lo12);     // jump PC + Hi20 + Lo12
+}
+
+void TurboAssembler::GenPCRelativeJumpAndLink(Register rd, int64_t imm32) {
+  DCHECK(is_int32(imm32));
+  int32_t Hi20 = (((int32_t)imm32 + 0x800) >> 12);
+  int32_t Lo12 = (int32_t)imm32 << 20 >> 20;
+  auipc(rd, Hi20);  // Read PC + Hi20 into scratch.
+  jalr(rd, Lo12);   // jump PC + Hi20 + Lo12
+}
+
 void TurboAssembler::BranchLong(Label* L) {
   // Generate position independent long branch.
   BlockTrampolinePoolScope block_trampoline_pool(this);
   int64_t imm64;
   imm64 = branch_long_offset(L);
-  DCHECK(is_int32(imm64));
-  int32_t Hi20 = (((int32_t)imm64 + 0x800) >> 12);
-  int32_t Lo12 = (int32_t)imm64 << 20 >> 20;
-  auipc(t6, Hi20);  // Read PC + Hi20 into scratch.
-  jr(t6, Lo12);     // jump PC + Hi20 + Lo12
+  GenPCRelativeJump(t6, imm64);
   EmitConstPoolWithJumpIfNeeded();
 }
 
@@ -3133,11 +3264,7 @@ void TurboAssembler::BranchAndLinkLong(Label* L) {
   BlockTrampolinePoolScope block_trampoline_pool(this);
   int64_t imm64;
   imm64 = branch_long_offset(L);
-  DCHECK(is_int32(imm64));
-  int32_t Hi20 = (((int32_t)imm64 + 0x800) >> 12);
-  int32_t Lo12 = (int32_t)imm64 << 20 >> 20;
-  auipc(t6, Hi20);  // Read PC + Hi20 into scratch.
-  jalr(t6, Lo12);   // jump PC + Hi20 + Lo12 and read PC + 4 to ra
+  GenPCRelativeJumpAndLink(t6, imm64);
 }
 
 void TurboAssembler::DropAndRet(int drop) {
@@ -3251,14 +3378,6 @@ void TurboAssembler::Push(Handle<HeapObject> handle) {
   push(scratch);
 }
 
-void MacroAssembler::MaybeDropFrames() {
-  // Check whether we need to drop frames to restart a function on the stack.
-  li(a1, ExternalReference::debug_restart_fp_address(isolate()));
-  Ld(a1, MemOperand(a1));
-  Jump(BUILTIN_CODE(isolate(), FrameDropperTrampoline), RelocInfo::CODE_TARGET,
-       ne, a1, Operand(zero_reg));
-}
-
 // ---------------------------------------------------------------------------
 // Exception handling.
 
@@ -3294,16 +3413,10 @@ void MacroAssembler::PopStackHandler() {
 
 void TurboAssembler::FPUCanonicalizeNaN(const DoubleRegister dst,
                                         const DoubleRegister src) {
-  UseScratchRegisterScope temps(this);
-  Register scratch = temps.Acquire();
-  Label NotNaN;
-
-  fmv_d(dst, src);
-  feq_d(scratch, src, src);
-  bne(scratch, zero_reg, &NotNaN);
-  RV_li(scratch, 0x7ff8000000000000ULL);  // This is the canonical NaN
-  fmv_d_x(dst, scratch);
-  bind(&NotNaN);
+  // Subtracting 0.0 preserves all inputs except for signalling NaNs, which
+  // become quiet NaNs. We use fsub rather than fadd because fsub preserves -0.0
+  // inputs: -0.0 + 0.0 = 0.0, but -0.0 - 0.0 = -0.0.
+  fsub_d(dst, src, kDoubleRegZero);
 }
 
 void TurboAssembler::MovFromFloatResult(const DoubleRegister dst) {
@@ -3414,7 +3527,7 @@ void MacroAssembler::StackOverflowCheck(Register num_args, Register scratch1,
 
 void MacroAssembler::InvokePrologue(Register expected_parameter_count,
                                     Register actual_parameter_count,
-                                    Label* done, InvokeFlag flag) {
+                                    Label* done, InvokeType type) {
   Label regular_invoke;
 
   //  a0: actual arguments count
@@ -3524,9 +3637,9 @@ void MacroAssembler::CheckDebugHook(Register fun, Register new_target,
 void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
                                         Register expected_parameter_count,
                                         Register actual_parameter_count,
-                                        InvokeFlag flag) {
+                                        InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
   DCHECK_EQ(function, a1);
   DCHECK_IMPLIES(new_target.is_valid(), new_target == a3);
 
@@ -3540,17 +3653,19 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
   }
 
   Label done;
-  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, flag);
+  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, type);
   // We call indirectly through the code field in the function to
   // allow recompilation to take effect without changing any of the
   // call sites.
   Register code = kJavaScriptCallCodeStartRegister;
   Ld(code, FieldMemOperand(function, JSFunction::kCodeOffset));
-  if (flag == CALL_FUNCTION) {
-    CallCodeObject(code);
-  } else {
-    DCHECK(flag == JUMP_FUNCTION);
-    JumpCodeObject(code);
+  switch (type) {
+    case InvokeType::kCall:
+      CallCodeObject(code);
+      break;
+    case InvokeType::kJump:
+      JumpCodeObject(code);
+      break;
   }
 
   // Continue here if InvokePrologue does handle the invocation due to
@@ -3560,9 +3675,9 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
 
 void MacroAssembler::InvokeFunctionWithNewTarget(
     Register function, Register new_target, Register actual_parameter_count,
-    InvokeFlag flag) {
+    InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
 
   // Contract with called JS functions requires that function is passed in a1.
   DCHECK_EQ(function, a1);
@@ -3576,15 +3691,15 @@ void MacroAssembler::InvokeFunctionWithNewTarget(
                       SharedFunctionInfo::kFormalParameterCountOffset));
 
   InvokeFunctionCode(a1, new_target, expected_parameter_count,
-                     actual_parameter_count, flag);
+                     actual_parameter_count, type);
 }
 
 void MacroAssembler::InvokeFunction(Register function,
                                     Register expected_parameter_count,
                                     Register actual_parameter_count,
-                                    InvokeFlag flag) {
+                                    InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
 
   // Contract with called JS functions requires that function is passed in a1.
   DCHECK_EQ(function, a1);
@@ -3593,7 +3708,7 @@ void MacroAssembler::InvokeFunction(Register function,
   Ld(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
 
   InvokeFunctionCode(a1, no_reg, expected_parameter_count,
-                     actual_parameter_count, flag);
+                     actual_parameter_count, type);
 }
 
 // ---------------------------------------------------------------------------
@@ -3734,15 +3849,15 @@ void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid) {
 void MacroAssembler::JumpToExternalReference(const ExternalReference& builtin,
                                              bool builtin_exit_frame) {
   PrepareCEntryFunction(builtin);
-  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, kDontSaveFPRegs,
-                                          kArgvOnStack, builtin_exit_frame);
+  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, SaveFPRegsMode::kIgnore,
+                                          ArgvMode::kStack, builtin_exit_frame);
   Jump(code, RelocInfo::CODE_TARGET, al, zero_reg, Operand(zero_reg));
 }
 
 void MacroAssembler::JumpToInstructionStream(Address entry) {
   // Ld a Address from a constant pool.
   // Record a value into constant pool.
-  if (FLAG_disable_riscv_constant_pool) {
+  if (!FLAG_riscv_constant_pool) {
     li(kOffHeapTrampolineRegister, Operand(entry, RelocInfo::OFF_HEAP_TARGET));
   } else {
     RecordEntry(entry, RelocInfo::OFF_HEAP_TARGET);
@@ -3795,7 +3910,7 @@ void TurboAssembler::DebugBreak() { stop(); }
 
 void TurboAssembler::Assert(Condition cc, AbortReason reason, Register rs,
                             Operand rt) {
-  if (emit_debug_code()) Check(cc, reason, rs, rt);
+  if (FLAG_debug_code) Check(cc, reason, rs, rt);
 }
 
 void TurboAssembler::Check(Condition cc, AbortReason reason, Register rs,
@@ -3810,11 +3925,11 @@ void TurboAssembler::Check(Condition cc, AbortReason reason, Register rs,
 void TurboAssembler::Abort(AbortReason reason) {
   Label abort_start;
   bind(&abort_start);
-#ifdef DEBUG
-  const char* msg = GetAbortReason(reason);
-  RecordComment("Abort message: ");
-  RecordComment(msg);
-#endif
+  if (FLAG_code_comments) {
+    const char* msg = GetAbortReason(reason);
+    RecordComment("Abort message: ");
+    RecordComment(msg);
+  }
 
   // Avoid emitting call to builtin if requested.
   if (trap_on_abort()) {
@@ -3882,19 +3997,12 @@ void TurboAssembler::EnterFrame(StackFrame::Type type) {
   UseScratchRegisterScope temps(this);
   Register scratch = temps.Acquire();
   BlockTrampolinePoolScope block_trampoline_pool(this);
-  int stack_offset = -3 * kPointerSize;
-  const int fp_offset = 1 * kPointerSize;
-  addi(sp, sp, stack_offset);
-  stack_offset = -stack_offset - kPointerSize;
-  Sd(ra, MemOperand(sp, stack_offset));
-  stack_offset -= kPointerSize;
-  Sd(fp, MemOperand(sp, stack_offset));
-  stack_offset -= kPointerSize;
-  li(scratch, Operand(StackFrame::TypeToMarker(type)));
-  Sd(scratch, MemOperand(sp, stack_offset));
-  // Adjust FP to point to saved FP.
-  DCHECK_EQ(stack_offset, 0);
-  Add64(fp, sp, Operand(fp_offset));
+  Push(ra, fp);
+  Move(fp, sp);
+  if (!StackFrame::IsJavaScript(type)) {
+    li(scratch, Operand(StackFrame::TypeToMarker(type)));
+    Push(scratch);
+  }
 }
 
 void TurboAssembler::LeaveFrame(StackFrame::Type type) {
@@ -3935,7 +4043,7 @@ void MacroAssembler::EnterExitFrame(bool save_doubles, int stack_space,
   // Set up new frame pointer.
   addi(fp, sp, ExitFrameConstants::kFixedFrameSizeFromFp);
 
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Sd(zero_reg, MemOperand(fp, ExitFrameConstants::kSPOffset));
   }
 
@@ -4011,11 +4119,12 @@ void MacroAssembler::LeaveExitFrame(bool save_doubles, Register argument_count,
      ExternalReference::Create(IsolateAddressId::kContextAddress, isolate()));
   Ld(cp, MemOperand(scratch));
 
-#ifdef DEBUG
-  li(scratch,
-     ExternalReference::Create(IsolateAddressId::kContextAddress, isolate()));
-  Sd(a3, MemOperand(scratch));
-#endif
+  if (FLAG_debug_code) {
+    UseScratchRegisterScope temp(this);
+    Register scratch2 = temp.Acquire();
+    li(scratch2, Operand(Context::kInvalidContext));
+    Sd(scratch2, MemOperand(scratch));
+  }
 
   // Pop the arguments, restore registers, and return.
   mv(sp, fp);  // Respect ABI stack constraint.
@@ -4026,7 +4135,7 @@ void MacroAssembler::LeaveExitFrame(bool save_doubles, Register argument_count,
     if (argument_count_is_length) {
       add(sp, sp, argument_count);
     } else {
-      CalcScaledAddress(sp, sp, argument_count, kPointerSizeLog2, scratch);
+      CalcScaledAddress(sp, sp, argument_count, kPointerSizeLog2);
     }
   }
 
@@ -4054,7 +4163,7 @@ int TurboAssembler::ActivationFrameAlignment() {
 }
 
 void MacroAssembler::AssertStackIsAligned() {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     const int frame_alignment = ActivationFrameAlignment();
     const int frame_alignment_mask = frame_alignment - 1;
 
@@ -4084,22 +4193,24 @@ void TurboAssembler::SmiUntag(Register dst, const MemOperand& src) {
   }
 }
 
-void TurboAssembler::JumpIfSmi(Register value, Label* smi_label,
-                               Register scratch) {
+void TurboAssembler::JumpIfSmi(Register value, Label* smi_label) {
   DCHECK_EQ(0, kSmiTag);
+  UseScratchRegisterScope temps(this);
+  Register scratch = temps.Acquire();
   andi(scratch, value, kSmiTagMask);
   Branch(smi_label, eq, scratch, Operand(zero_reg));
 }
 
-void MacroAssembler::JumpIfNotSmi(Register value, Label* not_smi_label,
-                                  Register scratch) {
+void MacroAssembler::JumpIfNotSmi(Register value, Label* not_smi_label) {
+  UseScratchRegisterScope temps(this);
+  Register scratch = temps.Acquire();
   DCHECK_EQ(0, kSmiTag);
   andi(scratch, value, kSmiTagMask);
   Branch(not_smi_label, ne, scratch, Operand(zero_reg));
 }
 
 void MacroAssembler::AssertNotSmi(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     DCHECK(object != kScratchReg);
     andi(kScratchReg, object, kSmiTagMask);
@@ -4108,7 +4219,7 @@ void MacroAssembler::AssertNotSmi(Register object) {
 }
 
 void MacroAssembler::AssertSmi(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     DCHECK(object != kScratchReg);
     andi(kScratchReg, object, kSmiTagMask);
@@ -4117,7 +4228,7 @@ void MacroAssembler::AssertSmi(Register object) {
 }
 
 void MacroAssembler::AssertConstructor(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     DCHECK(object != kScratchReg);
     BlockTrampolinePoolScope block_trampoline_pool(this);
     STATIC_ASSERT(kSmiTag == 0);
@@ -4134,7 +4245,7 @@ void MacroAssembler::AssertConstructor(Register object) {
 }
 
 void MacroAssembler::AssertFunction(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     BlockTrampolinePoolScope block_trampoline_pool(this);
     STATIC_ASSERT(kSmiTag == 0);
     DCHECK(object != kScratchReg);
@@ -4151,7 +4262,7 @@ void MacroAssembler::AssertFunction(Register object) {
 }
 
 void MacroAssembler::AssertBoundFunction(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     BlockTrampolinePoolScope block_trampoline_pool(this);
     STATIC_ASSERT(kSmiTag == 0);
     DCHECK(object != kScratchReg);
@@ -4165,7 +4276,7 @@ void MacroAssembler::AssertBoundFunction(Register object) {
 }
 
 void MacroAssembler::AssertGeneratorObject(Register object) {
-  if (!emit_debug_code()) return;
+  if (!FLAG_debug_code) return;
   BlockTrampolinePoolScope block_trampoline_pool(this);
   STATIC_ASSERT(kSmiTag == 0);
   DCHECK(object != kScratchReg);
@@ -4193,7 +4304,7 @@ void MacroAssembler::AssertGeneratorObject(Register object) {
 
 void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
                                                      Register scratch) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label done_checking;
     AssertNotSmi(object);
     LoadRoot(scratch, RootIndex::kUndefinedValue);
@@ -4229,11 +4340,11 @@ void TurboAssembler::FloatMinMaxHelper(FPURegister dst, FPURegister src1,
   UseScratchRegisterScope temps(this);
   Register scratch = temps.Acquire();
   if (std::is_same<float, F_TYPE>::value) {
-    CompareIsNanF32(scratch, src1, src2);
+    CompareIsNotNanF32(scratch, src1, src2);
   } else {
-    CompareIsNanF64(scratch, src1, src2);
+    CompareIsNotNanF64(scratch, src1, src2);
   }
-  BranchTrueF(scratch, &nan);
+  BranchFalseF(scratch, &nan);
 
   if (kind == MaxMinKind::kMax) {
     if (std::is_same<float, F_TYPE>::value) {
@@ -4330,11 +4441,9 @@ void TurboAssembler::PrepareCallCFunction(int num_reg_arguments,
 void TurboAssembler::CallCFunction(ExternalReference function,
                                    int num_reg_arguments,
                                    int num_double_arguments) {
-  UseScratchRegisterScope temps(this);
-  Register scratch = temps.Acquire();
   BlockTrampolinePoolScope block_trampoline_pool(this);
-  li(scratch, function);
-  CallCFunctionHelper(scratch, num_reg_arguments, num_double_arguments);
+  li(t6, function);
+  CallCFunctionHelper(t6, num_reg_arguments, num_double_arguments);
 }
 
 void TurboAssembler::CallCFunction(Register function, int num_reg_arguments,
@@ -4363,7 +4472,7 @@ void TurboAssembler::CallCFunctionHelper(Register function,
   // PrepareCallCFunction.
 
 #if V8_HOST_ARCH_RISCV64
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     int frame_alignment = base::OS::ActivationFrameAlignment();
     int frame_alignment_mask = frame_alignment - 1;
     if (frame_alignment > kPointerSize) {
@@ -4387,12 +4496,9 @@ void TurboAssembler::CallCFunctionHelper(Register function,
   // allow preemption, so the return address in the link register
   // stays correct.
   {
-    UseScratchRegisterScope temps(this);
-    Register func_scratch = temps.Acquire();
-    BlockTrampolinePoolScope block_trampoline_pool(this);
-    if (function != func_scratch) {
-      mv(func_scratch, function);
-      function = func_scratch;
+    if (function != t6) {
+      mv(t6, function);
+      function = t6;
     }
 
     // Save the frame pointer and PC so that the stack layout remains
@@ -4401,7 +4507,6 @@ void TurboAssembler::CallCFunctionHelper(Register function,
     // 't' registers are caller-saved so this is safe as a scratch register.
     Register pc_scratch = t1;
     Register scratch = t2;
-    DCHECK(!AreAliased(pc_scratch, scratch, function));
 
     auipc(pc_scratch, 0);
     // TODO(RISCV): Does this need an offset? It seems like this should be the
@@ -4494,12 +4599,10 @@ void TurboAssembler::ResetSpeculationPoisonRegister() {
 void TurboAssembler::CallForDeoptimization(Builtins::Name target, int,
                                            Label* exit, DeoptimizeKind kind,
                                            Label* ret, Label*) {
-  UseScratchRegisterScope temps(this);
   BlockTrampolinePoolScope block_trampoline_pool(this);
-  Register scratch = temps.Acquire();
-  Ld(scratch,
+  Ld(t6,
      MemOperand(kRootRegister, IsolateData::builtin_entry_slot_offset(target)));
-  Call(scratch);
+  Call(t6);
   DCHECK_EQ(SizeOfCodeGeneratedSince(exit),
             (kind == DeoptimizeKind::kLazy)
                 ? Deoptimizer::kLazyDeoptExitSize
diff --git a/chromium/v8/src/codegen/riscv64/macro-assembler-riscv64.h b/chromium/v8/src/codegen/riscv64/macro-assembler-riscv64.h
index b260f1c2009..81e55656066 100644
--- a/chromium/v8/src/codegen/riscv64/macro-assembler-riscv64.h
+++ b/chromium/v8/src/codegen/riscv64/macro-assembler-riscv64.h
@@ -12,6 +12,7 @@
 #include "src/codegen/assembler.h"
 #include "src/codegen/riscv64/assembler-riscv64.h"
 #include "src/common/globals.h"
+#include "src/objects/tagged-index.h"
 
 namespace v8 {
 namespace internal {
@@ -53,8 +54,6 @@ enum LiFlags {
   ADDRESS_LOAD = 2
 };
 
-enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
-enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
 enum RAStatus { kRAHasNotBeenSaved, kRAHasBeenSaved };
 
 Register GetRegisterThatIsNotOneOf(Register reg1, Register reg2 = no_reg,
@@ -166,6 +165,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   // Compare double, if any operand is NaN, result is false except for NE
   void CompareF64(Register rd, FPUCondition cc, FPURegister cmp1,
                   FPURegister cmp2);
+  void CompareIsNotNanF32(Register rd, FPURegister cmp1, FPURegister cmp2);
+  void CompareIsNotNanF64(Register rd, FPURegister cmp1, FPURegister cmp2);
   void CompareIsNanF32(Register rd, FPURegister cmp1, FPURegister cmp2);
   void CompareIsNanF64(Register rd, FPURegister cmp1, FPURegister cmp2);
 
@@ -187,6 +188,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
     li(rd, Operand(j), mode);
   }
 
+  inline void Move(Register output, MemOperand operand) { Ld(output, operand); }
+
   void li(Register dst, Handle<HeapObject> value, LiFlags mode = OPTIMIZE_SIZE);
   void li(Register dst, ExternalReference value, LiFlags mode = OPTIMIZE_SIZE);
   void li(Register dst, const StringConstantBase* string,
@@ -197,6 +200,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void LoadRootRegisterOffset(Register destination, intptr_t offset) override;
   void LoadRootRelative(Register destination, int32_t offset) override;
 
+  inline void GenPCRelativeJump(Register rd, int64_t imm32);
+  inline void GenPCRelativeJumpAndLink(Register rd, int64_t imm32);
 // Jump, Call, and Ret pseudo instructions implementing inter-working.
 #define COND_ARGS                              \
   Condition cond = al, Register rs = zero_reg, \
@@ -223,7 +228,20 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   // Load the builtin given by the Smi in |builtin_index| into the same
   // register.
   void LoadEntryFromBuiltinIndex(Register builtin_index);
+  void LoadEntryFromBuiltinIndex(Builtins::Name builtin_index,
+                                 Register destination);
+  MemOperand EntryFromBuiltinIndexAsOperand(Builtins::Name builtin_index);
   void CallBuiltinByIndex(Register builtin_index) override;
+  void CallBuiltin(Builtins::Name builtin) {
+    // TODO(11527): drop the int overload in favour of the Builtins::Name one.
+    return CallBuiltin(static_cast<int>(builtin));
+  }
+  void CallBuiltin(int builtin_index);
+  void TailCallBuiltin(Builtins::Name builtin) {
+    // TODO(11527): drop the int overload in favour of the Builtins::Name one.
+    return TailCallBuiltin(static_cast<int>(builtin));
+  }
+  void TailCallBuiltin(int builtin_index);
 
   void LoadCodeObjectEntry(Register destination, Register code_object) override;
   void CallCodeObject(Register code_object) override;
@@ -799,7 +817,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void Ceil_s_s(FPURegister fd, FPURegister fs, FPURegister fpu_scratch);
 
   // Jump the register contains a smi.
-  void JumpIfSmi(Register value, Label* smi_label, Register scratch = t3);
+  void JumpIfSmi(Register value, Label* smi_label);
 
   void JumpIfEqual(Register a, int32_t b, Label* dest) {
     Branch(dest, eq, a, Operand(b));
@@ -816,8 +834,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   static int ActivationFrameAlignment();
 
   // Calculated scaled address (rd) as rt + rs << sa
-  void CalcScaledAddress(Register rd, Register rs, Register rt, uint8_t sa,
-                         Register scratch = t3);
+  void CalcScaledAddress(Register rd, Register rs, Register rt, uint8_t sa);
 
   // Compute the start of the generated instruction stream from the current PC.
   // This is an alternative to embedding the {CodeObject} handle as a reference.
@@ -953,8 +970,8 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   void RecordWriteField(
       Register object, int offset, Register value, Register scratch,
       RAStatus ra_status, SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
   // For a given |object| notify the garbage collector that the slot |address|
   // has been written.  |value| is the object being stored. The value and
@@ -962,16 +979,16 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   void RecordWrite(
       Register object, Register address, Register value, RAStatus ra_status,
       SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
   // void Pref(int32_t hint, const MemOperand& rs);
 
   // ---------------------------------------------------------------------------
   // Pseudo-instructions.
 
-  void LoadWordPair(Register rd, const MemOperand& rs, Register scratch = t3);
-  void StoreWordPair(Register rd, const MemOperand& rs, Register scratch = t3);
+  void LoadWordPair(Register rd, const MemOperand& rs);
+  void StoreWordPair(Register rd, const MemOperand& rs);
 
   void Madd_s(FPURegister fd, FPURegister fr, FPURegister fs, FPURegister ft);
   void Madd_d(FPURegister fd, FPURegister fr, FPURegister fs, FPURegister ft);
@@ -1011,7 +1028,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // Invoke the JavaScript function code by either calling or jumping.
   void InvokeFunctionCode(Register function, Register new_target,
                           Register expected_parameter_count,
-                          Register actual_parameter_count, InvokeFlag flag);
+                          Register actual_parameter_count, InvokeType type);
 
   // On function call, call into the debugger if necessary.
   void CheckDebugHook(Register fun, Register new_target,
@@ -1022,12 +1039,9 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // current context to the context in the function before invoking.
   void InvokeFunctionWithNewTarget(Register function, Register new_target,
                                    Register actual_parameter_count,
-                                   InvokeFlag flag);
+                                   InvokeType type);
   void InvokeFunction(Register function, Register expected_parameter_count,
-                      Register actual_parameter_count, InvokeFlag flag);
-
-  // Frame restart support.
-  void MaybeDropFrames();
+                      Register actual_parameter_count, InvokeType type);
 
   // Exception handling.
 
@@ -1051,18 +1065,18 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
 
   // Call a runtime routine.
   void CallRuntime(const Runtime::Function* f, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs);
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore);
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId fid,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     const Runtime::Function* function = Runtime::FunctionForId(fid);
     CallRuntime(function, function->nargs, save_doubles);
   }
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId fid, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     CallRuntime(Runtime::FunctionForId(fid), num_arguments, save_doubles);
   }
 
@@ -1131,8 +1145,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   }
 
   // Jump if the register contains a non-smi.
-  void JumpIfNotSmi(Register value, Label* not_smi_label,
-                    Register scratch = t3);
+  void JumpIfNotSmi(Register value, Label* not_smi_label);
 
   // Abort execution if argument is a smi, enabled via --debug-code.
   void AssertNotSmi(Register object);
@@ -1170,7 +1183,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // Helper functions for generating invokes.
   void InvokePrologue(Register expected_parameter_count,
                       Register actual_parameter_count, Label* done,
-                      InvokeFlag flag);
+                      InvokeType type);
 
   // Compute memory operands for safepoint stack slots.
   static int SafepointRegisterStackIndex(int reg_code);
diff --git a/chromium/v8/src/codegen/riscv64/register-riscv64.h b/chromium/v8/src/codegen/riscv64/register-riscv64.h
index b97594becda..4aacad611dd 100644
--- a/chromium/v8/src/codegen/riscv64/register-riscv64.h
+++ b/chromium/v8/src/codegen/riscv64/register-riscv64.h
@@ -337,7 +337,7 @@ constexpr Register kJavaScriptCallTargetRegister = kJSFunctionRegister;
 constexpr Register kJavaScriptCallNewTargetRegister = a3;
 constexpr Register kJavaScriptCallExtraArg1Register = a2;
 
-constexpr Register kOffHeapTrampolineRegister = t3;
+constexpr Register kOffHeapTrampolineRegister = t6;
 constexpr Register kRuntimeCallFunctionRegister = a1;
 constexpr Register kRuntimeCallArgCountRegister = a0;
 constexpr Register kRuntimeCallArgvRegister = a2;
diff --git a/chromium/v8/src/codegen/s390/assembler-s390.cc b/chromium/v8/src/codegen/s390/assembler-s390.cc
index dd5f59bc0bc..da51395dfd5 100644
--- a/chromium/v8/src/codegen/s390/assembler-s390.cc
+++ b/chromium/v8/src/codegen/s390/assembler-s390.cc
@@ -160,7 +160,11 @@ static bool supportsSTFLE() {
 }
 
 bool CpuFeatures::SupportsWasmSimd128() {
+#if V8_ENABLE_WEBASSEMBLY
   return CpuFeatures::IsSupported(VECTOR_ENHANCE_FACILITY_1);
+#else
+  return false;
+#endif  // V8_ENABLE_WEBASSEMBLY
 }
 
 void CpuFeatures::ProbeImpl(bool cross_compile) {
diff --git a/chromium/v8/src/codegen/s390/interface-descriptors-s390-inl.h b/chromium/v8/src/codegen/s390/interface-descriptors-s390-inl.h
new file mode 100644
index 00000000000..d672c4354dd
--- /dev/null
+++ b/chromium/v8/src/codegen/s390/interface-descriptors-s390-inl.h
@@ -0,0 +1,256 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_CODEGEN_S390_INTERFACE_DESCRIPTORS_S390_INL_H_
+#define V8_CODEGEN_S390_INTERFACE_DESCRIPTORS_S390_INL_H_
+
+#if V8_TARGET_ARCH_S390
+
+#include "src/codegen/interface-descriptors.h"
+#include "src/execution/frames.h"
+
+namespace v8 {
+namespace internal {
+
+constexpr auto CallInterfaceDescriptor::DefaultRegisterArray() {
+  auto registers = RegisterArray(r2, r3, r4, r5, r6);
+  STATIC_ASSERT(registers.size() == kMaxBuiltinRegisterParams);
+  return registers;
+}
+
+// static
+constexpr auto RecordWriteDescriptor::registers() {
+  return RegisterArray(r2, r3, r4, r5, r6, kReturnRegister0);
+}
+
+// static
+constexpr auto DynamicCheckMapsDescriptor::registers() {
+  return RegisterArray(r2, r3, r4, r5, cp);
+}
+
+// static
+constexpr auto EphemeronKeyBarrierDescriptor::registers() {
+  return RegisterArray(r2, r3, r4, r5, r6, kReturnRegister0);
+}
+
+// static
+constexpr Register LoadDescriptor::ReceiverRegister() { return r3; }
+// static
+constexpr Register LoadDescriptor::NameRegister() { return r4; }
+// static
+constexpr Register LoadDescriptor::SlotRegister() { return r2; }
+
+// static
+constexpr Register LoadWithVectorDescriptor::VectorRegister() { return r5; }
+
+// static
+constexpr Register
+LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
+  return r6;
+}
+
+// static
+constexpr Register StoreDescriptor::ReceiverRegister() { return r3; }
+// static
+constexpr Register StoreDescriptor::NameRegister() { return r4; }
+// static
+constexpr Register StoreDescriptor::ValueRegister() { return r2; }
+// static
+constexpr Register StoreDescriptor::SlotRegister() { return r6; }
+
+// static
+constexpr Register StoreWithVectorDescriptor::VectorRegister() { return r5; }
+
+// static
+constexpr Register StoreTransitionDescriptor::MapRegister() { return r7; }
+
+// static
+constexpr Register ApiGetterDescriptor::HolderRegister() { return r2; }
+// static
+constexpr Register ApiGetterDescriptor::CallbackRegister() { return r5; }
+
+// static
+constexpr Register GrowArrayElementsDescriptor::ObjectRegister() { return r2; }
+// static
+constexpr Register GrowArrayElementsDescriptor::KeyRegister() { return r5; }
+
+// static
+constexpr Register BaselineLeaveFrameDescriptor::ParamsSizeRegister() {
+  // TODO(v8:11421): Implement on this platform.
+  return r5;
+}
+// static
+constexpr Register BaselineLeaveFrameDescriptor::WeightRegister() {
+  // TODO(v8:11421): Implement on this platform.
+  return r6;
+}
+
+// static
+// static
+constexpr Register TypeConversionDescriptor::ArgumentRegister() { return r2; }
+
+// static
+constexpr auto TypeofDescriptor::registers() { return RegisterArray(r5); }
+
+// static
+constexpr auto CallTrampolineDescriptor::registers() {
+  // r2 : number of arguments
+  // r3 : the target to call
+  return RegisterArray(r3, r2);
+}
+
+// static
+constexpr auto CallVarargsDescriptor::registers() {
+  // r2 : number of arguments (on the stack, not including receiver)
+  // r3 : the target to call
+  // r6 : arguments list length (untagged)
+  // r4 : arguments list (FixedArray)
+  return RegisterArray(r3, r2, r6, r4);
+}
+
+// static
+constexpr auto CallForwardVarargsDescriptor::registers() {
+  // r2 : number of arguments
+  // r4 : start index (to support rest parameters)
+  // r3 : the target to call
+  return RegisterArray(r3, r2, r4);
+}
+
+// static
+constexpr auto CallFunctionTemplateDescriptor::registers() {
+  // r3 : function template info
+  // r4 : number of arguments (on the stack, not including receiver)
+  return RegisterArray(r3, r4);
+}
+
+// static
+constexpr auto CallWithSpreadDescriptor::registers() {
+  // r2: number of arguments (on the stack, not including receiver)
+  // r3 : the target to call
+  // r4 : the object to spread
+  return RegisterArray(r3, r2, r4);
+}
+
+// static
+constexpr auto CallWithArrayLikeDescriptor::registers() {
+  // r3 : the target to call
+  // r4 : the arguments list
+  return RegisterArray(r3, r4);
+}
+
+// static
+constexpr auto ConstructVarargsDescriptor::registers() {
+  // r2 : number of arguments (on the stack, not including receiver)
+  // r3 : the target to call
+  // r5 : the new target
+  // r6 : arguments list length (untagged)
+  // r4 : arguments list (FixedArray)
+  return RegisterArray(r3, r5, r2, r6, r4);
+}
+
+// static
+constexpr auto ConstructForwardVarargsDescriptor::registers() {
+  // r2 : number of arguments
+  // r5 : the new target
+  // r4 : start index (to support rest parameters)
+  // r3 : the target to call
+  return RegisterArray(r3, r5, r2, r4);
+}
+
+// static
+constexpr auto ConstructWithSpreadDescriptor::registers() {
+  // r2 : number of arguments (on the stack, not including receiver)
+  // r3 : the target to call
+  // r5 : the new target
+  // r4 : the object to spread
+  return RegisterArray(r3, r5, r2, r4);
+}
+
+// static
+constexpr auto ConstructWithArrayLikeDescriptor::registers() {
+  // r3 : the target to call
+  // r5 : the new target
+  // r4 : the arguments list
+  return RegisterArray(r3, r5, r4);
+}
+
+// static
+constexpr auto ConstructStubDescriptor::registers() {
+  // r2 : number of arguments
+  // r3 : the target to call
+  // r5 : the new target
+  // r4 : allocation site or undefined
+  return RegisterArray(r3, r5, r2, r4);
+}
+
+// static
+constexpr auto AbortDescriptor::registers() { return RegisterArray(r3); }
+
+// static
+constexpr auto CompareDescriptor::registers() { return RegisterArray(r3, r2); }
+
+// static
+constexpr auto Compare_BaselineDescriptor::registers() {
+  // TODO(v8:11421): Implement on this platform.
+  return DefaultRegisterArray();
+}
+
+// static
+constexpr auto BinaryOpDescriptor::registers() { return RegisterArray(r3, r2); }
+
+// static
+constexpr auto BinaryOp_BaselineDescriptor::registers() {
+  // TODO(v8:11421): Implement on this platform.
+  return DefaultRegisterArray();
+}
+
+// static
+constexpr auto ApiCallbackDescriptor::registers() {
+  return RegisterArray(r3,   // kApiFunctionAddress
+                       r4,   // kArgc
+                       r5,   // kCallData
+                       r2);  // kHolder
+}
+
+// static
+constexpr auto InterpreterDispatchDescriptor::registers() {
+  return RegisterArray(
+      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
+      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister);
+}
+
+// static
+constexpr auto InterpreterPushArgsThenCallDescriptor::registers() {
+  return RegisterArray(r2,   // argument count (not including receiver)
+                       r4,   // address of first argument
+                       r3);  // the target callable to be call
+}
+
+// static
+constexpr auto InterpreterPushArgsThenConstructDescriptor::registers() {
+  return RegisterArray(
+      r2,   // argument count (not including receiver)
+      r6,   // address of the first argument
+      r3,   // constructor to call
+      r5,   // new target
+      r4);  // allocation site feedback if available, undefined otherwise
+}
+
+// static
+constexpr auto ResumeGeneratorDescriptor::registers() {
+  return RegisterArray(r2,   // the value to pass to the generator
+                       r3);  // the JSGeneratorObject to resume
+}
+
+// static
+constexpr auto RunMicrotasksEntryDescriptor::registers() {
+  return RegisterArray(r2, r3);
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TARGET_ARCH_S390
+
+#endif  // V8_CODEGEN_S390_INTERFACE_DESCRIPTORS_S390_INL_H_
diff --git a/chromium/v8/src/codegen/s390/interface-descriptors-s390.cc b/chromium/v8/src/codegen/s390/interface-descriptors-s390.cc
deleted file mode 100644
index 9a9ecdcb8ba..00000000000
--- a/chromium/v8/src/codegen/s390/interface-descriptors-s390.cc
+++ /dev/null
@@ -1,306 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#if V8_TARGET_ARCH_S390
-
-#include "src/codegen/interface-descriptors.h"
-
-#include "src/execution/frames.h"
-
-namespace v8 {
-namespace internal {
-
-const Register CallInterfaceDescriptor::ContextRegister() { return cp; }
-
-void CallInterfaceDescriptor::DefaultInitializePlatformSpecific(
-    CallInterfaceDescriptorData* data, int register_parameter_count) {
-  const Register default_stub_registers[] = {r2, r3, r4, r5, r6};
-  CHECK_LE(static_cast<size_t>(register_parameter_count),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(register_parameter_count,
-                                   default_stub_registers);
-}
-
-void RecordWriteDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {r2, r3, r4, r5, r6};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void DynamicCheckMapsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register default_stub_registers[] = {r2, r3, r4, r5, cp};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void EphemeronKeyBarrierDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {r2, r3, r4, r5, r6};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-const Register LoadDescriptor::ReceiverRegister() { return r3; }
-const Register LoadDescriptor::NameRegister() { return r4; }
-const Register LoadDescriptor::SlotRegister() { return r2; }
-
-const Register LoadWithVectorDescriptor::VectorRegister() { return r5; }
-
-const Register
-LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
-  return r6;
-}
-
-const Register StoreDescriptor::ReceiverRegister() { return r3; }
-const Register StoreDescriptor::NameRegister() { return r4; }
-const Register StoreDescriptor::ValueRegister() { return r2; }
-const Register StoreDescriptor::SlotRegister() { return r6; }
-
-const Register StoreWithVectorDescriptor::VectorRegister() { return r5; }
-
-const Register StoreTransitionDescriptor::SlotRegister() { return r6; }
-const Register StoreTransitionDescriptor::VectorRegister() { return r5; }
-const Register StoreTransitionDescriptor::MapRegister() { return r7; }
-
-const Register ApiGetterDescriptor::HolderRegister() { return r2; }
-const Register ApiGetterDescriptor::CallbackRegister() { return r5; }
-
-const Register GrowArrayElementsDescriptor::ObjectRegister() { return r2; }
-const Register GrowArrayElementsDescriptor::KeyRegister() { return r5; }
-
-const Register BaselineLeaveFrameDescriptor::ParamsSizeRegister() {
-  // TODO(v8:11421): Implement on this platform.
-  UNREACHABLE();
-}
-const Register BaselineLeaveFrameDescriptor::WeightRegister() {
-  // TODO(v8:11421): Implement on this platform.
-  UNREACHABLE();
-}
-
-// static
-const Register TypeConversionDescriptor::ArgumentRegister() { return r2; }
-
-void TypeofDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {r5};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r2 : number of arguments
-  // r3 : the target to call
-  Register registers[] = {r3, r2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r2 : number of arguments (on the stack, not including receiver)
-  // r3 : the target to call
-  // r6 : arguments list length (untagged)
-  // r4 : arguments list (FixedArray)
-  Register registers[] = {r3, r2, r6, r4};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r2 : number of arguments
-  // r4 : start index (to support rest parameters)
-  // r3 : the target to call
-  Register registers[] = {r3, r2, r4};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallFunctionTemplateDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r3 : function template info
-  // r4 : number of arguments (on the stack, not including receiver)
-  Register registers[] = {r3, r4};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r2 : number of arguments (on the stack, not including receiver)
-  // r3 : the target to call
-  // r4 : the object to spread
-  Register registers[] = {r3, r2, r4};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r3 : the target to call
-  // r4 : the arguments list
-  Register registers[] = {r3, r4};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r2 : number of arguments (on the stack, not including receiver)
-  // r3 : the target to call
-  // r5 : the new target
-  // r6 : arguments list length (untagged)
-  // r4 : arguments list (FixedArray)
-  Register registers[] = {r3, r5, r2, r6, r4};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r2 : number of arguments
-  // r5 : the new target
-  // r4 : start index (to support rest parameters)
-  // r3 : the target to call
-  Register registers[] = {r3, r5, r2, r4};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r2 : number of arguments (on the stack, not including receiver)
-  // r3 : the target to call
-  // r5 : the new target
-  // r4 : the object to spread
-  Register registers[] = {r3, r5, r2, r4};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r3 : the target to call
-  // r5 : the new target
-  // r4 : the arguments list
-  Register registers[] = {r3, r5, r4};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructStubDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // r2 : number of arguments
-  // r3 : the target to call
-  // r5 : the new target
-  // r4 : allocation site or undefined
-  Register registers[] = {r3, r5, r2, r4};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void AbortDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {r3};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CompareDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {r3, r2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void Compare_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // TODO(v8:11421): Implement on this platform.
-  InitializePlatformUnimplemented(data, kParameterCount);
-}
-
-void BinaryOpDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {r3, r2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void BinaryOp_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // TODO(v8:11421): Implement on this platform.
-  InitializePlatformUnimplemented(data, kParameterCount);
-}
-
-void ApiCallbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      r3,  // kApiFunctionAddress
-      r4,  // kArgc
-      r5,  // kCallData
-      r2,  // kHolder
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterDispatchDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
-      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenCallDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      r2,  // argument count (not including receiver)
-      r4,  // address of first argument
-      r3   // the target callable to be call
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenConstructDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      r2,  // argument count (not including receiver)
-      r6,  // address of the first argument
-      r3,  // constructor to call
-      r5,  // new target
-      r4,  // allocation site feedback if available, undefined otherwise
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ResumeGeneratorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      r2,  // the value to pass to the generator
-      r3   // the JSGeneratorObject to resume
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void FrameDropperTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      r3,  // loaded new FP
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void RunMicrotasksEntryDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {r2, r3};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_TARGET_ARCH_S390
diff --git a/chromium/v8/src/codegen/s390/macro-assembler-s390.cc b/chromium/v8/src/codegen/s390/macro-assembler-s390.cc
index be5798d8d4f..de25a93d8b3 100644
--- a/chromium/v8/src/codegen/s390/macro-assembler-s390.cc
+++ b/chromium/v8/src/codegen/s390/macro-assembler-s390.cc
@@ -12,6 +12,7 @@
 #include "src/codegen/callable.h"
 #include "src/codegen/code-factory.h"
 #include "src/codegen/external-reference-table.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/macro-assembler.h"
 #include "src/codegen/register-configuration.h"
 #include "src/debug/debug.h"
@@ -40,6 +41,12 @@ namespace internal {
 void TurboAssembler::DoubleMax(DoubleRegister result_reg,
                                DoubleRegister left_reg,
                                DoubleRegister right_reg) {
+  if (CpuFeatures::IsSupported(VECTOR_ENHANCE_FACILITY_1)) {
+    vfmax(result_reg, left_reg, right_reg, Condition(1), Condition(8),
+          Condition(3));
+    return;
+  }
+
   Label check_zero, return_left, return_right, return_nan, done;
   cdbr(left_reg, right_reg);
   bunordered(&return_nan, Label::kNear);
@@ -80,6 +87,11 @@ void TurboAssembler::DoubleMax(DoubleRegister result_reg,
 void TurboAssembler::DoubleMin(DoubleRegister result_reg,
                                DoubleRegister left_reg,
                                DoubleRegister right_reg) {
+  if (CpuFeatures::IsSupported(VECTOR_ENHANCE_FACILITY_1)) {
+    vfmin(result_reg, left_reg, right_reg, Condition(1), Condition(8),
+          Condition(3));
+    return;
+  }
   Label check_zero, return_left, return_right, return_nan, done;
   cdbr(left_reg, right_reg);
   bunordered(&return_nan, Label::kNear);
@@ -126,6 +138,11 @@ void TurboAssembler::DoubleMin(DoubleRegister result_reg,
 void TurboAssembler::FloatMax(DoubleRegister result_reg,
                               DoubleRegister left_reg,
                               DoubleRegister right_reg) {
+  if (CpuFeatures::IsSupported(VECTOR_ENHANCE_FACILITY_1)) {
+    vfmax(result_reg, left_reg, right_reg, Condition(1), Condition(8),
+          Condition(2));
+    return;
+  }
   Label check_zero, return_left, return_right, return_nan, done;
   cebr(left_reg, right_reg);
   bunordered(&return_nan, Label::kNear);
@@ -166,6 +183,12 @@ void TurboAssembler::FloatMax(DoubleRegister result_reg,
 void TurboAssembler::FloatMin(DoubleRegister result_reg,
                               DoubleRegister left_reg,
                               DoubleRegister right_reg) {
+  if (CpuFeatures::IsSupported(VECTOR_ENHANCE_FACILITY_1)) {
+    vfmin(result_reg, left_reg, right_reg, Condition(1), Condition(8),
+          Condition(2));
+    return;
+  }
+
   Label check_zero, return_left, return_right, return_nan, done;
   cebr(left_reg, right_reg);
   bunordered(&return_nan, Label::kNear);
@@ -208,6 +231,39 @@ void TurboAssembler::FloatMin(DoubleRegister result_reg,
   }
   bind(&done);
 }
+
+void TurboAssembler::CeilF32(DoubleRegister dst, DoubleRegister src) {
+  fiebra(ROUND_TOWARD_POS_INF, dst, src);
+}
+
+void TurboAssembler::CeilF64(DoubleRegister dst, DoubleRegister src) {
+  fidbra(ROUND_TOWARD_POS_INF, dst, src);
+}
+
+void TurboAssembler::FloorF32(DoubleRegister dst, DoubleRegister src) {
+  fiebra(ROUND_TOWARD_NEG_INF, dst, src);
+}
+
+void TurboAssembler::FloorF64(DoubleRegister dst, DoubleRegister src) {
+  fidbra(ROUND_TOWARD_NEG_INF, dst, src);
+}
+
+void TurboAssembler::TruncF32(DoubleRegister dst, DoubleRegister src) {
+  fiebra(ROUND_TOWARD_0, dst, src);
+}
+
+void TurboAssembler::TruncF64(DoubleRegister dst, DoubleRegister src) {
+  fidbra(ROUND_TOWARD_0, dst, src);
+}
+
+void TurboAssembler::NearestIntF32(DoubleRegister dst, DoubleRegister src) {
+  fiebra(ROUND_TO_NEAREST_TO_EVEN, dst, src);
+}
+
+void TurboAssembler::NearestIntF64(DoubleRegister dst, DoubleRegister src) {
+  fidbra(ROUND_TO_NEAREST_TO_EVEN, dst, src);
+}
+
 int TurboAssembler::RequiredStackSizeForCallerSaved(SaveFPRegsMode fp_mode,
                                                     Register exclusion1,
                                                     Register exclusion2,
@@ -227,7 +283,7 @@ int TurboAssembler::RequiredStackSizeForCallerSaved(SaveFPRegsMode fp_mode,
   RegList list = kJSCallerSaved & ~exclusions;
   bytes += NumRegs(list) * kSystemPointerSize;
 
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     bytes += NumRegs(kCallerSavedDoubles) * kDoubleSize;
   }
 
@@ -252,7 +308,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
   MultiPush(list);
   bytes += NumRegs(list) * kSystemPointerSize;
 
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     MultiPushDoubles(kCallerSavedDoubles);
     bytes += NumRegs(kCallerSavedDoubles) * kDoubleSize;
   }
@@ -263,7 +319,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
 int TurboAssembler::PopCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
                                    Register exclusion2, Register exclusion3) {
   int bytes = 0;
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     MultiPopDoubles(kCallerSavedDoubles);
     bytes += NumRegs(kCallerSavedDoubles) * kDoubleSize;
   }
@@ -759,7 +815,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   Label done;
 
   // Skip barrier if writing a smi.
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     JumpIfSmi(value, &done);
   }
 
@@ -768,7 +824,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   DCHECK(IsAligned(offset, kTaggedSize));
 
   lay(dst, MemOperand(object, offset - kHeapObjectTag));
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label ok;
     AndP(r0, dst, Operand(kTaggedSize - 1));
     beq(&ok, Label::kNear);
@@ -777,13 +833,13 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   }
 
   RecordWrite(object, dst, value, lr_status, save_fp, remembered_set_action,
-              OMIT_SMI_CHECK);
+              SmiCheck::kOmit);
 
   bind(&done);
 
   // Clobber clobbered input registers when running with the debug-code flag
   // turned on to provoke errors.
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     mov(value, Operand(bit_cast<intptr_t>(kZapValue + 4)));
     mov(dst, Operand(bit_cast<intptr_t>(kZapValue + 8)));
   }
@@ -911,13 +967,13 @@ void MacroAssembler::RecordWrite(Register object, Register address,
                                  RememberedSetAction remembered_set_action,
                                  SmiCheck smi_check) {
   DCHECK(object != value);
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     LoadTaggedPointerField(r0, MemOperand(address));
     CmpS64(value, r0);
     Check(eq, AbortReason::kWrongAddressOrValuePassedToRecordWrite);
   }
 
-  if ((remembered_set_action == OMIT_REMEMBERED_SET &&
+  if ((remembered_set_action == RememberedSetAction::kOmit &&
        !FLAG_incremental_marking) ||
       FLAG_disable_write_barriers) {
     return;
@@ -926,7 +982,7 @@ void MacroAssembler::RecordWrite(Register object, Register address,
   // catch stores of smis and stores into the young generation.
   Label done;
 
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     JumpIfSmi(value, &done);
   }
 
@@ -950,7 +1006,7 @@ void MacroAssembler::RecordWrite(Register object, Register address,
 
   // Clobber clobbered registers when running with the debug-code flag
   // turned on to provoke errors.
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     mov(address, Operand(bit_cast<intptr_t>(kZapValue + 12)));
     mov(value, Operand(bit_cast<intptr_t>(kZapValue + 16)));
   }
@@ -1352,7 +1408,7 @@ void MacroAssembler::EnterExitFrame(bool save_doubles, int stack_space,
   // Reserve room for saved entry sp.
   lay(sp, MemOperand(fp, -ExitFrameConstants::kFixedFrameSizeFromFp));
 
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     StoreU64(MemOperand(fp, ExitFrameConstants::kSPOffset), Operand::Zero(),
              r1);
   }
@@ -1537,7 +1593,7 @@ void MacroAssembler::StackOverflowCheck(Register num_args, Register scratch,
 
 void MacroAssembler::InvokePrologue(Register expected_parameter_count,
                                     Register actual_parameter_count,
-                                    Label* done, InvokeFlag flag) {
+                                    Label* done, InvokeType type) {
   Label regular_invoke;
 
   //  r2: actual arguments count
@@ -1653,9 +1709,9 @@ void MacroAssembler::CheckDebugHook(Register fun, Register new_target,
 void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
                                         Register expected_parameter_count,
                                         Register actual_parameter_count,
-                                        InvokeFlag flag) {
+                                        InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
   DCHECK_EQ(function, r3);
   DCHECK_IMPLIES(new_target.is_valid(), new_target == r5);
 
@@ -1669,18 +1725,20 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
   }
 
   Label done;
-  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, flag);
+  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, type);
   // We call indirectly through the code field in the function to
   // allow recompilation to take effect without changing any of the
   // call sites.
   Register code = kJavaScriptCallCodeStartRegister;
   LoadTaggedPointerField(code,
                          FieldMemOperand(function, JSFunction::kCodeOffset));
-  if (flag == CALL_FUNCTION) {
-    CallCodeObject(code);
-  } else {
-    DCHECK(flag == JUMP_FUNCTION);
-    JumpCodeObject(code);
+  switch (type) {
+    case InvokeType::kCall:
+      CallCodeObject(code);
+      break;
+    case InvokeType::kJump:
+      JumpCodeObject(code);
+      break;
   }
   // Continue here if InvokePrologue does handle the invocation due to
   // mismatched parameter counts.
@@ -1689,9 +1747,9 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
 
 void MacroAssembler::InvokeFunctionWithNewTarget(
     Register fun, Register new_target, Register actual_parameter_count,
-    InvokeFlag flag) {
+    InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
 
   // Contract with called JS functions requires that function is passed in r3.
   DCHECK_EQ(fun, r3);
@@ -1707,15 +1765,15 @@ void MacroAssembler::InvokeFunctionWithNewTarget(
                       SharedFunctionInfo::kFormalParameterCountOffset));
 
   InvokeFunctionCode(fun, new_target, expected_reg, actual_parameter_count,
-                     flag);
+                     type);
 }
 
 void MacroAssembler::InvokeFunction(Register function,
                                     Register expected_parameter_count,
                                     Register actual_parameter_count,
-                                    InvokeFlag flag) {
+                                    InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
 
   // Contract with called JS functions requires that function is passed in r3.
   DCHECK_EQ(function, r3);
@@ -1725,18 +1783,7 @@ void MacroAssembler::InvokeFunction(Register function,
                          FieldMemOperand(function, JSFunction::kContextOffset));
 
   InvokeFunctionCode(r3, no_reg, expected_parameter_count,
-                     actual_parameter_count, flag);
-}
-
-void MacroAssembler::MaybeDropFrames() {
-  // Check whether we need to drop frames to restart a function on the stack.
-  ExternalReference restart_fp =
-      ExternalReference::debug_restart_fp_address(isolate());
-  Move(r3, restart_fp);
-  LoadU64(r3, MemOperand(r3));
-  CmpS64(r3, Operand::Zero());
-  Jump(BUILTIN_CODE(isolate(), FrameDropperTrampoline), RelocInfo::CODE_TARGET,
-       ne);
+                     actual_parameter_count, type);
 }
 
 void MacroAssembler::PushStackHandler() {
@@ -1904,8 +1951,8 @@ void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid) {
 void MacroAssembler::JumpToExternalReference(const ExternalReference& builtin,
                                              bool builtin_exit_frame) {
   Move(r3, builtin);
-  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, kDontSaveFPRegs,
-                                          kArgvOnStack, builtin_exit_frame);
+  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, SaveFPRegsMode::kIgnore,
+                                          ArgvMode::kStack, builtin_exit_frame);
   Jump(code, RelocInfo::CODE_TARGET);
 }
 
@@ -1947,11 +1994,11 @@ void MacroAssembler::DecrementCounter(StatsCounter* counter, int value,
 }
 
 void TurboAssembler::Assert(Condition cond, AbortReason reason, CRegister cr) {
-  if (emit_debug_code()) Check(cond, reason, cr);
+  if (FLAG_debug_code) Check(cond, reason, cr);
 }
 
 void TurboAssembler::AssertUnreachable(AbortReason reason) {
-  if (emit_debug_code()) Abort(reason);
+  if (FLAG_debug_code) Abort(reason);
 }
 
 void TurboAssembler::Check(Condition cond, AbortReason reason, CRegister cr) {
@@ -1965,11 +2012,11 @@ void TurboAssembler::Check(Condition cond, AbortReason reason, CRegister cr) {
 void TurboAssembler::Abort(AbortReason reason) {
   Label abort_start;
   bind(&abort_start);
-#ifdef DEBUG
-  const char* msg = GetAbortReason(reason);
-  RecordComment("Abort message: ");
-  RecordComment(msg);
-#endif
+  if (FLAG_code_comments) {
+    const char* msg = GetAbortReason(reason);
+    RecordComment("Abort message: ");
+    RecordComment(msg);
+  }
 
   // Avoid emitting call to builtin if requested.
   if (trap_on_abort()) {
@@ -2017,7 +2064,7 @@ void MacroAssembler::LoadNativeContextSlot(Register dst, int index) {
 }
 
 void MacroAssembler::AssertNotSmi(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     TestIfSmi(object);
     Check(ne, AbortReason::kOperandIsASmi, cr0);
@@ -2025,7 +2072,7 @@ void MacroAssembler::AssertNotSmi(Register object) {
 }
 
 void MacroAssembler::AssertSmi(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     TestIfSmi(object);
     Check(eq, AbortReason::kOperandIsNotASmi, cr0);
@@ -2033,7 +2080,7 @@ void MacroAssembler::AssertSmi(Register object) {
 }
 
 void MacroAssembler::AssertConstructor(Register object, Register scratch) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     TestIfSmi(object);
     Check(ne, AbortReason::kOperandIsASmiAndNotAConstructor);
@@ -2045,7 +2092,7 @@ void MacroAssembler::AssertConstructor(Register object, Register scratch) {
 }
 
 void MacroAssembler::AssertFunction(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     TestIfSmi(object);
     Check(ne, AbortReason::kOperandIsASmiAndNotAFunction, cr0);
@@ -2059,7 +2106,7 @@ void MacroAssembler::AssertFunction(Register object) {
 }
 
 void MacroAssembler::AssertBoundFunction(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     STATIC_ASSERT(kSmiTag == 0);
     TestIfSmi(object);
     Check(ne, AbortReason::kOperandIsASmiAndNotABoundFunction, cr0);
@@ -2071,7 +2118,7 @@ void MacroAssembler::AssertBoundFunction(Register object) {
 }
 
 void MacroAssembler::AssertGeneratorObject(Register object) {
-  if (!emit_debug_code()) return;
+  if (!FLAG_debug_code) return;
   TestIfSmi(object);
   Check(ne, AbortReason::kOperandIsASmiAndNotAGeneratorObject, cr0);
 
@@ -2101,7 +2148,7 @@ void MacroAssembler::AssertGeneratorObject(Register object) {
 
 void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
                                                      Register scratch) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label done_checking;
     AssertNotSmi(object);
     CompareRoot(object, RootIndex::kUndefinedValue);
diff --git a/chromium/v8/src/codegen/s390/macro-assembler-s390.h b/chromium/v8/src/codegen/s390/macro-assembler-s390.h
index f2719c3086c..13d7ac696b0 100644
--- a/chromium/v8/src/codegen/s390/macro-assembler-s390.h
+++ b/chromium/v8/src/codegen/s390/macro-assembler-s390.h
@@ -32,8 +32,6 @@ inline MemOperand FieldMemOperand(Register object, Register index, int offset) {
   return MemOperand(object, index, offset - kHeapObjectTag);
 }
 
-enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
-enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
 enum LinkRegisterStatus { kLRHasNotBeenSaved, kLRHasBeenSaved };
 
 Register GetRegisterThatIsNotOneOf(Register reg1, Register reg2 = no_reg,
@@ -70,6 +68,15 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
                 DoubleRegister right_reg);
   void FloatMin(DoubleRegister result_reg, DoubleRegister left_reg,
                 DoubleRegister right_reg);
+  void CeilF32(DoubleRegister dst, DoubleRegister src);
+  void CeilF64(DoubleRegister dst, DoubleRegister src);
+  void FloorF32(DoubleRegister dst, DoubleRegister src);
+  void FloorF64(DoubleRegister dst, DoubleRegister src);
+  void TruncF32(DoubleRegister dst, DoubleRegister src);
+  void TruncF64(DoubleRegister dst, DoubleRegister src);
+  void NearestIntF32(DoubleRegister dst, DoubleRegister src);
+  void NearestIntF64(DoubleRegister dst, DoubleRegister src);
+
   void LoadFromConstantsTable(Register destination,
                               int constant_index) override;
   void LoadRootRegisterOffset(Register destination, intptr_t offset) override;
@@ -769,9 +776,6 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void ResetRoundingMode();
 
   // These exist to provide portability between 32 and 64bit
-  void LoadP(Register dst, const MemOperand& mem, Register scratch = no_reg) {
-    LoadU64(dst, mem, scratch);
-  }
   void LoadMultipleP(Register dst1, Register dst2, const MemOperand& mem);
   void StoreMultipleP(Register dst1, Register dst2, const MemOperand& mem);
   void LoadMultipleW(Register dst1, Register dst2, const MemOperand& mem);
@@ -1094,22 +1098,22 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   }
 
   void CallRuntime(const Runtime::Function* f, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs);
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore);
   void CallRuntimeSaveDoubles(Runtime::FunctionId fid) {
     const Runtime::Function* function = Runtime::FunctionForId(fid);
-    CallRuntime(function, function->nargs, kSaveFPRegs);
+    CallRuntime(function, function->nargs, SaveFPRegsMode::kSave);
   }
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId fid,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     const Runtime::Function* function = Runtime::FunctionForId(fid);
     CallRuntime(function, function->nargs, save_doubles);
   }
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId fid, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     CallRuntime(Runtime::FunctionForId(fid), num_arguments, save_doubles);
   }
 
@@ -1220,7 +1224,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // Invoke the JavaScript function code by either calling or jumping.
   void InvokeFunctionCode(Register function, Register new_target,
                           Register expected_parameter_count,
-                          Register actual_parameter_count, InvokeFlag flag);
+                          Register actual_parameter_count, InvokeType type);
 
   // On function call, call into the debugger if necessary.
   void CheckDebugHook(Register fun, Register new_target,
@@ -1231,12 +1235,9 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // current context to the context in the function before invoking.
   void InvokeFunctionWithNewTarget(Register function, Register new_target,
                                    Register actual_parameter_count,
-                                   InvokeFlag flag);
+                                   InvokeType type);
   void InvokeFunction(Register function, Register expected_parameter_count,
-                      Register actual_parameter_count, InvokeFlag flag);
-
-  // Frame restart support
-  void MaybeDropFrames();
+                      Register actual_parameter_count, InvokeType type);
 
   // Exception handling
 
@@ -1353,8 +1354,8 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   void RecordWriteField(
       Register object, int offset, Register value, Register scratch,
       LinkRegisterStatus lr_status, SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
   // For a given |object| notify the garbage collector that the slot |address|
   // has been written.  |value| is the object being stored. The value and
@@ -1362,15 +1363,15 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   void RecordWrite(
       Register object, Register address, Register value,
       LinkRegisterStatus lr_status, SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
  private:
   static const int kSmiShift = kSmiTagSize + kSmiShiftSize;
   // Helper functions for generating invokes.
   void InvokePrologue(Register expected_parameter_count,
                       Register actual_parameter_count, Label* done,
-                      InvokeFlag flag);
+                      InvokeType type);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(MacroAssembler);
 };
diff --git a/chromium/v8/src/codegen/safepoint-table.cc b/chromium/v8/src/codegen/safepoint-table.cc
index 58fb6ed9e19..67a17d5f0ee 100644
--- a/chromium/v8/src/codegen/safepoint-table.cc
+++ b/chromium/v8/src/codegen/safepoint-table.cc
@@ -20,20 +20,18 @@ namespace internal {
 
 SafepointTable::SafepointTable(Isolate* isolate, Address pc, Code code)
     : SafepointTable(code.InstructionStart(isolate, pc),
-                     code.SafepointTableAddress(), code.stack_slots(), true) {}
+                     code.SafepointTableAddress(), true) {}
 
 #if V8_ENABLE_WEBASSEMBLY
 SafepointTable::SafepointTable(const wasm::WasmCode* code)
     : SafepointTable(code->instruction_start(),
                      code->instruction_start() + code->safepoint_table_offset(),
-                     code->stack_slots(), false) {}
+                     false) {}
 #endif  // V8_ENABLE_WEBASSEMBLY
 
 SafepointTable::SafepointTable(Address instruction_start,
-                               Address safepoint_table_address,
-                               uint32_t stack_slots, bool has_deopt)
+                               Address safepoint_table_address, bool has_deopt)
     : instruction_start_(instruction_start),
-      stack_slots_(stack_slots),
       has_deopt_(has_deopt),
       safepoint_table_address_(safepoint_table_address),
       length_(ReadLength(safepoint_table_address)),
@@ -69,27 +67,18 @@ SafepointEntry SafepointTable::FindEntry(Address pc) const {
   UNREACHABLE();
 }
 
-void SafepointTable::PrintEntry(unsigned index,
-                                std::ostream& os) const {  // NOLINT
+void SafepointTable::PrintEntry(unsigned index, std::ostream& os) const {
   disasm::NameConverter converter;
   SafepointEntry entry = GetEntry(index);
   uint8_t* bits = entry.bits();
 
   // Print the stack slot bits.
   if (entry_size_ > 0) {
-    const int first = 0;
-    int last = entry_size_ - 1;
-    for (int i = first; i < last; i++) PrintBits(os, bits[i], kBitsPerByte);
-    int last_bits = stack_slots_ - ((last - first) * kBitsPerByte);
-    PrintBits(os, bits[last], last_bits);
-  }
-}
-
-void SafepointTable::PrintBits(std::ostream& os,  // NOLINT
-                               uint8_t byte, int digits) {
-  DCHECK(digits >= 0 && digits <= kBitsPerByte);
-  for (int i = 0; i < digits; i++) {
-    os << (((byte & (1 << i)) == 0) ? "0" : "1");
+    for (uint32_t i = 0; i < entry_size_; ++i) {
+      for (int bit = 0; bit < kBitsPerByte; ++bit) {
+        os << ((bits[i] & (1 << bit)) ? "1" : "0");
+      }
+    }
   }
 }
 
@@ -122,6 +111,12 @@ int SafepointTableBuilder::UpdateDeoptimizationInfo(int pc, int trampoline,
 
 void SafepointTableBuilder::Emit(Assembler* assembler, int bits_per_entry) {
   RemoveDuplicates();
+  TrimEntries(&bits_per_entry);
+
+#if V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_ARM64
+  // We cannot emit a const pool within the safepoint table.
+  Assembler::BlockConstPoolScope block_const_pool(assembler);
+#endif
 
   // Make sure the safepoint table is properly aligned. Pad with nops.
   assembler->Align(Code::kMetadataAlignment);
@@ -168,6 +163,7 @@ void SafepointTableBuilder::Emit(Assembler* assembler, int bits_per_entry) {
 
     // Run through the indexes and build a bitmap.
     for (int idx : *indexes) {
+      DCHECK_GT(bits_per_entry, idx);
       int index = bits_per_entry - 1 - idx;
       int byte_index = index >> kBitsPerByteLog2;
       int bit_index = index & (kBitsPerByte - 1);
@@ -203,6 +199,28 @@ void SafepointTableBuilder::RemoveDuplicates() {
   deoptimization_info_.front().pc = kMaxUInt32;
 }
 
+void SafepointTableBuilder::TrimEntries(int* bits_per_entry) {
+  int min_index = *bits_per_entry;
+  if (min_index == 0) return;  // Early exit: nothing to trim.
+
+  for (auto& info : deoptimization_info_) {
+    for (int idx : *info.stack_indexes) {
+      DCHECK_GT(*bits_per_entry, idx);  // Validity check.
+      if (idx >= min_index) continue;
+      if (idx == 0) return;  // Early exit: nothing to trim.
+      min_index = idx;
+    }
+  }
+
+  DCHECK_LT(0, min_index);
+  *bits_per_entry -= min_index;
+  for (auto& info : deoptimization_info_) {
+    for (int& idx : *info.stack_indexes) {
+      idx -= min_index;
+    }
+  }
+}
+
 bool SafepointTableBuilder::IsIdenticalExceptForPc(
     const DeoptimizationInfo& info1, const DeoptimizationInfo& info2) const {
   if (info1.deopt_index != info2.deopt_index) return false;
diff --git a/chromium/v8/src/codegen/safepoint-table.h b/chromium/v8/src/codegen/safepoint-table.h
index 623b5246980..07bbcaf9a08 100644
--- a/chromium/v8/src/codegen/safepoint-table.h
+++ b/chromium/v8/src/codegen/safepoint-table.h
@@ -5,6 +5,7 @@
 #ifndef V8_CODEGEN_SAFEPOINT_TABLE_H_
 #define V8_CODEGEN_SAFEPOINT_TABLE_H_
 
+#include "src/base/iterator.h"
 #include "src/base/memory.h"
 #include "src/common/assert-scope.h"
 #include "src/utils/allocation.h"
@@ -21,11 +22,14 @@ class WasmCode;
 
 class SafepointEntry {
  public:
-  SafepointEntry()
-      : deopt_index_(0), bits_(nullptr), trampoline_pc_(kNoTrampolinePC) {}
-
-  SafepointEntry(unsigned deopt_index, uint8_t* bits, int trampoline_pc)
-      : deopt_index_(deopt_index), bits_(bits), trampoline_pc_(trampoline_pc) {
+  SafepointEntry() = default;
+
+  SafepointEntry(unsigned deopt_index, uint8_t* bits, uint8_t* bits_end,
+                 int trampoline_pc)
+      : deopt_index_(deopt_index),
+        bits_(bits),
+        bits_end_(bits_end),
+        trampoline_pc_(trampoline_pc) {
     DCHECK(is_valid());
   }
 
@@ -38,6 +42,7 @@ class SafepointEntry {
   void Reset() {
     deopt_index_ = 0;
     bits_ = nullptr;
+    bits_end_ = nullptr;
   }
 
   int trampoline_pc() { return trampoline_pc_; }
@@ -67,16 +72,23 @@ class SafepointEntry {
     return deopt_index_ != kNoDeoptIndex;
   }
 
-  uint8_t* bits() {
+  uint8_t* bits() const {
     DCHECK(is_valid());
     return bits_;
   }
 
+  base::iterator_range<uint8_t*> iterate_bits() const {
+    return base::make_iterator_range(bits_, bits_end_);
+  }
+
+  size_t entry_size() const { return bits_end_ - bits_; }
+
  private:
-  uint32_t deopt_index_;
-  uint8_t* bits_;
+  uint32_t deopt_index_ = 0;
+  uint8_t* bits_ = nullptr;
+  uint8_t* bits_end_ = nullptr;
   // It needs to be an integer as it is -1 for eager deoptimizations.
-  int trampoline_pc_;
+  int trampoline_pc_ = kNoTrampolinePC;
 };
 
 class SafepointTable {
@@ -117,17 +129,17 @@ class SafepointTable {
     int trampoline_pc = has_deopt_
                             ? base::Memory<int>(GetTrampolineLocation(index))
                             : SafepointEntry::kNoTrampolinePC;
-    return SafepointEntry(deopt_index, bits, trampoline_pc);
+    return SafepointEntry(deopt_index, bits, bits + entry_size_, trampoline_pc);
   }
 
   // Returns the entry for the given pc.
   SafepointEntry FindEntry(Address pc) const;
 
-  void PrintEntry(unsigned index, std::ostream& os) const;  // NOLINT
+  void PrintEntry(unsigned index, std::ostream& os) const;
 
  private:
   SafepointTable(Address instruction_start, Address safepoint_table_address,
-                 uint32_t stack_slots, bool has_deopt);
+                 bool has_deopt);
 
   static const uint8_t kNoRegisters = 0xFF;
 
@@ -165,12 +177,9 @@ class SafepointTable {
     return GetPcOffsetLocation(index) + kTrampolinePcOffset;
   }
 
-  static void PrintBits(std::ostream& os, uint8_t byte, int digits);
-
   DISALLOW_GARBAGE_COLLECTION(no_gc_)
 
   const Address instruction_start_;
-  const uint32_t stack_slots_;
   const bool has_deopt_;
 
   // Safepoint table layout.
@@ -254,6 +263,10 @@ class SafepointTableBuilder {
   // If all entries are identical, replace them by 1 entry with pc = kMaxUInt32.
   void RemoveDuplicates();
 
+  // Try to trim entries by removing trailing zeros (and shrinking
+  // {bits_per_entry}).
+  void TrimEntries(int* bits_per_entry);
+
   ZoneChunkList<DeoptimizationInfo> deoptimization_info_;
 
   unsigned offset_;
diff --git a/chromium/v8/src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.cc b/chromium/v8/src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.cc
index 366d1afac9e..3a73ae09f8a 100644
--- a/chromium/v8/src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.cc
+++ b/chromium/v8/src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.cc
@@ -29,6 +29,174 @@ void SharedTurboAssembler::Movapd(XMMRegister dst, XMMRegister src) {
   }
 }
 
+void SharedTurboAssembler::Shufps(XMMRegister dst, XMMRegister src1,
+                                  XMMRegister src2, uint8_t imm8) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope avx_scope(this, AVX);
+    vshufps(dst, src1, src2, imm8);
+  } else {
+    if (dst != src1) {
+      movaps(dst, src1);
+    }
+    shufps(dst, src2, imm8);
+  }
+}
+
+void SharedTurboAssembler::F64x2ExtractLane(DoubleRegister dst, XMMRegister src,
+                                            uint8_t lane) {
+  if (lane == 0) {
+    if (dst != src) {
+      Movaps(dst, src);
+    }
+  } else {
+    DCHECK_EQ(1, lane);
+    if (CpuFeatures::IsSupported(AVX)) {
+      CpuFeatureScope avx_scope(this, AVX);
+      // Pass src as operand to avoid false-dependency on dst.
+      vmovhlps(dst, src, src);
+    } else {
+      movhlps(dst, src);
+    }
+  }
+}
+
+void SharedTurboAssembler::F64x2ReplaceLane(XMMRegister dst, XMMRegister src,
+                                            DoubleRegister rep, uint8_t lane) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    if (lane == 0) {
+      vpblendw(dst, src, rep, 0b00001111);
+    } else {
+      vmovlhps(dst, src, rep);
+    }
+  } else {
+    CpuFeatureScope scope(this, SSE4_1);
+    if (dst != src) {
+      DCHECK_NE(dst, rep);  // Ensure rep is not overwritten.
+      movaps(dst, src);
+    }
+    if (lane == 0) {
+      pblendw(dst, rep, 0b00001111);
+    } else {
+      movlhps(dst, rep);
+    }
+  }
+}
+
+void SharedTurboAssembler::F64x2Min(XMMRegister dst, XMMRegister lhs,
+                                    XMMRegister rhs, XMMRegister scratch) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    // The minpd instruction doesn't propagate NaNs and +0's in its first
+    // operand. Perform minpd in both orders, merge the resuls, and adjust.
+    vminpd(scratch, lhs, rhs);
+    vminpd(dst, rhs, lhs);
+    // propagate -0's and NaNs, which may be non-canonical.
+    vorpd(scratch, scratch, dst);
+    // Canonicalize NaNs by quieting and clearing the payload.
+    vcmpunordpd(dst, dst, scratch);
+    vorpd(scratch, scratch, dst);
+    vpsrlq(dst, dst, byte{13});
+    vandnpd(dst, dst, scratch);
+  } else {
+    // Compare lhs with rhs, and rhs with lhs, and have the results in scratch
+    // and dst. If dst overlaps with lhs or rhs, we can save a move.
+    if (dst == lhs || dst == rhs) {
+      XMMRegister src = dst == lhs ? rhs : lhs;
+      movaps(scratch, src);
+      minpd(scratch, dst);
+      minpd(dst, src);
+    } else {
+      movaps(scratch, lhs);
+      movaps(dst, rhs);
+      minpd(scratch, rhs);
+      minpd(dst, lhs);
+    }
+    orpd(scratch, dst);
+    cmpunordpd(dst, scratch);
+    orpd(scratch, dst);
+    psrlq(dst, byte{13});
+    andnpd(dst, scratch);
+  }
+}
+
+void SharedTurboAssembler::F64x2Max(XMMRegister dst, XMMRegister lhs,
+                                    XMMRegister rhs, XMMRegister scratch) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    // The maxpd instruction doesn't propagate NaNs and +0's in its first
+    // operand. Perform maxpd in both orders, merge the resuls, and adjust.
+    vmaxpd(scratch, lhs, rhs);
+    vmaxpd(dst, rhs, lhs);
+    // Find discrepancies.
+    vxorpd(dst, dst, scratch);
+    // Propagate NaNs, which may be non-canonical.
+    vorpd(scratch, scratch, dst);
+    // Propagate sign discrepancy and (subtle) quiet NaNs.
+    vsubpd(scratch, scratch, dst);
+    // Canonicalize NaNs by clearing the payload. Sign is non-deterministic.
+    vcmpunordpd(dst, dst, scratch);
+    vpsrlq(dst, dst, byte{13});
+    vandnpd(dst, dst, scratch);
+  } else {
+    if (dst == lhs || dst == rhs) {
+      XMMRegister src = dst == lhs ? rhs : lhs;
+      movaps(scratch, src);
+      maxpd(scratch, dst);
+      maxpd(dst, src);
+    } else {
+      movaps(scratch, lhs);
+      movaps(dst, rhs);
+      maxpd(scratch, rhs);
+      maxpd(dst, lhs);
+    }
+    xorpd(dst, scratch);
+    orpd(scratch, dst);
+    subpd(scratch, dst);
+    cmpunordpd(dst, scratch);
+    psrlq(dst, byte{13});
+    andnpd(dst, scratch);
+  }
+}
+
+void SharedTurboAssembler::F32x4Splat(XMMRegister dst, DoubleRegister src) {
+  if (CpuFeatures::IsSupported(AVX2)) {
+    CpuFeatureScope avx2_scope(this, AVX2);
+    vbroadcastss(dst, src);
+  } else if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope avx_scope(this, AVX);
+    vshufps(dst, src, src, 0);
+  } else {
+    if (dst == src) {
+      // 1 byte shorter than pshufd.
+      shufps(dst, src, 0);
+    } else {
+      pshufd(dst, src, 0);
+    }
+  }
+}
+
+void SharedTurboAssembler::F32x4ExtractLane(FloatRegister dst, XMMRegister src,
+                                            uint8_t lane) {
+  DCHECK_LT(lane, 4);
+  // These instructions are shorter than insertps, but will leave junk in
+  // the top lanes of dst.
+  if (lane == 0) {
+    if (dst != src) {
+      Movaps(dst, src);
+    }
+  } else if (lane == 1) {
+    Movshdup(dst, src);
+  } else if (lane == 2 && dst == src) {
+    // Check dst == src to avoid false dependency on dst.
+    Movhlps(dst, src);
+  } else if (dst == src) {
+    Shufps(dst, src, src, lane);
+  } else {
+    Pshufd(dst, src, lane);
+  }
+}
+
 void SharedTurboAssembler::S128Store32Lane(Operand dst, XMMRegister src,
                                            uint8_t laneidx) {
   if (laneidx == 0) {
@@ -233,6 +401,22 @@ void SharedTurboAssembler::I32x4UConvertI16x8High(XMMRegister dst,
   }
 }
 
+void SharedTurboAssembler::I64x2Neg(XMMRegister dst, XMMRegister src,
+                                    XMMRegister scratch) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vpxor(scratch, scratch, scratch);
+    vpsubq(dst, scratch, src);
+  } else {
+    if (dst == src) {
+      movaps(scratch, src);
+      std::swap(src, scratch);
+    }
+    pxor(dst, dst);
+    psubq(dst, src);
+  }
+}
+
 void SharedTurboAssembler::I64x2Abs(XMMRegister dst, XMMRegister src,
                                     XMMRegister scratch) {
   if (CpuFeatures::IsSupported(AVX)) {
@@ -379,6 +563,17 @@ void SharedTurboAssembler::I64x2UConvertI32x4High(XMMRegister dst,
   }
 }
 
+void SharedTurboAssembler::S128Not(XMMRegister dst, XMMRegister src,
+                                   XMMRegister scratch) {
+  if (dst == src) {
+    Pcmpeqd(scratch, scratch);
+    Pxor(dst, scratch);
+  } else {
+    Pcmpeqd(dst, dst);
+    Pxor(dst, src);
+  }
+}
+
 void SharedTurboAssembler::S128Select(XMMRegister dst, XMMRegister mask,
                                       XMMRegister src1, XMMRegister src2,
                                       XMMRegister scratch) {
diff --git a/chromium/v8/src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.h b/chromium/v8/src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.h
index e2778e472d4..6be9444c658 100644
--- a/chromium/v8/src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.h
+++ b/chromium/v8/src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.h
@@ -39,121 +39,252 @@ class V8_EXPORT_PRIVATE SharedTurboAssembler : public TurboAssemblerBase {
     }
   }
 
-  template <typename Dst, typename... Args>
+  // Shufps that will mov src1 into dst if AVX is not supported.
+  void Shufps(XMMRegister dst, XMMRegister src1, XMMRegister src2,
+              uint8_t imm8);
+
+  // Helper struct to implement functions that check for AVX support and
+  // dispatch to the appropriate AVX/SSE instruction.
+  template <typename Dst, typename Arg, typename... Args>
   struct AvxHelper {
     Assembler* assm;
     base::Optional<CpuFeature> feature = base::nullopt;
     // Call a method where the AVX version expects the dst argument to be
     // duplicated.
-    template <void (Assembler::*avx)(Dst, Dst, Args...),
+    // E.g. Andps(x, y) -> vandps(x, x, y)
+    //                  -> andps(x, y)
+    template <void (Assembler::*avx)(Dst, Dst, Arg, Args...),
+              void (Assembler::*no_avx)(Dst, Arg, Args...)>
+    void emit(Dst dst, Arg arg, Args... args) {
+      if (CpuFeatures::IsSupported(AVX)) {
+        CpuFeatureScope scope(assm, AVX);
+        (assm->*avx)(dst, dst, arg, args...);
+      } else if (feature.has_value()) {
+        DCHECK(CpuFeatures::IsSupported(*feature));
+        CpuFeatureScope scope(assm, *feature);
+        (assm->*no_avx)(dst, arg, args...);
+      } else {
+        (assm->*no_avx)(dst, arg, args...);
+      }
+    }
+
+    // Call a method in the AVX form (one more operand), but if unsupported will
+    // check that dst == first src.
+    // E.g. Andps(x, y, z) -> vandps(x, y, z)
+    //                     -> andps(x, z) and check that x == y
+    template <void (Assembler::*avx)(Dst, Arg, Args...),
               void (Assembler::*no_avx)(Dst, Args...)>
-    void emit(Dst dst, Args... args) {
+    void emit(Dst dst, Arg arg, Args... args) {
       if (CpuFeatures::IsSupported(AVX)) {
         CpuFeatureScope scope(assm, AVX);
-        (assm->*avx)(dst, dst, args...);
+        (assm->*avx)(dst, arg, args...);
       } else if (feature.has_value()) {
+        DCHECK_EQ(dst, arg);
         DCHECK(CpuFeatures::IsSupported(*feature));
         CpuFeatureScope scope(assm, *feature);
         (assm->*no_avx)(dst, args...);
       } else {
+        DCHECK_EQ(dst, arg);
         (assm->*no_avx)(dst, args...);
       }
     }
 
     // Call a method where the AVX version expects no duplicated dst argument.
-    template <void (Assembler::*avx)(Dst, Args...),
-              void (Assembler::*no_avx)(Dst, Args...)>
-    void emit(Dst dst, Args... args) {
+    // E.g. Movddup(x, y) -> vmovddup(x, y)
+    //                    -> movddup(x, y)
+    template <void (Assembler::*avx)(Dst, Arg, Args...),
+              void (Assembler::*no_avx)(Dst, Arg, Args...)>
+    void emit(Dst dst, Arg arg, Args... args) {
       if (CpuFeatures::IsSupported(AVX)) {
         CpuFeatureScope scope(assm, AVX);
-        (assm->*avx)(dst, args...);
+        (assm->*avx)(dst, arg, args...);
       } else if (feature.has_value()) {
         DCHECK(CpuFeatures::IsSupported(*feature));
         CpuFeatureScope scope(assm, *feature);
-        (assm->*no_avx)(dst, args...);
+        (assm->*no_avx)(dst, arg, args...);
       } else {
-        (assm->*no_avx)(dst, args...);
+        (assm->*no_avx)(dst, arg, args...);
       }
     }
   };
 
-#define AVX_OP(macro_name, name)                                             \
-  template <typename Dst, typename... Args>                                  \
-  void macro_name(Dst dst, Args... args) {                                   \
-    AvxHelper<Dst, Args...>{this}                                            \
-        .template emit<&Assembler::v##name, &Assembler::name>(dst, args...); \
+#define AVX_OP(macro_name, name)                                        \
+  template <typename Dst, typename Arg, typename... Args>               \
+  void macro_name(Dst dst, Arg arg, Args... args) {                     \
+    AvxHelper<Dst, Arg, Args...>{this}                                  \
+        .template emit<&Assembler::v##name, &Assembler::name>(dst, arg, \
+                                                              args...); \
   }
 
-#define AVX_OP_SSE3(macro_name, name)                                        \
-  template <typename Dst, typename... Args>                                  \
-  void macro_name(Dst dst, Args... args) {                                   \
-    AvxHelper<Dst, Args...>{this, base::Optional<CpuFeature>(SSE3)}          \
-        .template emit<&Assembler::v##name, &Assembler::name>(dst, args...); \
+#define AVX_OP_SSE3(macro_name, name)                                    \
+  template <typename Dst, typename Arg, typename... Args>                \
+  void macro_name(Dst dst, Arg arg, Args... args) {                      \
+    AvxHelper<Dst, Arg, Args...>{this, base::Optional<CpuFeature>(SSE3)} \
+        .template emit<&Assembler::v##name, &Assembler::name>(dst, arg,  \
+                                                              args...);  \
   }
 
-#define AVX_OP_SSSE3(macro_name, name)                                       \
-  template <typename Dst, typename... Args>                                  \
-  void macro_name(Dst dst, Args... args) {                                   \
-    AvxHelper<Dst, Args...>{this, base::Optional<CpuFeature>(SSSE3)}         \
-        .template emit<&Assembler::v##name, &Assembler::name>(dst, args...); \
+#define AVX_OP_SSSE3(macro_name, name)                                    \
+  template <typename Dst, typename Arg, typename... Args>                 \
+  void macro_name(Dst dst, Arg arg, Args... args) {                       \
+    AvxHelper<Dst, Arg, Args...>{this, base::Optional<CpuFeature>(SSSE3)} \
+        .template emit<&Assembler::v##name, &Assembler::name>(dst, arg,   \
+                                                              args...);   \
   }
 
-#define AVX_OP_SSE4_1(macro_name, name)                                      \
-  template <typename Dst, typename... Args>                                  \
-  void macro_name(Dst dst, Args... args) {                                   \
-    AvxHelper<Dst, Args...>{this, base::Optional<CpuFeature>(SSE4_1)}        \
-        .template emit<&Assembler::v##name, &Assembler::name>(dst, args...); \
+#define AVX_OP_SSE4_1(macro_name, name)                                    \
+  template <typename Dst, typename Arg, typename... Args>                  \
+  void macro_name(Dst dst, Arg arg, Args... args) {                        \
+    AvxHelper<Dst, Arg, Args...>{this, base::Optional<CpuFeature>(SSE4_1)} \
+        .template emit<&Assembler::v##name, &Assembler::name>(dst, arg,    \
+                                                              args...);    \
   }
 
-#define AVX_OP_SSE4_2(macro_name, name)                                      \
-  template <typename Dst, typename... Args>                                  \
-  void macro_name(Dst dst, Args... args) {                                   \
-    AvxHelper<Dst, Args...>{this, base::Optional<CpuFeature>(SSE4_2)}        \
-        .template emit<&Assembler::v##name, &Assembler::name>(dst, args...); \
+#define AVX_OP_SSE4_2(macro_name, name)                                    \
+  template <typename Dst, typename Arg, typename... Args>                  \
+  void macro_name(Dst dst, Arg arg, Args... args) {                        \
+    AvxHelper<Dst, Arg, Args...>{this, base::Optional<CpuFeature>(SSE4_2)} \
+        .template emit<&Assembler::v##name, &Assembler::name>(dst, arg,    \
+                                                              args...);    \
   }
 
+  // Keep this list sorted by required extension, then instruction name.
+  AVX_OP(Addpd, addpd)
+  AVX_OP(Addps, addps)
+  AVX_OP(Andnpd, andnpd)
+  AVX_OP(Andnps, andnps)
+  AVX_OP(Andpd, andpd)
+  AVX_OP(Andps, andps)
+  AVX_OP(Cmpeqpd, cmpeqpd)
+  AVX_OP(Cmplepd, cmplepd)
+  AVX_OP(Cmpleps, cmpleps)
+  AVX_OP(Cmpltpd, cmpltpd)
+  AVX_OP(Cmpneqpd, cmpneqpd)
+  AVX_OP(Cmpunordpd, cmpunordpd)
+  AVX_OP(Cmpunordps, cmpunordps)
   AVX_OP(Cvtdq2pd, cvtdq2pd)
   AVX_OP(Cvtdq2ps, cvtdq2ps)
-  AVX_OP(Cvtps2pd, cvtps2pd)
   AVX_OP(Cvtpd2ps, cvtpd2ps)
+  AVX_OP(Cvtps2pd, cvtps2pd)
   AVX_OP(Cvttps2dq, cvttps2dq)
+  AVX_OP(Divpd, divpd)
+  AVX_OP(Divps, divps)
+  AVX_OP(Maxpd, maxpd)
+  AVX_OP(Maxps, maxps)
+  AVX_OP(Minpd, minpd)
+  AVX_OP(Minps, minps)
   AVX_OP(Movaps, movaps)
   AVX_OP(Movd, movd)
+  AVX_OP(Movhlps, movhlps)
   AVX_OP(Movhps, movhps)
   AVX_OP(Movlps, movlps)
   AVX_OP(Movmskpd, movmskpd)
   AVX_OP(Movmskps, movmskps)
-  AVX_OP(Movss, movss)
   AVX_OP(Movsd, movsd)
+  AVX_OP(Movss, movss)
   AVX_OP(Movupd, movupd)
   AVX_OP(Movups, movups)
+  AVX_OP(Mulpd, mulpd)
+  AVX_OP(Mulps, mulps)
+  AVX_OP(Orpd, orpd)
+  AVX_OP(Orps, orps)
+  AVX_OP(Packssdw, packssdw)
+  AVX_OP(Packsswb, packsswb)
+  AVX_OP(Packuswb, packuswb)
+  AVX_OP(Paddb, paddb)
+  AVX_OP(Paddd, paddd)
+  AVX_OP(Paddq, paddq)
+  AVX_OP(Paddsb, paddsb)
+  AVX_OP(Paddusb, paddusb)
+  AVX_OP(Paddusw, paddusw)
+  AVX_OP(Paddw, paddw)
+  AVX_OP(Pand, pand)
+  AVX_OP(Pavgb, pavgb)
+  AVX_OP(Pavgw, pavgw)
+  AVX_OP(Pcmpgtb, pcmpgtb)
+  AVX_OP(Pcmpeqd, pcmpeqd)
+  AVX_OP(Pmaxub, pmaxub)
+  AVX_OP(Pminub, pminub)
   AVX_OP(Pmovmskb, pmovmskb)
   AVX_OP(Pmullw, pmullw)
-  AVX_OP(Pshuflw, pshuflw)
-  AVX_OP(Pshufhw, pshufhw)
+  AVX_OP(Pmuludq, pmuludq)
+  AVX_OP(Por, por)
   AVX_OP(Pshufd, pshufd)
+  AVX_OP(Pshufhw, pshufhw)
+  AVX_OP(Pshuflw, pshuflw)
+  AVX_OP(Pslld, pslld)
+  AVX_OP(Psllq, psllq)
+  AVX_OP(Psllw, psllw)
+  AVX_OP(Psrad, psrad)
+  AVX_OP(Psraw, psraw)
+  AVX_OP(Psrld, psrld)
+  AVX_OP(Psrlq, psrlq)
+  AVX_OP(Psrlw, psrlw)
+  AVX_OP(Psubb, psubb)
+  AVX_OP(Psubd, psubd)
+  AVX_OP(Psubq, psubq)
+  AVX_OP(Psubsb, psubsb)
+  AVX_OP(Psubusb, psubusb)
+  AVX_OP(Psubw, psubw)
+  AVX_OP(Punpckhbw, punpckhbw)
+  AVX_OP(Punpckhdq, punpckhdq)
+  AVX_OP(Punpckhqdq, punpckhqdq)
+  AVX_OP(Punpckhwd, punpckhwd)
+  AVX_OP(Punpcklbw, punpcklbw)
+  AVX_OP(Punpckldq, punpckldq)
+  AVX_OP(Punpcklqdq, punpcklqdq)
+  AVX_OP(Punpcklwd, punpcklwd)
+  AVX_OP(Pxor, pxor)
   AVX_OP(Rcpps, rcpps)
   AVX_OP(Rsqrtps, rsqrtps)
-  AVX_OP(Sqrtps, sqrtps)
   AVX_OP(Sqrtpd, sqrtpd)
+  AVX_OP(Sqrtps, sqrtps)
+  AVX_OP(Sqrtsd, sqrtsd)
+  AVX_OP(Sqrtss, sqrtss)
+  AVX_OP(Subpd, subpd)
+  AVX_OP(Subps, subps)
+  AVX_OP(Unpcklps, unpcklps)
+  AVX_OP(Xorpd, xorpd)
+  AVX_OP(Xorps, xorps)
+
+  AVX_OP_SSE3(Haddps, haddps)
   AVX_OP_SSE3(Movddup, movddup)
   AVX_OP_SSE3(Movshdup, movshdup)
+
   AVX_OP_SSSE3(Pabsb, pabsb)
-  AVX_OP_SSSE3(Pabsw, pabsw)
   AVX_OP_SSSE3(Pabsd, pabsd)
+  AVX_OP_SSSE3(Pabsw, pabsw)
+  AVX_OP_SSSE3(Palignr, palignr)
+  AVX_OP_SSSE3(Psignb, psignb)
+  AVX_OP_SSSE3(Psignd, psignd)
+  AVX_OP_SSSE3(Psignw, psignw)
+
   AVX_OP_SSE4_1(Extractps, extractps)
+  AVX_OP_SSE4_1(Pblendw, pblendw)
   AVX_OP_SSE4_1(Pextrb, pextrb)
   AVX_OP_SSE4_1(Pextrw, pextrw)
+  AVX_OP_SSE4_1(Pmaxsb, pmaxsb)
+  AVX_OP_SSE4_1(Pmaxsd, pmaxsd)
+  AVX_OP_SSE4_1(Pminsb, pminsb)
   AVX_OP_SSE4_1(Pmovsxbw, pmovsxbw)
-  AVX_OP_SSE4_1(Pmovsxwd, pmovsxwd)
   AVX_OP_SSE4_1(Pmovsxdq, pmovsxdq)
+  AVX_OP_SSE4_1(Pmovsxwd, pmovsxwd)
   AVX_OP_SSE4_1(Pmovzxbw, pmovzxbw)
-  AVX_OP_SSE4_1(Pmovzxwd, pmovzxwd)
   AVX_OP_SSE4_1(Pmovzxdq, pmovzxdq)
+  AVX_OP_SSE4_1(Pmovzxwd, pmovzxwd)
   AVX_OP_SSE4_1(Ptest, ptest)
-  AVX_OP_SSE4_1(Roundps, roundps)
   AVX_OP_SSE4_1(Roundpd, roundpd)
+  AVX_OP_SSE4_1(Roundps, roundps)
 
+  void F64x2ExtractLane(DoubleRegister dst, XMMRegister src, uint8_t lane);
+  void F64x2ReplaceLane(XMMRegister dst, XMMRegister src, DoubleRegister rep,
+                        uint8_t lane);
+  void F64x2Min(XMMRegister dst, XMMRegister lhs, XMMRegister rhs,
+                XMMRegister scratch);
+  void F64x2Max(XMMRegister dst, XMMRegister lhs, XMMRegister rhs,
+                XMMRegister scratch);
+  void F32x4Splat(XMMRegister dst, DoubleRegister src);
+  void F32x4ExtractLane(FloatRegister dst, XMMRegister src, uint8_t lane);
   void S128Store32Lane(Operand dst, XMMRegister src, uint8_t laneidx);
   void I16x8ExtMulLow(XMMRegister dst, XMMRegister src1, XMMRegister src2,
                       XMMRegister scrat, bool is_signed);
@@ -170,6 +301,7 @@ class V8_EXPORT_PRIVATE SharedTurboAssembler : public TurboAssemblerBase {
   void I32x4SConvertI16x8High(XMMRegister dst, XMMRegister src);
   void I32x4UConvertI16x8High(XMMRegister dst, XMMRegister src,
                               XMMRegister scratch);
+  void I64x2Neg(XMMRegister dst, XMMRegister src, XMMRegister scratch);
   void I64x2Abs(XMMRegister dst, XMMRegister src, XMMRegister scratch);
   void I64x2GtS(XMMRegister dst, XMMRegister src0, XMMRegister src1,
                 XMMRegister scratch);
@@ -180,6 +312,7 @@ class V8_EXPORT_PRIVATE SharedTurboAssembler : public TurboAssemblerBase {
   void I64x2SConvertI32x4High(XMMRegister dst, XMMRegister src);
   void I64x2UConvertI32x4High(XMMRegister dst, XMMRegister src,
                               XMMRegister scratch);
+  void S128Not(XMMRegister dst, XMMRegister src, XMMRegister scratch);
   // Requires dst == mask when AVX is not supported.
   void S128Select(XMMRegister dst, XMMRegister mask, XMMRegister src1,
                   XMMRegister src2, XMMRegister scratch);
diff --git a/chromium/v8/src/codegen/signature.h b/chromium/v8/src/codegen/signature.h
index 2c4ca3e0d92..d6d8b5da0f6 100644
--- a/chromium/v8/src/codegen/signature.h
+++ b/chromium/v8/src/codegen/signature.h
@@ -104,6 +104,14 @@ class Signature : public ZoneObject {
     T* buffer_;
   };
 
+  static Signature<T>* Build(Zone* zone, std::initializer_list<T> returns,
+                             std::initializer_list<T> params) {
+    Builder builder(zone, returns.size(), params.size());
+    for (T ret : returns) builder.AddReturn(ret);
+    for (T param : params) builder.AddParam(param);
+    return builder.Build();
+  }
+
   static constexpr size_t kReturnCountOffset = 0;
   static constexpr size_t kParameterCountOffset =
       kReturnCountOffset + kSizetSize;
diff --git a/chromium/v8/src/codegen/source-position-table.cc b/chromium/v8/src/codegen/source-position-table.cc
index 63f1d17c70a..27466a26909 100644
--- a/chromium/v8/src/codegen/source-position-table.cc
+++ b/chromium/v8/src/codegen/source-position-table.cc
@@ -170,9 +170,9 @@ void SourcePositionTableBuilder::AddEntry(const PositionTableEntry& entry) {
 #endif
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<ByteArray> SourcePositionTableBuilder::ToSourcePositionTable(
-    LocalIsolate* isolate) {
+    IsolateT* isolate) {
   if (bytes_.empty()) return isolate->factory()->empty_byte_array();
   DCHECK(!Omit());
 
diff --git a/chromium/v8/src/codegen/source-position-table.h b/chromium/v8/src/codegen/source-position-table.h
index 72a4c9f45a8..afd7cc434c9 100644
--- a/chromium/v8/src/codegen/source-position-table.h
+++ b/chromium/v8/src/codegen/source-position-table.h
@@ -54,9 +54,9 @@ class V8_EXPORT_PRIVATE SourcePositionTableBuilder {
   void AddPosition(size_t code_offset, SourcePosition source_position,
                    bool is_statement);
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-  Handle<ByteArray> ToSourcePositionTable(LocalIsolate* isolate);
+  Handle<ByteArray> ToSourcePositionTable(IsolateT* isolate);
   OwnedVector<byte> ToSourcePositionTableVector();
 
   inline bool Omit() const { return mode_ != RECORD_SOURCE_POSITIONS; }
diff --git a/chromium/v8/src/codegen/string-constants.cc b/chromium/v8/src/codegen/string-constants.cc
index 92a5e973962..c1ad5a7b4b6 100644
--- a/chromium/v8/src/codegen/string-constants.cc
+++ b/chromium/v8/src/codegen/string-constants.cc
@@ -5,7 +5,6 @@
 #include "src/codegen/string-constants.h"
 
 #include "src/base/functional.h"
-#include "src/numbers/dtoa.h"
 #include "src/objects/objects.h"
 #include "src/objects/string-inl.h"
 
@@ -176,7 +175,7 @@ size_t StringConstantBase::GetMaxStringConstantLength() const {
 size_t StringLiteral::GetMaxStringConstantLength() const { return length_; }
 
 size_t NumberToStringConstant::GetMaxStringConstantLength() const {
-  return kBase10MaximalLength + 1;
+  return kMaxDoubleStringLength;
 }
 
 size_t StringCons::GetMaxStringConstantLength() const {
diff --git a/chromium/v8/src/codegen/turbo-assembler.cc b/chromium/v8/src/codegen/turbo-assembler.cc
index e4c694097be..a9f9e08ead6 100644
--- a/chromium/v8/src/codegen/turbo-assembler.cc
+++ b/chromium/v8/src/codegen/turbo-assembler.cc
@@ -115,12 +115,5 @@ bool TurboAssemblerBase::IsAddressableThroughRootRegister(
   return isolate->root_register_addressable_region().contains(address);
 }
 
-void TurboAssemblerBase::RecordCommentForOffHeapTrampoline(int builtin_index) {
-  if (!FLAG_code_comments) return;
-  std::ostringstream str;
-  str << "[ Inlined Trampoline to " << Builtins::name(builtin_index);
-  RecordComment(str.str().c_str());
-}
-
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/codegen/turbo-assembler.h b/chromium/v8/src/codegen/turbo-assembler.h
index cc9ef92919b..e25ee2a6295 100644
--- a/chromium/v8/src/codegen/turbo-assembler.h
+++ b/chromium/v8/src/codegen/turbo-assembler.h
@@ -118,13 +118,18 @@ class V8_EXPORT_PRIVATE TurboAssemblerBase : public Assembler {
   static bool IsAddressableThroughRootRegister(
       Isolate* isolate, const ExternalReference& reference);
 
-#ifdef V8_TARGET_OS_WIN
+#if defined(V8_TARGET_OS_WIN) || defined(V8_TARGET_OS_MACOSX)
   // Minimum page size. We must touch memory once per page when expanding the
   // stack, to avoid access violations.
   static constexpr int kStackPageSize = 4 * KB;
 #endif
 
-  void RecordCommentForOffHeapTrampoline(int builtin_index);
+  V8_INLINE void RecordCommentForOffHeapTrampoline(int builtin_index) {
+    if (!FLAG_code_comments) return;
+    std::ostringstream str;
+    str << "[ Inlined Trampoline to " << Builtins::name(builtin_index);
+    RecordComment(str.str().c_str());
+  }
 
  protected:
   Isolate* const isolate_ = nullptr;
@@ -150,8 +155,7 @@ class V8_EXPORT_PRIVATE TurboAssemblerBase : public Assembler {
 };
 
 // Avoids emitting calls to the {Builtins::kAbort} builtin when emitting debug
-// code during the lifetime of this scope object. For disabling debug code
-// entirely use the {DontEmitDebugCodeScope} instead.
+// code during the lifetime of this scope object.
 class V8_NODISCARD HardAbortScope {
  public:
   explicit HardAbortScope(TurboAssemblerBase* assembler)
@@ -165,27 +169,6 @@ class V8_NODISCARD HardAbortScope {
   bool old_value_;
 };
 
-#ifdef DEBUG
-struct CountIfValidRegisterFunctor {
-  template <typename RegType>
-  constexpr int operator()(int count, RegType reg) const {
-    return count + (reg.is_valid() ? 1 : 0);
-  }
-};
-
-template <typename RegType, typename... RegTypes,
-          // All arguments must be either Register or DoubleRegister.
-          typename = typename std::enable_if<
-              base::is_same<Register, RegType, RegTypes...>::value ||
-              base::is_same<DoubleRegister, RegType, RegTypes...>::value>::type>
-inline bool AreAliased(RegType first_reg, RegTypes... regs) {
-  int num_different_regs = NumRegs(RegType::ListOf(first_reg, regs...));
-  int num_given_regs =
-      base::fold(CountIfValidRegisterFunctor{}, 0, first_reg, regs...);
-  return num_different_regs < num_given_regs;
-}
-#endif
-
 }  // namespace internal
 }  // namespace v8
 
diff --git a/chromium/v8/src/codegen/x64/assembler-x64.cc b/chromium/v8/src/codegen/x64/assembler-x64.cc
index 032f7eb13d3..eb07f3ba3b7 100644
--- a/chromium/v8/src/codegen/x64/assembler-x64.cc
+++ b/chromium/v8/src/codegen/x64/assembler-x64.cc
@@ -86,45 +86,40 @@ void CpuFeatures::ProbeImpl(bool cross_compile) {
 
   // Only use statically determined features for cross compile (snapshot).
   if (cross_compile) return;
-
-  // To deal with any combination of flags (e.g. --no-enable-sse4-1
-  // --enable-sse-4-2), we start checking from the "highest" supported
-  // extension, for each extension, enable if newer extension is supported.
-  if (cpu.has_avx2() && FLAG_enable_avx2 && IsSupported(AVX)) {
-    supported_ |= 1u << AVX2;
-  }
-  if (cpu.has_fma3() && FLAG_enable_fma3 && cpu.has_osxsave() &&
-      OSHasAVXSupport()) {
-    supported_ |= 1u << FMA3;
-  }
-  if ((cpu.has_avx() && FLAG_enable_avx && cpu.has_osxsave() &&
-       OSHasAVXSupport()) ||
-      IsSupported(AVX2) || IsSupported(FMA3)) {
-    supported_ |= 1u << AVX;
-  }
-  if ((cpu.has_sse42() && FLAG_enable_sse4_2) || IsSupported(AVX)) {
-    supported_ |= 1u << SSE4_2;
-  }
-  if ((cpu.has_sse41() && FLAG_enable_sse4_1) || IsSupported(SSE4_2)) {
-    supported_ |= 1u << SSE4_1;
-  }
-  if ((cpu.has_ssse3() && FLAG_enable_ssse3) || IsSupported(SSE4_1)) {
-    supported_ |= 1u << SSSE3;
+  if (cpu.has_sse42()) SetSupported(SSE4_2);
+  if (cpu.has_sse41()) SetSupported(SSE4_1);
+  if (cpu.has_ssse3()) SetSupported(SSSE3);
+  if (cpu.has_sse3()) SetSupported(SSE3);
+  if (cpu.has_avx() && cpu.has_osxsave() && OSHasAVXSupport()) {
+    SetSupported(AVX);
+    if (cpu.has_avx2()) SetSupported(AVX2);
+    if (cpu.has_fma3()) SetSupported(FMA3);
   }
-  if ((cpu.has_sse3() && FLAG_enable_sse3) || IsSupported(SSSE3))
-    supported_ |= 1u << SSE3;
+
   // SAHF is not generally available in long mode.
-  if (cpu.has_sahf() && FLAG_enable_sahf) supported_ |= 1u << SAHF;
-  if (cpu.has_bmi1() && FLAG_enable_bmi1) supported_ |= 1u << BMI1;
-  if (cpu.has_bmi2() && FLAG_enable_bmi2) supported_ |= 1u << BMI2;
-  if (cpu.has_lzcnt() && FLAG_enable_lzcnt) supported_ |= 1u << LZCNT;
-  if (cpu.has_popcnt() && FLAG_enable_popcnt) supported_ |= 1u << POPCNT;
+  if (cpu.has_sahf() && FLAG_enable_sahf) SetSupported(SAHF);
+  if (cpu.has_bmi1() && FLAG_enable_bmi1) SetSupported(BMI1);
+  if (cpu.has_bmi2() && FLAG_enable_bmi2) SetSupported(BMI2);
+  if (cpu.has_lzcnt() && FLAG_enable_lzcnt) SetSupported(LZCNT);
+  if (cpu.has_popcnt() && FLAG_enable_popcnt) SetSupported(POPCNT);
   if (strcmp(FLAG_mcpu, "auto") == 0) {
-    if (cpu.is_atom()) supported_ |= 1u << ATOM;
+    if (cpu.is_atom()) SetSupported(ATOM);
   } else if (strcmp(FLAG_mcpu, "atom") == 0) {
-    supported_ |= 1u << ATOM;
+    SetSupported(ATOM);
   }
 
+  // Ensure that supported cpu features make sense. E.g. it is wrong to support
+  // AVX but not SSE4_2, if we have --enable-avx and --no-enable-sse4-2, the
+  // code above would set AVX to supported, and SSE4_2 to unsupported, then the
+  // checks below will set AVX to unsupported.
+  if (!FLAG_enable_sse3) SetUnsupported(SSE3);
+  if (!FLAG_enable_ssse3 || !IsSupported(SSE3)) SetUnsupported(SSSE3);
+  if (!FLAG_enable_sse4_1 || !IsSupported(SSSE3)) SetUnsupported(SSE4_1);
+  if (!FLAG_enable_sse4_2 || !IsSupported(SSE4_1)) SetUnsupported(SSE4_2);
+  if (!FLAG_enable_avx || !IsSupported(SSE4_2)) SetUnsupported(AVX);
+  if (!FLAG_enable_avx2 || !IsSupported(AVX)) SetUnsupported(AVX2);
+  if (!FLAG_enable_fma3 || !IsSupported(AVX)) SetUnsupported(FMA3);
+
   // Set a static value on whether Simd is supported.
   // This variable is only used for certain archs to query SupportWasmSimd128()
   // at runtime in builtins using an extern ref. Other callers should use
@@ -1419,12 +1414,13 @@ void Assembler::j(Condition cc, Label* L, Label::Distance distance) {
 }
 
 void Assembler::j(Condition cc, Address entry, RelocInfo::Mode rmode) {
-  DCHECK(RelocInfo::IsRuntimeEntry(rmode));
+  DCHECK(RelocInfo::IsWasmStubCall(rmode));
   EnsureSpace ensure_space(this);
   DCHECK(is_uint4(cc));
   emit(0x0F);
   emit(0x80 | cc);
-  emit_runtime_entry(entry, rmode);
+  RecordRelocInfo(rmode);
+  emitl(static_cast<int32_t>(entry));
 }
 
 void Assembler::j(Condition cc, Handle<Code> target, RelocInfo::Mode rmode) {
diff --git a/chromium/v8/src/codegen/x64/assembler-x64.h b/chromium/v8/src/codegen/x64/assembler-x64.h
index 97e18ed8fef..e6205311c2d 100644
--- a/chromium/v8/src/codegen/x64/assembler-x64.h
+++ b/chromium/v8/src/codegen/x64/assembler-x64.h
@@ -124,6 +124,9 @@ class Immediate {
     DCHECK(SmiValuesAre31Bits());  // Only available for 31-bit SMI.
   }
 
+  int32_t value() const { return value_; }
+  RelocInfo::Mode rmode() const { return rmode_; }
+
  private:
   const int32_t value_;
   const RelocInfo::Mode rmode_ = RelocInfo::NONE;
@@ -1274,6 +1277,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   SSE_CMP_P(cmpeq, 0x0)
   SSE_CMP_P(cmplt, 0x1)
   SSE_CMP_P(cmple, 0x2)
+  SSE_CMP_P(cmpunord, 0x3)
   SSE_CMP_P(cmpneq, 0x4)
   SSE_CMP_P(cmpnlt, 0x5)
   SSE_CMP_P(cmpnle, 0x6)
@@ -1571,6 +1575,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   AVX_CMP_P(vcmpeq, 0x0)
   AVX_CMP_P(vcmplt, 0x1)
   AVX_CMP_P(vcmple, 0x2)
+  AVX_CMP_P(vcmpunord, 0x3)
   AVX_CMP_P(vcmpneq, 0x4)
   AVX_CMP_P(vcmpnlt, 0x5)
   AVX_CMP_P(vcmpnle, 0x6)
@@ -2374,8 +2379,8 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
 // checks that we did not generate too much.
 class EnsureSpace {
  public:
-  explicit EnsureSpace(Assembler* assembler) : assembler_(assembler) {
-    if (assembler_->buffer_overflow()) assembler_->GrowBuffer();
+  explicit V8_INLINE EnsureSpace(Assembler* assembler) : assembler_(assembler) {
+    if (V8_UNLIKELY(assembler_->buffer_overflow())) assembler_->GrowBuffer();
 #ifdef DEBUG
     space_before_ = assembler_->available_space();
 #endif
@@ -2389,7 +2394,7 @@ class EnsureSpace {
 #endif
 
  private:
-  Assembler* assembler_;
+  Assembler* const assembler_;
 #ifdef DEBUG
   int space_before_;
 #endif
diff --git a/chromium/v8/src/codegen/x64/interface-descriptors-x64-inl.h b/chromium/v8/src/codegen/x64/interface-descriptors-x64-inl.h
new file mode 100644
index 00000000000..a24330a4c77
--- /dev/null
+++ b/chromium/v8/src/codegen/x64/interface-descriptors-x64-inl.h
@@ -0,0 +1,258 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_CODEGEN_X64_INTERFACE_DESCRIPTORS_X64_INL_H_
+#define V8_CODEGEN_X64_INTERFACE_DESCRIPTORS_X64_INL_H_
+
+#if V8_TARGET_ARCH_X64
+
+#include "src/codegen/interface-descriptors.h"
+
+namespace v8 {
+namespace internal {
+
+constexpr auto CallInterfaceDescriptor::DefaultRegisterArray() {
+  auto registers = RegisterArray(rax, rbx, rcx, rdx, rdi);
+  STATIC_ASSERT(registers.size() == kMaxBuiltinRegisterParams);
+  return registers;
+}
+
+// static
+constexpr auto RecordWriteDescriptor::registers() {
+  return RegisterArray(arg_reg_1, arg_reg_2, arg_reg_3, arg_reg_4,
+                       kReturnRegister0);
+}
+
+// static
+constexpr auto DynamicCheckMapsDescriptor::registers() {
+  return RegisterArray(kReturnRegister0, arg_reg_1, arg_reg_2, arg_reg_3,
+                       kRuntimeCallFunctionRegister, kContextRegister);
+}
+
+// static
+constexpr auto EphemeronKeyBarrierDescriptor::registers() {
+  return RegisterArray(arg_reg_1, arg_reg_2, arg_reg_3, arg_reg_4,
+                       kReturnRegister0);
+}
+
+// static
+constexpr Register LoadDescriptor::ReceiverRegister() { return rdx; }
+// static
+constexpr Register LoadDescriptor::NameRegister() { return rcx; }
+// static
+constexpr Register LoadDescriptor::SlotRegister() { return rax; }
+
+// static
+constexpr Register LoadWithVectorDescriptor::VectorRegister() { return rbx; }
+
+// static
+constexpr Register
+LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
+  return rdi;
+}
+
+// static
+constexpr Register StoreDescriptor::ReceiverRegister() { return rdx; }
+// static
+constexpr Register StoreDescriptor::NameRegister() { return rcx; }
+// static
+constexpr Register StoreDescriptor::ValueRegister() { return rax; }
+// static
+constexpr Register StoreDescriptor::SlotRegister() { return rdi; }
+
+// static
+constexpr Register StoreWithVectorDescriptor::VectorRegister() { return rbx; }
+
+// static
+constexpr Register StoreTransitionDescriptor::MapRegister() { return r11; }
+
+// static
+constexpr Register ApiGetterDescriptor::HolderRegister() { return rcx; }
+// static
+constexpr Register ApiGetterDescriptor::CallbackRegister() { return rbx; }
+
+// static
+constexpr Register GrowArrayElementsDescriptor::ObjectRegister() { return rax; }
+// static
+constexpr Register GrowArrayElementsDescriptor::KeyRegister() { return rbx; }
+
+// static
+constexpr Register BaselineLeaveFrameDescriptor::ParamsSizeRegister() {
+  return rbx;
+}
+// static
+constexpr Register BaselineLeaveFrameDescriptor::WeightRegister() {
+  return rcx;
+}
+
+// static
+constexpr Register TypeConversionDescriptor::ArgumentRegister() { return rax; }
+
+// static
+constexpr auto TypeofDescriptor::registers() { return RegisterArray(rbx); }
+
+// static
+constexpr auto CallTrampolineDescriptor::registers() {
+  // rax : number of arguments
+  // rdi : the target to call
+  return RegisterArray(rdi, rax);
+}
+
+// static
+constexpr auto CallVarargsDescriptor::registers() {
+  // rax : number of arguments (on the stack, not including receiver)
+  // rdi : the target to call
+  // rcx : arguments list length (untagged)
+  // rbx : arguments list (FixedArray)
+  return RegisterArray(rdi, rax, rcx, rbx);
+}
+
+// static
+constexpr auto CallForwardVarargsDescriptor::registers() {
+  // rax : number of arguments
+  // rcx : start index (to support rest parameters)
+  // rdi : the target to call
+  return RegisterArray(rdi, rax, rcx);
+}
+
+// static
+constexpr auto CallFunctionTemplateDescriptor::registers() {
+  // rdx: the function template info
+  // rcx: number of arguments (on the stack, not including receiver)
+  return RegisterArray(rdx, rcx);
+}
+
+// static
+constexpr auto CallWithSpreadDescriptor::registers() {
+  // rax : number of arguments (on the stack, not including receiver)
+  // rdi : the target to call
+  // rbx : the object to spread
+  return RegisterArray(rdi, rax, rbx);
+}
+
+// static
+constexpr auto CallWithArrayLikeDescriptor::registers() {
+  // rdi : the target to call
+  // rbx : the arguments list
+  return RegisterArray(rdi, rbx);
+}
+
+// static
+constexpr auto ConstructVarargsDescriptor::registers() {
+  // rax : number of arguments (on the stack, not including receiver)
+  // rdi : the target to call
+  // rdx : the new target
+  // rcx : arguments list length (untagged)
+  // rbx : arguments list (FixedArray)
+  return RegisterArray(rdi, rdx, rax, rcx, rbx);
+}
+
+// static
+constexpr auto ConstructForwardVarargsDescriptor::registers() {
+  // rax : number of arguments
+  // rdx : the new target
+  // rcx : start index (to support rest parameters)
+  // rdi : the target to call
+  return RegisterArray(rdi, rdx, rax, rcx);
+}
+
+// static
+constexpr auto ConstructWithSpreadDescriptor::registers() {
+  // rax : number of arguments (on the stack, not including receiver)
+  // rdi : the target to call
+  // rdx : the new target
+  // rbx : the object to spread
+  return RegisterArray(rdi, rdx, rax, rbx);
+}
+
+// static
+constexpr auto ConstructWithArrayLikeDescriptor::registers() {
+  // rdi : the target to call
+  // rdx : the new target
+  // rbx : the arguments list
+  return RegisterArray(rdi, rdx, rbx);
+}
+
+// static
+constexpr auto ConstructStubDescriptor::registers() {
+  // rax : number of arguments
+  // rdx : the new target
+  // rdi : the target to call
+  // rbx : allocation site or undefined
+  return RegisterArray(rdi, rdx, rax, rbx);
+}
+
+// static
+constexpr auto AbortDescriptor::registers() { return RegisterArray(rdx); }
+
+// static
+constexpr auto CompareDescriptor::registers() {
+  return RegisterArray(rdx, rax);
+}
+
+// static
+constexpr auto BinaryOpDescriptor::registers() {
+  return RegisterArray(rdx, rax);
+}
+
+// static
+constexpr auto Compare_BaselineDescriptor::registers() {
+  return RegisterArray(rdx, rax, rbx);
+}
+
+// static
+constexpr auto BinaryOp_BaselineDescriptor::registers() {
+  return RegisterArray(rdx, rax, rbx);
+}
+
+// static
+constexpr auto ApiCallbackDescriptor::registers() {
+  return RegisterArray(rdx,   // api function address
+                       rcx,   // argument count (not including receiver)
+                       rbx,   // call data
+                       rdi);  // holder
+}
+
+// static
+constexpr auto InterpreterDispatchDescriptor::registers() {
+  return RegisterArray(
+      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
+      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister);
+}
+
+// static
+constexpr auto InterpreterPushArgsThenCallDescriptor::registers() {
+  return RegisterArray(rax,   // argument count (not including receiver)
+                       rbx,   // address of first argument
+                       rdi);  // the target callable to be call
+}
+
+// static
+constexpr auto InterpreterPushArgsThenConstructDescriptor::registers() {
+  return RegisterArray(
+      rax,   // argument count (not including receiver)
+      rcx,   // address of first argument
+      rdi,   // constructor to call
+      rdx,   // new target
+      rbx);  // allocation site feedback if available, undefined otherwise
+}
+
+// static
+constexpr auto ResumeGeneratorDescriptor::registers() {
+  return RegisterArray(
+      rax,   // the value to pass to the generator
+      rdx);  // the JSGeneratorObject / JSAsyncGeneratorObject to resume
+}
+
+// static
+constexpr auto RunMicrotasksEntryDescriptor::registers() {
+  return RegisterArray(arg_reg_1, arg_reg_2);
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TARGET_ARCH_X64
+
+#endif  // V8_CODEGEN_X64_INTERFACE_DESCRIPTORS_X64_INL_H_
diff --git a/chromium/v8/src/codegen/x64/interface-descriptors-x64.cc b/chromium/v8/src/codegen/x64/interface-descriptors-x64.cc
deleted file mode 100644
index 4029b56d2b3..00000000000
--- a/chromium/v8/src/codegen/x64/interface-descriptors-x64.cc
+++ /dev/null
@@ -1,309 +0,0 @@
-// Copyright 2012 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#if V8_TARGET_ARCH_X64
-
-#include "src/codegen/interface-descriptors.h"
-
-#include "src/execution/frames.h"
-
-namespace v8 {
-namespace internal {
-
-const Register CallInterfaceDescriptor::ContextRegister() { return rsi; }
-
-void CallInterfaceDescriptor::DefaultInitializePlatformSpecific(
-    CallInterfaceDescriptorData* data, int register_parameter_count) {
-  const Register default_stub_registers[] = {rax, rbx, rcx, rdx, rdi};
-  CHECK_LE(static_cast<size_t>(register_parameter_count),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(register_parameter_count,
-                                   default_stub_registers);
-}
-
-void RecordWriteDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {arg_reg_1, arg_reg_2, arg_reg_3,
-                                             arg_reg_4, kReturnRegister0};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void DynamicCheckMapsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register default_stub_registers[] = {kReturnRegister0,
-                                       arg_reg_1,
-                                       arg_reg_2,
-                                       arg_reg_3,
-                                       kRuntimeCallFunctionRegister,
-                                       kContextRegister};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-void EphemeronKeyBarrierDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  const Register default_stub_registers[] = {arg_reg_1, arg_reg_2, arg_reg_3,
-                                             arg_reg_4, kReturnRegister0};
-
-  data->RestrictAllocatableRegisters(default_stub_registers,
-                                     arraysize(default_stub_registers));
-
-  CHECK_LE(static_cast<size_t>(kParameterCount),
-           arraysize(default_stub_registers));
-  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
-}
-
-const Register LoadDescriptor::ReceiverRegister() { return rdx; }
-const Register LoadDescriptor::NameRegister() { return rcx; }
-const Register LoadDescriptor::SlotRegister() { return rax; }
-
-const Register LoadWithVectorDescriptor::VectorRegister() { return rbx; }
-
-const Register
-LoadWithReceiverAndVectorDescriptor::LookupStartObjectRegister() {
-  return rdi;
-}
-
-const Register StoreDescriptor::ReceiverRegister() { return rdx; }
-const Register StoreDescriptor::NameRegister() { return rcx; }
-const Register StoreDescriptor::ValueRegister() { return rax; }
-const Register StoreDescriptor::SlotRegister() { return rdi; }
-
-const Register StoreWithVectorDescriptor::VectorRegister() { return rbx; }
-
-const Register StoreTransitionDescriptor::SlotRegister() { return rdi; }
-const Register StoreTransitionDescriptor::VectorRegister() { return rbx; }
-const Register StoreTransitionDescriptor::MapRegister() { return r11; }
-
-const Register ApiGetterDescriptor::HolderRegister() { return rcx; }
-const Register ApiGetterDescriptor::CallbackRegister() { return rbx; }
-
-const Register GrowArrayElementsDescriptor::ObjectRegister() { return rax; }
-const Register GrowArrayElementsDescriptor::KeyRegister() { return rbx; }
-
-const Register BaselineLeaveFrameDescriptor::ParamsSizeRegister() {
-  return rbx;
-}
-const Register BaselineLeaveFrameDescriptor::WeightRegister() { return rcx; }
-
-void TypeofDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {rbx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-// static
-const Register TypeConversionDescriptor::ArgumentRegister() { return rax; }
-
-void CallTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // rax : number of arguments
-  // rdi : the target to call
-  Register registers[] = {rdi, rax};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // rax : number of arguments (on the stack, not including receiver)
-  // rdi : the target to call
-  // rcx : arguments list length (untagged)
-  // rbx : arguments list (FixedArray)
-  Register registers[] = {rdi, rax, rcx, rbx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // rax : number of arguments
-  // rcx : start index (to support rest parameters)
-  // rdi : the target to call
-  Register registers[] = {rdi, rax, rcx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallFunctionTemplateDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // rdx: the function template info
-  // rcx: number of arguments (on the stack, not including receiver)
-  Register registers[] = {rdx, rcx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // rax : number of arguments (on the stack, not including receiver)
-  // rdi : the target to call
-  // rbx : the object to spread
-  Register registers[] = {rdi, rax, rbx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CallWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // rdi : the target to call
-  // rbx : the arguments list
-  Register registers[] = {rdi, rbx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // rax : number of arguments (on the stack, not including receiver)
-  // rdi : the target to call
-  // rdx : the new target
-  // rcx : arguments list length (untagged)
-  // rbx : arguments list (FixedArray)
-  Register registers[] = {rdi, rdx, rax, rcx, rbx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructForwardVarargsDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // rax : number of arguments
-  // rdx : the new target
-  // rcx : start index (to support rest parameters)
-  // rdi : the target to call
-  Register registers[] = {rdi, rdx, rax, rcx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithSpreadDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // rax : number of arguments (on the stack, not including receiver)
-  // rdi : the target to call
-  // rdx : the new target
-  // rbx : the object to spread
-  Register registers[] = {rdi, rdx, rax, rbx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructWithArrayLikeDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // rdi : the target to call
-  // rdx : the new target
-  // rbx : the arguments list
-  Register registers[] = {rdi, rdx, rbx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ConstructStubDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  // rax : number of arguments
-  // rdx : the new target
-  // rdi : the target to call
-  // rbx : allocation site or undefined
-  Register registers[] = {rdi, rdx, rax, rbx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void AbortDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {rdx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void CompareDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {rdx, rax};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void Compare_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {rdx, rax, rbx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void BinaryOpDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {rdx, rax};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void BinaryOp_BaselineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {rdx, rax, rbx};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ApiCallbackDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      rdx,  // api function address
-      rcx,  // argument count (not including receiver)
-      rbx,  // call data
-      rdi,  // holder
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterDispatchDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      kInterpreterAccumulatorRegister, kInterpreterBytecodeOffsetRegister,
-      kInterpreterBytecodeArrayRegister, kInterpreterDispatchTableRegister};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenCallDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      rax,  // argument count (not including receiver)
-      rbx,  // address of first argument
-      rdi   // the target callable to be call
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void InterpreterPushArgsThenConstructDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      rax,  // argument count (not including receiver)
-      rcx,  // address of first argument
-      rdi,  // constructor to call
-      rdx,  // new target
-      rbx,  // allocation site feedback if available, undefined otherwise
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void ResumeGeneratorDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      rax,  // the value to pass to the generator
-      rdx   // the JSGeneratorObject / JSAsyncGeneratorObject to resume
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void FrameDropperTrampolineDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {
-      rbx,  // loaded new FP
-  };
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void RunMicrotasksEntryDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {arg_reg_1, arg_reg_2};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_TARGET_ARCH_X64
diff --git a/chromium/v8/src/codegen/x64/macro-assembler-x64.cc b/chromium/v8/src/codegen/x64/macro-assembler-x64.cc
index cb254370b25..53f3f97f9ae 100644
--- a/chromium/v8/src/codegen/x64/macro-assembler-x64.cc
+++ b/chromium/v8/src/codegen/x64/macro-assembler-x64.cc
@@ -12,6 +12,7 @@
 #include "src/codegen/code-factory.h"
 #include "src/codegen/cpu-features.h"
 #include "src/codegen/external-reference-table.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/macro-assembler.h"
 #include "src/codegen/register-configuration.h"
 #include "src/codegen/string-constants.h"
@@ -194,6 +195,9 @@ void TurboAssembler::CompareRoot(Operand with, RootIndex index) {
 void TurboAssembler::LoadMap(Register destination, Register object) {
   LoadTaggedPointerField(destination,
                          FieldOperand(object, HeapObject::kMapOffset));
+#ifdef V8_MAP_PACKING
+  UnpackMapWord(destination);
+#endif
 }
 
 void TurboAssembler::LoadTaggedPointerField(Register destination,
@@ -205,6 +209,16 @@ void TurboAssembler::LoadTaggedPointerField(Register destination,
   }
 }
 
+#ifdef V8_MAP_PACKING
+void TurboAssembler::UnpackMapWord(Register r) {
+  // Clear the top two bytes (which may include metadata). Must be in sync with
+  // MapWord::Unpack, and vice versa.
+  shlq(r, Immediate(16));
+  shrq(r, Immediate(16));
+  xorq(r, Immediate(Internals::kMapWordXorMask));
+}
+#endif
+
 void TurboAssembler::LoadTaggedSignedField(Register destination,
                                            Operand field_operand) {
   if (COMPRESS_POINTERS_BOOL) {
@@ -288,7 +302,7 @@ void TurboAssembler::DecompressTaggedPointer(Register destination,
                                              Operand field_operand) {
   RecordComment("[ DecompressTaggedPointer");
   movl(destination, field_operand);
-  addq(destination, kPointerCageBaseRegister);
+  addq(destination, kPtrComprCageBaseRegister);
   RecordComment("]");
 }
 
@@ -296,7 +310,7 @@ void TurboAssembler::DecompressTaggedPointer(Register destination,
                                              Register source) {
   RecordComment("[ DecompressTaggedPointer");
   movl(destination, source);
-  addq(destination, kPointerCageBaseRegister);
+  addq(destination, kPtrComprCageBaseRegister);
   RecordComment("]");
 }
 
@@ -304,7 +318,7 @@ void TurboAssembler::DecompressAnyTagged(Register destination,
                                          Operand field_operand) {
   RecordComment("[ DecompressAnyTagged");
   movl(destination, field_operand);
-  addq(destination, kPointerCageBaseRegister);
+  addq(destination, kPtrComprCageBaseRegister);
   RecordComment("]");
 }
 
@@ -318,7 +332,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   Label done;
 
   // Skip barrier if writing a smi.
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     JumpIfSmi(value, &done);
   }
 
@@ -327,7 +341,7 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   DCHECK(IsAligned(offset, kTaggedSize));
 
   leaq(dst, FieldOperand(object, offset));
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label ok;
     testb(dst, Immediate(kTaggedSize - 1));
     j(zero, &ok, Label::kNear);
@@ -336,13 +350,13 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
   }
 
   RecordWrite(object, dst, value, save_fp, remembered_set_action,
-              OMIT_SMI_CHECK);
+              SmiCheck::kOmit);
 
   bind(&done);
 
   // Clobber clobbered input registers when running with the debug-code flag
   // turned on to provoke errors.
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Move(value, kZapValue, RelocInfo::NONE);
     Move(dst, kZapValue, RelocInfo::NONE);
   }
@@ -357,19 +371,27 @@ void TurboAssembler::SaveRegisters(RegList registers) {
   }
 }
 
-void TurboAssembler::LoadExternalPointerField(Register destination,
-                                              Operand field_operand,
-                                              ExternalPointerTag tag) {
+void TurboAssembler::LoadExternalPointerField(
+    Register destination, Operand field_operand, ExternalPointerTag tag,
+    Register scratch, IsolateRootLocation isolateRootLocation) {
 #ifdef V8_HEAP_SANDBOX
-  LoadAddress(kScratchRegister,
-              ExternalReference::external_pointer_table_address(isolate()));
-  movq(kScratchRegister,
-       Operand(kScratchRegister, Internals::kExternalPointerTableBufferOffset));
+  DCHECK(!field_operand.AddressUsesRegister(scratch));
+  if (isolateRootLocation == IsolateRootLocation::kInRootRegister) {
+    DCHECK(root_array_available_);
+    movq(scratch, Operand(kRootRegister,
+                          IsolateData::external_pointer_table_offset() +
+                              Internals::kExternalPointerTableBufferOffset));
+  } else {
+    DCHECK(isolateRootLocation == IsolateRootLocation::kInScratchRegister);
+    movq(scratch,
+         Operand(scratch, IsolateData::external_pointer_table_offset() +
+                              Internals::kExternalPointerTableBufferOffset));
+  }
   movl(destination, field_operand);
-  movq(destination, Operand(kScratchRegister, destination, times_8, 0));
+  movq(destination, Operand(scratch, destination, times_8, 0));
   if (tag != 0) {
-    movq(kScratchRegister, Immediate64(tag));
-    xorq(destination, kScratchRegister);
+    movq(scratch, Immediate64(~tag));
+    andq(destination, scratch);
   }
 #else
   movq(destination, field_operand);
@@ -480,13 +502,13 @@ void MacroAssembler::RecordWrite(Register object, Register address,
   DCHECK(value != address);
   AssertNotSmi(object);
 
-  if ((remembered_set_action == OMIT_REMEMBERED_SET &&
+  if ((remembered_set_action == RememberedSetAction::kOmit &&
        !FLAG_incremental_marking) ||
       FLAG_disable_write_barriers) {
     return;
   }
 
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label ok;
     cmp_tagged(value, Operand(address, 0));
     j(equal, &ok, Label::kNear);
@@ -498,7 +520,7 @@ void MacroAssembler::RecordWrite(Register object, Register address,
   // catch stores of smis and stores into the young generation.
   Label done;
 
-  if (smi_check == INLINE_SMI_CHECK) {
+  if (smi_check == SmiCheck::kInline) {
     // Skip barrier if writing a smi.
     JumpIfSmi(value, &done);
   }
@@ -519,18 +541,18 @@ void MacroAssembler::RecordWrite(Register object, Register address,
 
   // Clobber clobbered registers when running with the debug-code flag
   // turned on to provoke errors.
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Move(address, kZapValue, RelocInfo::NONE);
     Move(value, kZapValue, RelocInfo::NONE);
   }
 }
 
 void TurboAssembler::Assert(Condition cc, AbortReason reason) {
-  if (emit_debug_code()) Check(cc, reason);
+  if (FLAG_debug_code) Check(cc, reason);
 }
 
 void TurboAssembler::AssertUnreachable(AbortReason reason) {
-  if (emit_debug_code()) Abort(reason);
+  if (FLAG_debug_code) Abort(reason);
 }
 
 void TurboAssembler::Check(Condition cc, AbortReason reason) {
@@ -556,11 +578,11 @@ void TurboAssembler::CheckStackAlignment() {
 }
 
 void TurboAssembler::Abort(AbortReason reason) {
-#ifdef DEBUG
-  const char* msg = GetAbortReason(reason);
-  RecordComment("Abort message: ");
-  RecordComment(msg);
-#endif
+  if (FLAG_code_comments) {
+    const char* msg = GetAbortReason(reason);
+    RecordComment("Abort message: ");
+    RecordComment(msg);
+  }
 
   // Avoid emitting call to builtin if requested.
   if (trap_on_abort()) {
@@ -603,7 +625,7 @@ void MacroAssembler::CallRuntime(const Runtime::Function* f, int num_arguments,
   // arguments passed in because it is constant. At some point we
   // should remove this need and make the runtime routine entry code
   // smarter.
-  Set(rax, num_arguments);
+  Move(rax, num_arguments);
   LoadAddress(rbx, ExternalReference::Create(f));
   Handle<Code> code =
       CodeFactory::CEntry(isolate(), f->result_size, save_doubles);
@@ -624,7 +646,7 @@ void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid) {
   const Runtime::Function* function = Runtime::FunctionForId(fid);
   DCHECK_EQ(1, function->result_size);
   if (function->nargs >= 0) {
-    Set(rax, function->nargs);
+    Move(rax, function->nargs);
   }
   JumpToExternalReference(ExternalReference::Create(fid));
 }
@@ -633,8 +655,8 @@ void MacroAssembler::JumpToExternalReference(const ExternalReference& ext,
                                              bool builtin_exit_frame) {
   // Set the entry point and jump to the C entry runtime stub.
   LoadAddress(rbx, ext);
-  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, kDontSaveFPRegs,
-                                          kArgvOnStack, builtin_exit_frame);
+  Handle<Code> code = CodeFactory::CEntry(isolate(), 1, SaveFPRegsMode::kIgnore,
+                                          ArgvMode::kStack, builtin_exit_frame);
   Jump(code, RelocInfo::CODE_TARGET);
 }
 
@@ -656,7 +678,7 @@ int TurboAssembler::RequiredStackSizeForCallerSaved(SaveFPRegsMode fp_mode,
   }
 
   // R12 to r15 are callee save on all platforms.
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     bytes += kDoubleSize * XMMRegister::kNumRegisters;
   }
 
@@ -678,7 +700,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
   }
 
   // R12 to r15 are callee save on all platforms.
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     int delta = kDoubleSize * XMMRegister::kNumRegisters;
     AllocateStackSpace(delta);
     for (int i = 0; i < XMMRegister::kNumRegisters; i++) {
@@ -694,7 +716,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
 int TurboAssembler::PopCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
                                    Register exclusion2, Register exclusion3) {
   int bytes = 0;
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     for (int i = 0; i < XMMRegister::kNumRegisters; i++) {
       XMMRegister reg = XMMRegister::from_code(i);
       Movsd(reg, Operand(rsp, i * kDoubleSize));
@@ -715,6 +737,24 @@ int TurboAssembler::PopCallerSaved(SaveFPRegsMode fp_mode, Register exclusion1,
   return bytes;
 }
 
+void TurboAssembler::Movq(XMMRegister dst, Register src) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope avx_scope(this, AVX);
+    vmovq(dst, src);
+  } else {
+    movq(dst, src);
+  }
+}
+
+void TurboAssembler::Movq(Register dst, XMMRegister src) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope avx_scope(this, AVX);
+    vmovq(dst, src);
+  } else {
+    movq(dst, src);
+  }
+}
+
 void TurboAssembler::Movdqa(XMMRegister dst, Operand src) {
   // See comments in Movdqa(XMMRegister, XMMRegister).
   if (CpuFeatures::IsSupported(AVX)) {
@@ -1033,7 +1073,7 @@ void ConvertFloatToUint64(TurboAssembler* tasm, Register dst,
   // The input value is within uint64 range and the second conversion worked
   // successfully, but we still have to undo the subtraction we did
   // earlier.
-  tasm->Set(kScratchRegister, 0x8000000000000000);
+  tasm->Move(kScratchRegister, 0x8000000000000000);
   tasm->orq(dst, kScratchRegister);
   tasm->bind(&success);
 }
@@ -1055,26 +1095,6 @@ void TurboAssembler::Cvttss2uiq(Register dst, XMMRegister src, Label* fail) {
   ConvertFloatToUint64<XMMRegister, false>(this, dst, src, fail);
 }
 
-void TurboAssembler::Set(Register dst, int64_t x) {
-  if (x == 0) {
-    xorl(dst, dst);
-  } else if (is_uint32(x)) {
-    movl(dst, Immediate(static_cast<uint32_t>(x)));
-  } else if (is_int32(x)) {
-    movq(dst, Immediate(static_cast<int32_t>(x)));
-  } else {
-    movq(dst, x);
-  }
-}
-
-void TurboAssembler::Set(Operand dst, intptr_t x) {
-  if (is_int32(x)) {
-    movq(dst, Immediate(static_cast<int32_t>(x)));
-  } else {
-    Set(kScratchRegister, x);
-    movq(dst, kScratchRegister);
-  }
-}
 
 // ----------------------------------------------------------------------------
 // Smi tagging, untagging and tag detection.
@@ -1084,36 +1104,6 @@ Register TurboAssembler::GetSmiConstant(Smi source) {
   return kScratchRegister;
 }
 
-void TurboAssembler::Move(Register dst, Smi source) {
-  STATIC_ASSERT(kSmiTag == 0);
-  int value = source.value();
-  if (value == 0) {
-    xorl(dst, dst);
-  } else if (SmiValuesAre32Bits() || value < 0) {
-    Move(dst, source.ptr(), RelocInfo::NONE);
-  } else {
-    uint32_t uvalue = static_cast<uint32_t>(source.ptr());
-    if (uvalue <= 0xFF) {
-      // Emit shorter instructions for small Smis
-      xorl(dst, dst);
-      movb(dst, Immediate(uvalue));
-    } else {
-      movl(dst, Immediate(uvalue));
-    }
-  }
-}
-
-void TurboAssembler::Move(Register dst, ExternalReference ext) {
-  // TODO(jgruber,v8:8887): Also consider a root-relative load when generating
-  // non-isolate-independent code. In many cases it might be cheaper than
-  // embedding the relocatable value.
-  if (root_array_available_ && options().isolate_independent_code) {
-    IndirectLoadExternalReference(dst, ext);
-    return;
-  }
-  movq(dst, Immediate64(ext.address(), RelocInfo::EXTERNAL_REFERENCE));
-}
-
 void MacroAssembler::Cmp(Register dst, int32_t src) {
   if (src == 0) {
     testl(dst, dst);
@@ -1335,6 +1325,39 @@ void TurboAssembler::Push(Smi source) {
 
 // ----------------------------------------------------------------------------
 
+void TurboAssembler::Move(Register dst, Smi source) {
+  STATIC_ASSERT(kSmiTag == 0);
+  int value = source.value();
+  if (value == 0) {
+    xorl(dst, dst);
+  } else if (SmiValuesAre32Bits() || value < 0) {
+    Move(dst, source.ptr(), RelocInfo::NONE);
+  } else {
+    uint32_t uvalue = static_cast<uint32_t>(source.ptr());
+    Move(dst, uvalue);
+  }
+}
+
+void TurboAssembler::Move(Operand dst, intptr_t x) {
+  if (is_int32(x)) {
+    movq(dst, Immediate(static_cast<int32_t>(x)));
+  } else {
+    Move(kScratchRegister, x);
+    movq(dst, kScratchRegister);
+  }
+}
+
+void TurboAssembler::Move(Register dst, ExternalReference ext) {
+  // TODO(jgruber,v8:8887): Also consider a root-relative load when generating
+  // non-isolate-independent code. In many cases it might be cheaper than
+  // embedding the relocatable value.
+  if (root_array_available_ && options().isolate_independent_code) {
+    IndirectLoadExternalReference(dst, ext);
+    return;
+  }
+  movq(dst, Immediate64(ext.address(), RelocInfo::EXTERNAL_REFERENCE));
+}
+
 void TurboAssembler::Move(Register dst, Register src) {
   if (dst != src) {
     movq(dst, src);
@@ -1342,7 +1365,13 @@ void TurboAssembler::Move(Register dst, Register src) {
 }
 
 void TurboAssembler::Move(Register dst, Operand src) { movq(dst, src); }
-void TurboAssembler::Move(Register dst, Immediate src) { movl(dst, src); }
+void TurboAssembler::Move(Register dst, Immediate src) {
+  if (src.rmode() == RelocInfo::Mode::NONE) {
+    Move(dst, src.value());
+  } else {
+    movl(dst, src);
+  }
+}
 
 void TurboAssembler::Move(XMMRegister dst, XMMRegister src) {
   if (dst != src) {
@@ -1481,7 +1510,7 @@ void TurboAssembler::PushArray(Register array, Register size, Register scratch,
   Register counter = scratch;
   Label loop, entry;
   if (order == PushArrayOrder::kReverse) {
-    Set(counter, 0);
+    Move(counter, 0);
     jmp(&entry);
     bind(&loop);
     Push(Operand(array, counter, times_system_pointer_size, 0));
@@ -1681,7 +1710,7 @@ void TurboAssembler::CallBuiltin(int builtin_index) {
     Move(kScratchRegister, entry, RelocInfo::OFF_HEAP_TARGET);
     call(kScratchRegister);
   }
-  if (FLAG_code_comments) RecordComment("]");
+  RecordComment("]");
 }
 
 void TurboAssembler::TailCallBuiltin(int builtin_index) {
@@ -1698,7 +1727,7 @@ void TurboAssembler::TailCallBuiltin(int builtin_index) {
     Address entry = d.InstructionStartOfBuiltin(builtin_index);
     Jump(entry, RelocInfo::OFF_HEAP_TARGET);
   }
-  if (FLAG_code_comments) RecordComment("]");
+  RecordComment("]");
 }
 
 void TurboAssembler::LoadCodeObjectEntry(Register destination,
@@ -1854,29 +1883,6 @@ void TurboAssembler::Pmaddubsw(XMMRegister dst, XMMRegister src1,
   }
 }
 
-void TurboAssembler::Unpcklps(XMMRegister dst, XMMRegister src1, Operand src2) {
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope avx_scope(this, AVX);
-    vunpcklps(dst, src1, src2);
-  } else {
-    DCHECK_EQ(dst, src1);
-    unpcklps(dst, src2);
-  }
-}
-
-void TurboAssembler::Shufps(XMMRegister dst, XMMRegister src1, XMMRegister src2,
-                            byte imm8) {
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope avx_scope(this, AVX);
-    vshufps(dst, src1, src2, imm8);
-  } else {
-    if (dst != src1) {
-      movaps(dst, src1);
-    }
-    shufps(dst, src2, imm8);
-  }
-}
-
 void TurboAssembler::Pextrd(Register dst, XMMRegister src, uint8_t imm8) {
   if (imm8 == 0) {
     Movd(dst, src);
@@ -2008,36 +2014,6 @@ void TurboAssembler::Pinsrq(XMMRegister dst, XMMRegister src1, Operand src2,
               imm8, base::Optional<CpuFeature>(SSE4_1));
 }
 
-void TurboAssembler::Psllq(XMMRegister dst, byte imm8) {
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    vpsllq(dst, dst, imm8);
-  } else {
-    DCHECK(!IsEnabled(AVX));
-    psllq(dst, imm8);
-  }
-}
-
-void TurboAssembler::Psrlq(XMMRegister dst, byte imm8) {
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    vpsrlq(dst, dst, imm8);
-  } else {
-    DCHECK(!IsEnabled(AVX));
-    psrlq(dst, imm8);
-  }
-}
-
-void TurboAssembler::Pslld(XMMRegister dst, byte imm8) {
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    vpslld(dst, dst, imm8);
-  } else {
-    DCHECK(!IsEnabled(AVX));
-    pslld(dst, imm8);
-  }
-}
-
 void TurboAssembler::Pblendvb(XMMRegister dst, XMMRegister src1,
                               XMMRegister src2, XMMRegister mask) {
   if (CpuFeatures::IsSupported(AVX)) {
@@ -2375,21 +2351,6 @@ void TurboAssembler::Negpd(XMMRegister dst) {
                  ExternalReference::address_of_double_neg_constant()));
 }
 
-void TurboAssembler::Psrld(XMMRegister dst, byte imm8) {
-  Psrld(dst, dst, imm8);
-}
-
-void TurboAssembler::Psrld(XMMRegister dst, XMMRegister src, byte imm8) {
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    vpsrld(dst, src, imm8);
-  } else {
-    DCHECK(!IsEnabled(AVX));
-    DCHECK_EQ(dst, src);
-    psrld(dst, imm8);
-  }
-}
-
 void TurboAssembler::Lzcntl(Register dst, Register src) {
   if (CpuFeatures::IsSupported(LZCNT)) {
     CpuFeatureScope scope(this, LZCNT);
@@ -2593,28 +2554,28 @@ void MacroAssembler::CmpInstanceTypeRange(Register map,
 }
 
 void MacroAssembler::AssertNotSmi(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Condition is_smi = CheckSmi(object);
     Check(NegateCondition(is_smi), AbortReason::kOperandIsASmi);
   }
 }
 
 void MacroAssembler::AssertSmi(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Condition is_smi = CheckSmi(object);
     Check(is_smi, AbortReason::kOperandIsNotASmi);
   }
 }
 
 void MacroAssembler::AssertSmi(Operand object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Condition is_smi = CheckSmi(object);
     Check(is_smi, AbortReason::kOperandIsNotASmi);
   }
 }
 
 void TurboAssembler::AssertZeroExtended(Register int32_register) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     DCHECK_NE(int32_register, kScratchRegister);
     movq(kScratchRegister, int64_t{0x0000000100000000});
     cmpq(kScratchRegister, int32_register);
@@ -2623,7 +2584,7 @@ void TurboAssembler::AssertZeroExtended(Register int32_register) {
 }
 
 void MacroAssembler::AssertConstructor(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     testb(object, Immediate(kSmiTagMask));
     Check(not_equal, AbortReason::kOperandIsASmiAndNotAConstructor);
     Push(object);
@@ -2636,7 +2597,7 @@ void MacroAssembler::AssertConstructor(Register object) {
 }
 
 void MacroAssembler::AssertFunction(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     testb(object, Immediate(kSmiTagMask));
     Check(not_equal, AbortReason::kOperandIsASmiAndNotAFunction);
     Push(object);
@@ -2648,7 +2609,7 @@ void MacroAssembler::AssertFunction(Register object) {
 }
 
 void MacroAssembler::AssertBoundFunction(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     testb(object, Immediate(kSmiTagMask));
     Check(not_equal, AbortReason::kOperandIsASmiAndNotABoundFunction);
     Push(object);
@@ -2659,7 +2620,7 @@ void MacroAssembler::AssertBoundFunction(Register object) {
 }
 
 void MacroAssembler::AssertGeneratorObject(Register object) {
-  if (!emit_debug_code()) return;
+  if (!FLAG_debug_code) return;
   testb(object, Immediate(kSmiTagMask));
   Check(not_equal, AbortReason::kOperandIsASmiAndNotAGeneratorObject);
 
@@ -2687,12 +2648,16 @@ void MacroAssembler::AssertGeneratorObject(Register object) {
 }
 
 void MacroAssembler::AssertUndefinedOrAllocationSite(Register object) {
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     Label done_checking;
     AssertNotSmi(object);
     Cmp(object, isolate()->factory()->undefined_value());
     j(equal, &done_checking);
-    Cmp(FieldOperand(object, 0), isolate()->factory()->allocation_site_map());
+    Register map = object;
+    Push(object);
+    LoadMap(map, object);
+    Cmp(map, isolate()->factory()->allocation_site_map());
+    Pop(object);
     Assert(equal, AbortReason::kExpectedUndefinedOrCell);
     bind(&done_checking);
   }
@@ -2737,20 +2702,6 @@ void MacroAssembler::DecrementCounter(StatsCounter* counter, int value) {
   }
 }
 
-void MacroAssembler::MaybeDropFrames() {
-  // Check whether we need to drop frames to restart a function on the stack.
-  ExternalReference restart_fp =
-      ExternalReference::debug_restart_fp_address(isolate());
-  Load(rbx, restart_fp);
-  testq(rbx, rbx);
-
-  Label dont_drop;
-  j(zero, &dont_drop, Label::kNear);
-  Jump(BUILTIN_CODE(isolate(), FrameDropperTrampoline), RelocInfo::CODE_TARGET);
-
-  bind(&dont_drop);
-}
-
 void TurboAssembler::PrepareForTailCall(Register callee_args_count,
                                         Register caller_args_count,
                                         Register scratch0, Register scratch1) {
@@ -2801,32 +2752,32 @@ void TurboAssembler::PrepareForTailCall(Register callee_args_count,
 
 void MacroAssembler::InvokeFunction(Register function, Register new_target,
                                     Register actual_parameter_count,
-                                    InvokeFlag flag) {
+                                    InvokeType type) {
   LoadTaggedPointerField(
       rbx, FieldOperand(function, JSFunction::kSharedFunctionInfoOffset));
   movzxwq(rbx,
           FieldOperand(rbx, SharedFunctionInfo::kFormalParameterCountOffset));
 
-  InvokeFunction(function, new_target, rbx, actual_parameter_count, flag);
+  InvokeFunction(function, new_target, rbx, actual_parameter_count, type);
 }
 
 void MacroAssembler::InvokeFunction(Register function, Register new_target,
                                     Register expected_parameter_count,
                                     Register actual_parameter_count,
-                                    InvokeFlag flag) {
-  DCHECK(function == rdi);
+                                    InvokeType type) {
+  DCHECK_EQ(function, rdi);
   LoadTaggedPointerField(rsi,
                          FieldOperand(function, JSFunction::kContextOffset));
   InvokeFunctionCode(rdi, new_target, expected_parameter_count,
-                     actual_parameter_count, flag);
+                     actual_parameter_count, type);
 }
 
 void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
                                         Register expected_parameter_count,
                                         Register actual_parameter_count,
-                                        InvokeFlag flag) {
+                                        InvokeType type) {
   // You can't call a function without a valid frame.
-  DCHECK_IMPLIES(flag == CALL_FUNCTION, has_frame());
+  DCHECK_IMPLIES(type == InvokeType::kCall, has_frame());
   DCHECK_EQ(function, rdi);
   DCHECK_IMPLIES(new_target.is_valid(), new_target == rdx);
 
@@ -2848,17 +2799,19 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
   }
 
   Label done;
-  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, flag);
+  InvokePrologue(expected_parameter_count, actual_parameter_count, &done, type);
   // We call indirectly through the code field in the function to
   // allow recompilation to take effect without changing any of the
   // call sites.
   static_assert(kJavaScriptCallCodeStartRegister == rcx, "ABI mismatch");
   LoadTaggedPointerField(rcx, FieldOperand(function, JSFunction::kCodeOffset));
-  if (flag == CALL_FUNCTION) {
-    CallCodeObject(rcx);
-  } else {
-    DCHECK(flag == JUMP_FUNCTION);
-    JumpCodeObject(rcx);
+  switch (type) {
+    case InvokeType::kCall:
+      CallCodeObject(rcx);
+      break;
+    case InvokeType::kJump:
+      JumpCodeObject(rcx);
+      break;
   }
   jmp(&done, Label::kNear);
 
@@ -2911,7 +2864,7 @@ void MacroAssembler::StackOverflowCheck(
 
 void MacroAssembler::InvokePrologue(Register expected_parameter_count,
                                     Register actual_parameter_count,
-                                    Label* done, InvokeFlag flag) {
+                                    Label* done, InvokeType type) {
   if (expected_parameter_count != actual_parameter_count) {
     Label regular_invoke;
     // If the expected parameter count is equal to the adaptor sentinel, no need
@@ -2937,9 +2890,9 @@ void MacroAssembler::InvokePrologue(Register expected_parameter_count,
            Operand(expected_parameter_count, times_system_pointer_size, 0));
       AllocateStackSpace(kScratchRegister);
       // Extra words are the receiver and the return address (if a jump).
-      int extra_words = flag == CALL_FUNCTION ? 1 : 2;
+      int extra_words = type == InvokeType::kCall ? 1 : 2;
       leaq(num, Operand(rax, extra_words));  // Number of words to copy.
-      Set(current, 0);
+      Move(current, 0);
       // Fall-through to the loop body because there are non-zero words to copy.
       bind(&copy);
       movq(kScratchRegister,
@@ -3034,7 +2987,7 @@ void TurboAssembler::LeaveFrame(StackFrame::Type type) {
   // TODO(v8:11429): Consider passing BASELINE instead, and checking for
   // IsJSFrame or similar. Could then unify with manual frame leaves in the
   // interpreter too.
-  if (emit_debug_code() && !StackFrame::IsJavaScript(type)) {
+  if (FLAG_debug_code && !StackFrame::IsJavaScript(type)) {
     cmpq(Operand(rbp, CommonFrameConstants::kContextOrFrameTypeOffset),
          Immediate(StackFrame::TypeToMarker(type)));
     Check(equal, AbortReason::kStackFrameTypesMustMatch);
@@ -3043,11 +2996,11 @@ void TurboAssembler::LeaveFrame(StackFrame::Type type) {
   popq(rbp);
 }
 
-#ifdef V8_TARGET_OS_WIN
+#if defined(V8_TARGET_OS_WIN) || defined(V8_TARGET_OS_MACOSX)
 void TurboAssembler::AllocateStackSpace(Register bytes_scratch) {
-  // In windows, we cannot increment the stack size by more than one page
-  // (minimum page size is 4KB) without accessing at least one byte on the
-  // page. Check this:
+  // On Windows and on macOS, we cannot increment the stack size by more than
+  // one page (minimum page size is 4KB) without accessing at least one byte on
+  // the page. Check this:
   // https://msdn.microsoft.com/en-us/library/aa227153(v=vs.60).aspx.
   Label check_offset;
   Label touch_next_page;
@@ -3278,7 +3231,7 @@ void TurboAssembler::CallCFunction(Register function, int num_arguments) {
   DCHECK_LE(num_arguments, kMaxCParameters);
   DCHECK(has_frame());
   // Check stack alignment.
-  if (emit_debug_code()) {
+  if (FLAG_debug_code) {
     CheckStackAlignment();
   }
 
@@ -3376,7 +3329,7 @@ void TurboAssembler::ComputeCodeStartAddress(Register dst) {
 
 void TurboAssembler::ResetSpeculationPoisonRegister() {
   // TODO(turbofan): Perhaps, we want to put an lfence here.
-  Set(kSpeculationPoisonRegister, -1);
+  Move(kSpeculationPoisonRegister, -1);
 }
 
 void TurboAssembler::CallForDeoptimization(Builtins::Name target, int,
diff --git a/chromium/v8/src/codegen/x64/macro-assembler-x64.h b/chromium/v8/src/codegen/x64/macro-assembler-x64.h
index 40ab1b925c8..da5cf7dae37 100644
--- a/chromium/v8/src/codegen/x64/macro-assembler-x64.h
+++ b/chromium/v8/src/codegen/x64/macro-assembler-x64.h
@@ -14,6 +14,7 @@
 #include "src/codegen/shared-ia32-x64/macro-assembler-shared-ia32-x64.h"
 #include "src/codegen/x64/assembler-x64.h"
 #include "src/common/globals.h"
+#include "src/execution/isolate-data.h"
 #include "src/objects/contexts.h"
 #include "src/objects/tagged-index.h"
 
@@ -25,9 +26,6 @@ using MemOperand = Operand;
 
 class StringConstantBase;
 
-enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
-enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
-
 struct SmiIndex {
   SmiIndex(Register index_register, ScaleFactor scale)
       : reg(index_register), scale(scale) {}
@@ -65,124 +63,43 @@ class V8_EXPORT_PRIVATE TurboAssembler : public SharedTurboAssembler {
   AVX_OP(Subsd, subsd)
   AVX_OP(Divss, divss)
   AVX_OP(Divsd, divsd)
-  AVX_OP(Orps, orps)
-  AVX_OP(Xorps, xorps)
-  AVX_OP(Xorpd, xorpd)
-  AVX_OP(Movq, movq)
-  AVX_OP(Movhlps, movhlps)
-  AVX_OP(Pcmpeqb, pcmpeqb)
-  AVX_OP(Pcmpeqw, pcmpeqw)
-  AVX_OP(Pcmpeqd, pcmpeqd)
-  AVX_OP(Pcmpgtb, pcmpgtb)
   AVX_OP(Pcmpgtw, pcmpgtw)
   AVX_OP(Pmaxsw, pmaxsw)
-  AVX_OP(Pmaxub, pmaxub)
   AVX_OP(Pminsw, pminsw)
-  AVX_OP(Pminub, pminub)
   AVX_OP(Addss, addss)
   AVX_OP(Addsd, addsd)
   AVX_OP(Mulsd, mulsd)
-  AVX_OP(Andps, andps)
-  AVX_OP(Andnps, andnps)
-  AVX_OP(Andpd, andpd)
-  AVX_OP(Andnpd, andnpd)
-  AVX_OP(Orpd, orpd)
   AVX_OP(Cmpeqps, cmpeqps)
   AVX_OP(Cmpltps, cmpltps)
-  AVX_OP(Cmpleps, cmpleps)
   AVX_OP(Cmpneqps, cmpneqps)
   AVX_OP(Cmpnltps, cmpnltps)
   AVX_OP(Cmpnleps, cmpnleps)
-  AVX_OP(Cmpeqpd, cmpeqpd)
-  AVX_OP(Cmpltpd, cmpltpd)
-  AVX_OP(Cmplepd, cmplepd)
-  AVX_OP(Cmpneqpd, cmpneqpd)
   AVX_OP(Cmpnltpd, cmpnltpd)
   AVX_OP(Cmpnlepd, cmpnlepd)
-  AVX_OP(Sqrtss, sqrtss)
-  AVX_OP(Sqrtsd, sqrtsd)
   AVX_OP(Cvttpd2dq, cvttpd2dq)
   AVX_OP(Ucomiss, ucomiss)
   AVX_OP(Ucomisd, ucomisd)
-  AVX_OP(Pand, pand)
-  AVX_OP(Por, por)
-  AVX_OP(Pxor, pxor)
-  AVX_OP(Psubb, psubb)
-  AVX_OP(Psubw, psubw)
-  AVX_OP(Psubd, psubd)
-  AVX_OP(Psubq, psubq)
-  AVX_OP(Psubsb, psubsb)
   AVX_OP(Psubsw, psubsw)
-  AVX_OP(Psubusb, psubusb)
   AVX_OP(Psubusw, psubusw)
-  AVX_OP(Pslld, pslld)
-  AVX_OP(Pavgb, pavgb)
-  AVX_OP(Pavgw, pavgw)
-  AVX_OP(Psraw, psraw)
-  AVX_OP(Psrad, psrad)
-  AVX_OP(Psllw, psllw)
-  AVX_OP(Psllq, psllq)
-  AVX_OP(Psrlw, psrlw)
-  AVX_OP(Psrld, psrld)
-  AVX_OP(Psrlq, psrlq)
-  AVX_OP(Paddb, paddb)
-  AVX_OP(Paddw, paddw)
-  AVX_OP(Paddd, paddd)
-  AVX_OP(Paddq, paddq)
-  AVX_OP(Paddsb, paddsb)
   AVX_OP(Paddsw, paddsw)
-  AVX_OP(Paddusb, paddusb)
-  AVX_OP(Paddusw, paddusw)
   AVX_OP(Pcmpgtd, pcmpgtd)
-  AVX_OP(Pmuludq, pmuludq)
-  AVX_OP(Addpd, addpd)
-  AVX_OP(Subpd, subpd)
-  AVX_OP(Mulpd, mulpd)
-  AVX_OP(Minps, minps)
-  AVX_OP(Minpd, minpd)
-  AVX_OP(Divpd, divpd)
-  AVX_OP(Maxps, maxps)
-  AVX_OP(Maxpd, maxpd)
-  AVX_OP(Addps, addps)
-  AVX_OP(Subps, subps)
-  AVX_OP(Mulps, mulps)
-  AVX_OP(Divps, divps)
-  AVX_OP(Packsswb, packsswb)
-  AVX_OP(Packuswb, packuswb)
-  AVX_OP(Packssdw, packssdw)
-  AVX_OP(Punpcklbw, punpcklbw)
-  AVX_OP(Punpcklwd, punpcklwd)
-  AVX_OP(Punpckldq, punpckldq)
-  AVX_OP(Punpckhbw, punpckhbw)
-  AVX_OP(Punpckhwd, punpckhwd)
-  AVX_OP(Punpckhdq, punpckhdq)
-  AVX_OP(Punpcklqdq, punpcklqdq)
-  AVX_OP(Punpckhqdq, punpckhqdq)
-  AVX_OP(Cmpps, cmpps)
-  AVX_OP(Cmppd, cmppd)
+  AVX_OP(Pcmpeqb, pcmpeqb)
+  AVX_OP(Pcmpeqw, pcmpeqw)
+  AVX_OP(Pcmpeqd, pcmpeqd)
   AVX_OP(Movlhps, movlhps)
-  AVX_OP_SSE3(Haddps, haddps)
   AVX_OP_SSSE3(Phaddd, phaddd)
   AVX_OP_SSSE3(Phaddw, phaddw)
   AVX_OP_SSSE3(Pshufb, pshufb)
-  AVX_OP_SSSE3(Psignb, psignb)
-  AVX_OP_SSSE3(Psignw, psignw)
-  AVX_OP_SSSE3(Psignd, psignd)
-  AVX_OP_SSSE3(Palignr, palignr)
   AVX_OP_SSE4_1(Pcmpeqq, pcmpeqq)
   AVX_OP_SSE4_1(Packusdw, packusdw)
-  AVX_OP_SSE4_1(Pminsb, pminsb)
   AVX_OP_SSE4_1(Pminsd, pminsd)
   AVX_OP_SSE4_1(Pminuw, pminuw)
   AVX_OP_SSE4_1(Pminud, pminud)
-  AVX_OP_SSE4_1(Pmaxsb, pmaxsb)
-  AVX_OP_SSE4_1(Pmaxsd, pmaxsd)
   AVX_OP_SSE4_1(Pmaxuw, pmaxuw)
   AVX_OP_SSE4_1(Pmaxud, pmaxud)
   AVX_OP_SSE4_1(Pmulld, pmulld)
   AVX_OP_SSE4_1(Insertps, insertps)
   AVX_OP_SSE4_1(Pinsrq, pinsrq)
-  AVX_OP_SSE4_1(Pblendw, pblendw)
   AVX_OP_SSE4_1(Pextrq, pextrq)
   AVX_OP_SSE4_1(Roundss, roundss)
   AVX_OP_SSE4_1(Roundsd, roundsd)
@@ -190,6 +107,12 @@ class V8_EXPORT_PRIVATE TurboAssembler : public SharedTurboAssembler {
 
 #undef AVX_OP
 
+  // Define movq here instead of using AVX_OP. movq is defined using templates
+  // and there is a function template `void movq(P1)`, while technically
+  // impossible, will be selected when deducing the arguments for AvxHelper.
+  void Movq(XMMRegister dst, Register src);
+  void Movq(Register dst, XMMRegister src);
+
   void PushReturnAddressFrom(Register src) { pushq(src); }
   void PopReturnAddressTo(Register dst) { popq(dst); }
 
@@ -199,10 +122,6 @@ class V8_EXPORT_PRIVATE TurboAssembler : public SharedTurboAssembler {
   // may be bigger than 2^16 - 1.  Requires a scratch register.
   void Ret(int bytes_dropped, Register scratch);
 
-  // Load a register with a long value as efficiently as possible.
-  void Set(Register dst, int64_t x);
-  void Set(Operand dst, intptr_t x);
-
   // Operations on roots in the root-array.
   void LoadRoot(Register destination, RootIndex index) override;
   void LoadRoot(Operand destination, RootIndex index) {
@@ -323,8 +242,28 @@ class V8_EXPORT_PRIVATE TurboAssembler : public SharedTurboAssembler {
     j(less, dest);
   }
 
+#ifdef V8_MAP_PACKING
+  void UnpackMapWord(Register r);
+#endif
+
   void LoadMap(Register destination, Register object);
 
+  void Move(Register dst, intptr_t x) {
+    if (x == 0) {
+      xorl(dst, dst);
+    } else if (is_uint8(x)) {
+      xorl(dst, dst);
+      movb(dst, Immediate(static_cast<uint32_t>(x)));
+    } else if (is_uint32(x)) {
+      movl(dst, Immediate(static_cast<uint32_t>(x)));
+    } else if (is_int32(x)) {
+      // "movq reg64, imm32" is sign extending.
+      movq(dst, Immediate(static_cast<int32_t>(x)));
+    } else {
+      movq(dst, Immediate64(x));
+    }
+  }
+  void Move(Operand dst, intptr_t x);
   void Move(Register dst, Smi source);
 
   void Move(Operand dst, Smi source) {
@@ -332,13 +271,9 @@ class V8_EXPORT_PRIVATE TurboAssembler : public SharedTurboAssembler {
     movq(dst, constant);
   }
 
-  void Move(Register dst, TaggedIndex source) {
-    movl(dst, Immediate(static_cast<uint32_t>(source.ptr())));
-  }
+  void Move(Register dst, TaggedIndex source) { Move(dst, source.ptr()); }
 
-  void Move(Operand dst, TaggedIndex source) {
-    movl(dst, Immediate(static_cast<uint32_t>(source.ptr())));
-  }
+  void Move(Operand dst, TaggedIndex source) { Move(dst, source.ptr()); }
 
   void Move(Register dst, ExternalReference ext);
 
@@ -449,10 +384,6 @@ class V8_EXPORT_PRIVATE TurboAssembler : public SharedTurboAssembler {
   void Pmaddubsw(XMMRegister dst, XMMRegister src1, Operand src2);
   void Pmaddubsw(XMMRegister dst, XMMRegister src1, XMMRegister src2);
 
-  void Unpcklps(XMMRegister dst, XMMRegister src1, Operand src2);
-  // Shufps that will mov src1 into dst if AVX is not supported.
-  void Shufps(XMMRegister dst, XMMRegister src1, XMMRegister src2, byte imm8);
-
   // Non-SSE2 instructions.
   void Pextrd(Register dst, XMMRegister src, uint8_t imm8);
 
@@ -467,16 +398,6 @@ class V8_EXPORT_PRIVATE TurboAssembler : public SharedTurboAssembler {
   void Pinsrq(XMMRegister dst, XMMRegister src1, Register src2, uint8_t imm8);
   void Pinsrq(XMMRegister dst, XMMRegister src1, Operand src2, uint8_t imm8);
 
-  void Psllq(XMMRegister dst, int imm8) { Psllq(dst, static_cast<byte>(imm8)); }
-  void Psllq(XMMRegister dst, byte imm8);
-  void Psrlq(XMMRegister dst, int imm8) { Psrlq(dst, static_cast<byte>(imm8)); }
-  void Psrlq(XMMRegister dst, byte imm8);
-  void Pslld(XMMRegister dst, byte imm8);
-  void Psrld(XMMRegister dst, byte imm8);
-
-  // Supports both AVX (dst != src1) and SSE (checks that dst == src1).
-  void Psrld(XMMRegister dst, XMMRegister src, byte imm8);
-
   void Pblendvb(XMMRegister dst, XMMRegister src1, XMMRegister src2,
                 XMMRegister mask);
   void Blendvps(XMMRegister dst, XMMRegister src1, XMMRegister src2,
@@ -551,7 +472,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public SharedTurboAssembler {
 // stack check, do it before calling this function because this function may
 // write into the newly allocated space. It may also overwrite the given
 // register's value, in the version that takes a register.
-#ifdef V8_TARGET_OS_WIN
+#if defined(V8_TARGET_OS_WIN) || defined(V8_TARGET_OS_MACOSX)
   void AllocateStackSpace(Register bytes_scratch);
   void AllocateStackSpace(int bytes);
 #else
@@ -575,7 +496,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public SharedTurboAssembler {
     ExternalReference isolate_root = ExternalReference::isolate_root(isolate());
     Move(kRootRegister, isolate_root);
 #ifdef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
-    Move(kPointerCageBaseRegister, isolate_root);
+    LoadRootRelative(kPtrComprCageBaseRegister,
+                     IsolateData::cage_base_offset());
 #endif
   }
 
@@ -675,10 +597,13 @@ class V8_EXPORT_PRIVATE TurboAssembler : public SharedTurboAssembler {
   // ---------------------------------------------------------------------------
   // V8 Heap sandbox support
 
+  enum class IsolateRootLocation { kInScratchRegister, kInRootRegister };
   // Loads a field containing off-heap pointer and does necessary decoding
   // if V8 heap sandbox is enabled.
   void LoadExternalPointerField(Register destination, Operand field_operand,
-                                ExternalPointerTag tag);
+                                ExternalPointerTag tag, Register scratch,
+                                IsolateRootLocation isolateRootLocation =
+                                    IsolateRootLocation::kInRootRegister);
 
  protected:
   static const int kSmiShift = kSmiTagSize + kSmiShiftSize;
@@ -751,8 +676,8 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   void RecordWriteField(
       Register object, int offset, Register value, Register scratch,
       SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
   // For page containing |object| mark region covering |address|
   // dirty. |object| is the object being stored into, |value| is the
@@ -761,11 +686,8 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // the write barrier if the value is a smi.
   void RecordWrite(
       Register object, Register address, Register value, SaveFPRegsMode save_fp,
-      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
-      SmiCheck smi_check = INLINE_SMI_CHECK);
-
-  // Frame restart support.
-  void MaybeDropFrames();
+      RememberedSetAction remembered_set_action = RememberedSetAction::kEmit,
+      SmiCheck smi_check = SmiCheck::kInline);
 
   // Enter specific kind of exit frame; either in normal or
   // debug mode. Expects the number of arguments in register rax and
@@ -797,7 +719,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // Invoke the JavaScript function code by either calling or jumping.
   void InvokeFunctionCode(Register function, Register new_target,
                           Register expected_parameter_count,
-                          Register actual_parameter_count, InvokeFlag flag);
+                          Register actual_parameter_count, InvokeType type);
 
   // On function call, call into the debugger.
   void CallDebugOnFunctionCall(Register fun, Register new_target,
@@ -807,11 +729,11 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // Invoke the JavaScript function in the given register. Changes the
   // current context to the context in the function before invoking.
   void InvokeFunction(Register function, Register new_target,
-                      Register actual_parameter_count, InvokeFlag flag);
+                      Register actual_parameter_count, InvokeType type);
 
   void InvokeFunction(Register function, Register new_target,
                       Register expected_parameter_count,
-                      Register actual_parameter_count, InvokeFlag flag);
+                      Register actual_parameter_count, InvokeType type);
 
   // ---------------------------------------------------------------------------
   // Conversions between tagged smi values and non-tagged integer values.
@@ -975,18 +897,18 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
 
   // Call a runtime routine.
   void CallRuntime(const Runtime::Function* f, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs);
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore);
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId fid,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     const Runtime::Function* function = Runtime::FunctionForId(fid);
     CallRuntime(function, function->nargs, save_doubles);
   }
 
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId fid, int num_arguments,
-                   SaveFPRegsMode save_doubles = kDontSaveFPRegs) {
+                   SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore) {
     CallRuntime(Runtime::FunctionForId(fid), num_arguments, save_doubles);
   }
 
@@ -1017,7 +939,7 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // Helper functions for generating invokes.
   void InvokePrologue(Register expected_parameter_count,
                       Register actual_parameter_count, Label* done,
-                      InvokeFlag flag);
+                      InvokeType type);
 
   void EnterExitFramePrologue(Register saved_rax_reg,
                               StackFrame::Type frame_type);
diff --git a/chromium/v8/src/codegen/x64/register-x64.h b/chromium/v8/src/codegen/x64/register-x64.h
index 9a812d06a1b..61e7ccf396a 100644
--- a/chromium/v8/src/codegen/x64/register-x64.h
+++ b/chromium/v8/src/codegen/x64/register-x64.h
@@ -212,7 +212,7 @@ constexpr Register kReturnRegister2 = r8;
 constexpr Register kJSFunctionRegister = rdi;
 constexpr Register kContextRegister = rsi;
 constexpr Register kAllocateSizeRegister = rdx;
-constexpr Register kSpeculationPoisonRegister = r12;
+constexpr Register kSpeculationPoisonRegister = r11;
 constexpr Register kInterpreterAccumulatorRegister = rax;
 constexpr Register kInterpreterBytecodeOffsetRegister = r9;
 constexpr Register kInterpreterBytecodeArrayRegister = r12;
@@ -236,9 +236,9 @@ constexpr Register kScratchRegister = r10;
 constexpr XMMRegister kScratchDoubleReg = xmm15;
 constexpr Register kRootRegister = r13;  // callee save
 #ifdef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
-constexpr Register kPointerCageBaseRegister = r14;  // callee save
+constexpr Register kPtrComprCageBaseRegister = r14;  // callee save
 #else
-constexpr Register kPointerCageBaseRegister = kRootRegister;
+constexpr Register kPtrComprCageBaseRegister = kRootRegister;
 #endif
 
 constexpr Register kOffHeapTrampolineRegister = kScratchRegister;
diff --git a/chromium/v8/src/common/external-pointer-inl.h b/chromium/v8/src/common/external-pointer-inl.h
index bc7aea3691b..737bd55e5ca 100644
--- a/chromium/v8/src/common/external-pointer-inl.h
+++ b/chromium/v8/src/common/external-pointer-inl.h
@@ -12,20 +12,13 @@
 namespace v8 {
 namespace internal {
 
-V8_INLINE Address DecodeExternalPointer(PtrComprCageBase isolate_root,
+V8_INLINE Address DecodeExternalPointer(const Isolate* isolate,
                                         ExternalPointer_t encoded_pointer,
                                         ExternalPointerTag tag) {
   STATIC_ASSERT(kExternalPointerSize == kSystemPointerSize);
 #ifdef V8_HEAP_SANDBOX
-
-  // TODO(syg): V8_HEAP_SANDBOX doesn't work with pointer cage
-#ifdef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
-#error "V8_HEAP_SANDBOX requires per-Isolate pointer compression cage"
-#endif
-
   uint32_t index = static_cast<uint32_t>(encoded_pointer);
-  const Isolate* isolate = Isolate::FromRootAddress(isolate_root.address());
-  return isolate->external_pointer_table().get(index) ^ tag;
+  return isolate->external_pointer_table().get(index) & ~tag;
 #else
   return encoded_pointer;
 #endif
@@ -47,9 +40,10 @@ V8_INLINE void InitExternalPointerField(Address field_address,
 V8_INLINE void InitExternalPointerField(Address field_address, Isolate* isolate,
                                         Address value, ExternalPointerTag tag) {
 #ifdef V8_HEAP_SANDBOX
+  DCHECK_EQ(value & kExternalPointerTagMask, 0);
   ExternalPointer_t index = isolate->external_pointer_table().allocate();
   isolate->external_pointer_table().set(static_cast<uint32_t>(index),
-                                        value ^ tag);
+                                        value | tag);
   static_assert(kExternalPointerSize == kSystemPointerSize,
                 "Review the code below, once kExternalPointerSize is 4-byte "
                 "the address of the field will always be aligned");
@@ -68,7 +62,7 @@ V8_INLINE void InitExternalPointerField(Address field_address, Isolate* isolate,
 }
 
 V8_INLINE Address ReadExternalPointerField(Address field_address,
-                                           PtrComprCageBase cage_base,
+                                           const Isolate* isolate,
                                            ExternalPointerTag tag) {
   // Pointer compression causes types larger than kTaggedSize to be unaligned.
   constexpr bool v8_pointer_compression_unaligned =
@@ -79,7 +73,7 @@ V8_INLINE Address ReadExternalPointerField(Address field_address,
   } else {
     encoded_value = base::Memory<ExternalPointer_t>(field_address);
   }
-  return DecodeExternalPointer(cage_base, encoded_value, tag);
+  return DecodeExternalPointer(isolate, encoded_value, tag);
 }
 
 V8_INLINE void WriteExternalPointerField(Address field_address,
@@ -89,11 +83,12 @@ V8_INLINE void WriteExternalPointerField(Address field_address,
   static_assert(kExternalPointerSize == kSystemPointerSize,
                 "Review the code below, once kExternalPointerSize is 4-byte "
                 "the address of the field will always be aligned");
+  DCHECK_EQ(value & kExternalPointerTagMask, 0);
 
   ExternalPointer_t index =
       base::ReadUnalignedValue<ExternalPointer_t>(field_address);
   isolate->external_pointer_table().set(static_cast<uint32_t>(index),
-                                        value ^ tag);
+                                        value | tag);
 #else
   // Pointer compression causes types larger than kTaggedSize to be unaligned.
   constexpr bool v8_pointer_compression_unaligned =
diff --git a/chromium/v8/src/common/external-pointer.h b/chromium/v8/src/common/external-pointer.h
index c0941f29782..5c1995749c1 100644
--- a/chromium/v8/src/common/external-pointer.h
+++ b/chromium/v8/src/common/external-pointer.h
@@ -12,7 +12,7 @@ namespace internal {
 
 // Convert external pointer from on-V8-heap representation to an actual external
 // pointer value.
-V8_INLINE Address DecodeExternalPointer(PtrComprCageBase isolate,
+V8_INLINE Address DecodeExternalPointer(const Isolate* isolate,
                                         ExternalPointer_t encoded_pointer,
                                         ExternalPointerTag tag);
 
@@ -34,7 +34,7 @@ V8_INLINE void InitExternalPointerField(Address field_address, Isolate* isolate,
 // Reads external pointer for the field, and decodes it if the sandbox is
 // enabled.
 V8_INLINE Address ReadExternalPointerField(Address field_address,
-                                           PtrComprCageBase isolate,
+                                           const Isolate* isolate,
                                            ExternalPointerTag tag);
 
 // Encodes value if the sandbox is enabled and writes it into the field.
diff --git a/chromium/v8/src/common/globals.h b/chromium/v8/src/common/globals.h
index f51c3210f8c..1be0efd0236 100644
--- a/chromium/v8/src/common/globals.h
+++ b/chromium/v8/src/common/globals.h
@@ -209,6 +209,15 @@ constexpr int kElidedFrameSlots = 0;
 #endif
 
 constexpr int kDoubleSizeLog2 = 3;
+// The maximal length of the string representation for a double value
+// (e.g. "-2.2250738585072020E-308"). It is composed as follows:
+// - 17 decimal digits, see kBase10MaximalLength (dtoa.h)
+// - 1 sign
+// - 1 decimal point
+// - 1 E or e
+// - 1 exponent sign
+// - 3 exponent
+constexpr int kMaxDoubleStringLength = 24;
 
 // Total wasm code space per engine (i.e. per process) is limited to make
 // certain attacks that rely on heap spraying harder.
@@ -457,11 +466,11 @@ inline LanguageMode stricter_language_mode(LanguageMode mode1,
 // a keyed store is of the form a[expression] = foo.
 enum class StoreOrigin { kMaybeKeyed, kNamed };
 
-enum TypeofMode : int { INSIDE_TYPEOF, NOT_INSIDE_TYPEOF };
+enum class TypeofMode { kInside, kNotInside };
 
 // Enums used by CEntry.
-enum SaveFPRegsMode { kDontSaveFPRegs, kSaveFPRegs };
-enum ArgvMode { kArgvOnStack, kArgvInRegister };
+enum class SaveFPRegsMode { kIgnore, kSave };
+enum class ArgvMode { kStack, kRegister };
 
 // This constant is used as an undefined value when passing source positions.
 constexpr int kNoSourcePosition = -1;
@@ -789,11 +798,14 @@ constexpr int kSpaceTagSize = 4;
 STATIC_ASSERT(FIRST_SPACE == 0);
 
 enum class AllocationType : uint8_t {
-  kYoung,    // Regular object allocated in NEW_SPACE or NEW_LO_SPACE
-  kOld,      // Regular object allocated in OLD_SPACE or LO_SPACE
-  kCode,     // Code object allocated in CODE_SPACE or CODE_LO_SPACE
-  kMap,      // Map object allocated in MAP_SPACE
-  kReadOnly  // Object allocated in RO_SPACE
+  kYoung,      // Regular object allocated in NEW_SPACE or NEW_LO_SPACE
+  kOld,        // Regular object allocated in OLD_SPACE or LO_SPACE
+  kCode,       // Code object allocated in CODE_SPACE or CODE_LO_SPACE
+  kMap,        // Map object allocated in MAP_SPACE
+  kReadOnly,   // Object allocated in RO_SPACE
+  kSharedOld,  // Regular object allocated in SHARED_OLD_SPACE or
+               // SHARED_LO_SPACE
+  kSharedMap,  // Map object in SHARED_MAP_SPACE
 };
 
 inline size_t hash_value(AllocationType kind) {
@@ -812,6 +824,10 @@ inline std::ostream& operator<<(std::ostream& os, AllocationType kind) {
       return os << "Map";
     case AllocationType::kReadOnly:
       return os << "ReadOnly";
+    case AllocationType::kSharedOld:
+      return os << "SharedOld";
+    case AllocationType::kSharedMap:
+      return os << "SharedMap";
   }
   UNREACHABLE();
 }
@@ -880,6 +896,8 @@ enum InlineCacheState {
   RECOMPUTE_HANDLER,
   // Multiple receiver types have been seen.
   POLYMORPHIC,
+  // Many DOM receiver types have been seen for the same accessor.
+  MEGADOM,
   // Many receiver types have been seen.
   MEGAMORPHIC,
   // A generic handler is installed and no extra typefeedback is recorded.
@@ -901,6 +919,8 @@ inline const char* InlineCacheState2String(InlineCacheState state) {
       return "POLYMORPHIC";
     case MEGAMORPHIC:
       return "MEGAMORPHIC";
+    case MEGADOM:
+      return "MEGADOM";
     case GENERIC:
       return "GENERIC";
   }
@@ -1602,6 +1622,7 @@ inline std::ostream& operator<<(std::ostream& os,
 }
 
 enum class SpeculationMode { kAllowSpeculation, kDisallowSpeculation };
+enum class CallFeedbackContent { kTarget, kReceiver };
 
 inline std::ostream& operator<<(std::ostream& os,
                                 SpeculationMode speculation_mode) {
@@ -1758,6 +1779,10 @@ class PtrComprCageBase {
 
   inline Address address() const;
 
+  bool operator==(const PtrComprCageBase& other) const {
+    return address_ == other.address_;
+  }
+
  private:
   Address address_;
 };
diff --git a/chromium/v8/src/common/message-template.h b/chromium/v8/src/common/message-template.h
index 5193a0bae3e..6d7116f73e5 100644
--- a/chromium/v8/src/common/message-template.h
+++ b/chromium/v8/src/common/message-template.h
@@ -330,6 +330,8 @@ namespace internal {
     "Expected letters optionally connected with underscores or hyphens for "   \
     "a location, got %")                                                       \
   T(InvalidArrayBufferLength, "Invalid array buffer length")                   \
+  T(InvalidArrayBufferMaxLength, "Invalid array buffer max length")            \
+  T(InvalidArrayBufferResizeLength, "%: Invalid length parameter")             \
   T(ArrayBufferAllocationFailed, "Array buffer allocation failed")             \
   T(Invalid, "Invalid % : %")                                                  \
   T(InvalidArrayLength, "Invalid array length")                                \
@@ -354,6 +356,7 @@ namespace internal {
   T(LetInLexicalBinding, "let is disallowed as a lexically bound name")        \
   T(LocaleMatcher, "Illegal value for localeMatcher:%")                        \
   T(NormalizationForm, "The normalization form should be one of %.")           \
+  T(OutOfMemory, "%: Out of memory")                                           \
   T(ParameterOfFunctionOutOfRange,                                             \
     "Paramenter % of function %() is % and out of range")                      \
   T(ZeroDigitNumericSeparator,                                                 \
@@ -564,7 +567,7 @@ namespace internal {
   T(WasmTrapRemByZero, "remainder by zero")                                    \
   T(WasmTrapFloatUnrepresentable, "float unrepresentable in integer range")    \
   T(WasmTrapTableOutOfBounds, "table index is out of bounds")                  \
-  T(WasmTrapFuncSigMismatch, "function signature mismatch")                    \
+  T(WasmTrapFuncSigMismatch, "null function or function signature mismatch")   \
   T(WasmTrapMultiReturnLengthMismatch, "multi-return length mismatch")         \
   T(WasmTrapJSTypeError, "type incompatibility when transforming from/to JS")  \
   T(WasmTrapDataSegmentDropped, "data segment has been dropped")               \
diff --git a/chromium/v8/src/common/ptr-compr-inl.h b/chromium/v8/src/common/ptr-compr-inl.h
index 66c22311b02..7a4d940891c 100644
--- a/chromium/v8/src/common/ptr-compr-inl.h
+++ b/chromium/v8/src/common/ptr-compr-inl.h
@@ -15,30 +15,10 @@ namespace internal {
 
 #ifdef V8_COMPRESS_POINTERS
 
-#if defined V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE
-
-PtrComprCageBase::PtrComprCageBase(const Isolate* isolate)
-    : address_(isolate->isolate_root()) {}
-PtrComprCageBase::PtrComprCageBase(const LocalIsolate* isolate)
-    : address_(isolate->isolate_root()) {}
-
-#elif defined V8_COMPRESS_POINTERS_IN_SHARED_CAGE
-
 PtrComprCageBase::PtrComprCageBase(const Isolate* isolate)
-    : address_(isolate->isolate_root()) {
-  UNIMPLEMENTED();
-}
+    : address_(isolate->cage_base()) {}
 PtrComprCageBase::PtrComprCageBase(const LocalIsolate* isolate)
-    : address_(isolate->isolate_root()) {
-  UNIMPLEMENTED();
-}
-
-#else
-
-#error "Pointer compression build configuration error"
-
-#endif  // V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE,
-        // V8_COMPRESS_POINTERS_IN_SHARED_CAGE
+    : address_(isolate->cage_base()) {}
 
 Address PtrComprCageBase::address() const {
   Address ret = address_;
diff --git a/chromium/v8/src/compiler-dispatcher/compiler-dispatcher.cc b/chromium/v8/src/compiler-dispatcher/compiler-dispatcher.cc
index a22c79e0ad9..2af0fd498c3 100644
--- a/chromium/v8/src/compiler-dispatcher/compiler-dispatcher.cc
+++ b/chromium/v8/src/compiler-dispatcher/compiler-dispatcher.cc
@@ -59,8 +59,7 @@ base::Optional<CompilerDispatcher::JobId> CompilerDispatcher::Enqueue(
     const FunctionLiteral* function_literal) {
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                "V8.CompilerDispatcherEnqueue");
-  RuntimeCallTimerScope runtimeTimer(
-      isolate_, RuntimeCallCounterId::kCompileEnqueueOnDispatcher);
+  RCS_SCOPE(isolate_, RuntimeCallCounterId::kCompileEnqueueOnDispatcher);
 
   if (!IsEnabled()) return base::nullopt;
 
@@ -129,8 +128,7 @@ void CompilerDispatcher::RegisterSharedFunctionInfo(
 void CompilerDispatcher::WaitForJobIfRunningOnBackground(Job* job) {
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                "V8.CompilerDispatcherWaitForBackgroundJob");
-  RuntimeCallTimerScope runtimeTimer(
-      isolate_, RuntimeCallCounterId::kCompileWaitForDispatcher);
+  RCS_SCOPE(isolate_, RuntimeCallCounterId::kCompileWaitForDispatcher);
 
   base::MutexGuard lock(&mutex_);
   if (running_background_jobs_.find(job) == running_background_jobs_.end()) {
@@ -149,8 +147,7 @@ void CompilerDispatcher::WaitForJobIfRunningOnBackground(Job* job) {
 bool CompilerDispatcher::FinishNow(Handle<SharedFunctionInfo> function) {
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                "V8.CompilerDispatcherFinishNow");
-  RuntimeCallTimerScope runtimeTimer(
-      isolate_, RuntimeCallCounterId::kCompileFinishNowOnDispatcher);
+  RCS_SCOPE(isolate_, RuntimeCallCounterId::kCompileFinishNowOnDispatcher);
   if (trace_compiler_dispatcher_) {
     PrintF("CompilerDispatcher: finishing ");
     function->ShortPrint();
diff --git a/chromium/v8/src/compiler-dispatcher/optimizing-compile-dispatcher.cc b/chromium/v8/src/compiler-dispatcher/optimizing-compile-dispatcher.cc
index 73292dd5ad6..c7727c951b9 100644
--- a/chromium/v8/src/compiler-dispatcher/optimizing-compile-dispatcher.cc
+++ b/chromium/v8/src/compiler-dispatcher/optimizing-compile-dispatcher.cc
@@ -57,16 +57,19 @@ class OptimizingCompileDispatcher::CompileTask : public CancelableTask {
  private:
   // v8::Task overrides.
   void RunInternal() override {
+#ifdef V8_RUNTIME_CALL_STATS
     WorkerThreadRuntimeCallStatsScope runtime_call_stats_scope(
         worker_thread_runtime_call_stats_);
     LocalIsolate local_isolate(isolate_, ThreadKind::kBackground,
                                runtime_call_stats_scope.Get());
+#else   // V8_RUNTIME_CALL_STATS
+    LocalIsolate local_isolate(isolate_, ThreadKind::kBackground);
+#endif  // V8_RUNTIME_CALL_STATS
     DCHECK(local_isolate.heap()->IsParked());
 
     {
-      RuntimeCallTimerScope runtimeTimer(
-          runtime_call_stats_scope.Get(),
-          RuntimeCallCounterId::kOptimizeBackgroundDispatcherJob);
+      RCS_SCOPE(runtime_call_stats_scope.Get(),
+                RuntimeCallCounterId::kOptimizeBackgroundDispatcherJob);
 
       TimerEventScope<TimerEventRecompileConcurrent> timer(isolate_);
       TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
@@ -78,7 +81,7 @@ class OptimizingCompileDispatcher::CompileTask : public CancelableTask {
       }
 
       dispatcher_->CompileNext(dispatcher_->NextInput(&local_isolate),
-                               runtime_call_stats_scope.Get(), &local_isolate);
+                               &local_isolate);
     }
     {
       base::MutexGuard lock_guard(&dispatcher_->ref_count_mutex_);
@@ -111,12 +114,12 @@ OptimizedCompilationJob* OptimizingCompileDispatcher::NextInput(
 }
 
 void OptimizingCompileDispatcher::CompileNext(OptimizedCompilationJob* job,
-                                              RuntimeCallStats* stats,
                                               LocalIsolate* local_isolate) {
   if (!job) return;
 
   // The function may have already been optimized by OSR.  Simply continue.
-  CompilationJob::Status status = job->ExecuteJob(stats, local_isolate);
+  CompilationJob::Status status =
+      job->ExecuteJob(local_isolate->runtime_call_stats(), local_isolate);
   USE(status);  // Prevent an unused-variable error.
 
   {
@@ -167,6 +170,7 @@ void OptimizingCompileDispatcher::FlushQueues(
 }
 
 void OptimizingCompileDispatcher::Flush(BlockingBehavior blocking_behavior) {
+  HandleScope handle_scope(isolate_);
   FlushQueues(blocking_behavior, true);
   if (FLAG_trace_concurrent_recompilation) {
     PrintF("  ** Flushed concurrent recompilation queues. (mode: %s)\n",
@@ -176,6 +180,7 @@ void OptimizingCompileDispatcher::Flush(BlockingBehavior blocking_behavior) {
 }
 
 void OptimizingCompileDispatcher::Stop() {
+  HandleScope handle_scope(isolate_);
   FlushQueues(BlockingBehavior::kBlock, false);
   // At this point the optimizing compiler thread's event loop has stopped.
   // There is no need for a mutex when reading input_queue_length_.
diff --git a/chromium/v8/src/compiler-dispatcher/optimizing-compile-dispatcher.h b/chromium/v8/src/compiler-dispatcher/optimizing-compile-dispatcher.h
index 37454c67e0d..4ae966192fa 100644
--- a/chromium/v8/src/compiler-dispatcher/optimizing-compile-dispatcher.h
+++ b/chromium/v8/src/compiler-dispatcher/optimizing-compile-dispatcher.h
@@ -64,8 +64,7 @@ class V8_EXPORT_PRIVATE OptimizingCompileDispatcher {
                    bool restore_function_code);
   void FlushInputQueue();
   void FlushOutputQueue(bool restore_function_code);
-  void CompileNext(OptimizedCompilationJob* job, RuntimeCallStats* stats,
-                   LocalIsolate* local_isolate);
+  void CompileNext(OptimizedCompilationJob* job, LocalIsolate* local_isolate);
   OptimizedCompilationJob* NextInput(LocalIsolate* local_isolate);
 
   inline int InputQueueIndex(int i) {
diff --git a/chromium/v8/src/compiler/OWNERS b/chromium/v8/src/compiler/OWNERS
index 5260502f32a..1626bc54876 100644
--- a/chromium/v8/src/compiler/OWNERS
+++ b/chromium/v8/src/compiler/OWNERS
@@ -11,6 +11,8 @@ per-file wasm-*=bbudge@chromium.org
 per-file wasm-*=clemensb@chromium.org
 per-file wasm-*=gdeepti@chromium.org
 per-file wasm-*=jkummerow@chromium.org
+per-file wasm-*=manoskouk@chromium.org
+per-file wasm-*=thibaudm@chromium.org
 
 per-file int64-lowering.*=ahaas@chromium.org
 
@@ -23,7 +25,3 @@ per-file opcodes.*=ahaas@chromium.org
 per-file opcodes.*=bbudge@chromium.org
 per-file opcodes.*=gdeepti@chromium.org
 per-file opcodes.*=zhin@chromium.org
-
-per-file simd-scalar-lowering.*=bbudge@chromium.org
-per-file simd-scalar-lowering.*=gdeepti@chromium.org
-per-file simd-scalar-lowering.*=zhin@chromium.org
diff --git a/chromium/v8/src/compiler/access-builder.cc b/chromium/v8/src/compiler/access-builder.cc
index 3cc4000d12e..675371df57a 100644
--- a/chromium/v8/src/compiler/access-builder.cc
+++ b/chromium/v8/src/compiler/access-builder.cc
@@ -31,11 +31,11 @@ FieldAccess AccessBuilder::ForExternalIntPtr() {
 }
 
 // static
-FieldAccess AccessBuilder::ForMap() {
+FieldAccess AccessBuilder::ForMap(WriteBarrierKind write_barrier) {
   FieldAccess access = {kTaggedBase,           HeapObject::kMapOffset,
                         MaybeHandle<Name>(),   MaybeHandle<Map>(),
-                        Type::OtherInternal(), MachineType::TaggedPointer(),
-                        kMapWriteBarrier};
+                        Type::OtherInternal(), MachineType::MapInHeader(),
+                        write_barrier};
   return access;
 }
 
@@ -105,12 +105,12 @@ FieldAccess AccessBuilder::ForJSObjectElements() {
 }
 
 // static
-FieldAccess AccessBuilder::ForJSObjectInObjectProperty(const MapRef& map,
-                                                       int index) {
+FieldAccess AccessBuilder::ForJSObjectInObjectProperty(
+    const MapRef& map, int index, MachineType machine_type) {
   int const offset = map.GetInObjectPropertyOffset(index);
   FieldAccess access = {kTaggedBase,         offset,
                         MaybeHandle<Name>(), MaybeHandle<Map>(),
-                        Type::NonInternal(), MachineType::AnyTagged(),
+                        Type::NonInternal(), machine_type,
                         kFullWriteBarrier};
   return access;
 }
@@ -760,7 +760,7 @@ FieldAccess AccessBuilder::ForExternalStringResourceData() {
       ConstFieldInfo::None(),
       false,
 #ifdef V8_HEAP_SANDBOX
-      kExternalStringResourceTag,
+      kExternalStringResourceDataTag,
 #endif
   };
   return access;
diff --git a/chromium/v8/src/compiler/access-builder.h b/chromium/v8/src/compiler/access-builder.h
index 08e11179ba7..fa68628cf80 100644
--- a/chromium/v8/src/compiler/access-builder.h
+++ b/chromium/v8/src/compiler/access-builder.h
@@ -31,7 +31,7 @@ class V8_EXPORT_PRIVATE AccessBuilder final
   // Access to heap object fields and elements (based on tagged pointer).
 
   // Provides access to HeapObject::map() field.
-  static FieldAccess ForMap();
+  static FieldAccess ForMap(WriteBarrierKind write_barrier = kMapWriteBarrier);
 
   // Provides access to HeapNumber::value() field.
   static FieldAccess ForHeapNumberValue();
@@ -58,7 +58,9 @@ class V8_EXPORT_PRIVATE AccessBuilder final
   static FieldAccess ForJSObjectElements();
 
   // Provides access to JSObject inobject property fields.
-  static FieldAccess ForJSObjectInObjectProperty(const MapRef& map, int index);
+  static FieldAccess ForJSObjectInObjectProperty(
+      const MapRef& map, int index,
+      MachineType machine_type = MachineType::AnyTagged());
   static FieldAccess ForJSObjectOffset(
       int offset, WriteBarrierKind write_barrier_kind = kFullWriteBarrier);
 
diff --git a/chromium/v8/src/compiler/access-info.cc b/chromium/v8/src/compiler/access-info.cc
index bc3f113eb79..0e3ccc19483 100644
--- a/chromium/v8/src/compiler/access-info.cc
+++ b/chromium/v8/src/compiler/access-info.cc
@@ -385,9 +385,10 @@ AccessInfoFactory::AccessInfoFactory(JSHeapBroker* broker,
 base::Optional<ElementAccessInfo> AccessInfoFactory::ComputeElementAccessInfo(
     Handle<Map> map, AccessMode access_mode) const {
   // Check if it is safe to inline element access for the {map}.
-  MapRef map_ref(broker(), map);
-  if (!CanInlineElementAccess(map_ref)) return base::nullopt;
-  ElementsKind const elements_kind = map_ref.elements_kind();
+  base::Optional<MapRef> map_ref = TryMakeRef(broker(), map);
+  if (!map_ref.has_value()) return {};
+  if (!CanInlineElementAccess(*map_ref)) return base::nullopt;
+  ElementsKind const elements_kind = map_ref->elements_kind();
   return ElementAccessInfo({{map}, zone()}, elements_kind, zone());
 }
 
@@ -427,8 +428,8 @@ PropertyAccessInfo AccessInfoFactory::ComputeDataFieldAccessInfo(
     Handle<Map> receiver_map, Handle<Map> map, MaybeHandle<JSObject> holder,
     InternalIndex descriptor, AccessMode access_mode) const {
   DCHECK(descriptor.is_found());
-  Handle<DescriptorArray> descriptors(map->instance_descriptors(isolate()),
-                                      isolate());
+  Handle<DescriptorArray> descriptors = broker()->CanonicalPersistentHandle(
+      map->instance_descriptors(kAcquireLoad));
   PropertyDetails const details = descriptors->GetDetails(descriptor);
   int index = descriptors->GetFieldIndex(descriptor);
   Representation details_representation = details.representation();
@@ -438,46 +439,55 @@ PropertyAccessInfo AccessInfoFactory::ComputeDataFieldAccessInfo(
     // fields for which the representation has not yet been
     // determined by the runtime. So we need to catch this case
     // here and fall back to use the regular IC logic instead.
-    return PropertyAccessInfo::Invalid(zone());
+    return Invalid();
   }
   FieldIndex field_index =
       FieldIndex::ForPropertyIndex(*map, index, details_representation);
   Type field_type = Type::NonInternal();
   MaybeHandle<Map> field_map;
-  MapRef map_ref(broker(), map);
+
+  base::Optional<MapRef> map_ref = TryMakeRef(broker(), map);
+  if (!map_ref.has_value()) return Invalid();
+
   ZoneVector<CompilationDependency const*> unrecorded_dependencies(zone());
-  map_ref.SerializeOwnDescriptor(descriptor);
+  if (!map_ref->TrySerializeOwnDescriptor(descriptor)) {
+    return Invalid();
+  }
   if (details_representation.IsSmi()) {
     field_type = Type::SignedSmall();
     unrecorded_dependencies.push_back(
-        dependencies()->FieldRepresentationDependencyOffTheRecord(map_ref,
+        dependencies()->FieldRepresentationDependencyOffTheRecord(*map_ref,
                                                                   descriptor));
   } else if (details_representation.IsDouble()) {
     field_type = type_cache_->kFloat64;
     unrecorded_dependencies.push_back(
-        dependencies()->FieldRepresentationDependencyOffTheRecord(map_ref,
+        dependencies()->FieldRepresentationDependencyOffTheRecord(*map_ref,
                                                                   descriptor));
   } else if (details_representation.IsHeapObject()) {
     // Extract the field type from the property details (make sure its
     // representation is TaggedPointer to reflect the heap object case).
-    Handle<FieldType> descriptors_field_type(
-        descriptors->GetFieldType(descriptor), isolate());
+    Handle<FieldType> descriptors_field_type =
+        broker()->CanonicalPersistentHandle(
+            descriptors->GetFieldType(descriptor));
     if (descriptors_field_type->IsNone()) {
       // Store is not safe if the field type was cleared.
       if (access_mode == AccessMode::kStore) {
-        return PropertyAccessInfo::Invalid(zone());
+        return Invalid();
       }
 
       // The field type was cleared by the GC, so we don't know anything
       // about the contents now.
     }
     unrecorded_dependencies.push_back(
-        dependencies()->FieldRepresentationDependencyOffTheRecord(map_ref,
+        dependencies()->FieldRepresentationDependencyOffTheRecord(*map_ref,
                                                                   descriptor));
     if (descriptors_field_type->IsClass()) {
       // Remember the field map, and try to infer a useful type.
-      Handle<Map> map(descriptors_field_type->AsClass(), isolate());
-      field_type = Type::For(MapRef(broker(), map));
+      Handle<Map> map = broker()->CanonicalPersistentHandle(
+          descriptors_field_type->AsClass());
+      base::Optional<MapRef> maybe_ref = TryMakeRef(broker(), map);
+      if (!maybe_ref.has_value()) return Invalid();
+      field_type = Type::For(*maybe_ref);
       field_map = MaybeHandle<Map>(map);
     }
   } else {
@@ -486,7 +496,7 @@ PropertyAccessInfo AccessInfoFactory::ComputeDataFieldAccessInfo(
   // TODO(turbofan): We may want to do this only depending on the use
   // of the access info.
   unrecorded_dependencies.push_back(
-      dependencies()->FieldTypeDependencyOffTheRecord(map_ref, descriptor));
+      dependencies()->FieldTypeDependencyOffTheRecord(*map_ref, descriptor));
 
   PropertyConstness constness;
   if (details.IsReadOnly() && !details.IsConfigurable()) {
@@ -497,11 +507,11 @@ PropertyAccessInfo AccessInfoFactory::ComputeDataFieldAccessInfo(
     // of turboprop.
     constness = PropertyConstness::kMutable;
   } else {
-    map_ref.SerializeOwnDescriptor(descriptor);
-    constness = dependencies()->DependOnFieldConstness(map_ref, descriptor);
+    constness = dependencies()->DependOnFieldConstness(*map_ref, descriptor);
   }
-  Handle<Map> field_owner_map(map->FindFieldOwner(isolate(), descriptor),
-                              isolate());
+  // TODO(v8:11670): Make FindFieldOwner and friends robust wrt concurrency.
+  Handle<Map> field_owner_map = broker()->CanonicalPersistentHandle(
+      map->FindFieldOwner(isolate(), descriptor));
   switch (constness) {
     case PropertyConstness::kMutable:
       return PropertyAccessInfo::DataField(
@@ -527,13 +537,14 @@ PropertyAccessInfo AccessorAccessInfoHelper(
     AccessMode access_mode, AccessorsObjectGetter get_accessors) {
   if (map->instance_type() == JS_MODULE_NAMESPACE_TYPE) {
     DCHECK(map->is_prototype_map());
-    Handle<PrototypeInfo> proto_info(PrototypeInfo::cast(map->prototype_info()),
-                                     isolate);
-    Handle<JSModuleNamespace> module_namespace(
-        JSModuleNamespace::cast(proto_info->module_namespace()), isolate);
-    Handle<Cell> cell(Cell::cast(module_namespace->module().exports().Lookup(
-                          isolate, name, Smi::ToInt(name->GetHash()))),
-                      isolate);
+    Handle<PrototypeInfo> proto_info = broker->CanonicalPersistentHandle(
+        PrototypeInfo::cast(map->prototype_info()));
+    Handle<JSModuleNamespace> module_namespace =
+        broker->CanonicalPersistentHandle(
+            JSModuleNamespace::cast(proto_info->module_namespace()));
+    Handle<Cell> cell = broker->CanonicalPersistentHandle(
+        Cell::cast(module_namespace->module().exports().Lookup(
+            isolate, name, Smi::ToInt(name->GetHash()))));
     if (cell->value().IsTheHole(isolate)) {
       // This module has not been fully initialized yet.
       return PropertyAccessInfo::Invalid(zone);
@@ -548,16 +559,20 @@ PropertyAccessInfo AccessorAccessInfoHelper(
     return PropertyAccessInfo::FastAccessorConstant(zone, receiver_map,
                                                     Handle<Object>(), holder);
   }
-  Handle<Object> accessors = get_accessors();
-  if (!accessors->IsAccessorPair()) {
+  Handle<Object> maybe_accessors = get_accessors();
+  if (!maybe_accessors->IsAccessorPair()) {
     return PropertyAccessInfo::Invalid(zone);
   }
-  Handle<Object> accessor(access_mode == AccessMode::kLoad
-                              ? Handle<AccessorPair>::cast(accessors)->getter()
-                              : Handle<AccessorPair>::cast(accessors)->setter(),
-                          isolate);
+  Handle<AccessorPair> accessors = Handle<AccessorPair>::cast(maybe_accessors);
+  Handle<Object> accessor = broker->CanonicalPersistentHandle(
+      access_mode == AccessMode::kLoad ? accessors->getter()
+                                       : accessors->setter());
+
+  ObjectData* data = broker->TryGetOrCreateData(accessor);
+  if (data == nullptr) return PropertyAccessInfo::Invalid(zone);
+
   if (!accessor->IsJSFunction()) {
-    CallOptimization optimization(isolate, accessor);
+    CallOptimization optimization(broker->local_isolate_or_isolate(), accessor);
     if (!optimization.is_simple_api_call() ||
         optimization.IsCrossContextLazyAccessorPair(
             *broker->target_native_context().object(), *map)) {
@@ -565,7 +580,9 @@ PropertyAccessInfo AccessorAccessInfoHelper(
     }
 
     CallOptimization::HolderLookup lookup;
-    holder = optimization.LookupHolderOfExpectedType(receiver_map, &lookup);
+    holder = broker->CanonicalPersistentHandle(
+        optimization.LookupHolderOfExpectedType(
+            broker->local_isolate_or_isolate(), receiver_map, &lookup));
     if (lookup == CallOptimization::kHolderNotFound) {
       return PropertyAccessInfo::Invalid(zone);
     }
@@ -574,9 +591,11 @@ PropertyAccessInfo AccessorAccessInfoHelper(
     DCHECK_IMPLIES(lookup == CallOptimization::kHolderFound, !holder.is_null());
   }
   if (access_mode == AccessMode::kLoad) {
-    Handle<Name> cached_property_name;
-    if (FunctionTemplateInfo::TryGetCachedPropertyName(isolate, accessor)
-            .ToHandle(&cached_property_name)) {
+    base::Optional<Name> maybe_cached_property_name =
+        FunctionTemplateInfo::TryGetCachedPropertyName(isolate, *accessor);
+    if (maybe_cached_property_name.has_value()) {
+      Handle<Name> cached_property_name =
+          broker->CanonicalPersistentHandle(maybe_cached_property_name.value());
       PropertyAccessInfo access_info = ai_factory->ComputePropertyAccessInfo(
           map, cached_property_name, access_mode);
       if (!access_info.IsInvalid()) return access_info;
@@ -598,12 +617,13 @@ PropertyAccessInfo AccessInfoFactory::ComputeAccessorDescriptorAccessInfo(
     MaybeHandle<JSObject> holder, InternalIndex descriptor,
     AccessMode access_mode) const {
   DCHECK(descriptor.is_found());
-  Handle<DescriptorArray> descriptors(
-      holder_map->instance_descriptors(kRelaxedLoad), isolate());
+  Handle<DescriptorArray> descriptors = broker()->CanonicalPersistentHandle(
+      holder_map->instance_descriptors(kRelaxedLoad));
   SLOW_DCHECK(descriptor == descriptors->Search(*name, *holder_map));
 
   auto get_accessors = [&]() {
-    return handle(descriptors->GetStrongValue(descriptor), isolate());
+    return broker()->CanonicalPersistentHandle(
+        descriptors->GetStrongValue(descriptor));
   };
   return AccessorAccessInfoHelper(isolate(), zone(), broker(), this,
                                   receiver_map, name, holder_map, holder,
@@ -620,7 +640,7 @@ PropertyAccessInfo AccessInfoFactory::ComputeDictionaryProtoAccessInfo(
 
   // We can only inline accesses to constant properties.
   if (details.constness() != PropertyConstness::kConst) {
-    return PropertyAccessInfo::Invalid(zone());
+    return Invalid();
   }
 
   if (details.kind() == PropertyKind::kData) {
@@ -631,7 +651,7 @@ PropertyAccessInfo AccessInfoFactory::ComputeDictionaryProtoAccessInfo(
   auto get_accessors = [&]() {
     return JSObject::DictionaryPropertyAt(holder, dictionary_index);
   };
-  Handle<Map> holder_map = handle(holder->map(), isolate());
+  Handle<Map> holder_map = broker()->CanonicalPersistentHandle(holder->map());
   return AccessorAccessInfoHelper(isolate(), zone(), broker(), this,
                                   receiver_map, name, holder_map, holder,
                                   access_mode, get_accessors);
@@ -699,17 +719,16 @@ PropertyAccessInfo AccessInfoFactory::ComputePropertyAccessInfo(
     Handle<Map> map, Handle<Name> name, AccessMode access_mode) const {
   CHECK(name->IsUniqueName());
 
-  base::SharedMutexGuardIf<base::kShared> mutex_guard(
-      isolate()->map_updater_access(), should_lock_mutex());
-  MapUpdaterMutexDepthScope mumd_scope(this);
+  JSHeapBroker::MapUpdaterGuardIfNeeded mumd_scope(
+      broker(), isolate()->map_updater_access());
 
   if (access_mode == AccessMode::kHas && !map->IsJSReceiverMap()) {
-    return PropertyAccessInfo::Invalid(zone());
+    return Invalid();
   }
 
   // Check if it is safe to inline property access for the {map}.
   if (!CanInlinePropertyAccess(map, access_mode)) {
-    return PropertyAccessInfo::Invalid(zone());
+    return Invalid();
   }
 
   // We support fast inline cases for certain JSObject getters.
@@ -729,7 +748,7 @@ PropertyAccessInfo AccessInfoFactory::ComputePropertyAccessInfo(
     PropertyDetails details = PropertyDetails::Empty();
     InternalIndex index = InternalIndex::NotFound();
     if (!TryLoadPropertyDetails(map, holder, name, &index, &details)) {
-      return PropertyAccessInfo::Invalid(zone());
+      return Invalid();
     }
 
     if (index.is_found()) {
@@ -739,7 +758,7 @@ PropertyAccessInfo AccessInfoFactory::ComputePropertyAccessInfo(
 
         // Don't bother optimizing stores to read-only properties.
         if (details.IsReadOnly()) {
-          return PropertyAccessInfo::Invalid(zone());
+          return Invalid();
         }
         if (details.kind() == kData && !holder.is_null()) {
           // This is a store to a property not found on the receiver but on a
@@ -758,7 +777,7 @@ PropertyAccessInfo AccessInfoFactory::ComputePropertyAccessInfo(
           // reaching a dictionary mode prototype holding the property . Due to
           // this only being an intermediate state, we don't stupport these kind
           // of heterogenous prototype chains.
-          return PropertyAccessInfo::Invalid(zone());
+          return Invalid();
         }
 
         // TryLoadPropertyDetails only succeeds if we know the holder.
@@ -781,7 +800,7 @@ PropertyAccessInfo AccessInfoFactory::ComputePropertyAccessInfo(
         // due to the complications of checking dictionary mode prototypes for
         // modification, we don't attempt to support dictionary mode prototypes
         // occuring before a fast mode holder on the chain.
-        return PropertyAccessInfo::Invalid(zone());
+        return Invalid();
       }
       if (details.location() == kField) {
         if (details.kind() == kData) {
@@ -790,7 +809,7 @@ PropertyAccessInfo AccessInfoFactory::ComputePropertyAccessInfo(
         } else {
           DCHECK_EQ(kAccessor, details.kind());
           // TODO(turbofan): Add support for general accessors?
-          return PropertyAccessInfo::Invalid(zone());
+          return Invalid();
         }
       } else {
         DCHECK_EQ(kDescriptor, details.location());
@@ -806,9 +825,17 @@ PropertyAccessInfo AccessInfoFactory::ComputePropertyAccessInfo(
 
     // Don't search on the prototype chain for special indices in case of
     // integer indexed exotic objects (see ES6 section 9.4.5).
-    if (map->IsJSTypedArrayMap() && name->IsString() &&
-        IsSpecialIndex(String::cast(*name))) {
-      return PropertyAccessInfo::Invalid(zone());
+    if (map->IsJSTypedArrayMap() && name->IsString()) {
+      if (broker()->IsMainThread()) {
+        if (IsSpecialIndex(String::cast(*name))) {
+          return Invalid();
+        }
+      } else {
+        // TODO(jgruber): We are being conservative here since we can't access
+        // string contents from background threads. Should that become possible
+        // in the future, remove this bailout.
+        return Invalid();
+      }
     }
 
     // Don't search on the prototype when storing in literals.
@@ -818,7 +845,7 @@ PropertyAccessInfo AccessInfoFactory::ComputePropertyAccessInfo(
 
     // Don't lookup private symbols on the prototype chain.
     if (name->IsPrivate()) {
-      return PropertyAccessInfo::Invalid(zone());
+      return Invalid();
     }
 
     if (V8_DICT_PROPERTY_CONST_TRACKING_BOOL && !holder.is_null()) {
@@ -833,21 +860,26 @@ PropertyAccessInfo AccessInfoFactory::ComputePropertyAccessInfo(
     }
 
     // Walk up the prototype chain.
-    MapRef(broker(), map).SerializePrototype();
+    base::Optional<MapRef> map_ref = TryMakeRef(broker(), map);
+    if (!map_ref.has_value()) return Invalid();
+    if (!map_ref->TrySerializePrototype()) return Invalid();
+
     // Acquire synchronously the map's prototype's map to guarantee that every
     // time we use it, we use the same Map.
-    Handle<Map> map_prototype_map(map->prototype().synchronized_map(),
-                                  isolate());
+    Handle<Map> map_prototype_map =
+        broker()->CanonicalPersistentHandle(map->prototype().map(kAcquireLoad));
     if (!map_prototype_map->IsJSObjectMap()) {
       // Perform the implicit ToObject for primitives here.
       // Implemented according to ES6 section 7.3.2 GetV (V, P).
       Handle<JSFunction> constructor;
-      if (Map::GetConstructorFunction(
-              map, broker()->target_native_context().object())
-              .ToHandle(&constructor)) {
-        map = handle(constructor->initial_map(), isolate());
-        map_prototype_map =
-            handle(map->prototype().synchronized_map(), isolate());
+      base::Optional<JSFunction> maybe_constructor =
+          Map::GetConstructorFunction(
+              *map, *broker()->target_native_context().object());
+      if (maybe_constructor.has_value()) {
+        map = broker()->CanonicalPersistentHandle(
+            maybe_constructor->initial_map());
+        map_prototype_map = broker()->CanonicalPersistentHandle(
+            map->prototype().map(kAcquireLoad));
         DCHECK(map_prototype_map->IsJSObjectMap());
       } else if (map->prototype().IsNull()) {
         if (dictionary_prototype_on_chain) {
@@ -856,7 +888,7 @@ PropertyAccessInfo AccessInfoFactory::ComputePropertyAccessInfo(
           // with dictionary mode prototypes on the chain, either. This is again
           // just due to how we currently deal with dependencies for dictionary
           // properties during finalization.
-          return PropertyAccessInfo::Invalid(zone());
+          return Invalid();
         }
 
         // Store to property not found on the receiver or any prototype, we need
@@ -870,16 +902,17 @@ PropertyAccessInfo AccessInfoFactory::ComputePropertyAccessInfo(
         // Implemented according to ES6 section 9.1.8 [[Get]] (P, Receiver)
         return PropertyAccessInfo::NotFound(zone(), receiver_map, holder);
       } else {
-        return PropertyAccessInfo::Invalid(zone());
+        return Invalid();
       }
     }
 
-    holder = handle(JSObject::cast(map->prototype()), isolate());
+    holder =
+        broker()->CanonicalPersistentHandle(JSObject::cast(map->prototype()));
     map = map_prototype_map;
     CHECK(!map->is_deprecated());
 
     if (!CanInlinePropertyAccess(map, access_mode)) {
-      return PropertyAccessInfo::Invalid(zone());
+      return Invalid();
     }
 
     // Successful lookup on prototype chain needs to guarantee that all the
@@ -901,7 +934,7 @@ PropertyAccessInfo AccessInfoFactory::FinalizePropertyAccessInfosAsOne(
       return result;
     }
   }
-  return PropertyAccessInfo::Invalid(zone());
+  return Invalid();
 }
 
 void AccessInfoFactory::ComputePropertyAccessInfos(
@@ -982,23 +1015,26 @@ base::Optional<ElementAccessInfo> AccessInfoFactory::ConsolidateElementLoad(
   if (feedback.transition_groups().empty()) return base::nullopt;
 
   DCHECK(!feedback.transition_groups().front().empty());
-  MapRef first_map(broker(), feedback.transition_groups().front().front());
-  InstanceType instance_type = first_map.instance_type();
-  ElementsKind elements_kind = first_map.elements_kind();
+  Handle<Map> first_map = feedback.transition_groups().front().front();
+  base::Optional<MapRef> first_map_ref = TryMakeRef(broker(), first_map);
+  if (!first_map_ref.has_value()) return {};
+  InstanceType instance_type = first_map_ref->instance_type();
+  ElementsKind elements_kind = first_map_ref->elements_kind();
 
   ZoneVector<Handle<Map>> maps(zone());
   for (auto const& group : feedback.transition_groups()) {
     for (Handle<Map> map_handle : group) {
-      MapRef map(broker(), map_handle);
-      if (map.instance_type() != instance_type ||
-          !CanInlineElementAccess(map)) {
+      base::Optional<MapRef> map = TryMakeRef(broker(), map_handle);
+      if (!map.has_value()) return {};
+      if (map->instance_type() != instance_type ||
+          !CanInlineElementAccess(*map)) {
         return base::nullopt;
       }
-      if (!GeneralizeElementsKind(elements_kind, map.elements_kind())
+      if (!GeneralizeElementsKind(elements_kind, map->elements_kind())
                .To(&elements_kind)) {
         return base::nullopt;
       }
-      maps.push_back(map.object());
+      maps.push_back(map->object());
     }
   }
 
@@ -1012,7 +1048,7 @@ PropertyAccessInfo AccessInfoFactory::LookupSpecialFieldAccessor(
     if (Name::Equals(isolate(), name, isolate()->factory()->length_string())) {
       return PropertyAccessInfo::StringLength(zone(), map);
     }
-    return PropertyAccessInfo::Invalid(zone());
+    return Invalid();
   }
   // Check for special JSObject field accessors.
   FieldIndex field_index;
@@ -1041,7 +1077,7 @@ PropertyAccessInfo AccessInfoFactory::LookupSpecialFieldAccessor(
     return PropertyAccessInfo::DataField(zone(), map, {{}, zone()}, field_index,
                                          field_representation, field_type, map);
   }
-  return PropertyAccessInfo::Invalid(zone());
+  return Invalid();
 }
 
 PropertyAccessInfo AccessInfoFactory::LookupTransition(
@@ -1051,21 +1087,21 @@ PropertyAccessInfo AccessInfoFactory::LookupTransition(
       TransitionsAccessor(isolate(), map, broker()->is_concurrent_inlining())
           .SearchTransition(*name, kData, NONE);
   if (transition.is_null()) {
-    return PropertyAccessInfo::Invalid(zone());
+    return Invalid();
   }
 
-  Handle<Map> transition_map(transition, isolate());
+  Handle<Map> transition_map = broker()->CanonicalPersistentHandle(transition);
   InternalIndex const number = transition_map->LastAdded();
-  Handle<DescriptorArray> descriptors(
-      transition_map->instance_descriptors(kAcquireLoad), isolate());
+  Handle<DescriptorArray> descriptors = broker()->CanonicalPersistentHandle(
+      transition_map->instance_descriptors(kAcquireLoad));
   PropertyDetails const details = descriptors->GetDetails(number);
   // Don't bother optimizing stores to read-only properties.
   if (details.IsReadOnly()) {
-    return PropertyAccessInfo::Invalid(zone());
+    return Invalid();
   }
   // TODO(bmeurer): Handle transition to data constant?
   if (details.location() != kField) {
-    return PropertyAccessInfo::Invalid(zone());
+    return Invalid();
   }
   int const index = details.field_index();
   Representation details_representation = details.representation();
@@ -1073,51 +1109,63 @@ PropertyAccessInfo AccessInfoFactory::LookupTransition(
                                                         details_representation);
   Type field_type = Type::NonInternal();
   MaybeHandle<Map> field_map;
-  MapRef transition_map_ref(broker(), transition_map);
+
+  base::Optional<MapRef> transition_map_ref =
+      TryMakeRef(broker(), transition_map);
+  if (!transition_map_ref.has_value()) return Invalid();
+
   ZoneVector<CompilationDependency const*> unrecorded_dependencies(zone());
   if (details_representation.IsSmi()) {
     field_type = Type::SignedSmall();
-    transition_map_ref.SerializeOwnDescriptor(number);
+    if (!transition_map_ref->TrySerializeOwnDescriptor(number)) {
+      return Invalid();
+    }
     unrecorded_dependencies.push_back(
         dependencies()->FieldRepresentationDependencyOffTheRecord(
-            transition_map_ref, number));
+            *transition_map_ref, number));
   } else if (details_representation.IsDouble()) {
     field_type = type_cache_->kFloat64;
-    transition_map_ref.SerializeOwnDescriptor(number);
+    if (!transition_map_ref->TrySerializeOwnDescriptor(number)) {
+      return Invalid();
+    }
     unrecorded_dependencies.push_back(
         dependencies()->FieldRepresentationDependencyOffTheRecord(
-            transition_map_ref, number));
+            *transition_map_ref, number));
   } else if (details_representation.IsHeapObject()) {
     // Extract the field type from the property details (make sure its
     // representation is TaggedPointer to reflect the heap object case).
-    Handle<FieldType> descriptors_field_type(descriptors->GetFieldType(number),
-                                             isolate());
+    Handle<FieldType> descriptors_field_type =
+        broker()->CanonicalPersistentHandle(descriptors->GetFieldType(number));
     if (descriptors_field_type->IsNone()) {
       // Store is not safe if the field type was cleared.
-      return PropertyAccessInfo::Invalid(zone());
+      return Invalid();
+    }
+    if (!transition_map_ref->TrySerializeOwnDescriptor(number)) {
+      return Invalid();
     }
-    transition_map_ref.SerializeOwnDescriptor(number);
     unrecorded_dependencies.push_back(
         dependencies()->FieldRepresentationDependencyOffTheRecord(
-            transition_map_ref, number));
+            *transition_map_ref, number));
     if (descriptors_field_type->IsClass()) {
       unrecorded_dependencies.push_back(
-          dependencies()->FieldTypeDependencyOffTheRecord(transition_map_ref,
+          dependencies()->FieldTypeDependencyOffTheRecord(*transition_map_ref,
                                                           number));
       // Remember the field map, and try to infer a useful type.
-      Handle<Map> map(descriptors_field_type->AsClass(), isolate());
-      field_type = Type::For(MapRef(broker(), map));
-      field_map = MaybeHandle<Map>(map);
+      Handle<Map> map = broker()->CanonicalPersistentHandle(
+          descriptors_field_type->AsClass());
+      base::Optional<MapRef> map_ref = TryMakeRef(broker(), map);
+      if (!map_ref.has_value()) return Invalid();
+      field_type = Type::For(*map_ref);
+      field_map = map;
     }
   }
   unrecorded_dependencies.push_back(
-      dependencies()->TransitionDependencyOffTheRecord(
-          MapRef(broker(), transition_map)));
-  transition_map_ref.SerializeBackPointer();  // For BuildPropertyStore.
+      dependencies()->TransitionDependencyOffTheRecord(*transition_map_ref));
+  transition_map_ref->SerializeBackPointer();  // For BuildPropertyStore.
   // Transitioning stores *may* store to const fields. The resulting
   // DataConstant access infos can be distinguished from later, i.e. redundant,
   // stores to the same constant field by the presence of a transition map.
-  switch (dependencies()->DependOnFieldConstness(transition_map_ref, number)) {
+  switch (dependencies()->DependOnFieldConstness(*transition_map_ref, number)) {
     case PropertyConstness::kMutable:
       return PropertyAccessInfo::DataField(
           zone(), map, std::move(unrecorded_dependencies), field_index,
diff --git a/chromium/v8/src/compiler/access-info.h b/chromium/v8/src/compiler/access-info.h
index b430dacd3ae..93215ea0a02 100644
--- a/chromium/v8/src/compiler/access-info.h
+++ b/chromium/v8/src/compiler/access-info.h
@@ -305,6 +305,10 @@ class AccessInfoFactory final {
       MaybeHandle<JSObject> holder, InternalIndex descriptor,
       AccessMode access_mode) const;
 
+  PropertyAccessInfo Invalid() const {
+    return PropertyAccessInfo::Invalid(zone());
+  }
+
   void MergePropertyAccessInfos(ZoneVector<PropertyAccessInfo> infos,
                                 AccessMode access_mode,
                                 ZoneVector<PropertyAccessInfo>* result) const;
@@ -313,28 +317,6 @@ class AccessInfoFactory final {
                               Handle<Name> name, InternalIndex* index_out,
                               PropertyDetails* details_out) const;
 
-  bool should_lock_mutex() const { return map_updater_mutex_depth_ == 0; }
-
-  class MapUpdaterMutexDepthScope final {
-   public:
-    explicit MapUpdaterMutexDepthScope(const AccessInfoFactory* ptr)
-        : ptr_(ptr),
-          initial_map_updater_mutex_depth_(ptr->map_updater_mutex_depth_) {
-      ptr_->map_updater_mutex_depth_++;
-    }
-
-    ~MapUpdaterMutexDepthScope() {
-      ptr_->map_updater_mutex_depth_--;
-      DCHECK_EQ(initial_map_updater_mutex_depth_,
-                ptr_->map_updater_mutex_depth_);
-      USE(initial_map_updater_mutex_depth_);
-    }
-
-   private:
-    const AccessInfoFactory* const ptr_;
-    const int initial_map_updater_mutex_depth_;
-  };
-
   CompilationDependencies* dependencies() const { return dependencies_; }
   JSHeapBroker* broker() const { return broker_; }
   Isolate* isolate() const;
@@ -345,12 +327,6 @@ class AccessInfoFactory final {
   TypeCache const* const type_cache_;
   Zone* const zone_;
 
-  // ComputePropertyAccessInfo can be called recursively, thus we need to
-  // emulate a recursive mutex. This field holds the locking depth, i.e. how
-  // many times the mutex has been recursively locked. Only the outermost
-  // locker actually locks underneath.
-  mutable int map_updater_mutex_depth_ = 0;
-
   // TODO(nicohartmann@): Move to public
   AccessInfoFactory(const AccessInfoFactory&) = delete;
   AccessInfoFactory& operator=(const AccessInfoFactory&) = delete;
diff --git a/chromium/v8/src/compiler/add-type-assertions-reducer.cc b/chromium/v8/src/compiler/add-type-assertions-reducer.cc
index 59d2fe68203..d555d518d2c 100644
--- a/chromium/v8/src/compiler/add-type-assertions-reducer.cc
+++ b/chromium/v8/src/compiler/add-type-assertions-reducer.cc
@@ -27,9 +27,7 @@ Reduction AddTypeAssertionsReducer::Reduce(Node* node) {
   visited_.Set(node, true);
 
   Type type = NodeProperties::GetType(node);
-  if (!type.IsRange()) {
-    return NoChange();
-  }
+  if (!type.CanBeAsserted()) return NoChange();
 
   Node* assertion = graph()->NewNode(simplified()->AssertType(type), node);
   NodeProperties::SetType(assertion, type);
diff --git a/chromium/v8/src/compiler/backend/arm/code-generator-arm.cc b/chromium/v8/src/compiler/backend/arm/code-generator-arm.cc
index dba31fe0bc3..35d8cb73618 100644
--- a/chromium/v8/src/compiler/backend/arm/code-generator-arm.cc
+++ b/chromium/v8/src/compiler/backend/arm/code-generator-arm.cc
@@ -194,16 +194,14 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
   }
 
   void Generate() final {
-    if (mode_ > RecordWriteMode::kValueIsPointer) {
-      __ JumpIfSmi(value_, exit());
-    }
     __ CheckPageFlag(value_, MemoryChunk::kPointersToHereAreInterestingMask, eq,
                      exit());
     RememberedSetAction const remembered_set_action =
-        mode_ > RecordWriteMode::kValueIsMap ? EMIT_REMEMBERED_SET
-                                             : OMIT_REMEMBERED_SET;
-    SaveFPRegsMode const save_fp_mode =
-        frame()->DidAllocateDoubleRegisters() ? kSaveFPRegs : kDontSaveFPRegs;
+        mode_ > RecordWriteMode::kValueIsMap ? RememberedSetAction::kEmit
+                                             : RememberedSetAction::kOmit;
+    SaveFPRegsMode const save_fp_mode = frame()->DidAllocateDoubleRegisters()
+                                            ? SaveFPRegsMode::kSave
+                                            : SaveFPRegsMode::kIgnore;
     if (must_save_lr_) {
       // We need to save and restore lr if the frame was elided.
       __ Push(lr);
@@ -828,7 +826,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchSaveCallerRegisters: {
       fp_mode_ =
           static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode()));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // kReturnRegister0 should have been saved before entering the stub.
       int bytes = __ PushCallerSaved(fp_mode_, kReturnRegister0);
       DCHECK(IsAligned(bytes, kSystemPointerSize));
@@ -841,7 +840,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchRestoreCallerRegisters: {
       DCHECK(fp_mode_ ==
              static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode())));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // Don't overwrite the returned value.
       int bytes = __ PopCallerSaved(fp_mode_, kReturnRegister0);
       frame_access_state()->IncreaseSPDelta(-(bytes / kSystemPointerSize));
@@ -999,6 +999,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       auto ool = zone()->New<OutOfLineRecordWrite>(
           this, object, offset, value, mode, DetermineStubCallMode(),
           &unwinding_info_writer_);
+      if (mode > RecordWriteMode::kValueIsPointer) {
+        __ JumpIfSmi(value, ool->exit());
+      }
       __ CheckPageFlag(object, MemoryChunk::kPointersFromHereAreInterestingMask,
                        ne, ool->entry());
       __ bind(ool->exit());
@@ -3576,7 +3579,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
 #undef ASSEMBLE_SIMD_SHIFT_RIGHT
   }
   return kSuccess;
-}  // NOLINT(readability/fn_size)
+}
 
 // Assembles branches after an instruction.
 void CodeGenerator::AssembleArchBranch(Instruction* instr, BranchInfo* branch) {
@@ -3793,7 +3796,7 @@ void CodeGenerator::AssembleConstructFrame() {
     // frame is still on the stack. Optimized code uses OSR values directly from
     // the unoptimized frame. Thus, all that needs to be done is to allocate the
     // remaining stack slots.
-    if (FLAG_code_comments) __ RecordComment("-- OSR entrypoint --");
+    __ RecordComment("-- OSR entrypoint --");
     osr_pc_offset_ = __ pc_offset();
     required_slots -= osr_helper()->UnoptimizedFrameSlots();
     ResetSpeculationPoison();
@@ -3906,7 +3909,7 @@ void CodeGenerator::AssembleReturn(InstructionOperand* additional_pop_count) {
   if (parameter_slots != 0) {
     if (additional_pop_count->IsImmediate()) {
       DCHECK_EQ(g.ToConstant(additional_pop_count).ToInt32(), 0);
-    } else if (__ emit_debug_code()) {
+    } else if (FLAG_debug_code) {
       __ cmp(g.ToRegister(additional_pop_count), Operand(0));
       __ Assert(eq, AbortReason::kUnexpectedAdditionalPopValue);
     }
diff --git a/chromium/v8/src/compiler/backend/arm/instruction-selector-arm.cc b/chromium/v8/src/compiler/backend/arm/instruction-selector-arm.cc
index d28ada322d4..bb17d45253d 100644
--- a/chromium/v8/src/compiler/backend/arm/instruction-selector-arm.cc
+++ b/chromium/v8/src/compiler/backend/arm/instruction-selector-arm.cc
@@ -626,6 +626,7 @@ void InstructionSelector::VisitLoad(Node* node) {
     case MachineRepresentation::kCompressedPointer:  // Fall through.
     case MachineRepresentation::kCompressed:         // Fall through.
     case MachineRepresentation::kWord64:             // Fall through.
+    case MachineRepresentation::kMapWord:            // Fall through.
     case MachineRepresentation::kNone:
       UNREACHABLE();
   }
@@ -709,6 +710,7 @@ void InstructionSelector::VisitStore(Node* node) {
       case MachineRepresentation::kCompressedPointer:  // Fall through.
       case MachineRepresentation::kCompressed:         // Fall through.
       case MachineRepresentation::kWord64:             // Fall through.
+      case MachineRepresentation::kMapWord:            // Fall through.
       case MachineRepresentation::kNone:
         UNREACHABLE();
     }
@@ -3170,6 +3172,12 @@ void InstructionSelector::VisitF64x2PromoteLowF32x4(Node* node) {
        g.UseFixed(node->InputAt(0), q0));
 }
 
+void InstructionSelector::AddOutputToSelectContinuation(OperandGenerator* g,
+                                                        int first_input_index,
+                                                        Node* node) {
+  UNREACHABLE();
+}
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
diff --git a/chromium/v8/src/compiler/backend/arm64/code-generator-arm64.cc b/chromium/v8/src/compiler/backend/arm64/code-generator-arm64.cc
index 91b8f1f04b1..a10c9f98b22 100644
--- a/chromium/v8/src/compiler/backend/arm64/code-generator-arm64.cc
+++ b/chromium/v8/src/compiler/backend/arm64/code-generator-arm64.cc
@@ -104,7 +104,7 @@ class Arm64OperandConverter final : public InstructionOperandConverter {
 
   Register OutputRegister64() { return OutputRegister(); }
 
-  Register OutputRegister32() { return ToRegister(instr_->Output()).W(); }
+  Register OutputRegister32() { return OutputRegister().W(); }
 
   Register TempRegister32(size_t index) {
     return ToRegister(instr_->TempAt(index)).W();
@@ -282,19 +282,17 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
   }
 
   void Generate() final {
-    if (mode_ > RecordWriteMode::kValueIsPointer) {
-      __ JumpIfSmi(value_, exit());
-    }
     if (COMPRESS_POINTERS_BOOL) {
       __ DecompressTaggedPointer(value_, value_);
     }
     __ CheckPageFlag(value_, MemoryChunk::kPointersToHereAreInterestingMask, ne,
                      exit());
     RememberedSetAction const remembered_set_action =
-        mode_ > RecordWriteMode::kValueIsMap ? EMIT_REMEMBERED_SET
-                                             : OMIT_REMEMBERED_SET;
-    SaveFPRegsMode const save_fp_mode =
-        frame()->DidAllocateDoubleRegisters() ? kSaveFPRegs : kDontSaveFPRegs;
+        mode_ > RecordWriteMode::kValueIsMap ? RememberedSetAction::kEmit
+                                             : RememberedSetAction::kOmit;
+    SaveFPRegsMode const save_fp_mode = frame()->DidAllocateDoubleRegisters()
+                                            ? SaveFPRegsMode::kSave
+                                            : SaveFPRegsMode::kIgnore;
     if (must_save_lr_) {
       // We need to save and restore lr if the frame was elided.
       __ Push<TurboAssembler::kSignLR>(lr, padreg);
@@ -859,7 +857,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchSaveCallerRegisters: {
       fp_mode_ =
           static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode()));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // kReturnRegister0 should have been saved before entering the stub.
       int bytes = __ PushCallerSaved(fp_mode_, kReturnRegister0);
       DCHECK(IsAligned(bytes, kSystemPointerSize));
@@ -872,7 +871,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchRestoreCallerRegisters: {
       DCHECK(fp_mode_ ==
              static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode())));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // Don't overwrite the returned value.
       int bytes = __ PopCallerSaved(fp_mode_, kReturnRegister0);
       frame_access_state()->IncreaseSPDelta(-(bytes / kSystemPointerSize));
@@ -1026,6 +1026,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
           this, object, offset, value, mode, DetermineStubCallMode(),
           &unwinding_info_writer_);
       __ StoreTaggedField(value, MemOperand(object, offset));
+      if (mode > RecordWriteMode::kValueIsPointer) {
+        __ JumpIfSmi(value, ool->exit());
+      }
       __ CheckPageFlag(object, MemoryChunk::kPointersFromHereAreInterestingMask,
                        eq, ool->entry());
       __ Bind(ool->exit());
@@ -1802,6 +1805,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ Ldrsb(i.OutputRegister(), i.MemoryOperand());
       EmitWordLoadPoisoningIfNeeded(this, opcode, instr, i);
       break;
+    case kArm64LdrsbW:
+      EmitOOLTrapIfNeeded(zone(), this, opcode, instr, __ pc_offset());
+      __ Ldrsb(i.OutputRegister32(), i.MemoryOperand());
+      break;
     case kArm64Strb:
       EmitOOLTrapIfNeeded(zone(), this, opcode, instr, __ pc_offset());
       __ Strb(i.InputOrZeroRegister64(0), i.MemoryOperand(1));
@@ -1816,6 +1823,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ Ldrsh(i.OutputRegister(), i.MemoryOperand());
       EmitWordLoadPoisoningIfNeeded(this, opcode, instr, i);
       break;
+    case kArm64LdrshW:
+      EmitOOLTrapIfNeeded(zone(), this, opcode, instr, __ pc_offset());
+      __ Ldrsh(i.OutputRegister32(), i.MemoryOperand());
+      break;
     case kArm64Strh:
       EmitOOLTrapIfNeeded(zone(), this, opcode, instr, __ pc_offset());
       __ Strh(i.InputOrZeroRegister64(0), i.MemoryOperand(1));
@@ -2862,7 +2873,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       SIMD_REDUCE_OP_CASE(kArm64I8x16AllTrue, Uminv, kFormatB, 16B);
   }
   return kSuccess;
-}  // NOLINT(readability/fn_size)
+}
 
 #undef SIMD_UNOP_CASE
 #undef SIMD_BINOP_CASE
@@ -3106,7 +3117,7 @@ void CodeGenerator::AssembleConstructFrame() {
       // unoptimized frame is still on the stack. Optimized code uses OSR values
       // directly from the unoptimized frame. Thus, all that needs to be done is
       // to allocate the remaining stack slots.
-      if (FLAG_code_comments) __ RecordComment("-- OSR entrypoint --");
+      __ RecordComment("-- OSR entrypoint --");
       osr_pc_offset_ = __ pc_offset();
       __ CodeEntry();
       size_t unoptimized_frame_slots = osr_helper()->UnoptimizedFrameSlots();
@@ -3280,7 +3291,7 @@ void CodeGenerator::AssembleReturn(InstructionOperand* additional_pop_count) {
   if (parameter_slots != 0) {
     if (additional_pop_count->IsImmediate()) {
       DCHECK_EQ(g.ToConstant(additional_pop_count).ToInt32(), 0);
-    } else if (__ emit_debug_code()) {
+    } else if (FLAG_debug_code) {
       __ cmp(g.ToRegister(additional_pop_count), Operand(0));
       __ Assert(eq, AbortReason::kUnexpectedAdditionalPopValue);
     }
diff --git a/chromium/v8/src/compiler/backend/arm64/instruction-codes-arm64.h b/chromium/v8/src/compiler/backend/arm64/instruction-codes-arm64.h
index 7c376168425..6612269548d 100644
--- a/chromium/v8/src/compiler/backend/arm64/instruction-codes-arm64.h
+++ b/chromium/v8/src/compiler/backend/arm64/instruction-codes-arm64.h
@@ -160,9 +160,11 @@ namespace compiler {
   V(Arm64StrQ)                              \
   V(Arm64Ldrb)                              \
   V(Arm64Ldrsb)                             \
+  V(Arm64LdrsbW)                            \
   V(Arm64Strb)                              \
   V(Arm64Ldrh)                              \
   V(Arm64Ldrsh)                             \
+  V(Arm64LdrshW)                            \
   V(Arm64Strh)                              \
   V(Arm64Ldrsw)                             \
   V(Arm64LdrW)                              \
diff --git a/chromium/v8/src/compiler/backend/arm64/instruction-scheduler-arm64.cc b/chromium/v8/src/compiler/backend/arm64/instruction-scheduler-arm64.cc
index 520db21dde0..293712858f5 100644
--- a/chromium/v8/src/compiler/backend/arm64/instruction-scheduler-arm64.cc
+++ b/chromium/v8/src/compiler/backend/arm64/instruction-scheduler-arm64.cc
@@ -361,8 +361,10 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kArm64LdrQ:
     case kArm64Ldrb:
     case kArm64Ldrsb:
+    case kArm64LdrsbW:
     case kArm64Ldrh:
     case kArm64Ldrsh:
+    case kArm64LdrshW:
     case kArm64Ldrsw:
     case kArm64LdrW:
     case kArm64Ldr:
diff --git a/chromium/v8/src/compiler/backend/arm64/instruction-selector-arm64.cc b/chromium/v8/src/compiler/backend/arm64/instruction-selector-arm64.cc
index d9e388b4b5e..94ba4d78b33 100644
--- a/chromium/v8/src/compiler/backend/arm64/instruction-selector-arm64.cc
+++ b/chromium/v8/src/compiler/backend/arm64/instruction-selector-arm64.cc
@@ -354,6 +354,12 @@ bool TryMatchAnyExtend(Arm64OperandGenerator* g, InstructionSelector* selector,
         return true;
       }
     }
+  } else if (nm.IsChangeInt32ToInt64()) {
+    // Use extended register form.
+    *opcode |= AddressingModeField::encode(kMode_Operand2_R_SXTW);
+    *left_op = g->UseRegister(left_node);
+    *right_op = g->UseRegister(right_node->InputAt(0));
+    return true;
   }
   return false;
 }
@@ -781,11 +787,19 @@ void InstructionSelector::VisitLoad(Node* node) {
       break;
     case MachineRepresentation::kBit:  // Fall through.
     case MachineRepresentation::kWord8:
-      opcode = load_rep.IsSigned() ? kArm64Ldrsb : kArm64Ldrb;
+      opcode = load_rep.IsUnsigned()
+                   ? kArm64Ldrb
+                   : load_rep.semantic() == MachineSemantic::kInt32
+                         ? kArm64LdrsbW
+                         : kArm64Ldrsb;
       immediate_mode = kLoadStoreImm8;
       break;
     case MachineRepresentation::kWord16:
-      opcode = load_rep.IsSigned() ? kArm64Ldrsh : kArm64Ldrh;
+      opcode = load_rep.IsUnsigned()
+                   ? kArm64Ldrh
+                   : load_rep.semantic() == MachineSemantic::kInt32
+                         ? kArm64LdrshW
+                         : kArm64Ldrsh;
       immediate_mode = kLoadStoreImm16;
       break;
     case MachineRepresentation::kWord32:
@@ -827,6 +841,7 @@ void InstructionSelector::VisitLoad(Node* node) {
       opcode = kArm64LdrQ;
       immediate_mode = kNoImmediate;
       break;
+    case MachineRepresentation::kMapWord:  // Fall through.
     case MachineRepresentation::kNone:
       UNREACHABLE();
   }
@@ -936,6 +951,7 @@ void InstructionSelector::VisitStore(Node* node) {
         opcode = kArm64StrQ;
         immediate_mode = kNoImmediate;
         break;
+      case MachineRepresentation::kMapWord:  // Fall through.
       case MachineRepresentation::kNone:
         UNREACHABLE();
     }
@@ -4040,6 +4056,12 @@ void InstructionSelector::VisitI8x16Popcnt(Node* node) {
   VisitRR(this, code, node);
 }
 
+void InstructionSelector::AddOutputToSelectContinuation(OperandGenerator* g,
+                                                        int first_input_index,
+                                                        Node* node) {
+  continuation_outputs_.push_back(g->DefineAsRegister(node));
+}
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
diff --git a/chromium/v8/src/compiler/backend/code-generator.cc b/chromium/v8/src/compiler/backend/code-generator.cc
index 3ed9eaabf14..5abe799e777 100644
--- a/chromium/v8/src/compiler/backend/code-generator.cc
+++ b/chromium/v8/src/compiler/backend/code-generator.cc
@@ -588,11 +588,6 @@ MaybeHandle<Code> CodeGenerator::FinalizeCode() {
     return MaybeHandle<Code>();
   }
 
-  // TODO(jgruber,v8:8888): Turn this into a DCHECK once confidence is
-  // high that the implementation is complete.
-  CHECK_IMPLIES(info()->IsNativeContextIndependent(),
-                code->IsNativeContextIndependent(isolate()));
-
   // Counts both compiled code and metadata.
   isolate()->counters()->total_compiled_code_size()->Increment(
       code->raw_body_size());
@@ -1400,7 +1395,8 @@ void CodeGenerator::AddTranslationForOperand(Instruction* instr,
       default:
         UNREACHABLE();
     }
-    if (literal.object().equals(info()->closure())) {
+    if (literal.object().equals(info()->closure()) &&
+        info()->function_context_specializing()) {
       translations_.StoreJSFrameFunction();
     } else {
       int literal_id = DefineDeoptimizationLiteral(literal);
diff --git a/chromium/v8/src/compiler/backend/ia32/code-generator-ia32.cc b/chromium/v8/src/compiler/backend/ia32/code-generator-ia32.cc
index ac5d589790e..af2eec4e8e2 100644
--- a/chromium/v8/src/compiler/backend/ia32/code-generator-ia32.cc
+++ b/chromium/v8/src/compiler/backend/ia32/code-generator-ia32.cc
@@ -320,18 +320,16 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
   }
 
   void Generate() final {
-    if (mode_ > RecordWriteMode::kValueIsPointer) {
-      __ JumpIfSmi(value_, exit());
-    }
     __ CheckPageFlag(value_, scratch0_,
                      MemoryChunk::kPointersToHereAreInterestingMask, zero,
                      exit());
     __ lea(scratch1_, operand_);
     RememberedSetAction const remembered_set_action =
-        mode_ > RecordWriteMode::kValueIsMap ? EMIT_REMEMBERED_SET
-                                             : OMIT_REMEMBERED_SET;
-    SaveFPRegsMode const save_fp_mode =
-        frame()->DidAllocateDoubleRegisters() ? kSaveFPRegs : kDontSaveFPRegs;
+        mode_ > RecordWriteMode::kValueIsMap ? RememberedSetAction::kEmit
+                                             : RememberedSetAction::kOmit;
+    SaveFPRegsMode const save_fp_mode = frame()->DidAllocateDoubleRegisters()
+                                            ? SaveFPRegsMode::kSave
+                                            : SaveFPRegsMode::kIgnore;
     if (mode_ == RecordWriteMode::kValueIsEphemeronKey) {
       __ CallEphemeronKeyBarrier(object_, scratch1_, save_fp_mode);
 #if V8_ENABLE_WEBASSEMBLY
@@ -832,7 +830,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchSaveCallerRegisters: {
       fp_mode_ =
           static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode()));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // kReturnRegister0 should have been saved before entering the stub.
       int bytes = __ PushCallerSaved(fp_mode_, kReturnRegister0);
       DCHECK(IsAligned(bytes, kSystemPointerSize));
@@ -845,7 +844,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchRestoreCallerRegisters: {
       DCHECK(fp_mode_ ==
              static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode())));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // Don't overwrite the returned value.
       int bytes = __ PopCallerSaved(fp_mode_, kReturnRegister0);
       frame_access_state()->IncreaseSPDelta(-(bytes / kSystemPointerSize));
@@ -1004,6 +1004,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                                                    scratch0, scratch1, mode,
                                                    DetermineStubCallMode());
       __ mov(operand, value);
+      if (mode > RecordWriteMode::kValueIsPointer) {
+        __ JumpIfSmi(value, ool->exit());
+      }
       __ CheckPageFlag(object, scratch0,
                        MemoryChunk::kPointersFromHereAreInterestingMask,
                        not_zero, ool->entry());
@@ -1866,77 +1869,17 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kIA32F64x2Splat: {
-      XMMRegister dst = i.OutputDoubleRegister();
-      XMMRegister src = i.InputDoubleRegister(0);
-      if (CpuFeatures::IsSupported(AVX)) {
-        CpuFeatureScope avx_scope(tasm(), AVX);
-        __ vshufpd(i.OutputSimd128Register(), src, src, 0x0);
-      } else {
-        DCHECK_EQ(dst, src);
-        __ shufpd(dst, src, 0x0);
-      }
-      break;
-    }
-    case kSSEF64x2ExtractLane: {
-      DCHECK_EQ(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
-      XMMRegister dst = i.OutputDoubleRegister();
-      int8_t lane = i.InputInt8(1);
-      if (lane != 0) {
-        DCHECK_EQ(lane, 1);
-        __ shufpd(dst, dst, lane);
-      }
+      __ Movddup(i.OutputSimd128Register(), i.InputDoubleRegister(0));
       break;
     }
-    case kAVXF64x2ExtractLane: {
-      CpuFeatureScope avx_scope(tasm(), AVX);
-      XMMRegister dst = i.OutputDoubleRegister();
-      XMMRegister src = i.InputSimd128Register(0);
-      int8_t lane = i.InputInt8(1);
-      if (lane == 0) {
-        if (dst != src) __ vmovapd(dst, src);
-      } else {
-        DCHECK_EQ(lane, 1);
-        __ vshufpd(dst, src, src, lane);
-      }
+    case kF64x2ExtractLane: {
+      __ F64x2ExtractLane(i.OutputDoubleRegister(), i.InputDoubleRegister(0),
+                          i.InputUint8(1));
       break;
     }
-    case kSSEF64x2ReplaceLane: {
-      DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
-      XMMRegister dst = i.OutputSimd128Register();
-      int8_t lane = i.InputInt8(1);
-      DoubleRegister rep = i.InputDoubleRegister(2);
-
-      // insertps takes a mask which contains (high to low):
-      // - 2 bit specifying source float element to copy
-      // - 2 bit specifying destination float element to write to
-      // - 4 bits specifying which elements of the destination to zero
-      DCHECK_LT(lane, 2);
-      if (lane == 0) {
-        __ insertps(dst, rep, 0b00000000);
-        __ insertps(dst, rep, 0b01010000);
-      } else {
-        __ insertps(dst, rep, 0b00100000);
-        __ insertps(dst, rep, 0b01110000);
-      }
-      break;
-    }
-    case kAVXF64x2ReplaceLane: {
-      CpuFeatureScope avx_scope(tasm(), AVX);
-      XMMRegister dst = i.OutputSimd128Register();
-      XMMRegister src = i.InputSimd128Register(0);
-      int8_t lane = i.InputInt8(1);
-      DoubleRegister rep = i.InputDoubleRegister(2);
-      DCHECK_NE(dst, rep);
-
-      DCHECK_LT(lane, 2);
-      if (lane == 0) {
-        __ vinsertps(dst, src, rep, 0b00000000);
-        __ vinsertps(dst, dst, rep, 0b01010000);
-      } else {
-        __ vinsertps(dst, src, rep, 0b00100000);
-        __ vinsertps(dst, dst, rep, 0b01110000);
-      }
+    case kF64x2ReplaceLane: {
+      __ F64x2ReplaceLane(i.OutputSimd128Register(), i.InputSimd128Register(0),
+                          i.InputDoubleRegister(2), i.InputInt8(1));
       break;
     }
     case kIA32F64x2Sqrt: {
@@ -1964,44 +1907,13 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kIA32F64x2Min: {
-      Operand src1 = i.InputOperand(1);
-      XMMRegister dst = i.OutputSimd128Register(),
-                  src = i.InputSimd128Register(0),
-                  tmp = i.TempSimd128Register(0);
-      // The minpd instruction doesn't propagate NaNs and +0's in its first
-      // operand. Perform minpd in both orders, merge the resuls, and adjust.
-      __ Movupd(tmp, src1);
-      __ Minpd(tmp, tmp, src);
-      __ Minpd(dst, src, src1);
-      // propagate -0's and NaNs, which may be non-canonical.
-      __ Orpd(tmp, dst);
-      // Canonicalize NaNs by quieting and clearing the payload.
-      __ Cmpunordpd(dst, dst, tmp);
-      __ Orpd(tmp, dst);
-      __ Psrlq(dst, 13);
-      __ Andnpd(dst, tmp);
+      __ F64x2Min(i.OutputSimd128Register(), i.InputSimd128Register(0),
+                  i.InputSimd128Register(1), kScratchDoubleReg);
       break;
     }
     case kIA32F64x2Max: {
-      Operand src1 = i.InputOperand(1);
-      XMMRegister dst = i.OutputSimd128Register(),
-                  src = i.InputSimd128Register(0),
-                  tmp = i.TempSimd128Register(0);
-      // The maxpd instruction doesn't propagate NaNs and +0's in its first
-      // operand. Perform maxpd in both orders, merge the resuls, and adjust.
-      __ Movupd(tmp, src1);
-      __ Maxpd(tmp, tmp, src);
-      __ Maxpd(dst, src, src1);
-      // Find discrepancies.
-      __ Xorpd(dst, tmp);
-      // Propagate NaNs, which may be non-canonical.
-      __ Orpd(tmp, dst);
-      // Propagate sign discrepancy and (subtle) quiet NaNs.
-      __ Subpd(tmp, tmp, dst);
-      // Canonicalize NaNs by clearing the payload. Sign is non-deterministic.
-      __ Cmpunordpd(dst, dst, tmp);
-      __ Psrlq(dst, 13);
-      __ Andnpd(dst, tmp);
+      __ F64x2Max(i.OutputSimd128Register(), i.InputSimd128Register(0),
+                  i.InputSimd128Register(1), kScratchDoubleReg);
       break;
     }
     case kIA32F64x2Eq: {
@@ -2158,10 +2070,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kIA32I64x2Neg: {
-      XMMRegister dst = i.OutputSimd128Register();
-      Operand src = i.InputOperand(0);
-      __ Pxor(dst, dst);
-      __ Psubq(dst, src);
+      __ I64x2Neg(i.OutputSimd128Register(), i.InputSimd128Register(0),
+                  kScratchDoubleReg);
       break;
     }
     case kIA32I64x2Shl: {
@@ -2181,7 +2091,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
 
       // Set up a mask [0x80000000,0,0x80000000,0].
       __ Pcmpeqb(tmp2, tmp2);
-      __ Psllq(tmp2, tmp2, 63);
+      __ Psllq(tmp2, tmp2, byte{63});
 
       __ Psrlq(tmp2, tmp2, tmp);
       __ Psrlq(dst, src, tmp);
@@ -2210,15 +2120,15 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ Movaps(tmp2, right);
 
       // Multiply high dword of each qword of left with right.
-      __ Psrlq(tmp1, 32);
+      __ Psrlq(tmp1, byte{32});
       __ Pmuludq(tmp1, tmp1, right);
 
       // Multiply high dword of each qword of right with left.
-      __ Psrlq(tmp2, 32);
+      __ Psrlq(tmp2, byte{32});
       __ Pmuludq(tmp2, tmp2, left);
 
       __ Paddq(tmp2, tmp2, tmp1);
-      __ Psllq(tmp2, tmp2, 32);
+      __ Psllq(tmp2, tmp2, byte{32});
 
       __ Pmuludq(dst, left, right);
       __ Paddq(dst, dst, tmp2);
@@ -2302,38 +2212,12 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kIA32F32x4Splat: {
-      XMMRegister dst = i.OutputDoubleRegister();
-      XMMRegister src = i.InputDoubleRegister(0);
-      if (CpuFeatures::IsSupported(AVX)) {
-        CpuFeatureScope avx_scope(tasm(), AVX);
-        __ vshufps(i.OutputSimd128Register(), src, src, 0x0);
-      } else {
-        DCHECK_EQ(dst, src);
-        __ shufps(dst, src, 0x0);
-      }
+      __ F32x4Splat(i.OutputSimd128Register(), i.InputDoubleRegister(0));
       break;
     }
     case kIA32F32x4ExtractLane: {
-      XMMRegister dst = i.OutputFloatRegister();
-      XMMRegister src = i.InputSimd128Register(0);
-      uint8_t lane = i.InputUint8(1);
-      DCHECK_LT(lane, 4);
-      // These instructions are shorter than insertps, but will leave junk in
-      // the top lanes of dst.
-      if (lane == 0) {
-        if (dst != src) {
-          __ Movaps(dst, src);
-        }
-      } else if (lane == 1) {
-        __ Movshdup(dst, src);
-      } else if (lane == 2 && dst == src) {
-        // Check dst == src to avoid false dependency on dst.
-        __ Movhlps(dst, src);
-      } else if (dst == src) {
-        __ Shufps(dst, src, src, lane);
-      } else {
-        __ Pshufd(dst, src, lane);
-      }
+      __ F32x4ExtractLane(i.OutputFloatRegister(), i.InputSimd128Register(0),
+                          i.InputUint8(1));
       break;
     }
     case kIA32Insertps: {
@@ -2357,10 +2241,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       XMMRegister dst = i.OutputSimd128Register();
       XMMRegister src = i.InputSimd128Register(0);
       __ Pxor(kScratchDoubleReg, kScratchDoubleReg);      // zeros
-      __ Pblendw(kScratchDoubleReg, src, 0x55);           // get lo 16 bits
+      __ Pblendw(kScratchDoubleReg, src, uint8_t{0x55});  // get lo 16 bits
       __ Psubd(dst, src, kScratchDoubleReg);              // get hi 16 bits
       __ Cvtdq2ps(kScratchDoubleReg, kScratchDoubleReg);  // convert lo exactly
-      __ Psrld(dst, dst, 1);    // divide by 2 to get in unsigned range
+      __ Psrld(dst, dst, byte{1});  // divide by 2 to get in unsigned range
       __ Cvtdq2ps(dst, dst);    // convert hi exactly
       __ Addps(dst, dst, dst);  // double hi, exactly
       __ Addps(dst, dst, kScratchDoubleReg);  // add hi and lo, may round.
@@ -2371,11 +2255,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       XMMRegister src = i.InputSimd128Register(0);
       if (dst == src) {
         __ Pcmpeqd(kScratchDoubleReg, kScratchDoubleReg);
-        __ Psrld(kScratchDoubleReg, kScratchDoubleReg, 1);
+        __ Psrld(kScratchDoubleReg, kScratchDoubleReg, byte{1});
         __ Andps(dst, kScratchDoubleReg);
       } else {
         __ Pcmpeqd(dst, dst);
-        __ Psrld(dst, dst, 1);
+        __ Psrld(dst, dst, byte{1});
         __ Andps(dst, src);
       }
       break;
@@ -2385,11 +2269,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       XMMRegister src = i.InputSimd128Register(0);
       if (dst == src) {
         __ Pcmpeqd(kScratchDoubleReg, kScratchDoubleReg);
-        __ Pslld(kScratchDoubleReg, kScratchDoubleReg, 31);
+        __ Pslld(kScratchDoubleReg, kScratchDoubleReg, byte{31});
         __ Xorps(dst, kScratchDoubleReg);
       } else {
         __ Pcmpeqd(dst, dst);
-        __ Pslld(dst, dst, 31);
+        __ Pslld(dst, dst, byte{31});
         __ Xorps(dst, src);
       }
       break;
@@ -2580,7 +2464,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ Cvttps2dq(dst, dst);
       // Set top bit if >=0 is now < 0
       __ Pand(kScratchDoubleReg, dst);
-      __ Psrad(kScratchDoubleReg, kScratchDoubleReg, 31);
+      __ Psrad(kScratchDoubleReg, kScratchDoubleReg, byte{31});
       // Set positive overflow lanes to 0x7FFFFFFF
       __ Pxor(dst, kScratchDoubleReg);
       break;
@@ -3564,15 +3448,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kIA32S128Not: {
-      XMMRegister dst = i.OutputSimd128Register();
-      XMMRegister src = i.InputSimd128Register(0);
-      if (dst == src) {
-        __ Pcmpeqd(kScratchDoubleReg, kScratchDoubleReg);
-        __ Pxor(dst, kScratchDoubleReg);
-      } else {
-        __ Pcmpeqd(dst, dst);
-        __ Pxor(dst, src);
-      }
+      __ S128Not(i.OutputSimd128Register(), i.InputSimd128Register(0),
+                 kScratchDoubleReg);
       break;
     }
     case kSSES128And: {
@@ -3739,7 +3616,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       DCHECK_NE(0xe4, shuffle);  // A simple blend should be handled below.
       __ Pshufd(kScratchDoubleReg, i.InputOperand(1), shuffle);
       __ Pshufd(i.OutputSimd128Register(), i.InputOperand(0), shuffle);
-      __ Pblendw(i.OutputSimd128Register(), kScratchDoubleReg, i.InputInt8(3));
+      __ Pblendw(i.OutputSimd128Register(), kScratchDoubleReg, i.InputUint8(3));
       break;
     }
     case kIA32S16x8Blend:
@@ -3757,7 +3634,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ Pshufhw(kScratchDoubleReg, kScratchDoubleReg, i.InputUint8(3));
       __ Pshuflw(dst, i.InputOperand(0), i.InputUint8(2));
       __ Pshufhw(dst, dst, i.InputUint8(3));
-      __ Pblendw(dst, kScratchDoubleReg, i.InputInt8(4));
+      __ Pblendw(dst, kScratchDoubleReg, i.InputUint8(4));
       break;
     }
     case kIA32S8x16Alignr:
@@ -4250,7 +4127,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
   }
   return kSuccess;
-}  // NOLINT(readability/fn_size)
+}
 
 static Condition FlagsConditionToCondition(FlagsCondition condition) {
   switch (condition) {
@@ -4649,7 +4526,7 @@ void CodeGenerator::AssembleConstructFrame() {
     // frame is still on the stack. Optimized code uses OSR values directly from
     // the unoptimized frame. Thus, all that needs to be done is to allocate the
     // remaining stack slots.
-    if (FLAG_code_comments) __ RecordComment("-- OSR entrypoint --");
+    __ RecordComment("-- OSR entrypoint --");
     osr_pc_offset_ = __ pc_offset();
     required_slots -= osr_helper()->UnoptimizedFrameSlots();
   }
@@ -4738,7 +4615,7 @@ void CodeGenerator::AssembleReturn(InstructionOperand* additional_pop_count) {
   if (parameter_slots != 0) {
     if (additional_pop_count->IsImmediate()) {
       DCHECK_EQ(g.ToConstant(additional_pop_count).ToInt32(), 0);
-    } else if (__ emit_debug_code()) {
+    } else if (FLAG_debug_code) {
       __ cmp(g.ToRegister(additional_pop_count), Immediate(0));
       __ Assert(equal, AbortReason::kUnexpectedAdditionalPopValue);
     }
diff --git a/chromium/v8/src/compiler/backend/ia32/instruction-codes-ia32.h b/chromium/v8/src/compiler/backend/ia32/instruction-codes-ia32.h
index f06ed5156e8..42af3326f3a 100644
--- a/chromium/v8/src/compiler/backend/ia32/instruction-codes-ia32.h
+++ b/chromium/v8/src/compiler/backend/ia32/instruction-codes-ia32.h
@@ -117,10 +117,8 @@ namespace compiler {
   V(IA32Poke)                      \
   V(IA32Peek)                      \
   V(IA32F64x2Splat)                \
-  V(SSEF64x2ExtractLane)           \
-  V(AVXF64x2ExtractLane)           \
-  V(SSEF64x2ReplaceLane)           \
-  V(AVXF64x2ReplaceLane)           \
+  V(F64x2ExtractLane)              \
+  V(F64x2ReplaceLane)              \
   V(IA32F64x2Sqrt)                 \
   V(IA32F64x2Add)                  \
   V(IA32F64x2Sub)                  \
diff --git a/chromium/v8/src/compiler/backend/ia32/instruction-scheduler-ia32.cc b/chromium/v8/src/compiler/backend/ia32/instruction-scheduler-ia32.cc
index 3d1c7073591..278e7ea99b9 100644
--- a/chromium/v8/src/compiler/backend/ia32/instruction-scheduler-ia32.cc
+++ b/chromium/v8/src/compiler/backend/ia32/instruction-scheduler-ia32.cc
@@ -102,10 +102,8 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kIA32BitcastFI:
     case kIA32BitcastIF:
     case kIA32F64x2Splat:
-    case kSSEF64x2ExtractLane:
-    case kAVXF64x2ExtractLane:
-    case kSSEF64x2ReplaceLane:
-    case kAVXF64x2ReplaceLane:
+    case kF64x2ExtractLane:
+    case kF64x2ReplaceLane:
     case kIA32F64x2Sqrt:
     case kIA32F64x2Add:
     case kIA32F64x2Sub:
diff --git a/chromium/v8/src/compiler/backend/ia32/instruction-selector-ia32.cc b/chromium/v8/src/compiler/backend/ia32/instruction-selector-ia32.cc
index 033a566e113..703d574eed8 100644
--- a/chromium/v8/src/compiler/backend/ia32/instruction-selector-ia32.cc
+++ b/chromium/v8/src/compiler/backend/ia32/instruction-selector-ia32.cc
@@ -65,7 +65,8 @@ class IA32OperandGenerator final : public OperandGenerator {
 
   bool CanBeMemoryOperand(InstructionCode opcode, Node* node, Node* input,
                           int effect_level) {
-    if (input->opcode() != IrOpcode::kLoad ||
+    if ((input->opcode() != IrOpcode::kLoad &&
+         input->opcode() != IrOpcode::kLoadImmutable) ||
         !selector()->CanCover(node, input)) {
       return false;
     }
@@ -551,6 +552,7 @@ void InstructionSelector::VisitLoad(Node* node) {
     case MachineRepresentation::kCompressed:         // Fall through.
     case MachineRepresentation::kWord64:             // Fall through.
     case MachineRepresentation::kNone:
+    case MachineRepresentation::kMapWord:
       UNREACHABLE();
   }
 
@@ -633,6 +635,7 @@ void InstructionSelector::VisitStore(Node* node) {
       case MachineRepresentation::kCompressedPointer:  // Fall through.
       case MachineRepresentation::kCompressed:         // Fall through.
       case MachineRepresentation::kWord64:             // Fall through.
+      case MachineRepresentation::kMapWord:            // Fall through.
       case MachineRepresentation::kNone:
         UNREACHABLE();
     }
@@ -816,7 +819,8 @@ void InstructionSelector::VisitStackPointerGreaterThan(
 
   Node* const value = node->InputAt(0);
   if (g.CanBeMemoryOperand(kIA32Cmp, node, value, effect_level)) {
-    DCHECK_EQ(IrOpcode::kLoad, value->opcode());
+    DCHECK(value->opcode() == IrOpcode::kLoad ||
+           value->opcode() == IrOpcode::kLoadImmutable);
 
     // GetEffectiveAddressMemoryOperand can create at most 3 inputs.
     static constexpr int kMaxInputCount = 3;
@@ -1432,7 +1436,8 @@ void VisitCompareWithMemoryOperand(InstructionSelector* selector,
                                    InstructionCode opcode, Node* left,
                                    InstructionOperand right,
                                    FlagsContinuation* cont) {
-  DCHECK_EQ(IrOpcode::kLoad, left->opcode());
+  DCHECK(left->opcode() == IrOpcode::kLoad ||
+         left->opcode() == IrOpcode::kLoadImmutable);
   IA32OperandGenerator g(selector);
   size_t input_count = 0;
   InstructionOperand inputs[4];
@@ -1463,7 +1468,8 @@ void VisitCompare(InstructionSelector* selector, InstructionCode opcode,
 }
 
 MachineType MachineTypeForNarrow(Node* node, Node* hint_node) {
-  if (hint_node->opcode() == IrOpcode::kLoad) {
+  if (hint_node->opcode() == IrOpcode::kLoad ||
+      hint_node->opcode() == IrOpcode::kLoadImmutable) {
     MachineType hint = LoadRepresentationOf(hint_node->op());
     if (node->opcode() == IrOpcode::kInt32Constant ||
         node->opcode() == IrOpcode::kInt64Constant) {
@@ -1497,8 +1503,10 @@ MachineType MachineTypeForNarrow(Node* node, Node* hint_node) {
       }
     }
   }
-  return node->opcode() == IrOpcode::kLoad ? LoadRepresentationOf(node->op())
-                                           : MachineType::None();
+  return node->opcode() == IrOpcode::kLoad ||
+                 node->opcode() == IrOpcode::kLoadImmutable
+             ? LoadRepresentationOf(node->op())
+             : MachineType::None();
 }
 
 // Tries to match the size of the given opcode to that of the operands, if
@@ -2346,30 +2354,24 @@ void InstructionSelector::VisitS128Const(Node* node) {
 
 void InstructionSelector::VisitF64x2Min(Node* node) {
   IA32OperandGenerator g(this);
-  InstructionOperand temps[] = {g.TempSimd128Register()};
-  InstructionOperand operand0 = g.UseUniqueRegister(node->InputAt(0));
-  InstructionOperand operand1 = g.UseUniqueRegister(node->InputAt(1));
+  InstructionOperand operand0 = g.UseRegister(node->InputAt(0));
+  InstructionOperand operand1 = g.UseRegister(node->InputAt(1));
 
   if (IsSupported(AVX)) {
-    Emit(kIA32F64x2Min, g.DefineAsRegister(node), operand0, operand1,
-         arraysize(temps), temps);
+    Emit(kIA32F64x2Min, g.DefineAsRegister(node), operand0, operand1);
   } else {
-    Emit(kIA32F64x2Min, g.DefineSameAsFirst(node), operand0, operand1,
-         arraysize(temps), temps);
+    Emit(kIA32F64x2Min, g.DefineSameAsFirst(node), operand0, operand1);
   }
 }
 
 void InstructionSelector::VisitF64x2Max(Node* node) {
   IA32OperandGenerator g(this);
-  InstructionOperand temps[] = {g.TempSimd128Register()};
-  InstructionOperand operand0 = g.UseUniqueRegister(node->InputAt(0));
-  InstructionOperand operand1 = g.UseUniqueRegister(node->InputAt(1));
+  InstructionOperand operand0 = g.UseRegister(node->InputAt(0));
+  InstructionOperand operand1 = g.UseRegister(node->InputAt(1));
   if (IsSupported(AVX)) {
-    Emit(kIA32F64x2Max, g.DefineAsRegister(node), operand0, operand1,
-         arraysize(temps), temps);
+    Emit(kIA32F64x2Max, g.DefineAsRegister(node), operand0, operand1);
   } else {
-    Emit(kIA32F64x2Max, g.DefineSameAsFirst(node), operand0, operand1,
-         arraysize(temps), temps);
+    Emit(kIA32F64x2Max, g.DefineSameAsFirst(node), operand0, operand1);
   }
 }
 
@@ -2378,7 +2380,7 @@ void InstructionSelector::VisitF64x2Splat(Node* node) {
 }
 
 void InstructionSelector::VisitF64x2ExtractLane(Node* node) {
-  VisitRRISimd(this, node, kAVXF64x2ExtractLane, kSSEF64x2ExtractLane);
+  VisitRRISimd(this, node, kF64x2ExtractLane, kF64x2ExtractLane);
 }
 
 void InstructionSelector::VisitI64x2SplatI32Pair(Node* node) {
@@ -2406,7 +2408,10 @@ void InstructionSelector::VisitI64x2ReplaceLaneI32Pair(Node* node) {
 
 void InstructionSelector::VisitI64x2Neg(Node* node) {
   IA32OperandGenerator g(this);
-  InstructionOperand operand0 = g.UseUnique(node->InputAt(0));
+  // If AVX unsupported, make sure dst != src to avoid a move.
+  InstructionOperand operand0 = IsSupported(AVX)
+                                    ? g.UseRegister(node->InputAt(0))
+                                    : g.UseUnique(node->InputAt(0));
   Emit(kIA32I64x2Neg, g.DefineAsRegister(node), operand0);
 }
 
@@ -2546,27 +2551,15 @@ SIMD_REPLACE_LANE_TYPE_OP(VISIT_SIMD_REPLACE_LANE)
 #undef VISIT_SIMD_REPLACE_LANE
 #undef SIMD_REPLACE_LANE_TYPE_OP
 
-// The difference between this and VISIT_SIMD_REPLACE_LANE is that this forces
-// operand2 to be UseRegister, because the codegen relies on insertps using
-// registers.
-// TODO(v8:9764) Remove this UseRegister requirement
-#define VISIT_SIMD_REPLACE_LANE_USE_REG(Type)                            \
-  void InstructionSelector::Visit##Type##ReplaceLane(Node* node) {       \
-    IA32OperandGenerator g(this);                                        \
-    InstructionOperand operand0 = g.UseRegister(node->InputAt(0));       \
-    InstructionOperand operand1 =                                        \
-        g.UseImmediate(OpParameter<int32_t>(node->op()));                \
-    InstructionOperand operand2 = g.UseUniqueRegister(node->InputAt(1)); \
-    if (IsSupported(AVX)) {                                              \
-      Emit(kAVX##Type##ReplaceLane, g.DefineAsRegister(node), operand0,  \
-           operand1, operand2);                                          \
-    } else {                                                             \
-      Emit(kSSE##Type##ReplaceLane, g.DefineSameAsFirst(node), operand0, \
-           operand1, operand2);                                          \
-    }                                                                    \
-  }
-VISIT_SIMD_REPLACE_LANE_USE_REG(F64x2)
-#undef VISIT_SIMD_REPLACE_LANE_USE_REG
+void InstructionSelector::VisitF64x2ReplaceLane(Node* node) {
+  IA32OperandGenerator g(this);
+  int32_t lane = OpParameter<int32_t>(node->op());
+  // When no-AVX, define dst == src to save a move.
+  InstructionOperand dst =
+      IsSupported(AVX) ? g.DefineAsRegister(node) : g.DefineSameAsFirst(node);
+  Emit(kF64x2ReplaceLane, dst, g.UseRegister(node->InputAt(0)),
+       g.UseImmediate(lane), g.UseRegister(node->InputAt(1)));
+}
 
 #define VISIT_SIMD_SHIFT_UNIFIED_SSE_AVX(Opcode)        \
   void InstructionSelector::Visit##Opcode(Node* node) { \
@@ -3159,6 +3152,12 @@ void InstructionSelector::VisitI64x2Abs(Node* node) {
   VisitRRSimd(this, node, kIA32I64x2Abs, kIA32I64x2Abs);
 }
 
+void InstructionSelector::AddOutputToSelectContinuation(OperandGenerator* g,
+                                                        int first_input_index,
+                                                        Node* node) {
+  UNREACHABLE();
+}
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
diff --git a/chromium/v8/src/compiler/backend/instruction-scheduler.h b/chromium/v8/src/compiler/backend/instruction-scheduler.h
index a7c1cc52460..c22190bd50f 100644
--- a/chromium/v8/src/compiler/backend/instruction-scheduler.h
+++ b/chromium/v8/src/compiler/backend/instruction-scheduler.h
@@ -6,15 +6,11 @@
 #define V8_COMPILER_BACKEND_INSTRUCTION_SCHEDULER_H_
 
 #include "src/base/optional.h"
+#include "src/base/utils/random-number-generator.h"
 #include "src/compiler/backend/instruction.h"
 #include "src/zone/zone-containers.h"
 
 namespace v8 {
-
-namespace base {
-class RandomNumberGenerator;
-}  // namespace base
-
 namespace internal {
 namespace compiler {
 
diff --git a/chromium/v8/src/compiler/backend/instruction-selector-impl.h b/chromium/v8/src/compiler/backend/instruction-selector-impl.h
index 7e1f183fb71..539ba5dc255 100644
--- a/chromium/v8/src/compiler/backend/instruction-selector-impl.h
+++ b/chromium/v8/src/compiler/backend/instruction-selector-impl.h
@@ -85,10 +85,12 @@ class OperandGenerator {
                                      GetVReg(node)));
   }
 
+  InstructionOperand DefineSameAsInput(Node* node, int input_index) {
+    return Define(node, UnallocatedOperand(GetVReg(node), input_index));
+  }
+
   InstructionOperand DefineSameAsFirst(Node* node) {
-    return Define(node,
-                  UnallocatedOperand(UnallocatedOperand::SAME_AS_FIRST_INPUT,
-                                     GetVReg(node)));
+    return DefineSameAsInput(node, 0);
   }
 
   InstructionOperand DefineAsFixed(Node* node, Register reg) {
@@ -224,7 +226,7 @@ class OperandGenerator {
   int AllocateVirtualRegister() { return sequence()->NextVirtualRegister(); }
 
   InstructionOperand DefineSameAsFirstForVreg(int vreg) {
-    return UnallocatedOperand(UnallocatedOperand::SAME_AS_FIRST_INPUT, vreg);
+    return UnallocatedOperand(UnallocatedOperand::SAME_AS_INPUT, vreg);
   }
 
   InstructionOperand DefineAsRegistertForVreg(int vreg) {
diff --git a/chromium/v8/src/compiler/backend/instruction-selector.cc b/chromium/v8/src/compiler/backend/instruction-selector.cc
index 5638ff1241a..c806ad8bbe7 100644
--- a/chromium/v8/src/compiler/backend/instruction-selector.cc
+++ b/chromium/v8/src/compiler/backend/instruction-selector.cc
@@ -9,6 +9,7 @@
 #include "src/base/iterator.h"
 #include "src/base/platform/wrappers.h"
 #include "src/codegen/assembler-inl.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/tick-counter.h"
 #include "src/compiler/backend/instruction-selector-impl.h"
 #include "src/compiler/compiler-source-position-table.h"
@@ -802,11 +803,6 @@ size_t InstructionSelector::AddInputsToFrameStateDescriptor(
 }
 
 Instruction* InstructionSelector::EmitWithContinuation(
-    InstructionCode opcode, FlagsContinuation* cont) {
-  return EmitWithContinuation(opcode, 0, nullptr, 0, nullptr, cont);
-}
-
-Instruction* InstructionSelector::EmitWithContinuation(
     InstructionCode opcode, InstructionOperand a, FlagsContinuation* cont) {
   return EmitWithContinuation(opcode, 0, nullptr, 1, &a, cont);
 }
@@ -880,8 +876,16 @@ Instruction* InstructionSelector::EmitWithContinuation(
     AppendDeoptimizeArguments(&continuation_inputs_, cont->kind(),
                               cont->reason(), cont->feedback(),
                               FrameState{cont->frame_state()});
-  } else if (cont->IsSet() || cont->IsSelect()) {
+  } else if (cont->IsSet()) {
     continuation_outputs_.push_back(g.DefineAsRegister(cont->result()));
+  } else if (cont->IsSelect()) {
+    // The {Select} should put one of two values into the output register,
+    // depending on the result of the condition. The two result values are in
+    // the last two input slots, the {false_value} in {input_count - 2}, and the
+    // true_value in {input_count - 1}. The other inputs are used for the
+    // condition.
+    AddOutputToSelectContinuation(&g, static_cast<int>(input_count) - 2,
+                                  cont->result());
   } else if (cont->IsTrap()) {
     int trap_id = static_cast<int>(cont->trap_id());
     continuation_inputs_.push_back(g.UseImmediate(trap_id));
@@ -1554,6 +1558,8 @@ void InstructionSelector::VisitNode(Node* node) {
       return MarkAsWord32(node), VisitWord32Popcnt(node);
     case IrOpcode::kWord64Popcnt:
       return MarkAsWord32(node), VisitWord64Popcnt(node);
+    case IrOpcode::kWord32Select:
+      return MarkAsWord32(node), VisitSelect(node);
     case IrOpcode::kWord64And:
       return MarkAsWord64(node), VisitWord64And(node);
     case IrOpcode::kWord64Or:
@@ -1584,6 +1590,8 @@ void InstructionSelector::VisitNode(Node* node) {
       return MarkAsWord64(node), VisitInt64AbsWithOverflow(node);
     case IrOpcode::kWord64Equal:
       return VisitWord64Equal(node);
+    case IrOpcode::kWord64Select:
+      return MarkAsWord64(node), VisitSelect(node);
     case IrOpcode::kInt32Add:
       return MarkAsWord32(node), VisitInt32Add(node);
     case IrOpcode::kInt32AddWithOverflow:
@@ -2842,7 +2850,7 @@ constexpr InstructionCode EncodeCallDescriptorFlags(
   // Note: Not all bits of `flags` are preserved.
   STATIC_ASSERT(CallDescriptor::kFlagsBitsEncodedInInstructionCode ==
                 MiscField::kSize);
-  CONSTEXPR_DCHECK(Instruction::IsCallWithDescriptorFlags(opcode));
+  DCHECK(Instruction::IsCallWithDescriptorFlags(opcode));
   return opcode | MiscField::encode(flags & MiscField::kMax);
 }
 
@@ -2927,8 +2935,8 @@ void InstructionSelector::VisitCall(Node* node, BasicBlock* handler) {
 
   if (call_descriptor->NeedsCallerSavedRegisters()) {
     SaveFPRegsMode mode = call_descriptor->NeedsCallerSavedFPRegisters()
-                              ? kSaveFPRegs
-                              : kDontSaveFPRegs;
+                              ? SaveFPRegsMode::kSave
+                              : SaveFPRegsMode::kIgnore;
     Emit(kArchSaveCallerRegisters | MiscField::encode(static_cast<int>(mode)),
          g.NoOutput());
   }
@@ -3007,8 +3015,8 @@ void InstructionSelector::VisitCall(Node* node, BasicBlock* handler) {
 
   if (call_descriptor->NeedsCallerSavedRegisters()) {
     SaveFPRegsMode mode = call_descriptor->NeedsCallerSavedFPRegisters()
-                              ? kSaveFPRegs
-                              : kDontSaveFPRegs;
+                              ? SaveFPRegsMode::kSave
+                              : SaveFPRegsMode::kIgnore;
     Emit(
         kArchRestoreCallerRegisters | MiscField::encode(static_cast<int>(mode)),
         g.NoOutput());
diff --git a/chromium/v8/src/compiler/backend/instruction-selector.h b/chromium/v8/src/compiler/backend/instruction-selector.h
index 8984c05c3a6..8bfe7fff6f7 100644
--- a/chromium/v8/src/compiler/backend/instruction-selector.h
+++ b/chromium/v8/src/compiler/backend/instruction-selector.h
@@ -680,6 +680,9 @@ class V8_EXPORT_PRIVATE InstructionSelector final {
 
   bool CanProduceSignalingNaN(Node* node);
 
+  void AddOutputToSelectContinuation(OperandGenerator* g, int first_input_index,
+                                     Node* node);
+
   // ===========================================================================
   // ============= Vector instruction (SIMD) helper fns. =======================
   // ===========================================================================
diff --git a/chromium/v8/src/compiler/backend/instruction.cc b/chromium/v8/src/compiler/backend/instruction.cc
index 43824e8fcb9..f90a249d9a3 100644
--- a/chromium/v8/src/compiler/backend/instruction.cc
+++ b/chromium/v8/src/compiler/backend/instruction.cc
@@ -155,8 +155,8 @@ std::ostream& operator<<(std::ostream& os, const InstructionOperand& op) {
           return os << "(R)";
         case UnallocatedOperand::MUST_HAVE_SLOT:
           return os << "(S)";
-        case UnallocatedOperand::SAME_AS_FIRST_INPUT:
-          return os << "(1)";
+        case UnallocatedOperand::SAME_AS_INPUT:
+          return os << "(" << unalloc->input_index() << ")";
         case UnallocatedOperand::REGISTER_OR_SLOT:
           return os << "(-)";
         case UnallocatedOperand::REGISTER_OR_SLOT_OR_CONSTANT:
@@ -247,6 +247,8 @@ std::ostream& operator<<(std::ostream& os, const InstructionOperand& op) {
         case MachineRepresentation::kCompressed:
           os << "|c";
           break;
+        case MachineRepresentation::kMapWord:
+          UNREACHABLE();
       }
       return os << "]";
     }
@@ -914,6 +916,7 @@ static MachineRepresentation FilterRepresentation(MachineRepresentation rep) {
     case MachineRepresentation::kCompressed:
       return rep;
     case MachineRepresentation::kNone:
+    case MachineRepresentation::kMapWord:
       break;
   }
 
diff --git a/chromium/v8/src/compiler/backend/instruction.h b/chromium/v8/src/compiler/backend/instruction.h
index 88a114e08e2..33146f3c4f0 100644
--- a/chromium/v8/src/compiler/backend/instruction.h
+++ b/chromium/v8/src/compiler/backend/instruction.h
@@ -185,7 +185,7 @@ class UnallocatedOperand final : public InstructionOperand {
     FIXED_FP_REGISTER,
     MUST_HAVE_REGISTER,
     MUST_HAVE_SLOT,
-    SAME_AS_FIRST_INPUT
+    SAME_AS_INPUT
   };
 
   // Lifetime of operand inside the instruction.
@@ -208,6 +208,14 @@ class UnallocatedOperand final : public InstructionOperand {
     value_ |= LifetimeField::encode(USED_AT_END);
   }
 
+  UnallocatedOperand(int virtual_register, int input_index)
+      : UnallocatedOperand(virtual_register) {
+    value_ |= BasicPolicyField::encode(EXTENDED_POLICY);
+    value_ |= ExtendedPolicyField::encode(SAME_AS_INPUT);
+    value_ |= LifetimeField::encode(USED_AT_END);
+    value_ |= InputIndexField::encode(input_index);
+  }
+
   UnallocatedOperand(BasicPolicy policy, int index, int virtual_register)
       : UnallocatedOperand(virtual_register) {
     DCHECK(policy == FIXED_SLOT);
@@ -270,7 +278,7 @@ class UnallocatedOperand final : public InstructionOperand {
   }
   bool HasSameAsInputPolicy() const {
     return basic_policy() == EXTENDED_POLICY &&
-           extended_policy() == SAME_AS_FIRST_INPUT;
+           extended_policy() == SAME_AS_INPUT;
   }
   bool HasFixedSlotPolicy() const { return basic_policy() == FIXED_SLOT; }
   bool HasFixedRegisterPolicy() const {
@@ -300,6 +308,11 @@ class UnallocatedOperand final : public InstructionOperand {
     return ExtendedPolicyField::decode(value_);
   }
 
+  int input_index() const {
+    DCHECK(HasSameAsInputPolicy());
+    return InputIndexField::decode(value_);
+  }
+
   // [fixed_slot_index]: Only for FIXED_SLOT.
   int fixed_slot_index() const {
     DCHECK(HasFixedSlotPolicy());
@@ -362,6 +375,7 @@ class UnallocatedOperand final : public InstructionOperand {
   using HasSecondaryStorageField = base::BitField64<bool, 40, 1>;
   using FixedRegisterField = base::BitField64<int, 41, 6>;
   using SecondaryStorageField = base::BitField64<int, 47, 3>;
+  using InputIndexField = base::BitField64<int, 50, 3>;
 
  private:
   explicit UnallocatedOperand(int virtual_register)
@@ -545,6 +559,8 @@ class LocationOperand : public InstructionOperand {
       case MachineRepresentation::kWord16:
       case MachineRepresentation::kNone:
         return false;
+      case MachineRepresentation::kMapWord:
+        break;
     }
     UNREACHABLE();
   }
diff --git a/chromium/v8/src/compiler/backend/mid-tier-register-allocator.cc b/chromium/v8/src/compiler/backend/mid-tier-register-allocator.cc
index 394f319dc03..ee9cd3dddee 100644
--- a/chromium/v8/src/compiler/backend/mid-tier-register-allocator.cc
+++ b/chromium/v8/src/compiler/backend/mid-tier-register-allocator.cc
@@ -587,8 +587,7 @@ void VirtualRegisterData::AddSpillUse(int instr_index,
 
   const InstructionBlock* block = data->GetBlock(instr_index);
   if (CouldSpillOnEntryToDeferred(block)) {
-    // TODO(1180335): Remove once crbug.com/1180335 is fixed.
-    CHECK(HasSpillRange());
+    DCHECK(HasSpillRange());
     data->block_state(block->rpo_number())
         .deferred_blocks_region()
         ->DeferSpillOutputUntilEntry(vreg());
@@ -614,8 +613,7 @@ void VirtualRegisterData::AddDeferredSpillOutput(
     AllocatedOperand allocated_op, int instr_index,
     MidTierRegisterAllocationData* data) {
   DCHECK(!NeedsSpillAtOutput());
-  // TODO(1180335): Make DCHECK once crbug.com/1180335 is fixed.
-  CHECK(HasSpillRange());
+  DCHECK(HasSpillRange());
   spill_range_->AddDeferredSpillOutput(allocated_op, instr_index, data);
 }
 
@@ -937,9 +935,8 @@ void RegisterState::Register::Use(int virtual_register, int instr_index) {
   // A register can have many pending uses, but should only ever have a single
   // non-pending use, since any subsiquent use will commit the preceeding use
   // first.
-  // TODO(1180335): Make DCHECK once crbug.com/1180335 is fixed.
-  CHECK(!is_allocated());
-  CHECK(!is_shared());
+  DCHECK(!is_allocated());
+  DCHECK(!is_shared());
   needs_gap_move_on_spill_ = true;
   virtual_register_ = virtual_register;
   last_use_instr_index_ = instr_index;
@@ -950,8 +947,7 @@ void RegisterState::Register::PendingUse(InstructionOperand* operand,
                                          int virtual_register,
                                          bool can_be_constant,
                                          int instr_index) {
-  // TODO(1180335): Make DCHECK once crbug.com/1180335 is fixed.
-  CHECK(!was_spilled_while_shared());
+  DCHECK(!was_spilled_while_shared());
   if (!is_allocated()) {
     virtual_register_ = virtual_register;
     last_use_instr_index_ = instr_index;
@@ -972,8 +968,7 @@ void RegisterState::Register::MarkAsPhiMove() {
 
 void RegisterState::Register::AddDeferredBlockSpill(int instr_index,
                                                     bool on_exit, Zone* zone) {
-  // TODO(1180335): Make DCHECK once crbug.com/1180335 is fixed.
-  CHECK(is_allocated());
+  DCHECK(is_allocated());
   if (!deferred_block_spills_) {
     deferred_block_spills_.emplace(zone);
   }
@@ -981,16 +976,14 @@ void RegisterState::Register::AddDeferredBlockSpill(int instr_index,
 }
 
 void RegisterState::Register::AddSharedUses(int shared_use_count) {
-  // TODO(1180335): Make DCHECK once crbug.com/1180335 is fixed.
-  CHECK(!was_spilled_while_shared());
+  DCHECK(!was_spilled_while_shared());
   is_shared_ = true;
   num_commits_required_ += shared_use_count;
 }
 
 void RegisterState::Register::CommitAtMerge() {
-  // TODO(1180335): Make DCHECK once crbug.com/1180335 is fixed.
-  CHECK(is_shared());
-  CHECK(is_allocated());
+  DCHECK(is_shared());
+  DCHECK(is_allocated());
   --num_commits_required_;
   // We should still have commits required that will be resolved in the merge
   // block.
@@ -999,9 +992,8 @@ void RegisterState::Register::CommitAtMerge() {
 
 void RegisterState::Register::Commit(AllocatedOperand allocated_op,
                                      MidTierRegisterAllocationData* data) {
-  // TODO(1180335): Make DCHECK once crbug.com/1180335 is fixed.
-  CHECK(is_allocated());
-  CHECK_GT(num_commits_required_, 0);
+  DCHECK(is_allocated());
+  DCHECK_GT(num_commits_required_, 0);
 
   if (--num_commits_required_ == 0) {
     // Allocate all pending uses to |allocated_op| if this commit is non-shared,
@@ -1038,8 +1030,7 @@ void RegisterState::Register::Commit(AllocatedOperand allocated_op,
       vreg_data.EmitDeferredSpillOutputs(data);
     }
   }
-  // TODO(1180335): Make DCHECK once crbug.com/1180335 is fixed.
-  CHECK_IMPLIES(num_commits_required_ > 0, is_shared());
+  DCHECK_IMPLIES(num_commits_required_ > 0, is_shared());
 }
 
 void RegisterState::Register::Spill(AllocatedOperand allocated_op,
@@ -1106,9 +1097,8 @@ void RegisterState::Register::SpillPendingUses(
 void RegisterState::Register::SpillForDeferred(
     AllocatedOperand allocated, int instr_index,
     MidTierRegisterAllocationData* data) {
-  // TODO(1180335): Make DCHECK once crbug.com/1180335 is fixed.
-  CHECK(is_allocated());
-  CHECK(is_shared());
+  DCHECK(is_allocated());
+  DCHECK(is_shared());
   // Add a pending deferred spill, then commit the register (with the commit
   // being fullfilled by the deferred spill if the register is fully commited).
   data->VirtualRegisterDataFor(virtual_register())
@@ -1120,8 +1110,7 @@ void RegisterState::Register::SpillForDeferred(
 void RegisterState::Register::MoveToSpillSlotOnDeferred(
     int virtual_register, int instr_index,
     MidTierRegisterAllocationData* data) {
-  // TODO(1180335): Make DCHECK once crbug.com/1180335 is fixed.
-  CHECK(!was_spilled_while_shared());
+  DCHECK(!was_spilled_while_shared());
   if (!is_allocated()) {
     virtual_register_ = virtual_register;
     last_use_instr_index_ = instr_index;
@@ -2168,8 +2157,7 @@ void SinglePassRegisterAllocator::AllocateDeferredBlockSpillOutput(
     int instr_index, RpoNumber deferred_block,
     VirtualRegisterData& virtual_register) {
   DCHECK(data()->GetBlock(deferred_block)->IsDeferred());
-  // TODO(1180335): Make DCHECK once crbug.com/1180335 is fixed.
-  CHECK(virtual_register.HasSpillRange());
+  DCHECK(virtual_register.HasSpillRange());
   if (!virtual_register.NeedsSpillAtOutput() &&
       !DefinedAfter(virtual_register.vreg(), instr_index, UsePosition::kEnd)) {
     // If a register has been assigned to the virtual register, and the virtual
diff --git a/chromium/v8/src/compiler/backend/mips/code-generator-mips.cc b/chromium/v8/src/compiler/backend/mips/code-generator-mips.cc
index 4066ba77e80..4e7b69e45b4 100644
--- a/chromium/v8/src/compiler/backend/mips/code-generator-mips.cc
+++ b/chromium/v8/src/compiler/backend/mips/code-generator-mips.cc
@@ -161,18 +161,16 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
   }
 
   void Generate() final {
-    if (mode_ > RecordWriteMode::kValueIsPointer) {
-      __ JumpIfSmi(value_, exit());
-    }
     __ CheckPageFlag(value_, scratch0_,
                      MemoryChunk::kPointersToHereAreInterestingMask, eq,
                      exit());
     __ Addu(scratch1_, object_, index_);
     RememberedSetAction const remembered_set_action =
-        mode_ > RecordWriteMode::kValueIsMap ? EMIT_REMEMBERED_SET
-                                             : OMIT_REMEMBERED_SET;
-    SaveFPRegsMode const save_fp_mode =
-        frame()->DidAllocateDoubleRegisters() ? kSaveFPRegs : kDontSaveFPRegs;
+        mode_ > RecordWriteMode::kValueIsMap ? RememberedSetAction::kEmit
+                                             : RememberedSetAction::kOmit;
+    SaveFPRegsMode const save_fp_mode = frame()->DidAllocateDoubleRegisters()
+                                            ? SaveFPRegsMode::kSave
+                                            : SaveFPRegsMode::kIgnore;
     if (must_save_lr_) {
       // We need to save and restore ra if the frame was elided.
       __ Push(ra);
@@ -373,10 +371,10 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
     } else {                                                                   \
       FrameScope scope(tasm(), StackFrame::MANUAL);                            \
       __ Addu(a0, i.InputRegister(0), i.InputRegister(1));                     \
-      __ PushCallerSaved(kDontSaveFPRegs, v0, v1);                             \
+      __ PushCallerSaved(SaveFPRegsMode::kIgnore, v0, v1);                     \
       __ PrepareCallCFunction(3, 0, kScratchReg);                              \
       __ CallCFunction(ExternalReference::external(), 3, 0);                   \
-      __ PopCallerSaved(kDontSaveFPRegs, v0, v1);                              \
+      __ PopCallerSaved(SaveFPRegsMode::kIgnore, v0, v1);                      \
     }                                                                          \
   } while (0)
 
@@ -403,10 +401,10 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
     } else {                                                                   \
       FrameScope scope(tasm(), StackFrame::MANUAL);                            \
       __ Addu(a0, i.InputRegister(0), i.InputRegister(1));                     \
-      __ PushCallerSaved(kDontSaveFPRegs, v0, v1);                             \
+      __ PushCallerSaved(SaveFPRegsMode::kIgnore, v0, v1);                     \
       __ PrepareCallCFunction(3, 0, kScratchReg);                              \
       __ CallCFunction(ExternalReference::external(), 3, 0);                   \
-      __ PopCallerSaved(kDontSaveFPRegs, v0, v1);                              \
+      __ PopCallerSaved(SaveFPRegsMode::kIgnore, v0, v1);                      \
     }                                                                          \
   } while (0)
 
@@ -494,8 +492,8 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
     __ Ll(i.TempRegister(2), MemOperand(i.TempRegister(0), 0));                \
     __ ExtractBits(i.OutputRegister(0), i.TempRegister(2), i.TempRegister(1),  \
                    size, sign_extend);                                         \
-    __ ExtractBits(i.InputRegister(2), i.InputRegister(2), i.TempRegister(1),  \
-                   size, sign_extend);                                         \
+    __ ExtractBits(i.InputRegister(2), i.InputRegister(2), zero_reg, size,     \
+                   sign_extend);                                               \
     __ BranchShort(&exit, ne, i.InputRegister(2),                              \
                    Operand(i.OutputRegister(0)));                              \
     __ InsertBits(i.TempRegister(2), i.InputRegister(3), i.TempRegister(1),    \
@@ -746,7 +744,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchSaveCallerRegisters: {
       fp_mode_ =
           static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode()));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // kReturnRegister0 should have been saved before entering the stub.
       int bytes = __ PushCallerSaved(fp_mode_, kReturnRegister0);
       DCHECK(IsAligned(bytes, kSystemPointerSize));
@@ -759,7 +758,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchRestoreCallerRegisters: {
       DCHECK(fp_mode_ ==
              static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode())));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // Don't overwrite the returned value.
       int bytes = __ PopCallerSaved(fp_mode_, kReturnRegister0);
       frame_access_state()->IncreaseSPDelta(-(bytes / kSystemPointerSize));
@@ -781,7 +781,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       int offset = __ root_array_available() ? 68 : 80;
 #endif  // V8_ENABLE_WEBASSEMBLY
 #if V8_HOST_ARCH_MIPS
-      if (__ emit_debug_code()) {
+      if (FLAG_debug_code) {
         offset += 16;
       }
 #endif
@@ -873,9 +873,16 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchRet:
       AssembleReturn(instr->InputAt(0));
       break;
-    case kArchStackPointerGreaterThan:
-      // Pseudo-instruction used for cmp/branch. No opcode emitted here.
+    case kArchStackPointerGreaterThan: {
+      Register lhs_register = sp;
+      uint32_t offset;
+      if (ShouldApplyOffsetToStackCheck(instr, &offset)) {
+        lhs_register = i.TempRegister(1);
+        __ Subu(lhs_register, sp, offset);
+      }
+      __ Sltu(i.TempRegister(0), i.InputRegister(0), lhs_register);
       break;
+    }
     case kArchStackCheckOffset:
       __ Move(i.OutputRegister(), Smi::FromInt(GetStackCheckOffset()));
       break;
@@ -906,6 +913,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                                                    DetermineStubCallMode());
       __ Addu(kScratchReg, object, index);
       __ sw(value, MemOperand(kScratchReg));
+      if (mode > RecordWriteMode::kValueIsPointer) {
+        __ JumpIfSmi(value, ool->exit());
+      }
       __ CheckPageFlag(object, scratch0,
                        MemoryChunk::kPointersFromHereAreInterestingMask, ne,
                        ool->entry());
@@ -1922,10 +1932,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       } else {
         FrameScope scope(tasm(), StackFrame::MANUAL);
         __ Addu(a0, i.InputRegister(0), i.InputRegister(1));
-        __ PushCallerSaved(kDontSaveFPRegs, v0, v1);
+        __ PushCallerSaved(SaveFPRegsMode::kIgnore, v0, v1);
         __ PrepareCallCFunction(1, 0, kScratchReg);
         __ CallCFunction(ExternalReference::atomic_pair_load_function(), 1, 0);
-        __ PopCallerSaved(kDontSaveFPRegs, v0, v1);
+        __ PopCallerSaved(SaveFPRegsMode::kIgnore, v0, v1);
       }
       break;
     }
@@ -1945,10 +1955,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       } else {
         FrameScope scope(tasm(), StackFrame::MANUAL);
         __ Addu(a0, i.InputRegister(0), i.InputRegister(1));
-        __ PushCallerSaved(kDontSaveFPRegs);
+        __ PushCallerSaved(SaveFPRegsMode::kIgnore);
         __ PrepareCallCFunction(3, 0, kScratchReg);
         __ CallCFunction(ExternalReference::atomic_pair_store_function(), 3, 0);
-        __ PopCallerSaved(kDontSaveFPRegs);
+        __ PopCallerSaved(SaveFPRegsMode::kIgnore);
       }
       break;
     }
@@ -1986,12 +1996,12 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
         __ sync();
       } else {
         FrameScope scope(tasm(), StackFrame::MANUAL);
-        __ PushCallerSaved(kDontSaveFPRegs, v0, v1);
+        __ PushCallerSaved(SaveFPRegsMode::kIgnore, v0, v1);
         __ PrepareCallCFunction(3, 0, kScratchReg);
         __ Addu(a0, i.InputRegister(0), i.InputRegister(1));
         __ CallCFunction(ExternalReference::atomic_pair_exchange_function(), 3,
                          0);
-        __ PopCallerSaved(kDontSaveFPRegs, v0, v1);
+        __ PopCallerSaved(SaveFPRegsMode::kIgnore, v0, v1);
       }
       break;
     case kMipsWord32AtomicPairCompareExchange: {
@@ -2016,13 +2026,13 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
         __ sync();
       } else {
         FrameScope scope(tasm(), StackFrame::MANUAL);
-        __ PushCallerSaved(kDontSaveFPRegs, v0, v1);
+        __ PushCallerSaved(SaveFPRegsMode::kIgnore, v0, v1);
         __ PrepareCallCFunction(5, 0, kScratchReg);
         __ addu(a0, i.InputRegister(0), i.InputRegister(1));
         __ sw(i.InputRegister(5), MemOperand(sp, 16));
         __ CallCFunction(
             ExternalReference::atomic_pair_compare_exchange_function(), 5, 0);
-        __ PopCallerSaved(kDontSaveFPRegs, v0, v1);
+        __ PopCallerSaved(SaveFPRegsMode::kIgnore, v0, v1);
       }
       break;
     }
@@ -3652,7 +3662,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     }
   }
   return kSuccess;
-}  // NOLINT(readability/fn_size)
+}
 
 void AssembleBranchToLabels(CodeGenerator* gen, TurboAssembler* tasm,
                             Instruction* instr, FlagsCondition condition,
@@ -3704,13 +3714,11 @@ void AssembleBranchToLabels(CodeGenerator* gen, TurboAssembler* tasm,
     __ Branch(tlabel, cc, i.InputRegister(0), i.InputOperand(1));
   } else if (instr->arch_opcode() == kArchStackPointerGreaterThan) {
     cc = FlagsConditionToConditionCmp(condition);
-    Register lhs_register = sp;
-    uint32_t offset;
-    if (gen->ShouldApplyOffsetToStackCheck(instr, &offset)) {
-      lhs_register = i.TempRegister(0);
-      __ Subu(lhs_register, sp, offset);
+    DCHECK((cc == ls) || (cc == hi));
+    if (cc == ls) {
+      __ xori(i.TempRegister(0), i.TempRegister(0), 1);
     }
-    __ Branch(tlabel, cc, lhs_register, Operand(i.InputRegister(0)));
+    __ Branch(tlabel, ne, i.TempRegister(0), Operand(zero_reg));
   } else if (instr->arch_opcode() == kMipsCmpS ||
              instr->arch_opcode() == kMipsCmpD) {
     bool predicate;
@@ -4020,6 +4028,13 @@ void CodeGenerator::AssembleArchBoolean(Instruction* instr,
       }
     }
     return;
+  } else if (instr->arch_opcode() == kArchStackPointerGreaterThan) {
+    cc = FlagsConditionToConditionCmp(condition);
+    DCHECK((cc == ls) || (cc == hi));
+    if (cc == ls) {
+      __ xori(i.OutputRegister(), i.TempRegister(0), 1);
+    }
+    return;
   } else {
     PrintF("AssembleArchBoolean Unimplemented arch_opcode is : %d\n",
            instr->arch_opcode());
@@ -4132,7 +4147,7 @@ void CodeGenerator::AssembleConstructFrame() {
     // frame is still on the stack. Optimized code uses OSR values directly from
     // the unoptimized frame. Thus, all that needs to be done is to allocate the
     // remaining stack slots.
-    if (FLAG_code_comments) __ RecordComment("-- OSR entrypoint --");
+    __ RecordComment("-- OSR entrypoint --");
     osr_pc_offset_ = __ pc_offset();
     required_slots -= osr_helper()->UnoptimizedFrameSlots();
     ResetSpeculationPoison();
@@ -4234,7 +4249,7 @@ void CodeGenerator::AssembleReturn(InstructionOperand* additional_pop_count) {
   if (parameter_slots != 0) {
     if (additional_pop_count->IsImmediate()) {
       DCHECK_EQ(g.ToConstant(additional_pop_count).ToInt32(), 0);
-    } else if (__ emit_debug_code()) {
+    } else if (FLAG_debug_code) {
       __ Assert(eq, AbortReason::kUnexpectedAdditionalPopValue,
                 g.ToRegister(additional_pop_count),
                 Operand(static_cast<int64_t>(0)));
diff --git a/chromium/v8/src/compiler/backend/mips/instruction-scheduler-mips.cc b/chromium/v8/src/compiler/backend/mips/instruction-scheduler-mips.cc
index 0b8a022014e..48635c9c15b 100644
--- a/chromium/v8/src/compiler/backend/mips/instruction-scheduler-mips.cc
+++ b/chromium/v8/src/compiler/backend/mips/instruction-scheduler-mips.cc
@@ -1302,7 +1302,7 @@ int MultiPushFPULatency() {
 
 int PushCallerSavedLatency(SaveFPRegsMode fp_mode) {
   int latency = MultiPushLatency();
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     latency += MultiPushFPULatency();
   }
   return latency;
@@ -1326,7 +1326,7 @@ int MultiPopLatency() {
 
 int PopCallerSavedLatency(SaveFPRegsMode fp_mode) {
   int latency = 0;
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     latency += MultiPopFPULatency();
   }
   return latency + MultiPopLatency();
diff --git a/chromium/v8/src/compiler/backend/mips/instruction-selector-mips.cc b/chromium/v8/src/compiler/backend/mips/instruction-selector-mips.cc
index dcea4c85660..b001578b888 100644
--- a/chromium/v8/src/compiler/backend/mips/instruction-selector-mips.cc
+++ b/chromium/v8/src/compiler/backend/mips/instruction-selector-mips.cc
@@ -372,6 +372,7 @@ void InstructionSelector::VisitLoad(Node* node) {
     case MachineRepresentation::kCompressedPointer:  // Fall through.
     case MachineRepresentation::kCompressed:         // Fall through.
     case MachineRepresentation::kWord64:             // Fall through.
+    case MachineRepresentation::kMapWord:            // Fall through.
     case MachineRepresentation::kNone:
       UNREACHABLE();
   }
@@ -457,6 +458,7 @@ void InstructionSelector::VisitStore(Node* node) {
       case MachineRepresentation::kCompressedPointer:  // Fall through.
       case MachineRepresentation::kCompressed:         // Fall through.
       case MachineRepresentation::kWord64:             // Fall through.
+      case MachineRepresentation::kMapWord:            // Fall through.
       case MachineRepresentation::kNone:
         UNREACHABLE();
     }
@@ -1432,6 +1434,7 @@ void InstructionSelector::VisitUnalignedLoad(Node* node) {
     case MachineRepresentation::kCompressedPointer:  // Fall through.
     case MachineRepresentation::kCompressed:         // Fall through.
     case MachineRepresentation::kWord64:             // Fall through.
+    case MachineRepresentation::kMapWord:            // Fall through.
     case MachineRepresentation::kNone:
       UNREACHABLE();
   }
@@ -1485,6 +1488,7 @@ void InstructionSelector::VisitUnalignedStore(Node* node) {
     case MachineRepresentation::kCompressedPointer:  // Fall through.
     case MachineRepresentation::kCompressed:         // Fall through.
     case MachineRepresentation::kWord64:             // Fall through.
+    case MachineRepresentation::kMapWord:            // Fall through.
     case MachineRepresentation::kNone:
       UNREACHABLE();
   }
@@ -1630,11 +1634,12 @@ void InstructionSelector::VisitStackPointerGreaterThan(
   InstructionOperand* const outputs = nullptr;
   const int output_count = 0;
 
+  // TempRegister(0) is used to store the comparison result.
   // Applying an offset to this stack check requires a temp register. Offsets
   // are only applied to the first stack check. If applying an offset, we must
   // ensure the input and temp registers do not alias, thus kUniqueRegister.
-  InstructionOperand temps[] = {g.TempRegister()};
-  const int temp_count = (kind == StackCheckKind::kJSFunctionEntry ? 1 : 0);
+  InstructionOperand temps[] = {g.TempRegister(), g.TempRegister()};
+  const int temp_count = (kind == StackCheckKind::kJSFunctionEntry ? 2 : 1);
   const auto register_mode = (kind == StackCheckKind::kJSFunctionEntry)
                                  ? OperandGenerator::kUniqueRegister
                                  : OperandGenerator::kRegister;
@@ -2500,6 +2505,12 @@ void InstructionSelector::VisitF64x2Pmax(Node* node) {
   VisitUniqueRRR(this, kMipsF64x2Pmax, node);
 }
 
+void InstructionSelector::AddOutputToSelectContinuation(OperandGenerator* g,
+                                                        int first_input_index,
+                                                        Node* node) {
+  UNREACHABLE();
+}
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
diff --git a/chromium/v8/src/compiler/backend/mips64/code-generator-mips64.cc b/chromium/v8/src/compiler/backend/mips64/code-generator-mips64.cc
index 6edb1539439..257ef1bca15 100644
--- a/chromium/v8/src/compiler/backend/mips64/code-generator-mips64.cc
+++ b/chromium/v8/src/compiler/backend/mips64/code-generator-mips64.cc
@@ -163,18 +163,16 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
   }
 
   void Generate() final {
-    if (mode_ > RecordWriteMode::kValueIsPointer) {
-      __ JumpIfSmi(value_, exit());
-    }
     __ CheckPageFlag(value_, scratch0_,
                      MemoryChunk::kPointersToHereAreInterestingMask, eq,
                      exit());
     __ Daddu(scratch1_, object_, index_);
     RememberedSetAction const remembered_set_action =
-        mode_ > RecordWriteMode::kValueIsMap ? EMIT_REMEMBERED_SET
-                                             : OMIT_REMEMBERED_SET;
-    SaveFPRegsMode const save_fp_mode =
-        frame()->DidAllocateDoubleRegisters() ? kSaveFPRegs : kDontSaveFPRegs;
+        mode_ > RecordWriteMode::kValueIsMap ? RememberedSetAction::kEmit
+                                             : RememberedSetAction::kOmit;
+    SaveFPRegsMode const save_fp_mode = frame()->DidAllocateDoubleRegisters()
+                                            ? SaveFPRegsMode::kSave
+                                            : SaveFPRegsMode::kIgnore;
     if (must_save_lr_) {
       // We need to save and restore ra if the frame was elided.
       __ Push(ra);
@@ -465,8 +463,8 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
     __ load_linked(i.TempRegister(2), MemOperand(i.TempRegister(0), 0));       \
     __ ExtractBits(i.OutputRegister(0), i.TempRegister(2), i.TempRegister(1),  \
                    size, sign_extend);                                         \
-    __ ExtractBits(i.InputRegister(2), i.InputRegister(2), i.TempRegister(1),  \
-                   size, sign_extend);                                         \
+    __ ExtractBits(i.InputRegister(2), i.InputRegister(2), zero_reg, size,     \
+                   sign_extend);                                               \
     __ BranchShort(&exit, ne, i.InputRegister(2),                              \
                    Operand(i.OutputRegister(0)));                              \
     __ InsertBits(i.TempRegister(2), i.InputRegister(3), i.TempRegister(1),    \
@@ -711,7 +709,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchSaveCallerRegisters: {
       fp_mode_ =
           static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode()));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // kReturnRegister0 should have been saved before entering the stub.
       int bytes = __ PushCallerSaved(fp_mode_, kReturnRegister0);
       DCHECK(IsAligned(bytes, kSystemPointerSize));
@@ -724,7 +723,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchRestoreCallerRegisters: {
       DCHECK(fp_mode_ ==
              static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode())));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // Don't overwrite the returned value.
       int bytes = __ PopCallerSaved(fp_mode_, kReturnRegister0);
       frame_access_state()->IncreaseSPDelta(-(bytes / kSystemPointerSize));
@@ -746,7 +746,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       int offset = __ root_array_available() ? 76 : 88;
 #endif  // V8_ENABLE_WEBASSEMBLY
 #if V8_HOST_ARCH_MIPS64
-      if (__ emit_debug_code()) {
+      if (FLAG_debug_code) {
         offset += 16;
       }
 #endif
@@ -835,9 +835,16 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchRet:
       AssembleReturn(instr->InputAt(0));
       break;
-    case kArchStackPointerGreaterThan:
-      // Pseudo-instruction used for cmp/branch. No opcode emitted here.
+    case kArchStackPointerGreaterThan: {
+      Register lhs_register = sp;
+      uint32_t offset;
+      if (ShouldApplyOffsetToStackCheck(instr, &offset)) {
+        lhs_register = i.TempRegister(1);
+        __ Dsubu(lhs_register, sp, offset);
+      }
+      __ Sltu(i.TempRegister(0), i.InputRegister(0), lhs_register);
       break;
+    }
     case kArchStackCheckOffset:
       __ Move(i.OutputRegister(), Smi::FromInt(GetStackCheckOffset()));
       break;
@@ -868,6 +875,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                                                    DetermineStubCallMode());
       __ Daddu(kScratchReg, object, index);
       __ Sd(value, MemOperand(kScratchReg));
+      if (mode > RecordWriteMode::kValueIsPointer) {
+        __ JumpIfSmi(value, ool->exit());
+      }
       __ CheckPageFlag(object, scratch0,
                        MemoryChunk::kPointersFromHereAreInterestingMask, ne,
                        ool->entry());
@@ -3817,7 +3827,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     }
   }
   return kSuccess;
-}  // NOLINT(readability/fn_size)
+}
 
 #define UNSUPPORTED_COND(opcode, condition)                                    \
   StdoutStream{} << "Unsupported " << #opcode << " condition: \"" << condition \
@@ -3880,13 +3890,11 @@ void AssembleBranchToLabels(CodeGenerator* gen, TurboAssembler* tasm,
     __ Branch(tlabel, cc, i.InputRegister(0), i.InputOperand(1));
   } else if (instr->arch_opcode() == kArchStackPointerGreaterThan) {
     cc = FlagsConditionToConditionCmp(condition);
-    Register lhs_register = sp;
-    uint32_t offset;
-    if (gen->ShouldApplyOffsetToStackCheck(instr, &offset)) {
-      lhs_register = i.TempRegister(0);
-      __ Dsubu(lhs_register, sp, offset);
+    DCHECK((cc == ls) || (cc == hi));
+    if (cc == ls) {
+      __ xori(i.TempRegister(0), i.TempRegister(0), 1);
     }
-    __ Branch(tlabel, cc, lhs_register, Operand(i.InputRegister(0)));
+    __ Branch(tlabel, ne, i.TempRegister(0), Operand(zero_reg));
   } else if (instr->arch_opcode() == kMips64CmpS ||
              instr->arch_opcode() == kMips64CmpD) {
     bool predicate;
@@ -4232,6 +4240,13 @@ void CodeGenerator::AssembleArchBoolean(Instruction* instr,
       }
     }
     return;
+  } else if (instr->arch_opcode() == kArchStackPointerGreaterThan) {
+    cc = FlagsConditionToConditionCmp(condition);
+    DCHECK((cc == ls) || (cc == hi));
+    if (cc == ls) {
+      __ xori(i.OutputRegister(), i.TempRegister(0), 1);
+    }
+    return;
   } else {
     PrintF("AssembleArchBranch Unimplemented arch_opcode is : %d\n",
            instr->arch_opcode());
@@ -4342,7 +4357,7 @@ void CodeGenerator::AssembleConstructFrame() {
     // frame is still on the stack. Optimized code uses OSR values directly from
     // the unoptimized frame. Thus, all that needs to be done is to allocate the
     // remaining stack slots.
-    if (FLAG_code_comments) __ RecordComment("-- OSR entrypoint --");
+    __ RecordComment("-- OSR entrypoint --");
     osr_pc_offset_ = __ pc_offset();
     required_slots -= osr_helper()->UnoptimizedFrameSlots();
     ResetSpeculationPoison();
@@ -4446,7 +4461,7 @@ void CodeGenerator::AssembleReturn(InstructionOperand* additional_pop_count) {
   if (parameter_slots != 0) {
     if (additional_pop_count->IsImmediate()) {
       DCHECK_EQ(g.ToConstant(additional_pop_count).ToInt32(), 0);
-    } else if (__ emit_debug_code()) {
+    } else if (FLAG_debug_code) {
       __ Assert(eq, AbortReason::kUnexpectedAdditionalPopValue,
                 g.ToRegister(additional_pop_count),
                 Operand(static_cast<int64_t>(0)));
diff --git a/chromium/v8/src/compiler/backend/mips64/instruction-scheduler-mips64.cc b/chromium/v8/src/compiler/backend/mips64/instruction-scheduler-mips64.cc
index 3b0e5b85fb4..c63e0aa3d36 100644
--- a/chromium/v8/src/compiler/backend/mips64/instruction-scheduler-mips64.cc
+++ b/chromium/v8/src/compiler/backend/mips64/instruction-scheduler-mips64.cc
@@ -932,7 +932,7 @@ int MultiPushFPULatency() {
 
 int PushCallerSavedLatency(SaveFPRegsMode fp_mode) {
   int latency = MultiPushLatency();
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     latency += MultiPushFPULatency();
   }
   return latency;
@@ -956,7 +956,7 @@ int MultiPopFPULatency() {
 
 int PopCallerSavedLatency(SaveFPRegsMode fp_mode) {
   int latency = MultiPopLatency();
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     latency += MultiPopFPULatency();
   }
   return latency;
diff --git a/chromium/v8/src/compiler/backend/mips64/instruction-selector-mips64.cc b/chromium/v8/src/compiler/backend/mips64/instruction-selector-mips64.cc
index b0b3fec8f38..6d6b487ccdd 100644
--- a/chromium/v8/src/compiler/backend/mips64/instruction-selector-mips64.cc
+++ b/chromium/v8/src/compiler/backend/mips64/instruction-selector-mips64.cc
@@ -512,6 +512,7 @@ void InstructionSelector::VisitLoad(Node* node) {
       break;
     case MachineRepresentation::kCompressedPointer:  // Fall through.
     case MachineRepresentation::kCompressed:         // Fall through.
+    case MachineRepresentation::kMapWord:            // Fall through.
     case MachineRepresentation::kNone:
       UNREACHABLE();
   }
@@ -589,6 +590,7 @@ void InstructionSelector::VisitStore(Node* node) {
         break;
       case MachineRepresentation::kCompressedPointer:  // Fall through.
       case MachineRepresentation::kCompressed:         // Fall through.
+      case MachineRepresentation::kMapWord:            // Fall through.
       case MachineRepresentation::kNone:
         UNREACHABLE();
     }
@@ -1452,7 +1454,9 @@ void InstructionSelector::VisitBitcastWord32ToWord64(Node* node) {
 
 void InstructionSelector::VisitChangeInt32ToInt64(Node* node) {
   Node* value = node->InputAt(0);
-  if (value->opcode() == IrOpcode::kLoad && CanCover(node, value)) {
+  if ((value->opcode() == IrOpcode::kLoad ||
+       value->opcode() == IrOpcode::kLoadImmutable) &&
+      CanCover(node, value)) {
     // Generate sign-extending load.
     LoadRepresentation load_rep = LoadRepresentationOf(value->op());
     InstructionCode opcode = kArchNop;
@@ -1853,6 +1857,7 @@ void InstructionSelector::VisitUnalignedLoad(Node* node) {
     case MachineRepresentation::kBit:                // Fall through.
     case MachineRepresentation::kCompressedPointer:  // Fall through.
     case MachineRepresentation::kCompressed:         // Fall through.
+    case MachineRepresentation::kMapWord:            // Fall through.
     case MachineRepresentation::kNone:
       UNREACHABLE();
   }
@@ -1906,6 +1911,7 @@ void InstructionSelector::VisitUnalignedStore(Node* node) {
     case MachineRepresentation::kBit:                // Fall through.
     case MachineRepresentation::kCompressedPointer:  // Fall through.
     case MachineRepresentation::kCompressed:         // Fall through.
+    case MachineRepresentation::kMapWord:            // Fall through.
     case MachineRepresentation::kNone:
       UNREACHABLE();
   }
@@ -2265,11 +2271,12 @@ void InstructionSelector::VisitStackPointerGreaterThan(
   InstructionOperand* const outputs = nullptr;
   const int output_count = 0;
 
+  // TempRegister(0) is used to store the comparison result.
   // Applying an offset to this stack check requires a temp register. Offsets
   // are only applied to the first stack check. If applying an offset, we must
   // ensure the input and temp registers do not alias, thus kUniqueRegister.
-  InstructionOperand temps[] = {g.TempRegister()};
-  const int temp_count = (kind == StackCheckKind::kJSFunctionEntry ? 1 : 0);
+  InstructionOperand temps[] = {g.TempRegister(), g.TempRegister()};
+  const int temp_count = (kind == StackCheckKind::kJSFunctionEntry ? 2 : 1);
   const auto register_mode = (kind == StackCheckKind::kJSFunctionEntry)
                                  ? OperandGenerator::kUniqueRegister
                                  : OperandGenerator::kRegister;
@@ -3291,6 +3298,12 @@ VISIT_EXTADD_PAIRWISE(I32x4ExtAddPairwiseI16x8S, MSAS16)
 VISIT_EXTADD_PAIRWISE(I32x4ExtAddPairwiseI16x8U, MSAU16)
 #undef VISIT_EXTADD_PAIRWISE
 
+void InstructionSelector::AddOutputToSelectContinuation(OperandGenerator* g,
+                                                        int first_input_index,
+                                                        Node* node) {
+  UNREACHABLE();
+}
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
diff --git a/chromium/v8/src/compiler/backend/ppc/OWNERS b/chromium/v8/src/compiler/backend/ppc/OWNERS
deleted file mode 100644
index 02c2cd757c9..00000000000
--- a/chromium/v8/src/compiler/backend/ppc/OWNERS
+++ /dev/null
@@ -1,5 +0,0 @@
-junyan@redhat.com
-joransiu@ca.ibm.com
-midawson@redhat.com
-mfarazma@redhat.com
-vasili.skurydzin@ibm.com
diff --git a/chromium/v8/src/compiler/backend/ppc/code-generator-ppc.cc b/chromium/v8/src/compiler/backend/ppc/code-generator-ppc.cc
index 334d318f02e..2dfae5d2d6a 100644
--- a/chromium/v8/src/compiler/backend/ppc/code-generator-ppc.cc
+++ b/chromium/v8/src/compiler/backend/ppc/code-generator-ppc.cc
@@ -171,9 +171,6 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
 
   void Generate() final {
     ConstantPoolUnavailableScope constant_pool_unavailable(tasm());
-    if (mode_ > RecordWriteMode::kValueIsPointer) {
-      __ JumpIfSmi(value_, exit());
-    }
     if (COMPRESS_POINTERS_BOOL) {
       __ DecompressTaggedPointer(value_, value_);
     }
@@ -187,10 +184,11 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
       __ add(scratch1_, object_, offset_);
     }
     RememberedSetAction const remembered_set_action =
-        mode_ > RecordWriteMode::kValueIsMap ? EMIT_REMEMBERED_SET
-                                             : OMIT_REMEMBERED_SET;
-    SaveFPRegsMode const save_fp_mode =
-        frame()->DidAllocateDoubleRegisters() ? kSaveFPRegs : kDontSaveFPRegs;
+        mode_ > RecordWriteMode::kValueIsMap ? RememberedSetAction::kEmit
+                                             : RememberedSetAction::kOmit;
+    SaveFPRegsMode const save_fp_mode = frame()->DidAllocateDoubleRegisters()
+                                            ? SaveFPRegsMode::kSave
+                                            : SaveFPRegsMode::kIgnore;
     if (must_save_lr_) {
       // We need to save and restore lr if the frame was elided.
       __ mflr(scratch0_);
@@ -824,8 +822,8 @@ void CodeGenerator::BailoutIfDeoptimized() {
   int offset = Code::kCodeDataContainerOffset - Code::kHeaderSize;
   __ LoadTaggedPointerField(
       r11, MemOperand(kJavaScriptCallCodeStartRegister, offset));
-  __ LoadWordArith(
-      r11, FieldMemOperand(r11, CodeDataContainer::kKindSpecificFlagsOffset));
+  __ LoadS32(r11,
+             FieldMemOperand(r11, CodeDataContainer::kKindSpecificFlagsOffset));
   __ TestBit(r11, Code::kMarkedForDeoptimizationBit);
   __ Jump(BUILTIN_CODE(isolate(), CompileLazyDeoptimizedCode),
           RelocInfo::CODE_TARGET, ne, cr0);
@@ -981,7 +979,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchSaveCallerRegisters: {
       fp_mode_ =
           static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode()));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // kReturnRegister0 should have been saved before entering the stub.
       int bytes = __ PushCallerSaved(fp_mode_, kReturnRegister0);
       DCHECK(IsAligned(bytes, kSystemPointerSize));
@@ -994,7 +993,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchRestoreCallerRegisters: {
       DCHECK(fp_mode_ ==
              static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode())));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // Don't overwrite the returned value.
       int bytes = __ PopCallerSaved(fp_mode_, kReturnRegister0);
       frame_access_state()->IncreaseSPDelta(-(bytes / kSystemPointerSize));
@@ -1130,7 +1130,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     case kArchParentFramePointer:
       if (frame_access_state()->has_frame()) {
-        __ LoadP(i.OutputRegister(), MemOperand(fp, 0));
+        __ LoadU64(i.OutputRegister(), MemOperand(fp, 0));
       } else {
         __ mr(i.OutputRegister(), fp);
       }
@@ -1192,6 +1192,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
             DetermineStubCallMode(), &unwinding_info_writer_);
         __ StoreTaggedFieldX(value, MemOperand(object, offset), r0);
       }
+      if (mode > RecordWriteMode::kValueIsPointer) {
+        __ JumpIfSmi(value, ool->exit());
+      }
       __ CheckPageFlag(object, scratch0,
                        MemoryChunk::kPointersFromHereAreInterestingMask, ne,
                        ool->entry());
@@ -1222,11 +1225,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
         } else {
           DCHECK_EQ(MachineRepresentation::kSimd128, op->representation());
           __ mov(ip, Operand(offset));
-          __ LoadSimd128(i.OutputSimd128Register(), MemOperand(fp, ip), r0,
-                         kScratchSimd128Reg);
+          __ LoadSimd128(i.OutputSimd128Register(), MemOperand(fp, ip));
         }
       } else {
-        __ LoadP(i.OutputRegister(), MemOperand(fp, offset), r0);
+        __ LoadU64(i.OutputRegister(), MemOperand(fp, offset), r0);
       }
       break;
     }
@@ -1748,8 +1750,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
           break;
         case MachineRepresentation::kSimd128:
           __ addi(sp, sp, Operand(-kSimd128Size));
-          __ StoreSimd128(i.InputSimd128Register(1), MemOperand(r0, sp), r0,
-                          kScratchSimd128Reg);
+          __ StoreSimd128(i.InputSimd128Register(1), MemOperand(r0, sp));
           break;
         default:
           __ StorePU(i.InputRegister(1), MemOperand(sp, -kSystemPointerSize),
@@ -1791,8 +1792,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
         } else {
           DCHECK_EQ(MachineRepresentation::kSimd128, op->representation());
           __ mov(ip, Operand(slot * kSystemPointerSize));
-          __ StoreSimd128(i.InputSimd128Register(0), MemOperand(ip, sp), r0,
-                          kScratchSimd128Reg);
+          __ StoreSimd128(i.InputSimd128Register(0), MemOperand(ip, sp));
         }
       } else {
         __ StoreP(i.InputRegister(0), MemOperand(sp, slot * kSystemPointerSize),
@@ -2057,9 +2057,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       AddressingMode mode = kMode_None;
       MemOperand operand = i.MemoryOperand(&mode);
       bool is_atomic = i.InputInt32(2);
-      // lvx only supports MRR.
       DCHECK_EQ(mode, kMode_MRR);
-      __ LoadSimd128(result, operand, r0, kScratchSimd128Reg);
+      __ LoadSimd128(result, operand);
       if (is_atomic) __ lwsync();
       DCHECK_EQ(LeaveRC, i.OutputRCBit());
       break;
@@ -2095,9 +2094,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       Simd128Register value = i.InputSimd128Register(index);
       bool is_atomic = i.InputInt32(3);
       if (is_atomic) __ lwsync();
-      // stvx only supports MRR.
       DCHECK_EQ(mode, kMode_MRR);
-      __ StoreSimd128(value, operand, r0, kScratchSimd128Reg);
+      __ StoreSimd128(value, operand);
       if (is_atomic) __ sync();
       DCHECK_EQ(LeaveRC, i.OutputRCBit());
       break;
@@ -2479,21 +2477,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                  i.InputSimd128Register(1));
       break;
     }
-    case kPPC_I64x2MinS: {
-      __ vminsd(i.OutputSimd128Register(), i.InputSimd128Register(0),
-                i.InputSimd128Register(1));
-      break;
-    }
     case kPPC_I32x4MinS: {
       __ vminsw(i.OutputSimd128Register(), i.InputSimd128Register(0),
                 i.InputSimd128Register(1));
       break;
     }
-    case kPPC_I64x2MinU: {
-      __ vminud(i.OutputSimd128Register(), i.InputSimd128Register(0),
-                i.InputSimd128Register(1));
-      break;
-    }
     case kPPC_I32x4MinU: {
       __ vminuw(i.OutputSimd128Register(), i.InputSimd128Register(0),
                 i.InputSimd128Register(1));
@@ -2519,21 +2507,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                 i.InputSimd128Register(1));
       break;
     }
-    case kPPC_I64x2MaxS: {
-      __ vmaxsd(i.OutputSimd128Register(), i.InputSimd128Register(0),
-                i.InputSimd128Register(1));
-      break;
-    }
     case kPPC_I32x4MaxS: {
       __ vmaxsw(i.OutputSimd128Register(), i.InputSimd128Register(0),
                 i.InputSimd128Register(1));
       break;
     }
-    case kPPC_I64x2MaxU: {
-      __ vmaxud(i.OutputSimd128Register(), i.InputSimd128Register(0),
-                i.InputSimd128Register(1));
-      break;
-    }
     case kPPC_I32x4MaxU: {
       __ vmaxuw(i.OutputSimd128Register(), i.InputSimd128Register(0),
                 i.InputSimd128Register(1));
@@ -2662,26 +2640,17 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kPPC_I64x2GeS: {
-      __ vcmpequd(kScratchSimd128Reg, i.InputSimd128Register(0),
-                  i.InputSimd128Register(1));
-      __ vcmpgtsd(i.OutputSimd128Register(), i.InputSimd128Register(0),
-                  i.InputSimd128Register(1));
-      __ vor(i.OutputSimd128Register(), i.OutputSimd128Register(),
-             kScratchSimd128Reg);
+      __ vcmpgtsd(kScratchSimd128Reg, i.InputSimd128Register(1),
+                  i.InputSimd128Register(0));
+      __ vnor(i.OutputSimd128Register(), kScratchSimd128Reg,
+              kScratchSimd128Reg);
       break;
     }
     case kPPC_I32x4GeS: {
-      __ vcmpequw(kScratchSimd128Reg, i.InputSimd128Register(0),
-                  i.InputSimd128Register(1));
-      __ vcmpgtsw(i.OutputSimd128Register(), i.InputSimd128Register(0),
-                  i.InputSimd128Register(1));
-      __ vor(i.OutputSimd128Register(), i.OutputSimd128Register(),
-             kScratchSimd128Reg);
-      break;
-    }
-    case kPPC_I64x2GtU: {
-      __ vcmpgtud(i.OutputSimd128Register(), i.InputSimd128Register(0),
-                  i.InputSimd128Register(1));
+      __ vcmpgtsw(kScratchSimd128Reg, i.InputSimd128Register(1),
+                  i.InputSimd128Register(0));
+      __ vnor(i.OutputSimd128Register(), kScratchSimd128Reg,
+              kScratchSimd128Reg);
       break;
     }
     case kPPC_I32x4GtU: {
@@ -2690,16 +2659,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
 
       break;
     }
-    case kPPC_I64x2GeU: {
-      __ vcmpequd(kScratchSimd128Reg, i.InputSimd128Register(0),
-                  i.InputSimd128Register(1));
-      __ vcmpgtud(i.OutputSimd128Register(), i.InputSimd128Register(0),
-                  i.InputSimd128Register(1));
-      __ vor(i.OutputSimd128Register(), i.OutputSimd128Register(),
-             kScratchSimd128Reg);
-
-      break;
-    }
     case kPPC_I32x4GeU: {
       __ vcmpequw(kScratchSimd128Reg, i.InputSimd128Register(0),
                   i.InputSimd128Register(1));
@@ -2715,12 +2674,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kPPC_I16x8GeS: {
-      __ vcmpequh(kScratchSimd128Reg, i.InputSimd128Register(0),
-                  i.InputSimd128Register(1));
-      __ vcmpgtsh(i.OutputSimd128Register(), i.InputSimd128Register(0),
-                  i.InputSimd128Register(1));
-      __ vor(i.OutputSimd128Register(), i.OutputSimd128Register(),
-             kScratchSimd128Reg);
+      __ vcmpgtsh(kScratchSimd128Reg, i.InputSimd128Register(1),
+                  i.InputSimd128Register(0));
+      __ vnor(i.OutputSimd128Register(), kScratchSimd128Reg,
+              kScratchSimd128Reg);
       break;
     }
     case kPPC_I16x8GtU: {
@@ -2743,12 +2700,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kPPC_I8x16GeS: {
-      __ vcmpequb(kScratchSimd128Reg, i.InputSimd128Register(0),
-                  i.InputSimd128Register(1));
-      __ vcmpgtsb(i.OutputSimd128Register(), i.InputSimd128Register(0),
-                  i.InputSimd128Register(1));
-      __ vor(i.OutputSimd128Register(), i.OutputSimd128Register(),
-             kScratchSimd128Reg);
+      __ vcmpgtsb(kScratchSimd128Reg, i.InputSimd128Register(1),
+                  i.InputSimd128Register(0));
+      __ vnor(i.OutputSimd128Register(), kScratchSimd128Reg,
+              kScratchSimd128Reg);
       break;
     }
     case kPPC_I8x16GtU: {
@@ -2840,15 +2795,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kPPC_S128Const: {
-      Simd128Register dst = i.OutputSimd128Register();
-      constexpr int lane_width_in_bytes = 8;
       uint64_t low = make_uint64(i.InputUint32(1), i.InputUint32(0));
       uint64_t high = make_uint64(i.InputUint32(3), i.InputUint32(2));
       __ mov(r0, Operand(low));
       __ mov(ip, Operand(high));
-      __ mtvsrd(dst, ip);
-      __ mtvsrd(kScratchSimd128Reg, r0);
-      __ vinsertd(dst, kScratchSimd128Reg, Operand(1 * lane_width_in_bytes));
+      __ mtvsrdd(i.OutputSimd128Register(), ip, r0);
       break;
     }
     case kPPC_S128Zero: {
@@ -2908,24 +2859,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kPPC_I64x2Neg: {
-      constexpr int lane_width_in_bytes = 8;
-      Simd128Register tempFPReg1 = i.ToSimd128Register(instr->TempAt(0));
-      __ li(kScratchReg, Operand(1));
-      __ mtvsrd(kScratchSimd128Reg, kScratchReg);
-      __ vinsertd(kScratchSimd128Reg, kScratchSimd128Reg,
-                  Operand(1 * lane_width_in_bytes));
-      // Perform negation.
-      __ vnor(tempFPReg1, i.InputSimd128Register(0), i.InputSimd128Register(0));
-      __ vaddudm(i.OutputSimd128Register(), tempFPReg1, kScratchSimd128Reg);
+      __ vnegd(i.OutputSimd128Register(), i.InputSimd128Register(0));
       break;
     }
     case kPPC_I32x4Neg: {
-      Simd128Register tempFPReg1 = i.ToSimd128Register(instr->TempAt(0));
-      __ li(ip, Operand(1));
-      __ mtvsrd(kScratchSimd128Reg, ip);
-      __ vspltw(kScratchSimd128Reg, kScratchSimd128Reg, Operand(1));
-      __ vnor(tempFPReg1, i.InputSimd128Register(0), i.InputSimd128Register(0));
-      __ vadduwm(i.OutputSimd128Register(), kScratchSimd128Reg, tempFPReg1);
+      __ vnegw(i.OutputSimd128Register(), i.InputSimd128Register(0));
       break;
     }
     case kPPC_I64x2Abs: {
@@ -3170,15 +3108,14 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kPPC_I8x16Shuffle: {
-      constexpr int lane_width_in_bytes = 8;
       Simd128Register dst = i.OutputSimd128Register(),
                       src0 = i.InputSimd128Register(0),
                       src1 = i.InputSimd128Register(1);
-      __ mov(r0, Operand(make_uint64(i.InputUint32(3), i.InputUint32(2))));
-      __ mov(ip, Operand(make_uint64(i.InputUint32(5), i.InputUint32(4))));
-      __ mtvsrd(kScratchSimd128Reg, r0);
-      __ mtvsrd(dst, ip);
-      __ vinsertd(dst, kScratchSimd128Reg, Operand(1 * lane_width_in_bytes));
+      uint64_t low = make_uint64(i.InputUint32(3), i.InputUint32(2));
+      uint64_t high = make_uint64(i.InputUint32(5), i.InputUint32(4));
+      __ mov(r0, Operand(low));
+      __ mov(ip, Operand(high));
+      __ mtvsrdd(dst, ip, r0);
       __ vperm(dst, src0, src1, dst);
       break;
     }
@@ -3226,24 +3163,15 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       Simd128Register dst = i.OutputSimd128Register(),
                       src0 = i.InputSimd128Register(0),
                       src1 = i.InputSimd128Register(1),
-                      tempFPReg1 = i.ToSimd128Register(instr->TempAt(0)),
-                      tempFPReg2 = i.ToSimd128Register(instr->TempAt(1));
+                      tempFPReg1 = i.ToSimd128Register(instr->TempAt(0));
       // Saturate the indices to 5 bits. Input indices more than 31 should
       // return 0.
-      __ xxspltib(tempFPReg2, Operand(31));
-      __ vminub(tempFPReg2, src1, tempFPReg2);
-      __ addi(sp, sp, Operand(-16));
-      __ stxvd(src0, MemOperand(r0, sp));
-      __ ldbrx(r0, MemOperand(r0, sp));
-      __ li(ip, Operand(8));
-      __ ldbrx(ip, MemOperand(ip, sp));
-      __ stdx(ip, MemOperand(r0, sp));
-      __ li(ip, Operand(8));
-      __ stdx(r0, MemOperand(ip, sp));
-      __ lxvd(kScratchSimd128Reg, MemOperand(r0, sp));
-      __ addi(sp, sp, Operand(16));
-      __ vxor(tempFPReg1, tempFPReg1, tempFPReg1);
-      __ vperm(dst, kScratchSimd128Reg, tempFPReg1, tempFPReg2);
+      __ xxspltib(tempFPReg1, Operand(31));
+      __ vminub(tempFPReg1, src1, tempFPReg1);
+      //  input needs to be reversed.
+      __ xxbrq(dst, src0);
+      __ vxor(kScratchSimd128Reg, kScratchSimd128Reg, kScratchSimd128Reg);
+      __ vperm(dst, dst, kScratchSimd128Reg, tempFPReg1);
       break;
     }
     case kPPC_F64x2Qfma: {
@@ -3871,7 +3799,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       UNREACHABLE();
   }
   return kSuccess;
-}  // NOLINT(readability/fn_size)
+}
 
 // Assembles branches after an instruction.
 void CodeGenerator::AssembleArchBranch(Instruction* instr, BranchInfo* branch) {
@@ -4174,7 +4102,7 @@ void CodeGenerator::AssembleConstructFrame() {
     // frame is still on the stack. Optimized code uses OSR values directly from
     // the unoptimized frame. Thus, all that needs to be done is to allocate the
     // remaining stack slots.
-    if (FLAG_code_comments) __ RecordComment("-- OSR entrypoint --");
+    __ RecordComment("-- OSR entrypoint --");
     osr_pc_offset_ = __ pc_offset();
     required_slots -= osr_helper()->UnoptimizedFrameSlots();
     ResetSpeculationPoison();
@@ -4200,11 +4128,11 @@ void CodeGenerator::AssembleConstructFrame() {
       // check in the condition code.
       if ((required_slots * kSystemPointerSize) < (FLAG_stack_size * 1024)) {
         Register scratch = ip;
-        __ LoadP(
+        __ LoadU64(
             scratch,
             FieldMemOperand(kWasmInstanceRegister,
                             WasmInstanceObject::kRealStackLimitAddressOffset));
-        __ LoadP(scratch, MemOperand(scratch), r0);
+        __ LoadU64(scratch, MemOperand(scratch), r0);
         __ Add(scratch, scratch, required_slots * kSystemPointerSize, r0);
         __ cmpl(sp, scratch);
         __ bge(&done);
@@ -4284,7 +4212,7 @@ void CodeGenerator::AssembleReturn(InstructionOperand* additional_pop_count) {
   if (parameter_slots != 0) {
     if (additional_pop_count->IsImmediate()) {
       DCHECK_EQ(g.ToConstant(additional_pop_count).ToInt32(), 0);
-    } else if (__ emit_debug_code()) {
+    } else if (FLAG_debug_code) {
       __ cmpi(g.ToRegister(additional_pop_count), Operand(0));
       __ Assert(eq, AbortReason::kUnexpectedAdditionalPopValue);
     }
@@ -4315,7 +4243,7 @@ void CodeGenerator::AssembleReturn(InstructionOperand* additional_pop_count) {
     }
     if (drop_jsargs) {
       // Get the actual argument count.
-      __ LoadP(argc_reg, MemOperand(fp, StandardFrameConstants::kArgCOffset));
+      __ LoadU64(argc_reg, MemOperand(fp, StandardFrameConstants::kArgCOffset));
     }
     AssembleDeconstructFrame();
   }
@@ -4327,7 +4255,7 @@ void CodeGenerator::AssembleReturn(InstructionOperand* additional_pop_count) {
     __ addi(argc_reg, argc_reg, Operand(1));  // Also pop the receiver.
     if (parameter_slots > 1) {
       Label skip;
-      __ cmpi(argc_reg, Operand(parameter_slots));
+      __ Cmpi(argc_reg, Operand(parameter_slots), r0);
       __ bgt(&skip);
       __ mov(argc_reg, Operand(parameter_slots));
       __ bind(&skip);
@@ -4378,10 +4306,10 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
     DCHECK(destination->IsRegister() || destination->IsStackSlot());
     MemOperand src = g.ToMemOperand(source);
     if (destination->IsRegister()) {
-      __ LoadP(g.ToRegister(destination), src, r0);
+      __ LoadU64(g.ToRegister(destination), src, r0);
     } else {
       Register temp = kScratchReg;
-      __ LoadP(temp, src, r0);
+      __ LoadU64(temp, src, r0);
       __ StoreP(temp, g.ToMemOperand(destination), r0);
     }
   } else if (source->IsConstant()) {
@@ -4494,8 +4422,7 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
         DCHECK(destination->IsSimd128StackSlot());
         MemOperand dst = g.ToMemOperand(destination);
         __ mov(ip, Operand(dst.offset()));
-        __ StoreSimd128(g.ToSimd128Register(source), MemOperand(dst.ra(), ip),
-                        r0, kScratchSimd128Reg);
+        __ StoreSimd128(g.ToSimd128Register(source), MemOperand(dst.ra(), ip));
       }
     } else {
       DoubleRegister src = g.ToDoubleRegister(source);
@@ -4526,7 +4453,7 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
         MemOperand src = g.ToMemOperand(source);
         __ mov(ip, Operand(src.offset()));
         __ LoadSimd128(g.ToSimd128Register(destination),
-                       MemOperand(src.ra(), ip), r0, kScratchSimd128Reg);
+                       MemOperand(src.ra(), ip));
       }
     } else {
       LocationOperand* op = LocationOperand::cast(source);
@@ -4541,15 +4468,15 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
         DCHECK_EQ(MachineRepresentation::kSimd128, op->representation());
         // push v0, to be used as scratch
         __ addi(sp, sp, Operand(-kSimd128Size));
-        __ StoreSimd128(v0, MemOperand(r0, sp), r0, kScratchSimd128Reg);
+        __ StoreSimd128(v0, MemOperand(r0, sp));
         MemOperand src = g.ToMemOperand(source);
         MemOperand dst = g.ToMemOperand(destination);
         __ mov(ip, Operand(src.offset()));
-        __ LoadSimd128(v0, MemOperand(src.ra(), ip), r0, kScratchSimd128Reg);
+        __ LoadSimd128(v0, MemOperand(src.ra(), ip));
         __ mov(ip, Operand(dst.offset()));
-        __ StoreSimd128(v0, MemOperand(dst.ra(), ip), r0, kScratchSimd128Reg);
+        __ StoreSimd128(v0, MemOperand(dst.ra(), ip));
         // restore v0
-        __ LoadSimd128(v0, MemOperand(r0, sp), ip, kScratchSimd128Reg);
+        __ LoadSimd128(v0, MemOperand(r0, sp));
         __ addi(sp, sp, Operand(kSimd128Size));
       }
     }
diff --git a/chromium/v8/src/compiler/backend/ppc/instruction-codes-ppc.h b/chromium/v8/src/compiler/backend/ppc/instruction-codes-ppc.h
index 787cc2a27da..ccbce18045c 100644
--- a/chromium/v8/src/compiler/backend/ppc/instruction-codes-ppc.h
+++ b/chromium/v8/src/compiler/backend/ppc/instruction-codes-ppc.h
@@ -255,15 +255,9 @@ namespace compiler {
   V(PPC_I64x2Add)                    \
   V(PPC_I64x2Sub)                    \
   V(PPC_I64x2Mul)                    \
-  V(PPC_I64x2MinS)                   \
-  V(PPC_I64x2MinU)                   \
-  V(PPC_I64x2MaxS)                   \
-  V(PPC_I64x2MaxU)                   \
   V(PPC_I64x2Eq)                     \
   V(PPC_I64x2Ne)                     \
   V(PPC_I64x2GtS)                    \
-  V(PPC_I64x2GtU)                    \
-  V(PPC_I64x2GeU)                    \
   V(PPC_I64x2GeS)                    \
   V(PPC_I64x2Shl)                    \
   V(PPC_I64x2ShrS)                   \
diff --git a/chromium/v8/src/compiler/backend/ppc/instruction-scheduler-ppc.cc b/chromium/v8/src/compiler/backend/ppc/instruction-scheduler-ppc.cc
index 749905a0551..e6c59fef222 100644
--- a/chromium/v8/src/compiler/backend/ppc/instruction-scheduler-ppc.cc
+++ b/chromium/v8/src/compiler/backend/ppc/instruction-scheduler-ppc.cc
@@ -177,15 +177,9 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kPPC_I64x2Add:
     case kPPC_I64x2Sub:
     case kPPC_I64x2Mul:
-    case kPPC_I64x2MinS:
-    case kPPC_I64x2MinU:
-    case kPPC_I64x2MaxS:
-    case kPPC_I64x2MaxU:
     case kPPC_I64x2Eq:
     case kPPC_I64x2Ne:
     case kPPC_I64x2GtS:
-    case kPPC_I64x2GtU:
-    case kPPC_I64x2GeU:
     case kPPC_I64x2GeS:
     case kPPC_I64x2Shl:
     case kPPC_I64x2ShrS:
diff --git a/chromium/v8/src/compiler/backend/ppc/instruction-selector-ppc.cc b/chromium/v8/src/compiler/backend/ppc/instruction-selector-ppc.cc
index 849723bdac5..d4ef1086997 100644
--- a/chromium/v8/src/compiler/backend/ppc/instruction-selector-ppc.cc
+++ b/chromium/v8/src/compiler/backend/ppc/instruction-selector-ppc.cc
@@ -224,6 +224,7 @@ void InstructionSelector::VisitLoad(Node* node) {
       // Vectors do not support MRI mode, only MRR is available.
       mode = kNoImmediate;
       break;
+    case MachineRepresentation::kMapWord:  // Fall through.
     case MachineRepresentation::kNone:
       UNREACHABLE();
   }
@@ -356,6 +357,7 @@ void InstructionSelector::VisitStore(Node* node) {
         // Vectors do not support MRI mode, only MRR is available.
         mode = kNoImmediate;
         break;
+      case MachineRepresentation::kMapWord:  // Fall through.
       case MachineRepresentation::kNone:
         UNREACHABLE();
     }
@@ -2642,6 +2644,12 @@ void InstructionSelector::VisitStoreLane(Node* node) {
   Emit(opcode | AddressingModeField::encode(kMode_MRR), 0, nullptr, 4, inputs);
 }
 
+void InstructionSelector::AddOutputToSelectContinuation(OperandGenerator* g,
+                                                        int first_input_index,
+                                                        Node* node) {
+  UNREACHABLE();
+}
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
diff --git a/chromium/v8/src/compiler/backend/register-allocation.h b/chromium/v8/src/compiler/backend/register-allocation.h
index f4a7558b04a..37173da1fc3 100644
--- a/chromium/v8/src/compiler/backend/register-allocation.h
+++ b/chromium/v8/src/compiler/backend/register-allocation.h
@@ -65,6 +65,7 @@ inline int ByteWidthForStackSlot(MachineRepresentation rep) {
     case MachineRepresentation::kSimd128:
       return kSimd128Size;
     case MachineRepresentation::kNone:
+    case MachineRepresentation::kMapWord:
       break;
   }
   UNREACHABLE();
diff --git a/chromium/v8/src/compiler/backend/register-allocator-verifier.cc b/chromium/v8/src/compiler/backend/register-allocator-verifier.cc
index 1587f0ee182..b4099c5fad5 100644
--- a/chromium/v8/src/compiler/backend/register-allocator-verifier.cc
+++ b/chromium/v8/src/compiler/backend/register-allocator-verifier.cc
@@ -72,7 +72,7 @@ RegisterAllocatorVerifier::RegisterAllocatorVerifier(
   constraints_.reserve(sequence->instructions().size());
   // TODO(dcarney): model unique constraints.
   // Construct OperandConstraints for all InstructionOperands, eliminating
-  // kSameAsFirst along the way.
+  // kSameAsInput along the way.
   for (const Instruction* instr : sequence->instructions()) {
     // All gaps should be totally unallocated at this point.
     VerifyEmptyGaps(instr);
@@ -90,10 +90,11 @@ RegisterAllocatorVerifier::RegisterAllocatorVerifier(
     }
     for (size_t i = 0; i < instr->OutputCount(); ++i, ++count) {
       BuildConstraint(instr->OutputAt(i), &op_constraints[count]);
-      if (op_constraints[count].type_ == kSameAsFirst) {
-        CHECK_LT(0, instr->InputCount());
-        op_constraints[count].type_ = op_constraints[0].type_;
-        op_constraints[count].value_ = op_constraints[0].value_;
+      if (op_constraints[count].type_ == kSameAsInput) {
+        int input_index = op_constraints[count].value_;
+        CHECK_LT(input_index, instr->InputCount());
+        op_constraints[count].type_ = op_constraints[input_index].type_;
+        op_constraints[count].value_ = op_constraints[input_index].value_;
       }
       VerifyOutput(op_constraints[count]);
     }
@@ -105,7 +106,7 @@ RegisterAllocatorVerifier::RegisterAllocatorVerifier(
 
 void RegisterAllocatorVerifier::VerifyInput(
     const OperandConstraint& constraint) {
-  CHECK_NE(kSameAsFirst, constraint.type_);
+  CHECK_NE(kSameAsInput, constraint.type_);
   if (constraint.type_ != kImmediate) {
     CHECK_NE(InstructionOperand::kInvalidVirtualRegister,
              constraint.virtual_register_);
@@ -114,7 +115,7 @@ void RegisterAllocatorVerifier::VerifyInput(
 
 void RegisterAllocatorVerifier::VerifyTemp(
     const OperandConstraint& constraint) {
-  CHECK_NE(kSameAsFirst, constraint.type_);
+  CHECK_NE(kSameAsInput, constraint.type_);
   CHECK_NE(kImmediate, constraint.type_);
   CHECK_NE(kConstant, constraint.type_);
 }
@@ -212,8 +213,9 @@ void RegisterAllocatorVerifier::BuildConstraint(const InstructionOperand* op,
           constraint->value_ =
               ElementSizeLog2Of(sequence()->GetRepresentation(vreg));
           break;
-        case UnallocatedOperand::SAME_AS_FIRST_INPUT:
-          constraint->type_ = kSameAsFirst;
+        case UnallocatedOperand::SAME_AS_INPUT:
+          constraint->type_ = kSameAsInput;
+          constraint->value_ = unallocated->input_index();
           break;
       }
     }
@@ -269,7 +271,7 @@ void RegisterAllocatorVerifier::CheckConstraint(
       CHECK_WITH_MSG(op->IsRegister() || op->IsStackSlot() || op->IsConstant(),
                      caller_info_);
       return;
-    case kSameAsFirst:
+    case kSameAsInput:
       CHECK_WITH_MSG(false, caller_info_);
       return;
   }
diff --git a/chromium/v8/src/compiler/backend/register-allocator-verifier.h b/chromium/v8/src/compiler/backend/register-allocator-verifier.h
index 11bd4924f4e..c812642d338 100644
--- a/chromium/v8/src/compiler/backend/register-allocator-verifier.h
+++ b/chromium/v8/src/compiler/backend/register-allocator-verifier.h
@@ -219,7 +219,7 @@ class RegisterAllocatorVerifier final : public ZoneObject {
     kRegisterOrSlot,
     kRegisterOrSlotFP,
     kRegisterOrSlotOrConstant,
-    kSameAsFirst,
+    kSameAsInput,
     kRegisterAndSlot
   };
 
diff --git a/chromium/v8/src/compiler/backend/register-allocator.cc b/chromium/v8/src/compiler/backend/register-allocator.cc
index 3cd6cd98de0..0649fd5fd08 100644
--- a/chromium/v8/src/compiler/backend/register-allocator.cc
+++ b/chromium/v8/src/compiler/backend/register-allocator.cc
@@ -1373,21 +1373,6 @@ TopLevelLiveRange* TopTierRegisterAllocationData::NewLiveRange(
   return allocation_zone()->New<TopLevelLiveRange>(index, rep);
 }
 
-int TopTierRegisterAllocationData::GetNextLiveRangeId() {
-  int vreg = virtual_register_count_++;
-  if (vreg >= static_cast<int>(live_ranges().size())) {
-    live_ranges().resize(vreg + 1, nullptr);
-  }
-  return vreg;
-}
-
-TopLevelLiveRange* TopTierRegisterAllocationData::NextLiveRange(
-    MachineRepresentation rep) {
-  int vreg = GetNextLiveRangeId();
-  TopLevelLiveRange* ret = NewLiveRange(vreg, rep);
-  return ret;
-}
-
 TopTierRegisterAllocationData::PhiMapValue*
 TopTierRegisterAllocationData::InitializePhiMap(const InstructionBlock* block,
                                                 PhiInstruction* phi) {
@@ -1747,6 +1732,7 @@ void ConstraintBuilder::MeetConstraintsAfter(int instr_index) {
 void ConstraintBuilder::MeetConstraintsBefore(int instr_index) {
   Instruction* second = code()->InstructionAt(instr_index);
   // Handle fixed input operands of second instruction.
+  ZoneVector<TopLevelLiveRange*>* spilled_consts = nullptr;
   for (size_t i = 0; i < second->InputCount(); i++) {
     InstructionOperand* input = second->InputAt(i);
     if (input->IsImmediate()) {
@@ -1757,8 +1743,19 @@ void ConstraintBuilder::MeetConstraintsBefore(int instr_index) {
       TopLevelLiveRange* range =
           data()->GetOrCreateLiveRangeFor(cur_input->virtual_register());
       if (range->HasSpillOperand() && range->GetSpillOperand()->IsConstant()) {
+        bool already_spilled = false;
+        if (spilled_consts == nullptr) {
+          spilled_consts =
+              allocation_zone()->New<ZoneVector<TopLevelLiveRange*>>(
+                  allocation_zone());
+        } else {
+          auto it =
+              std::find(spilled_consts->begin(), spilled_consts->end(), range);
+          already_spilled = it != spilled_consts->end();
+        }
         auto it = data()->slot_for_const_range().find(range);
         if (it == data()->slot_for_const_range().end()) {
+          DCHECK(!already_spilled);
           int width = ByteWidthForStackSlot(range->representation());
           int index = data()->frame()->AllocateSpillSlot(width);
           auto* slot = AllocatedOperand::New(allocation_zone(),
@@ -1766,13 +1763,15 @@ void ConstraintBuilder::MeetConstraintsBefore(int instr_index) {
                                              range->representation(), index);
           it = data()->slot_for_const_range().emplace(range, slot).first;
         }
-        auto* slot = it->second;
-        int input_vreg = cur_input->virtual_register();
-        UnallocatedOperand input_copy(UnallocatedOperand::REGISTER_OR_SLOT,
-                                      input_vreg);
-        // Spill at every use position for simplicity. This case is very rare -
-        // the only known instance is crbug.com/1146880.
-        data()->AddGapMove(instr_index, Instruction::END, input_copy, *slot);
+        if (!already_spilled) {
+          auto* slot = it->second;
+          int input_vreg = cur_input->virtual_register();
+          UnallocatedOperand input_copy(UnallocatedOperand::REGISTER_OR_SLOT,
+                                        input_vreg);
+          // Spill at every use position for simplicity, this case is very rare.
+          data()->AddGapMove(instr_index, Instruction::END, input_copy, *slot);
+          spilled_consts->push_back(range);
+        }
       }
     }
     if (cur_input->HasFixedPolicy()) {
@@ -1792,7 +1791,7 @@ void ConstraintBuilder::MeetConstraintsBefore(int instr_index) {
     if (!second_output->HasSameAsInputPolicy()) continue;
     DCHECK_EQ(0, i);  // Only valid for first output.
     UnallocatedOperand* cur_input =
-        UnallocatedOperand::cast(second->InputAt(0));
+        UnallocatedOperand::cast(second->InputAt(second_output->input_index()));
     int output_vreg = second_output->virtual_register();
     int input_vreg = cur_input->virtual_register();
     UnallocatedOperand input_copy(UnallocatedOperand::REGISTER_OR_SLOT,
@@ -3958,7 +3957,8 @@ void LinearScanAllocator::FindFreeRegistersForRange(
       // interesting to this range anyway.
       // TODO(mtrofin): extend to aliased ranges, too.
       if ((kSimpleFPAliasing || !check_fp_aliasing()) &&
-          positions[cur_reg] <= cur_inactive->NextStart()) {
+          (positions[cur_reg] <= cur_inactive->NextStart() ||
+           range->End() <= cur_inactive->NextStart())) {
         break;
       }
       LifetimePosition next_intersection =
diff --git a/chromium/v8/src/compiler/backend/register-allocator.h b/chromium/v8/src/compiler/backend/register-allocator.h
index 214a1d1308f..a9c3ca5ae0c 100644
--- a/chromium/v8/src/compiler/backend/register-allocator.h
+++ b/chromium/v8/src/compiler/backend/register-allocator.h
@@ -305,7 +305,6 @@ class TopTierRegisterAllocationData final : public RegisterAllocationData {
   TopLevelLiveRange* GetOrCreateLiveRangeFor(int index);
   // Creates a new live range.
   TopLevelLiveRange* NewLiveRange(int index, MachineRepresentation rep);
-  TopLevelLiveRange* NextLiveRange(MachineRepresentation rep);
 
   SpillRange* AssignSpillRangeToLiveRange(TopLevelLiveRange* range,
                                           SpillMode spill_mode);
@@ -356,8 +355,6 @@ class TopTierRegisterAllocationData final : public RegisterAllocationData {
   }
 
  private:
-  int GetNextLiveRangeId();
-
   Zone* const allocation_zone_;
   Frame* const frame_;
   InstructionSequence* const code_;
diff --git a/chromium/v8/src/compiler/backend/riscv64/code-generator-riscv64.cc b/chromium/v8/src/compiler/backend/riscv64/code-generator-riscv64.cc
index f01941883ed..007edd7a96d 100644
--- a/chromium/v8/src/compiler/backend/riscv64/code-generator-riscv64.cc
+++ b/chromium/v8/src/compiler/backend/riscv64/code-generator-riscv64.cc
@@ -157,18 +157,16 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
         zone_(gen->zone()) {}
 
   void Generate() final {
-    if (mode_ > RecordWriteMode::kValueIsPointer) {
-      __ JumpIfSmi(value_, exit());
-    }
     __ CheckPageFlag(value_, scratch0_,
                      MemoryChunk::kPointersToHereAreInterestingMask, eq,
                      exit());
     __ Add64(scratch1_, object_, index_);
     RememberedSetAction const remembered_set_action =
-        mode_ > RecordWriteMode::kValueIsMap ? EMIT_REMEMBERED_SET
-                                             : OMIT_REMEMBERED_SET;
-    SaveFPRegsMode const save_fp_mode =
-        frame()->DidAllocateDoubleRegisters() ? kSaveFPRegs : kDontSaveFPRegs;
+        mode_ > RecordWriteMode::kValueIsMap ? RememberedSetAction::kEmit
+                                             : RememberedSetAction::kOmit;
+    SaveFPRegsMode const save_fp_mode = frame()->DidAllocateDoubleRegisters()
+                                            ? SaveFPRegsMode::kSave
+                                            : SaveFPRegsMode::kIgnore;
     if (must_save_lr_) {
       // We need to save and restore ra if the frame was elided.
       __ Push(ra);
@@ -488,6 +486,11 @@ void CodeGenerator::AssemblePrepareTailCall() {
   frame_access_state()->SetFrameAccessToSP();
 }
 
+void CodeGenerator::AssembleArchSelect(Instruction* instr,
+                                       FlagsCondition condition) {
+  UNIMPLEMENTED();
+}
+
 namespace {
 
 void AdjustStackPointerForTailCall(TurboAssembler* tasm,
@@ -606,8 +609,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
         Address wasm_code = static_cast<Address>(constant.ToInt64());
         __ Call(wasm_code, constant.rmode());
       } else {
-        __ Add64(kScratchReg, i.InputRegister(0), 0);
-        __ Call(kScratchReg);
+        __ Add64(t6, i.InputRegister(0), 0);
+        __ Call(t6);
       }
       RecordCallPosition(instr);
       frame_access_state()->ClearSPDelta();
@@ -676,7 +679,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchSaveCallerRegisters: {
       fp_mode_ =
           static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode()));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // kReturnRegister0 should have been saved before entering the stub.
       int bytes = __ PushCallerSaved(fp_mode_, kReturnRegister0);
       DCHECK(IsAligned(bytes, kSystemPointerSize));
@@ -689,7 +693,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchRestoreCallerRegisters: {
       DCHECK(fp_mode_ ==
              static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode())));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // Don't overwrite the returned value.
       int bytes = __ PopCallerSaved(fp_mode_, kReturnRegister0);
       frame_access_state()->IncreaseSPDelta(-(bytes / kSystemPointerSize));
@@ -816,6 +821,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                                                    DetermineStubCallMode());
       __ Add64(kScratchReg, object, index);
       __ Sd(value, MemOperand(kScratchReg));
+      if (mode > RecordWriteMode::kValueIsPointer) {
+        __ JumpIfSmi(value, ool->exit());
+      }
       __ CheckPageFlag(object, scratch0,
                        MemoryChunk::kPointersFromHereAreInterestingMask, ne,
                        ool->entry());
@@ -1122,6 +1130,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kRiscvCmp:
       // Pseudo-instruction used for cmp/branch. No opcode emitted here.
       break;
+    case kRiscvCmpZero:
+      // Pseudo-instruction used for cmpzero/branch. No opcode emitted here.
+      break;
     case kRiscvMov:
       // TODO(plind): Should we combine mov/li like this, or use separate instr?
       //    - Also see x64 ASSEMBLE_BINOP & RegisterOrOperandType
@@ -1841,7 +1852,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       UNIMPLEMENTED();
   }
   return kSuccess;
-}  // NOLINT(readability/fn_size)
+}
 
 #define UNSUPPORTED_COND(opcode, condition)                                    \
   StdoutStream{} << "Unsupported " << #opcode << " condition: \"" << condition \
@@ -1902,6 +1913,9 @@ void AssembleBranchToLabels(CodeGenerator* gen, TurboAssembler* tasm,
   } else if (instr->arch_opcode() == kRiscvCmp) {
     cc = FlagsConditionToConditionCmp(condition);
     __ Branch(tlabel, cc, i.InputRegister(0), i.InputOperand(1));
+  } else if (instr->arch_opcode() == kRiscvCmpZero) {
+    cc = FlagsConditionToConditionCmp(condition);
+    __ Branch(tlabel, cc, i.InputRegister(0), Operand(zero_reg));
   } else if (instr->arch_opcode() == kArchStackPointerGreaterThan) {
     cc = FlagsConditionToConditionCmp(condition);
     Register lhs_register = sp;
@@ -1957,6 +1971,12 @@ void CodeGenerator::AssembleBranchPoisoning(FlagsCondition condition,
       __ LoadZeroIfConditionNotZero(kSpeculationPoisonRegister, kScratchReg);
     }
       return;
+    case kRiscvCmpZero: {
+      __ CompareI(kScratchReg, i.InputRegister(0), Operand(zero_reg),
+                  FlagsConditionToConditionCmp(condition));
+      __ LoadZeroIfConditionNotZero(kSpeculationPoisonRegister, kScratchReg);
+    }
+      return;
     case kRiscvTst: {
       switch (condition) {
         case kEqual:
@@ -2224,6 +2244,68 @@ void CodeGenerator::AssembleArchBoolean(Instruction* instr,
         UNREACHABLE();
     }
     return;
+  } else if (instr->arch_opcode() == kRiscvCmpZero) {
+    cc = FlagsConditionToConditionCmp(condition);
+    switch (cc) {
+      case eq: {
+        Register left = i.InputRegister(0);
+        __ Sltu(result, left, 1);
+        break;
+      }
+      case ne: {
+        Register left = i.InputRegister(0);
+        __ Sltu(result, zero_reg, left);
+        break;
+      }
+      case lt:
+      case ge: {
+        Register left = i.InputRegister(0);
+        Operand right = Operand(zero_reg);
+        __ Slt(result, left, right);
+        if (cc == ge) {
+          __ Xor(result, result, 1);
+        }
+      } break;
+      case gt:
+      case le: {
+        Operand left = i.InputOperand(0);
+        __ Slt(result, zero_reg, left);
+        if (cc == le) {
+          __ Xor(result, result, 1);
+        }
+      } break;
+      case Uless:
+      case Ugreater_equal: {
+        Register left = i.InputRegister(0);
+        Operand right = Operand(zero_reg);
+        __ Sltu(result, left, right);
+        if (cc == Ugreater_equal) {
+          __ Xor(result, result, 1);
+        }
+      } break;
+      case Ugreater:
+      case Uless_equal: {
+        Register left = zero_reg;
+        Operand right = i.InputOperand(0);
+        __ Sltu(result, left, right);
+        if (cc == Uless_equal) {
+          __ Xor(result, result, 1);
+        }
+      } break;
+      default:
+        UNREACHABLE();
+    }
+    return;
+  } else if (instr->arch_opcode() == kArchStackPointerGreaterThan) {
+    cc = FlagsConditionToConditionCmp(condition);
+    Register lhs_register = sp;
+    uint32_t offset;
+    if (ShouldApplyOffsetToStackCheck(instr, &offset)) {
+      lhs_register = i.TempRegister(0);
+      __ Sub64(lhs_register, sp, offset);
+    }
+    __ Sgtu(result, lhs_register, Operand(i.InputRegister(0)));
+    return;
   } else if (instr->arch_opcode() == kRiscvCmpD ||
              instr->arch_opcode() == kRiscvCmpS) {
     FPURegister left = i.InputOrZeroDoubleRegister(0);
@@ -2346,7 +2428,7 @@ void CodeGenerator::AssembleConstructFrame() {
     // frame is still on the stack. Optimized code uses OSR values directly from
     // the unoptimized frame. Thus, all that needs to be done is to allocate the
     // remaining stack slots.
-    if (FLAG_code_comments) __ RecordComment("-- OSR entrypoint --");
+    __ RecordComment("-- OSR entrypoint --");
     osr_pc_offset_ = __ pc_offset();
     required_slots -= osr_helper()->UnoptimizedFrameSlots();
     ResetSpeculationPoison();
@@ -2448,7 +2530,7 @@ void CodeGenerator::AssembleReturn(InstructionOperand* additional_pop_count) {
   if (parameter_slots != 0) {
     if (additional_pop_count->IsImmediate()) {
       DCHECK_EQ(g.ToConstant(additional_pop_count).ToInt32(), 0);
-    } else if (__ emit_debug_code()) {
+    } else if (FLAG_debug_code) {
       __ Assert(eq, AbortReason::kUnexpectedAdditionalPopValue,
                 g.ToRegister(additional_pop_count),
                 Operand(static_cast<int64_t>(0)));
@@ -2510,7 +2592,7 @@ void CodeGenerator::AssembleReturn(InstructionOperand* additional_pop_count) {
   __ Ret();
 }
 
-void CodeGenerator::FinishCode() {}
+void CodeGenerator::FinishCode() { __ ForceConstantPoolEmissionWithoutJump(); }
 
 void CodeGenerator::PrepareForDeoptimizationExits(
     ZoneDeque<DeoptimizationExit*>* exits) {}
diff --git a/chromium/v8/src/compiler/backend/riscv64/instruction-codes-riscv64.h b/chromium/v8/src/compiler/backend/riscv64/instruction-codes-riscv64.h
index 61921d15855..f230ce3377e 100644
--- a/chromium/v8/src/compiler/backend/riscv64/instruction-codes-riscv64.h
+++ b/chromium/v8/src/compiler/backend/riscv64/instruction-codes-riscv64.h
@@ -59,6 +59,7 @@ namespace compiler {
   V(RiscvMov)                               \
   V(RiscvTst)                               \
   V(RiscvCmp)                               \
+  V(RiscvCmpZero)                           \
   V(RiscvCmpS)                              \
   V(RiscvAddS)                              \
   V(RiscvSubS)                              \
diff --git a/chromium/v8/src/compiler/backend/riscv64/instruction-scheduler-riscv64.cc b/chromium/v8/src/compiler/backend/riscv64/instruction-scheduler-riscv64.cc
index b83942ffce8..c9210ded8fd 100644
--- a/chromium/v8/src/compiler/backend/riscv64/instruction-scheduler-riscv64.cc
+++ b/chromium/v8/src/compiler/backend/riscv64/instruction-scheduler-riscv64.cc
@@ -32,6 +32,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kRiscvCeilWS:
     case kRiscvClz32:
     case kRiscvCmp:
+    case kRiscvCmpZero:
     case kRiscvCmpD:
     case kRiscvCmpS:
     case kRiscvCtz32:
@@ -812,7 +813,7 @@ int MultiPushFPULatency() {
 
 int PushCallerSavedLatency(SaveFPRegsMode fp_mode) {
   int latency = MultiPushLatency();
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     latency += MultiPushFPULatency();
   }
   return latency;
@@ -836,7 +837,7 @@ int MultiPopFPULatency() {
 
 int PopCallerSavedLatency(SaveFPRegsMode fp_mode) {
   int latency = MultiPopLatency();
-  if (fp_mode == kSaveFPRegs) {
+  if (fp_mode == SaveFPRegsMode::kSave) {
     latency += MultiPopFPULatency();
   }
   return latency;
diff --git a/chromium/v8/src/compiler/backend/riscv64/instruction-selector-riscv64.cc b/chromium/v8/src/compiler/backend/riscv64/instruction-selector-riscv64.cc
index 1d6b506685e..83865fde131 100644
--- a/chromium/v8/src/compiler/backend/riscv64/instruction-selector-riscv64.cc
+++ b/chromium/v8/src/compiler/backend/riscv64/instruction-selector-riscv64.cc
@@ -459,6 +459,7 @@ void InstructionSelector::VisitLoad(Node* node) {
       break;
     case MachineRepresentation::kCompressedPointer:  // Fall through.
     case MachineRepresentation::kCompressed:         // Fall through.
+    case MachineRepresentation::kMapWord:            // Fall through.
     case MachineRepresentation::kNone:
       UNREACHABLE();
   }
@@ -533,6 +534,7 @@ void InstructionSelector::VisitStore(Node* node) {
         break;
       case MachineRepresentation::kCompressedPointer:  // Fall through.
       case MachineRepresentation::kCompressed:         // Fall through.
+      case MachineRepresentation::kMapWord:            // Fall through.
       case MachineRepresentation::kNone:
         UNREACHABLE();
     }
@@ -1214,7 +1216,9 @@ void InstructionSelector::VisitBitcastWord32ToWord64(Node* node) {
 
 void InstructionSelector::VisitChangeInt32ToInt64(Node* node) {
   Node* value = node->InputAt(0);
-  if (value->opcode() == IrOpcode::kLoad && CanCover(node, value)) {
+  if ((value->opcode() == IrOpcode::kLoad ||
+       value->opcode() == IrOpcode::kLoadImmutable) &&
+      CanCover(node, value)) {
     // Generate sign-extending load.
     LoadRepresentation load_rep = LoadRepresentationOf(value->op());
     InstructionCode opcode = kArchNop;
@@ -1242,7 +1246,8 @@ void InstructionSelector::VisitChangeInt32ToInt64(Node* node) {
 
 bool InstructionSelector::ZeroExtendsWord32ToWord64NoPhis(Node* node) {
   DCHECK_NE(node->opcode(), IrOpcode::kPhi);
-  if (node->opcode() == IrOpcode::kLoad) {
+  if (node->opcode() == IrOpcode::kLoad ||
+      node->opcode() == IrOpcode::kLoadImmutable) {
     LoadRepresentation load_rep = LoadRepresentationOf(node->op());
     if (load_rep.IsUnsigned()) {
       switch (load_rep.representation()) {
@@ -1598,6 +1603,7 @@ void InstructionSelector::VisitUnalignedLoad(Node* node) {
     case MachineRepresentation::kBit:                // Fall through.
     case MachineRepresentation::kCompressedPointer:  // Fall through.
     case MachineRepresentation::kCompressed:         // Fall through.
+    case MachineRepresentation::kMapWord:            // Fall through.
     case MachineRepresentation::kNone:
       UNREACHABLE();
   }
@@ -1651,6 +1657,7 @@ void InstructionSelector::VisitUnalignedStore(Node* node) {
     case MachineRepresentation::kBit:                // Fall through.
     case MachineRepresentation::kCompressedPointer:  // Fall through.
     case MachineRepresentation::kCompressed:         // Fall through.
+    case MachineRepresentation::kMapWord:            // Fall through.
     case MachineRepresentation::kNone:
       UNREACHABLE();
   }
@@ -1878,8 +1885,7 @@ void VisitWord64Compare(InstructionSelector* selector, Node* node,
 void EmitWordCompareZero(InstructionSelector* selector, Node* value,
                          FlagsContinuation* cont) {
   RiscvOperandGenerator g(selector);
-  selector->EmitWithContinuation(kRiscvCmp, g.UseRegister(value),
-                                 g.TempImmediate(0), cont);
+  selector->EmitWithContinuation(kRiscvCmpZero, g.UseRegister(value), cont);
 }
 
 void VisitAtomicLoad(InstructionSelector* selector, Node* node,
@@ -2654,7 +2660,7 @@ void InstructionSelector::VisitInt64AbsWithOverflow(Node* node) {
   V(I32x4AllTrue, kRiscvI32x4AllTrue)                       \
   V(I16x8AllTrue, kRiscvI16x8AllTrue)                       \
   V(I8x16AllTrue, kRiscvI8x16AllTrue)                       \
-  V(I64x2AllTrue, kRiscvI64x2AllTrue)                       \
+  V(I64x2AllTrue, kRiscvI64x2AllTrue)
 
 #define SIMD_SHIFT_OP_LIST(V) \
   V(I64x2Shl)                 \
@@ -3015,6 +3021,12 @@ VISIT_EXT_MUL(I16x8, I8x16S)
 VISIT_EXT_MUL(I16x8, I8x16U)
 #undef VISIT_EXT_MUL
 
+void InstructionSelector::AddOutputToSelectContinuation(OperandGenerator* g,
+                                                        int first_input_index,
+                                                        Node* node) {
+  UNREACHABLE();
+}
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
diff --git a/chromium/v8/src/compiler/backend/s390/code-generator-s390.cc b/chromium/v8/src/compiler/backend/s390/code-generator-s390.cc
index c5e16b3e49c..a6c7dda9b48 100644
--- a/chromium/v8/src/compiler/backend/s390/code-generator-s390.cc
+++ b/chromium/v8/src/compiler/backend/s390/code-generator-s390.cc
@@ -206,9 +206,6 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
         zone_(gen->zone()) {}
 
   void Generate() final {
-    if (mode_ > RecordWriteMode::kValueIsPointer) {
-      __ JumpIfSmi(value_, exit());
-    }
     if (COMPRESS_POINTERS_BOOL) {
       __ DecompressTaggedPointer(value_, value_);
     }
@@ -222,10 +219,11 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
       __ AddS64(scratch1_, object_, offset_);
     }
     RememberedSetAction const remembered_set_action =
-        mode_ > RecordWriteMode::kValueIsMap ? EMIT_REMEMBERED_SET
-                                             : OMIT_REMEMBERED_SET;
-    SaveFPRegsMode const save_fp_mode =
-        frame()->DidAllocateDoubleRegisters() ? kSaveFPRegs : kDontSaveFPRegs;
+        mode_ > RecordWriteMode::kValueIsMap ? RememberedSetAction::kEmit
+                                             : RememberedSetAction::kOmit;
+    SaveFPRegsMode const save_fp_mode = frame()->DidAllocateDoubleRegisters()
+                                            ? SaveFPRegsMode::kSave
+                                            : SaveFPRegsMode::kIgnore;
     if (must_save_lr_) {
       // We need to save and restore r14 if the frame was elided.
       __ Push(r14);
@@ -1207,7 +1205,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchSaveCallerRegisters: {
       fp_mode_ =
           static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode()));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // kReturnRegister0 should have been saved before entering the stub.
       int bytes = __ PushCallerSaved(fp_mode_, kReturnRegister0);
       DCHECK(IsAligned(bytes, kSystemPointerSize));
@@ -1220,7 +1219,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchRestoreCallerRegisters: {
       DCHECK(fp_mode_ ==
              static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode())));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // Don't overwrite the returned value.
       int bytes = __ PopCallerSaved(fp_mode_, kReturnRegister0);
       frame_access_state()->IncreaseSPDelta(-(bytes / kSystemPointerSize));
@@ -1374,6 +1374,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
             DetermineStubCallMode(), &unwinding_info_writer_);
         __ StoreTaggedField(value, MemOperand(object, offset));
       }
+      if (mode > RecordWriteMode::kValueIsPointer) {
+        __ JumpIfSmi(value, ool->exit());
+      }
       __ CheckPageFlag(object, scratch0,
                        MemoryChunk::kPointersFromHereAreInterestingMask, ne,
                        ool->entry());
@@ -1692,16 +1695,13 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       ASSEMBLE_UNARY_OP(D_DInstr(sqdbr), nullInstr, nullInstr);
       break;
     case kS390_FloorFloat:
-      __ fiebra(ROUND_TOWARD_NEG_INF, i.OutputDoubleRegister(),
-                i.InputDoubleRegister(0));
+      __ FloorF32(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
       break;
     case kS390_CeilFloat:
-      __ fiebra(ROUND_TOWARD_POS_INF, i.OutputDoubleRegister(),
-                i.InputDoubleRegister(0));
+      __ CeilF32(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
       break;
     case kS390_TruncateFloat:
-      __ fiebra(ROUND_TOWARD_0, i.OutputDoubleRegister(),
-                i.InputDoubleRegister(0));
+      __ TruncF32(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
       break;
     //  Double operations
     case kS390_ModDouble:
@@ -1797,16 +1797,13 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ lpdbr(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
       break;
     case kS390_FloorDouble:
-      __ fidbra(ROUND_TOWARD_NEG_INF, i.OutputDoubleRegister(),
-                i.InputDoubleRegister(0));
+      __ FloorF64(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
       break;
     case kS390_CeilDouble:
-      __ fidbra(ROUND_TOWARD_POS_INF, i.OutputDoubleRegister(),
-                i.InputDoubleRegister(0));
+      __ CeilF64(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
       break;
     case kS390_TruncateDouble:
-      __ fidbra(ROUND_TOWARD_0, i.OutputDoubleRegister(),
-                i.InputDoubleRegister(0));
+      __ TruncF64(i.OutputDoubleRegister(), i.InputDoubleRegister(0));
       break;
     case kS390_RoundDouble:
       __ fidbra(ROUND_TO_NEAREST_AWAY_FROM_0, i.OutputDoubleRegister(),
@@ -2992,12 +2989,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kS390_I32x4GeS: {
-      __ vceq(kScratchDoubleReg, i.InputSimd128Register(0),
-              i.InputSimd128Register(1), Condition(0), Condition(2));
-      __ vch(i.OutputSimd128Register(), i.InputSimd128Register(0),
-             i.InputSimd128Register(1), Condition(0), Condition(2));
-      __ vo(i.OutputSimd128Register(), i.OutputSimd128Register(),
-            kScratchDoubleReg, Condition(0), Condition(0), Condition(2));
+      __ vch(kScratchDoubleReg, i.InputSimd128Register(1),
+             i.InputSimd128Register(0), Condition(0), Condition(2));
+      __ vno(i.OutputSimd128Register(), kScratchDoubleReg, kScratchDoubleReg,
+             Condition(0), Condition(0), Condition(2));
       break;
     }
     case kS390_I32x4GtU: {
@@ -3020,12 +3015,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kS390_I16x8GeS: {
-      __ vceq(kScratchDoubleReg, i.InputSimd128Register(0),
-              i.InputSimd128Register(1), Condition(0), Condition(1));
-      __ vch(i.OutputSimd128Register(), i.InputSimd128Register(0),
-             i.InputSimd128Register(1), Condition(0), Condition(1));
-      __ vo(i.OutputSimd128Register(), i.OutputSimd128Register(),
-            kScratchDoubleReg, Condition(0), Condition(0), Condition(1));
+      __ vch(kScratchDoubleReg, i.InputSimd128Register(1),
+             i.InputSimd128Register(0), Condition(0), Condition(1));
+      __ vno(i.OutputSimd128Register(), kScratchDoubleReg, kScratchDoubleReg,
+             Condition(0), Condition(0), Condition(1));
       break;
     }
     case kS390_I16x8GtU: {
@@ -3048,12 +3041,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kS390_I8x16GeS: {
-      __ vceq(kScratchDoubleReg, i.InputSimd128Register(0),
-              i.InputSimd128Register(1), Condition(0), Condition(0));
-      __ vch(i.OutputSimd128Register(), i.InputSimd128Register(0),
-             i.InputSimd128Register(1), Condition(0), Condition(0));
-      __ vo(i.OutputSimd128Register(), i.OutputSimd128Register(),
-            kScratchDoubleReg, Condition(0), Condition(0), Condition(0));
+      __ vch(kScratchDoubleReg, i.InputSimd128Register(1),
+             i.InputSimd128Register(0), Condition(0), Condition(0));
+      __ vno(i.OutputSimd128Register(), kScratchDoubleReg, kScratchDoubleReg,
+             Condition(0), Condition(0), Condition(0));
       break;
     }
     case kS390_I8x16GtU: {
@@ -3289,11 +3280,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kS390_S128Const: {
-      for (int index = 0, j = 0; index < 2; index++, j = +2) {
-        __ mov(index < 1 ? ip : r0, Operand(i.InputInt32(j)));
-        __ iihf(index < 1 ? ip : r0, Operand(i.InputInt32(j + 1)));
-      }
-      __ vlvgp(i.OutputSimd128Register(), r0, ip);
+      uint64_t low = make_uint64(i.InputUint32(1), i.InputUint32(0));
+      uint64_t high = make_uint64(i.InputUint32(3), i.InputUint32(2));
+      __ mov(r0, Operand(low));
+      __ mov(ip, Operand(high));
+      __ vlvgp(i.OutputSimd128Register(), ip, r0);
       break;
     }
     case kS390_S128Zero: {
@@ -3561,15 +3552,12 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       Simd128Register dst = i.OutputSimd128Register(),
                       src0 = i.InputSimd128Register(0),
                       src1 = i.InputSimd128Register(1);
-      int32_t k8x16_indices[] = {i.InputInt32(2), i.InputInt32(3),
-                                 i.InputInt32(4), i.InputInt32(5)};
-      // create 2 * 8 byte inputs indicating new indices
-      for (int i = 0, j = 0; i < 2; i++, j = +2) {
-        __ mov(i < 1 ? ip : r0, Operand(k8x16_indices[j]));
-        __ iihf(i < 1 ? ip : r0, Operand(k8x16_indices[j + 1]));
-      }
-      __ vlvgp(kScratchDoubleReg, r0, ip);
-      __ vperm(dst, src0, src1, kScratchDoubleReg, Condition(0), Condition(0));
+      uint64_t low = make_uint64(i.InputUint32(3), i.InputUint32(2));
+      uint64_t high = make_uint64(i.InputUint32(5), i.InputUint32(4));
+      __ mov(r0, Operand(low));
+      __ mov(ip, Operand(high));
+      __ vlvgp(dst, ip, r0);
+      __ vperm(dst, src0, src1, dst, Condition(0), Condition(0));
       break;
     }
     case kS390_I8x16Swizzle: {
@@ -3712,80 +3700,65 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
             Condition(0), Condition(0), Condition(2));
       break;
     }
-#define ASSEMBLE_SIMD_I64X2_EXT_MUL(UNPACK_INSTR)                              \
-  __ UNPACK_INSTR(kScratchDoubleReg, i.InputSimd128Register(0), Condition(0),  \
-                  Condition(0), Condition(2));                                 \
-  __ UNPACK_INSTR(i.OutputSimd128Register(), i.InputSimd128Register(1),        \
-                  Condition(0), Condition(0), Condition(2));                   \
-  Register scratch_0 = r0;                                                     \
-  Register scratch_1 = r1;                                                     \
-  for (int lane = 0; lane < 2; lane++) {                                       \
-    __ vlgv(scratch_0, kScratchDoubleReg, MemOperand(r0, lane), Condition(3)); \
-    __ vlgv(scratch_1, i.OutputSimd128Register(), MemOperand(r0, lane),        \
-            Condition(3));                                                     \
-    __ MulS64(scratch_0, scratch_1);                                           \
-    scratch_0 = r1;                                                            \
-    scratch_1 = ip;                                                            \
-  }                                                                            \
-  __ vlvgp(i.OutputSimd128Register(), r0, r1);
+#define EXT_MUL(mul_even, mul_odd, merge, mode)                              \
+  Simd128Register dst = i.OutputSimd128Register(),                           \
+                  src0 = i.InputSimd128Register(0),                          \
+                  src1 = i.InputSimd128Register(1);                          \
+  __ mul_even(dst, src0, src1, Condition(0), Condition(0), Condition(mode)); \
+  __ mul_odd(kScratchDoubleReg, src0, src1, Condition(0), Condition(0),      \
+             Condition(mode));                                               \
+  __ merge(dst, dst, kScratchDoubleReg, Condition(0), Condition(0),          \
+           Condition(mode + 1));
     case kS390_I64x2ExtMulLowI32x4S: {
-      ASSEMBLE_SIMD_I64X2_EXT_MUL(vupl)
+      EXT_MUL(vme, vmo, vmrl, 2)
       break;
     }
     case kS390_I64x2ExtMulHighI32x4S: {
-      ASSEMBLE_SIMD_I64X2_EXT_MUL(vuph)
+      EXT_MUL(vme, vmo, vmrh, 2)
       break;
     }
     case kS390_I64x2ExtMulLowI32x4U: {
-      ASSEMBLE_SIMD_I64X2_EXT_MUL(vupll)
+      EXT_MUL(vmle, vmlo, vmrl, 2)
       break;
     }
     case kS390_I64x2ExtMulHighI32x4U: {
-      ASSEMBLE_SIMD_I64X2_EXT_MUL(vuplh)
-      break;
-    }
-#undef ASSEMBLE_SIMD_I64X2_EXT_MUL
-#define ASSEMBLE_SIMD_I32X4_I16X8_EXT_MUL(UNPACK_INSTR, MODE)                 \
-  __ UNPACK_INSTR(kScratchDoubleReg, i.InputSimd128Register(0), Condition(0), \
-                  Condition(0), Condition(MODE));                             \
-  __ UNPACK_INSTR(i.OutputSimd128Register(), i.InputSimd128Register(1),       \
-                  Condition(0), Condition(0), Condition(MODE));               \
-  __ vml(i.OutputSimd128Register(), kScratchDoubleReg,                        \
-         i.OutputSimd128Register(), Condition(0), Condition(0),               \
-         Condition(MODE + 1));
+      EXT_MUL(vmle, vmlo, vmrh, 2)
+      break;
+    }
     case kS390_I32x4ExtMulLowI16x8S: {
-      ASSEMBLE_SIMD_I32X4_I16X8_EXT_MUL(vupl, 1)
+      EXT_MUL(vme, vmo, vmrl, 1)
       break;
     }
     case kS390_I32x4ExtMulHighI16x8S: {
-      ASSEMBLE_SIMD_I32X4_I16X8_EXT_MUL(vuph, 1)
+      EXT_MUL(vme, vmo, vmrh, 1)
       break;
     }
     case kS390_I32x4ExtMulLowI16x8U: {
-      ASSEMBLE_SIMD_I32X4_I16X8_EXT_MUL(vupll, 1)
+      EXT_MUL(vmle, vmlo, vmrl, 1)
       break;
     }
     case kS390_I32x4ExtMulHighI16x8U: {
-      ASSEMBLE_SIMD_I32X4_I16X8_EXT_MUL(vuplh, 1)
+      EXT_MUL(vmle, vmlo, vmrh, 1)
       break;
     }
+
     case kS390_I16x8ExtMulLowI8x16S: {
-      ASSEMBLE_SIMD_I32X4_I16X8_EXT_MUL(vupl, 0)
+      EXT_MUL(vme, vmo, vmrl, 0)
       break;
     }
     case kS390_I16x8ExtMulHighI8x16S: {
-      ASSEMBLE_SIMD_I32X4_I16X8_EXT_MUL(vuph, 0)
+      EXT_MUL(vme, vmo, vmrh, 0)
       break;
     }
     case kS390_I16x8ExtMulLowI8x16U: {
-      ASSEMBLE_SIMD_I32X4_I16X8_EXT_MUL(vupll, 0)
+      EXT_MUL(vmle, vmlo, vmrl, 0)
       break;
     }
     case kS390_I16x8ExtMulHighI8x16U: {
-      ASSEMBLE_SIMD_I32X4_I16X8_EXT_MUL(vuplh, 0)
+      EXT_MUL(vmle, vmlo, vmrh, 0)
       break;
     }
-#undef ASSEMBLE_SIMD_I32X4_I16X8_EXT_MUL
+#undef EXT_MUL
 #define EXT_ADD_PAIRWISE(lane_size, mul_even, mul_odd)                        \
   Simd128Register src = i.InputSimd128Register(0);                            \
   Simd128Register dst = i.OutputSimd128Register();                            \
@@ -3942,7 +3915,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       UNREACHABLE();
   }
   return kSuccess;
-}  // NOLINT(readability/fn_size)
+}
 
 // Assembles branches after an instruction.
 void CodeGenerator::AssembleArchBranch(Instruction* instr, BranchInfo* branch) {
@@ -4204,7 +4177,7 @@ void CodeGenerator::AssembleConstructFrame() {
     // frame is still on the stack. Optimized code uses OSR values directly from
     // the unoptimized frame. Thus, all that needs to be done is to allocate the
     // remaining stack slots.
-    if (FLAG_code_comments) __ RecordComment("-- OSR entrypoint --");
+    __ RecordComment("-- OSR entrypoint --");
     osr_pc_offset_ = __ pc_offset();
     required_slots -= osr_helper()->UnoptimizedFrameSlots();
     ResetSpeculationPoison();
@@ -4309,7 +4282,7 @@ void CodeGenerator::AssembleReturn(InstructionOperand* additional_pop_count) {
   if (parameter_slots != 0) {
     if (additional_pop_count->IsImmediate()) {
       DCHECK_EQ(g.ToConstant(additional_pop_count).ToInt32(), 0);
-    } else if (__ emit_debug_code()) {
+    } else if (FLAG_debug_code) {
       __ CmpS64(g.ToRegister(additional_pop_count), Operand(0));
       __ Assert(eq, AbortReason::kUnexpectedAdditionalPopValue);
     }
diff --git a/chromium/v8/src/compiler/backend/s390/instruction-selector-s390.cc b/chromium/v8/src/compiler/backend/s390/instruction-selector-s390.cc
index f2375525bb3..8be70adf547 100644
--- a/chromium/v8/src/compiler/backend/s390/instruction-selector-s390.cc
+++ b/chromium/v8/src/compiler/backend/s390/instruction-selector-s390.cc
@@ -141,7 +141,8 @@ class S390OperandGenerator final : public OperandGenerator {
 
   bool CanBeMemoryOperand(InstructionCode opcode, Node* user, Node* input,
                           int effect_level) {
-    if (input->opcode() != IrOpcode::kLoad ||
+    if ((input->opcode() != IrOpcode::kLoad &&
+         input->opcode() != IrOpcode::kLoadImmutable) ||
         !selector()->CanCover(user, input)) {
       return false;
     }
@@ -320,6 +321,7 @@ ArchOpcode SelectLoadOpcode(Node* node) {
     case MachineRepresentation::kSimd128:
       opcode = kS390_LoadSimd128;
       break;
+    case MachineRepresentation::kMapWord:  // Fall through.
     case MachineRepresentation::kNone:
     default:
       UNREACHABLE();
@@ -798,6 +800,7 @@ static void VisitGeneralStore(
           value = value->InputAt(0);
         }
         break;
+      case MachineRepresentation::kMapWord:  // Fall through.
       case MachineRepresentation::kNone:
         UNREACHABLE();
     }
@@ -2849,6 +2852,12 @@ void InstructionSelector::VisitTruncateFloat32ToUint32(Node* node) {
   Emit(opcode, g.DefineAsRegister(node), g.UseRegister(node->InputAt(0)));
 }
 
+void InstructionSelector::AddOutputToSelectContinuation(OperandGenerator* g,
+                                                        int first_input_index,
+                                                        Node* node) {
+  UNREACHABLE();
+}
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
diff --git a/chromium/v8/src/compiler/backend/x64/code-generator-x64.cc b/chromium/v8/src/compiler/backend/x64/code-generator-x64.cc
index 814f14fb4af..11bba2f0f80 100644
--- a/chromium/v8/src/compiler/backend/x64/code-generator-x64.cc
+++ b/chromium/v8/src/compiler/backend/x64/code-generator-x64.cc
@@ -276,9 +276,6 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
   }
 
   void Generate() final {
-    if (mode_ > RecordWriteMode::kValueIsPointer) {
-      __ JumpIfSmi(value_, exit());
-    }
     if (COMPRESS_POINTERS_BOOL) {
       __ DecompressTaggedPointer(value_, value_);
     }
@@ -288,10 +285,11 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
     __ leaq(scratch1_, operand_);
 
     RememberedSetAction const remembered_set_action =
-        mode_ > RecordWriteMode::kValueIsMap ? EMIT_REMEMBERED_SET
-                                             : OMIT_REMEMBERED_SET;
-    SaveFPRegsMode const save_fp_mode =
-        frame()->DidAllocateDoubleRegisters() ? kSaveFPRegs : kDontSaveFPRegs;
+        mode_ > RecordWriteMode::kValueIsMap ? RememberedSetAction::kEmit
+                                             : RememberedSetAction::kOmit;
+    SaveFPRegsMode const save_fp_mode = frame()->DidAllocateDoubleRegisters()
+                                            ? SaveFPRegsMode::kSave
+                                            : SaveFPRegsMode::kIgnore;
 
     if (mode_ == RecordWriteMode::kValueIsEphemeronKey) {
       __ CallEphemeronKeyBarrier(object_, scratch1_, save_fp_mode);
@@ -1016,7 +1014,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchSaveCallerRegisters: {
       fp_mode_ =
           static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode()));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // kReturnRegister0 should have been saved before entering the stub.
       int bytes = __ PushCallerSaved(fp_mode_, kReturnRegister0);
       DCHECK(IsAligned(bytes, kSystemPointerSize));
@@ -1029,7 +1028,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchRestoreCallerRegisters: {
       DCHECK(fp_mode_ ==
              static_cast<SaveFPRegsMode>(MiscField::decode(instr->opcode())));
-      DCHECK(fp_mode_ == kDontSaveFPRegs || fp_mode_ == kSaveFPRegs);
+      DCHECK(fp_mode_ == SaveFPRegsMode::kIgnore ||
+             fp_mode_ == SaveFPRegsMode::kSave);
       // Don't overwrite the returned value.
       int bytes = __ PopCallerSaved(fp_mode_, kReturnRegister0);
       frame_access_state()->IncreaseSPDelta(-(bytes / kSystemPointerSize));
@@ -1190,6 +1190,9 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                                                    scratch0, scratch1, mode,
                                                    DetermineStubCallMode());
       __ StoreTaggedField(operand, value);
+      if (mode > RecordWriteMode::kValueIsPointer) {
+        __ JumpIfSmi(value, ool->exit());
+      }
       __ CheckPageFlag(object, scratch0,
                        MemoryChunk::kPointersFromHereAreInterestingMask,
                        not_zero, ool->entry());
@@ -1478,7 +1481,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       // TODO(bmeurer): Use RIP relative 128-bit constants.
       XMMRegister tmp = i.ToDoubleRegister(instr->TempAt(0));
       __ Pcmpeqd(tmp, tmp);
-      __ Psrlq(tmp, 33);
+      __ Psrlq(tmp, byte{33});
       __ Andps(i.OutputDoubleRegister(), tmp);
       break;
     }
@@ -1486,7 +1489,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       // TODO(bmeurer): Use RIP relative 128-bit constants.
       XMMRegister tmp = i.ToDoubleRegister(instr->TempAt(0));
       __ Pcmpeqd(tmp, tmp);
-      __ Psllq(tmp, 31);
+      __ Psllq(tmp, byte{31});
       __ Xorps(i.OutputDoubleRegister(), tmp);
       break;
     }
@@ -1734,7 +1737,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
         __ Cvttss2siq(i.OutputRegister(), i.InputOperand(0));
       }
       if (instr->OutputCount() > 1) {
-        __ Set(i.OutputRegister(1), 1);
+        __ Move(i.OutputRegister(1), 1);
         Label done;
         Label fail;
         __ Move(kScratchDoubleReg, static_cast<float>(INT64_MIN));
@@ -1752,7 +1755,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
         // INT64_MIN, then the conversion fails.
         __ j(no_overflow, &done, Label::kNear);
         __ bind(&fail);
-        __ Set(i.OutputRegister(1), 0);
+        __ Move(i.OutputRegister(1), 0);
         __ bind(&done);
       }
       break;
@@ -1763,7 +1766,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
         __ Cvttsd2siq(i.OutputRegister(0), i.InputOperand(0));
       }
       if (instr->OutputCount() > 1) {
-        __ Set(i.OutputRegister(1), 1);
+        __ Move(i.OutputRegister(1), 1);
         Label done;
         Label fail;
         __ Move(kScratchDoubleReg, static_cast<double>(INT64_MIN));
@@ -1781,31 +1784,31 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
         // INT64_MIN, then the conversion fails.
         __ j(no_overflow, &done, Label::kNear);
         __ bind(&fail);
-        __ Set(i.OutputRegister(1), 0);
+        __ Move(i.OutputRegister(1), 0);
         __ bind(&done);
       }
       break;
     case kSSEFloat32ToUint64: {
       Label fail;
-      if (instr->OutputCount() > 1) __ Set(i.OutputRegister(1), 0);
+      if (instr->OutputCount() > 1) __ Move(i.OutputRegister(1), 0);
       if (instr->InputAt(0)->IsFPRegister()) {
         __ Cvttss2uiq(i.OutputRegister(), i.InputDoubleRegister(0), &fail);
       } else {
         __ Cvttss2uiq(i.OutputRegister(), i.InputOperand(0), &fail);
       }
-      if (instr->OutputCount() > 1) __ Set(i.OutputRegister(1), 1);
+      if (instr->OutputCount() > 1) __ Move(i.OutputRegister(1), 1);
       __ bind(&fail);
       break;
     }
     case kSSEFloat64ToUint64: {
       Label fail;
-      if (instr->OutputCount() > 1) __ Set(i.OutputRegister(1), 0);
+      if (instr->OutputCount() > 1) __ Move(i.OutputRegister(1), 0);
       if (instr->InputAt(0)->IsFPRegister()) {
         __ Cvttsd2uiq(i.OutputRegister(), i.InputDoubleRegister(0), &fail);
       } else {
         __ Cvttsd2uiq(i.OutputRegister(), i.InputOperand(0), &fail);
       }
-      if (instr->OutputCount() > 1) __ Set(i.OutputRegister(1), 1);
+      if (instr->OutputCount() > 1) __ Move(i.OutputRegister(1), 1);
       __ bind(&fail);
       break;
     }
@@ -2390,21 +2393,13 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kX64F64x2ExtractLane: {
-      DoubleRegister dst = i.OutputDoubleRegister();
-      XMMRegister src = i.InputSimd128Register(0);
-      uint8_t lane = i.InputUint8(1);
-      if (lane == 0) {
-        __ Move(dst, src);
-      } else {
-        DCHECK_EQ(1, lane);
-        if (CpuFeatures::IsSupported(AVX)) {
-          CpuFeatureScope avx_scope(tasm(), AVX);
-          // Pass src as operand to avoid false-dependency on dst.
-          __ vmovhlps(dst, src, src);
-        } else {
-          __ movhlps(dst, src);
-        }
-      }
+      __ F64x2ExtractLane(i.OutputDoubleRegister(), i.InputDoubleRegister(0),
+                          i.InputUint8(1));
+      break;
+    }
+    case kX64F64x2ReplaceLane: {
+      __ F64x2ReplaceLane(i.OutputSimd128Register(), i.InputSimd128Register(0),
+                          i.InputDoubleRegister(2), i.InputInt8(1));
       break;
     }
     case kX64F64x2Sqrt: {
@@ -2428,42 +2423,17 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kX64F64x2Min: {
-      XMMRegister src1 = i.InputSimd128Register(1),
-                  dst = i.OutputSimd128Register();
-      DCHECK_EQ(dst, i.InputSimd128Register(0));
-      // The minpd instruction doesn't propagate NaNs and +0's in its first
-      // operand. Perform minpd in both orders, merge the resuls, and adjust.
-      __ Movapd(kScratchDoubleReg, src1);
-      __ Minpd(kScratchDoubleReg, dst);
-      __ Minpd(dst, src1);
-      // propagate -0's and NaNs, which may be non-canonical.
-      __ Orpd(kScratchDoubleReg, dst);
-      // Canonicalize NaNs by quieting and clearing the payload.
-      __ Cmppd(dst, kScratchDoubleReg, int8_t{3});
-      __ Orpd(kScratchDoubleReg, dst);
-      __ Psrlq(dst, 13);
-      __ Andnpd(dst, kScratchDoubleReg);
+      // Avoids a move in no-AVX case if dst = src0.
+      DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      __ F64x2Min(i.OutputSimd128Register(), i.InputSimd128Register(0),
+                  i.InputSimd128Register(1), kScratchDoubleReg);
       break;
     }
     case kX64F64x2Max: {
-      XMMRegister src1 = i.InputSimd128Register(1),
-                  dst = i.OutputSimd128Register();
-      DCHECK_EQ(dst, i.InputSimd128Register(0));
-      // The maxpd instruction doesn't propagate NaNs and +0's in its first
-      // operand. Perform maxpd in both orders, merge the resuls, and adjust.
-      __ Movapd(kScratchDoubleReg, src1);
-      __ Maxpd(kScratchDoubleReg, dst);
-      __ Maxpd(dst, src1);
-      // Find discrepancies.
-      __ Xorpd(dst, kScratchDoubleReg);
-      // Propagate NaNs, which may be non-canonical.
-      __ Orpd(kScratchDoubleReg, dst);
-      // Propagate sign discrepancy and (subtle) quiet NaNs.
-      __ Subpd(kScratchDoubleReg, dst);
-      // Canonicalize NaNs by clearing the payload. Sign is non-deterministic.
-      __ Cmppd(dst, kScratchDoubleReg, int8_t{3});
-      __ Psrlq(dst, 13);
-      __ Andnpd(dst, kScratchDoubleReg);
+      // Avoids a move in no-AVX case if dst = src0.
+      DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      __ F64x2Max(i.OutputSimd128Register(), i.InputSimd128Register(0),
+                  i.InputSimd128Register(1), kScratchDoubleReg);
       break;
     }
     case kX64F64x2Eq: {
@@ -2534,43 +2504,12 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kX64F32x4Splat: {
-      XMMRegister dst = i.OutputSimd128Register();
-      XMMRegister src = i.InputDoubleRegister(0);
-      if (CpuFeatures::IsSupported(AVX2)) {
-        CpuFeatureScope avx2_scope(tasm(), AVX2);
-        __ vbroadcastss(dst, src);
-      } else if (CpuFeatures::IsSupported(AVX)) {
-        CpuFeatureScope avx_scope(tasm(), AVX);
-        __ vshufps(dst, src, src, 0);
-      } else {
-        if (dst == src) {
-          // 1 byte shorter than pshufd.
-          __ shufps(dst, src, 0);
-        } else {
-          __ pshufd(dst, src, 0);
-        }
-      }
+      __ F32x4Splat(i.OutputSimd128Register(), i.InputDoubleRegister(0));
       break;
     }
     case kX64F32x4ExtractLane: {
-      XMMRegister dst = i.OutputDoubleRegister();
-      XMMRegister src = i.InputSimd128Register(0);
-      uint8_t lane = i.InputUint8(1);
-      DCHECK_LT(lane, 4);
-      // These instructions are shorter than insertps, but will leave junk in
-      // the top lanes of dst.
-      if (lane == 0) {
-        __ Move(dst, src);
-      } else if (lane == 1) {
-        __ Movshdup(dst, src);
-      } else if (lane == 2 && dst == src) {
-        // Check dst == src to avoid false dependency on dst.
-        __ Movhlps(dst, src);
-      } else if (dst == src) {
-        __ Shufps(dst, src, src, lane);
-      } else {
-        __ Pshufd(dst, src, lane);
-      }
+      __ F32x4ExtractLane(i.OutputFloatRegister(), i.InputSimd128Register(0),
+                          i.InputUint8(1));
       break;
     }
     case kX64F32x4ReplaceLane: {
@@ -2671,7 +2610,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       // propagate -0's and NaNs, which may be non-canonical.
       __ Orps(kScratchDoubleReg, dst);
       // Canonicalize NaNs by quieting and clearing the payload.
-      __ Cmpps(dst, kScratchDoubleReg, int8_t{3});
+      __ Cmpunordps(dst, kScratchDoubleReg);
       __ Orps(kScratchDoubleReg, dst);
       __ Psrld(dst, byte{10});
       __ Andnps(dst, kScratchDoubleReg);
@@ -2693,7 +2632,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       // Propagate sign discrepancy and (subtle) quiet NaNs.
       __ Subps(kScratchDoubleReg, dst);
       // Canonicalize NaNs by clearing the payload. Sign is non-deterministic.
-      __ Cmpps(dst, kScratchDoubleReg, int8_t{3});
+      __ Cmpunordps(dst, kScratchDoubleReg);
       __ Psrld(dst, byte{10});
       __ Andnps(dst, kScratchDoubleReg);
       break;
@@ -2786,14 +2725,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kX64I64x2Neg: {
-      XMMRegister dst = i.OutputSimd128Register();
-      XMMRegister src = i.InputSimd128Register(0);
-      if (dst == src) {
-        __ Movdqa(kScratchDoubleReg, src);
-        src = kScratchDoubleReg;
-      }
-      __ Pxor(dst, dst);
-      __ Psubq(dst, src);
+      __ I64x2Neg(i.OutputSimd128Register(), i.InputSimd128Register(0),
+                  kScratchDoubleReg);
       break;
     }
     case kX64I64x2BitMask: {
@@ -2843,15 +2776,15 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ Movdqa(tmp2, right);
 
       // Multiply high dword of each qword of left with right.
-      __ Psrlq(tmp1, 32);
+      __ Psrlq(tmp1, byte{32});
       __ Pmuludq(tmp1, right);
 
       // Multiply high dword of each qword of right with left.
-      __ Psrlq(tmp2, 32);
+      __ Psrlq(tmp2, byte{32});
       __ Pmuludq(tmp2, left);
 
       __ Paddq(tmp2, tmp1);
-      __ Psllq(tmp2, 32);
+      __ Psllq(tmp2, byte{32});
 
       __ Pmuludq(left, right);
       __ Paddq(left, tmp2);  // left == dst
@@ -3675,15 +3608,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kX64S128Not: {
-      XMMRegister dst = i.OutputSimd128Register();
-      XMMRegister src = i.InputSimd128Register(0);
-      if (dst == src) {
-        __ Pcmpeqd(kScratchDoubleReg, kScratchDoubleReg);
-        __ Pxor(dst, kScratchDoubleReg);
-      } else {
-        __ Pcmpeqd(dst, dst);
-        __ Pxor(dst, src);
-      }
+      __ S128Not(i.OutputSimd128Register(), i.InputSimd128Register(0),
+                 kScratchDoubleReg);
       break;
     }
     case kX64S128Select: {
@@ -4360,7 +4286,7 @@ void CodeGenerator::AssembleArchDeoptBranch(Instruction* instr,
     __ decl(rax);
     __ j(not_zero, &nodeopt, Label::kNear);
 
-    __ Set(rax, FLAG_deopt_every_n_times);
+    __ Move(rax, FLAG_deopt_every_n_times);
     __ store_rax(counter);
     __ popq(rax);
     __ popfq();
@@ -4451,7 +4377,43 @@ void CodeGenerator::AssembleArchTableSwitch(Instruction* instr) {
 
 void CodeGenerator::AssembleArchSelect(Instruction* instr,
                                        FlagsCondition condition) {
-  UNIMPLEMENTED();
+  X64OperandConverter i(this, instr);
+  MachineRepresentation rep =
+      LocationOperand::cast(instr->OutputAt(0))->representation();
+  Condition cc = FlagsConditionToCondition(condition);
+  DCHECK_EQ(i.OutputRegister(), i.InputRegister(instr->InputCount() - 2));
+  size_t last_input = instr->InputCount() - 1;
+  // kUnorderedNotEqual can be implemented more efficiently than
+  // kUnorderedEqual. As the OR of two flags, it can be done with just two
+  // cmovs. If the condition was originally a kUnorderedEqual, expect the
+  // instruction selector to have inverted it and swapped the input.
+  DCHECK_NE(condition, kUnorderedEqual);
+  if (rep == MachineRepresentation::kWord32) {
+    if (HasRegisterInput(instr, last_input)) {
+      __ cmovl(cc, i.OutputRegister(), i.InputRegister(last_input));
+      if (condition == kUnorderedNotEqual) {
+        __ cmovl(parity_even, i.OutputRegister(), i.InputRegister(last_input));
+      }
+    } else {
+      __ cmovl(cc, i.OutputRegister(), i.InputOperand(last_input));
+      if (condition == kUnorderedNotEqual) {
+        __ cmovl(parity_even, i.OutputRegister(), i.InputOperand(last_input));
+      }
+    }
+  } else {
+    DCHECK_EQ(rep, MachineRepresentation::kWord64);
+    if (HasRegisterInput(instr, last_input)) {
+      __ cmovq(cc, i.OutputRegister(), i.InputRegister(last_input));
+      if (condition == kUnorderedNotEqual) {
+        __ cmovq(parity_even, i.OutputRegister(), i.InputRegister(last_input));
+      }
+    } else {
+      __ cmovq(cc, i.OutputRegister(), i.InputOperand(last_input));
+      if (condition == kUnorderedNotEqual) {
+        __ cmovq(parity_even, i.OutputRegister(), i.InputOperand(last_input));
+      }
+    }
+  }
 }
 
 namespace {
@@ -4464,13 +4426,11 @@ void CodeGenerator::FinishFrame(Frame* frame) {
   CallDescriptor* call_descriptor = linkage()->GetIncomingDescriptor();
 
   const RegList saves_fp = call_descriptor->CalleeSavedFPRegisters();
-  if (saves_fp != 0) {
+  if (saves_fp != 0) {  // Save callee-saved XMM registers.
     frame->AlignSavedCalleeRegisterSlots();
-    if (saves_fp != 0) {  // Save callee-saved XMM registers.
-      const uint32_t saves_fp_count = base::bits::CountPopulation(saves_fp);
-      frame->AllocateSavedCalleeRegisterSlots(
-          saves_fp_count * (kQuadWordSize / kSystemPointerSize));
-    }
+    const uint32_t saves_fp_count = base::bits::CountPopulation(saves_fp);
+    frame->AllocateSavedCalleeRegisterSlots(
+        saves_fp_count * (kQuadWordSize / kSystemPointerSize));
   }
   const RegList saves = call_descriptor->CalleeSavedRegisters();
   if (saves != 0) {  // Save callee-saved registers.
@@ -4540,7 +4500,7 @@ void CodeGenerator::AssembleConstructFrame() {
     // frame is still on the stack. Optimized code uses OSR values directly from
     // the unoptimized frame. Thus, all that needs to be done is to allocate the
     // remaining stack slots.
-    if (FLAG_code_comments) __ RecordComment("-- OSR entrypoint --");
+    __ RecordComment("-- OSR entrypoint --");
     osr_pc_offset_ = __ pc_offset();
     required_slots -= static_cast<int>(osr_helper()->UnoptimizedFrameSlots());
     ResetSpeculationPoison();
@@ -4664,7 +4624,7 @@ void CodeGenerator::AssembleReturn(InstructionOperand* additional_pop_count) {
   if (parameter_slots != 0) {
     if (additional_pop_count->IsImmediate()) {
       DCHECK_EQ(g.ToConstant(additional_pop_count).ToInt32(), 0);
-    } else if (__ emit_debug_code()) {
+    } else if (FLAG_debug_code) {
       __ cmpq(g.ToRegister(additional_pop_count), Immediate(0));
       __ Assert(equal, AbortReason::kUnexpectedAdditionalPopValue);
     }
@@ -4787,7 +4747,7 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
         if (RelocInfo::IsWasmReference(src.rmode())) {
           __ movq(dst, Immediate64(src.ToInt64(), src.rmode()));
         } else {
-          __ Set(dst, src.ToInt64());
+          __ Move(dst, src.ToInt64());
         }
         break;
       case Constant::kFloat32:
@@ -4837,7 +4797,7 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
           __ movq(dst, Immediate(src.ToInt32()));
           return;
         case Constant::kInt64:
-          __ Set(dst, src.ToInt64());
+          __ Move(dst, src.ToInt64());
           return;
         default:
           break;
diff --git a/chromium/v8/src/compiler/backend/x64/instruction-codes-x64.h b/chromium/v8/src/compiler/backend/x64/instruction-codes-x64.h
index 2ad717c0a04..eba23dcfa92 100644
--- a/chromium/v8/src/compiler/backend/x64/instruction-codes-x64.h
+++ b/chromium/v8/src/compiler/backend/x64/instruction-codes-x64.h
@@ -156,6 +156,7 @@ namespace compiler {
   V(X64Peek)                              \
   V(X64F64x2Splat)                        \
   V(X64F64x2ExtractLane)                  \
+  V(X64F64x2ReplaceLane)                  \
   V(X64F64x2Abs)                          \
   V(X64F64x2Neg)                          \
   V(X64F64x2Sqrt)                         \
diff --git a/chromium/v8/src/compiler/backend/x64/instruction-scheduler-x64.cc b/chromium/v8/src/compiler/backend/x64/instruction-scheduler-x64.cc
index dc323d4cc79..4fada93a312 100644
--- a/chromium/v8/src/compiler/backend/x64/instruction-scheduler-x64.cc
+++ b/chromium/v8/src/compiler/backend/x64/instruction-scheduler-x64.cc
@@ -132,6 +132,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kX64Pinsrq:
     case kX64F64x2Splat:
     case kX64F64x2ExtractLane:
+    case kX64F64x2ReplaceLane:
     case kX64F64x2Abs:
     case kX64F64x2Neg:
     case kX64F64x2Sqrt:
diff --git a/chromium/v8/src/compiler/backend/x64/instruction-selector-x64.cc b/chromium/v8/src/compiler/backend/x64/instruction-selector-x64.cc
index 23bbed36137..40eddf31316 100644
--- a/chromium/v8/src/compiler/backend/x64/instruction-selector-x64.cc
+++ b/chromium/v8/src/compiler/backend/x64/instruction-selector-x64.cc
@@ -66,7 +66,8 @@ class X64OperandGenerator final : public OperandGenerator {
 
   bool CanBeMemoryOperand(InstructionCode opcode, Node* node, Node* input,
                           int effect_level) {
-    if (input->opcode() != IrOpcode::kLoad ||
+    if ((input->opcode() != IrOpcode::kLoad &&
+         input->opcode() != IrOpcode::kLoadImmutable) ||
         !selector()->CanCover(node, input)) {
       return false;
     }
@@ -298,6 +299,7 @@ ArchOpcode GetLoadOpcode(LoadRepresentation load_rep) {
       opcode = kX64Movdqu;
       break;
     case MachineRepresentation::kNone:
+    case MachineRepresentation::kMapWord:
       UNREACHABLE();
   }
   return opcode;
@@ -332,6 +334,7 @@ ArchOpcode GetStoreOpcode(StoreRepresentation store_rep) {
     case MachineRepresentation::kSimd128:  // Fall through.
       return kX64Movdqu;
     case MachineRepresentation::kNone:
+    case MachineRepresentation::kMapWord:
       UNREACHABLE();
   }
   UNREACHABLE();
@@ -465,6 +468,7 @@ void InstructionSelector::VisitLoad(Node* node, Node* value,
 
 void InstructionSelector::VisitLoad(Node* node) {
   LoadRepresentation load_rep = LoadRepresentationOf(node->op());
+  DCHECK(!load_rep.IsMapWord());
   VisitLoad(node, node, GetLoadOpcode(load_rep));
 }
 
@@ -479,6 +483,7 @@ void InstructionSelector::VisitStore(Node* node) {
   Node* value = node->InputAt(2);
 
   StoreRepresentation store_rep = StoreRepresentationOf(node->op());
+  DCHECK_NE(store_rep.representation(), MachineRepresentation::kMapWord);
   WriteBarrierKind write_barrier_kind = store_rep.write_barrier_kind();
 
   if (FLAG_enable_unconditional_write_barriers &&
@@ -704,7 +709,8 @@ void InstructionSelector::VisitStackPointerGreaterThan(
   X64OperandGenerator g(this);
   Node* const value = node->InputAt(0);
   if (g.CanBeMemoryOperand(kX64Cmp, node, value, effect_level)) {
-    DCHECK_EQ(IrOpcode::kLoad, value->opcode());
+    DCHECK(IrOpcode::kLoad == value->opcode() ||
+           IrOpcode::kLoadImmutable == value->opcode());
 
     // GetEffectiveAddressMemoryOperand can create at most 3 inputs.
     static constexpr int kMaxInputCount = 3;
@@ -726,7 +732,9 @@ namespace {
 
 bool TryMergeTruncateInt64ToInt32IntoLoad(InstructionSelector* selector,
                                           Node* node, Node* load) {
-  if (load->opcode() == IrOpcode::kLoad && selector->CanCover(node, load)) {
+  if ((load->opcode() == IrOpcode::kLoad ||
+       load->opcode() == IrOpcode::kLoadImmutable) &&
+      selector->CanCover(node, load)) {
     LoadRepresentation load_rep = LoadRepresentationOf(load->op());
     MachineRepresentation rep = load_rep.representation();
     InstructionCode opcode;
@@ -1363,7 +1371,9 @@ void InstructionSelector::VisitChangeInt32ToInt64(Node* node) {
 
   X64OperandGenerator g(this);
   Node* const value = node->InputAt(0);
-  if (value->opcode() == IrOpcode::kLoad && CanCover(node, value)) {
+  if ((value->opcode() == IrOpcode::kLoad ||
+       value->opcode() == IrOpcode::kLoadImmutable) &&
+      CanCover(node, value)) {
     LoadRepresentation load_rep = LoadRepresentationOf(value->op());
     MachineRepresentation rep = load_rep.representation();
     InstructionCode opcode;
@@ -1870,14 +1880,25 @@ void VisitCompareWithMemoryOperand(InstructionSelector* selector,
                                    InstructionCode opcode, Node* left,
                                    InstructionOperand right,
                                    FlagsContinuation* cont) {
-  DCHECK_EQ(IrOpcode::kLoad, left->opcode());
+  DCHECK(IrOpcode::kLoad == left->opcode() ||
+         IrOpcode::kLoadImmutable == left->opcode());
   X64OperandGenerator g(selector);
   size_t input_count = 0;
-  InstructionOperand inputs[4];
+  InstructionOperand inputs[6];
   AddressingMode addressing_mode =
       g.GetEffectiveAddressMemoryOperand(left, inputs, &input_count);
   opcode |= AddressingModeField::encode(addressing_mode);
   inputs[input_count++] = right;
+  if (cont->IsSelect()) {
+    if (opcode == kUnorderedEqual) {
+      cont->Negate();
+      inputs[input_count++] = g.UseRegister(cont->true_value());
+      inputs[input_count++] = g.Use(cont->false_value());
+    } else {
+      inputs[input_count++] = g.UseRegister(cont->false_value());
+      inputs[input_count++] = g.Use(cont->true_value());
+    }
+  }
 
   selector->EmitWithContinuation(opcode, 0, nullptr, input_count, inputs, cont);
 }
@@ -1886,6 +1907,20 @@ void VisitCompareWithMemoryOperand(InstructionSelector* selector,
 void VisitCompare(InstructionSelector* selector, InstructionCode opcode,
                   InstructionOperand left, InstructionOperand right,
                   FlagsContinuation* cont) {
+  if (cont->IsSelect()) {
+    X64OperandGenerator g(selector);
+    InstructionOperand inputs[4] = {left, right};
+    if (cont->condition() == kUnorderedEqual) {
+      cont->Negate();
+      inputs[2] = g.UseRegister(cont->true_value());
+      inputs[3] = g.Use(cont->false_value());
+    } else {
+      inputs[2] = g.UseRegister(cont->false_value());
+      inputs[3] = g.Use(cont->true_value());
+    }
+    selector->EmitWithContinuation(opcode, 0, nullptr, 4, inputs, cont);
+    return;
+  }
   selector->EmitWithContinuation(opcode, left, right, cont);
 }
 
@@ -1901,7 +1936,8 @@ void VisitCompare(InstructionSelector* selector, InstructionCode opcode,
 }
 
 MachineType MachineTypeForNarrow(Node* node, Node* hint_node) {
-  if (hint_node->opcode() == IrOpcode::kLoad) {
+  if (hint_node->opcode() == IrOpcode::kLoad ||
+      hint_node->opcode() == IrOpcode::kLoadImmutable) {
     MachineType hint = LoadRepresentationOf(hint_node->op());
     if (node->opcode() == IrOpcode::kInt32Constant ||
         node->opcode() == IrOpcode::kInt64Constant) {
@@ -1935,8 +1971,10 @@ MachineType MachineTypeForNarrow(Node* node, Node* hint_node) {
       }
     }
   }
-  return node->opcode() == IrOpcode::kLoad ? LoadRepresentationOf(node->op())
-                                           : MachineType::None();
+  return node->opcode() == IrOpcode::kLoad ||
+                 node->opcode() == IrOpcode::kLoadImmutable
+             ? LoadRepresentationOf(node->op())
+             : MachineType::None();
 }
 
 // Tries to match the size of the given opcode to that of the operands, if
@@ -2151,7 +2189,8 @@ void VisitCompareZero(InstructionSelector* selector, Node* user, Node* node,
     }
   }
   int effect_level = selector->GetEffectLevel(node, cont);
-  if (node->opcode() == IrOpcode::kLoad) {
+  if (node->opcode() == IrOpcode::kLoad ||
+      node->opcode() == IrOpcode::kLoadImmutable) {
     switch (LoadRepresentationOf(node->op()).representation()) {
       case MachineRepresentation::kWord8:
         if (opcode == kX64Cmp32) {
@@ -2920,7 +2959,6 @@ VISIT_ATOMIC_BINOP(Xor)
   V(F32x4RecipApprox)       \
   V(F32x4RecipSqrtApprox)   \
   V(F32x4DemoteF64x2Zero)   \
-  V(I64x2Neg)               \
   V(I64x2BitMask)           \
   V(I64x2SConvertI32x4Low)  \
   V(I64x2SConvertI32x4High) \
@@ -3045,6 +3083,16 @@ void InstructionSelector::VisitF32x4ReplaceLane(Node* node) {
        g.Use(node->InputAt(1)));
 }
 
+void InstructionSelector::VisitF64x2ReplaceLane(Node* node) {
+  X64OperandGenerator g(this);
+  int32_t lane = OpParameter<int32_t>(node->op());
+  // When no-AVX, define dst == src to save a move.
+  InstructionOperand dst =
+      IsSupported(AVX) ? g.DefineAsRegister(node) : g.DefineSameAsFirst(node);
+  Emit(kX64F64x2ReplaceLane, dst, g.UseRegister(node->InputAt(0)),
+       g.UseImmediate(lane), g.UseRegister(node->InputAt(1)));
+}
+
 #define VISIT_SIMD_REPLACE_LANE(TYPE, OPCODE)                               \
   void InstructionSelector::Visit##TYPE##ReplaceLane(Node* node) {          \
     X64OperandGenerator g(this);                                            \
@@ -3054,7 +3102,6 @@ void InstructionSelector::VisitF32x4ReplaceLane(Node* node) {
   }
 
 #define SIMD_TYPES_FOR_REPLACE_LANE(V) \
-  V(F64x2, kX64Pinsrq)                 \
   V(I64x2, kX64Pinsrq)                 \
   V(I32x4, kX64Pinsrd)                 \
   V(I16x8, kX64Pinsrw)                 \
@@ -3186,6 +3233,15 @@ VISIT_SIMD_QFMOP(F32x4Qfma)
 VISIT_SIMD_QFMOP(F32x4Qfms)
 #undef VISIT_SIMD_QFMOP
 
+void InstructionSelector::VisitI64x2Neg(Node* node) {
+  X64OperandGenerator g(this);
+  // If AVX unsupported, make sure dst != src to avoid a move.
+  InstructionOperand operand0 = IsSupported(AVX)
+                                    ? g.UseRegister(node->InputAt(0))
+                                    : g.UseUnique(node->InputAt(0));
+  Emit(kX64I64x2Neg, g.DefineAsRegister(node), operand0);
+}
+
 void InstructionSelector::VisitI64x2ShrS(Node* node) {
   X64OperandGenerator g(this);
   InstructionOperand temps[] = {g.TempRegister()};
@@ -3707,13 +3763,22 @@ void InstructionSelector::VisitI64x2Abs(Node* node) {
   }
 }
 
+void InstructionSelector::AddOutputToSelectContinuation(OperandGenerator* g,
+                                                        int first_input_index,
+                                                        Node* node) {
+  continuation_outputs_.push_back(
+      g->DefineSameAsInput(node, first_input_index));
+}
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
   MachineOperatorBuilder::Flags flags =
       MachineOperatorBuilder::kWord32ShiftIsSafe |
       MachineOperatorBuilder::kWord32Ctz | MachineOperatorBuilder::kWord64Ctz |
-      MachineOperatorBuilder::kWord32Rol | MachineOperatorBuilder::kWord64Rol;
+      MachineOperatorBuilder::kWord32Rol | MachineOperatorBuilder::kWord64Rol |
+      MachineOperatorBuilder::kWord32Select |
+      MachineOperatorBuilder::kWord64Select;
   if (CpuFeatures::IsSupported(POPCNT)) {
     flags |= MachineOperatorBuilder::kWord32Popcnt |
              MachineOperatorBuilder::kWord64Popcnt;
diff --git a/chromium/v8/src/compiler/bytecode-graph-builder.cc b/chromium/v8/src/compiler/bytecode-graph-builder.cc
index 54996bb4755..faae9c1eab0 100644
--- a/chromium/v8/src/compiler/bytecode-graph-builder.cc
+++ b/chromium/v8/src/compiler/bytecode-graph-builder.cc
@@ -27,7 +27,7 @@
 #include "src/objects/literal-objects-inl.h"
 #include "src/objects/objects-inl.h"
 #include "src/objects/smi.h"
-#include "src/objects/template-objects.h"
+#include "src/objects/template-objects-inl.h"
 
 namespace v8 {
 namespace internal {
@@ -72,7 +72,8 @@ class BytecodeGraphBuilder {
 
   CodeKind code_kind() const { return code_kind_; }
   bool native_context_independent() const {
-    return CodeKindIsNativeContextIndependentJSFunction(code_kind_);
+    // TODO(jgruber,v8:8888): Remove dependent code.
+    return false;
   }
   bool is_turboprop() const { return code_kind_ == CodeKind::TURBOPROP; }
   bool generate_full_feedback_collection() const {
@@ -346,6 +347,10 @@ class BytecodeGraphBuilder {
   // feedback. Returns kDisallowSpeculation if feedback is insufficient.
   SpeculationMode GetSpeculationMode(int slot_id) const;
 
+  // Helper function to determine the call feedback relation from the recorded
+  // type feedback. Returns kUnrelated if feedback is insufficient.
+  CallFeedbackRelation ComputeCallFeedbackRelation(int slot_id) const;
+
   // Helpers for building the implicit FunctionEntry and IterationBody
   // StackChecks.
   void BuildFunctionEntryStackCheck();
@@ -412,10 +417,15 @@ class BytecodeGraphBuilder {
     int context_register_;  // Index of register holding handler context.
   };
 
-  Handle<Object> GetConstantForIndexOperand(int operand_index) const {
-    return broker_->CanonicalPersistentHandle(
-        bytecode_iterator().GetConstantForIndexOperand(operand_index,
-                                                       local_isolate_));
+  template <class T = Object>
+  typename ref_traits<T>::ref_type MakeRefForConstantForIndexOperand(
+      int operand_index) {
+    // The BytecodeArray itself was fetched by using a barrier so all reads
+    // from the constant pool are safe.
+    return MakeRefAssumeMemoryFence(
+        broker(), broker()->CanonicalPersistentHandle(Handle<T>::cast(
+                      bytecode_iterator().GetConstantForIndexOperand(
+                          operand_index, local_isolate_))));
   }
 
   Graph* graph() const { return jsgraph_->graph(); }
@@ -428,9 +438,7 @@ class BytecodeGraphBuilder {
     return jsgraph_->simplified();
   }
   Zone* local_zone() const { return local_zone_; }
-  BytecodeArrayRef bytecode_array() const {
-    return shared_info().GetBytecodeArray();
-  }
+  BytecodeArrayRef bytecode_array() const { return bytecode_array_; }
   FeedbackVectorRef const& feedback_vector() const { return feedback_vector_; }
   const JSTypeHintLowering& type_hint_lowering() const {
     return type_hint_lowering_;
@@ -480,6 +488,7 @@ class BytecodeGraphBuilder {
   // The native context for which we optimize.
   NativeContextRef const native_context_;
   SharedFunctionInfoRef const shared_info_;
+  BytecodeArrayRef const bytecode_array_;
   FeedbackCellRef const feedback_cell_;
   FeedbackVectorRef const feedback_vector_;
   CallFrequency const invocation_frequency_;
@@ -1065,6 +1074,7 @@ BytecodeGraphBuilder::BytecodeGraphBuilder(
       jsgraph_(jsgraph),
       native_context_(native_context),
       shared_info_(shared_info),
+      bytecode_array_(shared_info.GetBytecodeArray()),
       feedback_cell_(feedback_cell),
       feedback_vector_(feedback_cell.value()->AsFeedbackVector()),
       invocation_frequency_(invocation_frequency),
@@ -1569,7 +1579,7 @@ void BytecodeGraphBuilder::VisitBytecodes() {
   }
 
   // TODO(leszeks): Increment usage counter on BG thread.
-  if (!FLAG_concurrent_inlining && has_one_shot_bytecode) {
+  if (!broker()->is_concurrent_inlining() && has_one_shot_bytecode) {
     // (For concurrent inlining this is done in the serializer instead.)
     isolate()->CountUsage(
         v8::Isolate::UseCounterFeature::kOptimizedFunctionWithOneShotBytecode);
@@ -1589,8 +1599,7 @@ void BytecodeGraphBuilder::VisitLdaSmi() {
 }
 
 void BytecodeGraphBuilder::VisitLdaConstant() {
-  ObjectRef object(broker(), GetConstantForIndexOperand(0),
-                   ObjectRef::BackgroundSerialization::kAllowed);
+  ObjectRef object = MakeRefForConstantForIndexOperand(0);
   Node* node = jsgraph()->Constant(object);
   environment()->BindAccumulator(node);
 }
@@ -1660,25 +1669,24 @@ Node* BytecodeGraphBuilder::BuildLoadGlobal(NameRef name,
 
 void BytecodeGraphBuilder::VisitLdaGlobal() {
   PrepareEagerCheckpoint();
-  NameRef name(broker(), GetConstantForIndexOperand(0));
+  NameRef name = MakeRefForConstantForIndexOperand<Name>(0);
   uint32_t feedback_slot_index = bytecode_iterator().GetIndexOperand(1);
   Node* node =
-      BuildLoadGlobal(name, feedback_slot_index, TypeofMode::NOT_INSIDE_TYPEOF);
+      BuildLoadGlobal(name, feedback_slot_index, TypeofMode::kNotInside);
   environment()->BindAccumulator(node, Environment::kAttachFrameState);
 }
 
 void BytecodeGraphBuilder::VisitLdaGlobalInsideTypeof() {
   PrepareEagerCheckpoint();
-  NameRef name(broker(), GetConstantForIndexOperand(0));
+  NameRef name = MakeRefForConstantForIndexOperand<Name>(0);
   uint32_t feedback_slot_index = bytecode_iterator().GetIndexOperand(1);
-  Node* node =
-      BuildLoadGlobal(name, feedback_slot_index, TypeofMode::INSIDE_TYPEOF);
+  Node* node = BuildLoadGlobal(name, feedback_slot_index, TypeofMode::kInside);
   environment()->BindAccumulator(node, Environment::kAttachFrameState);
 }
 
 void BytecodeGraphBuilder::VisitStaGlobal() {
   PrepareEagerCheckpoint();
-  NameRef name(broker(), GetConstantForIndexOperand(0));
+  NameRef name = MakeRefForConstantForIndexOperand<Name>(0);
   FeedbackSource feedback =
       CreateFeedbackSource(bytecode_iterator().GetIndexOperand(1));
   Node* value = environment()->LookupAccumulator();
@@ -1819,10 +1827,9 @@ void BytecodeGraphBuilder::VisitStaCurrentContextSlot() {
 
 void BytecodeGraphBuilder::BuildLdaLookupSlot(TypeofMode typeof_mode) {
   PrepareEagerCheckpoint();
-  Node* name =
-      jsgraph()->Constant(ObjectRef(broker(), GetConstantForIndexOperand(0)));
+  Node* name = jsgraph()->Constant(MakeRefForConstantForIndexOperand(0));
   const Operator* op =
-      javascript()->CallRuntime(typeof_mode == TypeofMode::NOT_INSIDE_TYPEOF
+      javascript()->CallRuntime(typeof_mode == TypeofMode::kNotInside
                                     ? Runtime::kLoadLookupSlot
                                     : Runtime::kLoadLookupSlotInsideTypeof);
   Node* value = NewNode(op, name);
@@ -1830,11 +1837,11 @@ void BytecodeGraphBuilder::BuildLdaLookupSlot(TypeofMode typeof_mode) {
 }
 
 void BytecodeGraphBuilder::VisitLdaLookupSlot() {
-  BuildLdaLookupSlot(TypeofMode::NOT_INSIDE_TYPEOF);
+  BuildLdaLookupSlot(TypeofMode::kNotInside);
 }
 
 void BytecodeGraphBuilder::VisitLdaLookupSlotInsideTypeof() {
-  BuildLdaLookupSlot(TypeofMode::INSIDE_TYPEOF);
+  BuildLdaLookupSlot(TypeofMode::kInside);
 }
 
 BytecodeGraphBuilder::Environment*
@@ -1870,13 +1877,13 @@ base::Optional<ScopeInfoRef> BytecodeGraphBuilder::TryGetScopeInfo() {
   Node* context = environment()->Context();
   switch (context->opcode()) {
     case IrOpcode::kJSCreateFunctionContext:
-      return ScopeInfoRef(
+      return MakeRef(
           broker(),
           CreateFunctionContextParametersOf(context->op()).scope_info());
     case IrOpcode::kJSCreateBlockContext:
     case IrOpcode::kJSCreateCatchContext:
     case IrOpcode::kJSCreateWithContext:
-      return ScopeInfoRef(broker(), ScopeInfoOf(context->op()));
+      return MakeRef(broker(), ScopeInfoOf(context->op()));
     case IrOpcode::kParameter: {
       ScopeInfoRef scope_info = shared_info_.scope_info();
       if (scope_info.HasOuterScopeInfo()) {
@@ -1972,11 +1979,10 @@ void BytecodeGraphBuilder::BuildLdaLookupContextSlot(TypeofMode typeof_mode) {
     // Slow path, do a runtime load lookup.
     set_environment(slow_environment);
     {
-      Node* name = jsgraph()->Constant(
-          ObjectRef(broker(), GetConstantForIndexOperand(0)));
+      Node* name = jsgraph()->Constant(MakeRefForConstantForIndexOperand(0));
 
       const Operator* op =
-          javascript()->CallRuntime(typeof_mode == TypeofMode::NOT_INSIDE_TYPEOF
+          javascript()->CallRuntime(typeof_mode == TypeofMode::kNotInside
                                         ? Runtime::kLoadLookupSlot
                                         : Runtime::kLoadLookupSlotInsideTypeof);
       Node* value = NewNode(op, name);
@@ -1992,11 +1998,11 @@ void BytecodeGraphBuilder::BuildLdaLookupContextSlot(TypeofMode typeof_mode) {
 }
 
 void BytecodeGraphBuilder::VisitLdaLookupContextSlot() {
-  BuildLdaLookupContextSlot(TypeofMode::NOT_INSIDE_TYPEOF);
+  BuildLdaLookupContextSlot(TypeofMode::kNotInside);
 }
 
 void BytecodeGraphBuilder::VisitLdaLookupContextSlotInsideTypeof() {
-  BuildLdaLookupContextSlot(TypeofMode::INSIDE_TYPEOF);
+  BuildLdaLookupContextSlot(TypeofMode::kInside);
 }
 
 void BytecodeGraphBuilder::BuildLdaLookupGlobalSlot(TypeofMode typeof_mode) {
@@ -2008,7 +2014,7 @@ void BytecodeGraphBuilder::BuildLdaLookupGlobalSlot(TypeofMode typeof_mode) {
   // Fast path, do a global load.
   {
     PrepareEagerCheckpoint();
-    NameRef name(broker(), GetConstantForIndexOperand(0));
+    NameRef name = MakeRefForConstantForIndexOperand<Name>(0);
     uint32_t feedback_slot_index = bytecode_iterator().GetIndexOperand(1);
     Node* node = BuildLoadGlobal(name, feedback_slot_index, typeof_mode);
     environment()->BindAccumulator(node, Environment::kAttachFrameState);
@@ -2024,10 +2030,10 @@ void BytecodeGraphBuilder::BuildLdaLookupGlobalSlot(TypeofMode typeof_mode) {
     set_environment(slow_environment);
     {
       Node* name =
-          jsgraph()->Constant(NameRef(broker(), GetConstantForIndexOperand(0)));
+          jsgraph()->Constant(MakeRefForConstantForIndexOperand<Name>(0));
 
       const Operator* op =
-          javascript()->CallRuntime(typeof_mode == TypeofMode::NOT_INSIDE_TYPEOF
+          javascript()->CallRuntime(typeof_mode == TypeofMode::kNotInside
                                         ? Runtime::kLoadLookupSlot
                                         : Runtime::kLoadLookupSlotInsideTypeof);
       Node* value = NewNode(op, name);
@@ -2043,18 +2049,17 @@ void BytecodeGraphBuilder::BuildLdaLookupGlobalSlot(TypeofMode typeof_mode) {
 }
 
 void BytecodeGraphBuilder::VisitLdaLookupGlobalSlot() {
-  BuildLdaLookupGlobalSlot(TypeofMode::NOT_INSIDE_TYPEOF);
+  BuildLdaLookupGlobalSlot(TypeofMode::kNotInside);
 }
 
 void BytecodeGraphBuilder::VisitLdaLookupGlobalSlotInsideTypeof() {
-  BuildLdaLookupGlobalSlot(TypeofMode::INSIDE_TYPEOF);
+  BuildLdaLookupGlobalSlot(TypeofMode::kInside);
 }
 
 void BytecodeGraphBuilder::VisitStaLookupSlot() {
   PrepareEagerCheckpoint();
   Node* value = environment()->LookupAccumulator();
-  Node* name =
-      jsgraph()->Constant(ObjectRef(broker(), GetConstantForIndexOperand(0)));
+  Node* name = jsgraph()->Constant(MakeRefForConstantForIndexOperand(0));
   int bytecode_flags = bytecode_iterator().GetFlagOperand(1);
   LanguageMode language_mode = static_cast<LanguageMode>(
       interpreter::StoreLookupSlotFlags::LanguageModeBit::decode(
@@ -2078,7 +2083,7 @@ void BytecodeGraphBuilder::VisitLdaNamedProperty() {
   PrepareEagerCheckpoint();
   Node* object =
       environment()->LookupRegister(bytecode_iterator().GetRegisterOperand(0));
-  NameRef name(broker(), GetConstantForIndexOperand(1));
+  NameRef name = MakeRefForConstantForIndexOperand<Name>(1);
   FeedbackSource feedback =
       CreateFeedbackSource(bytecode_iterator().GetIndexOperand(2));
   const Operator* op = javascript()->LoadNamed(name.object(), feedback);
@@ -2102,7 +2107,7 @@ void BytecodeGraphBuilder::VisitLdaNamedPropertyNoFeedback() {
   PrepareEagerCheckpoint();
   Node* object =
       environment()->LookupRegister(bytecode_iterator().GetRegisterOperand(0));
-  NameRef name(broker(), GetConstantForIndexOperand(1));
+  NameRef name = MakeRefForConstantForIndexOperand<Name>(1);
   const Operator* op = javascript()->LoadNamed(name.object(), FeedbackSource());
   DCHECK(IrOpcode::IsFeedbackCollectingOpcode(op->opcode()));
   Node* node = NewNode(op, object, feedback_vector_node());
@@ -2114,7 +2119,7 @@ void BytecodeGraphBuilder::VisitLdaNamedPropertyFromSuper() {
   Node* receiver =
       environment()->LookupRegister(bytecode_iterator().GetRegisterOperand(0));
   Node* home_object = environment()->LookupAccumulator();
-  NameRef name(broker(), GetConstantForIndexOperand(1));
+  NameRef name = MakeRefForConstantForIndexOperand<Name>(1);
 
   FeedbackSource feedback =
       CreateFeedbackSource(bytecode_iterator().GetIndexOperand(2));
@@ -2168,7 +2173,7 @@ void BytecodeGraphBuilder::BuildNamedStore(StoreMode store_mode) {
   Node* value = environment()->LookupAccumulator();
   Node* object =
       environment()->LookupRegister(bytecode_iterator().GetRegisterOperand(0));
-  NameRef name(broker(), GetConstantForIndexOperand(1));
+  NameRef name = MakeRefForConstantForIndexOperand<Name>(1);
   FeedbackSource feedback =
       CreateFeedbackSource(bytecode_iterator().GetIndexOperand(2));
 
@@ -2209,7 +2214,7 @@ void BytecodeGraphBuilder::VisitStaNamedPropertyNoFeedback() {
   Node* value = environment()->LookupAccumulator();
   Node* object =
       environment()->LookupRegister(bytecode_iterator().GetRegisterOperand(0));
-  NameRef name(broker(), GetConstantForIndexOperand(1));
+  NameRef name = MakeRefForConstantForIndexOperand<Name>(1);
   LanguageMode language_mode =
       static_cast<LanguageMode>(bytecode_iterator().GetFlagOperand(2));
   const Operator* op =
@@ -2288,7 +2293,8 @@ void BytecodeGraphBuilder::VisitPopContext() {
 }
 
 void BytecodeGraphBuilder::VisitCreateClosure() {
-  SharedFunctionInfoRef shared_info(broker(), GetConstantForIndexOperand(0));
+  SharedFunctionInfoRef shared_info =
+      MakeRefForConstantForIndexOperand<SharedFunctionInfo>(0);
   AllocationType allocation =
       interpreter::CreateClosureFlags::PretenuredBit::decode(
           bytecode_iterator().GetFlagOperand(2))
@@ -2305,14 +2311,14 @@ void BytecodeGraphBuilder::VisitCreateClosure() {
 }
 
 void BytecodeGraphBuilder::VisitCreateBlockContext() {
-  ScopeInfoRef scope_info(broker(), GetConstantForIndexOperand(0));
+  ScopeInfoRef scope_info = MakeRefForConstantForIndexOperand<ScopeInfo>(0);
   const Operator* op = javascript()->CreateBlockContext(scope_info.object());
   Node* context = NewNode(op);
   environment()->BindAccumulator(context);
 }
 
 void BytecodeGraphBuilder::VisitCreateFunctionContext() {
-  ScopeInfoRef scope_info(broker(), GetConstantForIndexOperand(0));
+  ScopeInfoRef scope_info = MakeRefForConstantForIndexOperand<ScopeInfo>(0);
   uint32_t slots = bytecode_iterator().GetUnsignedImmediateOperand(1);
   const Operator* op = javascript()->CreateFunctionContext(
       scope_info.object(), slots, FUNCTION_SCOPE);
@@ -2321,7 +2327,7 @@ void BytecodeGraphBuilder::VisitCreateFunctionContext() {
 }
 
 void BytecodeGraphBuilder::VisitCreateEvalContext() {
-  ScopeInfoRef scope_info(broker(), GetConstantForIndexOperand(0));
+  ScopeInfoRef scope_info = MakeRefForConstantForIndexOperand<ScopeInfo>(0);
   uint32_t slots = bytecode_iterator().GetUnsignedImmediateOperand(1);
   const Operator* op = javascript()->CreateFunctionContext(scope_info.object(),
                                                            slots, EVAL_SCOPE);
@@ -2332,7 +2338,7 @@ void BytecodeGraphBuilder::VisitCreateEvalContext() {
 void BytecodeGraphBuilder::VisitCreateCatchContext() {
   interpreter::Register reg = bytecode_iterator().GetRegisterOperand(0);
   Node* exception = environment()->LookupRegister(reg);
-  ScopeInfoRef scope_info(broker(), GetConstantForIndexOperand(1));
+  ScopeInfoRef scope_info = MakeRefForConstantForIndexOperand<ScopeInfo>(1);
 
   const Operator* op = javascript()->CreateCatchContext(scope_info.object());
   Node* context = NewNode(op, exception);
@@ -2342,7 +2348,7 @@ void BytecodeGraphBuilder::VisitCreateCatchContext() {
 void BytecodeGraphBuilder::VisitCreateWithContext() {
   Node* object =
       environment()->LookupRegister(bytecode_iterator().GetRegisterOperand(0));
-  ScopeInfoRef scope_info(broker(), GetConstantForIndexOperand(1));
+  ScopeInfoRef scope_info = MakeRefForConstantForIndexOperand<ScopeInfo>(1);
 
   const Operator* op = javascript()->CreateWithContext(scope_info.object());
   Node* context = NewNode(op, object);
@@ -2368,7 +2374,7 @@ void BytecodeGraphBuilder::VisitCreateRestParameter() {
 }
 
 void BytecodeGraphBuilder::VisitCreateRegExpLiteral() {
-  StringRef constant_pattern(broker(), GetConstantForIndexOperand(0));
+  StringRef constant_pattern = MakeRefForConstantForIndexOperand<String>(0);
   int const slot_id = bytecode_iterator().GetIndexOperand(1);
   FeedbackSource pair = CreateFeedbackSource(slot_id);
   int literal_flags = bytecode_iterator().GetFlagOperand(2);
@@ -2381,8 +2387,8 @@ void BytecodeGraphBuilder::VisitCreateRegExpLiteral() {
 }
 
 void BytecodeGraphBuilder::VisitCreateArrayLiteral() {
-  ArrayBoilerplateDescriptionRef array_boilerplate_description(
-      broker(), GetConstantForIndexOperand(0));
+  ArrayBoilerplateDescriptionRef array_boilerplate_description =
+      MakeRefForConstantForIndexOperand<ArrayBoilerplateDescription>(0);
   int const slot_id = bytecode_iterator().GetIndexOperand(1);
   FeedbackSource pair = CreateFeedbackSource(slot_id);
   int bytecode_flags = bytecode_iterator().GetFlagOperand(2);
@@ -2420,8 +2426,8 @@ void BytecodeGraphBuilder::VisitCreateArrayFromIterable() {
 }
 
 void BytecodeGraphBuilder::VisitCreateObjectLiteral() {
-  ObjectBoilerplateDescriptionRef constant_properties(
-      broker(), GetConstantForIndexOperand(0));
+  ObjectBoilerplateDescriptionRef constant_properties =
+      MakeRefForConstantForIndexOperand<ObjectBoilerplateDescription>(0);
   int const slot_id = bytecode_iterator().GetIndexOperand(1);
   FeedbackSource pair = CreateFeedbackSource(slot_id);
   int bytecode_flags = bytecode_iterator().GetFlagOperand(2);
@@ -2459,8 +2465,8 @@ void BytecodeGraphBuilder::VisitCloneObject() {
 void BytecodeGraphBuilder::VisitGetTemplateObject() {
   FeedbackSource source =
       CreateFeedbackSource(bytecode_iterator().GetIndexOperand(1));
-  TemplateObjectDescriptionRef description(broker(),
-                                           GetConstantForIndexOperand(0));
+  TemplateObjectDescriptionRef description =
+      MakeRefForConstantForIndexOperand<TemplateObjectDescription>(0);
   STATIC_ASSERT(JSGetTemplateObjectNode::FeedbackVectorIndex() == 0);
   const Operator* op = javascript()->GetTemplateObject(
       description.object(), shared_info().object(), source);
@@ -2508,9 +2514,11 @@ void BytecodeGraphBuilder::BuildCall(ConvertReceiverMode receiver_mode,
   FeedbackSource feedback = CreateFeedbackSource(slot_id);
   CallFrequency frequency = ComputeCallFrequency(slot_id);
   SpeculationMode speculation_mode = GetSpeculationMode(slot_id);
+  CallFeedbackRelation call_feedback_relation =
+      ComputeCallFeedbackRelation(slot_id);
   const Operator* op =
       javascript()->Call(arg_count, frequency, feedback, receiver_mode,
-                         speculation_mode, CallFeedbackRelation::kRelated);
+                         speculation_mode, call_feedback_relation);
   DCHECK(IrOpcode::IsFeedbackCollectingOpcode(op->opcode()));
 
   JSTypeHintLowering::LoweringResult lowering = TryBuildSimplifiedCall(
@@ -2955,8 +2963,7 @@ void BytecodeGraphBuilder::VisitThrowReferenceErrorIfHole() {
   Node* accumulator = environment()->LookupAccumulator();
   Node* check_for_hole = NewNode(simplified()->ReferenceEqual(), accumulator,
                                  jsgraph()->TheHoleConstant());
-  Node* name =
-      jsgraph()->Constant(ObjectRef(broker(), GetConstantForIndexOperand(0)));
+  Node* name = jsgraph()->Constant(MakeRefForConstantForIndexOperand(0));
   BuildHoleCheckAndThrow(check_for_hole,
                          Runtime::kThrowAccessedUninitializedVariable, name);
 }
@@ -3088,6 +3095,19 @@ SpeculationMode BytecodeGraphBuilder::GetSpeculationMode(int slot_id) const {
                                    : feedback.AsCall().speculation_mode();
 }
 
+CallFeedbackRelation BytecodeGraphBuilder::ComputeCallFeedbackRelation(
+    int slot_id) const {
+  FeedbackSlot slot = FeedbackVector::ToSlot(slot_id);
+  FeedbackSource source(feedback_vector(), slot);
+  ProcessedFeedback const& feedback = broker()->GetFeedbackForCall(source);
+  if (feedback.IsInsufficient()) return CallFeedbackRelation::kUnrelated;
+  CallFeedbackContent call_feedback_content =
+      feedback.AsCall().call_feedback_content();
+  return call_feedback_content == CallFeedbackContent::kTarget
+             ? CallFeedbackRelation::kTarget
+             : CallFeedbackRelation::kReceiver;
+}
+
 void BytecodeGraphBuilder::VisitBitwiseNot() {
   FeedbackSource feedback = CreateFeedbackSource(
       bytecode_iterator().GetSlotOperand(kUnaryOperationHintIndex));
diff --git a/chromium/v8/src/compiler/code-assembler.cc b/chromium/v8/src/compiler/code-assembler.cc
index 4ec0c8f9d85..8ff1777366d 100644
--- a/chromium/v8/src/compiler/code-assembler.cc
+++ b/chromium/v8/src/compiler/code-assembler.cc
@@ -8,7 +8,7 @@
 
 #include "src/base/bits.h"
 #include "src/codegen/code-factory.h"
-#include "src/codegen/interface-descriptors.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/machine-type.h"
 #include "src/codegen/macro-assembler.h"
 #include "src/compiler/backend/instruction-selector.h"
@@ -331,6 +331,10 @@ TNode<Float64T> CodeAssembler::Float64Constant(double value) {
   return UncheckedCast<Float64T>(jsgraph()->Float64Constant(value));
 }
 
+bool CodeAssembler::IsMapOffsetConstant(Node* node) {
+  return raw_assembler()->IsMapOffsetConstant(node);
+}
+
 bool CodeAssembler::TryToInt32Constant(TNode<IntegralT> node,
                                        int32_t* out_value) {
   {
@@ -689,11 +693,15 @@ TNode<Object> CodeAssembler::LoadFullTagged(Node* base,
 
 TNode<Object> CodeAssembler::LoadFullTagged(Node* base, TNode<IntPtrT> offset,
                                             LoadSensitivity needs_poisoning) {
+  // Please use LoadFromObject(MachineType::MapInHeader(), object,
+  // IntPtrConstant(-kHeapObjectTag)) instead.
+  DCHECK(!raw_assembler()->IsMapOffsetConstantMinusTag(offset));
   return BitcastWordToTagged(Load<RawPtrT>(base, offset, needs_poisoning));
 }
 
 Node* CodeAssembler::AtomicLoad(MachineType type, TNode<RawPtrT> base,
                                 TNode<WordT> offset) {
+  DCHECK(!raw_assembler()->IsMapOffsetConstantMinusTag(offset));
   return raw_assembler()->AtomicLoad(type, base, offset);
 }
 
@@ -713,6 +721,27 @@ Node* CodeAssembler::LoadFromObject(MachineType type, TNode<Object> object,
   return raw_assembler()->LoadFromObject(type, object, offset);
 }
 
+#ifdef V8_MAP_PACKING
+Node* CodeAssembler::PackMapWord(Node* value) {
+  TNode<IntPtrT> map_word =
+      BitcastTaggedToWordForTagAndSmiBits(UncheckedCast<AnyTaggedT>(value));
+  TNode<WordT> packed = WordXor(UncheckedCast<WordT>(map_word),
+                                IntPtrConstant(Internals::kMapWordXorMask));
+  return BitcastWordToTaggedSigned(packed);
+}
+#endif
+
+TNode<AnyTaggedT> CodeAssembler::LoadRootMapWord(RootIndex root_index) {
+#ifdef V8_MAP_PACKING
+  Handle<Object> root = isolate()->root_handle(root_index);
+  Node* map = HeapConstant(Handle<Map>::cast(root));
+  map = PackMapWord(map);
+  return ReinterpretCast<AnyTaggedT>(map);
+#else
+  return LoadRoot(root_index);
+#endif
+}
+
 TNode<Object> CodeAssembler::LoadRoot(RootIndex root_index) {
   if (RootsTable::IsImmortalImmovable(root_index)) {
     Handle<Object> root = isolate()->root_handle(root_index);
@@ -794,11 +823,14 @@ void CodeAssembler::OptimizedStoreMap(TNode<HeapObject> object,
 }
 
 void CodeAssembler::Store(Node* base, Node* offset, Node* value) {
+  // Please use OptimizedStoreMap(base, value) instead.
+  DCHECK(!raw_assembler()->IsMapOffsetConstantMinusTag(offset));
   raw_assembler()->Store(MachineRepresentation::kTagged, base, offset, value,
                          kFullWriteBarrier);
 }
 
 void CodeAssembler::StoreEphemeronKey(Node* base, Node* offset, Node* value) {
+  DCHECK(!raw_assembler()->IsMapOffsetConstantMinusTag(offset));
   raw_assembler()->Store(MachineRepresentation::kTagged, base, offset, value,
                          kEphemeronKeyWriteBarrier);
 }
@@ -812,6 +844,8 @@ void CodeAssembler::StoreNoWriteBarrier(MachineRepresentation rep, Node* base,
 
 void CodeAssembler::StoreNoWriteBarrier(MachineRepresentation rep, Node* base,
                                         Node* offset, Node* value) {
+  // Please use OptimizedStoreMap(base, value) instead.
+  DCHECK(!raw_assembler()->IsMapOffsetConstantMinusTag(offset));
   raw_assembler()->Store(
       rep, base, offset, value,
       CanBeTaggedPointer(rep) ? kAssertNoWriteBarrier : kNoWriteBarrier);
@@ -825,6 +859,8 @@ void CodeAssembler::UnsafeStoreNoWriteBarrier(MachineRepresentation rep,
 void CodeAssembler::UnsafeStoreNoWriteBarrier(MachineRepresentation rep,
                                               Node* base, Node* offset,
                                               Node* value) {
+  // Please use OptimizedStoreMap(base, value) instead.
+  DCHECK(!raw_assembler()->IsMapOffsetConstantMinusTag(offset));
   raw_assembler()->Store(rep, base, offset, value, kNoWriteBarrier);
 }
 
@@ -837,12 +873,15 @@ void CodeAssembler::StoreFullTaggedNoWriteBarrier(TNode<RawPtrT> base,
 void CodeAssembler::StoreFullTaggedNoWriteBarrier(TNode<RawPtrT> base,
                                                   TNode<IntPtrT> offset,
                                                   TNode<Object> tagged_value) {
+  // Please use OptimizedStoreMap(base, tagged_value) instead.
+  DCHECK(!raw_assembler()->IsMapOffsetConstantMinusTag(offset));
   StoreNoWriteBarrier(MachineType::PointerRepresentation(), base, offset,
                       BitcastTaggedToWord(tagged_value));
 }
 
 void CodeAssembler::AtomicStore(MachineRepresentation rep, TNode<RawPtrT> base,
                                 TNode<WordT> offset, TNode<Word32T> value) {
+  DCHECK(!raw_assembler()->IsMapOffsetConstantMinusTag(offset));
   raw_assembler()->AtomicStore(rep, base, offset, value);
 }
 
diff --git a/chromium/v8/src/compiler/code-assembler.h b/chromium/v8/src/compiler/code-assembler.h
index 9163295cd62..75cb1a95838 100644
--- a/chromium/v8/src/compiler/code-assembler.h
+++ b/chromium/v8/src/compiler/code-assembler.h
@@ -310,7 +310,6 @@ class CodeAssemblerParameterizedLabel;
   V(Word64And, Word64T, Word64T, Word64T)                               \
   V(Word64Or, Word64T, Word64T, Word64T)                                \
   V(Word64Xor, Word64T, Word64T, Word64T)                               \
-  V(Word64Ror, Word64T, Word64T, Word64T)                               \
   V(Word64Shl, Word64T, Word64T, Word64T)                               \
   V(Word64Shr, Word64T, Word64T, Word64T)                               \
   V(Word64Sar, Word64T, Word64T, Word64T)
@@ -585,6 +584,8 @@ class V8_EXPORT_PRIVATE CodeAssembler {
     return value ? Int32TrueConstant() : Int32FalseConstant();
   }
 
+  bool IsMapOffsetConstant(Node* node);
+
   bool TryToInt32Constant(TNode<IntegralT> node, int32_t* out_value);
   bool TryToInt64Constant(TNode<IntegralT> node, int64_t* out_value);
   bool TryToIntPtrConstant(TNode<IntegralT> node, intptr_t* out_value);
@@ -789,8 +790,16 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   Node* LoadFromObject(MachineType type, TNode<Object> object,
                        TNode<IntPtrT> offset);
 
+#ifdef V8_MAP_PACKING
+  Node* PackMapWord(Node* value);
+#endif
+
   // Load a value from the root array.
+  // If map packing is enabled, LoadRoot for a root map returns the unpacked map
+  // word (i.e., the map). Use LoadRootMapWord to obtain the packed map word
+  // instead.
   TNode<Object> LoadRoot(RootIndex root_index);
+  TNode<AnyTaggedT> LoadRootMapWord(RootIndex root_index);
 
   template <typename Type>
   TNode<Type> UnalignedLoad(TNode<RawPtrT> base, TNode<IntPtrT> offset) {
@@ -978,6 +987,11 @@ class V8_EXPORT_PRIVATE CodeAssembler {
                               static_cast<TNode<Word32T>>(right)));
   }
 
+  TNode<IntPtrT> WordOr(TNode<IntPtrT> left, TNode<IntPtrT> right) {
+    return Signed(WordOr(static_cast<TNode<WordT>>(left),
+                         static_cast<TNode<WordT>>(right)));
+  }
+
   TNode<Int32T> Word32Or(TNode<Int32T> left, TNode<Int32T> right) {
     return Signed(Word32Or(static_cast<TNode<Word32T>>(left),
                            static_cast<TNode<Word32T>>(right)));
@@ -995,6 +1009,9 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   TNode<BoolT> Word64Equal(TNode<Word64T> left, TNode<Word64T> right);
   TNode<BoolT> Word64NotEqual(TNode<Word64T> left, TNode<Word64T> right);
 
+  TNode<IntPtrT> WordNot(TNode<IntPtrT> a) {
+    return Signed(WordNot(static_cast<TNode<WordT>>(a)));
+  }
   TNode<BoolT> Word32Or(TNode<BoolT> left, TNode<BoolT> right) {
     return UncheckedCast<BoolT>(Word32Or(static_cast<TNode<Word32T>>(left),
                                          static_cast<TNode<Word32T>>(right)));
diff --git a/chromium/v8/src/compiler/common-operator-reducer.cc b/chromium/v8/src/compiler/common-operator-reducer.cc
index 874bdb0d323..f002f34a40d 100644
--- a/chromium/v8/src/compiler/common-operator-reducer.cc
+++ b/chromium/v8/src/compiler/common-operator-reducer.cc
@@ -8,10 +8,11 @@
 
 #include "src/compiler/common-operator.h"
 #include "src/compiler/graph.h"
+#include "src/compiler/js-heap-broker.h"
 #include "src/compiler/machine-operator.h"
-#include "src/compiler/node.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
+#include "src/compiler/node.h"
 
 namespace v8 {
 namespace internal {
@@ -28,7 +29,9 @@ Decision DecideCondition(JSHeapBroker* broker, Node* const cond) {
     }
     case IrOpcode::kHeapConstant: {
       HeapObjectMatcher m(unwrapped);
-      return m.Ref(broker).BooleanValue() ? Decision::kTrue : Decision::kFalse;
+      base::Optional<bool> maybe_result = m.Ref(broker).TryGetBooleanValue();
+      if (!maybe_result.has_value()) return Decision::kUnknown;
+      return *maybe_result ? Decision::kTrue : Decision::kFalse;
     }
     default:
       return Decision::kUnknown;
@@ -53,7 +56,8 @@ CommonOperatorReducer::CommonOperatorReducer(Editor* editor, Graph* graph,
 }
 
 Reduction CommonOperatorReducer::Reduce(Node* node) {
-  DisallowHeapAccessIf no_heap_access(!FLAG_turbo_direct_heap_access);
+  DisallowHeapAccessIf no_heap_access(broker() == nullptr ||
+                                      !broker()->is_concurrent_inlining());
   switch (node->opcode()) {
     case IrOpcode::kBranch:
       return ReduceBranch(node);
diff --git a/chromium/v8/src/compiler/common-operator.h b/chromium/v8/src/compiler/common-operator.h
index 77483b14e86..4115414908d 100644
--- a/chromium/v8/src/compiler/common-operator.h
+++ b/chromium/v8/src/compiler/common-operator.h
@@ -617,8 +617,8 @@ class FrameState : public CommonNodeWrapperBase {
     // test, among others). Also, outer_frame_state points at the start node
     // for non-inlined functions. This could be avoided by checking
     // has_outer_frame_state() before casting to FrameState.
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kFrameState ||
-                     node->opcode() == IrOpcode::kStart);
+    DCHECK(node->opcode() == IrOpcode::kFrameState ||
+           node->opcode() == IrOpcode::kStart);
   }
 
   FrameStateInfo frame_state_info() const {
@@ -668,7 +668,7 @@ class FrameState : public CommonNodeWrapperBase {
 class StartNode final : public CommonNodeWrapperBase {
  public:
   explicit constexpr StartNode(Node* node) : CommonNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kStart);
+    DCHECK_EQ(IrOpcode::kStart, node->opcode());
   }
 
   // The receiver is counted as part of formal parameters.
@@ -687,10 +687,10 @@ class StartNode final : public CommonNodeWrapperBase {
                   kExtraOutputCount);
     // Checking related linkage methods here since they rely on Start node
     // layout.
-    CONSTEXPR_DCHECK(Linkage::kJSCallClosureParamIndex == -1);
-    CONSTEXPR_DCHECK(Linkage::GetJSCallNewTargetParamIndex(argc) == argc + 0);
-    CONSTEXPR_DCHECK(Linkage::GetJSCallArgCountParamIndex(argc) == argc + 1);
-    CONSTEXPR_DCHECK(Linkage::GetJSCallContextParamIndex(argc) == argc + 2);
+    DCHECK_EQ(-1, Linkage::kJSCallClosureParamIndex);
+    DCHECK_EQ(argc + 0, Linkage::GetJSCallNewTargetParamIndex(argc));
+    DCHECK_EQ(argc + 1, Linkage::GetJSCallArgCountParamIndex(argc));
+    DCHECK_EQ(argc + 2, Linkage::GetJSCallContextParamIndex(argc));
     return argc + kClosure + kNewTarget + kArgCount + kContext;
   }
 
@@ -773,8 +773,7 @@ class DynamicCheckMapsWithDeoptUnlessNode final : public CommonNodeWrapperBase {
  public:
   explicit constexpr DynamicCheckMapsWithDeoptUnlessNode(Node* node)
       : CommonNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() ==
-                     IrOpcode::kDynamicCheckMapsWithDeoptUnless);
+    DCHECK_EQ(IrOpcode::kDynamicCheckMapsWithDeoptUnless, node->opcode());
   }
 
 #define INPUTS(V)                   \
diff --git a/chromium/v8/src/compiler/compilation-dependencies.cc b/chromium/v8/src/compiler/compilation-dependencies.cc
index 3149fe490b9..8c73a759ff4 100644
--- a/chromium/v8/src/compiler/compilation-dependencies.cc
+++ b/chromium/v8/src/compiler/compilation-dependencies.cc
@@ -444,7 +444,7 @@ class ElementsKindDependency final : public CompilationDependency {
   bool IsValid() const override {
     Handle<AllocationSite> site = site_.object();
     ElementsKind kind = site->PointsToLiteral()
-                            ? site->boilerplate().GetElementsKind()
+                            ? site->boilerplate(kAcquireLoad).GetElementsKind()
                             : site->GetElementsKind();
     return kind_ == kind;
   }
@@ -580,38 +580,38 @@ bool CompilationDependencies::DependOnProtector(const PropertyCellRef& cell) {
 }
 
 bool CompilationDependencies::DependOnArrayBufferDetachingProtector() {
-  return DependOnProtector(PropertyCellRef(
+  return DependOnProtector(MakeRef(
       broker_,
       broker_->isolate()->factory()->array_buffer_detaching_protector()));
 }
 
 bool CompilationDependencies::DependOnArrayIteratorProtector() {
-  return DependOnProtector(PropertyCellRef(
+  return DependOnProtector(MakeRef(
       broker_, broker_->isolate()->factory()->array_iterator_protector()));
 }
 
 bool CompilationDependencies::DependOnArraySpeciesProtector() {
-  return DependOnProtector(PropertyCellRef(
+  return DependOnProtector(MakeRef(
       broker_, broker_->isolate()->factory()->array_species_protector()));
 }
 
 bool CompilationDependencies::DependOnNoElementsProtector() {
-  return DependOnProtector(PropertyCellRef(
-      broker_, broker_->isolate()->factory()->no_elements_protector()));
+  return DependOnProtector(
+      MakeRef(broker_, broker_->isolate()->factory()->no_elements_protector()));
 }
 
 bool CompilationDependencies::DependOnPromiseHookProtector() {
-  return DependOnProtector(PropertyCellRef(
+  return DependOnProtector(MakeRef(
       broker_, broker_->isolate()->factory()->promise_hook_protector()));
 }
 
 bool CompilationDependencies::DependOnPromiseSpeciesProtector() {
-  return DependOnProtector(PropertyCellRef(
+  return DependOnProtector(MakeRef(
       broker_, broker_->isolate()->factory()->promise_species_protector()));
 }
 
 bool CompilationDependencies::DependOnPromiseThenProtector() {
-  return DependOnProtector(PropertyCellRef(
+  return DependOnProtector(MakeRef(
       broker_, broker_->isolate()->factory()->promise_then_protector()));
 }
 
@@ -680,7 +680,7 @@ namespace {
 void DependOnStablePrototypeChain(CompilationDependencies* deps, MapRef map,
                                   base::Optional<JSObjectRef> last_prototype) {
   while (true) {
-    HeapObjectRef proto = map.prototype();
+    HeapObjectRef proto = map.prototype().value();
     if (!proto.IsJSObject()) {
       CHECK_EQ(proto.map().oddball_type(), OddballType::kNull);
       break;
@@ -697,7 +697,7 @@ void CompilationDependencies::DependOnStablePrototypeChains(
     MapContainer const& receiver_maps, WhereToStart start,
     base::Optional<JSObjectRef> last_prototype) {
   for (auto map : receiver_maps) {
-    MapRef receiver_map(broker_, map);
+    MapRef receiver_map = MakeRef(broker_, map);
     if (start == kStartAtReceiver) DependOnStableMap(receiver_map);
     if (receiver_map.IsPrimitiveMap()) {
       // Perform the implicit ToObject for primitives here.
diff --git a/chromium/v8/src/compiler/compilation-dependencies.h b/chromium/v8/src/compiler/compilation-dependencies.h
index 5cf2a3f94c4..d2acc352619 100644
--- a/chromium/v8/src/compiler/compilation-dependencies.h
+++ b/chromium/v8/src/compiler/compilation-dependencies.h
@@ -34,6 +34,10 @@ class V8_EXPORT_PRIVATE CompilationDependencies : public ZoneObject {
 
   V8_WARN_UNUSED_RESULT bool Commit(Handle<Code> code);
 
+  // TODO(jgruber): Remove this method once GetPropertyAccessInfo no longer
+  // uses the two-phase approach between serialization and compilation.
+  void ClearForConcurrentGetPropertyAccessInfo() { dependencies_.clear(); }
+
   // Return the initial map of {function} and record the assumption that it
   // stays the initial map.
   MapRef DependOnInitialMap(const JSFunctionRef& function);
diff --git a/chromium/v8/src/compiler/constant-folding-reducer.cc b/chromium/v8/src/compiler/constant-folding-reducer.cc
index 1c672c700d5..3b187467db2 100644
--- a/chromium/v8/src/compiler/constant-folding-reducer.cc
+++ b/chromium/v8/src/compiler/constant-folding-reducer.cc
@@ -5,6 +5,7 @@
 #include "src/compiler/constant-folding-reducer.h"
 
 #include "src/compiler/js-graph.h"
+#include "src/compiler/js-heap-broker.h"
 #include "src/objects/objects-inl.h"
 
 namespace v8 {
@@ -63,7 +64,7 @@ ConstantFoldingReducer::ConstantFoldingReducer(Editor* editor, JSGraph* jsgraph,
 ConstantFoldingReducer::~ConstantFoldingReducer() = default;
 
 Reduction ConstantFoldingReducer::Reduce(Node* node) {
-  DisallowHeapAccessIf no_heap_access(!FLAG_turbo_direct_heap_access);
+  DisallowHeapAccessIf no_heap_access(!broker()->is_concurrent_inlining());
   if (!NodeProperties::IsConstant(node) && NodeProperties::IsTyped(node) &&
       node->op()->HasProperty(Operator::kEliminatable) &&
       node->opcode() != IrOpcode::kFinishRegion) {
diff --git a/chromium/v8/src/compiler/dead-code-elimination.cc b/chromium/v8/src/compiler/dead-code-elimination.cc
index 61552ba523c..9b5958c81a7 100644
--- a/chromium/v8/src/compiler/dead-code-elimination.cc
+++ b/chromium/v8/src/compiler/dead-code-elimination.cc
@@ -16,12 +16,14 @@ namespace compiler {
 
 DeadCodeElimination::DeadCodeElimination(Editor* editor, Graph* graph,
                                          CommonOperatorBuilder* common,
-                                         Zone* temp_zone)
+                                         Zone* temp_zone,
+                                         bool is_concurrent_inlining)
     : AdvancedReducer(editor),
       graph_(graph),
       common_(common),
       dead_(graph->NewNode(common->Dead())),
-      zone_(temp_zone) {
+      zone_(temp_zone),
+      is_concurrent_inlining_(is_concurrent_inlining) {
   NodeProperties::SetType(dead_, Type::None());
 }
 
@@ -46,7 +48,7 @@ Node* FindDeadInput(Node* node) {
 }  // namespace
 
 Reduction DeadCodeElimination::Reduce(Node* node) {
-  DisallowHeapAccessIf no_heap_access(!FLAG_turbo_direct_heap_access);
+  DisallowHeapAccessIf no_heap_access(!is_concurrent_inlining_);
   switch (node->opcode()) {
     case IrOpcode::kEnd:
       return ReduceEnd(node);
diff --git a/chromium/v8/src/compiler/dead-code-elimination.h b/chromium/v8/src/compiler/dead-code-elimination.h
index 7fb22838c7b..3e6914d5e1f 100644
--- a/chromium/v8/src/compiler/dead-code-elimination.h
+++ b/chromium/v8/src/compiler/dead-code-elimination.h
@@ -40,7 +40,8 @@ class V8_EXPORT_PRIVATE DeadCodeElimination final
     : public NON_EXPORTED_BASE(AdvancedReducer) {
  public:
   DeadCodeElimination(Editor* editor, Graph* graph,
-                      CommonOperatorBuilder* common, Zone* temp_zone);
+                      CommonOperatorBuilder* common, Zone* temp_zone,
+                      bool is_concurrent_inlining);
   ~DeadCodeElimination() final = default;
   DeadCodeElimination(const DeadCodeElimination&) = delete;
   DeadCodeElimination& operator=(const DeadCodeElimination&) = delete;
@@ -78,6 +79,8 @@ class V8_EXPORT_PRIVATE DeadCodeElimination final
   CommonOperatorBuilder* const common_;
   Node* const dead_;
   Zone* zone_;
+
+  const bool is_concurrent_inlining_;
 };
 
 }  // namespace compiler
diff --git a/chromium/v8/src/compiler/decompression-optimizer.cc b/chromium/v8/src/compiler/decompression-optimizer.cc
index 9b2362c9ef9..a8c29d51e4f 100644
--- a/chromium/v8/src/compiler/decompression-optimizer.cc
+++ b/chromium/v8/src/compiler/decompression-optimizer.cc
@@ -17,7 +17,8 @@ bool IsMachineLoad(Node* const node) {
   const IrOpcode::Value opcode = node->opcode();
   return opcode == IrOpcode::kLoad || opcode == IrOpcode::kPoisonedLoad ||
          opcode == IrOpcode::kProtectedLoad ||
-         opcode == IrOpcode::kUnalignedLoad;
+         opcode == IrOpcode::kUnalignedLoad ||
+         opcode == IrOpcode::kLoadImmutable;
 }
 
 bool IsTaggedMachineLoad(Node* const node) {
@@ -204,6 +205,10 @@ void DecompressionOptimizer::ChangeLoad(Node* const node) {
     case IrOpcode::kLoad:
       NodeProperties::ChangeOp(node, machine()->Load(compressed_load_rep));
       break;
+    case IrOpcode::kLoadImmutable:
+      NodeProperties::ChangeOp(node,
+                               machine()->LoadImmutable(compressed_load_rep));
+      break;
     case IrOpcode::kPoisonedLoad:
       NodeProperties::ChangeOp(node,
                                machine()->PoisonedLoad(compressed_load_rep));
diff --git a/chromium/v8/src/compiler/effect-control-linearizer.cc b/chromium/v8/src/compiler/effect-control-linearizer.cc
index dedf68e93c2..9799691ce63 100644
--- a/chromium/v8/src/compiler/effect-control-linearizer.cc
+++ b/chromium/v8/src/compiler/effect-control-linearizer.cc
@@ -7,6 +7,7 @@
 #include "include/v8-fast-api-calls.h"
 #include "src/base/bits.h"
 #include "src/codegen/code-factory.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/machine-type.h"
 #include "src/common/ptr-compr-inl.h"
 #include "src/compiler/access-builder.h"
@@ -16,11 +17,13 @@
 #include "src/compiler/js-graph.h"
 #include "src/compiler/js-heap-broker.h"
 #include "src/compiler/linkage.h"
+#include "src/compiler/memory-lowering.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-origin-table.h"
 #include "src/compiler/node-properties.h"
 #include "src/compiler/node.h"
 #include "src/compiler/schedule.h"
+#include "src/compiler/select-lowering.h"
 #include "src/execution/frames.h"
 #include "src/heap/factory-inl.h"
 #include "src/objects/heap-number.h"
@@ -31,10 +34,13 @@ namespace v8 {
 namespace internal {
 namespace compiler {
 
+enum class MaintainSchedule { kMaintain, kDiscard };
+enum class MaskArrayIndexEnable { kDoNotMaskArrayIndex, kMaskArrayIndex };
+
 class EffectControlLinearizer {
  public:
   EffectControlLinearizer(JSGraph* js_graph, Schedule* schedule,
-                          Zone* temp_zone,
+                          JSGraphAssembler* graph_assembler, Zone* temp_zone,
                           SourcePositionTable* source_positions,
                           NodeOriginTable* node_origins,
                           MaskArrayIndexEnable mask_array_index,
@@ -48,8 +54,7 @@ class EffectControlLinearizer {
         source_positions_(source_positions),
         node_origins_(node_origins),
         broker_(broker),
-        graph_assembler_(js_graph, temp_zone, base::nullopt,
-                         should_maintain_schedule() ? schedule : nullptr),
+        graph_assembler_(graph_assembler),
         frame_state_zapper_(nullptr) {}
 
   void Run();
@@ -112,7 +117,6 @@ class EffectControlLinearizer {
   Node* LowerCheckedTaggedToFloat64(Node* node, Node* frame_state);
   Node* LowerCheckedTaggedToTaggedSigned(Node* node, Node* frame_state);
   Node* LowerCheckedTaggedToTaggedPointer(Node* node, Node* frame_state);
-  Node* LowerBigIntAsUintN(Node* node, Node* frame_state);
   Node* LowerChangeUint64ToBigInt(Node* node);
   Node* LowerTruncateBigIntToUint64(Node* node);
   Node* LowerChangeTaggedToFloat64(Node* node);
@@ -192,6 +196,7 @@ class EffectControlLinearizer {
   void LowerTransitionElementsKind(Node* node);
   Node* LowerLoadFieldByIndex(Node* node);
   Node* LowerLoadMessage(Node* node);
+  Node* AdaptFastCallArgument(Node* node, CTypeInfo::Type arg_type);
   Node* LowerFastApiCall(Node* node);
   Node* LowerLoadTypedElement(Node* node);
   Node* LowerLoadDataViewElement(Node* node);
@@ -307,7 +312,7 @@ class EffectControlLinearizer {
     return js_graph_->simplified();
   }
   MachineOperatorBuilder* machine() const { return js_graph_->machine(); }
-  JSGraphAssembler* gasm() { return &graph_assembler_; }
+  JSGraphAssembler* gasm() const { return graph_assembler_; }
   JSHeapBroker* broker() const { return broker_; }
 
   JSGraph* js_graph_;
@@ -319,7 +324,7 @@ class EffectControlLinearizer {
   SourcePositionTable* source_positions_;
   NodeOriginTable* node_origins_;
   JSHeapBroker* broker_;
-  JSGraphAssembler graph_assembler_;
+  JSGraphAssembler* graph_assembler_;
   Node* frame_state_zapper_;  // For tracking down compiler::Node::New crashes.
 };
 
@@ -1059,9 +1064,6 @@ bool EffectControlLinearizer::TryWireInStateEffect(Node* node,
     case IrOpcode::kCheckedTaggedToTaggedPointer:
       result = LowerCheckedTaggedToTaggedPointer(node, frame_state);
       break;
-    case IrOpcode::kBigIntAsUintN:
-      result = LowerBigIntAsUintN(node, frame_state);
-      break;
     case IrOpcode::kChangeUint64ToBigInt:
       result = LowerChangeUint64ToBigInt(node);
       break;
@@ -2934,22 +2936,6 @@ Node* EffectControlLinearizer::LowerCheckBigInt(Node* node, Node* frame_state) {
   return value;
 }
 
-Node* EffectControlLinearizer::LowerBigIntAsUintN(Node* node,
-                                                  Node* frame_state) {
-  DCHECK(machine()->Is64());
-
-  const int bits = OpParameter<int>(node->op());
-  DCHECK(0 <= bits && bits <= 64);
-
-  if (bits == 64) {
-    // Reduce to nop.
-    return node->InputAt(0);
-  } else {
-    const uint64_t msk = (1ULL << bits) - 1ULL;
-    return __ Word64And(node->InputAt(0), __ Int64Constant(msk));
-  }
-}
-
 Node* EffectControlLinearizer::LowerChangeUint64ToBigInt(Node* node) {
   DCHECK(machine()->Is64());
 
@@ -3683,8 +3669,7 @@ Node* EffectControlLinearizer::LowerToBoolean(Node* node) {
   auto call_descriptor = Linkage::GetStubCallDescriptor(
       graph()->zone(), callable.descriptor(),
       callable.descriptor().GetStackParameterCount(), flags, properties);
-  return __ Call(call_descriptor, __ HeapConstant(callable.code()), obj,
-                 __ NoContextConstant());
+  return __ Call(call_descriptor, __ HeapConstant(callable.code()), obj);
 }
 
 Node* EffectControlLinearizer::LowerArgumentsLength(Node* node) {
@@ -4974,7 +4959,8 @@ void EffectControlLinearizer::LowerStoreMessage(Node* node) {
   __ StoreField(AccessBuilder::ForExternalIntPtr(), offset, object_pattern);
 }
 
-static MachineType MachineTypeFor(CTypeInfo::Type type) {
+namespace {
+MachineType MachineTypeFor(CTypeInfo::Type type) {
   switch (type) {
     case CTypeInfo::Type::kVoid:
       return MachineType::AnyTagged();
@@ -4993,9 +4979,34 @@ static MachineType MachineTypeFor(CTypeInfo::Type type) {
     case CTypeInfo::Type::kFloat64:
       return MachineType::Float64();
     case CTypeInfo::Type::kV8Value:
+    case CTypeInfo::Type::kApiObject:
       return MachineType::AnyTagged();
   }
 }
+}  // namespace
+
+Node* EffectControlLinearizer::AdaptFastCallArgument(Node* node,
+                                                     CTypeInfo::Type arg_type) {
+  switch (arg_type) {
+    case CTypeInfo::Type::kV8Value: {
+      int kAlign = alignof(uintptr_t);
+      int kSize = sizeof(uintptr_t);
+      Node* stack_slot = __ StackSlot(kSize, kAlign);
+
+      __ Store(StoreRepresentation(MachineType::PointerRepresentation(),
+                                   kNoWriteBarrier),
+               stack_slot, 0, node);
+
+      return stack_slot;
+    }
+    case CTypeInfo::Type::kFloat32: {
+      return __ TruncateFloat64ToFloat32(node);
+    }
+    default: {
+      return node;
+    }
+  }
+}
 
 Node* EffectControlLinearizer::LowerFastApiCall(Node* node) {
   FastApiCallNode n(node);
@@ -5060,13 +5071,9 @@ Node* EffectControlLinearizer::LowerFastApiCall(Node* node) {
   inputs[0] = n.target();
   for (int i = FastApiCallNode::kFastTargetInputCount;
        i < c_arg_count + FastApiCallNode::kFastTargetInputCount; ++i) {
-    if (c_signature->ArgumentInfo(i - 1).GetType() ==
-        CTypeInfo::Type::kFloat32) {
-      inputs[i] =
-          __ TruncateFloat64ToFloat32(NodeProperties::GetValueInput(node, i));
-    } else {
-      inputs[i] = NodeProperties::GetValueInput(node, i);
-    }
+    inputs[i] =
+        AdaptFastCallArgument(NodeProperties::GetValueInput(node, i),
+                              c_signature->ArgumentInfo(i - 1).GetType());
   }
   if (c_signature->HasOptions()) {
     inputs[c_arg_count + 1] = stack_slot;
@@ -5113,6 +5120,7 @@ Node* EffectControlLinearizer::LowerFastApiCall(Node* node) {
           c_call_result, CheckForMinusZeroMode::kCheckForMinusZero);
       break;
     case CTypeInfo::Type::kV8Value:
+    case CTypeInfo::Type::kApiObject:
       UNREACHABLE();
   }
 
@@ -5859,11 +5867,10 @@ Node* EffectControlLinearizer::CallBuiltin(Builtins::Name builtin,
 Node* EffectControlLinearizer::LowerAssertType(Node* node) {
   DCHECK_EQ(node->opcode(), IrOpcode::kAssertType);
   Type type = OpParameter<Type>(node->op());
-  DCHECK(type.IsRange());
-  auto range = type.AsRange();
+  CHECK(type.CanBeAsserted());
   Node* const input = node->InputAt(0);
-  Node* const min = __ NumberConstant(range->Min());
-  Node* const max = __ NumberConstant(range->Max());
+  Node* const min = __ NumberConstant(type.Min());
+  Node* const max = __ NumberConstant(type.Max());
   CallBuiltin(Builtins::kCheckNumberInRange, node->op()->properties(), input,
               min, max, __ SmiConstant(node->id()));
   return input;
@@ -6462,15 +6469,47 @@ Node* EffectControlLinearizer::BuildIsClearedWeakReference(Node* maybe_object) {
 
 #undef __
 
+namespace {
+
+MaskArrayIndexEnable MaskArrayForPoisonLevel(
+    PoisoningMitigationLevel poison_level) {
+  return (poison_level != PoisoningMitigationLevel::kDontPoison)
+             ? MaskArrayIndexEnable::kMaskArrayIndex
+             : MaskArrayIndexEnable::kDoNotMaskArrayIndex;
+}
+
+}  // namespace
+
 void LinearizeEffectControl(JSGraph* graph, Schedule* schedule, Zone* temp_zone,
                             SourcePositionTable* source_positions,
                             NodeOriginTable* node_origins,
-                            MaskArrayIndexEnable mask_array_index,
-                            MaintainSchedule maintain_schedule,
+                            PoisoningMitigationLevel poison_level,
+                            JSHeapBroker* broker) {
+  JSGraphAssembler graph_assembler_(graph, temp_zone, base::nullopt, nullptr);
+  EffectControlLinearizer linearizer(graph, schedule, &graph_assembler_,
+                                     temp_zone, source_positions, node_origins,
+                                     MaskArrayForPoisonLevel(poison_level),
+                                     MaintainSchedule::kDiscard, broker);
+  linearizer.Run();
+}
+
+void LowerToMachineSchedule(JSGraph* js_graph, Schedule* schedule,
+                            Zone* temp_zone,
+                            SourcePositionTable* source_positions,
+                            NodeOriginTable* node_origins,
+                            PoisoningMitigationLevel poison_level,
                             JSHeapBroker* broker) {
-  EffectControlLinearizer linearizer(
-      graph, schedule, temp_zone, source_positions, node_origins,
-      mask_array_index, maintain_schedule, broker);
+  JSGraphAssembler graph_assembler(js_graph, temp_zone, base::nullopt,
+                                   schedule);
+  EffectControlLinearizer linearizer(js_graph, schedule, &graph_assembler,
+                                     temp_zone, source_positions, node_origins,
+                                     MaskArrayForPoisonLevel(poison_level),
+                                     MaintainSchedule::kMaintain, broker);
+  MemoryLowering memory_lowering(js_graph, temp_zone, &graph_assembler,
+                                 poison_level);
+  SelectLowering select_lowering(&graph_assembler, js_graph->graph());
+  graph_assembler.AddInlineReducer(&memory_lowering);
+  graph_assembler.AddInlineReducer(&select_lowering);
   linearizer.Run();
 }
 
diff --git a/chromium/v8/src/compiler/effect-control-linearizer.h b/chromium/v8/src/compiler/effect-control-linearizer.h
index fbfd3046dce..fca4899263c 100644
--- a/chromium/v8/src/compiler/effect-control-linearizer.h
+++ b/chromium/v8/src/compiler/effect-control-linearizer.h
@@ -23,15 +23,18 @@ class Schedule;
 class SourcePositionTable;
 class JSHeapBroker;
 
-enum class MaskArrayIndexEnable { kDoNotMaskArrayIndex, kMaskArrayIndex };
-
-enum class MaintainSchedule { kMaintain, kDiscard };
-
 V8_EXPORT_PRIVATE void LinearizeEffectControl(
     JSGraph* graph, Schedule* schedule, Zone* temp_zone,
     SourcePositionTable* source_positions, NodeOriginTable* node_origins,
-    MaskArrayIndexEnable mask_array_index, MaintainSchedule maintain_schedule,
-    JSHeapBroker* broker);
+    PoisoningMitigationLevel poison_level, JSHeapBroker* broker);
+
+// Performs effect control linearization lowering in addition to machine
+// lowering, producing a scheduled graph that is ready for instruction
+// selection.
+V8_EXPORT_PRIVATE void LowerToMachineSchedule(
+    JSGraph* graph, Schedule* schedule, Zone* temp_zone,
+    SourcePositionTable* source_positions, NodeOriginTable* node_origins,
+    PoisoningMitigationLevel poison_level, JSHeapBroker* broker);
 
 }  // namespace compiler
 }  // namespace internal
diff --git a/chromium/v8/src/compiler/globals.h b/chromium/v8/src/compiler/globals.h
index ff5b5a57326..66b3272b433 100644
--- a/chromium/v8/src/compiler/globals.h
+++ b/chromium/v8/src/compiler/globals.h
@@ -49,17 +49,24 @@ inline size_t hash_value(StackCheckKind kind) {
   return static_cast<size_t>(kind);
 }
 
-// The CallFeedbackRelation states whether the target feedback stored with a
-// JSCall is related to the call. If, during lowering, a JSCall (e.g. of a
-// higher order function) is replaced by a JSCall with another target, the
-// feedback has to be kept but is now unrelated.
-enum class CallFeedbackRelation { kRelated, kUnrelated };
+// The CallFeedbackRelation provides the meaning of the call feedback for a
+// TurboFan JSCall operator
+// - kReceiver: The call target was Function.prototype.apply and its receiver
+//   was recorded as the feedback value.
+// - kTarget: The call target was recorded as the feedback value.
+// - kUnrelated: The feedback is no longer related to the call. If, during
+//   lowering, a JSCall (e.g. of a higher order function) is replaced by a
+//   JSCall with another target, the feedback has to be kept but is now
+//   unrelated.
+enum class CallFeedbackRelation { kReceiver, kTarget, kUnrelated };
 
 inline std::ostream& operator<<(std::ostream& os,
                                 CallFeedbackRelation call_feedback_relation) {
   switch (call_feedback_relation) {
-    case CallFeedbackRelation::kRelated:
-      return os << "CallFeedbackRelation::kRelated";
+    case CallFeedbackRelation::kReceiver:
+      return os << "CallFeedbackRelation::kReceiver";
+    case CallFeedbackRelation::kTarget:
+      return os << "CallFeedbackRelation::kTarget";
     case CallFeedbackRelation::kUnrelated:
       return os << "CallFeedbackRelation::kUnrelated";
   }
diff --git a/chromium/v8/src/compiler/graph-assembler.cc b/chromium/v8/src/compiler/graph-assembler.cc
index 897e22ac264..73938a5fb97 100644
--- a/chromium/v8/src/compiler/graph-assembler.cc
+++ b/chromium/v8/src/compiler/graph-assembler.cc
@@ -5,6 +5,8 @@
 #include "src/compiler/graph-assembler.h"
 
 #include "src/codegen/code-factory.h"
+#include "src/compiler/access-builder.h"
+#include "src/compiler/graph-reducer.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/schedule.h"
 // For TNode types.
@@ -329,6 +331,21 @@ BasicBlock* GraphAssembler::BasicBlockUpdater::Finalize(BasicBlock* original) {
   return block;
 }
 
+class V8_NODISCARD GraphAssembler::BlockInlineReduction {
+ public:
+  explicit BlockInlineReduction(GraphAssembler* gasm) : gasm_(gasm) {
+    DCHECK(!gasm_->inline_reductions_blocked_);
+    gasm_->inline_reductions_blocked_ = true;
+  }
+  ~BlockInlineReduction() {
+    DCHECK(gasm_->inline_reductions_blocked_);
+    gasm_->inline_reductions_blocked_ = false;
+  }
+
+ private:
+  GraphAssembler* gasm_;
+};
+
 GraphAssembler::GraphAssembler(
     MachineGraph* mcgraph, Zone* zone,
     base::Optional<NodeChangedCallback> node_changed_callback,
@@ -342,6 +359,8 @@ GraphAssembler::GraphAssembler(
                          ? new BasicBlockUpdater(schedule, mcgraph->graph(),
                                                  mcgraph->common(), zone)
                          : nullptr),
+      inline_reducers_(zone),
+      inline_reductions_blocked_(false),
       loop_headers_(zone),
       mark_loop_exits_(mark_loop_exits) {}
 
@@ -530,6 +549,31 @@ Node* JSGraphAssembler::StoreField(FieldAccess const& access, Node* object,
                                   value, effect(), control()));
 }
 
+#ifdef V8_MAP_PACKING
+TNode<Map> GraphAssembler::UnpackMapWord(Node* map_word) {
+  map_word = BitcastTaggedToWordForTagAndSmiBits(map_word);
+  // TODO(wenyuzhao): Clear header metadata.
+  Node* map = WordXor(map_word, IntPtrConstant(Internals::kMapWordXorMask));
+  return TNode<Map>::UncheckedCast(BitcastWordToTagged(map));
+}
+
+Node* GraphAssembler::PackMapWord(TNode<Map> map) {
+  Node* map_word = BitcastTaggedToWordForTagAndSmiBits(map);
+  Node* packed = WordXor(map_word, IntPtrConstant(Internals::kMapWordXorMask));
+  return BitcastWordToTaggedSigned(packed);
+}
+#endif
+
+TNode<Map> GraphAssembler::LoadMap(Node* object) {
+  Node* map_word = Load(MachineType::TaggedPointer(), object,
+                        HeapObject::kMapOffset - kHeapObjectTag);
+#ifdef V8_MAP_PACKING
+  return UnpackMapWord(map_word);
+#else
+  return TNode<Map>::UncheckedCast(map_word);
+#endif
+}
+
 Node* JSGraphAssembler::StoreElement(ElementAccess const& access, Node* object,
                                      Node* index, Node* value) {
   return AddNode(graph()->NewNode(simplified()->StoreElement(access), object,
@@ -968,6 +1012,28 @@ Node* GraphAssembler::AddClonedNode(Node* node) {
 }
 
 Node* GraphAssembler::AddNode(Node* node) {
+  if (!inline_reducers_.empty() && !inline_reductions_blocked_) {
+    // Reducers may add new nodes to the graph using this graph assembler,
+    // however they should never introduce nodes that need further reduction,
+    // so block reduction
+    BlockInlineReduction scope(this);
+    Reduction reduction;
+    for (auto reducer : inline_reducers_) {
+      reduction = reducer->Reduce(node, nullptr);
+      if (reduction.Changed()) break;
+    }
+    if (reduction.Changed()) {
+      Node* replacement = reduction.replacement();
+      if (replacement != node) {
+        // Replace all uses of node and kill the node to make sure we don't
+        // leave dangling dead uses.
+        NodeProperties::ReplaceUses(node, replacement, effect(), control());
+        node->Kill();
+        return replacement;
+      }
+    }
+  }
+
   if (block_updater_) {
     block_updater_->AddNode(node);
   }
diff --git a/chromium/v8/src/compiler/graph-assembler.h b/chromium/v8/src/compiler/graph-assembler.h
index bb3bc34a58c..d368f364074 100644
--- a/chromium/v8/src/compiler/graph-assembler.h
+++ b/chromium/v8/src/compiler/graph-assembler.h
@@ -27,6 +27,7 @@ namespace compiler {
 
 class Schedule;
 class BasicBlock;
+class Reducer;
 
 #define PURE_ASSEMBLER_MACH_UNOP_LIST(V) \
   V(BitcastFloat32ToInt32)               \
@@ -270,6 +271,12 @@ class V8_EXPORT_PRIVATE GraphAssembler {
   CHECKED_ASSEMBLER_MACH_BINOP_LIST(BINOP_DECL)
 #undef BINOP_DECL
 
+#ifdef V8_MAP_PACKING
+  Node* PackMapWord(TNode<Map> map);
+  TNode<Map> UnpackMapWord(Node* map_word);
+#endif
+  TNode<Map> LoadMap(Node* object);
+
   Node* DebugBreak();
 
   // Unreachable nodes are similar to Goto in that they reset effect/control to
@@ -436,6 +443,16 @@ class V8_EXPORT_PRIVATE GraphAssembler {
 
   void ConnectUnreachableToEnd();
 
+  // Add an inline reducers such that nodes added to the graph will be run
+  // through the reducers and possibly further lowered. Each reducer should
+  // operate on independent node types since once a reducer changes a node we
+  // no longer run any other reducers on that node. The reducers should also
+  // only generate new nodes that wouldn't be further reduced, as new nodes
+  // generated by a reducer won't be passed through the reducers again.
+  void AddInlineReducer(Reducer* reducer) {
+    inline_reducers_.push_back(reducer);
+  }
+
   Control control() const { return Control(control_); }
   Effect effect() const { return Effect(effect_); }
 
@@ -532,6 +549,8 @@ class V8_EXPORT_PRIVATE GraphAssembler {
   };
 
  private:
+  class BlockInlineReduction;
+
   template <typename... Vars>
   void BranchImpl(Node* condition,
                   GraphAssemblerLabel<sizeof...(Vars)>* if_true,
@@ -551,6 +570,11 @@ class V8_EXPORT_PRIVATE GraphAssembler {
   base::Optional<NodeChangedCallback> node_changed_callback_;
   std::unique_ptr<BasicBlockUpdater> block_updater_;
 
+  // Inline reducers enable reductions to be performed to nodes as they are
+  // added to the graph with the graph assembler.
+  ZoneVector<Reducer*> inline_reducers_;
+  bool inline_reductions_blocked_;
+
   // Track loop information in order to properly mark loop exits with
   // {LoopExit,LoopExitEffect,LoopExitValue} nodes. The outermost level has
   // a nesting level of 0. See also GraphAssembler::LoopScope.
diff --git a/chromium/v8/src/compiler/graph-reducer.cc b/chromium/v8/src/compiler/graph-reducer.cc
index 998f37eea80..643f6622623 100644
--- a/chromium/v8/src/compiler/graph-reducer.cc
+++ b/chromium/v8/src/compiler/graph-reducer.cc
@@ -112,7 +112,7 @@ Reduction GraphReducer::Reduce(Node* const node) {
         if (FLAG_trace_turbo_reduction) {
           UnparkedScopeIfNeeded unparked(broker_);
           // TODO(neis): Disallow racy handle dereference once we stop
-          // supporting --no-local-heaps --no-turbo-direct-heap-access.
+          // supporting --no-local-heaps --no-concurrent-inlining.
           AllowHandleDereference allow_deref;
           StdoutStream{} << "- In-place update of #" << *node << " by reducer "
                          << (*i)->reducer_name() << std::endl;
@@ -125,7 +125,7 @@ Reduction GraphReducer::Reduce(Node* const node) {
         if (FLAG_trace_turbo_reduction) {
           UnparkedScopeIfNeeded unparked(broker_);
           // TODO(neis): Disallow racy handle dereference once we stop
-          // supporting --no-local-heaps --no-turbo-direct-heap-access.
+          // supporting --no-local-heaps --no-concurrent-inlining.
           AllowHandleDereference allow_deref;
           StdoutStream{} << "- Replacement of #" << *node << " with #"
                          << *(reduction.replacement()) << " by reducer "
diff --git a/chromium/v8/src/compiler/graph-visualizer.cc b/chromium/v8/src/compiler/graph-visualizer.cc
index eb3e4168f9a..cc1d07085fe 100644
--- a/chromium/v8/src/compiler/graph-visualizer.cc
+++ b/chromium/v8/src/compiler/graph-visualizer.cc
@@ -421,7 +421,7 @@ std::ostream& operator<<(std::ostream& os, const GraphAsJSON& ad) {
 
 class GraphC1Visualizer {
  public:
-  GraphC1Visualizer(std::ostream& os, Zone* zone);  // NOLINT
+  GraphC1Visualizer(std::ostream& os, Zone* zone);
   GraphC1Visualizer(const GraphC1Visualizer&) = delete;
   GraphC1Visualizer& operator=(const GraphC1Visualizer&) = delete;
 
@@ -1132,8 +1132,9 @@ std::ostream& operator<<(std::ostream& os, const InstructionOperandAsJSON& o) {
           os << ",\"tooltip\": \"MUST_HAVE_SLOT\"";
           break;
         }
-        case UnallocatedOperand::SAME_AS_FIRST_INPUT: {
-          os << ",\"tooltip\": \"SAME_AS_FIRST_INPUT\"";
+        case UnallocatedOperand::SAME_AS_INPUT: {
+          os << ",\"tooltip\": \"SAME_AS_INPUT: " << unalloc->input_index()
+             << "\"";
           break;
         }
         case UnallocatedOperand::REGISTER_OR_SLOT: {
diff --git a/chromium/v8/src/compiler/graph-visualizer.h b/chromium/v8/src/compiler/graph-visualizer.h
index 55859330157..39a2ef50210 100644
--- a/chromium/v8/src/compiler/graph-visualizer.h
+++ b/chromium/v8/src/compiler/graph-visualizer.h
@@ -6,7 +6,8 @@
 #define V8_COMPILER_GRAPH_VISUALIZER_H_
 
 #include <stdio.h>
-#include <fstream>  // NOLINT(readability/streams)
+
+#include <fstream>
 #include <iosfwd>
 #include <memory>
 
diff --git a/chromium/v8/src/compiler/graph.h b/chromium/v8/src/compiler/graph.h
index eb6bfd7e77a..25682dc9aeb 100644
--- a/chromium/v8/src/compiler/graph.h
+++ b/chromium/v8/src/compiler/graph.h
@@ -67,7 +67,7 @@ class V8_EXPORT_PRIVATE Graph final : public NON_EXPORTED_BASE(ZoneObject) {
 
   // Factory template for nodes with static input counts.
   // Note: Template magic below is used to ensure this method is only considered
-  // for argument types convertible to Node* during overload resoluation.
+  // for argument types convertible to Node* during overload resolution.
   template <typename... Nodes,
             typename = typename std::enable_if_t<
                 base::all(std::is_convertible<Nodes, Node*>::value...)>>
diff --git a/chromium/v8/src/compiler/heap-refs.cc b/chromium/v8/src/compiler/heap-refs.cc
new file mode 100644
index 00000000000..7931407a7ec
--- /dev/null
+++ b/chromium/v8/src/compiler/heap-refs.cc
@@ -0,0 +1,4594 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/compiler/heap-refs.h"
+
+#ifdef ENABLE_SLOW_DCHECKS
+#include <algorithm>
+#endif
+
+#include "src/api/api-inl.h"
+#include "src/ast/modules.h"
+#include "src/codegen/code-factory.h"
+#include "src/compiler/graph-reducer.h"
+#include "src/compiler/js-heap-broker.h"
+#include "src/execution/protectors-inl.h"
+#include "src/objects/descriptor-array.h"
+#include "src/objects/heap-number-inl.h"
+#include "src/objects/js-array-buffer-inl.h"
+#include "src/objects/property-cell.h"
+#include "src/objects/template-objects-inl.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+#define TRACE(broker, x) TRACE_BROKER(broker, x)
+#define TRACE_MISSING(broker, x) TRACE_BROKER_MISSING(broker, x)
+
+#define FORWARD_DECL(Name, ...) class Name##Data;
+HEAP_BROKER_OBJECT_LIST(FORWARD_DECL)
+#undef FORWARD_DECL
+
+// There are several kinds of ObjectData values.
+//
+// kSmi: The underlying V8 object is a Smi and the data is an instance of the
+//   base class (ObjectData), i.e. it's basically just the handle.  Because the
+//   object is a Smi, it's safe to access the handle in order to extract the
+//   number value, and AsSmi() does exactly that.
+//
+// kSerializedHeapObject: The underlying V8 object is a HeapObject and the
+//   data is an instance of the corresponding (most-specific) subclass, e.g.
+//   JSFunctionData, which provides serialized information about the object.
+//
+// kBackgroundSerializedHeapObject: Like kSerializedHeapObject, but
+//   allows serialization from the background thread.
+//
+// kUnserializedHeapObject: The underlying V8 object is a HeapObject and the
+//   data is an instance of the base class (ObjectData), i.e. it basically
+//   carries no information other than the handle.
+//
+// kNeverSerializedHeapObject: The underlying V8 object is a (potentially
+//   mutable) HeapObject and the data is an instance of ObjectData. Its handle
+//   must be persistent so that the GC can update it at a safepoint. Via this
+//   handle, the object can be accessed concurrently to the main thread. To be
+//   used the flag --concurrent-inlining must be on.
+//
+// kUnserializedReadOnlyHeapObject: The underlying V8 object is a read-only
+//   HeapObject and the data is an instance of ObjectData. For
+//   ReadOnlyHeapObjects, it is OK to access heap even from off-thread, so
+//   these objects need not be serialized.
+enum ObjectDataKind {
+  kSmi,
+  kSerializedHeapObject,
+  kBackgroundSerializedHeapObject,
+  kUnserializedHeapObject,
+  kNeverSerializedHeapObject,
+  kUnserializedReadOnlyHeapObject
+};
+
+namespace {
+
+bool IsReadOnlyHeapObjectForCompiler(HeapObject object) {
+  DisallowGarbageCollection no_gc;
+  // TODO(jgruber): Remove this compiler-specific predicate and use the plain
+  // heap predicate instead. This would involve removing the special cases for
+  // builtins.
+  return (object.IsCode() && Code::cast(object).is_builtin()) ||
+         (object.IsHeapObject() &&
+          ReadOnlyHeap::Contains(HeapObject::cast(object)));
+}
+
+}  // namespace
+
+class ObjectData : public ZoneObject {
+ public:
+  ObjectData(JSHeapBroker* broker, ObjectData** storage, Handle<Object> object,
+             ObjectDataKind kind)
+      : object_(object),
+        kind_(kind)
+#ifdef DEBUG
+        ,
+        broker_(broker)
+#endif  // DEBUG
+  {
+    // This assignment ensures we don't end up inserting the same object
+    // in an endless recursion.
+    *storage = this;
+
+    TRACE(broker, "Creating data " << this << " for handle " << object.address()
+                                   << " (" << Brief(*object) << ")");
+
+    // It is safe to access read only heap objects and builtins from a
+    // background thread. When we read fileds of these objects, we may create
+    // ObjectData on the background thread even without a canonical handle
+    // scope. This is safe too since we don't create handles but just get
+    // handles from read only root table or builtins table which is what
+    // canonical scope uses as well. For all other objects we should have
+    // created ObjectData in canonical handle scope on the main thread.
+    CHECK_IMPLIES(
+        broker->mode() == JSHeapBroker::kDisabled ||
+            broker->mode() == JSHeapBroker::kSerializing,
+        broker->isolate()->handle_scope_data()->canonical_scope != nullptr);
+    CHECK_IMPLIES(broker->mode() == JSHeapBroker::kSerialized,
+                  kind == kUnserializedReadOnlyHeapObject || kind == kSmi ||
+                      kind == kNeverSerializedHeapObject ||
+                      kind == kBackgroundSerializedHeapObject);
+    CHECK_IMPLIES(kind == kUnserializedReadOnlyHeapObject,
+                  object->IsHeapObject() && IsReadOnlyHeapObjectForCompiler(
+                                                HeapObject::cast(*object)));
+  }
+
+#define DECLARE_IS(Name, ...) bool Is##Name() const;
+  HEAP_BROKER_OBJECT_LIST(DECLARE_IS)
+#undef DECLARE_IS
+
+#define DECLARE_AS(Name, ...) Name##Data* As##Name();
+  HEAP_BROKER_OBJECT_LIST(DECLARE_AS)
+#undef DECLARE_AS
+
+  Handle<Object> object() const { return object_; }
+  ObjectDataKind kind() const { return kind_; }
+  bool is_smi() const { return kind_ == kSmi; }
+  bool should_access_heap() const {
+    return kind_ == kUnserializedHeapObject ||
+           kind_ == kNeverSerializedHeapObject ||
+           kind_ == kUnserializedReadOnlyHeapObject;
+  }
+  bool IsNull() const { return object_->IsNull(); }
+
+#ifdef DEBUG
+  enum class Usage{kUnused, kOnlyIdentityUsed, kDataUsed};
+  mutable Usage used_status = Usage::kUnused;
+
+  JSHeapBroker* broker() const { return broker_; }
+#endif  // DEBUG
+
+ private:
+  Handle<Object> const object_;
+  ObjectDataKind const kind_;
+#ifdef DEBUG
+  JSHeapBroker* const broker_;  // For DCHECKs.
+#endif                          // DEBUG
+};
+
+namespace {
+
+template <class T>
+constexpr bool IsSerializedRef() {
+  return ref_traits<T>::ref_serialization_kind ==
+         RefSerializationKind::kSerialized;
+}
+
+RefSerializationKind RefSerializationKindOf(ObjectData* const data) {
+  Object o = *data->object();
+  if (o.IsSmi()) {
+    return RefSerializationKind::kNeverSerialized;
+#define DEFINE_REF_SERIALIZATION_KIND(Name, Kind) \
+  }                                               \
+  /* NOLINTNEXTLINE(readability/braces) */        \
+  else if (o.Is##Name()) {                        \
+    return ref_traits<Name>::ref_serialization_kind;
+    HEAP_BROKER_OBJECT_LIST(DEFINE_REF_SERIALIZATION_KIND)
+#undef DEFINE_REF_SERIALIZATION_KIND
+  }
+  UNREACHABLE();
+}
+
+}  // namespace
+
+class HeapObjectData : public ObjectData {
+ public:
+  HeapObjectData(JSHeapBroker* broker, ObjectData** storage,
+                 Handle<HeapObject> object,
+                 ObjectDataKind kind = ObjectDataKind::kSerializedHeapObject);
+
+  base::Optional<bool> TryGetBooleanValue(JSHeapBroker* broker) const;
+  ObjectData* map() const { return map_; }
+  InstanceType GetMapInstanceType() const;
+
+ private:
+  base::Optional<bool> TryGetBooleanValueImpl(JSHeapBroker* broker) const;
+
+  ObjectData* const map_;
+};
+
+class PropertyCellData : public HeapObjectData {
+ public:
+  PropertyCellData(JSHeapBroker* broker, ObjectData** storage,
+                   Handle<PropertyCell> object,
+                   ObjectDataKind kind = ObjectDataKind::kSerializedHeapObject);
+
+  bool Serialize(JSHeapBroker* broker);
+
+  PropertyDetails property_details() const {
+    CHECK(serialized());
+    return property_details_;
+  }
+
+  ObjectData* value() const {
+    DCHECK(serialized());
+    return value_;
+  }
+
+ private:
+  PropertyDetails property_details_ = PropertyDetails::Empty();
+  ObjectData* value_ = nullptr;
+
+  bool serialized() const { return value_ != nullptr; }
+};
+
+// TODO(mslekova): Once we have real-world usage data, we might want to
+// reimplement this as sorted vector instead, to reduce the memory overhead.
+typedef ZoneMap<ObjectData*, HolderLookupResult> KnownReceiversMap;
+
+class FunctionTemplateInfoData : public HeapObjectData {
+ public:
+  FunctionTemplateInfoData(JSHeapBroker* broker, ObjectData** storage,
+                           Handle<FunctionTemplateInfo> object);
+
+  bool is_signature_undefined() const { return is_signature_undefined_; }
+  bool accept_any_receiver() const { return accept_any_receiver_; }
+  bool has_call_code() const { return has_call_code_; }
+
+  void SerializeCallCode(JSHeapBroker* broker);
+  ObjectData* call_code() const { return call_code_; }
+  ZoneVector<Address> c_functions() const { return c_functions_; }
+  ZoneVector<const CFunctionInfo*> c_signatures() const {
+    return c_signatures_;
+  }
+  KnownReceiversMap& known_receivers() { return known_receivers_; }
+
+ private:
+  bool is_signature_undefined_ = false;
+  bool accept_any_receiver_ = false;
+  bool has_call_code_ = false;
+
+  ObjectData* call_code_ = nullptr;
+  ZoneVector<Address> c_functions_;
+  ZoneVector<const CFunctionInfo*> c_signatures_;
+  KnownReceiversMap known_receivers_;
+};
+
+class CallHandlerInfoData : public HeapObjectData {
+ public:
+  CallHandlerInfoData(JSHeapBroker* broker, ObjectData** storage,
+                      Handle<CallHandlerInfo> object);
+
+  Address callback() const { return callback_; }
+
+  void Serialize(JSHeapBroker* broker);
+  ObjectData* data() const { return data_; }
+
+ private:
+  Address const callback_;
+
+  ObjectData* data_ = nullptr;
+};
+
+namespace {
+
+ZoneVector<Address> GetCFunctions(FixedArray function_overloads, Zone* zone) {
+  const int len = function_overloads.length() /
+                  FunctionTemplateInfo::kFunctionOverloadEntrySize;
+  ZoneVector<Address> c_functions = ZoneVector<Address>(len, zone);
+  for (int i = 0; i < len; i++) {
+    c_functions[i] = v8::ToCData<Address>(function_overloads.get(
+        FunctionTemplateInfo::kFunctionOverloadEntrySize * i));
+  }
+  return c_functions;
+}
+
+ZoneVector<const CFunctionInfo*> GetCSignatures(FixedArray function_overloads,
+                                                Zone* zone) {
+  const int len = function_overloads.length() /
+                  FunctionTemplateInfo::kFunctionOverloadEntrySize;
+  ZoneVector<const CFunctionInfo*> c_signatures =
+      ZoneVector<const CFunctionInfo*>(len, zone);
+  for (int i = 0; i < len; i++) {
+    c_signatures[i] = v8::ToCData<const CFunctionInfo*>(function_overloads.get(
+        FunctionTemplateInfo::kFunctionOverloadEntrySize * i + 1));
+  }
+  return c_signatures;
+}
+
+}  // namespace
+
+FunctionTemplateInfoData::FunctionTemplateInfoData(
+    JSHeapBroker* broker, ObjectData** storage,
+    Handle<FunctionTemplateInfo> object)
+    : HeapObjectData(broker, storage, object),
+      c_functions_(broker->zone()),
+      c_signatures_(broker->zone()),
+      known_receivers_(broker->zone()) {
+  DCHECK(!broker->is_concurrent_inlining());
+
+  auto function_template_info = Handle<FunctionTemplateInfo>::cast(object);
+
+  FixedArray function_overloads_array =
+      FixedArray::cast(function_template_info->GetCFunctionOverloads());
+  c_functions_ = GetCFunctions(function_overloads_array, broker->zone());
+  c_signatures_ = GetCSignatures(function_overloads_array, broker->zone());
+
+  is_signature_undefined_ =
+      function_template_info->signature().IsUndefined(broker->isolate());
+  accept_any_receiver_ = function_template_info->accept_any_receiver();
+
+  CallOptimization call_optimization(broker->local_isolate_or_isolate(),
+                                     object);
+  has_call_code_ = call_optimization.is_simple_api_call();
+}
+
+CallHandlerInfoData::CallHandlerInfoData(JSHeapBroker* broker,
+                                         ObjectData** storage,
+                                         Handle<CallHandlerInfo> object)
+    : HeapObjectData(broker, storage, object),
+      callback_(v8::ToCData<Address>(object->callback())) {
+  DCHECK(!broker->is_concurrent_inlining());
+}
+
+PropertyCellData::PropertyCellData(JSHeapBroker* broker, ObjectData** storage,
+                                   Handle<PropertyCell> object,
+                                   ObjectDataKind kind)
+    : HeapObjectData(broker, storage, object, kind) {}
+
+bool PropertyCellData::Serialize(JSHeapBroker* broker) {
+  if (serialized()) return true;
+
+  TraceScope tracer(broker, this, "PropertyCellData::Serialize");
+  auto cell = Handle<PropertyCell>::cast(object());
+
+  // While this code runs on a background thread, the property cell might
+  // undergo state transitions via calls to PropertyCell::Transition. These
+  // transitions follow a certain protocol on which we rely here to ensure that
+  // we only report success when we can guarantee consistent data. A key
+  // property is that after transitioning from cell type A to B (A != B), there
+  // will never be a transition back to A, unless A is kConstant and the new
+  // value is the hole (i.e. the property cell was invalidated, which is a final
+  // state).
+
+  PropertyDetails property_details = cell->property_details(kAcquireLoad);
+
+  Handle<Object> value =
+      broker->CanonicalPersistentHandle(cell->value(kAcquireLoad));
+  if (broker->ObjectMayBeUninitialized(value)) {
+    DCHECK(!broker->IsMainThread());
+    return false;
+  }
+
+  {
+    PropertyDetails property_details_again =
+        cell->property_details(kAcquireLoad);
+    if (property_details != property_details_again) {
+      DCHECK(!broker->IsMainThread());
+      return false;
+    }
+  }
+
+  if (property_details.cell_type() == PropertyCellType::kConstant) {
+    Handle<Object> value_again =
+        broker->CanonicalPersistentHandle(cell->value(kAcquireLoad));
+    if (*value != *value_again) {
+      DCHECK(!broker->IsMainThread());
+      return false;
+    }
+  }
+
+  ObjectData* value_data = broker->TryGetOrCreateData(value);
+  if (value_data == nullptr) {
+    DCHECK(!broker->IsMainThread());
+    return false;
+  }
+
+  PropertyCell::CheckDataIsCompatible(property_details, *value);
+
+  DCHECK(!serialized());
+  property_details_ = property_details;
+  value_ = value_data;
+  DCHECK(serialized());
+  return true;
+}
+
+void FunctionTemplateInfoData::SerializeCallCode(JSHeapBroker* broker) {
+  if (call_code_ != nullptr) return;
+
+  TraceScope tracer(broker, this,
+                    "FunctionTemplateInfoData::SerializeCallCode");
+  auto function_template_info = Handle<FunctionTemplateInfo>::cast(object());
+  call_code_ =
+      broker->GetOrCreateData(function_template_info->call_code(kAcquireLoad));
+  if (call_code_->should_access_heap()) {
+    // TODO(mvstanton): When ObjectRef is in the never serialized list, this
+    // code can be removed.
+    broker->GetOrCreateData(
+        Handle<CallHandlerInfo>::cast(call_code_->object())->data());
+  } else {
+    call_code_->AsCallHandlerInfo()->Serialize(broker);
+  }
+}
+
+void CallHandlerInfoData::Serialize(JSHeapBroker* broker) {
+  if (data_ != nullptr) return;
+
+  TraceScope tracer(broker, this, "CallHandlerInfoData::Serialize");
+  auto call_handler_info = Handle<CallHandlerInfo>::cast(object());
+  data_ = broker->GetOrCreateData(call_handler_info->data());
+}
+
+class JSReceiverData : public HeapObjectData {
+ public:
+  JSReceiverData(JSHeapBroker* broker, ObjectData** storage,
+                 Handle<JSReceiver> object, ObjectDataKind kind)
+      : HeapObjectData(broker, storage, object, kind) {}
+};
+
+class JSObjectData : public JSReceiverData {
+ public:
+  JSObjectData(JSHeapBroker* broker, ObjectData** storage,
+               Handle<JSObject> object);
+
+  // Recursive serialization of all reachable JSObjects.
+  void SerializeAsBoilerplate(JSHeapBroker* broker);
+  ObjectData* GetInobjectField(int property_index) const;
+
+  // Shallow serialization of {elements}.
+  void SerializeElements(JSHeapBroker* broker);
+  bool serialized_elements() const { return serialized_elements_; }
+  ObjectData* elements() const;
+
+  void SerializeObjectCreateMap(JSHeapBroker* broker);
+
+  ObjectData* object_create_map(
+      JSHeapBroker* broker) const {  // Can be nullptr.
+    if (!serialized_object_create_map_) {
+      DCHECK_NULL(object_create_map_);
+      TRACE_MISSING(broker, "object_create_map on " << this);
+    }
+    return object_create_map_;
+  }
+
+  ObjectData* GetOwnConstantElement(
+      JSHeapBroker* broker, uint32_t index,
+      SerializationPolicy policy = SerializationPolicy::kAssumeSerialized);
+  ObjectData* GetOwnFastDataProperty(
+      JSHeapBroker* broker, Representation representation,
+      FieldIndex field_index,
+      SerializationPolicy policy = SerializationPolicy::kAssumeSerialized);
+  ObjectData* GetOwnDictionaryProperty(JSHeapBroker* broker,
+                                       InternalIndex dict_index,
+                                       SerializationPolicy policy);
+
+  // This method is only used to assert our invariants.
+  bool cow_or_empty_elements_tenured() const;
+
+ private:
+  void SerializeRecursiveAsBoilerplate(JSHeapBroker* broker, int max_depths);
+
+  ObjectData* elements_ = nullptr;
+  bool cow_or_empty_elements_tenured_ = false;
+  // The {serialized_as_boilerplate} flag is set when all recursively
+  // reachable JSObjects are serialized.
+  bool serialized_as_boilerplate_ = false;
+  bool serialized_elements_ = false;
+
+  ZoneVector<ObjectData*> inobject_fields_;
+
+  bool serialized_object_create_map_ = false;
+  ObjectData* object_create_map_ = nullptr;
+
+  // Elements (indexed properties) that either
+  // (1) are known to exist directly on the object as non-writable and
+  // non-configurable, or (2) are known not to (possibly they don't exist at
+  // all). In case (2), the second pair component is nullptr.
+  ZoneVector<std::pair<uint32_t, ObjectData*>> own_constant_elements_;
+  // Properties that either:
+  // (1) are known to exist directly on the object, or
+  // (2) are known not to (possibly they don't exist at all).
+  // In case (2), the second pair component is nullptr.
+  // For simplicity, this may in theory overlap with inobject_fields_.
+  // For fast mode objects, the keys of the map are the property_index() values
+  // of the respective property FieldIndex'es. For slow mode objects, the keys
+  // are the dictionary indicies.
+  ZoneUnorderedMap<int, ObjectData*> own_properties_;
+};
+
+void JSObjectData::SerializeObjectCreateMap(JSHeapBroker* broker) {
+  if (serialized_object_create_map_) return;
+  serialized_object_create_map_ = true;
+
+  TraceScope tracer(broker, this, "JSObjectData::SerializeObjectCreateMap");
+  Handle<JSObject> jsobject = Handle<JSObject>::cast(object());
+
+  if (jsobject->map().is_prototype_map()) {
+    Handle<Object> maybe_proto_info(jsobject->map().prototype_info(),
+                                    broker->isolate());
+    if (maybe_proto_info->IsPrototypeInfo()) {
+      auto proto_info = Handle<PrototypeInfo>::cast(maybe_proto_info);
+      if (proto_info->HasObjectCreateMap()) {
+        DCHECK_NULL(object_create_map_);
+        object_create_map_ =
+            broker->GetOrCreateData(proto_info->ObjectCreateMap());
+      }
+    }
+  }
+}
+
+namespace {
+
+base::Optional<ObjectRef> GetOwnElementFromHeap(JSHeapBroker* broker,
+                                                Handle<Object> receiver,
+                                                uint32_t index,
+                                                bool constant_only) {
+  LookupIterator it(broker->isolate(), receiver, index, LookupIterator::OWN);
+  if (it.state() == LookupIterator::DATA &&
+      (!constant_only || (it.IsReadOnly() && !it.IsConfigurable()))) {
+    return MakeRef(broker, it.GetDataValue());
+  }
+  return base::nullopt;
+}
+
+ObjectRef GetOwnFastDataPropertyFromHeap(JSHeapBroker* broker,
+                                         Handle<JSObject> receiver,
+                                         Representation representation,
+                                         FieldIndex field_index) {
+  Handle<Object> constant =
+      JSObject::FastPropertyAt(receiver, representation, field_index);
+  return ObjectRef(broker, constant);
+}
+
+ObjectRef GetOwnDictionaryPropertyFromHeap(JSHeapBroker* broker,
+                                           Handle<JSObject> receiver,
+                                           InternalIndex dict_index) {
+  Handle<Object> constant =
+      JSObject::DictionaryPropertyAt(receiver, dict_index);
+  return ObjectRef(broker, constant);
+}
+
+}  // namespace
+
+ObjectData* JSObjectData::GetOwnConstantElement(JSHeapBroker* broker,
+                                                uint32_t index,
+                                                SerializationPolicy policy) {
+  for (auto const& p : own_constant_elements_) {
+    if (p.first == index) return p.second;
+  }
+
+  if (policy == SerializationPolicy::kAssumeSerialized) {
+    TRACE_MISSING(broker, "knowledge about index " << index << " on " << this);
+    return nullptr;
+  }
+
+  base::Optional<ObjectRef> element =
+      GetOwnElementFromHeap(broker, object(), index, true);
+  ObjectData* result = element.has_value() ? element->data() : nullptr;
+  own_constant_elements_.push_back({index, result});
+  return result;
+}
+
+ObjectData* JSObjectData::GetOwnFastDataProperty(JSHeapBroker* broker,
+                                                 Representation representation,
+                                                 FieldIndex field_index,
+                                                 SerializationPolicy policy) {
+  auto p = own_properties_.find(field_index.property_index());
+  if (p != own_properties_.end()) return p->second;
+
+  if (policy == SerializationPolicy::kAssumeSerialized) {
+    TRACE_MISSING(broker, "knowledge about fast property with index "
+                              << field_index.property_index() << " on "
+                              << this);
+    return nullptr;
+  }
+
+  ObjectRef property = GetOwnFastDataPropertyFromHeap(
+      broker, Handle<JSObject>::cast(object()), representation, field_index);
+  ObjectData* result(property.data());
+  own_properties_.insert(std::make_pair(field_index.property_index(), result));
+  return result;
+}
+
+ObjectData* JSObjectData::GetOwnDictionaryProperty(JSHeapBroker* broker,
+                                                   InternalIndex dict_index,
+                                                   SerializationPolicy policy) {
+  auto p = own_properties_.find(dict_index.as_int());
+  if (p != own_properties_.end()) return p->second;
+
+  if (policy == SerializationPolicy::kAssumeSerialized) {
+    TRACE_MISSING(broker, "knowledge about dictionary property with index "
+                              << dict_index.as_int() << " on " << this);
+    return nullptr;
+  }
+
+  ObjectRef property = GetOwnDictionaryPropertyFromHeap(
+      broker, Handle<JSObject>::cast(object()), dict_index);
+  ObjectData* result(property.data());
+  own_properties_.insert(std::make_pair(dict_index.as_int(), result));
+  return result;
+}
+
+class JSTypedArrayData : public JSObjectData {
+ public:
+  JSTypedArrayData(JSHeapBroker* broker, ObjectData** storage,
+                   Handle<JSTypedArray> object)
+      : JSObjectData(broker, storage, object) {}
+
+  // TODO(v8:7790): Once JSObject is no longer serialized, also make
+  // JSTypedArrayRef never-serialized.
+  STATIC_ASSERT(IsSerializedRef<JSObject>());
+
+  void Serialize(JSHeapBroker* broker);
+  bool serialized() const { return serialized_; }
+
+  bool is_on_heap() const { return is_on_heap_; }
+  size_t length() const { return length_; }
+  void* data_ptr() const { return data_ptr_; }
+
+  ObjectData* buffer() const { return buffer_; }
+
+ private:
+  bool serialized_ = false;
+  bool is_on_heap_ = false;
+  size_t length_ = 0;
+  void* data_ptr_ = nullptr;
+  ObjectData* buffer_ = nullptr;
+};
+
+void JSTypedArrayData::Serialize(JSHeapBroker* broker) {
+  if (serialized_) return;
+  serialized_ = true;
+
+  TraceScope tracer(broker, this, "JSTypedArrayData::Serialize");
+  Handle<JSTypedArray> typed_array = Handle<JSTypedArray>::cast(object());
+
+  is_on_heap_ = typed_array->is_on_heap();
+  length_ = typed_array->length();
+  data_ptr_ = typed_array->DataPtr();
+
+  if (!is_on_heap()) {
+    DCHECK_NULL(buffer_);
+    buffer_ = broker->GetOrCreateData(typed_array->buffer());
+  }
+}
+
+class ArrayBoilerplateDescriptionData : public HeapObjectData {
+ public:
+  ArrayBoilerplateDescriptionData(JSHeapBroker* broker, ObjectData** storage,
+                                  Handle<ArrayBoilerplateDescription> object)
+      : HeapObjectData(broker, storage, object),
+        constants_elements_length_(object->constant_elements().length()) {
+    DCHECK(!broker->is_concurrent_inlining());
+  }
+
+  int constants_elements_length() const { return constants_elements_length_; }
+
+ private:
+  int const constants_elements_length_;
+};
+
+class JSDataViewData : public JSObjectData {
+ public:
+  JSDataViewData(JSHeapBroker* broker, ObjectData** storage,
+                 Handle<JSDataView> object);
+
+  size_t byte_length() const { return byte_length_; }
+
+ private:
+  size_t const byte_length_;
+};
+
+class JSBoundFunctionData : public JSObjectData {
+ public:
+  JSBoundFunctionData(JSHeapBroker* broker, ObjectData** storage,
+                      Handle<JSBoundFunction> object);
+
+  bool Serialize(JSHeapBroker* broker);
+  bool serialized() const { return serialized_; }
+
+  ObjectData* bound_target_function() const {
+    DCHECK(!broker()->is_concurrent_inlining());
+    return bound_target_function_;
+  }
+  ObjectData* bound_this() const {
+    DCHECK(!broker()->is_concurrent_inlining());
+    return bound_this_;
+  }
+  ObjectData* bound_arguments() const {
+    DCHECK(!broker()->is_concurrent_inlining());
+    return bound_arguments_;
+  }
+
+ private:
+  bool serialized_ = false;
+
+  ObjectData* bound_target_function_ = nullptr;
+  ObjectData* bound_this_ = nullptr;
+  ObjectData* bound_arguments_ = nullptr;
+};
+
+class JSFunctionData : public JSObjectData {
+ public:
+  JSFunctionData(JSHeapBroker* broker, ObjectData** storage,
+                 Handle<JSFunction> object);
+
+  bool has_feedback_vector() const { return has_feedback_vector_; }
+  bool has_initial_map() const { return has_initial_map_; }
+  bool has_prototype() const { return has_prototype_; }
+  bool PrototypeRequiresRuntimeLookup() const {
+    return PrototypeRequiresRuntimeLookup_;
+  }
+
+  void Serialize(JSHeapBroker* broker);
+  bool serialized() const { return serialized_; }
+
+  void SerializeCodeAndFeedback(JSHeapBroker* broker);
+  bool serialized_code_and_feedback() const {
+    return serialized_code_and_feedback_;
+  }
+
+  ObjectData* context() const { return context_; }
+  ObjectData* native_context() const { return native_context_; }
+  ObjectData* initial_map() const { return initial_map_; }
+  ObjectData* prototype() const { return prototype_; }
+  ObjectData* shared() const { return shared_; }
+  ObjectData* raw_feedback_cell() const {
+    DCHECK(serialized_code_and_feedback());
+    return feedback_cell_;
+  }
+  ObjectData* feedback_vector() const {
+    DCHECK(serialized_code_and_feedback());
+    return feedback_vector_;
+  }
+  ObjectData* code() const {
+    DCHECK(serialized_code_and_feedback());
+    DCHECK(!broker()->is_concurrent_inlining());
+    return code_;
+  }
+  int initial_map_instance_size_with_min_slack() const {
+    CHECK(serialized_);
+    return initial_map_instance_size_with_min_slack_;
+  }
+
+ private:
+  bool has_feedback_vector_;
+  bool has_initial_map_;
+  bool has_prototype_;
+  bool PrototypeRequiresRuntimeLookup_;
+
+  bool serialized_ = false;
+  bool serialized_code_and_feedback_ = false;
+
+  ObjectData* context_ = nullptr;
+  ObjectData* native_context_ = nullptr;
+  ObjectData* initial_map_ = nullptr;
+  ObjectData* prototype_ = nullptr;
+  ObjectData* shared_ = nullptr;
+  ObjectData* feedback_vector_ = nullptr;
+  ObjectData* feedback_cell_ = nullptr;
+  ObjectData* code_ = nullptr;
+  int initial_map_instance_size_with_min_slack_;
+};
+
+class RegExpBoilerplateDescriptionData : public HeapObjectData {
+ public:
+  RegExpBoilerplateDescriptionData(JSHeapBroker* broker, ObjectData** storage,
+                                   Handle<RegExpBoilerplateDescription> object)
+      : HeapObjectData(broker, storage, object) {}
+
+  void Serialize(JSHeapBroker* broker);
+  ObjectData* data() const {
+    CHECK(serialized_);
+    return data_;
+  }
+  ObjectData* source() const {
+    CHECK(serialized_);
+    return source_;
+  }
+  int flags() const {
+    CHECK(serialized_);
+    return flags_;
+  }
+
+ private:
+  bool serialized_ = false;
+  ObjectData* data_ = nullptr;
+  ObjectData* source_ = nullptr;
+  int flags_;
+};
+
+class HeapNumberData : public HeapObjectData {
+ public:
+  HeapNumberData(JSHeapBroker* broker, ObjectData** storage,
+                 Handle<HeapNumber> object,
+                 ObjectDataKind kind = ObjectDataKind::kSerializedHeapObject)
+      : HeapObjectData(broker, storage, object, kind),
+        value_(object->value()) {}
+
+  double value() const { return value_; }
+
+ private:
+  double const value_;
+};
+
+class ContextData : public HeapObjectData {
+ public:
+  ContextData(JSHeapBroker* broker, ObjectData** storage,
+              Handle<Context> object);
+
+  ObjectData* previous(
+      JSHeapBroker* broker,
+      SerializationPolicy policy = SerializationPolicy::kAssumeSerialized);
+
+  // Returns nullptr if the slot index isn't valid or wasn't serialized,
+  // unless {policy} is {kSerializeIfNeeded}.
+  ObjectData* GetSlot(
+      JSHeapBroker* broker, int index,
+      SerializationPolicy policy = SerializationPolicy::kAssumeSerialized);
+
+ private:
+  ZoneMap<int, ObjectData*> slots_;
+  ObjectData* previous_ = nullptr;
+};
+
+ContextData::ContextData(JSHeapBroker* broker, ObjectData** storage,
+                         Handle<Context> object)
+    : HeapObjectData(broker, storage, object), slots_(broker->zone()) {}
+
+ObjectData* ContextData::previous(JSHeapBroker* broker,
+                                  SerializationPolicy policy) {
+  if (policy == SerializationPolicy::kSerializeIfNeeded &&
+      previous_ == nullptr) {
+    TraceScope tracer(broker, this, "ContextData::previous");
+    Handle<Context> context = Handle<Context>::cast(object());
+    previous_ = broker->GetOrCreateData(context->unchecked_previous());
+  }
+  return previous_;
+}
+
+ObjectData* ContextData::GetSlot(JSHeapBroker* broker, int index,
+                                 SerializationPolicy policy) {
+  DCHECK_GE(index, 0);
+  auto search = slots_.find(index);
+  if (search != slots_.end()) {
+    return search->second;
+  }
+
+  if (policy == SerializationPolicy::kSerializeIfNeeded) {
+    Handle<Context> context = Handle<Context>::cast(object());
+    if (index < context->length()) {
+      TraceScope tracer(broker, this, "ContextData::GetSlot");
+      TRACE(broker, "Serializing context slot " << index);
+      ObjectData* odata = broker->GetOrCreateData(context->get(index));
+      slots_.insert(std::make_pair(index, odata));
+      return odata;
+    }
+  }
+
+  return nullptr;
+}
+
+class NativeContextData : public ContextData {
+ public:
+#define DECL_ACCESSOR(type, name) \
+  ObjectData* name() const { return name##_; }
+  BROKER_NATIVE_CONTEXT_FIELDS(DECL_ACCESSOR)
+#undef DECL_ACCESSOR
+
+  const ZoneVector<ObjectData*>& function_maps() const {
+    CHECK_NE(state_, State::kUnserialized);
+    return function_maps_;
+  }
+
+  ObjectData* scope_info() const {
+    CHECK_NE(state_, State::kUnserialized);
+    return scope_info_;
+  }
+
+  NativeContextData(JSHeapBroker* broker, ObjectData** storage,
+                    Handle<NativeContext> object);
+  void Serialize(JSHeapBroker* broker);
+  void SerializeOnBackground(JSHeapBroker* broker);
+
+ private:
+  // After Serialize is called the class is partially serialized and it the
+  // kSerializedOnMainThread state. It then becomes kFullySerialized once
+  // SerializeOnBackground is called.
+  enum class State { kUnserialized, kSerializedOnMainThread, kFullySerialized };
+  State state_;
+
+#define DECL_MEMBER(type, name) ObjectData* name##_ = nullptr;
+  BROKER_NATIVE_CONTEXT_FIELDS(DECL_MEMBER)
+#undef DECL_MEMBER
+  ZoneVector<ObjectData*> function_maps_;
+  ObjectData* scope_info_ = nullptr;
+};
+
+class NameData : public HeapObjectData {
+ public:
+  NameData(JSHeapBroker* broker, ObjectData** storage, Handle<Name> object)
+      : HeapObjectData(broker, storage, object) {
+    DCHECK(!broker->is_concurrent_inlining());
+  }
+};
+
+class StringData : public NameData {
+ public:
+  StringData(JSHeapBroker* broker, ObjectData** storage, Handle<String> object);
+
+  int length() const { return length_; }
+  uint16_t first_char() const { return first_char_; }
+  base::Optional<double> to_number() const { return to_number_; }
+  bool is_external_string() const { return is_external_string_; }
+  bool is_seq_string() const { return is_seq_string_; }
+
+  ObjectData* GetCharAsStringOrUndefined(
+      JSHeapBroker* broker, uint32_t index,
+      SerializationPolicy policy = SerializationPolicy::kAssumeSerialized);
+
+ private:
+  int const length_;
+  uint16_t const first_char_;
+  base::Optional<double> to_number_;
+  bool const is_external_string_;
+  bool const is_seq_string_;
+
+  // Known individual characters as strings, corresponding to the semantics of
+  // element access (s[i]). The first pair component is always less than
+  // {length_}. The second component is never nullptr.
+  ZoneVector<std::pair<uint32_t, ObjectData*>> chars_as_strings_;
+};
+
+class SymbolData : public NameData {
+ public:
+  SymbolData(JSHeapBroker* broker, ObjectData** storage, Handle<Symbol> object)
+      : NameData(broker, storage, object) {
+    DCHECK(!broker->is_concurrent_inlining());
+  }
+};
+
+StringData::StringData(JSHeapBroker* broker, ObjectData** storage,
+                       Handle<String> object)
+    : NameData(broker, storage, object),
+      length_(object->length()),
+      first_char_(length_ > 0 ? object->Get(0) : 0),
+      to_number_(TryStringToDouble(broker->local_isolate(), object)),
+      is_external_string_(object->IsExternalString()),
+      is_seq_string_(object->IsSeqString()),
+      chars_as_strings_(broker->zone()) {
+  DCHECK(!broker->is_concurrent_inlining());
+}
+
+class InternalizedStringData : public StringData {
+ public:
+  InternalizedStringData(JSHeapBroker* broker, ObjectData** storage,
+                         Handle<InternalizedString> object)
+      : StringData(broker, storage, object) {
+    DCHECK(!broker->is_concurrent_inlining());
+  }
+};
+
+ObjectData* StringData::GetCharAsStringOrUndefined(JSHeapBroker* broker,
+                                                   uint32_t index,
+                                                   SerializationPolicy policy) {
+  if (index >= static_cast<uint32_t>(length())) return nullptr;
+
+  for (auto const& p : chars_as_strings_) {
+    if (p.first == index) return p.second;
+  }
+
+  if (policy == SerializationPolicy::kAssumeSerialized) {
+    TRACE_MISSING(broker, "knowledge about index " << index << " on " << this);
+    return nullptr;
+  }
+
+  base::Optional<ObjectRef> element =
+      GetOwnElementFromHeap(broker, object(), index, true);
+  ObjectData* result = element.has_value() ? element->data() : nullptr;
+  chars_as_strings_.push_back({index, result});
+  return result;
+}
+
+namespace {
+
+bool IsFastLiteralHelper(Handle<JSObject> boilerplate, int max_depth,
+                         int* max_properties) {
+  DCHECK_GE(max_depth, 0);
+  DCHECK_GE(*max_properties, 0);
+
+  // Check for too deep nesting.
+  if (max_depth == 0) return false;
+
+  Isolate* const isolate = boilerplate->GetIsolate();
+
+  // If the boilerplate map has been deprecated, bailout of fast literal
+  // optimization.  The map could be deprecated at some point after the line
+  // below, but it's not a correctness issue -- it only means the literal isn't
+  // created with the most up to date map(s).
+  if (boilerplate->map().is_deprecated()) return false;
+
+  // Check the elements.
+  Handle<FixedArrayBase> elements(boilerplate->elements(), isolate);
+  if (elements->length() > 0 &&
+      elements->map() != ReadOnlyRoots(isolate).fixed_cow_array_map()) {
+    if (boilerplate->HasSmiOrObjectElements()) {
+      Handle<FixedArray> fast_elements = Handle<FixedArray>::cast(elements);
+      int length = elements->length();
+      for (int i = 0; i < length; i++) {
+        if ((*max_properties)-- == 0) return false;
+        Handle<Object> value(fast_elements->get(i), isolate);
+        if (value->IsJSObject()) {
+          Handle<JSObject> value_object = Handle<JSObject>::cast(value);
+          if (!IsFastLiteralHelper(value_object, max_depth - 1,
+                                   max_properties)) {
+            return false;
+          }
+        }
+      }
+    } else if (boilerplate->HasDoubleElements()) {
+      if (elements->Size() > kMaxRegularHeapObjectSize) return false;
+    } else {
+      return false;
+    }
+  }
+
+  // TODO(turbofan): Do we want to support out-of-object properties?
+  if (!(boilerplate->HasFastProperties() &&
+        boilerplate->property_array().length() == 0)) {
+    return false;
+  }
+
+  // Check the in-object properties.
+  Handle<DescriptorArray> descriptors(
+      boilerplate->map().instance_descriptors(isolate, kRelaxedLoad), isolate);
+  for (InternalIndex i : boilerplate->map().IterateOwnDescriptors()) {
+    PropertyDetails details = descriptors->GetDetails(i);
+    if (details.location() != kField) continue;
+    DCHECK_EQ(kData, details.kind());
+    if ((*max_properties)-- == 0) return false;
+    FieldIndex field_index = FieldIndex::ForDescriptor(boilerplate->map(), i);
+    Handle<Object> value(boilerplate->RawFastPropertyAt(field_index), isolate);
+    if (value->IsJSObject()) {
+      Handle<JSObject> value_object = Handle<JSObject>::cast(value);
+      if (!IsFastLiteralHelper(value_object, max_depth - 1, max_properties)) {
+        return false;
+      }
+    }
+  }
+  return true;
+}
+
+// Maximum depth and total number of elements and properties for literal
+// graphs to be considered for fast deep-copying. The limit is chosen to
+// match the maximum number of inobject properties, to ensure that the
+// performance of using object literals is not worse than using constructor
+// functions, see crbug.com/v8/6211 for details.
+const int kMaxFastLiteralDepth = 3;
+const int kMaxFastLiteralProperties = JSObject::kMaxInObjectProperties;
+
+// Determines whether the given array or object literal boilerplate satisfies
+// all limits to be considered for fast deep-copying and computes the total
+// size of all objects that are part of the graph.
+bool IsInlinableFastLiteral(Handle<JSObject> boilerplate) {
+  int max_properties = kMaxFastLiteralProperties;
+  return IsFastLiteralHelper(boilerplate, kMaxFastLiteralDepth,
+                             &max_properties);
+}
+
+}  // namespace
+
+class AccessorInfoData : public HeapObjectData {
+ public:
+  AccessorInfoData(JSHeapBroker* broker, ObjectData** storage,
+                   Handle<AccessorInfo> object);
+};
+
+class AllocationSiteData : public HeapObjectData {
+ public:
+  AllocationSiteData(JSHeapBroker* broker, ObjectData** storage,
+                     Handle<AllocationSite> object);
+  void SerializeBoilerplate(JSHeapBroker* broker);
+
+  bool PointsToLiteral() const { return PointsToLiteral_; }
+  AllocationType GetAllocationType() const { return GetAllocationType_; }
+  ObjectData* nested_site() const { return nested_site_; }
+  bool IsFastLiteral() const { return IsFastLiteral_; }
+  ObjectData* boilerplate() const { return boilerplate_; }
+
+  // These are only valid if PointsToLiteral is false.
+  ElementsKind GetElementsKind() const { return GetElementsKind_; }
+  bool CanInlineCall() const { return CanInlineCall_; }
+
+ private:
+  bool const PointsToLiteral_;
+  AllocationType const GetAllocationType_;
+  ObjectData* nested_site_ = nullptr;
+  bool IsFastLiteral_ = false;
+  ObjectData* boilerplate_ = nullptr;
+  ElementsKind GetElementsKind_ = NO_ELEMENTS;
+  bool CanInlineCall_ = false;
+  bool serialized_boilerplate_ = false;
+};
+
+class BigIntData : public HeapObjectData {
+ public:
+  BigIntData(JSHeapBroker* broker, ObjectData** storage, Handle<BigInt> object,
+             ObjectDataKind kind)
+      : HeapObjectData(broker, storage, object, kind),
+        as_uint64_(object->AsUint64(nullptr)) {}
+
+  uint64_t AsUint64() const { return as_uint64_; }
+
+ private:
+  const uint64_t as_uint64_;
+};
+
+struct PropertyDescriptor {
+  ObjectData* key = nullptr;
+  ObjectData* value = nullptr;
+  PropertyDetails details = PropertyDetails::Empty();
+  FieldIndex field_index;
+  ObjectData* field_owner = nullptr;
+  ObjectData* field_type = nullptr;
+};
+
+class MapData : public HeapObjectData {
+ public:
+  MapData(JSHeapBroker* broker, ObjectData** storage, Handle<Map> object,
+          ObjectDataKind kind = ObjectDataKind::kSerializedHeapObject);
+
+  InstanceType instance_type() const { return instance_type_; }
+  int instance_size() const { return instance_size_; }
+  byte bit_field() const { return bit_field_; }
+  byte bit_field2() const { return bit_field2_; }
+  uint32_t bit_field3() const { return bit_field3_; }
+  bool can_be_deprecated() const { return can_be_deprecated_; }
+  bool can_transition() const { return can_transition_; }
+  int in_object_properties_start_in_words() const {
+    CHECK(InstanceTypeChecker::IsJSObject(instance_type()));
+    return in_object_properties_start_in_words_;
+  }
+  int in_object_properties() const {
+    CHECK(InstanceTypeChecker::IsJSObject(instance_type()));
+    return in_object_properties_;
+  }
+  int constructor_function_index() const { return constructor_function_index_; }
+  int NextFreePropertyIndex() const { return next_free_property_index_; }
+  int UnusedPropertyFields() const { return unused_property_fields_; }
+  bool supports_fast_array_iteration() const {
+    return supports_fast_array_iteration_;
+  }
+  bool supports_fast_array_resize() const {
+    return supports_fast_array_resize_;
+  }
+  bool is_abandoned_prototype_map() const {
+    return is_abandoned_prototype_map_;
+  }
+
+  // Extra information.
+
+  void SerializeElementsKindGeneralizations(JSHeapBroker* broker);
+  const ZoneVector<ObjectData*>& elements_kind_generalizations() const {
+    CHECK(serialized_elements_kind_generalizations_);
+    return elements_kind_generalizations_;
+  }
+
+  // Serialize a single (or all) own slot(s) of the descriptor array and recurse
+  // on field owner(s).
+  bool TrySerializeOwnDescriptor(JSHeapBroker* broker,
+                                 InternalIndex descriptor_index);
+  void SerializeOwnDescriptor(JSHeapBroker* broker,
+                              InternalIndex descriptor_index) {
+    CHECK(TrySerializeOwnDescriptor(broker, descriptor_index));
+  }
+  void SerializeOwnDescriptors(JSHeapBroker* broker);
+  ObjectData* GetStrongValue(InternalIndex descriptor_index) const;
+  ObjectData* instance_descriptors() const { return instance_descriptors_; }
+
+  void SerializeRootMap(JSHeapBroker* broker);
+  ObjectData* FindRootMap() const;
+
+  void SerializeConstructor(JSHeapBroker* broker);
+  ObjectData* GetConstructor() const {
+    CHECK(serialized_constructor_);
+    return constructor_;
+  }
+
+  void SerializeBackPointer(JSHeapBroker* broker);
+  ObjectData* GetBackPointer() const {
+    CHECK(serialized_backpointer_);
+    return backpointer_;
+  }
+
+  bool TrySerializePrototype(JSHeapBroker* broker);
+  void SerializePrototype(JSHeapBroker* broker) {
+    CHECK(TrySerializePrototype(broker));
+  }
+  ObjectData* prototype() const {
+    DCHECK_EQ(serialized_prototype_, prototype_ != nullptr);
+    return prototype_;
+  }
+
+  void SerializeForElementLoad(JSHeapBroker* broker);
+
+  void SerializeForElementStore(JSHeapBroker* broker);
+
+  bool has_extra_serialized_data() const {
+    return serialized_elements_kind_generalizations_ ||
+           serialized_own_descriptors_ || serialized_constructor_ ||
+           serialized_backpointer_ || serialized_prototype_ ||
+           serialized_root_map_ || serialized_for_element_load_ ||
+           serialized_for_element_store_;
+  }
+
+ private:
+  // The following fields should be const in principle, but construction
+  // requires locking the MapUpdater lock. For this reason, it's easier to
+  // initialize these inside the constructor body, not in the initializer list.
+
+  // This block of fields will always be serialized.
+  InstanceType instance_type_;
+  int instance_size_;
+  uint32_t bit_field3_;
+  int unused_property_fields_;
+  bool is_abandoned_prototype_map_;
+  int in_object_properties_;
+
+  // These fields will only serialized if we are not concurrent inlining.
+  byte bit_field_;
+  byte bit_field2_;
+  bool can_be_deprecated_;
+  bool can_transition_;
+  int in_object_properties_start_in_words_;
+  int constructor_function_index_;
+  int next_free_property_index_;
+  bool supports_fast_array_iteration_;
+  bool supports_fast_array_resize_;
+
+  // These extra fields still have to be serialized (e.g prototype_) even with
+  // concurrent inling, since those classes have fields themselves which are not
+  // being directly read. This means that, for example, even though we can get
+  // the prototype itself with direct reads, some of its fields require
+  // serialization.
+  bool serialized_elements_kind_generalizations_ = false;
+  ZoneVector<ObjectData*> elements_kind_generalizations_;
+
+  bool serialized_own_descriptors_ = false;
+  ObjectData* instance_descriptors_ = nullptr;
+
+  bool serialized_constructor_ = false;
+  ObjectData* constructor_ = nullptr;
+
+  bool serialized_backpointer_ = false;
+  ObjectData* backpointer_ = nullptr;
+
+  bool serialized_prototype_ = false;
+  ObjectData* prototype_ = nullptr;
+
+  bool serialized_root_map_ = false;
+  ObjectData* root_map_ = nullptr;
+
+  bool serialized_for_element_load_ = false;
+
+  bool serialized_for_element_store_ = false;
+};
+
+AccessorInfoData::AccessorInfoData(JSHeapBroker* broker, ObjectData** storage,
+                                   Handle<AccessorInfo> object)
+    : HeapObjectData(broker, storage, object) {
+  DCHECK(!broker->is_concurrent_inlining());
+}
+
+AllocationSiteData::AllocationSiteData(JSHeapBroker* broker,
+                                       ObjectData** storage,
+                                       Handle<AllocationSite> object)
+    : HeapObjectData(broker, storage, object),
+      PointsToLiteral_(object->PointsToLiteral()),
+      GetAllocationType_(object->GetAllocationType()) {
+  if (PointsToLiteral_) {
+    IsFastLiteral_ = IsInlinableFastLiteral(
+        handle(object->boilerplate(kAcquireLoad), broker->isolate()));
+  } else {
+    GetElementsKind_ = object->GetElementsKind();
+    CanInlineCall_ = object->CanInlineCall();
+  }
+}
+
+void AllocationSiteData::SerializeBoilerplate(JSHeapBroker* broker) {
+  if (serialized_boilerplate_) return;
+  serialized_boilerplate_ = true;
+
+  TraceScope tracer(broker, this, "AllocationSiteData::SerializeBoilerplate");
+  Handle<AllocationSite> site = Handle<AllocationSite>::cast(object());
+
+  CHECK(IsFastLiteral_);
+  DCHECK_NULL(boilerplate_);
+  boilerplate_ = broker->GetOrCreateData(site->boilerplate(kAcquireLoad));
+  if (!boilerplate_->should_access_heap()) {
+    boilerplate_->AsJSObject()->SerializeAsBoilerplate(broker);
+  }
+
+  DCHECK_NULL(nested_site_);
+  nested_site_ = broker->GetOrCreateData(site->nested_site());
+  if (nested_site_->IsAllocationSite() && !nested_site_->should_access_heap()) {
+    nested_site_->AsAllocationSite()->SerializeBoilerplate(broker);
+  }
+}
+
+HeapObjectData::HeapObjectData(JSHeapBroker* broker, ObjectData** storage,
+                               Handle<HeapObject> object, ObjectDataKind kind)
+    : ObjectData(broker, storage, object, kind),
+      // We have to use a raw cast below instead of AsMap() because of
+      // recursion. AsMap() would call IsMap(), which accesses the
+      // instance_type_ member. In the case of constructing the MapData for the
+      // meta map (whose map is itself), this member has not yet been
+      // initialized.
+      map_(broker->GetOrCreateData(object->map(kAcquireLoad))) {
+  CHECK_IMPLIES(kind == kSerializedHeapObject,
+                broker->mode() == JSHeapBroker::kSerializing);
+  CHECK_IMPLIES(broker->mode() == JSHeapBroker::kSerialized,
+                kind == kBackgroundSerializedHeapObject);
+}
+
+base::Optional<bool> HeapObjectData::TryGetBooleanValue(
+    JSHeapBroker* broker) const {
+  // Keep in sync with Object::BooleanValue.
+  auto result = TryGetBooleanValueImpl(broker);
+  DCHECK_IMPLIES(broker->IsMainThread() && result.has_value(),
+                 result.value() == object()->BooleanValue(broker->isolate()));
+  return result;
+}
+
+base::Optional<bool> HeapObjectData::TryGetBooleanValueImpl(
+    JSHeapBroker* broker) const {
+  DisallowGarbageCollection no_gc;
+  Object o = *object();
+  Isolate* isolate = broker->isolate();
+  const InstanceType t = GetMapInstanceType();
+  if (o.IsTrue(isolate)) {
+    return true;
+  } else if (o.IsFalse(isolate)) {
+    return false;
+  } else if (o.IsNullOrUndefined(isolate)) {
+    return false;
+  } else if (MapRef{broker, map()}.is_undetectable()) {
+    return false;  // Undetectable object is false.
+  } else if (InstanceTypeChecker::IsString(t)) {
+    // TODO(jgruber): Implement in possible cases.
+    return {};
+  } else if (InstanceTypeChecker::IsHeapNumber(t)) {
+    return {};
+  } else if (InstanceTypeChecker::IsBigInt(t)) {
+    return {};
+  }
+  return true;
+}
+
+InstanceType HeapObjectData::GetMapInstanceType() const {
+  ObjectData* map_data = map();
+  if (map_data->should_access_heap()) {
+    return Handle<Map>::cast(map_data->object())->instance_type();
+  }
+  return map_data->AsMap()->instance_type();
+}
+
+namespace {
+
+bool IsReadOnlyLengthDescriptor(Isolate* isolate, Handle<Map> jsarray_map) {
+  DCHECK(!jsarray_map->is_dictionary_map());
+  DescriptorArray descriptors =
+      jsarray_map->instance_descriptors(isolate, kRelaxedLoad);
+  static_assert(
+      JSArray::kLengthOffset == JSObject::kHeaderSize,
+      "The length should be the first property on the descriptor array");
+  InternalIndex offset(0);
+  return descriptors.GetDetails(offset).IsReadOnly();
+}
+
+// Important: this predicate does not check Protectors::IsNoElementsIntact. The
+// compiler checks protectors through the compilation dependency mechanism; it
+// doesn't make sense to do that here as part of every MapData construction.
+// Callers *must* take care to take the correct dependency themselves.
+bool SupportsFastArrayIteration(JSHeapBroker* broker, Handle<Map> map) {
+  return map->instance_type() == JS_ARRAY_TYPE &&
+         IsFastElementsKind(map->elements_kind()) &&
+         map->prototype().IsJSArray() &&
+         broker->IsArrayOrObjectPrototype(broker->CanonicalPersistentHandle(
+             JSArray::cast(map->prototype())));
+}
+
+bool SupportsFastArrayResize(JSHeapBroker* broker, Handle<Map> map) {
+  return SupportsFastArrayIteration(broker, map) && map->is_extensible() &&
+         !map->is_dictionary_map() &&
+         !IsReadOnlyLengthDescriptor(broker->isolate(), map);
+}
+
+}  // namespace
+
+MapData::MapData(JSHeapBroker* broker, ObjectData** storage, Handle<Map> object,
+                 ObjectDataKind kind)
+    : HeapObjectData(broker, storage, object, kind),
+      elements_kind_generalizations_(broker->zone()) {
+  // This lock ensure that MapData can always be background-serialized, i.e.
+  // while the lock is held the Map object may not be modified (except in
+  // benign ways).
+  // TODO(jgruber): Consider removing this lock by being smrt.
+  JSHeapBroker::MapUpdaterGuardIfNeeded mumd_scope(
+      broker, broker->isolate()->map_updater_access());
+
+  // When background serializing the map, we can perform a lite serialization
+  // since the MapRef will read some of the Map's fields can be read directly.
+
+  // Even though MapRefs can read {instance_type} directly, other classes depend
+  // on {instance_type} being serialized.
+  instance_type_ = object->instance_type();
+  instance_size_ = object->instance_size();
+
+  // Both bit_field3 (and below bit_field) are special fields: Even though most
+  // of the individual bits inside of the bitfield could be read / written
+  // non-atomically, the bitfield itself has to use atomic relaxed accessors
+  // since some fields since can be modified in live objects.
+  // TODO(solanes, v8:7790): Assess if adding the exclusive lock in more places
+  // (e.g for set_has_non_instance_prototype) makes sense. Pros: these fields
+  // can use the non-atomic accessors. Cons: We would be acquiring an exclusive
+  // lock in more places.
+  bit_field3_ = object->relaxed_bit_field3();
+  unused_property_fields_ = object->UnusedPropertyFields();
+  is_abandoned_prototype_map_ = object->is_abandoned_prototype_map();
+  in_object_properties_ =
+      object->IsJSObjectMap() ? object->GetInObjectProperties() : 0;
+
+  // These fields are only needed to be serialized when not concurrent inlining
+  // and thus disabling direct reads.
+  if (!broker->is_concurrent_inlining()) {
+    bit_field_ = object->relaxed_bit_field();
+    bit_field2_ = object->bit_field2();
+    can_be_deprecated_ = object->NumberOfOwnDescriptors() > 0
+                             ? object->CanBeDeprecated()
+                             : false;
+    can_transition_ = object->CanTransition();
+    in_object_properties_start_in_words_ =
+        object->IsJSObjectMap() ? object->GetInObjectPropertiesStartInWords()
+                                : 0;
+    next_free_property_index_ = object->NextFreePropertyIndex();
+    constructor_function_index_ = object->IsPrimitiveMap()
+                                      ? object->GetConstructorFunctionIndex()
+                                      : Map::kNoConstructorFunctionIndex;
+    supports_fast_array_iteration_ = SupportsFastArrayIteration(broker, object);
+    supports_fast_array_resize_ = SupportsFastArrayResize(broker, object);
+  }
+}
+
+JSFunctionData::JSFunctionData(JSHeapBroker* broker, ObjectData** storage,
+                               Handle<JSFunction> object)
+    : JSObjectData(broker, storage, object),
+      has_feedback_vector_(object->has_feedback_vector()),
+      has_initial_map_(object->has_prototype_slot() &&
+                       object->has_initial_map()),
+      has_prototype_(object->has_prototype_slot() && object->has_prototype()),
+      PrototypeRequiresRuntimeLookup_(
+          object->PrototypeRequiresRuntimeLookup()) {}
+
+void JSFunctionData::Serialize(JSHeapBroker* broker) {
+  if (serialized_) return;
+  serialized_ = true;
+
+  TraceScope tracer(broker, this, "JSFunctionData::Serialize");
+  Handle<JSFunction> function = Handle<JSFunction>::cast(object());
+
+  DCHECK_NULL(context_);
+  DCHECK_NULL(native_context_);
+  DCHECK_NULL(initial_map_);
+  DCHECK_NULL(prototype_);
+  DCHECK_NULL(shared_);
+
+  context_ = broker->GetOrCreateData(function->context());
+  native_context_ = broker->GetOrCreateData(function->native_context());
+  shared_ = broker->GetOrCreateData(function->shared());
+
+  initial_map_ = has_initial_map()
+                     ? broker->GetOrCreateData(function->initial_map())
+                     : nullptr;
+  prototype_ = has_prototype() ? broker->GetOrCreateData(function->prototype())
+                               : nullptr;
+
+  if (initial_map_ != nullptr) {
+    initial_map_instance_size_with_min_slack_ =
+        function->ComputeInstanceSizeWithMinSlack(broker->isolate());
+  }
+  if (initial_map_ != nullptr && !initial_map_->should_access_heap()) {
+    if (initial_map_->AsMap()->instance_type() == JS_ARRAY_TYPE) {
+      initial_map_->AsMap()->SerializeElementsKindGeneralizations(broker);
+    }
+    initial_map_->AsMap()->SerializeConstructor(broker);
+    // TODO(neis): This is currently only needed for native_context's
+    // object_function, as used by GetObjectCreateMap. If no further use sites
+    // show up, we should move this into NativeContextData::Serialize.
+    initial_map_->AsMap()->SerializePrototype(broker);
+  }
+}
+
+void JSFunctionData::SerializeCodeAndFeedback(JSHeapBroker* broker) {
+  DCHECK(serialized_);
+  if (serialized_code_and_feedback_) return;
+  serialized_code_and_feedback_ = true;
+
+  TraceScope tracer(broker, this, "JSFunctionData::SerializeCodeAndFeedback");
+  Handle<JSFunction> function = Handle<JSFunction>::cast(object());
+
+  DCHECK_NULL(feedback_cell_);
+  DCHECK_NULL(feedback_vector_);
+  DCHECK_NULL(code_);
+  if (!broker->is_concurrent_inlining()) {
+    // This is conditionalized because Code objects are never serialized now.
+    // We only need to represent the code object in serialized data when
+    // we're unable to perform direct heap accesses.
+    code_ = broker->GetOrCreateData(function->code(kAcquireLoad));
+  }
+  feedback_cell_ = broker->GetOrCreateData(function->raw_feedback_cell());
+  feedback_vector_ = has_feedback_vector()
+                         ? broker->GetOrCreateData(function->feedback_vector())
+                         : nullptr;
+}
+
+void MapData::SerializeElementsKindGeneralizations(JSHeapBroker* broker) {
+  if (serialized_elements_kind_generalizations_) return;
+  serialized_elements_kind_generalizations_ = true;
+
+  TraceScope tracer(broker, this,
+                    "MapData::SerializeElementsKindGeneralizations");
+  DCHECK_EQ(instance_type(), JS_ARRAY_TYPE);
+  MapRef self(broker, this);
+  ElementsKind from_kind = self.elements_kind();
+  DCHECK(elements_kind_generalizations_.empty());
+  for (int i = FIRST_FAST_ELEMENTS_KIND; i <= LAST_FAST_ELEMENTS_KIND; i++) {
+    ElementsKind to_kind = static_cast<ElementsKind>(i);
+    if (IsMoreGeneralElementsKindTransition(from_kind, to_kind)) {
+      Handle<Map> target =
+          Map::AsElementsKind(broker->isolate(), self.object(), to_kind);
+      elements_kind_generalizations_.push_back(broker->GetOrCreateData(target));
+    }
+  }
+}
+
+class DescriptorArrayData : public HeapObjectData {
+ public:
+  DescriptorArrayData(JSHeapBroker* broker, ObjectData** storage,
+                      Handle<DescriptorArray> object)
+      : HeapObjectData(broker, storage, object), contents_(broker->zone()) {
+    DCHECK(!broker->is_concurrent_inlining());
+  }
+
+  ObjectData* FindFieldOwner(InternalIndex descriptor_index) const {
+    return contents_.at(descriptor_index.as_int()).field_owner;
+  }
+
+  PropertyDetails GetPropertyDetails(InternalIndex descriptor_index) const {
+    return contents_.at(descriptor_index.as_int()).details;
+  }
+
+  ObjectData* GetPropertyKey(InternalIndex descriptor_index) const {
+    return contents_.at(descriptor_index.as_int()).key;
+  }
+
+  FieldIndex GetFieldIndexFor(InternalIndex descriptor_index) const {
+    return contents_.at(descriptor_index.as_int()).field_index;
+  }
+
+  ObjectData* GetFieldType(InternalIndex descriptor_index) const {
+    return contents_.at(descriptor_index.as_int()).field_type;
+  }
+
+  ObjectData* GetStrongValue(InternalIndex descriptor_index) const {
+    return contents_.at(descriptor_index.as_int()).value;
+  }
+
+  bool serialized_descriptor(InternalIndex descriptor_index) const {
+    return contents_.find(descriptor_index.as_int()) != contents_.end();
+  }
+
+  void SerializeDescriptor(JSHeapBroker* broker, Handle<Map> map,
+                           InternalIndex descriptor_index);
+
+ private:
+  ZoneMap<int, PropertyDescriptor> contents_;
+};
+
+void DescriptorArrayData::SerializeDescriptor(JSHeapBroker* broker,
+                                              Handle<Map> map,
+                                              InternalIndex descriptor_index) {
+  CHECK_LT(descriptor_index.as_int(), map->NumberOfOwnDescriptors());
+  if (contents_.find(descriptor_index.as_int()) != contents_.end()) return;
+
+  Isolate* const isolate = broker->isolate();
+  auto descriptors = Handle<DescriptorArray>::cast(object());
+  CHECK_EQ(*descriptors, map->instance_descriptors(isolate));
+
+  PropertyDescriptor d;
+  d.key = broker->GetOrCreateData(descriptors->GetKey(descriptor_index));
+  MaybeObject value = descriptors->GetValue(descriptor_index);
+  HeapObject obj;
+  if (value.GetHeapObjectIfStrong(&obj)) {
+    d.value = broker->GetOrCreateData(obj);
+  }
+  d.details = descriptors->GetDetails(descriptor_index);
+  if (d.details.location() == kField) {
+    d.field_index = FieldIndex::ForDescriptor(*map, descriptor_index);
+    d.field_owner =
+        broker->GetOrCreateData(map->FindFieldOwner(isolate, descriptor_index));
+    d.field_type =
+        broker->GetOrCreateData(descriptors->GetFieldType(descriptor_index));
+  }
+  contents_[descriptor_index.as_int()] = d;
+
+  if (d.details.location() == kField && !d.field_owner->should_access_heap()) {
+    // Recurse on the owner map.
+    d.field_owner->AsMap()->SerializeOwnDescriptor(broker, descriptor_index);
+  }
+
+  TRACE(broker, "Copied descriptor " << descriptor_index.as_int() << " into "
+                                     << this << " (" << contents_.size()
+                                     << " total)");
+}
+
+class FeedbackCellData : public HeapObjectData {
+ public:
+  FeedbackCellData(JSHeapBroker* broker, ObjectData** storage,
+                   Handle<FeedbackCell> object);
+
+  ObjectData* value() const { return value_; }
+
+ private:
+  ObjectData* const value_;
+};
+
+FeedbackCellData::FeedbackCellData(JSHeapBroker* broker, ObjectData** storage,
+                                   Handle<FeedbackCell> object)
+    : HeapObjectData(broker, storage, object),
+      value_(object->value().IsFeedbackVector()
+                 ? broker->GetOrCreateData(object->value())
+                 : nullptr) {
+  DCHECK(!broker->is_concurrent_inlining());
+}
+
+class FeedbackVectorData : public HeapObjectData {
+ public:
+  FeedbackVectorData(JSHeapBroker* broker, ObjectData** storage,
+                     Handle<FeedbackVector> object);
+
+  double invocation_count() const { return invocation_count_; }
+
+  ObjectData* shared_function_info() {
+    CHECK(serialized_);
+    return shared_function_info_;
+  }
+
+  void Serialize(JSHeapBroker* broker);
+  bool serialized() const { return serialized_; }
+  ObjectData* GetClosureFeedbackCell(JSHeapBroker* broker, int index) const;
+
+ private:
+  double const invocation_count_;
+
+  bool serialized_ = false;
+  ObjectData* shared_function_info_;
+  ZoneVector<ObjectData*> closure_feedback_cell_array_;
+};
+
+FeedbackVectorData::FeedbackVectorData(JSHeapBroker* broker,
+                                       ObjectData** storage,
+                                       Handle<FeedbackVector> object)
+    : HeapObjectData(broker, storage, object),
+      invocation_count_(object->invocation_count()),
+      closure_feedback_cell_array_(broker->zone()) {
+  DCHECK(!broker->is_concurrent_inlining());
+}
+
+ObjectData* FeedbackVectorData::GetClosureFeedbackCell(JSHeapBroker* broker,
+                                                       int index) const {
+  CHECK_GE(index, 0);
+
+  size_t cell_array_size = closure_feedback_cell_array_.size();
+  if (!serialized_) {
+    DCHECK_EQ(cell_array_size, 0);
+    TRACE_BROKER_MISSING(broker,
+                         " closure feedback cell array for vector " << this);
+    return nullptr;
+  }
+  CHECK_LT(index, cell_array_size);
+  return closure_feedback_cell_array_[index];
+}
+
+void FeedbackVectorData::Serialize(JSHeapBroker* broker) {
+  if (serialized_) return;
+  serialized_ = true;
+
+  TraceScope tracer(broker, this, "FeedbackVectorData::Serialize");
+  Handle<FeedbackVector> vector = Handle<FeedbackVector>::cast(object());
+  Handle<SharedFunctionInfo> sfi(vector->shared_function_info(),
+                                 broker->isolate());
+  shared_function_info_ = broker->GetOrCreateData(sfi);
+  DCHECK(closure_feedback_cell_array_.empty());
+  int length = vector->closure_feedback_cell_array().length();
+  closure_feedback_cell_array_.reserve(length);
+  for (int i = 0; i < length; ++i) {
+    Handle<FeedbackCell> cell = vector->GetClosureFeedbackCell(i);
+    ObjectData* cell_data = broker->GetOrCreateData(cell);
+    closure_feedback_cell_array_.push_back(cell_data);
+  }
+  TRACE(broker, "Copied " << length << " feedback cells");
+}
+
+class FixedArrayBaseData : public HeapObjectData {
+ public:
+  FixedArrayBaseData(JSHeapBroker* broker, ObjectData** storage,
+                     Handle<FixedArrayBase> object, ObjectDataKind kind)
+      : HeapObjectData(broker, storage, object, kind),
+        length_(object->length()) {}
+
+  int length() const { return length_; }
+
+ private:
+  int const length_;
+};
+
+class FixedArrayData : public FixedArrayBaseData {
+ public:
+  FixedArrayData(JSHeapBroker* broker, ObjectData** storage,
+                 Handle<FixedArray> object, ObjectDataKind kind)
+      : FixedArrayBaseData(broker, storage, object, kind) {}
+};
+
+class ObjectBoilerplateDescriptionData : public FixedArrayData {
+ public:
+  ObjectBoilerplateDescriptionData(
+      JSHeapBroker* broker, ObjectData** storage,
+      Handle<ObjectBoilerplateDescription> object,
+      ObjectDataKind kind = ObjectDataKind::kSerializedHeapObject)
+      : FixedArrayData(broker, storage, object, kind), size_(object->size()) {
+    DCHECK(!broker->is_concurrent_inlining());
+  }
+
+  int size() const { return size_; }
+
+ private:
+  int const size_;
+};
+
+// Only used in JSNativeContextSpecialization.
+class ScriptContextTableData : public FixedArrayData {
+ public:
+  ScriptContextTableData(JSHeapBroker* broker, ObjectData** storage,
+                         Handle<ScriptContextTable> object, ObjectDataKind kind)
+      : FixedArrayData(broker, storage, object, kind) {}
+};
+
+JSDataViewData::JSDataViewData(JSHeapBroker* broker, ObjectData** storage,
+                               Handle<JSDataView> object)
+    : JSObjectData(broker, storage, object),
+      byte_length_(object->byte_length()) {}
+
+JSBoundFunctionData::JSBoundFunctionData(JSHeapBroker* broker,
+                                         ObjectData** storage,
+                                         Handle<JSBoundFunction> object)
+    : JSObjectData(broker, storage, object) {}
+
+bool JSBoundFunctionData::Serialize(JSHeapBroker* broker) {
+  if (serialized_) return true;
+  if (broker->StackHasOverflowed()) return false;
+
+  TraceScope tracer(broker, this, "JSBoundFunctionData::Serialize");
+  Handle<JSBoundFunction> function = Handle<JSBoundFunction>::cast(object());
+
+  // We don't immediately set {serialized_} in order to correctly handle the
+  // case where a recursive call to this method reaches the stack limit.
+
+  DCHECK_NULL(bound_target_function_);
+  bound_target_function_ =
+      broker->GetOrCreateData(function->bound_target_function());
+  bool serialized_nested = true;
+  if (!bound_target_function_->should_access_heap()) {
+    if (bound_target_function_->IsJSBoundFunction()) {
+      serialized_nested =
+          bound_target_function_->AsJSBoundFunction()->Serialize(broker);
+    } else if (bound_target_function_->IsJSFunction()) {
+      bound_target_function_->AsJSFunction()->Serialize(broker);
+    }
+  }
+  if (!serialized_nested) {
+    // We couldn't serialize all nested bound functions due to stack
+    // overflow. Give up.
+    DCHECK(!serialized_);
+    bound_target_function_ = nullptr;  // Reset to sync with serialized_.
+    return false;
+  }
+
+  serialized_ = true;
+
+  DCHECK_NULL(bound_arguments_);
+  bound_arguments_ = broker->GetOrCreateData(function->bound_arguments());
+
+  DCHECK_NULL(bound_this_);
+  bound_this_ = broker->GetOrCreateData(function->bound_this());
+
+  return true;
+}
+
+JSObjectData::JSObjectData(JSHeapBroker* broker, ObjectData** storage,
+                           Handle<JSObject> object)
+    : JSReceiverData(broker, storage, object,
+                     ObjectDataKind::kSerializedHeapObject),
+      inobject_fields_(broker->zone()),
+      own_constant_elements_(broker->zone()),
+      own_properties_(broker->zone()) {}
+
+class FixedDoubleArrayData : public FixedArrayBaseData {
+ public:
+  FixedDoubleArrayData(
+      JSHeapBroker* broker, ObjectData** storage,
+      Handle<FixedDoubleArray> object,
+      ObjectDataKind kind = ObjectDataKind::kNeverSerializedHeapObject)
+      : FixedArrayBaseData(broker, storage, object, kind) {
+    DCHECK(!broker->is_concurrent_inlining());
+  }
+};
+
+class BytecodeArrayData : public FixedArrayBaseData {
+ public:
+  int register_count() const { return register_count_; }
+  int parameter_count() const { return parameter_count_; }
+  interpreter::Register incoming_new_target_or_generator_register() const {
+    return incoming_new_target_or_generator_register_;
+  }
+
+  BytecodeArrayData(JSHeapBroker* broker, ObjectData** storage,
+                    Handle<BytecodeArray> object)
+      : FixedArrayBaseData(broker, storage, object,
+                           ObjectDataKind::kNeverSerializedHeapObject),
+        register_count_(object->register_count()),
+        parameter_count_(object->parameter_count()),
+        incoming_new_target_or_generator_register_(
+            object->incoming_new_target_or_generator_register()) {}
+
+ private:
+  int const register_count_;
+  int const parameter_count_;
+  interpreter::Register const incoming_new_target_or_generator_register_;
+};
+
+class JSArrayData : public JSObjectData {
+ public:
+  JSArrayData(JSHeapBroker* broker, ObjectData** storage,
+              Handle<JSArray> object);
+
+  void Serialize(JSHeapBroker* broker);
+  ObjectData* length() const {
+    CHECK(serialized_);
+    return length_;
+  }
+
+  ObjectData* GetOwnElement(
+      JSHeapBroker* broker, uint32_t index,
+      SerializationPolicy policy = SerializationPolicy::kAssumeSerialized);
+
+ private:
+  bool serialized_ = false;
+  ObjectData* length_ = nullptr;
+
+  // Elements (indexed properties) that either
+  // (1) are known to exist directly on the object, or
+  // (2) are known not to (possibly they don't exist at all).
+  // In case (2), the second pair component is nullptr.
+  ZoneVector<std::pair<uint32_t, ObjectData*>> own_elements_;
+};
+
+JSArrayData::JSArrayData(JSHeapBroker* broker, ObjectData** storage,
+                         Handle<JSArray> object)
+    : JSObjectData(broker, storage, object), own_elements_(broker->zone()) {}
+
+void JSArrayData::Serialize(JSHeapBroker* broker) {
+  CHECK(!broker->is_concurrent_inlining());
+
+  if (serialized_) return;
+  serialized_ = true;
+
+  TraceScope tracer(broker, this, "JSArrayData::Serialize");
+  Handle<JSArray> jsarray = Handle<JSArray>::cast(object());
+
+  DCHECK_NULL(length_);
+  length_ = broker->GetOrCreateData(jsarray->length());
+}
+
+ObjectData* JSArrayData::GetOwnElement(JSHeapBroker* broker, uint32_t index,
+                                       SerializationPolicy policy) {
+  for (auto const& p : own_elements_) {
+    if (p.first == index) return p.second;
+  }
+
+  if (policy == SerializationPolicy::kAssumeSerialized) {
+    TRACE_MISSING(broker, "knowledge about index " << index << " on " << this);
+    return nullptr;
+  }
+
+  base::Optional<ObjectRef> element =
+      GetOwnElementFromHeap(broker, object(), index, false);
+  ObjectData* result = element.has_value() ? element->data() : nullptr;
+  own_elements_.push_back({index, result});
+  return result;
+}
+
+class ScopeInfoData : public HeapObjectData {
+ public:
+  ScopeInfoData(JSHeapBroker* broker, ObjectData** storage,
+                Handle<ScopeInfo> object);
+
+  int ContextLength() const { return context_length_; }
+  bool HasContextExtensionSlot() const { return has_context_extension_slot_; }
+  bool HasOuterScopeInfo() const { return has_outer_scope_info_; }
+
+  ObjectData* OuterScopeInfo() const { return outer_scope_info_; }
+  void SerializeScopeInfoChain(JSHeapBroker* broker);
+
+ private:
+  int const context_length_;
+  bool const has_context_extension_slot_;
+  bool const has_outer_scope_info_;
+
+  // Only serialized via SerializeScopeInfoChain.
+  ObjectData* outer_scope_info_;
+};
+
+ScopeInfoData::ScopeInfoData(JSHeapBroker* broker, ObjectData** storage,
+                             Handle<ScopeInfo> object)
+    : HeapObjectData(broker, storage, object),
+      context_length_(object->ContextLength()),
+      has_context_extension_slot_(object->HasContextExtensionSlot()),
+      has_outer_scope_info_(object->HasOuterScopeInfo()),
+      outer_scope_info_(nullptr) {
+  DCHECK(!broker->is_concurrent_inlining());
+}
+
+void ScopeInfoData::SerializeScopeInfoChain(JSHeapBroker* broker) {
+  if (outer_scope_info_) return;
+  if (!has_outer_scope_info_) return;
+  outer_scope_info_ = broker->GetOrCreateData(
+      Handle<ScopeInfo>::cast(object())->OuterScopeInfo());
+  if (!outer_scope_info_->should_access_heap()) {
+    outer_scope_info_->AsScopeInfo()->SerializeScopeInfoChain(broker);
+  }
+}
+
+class SharedFunctionInfoData : public HeapObjectData {
+ public:
+  SharedFunctionInfoData(JSHeapBroker* broker, ObjectData** storage,
+                         Handle<SharedFunctionInfo> object);
+
+  int builtin_id() const { return builtin_id_; }
+  int context_header_size() const { return context_header_size_; }
+  ObjectData* GetBytecodeArray() const { return GetBytecodeArray_; }
+  SharedFunctionInfo::Inlineability GetInlineability() const {
+    return inlineability_;
+  }
+  void SerializeFunctionTemplateInfo(JSHeapBroker* broker);
+  ObjectData* scope_info() const { return scope_info_; }
+  void SerializeScopeInfoChain(JSHeapBroker* broker);
+  ObjectData* function_template_info() const { return function_template_info_; }
+  ObjectData* GetTemplateObject(FeedbackSlot slot) const {
+    auto lookup_it = template_objects_.find(slot.ToInt());
+    if (lookup_it != template_objects_.cend()) {
+      return lookup_it->second;
+    }
+    return nullptr;
+  }
+  void SetTemplateObject(FeedbackSlot slot, ObjectData* object) {
+    CHECK(
+        template_objects_.insert(std::make_pair(slot.ToInt(), object)).second);
+  }
+
+#define DECL_ACCESSOR(type, name) \
+  type name() const { return name##_; }
+  BROKER_SFI_FIELDS(DECL_ACCESSOR)
+#undef DECL_ACCESSOR
+
+ private:
+  int const builtin_id_;
+  int const context_header_size_;
+  ObjectData* const GetBytecodeArray_;
+#define DECL_MEMBER(type, name) type const name##_;
+  BROKER_SFI_FIELDS(DECL_MEMBER)
+#undef DECL_MEMBER
+  SharedFunctionInfo::Inlineability const inlineability_;
+  ObjectData* function_template_info_;
+  ZoneMap<int, ObjectData*> template_objects_;
+  ObjectData* scope_info_;
+};
+
+SharedFunctionInfoData::SharedFunctionInfoData(
+    JSHeapBroker* broker, ObjectData** storage,
+    Handle<SharedFunctionInfo> object)
+    : HeapObjectData(broker, storage, object),
+      builtin_id_(object->HasBuiltinId() ? object->builtin_id()
+                                         : Builtins::kNoBuiltinId),
+      context_header_size_(object->scope_info().ContextHeaderLength()),
+      GetBytecodeArray_(object->HasBytecodeArray()
+                            ? broker->GetOrCreateData(
+                                  object->GetBytecodeArray(broker->isolate()))
+                            : nullptr)
+#define INIT_MEMBER(type, name) , name##_(object->name())
+          BROKER_SFI_FIELDS(INIT_MEMBER)
+#undef INIT_MEMBER
+      ,
+      inlineability_(object->GetInlineability(broker->isolate())),
+      function_template_info_(nullptr),
+      template_objects_(broker->zone()),
+      scope_info_(nullptr) {
+  DCHECK_EQ(HasBuiltinId_, builtin_id_ != Builtins::kNoBuiltinId);
+  DCHECK_EQ(HasBytecodeArray_, GetBytecodeArray_ != nullptr);
+}
+
+void SharedFunctionInfoData::SerializeFunctionTemplateInfo(
+    JSHeapBroker* broker) {
+  if (function_template_info_) return;
+  function_template_info_ = broker->GetOrCreateData(
+      Handle<SharedFunctionInfo>::cast(object())->function_data(kAcquireLoad));
+}
+
+void SharedFunctionInfoData::SerializeScopeInfoChain(JSHeapBroker* broker) {
+  if (scope_info_) return;
+  scope_info_ = broker->GetOrCreateData(
+      Handle<SharedFunctionInfo>::cast(object())->scope_info());
+  if (!scope_info_->should_access_heap()) {
+    scope_info_->AsScopeInfo()->SerializeScopeInfoChain(broker);
+  }
+}
+
+class SourceTextModuleData : public HeapObjectData {
+ public:
+  SourceTextModuleData(JSHeapBroker* broker, ObjectData** storage,
+                       Handle<SourceTextModule> object);
+  void Serialize(JSHeapBroker* broker);
+
+  ObjectData* GetCell(JSHeapBroker* broker, int cell_index) const;
+  ObjectData* GetImportMeta(JSHeapBroker* broker) const;
+
+ private:
+  bool serialized_ = false;
+  ZoneVector<ObjectData*> imports_;
+  ZoneVector<ObjectData*> exports_;
+  ObjectData* import_meta_;
+};
+
+SourceTextModuleData::SourceTextModuleData(JSHeapBroker* broker,
+                                           ObjectData** storage,
+                                           Handle<SourceTextModule> object)
+    : HeapObjectData(broker, storage, object),
+      imports_(broker->zone()),
+      exports_(broker->zone()),
+      import_meta_(nullptr) {}
+
+ObjectData* SourceTextModuleData::GetCell(JSHeapBroker* broker,
+                                          int cell_index) const {
+  if (!serialized_) {
+    DCHECK(imports_.empty());
+    TRACE_BROKER_MISSING(broker,
+                         "module cell " << cell_index << " on " << this);
+    return nullptr;
+  }
+  ObjectData* cell;
+  switch (SourceTextModuleDescriptor::GetCellIndexKind(cell_index)) {
+    case SourceTextModuleDescriptor::kImport:
+      cell = imports_.at(SourceTextModule::ImportIndex(cell_index));
+      break;
+    case SourceTextModuleDescriptor::kExport:
+      cell = exports_.at(SourceTextModule::ExportIndex(cell_index));
+      break;
+    case SourceTextModuleDescriptor::kInvalid:
+      UNREACHABLE();
+  }
+  CHECK_NOT_NULL(cell);
+  return cell;
+}
+
+ObjectData* SourceTextModuleData::GetImportMeta(JSHeapBroker* broker) const {
+  CHECK(serialized_);
+  return import_meta_;
+}
+
+void SourceTextModuleData::Serialize(JSHeapBroker* broker) {
+  if (serialized_) return;
+  serialized_ = true;
+
+  TraceScope tracer(broker, this, "SourceTextModuleData::Serialize");
+  Handle<SourceTextModule> module = Handle<SourceTextModule>::cast(object());
+
+  // TODO(neis): We could be smarter and only serialize the cells we care about.
+  // TODO(neis): Define a helper for serializing a FixedArray into a ZoneVector.
+
+  DCHECK(imports_.empty());
+  Handle<FixedArray> imports(module->regular_imports(), broker->isolate());
+  int const imports_length = imports->length();
+  imports_.reserve(imports_length);
+  for (int i = 0; i < imports_length; ++i) {
+    imports_.push_back(broker->GetOrCreateData(imports->get(i)));
+  }
+  TRACE(broker, "Copied " << imports_.size() << " imports");
+
+  DCHECK(exports_.empty());
+  Handle<FixedArray> exports(module->regular_exports(), broker->isolate());
+  int const exports_length = exports->length();
+  exports_.reserve(exports_length);
+  for (int i = 0; i < exports_length; ++i) {
+    exports_.push_back(broker->GetOrCreateData(exports->get(i)));
+  }
+  TRACE(broker, "Copied " << exports_.size() << " exports");
+
+  DCHECK_NULL(import_meta_);
+  import_meta_ = broker->GetOrCreateData(module->import_meta(kAcquireLoad));
+  TRACE(broker, "Copied import_meta");
+}
+
+class CellData : public HeapObjectData {
+ public:
+  CellData(JSHeapBroker* broker, ObjectData** storage, Handle<Cell> object)
+      : HeapObjectData(broker, storage, object) {
+    DCHECK(!broker->is_concurrent_inlining());
+  }
+};
+
+class JSGlobalObjectData : public JSObjectData {
+ public:
+  JSGlobalObjectData(JSHeapBroker* broker, ObjectData** storage,
+                     Handle<JSGlobalObject> object);
+  bool IsDetached() const { return is_detached_; }
+
+  ObjectData* GetPropertyCell(
+      JSHeapBroker* broker, ObjectData* name,
+      SerializationPolicy policy = SerializationPolicy::kAssumeSerialized);
+
+ private:
+  bool const is_detached_;
+
+  // Properties that either
+  // (1) are known to exist as property cells on the global object, or
+  // (2) are known not to (possibly they don't exist at all).
+  // In case (2), the second pair component is nullptr.
+  ZoneVector<std::pair<ObjectData*, ObjectData*>> properties_;
+};
+
+JSGlobalObjectData::JSGlobalObjectData(JSHeapBroker* broker,
+                                       ObjectData** storage,
+                                       Handle<JSGlobalObject> object)
+    : JSObjectData(broker, storage, object),
+      is_detached_(object->IsDetached()),
+      properties_(broker->zone()) {}
+
+class JSGlobalProxyData : public JSObjectData {
+ public:
+  JSGlobalProxyData(JSHeapBroker* broker, ObjectData** storage,
+                    Handle<JSGlobalProxy> object);
+};
+
+JSGlobalProxyData::JSGlobalProxyData(JSHeapBroker* broker, ObjectData** storage,
+                                     Handle<JSGlobalProxy> object)
+    : JSObjectData(broker, storage, object) {}
+
+namespace {
+
+base::Optional<PropertyCellRef> GetPropertyCellFromHeap(JSHeapBroker* broker,
+                                                        Handle<Name> name) {
+  LookupIterator it(
+      broker->isolate(),
+      handle(broker->target_native_context().object()->global_object(),
+             broker->isolate()),
+      name, LookupIterator::OWN);
+  it.TryLookupCachedProperty();
+  if (it.state() == LookupIterator::DATA &&
+      it.GetHolder<JSObject>()->IsJSGlobalObject()) {
+    return TryMakeRef(broker, it.GetPropertyCell());
+  }
+  return base::nullopt;
+}
+
+}  // namespace
+
+ObjectData* JSGlobalObjectData::GetPropertyCell(JSHeapBroker* broker,
+                                                ObjectData* name,
+                                                SerializationPolicy policy) {
+  CHECK_NOT_NULL(name);
+  for (auto const& p : properties_) {
+    if (p.first == name) return p.second;
+  }
+
+  if (policy == SerializationPolicy::kAssumeSerialized) {
+    TRACE_MISSING(broker, "knowledge about global property " << name);
+    return nullptr;
+  }
+
+  ObjectData* result = nullptr;
+  base::Optional<PropertyCellRef> cell =
+      GetPropertyCellFromHeap(broker, Handle<Name>::cast(name->object()));
+  if (cell.has_value()) {
+    result = cell->data();
+    if (!result->should_access_heap()) {
+      result->AsPropertyCell()->Serialize(broker);
+    }
+  }
+  properties_.push_back({name, result});
+  return result;
+}
+
+class TemplateObjectDescriptionData : public HeapObjectData {
+ public:
+  TemplateObjectDescriptionData(JSHeapBroker* broker, ObjectData** storage,
+                                Handle<TemplateObjectDescription> object)
+      : HeapObjectData(broker, storage, object) {
+    DCHECK(!broker->is_concurrent_inlining());
+  }
+};
+
+class CodeData : public HeapObjectData {
+ public:
+  CodeData(JSHeapBroker* broker, ObjectData** storage, Handle<Code> object)
+      : HeapObjectData(broker, storage, object),
+        inlined_bytecode_size_(object->inlined_bytecode_size() > 0 &&
+                                       !object->marked_for_deoptimization()
+                                   ? object->inlined_bytecode_size()
+                                   : 0) {
+    DCHECK(!broker->is_concurrent_inlining());
+  }
+
+  unsigned inlined_bytecode_size() const { return inlined_bytecode_size_; }
+
+ private:
+  unsigned const inlined_bytecode_size_;
+};
+
+#define DEFINE_IS(Name, ...)                                            \
+  bool ObjectData::Is##Name() const {                                   \
+    if (should_access_heap()) {                                         \
+      return object()->Is##Name();                                      \
+    }                                                                   \
+    if (is_smi()) return false;                                         \
+    InstanceType instance_type =                                        \
+        static_cast<const HeapObjectData*>(this)->GetMapInstanceType(); \
+    return InstanceTypeChecker::Is##Name(instance_type);                \
+  }
+HEAP_BROKER_OBJECT_LIST(DEFINE_IS)
+#undef DEFINE_IS
+
+#define DEFINE_AS(Name, Kind)                                      \
+  Name##Data* ObjectData::As##Name() {                             \
+    CHECK(Is##Name());                                             \
+    CHECK(kind_ == kSerializedHeapObject ||                        \
+          kind_ == kBackgroundSerializedHeapObject);               \
+    return static_cast<Name##Data*>(this);                         \
+  }
+HEAP_BROKER_OBJECT_LIST(DEFINE_AS)
+#undef DEFINE_AS
+
+ObjectData* JSObjectData::GetInobjectField(int property_index) const {
+  CHECK_LT(static_cast<size_t>(property_index), inobject_fields_.size());
+  return inobject_fields_[property_index];
+}
+
+bool JSObjectData::cow_or_empty_elements_tenured() const {
+  return cow_or_empty_elements_tenured_;
+}
+
+ObjectData* JSObjectData::elements() const {
+  CHECK(serialized_elements_);
+  return elements_;
+}
+
+void JSObjectData::SerializeAsBoilerplate(JSHeapBroker* broker) {
+  SerializeRecursiveAsBoilerplate(broker, kMaxFastLiteralDepth);
+}
+
+void JSObjectData::SerializeElements(JSHeapBroker* broker) {
+  if (serialized_elements_) return;
+  serialized_elements_ = true;
+
+  TraceScope tracer(broker, this, "JSObjectData::SerializeElements");
+  Handle<JSObject> boilerplate = Handle<JSObject>::cast(object());
+  Handle<FixedArrayBase> elements_object(boilerplate->elements(),
+                                         broker->isolate());
+  DCHECK_NULL(elements_);
+  elements_ = broker->GetOrCreateData(elements_object);
+  DCHECK(elements_->IsFixedArrayBase());
+}
+
+void MapData::SerializeConstructor(JSHeapBroker* broker) {
+  if (serialized_constructor_) return;
+  serialized_constructor_ = true;
+
+  TraceScope tracer(broker, this, "MapData::SerializeConstructor");
+  Handle<Map> map = Handle<Map>::cast(object());
+  DCHECK(!map->IsContextMap());
+  DCHECK_NULL(constructor_);
+  constructor_ = broker->GetOrCreateData(map->GetConstructor());
+}
+
+void MapData::SerializeBackPointer(JSHeapBroker* broker) {
+  if (serialized_backpointer_) return;
+  serialized_backpointer_ = true;
+
+  TraceScope tracer(broker, this, "MapData::SerializeBackPointer");
+  Handle<Map> map = Handle<Map>::cast(object());
+  DCHECK_NULL(backpointer_);
+  DCHECK(!map->IsContextMap());
+  backpointer_ = broker->GetOrCreateData(map->GetBackPointer());
+}
+
+bool MapData::TrySerializePrototype(JSHeapBroker* broker) {
+  if (serialized_prototype_) return true;
+
+  TraceScope tracer(broker, this, "MapData::SerializePrototype");
+  Handle<Map> map = Handle<Map>::cast(object());
+  DCHECK_NULL(prototype_);
+  prototype_ = broker->TryGetOrCreateData(map->prototype());
+  if (prototype_ == nullptr) return false;
+  serialized_prototype_ = true;
+  return true;
+}
+
+void MapData::SerializeOwnDescriptors(JSHeapBroker* broker) {
+  if (serialized_own_descriptors_) return;
+  serialized_own_descriptors_ = true;
+
+  TraceScope tracer(broker, this, "MapData::SerializeOwnDescriptors");
+  Handle<Map> map = Handle<Map>::cast(object());
+
+  for (InternalIndex i : map->IterateOwnDescriptors()) {
+    SerializeOwnDescriptor(broker, i);
+  }
+}
+
+bool MapData::TrySerializeOwnDescriptor(JSHeapBroker* broker,
+                                        InternalIndex descriptor_index) {
+  TraceScope tracer(broker, this, "MapData::SerializeOwnDescriptor");
+  Handle<Map> map = Handle<Map>::cast(object());
+  Isolate* isolate = broker->isolate();
+
+  if (instance_descriptors_ == nullptr) {
+    instance_descriptors_ =
+        broker->TryGetOrCreateData(map->instance_descriptors(kAcquireLoad));
+    if (instance_descriptors_ == nullptr) return false;
+  }
+
+  if (instance_descriptors()->should_access_heap()) {
+    // When accessing the fields concurrently, we still have to recurse on the
+    // owner map if it is different than the current map. This is because
+    // {instance_descriptors_} gets set on SerializeOwnDescriptor and otherwise
+    // we risk the field owner having a null {instance_descriptors_}.
+    Handle<DescriptorArray> descriptors = broker->CanonicalPersistentHandle(
+        map->instance_descriptors(kAcquireLoad));
+    if (descriptors->GetDetails(descriptor_index).location() == kField) {
+      Handle<Map> owner = broker->CanonicalPersistentHandle(
+          map->FindFieldOwner(isolate, descriptor_index));
+      if (!owner.equals(map)) {
+        ObjectData* data = broker->TryGetOrCreateData(owner);
+        if (data == nullptr) return false;
+        data->AsMap()->SerializeOwnDescriptor(broker, descriptor_index);
+      }
+    }
+  } else {
+    DescriptorArrayData* descriptors =
+        instance_descriptors()->AsDescriptorArray();
+    descriptors->SerializeDescriptor(broker, map, descriptor_index);
+  }
+
+  return true;
+}
+
+void MapData::SerializeRootMap(JSHeapBroker* broker) {
+  if (serialized_root_map_) return;
+  serialized_root_map_ = true;
+
+  TraceScope tracer(broker, this, "MapData::SerializeRootMap");
+  Handle<Map> map = Handle<Map>::cast(object());
+  DCHECK_NULL(root_map_);
+  root_map_ = broker->GetOrCreateData(map->FindRootMap(broker->isolate()));
+}
+
+ObjectData* MapData::FindRootMap() const { return root_map_; }
+
+void JSObjectData::SerializeRecursiveAsBoilerplate(JSHeapBroker* broker,
+                                                   int depth) {
+  if (serialized_as_boilerplate_) return;
+  serialized_as_boilerplate_ = true;
+
+  TraceScope tracer(broker, this,
+                    "JSObjectData::SerializeRecursiveAsBoilerplate");
+  Handle<JSObject> boilerplate = Handle<JSObject>::cast(object());
+
+  // We only serialize boilerplates that pass the IsInlinableFastLiteral
+  // check, so we only do a check on the depth here.
+  CHECK_GT(depth, 0);
+
+  // Serialize the elements.
+  Isolate* const isolate = broker->isolate();
+  Handle<FixedArrayBase> elements_object(boilerplate->elements(), isolate);
+
+  // Boilerplates need special serialization - we need to make sure COW arrays
+  // are tenured. Boilerplate objects should only be reachable from their
+  // allocation site, so it is safe to assume that the elements have not been
+  // serialized yet.
+
+  bool const empty_or_cow =
+      elements_object->length() == 0 ||
+      elements_object->map() == ReadOnlyRoots(isolate).fixed_cow_array_map();
+  if (empty_or_cow) {
+    // We need to make sure copy-on-write elements are tenured.
+    if (ObjectInYoungGeneration(*elements_object)) {
+      elements_object = isolate->factory()->CopyAndTenureFixedCOWArray(
+          Handle<FixedArray>::cast(elements_object));
+      boilerplate->set_elements(*elements_object);
+    }
+    cow_or_empty_elements_tenured_ = true;
+  }
+
+  DCHECK_NULL(elements_);
+  DCHECK(!serialized_elements_);
+  serialized_elements_ = true;
+  elements_ = broker->GetOrCreateData(elements_object);
+  DCHECK(elements_->IsFixedArrayBase());
+
+  if (empty_or_cow || elements_->should_access_heap()) {
+    // No need to do anything here. Empty or copy-on-write elements
+    // do not need to be serialized because we only need to store the elements
+    // reference to the allocated object.
+  } else if (boilerplate->HasSmiOrObjectElements()) {
+    Handle<FixedArray> fast_elements =
+        Handle<FixedArray>::cast(elements_object);
+    int length = elements_object->length();
+    for (int i = 0; i < length; i++) {
+      Handle<Object> value(fast_elements->get(i), isolate);
+      if (value->IsJSObject()) {
+        ObjectData* value_data = broker->GetOrCreateData(value);
+        if (!value_data->should_access_heap()) {
+          value_data->AsJSObject()->SerializeRecursiveAsBoilerplate(broker,
+                                                                    depth - 1);
+        }
+      }
+    }
+  } else {
+    CHECK(boilerplate->HasDoubleElements());
+    CHECK_LE(elements_object->Size(), kMaxRegularHeapObjectSize);
+  }
+
+  // TODO(turbofan): Do we want to support out-of-object properties?
+  CHECK(boilerplate->HasFastProperties() &&
+        boilerplate->property_array().length() == 0);
+  CHECK_EQ(inobject_fields_.size(), 0u);
+
+  // Check the in-object properties.
+  Handle<DescriptorArray> descriptors(
+      boilerplate->map().instance_descriptors(isolate), isolate);
+  for (InternalIndex i : boilerplate->map().IterateOwnDescriptors()) {
+    PropertyDetails details = descriptors->GetDetails(i);
+    if (details.location() != kField) continue;
+    DCHECK_EQ(kData, details.kind());
+
+    FieldIndex field_index = FieldIndex::ForDescriptor(boilerplate->map(), i);
+    // Make sure {field_index} agrees with {inobject_properties} on the index of
+    // this field.
+    DCHECK_EQ(field_index.property_index(),
+              static_cast<int>(inobject_fields_.size()));
+    Handle<Object> value(boilerplate->RawFastPropertyAt(field_index), isolate);
+    // In case of double fields we use a sentinel NaN value to mark
+    // uninitialized fields. A boilerplate value with such a field may migrate
+    // from its double to a tagged representation. The sentinel value carries
+    // no special meaning when it occurs in a heap number, so we would like to
+    // recover the uninitialized value. We check for the sentinel here,
+    // specifically, since migrations might have been triggered as part of
+    // boilerplate serialization.
+    if (!details.representation().IsDouble() && value->IsHeapNumber() &&
+        HeapNumber::cast(*value).value_as_bits() == kHoleNanInt64) {
+      value = isolate->factory()->uninitialized_value();
+    }
+    ObjectData* value_data = broker->GetOrCreateData(value);
+    if (value_data->IsJSObject() && !value_data->should_access_heap()) {
+      value_data->AsJSObject()->SerializeRecursiveAsBoilerplate(broker,
+                                                                depth - 1);
+    }
+    inobject_fields_.push_back(value_data);
+  }
+  TRACE(broker, "Copied " << inobject_fields_.size() << " in-object fields");
+
+  if (!map()->should_access_heap()) {
+    map()->AsMap()->SerializeOwnDescriptors(broker);
+  }
+
+  if (IsJSArray() && !broker->is_concurrent_inlining()) {
+    AsJSArray()->Serialize(broker);
+  }
+}
+
+void RegExpBoilerplateDescriptionData::Serialize(JSHeapBroker* broker) {
+  if (serialized_) return;  // Only serialize once.
+  serialized_ = true;
+
+  TraceScope tracer(broker, this,
+                    "RegExpBoilerplateDescriptionData::Serialize");
+  auto boilerplate = Handle<RegExpBoilerplateDescription>::cast(object());
+
+  data_ = broker->GetOrCreateData(boilerplate->data());
+  source_ = broker->GetOrCreateData(boilerplate->source());
+  flags_ = boilerplate->flags();
+}
+
+#ifdef DEBUG
+bool ObjectRef::IsNeverSerializedHeapObject() const {
+  return data_->kind() == ObjectDataKind::kNeverSerializedHeapObject;
+}
+#endif  // DEBUG
+
+bool ObjectRef::equals(const ObjectRef& other) const {
+#ifdef DEBUG
+  if (broker()->mode() == JSHeapBroker::kSerialized &&
+      data_->used_status == ObjectData::Usage::kUnused) {
+    data_->used_status = ObjectData::Usage::kOnlyIdentityUsed;
+  }
+#endif  // DEBUG
+  // TODO(jgruber): Consider going back to reference-equality on data_ once
+  // ObjectData objects are guaranteed to be canonicalized (see also:
+  // ClearReconstructibleData).
+  return data_->object().is_identical_to(other.data_->object());
+}
+
+Isolate* ObjectRef::isolate() const { return broker()->isolate(); }
+
+ContextRef ContextRef::previous(size_t* depth,
+                                SerializationPolicy policy) const {
+  DCHECK_NOT_NULL(depth);
+
+  if (data_->should_access_heap()) {
+    Context current = *object();
+    while (*depth != 0 && current.unchecked_previous().IsContext()) {
+      current = Context::cast(current.unchecked_previous());
+      (*depth)--;
+    }
+    return MakeRef(broker(), current);
+  }
+
+  if (*depth == 0) return *this;
+
+  ObjectData* previous_data = data()->AsContext()->previous(broker(), policy);
+  if (previous_data == nullptr || !previous_data->IsContext()) return *this;
+
+  *depth = *depth - 1;
+  return ContextRef(broker(), previous_data).previous(depth, policy);
+}
+
+base::Optional<ObjectRef> ContextRef::get(int index,
+                                          SerializationPolicy policy) const {
+  CHECK_LE(0, index);
+  if (data_->should_access_heap()) {
+    if (index >= object()->length()) return {};
+    return TryMakeRef(broker(), object()->get(index));
+  }
+  ObjectData* optional_slot =
+      data()->AsContext()->GetSlot(broker(), index, policy);
+  if (optional_slot == nullptr) return {};
+  return ObjectRef(broker(), optional_slot);
+}
+
+SourceTextModuleRef ContextRef::GetModule(SerializationPolicy policy) const {
+  ContextRef current = *this;
+  while (current.map().instance_type() != MODULE_CONTEXT_TYPE) {
+    size_t depth = 1;
+    current = current.previous(&depth, policy);
+    CHECK_EQ(depth, 0);
+  }
+  return current.get(Context::EXTENSION_INDEX, policy)
+      .value()
+      .AsSourceTextModule();
+}
+
+#ifdef DEBUG
+void JSHeapBroker::PrintRefsAnalysis() const {
+  // Usage counts
+  size_t used_total = 0, unused_total = 0, identity_used_total = 0;
+  for (RefsMap::Entry* ref = refs_->Start(); ref != nullptr;
+       ref = refs_->Next(ref)) {
+    switch (ref->value->used_status) {
+      case ObjectData::Usage::kUnused:
+        ++unused_total;
+        break;
+      case ObjectData::Usage::kOnlyIdentityUsed:
+        ++identity_used_total;
+        break;
+      case ObjectData::Usage::kDataUsed:
+        ++used_total;
+        break;
+    }
+  }
+
+  // Ref types analysis
+  TRACE_BROKER_MEMORY(
+      this, "Refs: " << refs_->occupancy() << "; data used: " << used_total
+                     << "; only identity used: " << identity_used_total
+                     << "; unused: " << unused_total);
+  size_t used_smis = 0, unused_smis = 0, identity_used_smis = 0;
+  size_t used[LAST_TYPE + 1] = {0};
+  size_t unused[LAST_TYPE + 1] = {0};
+  size_t identity_used[LAST_TYPE + 1] = {0};
+  for (RefsMap::Entry* ref = refs_->Start(); ref != nullptr;
+       ref = refs_->Next(ref)) {
+    if (ref->value->is_smi()) {
+      switch (ref->value->used_status) {
+        case ObjectData::Usage::kUnused:
+          ++unused_smis;
+          break;
+        case ObjectData::Usage::kOnlyIdentityUsed:
+          ++identity_used_smis;
+          break;
+        case ObjectData::Usage::kDataUsed:
+          ++used_smis;
+          break;
+      }
+    } else {
+      InstanceType instance_type;
+      if (ref->value->should_access_heap()) {
+        instance_type = Handle<HeapObject>::cast(ref->value->object())
+                            ->map()
+                            .instance_type();
+      } else {
+        instance_type = ref->value->AsHeapObject()->GetMapInstanceType();
+      }
+      CHECK_LE(FIRST_TYPE, instance_type);
+      CHECK_LE(instance_type, LAST_TYPE);
+      switch (ref->value->used_status) {
+        case ObjectData::Usage::kUnused:
+          ++unused[instance_type];
+          break;
+        case ObjectData::Usage::kOnlyIdentityUsed:
+          ++identity_used[instance_type];
+          break;
+        case ObjectData::Usage::kDataUsed:
+          ++used[instance_type];
+          break;
+      }
+    }
+  }
+
+  TRACE_BROKER_MEMORY(
+      this, "Smis: " << used_smis + identity_used_smis + unused_smis
+                     << "; data used: " << used_smis << "; only identity used: "
+                     << identity_used_smis << "; unused: " << unused_smis);
+  for (uint16_t i = FIRST_TYPE; i <= LAST_TYPE; ++i) {
+    size_t total = used[i] + identity_used[i] + unused[i];
+    if (total == 0) continue;
+    TRACE_BROKER_MEMORY(
+        this, InstanceType(i) << ": " << total << "; data used: " << used[i]
+                              << "; only identity used: " << identity_used[i]
+                              << "; unused: " << unused[i]);
+  }
+}
+#endif  // DEBUG
+
+void JSHeapBroker::InitializeAndStartSerializing() {
+  TraceScope tracer(this, "JSHeapBroker::InitializeAndStartSerializing");
+
+  CHECK_EQ(mode_, kDisabled);
+  mode_ = kSerializing;
+
+  // Throw away the dummy data that we created while disabled.
+  refs_->Clear();
+  refs_ =
+      zone()->New<RefsMap>(kInitialRefsBucketCount, AddressMatcher(), zone());
+
+  CollectArrayAndObjectPrototypes();
+
+  SetTargetNativeContextRef(target_native_context().object());
+  target_native_context().Serialize();
+  if (!is_concurrent_inlining()) {
+    // Perform full native context serialization now if we can't do it later on
+    // the background thread.
+    target_native_context().SerializeOnBackground();
+  }
+
+  Factory* const f = isolate()->factory();
+  if (!is_concurrent_inlining()) {
+    ObjectData* data;
+    data = GetOrCreateData(f->array_buffer_detaching_protector());
+    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
+    data = GetOrCreateData(f->array_constructor_protector());
+    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
+    data = GetOrCreateData(f->array_iterator_protector());
+    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
+    data = GetOrCreateData(f->array_species_protector());
+    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
+    data = GetOrCreateData(f->no_elements_protector());
+    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
+    data = GetOrCreateData(f->promise_hook_protector());
+    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
+    data = GetOrCreateData(f->promise_species_protector());
+    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
+    data = GetOrCreateData(f->promise_then_protector());
+    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
+    data = GetOrCreateData(f->string_length_protector());
+    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
+  }
+  GetOrCreateData(f->many_closures_cell());
+  GetOrCreateData(CodeFactory::CEntry(isolate(), 1, SaveFPRegsMode::kIgnore,
+                                      ArgvMode::kStack, true));
+
+  TRACE(this, "Finished serializing standard objects");
+}
+
+namespace {
+
+template <RefSerializationKind Kind, class DataT, class ObjectT>
+struct CreateDataFunctor {
+  bool operator()(JSHeapBroker* broker, RefsMap* refs,
+                  Handle<Object> object, RefsMap::Entry** entry_out,
+                  ObjectData** object_data_out) {
+    USE(broker, refs, object, entry_out, object_data_out);
+    UNREACHABLE();
+  }
+};
+
+template <class DataT, class ObjectT>
+struct CreateDataFunctor<RefSerializationKind::kSerialized, DataT, ObjectT> {
+  bool operator()(JSHeapBroker* broker, RefsMap* refs,
+                  Handle<Object> object, RefsMap::Entry** entry_out,
+                  ObjectData** object_data_out) {
+    if (broker->mode() == JSHeapBroker::kSerializing) {
+      RefsMap::Entry* entry = refs->LookupOrInsert(object.address());
+      *object_data_out = broker->zone()->New<DataT>(
+          broker, &entry->value, Handle<ObjectT>::cast(object));
+      *entry_out = entry;
+      return true;
+    }
+    return false;
+  }
+};
+
+template <class DataT, class ObjectT>
+struct CreateDataFunctor<RefSerializationKind::kBackgroundSerialized, DataT,
+                         ObjectT> {
+  bool operator()(JSHeapBroker* broker, RefsMap* refs,
+                  Handle<Object> object, RefsMap::Entry** entry_out,
+                  ObjectData** object_data_out) {
+    if (broker->is_concurrent_inlining()) {
+      RefsMap::Entry* entry = refs->LookupOrInsert(object.address());
+      *object_data_out = broker->zone()->New<DataT>(
+          broker, &entry->value, Handle<ObjectT>::cast(object),
+          kBackgroundSerializedHeapObject);
+      *entry_out = entry;
+      return true;
+    } else if (broker->mode() == JSHeapBroker::kSerializing) {
+      RefsMap::Entry* entry = refs->LookupOrInsert(object.address());
+      *object_data_out = broker->zone()->New<DataT>(
+          broker, &entry->value, Handle<ObjectT>::cast(object),
+          ObjectDataKind::kSerializedHeapObject);
+      *entry_out = entry;
+      return true;
+    }
+    return false;
+  }
+};
+
+template <class DataT, class ObjectT>
+struct CreateDataFunctor<RefSerializationKind::kNeverSerialized, DataT,
+                         ObjectT> {
+  bool operator()(JSHeapBroker* broker, RefsMap* refs, Handle<Object> object,
+                  RefsMap::Entry** entry_out, ObjectData** object_data_out) {
+    // TODO(solanes, v8:10866): Remove the `(mode() == kSerializing)` case
+    // below when all classes skip serialization. Same for similar spots if we
+    // end up keeping them.
+    if (broker->is_concurrent_inlining()) {
+      RefsMap::Entry* entry = refs->LookupOrInsert(object.address());
+      *object_data_out = broker->zone()->New<ObjectData>(
+          broker, &entry->value, object, kNeverSerializedHeapObject);
+      *entry_out = entry;
+      return true;
+    } else if (broker->mode() == JSHeapBroker::kSerializing) {
+      RefsMap::Entry* entry = refs->LookupOrInsert(object.address());
+      *object_data_out = broker->zone()->New<DataT>(
+          broker, &entry->value, Handle<ObjectT>::cast(object));
+      *entry_out = entry;
+      return true;
+    }
+    return false;
+  }
+};
+
+}  // namespace
+
+void JSHeapBroker::ClearReconstructibleData() {
+  RefsMap::Entry* p = refs_->Start();
+  while (p != nullptr) {
+    Address key = p->key;
+    ObjectData* value = p->value;
+    p = refs_->Next(p);
+    const auto kind = RefSerializationKindOf(value);
+    if (kind == RefSerializationKind::kNeverSerialized ||
+        kind == RefSerializationKind::kBackgroundSerialized) {
+      if (value->IsMap() &&
+          value->kind() == ObjectDataKind::kBackgroundSerializedHeapObject &&
+          value->AsMap()->has_extra_serialized_data()) {
+        continue;
+      }
+      // Can be reconstructed from the background thread.
+      CHECK_NOT_NULL(refs_->Remove(key));
+    }
+  }
+}
+
+ObjectData* JSHeapBroker::TryGetOrCreateData(Handle<Object> object,
+                                             GetOrCreateDataFlags flags) {
+  RefsMap::Entry* entry = refs_->Lookup(object.address());
+  if (entry != nullptr) return entry->value;
+
+  if (mode() == JSHeapBroker::kDisabled) {
+    entry = refs_->LookupOrInsert(object.address());
+    ObjectData** storage = &entry->value;
+    if (*storage == nullptr) {
+      entry->value = zone()->New<ObjectData>(
+          this, storage, object,
+          object->IsSmi() ? kSmi : kUnserializedHeapObject);
+    }
+    return *storage;
+  }
+
+  CHECK(mode() == JSHeapBroker::kSerializing ||
+        mode() == JSHeapBroker::kSerialized);
+
+  ObjectData* object_data;
+  if (object->IsSmi()) {
+    entry = refs_->LookupOrInsert(object.address());
+    return zone()->New<ObjectData>(this, &entry->value, object, kSmi);
+  }
+
+  DCHECK(!object->IsSmi());
+
+  const bool crash_on_error = (flags & kCrashOnError) != 0;
+
+  // TODO(jgruber): Remove this flag check (and the flag) once TSAN failures
+  // are fixed.
+  // See also: crbug.com/v8/11779
+  if (FLAG_turbo_concurrent_inlining_check_ispendingallocation) {
+    if ((flags & kAssumeMemoryFence) == 0 &&
+        ObjectMayBeUninitialized(HeapObject::cast(*object))) {
+      TRACE_BROKER_MISSING(this, "Object may be uninitialized " << *object);
+      CHECK_WITH_MSG(!crash_on_error, "Ref construction failed");
+      return nullptr;
+    }
+  }
+
+  if (IsReadOnlyHeapObjectForCompiler(HeapObject::cast(*object))) {
+    entry = refs_->LookupOrInsert(object.address());
+    return zone()->New<ObjectData>(this, &entry->value, object,
+                                   kUnserializedReadOnlyHeapObject);
+  }
+
+#define CREATE_DATA(Name, Kind)                                   \
+  if (object->Is##Name()) {                                       \
+    CreateDataFunctor<Kind, Name##Data, Name> f;                  \
+    if (!f(this, refs_, object, &entry, &object_data)) {          \
+      CHECK_WITH_MSG(!crash_on_error, "Ref construction failed"); \
+      return nullptr;                                             \
+    }                                                             \
+    /* NOLINTNEXTLINE(readability/braces) */                      \
+  } else
+  HEAP_BROKER_OBJECT_LIST(CREATE_DATA)
+#undef CREATE_DATA
+  {
+    UNREACHABLE();
+  }
+  // At this point the entry pointer is not guaranteed to be valid as
+  // the refs_ hash hable could be resized by one of the constructors above.
+  DCHECK_EQ(object_data, refs_->Lookup(object.address())->value);
+  return object_data;
+}
+
+#define DEFINE_IS_AND_AS(Name, ...)                               \
+  bool ObjectRef::Is##Name() const { return data()->Is##Name(); } \
+  Name##Ref ObjectRef::As##Name() const {                         \
+    DCHECK(Is##Name());                                           \
+    return Name##Ref(broker(), data());                           \
+  }
+HEAP_BROKER_OBJECT_LIST(DEFINE_IS_AND_AS)
+#undef DEFINE_IS_AND_AS
+
+bool ObjectRef::IsSmi() const { return data()->is_smi(); }
+
+int ObjectRef::AsSmi() const {
+  DCHECK(IsSmi());
+  // Handle-dereference is always allowed for Handle<Smi>.
+  return Handle<Smi>::cast(object())->value();
+}
+
+base::Optional<MapRef> JSObjectRef::GetObjectCreateMap() const {
+  if (data_->should_access_heap()) {
+    Handle<Map> instance_map;
+    if (Map::TryGetObjectCreateMap(broker()->isolate(), object())
+            .ToHandle(&instance_map)) {
+      return MakeRef(broker(), instance_map);
+    } else {
+      return base::Optional<MapRef>();
+    }
+  }
+  ObjectData* map_data = data()->AsJSObject()->object_create_map(broker());
+  if (map_data == nullptr) return base::Optional<MapRef>();
+  if (map_data->should_access_heap()) {
+    return MakeRef(broker(), Handle<Map>::cast(map_data->object()));
+  }
+  return MapRef(broker(), map_data->AsMap());
+}
+
+#define DEF_TESTER(Type, ...)                              \
+  bool MapRef::Is##Type##Map() const {                     \
+    return InstanceTypeChecker::Is##Type(instance_type()); \
+  }
+INSTANCE_TYPE_CHECKERS(DEF_TESTER)
+#undef DEF_TESTER
+
+base::Optional<MapRef> MapRef::AsElementsKind(ElementsKind kind) const {
+  if (data_->should_access_heap()) {
+    return MakeRef(broker(),
+                   Map::AsElementsKind(broker()->isolate(), object(), kind));
+  }
+  if (kind == elements_kind()) return *this;
+  const ZoneVector<ObjectData*>& elements_kind_generalizations =
+      data()->AsMap()->elements_kind_generalizations();
+  for (auto data : elements_kind_generalizations) {
+    MapRef map(broker(), data);
+    if (map.elements_kind() == kind) return map;
+  }
+  return base::Optional<MapRef>();
+}
+
+void MapRef::SerializeForElementLoad() {
+  if (data()->should_access_heap()) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsMap()->SerializeForElementLoad(broker());
+}
+
+void MapRef::SerializeForElementStore() {
+  if (data()->should_access_heap()) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsMap()->SerializeForElementStore(broker());
+}
+
+void MapData::SerializeForElementLoad(JSHeapBroker* broker) {
+  if (serialized_for_element_load_) return;
+  serialized_for_element_load_ = true;
+
+  TraceScope tracer(broker, this, "MapData::SerializeForElementLoad");
+  SerializePrototype(broker);
+}
+
+void MapData::SerializeForElementStore(JSHeapBroker* broker) {
+  if (serialized_for_element_store_) return;
+  serialized_for_element_store_ = true;
+
+  TraceScope tracer(broker, this, "MapData::SerializeForElementStore");
+  // TODO(solanes, v8:7790): This should use MapData methods rather than
+  // constructing MapRefs, but it involves non-trivial refactoring and this
+  // method should go away anyway once the compiler is fully concurrent.
+  MapRef map(broker, this);
+  do {
+    map.SerializePrototype();
+    map = map.prototype().value().map();
+  } while (map.IsJSObjectMap() && map.is_stable() &&
+           IsFastElementsKind(map.elements_kind()));
+}
+
+bool MapRef::HasOnlyStablePrototypesWithFastElements(
+    ZoneVector<MapRef>* prototype_maps) {
+  DCHECK_NOT_NULL(prototype_maps);
+  MapRef prototype_map = prototype().value().map();
+  while (prototype_map.oddball_type() != OddballType::kNull) {
+    if (!prototype_map.IsJSObjectMap() || !prototype_map.is_stable() ||
+        !IsFastElementsKind(prototype_map.elements_kind())) {
+      return false;
+    }
+    prototype_maps->push_back(prototype_map);
+    prototype_map = prototype_map.prototype().value().map();
+  }
+  return true;
+}
+
+bool MapRef::supports_fast_array_iteration() const {
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    return SupportsFastArrayIteration(broker(), object());
+  }
+  return data()->AsMap()->supports_fast_array_iteration();
+}
+
+bool MapRef::supports_fast_array_resize() const {
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    return SupportsFastArrayResize(broker(), object());
+  }
+  return data()->AsMap()->supports_fast_array_resize();
+}
+
+int JSFunctionRef::InitialMapInstanceSizeWithMinSlack() const {
+  if (data_->should_access_heap()) {
+    return object()->ComputeInstanceSizeWithMinSlack(broker()->isolate());
+  }
+  return data()->AsJSFunction()->initial_map_instance_size_with_min_slack();
+}
+
+OddballType MapRef::oddball_type() const {
+  if (instance_type() != ODDBALL_TYPE) {
+    return OddballType::kNone;
+  }
+  Factory* f = broker()->isolate()->factory();
+  if (equals(MakeRef(broker(), f->undefined_map()))) {
+    return OddballType::kUndefined;
+  }
+  if (equals(MakeRef(broker(), f->null_map()))) {
+    return OddballType::kNull;
+  }
+  if (equals(MakeRef(broker(), f->boolean_map()))) {
+    return OddballType::kBoolean;
+  }
+  if (equals(MakeRef(broker(), f->the_hole_map()))) {
+    return OddballType::kHole;
+  }
+  if (equals(MakeRef(broker(), f->uninitialized_map()))) {
+    return OddballType::kUninitialized;
+  }
+  DCHECK(equals(MakeRef(broker(), f->termination_exception_map())) ||
+         equals(MakeRef(broker(), f->arguments_marker_map())) ||
+         equals(MakeRef(broker(), f->optimized_out_map())) ||
+         equals(MakeRef(broker(), f->stale_register_map())));
+  return OddballType::kOther;
+}
+
+FeedbackCellRef FeedbackVectorRef::GetClosureFeedbackCell(int index) const {
+  if (data_->should_access_heap()) {
+    // These should all be available because we request the cell for each
+    // CreateClosure bytecode.
+    return MakeRef(broker(), object()->closure_feedback_cell(index));
+  }
+
+  return FeedbackCellRef(
+      broker(),
+      data()->AsFeedbackVector()->GetClosureFeedbackCell(broker(), index));
+}
+
+ObjectRef JSObjectRef::RawFastPropertyAt(FieldIndex index) const {
+  CHECK(index.is_inobject());
+  if (data_->should_access_heap()) {
+    return MakeRef(broker(), object()->RawFastPropertyAt(index));
+  }
+  JSObjectData* object_data = data()->AsJSObject();
+  return ObjectRef(broker(),
+                   object_data->GetInobjectField(index.property_index()));
+}
+
+bool AllocationSiteRef::IsFastLiteral() const {
+  if (data_->should_access_heap()) {
+    CHECK_NE(data_->kind(), ObjectDataKind::kNeverSerializedHeapObject);
+    return IsInlinableFastLiteral(
+        handle(object()->boilerplate(kAcquireLoad), broker()->isolate()));
+  }
+  return data()->AsAllocationSite()->IsFastLiteral();
+}
+
+void AllocationSiteRef::SerializeBoilerplate() {
+  if (data_->should_access_heap()) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsAllocationSite()->SerializeBoilerplate(broker());
+}
+
+void JSObjectRef::SerializeElements() {
+  if (data_->should_access_heap()) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsJSObject()->SerializeElements(broker());
+}
+
+void JSObjectRef::EnsureElementsTenured() {
+  if (data_->should_access_heap()) {
+    Handle<FixedArrayBase> object_elements = elements().value().object();
+    if (ObjectInYoungGeneration(*object_elements)) {
+      // If we would like to pretenure a fixed cow array, we must ensure that
+      // the array is already in old space, otherwise we'll create too many
+      // old-to-new-space pointers (overflowing the store buffer).
+      object_elements =
+          broker()->isolate()->factory()->CopyAndTenureFixedCOWArray(
+              Handle<FixedArray>::cast(object_elements));
+      object()->set_elements(*object_elements);
+    }
+    return;
+  }
+  CHECK(data()->AsJSObject()->cow_or_empty_elements_tenured());
+}
+
+FieldIndex MapRef::GetFieldIndexFor(InternalIndex descriptor_index) const {
+  CHECK_LT(descriptor_index.as_int(), NumberOfOwnDescriptors());
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    FieldIndex result = FieldIndex::ForDescriptor(*object(), descriptor_index);
+    DCHECK(result.is_inobject());
+    return result;
+  }
+  DescriptorArrayData* descriptors =
+      data()->AsMap()->instance_descriptors()->AsDescriptorArray();
+  FieldIndex result = descriptors->GetFieldIndexFor(descriptor_index);
+  DCHECK(result.is_inobject());
+  return result;
+}
+
+int MapRef::GetInObjectPropertyOffset(int i) const {
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    return object()->GetInObjectPropertyOffset(i);
+  }
+  return (GetInObjectPropertiesStartInWords() + i) * kTaggedSize;
+}
+
+PropertyDetails MapRef::GetPropertyDetails(
+    InternalIndex descriptor_index) const {
+  CHECK_LT(descriptor_index.as_int(), NumberOfOwnDescriptors());
+  return instance_descriptors().GetPropertyDetails(descriptor_index);
+}
+
+NameRef MapRef::GetPropertyKey(InternalIndex descriptor_index) const {
+  CHECK_LT(descriptor_index.as_int(), NumberOfOwnDescriptors());
+  return instance_descriptors().GetPropertyKey(descriptor_index);
+}
+
+bool MapRef::IsFixedCowArrayMap() const {
+  Handle<Map> fixed_cow_array_map =
+      ReadOnlyRoots(broker()->isolate()).fixed_cow_array_map_handle();
+  return equals(MakeRef(broker(), fixed_cow_array_map));
+}
+
+bool MapRef::IsPrimitiveMap() const {
+  return instance_type() <= LAST_PRIMITIVE_HEAP_OBJECT_TYPE;
+}
+
+MapRef MapRef::FindFieldOwner(InternalIndex descriptor_index) const {
+  CHECK_LT(descriptor_index.as_int(), NumberOfOwnDescriptors());
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    // TODO(solanes, v8:7790): Consider caching the result of the field owner on
+    // the descriptor array. It would be useful for same map as well as any
+    // other map sharing that descriptor array.
+    return MapRef(broker(), broker()->GetOrCreateData(object()->FindFieldOwner(
+                                broker()->isolate(), descriptor_index)));
+  }
+  DescriptorArrayData* descriptors =
+      data()->AsMap()->instance_descriptors()->AsDescriptorArray();
+  return MapRef(broker(), descriptors->FindFieldOwner(descriptor_index));
+}
+
+ObjectRef MapRef::GetFieldType(InternalIndex descriptor_index) const {
+  CHECK_LT(descriptor_index.as_int(), NumberOfOwnDescriptors());
+  return instance_descriptors().GetFieldType(descriptor_index);
+}
+
+base::Optional<ObjectRef> StringRef::GetCharAsStringOrUndefined(
+    uint32_t index, SerializationPolicy policy) const {
+  if (data_->should_access_heap()) {
+    // TODO(solanes, neis, v8:7790, v8:11012): Re-enable this optimization for
+    // concurrent inlining when we have the infrastructure to safely do so.
+    if (broker()->is_concurrent_inlining()) return base::nullopt;
+    CHECK_EQ(data_->kind(), ObjectDataKind::kUnserializedHeapObject);
+    return GetOwnElementFromHeap(broker(), object(), index, true);
+  }
+  ObjectData* element =
+      data()->AsString()->GetCharAsStringOrUndefined(broker(), index, policy);
+  if (element == nullptr) return base::nullopt;
+  return ObjectRef(broker(), element);
+}
+
+base::Optional<int> StringRef::length() const {
+  if (data_->should_access_heap()) {
+    if (data_->kind() == kNeverSerializedHeapObject &&
+        !this->IsInternalizedString()) {
+      TRACE_BROKER_MISSING(
+          broker(),
+          "length for kNeverSerialized non-internalized string " << *this);
+      return base::nullopt;
+    } else {
+      return object()->length(kAcquireLoad);
+    }
+  }
+  return data()->AsString()->length();
+}
+
+base::Optional<uint16_t> StringRef::GetFirstChar() {
+  if (data_->should_access_heap()) {
+    if (data_->kind() == kNeverSerializedHeapObject &&
+        !this->IsInternalizedString()) {
+      TRACE_BROKER_MISSING(
+          broker(),
+          "first char for kNeverSerialized non-internalized string " << *this);
+      return base::nullopt;
+    }
+
+    if (!broker()->IsMainThread()) {
+      return object()->Get(0, broker()->local_isolate());
+    } else {
+      // TODO(solanes, v8:7790): Remove this case once the inlining phase is
+      // done concurrently all the time.
+      return object()->Get(0);
+    }
+  }
+  return data()->AsString()->first_char();
+}
+
+base::Optional<double> StringRef::ToNumber() {
+  if (data_->should_access_heap()) {
+    if (data_->kind() == kNeverSerializedHeapObject &&
+        !this->IsInternalizedString()) {
+      TRACE_BROKER_MISSING(
+          broker(),
+          "number for kNeverSerialized non-internalized string " << *this);
+      return base::nullopt;
+    }
+
+    return TryStringToDouble(broker()->local_isolate(), object());
+  }
+  return data()->AsString()->to_number();
+}
+
+int ArrayBoilerplateDescriptionRef::constants_elements_length() const {
+  if (data_->should_access_heap()) {
+    return object()->constant_elements().length();
+  }
+  return data()->AsArrayBoilerplateDescription()->constants_elements_length();
+}
+
+ObjectRef FixedArrayRef::get(int i) const { return TryGet(i).value(); }
+
+base::Optional<ObjectRef> FixedArrayRef::TryGet(int i) const {
+  return TryMakeRef(broker(), object()->get(i, kRelaxedLoad));
+}
+
+Float64 FixedDoubleArrayRef::GetFromImmutableFixedDoubleArray(int i) const {
+  STATIC_ASSERT(ref_traits<FixedDoubleArray>::ref_serialization_kind ==
+                RefSerializationKind::kNeverSerialized);
+  return Float64::FromBits(object()->get_representation(i));
+}
+
+Handle<ByteArray> BytecodeArrayRef::SourcePositionTable() const {
+  return broker()->CanonicalPersistentHandle(object()->SourcePositionTable());
+}
+
+Address BytecodeArrayRef::handler_table_address() const {
+  return reinterpret_cast<Address>(
+      object()->handler_table().GetDataStartAddress());
+}
+
+int BytecodeArrayRef::handler_table_size() const {
+  return object()->handler_table().length();
+}
+
+#define IF_ACCESS_FROM_HEAP_C(name)  \
+  if (data_->should_access_heap()) { \
+    return object()->name();         \
+  }
+
+#define IF_ACCESS_FROM_HEAP(result, name)                     \
+  if (data_->should_access_heap()) {                          \
+    return MakeRef(broker(), result::cast(object()->name())); \
+  }
+
+// Macros for definining a const getter that, depending on the data kind,
+// either looks into the heap or into the serialized data.
+#define BIMODAL_ACCESSOR(holder, result, name)                             \
+  result##Ref holder##Ref::name() const {                                  \
+    IF_ACCESS_FROM_HEAP(result, name);                                     \
+    return result##Ref(broker(), ObjectRef::data()->As##holder()->name()); \
+  }
+
+// Like above except that the result type is not an XYZRef.
+#define BIMODAL_ACCESSOR_C(holder, result, name)    \
+  result holder##Ref::name() const {                \
+    IF_ACCESS_FROM_HEAP_C(name);                    \
+    return ObjectRef::data()->As##holder()->name(); \
+  }
+
+// Like above but for BitFields.
+#define BIMODAL_ACCESSOR_B(holder, field, name, BitField)              \
+  typename BitField::FieldType holder##Ref::name() const {             \
+    IF_ACCESS_FROM_HEAP_C(name);                                       \
+    return BitField::decode(ObjectRef::data()->As##holder()->field()); \
+  }
+
+// Like IF_ACCESS_FROM_HEAP[_C] but we also allow direct heap access for
+// kSerialized only for methods that we identified to be safe.
+#define IF_ACCESS_FROM_HEAP_WITH_FLAG(result, name)                        \
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) { \
+    return MakeRef(broker(), result::cast(object()->name()));              \
+  }
+#define IF_ACCESS_FROM_HEAP_WITH_FLAG_C(name)                              \
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) { \
+    return object()->name();                                               \
+  }
+
+// Like BIMODAL_ACCESSOR[_C] except that we force a direct heap access if
+// broker()->is_concurrent_inlining() is true (even for kSerialized). This is
+// because we identified the method to be safe to use direct heap access, but
+// the holder##Data class still needs to be serialized.
+#define BIMODAL_ACCESSOR_WITH_FLAG(holder, result, name)                   \
+  result##Ref holder##Ref::name() const {                                  \
+    IF_ACCESS_FROM_HEAP_WITH_FLAG(result, name);                           \
+    return result##Ref(broker(), ObjectRef::data()->As##holder()->name()); \
+  }
+#define BIMODAL_ACCESSOR_WITH_FLAG_C(holder, result, name) \
+  result holder##Ref::name() const {                       \
+    IF_ACCESS_FROM_HEAP_WITH_FLAG_C(name);                 \
+    return ObjectRef::data()->As##holder()->name();        \
+  }
+#define BIMODAL_ACCESSOR_WITH_FLAG_B(holder, field, name, BitField)    \
+  typename BitField::FieldType holder##Ref::name() const {             \
+    IF_ACCESS_FROM_HEAP_WITH_FLAG_C(name);                             \
+    return BitField::decode(ObjectRef::data()->As##holder()->field()); \
+  }
+
+BIMODAL_ACCESSOR(AllocationSite, Object, nested_site)
+BIMODAL_ACCESSOR_C(AllocationSite, bool, CanInlineCall)
+BIMODAL_ACCESSOR_C(AllocationSite, bool, PointsToLiteral)
+BIMODAL_ACCESSOR_C(AllocationSite, ElementsKind, GetElementsKind)
+BIMODAL_ACCESSOR_C(AllocationSite, AllocationType, GetAllocationType)
+
+BIMODAL_ACCESSOR_C(BigInt, uint64_t, AsUint64)
+
+BIMODAL_ACCESSOR_C(BytecodeArray, int, register_count)
+BIMODAL_ACCESSOR_C(BytecodeArray, int, parameter_count)
+BIMODAL_ACCESSOR_C(BytecodeArray, interpreter::Register,
+                   incoming_new_target_or_generator_register)
+
+BIMODAL_ACCESSOR_C(FeedbackVector, double, invocation_count)
+
+BIMODAL_ACCESSOR(HeapObject, Map, map)
+
+BIMODAL_ACCESSOR_C(HeapNumber, double, value)
+
+// These JSBoundFunction fields are immutable after initialization. Moreover,
+// as long as JSObjects are still serialized on the main thread, all
+// JSBoundFunctionRefs are created at a time when the underlying objects are
+// guaranteed to be fully initialized.
+BIMODAL_ACCESSOR_WITH_FLAG(JSBoundFunction, JSReceiver, bound_target_function)
+BIMODAL_ACCESSOR_WITH_FLAG(JSBoundFunction, Object, bound_this)
+BIMODAL_ACCESSOR_WITH_FLAG(JSBoundFunction, FixedArray, bound_arguments)
+
+BIMODAL_ACCESSOR_C(JSDataView, size_t, byte_length)
+
+BIMODAL_ACCESSOR_C(JSFunction, bool, has_feedback_vector)
+BIMODAL_ACCESSOR_C(JSFunction, bool, has_initial_map)
+BIMODAL_ACCESSOR_C(JSFunction, bool, has_prototype)
+BIMODAL_ACCESSOR_C(JSFunction, bool, PrototypeRequiresRuntimeLookup)
+BIMODAL_ACCESSOR(JSFunction, Context, context)
+BIMODAL_ACCESSOR(JSFunction, NativeContext, native_context)
+BIMODAL_ACCESSOR(JSFunction, Map, initial_map)
+BIMODAL_ACCESSOR(JSFunction, Object, prototype)
+BIMODAL_ACCESSOR(JSFunction, SharedFunctionInfo, shared)
+BIMODAL_ACCESSOR(JSFunction, FeedbackCell, raw_feedback_cell)
+BIMODAL_ACCESSOR(JSFunction, FeedbackVector, feedback_vector)
+
+BIMODAL_ACCESSOR_C(JSGlobalObject, bool, IsDetached)
+
+BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field2, elements_kind,
+                             Map::Bits2::ElementsKindBits)
+BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field3, is_dictionary_map,
+                             Map::Bits3::IsDictionaryMapBit)
+BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field3, is_deprecated,
+                             Map::Bits3::IsDeprecatedBit)
+BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field3, NumberOfOwnDescriptors,
+                             Map::Bits3::NumberOfOwnDescriptorsBits)
+BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field3, is_migration_target,
+                             Map::Bits3::IsMigrationTargetBit)
+BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field, has_prototype_slot,
+                             Map::Bits1::HasPrototypeSlotBit)
+BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field, is_access_check_needed,
+                             Map::Bits1::IsAccessCheckNeededBit)
+BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field, is_callable,
+                             Map::Bits1::IsCallableBit)
+BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field, has_indexed_interceptor,
+                             Map::Bits1::HasIndexedInterceptorBit)
+BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field, is_constructor,
+                             Map::Bits1::IsConstructorBit)
+BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field, is_undetectable,
+                             Map::Bits1::IsUndetectableBit)
+BIMODAL_ACCESSOR_C(Map, int, instance_size)
+BIMODAL_ACCESSOR_WITH_FLAG_C(Map, int, NextFreePropertyIndex)
+BIMODAL_ACCESSOR_C(Map, int, UnusedPropertyFields)
+BIMODAL_ACCESSOR_WITH_FLAG_C(Map, InstanceType, instance_type)
+BIMODAL_ACCESSOR_WITH_FLAG(Map, Object, GetConstructor)
+BIMODAL_ACCESSOR_WITH_FLAG(Map, HeapObject, GetBackPointer)
+BIMODAL_ACCESSOR_C(Map, bool, is_abandoned_prototype_map)
+
+#define DEF_NATIVE_CONTEXT_ACCESSOR(type, name) \
+  BIMODAL_ACCESSOR(NativeContext, type, name)
+BROKER_NATIVE_CONTEXT_FIELDS(DEF_NATIVE_CONTEXT_ACCESSOR)
+#undef DEF_NATIVE_CONTEXT_ACCESSOR
+
+BIMODAL_ACCESSOR_C(ObjectBoilerplateDescription, int, size)
+
+BIMODAL_ACCESSOR(PropertyCell, Object, value)
+BIMODAL_ACCESSOR_C(PropertyCell, PropertyDetails, property_details)
+
+BIMODAL_ACCESSOR(RegExpBoilerplateDescription, FixedArray, data)
+BIMODAL_ACCESSOR(RegExpBoilerplateDescription, String, source)
+BIMODAL_ACCESSOR_C(RegExpBoilerplateDescription, int, flags)
+
+base::Optional<CallHandlerInfoRef> FunctionTemplateInfoRef::call_code() const {
+  if (data_->should_access_heap()) {
+    HeapObject call_code = object()->call_code(kAcquireLoad);
+    if (call_code.IsUndefined()) return base::nullopt;
+    return TryMakeRef(broker(), CallHandlerInfo::cast(call_code));
+  }
+  ObjectData* call_code = data()->AsFunctionTemplateInfo()->call_code();
+  if (!call_code) return base::nullopt;
+  return CallHandlerInfoRef(broker(), call_code);
+}
+
+bool FunctionTemplateInfoRef::is_signature_undefined() const {
+  if (data_->should_access_heap()) {
+    return object()->signature().IsUndefined(broker()->isolate());
+  }
+  return data()->AsFunctionTemplateInfo()->is_signature_undefined();
+}
+
+bool FunctionTemplateInfoRef::has_call_code() const {
+  if (data_->should_access_heap()) {
+    HeapObject call_code = object()->call_code(kAcquireLoad);
+    return !call_code.IsUndefined();
+  }
+  return data()->AsFunctionTemplateInfo()->has_call_code();
+}
+
+bool FunctionTemplateInfoRef ::accept_any_receiver() const {
+  if (data_->should_access_heap()) {
+    return object()->accept_any_receiver();
+  }
+  return ObjectRef ::data()->AsFunctionTemplateInfo()->accept_any_receiver();
+}
+
+HolderLookupResult FunctionTemplateInfoRef::LookupHolderOfExpectedType(
+    MapRef receiver_map, SerializationPolicy policy) {
+  const HolderLookupResult not_found;
+
+  if (data_->should_access_heap()) {
+    // There are currently two ways we can see a FunctionTemplateInfo on the
+    // background thread: 1.) As part of a SharedFunctionInfo and 2.) in an
+    // AccessorPair. In both cases, the FTI is fully constructed on the main
+    // thread before.
+    // TODO(nicohartmann@, v8:7790): Once the above no longer holds, we might
+    // have to use the GC predicate to check whether objects are fully
+    // initialized and safe to read.
+    if (!receiver_map.IsJSReceiverMap() ||
+        (receiver_map.is_access_check_needed() &&
+         !object()->accept_any_receiver())) {
+      return not_found;
+    }
+
+    if (!receiver_map.IsJSObjectMap()) return not_found;
+
+    DCHECK(has_call_code());
+
+    DisallowGarbageCollection no_gc;
+    HeapObject signature = object()->signature();
+    if (signature.IsUndefined()) {
+      return HolderLookupResult(CallOptimization::kHolderIsReceiver);
+    }
+    auto expected_receiver_type = FunctionTemplateInfo::cast(signature);
+    if (expected_receiver_type.IsTemplateFor(*receiver_map.object())) {
+      return HolderLookupResult(CallOptimization::kHolderIsReceiver);
+    }
+
+    if (!receiver_map.IsJSGlobalProxyMap()) return not_found;
+    if (policy == SerializationPolicy::kSerializeIfNeeded) {
+      receiver_map.SerializePrototype();
+    }
+    base::Optional<HeapObjectRef> prototype = receiver_map.prototype();
+    if (!prototype.has_value()) return not_found;
+    if (prototype->IsNull()) return not_found;
+
+    JSObject raw_prototype = JSObject::cast(*prototype->object());
+    if (!expected_receiver_type.IsTemplateFor(raw_prototype.map())) {
+      return not_found;
+    }
+    return HolderLookupResult(CallOptimization::kHolderFound,
+                              prototype->AsJSObject());
+  }
+
+  FunctionTemplateInfoData* fti_data = data()->AsFunctionTemplateInfo();
+  KnownReceiversMap::iterator lookup_it =
+      fti_data->known_receivers().find(receiver_map.data());
+  if (lookup_it != fti_data->known_receivers().cend()) {
+    return lookup_it->second;
+  }
+  if (policy == SerializationPolicy::kAssumeSerialized) {
+    TRACE_BROKER_MISSING(broker(),
+                         "holder for receiver with map " << receiver_map);
+    return not_found;
+  }
+  if (!receiver_map.IsJSReceiverMap() ||
+      (receiver_map.is_access_check_needed() && !accept_any_receiver())) {
+    fti_data->known_receivers().insert({receiver_map.data(), not_found});
+    return not_found;
+  }
+
+  HolderLookupResult result;
+  CallOptimization call_optimization(broker()->local_isolate_or_isolate(),
+                                     object());
+  Handle<JSObject> holder = broker()->CanonicalPersistentHandle(
+      call_optimization.LookupHolderOfExpectedType(
+          broker()->local_isolate_or_isolate(), receiver_map.object(),
+          &result.lookup));
+
+  switch (result.lookup) {
+    case CallOptimization::kHolderFound: {
+      result.holder = MakeRef(broker(), holder);
+      fti_data->known_receivers().insert({receiver_map.data(), result});
+      break;
+    }
+    default: {
+      DCHECK_EQ(result.holder, base::nullopt);
+      fti_data->known_receivers().insert({receiver_map.data(), result});
+    }
+  }
+  return result;
+}
+
+BIMODAL_ACCESSOR(CallHandlerInfo, Object, data)
+
+BIMODAL_ACCESSOR_C(ScopeInfo, int, ContextLength)
+BIMODAL_ACCESSOR_C(ScopeInfo, bool, HasContextExtensionSlot)
+BIMODAL_ACCESSOR_C(ScopeInfo, bool, HasOuterScopeInfo)
+BIMODAL_ACCESSOR(ScopeInfo, ScopeInfo, OuterScopeInfo)
+
+BIMODAL_ACCESSOR_C(SharedFunctionInfo, int, builtin_id)
+BytecodeArrayRef SharedFunctionInfoRef::GetBytecodeArray() const {
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    BytecodeArray bytecode_array;
+    if (!broker()->IsMainThread()) {
+      bytecode_array = object()->GetBytecodeArray(broker()->local_isolate());
+    } else {
+      bytecode_array = object()->GetBytecodeArray(broker()->isolate());
+    }
+    return MakeRef(broker(), bytecode_array);
+  }
+  return BytecodeArrayRef(
+      broker(), ObjectRef ::data()->AsSharedFunctionInfo()->GetBytecodeArray());
+}
+#define DEF_SFI_ACCESSOR(type, name) \
+  BIMODAL_ACCESSOR_WITH_FLAG_C(SharedFunctionInfo, type, name)
+BROKER_SFI_FIELDS(DEF_SFI_ACCESSOR)
+#undef DEF_SFI_ACCESSOR
+SharedFunctionInfo::Inlineability SharedFunctionInfoRef::GetInlineability()
+    const {
+  if (data_->should_access_heap()) {
+    if (!broker()->IsMainThread()) {
+      return object()->GetInlineability(broker()->local_isolate());
+    } else {
+      return object()->GetInlineability(broker()->isolate());
+    }
+  }
+  return ObjectRef ::data()->AsSharedFunctionInfo()->GetInlineability();
+}
+
+base::Optional<FeedbackVectorRef> FeedbackCellRef::value() const {
+  if (data_->should_access_heap()) {
+    // Note that we use the synchronized accessor.
+    Object value = object()->value(kAcquireLoad);
+    if (!value.IsFeedbackVector()) return base::nullopt;
+    return TryMakeRef(broker(), FeedbackVector::cast(value));
+  }
+  ObjectData* vector = ObjectRef::data()->AsFeedbackCell()->value();
+  return FeedbackVectorRef(broker(), vector->AsFeedbackVector());
+}
+
+base::Optional<ObjectRef> MapRef::GetStrongValue(
+    InternalIndex descriptor_index) const {
+  CHECK_LT(descriptor_index.as_int(), NumberOfOwnDescriptors());
+  return instance_descriptors().GetStrongValue(descriptor_index);
+}
+
+DescriptorArrayRef MapRef::instance_descriptors() const {
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    return MakeRefAssumeMemoryFence(
+        broker(),
+        object()->instance_descriptors(broker()->isolate(), kAcquireLoad));
+  }
+
+  return DescriptorArrayRef(broker(), data()->AsMap()->instance_descriptors());
+}
+
+base::Optional<HeapObjectRef> MapRef::prototype() const {
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    return TryMakeRef(broker(), HeapObject::cast(object()->prototype()));
+  }
+  ObjectData* prototype_data = data()->AsMap()->prototype();
+  if (prototype_data == nullptr) {
+    TRACE_BROKER_MISSING(broker(), "prototype for map " << *this);
+    return {};
+  }
+  return HeapObjectRef(broker(), prototype_data);
+}
+
+void MapRef::SerializeRootMap() {
+  if (data_->should_access_heap()) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsMap()->SerializeRootMap(broker());
+}
+
+// TODO(solanes, v8:7790): Remove base::Optional from the return type when
+// deleting serialization.
+base::Optional<MapRef> MapRef::FindRootMap() const {
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    // TODO(solanes): Change TryMakeRef to MakeRef when Map is moved to
+    // kNeverSerialized.
+    // TODO(solanes, v8:7790): Consider caching the result of the root map.
+    return TryMakeRef(broker(), object()->FindRootMap(broker()->isolate()));
+  }
+  ObjectData* map_data = data()->AsMap()->FindRootMap();
+  if (map_data != nullptr) {
+    return MapRef(broker(), map_data);
+  }
+  TRACE_BROKER_MISSING(broker(), "root map for object " << *this);
+  return base::nullopt;
+}
+
+bool JSTypedArrayRef::is_on_heap() const {
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    // Safe to read concurrently because:
+    // - host object seen by serializer.
+    // - underlying field written 1. during initialization or 2. with
+    //   release-store.
+    return object()->is_on_heap(kAcquireLoad);
+  }
+  return data()->AsJSTypedArray()->data_ptr();
+}
+
+size_t JSTypedArrayRef::length() const {
+  CHECK(!is_on_heap());
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    // Safe to read concurrently because:
+    // - immutable after initialization.
+    // - host object seen by serializer.
+    return object()->length();
+  }
+  return data()->AsJSTypedArray()->length();
+}
+
+HeapObjectRef JSTypedArrayRef::buffer() const {
+  CHECK(!is_on_heap());
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    // Safe to read concurrently because:
+    // - immutable after initialization.
+    // - host object seen by serializer.
+    return MakeRef<HeapObject>(broker(), object()->buffer());
+  }
+  return HeapObjectRef{broker(), data()->AsJSTypedArray()->buffer()};
+}
+
+void* JSTypedArrayRef::data_ptr() const {
+  CHECK(!is_on_heap());
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    // Safe to read concurrently because:
+    // - host object seen by serializer.
+    // - underlying field written 1. during initialization or 2. protected by
+    //   the is_on_heap release/acquire semantics (external_pointer store
+    //   happens-before base_pointer store, and this external_pointer load
+    //   happens-after base_pointer load).
+    STATIC_ASSERT(JSTypedArray::kOffHeapDataPtrEqualsExternalPointer);
+    return object()->DataPtr();
+  }
+  return data()->AsJSTypedArray()->data_ptr();
+}
+
+bool MapRef::IsInobjectSlackTrackingInProgress() const {
+  IF_ACCESS_FROM_HEAP_WITH_FLAG_C(IsInobjectSlackTrackingInProgress);
+  return Map::Bits3::ConstructionCounterBits::decode(
+             data()->AsMap()->bit_field3()) != Map::kNoSlackTracking;
+}
+
+int MapRef::constructor_function_index() const {
+  IF_ACCESS_FROM_HEAP_WITH_FLAG_C(GetConstructorFunctionIndex);
+  CHECK(IsPrimitiveMap());
+  return data()->AsMap()->constructor_function_index();
+}
+
+bool MapRef::is_stable() const {
+  IF_ACCESS_FROM_HEAP_C(is_stable);
+  return !Map::Bits3::IsUnstableBit::decode(data()->AsMap()->bit_field3());
+}
+
+bool MapRef::CanBeDeprecated() const {
+  IF_ACCESS_FROM_HEAP_WITH_FLAG_C(CanBeDeprecated);
+  CHECK_GT(NumberOfOwnDescriptors(), 0);
+  return data()->AsMap()->can_be_deprecated();
+}
+
+bool MapRef::CanTransition() const {
+  IF_ACCESS_FROM_HEAP_WITH_FLAG_C(CanTransition);
+  return data()->AsMap()->can_transition();
+}
+
+int MapRef::GetInObjectPropertiesStartInWords() const {
+  IF_ACCESS_FROM_HEAP_WITH_FLAG_C(GetInObjectPropertiesStartInWords);
+  return data()->AsMap()->in_object_properties_start_in_words();
+}
+
+int MapRef::GetInObjectProperties() const {
+  IF_ACCESS_FROM_HEAP_C(GetInObjectProperties);
+  return data()->AsMap()->in_object_properties();
+}
+
+void ScopeInfoRef::SerializeScopeInfoChain() {
+  if (data_->should_access_heap()) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsScopeInfo()->SerializeScopeInfoChain(broker());
+}
+
+bool StringRef::IsExternalString() const {
+  IF_ACCESS_FROM_HEAP_C(IsExternalString);
+  return data()->AsString()->is_external_string();
+}
+
+Address CallHandlerInfoRef::callback() const {
+  if (data_->should_access_heap()) {
+    return v8::ToCData<Address>(object()->callback());
+  }
+  return HeapObjectRef::data()->AsCallHandlerInfo()->callback();
+}
+
+ZoneVector<Address> FunctionTemplateInfoRef::c_functions() const {
+  if (data_->should_access_heap()) {
+    return GetCFunctions(FixedArray::cast(object()->GetCFunctionOverloads()),
+                         broker()->zone());
+  }
+  return HeapObjectRef::data()->AsFunctionTemplateInfo()->c_functions();
+}
+
+ZoneVector<const CFunctionInfo*> FunctionTemplateInfoRef::c_signatures() const {
+  if (data_->should_access_heap()) {
+    return GetCSignatures(FixedArray::cast(object()->GetCFunctionOverloads()),
+                          broker()->zone());
+  }
+  return HeapObjectRef::data()->AsFunctionTemplateInfo()->c_signatures();
+}
+
+bool StringRef::IsSeqString() const {
+  IF_ACCESS_FROM_HEAP_C(IsSeqString);
+  return data()->AsString()->is_seq_string();
+}
+
+bool NativeContextRef::is_unserialized_heap_object() const {
+  return data_->kind() == kUnserializedHeapObject;
+}
+
+ScopeInfoRef NativeContextRef::scope_info() const {
+  if (data_->should_access_heap()) {
+    // The scope_info is immutable after initialization.
+    return MakeRefAssumeMemoryFence(broker(), object()->scope_info());
+  }
+  return ScopeInfoRef(broker(), data()->AsNativeContext()->scope_info());
+}
+
+SharedFunctionInfoRef FeedbackVectorRef::shared_function_info() const {
+  if (data_->should_access_heap()) {
+    return MakeRef(broker(), object()->shared_function_info());
+  }
+
+  return SharedFunctionInfoRef(
+      broker(), data()->AsFeedbackVector()->shared_function_info());
+}
+
+MapRef NativeContextRef::GetFunctionMapFromIndex(int index) const {
+  DCHECK_GE(index, Context::FIRST_FUNCTION_MAP_INDEX);
+  DCHECK_LE(index, Context::LAST_FUNCTION_MAP_INDEX);
+  if (data_->should_access_heap()) {
+    CHECK_LT(index, object()->length());
+    return MakeRefAssumeMemoryFence(broker(),
+                                    object()->get(index, kAcquireLoad))
+        .AsMap();
+  }
+  return MapRef(broker(), data()->AsNativeContext()->function_maps().at(
+                              index - Context::FIRST_FUNCTION_MAP_INDEX));
+}
+
+MapRef NativeContextRef::GetInitialJSArrayMap(ElementsKind kind) const {
+  switch (kind) {
+    case PACKED_SMI_ELEMENTS:
+      return js_array_packed_smi_elements_map();
+    case HOLEY_SMI_ELEMENTS:
+      return js_array_holey_smi_elements_map();
+    case PACKED_DOUBLE_ELEMENTS:
+      return js_array_packed_double_elements_map();
+    case HOLEY_DOUBLE_ELEMENTS:
+      return js_array_holey_double_elements_map();
+    case PACKED_ELEMENTS:
+      return js_array_packed_elements_map();
+    case HOLEY_ELEMENTS:
+      return js_array_holey_elements_map();
+    default:
+      UNREACHABLE();
+  }
+}
+
+base::Optional<JSFunctionRef> NativeContextRef::GetConstructorFunction(
+    const MapRef& map) const {
+  CHECK(map.IsPrimitiveMap());
+  switch (map.constructor_function_index()) {
+    case Map::kNoConstructorFunctionIndex:
+      return base::nullopt;
+    case Context::BIGINT_FUNCTION_INDEX:
+      return bigint_function();
+    case Context::BOOLEAN_FUNCTION_INDEX:
+      return boolean_function();
+    case Context::NUMBER_FUNCTION_INDEX:
+      return number_function();
+    case Context::STRING_FUNCTION_INDEX:
+      return string_function();
+    case Context::SYMBOL_FUNCTION_INDEX:
+      return symbol_function();
+    default:
+      UNREACHABLE();
+  }
+}
+
+bool ObjectRef::IsNull() const { return object()->IsNull(); }
+
+bool ObjectRef::IsNullOrUndefined() const {
+  if (IsSmi()) return false;
+  OddballType type = AsHeapObject().map().oddball_type();
+  return type == OddballType::kNull || type == OddballType::kUndefined;
+}
+
+bool ObjectRef::IsTheHole() const {
+  return IsHeapObject() &&
+         AsHeapObject().map().oddball_type() == OddballType::kHole;
+}
+
+base::Optional<bool> ObjectRef::TryGetBooleanValue() const {
+  if (data_->should_access_heap()) {
+    return object()->BooleanValue(broker()->isolate());
+  }
+  if (IsSmi()) return AsSmi() != 0;
+  return data()->AsHeapObject()->TryGetBooleanValue(broker());
+}
+
+Maybe<double> ObjectRef::OddballToNumber() const {
+  OddballType type = AsHeapObject().map().oddball_type();
+
+  switch (type) {
+    case OddballType::kBoolean: {
+      ObjectRef true_ref(broker(),
+                         broker()->isolate()->factory()->true_value());
+      return this->equals(true_ref) ? Just(1.0) : Just(0.0);
+      break;
+    }
+    case OddballType::kUndefined: {
+      return Just(std::numeric_limits<double>::quiet_NaN());
+      break;
+    }
+    case OddballType::kNull: {
+      return Just(0.0);
+      break;
+    }
+    default: {
+      return Nothing<double>();
+      break;
+    }
+  }
+}
+
+base::Optional<ObjectRef> JSObjectRef::GetOwnConstantElement(
+    uint32_t index, SerializationPolicy policy) const {
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    // `elements` are currently still serialized as members of JSObjectRef.
+    // TODO(jgruber,v8:7790): Once JSObject is no longer serialized, we must
+    // guarantee consistency between `object`, `elements_kind` and `elements`
+    // through other means (store/load order? locks? storing elements_kind in
+    // elements.map?).
+    STATIC_ASSERT(IsSerializedRef<JSObject>());
+
+    base::Optional<FixedArrayBaseRef> maybe_elements_ref = elements();
+    if (!maybe_elements_ref.has_value()) {
+      TRACE_BROKER_MISSING(broker(), "JSObject::elements" << *this);
+      return {};
+    }
+
+    FixedArrayBaseRef elements_ref = maybe_elements_ref.value();
+    ElementsKind elements_kind = GetElementsKind();
+
+    DCHECK_LE(index, JSObject::kMaxElementIndex);
+
+    // See also ElementsAccessorBase::GetMaxIndex.
+    if (IsJSArray()) {
+      // For JSArrays we additionally need to check against JSArray::length.
+      // Length_unsafe is safe to use in this case since:
+      // - GetOwnConstantElement only detects a constant for JSArray holders if
+      //   the array is frozen/sealed.
+      // - Frozen/sealed arrays can't change length.
+      // - We've already seen a map with frozen/sealed elements_kinds (above);
+      // - The release-load of that map ensures we read the newest value
+      //   of `length` below.
+      uint32_t array_length;
+      if (!AsJSArray().length_unsafe().object()->ToArrayLength(&array_length)) {
+        return {};
+      }
+      if (index >= array_length) return {};
+    }
+
+    Object maybe_element;
+    auto result = ConcurrentLookupIterator::TryGetOwnConstantElement(
+        &maybe_element, broker()->isolate(), broker()->local_isolate(),
+        *object(), *elements_ref.object(), elements_kind, index);
+
+    if (result == ConcurrentLookupIterator::kGaveUp) {
+      TRACE_BROKER_MISSING(broker(), "JSObject::GetOwnConstantElement on "
+                                         << *this << " at index " << index);
+      return {};
+    } else if (result == ConcurrentLookupIterator::kNotPresent) {
+      return {};
+    }
+
+    DCHECK_EQ(result, ConcurrentLookupIterator::kPresent);
+    return MakeRef(broker(), maybe_element);
+  } else {
+    ObjectData* element =
+        data()->AsJSObject()->GetOwnConstantElement(broker(), index, policy);
+    if (element == nullptr) return base::nullopt;
+    return ObjectRef(broker(), element);
+  }
+}
+
+base::Optional<ObjectRef> JSObjectRef::GetOwnFastDataProperty(
+    Representation field_representation, FieldIndex index,
+    SerializationPolicy policy) const {
+  if (data_->should_access_heap()) {
+    return GetOwnFastDataPropertyFromHeap(broker(),
+                                          Handle<JSObject>::cast(object()),
+                                          field_representation, index);
+  }
+  ObjectData* property = data()->AsJSObject()->GetOwnFastDataProperty(
+      broker(), field_representation, index, policy);
+  if (property == nullptr) return base::nullopt;
+  return ObjectRef(broker(), property);
+}
+
+ObjectRef JSObjectRef::GetOwnDictionaryProperty(
+    InternalIndex index, SerializationPolicy policy) const {
+  CHECK(index.is_found());
+  if (data_->should_access_heap()) {
+    return GetOwnDictionaryPropertyFromHeap(
+        broker(), Handle<JSObject>::cast(object()), index);
+  }
+  ObjectData* property =
+      data()->AsJSObject()->GetOwnDictionaryProperty(broker(), index, policy);
+  CHECK_NE(property, nullptr);
+  return ObjectRef(broker(), property);
+}
+
+ObjectRef JSArrayRef::GetBoilerplateLength() const {
+  // Safe to read concurrently because:
+  // - boilerplates are immutable after initialization.
+  // - boilerplates are published into the feedback vector.
+  return length_unsafe();
+}
+
+ObjectRef JSArrayRef::length_unsafe() const {
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    return MakeRef(broker(),
+                   object()->length(broker()->isolate(), kRelaxedLoad));
+  } else {
+    return ObjectRef{broker(), data()->AsJSArray()->length()};
+  }
+}
+
+base::Optional<ObjectRef> JSArrayRef::GetOwnCowElement(
+    FixedArrayBaseRef elements_ref, uint32_t index,
+    SerializationPolicy policy) const {
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    // `elements` are currently still serialized as members of JSObjectRef.
+    // TODO(jgruber,v8:7790): Remove the elements equality DCHECK below once
+    // JSObject is no longer serialized.
+    static_assert(std::is_base_of<JSObject, JSArray>::value, "");
+    STATIC_ASSERT(IsSerializedRef<JSObject>());
+
+    // The elements_ref is passed in by callers to make explicit that it is
+    // also used outside of this function, and must match the `elements` used
+    // inside this function.
+    DCHECK(elements_ref.equals(elements().value()));
+
+    // Due to concurrency, the kind read here may not be consistent with
+    // `elements_ref`. But consistency is guaranteed at runtime due to the
+    // `elements` equality check in the caller.
+    ElementsKind elements_kind = GetElementsKind();
+
+    // We only inspect fixed COW arrays, which may only occur for fast
+    // smi/objects elements kinds.
+    if (!IsSmiOrObjectElementsKind(elements_kind)) return {};
+    DCHECK(IsFastElementsKind(elements_kind));
+    if (!elements_ref.map().IsFixedCowArrayMap()) return {};
+
+    // As the name says, the `length` read here is unsafe and may not match
+    // `elements`. We rely on the invariant that any `length` change will
+    // also result in an `elements` change to make this safe. The `elements`
+    // equality check in the caller thus also guards the value of `length`.
+    ObjectRef length_ref = length_unsafe();
+
+    // Likewise we only deal with smi lengths.
+    if (!length_ref.IsSmi()) return {};
+
+    base::Optional<Object> result =
+        ConcurrentLookupIterator::TryGetOwnCowElement(
+            broker()->isolate(), *elements_ref.AsFixedArray().object(),
+            elements_kind, length_ref.AsSmi(), index);
+    if (!result.has_value()) return {};
+
+    return MakeRef(broker(), result.value());
+  } else {
+    DCHECK(!data_->should_access_heap());
+    DCHECK(!broker()->is_concurrent_inlining());
+
+    // Just to clarify that `elements_ref` is not used on this path.
+    // GetOwnElement accesses the serialized `elements` field on its own.
+    USE(elements_ref);
+
+    if (!elements().value().map().IsFixedCowArrayMap()) return base::nullopt;
+
+    ObjectData* element =
+        data()->AsJSArray()->GetOwnElement(broker(), index, policy);
+    if (element == nullptr) return base::nullopt;
+    return ObjectRef(broker(), element);
+  }
+}
+
+base::Optional<CellRef> SourceTextModuleRef::GetCell(int cell_index) const {
+  if (data_->should_access_heap()) {
+    return TryMakeRef(broker(), object()->GetCell(cell_index));
+  }
+  ObjectData* cell =
+      data()->AsSourceTextModule()->GetCell(broker(), cell_index);
+  if (cell == nullptr) return base::nullopt;
+  return CellRef(broker(), cell);
+}
+
+base::Optional<ObjectRef> SourceTextModuleRef::import_meta() const {
+  if (data_->should_access_heap()) {
+    return TryMakeRef(broker(), object()->import_meta(kAcquireLoad));
+  }
+  return ObjectRef(broker(),
+                   data()->AsSourceTextModule()->GetImportMeta(broker()));
+}
+
+ObjectRef::ObjectRef(JSHeapBroker* broker, Handle<Object> object,
+                     bool check_type)
+    : broker_(broker) {
+  CHECK_NE(broker->mode(), JSHeapBroker::kRetired);
+  data_ = broker->GetOrCreateData(object);
+}
+
+namespace {
+
+OddballType GetOddballType(Isolate* isolate, Map map) {
+  if (map.instance_type() != ODDBALL_TYPE) {
+    return OddballType::kNone;
+  }
+  ReadOnlyRoots roots(isolate);
+  if (map == roots.undefined_map()) {
+    return OddballType::kUndefined;
+  }
+  if (map == roots.null_map()) {
+    return OddballType::kNull;
+  }
+  if (map == roots.boolean_map()) {
+    return OddballType::kBoolean;
+  }
+  if (map == roots.the_hole_map()) {
+    return OddballType::kHole;
+  }
+  if (map == roots.uninitialized_map()) {
+    return OddballType::kUninitialized;
+  }
+  DCHECK(map == roots.termination_exception_map() ||
+         map == roots.arguments_marker_map() ||
+         map == roots.optimized_out_map() || map == roots.stale_register_map());
+  return OddballType::kOther;
+}
+
+}  // namespace
+
+HeapObjectType HeapObjectRef::GetHeapObjectType() const {
+  if (data_->should_access_heap()) {
+    Map map = Handle<HeapObject>::cast(object())->map();
+    HeapObjectType::Flags flags(0);
+    if (map.is_undetectable()) flags |= HeapObjectType::kUndetectable;
+    if (map.is_callable()) flags |= HeapObjectType::kCallable;
+    return HeapObjectType(map.instance_type(), flags,
+                          GetOddballType(broker()->isolate(), map));
+  }
+  HeapObjectType::Flags flags(0);
+  if (map().is_undetectable()) flags |= HeapObjectType::kUndetectable;
+  if (map().is_callable()) flags |= HeapObjectType::kCallable;
+  return HeapObjectType(map().instance_type(), flags, map().oddball_type());
+}
+
+base::Optional<JSObjectRef> AllocationSiteRef::boilerplate() const {
+  if (data_->should_access_heap()) {
+    return TryMakeRef(broker(), object()->boilerplate(kAcquireLoad));
+  }
+  ObjectData* boilerplate = data()->AsAllocationSite()->boilerplate();
+  if (boilerplate) {
+    return JSObjectRef(broker(), boilerplate);
+  } else {
+    return base::nullopt;
+  }
+}
+
+ElementsKind JSObjectRef::GetElementsKind() const {
+  return map().elements_kind();
+}
+
+base::Optional<FixedArrayBaseRef> JSObjectRef::elements() const {
+  if (data_->should_access_heap()) {
+    return TryMakeRef(broker(), object()->elements());
+  }
+  const JSObjectData* d = data()->AsJSObject();
+  if (!d->serialized_elements()) {
+    TRACE(broker(), "'elements' on " << this);
+    return base::nullopt;
+  }
+  return FixedArrayBaseRef(broker(), d->elements());
+}
+
+int FixedArrayBaseRef::length() const {
+  IF_ACCESS_FROM_HEAP_C(length);
+  return data()->AsFixedArrayBase()->length();
+}
+
+PropertyDetails DescriptorArrayRef::GetPropertyDetails(
+    InternalIndex descriptor_index) const {
+  if (data_->should_access_heap()) {
+    return object()->GetDetails(descriptor_index);
+  }
+  return data()->AsDescriptorArray()->GetPropertyDetails(descriptor_index);
+}
+
+NameRef DescriptorArrayRef::GetPropertyKey(
+    InternalIndex descriptor_index) const {
+  if (data_->should_access_heap()) {
+    NameRef result = MakeRef(broker(), object()->GetKey(descriptor_index));
+    CHECK(result.IsUniqueName());
+    return result;
+  }
+  return NameRef(broker(),
+                 data()->AsDescriptorArray()->GetPropertyKey(descriptor_index));
+}
+
+ObjectRef DescriptorArrayRef::GetFieldType(
+    InternalIndex descriptor_index) const {
+  if (data_->should_access_heap()) {
+    return MakeRef<Object>(broker(), object()->GetFieldType(descriptor_index));
+  }
+  return ObjectRef(broker(),
+                   data()->AsDescriptorArray()->GetFieldType(descriptor_index));
+}
+
+base::Optional<ObjectRef> DescriptorArrayRef::GetStrongValue(
+    InternalIndex descriptor_index) const {
+  if (data_->should_access_heap()) {
+    HeapObject heap_object;
+    if (!object()
+             ->GetValue(descriptor_index)
+             .GetHeapObjectIfStrong(&heap_object)) {
+      return {};
+    }
+    // Since the descriptors in the descriptor array can be changed in-place
+    // via DescriptorArray::Replace, we might get a value that we haven't seen
+    // before.
+    return TryMakeRef(broker(), heap_object);
+  }
+  ObjectData* value =
+      data()->AsDescriptorArray()->GetStrongValue(descriptor_index);
+  if (!value) return base::nullopt;
+  return ObjectRef(broker(), value);
+}
+
+base::Optional<SharedFunctionInfoRef> FeedbackCellRef::shared_function_info()
+    const {
+  if (value()) {
+    FeedbackVectorRef vector = *value();
+    if (vector.serialized()) {
+      return vector.shared_function_info();
+    }
+  }
+  return base::nullopt;
+}
+
+void FeedbackVectorRef::Serialize() {
+  if (data_->should_access_heap()) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsFeedbackVector()->Serialize(broker());
+}
+
+bool FeedbackVectorRef::serialized() const {
+  if (data_->should_access_heap()) return true;
+  return data()->AsFeedbackVector()->serialized();
+}
+
+bool NameRef::IsUniqueName() const {
+  // Must match Name::IsUniqueName.
+  return IsInternalizedString() || IsSymbol();
+}
+
+void RegExpBoilerplateDescriptionRef::Serialize() {
+  if (data_->should_access_heap()) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  HeapObjectRef::data()->AsRegExpBoilerplateDescription()->Serialize(broker());
+}
+
+Handle<Object> ObjectRef::object() const {
+#ifdef DEBUG
+  if (broker()->mode() == JSHeapBroker::kSerialized &&
+      data_->used_status == ObjectData::Usage::kUnused) {
+    data_->used_status = ObjectData::Usage::kOnlyIdentityUsed;
+  }
+#endif  // DEBUG
+  return data_->object();
+}
+
+#ifdef DEBUG
+#define DEF_OBJECT_GETTER(T, ...)                                            \
+  Handle<T> T##Ref::object() const {                                         \
+    if (broker()->mode() == JSHeapBroker::kSerialized &&                     \
+        data_->used_status == ObjectData::Usage::kUnused) {                  \
+      data_->used_status = ObjectData::Usage::kOnlyIdentityUsed;             \
+    }                                                                        \
+    return Handle<T>(reinterpret_cast<Address*>(data_->object().address())); \
+  }
+#else
+#define DEF_OBJECT_GETTER(T, ...)                                            \
+  Handle<T> T##Ref::object() const {                                         \
+    return Handle<T>(reinterpret_cast<Address*>(data_->object().address())); \
+  }
+#endif  // DEBUG
+
+HEAP_BROKER_OBJECT_LIST(DEF_OBJECT_GETTER)
+#undef DEF_OBJECT_GETTER
+
+JSHeapBroker* ObjectRef::broker() const { return broker_; }
+
+ObjectData* ObjectRef::data() const {
+  switch (broker()->mode()) {
+    case JSHeapBroker::kDisabled:
+      CHECK_NE(data_->kind(), kSerializedHeapObject);
+      return data_;
+    case JSHeapBroker::kSerializing:
+      CHECK_NE(data_->kind(), kUnserializedHeapObject);
+      return data_;
+    case JSHeapBroker::kSerialized:
+#ifdef DEBUG
+      data_->used_status = ObjectData::Usage::kDataUsed;
+#endif  // DEBUG
+      CHECK_NE(data_->kind(), kUnserializedHeapObject);
+      return data_;
+    case JSHeapBroker::kRetired:
+      UNREACHABLE();
+  }
+}
+
+Reduction NoChangeBecauseOfMissingData(JSHeapBroker* broker,
+                                       const char* function, int line) {
+  TRACE_MISSING(broker, "data in function " << function << " at line " << line);
+  return AdvancedReducer::NoChange();
+}
+
+NativeContextData::NativeContextData(JSHeapBroker* broker, ObjectData** storage,
+                                     Handle<NativeContext> object)
+    : ContextData(broker, storage, object),
+      state_(State::kUnserialized),
+      function_maps_(broker->zone()) {}
+
+void NativeContextData::Serialize(JSHeapBroker* broker) {
+  if (state_ != State::kUnserialized) return;
+  state_ = State::kSerializedOnMainThread;
+
+  TraceScope tracer(broker, this, "NativeContextData::Serialize");
+  Handle<NativeContext> context = Handle<NativeContext>::cast(object());
+
+#define SERIALIZE_MEMBER(type, name)                                          \
+  DCHECK_NULL(name##_);                                                       \
+  name##_ = broker->GetOrCreateData(context->name());                         \
+  if (!name##_->should_access_heap()) {                                       \
+    if (name##_->IsMap() &&                                                   \
+        !InstanceTypeChecker::IsContext(name##_->AsMap()->instance_type())) { \
+      name##_->AsMap()->SerializeConstructor(broker);                         \
+    }                                                                         \
+    if (name##_->IsJSFunction()) {                                            \
+      name##_->AsJSFunction()->Serialize(broker);                             \
+    }                                                                         \
+  }
+  BROKER_COMPULSORY_NATIVE_CONTEXT_FIELDS(SERIALIZE_MEMBER)
+  if (!broker->is_isolate_bootstrapping()) {
+    BROKER_OPTIONAL_NATIVE_CONTEXT_FIELDS(SERIALIZE_MEMBER)
+  }
+#undef SERIALIZE_MEMBER
+
+  if (!bound_function_with_constructor_map_->should_access_heap()) {
+    bound_function_with_constructor_map_->AsMap()->SerializePrototype(broker);
+  }
+  if (!bound_function_without_constructor_map_->should_access_heap()) {
+    bound_function_without_constructor_map_->AsMap()->SerializePrototype(
+        broker);
+  }
+
+  scope_info_ = broker->GetOrCreateData(context->scope_info());
+}
+
+void NativeContextData::SerializeOnBackground(JSHeapBroker* broker) {
+  if (state_ == State::kFullySerialized) return;
+  DCHECK_EQ(state_, State::kSerializedOnMainThread);
+  state_ = State::kSerializedOnMainThread;
+
+  UnparkedScopeIfNeeded unparked_scope(broker);
+  TraceScope tracer(broker, this, "NativeContextData::SerializeOnBackground");
+  Handle<NativeContext> context = Handle<NativeContext>::cast(object());
+
+#define SERIALIZE_MEMBER(type, name)                             \
+  DCHECK_NULL(name##_);                                          \
+  name##_ = broker->GetOrCreateData(context->name(kAcquireLoad), \
+                                    kAssumeMemoryFence);         \
+  if (!name##_->should_access_heap()) {                          \
+    DCHECK(!name##_->IsJSFunction());                            \
+  }
+  BROKER_COMPULSORY_BACKGROUND_NATIVE_CONTEXT_FIELDS(SERIALIZE_MEMBER)
+  if (!broker->is_isolate_bootstrapping()) {
+    BROKER_OPTIONAL_BACKGROUND_NATIVE_CONTEXT_FIELDS(SERIALIZE_MEMBER)
+  }
+#undef SERIALIZE_MEMBER
+
+  DCHECK(function_maps_.empty());
+  int const first = Context::FIRST_FUNCTION_MAP_INDEX;
+  int const last = Context::LAST_FUNCTION_MAP_INDEX;
+  function_maps_.reserve(last + 1 - first);
+  for (int i = first; i <= last; ++i) {
+    function_maps_.push_back(broker->GetOrCreateData(
+        context->get(i, kAcquireLoad), kAssumeMemoryFence));
+  }
+}
+
+void JSFunctionRef::Serialize() {
+  if (data_->should_access_heap()) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsJSFunction()->Serialize(broker());
+}
+
+void JSFunctionRef::SerializeCodeAndFeedback() {
+  if (data_->should_access_heap()) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsJSFunction()->SerializeCodeAndFeedback(broker());
+}
+
+bool JSBoundFunctionRef::serialized() const {
+  if (data_->should_access_heap()) return true;
+  if (data_->AsJSBoundFunction()->serialized()) return true;
+  TRACE_BROKER_MISSING(broker(), "data for JSBoundFunction " << this);
+  return false;
+}
+
+bool JSFunctionRef::serialized() const {
+  if (data_->should_access_heap()) return true;
+  if (data_->AsJSFunction()->serialized()) return true;
+  TRACE_BROKER_MISSING(broker(), "data for JSFunction " << this);
+  return false;
+}
+
+bool JSFunctionRef::serialized_code_and_feedback() const {
+  if (data_->should_access_heap()) return true;
+  return data()->AsJSFunction()->serialized_code_and_feedback();
+}
+
+CodeRef JSFunctionRef::code() const {
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    return MakeRefAssumeMemoryFence(broker(), object()->code(kAcquireLoad));
+  }
+
+  return CodeRef(broker(), ObjectRef::data()->AsJSFunction()->code());
+}
+
+void SharedFunctionInfoRef::SerializeFunctionTemplateInfo() {
+  if (data_->should_access_heap()) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsSharedFunctionInfo()->SerializeFunctionTemplateInfo(broker());
+}
+
+void SharedFunctionInfoRef::SerializeScopeInfoChain() {
+  if (data_->should_access_heap()) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsSharedFunctionInfo()->SerializeScopeInfoChain(broker());
+}
+
+base::Optional<FunctionTemplateInfoRef>
+SharedFunctionInfoRef::function_template_info() const {
+  if (data_->should_access_heap()) {
+    if (!object()->IsApiFunction()) return {};
+    return TryMakeRef(broker(), FunctionTemplateInfo::cast(
+                                    object()->function_data(kAcquireLoad)));
+  }
+  ObjectData* function_template_info =
+      data()->AsSharedFunctionInfo()->function_template_info();
+  if (!function_template_info) return base::nullopt;
+  return FunctionTemplateInfoRef(broker(), function_template_info);
+}
+
+int SharedFunctionInfoRef::context_header_size() const {
+  IF_ACCESS_FROM_HEAP_C(scope_info().ContextHeaderLength);
+  return data()->AsSharedFunctionInfo()->context_header_size();
+}
+
+ScopeInfoRef SharedFunctionInfoRef::scope_info() const {
+  if (data_->should_access_heap()) {
+    return MakeRef(broker(), object()->scope_info());
+  }
+  return ScopeInfoRef(broker(), data()->AsSharedFunctionInfo()->scope_info());
+}
+
+void JSObjectRef::SerializeObjectCreateMap() {
+  if (data_->should_access_heap()) return;
+  CHECK_IMPLIES(!FLAG_turbo_concurrent_get_property_access_info,
+                broker()->mode() == JSHeapBroker::kSerializing);
+  data()->AsJSObject()->SerializeObjectCreateMap(broker());
+}
+
+bool MapRef::TrySerializeOwnDescriptor(InternalIndex descriptor_index) {
+  CHECK_LT(descriptor_index.as_int(), NumberOfOwnDescriptors());
+  if (data_->should_access_heap()) return true;
+  CHECK_IMPLIES(!FLAG_turbo_concurrent_get_property_access_info,
+                broker()->mode() == JSHeapBroker::kSerializing);
+  return data()->AsMap()->TrySerializeOwnDescriptor(broker(), descriptor_index);
+}
+
+void MapRef::SerializeOwnDescriptor(InternalIndex descriptor_index) {
+  CHECK(TrySerializeOwnDescriptor(descriptor_index));
+}
+
+bool MapRef::serialized_own_descriptor(InternalIndex descriptor_index) const {
+  CHECK_LT(descriptor_index.as_int(), NumberOfOwnDescriptors());
+  if (data_->should_access_heap()) return true;
+  ObjectData* maybe_desc_array_data = data()->AsMap()->instance_descriptors();
+  if (!maybe_desc_array_data) return false;
+  if (maybe_desc_array_data->should_access_heap()) return true;
+  DescriptorArrayData* desc_array_data =
+      maybe_desc_array_data->AsDescriptorArray();
+  return desc_array_data->serialized_descriptor(descriptor_index);
+}
+
+void MapRef::SerializeBackPointer() {
+  if (data_->should_access_heap()) return;
+  CHECK_IMPLIES(!FLAG_turbo_concurrent_get_property_access_info,
+                broker()->mode() == JSHeapBroker::kSerializing);
+  data()->AsMap()->SerializeBackPointer(broker());
+}
+
+bool MapRef::TrySerializePrototype() {
+  if (data_->should_access_heap()) return true;
+  CHECK_IMPLIES(!FLAG_turbo_concurrent_get_property_access_info,
+                broker()->mode() == JSHeapBroker::kSerializing);
+  return data()->AsMap()->TrySerializePrototype(broker());
+}
+
+void MapRef::SerializePrototype() { CHECK(TrySerializePrototype()); }
+
+void SourceTextModuleRef::Serialize() {
+  if (data_->should_access_heap()) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsSourceTextModule()->Serialize(broker());
+}
+
+void NativeContextRef::Serialize() {
+  if (data_->should_access_heap()) return;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsNativeContext()->Serialize(broker());
+}
+
+void NativeContextRef::SerializeOnBackground() {
+  if (data_->should_access_heap()) return;
+  CHECK(broker()->mode() == JSHeapBroker::kSerializing ||
+        broker()->mode() == JSHeapBroker::kSerialized);
+  data()->AsNativeContext()->SerializeOnBackground(broker());
+}
+
+void JSTypedArrayRef::Serialize() {
+  if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
+    // Even if the typed array object itself is no longer serialized (besides
+    // the JSObject parts), the `buffer` field still is and thus we need to
+    // make sure to visit it.
+    // TODO(jgruber,v8:7790): Remove once JSObject is no longer serialized.
+    static_assert(
+        std::is_base_of<JSObject, decltype(object()->buffer())>::value, "");
+    STATIC_ASSERT(IsSerializedRef<JSObject>());
+    MakeRef<JSObject>(broker(), object()->buffer());
+  } else {
+    CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+    data()->AsJSTypedArray()->Serialize(broker());
+  }
+}
+
+bool JSTypedArrayRef::serialized() const {
+  if (data_->should_access_heap()) return true;
+  if (broker()->is_concurrent_inlining()) return true;
+  if (data_->AsJSTypedArray()->serialized()) return true;
+  TRACE_BROKER_MISSING(broker(), "data for JSTypedArray " << this);
+  return false;
+}
+
+bool JSBoundFunctionRef::Serialize() {
+  if (data_->should_access_heap()) return true;
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  return data()->AsJSBoundFunction()->Serialize(broker());
+}
+
+bool PropertyCellRef::Serialize() const {
+  if (data_->should_access_heap()) return true;
+  CHECK(broker()->mode() == JSHeapBroker::kSerializing ||
+        broker()->mode() == JSHeapBroker::kSerialized);
+  return data()->AsPropertyCell()->Serialize(broker());
+}
+
+void FunctionTemplateInfoRef::SerializeCallCode() {
+  if (data_->should_access_heap()) {
+    CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+    // CallHandlerInfo::data may still hold a serialized heap object, so we
+    // have to make the broker aware of it.
+    // TODO(v8:7790): Remove this case once ObjectRef is never serialized.
+    Handle<HeapObject> call_code(object()->call_code(kAcquireLoad),
+                                 broker()->isolate());
+    if (call_code->IsCallHandlerInfo()) {
+      broker()->GetOrCreateData(
+          Handle<CallHandlerInfo>::cast(call_code)->data());
+    }
+    return;
+  }
+  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
+  data()->AsFunctionTemplateInfo()->SerializeCallCode(broker());
+}
+
+base::Optional<PropertyCellRef> JSGlobalObjectRef::GetPropertyCell(
+    NameRef const& name, SerializationPolicy policy) const {
+  if (data_->should_access_heap()) {
+    return GetPropertyCellFromHeap(broker(), name.object());
+  }
+  ObjectData* property_cell_data = data()->AsJSGlobalObject()->GetPropertyCell(
+      broker(), name.data(), policy);
+  if (property_cell_data == nullptr) return base::nullopt;
+  return PropertyCellRef(broker(), property_cell_data);
+}
+
+std::ostream& operator<<(std::ostream& os, const ObjectRef& ref) {
+  if (!FLAG_concurrent_recompilation) {
+    // We cannot be in a background thread so it's safe to read the heap.
+    AllowHandleDereference allow_handle_dereference;
+    return os << ref.data() << " {" << ref.object() << "}";
+  } else if (ref.data_->should_access_heap()) {
+    return os << ref.data() << " {" << ref.object() << "}";
+  } else {
+    return os << ref.data();
+  }
+}
+
+unsigned CodeRef::GetInlinedBytecodeSize() const {
+  if (data_->should_access_heap()) {
+    unsigned value = object()->inlined_bytecode_size();
+    if (value > 0) {
+      // Don't report inlined bytecode size if the code object was already
+      // deoptimized.
+      value = object()->marked_for_deoptimization() ? 0 : value;
+    }
+    return value;
+  }
+
+  return ObjectRef::data()->AsCode()->inlined_bytecode_size();
+}
+
+#undef BIMODAL_ACCESSOR
+#undef BIMODAL_ACCESSOR_B
+#undef BIMODAL_ACCESSOR_C
+#undef IF_ACCESS_FROM_HEAP
+#undef IF_ACCESS_FROM_HEAP_C
+#undef TRACE
+#undef TRACE_MISSING
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8
diff --git a/chromium/v8/src/compiler/heap-refs.h b/chromium/v8/src/compiler/heap-refs.h
index 9d125537661..d1f40bbedfd 100644
--- a/chromium/v8/src/compiler/heap-refs.h
+++ b/chromium/v8/src/compiler/heap-refs.h
@@ -40,6 +40,13 @@ struct WasmModule;
 
 namespace compiler {
 
+class CompilationDependencies;
+struct FeedbackSource;
+class JSHeapBroker;
+class ObjectData;
+class PerIsolateCompilerCache;
+class PropertyAccessInfo;
+
 // Whether we are loading a property or storing to a property.
 // For a store during literal creation, do not walk up the prototype chain.
 enum class AccessMode { kLoad, kStore, kStoreInLiteral, kHas };
@@ -60,111 +67,100 @@ enum class OddballType : uint8_t {
   kOther  // Oddball, but none of the above.
 };
 
-// This list is sorted such that subtypes appear before their supertypes.
-// This list must not contain a type if it doesn't contain all of its subtypes
-// too. For example, it CANNOT contain FixedArrayBase if it doesn't contain
-// FixedDoubleArray, BytecodeArray and FixedArray.
-// DO NOT VIOLATE THESE TWO PROPERTIES!
-// Classes on this list will skip serialization when
-// FLAG_turbo_direct_heap_access is on. Otherwise, they might get serialized.
-#define HEAP_BROKER_NEVER_SERIALIZED_OBJECT_LIST(V) \
-  /* Subtypes of FixedArray */                      \
-  V(ObjectBoilerplateDescription)                   \
-  V(ScopeInfo)                                      \
-  /* Subtypes of String */                          \
-  V(InternalizedString)                             \
-  /* Subtypes of FixedArrayBase */                  \
-  V(BytecodeArray)                                  \
-  /* Subtypes of Name */                            \
-  V(String)                                         \
-  V(Symbol)                                         \
-  /* Subtypes of HeapObject */                      \
-  V(AccessorInfo)                                   \
-  V(ArrayBoilerplateDescription)                    \
-  V(CallHandlerInfo)                                \
-  V(Cell)                                           \
-  V(Code)                                           \
-  V(DescriptorArray)                                \
-  V(FeedbackCell)                                   \
-  V(FeedbackVector)                                 \
-  V(FunctionTemplateInfo)                           \
-  V(Name)                                           \
-  V(RegExpBoilerplateDescription)                   \
-  V(SharedFunctionInfo)                             \
-  V(TemplateObjectDescription)
+enum class RefSerializationKind {
+  // Will skip serialization when --concurrent-inlining is on. Otherwise, they
+  // might get serialized. (The cake is a lie.)
+  kNeverSerialized,
+  // Can be serialized on demand from the background thread.
+  kBackgroundSerialized,
+  kSerialized,
+};
 
 // This list is sorted such that subtypes appear before their supertypes.
 // DO NOT VIOLATE THIS PROPERTY!
-// Classes in this list behave like serialized classes, but they allow lazy
-// serialization from background threads where this is safe (e.g. for objects
-// that are immutable and fully initialized once visible). Pass
-// ObjectRef::BackgroundSerialization::kAllowed to the ObjectRef constructor
-// for objects where serialization from the background thread is safe.
-#define HEAP_BROKER_POSSIBLY_BACKGROUND_SERIALIZED_OBJECT_LIST(V) \
-  /* Subtypes of HeapObject */                                    \
-  V(BigInt)                                                       \
-  V(HeapNumber)                                                   \
-  V(Map)
+#define HEAP_BROKER_OBJECT_LIST(V)                                        \
+  /* Subtypes of JSObject */                                              \
+  V(JSArray, RefSerializationKind::kSerialized)                           \
+  V(JSBoundFunction, RefSerializationKind::kSerialized)                   \
+  V(JSDataView, RefSerializationKind::kSerialized)                        \
+  V(JSFunction, RefSerializationKind::kSerialized)                        \
+  V(JSGlobalObject, RefSerializationKind::kSerialized)                    \
+  V(JSGlobalProxy, RefSerializationKind::kSerialized)                     \
+  V(JSTypedArray, RefSerializationKind::kSerialized)                      \
+  /* Subtypes of Context */                                               \
+  V(NativeContext, RefSerializationKind::kSerialized)                     \
+  /* Subtypes of FixedArray */                                            \
+  V(ObjectBoilerplateDescription, RefSerializationKind::kNeverSerialized) \
+  V(ScriptContextTable, RefSerializationKind::kBackgroundSerialized)      \
+  /* Subtypes of String */                                                \
+  V(InternalizedString, RefSerializationKind::kNeverSerialized)           \
+  /* Subtypes of FixedArrayBase */                                        \
+  V(BytecodeArray, RefSerializationKind::kNeverSerialized)                \
+  V(FixedArray, RefSerializationKind::kBackgroundSerialized)              \
+  V(FixedDoubleArray, RefSerializationKind::kNeverSerialized)             \
+  /* Subtypes of Name */                                                  \
+  V(String, RefSerializationKind::kNeverSerialized)                       \
+  V(Symbol, RefSerializationKind::kNeverSerialized)                       \
+  /* Subtypes of JSReceiver */                                            \
+  V(JSObject, RefSerializationKind::kSerialized)                          \
+  /* Subtypes of HeapObject */                                            \
+  V(AccessorInfo, RefSerializationKind::kNeverSerialized)                 \
+  V(AllocationSite, RefSerializationKind::kSerialized)                    \
+  V(ArrayBoilerplateDescription, RefSerializationKind::kNeverSerialized)  \
+  V(BigInt, RefSerializationKind::kBackgroundSerialized)                  \
+  V(CallHandlerInfo, RefSerializationKind::kNeverSerialized)              \
+  V(Cell, RefSerializationKind::kNeverSerialized)                         \
+  V(Code, RefSerializationKind::kNeverSerialized)                         \
+  V(Context, RefSerializationKind::kSerialized)                           \
+  V(DescriptorArray, RefSerializationKind::kNeverSerialized)              \
+  V(FeedbackCell, RefSerializationKind::kNeverSerialized)                 \
+  V(FeedbackVector, RefSerializationKind::kNeverSerialized)               \
+  V(FixedArrayBase, RefSerializationKind::kBackgroundSerialized)          \
+  V(FunctionTemplateInfo, RefSerializationKind::kNeverSerialized)         \
+  V(HeapNumber, RefSerializationKind::kNeverSerialized)                   \
+  V(JSReceiver, RefSerializationKind::kBackgroundSerialized)              \
+  V(Map, RefSerializationKind::kBackgroundSerialized)                     \
+  V(Name, RefSerializationKind::kNeverSerialized)                         \
+  V(PropertyCell, RefSerializationKind::kBackgroundSerialized)            \
+  V(RegExpBoilerplateDescription, RefSerializationKind::kNeverSerialized) \
+  V(ScopeInfo, RefSerializationKind::kNeverSerialized)                    \
+  V(SharedFunctionInfo, RefSerializationKind::kNeverSerialized)           \
+  V(SourceTextModule, RefSerializationKind::kNeverSerialized)             \
+  V(TemplateObjectDescription, RefSerializationKind::kNeverSerialized)    \
+  /* Subtypes of Object */                                                \
+  V(HeapObject, RefSerializationKind::kBackgroundSerialized)
+
+#define FORWARD_DECL(Name, ...) class Name##Ref;
+HEAP_BROKER_OBJECT_LIST(FORWARD_DECL)
+#undef FORWARD_DECL
 
-// This list is sorted such that subtypes appear before their supertypes.
-// DO NOT VIOLATE THIS PROPERTY!
-// Types in this list can be serialized on demand from the background thread.
-#define HEAP_BROKER_BACKGROUND_SERIALIZED_OBJECT_LIST(V) \
-  /* Subtypes of HeapObject */                           \
-  V(PropertyCell)
+class ObjectRef;
 
-// This list is sorted such that subtypes appear before their supertypes.
-// DO NOT VIOLATE THIS PROPERTY!
-#define HEAP_BROKER_SERIALIZED_OBJECT_LIST(V) \
-  /* Subtypes of JSObject */                  \
-  V(JSArray)                                  \
-  V(JSBoundFunction)                          \
-  V(JSDataView)                               \
-  V(JSFunction)                               \
-  V(JSGlobalObject)                           \
-  V(JSGlobalProxy)                            \
-  V(JSTypedArray)                             \
-  /* Subtypes of Context */                   \
-  V(NativeContext)                            \
-  /* Subtypes of FixedArray */                \
-  V(Context)                                  \
-  V(ScriptContextTable)                       \
-  /* Subtypes of FixedArrayBase */            \
-  V(FixedArray)                               \
-  V(FixedDoubleArray)                         \
-  /* Subtypes of JSReceiver */                \
-  V(JSObject)                                 \
-  /* Subtypes of HeapObject */                \
-  V(AllocationSite)                           \
-  V(FixedArrayBase)                           \
-  V(JSReceiver)                               \
-  V(SourceTextModule)                         \
-  /* Subtypes of Object */                    \
-  V(HeapObject)
+template <class T>
+struct ref_traits;
 
-class CompilationDependencies;
-struct FeedbackSource;
-class JSHeapBroker;
-class ObjectData;
-class PerIsolateCompilerCache;
-class PropertyAccessInfo;
-#define FORWARD_DECL(Name) class Name##Ref;
-HEAP_BROKER_SERIALIZED_OBJECT_LIST(FORWARD_DECL)
-HEAP_BROKER_POSSIBLY_BACKGROUND_SERIALIZED_OBJECT_LIST(FORWARD_DECL)
-HEAP_BROKER_BACKGROUND_SERIALIZED_OBJECT_LIST(FORWARD_DECL)
-HEAP_BROKER_NEVER_SERIALIZED_OBJECT_LIST(FORWARD_DECL)
-#undef FORWARD_DECL
+#define REF_TRAITS(Name, Kind)                                           \
+  template <>                                                            \
+  struct ref_traits<Name> {                                              \
+    using ref_type = Name##Ref;                                          \
+    static constexpr RefSerializationKind ref_serialization_kind = Kind; \
+  };
+HEAP_BROKER_OBJECT_LIST(REF_TRAITS)
+#undef REF_TYPE
+
+template <>
+struct ref_traits<Object> {
+  using ref_type = ObjectRef;
+  // Note: While a bit awkward, this artificial ref serialization kind value is
+  // okay: smis are never-serialized, and we never create raw non-smi
+  // ObjectRefs (they would at least be HeapObjectRefs instead).
+  static constexpr RefSerializationKind ref_serialization_kind =
+      RefSerializationKind::kNeverSerialized;
+};
 
 class V8_EXPORT_PRIVATE ObjectRef {
  public:
-  enum class BackgroundSerialization {
-    kDisallowed,
-    kAllowed,
-  };
-
   ObjectRef(JSHeapBroker* broker, Handle<Object> object,
-            BackgroundSerialization background_serialization =
-                BackgroundSerialization::kDisallowed,
             bool check_type = true);
   ObjectRef(JSHeapBroker* broker, ObjectData* data, bool check_type = true)
       : data_(data), broker_(broker) {
@@ -178,25 +174,19 @@ class V8_EXPORT_PRIVATE ObjectRef {
   bool IsSmi() const;
   int AsSmi() const;
 
-#define HEAP_IS_METHOD_DECL(Name) bool Is##Name() const;
-  HEAP_BROKER_SERIALIZED_OBJECT_LIST(HEAP_IS_METHOD_DECL)
-  HEAP_BROKER_POSSIBLY_BACKGROUND_SERIALIZED_OBJECT_LIST(HEAP_IS_METHOD_DECL)
-  HEAP_BROKER_BACKGROUND_SERIALIZED_OBJECT_LIST(HEAP_IS_METHOD_DECL)
-  HEAP_BROKER_NEVER_SERIALIZED_OBJECT_LIST(HEAP_IS_METHOD_DECL)
+#define HEAP_IS_METHOD_DECL(Name, ...) bool Is##Name() const;
+  HEAP_BROKER_OBJECT_LIST(HEAP_IS_METHOD_DECL)
 #undef HEAP_IS_METHOD_DECL
 
-#define HEAP_AS_METHOD_DECL(Name) Name##Ref As##Name() const;
-  HEAP_BROKER_SERIALIZED_OBJECT_LIST(HEAP_AS_METHOD_DECL)
-  HEAP_BROKER_POSSIBLY_BACKGROUND_SERIALIZED_OBJECT_LIST(HEAP_AS_METHOD_DECL)
-  HEAP_BROKER_BACKGROUND_SERIALIZED_OBJECT_LIST(HEAP_AS_METHOD_DECL)
-  HEAP_BROKER_NEVER_SERIALIZED_OBJECT_LIST(HEAP_AS_METHOD_DECL)
+#define HEAP_AS_METHOD_DECL(Name, ...) Name##Ref As##Name() const;
+  HEAP_BROKER_OBJECT_LIST(HEAP_AS_METHOD_DECL)
 #undef HEAP_AS_METHOD_DECL
 
   bool IsNull() const;
   bool IsNullOrUndefined() const;
   bool IsTheHole() const;
 
-  bool BooleanValue() const;
+  base::Optional<bool> TryGetBooleanValue() const;
   Maybe<double> OddballToNumber() const;
 
   Isolate* isolate() const;
@@ -272,20 +262,11 @@ class HeapObjectType {
 
 // Constructors are carefully defined such that we do a type check on
 // the outermost Ref class in the inheritance chain only.
-#define DEFINE_REF_CONSTRUCTOR(name, base)                                  \
-  name##Ref(JSHeapBroker* broker, Handle<Object> object,                    \
-            BackgroundSerialization background_serialization =              \
-                BackgroundSerialization::kDisallowed,                       \
-            bool check_type = true)                                         \
-      : base(broker, object, background_serialization, false) {             \
+#define DEFINE_REF_CONSTRUCTOR(Name, Base)                                  \
+  Name##Ref(JSHeapBroker* broker, ObjectData* data, bool check_type = true) \
+      : Base(broker, data, false) {                                         \
     if (check_type) {                                                       \
-      CHECK(Is##name());                                                    \
-    }                                                                       \
-  }                                                                         \
-  name##Ref(JSHeapBroker* broker, ObjectData* data, bool check_type = true) \
-      : base(broker, data, false) {                                         \
-    if (check_type) {                                                       \
-      CHECK(Is##name());                                                    \
+      CHECK(Is##Name());                                                    \
     }                                                                       \
   }
 
@@ -435,6 +416,11 @@ class RegExpBoilerplateDescriptionRef : public HeapObjectRef {
   int flags() const;
 };
 
+// HeapNumberRef is only created for immutable HeapNumbers. Mutable
+// HeapNumbers (those owned by in-object or backing store fields with
+// representation type Double are not exposed to the compiler through
+// HeapNumberRef. Instead, we read their value, and protect that read
+// with a field-constness Dependency.
 class HeapNumberRef : public HeapObjectRef {
  public:
   DEFINE_REF_CONSTRUCTOR(HeapNumber, HeapObjectRef)
@@ -451,9 +437,9 @@ class ContextRef : public HeapObjectRef {
   Handle<Context> object() const;
 
   // {previous} decrements {depth} by 1 for each previous link successfully
-  // followed. If {depth} != 0 on function return, then it only got
-  // partway to the desired depth. If {serialize} is true, then
-  // {previous} will cache its findings.
+  // followed. If {depth} != 0 on function return, then it only got partway to
+  // the desired depth. If {serialize} is true, then {previous} will cache its
+  // findings (unless concurrent inlining is enabled).
   ContextRef previous(size_t* depth,
                       SerializationPolicy policy =
                           SerializationPolicy::kAssumeSerialized) const;
@@ -464,15 +450,14 @@ class ContextRef : public HeapObjectRef {
                      SerializationPolicy::kAssumeSerialized) const;
 
   SourceTextModuleRef GetModule(SerializationPolicy policy) const;
-
-  // We only serialize the ScopeInfo if certain Promise
-  // builtins are called.
-  void SerializeScopeInfo();
-  base::Optional<ScopeInfoRef> scope_info() const;
 };
 
+// TODO(jgruber): Don't serialize NativeContext fields once all refs can be
+// created concurrently.
+
 #define BROKER_COMPULSORY_NATIVE_CONTEXT_FIELDS(V) \
   V(JSFunction, array_function)                    \
+  V(JSFunction, function_prototype_apply)          \
   V(JSFunction, boolean_function)                  \
   V(JSFunction, bigint_function)                   \
   V(JSFunction, number_function)                   \
@@ -532,6 +517,8 @@ class NativeContextRef : public ContextRef {
  public:
   DEFINE_REF_CONSTRUCTOR(NativeContext, ContextRef)
 
+  bool is_unserialized_heap_object() const;
+
   Handle<NativeContext> object() const;
 
   void Serialize();
@@ -556,13 +543,6 @@ class NameRef : public HeapObjectRef {
   bool IsUniqueName() const;
 };
 
-class ScriptContextTableRef : public HeapObjectRef {
- public:
-  DEFINE_REF_CONSTRUCTOR(ScriptContextTable, HeapObjectRef)
-
-  Handle<ScriptContextTable> object() const;
-};
-
 class DescriptorArrayRef : public HeapObjectRef {
  public:
   DEFINE_REF_CONSTRUCTOR(DescriptorArray, HeapObjectRef)
@@ -701,8 +681,11 @@ class V8_EXPORT_PRIVATE MapRef : public HeapObjectRef {
   HeapObjectRef GetBackPointer() const;
 
   void SerializePrototype();
-  bool serialized_prototype() const;
-  HeapObjectRef prototype() const;
+  // TODO(neis): We should be able to remove TrySerializePrototype once
+  // concurrent-inlining is always on. Then we can also change the return type
+  // of prototype() back to HeapObjectRef.
+  bool TrySerializePrototype();
+  base::Optional<HeapObjectRef> prototype() const;
 
   void SerializeForElementLoad();
 
@@ -711,6 +694,7 @@ class V8_EXPORT_PRIVATE MapRef : public HeapObjectRef {
       ZoneVector<MapRef>* prototype_maps);
 
   // Concerning the underlying instance_descriptors:
+  bool TrySerializeOwnDescriptor(InternalIndex descriptor_index);
   void SerializeOwnDescriptor(InternalIndex descriptor_index);
   bool serialized_own_descriptor(InternalIndex descriptor_index) const;
   MapRef FindFieldOwner(InternalIndex descriptor_index) const;
@@ -754,8 +738,8 @@ class FunctionTemplateInfoRef : public HeapObjectRef {
 
   void SerializeCallCode();
   base::Optional<CallHandlerInfoRef> call_code() const;
-  Address c_function() const;
-  const CFunctionInfo* c_signature() const;
+  ZoneVector<Address> c_functions() const;
+  ZoneVector<const CFunctionInfo*> c_signatures() const;
 
   HolderLookupResult LookupHolderOfExpectedType(
       MapRef receiver_map,
@@ -779,14 +763,6 @@ class ArrayBoilerplateDescriptionRef : public HeapObjectRef {
   int constants_elements_length() const;
 };
 
-class ObjectBoilerplateDescriptionRef : public HeapObjectRef {
- public:
-  using HeapObjectRef::HeapObjectRef;
-  Handle<ObjectBoilerplateDescription> object() const;
-
-  int size() const;
-};
-
 class FixedArrayRef : public FixedArrayBaseRef {
  public:
   DEFINE_REF_CONSTRUCTOR(FixedArray, FixedArrayBaseRef)
@@ -794,6 +770,12 @@ class FixedArrayRef : public FixedArrayBaseRef {
   Handle<FixedArray> object() const;
 
   ObjectRef get(int i) const;
+
+  // As above but may fail if Ref construction is not possible (e.g. for
+  // serialized types on the background thread).
+  // TODO(jgruber): Remove once all Ref types are never-serialized or
+  // background-serialized and can thus be created on background threads.
+  base::Optional<ObjectRef> TryGet(int i) const;
 };
 
 class FixedDoubleArrayRef : public FixedArrayBaseRef {
@@ -802,7 +784,10 @@ class FixedDoubleArrayRef : public FixedArrayBaseRef {
 
   Handle<FixedDoubleArray> object() const;
 
-  Float64 get(int i) const;
+  // Due to 64-bit unaligned reads, only usable for
+  // immutable-after-initialization FixedDoubleArrays protected by
+  // acquire-release semantics (such as boilerplate elements).
+  Float64 GetFromImmutableFixedDoubleArray(int i) const;
 };
 
 class BytecodeArrayRef : public FixedArrayBaseRef {
@@ -826,6 +811,22 @@ class BytecodeArrayRef : public FixedArrayBaseRef {
   int handler_table_size() const;
 };
 
+class ScriptContextTableRef : public FixedArrayRef {
+ public:
+  DEFINE_REF_CONSTRUCTOR(ScriptContextTable, FixedArrayRef)
+
+  Handle<ScriptContextTable> object() const;
+};
+
+class ObjectBoilerplateDescriptionRef : public FixedArrayRef {
+ public:
+  DEFINE_REF_CONSTRUCTOR(ObjectBoilerplateDescription, FixedArrayRef)
+
+  Handle<ObjectBoilerplateDescription> object() const;
+
+  int size() const;
+};
+
 class JSArrayRef : public JSObjectRef {
  public:
   DEFINE_REF_CONSTRUCTOR(JSArray, JSObjectRef)
@@ -965,7 +966,7 @@ class SourceTextModuleRef : public HeapObjectRef {
   void Serialize();
 
   base::Optional<CellRef> GetCell(int cell_index) const;
-  ObjectRef import_meta() const;
+  base::Optional<ObjectRef> import_meta() const;
 };
 
 class TemplateObjectDescriptionRef : public HeapObjectRef {
diff --git a/chromium/v8/src/compiler/int64-lowering.cc b/chromium/v8/src/compiler/int64-lowering.cc
index 706cd7de509..28eb30969c7 100644
--- a/chromium/v8/src/compiler/int64-lowering.cc
+++ b/chromium/v8/src/compiler/int64-lowering.cc
@@ -392,8 +392,7 @@ void Int64Lowering::LowerNode(Node* node) {
             if (call_descriptor->GetReturnType(old_index).representation() ==
                 MachineRepresentation::kWord64) {
               Node* high_node = graph()->NewNode(
-                  common()->Projection(new_index + 1), node,
-                  graph()->start());
+                  common()->Projection(new_index + 1), node, graph()->start());
               ReplaceNode(use_node, use_node, high_node);
               ++new_index;
             }
@@ -684,11 +683,11 @@ void Int64Lowering::LowerNode(Node* node) {
       ReplaceNode(node, low_node, high_node);
       break;
     }
-    case IrOpcode::kWord64Rol:
+    case IrOpcode::kWord64RolLowerable:
       DCHECK(machine()->Word32Rol().IsSupported());
       V8_FALLTHROUGH;
-    case IrOpcode::kWord64Ror: {
-      DCHECK_EQ(2, node->InputCount());
+    case IrOpcode::kWord64RorLowerable: {
+      DCHECK_EQ(3, node->InputCount());
       Node* input = node->InputAt(0);
       Node* shift = HasReplacementLow(node->InputAt(1))
                         ? GetReplacementLow(node->InputAt(1))
@@ -721,7 +720,7 @@ void Int64Lowering::LowerNode(Node* node) {
 
           auto* op1 = machine()->Word32Shr();
           auto* op2 = machine()->Word32Shl();
-          bool is_ror = node->opcode() == IrOpcode::kWord64Ror;
+          bool is_ror = node->opcode() == IrOpcode::kWord64RorLowerable;
           if (!is_ror) std::swap(op1, op2);
 
           Node* low_node =
@@ -742,7 +741,7 @@ void Int64Lowering::LowerNode(Node* node) {
                                graph()->NewNode(common()->Int32Constant(0x1F)));
         }
 
-        bool is_ror = node->opcode() == IrOpcode::kWord64Ror;
+        bool is_ror = node->opcode() == IrOpcode::kWord64RorLowerable;
         Node* inv_mask =
             is_ror ? graph()->NewNode(
                          machine()->Word32Xor(),
@@ -774,6 +773,7 @@ void Int64Lowering::LowerNode(Node* node) {
             graph(), common(),
             graph()->NewNode(machine()->Int32LessThan(), masked_shift6,
                              graph()->NewNode(common()->Int32Constant(32))));
+        lt32.Chain(NodeProperties::GetControlInput(node));
 
         // The low word and the high word can be swapped either at the input or
         // at the output. We swap the inputs so that shift does not have to be
@@ -807,13 +807,14 @@ void Int64Lowering::LowerNode(Node* node) {
       }
       break;
     }
-    case IrOpcode::kWord64Clz: {
-      DCHECK_EQ(1, node->InputCount());
+    case IrOpcode::kWord64ClzLowerable: {
+      DCHECK_EQ(2, node->InputCount());
       Node* input = node->InputAt(0);
       Diamond d(
           graph(), common(),
           graph()->NewNode(machine()->Word32Equal(), GetReplacementHigh(input),
                            graph()->NewNode(common()->Int32Constant(0))));
+      d.Chain(NodeProperties::GetControlInput(node));
 
       Node* low_node = d.Phi(
           MachineRepresentation::kWord32,
@@ -825,14 +826,16 @@ void Int64Lowering::LowerNode(Node* node) {
       ReplaceNode(node, low_node, graph()->NewNode(common()->Int32Constant(0)));
       break;
     }
-    case IrOpcode::kWord64Ctz: {
-      DCHECK_EQ(1, node->InputCount());
+    case IrOpcode::kWord64CtzLowerable: {
+      DCHECK_EQ(2, node->InputCount());
       DCHECK(machine()->Word32Ctz().IsSupported());
       Node* input = node->InputAt(0);
       Diamond d(
           graph(), common(),
           graph()->NewNode(machine()->Word32Equal(), GetReplacementLow(input),
                            graph()->NewNode(common()->Int32Constant(0))));
+      d.Chain(NodeProperties::GetControlInput(node));
+
       Node* low_node =
           d.Phi(MachineRepresentation::kWord32,
                 graph()->NewNode(machine()->Int32Add(),
@@ -844,6 +847,12 @@ void Int64Lowering::LowerNode(Node* node) {
       ReplaceNode(node, low_node, graph()->NewNode(common()->Int32Constant(0)));
       break;
     }
+    case IrOpcode::kWord64Ror:
+    case IrOpcode::kWord64Rol:
+    case IrOpcode::kWord64Ctz:
+    case IrOpcode::kWord64Clz:
+      FATAL("%s operator should not be used in 32-bit systems",
+            node->op()->mnemonic());
     case IrOpcode::kWord64Popcnt: {
       DCHECK_EQ(1, node->InputCount());
       Node* input = node->InputAt(0);
@@ -1030,7 +1039,7 @@ void Int64Lowering::LowerNode(Node* node) {
 
     default: { DefaultLowering(node); }
   }
-}  // NOLINT(readability/fn_size)
+}
 
 void Int64Lowering::LowerComparison(Node* node, const Operator* high_word_op,
                                     const Operator* low_word_op) {
diff --git a/chromium/v8/src/compiler/js-call-reducer.cc b/chromium/v8/src/compiler/js-call-reducer.cc
index bb7a11d16dc..3e33d0694e5 100644
--- a/chromium/v8/src/compiler/js-call-reducer.cc
+++ b/chromium/v8/src/compiler/js-call-reducer.cc
@@ -15,6 +15,7 @@
 #include "src/codegen/tnode.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/access-info.h"
+#include "src/compiler/allocation-builder-inl.h"
 #include "src/compiler/allocation-builder.h"
 #include "src/compiler/compilation-dependencies.h"
 #include "src/compiler/feedback-source.h"
@@ -42,7 +43,7 @@ namespace internal {
 namespace compiler {
 
 // Shorter lambda declarations with less visual clutter.
-#define _ [&]()  // NOLINT(whitespace/braces)
+#define _ [&]()
 
 class JSCallReducerAssembler : public JSGraphAssembler {
  protected:
@@ -889,8 +890,8 @@ class FastApiCallReducerAssembler : public JSCallReducerAssembler {
       Node* holder, const SharedFunctionInfoRef shared, Node* target,
       const int arity, Node* effect)
       : JSCallReducerAssembler(reducer, node),
-        c_function_(function_template_info.c_function()),
-        c_signature_(function_template_info.c_signature()),
+        c_functions_(function_template_info.c_functions()),
+        c_signatures_(function_template_info.c_signatures()),
         function_template_info_(function_template_info),
         receiver_(receiver),
         holder_(holder),
@@ -898,8 +899,8 @@ class FastApiCallReducerAssembler : public JSCallReducerAssembler {
         target_(target),
         arity_(arity) {
     DCHECK_EQ(IrOpcode::kJSCall, node->opcode());
-    DCHECK_NE(c_function_, kNullAddress);
-    CHECK_NOT_NULL(c_signature_);
+    CHECK_GT(c_functions_.size(), 0);
+    CHECK_GT(c_signatures_.size(), 0);
     InitializeEffectControl(effect, NodeProperties::GetControlInput(node));
   }
 
@@ -908,13 +909,16 @@ class FastApiCallReducerAssembler : public JSCallReducerAssembler {
     // C arguments include the receiver at index 0. Thus C index 1 corresponds
     // to the JS argument 0, etc.
     const int c_argument_count =
-        static_cast<int>(c_signature_->ArgumentCount());
+        static_cast<int>(c_signatures_[0]->ArgumentCount());
     CHECK_GE(c_argument_count, kReceiver);
 
     int cursor = 0;
     base::SmallVector<Node*, kInlineSize> inputs(c_argument_count + arity_ +
                                                  kExtraInputsCount);
-    inputs[cursor++] = ExternalConstant(ExternalReference::Create(c_function_));
+    // Multiple function overloads not supported yet, always call the first
+    // overload.
+    inputs[cursor++] =
+        ExternalConstant(ExternalReference::Create(c_functions_[0]));
 
     inputs[cursor++] = n.receiver();
 
@@ -986,12 +990,12 @@ class FastApiCallReducerAssembler : public JSCallReducerAssembler {
   TNode<Object> FastApiCall(CallDescriptor* descriptor, Node** inputs,
                             size_t inputs_size) {
     return AddNode<Object>(graph()->NewNode(
-        simplified()->FastApiCall(c_signature_, feedback(), descriptor),
+        simplified()->FastApiCall(c_signatures_[0], feedback(), descriptor),
         static_cast<int>(inputs_size), inputs));
   }
 
-  const Address c_function_;
-  const CFunctionInfo* const c_signature_;
+  const ZoneVector<Address> c_functions_;
+  const ZoneVector<const CFunctionInfo*> c_signatures_;
   const FunctionTemplateInfoRef function_template_info_;
   Node* const receiver_;
   Node* const holder_;
@@ -2170,17 +2174,17 @@ TNode<Object> PromiseBuiltinReducerAssembler::ReducePromiseConstructor(
                    TrueConstant());
 
   // Allocate closures for the resolve and reject cases.
-  SharedFunctionInfoRef resolve_sfi(
-      broker_, broker_->isolate()
-                   ->factory()
-                   ->promise_capability_default_resolve_shared_fun());
+  SharedFunctionInfoRef resolve_sfi =
+      MakeRef(broker_, broker_->isolate()
+                           ->factory()
+                           ->promise_capability_default_resolve_shared_fun());
   TNode<JSFunction> resolve =
       CreateClosureFromBuiltinSharedFunctionInfo(resolve_sfi, promise_context);
 
-  SharedFunctionInfoRef reject_sfi(
-      broker_, broker_->isolate()
-                   ->factory()
-                   ->promise_capability_default_reject_shared_fun());
+  SharedFunctionInfoRef reject_sfi =
+      MakeRef(broker_, broker_->isolate()
+                           ->factory()
+                           ->promise_capability_default_reject_shared_fun());
   TNode<JSFunction> reject =
       CreateClosureFromBuiltinSharedFunctionInfo(reject_sfi, promise_context);
 
@@ -2447,6 +2451,10 @@ Reduction JSCallReducer::ReduceObjectConstructor(Node* node) {
 Reduction JSCallReducer::ReduceFunctionPrototypeApply(Node* node) {
   JSCallNode n(node);
   CallParameters const& p = n.Parameters();
+  CallFeedbackRelation new_feedback_relation =
+      p.feedback_relation() == CallFeedbackRelation::kReceiver
+          ? CallFeedbackRelation::kTarget
+          : CallFeedbackRelation::kUnrelated;
   int arity = p.arity_without_implicit_args();
   ConvertReceiverMode convert_mode = ConvertReceiverMode::kAny;
   if (arity == 0) {
@@ -2479,9 +2487,9 @@ Reduction JSCallReducer::ReduceFunctionPrototypeApply(Node* node) {
 
       // Morph the {node} to a {JSCallWithArrayLike}.
       NodeProperties::ChangeOp(
-          node, javascript()->CallWithArrayLike(
-                    p.frequency(), p.feedback(), p.speculation_mode(),
-                    CallFeedbackRelation::kUnrelated));
+          node, javascript()->CallWithArrayLike(p.frequency(), p.feedback(),
+                                                p.speculation_mode(),
+                                                new_feedback_relation));
       return Changed(node).FollowedBy(ReduceJSCallWithArrayLike(node));
     } else {
       // Check whether {arguments_list} is null.
@@ -2509,7 +2517,7 @@ Reduction JSCallReducer::ReduceFunctionPrototypeApply(Node* node) {
       Node* value0 = effect0 = control0 = graph()->NewNode(
           javascript()->CallWithArrayLike(p.frequency(), p.feedback(),
                                           p.speculation_mode(),
-                                          CallFeedbackRelation::kUnrelated),
+                                          new_feedback_relation),
           target, this_argument, arguments_list, n.feedback_vector(), context,
           frame_state, effect0, control0);
 
@@ -2559,7 +2567,7 @@ Reduction JSCallReducer::ReduceFunctionPrototypeApply(Node* node) {
   NodeProperties::ChangeOp(
       node, javascript()->Call(JSCallNode::ArityForArgc(arity), p.frequency(),
                                p.feedback(), convert_mode, p.speculation_mode(),
-                               CallFeedbackRelation::kUnrelated));
+                               new_feedback_relation));
   // Try to further reduce the JSCall {node}.
   return Changed(node).FollowedBy(ReduceJSCall(node));
 }
@@ -2591,28 +2599,20 @@ Reduction JSCallReducer::ReduceFunctionPrototypeBind(Node* node) {
   if (!inference.HaveMaps()) return NoChange();
   MapHandles const& receiver_maps = inference.GetMaps();
 
-  MapRef first_receiver_map(broker(), receiver_maps[0]);
+  MapRef first_receiver_map = MakeRef(broker(), receiver_maps[0]);
   bool const is_constructor = first_receiver_map.is_constructor();
 
-  if (first_receiver_map.ShouldHaveBeenSerialized() &&
-      !first_receiver_map.serialized_prototype()) {
-    TRACE_BROKER_MISSING(broker(),
-                         "serialized prototype on map " << first_receiver_map);
-    return inference.NoChange();
-  }
-  ObjectRef const prototype = first_receiver_map.prototype();
-  for (Handle<Map> const map : receiver_maps) {
-    MapRef receiver_map(broker(), map);
+  base::Optional<HeapObjectRef> const prototype =
+      first_receiver_map.prototype();
+  if (!prototype.has_value()) return inference.NoChange();
 
-    if (receiver_map.ShouldHaveBeenSerialized() &&
-        !receiver_map.serialized_prototype()) {
-      TRACE_BROKER_MISSING(broker(),
-                           "serialized prototype on map " << receiver_map);
-      return inference.NoChange();
-    }
+  for (Handle<Map> const map : receiver_maps) {
+    MapRef receiver_map = MakeRef(broker(), map);
+    base::Optional<HeapObjectRef> map_prototype = receiver_map.prototype();
+    if (!map_prototype.has_value()) return inference.NoChange();
 
     // Check for consistency among the {receiver_maps}.
-    if (!receiver_map.prototype().equals(prototype) ||
+    if (!map_prototype->equals(*prototype) ||
         receiver_map.is_constructor() != is_constructor ||
         !InstanceTypeChecker::IsJSFunctionOrBoundFunction(
             receiver_map.instance_type())) {
@@ -2643,8 +2643,8 @@ Reduction JSCallReducer::ReduceFunctionPrototypeBind(Node* node) {
       return inference.NoChange();
     }
     ReadOnlyRoots roots(isolate());
-    StringRef length_string(broker(), roots.length_string_handle());
-    StringRef name_string(broker(), roots.name_string_handle());
+    StringRef length_string = MakeRef(broker(), roots.length_string_handle());
+    StringRef name_string = MakeRef(broker(), roots.name_string_handle());
 
     base::Optional<ObjectRef> length_value(
         receiver_map.GetStrongValue(kLengthIndex));
@@ -2668,7 +2668,7 @@ Reduction JSCallReducer::ReduceFunctionPrototypeBind(Node* node) {
   MapRef map = is_constructor
                    ? native_context().bound_function_with_constructor_map()
                    : native_context().bound_function_without_constructor_map();
-  if (!map.prototype().equals(prototype)) return inference.NoChange();
+  if (!map.prototype().value().equals(*prototype)) return inference.NoChange();
 
   inference.RelyOnMapsPreferStability(dependencies(), jsgraph(), &effect,
                                       control, p.feedback());
@@ -2677,6 +2677,15 @@ Reduction JSCallReducer::ReduceFunctionPrototypeBind(Node* node) {
   static constexpr int kBoundThis = 1;
   static constexpr int kReceiverContextEffectAndControl = 4;
   int const arity = n.ArgumentCount();
+
+  if (arity > 0) {
+    MapRef fixed_array_map = MakeRef(broker(), factory()->fixed_array_map());
+    AllocationBuilder ab(jsgraph(), effect, control);
+    if (!ab.CanAllocateArray(arity, fixed_array_map)) {
+      return NoChange();
+    }
+  }
+
   int const arity_with_bound_this = std::max(arity, kBoundThis);
   int const input_count =
       arity_with_bound_this + kReceiverContextEffectAndControl;
@@ -2713,10 +2722,7 @@ Reduction JSCallReducer::ReduceFunctionPrototypeCall(Node* node) {
   HeapObjectMatcher m(target);
   if (m.HasResolvedValue() && m.Ref(broker()).IsJSFunction()) {
     JSFunctionRef function = m.Ref(broker()).AsJSFunction();
-    if (function.ShouldHaveBeenSerialized() && !function.serialized()) {
-      TRACE_BROKER_MISSING(broker(), "Serialize call on function " << function);
-      return NoChange();
-    }
+    if (!function.serialized()) return NoChange();
     context = jsgraph()->Constant(function.context());
   } else {
     context = effect = graph()->NewNode(
@@ -2785,24 +2791,17 @@ Reduction JSCallReducer::ReduceObjectGetPrototype(Node* node, Node* object) {
   if (!inference.HaveMaps()) return NoChange();
   MapHandles const& object_maps = inference.GetMaps();
 
-  MapRef candidate_map(broker(), object_maps[0]);
-  if (candidate_map.ShouldHaveBeenSerialized() &&
-      !candidate_map.serialized_prototype()) {
-    TRACE_BROKER_MISSING(broker(), "prototype for map " << candidate_map);
-    return inference.NoChange();
-  }
-  ObjectRef candidate_prototype = candidate_map.prototype();
+  MapRef candidate_map = MakeRef(broker(), object_maps[0]);
+  base::Optional<HeapObjectRef> candidate_prototype = candidate_map.prototype();
+  if (!candidate_prototype.has_value()) return inference.NoChange();
 
   // Check if we can constant-fold the {candidate_prototype}.
   for (size_t i = 0; i < object_maps.size(); ++i) {
-    MapRef object_map(broker(), object_maps[i]);
-    if (object_map.ShouldHaveBeenSerialized() &&
-        !object_map.serialized_prototype()) {
-      TRACE_BROKER_MISSING(broker(), "prototype for map " << object_map);
-      return inference.NoChange();
-    }
+    MapRef object_map = MakeRef(broker(), object_maps[i]);
+    base::Optional<HeapObjectRef> map_prototype = object_map.prototype();
+    if (!map_prototype.has_value()) return inference.NoChange();
     if (IsSpecialReceiverInstanceType(object_map.instance_type()) ||
-        !object_map.prototype().equals(candidate_prototype)) {
+        !map_prototype->equals(*candidate_prototype)) {
       // We exclude special receivers, like JSProxy or API objects that
       // might require access checks here; we also don't want to deal
       // with hidden prototypes at this point.
@@ -2815,7 +2814,7 @@ Reduction JSCallReducer::ReduceObjectGetPrototype(Node* node, Node* object) {
   if (!inference.RelyOnMapsViaStability(dependencies())) {
     return inference.NoChange();
   }
-  Node* value = jsgraph()->Constant(candidate_prototype);
+  Node* value = jsgraph()->Constant(*candidate_prototype);
   ReplaceWithValue(node, value);
   return Replace(value);
 }
@@ -3177,9 +3176,9 @@ bool CanInlineArrayIteratingBuiltin(JSHeapBroker* broker,
                                     MapHandles const& receiver_maps,
                                     ElementsKind* kind_return) {
   DCHECK_NE(0, receiver_maps.size());
-  *kind_return = MapRef(broker, receiver_maps[0]).elements_kind();
+  *kind_return = MakeRef(broker, receiver_maps[0]).elements_kind();
   for (auto receiver_map : receiver_maps) {
-    MapRef map(broker, receiver_map);
+    MapRef map = MakeRef(broker, receiver_map);
     if (!map.supports_fast_array_iteration() ||
         !UnionElementsKindUptoSize(kind_return, map.elements_kind())) {
       return false;
@@ -3194,7 +3193,7 @@ bool CanInlineArrayResizingBuiltin(JSHeapBroker* broker,
                                    bool builtin_is_push = false) {
   DCHECK_NE(0, receiver_maps.size());
   for (auto receiver_map : receiver_maps) {
-    MapRef map(broker, receiver_map);
+    MapRef map = MakeRef(broker, receiver_map);
     if (!map.supports_fast_array_resize()) return false;
     // TODO(turbofan): We should also handle fast holey double elements once
     // we got the hole NaN mess sorted out in TurboFan/V8.
@@ -3432,8 +3431,8 @@ Reduction JSCallReducer::ReduceArraySome(Node* node,
 #if V8_ENABLE_WEBASSEMBLY
 
 namespace {
+
 bool CanInlineJSToWasmCall(const wasm::FunctionSig* wasm_signature) {
-  DCHECK(FLAG_turbo_inline_js_wasm_calls);
   if (wasm_signature->return_count() > 1) {
     return false;
   }
@@ -3450,10 +3449,13 @@ bool CanInlineJSToWasmCall(const wasm::FunctionSig* wasm_signature) {
 
   return true;
 }
+
 }  // namespace
 
 Reduction JSCallReducer::ReduceCallWasmFunction(
     Node* node, const SharedFunctionInfoRef& shared) {
+  DCHECK(flags() & kInlineJSToWasmCalls);
+
   JSCallNode n(node);
   const CallParameters& p = n.Parameters();
 
@@ -3540,11 +3542,13 @@ bool Has64BitIntegerParamsInSignature(const CFunctionInfo* c_signature) {
 
 bool CanOptimizeFastCall(
     const FunctionTemplateInfoRef& function_template_info) {
-  const CFunctionInfo* c_signature = function_template_info.c_signature();
+  if (function_template_info.c_functions().empty()) return false;
+
+  // Multiple function overloads not supported yet, always call the first
+  // overload.
+  const CFunctionInfo* c_signature = function_template_info.c_signatures()[0];
 
-  bool optimize_to_fast_call =
-      FLAG_turbo_fast_api_calls &&
-      function_template_info.c_function() != kNullAddress;
+  bool optimize_to_fast_call = FLAG_turbo_fast_api_calls;
 #ifndef V8_ENABLE_FP_PARAMS_IN_C_LINKAGE
   optimize_to_fast_call =
       optimize_to_fast_call && !HasFPParamsInSignature(c_signature);
@@ -3612,7 +3616,7 @@ Reduction JSCallReducer::ReduceCallApiFunction(
     MapInference inference(broker(), receiver, effect);
     if (inference.HaveMaps()) {
       MapHandles const& receiver_maps = inference.GetMaps();
-      MapRef first_receiver_map(broker(), receiver_maps[0]);
+      MapRef first_receiver_map = MakeRef(broker(), receiver_maps[0]);
 
       // See if we can constant-fold the compatible receiver checks.
       HolderLookupResult api_holder =
@@ -3645,7 +3649,7 @@ Reduction JSCallReducer::ReduceCallApiFunction(
             function_template_info.accept_any_receiver());
 
       for (size_t i = 1; i < receiver_maps.size(); ++i) {
-        MapRef receiver_map(broker(), receiver_maps[i]);
+        MapRef receiver_map = MakeRef(broker(), receiver_maps[i]);
         HolderLookupResult holder_i =
             function_template_info.LookupHolderOfExpectedType(receiver_map);
 
@@ -3893,8 +3897,8 @@ Reduction JSCallReducer::ReduceCallOrConstructWithArrayLikeOrSpread(
     if (!frame_state.frame_state_info().shared_info().ToHandle(&shared)) {
       return NoChange();
     }
-    formal_parameter_count = SharedFunctionInfoRef(broker(), shared)
-                                 .internal_formal_parameter_count();
+    formal_parameter_count =
+        MakeRef(broker(), shared).internal_formal_parameter_count();
   }
 
   if (type == CreateArgumentsType::kMappedArguments) {
@@ -3971,10 +3975,9 @@ Reduction JSCallReducer::ReduceCallOrConstructWithArrayLikeOrSpread(
 
   if (IsCallWithArrayLikeOrSpread(node)) {
     NodeProperties::ChangeOp(
-        node,
-        javascript()->Call(JSCallNode::ArityForArgc(argc), frequency, feedback,
-                           ConvertReceiverMode::kAny, speculation_mode,
-                           CallFeedbackRelation::kUnrelated));
+        node, javascript()->Call(JSCallNode::ArityForArgc(argc), frequency,
+                                 feedback, ConvertReceiverMode::kAny,
+                                 speculation_mode, feedback_relation));
     return Changed(node).FollowedBy(ReduceJSCall(node));
   } else {
     NodeProperties::ChangeOp(
@@ -4048,7 +4051,9 @@ bool ShouldUseCallICFeedback(Node* node) {
   } else if (m.IsPhi()) {
     // Protect against endless loops here.
     Node* control = NodeProperties::GetControlInput(node);
-    if (control->opcode() == IrOpcode::kLoop) return false;
+    if (control->opcode() == IrOpcode::kLoop ||
+        control->opcode() == IrOpcode::kDead)
+      return false;
     // Check if {node} is a Phi of nodes which shouldn't
     // use CallIC feedback (not looking through loops).
     int const value_input_count = m.node()->op()->ValueInputCount();
@@ -4063,11 +4068,7 @@ bool ShouldUseCallICFeedback(Node* node) {
 }  // namespace
 
 bool JSCallReducer::IsBuiltinOrApiFunction(JSFunctionRef function) const {
-  if (function.ShouldHaveBeenSerialized() && !function.serialized()) {
-    TRACE_BROKER_MISSING(broker(), "data for function " << function);
-    return false;
-  }
-
+  if (!function.serialized()) return false;
   // TODO(neis): Add a way to check if function template info isn't serialized
   // and add a warning in such cases. Currently we can't tell if function
   // template info doesn't exist or wasn't serialized.
@@ -4091,10 +4092,7 @@ Reduction JSCallReducer::ReduceJSCall(Node* node) {
     ObjectRef target_ref = m.Ref(broker());
     if (target_ref.IsJSFunction()) {
       JSFunctionRef function = target_ref.AsJSFunction();
-      if (function.ShouldHaveBeenSerialized() && !function.serialized()) {
-        TRACE_BROKER_MISSING(broker(), "data for function " << function);
-        return NoChange();
-      }
+      if (!function.serialized()) return NoChange();
 
       // Don't inline cross native context.
       if (!function.native_context().equals(native_context())) {
@@ -4104,10 +4102,7 @@ Reduction JSCallReducer::ReduceJSCall(Node* node) {
       return ReduceJSCall(node, function.shared());
     } else if (target_ref.IsJSBoundFunction()) {
       JSBoundFunctionRef function = target_ref.AsJSBoundFunction();
-      if (function.ShouldHaveBeenSerialized() && !function.serialized()) {
-        TRACE_BROKER_MISSING(broker(), "data for function " << function);
-        return NoChange();
-      }
+      if (!function.serialized()) return NoChange();
 
       ObjectRef bound_this = function.bound_this();
       ConvertReceiverMode const convert_mode =
@@ -4115,6 +4110,21 @@ Reduction JSCallReducer::ReduceJSCall(Node* node) {
               ? ConvertReceiverMode::kNullOrUndefined
               : ConvertReceiverMode::kNotNullOrUndefined;
 
+      // TODO(jgruber): Inline this block below once TryGet is guaranteed to
+      // succeed.
+      FixedArrayRef bound_arguments = function.bound_arguments();
+      const int bound_arguments_length = bound_arguments.length();
+      static constexpr int kInlineSize = 16;  // Arbitrary.
+      base::SmallVector<Node*, kInlineSize> args;
+      for (int i = 0; i < bound_arguments_length; ++i) {
+        base::Optional<ObjectRef> maybe_arg = bound_arguments.TryGet(i);
+        if (!maybe_arg.has_value()) {
+          TRACE_BROKER_MISSING(broker(), "bound argument");
+          return NoChange();
+        }
+        args.emplace_back(jsgraph()->Constant(maybe_arg.value()));
+      }
+
       // Patch {node} to use [[BoundTargetFunction]] and [[BoundThis]].
       NodeProperties::ReplaceValueInput(
           node, jsgraph()->Constant(function.bound_target_function()),
@@ -4123,10 +4133,8 @@ Reduction JSCallReducer::ReduceJSCall(Node* node) {
                                         JSCallNode::ReceiverIndex());
 
       // Insert the [[BoundArguments]] for {node}.
-      FixedArrayRef bound_arguments = function.bound_arguments();
-      for (int i = 0; i < bound_arguments.length(); ++i) {
-        node->InsertInput(graph()->zone(), i + 2,
-                          jsgraph()->Constant(bound_arguments.get(i)));
+      for (int i = 0; i < bound_arguments_length; ++i) {
+        node->InsertInput(graph()->zone(), i + 2, args[i]);
         arity++;
       }
 
@@ -4152,9 +4160,9 @@ Reduction JSCallReducer::ReduceJSCall(Node* node) {
   // Same if the {target} is the result of a CheckClosure operation.
   if (target->opcode() == IrOpcode::kJSCreateClosure) {
     CreateClosureParameters const& p = JSCreateClosureNode{target}.Parameters();
-    return ReduceJSCall(node, SharedFunctionInfoRef(broker(), p.shared_info()));
+    return ReduceJSCall(node, MakeRef(broker(), p.shared_info()));
   } else if (target->opcode() == IrOpcode::kCheckClosure) {
-    FeedbackCellRef cell(broker(), FeedbackCellOf(target->op()));
+    FeedbackCellRef cell = MakeRef(broker(), FeedbackCellOf(target->op()));
     if (cell.shared_function_info().has_value()) {
       return ReduceJSCall(node, *cell.shared_function_info());
     } else {
@@ -4201,7 +4209,7 @@ Reduction JSCallReducer::ReduceJSCall(Node* node) {
   }
 
   if (!ShouldUseCallICFeedback(target) ||
-      p.feedback_relation() != CallFeedbackRelation::kRelated ||
+      p.feedback_relation() == CallFeedbackRelation::kUnrelated ||
       !p.feedback().IsValid()) {
     return NoChange();
   }
@@ -4213,7 +4221,14 @@ Reduction JSCallReducer::ReduceJSCall(Node* node) {
         node, DeoptimizeReason::kInsufficientTypeFeedbackForCall);
   }
 
-  base::Optional<HeapObjectRef> feedback_target = feedback.AsCall().target();
+  base::Optional<HeapObjectRef> feedback_target;
+  if (p.feedback_relation() == CallFeedbackRelation::kTarget) {
+    feedback_target = feedback.AsCall().target();
+  } else {
+    DCHECK_EQ(p.feedback_relation(), CallFeedbackRelation::kReceiver);
+    feedback_target = native_context().function_prototype_apply();
+  }
+
   if (feedback_target.has_value() && feedback_target->map().is_callable()) {
     Node* target_function = jsgraph()->Constant(*feedback_target);
 
@@ -4238,8 +4253,8 @@ Reduction JSCallReducer::ReduceJSCall(Node* node) {
     // Try to further reduce the JSCall {node}.
     return Changed(node).FollowedBy(ReduceJSCall(node));
   } else if (feedback_target.has_value() && feedback_target->IsFeedbackCell()) {
-    FeedbackCellRef feedback_cell(
-        broker(), feedback_target.value().AsFeedbackCell().object());
+    FeedbackCellRef feedback_cell =
+        MakeRef(broker(), feedback_target.value().AsFeedbackCell().object());
     if (feedback_cell.value().has_value()) {
       // Check that {target} is a closure with given {feedback_cell},
       // which uniquely identifies a given function inside a native context.
@@ -4276,6 +4291,9 @@ Reduction JSCallReducer::ReduceJSCall(Node* node,
   Node* target = n.target();
 
   // Do not reduce calls to functions with break points.
+  // If this state changes during background compilation, the compilation
+  // job will be aborted from the main thread (see
+  // Debug::PrepareFunctionForDebugExecution()).
   if (shared.HasBreakInfo()) return NoChange();
 
   // Raise a TypeError if the {target} is a "classConstructor".
@@ -4736,13 +4754,12 @@ Reduction JSCallReducer::ReduceJSConstruct(Node* node) {
 
     if (target_ref.IsJSFunction()) {
       JSFunctionRef function = target_ref.AsJSFunction();
-      if (function.ShouldHaveBeenSerialized() && !function.serialized()) {
-        TRACE_BROKER_MISSING(broker(),
-                             "function, not serialized: " << function);
-        return NoChange();
-      }
+      if (!function.serialized()) return NoChange();
 
       // Do not reduce constructors with break points.
+      // If this state changes during background compilation, the compilation
+      // job will be aborted from the main thread (see
+      // Debug::PrepareFunctionForDebugExecution()).
       if (function.shared().HasBreakInfo()) return NoChange();
 
       // Don't inline cross native context.
@@ -4799,14 +4816,23 @@ Reduction JSCallReducer::ReduceJSConstruct(Node* node) {
       }
     } else if (target_ref.IsJSBoundFunction()) {
       JSBoundFunctionRef function = target_ref.AsJSBoundFunction();
-      if (function.ShouldHaveBeenSerialized() && !function.serialized()) {
-        TRACE_BROKER_MISSING(broker(),
-                             "function, not serialized: " << function);
-        return NoChange();
-      }
-
+      if (!function.serialized()) return NoChange();
       ObjectRef bound_target_function = function.bound_target_function();
       FixedArrayRef bound_arguments = function.bound_arguments();
+      const int bound_arguments_length = bound_arguments.length();
+
+      // TODO(jgruber): Inline this block below once TryGet is guaranteed to
+      // succeed.
+      static constexpr int kInlineSize = 16;  // Arbitrary.
+      base::SmallVector<Node*, kInlineSize> args;
+      for (int i = 0; i < bound_arguments_length; ++i) {
+        base::Optional<ObjectRef> maybe_arg = bound_arguments.TryGet(i);
+        if (!maybe_arg.has_value()) {
+          TRACE_BROKER_MISSING(broker(), "bound argument");
+          return NoChange();
+        }
+        args.emplace_back(jsgraph()->Constant(maybe_arg.value()));
+      }
 
       // Patch {node} to use [[BoundTargetFunction]].
       node->ReplaceInput(n.TargetIndex(),
@@ -4823,9 +4849,8 @@ Reduction JSCallReducer::ReduceJSConstruct(Node* node) {
                            new_target));
 
       // Insert the [[BoundArguments]] for {node}.
-      for (int i = 0; i < bound_arguments.length(); ++i) {
-        node->InsertInput(graph()->zone(), n.ArgumentIndex(i),
-                          jsgraph()->Constant(bound_arguments.get(i)));
+      for (int i = 0; i < bound_arguments_length; ++i) {
+        node->InsertInput(graph()->zone(), n.ArgumentIndex(i), args[i]);
         arity++;
       }
 
@@ -5064,7 +5089,7 @@ Reduction JSCallReducer::ReduceJSConstructWithArrayLike(Node* node) {
   DCHECK_EQ(n.ArgumentCount(), 1);  // The arraylike object.
   return ReduceCallOrConstructWithArrayLikeOrSpread(
       node, arraylike_index, p.frequency(), p.feedback(),
-      SpeculationMode::kDisallowSpeculation, CallFeedbackRelation::kRelated);
+      SpeculationMode::kDisallowSpeculation, CallFeedbackRelation::kTarget);
 }
 
 Reduction JSCallReducer::ReduceJSConstructWithSpread(Node* node) {
@@ -5074,7 +5099,7 @@ Reduction JSCallReducer::ReduceJSConstructWithSpread(Node* node) {
   DCHECK_GE(n.ArgumentCount(), 1);  // At least the spread.
   return ReduceCallOrConstructWithArrayLikeOrSpread(
       node, spread_index, p.frequency(), p.feedback(),
-      SpeculationMode::kDisallowSpeculation, CallFeedbackRelation::kRelated);
+      SpeculationMode::kDisallowSpeculation, CallFeedbackRelation::kTarget);
 }
 
 Reduction JSCallReducer::ReduceReturnReceiver(Node* node) {
@@ -5611,8 +5636,8 @@ Reduction JSCallReducer::ReduceArrayPrototypeShift(Node* node) {
             graph()->zone(), 1, BuiltinArguments::kNumExtraArgsWithReceiver,
             Builtins::name(builtin_index), node->op()->properties(),
             CallDescriptor::kNeedsFrameState);
-        Node* stub_code = jsgraph()->CEntryStubConstant(1, kDontSaveFPRegs,
-                                                        kArgvOnStack, true);
+        Node* stub_code = jsgraph()->CEntryStubConstant(
+            1, SaveFPRegsMode::kIgnore, ArgvMode::kStack, true);
         Address builtin_entry = Builtins::CppEntryOf(builtin_index);
         Node* entry = jsgraph()->ExternalConstant(
             ExternalReference::Create(builtin_entry));
@@ -5701,16 +5726,18 @@ Reduction JSCallReducer::ReduceArrayPrototypeSlice(Node* node) {
   // `slice.call(arguments)`, for example jQuery makes heavy use of that.
   bool can_be_holey = false;
   for (Handle<Map> map : receiver_maps) {
-    MapRef receiver_map(broker(), map);
-    if (!receiver_map.supports_fast_array_iteration())
+    MapRef receiver_map = MakeRef(broker(), map);
+    if (!receiver_map.supports_fast_array_iteration()) {
       return inference.NoChange();
+    }
     if (IsHoleyElementsKind(receiver_map.elements_kind())) {
       can_be_holey = true;
     }
   }
 
-  if (!dependencies()->DependOnArraySpeciesProtector())
+  if (!dependencies()->DependOnArraySpeciesProtector()) {
     return inference.NoChange();
+  }
   if (can_be_holey && !dependencies()->DependOnNoElementsProtector()) {
     return inference.NoChange();
   }
@@ -5851,7 +5878,7 @@ Reduction JSCallReducer::ReduceArrayIteratorPrototypeNext(Node* node) {
 
   // Check that various {iterated_object_maps} have compatible elements kinds.
   ElementsKind elements_kind =
-      MapRef(broker(), iterated_object_maps[0]).elements_kind();
+      MakeRef(broker(), iterated_object_maps[0]).elements_kind();
   if (IsTypedArrayElementsKind(elements_kind)) {
     // TurboFan doesn't support loading from BigInt typed arrays yet.
     if (elements_kind == BIGUINT64_ELEMENTS ||
@@ -5859,7 +5886,7 @@ Reduction JSCallReducer::ReduceArrayIteratorPrototypeNext(Node* node) {
       return inference.NoChange();
     }
     for (Handle<Map> map : iterated_object_maps) {
-      MapRef iterated_object_map(broker(), map);
+      MapRef iterated_object_map = MakeRef(broker(), map);
       if (iterated_object_map.elements_kind() != elements_kind) {
         return inference.NoChange();
       }
@@ -5947,11 +5974,12 @@ Reduction JSCallReducer::ReduceArrayIteratorPrototypeNext(Node* node) {
   Node* etrue = effect;
   Node* if_true = graph()->NewNode(common()->IfTrue(), branch);
   {
-    // We know that the {index} is range of the {length} now.
+    // This extra check exists to refine the type of {index} but also to break
+    // an exploitation technique that abuses typer mismatches.
     index = etrue = graph()->NewNode(
-        common()->TypeGuard(
-            Type::Range(0.0, length_access.type.Max() - 1.0, graph()->zone())),
-        index, etrue, if_true);
+        simplified()->CheckBounds(p.feedback(),
+                                  CheckBoundsFlag::kAbortOnOutOfBounds),
+        index, length, etrue, if_true);
 
     done_true = jsgraph()->FalseConstant();
     if (iteration_kind == IterationKind::kKeys) {
@@ -6475,15 +6503,11 @@ bool JSCallReducer::DoPromiseChecks(MapInference* inference) {
   // Check whether all {receiver_maps} are JSPromise maps and
   // have the initial Promise.prototype as their [[Prototype]].
   for (Handle<Map> map : receiver_maps) {
-    MapRef receiver_map(broker(), map);
+    MapRef receiver_map = MakeRef(broker(), map);
     if (!receiver_map.IsJSPromiseMap()) return false;
-    if (receiver_map.ShouldHaveBeenSerialized() &&
-        !receiver_map.serialized_prototype()) {
-      TRACE_BROKER_MISSING(broker(), "prototype for map " << receiver_map);
-      return false;
-    }
-    if (!receiver_map.prototype().equals(
-            native_context().promise_prototype())) {
+    base::Optional<HeapObjectRef> prototype = receiver_map.prototype();
+    if (!prototype.has_value() ||
+        !prototype->equals(native_context().promise_prototype())) {
       return false;
     }
   }
@@ -6604,14 +6628,14 @@ Reduction JSCallReducer::ReducePromisePrototypeFinally(Node* node) {
         context, constructor, etrue, if_true);
 
     // Allocate the closure for the reject case.
-    SharedFunctionInfoRef promise_catch_finally(
-        broker(), factory()->promise_catch_finally_shared_fun());
+    SharedFunctionInfoRef promise_catch_finally =
+        MakeRef(broker(), factory()->promise_catch_finally_shared_fun());
     catch_true = etrue = CreateClosureFromBuiltinSharedFunctionInfo(
         promise_catch_finally, context, etrue, if_true);
 
     // Allocate the closure for the fulfill case.
-    SharedFunctionInfoRef promise_then_finally(
-        broker(), factory()->promise_then_finally_shared_fun());
+    SharedFunctionInfoRef promise_then_finally =
+        MakeRef(broker(), factory()->promise_then_finally_shared_fun());
     then_true = etrue = CreateClosureFromBuiltinSharedFunctionInfo(
         promise_then_finally, context, etrue, if_true);
   }
@@ -7085,9 +7109,10 @@ Reduction JSCallReducer::ReduceCollectionIteratorPrototypeNext(
     MapInference inference(broker(), receiver, effect);
     if (!inference.HaveMaps()) return NoChange();
     MapHandles const& receiver_maps = inference.GetMaps();
-    receiver_instance_type = MapRef(broker(), receiver_maps[0]).instance_type();
+    receiver_instance_type =
+        MakeRef(broker(), receiver_maps[0]).instance_type();
     for (size_t i = 1; i < receiver_maps.size(); ++i) {
-      if (MapRef(broker(), receiver_maps[i]).instance_type() !=
+      if (MakeRef(broker(), receiver_maps[i]).instance_type() !=
           receiver_instance_type) {
         return inference.NoChange();
       }
@@ -7690,10 +7715,10 @@ Reduction JSCallReducer::ReduceRegExpPrototypeTest(Node* node) {
   if (broker()->is_concurrent_inlining()) {
     // Obtain precomputed access infos from the broker.
     for (auto map : regexp_maps) {
-      MapRef map_ref(broker(), map);
+      MapRef map_ref = MakeRef(broker(), map);
       PropertyAccessInfo access_info = broker()->GetPropertyAccessInfo(
-          map_ref, NameRef(broker(), isolate()->factory()->exec_string()),
-          AccessMode::kLoad);
+          map_ref, MakeRef(broker(), isolate()->factory()->exec_string()),
+          AccessMode::kLoad, dependencies());
       access_infos.push_back(access_info);
     }
   } else {
@@ -7714,7 +7739,7 @@ Reduction JSCallReducer::ReduceRegExpPrototypeTest(Node* node) {
     // Do not reduce if the exec method is not on the prototype chain.
     if (!ai_exec.holder().ToHandle(&holder)) return inference.NoChange();
 
-    JSObjectRef holder_ref(broker(), holder);
+    JSObjectRef holder_ref = MakeRef(broker(), holder);
 
     // Bail out if the exec method is not the original one.
     base::Optional<ObjectRef> constant = holder_ref.GetOwnFastDataProperty(
@@ -7727,7 +7752,7 @@ Reduction JSCallReducer::ReduceRegExpPrototypeTest(Node* node) {
     // Add proper dependencies on the {regexp}s [[Prototype]]s.
     dependencies()->DependOnStablePrototypeChains(
         ai_exec.lookup_start_object_maps(), kStartAtPrototype,
-        JSObjectRef(broker(), holder));
+        MakeRef(broker(), holder));
   } else {
     // TODO(v8:11457) Support dictionary mode protoypes here.
     return inference.NoChange();
@@ -7814,9 +7839,9 @@ Reduction JSCallReducer::ReduceBigIntAsUintN(Node* node) {
   NumberMatcher matcher(bits);
   if (matcher.IsInteger() && matcher.IsInRange(0, 64)) {
     const int bits_value = static_cast<int>(matcher.ResolvedValue());
-    value = effect = graph()->NewNode(simplified()->CheckBigInt(p.feedback()),
-                                      value, effect, control);
-    value = graph()->NewNode(simplified()->BigIntAsUintN(bits_value), value);
+    value = effect = graph()->NewNode(
+        simplified()->SpeculativeBigIntAsUintN(bits_value, p.feedback()), value,
+        effect, control);
     ReplaceWithValue(node, value, effect);
     return Replace(value);
   }
diff --git a/chromium/v8/src/compiler/js-context-specialization.cc b/chromium/v8/src/compiler/js-context-specialization.cc
index 448652ad8df..9c53cf13154 100644
--- a/chromium/v8/src/compiler/js-context-specialization.cc
+++ b/chromium/v8/src/compiler/js-context-specialization.cc
@@ -40,7 +40,7 @@ Reduction JSContextSpecialization::ReduceParameter(Node* node) {
     // Constant-fold the function parameter {node}.
     Handle<JSFunction> function;
     if (closure().ToHandle(&function)) {
-      Node* value = jsgraph()->Constant(JSFunctionRef(broker_, function));
+      Node* value = jsgraph()->Constant(MakeRef(broker_, function));
       return Replace(value);
     }
   }
@@ -103,7 +103,7 @@ base::Optional<ContextRef> GetSpecializationContext(
     Maybe<OuterContext> maybe_outer) {
   switch (node->opcode()) {
     case IrOpcode::kHeapConstant: {
-      HeapObjectRef object(broker, HeapConstantOf(node->op()));
+      HeapObjectRef object = MakeRef(broker, HeapConstantOf(node->op()));
       if (object.IsContext()) return object.AsContext();
       break;
     }
@@ -112,7 +112,7 @@ base::Optional<ContextRef> GetSpecializationContext(
       if (maybe_outer.To(&outer) && IsContextParameter(node) &&
           *distance >= outer.distance) {
         *distance -= outer.distance;
-        return ContextRef(broker, outer.context);
+        return MakeRef(broker, outer.context);
       }
       break;
     }
@@ -231,7 +231,7 @@ base::Optional<ContextRef> GetModuleContext(JSHeapBroker* broker, Node* node,
 
   switch (context->opcode()) {
     case IrOpcode::kHeapConstant: {
-      HeapObjectRef object(broker, HeapConstantOf(context->op()));
+      HeapObjectRef object = MakeRef(broker, HeapConstantOf(context->op()));
       if (object.IsContext()) {
         return find_context(object.AsContext());
       }
@@ -240,7 +240,7 @@ base::Optional<ContextRef> GetModuleContext(JSHeapBroker* broker, Node* node,
     case IrOpcode::kParameter: {
       OuterContext outer;
       if (maybe_context.To(&outer) && IsContextParameter(context)) {
-        return find_context(ContextRef(broker, outer.context));
+        return find_context(MakeRef(broker, outer.context));
       }
       break;
     }
@@ -259,17 +259,18 @@ Reduction JSContextSpecialization::ReduceJSGetImportMeta(Node* node) {
   ContextRef context = maybe_context.value();
   SourceTextModuleRef module =
       context.get(Context::EXTENSION_INDEX).value().AsSourceTextModule();
-  ObjectRef import_meta = module.import_meta();
-  if (import_meta.IsJSObject()) {
-    Node* import_meta_const = jsgraph()->Constant(import_meta);
-    ReplaceWithValue(node, import_meta_const);
-    return Changed(import_meta_const);
-  } else {
-    DCHECK(import_meta.IsTheHole());
+  base::Optional<ObjectRef> import_meta = module.import_meta();
+  if (!import_meta.has_value()) return NoChange();
+  if (!import_meta->IsJSObject()) {
+    DCHECK(import_meta->IsTheHole());
     // The import.meta object has not yet been created. Let JSGenericLowering
     // replace the operator with a runtime call.
     return NoChange();
   }
+
+  Node* import_meta_const = jsgraph()->Constant(*import_meta);
+  ReplaceWithValue(node, import_meta_const);
+  return Changed(import_meta_const);
 }
 
 Isolate* JSContextSpecialization::isolate() const {
diff --git a/chromium/v8/src/compiler/js-create-lowering.cc b/chromium/v8/src/compiler/js-create-lowering.cc
index 899922a27fc..21ba072f315 100644
--- a/chromium/v8/src/compiler/js-create-lowering.cc
+++ b/chromium/v8/src/compiler/js-create-lowering.cc
@@ -151,8 +151,8 @@ Reduction JSCreateLowering::ReduceJSCreateArguments(Node* node) {
   FrameState frame_state{NodeProperties::GetFrameStateInput(node)};
   Node* const control = graph()->start();
   FrameStateInfo state_info = frame_state.frame_state_info();
-  SharedFunctionInfoRef shared(broker(),
-                               state_info.shared_info().ToHandleChecked());
+  SharedFunctionInfoRef shared =
+      MakeRef(broker(), state_info.shared_info().ToHandleChecked());
 
   // Use the ArgumentsAccessStub for materializing both mapped and unmapped
   // arguments object, but only for non-inlined (i.e. outermost) frames.
@@ -404,7 +404,7 @@ Reduction JSCreateLowering::ReduceJSCreateGeneratorObject(Node* node) {
     int parameter_count_no_receiver = shared.internal_formal_parameter_count();
     int length = parameter_count_no_receiver +
                  shared.GetBytecodeArray().register_count();
-    MapRef fixed_array_map(broker(), factory()->fixed_array_map());
+    MapRef fixed_array_map = MakeRef(broker(), factory()->fixed_array_map());
     AllocationBuilder ab(jsgraph(), effect, control);
     if (!ab.CanAllocateArray(length, fixed_array_map)) {
       return NoChange();
@@ -622,7 +622,7 @@ Reduction JSCreateLowering::ReduceJSCreateArray(Node* node) {
   {
     Handle<AllocationSite> site;
     if (p.site().ToHandle(&site)) {
-      site_ref = AllocationSiteRef(broker(), site);
+      site_ref = MakeRef(broker(), site);
     }
   }
   AllocationType allocation = AllocationType::kYoung;
@@ -650,8 +650,8 @@ Reduction JSCreateLowering::ReduceJSCreateArray(Node* node) {
     allocation = dependencies()->DependOnPretenureMode(*site_ref);
     dependencies()->DependOnElementsKind(*site_ref);
   } else {
-    PropertyCellRef array_constructor_protector(
-        broker(), factory()->array_constructor_protector());
+    PropertyCellRef array_constructor_protector =
+        MakeRef(broker(), factory()->array_constructor_protector());
     array_constructor_protector.SerializeAsProtector();
     can_inline_call = array_constructor_protector.value().AsSmi() ==
                       Protectors::kProtectorValid;
@@ -775,11 +775,9 @@ Reduction JSCreateLowering::ReduceJSCreateAsyncFunctionObject(Node* node) {
   Node* control = NodeProperties::GetControlInput(node);
 
   // Create the register file.
-  MapRef fixed_array_map(broker(), factory()->fixed_array_map());
+  MapRef fixed_array_map = MakeRef(broker(), factory()->fixed_array_map());
   AllocationBuilder ab(jsgraph(), effect, control);
-  if (!ab.CanAllocateArray(register_count, fixed_array_map)) {
-    return NoChange();
-  }
+  CHECK(ab.CanAllocateArray(register_count, fixed_array_map));
   ab.AllocateArray(register_count, fixed_array_map);
   for (int i = 0; i < register_count; ++i) {
     ab.Store(AccessBuilder::ForFixedArraySlot(i),
@@ -881,7 +879,7 @@ Reduction JSCreateLowering::ReduceJSCreateBoundFunction(Node* node) {
   CreateBoundFunctionParameters const& p =
       CreateBoundFunctionParametersOf(node->op());
   int const arity = static_cast<int>(p.arity());
-  MapRef const map(broker(), p.map());
+  MapRef const map = MakeRef(broker(), p.map());
   Node* bound_target_function = NodeProperties::GetValueInput(node, 0);
   Node* bound_this = NodeProperties::GetValueInput(node, 1);
   Node* effect = NodeProperties::GetEffectInput(node);
@@ -890,11 +888,9 @@ Reduction JSCreateLowering::ReduceJSCreateBoundFunction(Node* node) {
   // Create the [[BoundArguments]] for the result.
   Node* bound_arguments = jsgraph()->EmptyFixedArrayConstant();
   if (arity > 0) {
-    MapRef fixed_array_map(broker(), factory()->fixed_array_map());
+    MapRef fixed_array_map = MakeRef(broker(), factory()->fixed_array_map());
     AllocationBuilder ab(jsgraph(), effect, control);
-    if (!ab.CanAllocateArray(arity, fixed_array_map)) {
-      return NoChange();
-    }
+    CHECK(ab.CanAllocateArray(arity, fixed_array_map));
     ab.AllocateArray(arity, fixed_array_map);
     for (int i = 0; i < arity; ++i) {
       ab.Store(AccessBuilder::ForFixedArraySlot(i),
@@ -924,9 +920,9 @@ Reduction JSCreateLowering::ReduceJSCreateBoundFunction(Node* node) {
 Reduction JSCreateLowering::ReduceJSCreateClosure(Node* node) {
   JSCreateClosureNode n(node);
   CreateClosureParameters const& p = n.Parameters();
-  SharedFunctionInfoRef shared(broker(), p.shared_info());
+  SharedFunctionInfoRef shared = MakeRef(broker(), p.shared_info());
   FeedbackCellRef feedback_cell = n.GetFeedbackCellRefChecked(broker());
-  HeapObjectRef code(broker(), p.code());
+  HeapObjectRef code = MakeRef(broker(), p.code());
   Effect effect = n.effect();
   Control control = n.control();
   Node* context = n.context();
@@ -935,7 +931,7 @@ Reduction JSCreateLowering::ReduceJSCreateClosure(Node* node) {
   // seen more than one instantiation, this simplifies the generated code and
   // also serves as a heuristic of which allocation sites benefit from it.
   if (!feedback_cell.map().equals(
-          MapRef(broker(), factory()->many_closures_cell_map()))) {
+          MakeRef(broker(), factory()->many_closures_cell_map()))) {
     return NoChange();
   }
 
@@ -1041,7 +1037,7 @@ Reduction JSCreateLowering::ReduceJSCreateKeyValueArray(Node* node) {
   Node* length = jsgraph()->Constant(2);
 
   AllocationBuilder aa(jsgraph(), effect, graph()->start());
-  aa.AllocateArray(2, MapRef(broker(), factory()->fixed_array_map()));
+  aa.AllocateArray(2, MakeRef(broker(), factory()->fixed_array_map()));
   aa.Store(AccessBuilder::ForFixedArrayElement(PACKED_ELEMENTS),
            jsgraph()->ZeroConstant(), key);
   aa.Store(AccessBuilder::ForFixedArrayElement(PACKED_ELEMENTS),
@@ -1100,14 +1096,21 @@ Reduction JSCreateLowering::ReduceJSCreateLiteralArrayOrObject(Node* node) {
   if (!feedback.IsInsufficient()) {
     AllocationSiteRef site = feedback.AsLiteral().value();
     if (site.IsFastLiteral()) {
-      AllocationType allocation = AllocationType::kYoung;
+      AllocationType allocation = FLAG_allocation_site_pretenuring
+                                      ? site.GetAllocationType()
+                                      : AllocationType::kYoung;
+      JSObjectRef boilerplate = site.boilerplate().value();
+      base::Optional<Node*> maybe_value =
+          TryAllocateFastLiteral(effect, control, boilerplate, allocation);
+      if (!maybe_value.has_value()) {
+        TRACE_BROKER_MISSING(broker(), "bound argument");
+        return NoChange();
+      }
       if (FLAG_allocation_site_pretenuring) {
-        allocation = dependencies()->DependOnPretenureMode(site);
+        CHECK_EQ(dependencies()->DependOnPretenureMode(site), allocation);
       }
       dependencies()->DependOnElementsKinds(site);
-      JSObjectRef boilerplate = site.boilerplate().value();
-      Node* value = effect =
-          AllocateFastLiteral(effect, control, boilerplate, allocation);
+      Node* value = effect = maybe_value.value();
       ReplaceWithValue(node, value, effect, control);
       return Replace(value);
     }
@@ -1209,7 +1212,7 @@ Reduction JSCreateLowering::ReduceJSCreateFunctionContext(Node* node) {
   DCHECK_EQ(IrOpcode::kJSCreateFunctionContext, node->opcode());
   const CreateFunctionContextParameters& parameters =
       CreateFunctionContextParametersOf(node->op());
-  ScopeInfoRef scope_info(broker(), parameters.scope_info());
+  ScopeInfoRef scope_info = MakeRef(broker(), parameters.scope_info());
   int slot_count = parameters.slot_count();
   ScopeType scope_type = parameters.scope_type();
 
@@ -1249,7 +1252,7 @@ Reduction JSCreateLowering::ReduceJSCreateFunctionContext(Node* node) {
 
 Reduction JSCreateLowering::ReduceJSCreateWithContext(Node* node) {
   DCHECK_EQ(IrOpcode::kJSCreateWithContext, node->opcode());
-  ScopeInfoRef scope_info(broker(), ScopeInfoOf(node->op()));
+  ScopeInfoRef scope_info = MakeRef(broker(), ScopeInfoOf(node->op()));
   Node* extension = NodeProperties::GetValueInput(node, 0);
   Node* effect = NodeProperties::GetEffectInput(node);
   Node* control = NodeProperties::GetControlInput(node);
@@ -1270,7 +1273,7 @@ Reduction JSCreateLowering::ReduceJSCreateWithContext(Node* node) {
 
 Reduction JSCreateLowering::ReduceJSCreateCatchContext(Node* node) {
   DCHECK_EQ(IrOpcode::kJSCreateCatchContext, node->opcode());
-  ScopeInfoRef scope_info(broker(), ScopeInfoOf(node->op()));
+  ScopeInfoRef scope_info = MakeRef(broker(), ScopeInfoOf(node->op()));
   Node* exception = NodeProperties::GetValueInput(node, 0);
   Node* effect = NodeProperties::GetEffectInput(node);
   Node* control = NodeProperties::GetControlInput(node);
@@ -1291,7 +1294,7 @@ Reduction JSCreateLowering::ReduceJSCreateCatchContext(Node* node) {
 
 Reduction JSCreateLowering::ReduceJSCreateBlockContext(Node* node) {
   DCHECK_EQ(IrOpcode::kJSCreateBlockContext, node->opcode());
-  ScopeInfoRef scope_info(broker(), ScopeInfoOf(node->op()));
+  ScopeInfoRef scope_info = MakeRef(broker(), ScopeInfoOf(node->op()));
   int const context_length = scope_info.ContextLength();
 
   // Use inline allocation for block contexts up to a size limit.
@@ -1323,7 +1326,7 @@ base::Optional<MapRef> GetObjectCreateMap(JSHeapBroker* broker,
                                           HeapObjectRef prototype) {
   MapRef standard_map =
       broker->target_native_context().object_function().initial_map();
-  if (prototype.equals(standard_map.prototype())) {
+  if (prototype.equals(standard_map.prototype().value())) {
     return standard_map;
   }
   if (prototype.map().oddball_type() == OddballType::kNull) {
@@ -1354,7 +1357,7 @@ Reduction JSCreateLowering::ReduceJSCreateObject(Node* node) {
   if (instance_map.is_dictionary_map()) {
     DCHECK_EQ(prototype_const.map().oddball_type(), OddballType::kNull);
     // Allocate an empty NameDictionary as backing store for the properties.
-    MapRef map(broker(), factory()->name_dictionary_map());
+    MapRef map = MakeRef(broker(), factory()->name_dictionary_map());
     int capacity =
         NameDictionary::ComputeCapacity(NameDictionary::kInitialCapacity);
     DCHECK(base::bits::IsPowerOfTwo(capacity));
@@ -1430,7 +1433,7 @@ Node* JSCreateLowering::TryAllocateArguments(Node* effect, Node* control,
   auto parameters_it = parameters_access.begin_without_receiver();
 
   // Actually allocate the backing store.
-  MapRef fixed_array_map(broker(), factory()->fixed_array_map());
+  MapRef fixed_array_map = MakeRef(broker(), factory()->fixed_array_map());
   AllocationBuilder ab(jsgraph(), effect, control);
   if (!ab.CanAllocateArray(argument_count, fixed_array_map)) {
     return nullptr;
@@ -1461,7 +1464,7 @@ Node* JSCreateLowering::TryAllocateRestArguments(Node* effect, Node* control,
       parameters_access.begin_without_receiver_and_skip(start_index);
 
   // Actually allocate the backing store.
-  MapRef fixed_array_map(broker(), factory()->fixed_array_map());
+  MapRef fixed_array_map = MakeRef(broker(), factory()->fixed_array_map());
   AllocationBuilder ab(jsgraph(), effect, control);
   if (!ab.CanAllocateArray(num_elements, fixed_array_map)) {
     return nullptr;
@@ -1496,14 +1499,14 @@ Node* JSCreateLowering::TryAllocateAliasedArguments(
   int mapped_count = std::min(argument_count, parameter_count);
   *has_aliased_arguments = true;
 
-  MapRef sloppy_arguments_elements_map(
-      broker(), factory()->sloppy_arguments_elements_map());
+  MapRef sloppy_arguments_elements_map =
+      MakeRef(broker(), factory()->sloppy_arguments_elements_map());
   if (!AllocationBuilder::CanAllocateSloppyArgumentElements(
           mapped_count, sloppy_arguments_elements_map)) {
     return nullptr;
   }
 
-  MapRef fixed_array_map(broker(), factory()->fixed_array_map());
+  MapRef fixed_array_map = MakeRef(broker(), factory()->fixed_array_map());
   if (!AllocationBuilder::CanAllocateArray(argument_count, fixed_array_map)) {
     return nullptr;
   }
@@ -1561,8 +1564,8 @@ Node* JSCreateLowering::TryAllocateAliasedArguments(
   }
 
   int mapped_count = parameter_count;
-  MapRef sloppy_arguments_elements_map(
-      broker(), factory()->sloppy_arguments_elements_map());
+  MapRef sloppy_arguments_elements_map =
+      MakeRef(broker(), factory()->sloppy_arguments_elements_map());
   if (!AllocationBuilder::CanAllocateSloppyArgumentElements(
           mapped_count, sloppy_arguments_elements_map)) {
     return nullptr;
@@ -1617,7 +1620,7 @@ Node* JSCreateLowering::AllocateElements(Node* effect, Node* control,
 
   // Actually allocate the backing store.
   AllocationBuilder a(jsgraph(), effect, control);
-  a.AllocateArray(capacity, MapRef(broker(), elements_map), allocation);
+  a.AllocateArray(capacity, MakeRef(broker(), elements_map), allocation);
   for (int i = 0; i < capacity; ++i) {
     Node* index = jsgraph()->Constant(i);
     a.Store(access, index, value);
@@ -1642,7 +1645,7 @@ Node* JSCreateLowering::AllocateElements(Node* effect, Node* control,
 
   // Actually allocate the backing store.
   AllocationBuilder a(jsgraph(), effect, control);
-  a.AllocateArray(capacity, MapRef(broker(), elements_map), allocation);
+  a.AllocateArray(capacity, MakeRef(broker(), elements_map), allocation);
   for (int i = 0; i < capacity; ++i) {
     Node* index = jsgraph()->Constant(i);
     a.Store(access, index, values[i]);
@@ -1650,9 +1653,9 @@ Node* JSCreateLowering::AllocateElements(Node* effect, Node* control,
   return a.Finish();
 }
 
-Node* JSCreateLowering::AllocateFastLiteral(Node* effect, Node* control,
-                                            JSObjectRef boilerplate,
-                                            AllocationType allocation) {
+base::Optional<Node*> JSCreateLowering::TryAllocateFastLiteral(
+    Node* effect, Node* control, JSObjectRef boilerplate,
+    AllocationType allocation) {
   // Compute the in-object properties to store first (might have effects).
   MapRef boilerplate_map = boilerplate.map();
   ZoneVector<std::pair<FieldAccess, Node*>> inobject_fields(zone());
@@ -1686,15 +1689,17 @@ Node* JSCreateLowering::AllocateFastLiteral(Node* effect, Node* control,
     Node* value;
     if (boilerplate_value.IsJSObject()) {
       JSObjectRef boilerplate_object = boilerplate_value.AsJSObject();
-      value = effect =
-          AllocateFastLiteral(effect, control, boilerplate_object, allocation);
+      base::Optional<Node*> maybe_value = TryAllocateFastLiteral(
+          effect, control, boilerplate_object, allocation);
+      if (!maybe_value.has_value()) return {};
+      value = effect = maybe_value.value();
     } else if (property_details.representation().IsDouble()) {
       double number = boilerplate_value.AsHeapNumber().value();
       // Allocate a mutable HeapNumber box and store the value into it.
       AllocationBuilder builder(jsgraph(), effect, control);
       builder.Allocate(HeapNumber::kSize, allocation);
       builder.Store(AccessBuilder::ForMap(),
-                    MapRef(broker(), factory()->heap_number_map()));
+                    MakeRef(broker(), factory()->heap_number_map()));
       builder.Store(AccessBuilder::ForHeapNumberValue(),
                     jsgraph()->Constant(number));
       value = effect = builder.Finish();
@@ -1712,6 +1717,9 @@ Node* JSCreateLowering::AllocateFastLiteral(Node* effect, Node* control,
   int const boilerplate_length = boilerplate_map.GetInObjectProperties();
   for (int index = static_cast<int>(inobject_fields.size());
        index < boilerplate_length; ++index) {
+    DCHECK(!V8_MAP_PACKING_BOOL);
+    // TODO(wenyuzhao): Fix incorrect MachineType when V8_MAP_PACKING is
+    // enabled.
     FieldAccess access =
         AccessBuilder::ForJSObjectInObjectProperty(boilerplate_map, index);
     Node* value = jsgraph()->HeapConstant(factory()->one_pointer_filler_map());
@@ -1719,8 +1727,10 @@ Node* JSCreateLowering::AllocateFastLiteral(Node* effect, Node* control,
   }
 
   // Setup the elements backing store.
-  Node* elements =
-      AllocateFastLiteralElements(effect, control, boilerplate, allocation);
+  base::Optional<Node*> maybe_elements =
+      TryAllocateFastLiteralElements(effect, control, boilerplate, allocation);
+  if (!maybe_elements.has_value()) return {};
+  Node* elements = maybe_elements.value();
   if (elements->op()->EffectOutputCount() > 0) effect = elements;
 
   // Actually allocate and initialize the object.
@@ -1743,9 +1753,9 @@ Node* JSCreateLowering::AllocateFastLiteral(Node* effect, Node* control,
   return builder.Finish();
 }
 
-Node* JSCreateLowering::AllocateFastLiteralElements(Node* effect, Node* control,
-                                                    JSObjectRef boilerplate,
-                                                    AllocationType allocation) {
+base::Optional<Node*> JSCreateLowering::TryAllocateFastLiteralElements(
+    Node* effect, Node* control, JSObjectRef boilerplate,
+    AllocationType allocation) {
   FixedArrayBaseRef boilerplate_elements = boilerplate.elements().value();
 
   // Empty or copy-on-write elements just store a constant.
@@ -1764,7 +1774,7 @@ Node* JSCreateLowering::AllocateFastLiteralElements(Node* effect, Node* control,
   if (elements_map.instance_type() == FIXED_DOUBLE_ARRAY_TYPE) {
     FixedDoubleArrayRef elements = boilerplate_elements.AsFixedDoubleArray();
     for (int i = 0; i < elements_length; ++i) {
-      Float64 value = elements.get(i);
+      Float64 value = elements.GetFromImmutableFixedDoubleArray(i);
       if (value.is_hole_nan()) {
         elements_values[i] = jsgraph()->TheHoleConstant();
       } else {
@@ -1774,10 +1784,14 @@ Node* JSCreateLowering::AllocateFastLiteralElements(Node* effect, Node* control,
   } else {
     FixedArrayRef elements = boilerplate_elements.AsFixedArray();
     for (int i = 0; i < elements_length; ++i) {
-      ObjectRef element_value = elements.get(i);
+      base::Optional<ObjectRef> maybe_element_value = elements.TryGet(i);
+      if (!maybe_element_value.has_value()) return {};
+      ObjectRef element_value = maybe_element_value.value();
       if (element_value.IsJSObject()) {
-        elements_values[i] = effect = AllocateFastLiteral(
+        base::Optional<Node*> maybe_value = TryAllocateFastLiteral(
             effect, control, element_value.AsJSObject(), allocation);
+        if (!maybe_value.has_value()) return {};
+        elements_values[i] = effect = maybe_value.value();
       } else {
         elements_values[i] = jsgraph()->Constant(element_value);
       }
diff --git a/chromium/v8/src/compiler/js-create-lowering.h b/chromium/v8/src/compiler/js-create-lowering.h
index 0edbda79a0e..e780b685bff 100644
--- a/chromium/v8/src/compiler/js-create-lowering.h
+++ b/chromium/v8/src/compiler/js-create-lowering.h
@@ -97,6 +97,12 @@ class V8_EXPORT_PRIVATE JSCreateLowering final
                                     Node* arguments_length,
                                     const SharedFunctionInfoRef& shared,
                                     bool* has_aliased_arguments);
+  base::Optional<Node*> TryAllocateFastLiteral(Node* effect, Node* control,
+                                               JSObjectRef boilerplate,
+                                               AllocationType allocation);
+  base::Optional<Node*> TryAllocateFastLiteralElements(
+      Node* effect, Node* control, JSObjectRef boilerplate,
+      AllocationType allocation);
 
   Node* AllocateElements(Node* effect, Node* control,
                          ElementsKind elements_kind, int capacity,
@@ -107,11 +113,6 @@ class V8_EXPORT_PRIVATE JSCreateLowering final
                          ElementsKind elements_kind,
                          std::vector<Node*> const& values,
                          AllocationType allocation);
-  Node* AllocateFastLiteral(Node* effect, Node* control,
-                            JSObjectRef boilerplate, AllocationType allocation);
-  Node* AllocateFastLiteralElements(Node* effect, Node* control,
-                                    JSObjectRef boilerplate,
-                                    AllocationType allocation);
   Node* AllocateLiteralRegExp(Node* effect, Node* control,
                               RegExpBoilerplateDescriptionRef boilerplate);
 
diff --git a/chromium/v8/src/compiler/js-generic-lowering.cc b/chromium/v8/src/compiler/js-generic-lowering.cc
index 71a0d43a415..935581b3462 100644
--- a/chromium/v8/src/compiler/js-generic-lowering.cc
+++ b/chromium/v8/src/compiler/js-generic-lowering.cc
@@ -7,6 +7,7 @@
 #include "src/ast/ast.h"
 #include "src/builtins/builtins-constructor.h"
 #include "src/codegen/code-factory.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/js-graph.h"
@@ -715,8 +716,8 @@ void JSGenericLowering::LowerJSCreateLiteralArray(Node* node) {
 void JSGenericLowering::LowerJSGetTemplateObject(Node* node) {
   JSGetTemplateObjectNode n(node);
   GetTemplateObjectParameters const& p = n.Parameters();
-  SharedFunctionInfoRef shared(broker(), p.shared());
-  TemplateObjectDescriptionRef description(broker(), p.description());
+  SharedFunctionInfoRef shared = MakeRef(broker(), p.shared());
+  TemplateObjectDescriptionRef description = MakeRef(broker(), p.description());
 
   DCHECK_EQ(node->op()->ControlInputCount(), 1);
   node->RemoveInput(NodeProperties::FirstControlIndex(node));
@@ -1443,7 +1444,7 @@ void JSGenericLowering::LowerJSStackCheck(Node* node) {
 }
 
 void JSGenericLowering::LowerJSDebugger(Node* node) {
-  ReplaceWithBuiltinCall(node, Builtins::kHandleDebuggerStatement);
+  ReplaceWithRuntimeCall(node, Runtime::kHandleDebuggerStatement);
 }
 
 Zone* JSGenericLowering::zone() const { return graph()->zone(); }
diff --git a/chromium/v8/src/compiler/js-graph.cc b/chromium/v8/src/compiler/js-graph.cc
index aca12b4cb54..652c7391faf 100644
--- a/chromium/v8/src/compiler/js-graph.cc
+++ b/chromium/v8/src/compiler/js-graph.cc
@@ -20,7 +20,8 @@ namespace compiler {
 
 Node* JSGraph::CEntryStubConstant(int result_size, SaveFPRegsMode save_doubles,
                                   ArgvMode argv_mode, bool builtin_exit_frame) {
-  if (save_doubles == kDontSaveFPRegs && argv_mode == kArgvOnStack) {
+  if (save_doubles == SaveFPRegsMode::kIgnore &&
+      argv_mode == ArgvMode::kStack) {
     DCHECK(result_size >= 1 && result_size <= 3);
     if (!builtin_exit_frame) {
       Node** ptr = nullptr;
diff --git a/chromium/v8/src/compiler/js-graph.h b/chromium/v8/src/compiler/js-graph.h
index e86bb594bac..c38d868db47 100644
--- a/chromium/v8/src/compiler/js-graph.h
+++ b/chromium/v8/src/compiler/js-graph.h
@@ -38,10 +38,9 @@ class V8_EXPORT_PRIVATE JSGraph : public MachineGraph {
   JSGraph& operator=(const JSGraph&) = delete;
 
   // CEntryStubs are cached depending on the result size and other flags.
-  Node* CEntryStubConstant(int result_size,
-                           SaveFPRegsMode save_doubles = kDontSaveFPRegs,
-                           ArgvMode argv_mode = kArgvOnStack,
-                           bool builtin_exit_frame = false);
+  Node* CEntryStubConstant(
+      int result_size, SaveFPRegsMode save_doubles = SaveFPRegsMode::kIgnore,
+      ArgvMode argv_mode = ArgvMode::kStack, bool builtin_exit_frame = false);
 
   // Used for padding frames. (alias: the hole)
   Node* PaddingConstant() { return TheHoleConstant(); }
diff --git a/chromium/v8/src/compiler/js-heap-broker.cc b/chromium/v8/src/compiler/js-heap-broker.cc
index ac90e4c6673..13cd02ab081 100644
--- a/chromium/v8/src/compiler/js-heap-broker.cc
+++ b/chromium/v8/src/compiler/js-heap-broker.cc
@@ -4,291 +4,26 @@
 
 #include "src/compiler/js-heap-broker.h"
 
-#include "src/common/globals.h"
-#include "src/compiler/heap-refs.h"
-
 #ifdef ENABLE_SLOW_DCHECKS
 #include <algorithm>
 #endif
 
-#include "include/v8-fast-api-calls.h"
-#include "src/api/api-inl.h"
-#include "src/ast/modules.h"
 #include "src/codegen/code-factory.h"
 #include "src/codegen/optimized-compilation-info.h"
-#include "src/compiler/access-info.h"
-#include "src/compiler/graph-reducer.h"
-#include "src/compiler/per-isolate-compiler-cache.h"
-#include "src/execution/protectors-inl.h"
+#include "src/handles/handles-inl.h"
+#include "src/ic/handler-configuration.h"
 #include "src/init/bootstrapper.h"
-#include "src/objects/allocation-site-inl.h"
-#include "src/objects/api-callbacks.h"
-#include "src/objects/cell-inl.h"
-#include "src/objects/heap-number-inl.h"
-#include "src/objects/instance-type-inl.h"
-#include "src/objects/js-array-buffer-inl.h"
+#include "src/objects/feedback-cell.h"
 #include "src/objects/js-array-inl.h"
-#include "src/objects/js-regexp-inl.h"
-#include "src/objects/literal-objects-inl.h"
-#include "src/objects/module-inl.h"
 #include "src/objects/objects-inl.h"
-#include "src/objects/property-details.h"
-#include "src/objects/template-objects-inl.h"
-#include "src/objects/templates.h"
-#include "src/utils/utils.h"
+#include "src/objects/oddball.h"
+#include "src/objects/property-cell.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 #define TRACE(broker, x) TRACE_BROKER(broker, x)
-#define TRACE_MISSING(broker, x) TRACE_BROKER_MISSING(broker, x)
-
-#define FORWARD_DECL(Name) class Name##Data;
-HEAP_BROKER_SERIALIZED_OBJECT_LIST(FORWARD_DECL)
-HEAP_BROKER_POSSIBLY_BACKGROUND_SERIALIZED_OBJECT_LIST(FORWARD_DECL)
-HEAP_BROKER_BACKGROUND_SERIALIZED_OBJECT_LIST(FORWARD_DECL)
-HEAP_BROKER_NEVER_SERIALIZED_OBJECT_LIST(FORWARD_DECL)
-#undef FORWARD_DECL
-
-// There are several kinds of ObjectData values.
-//
-// kSmi: The underlying V8 object is a Smi and the data is an instance of the
-//   base class (ObjectData), i.e. it's basically just the handle.  Because the
-//   object is a Smi, it's safe to access the handle in order to extract the
-//   number value, and AsSmi() does exactly that.
-//
-// kSerializedHeapObject: The underlying V8 object is a HeapObject and the
-//   data is an instance of the corresponding (most-specific) subclass, e.g.
-//   JSFunctionData, which provides serialized information about the object.
-//
-// kBackgroundSerializedHeapObject: Like kSerializedHeapObject, but
-//   allows serialization from the background thread.
-//
-// kUnserializedHeapObject: The underlying V8 object is a HeapObject and the
-//   data is an instance of the base class (ObjectData), i.e. it basically
-//   carries no information other than the handle.
-//
-// kNeverSerializedHeapObject: The underlying V8 object is a (potentially
-//   mutable) HeapObject and the data is an instance of ObjectData. Its handle
-//   must be persistent so that the GC can update it at a safepoint. Via this
-//   handle, the object can be accessed concurrently to the main thread. To be
-//   used the flag --turbo-direct-heap-access must be on.
-//
-// kUnserializedReadOnlyHeapObject: The underlying V8 object is a read-only
-//   HeapObject and the data is an instance of ObjectData. For
-//   ReadOnlyHeapObjects, it is OK to access heap even from off-thread, so
-//   these objects need not be serialized.
-enum ObjectDataKind {
-  kSmi,
-  kSerializedHeapObject,
-  kBackgroundSerializedHeapObject,
-  kUnserializedHeapObject,
-  kNeverSerializedHeapObject,
-  kUnserializedReadOnlyHeapObject
-};
-
-namespace {
-bool IsReadOnlyHeapObject(Object object) {
-  DisallowGarbageCollection no_gc;
-  return (object.IsCode() && Code::cast(object).is_builtin()) ||
-         (object.IsHeapObject() &&
-          ReadOnlyHeap::Contains(HeapObject::cast(object)));
-}
-
-template <class T>
-constexpr bool IsSerializedHeapObject() {
-  return false;
-}
-
-#define DEFINE_MARKER(Name)                       \
-  template <>                                     \
-  constexpr bool IsSerializedHeapObject<Name>() { \
-    return true;                                  \
-  }                                               \
-  STATIC_ASSERT(IsSerializedHeapObject<Name>());
-HEAP_BROKER_SERIALIZED_OBJECT_LIST(DEFINE_MARKER)
-#undef DEFINE_MARKER
-}  // namespace
-
-class ObjectData : public ZoneObject {
- public:
-  ObjectData(JSHeapBroker* broker, ObjectData** storage, Handle<Object> object,
-             ObjectDataKind kind)
-      : object_(object), kind_(kind) {
-    // This assignment ensures we don't end up inserting the same object
-    // in an endless recursion.
-    *storage = this;
-
-    TRACE(broker, "Creating data " << this << " for handle " << object.address()
-                                   << " (" << Brief(*object) << ")");
-
-    // It is safe to access read only heap objects and builtins from a
-    // background thread. When we read fileds of these objects, we may create
-    // ObjectData on the background thread even without a canonical handle
-    // scope. This is safe too since we don't create handles but just get
-    // handles from read only root table or builtins table which is what
-    // canonical scope uses as well. For all other objects we should have
-    // created ObjectData in canonical handle scope on the main thread.
-    CHECK_IMPLIES(
-        broker->mode() == JSHeapBroker::kDisabled ||
-            broker->mode() == JSHeapBroker::kSerializing,
-        broker->isolate()->handle_scope_data()->canonical_scope != nullptr);
-    CHECK_IMPLIES(broker->mode() == JSHeapBroker::kSerialized,
-                  kind == kUnserializedReadOnlyHeapObject || kind == kSmi ||
-                      kind == kNeverSerializedHeapObject ||
-                      kind == kBackgroundSerializedHeapObject);
-    CHECK_IMPLIES(kind == kUnserializedReadOnlyHeapObject,
-                  IsReadOnlyHeapObject(*object));
-  }
-
-#define DECLARE_IS(Name) bool Is##Name() const;
-  HEAP_BROKER_SERIALIZED_OBJECT_LIST(DECLARE_IS)
-  HEAP_BROKER_POSSIBLY_BACKGROUND_SERIALIZED_OBJECT_LIST(DECLARE_IS)
-  HEAP_BROKER_BACKGROUND_SERIALIZED_OBJECT_LIST(DECLARE_IS)
-  HEAP_BROKER_NEVER_SERIALIZED_OBJECT_LIST(DECLARE_IS)
-#undef DECLARE_IS
-
-#define DECLARE_AS(Name) Name##Data* As##Name();
-  HEAP_BROKER_SERIALIZED_OBJECT_LIST(DECLARE_AS)
-  HEAP_BROKER_POSSIBLY_BACKGROUND_SERIALIZED_OBJECT_LIST(DECLARE_AS)
-  HEAP_BROKER_BACKGROUND_SERIALIZED_OBJECT_LIST(DECLARE_AS)
-  HEAP_BROKER_NEVER_SERIALIZED_OBJECT_LIST(DECLARE_AS)
-#undef DECLARE_AS
-
-  Handle<Object> object() const { return object_; }
-  ObjectDataKind kind() const { return kind_; }
-  bool is_smi() const { return kind_ == kSmi; }
-  bool should_access_heap() const {
-    return kind_ == kUnserializedHeapObject ||
-           kind_ == kNeverSerializedHeapObject ||
-           kind_ == kUnserializedReadOnlyHeapObject;
-  }
-  bool IsNull() const { return object_->IsNull(); }
-
-#ifdef DEBUG
-  enum class Usage{kUnused, kOnlyIdentityUsed, kDataUsed};
-  mutable Usage used_status = Usage::kUnused;
-#endif  // DEBUG
-
- private:
-  Handle<Object> const object_;
-  ObjectDataKind const kind_;
-};
-
-class HeapObjectData : public ObjectData {
- public:
-  HeapObjectData(JSHeapBroker* broker, ObjectData** storage,
-                 Handle<HeapObject> object,
-                 ObjectDataKind kind = ObjectDataKind::kSerializedHeapObject);
-
-  bool boolean_value() const { return boolean_value_; }
-  ObjectData* map() const { return map_; }
-  InstanceType GetMapInstanceType() const;
-
-  static HeapObjectData* Serialize(JSHeapBroker* broker,
-                                   Handle<HeapObject> object);
-
- private:
-  bool const boolean_value_;
-  ObjectData* const map_;
-};
-
-class PropertyCellData : public HeapObjectData {
- public:
-  PropertyCellData(JSHeapBroker* broker, ObjectData** storage,
-                   Handle<PropertyCell> object,
-                   ObjectDataKind kind = ObjectDataKind::kSerializedHeapObject);
-
-  bool Serialize(JSHeapBroker* broker);
-
-  PropertyDetails property_details() const {
-    CHECK(serialized());
-    return property_details_;
-  }
-
-  ObjectData* value() const {
-    DCHECK(serialized());
-    return value_;
-  }
-
- private:
-  PropertyDetails property_details_ = PropertyDetails::Empty();
-  ObjectData* value_ = nullptr;
-
-  bool serialized() const { return value_ != nullptr; }
-};
-
-// TODO(mslekova): Once we have real-world usage data, we might want to
-// reimplement this as sorted vector instead, to reduce the memory overhead.
-typedef ZoneMap<ObjectData*, HolderLookupResult> KnownReceiversMap;
-
-class FunctionTemplateInfoData : public HeapObjectData {
- public:
-  FunctionTemplateInfoData(JSHeapBroker* broker, ObjectData** storage,
-                           Handle<FunctionTemplateInfo> object);
-
-  bool is_signature_undefined() const { return is_signature_undefined_; }
-  bool accept_any_receiver() const { return accept_any_receiver_; }
-  bool has_call_code() const { return has_call_code_; }
-
-  void SerializeCallCode(JSHeapBroker* broker);
-  ObjectData* call_code() const { return call_code_; }
-  Address c_function() const { return c_function_; }
-  const CFunctionInfo* c_signature() const { return c_signature_; }
-  KnownReceiversMap& known_receivers() { return known_receivers_; }
-
- private:
-  bool is_signature_undefined_ = false;
-  bool accept_any_receiver_ = false;
-  bool has_call_code_ = false;
-
-  ObjectData* call_code_ = nullptr;
-  const Address c_function_;
-  const CFunctionInfo* const c_signature_;
-  KnownReceiversMap known_receivers_;
-};
-
-class CallHandlerInfoData : public HeapObjectData {
- public:
-  CallHandlerInfoData(JSHeapBroker* broker, ObjectData** storage,
-                      Handle<CallHandlerInfo> object);
-
-  Address callback() const { return callback_; }
-
-  void Serialize(JSHeapBroker* broker);
-  ObjectData* data() const { return data_; }
-
- private:
-  Address const callback_;
-
-  ObjectData* data_ = nullptr;
-};
-
-FunctionTemplateInfoData::FunctionTemplateInfoData(
-    JSHeapBroker* broker, ObjectData** storage,
-    Handle<FunctionTemplateInfo> object)
-    : HeapObjectData(broker, storage, object),
-      c_function_(v8::ToCData<Address>(object->GetCFunction())),
-      c_signature_(v8::ToCData<CFunctionInfo*>(object->GetCSignature())),
-      known_receivers_(broker->zone()) {
-  DCHECK(!FLAG_turbo_direct_heap_access);
-  auto function_template_info = Handle<FunctionTemplateInfo>::cast(object);
-  is_signature_undefined_ =
-      function_template_info->signature().IsUndefined(broker->isolate());
-  accept_any_receiver_ = function_template_info->accept_any_receiver();
-
-  CallOptimization call_optimization(broker->isolate(), object);
-  has_call_code_ = call_optimization.is_simple_api_call();
-}
-
-CallHandlerInfoData::CallHandlerInfoData(JSHeapBroker* broker,
-                                         ObjectData** storage,
-                                         Handle<CallHandlerInfo> object)
-    : HeapObjectData(broker, storage, object),
-      callback_(v8::ToCData<Address>(object->callback())) {
-  DCHECK(!FLAG_turbo_direct_heap_access);
-}
 
 // These definitions are here in order to please the linker, which in debug mode
 // sometimes requires static constants to be defined in .cc files.
@@ -299,2243 +34,6 @@ void JSHeapBroker::IncrementTracingIndentation() { ++trace_indentation_; }
 
 void JSHeapBroker::DecrementTracingIndentation() { --trace_indentation_; }
 
-PropertyCellData::PropertyCellData(JSHeapBroker* broker, ObjectData** storage,
-                                   Handle<PropertyCell> object,
-                                   ObjectDataKind kind)
-    : HeapObjectData(broker, storage, object, kind) {}
-
-bool PropertyCellData::Serialize(JSHeapBroker* broker) {
-  if (serialized()) return true;
-
-  TraceScope tracer(broker, this, "PropertyCellData::Serialize");
-  auto cell = Handle<PropertyCell>::cast(object());
-
-  // While this code runs on a background thread, the property cell might
-  // undergo state transitions via calls to PropertyCell::Transition. These
-  // transitions follow a certain protocol on which we rely here to ensure that
-  // we only report success when we can guarantee consistent data. A key
-  // property is that after transitioning from cell type A to B (A != B), there
-  // will never be a transition back to A, unless A is kConstant and the new
-  // value is the hole (i.e. the property cell was invalidated, which is a final
-  // state).
-
-  PropertyDetails property_details = cell->property_details(kAcquireLoad);
-
-  Handle<Object> value =
-      broker->CanonicalPersistentHandle(cell->value(kAcquireLoad));
-  if (broker->ObjectMayBeUninitialized(value)) {
-    DCHECK(!broker->IsMainThread());
-    return false;
-  }
-
-  {
-    PropertyDetails property_details_again =
-        cell->property_details(kAcquireLoad);
-    if (property_details != property_details_again) {
-      DCHECK(!broker->IsMainThread());
-      return false;
-    }
-  }
-
-  if (property_details.cell_type() == PropertyCellType::kConstant) {
-    Handle<Object> value_again =
-        broker->CanonicalPersistentHandle(cell->value(kAcquireLoad));
-    if (*value != *value_again) {
-      DCHECK(!broker->IsMainThread());
-      return false;
-    }
-  }
-
-  ObjectData* value_data = broker->TryGetOrCreateData(value, false);
-  if (value_data == nullptr) {
-    DCHECK(!broker->IsMainThread());
-    return false;
-  }
-
-  PropertyCell::CheckDataIsCompatible(property_details, *value);
-
-  DCHECK(!serialized());
-  property_details_ = property_details;
-  value_ = value_data;
-  DCHECK(serialized());
-  return true;
-}
-
-void FunctionTemplateInfoData::SerializeCallCode(JSHeapBroker* broker) {
-  if (call_code_ != nullptr) return;
-
-  TraceScope tracer(broker, this,
-                    "FunctionTemplateInfoData::SerializeCallCode");
-  auto function_template_info = Handle<FunctionTemplateInfo>::cast(object());
-  call_code_ =
-      broker->GetOrCreateData(function_template_info->call_code(kAcquireLoad));
-  if (call_code_->should_access_heap()) {
-    // TODO(mvstanton): When ObjectRef is in the never serialized list, this
-    // code can be removed.
-    broker->GetOrCreateData(
-        Handle<CallHandlerInfo>::cast(call_code_->object())->data());
-  } else {
-    call_code_->AsCallHandlerInfo()->Serialize(broker);
-  }
-}
-
-void CallHandlerInfoData::Serialize(JSHeapBroker* broker) {
-  if (data_ != nullptr) return;
-
-  TraceScope tracer(broker, this, "CallHandlerInfoData::Serialize");
-  auto call_handler_info = Handle<CallHandlerInfo>::cast(object());
-  data_ = broker->GetOrCreateData(call_handler_info->data());
-}
-
-class JSReceiverData : public HeapObjectData {
- public:
-  JSReceiverData(JSHeapBroker* broker, ObjectData** storage,
-                 Handle<JSReceiver> object)
-      : HeapObjectData(broker, storage, object) {}
-};
-
-class JSObjectData : public JSReceiverData {
- public:
-  JSObjectData(JSHeapBroker* broker, ObjectData** storage,
-               Handle<JSObject> object);
-
-  // Recursive serialization of all reachable JSObjects.
-  void SerializeAsBoilerplate(JSHeapBroker* broker);
-  ObjectData* GetInobjectField(int property_index) const;
-
-  // Shallow serialization of {elements}.
-  void SerializeElements(JSHeapBroker* broker);
-  bool serialized_elements() const { return serialized_elements_; }
-  ObjectData* elements() const;
-
-  void SerializeObjectCreateMap(JSHeapBroker* broker);
-
-  ObjectData* object_create_map(
-      JSHeapBroker* broker) const {  // Can be nullptr.
-    if (!serialized_object_create_map_) {
-      DCHECK_NULL(object_create_map_);
-      TRACE_MISSING(broker, "object_create_map on " << this);
-    }
-    return object_create_map_;
-  }
-
-  ObjectData* GetOwnConstantElement(
-      JSHeapBroker* broker, uint32_t index,
-      SerializationPolicy policy = SerializationPolicy::kAssumeSerialized);
-  ObjectData* GetOwnFastDataProperty(
-      JSHeapBroker* broker, Representation representation,
-      FieldIndex field_index,
-      SerializationPolicy policy = SerializationPolicy::kAssumeSerialized);
-  ObjectData* GetOwnDictionaryProperty(JSHeapBroker* broker,
-                                       InternalIndex dict_index,
-                                       SerializationPolicy policy);
-
-  // This method is only used to assert our invariants.
-  bool cow_or_empty_elements_tenured() const;
-
- private:
-  void SerializeRecursiveAsBoilerplate(JSHeapBroker* broker, int max_depths);
-
-  ObjectData* elements_ = nullptr;
-  bool cow_or_empty_elements_tenured_ = false;
-  // The {serialized_as_boilerplate} flag is set when all recursively
-  // reachable JSObjects are serialized.
-  bool serialized_as_boilerplate_ = false;
-  bool serialized_elements_ = false;
-
-  ZoneVector<ObjectData*> inobject_fields_;
-
-  bool serialized_object_create_map_ = false;
-  ObjectData* object_create_map_ = nullptr;
-
-  // Elements (indexed properties) that either
-  // (1) are known to exist directly on the object as non-writable and
-  // non-configurable, or (2) are known not to (possibly they don't exist at
-  // all). In case (2), the second pair component is nullptr.
-  ZoneVector<std::pair<uint32_t, ObjectData*>> own_constant_elements_;
-  // Properties that either:
-  // (1) are known to exist directly on the object, or
-  // (2) are known not to (possibly they don't exist at all).
-  // In case (2), the second pair component is nullptr.
-  // For simplicity, this may in theory overlap with inobject_fields_.
-  // For fast mode objects, the keys of the map are the property_index() values
-  // of the respective property FieldIndex'es. For slow mode objects, the keys
-  // are the dictionary indicies.
-  ZoneUnorderedMap<int, ObjectData*> own_properties_;
-};
-
-void JSObjectData::SerializeObjectCreateMap(JSHeapBroker* broker) {
-  if (serialized_object_create_map_) return;
-  serialized_object_create_map_ = true;
-
-  TraceScope tracer(broker, this, "JSObjectData::SerializeObjectCreateMap");
-  Handle<JSObject> jsobject = Handle<JSObject>::cast(object());
-
-  if (jsobject->map().is_prototype_map()) {
-    Handle<Object> maybe_proto_info(jsobject->map().prototype_info(),
-                                    broker->isolate());
-    if (maybe_proto_info->IsPrototypeInfo()) {
-      auto proto_info = Handle<PrototypeInfo>::cast(maybe_proto_info);
-      if (proto_info->HasObjectCreateMap()) {
-        DCHECK_NULL(object_create_map_);
-        object_create_map_ =
-            broker->GetOrCreateData(proto_info->ObjectCreateMap());
-      }
-    }
-  }
-}
-
-namespace {
-
-base::Optional<ObjectRef> GetOwnElementFromHeap(JSHeapBroker* broker,
-                                                Handle<Object> receiver,
-                                                uint32_t index,
-                                                bool constant_only) {
-  LookupIterator it(broker->isolate(), receiver, index, LookupIterator::OWN);
-  if (it.state() == LookupIterator::DATA &&
-      (!constant_only || (it.IsReadOnly() && !it.IsConfigurable()))) {
-    return ObjectRef(broker,
-                     broker->CanonicalPersistentHandle(it.GetDataValue()));
-  }
-  return base::nullopt;
-}
-
-ObjectRef GetOwnFastDataPropertyFromHeap(JSHeapBroker* broker,
-                                         Handle<JSObject> receiver,
-                                         Representation representation,
-                                         FieldIndex field_index) {
-  Handle<Object> constant =
-      JSObject::FastPropertyAt(receiver, representation, field_index);
-  return ObjectRef(broker, constant);
-}
-
-ObjectRef GetOwnDictionaryPropertyFromHeap(JSHeapBroker* broker,
-                                           Handle<JSObject> receiver,
-                                           InternalIndex dict_index) {
-  Handle<Object> constant =
-      JSObject::DictionaryPropertyAt(receiver, dict_index);
-  return ObjectRef(broker, constant);
-}
-
-}  // namespace
-
-ObjectData* JSObjectData::GetOwnConstantElement(JSHeapBroker* broker,
-                                                uint32_t index,
-                                                SerializationPolicy policy) {
-  for (auto const& p : own_constant_elements_) {
-    if (p.first == index) return p.second;
-  }
-
-  if (policy == SerializationPolicy::kAssumeSerialized) {
-    TRACE_MISSING(broker, "knowledge about index " << index << " on " << this);
-    return nullptr;
-  }
-
-  base::Optional<ObjectRef> element =
-      GetOwnElementFromHeap(broker, object(), index, true);
-  ObjectData* result = element.has_value() ? element->data() : nullptr;
-  own_constant_elements_.push_back({index, result});
-  return result;
-}
-
-ObjectData* JSObjectData::GetOwnFastDataProperty(JSHeapBroker* broker,
-                                                 Representation representation,
-                                                 FieldIndex field_index,
-                                                 SerializationPolicy policy) {
-  auto p = own_properties_.find(field_index.property_index());
-  if (p != own_properties_.end()) return p->second;
-
-  if (policy == SerializationPolicy::kAssumeSerialized) {
-    TRACE_MISSING(broker, "knowledge about fast property with index "
-                              << field_index.property_index() << " on "
-                              << this);
-    return nullptr;
-  }
-
-  ObjectRef property = GetOwnFastDataPropertyFromHeap(
-      broker, Handle<JSObject>::cast(object()), representation, field_index);
-  ObjectData* result(property.data());
-  own_properties_.insert(std::make_pair(field_index.property_index(), result));
-  return result;
-}
-
-ObjectData* JSObjectData::GetOwnDictionaryProperty(JSHeapBroker* broker,
-                                                   InternalIndex dict_index,
-                                                   SerializationPolicy policy) {
-  auto p = own_properties_.find(dict_index.as_int());
-  if (p != own_properties_.end()) return p->second;
-
-  if (policy == SerializationPolicy::kAssumeSerialized) {
-    TRACE_MISSING(broker, "knowledge about dictionary property with index "
-                              << dict_index.as_int() << " on " << this);
-    return nullptr;
-  }
-
-  ObjectRef property = GetOwnDictionaryPropertyFromHeap(
-      broker, Handle<JSObject>::cast(object()), dict_index);
-  ObjectData* result(property.data());
-  own_properties_.insert(std::make_pair(dict_index.as_int(), result));
-  return result;
-}
-
-class JSTypedArrayData : public JSObjectData {
- public:
-  JSTypedArrayData(JSHeapBroker* broker, ObjectData** storage,
-                   Handle<JSTypedArray> object)
-      : JSObjectData(broker, storage, object) {}
-
-  // TODO(v8:7790): Once JSObject is no longer serialized, also make
-  // JSTypedArrayRef never-serialized.
-  STATIC_ASSERT(IsSerializedHeapObject<JSObject>());
-
-  void Serialize(JSHeapBroker* broker);
-  bool serialized() const { return serialized_; }
-
-  bool is_on_heap() const { return is_on_heap_; }
-  size_t length() const { return length_; }
-  void* data_ptr() const { return data_ptr_; }
-
-  ObjectData* buffer() const { return buffer_; }
-
- private:
-  bool serialized_ = false;
-  bool is_on_heap_ = false;
-  size_t length_ = 0;
-  void* data_ptr_ = nullptr;
-  ObjectData* buffer_ = nullptr;
-};
-
-void JSTypedArrayData::Serialize(JSHeapBroker* broker) {
-  if (serialized_) return;
-  serialized_ = true;
-
-  TraceScope tracer(broker, this, "JSTypedArrayData::Serialize");
-  Handle<JSTypedArray> typed_array = Handle<JSTypedArray>::cast(object());
-
-  is_on_heap_ = typed_array->is_on_heap();
-  length_ = typed_array->length();
-  data_ptr_ = typed_array->DataPtr();
-
-  if (!is_on_heap()) {
-    DCHECK_NULL(buffer_);
-    buffer_ = broker->GetOrCreateData(typed_array->buffer());
-  }
-}
-
-class ArrayBoilerplateDescriptionData : public HeapObjectData {
- public:
-  ArrayBoilerplateDescriptionData(JSHeapBroker* broker, ObjectData** storage,
-                                  Handle<ArrayBoilerplateDescription> object)
-      : HeapObjectData(broker, storage, object),
-        constants_elements_length_(object->constant_elements().length()) {
-    DCHECK(!FLAG_turbo_direct_heap_access);
-  }
-
-  int constants_elements_length() const { return constants_elements_length_; }
-
- private:
-  int const constants_elements_length_;
-};
-
-class ObjectBoilerplateDescriptionData : public HeapObjectData {
- public:
-  ObjectBoilerplateDescriptionData(JSHeapBroker* broker, ObjectData** storage,
-                                   Handle<ObjectBoilerplateDescription> object)
-      : HeapObjectData(broker, storage, object), size_(object->size()) {
-    DCHECK(!FLAG_turbo_direct_heap_access);
-  }
-
-  int size() const { return size_; }
-
- private:
-  int const size_;
-};
-
-class JSDataViewData : public JSObjectData {
- public:
-  JSDataViewData(JSHeapBroker* broker, ObjectData** storage,
-                 Handle<JSDataView> object);
-
-  size_t byte_length() const { return byte_length_; }
-
- private:
-  size_t const byte_length_;
-};
-
-class JSBoundFunctionData : public JSObjectData {
- public:
-  JSBoundFunctionData(JSHeapBroker* broker, ObjectData** storage,
-                      Handle<JSBoundFunction> object);
-
-  bool Serialize(JSHeapBroker* broker);
-  bool serialized() const { return serialized_; }
-
-  ObjectData* bound_target_function() const {
-    DCHECK(!FLAG_turbo_direct_heap_access);
-    return bound_target_function_;
-  }
-  ObjectData* bound_this() const {
-    DCHECK(!FLAG_turbo_direct_heap_access);
-    return bound_this_;
-  }
-  ObjectData* bound_arguments() const {
-    DCHECK(!FLAG_turbo_direct_heap_access);
-    return bound_arguments_;
-  }
-
- private:
-  bool serialized_ = false;
-
-  ObjectData* bound_target_function_ = nullptr;
-  ObjectData* bound_this_ = nullptr;
-  ObjectData* bound_arguments_ = nullptr;
-};
-
-class JSFunctionData : public JSObjectData {
- public:
-  JSFunctionData(JSHeapBroker* broker, ObjectData** storage,
-                 Handle<JSFunction> object);
-
-  bool has_feedback_vector() const { return has_feedback_vector_; }
-  bool has_initial_map() const { return has_initial_map_; }
-  bool has_prototype() const { return has_prototype_; }
-  bool PrototypeRequiresRuntimeLookup() const {
-    return PrototypeRequiresRuntimeLookup_;
-  }
-
-  void Serialize(JSHeapBroker* broker);
-  bool serialized() const { return serialized_; }
-
-  void SerializeCodeAndFeedback(JSHeapBroker* broker);
-  bool serialized_code_and_feedback() const {
-    return serialized_code_and_feedback_;
-  }
-
-  ObjectData* context() const { return context_; }
-  ObjectData* native_context() const { return native_context_; }
-  ObjectData* initial_map() const { return initial_map_; }
-  ObjectData* prototype() const { return prototype_; }
-  ObjectData* shared() const { return shared_; }
-  ObjectData* raw_feedback_cell() const {
-    DCHECK(serialized_code_and_feedback());
-    return feedback_cell_;
-  }
-  ObjectData* feedback_vector() const {
-    DCHECK(serialized_code_and_feedback());
-    return feedback_vector_;
-  }
-  ObjectData* code() const {
-    DCHECK(serialized_code_and_feedback());
-    DCHECK(!FLAG_turbo_direct_heap_access);
-    return code_;
-  }
-  int initial_map_instance_size_with_min_slack() const {
-    CHECK(serialized_);
-    return initial_map_instance_size_with_min_slack_;
-  }
-
- private:
-  bool has_feedback_vector_;
-  bool has_initial_map_;
-  bool has_prototype_;
-  bool PrototypeRequiresRuntimeLookup_;
-
-  bool serialized_ = false;
-  bool serialized_code_and_feedback_ = false;
-
-  ObjectData* context_ = nullptr;
-  ObjectData* native_context_ = nullptr;
-  ObjectData* initial_map_ = nullptr;
-  ObjectData* prototype_ = nullptr;
-  ObjectData* shared_ = nullptr;
-  ObjectData* feedback_vector_ = nullptr;
-  ObjectData* feedback_cell_ = nullptr;
-  ObjectData* code_ = nullptr;
-  int initial_map_instance_size_with_min_slack_;
-};
-
-class RegExpBoilerplateDescriptionData : public HeapObjectData {
- public:
-  RegExpBoilerplateDescriptionData(JSHeapBroker* broker, ObjectData** storage,
-                                   Handle<RegExpBoilerplateDescription> object)
-      : HeapObjectData(broker, storage, object) {}
-
-  void Serialize(JSHeapBroker* broker);
-  ObjectData* data() const {
-    CHECK(serialized_);
-    return data_;
-  }
-  ObjectData* source() const {
-    CHECK(serialized_);
-    return source_;
-  }
-  int flags() const {
-    CHECK(serialized_);
-    return flags_;
-  }
-
- private:
-  bool serialized_ = false;
-  ObjectData* data_ = nullptr;
-  ObjectData* source_ = nullptr;
-  int flags_;
-};
-
-class HeapNumberData : public HeapObjectData {
- public:
-  HeapNumberData(JSHeapBroker* broker, ObjectData** storage,
-                 Handle<HeapNumber> object,
-                 ObjectDataKind kind = ObjectDataKind::kSerializedHeapObject)
-      : HeapObjectData(broker, storage, object, kind),
-        value_(object->value()) {}
-
-  double value() const { return value_; }
-
- private:
-  double const value_;
-};
-
-class ContextData : public HeapObjectData {
- public:
-  ContextData(JSHeapBroker* broker, ObjectData** storage,
-              Handle<Context> object);
-
-  ObjectData* previous(
-      JSHeapBroker* broker,
-      SerializationPolicy policy = SerializationPolicy::kAssumeSerialized);
-
-  // Returns nullptr if the slot index isn't valid or wasn't serialized,
-  // unless {policy} is {kSerializeIfNeeded}.
-  ObjectData* GetSlot(
-      JSHeapBroker* broker, int index,
-      SerializationPolicy policy = SerializationPolicy::kAssumeSerialized);
-
- private:
-  ZoneMap<int, ObjectData*> slots_;
-  ObjectData* previous_ = nullptr;
-};
-
-ContextData::ContextData(JSHeapBroker* broker, ObjectData** storage,
-                         Handle<Context> object)
-    : HeapObjectData(broker, storage, object), slots_(broker->zone()) {}
-
-ObjectData* ContextData::previous(JSHeapBroker* broker,
-                                  SerializationPolicy policy) {
-  if (policy == SerializationPolicy::kSerializeIfNeeded &&
-      previous_ == nullptr) {
-    TraceScope tracer(broker, this, "ContextData::previous");
-    Handle<Context> context = Handle<Context>::cast(object());
-    previous_ = broker->GetOrCreateData(context->unchecked_previous());
-  }
-  return previous_;
-}
-
-ObjectData* ContextData::GetSlot(JSHeapBroker* broker, int index,
-                                 SerializationPolicy policy) {
-  CHECK_GE(index, 0);
-  auto search = slots_.find(index);
-  if (search != slots_.end()) {
-    return search->second;
-  }
-
-  if (policy == SerializationPolicy::kSerializeIfNeeded) {
-    Handle<Context> context = Handle<Context>::cast(object());
-    if (index < context->length()) {
-      TraceScope tracer(broker, this, "ContextData::GetSlot");
-      TRACE(broker, "Serializing context slot " << index);
-      ObjectData* odata = broker->GetOrCreateData(context->get(index));
-      slots_.insert(std::make_pair(index, odata));
-      return odata;
-    }
-  }
-
-  return nullptr;
-}
-
-class NativeContextData : public ContextData {
- public:
-#define DECL_ACCESSOR(type, name) \
-  ObjectData* name() const { return name##_; }
-  BROKER_NATIVE_CONTEXT_FIELDS(DECL_ACCESSOR)
-#undef DECL_ACCESSOR
-
-  const ZoneVector<ObjectData*>& function_maps() const {
-    CHECK_NE(state_, State::kUnserialized);
-    return function_maps_;
-  }
-
-  ObjectData* scope_info() const {
-    CHECK_NE(state_, State::kUnserialized);
-    return scope_info_;
-  }
-
-  NativeContextData(JSHeapBroker* broker, ObjectData** storage,
-                    Handle<NativeContext> object);
-  void Serialize(JSHeapBroker* broker);
-  void SerializeOnBackground(JSHeapBroker* broker);
-
- private:
-  // After Serialize is called the class is partially serialized and it the
-  // kSerializedOnMainThread state. It then becomes kFullySerialized once
-  // SerializeOnBackground is called.
-  enum class State { kUnserialized, kSerializedOnMainThread, kFullySerialized };
-  State state_;
-
-#define DECL_MEMBER(type, name) ObjectData* name##_ = nullptr;
-  BROKER_NATIVE_CONTEXT_FIELDS(DECL_MEMBER)
-#undef DECL_MEMBER
-  ZoneVector<ObjectData*> function_maps_;
-  ObjectData* scope_info_ = nullptr;
-};
-
-class NameData : public HeapObjectData {
- public:
-  NameData(JSHeapBroker* broker, ObjectData** storage, Handle<Name> object)
-      : HeapObjectData(broker, storage, object) {
-    DCHECK(!FLAG_turbo_direct_heap_access);
-  }
-};
-
-class StringData : public NameData {
- public:
-  StringData(JSHeapBroker* broker, ObjectData** storage, Handle<String> object);
-
-  int length() const { return length_; }
-  uint16_t first_char() const { return first_char_; }
-  base::Optional<double> to_number() const { return to_number_; }
-  bool is_external_string() const { return is_external_string_; }
-  bool is_seq_string() const { return is_seq_string_; }
-
-  ObjectData* GetCharAsStringOrUndefined(
-      JSHeapBroker* broker, uint32_t index,
-      SerializationPolicy policy = SerializationPolicy::kAssumeSerialized);
-
- private:
-  int const length_;
-  uint16_t const first_char_;
-  base::Optional<double> to_number_;
-  bool const is_external_string_;
-  bool const is_seq_string_;
-
-  // Known individual characters as strings, corresponding to the semantics of
-  // element access (s[i]). The first pair component is always less than
-  // {length_}. The second component is never nullptr.
-  ZoneVector<std::pair<uint32_t, ObjectData*>> chars_as_strings_;
-};
-
-class SymbolData : public NameData {
- public:
-  SymbolData(JSHeapBroker* broker, ObjectData** storage, Handle<Symbol> object)
-      : NameData(broker, storage, object) {
-    DCHECK(!FLAG_turbo_direct_heap_access);
-  }
-};
-
-StringData::StringData(JSHeapBroker* broker, ObjectData** storage,
-                       Handle<String> object)
-    : NameData(broker, storage, object),
-      length_(object->length()),
-      first_char_(length_ > 0 ? object->Get(0) : 0),
-      to_number_(TryStringToDouble(broker->local_isolate(), object)),
-      is_external_string_(object->IsExternalString()),
-      is_seq_string_(object->IsSeqString()),
-      chars_as_strings_(broker->zone()) {
-  DCHECK(!FLAG_turbo_direct_heap_access);
-}
-
-class InternalizedStringData : public StringData {
- public:
-  InternalizedStringData(JSHeapBroker* broker, ObjectData** storage,
-                         Handle<InternalizedString> object)
-      : StringData(broker, storage, object) {
-    DCHECK(!FLAG_turbo_direct_heap_access);
-  }
-};
-
-ObjectData* StringData::GetCharAsStringOrUndefined(JSHeapBroker* broker,
-                                                   uint32_t index,
-                                                   SerializationPolicy policy) {
-  if (index >= static_cast<uint32_t>(length())) return nullptr;
-
-  for (auto const& p : chars_as_strings_) {
-    if (p.first == index) return p.second;
-  }
-
-  if (policy == SerializationPolicy::kAssumeSerialized) {
-    TRACE_MISSING(broker, "knowledge about index " << index << " on " << this);
-    return nullptr;
-  }
-
-  base::Optional<ObjectRef> element =
-      GetOwnElementFromHeap(broker, object(), index, true);
-  ObjectData* result = element.has_value() ? element->data() : nullptr;
-  chars_as_strings_.push_back({index, result});
-  return result;
-}
-
-namespace {
-
-bool IsFastLiteralHelper(Handle<JSObject> boilerplate, int max_depth,
-                         int* max_properties) {
-  DCHECK_GE(max_depth, 0);
-  DCHECK_GE(*max_properties, 0);
-
-  Isolate* const isolate = boilerplate->GetIsolate();
-
-  // Make sure the boilerplate map is not deprecated.
-  if (!JSObject::TryMigrateInstance(isolate, boilerplate)) return false;
-
-  // Check for too deep nesting.
-  if (max_depth == 0) return false;
-
-  // Check the elements.
-  Handle<FixedArrayBase> elements(boilerplate->elements(), isolate);
-  if (elements->length() > 0 &&
-      elements->map() != ReadOnlyRoots(isolate).fixed_cow_array_map()) {
-    if (boilerplate->HasSmiOrObjectElements()) {
-      Handle<FixedArray> fast_elements = Handle<FixedArray>::cast(elements);
-      int length = elements->length();
-      for (int i = 0; i < length; i++) {
-        if ((*max_properties)-- == 0) return false;
-        Handle<Object> value(fast_elements->get(i), isolate);
-        if (value->IsJSObject()) {
-          Handle<JSObject> value_object = Handle<JSObject>::cast(value);
-          if (!IsFastLiteralHelper(value_object, max_depth - 1,
-                                   max_properties)) {
-            return false;
-          }
-        }
-      }
-    } else if (boilerplate->HasDoubleElements()) {
-      if (elements->Size() > kMaxRegularHeapObjectSize) return false;
-    } else {
-      return false;
-    }
-  }
-
-  // TODO(turbofan): Do we want to support out-of-object properties?
-  if (!(boilerplate->HasFastProperties() &&
-        boilerplate->property_array().length() == 0)) {
-    return false;
-  }
-
-  // Check the in-object properties.
-  Handle<DescriptorArray> descriptors(
-      boilerplate->map().instance_descriptors(isolate, kRelaxedLoad), isolate);
-  for (InternalIndex i : boilerplate->map().IterateOwnDescriptors()) {
-    PropertyDetails details = descriptors->GetDetails(i);
-    if (details.location() != kField) continue;
-    DCHECK_EQ(kData, details.kind());
-    if ((*max_properties)-- == 0) return false;
-    FieldIndex field_index = FieldIndex::ForDescriptor(boilerplate->map(), i);
-    Handle<Object> value(boilerplate->RawFastPropertyAt(field_index), isolate);
-    if (value->IsJSObject()) {
-      Handle<JSObject> value_object = Handle<JSObject>::cast(value);
-      if (!IsFastLiteralHelper(value_object, max_depth - 1, max_properties)) {
-        return false;
-      }
-    }
-  }
-  return true;
-}
-
-// Maximum depth and total number of elements and properties for literal
-// graphs to be considered for fast deep-copying. The limit is chosen to
-// match the maximum number of inobject properties, to ensure that the
-// performance of using object literals is not worse than using constructor
-// functions, see crbug.com/v8/6211 for details.
-const int kMaxFastLiteralDepth = 3;
-const int kMaxFastLiteralProperties = JSObject::kMaxInObjectProperties;
-
-// Determines whether the given array or object literal boilerplate satisfies
-// all limits to be considered for fast deep-copying and computes the total
-// size of all objects that are part of the graph.
-bool IsInlinableFastLiteral(Handle<JSObject> boilerplate) {
-  int max_properties = kMaxFastLiteralProperties;
-  return IsFastLiteralHelper(boilerplate, kMaxFastLiteralDepth,
-                             &max_properties);
-}
-
-}  // namespace
-
-class AccessorInfoData : public HeapObjectData {
- public:
-  AccessorInfoData(JSHeapBroker* broker, ObjectData** storage,
-                   Handle<AccessorInfo> object);
-};
-
-class AllocationSiteData : public HeapObjectData {
- public:
-  AllocationSiteData(JSHeapBroker* broker, ObjectData** storage,
-                     Handle<AllocationSite> object);
-  void SerializeBoilerplate(JSHeapBroker* broker);
-
-  bool PointsToLiteral() const { return PointsToLiteral_; }
-  AllocationType GetAllocationType() const { return GetAllocationType_; }
-  ObjectData* nested_site() const { return nested_site_; }
-  bool IsFastLiteral() const { return IsFastLiteral_; }
-  ObjectData* boilerplate() const { return boilerplate_; }
-
-  // These are only valid if PointsToLiteral is false.
-  ElementsKind GetElementsKind() const { return GetElementsKind_; }
-  bool CanInlineCall() const { return CanInlineCall_; }
-
- private:
-  bool const PointsToLiteral_;
-  AllocationType const GetAllocationType_;
-  ObjectData* nested_site_ = nullptr;
-  bool IsFastLiteral_ = false;
-  ObjectData* boilerplate_ = nullptr;
-  ElementsKind GetElementsKind_ = NO_ELEMENTS;
-  bool CanInlineCall_ = false;
-  bool serialized_boilerplate_ = false;
-};
-
-class BigIntData : public HeapObjectData {
- public:
-  BigIntData(JSHeapBroker* broker, ObjectData** storage, Handle<BigInt> object,
-             ObjectDataKind kind = ObjectDataKind::kSerializedHeapObject)
-      : HeapObjectData(broker, storage, object, kind),
-        as_uint64_(object->AsUint64(nullptr)) {}
-
-  uint64_t AsUint64() const { return as_uint64_; }
-
- private:
-  const uint64_t as_uint64_;
-};
-
-// Only used in JSNativeContextSpecialization.
-class ScriptContextTableData : public HeapObjectData {
- public:
-  ScriptContextTableData(JSHeapBroker* broker, ObjectData** storage,
-                         Handle<ScriptContextTable> object)
-      : HeapObjectData(broker, storage, object) {}
-};
-
-struct PropertyDescriptor {
-  ObjectData* key = nullptr;
-  ObjectData* value = nullptr;
-  PropertyDetails details = PropertyDetails::Empty();
-  FieldIndex field_index;
-  ObjectData* field_owner = nullptr;
-  ObjectData* field_type = nullptr;
-};
-
-class MapData : public HeapObjectData {
- public:
-  MapData(JSHeapBroker* broker, ObjectData** storage, Handle<Map> object,
-          ObjectDataKind kind = ObjectDataKind::kSerializedHeapObject);
-
-  InstanceType instance_type() const { return instance_type_; }
-  int instance_size() const { return instance_size_; }
-  byte bit_field() const { return bit_field_; }
-  byte bit_field2() const { return bit_field2_; }
-  uint32_t bit_field3() const { return bit_field3_; }
-  bool can_be_deprecated() const { return can_be_deprecated_; }
-  bool can_transition() const { return can_transition_; }
-  int in_object_properties_start_in_words() const {
-    CHECK(InstanceTypeChecker::IsJSObject(instance_type()));
-    return in_object_properties_start_in_words_;
-  }
-  int in_object_properties() const {
-    CHECK(InstanceTypeChecker::IsJSObject(instance_type()));
-    return in_object_properties_;
-  }
-  int constructor_function_index() const { return constructor_function_index_; }
-  int NextFreePropertyIndex() const { return next_free_property_index_; }
-  int UnusedPropertyFields() const { return unused_property_fields_; }
-  bool supports_fast_array_iteration() const {
-    return supports_fast_array_iteration_;
-  }
-  bool supports_fast_array_resize() const {
-    return supports_fast_array_resize_;
-  }
-  bool is_abandoned_prototype_map() const {
-    return is_abandoned_prototype_map_;
-  }
-
-  // Extra information.
-
-  void SerializeElementsKindGeneralizations(JSHeapBroker* broker);
-  const ZoneVector<ObjectData*>& elements_kind_generalizations() const {
-    CHECK(serialized_elements_kind_generalizations_);
-    return elements_kind_generalizations_;
-  }
-
-  // Serialize a single (or all) own slot(s) of the descriptor array and recurse
-  // on field owner(s).
-  void SerializeOwnDescriptor(JSHeapBroker* broker,
-                              InternalIndex descriptor_index);
-  void SerializeOwnDescriptors(JSHeapBroker* broker);
-  ObjectData* GetStrongValue(InternalIndex descriptor_index) const;
-  ObjectData* instance_descriptors() const { return instance_descriptors_; }
-
-  void SerializeRootMap(JSHeapBroker* broker);
-  ObjectData* FindRootMap() const;
-
-  void SerializeConstructor(JSHeapBroker* broker);
-  ObjectData* GetConstructor() const {
-    CHECK(serialized_constructor_);
-    return constructor_;
-  }
-
-  void SerializeBackPointer(JSHeapBroker* broker);
-  ObjectData* GetBackPointer() const {
-    CHECK(serialized_backpointer_);
-    return backpointer_;
-  }
-
-  void SerializePrototype(JSHeapBroker* broker);
-  bool serialized_prototype() const { return serialized_prototype_; }
-  ObjectData* prototype() const {
-    CHECK(serialized_prototype_);
-    return prototype_;
-  }
-
-  void SerializeForElementLoad(JSHeapBroker* broker);
-
-  void SerializeForElementStore(JSHeapBroker* broker);
-
- private:
-  InstanceType const instance_type_;
-  int const instance_size_;
-  byte const bit_field_;
-  byte const bit_field2_;
-  uint32_t const bit_field3_;
-  bool const can_be_deprecated_;
-  bool const can_transition_;
-  int const in_object_properties_start_in_words_;
-  int const in_object_properties_;
-  int const constructor_function_index_;
-  int const next_free_property_index_;
-  int const unused_property_fields_;
-  bool const supports_fast_array_iteration_;
-  bool const supports_fast_array_resize_;
-  bool const is_abandoned_prototype_map_;
-
-  bool serialized_elements_kind_generalizations_ = false;
-  ZoneVector<ObjectData*> elements_kind_generalizations_;
-
-  bool serialized_own_descriptors_ = false;
-  ObjectData* instance_descriptors_ = nullptr;
-
-  bool serialized_constructor_ = false;
-  ObjectData* constructor_ = nullptr;
-
-  bool serialized_backpointer_ = false;
-  ObjectData* backpointer_ = nullptr;
-
-  bool serialized_prototype_ = false;
-  ObjectData* prototype_ = nullptr;
-
-  bool serialized_root_map_ = false;
-  ObjectData* root_map_ = nullptr;
-
-  bool serialized_for_element_load_ = false;
-
-  bool serialized_for_element_store_ = false;
-};
-
-AccessorInfoData::AccessorInfoData(JSHeapBroker* broker, ObjectData** storage,
-                                   Handle<AccessorInfo> object)
-    : HeapObjectData(broker, storage, object) {
-  DCHECK(!FLAG_turbo_direct_heap_access);
-}
-
-AllocationSiteData::AllocationSiteData(JSHeapBroker* broker,
-                                       ObjectData** storage,
-                                       Handle<AllocationSite> object)
-    : HeapObjectData(broker, storage, object),
-      PointsToLiteral_(object->PointsToLiteral()),
-      GetAllocationType_(object->GetAllocationType()) {
-  if (PointsToLiteral_) {
-    IsFastLiteral_ = IsInlinableFastLiteral(
-        handle(object->boilerplate(), broker->isolate()));
-  } else {
-    GetElementsKind_ = object->GetElementsKind();
-    CanInlineCall_ = object->CanInlineCall();
-  }
-}
-
-void AllocationSiteData::SerializeBoilerplate(JSHeapBroker* broker) {
-  if (serialized_boilerplate_) return;
-  serialized_boilerplate_ = true;
-
-  TraceScope tracer(broker, this, "AllocationSiteData::SerializeBoilerplate");
-  Handle<AllocationSite> site = Handle<AllocationSite>::cast(object());
-
-  CHECK(IsFastLiteral_);
-  DCHECK_NULL(boilerplate_);
-  boilerplate_ = broker->GetOrCreateData(site->boilerplate());
-  if (!boilerplate_->should_access_heap()) {
-    boilerplate_->AsJSObject()->SerializeAsBoilerplate(broker);
-  }
-
-  DCHECK_NULL(nested_site_);
-  nested_site_ = broker->GetOrCreateData(site->nested_site());
-  if (nested_site_->IsAllocationSite() && !nested_site_->should_access_heap()) {
-    nested_site_->AsAllocationSite()->SerializeBoilerplate(broker);
-  }
-}
-
-HeapObjectData::HeapObjectData(JSHeapBroker* broker, ObjectData** storage,
-                               Handle<HeapObject> object, ObjectDataKind kind)
-    : ObjectData(broker, storage, object, kind),
-      boolean_value_(object->BooleanValue(broker->isolate())),
-      // We have to use a raw cast below instead of AsMap() because of
-      // recursion. AsMap() would call IsMap(), which accesses the
-      // instance_type_ member. In the case of constructing the MapData for the
-      // meta map (whose map is itself), this member has not yet been
-      // initialized.
-      map_(broker->GetOrCreateData(object->map())) {
-  CHECK_IMPLIES(kind == kSerializedHeapObject,
-                broker->mode() == JSHeapBroker::kSerializing);
-  CHECK_IMPLIES(broker->mode() == JSHeapBroker::kSerialized,
-                    kind == kBackgroundSerializedHeapObject);
-}
-
-InstanceType HeapObjectData::GetMapInstanceType() const {
-  ObjectData* map_data = map();
-  if (map_data->should_access_heap()) {
-    return Handle<Map>::cast(map_data->object())->instance_type();
-  }
-  return map_data->AsMap()->instance_type();
-}
-
-namespace {
-bool IsReadOnlyLengthDescriptor(Isolate* isolate, Handle<Map> jsarray_map) {
-  DCHECK(!jsarray_map->is_dictionary_map());
-  Handle<Name> length_string = isolate->factory()->length_string();
-  DescriptorArray descriptors =
-      jsarray_map->instance_descriptors(isolate, kRelaxedLoad);
-  // TODO(jkummerow): We could skip the search and hardcode number == 0.
-  InternalIndex number = descriptors.Search(*length_string, *jsarray_map);
-  DCHECK(number.is_found());
-  return descriptors.GetDetails(number).IsReadOnly();
-}
-
-bool SupportsFastArrayIteration(Isolate* isolate, Handle<Map> map) {
-  return map->instance_type() == JS_ARRAY_TYPE &&
-         IsFastElementsKind(map->elements_kind()) &&
-         map->prototype().IsJSArray() &&
-         isolate->IsAnyInitialArrayPrototype(JSArray::cast(map->prototype())) &&
-         Protectors::IsNoElementsIntact(isolate);
-}
-
-bool SupportsFastArrayResize(Isolate* isolate, Handle<Map> map) {
-  return SupportsFastArrayIteration(isolate, map) && map->is_extensible() &&
-         !map->is_dictionary_map() && !IsReadOnlyLengthDescriptor(isolate, map);
-}
-}  // namespace
-
-MapData::MapData(JSHeapBroker* broker, ObjectData** storage, Handle<Map> object,
-                 ObjectDataKind kind)
-    : HeapObjectData(broker, storage, object, kind),
-      instance_type_(object->instance_type()),
-      instance_size_(object->instance_size()),
-      // We read the bit_field as relaxed since `has_non_instance_prototype` can
-      // be modified in live objects, and because we serialize some maps on the
-      // background. Those background-serialized maps are the native context's
-      // maps for which this bit is "set" but it doesn't change value (i.e. it
-      // is set to false when it was already false).
-      bit_field_(object->relaxed_bit_field()),
-      bit_field2_(object->bit_field2()),
-      bit_field3_(object->bit_field3()),
-      can_be_deprecated_(object->NumberOfOwnDescriptors() > 0
-                             ? object->CanBeDeprecated()
-                             : false),
-      can_transition_(object->CanTransition()),
-      in_object_properties_start_in_words_(
-          object->IsJSObjectMap() ? object->GetInObjectPropertiesStartInWords()
-                                  : 0),
-      in_object_properties_(
-          object->IsJSObjectMap() ? object->GetInObjectProperties() : 0),
-      constructor_function_index_(object->IsPrimitiveMap()
-                                      ? object->GetConstructorFunctionIndex()
-                                      : Map::kNoConstructorFunctionIndex),
-      next_free_property_index_(object->NextFreePropertyIndex()),
-      unused_property_fields_(object->UnusedPropertyFields()),
-      supports_fast_array_iteration_(
-          SupportsFastArrayIteration(broker->isolate(), object)),
-      supports_fast_array_resize_(
-          SupportsFastArrayResize(broker->isolate(), object)),
-      is_abandoned_prototype_map_(object->is_abandoned_prototype_map()),
-      elements_kind_generalizations_(broker->zone()) {}
-
-JSFunctionData::JSFunctionData(JSHeapBroker* broker, ObjectData** storage,
-                               Handle<JSFunction> object)
-    : JSObjectData(broker, storage, object),
-      has_feedback_vector_(object->has_feedback_vector()),
-      has_initial_map_(object->has_prototype_slot() &&
-                       object->has_initial_map()),
-      has_prototype_(object->has_prototype_slot() && object->has_prototype()),
-      PrototypeRequiresRuntimeLookup_(
-          object->PrototypeRequiresRuntimeLookup()) {}
-
-void JSFunctionData::Serialize(JSHeapBroker* broker) {
-  if (serialized_) return;
-  serialized_ = true;
-
-  TraceScope tracer(broker, this, "JSFunctionData::Serialize");
-  Handle<JSFunction> function = Handle<JSFunction>::cast(object());
-
-  DCHECK_NULL(context_);
-  DCHECK_NULL(native_context_);
-  DCHECK_NULL(initial_map_);
-  DCHECK_NULL(prototype_);
-  DCHECK_NULL(shared_);
-
-  context_ = broker->GetOrCreateData(function->context());
-  native_context_ = broker->GetOrCreateData(function->native_context());
-  shared_ = broker->GetOrCreateData(function->shared());
-
-  initial_map_ = has_initial_map()
-                     ? broker->GetOrCreateData(function->initial_map())
-                     : nullptr;
-  prototype_ = has_prototype() ? broker->GetOrCreateData(function->prototype())
-                               : nullptr;
-
-  if (initial_map_ != nullptr) {
-    initial_map_instance_size_with_min_slack_ =
-        function->ComputeInstanceSizeWithMinSlack(broker->isolate());
-  }
-  if (initial_map_ != nullptr && !initial_map_->should_access_heap()) {
-    if (initial_map_->AsMap()->instance_type() == JS_ARRAY_TYPE) {
-      initial_map_->AsMap()->SerializeElementsKindGeneralizations(broker);
-    }
-    initial_map_->AsMap()->SerializeConstructor(broker);
-    // TODO(neis): This is currently only needed for native_context's
-    // object_function, as used by GetObjectCreateMap. If no further use sites
-    // show up, we should move this into NativeContextData::Serialize.
-    initial_map_->AsMap()->SerializePrototype(broker);
-  }
-}
-
-void JSFunctionData::SerializeCodeAndFeedback(JSHeapBroker* broker) {
-  DCHECK(serialized_);
-  if (serialized_code_and_feedback_) return;
-  serialized_code_and_feedback_ = true;
-
-  TraceScope tracer(broker, this, "JSFunctionData::SerializeCodeAndFeedback");
-  Handle<JSFunction> function = Handle<JSFunction>::cast(object());
-
-  DCHECK_NULL(feedback_cell_);
-  DCHECK_NULL(feedback_vector_);
-  DCHECK_NULL(code_);
-  if (!FLAG_turbo_direct_heap_access) {
-    // This is conditionalized because Code objects are never serialized now.
-    // We only need to represent the code object in serialized data when
-    // we're unable to perform direct heap accesses.
-    code_ = broker->GetOrCreateData(function->code(kAcquireLoad));
-  }
-  feedback_cell_ = broker->GetOrCreateData(function->raw_feedback_cell());
-  feedback_vector_ = has_feedback_vector()
-                         ? broker->GetOrCreateData(function->feedback_vector())
-                         : nullptr;
-}
-
-void MapData::SerializeElementsKindGeneralizations(JSHeapBroker* broker) {
-  if (serialized_elements_kind_generalizations_) return;
-  serialized_elements_kind_generalizations_ = true;
-
-  TraceScope tracer(broker, this,
-                    "MapData::SerializeElementsKindGeneralizations");
-  DCHECK_EQ(instance_type(), JS_ARRAY_TYPE);
-  MapRef self(broker, this);
-  ElementsKind from_kind = self.elements_kind();
-  DCHECK(elements_kind_generalizations_.empty());
-  for (int i = FIRST_FAST_ELEMENTS_KIND; i <= LAST_FAST_ELEMENTS_KIND; i++) {
-    ElementsKind to_kind = static_cast<ElementsKind>(i);
-    if (IsMoreGeneralElementsKindTransition(from_kind, to_kind)) {
-      Handle<Map> target =
-          Map::AsElementsKind(broker->isolate(), self.object(), to_kind);
-      elements_kind_generalizations_.push_back(broker->GetOrCreateData(target));
-    }
-  }
-}
-
-class DescriptorArrayData : public HeapObjectData {
- public:
-  DescriptorArrayData(JSHeapBroker* broker, ObjectData** storage,
-                      Handle<DescriptorArray> object)
-      : HeapObjectData(broker, storage, object), contents_(broker->zone()) {
-    DCHECK(!FLAG_turbo_direct_heap_access);
-  }
-
-  ObjectData* FindFieldOwner(InternalIndex descriptor_index) const {
-    return contents_.at(descriptor_index.as_int()).field_owner;
-  }
-
-  PropertyDetails GetPropertyDetails(InternalIndex descriptor_index) const {
-    return contents_.at(descriptor_index.as_int()).details;
-  }
-
-  ObjectData* GetPropertyKey(InternalIndex descriptor_index) const {
-    return contents_.at(descriptor_index.as_int()).key;
-  }
-
-  FieldIndex GetFieldIndexFor(InternalIndex descriptor_index) const {
-    return contents_.at(descriptor_index.as_int()).field_index;
-  }
-
-  ObjectData* GetFieldType(InternalIndex descriptor_index) const {
-    return contents_.at(descriptor_index.as_int()).field_type;
-  }
-
-  ObjectData* GetStrongValue(InternalIndex descriptor_index) const {
-    return contents_.at(descriptor_index.as_int()).value;
-  }
-
-  bool serialized_descriptor(InternalIndex descriptor_index) const {
-    return contents_.find(descriptor_index.as_int()) != contents_.end();
-  }
-
-  void SerializeDescriptor(JSHeapBroker* broker, Handle<Map> map,
-                           InternalIndex descriptor_index);
-
- private:
-  ZoneMap<int, PropertyDescriptor> contents_;
-};
-
-void DescriptorArrayData::SerializeDescriptor(JSHeapBroker* broker,
-                                              Handle<Map> map,
-                                              InternalIndex descriptor_index) {
-  CHECK_LT(descriptor_index.as_int(), map->NumberOfOwnDescriptors());
-  if (contents_.find(descriptor_index.as_int()) != contents_.end()) return;
-
-  Isolate* const isolate = broker->isolate();
-  auto descriptors = Handle<DescriptorArray>::cast(object());
-  CHECK_EQ(*descriptors, map->instance_descriptors(isolate));
-
-  PropertyDescriptor d;
-  d.key = broker->GetOrCreateData(descriptors->GetKey(descriptor_index));
-  MaybeObject value = descriptors->GetValue(descriptor_index);
-  HeapObject obj;
-  if (value.GetHeapObjectIfStrong(&obj)) {
-    d.value = broker->GetOrCreateData(obj);
-  }
-  d.details = descriptors->GetDetails(descriptor_index);
-  if (d.details.location() == kField) {
-    d.field_index = FieldIndex::ForDescriptor(*map, descriptor_index);
-    d.field_owner =
-        broker->GetOrCreateData(map->FindFieldOwner(isolate, descriptor_index));
-    d.field_type =
-        broker->GetOrCreateData(descriptors->GetFieldType(descriptor_index));
-  }
-  contents_[descriptor_index.as_int()] = d;
-
-  if (d.details.location() == kField && !d.field_owner->should_access_heap()) {
-    // Recurse on the owner map.
-    d.field_owner->AsMap()->SerializeOwnDescriptor(broker, descriptor_index);
-  }
-
-  TRACE(broker, "Copied descriptor " << descriptor_index.as_int() << " into "
-                                     << this << " (" << contents_.size()
-                                     << " total)");
-}
-
-class FeedbackCellData : public HeapObjectData {
- public:
-  FeedbackCellData(JSHeapBroker* broker, ObjectData** storage,
-                   Handle<FeedbackCell> object);
-
-  ObjectData* value() const { return value_; }
-
- private:
-  ObjectData* const value_;
-};
-
-FeedbackCellData::FeedbackCellData(JSHeapBroker* broker, ObjectData** storage,
-                                   Handle<FeedbackCell> object)
-    : HeapObjectData(broker, storage, object),
-      value_(object->value().IsFeedbackVector()
-                 ? broker->GetOrCreateData(object->value())
-                 : nullptr) {
-  DCHECK(!FLAG_turbo_direct_heap_access);
-}
-
-class FeedbackVectorData : public HeapObjectData {
- public:
-  FeedbackVectorData(JSHeapBroker* broker, ObjectData** storage,
-                     Handle<FeedbackVector> object);
-
-  double invocation_count() const { return invocation_count_; }
-
-  ObjectData* shared_function_info() {
-    CHECK(serialized_);
-    return shared_function_info_;
-  }
-
-  void Serialize(JSHeapBroker* broker);
-  bool serialized() const { return serialized_; }
-  ObjectData* GetClosureFeedbackCell(JSHeapBroker* broker, int index) const;
-
- private:
-  double const invocation_count_;
-
-  bool serialized_ = false;
-  ObjectData* shared_function_info_;
-  ZoneVector<ObjectData*> closure_feedback_cell_array_;
-};
-
-FeedbackVectorData::FeedbackVectorData(JSHeapBroker* broker,
-                                       ObjectData** storage,
-                                       Handle<FeedbackVector> object)
-    : HeapObjectData(broker, storage, object),
-      invocation_count_(object->invocation_count()),
-      closure_feedback_cell_array_(broker->zone()) {
-  DCHECK(!FLAG_turbo_direct_heap_access);
-}
-
-ObjectData* FeedbackVectorData::GetClosureFeedbackCell(JSHeapBroker* broker,
-                                                       int index) const {
-  CHECK_GE(index, 0);
-
-  size_t cell_array_size = closure_feedback_cell_array_.size();
-  if (!serialized_) {
-    DCHECK_EQ(cell_array_size, 0);
-    TRACE_BROKER_MISSING(broker,
-                         " closure feedback cell array for vector " << this);
-    return nullptr;
-  }
-  CHECK_LT(index, cell_array_size);
-  return closure_feedback_cell_array_[index];
-}
-
-void FeedbackVectorData::Serialize(JSHeapBroker* broker) {
-  if (serialized_) return;
-  serialized_ = true;
-
-  TraceScope tracer(broker, this, "FeedbackVectorData::Serialize");
-  Handle<FeedbackVector> vector = Handle<FeedbackVector>::cast(object());
-  Handle<SharedFunctionInfo> sfi(vector->shared_function_info(),
-                                 broker->isolate());
-  shared_function_info_ = broker->GetOrCreateData(sfi);
-  DCHECK(closure_feedback_cell_array_.empty());
-  int length = vector->closure_feedback_cell_array().length();
-  closure_feedback_cell_array_.reserve(length);
-  for (int i = 0; i < length; ++i) {
-    Handle<FeedbackCell> cell = vector->GetClosureFeedbackCell(i);
-    ObjectData* cell_data = broker->GetOrCreateData(cell);
-    closure_feedback_cell_array_.push_back(cell_data);
-  }
-  TRACE(broker, "Copied " << length << " feedback cells");
-}
-
-class FixedArrayBaseData : public HeapObjectData {
- public:
-  FixedArrayBaseData(JSHeapBroker* broker, ObjectData** storage,
-                     Handle<FixedArrayBase> object)
-      : HeapObjectData(broker, storage, object), length_(object->length()) {}
-
-  int length() const { return length_; }
-
- private:
-  int const length_;
-};
-
-class FixedArrayData : public FixedArrayBaseData {
- public:
-  FixedArrayData(JSHeapBroker* broker, ObjectData** storage,
-                 Handle<FixedArray> object);
-
-  // Creates all elements of the fixed array.
-  void SerializeContents(JSHeapBroker* broker);
-
-  ObjectData* Get(int i) const;
-
- private:
-  bool serialized_contents_ = false;
-  ZoneVector<ObjectData*> contents_;
-};
-
-JSDataViewData::JSDataViewData(JSHeapBroker* broker, ObjectData** storage,
-                               Handle<JSDataView> object)
-    : JSObjectData(broker, storage, object),
-      byte_length_(object->byte_length()) {}
-
-JSBoundFunctionData::JSBoundFunctionData(JSHeapBroker* broker,
-                                         ObjectData** storage,
-                                         Handle<JSBoundFunction> object)
-    : JSObjectData(broker, storage, object) {}
-
-bool JSBoundFunctionData::Serialize(JSHeapBroker* broker) {
-  if (serialized_) return true;
-  if (broker->StackHasOverflowed()) return false;
-
-  TraceScope tracer(broker, this, "JSBoundFunctionData::Serialize");
-  Handle<JSBoundFunction> function = Handle<JSBoundFunction>::cast(object());
-
-  // We don't immediately set {serialized_} in order to correctly handle the
-  // case where a recursive call to this method reaches the stack limit.
-
-  DCHECK_NULL(bound_target_function_);
-  bound_target_function_ =
-      broker->GetOrCreateData(function->bound_target_function());
-  bool serialized_nested = true;
-  if (!bound_target_function_->should_access_heap()) {
-    if (bound_target_function_->IsJSBoundFunction()) {
-      serialized_nested =
-          bound_target_function_->AsJSBoundFunction()->Serialize(broker);
-    } else if (bound_target_function_->IsJSFunction()) {
-      bound_target_function_->AsJSFunction()->Serialize(broker);
-    }
-  }
-  if (!serialized_nested) {
-    // We couldn't serialize all nested bound functions due to stack
-    // overflow. Give up.
-    DCHECK(!serialized_);
-    bound_target_function_ = nullptr;  // Reset to sync with serialized_.
-    return false;
-  }
-
-  serialized_ = true;
-
-  DCHECK_NULL(bound_arguments_);
-  bound_arguments_ = broker->GetOrCreateData(function->bound_arguments());
-  if (!bound_arguments_->should_access_heap()) {
-    bound_arguments_->AsFixedArray()->SerializeContents(broker);
-  }
-
-  DCHECK_NULL(bound_this_);
-  bound_this_ = broker->GetOrCreateData(function->bound_this());
-
-  return true;
-}
-
-JSObjectData::JSObjectData(JSHeapBroker* broker, ObjectData** storage,
-                           Handle<JSObject> object)
-    : JSReceiverData(broker, storage, object),
-      inobject_fields_(broker->zone()),
-      own_constant_elements_(broker->zone()),
-      own_properties_(broker->zone()) {}
-
-FixedArrayData::FixedArrayData(JSHeapBroker* broker, ObjectData** storage,
-                               Handle<FixedArray> object)
-    : FixedArrayBaseData(broker, storage, object), contents_(broker->zone()) {}
-
-void FixedArrayData::SerializeContents(JSHeapBroker* broker) {
-  if (serialized_contents_) return;
-  serialized_contents_ = true;
-
-  TraceScope tracer(broker, this, "FixedArrayData::SerializeContents");
-  Handle<FixedArray> array = Handle<FixedArray>::cast(object());
-  CHECK_EQ(array->length(), length());
-  CHECK(contents_.empty());
-  contents_.reserve(static_cast<size_t>(length()));
-
-  for (int i = 0; i < length(); i++) {
-    Handle<Object> value(array->get(i), broker->isolate());
-    contents_.push_back(broker->GetOrCreateData(value));
-  }
-  TRACE(broker, "Copied " << contents_.size() << " elements");
-}
-
-class FixedDoubleArrayData : public FixedArrayBaseData {
- public:
-  FixedDoubleArrayData(JSHeapBroker* broker, ObjectData** storage,
-                       Handle<FixedDoubleArray> object);
-
-  // Serializes all elements of the fixed array.
-  void SerializeContents(JSHeapBroker* broker);
-
-  Float64 Get(int i) const;
-
- private:
-  bool serialized_contents_ = false;
-  ZoneVector<Float64> contents_;
-};
-
-FixedDoubleArrayData::FixedDoubleArrayData(JSHeapBroker* broker,
-                                           ObjectData** storage,
-                                           Handle<FixedDoubleArray> object)
-    : FixedArrayBaseData(broker, storage, object), contents_(broker->zone()) {}
-
-void FixedDoubleArrayData::SerializeContents(JSHeapBroker* broker) {
-  if (serialized_contents_) return;
-  serialized_contents_ = true;
-
-  TraceScope tracer(broker, this, "FixedDoubleArrayData::SerializeContents");
-  Handle<FixedDoubleArray> self = Handle<FixedDoubleArray>::cast(object());
-  CHECK_EQ(self->length(), length());
-  CHECK(contents_.empty());
-  contents_.reserve(static_cast<size_t>(length()));
-
-  for (int i = 0; i < length(); i++) {
-    contents_.push_back(Float64::FromBits(self->get_representation(i)));
-  }
-  TRACE(broker, "Copied " << contents_.size() << " elements");
-}
-
-class BytecodeArrayData : public FixedArrayBaseData {
- public:
-  int register_count() const { return register_count_; }
-  int parameter_count() const { return parameter_count_; }
-  interpreter::Register incoming_new_target_or_generator_register() const {
-    return incoming_new_target_or_generator_register_;
-  }
-
-  BytecodeArrayData(JSHeapBroker* broker, ObjectData** storage,
-                    Handle<BytecodeArray> object)
-      : FixedArrayBaseData(broker, storage, object),
-        register_count_(object->register_count()),
-        parameter_count_(object->parameter_count()),
-        incoming_new_target_or_generator_register_(
-            object->incoming_new_target_or_generator_register()) {}
-
- private:
-  int const register_count_;
-  int const parameter_count_;
-  interpreter::Register const incoming_new_target_or_generator_register_;
-};
-
-class JSArrayData : public JSObjectData {
- public:
-  JSArrayData(JSHeapBroker* broker, ObjectData** storage,
-              Handle<JSArray> object);
-
-  void Serialize(JSHeapBroker* broker);
-  ObjectData* length() const {
-    CHECK(serialized_);
-    return length_;
-  }
-
-  ObjectData* GetOwnElement(
-      JSHeapBroker* broker, uint32_t index,
-      SerializationPolicy policy = SerializationPolicy::kAssumeSerialized);
-
- private:
-  bool serialized_ = false;
-  ObjectData* length_ = nullptr;
-
-  // Elements (indexed properties) that either
-  // (1) are known to exist directly on the object, or
-  // (2) are known not to (possibly they don't exist at all).
-  // In case (2), the second pair component is nullptr.
-  ZoneVector<std::pair<uint32_t, ObjectData*>> own_elements_;
-};
-
-JSArrayData::JSArrayData(JSHeapBroker* broker, ObjectData** storage,
-                         Handle<JSArray> object)
-    : JSObjectData(broker, storage, object), own_elements_(broker->zone()) {}
-
-void JSArrayData::Serialize(JSHeapBroker* broker) {
-  CHECK(!FLAG_turbo_direct_heap_access);
-
-  if (serialized_) return;
-  serialized_ = true;
-
-  TraceScope tracer(broker, this, "JSArrayData::Serialize");
-  Handle<JSArray> jsarray = Handle<JSArray>::cast(object());
-
-  DCHECK_NULL(length_);
-  length_ = broker->GetOrCreateData(jsarray->length());
-}
-
-ObjectData* JSArrayData::GetOwnElement(JSHeapBroker* broker, uint32_t index,
-                                       SerializationPolicy policy) {
-  for (auto const& p : own_elements_) {
-    if (p.first == index) return p.second;
-  }
-
-  if (policy == SerializationPolicy::kAssumeSerialized) {
-    TRACE_MISSING(broker, "knowledge about index " << index << " on " << this);
-    return nullptr;
-  }
-
-  base::Optional<ObjectRef> element =
-      GetOwnElementFromHeap(broker, object(), index, false);
-  ObjectData* result = element.has_value() ? element->data() : nullptr;
-  own_elements_.push_back({index, result});
-  return result;
-}
-
-class ScopeInfoData : public HeapObjectData {
- public:
-  ScopeInfoData(JSHeapBroker* broker, ObjectData** storage,
-                Handle<ScopeInfo> object);
-
-  int ContextLength() const { return context_length_; }
-  bool HasContextExtensionSlot() const { return has_context_extension_slot_; }
-  bool HasOuterScopeInfo() const { return has_outer_scope_info_; }
-
-  ObjectData* OuterScopeInfo() const { return outer_scope_info_; }
-  void SerializeScopeInfoChain(JSHeapBroker* broker);
-
- private:
-  int const context_length_;
-  bool const has_context_extension_slot_;
-  bool const has_outer_scope_info_;
-
-  // Only serialized via SerializeScopeInfoChain.
-  ObjectData* outer_scope_info_;
-};
-
-ScopeInfoData::ScopeInfoData(JSHeapBroker* broker, ObjectData** storage,
-                             Handle<ScopeInfo> object)
-    : HeapObjectData(broker, storage, object),
-      context_length_(object->ContextLength()),
-      has_context_extension_slot_(object->HasContextExtensionSlot()),
-      has_outer_scope_info_(object->HasOuterScopeInfo()),
-      outer_scope_info_(nullptr) {
-  DCHECK(!FLAG_turbo_direct_heap_access);
-}
-
-void ScopeInfoData::SerializeScopeInfoChain(JSHeapBroker* broker) {
-  if (outer_scope_info_) return;
-  if (!has_outer_scope_info_) return;
-  outer_scope_info_ = broker->GetOrCreateData(
-      Handle<ScopeInfo>::cast(object())->OuterScopeInfo());
-  if (!outer_scope_info_->should_access_heap()) {
-    outer_scope_info_->AsScopeInfo()->SerializeScopeInfoChain(broker);
-  }
-}
-
-class SharedFunctionInfoData : public HeapObjectData {
- public:
-  SharedFunctionInfoData(JSHeapBroker* broker, ObjectData** storage,
-                         Handle<SharedFunctionInfo> object);
-
-  int builtin_id() const { return builtin_id_; }
-  int context_header_size() const { return context_header_size_; }
-  ObjectData* GetBytecodeArray() const { return GetBytecodeArray_; }
-  SharedFunctionInfo::Inlineability GetInlineability() const {
-    return inlineability_;
-  }
-  void SerializeFunctionTemplateInfo(JSHeapBroker* broker);
-  ObjectData* scope_info() const { return scope_info_; }
-  void SerializeScopeInfoChain(JSHeapBroker* broker);
-  ObjectData* function_template_info() const { return function_template_info_; }
-  ObjectData* GetTemplateObject(FeedbackSlot slot) const {
-    auto lookup_it = template_objects_.find(slot.ToInt());
-    if (lookup_it != template_objects_.cend()) {
-      return lookup_it->second;
-    }
-    return nullptr;
-  }
-  void SetTemplateObject(FeedbackSlot slot, ObjectData* object) {
-    CHECK(
-        template_objects_.insert(std::make_pair(slot.ToInt(), object)).second);
-  }
-
-#define DECL_ACCESSOR(type, name) \
-  type name() const { return name##_; }
-  BROKER_SFI_FIELDS(DECL_ACCESSOR)
-#undef DECL_ACCESSOR
-
- private:
-  int const builtin_id_;
-  int const context_header_size_;
-  ObjectData* const GetBytecodeArray_;
-#define DECL_MEMBER(type, name) type const name##_;
-  BROKER_SFI_FIELDS(DECL_MEMBER)
-#undef DECL_MEMBER
-  SharedFunctionInfo::Inlineability const inlineability_;
-  ObjectData* function_template_info_;
-  ZoneMap<int, ObjectData*> template_objects_;
-  ObjectData* scope_info_;
-};
-
-SharedFunctionInfoData::SharedFunctionInfoData(
-    JSHeapBroker* broker, ObjectData** storage,
-    Handle<SharedFunctionInfo> object)
-    : HeapObjectData(broker, storage, object),
-      builtin_id_(object->HasBuiltinId() ? object->builtin_id()
-                                         : Builtins::kNoBuiltinId),
-      context_header_size_(object->scope_info().ContextHeaderLength()),
-      GetBytecodeArray_(object->HasBytecodeArray()
-                            ? broker->GetOrCreateData(
-                                  object->GetBytecodeArray(broker->isolate()))
-                            : nullptr)
-#define INIT_MEMBER(type, name) , name##_(object->name())
-          BROKER_SFI_FIELDS(INIT_MEMBER)
-#undef INIT_MEMBER
-      ,
-      inlineability_(object->GetInlineability(broker->isolate())),
-      function_template_info_(nullptr),
-      template_objects_(broker->zone()),
-      scope_info_(nullptr) {
-  DCHECK_EQ(HasBuiltinId_, builtin_id_ != Builtins::kNoBuiltinId);
-  DCHECK_EQ(HasBytecodeArray_, GetBytecodeArray_ != nullptr);
-}
-
-void SharedFunctionInfoData::SerializeFunctionTemplateInfo(
-    JSHeapBroker* broker) {
-  if (function_template_info_) return;
-  function_template_info_ = broker->GetOrCreateData(
-      Handle<SharedFunctionInfo>::cast(object())->function_data(kAcquireLoad));
-}
-
-void SharedFunctionInfoData::SerializeScopeInfoChain(JSHeapBroker* broker) {
-  if (scope_info_) return;
-  scope_info_ = broker->GetOrCreateData(
-      Handle<SharedFunctionInfo>::cast(object())->scope_info());
-  if (!scope_info_->should_access_heap()) {
-    scope_info_->AsScopeInfo()->SerializeScopeInfoChain(broker);
-  }
-}
-
-class SourceTextModuleData : public HeapObjectData {
- public:
-  SourceTextModuleData(JSHeapBroker* broker, ObjectData** storage,
-                       Handle<SourceTextModule> object);
-  void Serialize(JSHeapBroker* broker);
-
-  ObjectData* GetCell(JSHeapBroker* broker, int cell_index) const;
-  ObjectData* GetImportMeta(JSHeapBroker* broker) const;
-
- private:
-  bool serialized_ = false;
-  ZoneVector<ObjectData*> imports_;
-  ZoneVector<ObjectData*> exports_;
-  ObjectData* import_meta_;
-};
-
-SourceTextModuleData::SourceTextModuleData(JSHeapBroker* broker,
-                                           ObjectData** storage,
-                                           Handle<SourceTextModule> object)
-    : HeapObjectData(broker, storage, object),
-      imports_(broker->zone()),
-      exports_(broker->zone()),
-      import_meta_(nullptr) {}
-
-ObjectData* SourceTextModuleData::GetCell(JSHeapBroker* broker,
-                                          int cell_index) const {
-  if (!serialized_) {
-    DCHECK(imports_.empty());
-    TRACE_BROKER_MISSING(broker,
-                         "module cell " << cell_index << " on " << this);
-    return nullptr;
-  }
-  ObjectData* cell;
-  switch (SourceTextModuleDescriptor::GetCellIndexKind(cell_index)) {
-    case SourceTextModuleDescriptor::kImport:
-      cell = imports_.at(SourceTextModule::ImportIndex(cell_index));
-      break;
-    case SourceTextModuleDescriptor::kExport:
-      cell = exports_.at(SourceTextModule::ExportIndex(cell_index));
-      break;
-    case SourceTextModuleDescriptor::kInvalid:
-      UNREACHABLE();
-  }
-  CHECK_NOT_NULL(cell);
-  return cell;
-}
-
-ObjectData* SourceTextModuleData::GetImportMeta(JSHeapBroker* broker) const {
-  CHECK(serialized_);
-  return import_meta_;
-}
-
-void SourceTextModuleData::Serialize(JSHeapBroker* broker) {
-  if (serialized_) return;
-  serialized_ = true;
-
-  TraceScope tracer(broker, this, "SourceTextModuleData::Serialize");
-  Handle<SourceTextModule> module = Handle<SourceTextModule>::cast(object());
-
-  // TODO(neis): We could be smarter and only serialize the cells we care about.
-  // TODO(neis): Define a helper for serializing a FixedArray into a ZoneVector.
-
-  DCHECK(imports_.empty());
-  Handle<FixedArray> imports(module->regular_imports(), broker->isolate());
-  int const imports_length = imports->length();
-  imports_.reserve(imports_length);
-  for (int i = 0; i < imports_length; ++i) {
-    imports_.push_back(broker->GetOrCreateData(imports->get(i)));
-  }
-  TRACE(broker, "Copied " << imports_.size() << " imports");
-
-  DCHECK(exports_.empty());
-  Handle<FixedArray> exports(module->regular_exports(), broker->isolate());
-  int const exports_length = exports->length();
-  exports_.reserve(exports_length);
-  for (int i = 0; i < exports_length; ++i) {
-    exports_.push_back(broker->GetOrCreateData(exports->get(i)));
-  }
-  TRACE(broker, "Copied " << exports_.size() << " exports");
-
-  DCHECK_NULL(import_meta_);
-  import_meta_ = broker->GetOrCreateData(module->import_meta());
-  TRACE(broker, "Copied import_meta");
-}
-
-class CellData : public HeapObjectData {
- public:
-  CellData(JSHeapBroker* broker, ObjectData** storage, Handle<Cell> object)
-      : HeapObjectData(broker, storage, object) {
-    DCHECK(!FLAG_turbo_direct_heap_access);
-  }
-};
-
-class JSGlobalObjectData : public JSObjectData {
- public:
-  JSGlobalObjectData(JSHeapBroker* broker, ObjectData** storage,
-                     Handle<JSGlobalObject> object);
-  bool IsDetached() const { return is_detached_; }
-
-  ObjectData* GetPropertyCell(
-      JSHeapBroker* broker, ObjectData* name,
-      SerializationPolicy policy = SerializationPolicy::kAssumeSerialized);
-
- private:
-  bool const is_detached_;
-
-  // Properties that either
-  // (1) are known to exist as property cells on the global object, or
-  // (2) are known not to (possibly they don't exist at all).
-  // In case (2), the second pair component is nullptr.
-  ZoneVector<std::pair<ObjectData*, ObjectData*>> properties_;
-};
-
-JSGlobalObjectData::JSGlobalObjectData(JSHeapBroker* broker,
-                                       ObjectData** storage,
-                                       Handle<JSGlobalObject> object)
-    : JSObjectData(broker, storage, object),
-      is_detached_(object->IsDetached()),
-      properties_(broker->zone()) {}
-
-class JSGlobalProxyData : public JSObjectData {
- public:
-  JSGlobalProxyData(JSHeapBroker* broker, ObjectData** storage,
-                    Handle<JSGlobalProxy> object);
-};
-
-JSGlobalProxyData::JSGlobalProxyData(JSHeapBroker* broker, ObjectData** storage,
-                                     Handle<JSGlobalProxy> object)
-    : JSObjectData(broker, storage, object) {}
-
-namespace {
-base::Optional<PropertyCellRef> GetPropertyCellFromHeap(JSHeapBroker* broker,
-                                                        Handle<Name> name) {
-  LookupIterator it(
-      broker->isolate(),
-      handle(broker->target_native_context().object()->global_object(),
-             broker->isolate()),
-      name, LookupIterator::OWN);
-  it.TryLookupCachedProperty();
-  if (it.state() == LookupIterator::DATA &&
-      it.GetHolder<JSObject>()->IsJSGlobalObject()) {
-    return PropertyCellRef(broker, it.GetPropertyCell());
-  }
-  return base::nullopt;
-}
-}  // namespace
-
-ObjectData* JSGlobalObjectData::GetPropertyCell(JSHeapBroker* broker,
-                                                ObjectData* name,
-                                                SerializationPolicy policy) {
-  CHECK_NOT_NULL(name);
-  for (auto const& p : properties_) {
-    if (p.first == name) return p.second;
-  }
-
-  if (policy == SerializationPolicy::kAssumeSerialized) {
-    TRACE_MISSING(broker, "knowledge about global property " << name);
-    return nullptr;
-  }
-
-  ObjectData* result = nullptr;
-  base::Optional<PropertyCellRef> cell =
-      GetPropertyCellFromHeap(broker, Handle<Name>::cast(name->object()));
-  if (cell.has_value()) {
-    result = cell->data();
-    if (!result->should_access_heap()) {
-      result->AsPropertyCell()->Serialize(broker);
-    }
-  }
-  properties_.push_back({name, result});
-  return result;
-}
-
-class TemplateObjectDescriptionData : public HeapObjectData {
- public:
-  TemplateObjectDescriptionData(JSHeapBroker* broker, ObjectData** storage,
-                                Handle<TemplateObjectDescription> object)
-      : HeapObjectData(broker, storage, object) {
-    DCHECK(!FLAG_turbo_direct_heap_access);
-  }
-};
-
-class CodeData : public HeapObjectData {
- public:
-  CodeData(JSHeapBroker* broker, ObjectData** storage, Handle<Code> object)
-      : HeapObjectData(broker, storage, object),
-        inlined_bytecode_size_(object->inlined_bytecode_size() > 0 &&
-                                       !object->marked_for_deoptimization()
-                                   ? object->inlined_bytecode_size()
-                                   : 0) {
-    DCHECK(!FLAG_turbo_direct_heap_access);
-  }
-
-  unsigned inlined_bytecode_size() const { return inlined_bytecode_size_; }
-
- private:
-  unsigned const inlined_bytecode_size_;
-};
-
-#define DEFINE_IS(Name)                                                 \
-  bool ObjectData::Is##Name() const {                                   \
-    if (should_access_heap()) {                                         \
-      return object()->Is##Name();                                      \
-    }                                                                   \
-    if (is_smi()) return false;                                         \
-    InstanceType instance_type =                                        \
-        static_cast<const HeapObjectData*>(this)->GetMapInstanceType(); \
-    return InstanceTypeChecker::Is##Name(instance_type);                \
-  }
-HEAP_BROKER_SERIALIZED_OBJECT_LIST(DEFINE_IS)
-HEAP_BROKER_POSSIBLY_BACKGROUND_SERIALIZED_OBJECT_LIST(DEFINE_IS)
-HEAP_BROKER_BACKGROUND_SERIALIZED_OBJECT_LIST(DEFINE_IS)
-HEAP_BROKER_NEVER_SERIALIZED_OBJECT_LIST(DEFINE_IS)
-#undef DEFINE_IS
-
-#define DEFINE_AS(Name)                                       \
-  Name##Data* ObjectData::As##Name() {                        \
-    CHECK(Is##Name());                                        \
-    CHECK(kind_ == kSerializedHeapObject ||                   \
-          kind_ == kBackgroundSerializedHeapObject);          \
-    return static_cast<Name##Data*>(this);                    \
-  }
-HEAP_BROKER_SERIALIZED_OBJECT_LIST(DEFINE_AS)
-HEAP_BROKER_POSSIBLY_BACKGROUND_SERIALIZED_OBJECT_LIST(DEFINE_AS)
-HEAP_BROKER_BACKGROUND_SERIALIZED_OBJECT_LIST(DEFINE_AS)
-#undef DEFINE_AS
-
-// TODO(solanes, v8:10866): Remove once FLAG_turbo_direct_heap_access is
-// removed.
-// This macro defines the Asxxx methods for NeverSerialized objects, which
-// should only be used with direct heap access off.
-#define DEFINE_AS(Name)                     \
-  Name##Data* ObjectData::As##Name() {      \
-    DCHECK(!FLAG_turbo_direct_heap_access); \
-    CHECK(Is##Name());                      \
-    CHECK_EQ(kind_, kSerializedHeapObject); \
-    return static_cast<Name##Data*>(this);  \
-  }
-HEAP_BROKER_NEVER_SERIALIZED_OBJECT_LIST(DEFINE_AS)
-#undef DEFINE_AS
-
-ObjectData* JSObjectData::GetInobjectField(int property_index) const {
-  CHECK_LT(static_cast<size_t>(property_index), inobject_fields_.size());
-  return inobject_fields_[property_index];
-}
-
-bool JSObjectData::cow_or_empty_elements_tenured() const {
-  return cow_or_empty_elements_tenured_;
-}
-
-ObjectData* JSObjectData::elements() const {
-  CHECK(serialized_elements_);
-  return elements_;
-}
-
-void JSObjectData::SerializeAsBoilerplate(JSHeapBroker* broker) {
-  SerializeRecursiveAsBoilerplate(broker, kMaxFastLiteralDepth);
-}
-
-void JSObjectData::SerializeElements(JSHeapBroker* broker) {
-  if (serialized_elements_) return;
-  serialized_elements_ = true;
-
-  TraceScope tracer(broker, this, "JSObjectData::SerializeElements");
-  Handle<JSObject> boilerplate = Handle<JSObject>::cast(object());
-  Handle<FixedArrayBase> elements_object(boilerplate->elements(),
-                                         broker->isolate());
-  DCHECK_NULL(elements_);
-  elements_ = broker->GetOrCreateData(elements_object);
-  DCHECK(elements_->IsFixedArrayBase());
-}
-
-void MapData::SerializeConstructor(JSHeapBroker* broker) {
-  if (serialized_constructor_) return;
-  serialized_constructor_ = true;
-
-  TraceScope tracer(broker, this, "MapData::SerializeConstructor");
-  Handle<Map> map = Handle<Map>::cast(object());
-  DCHECK(!map->IsContextMap());
-  DCHECK_NULL(constructor_);
-  constructor_ = broker->GetOrCreateData(map->GetConstructor());
-}
-
-void MapData::SerializeBackPointer(JSHeapBroker* broker) {
-  if (serialized_backpointer_) return;
-  serialized_backpointer_ = true;
-
-  TraceScope tracer(broker, this, "MapData::SerializeBackPointer");
-  Handle<Map> map = Handle<Map>::cast(object());
-  DCHECK_NULL(backpointer_);
-  DCHECK(!map->IsContextMap());
-  backpointer_ = broker->GetOrCreateData(map->GetBackPointer());
-}
-
-void MapData::SerializePrototype(JSHeapBroker* broker) {
-  if (serialized_prototype_) return;
-  serialized_prototype_ = true;
-
-  TraceScope tracer(broker, this, "MapData::SerializePrototype");
-  Handle<Map> map = Handle<Map>::cast(object());
-  DCHECK_NULL(prototype_);
-  prototype_ = broker->GetOrCreateData(map->prototype());
-}
-
-void MapData::SerializeOwnDescriptors(JSHeapBroker* broker) {
-  if (serialized_own_descriptors_) return;
-  serialized_own_descriptors_ = true;
-
-  TraceScope tracer(broker, this, "MapData::SerializeOwnDescriptors");
-  Handle<Map> map = Handle<Map>::cast(object());
-
-  for (InternalIndex i : map->IterateOwnDescriptors()) {
-    SerializeOwnDescriptor(broker, i);
-  }
-}
-
-void MapData::SerializeOwnDescriptor(JSHeapBroker* broker,
-                                     InternalIndex descriptor_index) {
-  TraceScope tracer(broker, this, "MapData::SerializeOwnDescriptor");
-  Handle<Map> map = Handle<Map>::cast(object());
-  Isolate* isolate = broker->isolate();
-
-  if (instance_descriptors_ == nullptr) {
-    instance_descriptors_ =
-        broker->GetOrCreateData(map->instance_descriptors(isolate));
-  }
-
-  if (instance_descriptors()->should_access_heap()) {
-    // When accessing the fields concurrently, we still have to recurse on the
-    // owner map if it is different than the current map. This is because
-    // {instance_descriptors_} gets set on SerializeOwnDescriptor and otherwise
-    // we risk the field owner having a null {instance_descriptors_}.
-    Handle<DescriptorArray> descriptors(map->instance_descriptors(isolate),
-                                        isolate);
-    if (descriptors->GetDetails(descriptor_index).location() == kField) {
-      Handle<Map> owner(map->FindFieldOwner(isolate, descriptor_index),
-                        isolate);
-      if (!owner.equals(map)) {
-        broker->GetOrCreateData(owner)->AsMap()->SerializeOwnDescriptor(
-            broker, descriptor_index);
-      }
-    }
-  } else {
-    DescriptorArrayData* descriptors =
-        instance_descriptors()->AsDescriptorArray();
-    descriptors->SerializeDescriptor(broker, map, descriptor_index);
-  }
-}
-
-void MapData::SerializeRootMap(JSHeapBroker* broker) {
-  if (serialized_root_map_) return;
-  serialized_root_map_ = true;
-
-  TraceScope tracer(broker, this, "MapData::SerializeRootMap");
-  Handle<Map> map = Handle<Map>::cast(object());
-  DCHECK_NULL(root_map_);
-  root_map_ = broker->GetOrCreateData(map->FindRootMap(broker->isolate()));
-}
-
-ObjectData* MapData::FindRootMap() const { return root_map_; }
-
-void JSObjectData::SerializeRecursiveAsBoilerplate(JSHeapBroker* broker,
-                                                   int depth) {
-  if (serialized_as_boilerplate_) return;
-  serialized_as_boilerplate_ = true;
-
-  TraceScope tracer(broker, this,
-                    "JSObjectData::SerializeRecursiveAsBoilerplate");
-  Handle<JSObject> boilerplate = Handle<JSObject>::cast(object());
-
-  // We only serialize boilerplates that pass the IsInlinableFastLiteral
-  // check, so we only do a check on the depth here.
-  CHECK_GT(depth, 0);
-  CHECK(!boilerplate->map().is_deprecated());
-
-  // Serialize the elements.
-  Isolate* const isolate = broker->isolate();
-  Handle<FixedArrayBase> elements_object(boilerplate->elements(), isolate);
-
-  // Boilerplates need special serialization - we need to make sure COW arrays
-  // are tenured. Boilerplate objects should only be reachable from their
-  // allocation site, so it is safe to assume that the elements have not been
-  // serialized yet.
-
-  bool const empty_or_cow =
-      elements_object->length() == 0 ||
-      elements_object->map() == ReadOnlyRoots(isolate).fixed_cow_array_map();
-  if (empty_or_cow) {
-    // We need to make sure copy-on-write elements are tenured.
-    if (ObjectInYoungGeneration(*elements_object)) {
-      elements_object = isolate->factory()->CopyAndTenureFixedCOWArray(
-          Handle<FixedArray>::cast(elements_object));
-      boilerplate->set_elements(*elements_object);
-    }
-    cow_or_empty_elements_tenured_ = true;
-  }
-
-  DCHECK_NULL(elements_);
-  DCHECK(!serialized_elements_);
-  serialized_elements_ = true;
-  elements_ = broker->GetOrCreateData(elements_object);
-  DCHECK(elements_->IsFixedArrayBase());
-
-  if (empty_or_cow || elements_->should_access_heap()) {
-    // No need to do anything here. Empty or copy-on-write elements
-    // do not need to be serialized because we only need to store the elements
-    // reference to the allocated object.
-  } else if (boilerplate->HasSmiOrObjectElements()) {
-    elements_->AsFixedArray()->SerializeContents(broker);
-    Handle<FixedArray> fast_elements =
-        Handle<FixedArray>::cast(elements_object);
-    int length = elements_object->length();
-    for (int i = 0; i < length; i++) {
-      Handle<Object> value(fast_elements->get(i), isolate);
-      if (value->IsJSObject()) {
-        ObjectData* value_data = broker->GetOrCreateData(value);
-        if (!value_data->should_access_heap()) {
-          value_data->AsJSObject()->SerializeRecursiveAsBoilerplate(broker,
-                                                                    depth - 1);
-        }
-      }
-    }
-  } else {
-    CHECK(boilerplate->HasDoubleElements());
-    CHECK_LE(elements_object->Size(), kMaxRegularHeapObjectSize);
-    DCHECK_EQ(elements_->kind(), ObjectDataKind::kSerializedHeapObject);
-    elements_->AsFixedDoubleArray()->SerializeContents(broker);
-  }
-
-  // TODO(turbofan): Do we want to support out-of-object properties?
-  CHECK(boilerplate->HasFastProperties() &&
-        boilerplate->property_array().length() == 0);
-  CHECK_EQ(inobject_fields_.size(), 0u);
-
-  // Check the in-object properties.
-  Handle<DescriptorArray> descriptors(
-      boilerplate->map().instance_descriptors(isolate), isolate);
-  for (InternalIndex i : boilerplate->map().IterateOwnDescriptors()) {
-    PropertyDetails details = descriptors->GetDetails(i);
-    if (details.location() != kField) continue;
-    DCHECK_EQ(kData, details.kind());
-
-    FieldIndex field_index = FieldIndex::ForDescriptor(boilerplate->map(), i);
-    // Make sure {field_index} agrees with {inobject_properties} on the index of
-    // this field.
-    DCHECK_EQ(field_index.property_index(),
-              static_cast<int>(inobject_fields_.size()));
-    Handle<Object> value(boilerplate->RawFastPropertyAt(field_index), isolate);
-    // In case of double fields we use a sentinel NaN value to mark
-    // uninitialized fields. A boilerplate value with such a field may migrate
-    // from its double to a tagged representation. The sentinel value carries
-    // no special meaning when it occurs in a heap number, so we would like to
-    // recover the uninitialized value. We check for the sentinel here,
-    // specifically, since migrations might have been triggered as part of
-    // boilerplate serialization.
-    if (!details.representation().IsDouble() && value->IsHeapNumber() &&
-        HeapNumber::cast(*value).value_as_bits() == kHoleNanInt64) {
-      value = isolate->factory()->uninitialized_value();
-    }
-    ObjectData* value_data = broker->GetOrCreateData(value);
-    if (value_data->IsJSObject() && !value_data->should_access_heap()) {
-      value_data->AsJSObject()->SerializeRecursiveAsBoilerplate(broker,
-                                                                depth - 1);
-    }
-    inobject_fields_.push_back(value_data);
-  }
-  TRACE(broker, "Copied " << inobject_fields_.size() << " in-object fields");
-
-  if (!map()->should_access_heap()) {
-    map()->AsMap()->SerializeOwnDescriptors(broker);
-  }
-
-  if (IsJSArray() && !FLAG_turbo_direct_heap_access) {
-    AsJSArray()->Serialize(broker);
-  }
-}
-
-void RegExpBoilerplateDescriptionData::Serialize(JSHeapBroker* broker) {
-  if (serialized_) return;  // Only serialize once.
-  serialized_ = true;
-
-  TraceScope tracer(broker, this,
-                    "RegExpBoilerplateDescriptionData::Serialize");
-  auto boilerplate = Handle<RegExpBoilerplateDescription>::cast(object());
-
-  data_ = broker->GetOrCreateData(boilerplate->data());
-  source_ = broker->GetOrCreateData(boilerplate->source());
-  flags_ = boilerplate->flags();
-}
-
-#ifdef DEBUG
-bool ObjectRef::IsNeverSerializedHeapObject() const {
-  return data_->kind() == ObjectDataKind::kNeverSerializedHeapObject;
-}
-#endif  // DEBUG
-
-bool ObjectRef::equals(const ObjectRef& other) const {
-#ifdef DEBUG
-  if (broker()->mode() == JSHeapBroker::kSerialized &&
-      data_->used_status == ObjectData::Usage::kUnused) {
-    data_->used_status = ObjectData::Usage::kOnlyIdentityUsed;
-  }
-#endif  // DEBUG
-  return data_ == other.data_;
-}
-
-bool ObjectRef::ShouldHaveBeenSerialized() const {
-  return broker()->mode() == JSHeapBroker::kSerialized &&
-         data()->kind() == kSerializedHeapObject;
-}
-
-Isolate* ObjectRef::isolate() const { return broker()->isolate(); }
-
-ContextRef ContextRef::previous(size_t* depth,
-                                SerializationPolicy policy) const {
-  DCHECK_NOT_NULL(depth);
-
-  if (data_->should_access_heap()) {
-    Context current = *object();
-    while (*depth != 0 && current.unchecked_previous().IsContext()) {
-      current = Context::cast(current.unchecked_previous());
-      (*depth)--;
-    }
-    return ContextRef(broker(), broker()->CanonicalPersistentHandle(current));
-  }
-
-  if (*depth == 0) return *this;
-
-  ObjectData* previous_data = data()->AsContext()->previous(broker(), policy);
-  if (previous_data == nullptr || !previous_data->IsContext()) return *this;
-
-  *depth = *depth - 1;
-  return ContextRef(broker(), previous_data).previous(depth, policy);
-}
-
-base::Optional<ObjectRef> ContextRef::get(int index,
-                                          SerializationPolicy policy) const {
-  if (data_->should_access_heap()) {
-    Handle<Object> value(object()->get(index), broker()->isolate());
-    return ObjectRef(broker(), value);
-  }
-  ObjectData* optional_slot =
-      data()->AsContext()->GetSlot(broker(), index, policy);
-  if (optional_slot != nullptr) {
-    return ObjectRef(broker(), optional_slot);
-  }
-  return base::nullopt;
-}
-
-SourceTextModuleRef ContextRef::GetModule(SerializationPolicy policy) const {
-  ContextRef current = *this;
-  while (current.map().instance_type() != MODULE_CONTEXT_TYPE) {
-    size_t depth = 1;
-    current = current.previous(&depth, policy);
-    CHECK_EQ(depth, 0);
-  }
-  return current.get(Context::EXTENSION_INDEX, policy)
-      .value()
-      .AsSourceTextModule();
-}
-
 JSHeapBroker::JSHeapBroker(Isolate* isolate, Zone* broker_zone,
                            bool tracing_enabled, bool is_concurrent_inlining,
                            CodeKind code_kind)
@@ -2560,7 +58,6 @@ JSHeapBroker::JSHeapBroker(Isolate* isolate, Zone* broker_zone,
   // immediately with a larger-capacity one.  It doesn't seem to affect the
   // performance in a noticeable way though.
   TRACE(this, "Constructing heap broker");
-  DCHECK_IMPLIES(is_concurrent_inlining_, FLAG_turbo_direct_heap_access);
 }
 
 JSHeapBroker::~JSHeapBroker() { DCHECK_NULL(local_isolate_); }
@@ -2602,7 +99,7 @@ void JSHeapBroker::AttachLocalIsolate(OptimizedCompilationInfo* info,
   local_isolate_->heap()->AttachPersistentHandles(
       info->DetachPersistentHandles());
 
-  if (FLAG_turbo_direct_heap_access) {
+  if (is_concurrent_inlining()) {
     // Ensure any serialization that happens on the background has been
     // performed.
     target_native_context().SerializeOnBackground();
@@ -2625,88 +122,6 @@ void JSHeapBroker::StopSerializing() {
   mode_ = kSerialized;
 }
 
-#ifdef DEBUG
-void JSHeapBroker::PrintRefsAnalysis() const {
-  // Usage counts
-  size_t used_total = 0, unused_total = 0, identity_used_total = 0;
-  for (RefsMap::Entry* ref = refs_->Start(); ref != nullptr;
-       ref = refs_->Next(ref)) {
-    switch (ref->value->used_status) {
-      case ObjectData::Usage::kUnused:
-        ++unused_total;
-        break;
-      case ObjectData::Usage::kOnlyIdentityUsed:
-        ++identity_used_total;
-        break;
-      case ObjectData::Usage::kDataUsed:
-        ++used_total;
-        break;
-    }
-  }
-
-  // Ref types analysis
-  TRACE_BROKER_MEMORY(
-      this, "Refs: " << refs_->occupancy() << "; data used: " << used_total
-                     << "; only identity used: " << identity_used_total
-                     << "; unused: " << unused_total);
-  size_t used_smis = 0, unused_smis = 0, identity_used_smis = 0;
-  size_t used[LAST_TYPE + 1] = {0};
-  size_t unused[LAST_TYPE + 1] = {0};
-  size_t identity_used[LAST_TYPE + 1] = {0};
-  for (RefsMap::Entry* ref = refs_->Start(); ref != nullptr;
-       ref = refs_->Next(ref)) {
-    if (ref->value->is_smi()) {
-      switch (ref->value->used_status) {
-        case ObjectData::Usage::kUnused:
-          ++unused_smis;
-          break;
-        case ObjectData::Usage::kOnlyIdentityUsed:
-          ++identity_used_smis;
-          break;
-        case ObjectData::Usage::kDataUsed:
-          ++used_smis;
-          break;
-      }
-    } else {
-      InstanceType instance_type;
-      if (ref->value->should_access_heap()) {
-        instance_type = Handle<HeapObject>::cast(ref->value->object())
-                            ->map()
-                            .instance_type();
-      } else {
-        instance_type = ref->value->AsHeapObject()->GetMapInstanceType();
-      }
-      CHECK_LE(FIRST_TYPE, instance_type);
-      CHECK_LE(instance_type, LAST_TYPE);
-      switch (ref->value->used_status) {
-        case ObjectData::Usage::kUnused:
-          ++unused[instance_type];
-          break;
-        case ObjectData::Usage::kOnlyIdentityUsed:
-          ++identity_used[instance_type];
-          break;
-        case ObjectData::Usage::kDataUsed:
-          ++used[instance_type];
-          break;
-      }
-    }
-  }
-
-  TRACE_BROKER_MEMORY(
-      this, "Smis: " << used_smis + identity_used_smis + unused_smis
-                     << "; data used: " << used_smis << "; only identity used: "
-                     << identity_used_smis << "; unused: " << unused_smis);
-  for (uint16_t i = FIRST_TYPE; i <= LAST_TYPE; ++i) {
-    size_t total = used[i] + identity_used[i] + unused[i];
-    if (total == 0) continue;
-    TRACE_BROKER_MEMORY(
-        this, InstanceType(i) << ": " << total << "; data used: " << used[i]
-                              << "; only identity used: " << identity_used[i]
-                              << "; unused: " << unused[i]);
-  }
-}
-#endif  // DEBUG
-
 void JSHeapBroker::Retire() {
   CHECK_EQ(mode_, kSerialized);
   TRACE(this, "Retiring");
@@ -2719,16 +134,11 @@ void JSHeapBroker::Retire() {
 
 void JSHeapBroker::SetTargetNativeContextRef(
     Handle<NativeContext> native_context) {
-  // The MapData constructor uses {target_native_context_}. This creates a
-  // benign cycle that we break by setting {target_native_context_} right before
-  // starting to serialize (thus creating dummy data), and then again properly
-  // right after.
   DCHECK((mode() == kDisabled && !target_native_context_.has_value()) ||
          (mode() == kSerializing &&
-          target_native_context_->object().equals(native_context) &&
-          target_native_context_->data_->kind() == kUnserializedHeapObject));
-  target_native_context_ =
-      NativeContextRef(this, CanonicalPersistentHandle(*native_context));
+          target_native_context_->object().is_identical_to(native_context) &&
+          target_native_context_->is_unserialized_heap_object()));
+  target_native_context_ = MakeRef(this, *native_context);
 }
 
 void JSHeapBroker::CollectArrayAndObjectPrototypes() {
@@ -2755,7 +165,7 @@ StringRef JSHeapBroker::GetTypedArrayStringTag(ElementsKind kind) {
   switch (kind) {
 #define TYPED_ARRAY_STRING_TAG(Type, type, TYPE, ctype) \
   case ElementsKind::TYPE##_ELEMENTS:                   \
-    return StringRef(this, isolate()->factory()->Type##Array_string());
+    return MakeRef(this, isolate()->factory()->Type##Array_string());
     TYPED_ARRAYS(TYPED_ARRAY_STRING_TAG)
 #undef TYPED_ARRAY_STRING_TAG
     default:
@@ -2798,201 +208,38 @@ bool JSHeapBroker::IsSerializedForCompilation(
 }
 
 bool JSHeapBroker::IsArrayOrObjectPrototype(const JSObjectRef& object) const {
+  return IsArrayOrObjectPrototype(object.object());
+}
+
+bool JSHeapBroker::IsArrayOrObjectPrototype(Handle<JSObject> object) const {
   if (mode() == kDisabled) {
-    return isolate()->IsInAnyContext(*object.object(),
+    return isolate()->IsInAnyContext(*object,
                                      Context::INITIAL_ARRAY_PROTOTYPE_INDEX) ||
-           isolate()->IsInAnyContext(*object.object(),
+           isolate()->IsInAnyContext(*object,
                                      Context::INITIAL_OBJECT_PROTOTYPE_INDEX);
   }
   CHECK(!array_and_object_prototypes_.empty());
-  return array_and_object_prototypes_.find(object.object()) !=
+  return array_and_object_prototypes_.find(object) !=
          array_and_object_prototypes_.end();
 }
 
-void JSHeapBroker::InitializeAndStartSerializing(
-    Handle<NativeContext> native_context) {
-  TraceScope tracer(this, "JSHeapBroker::InitializeAndStartSerializing");
-
-  CHECK_EQ(mode_, kDisabled);
-  mode_ = kSerializing;
-
-  // Throw away the dummy data that we created while disabled.
-  refs_->Clear();
-  refs_ =
-      zone()->New<RefsMap>(kInitialRefsBucketCount, AddressMatcher(), zone());
-
-  SetTargetNativeContextRef(native_context);
-  target_native_context().Serialize();
-  if (!FLAG_turbo_direct_heap_access) {
-    // Perform full native context serialization now if we can't do it later on
-    // the background thread.
-    target_native_context().SerializeOnBackground();
-  }
-
-  CollectArrayAndObjectPrototypes();
-
-  Factory* const f = isolate()->factory();
-  if (!FLAG_turbo_direct_heap_access) {
-    ObjectData* data;
-    data = GetOrCreateData(f->array_buffer_detaching_protector());
-    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
-    data = GetOrCreateData(f->array_constructor_protector());
-    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
-    data = GetOrCreateData(f->array_iterator_protector());
-    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
-    data = GetOrCreateData(f->array_species_protector());
-    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
-    data = GetOrCreateData(f->no_elements_protector());
-    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
-    data = GetOrCreateData(f->promise_hook_protector());
-    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
-    data = GetOrCreateData(f->promise_species_protector());
-    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
-    data = GetOrCreateData(f->promise_then_protector());
-    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
-    data = GetOrCreateData(f->string_length_protector());
-    if (!data->should_access_heap()) data->AsPropertyCell()->Serialize(this);
-  }
-  GetOrCreateData(f->many_closures_cell());
-  GetOrCreateData(
-      CodeFactory::CEntry(isolate(), 1, kDontSaveFPRegs, kArgvOnStack, true));
-
-  TRACE(this, "Finished serializing standard objects");
+ObjectData* JSHeapBroker::TryGetOrCreateData(Object object,
+                                             GetOrCreateDataFlags flags) {
+  return TryGetOrCreateData(CanonicalPersistentHandle(object), flags);
 }
 
 ObjectData* JSHeapBroker::GetOrCreateData(Handle<Object> object,
-    ObjectRef::BackgroundSerialization background_serialization) {
-  ObjectData* return_value =
-      TryGetOrCreateData(object, true, background_serialization);
+                                          GetOrCreateDataFlags flags) {
+  ObjectData* return_value = TryGetOrCreateData(object, flags | kCrashOnError);
   DCHECK_NOT_NULL(return_value);
   return return_value;
 }
 
-// clang-format off
-ObjectData* JSHeapBroker::TryGetOrCreateData(Handle<Object> object,
-    bool crash_on_error,
-    ObjectRef::BackgroundSerialization background_serialization) {
-  RefsMap::Entry* entry = refs_->Lookup(object.address());
-  if (entry != nullptr) return entry->value;
-
-  if (mode() == JSHeapBroker::kDisabled) {
-    entry = refs_->LookupOrInsert(object.address());
-    ObjectData** storage = &(entry->value);
-    if (*storage == nullptr) {
-      entry->value = zone()->New<ObjectData>(
-          this, storage, object,
-          object->IsSmi() ? kSmi : kUnserializedHeapObject);
-    }
-    return *storage;
-  }
-
-  CHECK(mode() == JSHeapBroker::kSerializing ||
-        mode() == JSHeapBroker::kSerialized);
-
-  ObjectData* object_data;
-  if (object->IsSmi()) {
-    entry = refs_->LookupOrInsert(object.address());
-    object_data = zone()->New<ObjectData>(this, &(entry->value), object, kSmi);
-  } else if (IsReadOnlyHeapObject(*object)) {
-    entry = refs_->LookupOrInsert(object.address());
-    object_data = zone()->New<ObjectData>(this, &(entry->value), object,
-                                          kUnserializedReadOnlyHeapObject);
-// TODO(solanes, v8:10866): Remove the if/else in this macro once we remove the
-// FLAG_turbo_direct_heap_access.
-#define CREATE_DATA_FOR_DIRECT_READ(name)                                 \
-  } else if (object->Is##name()) {                                        \
-    if (FLAG_turbo_direct_heap_access) {                                  \
-      entry = refs_->LookupOrInsert(object.address());                    \
-      object_data = zone()->New<ObjectData>(                              \
-        this, &(entry->value), object, kNeverSerializedHeapObject);       \
-    } else if (mode() == kSerializing) {                                  \
-      entry = refs_->LookupOrInsert(object.address());                    \
-      object_data = zone()->New<name##Data>(this, &(entry->value),        \
-                                            Handle<name>::cast(object));  \
-    } else {                                                              \
-      CHECK(!crash_on_error);                                             \
-      return nullptr;                                                     \
-    }
-  HEAP_BROKER_NEVER_SERIALIZED_OBJECT_LIST(CREATE_DATA_FOR_DIRECT_READ)
-#undef CREATE_DATA_FOR_DIRECT_READ
-#define CREATE_DATA_FOR_POSSIBLE_SERIALIZATION(name)                      \
-    } else if (object->Is##name()) {                                      \
-      if (mode() == kSerialized &&                                        \
-          background_serialization !=                                     \
-            ObjectRef::BackgroundSerialization::kAllowed) {               \
-        CHECK(!crash_on_error);                                           \
-        return nullptr;                                                   \
-      }                                                                   \
-      entry = refs_->LookupOrInsert(object.address());                    \
-      ObjectDataKind kind = (background_serialization ==                      \
-                         ObjectRef::BackgroundSerialization::kAllowed)    \
-                        ? kBackgroundSerializedHeapObject                 \
-                        : kSerializedHeapObject;                          \
-      object_data = zone()->New<name##Data>(this, &(entry->value),        \
-                                            Handle<name>::cast(object),   \
-                                            kind);
-  HEAP_BROKER_POSSIBLY_BACKGROUND_SERIALIZED_OBJECT_LIST(
-      CREATE_DATA_FOR_POSSIBLE_SERIALIZATION)
-#undef CREATE_DATA_FOR_POSSIBLE_SERIALIZATION
-#define CREATE_DATA_FOR_BACKGROUND_SERIALIZATION(name)                    \
-  } else if (object->Is##name()) {                                        \
-    if (FLAG_turbo_direct_heap_access) {                                  \
-      entry = refs_->LookupOrInsert(object.address());                    \
-      object_data = zone()->New<name##Data>(                              \
-          this, &(entry->value), Handle<name>::cast(object),              \
-          kBackgroundSerializedHeapObject);                               \
-    } else if (mode() == kSerializing) {                                  \
-      entry = refs_->LookupOrInsert(object.address());                    \
-      object_data = zone()->New<name##Data>(this, &(entry->value),        \
-                                            Handle<name>::cast(object));  \
-    } else {                                                              \
-      CHECK(!crash_on_error);                                             \
-      return nullptr;                                                     \
-    }
-  HEAP_BROKER_BACKGROUND_SERIALIZED_OBJECT_LIST(
-      CREATE_DATA_FOR_BACKGROUND_SERIALIZATION)
-#undef CREATE_DATA_FOR_SERIALIZATION
-#define CREATE_DATA_FOR_SERIALIZATION(name)                               \
-  } else if (object->Is##name()) {                                        \
-    if (mode() == kSerializing) {                                         \
-      entry = refs_->LookupOrInsert(object.address());                    \
-      object_data = zone()->New<name##Data>(this, &(entry->value),        \
-                                            Handle<name>::cast(object));  \
-    } else {                                                              \
-      CHECK(!crash_on_error);                                             \
-      return nullptr;                                                     \
-    }
-  HEAP_BROKER_SERIALIZED_OBJECT_LIST(CREATE_DATA_FOR_SERIALIZATION)
-#undef CREATE_DATA_FOR_SERIALIZATION
-  } else {
-    UNREACHABLE();
-  }
-  // At this point the entry pointer is not guaranteed to be valid as
-  // the refs_ hash hable could be resized by one of the constructors above.
-  DCHECK_EQ(object_data, refs_->Lookup(object.address())->value);
-  return object_data;
-}
-// clang-format on
-
-ObjectData* JSHeapBroker::GetOrCreateData(
-    Object object,
-    ObjectRef::BackgroundSerialization background_serialization) {
-  return GetOrCreateData(CanonicalPersistentHandle(object),
-                         background_serialization);
+ObjectData* JSHeapBroker::GetOrCreateData(Object object,
+                                          GetOrCreateDataFlags flags) {
+  return GetOrCreateData(CanonicalPersistentHandle(object), flags);
 }
 
-#define DEFINE_IS_AND_AS(Name)                                    \
-  bool ObjectRef::Is##Name() const { return data()->Is##Name(); } \
-  Name##Ref ObjectRef::As##Name() const {                         \
-    DCHECK(Is##Name());                                           \
-    return Name##Ref(broker(), data());                           \
-  }
-HEAP_BROKER_SERIALIZED_OBJECT_LIST(DEFINE_IS_AND_AS)
-HEAP_BROKER_POSSIBLY_BACKGROUND_SERIALIZED_OBJECT_LIST(DEFINE_IS_AND_AS)
-HEAP_BROKER_BACKGROUND_SERIALIZED_OBJECT_LIST(DEFINE_IS_AND_AS)
-HEAP_BROKER_NEVER_SERIALIZED_OBJECT_LIST(DEFINE_IS_AND_AS)
-#undef DEFINE_IS_AND_AS
-
 bool JSHeapBroker::StackHasOverflowed() const {
   DCHECK_IMPLIES(local_isolate_ == nullptr,
                  ThreadId::Current() == isolate_->thread_id());
@@ -3002,1742 +249,12 @@ bool JSHeapBroker::StackHasOverflowed() const {
 }
 
 bool JSHeapBroker::ObjectMayBeUninitialized(Handle<Object> object) const {
-  return !IsMainThread() && object->IsHeapObject() &&
-         isolate()->heap()->IsPendingAllocation(HeapObject::cast(*object));
-}
-
-bool ObjectRef::IsSmi() const { return data()->is_smi(); }
-
-int ObjectRef::AsSmi() const {
-  DCHECK(IsSmi());
-  // Handle-dereference is always allowed for Handle<Smi>.
-  return Handle<Smi>::cast(object())->value();
-}
-
-base::Optional<MapRef> JSObjectRef::GetObjectCreateMap() const {
-  if (data_->should_access_heap()) {
-    Handle<Map> instance_map;
-    if (Map::TryGetObjectCreateMap(broker()->isolate(), object())
-            .ToHandle(&instance_map)) {
-      return MapRef(broker(), instance_map);
-    } else {
-      return base::Optional<MapRef>();
-    }
-  }
-  ObjectData* map_data = data()->AsJSObject()->object_create_map(broker());
-  if (map_data == nullptr) return base::Optional<MapRef>();
-  if (map_data->should_access_heap()) {
-    return MapRef(broker(), map_data->object());
-  }
-  return MapRef(broker(), map_data->AsMap());
-}
-
-#define DEF_TESTER(Type, ...)                              \
-  bool MapRef::Is##Type##Map() const {                     \
-    return InstanceTypeChecker::Is##Type(instance_type()); \
-  }
-INSTANCE_TYPE_CHECKERS(DEF_TESTER)
-#undef DEF_TESTER
-
-base::Optional<MapRef> MapRef::AsElementsKind(ElementsKind kind) const {
-  if (data_->should_access_heap()) {
-    return MapRef(broker(),
-                  Map::AsElementsKind(broker()->isolate(), object(), kind));
-  }
-  if (kind == elements_kind()) return *this;
-  const ZoneVector<ObjectData*>& elements_kind_generalizations =
-      data()->AsMap()->elements_kind_generalizations();
-  for (auto data : elements_kind_generalizations) {
-    MapRef map(broker(), data);
-    if (map.elements_kind() == kind) return map;
-  }
-  return base::Optional<MapRef>();
+  if (!object->IsHeapObject()) return false;
+  return ObjectMayBeUninitialized(HeapObject::cast(*object));
 }
 
-void MapRef::SerializeForElementLoad() {
-  if (data()->should_access_heap()) return;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsMap()->SerializeForElementLoad(broker());
-}
-
-void MapRef::SerializeForElementStore() {
-  if (data()->should_access_heap()) return;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsMap()->SerializeForElementStore(broker());
-}
-
-void MapData::SerializeForElementLoad(JSHeapBroker* broker) {
-  if (serialized_for_element_load_) return;
-  serialized_for_element_load_ = true;
-
-  TraceScope tracer(broker, this, "MapData::SerializeForElementLoad");
-  SerializePrototype(broker);
-}
-
-void MapData::SerializeForElementStore(JSHeapBroker* broker) {
-  if (serialized_for_element_store_) return;
-  serialized_for_element_store_ = true;
-
-  TraceScope tracer(broker, this, "MapData::SerializeForElementStore");
-  // TODO(solanes, v8:7790): This should use MapData methods rather than
-  // constructing MapRefs, but it involves non-trivial refactoring and this
-  // method should go away anyway once the compiler is fully concurrent.
-  MapRef map(broker, this);
-  for (MapRef prototype_map = map;;) {
-    prototype_map.SerializePrototype();
-    prototype_map = prototype_map.prototype().map();
-    if (prototype_map.oddball_type() == OddballType::kNull ||
-        !map.prototype().IsJSObject() || !prototype_map.is_stable() ||
-        !IsFastElementsKind(prototype_map.elements_kind())) {
-      return;
-    }
-  }
-}
-
-bool MapRef::HasOnlyStablePrototypesWithFastElements(
-    ZoneVector<MapRef>* prototype_maps) {
-  DCHECK_NOT_NULL(prototype_maps);
-  MapRef prototype_map = prototype().map();
-  while (prototype_map.oddball_type() != OddballType::kNull) {
-    if (!prototype().IsJSObject() || !prototype_map.is_stable() ||
-        !IsFastElementsKind(prototype_map.elements_kind())) {
-      return false;
-    }
-    prototype_maps->push_back(prototype_map);
-    prototype_map = prototype_map.prototype().map();
-  }
-  return true;
-}
-
-bool MapRef::supports_fast_array_iteration() const {
-  if (data_->should_access_heap()) {
-    return SupportsFastArrayIteration(broker()->isolate(), object());
-  }
-  return data()->AsMap()->supports_fast_array_iteration();
-}
-
-bool MapRef::supports_fast_array_resize() const {
-  if (data_->should_access_heap()) {
-    return SupportsFastArrayResize(broker()->isolate(), object());
-  }
-  return data()->AsMap()->supports_fast_array_resize();
-}
-
-int JSFunctionRef::InitialMapInstanceSizeWithMinSlack() const {
-  if (data_->should_access_heap()) {
-    return object()->ComputeInstanceSizeWithMinSlack(broker()->isolate());
-  }
-  return data()->AsJSFunction()->initial_map_instance_size_with_min_slack();
-}
-
-OddballType MapRef::oddball_type() const {
-  if (instance_type() != ODDBALL_TYPE) {
-    return OddballType::kNone;
-  }
-  Factory* f = broker()->isolate()->factory();
-  if (equals(MapRef(broker(), f->undefined_map()))) {
-    return OddballType::kUndefined;
-  }
-  if (equals(MapRef(broker(), f->null_map()))) {
-    return OddballType::kNull;
-  }
-  if (equals(MapRef(broker(), f->boolean_map()))) {
-    return OddballType::kBoolean;
-  }
-  if (equals(MapRef(broker(), f->the_hole_map()))) {
-    return OddballType::kHole;
-  }
-  if (equals(MapRef(broker(), f->uninitialized_map()))) {
-    return OddballType::kUninitialized;
-  }
-  DCHECK(equals(MapRef(broker(), f->termination_exception_map())) ||
-         equals(MapRef(broker(), f->arguments_marker_map())) ||
-         equals(MapRef(broker(), f->optimized_out_map())) ||
-         equals(MapRef(broker(), f->stale_register_map())));
-  return OddballType::kOther;
-}
-
-FeedbackCellRef FeedbackVectorRef::GetClosureFeedbackCell(int index) const {
-  if (data_->should_access_heap()) {
-    FeedbackCell cell = object()->closure_feedback_cell(index);
-    Handle<FeedbackCell> cell_handle =
-        broker()->CanonicalPersistentHandle(cell);
-    // These should all be available because we request the cell for each
-    // CreateClosure bytecode.
-    ObjectData* cell_data = broker()->GetOrCreateData(cell_handle);
-    return FeedbackCellRef(broker(), cell_data);
-  }
-
-  return FeedbackCellRef(
-      broker(),
-      data()->AsFeedbackVector()->GetClosureFeedbackCell(broker(), index));
-}
-
-ObjectRef JSObjectRef::RawFastPropertyAt(FieldIndex index) const {
-  CHECK(index.is_inobject());
-  if (data_->should_access_heap()) {
-    return ObjectRef(broker(), broker()->CanonicalPersistentHandle(
-                                   object()->RawFastPropertyAt(index)));
-  }
-  JSObjectData* object_data = data()->AsJSObject();
-  return ObjectRef(broker(),
-                   object_data->GetInobjectField(index.property_index()));
-}
-
-bool AllocationSiteRef::IsFastLiteral() const {
-  if (data_->should_access_heap()) {
-    CHECK_NE(data_->kind(), ObjectDataKind::kNeverSerializedHeapObject);
-    return IsInlinableFastLiteral(
-        handle(object()->boilerplate(), broker()->isolate()));
-  }
-  return data()->AsAllocationSite()->IsFastLiteral();
-}
-
-void AllocationSiteRef::SerializeBoilerplate() {
-  if (data_->should_access_heap()) return;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsAllocationSite()->SerializeBoilerplate(broker());
-}
-
-void JSObjectRef::SerializeElements() {
-  if (data_->should_access_heap()) return;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsJSObject()->SerializeElements(broker());
-}
-
-void JSObjectRef::EnsureElementsTenured() {
-  if (data_->should_access_heap()) {
-    Handle<FixedArrayBase> object_elements = elements().value().object();
-    if (ObjectInYoungGeneration(*object_elements)) {
-      // If we would like to pretenure a fixed cow array, we must ensure that
-      // the array is already in old space, otherwise we'll create too many
-      // old-to-new-space pointers (overflowing the store buffer).
-      object_elements =
-          broker()->isolate()->factory()->CopyAndTenureFixedCOWArray(
-              Handle<FixedArray>::cast(object_elements));
-      object()->set_elements(*object_elements);
-    }
-    return;
-  }
-  CHECK(data()->AsJSObject()->cow_or_empty_elements_tenured());
-}
-
-FieldIndex MapRef::GetFieldIndexFor(InternalIndex descriptor_index) const {
-  CHECK_LT(descriptor_index.as_int(), NumberOfOwnDescriptors());
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
-    FieldIndex result = FieldIndex::ForDescriptor(*object(), descriptor_index);
-    DCHECK(result.is_inobject());
-    return result;
-  }
-  DescriptorArrayData* descriptors =
-      data()->AsMap()->instance_descriptors()->AsDescriptorArray();
-  FieldIndex result = descriptors->GetFieldIndexFor(descriptor_index);
-  DCHECK(result.is_inobject());
-  return result;
-}
-
-int MapRef::GetInObjectPropertyOffset(int i) const {
-  if (data_->should_access_heap()) {
-    return object()->GetInObjectPropertyOffset(i);
-  }
-  return (GetInObjectPropertiesStartInWords() + i) * kTaggedSize;
-}
-
-PropertyDetails MapRef::GetPropertyDetails(
-    InternalIndex descriptor_index) const {
-  CHECK_LT(descriptor_index.as_int(), NumberOfOwnDescriptors());
-  return instance_descriptors().GetPropertyDetails(descriptor_index);
-}
-
-NameRef MapRef::GetPropertyKey(InternalIndex descriptor_index) const {
-  CHECK_LT(descriptor_index.as_int(), NumberOfOwnDescriptors());
-  return instance_descriptors().GetPropertyKey(descriptor_index);
-}
-
-bool MapRef::IsFixedCowArrayMap() const {
-  Handle<Map> fixed_cow_array_map =
-      ReadOnlyRoots(broker()->isolate()).fixed_cow_array_map_handle();
-  return equals(MapRef(broker(), fixed_cow_array_map));
-}
-
-bool MapRef::IsPrimitiveMap() const {
-  return instance_type() <= LAST_PRIMITIVE_HEAP_OBJECT_TYPE;
-}
-
-MapRef MapRef::FindFieldOwner(InternalIndex descriptor_index) const {
-  CHECK_LT(descriptor_index.as_int(), NumberOfOwnDescriptors());
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
-    // TODO(solanes, v8:7790): Consider caching the result of the field owner on
-    // the descriptor array. It would be useful for same map as well as any
-    // other map sharing that descriptor array.
-    return MapRef(broker(), broker()->GetOrCreateData(object()->FindFieldOwner(
-                                broker()->isolate(), descriptor_index)));
-  }
-  DescriptorArrayData* descriptors =
-      data()->AsMap()->instance_descriptors()->AsDescriptorArray();
-  return MapRef(broker(), descriptors->FindFieldOwner(descriptor_index));
-}
-
-ObjectRef MapRef::GetFieldType(InternalIndex descriptor_index) const {
-  CHECK_LT(descriptor_index.as_int(), NumberOfOwnDescriptors());
-  return instance_descriptors().GetFieldType(descriptor_index);
-}
-
-base::Optional<ObjectRef> StringRef::GetCharAsStringOrUndefined(
-    uint32_t index, SerializationPolicy policy) const {
-  if (data_->should_access_heap()) {
-    // TODO(solanes, neis, v8:7790, v8:11012): Re-enable this optimization for
-    // concurrent inlining when we have the infrastructure to safely do so.
-    if (broker()->is_concurrent_inlining()) return base::nullopt;
-    CHECK_EQ(data_->kind(), ObjectDataKind::kUnserializedHeapObject);
-    return GetOwnElementFromHeap(broker(), object(), index, true);
-  }
-  ObjectData* element =
-      data()->AsString()->GetCharAsStringOrUndefined(broker(), index, policy);
-  if (element == nullptr) return base::nullopt;
-  return ObjectRef(broker(), element);
-}
-
-base::Optional<int> StringRef::length() const {
-  if (data_->should_access_heap()) {
-    if (data_->kind() == kNeverSerializedHeapObject &&
-        !this->IsInternalizedString()) {
-      TRACE_BROKER_MISSING(
-          broker(),
-          "length for kNeverSerialized non-internalized string " << *this);
-      return base::nullopt;
-    } else {
-      return object()->synchronized_length();
-    }
-  }
-  return data()->AsString()->length();
-}
-
-base::Optional<uint16_t> StringRef::GetFirstChar() {
-  if (data_->should_access_heap()) {
-    if (data_->kind() == kNeverSerializedHeapObject &&
-        !this->IsInternalizedString()) {
-      TRACE_BROKER_MISSING(
-          broker(),
-          "first char for kNeverSerialized non-internalized string " << *this);
-      return base::nullopt;
-    }
-
-    if (!broker()->IsMainThread()) {
-      return object()->Get(0, broker()->local_isolate());
-    } else {
-      // TODO(solanes, v8:7790): Remove this case once the inlining phase is
-      // done concurrently all the time.
-      return object()->Get(0);
-    }
-  }
-  return data()->AsString()->first_char();
-}
-
-base::Optional<double> StringRef::ToNumber() {
-  if (data_->should_access_heap()) {
-    if (data_->kind() == kNeverSerializedHeapObject &&
-        !this->IsInternalizedString()) {
-      TRACE_BROKER_MISSING(
-          broker(),
-          "number for kNeverSerialized non-internalized string " << *this);
-      return base::nullopt;
-    }
-
-    return TryStringToDouble(broker()->local_isolate(), object());
-  }
-  return data()->AsString()->to_number();
-}
-
-int ArrayBoilerplateDescriptionRef::constants_elements_length() const {
-  if (data_->should_access_heap()) {
-    return object()->constant_elements().length();
-  }
-  return data()->AsArrayBoilerplateDescription()->constants_elements_length();
-}
-
-ObjectRef FixedArrayRef::get(int i) const {
-  if (data_->should_access_heap()) {
-    return ObjectRef(broker(),
-                     broker()->CanonicalPersistentHandle(object()->get(i)));
-  }
-  return ObjectRef(broker(), data()->AsFixedArray()->Get(i));
-}
-
-Float64 FixedDoubleArrayRef::get(int i) const {
-  if (data_->should_access_heap()) {
-    return Float64::FromBits(object()->get_representation(i));
-  } else {
-    return data()->AsFixedDoubleArray()->Get(i);
-  }
-}
-
-Handle<ByteArray> BytecodeArrayRef::SourcePositionTable() const {
-  return broker()->CanonicalPersistentHandle(object()->SourcePositionTable());
-}
-
-Address BytecodeArrayRef::handler_table_address() const {
-  return reinterpret_cast<Address>(
-      object()->handler_table().GetDataStartAddress());
-}
-
-int BytecodeArrayRef::handler_table_size() const {
-  return object()->handler_table().length();
-}
-
-#define IF_ACCESS_FROM_HEAP_C(name)  \
-  if (data_->should_access_heap()) { \
-    return object()->name();         \
-  }
-
-#define IF_ACCESS_FROM_HEAP(result, name)                                      \
-  if (data_->should_access_heap()) {                                           \
-    return result##Ref(broker(),                                               \
-                       broker()->CanonicalPersistentHandle(object()->name())); \
-  }
-
-// Macros for definining a const getter that, depending on the data kind,
-// either looks into the heap or into the serialized data.
-#define BIMODAL_ACCESSOR(holder, result, name)                             \
-  result##Ref holder##Ref::name() const {                                  \
-    IF_ACCESS_FROM_HEAP(result, name);                                     \
-    return result##Ref(broker(), ObjectRef::data()->As##holder()->name()); \
-  }
-
-// Like above except that the result type is not an XYZRef.
-#define BIMODAL_ACCESSOR_C(holder, result, name)    \
-  result holder##Ref::name() const {                \
-    IF_ACCESS_FROM_HEAP_C(name);                    \
-    return ObjectRef::data()->As##holder()->name(); \
-  }
-
-// Like above but for BitFields.
-#define BIMODAL_ACCESSOR_B(holder, field, name, BitField)              \
-  typename BitField::FieldType holder##Ref::name() const {             \
-    IF_ACCESS_FROM_HEAP_C(name);                                       \
-    return BitField::decode(ObjectRef::data()->As##holder()->field()); \
-  }
-
-// Like IF_ACCESS_FROM_HEAP[_C] but we also allow direct heap access for
-// kSerialized only for methods that we identified to be safe.
-#define IF_ACCESS_FROM_HEAP_WITH_FLAG(result, name)                            \
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {          \
-    return result##Ref(broker(),                                               \
-                       broker()->CanonicalPersistentHandle(object()->name())); \
-  }
-#define IF_ACCESS_FROM_HEAP_WITH_FLAG_C(name)                         \
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) { \
-    return object()->name();                                          \
-  }
-
-// Like BIMODAL_ACCESSOR[_C] except that we force a direct heap access if
-// FLAG_turbo_direct_heap_access is true (even for kSerialized). This is because
-// we identified the method to be safe to use direct heap access, but the
-// holder##Data class still needs to be serialized.
-#define BIMODAL_ACCESSOR_WITH_FLAG(holder, result, name)                   \
-  result##Ref holder##Ref::name() const {                                  \
-    IF_ACCESS_FROM_HEAP_WITH_FLAG(result, name);                           \
-    return result##Ref(broker(), ObjectRef::data()->As##holder()->name()); \
-  }
-#define BIMODAL_ACCESSOR_WITH_FLAG_C(holder, result, name) \
-  result holder##Ref::name() const {                       \
-    IF_ACCESS_FROM_HEAP_WITH_FLAG_C(name);                 \
-    return ObjectRef::data()->As##holder()->name();        \
-  }
-#define BIMODAL_ACCESSOR_WITH_FLAG_B(holder, field, name, BitField)    \
-  typename BitField::FieldType holder##Ref::name() const {             \
-    IF_ACCESS_FROM_HEAP_WITH_FLAG_C(name);                             \
-    return BitField::decode(ObjectRef::data()->As##holder()->field()); \
-  }
-
-BIMODAL_ACCESSOR(AllocationSite, Object, nested_site)
-BIMODAL_ACCESSOR_C(AllocationSite, bool, CanInlineCall)
-BIMODAL_ACCESSOR_C(AllocationSite, bool, PointsToLiteral)
-BIMODAL_ACCESSOR_C(AllocationSite, ElementsKind, GetElementsKind)
-BIMODAL_ACCESSOR_C(AllocationSite, AllocationType, GetAllocationType)
-
-BIMODAL_ACCESSOR_C(BigInt, uint64_t, AsUint64)
-
-BIMODAL_ACCESSOR_C(BytecodeArray, int, register_count)
-BIMODAL_ACCESSOR_C(BytecodeArray, int, parameter_count)
-BIMODAL_ACCESSOR_C(BytecodeArray, interpreter::Register,
-                   incoming_new_target_or_generator_register)
-
-BIMODAL_ACCESSOR_C(FeedbackVector, double, invocation_count)
-
-BIMODAL_ACCESSOR(HeapObject, Map, map)
-
-BIMODAL_ACCESSOR_C(HeapNumber, double, value)
-
-// These JSBoundFunction fields are immutable after initialization. Moreover,
-// as long as JSObjects are still serialized on the main thread, all
-// JSBoundFunctionRefs are created at a time when the underlying objects are
-// guaranteed to be fully initialized.
-BIMODAL_ACCESSOR_WITH_FLAG(JSBoundFunction, JSReceiver, bound_target_function)
-BIMODAL_ACCESSOR_WITH_FLAG(JSBoundFunction, Object, bound_this)
-BIMODAL_ACCESSOR_WITH_FLAG(JSBoundFunction, FixedArray, bound_arguments)
-
-BIMODAL_ACCESSOR_C(JSDataView, size_t, byte_length)
-
-BIMODAL_ACCESSOR_C(JSFunction, bool, has_feedback_vector)
-BIMODAL_ACCESSOR_C(JSFunction, bool, has_initial_map)
-BIMODAL_ACCESSOR_C(JSFunction, bool, has_prototype)
-BIMODAL_ACCESSOR_C(JSFunction, bool, PrototypeRequiresRuntimeLookup)
-BIMODAL_ACCESSOR(JSFunction, Context, context)
-BIMODAL_ACCESSOR(JSFunction, NativeContext, native_context)
-BIMODAL_ACCESSOR(JSFunction, Map, initial_map)
-BIMODAL_ACCESSOR(JSFunction, Object, prototype)
-BIMODAL_ACCESSOR(JSFunction, SharedFunctionInfo, shared)
-BIMODAL_ACCESSOR(JSFunction, FeedbackCell, raw_feedback_cell)
-BIMODAL_ACCESSOR(JSFunction, FeedbackVector, feedback_vector)
-
-BIMODAL_ACCESSOR_C(JSGlobalObject, bool, IsDetached)
-
-BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field2, elements_kind,
-                             Map::Bits2::ElementsKindBits)
-BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field3, is_dictionary_map,
-                             Map::Bits3::IsDictionaryMapBit)
-BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field3, is_deprecated,
-                             Map::Bits3::IsDeprecatedBit)
-BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field3, NumberOfOwnDescriptors,
-                             Map::Bits3::NumberOfOwnDescriptorsBits)
-BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field3, is_migration_target,
-                             Map::Bits3::IsMigrationTargetBit)
-BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field, has_prototype_slot,
-                             Map::Bits1::HasPrototypeSlotBit)
-BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field, is_access_check_needed,
-                             Map::Bits1::IsAccessCheckNeededBit)
-BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field, is_callable,
-                             Map::Bits1::IsCallableBit)
-BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field, has_indexed_interceptor,
-                             Map::Bits1::HasIndexedInterceptorBit)
-BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field, is_constructor,
-                             Map::Bits1::IsConstructorBit)
-BIMODAL_ACCESSOR_WITH_FLAG_B(Map, bit_field, is_undetectable,
-                             Map::Bits1::IsUndetectableBit)
-BIMODAL_ACCESSOR_C(Map, int, instance_size)
-BIMODAL_ACCESSOR_C(Map, int, NextFreePropertyIndex)
-BIMODAL_ACCESSOR_C(Map, int, UnusedPropertyFields)
-BIMODAL_ACCESSOR_WITH_FLAG(Map, HeapObject, prototype)
-BIMODAL_ACCESSOR_WITH_FLAG_C(Map, InstanceType, instance_type)
-BIMODAL_ACCESSOR_WITH_FLAG(Map, Object, GetConstructor)
-BIMODAL_ACCESSOR_WITH_FLAG(Map, HeapObject, GetBackPointer)
-BIMODAL_ACCESSOR_C(Map, bool, is_abandoned_prototype_map)
-
-#define DEF_NATIVE_CONTEXT_ACCESSOR(type, name) \
-  BIMODAL_ACCESSOR(NativeContext, type, name)
-BROKER_NATIVE_CONTEXT_FIELDS(DEF_NATIVE_CONTEXT_ACCESSOR)
-#undef DEF_NATIVE_CONTEXT_ACCESSOR
-
-BIMODAL_ACCESSOR_C(ObjectBoilerplateDescription, int, size)
-
-BIMODAL_ACCESSOR(PropertyCell, Object, value)
-BIMODAL_ACCESSOR_C(PropertyCell, PropertyDetails, property_details)
-
-BIMODAL_ACCESSOR(RegExpBoilerplateDescription, FixedArray, data)
-BIMODAL_ACCESSOR(RegExpBoilerplateDescription, String, source)
-BIMODAL_ACCESSOR_C(RegExpBoilerplateDescription, int, flags)
-
-base::Optional<CallHandlerInfoRef> FunctionTemplateInfoRef::call_code() const {
-  if (data_->should_access_heap()) {
-    HeapObject call_code = object()->call_code(kAcquireLoad);
-    if (call_code.IsUndefined()) return base::nullopt;
-    return CallHandlerInfoRef(broker(),
-                              broker()->CanonicalPersistentHandle(call_code));
-  }
-  ObjectData* call_code = data()->AsFunctionTemplateInfo()->call_code();
-  if (!call_code) return base::nullopt;
-  return CallHandlerInfoRef(broker(), call_code);
-}
-
-bool FunctionTemplateInfoRef::is_signature_undefined() const {
-  if (data_->should_access_heap()) {
-    return object()->signature().IsUndefined(broker()->isolate());
-  }
-  return data()->AsFunctionTemplateInfo()->is_signature_undefined();
-}
-
-bool FunctionTemplateInfoRef::has_call_code() const {
-  if (data_->should_access_heap()) {
-    HeapObject call_code = object()->call_code(kAcquireLoad);
-    return !call_code.IsUndefined();
-  }
-  return data()->AsFunctionTemplateInfo()->has_call_code();
-}
-
-bool FunctionTemplateInfoRef ::accept_any_receiver() const {
-  if (data_->should_access_heap()) {
-    return object()->accept_any_receiver();
-  }
-  return ObjectRef ::data()->AsFunctionTemplateInfo()->accept_any_receiver();
-}
-
-HolderLookupResult FunctionTemplateInfoRef::LookupHolderOfExpectedType(
-    MapRef receiver_map, SerializationPolicy policy) {
-  const HolderLookupResult not_found;
-
-  if (data_->should_access_heap()) {
-    // There are currently two ways we can see a FunctionTemplateInfo on the
-    // background thread: 1.) As part of a SharedFunctionInfo and 2.) in an
-    // AccessorPair. In both cases, the FTI is fully constructed on the main
-    // thread before.
-    // TODO(nicohartmann@, v8:7790): Once the above no longer holds, we might
-    // have to use the GC predicate to check whether objects are fully
-    // initialized and safe to read.
-    if (!receiver_map.IsJSReceiverMap() ||
-        (receiver_map.is_access_check_needed() &&
-         !object()->accept_any_receiver())) {
-      return not_found;
-    }
-
-    if (!receiver_map.IsJSObjectMap()) return not_found;
-
-    DCHECK(has_call_code());
-
-    DisallowGarbageCollection no_gc;
-    HeapObject signature = object()->signature();
-    if (signature.IsUndefined()) {
-      return HolderLookupResult(CallOptimization::kHolderIsReceiver);
-    }
-    auto expected_receiver_type = FunctionTemplateInfo::cast(signature);
-    if (expected_receiver_type.IsTemplateFor(*receiver_map.object())) {
-      return HolderLookupResult(CallOptimization::kHolderIsReceiver);
-    }
-
-    if (!receiver_map.IsJSGlobalProxyMap()) return not_found;
-    if (policy == SerializationPolicy::kSerializeIfNeeded) {
-      receiver_map.SerializePrototype();
-    }
-    if (!receiver_map.serialized_prototype()) return not_found;
-    if (receiver_map.prototype().IsNull()) return not_found;
-
-    JSObject raw_prototype = JSObject::cast(*receiver_map.prototype().object());
-    if (!expected_receiver_type.IsTemplateFor(raw_prototype.map())) {
-      return not_found;
-    }
-    Handle<JSObject> prototype =
-        broker()->CanonicalPersistentHandle(raw_prototype);
-    if (ObjectData* data = broker()->TryGetOrCreateData(prototype)) {
-      return HolderLookupResult(CallOptimization::kHolderFound,
-                                JSObjectRef(broker(), data));
-    }
-
-    TRACE_BROKER_MISSING(broker(),
-                         "holder for receiver with map " << receiver_map);
-    return not_found;
-  }
-
-  FunctionTemplateInfoData* fti_data = data()->AsFunctionTemplateInfo();
-  KnownReceiversMap::iterator lookup_it =
-      fti_data->known_receivers().find(receiver_map.data());
-  if (lookup_it != fti_data->known_receivers().cend()) {
-    return lookup_it->second;
-  }
-  if (policy == SerializationPolicy::kAssumeSerialized) {
-    TRACE_BROKER_MISSING(broker(),
-                         "holder for receiver with map " << receiver_map);
-    return not_found;
-  }
-  if (!receiver_map.IsJSReceiverMap() ||
-      (receiver_map.is_access_check_needed() && !accept_any_receiver())) {
-    fti_data->known_receivers().insert({receiver_map.data(), not_found});
-    return not_found;
-  }
-
-  HolderLookupResult result;
-  CallOptimization call_optimization(broker()->isolate(), object());
-  Handle<JSObject> holder = call_optimization.LookupHolderOfExpectedType(
-      receiver_map.object(), &result.lookup);
-
-  switch (result.lookup) {
-    case CallOptimization::kHolderFound: {
-      result.holder = JSObjectRef(broker(), holder);
-      fti_data->known_receivers().insert({receiver_map.data(), result});
-      break;
-    }
-    default: {
-      DCHECK_EQ(result.holder, base::nullopt);
-      fti_data->known_receivers().insert({receiver_map.data(), result});
-    }
-  }
-  return result;
-}
-
-BIMODAL_ACCESSOR(CallHandlerInfo, Object, data)
-
-BIMODAL_ACCESSOR_C(ScopeInfo, int, ContextLength)
-BIMODAL_ACCESSOR_C(ScopeInfo, bool, HasContextExtensionSlot)
-BIMODAL_ACCESSOR_C(ScopeInfo, bool, HasOuterScopeInfo)
-BIMODAL_ACCESSOR(ScopeInfo, ScopeInfo, OuterScopeInfo)
-
-BIMODAL_ACCESSOR_C(SharedFunctionInfo, int, builtin_id)
-BytecodeArrayRef SharedFunctionInfoRef::GetBytecodeArray() const {
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
-    BytecodeArray bytecode_array;
-    if (!broker()->IsMainThread()) {
-      bytecode_array = object()->GetBytecodeArray(broker()->local_isolate());
-    } else {
-      bytecode_array = object()->GetBytecodeArray(broker()->isolate());
-    }
-    return BytecodeArrayRef(
-        broker(), broker()->CanonicalPersistentHandle(bytecode_array));
-  }
-  return BytecodeArrayRef(
-      broker(), ObjectRef ::data()->AsSharedFunctionInfo()->GetBytecodeArray());
-}
-#define DEF_SFI_ACCESSOR(type, name) \
-  BIMODAL_ACCESSOR_WITH_FLAG_C(SharedFunctionInfo, type, name)
-BROKER_SFI_FIELDS(DEF_SFI_ACCESSOR)
-#undef DEF_SFI_ACCESSOR
-SharedFunctionInfo::Inlineability SharedFunctionInfoRef::GetInlineability()
-    const {
-  if (data_->should_access_heap()) {
-    if (!broker()->IsMainThread()) {
-      return object()->GetInlineability(broker()->local_isolate());
-    } else {
-      return object()->GetInlineability(broker()->isolate());
-    }
-  }
-  return ObjectRef ::data()->AsSharedFunctionInfo()->GetInlineability();
-}
-
-base::Optional<FeedbackVectorRef> FeedbackCellRef::value() const {
-  if (data_->should_access_heap()) {
-    // Note that we use the synchronized accessor.
-    Object value = object()->value(kAcquireLoad);
-    if (!value.IsFeedbackVector()) return base::nullopt;
-    auto vector_handle = broker()->CanonicalPersistentHandle(value);
-    ObjectData* vector = broker()->TryGetOrCreateData(vector_handle);
-    if (vector) {
-      return FeedbackVectorRef(broker(), vector);
-    }
-    TRACE_BROKER_MISSING(
-        broker(),
-        "Unable to retrieve FeedbackVector from FeedbackCellRef " << *this);
-    return base::nullopt;
-  }
-  ObjectData* vector = ObjectRef::data()->AsFeedbackCell()->value();
-  return FeedbackVectorRef(broker(), vector->AsFeedbackVector());
-}
-
-base::Optional<ObjectRef> MapRef::GetStrongValue(
-    InternalIndex descriptor_index) const {
-  CHECK_LT(descriptor_index.as_int(), NumberOfOwnDescriptors());
-  return instance_descriptors().GetStrongValue(descriptor_index);
-}
-
-DescriptorArrayRef MapRef::instance_descriptors() const {
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
-    return DescriptorArrayRef(
-        broker(),
-        broker()->CanonicalPersistentHandle(
-            object()->instance_descriptors(broker()->isolate(), kRelaxedLoad)));
-  }
-
-  return DescriptorArrayRef(broker(), data()->AsMap()->instance_descriptors());
-}
-
-void MapRef::SerializeRootMap() {
-  if (data_->should_access_heap()) return;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsMap()->SerializeRootMap(broker());
-}
-
-// TODO(solanes, v8:7790): Remove base::Optional from the return type when
-// deleting serialization.
-base::Optional<MapRef> MapRef::FindRootMap() const {
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
-    // TODO(solanes): Remove the TryGetOrCreateData part when Map is moved to
-    // kNeverSerialized.
-    ObjectData* root_map =
-        broker()->TryGetOrCreateData(broker()->CanonicalPersistentHandle(
-            object()->FindRootMap(broker()->isolate())));
-    if (root_map) {
-      // TODO(solanes, v8:7790): Consider caching the result of the root map.
-      return MapRef(broker(), root_map);
-    }
-    TRACE_BROKER_MISSING(broker(), "root map for object " << *this);
-    return base::nullopt;
-  }
-  ObjectData* map_data = data()->AsMap()->FindRootMap();
-  if (map_data != nullptr) {
-    return MapRef(broker(), map_data);
-  }
-  TRACE_BROKER_MISSING(broker(), "root map for object " << *this);
-  return base::nullopt;
-}
-
-bool JSTypedArrayRef::is_on_heap() const {
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
-    // Safe to read concurrently because:
-    // - host object seen by serializer.
-    // - underlying field written 1. during initialization or 2. with
-    //   release-store.
-    return object()->is_on_heap(kAcquireLoad);
-  }
-  return data()->AsJSTypedArray()->data_ptr();
-}
-
-size_t JSTypedArrayRef::length() const {
-  CHECK(!is_on_heap());
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
-    // Safe to read concurrently because:
-    // - immutable after initialization.
-    // - host object seen by serializer.
-    return object()->length();
-  }
-  return data()->AsJSTypedArray()->length();
-}
-
-HeapObjectRef JSTypedArrayRef::buffer() const {
-  CHECK(!is_on_heap());
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
-    // Safe to read concurrently because:
-    // - immutable after initialization.
-    // - host object seen by serializer.
-    Handle<JSArrayBuffer> value =
-        broker()->CanonicalPersistentHandle(object()->buffer());
-    return JSObjectRef{broker(), value};
-  }
-  return HeapObjectRef{broker(), data()->AsJSTypedArray()->buffer()};
-}
-
-void* JSTypedArrayRef::data_ptr() const {
-  CHECK(!is_on_heap());
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
-    // Safe to read concurrently because:
-    // - host object seen by serializer.
-    // - underlying field written 1. during initialization or 2. protected by
-    //   the is_on_heap release/acquire semantics (external_pointer store
-    //   happens-before base_pointer store, and this external_pointer load
-    //   happens-after base_pointer load).
-    STATIC_ASSERT(JSTypedArray::kOffHeapDataPtrEqualsExternalPointer);
-    return object()->DataPtr();
-  }
-  return data()->AsJSTypedArray()->data_ptr();
-}
-
-bool MapRef::IsInobjectSlackTrackingInProgress() const {
-  IF_ACCESS_FROM_HEAP_WITH_FLAG_C(IsInobjectSlackTrackingInProgress);
-  return Map::Bits3::ConstructionCounterBits::decode(
-             data()->AsMap()->bit_field3()) != Map::kNoSlackTracking;
-}
-
-int MapRef::constructor_function_index() const {
-  IF_ACCESS_FROM_HEAP_C(GetConstructorFunctionIndex);
-  CHECK(IsPrimitiveMap());
-  return data()->AsMap()->constructor_function_index();
-}
-
-bool MapRef::is_stable() const {
-  IF_ACCESS_FROM_HEAP_C(is_stable);
-  return !Map::Bits3::IsUnstableBit::decode(data()->AsMap()->bit_field3());
-}
-
-bool MapRef::CanBeDeprecated() const {
-  IF_ACCESS_FROM_HEAP_C(CanBeDeprecated);
-  CHECK_GT(NumberOfOwnDescriptors(), 0);
-  return data()->AsMap()->can_be_deprecated();
-}
-
-bool MapRef::CanTransition() const {
-  IF_ACCESS_FROM_HEAP_C(CanTransition);
-  return data()->AsMap()->can_transition();
-}
-
-int MapRef::GetInObjectPropertiesStartInWords() const {
-  IF_ACCESS_FROM_HEAP_C(GetInObjectPropertiesStartInWords);
-  return data()->AsMap()->in_object_properties_start_in_words();
-}
-
-int MapRef::GetInObjectProperties() const {
-  IF_ACCESS_FROM_HEAP_C(GetInObjectProperties);
-  return data()->AsMap()->in_object_properties();
-}
-
-void ScopeInfoRef::SerializeScopeInfoChain() {
-  if (data_->should_access_heap()) return;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsScopeInfo()->SerializeScopeInfoChain(broker());
-}
-
-bool StringRef::IsExternalString() const {
-  IF_ACCESS_FROM_HEAP_C(IsExternalString);
-  return data()->AsString()->is_external_string();
-}
-
-Address CallHandlerInfoRef::callback() const {
-  if (data_->should_access_heap()) {
-    return v8::ToCData<Address>(object()->callback());
-  }
-  return HeapObjectRef::data()->AsCallHandlerInfo()->callback();
-}
-
-Address FunctionTemplateInfoRef::c_function() const {
-  if (data_->should_access_heap()) {
-    return v8::ToCData<Address>(object()->GetCFunction());
-  }
-  return HeapObjectRef::data()->AsFunctionTemplateInfo()->c_function();
-}
-
-const CFunctionInfo* FunctionTemplateInfoRef::c_signature() const {
-  if (data_->should_access_heap()) {
-    return v8::ToCData<CFunctionInfo*>(object()->GetCSignature());
-  }
-  return HeapObjectRef::data()->AsFunctionTemplateInfo()->c_signature();
-}
-
-bool StringRef::IsSeqString() const {
-  IF_ACCESS_FROM_HEAP_C(IsSeqString);
-  return data()->AsString()->is_seq_string();
-}
-
-ScopeInfoRef NativeContextRef::scope_info() const {
-  if (data_->should_access_heap()) {
-    return ScopeInfoRef(
-        broker(), broker()->CanonicalPersistentHandle(object()->scope_info()));
-  }
-  return ScopeInfoRef(broker(), data()->AsNativeContext()->scope_info());
-}
-
-SharedFunctionInfoRef FeedbackVectorRef::shared_function_info() const {
-  if (data_->should_access_heap()) {
-    return SharedFunctionInfoRef(
-        broker(),
-        broker()->CanonicalPersistentHandle(object()->shared_function_info()));
-  }
-
-  return SharedFunctionInfoRef(
-      broker(), data()->AsFeedbackVector()->shared_function_info());
-}
-
-MapRef NativeContextRef::GetFunctionMapFromIndex(int index) const {
-  DCHECK_GE(index, Context::FIRST_FUNCTION_MAP_INDEX);
-  DCHECK_LE(index, Context::LAST_FUNCTION_MAP_INDEX);
-  if (data_->should_access_heap()) {
-    return get(index).value().AsMap();
-  }
-  return MapRef(broker(), data()->AsNativeContext()->function_maps().at(
-                              index - Context::FIRST_FUNCTION_MAP_INDEX));
-}
-
-MapRef NativeContextRef::GetInitialJSArrayMap(ElementsKind kind) const {
-  switch (kind) {
-    case PACKED_SMI_ELEMENTS:
-      return js_array_packed_smi_elements_map();
-    case HOLEY_SMI_ELEMENTS:
-      return js_array_holey_smi_elements_map();
-    case PACKED_DOUBLE_ELEMENTS:
-      return js_array_packed_double_elements_map();
-    case HOLEY_DOUBLE_ELEMENTS:
-      return js_array_holey_double_elements_map();
-    case PACKED_ELEMENTS:
-      return js_array_packed_elements_map();
-    case HOLEY_ELEMENTS:
-      return js_array_holey_elements_map();
-    default:
-      UNREACHABLE();
-  }
-}
-
-base::Optional<JSFunctionRef> NativeContextRef::GetConstructorFunction(
-    const MapRef& map) const {
-  CHECK(map.IsPrimitiveMap());
-  switch (map.constructor_function_index()) {
-    case Map::kNoConstructorFunctionIndex:
-      return base::nullopt;
-    case Context::BIGINT_FUNCTION_INDEX:
-      return bigint_function();
-    case Context::BOOLEAN_FUNCTION_INDEX:
-      return boolean_function();
-    case Context::NUMBER_FUNCTION_INDEX:
-      return number_function();
-    case Context::STRING_FUNCTION_INDEX:
-      return string_function();
-    case Context::SYMBOL_FUNCTION_INDEX:
-      return symbol_function();
-    default:
-      UNREACHABLE();
-  }
-}
-
-bool ObjectRef::IsNull() const { return object()->IsNull(); }
-
-bool ObjectRef::IsNullOrUndefined() const {
-  if (IsSmi()) return false;
-  OddballType type = AsHeapObject().map().oddball_type();
-  return type == OddballType::kNull || type == OddballType::kUndefined;
-}
-
-bool ObjectRef::IsTheHole() const {
-  return IsHeapObject() &&
-         AsHeapObject().map().oddball_type() == OddballType::kHole;
-}
-
-bool ObjectRef::BooleanValue() const {
-  if (data_->should_access_heap()) {
-    return object()->BooleanValue(broker()->isolate());
-  }
-  return IsSmi() ? (AsSmi() != 0) : data()->AsHeapObject()->boolean_value();
-}
-
-Maybe<double> ObjectRef::OddballToNumber() const {
-  OddballType type = AsHeapObject().map().oddball_type();
-
-  switch (type) {
-    case OddballType::kBoolean: {
-      ObjectRef true_ref(broker(),
-                         broker()->isolate()->factory()->true_value());
-      return this->equals(true_ref) ? Just(1.0) : Just(0.0);
-      break;
-    }
-    case OddballType::kUndefined: {
-      return Just(std::numeric_limits<double>::quiet_NaN());
-      break;
-    }
-    case OddballType::kNull: {
-      return Just(0.0);
-      break;
-    }
-    default: {
-      return Nothing<double>();
-      break;
-    }
-  }
-}
-
-base::Optional<ObjectRef> JSObjectRef::GetOwnConstantElement(
-    uint32_t index, SerializationPolicy policy) const {
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
-    // `elements` are currently still serialized as members of JSObjectRef.
-    // TODO(jgruber,v8:7790): Once JSObject is no longer serialized, we must
-    // guarantee consistency between `object`, `elements_kind` and `elements`
-    // through other means (store/load order? locks? storing elements_kind in
-    // elements.map?).
-    STATIC_ASSERT(IsSerializedHeapObject<JSObject>());
-
-    base::Optional<FixedArrayBaseRef> maybe_elements_ref = elements();
-    if (!maybe_elements_ref.has_value()) {
-      TRACE_BROKER_MISSING(broker(), "JSObject::elements" << *this);
-      return {};
-    }
-
-    FixedArrayBaseRef elements_ref = maybe_elements_ref.value();
-    ElementsKind elements_kind = GetElementsKind();
-
-    DCHECK_LE(index, JSObject::kMaxElementIndex);
-
-    // See also ElementsAccessorBase::GetMaxIndex.
-    if (IsJSArray()) {
-      // For JSArrays we additionally need to check against JSArray::length.
-      // Length_unsafe is safe to use in this case since:
-      // - GetOwnConstantElement only detects a constant for JSArray holders if
-      //   the array is frozen/sealed.
-      // - Frozen/sealed arrays can't change length.
-      // - We've already seen a map with frozen/sealed elements_kinds (above);
-      // - The release-load of that map ensures we read the newest value
-      //   of `length` below.
-      uint32_t array_length;
-      if (!AsJSArray().length_unsafe().object()->ToArrayLength(&array_length)) {
-        return {};
-      }
-      if (index >= array_length) return {};
-    }
-
-    Object maybe_element;
-    auto result = ConcurrentLookupIterator::TryGetOwnConstantElement(
-        &maybe_element, broker()->isolate(), broker()->local_isolate(),
-        *object(), *elements_ref.object(), elements_kind, index);
-
-    if (result == ConcurrentLookupIterator::kGaveUp) {
-      TRACE_BROKER_MISSING(broker(), "JSObject::GetOwnConstantElement on "
-                                         << *this << " at index " << index);
-      return {};
-    } else if (result == ConcurrentLookupIterator::kNotPresent) {
-      return {};
-    }
-
-    DCHECK_EQ(result, ConcurrentLookupIterator::kPresent);
-    return ObjectRef{broker(),
-                     broker()->CanonicalPersistentHandle(maybe_element)};
-  } else {
-    ObjectData* element =
-        data()->AsJSObject()->GetOwnConstantElement(broker(), index, policy);
-    if (element == nullptr) return base::nullopt;
-    return ObjectRef(broker(), element);
-  }
-}
-
-base::Optional<ObjectRef> JSObjectRef::GetOwnFastDataProperty(
-    Representation field_representation, FieldIndex index,
-    SerializationPolicy policy) const {
-  if (data_->should_access_heap()) {
-    return GetOwnFastDataPropertyFromHeap(broker(),
-                                          Handle<JSObject>::cast(object()),
-                                          field_representation, index);
-  }
-  ObjectData* property = data()->AsJSObject()->GetOwnFastDataProperty(
-      broker(), field_representation, index, policy);
-  if (property == nullptr) return base::nullopt;
-  return ObjectRef(broker(), property);
-}
-
-ObjectRef JSObjectRef::GetOwnDictionaryProperty(
-    InternalIndex index, SerializationPolicy policy) const {
-  CHECK(index.is_found());
-  if (data_->should_access_heap()) {
-    return GetOwnDictionaryPropertyFromHeap(
-        broker(), Handle<JSObject>::cast(object()), index);
-  }
-  ObjectData* property =
-      data()->AsJSObject()->GetOwnDictionaryProperty(broker(), index, policy);
-  CHECK_NE(property, nullptr);
-  return ObjectRef(broker(), property);
-}
-
-ObjectRef JSArrayRef::GetBoilerplateLength() const {
-  // Safe to read concurrently because:
-  // - boilerplates are immutable after initialization.
-  // - boilerplates are published into the feedback vector.
-  return length_unsafe();
-}
-
-ObjectRef JSArrayRef::length_unsafe() const {
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
-    Object o = object()->length(broker()->isolate(), kRelaxedLoad);
-    return ObjectRef{broker(), broker()->CanonicalPersistentHandle(o)};
-  } else {
-    return ObjectRef{broker(), data()->AsJSArray()->length()};
-  }
-}
-
-base::Optional<ObjectRef> JSArrayRef::GetOwnCowElement(
-    FixedArrayBaseRef elements_ref, uint32_t index,
-    SerializationPolicy policy) const {
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
-    // `elements` are currently still serialized as members of JSObjectRef.
-    // TODO(jgruber,v8:7790): Remove the elements equality DCHECK below once
-    // JSObject is no longer serialized.
-    static_assert(std::is_base_of<JSObject, JSArray>::value, "");
-    STATIC_ASSERT(IsSerializedHeapObject<JSObject>());
-
-    // The elements_ref is passed in by callers to make explicit that it is
-    // also used outside of this function, and must match the `elements` used
-    // inside this function.
-    DCHECK(elements_ref.equals(elements().value()));
-
-    // Due to concurrency, the kind read here may not be consistent with
-    // `elements_ref`. But consistency is guaranteed at runtime due to the
-    // `elements` equality check in the caller.
-    ElementsKind elements_kind = GetElementsKind();
-
-    // We only inspect fixed COW arrays, which may only occur for fast
-    // smi/objects elements kinds.
-    if (!IsSmiOrObjectElementsKind(elements_kind)) return {};
-    DCHECK(IsFastElementsKind(elements_kind));
-    if (!elements_ref.map().IsFixedCowArrayMap()) return {};
-
-    // As the name says, the `length` read here is unsafe and may not match
-    // `elements`. We rely on the invariant that any `length` change will
-    // also result in an `elements` change to make this safe. The `elements`
-    // equality check in the caller thus also guards the value of `length`.
-    ObjectRef length_ref = length_unsafe();
-
-    // Likewise we only deal with smi lengths.
-    if (!length_ref.IsSmi()) return {};
-
-    base::Optional<Object> result =
-        ConcurrentLookupIterator::TryGetOwnCowElement(
-            broker()->isolate(), *elements_ref.AsFixedArray().object(),
-            elements_kind, length_ref.AsSmi(), index);
-
-    if (!result.has_value()) return {};
-
-    return ObjectRef{broker(),
-                     broker()->CanonicalPersistentHandle(result.value())};
-  } else {
-    DCHECK(!data_->should_access_heap());
-    DCHECK(!FLAG_turbo_direct_heap_access);
-
-    // Just to clarify that `elements_ref` is not used on this path.
-    // GetOwnElement accesses the serialized `elements` field on its own.
-    USE(elements_ref);
-
-    if (!elements().value().map().IsFixedCowArrayMap()) return base::nullopt;
-
-    ObjectData* element =
-        data()->AsJSArray()->GetOwnElement(broker(), index, policy);
-    if (element == nullptr) return base::nullopt;
-    return ObjectRef(broker(), element);
-  }
-}
-
-base::Optional<CellRef> SourceTextModuleRef::GetCell(int cell_index) const {
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
-    return CellRef(broker(), broker()->CanonicalPersistentHandle(
-                                 object()->GetCell(cell_index)));
-  }
-  ObjectData* cell =
-      data()->AsSourceTextModule()->GetCell(broker(), cell_index);
-  if (cell == nullptr) return base::nullopt;
-  return CellRef(broker(), cell);
-}
-
-ObjectRef SourceTextModuleRef::import_meta() const {
-  if (data_->should_access_heap()) {
-    return ObjectRef(
-        broker(), broker()->CanonicalPersistentHandle(object()->import_meta()));
-  }
-  return ObjectRef(broker(),
-                   data()->AsSourceTextModule()->GetImportMeta(broker()));
-}
-
-ObjectRef::ObjectRef(JSHeapBroker* broker, Handle<Object> object,
-                     BackgroundSerialization background_serialization,
-                     bool check_type)
-    : broker_(broker) {
-  CHECK_NE(broker->mode(), JSHeapBroker::kRetired);
-
-  data_ = broker->GetOrCreateData(object, background_serialization);
-  if (!data_) {  // TODO(mslekova): Remove once we're on the background thread.
-    object->Print();
-  }
-  CHECK_WITH_MSG(data_ != nullptr, "Object is not known to the heap broker");
-}
-
-namespace {
-OddballType GetOddballType(Isolate* isolate, Map map) {
-  if (map.instance_type() != ODDBALL_TYPE) {
-    return OddballType::kNone;
-  }
-  ReadOnlyRoots roots(isolate);
-  if (map == roots.undefined_map()) {
-    return OddballType::kUndefined;
-  }
-  if (map == roots.null_map()) {
-    return OddballType::kNull;
-  }
-  if (map == roots.boolean_map()) {
-    return OddballType::kBoolean;
-  }
-  if (map == roots.the_hole_map()) {
-    return OddballType::kHole;
-  }
-  if (map == roots.uninitialized_map()) {
-    return OddballType::kUninitialized;
-  }
-  DCHECK(map == roots.termination_exception_map() ||
-         map == roots.arguments_marker_map() ||
-         map == roots.optimized_out_map() || map == roots.stale_register_map());
-  return OddballType::kOther;
-}
-}  // namespace
-
-HeapObjectType HeapObjectRef::GetHeapObjectType() const {
-  if (data_->should_access_heap()) {
-    Map map = Handle<HeapObject>::cast(object())->map();
-    HeapObjectType::Flags flags(0);
-    if (map.is_undetectable()) flags |= HeapObjectType::kUndetectable;
-    if (map.is_callable()) flags |= HeapObjectType::kCallable;
-    return HeapObjectType(map.instance_type(), flags,
-                          GetOddballType(broker()->isolate(), map));
-  }
-  HeapObjectType::Flags flags(0);
-  if (map().is_undetectable()) flags |= HeapObjectType::kUndetectable;
-  if (map().is_callable()) flags |= HeapObjectType::kCallable;
-  return HeapObjectType(map().instance_type(), flags, map().oddball_type());
-}
-base::Optional<JSObjectRef> AllocationSiteRef::boilerplate() const {
-  if (data_->should_access_heap()) {
-    return JSObjectRef(
-        broker(), broker()->CanonicalPersistentHandle(object()->boilerplate()));
-  }
-  ObjectData* boilerplate = data()->AsAllocationSite()->boilerplate();
-  if (boilerplate) {
-    return JSObjectRef(broker(), boilerplate);
-  } else {
-    return base::nullopt;
-  }
-}
-
-ElementsKind JSObjectRef::GetElementsKind() const {
-  return map().elements_kind();
-}
-
-base::Optional<FixedArrayBaseRef> JSObjectRef::elements() const {
-  if (data_->should_access_heap()) {
-    return FixedArrayBaseRef(
-        broker(), broker()->CanonicalPersistentHandle(object()->elements()));
-  }
-  const JSObjectData* d = data()->AsJSObject();
-  if (!d->serialized_elements()) {
-    TRACE(broker(), "'elements' on " << this);
-    return base::nullopt;
-  }
-  return FixedArrayBaseRef(broker(), d->elements());
-}
-
-int FixedArrayBaseRef::length() const {
-  IF_ACCESS_FROM_HEAP_C(length);
-  return data()->AsFixedArrayBase()->length();
-}
-
-ObjectData* FixedArrayData::Get(int i) const {
-  CHECK_LT(i, static_cast<int>(contents_.size()));
-  CHECK_NOT_NULL(contents_[i]);
-  return contents_[i];
-}
-
-Float64 FixedDoubleArrayData::Get(int i) const {
-  CHECK_LT(i, static_cast<int>(contents_.size()));
-  return contents_[i];
-}
-
-PropertyDetails DescriptorArrayRef::GetPropertyDetails(
-    InternalIndex descriptor_index) const {
-  if (data_->should_access_heap()) {
-    return object()->GetDetails(descriptor_index);
-  }
-  return data()->AsDescriptorArray()->GetPropertyDetails(descriptor_index);
-}
-
-NameRef DescriptorArrayRef::GetPropertyKey(
-    InternalIndex descriptor_index) const {
-  if (data_->should_access_heap()) {
-    NameRef result(broker(), broker()->CanonicalPersistentHandle(
-                                 object()->GetKey(descriptor_index)));
-    CHECK(result.IsUniqueName());
-    return result;
-  }
-  return NameRef(broker(),
-                 data()->AsDescriptorArray()->GetPropertyKey(descriptor_index));
-}
-
-ObjectRef DescriptorArrayRef::GetFieldType(
-    InternalIndex descriptor_index) const {
-  if (data_->should_access_heap()) {
-    // This method only gets called for the creation of FieldTypeDependencies.
-    // These calls happen when the broker is either disabled or serializing,
-    // which means that GetOrCreateData would be able to successfully create the
-    // ObjectRef for the cases where we haven't seen the FieldType before.
-    DCHECK(broker()->mode() == JSHeapBroker::kDisabled ||
-           broker()->mode() == JSHeapBroker::kSerializing);
-    return ObjectRef(broker(), broker()->CanonicalPersistentHandle(
-                                   object()->GetFieldType(descriptor_index)));
-  }
-  return ObjectRef(broker(),
-                   data()->AsDescriptorArray()->GetFieldType(descriptor_index));
-}
-
-base::Optional<ObjectRef> DescriptorArrayRef::GetStrongValue(
-    InternalIndex descriptor_index) const {
-  if (data_->should_access_heap()) {
-    HeapObject heap_object;
-    if (object()
-            ->GetValue(descriptor_index)
-            .GetHeapObjectIfStrong(&heap_object)) {
-      // Since the descriptors in the descriptor array can be changed in-place
-      // via DescriptorArray::Replace, we might get a value that we haven't seen
-      // before.
-      ObjectData* data = broker()->TryGetOrCreateData(
-          broker()->CanonicalPersistentHandle(heap_object));
-      if (data) return ObjectRef(broker(), data);
-
-      TRACE_BROKER_MISSING(broker(), "strong value for descriptor array "
-                                         << *this << " at index "
-                                         << descriptor_index.as_int());
-      // Fall through to the base::nullopt below.
-    }
-    return base::nullopt;
-  }
-  ObjectData* value =
-      data()->AsDescriptorArray()->GetStrongValue(descriptor_index);
-  if (!value) return base::nullopt;
-  return ObjectRef(broker(), value);
-}
-
-base::Optional<SharedFunctionInfoRef> FeedbackCellRef::shared_function_info()
-    const {
-  if (value()) {
-    FeedbackVectorRef vector = *value();
-    if (vector.serialized()) {
-      return vector.shared_function_info();
-    }
-  }
-  return base::nullopt;
-}
-
-void FeedbackVectorRef::Serialize() {
-  if (data_->should_access_heap()) return;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsFeedbackVector()->Serialize(broker());
-}
-
-bool FeedbackVectorRef::serialized() const {
-  if (data_->should_access_heap()) return true;
-  return data()->AsFeedbackVector()->serialized();
-}
-
-bool NameRef::IsUniqueName() const {
-  // Must match Name::IsUniqueName.
-  return IsInternalizedString() || IsSymbol();
-}
-
-void RegExpBoilerplateDescriptionRef::Serialize() {
-  if (data_->should_access_heap()) {
-    // Even if the regexp boilerplate object itself is no longer serialized,
-    // the `data` still is and thus we need to make sure to visit it.
-    // TODO(jgruber,v8:7790): Remove once it is no longer a serialized type.
-    STATIC_ASSERT(IsSerializedHeapObject<FixedArray>());
-    FixedArrayRef data_ref{
-        broker(), broker()->CanonicalPersistentHandle(object()->data())};
-  } else {
-    CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-    HeapObjectRef::data()->AsRegExpBoilerplateDescription()->Serialize(
-        broker());
-  }
-}
-
-Handle<Object> ObjectRef::object() const {
-#ifdef DEBUG
-  if (broker()->mode() == JSHeapBroker::kSerialized &&
-      data_->used_status == ObjectData::Usage::kUnused) {
-    data_->used_status = ObjectData::Usage::kOnlyIdentityUsed;
-  }
-#endif  // DEBUG
-  return data_->object();
-}
-
-#ifdef DEBUG
-#define DEF_OBJECT_GETTER(T)                                                 \
-  Handle<T> T##Ref::object() const {                                         \
-    if (broker()->mode() == JSHeapBroker::kSerialized &&                     \
-        data_->used_status == ObjectData::Usage::kUnused) {                  \
-      data_->used_status = ObjectData::Usage::kOnlyIdentityUsed;             \
-    }                                                                        \
-    return Handle<T>(reinterpret_cast<Address*>(data_->object().address())); \
-  }
-#else
-#define DEF_OBJECT_GETTER(T)                                                 \
-  Handle<T> T##Ref::object() const {                                         \
-    return Handle<T>(reinterpret_cast<Address*>(data_->object().address())); \
-  }
-#endif  // DEBUG
-
-HEAP_BROKER_SERIALIZED_OBJECT_LIST(DEF_OBJECT_GETTER)
-HEAP_BROKER_POSSIBLY_BACKGROUND_SERIALIZED_OBJECT_LIST(DEF_OBJECT_GETTER)
-HEAP_BROKER_BACKGROUND_SERIALIZED_OBJECT_LIST(DEF_OBJECT_GETTER)
-HEAP_BROKER_NEVER_SERIALIZED_OBJECT_LIST(DEF_OBJECT_GETTER)
-#undef DEF_OBJECT_GETTER
-
-JSHeapBroker* ObjectRef::broker() const { return broker_; }
-
-ObjectData* ObjectRef::data() const {
-  switch (broker()->mode()) {
-    case JSHeapBroker::kDisabled:
-      CHECK_NE(data_->kind(), kSerializedHeapObject);
-      return data_;
-    case JSHeapBroker::kSerializing:
-      CHECK_NE(data_->kind(), kUnserializedHeapObject);
-      return data_;
-    case JSHeapBroker::kSerialized:
-#ifdef DEBUG
-      data_->used_status = ObjectData::Usage::kDataUsed;
-#endif  // DEBUG
-      CHECK_NE(data_->kind(), kUnserializedHeapObject);
-      return data_;
-    case JSHeapBroker::kRetired:
-      UNREACHABLE();
-  }
-}
-
-Reduction NoChangeBecauseOfMissingData(JSHeapBroker* broker,
-                                       const char* function, int line) {
-  TRACE_MISSING(broker, "data in function " << function << " at line " << line);
-  return AdvancedReducer::NoChange();
-}
-
-NativeContextData::NativeContextData(JSHeapBroker* broker, ObjectData** storage,
-                                     Handle<NativeContext> object)
-    : ContextData(broker, storage, object),
-      state_(State::kUnserialized),
-      function_maps_(broker->zone()) {}
-
-void NativeContextData::Serialize(JSHeapBroker* broker) {
-  if (state_ != State::kUnserialized) return;
-  state_ = State::kSerializedOnMainThread;
-
-  TraceScope tracer(broker, this, "NativeContextData::Serialize");
-  Handle<NativeContext> context = Handle<NativeContext>::cast(object());
-
-#define SERIALIZE_MEMBER(type, name)                                          \
-  DCHECK_NULL(name##_);                                                       \
-  name##_ = broker->GetOrCreateData(context->name());                         \
-  if (!name##_->should_access_heap()) {                                       \
-    if (name##_->IsMap() &&                                                   \
-        !InstanceTypeChecker::IsContext(name##_->AsMap()->instance_type())) { \
-      name##_->AsMap()->SerializeConstructor(broker);                         \
-    }                                                                         \
-    if (name##_->IsJSFunction()) {                                            \
-      name##_->AsJSFunction()->Serialize(broker);                             \
-    }                                                                         \
-  }
-  BROKER_COMPULSORY_NATIVE_CONTEXT_FIELDS(SERIALIZE_MEMBER)
-  if (!broker->is_isolate_bootstrapping()) {
-    BROKER_OPTIONAL_NATIVE_CONTEXT_FIELDS(SERIALIZE_MEMBER)
-  }
-#undef SERIALIZE_MEMBER
-
-  if (!bound_function_with_constructor_map_->should_access_heap()) {
-    bound_function_with_constructor_map_->AsMap()->SerializePrototype(broker);
-  }
-  if (!bound_function_without_constructor_map_->should_access_heap()) {
-    bound_function_without_constructor_map_->AsMap()->SerializePrototype(
-        broker);
-  }
-
-  scope_info_ = broker->GetOrCreateData(context->scope_info());
-}
-
-void NativeContextData::SerializeOnBackground(JSHeapBroker* broker) {
-  if (state_ == State::kFullySerialized) return;
-  DCHECK_EQ(state_, State::kSerializedOnMainThread);
-  state_ = State::kSerializedOnMainThread;
-
-  UnparkedScopeIfNeeded unparked_scope(broker);
-  TraceScope tracer(broker, this, "NativeContextData::SerializeOnBackground");
-  Handle<NativeContext> context = Handle<NativeContext>::cast(object());
-
-  constexpr auto kAllowed = ObjectRef::BackgroundSerialization::kAllowed;
-#define SERIALIZE_MEMBER(type, name)                            \
-  DCHECK_NULL(name##_);                                         \
-  name##_ = broker->GetOrCreateData(context->name(), kAllowed); \
-  if (!name##_->should_access_heap()) {                         \
-    DCHECK(!name##_->IsJSFunction());                           \
-  }
-  BROKER_COMPULSORY_BACKGROUND_NATIVE_CONTEXT_FIELDS(SERIALIZE_MEMBER)
-  if (!broker->is_isolate_bootstrapping()) {
-    BROKER_OPTIONAL_BACKGROUND_NATIVE_CONTEXT_FIELDS(SERIALIZE_MEMBER)
-  }
-#undef SERIALIZE_MEMBER
-
-  DCHECK(function_maps_.empty());
-  int const first = Context::FIRST_FUNCTION_MAP_INDEX;
-  int const last = Context::LAST_FUNCTION_MAP_INDEX;
-  function_maps_.reserve(last + 1 - first);
-  for (int i = first; i <= last; ++i) {
-    function_maps_.push_back(
-        broker->GetOrCreateData(context->get(i), kAllowed));
-  }
-}
-
-void JSFunctionRef::Serialize() {
-  if (data_->should_access_heap()) return;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsJSFunction()->Serialize(broker());
-}
-
-void JSFunctionRef::SerializeCodeAndFeedback() {
-  if (data_->should_access_heap()) return;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsJSFunction()->SerializeCodeAndFeedback(broker());
-}
-
-bool JSBoundFunctionRef::serialized() const {
-  if (data_->should_access_heap()) return true;
-  return data()->AsJSBoundFunction()->serialized();
-}
-
-bool JSFunctionRef::serialized() const {
-  if (data_->should_access_heap()) return true;
-  return data()->AsJSFunction()->serialized();
-}
-
-bool JSFunctionRef::serialized_code_and_feedback() const {
-  if (data_->should_access_heap()) return true;
-  return data()->AsJSFunction()->serialized_code_and_feedback();
-}
-
-CodeRef JSFunctionRef::code() const {
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
-    return CodeRef(broker(), broker()->CanonicalPersistentHandle(
-                                 object()->code(kAcquireLoad)));
-  }
-
-  return CodeRef(broker(), ObjectRef::data()->AsJSFunction()->code());
-}
-
-void SharedFunctionInfoRef::SerializeFunctionTemplateInfo() {
-  if (data_->should_access_heap()) return;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsSharedFunctionInfo()->SerializeFunctionTemplateInfo(broker());
-}
-
-void SharedFunctionInfoRef::SerializeScopeInfoChain() {
-  if (data_->should_access_heap()) return;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsSharedFunctionInfo()->SerializeScopeInfoChain(broker());
-}
-
-base::Optional<FunctionTemplateInfoRef>
-SharedFunctionInfoRef::function_template_info() const {
-  if (data_->should_access_heap()) {
-    if (object()->IsApiFunction()) {
-      ObjectData* data =
-          broker()->TryGetOrCreateData(broker()->CanonicalPersistentHandle(
-              object()->function_data(kAcquireLoad)));
-      if (data == nullptr) return base::nullopt;
-      return FunctionTemplateInfoRef(broker(), data, true);
-    }
-    return base::nullopt;
-  }
-  ObjectData* function_template_info =
-      data()->AsSharedFunctionInfo()->function_template_info();
-  if (!function_template_info) return base::nullopt;
-  return FunctionTemplateInfoRef(broker(), function_template_info);
-}
-
-int SharedFunctionInfoRef::context_header_size() const {
-  IF_ACCESS_FROM_HEAP_C(scope_info().ContextHeaderLength);
-  return data()->AsSharedFunctionInfo()->context_header_size();
-}
-
-ScopeInfoRef SharedFunctionInfoRef::scope_info() const {
-  if (data_->should_access_heap()) {
-    return ScopeInfoRef(
-        broker(), broker()->CanonicalPersistentHandle(object()->scope_info()));
-  }
-  return ScopeInfoRef(broker(), data()->AsSharedFunctionInfo()->scope_info());
-}
-
-void JSObjectRef::SerializeObjectCreateMap() {
-  if (data_->should_access_heap()) return;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsJSObject()->SerializeObjectCreateMap(broker());
-}
-
-void MapRef::SerializeOwnDescriptor(InternalIndex descriptor_index) {
-  CHECK_LT(descriptor_index.as_int(), NumberOfOwnDescriptors());
-  if (data_->should_access_heap()) return;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsMap()->SerializeOwnDescriptor(broker(), descriptor_index);
-}
-
-bool MapRef::serialized_own_descriptor(InternalIndex descriptor_index) const {
-  CHECK_LT(descriptor_index.as_int(), NumberOfOwnDescriptors());
-  if (data_->should_access_heap()) return true;
-  ObjectData* maybe_desc_array_data = data()->AsMap()->instance_descriptors();
-  if (!maybe_desc_array_data) return false;
-  if (maybe_desc_array_data->should_access_heap()) return true;
-  DescriptorArrayData* desc_array_data =
-      maybe_desc_array_data->AsDescriptorArray();
-  return desc_array_data->serialized_descriptor(descriptor_index);
-}
-
-void MapRef::SerializeBackPointer() {
-  if (data_->should_access_heap()) return;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsMap()->SerializeBackPointer(broker());
-}
-
-void MapRef::SerializePrototype() {
-  if (data_->should_access_heap()) return;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsMap()->SerializePrototype(broker());
-}
-
-bool MapRef::serialized_prototype() const {
-  if (data_->should_access_heap()) return true;
-  CHECK_NE(broker()->mode(), JSHeapBroker::kDisabled);
-  return data()->AsMap()->serialized_prototype();
-}
-
-void SourceTextModuleRef::Serialize() {
-  if (data_->should_access_heap()) return;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsSourceTextModule()->Serialize(broker());
-}
-
-void NativeContextRef::Serialize() {
-  if (data_->should_access_heap()) return;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsNativeContext()->Serialize(broker());
-}
-
-void NativeContextRef::SerializeOnBackground() {
-  if (data_->should_access_heap()) return;
-  CHECK(broker()->mode() == JSHeapBroker::kSerializing ||
-        broker()->mode() == JSHeapBroker::kSerialized);
-  data()->AsNativeContext()->SerializeOnBackground(broker());
-}
-
-void JSTypedArrayRef::Serialize() {
-  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
-    // Even if the typed array object itself is no longer serialized (besides
-    // the JSObject parts), the `buffer` field still is and thus we need to
-    // make sure to visit it.
-    // TODO(jgruber,v8:7790): Remove once JSObject is no longer serialized.
-    static_assert(
-        std::is_base_of<JSObject, decltype(object()->buffer())>::value, "");
-    STATIC_ASSERT(IsSerializedHeapObject<JSObject>());
-    JSObjectRef data_ref{
-        broker(), broker()->CanonicalPersistentHandle(object()->buffer())};
-  } else {
-    CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-    data()->AsJSTypedArray()->Serialize(broker());
-  }
-}
-
-bool JSTypedArrayRef::serialized() const {
-  CHECK_NE(broker()->mode(), JSHeapBroker::kDisabled);
-  return data()->AsJSTypedArray()->serialized();
-}
-
-bool JSTypedArrayRef::ShouldHaveBeenSerialized() const {
-  if (FLAG_turbo_direct_heap_access) return false;
-  return ObjectRef::ShouldHaveBeenSerialized();
-}
-
-bool JSBoundFunctionRef::Serialize() {
-  if (data_->should_access_heap()) return true;
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  return data()->AsJSBoundFunction()->Serialize(broker());
-}
-
-bool PropertyCellRef::Serialize() const {
-  if (data_->should_access_heap()) return true;
-  CHECK(broker()->mode() == JSHeapBroker::kSerializing ||
-        broker()->mode() == JSHeapBroker::kSerialized);
-  return data()->AsPropertyCell()->Serialize(broker());
-}
-
-void FunctionTemplateInfoRef::SerializeCallCode() {
-  if (data_->should_access_heap()) {
-    CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-    // CallHandlerInfo::data may still hold a serialized heap object, so we
-    // have to make the broker aware of it.
-    // TODO(v8:7790): Remove this case once ObjectRef is never serialized.
-    Handle<HeapObject> call_code(object()->call_code(kAcquireLoad),
-                                 broker()->isolate());
-    if (call_code->IsCallHandlerInfo()) {
-      broker()->GetOrCreateData(
-          Handle<CallHandlerInfo>::cast(call_code)->data());
-    }
-    return;
-  }
-  CHECK_EQ(broker()->mode(), JSHeapBroker::kSerializing);
-  data()->AsFunctionTemplateInfo()->SerializeCallCode(broker());
-}
-
-base::Optional<PropertyCellRef> JSGlobalObjectRef::GetPropertyCell(
-    NameRef const& name, SerializationPolicy policy) const {
-  if (data_->should_access_heap()) {
-    return GetPropertyCellFromHeap(broker(), name.object());
-  }
-  ObjectData* property_cell_data = data()->AsJSGlobalObject()->GetPropertyCell(
-      broker(), name.data(), policy);
-  if (property_cell_data == nullptr) return base::nullopt;
-  return PropertyCellRef(broker(), property_cell_data);
+bool JSHeapBroker::ObjectMayBeUninitialized(HeapObject object) const {
+  return !IsMainThread() && isolate()->heap()->IsPendingAllocation(object);
 }
 
 bool CanInlineElementAccess(MapRef const& map) {
@@ -4942,7 +459,7 @@ ElementAccessFeedback::ElementAccessFeedback(Zone* zone,
 bool ElementAccessFeedback::HasOnlyStringMaps(JSHeapBroker* broker) const {
   for (auto const& group : transition_groups()) {
     for (Handle<Map> map : group) {
-      if (!MapRef(broker, map).IsStringMap()) return false;
+      if (!MakeRef(broker, map).IsStringMap()) return false;
     }
   }
   return true;
@@ -5008,6 +525,7 @@ bool JSHeapBroker::FeedbackIsInsufficient(FeedbackSource const& source) const {
 }
 
 namespace {
+
 // Remove unupdatable and abandoned prototype maps in-place.
 void FilterRelevantReceiverMaps(Isolate* isolate, MapHandles* maps) {
   auto in = maps->begin();
@@ -5074,6 +592,7 @@ bool HasMigrationTargets(const MapHandles& maps) {
   }
   return false;
 }
+
 }  // namespace
 
 bool JSHeapBroker::CanUseFeedback(const FeedbackNexus& nexus) const {
@@ -5166,12 +685,12 @@ ProcessedFeedback const& JSHeapBroker::ReadFeedbackForGlobalAccess(
         isolate(), target_native_context().script_context_table().object(),
         script_context_index);
     {
-      ObjectRef contents(this,
-                         handle(context->get(context_slot_index), isolate()));
+      ObjectRef contents =
+          MakeRef(this, handle(context->get(context_slot_index), isolate()));
       CHECK(!contents.equals(
-          ObjectRef(this, isolate()->factory()->the_hole_value())));
+          MakeRef<Object>(this, isolate()->factory()->the_hole_value())));
     }
-    ContextRef context_ref(this, context);
+    ContextRef context_ref = MakeRef(this, context);
     if (immutable) {
       context_ref.get(context_slot_index,
                       SerializationPolicy::kSerializeIfNeeded);
@@ -5183,11 +702,10 @@ ProcessedFeedback const& JSHeapBroker::ReadFeedbackForGlobalAccess(
   CHECK(feedback_value->IsPropertyCell());
   // The wanted name belongs (or did belong) to a property on the global
   // object and the feedback is the cell holding its value.
-  PropertyCellRef cell(this, Handle<PropertyCell>::cast(feedback_value));
-  ObjectRef(
-      this,
-      CanonicalPersistentHandle(
-          Handle<PropertyCell>::cast(feedback_value)->value(kAcquireLoad)));
+  PropertyCellRef cell =
+      MakeRef(this, Handle<PropertyCell>::cast(feedback_value));
+  MakeRef(this,
+          Handle<PropertyCell>::cast(feedback_value)->value(kAcquireLoad));
   return *zone()->New<GlobalAccessFeedback>(cell, nexus.kind());
 }
 
@@ -5228,7 +746,7 @@ ProcessedFeedback const& JSHeapBroker::ReadFeedbackForInstanceOf(
     MaybeHandle<JSObject> maybe_constructor = nexus.GetConstructorFeedback();
     Handle<JSObject> constructor;
     if (maybe_constructor.ToHandle(&constructor)) {
-      optional_constructor = JSObjectRef(this, constructor);
+      optional_constructor = MakeRef(this, constructor);
     }
   }
   return *zone()->New<InstanceOfFeedback>(optional_constructor, nexus.kind());
@@ -5244,7 +762,8 @@ ProcessedFeedback const& JSHeapBroker::ReadFeedbackForArrayOrObjectLiteral(
     return NewInsufficientFeedback(nexus.kind());
   }
 
-  AllocationSiteRef site(this, handle(object, isolate()));
+  AllocationSiteRef site =
+      MakeRef(this, handle(AllocationSite::cast(object), isolate()));
   if (site.IsFastLiteral()) {
     site.SerializeBoilerplate();
   }
@@ -5262,7 +781,8 @@ ProcessedFeedback const& JSHeapBroker::ReadFeedbackForRegExpLiteral(
     return NewInsufficientFeedback(nexus.kind());
   }
 
-  RegExpBoilerplateDescriptionRef boilerplate(this, handle(object, isolate()));
+  RegExpBoilerplateDescriptionRef boilerplate = MakeRef(
+      this, handle(RegExpBoilerplateDescription::cast(object), isolate()));
   boilerplate.Serialize();
   return *zone()->New<RegExpLiteralFeedback>(boilerplate, nexus.kind());
 }
@@ -5277,7 +797,7 @@ ProcessedFeedback const& JSHeapBroker::ReadFeedbackForTemplateObject(
     return NewInsufficientFeedback(nexus.kind());
   }
 
-  JSArrayRef array(this, handle(object, isolate()));
+  JSArrayRef array = MakeRef(this, handle(JSArray::cast(object), isolate()));
   return *zone()->New<TemplateObjectFeedback>(array, nexus.kind());
 }
 
@@ -5297,12 +817,14 @@ ProcessedFeedback const& JSHeapBroker::ReadFeedbackForCall(
     MaybeObject maybe_target = nexus.GetFeedback();
     HeapObject target_object;
     if (maybe_target->GetHeapObject(&target_object)) {
-      target_ref = HeapObjectRef(this, handle(target_object, isolate()));
+      target_ref = MakeRef(this, handle(target_object, isolate()));
     }
   }
   float frequency = nexus.ComputeCallFrequency();
   SpeculationMode mode = nexus.GetSpeculationMode();
-  return *zone()->New<CallFeedback>(target_ref, frequency, mode, nexus.kind());
+  CallFeedbackContent content = nexus.GetCallFeedbackContent();
+  return *zone()->New<CallFeedback>(target_ref, frequency, mode, content,
+                                    nexus.kind());
 }
 
 BinaryOperationHint JSHeapBroker::GetFeedbackForBinaryOperation(
@@ -5468,7 +990,7 @@ ElementAccessFeedback const& JSHeapBroker::ProcessFeedbackMapsForElementAccess(
   MapHandles possible_transition_targets;
   possible_transition_targets.reserve(maps.size());
   for (Handle<Map> map : maps) {
-    MapRef map_ref(this, map);
+    MapRef map_ref = MakeRef(this, map);
     map_ref.SerializeRootMap();
 
     if (CanInlineElementAccess(map_ref) &&
@@ -5531,23 +1053,11 @@ void ElementAccessFeedback::AddGroup(TransitionGroup&& group) {
 #endif
 }
 
-std::ostream& operator<<(std::ostream& os, const ObjectRef& ref) {
-  if (!FLAG_concurrent_recompilation) {
-    // We cannot be in a background thread so it's safe to read the heap.
-    AllowHandleDereference allow_handle_dereference;
-    return os << ref.data() << " {" << ref.object() << "}";
-  } else if (ref.data_->should_access_heap()) {
-    return os << ref.data() << " {" << ref.object() << "}";
-  } else {
-    return os << ref.data();
-  }
-}
-
 base::Optional<NameRef> JSHeapBroker::GetNameFeedback(
     FeedbackNexus const& nexus) {
   Name raw_name = nexus.GetName();
   if (raw_name.is_null()) return base::nullopt;
-  return NameRef(this, handle(raw_name, isolate()));
+  return MakeRef(this, handle(raw_name, isolate()));
 }
 
 PropertyAccessInfo JSHeapBroker::GetPropertyAccessInfo(
@@ -5557,7 +1067,8 @@ PropertyAccessInfo JSHeapBroker::GetPropertyAccessInfo(
   auto it = property_access_infos_.find(target);
   if (it != property_access_infos_.end()) return it->second;
 
-  if (policy == SerializationPolicy::kAssumeSerialized) {
+  if (policy == SerializationPolicy::kAssumeSerialized &&
+      !FLAG_turbo_concurrent_get_property_access_info) {
     TRACE_BROKER_MISSING(this, "PropertyAccessInfo for "
                                    << access_mode << " of property " << name
                                    << " on map " << map);
@@ -5569,7 +1080,8 @@ PropertyAccessInfo JSHeapBroker::GetPropertyAccessInfo(
   PropertyAccessInfo access_info = factory.ComputePropertyAccessInfo(
       map.object(), name.object(), access_mode);
   if (is_concurrent_inlining_) {
-    CHECK_EQ(mode(), kSerializing);
+    CHECK_IMPLIES(!FLAG_turbo_concurrent_get_property_access_info,
+                  mode() == kSerializing);
     TRACE(this, "Storing PropertyAccessInfo for "
                     << access_mode << " of property " << name << " on map "
                     << map);
@@ -5664,27 +1176,7 @@ TemplateObjectFeedback const& ProcessedFeedback::AsTemplateObject() const {
   return *static_cast<TemplateObjectFeedback const*>(this);
 }
 
-unsigned CodeRef::GetInlinedBytecodeSize() const {
-  if (data_->should_access_heap()) {
-    unsigned value = object()->inlined_bytecode_size();
-    if (value > 0) {
-      // Don't report inlined bytecode size if the code object was already
-      // deoptimized.
-      value = object()->marked_for_deoptimization() ? 0 : value;
-    }
-    return value;
-  }
-
-  return ObjectRef::data()->AsCode()->inlined_bytecode_size();
-}
-
-#undef BIMODAL_ACCESSOR
-#undef BIMODAL_ACCESSOR_B
-#undef BIMODAL_ACCESSOR_C
-#undef IF_ACCESS_FROM_HEAP
-#undef IF_ACCESS_FROM_HEAP_C
 #undef TRACE
-#undef TRACE_MISSING
 
 }  // namespace compiler
 }  // namespace internal
diff --git a/chromium/v8/src/compiler/js-heap-broker.h b/chromium/v8/src/compiler/js-heap-broker.h
index 32b09dddbc8..cc842ca8e6d 100644
--- a/chromium/v8/src/compiler/js-heap-broker.h
+++ b/chromium/v8/src/compiler/js-heap-broker.h
@@ -7,10 +7,12 @@
 
 #include "src/base/compiler-specific.h"
 #include "src/base/optional.h"
+#include "src/base/platform/mutex.h"
 #include "src/common/globals.h"
 #include "src/compiler/access-info.h"
 #include "src/compiler/feedback-source.h"
 #include "src/compiler/globals.h"
+#include "src/compiler/heap-refs.h"
 #include "src/compiler/processed-feedback.h"
 #include "src/compiler/refs-map.h"
 #include "src/compiler/serializer-hints.h"
@@ -78,6 +80,18 @@ struct PropertyAccessTarget {
   };
 };
 
+enum GetOrCreateDataFlag {
+  // If set, a failure to create the data object results in a crash.
+  kCrashOnError = 1 << 0,
+  // If set, data construction assumes that the given object is protected by
+  // a memory fence (e.g. acquire-release) and thus fields required for
+  // construction (like Object::map) are safe to read. The protection can
+  // extend to some other situations as well.
+  kAssumeMemoryFence = 1 << 1,
+};
+using GetOrCreateDataFlags = base::Flags<GetOrCreateDataFlag>;
+DEFINE_OPERATORS_FOR_FLAGS(GetOrCreateDataFlags)
+
 class V8_EXPORT_PRIVATE JSHeapBroker {
  public:
   JSHeapBroker(Isolate* isolate, Zone* broker_zone, bool tracing_enabled,
@@ -98,7 +112,7 @@ class V8_EXPORT_PRIVATE JSHeapBroker {
   }
   void SetTargetNativeContextRef(Handle<NativeContext> native_context);
 
-  void InitializeAndStartSerializing(Handle<NativeContext> native_context);
+  void InitializeAndStartSerializing();
 
   Isolate* isolate() const { return isolate_; }
   Zone* zone() const { return zone_; }
@@ -106,7 +120,8 @@ class V8_EXPORT_PRIVATE JSHeapBroker {
   bool is_concurrent_inlining() const { return is_concurrent_inlining_; }
   bool is_isolate_bootstrapping() const { return is_isolate_bootstrapping_; }
   bool is_native_context_independent() const {
-    return code_kind_ == CodeKind::NATIVE_CONTEXT_INDEPENDENT;
+    // TODO(jgruber,v8:8888): Remove dependent code.
+    return false;
   }
   bool generate_full_feedback_collection() const {
     // NCI code currently collects full feedback.
@@ -145,29 +160,25 @@ class V8_EXPORT_PRIVATE JSHeapBroker {
   void PrintRefsAnalysis() const;
 #endif  // DEBUG
 
-  // Retruns the handle from root index table for read only heap objects.
+  // Returns the handle from root index table for read only heap objects.
   Handle<Object> GetRootHandle(Object object);
 
   // Never returns nullptr.
-  ObjectData* GetOrCreateData(
-      Handle<Object>,
-      ObjectRef::BackgroundSerialization background_serialization =
-          ObjectRef::BackgroundSerialization::kDisallowed);
-  // Like the previous but wraps argument in handle first (for convenience).
-  ObjectData* GetOrCreateData(
-      Object, ObjectRef::BackgroundSerialization background_serialization =
-                  ObjectRef::BackgroundSerialization::kDisallowed);
+  ObjectData* GetOrCreateData(Handle<Object> object,
+                              GetOrCreateDataFlags flags = {});
+  ObjectData* GetOrCreateData(Object object, GetOrCreateDataFlags flags = {});
 
   // Gets data only if we have it. However, thin wrappers will be created for
   // smis, read-only objects and never-serialized objects.
-  ObjectData* TryGetOrCreateData(
-      Handle<Object>, bool crash_on_error = false,
-      ObjectRef::BackgroundSerialization background_serialization =
-          ObjectRef::BackgroundSerialization::kDisallowed);
+  ObjectData* TryGetOrCreateData(Handle<Object> object,
+                                 GetOrCreateDataFlags flags = {});
+  ObjectData* TryGetOrCreateData(Object object,
+                                 GetOrCreateDataFlags flags = {});
 
   // Check if {object} is any native context's %ArrayPrototype% or
   // %ObjectPrototype%.
   bool IsArrayOrObjectPrototype(const JSObjectRef& object) const;
+  bool IsArrayOrObjectPrototype(Handle<JSObject> object) const;
 
   bool HasFeedback(FeedbackSource const& source) const;
   void SetFeedback(FeedbackSource const& source,
@@ -240,6 +251,25 @@ class V8_EXPORT_PRIVATE JSHeapBroker {
       FeedbackSource const& source,
       SerializationPolicy policy = SerializationPolicy::kAssumeSerialized);
 
+  // Used to separate the problem of a concurrent GetPropertyAccessInfo (GPAI)
+  // from serialization. GPAI is currently called both during the serialization
+  // phase, and on the background thread. While some crucial objects (like
+  // JSObject) still must be serialized, we do the following:
+  // - Run GPAI during serialization to discover and serialize required objects.
+  // - After the serialization phase, clear cached property access infos.
+  // - On the background thread, rerun GPAI in a concurrent setting. The cache
+  //   has been cleared, thus the actual logic runs again.
+  // Once all required object kinds no longer require serialization, this
+  // should be removed together with all GPAI calls during serialization.
+  void ClearCachedPropertyAccessInfos() {
+    CHECK(FLAG_turbo_concurrent_get_property_access_info);
+    property_access_infos_.clear();
+  }
+
+  // As above, clear cached ObjectData that can be reconstructed, i.e. is
+  // either never-serialized or background-serialized.
+  void ClearReconstructibleData();
+
   StringRef GetTypedArrayStringTag(ElementsKind kind);
 
   bool ShouldBeSerializedForCompilation(const SharedFunctionInfoRef& shared,
@@ -257,6 +287,14 @@ class V8_EXPORT_PRIVATE JSHeapBroker {
 
   LocalIsolate* local_isolate() const { return local_isolate_; }
 
+  // TODO(jgruber): Consider always having local_isolate_ set to a real value.
+  // This seems not entirely trivial since we currently reset local_isolate_ to
+  // nullptr at some point in the JSHeapBroker lifecycle.
+  LocalIsolate* local_isolate_or_isolate() const {
+    return local_isolate() != nullptr ? local_isolate()
+                                      : isolate()->AsLocalIsolate();
+  }
+
   // Return the corresponding canonical persistent handle for {object}. Create
   // one if it does not exist.
   // If we have the canonical map, we can create the canonical & persistent
@@ -291,6 +329,7 @@ class V8_EXPORT_PRIVATE JSHeapBroker {
 
   template <typename T>
   Handle<T> CanonicalPersistentHandle(Handle<T> object) {
+    if (object.is_null()) return object;  // Can't deref a null handle.
     return CanonicalPersistentHandle<T>(*object);
   }
 
@@ -313,6 +352,34 @@ class V8_EXPORT_PRIVATE JSHeapBroker {
 
   RootIndexMap const& root_index_map() { return root_index_map_; }
 
+  // Locks {mutex} through the duration of this scope iff it is the first
+  // occurrence. This is done to have a recursive shared lock on {mutex}.
+  class V8_NODISCARD MapUpdaterGuardIfNeeded final {
+   public:
+    explicit MapUpdaterGuardIfNeeded(JSHeapBroker* ptr,
+                                     base::SharedMutex* mutex)
+        : ptr_(ptr),
+          initial_map_updater_mutex_depth_(ptr->map_updater_mutex_depth_),
+          shared_mutex(mutex, should_lock()) {
+      ptr_->map_updater_mutex_depth_++;
+    }
+
+    ~MapUpdaterGuardIfNeeded() {
+      ptr_->map_updater_mutex_depth_--;
+      DCHECK_EQ(initial_map_updater_mutex_depth_,
+                ptr_->map_updater_mutex_depth_);
+    }
+
+    // Whether the MapUpdater mutex should be physically locked (if not, we
+    // already hold the lock).
+    bool should_lock() const { return initial_map_updater_mutex_depth_ == 0; }
+
+   private:
+    JSHeapBroker* const ptr_;
+    const int initial_map_updater_mutex_depth_;
+    base::SharedMutexGuardIf<base::kShared> shared_mutex;
+  };
+
  private:
   friend class HeapObjectRef;
   friend class ObjectRef;
@@ -323,6 +390,7 @@ class V8_EXPORT_PRIVATE JSHeapBroker {
   // thus safe to read from a memory safety perspective. The converse does not
   // necessarily hold.
   bool ObjectMayBeUninitialized(Handle<Object> object) const;
+  bool ObjectMayBeUninitialized(HeapObject object) const;
 
   bool CanUseFeedback(const FeedbackNexus& nexus) const;
   const ProcessedFeedback& NewInsufficientFeedback(FeedbackSlotKind kind) const;
@@ -427,9 +495,19 @@ class V8_EXPORT_PRIVATE JSHeapBroker {
   };
   ZoneMultimap<SerializedFunction, HintsVector> serialized_functions_;
 
-  static const size_t kMaxSerializedFunctionsCacheSize = 200;
-  static const uint32_t kMinimalRefsBucketCount = 8;     // must be power of 2
-  static const uint32_t kInitialRefsBucketCount = 1024;  // must be power of 2
+  // The MapUpdater mutex is used in recursive patterns; for example,
+  // ComputePropertyAccessInfo may call itself recursively. Thus we need to
+  // emulate a recursive mutex, which we do by checking if this heap broker
+  // instance already holds the mutex when a lock is requested. This field
+  // holds the locking depth, i.e. how many times the mutex has been
+  // recursively locked. Only the outermost locker actually locks underneath.
+  int map_updater_mutex_depth_ = 0;
+
+  static constexpr size_t kMaxSerializedFunctionsCacheSize = 200;
+  static constexpr uint32_t kMinimalRefsBucketCount = 8;
+  STATIC_ASSERT(base::bits::IsPowerOfTwo(kMinimalRefsBucketCount));
+  static constexpr uint32_t kInitialRefsBucketCount = 1024;
+  STATIC_ASSERT(base::bits::IsPowerOfTwo(kInitialRefsBucketCount));
 };
 
 class V8_NODISCARD TraceScope {
@@ -490,6 +568,65 @@ class V8_NODISCARD UnparkedScopeIfNeeded {
   base::Optional<UnparkedScope> unparked_scope;
 };
 
+// Usage:
+//
+//  base::Optional<FooRef> ref = TryMakeRef(broker, o);
+//  if (!ref.has_value()) return {};  // bailout
+//
+// or
+//
+//  FooRef ref = MakeRef(broker, o);
+template <class T,
+          typename = std::enable_if_t<std::is_convertible<T*, Object*>::value>>
+base::Optional<typename ref_traits<T>::ref_type> TryMakeRef(
+    JSHeapBroker* broker, T object, GetOrCreateDataFlags flags = {}) {
+  ObjectData* data = broker->TryGetOrCreateData(object, flags);
+  if (data == nullptr) {
+    TRACE_BROKER_MISSING(broker, "ObjectData for " << Brief(object));
+    return {};
+  }
+  return {typename ref_traits<T>::ref_type(broker, data)};
+}
+
+template <class T,
+          typename = std::enable_if_t<std::is_convertible<T*, Object*>::value>>
+base::Optional<typename ref_traits<T>::ref_type> TryMakeRef(
+    JSHeapBroker* broker, Handle<T> object, GetOrCreateDataFlags flags = {}) {
+  ObjectData* data = broker->TryGetOrCreateData(object, flags);
+  if (data == nullptr) {
+    TRACE_BROKER_MISSING(broker, "ObjectData for " << Brief(*object));
+    return {};
+  }
+  return {typename ref_traits<T>::ref_type(broker, data)};
+}
+
+template <class T,
+          typename = std::enable_if_t<std::is_convertible<T*, Object*>::value>>
+typename ref_traits<T>::ref_type MakeRef(JSHeapBroker* broker, T object) {
+  return TryMakeRef(broker, object).value();
+}
+
+template <class T,
+          typename = std::enable_if_t<std::is_convertible<T*, Object*>::value>>
+typename ref_traits<T>::ref_type MakeRef(JSHeapBroker* broker,
+                                         Handle<T> object) {
+  return TryMakeRef(broker, object).value();
+}
+
+template <class T,
+          typename = std::enable_if_t<std::is_convertible<T*, Object*>::value>>
+typename ref_traits<T>::ref_type MakeRefAssumeMemoryFence(JSHeapBroker* broker,
+                                                          T object) {
+  return TryMakeRef(broker, object, kAssumeMemoryFence).value();
+}
+
+template <class T,
+          typename = std::enable_if_t<std::is_convertible<T*, Object*>::value>>
+typename ref_traits<T>::ref_type MakeRefAssumeMemoryFence(JSHeapBroker* broker,
+                                                          Handle<T> object) {
+  return TryMakeRef(broker, object, kAssumeMemoryFence).value();
+}
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/compiler/js-heap-copy-reducer.cc b/chromium/v8/src/compiler/js-heap-copy-reducer.cc
index 3b45b9d82b4..b8f6274741f 100644
--- a/chromium/v8/src/compiler/js-heap-copy-reducer.cc
+++ b/chromium/v8/src/compiler/js-heap-copy-reducer.cc
@@ -28,7 +28,7 @@ JSHeapBroker* JSHeapCopyReducer::broker() { return broker_; }
 Reduction JSHeapCopyReducer::Reduce(Node* node) {
   switch (node->opcode()) {
     case IrOpcode::kCheckClosure: {
-      FeedbackCellRef cell(broker(), FeedbackCellOf(node->op()));
+      FeedbackCellRef cell = MakeRef(broker(), FeedbackCellOf(node->op()));
       base::Optional<FeedbackVectorRef> feedback_vector = cell.value();
       if (feedback_vector.has_value()) {
         feedback_vector->Serialize();
@@ -36,7 +36,7 @@ Reduction JSHeapCopyReducer::Reduce(Node* node) {
       break;
     }
     case IrOpcode::kHeapConstant: {
-      ObjectRef object(broker(), HeapConstantOf(node->op()));
+      ObjectRef object = MakeRef(broker(), HeapConstantOf(node->op()));
       if (object.IsJSFunction()) object.AsJSFunction().Serialize();
       if (object.IsJSObject()) {
         object.AsJSObject().SerializeObjectCreateMap();
@@ -49,34 +49,33 @@ Reduction JSHeapCopyReducer::Reduce(Node* node) {
     case IrOpcode::kJSCreateArray: {
       CreateArrayParameters const& p = CreateArrayParametersOf(node->op());
       Handle<AllocationSite> site;
-      if (p.site().ToHandle(&site)) AllocationSiteRef(broker(), site);
+      if (p.site().ToHandle(&site)) MakeRef(broker(), site);
       break;
     }
     case IrOpcode::kJSCreateArguments: {
       Node* const frame_state = NodeProperties::GetFrameStateInput(node);
       FrameStateInfo state_info = FrameStateInfoOf(frame_state->op());
-      SharedFunctionInfoRef shared(broker(),
-                                   state_info.shared_info().ToHandleChecked());
+      MakeRef(broker(), state_info.shared_info().ToHandleChecked());
       break;
     }
     case IrOpcode::kJSCreateBlockContext: {
-      ScopeInfoRef(broker(), ScopeInfoOf(node->op()));
+      MakeRef(broker(), ScopeInfoOf(node->op()));
       break;
     }
     case IrOpcode::kJSCreateBoundFunction: {
       CreateBoundFunctionParameters const& p =
           CreateBoundFunctionParametersOf(node->op());
-      MapRef(broker(), p.map());
+      MakeRef(broker(), p.map());
       break;
     }
     case IrOpcode::kJSCreateCatchContext: {
-      ScopeInfoRef(broker(), ScopeInfoOf(node->op()));
+      MakeRef(broker(), ScopeInfoOf(node->op()));
       break;
     }
     case IrOpcode::kJSCreateClosure: {
       CreateClosureParameters const& p = CreateClosureParametersOf(node->op());
-      SharedFunctionInfoRef(broker(), p.shared_info());
-      HeapObjectRef(broker(), p.code());
+      MakeRef(broker(), p.shared_info());
+      MakeRef(broker(), p.code());
       break;
     }
     case IrOpcode::kJSCreateEmptyLiteralArray: {
@@ -133,7 +132,7 @@ Reduction JSHeapCopyReducer::Reduce(Node* node) {
     case IrOpcode::kJSCreateFunctionContext: {
       CreateFunctionContextParameters const& p =
           CreateFunctionContextParametersOf(node->op());
-      ScopeInfoRef(broker(), p.scope_info());
+      MakeRef(broker(), p.scope_info());
       break;
     }
     case IrOpcode::kJSCreateLiteralArray:
@@ -154,18 +153,18 @@ Reduction JSHeapCopyReducer::Reduce(Node* node) {
     case IrOpcode::kJSGetTemplateObject: {
       GetTemplateObjectParameters const& p =
           GetTemplateObjectParametersOf(node->op());
-      SharedFunctionInfoRef(broker(), p.shared());
-      TemplateObjectDescriptionRef(broker(), p.description());
+      MakeRef(broker(), p.shared());
+      MakeRef(broker(), p.description());
       broker()->ProcessFeedbackForTemplateObject(p.feedback());
       break;
     }
     case IrOpcode::kJSCreateWithContext: {
-      ScopeInfoRef(broker(), ScopeInfoOf(node->op()));
+      MakeRef(broker(), ScopeInfoOf(node->op()));
       break;
     }
     case IrOpcode::kJSLoadNamed: {
       NamedAccess const& p = NamedAccessOf(node->op());
-      NameRef name(broker(), p.name());
+      NameRef name = MakeRef(broker(), p.name());
       if (p.feedback().IsValid()) {
         broker()->ProcessFeedbackForPropertyAccess(p.feedback(),
                                                    AccessMode::kLoad, name);
@@ -174,7 +173,7 @@ Reduction JSHeapCopyReducer::Reduce(Node* node) {
     }
     case IrOpcode::kJSLoadNamedFromSuper: {
       NamedAccess const& p = NamedAccessOf(node->op());
-      NameRef name(broker(), p.name());
+      NameRef name = MakeRef(broker(), p.name());
       if (p.feedback().IsValid()) {
         broker()->ProcessFeedbackForPropertyAccess(p.feedback(),
                                                    AccessMode::kLoad, name);
@@ -183,7 +182,7 @@ Reduction JSHeapCopyReducer::Reduce(Node* node) {
     }
     case IrOpcode::kJSStoreNamed: {
       NamedAccess const& p = NamedAccessOf(node->op());
-      NameRef name(broker(), p.name());
+      MakeRef(broker(), p.name());
       break;
     }
     case IrOpcode::kStoreField:
@@ -191,32 +190,32 @@ Reduction JSHeapCopyReducer::Reduce(Node* node) {
       FieldAccess access = FieldAccessOf(node->op());
       Handle<Map> map_handle;
       if (access.map.ToHandle(&map_handle)) {
-        MapRef(broker(), map_handle);
+        MakeRef(broker(), map_handle);
       }
       Handle<Name> name_handle;
       if (access.name.ToHandle(&name_handle)) {
-        NameRef(broker(), name_handle);
+        MakeRef(broker(), name_handle);
       }
       break;
     }
     case IrOpcode::kMapGuard: {
       ZoneHandleSet<Map> const& maps = MapGuardMapsOf(node->op());
       for (Handle<Map> map : maps) {
-        MapRef(broker(), map);
+        MakeRef(broker(), map);
       }
       break;
     }
     case IrOpcode::kCheckMaps: {
       ZoneHandleSet<Map> const& maps = CheckMapsParametersOf(node->op()).maps();
       for (Handle<Map> map : maps) {
-        MapRef(broker(), map);
+        MakeRef(broker(), map);
       }
       break;
     }
     case IrOpcode::kCompareMaps: {
       ZoneHandleSet<Map> const& maps = CompareMapsParametersOf(node->op());
       for (Handle<Map> map : maps) {
-        MapRef(broker(), map);
+        MakeRef(broker(), map);
       }
       break;
     }
diff --git a/chromium/v8/src/compiler/js-inlining-heuristic.cc b/chromium/v8/src/compiler/js-inlining-heuristic.cc
index 5777719107c..8115f8e565a 100644
--- a/chromium/v8/src/compiler/js-inlining-heuristic.cc
+++ b/chromium/v8/src/compiler/js-inlining-heuristic.cc
@@ -110,7 +110,7 @@ JSInliningHeuristic::Candidate JSInliningHeuristic::CollectFunctions(
   }
   if (m.IsCheckClosure()) {
     DCHECK(!out.functions[0].has_value());
-    FeedbackCellRef feedback_cell(broker(), FeedbackCellOf(m.op()));
+    FeedbackCellRef feedback_cell = MakeRef(broker(), FeedbackCellOf(m.op()));
     SharedFunctionInfoRef shared_info = *feedback_cell.shared_function_info();
     out.shared_info = shared_info;
     if (CanConsiderForInlining(broker(), shared_info, *feedback_cell.value())) {
@@ -124,7 +124,7 @@ JSInliningHeuristic::Candidate JSInliningHeuristic::CollectFunctions(
     JSCreateClosureNode n(callee);
     CreateClosureParameters const& p = n.Parameters();
     FeedbackCellRef feedback_cell = n.GetFeedbackCellRefChecked(broker());
-    SharedFunctionInfoRef shared_info(broker(), p.shared_info());
+    SharedFunctionInfoRef shared_info = MakeRef(broker(), p.shared_info());
     out.shared_info = shared_info;
     if (feedback_cell.value().has_value() &&
         CanConsiderForInlining(broker(), shared_info, *feedback_cell.value())) {
diff --git a/chromium/v8/src/compiler/js-inlining.cc b/chromium/v8/src/compiler/js-inlining.cc
index 6e64f2b6777..e55efde5d87 100644
--- a/chromium/v8/src/compiler/js-inlining.cc
+++ b/chromium/v8/src/compiler/js-inlining.cc
@@ -335,7 +335,7 @@ base::Optional<SharedFunctionInfoRef> JSInliner::DetermineCallTarget(
     FeedbackCellRef cell = n.GetFeedbackCellRefChecked(broker());
     return cell.shared_function_info();
   } else if (match.IsCheckClosure()) {
-    FeedbackCellRef cell(broker(), FeedbackCellOf(match.op()));
+    FeedbackCellRef cell = MakeRef(broker(), FeedbackCellOf(match.op()));
     return cell.shared_function_info();
   }
 
@@ -373,7 +373,7 @@ FeedbackCellRef JSInliner::DetermineCallContext(Node* node,
     *context_out = NodeProperties::GetContextInput(match.node());
     return cell;
   } else if (match.IsCheckClosure()) {
-    FeedbackCellRef cell(broker(), FeedbackCellOf(match.op()));
+    FeedbackCellRef cell = MakeRef(broker(), FeedbackCellOf(match.op()));
 
     Node* effect = NodeProperties::GetEffectInput(node);
     Node* control = NodeProperties::GetControlInput(node);
@@ -475,7 +475,8 @@ Reduction JSInliner::ReduceJSCall(Node* node) {
   if (!shared_info.has_value()) return NoChange();
   DCHECK(shared_info->IsInlineable());
 
-  SharedFunctionInfoRef outer_shared_info(broker(), info_->shared_info());
+  SharedFunctionInfoRef outer_shared_info =
+      MakeRef(broker(), info_->shared_info());
 
   // Constructor must be constructable.
   if (node->opcode() == IrOpcode::kJSConstruct &&
diff --git a/chromium/v8/src/compiler/js-intrinsic-lowering.cc b/chromium/v8/src/compiler/js-intrinsic-lowering.cc
index 449136051bc..803d55cc271 100644
--- a/chromium/v8/src/compiler/js-intrinsic-lowering.cc
+++ b/chromium/v8/src/compiler/js-intrinsic-lowering.cc
@@ -30,11 +30,15 @@ Reduction JSIntrinsicLowering::Reduce(Node* node) {
   if (node->opcode() != IrOpcode::kJSCallRuntime) return NoChange();
   const Runtime::Function* const f =
       Runtime::FunctionForId(CallRuntimeParametersOf(node->op()).id());
-  if (f->function_id == Runtime::kTurbofanStaticAssert) {
-    return ReduceTurbofanStaticAssert(node);
-  }
-  if (f->function_id == Runtime::kIsBeingInterpreted) {
-    return ReduceIsBeingInterpreted(node);
+  switch (f->function_id) {
+    case Runtime::kIsBeingInterpreted:
+      return ReduceIsBeingInterpreted(node);
+    case Runtime::kTurbofanStaticAssert:
+      return ReduceTurbofanStaticAssert(node);
+    case Runtime::kVerifyType:
+      return ReduceVerifyType(node);
+    default:
+      break;
   }
   if (f->intrinsic_type != Runtime::IntrinsicType::INLINE) return NoChange();
   switch (f->function_id) {
@@ -80,8 +84,6 @@ Reduction JSIntrinsicLowering::Reduce(Node* node) {
       return ReduceToLength(node);
     case Runtime::kInlineToObject:
       return ReduceToObject(node);
-    case Runtime::kInlineToString:
-      return ReduceToString(node);
     case Runtime::kInlineCall:
       return ReduceCall(node);
     case Runtime::kInlineIncBlockCounter:
@@ -290,6 +292,10 @@ Reduction JSIntrinsicLowering::ReduceTurbofanStaticAssert(Node* node) {
   return Changed(jsgraph_->UndefinedConstant());
 }
 
+Reduction JSIntrinsicLowering::ReduceVerifyType(Node* node) {
+  return Change(node, simplified()->VerifyType());
+}
+
 Reduction JSIntrinsicLowering::ReduceIsBeingInterpreted(Node* node) {
   RelaxEffectsAndControls(node);
   return Changed(jsgraph_->FalseConstant());
diff --git a/chromium/v8/src/compiler/js-intrinsic-lowering.h b/chromium/v8/src/compiler/js-intrinsic-lowering.h
index 3deeb5685e7..f2d4dbccf2c 100644
--- a/chromium/v8/src/compiler/js-intrinsic-lowering.h
+++ b/chromium/v8/src/compiler/js-intrinsic-lowering.h
@@ -60,6 +60,7 @@ class V8_EXPORT_PRIVATE JSIntrinsicLowering final
   Reduction ReduceIsSmi(Node* node);
   Reduction ReduceIsBeingInterpreted(Node* node);
   Reduction ReduceTurbofanStaticAssert(Node* node);
+  Reduction ReduceVerifyType(Node* node);
   Reduction ReduceToLength(Node* node);
   Reduction ReduceToObject(Node* node);
   Reduction ReduceToString(Node* node);
diff --git a/chromium/v8/src/compiler/js-native-context-specialization.cc b/chromium/v8/src/compiler/js-native-context-specialization.cc
index 3d9290a0bf9..8c372d34534 100644
--- a/chromium/v8/src/compiler/js-native-context-specialization.cc
+++ b/chromium/v8/src/compiler/js-native-context-specialization.cc
@@ -10,6 +10,7 @@
 #include "src/codegen/string-constants.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/access-info.h"
+#include "src/compiler/allocation-builder-inl.h"
 #include "src/compiler/allocation-builder.h"
 #include "src/compiler/compilation-dependencies.h"
 #include "src/compiler/js-graph.h"
@@ -20,7 +21,6 @@
 #include "src/compiler/property-access-builder.h"
 #include "src/compiler/type-cache.h"
 #include "src/execution/isolate-inl.h"
-#include "src/numbers/dtoa.h"
 #include "src/objects/feedback-vector.h"
 #include "src/objects/field-index-inl.h"
 #include "src/objects/heap-number.h"
@@ -36,7 +36,7 @@ namespace {
 
 bool HasNumberMaps(JSHeapBroker* broker, ZoneVector<Handle<Map>> const& maps) {
   for (auto map : maps) {
-    MapRef map_ref(broker, map);
+    MapRef map_ref = MakeRef(broker, map);
     if (map_ref.IsHeapNumberMap()) return true;
   }
   return false;
@@ -45,7 +45,7 @@ bool HasNumberMaps(JSHeapBroker* broker, ZoneVector<Handle<Map>> const& maps) {
 bool HasOnlyJSArrayMaps(JSHeapBroker* broker,
                         ZoneVector<Handle<Map>> const& maps) {
   for (auto map : maps) {
-    MapRef map_ref(broker, map);
+    MapRef map_ref = MakeRef(broker, map);
     if (!map_ref.IsJSArrayMap()) return false;
   }
   return true;
@@ -139,7 +139,7 @@ base::Optional<size_t> JSNativeContextSpecialization::GetMaxStringLength(
 
   NumberMatcher number_matcher(node);
   if (number_matcher.HasResolvedValue()) {
-    return kBase10MaximalLength + 1;
+    return kMaxDoubleStringLength;
   }
 
   // We don't support objects with possibly monkey-patched prototype.toString
@@ -228,12 +228,17 @@ Reduction JSNativeContextSpecialization::ReduceJSAsyncFunctionEnter(
 
   // Create the JSAsyncFunctionObject based on the SharedFunctionInfo
   // extracted from the top-most frame in {frame_state}.
-  SharedFunctionInfoRef shared(
+  SharedFunctionInfoRef shared = MakeRef(
       broker(),
       FrameStateInfoOf(frame_state->op()).shared_info().ToHandleChecked());
   DCHECK(shared.is_compiled());
   int register_count = shared.internal_formal_parameter_count() +
                        shared.GetBytecodeArray().register_count();
+  MapRef fixed_array_map = MakeRef(broker(), factory()->fixed_array_map());
+  AllocationBuilder ab(jsgraph(), effect, control);
+  if (!ab.CanAllocateArray(register_count, fixed_array_map)) {
+    return NoChange();
+  }
   Node* value = effect =
       graph()->NewNode(javascript()->CreateAsyncFunctionObject(register_count),
                        closure, receiver, promise, context, effect, control);
@@ -359,19 +364,15 @@ Reduction JSNativeContextSpecialization::ReduceJSGetSuperConstructor(
   }
   JSFunctionRef function = m.Ref(broker()).AsJSFunction();
   MapRef function_map = function.map();
-  if (function_map.ShouldHaveBeenSerialized() &&
-      !function_map.serialized_prototype()) {
-    TRACE_BROKER_MISSING(broker(), "data for map " << function_map);
-    return NoChange();
-  }
-  HeapObjectRef function_prototype = function_map.prototype();
+  base::Optional<HeapObjectRef> function_prototype = function_map.prototype();
+  if (!function_prototype.has_value()) return NoChange();
 
   // We can constant-fold the super constructor access if the
   // {function}s map is stable, i.e. we can use a code dependency
   // to guard against [[Prototype]] changes of {function}.
   if (function_map.is_stable()) {
     dependencies()->DependOnStableMap(function_map);
-    Node* value = jsgraph()->Constant(function_prototype);
+    Node* value = jsgraph()->Constant(*function_prototype);
     ReplaceWithValue(node, value);
     return Replace(value);
   }
@@ -407,15 +408,15 @@ Reduction JSNativeContextSpecialization::ReduceJSInstanceOf(Node* node) {
     return NoChange();
   }
 
-  JSObjectRef receiver_ref(broker(), receiver);
+  JSObjectRef receiver_ref = MakeRef(broker(), receiver);
   MapRef receiver_map = receiver_ref.map();
 
   PropertyAccessInfo access_info = PropertyAccessInfo::Invalid(graph()->zone());
   if (broker()->is_concurrent_inlining()) {
     access_info = broker()->GetPropertyAccessInfo(
         receiver_map,
-        NameRef(broker(), isolate()->factory()->has_instance_symbol()),
-        AccessMode::kLoad);
+        MakeRef(broker(), isolate()->factory()->has_instance_symbol()),
+        AccessMode::kLoad, dependencies());
   } else {
     AccessInfoFactory access_info_factory(broker(), dependencies(),
                                           graph()->zone());
@@ -457,7 +458,7 @@ Reduction JSNativeContextSpecialization::ReduceJSInstanceOf(Node* node) {
     Handle<JSObject> holder;
     bool found_on_proto = access_info.holder().ToHandle(&holder);
     JSObjectRef holder_ref =
-        found_on_proto ? JSObjectRef(broker(), holder) : receiver_ref;
+        found_on_proto ? MakeRef(broker(), holder) : receiver_ref;
     base::Optional<ObjectRef> constant = holder_ref.GetOwnFastDataProperty(
         access_info.field_representation(), access_info.field_index());
     if (!constant.has_value() || !constant->IsHeapObject() ||
@@ -467,7 +468,7 @@ Reduction JSNativeContextSpecialization::ReduceJSInstanceOf(Node* node) {
     if (found_on_proto) {
       dependencies()->DependOnStablePrototypeChains(
           access_info.lookup_start_object_maps(), kStartAtPrototype,
-          JSObjectRef(broker(), holder));
+          MakeRef(broker(), holder));
     }
 
     // Check that {constructor} is actually {receiver}.
@@ -535,7 +536,7 @@ JSNativeContextSpecialization::InferHasInPrototypeChain(
   bool all = true;
   bool none = true;
   for (size_t i = 0; i < receiver_maps.size(); ++i) {
-    MapRef map(broker(), receiver_maps[i]);
+    MapRef map = MakeRef(broker(), receiver_maps[i]);
     if (result == NodeProperties::kUnreliableMaps && !map.is_stable()) {
       return kMayBeInPrototypeChain;
     }
@@ -547,15 +548,13 @@ JSNativeContextSpecialization::InferHasInPrototypeChain(
         all = false;
         break;
       }
-      if (map.ShouldHaveBeenSerialized() && !map.serialized_prototype()) {
-        TRACE_BROKER_MISSING(broker(), "prototype data for map " << map);
-        return kMayBeInPrototypeChain;
-      }
-      if (map.prototype().equals(prototype)) {
+      base::Optional<HeapObjectRef> map_prototype = map.prototype();
+      if (!map_prototype.has_value()) return kMayBeInPrototypeChain;
+      if (map_prototype->equals(prototype)) {
         none = false;
         break;
       }
-      map = map.prototype().map();
+      map = map_prototype->map();
       // TODO(v8:11457) Support dictionary mode protoypes here.
       if (!map.is_stable() || map.is_dictionary_map())
         return kMayBeInPrototypeChain;
@@ -628,10 +627,7 @@ Reduction JSNativeContextSpecialization::ReduceJSOrdinaryHasInstance(
     // OrdinaryHasInstance on bound functions turns into a recursive invocation
     // of the instanceof operator again.
     JSBoundFunctionRef function = m.Ref(broker()).AsJSBoundFunction();
-    if (function.ShouldHaveBeenSerialized() && !function.serialized()) {
-      TRACE_BROKER_MISSING(broker(), "data for JSBoundFunction " << function);
-      return NoChange();
-    }
+    if (!function.serialized()) return NoChange();
 
     JSReceiverRef bound_target_function = function.bound_target_function();
 
@@ -651,10 +647,7 @@ Reduction JSNativeContextSpecialization::ReduceJSOrdinaryHasInstance(
     // Optimize if we currently know the "prototype" property.
 
     JSFunctionRef function = m.Ref(broker()).AsJSFunction();
-    if (function.ShouldHaveBeenSerialized() && !function.serialized()) {
-      TRACE_BROKER_MISSING(broker(), "data for JSFunction " << function);
-      return NoChange();
-    }
+    if (!function.serialized()) return NoChange();
 
     // TODO(neis): Remove the has_prototype_slot condition once the broker is
     // always enabled.
@@ -736,10 +729,10 @@ Reduction JSNativeContextSpecialization::ReduceJSResolvePromise(Node* node) {
   } else {
     // Obtain pre-computed access infos from the broker.
     for (auto map : resolution_maps) {
-      MapRef map_ref(broker(), map);
+      MapRef map_ref = MakeRef(broker(), map);
       access_infos.push_back(broker()->GetPropertyAccessInfo(
-          map_ref, NameRef(broker(), isolate()->factory()->then_string()),
-          AccessMode::kLoad));
+          map_ref, MakeRef(broker(), isolate()->factory()->then_string()),
+          AccessMode::kLoad, dependencies()));
     }
   }
   PropertyAccessInfo access_info =
@@ -865,7 +858,7 @@ Reduction JSNativeContextSpecialization::ReduceGlobalAccess(
         simplified()->CheckMaps(
             CheckMapsFlag::kNone,
             ZoneHandleSet<Map>(
-                HeapObjectRef(broker(), global_proxy()).map().object())),
+                MakeRef(broker(), global_proxy()).map().object())),
         lookup_start_object, effect, control);
   }
 
@@ -1035,7 +1028,7 @@ Reduction JSNativeContextSpecialization::ReduceJSLoadGlobal(Node* node) {
     return Replace(value);
   } else if (feedback.IsPropertyCell()) {
     return ReduceGlobalAccess(node, nullptr, nullptr, nullptr,
-                              NameRef(broker(), p.name()), AccessMode::kLoad,
+                              MakeRef(broker(), p.name()), AccessMode::kLoad,
                               nullptr, feedback.property_cell());
   } else {
     DCHECK(feedback.IsMegamorphic());
@@ -1066,7 +1059,7 @@ Reduction JSNativeContextSpecialization::ReduceJSStoreGlobal(Node* node) {
     return Replace(value);
   } else if (feedback.IsPropertyCell()) {
     return ReduceGlobalAccess(node, nullptr, nullptr, value,
-                              NameRef(broker(), p.name()), AccessMode::kStore,
+                              MakeRef(broker(), p.name()), AccessMode::kStore,
                               nullptr, feedback.property_cell());
   } else {
     DCHECK(feedback.IsMegamorphic());
@@ -1188,7 +1181,8 @@ Reduction JSNativeContextSpecialization::ReduceNamedAccess(
   // contexts' global proxy, and turn that into a direct access to the
   // corresponding global object instead.
   if (lookup_start_object_maps.size() == 1) {
-    MapRef lookup_start_object_map(broker(), lookup_start_object_maps[0]);
+    MapRef lookup_start_object_map =
+        MakeRef(broker(), lookup_start_object_maps[0]);
     if (lookup_start_object_map.equals(
             broker()->target_native_context().global_proxy_object().map()) &&
         !broker()->target_native_context().global_object().IsDetached()) {
@@ -1201,7 +1195,7 @@ Reduction JSNativeContextSpecialization::ReduceNamedAccess(
   {
     ZoneVector<PropertyAccessInfo> access_infos_for_feedback(zone());
     for (Handle<Map> map_handle : lookup_start_object_maps) {
-      MapRef map(broker(), map_handle);
+      MapRef map = MakeRef(broker(), map_handle);
       if (map.is_deprecated()) continue;
       PropertyAccessInfo access_info = broker()->GetPropertyAccessInfo(
           map, feedback.name(), access_mode, dependencies(),
@@ -1468,7 +1462,7 @@ Reduction JSNativeContextSpecialization::ReduceJSLoadNamed(Node* node) {
   JSLoadNamedNode n(node);
   NamedAccess const& p = n.Parameters();
   Node* const receiver = n.object();
-  NameRef name(broker(), p.name());
+  NameRef name = MakeRef(broker(), p.name());
 
   // Check if we have a constant receiver.
   HeapObjectMatcher m(receiver);
@@ -1478,10 +1472,7 @@ Reduction JSNativeContextSpecialization::ReduceJSLoadNamed(Node* node) {
         name.equals(ObjectRef(broker(), factory()->prototype_string()))) {
       // Optimize "prototype" property of functions.
       JSFunctionRef function = object.AsJSFunction();
-      if (function.ShouldHaveBeenSerialized() && !function.serialized()) {
-        TRACE_BROKER_MISSING(broker(), "data for function " << function);
-        return NoChange();
-      }
+      if (!function.serialized()) return NoChange();
       // TODO(neis): Remove the has_prototype_slot condition once the broker is
       // always enabled.
       if (!function.map().has_prototype_slot() || !function.has_prototype() ||
@@ -1511,7 +1502,7 @@ Reduction JSNativeContextSpecialization::ReduceJSLoadNamedFromSuper(
     Node* node) {
   JSLoadNamedFromSuperNode n(node);
   NamedAccess const& p = n.Parameters();
-  NameRef name(broker(), p.name());
+  NameRef name = MakeRef(broker(), p.name());
 
   if (!p.feedback().IsValid()) return NoChange();
   return ReducePropertyAccess(node, nullptr, name, jsgraph()->Dead(),
@@ -1594,7 +1585,7 @@ Reduction JSNativeContextSpecialization::ReduceJSGetIterator(Node* node) {
   const Operator* call_op = javascript()->Call(
       JSCallNode::ArityForArgc(0), CallFrequency(), p.callFeedback(),
       ConvertReceiverMode::kNotNullOrUndefined, mode,
-      CallFeedbackRelation::kRelated);
+      CallFeedbackRelation::kTarget);
   Node* call_property =
       graph()->NewNode(call_op, load_property, receiver, n.feedback_vector(),
                        context, frame_state, effect, control);
@@ -1606,7 +1597,7 @@ Reduction JSNativeContextSpecialization::ReduceJSStoreNamed(Node* node) {
   JSStoreNamedNode n(node);
   NamedAccess const& p = n.Parameters();
   if (!p.feedback().IsValid()) return NoChange();
-  return ReducePropertyAccess(node, nullptr, NameRef(broker(), p.name()),
+  return ReducePropertyAccess(node, nullptr, MakeRef(broker(), p.name()),
                               n.value(), FeedbackSource(p.feedback()),
                               AccessMode::kStore);
 }
@@ -1615,7 +1606,7 @@ Reduction JSNativeContextSpecialization::ReduceJSStoreNamedOwn(Node* node) {
   JSStoreNamedOwnNode n(node);
   StoreNamedOwnParameters const& p = n.Parameters();
   if (!p.feedback().IsValid()) return NoChange();
-  return ReducePropertyAccess(node, nullptr, NameRef(broker(), p.name()),
+  return ReducePropertyAccess(node, nullptr, MakeRef(broker(), p.name()),
                               n.value(), FeedbackSource(p.feedback()),
                               AccessMode::kStoreInLiteral);
 }
@@ -1669,7 +1660,7 @@ void JSNativeContextSpecialization::RemoveImpossibleMaps(
     maps->erase(
         std::remove_if(maps->begin(), maps->end(),
                        [root_map, this](Handle<Map> map) {
-                         MapRef map_ref(broker(), map);
+                         MapRef map_ref = MakeRef(broker(), map);
                          return map_ref.is_abandoned_prototype_map() ||
                                 (map_ref.FindRootMap().has_value() &&
                                  !map_ref.FindRootMap()->equals(*root_map));
@@ -1758,7 +1749,7 @@ Reduction JSNativeContextSpecialization::ReduceElementAccess(
     ZoneVector<MapRef> prototype_maps(zone());
     for (ElementAccessInfo const& access_info : access_infos) {
       for (Handle<Map> map : access_info.lookup_start_object_maps()) {
-        MapRef receiver_map(broker(), map);
+        MapRef receiver_map = MakeRef(broker(), map);
         // If the {receiver_map} has a prototype and its elements backing
         // store is either holey, or we have a potentially growing store,
         // then we need to check that all prototypes have stable maps with
@@ -1790,12 +1781,8 @@ Reduction JSNativeContextSpecialization::ReduceElementAccess(
     if (!IsTypedArrayElementsKind(access_info.elements_kind())) continue;
     base::Optional<JSTypedArrayRef> typed_array =
         GetTypedArrayConstant(broker(), receiver);
-    if (typed_array.has_value()) {
-      if (typed_array->ShouldHaveBeenSerialized() &&
-          !typed_array->serialized()) {
-        TRACE_BROKER_MISSING(broker(), "data for typed array " << *typed_array);
-        return NoChange();
-      }
+    if (typed_array.has_value() && !typed_array->serialized()) {
+      return NoChange();
     }
   }
 
@@ -1805,11 +1792,11 @@ Reduction JSNativeContextSpecialization::ReduceElementAccess(
     ElementAccessInfo access_info = access_infos.front();
 
     // Perform possible elements kind transitions.
-    MapRef transition_target(broker(),
-                             access_info.lookup_start_object_maps().front());
+    MapRef transition_target =
+        MakeRef(broker(), access_info.lookup_start_object_maps().front());
     for (auto source : access_info.transition_sources()) {
       DCHECK_EQ(access_info.lookup_start_object_maps().size(), 1);
-      MapRef transition_source(broker(), source);
+      MapRef transition_source = MakeRef(broker(), source);
       effect = graph()->NewNode(
           simplified()->TransitionElementsKind(ElementsTransition(
               IsSimpleMapChangeTransition(transition_source.elements_kind(),
@@ -1857,10 +1844,10 @@ Reduction JSNativeContextSpecialization::ReduceElementAccess(
       Node* this_control = fallthrough_control;
 
       // Perform possible elements kind transitions.
-      MapRef transition_target(broker(),
-                               access_info.lookup_start_object_maps().front());
+      MapRef transition_target =
+          MakeRef(broker(), access_info.lookup_start_object_maps().front());
       for (auto source : access_info.transition_sources()) {
-        MapRef transition_source(broker(), source);
+        MapRef transition_source = MakeRef(broker(), source);
         DCHECK_EQ(access_info.lookup_start_object_maps().size(), 1);
         this_effect = graph()->NewNode(
             simplified()->TransitionElementsKind(ElementsTransition(
@@ -2229,7 +2216,7 @@ Node* JSNativeContextSpecialization::InlinePropertyGetterCall(
     // For fast mode holders we recorded dependencies in BuildPropertyLoad.
     for (const Handle<Map> map : access_info.lookup_start_object_maps()) {
       dependencies()->DependOnConstantInDictionaryPrototypeChain(
-          MapRef{broker(), map}, NameRef{broker(), access_info.name()},
+          MakeRef(broker(), map), MakeRef(broker(), access_info.name()),
           constant, PropertyKind::kAccessor);
     }
   }
@@ -2362,7 +2349,7 @@ JSNativeContextSpecialization::BuildPropertyLoad(
       !access_info.HasDictionaryHolder()) {
     dependencies()->DependOnStablePrototypeChains(
         access_info.lookup_start_object_maps(), kStartAtPrototype,
-        JSObjectRef(broker(), holder));
+        MakeRef(broker(), holder));
   }
 
   // Generate the actual property access.
@@ -2413,7 +2400,7 @@ JSNativeContextSpecialization::BuildPropertyTest(
   if (access_info.holder().ToHandle(&holder)) {
     dependencies()->DependOnStablePrototypeChains(
         access_info.lookup_start_object_maps(), kStartAtPrototype,
-        JSObjectRef(broker(), holder));
+        MakeRef(broker(), holder));
   }
 
   Node* value = access_info.IsNotFound() ? jsgraph()->FalseConstant()
@@ -2457,7 +2444,7 @@ JSNativeContextSpecialization::BuildPropertyStore(
     DCHECK_NE(AccessMode::kStoreInLiteral, access_mode);
     dependencies()->DependOnStablePrototypeChains(
         access_info.lookup_start_object_maps(), kStartAtPrototype,
-        JSObjectRef(broker(), holder));
+        MakeRef(broker(), holder));
   }
 
   DCHECK(!access_info.IsNotFound());
@@ -2508,7 +2495,7 @@ JSNativeContextSpecialization::BuildPropertyStore(
           a.Allocate(HeapNumber::kSize, AllocationType::kYoung,
                      Type::OtherInternal());
           a.Store(AccessBuilder::ForMap(),
-                  MapRef(broker(), factory()->heap_number_map()));
+                  MakeRef(broker(), factory()->heap_number_map()));
           FieldAccess value_field_access = AccessBuilder::ForHeapNumberValue();
           value_field_access.const_field_info = field_access.const_field_info;
           a.Store(value_field_access, value);
@@ -2606,6 +2593,7 @@ JSNativeContextSpecialization::BuildPropertyStore(
       case MachineRepresentation::kWord64:
       case MachineRepresentation::kFloat32:
       case MachineRepresentation::kSimd128:
+      case MachineRepresentation::kMapWord:
         UNREACHABLE();
         break;
     }
@@ -2614,7 +2602,7 @@ JSNativeContextSpecialization::BuildPropertyStore(
     if (access_info.transition_map().ToHandle(&transition_map)) {
       // Check if we need to grow the properties backing store
       // with this transitioning store.
-      MapRef transition_map_ref(broker(), transition_map);
+      MapRef transition_map_ref = MakeRef(broker(), transition_map);
       MapRef original_map = transition_map_ref.GetBackPointer().AsMap();
       if (original_map.UnusedPropertyFields() == 0) {
         DCHECK(!field_index.is_inobject());
@@ -3464,8 +3452,8 @@ bool JSNativeContextSpecialization::CanTreatHoleAsUndefined(
   // or Object.prototype objects as their prototype (in any of the current
   // native contexts, as the global Array protector works isolate-wide).
   for (Handle<Map> map : receiver_maps) {
-    MapRef receiver_map(broker(), map);
-    ObjectRef receiver_prototype = receiver_map.prototype();
+    MapRef receiver_map = MakeRef(broker(), map);
+    ObjectRef receiver_prototype = receiver_map.prototype().value();
     if (!receiver_prototype.IsJSObject() ||
         !broker()->IsArrayOrObjectPrototype(receiver_prototype.AsJSObject())) {
       return false;
@@ -3490,7 +3478,7 @@ bool JSNativeContextSpecialization::InferMaps(
     // For untrusted maps, we can still use the information
     // if the maps are stable.
     for (size_t i = 0; i < map_set.size(); ++i) {
-      MapRef map(broker(), map_set[i]);
+      MapRef map = MakeRef(broker(), map_set[i]);
       if (!map.is_stable()) return false;
     }
     for (size_t i = 0; i < map_set.size(); ++i) {
diff --git a/chromium/v8/src/compiler/js-operator.cc b/chromium/v8/src/compiler/js-operator.cc
index 4f491429f48..18380f4abd0 100644
--- a/chromium/v8/src/compiler/js-operator.cc
+++ b/chromium/v8/src/compiler/js-operator.cc
@@ -8,6 +8,7 @@
 
 #include "src/base/lazy-instance.h"
 #include "src/compiler/js-graph.h"
+#include "src/compiler/js-heap-broker.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/operator.h"
 #include "src/handles/handles-inl.h"
@@ -22,7 +23,7 @@ namespace {
 
 // Returns properties for the given binary op.
 constexpr Operator::Properties BinopProperties(Operator::Opcode opcode) {
-  CONSTEXPR_DCHECK(JSOperator::IsBinaryWithFeedback(opcode));
+  DCHECK(JSOperator::IsBinaryWithFeedback(opcode));
   return opcode == IrOpcode::kJSStrictEqual ? Operator::kPure
                                             : Operator::kNoProperties;
 }
@@ -41,7 +42,7 @@ FeedbackCellRef JSCreateClosureNode::GetFeedbackCellRefChecked(
     JSHeapBroker* broker) const {
   HeapObjectMatcher m(feedback_cell());
   CHECK(m.HasResolvedValue());
-  return FeedbackCellRef(broker, m.ResolvedValue());
+  return MakeRef(broker, Handle<FeedbackCell>::cast(m.ResolvedValue()));
 }
 
 std::ostream& operator<<(std::ostream& os, CallFrequency const& f) {
@@ -338,12 +339,13 @@ bool operator!=(LoadGlobalParameters const& lhs,
 
 
 size_t hash_value(LoadGlobalParameters const& p) {
-  return base::hash_combine(p.name().location(), p.typeof_mode());
+  return base::hash_combine(p.name().location(),
+                            static_cast<int>(p.typeof_mode()));
 }
 
 
 std::ostream& operator<<(std::ostream& os, LoadGlobalParameters const& p) {
-  return os << Brief(*p.name()) << ", " << p.typeof_mode();
+  return os << Brief(*p.name()) << ", " << static_cast<int>(p.typeof_mode());
 }
 
 
diff --git a/chromium/v8/src/compiler/js-operator.h b/chromium/v8/src/compiler/js-operator.h
index 4e447149bc6..8080d4caefe 100644
--- a/chromium/v8/src/compiler/js-operator.h
+++ b/chromium/v8/src/compiler/js-operator.h
@@ -290,9 +290,9 @@ class CallParameters final {
   }
 
   using ArityField = base::BitField<size_t, 0, 27>;
-  using CallFeedbackRelationField = base::BitField<CallFeedbackRelation, 27, 1>;
-  using SpeculationModeField = base::BitField<SpeculationMode, 28, 1>;
-  using ConvertReceiverModeField = base::BitField<ConvertReceiverMode, 29, 2>;
+  using CallFeedbackRelationField = base::BitField<CallFeedbackRelation, 27, 2>;
+  using SpeculationModeField = base::BitField<SpeculationMode, 29, 1>;
+  using ConvertReceiverModeField = base::BitField<ConvertReceiverMode, 30, 2>;
 
   uint32_t const bit_field_;
   CallFrequency const frequency_;
@@ -308,7 +308,7 @@ const CallParameters& CallParametersOf(const Operator* op);
 
 // Defines the arity and the ID for a runtime function call. This is used as a
 // parameter by JSCallRuntime operators.
-class CallRuntimeParameters final {
+class V8_EXPORT_PRIVATE CallRuntimeParameters final {
  public:
   CallRuntimeParameters(Runtime::FunctionId id, size_t arity)
       : id_(id), arity_(arity) {}
@@ -328,8 +328,8 @@ size_t hash_value(CallRuntimeParameters const&);
 
 std::ostream& operator<<(std::ostream&, CallRuntimeParameters const&);
 
-const CallRuntimeParameters& CallRuntimeParametersOf(const Operator* op);
-
+V8_EXPORT_PRIVATE const CallRuntimeParameters& CallRuntimeParametersOf(
+    const Operator* op);
 
 // Defines the location of a context slot relative to a specific scope. This is
 // used as a parameter by JSLoadContext and JSStoreContext operators and allows
@@ -951,12 +951,12 @@ class V8_EXPORT_PRIVATE JSOperatorBuilder final
       CallFrequency const& frequency,
       const FeedbackSource& feedback = FeedbackSource{},
       SpeculationMode speculation_mode = SpeculationMode::kDisallowSpeculation,
-      CallFeedbackRelation feedback_relation = CallFeedbackRelation::kRelated);
+      CallFeedbackRelation feedback_relation = CallFeedbackRelation::kTarget);
   const Operator* CallWithSpread(
       uint32_t arity, CallFrequency const& frequency = CallFrequency(),
       FeedbackSource const& feedback = FeedbackSource(),
       SpeculationMode speculation_mode = SpeculationMode::kDisallowSpeculation,
-      CallFeedbackRelation feedback_relation = CallFeedbackRelation::kRelated);
+      CallFeedbackRelation feedback_relation = CallFeedbackRelation::kTarget);
   const Operator* CallRuntime(Runtime::FunctionId id);
   const Operator* CallRuntime(Runtime::FunctionId id, size_t arity);
   const Operator* CallRuntime(const Runtime::Function* function, size_t arity);
@@ -1002,7 +1002,7 @@ class V8_EXPORT_PRIVATE JSOperatorBuilder final
 
   const Operator* LoadGlobal(const Handle<Name>& name,
                              const FeedbackSource& feedback,
-                             TypeofMode typeof_mode = NOT_INSIDE_TYPEOF);
+                             TypeofMode typeof_mode = TypeofMode::kNotInside);
   const Operator* StoreGlobal(LanguageMode language_mode,
                               const Handle<Name>& name,
                               const FeedbackSource& feedback);
@@ -1112,7 +1112,7 @@ class JSNodeWrapperBase : public NodeWrapper {
 class JSUnaryOpNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSUnaryOpNode(Node* node) : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(JSOperator::IsUnaryWithFeedback(node->opcode()));
+    DCHECK(JSOperator::IsUnaryWithFeedback(node->opcode()));
   }
 
 #define INPUTS(V)            \
@@ -1129,7 +1129,7 @@ JS_UNOP_WITH_FEEDBACK(V)
 class JSBinaryOpNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSBinaryOpNode(Node* node) : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(JSOperator::IsBinaryWithFeedback(node->opcode()));
+    DCHECK(JSOperator::IsBinaryWithFeedback(node->opcode()));
   }
 
   const FeedbackParameter& Parameters() const {
@@ -1151,7 +1151,7 @@ JS_BINOP_WITH_FEEDBACK(V)
 class JSGetIteratorNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSGetIteratorNode(Node* node) : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSGetIterator);
+    DCHECK_EQ(IrOpcode::kJSGetIterator, node->opcode());
   }
 
   const GetIteratorParameters& Parameters() const {
@@ -1168,7 +1168,7 @@ class JSGetIteratorNode final : public JSNodeWrapperBase {
 class JSCloneObjectNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSCloneObjectNode(Node* node) : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSCloneObject);
+    DCHECK_EQ(IrOpcode::kJSCloneObject, node->opcode());
   }
 
   const CloneObjectParameters& Parameters() const {
@@ -1186,7 +1186,7 @@ class JSGetTemplateObjectNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSGetTemplateObjectNode(Node* node)
       : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSGetTemplateObject);
+    DCHECK_EQ(IrOpcode::kJSGetTemplateObject, node->opcode());
   }
 
   const GetTemplateObjectParameters& Parameters() const {
@@ -1202,9 +1202,9 @@ class JSCreateLiteralOpNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSCreateLiteralOpNode(Node* node)
       : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSCreateLiteralArray ||
-                     node->opcode() == IrOpcode::kJSCreateLiteralObject ||
-                     node->opcode() == IrOpcode::kJSCreateLiteralRegExp);
+    DCHECK(node->opcode() == IrOpcode::kJSCreateLiteralArray ||
+           node->opcode() == IrOpcode::kJSCreateLiteralObject ||
+           node->opcode() == IrOpcode::kJSCreateLiteralRegExp);
   }
 
   const CreateLiteralParameters& Parameters() const {
@@ -1223,7 +1223,7 @@ using JSCreateLiteralRegExpNode = JSCreateLiteralOpNode;
 class JSHasPropertyNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSHasPropertyNode(Node* node) : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSHasProperty);
+    DCHECK_EQ(IrOpcode::kJSHasProperty, node->opcode());
   }
 
   const PropertyAccess& Parameters() const {
@@ -1241,7 +1241,7 @@ class JSHasPropertyNode final : public JSNodeWrapperBase {
 class JSLoadPropertyNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSLoadPropertyNode(Node* node) : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSLoadProperty);
+    DCHECK_EQ(IrOpcode::kJSLoadProperty, node->opcode());
   }
 
   const PropertyAccess& Parameters() const {
@@ -1259,7 +1259,7 @@ class JSLoadPropertyNode final : public JSNodeWrapperBase {
 class JSStorePropertyNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSStorePropertyNode(Node* node) : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSStoreProperty);
+    DCHECK_EQ(IrOpcode::kJSStoreProperty, node->opcode());
   }
 
   const PropertyAccess& Parameters() const {
@@ -1284,14 +1284,14 @@ class JSCallOrConstructNode : public JSNodeWrapperBase {
  public:
   explicit constexpr JSCallOrConstructNode(Node* node)
       : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSCall ||
-                     node->opcode() == IrOpcode::kJSCallWithArrayLike ||
-                     node->opcode() == IrOpcode::kJSCallWithSpread ||
-                     node->opcode() == IrOpcode::kJSConstruct ||
-                     node->opcode() == IrOpcode::kJSConstructWithArrayLike ||
-                     node->opcode() == IrOpcode::kJSConstructWithSpread
+    DCHECK(node->opcode() == IrOpcode::kJSCall ||
+           node->opcode() == IrOpcode::kJSCallWithArrayLike ||
+           node->opcode() == IrOpcode::kJSCallWithSpread ||
+           node->opcode() == IrOpcode::kJSConstruct ||
+           node->opcode() == IrOpcode::kJSConstructWithArrayLike ||
+           node->opcode() == IrOpcode::kJSConstructWithSpread
 #if V8_ENABLE_WEBASSEMBLY
-                     || node->opcode() == IrOpcode::kJSWasmCall
+           || node->opcode() == IrOpcode::kJSWasmCall
 #endif  // V8_ENABLE_WEBASSEMBLY
     );  // NOLINT(whitespace/parens)
   }
@@ -1373,7 +1373,7 @@ template <int kOpcode>
 class JSCallNodeBase final : public JSCallOrConstructNode {
  public:
   explicit constexpr JSCallNodeBase(Node* node) : JSCallOrConstructNode(node) {
-    CONSTEXPR_DCHECK(node->opcode() == kOpcode);
+    DCHECK_EQ(kOpcode, node->opcode());
   }
 
   const CallParameters& Parameters() const {
@@ -1405,7 +1405,7 @@ using JSCallWithArrayLikeNode = JSCallNodeBase<IrOpcode::kJSCallWithArrayLike>;
 class JSWasmCallNode final : public JSCallOrConstructNode {
  public:
   explicit constexpr JSWasmCallNode(Node* node) : JSCallOrConstructNode(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSWasmCall);
+    DCHECK_EQ(IrOpcode::kJSWasmCall, node->opcode());
   }
 
   const JSWasmCallParameters& Parameters() const {
@@ -1437,7 +1437,7 @@ class JSConstructNodeBase final : public JSCallOrConstructNode {
  public:
   explicit constexpr JSConstructNodeBase(Node* node)
       : JSCallOrConstructNode(node) {
-    CONSTEXPR_DCHECK(node->opcode() == kOpcode);
+    DCHECK_EQ(kOpcode, node->opcode());
   }
 
   const ConstructParameters& Parameters() const {
@@ -1470,7 +1470,7 @@ using JSConstructWithArrayLikeNode =
 class JSLoadNamedNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSLoadNamedNode(Node* node) : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSLoadNamed);
+    DCHECK_EQ(IrOpcode::kJSLoadNamed, node->opcode());
   }
 
   const NamedAccess& Parameters() const { return NamedAccessOf(node()->op()); }
@@ -1486,7 +1486,7 @@ class JSLoadNamedFromSuperNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSLoadNamedFromSuperNode(Node* node)
       : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSLoadNamedFromSuper);
+    DCHECK_EQ(IrOpcode::kJSLoadNamedFromSuper, node->opcode());
   }
 
   const NamedAccess& Parameters() const { return NamedAccessOf(node()->op()); }
@@ -1502,7 +1502,7 @@ class JSLoadNamedFromSuperNode final : public JSNodeWrapperBase {
 class JSStoreNamedNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSStoreNamedNode(Node* node) : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSStoreNamed);
+    DCHECK_EQ(IrOpcode::kJSStoreNamed, node->opcode());
   }
 
   const NamedAccess& Parameters() const { return NamedAccessOf(node()->op()); }
@@ -1518,7 +1518,7 @@ class JSStoreNamedNode final : public JSNodeWrapperBase {
 class JSStoreNamedOwnNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSStoreNamedOwnNode(Node* node) : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSStoreNamedOwn);
+    DCHECK_EQ(IrOpcode::kJSStoreNamedOwn, node->opcode());
   }
 
   const StoreNamedOwnParameters& Parameters() const {
@@ -1536,7 +1536,7 @@ class JSStoreNamedOwnNode final : public JSNodeWrapperBase {
 class JSStoreGlobalNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSStoreGlobalNode(Node* node) : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSStoreGlobal);
+    DCHECK_EQ(IrOpcode::kJSStoreGlobal, node->opcode());
   }
 
   const StoreGlobalParameters& Parameters() const {
@@ -1553,7 +1553,7 @@ class JSStoreGlobalNode final : public JSNodeWrapperBase {
 class JSLoadGlobalNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSLoadGlobalNode(Node* node) : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSLoadGlobal);
+    DCHECK_EQ(IrOpcode::kJSLoadGlobal, node->opcode());
   }
 
   const LoadGlobalParameters& Parameters() const {
@@ -1569,7 +1569,7 @@ class JSCreateEmptyLiteralArrayNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSCreateEmptyLiteralArrayNode(Node* node)
       : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSCreateEmptyLiteralArray);
+    DCHECK_EQ(IrOpcode::kJSCreateEmptyLiteralArray, node->opcode());
   }
 
   const FeedbackParameter& Parameters() const {
@@ -1585,7 +1585,7 @@ class JSStoreDataPropertyInLiteralNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSStoreDataPropertyInLiteralNode(Node* node)
       : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSStoreDataPropertyInLiteral);
+    DCHECK_EQ(IrOpcode::kJSStoreDataPropertyInLiteral, node->opcode());
   }
 
   const FeedbackParameter& Parameters() const {
@@ -1606,7 +1606,7 @@ class JSStoreInArrayLiteralNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSStoreInArrayLiteralNode(Node* node)
       : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSStoreInArrayLiteral);
+    DCHECK_EQ(IrOpcode::kJSStoreInArrayLiteral, node->opcode());
   }
 
   const FeedbackParameter& Parameters() const {
@@ -1625,7 +1625,7 @@ class JSStoreInArrayLiteralNode final : public JSNodeWrapperBase {
 class JSCreateClosureNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSCreateClosureNode(Node* node) : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSCreateClosure);
+    DCHECK_EQ(IrOpcode::kJSCreateClosure, node->opcode());
   }
 
   const CreateClosureParameters& Parameters() const {
@@ -1642,7 +1642,7 @@ class JSCreateClosureNode final : public JSNodeWrapperBase {
 class JSForInPrepareNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSForInPrepareNode(Node* node) : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSForInPrepare);
+    DCHECK_EQ(IrOpcode::kJSForInPrepare, node->opcode());
   }
 
   const ForInParameters& Parameters() const {
@@ -1659,7 +1659,7 @@ class JSForInPrepareNode final : public JSNodeWrapperBase {
 class JSForInNextNode final : public JSNodeWrapperBase {
  public:
   explicit constexpr JSForInNextNode(Node* node) : JSNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kJSForInNext);
+    DCHECK_EQ(IrOpcode::kJSForInNext, node->opcode());
   }
 
   const ForInParameters& Parameters() const {
diff --git a/chromium/v8/src/compiler/js-typed-lowering.cc b/chromium/v8/src/compiler/js-typed-lowering.cc
index 008aacdb392..ebd839acabd 100644
--- a/chromium/v8/src/compiler/js-typed-lowering.cc
+++ b/chromium/v8/src/compiler/js-typed-lowering.cc
@@ -7,6 +7,7 @@
 #include "src/ast/modules.h"
 #include "src/builtins/builtins-utils.h"
 #include "src/codegen/code-factory.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/allocation-builder.h"
 #include "src/compiler/graph-assembler.h"
@@ -592,8 +593,8 @@ Reduction JSTypedLowering::ReduceJSAdd(Node* node) {
     Node* length =
         graph()->NewNode(simplified()->NumberAdd(), left_length, right_length);
 
-    PropertyCellRef string_length_protector(
-        broker(), factory()->string_length_protector());
+    PropertyCellRef string_length_protector =
+        MakeRef(broker(), factory()->string_length_protector());
     string_length_protector.SerializeAsProtector();
 
     if (string_length_protector.value().AsSmi() ==
@@ -1171,8 +1172,8 @@ Reduction JSTypedLowering::ReduceJSLoadNamed(Node* node) {
   JSLoadNamedNode n(node);
   Node* receiver = n.object();
   Type receiver_type = NodeProperties::GetType(receiver);
-  NameRef name(broker(), NamedAccessOf(node->op()).name());
-  NameRef length_str(broker(), factory()->length_string());
+  NameRef name = MakeRef(broker(), NamedAccessOf(node->op()).name());
+  NameRef length_str = MakeRef(broker(), factory()->length_string());
   // Optimize "length" property of strings.
   if (name.equals(length_str) && receiver_type.Is(Type::String())) {
     Node* value = graph()->NewNode(simplified()->StringLength(), receiver);
@@ -1541,8 +1542,8 @@ void ReduceBuiltin(JSGraph* jsgraph, Node* node, int builtin_index, int arity,
   DCHECK(Builtins::IsCpp(builtin_index));
   const bool has_builtin_exit_frame = true;
 
-  Node* stub = jsgraph->CEntryStubConstant(1, kDontSaveFPRegs, kArgvOnStack,
-                                           has_builtin_exit_frame);
+  Node* stub = jsgraph->CEntryStubConstant(
+      1, SaveFPRegsMode::kIgnore, ArgvMode::kStack, has_builtin_exit_frame);
   node->ReplaceInput(0, stub);
 
   const int argc = arity + BuiltinArguments::kNumExtraArgsWithReceiver;
@@ -1628,10 +1629,10 @@ Reduction JSTypedLowering::ReduceJSConstruct(Node* node) {
 
     // Patch {node} to an indirect call via the {function}s construct stub.
     bool use_builtin_construct_stub = function.shared().construct_as_builtin();
-    CodeRef code(broker(),
-                 use_builtin_construct_stub
-                     ? BUILTIN_CODE(isolate(), JSBuiltinsConstructStub)
-                     : BUILTIN_CODE(isolate(), JSConstructStubGeneric));
+    CodeRef code = MakeRef(
+        broker(), use_builtin_construct_stub
+                      ? BUILTIN_CODE(isolate(), JSBuiltinsConstructStub)
+                      : BUILTIN_CODE(isolate(), JSConstructStubGeneric));
     STATIC_ASSERT(JSConstructNode::TargetIndex() == 0);
     STATIC_ASSERT(JSConstructNode::NewTargetIndex() == 1);
     node->RemoveInput(n.FeedbackVectorIndex());
@@ -1712,9 +1713,9 @@ Reduction JSTypedLowering::ReduceJSCall(Node* node) {
   } else if (target->opcode() == IrOpcode::kJSCreateClosure) {
     CreateClosureParameters const& ccp =
         JSCreateClosureNode{target}.Parameters();
-    shared = SharedFunctionInfoRef(broker(), ccp.shared_info());
+    shared = MakeRef(broker(), ccp.shared_info());
   } else if (target->opcode() == IrOpcode::kCheckClosure) {
-    FeedbackCellRef cell(broker(), FeedbackCellOf(target->op()));
+    FeedbackCellRef cell = MakeRef(broker(), FeedbackCellOf(target->op()));
     base::Optional<FeedbackVectorRef> feedback_vector = cell.value();
     if (feedback_vector.has_value()) {
       shared = feedback_vector->shared_function_info();
@@ -1723,6 +1724,9 @@ Reduction JSTypedLowering::ReduceJSCall(Node* node) {
 
   if (shared.has_value()) {
     // Do not inline the call if we need to check whether to break at entry.
+    // If this state changes during background compilation, the compilation
+    // job will be aborted from the main thread (see
+    // Debug::PrepareFunctionForDebugExecution()).
     if (shared->HasBreakInfo()) return NoChange();
 
     // Class constructors are callable, but [[Call]] will raise an exception.
diff --git a/chromium/v8/src/compiler/load-elimination.cc b/chromium/v8/src/compiler/load-elimination.cc
index 2a0189ae125..377654e4215 100644
--- a/chromium/v8/src/compiler/load-elimination.cc
+++ b/chromium/v8/src/compiler/load-elimination.cc
@@ -1076,6 +1076,7 @@ Reduction LoadElimination::ReduceLoadElement(Node* node) {
     case MachineRepresentation::kTaggedSigned:
     case MachineRepresentation::kTaggedPointer:
     case MachineRepresentation::kTagged:
+    case MachineRepresentation::kMapWord:
       if (Node* replacement = state->LookupElement(
               object, index, access.machine_type.representation())) {
         // Make sure we don't resurrect dead {replacement} nodes.
@@ -1131,6 +1132,7 @@ Reduction LoadElimination::ReduceStoreElement(Node* node) {
     case MachineRepresentation::kTaggedSigned:
     case MachineRepresentation::kTaggedPointer:
     case MachineRepresentation::kTagged:
+    case MachineRepresentation::kMapWord:
       state = state->AddElement(object, index, new_value,
                                 access.machine_type.representation(), zone());
       break;
@@ -1424,6 +1426,7 @@ LoadElimination::IndexRange LoadElimination::FieldIndexOf(
     case MachineRepresentation::kTaggedSigned:
     case MachineRepresentation::kTaggedPointer:
     case MachineRepresentation::kTagged:
+    case MachineRepresentation::kMapWord:
     case MachineRepresentation::kCompressedPointer:
     case MachineRepresentation::kCompressed:
       break;
diff --git a/chromium/v8/src/compiler/loop-analysis.cc b/chromium/v8/src/compiler/loop-analysis.cc
index 0d52e780049..ee56a665db7 100644
--- a/chromium/v8/src/compiler/loop-analysis.cc
+++ b/chromium/v8/src/compiler/loop-analysis.cc
@@ -547,7 +547,6 @@ LoopTree* LoopFinder::BuildLoopTree(Graph* graph, TickCounter* tick_counter,
 ZoneUnorderedSet<Node*>* LoopFinder::FindUnnestedLoopFromHeader(
     Node* loop_header, Zone* zone, size_t max_size) {
   auto* visited = zone->New<ZoneUnorderedSet<Node*>>(zone);
-
   std::vector<Node*> queue;
 
   DCHECK(loop_header->opcode() == IrOpcode::kLoop);
@@ -589,6 +588,30 @@ ZoneUnorderedSet<Node*>* LoopFinder::FindUnnestedLoopFromHeader(
     }
   }
 
+  // Check that there is no floating control other than direct nodes to start().
+  // We do this by checking that all non-start control inputs of loop nodes are
+  // also in the loop.
+  // TODO(manoskouk): This is a safety check. Consider making it DEBUG-only when
+  // we are confident there is no incompatible floating control generated in
+  // wasm.
+  for (Node* node : *visited) {
+    // The loop header is allowed to point outside the loop.
+    if (node == loop_header) continue;
+
+    for (Edge edge : node->input_edges()) {
+      Node* input = edge.to();
+      if (NodeProperties::IsControlEdge(edge) && visited->count(input) == 0 &&
+          input->opcode() != IrOpcode::kStart) {
+        FATAL(
+            "Floating control detected in wasm turbofan graph: Node #%d:%s is "
+            "inside loop headed by #%d, but its control dependency #%d:%s is "
+            "outside",
+            node->id(), node->op()->mnemonic(), loop_header->id(), input->id(),
+            input->op()->mnemonic());
+      }
+    }
+  }
+
   return visited;
 }
 
diff --git a/chromium/v8/src/compiler/machine-graph-verifier.cc b/chromium/v8/src/compiler/machine-graph-verifier.cc
index cabf23f4d55..3aee3a8d35c 100644
--- a/chromium/v8/src/compiler/machine-graph-verifier.cc
+++ b/chromium/v8/src/compiler/machine-graph-verifier.cc
@@ -999,6 +999,7 @@ class MachineRepresentationChecker {
         return IsAnyTagged(actual);
       case MachineRepresentation::kCompressed:
         return IsAnyCompressed(actual);
+      case MachineRepresentation::kMapWord:
       case MachineRepresentation::kTaggedSigned:
       case MachineRepresentation::kTaggedPointer:
         // TODO(turbofan): At the moment, the machine graph doesn't contain
diff --git a/chromium/v8/src/compiler/machine-operator-reducer.cc b/chromium/v8/src/compiler/machine-operator-reducer.cc
index 5d61dfac6ab..3e2bacf90a6 100644
--- a/chromium/v8/src/compiler/machine-operator-reducer.cc
+++ b/chromium/v8/src/compiler/machine-operator-reducer.cc
@@ -1718,11 +1718,21 @@ Reduction MachineOperatorReducer::ReduceWordNAnd(Node* node) {
 namespace {
 
 // Represents an operation of the form `(source & mask) == masked_value`.
+// where each bit set in masked_value also has to be set in mask.
 struct BitfieldCheck {
-  Node* source;
-  uint32_t mask;
-  uint32_t masked_value;
-  bool truncate_from_64_bit;
+  Node* const source;
+  uint32_t const mask;
+  uint32_t const masked_value;
+  bool const truncate_from_64_bit;
+
+  BitfieldCheck(Node* source, uint32_t mask, uint32_t masked_value,
+                bool truncate_from_64_bit)
+      : source(source),
+        mask(mask),
+        masked_value(masked_value),
+        truncate_from_64_bit(truncate_from_64_bit) {
+    CHECK_EQ(masked_value & ~mask, 0);
+  }
 
   static base::Optional<BitfieldCheck> Detect(Node* node) {
     // There are two patterns to check for here:
@@ -1737,14 +1747,16 @@ struct BitfieldCheck {
       if (eq.left().IsWord32And()) {
         Uint32BinopMatcher mand(eq.left().node());
         if (mand.right().HasResolvedValue() && eq.right().HasResolvedValue()) {
-          BitfieldCheck result{mand.left().node(), mand.right().ResolvedValue(),
-                               eq.right().ResolvedValue(), false};
+          uint32_t mask = mand.right().ResolvedValue();
+          uint32_t masked_value = eq.right().ResolvedValue();
+          if ((masked_value & ~mask) != 0) return {};
           if (mand.left().IsTruncateInt64ToInt32()) {
-            result.truncate_from_64_bit = true;
-            result.source =
-                NodeProperties::GetValueInput(mand.left().node(), 0);
+            return BitfieldCheck(
+                NodeProperties::GetValueInput(mand.left().node(), 0), mask,
+                masked_value, true);
+          } else {
+            return BitfieldCheck(mand.left().node(), mask, masked_value, false);
           }
-          return result;
         }
       }
     } else {
@@ -1836,17 +1848,20 @@ Reduction MachineOperatorReducer::ReduceWord64And(Node* node) {
 }
 
 Reduction MachineOperatorReducer::TryMatchWord32Ror(Node* node) {
+  // Recognize rotation, we are matching and transforming as follows:
+  //   x << y         |  x >>> (32 - y)    =>  x ror (32 - y)
+  //   x << (32 - y)  |  x >>> y           =>  x ror y
+  //   x << y         ^  x >>> (32 - y)    =>  x ror (32 - y)   if y & 31 != 0
+  //   x << (32 - y)  ^  x >>> y           =>  x ror y          if y & 31 != 0
+  // (As well as the commuted forms.)
+  // Note the side condition for XOR: the optimization doesn't hold for
+  // multiples of 32.
+
   DCHECK(IrOpcode::kWord32Or == node->opcode() ||
          IrOpcode::kWord32Xor == node->opcode());
   Int32BinopMatcher m(node);
   Node* shl = nullptr;
   Node* shr = nullptr;
-  // Recognize rotation, we are matching:
-  //  * x << y | x >>> (32 - y) => x ror (32 - y), i.e  x rol y
-  //  * x << (32 - y) | x >>> y => x ror y
-  //  * x << y ^ x >>> (32 - y) => x ror (32 - y), i.e. x rol y
-  //  * x << (32 - y) ^ x >>> y => x ror y
-  // as well as their commuted form.
   if (m.left().IsWord32Shl() && m.right().IsWord32Shr()) {
     shl = m.left().node();
     shr = m.right().node();
@@ -1863,8 +1878,13 @@ Reduction MachineOperatorReducer::TryMatchWord32Ror(Node* node) {
 
   if (mshl.right().HasResolvedValue() && mshr.right().HasResolvedValue()) {
     // Case where y is a constant.
-    if (mshl.right().ResolvedValue() + mshr.right().ResolvedValue() != 32)
+    if (mshl.right().ResolvedValue() + mshr.right().ResolvedValue() != 32) {
       return NoChange();
+    }
+    if (node->opcode() == IrOpcode::kWord32Xor &&
+        (mshl.right().ResolvedValue() & 31) == 0) {
+      return NoChange();
+    }
   } else {
     Node* sub = nullptr;
     Node* y = nullptr;
@@ -1880,6 +1900,9 @@ Reduction MachineOperatorReducer::TryMatchWord32Ror(Node* node) {
 
     Int32BinopMatcher msub(sub);
     if (!msub.left().Is(32) || msub.right().node() != y) return NoChange();
+    if (node->opcode() == IrOpcode::kWord32Xor) {
+      return NoChange();  // Can't guarantee y & 31 != 0.
+    }
   }
 
   node->ReplaceInput(0, mshl.left().node());
diff --git a/chromium/v8/src/compiler/machine-operator.cc b/chromium/v8/src/compiler/machine-operator.cc
index 1a897a32032..3d61d70b022 100644
--- a/chromium/v8/src/compiler/machine-operator.cc
+++ b/chromium/v8/src/compiler/machine-operator.cc
@@ -252,6 +252,7 @@ std::ostream& operator<<(std::ostream& os, TruncateKind kind) {
   V(Word64Shl, Operator::kNoProperties, 2, 0, 1)                         \
   V(Word64Shr, Operator::kNoProperties, 2, 0, 1)                         \
   V(Word64Ror, Operator::kNoProperties, 2, 0, 1)                         \
+  V(Word64RorLowerable, Operator::kNoProperties, 2, 1, 1)                \
   V(Word64Equal, Operator::kCommutative, 2, 0, 1)                        \
   V(Int64Add, Operator::kAssociative | Operator::kCommutative, 2, 0, 1)  \
   V(Int64Sub, Operator::kNoProperties, 2, 0, 1)                          \
@@ -272,6 +273,7 @@ std::ostream& operator<<(std::ostream& os, TruncateKind kind) {
   PURE_BINARY_OP_LIST_64(V)                                                \
   V(Word32Clz, Operator::kNoProperties, 1, 0, 1)                           \
   V(Word64Clz, Operator::kNoProperties, 1, 0, 1)                           \
+  V(Word64ClzLowerable, Operator::kNoProperties, 1, 1, 1)                  \
   V(Word32ReverseBytes, Operator::kNoProperties, 1, 0, 1)                  \
   V(Word64ReverseBytes, Operator::kNoProperties, 1, 0, 1)                  \
   V(Simd128ReverseBytes, Operator::kNoProperties, 1, 0, 1)                 \
@@ -566,8 +568,10 @@ std::ostream& operator<<(std::ostream& os, TruncateKind kind) {
 #define PURE_OPTIONAL_OP_LIST(V)                            \
   V(Word32Ctz, Operator::kNoProperties, 1, 0, 1)            \
   V(Word64Ctz, Operator::kNoProperties, 1, 0, 1)            \
+  V(Word64CtzLowerable, Operator::kNoProperties, 1, 1, 1)   \
   V(Word32Rol, Operator::kNoProperties, 2, 0, 1)            \
   V(Word64Rol, Operator::kNoProperties, 2, 0, 1)            \
+  V(Word64RolLowerable, Operator::kNoProperties, 2, 1, 1)   \
   V(Word32ReverseBits, Operator::kNoProperties, 1, 0, 1)    \
   V(Word64ReverseBits, Operator::kNoProperties, 1, 0, 1)    \
   V(Int32AbsWithOverflow, Operator::kNoProperties, 1, 0, 2) \
@@ -583,6 +587,8 @@ std::ostream& operator<<(std::ostream& os, TruncateKind kind) {
   V(Float64RoundTiesAway, Operator::kNoProperties, 1, 0, 1) \
   V(Float32RoundTiesEven, Operator::kNoProperties, 1, 0, 1) \
   V(Float64RoundTiesEven, Operator::kNoProperties, 1, 0, 1) \
+  V(Word32Select, Operator::kNoProperties, 3, 0, 1)         \
+  V(Word64Select, Operator::kNoProperties, 3, 0, 1)         \
   V(Float32Select, Operator::kNoProperties, 3, 0, 1)        \
   V(Float64Select, Operator::kNoProperties, 3, 0, 1)
 
@@ -610,6 +616,7 @@ std::ostream& operator<<(std::ostream& os, TruncateKind kind) {
   V(Pointer)                 \
   V(TaggedSigned)            \
   V(TaggedPointer)           \
+  V(MapInHeader)             \
   V(AnyTagged)               \
   V(CompressedPointer)       \
   V(AnyCompressed)
@@ -622,6 +629,7 @@ std::ostream& operator<<(std::ostream& os, TruncateKind kind) {
   V(kWord16)                           \
   V(kWord32)                           \
   V(kWord64)                           \
+  V(kMapWord)                          \
   V(kTaggedSigned)                     \
   V(kTaggedPointer)                    \
   V(kTagged)                           \
@@ -1332,6 +1340,7 @@ OVERFLOW_OP_LIST(OVERFLOW_OP)
 #undef OVERFLOW_OP
 
 const Operator* MachineOperatorBuilder::Load(LoadRepresentation rep) {
+  DCHECK(!rep.IsMapWord());
 #define LOAD(Type)                  \
   if (rep == MachineType::Type()) { \
     return &cache_.kLoad##Type;     \
@@ -1491,6 +1500,7 @@ const Operator* MachineOperatorBuilder::StackSlot(MachineRepresentation rep,
 }
 
 const Operator* MachineOperatorBuilder::Store(StoreRepresentation store_rep) {
+  DCHECK_NE(store_rep.representation(), MachineRepresentation::kMapWord);
   switch (store_rep.representation()) {
 #define STORE(kRep)                                              \
   case MachineRepresentation::kRep:                              \
diff --git a/chromium/v8/src/compiler/machine-operator.h b/chromium/v8/src/compiler/machine-operator.h
index 87a2eb891f1..0ee3649ad0c 100644
--- a/chromium/v8/src/compiler/machine-operator.h
+++ b/chromium/v8/src/compiler/machine-operator.h
@@ -104,7 +104,8 @@ V8_EXPORT_PRIVATE LoadLaneParameters const& LoadLaneParametersOf(
     Operator const*) V8_WARN_UNUSED_RESULT;
 
 // A Store needs a MachineType and a WriteBarrierKind in order to emit the
-// correct write barrier.
+// correct write barrier, and needs to state whether it is storing into the
+// header word, so that the value can be packed, if necessary.
 class StoreRepresentation final {
  public:
   StoreRepresentation(MachineRepresentation representation,
@@ -248,25 +249,30 @@ class V8_EXPORT_PRIVATE MachineOperatorBuilder final
     kWord32ShiftIsSafe = 1u << 11,
     kWord32Ctz = 1u << 12,
     kWord64Ctz = 1u << 13,
-    kWord32Popcnt = 1u << 14,
-    kWord64Popcnt = 1u << 15,
-    kWord32ReverseBits = 1u << 16,
-    kWord64ReverseBits = 1u << 17,
-    kFloat32Select = 1u << 18,
-    kFloat64Select = 1u << 19,
-    kInt32AbsWithOverflow = 1u << 20,
-    kInt64AbsWithOverflow = 1u << 21,
-    kWord32Rol = 1u << 22,
-    kWord64Rol = 1u << 23,
-    kSatConversionIsSafe = 1u << 24,
+    kWord64CtzLowerable = 1u << 14,
+    kWord32Popcnt = 1u << 15,
+    kWord64Popcnt = 1u << 16,
+    kWord32ReverseBits = 1u << 17,
+    kWord64ReverseBits = 1u << 18,
+    kFloat32Select = 1u << 19,
+    kFloat64Select = 1u << 20,
+    kInt32AbsWithOverflow = 1u << 21,
+    kInt64AbsWithOverflow = 1u << 22,
+    kWord32Rol = 1u << 23,
+    kWord64Rol = 1u << 24,
+    kWord64RolLowerable = 1u << 25,
+    kSatConversionIsSafe = 1u << 26,
+    kWord32Select = 1u << 27,
+    kWord64Select = 1u << 28,
     kAllOptionalOps =
         kFloat32RoundDown | kFloat64RoundDown | kFloat32RoundUp |
         kFloat64RoundUp | kFloat32RoundTruncate | kFloat64RoundTruncate |
         kFloat64RoundTiesAway | kFloat32RoundTiesEven | kFloat64RoundTiesEven |
-        kWord32Ctz | kWord64Ctz | kWord32Popcnt | kWord64Popcnt |
-        kWord32ReverseBits | kWord64ReverseBits | kInt32AbsWithOverflow |
-        kInt64AbsWithOverflow | kWord32Rol | kWord64Rol | kSatConversionIsSafe |
-        kFloat32Select | kFloat64Select
+        kWord32Ctz | kWord64Ctz | kWord64CtzLowerable | kWord32Popcnt |
+        kWord64Popcnt | kWord32ReverseBits | kWord64ReverseBits |
+        kInt32AbsWithOverflow | kInt64AbsWithOverflow | kWord32Rol |
+        kWord64Rol | kWord64RolLowerable | kSatConversionIsSafe |
+        kFloat32Select | kFloat64Select | kWord32Select | kWord64Select
   };
   using Flags = base::Flags<Flag, unsigned>;
 
@@ -386,10 +392,21 @@ class V8_EXPORT_PRIVATE MachineOperatorBuilder final
   const Operator* Word64SarShiftOutZeros() {
     return Word64Sar(ShiftKind::kShiftOutZeros);
   }
+
+  // 64-bit rol, ror, clz and ctz operators have two versions: the non-suffixed
+  // ones are meant to be used in 64-bit systems and have no control input. The
+  // "Lowerable"-suffixed ones are meant to be temporary operators in 32-bit
+  // systems and will be lowered to 32-bit operators. They have a control input
+  // to enable the lowering.
   const OptionalOperator Word64Rol();
   const Operator* Word64Ror();
   const Operator* Word64Clz();
   const OptionalOperator Word64Ctz();
+  const OptionalOperator Word64RolLowerable();
+  const Operator* Word64RorLowerable();
+  const Operator* Word64ClzLowerable();
+  const OptionalOperator Word64CtzLowerable();
+
   const Operator* Word64Equal();
 
   const Operator* Int32PairAdd();
@@ -562,7 +579,11 @@ class V8_EXPORT_PRIVATE MachineOperatorBuilder final
   const OptionalOperator Float32RoundTiesEven();
   const OptionalOperator Float64RoundTiesEven();
 
-  // Floating point conditional selects.
+  // Conditional selects. Input 1 is the condition, Input 2 is the result value
+  // if the condition is {true}, Input 3 is the result value if the condition is
+  // false.
+  const OptionalOperator Word32Select();
+  const OptionalOperator Word64Select();
   const OptionalOperator Float32Select();
   const OptionalOperator Float64Select();
 
diff --git a/chromium/v8/src/compiler/map-inference.cc b/chromium/v8/src/compiler/map-inference.cc
index 1e1a59d7843..b6c96163c68 100644
--- a/chromium/v8/src/compiler/map-inference.cc
+++ b/chromium/v8/src/compiler/map-inference.cc
@@ -68,7 +68,7 @@ bool MapInference::AllOfInstanceTypesUnsafe(
   CHECK(HaveMaps());
 
   auto instance_type = [this, f](Handle<Map> map) {
-    MapRef map_ref(broker_, map);
+    MapRef map_ref = MakeRef(broker_, map);
     return f(map_ref.instance_type());
   };
   return std::all_of(maps_.begin(), maps_.end(), instance_type);
@@ -79,7 +79,7 @@ bool MapInference::AnyOfInstanceTypesUnsafe(
   CHECK(HaveMaps());
 
   auto instance_type = [this, f](Handle<Map> map) {
-    MapRef map_ref(broker_, map);
+    MapRef map_ref = MakeRef(broker_, map);
     return f(map_ref.instance_type());
   };
 
@@ -134,13 +134,13 @@ bool MapInference::RelyOnMapsHelper(CompilationDependencies* dependencies,
   if (Safe()) return true;
 
   auto is_stable = [this](Handle<Map> map) {
-    MapRef map_ref(broker_, map);
+    MapRef map_ref = MakeRef(broker_, map);
     return map_ref.is_stable();
   };
   if (dependencies != nullptr &&
       std::all_of(maps_.cbegin(), maps_.cend(), is_stable)) {
     for (Handle<Map> map : maps_) {
-      dependencies->DependOnStableMap(MapRef(broker_, map));
+      dependencies->DependOnStableMap(MakeRef(broker_, map));
     }
     SetGuarded();
     return true;
diff --git a/chromium/v8/src/compiler/memory-lowering.cc b/chromium/v8/src/compiler/memory-lowering.cc
index b8a75ee9502..ac113ddd70e 100644
--- a/chromium/v8/src/compiler/memory-lowering.cc
+++ b/chromium/v8/src/compiler/memory-lowering.cc
@@ -4,8 +4,9 @@
 
 #include "src/compiler/memory-lowering.h"
 
-#include "src/codegen/interface-descriptors.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/common/external-pointer.h"
+#include "src/compiler/access-builder.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/node-matchers.h"
@@ -41,6 +42,15 @@ class MemoryLowering::AllocationGroup final : public ZoneObject {
   AllocationType const allocation_;
   Node* const size_;
 
+  static inline AllocationType CheckAllocationType(AllocationType allocation) {
+    // For non-generational heap, all young allocations are redirected to old
+    // space.
+    if (FLAG_single_generation && allocation == AllocationType::kYoung) {
+      return AllocationType::kOld;
+    }
+    return allocation;
+  }
+
   DISALLOW_IMPLICIT_CONSTRUCTORS(AllocationGroup);
 };
 
@@ -98,6 +108,9 @@ Reduction MemoryLowering::ReduceAllocateRaw(
   DCHECK_EQ(IrOpcode::kAllocateRaw, node->opcode());
   DCHECK_IMPLIES(allocation_folding_ == AllocationFolding::kDoAllocationFolding,
                  state_ptr != nullptr);
+  if (FLAG_single_generation && allocation_type == AllocationType::kYoung) {
+    allocation_type = AllocationType::kOld;
+  }
   // Code objects may have a maximum size smaller than kMaxHeapObjectSize due to
   // guard pages. If we need to support allocating code here we would need to
   // call MemoryChunkLayout::MaxRegularCodeObjectSize() at runtime.
@@ -292,12 +305,20 @@ Reduction MemoryLowering::ReduceAllocateRaw(
 Reduction MemoryLowering::ReduceLoadFromObject(Node* node) {
   DCHECK_EQ(IrOpcode::kLoadFromObject, node->opcode());
   ObjectAccess const& access = ObjectAccessOf(node->op());
-  MachineRepresentation rep = access.machine_type.representation();
-  const Operator* load_op = ElementSizeInBytes(rep) > kTaggedSize &&
-                                    !machine()->UnalignedLoadSupported(
-                                        access.machine_type.representation())
-                                ? machine()->UnalignedLoad(access.machine_type)
-                                : machine()->Load(access.machine_type);
+
+  MachineType machine_type = access.machine_type;
+
+  if (machine_type.IsMapWord()) {
+    CHECK_EQ(machine_type.semantic(), MachineSemantic::kAny);
+    return ReduceLoadMap(node);
+  }
+
+  MachineRepresentation rep = machine_type.representation();
+  const Operator* load_op =
+      ElementSizeInBytes(rep) > kTaggedSize &&
+              !machine()->UnalignedLoadSupported(machine_type.representation())
+          ? machine()->UnalignedLoad(machine_type)
+          : machine()->Load(machine_type);
   NodeProperties::ChangeOp(node, load_op);
   return Changed(node);
 }
@@ -308,6 +329,7 @@ Reduction MemoryLowering::ReduceLoadElement(Node* node) {
   Node* index = node->InputAt(1);
   node->ReplaceInput(1, ComputeIndex(access, index));
   MachineType type = access.machine_type;
+  DCHECK(!type.IsMapWord());
   if (NeedsPoisoning(access.load_sensitivity)) {
     NodeProperties::ChangeOp(node, machine()->PoisonedLoad(type));
   } else {
@@ -345,8 +367,8 @@ Node* MemoryLowering::DecodeExternalPointer(
   Node* decoded_ptr =
       __ Load(MachineType::Pointer(), table, __ ChangeUint32ToUint64(offset));
   if (external_pointer_tag != 0) {
-    Node* tag = __ IntPtrConstant(external_pointer_tag);
-    decoded_ptr = __ WordXor(decoded_ptr, tag);
+    Node* tag = __ IntPtrConstant(~external_pointer_tag);
+    decoded_ptr = __ WordAnd(decoded_ptr, tag);
   }
   return decoded_ptr;
 #else
@@ -354,6 +376,22 @@ Node* MemoryLowering::DecodeExternalPointer(
 #endif  // V8_HEAP_SANDBOX
 }
 
+Reduction MemoryLowering::ReduceLoadMap(Node* node) {
+#ifdef V8_MAP_PACKING
+  NodeProperties::ChangeOp(node, machine()->Load(MachineType::AnyTagged()));
+
+  Node* effect = NodeProperties::GetEffectInput(node);
+  Node* control = NodeProperties::GetControlInput(node);
+  __ InitializeEffectControl(effect, control);
+
+  node = __ AddNode(graph()->CloneNode(node));
+  return Replace(__ UnpackMapWord(node));
+#else
+  NodeProperties::ChangeOp(node, machine()->Load(MachineType::TaggedPointer()));
+  return Changed(node);
+#endif
+}
+
 Reduction MemoryLowering::ReduceLoadField(Node* node) {
   DCHECK_EQ(IrOpcode::kLoadField, node->opcode());
   FieldAccess const& access = FieldAccessOf(node->op());
@@ -365,11 +403,19 @@ Reduction MemoryLowering::ReduceLoadField(Node* node) {
     // External pointer table indices are 32bit numbers
     type = MachineType::Uint32();
   }
+
+  if (type.IsMapWord()) {
+    DCHECK(!NeedsPoisoning(access.load_sensitivity));
+    DCHECK(!access.type.Is(Type::SandboxedExternalPointer()));
+    return ReduceLoadMap(node);
+  }
+
   if (NeedsPoisoning(access.load_sensitivity)) {
     NodeProperties::ChangeOp(node, machine()->PoisonedLoad(type));
   } else {
     NodeProperties::ChangeOp(node, machine()->Load(type));
   }
+
   if (V8_HEAP_SANDBOX_BOOL &&
       access.type.Is(Type::SandboxedExternalPointer())) {
 #ifdef V8_HEAP_SANDBOX
@@ -391,8 +437,10 @@ Reduction MemoryLowering::ReduceStoreToObject(Node* node,
   ObjectAccess const& access = ObjectAccessOf(node->op());
   Node* object = node->InputAt(0);
   Node* value = node->InputAt(2);
+
   WriteBarrierKind write_barrier_kind = ComputeWriteBarrierKind(
       node, object, value, state, access.write_barrier_kind);
+  DCHECK(!access.machine_type.IsMapWord());
   MachineRepresentation rep = access.machine_type.representation();
   StoreRepresentation store_rep(rep, write_barrier_kind);
   const Operator* store_op = ElementSizeInBytes(rep) > kTaggedSize &&
@@ -427,15 +475,29 @@ Reduction MemoryLowering::ReduceStoreField(Node* node,
   DCHECK_IMPLIES(V8_HEAP_SANDBOX_BOOL,
                  !access.type.Is(Type::ExternalPointer()) &&
                      !access.type.Is(Type::SandboxedExternalPointer()));
+  MachineType machine_type = access.machine_type;
   Node* object = node->InputAt(0);
   Node* value = node->InputAt(1);
+
+  Node* effect = NodeProperties::GetEffectInput(node);
+  Node* control = NodeProperties::GetControlInput(node);
+  __ InitializeEffectControl(effect, control);
+
   WriteBarrierKind write_barrier_kind = ComputeWriteBarrierKind(
       node, object, value, state, access.write_barrier_kind);
   Node* offset = __ IntPtrConstant(access.offset - access.tag());
   node->InsertInput(graph_zone(), 1, offset);
+
+  if (machine_type.IsMapWord()) {
+    machine_type = MachineType::TaggedPointer();
+#ifdef V8_MAP_PACKING
+    Node* mapword = __ PackMapWord(TNode<Map>::UncheckedCast(value));
+    node->ReplaceInput(2, mapword);
+#endif
+  }
   NodeProperties::ChangeOp(
-      node, machine()->Store(StoreRepresentation(
-                access.machine_type.representation(), write_barrier_kind)));
+      node, machine()->Store(StoreRepresentation(machine_type.representation(),
+                                                 write_barrier_kind)));
   return Changed(node);
 }
 
@@ -513,6 +575,9 @@ WriteBarrierKind MemoryLowering::ComputeWriteBarrierKind(
   if (!ValueNeedsWriteBarrier(value, isolate())) {
     write_barrier_kind = kNoWriteBarrier;
   }
+  if (FLAG_disable_write_barriers) {
+    write_barrier_kind = kNoWriteBarrier;
+  }
   if (write_barrier_kind == WriteBarrierKind::kAssertNoWriteBarrier) {
     write_barrier_assert_failed_(node, object, function_debug_name_, zone());
   }
@@ -537,14 +602,18 @@ bool MemoryLowering::NeedsPoisoning(LoadSensitivity load_sensitivity) const {
 MemoryLowering::AllocationGroup::AllocationGroup(Node* node,
                                                  AllocationType allocation,
                                                  Zone* zone)
-    : node_ids_(zone), allocation_(allocation), size_(nullptr) {
+    : node_ids_(zone),
+      allocation_(CheckAllocationType(allocation)),
+      size_(nullptr) {
   node_ids_.insert(node->id());
 }
 
 MemoryLowering::AllocationGroup::AllocationGroup(Node* node,
                                                  AllocationType allocation,
                                                  Node* size, Zone* zone)
-    : node_ids_(zone), allocation_(allocation), size_(size) {
+    : node_ids_(zone),
+      allocation_(CheckAllocationType(allocation)),
+      size_(size) {
   node_ids_.insert(node->id());
 }
 
diff --git a/chromium/v8/src/compiler/memory-lowering.h b/chromium/v8/src/compiler/memory-lowering.h
index 7ad02b95afe..1ebbf40bc82 100644
--- a/chromium/v8/src/compiler/memory-lowering.h
+++ b/chromium/v8/src/compiler/memory-lowering.h
@@ -110,6 +110,7 @@ class MemoryLowering final : public Reducer {
                                            AllocationState const* state,
                                            WriteBarrierKind);
   Node* DecodeExternalPointer(Node* encoded_pointer, ExternalPointerTag tag);
+  Reduction ReduceLoadMap(Node* encoded_pointer);
   Node* ComputeIndex(ElementAccess const& access, Node* node);
   bool NeedsPoisoning(LoadSensitivity load_sensitivity) const;
 
diff --git a/chromium/v8/src/compiler/memory-optimizer.cc b/chromium/v8/src/compiler/memory-optimizer.cc
index 1f36f25c298..7d6dcf880f7 100644
--- a/chromium/v8/src/compiler/memory-optimizer.cc
+++ b/chromium/v8/src/compiler/memory-optimizer.cc
@@ -257,6 +257,15 @@ bool MemoryOptimizer::AllocationTypeNeedsUpdateToOld(Node* const node,
   return false;
 }
 
+void MemoryOptimizer::ReplaceUsesAndKillNode(Node* node, Node* replacement) {
+  // Replace all uses of node and kill the node to make sure we don't leave
+  // dangling dead uses.
+  DCHECK_NE(replacement, node);
+  NodeProperties::ReplaceUses(node, replacement, graph_assembler_.effect(),
+                              graph_assembler_.control());
+  node->Kill();
+}
+
 void MemoryOptimizer::VisitAllocateRaw(Node* node,
                                        AllocationState const* state) {
   DCHECK_EQ(IrOpcode::kAllocateRaw, node->opcode());
@@ -294,12 +303,7 @@ void MemoryOptimizer::VisitAllocateRaw(Node* node,
       node, allocation_type, allocation.allow_large_objects(), &state);
   CHECK(reduction.Changed() && reduction.replacement() != node);
 
-  // Replace all uses of node and kill the node to make sure we don't leave
-  // dangling dead uses.
-  NodeProperties::ReplaceUses(node, reduction.replacement(),
-                              graph_assembler_.effect(),
-                              graph_assembler_.control());
-  node->Kill();
+  ReplaceUsesAndKillNode(node, reduction.replacement());
 
   EnqueueUses(state->effect(), state);
 }
@@ -307,8 +311,11 @@ void MemoryOptimizer::VisitAllocateRaw(Node* node,
 void MemoryOptimizer::VisitLoadFromObject(Node* node,
                                           AllocationState const* state) {
   DCHECK_EQ(IrOpcode::kLoadFromObject, node->opcode());
-  memory_lowering()->ReduceLoadFromObject(node);
+  Reduction reduction = memory_lowering()->ReduceLoadFromObject(node);
   EnqueueUses(node, state);
+  if (V8_MAP_PACKING_BOOL && reduction.replacement() != node) {
+    ReplaceUsesAndKillNode(node, reduction.replacement());
+  }
 }
 
 void MemoryOptimizer::VisitStoreToObject(Node* node,
@@ -333,16 +340,14 @@ void MemoryOptimizer::VisitLoadField(Node* node, AllocationState const* state) {
   // lowering, so we can proceed iterating the graph from the node uses.
   EnqueueUses(node, state);
 
-  // Node can be replaced only when V8_HEAP_SANDBOX_BOOL is enabled and
-  // when loading an external pointer value.
-  DCHECK_IMPLIES(!V8_HEAP_SANDBOX_BOOL, reduction.replacement() == node);
-  if (V8_HEAP_SANDBOX_BOOL && reduction.replacement() != node) {
-    // Replace all uses of node and kill the node to make sure we don't leave
-    // dangling dead uses.
-    NodeProperties::ReplaceUses(node, reduction.replacement(),
-                                graph_assembler_.effect(),
-                                graph_assembler_.control());
-    node->Kill();
+  // Node can be replaced under two cases:
+  //   1. V8_HEAP_SANDBOX_BOOL is enabled and loading an external pointer value.
+  //   2. V8_MAP_PACKING_BOOL is enabled.
+  DCHECK_IMPLIES(!V8_HEAP_SANDBOX_BOOL && !V8_MAP_PACKING_BOOL,
+                 reduction.replacement() == node);
+  if ((V8_HEAP_SANDBOX_BOOL || V8_MAP_PACKING_BOOL) &&
+      reduction.replacement() != node) {
+    ReplaceUsesAndKillNode(node, reduction.replacement());
   }
 }
 
diff --git a/chromium/v8/src/compiler/memory-optimizer.h b/chromium/v8/src/compiler/memory-optimizer.h
index 0f85fea1910..3845304fdd6 100644
--- a/chromium/v8/src/compiler/memory-optimizer.h
+++ b/chromium/v8/src/compiler/memory-optimizer.h
@@ -68,6 +68,8 @@ class MemoryOptimizer final {
   void EnqueueUses(Node*, AllocationState const*);
   void EnqueueUse(Node*, int, AllocationState const*);
 
+  void ReplaceUsesAndKillNode(Node* node, Node* replacement);
+
   // Returns true if the AllocationType of the current AllocateRaw node that we
   // are visiting needs to be updated to kOld, due to propagation of tenuring
   // from outer to inner allocations.
diff --git a/chromium/v8/src/compiler/node-matchers.h b/chromium/v8/src/compiler/node-matchers.h
index e5554d3cba4..05ba661b511 100644
--- a/chromium/v8/src/compiler/node-matchers.h
+++ b/chromium/v8/src/compiler/node-matchers.h
@@ -238,7 +238,14 @@ struct HeapObjectMatcherImpl final
   }
 
   HeapObjectRef Ref(JSHeapBroker* broker) const {
-    return HeapObjectRef(broker, this->ResolvedValue());
+    // TODO(jgruber,chromium:1209798): Using kAssumeMemoryFence works around
+    // the fact that the graph stores handles (and not refs). The assumption is
+    // that any handle inserted into the graph is safe to read; but we don't
+    // preserve the reason why it is safe to read. Thus we must over-approximate
+    // here and assume the existence of a memory fence. In the future, we should
+    // consider having the graph store ObjectRefs or ObjectData pointer instead,
+    // which would make new ref construction here unnecessary.
+    return MakeRefAssumeMemoryFence(broker, this->ResolvedValue());
   }
 };
 
diff --git a/chromium/v8/src/compiler/node-observer.h b/chromium/v8/src/compiler/node-observer.h
index 8978156464e..a6c4619262d 100644
--- a/chromium/v8/src/compiler/node-observer.h
+++ b/chromium/v8/src/compiler/node-observer.h
@@ -80,7 +80,7 @@ class NodeObserver : public ZoneObject {
   bool has_observed_changes() const { return has_observed_changes_; }
 
  private:
-  bool has_observed_changes_ = false;
+  std::atomic<bool> has_observed_changes_{false};
 };
 inline NodeObserver::~NodeObserver() = default;
 
diff --git a/chromium/v8/src/compiler/node-properties.h b/chromium/v8/src/compiler/node-properties.h
index bec18b1e59b..50f3a171361 100644
--- a/chromium/v8/src/compiler/node-properties.h
+++ b/chromium/v8/src/compiler/node-properties.h
@@ -28,7 +28,7 @@ class V8_EXPORT_PRIVATE NodeProperties {
   // Inputs are always arranged in order as follows:
   //     0 [ values, context, frame state, effects, control ] node->InputCount()
 
-  static int FirstValueIndex(Node* node) { return 0; }
+  static int FirstValueIndex(const Node* node) { return 0; }
   static int FirstContextIndex(Node* node) { return PastValueIndex(node); }
   static int FirstFrameStateIndex(Node* node) { return PastContextIndex(node); }
   static int FirstEffectIndex(Node* node) { return PastFrameStateIndex(node); }
@@ -65,6 +65,12 @@ class V8_EXPORT_PRIVATE NodeProperties {
     return node->InputAt(FirstValueIndex(node) + index);
   }
 
+  static const Node* GetValueInput(const Node* node, int index) {
+    CHECK_LE(0, index);
+    CHECK_LT(index, node->op()->ValueInputCount());
+    return node->InputAt(FirstValueIndex(node) + index);
+  }
+
   static Node* GetContextInput(Node* node) {
     CHECK(OperatorProperties::HasContextInput(node->op()));
     return node->InputAt(FirstContextIndex(node));
@@ -249,7 +255,7 @@ class V8_EXPORT_PRIVATE NodeProperties {
   // Type.
 
   static bool IsTyped(const Node* node) { return !node->type().IsInvalid(); }
-  static Type GetType(Node* node) {
+  static Type GetType(const Node* node) {
     DCHECK(IsTyped(node));
     return node->type();
   }
diff --git a/chromium/v8/src/compiler/opcodes.h b/chromium/v8/src/compiler/opcodes.h
index 3e5314d8574..f51c82df487 100644
--- a/chromium/v8/src/compiler/opcodes.h
+++ b/chromium/v8/src/compiler/opcodes.h
@@ -385,7 +385,6 @@
   V(NumberSilenceNaN)
 
 #define SIMPLIFIED_BIGINT_UNOP_LIST(V) \
-  V(BigIntAsUintN)                     \
   V(BigIntNegate)                      \
   V(CheckBigInt)
 
@@ -491,13 +490,16 @@
   V(TransitionAndStoreNumberElement)    \
   V(TransitionElementsKind)             \
   V(TypeOf)                             \
-  V(UpdateInterruptBudget)
+  V(UpdateInterruptBudget)              \
+  V(VerifyType)
 
 #define SIMPLIFIED_SPECULATIVE_BIGINT_BINOP_LIST(V) \
   V(SpeculativeBigIntAdd)                           \
   V(SpeculativeBigIntSubtract)
 
-#define SIMPLIFIED_SPECULATIVE_BIGINT_UNOP_LIST(V) V(SpeculativeBigIntNegate)
+#define SIMPLIFIED_SPECULATIVE_BIGINT_UNOP_LIST(V) \
+  V(SpeculativeBigIntAsUintN)                      \
+  V(SpeculativeBigIntNegate)
 
 #define SIMPLIFIED_OP_LIST(V)                 \
   SIMPLIFIED_CHANGE_OP_LIST(V)                \
@@ -570,6 +572,8 @@
   V(Word64Sar)                   \
   V(Word64Rol)                   \
   V(Word64Ror)                   \
+  V(Word64RolLowerable)          \
+  V(Word64RorLowerable)          \
   V(Int64Add)                    \
   V(Int64AddWithOverflow)        \
   V(Int64Sub)                    \
@@ -688,6 +692,8 @@
   V(Word64Popcnt)                        \
   V(Word64Clz)                           \
   V(Word64Ctz)                           \
+  V(Word64ClzLowerable)                  \
+  V(Word64CtzLowerable)                  \
   V(Word64ReverseBits)                   \
   V(Word64ReverseBytes)                  \
   V(Simd128ReverseBytes)                 \
@@ -734,6 +740,8 @@
   V(Float64ExtractHighWord32)            \
   V(Float64InsertLowWord32)              \
   V(Float64InsertHighWord32)             \
+  V(Word32Select)                        \
+  V(Word64Select)                        \
   V(Float32Select)                       \
   V(Float64Select)                       \
   V(TaggedPoisonOnSpeculation)           \
diff --git a/chromium/v8/src/compiler/operation-typer.cc b/chromium/v8/src/compiler/operation-typer.cc
index 8b889c6948a..9e5816559e5 100644
--- a/chromium/v8/src/compiler/operation-typer.cc
+++ b/chromium/v8/src/compiler/operation-typer.cc
@@ -576,8 +576,7 @@ Type OperationTyper::NumberSilenceNaN(Type type) {
   return type;
 }
 
-Type OperationTyper::BigIntAsUintN(Type type) {
-  DCHECK(type.Is(Type::BigInt()));
+Type OperationTyper::SpeculativeBigIntAsUintN(Type type) {
   return Type::BigInt();
 }
 
@@ -1263,14 +1262,12 @@ Type OperationTyper::StrictEqual(Type lhs, Type rhs) {
 Type OperationTyper::CheckBounds(Type index, Type length) {
   DCHECK(length.Is(cache_->kPositiveSafeInteger));
   if (length.Is(cache_->kSingletonZero)) return Type::None();
-  Type mask = Type::Range(0.0, length.Max() - 1, zone());
+  Type const upper_bound = Type::Range(0.0, length.Max() - 1, zone());
+  if (index.Maybe(Type::String())) return upper_bound;
   if (index.Maybe(Type::MinusZero())) {
     index = Type::Union(index, cache_->kSingletonZero, zone());
   }
-  if (index.Maybe(Type::String())) {
-    index = Type::Union(index, cache_->kIntPtr, zone());
-  }
-  return Type::Intersect(index, mask, zone());
+  return Type::Intersect(index, upper_bound, zone());
 }
 
 Type OperationTyper::CheckFloat64Hole(Type type) {
diff --git a/chromium/v8/src/compiler/operator.h b/chromium/v8/src/compiler/operator.h
index e47441208f1..4206e753f1e 100644
--- a/chromium/v8/src/compiler/operator.h
+++ b/chromium/v8/src/compiler/operator.h
@@ -5,7 +5,7 @@
 #ifndef V8_COMPILER_OPERATOR_H_
 #define V8_COMPILER_OPERATOR_H_
 
-#include <ostream>  // NOLINT(readability/streams)
+#include <ostream>
 
 #include "src/base/compiler-specific.h"
 #include "src/base/flags.h"
diff --git a/chromium/v8/src/compiler/pipeline.cc b/chromium/v8/src/compiler/pipeline.cc
index f80f3064cef..2ce65780ca3 100644
--- a/chromium/v8/src/compiler/pipeline.cc
+++ b/chromium/v8/src/compiler/pipeline.cc
@@ -4,7 +4,7 @@
 
 #include "src/compiler/pipeline.h"
 
-#include <fstream>  // NOLINT(readability/streams)
+#include <fstream>
 #include <iostream>
 #include <memory>
 #include <sstream>
@@ -67,7 +67,6 @@
 #include "src/compiler/pipeline-statistics.h"
 #include "src/compiler/redundancy-elimination.h"
 #include "src/compiler/schedule.h"
-#include "src/compiler/scheduled-machine-lowering.h"
 #include "src/compiler/scheduler.h"
 #include "src/compiler/select-lowering.h"
 #include "src/compiler/serializer-for-background-compilation.h"
@@ -139,8 +138,7 @@ class PipelineData {
   // For main entry point.
   PipelineData(ZoneStats* zone_stats, Isolate* isolate,
                OptimizedCompilationInfo* info,
-               PipelineStatistics* pipeline_statistics,
-               bool is_concurrent_inlining)
+               PipelineStatistics* pipeline_statistics)
       : isolate_(isolate),
         allocator_(isolate->allocator()),
         info_(info),
@@ -157,9 +155,9 @@ class PipelineData {
         instruction_zone_(instruction_zone_scope_.zone()),
         codegen_zone_scope_(zone_stats_, kCodegenZoneName),
         codegen_zone_(codegen_zone_scope_.zone()),
-        broker_(new JSHeapBroker(isolate_, info_->zone(),
-                                 info_->trace_heap_broker(),
-                                 is_concurrent_inlining, info->code_kind())),
+        broker_(new JSHeapBroker(
+            isolate_, info_->zone(), info_->trace_heap_broker(),
+            info_->concurrent_inlining(), info->code_kind())),
         register_allocation_zone_scope_(zone_stats_,
                                         kRegisterAllocationZoneName),
         register_allocation_zone_(register_allocation_zone_scope_.zone()),
@@ -783,6 +781,7 @@ class NodeOriginsWrapper final : public Reducer {
 
 class V8_NODISCARD PipelineRunScope {
  public:
+#ifdef V8_RUNTIME_CALL_STATS
   PipelineRunScope(
       PipelineData* data, const char* phase_name,
       RuntimeCallCounterId runtime_call_counter_id,
@@ -794,6 +793,14 @@ class V8_NODISCARD PipelineRunScope {
                                  runtime_call_counter_id, counter_mode) {
     DCHECK_NOT_NULL(phase_name);
   }
+#else   // V8_RUNTIME_CALL_STATS
+  PipelineRunScope(PipelineData* data, const char* phase_name)
+      : phase_scope_(data->pipeline_statistics(), phase_name),
+        zone_scope_(data->zone_stats(), phase_name),
+        origin_scope_(data->node_origins(), phase_name) {
+    DCHECK_NOT_NULL(phase_name);
+  }
+#endif  // V8_RUNTIME_CALL_STATS
 
   Zone* zone() { return zone_scope_.zone(); }
 
@@ -801,7 +808,9 @@ class V8_NODISCARD PipelineRunScope {
   PhaseScope phase_scope_;
   ZoneStats::Scope zone_scope_;
   NodeOriginTable::PhaseScope origin_scope_;
+#ifdef V8_RUNTIME_CALL_STATS
   RuntimeCallTimerScope runtime_call_timer_scope;
+#endif  // V8_RUNTIME_CALL_STATS
 };
 
 // LocalIsolateScope encapsulates the phase where persistent handles are
@@ -902,8 +911,7 @@ void PrintCode(Isolate* isolate, Handle<Code> code,
   const bool print_code =
       FLAG_print_code ||
       (info->IsOptimizing() && FLAG_print_opt_code &&
-       info->shared_info()->PassesFilter(FLAG_print_opt_code_filter)) ||
-      (info->IsNativeContextIndependent() && FLAG_print_nci_code);
+       info->shared_info()->PassesFilter(FLAG_print_opt_code_filter));
   if (print_code) {
     std::unique_ptr<char[]> debug_name = info->GetDebugName();
     CodeTracer::StreamScope tracing_scope(isolate->GetCodeTracer());
@@ -1095,15 +1103,6 @@ class PipelineCompilationJob final : public OptimizedCompilationJob {
   Linkage* linkage_;
 };
 
-namespace {
-
-bool ShouldUseConcurrentInlining(CodeKind code_kind, bool is_osr) {
-  if (is_osr) return false;
-  return code_kind == CodeKind::TURBOPROP || FLAG_concurrent_inlining;
-}
-
-}  // namespace
-
 PipelineCompilationJob::PipelineCompilationJob(
     Isolate* isolate, Handle<SharedFunctionInfo> shared_info,
     Handle<JSFunction> function, BytecodeOffset osr_offset,
@@ -1116,17 +1115,14 @@ PipelineCompilationJob::PipelineCompilationJob(
             kPipelineCompilationJobZoneName),
       zone_stats_(function->GetIsolate()->allocator()),
       compilation_info_(&zone_, function->GetIsolate(), shared_info, function,
-                        code_kind),
+                        code_kind, osr_offset, osr_frame),
       pipeline_statistics_(CreatePipelineStatistics(
           handle(Script::cast(shared_info->script()), isolate),
           compilation_info(), function->GetIsolate(), &zone_stats_)),
       data_(&zone_stats_, function->GetIsolate(), compilation_info(),
-            pipeline_statistics_.get(),
-            ShouldUseConcurrentInlining(code_kind, !osr_offset.IsNone())),
+            pipeline_statistics_.get()),
       pipeline_(&data_),
-      linkage_(nullptr) {
-  compilation_info_.SetOptimizingForOsr(osr_offset, osr_frame);
-}
+      linkage_(nullptr) {}
 
 PipelineCompilationJob::~PipelineCompilationJob() = default;
 
@@ -1159,14 +1155,13 @@ PipelineCompilationJob::Status PipelineCompilationJob::PrepareJobImpl(
     return AbortOptimization(BailoutReason::kFunctionTooBig);
   }
 
-  if (!FLAG_always_opt && !compilation_info()->IsNativeContextIndependent()) {
+  if (!FLAG_always_opt) {
     compilation_info()->set_bailout_on_uninitialized();
   }
   if (FLAG_turbo_loop_peeling) {
     compilation_info()->set_loop_peeling();
   }
-  if (FLAG_turbo_inlining && !compilation_info()->IsTurboprop() &&
-      !compilation_info()->IsNativeContextIndependent()) {
+  if (FLAG_turbo_inlining && !compilation_info()->IsTurboprop()) {
     compilation_info()->set_inlining();
   }
 
@@ -1188,13 +1183,11 @@ PipelineCompilationJob::Status PipelineCompilationJob::PrepareJobImpl(
   // Determine whether to specialize the code for the function's context.
   // We can't do this in the case of OSR, because we want to cache the
   // generated code on the native context keyed on SharedFunctionInfo.
-  // We also can't do this for native context independent code (yet).
   // TODO(mythria): Check if it is better to key the OSR cache on JSFunction and
   // allow context specialization for OSR code.
   if (compilation_info()->closure()->raw_feedback_cell().map() ==
           ReadOnlyRoots(isolate).one_closure_cell_map() &&
       !compilation_info()->is_osr() &&
-      !compilation_info()->IsNativeContextIndependent() &&
       !compilation_info()->IsTurboprop()) {
     compilation_info()->set_function_context_specializing();
     data_.ChooseSpecializationContext();
@@ -1222,7 +1215,7 @@ PipelineCompilationJob::Status PipelineCompilationJob::PrepareJobImpl(
     }
   }
 
-  if (FLAG_turbo_direct_heap_access) {
+  if (compilation_info()->concurrent_inlining()) {
     isolate->heap()->PublishPendingAllocations();
   }
 
@@ -1262,8 +1255,7 @@ PipelineCompilationJob::Status PipelineCompilationJob::FinalizeJobImpl(
   // Ensure that the RuntimeCallStats table of main thread is available for
   // phases happening during PrepareJob.
   PipelineJobScope scope(&data_, isolate->counters()->runtime_call_stats());
-  RuntimeCallTimerScope runtimeTimer(
-      isolate, RuntimeCallCounterId::kOptimizeFinalizePipelineJob);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kOptimizeFinalizePipelineJob);
   MaybeHandle<Code> maybe_code = pipeline_.FinalizeCode();
   Handle<Code> code;
   if (!maybe_code.ToHandle(&code)) {
@@ -1309,17 +1301,26 @@ void PipelineCompilationJob::RegisterWeakObjectsInOptimizedCode(
 
 template <typename Phase, typename... Args>
 void PipelineImpl::Run(Args&&... args) {
+#ifdef V8_RUNTIME_CALL_STATS
   PipelineRunScope scope(this->data_, Phase::phase_name(),
                          Phase::kRuntimeCallCounterId, Phase::kCounterMode);
+#else
+  PipelineRunScope scope(this->data_, Phase::phase_name());
+#endif
   Phase phase;
   phase.Run(this->data_, scope.zone(), std::forward<Args>(args)...);
 }
 
+#ifdef V8_RUNTIME_CALL_STATS
 #define DECL_PIPELINE_PHASE_CONSTANTS_HELPER(Name, Mode)        \
   static const char* phase_name() { return "V8.TF" #Name; }     \
   static constexpr RuntimeCallCounterId kRuntimeCallCounterId = \
       RuntimeCallCounterId::kOptimize##Name;                    \
   static constexpr RuntimeCallStats::CounterMode kCounterMode = Mode;
+#else  // V8_RUNTIME_CALL_STATS
+#define DECL_PIPELINE_PHASE_CONSTANTS_HELPER(Name, Mode) \
+  static const char* phase_name() { return "V8.TF" #Name; }
+#endif  // V8_RUNTIME_CALL_STATS
 
 #define DECL_PIPELINE_PHASE_CONSTANTS(Name) \
   DECL_PIPELINE_PHASE_CONSTANTS_HELPER(Name, RuntimeCallStats::kThreadSpecific)
@@ -1339,7 +1340,7 @@ struct GraphBuilderPhase {
       flags |= BytecodeGraphBuilderFlag::kBailoutOnUninitialized;
     }
 
-    JSFunctionRef closure(data->broker(), data->info()->closure());
+    JSFunctionRef closure = MakeRef(data->broker(), data->info()->closure());
     CallFrequency frequency(1.0f);
     BuildGraphFromBytecode(
         data->broker(), temp_zone, closure.shared(),
@@ -1361,7 +1362,8 @@ struct InliningPhase {
                                data->broker(), data->jsgraph()->Dead(),
                                data->observe_node_manager());
     DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
-                                              data->common(), temp_zone);
+                                              data->common(), temp_zone,
+                                              info->concurrent_inlining());
     CheckpointElimination checkpoint_elimination(&graph_reducer);
     CommonOperatorReducer common_reducer(&graph_reducer, data->graph(),
                                          data->broker(), data->common(),
@@ -1370,7 +1372,7 @@ struct InliningPhase {
     if (data->info()->bailout_on_uninitialized()) {
       call_reducer_flags |= JSCallReducer::kBailoutOnUninitialized;
     }
-    if (FLAG_turbo_inline_js_wasm_calls && data->info()->inlining()) {
+    if (data->info()->inline_js_wasm_calls() && data->info()->inlining()) {
       call_reducer_flags |= JSCallReducer::kInlineJSToWasmCalls;
     }
     JSCallReducer call_reducer(&graph_reducer, data->jsgraph(), data->broker(),
@@ -1400,12 +1402,12 @@ struct InliningPhase {
     JSIntrinsicLowering intrinsic_lowering(&graph_reducer, data->jsgraph(),
                                            data->broker());
     AddReducer(data, &graph_reducer, &dead_code_elimination);
-    AddReducer(data, &graph_reducer, &checkpoint_elimination);
-    AddReducer(data, &graph_reducer, &common_reducer);
-    if (!data->info()->IsNativeContextIndependent()) {
-      AddReducer(data, &graph_reducer, &native_context_specialization);
-      AddReducer(data, &graph_reducer, &context_specialization);
+    if (!data->info()->IsTurboprop()) {
+      AddReducer(data, &graph_reducer, &checkpoint_elimination);
+      AddReducer(data, &graph_reducer, &common_reducer);
     }
+    AddReducer(data, &graph_reducer, &native_context_specialization);
+    AddReducer(data, &graph_reducer, &context_specialization);
     AddReducer(data, &graph_reducer, &intrinsic_lowering);
     AddReducer(data, &graph_reducer, &call_reducer);
     if (data->info()->inlining()) {
@@ -1431,7 +1433,8 @@ struct WasmInliningPhase {
     GraphReducer graph_reducer(temp_zone, data->graph(), &info->tick_counter(),
                                data->broker(), data->jsgraph()->Dead());
     DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
-                                              data->common(), temp_zone);
+                                              data->common(), temp_zone,
+                                              info->concurrent_inlining());
     CommonOperatorReducer common_reducer(&graph_reducer, data->graph(),
                                          data->broker(), data->common(),
                                          data->machine(), temp_zone);
@@ -1503,7 +1506,7 @@ struct HeapBrokerInitializationPhase {
   DECL_MAIN_THREAD_PIPELINE_PHASE_CONSTANTS(HeapBrokerInitialization)
 
   void Run(PipelineData* data, Zone* temp_zone) {
-    data->broker()->InitializeAndStartSerializing(data->native_context());
+    data->broker()->InitializeAndStartSerializing();
   }
 };
 
@@ -1547,8 +1550,16 @@ struct SerializationPhase {
         data->zone_stats(), data->broker(), data->dependencies(),
         data->info()->closure(), flags, data->info()->osr_offset());
     if (data->specialization_context().IsJust()) {
-      ContextRef(data->broker(),
-                 data->specialization_context().FromJust().context);
+      MakeRef(data->broker(),
+              data->specialization_context().FromJust().context);
+    }
+    if (FLAG_turbo_concurrent_get_property_access_info) {
+      data->broker()->ClearCachedPropertyAccessInfos();
+      data->dependencies()->ClearForConcurrentGetPropertyAccessInfo();
+    }
+    if (FLAG_stress_concurrent_inlining) {
+      // Force re-serialization from the background thread.
+      data->broker()->ClearReconstructibleData();
     }
   }
 };
@@ -1560,8 +1571,9 @@ struct TypedLoweringPhase {
     GraphReducer graph_reducer(
         temp_zone, data->graph(), &data->info()->tick_counter(), data->broker(),
         data->jsgraph()->Dead(), data->observe_node_manager());
-    DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
-                                              data->common(), temp_zone);
+    DeadCodeElimination dead_code_elimination(
+        &graph_reducer, data->graph(), data->common(), temp_zone,
+        data->info()->concurrent_inlining());
     JSCreateLowering create_lowering(&graph_reducer, data->dependencies(),
                                      data->jsgraph(), data->broker(),
                                      temp_zone);
@@ -1579,10 +1591,10 @@ struct TypedLoweringPhase {
                                          data->machine(), temp_zone);
     AddReducer(data, &graph_reducer, &dead_code_elimination);
 
-    if (!data->info()->IsNativeContextIndependent()) {
-      AddReducer(data, &graph_reducer, &create_lowering);
+    AddReducer(data, &graph_reducer, &create_lowering);
+    if (!data->info()->IsTurboprop()) {
+      AddReducer(data, &graph_reducer, &constant_folding_reducer);
     }
-    AddReducer(data, &graph_reducer, &constant_folding_reducer);
     AddReducer(data, &graph_reducer, &typed_lowering);
     AddReducer(data, &graph_reducer, &typed_optimization);
     AddReducer(data, &graph_reducer, &simple_reducer);
@@ -1747,8 +1759,9 @@ struct EarlyOptimizationPhase {
     GraphReducer graph_reducer(
         temp_zone, data->graph(), &data->info()->tick_counter(), data->broker(),
         data->jsgraph()->Dead(), data->observe_node_manager());
-    DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
-                                              data->common(), temp_zone);
+    DeadCodeElimination dead_code_elimination(
+        &graph_reducer, data->graph(), data->common(), temp_zone,
+        data->info()->concurrent_inlining());
     SimplifiedOperatorReducer simple_reducer(&graph_reducer, data->jsgraph(),
                                              data->broker());
     RedundancyElimination redundancy_elimination(&graph_reducer, temp_zone);
@@ -1804,11 +1817,6 @@ struct EffectControlLinearizationPhase {
       TraceScheduleAndVerify(data->info(), data, schedule,
                              "effect linearization schedule");
 
-      MaskArrayIndexEnable mask_array_index =
-          (data->info()->GetPoisoningMitigationLevel() !=
-           PoisoningMitigationLevel::kDontPoison)
-              ? MaskArrayIndexEnable::kMaskArrayIndex
-              : MaskArrayIndexEnable::kDoNotMaskArrayIndex;
       // Post-pass for wiring the control/effects
       // - connect allocating representation changes into the control&effect
       //   chains and lower them,
@@ -1816,7 +1824,7 @@ struct EffectControlLinearizationPhase {
       // - introduce effect phis and rewire effects to get SSA again.
       LinearizeEffectControl(data->jsgraph(), schedule, temp_zone,
                              data->source_positions(), data->node_origins(),
-                             mask_array_index, MaintainSchedule::kDiscard,
+                             data->info()->GetPoisoningMitigationLevel(),
                              data->broker());
     }
     {
@@ -1829,8 +1837,9 @@ struct EffectControlLinearizationPhase {
                                  &data->info()->tick_counter(), data->broker(),
                                  data->jsgraph()->Dead(),
                                  data->observe_node_manager());
-      DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
-                                                data->common(), temp_zone);
+      DeadCodeElimination dead_code_elimination(
+          &graph_reducer, data->graph(), data->common(), temp_zone,
+          data->info()->concurrent_inlining());
       CommonOperatorReducer common_reducer(&graph_reducer, data->graph(),
                                            data->broker(), data->common(),
                                            data->machine(), temp_zone);
@@ -1868,8 +1877,9 @@ struct LoadEliminationPhase {
     BranchElimination branch_condition_elimination(&graph_reducer,
                                                    data->jsgraph(), temp_zone,
                                                    BranchElimination::kEARLY);
-    DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
-                                              data->common(), temp_zone);
+    DeadCodeElimination dead_code_elimination(
+        &graph_reducer, data->graph(), data->common(), temp_zone,
+        data->info()->concurrent_inlining());
     RedundancyElimination redundancy_elimination(&graph_reducer, temp_zone);
     LoadElimination load_elimination(&graph_reducer, data->jsgraph(),
                                      temp_zone);
@@ -1936,8 +1946,9 @@ struct LateOptimizationPhase {
         data->jsgraph()->Dead(), data->observe_node_manager());
     BranchElimination branch_condition_elimination(&graph_reducer,
                                                    data->jsgraph(), temp_zone);
-    DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
-                                              data->common(), temp_zone);
+    DeadCodeElimination dead_code_elimination(
+        &graph_reducer, data->graph(), data->common(), temp_zone,
+        data->info()->concurrent_inlining());
     ValueNumberingReducer value_numbering(temp_zone, data->graph()->zone());
     MachineOperatorReducer machine_reducer(&graph_reducer, data->jsgraph());
     CommonOperatorReducer common_reducer(&graph_reducer, data->graph(),
@@ -2000,43 +2011,22 @@ struct ScheduledEffectControlLinearizationPhase {
   DECL_PIPELINE_PHASE_CONSTANTS(ScheduledEffectControlLinearization)
 
   void Run(PipelineData* data, Zone* temp_zone) {
-    MaskArrayIndexEnable mask_array_index =
-        (data->info()->GetPoisoningMitigationLevel() !=
-         PoisoningMitigationLevel::kDontPoison)
-            ? MaskArrayIndexEnable::kMaskArrayIndex
-            : MaskArrayIndexEnable::kDoNotMaskArrayIndex;
     // Post-pass for wiring the control/effects
     // - connect allocating representation changes into the control&effect
     //   chains and lower them,
     // - get rid of the region markers,
-    // - introduce effect phis and rewire effects to get SSA again.
-    LinearizeEffectControl(data->jsgraph(), data->schedule(), temp_zone,
+    // - introduce effect phis and rewire effects to get SSA again,
+    // - lower simplified memory and select nodes to machine level nodes.
+    LowerToMachineSchedule(data->jsgraph(), data->schedule(), temp_zone,
                            data->source_positions(), data->node_origins(),
-                           mask_array_index, MaintainSchedule::kMaintain,
+                           data->info()->GetPoisoningMitigationLevel(),
                            data->broker());
 
     // TODO(rmcilroy) Avoid having to rebuild rpo_order on schedule each time.
     Scheduler::ComputeSpecialRPO(temp_zone, data->schedule());
-    if (FLAG_turbo_verify) Scheduler::GenerateDominatorTree(data->schedule());
-    TraceScheduleAndVerify(data->info(), data, data->schedule(),
-                           "effect linearization schedule");
-  }
-};
-
-struct ScheduledMachineLoweringPhase {
-  DECL_PIPELINE_PHASE_CONSTANTS(ScheduledMachineLowering)
-
-  void Run(PipelineData* data, Zone* temp_zone) {
-    ScheduledMachineLowering machine_lowering(
-        data->jsgraph(), data->schedule(), temp_zone, data->source_positions(),
-        data->node_origins(), data->info()->GetPoisoningMitigationLevel());
-    machine_lowering.Run();
-
-    // TODO(rmcilroy) Avoid having to rebuild rpo_order on schedule each time.
-    Scheduler::ComputeSpecialRPO(temp_zone, data->schedule());
     Scheduler::GenerateDominatorTree(data->schedule());
     TraceScheduleAndVerify(data->info(), data, data->schedule(),
-                           "machine lowered schedule");
+                           "effect linearization schedule");
   }
 };
 
@@ -2051,8 +2041,9 @@ struct CsaEarlyOptimizationPhase {
                                            allow_signalling_nan);
     BranchElimination branch_condition_elimination(&graph_reducer,
                                                    data->jsgraph(), temp_zone);
-    DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
-                                              data->common(), temp_zone);
+    DeadCodeElimination dead_code_elimination(
+        &graph_reducer, data->graph(), data->common(), temp_zone,
+        data->info()->concurrent_inlining());
     CommonOperatorReducer common_reducer(&graph_reducer, data->graph(),
                                          data->broker(), data->common(),
                                          data->machine(), temp_zone);
@@ -2078,8 +2069,9 @@ struct CsaOptimizationPhase {
         data->jsgraph()->Dead(), data->observe_node_manager());
     BranchElimination branch_condition_elimination(&graph_reducer,
                                                    data->jsgraph(), temp_zone);
-    DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
-                                              data->common(), temp_zone);
+    DeadCodeElimination dead_code_elimination(
+        &graph_reducer, data->graph(), data->common(), temp_zone,
+        data->info()->concurrent_inlining());
     MachineOperatorReducer machine_reducer(&graph_reducer, data->jsgraph(),
                                            allow_signalling_nan);
     CommonOperatorReducer common_reducer(&graph_reducer, data->graph(),
@@ -2653,12 +2645,15 @@ bool PipelineImpl::CreateGraph() {
   RunPrintAndVerify(InliningPhase::phase_name(), true);
 
   // Remove dead->live edges from the graph.
-  Run<EarlyGraphTrimmingPhase>();
-  RunPrintAndVerify(EarlyGraphTrimmingPhase::phase_name(), true);
+  if (!data->info()->IsTurboprop()) {
+    Run<EarlyGraphTrimmingPhase>();
+    RunPrintAndVerify(EarlyGraphTrimmingPhase::phase_name(), true);
+  }
 
   // Determine the Typer operation flags.
   {
-    SharedFunctionInfoRef shared_info(data->broker(), info()->shared_info());
+    SharedFunctionInfoRef shared_info =
+        MakeRef(data->broker(), info()->shared_info());
     if (is_sloppy(shared_info.language_mode()) &&
         shared_info.IsUserJavaScript()) {
       // Sloppy mode functions always have an Object for this.
@@ -2735,7 +2730,7 @@ bool PipelineImpl::OptimizeGraph(Linkage* linkage) {
 
 #if V8_ENABLE_WEBASSEMBLY
   if (data->has_js_wasm_calls()) {
-    DCHECK(FLAG_turbo_inline_js_wasm_calls);
+    DCHECK(data->info()->inline_js_wasm_calls());
     Run<WasmInliningPhase>();
     RunPrintAndVerify(WasmInliningPhase::phase_name(), true);
   }
@@ -2862,9 +2857,6 @@ bool PipelineImpl::OptimizeGraphForMidTier(Linkage* linkage) {
   RunPrintAndVerify(ScheduledEffectControlLinearizationPhase::phase_name(),
                     true);
 
-  Run<ScheduledMachineLoweringPhase>();
-  RunPrintAndVerify(ScheduledMachineLoweringPhase::phase_name(), true);
-
   data->source_positions()->RemoveDecorator();
   if (data->info()->trace_turbo_json()) {
     data->node_origins()->RemoveDecorator();
@@ -2966,8 +2958,7 @@ MaybeHandle<Code> Pipeline::GenerateCodeForCodeStub(
                     should_optimize_jumps ? &jump_opt : nullptr, options,
                     profile_data);
   PipelineJobScope scope(&data, isolate->counters()->runtime_call_stats());
-  RuntimeCallTimerScope timer_scope(isolate,
-                                    RuntimeCallCounterId::kOptimizeCode);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kOptimizeCode);
   data.set_verify_graph(FLAG_verify_csa);
   std::unique_ptr<PipelineStatistics> pipeline_statistics;
   if (FLAG_turbo_stats || FLAG_turbo_stats_nvp) {
@@ -3290,8 +3281,7 @@ MaybeHandle<Code> Pipeline::GenerateCodeForTesting(
       CreatePipelineStatistics(Handle<Script>::null(), info, isolate,
                                &zone_stats));
 
-  PipelineData data(&zone_stats, isolate, info, pipeline_statistics.get(),
-                    i::FLAG_concurrent_inlining);
+  PipelineData data(&zone_stats, isolate, info, pipeline_statistics.get());
   PipelineImpl pipeline(&data);
 
   Linkage linkage(Linkage::ComputeIncoming(data.instruction_zone(), info));
@@ -3422,8 +3412,10 @@ void PipelineImpl::ComputeScheduledGraph() {
   // We should only schedule the graph if it is not scheduled yet.
   DCHECK_NULL(data->schedule());
 
-  Run<LateGraphTrimmingPhase>();
-  RunPrintAndVerify(LateGraphTrimmingPhase::phase_name(), true);
+  if (!data->info()->IsTurboprop()) {
+    Run<LateGraphTrimmingPhase>();
+    RunPrintAndVerify(LateGraphTrimmingPhase::phase_name(), true);
+  }
 
   Run<ComputeSchedulePhase>();
   TraceScheduleAndVerify(data->info(), data, data->schedule(), "schedule");
diff --git a/chromium/v8/src/compiler/processed-feedback.h b/chromium/v8/src/compiler/processed-feedback.h
index 4cecd338c54..78163a23a7c 100644
--- a/chromium/v8/src/compiler/processed-feedback.h
+++ b/chromium/v8/src/compiler/processed-feedback.h
@@ -197,20 +197,24 @@ class MinimorphicLoadPropertyAccessFeedback : public ProcessedFeedback {
 class CallFeedback : public ProcessedFeedback {
  public:
   CallFeedback(base::Optional<HeapObjectRef> target, float frequency,
-               SpeculationMode mode, FeedbackSlotKind slot_kind)
+               SpeculationMode mode, CallFeedbackContent call_feedback_content,
+               FeedbackSlotKind slot_kind)
       : ProcessedFeedback(kCall, slot_kind),
         target_(target),
         frequency_(frequency),
-        mode_(mode) {}
+        mode_(mode),
+        content_(call_feedback_content) {}
 
   base::Optional<HeapObjectRef> target() const { return target_; }
   float frequency() const { return frequency_; }
   SpeculationMode speculation_mode() const { return mode_; }
+  CallFeedbackContent call_feedback_content() const { return content_; }
 
  private:
   base::Optional<HeapObjectRef> const target_;
   float const frequency_;
   SpeculationMode const mode_;
+  CallFeedbackContent const content_;
 };
 
 template <class T, ProcessedFeedback::Kind K>
diff --git a/chromium/v8/src/compiler/property-access-builder.cc b/chromium/v8/src/compiler/property-access-builder.cc
index c5a70555a7d..317d21a7128 100644
--- a/chromium/v8/src/compiler/property-access-builder.cc
+++ b/chromium/v8/src/compiler/property-access-builder.cc
@@ -35,7 +35,7 @@ SimplifiedOperatorBuilder* PropertyAccessBuilder::simplified() const {
 bool HasOnlyStringMaps(JSHeapBroker* broker,
                        ZoneVector<Handle<Map>> const& maps) {
   for (auto map : maps) {
-    MapRef map_ref(broker, map);
+    MapRef map_ref = MakeRef(broker, map);
     if (!map_ref.IsStringMap()) return false;
   }
   return true;
@@ -46,7 +46,7 @@ namespace {
 bool HasOnlyNumberMaps(JSHeapBroker* broker,
                        ZoneVector<Handle<Map>> const& maps) {
   for (auto map : maps) {
-    MapRef map_ref(broker, map);
+    MapRef map_ref = MakeRef(broker, map);
     if (map_ref.instance_type() != HEAP_NUMBER_TYPE) return false;
   }
   return true;
@@ -89,7 +89,7 @@ void PropertyAccessBuilder::BuildCheckMaps(
     MapRef object_map = m.Ref(broker()).map();
     if (object_map.is_stable()) {
       for (Handle<Map> map : maps) {
-        if (MapRef(broker(), map).equals(object_map)) {
+        if (MakeRef(broker(), map).equals(object_map)) {
           dependencies()->DependOnStableMap(object_map);
           return;
         }
@@ -99,7 +99,7 @@ void PropertyAccessBuilder::BuildCheckMaps(
   ZoneHandleSet<Map> map_set;
   CheckMapsFlags flags = CheckMapsFlag::kNone;
   for (Handle<Map> map : maps) {
-    MapRef object_map(broker(), map);
+    MapRef object_map = MakeRef(broker(), map);
     map_set.insert(object_map.object(), graph()->zone());
     if (object_map.is_migration_target()) {
       flags |= CheckMapsFlag::kTryMigrateInstance;
@@ -153,7 +153,8 @@ Node* PropertyAccessBuilder::FoldLoadDictPrototypeConstant(
   DCHECK(V8_DICT_PROPERTY_CONST_TRACKING_BOOL);
   DCHECK(access_info.IsDictionaryProtoDataConstant());
 
-  JSObjectRef holder(broker(), access_info.holder().ToHandleChecked());
+  JSObjectRef holder =
+      MakeRef(broker(), access_info.holder().ToHandleChecked());
   base::Optional<ObjectRef> value =
       holder.GetOwnDictionaryProperty(access_info.dictionary_index());
 
@@ -163,15 +164,15 @@ Node* PropertyAccessBuilder::FoldLoadDictPrototypeConstant(
     if (!map->IsJSReceiverMap()) {
       // Perform the implicit ToObject for primitives here.
       // Implemented according to ES6 section 7.3.2 GetV (V, P).
-      Handle<JSFunction> constructor =
+      JSFunction constructor =
           Map::GetConstructorFunction(
-              map, broker()->target_native_context().object())
-              .ToHandleChecked();
-      map = handle(constructor->initial_map(), isolate());
+              *map, *broker()->target_native_context().object())
+              .value();
+      map = handle(constructor.initial_map(), isolate());
       DCHECK(map->IsJSObjectMap());
     }
     dependencies()->DependOnConstantInDictionaryPrototypeChain(
-        MapRef{broker(), map}, NameRef{broker(), access_info.name()},
+        MakeRef(broker(), map), MakeRef(broker(), access_info.name()),
         value.value(), PropertyKind::kData);
   }
 
@@ -197,7 +198,7 @@ Node* PropertyAccessBuilder::TryFoldLoadConstantDataField(
     if (std::find_if(
             access_info.lookup_start_object_maps().begin(),
             access_info.lookup_start_object_maps().end(), [&](Handle<Map> map) {
-              return MapRef(broker(), map).equals(lookup_start_object_map);
+              return MakeRef(broker(), map).equals(lookup_start_object_map);
             }) == access_info.lookup_start_object_maps().end()) {
       // The map of the lookup_start_object is not in the feedback, let us bail
       // out.
@@ -206,7 +207,7 @@ Node* PropertyAccessBuilder::TryFoldLoadConstantDataField(
     holder = m.Ref(broker()).AsJSObject().object();
   }
 
-  JSObjectRef holder_ref(broker(), holder);
+  JSObjectRef holder_ref = MakeRef(broker(), holder);
   base::Optional<ObjectRef> value = holder_ref.GetOwnFastDataProperty(
       access_info.field_representation(), access_info.field_index());
   if (!value.has_value()) {
@@ -329,7 +330,7 @@ Node* PropertyAccessBuilder::BuildLoadDataField(
     // used by the LoadElimination to eliminate map checks on the result.
     Handle<Map> field_map;
     if (access_info.field_map().ToHandle(&field_map)) {
-      MapRef field_map_ref(broker(), field_map);
+      MapRef field_map_ref = MakeRef(broker(), field_map);
       if (field_map_ref.is_stable()) {
         dependencies()->DependOnStableMap(field_map_ref);
         field_access.map = field_map;
diff --git a/chromium/v8/src/compiler/raw-machine-assembler.cc b/chromium/v8/src/compiler/raw-machine-assembler.cc
index f79776bad99..7ed217d4e36 100644
--- a/chromium/v8/src/compiler/raw-machine-assembler.cc
+++ b/chromium/v8/src/compiler/raw-machine-assembler.cc
@@ -747,7 +747,8 @@ Node* CallCFunctionImpl(
   }
   for (const auto& arg : args) builder.AddParam(arg.first);
 
-  bool caller_saved_fp_regs = caller_saved_regs && (mode == kSaveFPRegs);
+  bool caller_saved_fp_regs =
+      caller_saved_regs && (mode == SaveFPRegsMode::kSave);
   CallDescriptor::Flags flags = CallDescriptor::kNoFlags;
   if (caller_saved_regs) flags |= CallDescriptor::kCallerSavedRegisters;
   if (caller_saved_fp_regs) flags |= CallDescriptor::kCallerSavedFPRegisters;
@@ -772,14 +773,14 @@ Node* RawMachineAssembler::CallCFunction(
     Node* function, base::Optional<MachineType> return_type,
     std::initializer_list<RawMachineAssembler::CFunctionArg> args) {
   return CallCFunctionImpl(this, function, return_type, args, false,
-                           kDontSaveFPRegs, kHasFunctionDescriptor);
+                           SaveFPRegsMode::kIgnore, kHasFunctionDescriptor);
 }
 
 Node* RawMachineAssembler::CallCFunctionWithoutFunctionDescriptor(
     Node* function, MachineType return_type,
     std::initializer_list<RawMachineAssembler::CFunctionArg> args) {
   return CallCFunctionImpl(this, function, return_type, args, false,
-                           kDontSaveFPRegs, kNoFunctionDescriptor);
+                           SaveFPRegsMode::kIgnore, kNoFunctionDescriptor);
 }
 
 Node* RawMachineAssembler::CallCFunctionWithCallerSavedRegisters(
diff --git a/chromium/v8/src/compiler/raw-machine-assembler.h b/chromium/v8/src/compiler/raw-machine-assembler.h
index 1dff0a7c0c0..a811fa7bf9c 100644
--- a/chromium/v8/src/compiler/raw-machine-assembler.h
+++ b/chromium/v8/src/compiler/raw-machine-assembler.h
@@ -15,6 +15,7 @@
 #include "src/compiler/graph.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/machine-operator.h"
+#include "src/compiler/node-matchers.h"
 #include "src/compiler/node.h"
 #include "src/compiler/operator.h"
 #include "src/compiler/simplified-operator.h"
@@ -147,10 +148,38 @@ class V8_EXPORT_PRIVATE RawMachineAssembler {
     Node* load = AddNode(op, base, index);
     return load;
   }
+  Node* LoadImmutable(MachineType type, Node* base) {
+    return LoadImmutable(type, base, IntPtrConstant(0));
+  }
+  Node* LoadImmutable(MachineType type, Node* base, Node* index) {
+    const Operator* op = machine()->LoadImmutable(type);
+    return AddNode(op, base, index);
+  }
+  bool IsMapOffsetConstant(Node* node) {
+    Int64Matcher m(node);
+    if (m.Is(HeapObject::kMapOffset)) return true;
+    // Test if `node` is a `Phi(Int64Constant(0))`
+    if (node->opcode() == IrOpcode::kPhi) {
+      for (Node* input : node->inputs()) {
+        if (!Int64Matcher(input).Is(HeapObject::kMapOffset)) return false;
+      }
+      return true;
+    }
+    return false;
+  }
+  bool IsMapOffsetConstantMinusTag(Node* node) {
+    Int64Matcher m(node);
+    return m.Is(HeapObject::kMapOffset - kHeapObjectTag);
+  }
+  bool IsMapOffsetConstantMinusTag(int offset) {
+    return offset == HeapObject::kMapOffset - kHeapObjectTag;
+  }
   Node* LoadFromObject(
       MachineType type, Node* base, Node* offset,
       LoadSensitivity needs_poisoning = LoadSensitivity::kSafe) {
     CHECK_EQ(needs_poisoning, LoadSensitivity::kSafe);
+    DCHECK_IMPLIES(V8_MAP_PACKING_BOOL && IsMapOffsetConstantMinusTag(offset),
+                   type == MachineType::MapInHeader());
     ObjectAccess access = {type, WriteBarrierKind::kNoWriteBarrier};
     Node* load = AddNode(simplified()->LoadFromObject(access), base, offset);
     return load;
@@ -169,18 +198,22 @@ class V8_EXPORT_PRIVATE RawMachineAssembler {
                      Node* value, WriteBarrierKind write_barrier) {
     ObjectAccess access = {MachineType::TypeForRepresentation(rep),
                            write_barrier};
+    DCHECK(!IsMapOffsetConstantMinusTag(offset));
     AddNode(simplified()->StoreToObject(access), object, offset, value);
   }
   void OptimizedStoreField(MachineRepresentation rep, Node* object, int offset,
                            Node* value, WriteBarrierKind write_barrier) {
+    DCHECK(!IsMapOffsetConstantMinusTag(offset));
     AddNode(simplified()->StoreField(FieldAccess(
                 BaseTaggedness::kTaggedBase, offset, MaybeHandle<Name>(),
                 MaybeHandle<Map>(), Type::Any(),
                 MachineType::TypeForRepresentation(rep), write_barrier)),
             object, value);
   }
-  void OptimizedStoreMap(Node* object, Node* value) {
-    AddNode(simplified()->StoreField(AccessBuilder::ForMap()), object, value);
+  void OptimizedStoreMap(Node* object, Node* value,
+                         WriteBarrierKind write_barrier = kMapWriteBarrier) {
+    AddNode(simplified()->StoreField(AccessBuilder::ForMap(write_barrier)),
+            object, value);
   }
   Node* Retain(Node* value) { return AddNode(common()->Retain(), value); }
 
@@ -245,6 +278,7 @@ class V8_EXPORT_PRIVATE RawMachineAssembler {
 
   Node* AtomicStore(MachineRepresentation rep, Node* base, Node* index,
                     Node* value) {
+    DCHECK(!IsMapOffsetConstantMinusTag(index));
     DCHECK_NE(rep, MachineRepresentation::kWord64);
     return AddNode(machine()->Word32AtomicStore(rep), base, index, value);
   }
@@ -547,6 +581,15 @@ class V8_EXPORT_PRIVATE RawMachineAssembler {
   }
   Node* Word32Ctz(Node* a) { return AddNode(machine()->Word32Ctz().op(), a); }
   Node* Word64Ctz(Node* a) { return AddNode(machine()->Word64Ctz().op(), a); }
+
+  Node* Word32Select(Node* condition, Node* b, Node* c) {
+    return AddNode(machine()->Word32Select().op(), condition, b, c);
+  }
+
+  Node* Word64Select(Node* condition, Node* b, Node* c) {
+    return AddNode(machine()->Word64Select().op(), condition, b, c);
+  }
+
   Node* StackPointerGreaterThan(Node* value) {
     return AddNode(
         machine()->StackPointerGreaterThan(StackCheckKind::kCodeStubAssembler),
diff --git a/chromium/v8/src/compiler/refs-map.cc b/chromium/v8/src/compiler/refs-map.cc
index 7cf465f00bc..149865b0933 100644
--- a/chromium/v8/src/compiler/refs-map.cc
+++ b/chromium/v8/src/compiler/refs-map.cc
@@ -27,6 +27,10 @@ RefsMap::Entry* RefsMap::LookupOrInsert(const Address& key) {
                                        []() { return nullptr; });
 }
 
+ObjectData* RefsMap::Remove(const Address& key) {
+  return UnderlyingMap::Remove(key, RefsMap::Hash(key));
+}
+
 uint32_t RefsMap::Hash(Address addr) { return static_cast<uint32_t>(addr); }
 
 }  // namespace compiler
diff --git a/chromium/v8/src/compiler/refs-map.h b/chromium/v8/src/compiler/refs-map.h
index 708da8359f9..3b26276072d 100644
--- a/chromium/v8/src/compiler/refs-map.h
+++ b/chromium/v8/src/compiler/refs-map.h
@@ -42,6 +42,7 @@ class RefsMap
   // Wrappers around methods from UnderlyingMap
   Entry* Lookup(const Address& key) const;
   Entry* LookupOrInsert(const Address& key);
+  ObjectData* Remove(const Address& key);
 
  private:
   static uint32_t Hash(Address addr);
diff --git a/chromium/v8/src/compiler/representation-change.cc b/chromium/v8/src/compiler/representation-change.cc
index 4bfaa1cceea..750bc1fd563 100644
--- a/chromium/v8/src/compiler/representation-change.cc
+++ b/chromium/v8/src/compiler/representation-change.cc
@@ -237,6 +237,7 @@ Node* RepresentationChanger::GetRepresentationFor(
       return node;
     case MachineRepresentation::kCompressed:
     case MachineRepresentation::kCompressedPointer:
+    case MachineRepresentation::kMapWord:
       UNREACHABLE();
   }
   UNREACHABLE();
@@ -510,7 +511,8 @@ Node* RepresentationChanger::GetTaggedRepresentationFor(
       break;
   }
   if (output_rep == MachineRepresentation::kTaggedSigned ||
-      output_rep == MachineRepresentation::kTaggedPointer) {
+      output_rep == MachineRepresentation::kTaggedPointer ||
+      output_rep == MachineRepresentation::kMapWord) {
     // this is a no-op.
     return node;
   }
@@ -795,12 +797,12 @@ Node* RepresentationChanger::MakeTruncatedInt32Constant(double value) {
   return jsgraph()->Int32Constant(DoubleToInt32(value));
 }
 
-Node* RepresentationChanger::InsertUnconditionalDeopt(Node* node,
-                                                      DeoptimizeReason reason) {
+Node* RepresentationChanger::InsertUnconditionalDeopt(
+    Node* node, DeoptimizeReason reason, const FeedbackSource& feedback) {
   Node* effect = NodeProperties::GetEffectInput(node);
   Node* control = NodeProperties::GetControlInput(node);
   effect =
-      jsgraph()->graph()->NewNode(simplified()->CheckIf(reason),
+      jsgraph()->graph()->NewNode(simplified()->CheckIf(reason, feedback),
                                   jsgraph()->Int32Constant(0), effect, control);
   Node* unreachable = effect = jsgraph()->graph()->NewNode(
       jsgraph()->common()->Unreachable(), effect, control);
@@ -1102,7 +1104,7 @@ Node* RepresentationChanger::GetWord64RepresentationFor(
       HeapObjectMatcher m(node);
       if (m.HasResolvedValue() && m.Ref(broker_).IsBigInt() &&
           use_info.truncation().IsUsedAsWord64()) {
-        auto bigint = m.Ref(broker_).AsBigInt();
+        BigIntRef bigint = m.Ref(broker_).AsBigInt();
         return jsgraph()->Int64Constant(
             static_cast<int64_t>(bigint.AsUint64()));
       }
@@ -1117,8 +1119,8 @@ Node* RepresentationChanger::GetWord64RepresentationFor(
     if (!CanBeTaggedPointer(output_rep) &&
         output_rep != MachineRepresentation::kWord64) {
       DCHECK(!output_type.Equals(Type::BigInt()));
-      Node* unreachable =
-          InsertUnconditionalDeopt(use_node, DeoptimizeReason::kNotABigInt);
+      Node* unreachable = InsertUnconditionalDeopt(
+          use_node, DeoptimizeReason::kNotABigInt, use_info.feedback());
       return jsgraph()->graph()->NewNode(
           jsgraph()->common()->DeadValue(MachineRepresentation::kWord64),
           unreachable);
@@ -1157,11 +1159,11 @@ Node* RepresentationChanger::GetWord64RepresentationFor(
                        MachineRepresentation::kWord64);
     }
   } else if (output_rep == MachineRepresentation::kFloat32) {
-    if (output_type.Is(cache_->kInt64)) {
+    if (output_type.Is(cache_->kDoubleRepresentableInt64)) {
       // float32 -> float64 -> int64
       node = InsertChangeFloat32ToFloat64(node);
       op = machine()->ChangeFloat64ToInt64();
-    } else if (output_type.Is(cache_->kUint64)) {
+    } else if (output_type.Is(cache_->kDoubleRepresentableUint64)) {
       // float32 -> float64 -> uint64
       node = InsertChangeFloat32ToFloat64(node);
       op = machine()->ChangeFloat64ToUint64();
@@ -1179,9 +1181,9 @@ Node* RepresentationChanger::GetWord64RepresentationFor(
                        MachineRepresentation::kWord64);
     }
   } else if (output_rep == MachineRepresentation::kFloat64) {
-    if (output_type.Is(cache_->kInt64)) {
+    if (output_type.Is(cache_->kDoubleRepresentableInt64)) {
       op = machine()->ChangeFloat64ToInt64();
-    } else if (output_type.Is(cache_->kUint64)) {
+    } else if (output_type.Is(cache_->kDoubleRepresentableUint64)) {
       op = machine()->ChangeFloat64ToUint64();
     } else if (use_info.type_check() == TypeCheckKind::kSigned64 ||
                use_info.type_check() == TypeCheckKind::kArrayIndex) {
@@ -1209,7 +1211,7 @@ Node* RepresentationChanger::GetWord64RepresentationFor(
                                              use_node, use_info);
     op = simplified()->TruncateBigIntToUint64();
   } else if (CanBeTaggedPointer(output_rep)) {
-    if (output_type.Is(cache_->kInt64)) {
+    if (output_type.Is(cache_->kDoubleRepresentableInt64)) {
       op = simplified()->ChangeTaggedToInt64();
     } else if (use_info.type_check() == TypeCheckKind::kSigned64) {
       op = simplified()->CheckedTaggedToInt64(
@@ -1228,8 +1230,11 @@ Node* RepresentationChanger::GetWord64RepresentationFor(
     if (output_type.Is(Type::BigInt())) {
       return node;
     } else {
-      return TypeError(node, output_rep, output_type,
-                       MachineRepresentation::kWord64);
+      Node* unreachable = InsertUnconditionalDeopt(
+          use_node, DeoptimizeReason::kNotABigInt, use_info.feedback());
+      return jsgraph()->graph()->NewNode(
+          jsgraph()->common()->DeadValue(MachineRepresentation::kWord64),
+          unreachable);
     }
   } else {
     return TypeError(node, output_rep, output_type,
diff --git a/chromium/v8/src/compiler/representation-change.h b/chromium/v8/src/compiler/representation-change.h
index 334237ed1fa..a4b05cbfe79 100644
--- a/chromium/v8/src/compiler/representation-change.h
+++ b/chromium/v8/src/compiler/representation-change.h
@@ -16,7 +16,7 @@ namespace compiler {
 // Foward declarations.
 class TypeCache;
 
-enum IdentifyZeros { kIdentifyZeros, kDistinguishZeros };
+enum IdentifyZeros : uint8_t { kIdentifyZeros, kDistinguishZeros };
 
 class Truncation final {
  public:
@@ -180,10 +180,10 @@ class UseInfo {
   static UseInfo TruncatingWord32() {
     return UseInfo(MachineRepresentation::kWord32, Truncation::Word32());
   }
-  static UseInfo TruncatingWord64() {
-    return UseInfo(MachineRepresentation::kWord64, Truncation::Word64());
-  }
   static UseInfo CheckedBigIntTruncatingWord64(const FeedbackSource& feedback) {
+    // Note that Trunction::Word64() can safely use kIdentifyZero, because
+    // TypeCheckKind::kBigInt will make sure we deopt for anything other than
+    // type BigInt anyway.
     return UseInfo(MachineRepresentation::kWord64, Truncation::Word64(),
                    TypeCheckKind::kBigInt, feedback);
   }
@@ -400,7 +400,8 @@ class V8_EXPORT_PRIVATE RepresentationChanger final {
                                     Node* use_node);
   Node* InsertConversion(Node* node, const Operator* op, Node* use_node);
   Node* InsertTruncateInt64ToInt32(Node* node);
-  Node* InsertUnconditionalDeopt(Node* node, DeoptimizeReason reason);
+  Node* InsertUnconditionalDeopt(Node* node, DeoptimizeReason reason,
+                                 const FeedbackSource& feedback = {});
 
   JSGraph* jsgraph() const { return jsgraph_; }
   Isolate* isolate() const;
diff --git a/chromium/v8/src/compiler/scheduled-machine-lowering.cc b/chromium/v8/src/compiler/scheduled-machine-lowering.cc
deleted file mode 100644
index fde836e4e83..00000000000
--- a/chromium/v8/src/compiler/scheduled-machine-lowering.cc
+++ /dev/null
@@ -1,68 +0,0 @@
-// Copyright 2019 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "src/compiler/scheduled-machine-lowering.h"
-
-#include "src/compiler/compiler-source-position-table.h"
-#include "src/compiler/js-graph.h"
-#include "src/compiler/node-origin-table.h"
-#include "src/compiler/node-properties.h"
-#include "src/compiler/schedule.h"
-
-namespace v8 {
-namespace internal {
-namespace compiler {
-
-ScheduledMachineLowering::ScheduledMachineLowering(
-    JSGraph* js_graph, Schedule* schedule, Zone* temp_zone,
-    SourcePositionTable* source_positions, NodeOriginTable* node_origins,
-    PoisoningMitigationLevel poison_level)
-    : schedule_(schedule),
-      graph_assembler_(js_graph, temp_zone, base::nullopt, schedule),
-      select_lowering_(&graph_assembler_, js_graph->graph()),
-      memory_lowering_(js_graph, temp_zone, &graph_assembler_, poison_level),
-      reducers_({&select_lowering_, &memory_lowering_}, temp_zone),
-      source_positions_(source_positions),
-      node_origins_(node_origins) {}
-
-void ScheduledMachineLowering::Run() {
-  // TODO(rmcilroy) We should not depend on having rpo_order on schedule, and
-  // instead just do our own RPO walk here.
-  for (BasicBlock* block : *(schedule()->rpo_order())) {
-    BasicBlock::iterator instr = block->begin();
-    BasicBlock::iterator end_instr = block->end();
-    gasm()->Reset(block);
-
-    for (; instr != end_instr; instr++) {
-      Node* node = *instr;
-      Reduction reduction;
-      for (auto reducer : reducers_) {
-        reduction = reducer->Reduce(node, nullptr);
-        if (reduction.Changed()) break;
-      }
-      if (reduction.Changed()) {
-        Node* replacement = reduction.replacement();
-        if (replacement != node) {
-          // Replace all uses of node and kill the node to make sure we don't
-          // leave dangling dead uses.
-          NodeProperties::ReplaceUses(node, replacement, gasm()->effect(),
-                                      gasm()->control());
-          node->Kill();
-        } else {
-          gasm()->AddNode(replacement);
-        }
-      } else {
-        gasm()->AddNode(node);
-      }
-    }
-
-    gasm()->FinalizeCurrentBlock(block);
-  }
-
-  schedule_->rpo_order()->clear();
-}
-
-}  // namespace compiler
-}  // namespace internal
-}  // namespace v8
diff --git a/chromium/v8/src/compiler/scheduled-machine-lowering.h b/chromium/v8/src/compiler/scheduled-machine-lowering.h
deleted file mode 100644
index ca078a2a534..00000000000
--- a/chromium/v8/src/compiler/scheduled-machine-lowering.h
+++ /dev/null
@@ -1,51 +0,0 @@
-// Copyright 2019 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef V8_COMPILER_SCHEDULED_MACHINE_LOWERING_H_
-#define V8_COMPILER_SCHEDULED_MACHINE_LOWERING_H_
-
-#include "src/compiler/graph-assembler.h"
-#include "src/compiler/memory-lowering.h"
-#include "src/compiler/select-lowering.h"
-
-namespace v8 {
-namespace internal {
-namespace compiler {
-
-class NodeOriginTable;
-class Schedule;
-class SourcePositionTable;
-
-// Performs machine lowering on an already scheduled graph.
-class ScheduledMachineLowering final {
- public:
-  ScheduledMachineLowering(JSGraph* js_graph, Schedule* schedule,
-                           Zone* temp_zone,
-                           SourcePositionTable* source_positions,
-                           NodeOriginTable* node_origins,
-                           PoisoningMitigationLevel poison_level);
-  ~ScheduledMachineLowering() = default;
-
-  void Run();
-
- private:
-  bool LowerNode(Node* node);
-
-  JSGraphAssembler* gasm() { return &graph_assembler_; }
-  Schedule* schedule() { return schedule_; }
-
-  Schedule* schedule_;
-  JSGraphAssembler graph_assembler_;
-  SelectLowering select_lowering_;
-  MemoryLowering memory_lowering_;
-  ZoneVector<Reducer*> reducers_;
-  SourcePositionTable* source_positions_;
-  NodeOriginTable* node_origins_;
-};
-
-}  // namespace compiler
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_COMPILER_SCHEDULED_MACHINE_LOWERING_H_
diff --git a/chromium/v8/src/compiler/scheduler.cc b/chromium/v8/src/compiler/scheduler.cc
index fdfa16052b4..07a716bfa7a 100644
--- a/chromium/v8/src/compiler/scheduler.cc
+++ b/chromium/v8/src/compiler/scheduler.cc
@@ -105,15 +105,8 @@ Scheduler::Placement Scheduler::InitializePlacement(Node* node) {
       data->placement_ = (p == kFixed ? kFixed : kCoupled);
       break;
     }
-#define DEFINE_CONTROL_CASE(V) case IrOpcode::k##V:
-      CONTROL_OP_LIST(DEFINE_CONTROL_CASE)
-#undef DEFINE_CONTROL_CASE
-      {
-        // Control nodes that were not control-reachable from end may float.
-        data->placement_ = kSchedulable;
-        break;
-    }
     default:
+      // Control nodes that were not control-reachable from end may float.
       data->placement_ = kSchedulable;
       break;
   }
@@ -172,31 +165,32 @@ void Scheduler::UpdatePlacement(Node* node, Placement placement) {
   // Reduce the use count of the node's inputs to potentially make them
   // schedulable. If all the uses of a node have been scheduled, then the node
   // itself can be scheduled.
+  base::Optional<int> coupled_control_edge = GetCoupledControlEdge(node);
   for (Edge const edge : node->input_edges()) {
-    DecrementUnscheduledUseCount(edge.to(), edge.index(), edge.from());
+    DCHECK_EQ(node, edge.from());
+    if (edge.index() != coupled_control_edge) {
+      DecrementUnscheduledUseCount(edge.to(), node);
+    }
   }
   data->placement_ = placement;
 }
 
-
-bool Scheduler::IsCoupledControlEdge(Node* node, int index) {
-  return GetPlacement(node) == kCoupled &&
-         NodeProperties::FirstControlIndex(node) == index;
+base::Optional<int> Scheduler::GetCoupledControlEdge(Node* node) {
+  if (GetPlacement(node) == kCoupled) {
+    return NodeProperties::FirstControlIndex(node);
+  }
+  return {};
 }
 
-
-void Scheduler::IncrementUnscheduledUseCount(Node* node, int index,
-                                             Node* from) {
-  // Make sure that control edges from coupled nodes are not counted.
-  if (IsCoupledControlEdge(from, index)) return;
-
+void Scheduler::IncrementUnscheduledUseCount(Node* node, Node* from) {
   // Tracking use counts for fixed nodes is useless.
   if (GetPlacement(node) == kFixed) return;
 
   // Use count for coupled nodes is summed up on their control.
   if (GetPlacement(node) == kCoupled) {
-    Node* control = NodeProperties::GetControlInput(node);
-    return IncrementUnscheduledUseCount(control, index, from);
+    node = NodeProperties::GetControlInput(node);
+    DCHECK_NE(GetPlacement(node), Placement::kFixed);
+    DCHECK_NE(GetPlacement(node), Placement::kCoupled);
   }
 
   ++(GetData(node)->unscheduled_count_);
@@ -207,19 +201,15 @@ void Scheduler::IncrementUnscheduledUseCount(Node* node, int index,
   }
 }
 
-
-void Scheduler::DecrementUnscheduledUseCount(Node* node, int index,
-                                             Node* from) {
-  // Make sure that control edges from coupled nodes are not counted.
-  if (IsCoupledControlEdge(from, index)) return;
-
+void Scheduler::DecrementUnscheduledUseCount(Node* node, Node* from) {
   // Tracking use counts for fixed nodes is useless.
   if (GetPlacement(node) == kFixed) return;
 
   // Use count for coupled nodes is summed up on their control.
   if (GetPlacement(node) == kCoupled) {
-    Node* control = NodeProperties::GetControlInput(node);
-    return DecrementUnscheduledUseCount(control, index, from);
+    node = NodeProperties::GetControlInput(node);
+    DCHECK_NE(GetPlacement(node), Placement::kFixed);
+    DCHECK_NE(GetPlacement(node), Placement::kCoupled);
   }
 
   DCHECK_LT(0, GetData(node)->unscheduled_count_);
@@ -235,7 +225,6 @@ void Scheduler::DecrementUnscheduledUseCount(Node* node, int index,
   }
 }
 
-
 // -----------------------------------------------------------------------------
 // Phase 1: Build control-flow graph.
 
@@ -738,6 +727,8 @@ class SpecialRPONumberer : public ZoneObject {
     return empty_;
   }
 
+  bool HasLoopBlocks() const { return loops_.size() != 0; }
+
  private:
   using Backedge = std::pair<BasicBlock*, size_t>;
 
@@ -1221,10 +1212,26 @@ void Scheduler::GenerateDominatorTree() {
 
 class PrepareUsesVisitor {
  public:
-  explicit PrepareUsesVisitor(Scheduler* scheduler)
-      : scheduler_(scheduler), schedule_(scheduler->schedule_) {}
+  explicit PrepareUsesVisitor(Scheduler* scheduler, Graph* graph, Zone* zone)
+      : scheduler_(scheduler),
+        schedule_(scheduler->schedule_),
+        graph_(graph),
+        visited_(graph_->NodeCount(), false, zone),
+        stack_(zone) {}
+
+  void Run() {
+    InitializePlacement(graph_->end());
+    while (!stack_.empty()) {
+      Node* node = stack_.top();
+      stack_.pop();
+      VisitInputs(node);
+    }
+  }
 
-  void Pre(Node* node) {
+ private:
+  void InitializePlacement(Node* node) {
+    TRACE("Pre #%d:%s\n", node->id(), node->op()->mnemonic());
+    DCHECK(!Visited(node));
     if (scheduler_->InitializePlacement(node) == Scheduler::kFixed) {
       // Fixed nodes are always roots for schedule late.
       scheduler_->schedule_root_nodes_.push_back(node);
@@ -1241,21 +1248,37 @@ class PrepareUsesVisitor {
         schedule_->AddNode(block, node);
       }
     }
+    stack_.push(node);
+    visited_[node->id()] = true;
   }
 
-  void PostEdge(Node* from, int index, Node* to) {
-    // If the edge is from an unscheduled node, then tally it in the use count
-    // for all of its inputs. The same criterion will be used in ScheduleLate
-    // for decrementing use counts.
-    if (!schedule_->IsScheduled(from)) {
-      DCHECK_NE(Scheduler::kFixed, scheduler_->GetPlacement(from));
-      scheduler_->IncrementUnscheduledUseCount(to, index, from);
+  void VisitInputs(Node* node) {
+    DCHECK_NE(scheduler_->GetPlacement(node), Scheduler::kUnknown);
+    bool is_scheduled = schedule_->IsScheduled(node);
+    base::Optional<int> coupled_control_edge =
+        scheduler_->GetCoupledControlEdge(node);
+    for (auto edge : node->input_edges()) {
+      Node* to = edge.to();
+      DCHECK_EQ(node, edge.from());
+      if (!Visited(to)) {
+        InitializePlacement(to);
+      }
+      TRACE("PostEdge #%d:%s->#%d:%s\n", node->id(), node->op()->mnemonic(),
+            to->id(), to->op()->mnemonic());
+      DCHECK_NE(scheduler_->GetPlacement(to), Scheduler::kUnknown);
+      if (!is_scheduled && edge.index() != coupled_control_edge) {
+        scheduler_->IncrementUnscheduledUseCount(to, node);
+      }
     }
   }
 
- private:
+  bool Visited(Node* node) { return visited_[node->id()]; }
+
   Scheduler* scheduler_;
   Schedule* schedule_;
+  Graph* graph_;
+  BoolVector visited_;
+  ZoneStack<Node*> stack_;
 };
 
 
@@ -1264,28 +1287,8 @@ void Scheduler::PrepareUses() {
 
   // Count the uses of every node, which is used to ensure that all of a
   // node's uses are scheduled before the node itself.
-  PrepareUsesVisitor prepare_uses(this);
-
-  // TODO(turbofan): simplify the careful pre/post ordering here.
-  BoolVector visited(graph_->NodeCount(), false, zone_);
-  ZoneStack<Node::InputEdges::iterator> stack(zone_);
-  Node* node = graph_->end();
-  prepare_uses.Pre(node);
-  visited[node->id()] = true;
-  stack.push(node->input_edges().begin());
-  while (!stack.empty()) {
-    tick_counter_->TickAndMaybeEnterSafepoint();
-    Edge edge = *stack.top();
-    Node* node = edge.to();
-    if (visited[node->id()]) {
-      prepare_uses.PostEdge(edge.from(), edge.index(), edge.to());
-      if (++stack.top() == edge.from()->input_edges().end()) stack.pop();
-    } else {
-      prepare_uses.Pre(node);
-      visited[node->id()] = true;
-      if (node->InputCount() > 0) stack.push(node->input_edges().begin());
-    }
-  }
+  PrepareUsesVisitor prepare_uses(this, graph_, zone_);
+  prepare_uses.Run();
 }
 
 
@@ -1302,11 +1305,12 @@ class ScheduleEarlyNodeVisitor {
   void Run(NodeVector* roots) {
     for (Node* const root : *roots) {
       queue_.push(root);
-      while (!queue_.empty()) {
-        scheduler_->tick_counter_->TickAndMaybeEnterSafepoint();
-        VisitNode(queue_.front());
-        queue_.pop();
-      }
+    }
+
+    while (!queue_.empty()) {
+      scheduler_->tick_counter_->TickAndMaybeEnterSafepoint();
+      VisitNode(queue_.front());
+      queue_.pop();
     }
   }
 
@@ -1380,6 +1384,11 @@ class ScheduleEarlyNodeVisitor {
 
 
 void Scheduler::ScheduleEarly() {
+  if (!special_rpo_->HasLoopBlocks()) {
+    TRACE("--- NO LOOPS SO SKIPPING SCHEDULE EARLY --------------------\n");
+    return;
+  }
+
   TRACE("--- SCHEDULE EARLY -----------------------------------------\n");
   if (FLAG_trace_turbo_scheduler) {
     TRACE("roots: ");
@@ -1457,6 +1466,7 @@ class ScheduleLateNodeVisitor {
     // The schedule early block dominates the schedule late block.
     BasicBlock* min_block = scheduler_->GetData(node)->minimum_block_;
     DCHECK_EQ(min_block, BasicBlock::GetCommonDominator(block, min_block));
+
     TRACE(
         "Schedule late of #%d:%s is id:%d at loop depth %d, minimum = id:%d\n",
         node->id(), node->op()->mnemonic(), block->id().ToInt(),
@@ -1468,6 +1478,7 @@ class ScheduleLateNodeVisitor {
     BasicBlock* hoist_block = GetHoistBlock(block);
     if (hoist_block &&
         hoist_block->dominator_depth() >= min_block->dominator_depth()) {
+      DCHECK(scheduler_->special_rpo_->HasLoopBlocks());
       do {
         TRACE("  hoisting #%d:%s to block id:%d\n", node->id(),
               node->op()->mnemonic(), hoist_block->id().ToInt());
@@ -1597,6 +1608,7 @@ class ScheduleLateNodeVisitor {
   }
 
   BasicBlock* GetHoistBlock(BasicBlock* block) {
+    if (!scheduler_->special_rpo_->HasLoopBlocks()) return nullptr;
     if (block->IsLoopHeader()) return block->dominator();
     // We have to check to make sure that the {block} dominates all
     // of the outgoing blocks.  If it doesn't, then there is a path
@@ -1717,9 +1729,13 @@ class ScheduleLateNodeVisitor {
 
   Node* CloneNode(Node* node) {
     int const input_count = node->InputCount();
+    base::Optional<int> coupled_control_edge =
+        scheduler_->GetCoupledControlEdge(node);
     for (int index = 0; index < input_count; ++index) {
-      Node* const input = node->InputAt(index);
-      scheduler_->IncrementUnscheduledUseCount(input, index, node);
+      if (index != coupled_control_edge) {
+        Node* const input = node->InputAt(index);
+        scheduler_->IncrementUnscheduledUseCount(input, node);
+      }
     }
     Node* const copy = scheduler_->graph_->CloneNode(node);
     TRACE(("clone #%d:%s -> #%d\n"), node->id(), node->op()->mnemonic(),
diff --git a/chromium/v8/src/compiler/scheduler.h b/chromium/v8/src/compiler/scheduler.h
index d8934ec1572..9d9fd6aed0d 100644
--- a/chromium/v8/src/compiler/scheduler.h
+++ b/chromium/v8/src/compiler/scheduler.h
@@ -103,9 +103,10 @@ class V8_EXPORT_PRIVATE Scheduler {
   void UpdatePlacement(Node* node, Placement placement);
   bool IsLive(Node* node);
 
-  inline bool IsCoupledControlEdge(Node* node, int index);
-  void IncrementUnscheduledUseCount(Node* node, int index, Node* from);
-  void DecrementUnscheduledUseCount(Node* node, int index, Node* from);
+  // If the node is coupled, returns the coupled control edge index.
+  inline base::Optional<int> GetCoupledControlEdge(Node* node);
+  void IncrementUnscheduledUseCount(Node* node, Node* from);
+  void DecrementUnscheduledUseCount(Node* node, Node* from);
 
   static void PropagateImmediateDominators(BasicBlock* block);
 
diff --git a/chromium/v8/src/compiler/select-lowering.cc b/chromium/v8/src/compiler/select-lowering.cc
index 590df6ae1f0..e346e9171d7 100644
--- a/chromium/v8/src/compiler/select-lowering.cc
+++ b/chromium/v8/src/compiler/select-lowering.cc
@@ -34,7 +34,11 @@ Reduction SelectLowering::LowerSelect(Node* node) {
   Node* vtrue = node->InputAt(1);
   Node* vfalse = node->InputAt(2);
 
-  gasm()->InitializeEffectControl(start(), start());
+  bool reset_gasm = false;
+  if (gasm()->control() == nullptr) {
+    gasm()->InitializeEffectControl(start(), start());
+    reset_gasm = true;
+  }
 
   auto done = __ MakeLabel(p.representation());
 
@@ -42,6 +46,10 @@ Reduction SelectLowering::LowerSelect(Node* node) {
   __ Goto(&done, vfalse);
   __ Bind(&done);
 
+  if (reset_gasm) {
+    gasm()->Reset(nullptr);
+  }
+
   return Changed(done.PhiAt(0));
 }
 
diff --git a/chromium/v8/src/compiler/serializer-for-background-compilation.cc b/chromium/v8/src/compiler/serializer-for-background-compilation.cc
index ad6879a02dd..893d12f1e9c 100644
--- a/chromium/v8/src/compiler/serializer-for-background-compilation.cc
+++ b/chromium/v8/src/compiler/serializer-for-background-compilation.cc
@@ -21,6 +21,7 @@
 #include "src/objects/js-regexp-inl.h"
 #include "src/objects/literal-objects-inl.h"
 #include "src/objects/shared-function-info-inl.h"
+#include "src/objects/template-objects-inl.h"
 #include "src/zone/zone-containers.h"
 #include "src/zone/zone.h"
 
@@ -1071,8 +1072,9 @@ SerializerForBackgroundCompilation::SerializerForBackgroundCompilation(
           CompilationSubject(closure, broker_->isolate(), zone()))),
       arguments_(zone()) {
   closure_hints_.AddConstant(closure, zone(), broker_);
-  JSFunctionRef(broker, closure).Serialize();
-  JSFunctionRef(broker, closure).SerializeCodeAndFeedback();
+  JSFunctionRef closure_ref = MakeRef(broker, closure);
+  closure_ref.Serialize();
+  closure_ref.SerializeCodeAndFeedback();
 
   TRACE_BROKER(broker_, "Hints for <closure>: " << closure_hints_);
   TRACE_BROKER(broker_, "Initial environment:\n" << *environment_);
@@ -1099,8 +1101,9 @@ SerializerForBackgroundCompilation::SerializerForBackgroundCompilation(
   Handle<JSFunction> closure;
   if (function.closure().ToHandle(&closure)) {
     closure_hints_.AddConstant(closure, zone(), broker);
-    JSFunctionRef(broker, closure).Serialize();
-    JSFunctionRef(broker, closure).SerializeCodeAndFeedback();
+    JSFunctionRef closure_ref = MakeRef(broker, closure);
+    closure_ref.Serialize();
+    closure_ref.SerializeCodeAndFeedback();
   } else {
     closure_hints_.AddVirtualClosure(function.virtual_closure(), zone(),
                                      broker);
@@ -1145,8 +1148,8 @@ Hints SerializerForBackgroundCompilation::Run() {
 
   TRACE_BROKER_MEMORY(broker(), "[serializer start] Broker zone usage: "
                                     << broker()->zone()->allocation_size());
-  SharedFunctionInfoRef shared(broker(), function().shared());
-  FeedbackVectorRef feedback_vector_ref(broker(), feedback_vector());
+  SharedFunctionInfoRef shared = MakeRef(broker(), function().shared());
+  FeedbackVectorRef feedback_vector_ref = MakeRef(broker(), feedback_vector());
   if (!broker()->ShouldBeSerializedForCompilation(shared, feedback_vector_ref,
                                                   arguments_)) {
     TRACE_BROKER(broker(),
@@ -1342,7 +1345,7 @@ void SerializerForBackgroundCompilation::VisitGetIterator(
   FeedbackSlot call_slot = iterator->GetSlotOperand(2);
 
   Handle<Name> name = broker()->isolate()->factory()->iterator_symbol();
-  ProcessNamedPropertyAccess(receiver, NameRef(broker(), name), load_slot,
+  ProcessNamedPropertyAccess(receiver, MakeRef(broker(), name), load_slot,
                              AccessMode::kLoad);
   if (environment()->IsDead()) return;
 
@@ -1360,10 +1363,10 @@ void SerializerForBackgroundCompilation::VisitGetSuperConstructor(
   for (auto constant : environment()->accumulator_hints().constants()) {
     // For JSNativeContextSpecialization::ReduceJSGetSuperConstructor.
     if (!constant->IsJSFunction()) continue;
-    MapRef map(broker(),
-               handle(HeapObject::cast(*constant).map(), broker()->isolate()));
+    MapRef map = MakeRef(broker(), handle(HeapObject::cast(*constant).map(),
+                                          broker()->isolate()));
     map.SerializePrototype();
-    ObjectRef proto = map.prototype();
+    ObjectRef proto = map.prototype().value();
     if (proto.IsHeapObject() && proto.AsHeapObject().map().is_constructor()) {
       result_hints.AddConstant(proto.object(), zone(), broker());
     }
@@ -1373,8 +1376,9 @@ void SerializerForBackgroundCompilation::VisitGetSuperConstructor(
 
 void SerializerForBackgroundCompilation::VisitGetTemplateObject(
     BytecodeArrayIterator* iterator) {
-  TemplateObjectDescriptionRef description(
-      broker(), iterator->GetConstantForIndexOperand(0, broker()->isolate()));
+  MakeRef(broker(),
+          Handle<TemplateObjectDescription>::cast(
+              iterator->GetConstantForIndexOperand(0, broker()->isolate())));
   FeedbackSlot slot = iterator->GetSlotOperand(1);
   FeedbackSource source(feedback_vector(), slot);
 
@@ -1511,12 +1515,12 @@ void SerializerForBackgroundCompilation::VisitInvokeIntrinsic(
     case Runtime::kInlineGetImportMetaObject: {
       Hints const& context_hints = environment()->current_context_hints();
       for (auto x : context_hints.constants()) {
-        ContextRef(broker(), x)
+        MakeRef(broker(), Handle<Context>::cast(x))
             .GetModule(SerializationPolicy::kSerializeIfNeeded)
             .Serialize();
       }
       for (auto x : context_hints.virtual_contexts()) {
-        ContextRef(broker(), x.context)
+        MakeRef(broker(), Handle<Context>::cast(x.context))
             .GetModule(SerializationPolicy::kSerializeIfNeeded)
             .Serialize();
       }
@@ -1535,7 +1539,7 @@ void SerializerForBackgroundCompilation::VisitLdaConstant(
       iterator->GetConstantForIndexOperand(0, broker()->isolate());
   // TODO(v8:7790): FixedArrays still need to be serialized until they are
   // moved to kNeverSerialized.
-  if (!FLAG_turbo_direct_heap_access || constant->IsFixedArray()) {
+  if (!broker()->is_concurrent_inlining() || constant->IsFixedArray()) {
     ObjectRef(broker(), constant);
   }
   environment()->accumulator_hints() = Hints::SingleConstant(constant, zone());
@@ -1579,7 +1583,7 @@ void SerializerForBackgroundCompilation::ProcessContextAccess(
   for (auto x : context_hints.constants()) {
     if (x->IsContext()) {
       // Walk this context to the given depth and serialize the slot found.
-      ContextRef context_ref(broker(), x);
+      ContextRef context_ref = MakeRef(broker(), Handle<Context>::cast(x));
       size_t remaining_depth = depth;
       context_ref = context_ref.previous(
           &remaining_depth, SerializationPolicy::kSerializeIfNeeded);
@@ -1590,7 +1594,8 @@ void SerializerForBackgroundCompilation::ProcessContextAccess(
   }
   for (auto x : context_hints.virtual_contexts()) {
     if (x.distance <= static_cast<unsigned int>(depth)) {
-      ContextRef context_ref(broker(), x.context);
+      ContextRef context_ref =
+          MakeRef(broker(), Handle<Context>::cast(x.context));
       size_t remaining_depth = depth - x.distance;
       context_ref = context_ref.previous(
           &remaining_depth, SerializationPolicy::kSerializeIfNeeded);
@@ -1722,7 +1727,7 @@ void SerializerForBackgroundCompilation::VisitCreateRegExpLiteral(
     BytecodeArrayIterator* iterator) {
   Handle<String> constant_pattern = Handle<String>::cast(
       iterator->GetConstantForIndexOperand(0, broker()->isolate()));
-  StringRef description(broker(), constant_pattern);
+  MakeRef(broker(), constant_pattern);
   FeedbackSlot slot = iterator->GetSlotOperand(1);
   FeedbackSource source(feedback_vector(), slot);
   broker()->ProcessFeedbackForRegExpLiteral(source);
@@ -1734,8 +1739,7 @@ void SerializerForBackgroundCompilation::VisitCreateArrayLiteral(
   Handle<ArrayBoilerplateDescription> array_boilerplate_description =
       Handle<ArrayBoilerplateDescription>::cast(
           iterator->GetConstantForIndexOperand(0, broker()->isolate()));
-  ArrayBoilerplateDescriptionRef description(broker(),
-                                             array_boilerplate_description);
+  MakeRef(broker(), array_boilerplate_description);
   FeedbackSlot slot = iterator->GetSlotOperand(1);
   FeedbackSource source(feedback_vector(), slot);
   broker()->ProcessFeedbackForArrayOrObjectLiteral(source);
@@ -1755,7 +1759,7 @@ void SerializerForBackgroundCompilation::VisitCreateObjectLiteral(
   Handle<ObjectBoilerplateDescription> constant_properties =
       Handle<ObjectBoilerplateDescription>::cast(
           iterator->GetConstantForIndexOperand(0, broker()->isolate()));
-  ObjectBoilerplateDescriptionRef description(broker(), constant_properties);
+  MakeRef(broker(), constant_properties);
   FeedbackSlot slot = iterator->GetSlotOperand(1);
   FeedbackSource source(feedback_vector(), slot);
   broker()->ProcessFeedbackForArrayOrObjectLiteral(source);
@@ -1804,7 +1808,7 @@ void SerializerForBackgroundCompilation::ProcessCreateContext(
   Handle<ScopeInfo> scope_info =
       Handle<ScopeInfo>::cast(iterator->GetConstantForIndexOperand(
           scopeinfo_operand_index, broker()->isolate()));
-  ScopeInfoRef scope_info_ref(broker(), scope_info);
+  ScopeInfoRef scope_info_ref = MakeRef(broker(), scope_info);
   scope_info_ref.SerializeScopeInfoChain();
 
   Hints const& current_context_hints = environment()->current_context_hints();
@@ -1836,9 +1840,9 @@ void SerializerForBackgroundCompilation::VisitCreateClosure(
       iterator->GetConstantForIndexOperand(0, broker()->isolate()));
   Handle<FeedbackCell> feedback_cell =
       feedback_vector()->GetClosureFeedbackCell(iterator->GetIndexOperand(1));
-  FeedbackCellRef feedback_cell_ref(broker(), feedback_cell);
+  MakeRef(broker(), feedback_cell);
   Handle<Object> cell_value(feedback_cell->value(), broker()->isolate());
-  ObjectRef cell_value_ref(broker(), cell_value);
+  MakeRef(broker(), cell_value);
 
   Hints result_hints;
   if (cell_value->IsFeedbackVector()) {
@@ -2109,8 +2113,8 @@ void SerializerForBackgroundCompilation::ProcessCalleeForCallOrConstruct(
   const HintsVector* actual_arguments = &arguments;
   HintsVector expanded_arguments(zone());
   if (callee->IsJSBoundFunction()) {
-    JSBoundFunctionRef bound_function(broker(),
-                                      Handle<JSBoundFunction>::cast(callee));
+    JSBoundFunctionRef bound_function =
+        MakeRef(broker(), Handle<JSBoundFunction>::cast(callee));
     if (!bound_function.Serialize()) return;
     callee = UnrollBoundFunction(bound_function, broker(), arguments,
                                  &expanded_arguments, zone())
@@ -2119,7 +2123,7 @@ void SerializerForBackgroundCompilation::ProcessCalleeForCallOrConstruct(
   }
   if (!callee->IsJSFunction()) return;
 
-  JSFunctionRef function(broker(), Handle<JSFunction>::cast(callee));
+  JSFunctionRef function = MakeRef(broker(), Handle<JSFunction>::cast(callee));
   function.Serialize();
   Callee new_callee(function.object());
   ProcessCalleeForCallOrConstruct(new_callee, new_target, *actual_arguments,
@@ -2266,13 +2270,13 @@ void SerializerForBackgroundCompilation::ProcessApiCall(
         Builtins::kCallFunctionTemplate_CheckAccessAndCompatibleReceiver}) {
     ObjectRef(broker(), broker()->isolate()->builtins()->builtin_handle(b));
   }
-  FunctionTemplateInfoRef target_template_info(
-      broker(),
-      broker()->CanonicalPersistentHandle(target->function_data(kAcquireLoad)));
+  FunctionTemplateInfoRef target_template_info =
+      MakeRef(broker(),
+              FunctionTemplateInfo::cast(target->function_data(kAcquireLoad)));
   if (!target_template_info.has_call_code()) return;
   target_template_info.SerializeCallCode();
 
-  SharedFunctionInfoRef target_ref(broker(), target);
+  SharedFunctionInfoRef target_ref = MakeRef(broker(), target);
   target_ref.SerializeFunctionTemplateInfo();
 
   if (target_template_info.accept_any_receiver() &&
@@ -2308,7 +2312,7 @@ void SerializerForBackgroundCompilation::ProcessApiCall(
 void SerializerForBackgroundCompilation::ProcessReceiverMapForApiCall(
     FunctionTemplateInfoRef target, Handle<Map> receiver) {
   if (!receiver->is_access_check_needed()) {
-    MapRef receiver_map(broker(), receiver);
+    MapRef receiver_map = MakeRef(broker(), receiver);
     TRACE_BROKER(broker(), "Serializing holder for target: " << target);
     target.LookupHolderOfExpectedType(receiver_map,
                                       SerializationPolicy::kSerializeIfNeeded);
@@ -2356,10 +2360,10 @@ void SerializerForBackgroundCompilation::ProcessBuiltinCall(
         if (arguments.size() >= 1) {
           ProcessMapHintsForPromises(arguments[0]);
         }
-        SharedFunctionInfoRef(
+        MakeRef(
             broker(),
             broker()->isolate()->factory()->promise_catch_finally_shared_fun());
-        SharedFunctionInfoRef(
+        MakeRef(
             broker(),
             broker()->isolate()->factory()->promise_then_finally_shared_fun());
       }
@@ -2496,16 +2500,14 @@ void SerializerForBackgroundCompilation::ProcessBuiltinCall(
               kMissingArgumentsAreUnknown, result_hints);
         }
       }
-      SharedFunctionInfoRef(
-          broker(), broker()
-                        ->isolate()
-                        ->factory()
-                        ->promise_capability_default_reject_shared_fun());
-      SharedFunctionInfoRef(
-          broker(), broker()
-                        ->isolate()
-                        ->factory()
-                        ->promise_capability_default_resolve_shared_fun());
+      MakeRef(broker(), broker()
+                            ->isolate()
+                            ->factory()
+                            ->promise_capability_default_reject_shared_fun());
+      MakeRef(broker(), broker()
+                            ->isolate()
+                            ->factory()
+                            ->promise_capability_default_resolve_shared_fun());
 
       break;
     case Builtins::kFunctionPrototypeCall:
@@ -2529,7 +2531,7 @@ void SerializerForBackgroundCompilation::ProcessBuiltinCall(
       if (arguments.size() >= 2) {
         for (auto constant : arguments[1].constants()) {
           if (constant->IsJSFunction()) {
-            JSFunctionRef(broker(), constant).Serialize();
+            MakeRef(broker(), Handle<JSFunction>::cast(constant)).Serialize();
           }
         }
       }
@@ -2596,7 +2598,8 @@ void SerializerForBackgroundCompilation::ProcessHintsForOrdinaryHasInstance(
     // For JSNativeContextSpecialization::ReduceJSOrdinaryHasInstance.
     if (constructor->IsHeapObject()) {
       ProcessConstantForOrdinaryHasInstance(
-          HeapObjectRef(broker(), constructor), &walk_prototypes);
+          MakeRef(broker(), Handle<HeapObject>::cast(constructor)),
+          &walk_prototypes);
     }
   }
   // For JSNativeContextSpecialization::ReduceJSHasInPrototypeChain.
@@ -2606,10 +2609,10 @@ void SerializerForBackgroundCompilation::ProcessHintsForOrdinaryHasInstance(
 void SerializerForBackgroundCompilation::ProcessHintsForHasInPrototypeChain(
     Hints const& instance_hints) {
   auto processMap = [&](Handle<Map> map_handle) {
-    MapRef map(broker(), map_handle);
+    MapRef map = MakeRef(broker(), map_handle);
     while (map.IsJSObjectMap()) {
       map.SerializePrototype();
-      map = map.prototype().map();
+      map = map.prototype().value().map();
     }
   };
 
@@ -2627,8 +2630,8 @@ void SerializerForBackgroundCompilation::ProcessHintsForPromiseResolve(
     Hints const& resolution_hints) {
   auto processMap = [&](Handle<Map> map) {
     broker()->GetPropertyAccessInfo(
-        MapRef(broker(), map),
-        NameRef(broker(), broker()->isolate()->factory()->then_string()),
+        MakeRef(broker(), map),
+        MakeRef(broker(), broker()->isolate()->factory()->then_string()),
         AccessMode::kLoad, dependencies(),
         SerializationPolicy::kSerializeIfNeeded);
   };
@@ -2650,25 +2653,25 @@ void SerializerForBackgroundCompilation::ProcessMapHintsForPromises(
     if (!constant->IsJSPromise()) continue;
     Handle<Map> map(Handle<HeapObject>::cast(constant)->map(),
                     broker()->isolate());
-    MapRef(broker(), map).SerializePrototype();
+    MakeRef(broker(), map).SerializePrototype();
   }
   for (auto map : receiver_hints.maps()) {
     if (!map->IsJSPromiseMap()) continue;
-    MapRef(broker(), map).SerializePrototype();
+    MakeRef(broker(), map).SerializePrototype();
   }
 }
 
 PropertyAccessInfo SerializerForBackgroundCompilation::ProcessMapForRegExpTest(
     MapRef map) {
   PropertyAccessInfo ai_exec = broker()->GetPropertyAccessInfo(
-      map, NameRef(broker(), broker()->isolate()->factory()->exec_string()),
+      map, MakeRef(broker(), broker()->isolate()->factory()->exec_string()),
       AccessMode::kLoad, dependencies(),
       SerializationPolicy::kSerializeIfNeeded);
 
   Handle<JSObject> holder;
   if (ai_exec.IsFastDataConstant() && ai_exec.holder().ToHandle(&holder)) {
     // The property is on the prototype chain.
-    JSObjectRef holder_ref(broker(), holder);
+    JSObjectRef holder_ref = MakeRef(broker(), holder);
     holder_ref.GetOwnFastDataProperty(ai_exec.field_representation(),
                                       ai_exec.field_index(),
                                       SerializationPolicy::kSerializeIfNeeded);
@@ -2680,14 +2683,14 @@ void SerializerForBackgroundCompilation::ProcessHintsForRegExpTest(
     Hints const& regexp_hints) {
   for (auto hint : regexp_hints.constants()) {
     if (!hint->IsJSRegExp()) continue;
-    Handle<JSRegExp> regexp(Handle<JSRegExp>::cast(hint));
+    Handle<JSObject> regexp(Handle<JSObject>::cast(hint));
     Handle<Map> regexp_map(regexp->map(), broker()->isolate());
     PropertyAccessInfo ai_exec =
-        ProcessMapForRegExpTest(MapRef(broker(), regexp_map));
+        ProcessMapForRegExpTest(MakeRef(broker(), regexp_map));
     Handle<JSObject> holder;
     if (ai_exec.IsFastDataConstant() && !ai_exec.holder().ToHandle(&holder)) {
       // The property is on the object itself.
-      JSObjectRef holder_ref(broker(), regexp);
+      JSObjectRef holder_ref = MakeRef(broker(), regexp);
       holder_ref.GetOwnFastDataProperty(
           ai_exec.field_representation(), ai_exec.field_index(),
           SerializationPolicy::kSerializeIfNeeded);
@@ -2696,7 +2699,7 @@ void SerializerForBackgroundCompilation::ProcessHintsForRegExpTest(
 
   for (auto map : regexp_hints.maps()) {
     if (!map->IsJSRegExpMap()) continue;
-    ProcessMapForRegExpTest(MapRef(broker(), map));
+    ProcessMapForRegExpTest(MakeRef(broker(), map));
   }
 }
 
@@ -2718,14 +2721,15 @@ void SerializerForBackgroundCompilation::ProcessHintsForFunctionBind(
     Hints const& receiver_hints) {
   for (auto constant : receiver_hints.constants()) {
     if (!constant->IsJSFunction()) continue;
-    JSFunctionRef function(broker(), constant);
+    JSFunctionRef function =
+        MakeRef(broker(), Handle<JSFunction>::cast(constant));
     function.Serialize();
     ProcessMapForFunctionBind(function.map());
   }
 
   for (auto map : receiver_hints.maps()) {
     if (!map->IsJSFunctionMap()) continue;
-    MapRef map_ref(broker(), map);
+    MapRef map_ref = MakeRef(broker(), map);
     ProcessMapForFunctionBind(map_ref);
   }
 }
@@ -2734,13 +2738,13 @@ void SerializerForBackgroundCompilation::ProcessHintsForObjectGetPrototype(
     Hints const& object_hints) {
   for (auto constant : object_hints.constants()) {
     if (!constant->IsHeapObject()) continue;
-    HeapObjectRef object(broker(), constant);
+    HeapObjectRef object =
+        MakeRef(broker(), Handle<HeapObject>::cast(constant));
     object.map().SerializePrototype();
   }
 
   for (auto map : object_hints.maps()) {
-    MapRef map_ref(broker(), map);
-    map_ref.SerializePrototype();
+    MakeRef(broker(), map).SerializePrototype();
   }
 }
 
@@ -2850,7 +2854,7 @@ void SerializerForBackgroundCompilation::ProcessGlobalAccess(FeedbackSlot slot,
 
 void SerializerForBackgroundCompilation::VisitLdaGlobal(
     BytecodeArrayIterator* iterator) {
-  NameRef(broker(),
+  MakeRef(broker(),
           iterator->GetConstantForIndexOperand(0, broker()->isolate()));
   FeedbackSlot slot = iterator->GetSlotOperand(1);
   ProcessGlobalAccess(slot, true);
@@ -2863,15 +2867,15 @@ void SerializerForBackgroundCompilation::VisitLdaGlobalInsideTypeof(
 
 void SerializerForBackgroundCompilation::VisitLdaLookupSlot(
     BytecodeArrayIterator* iterator) {
-  ObjectRef(broker(),
-            iterator->GetConstantForIndexOperand(0, broker()->isolate()));
+  MakeRef(broker(),
+          iterator->GetConstantForIndexOperand(0, broker()->isolate()));
   environment()->accumulator_hints() = Hints();
 }
 
 void SerializerForBackgroundCompilation::VisitLdaLookupSlotInsideTypeof(
     BytecodeArrayIterator* iterator) {
-  ObjectRef(broker(),
-            iterator->GetConstantForIndexOperand(0, broker()->isolate()));
+  MakeRef(broker(),
+          iterator->GetConstantForIndexOperand(0, broker()->isolate()));
   environment()->accumulator_hints() = Hints();
 }
 
@@ -2883,7 +2887,7 @@ void SerializerForBackgroundCompilation::ProcessCheckContextExtensions(
     ProcessContextAccess(context_hints, Context::EXTENSION_INDEX, i,
                          kSerializeSlot);
   }
-  SharedFunctionInfoRef shared(broker(), function().shared());
+  SharedFunctionInfoRef shared = MakeRef(broker(), function().shared());
   shared.SerializeScopeInfoChain();
 }
 
@@ -2906,7 +2910,7 @@ void SerializerForBackgroundCompilation::VisitLdaLookupGlobalSlotInsideTypeof(
 
 void SerializerForBackgroundCompilation::VisitStaGlobal(
     BytecodeArrayIterator* iterator) {
-  NameRef(broker(),
+  MakeRef(broker(),
           iterator->GetConstantForIndexOperand(0, broker()->isolate()));
   FeedbackSlot slot = iterator->GetSlotOperand(1);
   ProcessGlobalAccess(slot, false);
@@ -2916,7 +2920,7 @@ void SerializerForBackgroundCompilation::ProcessLdaLookupContextSlot(
     BytecodeArrayIterator* iterator) {
   const int slot_index = iterator->GetIndexOperand(1);
   const int depth = iterator->GetUnsignedImmediateOperand(2);
-  NameRef(broker(),
+  MakeRef(broker(),
           iterator->GetConstantForIndexOperand(0, broker()->isolate()));
   ProcessCheckContextExtensions(depth);
   environment()->accumulator_hints() = Hints();
@@ -3016,7 +3020,8 @@ SerializerForBackgroundCompilation::ProcessMapForNamedPropertyAccess(
        access_info.IsDictionaryProtoAccessorConstant()) &&
       !access_info.constant().is_null()) {
     if (access_info.constant()->IsJSFunction()) {
-      JSFunctionRef function(broker(), access_info.constant());
+      JSFunctionRef function =
+          MakeRef(broker(), Handle<JSFunction>::cast(access_info.constant()));
 
       if (receiver_map.has_value()) {
         // For JSCallReducer and JSInlining(Heuristic).
@@ -3033,9 +3038,8 @@ SerializerForBackgroundCompilation::ProcessMapForNamedPropertyAccess(
         // For JSCallReducer::ReduceCallApiFunction.
         Handle<SharedFunctionInfo> sfi = function.shared().object();
         if (sfi->IsApiFunction()) {
-          FunctionTemplateInfoRef fti_ref(
-              broker(),
-              broker()->CanonicalPersistentHandle(sfi->get_api_func_data()));
+          FunctionTemplateInfoRef fti_ref =
+              MakeRef(broker(), sfi->get_api_func_data());
           if (fti_ref.has_call_code()) {
             fti_ref.SerializeCallCode();
             ProcessReceiverMapForApiCall(fti_ref, receiver_map->object());
@@ -3043,19 +3047,19 @@ SerializerForBackgroundCompilation::ProcessMapForNamedPropertyAccess(
         }
       }
     } else if (access_info.constant()->IsJSBoundFunction()) {
-      JSBoundFunctionRef function(broker(), access_info.constant());
-
       // For JSCallReducer::ReduceJSCall.
+      JSBoundFunctionRef function = MakeRef(
+          broker(), Handle<JSBoundFunction>::cast(access_info.constant()));
       function.Serialize();
     } else {
-      FunctionTemplateInfoRef fti(broker(), broker()->CanonicalPersistentHandle(
-                                                access_info.constant()));
+      FunctionTemplateInfoRef fti = MakeRef(
+          broker(), FunctionTemplateInfo::cast(*access_info.constant()));
       if (fti.has_call_code()) fti.SerializeCallCode();
     }
   } else if (access_info.IsModuleExport()) {
     // For JSNativeContextSpecialization::BuildPropertyLoad
     DCHECK(!access_info.constant().is_null());
-    CellRef(broker(), access_info.constant());
+    MakeRef(broker(), Handle<Cell>::cast(access_info.constant()));
   }
 
   switch (access_mode) {
@@ -3067,7 +3071,7 @@ SerializerForBackgroundCompilation::ProcessMapForNamedPropertyAccess(
         base::Optional<JSObjectRef> holder;
         Handle<JSObject> prototype;
         if (access_info.holder().ToHandle(&prototype)) {
-          holder = JSObjectRef(broker(), prototype);
+          holder = MakeRef(broker(), prototype);
         } else {
           CHECK_IMPLIES(concrete_receiver.has_value(),
                         concrete_receiver->map().equals(*receiver_map));
@@ -3095,7 +3099,7 @@ SerializerForBackgroundCompilation::ProcessMapForNamedPropertyAccess(
       if (access_info.IsDataField() || access_info.IsFastDataConstant()) {
         Handle<Map> transition_map;
         if (access_info.transition_map().ToHandle(&transition_map)) {
-          MapRef map_ref(broker(), transition_map);
+          MapRef map_ref = MakeRef(broker(), transition_map);
           TRACE_BROKER(broker(), "Propagating transition map "
                                      << map_ref << " to receiver hints.");
           receiver->AddMap(transition_map, zone(), broker_, false);
@@ -3225,7 +3229,7 @@ void SerializerForBackgroundCompilation::ProcessNamedAccess(
     Hints* receiver, NamedAccessFeedback const& feedback,
     AccessMode access_mode, Hints* result_hints) {
   for (Handle<Map> map : feedback.maps()) {
-    MapRef map_ref(broker(), map);
+    MapRef map_ref = MakeRef(broker(), map);
     TRACE_BROKER(broker(), "Propagating feedback map "
                                << map_ref << " to receiver hints.");
     receiver->AddMap(map, zone(), broker_, false);
@@ -3233,7 +3237,7 @@ void SerializerForBackgroundCompilation::ProcessNamedAccess(
 
   for (Handle<Map> map :
        GetRelevantReceiverMaps(broker()->isolate(), receiver->maps())) {
-    MapRef map_ref(broker(), map);
+    MapRef map_ref = MakeRef(broker(), map);
     ProcessMapForNamedPropertyAccess(receiver, map_ref, map_ref,
                                      feedback.name(), access_mode,
                                      base::nullopt, result_hints);
@@ -3249,7 +3253,7 @@ void SerializerForBackgroundCompilation::ProcessNamedAccess(
     }
     // For JSNativeContextSpecialization::ReduceJSLoadNamed.
     if (access_mode == AccessMode::kLoad && object.IsJSFunction() &&
-        feedback.name().equals(ObjectRef(
+        feedback.name().equals(MakeRef(
             broker(), broker()->isolate()->factory()->prototype_string()))) {
       JSFunctionRef function = object.AsJSFunction();
       function.Serialize();
@@ -3269,9 +3273,9 @@ void SerializerForBackgroundCompilation::ProcessNamedSuperAccess(
   MapHandles receiver_maps =
       GetRelevantReceiverMaps(broker()->isolate(), receiver->maps());
   for (Handle<Map> receiver_map : receiver_maps) {
-    MapRef receiver_map_ref(broker(), receiver_map);
+    MapRef receiver_map_ref = MakeRef(broker(), receiver_map);
     for (Handle<Map> feedback_map : feedback.maps()) {
-      MapRef feedback_map_ref(broker(), feedback_map);
+      MapRef feedback_map_ref = MakeRef(broker(), feedback_map);
       ProcessMapForNamedPropertyAccess(
           receiver, receiver_map_ref, feedback_map_ref, feedback.name(),
           access_mode, base::nullopt, result_hints);
@@ -3279,7 +3283,7 @@ void SerializerForBackgroundCompilation::ProcessNamedSuperAccess(
   }
   if (receiver_maps.empty()) {
     for (Handle<Map> feedback_map : feedback.maps()) {
-      MapRef feedback_map_ref(broker(), feedback_map);
+      MapRef feedback_map_ref = MakeRef(broker(), feedback_map);
       ProcessMapForNamedPropertyAccess(
           receiver, base::nullopt, feedback_map_ref, feedback.name(),
           access_mode, base::nullopt, result_hints);
@@ -3292,7 +3296,7 @@ void SerializerForBackgroundCompilation::ProcessElementAccess(
     ElementAccessFeedback const& feedback, AccessMode access_mode) {
   for (auto const& group : feedback.transition_groups()) {
     for (Handle<Map> map_handle : group) {
-      MapRef map(broker(), map_handle);
+      MapRef map = MakeRef(broker(), map_handle);
       switch (access_mode) {
         case AccessMode::kHas:
         case AccessMode::kLoad:
@@ -3352,7 +3356,7 @@ void SerializerForBackgroundCompilation::ProcessElementAccess(
 
   // For JSNativeContextSpecialization::InferRootMap
   for (Handle<Map> map : receiver.maps()) {
-    MapRef map_ref(broker(), map);
+    MapRef map_ref = MakeRef(broker(), map);
     map_ref.SerializeRootMap();
   }
 }
@@ -3360,8 +3364,9 @@ void SerializerForBackgroundCompilation::ProcessElementAccess(
 void SerializerForBackgroundCompilation::VisitLdaNamedProperty(
     BytecodeArrayIterator* iterator) {
   Hints* receiver = &register_hints(iterator->GetRegisterOperand(0));
-  NameRef name(broker(),
-               iterator->GetConstantForIndexOperand(1, broker()->isolate()));
+  NameRef name =
+      MakeRef(broker(), Handle<Name>::cast(iterator->GetConstantForIndexOperand(
+                            1, broker()->isolate())));
   FeedbackSlot slot = iterator->GetSlotOperand(2);
   ProcessNamedPropertyAccess(receiver, name, slot, AccessMode::kLoad);
 }
@@ -3369,8 +3374,9 @@ void SerializerForBackgroundCompilation::VisitLdaNamedProperty(
 void SerializerForBackgroundCompilation::VisitLdaNamedPropertyFromSuper(
     BytecodeArrayIterator* iterator) {
   Hints* receiver = &register_hints(iterator->GetRegisterOperand(0));
-  NameRef name(broker(),
-               iterator->GetConstantForIndexOperand(1, broker()->isolate()));
+  NameRef name =
+      MakeRef(broker(), Handle<Name>::cast(iterator->GetConstantForIndexOperand(
+                            1, broker()->isolate())));
   FeedbackSlot slot = iterator->GetSlotOperand(2);
   ProcessNamedSuperPropertyAccess(receiver, name, slot, AccessMode::kLoad);
 }
@@ -3379,30 +3385,32 @@ void SerializerForBackgroundCompilation::VisitLdaNamedPropertyFromSuper(
 // bytecodes.
 void SerializerForBackgroundCompilation::VisitLdaNamedPropertyNoFeedback(
     BytecodeArrayIterator* iterator) {
-  NameRef(broker(),
-          iterator->GetConstantForIndexOperand(1, broker()->isolate()));
+  MakeRef(broker(), Handle<Name>::cast(iterator->GetConstantForIndexOperand(
+                        1, broker()->isolate())));
 }
 
 void SerializerForBackgroundCompilation::VisitStaNamedProperty(
     BytecodeArrayIterator* iterator) {
   Hints* receiver = &register_hints(iterator->GetRegisterOperand(0));
-  NameRef name(broker(),
-               iterator->GetConstantForIndexOperand(1, broker()->isolate()));
+  NameRef name =
+      MakeRef(broker(), Handle<Name>::cast(iterator->GetConstantForIndexOperand(
+                            1, broker()->isolate())));
   FeedbackSlot slot = iterator->GetSlotOperand(2);
   ProcessNamedPropertyAccess(receiver, name, slot, AccessMode::kStore);
 }
 
 void SerializerForBackgroundCompilation::VisitStaNamedPropertyNoFeedback(
     BytecodeArrayIterator* iterator) {
-  NameRef(broker(),
+  MakeRef(broker(),
           iterator->GetConstantForIndexOperand(1, broker()->isolate()));
 }
 
 void SerializerForBackgroundCompilation::VisitStaNamedOwnProperty(
     BytecodeArrayIterator* iterator) {
   Hints* receiver = &register_hints(iterator->GetRegisterOperand(0));
-  NameRef name(broker(),
-               iterator->GetConstantForIndexOperand(1, broker()->isolate()));
+  NameRef name =
+      MakeRef(broker(), Handle<Name>::cast(iterator->GetConstantForIndexOperand(
+                            1, broker()->isolate())));
   FeedbackSlot slot = iterator->GetSlotOperand(2);
   ProcessNamedPropertyAccess(receiver, name, slot, AccessMode::kStoreInLiteral);
 }
@@ -3440,7 +3448,7 @@ void SerializerForBackgroundCompilation::ProcessConstantForInstanceOf(
 
   PropertyAccessInfo access_info = broker()->GetPropertyAccessInfo(
       constructor_heap_object.map(),
-      NameRef(broker(), broker()->isolate()->factory()->has_instance_symbol()),
+      MakeRef(broker(), broker()->isolate()->factory()->has_instance_symbol()),
       AccessMode::kLoad, dependencies(),
       SerializationPolicy::kSerializeIfNeeded);
 
@@ -3450,8 +3458,8 @@ void SerializerForBackgroundCompilation::ProcessConstantForInstanceOf(
   } else if (access_info.IsFastDataConstant()) {
     Handle<JSObject> holder;
     bool found_on_proto = access_info.holder().ToHandle(&holder);
-    JSObjectRef holder_ref = found_on_proto ? JSObjectRef(broker(), holder)
-                                            : constructor.AsJSObject();
+    JSObjectRef holder_ref =
+        found_on_proto ? MakeRef(broker(), holder) : constructor.AsJSObject();
     base::Optional<ObjectRef> constant = holder_ref.GetOwnFastDataProperty(
         access_info.field_representation(), access_info.field_index(),
         SerializationPolicy::kSerializeIfNeeded);
diff --git a/chromium/v8/src/compiler/simd-scalar-lowering.cc b/chromium/v8/src/compiler/simd-scalar-lowering.cc
deleted file mode 100644
index 7c96393c4ce..00000000000
--- a/chromium/v8/src/compiler/simd-scalar-lowering.cc
+++ /dev/null
@@ -1,2829 +0,0 @@
-// Copyright 2016 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "src/compiler/simd-scalar-lowering.h"
-
-#include "src/base/platform/wrappers.h"
-#include "src/codegen/machine-type.h"
-#include "src/common/globals.h"
-#include "src/compiler/diamond.h"
-#include "src/compiler/linkage.h"
-#include "src/compiler/machine-operator.h"
-#include "src/compiler/node-matchers.h"
-#include "src/compiler/node-properties.h"
-#include "src/compiler/node.h"
-#include "src/compiler/wasm-compiler.h"
-
-namespace v8 {
-namespace internal {
-namespace compiler {
-
-namespace {
-static const int kNumLanes64 = 2;
-static const int kNumLanes32 = 4;
-static const int kNumLanes16 = 8;
-static const int kNumLanes8 = 16;
-static const int32_t kMask16 = 0xFFFF;
-static const int32_t kMask8 = 0xFF;
-static const int32_t kShift16 = 16;
-static const int32_t kShift8 = 24;
-static const int32_t kShiftMask8 = 0x7;
-static const int32_t kShiftMask16 = 0xF;
-static const int32_t kShiftMask32 = 0x1F;
-static const int32_t kShiftMask64 = 0x3F;
-
-// Shift values are taken modulo lane size. This helper calculates the mask
-// required for different shift opcodes.
-int GetMaskForShift(Node* node) {
-  switch (node->opcode()) {
-    case IrOpcode::kI8x16Shl:
-    case IrOpcode::kI8x16ShrS:
-    case IrOpcode::kI8x16ShrU:
-      return kShiftMask8;
-    case IrOpcode::kI16x8Shl:
-    case IrOpcode::kI16x8ShrS:
-    case IrOpcode::kI16x8ShrU:
-      return kShiftMask16;
-    case IrOpcode::kI32x4Shl:
-    case IrOpcode::kI32x4ShrS:
-    case IrOpcode::kI32x4ShrU:
-      return kShiftMask32;
-    case IrOpcode::kI64x2Shl:
-    case IrOpcode::kI64x2ShrS:
-    case IrOpcode::kI64x2ShrU:
-      return kShiftMask64;
-    default:
-      UNIMPLEMENTED();
-  }
-}
-}  // anonymous namespace
-
-SimdScalarLowering::SimdScalarLowering(
-    MachineGraph* mcgraph, SimplifiedOperatorBuilder* simplified,
-    Signature<MachineRepresentation>* signature)
-    : mcgraph_(mcgraph),
-      simplified_(simplified),
-      state_(mcgraph->graph(), 3),
-      stack_(mcgraph_->zone()),
-      replacements_(nullptr),
-      signature_(signature),
-      placeholder_(graph()->NewNode(common()->Dead())),
-      parameter_count_after_lowering_(-1) {
-  DCHECK_NOT_NULL(graph());
-  DCHECK_NOT_NULL(graph()->end());
-  replacements_ = zone()->NewArray<Replacement>(graph()->NodeCount());
-  memset(static_cast<void*>(replacements_), 0,
-         sizeof(Replacement) * graph()->NodeCount());
-}
-
-void SimdScalarLowering::LowerGraph() {
-  stack_.push_back({graph()->end(), 0});
-  state_.Set(graph()->end(), State::kOnStack);
-  replacements_[graph()->end()->id()].type = SimdType::kInt32x4;
-
-  while (!stack_.empty()) {
-    NodeState& top = stack_.back();
-    if (top.input_index == top.node->InputCount()) {
-      // All inputs of top have already been lowered, now lower top.
-      stack_.pop_back();
-      state_.Set(top.node, State::kVisited);
-      LowerNode(top.node);
-    } else {
-      // Push the next input onto the stack.
-      Node* input = top.node->InputAt(top.input_index++);
-      if (state_.Get(input) == State::kUnvisited) {
-        SetLoweredType(input, top.node);
-        if (input->opcode() == IrOpcode::kPhi) {
-          // To break cycles with phi nodes we push phis on a separate stack so
-          // that they are processed after all other nodes.
-          PreparePhiReplacement(input);
-          stack_.push_front({input, 0});
-        } else if (input->opcode() == IrOpcode::kEffectPhi ||
-                   input->opcode() == IrOpcode::kLoop) {
-          stack_.push_front({input, 0});
-        } else {
-          stack_.push_back({input, 0});
-        }
-        state_.Set(input, State::kOnStack);
-      }
-    }
-  }
-}
-
-#define FOREACH_INT64X2_OPCODE(V) \
-  V(I64x2Splat)                   \
-  V(I64x2ExtractLane)             \
-  V(I64x2ReplaceLane)             \
-  V(I64x2Eq)                      \
-  V(I64x2Ne)                      \
-  V(I64x2Neg)                     \
-  V(I64x2Shl)                     \
-  V(I64x2ShrS)                    \
-  V(I64x2ShrU)                    \
-  V(I64x2Add)                     \
-  V(I64x2Sub)                     \
-  V(I64x2Mul)                     \
-  V(I64x2ExtMulLowI32x4S)         \
-  V(I64x2ExtMulLowI32x4U)         \
-  V(I64x2ExtMulHighI32x4S)        \
-  V(I64x2ExtMulHighI32x4U)
-
-#define FOREACH_INT32X4_OPCODE(V) \
-  V(I32x4Splat)                   \
-  V(I32x4ExtractLane)             \
-  V(I32x4ReplaceLane)             \
-  V(I32x4SConvertF32x4)           \
-  V(I32x4UConvertF32x4)           \
-  V(I32x4SConvertI16x8Low)        \
-  V(I32x4SConvertI16x8High)       \
-  V(I32x4Neg)                     \
-  V(I32x4Shl)                     \
-  V(I32x4ShrS)                    \
-  V(I32x4Add)                     \
-  V(I32x4Sub)                     \
-  V(I32x4Mul)                     \
-  V(I32x4MinS)                    \
-  V(I32x4MaxS)                    \
-  V(I32x4ShrU)                    \
-  V(I32x4MinU)                    \
-  V(I32x4MaxU)                    \
-  V(I32x4DotI16x8S)               \
-  V(I32x4Eq)                      \
-  V(I32x4Ne)                      \
-  V(I32x4LtS)                     \
-  V(I32x4LtU)                     \
-  V(I32x4GtS)                     \
-  V(I32x4GtU)                     \
-  V(I32x4LeS)                     \
-  V(I32x4LeU)                     \
-  V(I32x4GeS)                     \
-  V(I32x4GeU)                     \
-  V(I32x4UConvertI16x8Low)        \
-  V(I32x4UConvertI16x8High)       \
-  V(I32x4Abs)                     \
-  V(S128And)                      \
-  V(S128Or)                       \
-  V(S128Xor)                      \
-  V(S128Not)                      \
-  V(S128AndNot)                   \
-  V(S128Select)                   \
-  V(I64x2AllTrue)                 \
-  V(I32x4AllTrue)                 \
-  V(I16x8AllTrue)                 \
-  V(V128AnyTrue)                  \
-  V(I8x16AllTrue)                 \
-  V(I32x4BitMask)                 \
-  V(I32x4ExtMulLowI16x8S)         \
-  V(I32x4ExtMulLowI16x8U)         \
-  V(I32x4ExtMulHighI16x8S)        \
-  V(I32x4ExtMulHighI16x8U)
-
-#define FOREACH_FLOAT64X2_OPCODE(V) \
-  V(F64x2Splat)                     \
-  V(F64x2ExtractLane)               \
-  V(F64x2ReplaceLane)               \
-  V(F64x2Abs)                       \
-  V(F64x2Neg)                       \
-  V(F64x2Sqrt)                      \
-  V(F64x2Add)                       \
-  V(F64x2Sub)                       \
-  V(F64x2Mul)                       \
-  V(F64x2Div)                       \
-  V(F64x2Min)                       \
-  V(F64x2Max)                       \
-  V(F64x2Pmin)                      \
-  V(F64x2Pmax)                      \
-  V(F64x2Ceil)                      \
-  V(F64x2Floor)                     \
-  V(F64x2Trunc)                     \
-  V(F64x2NearestInt)
-
-#define FOREACH_FLOAT32X4_OPCODE(V) \
-  V(F32x4Splat)                     \
-  V(F32x4ExtractLane)               \
-  V(F32x4ReplaceLane)               \
-  V(F32x4SConvertI32x4)             \
-  V(F32x4UConvertI32x4)             \
-  V(F32x4Abs)                       \
-  V(F32x4Neg)                       \
-  V(F32x4Sqrt)                      \
-  V(F32x4RecipApprox)               \
-  V(F32x4RecipSqrtApprox)           \
-  V(F32x4Add)                       \
-  V(F32x4Sub)                       \
-  V(F32x4Mul)                       \
-  V(F32x4Div)                       \
-  V(F32x4Min)                       \
-  V(F32x4Max)                       \
-  V(F32x4Pmin)                      \
-  V(F32x4Pmax)                      \
-  V(F32x4Ceil)                      \
-  V(F32x4Floor)                     \
-  V(F32x4Trunc)                     \
-  V(F32x4NearestInt)
-
-#define FOREACH_FLOAT64x2_TO_INT64x2OPCODE(V) \
-  V(F64x2Eq)                                  \
-  V(F64x2Ne)                                  \
-  V(F64x2Lt)                                  \
-  V(F64x2Le)
-
-#define FOREACH_FLOAT32X4_TO_INT32X4OPCODE(V) \
-  V(F32x4Eq)                                  \
-  V(F32x4Ne)                                  \
-  V(F32x4Lt)                                  \
-  V(F32x4Le)                                  \
-  V(F32x4Gt)                                  \
-  V(F32x4Ge)
-
-#define FOREACH_INT16X8_OPCODE(V) \
-  V(I16x8Splat)                   \
-  V(I16x8ExtractLaneU)            \
-  V(I16x8ExtractLaneS)            \
-  V(I16x8ReplaceLane)             \
-  V(I16x8SConvertI8x16Low)        \
-  V(I16x8SConvertI8x16High)       \
-  V(I16x8Neg)                     \
-  V(I16x8Shl)                     \
-  V(I16x8ShrS)                    \
-  V(I16x8SConvertI32x4)           \
-  V(I16x8Add)                     \
-  V(I16x8AddSatS)                 \
-  V(I16x8Sub)                     \
-  V(I16x8SubSatS)                 \
-  V(I16x8Mul)                     \
-  V(I16x8MinS)                    \
-  V(I16x8MaxS)                    \
-  V(I16x8UConvertI8x16Low)        \
-  V(I16x8UConvertI8x16High)       \
-  V(I16x8ShrU)                    \
-  V(I16x8UConvertI32x4)           \
-  V(I16x8AddSatU)                 \
-  V(I16x8SubSatU)                 \
-  V(I16x8MinU)                    \
-  V(I16x8MaxU)                    \
-  V(I16x8Eq)                      \
-  V(I16x8Ne)                      \
-  V(I16x8LtS)                     \
-  V(I16x8LtU)                     \
-  V(I16x8GtS)                     \
-  V(I16x8GtU)                     \
-  V(I16x8LeS)                     \
-  V(I16x8LeU)                     \
-  V(I16x8GeS)                     \
-  V(I16x8GeU)                     \
-  V(I16x8RoundingAverageU)        \
-  V(I16x8Abs)                     \
-  V(I16x8BitMask)                 \
-  V(I16x8ExtMulLowI8x16S)         \
-  V(I16x8ExtMulLowI8x16U)         \
-  V(I16x8ExtMulHighI8x16S)        \
-  V(I16x8ExtMulHighI8x16U)
-
-#define FOREACH_INT8X16_OPCODE(V) \
-  V(I8x16Splat)                   \
-  V(I8x16ExtractLaneU)            \
-  V(I8x16ExtractLaneS)            \
-  V(I8x16ReplaceLane)             \
-  V(I8x16SConvertI16x8)           \
-  V(I8x16Neg)                     \
-  V(I8x16Shl)                     \
-  V(I8x16ShrS)                    \
-  V(I8x16Add)                     \
-  V(I8x16AddSatS)                 \
-  V(I8x16Sub)                     \
-  V(I8x16SubSatS)                 \
-  V(I8x16MinS)                    \
-  V(I8x16MaxS)                    \
-  V(I8x16ShrU)                    \
-  V(I8x16UConvertI16x8)           \
-  V(I8x16AddSatU)                 \
-  V(I8x16SubSatU)                 \
-  V(I8x16MinU)                    \
-  V(I8x16MaxU)                    \
-  V(I8x16Eq)                      \
-  V(I8x16Ne)                      \
-  V(I8x16LtS)                     \
-  V(I8x16LtU)                     \
-  V(I8x16GtS)                     \
-  V(I8x16GtU)                     \
-  V(I8x16LeS)                     \
-  V(I8x16LeU)                     \
-  V(I8x16GeS)                     \
-  V(I8x16GeU)                     \
-  V(I8x16Swizzle)                 \
-  V(I8x16Shuffle)                 \
-  V(I8x16RoundingAverageU)        \
-  V(I8x16Abs)                     \
-  V(I8x16BitMask)
-
-MachineType SimdScalarLowering::MachineTypeFrom(SimdType simdType) {
-  switch (simdType) {
-    case SimdType::kFloat64x2:
-      return MachineType::Float64();
-    case SimdType::kFloat32x4:
-      return MachineType::Float32();
-    case SimdType::kInt64x2:
-      return MachineType::Int64();
-    case SimdType::kInt32x4:
-      return MachineType::Int32();
-    case SimdType::kInt16x8:
-      return MachineType::Int16();
-    case SimdType::kInt8x16:
-      return MachineType::Int8();
-  }
-  return MachineType::None();
-}
-
-void SimdScalarLowering::SetLoweredType(Node* node, Node* output) {
-  switch (node->opcode()) {
-#define CASE_STMT(name) case IrOpcode::k##name:
-    FOREACH_FLOAT64X2_OPCODE(CASE_STMT) {
-      replacements_[node->id()].type = SimdType::kFloat64x2;
-      break;
-    }
-    FOREACH_INT64X2_OPCODE(CASE_STMT) {
-      replacements_[node->id()].type = SimdType::kInt64x2;
-      break;
-    }
-    FOREACH_INT32X4_OPCODE(CASE_STMT)
-    case IrOpcode::kReturn:
-    case IrOpcode::kParameter:
-    case IrOpcode::kPhi:
-    case IrOpcode::kCall: {
-      replacements_[node->id()].type = SimdType::kInt32x4;
-      break;
-    }
-      FOREACH_FLOAT32X4_OPCODE(CASE_STMT) {
-        replacements_[node->id()].type = SimdType::kFloat32x4;
-        break;
-      }
-      FOREACH_FLOAT32X4_TO_INT32X4OPCODE(CASE_STMT) {
-        replacements_[node->id()].type = SimdType::kInt32x4;
-        break;
-      }
-      FOREACH_FLOAT64x2_TO_INT64x2OPCODE(CASE_STMT) {
-        replacements_[node->id()].type = SimdType::kInt64x2;
-        break;
-      }
-      FOREACH_INT16X8_OPCODE(CASE_STMT) {
-        replacements_[node->id()].type = SimdType::kInt16x8;
-        break;
-      }
-      FOREACH_INT8X16_OPCODE(CASE_STMT) {
-        replacements_[node->id()].type = SimdType::kInt8x16;
-        break;
-      }
-    case IrOpcode::kLoadTransform: {
-      LoadTransformParameters params = LoadTransformParametersOf(node->op());
-      switch (params.transformation) {
-        case LoadTransformation::kS128Load8Splat:
-          replacements_[node->id()].type = SimdType::kInt8x16;
-          break;
-        case LoadTransformation::kS128Load16Splat:
-        case LoadTransformation::kS128Load8x8S:
-        case LoadTransformation::kS128Load8x8U:
-          replacements_[node->id()].type = SimdType::kInt16x8;
-          break;
-        case LoadTransformation::kS128Load32Splat:
-        case LoadTransformation::kS128Load16x4S:
-        case LoadTransformation::kS128Load16x4U:
-        case LoadTransformation::kS128Load32Zero:
-          replacements_[node->id()].type = SimdType::kInt32x4;
-          break;
-        case LoadTransformation::kS128Load64Splat:
-        case LoadTransformation::kS128Load32x2S:
-        case LoadTransformation::kS128Load32x2U:
-        case LoadTransformation::kS128Load64Zero:
-          replacements_[node->id()].type = SimdType::kInt64x2;
-          break;
-        default:
-          UNIMPLEMENTED();
-      }
-      break;
-    }
-    default: {
-      switch (output->opcode()) {
-        case IrOpcode::kF32x4SConvertI32x4:
-        case IrOpcode::kF32x4UConvertI32x4:
-        case IrOpcode::kI16x8SConvertI32x4:
-        case IrOpcode::kI16x8UConvertI32x4: {
-          replacements_[node->id()].type = SimdType::kInt32x4;
-          break;
-        }
-        case IrOpcode::kI8x16SConvertI16x8:
-        case IrOpcode::kI8x16UConvertI16x8:
-        case IrOpcode::kI32x4SConvertI16x8Low:
-        case IrOpcode::kI32x4SConvertI16x8High:
-        case IrOpcode::kI32x4UConvertI16x8Low:
-        case IrOpcode::kI32x4UConvertI16x8High: {
-          replacements_[node->id()].type = SimdType::kInt16x8;
-          break;
-        }
-        case IrOpcode::kI16x8SConvertI8x16Low:
-        case IrOpcode::kI16x8SConvertI8x16High:
-        case IrOpcode::kI16x8UConvertI8x16Low:
-        case IrOpcode::kI16x8UConvertI8x16High: {
-          replacements_[node->id()].type = SimdType::kInt8x16;
-          break;
-        }
-          FOREACH_FLOAT32X4_TO_INT32X4OPCODE(CASE_STMT)
-        case IrOpcode::kI32x4SConvertF32x4:
-        case IrOpcode::kI32x4UConvertF32x4: {
-          replacements_[node->id()].type = SimdType::kFloat32x4;
-          break;
-        }
-        case IrOpcode::kS128Select: {
-          replacements_[node->id()].type = SimdType::kInt32x4;
-          break;
-        }
-        default: {
-          replacements_[node->id()].type = replacements_[output->id()].type;
-        }
-      }
-    }
-#undef CASE_STMT
-  }
-}
-
-static int GetParameterIndexAfterLoweringSimd128(
-    Signature<MachineRepresentation>* signature, int old_index) {
-  // In function calls, the simd128 types are passed as 4 Int32 types. The
-  // parameters are typecast to the types as needed for various operations.
-  int result = old_index;
-  for (int i = 0; i < old_index; ++i) {
-    if (signature->GetParam(i) == MachineRepresentation::kSimd128) {
-      result += 3;
-    }
-  }
-  return result;
-}
-
-int SimdScalarLowering::GetParameterCountAfterLowering() {
-  if (parameter_count_after_lowering_ == -1) {
-    // GetParameterIndexAfterLoweringSimd128(parameter_count) returns the
-    // parameter count after lowering.
-    parameter_count_after_lowering_ = GetParameterIndexAfterLoweringSimd128(
-        signature(), static_cast<int>(signature()->parameter_count()));
-  }
-  return parameter_count_after_lowering_;
-}
-
-static int GetReturnCountAfterLoweringSimd128(
-    Signature<MachineRepresentation>* signature) {
-  int result = static_cast<int>(signature->return_count());
-  for (int i = 0; i < static_cast<int>(signature->return_count()); ++i) {
-    if (signature->GetReturn(i) == MachineRepresentation::kSimd128) {
-      result += 3;
-    }
-  }
-  return result;
-}
-
-int GetReturnIndexAfterLowering(const CallDescriptor* call_descriptor,
-                                int old_index) {
-  int result = old_index;
-  for (int i = 0; i < old_index; ++i) {
-    if (call_descriptor->GetReturnType(i).representation() ==
-        MachineRepresentation::kSimd128) {
-      result += kNumLanes32 - 1;
-    }
-  }
-  return result;
-}
-
-static int GetReturnCountAfterLoweringSimd128(
-    const CallDescriptor* call_descriptor) {
-  return GetReturnIndexAfterLowering(
-      call_descriptor, static_cast<int>(call_descriptor->ReturnCount()));
-}
-
-int SimdScalarLowering::NumLanes(SimdType type) {
-  int num_lanes = 0;
-  if (type == SimdType::kFloat64x2 || type == SimdType::kInt64x2) {
-    num_lanes = kNumLanes64;
-  } else if (type == SimdType::kFloat32x4 || type == SimdType::kInt32x4) {
-    num_lanes = kNumLanes32;
-  } else if (type == SimdType::kInt16x8) {
-    num_lanes = kNumLanes16;
-  } else if (type == SimdType::kInt8x16) {
-    num_lanes = kNumLanes8;
-  } else {
-    UNREACHABLE();
-  }
-  return num_lanes;
-}
-
-constexpr int SimdScalarLowering::kLaneOffsets[];
-
-void SimdScalarLowering::GetIndexNodes(Node* index, Node** new_indices,
-                                       SimdType type) {
-  int num_lanes = NumLanes(type);
-  int lane_width = kSimd128Size / num_lanes;
-  int laneIndex = kLaneOffsets[0] / lane_width;
-
-  Node* rep = index;
-
-  if (HasReplacement(0, index)) {
-    // Index nodes are lowered to scalar nodes.
-    DCHECK_EQ(1, ReplacementCount(index));
-    rep = GetReplacements(index)[0];
-  }
-
-  new_indices[laneIndex] = rep;
-  for (int i = 1; i < num_lanes; ++i) {
-    laneIndex = kLaneOffsets[i * lane_width] / lane_width;
-    new_indices[laneIndex] = graph()->NewNode(
-        machine()->Int32Add(), rep,
-        graph()->NewNode(
-            common()->Int32Constant(static_cast<int>(i) * lane_width)));
-  }
-}
-
-void SimdScalarLowering::LowerLoadOp(Node* node, SimdType type) {
-  MachineRepresentation rep =
-      node->opcode() == IrOpcode::kLoadFromObject
-          ? ObjectAccessOf(node->op()).machine_type.representation()
-          : LoadRepresentationOf(node->op()).representation();
-  const Operator* load_op;
-  switch (node->opcode()) {
-    case IrOpcode::kLoad:
-      load_op = machine()->Load(MachineTypeFrom(type));
-      break;
-    case IrOpcode::kLoadImmutable:
-      load_op = machine()->LoadImmutable(MachineTypeFrom(type));
-      break;
-    case IrOpcode::kLoadFromObject:
-      load_op = simplified()->LoadFromObject(
-          ObjectAccess(MachineTypeFrom(type), kNoWriteBarrier));
-      break;
-    case IrOpcode::kUnalignedLoad:
-      load_op = machine()->UnalignedLoad(MachineTypeFrom(type));
-      break;
-    case IrOpcode::kProtectedLoad:
-      load_op = machine()->ProtectedLoad(MachineTypeFrom(type));
-      break;
-    default:
-      UNREACHABLE();
-  }
-  if (rep == MachineRepresentation::kSimd128) {
-    Node* base = node->InputAt(0);
-    Node* index = node->InputAt(1);
-    int num_lanes = NumLanes(type);
-    Node** indices = zone()->NewArray<Node*>(num_lanes);
-    GetIndexNodes(index, indices, type);
-    Node** rep_nodes = zone()->NewArray<Node*>(num_lanes);
-    rep_nodes[0] = node;
-    rep_nodes[0]->ReplaceInput(1, indices[0]);
-    NodeProperties::ChangeOp(rep_nodes[0], load_op);
-    if (node->InputCount() > 2) {
-      DCHECK_LT(3, node->InputCount());
-      Node* effect_input = node->InputAt(2);
-      Node* control_input = node->InputAt(3);
-      for (int i = num_lanes - 1; i > 0; --i) {
-        rep_nodes[i] = graph()->NewNode(load_op, base, indices[i], effect_input,
-                                        control_input);
-        effect_input = rep_nodes[i];
-      }
-      rep_nodes[0]->ReplaceInput(2, rep_nodes[1]);
-    } else {
-      for (int i = 1; i < num_lanes; ++i) {
-        rep_nodes[i] = graph()->NewNode(load_op, base, indices[i]);
-      }
-    }
-    ReplaceNode(node, rep_nodes, num_lanes);
-  } else {
-    DefaultLowering(node);
-  }
-}
-
-void SimdScalarLowering::LowerLoadTransformOp(Node* node, SimdType type) {
-  LoadTransformParameters params = LoadTransformParametersOf(node->op());
-  MachineType load_rep = MachineType::None();
-  SimdType load_type = type;
-
-  // Load extends have a different machine type for loading.
-  switch (params.transformation) {
-    case LoadTransformation::kS128Load8x8S:
-      load_rep = MachineType::Int8();
-      load_type = SimdType::kInt8x16;
-      break;
-    case LoadTransformation::kS128Load8x8U:
-      load_rep = MachineType::Uint8();
-      load_type = SimdType::kInt8x16;
-      break;
-    case LoadTransformation::kS128Load16x4S:
-      load_rep = MachineType::Int16();
-      load_type = SimdType::kInt16x8;
-      break;
-    case LoadTransformation::kS128Load16x4U:
-      load_rep = MachineType::Uint16();
-      load_type = SimdType::kInt16x8;
-      break;
-    case LoadTransformation::kS128Load32x2S:
-      load_rep = MachineType::Int32();
-      load_type = SimdType::kInt32x4;
-      break;
-    case LoadTransformation::kS128Load32x2U:
-      load_rep = MachineType::Uint32();
-      load_type = SimdType::kInt32x4;
-      break;
-    case LoadTransformation::kS128Load8Splat:
-    case LoadTransformation::kS128Load16Splat:
-    case LoadTransformation::kS128Load32Splat:
-    case LoadTransformation::kS128Load64Splat:
-    case LoadTransformation::kS128Load32Zero:
-    case LoadTransformation::kS128Load64Zero:
-      load_rep = MachineTypeFrom(type);
-      break;
-    default:
-      UNREACHABLE();
-  }
-
-  DCHECK_NE(load_rep, MachineType::None());
-
-  const Operator* load_op;
-  switch (params.kind) {
-    case MemoryAccessKind::kNormal:
-      load_op = machine()->Load(load_rep);
-      break;
-    case MemoryAccessKind::kUnaligned:
-      load_op = machine()->UnalignedLoad(load_rep);
-      break;
-    case MemoryAccessKind::kProtected:
-      load_op = machine()->ProtectedLoad(load_rep);
-      break;
-  }
-
-  Node* base = node->InputAt(0);
-  Node* index = node->InputAt(1);
-  int num_lanes = NumLanes(type);
-  Node** reps = zone()->NewArray<Node*>(num_lanes);
-  Node* effect_input = node->InputAt(2);
-  Node* control_input = node->InputAt(3);
-
-  // This node is also used as effect input into other nodes, so we need to
-  // change this node in place.
-  reps[0] = node;
-  NodeProperties::ChangeOp(reps[0], load_op);
-
-  if (type != load_type) {
-    // We load a smaller lane size, then extend to a larger lane size. So use
-    // the smaller lane size to calculte the index nodes for loads, but only
-    // actually load half of those lanes.
-    Node** indices = zone()->NewArray<Node*>(num_lanes * 2);
-    GetIndexNodes(index, indices, load_type);
-
-    reps[0]->ReplaceInput(1, indices[0]);
-
-    for (int i = num_lanes - 1; i > 0; --i) {
-      reps[i] = graph()->NewNode(load_op, base, indices[i], effect_input,
-                                 control_input);
-      effect_input = reps[i];
-    }
-  } else {
-    if (params.transformation == LoadTransformation::kS128Load32Zero) {
-      for (int i = num_lanes - 1; i > 0; --i) {
-        reps[i] = mcgraph_->Int32Constant(0);
-      }
-    } else if (params.transformation == LoadTransformation::kS128Load64Zero) {
-      for (int i = num_lanes - 1; i > 0; --i) {
-        reps[i] = mcgraph_->Int64Constant(0);
-      }
-    } else {
-      // Load splat, load from the same index for every lane.
-      Node* rep = HasReplacement(0, index) ? GetReplacements(index)[0] : index;
-
-      // Replace first node, we only called ChangeOp above.
-      reps[0]->ReplaceInput(1, rep);
-      for (int i = num_lanes - 1; i > 0; --i) {
-        reps[i] =
-            graph()->NewNode(load_op, base, rep, effect_input, control_input);
-        effect_input = reps[i];
-      }
-    }
-  }
-
-  // Update the effect input, completing the effect chain, but only if there is
-  // an effect output (LoadZero does not have an effect output, it is zero).
-  if (reps[1]->op()->EffectOutputCount() > 0) {
-    reps[0]->ReplaceInput(2, reps[1]);
-  }
-
-  // Special case, the load nodes need to be sign extended, and we do it here so
-  // the loop above can connect all the effect edges correctly.
-  if (params.transformation == LoadTransformation::kS128Load32x2S) {
-    for (int i = 0; i < num_lanes; ++i) {
-      reps[i] = graph()->NewNode(machine()->ChangeInt32ToInt64(), reps[i]);
-    }
-  } else if (params.transformation == LoadTransformation::kS128Load32x2U) {
-    for (int i = 0; i < num_lanes; ++i) {
-      reps[i] = graph()->NewNode(machine()->ChangeUint32ToUint64(), reps[i]);
-    }
-  }
-
-  ReplaceNode(node, reps, num_lanes);
-}
-
-void SimdScalarLowering::LowerStoreOp(Node* node) {
-  // For store operation, use replacement type of its input instead of the
-  // one of its effected node.
-  DCHECK_LT(2, node->InputCount());
-  SimdType rep_type = ReplacementType(node->InputAt(2));
-  replacements_[node->id()].type = rep_type;
-  const Operator* store_op;
-  MachineRepresentation rep;
-  switch (node->opcode()) {
-    case IrOpcode::kStore: {
-      rep = StoreRepresentationOf(node->op()).representation();
-      WriteBarrierKind write_barrier_kind =
-          StoreRepresentationOf(node->op()).write_barrier_kind();
-      store_op = machine()->Store(StoreRepresentation(
-          MachineTypeFrom(rep_type).representation(), write_barrier_kind));
-      break;
-    }
-    case IrOpcode::kStoreToObject: {
-      rep = ObjectAccessOf(node->op()).machine_type.representation();
-      WriteBarrierKind write_barrier_kind =
-          ObjectAccessOf(node->op()).write_barrier_kind;
-      store_op = simplified()->StoreToObject(
-          ObjectAccess(MachineTypeFrom(rep_type), write_barrier_kind));
-      break;
-    }
-    case IrOpcode::kUnalignedStore: {
-      rep = UnalignedStoreRepresentationOf(node->op());
-      store_op =
-          machine()->UnalignedStore(MachineTypeFrom(rep_type).representation());
-      break;
-    }
-    case IrOpcode::kProtectedStore: {
-      rep = StoreRepresentationOf(node->op()).representation();
-      store_op =
-          machine()->ProtectedStore(MachineTypeFrom(rep_type).representation());
-      break;
-    }
-    default:
-      UNREACHABLE();
-  }
-  if (rep == MachineRepresentation::kSimd128) {
-    Node* base = node->InputAt(0);
-    Node* index = node->InputAt(1);
-    int num_lanes = NumLanes(rep_type);
-    Node** indices = zone()->NewArray<Node*>(num_lanes);
-    GetIndexNodes(index, indices, rep_type);
-    Node* value = node->InputAt(2);
-    DCHECK(HasReplacement(1, value));
-    Node** rep_nodes = zone()->NewArray<Node*>(num_lanes);
-    rep_nodes[0] = node;
-    Node** rep_inputs = GetReplacementsWithType(value, rep_type);
-    rep_nodes[0]->ReplaceInput(2, rep_inputs[0]);
-    rep_nodes[0]->ReplaceInput(1, indices[0]);
-    NodeProperties::ChangeOp(node, store_op);
-    if (node->InputCount() > 3) {
-      DCHECK_LT(4, node->InputCount());
-      Node* effect_input = node->InputAt(3);
-      Node* control_input = node->InputAt(4);
-      for (int i = num_lanes - 1; i > 0; --i) {
-        rep_nodes[i] =
-            graph()->NewNode(store_op, base, indices[i], rep_inputs[i],
-                             effect_input, control_input);
-        effect_input = rep_nodes[i];
-      }
-      rep_nodes[0]->ReplaceInput(3, rep_nodes[1]);
-    } else {
-      for (int i = 1; i < num_lanes; ++i) {
-        rep_nodes[i] =
-            graph()->NewNode(store_op, base, indices[i], rep_inputs[i]);
-      }
-    }
-    ReplaceNode(node, rep_nodes, num_lanes);
-  } else {
-    DefaultLowering(node);
-  }
-}
-
-void SimdScalarLowering::LowerBinaryOp(Node* node, SimdType input_rep_type,
-                                       const Operator* op,
-                                       bool not_horizontal) {
-  DCHECK_EQ(2, node->InputCount());
-  Node** rep_left = GetReplacementsWithType(node->InputAt(0), input_rep_type);
-  Node** rep_right = GetReplacementsWithType(node->InputAt(1), input_rep_type);
-  int num_lanes = NumLanes(input_rep_type);
-  Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-  if (not_horizontal) {
-    for (int i = 0; i < num_lanes; ++i) {
-      rep_node[i] = graph()->NewNode(op, rep_left[i], rep_right[i]);
-    }
-  } else {
-    for (int i = 0; i < num_lanes / 2; ++i) {
-      rep_node[i] = graph()->NewNode(op, rep_left[i * 2], rep_left[i * 2 + 1]);
-      rep_node[i + num_lanes / 2] =
-          graph()->NewNode(op, rep_right[i * 2], rep_right[i * 2 + 1]);
-    }
-  }
-  ReplaceNode(node, rep_node, num_lanes);
-}
-
-void SimdScalarLowering::LowerCompareOp(Node* node, SimdType input_rep_type,
-                                        const Operator* op,
-                                        bool invert_inputs) {
-  DCHECK_EQ(2, node->InputCount());
-  Node** rep_left = GetReplacementsWithType(node->InputAt(0), input_rep_type);
-  Node** rep_right = GetReplacementsWithType(node->InputAt(1), input_rep_type);
-  int num_lanes = NumLanes(input_rep_type);
-  Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-  for (int i = 0; i < num_lanes; ++i) {
-    Node* cmp_result = nullptr;
-    if (invert_inputs) {
-      cmp_result = graph()->NewNode(op, rep_right[i], rep_left[i]);
-    } else {
-      cmp_result = graph()->NewNode(op, rep_left[i], rep_right[i]);
-    }
-    Diamond d_cmp(graph(), common(), cmp_result);
-    rep_node[i] = ConstructPhiForComparison(d_cmp, input_rep_type, -1, 0);
-  }
-  ReplaceNode(node, rep_node, num_lanes);
-}
-
-Node* SimdScalarLowering::FixUpperBits(Node* input, int32_t shift) {
-  return graph()->NewNode(machine()->Word32Sar(),
-                          graph()->NewNode(machine()->Word32Shl(), input,
-                                           mcgraph_->Int32Constant(shift)),
-                          mcgraph_->Int32Constant(shift));
-}
-
-void SimdScalarLowering::LowerBinaryOpForSmallInt(Node* node,
-                                                  SimdType input_rep_type,
-                                                  const Operator* op,
-                                                  bool not_horizontal) {
-  DCHECK_EQ(2, node->InputCount());
-  DCHECK(input_rep_type == SimdType::kInt16x8 ||
-         input_rep_type == SimdType::kInt8x16);
-  Node** rep_left = GetReplacementsWithType(node->InputAt(0), input_rep_type);
-  Node** rep_right = GetReplacementsWithType(node->InputAt(1), input_rep_type);
-  int num_lanes = NumLanes(input_rep_type);
-  Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-  int32_t shift_val =
-      (input_rep_type == SimdType::kInt16x8) ? kShift16 : kShift8;
-  if (not_horizontal) {
-    for (int i = 0; i < num_lanes; ++i) {
-      rep_node[i] = FixUpperBits(
-          graph()->NewNode(op, rep_left[i], rep_right[i]), shift_val);
-    }
-  } else {
-    for (int i = 0; i < num_lanes / 2; ++i) {
-      rep_node[i] = FixUpperBits(
-          graph()->NewNode(op, rep_left[i * 2], rep_left[i * 2 + 1]),
-          shift_val);
-      rep_node[i + num_lanes / 2] = FixUpperBits(
-          graph()->NewNode(op, rep_right[i * 2], rep_right[i * 2 + 1]),
-          shift_val);
-    }
-  }
-  ReplaceNode(node, rep_node, num_lanes);
-}
-
-Node* SimdScalarLowering::Mask(Node* input, int32_t mask) {
-  return graph()->NewNode(machine()->Word32And(), input,
-                          mcgraph_->Int32Constant(mask));
-}
-
-void SimdScalarLowering::LowerSaturateBinaryOp(Node* node,
-                                               SimdType input_rep_type,
-                                               const Operator* op,
-                                               bool is_signed) {
-  DCHECK_EQ(2, node->InputCount());
-  DCHECK(input_rep_type == SimdType::kInt16x8 ||
-         input_rep_type == SimdType::kInt8x16);
-  Node** rep_left = GetReplacementsWithType(node->InputAt(0), input_rep_type);
-  Node** rep_right = GetReplacementsWithType(node->InputAt(1), input_rep_type);
-  int32_t min = 0;
-  int32_t max = 0;
-  int32_t mask = 0;
-  int32_t shift_val = 0;
-  MachineRepresentation phi_rep;
-  if (input_rep_type == SimdType::kInt16x8) {
-    if (is_signed) {
-      min = std::numeric_limits<int16_t>::min();
-      max = std::numeric_limits<int16_t>::max();
-    } else {
-      min = std::numeric_limits<uint16_t>::min();
-      max = std::numeric_limits<uint16_t>::max();
-    }
-    mask = kMask16;
-    shift_val = kShift16;
-    phi_rep = MachineRepresentation::kWord16;
-  } else {
-    if (is_signed) {
-      min = std::numeric_limits<int8_t>::min();
-      max = std::numeric_limits<int8_t>::max();
-    } else {
-      min = std::numeric_limits<uint8_t>::min();
-      max = std::numeric_limits<uint8_t>::max();
-    }
-    mask = kMask8;
-    shift_val = kShift8;
-    phi_rep = MachineRepresentation::kWord8;
-  }
-  int num_lanes = NumLanes(input_rep_type);
-  Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-  for (int i = 0; i < num_lanes; ++i) {
-    Node* op_result = nullptr;
-    Node* left = is_signed ? rep_left[i] : Mask(rep_left[i], mask);
-    Node* right = is_signed ? rep_right[i] : Mask(rep_right[i], mask);
-    op_result = graph()->NewNode(op, left, right);
-    Diamond d_min(graph(), common(),
-                  graph()->NewNode(machine()->Int32LessThan(), op_result,
-                                   mcgraph_->Int32Constant(min)));
-    rep_node[i] = d_min.Phi(phi_rep, mcgraph_->Int32Constant(min), op_result);
-    Diamond d_max(graph(), common(),
-                  graph()->NewNode(machine()->Int32LessThan(),
-                                   mcgraph_->Int32Constant(max), rep_node[i]));
-    rep_node[i] = d_max.Phi(phi_rep, mcgraph_->Int32Constant(max), rep_node[i]);
-    rep_node[i] =
-        is_signed ? rep_node[i] : FixUpperBits(rep_node[i], shift_val);
-  }
-  ReplaceNode(node, rep_node, num_lanes);
-}
-
-void SimdScalarLowering::LowerUnaryOp(Node* node, SimdType input_rep_type,
-                                      const Operator* op) {
-  DCHECK_EQ(1, node->InputCount());
-  Node** rep = GetReplacementsWithType(node->InputAt(0), input_rep_type);
-  int num_lanes = NumLanes(input_rep_type);
-  Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-  for (int i = 0; i < num_lanes; ++i) {
-    rep_node[i] = graph()->NewNode(op, rep[i]);
-  }
-  ReplaceNode(node, rep_node, num_lanes);
-}
-
-void SimdScalarLowering::LowerIntMinMax(Node* node, const Operator* op,
-                                        bool is_max, SimdType type) {
-  DCHECK_EQ(2, node->InputCount());
-  Node** rep_left = GetReplacementsWithType(node->InputAt(0), type);
-  Node** rep_right = GetReplacementsWithType(node->InputAt(1), type);
-  int num_lanes = NumLanes(type);
-  Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-  MachineRepresentation rep = MachineRepresentation::kNone;
-  if (type == SimdType::kInt32x4) {
-    rep = MachineRepresentation::kWord32;
-  } else if (type == SimdType::kInt16x8) {
-    rep = MachineRepresentation::kWord16;
-  } else if (type == SimdType::kInt8x16) {
-    rep = MachineRepresentation::kWord8;
-  } else {
-    UNREACHABLE();
-  }
-  for (int i = 0; i < num_lanes; ++i) {
-    Diamond d(graph(), common(),
-              graph()->NewNode(op, rep_left[i], rep_right[i]));
-    if (is_max) {
-      rep_node[i] = d.Phi(rep, rep_right[i], rep_left[i]);
-    } else {
-      rep_node[i] = d.Phi(rep, rep_left[i], rep_right[i]);
-    }
-  }
-  ReplaceNode(node, rep_node, num_lanes);
-}
-
-Node* SimdScalarLowering::BuildF64Trunc(Node* input) {
-  if (machine()->Float64RoundTruncate().IsSupported()) {
-    return graph()->NewNode(machine()->Float64RoundTruncate().op(), input);
-  } else {
-    ExternalReference ref = ExternalReference::wasm_f64_trunc();
-    Node* stack_slot =
-        graph()->NewNode(machine()->StackSlot(MachineRepresentation::kFloat64));
-    const Operator* store_op = machine()->Store(
-        StoreRepresentation(MachineRepresentation::kFloat64, kNoWriteBarrier));
-    Node* effect =
-        graph()->NewNode(store_op, stack_slot, mcgraph_->Int32Constant(0),
-                         input, graph()->start(), graph()->start());
-    Node* function = graph()->NewNode(common()->ExternalConstant(ref));
-    Node** args = zone()->NewArray<Node*>(4);
-    args[0] = function;
-    args[1] = stack_slot;
-    args[2] = effect;
-    args[3] = graph()->start();
-    Signature<MachineType>::Builder sig_builder(zone(), 0, 1);
-    sig_builder.AddParam(MachineType::Pointer());
-    auto call_descriptor =
-        Linkage::GetSimplifiedCDescriptor(zone(), sig_builder.Build());
-    Node* call = graph()->NewNode(common()->Call(call_descriptor), 4, args);
-    return graph()->NewNode(machine()->Load(LoadRepresentation::Float64()),
-                            stack_slot, mcgraph_->Int32Constant(0), call,
-                            graph()->start());
-  }
-}
-
-void SimdScalarLowering::LowerConvertFromFloat(Node* node, bool is_signed) {
-  DCHECK_EQ(1, node->InputCount());
-  Node** rep = GetReplacementsWithType(node->InputAt(0), SimdType::kFloat32x4);
-  Node* rep_node[kNumLanes32];
-  Node* double_zero = graph()->NewNode(common()->Float64Constant(0.0));
-  Node* min = graph()->NewNode(
-      common()->Float64Constant(static_cast<double>(is_signed ? kMinInt : 0)));
-  Node* max = graph()->NewNode(common()->Float64Constant(
-      static_cast<double>(is_signed ? kMaxInt : 0xFFFFFFFFu)));
-  for (int i = 0; i < kNumLanes32; ++i) {
-    Node* double_rep =
-        graph()->NewNode(machine()->ChangeFloat32ToFloat64(), rep[i]);
-    Diamond nan_d(
-        graph(), common(),
-        graph()->NewNode(machine()->Float64Equal(), double_rep, double_rep));
-    Node* temp =
-        nan_d.Phi(MachineRepresentation::kFloat64, double_rep, double_zero);
-    Diamond min_d(graph(), common(),
-                  graph()->NewNode(machine()->Float64LessThan(), temp, min));
-    temp = min_d.Phi(MachineRepresentation::kFloat64, min, temp);
-    Diamond max_d(graph(), common(),
-                  graph()->NewNode(machine()->Float64LessThan(), max, temp));
-    temp = max_d.Phi(MachineRepresentation::kFloat64, max, temp);
-    Node* trunc = BuildF64Trunc(temp);
-    if (is_signed) {
-      rep_node[i] = graph()->NewNode(machine()->ChangeFloat64ToInt32(), trunc);
-    } else {
-      rep_node[i] =
-          graph()->NewNode(machine()->TruncateFloat64ToUint32(), trunc);
-    }
-  }
-  ReplaceNode(node, rep_node, kNumLanes32);
-}
-
-void SimdScalarLowering::LowerConvertFromInt(Node* node,
-                                             SimdType input_rep_type,
-                                             SimdType output_rep_type,
-                                             bool is_signed, int start_index) {
-  DCHECK_EQ(1, node->InputCount());
-  Node** rep = GetReplacementsWithType(node->InputAt(0), input_rep_type);
-
-  int32_t mask = 0;
-  if (input_rep_type == SimdType::kInt16x8) {
-    DCHECK_EQ(output_rep_type, SimdType::kInt32x4);
-    mask = kMask16;
-  } else {
-    DCHECK_EQ(output_rep_type, SimdType::kInt16x8);
-    DCHECK_EQ(input_rep_type, SimdType::kInt8x16);
-    mask = kMask8;
-  }
-
-  int num_lanes = NumLanes(output_rep_type);
-  Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-  for (int i = 0; i < num_lanes; ++i) {
-    rep_node[i] =
-        is_signed ? rep[i + start_index] : Mask(rep[i + start_index], mask);
-  }
-
-  ReplaceNode(node, rep_node, num_lanes);
-}
-
-void SimdScalarLowering::LowerPack(Node* node, SimdType input_rep_type,
-                                   SimdType output_rep_type, bool is_signed) {
-  DCHECK_EQ(2, node->InputCount());
-  Node** rep_left = GetReplacementsWithType(node->InputAt(0), input_rep_type);
-  Node** rep_right = GetReplacementsWithType(node->InputAt(1), input_rep_type);
-  const Operator* less_op = machine()->Int32LessThan();
-  Node* min = nullptr;
-  Node* max = nullptr;
-  const Operator* sign_extend;
-  MachineRepresentation phi_rep;
-  if (output_rep_type == SimdType::kInt16x8) {
-    sign_extend = machine()->SignExtendWord16ToInt32();
-    DCHECK(input_rep_type == SimdType::kInt32x4);
-    if (is_signed) {
-      min = mcgraph_->Int32Constant(std::numeric_limits<int16_t>::min());
-      max = mcgraph_->Int32Constant(std::numeric_limits<int16_t>::max());
-    } else {
-      min = mcgraph_->Uint32Constant(std::numeric_limits<uint16_t>::min());
-      max = mcgraph_->Uint32Constant(std::numeric_limits<uint16_t>::max());
-    }
-    phi_rep = MachineRepresentation::kWord16;
-  } else {
-    sign_extend = machine()->SignExtendWord8ToInt32();
-    DCHECK(output_rep_type == SimdType::kInt8x16 &&
-           input_rep_type == SimdType::kInt16x8);
-    if (is_signed) {
-      min = mcgraph_->Int32Constant(std::numeric_limits<int8_t>::min());
-      max = mcgraph_->Int32Constant(std::numeric_limits<int8_t>::max());
-    } else {
-      min = mcgraph_->Uint32Constant(std::numeric_limits<uint8_t>::min());
-      max = mcgraph_->Uint32Constant(std::numeric_limits<uint8_t>::max());
-    }
-    phi_rep = MachineRepresentation::kWord8;
-  }
-  int num_lanes = NumLanes(output_rep_type);
-  Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-  for (int i = 0; i < num_lanes; ++i) {
-    Node* input = nullptr;
-    if (i < num_lanes / 2)
-      input = rep_left[i];
-    else
-      input = rep_right[i - num_lanes / 2];
-    Diamond d_min(graph(), common(), graph()->NewNode(less_op, input, min));
-    input = d_min.Phi(phi_rep, min, input);
-    Diamond d_max(graph(), common(), graph()->NewNode(less_op, max, input));
-    // We keep nodes in sign-extended form. E.g. for uint8_t, we need to
-    // compare with 0x000000ff (saturated narrowing), but the result of
-    // conversion should be 0xffffffff to work well with the rest of lowering.
-    rep_node[i] = graph()->NewNode(sign_extend, d_max.Phi(phi_rep, max, input));
-  }
-  ReplaceNode(node, rep_node, num_lanes);
-}
-
-void SimdScalarLowering::LowerShiftOp(Node* node, SimdType type) {
-  DCHECK_EQ(2, node->InputCount());
-
-  // The shift node, if it has a replacement, should be a single scalar.
-  DCHECK_GE(1, ReplacementCount(node->InputAt(1)));
-  Node* val = (HasReplacement(0, node->InputAt(1)))
-                  ? GetReplacements(node->InputAt(1))[0]
-                  : node->InputAt(1);
-
-  Node* shift_node = Mask(val, GetMaskForShift(node));
-  Node** rep = GetReplacementsWithType(node->InputAt(0), type);
-  int num_lanes = NumLanes(type);
-  Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-  for (int i = 0; i < num_lanes; ++i) {
-    rep_node[i] = rep[i];
-    switch (node->opcode()) {
-      case IrOpcode::kI8x16ShrU:
-        rep_node[i] = Mask(rep_node[i], kMask8);
-        rep_node[i] =
-            graph()->NewNode(machine()->Word32Shr(), rep_node[i], shift_node);
-        break;
-      case IrOpcode::kI16x8ShrU:
-        rep_node[i] = Mask(rep_node[i], kMask16);
-        V8_FALLTHROUGH;
-      case IrOpcode::kI32x4ShrU:
-        rep_node[i] =
-            graph()->NewNode(machine()->Word32Shr(), rep_node[i], shift_node);
-        break;
-      case IrOpcode::kI64x2ShrU:
-        rep_node[i] =
-            graph()->NewNode(machine()->Word64Shr(), rep_node[i], shift_node);
-        break;
-      case IrOpcode::kI64x2Shl:
-        rep_node[i] =
-            graph()->NewNode(machine()->Word64Shl(), rep_node[i], shift_node);
-        break;
-      case IrOpcode::kI32x4Shl:
-        rep_node[i] =
-            graph()->NewNode(machine()->Word32Shl(), rep_node[i], shift_node);
-        break;
-      case IrOpcode::kI16x8Shl:
-        rep_node[i] =
-            graph()->NewNode(machine()->Word32Shl(), rep_node[i], shift_node);
-        rep_node[i] = FixUpperBits(rep_node[i], kShift16);
-        break;
-      case IrOpcode::kI8x16Shl:
-        rep_node[i] =
-            graph()->NewNode(machine()->Word32Shl(), rep_node[i], shift_node);
-        rep_node[i] = FixUpperBits(rep_node[i], kShift8);
-        break;
-      case IrOpcode::kI64x2ShrS:
-        rep_node[i] =
-            graph()->NewNode(machine()->Word64Sar(), rep_node[i], shift_node);
-        break;
-      case IrOpcode::kI32x4ShrS:
-      case IrOpcode::kI16x8ShrS:
-      case IrOpcode::kI8x16ShrS:
-        rep_node[i] =
-            graph()->NewNode(machine()->Word32Sar(), rep_node[i], shift_node);
-        break;
-      default:
-        UNREACHABLE();
-    }
-  }
-  ReplaceNode(node, rep_node, num_lanes);
-}
-
-Node* SimdScalarLowering::ConstructPhiForComparison(Diamond d,
-                                                    SimdType rep_type,
-                                                    int true_value,
-                                                    int false_value) {
-  // Close the given Diamond d using a Phi node, taking care of constructing the
-  // right kind of constants (Int32 or Int64) based on rep_type.
-  if (rep_type == SimdType::kFloat64x2 || rep_type == SimdType::kInt64x2) {
-    MachineRepresentation rep = MachineRepresentation::kWord64;
-    return d.Phi(rep, mcgraph_->Int64Constant(true_value),
-                 mcgraph_->Int64Constant(false_value));
-  } else {
-    MachineRepresentation rep =
-        (rep_type == SimdType::kFloat32x4)
-            ? MachineRepresentation::kWord32
-            : MachineTypeFrom(rep_type).representation();
-    return d.Phi(rep, mcgraph_->Int32Constant(true_value),
-                 mcgraph_->Int32Constant(false_value));
-  }
-}
-
-void SimdScalarLowering::LowerNotEqual(Node* node, SimdType input_rep_type,
-                                       const Operator* op) {
-  DCHECK_EQ(2, node->InputCount());
-  Node** rep_left = GetReplacementsWithType(node->InputAt(0), input_rep_type);
-  Node** rep_right = GetReplacementsWithType(node->InputAt(1), input_rep_type);
-  int num_lanes = NumLanes(input_rep_type);
-  Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-  for (int i = 0; i < num_lanes; ++i) {
-    Diamond d(graph(), common(),
-              graph()->NewNode(op, rep_left[i], rep_right[i]));
-    rep_node[i] = ConstructPhiForComparison(d, input_rep_type, 0, -1);
-  }
-  ReplaceNode(node, rep_node, num_lanes);
-}
-
-void SimdScalarLowering::LowerBitMaskOp(Node* node, SimdType rep_type,
-                                        int msb_index) {
-  Node** reps = GetReplacementsWithType(node->InputAt(0), rep_type);
-  int num_lanes = NumLanes(rep_type);
-  Node** rep_node = zone()->NewArray<Node*>(1);
-  Node* result = mcgraph_->Int32Constant(0);
-  uint32_t mask = 1 << msb_index;
-
-  for (int i = 0; i < num_lanes; ++i) {
-    // Lane i should end up at bit i in the final result.
-    // +-----------------------------------------------------------------+
-    // |       | msb_index |   (i < msb_index)    |    (i > msb_index)   |
-    // +-------+-----------+----------------------+----------------------+
-    // | i8x16 |     7     | msb >> (msb_index-i) | msb << (i-msb_index) |
-    // | i16x8 |    15     | msb >> (msb_index-i) |         n/a          |
-    // | i32x4 |    31     | msb >> (msb_index-i) |         n/a          |
-    // +-------+-----------+----------------------+----------------------+
-    Node* msb = Mask(reps[i], mask);
-
-    if (i < msb_index) {
-      int shift = msb_index - i;
-      Node* shifted = graph()->NewNode(machine()->Word32Shr(), msb,
-                                       mcgraph_->Int32Constant(shift));
-      result = graph()->NewNode(machine()->Word32Or(), shifted, result);
-    } else if (i > msb_index) {
-      int shift = i - msb_index;
-      Node* shifted = graph()->NewNode(machine()->Word32Shl(), msb,
-                                       mcgraph_->Int32Constant(shift));
-      result = graph()->NewNode(machine()->Word32Or(), shifted, result);
-    } else {
-      result = graph()->NewNode(machine()->Word32Or(), msb, result);
-    }
-  }
-
-  rep_node[0] = result;
-  ReplaceNode(node, rep_node, 1);
-}
-
-void SimdScalarLowering::LowerAllTrueOp(Node* node, SimdType rep_type) {
-  // AllTrue ops require the input to be of a particular SimdType, but the op
-  // itself is always replaced by a Int32x4 with 1 node.
-  int num_lanes = NumLanes(rep_type);
-  DCHECK_EQ(1, node->InputCount());
-  Node** rep = GetReplacementsWithType(node->InputAt(0), rep_type);
-  Node* zero;
-  Node* tmp_result;
-  MachineRepresentation result_rep = MachineRepresentation::kWord32;
-  const Operator* equals;
-
-  if (SimdType::kInt64x2 == rep_type) {
-    zero = mcgraph_->Int64Constant(0);
-    tmp_result = mcgraph_->Int64Constant(1);
-    result_rep = MachineRepresentation::kWord64;
-    equals = machine()->Word64Equal();
-  } else {
-    zero = mcgraph_->Int32Constant(0);
-    tmp_result = mcgraph_->Int32Constant(1);
-    equals = machine()->Word32Equal();
-  }
-
-  Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-  for (int i = 0; i < num_lanes; ++i) {
-    Diamond d(graph(), common(), graph()->NewNode(equals, rep[i], zero));
-    tmp_result = d.Phi(result_rep, zero, tmp_result);
-  }
-
-  if (SimdType::kInt64x2 == rep_type) {
-    tmp_result =
-        graph()->NewNode(machine()->TruncateInt64ToInt32(), tmp_result);
-  }
-
-  rep_node[0] = tmp_result;
-  ReplaceNode(node, rep_node, 1);
-}
-
-void SimdScalarLowering::LowerFloatPseudoMinMax(Node* node, const Operator* op,
-                                                bool is_max, SimdType type) {
-  DCHECK_EQ(2, node->InputCount());
-  Node** rep_left = GetReplacementsWithType(node->InputAt(0), type);
-  Node** rep_right = GetReplacementsWithType(node->InputAt(1), type);
-  int num_lanes = NumLanes(type);
-  Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-  MachineRepresentation rep = MachineTypeFrom(type).representation();
-  for (int i = 0; i < num_lanes; ++i) {
-    Node* cmp = is_max ? graph()->NewNode(op, rep_left[i], rep_right[i])
-                       : graph()->NewNode(op, rep_right[i], rep_left[i]);
-    Diamond d(graph(), common(), cmp);
-    rep_node[i] = d.Phi(rep, rep_right[i], rep_left[i]);
-  }
-  ReplaceNode(node, rep_node, num_lanes);
-}
-
-void SimdScalarLowering::LowerNode(Node* node) {
-  SimdType rep_type = ReplacementType(node);
-  int num_lanes = NumLanes(rep_type);
-  switch (node->opcode()) {
-    case IrOpcode::kS128Const: {
-      // We could use GetReplacementsWithType for all this, but it adds a lot of
-      // nodes, so sign extend the immediates ourselves here.
-      DCHECK_EQ(0, node->InputCount());
-      Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-      S128ImmediateParameter params = S128ImmediateParameterOf(node->op());
-
-      // For all the small ints below, we have a choice of static_cast or bit
-      // twiddling, clang seems to be able to optimize either
-      // (https://godbolt.org/z/9c65o8) so use static_cast for clarity.
-      switch (rep_type) {
-        case SimdType::kInt8x16: {
-          for (int i = 0; i < num_lanes; ++i) {
-            Address data_address = reinterpret_cast<Address>(params.data() + i);
-            rep_node[i] = mcgraph_->Int32Constant(static_cast<int32_t>(
-                base::ReadLittleEndianValue<int8_t>(data_address)));
-          }
-          break;
-        }
-        case SimdType::kInt16x8: {
-          int16_t val[kNumLanes16];
-          base::Memcpy(val, params.data(), kSimd128Size);
-          for (int i = 0; i < num_lanes; ++i) {
-            rep_node[i] = mcgraph_->Int32Constant(static_cast<int32_t>(
-                base::ReadLittleEndianValue<int16_t>(&val[i])));
-          }
-          break;
-        }
-        case SimdType::kInt32x4: {
-          uint32_t val[kNumLanes32];
-          base::Memcpy(val, params.data(), kSimd128Size);
-          for (int i = 0; i < num_lanes; ++i) {
-            rep_node[i] = mcgraph_->Int32Constant(
-                base::ReadLittleEndianValue<uint32_t>(&val[i]));
-          }
-          break;
-        }
-        case SimdType::kInt64x2: {
-          uint64_t val[kNumLanes64];
-          base::Memcpy(val, params.data(), kSimd128Size);
-          for (int i = 0; i < num_lanes; ++i) {
-            rep_node[i] = mcgraph_->Int64Constant(
-                base::ReadLittleEndianValue<uint64_t>(&val[i]));
-          }
-          break;
-        }
-        case SimdType::kFloat32x4: {
-          float val[kNumLanes32];
-          base::Memcpy(val, params.data(), kSimd128Size);
-          for (int i = 0; i < num_lanes; ++i) {
-            rep_node[i] = mcgraph_->Float32Constant(
-                base::ReadLittleEndianValue<float>(&val[i]));
-          }
-          break;
-        }
-        case SimdType::kFloat64x2: {
-          double val[kNumLanes64];
-          base::Memcpy(val, params.data(), kSimd128Size);
-          for (int i = 0; i < num_lanes; ++i) {
-            rep_node[i] = mcgraph_->Float64Constant(
-                base::ReadLittleEndianValue<double>(&val[i]));
-          }
-          break;
-        }
-      }
-      ReplaceNode(node, rep_node, num_lanes);
-      break;
-    }
-    case IrOpcode::kStart: {
-      int parameter_count = GetParameterCountAfterLowering();
-      // Only exchange the node if the parameter count actually changed.
-      if (parameter_count != static_cast<int>(signature()->parameter_count())) {
-        int delta =
-            parameter_count - static_cast<int>(signature()->parameter_count());
-        int new_output_count = node->op()->ValueOutputCount() + delta;
-        NodeProperties::ChangeOp(node, common()->Start(new_output_count));
-      }
-      break;
-    }
-    case IrOpcode::kParameter: {
-      DCHECK_EQ(1, node->InputCount());
-      int param_count = static_cast<int>(signature()->parameter_count());
-      // Only exchange the node if the parameter count actually changed. We do
-      // not even have to do the default lowering because the start node,
-      // the only input of a parameter node, only changes if the parameter count
-      // changes.
-      if (GetParameterCountAfterLowering() != param_count) {
-        int old_index = ParameterIndexOf(node->op());
-        // Parameter index 0 is the instance parameter, we will use old_index to
-        // index into the function signature, so we need to decrease it by 1.
-        --old_index;
-        int new_index =
-            GetParameterIndexAfterLoweringSimd128(signature(), old_index);
-        // Similarly, the index into function signature needs to account for the
-        // instance parameter, so increase it by 1.
-        ++new_index;
-        NodeProperties::ChangeOp(node, common()->Parameter(new_index));
-
-        if (old_index < 0) {
-          break;
-        }
-
-        DCHECK(old_index < param_count);
-
-        if (signature()->GetParam(old_index) ==
-            MachineRepresentation::kSimd128) {
-          Node* new_node[kNumLanes32];
-          new_node[0] = node;
-          for (int i = 1; i < kNumLanes32; ++i) {
-            new_node[i] = graph()->NewNode(common()->Parameter(new_index + i),
-                                           graph()->start());
-          }
-          ReplaceNode(node, new_node, kNumLanes32);
-        }
-      }
-      break;
-    }
-    case IrOpcode::kSimd128ReverseBytes: {
-      DCHECK_EQ(1, node->InputCount());
-      SimdType input_type = ReplacementType(node->InputAt(0));
-      bool is_float = input_type == SimdType::kFloat32x4 ||
-                      input_type == SimdType::kFloat64x2;
-      replacements_[node->id()].type =
-          is_float ? SimdType::kFloat32x4 : SimdType::kInt32x4;
-      Node** rep = GetReplacementsWithType(
-          node->InputAt(0),
-          is_float ? SimdType::kFloat32x4 : SimdType::kInt32x4);
-      Node* rep_node[kNumLanes32];
-      for (int i = 0; i < kNumLanes32; ++i) {
-        Node* temp = is_float ? graph()->NewNode(
-                                    machine()->BitcastFloat32ToInt32(), rep[i])
-                              : rep[i];
-        temp = graph()->NewNode(machine()->Word32ReverseBytes(), temp);
-        rep_node[kNumLanes32 - 1 - i] =
-            is_float
-                ? graph()->NewNode(machine()->BitcastInt32ToFloat32(), temp)
-                : temp;
-      }
-      ReplaceNode(node, rep_node, kNumLanes32);
-      break;
-    }
-    case IrOpcode::kLoad:
-    case IrOpcode::kLoadFromObject:
-    case IrOpcode::kUnalignedLoad:
-    case IrOpcode::kProtectedLoad:
-    case IrOpcode::kLoadImmutable: {
-      LowerLoadOp(node, rep_type);
-      break;
-    }
-    case IrOpcode::kLoadTransform: {
-      LowerLoadTransformOp(node, rep_type);
-      break;
-    }
-    case IrOpcode::kStore:
-    case IrOpcode::kStoreToObject:
-    case IrOpcode::kUnalignedStore:
-    case IrOpcode::kProtectedStore: {
-      LowerStoreOp(node);
-      break;
-    }
-    case IrOpcode::kReturn: {
-      int old_input_count = node->InputCount();
-      int return_arity = static_cast<int>(signature()->return_count());
-      for (int i = 0; i < return_arity; i++) {
-        if (signature()->GetReturn(i) != MachineRepresentation::kSimd128) {
-          continue;
-        }
-
-        // Return nodes have a hidden input at value 0.
-        Node* input = node->InputAt(i + 1);
-        if (!HasReplacement(0, input)) {
-          continue;
-        }
-
-        // V128 return types are lowered to i32x4.
-        Node** reps = GetReplacementsWithType(input, rep_type);
-        ReplaceNode(input, reps, NumLanes(rep_type));
-      }
-
-      DefaultLowering(node);
-      // Nothing needs to be done here since inputs did not change.
-      if (old_input_count == node->InputCount()) {
-        break;
-      }
-
-      int new_return_count = GetReturnCountAfterLoweringSimd128(signature());
-      if (static_cast<int>(signature()->return_count()) != new_return_count) {
-        NodeProperties::ChangeOp(node, common()->Return(new_return_count));
-      }
-      break;
-    }
-    case IrOpcode::kCall: {
-      // TODO(turbofan): Make wasm code const-correct wrt. CallDescriptor.
-      auto call_descriptor =
-          const_cast<CallDescriptor*>(CallDescriptorOf(node->op()));
-      bool returns_require_lowering =
-          GetReturnCountAfterLoweringSimd128(call_descriptor) !=
-          static_cast<int>(call_descriptor->ReturnCount());
-
-      // All call arguments are lowered to i32x4 in the call descriptor, so the
-      // arguments need to be converted to i32x4 as well.
-      for (int i = NodeProperties::PastValueIndex(node) - 1; i >= 0; i--) {
-        Node* input = node->InputAt(i);
-        if (ReplacementCount(input) == 1) {
-          // Special case for extract lanes
-          Node** reps = GetReplacements(input);
-          ReplaceNode(input, reps, 1);
-        } else if (HasReplacement(0, input)) {
-          Node** reps = GetReplacementsWithType(input, SimdType::kInt32x4);
-          ReplaceNode(input, reps, NumLanes(SimdType::kInt32x4));
-        }
-      }
-
-      if (DefaultLowering(node) || returns_require_lowering) {
-        // We have to adjust the call descriptor.
-        const Operator* op = common()->Call(
-            GetI32WasmCallDescriptorForSimd(zone(), call_descriptor));
-        NodeProperties::ChangeOp(node, op);
-      }
-
-      if (!returns_require_lowering) {
-        break;
-      }
-
-      size_t return_arity = call_descriptor->ReturnCount();
-
-      if (return_arity == 1) {
-        // We access the additional return values through projections.
-        // Special case for return_arity 1, with multi-returns, we would have
-        // already built projections for each return value, and will be handled
-        // by the following code.
-        Node* rep_node[kNumLanes32];
-        for (int i = 0; i < kNumLanes32; ++i) {
-          rep_node[i] =
-              graph()->NewNode(common()->Projection(i), node, graph()->start());
-        }
-        ReplaceNode(node, rep_node, kNumLanes32);
-        break;
-      }
-
-      ZoneVector<Node*> projections(return_arity, zone());
-      NodeProperties::CollectValueProjections(node, projections.data(),
-                                              return_arity);
-
-      for (size_t old_index = 0, new_index = 0; old_index < return_arity;
-           ++old_index, ++new_index) {
-        Node* use_node = projections[old_index];
-        DCHECK_EQ(ProjectionIndexOf(use_node->op()), old_index);
-        DCHECK_EQ(GetReturnIndexAfterLowering(call_descriptor,
-                                              static_cast<int>(old_index)),
-                  static_cast<int>(new_index));
-        if (new_index != old_index) {
-          NodeProperties::ChangeOp(use_node, common()->Projection(new_index));
-        }
-        if (call_descriptor->GetReturnType(old_index).representation() ==
-            MachineRepresentation::kSimd128) {
-          Node* rep_node[kNumLanes32];
-          for (int i = 0; i < kNumLanes32; ++i) {
-            rep_node[i] = graph()->NewNode(common()->Projection(new_index + i),
-                                           node, graph()->start());
-          }
-          ReplaceNode(use_node, rep_node, kNumLanes32);
-          new_index += kNumLanes32 - 1;
-        }
-      }
-      break;
-    }
-    case IrOpcode::kPhi: {
-      MachineRepresentation rep = PhiRepresentationOf(node->op());
-      if (rep == MachineRepresentation::kSimd128) {
-        // The replacement nodes have already been created, we only have to
-        // replace placeholder nodes.
-        Node** rep_node = GetReplacements(node);
-        for (int i = 0; i < node->op()->ValueInputCount(); ++i) {
-          Node** rep_input =
-              GetReplacementsWithType(node->InputAt(i), rep_type);
-          for (int j = 0; j < num_lanes; j++) {
-            rep_node[j]->ReplaceInput(i, rep_input[j]);
-          }
-        }
-      } else {
-        DefaultLowering(node);
-      }
-      break;
-    }
-    case IrOpcode::kLoopExitValue: {
-      if (!HasReplacement(0, node->InputAt(0))) break;
-      Node* control = node->InputAt(NodeProperties::FirstControlIndex(node));
-      Node** inputs = GetReplacementsWithType(node->InputAt(0), rep_type);
-      Node** rep_nodes = zone()->NewArray<Node*>(num_lanes);
-      for (int i = 0; i < num_lanes; i++) {
-        auto op =
-            common()->LoopExitValue(MachineTypeFrom(rep_type).representation());
-        rep_nodes[i] = graph()->NewNode(op, inputs[i], control);
-      }
-      ReplaceNode(node, rep_nodes, num_lanes);
-      break;
-    }
-    case IrOpcode::kI64x2Add: {
-      LowerBinaryOp(node, rep_type, machine()->Int64Add());
-      break;
-    }
-    case IrOpcode::kI64x2Sub: {
-      LowerBinaryOp(node, rep_type, machine()->Int64Sub());
-      break;
-    }
-    case IrOpcode::kI64x2Mul: {
-      LowerBinaryOp(node, rep_type, machine()->Int64Mul());
-      break;
-    }
-#define I32X4_BINOP_CASE(opcode, instruction)                \
-  case IrOpcode::opcode: {                                   \
-    LowerBinaryOp(node, rep_type, machine()->instruction()); \
-    break;                                                   \
-  }
-      I32X4_BINOP_CASE(kI32x4Add, Int32Add)
-      I32X4_BINOP_CASE(kI32x4Sub, Int32Sub)
-      I32X4_BINOP_CASE(kI32x4Mul, Int32Mul)
-      I32X4_BINOP_CASE(kS128And, Word32And)
-      I32X4_BINOP_CASE(kS128Or, Word32Or)
-      I32X4_BINOP_CASE(kS128Xor, Word32Xor)
-#undef I32X4_BINOP_CASE
-    case IrOpcode::kI16x8Add:
-    case IrOpcode::kI8x16Add: {
-      LowerBinaryOpForSmallInt(node, rep_type, machine()->Int32Add());
-      break;
-    }
-    case IrOpcode::kI16x8Sub:
-    case IrOpcode::kI8x16Sub: {
-      LowerBinaryOpForSmallInt(node, rep_type, machine()->Int32Sub());
-      break;
-    }
-    case IrOpcode::kI16x8Mul: {
-      LowerBinaryOpForSmallInt(node, rep_type, machine()->Int32Mul());
-      break;
-    }
-    case IrOpcode::kI16x8AddSatS:
-    case IrOpcode::kI8x16AddSatS: {
-      LowerSaturateBinaryOp(node, rep_type, machine()->Int32Add(), true);
-      break;
-    }
-    case IrOpcode::kI16x8SubSatS:
-    case IrOpcode::kI8x16SubSatS: {
-      LowerSaturateBinaryOp(node, rep_type, machine()->Int32Sub(), true);
-      break;
-    }
-    case IrOpcode::kI16x8AddSatU:
-    case IrOpcode::kI8x16AddSatU: {
-      LowerSaturateBinaryOp(node, rep_type, machine()->Int32Add(), false);
-      break;
-    }
-    case IrOpcode::kI16x8SubSatU:
-    case IrOpcode::kI8x16SubSatU: {
-      LowerSaturateBinaryOp(node, rep_type, machine()->Int32Sub(), false);
-      break;
-    }
-    case IrOpcode::kI32x4MaxS:
-    case IrOpcode::kI16x8MaxS:
-    case IrOpcode::kI8x16MaxS: {
-      LowerIntMinMax(node, machine()->Int32LessThan(), true, rep_type);
-      break;
-    }
-    case IrOpcode::kI32x4MinS:
-    case IrOpcode::kI16x8MinS:
-    case IrOpcode::kI8x16MinS: {
-      LowerIntMinMax(node, machine()->Int32LessThan(), false, rep_type);
-      break;
-    }
-    case IrOpcode::kI32x4MaxU:
-    case IrOpcode::kI16x8MaxU:
-    case IrOpcode::kI8x16MaxU: {
-      LowerIntMinMax(node, machine()->Uint32LessThan(), true, rep_type);
-      break;
-    }
-    case IrOpcode::kI32x4MinU:
-    case IrOpcode::kI16x8MinU:
-    case IrOpcode::kI8x16MinU: {
-      LowerIntMinMax(node, machine()->Uint32LessThan(), false, rep_type);
-      break;
-    }
-    case IrOpcode::kI32x4DotI16x8S: {
-      // i32x4.dot_i16x8_s wants the inputs to be i16x8, but outputs to i32x4.
-      DCHECK_EQ(2, node->InputCount());
-      Node** rep_left =
-          GetReplacementsWithType(node->InputAt(0), SimdType::kInt16x8);
-      Node** rep_right =
-          GetReplacementsWithType(node->InputAt(1), SimdType::kInt16x8);
-      int num_lanes = NumLanes(rep_type);
-      Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-      for (int i = 0; i < num_lanes; ++i) {
-        Node* lo = graph()->NewNode(machine()->Int32Mul(), rep_left[i * 2],
-                                    rep_right[i * 2]);
-        Node* hi = graph()->NewNode(machine()->Int32Mul(), rep_left[i * 2 + 1],
-                                    rep_right[i * 2 + 1]);
-        rep_node[i] = graph()->NewNode(machine()->Int32Add(), lo, hi);
-      }
-      ReplaceNode(node, rep_node, num_lanes);
-      break;
-    }
-    case IrOpcode::kI64x2Neg: {
-      DCHECK_EQ(1, node->InputCount());
-      Node** rep = GetReplacementsWithType(node->InputAt(0), rep_type);
-      int num_lanes = NumLanes(rep_type);
-      Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-      Node* zero = graph()->NewNode(common()->Int64Constant(0));
-      for (int i = 0; i < num_lanes; ++i) {
-        rep_node[i] = graph()->NewNode(machine()->Int64Sub(), zero, rep[i]);
-      }
-      ReplaceNode(node, rep_node, num_lanes);
-      break;
-    }
-    case IrOpcode::kI32x4Neg:
-    case IrOpcode::kI16x8Neg:
-    case IrOpcode::kI8x16Neg: {
-      DCHECK_EQ(1, node->InputCount());
-      Node** rep = GetReplacementsWithType(node->InputAt(0), rep_type);
-      int num_lanes = NumLanes(rep_type);
-      Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-      Node* zero = graph()->NewNode(common()->Int32Constant(0));
-      for (int i = 0; i < num_lanes; ++i) {
-        rep_node[i] = graph()->NewNode(machine()->Int32Sub(), zero, rep[i]);
-        if (node->opcode() == IrOpcode::kI16x8Neg) {
-          rep_node[i] = FixUpperBits(rep_node[i], kShift16);
-        } else if (node->opcode() == IrOpcode::kI8x16Neg) {
-          rep_node[i] = FixUpperBits(rep_node[i], kShift8);
-        }
-      }
-      ReplaceNode(node, rep_node, num_lanes);
-      break;
-    }
-    case IrOpcode::kI32x4Abs:
-    case IrOpcode::kI16x8Abs:
-    case IrOpcode::kI8x16Abs: {
-      // From https://stackoverflow.com/a/14194764
-      // abs(x) = (x XOR y) - y
-      Node** rep = GetReplacementsWithType(node->InputAt(0), rep_type);
-      Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-      for (int i = 0; i < num_lanes; ++i) {
-        // It's fine to shift by 31 even for i8x16 since each node is
-        // effectively expanded to 32 bits.
-        Node* y = graph()->NewNode(machine()->Word32Sar(), rep[i],
-                                   mcgraph_->Int32Constant(31));
-        rep_node[i] = graph()->NewNode(
-            machine()->Int32Sub(),
-            graph()->NewNode(machine()->Word32Xor(), rep[i], y), y);
-        if (node->opcode() == IrOpcode::kI16x8Neg) {
-          rep_node[i] = FixUpperBits(rep_node[i], kShift16);
-        } else if (node->opcode() == IrOpcode::kI8x16Neg) {
-          rep_node[i] = FixUpperBits(rep_node[i], kShift8);
-        }
-      }
-      ReplaceNode(node, rep_node, num_lanes);
-      break;
-    }
-    case IrOpcode::kS128Zero: {
-      DCHECK_EQ(0, node->InputCount());
-      Node* rep_node[kNumLanes32];
-      for (int i = 0; i < kNumLanes32; ++i) {
-        rep_node[i] = mcgraph_->Int32Constant(0);
-      }
-      ReplaceNode(node, rep_node, kNumLanes32);
-      break;
-    }
-    case IrOpcode::kS128Not: {
-      DCHECK_EQ(1, node->InputCount());
-      Node** rep = GetReplacementsWithType(node->InputAt(0), rep_type);
-      Node* rep_node[kNumLanes32];
-      Node* mask = graph()->NewNode(common()->Int32Constant(0xFFFFFFFF));
-      for (int i = 0; i < kNumLanes32; ++i) {
-        rep_node[i] = graph()->NewNode(machine()->Word32Xor(), rep[i], mask);
-      }
-      ReplaceNode(node, rep_node, kNumLanes32);
-      break;
-    }
-    case IrOpcode::kS128AndNot: {
-      DCHECK_EQ(2, node->InputCount());
-      Node** rep_left = GetReplacementsWithType(node->InputAt(0), rep_type);
-      Node** rep_right = GetReplacementsWithType(node->InputAt(1), rep_type);
-      int num_lanes = NumLanes(rep_type);
-      Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-      Node* mask = graph()->NewNode(common()->Int32Constant(0xFFFFFFFF));
-      for (int i = 0; i < num_lanes; ++i) {
-        Node* not_rep_right =
-            graph()->NewNode(machine()->Word32Xor(), rep_right[i], mask);
-        rep_node[i] = graph()->NewNode(machine()->Word32And(), rep_left[i],
-                                       not_rep_right);
-      }
-      ReplaceNode(node, rep_node, num_lanes);
-      break;
-    }
-    case IrOpcode::kI32x4SConvertF32x4: {
-      LowerConvertFromFloat(node, true);
-      break;
-    }
-    case IrOpcode::kI32x4UConvertF32x4: {
-      LowerConvertFromFloat(node, false);
-      break;
-    }
-    case IrOpcode::kI32x4SConvertI16x8Low: {
-      LowerConvertFromInt(node, SimdType::kInt16x8, SimdType::kInt32x4, true,
-                          0);
-      break;
-    }
-    case IrOpcode::kI32x4SConvertI16x8High: {
-      LowerConvertFromInt(node, SimdType::kInt16x8, SimdType::kInt32x4, true,
-                          4);
-      break;
-    }
-    case IrOpcode::kI32x4UConvertI16x8Low: {
-      LowerConvertFromInt(node, SimdType::kInt16x8, SimdType::kInt32x4, false,
-                          0);
-      break;
-    }
-    case IrOpcode::kI32x4UConvertI16x8High: {
-      LowerConvertFromInt(node, SimdType::kInt16x8, SimdType::kInt32x4, false,
-                          4);
-      break;
-    }
-    case IrOpcode::kI16x8SConvertI8x16Low: {
-      LowerConvertFromInt(node, SimdType::kInt8x16, SimdType::kInt16x8, true,
-                          0);
-      break;
-    }
-    case IrOpcode::kI16x8SConvertI8x16High: {
-      LowerConvertFromInt(node, SimdType::kInt8x16, SimdType::kInt16x8, true,
-                          8);
-      break;
-    }
-    case IrOpcode::kI16x8UConvertI8x16Low: {
-      LowerConvertFromInt(node, SimdType::kInt8x16, SimdType::kInt16x8, false,
-                          0);
-      break;
-    }
-    case IrOpcode::kI16x8UConvertI8x16High: {
-      LowerConvertFromInt(node, SimdType::kInt8x16, SimdType::kInt16x8, false,
-                          8);
-      break;
-    }
-    case IrOpcode::kI16x8SConvertI32x4: {
-      LowerPack(node, SimdType::kInt32x4, SimdType::kInt16x8, true);
-      break;
-    }
-    case IrOpcode::kI16x8UConvertI32x4: {
-      LowerPack(node, SimdType::kInt32x4, SimdType::kInt16x8, false);
-      break;
-    }
-    case IrOpcode::kI8x16SConvertI16x8: {
-      LowerPack(node, SimdType::kInt16x8, SimdType::kInt8x16, true);
-      break;
-    }
-    case IrOpcode::kI8x16UConvertI16x8: {
-      LowerPack(node, SimdType::kInt16x8, SimdType::kInt8x16, false);
-      break;
-    }
-    case IrOpcode::kI64x2Shl:
-    case IrOpcode::kI32x4Shl:
-    case IrOpcode::kI16x8Shl:
-    case IrOpcode::kI8x16Shl:
-    case IrOpcode::kI64x2ShrS:
-    case IrOpcode::kI32x4ShrS:
-    case IrOpcode::kI16x8ShrS:
-    case IrOpcode::kI8x16ShrS:
-    case IrOpcode::kI64x2ShrU:
-    case IrOpcode::kI32x4ShrU:
-    case IrOpcode::kI16x8ShrU:
-    case IrOpcode::kI8x16ShrU: {
-      LowerShiftOp(node, rep_type);
-      break;
-    }
-#define F32X4_BINOP_CASE(name)                                 \
-  case IrOpcode::kF32x4##name: {                               \
-    LowerBinaryOp(node, rep_type, machine()->Float32##name()); \
-    break;                                                     \
-  }
-      F32X4_BINOP_CASE(Add)
-      F32X4_BINOP_CASE(Sub)
-      F32X4_BINOP_CASE(Mul)
-      F32X4_BINOP_CASE(Div)
-      F32X4_BINOP_CASE(Min)
-      F32X4_BINOP_CASE(Max)
-    case IrOpcode::kF32x4Pmin: {
-      LowerFloatPseudoMinMax(node, machine()->Float32LessThan(), false,
-                             rep_type);
-      break;
-    }
-    case IrOpcode::kF32x4Pmax: {
-      LowerFloatPseudoMinMax(node, machine()->Float32LessThan(), true,
-                             rep_type);
-      break;
-    }
-#undef F32X4_BINOP_CASE
-#define F32X4_UNOP_CASE(name)                                 \
-  case IrOpcode::kF32x4##name: {                              \
-    LowerUnaryOp(node, rep_type, machine()->Float32##name()); \
-    break;                                                    \
-  }
-      F32X4_UNOP_CASE(Abs)
-      F32X4_UNOP_CASE(Neg)
-      F32X4_UNOP_CASE(Sqrt)
-#undef F32X4_UNOP_CASE
-    case IrOpcode::kF32x4Ceil: {
-      LowerUnaryOp(node, rep_type, machine()->Float32RoundUp().op());
-      break;
-    }
-    case IrOpcode::kF32x4Floor: {
-      LowerUnaryOp(node, rep_type, machine()->Float32RoundDown().op());
-      break;
-    }
-    case IrOpcode::kF32x4Trunc: {
-      LowerUnaryOp(node, rep_type, machine()->Float32RoundTruncate().op());
-      break;
-    }
-    case IrOpcode::kF32x4NearestInt: {
-      LowerUnaryOp(node, rep_type, machine()->Float32RoundTiesEven().op());
-      break;
-    }
-    case IrOpcode::kF32x4RecipApprox:
-    case IrOpcode::kF32x4RecipSqrtApprox: {
-      DCHECK_EQ(1, node->InputCount());
-      Node** rep = GetReplacementsWithType(node->InputAt(0), rep_type);
-      Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-      Node* float_one = graph()->NewNode(common()->Float32Constant(1.0));
-      for (int i = 0; i < num_lanes; ++i) {
-        Node* tmp = rep[i];
-        if (node->opcode() == IrOpcode::kF32x4RecipSqrtApprox) {
-          tmp = graph()->NewNode(machine()->Float32Sqrt(), rep[i]);
-        }
-        rep_node[i] = graph()->NewNode(machine()->Float32Div(), float_one, tmp);
-      }
-      ReplaceNode(node, rep_node, num_lanes);
-      break;
-    }
-    case IrOpcode::kF32x4SConvertI32x4: {
-      LowerUnaryOp(node, SimdType::kInt32x4, machine()->RoundInt32ToFloat32());
-      break;
-    }
-    case IrOpcode::kF32x4UConvertI32x4: {
-      LowerUnaryOp(node, SimdType::kInt32x4, machine()->RoundUint32ToFloat32());
-      break;
-    }
-    case IrOpcode::kF64x2Abs: {
-      LowerUnaryOp(node, rep_type, machine()->Float64Abs());
-      break;
-    }
-    case IrOpcode::kF64x2Neg: {
-      LowerUnaryOp(node, rep_type, machine()->Float64Neg());
-      break;
-    }
-    case IrOpcode::kF64x2Sqrt: {
-      LowerUnaryOp(node, rep_type, machine()->Float64Sqrt());
-      break;
-    }
-    case IrOpcode::kF64x2Add: {
-      LowerBinaryOp(node, rep_type, machine()->Float64Add());
-      break;
-    }
-    case IrOpcode::kF64x2Sub: {
-      LowerBinaryOp(node, rep_type, machine()->Float64Sub());
-      break;
-    }
-    case IrOpcode::kF64x2Mul: {
-      LowerBinaryOp(node, rep_type, machine()->Float64Mul());
-      break;
-    }
-    case IrOpcode::kF64x2Div: {
-      LowerBinaryOp(node, rep_type, machine()->Float64Div());
-      break;
-    }
-    case IrOpcode::kF64x2Min: {
-      LowerBinaryOp(node, rep_type, machine()->Float64Min());
-      break;
-    }
-    case IrOpcode::kF64x2Max: {
-      LowerBinaryOp(node, rep_type, machine()->Float64Max());
-      break;
-    }
-    case IrOpcode::kF64x2Pmin: {
-      LowerFloatPseudoMinMax(node, machine()->Float64LessThan(), false,
-                             rep_type);
-      break;
-    }
-    case IrOpcode::kF64x2Pmax: {
-      LowerFloatPseudoMinMax(node, machine()->Float64LessThan(), true,
-                             rep_type);
-      break;
-    }
-    case IrOpcode::kF64x2Ceil: {
-      LowerUnaryOp(node, rep_type, machine()->Float64RoundUp().op());
-      break;
-    }
-    case IrOpcode::kF64x2Floor: {
-      LowerUnaryOp(node, rep_type, machine()->Float64RoundDown().op());
-      break;
-    }
-    case IrOpcode::kF64x2Trunc: {
-      LowerUnaryOp(node, rep_type, machine()->Float64RoundTruncate().op());
-      break;
-    }
-    case IrOpcode::kF64x2NearestInt: {
-      LowerUnaryOp(node, rep_type, machine()->Float64RoundTiesEven().op());
-      break;
-    }
-    case IrOpcode::kF64x2Splat:
-    case IrOpcode::kF32x4Splat:
-    case IrOpcode::kI64x2Splat:
-    case IrOpcode::kI32x4Splat:
-    case IrOpcode::kI16x8Splat:
-    case IrOpcode::kI8x16Splat: {
-      Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-      Node* val = (HasReplacement(0, node->InputAt(0)))
-                      ? GetReplacements(node->InputAt(0))[0]
-                      : node->InputAt(0);
-
-      // I16 and I8 are placed in Word32 nodes, we need to mask them
-      // accordingly, to account for overflows, then sign extend them.
-      if (node->opcode() == IrOpcode::kI16x8Splat) {
-        val = graph()->NewNode(machine()->SignExtendWord16ToInt32(),
-                               Mask(val, kMask16));
-      } else if (node->opcode() == IrOpcode::kI8x16Splat) {
-        val = graph()->NewNode(machine()->SignExtendWord8ToInt32(),
-                               Mask(val, kMask8));
-      }
-
-      for (int i = 0; i < num_lanes; ++i) {
-        rep_node[i] = val;
-      }
-      ReplaceNode(node, rep_node, num_lanes);
-      break;
-    }
-    case IrOpcode::kF64x2ExtractLane:
-    case IrOpcode::kF32x4ExtractLane:
-    case IrOpcode::kI64x2ExtractLane:
-    case IrOpcode::kI32x4ExtractLane:
-    case IrOpcode::kI16x8ExtractLaneU:
-    case IrOpcode::kI16x8ExtractLaneS:
-    case IrOpcode::kI8x16ExtractLaneU:
-    case IrOpcode::kI8x16ExtractLaneS: {
-      int32_t lane = OpParameter<int32_t>(node->op());
-      Node** rep_node = zone()->NewArray<Node*>(1);
-      rep_node[0] = GetReplacementsWithType(node->InputAt(0), rep_type)[lane];
-
-      // If unsigned, mask the top bits.
-      if (node->opcode() == IrOpcode::kI16x8ExtractLaneU) {
-        rep_node[0] = Mask(rep_node[0], kMask16);
-      } else if (node->opcode() == IrOpcode::kI8x16ExtractLaneU) {
-        rep_node[0] = Mask(rep_node[0], kMask8);
-      }
-
-      ReplaceNode(node, rep_node, 1);
-      break;
-    }
-    case IrOpcode::kF64x2ReplaceLane:
-    case IrOpcode::kF32x4ReplaceLane:
-    case IrOpcode::kI64x2ReplaceLane:
-    case IrOpcode::kI32x4ReplaceLane:
-    case IrOpcode::kI16x8ReplaceLane:
-    case IrOpcode::kI8x16ReplaceLane: {
-      DCHECK_EQ(2, node->InputCount());
-      Node* repNode = node->InputAt(1);
-      int32_t lane = OpParameter<int32_t>(node->op());
-      Node** old_rep_node = GetReplacementsWithType(node->InputAt(0), rep_type);
-      Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-      for (int i = 0; i < num_lanes; ++i) {
-        rep_node[i] = old_rep_node[i];
-      }
-      if (HasReplacement(0, repNode)) {
-        rep_node[lane] = GetReplacements(repNode)[0];
-      } else {
-        rep_node[lane] = repNode;
-      }
-
-      // The replacement nodes for these opcodes are in Word32, and we always
-      // store nodes in sign extended form (and mask to account for overflows.)
-      if (node->opcode() == IrOpcode::kI16x8ReplaceLane) {
-        rep_node[lane] = graph()->NewNode(machine()->SignExtendWord16ToInt32(),
-                                          Mask(rep_node[lane], kMask16));
-      } else if (node->opcode() == IrOpcode::kI8x16ReplaceLane) {
-        rep_node[lane] = graph()->NewNode(machine()->SignExtendWord8ToInt32(),
-                                          Mask(rep_node[lane], kMask8));
-      }
-
-      ReplaceNode(node, rep_node, num_lanes);
-      break;
-    }
-#define COMPARISON_CASE(type, simd_op, lowering_op, invert)                    \
-  case IrOpcode::simd_op: {                                                    \
-    LowerCompareOp(node, SimdType::k##type, machine()->lowering_op(), invert); \
-    break;                                                                     \
-  }
-      COMPARISON_CASE(Float64x2, kF64x2Eq, Float64Equal, false)
-      COMPARISON_CASE(Float64x2, kF64x2Lt, Float64LessThan, false)
-      COMPARISON_CASE(Float64x2, kF64x2Le, Float64LessThanOrEqual, false)
-      COMPARISON_CASE(Float32x4, kF32x4Eq, Float32Equal, false)
-      COMPARISON_CASE(Float32x4, kF32x4Lt, Float32LessThan, false)
-      COMPARISON_CASE(Float32x4, kF32x4Le, Float32LessThanOrEqual, false)
-      COMPARISON_CASE(Float32x4, kF32x4Gt, Float32LessThan, true)
-      COMPARISON_CASE(Float32x4, kF32x4Ge, Float32LessThanOrEqual, true)
-      COMPARISON_CASE(Int64x2, kI64x2Eq, Word64Equal, false)
-      COMPARISON_CASE(Int32x4, kI32x4Eq, Word32Equal, false)
-      COMPARISON_CASE(Int32x4, kI32x4LtS, Int32LessThan, false)
-      COMPARISON_CASE(Int32x4, kI32x4LeS, Int32LessThanOrEqual, false)
-      COMPARISON_CASE(Int32x4, kI32x4GtS, Int32LessThan, true)
-      COMPARISON_CASE(Int32x4, kI32x4GeS, Int32LessThanOrEqual, true)
-      COMPARISON_CASE(Int32x4, kI32x4LtU, Uint32LessThan, false)
-      COMPARISON_CASE(Int32x4, kI32x4LeU, Uint32LessThanOrEqual, false)
-      COMPARISON_CASE(Int32x4, kI32x4GtU, Uint32LessThan, true)
-      COMPARISON_CASE(Int32x4, kI32x4GeU, Uint32LessThanOrEqual, true)
-      COMPARISON_CASE(Int16x8, kI16x8Eq, Word32Equal, false)
-      COMPARISON_CASE(Int16x8, kI16x8LtS, Int32LessThan, false)
-      COMPARISON_CASE(Int16x8, kI16x8LeS, Int32LessThanOrEqual, false)
-      COMPARISON_CASE(Int16x8, kI16x8GtS, Int32LessThan, true)
-      COMPARISON_CASE(Int16x8, kI16x8GeS, Int32LessThanOrEqual, true)
-      COMPARISON_CASE(Int16x8, kI16x8LtU, Uint32LessThan, false)
-      COMPARISON_CASE(Int16x8, kI16x8LeU, Uint32LessThanOrEqual, false)
-      COMPARISON_CASE(Int16x8, kI16x8GtU, Uint32LessThan, true)
-      COMPARISON_CASE(Int16x8, kI16x8GeU, Uint32LessThanOrEqual, true)
-      COMPARISON_CASE(Int8x16, kI8x16Eq, Word32Equal, false)
-      COMPARISON_CASE(Int8x16, kI8x16LtS, Int32LessThan, false)
-      COMPARISON_CASE(Int8x16, kI8x16LeS, Int32LessThanOrEqual, false)
-      COMPARISON_CASE(Int8x16, kI8x16GtS, Int32LessThan, true)
-      COMPARISON_CASE(Int8x16, kI8x16GeS, Int32LessThanOrEqual, true)
-      COMPARISON_CASE(Int8x16, kI8x16LtU, Uint32LessThan, false)
-      COMPARISON_CASE(Int8x16, kI8x16LeU, Uint32LessThanOrEqual, false)
-      COMPARISON_CASE(Int8x16, kI8x16GtU, Uint32LessThan, true)
-      COMPARISON_CASE(Int8x16, kI8x16GeU, Uint32LessThanOrEqual, true)
-#undef COMPARISON_CASE
-    case IrOpcode::kF64x2Ne: {
-      LowerNotEqual(node, SimdType::kFloat64x2, machine()->Float64Equal());
-      break;
-    }
-    case IrOpcode::kF32x4Ne: {
-      LowerNotEqual(node, SimdType::kFloat32x4, machine()->Float32Equal());
-      break;
-    }
-    case IrOpcode::kI64x2Ne: {
-      LowerNotEqual(node, SimdType::kInt64x2, machine()->Word64Equal());
-      break;
-    }
-    case IrOpcode::kI32x4Ne: {
-      LowerNotEqual(node, SimdType::kInt32x4, machine()->Word32Equal());
-      break;
-    }
-    case IrOpcode::kI16x8Ne: {
-      LowerNotEqual(node, SimdType::kInt16x8, machine()->Word32Equal());
-      break;
-    }
-    case IrOpcode::kI8x16Ne: {
-      LowerNotEqual(node, SimdType::kInt8x16, machine()->Word32Equal());
-      break;
-    }
-    case IrOpcode::kS128Select: {
-      DCHECK_EQ(3, node->InputCount());
-      Node** boolean_input =
-          GetReplacementsWithType(node->InputAt(0), rep_type);
-      Node** rep_left = GetReplacementsWithType(node->InputAt(1), rep_type);
-      Node** rep_right = GetReplacementsWithType(node->InputAt(2), rep_type);
-      Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-      for (int i = 0; i < num_lanes; ++i) {
-        Node* tmp1 =
-            graph()->NewNode(machine()->Word32Xor(), rep_left[i], rep_right[i]);
-        Node* tmp2 =
-            graph()->NewNode(machine()->Word32And(), boolean_input[i], tmp1);
-        rep_node[i] =
-            graph()->NewNode(machine()->Word32Xor(), rep_right[i], tmp2);
-      }
-      ReplaceNode(node, rep_node, num_lanes);
-      break;
-    }
-    case IrOpcode::kI8x16Swizzle: {
-      DCHECK_EQ(2, node->InputCount());
-      Node** rep_left = GetReplacementsWithType(node->InputAt(0), rep_type);
-      Node** indices = GetReplacementsWithType(node->InputAt(1), rep_type);
-      Node** rep_nodes = zone()->NewArray<Node*>(num_lanes);
-      Node* stack_slot = graph()->NewNode(
-          machine()->StackSlot(MachineRepresentation::kSimd128));
-
-      // Push all num_lanes values into stack slot.
-      const Operator* store_op = machine()->Store(
-          StoreRepresentation(MachineRepresentation::kWord8, kNoWriteBarrier));
-      Node* effect_input = graph()->start();
-      for (int i = num_lanes - 1; i >= 0; i--) {
-        // We want all the stores to happen first before any of the loads
-        // below, so connect them via effect edge from i-1 to i.
-        Node* store =
-            graph()->NewNode(store_op, stack_slot, mcgraph_->Int32Constant(i),
-                             rep_left[i], effect_input, graph()->start());
-        effect_input = store;
-      }
-
-      for (int i = num_lanes - 1; i >= 0; i--) {
-        // Only select lane when index is < num_lanes, otherwise write 0 to
-        // lane. Use Uint32 to take care of negative indices.
-        Diamond d(graph(), common(),
-                  graph()->NewNode(machine()->Uint32LessThan(), indices[i],
-                                   mcgraph_->Int32Constant(num_lanes)));
-
-        Node* load =
-            graph()->NewNode(machine()->Load(LoadRepresentation::Uint8()),
-                             stack_slot, indices[i], effect_input, d.if_true);
-
-        rep_nodes[i] = d.Phi(MachineRepresentation::kWord8, load,
-                             mcgraph_->Int32Constant(0));
-      }
-
-      ReplaceNode(node, rep_nodes, num_lanes);
-      break;
-    }
-    case IrOpcode::kI8x16Shuffle: {
-      DCHECK_EQ(2, node->InputCount());
-      S128ImmediateParameter shuffle = S128ImmediateParameterOf(node->op());
-      Node** rep_left = GetReplacementsWithType(node->InputAt(0), rep_type);
-      Node** rep_right = GetReplacementsWithType(node->InputAt(1), rep_type);
-      Node** rep_node = zone()->NewArray<Node*>(16);
-      for (int i = 0; i < 16; i++) {
-        int lane = shuffle[i];
-        rep_node[i] = lane < 16 ? rep_left[lane] : rep_right[lane - 16];
-      }
-      ReplaceNode(node, rep_node, 16);
-      break;
-    }
-    case IrOpcode::kV128AnyTrue: {
-      DCHECK_EQ(1, node->InputCount());
-      // AnyTrue always returns a I32x4, and can work with inputs of any shape,
-      // but we still need GetReplacementsWithType if input is float.
-      DCHECK_EQ(ReplacementType(node), SimdType::kInt32x4);
-      Node** reps = GetReplacementsWithType(node->InputAt(0), rep_type);
-      Node** rep_node = zone()->NewArray<Node*>(1);
-      Node* true_node = mcgraph_->Int32Constant(1);
-      Node* zero = mcgraph_->Int32Constant(0);
-      Node* tmp_result = zero;
-      for (int i = 0; i < num_lanes; ++i) {
-        Diamond d(graph(), common(),
-                  graph()->NewNode(machine()->Word32Equal(), reps[i], zero));
-        tmp_result =
-            d.Phi(MachineRepresentation::kWord32, tmp_result, true_node);
-      }
-      rep_node[0] = tmp_result;
-      ReplaceNode(node, rep_node, 1);
-      break;
-    }
-    case IrOpcode::kI64x2AllTrue: {
-      LowerAllTrueOp(node, SimdType::kInt64x2);
-      break;
-    }
-    case IrOpcode::kI32x4AllTrue: {
-      LowerAllTrueOp(node, SimdType::kInt32x4);
-      break;
-    }
-    case IrOpcode::kI16x8AllTrue: {
-      LowerAllTrueOp(node, SimdType::kInt16x8);
-      break;
-    }
-    case IrOpcode::kI8x16AllTrue: {
-      LowerAllTrueOp(node, SimdType::kInt8x16);
-      break;
-    }
-    case IrOpcode::kI8x16BitMask: {
-      LowerBitMaskOp(node, rep_type, 7);
-      break;
-    }
-    case IrOpcode::kI16x8BitMask: {
-      LowerBitMaskOp(node, rep_type, 15);
-      break;
-    }
-    case IrOpcode::kI32x4BitMask: {
-      LowerBitMaskOp(node, rep_type, 31);
-      break;
-    }
-    case IrOpcode::kI8x16RoundingAverageU:
-    case IrOpcode::kI16x8RoundingAverageU: {
-      DCHECK_EQ(2, node->InputCount());
-      Node** rep_left = GetReplacementsWithType(node->InputAt(0), rep_type);
-      Node** rep_right = GetReplacementsWithType(node->InputAt(1), rep_type);
-      int num_lanes = NumLanes(rep_type);
-      Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-      // Nodes are stored signed, so mask away the top bits.
-      // rounding_average(left, right) = (left + right + 1) >> 1
-      const int bit_mask = num_lanes == 16 ? kMask8 : kMask16;
-      for (int i = 0; i < num_lanes; ++i) {
-        Node* mask_left = graph()->NewNode(machine()->Word32And(), rep_left[i],
-                                           mcgraph_->Int32Constant(bit_mask));
-        Node* mask_right =
-            graph()->NewNode(machine()->Word32And(), rep_right[i],
-                             mcgraph_->Int32Constant(bit_mask));
-        Node* left_plus_right_plus_one = graph()->NewNode(
-            machine()->Int32Add(),
-            graph()->NewNode(machine()->Int32Add(), mask_left, mask_right),
-            mcgraph_->Int32Constant(1));
-        rep_node[i] =
-            graph()->NewNode(machine()->Word32Shr(), left_plus_right_plus_one,
-                             mcgraph_->Int32Constant(1));
-      }
-      ReplaceNode(node, rep_node, num_lanes);
-      break;
-    }
-#define LOWER_EXT_MUL(OP, MULTIPLY, INPUT_TYPE, LOW, SIGNED)                 \
-  case IrOpcode::OP: {                                                       \
-    LowerExtMul(node, machine()->MULTIPLY(), rep_type, SimdType::INPUT_TYPE, \
-                LOW, SIGNED);                                                \
-    break;                                                                   \
-  }
-      LOWER_EXT_MUL(kI16x8ExtMulLowI8x16S, Int32Mul, kInt8x16, true, true)
-      LOWER_EXT_MUL(kI16x8ExtMulLowI8x16U, Int32Mul, kInt8x16, true, false)
-      LOWER_EXT_MUL(kI16x8ExtMulHighI8x16S, Int32Mul, kInt8x16, false, true)
-      LOWER_EXT_MUL(kI16x8ExtMulHighI8x16U, Int32Mul, kInt8x16, false, false)
-      LOWER_EXT_MUL(kI32x4ExtMulLowI16x8S, Int32Mul, kInt16x8, true, true)
-      LOWER_EXT_MUL(kI32x4ExtMulLowI16x8U, Int32Mul, kInt16x8, true, false)
-      LOWER_EXT_MUL(kI32x4ExtMulHighI16x8S, Int32Mul, kInt16x8, false, true)
-      LOWER_EXT_MUL(kI32x4ExtMulHighI16x8U, Int32Mul, kInt16x8, false, false)
-      LOWER_EXT_MUL(kI64x2ExtMulLowI32x4S, Int64Mul, kInt32x4, true, true)
-      LOWER_EXT_MUL(kI64x2ExtMulLowI32x4U, Int64Mul, kInt32x4, true, false)
-      LOWER_EXT_MUL(kI64x2ExtMulHighI32x4S, Int64Mul, kInt32x4, false, true)
-      LOWER_EXT_MUL(kI64x2ExtMulHighI32x4U, Int64Mul, kInt32x4, false, false)
-    default: {
-      DefaultLowering(node);
-    }
-  }
-}
-
-Node* SimdScalarLowering::ExtendNode(Node* node, SimdType rep_type,
-                                     bool is_signed) {
-  if (rep_type == SimdType::kInt8x16 && !is_signed) {
-    node = Mask(node, kMask8);
-  } else if (rep_type == SimdType::kInt16x8 && !is_signed) {
-    node = Mask(node, kMask16);
-  } else if (rep_type == SimdType::kInt32x4) {
-    if (is_signed) {
-      node = graph()->NewNode(machine()->SignExtendWord32ToInt64(), node);
-    } else {
-      node = graph()->NewNode(machine()->ChangeUint32ToUint64(), node);
-    }
-  }
-  return node;
-}
-
-void SimdScalarLowering::LowerExtMul(Node* node, const Operator* multiply,
-                                     SimdType output_type, SimdType input_type,
-                                     bool low, bool is_signed) {
-  DCHECK_EQ(2, node->InputCount());
-  int num_lanes = NumLanes(output_type);
-  Node** rep_left = GetReplacementsWithType(node->InputAt(0), input_type);
-  Node** rep_right = GetReplacementsWithType(node->InputAt(1), input_type);
-  int start_index = low ? 0 : num_lanes;
-  Node** rep_node = zone()->NewArray<Node*>(num_lanes);
-  for (int i = 0; i < num_lanes; i++) {
-    Node* left = ExtendNode(rep_left[start_index + i], input_type, is_signed);
-    Node* right = ExtendNode(rep_right[start_index + i], input_type, is_signed);
-    rep_node[i] = graph()->NewNode(multiply, left, right);
-  }
-  ReplaceNode(node, rep_node, num_lanes);
-}
-
-bool SimdScalarLowering::DefaultLowering(Node* node) {
-  bool something_changed = false;
-  for (int i = NodeProperties::PastValueIndex(node) - 1; i >= 0; i--) {
-    Node* input = node->InputAt(i);
-    if (HasReplacement(0, input)) {
-      something_changed = true;
-      node->ReplaceInput(i, GetReplacements(input)[0]);
-    }
-    if (ReplacementCount(input) > 1 && HasReplacement(1, input)) {
-      something_changed = true;
-      for (int j = 1; j < ReplacementCount(input); ++j) {
-        node->InsertInput(zone(), i + j, GetReplacements(input)[j]);
-      }
-    }
-  }
-  return something_changed;
-}
-
-void SimdScalarLowering::ReplaceNode(Node* old, Node** new_nodes, int count) {
-  replacements_[old->id()].node = zone()->NewArray<Node*>(count);
-  for (int i = 0; i < count; ++i) {
-    replacements_[old->id()].node[i] = new_nodes[i];
-  }
-  replacements_[old->id()].num_replacements = count;
-}
-
-bool SimdScalarLowering::HasReplacement(size_t index, Node* node) {
-  return replacements_[node->id()].node != nullptr &&
-         replacements_[node->id()].node[index] != nullptr;
-}
-
-SimdScalarLowering::SimdType SimdScalarLowering::ReplacementType(Node* node) {
-  return replacements_[node->id()].type;
-}
-
-Node** SimdScalarLowering::GetReplacements(Node* node) {
-  Node** result = replacements_[node->id()].node;
-  DCHECK(result);
-  return result;
-}
-
-int SimdScalarLowering::ReplacementCount(Node* node) {
-  return replacements_[node->id()].num_replacements;
-}
-
-void SimdScalarLowering::Int32ToFloat32(Node** replacements, Node** result) {
-  for (int i = 0; i < kNumLanes32; ++i) {
-    if (replacements[i] != nullptr) {
-      result[i] =
-          graph()->NewNode(machine()->BitcastInt32ToFloat32(), replacements[i]);
-    } else {
-      result[i] = nullptr;
-    }
-  }
-}
-
-void SimdScalarLowering::Int64ToFloat64(Node** replacements, Node** result) {
-  for (int i = 0; i < kNumLanes64; ++i) {
-    if (replacements[i] != nullptr) {
-      result[i] =
-          graph()->NewNode(machine()->BitcastInt64ToFloat64(), replacements[i]);
-    } else {
-      result[i] = nullptr;
-    }
-  }
-}
-
-void SimdScalarLowering::Float64ToInt64(Node** replacements, Node** result) {
-  for (int i = 0; i < kNumLanes64; ++i) {
-    if (replacements[i] != nullptr) {
-      result[i] =
-          graph()->NewNode(machine()->BitcastFloat64ToInt64(), replacements[i]);
-    } else {
-      result[i] = nullptr;
-    }
-  }
-}
-
-void SimdScalarLowering::Float32ToInt32(Node** replacements, Node** result) {
-  for (int i = 0; i < kNumLanes32; ++i) {
-    if (replacements[i] != nullptr) {
-      result[i] =
-          graph()->NewNode(machine()->BitcastFloat32ToInt32(), replacements[i]);
-    } else {
-      result[i] = nullptr;
-    }
-  }
-}
-
-void SimdScalarLowering::Int64ToInt32(Node** replacements, Node** result) {
-  const int num_ints = sizeof(int64_t) / sizeof(int32_t);
-  const int bit_size = sizeof(int32_t) * 8;
-  const Operator* truncate = machine()->TruncateInt64ToInt32();
-
-  for (int i = 0; i < kNumLanes64; i++) {
-    if (replacements[i] != nullptr) {
-      for (int j = 0; j < num_ints; j++) {
-        result[num_ints * i + j] = graph()->NewNode(
-            truncate, graph()->NewNode(machine()->Word64Sar(), replacements[i],
-                                       mcgraph_->Int32Constant(j * bit_size)));
-      }
-    } else {
-      for (int j = 0; j < num_ints; j++) {
-        result[num_ints * i + j] = nullptr;
-      }
-    }
-  }
-}
-
-template <typename T>
-void SimdScalarLowering::Int32ToSmallerInt(Node** replacements, Node** result) {
-  const int num_ints = sizeof(int32_t) / sizeof(T);
-  const int bit_size = sizeof(T) * 8;
-  const Operator* sign_extend;
-  switch (sizeof(T)) {
-    case 1:
-      sign_extend = machine()->SignExtendWord8ToInt32();
-      break;
-    case 2:
-      sign_extend = machine()->SignExtendWord16ToInt32();
-      break;
-    default:
-      UNREACHABLE();
-  }
-
-  for (int i = 0; i < kNumLanes32; i++) {
-    if (replacements[i] != nullptr) {
-      for (int j = 0; j < num_ints; j++) {
-        result[num_ints * i + j] = graph()->NewNode(
-            sign_extend,
-            graph()->NewNode(machine()->Word32Shr(), replacements[i],
-                             mcgraph_->Int32Constant(j * bit_size)));
-      }
-    } else {
-      for (int j = 0; j < num_ints; j++) {
-        result[num_ints * i + j] = nullptr;
-      }
-    }
-  }
-}
-
-template <typename T>
-void SimdScalarLowering::SmallerIntToInt32(Node** replacements, Node** result) {
-  const int num_ints = sizeof(int32_t) / sizeof(T);
-  const int bit_size = sizeof(T) * 8;
-  const int bit_mask = (1 << bit_size) - 1;
-
-  for (int i = 0; i < kNumLanes32; ++i) {
-    result[i] = mcgraph_->Int32Constant(0);
-    for (int j = 0; j < num_ints; j++) {
-      if (replacements[num_ints * i + j] != nullptr) {
-        Node* clean_bits = graph()->NewNode(machine()->Word32And(),
-                                            replacements[num_ints * i + j],
-                                            mcgraph_->Int32Constant(bit_mask));
-        Node* shift = graph()->NewNode(machine()->Word32Shl(), clean_bits,
-                                       mcgraph_->Int32Constant(j * bit_size));
-        result[i] = graph()->NewNode(machine()->Word32Or(), result[i], shift);
-      }
-    }
-  }
-}
-
-void SimdScalarLowering::Int32ToInt64(Node** replacements, Node** result) {
-  const int num_ints = sizeof(int64_t) / sizeof(int32_t);
-
-  for (int i = 0; i < kNumLanes64; i++) {
-    Node* i64 = graph()->NewNode(machine()->ChangeUint32ToUint64(),
-                                 replacements[num_ints * i + 1]);
-    Node* high = graph()->NewNode(machine()->Word64Shl(), i64,
-                                  mcgraph_->Int32Constant(32));
-    Node* i64_low = graph()->NewNode(machine()->ChangeUint32ToUint64(),
-                                     replacements[num_ints * i]);
-    result[i] = graph()->NewNode(machine()->Word64Or(), high, i64_low);
-  }
-}
-
-Node** SimdScalarLowering::GetReplacementsWithType(Node* node, SimdType type) {
-  // Operations like extract lane, bitmask, any_true, all_true replaces a SIMD
-  // node with a scalar. Those won't be correctly handled here. They should be
-  // special cased and replaced with the appropriate scalar.
-  DCHECK_LT(1, ReplacementCount(node));
-
-  Node** replacements = GetReplacements(node);
-  if (type == ReplacementType(node)) {
-    return replacements;
-  }
-
-  int num_lanes = NumLanes(type);
-  Node** result = zone()->NewArray<Node*>(num_lanes);
-
-  switch (type) {
-    case SimdType::kInt64x2: {
-      switch (ReplacementType(node)) {
-        case SimdType::kInt64x2: {
-          UNREACHABLE();
-        }
-        case SimdType::kInt32x4: {
-          Int32ToInt64(replacements, result);
-          break;
-        }
-        case SimdType::kInt16x8: {
-          Node** to_int32 = zone()->NewArray<Node*>(kNumLanes32);
-          SmallerIntToInt32<int16_t>(replacements, to_int32);
-          Int32ToInt64(to_int32, result);
-          break;
-        }
-        case SimdType::kInt8x16: {
-          Node** to_int32 = zone()->NewArray<Node*>(kNumLanes32);
-          SmallerIntToInt32<int8_t>(replacements, to_int32);
-          Int32ToInt64(to_int32, result);
-          break;
-        }
-        case SimdType::kFloat64x2: {
-          Float64ToInt64(replacements, result);
-          break;
-        }
-        case SimdType::kFloat32x4: {
-          Node** to_int32 = zone()->NewArray<Node*>(kNumLanes32);
-          Float32ToInt32(replacements, to_int32);
-          Int32ToInt64(to_int32, result);
-          break;
-        }
-      }
-      break;
-    }
-    case SimdType::kInt32x4: {
-      switch (ReplacementType(node)) {
-        case SimdType::kInt64x2: {
-          Int64ToInt32(replacements, result);
-          break;
-        }
-        case SimdType::kInt32x4: {
-          UNREACHABLE();
-        }
-        case SimdType::kInt16x8: {
-          SmallerIntToInt32<int16_t>(replacements, result);
-          break;
-        }
-        case SimdType::kInt8x16: {
-          SmallerIntToInt32<int8_t>(replacements, result);
-          break;
-        }
-        case SimdType::kFloat64x2: {
-          Node** float64_to_int64 = zone()->NewArray<Node*>(kNumLanes64);
-          Float64ToInt64(replacements, float64_to_int64);
-          Int64ToInt32(float64_to_int64, result);
-          break;
-        }
-        case SimdType::kFloat32x4: {
-          Float32ToInt32(replacements, result);
-          break;
-        }
-      }
-      break;
-    }
-    case SimdType::kInt16x8: {
-      switch (ReplacementType(node)) {
-        case SimdType::kInt64x2: {
-          Node** to_int32 = zone()->NewArray<Node*>(kNumLanes32);
-          Int64ToInt32(replacements, to_int32);
-          Int32ToSmallerInt<int16_t>(to_int32, result);
-          break;
-        }
-        case SimdType::kInt32x4: {
-          Int32ToSmallerInt<int16_t>(replacements, result);
-          break;
-        }
-        case SimdType::kInt16x8: {
-          UNREACHABLE();
-        }
-        case SimdType::kInt8x16: {
-          Node** to_int32 = zone()->NewArray<Node*>(kNumLanes32);
-          SmallerIntToInt32<int8_t>(replacements, to_int32);
-          Int32ToSmallerInt<int16_t>(to_int32, result);
-          break;
-        }
-        case SimdType::kFloat64x2: {
-          Node** to_int64 = zone()->NewArray<Node*>(kNumLanes64);
-          Node** to_int32 = zone()->NewArray<Node*>(kNumLanes32);
-          Float64ToInt64(replacements, to_int64);
-          Int64ToInt32(to_int64, to_int32);
-          Int32ToSmallerInt<int16_t>(to_int32, result);
-          break;
-        }
-        case SimdType::kFloat32x4: {
-          Node** float32_to_int32 = zone()->NewArray<Node*>(kNumLanes32);
-          Float32ToInt32(replacements, float32_to_int32);
-          Int32ToSmallerInt<int16_t>(float32_to_int32, result);
-          break;
-        }
-      }
-      break;
-    }
-    case SimdType::kInt8x16: {
-      switch (ReplacementType(node)) {
-        case SimdType::kInt64x2: {
-          Node** int64_to_int32 = zone()->NewArray<Node*>(kNumLanes32);
-          Int64ToInt32(replacements, int64_to_int32);
-          Int32ToSmallerInt<int8_t>(int64_to_int32, result);
-          break;
-        }
-        case SimdType::kInt32x4: {
-          Int32ToSmallerInt<int8_t>(replacements, result);
-          break;
-        }
-        case SimdType::kInt16x8: {
-          Node** int16_to_int32 = zone()->NewArray<Node*>(kNumLanes32);
-          SmallerIntToInt32<int16_t>(replacements, int16_to_int32);
-          Int32ToSmallerInt<int8_t>(int16_to_int32, result);
-          break;
-        }
-        case SimdType::kInt8x16: {
-          UNREACHABLE();
-        }
-        case SimdType::kFloat64x2: {
-          Node** to_int64 = zone()->NewArray<Node*>(kNumLanes64);
-          Node** to_int32 = zone()->NewArray<Node*>(kNumLanes32);
-          Float64ToInt64(replacements, to_int64);
-          Int64ToInt32(to_int64, to_int32);
-          Int32ToSmallerInt<int8_t>(to_int32, result);
-          break;
-        }
-        case SimdType::kFloat32x4: {
-          Node** float32_to_int32 = zone()->NewArray<Node*>(kNumLanes32);
-          Float32ToInt32(replacements, float32_to_int32);
-          Int32ToSmallerInt<int8_t>(float32_to_int32, result);
-          break;
-        }
-      }
-      break;
-    }
-    case SimdType::kFloat64x2: {
-      switch (ReplacementType(node)) {
-        case SimdType::kInt64x2: {
-          Int64ToFloat64(replacements, result);
-          break;
-        }
-        case SimdType::kInt32x4: {
-          Node** int32_to_int64 = zone()->NewArray<Node*>(kNumLanes64);
-          Int32ToInt64(replacements, int32_to_int64);
-          Int64ToFloat64(int32_to_int64, result);
-          break;
-        }
-        case SimdType::kInt16x8: {
-          Node** to_int32 = zone()->NewArray<Node*>(kNumLanes32);
-          Node** to_int64 = zone()->NewArray<Node*>(kNumLanes64);
-          SmallerIntToInt32<int16_t>(replacements, to_int32);
-          Int32ToInt64(to_int32, to_int64);
-          Int64ToFloat64(to_int64, result);
-          break;
-        }
-        case SimdType::kInt8x16: {
-          Node** to_int32 = zone()->NewArray<Node*>(kNumLanes32);
-          Node** to_int64 = zone()->NewArray<Node*>(kNumLanes64);
-          SmallerIntToInt32<int8_t>(replacements, to_int32);
-          Int32ToInt64(to_int32, to_int64);
-          Int64ToFloat64(to_int64, result);
-          break;
-        }
-        case SimdType::kFloat64x2: {
-          UNREACHABLE();
-        }
-        case SimdType::kFloat32x4: {
-          Node** to_int32 = zone()->NewArray<Node*>(kNumLanes32);
-          Node** to_int64 = zone()->NewArray<Node*>(kNumLanes64);
-          Float32ToInt32(replacements, to_int32);
-          Int32ToInt64(to_int32, to_int64);
-          Int64ToFloat64(to_int64, result);
-          break;
-        }
-      }
-      break;
-    }
-    case SimdType::kFloat32x4: {
-      switch (ReplacementType(node)) {
-        case SimdType::kInt64x2: {
-          Node** to_int32 = zone()->NewArray<Node*>(kNumLanes32);
-          Int64ToInt32(replacements, to_int32);
-          Int32ToFloat32(to_int32, result);
-          break;
-        }
-        case SimdType::kInt32x4: {
-          Int32ToFloat32(replacements, result);
-          break;
-        }
-        case SimdType::kInt16x8: {
-          Node** to_int32 = zone()->NewArray<Node*>(kNumLanes32);
-          SmallerIntToInt32<int16_t>(replacements, to_int32);
-          Int32ToFloat32(to_int32, result);
-          break;
-        }
-        case SimdType::kInt8x16: {
-          SmallerIntToInt32<int8_t>(replacements, result);
-          Int32ToFloat32(result, result);
-          break;
-        }
-        case SimdType::kFloat64x2: {
-          Node** float64_to_int64 = zone()->NewArray<Node*>(kNumLanes64);
-          Node** int64_to_int32 = zone()->NewArray<Node*>(kNumLanes32);
-          Float64ToInt64(replacements, float64_to_int64);
-          Int64ToInt32(float64_to_int64, int64_to_int32);
-          Int32ToFloat32(int64_to_int32, result);
-          break;
-        }
-        case SimdType::kFloat32x4: {
-          UNREACHABLE();
-        }
-      }
-      break;
-    }
-  }
-  return result;
-}
-
-void SimdScalarLowering::PreparePhiReplacement(Node* phi) {
-  MachineRepresentation rep = PhiRepresentationOf(phi->op());
-  if (rep == MachineRepresentation::kSimd128) {
-    // We have to create the replacements for a phi node before we actually
-    // lower the phi to break potential cycles in the graph. The replacements of
-    // input nodes do not exist yet, so we use a placeholder node to pass the
-    // graph verifier.
-    int value_count = phi->op()->ValueInputCount();
-    SimdType type = ReplacementType(phi);
-    int num_lanes = NumLanes(type);
-    Node*** inputs_rep = zone()->NewArray<Node**>(num_lanes);
-    for (int i = 0; i < num_lanes; ++i) {
-      inputs_rep[i] = zone()->NewArray<Node*>(value_count + 1);
-      inputs_rep[i][value_count] = NodeProperties::GetControlInput(phi, 0);
-    }
-    for (int i = 0; i < value_count; ++i) {
-      for (int j = 0; j < num_lanes; ++j) {
-        inputs_rep[j][i] = placeholder_;
-      }
-    }
-    Node** rep_nodes = zone()->NewArray<Node*>(num_lanes);
-    for (int i = 0; i < num_lanes; ++i) {
-      rep_nodes[i] = graph()->NewNode(
-          common()->Phi(MachineTypeFrom(type).representation(), value_count),
-          value_count + 1, inputs_rep[i], false);
-    }
-    ReplaceNode(phi, rep_nodes, num_lanes);
-  }
-}
-}  // namespace compiler
-}  // namespace internal
-}  // namespace v8
diff --git a/chromium/v8/src/compiler/simd-scalar-lowering.h b/chromium/v8/src/compiler/simd-scalar-lowering.h
deleted file mode 100644
index d67c389d16d..00000000000
--- a/chromium/v8/src/compiler/simd-scalar-lowering.h
+++ /dev/null
@@ -1,150 +0,0 @@
-// Copyright 2016 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef V8_COMPILER_SIMD_SCALAR_LOWERING_H_
-#define V8_COMPILER_SIMD_SCALAR_LOWERING_H_
-
-#include "src/compiler/common-operator.h"
-#include "src/compiler/diamond.h"
-#include "src/compiler/graph.h"
-#include "src/compiler/machine-graph.h"
-#include "src/compiler/machine-operator.h"
-#include "src/compiler/node-marker.h"
-#include "src/compiler/simplified-operator.h"
-#include "src/zone/zone-containers.h"
-
-namespace v8 {
-namespace internal {
-
-template <typename T>
-class Signature;
-
-namespace compiler {
-
-class SimdScalarLowering {
- public:
-  SimdScalarLowering(MachineGraph* mcgraph,
-                     SimplifiedOperatorBuilder* simplified,
-                     Signature<MachineRepresentation>* signature);
-
-  void LowerGraph();
-
-  int GetParameterCountAfterLowering();
-
- private:
-  enum class State : uint8_t { kUnvisited, kOnStack, kVisited };
-
-  enum class SimdType : uint8_t {
-    kFloat64x2,
-    kFloat32x4,
-    kInt64x2,
-    kInt32x4,
-    kInt16x8,
-    kInt8x16
-  };
-
-#if defined(V8_TARGET_BIG_ENDIAN)
-  static constexpr int kLaneOffsets[16] = {15, 14, 13, 12, 11, 10, 9, 8,
-                                           7,  6,  5,  4,  3,  2,  1, 0};
-#else
-  static constexpr int kLaneOffsets[16] = {0, 1, 2,  3,  4,  5,  6,  7,
-                                           8, 9, 10, 11, 12, 13, 14, 15};
-#endif
-  struct Replacement {
-    Node** node = nullptr;
-    SimdType type;  // represents output type
-    int num_replacements = 0;
-  };
-
-  struct NodeState {
-    Node* node;
-    int input_index;
-  };
-
-  Zone* zone() const { return mcgraph_->zone(); }
-  Graph* graph() const { return mcgraph_->graph(); }
-  MachineOperatorBuilder* machine() const { return mcgraph_->machine(); }
-  CommonOperatorBuilder* common() const { return mcgraph_->common(); }
-  SimplifiedOperatorBuilder* simplified() const { return simplified_; }
-  Signature<MachineRepresentation>* signature() const { return signature_; }
-
-  void LowerNode(Node* node);
-  bool DefaultLowering(Node* node);
-
-  int NumLanes(SimdType type);
-  void ReplaceNode(Node* old, Node** new_nodes, int count);
-  bool HasReplacement(size_t index, Node* node);
-  Node** GetReplacements(Node* node);
-  int ReplacementCount(Node* node);
-  void Float64ToInt64(Node** replacements, Node** result);
-  void Float32ToInt32(Node** replacements, Node** result);
-  void Int32ToFloat32(Node** replacements, Node** result);
-  void Int64ToFloat64(Node** replacements, Node** result);
-  void Int64ToInt32(Node** replacements, Node** result);
-  template <typename T>
-  void Int32ToSmallerInt(Node** replacements, Node** result);
-  template <typename T>
-  void SmallerIntToInt32(Node** replacements, Node** result);
-  void Int32ToInt64(Node** replacements, Node** result);
-  Node** GetReplacementsWithType(Node* node, SimdType type);
-  SimdType ReplacementType(Node* node);
-  void PreparePhiReplacement(Node* phi);
-  void SetLoweredType(Node* node, Node* output);
-  void GetIndexNodes(Node* index, Node** new_indices, SimdType type);
-  void LowerLoadOp(Node* node, SimdType type);
-  void LowerLoadTransformOp(Node* node, SimdType type);
-  void LowerStoreOp(Node* node);
-  void LowerBinaryOp(Node* node, SimdType input_rep_type, const Operator* op,
-                     bool not_horizontal = true);
-  Node* ConstructPhiForComparison(Diamond d, SimdType rep_type, int true_value,
-                                  int false_value);
-  void LowerCompareOp(Node* node, SimdType input_rep_type, const Operator* op,
-                      bool invert_inputs = false);
-  Node* FixUpperBits(Node* input, int32_t shift);
-  void LowerBinaryOpForSmallInt(Node* node, SimdType input_rep_type,
-                                const Operator* op, bool not_horizontal = true);
-  Node* Mask(Node* input, int32_t mask);
-  void LowerSaturateBinaryOp(Node* node, SimdType input_rep_type,
-                             const Operator* op, bool is_signed);
-  void LowerUnaryOp(Node* node, SimdType input_rep_type, const Operator* op);
-  void LowerIntMinMax(Node* node, const Operator* op, bool is_max,
-                      SimdType type);
-  void LowerConvertFromFloat(Node* node, bool is_signed);
-  void LowerConvertFromInt(Node* node, SimdType input_rep_type,
-                           SimdType output_rep_type, bool is_signed,
-                           int start_index);
-  void LowerPack(Node* node, SimdType input_rep_type, SimdType output_rep_type,
-                 bool is_signed);
-  void LowerShiftOp(Node* node, SimdType type);
-  Node* BuildF64Trunc(Node* input);
-  void LowerNotEqual(Node* node, SimdType input_rep_type, const Operator* op);
-  MachineType MachineTypeFrom(SimdType simdType);
-  void LowerBitMaskOp(Node* node, SimdType rep_type, int msb_index);
-  void LowerAllTrueOp(Node* node, SimdType rep_type);
-  void LowerFloatPseudoMinMax(Node* node, const Operator* op, bool is_max,
-                              SimdType type);
-  void LowerExtMul(Node* node, const Operator* op, SimdType output_type,
-                   SimdType input_type, bool low, bool is_signed);
-
-  // Extends node, which is a lowered node of type rep_type, e.g. int8, int16,
-  // int32 to a 32-bit or 64-bit node. node should be a lowered node (i.e. not a
-  // SIMD node). The assumption here is that small ints are stored sign
-  // extended.
-  Node* ExtendNode(Node* node, SimdType rep_type, bool is_signed);
-
-  MachineGraph* const mcgraph_;
-  SimplifiedOperatorBuilder* const simplified_;
-  NodeMarker<State> state_;
-  ZoneDeque<NodeState> stack_;
-  Replacement* replacements_;
-  Signature<MachineRepresentation>* signature_;
-  Node* placeholder_;
-  int parameter_count_after_lowering_;
-};
-
-}  // namespace compiler
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_COMPILER_SIMD_SCALAR_LOWERING_H_
diff --git a/chromium/v8/src/compiler/simplified-lowering.cc b/chromium/v8/src/compiler/simplified-lowering.cc
index d5389df6ac8..75de8ecc421 100644
--- a/chromium/v8/src/compiler/simplified-lowering.cc
+++ b/chromium/v8/src/compiler/simplified-lowering.cc
@@ -101,18 +101,20 @@ MachineRepresentation MachineRepresentationFromArrayType(
 }
 
 UseInfo CheckedUseInfoAsWord32FromHint(
-    NumberOperationHint hint, const FeedbackSource& feedback = FeedbackSource(),
-    IdentifyZeros identify_zeros = kDistinguishZeros) {
+    NumberOperationHint hint, IdentifyZeros identify_zeros = kDistinguishZeros,
+    const FeedbackSource& feedback = FeedbackSource()) {
   switch (hint) {
     case NumberOperationHint::kSignedSmall:
     case NumberOperationHint::kSignedSmallInputs:
       return UseInfo::CheckedSignedSmallAsWord32(identify_zeros, feedback);
     case NumberOperationHint::kNumber:
+      DCHECK_EQ(identify_zeros, kIdentifyZeros);
       return UseInfo::CheckedNumberAsWord32(feedback);
     case NumberOperationHint::kNumberOrBoolean:
       // Not used currently.
       UNREACHABLE();
     case NumberOperationHint::kNumberOrOddball:
+      DCHECK_EQ(identify_zeros, kIdentifyZeros);
       return UseInfo::CheckedNumberOrOddballAsWord32(feedback);
   }
   UNREACHABLE();
@@ -142,6 +144,7 @@ UseInfo TruncatingUseInfoFromRepresentation(MachineRepresentation rep) {
       return UseInfo::TaggedSigned();
     case MachineRepresentation::kTaggedPointer:
     case MachineRepresentation::kTagged:
+    case MachineRepresentation::kMapWord:
       return UseInfo::AnyTagged();
     case MachineRepresentation::kFloat64:
       return UseInfo::TruncatingFloat64();
@@ -215,7 +218,7 @@ bool CanOverflowSigned32(const Operator* op, Type left, Type right,
 }
 
 bool IsSomePositiveOrderedNumber(Type type) {
-  return type.Is(Type::OrderedNumber()) && !type.IsNone() && type.Min() > 0;
+  return type.Is(Type::OrderedNumber()) && (type.IsNone() || type.Min() > 0);
 }
 
 }  // namespace
@@ -291,15 +294,17 @@ class RepresentationSelector {
     Type restriction_type() const { return restriction_type_; }
 
    private:
+    // Fields are ordered to avoid mixing byte and word size fields to minimize
+    // padding.
     enum State : uint8_t { kUnvisited, kPushed, kVisited, kQueued };
     State state_ = kUnvisited;
     MachineRepresentation representation_ =
         MachineRepresentation::kNone;             // Output representation.
     Truncation truncation_ = Truncation::None();  // Information about uses.
+    bool weakened_ = false;
 
     Type restriction_type_ = Type::Any();
     Type feedback_type_;
-    bool weakened_ = false;
   };
 
   RepresentationSelector(JSGraph* jsgraph, JSHeapBroker* broker, Zone* zone,
@@ -717,7 +722,7 @@ class RepresentationSelector {
   void EnqueueInput(Node* use_node, int index,
                     UseInfo use_info = UseInfo::None()) {
     static_assert(retype<T>() || lower<T>(),
-                  "This version of ProcessRemainingInputs has to be called in "
+                  "This version of EnqueueInput has to be called in "
                   "the Retype or Lower phase.");
   }
 
@@ -784,9 +789,9 @@ class RepresentationSelector {
     // TODO(jarin,turbofan) Find a way to unify/merge this insertion with
     // InsertUnreachableIfNecessary.
     Node* unreachable = effect =
-        graph()->NewNode(jsgraph_->common()->Unreachable(), effect, control);
+        graph()->NewNode(common()->Unreachable(), effect, control);
     const Operator* dead_value =
-        jsgraph_->common()->DeadValue(GetInfo(node)->representation());
+        common()->DeadValue(GetInfo(node)->representation());
     node->ReplaceInput(0, unreachable);
     node->TrimInputCount(dead_value->ValueInputCount());
     ReplaceEffectControlUses(node, effect, control);
@@ -833,7 +838,13 @@ class RepresentationSelector {
     } else {
       DCHECK_EQ(0, node->op()->ControlInputCount());
     }
-    node->InsertInput(jsgraph_->zone(), new_input_index, new_input);
+    if (new_input_index == 0) {
+      node->InsertInput(jsgraph_->zone(), 0, new_input);
+    } else {
+      DCHECK_EQ(new_input_index, 1);
+      DCHECK_EQ(node->InputCount(), 1);
+      node->AppendInput(jsgraph_->zone(), new_input);
+    }
     ChangeOp(node, new_op);
   }
 
@@ -924,7 +935,15 @@ class RepresentationSelector {
       ProcessInput<T>(node, i, UseInfo::None());
     }
     ProcessRemainingInputs<T>(node, first_effect_index);
-    if (lower<T>()) Kill(node);
+
+    if (lower<T>()) {
+      TRACE("disconnecting unused #%d:%s\n", node->id(),
+            node->op()->mnemonic());
+      DisconnectFromEffectAndControl(node);
+      node->NullAllInputs();
+      // We still keep the partial node connected to its uses, knowing that
+      // lowering these operators is going to eliminate the uses.
+    }
   }
 
   // Helper for no-op node.
@@ -966,7 +985,8 @@ class RepresentationSelector {
                            MachineRepresentation::kWord32);
     }
     NumberOperationHint hint = NumberOperationHintOf(node->op());
-    return VisitBinop<T>(node, CheckedUseInfoAsWord32FromHint(hint),
+    return VisitBinop<T>(node,
+                         CheckedUseInfoAsWord32FromHint(hint, kIdentifyZeros),
                          MachineRepresentation::kWord32);
   }
 
@@ -1233,7 +1253,7 @@ class RepresentationSelector {
             DeoptMachineTypeOf(GetInfo(input)->representation(), TypeOf(input));
       }
       SparseInputMask mask = SparseInputMaskOf(node->op());
-      ChangeOp(node, jsgraph_->common()->TypedStateValues(types, mask));
+      ChangeOp(node, common()->TypedStateValues(types, mask));
     }
     SetOutput<T>(node, MachineRepresentation::kTagged);
   }
@@ -1282,9 +1302,9 @@ class RepresentationSelector {
 
         node->ReplaceInput(
             FrameState::kFrameStateStackInput,
-            jsgraph_->graph()->NewNode(jsgraph_->common()->TypedStateValues(
-                                           types, SparseInputMask::Dense()),
-                                       node.stack()));
+            jsgraph_->graph()->NewNode(
+                common()->TypedStateValues(types, SparseInputMask::Dense()),
+                node.stack()));
       }
     }
 
@@ -1323,8 +1343,7 @@ class RepresentationSelector {
           ConvertInput(node, i, UseInfo::AnyTagged());
         }
       }
-      ChangeOp(node, jsgraph_->common()->TypedObjectState(
-                         ObjectIdOf(node->op()), types));
+      ChangeOp(node, common()->TypedObjectState(ObjectIdOf(node->op()), types));
     }
     SetOutput<T>(node, MachineRepresentation::kTagged);
   }
@@ -1484,8 +1503,8 @@ class RepresentationSelector {
     }
 
     // Try to use type feedback.
-    NumberOperationHint hint = NumberOperationHintOf(node->op());
-    DCHECK_EQ(hint, NumberOperationHint::kSignedSmall);
+    NumberOperationHint const hint = NumberOperationHint::kSignedSmall;
+    DCHECK_EQ(hint, NumberOperationHintOf(node->op()));
 
     Type left_feedback_type = TypeOf(node->InputAt(0));
     Type right_feedback_type = TypeOf(node->InputAt(1));
@@ -1525,14 +1544,13 @@ class RepresentationSelector {
           !right_feedback_type.Maybe(Type::MinusZero())) {
         left_identify_zeros = kIdentifyZeros;
       }
-      UseInfo left_use = CheckedUseInfoAsWord32FromHint(hint, FeedbackSource(),
-                                                        left_identify_zeros);
+      UseInfo left_use =
+          CheckedUseInfoAsWord32FromHint(hint, left_identify_zeros);
       // For CheckedInt32Add and CheckedInt32Sub, we don't need to do
       // a minus zero check for the right hand side, since we already
       // know that the left hand side is a proper Signed32 value,
       // potentially guarded by a check.
-      UseInfo right_use = CheckedUseInfoAsWord32FromHint(hint, FeedbackSource(),
-                                                         kIdentifyZeros);
+      UseInfo right_use = CheckedUseInfoAsWord32FromHint(hint, kIdentifyZeros);
       VisitBinop<T>(node, left_use, right_use, MachineRepresentation::kWord32,
                     restriction);
     }
@@ -1543,7 +1561,6 @@ class RepresentationSelector {
                                right_feedback_type, type_cache_,
                                graph_zone())) {
         ChangeToPureOp(node, Int32Op(node));
-
       } else {
         ChangeToInt32OverflowOp(node);
       }
@@ -1627,10 +1644,10 @@ class RepresentationSelector {
       // mode of the {truncation}; and for modulus the sign of the
       // right hand side doesn't matter anyways, so in particular there's
       // no observable difference between a 0 and a -0 then.
-      UseInfo const lhs_use = CheckedUseInfoAsWord32FromHint(
-          hint, FeedbackSource(), truncation.identify_zeros());
-      UseInfo const rhs_use = CheckedUseInfoAsWord32FromHint(
-          hint, FeedbackSource(), kIdentifyZeros);
+      UseInfo const lhs_use =
+          CheckedUseInfoAsWord32FromHint(hint, truncation.identify_zeros());
+      UseInfo const rhs_use =
+          CheckedUseInfoAsWord32FromHint(hint, kIdentifyZeros);
       if (truncation.IsUsedAsWord32()) {
         VisitBinop<T>(node, lhs_use, rhs_use, MachineRepresentation::kWord32);
         if (lower<T>()) DeferReplacement(node, lowering->Int32Mod(node));
@@ -1788,6 +1805,7 @@ class RepresentationSelector {
       case CTypeInfo::Type::kFloat64:
         return UseInfo::CheckedNumberAsFloat64(kDistinguishZeros, feedback);
       case CTypeInfo::Type::kV8Value:
+      case CTypeInfo::Type::kApiObject:
         return UseInfo::AnyTagged();
     }
   }
@@ -1944,6 +1962,33 @@ class RepresentationSelector {
                  SimplifiedLowering* lowering) {
     tick_counter_->TickAndMaybeEnterSafepoint();
 
+    if (lower<T>()) {
+      // Kill non-effectful operations that have a None-type input and are thus
+      // dead code. Otherwise we might end up lowering the operation in a way,
+      // e.g. by replacing it with a constant, that cuts the dependency on a
+      // deopting operation (the producer of the None type), possibly resulting
+      // in a nonsense schedule.
+      if (node->op()->EffectOutputCount() == 0 &&
+          node->op()->ControlOutputCount() == 0 &&
+          node->opcode() != IrOpcode::kDeadValue &&
+          node->opcode() != IrOpcode::kStateValues &&
+          node->opcode() != IrOpcode::kFrameState &&
+          node->opcode() != IrOpcode::kPhi) {
+        for (int i = 0; i < node->op()->ValueInputCount(); i++) {
+          Node* input = node->InputAt(i);
+          if (TypeOf(input).IsNone()) {
+            node->ReplaceInput(0, input);
+            node->TrimInputCount(1);
+            ChangeOp(node,
+                     common()->DeadValue(GetInfo(node)->representation()));
+            return;
+          }
+        }
+      } else {
+        InsertUnreachableIfNecessary<T>(node);
+      }
+    }
+
     // Unconditionally eliminate unused pure nodes (only relevant if there's
     // a pure operation in between two effectful ones, where the last one
     // is unused).
@@ -1957,8 +2002,6 @@ class RepresentationSelector {
       return VisitUnused<T>(node);
     }
 
-    if (lower<T>()) InsertUnreachableIfNecessary<T>(node);
-
     switch (node->opcode()) {
       //------------------------------------------------------------------
       // Common operators.
@@ -2182,10 +2225,9 @@ class RepresentationSelector {
         switch (hint) {
           case NumberOperationHint::kSignedSmall:
             if (propagate<T>()) {
-              VisitBinop<T>(node,
-                            CheckedUseInfoAsWord32FromHint(
-                                hint, FeedbackSource(), kIdentifyZeros),
-                            MachineRepresentation::kBit);
+              VisitBinop<T>(
+                  node, CheckedUseInfoAsWord32FromHint(hint, kIdentifyZeros),
+                  MachineRepresentation::kBit);
             } else if (retype<T>()) {
               SetOutput<T>(node, MachineRepresentation::kBit, Type::Any());
             } else {
@@ -2202,10 +2244,9 @@ class RepresentationSelector {
                     node, changer_->TaggedSignedOperatorFor(node->opcode()));
 
               } else {
-                VisitBinop<T>(node,
-                              CheckedUseInfoAsWord32FromHint(
-                                  hint, FeedbackSource(), kIdentifyZeros),
-                              MachineRepresentation::kBit);
+                VisitBinop<T>(
+                    node, CheckedUseInfoAsWord32FromHint(hint, kIdentifyZeros),
+                    MachineRepresentation::kBit);
                 ChangeToPureOp(node, Int32Op(node));
               }
             }
@@ -2497,7 +2538,8 @@ class RepresentationSelector {
         }
         NumberOperationHint hint = NumberOperationHintOf(node->op());
         Type rhs_type = GetUpperBound(node->InputAt(1));
-        VisitBinop<T>(node, CheckedUseInfoAsWord32FromHint(hint),
+        VisitBinop<T>(node,
+                      CheckedUseInfoAsWord32FromHint(hint, kIdentifyZeros),
                       MachineRepresentation::kWord32, Type::Signed32());
         if (lower<T>()) {
           MaskShiftOperand(node, rhs_type);
@@ -2530,7 +2572,8 @@ class RepresentationSelector {
         }
         NumberOperationHint hint = NumberOperationHintOf(node->op());
         Type rhs_type = GetUpperBound(node->InputAt(1));
-        VisitBinop<T>(node, CheckedUseInfoAsWord32FromHint(hint),
+        VisitBinop<T>(node,
+                      CheckedUseInfoAsWord32FromHint(hint, kIdentifyZeros),
                       MachineRepresentation::kWord32, Type::Signed32());
         if (lower<T>()) {
           MaskShiftOperand(node, rhs_type);
@@ -2559,7 +2602,8 @@ class RepresentationSelector {
           // have seen so far were of type Unsigned31.  We speculate that this
           // will continue to hold.  Moreover, since the RHS is 0, the result
           // will just be the (converted) LHS.
-          VisitBinop<T>(node, CheckedUseInfoAsWord32FromHint(hint),
+          VisitBinop<T>(node,
+                        CheckedUseInfoAsWord32FromHint(hint, kIdentifyZeros),
                         MachineRepresentation::kWord32, Type::Unsigned31());
           if (lower<T>()) {
             node->RemoveInput(1);
@@ -2578,7 +2622,8 @@ class RepresentationSelector {
           }
           return;
         }
-        VisitBinop<T>(node, CheckedUseInfoAsWord32FromHint(hint),
+        VisitBinop<T>(node,
+                      CheckedUseInfoAsWord32FromHint(hint, kIdentifyZeros),
                       MachineRepresentation::kWord32, Type::Unsigned32());
         if (lower<T>()) {
           MaskShiftOperand(node, rhs_type);
@@ -2785,9 +2830,25 @@ class RepresentationSelector {
         }
         return;
       }
-      case IrOpcode::kBigIntAsUintN: {
-        ProcessInput<T>(node, 0, UseInfo::TruncatingWord64());
+      case IrOpcode::kSpeculativeBigIntAsUintN: {
+        const auto p = SpeculativeBigIntAsUintNParametersOf(node->op());
+        DCHECK_LE(0, p.bits());
+        DCHECK_LE(p.bits(), 64);
+
+        ProcessInput<T>(node, 0,
+                        UseInfo::CheckedBigIntTruncatingWord64(p.feedback()));
         SetOutput<T>(node, MachineRepresentation::kWord64, Type::BigInt());
+        if (lower<T>()) {
+          if (p.bits() == 0) {
+            DeferReplacement(node, jsgraph_->ZeroConstant());
+          } else if (p.bits() == 64) {
+            DeferReplacement(node, node->InputAt(0));
+          } else {
+            const uint64_t mask = (1ULL << p.bits()) - 1ULL;
+            ChangeUnaryToPureBinaryOp(node, lowering->machine()->Word64And(), 1,
+                                      jsgraph_->Int64Constant(mask));
+          }
+        }
         return;
       }
       case IrOpcode::kNumberAcos:
@@ -3437,7 +3498,8 @@ class RepresentationSelector {
           case NumberOperationHint::kSignedSmall:
           case NumberOperationHint::kSignedSmallInputs:
             VisitUnop<T>(node,
-                         CheckedUseInfoAsWord32FromHint(p.hint(), p.feedback()),
+                         CheckedUseInfoAsWord32FromHint(
+                             p.hint(), kDistinguishZeros, p.feedback()),
                          MachineRepresentation::kWord32, Type::Signed32());
             break;
           case NumberOperationHint::kNumber:
@@ -3876,6 +3938,21 @@ class RepresentationSelector {
       case IrOpcode::kAssertType:
         return VisitUnop<T>(node, UseInfo::AnyTagged(),
                             MachineRepresentation::kTagged);
+      case IrOpcode::kVerifyType: {
+        Type inputType = TypeOf(node->InputAt(0));
+        VisitUnop<T>(node, UseInfo::AnyTagged(), MachineRepresentation::kTagged,
+                     inputType);
+        if (lower<T>()) {
+          CHECK_IMPLIES(!FLAG_fuzzing, inputType.CanBeAsserted());
+          if (inputType.CanBeAsserted()) {
+            ChangeOp(node, simplified()->AssertType(inputType));
+          } else {
+            DeferReplacement(node, node->InputAt(0));
+          }
+        }
+        return;
+      }
+
       default:
         FATAL(
             "Representation inference: unsupported opcode %i (%s), node #%i\n.",
@@ -3885,34 +3962,8 @@ class RepresentationSelector {
     UNREACHABLE();
   }
 
-  void DeferReplacement(Node* node, Node* replacement) {
-    TRACE("defer replacement #%d:%s with #%d:%s\n", node->id(),
-          node->op()->mnemonic(), replacement->id(),
-          replacement->op()->mnemonic());
-
-    // Disconnect the node from effect and control chains, if necessary.
-    if (node->op()->EffectInputCount() > 0) {
-      DCHECK_LT(0, node->op()->ControlInputCount());
-      // Disconnect the node from effect and control chains.
-      Node* control = NodeProperties::GetControlInput(node);
-      Node* effect = NodeProperties::GetEffectInput(node);
-      ReplaceEffectControlUses(node, effect, control);
-    }
-
-    replacements_.push_back(node);
-    replacements_.push_back(replacement);
-
-    node->NullAllInputs();  // Node is now dead.
-
-    NotifyNodeReplaced(node, replacement);
-  }
-
-  void Kill(Node* node) {
-    TRACE("killing #%d:%s\n", node->id(), node->op()->mnemonic());
-
+  void DisconnectFromEffectAndControl(Node* node) {
     if (node->op()->EffectInputCount() == 1) {
-      DCHECK_LT(0, node->op()->ControlInputCount());
-      // Disconnect the node from effect and control chains.
       Node* control = NodeProperties::GetControlInput(node);
       Node* effect = NodeProperties::GetEffectInput(node);
       ReplaceEffectControlUses(node, effect, control);
@@ -3921,10 +3972,20 @@ class RepresentationSelector {
       DCHECK_EQ(0, node->op()->ControlOutputCount());
       DCHECK_EQ(0, node->op()->EffectOutputCount());
     }
+  }
+
+  void DeferReplacement(Node* node, Node* replacement) {
+    TRACE("defer replacement #%d:%s with #%d:%s\n", node->id(),
+          node->op()->mnemonic(), replacement->id(),
+          replacement->op()->mnemonic());
 
-    node->ReplaceUses(jsgraph_->Dead());
+    DisconnectFromEffectAndControl(node);
+    node->NullAllInputs();  // Node is now dead.
 
-    node->NullAllInputs();  // The {node} is now dead.
+    replacements_.push_back(node);
+    replacements_.push_back(replacement);
+
+    NotifyNodeReplaced(node, replacement);
   }
 
  private:
diff --git a/chromium/v8/src/compiler/simplified-operator-reducer.cc b/chromium/v8/src/compiler/simplified-operator-reducer.cc
index b1d3f8b2f3a..6bc984008db 100644
--- a/chromium/v8/src/compiler/simplified-operator-reducer.cc
+++ b/chromium/v8/src/compiler/simplified-operator-reducer.cc
@@ -5,6 +5,7 @@
 #include "src/compiler/simplified-operator-reducer.h"
 
 #include "src/compiler/js-graph.h"
+#include "src/compiler/js-heap-broker.h"
 #include "src/compiler/machine-operator.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/operator-properties.h"
@@ -41,7 +42,7 @@ SimplifiedOperatorReducer::~SimplifiedOperatorReducer() = default;
 
 
 Reduction SimplifiedOperatorReducer::Reduce(Node* node) {
-  DisallowHeapAccessIf no_heap_access(!FLAG_turbo_direct_heap_access);
+  DisallowHeapAccessIf no_heap_access(!broker()->is_concurrent_inlining());
   switch (node->opcode()) {
     case IrOpcode::kBooleanNot: {
       HeapObjectMatcher m(node->InputAt(0));
@@ -60,7 +61,9 @@ Reduction SimplifiedOperatorReducer::Reduce(Node* node) {
     case IrOpcode::kChangeTaggedToBit: {
       HeapObjectMatcher m(node->InputAt(0));
       if (m.HasResolvedValue()) {
-        return ReplaceInt32(m.Ref(broker()).BooleanValue());
+        base::Optional<bool> maybe_result =
+            m.Ref(broker()).TryGetBooleanValue();
+        if (maybe_result.has_value()) return ReplaceInt32(*maybe_result);
       }
       if (m.IsChangeBitToTagged()) return Replace(m.InputAt(0));
       break;
diff --git a/chromium/v8/src/compiler/simplified-operator.cc b/chromium/v8/src/compiler/simplified-operator.cc
index 09e3a80ec48..32cc9eea950 100644
--- a/chromium/v8/src/compiler/simplified-operator.cc
+++ b/chromium/v8/src/compiler/simplified-operator.cc
@@ -615,6 +615,27 @@ NumberOperationParameters const& NumberOperationParametersOf(
   return OpParameter<NumberOperationParameters>(op);
 }
 
+bool operator==(SpeculativeBigIntAsUintNParameters const& lhs,
+                SpeculativeBigIntAsUintNParameters const& rhs) {
+  return lhs.bits() == rhs.bits() && lhs.feedback() == rhs.feedback();
+}
+
+size_t hash_value(SpeculativeBigIntAsUintNParameters const& p) {
+  FeedbackSource::Hash feedback_hash;
+  return base::hash_combine(p.bits(), feedback_hash(p.feedback()));
+}
+
+std::ostream& operator<<(std::ostream& os,
+                         SpeculativeBigIntAsUintNParameters const& p) {
+  return os << p.bits() << ", " << p.feedback();
+}
+
+SpeculativeBigIntAsUintNParameters const& SpeculativeBigIntAsUintNParametersOf(
+    Operator const* op) {
+  DCHECK_EQ(IrOpcode::kSpeculativeBigIntAsUintN, op->opcode());
+  return OpParameter<SpeculativeBigIntAsUintNParameters>(op);
+}
+
 size_t hash_value(AllocateParameters info) {
   return base::hash_combine(info.type(),
                             static_cast<int>(info.allocation_type()));
@@ -1296,11 +1317,14 @@ const Operator* SimplifiedOperatorBuilder::RuntimeAbort(AbortReason reason) {
       static_cast<int>(reason));                // parameter
 }
 
-const Operator* SimplifiedOperatorBuilder::BigIntAsUintN(int bits) {
+const Operator* SimplifiedOperatorBuilder::SpeculativeBigIntAsUintN(
+    int bits, const FeedbackSource& feedback) {
   CHECK(0 <= bits && bits <= 64);
 
-  return zone()->New<Operator1<int>>(IrOpcode::kBigIntAsUintN, Operator::kPure,
-                                     "BigIntAsUintN", 1, 0, 0, 1, 0, 0, bits);
+  return zone()->New<Operator1<SpeculativeBigIntAsUintNParameters>>(
+      IrOpcode::kSpeculativeBigIntAsUintN, Operator::kNoProperties,
+      "SpeculativeBigIntAsUintN", 1, 1, 1, 1, 1, 0,
+      SpeculativeBigIntAsUintNParameters(bits, feedback));
 }
 
 const Operator* SimplifiedOperatorBuilder::UpdateInterruptBudget(int delta) {
@@ -1316,12 +1340,18 @@ const Operator* SimplifiedOperatorBuilder::TierUpCheck() {
 }
 
 const Operator* SimplifiedOperatorBuilder::AssertType(Type type) {
-  DCHECK(type.IsRange());
+  DCHECK(type.CanBeAsserted());
   return zone()->New<Operator1<Type>>(IrOpcode::kAssertType,
                                       Operator::kNoThrow | Operator::kNoDeopt,
                                       "AssertType", 1, 0, 0, 1, 0, 0, type);
 }
 
+const Operator* SimplifiedOperatorBuilder::VerifyType() {
+  return zone()->New<Operator>(IrOpcode::kVerifyType,
+                               Operator::kNoThrow | Operator::kNoDeopt,
+                               "VerifyType", 1, 0, 0, 1, 0, 0);
+}
+
 const Operator* SimplifiedOperatorBuilder::CheckIf(
     DeoptimizeReason reason, const FeedbackSource& feedback) {
   if (!feedback.IsValid()) {
diff --git a/chromium/v8/src/compiler/simplified-operator.h b/chromium/v8/src/compiler/simplified-operator.h
index cd66b89ea44..03ca88bc9af 100644
--- a/chromium/v8/src/compiler/simplified-operator.h
+++ b/chromium/v8/src/compiler/simplified-operator.h
@@ -127,6 +127,13 @@ struct FieldAccess {
 #endif
   {
     DCHECK_GE(offset, 0);
+    DCHECK_IMPLIES(
+        machine_type.IsMapWord(),
+        offset == HeapObject::kMapOffset && base_is_tagged != kUntaggedBase);
+    DCHECK_IMPLIES(machine_type.IsMapWord(),
+                   (write_barrier_kind == kMapWriteBarrier ||
+                    write_barrier_kind == kNoWriteBarrier ||
+                    write_barrier_kind == kAssertNoWriteBarrier));
   }
 
   int tag() const { return base_is_tagged == kTaggedBase ? kHeapObjectTag : 0; }
@@ -599,6 +606,30 @@ bool operator==(NumberOperationParameters const&,
 const NumberOperationParameters& NumberOperationParametersOf(const Operator* op)
     V8_WARN_UNUSED_RESULT;
 
+class SpeculativeBigIntAsUintNParameters {
+ public:
+  SpeculativeBigIntAsUintNParameters(int bits, const FeedbackSource& feedback)
+      : bits_(bits), feedback_(feedback) {
+    DCHECK_GE(bits_, 0);
+    DCHECK_LE(bits_, 64);
+  }
+
+  int bits() const { return bits_; }
+  const FeedbackSource& feedback() const { return feedback_; }
+
+ private:
+  int bits_;
+  FeedbackSource feedback_;
+};
+
+size_t hash_value(SpeculativeBigIntAsUintNParameters const&);
+V8_EXPORT_PRIVATE std::ostream& operator<<(
+    std::ostream&, const SpeculativeBigIntAsUintNParameters&);
+bool operator==(SpeculativeBigIntAsUintNParameters const&,
+                SpeculativeBigIntAsUintNParameters const&);
+const SpeculativeBigIntAsUintNParameters& SpeculativeBigIntAsUintNParametersOf(
+    const Operator* op) V8_WARN_UNUSED_RESULT;
+
 int FormalParameterCountOf(const Operator* op) V8_WARN_UNUSED_RESULT;
 
 class AllocateParameters {
@@ -806,7 +837,8 @@ class V8_EXPORT_PRIVATE SimplifiedOperatorBuilder final
   const Operator* SpeculativeBigIntAdd(BigIntOperationHint hint);
   const Operator* SpeculativeBigIntSubtract(BigIntOperationHint hint);
   const Operator* SpeculativeBigIntNegate(BigIntOperationHint hint);
-  const Operator* BigIntAsUintN(int bits);
+  const Operator* SpeculativeBigIntAsUintN(int bits,
+                                           const FeedbackSource& feedback);
 
   const Operator* ReferenceEqual();
   const Operator* SameValue();
@@ -1054,6 +1086,10 @@ class V8_EXPORT_PRIVATE SimplifiedOperatorBuilder final
   // Abort if the value input does not inhabit the given type
   const Operator* AssertType(Type type);
 
+  // Abort if the value does not match the node's computed type after
+  // SimplifiedLowering.
+  const Operator* VerifyType();
+
   const Operator* DateNow();
 
   // Represents the inputs necessary to construct a fast and a slow API call.
@@ -1112,7 +1148,7 @@ class FastApiCallNode final : public SimplifiedNodeWrapperBase {
  public:
   explicit constexpr FastApiCallNode(Node* node)
       : SimplifiedNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kFastApiCall);
+    DCHECK_EQ(IrOpcode::kFastApiCall, node->opcode());
   }
 
   const FastApiCallParameters& Parameters() const {
@@ -1184,7 +1220,7 @@ class TierUpCheckNode final : public SimplifiedNodeWrapperBase {
  public:
   explicit constexpr TierUpCheckNode(Node* node)
       : SimplifiedNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kTierUpCheck);
+    DCHECK_EQ(IrOpcode::kTierUpCheck, node->opcode());
   }
 
 #define INPUTS(V)                                       \
@@ -1201,7 +1237,7 @@ class UpdateInterruptBudgetNode final : public SimplifiedNodeWrapperBase {
  public:
   explicit constexpr UpdateInterruptBudgetNode(Node* node)
       : SimplifiedNodeWrapperBase(node) {
-    CONSTEXPR_DCHECK(node->opcode() == IrOpcode::kUpdateInterruptBudget);
+    DCHECK_EQ(IrOpcode::kUpdateInterruptBudget, node->opcode());
   }
 
   int delta() const { return OpParameter<int>(node()->op()); }
diff --git a/chromium/v8/src/compiler/store-store-elimination.cc b/chromium/v8/src/compiler/store-store-elimination.cc
index 70dadd94417..3600ee1a41a 100644
--- a/chromium/v8/src/compiler/store-store-elimination.cc
+++ b/chromium/v8/src/compiler/store-store-elimination.cc
@@ -331,8 +331,8 @@ UnobservablesSet RedundantStoreFinder::RecomputeSet(
 bool RedundantStoreFinder::CannotObserveStoreField(Node* node) {
   IrOpcode::Value opcode = node->opcode();
   return opcode == IrOpcode::kLoadElement || opcode == IrOpcode::kLoad ||
-         opcode == IrOpcode::kStore || opcode == IrOpcode::kEffectPhi ||
-         opcode == IrOpcode::kStoreElement ||
+         opcode == IrOpcode::kLoadImmutable || opcode == IrOpcode::kStore ||
+         opcode == IrOpcode::kEffectPhi || opcode == IrOpcode::kStoreElement ||
          opcode == IrOpcode::kUnsafePointerAdd || opcode == IrOpcode::kRetain;
 }
 
diff --git a/chromium/v8/src/compiler/type-cache.h b/chromium/v8/src/compiler/type-cache.h
index 2ade5f68a3b..6442b6f6b0e 100644
--- a/chromium/v8/src/compiler/type-cache.h
+++ b/chromium/v8/src/compiler/type-cache.h
@@ -36,9 +36,10 @@ class V8_EXPORT_PRIVATE TypeCache final {
   Type const kUnsigned31 = Type::Unsigned31();
   Type const kInt32 = Type::Signed32();
   Type const kUint32 = Type::Unsigned32();
-  Type const kInt64 = CreateRange<int64_t>();
-  Type const kUint64 = CreateRange<uint64_t>();
-  Type const kIntPtr = CreateRange<intptr_t>();
+  Type const kDoubleRepresentableInt64 = CreateRange(
+      std::numeric_limits<int64_t>::min(), kMaxDoubleRepresentableInt64);
+  Type const kDoubleRepresentableUint64 = CreateRange(
+      std::numeric_limits<uint64_t>::min(), kMaxDoubleRepresentableUint64);
   Type const kFloat32 = Type::Number();
   Type const kFloat64 = Type::Number();
   Type const kBigInt64 = Type::BigInt();
@@ -190,8 +191,11 @@ class V8_EXPORT_PRIVATE TypeCache final {
  private:
   template <typename T>
   Type CreateRange() {
-    return CreateRange(std::numeric_limits<T>::min(),
-                       std::numeric_limits<T>::max());
+    T min = std::numeric_limits<T>::min();
+    T max = std::numeric_limits<T>::max();
+    DCHECK_EQ(min, static_cast<T>(static_cast<double>(min)));
+    DCHECK_EQ(max, static_cast<T>(static_cast<double>(max)));
+    return CreateRange(min, max);
   }
 
   Type CreateRange(double min, double max) {
@@ -199,6 +203,10 @@ class V8_EXPORT_PRIVATE TypeCache final {
   }
 
   Zone* zone() { return &zone_; }
+
+  static constexpr double kMaxDoubleRepresentableInt64 = 9223372036854774784.0;
+  static constexpr double kMaxDoubleRepresentableUint64 =
+      18446744073709549568.0;
 };
 
 }  // namespace compiler
diff --git a/chromium/v8/src/compiler/type-narrowing-reducer.cc b/chromium/v8/src/compiler/type-narrowing-reducer.cc
index b24e82c53b8..996b0883762 100644
--- a/chromium/v8/src/compiler/type-narrowing-reducer.cc
+++ b/chromium/v8/src/compiler/type-narrowing-reducer.cc
@@ -5,6 +5,7 @@
 #include "src/compiler/type-narrowing-reducer.h"
 
 #include "src/compiler/js-graph.h"
+#include "src/compiler/js-heap-broker.h"
 
 namespace v8 {
 namespace internal {
@@ -12,12 +13,15 @@ namespace compiler {
 
 TypeNarrowingReducer::TypeNarrowingReducer(Editor* editor, JSGraph* jsgraph,
                                            JSHeapBroker* broker)
-    : AdvancedReducer(editor), jsgraph_(jsgraph), op_typer_(broker, zone()) {}
+    : AdvancedReducer(editor),
+      jsgraph_(jsgraph),
+      broker_(broker),
+      op_typer_(broker, zone()) {}
 
 TypeNarrowingReducer::~TypeNarrowingReducer() = default;
 
 Reduction TypeNarrowingReducer::Reduce(Node* node) {
-  DisallowHeapAccessIf no_heap_access(!FLAG_turbo_direct_heap_access);
+  DisallowHeapAccessIf no_heap_access(!broker_->is_concurrent_inlining());
 
   Type new_type = Type::Any();
 
diff --git a/chromium/v8/src/compiler/type-narrowing-reducer.h b/chromium/v8/src/compiler/type-narrowing-reducer.h
index ab8c4a483c3..9ec6883449d 100644
--- a/chromium/v8/src/compiler/type-narrowing-reducer.h
+++ b/chromium/v8/src/compiler/type-narrowing-reducer.h
@@ -34,6 +34,7 @@ class V8_EXPORT_PRIVATE TypeNarrowingReducer final
   Zone* zone() const;
 
   JSGraph* const jsgraph_;
+  const JSHeapBroker* const broker_;
   OperationTyper op_typer_;
 };
 
diff --git a/chromium/v8/src/compiler/typed-optimization.cc b/chromium/v8/src/compiler/typed-optimization.cc
index d5bc845f7c5..3c16c7317c5 100644
--- a/chromium/v8/src/compiler/typed-optimization.cc
+++ b/chromium/v8/src/compiler/typed-optimization.cc
@@ -34,7 +34,7 @@ TypedOptimization::TypedOptimization(Editor* editor,
 TypedOptimization::~TypedOptimization() = default;
 
 Reduction TypedOptimization::Reduce(Node* node) {
-  DisallowHeapAccessIf no_heap_access(!FLAG_turbo_direct_heap_access);
+  DisallowHeapAccessIf no_heap_access(!broker()->is_concurrent_inlining());
   switch (node->opcode()) {
     case IrOpcode::kConvertReceiver:
       return ReduceConvertReceiver(node);
diff --git a/chromium/v8/src/compiler/typer.cc b/chromium/v8/src/compiler/typer.cc
index 0f182222364..09daaa3864c 100644
--- a/chromium/v8/src/compiler/typer.cc
+++ b/chromium/v8/src/compiler/typer.cc
@@ -1839,8 +1839,6 @@ Type Typer::Visitor::TypeJSCallRuntime(Node* node) {
       return TypeUnaryOp(node, ToNumber);
     case Runtime::kInlineToObject:
       return TypeUnaryOp(node, ToObject);
-    case Runtime::kInlineToString:
-      return TypeUnaryOp(node, ToString);
     case Runtime::kHasInPrototypeChain:
       return Type::Boolean();
     default:
@@ -2361,6 +2359,10 @@ Type Typer::Visitor::TypeRuntimeAbort(Node* node) { UNREACHABLE(); }
 
 Type Typer::Visitor::TypeAssertType(Node* node) { UNREACHABLE(); }
 
+Type Typer::Visitor::TypeVerifyType(Node* node) {
+  return TypeOrNone(node->InputAt(0));
+}
+
 // Heap constants.
 
 Type Typer::Visitor::TypeConstant(Handle<Object> value) {
diff --git a/chromium/v8/src/compiler/types.cc b/chromium/v8/src/compiler/types.cc
index 236cff3cc68..5c6a4f7db94 100644
--- a/chromium/v8/src/compiler/types.cc
+++ b/chromium/v8/src/compiler/types.cc
@@ -6,6 +6,7 @@
 
 #include <iomanip>
 
+#include "src/compiler/js-heap-broker.h"
 #include "src/handles/handles-inl.h"
 #include "src/objects/instance-type.h"
 #include "src/objects/objects-inl.h"
@@ -837,7 +838,14 @@ Type Type::Constant(double value, Zone* zone) {
 }
 
 Type Type::Constant(JSHeapBroker* broker, Handle<i::Object> value, Zone* zone) {
-  ObjectRef ref(broker, value);
+  // TODO(jgruber,chromium:1209798): Using kAssumeMemoryFence works around
+  // the fact that the graph stores handles (and not refs). The assumption is
+  // that any handle inserted into the graph is safe to read; but we don't
+  // preserve the reason why it is safe to read. Thus we must over-approximate
+  // here and assume the existence of a memory fence. In the future, we should
+  // consider having the graph store ObjectRefs or ObjectData pointer instead,
+  // which would make new ref construction here unnecessary.
+  ObjectRef ref = MakeRefAssumeMemoryFence(broker, value);
   if (ref.IsSmi()) {
     return Constant(static_cast<double>(ref.AsSmi()), zone);
   }
@@ -969,8 +977,7 @@ const char* BitsetType::Name(bitset bits) {
   }
 }
 
-void BitsetType::Print(std::ostream& os,  // NOLINT
-                       bitset bits) {
+void BitsetType::Print(std::ostream& os, bitset bits) {
   DisallowGarbageCollection no_gc;
   const char* name = Name(bits);
   if (name != nullptr) {
diff --git a/chromium/v8/src/compiler/types.h b/chromium/v8/src/compiler/types.h
index b5692298ab0..a28a28c59e9 100644
--- a/chromium/v8/src/compiler/types.h
+++ b/chromium/v8/src/compiler/types.h
@@ -267,7 +267,7 @@ class V8_EXPORT_PRIVATE BitsetType {
   static bitset ExpandInternals(bitset bits);
 
   static const char* Name(bitset);
-  static void Print(std::ostream& os, bitset);  // NOLINT
+  static void Print(std::ostream& os, bitset);
 #ifdef DEBUG
   static void Print(bitset);
 #endif
@@ -413,6 +413,10 @@ class V8_EXPORT_PRIVATE Type {
            (Is(Type::PlainNumber()) && Min() == Max());
   }
 
+  bool CanBeAsserted() const {
+    return IsRange() || (Is(Type::Integral32()) && !IsNone());
+  }
+
   const HeapConstantType* AsHeapConstant() const;
   const OtherNumberConstantType* AsOtherNumberConstant() const;
   const RangeType* AsRange() const;
diff --git a/chromium/v8/src/compiler/verifier.cc b/chromium/v8/src/compiler/verifier.cc
index b5b3ab5a981..8b7e22459b9 100644
--- a/chromium/v8/src/compiler/verifier.cc
+++ b/chromium/v8/src/compiler/verifier.cc
@@ -482,8 +482,8 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       Node* control = NodeProperties::GetControlInput(node, 0);
       CHECK_EQ(effect_count, control->op()->ControlInputCount());
       CHECK_EQ(input_count, 1 + effect_count);
-      // If the control input is a Merge, then make sure that at least one
-      // of it's usages is non-phi.
+      // If the control input is a Merge, then make sure that at least one of
+      // its usages is non-phi.
       if (control->opcode() == IrOpcode::kMerge) {
         bool non_phi_use_found = false;
         for (Node* use : control->uses()) {
@@ -954,8 +954,8 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
     case IrOpcode::kSpeculativeBigIntNegate:
       CheckTypeIs(node, Type::BigInt());
       break;
-    case IrOpcode::kBigIntAsUintN:
-      CheckValueInputIs(node, 0, Type::BigInt());
+    case IrOpcode::kSpeculativeBigIntAsUintN:
+      CheckValueInputIs(node, 0, Type::Any());
       CheckTypeIs(node, Type::BigInt());
       break;
     case IrOpcode::kBigIntAdd:
@@ -1500,6 +1500,15 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
     case IrOpcode::kAssertType:
       break;
 
+    case IrOpcode::kVerifyType:
+      if (NodeProperties::IsTyped(node)) {
+        Node* input = NodeProperties::GetValueInput(node, 0);
+        DCHECK(NodeProperties::IsTyped(input));
+        CHECK(NodeProperties::GetType(node).Equals(
+            NodeProperties::GetType(input)));
+      }
+      break;
+
     case IrOpcode::kCheckFloat64Hole:
       CheckValueInputIs(node, 0, Type::NumberOrHole());
       CheckTypeIs(node, Type::NumberOrUndefined());
@@ -1658,8 +1667,12 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
     case IrOpcode::kWord64Rol:
     case IrOpcode::kWord64Ror:
     case IrOpcode::kWord64Clz:
-    case IrOpcode::kWord64Popcnt:
     case IrOpcode::kWord64Ctz:
+    case IrOpcode::kWord64RolLowerable:
+    case IrOpcode::kWord64RorLowerable:
+    case IrOpcode::kWord64ClzLowerable:
+    case IrOpcode::kWord64CtzLowerable:
+    case IrOpcode::kWord64Popcnt:
     case IrOpcode::kWord64ReverseBits:
     case IrOpcode::kWord64ReverseBytes:
     case IrOpcode::kSimd128ReverseBytes:
@@ -1791,6 +1804,8 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
     case IrOpcode::kFloat64ExtractHighWord32:
     case IrOpcode::kFloat64InsertLowWord32:
     case IrOpcode::kFloat64InsertHighWord32:
+    case IrOpcode::kWord32Select:
+    case IrOpcode::kWord64Select:
     case IrOpcode::kFloat32Select:
     case IrOpcode::kFloat64Select:
     case IrOpcode::kInt32PairAdd:
@@ -1850,7 +1865,7 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       // TODO(rossberg): Check.
       break;
   }
-}  // NOLINT(readability/fn_size)
+}
 
 void Verifier::Run(Graph* graph, Typing typing, CheckInputs check_inputs,
                    CodeType code_type) {
diff --git a/chromium/v8/src/compiler/wasm-compiler.cc b/chromium/v8/src/compiler/wasm-compiler.cc
index 1b858f5dfcb..6e433def702 100644
--- a/chromium/v8/src/compiler/wasm-compiler.cc
+++ b/chromium/v8/src/compiler/wasm-compiler.cc
@@ -16,7 +16,7 @@
 #include "src/codegen/assembler.h"
 #include "src/codegen/code-factory.h"
 #include "src/codegen/compiler.h"
-#include "src/codegen/interface-descriptors.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/machine-type.h"
 #include "src/codegen/optimized-compilation-info.h"
 #include "src/compiler/backend/code-generator.h"
@@ -34,7 +34,6 @@
 #include "src/compiler/node-origin-table.h"
 #include "src/compiler/node-properties.h"
 #include "src/compiler/pipeline.h"
-#include "src/compiler/simd-scalar-lowering.h"
 #include "src/compiler/zone-stats.h"
 #include "src/execution/isolate-inl.h"
 #include "src/heap/factory.h"
@@ -131,11 +130,7 @@ constexpr Builtins::Name WasmRuntimeStubIdToBuiltinName(
 #undef DEF_CASE
 #undef DEF_TRAP_CASE
     default:
-#if V8_HAS_CXX14_CONSTEXPR
       UNREACHABLE();
-#else
-      return Builtins::kAbort;
-#endif
   }
 }
 
@@ -291,10 +286,6 @@ class WasmGraphAssembler : public GraphAssembler {
 
   // Maps and their contents.
 
-  Node* LoadMap(Node* heap_object) {
-    return LoadFromObject(MachineType::TaggedPointer(), heap_object,
-                          wasm::ObjectAccess::ToTagged(HeapObject::kMapOffset));
-  }
   Node* LoadInstanceType(Node* map) {
     return LoadFromObject(
         MachineType::Uint16(), map,
@@ -710,8 +701,23 @@ void WasmGraphBuilder::PatchInStackCheckIfNeeded() {
   if (effect() == dummy) return;
 
   // Now patch all control uses of {start} to use {control} and all effect uses
-  // to use {effect} instead. Then rewire the dummy node to use start instead.
+  // to use {effect} instead. We exclude Projection nodes: Projections pointing
+  // to start are floating control, and we want it to point directly to start
+  // because of restrictions later in the pipeline (specifically, loop
+  // unrolling).
+  // Then rewire the dummy node to use start instead.
   NodeProperties::ReplaceUses(start, start, effect(), control());
+  {
+    // We need an intermediate vector because we are not allowed to modify a use
+    // while traversing uses().
+    std::vector<Node*> projections;
+    for (Node* use : control()->uses()) {
+      if (use->opcode() == IrOpcode::kProjection) projections.emplace_back(use);
+    }
+    for (Node* use : projections) {
+      use->ReplaceInput(NodeProperties::FirstControlIndex(use), start);
+    }
+  }
   NodeProperties::ReplaceUses(dummy, nullptr, start, start);
 }
 
@@ -874,17 +880,19 @@ Node* WasmGraphBuilder::Binop(wasm::WasmOpcode opcode, Node* left, Node* right,
       std::swap(left, right);
       break;
     case wasm::kExprI64Ror:
-      op = m->Word64Ror();
       right = MaskShiftCount64(right);
-      break;
+      return m->Is64() ? graph()->NewNode(m->Word64Ror(), left, right)
+                       : graph()->NewNode(m->Word64RorLowerable(), left, right,
+                                          control());
     case wasm::kExprI64Rol:
       if (m->Word64Rol().IsSupported()) {
-        op = m->Word64Rol().op();
-        right = MaskShiftCount64(right);
-        break;
+        return m->Is64() ? graph()->NewNode(m->Word64Rol().op(), left,
+                                            MaskShiftCount64(right))
+                         : graph()->NewNode(m->Word64RolLowerable().op(), left,
+                                            MaskShiftCount64(right), control());
       } else if (m->Word32Rol().IsSupported()) {
-        op = m->Word64Rol().placeholder();
-        break;
+        return graph()->NewNode(m->Word64RolLowerable().placeholder(), left,
+                                right, control());
       }
       return BuildI64Rol(left, right);
     case wasm::kExprF32CopySign:
@@ -1175,19 +1183,22 @@ Node* WasmGraphBuilder::Unop(wasm::WasmOpcode opcode, Node* input,
       op = m->BitcastFloat64ToInt64();
       break;
     case wasm::kExprI64Clz:
-      op = m->Word64Clz();
-      break;
+      return m->Is64()
+                 ? graph()->NewNode(m->Word64Clz(), input)
+                 : graph()->NewNode(m->Word64ClzLowerable(), input, control());
     case wasm::kExprI64Ctz: {
-      OptionalOperator ctz64 = m->Word64Ctz();
-      if (ctz64.IsSupported()) {
-        op = ctz64.op();
-        break;
+      if (m->Word64Ctz().IsSupported()) {
+        return m->Is64() ? graph()->NewNode(m->Word64Ctz().op(), input)
+                         : graph()->NewNode(m->Word64CtzLowerable().op(), input,
+                                            control());
       } else if (m->Is32() && m->Word32Ctz().IsSupported()) {
-        op = ctz64.placeholder();
-        break;
+        return graph()->NewNode(m->Word64CtzLowerable().placeholder(), input,
+                                control());
       } else if (m->Word64ReverseBits().IsSupported()) {
         Node* reversed = graph()->NewNode(m->Word64ReverseBits().op(), input);
-        Node* result = graph()->NewNode(m->Word64Clz(), reversed);
+        Node* result = m->Is64() ? graph()->NewNode(m->Word64Clz(), reversed)
+                                 : graph()->NewNode(m->Word64ClzLowerable(),
+                                                    reversed, control());
         return result;
       } else {
         return BuildI64Ctz(input);
@@ -1301,6 +1312,11 @@ Node* WasmGraphBuilder::BranchExpectFalse(Node* cond, Node** true_node,
   return gasm_->Branch(cond, true_node, false_node, BranchHint::kFalse);
 }
 
+Node* WasmGraphBuilder::BranchExpectTrue(Node* cond, Node** true_node,
+                                         Node** false_node) {
+  return gasm_->Branch(cond, true_node, false_node, BranchHint::kTrue);
+}
+
 Node* WasmGraphBuilder::Select(Node *cond, Node* true_node,
                                Node* false_node, wasm::ValueType type) {
   MachineOperatorBuilder* m = mcgraph()->machine();
@@ -1314,6 +1330,14 @@ Node* WasmGraphBuilder::Select(Node *cond, Node* true_node,
     return mcgraph()->graph()->NewNode(m->Float64Select().op(), cond,
                                        true_node, false_node);
   }
+  if (kind == wasm::kI32 && m->Word32Select().IsSupported()) {
+    return mcgraph()->graph()->NewNode(m->Word32Select().op(), cond, true_node,
+                                       false_node);
+  }
+  if (kind == wasm::kI64 && m->Word64Select().IsSupported()) {
+    return mcgraph()->graph()->NewNode(m->Word64Select().op(), cond, true_node,
+                                       false_node);
+  }
   // Default to control-flow.
   Node* controls[2];
   BranchNoHint(cond, &controls[0], &controls[1]);
@@ -2944,7 +2968,7 @@ Node* WasmGraphBuilder::BuildImportCall(const wasm::FunctionSig* sig,
   Node* imported_function_refs =
       LOAD_INSTANCE_FIELD(ImportedFunctionRefs, MachineType::TaggedPointer());
   // Access fixed array at {header_size - tag + func_index * kTaggedSize}.
-  Node* func_index_intptr = Uint32ToUintptr(func_index);
+  Node* func_index_intptr = BuildChangeUint32ToUintPtr(func_index);
   Node* ref_node = gasm_->LoadFixedArrayElement(
       imported_function_refs, func_index_intptr, MachineType::TaggedPointer());
 
@@ -3070,36 +3094,28 @@ Node* WasmGraphBuilder::BuildIndirectCall(uint32_t table_index,
 
   const wasm::ValueType table_type = env_->module->tables[table_index].type;
   // Check that the table entry is not null and that the type of the function is
-  // a subtype of the function type declared at the call site. In the absence of
-  // function subtyping, the latter can only happen if the table type is (ref
-  // null? func). Also, subtyping reduces to normalized signature equality
-  // checking.
-  // TODO(7748): Expand this with function subtyping once we have that.
+  // **identical with** the function type declared at the call site (no
+  // subtyping of functions is allowed).
+  // Note: Since null entries are identified by having ift_sig_id (-1), we only
+  // need one comparison.
+  // TODO(9495): Change this if we should do full function subtyping instead.
   const bool needs_signature_check =
+      FLAG_experimental_wasm_gc ||
       table_type.is_reference_to(wasm::HeapType::kFunc) ||
       table_type.is_nullable();
   if (needs_signature_check) {
     Node* int32_scaled_key =
-        Uint32ToUintptr(gasm_->Word32Shl(key, Int32Constant(2)));
+        BuildChangeUint32ToUintPtr(gasm_->Word32Shl(key, Int32Constant(2)));
 
     Node* loaded_sig = gasm_->LoadFromObject(MachineType::Int32(), ift_sig_ids,
                                              int32_scaled_key);
-
-    if (table_type.is_reference_to(wasm::HeapType::kFunc)) {
-      int32_t expected_sig_id = env_->module->canonicalized_type_ids[sig_index];
-      Node* sig_match =
-          gasm_->Word32Equal(loaded_sig, Int32Constant(expected_sig_id));
-      TrapIfFalse(wasm::kTrapFuncSigMismatch, sig_match, position);
-    } else {
-      // If the table entries are nullable, we still have to check that the
-      // entry is initialized.
-      Node* function_is_null =
-          gasm_->Word32Equal(loaded_sig, Int32Constant(-1));
-      TrapIfTrue(wasm::kTrapNullDereference, function_is_null, position);
-    }
+    int32_t expected_sig_id = env_->module->canonicalized_type_ids[sig_index];
+    Node* sig_match =
+        gasm_->Word32Equal(loaded_sig, Int32Constant(expected_sig_id));
+    TrapIfFalse(wasm::kTrapFuncSigMismatch, sig_match, position);
   }
 
-  Node* key_intptr = Uint32ToUintptr(key);
+  Node* key_intptr = BuildChangeUint32ToUintPtr(key);
 
   Node* target_instance = gasm_->LoadFixedArrayElement(
       ift_instances, key_intptr, MachineType::TaggedPointer());
@@ -3124,13 +3140,28 @@ Node* WasmGraphBuilder::BuildIndirectCall(uint32_t table_index,
   }
 }
 
-Node* WasmGraphBuilder::BuildLoadJumpTableOffsetFromExportedFunctionData(
+Node* WasmGraphBuilder::BuildLoadCallTargetFromExportedFunctionData(
     Node* function_data) {
-  Node* jump_table_offset_smi = gasm_->LoadFromObject(
-      MachineType::TaggedSigned(), function_data,
-      wasm::ObjectAccess::ToTagged(
-          WasmExportedFunctionData::kJumpTableOffsetOffset));
-  return BuildChangeSmiToIntPtr(jump_table_offset_smi);
+  // TODO(saelo) move this code into a common LoadExternalPointer routine?
+#ifdef V8_HEAP_SANDBOX
+  Node* index = gasm_->LoadFromObject(
+      MachineType::Pointer(), function_data,
+      wasm::ObjectAccess::ToTagged(WasmFunctionData::kForeignAddressOffset));
+
+  Node* isolate_root = BuildLoadIsolateRoot();
+  Node* table =
+      gasm_->LoadFromObject(MachineType::Pointer(), isolate_root,
+                            IsolateData::external_pointer_table_offset() +
+                                Internals::kExternalPointerTableBufferOffset);
+  Node* offset = gasm_->Int32Mul(index, gasm_->Int32Constant(8));
+  Node* decoded_ptr = gasm_->Load(MachineType::Pointer(), table, offset);
+  Node* tag = gasm_->IntPtrConstant(~kForeignForeignAddressTag);
+  return gasm_->WordAnd(decoded_ptr, tag);
+#else
+  return gasm_->LoadFromObject(
+      MachineType::Pointer(), function_data,
+      wasm::ObjectAccess::ToTagged(WasmFunctionData::kForeignAddressOffset));
+#endif
 }
 
 // TODO(9495): Support CAPI function refs.
@@ -3148,77 +3179,33 @@ Node* WasmGraphBuilder::BuildCallRef(uint32_t sig_index, Vector<Node*> args,
 
   Node* function_data = gasm_->LoadFunctionDataFromJSFunction(args[0]);
 
-  Node* is_js_function =
-      gasm_->HasInstanceType(function_data, WASM_JS_FUNCTION_DATA_TYPE);
-
-  auto js_label = gasm_->MakeLabel();
-  auto end_label = gasm_->MakeLabel(MachineRepresentation::kTaggedPointer,
-                                    MachineRepresentation::kTaggedPointer);
+  auto load_target = gasm_->MakeLabel();
+  auto end_label = gasm_->MakeLabel(MachineType::PointerRepresentation());
 
-  gasm_->GotoIf(is_js_function, &js_label);
+  Node* instance_node = gasm_->LoadFromObject(
+      MachineType::TaggedPointer(), function_data,
+      wasm::ObjectAccess::ToTagged(WasmFunctionData::kRefOffset));
 
+  Node* is_pair = gasm_->HasInstanceType(instance_node, TUPLE2_TYPE);
+  gasm_->GotoIfNot(is_pair, &load_target);
   {
-    // Call to a WasmExportedFunction.
-    // Load instance object corresponding to module where callee is defined.
-    Node* callee_instance = gasm_->LoadExportedFunctionInstance(function_data);
-    Node* function_index = gasm_->LoadExportedFunctionIndexAsSmi(function_data);
-
-    auto imported_label = gasm_->MakeLabel();
-
-    // Check if callee is a locally defined or imported function in its module.
-    Node* imported_function_refs = gasm_->LoadFromObject(
-        MachineType::TaggedPointer(), callee_instance,
-        wasm::ObjectAccess::ToTagged(
-            WasmInstanceObject::kImportedFunctionRefsOffset));
-    Node* imported_functions_num =
-        gasm_->LoadFixedArrayLengthAsSmi(imported_function_refs);
-    gasm_->GotoIf(gasm_->SmiLessThan(function_index, imported_functions_num),
-                  &imported_label);
-    {
-      // Function locally defined in module.
-      Node* jump_table_start =
-          gasm_->LoadFromObject(MachineType::Pointer(), callee_instance,
-                                wasm::ObjectAccess::ToTagged(
-                                    WasmInstanceObject::kJumpTableStartOffset));
-      Node* jump_table_offset =
-          BuildLoadJumpTableOffsetFromExportedFunctionData(function_data);
-      Node* jump_table_slot =
-          gasm_->IntAdd(jump_table_start, jump_table_offset);
-
-      gasm_->Goto(&end_label, jump_table_slot,
-                  callee_instance /* Unused, dummy value */);
-    }
-
-    {
-      // Function imported to module.
-      gasm_->Bind(&imported_label);
-      Node* function_index_intptr = BuildChangeSmiToIntPtr(function_index);
-
-      Node* imported_instance = gasm_->LoadFixedArrayElement(
-          imported_function_refs, function_index_intptr,
-          MachineType::TaggedPointer());
-
-      Node* imported_function_targets = gasm_->LoadFromObject(
-          MachineType::Pointer(), callee_instance,
-          wasm::ObjectAccess::ToTagged(
-              WasmInstanceObject::kImportedFunctionTargetsOffset));
-
-      Node* target_node = gasm_->LoadFromObject(
-          MachineType::Pointer(), imported_function_targets,
-          gasm_->IntMul(function_index_intptr,
-                        gasm_->IntPtrConstant(kSystemPointerSize)));
-
-      gasm_->Goto(&end_label, target_node, imported_instance);
-    }
-  }
-
+    // Overwrite the tuple's "instance" entry with the current instance.
+    // TODO(jkummerow): Can we avoid this, by guaranteeing that it's always
+    // pre-populated?
+    gasm_->StoreToObject(
+        ObjectAccess(MachineType::TaggedPointer(), kFullWriteBarrier),
+        instance_node, wasm::ObjectAccess::ToTagged(Tuple2::kValue1Offset),
+        GetInstance());
+    gasm_->Goto(&load_target);
+  }
+
+  gasm_->Bind(&load_target);
+  Node* target = BuildLoadCallTargetFromExportedFunctionData(function_data);
+  Node* is_null_target = gasm_->WordEqual(target, gasm_->IntPtrConstant(0));
+  gasm_->GotoIfNot(is_null_target, &end_label, target);
   {
-    // Call to a WasmJSFunction. The call target is
-    // function_data->wasm_to_js_wrapper_code()->instruction_start().
-    // The instance_node is the pair
-    // (current WasmInstanceObject, function_data->callable()).
-    gasm_->Bind(&js_label);
-
+    // Compute the call target from the (on-heap) wrapper code. The cached
+    // target can only be null for WasmJSFunctions.
     Node* wrapper_code = gasm_->LoadFromObject(
         MachineType::TaggedPointer(), function_data,
         wasm::ObjectAccess::ToTagged(
@@ -3226,23 +3213,12 @@ Node* WasmGraphBuilder::BuildCallRef(uint32_t sig_index, Vector<Node*> args,
     Node* call_target = gasm_->IntAdd(
         wrapper_code,
         gasm_->IntPtrConstant(wasm::ObjectAccess::ToTagged(Code::kHeaderSize)));
-
-    Node* callable = gasm_->LoadFromObject(
-        MachineType::TaggedPointer(), function_data,
-        wasm::ObjectAccess::ToTagged(WasmJSFunctionData::kCallableOffset));
-    // TODO(manoskouk): Find an elegant way to avoid allocating this pair for
-    // every call.
-    Node* function_instance_node =
-        gasm_->CallBuiltin(Builtins::kWasmAllocatePair, Operator::kEliminatable,
-                           GetInstance(), callable);
-
-    gasm_->Goto(&end_label, call_target, function_instance_node);
+    gasm_->Goto(&end_label, call_target);
   }
 
   gasm_->Bind(&end_label);
 
   args[0] = end_label.PhiAt(0);
-  Node* instance_node = end_label.PhiAt(1);
 
   const UseRetpoline use_retpoline =
       untrusted_code_mitigations_ ? kRetpoline : kNoRetpoline;
@@ -3345,6 +3321,25 @@ Node* WasmGraphBuilder::BuildChangeIntPtrToInt64(Node* value) {
                                       : value;
 }
 
+Node* WasmGraphBuilder::BuildChangeUint32ToUintPtr(Node* node) {
+  if (mcgraph()->machine()->Is32()) return node;
+  // Fold instances of ChangeUint32ToUint64(IntConstant) directly.
+  Uint32Matcher matcher(node);
+  if (matcher.HasResolvedValue()) {
+    uintptr_t value = matcher.ResolvedValue();
+    return mcgraph()->IntPtrConstant(bit_cast<intptr_t>(value));
+  }
+  return gasm_->ChangeUint32ToUint64(node);
+}
+
+Node* WasmGraphBuilder::BuildSmiShiftBitsConstant() {
+  return gasm_->IntPtrConstant(kSmiShiftSize + kSmiTagSize);
+}
+
+Node* WasmGraphBuilder::BuildSmiShiftBitsConstant32() {
+  return Int32Constant(kSmiShiftSize + kSmiTagSize);
+}
+
 Node* WasmGraphBuilder::BuildChangeInt32ToSmi(Node* value) {
   // With pointer compression, only the lower 32 bits are used.
   return COMPRESS_POINTERS_BOOL
@@ -3356,31 +3351,22 @@ Node* WasmGraphBuilder::BuildChangeInt32ToSmi(Node* value) {
 Node* WasmGraphBuilder::BuildChangeUint31ToSmi(Node* value) {
   return COMPRESS_POINTERS_BOOL
              ? gasm_->Word32Shl(value, BuildSmiShiftBitsConstant32())
-             : gasm_->WordShl(Uint32ToUintptr(value),
+             : gasm_->WordShl(BuildChangeUint32ToUintPtr(value),
                               BuildSmiShiftBitsConstant());
 }
 
-Node* WasmGraphBuilder::BuildSmiShiftBitsConstant() {
-  return gasm_->IntPtrConstant(kSmiShiftSize + kSmiTagSize);
-}
-
-Node* WasmGraphBuilder::BuildSmiShiftBitsConstant32() {
-  return Int32Constant(kSmiShiftSize + kSmiTagSize);
-}
-
 Node* WasmGraphBuilder::BuildChangeSmiToInt32(Node* value) {
   return COMPRESS_POINTERS_BOOL
-             ? gasm_->Word32Sar(gasm_->TruncateInt64ToInt32(value),
-                                BuildSmiShiftBitsConstant32())
-             : BuildTruncateIntPtrToInt32(BuildChangeSmiToIntPtr(value));
+             ? gasm_->Word32Sar(value, BuildSmiShiftBitsConstant32())
+             : BuildTruncateIntPtrToInt32(
+                   gasm_->WordSar(value, BuildSmiShiftBitsConstant()));
 }
 
 Node* WasmGraphBuilder::BuildChangeSmiToIntPtr(Node* value) {
-  if (COMPRESS_POINTERS_BOOL) {
-    value = BuildChangeSmiToInt32(value);
-    return BuildChangeInt32ToIntPtr(value);
-  }
-  return gasm_->WordSar(value, BuildSmiShiftBitsConstant());
+  return COMPRESS_POINTERS_BOOL
+             ? BuildChangeInt32ToIntPtr(
+                   gasm_->Word32Sar(value, BuildSmiShiftBitsConstant32()))
+             : gasm_->WordSar(value, BuildSmiShiftBitsConstant());
 }
 
 Node* WasmGraphBuilder::BuildConvertUint32ToSmiWithSaturation(Node* value,
@@ -3565,8 +3551,8 @@ void WasmGraphBuilder::GetBaseAndOffsetForImportedMutableExternRefGlobal(
   // From the index, calculate the actual offset in the FixedArray. This
   // is kHeaderSize + (index * kTaggedSize). kHeaderSize can be acquired with
   // wasm::ObjectAccess::ElementOffsetInTaggedFixedArray(0).
-  Node* index_times_tagged_size =
-      gasm_->IntMul(Uint32ToUintptr(index), Int32Constant(kTaggedSize));
+  Node* index_times_tagged_size = gasm_->IntMul(
+      BuildChangeUint32ToUintPtr(index), Int32Constant(kTaggedSize));
   *offset = gasm_->IntAdd(
       index_times_tagged_size,
       mcgraph()->IntPtrConstant(
@@ -3763,7 +3749,7 @@ Node* WasmGraphBuilder::BoundsCheckMem(uint8_t access_size, Node* index,
                                        wasm::WasmCodePosition position,
                                        EnforceBoundsCheck enforce_check) {
   DCHECK_LE(1, access_size);
-  if (!env_->module->is_memory64) index = Uint32ToUintptr(index);
+  if (!env_->module->is_memory64) index = BuildChangeUint32ToUintPtr(index);
   if (!FLAG_wasm_bounds_checks) return index;
 
   if (use_trap_handler() && enforce_check == kCanOmitBoundsCheck) {
@@ -4317,7 +4303,7 @@ Node* WasmGraphBuilder::BuildAsmjsLoadMem(MachineType type, Node* index) {
   // Note that we check against the memory size ignoring the size of the
   // stored value, which is conservative if misaligned. Technically, asm.js
   // should never have misaligned accesses.
-  index = Uint32ToUintptr(index);
+  index = BuildChangeUint32ToUintPtr(index);
   Diamond bounds_check(graph(), mcgraph()->common(),
                        gasm_->UintLessThan(index, mem_size), BranchHint::kTrue);
   bounds_check.Chain(control());
@@ -4356,17 +4342,6 @@ Node* WasmGraphBuilder::BuildAsmjsLoadMem(MachineType type, Node* index) {
   return bounds_check.Phi(type.representation(), load, oob_value);
 }
 
-Node* WasmGraphBuilder::Uint32ToUintptr(Node* node) {
-  if (mcgraph()->machine()->Is32()) return node;
-  // Fold instances of ChangeUint32ToUint64(IntConstant) directly.
-  Uint32Matcher matcher(node);
-  if (matcher.HasResolvedValue()) {
-    uintptr_t value = matcher.ResolvedValue();
-    return mcgraph()->IntPtrConstant(bit_cast<intptr_t>(value));
-  }
-  return gasm_->ChangeUint32ToUint64(node);
-}
-
 Node* WasmGraphBuilder::BuildAsmjsStoreMem(MachineType type, Node* index,
                                            Node* val) {
   DCHECK_NOT_NULL(instance_cache_);
@@ -4391,7 +4366,7 @@ Node* WasmGraphBuilder::BuildAsmjsStoreMem(MachineType type, Node* index,
     index = gasm_->Word32And(index, mem_mask);
   }
 
-  index = Uint32ToUintptr(index);
+  index = BuildChangeUint32ToUintPtr(index);
   const Operator* store_op = mcgraph()->machine()->Store(StoreRepresentation(
       type.representation(), WriteBarrierKind::kNoWriteBarrier));
   Node* store = graph()->NewNode(store_op, mem_start, index, val, effect(),
@@ -5335,12 +5310,7 @@ Node* WasmGraphBuilder::AtomicOp(wasm::WasmOpcode opcode, Node* const* inputs,
         case wasm::kExprI64AtomicWait:
           return {kSpecial, MachineType::Int64(), OperatorByType{nullptr}};
         default:
-#if V8_HAS_CXX14_CONSTEXPR
           UNREACHABLE();
-#else
-          // Return something for older GCC.
-          return {kSpecial, MachineType::Int64(), OperatorByType{nullptr}};
-#endif
       }
     }
   };
@@ -5572,6 +5542,16 @@ Node* WasmGraphBuilder::StructNewWithRtt(uint32_t struct_index,
   for (uint32_t i = 0; i < type->field_count(); i++) {
     gasm_->StoreStructField(s, type, i, fields[i]);
   }
+  if (type->field_count() == 0) {
+    static_assert(Heap::kMinObjectSizeInTaggedWords == 2 &&
+                      WasmStruct::kHeaderSize == kTaggedSize,
+                  "empty structs need exactly one padding field");
+    wasm::ValueType fake_type = wasm::kWasmAnyRef;
+    Node* padding_offset = gasm_->IntPtrConstant(
+        wasm::ObjectAccess::ToTagged(WasmStruct::kHeaderSize));
+    gasm_->StoreToObject(ObjectAccessForGCStores(fake_type), s, padding_offset,
+                         RefNull());
+  }
   return s;
 }
 
@@ -6560,7 +6540,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
   Node* BuildCallAllocateJSArray(Node* array_length, Node* context) {
     // Since we don't check that args will fit in an array,
     // we make sure this is true based on statically known limits.
-    STATIC_ASSERT(wasm::kV8MaxWasmFunctionMultiReturns <=
+    STATIC_ASSERT(wasm::kV8MaxWasmFunctionReturns <=
                   JSArray::kInitialMaxFastElementArray);
     return gasm_->CallBuiltin(Builtins::kWasmAllocateJSArray,
                               Operator::kEliminatable, array_length, context);
@@ -6588,15 +6568,8 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
                         wasm::kNoCodePosition, function_index, kCallContinues);
       } else {
         // Call to a wasm function defined in this module.
-        // The call target is the jump table slot for that function.
-        Node* jump_table_start =
-            LOAD_INSTANCE_FIELD(JumpTableStart, MachineType::Pointer());
-        Node* jump_table_offset =
-            BuildLoadJumpTableOffsetFromExportedFunctionData(function_data);
-        Node* jump_table_slot =
-            gasm_->IntAdd(jump_table_start, jump_table_offset);
-        args[0] = jump_table_slot;
-
+        // The (cached) call target is the jump table slot for that function.
+        args[0] = BuildLoadCallTargetFromExportedFunctionData(function_data);
         BuildWasmCall(sig_, VectorOf(args), VectorOf(rets),
                       wasm::kNoCodePosition, nullptr, kNoRetpoline,
                       frame_state);
@@ -6670,9 +6643,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
       case wasm::kF64: {
         auto done = gasm_->MakeLabel();
         gasm_->GotoIf(IsSmi(input), &done);
-        Node* map = gasm_->LoadFromObject(
-            MachineType::TaggedPointer(), input,
-            wasm::ObjectAccess::ToTagged(HeapObject::kMapOffset));
+        Node* map = gasm_->LoadMap(input);
         Node* heap_number_map = LOAD_ROOT(HeapNumberMap, heap_number_map);
         Node* is_heap_number = gasm_->WordEqual(heap_number_map, map);
         gasm_->GotoIf(is_heap_number, &done);
@@ -7030,6 +7001,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
 
     BuildModifyThreadInWasmFlag(true);
 
+    Node* old_effect = effect();
     Node* exception_branch = graph()->NewNode(
         mcgraph()->common()->Branch(BranchHint::kTrue),
         gasm_->WordEqual(return_value, mcgraph()->IntPtrConstant(0)),
@@ -7046,10 +7018,9 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
     gasm_->Call(call_descriptor, call_target, return_value);
     TerminateThrow(effect(), control());
 
-    SetEffectControl(
-        return_value,
-        graph()->NewNode(mcgraph()->common()->IfTrue(), exception_branch));
-    DCHECK_LT(sig_->return_count(), wasm::kV8MaxWasmFunctionMultiReturns);
+    SetEffectControl(old_effect, graph()->NewNode(mcgraph()->common()->IfTrue(),
+                                                  exception_branch));
+    DCHECK_LT(sig_->return_count(), wasm::kV8MaxWasmFunctionReturns);
     size_t return_count = sig_->return_count();
     if (return_count == 0) {
       Return(Int32Constant(0));
@@ -7090,9 +7061,12 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
 
     // Load the original callable from the closure.
     Node* func_data = gasm_->LoadFunctionDataFromJSFunction(closure);
-    Node* callable = gasm_->LoadFromObject(
+    Node* pair = gasm_->LoadFromObject(
         MachineType::AnyTagged(), func_data,
-        wasm::ObjectAccess::ToTagged(WasmJSFunctionData::kCallableOffset));
+        wasm::ObjectAccess::ToTagged(WasmJSFunctionData::kRefOffset));
+    Node* callable = gasm_->LoadFromObject(
+        MachineType::AnyTagged(), pair,
+        wasm::ObjectAccess::ToTagged(Tuple2::kValue2Offset));
 
     // Call the underlying closure.
     base::SmallVector<Node*, 16> args(wasm_count + 7);
@@ -7478,7 +7452,7 @@ wasm::WasmCompilationResult CompileWasmMathIntrinsic(
   wasm::CompilationEnv env(
       nullptr, wasm::UseTrapHandler::kNoTrapHandler,
       wasm::RuntimeExceptionSupport::kNoRuntimeExceptionSupport,
-      wasm::WasmFeatures::All(), wasm::LowerSimd::kNoLowerSimd);
+      wasm::WasmFeatures::All());
 
   WasmGraphBuilder builder(&env, mcgraph->zone(), mcgraph, sig,
                            source_positions);
@@ -7644,7 +7618,7 @@ MaybeHandle<Code> CompileWasmToJSWrapper(Isolate* isolate,
   MachineGraph* mcgraph = zone->New<MachineGraph>(graph, common, machine);
 
   WasmWrapperGraphBuilder builder(zone.get(), mcgraph, sig, nullptr, nullptr,
-                                  nullptr, StubCallMode::kCallWasmRuntimeStub,
+                                  nullptr, StubCallMode::kCallBuiltinPointer,
                                   wasm::WasmFeatures::FromIsolate(isolate));
   builder.BuildWasmToJSWrapper(kind, expected_arity);
 
@@ -7792,7 +7766,7 @@ bool BuildGraphForWasmFunction(AccountingAllocator* allocator,
                            source_positions);
   wasm::VoidResult graph_construction_result = wasm::BuildTFGraph(
       allocator, env->enabled_features, env->module, &builder, detected,
-      func_body, loop_infos, node_origins);
+      func_body, loop_infos, node_origins, func_index);
   if (graph_construction_result.failed()) {
     if (FLAG_trace_wasm_compiler) {
       StdoutStream{} << "Compilation failed: "
@@ -7802,49 +7776,8 @@ bool BuildGraphForWasmFunction(AccountingAllocator* allocator,
     return false;
   }
 
-  // Lower SIMD first, i64x2 nodes will be lowered to int64 nodes, then int64
-  // lowering will take care of them.
   auto sig = CreateMachineSignature(mcgraph->zone(), func_body.sig,
                                     WasmGraphBuilder::kCalledFromWasm);
-  if (builder.has_simd() &&
-      (!CpuFeatures::SupportsWasmSimd128() || env->lower_simd)) {
-    SimplifiedOperatorBuilder simplified(mcgraph->zone());
-    SimdScalarLowering(mcgraph, &simplified, sig).LowerGraph();
-
-    // SimdScalarLowering changes all v128 to 4 i32, so update the machine
-    // signature for the call to LowerInt64.
-    size_t return_count = 0;
-    size_t param_count = 0;
-    for (auto ret : sig->returns()) {
-      return_count += ret == MachineRepresentation::kSimd128 ? 4 : 1;
-    }
-    for (auto param : sig->parameters()) {
-      param_count += param == MachineRepresentation::kSimd128 ? 4 : 1;
-    }
-
-    Signature<MachineRepresentation>::Builder sig_builder(
-        mcgraph->zone(), return_count, param_count);
-    for (auto ret : sig->returns()) {
-      if (ret == MachineRepresentation::kSimd128) {
-        for (int i = 0; i < 4; ++i) {
-          sig_builder.AddReturn(MachineRepresentation::kWord32);
-        }
-      } else {
-        sig_builder.AddReturn(ret);
-      }
-    }
-    for (auto param : sig->parameters()) {
-      if (param == MachineRepresentation::kSimd128) {
-        for (int i = 0; i < 4; ++i) {
-          sig_builder.AddParam(MachineRepresentation::kWord32);
-        }
-      } else {
-        sig_builder.AddParam(param);
-      }
-    }
-    sig = sig_builder.Build();
-  }
-
   builder.LowerInt64(sig);
 
   if (func_index >= FLAG_trace_wasm_ast_start &&
@@ -7919,8 +7852,7 @@ wasm::WasmCompilationResult ExecuteTurbofanWasmCompilation(
     call_descriptor = GetI32WasmCallDescriptor(&zone, call_descriptor);
   }
 
-  if (ContainsSimd(func_body.sig) &&
-      (!CpuFeatures::SupportsWasmSimd128() || env->lower_simd)) {
+  if (ContainsSimd(func_body.sig) && !CpuFeatures::SupportsWasmSimd128()) {
     call_descriptor = GetI32WasmCallDescriptorForSimd(&zone, call_descriptor);
   }
 
diff --git a/chromium/v8/src/compiler/wasm-compiler.h b/chromium/v8/src/compiler/wasm-compiler.h
index a77e76a05d9..bb8f5f5efc0 100644
--- a/chromium/v8/src/compiler/wasm-compiler.h
+++ b/chromium/v8/src/compiler/wasm-compiler.h
@@ -281,6 +281,7 @@ class WasmGraphBuilder {
   //-----------------------------------------------------------------------
   Node* BranchNoHint(Node* cond, Node** true_node, Node** false_node);
   Node* BranchExpectFalse(Node* cond, Node** true_node, Node** false_node);
+  Node* BranchExpectTrue(Node* cond, Node** true_node, Node** false_node);
 
   void TrapIfTrue(wasm::TrapReason reason, Node* cond,
                   wasm::WasmCodePosition position);
@@ -530,7 +531,6 @@ class WasmGraphBuilder {
   Node* CheckBoundsAndAlignment(int8_t access_size, Node* index,
                                 uint64_t offset, wasm::WasmCodePosition);
 
-  Node* Uint32ToUintptr(Node*);
   const Operator* GetSafeLoadOperator(int offset, wasm::ValueType type);
   const Operator* GetSafeStoreOperator(int offset, wasm::ValueType type);
   Node* BuildChangeEndiannessStore(Node* node, MachineRepresentation rep,
@@ -631,6 +631,7 @@ class WasmGraphBuilder {
   Node* BuildTruncateIntPtrToInt32(Node* value);
   Node* BuildChangeInt32ToIntPtr(Node* value);
   Node* BuildChangeIntPtrToInt64(Node* value);
+  Node* BuildChangeUint32ToUintPtr(Node*);
   Node* BuildChangeInt32ToSmi(Node* value);
   Node* BuildChangeUint31ToSmi(Node* value);
   Node* BuildSmiShiftBitsConstant();
@@ -700,7 +701,7 @@ class WasmGraphBuilder {
   Node* BuildMultiReturnFixedArrayFromIterable(const wasm::FunctionSig* sig,
                                                Node* iterable, Node* context);
 
-  Node* BuildLoadJumpTableOffsetFromExportedFunctionData(Node* function_data);
+  Node* BuildLoadCallTargetFromExportedFunctionData(Node* function_data);
 
   //-----------------------------------------------------------------------
   // Operations involving the CEntry, a dependency we want to remove
diff --git a/chromium/v8/src/d8/async-hooks-wrapper.cc b/chromium/v8/src/d8/async-hooks-wrapper.cc
index 2538e78acbc..84191b98154 100644
--- a/chromium/v8/src/d8/async-hooks-wrapper.cc
+++ b/chromium/v8/src/d8/async-hooks-wrapper.cc
@@ -47,8 +47,7 @@ static AsyncHooksWrap* UnwrapHook(
   AsyncHooks* hooks = PerIsolateData::Get(isolate)->GetAsyncHooks();
 
   if (!hooks->async_hook_ctor.Get(isolate)->HasInstance(hook)) {
-    isolate->ThrowException(String::NewFromUtf8Literal(
-        isolate, "Invalid 'this' passed instead of AsyncHooks instance"));
+    isolate->ThrowError("Invalid 'this' passed instead of AsyncHooks instance");
     return nullptr;
   }
 
@@ -87,8 +86,7 @@ Local<Object> AsyncHooks::CreateHook(
   Local<Context> currentContext = isolate->GetCurrentContext();
 
   if (args.Length() != 1 || !args[0]->IsObject()) {
-    isolate->ThrowException(String::NewFromUtf8Literal(
-        isolate, "Invalid arguments passed to createHook"));
+    isolate->ThrowError("Invalid arguments passed to createHook");
     return Local<Object>();
   }
 
diff --git a/chromium/v8/src/d8/d8-console.cc b/chromium/v8/src/d8/d8-console.cc
index 7f0904e343f..fc76bab7ab2 100644
--- a/chromium/v8/src/d8/d8-console.cc
+++ b/chromium/v8/src/d8/d8-console.cc
@@ -19,7 +19,7 @@ void WriteToFile(const char* prefix, FILE* file, Isolate* isolate,
     Local<Value> arg = args[i];
     Local<String> str_obj;
 
-    if (arg->IsSymbol()) arg = Local<Symbol>::Cast(arg)->Description();
+    if (arg->IsSymbol()) arg = Local<Symbol>::Cast(arg)->Description(isolate);
     if (!arg->ToString(isolate->GetCurrentContext()).ToLocal(&str_obj)) return;
 
     v8::String::Utf8Value str(isolate, str_obj);
@@ -43,8 +43,7 @@ void D8Console::Assert(const debug::ConsoleCallArguments& args,
   // false-ish.
   if (args.Length() > 0 && args[0]->BooleanValue(isolate_)) return;
   WriteToFile("console.assert", stdout, isolate_, args);
-  isolate_->ThrowException(v8::Exception::Error(
-      v8::String::NewFromUtf8Literal(isolate_, "console.assert failed")));
+  isolate_->ThrowError("console.assert failed");
 }
 
 void D8Console::Log(const debug::ConsoleCallArguments& args,
diff --git a/chromium/v8/src/d8/d8-posix.cc b/chromium/v8/src/d8/d8-posix.cc
index 047b62ef2c4..fa30b9153d4 100644
--- a/chromium/v8/src/d8/d8-posix.cc
+++ b/chromium/v8/src/d8/d8-posix.cc
@@ -159,8 +159,8 @@ class ExecArgs {
   bool Init(Isolate* isolate, Local<Value> arg0, Local<Array> command_args) {
     String::Utf8Value prog(isolate, arg0);
     if (*prog == nullptr) {
-      isolate->ThrowException(String::NewFromUtf8Literal(
-          isolate, "os.system(): String conversion of program name failed"));
+      isolate->ThrowError(
+          "os.system(): String conversion of program name failed");
       return false;
     }
     int len = prog.length() + 3;
@@ -176,8 +176,8 @@ class ExecArgs {
       String::Utf8Value utf8_arg(isolate, arg);
       if (*utf8_arg == nullptr) {
         exec_args_[i] = nullptr;  // Consistent state for destructor.
-        isolate->ThrowException(String::NewFromUtf8Literal(
-            isolate, "os.system(): String conversion of argument failed."));
+        isolate->ThrowError(
+            "os.system(): String conversion of argument failed.");
         return false;
       }
       int len = utf8_arg.length() + 1;
@@ -214,8 +214,7 @@ static bool GetTimeouts(const v8::FunctionCallbackInfo<v8::Value>& args,
                            ->Int32Value(args.GetIsolate()->GetCurrentContext())
                            .FromJust();
     } else {
-      args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-          args.GetIsolate(), "system: Argument 4 must be a number"));
+      args.GetIsolate()->ThrowError("system: Argument 4 must be a number");
       return false;
     }
   }
@@ -225,14 +224,19 @@ static bool GetTimeouts(const v8::FunctionCallbackInfo<v8::Value>& args,
                           ->Int32Value(args.GetIsolate()->GetCurrentContext())
                           .FromJust();
     } else {
-      args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-          args.GetIsolate(), "system: Argument 3 must be a number"));
+      args.GetIsolate()->ThrowError("system: Argument 3 must be a number");
       return false;
     }
   }
   return true;
 }
 
+namespace {
+v8::Local<v8::String> v8_strerror(v8::Isolate* isolate, int err) {
+  return v8::String::NewFromUtf8(isolate, strerror(err)).ToLocalChecked();
+}
+}  // namespace
+
 static const int kReadFD = 0;
 static const int kWriteFD = 1;
 
@@ -267,8 +271,7 @@ static bool ChildLaunchedOK(Isolate* isolate, int* exec_error_fds) {
     bytes_read = read(exec_error_fds[kReadFD], &err, sizeof(err));
   } while (bytes_read == -1 && errno == EINTR);
   if (bytes_read != 0) {
-    isolate->ThrowException(
-        String::NewFromUtf8(isolate, strerror(err)).ToLocalChecked());
+    isolate->ThrowError(v8_strerror(isolate, err));
     return false;
   }
   return true;
@@ -286,8 +289,7 @@ static Local<Value> GetStdout(Isolate* isolate, int child_fd,
   char buffer[kStdoutReadBufferSize];
 
   if (fcntl(child_fd, F_SETFL, O_NONBLOCK) != 0) {
-    return isolate->ThrowException(
-        String::NewFromUtf8(isolate, strerror(errno)).ToLocalChecked());
+    return isolate->ThrowError(v8_strerror(isolate, errno));
   }
 
   int bytes_read;
@@ -298,8 +300,7 @@ static Local<Value> GetStdout(Isolate* isolate, int child_fd,
       if (errno == EAGAIN) {
         if (!WaitOnFD(child_fd, read_timeout, total_timeout, start_time) ||
             (TimeIsOut(start_time, total_timeout))) {
-          return isolate->ThrowException(String::NewFromUtf8Literal(
-              isolate, "Timed out waiting for output"));
+          return isolate->ThrowError("Timed out waiting for output");
         }
         continue;
       } else if (errno == EINTR) {
@@ -357,8 +358,7 @@ static bool WaitForChild(Isolate* isolate, int pid,
     if (useconds < 1000000) useconds <<= 1;
     if ((read_timeout != -1 && useconds / 1000 > read_timeout) ||
         (TimeIsOut(start_time, total_timeout))) {
-      isolate->ThrowException(String::NewFromUtf8Literal(
-          isolate, "Timed out waiting for process to terminate"));
+      isolate->ThrowError("Timed out waiting for process to terminate");
       kill(pid, SIGINT);
       return false;
     }
@@ -367,16 +367,14 @@ static bool WaitForChild(Isolate* isolate, int pid,
     char message[999];
     snprintf(message, sizeof(message), "Child killed by signal %d",
              child_info.si_status);
-    isolate->ThrowException(
-        String::NewFromUtf8(isolate, message).ToLocalChecked());
+    isolate->ThrowError(message);
     return false;
   }
   if (child_info.si_code == CLD_EXITED && child_info.si_status != 0) {
     char message[999];
     snprintf(message, sizeof(message), "Child exited with status %d",
              child_info.si_status);
-    isolate->ThrowException(
-        String::NewFromUtf8(isolate, message).ToLocalChecked());
+    isolate->ThrowError(message);
     return false;
   }
 
@@ -389,8 +387,7 @@ static bool WaitForChild(Isolate* isolate, int pid,
     char message[999];
     snprintf(message, sizeof(message), "Child killed by signal %d",
              WTERMSIG(child_status));
-    isolate->ThrowException(
-        String::NewFromUtf8(isolate, message).ToLocalChecked());
+    isolate->ThrowError(message);
     return false;
   }
   if (WEXITSTATUS(child_status) != 0) {
@@ -398,8 +395,7 @@ static bool WaitForChild(Isolate* isolate, int pid,
     int exit_status = WEXITSTATUS(child_status);
     snprintf(message, sizeof(message), "Child exited with status %d",
              exit_status);
-    isolate->ThrowException(
-        String::NewFromUtf8(isolate, message).ToLocalChecked());
+    isolate->ThrowError(message);
     return false;
   }
 
@@ -419,8 +415,7 @@ void Shell::System(const v8::FunctionCallbackInfo<v8::Value>& args) {
   Local<Array> command_args;
   if (args.Length() > 1) {
     if (!args[1]->IsArray()) {
-      args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-          args.GetIsolate(), "system: Argument 2 must be an array"));
+      args.GetIsolate()->ThrowError("system: Argument 2 must be an array");
       return;
     }
     command_args = args[1].As<Array>();
@@ -428,13 +423,11 @@ void Shell::System(const v8::FunctionCallbackInfo<v8::Value>& args) {
     command_args = Array::New(args.GetIsolate(), 0);
   }
   if (command_args->Length() > ExecArgs::kMaxArgs) {
-    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-        args.GetIsolate(), "Too many arguments to system()"));
+    args.GetIsolate()->ThrowError("Too many arguments to system()");
     return;
   }
   if (args.Length() < 1) {
-    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-        args.GetIsolate(), "Too few arguments to system()"));
+    args.GetIsolate()->ThrowError("Too few arguments to system()");
     return;
   }
 
@@ -449,13 +442,11 @@ void Shell::System(const v8::FunctionCallbackInfo<v8::Value>& args) {
   int stdout_fds[2];
 
   if (pipe(exec_error_fds) != 0) {
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8Literal(args.GetIsolate(), "pipe syscall failed."));
+    args.GetIsolate()->ThrowError("pipe syscall failed.");
     return;
   }
   if (pipe(stdout_fds) != 0) {
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8Literal(args.GetIsolate(), "pipe syscall failed."));
+    args.GetIsolate()->ThrowError("pipe syscall failed.");
     return;
   }
 
@@ -493,29 +484,24 @@ void Shell::System(const v8::FunctionCallbackInfo<v8::Value>& args) {
 
 void Shell::ChangeDirectory(const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() != 1) {
-    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-        args.GetIsolate(), "chdir() takes one argument"));
+    args.GetIsolate()->ThrowError("chdir() takes one argument");
     return;
   }
   String::Utf8Value directory(args.GetIsolate(), args[0]);
   if (*directory == nullptr) {
-    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-        args.GetIsolate(),
-        "os.chdir(): String conversion of argument failed."));
+    args.GetIsolate()->ThrowError(
+        "os.chdir(): String conversion of argument failed.");
     return;
   }
   if (chdir(*directory) != 0) {
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), strerror(errno))
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowError(v8_strerror(args.GetIsolate(), errno));
     return;
   }
 }
 
 void Shell::SetUMask(const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() != 1) {
-    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-        args.GetIsolate(), "umask() takes one argument"));
+    args.GetIsolate()->ThrowError("umask() takes one argument");
     return;
   }
   if (args[0]->IsNumber()) {
@@ -524,8 +510,7 @@ void Shell::SetUMask(const v8::FunctionCallbackInfo<v8::Value>& args) {
     args.GetReturnValue().Set(previous);
     return;
   } else {
-    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-        args.GetIsolate(), "umask() argument must be numeric"));
+    args.GetIsolate()->ThrowError("umask() argument must be numeric");
     return;
   }
 }
@@ -534,13 +519,11 @@ static bool CheckItsADirectory(Isolate* isolate, char* directory) {
   struct stat stat_buf;
   int stat_result = stat(directory, &stat_buf);
   if (stat_result != 0) {
-    isolate->ThrowException(
-        String::NewFromUtf8(isolate, strerror(errno)).ToLocalChecked());
+    isolate->ThrowError(v8_strerror(isolate, errno));
     return false;
   }
   if ((stat_buf.st_mode & S_IFDIR) != 0) return true;
-  isolate->ThrowException(
-      String::NewFromUtf8(isolate, strerror(EEXIST)).ToLocalChecked());
+  isolate->ThrowError(v8_strerror(isolate, EEXIST));
   return false;
 }
 
@@ -554,8 +537,7 @@ static bool mkdirp(Isolate* isolate, char* directory, mode_t mask) {
   } else if (errno == ENOENT) {  // Intermediate path element is missing.
     char* last_slash = strrchr(directory, '/');
     if (last_slash == nullptr) {
-      isolate->ThrowException(
-          String::NewFromUtf8(isolate, strerror(errno)).ToLocalChecked());
+      isolate->ThrowError(v8_strerror(isolate, errno));
       return false;
     }
     *last_slash = 0;
@@ -566,12 +548,10 @@ static bool mkdirp(Isolate* isolate, char* directory, mode_t mask) {
     if (errno == EEXIST) {
       return CheckItsADirectory(isolate, directory);
     }
-    isolate->ThrowException(
-        String::NewFromUtf8(isolate, strerror(errno)).ToLocalChecked());
+    isolate->ThrowError(v8_strerror(isolate, errno));
     return false;
   } else {
-    isolate->ThrowException(
-        String::NewFromUtf8(isolate, strerror(errno)).ToLocalChecked());
+    isolate->ThrowError(v8_strerror(isolate, errno));
     return false;
   }
 }
@@ -584,20 +564,17 @@ void Shell::MakeDirectory(const v8::FunctionCallbackInfo<v8::Value>& args) {
                  ->Int32Value(args.GetIsolate()->GetCurrentContext())
                  .FromJust();
     } else {
-      args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-          args.GetIsolate(), "mkdirp() second argument must be numeric"));
+      args.GetIsolate()->ThrowError("mkdirp() second argument must be numeric");
       return;
     }
   } else if (args.Length() != 1) {
-    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-        args.GetIsolate(), "mkdirp() takes one or two arguments"));
+    args.GetIsolate()->ThrowError("mkdirp() takes one or two arguments");
     return;
   }
   String::Utf8Value directory(args.GetIsolate(), args[0]);
   if (*directory == nullptr) {
-    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-        args.GetIsolate(),
-        "os.mkdirp(): String conversion of argument failed."));
+    args.GetIsolate()->ThrowError(
+        "os.mkdirp(): String conversion of argument failed.");
     return;
   }
   mkdirp(args.GetIsolate(), *directory, mask);
@@ -605,15 +582,13 @@ void Shell::MakeDirectory(const v8::FunctionCallbackInfo<v8::Value>& args) {
 
 void Shell::RemoveDirectory(const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() != 1) {
-    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-        args.GetIsolate(), "rmdir() takes one or two arguments"));
+    args.GetIsolate()->ThrowError("rmdir() takes one or two arguments");
     return;
   }
   String::Utf8Value directory(args.GetIsolate(), args[0]);
   if (*directory == nullptr) {
-    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-        args.GetIsolate(),
-        "os.rmdir(): String conversion of argument failed."));
+    args.GetIsolate()->ThrowError(
+        "os.rmdir(): String conversion of argument failed.");
     return;
   }
   rmdir(*directory);
@@ -621,22 +596,19 @@ void Shell::RemoveDirectory(const v8::FunctionCallbackInfo<v8::Value>& args) {
 
 void Shell::SetEnvironment(const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() != 2) {
-    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-        args.GetIsolate(), "setenv() takes two arguments"));
+    args.GetIsolate()->ThrowError("setenv() takes two arguments");
     return;
   }
   String::Utf8Value var(args.GetIsolate(), args[0]);
   String::Utf8Value value(args.GetIsolate(), args[1]);
   if (*var == nullptr) {
-    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-        args.GetIsolate(),
-        "os.setenv(): String conversion of variable name failed."));
+    args.GetIsolate()->ThrowError(
+        "os.setenv(): String conversion of variable name failed.");
     return;
   }
   if (*value == nullptr) {
-    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-        args.GetIsolate(),
-        "os.setenv(): String conversion of variable contents failed."));
+    args.GetIsolate()->ThrowError(
+        "os.setenv(): String conversion of variable contents failed.");
     return;
   }
   setenv(*var, *value, 1);
@@ -644,15 +616,13 @@ void Shell::SetEnvironment(const v8::FunctionCallbackInfo<v8::Value>& args) {
 
 void Shell::UnsetEnvironment(const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() != 1) {
-    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-        args.GetIsolate(), "unsetenv() takes one argument"));
+    args.GetIsolate()->ThrowError("unsetenv() takes one argument");
     return;
   }
   String::Utf8Value var(args.GetIsolate(), args[0]);
   if (*var == nullptr) {
-    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
-        args.GetIsolate(),
-        "os.setenv(): String conversion of variable name failed."));
+    args.GetIsolate()->ThrowError(
+        "os.setenv(): String conversion of variable name failed.");
     return;
   }
   unsetenv(*var);
diff --git a/chromium/v8/src/d8/d8-test.cc b/chromium/v8/src/d8/d8-test.cc
index e5eb5e419bf..741b838b760 100644
--- a/chromium/v8/src/d8/d8-test.cc
+++ b/chromium/v8/src/d8/d8-test.cc
@@ -21,16 +21,29 @@
 
 namespace v8 {
 namespace {
+
+#define CHECK_SELF_OR_FALLBACK(return_value) \
+  if (!self) {                               \
+    options.fallback = 1;                    \
+    return return_value;                     \
+  }
+
+#define CHECK_SELF_OR_THROW()                                               \
+  if (!self) {                                                              \
+    args.GetIsolate()->ThrowError(                                          \
+        "This method is not defined on objects inheriting from FastCAPI."); \
+    return;                                                                 \
+  }
+
 class FastCApiObject {
  public:
-  static double AddAllFastCallback(ApiObject receiver, bool should_fallback,
+  static double AddAllFastCallback(Local<Object> receiver, bool should_fallback,
                                    int32_t arg_i32, uint32_t arg_u32,
                                    int64_t arg_i64, uint64_t arg_u64,
                                    float arg_f32, double arg_f64,
                                    FastApiCallbackOptions& options) {
-    Value* receiver_value = reinterpret_cast<Value*>(&receiver);
-    CHECK(receiver_value->IsObject());
-    FastCApiObject* self = UnwrapObject(Object::Cast(receiver_value));
+    FastCApiObject* self = UnwrapObject(receiver);
+    CHECK_SELF_OR_FALLBACK(0);
     self->fast_call_count_++;
 
     if (should_fallback) {
@@ -42,33 +55,42 @@ class FastCApiObject {
            static_cast<double>(arg_i64) + static_cast<double>(arg_u64) +
            static_cast<double>(arg_f32) + arg_f64;
   }
+  static double AddAllFastCallback_5Args(Local<Object> receiver,
+                                         bool should_fallback, int32_t arg_i32,
+                                         uint32_t arg_u32, int64_t arg_i64,
+                                         uint64_t arg_u64, float arg_f32,
+                                         FastApiCallbackOptions& options) {
+    return AddAllFastCallback(receiver, should_fallback, arg_i32, arg_u32,
+                              arg_i64, arg_u64, arg_f32, 0, options);
+  }
   static void AddAllSlowCallback(const FunctionCallbackInfo<Value>& args) {
     Isolate* isolate = args.GetIsolate();
 
-    FastCApiObject* self = UnwrapObject(*args.This());
+    FastCApiObject* self = UnwrapObject(args.This());
+    CHECK_SELF_OR_THROW();
     self->slow_call_count_++;
 
     HandleScope handle_scope(isolate);
 
     double sum = 0;
-    if (args.Length() > 1) {
+    if (args.Length() > 1 && args[1]->IsNumber()) {
       sum += args[1]->Int32Value(isolate->GetCurrentContext()).FromJust();
     }
-    if (args.Length() > 2) {
+    if (args.Length() > 2 && args[2]->IsNumber()) {
       sum += args[2]->Uint32Value(isolate->GetCurrentContext()).FromJust();
     }
-    if (args.Length() > 3) {
+    if (args.Length() > 3 && args[3]->IsNumber()) {
       sum += args[3]->IntegerValue(isolate->GetCurrentContext()).FromJust();
     }
-    if (args.Length() > 4) {
+    if (args.Length() > 4 && args[4]->IsNumber()) {
       sum += args[4]->IntegerValue(isolate->GetCurrentContext()).FromJust();
     }
-    if (args.Length() > 5) {
+    if (args.Length() > 5 && args[5]->IsNumber()) {
       sum += args[5]->NumberValue(isolate->GetCurrentContext()).FromJust();
     } else {
       sum += std::numeric_limits<double>::quiet_NaN();
     }
-    if (args.Length() > 6) {
+    if (args.Length() > 6 && args[6]->IsNumber()) {
       sum += args[6]->NumberValue(isolate->GetCurrentContext()).FromJust();
     } else {
       sum += std::numeric_limits<double>::quiet_NaN();
@@ -77,12 +99,12 @@ class FastCApiObject {
     args.GetReturnValue().Set(Number::New(isolate, sum));
   }
 
-  static int Add32BitIntFastCallback(ApiObject receiver, bool should_fallback,
-                                     int32_t arg_i32, uint32_t arg_u32,
+  static int Add32BitIntFastCallback(v8::Local<v8::Object> receiver,
+                                     bool should_fallback, int32_t arg_i32,
+                                     uint32_t arg_u32,
                                      FastApiCallbackOptions& options) {
-    Value* receiver_value = reinterpret_cast<Value*>(&receiver);
-    CHECK(receiver_value->IsObject());
-    FastCApiObject* self = UnwrapObject(Object::Cast(receiver_value));
+    FastCApiObject* self = UnwrapObject(receiver);
+    CHECK_SELF_OR_FALLBACK(0);
     self->fast_call_count_++;
 
     if (should_fallback) {
@@ -95,40 +117,104 @@ class FastCApiObject {
   static void Add32BitIntSlowCallback(const FunctionCallbackInfo<Value>& args) {
     Isolate* isolate = args.GetIsolate();
 
-    FastCApiObject* self = UnwrapObject(*args.This());
+    FastCApiObject* self = UnwrapObject(args.This());
+    CHECK_SELF_OR_THROW();
     self->slow_call_count_++;
 
     HandleScope handle_scope(isolate);
 
     double sum = 0;
-    if (args.Length() > 1) {
+    if (args.Length() > 1 && args[1]->IsNumber()) {
       sum += args[1]->Int32Value(isolate->GetCurrentContext()).FromJust();
     }
-    if (args.Length() > 2) {
+    if (args.Length() > 2 && args[2]->IsNumber()) {
       sum += args[2]->Uint32Value(isolate->GetCurrentContext()).FromJust();
     }
 
     args.GetReturnValue().Set(Number::New(isolate, sum));
   }
 
+  static bool IsFastCApiObjectFastCallback(v8::Local<v8::Object> receiver,
+                                           bool should_fallback,
+                                           v8::Local<v8::Value> arg,
+                                           FastApiCallbackOptions& options) {
+    FastCApiObject* self = UnwrapObject(receiver);
+    CHECK_SELF_OR_FALLBACK(false);
+    self->fast_call_count_++;
+
+    if (should_fallback) {
+      options.fallback = 1;
+      return false;
+    }
+
+    if (!arg->IsObject()) {
+      return false;
+    }
+    Local<Object> object = arg.As<Object>();
+    if (!IsValidApiObject(object)) return false;
+
+    internal::Isolate* i_isolate =
+        internal::IsolateFromNeverReadOnlySpaceObject(
+            *reinterpret_cast<internal::Address*>(*object));
+    CHECK_NOT_NULL(i_isolate);
+    Isolate* isolate = reinterpret_cast<Isolate*>(i_isolate);
+    HandleScope handle_scope(isolate);
+    return PerIsolateData::Get(isolate)
+        ->GetTestApiObjectCtor()
+        ->IsLeafTemplateForApiObject(object);
+  }
+  static void IsFastCApiObjectSlowCallback(
+      const FunctionCallbackInfo<Value>& args) {
+    Isolate* isolate = args.GetIsolate();
+
+    FastCApiObject* self = UnwrapObject(args.This());
+    CHECK_SELF_OR_THROW();
+    self->slow_call_count_++;
+
+    HandleScope handle_scope(isolate);
+
+    bool result = false;
+    if (args.Length() < 2) {
+      args.GetIsolate()->ThrowError(
+          "is_valid_api_object should be called with 2 arguments");
+      return;
+    }
+    if (args[1]->IsObject()) {
+      Local<Object> object = args[1].As<Object>();
+      if (!IsValidApiObject(object)) {
+        result = false;
+      } else {
+        result = PerIsolateData::Get(args.GetIsolate())
+                     ->GetTestApiObjectCtor()
+                     ->IsLeafTemplateForApiObject(object);
+      }
+    }
+
+    args.GetReturnValue().Set(Boolean::New(isolate, result));
+  }
+
   static void FastCallCount(const FunctionCallbackInfo<Value>& args) {
-    FastCApiObject* self = UnwrapObject(*args.This());
+    FastCApiObject* self = UnwrapObject(args.This());
+    CHECK_SELF_OR_THROW();
     args.GetReturnValue().Set(
         Number::New(args.GetIsolate(), self->fast_call_count()));
   }
   static void SlowCallCount(const FunctionCallbackInfo<Value>& args) {
-    FastCApiObject* self = UnwrapObject(*args.This());
+    FastCApiObject* self = UnwrapObject(args.This());
+    CHECK_SELF_OR_THROW();
     args.GetReturnValue().Set(
         Number::New(args.GetIsolate(), self->slow_call_count()));
   }
   static void ResetCounts(const FunctionCallbackInfo<Value>& args) {
-    FastCApiObject* self = UnwrapObject(*args.This());
+    FastCApiObject* self = UnwrapObject(args.This());
+    CHECK_SELF_OR_THROW();
     self->reset_counts();
     args.GetReturnValue().Set(Undefined(args.GetIsolate()));
   }
-  static void SupportsFPParams(const FunctionCallbackInfo<Value>& info) {
-    FastCApiObject* self = UnwrapObject(*info.This());
-    info.GetReturnValue().Set(self->supports_fp_params_);
+  static void SupportsFPParams(const FunctionCallbackInfo<Value>& args) {
+    FastCApiObject* self = UnwrapObject(args.This());
+    CHECK_SELF_OR_THROW();
+    args.GetReturnValue().Set(self->supports_fp_params_);
   }
 
   int fast_call_count() const { return fast_call_count_; }
@@ -141,12 +227,14 @@ class FastCApiObject {
   static const int kV8WrapperObjectIndex = 1;
 
  private:
-  static FastCApiObject* UnwrapObject(Object* object) {
-    i::Address addr = *reinterpret_cast<i::Address*>(object);
+  static bool IsValidApiObject(Local<Object> object) {
+    i::Address addr = *reinterpret_cast<i::Address*>(*object);
     auto instance_type = i::Internals::GetInstanceType(addr);
-    if (instance_type != i::Internals::kJSObjectType &&
-        instance_type != i::Internals::kJSApiObjectType &&
-        instance_type != i::Internals::kJSSpecialApiObjectType) {
+    return (instance_type == i::Internals::kJSApiObjectType ||
+            instance_type == i::Internals::kJSSpecialApiObjectType);
+  }
+  static FastCApiObject* UnwrapObject(Local<Object> object) {
+    if (!IsValidApiObject(object)) {
       return nullptr;
     }
     FastCApiObject* wrapped = reinterpret_cast<FastCApiObject*>(
@@ -162,18 +250,18 @@ class FastCApiObject {
 #endif  // V8_ENABLE_FP_PARAMS_IN_C_LINKAGE
 };
 
+#undef CHECK_SELF_OR_THROW
+#undef CHECK_SELF_OR_FALLBACK
+
 // The object is statically initialized for simplicity, typically the embedder
 // will take care of managing their C++ objects lifetime.
 thread_local FastCApiObject kFastCApiObject;
 }  // namespace
 
-// TODO(mslekova): Rename the fast_c_api helper to FastCAPI.
-void CreateObject(const FunctionCallbackInfo<Value>& info) {
+void CreateFastCAPIObject(const FunctionCallbackInfo<Value>& info) {
   if (!info.IsConstructCall()) {
-    info.GetIsolate()->ThrowException(
-        v8::Exception::Error(String::NewFromUtf8Literal(
-            info.GetIsolate(),
-            "FastCAPI helper must be constructed with new.")));
+    info.GetIsolate()->ThrowError(
+        "FastCAPI helper must be constructed with new.");
     return;
   }
   Local<Object> api_object = info.Holder();
@@ -189,7 +277,8 @@ void CreateObject(const FunctionCallbackInfo<Value>& info) {
 
 Local<FunctionTemplate> Shell::CreateTestFastCApiTemplate(Isolate* isolate) {
   Local<FunctionTemplate> api_obj_ctor =
-      FunctionTemplate::New(isolate, CreateObject);
+      FunctionTemplate::New(isolate, CreateFastCAPIObject);
+  PerIsolateData::Get(isolate)->SetTestApiObjectCtor(api_obj_ctor);
   Local<Signature> signature = Signature::New(isolate, api_obj_ctor);
   {
     CFunction add_all_c_func =
@@ -200,6 +289,19 @@ Local<FunctionTemplate> Shell::CreateTestFastCApiTemplate(Isolate* isolate) {
                               Local<Value>(), signature, 1,
                               ConstructorBehavior::kThrow,
                               SideEffectType::kHasSideEffect, &add_all_c_func));
+
+    // To test function overloads.
+    CFunction add_all_5args_c_func =
+        CFunction::Make(FastCApiObject::AddAllFastCallback_5Args);
+    const CFunction c_function_overloads[] = {add_all_c_func,
+                                              add_all_5args_c_func};
+    api_obj_ctor->PrototypeTemplate()->Set(
+        isolate, "overloaded_add_all",
+        FunctionTemplate::NewWithCFunctionOverloads(
+            isolate, FastCApiObject::AddAllSlowCallback, Local<Value>(),
+            signature, 1, ConstructorBehavior::kThrow,
+            SideEffectType::kHasSideEffect, {c_function_overloads, 2}));
+
     CFunction add_32bit_int_c_func =
         CFunction::Make(FastCApiObject::Add32BitIntFastCallback);
     api_obj_ctor->PrototypeTemplate()->Set(
@@ -208,6 +310,14 @@ Local<FunctionTemplate> Shell::CreateTestFastCApiTemplate(Isolate* isolate) {
             isolate, FastCApiObject::Add32BitIntSlowCallback, Local<Value>(),
             signature, 1, ConstructorBehavior::kThrow,
             SideEffectType::kHasSideEffect, &add_32bit_int_c_func));
+    CFunction is_valid_api_object_c_func =
+        CFunction::Make(FastCApiObject::IsFastCApiObjectFastCallback);
+    api_obj_ctor->PrototypeTemplate()->Set(
+        isolate, "is_fast_c_api_object",
+        FunctionTemplate::New(
+            isolate, FastCApiObject::IsFastCApiObjectSlowCallback,
+            Local<Value>(), signature, 1, ConstructorBehavior::kThrow,
+            SideEffectType::kHasSideEffect, &is_valid_api_object_c_func));
     api_obj_ctor->PrototypeTemplate()->Set(
         isolate, "fast_call_count",
         FunctionTemplate::New(isolate, FastCApiObject::FastCallCount,
@@ -227,4 +337,20 @@ Local<FunctionTemplate> Shell::CreateTestFastCApiTemplate(Isolate* isolate) {
   return api_obj_ctor;
 }
 
+void CreateLeafInterfaceObject(const FunctionCallbackInfo<Value>& info) {
+  if (!info.IsConstructCall()) {
+    info.GetIsolate()->ThrowError(
+        "LeafInterfaceType helper must be constructed with new.");
+  }
+}
+
+Local<FunctionTemplate> Shell::CreateLeafInterfaceTypeTemplate(
+    Isolate* isolate) {
+  Local<FunctionTemplate> leaf_object_ctor =
+      FunctionTemplate::New(isolate, CreateLeafInterfaceObject);
+  leaf_object_ctor->SetClassName(
+      String::NewFromUtf8Literal(isolate, "LeafInterfaceType"));
+  return leaf_object_ctor;
+}
+
 }  // namespace v8
diff --git a/chromium/v8/src/d8/d8.cc b/chromium/v8/src/d8/d8.cc
index d13e424bb15..8c9a4c3ae60 100644
--- a/chromium/v8/src/d8/d8.cc
+++ b/chromium/v8/src/d8/d8.cc
@@ -32,6 +32,7 @@
 #include "src/base/platform/platform.h"
 #include "src/base/platform/time.h"
 #include "src/base/platform/wrappers.h"
+#include "src/base/sanitizer/msan.h"
 #include "src/base/sys-info.h"
 #include "src/d8/d8-console.h"
 #include "src/d8/d8-platforms.h"
@@ -53,7 +54,6 @@
 #include "src/parsing/parsing.h"
 #include "src/parsing/scanner-character-streams.h"
 #include "src/profiler/profile-generator.h"
-#include "src/sanitizer/msan.h"
 #include "src/snapshot/snapshot.h"
 #include "src/tasks/cancelable-task.h"
 #include "src/trap-handler/trap-handler.h"
@@ -333,11 +333,6 @@ class MultiMappedAllocator : public ArrayBufferAllocatorBase {
 v8::Platform* g_default_platform;
 std::unique_ptr<v8::Platform> g_platform;
 
-static Local<Value> Throw(Isolate* isolate, const char* message) {
-  return isolate->ThrowException(v8::Exception::Error(
-      String::NewFromUtf8(isolate, message).ToLocalChecked()));
-}
-
 static MaybeLocal<Value> TryGetValue(v8::Isolate* isolate,
                                      Local<Context> context,
                                      Local<v8::Object> object,
@@ -355,13 +350,13 @@ static Local<Value> GetValue(v8::Isolate* isolate, Local<Context> context,
 std::shared_ptr<Worker> GetWorkerFromInternalField(Isolate* isolate,
                                                    Local<Object> object) {
   if (object->InternalFieldCount() != 1) {
-    Throw(isolate, "this is not a Worker");
+    isolate->ThrowError("this is not a Worker");
     return nullptr;
   }
 
   i::Handle<i::Object> handle = Utils::OpenHandle(*object->GetInternalField(0));
   if (handle->IsSmi()) {
-    Throw(isolate, "Worker is defunct because main thread is terminating");
+    isolate->ThrowError("Worker is defunct because main thread is terminating");
     return nullptr;
   }
   auto managed = i::Handle<i::Managed<Worker>>::cast(handle);
@@ -696,6 +691,12 @@ bool Shell::ExecuteString(Isolate* isolate, Local<String> source,
     Local<Context> context(isolate->GetCurrentContext());
     ScriptOrigin origin(isolate, name);
 
+    for (int i = 1; i < options.repeat_compile; ++i) {
+      HandleScope handle_scope(isolate);
+      if (CompileString<Script>(isolate, context, source, origin).IsEmpty()) {
+        return false;
+      }
+    }
     Local<Script> script;
     if (!CompileString<Script>(isolate, context, source, origin)
              .ToLocal(&script)) {
@@ -710,6 +711,9 @@ bool Shell::ExecuteString(Isolate* isolate, Local<String> source,
       StoreInCodeCache(isolate, source, cached_data);
       delete cached_data;
     }
+    if (options.compile_only) {
+      return true;
+    }
     maybe_result = script->Run(realm);
     if (options.code_cache_options ==
         ShellOptions::CodeCacheOptions::kProduceCacheAfterExecute) {
@@ -728,7 +732,7 @@ bool Shell::ExecuteString(Isolate* isolate, Local<String> source,
     if (options.web_snapshot_config) {
       std::vector<std::string> exports;
       if (!ReadLines(options.web_snapshot_config, exports)) {
-        Throw(isolate, "Web snapshots: unable to read config");
+        isolate->ThrowError("Web snapshots: unable to read config");
         CHECK(try_catch.HasCaught());
         ReportException(isolate, &try_catch);
         return false;
@@ -965,7 +969,8 @@ MaybeLocal<Module> Shell::FetchModuleTree(Local<Module> referrer,
       CHECK(specifier_it != d->module_to_specifier_map.end());
       msg += "\n    imported by " + specifier_it->second;
     }
-    Throw(isolate, msg.c_str());
+    isolate->ThrowError(
+        v8::String::NewFromUtf8(isolate, msg.c_str()).ToLocalChecked());
     return MaybeLocal<Module>();
   }
   ScriptOrigin origin(
@@ -1024,7 +1029,7 @@ MaybeLocal<Module> Shell::FetchModuleTree(Local<Module> referrer,
             context, import_assertions, true);
 
     if (request_module_type == ModuleType::kInvalid) {
-      Throw(isolate, "Invalid module type was asserted");
+      isolate->ThrowError("Invalid module type was asserted");
       return MaybeLocal<Module>();
     }
 
@@ -1211,7 +1216,7 @@ void Shell::DoHostImportModuleDynamically(void* import_data) {
   try_catch.SetVerbose(true);
 
   if (module_type == ModuleType::kInvalid) {
-    Throw(isolate, "Invalid module type was asserted");
+    isolate->ThrowError("Invalid module type was asserted");
     CHECK(try_catch.HasCaught());
     resolver->Reject(realm, try_catch.Exception()).ToChecked();
     return;
@@ -1358,7 +1363,7 @@ bool Shell::ExecuteWebSnapshot(Isolate* isolate, const char* file_name) {
   std::unique_ptr<uint8_t[]> snapshot_data(
       reinterpret_cast<uint8_t*>(ReadChars(absolute_path.c_str(), &length)));
   if (length == 0) {
-    Throw(isolate, "Error reading the web snapshot");
+    isolate->ThrowError("Error reading the web snapshot");
     DCHECK(try_catch.HasCaught());
     ReportException(isolate, &try_catch);
     return false;
@@ -1468,6 +1473,14 @@ void PerIsolateData::DeleteDynamicImportData(DynamicImportData* data) {
   delete data;
 }
 
+Local<FunctionTemplate> PerIsolateData::GetTestApiObjectCtor() const {
+  return test_api_object_ctor_.Get(isolate_);
+}
+
+void PerIsolateData::SetTestApiObjectCtor(Local<FunctionTemplate> ctor) {
+  test_api_object_ctor_.Reset(isolate_, ctor);
+}
+
 PerIsolateData::RealmScope::RealmScope(PerIsolateData* data) : data_(data) {
   data_->realm_count_ = 1;
   data_->realm_current_ = 0;
@@ -1500,14 +1513,14 @@ int PerIsolateData::RealmFind(Local<Context> context) {
 int PerIsolateData::RealmIndexOrThrow(
     const v8::FunctionCallbackInfo<v8::Value>& args, int arg_offset) {
   if (args.Length() < arg_offset || !args[arg_offset]->IsNumber()) {
-    Throw(args.GetIsolate(), "Invalid argument");
+    args.GetIsolate()->ThrowError("Invalid argument");
     return -1;
   }
   int index = args[arg_offset]
                   ->Int32Value(args.GetIsolate()->GetCurrentContext())
                   .FromMaybe(-1);
   if (index < 0 || index >= realm_count_ || realms_[index].IsEmpty()) {
-    Throw(args.GetIsolate(), "Invalid realm index");
+    args.GetIsolate()->ThrowError("Invalid realm index");
     return -1;
   }
   return index;
@@ -1565,7 +1578,7 @@ void Shell::RealmOwner(const v8::FunctionCallbackInfo<v8::Value>& args) {
   Isolate* isolate = args.GetIsolate();
   PerIsolateData* data = PerIsolateData::Get(isolate);
   if (args.Length() < 1 || !args[0]->IsObject()) {
-    Throw(args.GetIsolate(), "Invalid argument");
+    args.GetIsolate()->ThrowError("Invalid argument");
     return;
   }
   Local<Object> object =
@@ -1577,7 +1590,7 @@ void Shell::RealmOwner(const v8::FunctionCallbackInfo<v8::Value>& args) {
   }
   Local<Context> creation_context;
   if (!object->GetCreationContext().ToLocal(&creation_context)) {
-    Throw(args.GetIsolate(), "object doesn't have creation context");
+    args.GetIsolate()->ThrowError("object doesn't have creation context");
     return;
   }
   int index = data->RealmFind(creation_context);
@@ -1661,7 +1674,7 @@ void Shell::RealmNavigate(const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (index == -1) return;
   if (index == 0 || index == data->realm_current_ ||
       index == data->realm_switch_) {
-    Throw(args.GetIsolate(), "Invalid realm index");
+    args.GetIsolate()->ThrowError("Invalid realm index");
     return;
   }
 
@@ -1690,7 +1703,7 @@ void Shell::RealmDetachGlobal(const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (index == -1) return;
   if (index == 0 || index == data->realm_current_ ||
       index == data->realm_switch_) {
-    Throw(args.GetIsolate(), "Invalid realm index");
+    args.GetIsolate()->ThrowError("Invalid realm index");
     return;
   }
 
@@ -1707,7 +1720,7 @@ void Shell::RealmDispose(const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (index == -1) return;
   if (index == 0 || index == data->realm_current_ ||
       index == data->realm_switch_) {
-    Throw(args.GetIsolate(), "Invalid realm index");
+    args.GetIsolate()->ThrowError("Invalid realm index");
     return;
   }
   DisposeRealm(args, index);
@@ -1729,7 +1742,7 @@ void Shell::RealmEval(const v8::FunctionCallbackInfo<v8::Value>& args) {
   int index = data->RealmIndexOrThrow(args, 0);
   if (index == -1) return;
   if (args.Length() < 2 || !args[1]->IsString()) {
-    Throw(args.GetIsolate(), "Invalid argument");
+    args.GetIsolate()->ThrowError("Invalid argument");
     return;
   }
   ScriptOrigin origin(isolate,
@@ -1780,18 +1793,18 @@ void Shell::LogGetAndStop(const v8::FunctionCallbackInfo<v8::Value>& args) {
 
   std::string file_name = i_isolate->logger()->file_name();
   if (!i::Log::IsLoggingToTemporaryFile(file_name)) {
-    Throw(isolate, "Only capturing from temporary files is supported.");
+    isolate->ThrowError("Only capturing from temporary files is supported.");
     return;
   }
   if (!i_isolate->logger()->is_logging()) {
-    Throw(isolate, "Logging not enabled.");
+    isolate->ThrowError("Logging not enabled.");
     return;
   }
 
   std::string raw_log;
   FILE* log_file = i_isolate->logger()->TearDownAndGetLogFile();
   if (!log_file) {
-    Throw(isolate, "Log file does not exist.");
+    isolate->ThrowError("Log file does not exist.");
     return;
   }
 
@@ -1800,7 +1813,7 @@ void Shell::LogGetAndStop(const v8::FunctionCallbackInfo<v8::Value>& args) {
   base::Fclose(log_file);
 
   if (!exists) {
-    Throw(isolate, "Unable to read log file.");
+    isolate->ThrowError("Unable to read log file.");
     return;
   }
   Local<String> result =
@@ -1816,13 +1829,13 @@ void Shell::TestVerifySourcePositions(
   Isolate* isolate = args.GetIsolate();
   // Check if the argument is a valid function.
   if (args.Length() != 1) {
-    Throw(isolate, "Expected function as single argument.");
+    isolate->ThrowError("Expected function as single argument.");
     return;
   }
   auto arg_handle = Utils::OpenHandle(*args[0]);
   if (!arg_handle->IsHeapObject() || !i::Handle<i::HeapObject>::cast(arg_handle)
                                           ->IsJSFunctionOrBoundFunction()) {
-    Throw(isolate, "Expected function as single argument.");
+    isolate->ThrowError("Expected function as single argument.");
     return;
   }
 
@@ -1839,7 +1852,7 @@ void Shell::TestVerifySourcePositions(
 
   i::Handle<i::JSFunction> function = i::Handle<i::JSFunction>::cast(callable);
   if (!function->shared().HasBytecodeArray()) {
-    Throw(isolate, "Function has no BytecodeArray attached.");
+    isolate->ThrowError("Function has no BytecodeArray attached.");
     return;
   }
   i::Handle<i::BytecodeArray> bytecodes =
@@ -1865,7 +1878,7 @@ void Shell::TestVerifySourcePositions(
     if (has_baseline) {
       if (offset_iterator->current_bytecode_offset() !=
           bytecode_iterator.current_offset()) {
-        Throw(isolate, "Baseline bytecode offset mismatch.");
+        isolate->ThrowError("Baseline bytecode offset mismatch.");
         return;
       }
       // Check that we map every address to this bytecode correctly.
@@ -1877,7 +1890,8 @@ void Shell::TestVerifySourcePositions(
         pc_lookup.AdvanceToPCOffset(pc);
         if (pc_lookup.current_bytecode_offset() !=
             bytecode_iterator.current_offset()) {
-          Throw(isolate, "Baseline bytecode offset mismatch for PC lookup.");
+          isolate->ThrowError(
+              "Baseline bytecode offset mismatch for PC lookup.");
           return;
         }
       }
@@ -1885,14 +1899,14 @@ void Shell::TestVerifySourcePositions(
     bytecode_iterator.Advance();
     if (has_baseline && !bytecode_iterator.done()) {
       if (offset_iterator->done()) {
-        Throw(isolate, "Missing bytecode(s) in baseline offset mapping.");
+        isolate->ThrowError("Missing bytecode(s) in baseline offset mapping.");
         return;
       }
       offset_iterator->Advance();
     }
   }
   if (has_baseline && !offset_iterator->done()) {
-    Throw(isolate, "Excess offsets in baseline offset mapping.");
+    isolate->ThrowError("Excess offsets in baseline offset mapping.");
     return;
   }
 }
@@ -1926,6 +1940,27 @@ void Shell::AsyncHooksTriggerAsyncId(
       PerIsolateData::Get(isolate)->GetAsyncHooks()->GetTriggerAsyncId()));
 }
 
+void Shell::SetPromiseHooks(const v8::FunctionCallbackInfo<v8::Value>& args) {
+  Isolate* isolate = args.GetIsolate();
+  if (i::FLAG_correctness_fuzzer_suppressions) {
+    // Make sure we have no pending promises if correctness fuzzing is active.
+    // Due to fast-paths we might have not created all intermediate promises
+    // that aren't spec visible. However, the promise hook might expose them
+    // and cause different output.
+    isolate->PerformMicrotaskCheckpoint();
+  }
+  Local<Context> context = isolate->GetCurrentContext();
+  HandleScope handle_scope(isolate);
+
+  context->SetPromiseHooks(
+    args[0]->IsFunction() ? args[0].As<Function>() : Local<Function>(),
+    args[1]->IsFunction() ? args[1].As<Function>() : Local<Function>(),
+    args[2]->IsFunction() ? args[2].As<Function>() : Local<Function>(),
+    args[3]->IsFunction() ? args[3].As<Function>() : Local<Function>());
+
+  args.GetReturnValue().Set(v8::Undefined(isolate));
+}
+
 void WriteToFile(FILE* file, const v8::FunctionCallbackInfo<v8::Value>& args) {
   for (int i = 0; i < args.Length(); i++) {
     HandleScope handle_scope(args.GetIsolate());
@@ -1939,7 +1974,7 @@ void WriteToFile(FILE* file, const v8::FunctionCallbackInfo<v8::Value>& args) {
     Local<String> str_obj;
 
     if (arg->IsSymbol()) {
-      arg = arg.As<Symbol>()->Description();
+      arg = arg.As<Symbol>()->Description(args.GetIsolate());
     }
     if (!arg->ToString(args.GetIsolate()->GetCurrentContext())
              .ToLocal(&str_obj)) {
@@ -1978,7 +2013,7 @@ void Shell::Write(const v8::FunctionCallbackInfo<v8::Value>& args) {
 void Shell::Read(const v8::FunctionCallbackInfo<v8::Value>& args) {
   String::Utf8Value file(args.GetIsolate(), args[0]);
   if (*file == nullptr) {
-    Throw(args.GetIsolate(), "Error loading file");
+    args.GetIsolate()->ThrowError("Error loading file");
     return;
   }
   if (args.Length() == 2) {
@@ -1990,7 +2025,7 @@ void Shell::Read(const v8::FunctionCallbackInfo<v8::Value>& args) {
   }
   Local<String> source = ReadFile(args.GetIsolate(), *file);
   if (source.IsEmpty()) {
-    Throw(args.GetIsolate(), "Error loading file");
+    args.GetIsolate()->ThrowError("Error loading file");
     return;
   }
   args.GetReturnValue().Set(source);
@@ -2038,12 +2073,12 @@ void Shell::Load(const v8::FunctionCallbackInfo<v8::Value>& args) {
     HandleScope handle_scope(args.GetIsolate());
     String::Utf8Value file(args.GetIsolate(), args[i]);
     if (*file == nullptr) {
-      Throw(args.GetIsolate(), "Error loading file");
+      args.GetIsolate()->ThrowError("Error loading file");
       return;
     }
     Local<String> source = ReadFile(args.GetIsolate(), *file);
     if (source.IsEmpty()) {
-      Throw(args.GetIsolate(), "Error loading file");
+      args.GetIsolate()->ThrowError("Error loading file");
       return;
     }
     if (!ExecuteString(
@@ -2052,7 +2087,7 @@ void Shell::Load(const v8::FunctionCallbackInfo<v8::Value>& args) {
             kNoPrintResult,
             options.quiet_load ? kNoReportExceptions : kReportExceptions,
             kNoProcessMessageQueue)) {
-      Throw(args.GetIsolate(), "Error executing file");
+      args.GetIsolate()->ThrowError("Error executing file");
       return;
     }
   }
@@ -2115,7 +2150,7 @@ bool FunctionAndArgumentsToString(Local<Function> function,
       function->FunctionProtoToString(context);
   Local<String> function_string;
   if (!maybe_function_string.ToLocal(&function_string)) {
-    Throw(isolate, "Failed to convert function to string");
+    isolate->ThrowError("Failed to convert function to string");
     return false;
   }
   *source = String::NewFromUtf8Literal(isolate, "(");
@@ -2124,7 +2159,7 @@ bool FunctionAndArgumentsToString(Local<Function> function,
   *source = String::Concat(isolate, *source, middle);
   if (!arguments.IsEmpty() && !arguments->IsUndefined()) {
     if (!arguments->IsArray()) {
-      Throw(isolate, "'arguments' must be an array");
+      isolate->ThrowError("'arguments' must be an array");
       return false;
     }
     Local<String> comma = String::NewFromUtf8Literal(isolate, ",");
@@ -2136,12 +2171,12 @@ bool FunctionAndArgumentsToString(Local<Function> function,
       MaybeLocal<Value> maybe_argument = array->Get(context, i);
       Local<Value> argument;
       if (!maybe_argument.ToLocal(&argument)) {
-        Throw(isolate, "Failed to get argument");
+        isolate->ThrowError("Failed to get argument");
         return false;
       }
       Local<String> argument_string;
       if (!JSON::Stringify(context, argument).ToLocal(&argument_string)) {
-        Throw(isolate, "Failed to convert argument to string");
+        isolate->ThrowError("Failed to convert argument to string");
         return false;
       }
       *source = String::Concat(isolate, *source, argument_string);
@@ -2156,7 +2191,7 @@ void Shell::WorkerNew(const v8::FunctionCallbackInfo<v8::Value>& args) {
   Isolate* isolate = args.GetIsolate();
   HandleScope handle_scope(isolate);
   if (args.Length() < 1 || (!args[0]->IsString() && !args[0]->IsFunction())) {
-    Throw(isolate, "1st argument must be a string or a function");
+    isolate->ThrowError("1st argument must be a string or a function");
     return;
   }
 
@@ -2170,7 +2205,7 @@ void Shell::WorkerNew(const v8::FunctionCallbackInfo<v8::Value>& args) {
     Local<Value> arguments;
     ReadWorkerTypeAndArguments(args, &worker_type, &arguments);
     if (worker_type != WorkerType::kFunction) {
-      Throw(isolate, "Invalid or missing worker type");
+      isolate->ThrowError("Invalid or missing worker type");
       return;
     }
 
@@ -2189,7 +2224,7 @@ void Shell::WorkerNew(const v8::FunctionCallbackInfo<v8::Value>& args) {
       load_from_file = false;
     } else if (worker_type != WorkerType::kNone &&
                worker_type != WorkerType::kClassic) {
-      Throw(isolate, "Invalid worker type");
+      isolate->ThrowError("Invalid worker type");
       return;
     }
 
@@ -2197,7 +2232,7 @@ void Shell::WorkerNew(const v8::FunctionCallbackInfo<v8::Value>& args) {
       String::Utf8Value filename(isolate, args[0]);
       source = ReadFile(isolate, *filename);
       if (source.IsEmpty()) {
-        Throw(args.GetIsolate(), "Error loading worker script");
+        args.GetIsolate()->ThrowError("Error loading worker script");
         return;
       }
     } else {
@@ -2206,7 +2241,7 @@ void Shell::WorkerNew(const v8::FunctionCallbackInfo<v8::Value>& args) {
   }
 
   if (!args.IsConstructCall()) {
-    Throw(isolate, "Worker must be constructed with new");
+    isolate->ThrowError("Worker must be constructed with new");
     return;
   }
 
@@ -2223,7 +2258,7 @@ void Shell::WorkerNew(const v8::FunctionCallbackInfo<v8::Value>& args) {
 
     String::Utf8Value script(isolate, source);
     if (!*script) {
-      Throw(isolate, "Can't get worker script");
+      isolate->ThrowError("Can't get worker script");
       return;
     }
 
@@ -2237,7 +2272,7 @@ void Shell::WorkerNew(const v8::FunctionCallbackInfo<v8::Value>& args) {
         i_isolate, kWorkerSizeEstimate, worker);
     args.Holder()->SetInternalField(0, Utils::ToLocal(managed));
     if (!Worker::StartWorkerThread(std::move(worker))) {
-      Throw(isolate, "Can't start thread");
+      isolate->ThrowError("Can't start thread");
       return;
     }
   }
@@ -2248,7 +2283,7 @@ void Shell::WorkerPostMessage(const v8::FunctionCallbackInfo<v8::Value>& args) {
   HandleScope handle_scope(isolate);
 
   if (args.Length() < 1) {
-    Throw(isolate, "Invalid argument");
+    isolate->ThrowError("Invalid argument");
     return;
   }
 
@@ -2557,6 +2592,33 @@ Local<String> Shell::Stringify(Isolate* isolate, Local<Value> value) {
   return result.ToLocalChecked().As<String>();
 }
 
+void Shell::NodeTypeCallback(const v8::FunctionCallbackInfo<v8::Value>& args) {
+  v8::Isolate* isolate = args.GetIsolate();
+  args.GetReturnValue().Set(v8::Number::New(isolate, 1));
+}
+
+Local<FunctionTemplate> Shell::CreateNodeTemplates(Isolate* isolate) {
+  Local<FunctionTemplate> node = FunctionTemplate::New(isolate);
+  Local<ObjectTemplate> proto_template = node->PrototypeTemplate();
+  Local<Signature> signature = v8::Signature::New(isolate, node);
+  Local<FunctionTemplate> nodeType = FunctionTemplate::New(
+      isolate, NodeTypeCallback, Local<Value>(), signature);
+  nodeType->SetAcceptAnyReceiver(false);
+  proto_template->SetAccessorProperty(
+      String::NewFromUtf8Literal(isolate, "nodeType"), nodeType);
+
+  Local<FunctionTemplate> element = FunctionTemplate::New(isolate);
+  element->Inherit(node);
+
+  Local<FunctionTemplate> html_element = FunctionTemplate::New(isolate);
+  html_element->Inherit(element);
+
+  Local<FunctionTemplate> div_element = FunctionTemplate::New(isolate);
+  div_element->Inherit(html_element);
+
+  return div_element;
+}
+
 Local<ObjectTemplate> Shell::CreateGlobalTemplate(Isolate* isolate) {
   Local<ObjectTemplate> global_template = ObjectTemplate::New(isolate);
   global_template->Set(Symbol::GetToStringTag(isolate),
@@ -2588,6 +2650,7 @@ Local<ObjectTemplate> Shell::CreateGlobalTemplate(Isolate* isolate) {
   global_template->Set(isolate, "performance",
                        Shell::CreatePerformanceTemplate(isolate));
   global_template->Set(isolate, "Worker", Shell::CreateWorkerTemplate(isolate));
+
   // Prevent fuzzers from creating side effects.
   if (!i::FLAG_fuzzing) {
     global_template->Set(isolate, "os", Shell::CreateOSTemplate(isolate));
@@ -2716,23 +2779,41 @@ Local<ObjectTemplate> Shell::CreateD8Template(Isolate* isolate) {
                       FunctionTemplate::New(isolate, LogGetAndStop));
 
     d8_template->Set(isolate, "log", log_template);
+
+    Local<ObjectTemplate> dom_template = ObjectTemplate::New(isolate);
+    dom_template->Set(isolate, "Div", Shell::CreateNodeTemplates(isolate));
+    d8_template->Set(isolate, "dom", dom_template);
   }
   {
     Local<ObjectTemplate> test_template = ObjectTemplate::New(isolate);
-    test_template->Set(
-        isolate, "verifySourcePositions",
-        FunctionTemplate::New(isolate, TestVerifySourcePositions));
+    // For different runs of correctness fuzzing the bytecode of a function
+    // might get flushed, resulting in spurious errors.
+    if (!i::FLAG_correctness_fuzzer_suppressions) {
+      test_template->Set(
+          isolate, "verifySourcePositions",
+          FunctionTemplate::New(isolate, TestVerifySourcePositions));
+    }
     // Correctness fuzzing will attempt to compare results of tests with and
     // without turbo_fast_api_calls, so we don't expose the fast_c_api
     // constructor when --correctness_fuzzer_suppressions is on.
     if (i::FLAG_turbo_fast_api_calls &&
         !i::FLAG_correctness_fuzzer_suppressions) {
-      test_template->Set(isolate, "fast_c_api",
+      test_template->Set(isolate, "FastCAPI",
                          Shell::CreateTestFastCApiTemplate(isolate));
+      test_template->Set(isolate, "LeafInterfaceType",
+                         Shell::CreateLeafInterfaceTypeTemplate(isolate));
     }
 
     d8_template->Set(isolate, "test", test_template);
   }
+  {
+    Local<ObjectTemplate> promise_template = ObjectTemplate::New(isolate);
+    promise_template->Set(
+        isolate, "setHooks",
+        FunctionTemplate::New(isolate, SetPromiseHooks, Local<Value>(),
+                              Local<Signature>(), 4));
+    d8_template->Set(isolate, "promise", promise_template);
+  }
   return d8_template;
 }
 
@@ -3187,13 +3268,13 @@ void Shell::ReadBuffer(const v8::FunctionCallbackInfo<v8::Value>& args) {
   String::Utf8Value filename(isolate, args[0]);
   int length;
   if (*filename == nullptr) {
-    Throw(isolate, "Error loading file");
+    isolate->ThrowError("Error loading file");
     return;
   }
 
   uint8_t* data = reinterpret_cast<uint8_t*>(ReadChars(*filename, &length));
   if (data == nullptr) {
-    Throw(isolate, "Error reading file");
+    isolate->ThrowError("Error reading file");
     return;
   }
   std::unique_ptr<v8::BackingStore> backing_store =
@@ -3860,7 +3941,7 @@ void Worker::PostMessageOut(const v8::FunctionCallbackInfo<v8::Value>& args) {
   HandleScope handle_scope(isolate);
 
   if (args.Length() < 1) {
-    Throw(isolate, "Invalid argument");
+    isolate->ThrowError("Invalid argument");
     return;
   }
 
@@ -3901,25 +3982,6 @@ bool Shell::SetOptions(int argc, char* argv[]) {
                strcmp(argv[i], "--no-stress-opt") == 0) {
       options.stress_opt = false;
       argv[i] = nullptr;
-    } else if (strcmp(argv[i], "--stress-snapshot") == 0) {
-      options.stress_snapshot = true;
-      // Incremental marking is incompatible with the stress_snapshot mode;
-      // specifically, serialization may clear bytecode arrays from shared
-      // function infos which the MarkCompactCollector (running concurrently)
-      // may still need. See also https://crbug.com/v8/10882.
-      //
-      // We thus force the implication
-      //
-      //   --stress-snapshot ~~> --no-incremental-marking
-      //
-      // Note: This is not an issue in production because we don't clear SFI's
-      // there (that only happens in mksnapshot and in --stress-snapshot mode).
-      i::FLAG_incremental_marking = false;
-      argv[i] = nullptr;
-    } else if (strcmp(argv[i], "--nostress-snapshot") == 0 ||
-               strcmp(argv[i], "--no-stress-snapshot") == 0) {
-      options.stress_snapshot = false;
-      argv[i] = nullptr;
     } else if (strcmp(argv[i], "--noalways-opt") == 0 ||
                strcmp(argv[i], "--no-always-opt") == 0) {
       no_always_opt = true;
@@ -4058,6 +4120,12 @@ bool Shell::SetOptions(int argc, char* argv[]) {
     } else if (strncmp(argv[i], "--web-snapshot-config=", 22) == 0) {
       options.web_snapshot_config = argv[i] + 22;
       argv[i] = nullptr;
+    } else if (strcmp(argv[i], "--compile-only") == 0) {
+      options.compile_only = true;
+      argv[i] = nullptr;
+    } else if (strncmp(argv[i], "--repeat-compile=", 17) == 0) {
+      options.repeat_compile = atoi(argv[i] + 17);
+      argv[i] = nullptr;
 #ifdef V8_FUZZILLI
     } else if (strcmp(argv[i], "--no-fuzzilli-enable-builtins-coverage") == 0) {
       options.fuzzilli_enable_builtins_coverage = false;
@@ -4069,11 +4137,15 @@ bool Shell::SetOptions(int argc, char* argv[]) {
     } else if (strcmp(argv[i], "--fuzzy-module-file-extensions") == 0) {
       options.fuzzy_module_file_extensions = true;
       argv[i] = nullptr;
-#if defined(V8_OS_WIN) && defined(V8_ENABLE_SYSTEM_INSTRUMENTATION)
+#if defined(V8_ENABLE_SYSTEM_INSTRUMENTATION)
     } else if (strcmp(argv[i], "--enable-system-instrumentation") == 0) {
       options.enable_system_instrumentation = true;
       options.trace_enabled = true;
+#if defined(V8_OS_WIN)
+      // Guard this bc the flag has a lot of overhead and is not currently used
+      // by macos
       i::FLAG_interpreted_frames_native_stack = true;
+#endif
       argv[i] = nullptr;
 #endif
     }
@@ -4164,7 +4236,7 @@ int Shell::RunMain(Isolate* isolate, bool last_run) {
       DisposeModuleEmbedderData(context);
     }
     WriteLcovData(isolate, options.lcov_file);
-    if (last_run && options.stress_snapshot) {
+    if (last_run && i::FLAG_stress_snapshot) {
       static constexpr bool kClearRecompilableData = true;
       i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
       i::Handle<i::Context> i_context = Utils::OpenHandle(*context);
@@ -4426,7 +4498,8 @@ class Serializer : public ValueSerializer::Delegate {
         Local<Value> element;
         if (transfer_array->Get(context, i).ToLocal(&element)) {
           if (!element->IsArrayBuffer()) {
-            Throw(isolate_, "Transfer array elements must be an ArrayBuffer");
+            isolate_->ThrowError(
+                "Transfer array elements must be an ArrayBuffer");
             return Nothing<bool>();
           }
 
@@ -4434,8 +4507,8 @@ class Serializer : public ValueSerializer::Delegate {
 
           if (std::find(array_buffers_.begin(), array_buffers_.end(),
                         array_buffer) != array_buffers_.end()) {
-            Throw(isolate_,
-                  "ArrayBuffer occurs in the transfer array more than once");
+            isolate_->ThrowError(
+                "ArrayBuffer occurs in the transfer array more than once");
             return Nothing<bool>();
           }
 
@@ -4450,7 +4523,7 @@ class Serializer : public ValueSerializer::Delegate {
     } else if (transfer->IsUndefined()) {
       return Just(true);
     } else {
-      Throw(isolate_, "Transfer list must be an Array or undefined");
+      isolate_->ThrowError("Transfer list must be an Array or undefined");
       return Nothing<bool>();
     }
   }
@@ -4460,7 +4533,7 @@ class Serializer : public ValueSerializer::Delegate {
       Local<ArrayBuffer> array_buffer =
           Local<ArrayBuffer>::New(isolate_, global_array_buffer);
       if (!array_buffer->IsDetachable()) {
-        Throw(isolate_, "ArrayBuffer could not be transferred");
+        isolate_->ThrowError("ArrayBuffer could not be transferred");
         return Nothing<bool>();
       }
 
diff --git a/chromium/v8/src/d8/d8.h b/chromium/v8/src/d8/d8.h
index d5f13817d35..75c80461156 100644
--- a/chromium/v8/src/d8/d8.h
+++ b/chromium/v8/src/d8/d8.h
@@ -271,6 +271,9 @@ class PerIsolateData {
   void AddDynamicImportData(DynamicImportData*);
   void DeleteDynamicImportData(DynamicImportData*);
 
+  Local<FunctionTemplate> GetTestApiObjectCtor() const;
+  void SetTestApiObjectCtor(Local<FunctionTemplate> ctor);
+
  private:
   friend class Shell;
   friend class RealmScope;
@@ -289,6 +292,7 @@ class PerIsolateData {
 #if defined(LEAK_SANITIZER)
   std::unordered_set<DynamicImportData*> import_data_;
 #endif
+  Global<FunctionTemplate> test_api_object_ctor_;
 
   int RealmIndexOrThrow(const v8::FunctionCallbackInfo<v8::Value>& args,
                         int arg_offset);
@@ -358,7 +362,6 @@ class ShellOptions {
   DisallowReassignment<bool> simulate_errors = {"simulate-errors", false};
   DisallowReassignment<bool> stress_opt = {"stress-opt", false};
   DisallowReassignment<int> stress_runs = {"stress-runs", 1};
-  DisallowReassignment<bool> stress_snapshot = {"stress-snapshot", false};
   DisallowReassignment<bool> interactive_shell = {"shell", false};
   bool test_shell = false;
   DisallowReassignment<bool> expected_to_throw = {"throws", false};
@@ -403,6 +406,8 @@ class ShellOptions {
       "enable-system-instrumentation", false};
   DisallowReassignment<const char*> web_snapshot_config = {
       "web-snapshot-config", nullptr};
+  DisallowReassignment<bool> compile_only = {"compile-only", false};
+  DisallowReassignment<int> repeat_compile = {"repeat-compile", 1};
 };
 
 class Shell : public i::AllStatic {
@@ -483,6 +488,8 @@ class Shell : public i::AllStatic {
   static void AsyncHooksTriggerAsyncId(
       const v8::FunctionCallbackInfo<v8::Value>& args);
 
+  static void SetPromiseHooks(const v8::FunctionCallbackInfo<v8::Value>& args);
+
   static void Print(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void PrintErr(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void Write(const v8::FunctionCallbackInfo<v8::Value>& args);
@@ -624,6 +631,9 @@ class Shell : public i::AllStatic {
   static void RunShell(Isolate* isolate);
   static bool SetOptions(int argc, char* argv[]);
 
+  static void NodeTypeCallback(const v8::FunctionCallbackInfo<v8::Value>& args);
+
+  static Local<FunctionTemplate> CreateNodeTemplates(Isolate* isolate);
   static Local<ObjectTemplate> CreateGlobalTemplate(Isolate* isolate);
   static Local<ObjectTemplate> CreateOSTemplate(Isolate* isolate);
   static Local<FunctionTemplate> CreateWorkerTemplate(Isolate* isolate);
@@ -633,6 +643,8 @@ class Shell : public i::AllStatic {
   static Local<ObjectTemplate> CreateRealmTemplate(Isolate* isolate);
   static Local<ObjectTemplate> CreateD8Template(Isolate* isolate);
   static Local<FunctionTemplate> CreateTestFastCApiTemplate(Isolate* isolate);
+  static Local<FunctionTemplate> CreateLeafInterfaceTypeTemplate(
+      Isolate* isolate);
 
   static MaybeLocal<Context> CreateRealm(
       const v8::FunctionCallbackInfo<v8::Value>& args, int index,
diff --git a/chromium/v8/src/debug/arm/debug-arm.cc b/chromium/v8/src/debug/arm/debug-arm.cc
deleted file mode 100644
index 238bc5b85d4..00000000000
--- a/chromium/v8/src/debug/arm/debug-arm.cc
+++ /dev/null
@@ -1,57 +0,0 @@
-// Copyright 2012 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#if V8_TARGET_ARCH_ARM
-
-#include "src/debug/debug.h"
-
-#include "src/codegen/assembler-inl.h"
-#include "src/codegen/macro-assembler.h"
-#include "src/debug/liveedit.h"
-#include "src/execution/frames-inl.h"
-#include "src/objects/objects-inl.h"
-
-namespace v8 {
-namespace internal {
-
-#define __ ACCESS_MASM(masm)
-
-
-void DebugCodegen::GenerateHandleDebuggerStatement(MacroAssembler* masm) {
-  {
-    FrameScope scope(masm, StackFrame::INTERNAL);
-    __ CallRuntime(Runtime::kHandleDebuggerStatement, 0);
-  }
-  __ MaybeDropFrames();
-
-  // Return to caller.
-  __ Ret();
-}
-
-void DebugCodegen::GenerateFrameDropperTrampoline(MacroAssembler* masm) {
-  // Frame is being dropped:
-  // - Drop to the target frame specified by r1.
-  // - Look up current function on the frame.
-  // - Leave the frame.
-  // - Restart the frame by calling the function.
-  __ mov(fp, r1);
-  __ ldr(r1, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
-  __ ldr(r0, MemOperand(fp, StandardFrameConstants::kArgCOffset));
-  __ LeaveFrame(StackFrame::INTERNAL);
-
-  // The arguments are already in the stack (including any necessary padding),
-  // we should not try to massage the arguments again.
-  __ mov(r2, Operand(kDontAdaptArgumentsSentinel));
-  __ InvokeFunction(r1, r2, r0, JUMP_FUNCTION);
-}
-
-
-const bool LiveEdit::kFrameDropperSupported = true;
-
-#undef __
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_TARGET_ARCH_ARM
diff --git a/chromium/v8/src/debug/arm64/debug-arm64.cc b/chromium/v8/src/debug/arm64/debug-arm64.cc
deleted file mode 100644
index b12d235983c..00000000000
--- a/chromium/v8/src/debug/arm64/debug-arm64.cc
+++ /dev/null
@@ -1,58 +0,0 @@
-// Copyright 2013 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#if V8_TARGET_ARCH_ARM64
-
-#include "src/debug/debug.h"
-
-#include "src/codegen/arm64/macro-assembler-arm64-inl.h"
-#include "src/debug/liveedit.h"
-#include "src/execution/frame-constants.h"
-#include "src/execution/frames-inl.h"
-#include "src/objects/objects-inl.h"
-
-namespace v8 {
-namespace internal {
-
-#define __ ACCESS_MASM(masm)
-
-void DebugCodegen::GenerateHandleDebuggerStatement(MacroAssembler* masm) {
-  {
-    FrameScope scope(masm, StackFrame::INTERNAL);
-    __ CallRuntime(Runtime::kHandleDebuggerStatement, 0);
-  }
-  __ MaybeDropFrames();
-
-  // Return to caller.
-  __ Ret();
-}
-
-void DebugCodegen::GenerateFrameDropperTrampoline(MacroAssembler* masm) {
-  // Frame is being dropped:
-  // - Drop to the target frame specified by x1.
-  // - Look up current function on the frame.
-  // - Leave the frame.
-  // - Restart the frame by calling the function.
-  __ Mov(fp, x1);
-  __ Ldr(x1, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
-  __ ldr(x0, MemOperand(fp, StandardFrameConstants::kArgCOffset));
-
-  __ Mov(sp, fp);
-  __ Pop<TurboAssembler::kAuthLR>(fp, lr);
-
-  // The arguments are already in the stack (including any necessary padding),
-  // we should not try to massage the arguments again.
-  __ Mov(x3, kDontAdaptArgumentsSentinel);
-  __ InvokeFunctionWithNewTarget(x1, x3, x0, JUMP_FUNCTION);
-}
-
-
-const bool LiveEdit::kFrameDropperSupported = true;
-
-}  // namespace internal
-}  // namespace v8
-
-#undef __
-
-#endif  // V8_TARGET_ARCH_ARM64
diff --git a/chromium/v8/src/debug/debug-coverage.cc b/chromium/v8/src/debug/debug-coverage.cc
index 56933602a65..7ff5809a18a 100644
--- a/chromium/v8/src/debug/debug-coverage.cc
+++ b/chromium/v8/src/debug/debug-coverage.cc
@@ -61,8 +61,7 @@ bool CompareCoverageBlock(const CoverageBlock& a, const CoverageBlock& b) {
   return a.start < b.start;
 }
 
-void SortBlockData(
-    std::vector<CoverageBlock>& v) {  // NOLINT(runtime/references)
+void SortBlockData(std::vector<CoverageBlock>& v) {
   // Sort according to the block nesting structure.
   std::sort(v.begin(), v.end(), CompareCoverageBlock);
 }
diff --git a/chromium/v8/src/debug/debug-evaluate.cc b/chromium/v8/src/debug/debug-evaluate.cc
index 4f317fcc89b..54fac88f59b 100644
--- a/chromium/v8/src/debug/debug-evaluate.cc
+++ b/chromium/v8/src/debug/debug-evaluate.cc
@@ -43,6 +43,22 @@ MaybeHandle<Object> DebugEvaluate::Global(Isolate* isolate,
                                           Handle<String> source,
                                           debug::EvaluateGlobalMode mode,
                                           REPLMode repl_mode) {
+  Handle<SharedFunctionInfo> shared_info;
+  if (!GetFunctionInfo(isolate, source, repl_mode).ToHandle(&shared_info)) {
+    return MaybeHandle<Object>();
+  }
+
+  Handle<NativeContext> context = isolate->native_context();
+  Handle<JSFunction> fun =
+      Factory::JSFunctionBuilder{isolate, shared_info, context}.Build();
+
+  return Global(isolate, fun, mode, repl_mode);
+}
+
+MaybeHandle<Object> DebugEvaluate::Global(Isolate* isolate,
+                                          Handle<JSFunction> function,
+                                          debug::EvaluateGlobalMode mode,
+                                          REPLMode repl_mode) {
   // Disable breaks in side-effect free mode.
   DisableBreak disable_break_scope(
       isolate->debug(),
@@ -50,19 +66,14 @@ MaybeHandle<Object> DebugEvaluate::Global(Isolate* isolate,
           mode ==
               debug::EvaluateGlobalMode::kDisableBreaksAndThrowOnSideEffect);
 
-  Handle<SharedFunctionInfo> shared_info;
-  if (!GetFunctionInfo(isolate, source, repl_mode).ToHandle(&shared_info)) {
-    return MaybeHandle<Object>();
-  }
+  Handle<NativeContext> context = isolate->native_context();
+  CHECK_EQ(function->native_context(), *context);
 
-  Handle<Context> context = isolate->native_context();
-  Handle<JSFunction> fun =
-      Factory::JSFunctionBuilder{isolate, shared_info, context}.Build();
   if (mode == debug::EvaluateGlobalMode::kDisableBreaksAndThrowOnSideEffect) {
     isolate->debug()->StartSideEffectCheckMode();
   }
   MaybeHandle<Object> result = Execution::Call(
-      isolate, fun, Handle<JSObject>(context->global_proxy(), isolate), 0,
+      isolate, function, Handle<JSObject>(context->global_proxy(), isolate), 0,
       nullptr);
   if (mode == debug::EvaluateGlobalMode::kDisableBreaksAndThrowOnSideEffect) {
     isolate->debug()->StopSideEffectCheckMode();
@@ -1108,7 +1119,7 @@ void DebugEvaluate::VerifyTransitiveBuiltins(Isolate* isolate) {
   }
   CHECK(!failed);
 #if defined(V8_TARGET_ARCH_PPC) || defined(V8_TARGET_ARCH_PPC64) || \
-    defined(V8_TARGET_ARCH_MIPS64) || defined(V8_TARGET_ARCH_RISCV64)
+    defined(V8_TARGET_ARCH_MIPS64)
   // Isolate-independent builtin calls and jumps do not emit reloc infos
   // on PPC. We try to avoid using PC relative code due to performance
   // issue with especially older hardwares.
diff --git a/chromium/v8/src/debug/debug-evaluate.h b/chromium/v8/src/debug/debug-evaluate.h
index 03836dd6dad..34a6c8d4c75 100644
--- a/chromium/v8/src/debug/debug-evaluate.h
+++ b/chromium/v8/src/debug/debug-evaluate.h
@@ -27,6 +27,10 @@ class DebugEvaluate : public AllStatic {
                                     debug::EvaluateGlobalMode mode,
                                     REPLMode repl_mode = REPLMode::kNo);
 
+  static V8_EXPORT_PRIVATE MaybeHandle<Object> Global(
+      Isolate* isolate, Handle<JSFunction> function,
+      debug::EvaluateGlobalMode mode, REPLMode repl_mode = REPLMode::kNo);
+
   // Evaluate a piece of JavaScript in the context of a stack frame for
   // debugging.  Things that need special attention are:
   // - Parameters and stack-allocated locals need to be materialized.  Altered
diff --git a/chromium/v8/src/debug/debug-frames.cc b/chromium/v8/src/debug/debug-frames.cc
index 2e5c9443cab..95b68014816 100644
--- a/chromium/v8/src/debug/debug-frames.cc
+++ b/chromium/v8/src/debug/debug-frames.cc
@@ -7,6 +7,10 @@
 #include "src/builtins/accessors.h"
 #include "src/execution/frames-inl.h"
 
+#if V8_ENABLE_WEBASSEMBLY
+#include "src/debug/debug-wasm-objects.h"
+#endif  // V8_ENABLE_WEBASSEMBLY
+
 namespace v8 {
 namespace internal {
 
@@ -21,7 +25,6 @@ FrameInspector::FrameInspector(CommonFrame* frame, int inlined_frame_index,
 
   is_constructor_ = summary.is_constructor();
   source_position_ = summary.SourcePosition();
-  function_name_ = summary.FunctionName();
   script_ = Handle<Script>::cast(summary.script());
   receiver_ = summary.receiver();
 
@@ -70,6 +73,18 @@ Handle<Object> FrameInspector::GetContext() {
                             : handle(frame_->context(), isolate_);
 }
 
+Handle<String> FrameInspector::GetFunctionName() {
+#if V8_ENABLE_WEBASSEMBLY
+  if (IsWasm()) {
+    auto wasm_frame = WasmFrame::cast(frame_);
+    auto wasm_instance = handle(wasm_frame->wasm_instance(), isolate_);
+    return GetWasmFunctionDebugName(isolate_, wasm_instance,
+                                    wasm_frame->function_index());
+  }
+#endif  // V8_ENABLE_WEBASSEMBLY
+  return JSFunction::GetDebugName(function_);
+}
+
 #if V8_ENABLE_WEBASSEMBLY
 bool FrameInspector::IsWasm() { return frame_->is_wasm(); }
 #endif  // V8_ENABLE_WEBASSEMBLY
diff --git a/chromium/v8/src/debug/debug-frames.h b/chromium/v8/src/debug/debug-frames.h
index 03f670e4995..5197f862988 100644
--- a/chromium/v8/src/debug/debug-frames.h
+++ b/chromium/v8/src/debug/debug-frames.h
@@ -36,7 +36,7 @@ class FrameInspector {
   Handle<Object> GetContext();
   Handle<Object> GetReceiver() { return receiver_; }
 
-  Handle<String> GetFunctionName() { return function_name_; }
+  Handle<String> GetFunctionName();
 
 #if V8_ENABLE_WEBASSEMBLY
   bool IsWasm();
@@ -58,7 +58,6 @@ class FrameInspector {
   Handle<Script> script_;
   Handle<Object> receiver_;
   Handle<JSFunction> function_;
-  Handle<String> function_name_;
   int source_position_ = -1;
   bool is_optimized_ = false;
   bool is_constructor_ = false;
diff --git a/chromium/v8/src/debug/debug-interface.cc b/chromium/v8/src/debug/debug-interface.cc
index bf74d379b6a..bc545a95d4c 100644
--- a/chromium/v8/src/debug/debug-interface.cc
+++ b/chromium/v8/src/debug/debug-interface.cc
@@ -12,7 +12,9 @@
 #include "src/debug/debug.h"
 #include "src/execution/vm-state-inl.h"
 #include "src/objects/js-generator-inl.h"
+#include "src/objects/stack-frame-info-inl.h"
 #include "src/regexp/regexp-stack.h"
+#include "src/strings/string-builder-inl.h"
 
 #if V8_ENABLE_WEBASSEMBLY
 #include "src/debug/debug-wasm-objects-inl.h"
@@ -43,6 +45,54 @@ v8_inspector::V8Inspector* GetInspector(Isolate* isolate) {
   return reinterpret_cast<i::Isolate*>(isolate)->inspector();
 }
 
+Local<String> GetFunctionDebugName(Local<StackFrame> frame) {
+#if V8_ENABLE_WEBASSEMBLY
+  auto info = Utils::OpenHandle(*frame);
+  if (info->IsWasm()) {
+    auto isolate = info->GetIsolate();
+    auto instance = handle(info->GetWasmInstance(), isolate);
+    auto func_index = info->GetWasmFunctionIndex();
+    return Utils::ToLocal(
+        i::GetWasmFunctionDebugName(isolate, instance, func_index));
+  }
+#endif  // V8_ENABLE_WEBASSEMBLY
+  return frame->GetFunctionName();
+}
+
+Local<String> GetFunctionDescription(Local<Function> function) {
+  auto receiver = Utils::OpenHandle(*function);
+  if (receiver->IsJSBoundFunction()) {
+    return Utils::ToLocal(i::JSBoundFunction::ToString(
+        i::Handle<i::JSBoundFunction>::cast(receiver)));
+  }
+  if (receiver->IsJSFunction()) {
+    auto function = i::Handle<i::JSFunction>::cast(receiver);
+#if V8_ENABLE_WEBASSEMBLY
+    if (function->shared().HasWasmExportedFunctionData()) {
+      auto isolate = function->GetIsolate();
+      auto func_index =
+          function->shared().wasm_exported_function_data().function_index();
+      auto instance = i::handle(
+          function->shared().wasm_exported_function_data().instance(), isolate);
+      if (instance->module()->origin == i::wasm::kWasmOrigin) {
+        // For asm.js functions, we can still print the source
+        // code (hopefully), so don't bother with them here.
+        auto debug_name =
+            i::GetWasmFunctionDebugName(isolate, instance, func_index);
+        i::IncrementalStringBuilder builder(isolate);
+        builder.AppendCString("function ");
+        builder.AppendString(debug_name);
+        builder.AppendCString("() { [native code] }");
+        return Utils::ToLocal(builder.Finish().ToHandleChecked());
+      }
+    }
+#endif  // V8_ENABLE_WEBASSEMBLY
+    return Utils::ToLocal(i::JSFunction::ToString(function));
+  }
+  return Utils::ToLocal(
+      receiver->GetIsolate()->factory()->function_native_code_string());
+}
+
 void SetBreakOnNextFunctionCall(Isolate* isolate) {
   reinterpret_cast<i::Isolate*>(isolate)->debug()->SetBreakOnNextFunctionCall();
 }
@@ -901,6 +951,21 @@ MaybeLocal<v8::Value> EvaluateGlobal(v8::Isolate* isolate,
   RETURN_ESCAPED(result);
 }
 
+v8::MaybeLocal<v8::Value> EvaluateGlobalForTesting(
+    v8::Isolate* isolate, v8::Local<v8::Script> function,
+    v8::debug::EvaluateGlobalMode mode, bool repl) {
+  i::Isolate* internal_isolate = reinterpret_cast<i::Isolate*>(isolate);
+  PREPARE_FOR_DEBUG_INTERFACE_EXECUTION_WITH_ISOLATE(internal_isolate, Value);
+  i::REPLMode repl_mode = repl ? i::REPLMode::kYes : i::REPLMode::kNo;
+  Local<Value> result;
+  has_pending_exception = !ToLocal<Value>(
+      i::DebugEvaluate::Global(internal_isolate, Utils::OpenHandle(*function),
+                               mode, repl_mode),
+      &result);
+  RETURN_ON_FAILED_EXECUTION(Value);
+  RETURN_ESCAPED(result);
+}
+
 void QueryObjects(v8::Local<v8::Context> v8_context,
                   QueryObjectPredicate* predicate,
                   PersistentValueVector<v8::Object>* objects) {
@@ -944,10 +1009,12 @@ int64_t GetNextRandomInt64(v8::Isolate* v8_isolate) {
 
 void EnumerateRuntimeCallCounters(v8::Isolate* v8_isolate,
                                   RuntimeCallCounterCallback callback) {
+#ifdef V8_RUNTIME_CALL_STATS
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
   if (isolate->counters()) {
     isolate->counters()->runtime_call_stats()->EnumerateCounters(callback);
   }
+#endif  // V8_RUNTIME_CALL_STATS
 }
 
 int GetDebuggingId(v8::Local<v8::Function> function) {
diff --git a/chromium/v8/src/debug/debug-interface.h b/chromium/v8/src/debug/debug-interface.h
index 66c7f3997e8..6c7ff9cbdde 100644
--- a/chromium/v8/src/debug/debug-interface.h
+++ b/chromium/v8/src/debug/debug-interface.h
@@ -7,7 +7,6 @@
 
 #include <memory>
 
-#include "include/v8-inspector.h"
 #include "include/v8-util.h"
 #include "include/v8.h"
 #include "src/base/platform/time.h"
@@ -15,6 +14,10 @@
 #include "src/debug/interface-types.h"
 #include "src/utils/vector.h"
 
+namespace v8_inspector {
+class V8Inspector;
+}  // namespace v8_inspector
+
 namespace v8 {
 
 namespace internal {
@@ -38,6 +41,16 @@ int GetContextId(Local<Context> context);
 void SetInspector(Isolate* isolate, v8_inspector::V8Inspector*);
 v8_inspector::V8Inspector* GetInspector(Isolate* isolate);
 
+// Returns the debug name for the function, which is supposed to be used
+// by the debugger and the developer tools. This can thus be different from
+// the name returned by the StackFrame::GetFunctionName() method. For example,
+// in case of WebAssembly, the debug name is WAT-compatible and thus always
+// preceeded by a dollar ('$').
+Local<String> GetFunctionDebugName(Local<StackFrame> frame);
+
+// Returns a debug string representation of the function.
+Local<String> GetFunctionDescription(Local<Function> function);
+
 // Schedule a debugger break to happen when function is called inside given
 // isolate.
 V8_EXPORT_PRIVATE void SetBreakOnNextFunctionCall(Isolate* isolate);
@@ -119,11 +132,7 @@ struct LiveEditResult {
     OK,
     COMPILE_ERROR,
     BLOCKED_BY_RUNNING_GENERATOR,
-    BLOCKED_BY_FUNCTION_ABOVE_BREAK_FRAME,
-    BLOCKED_BY_FUNCTION_BELOW_NON_DROPPABLE_FRAME,
-    BLOCKED_BY_ACTIVE_FUNCTION,
-    BLOCKED_BY_NEW_TARGET_IN_RESTART_FRAME,
-    FRAME_RESTART_IS_NOT_SUPPORTED
+    BLOCKED_BY_ACTIVE_FUNCTION
   };
   Status status = OK;
   bool stack_changed = false;
@@ -195,9 +204,8 @@ class WasmScript : public Script {
 };
 #endif  // V8_ENABLE_WEBASSEMBLY
 
-V8_EXPORT_PRIVATE void GetLoadedScripts(
-    Isolate* isolate,
-    PersistentValueVector<Script>& scripts);  // NOLINT(runtime/references)
+V8_EXPORT_PRIVATE void GetLoadedScripts(Isolate* isolate,
+                                        PersistentValueVector<Script>& scripts);
 
 MaybeLocal<UnboundScript> CompileInspectorScript(Isolate* isolate,
                                                  Local<String> source);
@@ -480,7 +488,6 @@ class V8_EXPORT_PRIVATE StackTraceIterator {
   virtual v8::Local<v8::Function> GetFunction() const = 0;
   virtual std::unique_ptr<ScopeIterator> GetScopeIterator() const = 0;
 
-  virtual bool Restart() = 0;
   virtual v8::MaybeLocal<v8::Value> Evaluate(v8::Local<v8::String> source,
                                              bool throw_on_side_effect) = 0;
 };
@@ -523,6 +530,10 @@ V8_EXPORT_PRIVATE v8::MaybeLocal<v8::Value> EvaluateGlobal(
     v8::Isolate* isolate, v8::Local<v8::String> source, EvaluateGlobalMode mode,
     bool repl_mode = false);
 
+V8_EXPORT_PRIVATE v8::MaybeLocal<v8::Value> EvaluateGlobalForTesting(
+    v8::Isolate* isolate, v8::Local<v8::Script> function,
+    v8::debug::EvaluateGlobalMode mode, bool repl);
+
 int GetDebuggingId(v8::Local<v8::Function> function);
 
 bool SetFunctionBreakpoint(v8::Local<v8::Function> function,
diff --git a/chromium/v8/src/debug/debug-scopes.cc b/chromium/v8/src/debug/debug-scopes.cc
index 03d49fac5ca..5f136d91d3d 100644
--- a/chromium/v8/src/debug/debug-scopes.cc
+++ b/chromium/v8/src/debug/debug-scopes.cc
@@ -192,7 +192,13 @@ class ScopeChainRetriever {
     // functions that have the same end position.
     const bool position_fits_end =
         closure_scope_ ? position_ < end : position_ <= end;
-    return start < position_ && position_fits_end;
+    // While we're evaluating a class, the calling function will have a class
+    // context on the stack with a range that starts at Token::CLASS, and the
+    // source position will also point to Token::CLASS.  To identify the
+    // matching scope we include start in the accepted range for class scopes.
+    const bool position_fits_start =
+        scope->is_class_scope() ? start <= position_ : start < position_;
+    return position_fits_start && position_fits_end;
   }
 };
 
diff --git a/chromium/v8/src/debug/debug-stack-trace-iterator.cc b/chromium/v8/src/debug/debug-stack-trace-iterator.cc
index 9904f781f92..93722d0f16c 100644
--- a/chromium/v8/src/debug/debug-stack-trace-iterator.cc
+++ b/chromium/v8/src/debug/debug-stack-trace-iterator.cc
@@ -172,14 +172,6 @@ DebugStackTraceIterator::GetScopeIterator() const {
   return std::make_unique<DebugScopeIterator>(isolate_, frame_inspector_.get());
 }
 
-bool DebugStackTraceIterator::Restart() {
-  DCHECK(!Done());
-#if V8_ENABLE_WEBASSEMBLY
-  if (iterator_.is_wasm()) return false;
-#endif  // V8_ENABLE_WEBASSEMBLY
-  return LiveEdit::RestartFrame(iterator_.javascript_frame());
-}
-
 v8::MaybeLocal<v8::Value> DebugStackTraceIterator::Evaluate(
     v8::Local<v8::String> source, bool throw_on_side_effect) {
   DCHECK(!Done());
diff --git a/chromium/v8/src/debug/debug-stack-trace-iterator.h b/chromium/v8/src/debug/debug-stack-trace-iterator.h
index 3319bc15f50..2d059e0ec5c 100644
--- a/chromium/v8/src/debug/debug-stack-trace-iterator.h
+++ b/chromium/v8/src/debug/debug-stack-trace-iterator.h
@@ -31,7 +31,6 @@ class DebugStackTraceIterator final : public debug::StackTraceIterator {
   v8::Local<v8::Function> GetFunction() const override;
   std::unique_ptr<v8::debug::ScopeIterator> GetScopeIterator() const override;
 
-  bool Restart() override;
   v8::MaybeLocal<v8::Value> Evaluate(v8::Local<v8::String> source,
                                      bool throw_on_side_effect) override;
 
diff --git a/chromium/v8/src/debug/debug-wasm-objects.cc b/chromium/v8/src/debug/debug-wasm-objects.cc
index 070221f433d..39286ed027e 100644
--- a/chromium/v8/src/debug/debug-wasm-objects.cc
+++ b/chromium/v8/src/debug/debug-wasm-objects.cc
@@ -323,15 +323,7 @@ struct FunctionsProxy : NamedDebugProxy<FunctionsProxy, kFunctionsProxy> {
   static Handle<String> GetName(Isolate* isolate,
                                 Handle<WasmInstanceObject> instance,
                                 uint32_t index) {
-    Handle<WasmModuleObject> module_object(instance->module_object(), isolate);
-    MaybeHandle<String> name =
-        WasmModuleObject::GetFunctionNameOrNull(isolate, module_object, index);
-    if (name.is_null()) {
-      name = GetNameFromImportsAndExportsOrNull(
-          isolate, instance, wasm::ImportExportKindCode::kExternalFunction,
-          index);
-    }
-    return GetNameOrDefault(isolate, name, "$func", index);
+    return GetWasmFunctionDebugName(isolate, instance, index);
   }
 };
 
@@ -1050,78 +1042,75 @@ std::unique_ptr<debug::ScopeIterator> GetWasmScopeIterator(WasmFrame* frame) {
   return std::make_unique<DebugWasmScopeIterator>(frame);
 }
 
-Handle<JSArray> GetWasmInstanceObjectInternalProperties(
-    Handle<WasmInstanceObject> instance) {
-  Isolate* isolate = instance->GetIsolate();
-  Handle<FixedArray> result = isolate->factory()->NewFixedArray(2 * 5);
-  int length = 0;
+Handle<String> GetWasmFunctionDebugName(Isolate* isolate,
+                                        Handle<WasmInstanceObject> instance,
+                                        uint32_t func_index) {
+  Handle<WasmModuleObject> module_object(instance->module_object(), isolate);
+  MaybeHandle<String> maybe_name = WasmModuleObject::GetFunctionNameOrNull(
+      isolate, module_object, func_index);
+  if (module_object->is_asm_js()) {
+    // In case of asm.js, we use the names from the function declarations.
+    return maybe_name.ToHandleChecked();
+  }
+  if (maybe_name.is_null()) {
+    maybe_name = GetNameFromImportsAndExportsOrNull(
+        isolate, instance, wasm::ImportExportKindCode::kExternalFunction,
+        func_index);
+  }
+  return GetNameOrDefault(isolate, maybe_name, "$func", func_index);
+}
 
-  Handle<String> module_str =
-      isolate->factory()->NewStringFromAsciiChecked("[[Module]]");
-  Handle<Object> module_obj = handle(instance->module_object(), isolate);
-  result->set(length++, *module_str);
-  result->set(length++, *module_obj);
+Handle<ArrayList> AddWasmInstanceObjectInternalProperties(
+    Isolate* isolate, Handle<ArrayList> result,
+    Handle<WasmInstanceObject> instance) {
+  result = ArrayList::Add(
+      isolate, result,
+      isolate->factory()->NewStringFromAsciiChecked("[[Module]]"),
+      handle(instance->module_object(), isolate));
 
   if (FunctionsProxy::Count(isolate, instance) != 0) {
-    Handle<String> functions_str =
-        isolate->factory()->NewStringFromAsciiChecked("[[Functions]]");
-    Handle<Object> functions_obj =
-        GetOrCreateInstanceProxy<FunctionsProxy>(isolate, instance);
-    result->set(length++, *functions_str);
-    result->set(length++, *functions_obj);
+    result = ArrayList::Add(
+        isolate, result,
+        isolate->factory()->NewStringFromAsciiChecked("[[Functions]]"),
+        GetOrCreateInstanceProxy<FunctionsProxy>(isolate, instance));
   }
 
   if (GlobalsProxy::Count(isolate, instance) != 0) {
-    Handle<String> globals_str =
-        isolate->factory()->NewStringFromAsciiChecked("[[Globals]]");
-    Handle<Object> globals_obj =
-        GetOrCreateInstanceProxy<GlobalsProxy>(isolate, instance);
-    result->set(length++, *globals_str);
-    result->set(length++, *globals_obj);
+    result = ArrayList::Add(
+        isolate, result,
+        isolate->factory()->NewStringFromAsciiChecked("[[Globals]]"),
+        GetOrCreateInstanceProxy<GlobalsProxy>(isolate, instance));
   }
 
   if (MemoriesProxy::Count(isolate, instance) != 0) {
-    Handle<String> memories_str =
-        isolate->factory()->NewStringFromAsciiChecked("[[Memories]]");
-    Handle<Object> memories_obj =
-        GetOrCreateInstanceProxy<MemoriesProxy>(isolate, instance);
-    result->set(length++, *memories_str);
-    result->set(length++, *memories_obj);
+    result = ArrayList::Add(
+        isolate, result,
+        isolate->factory()->NewStringFromAsciiChecked("[[Memories]]"),
+        GetOrCreateInstanceProxy<MemoriesProxy>(isolate, instance));
   }
 
   if (TablesProxy::Count(isolate, instance) != 0) {
-    Handle<String> tables_str =
-        isolate->factory()->NewStringFromAsciiChecked("[[Tables]]");
-    Handle<Object> tables_obj =
-        GetOrCreateInstanceProxy<TablesProxy>(isolate, instance);
-    result->set(length++, *tables_str);
-    result->set(length++, *tables_obj);
+    result = ArrayList::Add(
+        isolate, result,
+        isolate->factory()->NewStringFromAsciiChecked("[[Tables]]"),
+        GetOrCreateInstanceProxy<TablesProxy>(isolate, instance));
   }
 
-  return isolate->factory()->NewJSArrayWithElements(result, PACKED_ELEMENTS,
-                                                    length);
+  return result;
 }
 
-Handle<JSArray> GetWasmModuleObjectInternalProperties(
+Handle<ArrayList> AddWasmModuleObjectInternalProperties(
+    Isolate* isolate, Handle<ArrayList> result,
     Handle<WasmModuleObject> module_object) {
-  Isolate* isolate = module_object->GetIsolate();
-  Handle<FixedArray> result = isolate->factory()->NewFixedArray(2 * 2);
-  int length = 0;
-
-  Handle<String> exports_str =
-      isolate->factory()->NewStringFromStaticChars("[[Exports]]");
-  Handle<JSArray> exports_obj = wasm::GetExports(isolate, module_object);
-  result->set(length++, *exports_str);
-  result->set(length++, *exports_obj);
-
-  Handle<String> imports_str =
-      isolate->factory()->NewStringFromStaticChars("[[Imports]]");
-  Handle<JSArray> imports_obj = wasm::GetImports(isolate, module_object);
-  result->set(length++, *imports_str);
-  result->set(length++, *imports_obj);
-
-  return isolate->factory()->NewJSArrayWithElements(result, PACKED_ELEMENTS,
-                                                    length);
+  result = ArrayList::Add(
+      isolate, result,
+      isolate->factory()->NewStringFromStaticChars("[[Exports]]"),
+      wasm::GetExports(isolate, module_object));
+  result = ArrayList::Add(
+      isolate, result,
+      isolate->factory()->NewStringFromStaticChars("[[Imports]]"),
+      wasm::GetImports(isolate, module_object));
+  return result;
 }
 
 }  // namespace internal
diff --git a/chromium/v8/src/debug/debug-wasm-objects.h b/chromium/v8/src/debug/debug-wasm-objects.h
index 6eb075b9b6a..62e437b727c 100644
--- a/chromium/v8/src/debug/debug-wasm-objects.h
+++ b/chromium/v8/src/debug/debug-wasm-objects.h
@@ -28,6 +28,7 @@ class WasmValue;
 
 #include "torque-generated/src/debug/debug-wasm-objects-tq.inc"
 
+class ArrayList;
 class WasmFrame;
 class WasmInstanceObject;
 class WasmModuleObject;
@@ -68,9 +69,15 @@ Handle<JSObject> GetWasmDebugProxy(WasmFrame* frame);
 
 std::unique_ptr<debug::ScopeIterator> GetWasmScopeIterator(WasmFrame* frame);
 
-Handle<JSArray> GetWasmInstanceObjectInternalProperties(
+Handle<String> GetWasmFunctionDebugName(Isolate* isolate,
+                                        Handle<WasmInstanceObject> instance,
+                                        uint32_t func_index);
+
+Handle<ArrayList> AddWasmInstanceObjectInternalProperties(
+    Isolate* isolate, Handle<ArrayList> result,
     Handle<WasmInstanceObject> instance);
-Handle<JSArray> GetWasmModuleObjectInternalProperties(
+Handle<ArrayList> AddWasmModuleObjectInternalProperties(
+    Isolate* isolate, Handle<ArrayList> result,
     Handle<WasmModuleObject> module_object);
 
 }  // namespace internal
diff --git a/chromium/v8/src/debug/debug.cc b/chromium/v8/src/debug/debug.cc
index 0b873f7c8c3..42b800ef75d 100644
--- a/chromium/v8/src/debug/debug.cc
+++ b/chromium/v8/src/debug/debug.cc
@@ -352,7 +352,6 @@ void Debug::ThreadInit() {
   thread_local_.return_value_ = Smi::zero();
   thread_local_.last_breakpoint_id_ = 0;
   clear_suspended_generator();
-  thread_local_.restart_fp_ = kNullAddress;
   base::Relaxed_Store(&thread_local_.current_debug_scope_,
                       static_cast<base::AtomicWord>(0));
   thread_local_.break_on_next_function_call_ = false;
@@ -439,9 +438,6 @@ void Debug::Unload() {
 }
 
 void Debug::Break(JavaScriptFrame* frame, Handle<JSFunction> break_target) {
-  // Initialize LiveEdit.
-  LiveEdit::InitializeThreadLocal(this);
-
   // Just continue if breaks are disabled or debugger cannot be loaded.
   if (break_disabled()) return;
 
@@ -1245,7 +1241,7 @@ class DiscardBaselineCodeVisitor : public ThreadVisitor {
         BaselineFrame* frame = BaselineFrame::cast(it.frame());
         int bytecode_offset = frame->GetBytecodeOffset();
         Address* pc_addr = frame->pc_address();
-        Address advance = BUILTIN_CODE(isolate, InterpreterEnterBytecodeAdvance)
+        Address advance = BUILTIN_CODE(isolate, InterpreterEnterAtNextBytecode)
                               ->InstructionStart();
         PointerAuthentication::ReplacePC(pc_addr, advance, kSystemPointerSize);
         InterpretedFrame::cast(it.Reframe())
@@ -1264,8 +1260,8 @@ class DiscardBaselineCodeVisitor : public ThreadVisitor {
           Address* pc_addr = frame->pc_address();
           Builtins::Name advance =
               builtin_index == Builtins::kBaselineEnterAtBytecode
-                  ? Builtins::kInterpreterEnterBytecodeDispatch
-                  : Builtins::kInterpreterEnterBytecodeAdvance;
+                  ? Builtins::kInterpreterEnterAtBytecode
+                  : Builtins::kInterpreterEnterAtNextBytecode;
           Address advance_pc =
               isolate->builtins()->builtin(advance).InstructionStart();
           PointerAuthentication::ReplacePC(pc_addr, advance_pc,
@@ -1353,7 +1349,8 @@ void Debug::PrepareFunctionForDebugExecution(
   DCHECK(shared->is_compiled());
   DCHECK(shared->HasDebugInfo());
   Handle<DebugInfo> debug_info = GetOrCreateDebugInfo(shared);
-  if (debug_info->flags() & DebugInfo::kPreparedForDebugExecution) return;
+  if (debug_info->flags(kRelaxedLoad) & DebugInfo::kPreparedForDebugExecution)
+    return;
 
   if (shared->HasBytecodeArray()) {
     SharedFunctionInfo::InstallDebugBytecode(shared, isolate_);
@@ -1372,8 +1369,9 @@ void Debug::PrepareFunctionForDebugExecution(
     redirect_visitor.VisitThread(isolate_, isolate_->thread_local_top());
     isolate_->thread_manager()->IterateArchivedThreads(&redirect_visitor);
   }
-  debug_info->set_flags(debug_info->flags() |
-                        DebugInfo::kPreparedForDebugExecution);
+  debug_info->set_flags(
+      debug_info->flags(kRelaxedLoad) | DebugInfo::kPreparedForDebugExecution,
+      kRelaxedStore);
 }
 
 void Debug::InstallDebugBreakTrampoline() {
@@ -1630,7 +1628,9 @@ bool Debug::FindSharedFunctionInfosIntersectingRange(
     }
 
     if (!triedTopLevelCompile && !candidateSubsumesRange &&
-        script->shared_function_infos().length() > 0) {
+        script->shared_function_info_count() > 0) {
+      DCHECK_LE(script->shared_function_info_count(),
+                script->shared_function_infos().length());
       MaybeObject maybeToplevel = script->shared_function_infos().Get(0);
       HeapObject heap_object;
       const bool topLevelInfoExists =
@@ -1751,10 +1751,10 @@ void Debug::CreateBreakInfo(Handle<SharedFunctionInfo> shared) {
   Handle<FixedArray> break_points(
       factory->NewFixedArray(DebugInfo::kEstimatedNofBreakPointsInFunction));
 
-  int flags = debug_info->flags();
+  int flags = debug_info->flags(kRelaxedLoad);
   flags |= DebugInfo::kHasBreakInfo;
   if (CanBreakAtEntry(shared)) flags |= DebugInfo::kCanBreakAtEntry;
-  debug_info->set_flags(flags);
+  debug_info->set_flags(flags, kRelaxedStore);
   debug_info->set_break_points(*break_points);
 
   SharedFunctionInfo::EnsureSourcePositionsAvailable(isolate_, shared);
@@ -1781,7 +1781,9 @@ void Debug::InstallCoverageInfo(Handle<SharedFunctionInfo> shared,
 
   DCHECK(!debug_info->HasCoverageInfo());
 
-  debug_info->set_flags(debug_info->flags() | DebugInfo::kHasCoverageInfo);
+  debug_info->set_flags(
+      debug_info->flags(kRelaxedLoad) | DebugInfo::kHasCoverageInfo,
+      kRelaxedStore);
   debug_info->set_coverage_info(*coverage_info);
 }
 
@@ -1871,27 +1873,6 @@ bool Debug::IsBreakAtReturn(JavaScriptFrame* frame) {
   return location.IsReturn();
 }
 
-void Debug::ScheduleFrameRestart(StackFrame* frame) {
-  // Set a target FP for the FrameDropperTrampoline builtin to drop to once
-  // we return from the debugger.
-  DCHECK(frame->is_java_script());
-  // Only reschedule to a frame further below a frame we already scheduled for.
-  if (frame->fp() <= thread_local_.restart_fp_) return;
-  // If the frame is optimized, trigger a deopt and jump into the
-  // FrameDropperTrampoline in the deoptimizer.
-  thread_local_.restart_fp_ = frame->fp();
-
-  // Reset break frame ID to the frame below the restarted frame.
-  StackTraceFrameIterator it(isolate_);
-  thread_local_.break_frame_id_ = StackFrameId::NO_ID;
-  for (StackTraceFrameIterator it(isolate_); !it.done(); it.Advance()) {
-    if (it.frame()->fp() > thread_local_.restart_fp_) {
-      thread_local_.break_frame_id_ = it.frame()->id();
-      return;
-    }
-  }
-}
-
 Handle<FixedArray> Debug::GetLoadedScripts() {
   isolate_->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                       GarbageCollectionReason::kDebugger);
@@ -2243,8 +2224,6 @@ void Debug::UpdateHookOnFunctionCall() {
 }
 
 void Debug::HandleDebugBreak(IgnoreBreakMode ignore_break_mode) {
-  // Initialize LiveEdit.
-  LiveEdit::InitializeThreadLocal(this);
   // Ignore debug break during bootstrapping.
   if (isolate_->bootstrapper()->IsActive()) return;
   // Just continue if breaks are disabled.
@@ -2291,12 +2270,14 @@ void Debug::PrintBreakLocation() {
   StackTraceFrameIterator iterator(isolate_);
   if (iterator.done()) return;
   CommonFrame* frame = iterator.frame();
-  FrameSummary summary = FrameSummary::GetTop(frame);
-  summary.EnsureSourcePositionsAvailable();
-  int source_position = summary.SourcePosition();
-  Handle<Object> script_obj = summary.script();
+  std::vector<FrameSummary> frames;
+  frame->Summarize(&frames);
+  int inlined_frame_index = static_cast<int>(frames.size() - 1);
+  FrameInspector inspector(frame, inlined_frame_index, isolate_);
+  int source_position = inspector.GetSourcePosition();
+  Handle<Object> script_obj = inspector.GetScript();
   PrintF("[debug] break in function '");
-  summary.FunctionName()->PrintOn(stdout);
+  inspector.GetFunctionName()->PrintOn(stdout);
   PrintF("'.\n");
   if (script_obj->IsScript()) {
     Handle<Script> script = Handle<Script>::cast(script_obj);
diff --git a/chromium/v8/src/debug/debug.h b/chromium/v8/src/debug/debug.h
index 86c067c0357..28c6942c42f 100644
--- a/chromium/v8/src/debug/debug.h
+++ b/chromium/v8/src/debug/debug.h
@@ -311,9 +311,6 @@ class V8_EXPORT_PRIVATE Debug {
   // Check whether this frame is just about to return.
   bool IsBreakAtReturn(JavaScriptFrame* frame);
 
-  // Support for LiveEdit
-  void ScheduleFrameRestart(StackFrame* frame);
-
   bool AllFramesOnStackAreBlackboxed();
 
   // Set new script source, throw an exception if error occurred. When preview
@@ -380,13 +377,6 @@ class V8_EXPORT_PRIVATE Debug {
     return reinterpret_cast<Address>(&thread_local_.suspended_generator_);
   }
 
-  Address restart_fp_address() {
-    return reinterpret_cast<Address>(&thread_local_.restart_fp_);
-  }
-  bool will_restart() const {
-    return thread_local_.restart_fp_ != kNullAddress;
-  }
-
   StepAction last_step_action() { return thread_local_.last_step_action_; }
   bool break_on_next_function_call() const {
     return thread_local_.break_on_next_function_call_;
@@ -548,9 +538,6 @@ class V8_EXPORT_PRIVATE Debug {
     // The suspended generator object to track when stepping.
     Object suspended_generator_;
 
-    // The new frame pointer to drop to when restarting a frame.
-    Address restart_fp_;
-
     // Last used inspector breakpoint id.
     int last_breakpoint_id_;
 
@@ -669,25 +656,6 @@ class SuppressDebug {
   bool old_state_;
 };
 
-// Code generator routines.
-class DebugCodegen : public AllStatic {
- public:
-  enum DebugBreakCallHelperMode {
-    SAVE_RESULT_REGISTER,
-    IGNORE_RESULT_REGISTER
-  };
-
-  // Builtin to drop frames to restart function.
-  static void GenerateFrameDropperTrampoline(MacroAssembler* masm);
-
-  // Builtin to atomically (wrt deopts) handle debugger statement and
-  // drop frames to restart function if necessary.
-  static void GenerateHandleDebuggerStatement(MacroAssembler* masm);
-
-  // Builtin to trigger a debug break before entering the function.
-  static void GenerateDebugBreakTrampoline(MacroAssembler* masm);
-};
-
 }  // namespace internal
 }  // namespace v8
 
diff --git a/chromium/v8/src/debug/ia32/debug-ia32.cc b/chromium/v8/src/debug/ia32/debug-ia32.cc
deleted file mode 100644
index 72d4ac37df8..00000000000
--- a/chromium/v8/src/debug/ia32/debug-ia32.cc
+++ /dev/null
@@ -1,54 +0,0 @@
-// Copyright 2012 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#if V8_TARGET_ARCH_IA32
-
-#include "src/debug/debug.h"
-
-#include "src/codegen/macro-assembler.h"
-#include "src/debug/liveedit.h"
-#include "src/execution/frames-inl.h"
-
-namespace v8 {
-namespace internal {
-
-#define __ ACCESS_MASM(masm)
-
-void DebugCodegen::GenerateHandleDebuggerStatement(MacroAssembler* masm) {
-  {
-    FrameScope scope(masm, StackFrame::INTERNAL);
-    __ CallRuntime(Runtime::kHandleDebuggerStatement, 0);
-  }
-  __ MaybeDropFrames();
-
-  // Return to caller.
-  __ ret(0);
-}
-
-void DebugCodegen::GenerateFrameDropperTrampoline(MacroAssembler* masm) {
-  // Frame is being dropped:
-  // - Drop to the target frame specified by eax.
-  // - Look up current function on the frame.
-  // - Leave the frame.
-  // - Restart the frame by calling the function.
-  __ mov(ebp, eax);
-  __ mov(edi, Operand(ebp, StandardFrameConstants::kFunctionOffset));
-  __ mov(eax, Operand(ebp, StandardFrameConstants::kArgCOffset));
-  __ leave();
-
-  // The arguments are already in the stack (including any necessary padding),
-  // we should not try to massage the arguments again.
-  __ mov(ecx, Immediate(kDontAdaptArgumentsSentinel));
-  __ mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
-  __ InvokeFunctionCode(edi, no_reg, ecx, eax, JUMP_FUNCTION);
-}
-
-const bool LiveEdit::kFrameDropperSupported = true;
-
-#undef __
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_TARGET_ARCH_IA32
diff --git a/chromium/v8/src/debug/liveedit.cc b/chromium/v8/src/debug/liveedit.cc
index 294f0e1f7bb..a3065bb49fb 100644
--- a/chromium/v8/src/debug/liveedit.cc
+++ b/chromium/v8/src/debug/liveedit.cc
@@ -66,31 +66,35 @@ class Differencer {
  public:
   explicit Differencer(Comparator::Input* input)
       : input_(input), len1_(input->GetLength1()), len2_(input->GetLength2()) {
-    buffer_ = NewArray<int>(len1_ * len2_);
-  }
-  ~Differencer() {
-    DeleteArray(buffer_);
   }
 
   void Initialize() {
-    int array_size = len1_ * len2_;
-    for (int i = 0; i < array_size; i++) {
-      buffer_[i] = kEmptyCellValue;
-    }
   }
 
   // Makes sure that result for the full problem is calculated and stored
   // in the table together with flags showing a path through subproblems.
   void FillTable() {
-    CompareUpToTail(0, 0);
+    // Determine common prefix to skip.
+    int minLen = std::min(len1_, len2_);
+    while (prefixLen_ < minLen && input_->Equals(prefixLen_, prefixLen_)) {
+      ++prefixLen_;
+    }
+
+    // Pre-fill common suffix in the table.
+    for (int pos1 = len1_, pos2 = len2_; pos1 > prefixLen_ &&
+                                         pos2 > prefixLen_ &&
+                                         input_->Equals(--pos1, --pos2);) {
+      set_value4_and_dir(pos1, pos2, 0, EQ);
+    }
+
+    CompareUpToTail(prefixLen_, prefixLen_);
   }
 
   void SaveResult(Comparator::Output* chunk_writer) {
     ResultWriter writer(chunk_writer);
 
-    int pos1 = 0;
-    int pos2 = 0;
-    while (true) {
+    if (prefixLen_) writer.eq(prefixLen_);
+    for (int pos1 = prefixLen_, pos2 = prefixLen_; true;) {
       if (pos1 < len1_) {
         if (pos2 < len2_) {
           Direction dir = get_direction(pos1, pos2);
@@ -128,9 +132,10 @@ class Differencer {
 
  private:
   Comparator::Input* input_;
-  int* buffer_;
+  std::map<std::pair<int, int>, int> buffer_;
   int len1_;
   int len2_;
+  int prefixLen_ = 0;
 
   enum Direction {
     EQ = 0,
@@ -144,51 +149,51 @@ class Differencer {
   // Computes result for a subtask and optionally caches it in the buffer table.
   // All results values are shifted to make space for flags in the lower bits.
   int CompareUpToTail(int pos1, int pos2) {
-    if (pos1 < len1_) {
-      if (pos2 < len2_) {
-        int cached_res = get_value4(pos1, pos2);
-        if (cached_res == kEmptyCellValue) {
-          Direction dir;
-          int res;
-          if (input_->Equals(pos1, pos2)) {
-            res = CompareUpToTail(pos1 + 1, pos2 + 1);
-            dir = EQ;
-          } else {
-            int res1 = CompareUpToTail(pos1 + 1, pos2) +
-                (1 << kDirectionSizeBits);
-            int res2 = CompareUpToTail(pos1, pos2 + 1) +
-                (1 << kDirectionSizeBits);
-            if (res1 == res2) {
-              res = res1;
-              dir = SKIP_ANY;
-            } else if (res1 < res2) {
-              res = res1;
-              dir = SKIP1;
-            } else {
-              res = res2;
-              dir = SKIP2;
-            }
-          }
-          set_value4_and_dir(pos1, pos2, res, dir);
-          cached_res = res;
-        }
-        return cached_res;
+    if (pos1 == len1_) {
+      return (len2_ - pos2) << kDirectionSizeBits;
+    }
+    if (pos2 == len2_) {
+      return (len1_ - pos1) << kDirectionSizeBits;
+    }
+    int res = get_value4(pos1, pos2);
+    if (res != kEmptyCellValue) {
+      return res;
+    }
+    Direction dir;
+    if (input_->Equals(pos1, pos2)) {
+      res = CompareUpToTail(pos1 + 1, pos2 + 1);
+      dir = EQ;
+    } else {
+      int res1 = CompareUpToTail(pos1 + 1, pos2) + (1 << kDirectionSizeBits);
+      int res2 = CompareUpToTail(pos1, pos2 + 1) + (1 << kDirectionSizeBits);
+      if (res1 == res2) {
+        res = res1;
+        dir = SKIP_ANY;
+      } else if (res1 < res2) {
+        res = res1;
+        dir = SKIP1;
       } else {
-        return (len1_ - pos1) << kDirectionSizeBits;
+        res = res2;
+        dir = SKIP2;
       }
-    } else {
-      return (len2_ - pos2) << kDirectionSizeBits;
     }
+    set_value4_and_dir(pos1, pos2, res, dir);
+    return res;
   }
 
-  inline int& get_cell(int i1, int i2) {
-    return buffer_[i1 + i2 * len1_];
+  inline int get_cell(int i1, int i2) {
+    auto it = buffer_.find(std::make_pair(i1, i2));
+    return it == buffer_.end() ? kEmptyCellValue : it->second;
+  }
+
+  inline void set_cell(int i1, int i2, int value) {
+    buffer_.insert(std::make_pair(std::make_pair(i1, i2), value));
   }
 
   // Each cell keeps a value plus direction. Value is multiplied by 4.
   void set_value4_and_dir(int i1, int i2, int value4, Direction dir) {
     DCHECK_EQ(0, value4 & kDirectionMask);
-    get_cell(i1, i2) = value4 | dir;
+    set_cell(i1, i2, value4 | dir);
   }
 
   int get_value4(int i1, int i2) {
@@ -214,10 +219,10 @@ class Differencer {
         : chunk_writer_(chunk_writer), pos1_(0), pos2_(0),
           pos1_begin_(-1), pos2_begin_(-1), has_open_chunk_(false) {
     }
-    void eq() {
+    void eq(int len = 1) {
       FlushChunk();
-      pos1_++;
-      pos2_++;
+      pos1_ += len;
+      pos2_ += len;
     }
     void skip1(int len1) {
       StartChunk();
@@ -782,10 +787,8 @@ bool ParseScript(Isolate* isolate, Handle<Script> script, ParseInfo* parse_info,
 }
 
 struct FunctionData {
-  FunctionData(FunctionLiteral* literal, bool should_restart)
-      : literal(literal),
-        stack_position(NOT_ON_STACK),
-        should_restart(should_restart) {}
+  explicit FunctionData(FunctionLiteral* literal)
+      : literal(literal), stack_position(NOT_ON_STACK) {}
 
   FunctionLiteral* literal;
   MaybeHandle<SharedFunctionInfo> shared;
@@ -794,23 +797,14 @@ struct FunctionData {
   // In case of multiple functions with different stack position, the latest
   // one (in the order below) is used, since it is the most restrictive.
   // This is important only for functions to be restarted.
-  enum StackPosition {
-    NOT_ON_STACK,
-    ABOVE_BREAK_FRAME,
-    PATCHABLE,
-    BELOW_NON_DROPPABLE_FRAME,
-    ARCHIVED_THREAD,
-  };
+  enum StackPosition { NOT_ON_STACK, ON_STACK };
   StackPosition stack_position;
-  bool should_restart;
 };
 
 class FunctionDataMap : public ThreadVisitor {
  public:
-  void AddInterestingLiteral(int script_id, FunctionLiteral* literal,
-                             bool should_restart) {
-    map_.emplace(GetFuncId(script_id, literal),
-                 FunctionData{literal, should_restart});
+  void AddInterestingLiteral(int script_id, FunctionLiteral* literal) {
+    map_.emplace(GetFuncId(script_id, literal), FunctionData{literal});
   }
 
   bool Lookup(SharedFunctionInfo sfi, FunctionData** data) {
@@ -827,7 +821,7 @@ class FunctionDataMap : public ThreadVisitor {
     return Lookup(GetFuncId(script->id(), literal), data);
   }
 
-  void Fill(Isolate* isolate, Address* restart_frame_fp) {
+  void Fill(Isolate* isolate) {
     {
       HeapObjectIterator iterator(isolate->heap(),
                                   HeapObjectIterator::kFilterUnreachable);
@@ -854,38 +848,11 @@ class FunctionDataMap : public ThreadVisitor {
         }
       }
     }
-    FunctionData::StackPosition stack_position =
-        isolate->debug()->break_frame_id() == StackFrameId::NO_ID
-            ? FunctionData::PATCHABLE
-            : FunctionData::ABOVE_BREAK_FRAME;
-    for (StackFrameIterator it(isolate); !it.done(); it.Advance()) {
-      StackFrame* frame = it.frame();
-      if (stack_position == FunctionData::ABOVE_BREAK_FRAME) {
-        if (frame->id() == isolate->debug()->break_frame_id()) {
-          stack_position = FunctionData::PATCHABLE;
-        }
-      }
-      if (stack_position == FunctionData::PATCHABLE &&
-          (frame->is_exit() || frame->is_builtin_exit())) {
-        stack_position = FunctionData::BELOW_NON_DROPPABLE_FRAME;
-        continue;
-      }
-      if (!frame->is_java_script()) continue;
-      std::vector<Handle<SharedFunctionInfo>> sfis;
-      JavaScriptFrame::cast(frame)->GetFunctions(&sfis);
-      for (auto& sfi : sfis) {
-        if (stack_position == FunctionData::PATCHABLE &&
-            IsResumableFunction(sfi->kind())) {
-          stack_position = FunctionData::BELOW_NON_DROPPABLE_FRAME;
-        }
-        FunctionData* data = nullptr;
-        if (!Lookup(*sfi, &data)) continue;
-        if (!data->should_restart) continue;
-        data->stack_position = stack_position;
-        *restart_frame_fp = frame->fp();
-      }
-    }
 
+    // Visit the current thread stack.
+    VisitThread(isolate, isolate->thread_local_top());
+
+    // Visit the stacks of all archived threads.
     isolate->thread_manager()->IterateArchivedThreads(this);
   }
 
@@ -932,7 +899,7 @@ class FunctionDataMap : public ThreadVisitor {
       for (auto& sfi : sfis) {
         FunctionData* data = nullptr;
         if (!Lookup(*sfi, &data)) continue;
-        data->stack_position = FunctionData::ARCHIVED_THREAD;
+        data->stack_position = FunctionData::ON_STACK;
       }
     }
   }
@@ -940,11 +907,10 @@ class FunctionDataMap : public ThreadVisitor {
   std::map<FuncId, FunctionData> map_;
 };
 
-bool CanPatchScript(
-    const LiteralMap& changed, Handle<Script> script, Handle<Script> new_script,
-    FunctionDataMap& function_data_map,  // NOLINT(runtime/references)
-    debug::LiveEditResult* result) {
-  debug::LiveEditResult::Status status = debug::LiveEditResult::OK;
+bool CanPatchScript(const LiteralMap& changed, Handle<Script> script,
+                    Handle<Script> new_script,
+                    FunctionDataMap& function_data_map,
+                    debug::LiveEditResult* result) {
   for (const auto& mapping : changed) {
     FunctionData* data = nullptr;
     function_data_map.Lookup(script, mapping.first, &data);
@@ -953,55 +919,11 @@ bool CanPatchScript(
     Handle<SharedFunctionInfo> sfi;
     if (!data->shared.ToHandle(&sfi)) {
       continue;
-    } else if (!data->should_restart) {
-      UNREACHABLE();
-    } else if (data->stack_position == FunctionData::ABOVE_BREAK_FRAME) {
-      status = debug::LiveEditResult::BLOCKED_BY_FUNCTION_ABOVE_BREAK_FRAME;
-    } else if (data->stack_position ==
-               FunctionData::BELOW_NON_DROPPABLE_FRAME) {
-      status =
-          debug::LiveEditResult::BLOCKED_BY_FUNCTION_BELOW_NON_DROPPABLE_FRAME;
-    } else if (!data->running_generators.empty()) {
-      status = debug::LiveEditResult::BLOCKED_BY_RUNNING_GENERATOR;
-    } else if (data->stack_position == FunctionData::ARCHIVED_THREAD) {
-      status = debug::LiveEditResult::BLOCKED_BY_ACTIVE_FUNCTION;
-    }
-    if (status != debug::LiveEditResult::OK) {
-      result->status = status;
+    } else if (data->stack_position == FunctionData::ON_STACK) {
+      result->status = debug::LiveEditResult::BLOCKED_BY_ACTIVE_FUNCTION;
       return false;
-    }
-  }
-  return true;
-}
-
-bool CanRestartFrame(
-    Isolate* isolate, Address fp,
-    FunctionDataMap& function_data_map,  // NOLINT(runtime/references)
-    const LiteralMap& changed, debug::LiveEditResult* result) {
-  DCHECK_GT(fp, 0);
-  StackFrame* restart_frame = nullptr;
-  StackFrameIterator it(isolate);
-  for (; !it.done(); it.Advance()) {
-    if (it.frame()->fp() == fp) {
-      restart_frame = it.frame();
-      break;
-    }
-  }
-  DCHECK(restart_frame && restart_frame->is_java_script());
-  if (!LiveEdit::kFrameDropperSupported) {
-    result->status = debug::LiveEditResult::FRAME_RESTART_IS_NOT_SUPPORTED;
-    return false;
-  }
-  std::vector<Handle<SharedFunctionInfo>> sfis;
-  JavaScriptFrame::cast(restart_frame)->GetFunctions(&sfis);
-  for (auto& sfi : sfis) {
-    FunctionData* data = nullptr;
-    if (!function_data_map.Lookup(*sfi, &data)) continue;
-    auto new_literal_it = changed.find(data->literal);
-    if (new_literal_it == changed.end()) continue;
-    if (new_literal_it->second->scope()->new_target_var()) {
-      result->status =
-          debug::LiveEditResult::BLOCKED_BY_NEW_TARGET_IN_RESTART_FRAME;
+    } else if (!data->running_generators.empty()) {
+      result->status = debug::LiveEditResult::BLOCKED_BY_RUNNING_GENERATOR;
       return false;
     }
   }
@@ -1092,24 +1014,17 @@ void LiveEdit::PatchScript(Isolate* isolate, Handle<Script> script,
 
   FunctionDataMap function_data_map;
   for (const auto& mapping : changed) {
-    function_data_map.AddInterestingLiteral(script->id(), mapping.first, true);
-    function_data_map.AddInterestingLiteral(new_script->id(), mapping.second,
-                                            false);
+    function_data_map.AddInterestingLiteral(script->id(), mapping.first);
+    function_data_map.AddInterestingLiteral(new_script->id(), mapping.second);
   }
   for (const auto& mapping : unchanged) {
-    function_data_map.AddInterestingLiteral(script->id(), mapping.first, false);
+    function_data_map.AddInterestingLiteral(script->id(), mapping.first);
   }
-  Address restart_frame_fp = 0;
-  function_data_map.Fill(isolate, &restart_frame_fp);
+  function_data_map.Fill(isolate);
 
   if (!CanPatchScript(changed, script, new_script, function_data_map, result)) {
     return;
   }
-  if (restart_frame_fp &&
-      !CanRestartFrame(isolate, restart_frame_fp, function_data_map, changed,
-                       result)) {
-    return;
-  }
 
   if (preview) {
     result->status = debug::LiveEditResult::OK;
@@ -1273,16 +1188,6 @@ void LiveEdit::PatchScript(Isolate* isolate, Handle<Script> script,
   }
 #endif
 
-  if (restart_frame_fp) {
-    for (StackFrameIterator it(isolate); !it.done(); it.Advance()) {
-      if (it.frame()->fp() == restart_frame_fp) {
-        isolate->debug()->ScheduleFrameRestart(it.frame());
-        result->stack_changed = true;
-        break;
-      }
-    }
-  }
-
   int script_id = script->id();
   script->set_id(new_script->id());
   new_script->set_id(script_id);
@@ -1290,42 +1195,6 @@ void LiveEdit::PatchScript(Isolate* isolate, Handle<Script> script,
   result->script = ToApiHandle<v8::debug::Script>(new_script);
 }
 
-void LiveEdit::InitializeThreadLocal(Debug* debug) {
-  debug->thread_local_.restart_fp_ = 0;
-}
-
-bool LiveEdit::RestartFrame(JavaScriptFrame* frame) {
-  if (!LiveEdit::kFrameDropperSupported) return false;
-  Isolate* isolate = frame->isolate();
-  StackFrameId break_frame_id = isolate->debug()->break_frame_id();
-  bool break_frame_found = break_frame_id == StackFrameId::NO_ID;
-  for (StackFrameIterator it(isolate); !it.done(); it.Advance()) {
-    StackFrame* current = it.frame();
-    break_frame_found = break_frame_found || break_frame_id == current->id();
-    if (current->fp() == frame->fp()) {
-      if (break_frame_found) {
-        isolate->debug()->ScheduleFrameRestart(current);
-        return true;
-      } else {
-        return false;
-      }
-    }
-    if (!break_frame_found) continue;
-    if (current->is_exit() || current->is_builtin_exit()) {
-      return false;
-    }
-    if (!current->is_java_script()) continue;
-    std::vector<Handle<SharedFunctionInfo>> shareds;
-    JavaScriptFrame::cast(current)->GetFunctions(&shareds);
-    for (auto& shared : shareds) {
-      if (IsResumableFunction(shared->kind())) {
-        return false;
-      }
-    }
-  }
-  return false;
-}
-
 void LiveEdit::CompareStrings(Isolate* isolate, Handle<String> s1,
                               Handle<String> s2,
                               std::vector<SourceChangeRange>* diffs) {
diff --git a/chromium/v8/src/debug/liveedit.h b/chromium/v8/src/debug/liveedit.h
index 4291efb2d0e..5e06d3f2a3f 100644
--- a/chromium/v8/src/debug/liveedit.h
+++ b/chromium/v8/src/debug/liveedit.h
@@ -56,11 +56,6 @@ struct SourceChangeRange {
 
 class V8_EXPORT_PRIVATE LiveEdit : AllStatic {
  public:
-  static void InitializeThreadLocal(Debug* debug);
-
-  // Restarts the call frame and completely drops all frames above it.
-  static bool RestartFrame(JavaScriptFrame* frame);
-
   static void CompareStrings(Isolate* isolate, Handle<String> a,
                              Handle<String> b,
                              std::vector<SourceChangeRange>* diffs);
@@ -69,8 +64,6 @@ class V8_EXPORT_PRIVATE LiveEdit : AllStatic {
   static void PatchScript(Isolate* isolate, Handle<Script> script,
                           Handle<String> source, bool preview,
                           debug::LiveEditResult* result);
-  // Architecture-specific constant.
-  static const bool kFrameDropperSupported;
 };
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/debug/mips/debug-mips.cc b/chromium/v8/src/debug/mips/debug-mips.cc
deleted file mode 100644
index d1ab6ec545f..00000000000
--- a/chromium/v8/src/debug/mips/debug-mips.cc
+++ /dev/null
@@ -1,55 +0,0 @@
-// Copyright 2012 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#if V8_TARGET_ARCH_MIPS
-
-#include "src/debug/debug.h"
-
-#include "src/codegen/macro-assembler.h"
-#include "src/debug/liveedit.h"
-#include "src/execution/frames-inl.h"
-
-namespace v8 {
-namespace internal {
-
-#define __ ACCESS_MASM(masm)
-
-void DebugCodegen::GenerateHandleDebuggerStatement(MacroAssembler* masm) {
-  {
-    FrameScope scope(masm, StackFrame::INTERNAL);
-    __ CallRuntime(Runtime::kHandleDebuggerStatement, 0);
-  }
-  __ MaybeDropFrames();
-
-  // Return to caller.
-  __ Ret();
-}
-
-void DebugCodegen::GenerateFrameDropperTrampoline(MacroAssembler* masm) {
-  // Frame is being dropped:
-  // - Drop to the target frame specified by a1.
-  // - Look up current function on the frame.
-  // - Leave the frame.
-  // - Restart the frame by calling the function.
-  __ mov(fp, a1);
-  __ lw(a1, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
-  __ lw(a0, MemOperand(fp, StandardFrameConstants::kArgCOffset));
-
-  // Pop return address and frame.
-  __ LeaveFrame(StackFrame::INTERNAL);
-
-  __ li(a2, Operand(kDontAdaptArgumentsSentinel));
-
-  __ InvokeFunction(a1, a2, a0, JUMP_FUNCTION);
-}
-
-
-const bool LiveEdit::kFrameDropperSupported = true;
-
-#undef __
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_TARGET_ARCH_MIPS
diff --git a/chromium/v8/src/debug/mips64/debug-mips64.cc b/chromium/v8/src/debug/mips64/debug-mips64.cc
deleted file mode 100644
index 7b8e9e97447..00000000000
--- a/chromium/v8/src/debug/mips64/debug-mips64.cc
+++ /dev/null
@@ -1,55 +0,0 @@
-// Copyright 2012 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#if V8_TARGET_ARCH_MIPS64
-
-#include "src/debug/debug.h"
-
-#include "src/codegen/macro-assembler.h"
-#include "src/debug/liveedit.h"
-#include "src/execution/frames-inl.h"
-
-namespace v8 {
-namespace internal {
-
-#define __ ACCESS_MASM(masm)
-
-void DebugCodegen::GenerateHandleDebuggerStatement(MacroAssembler* masm) {
-  {
-    FrameScope scope(masm, StackFrame::INTERNAL);
-    __ CallRuntime(Runtime::kHandleDebuggerStatement, 0);
-  }
-  __ MaybeDropFrames();
-
-  // Return to caller.
-  __ Ret();
-}
-
-void DebugCodegen::GenerateFrameDropperTrampoline(MacroAssembler* masm) {
-  // Frame is being dropped:
-  // - Drop to the target frame specified by a1.
-  // - Look up current function on the frame.
-  // - Leave the frame.
-  // - Restart the frame by calling the function.
-  __ mov(fp, a1);
-  __ Ld(a1, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
-  __ Ld(a0, MemOperand(fp, StandardFrameConstants::kArgCOffset));
-
-  // Pop return address and frame.
-  __ LeaveFrame(StackFrame::INTERNAL);
-
-  __ li(a2, Operand(kDontAdaptArgumentsSentinel));
-
-  __ InvokeFunction(a1, a2, a0, JUMP_FUNCTION);
-}
-
-
-const bool LiveEdit::kFrameDropperSupported = true;
-
-#undef __
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_TARGET_ARCH_MIPS64
diff --git a/chromium/v8/src/debug/ppc/OWNERS b/chromium/v8/src/debug/ppc/OWNERS
deleted file mode 100644
index 02c2cd757c9..00000000000
--- a/chromium/v8/src/debug/ppc/OWNERS
+++ /dev/null
@@ -1,5 +0,0 @@
-junyan@redhat.com
-joransiu@ca.ibm.com
-midawson@redhat.com
-mfarazma@redhat.com
-vasili.skurydzin@ibm.com
diff --git a/chromium/v8/src/debug/ppc/debug-ppc.cc b/chromium/v8/src/debug/ppc/debug-ppc.cc
deleted file mode 100644
index c083708d3a4..00000000000
--- a/chromium/v8/src/debug/ppc/debug-ppc.cc
+++ /dev/null
@@ -1,53 +0,0 @@
-// Copyright 2014 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#if V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
-
-#include "src/debug/debug.h"
-
-#include "src/codegen/macro-assembler.h"
-#include "src/debug/liveedit.h"
-#include "src/execution/frames-inl.h"
-
-namespace v8 {
-namespace internal {
-
-#define __ ACCESS_MASM(masm)
-
-void DebugCodegen::GenerateHandleDebuggerStatement(MacroAssembler* masm) {
-  {
-    FrameScope scope(masm, StackFrame::INTERNAL);
-    __ CallRuntime(Runtime::kHandleDebuggerStatement, 0);
-  }
-  __ MaybeDropFrames();
-
-  // Return to caller.
-  __ Ret();
-}
-
-void DebugCodegen::GenerateFrameDropperTrampoline(MacroAssembler* masm) {
-  // Frame is being dropped:
-  // - Drop to the target frame specified by r4.
-  // - Look up current function on the frame.
-  // - Leave the frame.
-  // - Restart the frame by calling the function.
-
-  __ mr(fp, r4);
-  __ LoadP(r4, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
-  __ LoadP(r3, MemOperand(fp, StandardFrameConstants::kArgCOffset));
-  __ LeaveFrame(StackFrame::INTERNAL);
-
-  // The arguments are already in the stack (including any necessary padding),
-  // we should not try to massage the arguments again.
-  __ mov(r5, Operand(kDontAdaptArgumentsSentinel));
-  __ InvokeFunction(r4, r5, r3, JUMP_FUNCTION);
-}
-
-const bool LiveEdit::kFrameDropperSupported = true;
-
-#undef __
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
diff --git a/chromium/v8/src/debug/riscv64/debug-riscv64.cc b/chromium/v8/src/debug/riscv64/debug-riscv64.cc
deleted file mode 100644
index b2923001509..00000000000
--- a/chromium/v8/src/debug/riscv64/debug-riscv64.cc
+++ /dev/null
@@ -1,55 +0,0 @@
-// Copyright 2021 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#if V8_TARGET_ARCH_RISCV64
-
-#include "src/codegen/macro-assembler.h"
-#include "src/debug/debug.h"
-#include "src/debug/liveedit.h"
-#include "src/execution/frames-inl.h"
-
-namespace v8 {
-namespace internal {
-
-#define __ ACCESS_MASM(masm)
-
-void DebugCodegen::GenerateHandleDebuggerStatement(MacroAssembler* masm) {
-  {
-    FrameScope scope(masm, StackFrame::INTERNAL);
-    __ CallRuntime(Runtime::kHandleDebuggerStatement, 0);
-  }
-  __ MaybeDropFrames();
-
-  // Return to caller.
-  __ Ret();
-}
-
-void DebugCodegen::GenerateFrameDropperTrampoline(MacroAssembler* masm) {
-  // Frame is being dropped:
-  // - Drop to the target frame specified by a1.
-  // - Look up current function on the frame.
-  // - Leave the frame.
-  // - Restart the frame by calling the function.
-  __ mv(fp, a1);
-  __ Ld(a1, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
-
-  // Pop return address and frame.
-  __ LeaveFrame(StackFrame::INTERNAL);
-
-  __ Ld(a0, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
-  __ Lhu(a0,
-         FieldMemOperand(a0, SharedFunctionInfo::kFormalParameterCountOffset));
-  __ mv(a2, a0);
-
-  __ InvokeFunction(a1, a2, a0, JUMP_FUNCTION);
-}
-
-const bool LiveEdit::kFrameDropperSupported = true;
-
-#undef __
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_TARGET_ARCH_RISCV64
diff --git a/chromium/v8/src/debug/s390/debug-s390.cc b/chromium/v8/src/debug/s390/debug-s390.cc
deleted file mode 100644
index b58e70b8511..00000000000
--- a/chromium/v8/src/debug/s390/debug-s390.cc
+++ /dev/null
@@ -1,55 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "src/init/v8.h"
-
-#if V8_TARGET_ARCH_S390
-
-#include "src/debug/debug.h"
-
-#include "src/codegen/macro-assembler.h"
-#include "src/debug/liveedit.h"
-#include "src/execution/frames-inl.h"
-
-namespace v8 {
-namespace internal {
-
-#define __ ACCESS_MASM(masm)
-
-void DebugCodegen::GenerateHandleDebuggerStatement(MacroAssembler* masm) {
-  {
-    FrameScope scope(masm, StackFrame::INTERNAL);
-    __ CallRuntime(Runtime::kHandleDebuggerStatement, 0);
-  }
-  __ MaybeDropFrames();
-
-  // Return to caller.
-  __ Ret();
-}
-
-void DebugCodegen::GenerateFrameDropperTrampoline(MacroAssembler* masm) {
-  // Frame is being dropped:
-  // - Drop to the target frame specified by r3.
-  // - Look up current function on the frame.
-  // - Leave the frame.
-  // - Restart the frame by calling the function.
-
-  __ mov(fp, r3);
-  __ LoadU64(r3, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
-  __ LoadU64(r2, MemOperand(fp, StandardFrameConstants::kArgCOffset));
-  __ LeaveFrame(StackFrame::INTERNAL);
-
-  // The arguments are already in the stack (including any necessary padding),
-  // we should not try to massage the arguments again.
-  __ mov(r4, Operand(kDontAdaptArgumentsSentinel));
-  __ InvokeFunction(r3, r4, r2, JUMP_FUNCTION);
-}
-
-const bool LiveEdit::kFrameDropperSupported = true;
-
-#undef __
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_TARGET_ARCH_S390
diff --git a/chromium/v8/src/debug/x64/debug-x64.cc b/chromium/v8/src/debug/x64/debug-x64.cc
deleted file mode 100644
index 22092138318..00000000000
--- a/chromium/v8/src/debug/x64/debug-x64.cc
+++ /dev/null
@@ -1,55 +0,0 @@
-// Copyright 2012 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#if V8_TARGET_ARCH_X64
-
-#include "src/debug/debug.h"
-
-#include "src/codegen/assembler.h"
-#include "src/codegen/macro-assembler.h"
-#include "src/debug/liveedit.h"
-#include "src/execution/frames-inl.h"
-#include "src/objects/objects-inl.h"
-
-namespace v8 {
-namespace internal {
-
-#define __ ACCESS_MASM(masm)
-
-void DebugCodegen::GenerateHandleDebuggerStatement(MacroAssembler* masm) {
-  {
-    FrameScope scope(masm, StackFrame::INTERNAL);
-    __ CallRuntime(Runtime::kHandleDebuggerStatement, 0);
-  }
-  __ MaybeDropFrames();
-
-  // Return to caller.
-  __ ret(0);
-}
-
-void DebugCodegen::GenerateFrameDropperTrampoline(MacroAssembler* masm) {
-  // Frame is being dropped:
-  // - Drop to the target frame specified by rbx.
-  // - Look up current function on the frame.
-  // - Leave the frame.
-  // - Restart the frame by calling the function.
-  __ movq(rbp, rbx);
-  __ movq(rdi, Operand(rbp, StandardFrameConstants::kFunctionOffset));
-  __ movq(rax, Operand(rbp, StandardFrameConstants::kArgCOffset));
-  __ leave();
-
-  // The arguments are already in the stack (including any necessary padding),
-  // we should not try to massage the arguments again.
-  __ movq(rbx, Immediate(kDontAdaptArgumentsSentinel));
-  __ InvokeFunction(rdi, no_reg, rbx, rax, JUMP_FUNCTION);
-}
-
-const bool LiveEdit::kFrameDropperSupported = true;
-
-#undef __
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_TARGET_ARCH_X64
diff --git a/chromium/v8/src/deoptimizer/deoptimizer-cfi-builtins.cc b/chromium/v8/src/deoptimizer/deoptimizer-cfi-builtins.cc
index 0b7472dbea6..bbeacc561dc 100644
--- a/chromium/v8/src/deoptimizer/deoptimizer-cfi-builtins.cc
+++ b/chromium/v8/src/deoptimizer/deoptimizer-cfi-builtins.cc
@@ -6,8 +6,8 @@
 #include "src/deoptimizer/deoptimizer.h"
 
 extern "C" {
-void Builtins_InterpreterEnterBytecodeAdvance();
-void Builtins_InterpreterEnterBytecodeDispatch();
+void Builtins_InterpreterEnterAtBytecode();
+void Builtins_InterpreterEnterAtNextBytecode();
 void Builtins_ContinueToCodeStubBuiltinWithResult();
 void Builtins_ContinueToCodeStubBuiltin();
 void Builtins_ContinueToJavaScriptBuiltinWithResult();
@@ -24,8 +24,8 @@ namespace internal {
 
 // List of allowed builtin addresses that we can return to in the deoptimizer.
 constexpr function_ptr builtins[] = {
-    &Builtins_InterpreterEnterBytecodeAdvance,
-    &Builtins_InterpreterEnterBytecodeDispatch,
+    &Builtins_InterpreterEnterAtBytecode,
+    &Builtins_InterpreterEnterAtNextBytecode,
     &Builtins_ContinueToCodeStubBuiltinWithResult,
     &Builtins_ContinueToCodeStubBuiltin,
     &Builtins_ContinueToJavaScriptBuiltinWithResult,
diff --git a/chromium/v8/src/deoptimizer/deoptimizer.cc b/chromium/v8/src/deoptimizer/deoptimizer.cc
index 7c4562dbd56..eabd9ebb41c 100644
--- a/chromium/v8/src/deoptimizer/deoptimizer.cc
+++ b/chromium/v8/src/deoptimizer/deoptimizer.cc
@@ -380,8 +380,7 @@ void Deoptimizer::DeoptimizeMarkedCodeForContext(NativeContext native_context) {
 }
 
 void Deoptimizer::DeoptimizeAll(Isolate* isolate) {
-  RuntimeCallTimerScope runtimeTimer(isolate,
-                                     RuntimeCallCounterId::kDeoptimizeCode);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kDeoptimizeCode);
   TimerEventScope<TimerEventDeoptimizeCode> timer(isolate);
   TRACE_EVENT0("v8", "V8.DeoptimizeCode");
   TraceDeoptAll(isolate);
@@ -399,8 +398,7 @@ void Deoptimizer::DeoptimizeAll(Isolate* isolate) {
 }
 
 void Deoptimizer::DeoptimizeMarkedCode(Isolate* isolate) {
-  RuntimeCallTimerScope runtimeTimer(isolate,
-                                     RuntimeCallCounterId::kDeoptimizeCode);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kDeoptimizeCode);
   TimerEventScope<TimerEventDeoptimizeCode> timer(isolate);
   TRACE_EVENT0("v8", "V8.DeoptimizeCode");
   TraceDeoptMarked(isolate);
@@ -427,8 +425,7 @@ void Deoptimizer::MarkAllCodeForContext(NativeContext native_context) {
 
 void Deoptimizer::DeoptimizeFunction(JSFunction function, Code code) {
   Isolate* isolate = function.GetIsolate();
-  RuntimeCallTimerScope runtimeTimer(isolate,
-                                     RuntimeCallCounterId::kDeoptimizeCode);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kDeoptimizeCode);
   TimerEventScope<TimerEventDeoptimizeCode> timer(isolate);
   TRACE_EVENT0("v8", "V8.DeoptimizeCode");
   function.ResetIfBytecodeFlushed();
@@ -969,8 +966,8 @@ void Deoptimizer::DoComputeOutputFrames() {
   topmost->GetRegisterValues()->SetRegister(kRootRegister.code(),
                                             isolate()->isolate_root());
 #ifdef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
-  topmost->GetRegisterValues()->SetRegister(kPointerCageBaseRegister.code(),
-                                            isolate()->isolate_root());
+  topmost->GetRegisterValues()->SetRegister(kPtrComprCageBaseRegister.code(),
+                                            isolate()->cage_base());
 #endif
 
   // Print some helpful diagnostic information.
@@ -999,8 +996,8 @@ Builtins::Name DispatchBuiltinFor(bool is_baseline, bool advance_bc) {
     return advance_bc ? Builtins::kBaselineEnterAtNextBytecode
                       : Builtins::kBaselineEnterAtBytecode;
   } else {
-    return advance_bc ? Builtins::kInterpreterEnterBytecodeAdvance
-                      : Builtins::kInterpreterEnterBytecodeDispatch;
+    return advance_bc ? Builtins::kInterpreterEnterAtNextBytecode
+                      : Builtins::kInterpreterEnterAtBytecode;
   }
 }
 
diff --git a/chromium/v8/src/deoptimizer/riscv64/deoptimizer-riscv64.cc b/chromium/v8/src/deoptimizer/riscv64/deoptimizer-riscv64.cc
index 1cbe85ba5df..b7dceed503d 100644
--- a/chromium/v8/src/deoptimizer/riscv64/deoptimizer-riscv64.cc
+++ b/chromium/v8/src/deoptimizer/riscv64/deoptimizer-riscv64.cc
@@ -8,9 +8,9 @@ namespace v8 {
 namespace internal {
 
 const bool Deoptimizer::kSupportsFixedDeoptExitSizes = true;
-const int Deoptimizer::kNonLazyDeoptExitSize = 5 * kInstrSize;
-const int Deoptimizer::kLazyDeoptExitSize = 5 * kInstrSize;
-const int Deoptimizer::kEagerWithResumeBeforeArgsSize = 6 * kInstrSize;
+const int Deoptimizer::kNonLazyDeoptExitSize = 4 * kInstrSize;
+const int Deoptimizer::kLazyDeoptExitSize = 4 * kInstrSize;
+const int Deoptimizer::kEagerWithResumeBeforeArgsSize = 5 * kInstrSize;
 const int Deoptimizer::kEagerWithResumeDeoptExitSize =
     kEagerWithResumeBeforeArgsSize + 4 * kInstrSize;
 const int Deoptimizer::kEagerWithResumeImmedArgs1PcOffset = kInstrSize;
diff --git a/chromium/v8/src/deoptimizer/translated-state.cc b/chromium/v8/src/deoptimizer/translated-state.cc
index 02c473d22b1..abbc0104a8f 100644
--- a/chromium/v8/src/deoptimizer/translated-state.cc
+++ b/chromium/v8/src/deoptimizer/translated-state.cc
@@ -514,6 +514,12 @@ Handle<Object> TranslatedValue::GetValue() {
     //    pass the verifier.
     container_->EnsureObjectAllocatedAt(this);
 
+    // Finish any sweeping so that it becomes safe to overwrite the ByteArray
+    // headers.
+    // TODO(hpayer): Find a cleaner way to support a group of
+    // non-fully-initialized objects.
+    isolate()->heap()->mark_compact_collector()->EnsureSweepingCompleted();
+
     // 2. Initialize the objects. If we have allocated only byte arrays
     //    for some objects, we now overwrite the byte arrays with the
     //    correct object fields. Note that this phase does not allocate
@@ -1397,9 +1403,9 @@ TranslatedValue* TranslatedState::GetValueByObjectIndex(int object_index) {
 }
 
 Handle<HeapObject> TranslatedState::InitializeObjectAt(TranslatedValue* slot) {
-  slot = ResolveCapturedObject(slot);
-
   DisallowGarbageCollection no_gc;
+
+  slot = ResolveCapturedObject(slot);
   if (slot->materialization_state() != TranslatedValue::kFinished) {
     std::stack<int> worklist;
     worklist.push(slot->object_index());
@@ -1883,7 +1889,7 @@ void TranslatedState::InitializeJSObjectAt(
       WRITE_BARRIER(*object_storage, offset, *field_value);
     }
   }
-  object_storage->synchronized_set_map(*map);
+  object_storage->set_map(*map, kReleaseStore);
 }
 
 void TranslatedState::InitializeObjectWithTaggedFieldsAt(
@@ -1920,7 +1926,7 @@ void TranslatedState::InitializeObjectWithTaggedFieldsAt(
     WRITE_BARRIER(*object_storage, offset, *field_value);
   }
 
-  object_storage->synchronized_set_map(*map);
+  object_storage->set_map(*map, kReleaseStore);
 }
 
 TranslatedValue* TranslatedState::ResolveCapturedObject(TranslatedValue* slot) {
diff --git a/chromium/v8/src/diagnostics/compilation-statistics.cc b/chromium/v8/src/diagnostics/compilation-statistics.cc
index d7a67617e72..40bb239b125 100644
--- a/chromium/v8/src/diagnostics/compilation-statistics.cc
+++ b/chromium/v8/src/diagnostics/compilation-statistics.cc
@@ -2,11 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include <ostream>  // NOLINT(readability/streams)
+#include "src/diagnostics/compilation-statistics.h"
+
+#include <ostream>
 #include <vector>
 
 #include "src/base/platform/platform.h"
-#include "src/diagnostics/compilation-statistics.h"
 
 namespace v8 {
 namespace internal {
diff --git a/chromium/v8/src/diagnostics/disassembler.cc b/chromium/v8/src/diagnostics/disassembler.cc
index 6e6ecb3f034..91a7a72bbf5 100644
--- a/chromium/v8/src/diagnostics/disassembler.cc
+++ b/chromium/v8/src/diagnostics/disassembler.cc
@@ -237,10 +237,11 @@ static void PrintRelocInfo(StringBuilder* out, Isolate* isolate,
     out->AddFormatted("    ;; %sobject: %s",
                       is_compressed ? "(compressed) " : "", obj_name.get());
   } else if (rmode == RelocInfo::EXTERNAL_REFERENCE) {
+    Address address = relocinfo->target_external_reference();
     const char* reference_name =
-        ref_encoder ? ref_encoder->NameOfAddress(
-                          isolate, relocinfo->target_external_reference())
-                    : "unknown";
+        ref_encoder
+            ? ref_encoder->NameOfAddress(isolate, address)
+            : ExternalReferenceTable::NameOfIsolateIndependentAddress(address);
     out->AddFormatted("    ;; external reference (%s)", reference_name);
   } else if (RelocInfo::IsCodeTargetMode(rmode)) {
     out->AddFormatted("    ;; code:");
@@ -441,14 +442,16 @@ int Disassembler::Decode(Isolate* isolate, std::ostream* os, byte* begin,
                   "Builtins disassembly requires a readable .text section");
   V8NameConverter v8NameConverter(isolate, code);
   if (isolate) {
-    // We have an isolate, so support external reference names.
+    // We have an isolate, so support external reference names from V8 and
+    // embedder.
     SealHandleScope shs(isolate);
     DisallowGarbageCollection no_alloc;
     ExternalReferenceEncoder ref_encoder(isolate);
     return DecodeIt(isolate, &ref_encoder, os, code, v8NameConverter, begin,
                     end, current_pc);
   } else {
-    // No isolate => isolate-independent code. No external reference names.
+    // No isolate => isolate-independent code. Only V8 External references
+    // available.
     return DecodeIt(nullptr, nullptr, os, code, v8NameConverter, begin, end,
                     current_pc);
   }
diff --git a/chromium/v8/src/diagnostics/eh-frame.cc b/chromium/v8/src/diagnostics/eh-frame.cc
index ccafd23cb70..0c85ae3ca41 100644
--- a/chromium/v8/src/diagnostics/eh-frame.cc
+++ b/chromium/v8/src/diagnostics/eh-frame.cc
@@ -55,7 +55,7 @@ STATIC_CONST_MEMBER_DEFINITION const int EhFrameConstants::kEhFrameHdrSize;
 STATIC_CONST_MEMBER_DEFINITION const uint32_t EhFrameWriter::kInt32Placeholder;
 
 // static
-void EhFrameWriter::WriteEmptyEhFrame(std::ostream& stream) {  // NOLINT
+void EhFrameWriter::WriteEmptyEhFrame(std::ostream& stream) {
   stream.put(EhFrameConstants::kEhFrameHdrVersion);
 
   // .eh_frame pointer encoding specifier.
@@ -480,7 +480,7 @@ class V8_NODISCARD StreamModifiersScope final {
 }  // namespace
 
 // static
-void EhFrameDisassembler::DumpDwarfDirectives(std::ostream& stream,  // NOLINT
+void EhFrameDisassembler::DumpDwarfDirectives(std::ostream& stream,
                                               const byte* start,
                                               const byte* end) {
   StreamModifiersScope modifiers_scope(&stream);
@@ -592,7 +592,7 @@ void EhFrameDisassembler::DumpDwarfDirectives(std::ostream& stream,  // NOLINT
   }
 }
 
-void EhFrameDisassembler::DisassembleToStream(std::ostream& stream) {  // NOLINT
+void EhFrameDisassembler::DisassembleToStream(std::ostream& stream) {
   // The encoded CIE size does not include the size field itself.
   const int cie_size =
       base::ReadUnalignedValue<uint32_t>(reinterpret_cast<Address>(start_)) +
diff --git a/chromium/v8/src/diagnostics/eh-frame.h b/chromium/v8/src/diagnostics/eh-frame.h
index 9a22a97d58e..0d32085b0b0 100644
--- a/chromium/v8/src/diagnostics/eh-frame.h
+++ b/chromium/v8/src/diagnostics/eh-frame.h
@@ -80,7 +80,7 @@ class V8_EXPORT_PRIVATE EhFrameWriter {
   //
   // It is effectively a valid eh_frame_hdr with an empty look up table.
   //
-  static void WriteEmptyEhFrame(std::ostream& stream);  // NOLINT
+  static void WriteEmptyEhFrame(std::ostream& stream);
 
   // Write the CIE and FDE header. Call it before any other method.
   void Initialize();
@@ -293,11 +293,11 @@ class EhFrameDisassembler final {
   EhFrameDisassembler(const EhFrameDisassembler&) = delete;
   EhFrameDisassembler& operator=(const EhFrameDisassembler&) = delete;
 
-  void DisassembleToStream(std::ostream& stream);  // NOLINT
+  void DisassembleToStream(std::ostream& stream);
 
  private:
-  static void DumpDwarfDirectives(std::ostream& stream,  // NOLINT
-                                  const byte* start, const byte* end);
+  static void DumpDwarfDirectives(std::ostream& stream, const byte* start,
+                                  const byte* end);
 
   static const char* DwarfRegisterCodeToString(int code);
 
diff --git a/chromium/v8/src/diagnostics/ia32/disasm-ia32.cc b/chromium/v8/src/diagnostics/ia32/disasm-ia32.cc
index ae4cc02459a..687a214cab3 100644
--- a/chromium/v8/src/diagnostics/ia32/disasm-ia32.cc
+++ b/chromium/v8/src/diagnostics/ia32/disasm-ia32.cc
@@ -368,7 +368,7 @@ class DisassemblerIA32 {
         Disassembler::kAbortOnUnimplementedOpcode) {
       FATAL("Unimplemented instruction in disassembler");
     } else {
-      AppendToBuffer("'Unimplemented Instruction'");
+      AppendToBuffer("'Unimplemented instruction'");
     }
   }
 };
@@ -2076,6 +2076,7 @@ int DisassemblerIA32::InstructionDecode(v8::internal::Vector<char> out_buffer,
           data += 3;
         } else {
           UnimplementedInstruction();
+          data += 1;
         }
       } break;
 
@@ -2889,7 +2890,7 @@ int DisassemblerIA32::InstructionDecode(v8::internal::Vector<char> out_buffer,
 
   outp += v8::internal::SNPrintF(out_buffer + outp, " %s", tmp_buffer_.begin());
   return instr_len;
-}  // NOLINT (function is too long)
+}
 
 //------------------------------------------------------------------------------
 
diff --git a/chromium/v8/src/diagnostics/objects-debug.cc b/chromium/v8/src/diagnostics/objects-debug.cc
index b48df9385ae..6cfd8b3ad0c 100644
--- a/chromium/v8/src/diagnostics/objects-debug.cc
+++ b/chromium/v8/src/diagnostics/objects-debug.cc
@@ -61,6 +61,7 @@
 #include "src/objects/js-weak-refs-inl.h"
 #include "src/objects/literal-objects-inl.h"
 #include "src/objects/maybe-object.h"
+#include "src/objects/megadom-handler-inl.h"
 #include "src/objects/microtask-inl.h"
 #include "src/objects/module-inl.h"
 #include "src/objects/oddball-inl.h"
@@ -115,7 +116,7 @@ namespace internal {
   }
 
 void Object::ObjectVerify(Isolate* isolate) {
-  RuntimeCallTimerScope timer(isolate, RuntimeCallCounterId::kObjectVerify);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kObjectVerify);
   if (IsSmi()) {
     Smi::cast(*this).SmiVerify(isolate);
   } else {
@@ -137,7 +138,7 @@ void MaybeObject::VerifyMaybeObjectPointer(Isolate* isolate, MaybeObject p) {
   if (p->GetHeapObject(&heap_object)) {
     HeapObject::VerifyHeapPointer(isolate, heap_object);
   } else {
-    CHECK(p->IsSmi() || p->IsCleared());
+    CHECK(p->IsSmi() || p->IsCleared() || MapWord::IsPacked(p->ptr()));
   }
 }
 
@@ -457,7 +458,11 @@ void Map::MapVerify(Isolate* isolate) {
         (kTaggedSize <= instance_size() &&
          static_cast<size_t>(instance_size()) < heap->Capacity()));
   if (IsContextMap()) {
-    CHECK(native_context().IsNativeContext());
+    // The map for the NativeContext is allocated before the NativeContext
+    // itself, so it may happen that during a GC the native_context() is still
+    // null.
+    CHECK(native_context_or_null().IsNull() ||
+          native_context().IsNativeContext());
   } else {
     if (GetBackPointer().IsUndefined(isolate)) {
       // Root maps must not have descriptors in the descriptor array that do not
@@ -675,7 +680,7 @@ void SloppyArgumentsElementsVerify(Isolate* isolate,
   for (int i = 0; i < nofMappedParameters; i++) {
     // Verify that each context-mapped argument is either the hole or a valid
     // Smi within context length range.
-    Object mapped = elements.mapped_entries(i);
+    Object mapped = elements.mapped_entries(i, kRelaxedLoad);
     if (mapped.IsTheHole(isolate)) {
       // Slow sloppy arguments can be holey.
       if (!is_fast) continue;
@@ -828,7 +833,6 @@ void JSFunction::JSFunctionVerify(Isolate* isolate) {
 
 void SharedFunctionInfo::SharedFunctionInfoVerify(Isolate* isolate) {
   // TODO(leszeks): Add a TorqueGeneratedClassVerifier for LocalIsolate.
-  TorqueGeneratedClassVerifiers::SharedFunctionInfoVerify(*this, isolate);
   this->SharedFunctionInfoVerify(ReadOnlyRoots(isolate));
 }
 
@@ -1433,7 +1437,7 @@ void JSArrayBufferView::JSArrayBufferViewVerify(Isolate* isolate) {
 
 void JSTypedArray::JSTypedArrayVerify(Isolate* isolate) {
   TorqueGeneratedClassVerifiers::JSTypedArrayVerify(*this, isolate);
-  CHECK_LE(length(), JSTypedArray::kMaxLength);
+  CHECK_LE(GetLength(), JSTypedArray::kMaxLength);
 }
 
 void JSDataView::JSDataViewVerify(Isolate* isolate) {
@@ -1685,7 +1689,13 @@ void AllocationSite::AllocationSiteVerify(Isolate* isolate) {
 
 void Script::ScriptVerify(Isolate* isolate) {
   TorqueGeneratedClassVerifiers::ScriptVerify(*this, isolate);
-  for (int i = 0; i < shared_function_infos().length(); ++i) {
+  if V8_UNLIKELY (type() == Script::TYPE_WEB_SNAPSHOT) {
+    CHECK_LE(shared_function_info_count(), shared_function_infos().length());
+  } else {
+    // No overallocating shared_function_infos.
+    CHECK_EQ(shared_function_info_count(), shared_function_infos().length());
+  }
+  for (int i = 0; i < shared_function_info_count(); ++i) {
     MaybeObject maybe_object = shared_function_infos().Get(i);
     HeapObject heap_object;
     CHECK(maybe_object->IsWeak() || maybe_object->IsCleared() ||
@@ -1736,6 +1746,12 @@ void StackFrameInfo::StackFrameInfoVerify(Isolate* isolate) {
 #endif  // V8_ENABLE_WEBASSEMBLY
 }
 
+void FunctionTemplateRareData::FunctionTemplateRareDataVerify(
+    Isolate* isolate) {
+  CHECK(c_function_overloads().IsFixedArray() ||
+        c_function_overloads().IsUndefined(isolate));
+}
+
 #endif  // VERIFY_HEAP
 
 #ifdef DEBUG
@@ -1795,6 +1811,7 @@ void JSObject::IncrementSpillStatistics(Isolate* isolate,
 #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) case TYPE##_ELEMENTS:
 
       TYPED_ARRAYS(TYPED_ARRAY_CASE)
+      RAB_GSAB_TYPED_ARRAYS(TYPED_ARRAY_CASE)
 #undef TYPED_ARRAY_CASE
       {
         info->number_of_objects_with_fast_elements_++;
diff --git a/chromium/v8/src/diagnostics/objects-printer.cc b/chromium/v8/src/diagnostics/objects-printer.cc
index aa1713e3b37..2c416513a9f 100644
--- a/chromium/v8/src/diagnostics/objects-printer.cc
+++ b/chromium/v8/src/diagnostics/objects-printer.cc
@@ -42,7 +42,7 @@ void Object::Print() const {
   os << std::flush;
 }
 
-void Object::Print(std::ostream& os) const {  // NOLINT
+void Object::Print(std::ostream& os) const {
   if (IsSmi()) {
     os << "Smi: " << std::hex << "0x" << Smi::ToInt(*this);
     os << std::dec << " (" << Smi::ToInt(*this) << ")\n";
@@ -54,7 +54,7 @@ void Object::Print(std::ostream& os) const {  // NOLINT
 namespace {
 
 void PrintHeapObjectHeaderWithoutMap(HeapObject object, std::ostream& os,
-                                     const char* id) {  // NOLINT
+                                     const char* id) {
   os << reinterpret_cast<void*>(object.ptr()) << ": [";
   if (id != nullptr) {
     os << id;
@@ -96,12 +96,12 @@ void PrintDictionaryContents(std::ostream& os, T dict) {
 }
 }  // namespace
 
-void HeapObject::PrintHeader(std::ostream& os, const char* id) {  // NOLINT
+void HeapObject::PrintHeader(std::ostream& os, const char* id) {
   PrintHeapObjectHeaderWithoutMap(*this, os, id);
   if (!IsMap()) os << "\n - map: " << Brief(map());
 }
 
-void HeapObject::HeapObjectPrint(std::ostream& os) {  // NOLINT
+void HeapObject::HeapObjectPrint(std::ostream& os) {
   InstanceType instance_type = map().instance_type();
 
   if (instance_type < FIRST_NONSTRING_TYPE) {
@@ -261,24 +261,24 @@ void HeapObject::HeapObjectPrint(std::ostream& os) {  // NOLINT
   }
 }
 
-void ByteArray::ByteArrayPrint(std::ostream& os) {  // NOLINT
+void ByteArray::ByteArrayPrint(std::ostream& os) {
   PrintHeader(os, "ByteArray");
   os << "\n - length: " << length()
      << "\n - data-start: " << static_cast<void*>(GetDataStartAddress())
      << "\n";
 }
 
-void BytecodeArray::BytecodeArrayPrint(std::ostream& os) {  // NOLINT
+void BytecodeArray::BytecodeArrayPrint(std::ostream& os) {
   PrintHeader(os, "BytecodeArray");
   os << "\n";
   Disassemble(os);
 }
 
-void FreeSpace::FreeSpacePrint(std::ostream& os) {  // NOLINT
+void FreeSpace::FreeSpacePrint(std::ostream& os) {
   os << "free space, size " << Size() << "\n";
 }
 
-bool JSObject::PrintProperties(std::ostream& os) {  // NOLINT
+bool JSObject::PrintProperties(std::ostream& os) {
   if (HasFastProperties()) {
     DescriptorArray descs = map().instance_descriptors(GetIsolate());
     int nof_inobject_properties = map().GetInObjectProperties();
@@ -344,7 +344,7 @@ double GetScalarElement(T array, int index) {
 }
 
 template <class T>
-void DoPrintElements(std::ostream& os, Object object, int length) {  // NOLINT
+void DoPrintElements(std::ostream& os, Object object, int length) {
   const bool print_the_hole = std::is_same<T, FixedDoubleArray>::value;
   T array = T::cast(object);
   if (length == 0) return;
@@ -448,7 +448,7 @@ void PrintSloppyArgumentElements(std::ostream& os, ElementsKind kind,
      << "\n    1: arguments_store: " << Brief(arguments_store)
      << "\n    parameter to context slot map:";
   for (int i = 0; i < elements.length(); i++) {
-    Object mapped_entry = elements.mapped_entries(i);
+    Object mapped_entry = elements.mapped_entries(i, kRelaxedLoad);
     os << "\n    " << i << ": param(" << i << "): " << Brief(mapped_entry);
     if (mapped_entry.IsTheHole()) {
       os << " in the arguments_store[" << i << "]";
@@ -468,20 +468,20 @@ void PrintSloppyArgumentElements(std::ostream& os, ElementsKind kind,
   }
 }
 
-void PrintEmbedderData(PtrComprCageBase cage_base, std::ostream& os,
+void PrintEmbedderData(Isolate* isolate, std::ostream& os,
                        EmbedderDataSlot slot) {
   DisallowGarbageCollection no_gc;
   Object value = slot.load_tagged();
   os << Brief(value);
   void* raw_pointer;
-  if (slot.ToAlignedPointer(cage_base, &raw_pointer)) {
+  if (slot.ToAlignedPointer(isolate, &raw_pointer)) {
     os << ", aligned pointer: " << raw_pointer;
   }
 }
 
 }  // namespace
 
-void JSObject::PrintElements(std::ostream& os) {  // NOLINT
+void JSObject::PrintElements(std::ostream& os) {
   // Don't call GetElementsKind, its validation code can cause the printer to
   // fail when debugging.
   os << " - elements: " << Brief(elements()) << " {";
@@ -508,7 +508,7 @@ void JSObject::PrintElements(std::ostream& os) {  // NOLINT
 
 #define PRINT_ELEMENTS(Type, type, TYPE, elementType)                         \
   case TYPE##_ELEMENTS: {                                                     \
-    size_t length = JSTypedArray::cast(*this).length();                       \
+    size_t length = JSTypedArray::cast(*this).GetLength();                    \
     bool is_on_heap = JSTypedArray::cast(*this).is_on_heap();                 \
     const elementType* data_ptr =                                             \
         static_cast<const elementType*>(JSTypedArray::cast(*this).DataPtr()); \
@@ -516,6 +516,7 @@ void JSObject::PrintElements(std::ostream& os) {  // NOLINT
     break;                                                                    \
   }
       TYPED_ARRAYS(PRINT_ELEMENTS)
+      RAB_GSAB_TYPED_ARRAYS(PRINT_ELEMENTS)
 #undef PRINT_ELEMENTS
 
     case DICTIONARY_ELEMENTS:
@@ -534,7 +535,7 @@ void JSObject::PrintElements(std::ostream& os) {  // NOLINT
 }
 
 static void JSObjectPrintHeader(std::ostream& os, JSObject obj,
-                                const char* id) {  // NOLINT
+                                const char* id) {
   Isolate* isolate = obj.GetIsolate();
   obj.PrintHeader(os, id);
   // Don't call GetElementsKind, its validation code can cause the printer to
@@ -560,8 +561,7 @@ static void JSObjectPrintHeader(std::ostream& os, JSObject obj,
   }
 }
 
-static void JSObjectPrintBody(std::ostream& os,
-                              JSObject obj,  // NOLINT
+static void JSObjectPrintBody(std::ostream& os, JSObject obj,
                               bool print_elements = true) {
   os << "\n - properties: ";
   Object properties_or_hash = obj.raw_properties_or_hash();
@@ -573,28 +573,28 @@ static void JSObjectPrintBody(std::ostream& os,
   os << "}\n";
 
   if (print_elements) {
-    size_t length = obj.IsJSTypedArray() ? JSTypedArray::cast(obj).length()
+    size_t length = obj.IsJSTypedArray() ? JSTypedArray::cast(obj).GetLength()
                                          : obj.elements().length();
     if (length > 0) obj.PrintElements(os);
   }
   int embedder_fields = obj.GetEmbedderFieldCount();
   if (embedder_fields > 0) {
-    PtrComprCageBase cage_base = GetPtrComprCageBase(obj);
+    Isolate* isolate = GetIsolateForHeapSandbox(obj);
     os << " - embedder fields = {";
     for (int i = 0; i < embedder_fields; i++) {
       os << "\n    ";
-      PrintEmbedderData(cage_base, os, EmbedderDataSlot(obj, i));
+      PrintEmbedderData(isolate, os, EmbedderDataSlot(obj, i));
     }
     os << "\n }\n";
   }
 }
 
-void JSObject::JSObjectPrint(std::ostream& os) {  // NOLINT
+void JSObject::JSObjectPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, nullptr);
   JSObjectPrintBody(os, *this);
 }
 
-void JSGeneratorObject::JSGeneratorObjectPrint(std::ostream& os) {  // NOLINT
+void JSGeneratorObject::JSGeneratorObjectPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSGeneratorObject");
   os << "\n - function: " << Brief(function());
   os << "\n - context: " << Brief(context());
@@ -654,13 +654,13 @@ void JSGeneratorObject::JSGeneratorObjectPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintBody(os, *this);
 }
 
-void JSArray::JSArrayPrint(std::ostream& os) {  // NOLINT
+void JSArray::JSArrayPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSArray");
   os << "\n - length: " << Brief(this->length());
   JSObjectPrintBody(os, *this);
 }
 
-void JSPromise::JSPromisePrint(std::ostream& os) {  // NOLINT
+void JSPromise::JSPromisePrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSPromise");
   os << "\n - status: " << JSPromise::Status(status());
   if (status() == Promise::kPending) {
@@ -673,15 +673,14 @@ void JSPromise::JSPromisePrint(std::ostream& os) {  // NOLINT
   JSObjectPrintBody(os, *this);
 }
 
-void JSRegExp::JSRegExpPrint(std::ostream& os) {  // NOLINT
+void JSRegExp::JSRegExpPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSRegExp");
   os << "\n - data: " << Brief(data());
   os << "\n - source: " << Brief(source());
   JSObjectPrintBody(os, *this);
 }
 
-void JSRegExpStringIterator::JSRegExpStringIteratorPrint(
-    std::ostream& os) {  // NOLINT
+void JSRegExpStringIterator::JSRegExpStringIteratorPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSRegExpStringIterator");
   os << "\n - regex: " << Brief(iterating_reg_exp());
   os << "\n - string: " << Brief(iterated_string());
@@ -691,7 +690,7 @@ void JSRegExpStringIterator::JSRegExpStringIteratorPrint(
   JSObjectPrintBody(os, *this);
 }
 
-void Symbol::SymbolPrint(std::ostream& os) {  // NOLINT
+void Symbol::SymbolPrint(std::ostream& os) {
   PrintHeader(os, "Symbol");
   os << "\n - hash: " << hash();
   os << "\n - description: " << Brief(description());
@@ -762,14 +761,14 @@ void ObjectBoilerplateDescription::ObjectBoilerplateDescriptionPrint(
 }
 
 void EmbedderDataArray::EmbedderDataArrayPrint(std::ostream& os) {
-  PtrComprCageBase cage_base = GetPtrComprCageBase(*this);
+  Isolate* isolate = GetIsolateForHeapSandbox(*this);
   PrintHeader(os, "EmbedderDataArray");
   os << "\n - length: " << length();
   EmbedderDataSlot start(*this, 0);
   EmbedderDataSlot end(*this, length());
   for (EmbedderDataSlot slot = start; slot < end; ++slot) {
     os << "\n    ";
-    PrintEmbedderData(cage_base, os, slot);
+    PrintEmbedderData(isolate, os, slot);
   }
   os << "\n";
 }
@@ -779,6 +778,34 @@ void FixedArray::FixedArrayPrint(std::ostream& os) {
 }
 
 namespace {
+const char* SideEffectType2String(SideEffectType type) {
+  switch (type) {
+    case SideEffectType::kHasSideEffect:
+      return "kHasSideEffect";
+    case SideEffectType::kHasNoSideEffect:
+      return "kHasNoSideEffect";
+    case SideEffectType::kHasSideEffectToReceiver:
+      return "kHasSideEffectToReceiver";
+  }
+}
+}  // namespace
+
+void AccessorInfo::AccessorInfoPrint(std::ostream& os) {
+  TorqueGeneratedAccessorInfo<AccessorInfo, Struct>::AccessorInfoPrint(os);
+  os << " - all_can_read: " << all_can_read();
+  os << "\n - all_can_write: " << all_can_write();
+  os << "\n - is_special_data_property: " << is_special_data_property();
+  os << "\n - is_sloppy: " << is_sloppy();
+  os << "\n - replace_on_access: " << replace_on_access();
+  os << "\n - getter_side_effect_type: "
+     << SideEffectType2String(getter_side_effect_type());
+  os << "\n - setter_side_effect_type: "
+     << SideEffectType2String(setter_side_effect_type());
+  os << "\n - initial_attributes: " << initial_property_attributes();
+  os << '\n';
+}
+
+namespace {
 void PrintContextWithHeader(std::ostream& os, Context context,
                             const char* type) {
   context.PrintHeader(os, type);
@@ -1021,7 +1048,7 @@ void SwissNameDictionary::SwissNameDictionaryPrint(std::ostream& os) {
   os.flags(sav_flags);
 }
 
-void PropertyArray::PropertyArrayPrint(std::ostream& os) {  // NOLINT
+void PropertyArray::PropertyArrayPrint(std::ostream& os) {
   PrintHeader(os, "PropertyArray");
   os << "\n - length: " << length();
   os << "\n - hash: " << Hash();
@@ -1029,7 +1056,7 @@ void PropertyArray::PropertyArrayPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void FixedDoubleArray::FixedDoubleArrayPrint(std::ostream& os) {  // NOLINT
+void FixedDoubleArray::FixedDoubleArrayPrint(std::ostream& os) {
   PrintHeader(os, "FixedDoubleArray");
   os << "\n - length: " << length();
   DoPrintElements<FixedDoubleArray>(os, *this, length());
@@ -1051,12 +1078,12 @@ void WeakArrayList::WeakArrayListPrint(std::ostream& os) {
   os << "\n";
 }
 
-void TransitionArray::TransitionArrayPrint(std::ostream& os) {  // NOLINT
+void TransitionArray::TransitionArrayPrint(std::ostream& os) {
   PrintHeader(os, "TransitionArray");
   PrintInternal(os);
 }
 
-void FeedbackCell::FeedbackCellPrint(std::ostream& os) {  // NOLINT
+void FeedbackCell::FeedbackCellPrint(std::ostream& os) {
   PrintHeader(os, "FeedbackCell");
   ReadOnlyRoots roots = GetReadOnlyRoots();
   if (map() == roots.no_closures_cell_map()) {
@@ -1081,7 +1108,7 @@ void FeedbackVectorSpec::Print() {
   os << std::flush;
 }
 
-void FeedbackVectorSpec::FeedbackVectorSpecPrint(std::ostream& os) {  // NOLINT
+void FeedbackVectorSpec::FeedbackVectorSpecPrint(std::ostream& os) {
   os << " - slot_count: " << slot_count();
   if (slot_count() == 0) {
     os << " (empty)\n";
@@ -1116,7 +1143,7 @@ void ClosureFeedbackCellArray::ClosureFeedbackCellArrayPrint(std::ostream& os) {
   PrintFixedArrayWithHeader(os, *this, "ClosureFeedbackCellArray");
 }
 
-void FeedbackVector::FeedbackVectorPrint(std::ostream& os) {  // NOLINT
+void FeedbackVector::FeedbackVectorPrint(std::ostream& os) {
   PrintHeader(os, "FeedbackVector");
   os << "\n - length: " << length();
   if (length() == 0) {
@@ -1157,13 +1184,12 @@ void FeedbackVector::FeedbackVectorPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void FeedbackVector::FeedbackSlotPrint(std::ostream& os,
-                                       FeedbackSlot slot) {  // NOLINT
+void FeedbackVector::FeedbackSlotPrint(std::ostream& os, FeedbackSlot slot) {
   FeedbackNexus nexus(*this, slot);
   nexus.Print(os);
 }
 
-void FeedbackNexus::Print(std::ostream& os) {  // NOLINT
+void FeedbackNexus::Print(std::ostream& os) {
   switch (kind()) {
     case FeedbackSlotKind::kCall:
     case FeedbackSlotKind::kCloneObject:
@@ -1206,7 +1232,7 @@ void FeedbackNexus::Print(std::ostream& os) {  // NOLINT
   }
 }
 
-void Oddball::OddballPrint(std::ostream& os) {  // NOLINT
+void Oddball::OddballPrint(std::ostream& os) {
   PrintHeapObjectHeaderWithoutMap(*this, os, "Oddball");
   os << ": ";
   String s = to_string();
@@ -1216,42 +1242,39 @@ void Oddball::OddballPrint(std::ostream& os) {  // NOLINT
   os << std::endl;
 }
 
-void JSAsyncFunctionObject::JSAsyncFunctionObjectPrint(
-    std::ostream& os) {  // NOLINT
+void JSAsyncFunctionObject::JSAsyncFunctionObjectPrint(std::ostream& os) {
   JSGeneratorObjectPrint(os);
 }
 
-void JSAsyncGeneratorObject::JSAsyncGeneratorObjectPrint(
-    std::ostream& os) {  // NOLINT
+void JSAsyncGeneratorObject::JSAsyncGeneratorObjectPrint(std::ostream& os) {
   JSGeneratorObjectPrint(os);
 }
 
-void JSArgumentsObject::JSArgumentsObjectPrint(std::ostream& os) {  // NOLINT
+void JSArgumentsObject::JSArgumentsObjectPrint(std::ostream& os) {
   JSObjectPrint(os);
 }
 
-void JSStringIterator::JSStringIteratorPrint(std::ostream& os) {  // NOLINT
+void JSStringIterator::JSStringIteratorPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSStringIterator");
   os << "\n - string: " << Brief(string());
   os << "\n - index: " << index();
   JSObjectPrintBody(os, *this);
 }
 
-void JSAsyncFromSyncIterator::JSAsyncFromSyncIteratorPrint(
-    std::ostream& os) {  // NOLINT
+void JSAsyncFromSyncIterator::JSAsyncFromSyncIteratorPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSAsyncFromSyncIterator");
   os << "\n - sync_iterator: " << Brief(sync_iterator());
   os << "\n - next: " << Brief(next());
   JSObjectPrintBody(os, *this);
 }
 
-void JSPrimitiveWrapper::JSPrimitiveWrapperPrint(std::ostream& os) {  // NOLINT
+void JSPrimitiveWrapper::JSPrimitiveWrapperPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSPrimitiveWrapper");
   os << "\n - value: " << Brief(value());
   JSObjectPrintBody(os, *this);
 }
 
-void JSMessageObject::JSMessageObjectPrint(std::ostream& os) {  // NOLINT
+void JSMessageObject::JSMessageObjectPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSMessageObject");
   os << "\n - type: " << static_cast<int>(type());
   os << "\n - arguments: " << Brief(argument());
@@ -1262,7 +1285,7 @@ void JSMessageObject::JSMessageObjectPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintBody(os, *this);
 }
 
-void String::StringPrint(std::ostream& os) {  // NOLINT
+void String::StringPrint(std::ostream& os) {
   PrintHeapObjectHeaderWithoutMap(*this, os, "String");
   os << ": ";
   os << PrefixForDebugPrint();
@@ -1270,7 +1293,7 @@ void String::StringPrint(std::ostream& os) {  // NOLINT
   os << SuffixForDebugPrint();
 }
 
-void Name::NamePrint(std::ostream& os) {  // NOLINT
+void Name::NamePrint(std::ostream& os) {
   if (IsString()) {
     String::cast(*this).StringPrint(os);
   } else {
@@ -1281,7 +1304,7 @@ void Name::NamePrint(std::ostream& os) {  // NOLINT
 static const char* const weekdays[] = {"???", "Sun", "Mon", "Tue",
                                        "Wed", "Thu", "Fri", "Sat"};
 
-void JSDate::JSDatePrint(std::ostream& os) {  // NOLINT
+void JSDate::JSDatePrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSDate");
   os << "\n - value: " << Brief(value());
   if (!year().IsSmi()) {
@@ -1302,7 +1325,7 @@ void JSDate::JSDatePrint(std::ostream& os) {  // NOLINT
   JSObjectPrintBody(os, *this);
 }
 
-void JSProxy::JSProxyPrint(std::ostream& os) {  // NOLINT
+void JSProxy::JSProxyPrint(std::ostream& os) {
   PrintHeader(os, "JSProxy");
   os << "\n - target: ";
   target().ShortPrint(os);
@@ -1311,31 +1334,31 @@ void JSProxy::JSProxyPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void JSSet::JSSetPrint(std::ostream& os) {  // NOLINT
+void JSSet::JSSetPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSSet");
   os << " - table: " << Brief(table());
   JSObjectPrintBody(os, *this);
 }
 
-void JSMap::JSMapPrint(std::ostream& os) {  // NOLINT
+void JSMap::JSMapPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSMap");
   os << " - table: " << Brief(table());
   JSObjectPrintBody(os, *this);
 }
 
-void JSCollectionIterator::JSCollectionIteratorPrint(
-    std::ostream& os, const char* name) {  // NOLINT
+void JSCollectionIterator::JSCollectionIteratorPrint(std::ostream& os,
+                                                     const char* name) {
   JSObjectPrintHeader(os, *this, name);
   os << "\n - table: " << Brief(table());
   os << "\n - index: " << Brief(index());
   JSObjectPrintBody(os, *this);
 }
 
-void JSSetIterator::JSSetIteratorPrint(std::ostream& os) {  // NOLINT
+void JSSetIterator::JSSetIteratorPrint(std::ostream& os) {
   JSCollectionIteratorPrint(os, "JSSetIterator");
 }
 
-void JSMapIterator::JSMapIteratorPrint(std::ostream& os) {  // NOLINT
+void JSMapIterator::JSMapIteratorPrint(std::ostream& os) {
   JSCollectionIteratorPrint(os, "JSMapIterator");
 }
 
@@ -1377,19 +1400,19 @@ void JSFinalizationRegistry::JSFinalizationRegistryPrint(std::ostream& os) {
   JSObjectPrintBody(os, *this);
 }
 
-void JSWeakMap::JSWeakMapPrint(std::ostream& os) {  // NOLINT
+void JSWeakMap::JSWeakMapPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSWeakMap");
   os << "\n - table: " << Brief(table());
   JSObjectPrintBody(os, *this);
 }
 
-void JSWeakSet::JSWeakSetPrint(std::ostream& os) {  // NOLINT
+void JSWeakSet::JSWeakSetPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSWeakSet");
   os << "\n - table: " << Brief(table());
   JSObjectPrintBody(os, *this);
 }
 
-void JSArrayBuffer::JSArrayBufferPrint(std::ostream& os) {  // NOLINT
+void JSArrayBuffer::JSArrayBufferPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSArrayBuffer");
   os << "\n - backing_store: " << backing_store();
   os << "\n - byte_length: " << byte_length();
@@ -1397,15 +1420,16 @@ void JSArrayBuffer::JSArrayBufferPrint(std::ostream& os) {  // NOLINT
   if (is_detachable()) os << "\n - detachable";
   if (was_detached()) os << "\n - detached";
   if (is_shared()) os << "\n - shared";
+  if (is_resizable()) os << "\n - resizable";
   JSObjectPrintBody(os, *this, !was_detached());
 }
 
-void JSTypedArray::JSTypedArrayPrint(std::ostream& os) {  // NOLINT
+void JSTypedArray::JSTypedArrayPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSTypedArray");
   os << "\n - buffer: " << Brief(buffer());
   os << "\n - byte_offset: " << byte_offset();
   os << "\n - byte_length: " << byte_length();
-  os << "\n - length: " << length();
+  os << "\n - length: " << GetLength();
   os << "\n - data_ptr: " << DataPtr();
   Tagged_t base_ptr = static_cast<Tagged_t>(base_pointer().ptr());
   os << "\n   - base_pointer: "
@@ -1417,6 +1441,8 @@ void JSTypedArray::JSTypedArrayPrint(std::ostream& os) {  // NOLINT
     return;
   }
   if (WasDetached()) os << "\n - detached";
+  if (is_length_tracking()) os << "\n - length-tracking";
+  if (is_backed_by_rab()) os << "\n - backed-by-rab";
   JSObjectPrintBody(os, *this, !WasDetached());
 }
 
@@ -1428,7 +1454,7 @@ void JSArrayIterator::JSArrayIteratorPrint(std::ostream& os) {  // NOLING
   JSObjectPrintBody(os, *this);
 }
 
-void JSDataView::JSDataViewPrint(std::ostream& os) {  // NOLINT
+void JSDataView::JSDataViewPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSDataView");
   os << "\n - buffer =" << Brief(buffer());
   os << "\n - byte_offset: " << byte_offset();
@@ -1441,7 +1467,7 @@ void JSDataView::JSDataViewPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintBody(os, *this, !WasDetached());
 }
 
-void JSBoundFunction::JSBoundFunctionPrint(std::ostream& os) {  // NOLINT
+void JSBoundFunction::JSBoundFunctionPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSBoundFunction");
   os << "\n - bound_target_function: " << Brief(bound_target_function());
   os << "\n - bound_this: " << Brief(bound_this());
@@ -1449,7 +1475,7 @@ void JSBoundFunction::JSBoundFunctionPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintBody(os, *this);
 }
 
-void JSFunction::JSFunctionPrint(std::ostream& os) {  // NOLINT
+void JSFunction::JSFunctionPrint(std::ostream& os) {
   Isolate* isolate = GetIsolate();
   JSObjectPrintHeader(os, *this, "Function");
   os << "\n - function prototype: ";
@@ -1525,7 +1551,7 @@ void SharedFunctionInfo::PrintSourceCode(std::ostream& os) {
   }
 }
 
-void SharedFunctionInfo::SharedFunctionInfoPrint(std::ostream& os) {  // NOLINT
+void SharedFunctionInfo::SharedFunctionInfoPrint(std::ostream& os) {
   PrintHeader(os, "SharedFunctionInfo");
   os << "\n - name: ";
   if (HasSharedName()) {
@@ -1576,7 +1602,7 @@ void SharedFunctionInfo::SharedFunctionInfoPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void JSGlobalProxy::JSGlobalProxyPrint(std::ostream& os) {  // NOLINT
+void JSGlobalProxy::JSGlobalProxyPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSGlobalProxy");
   if (!GetIsolate()->bootstrapper()->IsActive()) {
     os << "\n - native context: " << Brief(native_context());
@@ -1584,7 +1610,7 @@ void JSGlobalProxy::JSGlobalProxyPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintBody(os, *this);
 }
 
-void JSGlobalObject::JSGlobalObjectPrint(std::ostream& os) {  // NOLINT
+void JSGlobalObject::JSGlobalObjectPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSGlobalObject");
   if (!GetIsolate()->bootstrapper()->IsActive()) {
     os << "\n - native context: " << Brief(native_context());
@@ -1593,7 +1619,7 @@ void JSGlobalObject::JSGlobalObjectPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintBody(os, *this);
 }
 
-void PropertyCell::PropertyCellPrint(std::ostream& os) {  // NOLINT
+void PropertyCell::PropertyCellPrint(std::ostream& os) {
   PrintHeader(os, "PropertyCell");
   os << "\n - name: ";
   name().NamePrint(os);
@@ -1605,7 +1631,7 @@ void PropertyCell::PropertyCellPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void Code::CodePrint(std::ostream& os) {  // NOLINT
+void Code::CodePrint(std::ostream& os) {
   PrintHeader(os, "Code");
   os << "\n";
 #ifdef ENABLE_DISASSEMBLER
@@ -1613,26 +1639,26 @@ void Code::CodePrint(std::ostream& os) {  // NOLINT
 #endif
 }
 
-void CodeDataContainer::CodeDataContainerPrint(std::ostream& os) {  // NOLINT
+void CodeDataContainer::CodeDataContainerPrint(std::ostream& os) {
   PrintHeader(os, "CodeDataContainer");
   os << "\n - kind_specific_flags: " << kind_specific_flags();
   os << "\n";
 }
 
-void Foreign::ForeignPrint(std::ostream& os) {  // NOLINT
+void Foreign::ForeignPrint(std::ostream& os) {
   PrintHeader(os, "Foreign");
   os << "\n - foreign address : " << reinterpret_cast<void*>(foreign_address());
   os << "\n";
 }
 
-void CallbackTask::CallbackTaskPrint(std::ostream& os) {  // NOLINT
+void CallbackTask::CallbackTaskPrint(std::ostream& os) {
   PrintHeader(os, "CallbackTask");
   os << "\n - callback: " << Brief(callback());
   os << "\n - data: " << Brief(data());
   os << "\n";
 }
 
-void CallableTask::CallableTaskPrint(std::ostream& os) {  // NOLINT
+void CallableTask::CallableTaskPrint(std::ostream& os) {
   PrintHeader(os, "CallableTask");
   os << "\n - context: " << Brief(context());
   os << "\n - callable: " << Brief(callable());
@@ -1640,7 +1666,7 @@ void CallableTask::CallableTaskPrint(std::ostream& os) {  // NOLINT
 }
 
 void PromiseFulfillReactionJobTask::PromiseFulfillReactionJobTaskPrint(
-    std::ostream& os) {  // NOLINT
+    std::ostream& os) {
   PrintHeader(os, "PromiseFulfillReactionJobTask");
   os << "\n - argument: " << Brief(argument());
   os << "\n - context: " << Brief(context());
@@ -1650,7 +1676,7 @@ void PromiseFulfillReactionJobTask::PromiseFulfillReactionJobTaskPrint(
 }
 
 void PromiseRejectReactionJobTask::PromiseRejectReactionJobTaskPrint(
-    std::ostream& os) {  // NOLINT
+    std::ostream& os) {
   PrintHeader(os, "PromiseRejectReactionJobTask");
   os << "\n - argument: " << Brief(argument());
   os << "\n - context: " << Brief(context());
@@ -1660,7 +1686,7 @@ void PromiseRejectReactionJobTask::PromiseRejectReactionJobTaskPrint(
 }
 
 void PromiseResolveThenableJobTask::PromiseResolveThenableJobTaskPrint(
-    std::ostream& os) {  // NOLINT
+    std::ostream& os) {
   PrintHeader(os, "PromiseResolveThenableJobTask");
   os << "\n - context: " << Brief(context());
   os << "\n - promise_to_resolve: " << Brief(promise_to_resolve());
@@ -1669,7 +1695,7 @@ void PromiseResolveThenableJobTask::PromiseResolveThenableJobTaskPrint(
   os << "\n";
 }
 
-void PromiseCapability::PromiseCapabilityPrint(std::ostream& os) {  // NOLINT
+void PromiseCapability::PromiseCapabilityPrint(std::ostream& os) {
   PrintHeader(os, "PromiseCapability");
   os << "\n - promise: " << Brief(promise());
   os << "\n - resolve: " << Brief(resolve());
@@ -1677,7 +1703,7 @@ void PromiseCapability::PromiseCapabilityPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void PromiseReaction::PromiseReactionPrint(std::ostream& os) {  // NOLINT
+void PromiseReaction::PromiseReactionPrint(std::ostream& os) {
   PrintHeader(os, "PromiseReaction");
   os << "\n - next: " << Brief(next());
   os << "\n - reject_handler: " << Brief(reject_handler());
@@ -1686,8 +1712,7 @@ void PromiseReaction::PromiseReactionPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void AsyncGeneratorRequest::AsyncGeneratorRequestPrint(
-    std::ostream& os) {  // NOLINT
+void AsyncGeneratorRequest::AsyncGeneratorRequestPrint(std::ostream& os) {
   PrintHeader(os, "AsyncGeneratorRequest");
   const char* mode = "Invalid!";
   switch (resume_mode()) {
@@ -1708,7 +1733,7 @@ void AsyncGeneratorRequest::AsyncGeneratorRequestPrint(
 }
 
 void SourceTextModuleInfoEntry::SourceTextModuleInfoEntryPrint(
-    std::ostream& os) {  // NOLINT
+    std::ostream& os) {
   PrintHeader(os, "SourceTextModuleInfoEntry");
   os << "\n - export_name: " << Brief(export_name());
   os << "\n - local_name: " << Brief(local_name());
@@ -1726,7 +1751,7 @@ static void PrintModuleFields(Module module, std::ostream& os) {
   os << "\n - exception: " << Brief(module.exception());
 }
 
-void Module::ModulePrint(std::ostream& os) {  // NOLINT
+void Module::ModulePrint(std::ostream& os) {
   if (this->IsSourceTextModule()) {
     SourceTextModule::cast(*this).SourceTextModulePrint(os);
   } else if (this->IsSyntheticModule()) {
@@ -1736,7 +1761,7 @@ void Module::ModulePrint(std::ostream& os) {  // NOLINT
   }
 }
 
-void SourceTextModule::SourceTextModulePrint(std::ostream& os) {  // NOLINT
+void SourceTextModule::SourceTextModulePrint(std::ostream& os) {
   PrintHeader(os, "SourceTextModule");
   PrintModuleFields(*this, os);
   os << "\n - sfi/code/info: " << Brief(code());
@@ -1744,13 +1769,13 @@ void SourceTextModule::SourceTextModulePrint(std::ostream& os) {  // NOLINT
   os << "\n - script: " << Brief(script);
   os << "\n - origin: " << Brief(script.GetNameOrSourceURL());
   os << "\n - requested_modules: " << Brief(requested_modules());
-  os << "\n - import_meta: " << Brief(import_meta());
+  os << "\n - import_meta: " << Brief(import_meta(kAcquireLoad));
   os << "\n - cycle_root: " << Brief(cycle_root());
   os << "\n - async_evaluating_ordinal: " << async_evaluating_ordinal();
   os << "\n";
 }
 
-void SyntheticModule::SyntheticModulePrint(std::ostream& os) {  // NOLINT
+void SyntheticModule::SyntheticModulePrint(std::ostream& os) {
   PrintHeader(os, "SyntheticModule");
   PrintModuleFields(*this, os);
   os << "\n - export_names: " << Brief(export_names());
@@ -1758,13 +1783,13 @@ void SyntheticModule::SyntheticModulePrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void JSModuleNamespace::JSModuleNamespacePrint(std::ostream& os) {  // NOLINT
+void JSModuleNamespace::JSModuleNamespacePrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSModuleNamespace");
   os << "\n - module: " << Brief(module());
   JSObjectPrintBody(os, *this);
 }
 
-void PrototypeInfo::PrototypeInfoPrint(std::ostream& os) {  // NOLINT
+void PrototypeInfo::PrototypeInfoPrint(std::ostream& os) {
   PrintHeader(os, "PrototypeInfo");
   os << "\n - module namespace: " << Brief(module_namespace());
   os << "\n - prototype users: " << Brief(prototype_users());
@@ -1774,7 +1799,7 @@ void PrototypeInfo::PrototypeInfoPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void ClassPositions::ClassPositionsPrint(std::ostream& os) {  // NOLINT
+void ClassPositions::ClassPositionsPrint(std::ostream& os) {
   PrintHeader(os, "ClassPositions");
   os << "\n - start position: " << start();
   os << "\n - end position: " << end();
@@ -1782,15 +1807,15 @@ void ClassPositions::ClassPositionsPrint(std::ostream& os) {  // NOLINT
 }
 
 void ArrayBoilerplateDescription::ArrayBoilerplateDescriptionPrint(
-    std::ostream& os) {  // NOLINT
+    std::ostream& os) {
   PrintHeader(os, "ArrayBoilerplateDescription");
-  os << "\n - elements kind: " << elements_kind();
+  os << "\n - elements kind: " << ElementsKindToString(elements_kind());
   os << "\n - constant elements: " << Brief(constant_elements());
   os << "\n";
 }
 
 void RegExpBoilerplateDescription::RegExpBoilerplateDescriptionPrint(
-    std::ostream& os) {  // NOLINT
+    std::ostream& os) {
   PrintHeader(os, "RegExpBoilerplateDescription");
   os << "\n - data: " << Brief(data());
   os << "\n - source: " << Brief(source());
@@ -1799,7 +1824,7 @@ void RegExpBoilerplateDescription::RegExpBoilerplateDescriptionPrint(
 }
 
 #if V8_ENABLE_WEBASSEMBLY
-void AsmWasmData::AsmWasmDataPrint(std::ostream& os) {  // NOLINT
+void AsmWasmData::AsmWasmDataPrint(std::ostream& os) {
   PrintHeader(os, "AsmWasmData");
   os << "\n - native module: " << Brief(managed_native_module());
   os << "\n - export_wrappers: " << Brief(export_wrappers());
@@ -1807,13 +1832,13 @@ void AsmWasmData::AsmWasmDataPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void WasmTypeInfo::WasmTypeInfoPrint(std::ostream& os) {  // NOLINT
+void WasmTypeInfo::WasmTypeInfoPrint(std::ostream& os) {
   PrintHeader(os, "WasmTypeInfo");
   os << "\n - type address: " << reinterpret_cast<void*>(foreign_address());
   os << "\n";
 }
 
-void WasmStruct::WasmStructPrint(std::ostream& os) {  // NOLINT
+void WasmStruct::WasmStructPrint(std::ostream& os) {
   PrintHeader(os, "WasmStruct");
   wasm::StructType* struct_type = type();
   os << "\n - fields (" << struct_type->field_count() << "):";
@@ -1851,7 +1876,7 @@ void WasmStruct::WasmStructPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void WasmArray::WasmArrayPrint(std::ostream& os) {  // NOLINT
+void WasmArray::WasmArrayPrint(std::ostream& os) {
   PrintHeader(os, "WasmArray");
   wasm::ArrayType* array_type = type();
   uint32_t len = length();
@@ -1891,13 +1916,13 @@ void WasmArray::WasmArrayPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void WasmExceptionTag::WasmExceptionTagPrint(std::ostream& os) {  // NOLINT
+void WasmExceptionTag::WasmExceptionTagPrint(std::ostream& os) {
   PrintHeader(os, "WasmExceptionTag");
   os << "\n - index: " << index();
   os << "\n";
 }
 
-void WasmInstanceObject::WasmInstanceObjectPrint(std::ostream& os) {  // NOLINT
+void WasmInstanceObject::WasmInstanceObjectPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "WasmInstanceObject");
   os << "\n - module_object: " << Brief(module_object());
   os << "\n - exports_object: " << Brief(exports_object());
@@ -1944,24 +1969,35 @@ void WasmInstanceObject::WasmInstanceObjectPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void WasmExportedFunctionData::WasmExportedFunctionDataPrint(
-    std::ostream& os) {  // NOLINT
+// Never called directly, as WasmFunctionData is an "abstract" class.
+void WasmFunctionData::WasmFunctionDataPrint(std::ostream& os) {
+  os << "\n - target: " << reinterpret_cast<void*>(foreign_address());
+  os << "\n - ref: " << Brief(ref());
+}
+
+void WasmExportedFunctionData::WasmExportedFunctionDataPrint(std::ostream& os) {
   PrintHeader(os, "WasmExportedFunctionData");
+  WasmFunctionDataPrint(os);
   os << "\n - wrapper_code: " << Brief(wrapper_code());
   os << "\n - instance: " << Brief(instance());
-  os << "\n - jump_table_offset: " << jump_table_offset();
   os << "\n - function_index: " << function_index();
+  os << "\n - signature: " << Brief(signature());
+  os << "\n - wrapper_budget: " << wrapper_budget();
   os << "\n";
 }
 
-void WasmJSFunctionData::WasmJSFunctionDataPrint(std::ostream& os) {  // NOLINT
+void WasmJSFunctionData::WasmJSFunctionDataPrint(std::ostream& os) {
   PrintHeader(os, "WasmJSFunctionData");
-  os << "\n - callable: " << Brief(callable());
+  WasmFunctionDataPrint(os);
   os << "\n - wrapper_code: " << Brief(wrapper_code());
+  os << "\n - wasm_to_js_wrapper_code: " << Brief(wasm_to_js_wrapper_code());
+  os << "\n - serialized_return_count: " << serialized_return_count();
+  os << "\n - serialized_parameter_count: " << serialized_parameter_count();
+  os << "\n - serialized signature: " << Brief(serialized_signature());
   os << "\n";
 }
 
-void WasmModuleObject::WasmModuleObjectPrint(std::ostream& os) {  // NOLINT
+void WasmModuleObject::WasmModuleObjectPrint(std::ostream& os) {
   PrintHeader(os, "WasmModuleObject");
   os << "\n - module: " << module();
   os << "\n - native module: " << native_module();
@@ -1970,7 +2006,7 @@ void WasmModuleObject::WasmModuleObjectPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void WasmTableObject::WasmTableObjectPrint(std::ostream& os) {  // NOLINT
+void WasmTableObject::WasmTableObjectPrint(std::ostream& os) {
   PrintHeader(os, "WasmTableObject");
   os << "\n - elements: " << Brief(elements());
   os << "\n - maximum_length: " << Brief(maximum_length());
@@ -1979,7 +2015,7 @@ void WasmTableObject::WasmTableObjectPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void WasmGlobalObject::WasmGlobalObjectPrint(std::ostream& os) {  // NOLINT
+void WasmGlobalObject::WasmGlobalObjectPrint(std::ostream& os) {
   PrintHeader(os, "WasmGlobalObject");
   if (type().is_reference()) {
     os << "\n - tagged_buffer: " << Brief(tagged_buffer());
@@ -1994,7 +2030,7 @@ void WasmGlobalObject::WasmGlobalObjectPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void WasmMemoryObject::WasmMemoryObjectPrint(std::ostream& os) {  // NOLINT
+void WasmMemoryObject::WasmMemoryObjectPrint(std::ostream& os) {
   PrintHeader(os, "WasmMemoryObject");
   os << "\n - array_buffer: " << Brief(array_buffer());
   os << "\n - maximum_pages: " << maximum_pages();
@@ -2002,8 +2038,7 @@ void WasmMemoryObject::WasmMemoryObjectPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void WasmExceptionObject::WasmExceptionObjectPrint(
-    std::ostream& os) {  // NOLINT
+void WasmExceptionObject::WasmExceptionObjectPrint(std::ostream& os) {
   PrintHeader(os, "WasmExceptionObject");
   os << "\n - serialized_signature: " << Brief(serialized_signature());
   os << "\n - exception_tag: " << Brief(exception_tag());
@@ -2024,14 +2059,14 @@ void WasmIndirectFunctionTable::WasmIndirectFunctionTablePrint(
   os << "\n";
 }
 
-void WasmValueObject::WasmValueObjectPrint(std::ostream& os) {  // NOLINT
+void WasmValueObject::WasmValueObjectPrint(std::ostream& os) {
   PrintHeader(os, "WasmValueObject");
   os << "\n - value: " << Brief(value());
   os << "\n";
 }
 #endif  // V8_ENABLE_WEBASSEMBLY
 
-void LoadHandler::LoadHandlerPrint(std::ostream& os) {  // NOLINT
+void LoadHandler::LoadHandlerPrint(std::ostream& os) {
   PrintHeader(os, "LoadHandler");
   // TODO(ishell): implement printing based on handler kind
   os << "\n - handler: " << Brief(smi_handler());
@@ -2049,7 +2084,7 @@ void LoadHandler::LoadHandlerPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void StoreHandler::StoreHandlerPrint(std::ostream& os) {  // NOLINT
+void StoreHandler::StoreHandlerPrint(std::ostream& os) {
   PrintHeader(os, "StoreHandler");
   // TODO(ishell): implement printing based on handler kind
   os << "\n - handler: " << Brief(smi_handler());
@@ -2067,14 +2102,14 @@ void StoreHandler::StoreHandlerPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void AccessorPair::AccessorPairPrint(std::ostream& os) {  // NOLINT
+void AccessorPair::AccessorPairPrint(std::ostream& os) {
   PrintHeader(os, "AccessorPair");
   os << "\n - getter: " << Brief(getter());
   os << "\n - setter: " << Brief(setter());
   os << "\n";
 }
 
-void CallHandlerInfo::CallHandlerInfoPrint(std::ostream& os) {  // NOLINT
+void CallHandlerInfo::CallHandlerInfoPrint(std::ostream& os) {
   PrintHeader(os, "CallHandlerInfo");
   os << "\n - callback: " << Brief(callback());
   os << "\n - js_callback: " << Brief(js_callback());
@@ -2084,8 +2119,7 @@ void CallHandlerInfo::CallHandlerInfoPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void FunctionTemplateInfo::FunctionTemplateInfoPrint(
-    std::ostream& os) {  // NOLINT
+void FunctionTemplateInfo::FunctionTemplateInfoPrint(std::ostream& os) {
   PrintHeader(os, "FunctionTemplateInfo");
   os << "\n - class name: " << Brief(class_name());
   os << "\n - tag: " << tag();
@@ -2102,7 +2136,7 @@ void FunctionTemplateInfo::FunctionTemplateInfoPrint(
   os << "\n";
 }
 
-void ObjectTemplateInfo::ObjectTemplateInfoPrint(std::ostream& os) {  // NOLINT
+void ObjectTemplateInfo::ObjectTemplateInfoPrint(std::ostream& os) {
   PrintHeader(os, "ObjectTemplateInfo");
   os << "\n - tag: " << tag();
   os << "\n - serial_number: " << serial_number();
@@ -2114,7 +2148,7 @@ void ObjectTemplateInfo::ObjectTemplateInfoPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void AllocationSite::AllocationSitePrint(std::ostream& os) {  // NOLINT
+void AllocationSite::AllocationSitePrint(std::ostream& os) {
   PrintHeader(os, "AllocationSite");
   if (this->HasWeakNext()) os << "\n - weak_next: " << Brief(weak_next());
   os << "\n - dependent code: " << Brief(dependent_code());
@@ -2137,7 +2171,7 @@ void AllocationSite::AllocationSitePrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void AllocationMemento::AllocationMementoPrint(std::ostream& os) {  // NOLINT
+void AllocationMemento::AllocationMementoPrint(std::ostream& os) {
   PrintHeader(os, "AllocationMemento");
   os << "\n - allocation site: ";
   if (IsValid()) {
@@ -2147,7 +2181,7 @@ void AllocationMemento::AllocationMementoPrint(std::ostream& os) {  // NOLINT
   }
 }
 
-void Script::ScriptPrint(std::ostream& os) {  // NOLINT
+void Script::ScriptPrint(std::ostream& os) {
   PrintHeader(os, "Script");
   os << "\n - source: " << Brief(source());
   os << "\n - name: " << Brief(name());
@@ -2170,9 +2204,11 @@ void Script::ScriptPrint(std::ostream& os) {  // NOLINT
   if (!is_wasm) {
     if (has_eval_from_shared()) {
       os << "\n - eval from shared: " << Brief(eval_from_shared());
-    }
-    if (is_wrapped()) {
+    } else if (is_wrapped()) {
       os << "\n - wrapped arguments: " << Brief(wrapped_arguments());
+    } else if (type() == TYPE_WEB_SNAPSHOT) {
+      os << "\n - shared function info table: "
+         << Brief(shared_function_info_table());
     }
     os << "\n - eval from position: " << eval_from_position();
   }
@@ -2181,7 +2217,7 @@ void Script::ScriptPrint(std::ostream& os) {  // NOLINT
 }
 
 #ifdef V8_INTL_SUPPORT
-void JSV8BreakIterator::JSV8BreakIteratorPrint(std::ostream& os) {  // NOLINT
+void JSV8BreakIterator::JSV8BreakIteratorPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSV8BreakIterator");
   os << "\n - locale: " << Brief(locale());
   os << "\n - break iterator: " << Brief(break_iterator());
@@ -2194,14 +2230,14 @@ void JSV8BreakIterator::JSV8BreakIteratorPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void JSCollator::JSCollatorPrint(std::ostream& os) {  // NOLINT
+void JSCollator::JSCollatorPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSCollator");
   os << "\n - icu collator: " << Brief(icu_collator());
   os << "\n - bound compare: " << Brief(bound_compare());
   JSObjectPrintBody(os, *this);
 }
 
-void JSDateTimeFormat::JSDateTimeFormatPrint(std::ostream& os) {  // NOLINT
+void JSDateTimeFormat::JSDateTimeFormatPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSDateTimeFormat");
   os << "\n - locale: " << Brief(locale());
   os << "\n - icu locale: " << Brief(icu_locale());
@@ -2212,7 +2248,7 @@ void JSDateTimeFormat::JSDateTimeFormatPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintBody(os, *this);
 }
 
-void JSDisplayNames::JSDisplayNamesPrint(std::ostream& os) {  // NOLINT
+void JSDisplayNames::JSDisplayNamesPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSDisplayNames");
   os << "\n - internal: " << Brief(internal());
   os << "\n - style: " << StyleAsString();
@@ -2220,7 +2256,7 @@ void JSDisplayNames::JSDisplayNamesPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintBody(os, *this);
 }
 
-void JSListFormat::JSListFormatPrint(std::ostream& os) {  // NOLINT
+void JSListFormat::JSListFormatPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSListFormat");
   os << "\n - locale: " << Brief(locale());
   os << "\n - style: " << StyleAsString();
@@ -2229,13 +2265,13 @@ void JSListFormat::JSListFormatPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintBody(os, *this);
 }
 
-void JSLocale::JSLocalePrint(std::ostream& os) {  // NOLINT
+void JSLocale::JSLocalePrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSLocale");
   os << "\n - icu locale: " << Brief(icu_locale());
   JSObjectPrintBody(os, *this);
 }
 
-void JSNumberFormat::JSNumberFormatPrint(std::ostream& os) {  // NOLINT
+void JSNumberFormat::JSNumberFormatPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSNumberFormat");
   os << "\n - locale: " << Brief(locale());
   os << "\n - icu_number_formatter: " << Brief(icu_number_formatter());
@@ -2243,7 +2279,7 @@ void JSNumberFormat::JSNumberFormatPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintBody(os, *this);
 }
 
-void JSPluralRules::JSPluralRulesPrint(std::ostream& os) {  // NOLINT
+void JSPluralRules::JSPluralRulesPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSPluralRules");
   os << "\n - locale: " << Brief(locale());
   os << "\n - type: " << TypeAsString();
@@ -2252,8 +2288,7 @@ void JSPluralRules::JSPluralRulesPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintBody(os, *this);
 }
 
-void JSRelativeTimeFormat::JSRelativeTimeFormatPrint(
-    std::ostream& os) {  // NOLINT
+void JSRelativeTimeFormat::JSRelativeTimeFormatPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSRelativeTimeFormat");
   os << "\n - locale: " << Brief(locale());
   os << "\n - numberingSystem: " << Brief(numberingSystem());
@@ -2262,14 +2297,14 @@ void JSRelativeTimeFormat::JSRelativeTimeFormatPrint(
   os << "\n";
 }
 
-void JSSegmentIterator::JSSegmentIteratorPrint(std::ostream& os) {  // NOLINT
+void JSSegmentIterator::JSSegmentIteratorPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSSegmentIterator");
   os << "\n - icu break iterator: " << Brief(icu_break_iterator());
   os << "\n - granularity: " << GranularityAsString(GetIsolate());
   os << "\n";
 }
 
-void JSSegmenter::JSSegmenterPrint(std::ostream& os) {  // NOLINT
+void JSSegmenter::JSSegmenterPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSSegmenter");
   os << "\n - locale: " << Brief(locale());
   os << "\n - granularity: " << GranularityAsString(GetIsolate());
@@ -2277,7 +2312,7 @@ void JSSegmenter::JSSegmenterPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintBody(os, *this);
 }
 
-void JSSegments::JSSegmentsPrint(std::ostream& os) {  // NOLINT
+void JSSegments::JSSegmentsPrint(std::ostream& os) {
   JSObjectPrintHeader(os, *this, "JSSegments");
   os << "\n - icu break iterator: " << Brief(icu_break_iterator());
   os << "\n - unicode string: " << Brief(unicode_string());
@@ -2301,7 +2336,7 @@ void PrintScopeInfoList(ScopeInfo scope_info, std::ostream& os,
 }
 }  // namespace
 
-void ScopeInfo::ScopeInfoPrint(std::ostream& os) {  // NOLINT
+void ScopeInfo::ScopeInfoPrint(std::ostream& os) {
   PrintHeader(os, "ScopeInfo");
   if (IsEmpty()) {
     os << "\n - empty\n";
@@ -2357,7 +2392,7 @@ void ScopeInfo::ScopeInfoPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void StackFrameInfo::StackFrameInfoPrint(std::ostream& os) {  // NOLINT
+void StackFrameInfo::StackFrameInfoPrint(std::ostream& os) {
   PrintHeader(os, "StackFrameInfo");
   os << "\n - receiver_or_instance: " << Brief(receiver_or_instance());
   os << "\n - function: " << Brief(function());
@@ -2369,7 +2404,7 @@ void StackFrameInfo::StackFrameInfoPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void PreparseData::PreparseDataPrint(std::ostream& os) {  // NOLINT
+void PreparseData::PreparseDataPrint(std::ostream& os) {
   PrintHeader(os, "PreparseData");
   os << "\n - data_length: " << data_length();
   os << "\n - children_length: " << children_length();
@@ -2385,7 +2420,7 @@ void PreparseData::PreparseDataPrint(std::ostream& os) {  // NOLINT
   os << "\n";
 }
 
-void InterpreterData::InterpreterDataPrint(std::ostream& os) {  // NOLINT
+void InterpreterData::InterpreterDataPrint(std::ostream& os) {
   PrintHeader(os, "InterpreterData");
   os << "\n - bytecode_array: " << Brief(bytecode_array());
   os << "\n - interpreter_trampoline: " << Brief(interpreter_trampoline());
@@ -2480,7 +2515,7 @@ void Map::PrintMapDetails(std::ostream& os) {
   instance_descriptors().PrintDescriptors(os);
 }
 
-void Map::MapPrint(std::ostream& os) {  // NOLINT
+void Map::MapPrint(std::ostream& os) {
 #ifdef OBJECT_PRINT
   PrintHeader(os, "Map");
 #else
@@ -2662,7 +2697,7 @@ void TransitionArray::PrintInternal(std::ostream& os) {
   os << "\n" << std::flush;
 }
 
-void TransitionsAccessor::PrintTransitions(std::ostream& os) {  // NOLINT
+void TransitionsAccessor::PrintTransitions(std::ostream& os) {
   switch (encoding()) {
     case kPrototypeInfo:
     case kUninitialized:
@@ -2730,7 +2765,7 @@ void TransitionsAccessor::PrintTransitionTree(
   }
 }
 
-void JSObject::PrintTransitions(std::ostream& os) {  // NOLINT
+void JSObject::PrintTransitions(std::ostream& os) {
   DisallowGarbageCollection no_gc;
   TransitionsAccessor ta(GetIsolate(), map(), &no_gc);
   if (ta.NumberOfTransitions() == 0) return;
@@ -2770,6 +2805,22 @@ V8_EXPORT_PRIVATE extern void _v8_internal_Print_Object(void* object) {
   GetObjectFromRaw(object).Print();
 }
 
+V8_EXPORT_PRIVATE extern void _v8_internal_Print_LoadHandler(void* object) {
+#ifdef OBJECT_PRINT
+  i::StdoutStream os;
+  i::LoadHandler::PrintHandler(GetObjectFromRaw(object), os);
+  os << std::flush;
+#endif
+}
+
+V8_EXPORT_PRIVATE extern void _v8_internal_Print_StoreHandler(void* object) {
+#ifdef OBJECT_PRINT
+  i::StdoutStream os;
+  i::StoreHandler::PrintHandler(GetObjectFromRaw(object), os);
+  os << std::flush;
+#endif
+}
+
 V8_EXPORT_PRIVATE extern void _v8_internal_Print_Code(void* object) {
   i::Address address = reinterpret_cast<i::Address>(object);
   i::Isolate* isolate = i::Isolate::Current();
diff --git a/chromium/v8/src/diagnostics/perf-jit.cc b/chromium/v8/src/diagnostics/perf-jit.cc
index dea33400480..e5cc93c1f63 100644
--- a/chromium/v8/src/diagnostics/perf-jit.cc
+++ b/chromium/v8/src/diagnostics/perf-jit.cc
@@ -215,7 +215,6 @@ void PerfJitLogger::LogRecordedBuffer(
   if (FLAG_perf_basic_prof_only_functions &&
       (abstract_code->kind() != CodeKind::INTERPRETED_FUNCTION &&
        abstract_code->kind() != CodeKind::TURBOFAN &&
-       abstract_code->kind() != CodeKind::NATIVE_CONTEXT_INDEPENDENT &&
        abstract_code->kind() != CodeKind::TURBOPROP &&
        abstract_code->kind() != CodeKind::BASELINE)) {
     return;
diff --git a/chromium/v8/src/diagnostics/ppc/disasm-ppc.cc b/chromium/v8/src/diagnostics/ppc/disasm-ppc.cc
index 9757c8901bf..724e08cc453 100644
--- a/chromium/v8/src/diagnostics/ppc/disasm-ppc.cc
+++ b/chromium/v8/src/diagnostics/ppc/disasm-ppc.cc
@@ -408,6 +408,16 @@ void Decoder::UnknownFormat(Instruction* instr, const char* name) {
 }
 
 void Decoder::DecodeExt0(Instruction* instr) {
+  // Some encodings have integers hard coded in the middle, handle those first.
+  switch (EXT0 | (instr->BitField(20, 16)) | (instr->BitField(10, 0))) {
+#define DECODE_VX_D_FORM__INSTRUCTIONS(name, opcode_name, opcode_value) \
+  case opcode_name: {                                                   \
+    Format(instr, #name " 'Vt, 'Vb");                                   \
+    return;                                                             \
+  }
+    PPC_VX_OPCODE_D_FORM_LIST(DECODE_VX_D_FORM__INSTRUCTIONS)
+#undef DECODE_VX_D_FORM__INSTRUCTIONS
+  }
   // Some encodings are 5-0 bits, handle those first
   switch (EXT0 | (instr->BitField(5, 0))) {
 #define DECODE_VA_A_FORM__INSTRUCTIONS(name, opcode_name, opcode_value) \
@@ -638,6 +648,10 @@ void Decoder::DecodeExt2(Instruction* instr) {
       Format(instr, "lxvd    'Xt, 'ra, 'rb");
       return;
     }
+    case LXVX: {
+      Format(instr, "lxvx    'Xt, 'ra, 'rb");
+      return;
+    }
     case LXSDX: {
       Format(instr, "lxsdx    'Xt, 'ra, 'rb");
       return;
@@ -658,6 +672,10 @@ void Decoder::DecodeExt2(Instruction* instr) {
       Format(instr, "stxvd   'Xs, 'ra, 'rb");
       return;
     }
+    case STXVX: {
+      Format(instr, "stxvx   'Xs, 'ra, 'rb");
+      return;
+    }
     case STXSDX: {
       Format(instr, "stxsdx  'Xs, 'ra, 'rb");
       return;
@@ -1277,12 +1295,6 @@ void Decoder::DecodeExt5(Instruction* instr) {
 }
 
 void Decoder::DecodeExt6(Instruction* instr) {
-  switch (EXT6 | (instr->BitField(10, 2))) {
-    case XXBRQ: {
-      Format(instr, "xxbrq  'Xt, 'Xb");
-      return;
-    }
-  }
   switch (EXT6 | (instr->BitField(10, 1))) {
     case XXSPLTIB: {
       Format(instr, "xxspltib  'Xt, 'IMM8");
@@ -1298,6 +1310,16 @@ void Decoder::DecodeExt6(Instruction* instr) {
     PPC_XX3_OPCODE_LIST(DECODE_XX3_INSTRUCTIONS)
 #undef DECODE_XX3_INSTRUCTIONS
   }
+  // Some encodings have integers hard coded in the middle, handle those first.
+  switch (EXT6 | (instr->BitField(20, 16)) | (instr->BitField(10, 2))) {
+#define DECODE_XX2_B_INSTRUCTIONS(name, opcode_name, opcode_value) \
+  case opcode_name: {                                              \
+    Format(instr, #name " 'Xt, 'Xb");                              \
+    return;                                                        \
+  }
+    PPC_XX2_OPCODE_B_FORM_LIST(DECODE_XX2_B_INSTRUCTIONS)
+#undef DECODE_XX2_B_INSTRUCTIONS
+  }
   switch (EXT6 | (instr->BitField(10, 2))) {
 #define DECODE_XX2_A_INSTRUCTIONS(name, opcode_name, opcode_value) \
   case opcode_name: {                                              \
@@ -1305,8 +1327,8 @@ void Decoder::DecodeExt6(Instruction* instr) {
     return;                                                        \
   }
     PPC_XX2_OPCODE_A_FORM_LIST(DECODE_XX2_A_INSTRUCTIONS)
-  }
 #undef DECODE_XX2_A_INSTRUCTIONS
+  }
   Unknown(instr);  // not used by V8
 }
 
diff --git a/chromium/v8/src/diagnostics/riscv64/disasm-riscv64.cc b/chromium/v8/src/diagnostics/riscv64/disasm-riscv64.cc
index a39261555d1..5cbd4b4857f 100644
--- a/chromium/v8/src/diagnostics/riscv64/disasm-riscv64.cc
+++ b/chromium/v8/src/diagnostics/riscv64/disasm-riscv64.cc
@@ -122,6 +122,8 @@ class Decoder {
   // Printing of instruction name.
   void PrintInstructionName(Instruction* instr);
 
+  void PrintTarget(Instruction* instr);
+
   // Handle formatting of instructions and their options.
   int FormatRegister(Instruction* instr, const char* option);
   int FormatFPURegisterOrRoundMode(Instruction* instr, const char* option);
@@ -213,6 +215,21 @@ void Decoder::PrintImm12(Instruction* instr) {
   out_buffer_pos_ += SNPrintF(out_buffer_ + out_buffer_pos_, "%d", imm);
 }
 
+void Decoder::PrintTarget(Instruction* instr) {
+  if (Assembler::IsJalr(instr->InstructionBits())) {
+    if (Assembler::IsAuipc((instr - 4)->InstructionBits()) &&
+        (instr - 4)->RdValue() == instr->Rs1Value()) {
+      int32_t imm = Assembler::BrachlongOffset((instr - 4)->InstructionBits(),
+                                               instr->InstructionBits());
+      const char* target =
+          converter_.NameOfAddress(reinterpret_cast<byte*>(instr - 4) + imm);
+      out_buffer_pos_ +=
+          SNPrintF(out_buffer_ + out_buffer_pos_, " -> %s", target);
+      return;
+    }
+  }
+}
+
 void Decoder::PrintBranchOffset(Instruction* instr) {
   int32_t imm = instr->BranchOffset();
   const char* target =
@@ -699,6 +716,11 @@ int Decoder::FormatOption(Instruction* instr, const char* format) {
       PrintVs1(instr);
       return 3;
     }
+    case 't': {  // 'target: target of branch instructions'
+      DCHECK(STRING_STARTS_WITH(format, "target"));
+      PrintTarget(instr);
+      return 6;
+    }
   }
   UNREACHABLE();
 }
@@ -1280,7 +1302,7 @@ void Decoder::DecodeIType(Instruction* instr) {
       else if (instr->RdValue() == ra.code() && instr->Imm12Value() == 0)
         Format(instr, "jalr      'rs1");
       else
-        Format(instr, "jalr      'rd, 'imm12('rs1)");
+        Format(instr, "jalr      'rd, 'imm12('rs1)'target");
       break;
     case RO_LB:
       Format(instr, "lb        'rd, 'imm12('rs1)");
@@ -1835,7 +1857,6 @@ int Disassembler::InstructionDecode(v8::internal::Vector<char> buffer,
   return d.InstructionDecode(instruction);
 }
 
-// The RISC-V assembler does not currently use constant pools.
 int Disassembler::ConstantPoolSizeAt(byte* instruction) {
   return v8::internal::Assembler::ConstantPoolSizeAt(
       reinterpret_cast<v8::internal::Instruction*>(instruction));
diff --git a/chromium/v8/src/diagnostics/system-jit-metadata-win.h b/chromium/v8/src/diagnostics/system-jit-metadata-win.h
index 37678c25185..84cf184eda3 100644
--- a/chromium/v8/src/diagnostics/system-jit-metadata-win.h
+++ b/chromium/v8/src/diagnostics/system-jit-metadata-win.h
@@ -6,6 +6,9 @@
 #define V8_DIAGNOSTICS_SYSTEM_JIT_METADATA_WIN_H_
 
 #include <Windows.h>
+#ifndef VOID
+#define VOID void
+#endif
 #include <TraceLoggingProvider.h>
 #include <evntprov.h>
 #include <evntrace.h>  // defines TRACE_LEVEL_* and EVENT_TRACE_TYPE_*
diff --git a/chromium/v8/src/diagnostics/system-jit-win.cc b/chromium/v8/src/diagnostics/system-jit-win.cc
index 49200219c26..a4c4237c160 100644
--- a/chromium/v8/src/diagnostics/system-jit-win.cc
+++ b/chromium/v8/src/diagnostics/system-jit-win.cc
@@ -9,6 +9,10 @@
 #include "src/diagnostics/system-jit-metadata-win.h"
 #include "src/libplatform/tracing/recorder.h"
 
+#if !defined(V8_ENABLE_SYSTEM_INSTRUMENTATION)
+#error "This file is only compiled if v8_enable_system_instrumentation"
+#endif
+
 #if defined(__clang__)
 #pragma clang diagnostic ignored "-Wc++98-compat-extra-semi"
 #endif
diff --git a/chromium/v8/src/diagnostics/unwinding-info-win64.cc b/chromium/v8/src/diagnostics/unwinding-info-win64.cc
index 9a5f7069e75..6127c0a7867 100644
--- a/chromium/v8/src/diagnostics/unwinding-info-win64.cc
+++ b/chromium/v8/src/diagnostics/unwinding-info-win64.cc
@@ -464,24 +464,27 @@ static decltype(
     &::RtlDeleteGrowableFunctionTable) delete_growable_function_table_func =
     nullptr;
 
+void LoadNtdllUnwindingFunctionsOnce() {
+  // Load functions from the ntdll.dll module.
+  HMODULE ntdll_module =
+      LoadLibraryEx(L"ntdll.dll", nullptr, LOAD_LIBRARY_SEARCH_SYSTEM32);
+  DCHECK_NOT_NULL(ntdll_module);
+
+  // This fails on Windows 7.
+  add_growable_function_table_func =
+      reinterpret_cast<decltype(&::RtlAddGrowableFunctionTable)>(
+          ::GetProcAddress(ntdll_module, "RtlAddGrowableFunctionTable"));
+  DCHECK_IMPLIES(IsWindows8OrGreater(), add_growable_function_table_func);
+
+  delete_growable_function_table_func =
+      reinterpret_cast<decltype(&::RtlDeleteGrowableFunctionTable)>(
+          ::GetProcAddress(ntdll_module, "RtlDeleteGrowableFunctionTable"));
+  DCHECK_IMPLIES(IsWindows8OrGreater(), delete_growable_function_table_func);
+}
+
 void LoadNtdllUnwindingFunctions() {
-  base::CallOnce(&load_ntdll_unwinding_functions_once, []() {
-    // Load functions from the ntdll.dll module.
-    HMODULE ntdll_module =
-        LoadLibraryEx(L"ntdll.dll", nullptr, LOAD_LIBRARY_SEARCH_SYSTEM32);
-    DCHECK_NOT_NULL(ntdll_module);
-
-    // This fails on Windows 7.
-    add_growable_function_table_func =
-        reinterpret_cast<decltype(&::RtlAddGrowableFunctionTable)>(
-            ::GetProcAddress(ntdll_module, "RtlAddGrowableFunctionTable"));
-    DCHECK_IMPLIES(IsWindows8OrGreater(), add_growable_function_table_func);
-
-    delete_growable_function_table_func =
-        reinterpret_cast<decltype(&::RtlDeleteGrowableFunctionTable)>(
-            ::GetProcAddress(ntdll_module, "RtlDeleteGrowableFunctionTable"));
-    DCHECK_IMPLIES(IsWindows8OrGreater(), delete_growable_function_table_func);
-  });
+  base::CallOnce(&load_ntdll_unwinding_functions_once,
+                 &LoadNtdllUnwindingFunctionsOnce);
 }
 
 bool AddGrowableFunctionTable(PVOID* DynamicTable,
@@ -574,6 +577,11 @@ void UnregisterNonABICompliantCodeRange(void* start) {
       ExceptionHandlerRecord* record =
           reinterpret_cast<ExceptionHandlerRecord*>(start);
       CHECK(::RtlDeleteFunctionTable(record->runtime_function));
+
+      // Unprotect reserved page.
+      DWORD old_protect;
+      CHECK(VirtualProtect(start, sizeof(ExceptionHandlerRecord),
+                           PAGE_READWRITE, &old_protect));
     }
 #endif  // V8_OS_WIN_X64
   } else {
@@ -582,6 +590,11 @@ void UnregisterNonABICompliantCodeRange(void* start) {
     if (record->dynamic_table) {
       DeleteGrowableFunctionTable(record->dynamic_table);
     }
+
+    // Unprotect reserved page.
+    DWORD old_protect;
+    CHECK(VirtualProtect(start, sizeof(CodeRangeUnwindingRecord),
+                         PAGE_READWRITE, &old_protect));
   }
 }
 
diff --git a/chromium/v8/src/execution/arguments.h b/chromium/v8/src/execution/arguments.h
index 39877cf4d29..22ce80bb1e3 100644
--- a/chromium/v8/src/execution/arguments.h
+++ b/chromium/v8/src/execution/arguments.h
@@ -107,29 +107,40 @@ double ClobberDoubleRegisters(double x1, double x2, double x3, double x4);
 
 // TODO(cbruni): add global flag to check whether any tracing events have been
 // enabled.
-#define RUNTIME_FUNCTION_RETURNS_TYPE(Type, InternalType, Convert, Name)      \
-  static V8_INLINE InternalType __RT_impl_##Name(RuntimeArguments args,       \
-                                                 Isolate* isolate);           \
-                                                                              \
+#ifdef V8_RUNTIME_CALL_STATS
+#define RUNTIME_ENTRY_WITH_RCS(Type, InternalType, Convert, Name)             \
   V8_NOINLINE static Type Stats_##Name(int args_length, Address* args_object, \
                                        Isolate* isolate) {                    \
-    RuntimeCallTimerScope timer(isolate, RuntimeCallCounterId::k##Name);      \
+    RCS_SCOPE(isolate, RuntimeCallCounterId::k##Name);                        \
     TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.runtime"),                     \
                  "V8.Runtime_" #Name);                                        \
     RuntimeArguments args(args_length, args_object);                          \
     return Convert(__RT_impl_##Name(args, isolate));                          \
-  }                                                                           \
-                                                                              \
-  Type Name(int args_length, Address* args_object, Isolate* isolate) {        \
-    DCHECK(isolate->context().is_null() || isolate->context().IsContext());   \
-    CLOBBER_DOUBLE_REGISTERS();                                               \
-    if (V8_UNLIKELY(TracingFlags::is_runtime_stats_enabled())) {              \
-      return Stats_##Name(args_length, args_object, isolate);                 \
-    }                                                                         \
-    RuntimeArguments args(args_length, args_object);                          \
-    return Convert(__RT_impl_##Name(args, isolate));                          \
-  }                                                                           \
-                                                                              \
+  }
+
+#define TEST_AND_CALL_RCS(Name)                                \
+  if (V8_UNLIKELY(TracingFlags::is_runtime_stats_enabled())) { \
+    return Stats_##Name(args_length, args_object, isolate);    \
+  }
+
+#else  // V8_RUNTIME_CALL_STATS
+#define RUNTIME_ENTRY_WITH_RCS(Type, InternalType, Convert, Name)
+#define TEST_AND_CALL_RCS(Name)
+
+#endif  // V8_RUNTIME_CALL_STATS
+
+#define RUNTIME_FUNCTION_RETURNS_TYPE(Type, InternalType, Convert, Name)    \
+  static V8_INLINE InternalType __RT_impl_##Name(RuntimeArguments args,     \
+                                                 Isolate* isolate);         \
+  RUNTIME_ENTRY_WITH_RCS(Type, InternalType, Convert, Name)                 \
+  Type Name(int args_length, Address* args_object, Isolate* isolate) {      \
+    DCHECK(isolate->context().is_null() || isolate->context().IsContext()); \
+    CLOBBER_DOUBLE_REGISTERS();                                             \
+    TEST_AND_CALL_RCS(Name)                                                 \
+    RuntimeArguments args(args_length, args_object);                        \
+    return Convert(__RT_impl_##Name(args, isolate));                        \
+  }                                                                         \
+                                                                            \
   static InternalType __RT_impl_##Name(RuntimeArguments args, Isolate* isolate)
 
 #define CONVERT_OBJECT(x) (x).ptr()
diff --git a/chromium/v8/src/execution/arm/simulator-arm.cc b/chromium/v8/src/execution/arm/simulator-arm.cc
index ee4e9af4621..ca7d709fbb7 100644
--- a/chromium/v8/src/execution/arm/simulator-arm.cc
+++ b/chromium/v8/src/execution/arm/simulator-arm.cc
@@ -42,7 +42,7 @@ DEFINE_LAZY_LEAKY_OBJECT_GETTER(Simulator::GlobalMonitor,
 // SScanF not being implemented in a platform independent way through
 // ::v8::internal::OS in the same way as SNPrintF is that the
 // Windows C Run-Time Library does not provide vsscanf.
-#define SScanF sscanf  // NOLINT
+#define SScanF sscanf
 
 // The ArmDebugger class is used by the simulator while debugging simulated ARM
 // code.
@@ -50,6 +50,7 @@ class ArmDebugger {
  public:
   explicit ArmDebugger(Simulator* sim) : sim_(sim) {}
   void Debug();
+  bool ExecDebugCommand(ArrayUniquePtr<char> line_ptr);
 
  private:
   static const Instr kBreakpointInstr =
@@ -191,6 +192,31 @@ void ArmDebugger::Debug() {
   intptr_t last_pc = -1;
   bool done = false;
 
+  // Unset breakpoint while running in the debugger shell, making it invisible
+  // to all commands.
+  UndoBreakpoint();
+
+  while (!done && !sim_->has_bad_pc()) {
+    if (last_pc != sim_->get_pc()) {
+      disasm::NameConverter converter;
+      disasm::Disassembler dasm(converter);
+      // use a reasonably large buffer
+      v8::internal::EmbeddedVector<char, 256> buffer;
+      dasm.InstructionDecode(buffer, reinterpret_cast<byte*>(sim_->get_pc()));
+      PrintF("  0x%08x  %s\n", sim_->get_pc(), buffer.begin());
+      last_pc = sim_->get_pc();
+    }
+    ArrayUniquePtr<char> line(ReadLine("sim> "));
+
+    done = ExecDebugCommand(std::move(line));
+  }
+
+  // Reinstall breakpoint to stop execution and enter the debugger shell when
+  // hit.
+  RedoBreakpoint();
+}
+
+bool ArmDebugger::ExecDebugCommand(ArrayUniquePtr<char> line_ptr) {
 #define COMMAND_SIZE 63
 #define ARG_SIZE 255
 
@@ -207,352 +233,357 @@ void ArmDebugger::Debug() {
   arg1[ARG_SIZE] = 0;
   arg2[ARG_SIZE] = 0;
 
-  // Unset breakpoint while running in the debugger shell, making it invisible
-  // to all commands.
-  UndoBreakpoint();
+  if (line_ptr == nullptr) return true;
 
-  while (!done && !sim_->has_bad_pc()) {
-    if (last_pc != sim_->get_pc()) {
-      disasm::NameConverter converter;
-      disasm::Disassembler dasm(converter);
-      // use a reasonably large buffer
-      v8::internal::EmbeddedVector<char, 256> buffer;
-      dasm.InstructionDecode(buffer, reinterpret_cast<byte*>(sim_->get_pc()));
-      PrintF("  0x%08x  %s\n", sim_->get_pc(), buffer.begin());
-      last_pc = sim_->get_pc();
-    }
-    char* line = ReadLine("sim> ");
-    if (line == nullptr) {
-      break;
-    } else {
-      char* last_input = sim_->last_debugger_input();
-      if (strcmp(line, "\n") == 0 && last_input != nullptr) {
-        line = last_input;
-      } else {
-        // Ownership is transferred to sim_;
-        sim_->set_last_debugger_input(line);
-      }
-      // Use sscanf to parse the individual parts of the command line. At the
-      // moment no command expects more than two parameters.
-      int argc = SScanF(line,
-                        "%" XSTR(COMMAND_SIZE) "s "
-                        "%" XSTR(ARG_SIZE) "s "
-                        "%" XSTR(ARG_SIZE) "s",
-                        cmd, arg1, arg2);
-      if ((strcmp(cmd, "si") == 0) || (strcmp(cmd, "stepi") == 0)) {
-        sim_->InstructionDecode(reinterpret_cast<Instruction*>(sim_->get_pc()));
-      } else if ((strcmp(cmd, "c") == 0) || (strcmp(cmd, "cont") == 0)) {
-        // Execute the one instruction we broke at with breakpoints disabled.
-        sim_->InstructionDecode(reinterpret_cast<Instruction*>(sim_->get_pc()));
-        // Leave the debugger shell.
-        done = true;
-      } else if ((strcmp(cmd, "p") == 0) || (strcmp(cmd, "print") == 0)) {
-        if (argc == 2 || (argc == 3 && strcmp(arg2, "fp") == 0)) {
-          int32_t value;
-          float svalue;
-          double dvalue;
-          if (strcmp(arg1, "all") == 0) {
-            for (int i = 0; i < kNumRegisters; i++) {
-              value = GetRegisterValue(i);
-              PrintF("%3s: 0x%08x %10d", RegisterName(Register::from_code(i)),
-                     value, value);
-              if ((argc == 3 && strcmp(arg2, "fp") == 0) && i < 8 &&
-                  (i % 2) == 0) {
-                dvalue = GetRegisterPairDoubleValue(i);
-                PrintF(" (%f)\n", dvalue);
-              } else {
-                PrintF("\n");
-              }
-            }
-            for (int i = 0; i < DwVfpRegister::SupportedRegisterCount(); i++) {
-              dvalue = GetVFPDoubleRegisterValue(i);
-              uint64_t as_words = bit_cast<uint64_t>(dvalue);
-              PrintF("%3s: %f 0x%08x %08x\n", VFPRegisters::Name(i, true),
-                     dvalue, static_cast<uint32_t>(as_words >> 32),
-                     static_cast<uint32_t>(as_words & 0xFFFFFFFF));
-            }
+  // Repeat last command by default.
+  const char* line = line_ptr.get();
+  const char* last_input = sim_->last_debugger_input();
+  if (strcmp(line, "\n") == 0 && (last_input != nullptr)) {
+    line_ptr.reset();
+    line = last_input;
+  } else {
+    // Update the latest command ran
+    sim_->set_last_debugger_input(std::move(line_ptr));
+  }
+
+  // Use sscanf to parse the individual parts of the command line. At the
+  // moment no command expects more than two parameters.
+  int argc = SScanF(line,
+                      "%" XSTR(COMMAND_SIZE) "s "
+                      "%" XSTR(ARG_SIZE) "s "
+                      "%" XSTR(ARG_SIZE) "s",
+                      cmd, arg1, arg2);
+  if ((strcmp(cmd, "si") == 0) || (strcmp(cmd, "stepi") == 0)) {
+    sim_->InstructionDecode(reinterpret_cast<Instruction*>(sim_->get_pc()));
+  } else if ((strcmp(cmd, "c") == 0) || (strcmp(cmd, "cont") == 0)) {
+    // Execute the one instruction we broke at with breakpoints disabled.
+    sim_->InstructionDecode(reinterpret_cast<Instruction*>(sim_->get_pc()));
+    // Leave the debugger shell.
+    return true;
+  } else if ((strcmp(cmd, "p") == 0) || (strcmp(cmd, "print") == 0)) {
+    if (argc == 2 || (argc == 3 && strcmp(arg2, "fp") == 0)) {
+      int32_t value;
+      float svalue;
+      double dvalue;
+      if (strcmp(arg1, "all") == 0) {
+        for (int i = 0; i < kNumRegisters; i++) {
+          value = GetRegisterValue(i);
+          PrintF("%3s: 0x%08x %10d", RegisterName(Register::from_code(i)),
+                 value, value);
+          if ((argc == 3 && strcmp(arg2, "fp") == 0) && i < 8 && (i % 2) == 0) {
+            dvalue = GetRegisterPairDoubleValue(i);
+            PrintF(" (%f)\n", dvalue);
           } else {
-            if (GetValue(arg1, &value)) {
-              PrintF("%s: 0x%08x %d \n", arg1, value, value);
-            } else if (GetVFPSingleValue(arg1, &svalue)) {
-              uint32_t as_word = bit_cast<uint32_t>(svalue);
-              PrintF("%s: %f 0x%08x\n", arg1, svalue, as_word);
-            } else if (GetVFPDoubleValue(arg1, &dvalue)) {
-              uint64_t as_words = bit_cast<uint64_t>(dvalue);
-              PrintF("%s: %f 0x%08x %08x\n", arg1, dvalue,
-                     static_cast<uint32_t>(as_words >> 32),
-                     static_cast<uint32_t>(as_words & 0xFFFFFFFF));
-            } else {
-              PrintF("%s unrecognized\n", arg1);
-            }
+            PrintF("\n");
           }
+        }
+        for (int i = 0; i < DwVfpRegister::SupportedRegisterCount(); i++) {
+          dvalue = GetVFPDoubleRegisterValue(i);
+          uint64_t as_words = bit_cast<uint64_t>(dvalue);
+          PrintF("%3s: %f 0x%08x %08x\n", VFPRegisters::Name(i, true), dvalue,
+                 static_cast<uint32_t>(as_words >> 32),
+                 static_cast<uint32_t>(as_words & 0xFFFFFFFF));
+        }
+      } else {
+        if (GetValue(arg1, &value)) {
+          PrintF("%s: 0x%08x %d \n", arg1, value, value);
+        } else if (GetVFPSingleValue(arg1, &svalue)) {
+          uint32_t as_word = bit_cast<uint32_t>(svalue);
+          PrintF("%s: %f 0x%08x\n", arg1, svalue, as_word);
+        } else if (GetVFPDoubleValue(arg1, &dvalue)) {
+          uint64_t as_words = bit_cast<uint64_t>(dvalue);
+          PrintF("%s: %f 0x%08x %08x\n", arg1, dvalue,
+                 static_cast<uint32_t>(as_words >> 32),
+                 static_cast<uint32_t>(as_words & 0xFFFFFFFF));
         } else {
-          PrintF("print <register>\n");
+          PrintF("%s unrecognized\n", arg1);
         }
-      } else if ((strcmp(cmd, "po") == 0) ||
-                 (strcmp(cmd, "printobject") == 0)) {
-        if (argc == 2) {
-          int32_t value;
-          StdoutStream os;
-          if (GetValue(arg1, &value)) {
-            Object obj(value);
-            os << arg1 << ": \n";
+      }
+    } else {
+      PrintF("print <register>\n");
+    }
+  } else if ((strcmp(cmd, "po") == 0) || (strcmp(cmd, "printobject") == 0)) {
+    if (argc == 2) {
+      int32_t value;
+      StdoutStream os;
+      if (GetValue(arg1, &value)) {
+        Object obj(value);
+        os << arg1 << ": \n";
 #ifdef DEBUG
-            obj.Print(os);
-            os << "\n";
+        obj.Print(os);
+        os << "\n";
 #else
-            os << Brief(obj) << "\n";
+        os << Brief(obj) << "\n";
 #endif
+      } else {
+        os << arg1 << " unrecognized\n";
+      }
+    } else {
+      PrintF("printobject <value>\n");
+    }
+  } else if (strcmp(cmd, "stack") == 0 || strcmp(cmd, "mem") == 0 ||
+             strcmp(cmd, "dump") == 0) {
+    int32_t* cur = nullptr;
+    int32_t* end = nullptr;
+    int next_arg = 1;
+
+    if (strcmp(cmd, "stack") == 0) {
+      cur = reinterpret_cast<int32_t*>(sim_->get_register(Simulator::sp));
+    } else {  // "mem"
+      int32_t value;
+      if (!GetValue(arg1, &value)) {
+        PrintF("%s unrecognized\n", arg1);
+        return false;
+      }
+      cur = reinterpret_cast<int32_t*>(value);
+      next_arg++;
+    }
+
+    int32_t words;
+    if (argc == next_arg) {
+      words = 10;
+    } else {
+      if (!GetValue(argv[next_arg], &words)) {
+        words = 10;
+      }
+    }
+    end = cur + words;
+
+    bool skip_obj_print = (strcmp(cmd, "dump") == 0);
+    while (cur < end) {
+      PrintF("  0x%08" V8PRIxPTR ":  0x%08x %10d",
+             reinterpret_cast<intptr_t>(cur), *cur, *cur);
+      Object obj(*cur);
+      Heap* current_heap = sim_->isolate_->heap();
+      if (!skip_obj_print) {
+        if (obj.IsSmi() ||
+            IsValidHeapObject(current_heap, HeapObject::cast(obj))) {
+          PrintF(" (");
+          if (obj.IsSmi()) {
+            PrintF("smi %d", Smi::ToInt(obj));
           } else {
-            os << arg1 << " unrecognized\n";
-          }
-        } else {
-          PrintF("printobject <value>\n");
-        }
-      } else if (strcmp(cmd, "stack") == 0 || strcmp(cmd, "mem") == 0 ||
-                 strcmp(cmd, "dump") == 0) {
-        int32_t* cur = nullptr;
-        int32_t* end = nullptr;
-        int next_arg = 1;
-
-        if (strcmp(cmd, "stack") == 0) {
-          cur = reinterpret_cast<int32_t*>(sim_->get_register(Simulator::sp));
-        } else {  // "mem"
-          int32_t value;
-          if (!GetValue(arg1, &value)) {
-            PrintF("%s unrecognized\n", arg1);
-            continue;
+            obj.ShortPrint();
           }
-          cur = reinterpret_cast<int32_t*>(value);
-          next_arg++;
+          PrintF(")");
         }
+      }
+      PrintF("\n");
+      cur++;
+    }
+  } else if (strcmp(cmd, "disasm") == 0 || strcmp(cmd, "di") == 0) {
+    disasm::NameConverter converter;
+    disasm::Disassembler dasm(converter);
+    // use a reasonably large buffer
+    v8::internal::EmbeddedVector<char, 256> buffer;
 
-        int32_t words;
-        if (argc == next_arg) {
-          words = 10;
-        } else {
-          if (!GetValue(argv[next_arg], &words)) {
-            words = 10;
-          }
+    byte* prev = nullptr;
+    byte* cur = nullptr;
+    byte* end = nullptr;
+
+    if (argc == 1) {
+      cur = reinterpret_cast<byte*>(sim_->get_pc());
+      end = cur + (10 * kInstrSize);
+    } else if (argc == 2) {
+      int regnum = Registers::Number(arg1);
+      if (regnum != kNoRegister || strncmp(arg1, "0x", 2) == 0) {
+        // The argument is an address or a register name.
+        int32_t value;
+        if (GetValue(arg1, &value)) {
+          cur = reinterpret_cast<byte*>(value);
+          // Disassemble 10 instructions at <arg1>.
+          end = cur + (10 * kInstrSize);
         }
-        end = cur + words;
-
-        bool skip_obj_print = (strcmp(cmd, "dump") == 0);
-        while (cur < end) {
-          PrintF("  0x%08" V8PRIxPTR ":  0x%08x %10d",
-                 reinterpret_cast<intptr_t>(cur), *cur, *cur);
-          Object obj(*cur);
-          Heap* current_heap = sim_->isolate_->heap();
-          if (!skip_obj_print) {
-            if (obj.IsSmi() ||
-                IsValidHeapObject(current_heap, HeapObject::cast(obj))) {
-              PrintF(" (");
-              if (obj.IsSmi()) {
-                PrintF("smi %d", Smi::ToInt(obj));
-              } else {
-                obj.ShortPrint();
-              }
-              PrintF(")");
-            }
-          }
-          PrintF("\n");
-          cur++;
+      } else {
+        // The argument is the number of instructions.
+        int32_t value;
+        if (GetValue(arg1, &value)) {
+          cur = reinterpret_cast<byte*>(sim_->get_pc());
+          // Disassemble <arg1> instructions.
+          end = cur + (value * kInstrSize);
         }
-      } else if (strcmp(cmd, "disasm") == 0 || strcmp(cmd, "di") == 0) {
-        disasm::NameConverter converter;
-        disasm::Disassembler dasm(converter);
-        // use a reasonably large buffer
-        v8::internal::EmbeddedVector<char, 256> buffer;
+      }
+    } else {
+      int32_t value1;
+      int32_t value2;
+      if (GetValue(arg1, &value1) && GetValue(arg2, &value2)) {
+        cur = reinterpret_cast<byte*>(value1);
+        end = cur + (value2 * kInstrSize);
+      }
+    }
 
-        byte* prev = nullptr;
-        byte* cur = nullptr;
-        byte* end = nullptr;
+    while (cur < end) {
+      prev = cur;
+      cur += dasm.InstructionDecode(buffer, cur);
+      PrintF("  0x%08" V8PRIxPTR "  %s\n", reinterpret_cast<intptr_t>(prev),
+             buffer.begin());
+    }
+  } else if (strcmp(cmd, "gdb") == 0) {
+    PrintF("relinquishing control to gdb\n");
+    v8::base::OS::DebugBreak();
+    PrintF("regaining control from gdb\n");
+  } else if (strcmp(cmd, "break") == 0) {
+    if (argc == 2) {
+      int32_t value;
+      if (GetValue(arg1, &value)) {
+        if (!SetBreakpoint(reinterpret_cast<Instruction*>(value))) {
+          PrintF("setting breakpoint failed\n");
+        }
+      } else {
+        PrintF("%s unrecognized\n", arg1);
+      }
+    } else {
+      PrintF("break <address>\n");
+    }
+  } else if (strcmp(cmd, "backtrace") == 0 || strcmp(cmd, "bt") == 0) {
+    int32_t pc = sim_->get_pc();
+    int32_t lr = sim_->get_register(Simulator::lr);
+    int32_t sp = sim_->get_register(Simulator::sp);
+    int32_t fp = sim_->get_register(Simulator::fp);
 
-        if (argc == 1) {
-          cur = reinterpret_cast<byte*>(sim_->get_pc());
-          end = cur + (10 * kInstrSize);
-        } else if (argc == 2) {
-          int regnum = Registers::Number(arg1);
-          if (regnum != kNoRegister || strncmp(arg1, "0x", 2) == 0) {
-            // The argument is an address or a register name.
-            int32_t value;
-            if (GetValue(arg1, &value)) {
-              cur = reinterpret_cast<byte*>(value);
-              // Disassemble 10 instructions at <arg1>.
-              end = cur + (10 * kInstrSize);
-            }
-          } else {
-            // The argument is the number of instructions.
-            int32_t value;
-            if (GetValue(arg1, &value)) {
-              cur = reinterpret_cast<byte*>(sim_->get_pc());
-              // Disassemble <arg1> instructions.
-              end = cur + (value * kInstrSize);
-            }
+    int i = 0;
+    while (true) {
+      PrintF("#%d: 0x%08x (sp=0x%08x, fp=0x%08x)\n", i, pc, sp, fp);
+      pc = lr;
+      sp = fp;
+      if (pc == Simulator::end_sim_pc) {
+        break;
+      }
+      lr = *(reinterpret_cast<int32_t*>(fp) + 1);
+      fp = *reinterpret_cast<int32_t*>(fp);
+      i++;
+      if (i > 100) {
+        PrintF("Too many frames\n");
+        break;
+      }
+    }
+  } else if (strcmp(cmd, "del") == 0) {
+    DeleteBreakpoint();
+  } else if (strcmp(cmd, "flags") == 0) {
+    PrintF("N flag: %d; ", sim_->n_flag_);
+    PrintF("Z flag: %d; ", sim_->z_flag_);
+    PrintF("C flag: %d; ", sim_->c_flag_);
+    PrintF("V flag: %d\n", sim_->v_flag_);
+    PrintF("INVALID OP flag: %d; ", sim_->inv_op_vfp_flag_);
+    PrintF("DIV BY ZERO flag: %d; ", sim_->div_zero_vfp_flag_);
+    PrintF("OVERFLOW flag: %d; ", sim_->overflow_vfp_flag_);
+    PrintF("UNDERFLOW flag: %d; ", sim_->underflow_vfp_flag_);
+    PrintF("INEXACT flag: %d;\n", sim_->inexact_vfp_flag_);
+  } else if (strcmp(cmd, "stop") == 0) {
+    int32_t value;
+    intptr_t stop_pc = sim_->get_pc() - kInstrSize;
+    Instruction* stop_instr = reinterpret_cast<Instruction*>(stop_pc);
+    if ((argc == 2) && (strcmp(arg1, "unstop") == 0)) {
+      // Remove the current stop.
+      if (stop_instr->IsStop()) {
+        SetInstructionBitsInCodeSpace(stop_instr, kNopInstr,
+                                      sim_->isolate_->heap());
+      } else {
+        PrintF("Not at debugger stop.\n");
+      }
+    } else if (argc == 3) {
+      // Print information about all/the specified breakpoint(s).
+      if (strcmp(arg1, "info") == 0) {
+        if (strcmp(arg2, "all") == 0) {
+          PrintF("Stop information:\n");
+          for (uint32_t i = 0; i < sim_->kNumOfWatchedStops; i++) {
+            sim_->PrintStopInfo(i);
           }
+        } else if (GetValue(arg2, &value)) {
+          sim_->PrintStopInfo(value);
         } else {
-          int32_t value1;
-          int32_t value2;
-          if (GetValue(arg1, &value1) && GetValue(arg2, &value2)) {
-            cur = reinterpret_cast<byte*>(value1);
-            end = cur + (value2 * kInstrSize);
-          }
+          PrintF("Unrecognized argument.\n");
         }
-
-        while (cur < end) {
-          prev = cur;
-          cur += dasm.InstructionDecode(buffer, cur);
-          PrintF("  0x%08" V8PRIxPTR "  %s\n", reinterpret_cast<intptr_t>(prev),
-                 buffer.begin());
-        }
-      } else if (strcmp(cmd, "gdb") == 0) {
-        PrintF("relinquishing control to gdb\n");
-        v8::base::OS::DebugBreak();
-        PrintF("regaining control from gdb\n");
-      } else if (strcmp(cmd, "break") == 0) {
-        if (argc == 2) {
-          int32_t value;
-          if (GetValue(arg1, &value)) {
-            if (!SetBreakpoint(reinterpret_cast<Instruction*>(value))) {
-              PrintF("setting breakpoint failed\n");
-            }
-          } else {
-            PrintF("%s unrecognized\n", arg1);
+      } else if (strcmp(arg1, "enable") == 0) {
+        // Enable all/the specified breakpoint(s).
+        if (strcmp(arg2, "all") == 0) {
+          for (uint32_t i = 0; i < sim_->kNumOfWatchedStops; i++) {
+            sim_->EnableStop(i);
           }
+        } else if (GetValue(arg2, &value)) {
+          sim_->EnableStop(value);
         } else {
-          PrintF("break <address>\n");
+          PrintF("Unrecognized argument.\n");
         }
-      } else if (strcmp(cmd, "del") == 0) {
-        DeleteBreakpoint();
-      } else if (strcmp(cmd, "flags") == 0) {
-        PrintF("N flag: %d; ", sim_->n_flag_);
-        PrintF("Z flag: %d; ", sim_->z_flag_);
-        PrintF("C flag: %d; ", sim_->c_flag_);
-        PrintF("V flag: %d\n", sim_->v_flag_);
-        PrintF("INVALID OP flag: %d; ", sim_->inv_op_vfp_flag_);
-        PrintF("DIV BY ZERO flag: %d; ", sim_->div_zero_vfp_flag_);
-        PrintF("OVERFLOW flag: %d; ", sim_->overflow_vfp_flag_);
-        PrintF("UNDERFLOW flag: %d; ", sim_->underflow_vfp_flag_);
-        PrintF("INEXACT flag: %d;\n", sim_->inexact_vfp_flag_);
-      } else if (strcmp(cmd, "stop") == 0) {
-        int32_t value;
-        intptr_t stop_pc = sim_->get_pc() - kInstrSize;
-        Instruction* stop_instr = reinterpret_cast<Instruction*>(stop_pc);
-        if ((argc == 2) && (strcmp(arg1, "unstop") == 0)) {
-          // Remove the current stop.
-          if (stop_instr->IsStop()) {
-            SetInstructionBitsInCodeSpace(stop_instr, kNopInstr,
-                                          sim_->isolate_->heap());
-          } else {
-            PrintF("Not at debugger stop.\n");
-          }
-        } else if (argc == 3) {
-          // Print information about all/the specified breakpoint(s).
-          if (strcmp(arg1, "info") == 0) {
-            if (strcmp(arg2, "all") == 0) {
-              PrintF("Stop information:\n");
-              for (uint32_t i = 0; i < sim_->kNumOfWatchedStops; i++) {
-                sim_->PrintStopInfo(i);
-              }
-            } else if (GetValue(arg2, &value)) {
-              sim_->PrintStopInfo(value);
-            } else {
-              PrintF("Unrecognized argument.\n");
-            }
-          } else if (strcmp(arg1, "enable") == 0) {
-            // Enable all/the specified breakpoint(s).
-            if (strcmp(arg2, "all") == 0) {
-              for (uint32_t i = 0; i < sim_->kNumOfWatchedStops; i++) {
-                sim_->EnableStop(i);
-              }
-            } else if (GetValue(arg2, &value)) {
-              sim_->EnableStop(value);
-            } else {
-              PrintF("Unrecognized argument.\n");
-            }
-          } else if (strcmp(arg1, "disable") == 0) {
-            // Disable all/the specified breakpoint(s).
-            if (strcmp(arg2, "all") == 0) {
-              for (uint32_t i = 0; i < sim_->kNumOfWatchedStops; i++) {
-                sim_->DisableStop(i);
-              }
-            } else if (GetValue(arg2, &value)) {
-              sim_->DisableStop(value);
-            } else {
-              PrintF("Unrecognized argument.\n");
-            }
+      } else if (strcmp(arg1, "disable") == 0) {
+        // Disable all/the specified breakpoint(s).
+        if (strcmp(arg2, "all") == 0) {
+          for (uint32_t i = 0; i < sim_->kNumOfWatchedStops; i++) {
+            sim_->DisableStop(i);
           }
+        } else if (GetValue(arg2, &value)) {
+          sim_->DisableStop(value);
         } else {
-          PrintF("Wrong usage. Use help command for more information.\n");
+          PrintF("Unrecognized argument.\n");
         }
-      } else if ((strcmp(cmd, "t") == 0) || strcmp(cmd, "trace") == 0) {
-        ::v8::internal::FLAG_trace_sim = !::v8::internal::FLAG_trace_sim;
-        PrintF("Trace of executed instructions is %s\n",
-               ::v8::internal::FLAG_trace_sim ? "on" : "off");
-      } else if ((strcmp(cmd, "h") == 0) || (strcmp(cmd, "help") == 0)) {
-        PrintF("cont\n");
-        PrintF("  continue execution (alias 'c')\n");
-        PrintF("stepi\n");
-        PrintF("  step one instruction (alias 'si')\n");
-        PrintF("print <register>\n");
-        PrintF("  print register content (alias 'p')\n");
-        PrintF("  use register name 'all' to print all registers\n");
-        PrintF("  add argument 'fp' to print register pair double values\n");
-        PrintF("printobject <register>\n");
-        PrintF("  print an object from a register (alias 'po')\n");
-        PrintF("flags\n");
-        PrintF("  print flags\n");
-        PrintF("stack [<words>]\n");
-        PrintF("  dump stack content, default dump 10 words)\n");
-        PrintF("mem <address> [<words>]\n");
-        PrintF("  dump memory content, default dump 10 words)\n");
-        PrintF("dump [<words>]\n");
-        PrintF(
-            "  dump memory content without pretty printing JS objects, default "
-            "dump 10 words)\n");
-        PrintF("disasm [<instructions>]\n");
-        PrintF("disasm [<address/register>]\n");
-        PrintF("disasm [[<address/register>] <instructions>]\n");
-        PrintF("  disassemble code, default is 10 instructions\n");
-        PrintF("  from pc (alias 'di')\n");
-        PrintF("gdb\n");
-        PrintF("  enter gdb\n");
-        PrintF("break <address>\n");
-        PrintF("  set a break point on the address\n");
-        PrintF("del\n");
-        PrintF("  delete the breakpoint\n");
-        PrintF("trace (alias 't')\n");
-        PrintF("  toogle the tracing of all executed statements\n");
-        PrintF("stop feature:\n");
-        PrintF("  Description:\n");
-        PrintF("    Stops are debug instructions inserted by\n");
-        PrintF("    the Assembler::stop() function.\n");
-        PrintF("    When hitting a stop, the Simulator will\n");
-        PrintF("    stop and give control to the ArmDebugger.\n");
-        PrintF("    The first %d stop codes are watched:\n",
-               Simulator::kNumOfWatchedStops);
-        PrintF("    - They can be enabled / disabled: the Simulator\n");
-        PrintF("      will / won't stop when hitting them.\n");
-        PrintF("    - The Simulator keeps track of how many times they \n");
-        PrintF("      are met. (See the info command.) Going over a\n");
-        PrintF("      disabled stop still increases its counter. \n");
-        PrintF("  Commands:\n");
-        PrintF("    stop info all/<code> : print infos about number <code>\n");
-        PrintF("      or all stop(s).\n");
-        PrintF("    stop enable/disable all/<code> : enables / disables\n");
-        PrintF("      all or number <code> stop(s)\n");
-        PrintF("    stop unstop\n");
-        PrintF("      ignore the stop instruction at the current location\n");
-        PrintF("      from now on\n");
-      } else {
-        PrintF("Unknown command: %s\n", cmd);
       }
+    } else {
+      PrintF("Wrong usage. Use help command for more information.\n");
     }
+  } else if ((strcmp(cmd, "t") == 0) || strcmp(cmd, "trace") == 0) {
+    ::v8::internal::FLAG_trace_sim = !::v8::internal::FLAG_trace_sim;
+    PrintF("Trace of executed instructions is %s\n",
+           ::v8::internal::FLAG_trace_sim ? "on" : "off");
+  } else if ((strcmp(cmd, "h") == 0) || (strcmp(cmd, "help") == 0)) {
+    PrintF("cont\n");
+    PrintF("  continue execution (alias 'c')\n");
+    PrintF("stepi\n");
+    PrintF("  step one instruction (alias 'si')\n");
+    PrintF("print <register>\n");
+    PrintF("  print register content (alias 'p')\n");
+    PrintF("  use register name 'all' to print all registers\n");
+    PrintF("  add argument 'fp' to print register pair double values\n");
+    PrintF("printobject <register>\n");
+    PrintF("  print an object from a register (alias 'po')\n");
+    PrintF("flags\n");
+    PrintF("  print flags\n");
+    PrintF("stack [<words>]\n");
+    PrintF("  dump stack content, default dump 10 words)\n");
+    PrintF("mem <address> [<words>]\n");
+    PrintF("  dump memory content, default dump 10 words)\n");
+    PrintF("dump [<words>]\n");
+    PrintF(
+        "  dump memory content without pretty printing JS objects, default "
+        "dump 10 words)\n");
+    PrintF("disasm [<instructions>]\n");
+    PrintF("disasm [<address/register>]\n");
+    PrintF("disasm [[<address/register>] <instructions>]\n");
+    PrintF("  disassemble code, default is 10 instructions\n");
+    PrintF("  from pc (alias 'di')\n");
+    PrintF("gdb\n");
+    PrintF("  enter gdb\n");
+    PrintF("break <address>\n");
+    PrintF("  set a break point on the address\n");
+    PrintF("backtrace / bt\n");
+    PrintF("  Walk the frame pointers, dumping the pc/sp/fp for each frame.\n");
+    PrintF("del\n");
+    PrintF("  delete the breakpoint\n");
+    PrintF("trace (alias 't')\n");
+    PrintF("  toogle the tracing of all executed statements\n");
+    PrintF("stop feature:\n");
+    PrintF("  Description:\n");
+    PrintF("    Stops are debug instructions inserted by\n");
+    PrintF("    the Assembler::stop() function.\n");
+    PrintF("    When hitting a stop, the Simulator will\n");
+    PrintF("    stop and give control to the ArmDebugger.\n");
+    PrintF("    The first %d stop codes are watched:\n",
+           Simulator::kNumOfWatchedStops);
+    PrintF("    - They can be enabled / disabled: the Simulator\n");
+    PrintF("      will / won't stop when hitting them.\n");
+    PrintF("    - The Simulator keeps track of how many times they \n");
+    PrintF("      are met. (See the info command.) Going over a\n");
+    PrintF("      disabled stop still increases its counter. \n");
+    PrintF("  Commands:\n");
+    PrintF("    stop info all/<code> : print infos about number <code>\n");
+    PrintF("      or all stop(s).\n");
+    PrintF("    stop enable/disable all/<code> : enables / disables\n");
+    PrintF("      all or number <code> stop(s)\n");
+    PrintF("    stop unstop\n");
+    PrintF("      ignore the stop instruction at the current location\n");
+    PrintF("      from now on\n");
+  } else {
+    PrintF("Unknown command: %s\n", cmd);
   }
-
-  // Reinstall breakpoint to stop execution and enter the debugger shell when
-  // hit.
-  RedoBreakpoint();
+  return false;
 
 #undef COMMAND_SIZE
 #undef ARG_SIZE
@@ -577,11 +608,6 @@ static bool AllOnOnePage(uintptr_t start, int size) {
   return start_page == end_page;
 }
 
-void Simulator::set_last_debugger_input(char* input) {
-  DeleteArray(last_debugger_input_);
-  last_debugger_input_ = input;
-}
-
 void Simulator::SetRedirectInstruction(Instruction* instruction) {
   instruction->SetInstructionBits(al | (0xF * B24) | kCallRtRedirected);
 }
@@ -6499,4 +6525,26 @@ void Simulator::GlobalMonitor::RemoveProcessor(Processor* processor) {
 }  // namespace internal
 }  // namespace v8
 
+//
+// The following functions are used by our gdb macros.
+//
+V8_EXPORT_PRIVATE extern bool _v8_internal_Simulator_ExecDebugCommand(
+    const char* command) {
+  i::Isolate* isolate = i::Isolate::Current();
+  if (!isolate) {
+    fprintf(stderr, "No V8 Isolate found\n");
+    return false;
+  }
+  i::Simulator* simulator = i::Simulator::current(isolate);
+  if (!simulator) {
+    fprintf(stderr, "No Arm simulator found\n");
+    return false;
+  }
+  // Copy the command so that the simulator can take ownership of it.
+  size_t len = strlen(command);
+  i::ArrayUniquePtr<char> command_copy(i::NewArray<char>(len + 1));
+  i::MemCopy(command_copy.get(), command, len + 1);
+  return i::ArmDebugger(simulator).ExecDebugCommand(std::move(command_copy));
+}
+
 #endif  // USE_SIMULATOR
diff --git a/chromium/v8/src/execution/arm/simulator-arm.h b/chromium/v8/src/execution/arm/simulator-arm.h
index a4570ff47df..28cf72591ca 100644
--- a/chromium/v8/src/execution/arm/simulator-arm.h
+++ b/chromium/v8/src/execution/arm/simulator-arm.h
@@ -77,6 +77,7 @@ class Simulator : public SimulatorBase {
     r14,
     r15,
     num_registers,
+    fp = 11,
     sp = 13,
     lr = 14,
     pc = 15,
@@ -255,8 +256,10 @@ class Simulator : public SimulatorBase {
   uintptr_t PopAddress();
 
   // Debugger input.
-  void set_last_debugger_input(char* input);
-  char* last_debugger_input() { return last_debugger_input_; }
+  void set_last_debugger_input(ArrayUniquePtr<char> input) {
+    last_debugger_input_ = std::move(input);
+  }
+  const char* last_debugger_input() { return last_debugger_input_.get(); }
 
   // Redirection support.
   static void SetRedirectInstruction(Instruction* instruction);
@@ -468,7 +471,7 @@ class Simulator : public SimulatorBase {
   int icount_;
 
   // Debugger input.
-  char* last_debugger_input_;
+  ArrayUniquePtr<char> last_debugger_input_;
 
   // Registered breakpoints.
   Instruction* break_pc_;
diff --git a/chromium/v8/src/execution/arm64/simulator-arm64.cc b/chromium/v8/src/execution/arm64/simulator-arm64.cc
index 23a03848ad5..3853316a801 100644
--- a/chromium/v8/src/execution/arm64/simulator-arm64.cc
+++ b/chromium/v8/src/execution/arm64/simulator-arm64.cc
@@ -34,7 +34,7 @@ namespace internal {
 // SScanF not being implemented in a platform independent way through
 // ::v8::internal::OS in the same way as SNPrintF is that the
 // Windows C Run-Time Library does not provide vsscanf.
-#define SScanF sscanf  // NOLINT
+#define SScanF sscanf
 
 // Helpers for colors.
 #define COLOUR(colour_code) "\033[0;" colour_code "m"
diff --git a/chromium/v8/src/execution/execution.cc b/chromium/v8/src/execution/execution.cc
index 7866b406d90..b16e791aaa3 100644
--- a/chromium/v8/src/execution/execution.cc
+++ b/chromium/v8/src/execution/execution.cc
@@ -190,8 +190,12 @@ MaybeHandle<Context> NewScriptContext(Isolate* isolate,
       if (IsLexicalVariableMode(mode) || IsLexicalVariableMode(lookup.mode)) {
         Handle<Context> context = ScriptContextTable::GetContext(
             isolate, script_context, lookup.context_index);
-        // If we are trying to re-declare a REPL-mode let as a let, allow it.
-        if (!(mode == VariableMode::kLet && lookup.mode == VariableMode::kLet &&
+        // If we are trying to re-declare a REPL-mode let as a let or REPL-mode
+        // const as a const, allow it.
+        if (!(((mode == VariableMode::kLet &&
+                lookup.mode == VariableMode::kLet) ||
+               (mode == VariableMode::kConst &&
+                lookup.mode == VariableMode::kConst)) &&
               scope_info->IsReplModeScope() &&
               context->scope_info().IsReplModeScope())) {
           // ES#sec-globaldeclarationinstantiation 5.b:
@@ -244,7 +248,7 @@ MaybeHandle<Context> NewScriptContext(Isolate* isolate,
 
 V8_WARN_UNUSED_RESULT MaybeHandle<Object> Invoke(Isolate* isolate,
                                                  const InvokeParams& params) {
-  RuntimeCallTimerScope timer(isolate, RuntimeCallCounterId::kInvoke);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kInvoke);
   DCHECK(!params.receiver->IsJSGlobalObject());
   DCHECK_LE(params.argc, FixedArray::kMaxLength);
 
@@ -368,7 +372,7 @@ V8_WARN_UNUSED_RESULT MaybeHandle<Object> Invoke(Isolate* isolate,
       Address func = params.target->ptr();
       Address recv = params.receiver->ptr();
       Address** argv = reinterpret_cast<Address**>(params.argv);
-      RuntimeCallTimerScope timer(isolate, RuntimeCallCounterId::kJS_Execution);
+      RCS_SCOPE(isolate, RuntimeCallCounterId::kJS_Execution);
       value = Object(stub_entry.Call(isolate->isolate_data()->isolate_root(),
                                      orig_func, func, recv, params.argc, argv));
     } else {
@@ -383,7 +387,7 @@ V8_WARN_UNUSED_RESULT MaybeHandle<Object> Invoke(Isolate* isolate,
       JSEntryFunction stub_entry =
           JSEntryFunction::FromAddress(isolate, code->InstructionStart());
 
-      RuntimeCallTimerScope timer(isolate, RuntimeCallCounterId::kJS_Execution);
+      RCS_SCOPE(isolate, RuntimeCallCounterId::kJS_Execution);
       value = Object(stub_entry.Call(isolate->isolate_data()->isolate_root(),
                                      params.microtask_queue));
     }
@@ -552,7 +556,7 @@ void Execution::CallWasm(Isolate* isolate, Handle<Code> wrapper_code,
   trap_handler::SetThreadInWasm();
 
   {
-    RuntimeCallTimerScope timer(isolate, RuntimeCallCounterId::kJS_Execution);
+    RCS_SCOPE(isolate, RuntimeCallCounterId::kJS_Execution);
     STATIC_ASSERT(compiler::CWasmEntryParameters::kCodeEntry == 0);
     STATIC_ASSERT(compiler::CWasmEntryParameters::kObjectRef == 1);
     STATIC_ASSERT(compiler::CWasmEntryParameters::kArgumentsBuffer == 2);
diff --git a/chromium/v8/src/execution/external-pointer-table.h b/chromium/v8/src/execution/external-pointer-table.h
index 243682b36cf..4a80fe7d4dd 100644
--- a/chromium/v8/src/execution/external-pointer-table.h
+++ b/chromium/v8/src/execution/external-pointer-table.h
@@ -27,7 +27,7 @@ class V8_EXPORT_PRIVATE ExternalPointerTable {
     buffer_[kNullExternalPointer] = kNullAddress;
   }
 
-  ~ExternalPointerTable() { ::free(buffer_); }
+  ~ExternalPointerTable() { base::Free(buffer_); }
 
   Address get(uint32_t index) const {
     CHECK_LT(index, length_);
@@ -49,13 +49,6 @@ class V8_EXPORT_PRIVATE ExternalPointerTable {
     return index;
   }
 
-  void free(uint32_t index) {
-    // TODO(v8:10391, saelo): implement simple free list here, i.e. set
-    // buffer_[index] to freelist_head_ and set freelist_head
-    // to index
-    DCHECK_NE(kNullExternalPointer, index);
-  }
-
   // Returns true if the entry exists in the table and therefore it can be read.
   bool is_valid_index(uint32_t index) const {
     // TODO(v8:10391, saelo): also check here if entry is free
diff --git a/chromium/v8/src/execution/frame-constants.h b/chromium/v8/src/execution/frame-constants.h
index 10cdff5c0fc..1148a942123 100644
--- a/chromium/v8/src/execution/frame-constants.h
+++ b/chromium/v8/src/execution/frame-constants.h
@@ -390,23 +390,23 @@ inline static int FrameSlotToFPOffset(int slot) {
 }  // namespace v8
 
 #if V8_TARGET_ARCH_IA32
-#include "src/execution/ia32/frame-constants-ia32.h"  // NOLINT
+#include "src/execution/ia32/frame-constants-ia32.h"
 #elif V8_TARGET_ARCH_X64
-#include "src/execution/x64/frame-constants-x64.h"  // NOLINT
+#include "src/execution/x64/frame-constants-x64.h"
 #elif V8_TARGET_ARCH_ARM64
-#include "src/execution/arm64/frame-constants-arm64.h"  // NOLINT
+#include "src/execution/arm64/frame-constants-arm64.h"
 #elif V8_TARGET_ARCH_ARM
-#include "src/execution/arm/frame-constants-arm.h"  // NOLINT
+#include "src/execution/arm/frame-constants-arm.h"
 #elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
-#include "src/execution/ppc/frame-constants-ppc.h"  // NOLINT
+#include "src/execution/ppc/frame-constants-ppc.h"
 #elif V8_TARGET_ARCH_MIPS
-#include "src/execution/mips/frame-constants-mips.h"  // NOLINT
+#include "src/execution/mips/frame-constants-mips.h"
 #elif V8_TARGET_ARCH_MIPS64
-#include "src/execution/mips64/frame-constants-mips64.h"  // NOLINT
+#include "src/execution/mips64/frame-constants-mips64.h"
 #elif V8_TARGET_ARCH_S390
-#include "src/execution/s390/frame-constants-s390.h"  // NOLINT
+#include "src/execution/s390/frame-constants-s390.h"
 #elif V8_TARGET_ARCH_RISCV64
-#include "src/execution/riscv64/frame-constants-riscv64.h"  // NOLINT
+#include "src/execution/riscv64/frame-constants-riscv64.h"
 #else
 #error Unsupported target architecture.
 #endif
diff --git a/chromium/v8/src/execution/frames.cc b/chromium/v8/src/execution/frames.cc
index 65d34a56519..bef92948ebd 100644
--- a/chromium/v8/src/execution/frames.cc
+++ b/chromium/v8/src/execution/frames.cc
@@ -228,8 +228,8 @@ bool IsInterpreterFramePc(Isolate* isolate, Address pc,
   Builtins::Name builtin_index = InstructionStream::TryLookupCode(isolate, pc);
   if (builtin_index != Builtins::kNoBuiltinId &&
       (builtin_index == Builtins::kInterpreterEntryTrampoline ||
-       builtin_index == Builtins::kInterpreterEnterBytecodeAdvance ||
-       builtin_index == Builtins::kInterpreterEnterBytecodeDispatch ||
+       builtin_index == Builtins::kInterpreterEnterAtBytecode ||
+       builtin_index == Builtins::kInterpreterEnterAtNextBytecode ||
        builtin_index == Builtins::kBaselineEnterAtBytecode ||
        builtin_index == Builtins::kBaselineEnterAtNextBytecode)) {
     return true;
@@ -610,7 +610,6 @@ StackFrame::Type StackFrame::ComputeType(const StackFrameIteratorBase* iterator,
           }
           return BUILTIN;
         case CodeKind::TURBOFAN:
-        case CodeKind::NATIVE_CONTEXT_INDEPENDENT:
         case CodeKind::TURBOPROP:
           return OPTIMIZED;
         case CodeKind::BASELINE:
@@ -1060,12 +1059,14 @@ void CommonFrame::IterateCompiledFrame(RootVisitor* v) const {
   }
 
   // Visit pointer spill slots and locals.
-  uint8_t* safepoint_bits = safepoint_entry.bits();
-  for (unsigned index = 0; index < stack_slots; index++) {
-    int byte_index = index >> kBitsPerByteLog2;
-    int bit_index = index & (kBitsPerByte - 1);
-    if ((safepoint_bits[byte_index] & (1U << bit_index)) != 0) {
-      FullObjectSlot spill_slot = parameters_limit + index;
+  DCHECK_GE((stack_slots + kBitsPerByte) / kBitsPerByte,
+            safepoint_entry.entry_size());
+  int slot_offset = 0;
+  for (uint8_t bits : safepoint_entry.iterate_bits()) {
+    while (bits) {
+      int bit = base::bits::CountTrailingZeros(bits);
+      bits &= ~(1 << bit);
+      FullObjectSlot spill_slot = parameters_limit + slot_offset + bit;
 #ifdef V8_COMPRESS_POINTERS
       // Spill slots may contain compressed values in which case the upper
       // 32-bits will contain zeros. In order to simplify handling of such
@@ -1083,6 +1084,7 @@ void CommonFrame::IterateCompiledFrame(RootVisitor* v) const {
 #endif
       v->VisitRootPointer(Root::kStackRoots, nullptr, spill_slot);
     }
+    slot_offset += kBitsPerByte;
   }
 
   // Visit tagged parameters that have been passed to the function of this
@@ -1444,10 +1446,6 @@ Handle<Object> FrameSummary::JavaScriptFrameSummary::script() const {
   return handle(function_->shared().script(), isolate());
 }
 
-Handle<String> FrameSummary::JavaScriptFrameSummary::FunctionName() const {
-  return JSFunction::GetDebugName(function_);
-}
-
 Handle<Context> FrameSummary::JavaScriptFrameSummary::native_context() const {
   return handle(function_->context().native_context(), isolate());
 }
@@ -1485,13 +1483,6 @@ Handle<Script> FrameSummary::WasmFrameSummary::script() const {
                 wasm_instance()->GetIsolate());
 }
 
-Handle<String> FrameSummary::WasmFrameSummary::FunctionName() const {
-  Handle<WasmModuleObject> module_object(wasm_instance()->module_object(),
-                                         isolate());
-  return WasmModuleObject::GetFunctionName(isolate(), module_object,
-                                           function_index());
-}
-
 Handle<Context> FrameSummary::WasmFrameSummary::native_context() const {
   return handle(wasm_instance()->native_context(), isolate());
 }
@@ -1563,7 +1554,6 @@ FRAME_SUMMARY_DISPATCH(bool, is_subject_to_debugging)
 FRAME_SUMMARY_DISPATCH(Handle<Object>, script)
 FRAME_SUMMARY_DISPATCH(int, SourcePosition)
 FRAME_SUMMARY_DISPATCH(int, SourceStatementPosition)
-FRAME_SUMMARY_DISPATCH(Handle<String>, FunctionName)
 FRAME_SUMMARY_DISPATCH(Handle<Context>, native_context)
 
 #undef FRAME_SUMMARY_DISPATCH
@@ -1860,8 +1850,13 @@ int BuiltinFrame::ComputeParametersCount() const {
 #if V8_ENABLE_WEBASSEMBLY
 void WasmFrame::Print(StringStream* accumulator, PrintMode mode,
                       int index) const {
-  wasm::WasmCodeRefScope code_ref_scope;
   PrintIndex(accumulator, mode, index);
+  if (function_index() == wasm::kAnonymousFuncIndex) {
+    accumulator->Add("Anonymous wasm wrapper [pc: %p]\n",
+                     reinterpret_cast<void*>(pc()));
+    return;
+  }
+  wasm::WasmCodeRefScope code_ref_scope;
   accumulator->Add("WASM [");
   accumulator->PrintName(script().name());
   Address instruction_start = isolate()
@@ -1905,7 +1900,7 @@ WasmModuleObject WasmFrame::module_object() const {
   return wasm_instance().module_object();
 }
 
-uint32_t WasmFrame::function_index() const {
+int WasmFrame::function_index() const {
   wasm::WasmCodeRefScope code_ref_scope;
   return wasm_code()->index();
 }
diff --git a/chromium/v8/src/execution/frames.h b/chromium/v8/src/execution/frames.h
index 32157b4cc12..8d9dadd76d2 100644
--- a/chromium/v8/src/execution/frames.h
+++ b/chromium/v8/src/execution/frames.h
@@ -138,9 +138,7 @@ class StackFrame {
     INNER_JSENTRY_FRAME = (0 << kSmiTagSize) | kSmiTag,
     OUTERMOST_JSENTRY_FRAME = (1 << kSmiTagSize) | kSmiTag
   };
-  // NOLINTNEXTLINE(runtime/references) (false positive)
   STATIC_ASSERT((INNER_JSENTRY_FRAME & kHeapObjectTagMask) != kHeapObjectTag);
-  // NOLINTNEXTLINE(runtime/references) (false positive)
   STATIC_ASSERT((OUTERMOST_JSENTRY_FRAME & kHeapObjectTagMask) !=
                 kHeapObjectTag);
 
@@ -389,7 +387,6 @@ class V8_EXPORT_PRIVATE FrameSummary {
     int SourcePosition() const;
     int SourceStatementPosition() const;
     Handle<Object> script() const;
-    Handle<String> FunctionName() const;
     Handle<Context> native_context() const;
 
    private:
@@ -418,7 +415,6 @@ class V8_EXPORT_PRIVATE FrameSummary {
     int SourceStatementPosition() const { return SourcePosition(); }
     Handle<Script> script() const;
     Handle<WasmInstanceObject> wasm_instance() const { return wasm_instance_; }
-    Handle<String> FunctionName() const;
     Handle<Context> native_context() const;
     bool at_to_number_conversion() const { return at_to_number_conversion_; }
 
@@ -453,7 +449,6 @@ class V8_EXPORT_PRIVATE FrameSummary {
   Handle<Object> script() const;
   int SourcePosition() const;
   int SourceStatementPosition() const;
-  Handle<String> FunctionName() const;
   Handle<Context> native_context() const;
 
 #define FRAME_SUMMARY_CAST(kind_, type, field, desc)      \
@@ -964,7 +959,7 @@ class WasmFrame : public TypedFrame {
   V8_EXPORT_PRIVATE WasmInstanceObject wasm_instance() const;
   V8_EXPORT_PRIVATE wasm::NativeModule* native_module() const;
   wasm::WasmCode* wasm_code() const;
-  uint32_t function_index() const;
+  int function_index() const;
   Script script() const;
   // Byte position in the module, or asm.js source position.
   int position() const override;
diff --git a/chromium/v8/src/execution/isolate-data.h b/chromium/v8/src/execution/isolate-data.h
index a6610c12f08..bc3e2b8d1a6 100644
--- a/chromium/v8/src/execution/isolate-data.h
+++ b/chromium/v8/src/execution/isolate-data.h
@@ -29,13 +29,19 @@ class Isolate;
 // register.
 class IsolateData final {
  public:
-  explicit IsolateData(Isolate* isolate) : stack_guard_(isolate) {}
+  IsolateData(Isolate* isolate, Address cage_base)
+      : cage_base_(cage_base), stack_guard_(isolate) {}
 
   IsolateData(const IsolateData&) = delete;
   IsolateData& operator=(const IsolateData&) = delete;
 
   static constexpr intptr_t kIsolateRootBias = kRootRegisterBias;
 
+  // The value of kPointerCageBaseRegister
+  Address cage_base() const {
+    return COMPRESS_POINTERS_BOOL ? cage_base_ : kNullAddress;
+  }
+
   // The value of the kRootRegister.
   Address isolate_root() const {
     return reinterpret_cast<Address>(this) + kIsolateRootBias;
@@ -61,7 +67,7 @@ class IsolateData final {
     return kBuiltinEntryTableOffset - kIsolateRootBias;
   }
   static constexpr int builtin_entry_slot_offset(Builtins::Name builtin_index) {
-    CONSTEXPR_DCHECK(Builtins::IsBuiltinId(builtin_index));
+    DCHECK(Builtins::IsBuiltinId(builtin_index));
     return builtin_entry_table_offset() + builtin_index * kSystemPointerSize;
   }
 
@@ -70,6 +76,13 @@ class IsolateData final {
     return kBuiltinsTableOffset - kIsolateRootBias;
   }
 
+  // Root-register-relative offset of the external pointer table.
+#ifdef V8_HEAP_SANDBOX
+  static constexpr int external_pointer_table_offset() {
+    return kExternalPointerTableOffset - kIsolateRootBias;
+  }
+#endif
+
   static constexpr int fast_c_call_caller_fp_offset() {
     return kFastCCallCallerFPOffset - kIsolateRootBias;
   }
@@ -82,6 +95,10 @@ class IsolateData final {
     return kFastApiCallTargetOffset - kIsolateRootBias;
   }
 
+  static constexpr int cage_base_offset() {
+    return kCageBaseOffset - kIsolateRootBias;
+  }
+
   // Root-register-relative offset of the given builtin table entry.
   // TODO(ishell): remove in favour of typified id version.
   static int builtin_slot_offset(int builtin_index) {
@@ -142,6 +159,8 @@ class IsolateData final {
   V(kFastCCallCallerFPOffset, kSystemPointerSize)                             \
   V(kFastCCallCallerPCOffset, kSystemPointerSize)                             \
   V(kFastApiCallTargetOffset, kSystemPointerSize)                             \
+  V(kCageBaseOffset, kSystemPointerSize)                                      \
+  V(kLongTaskStatsCounterOffset, kSizetSize)                                  \
   V(kStackGuardOffset, StackGuard::kSizeInBytes)                              \
   V(kRootsTableOffset, RootsTable::kEntriesCount* kSystemPointerSize)         \
   V(kExternalReferenceTableOffset, ExternalReferenceTable::kSizeInBytes)      \
@@ -180,6 +199,12 @@ class IsolateData final {
   Address fast_c_call_caller_pc_ = kNullAddress;
   Address fast_api_call_target_ = kNullAddress;
 
+  Address cage_base_ = kNullAddress;
+
+  // Used for implementation of LongTaskStats. Counts the number of potential
+  // long tasks.
+  size_t long_task_stats_counter_ = 0;
+
   // Fields related to the system and JS stack. In particular, this contains
   // the stack limit used by stack checks in generated code.
   StackGuard stack_guard_;
@@ -245,6 +270,9 @@ void IsolateData::AssertPredictableLayout() {
                 kFastCCallCallerPCOffset);
   STATIC_ASSERT(offsetof(IsolateData, fast_api_call_target_) ==
                 kFastApiCallTargetOffset);
+  STATIC_ASSERT(offsetof(IsolateData, cage_base_) == kCageBaseOffset);
+  STATIC_ASSERT(offsetof(IsolateData, long_task_stats_counter_) ==
+                kLongTaskStatsCounterOffset);
   STATIC_ASSERT(offsetof(IsolateData, stack_guard_) == kStackGuardOffset);
 #ifdef V8_HEAP_SANDBOX
   STATIC_ASSERT(offsetof(IsolateData, external_pointer_table_) ==
diff --git a/chromium/v8/src/execution/isolate-utils-inl.h b/chromium/v8/src/execution/isolate-utils-inl.h
index f199b525aab..1e91d494aaa 100644
--- a/chromium/v8/src/execution/isolate-utils-inl.h
+++ b/chromium/v8/src/execution/isolate-utils-inl.h
@@ -51,7 +51,7 @@ V8_INLINE Heap* GetHeapFromWritableObject(HeapObject object) {
   heap_internals::MemoryChunk* chunk =
       heap_internals::MemoryChunk::FromHeapObject(object);
   return chunk->GetHeap();
-#endif  // V8_COMPRESS_POINTERS || V8_ENABLE_THIRD_PARTY_HEAP
+#endif  // V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE, V8_ENABLE_THIRD_PARTY_HEAP
 }
 
 V8_INLINE Isolate* GetIsolateFromWritableObject(HeapObject object) {
@@ -64,14 +64,14 @@ V8_INLINE Isolate* GetIsolateFromWritableObject(HeapObject object) {
   return isolate;
 #else
   return Isolate::FromHeap(GetHeapFromWritableObject(object));
-#endif  // V8_COMPRESS_POINTERS, V8_ENABLE_THIRD_PARTY_HEAP
+#endif  // V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE, V8_ENABLE_THIRD_PARTY_HEAP
 }
 
 V8_INLINE bool GetIsolateFromHeapObject(HeapObject object, Isolate** isolate) {
 #ifdef V8_ENABLE_THIRD_PARTY_HEAP
   *isolate = Heap::GetIsolateFromWritableObject(object);
   return true;
-#elif defined V8_COMPRESS_POINTERS
+#elif defined V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE
   *isolate = GetIsolateFromWritableObject(object);
   return true;
 #else
@@ -83,7 +83,18 @@ V8_INLINE bool GetIsolateFromHeapObject(HeapObject object, Isolate** isolate) {
   }
   *isolate = Isolate::FromHeap(chunk->GetHeap());
   return true;
-#endif  // V8_COMPRESS_POINTERS, V8_ENABLE_THIRD_PARTY_HEAP
+#endif  // V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE, V8_ENABLE_THIRD_PARTY_HEAP
+}
+
+// Use this function instead of Internals::GetIsolateForHeapSandbox for internal
+// code, as this function is fully inlinable.
+V8_INLINE static Isolate* GetIsolateForHeapSandbox(HeapObject object) {
+#ifdef V8_HEAP_SANDBOX
+  return GetIsolateFromWritableObject(object);
+#else
+  // Not used in non-sandbox mode.
+  return nullptr;
+#endif
 }
 
 }  // namespace internal
diff --git a/chromium/v8/src/execution/isolate.cc b/chromium/v8/src/execution/isolate.cc
index 6f133ece117..b4070372eee 100644
--- a/chromium/v8/src/execution/isolate.cc
+++ b/chromium/v8/src/execution/isolate.cc
@@ -7,7 +7,7 @@
 #include <stdlib.h>
 
 #include <atomic>
-#include <fstream>  // NOLINT(readability/streams)
+#include <fstream>
 #include <memory>
 #include <sstream>
 #include <string>
@@ -19,9 +19,11 @@
 #include "src/ast/scopes.h"
 #include "src/base/hashmap.h"
 #include "src/base/logging.h"
+#include "src/base/platform/mutex.h"
 #include "src/base/platform/platform.h"
 #include "src/base/sys-info.h"
 #include "src/base/utils/random-number-generator.h"
+#include "src/bigint/bigint.h"
 #include "src/builtins/builtins-promise.h"
 #include "src/builtins/constants-table-builder.h"
 #include "src/codegen/assembler-inl.h"
@@ -318,10 +320,6 @@ void Isolate::SetEmbeddedBlob(const uint8_t* code, uint32_t code_size,
     }
   }
 #endif  // DEBUG
-
-  if (FLAG_experimental_flush_embedded_blob_icache) {
-    FlushInstructionCache(const_cast<uint8_t*>(code), code_size);
-  }
 }
 
 void Isolate::ClearEmbeddedBlob() {
@@ -1404,12 +1402,15 @@ Object Isolate::StackOverflow() {
   Handle<JSFunction> fun = range_error_function();
   Handle<Object> msg = factory()->NewStringFromAsciiChecked(
       MessageFormatter::TemplateString(MessageTemplate::kStackOverflow));
+  Handle<Object> options = factory()->undefined_value();
   Handle<Object> no_caller;
-  Handle<Object> exception;
+  Handle<JSObject> exception;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
       this, exception,
-      ErrorUtils::Construct(this, fun, fun, msg, SKIP_NONE, no_caller,
+      ErrorUtils::Construct(this, fun, fun, msg, options, SKIP_NONE, no_caller,
                             ErrorUtils::StackTraceCollection::kSimple));
+  JSObject::AddProperty(this, exception, factory()->wasm_uncatchable_symbol(),
+                        factory()->true_value(), NONE);
 
   Throw(*exception);
 
@@ -1474,8 +1475,7 @@ void Isolate::RequestInterrupt(InterruptCallback callback, void* data) {
 }
 
 void Isolate::InvokeApiInterruptCallbacks() {
-  RuntimeCallTimerScope runtimeTimer(
-      this, RuntimeCallCounterId::kInvokeApiInterruptCallbacks);
+  RCS_SCOPE(this, RuntimeCallCounterId::kInvokeApiInterruptCallbacks);
   // Note: callback below should be called outside of execution access lock.
   while (true) {
     InterruptEntry entry;
@@ -1675,10 +1675,36 @@ Object Isolate::ReThrow(Object exception) {
   return ReadOnlyRoots(heap()).exception();
 }
 
+namespace {
+// This scope will set the thread-in-wasm flag after the execution of all
+// destructors. The thread-in-wasm flag is only set when the scope gets enabled.
+class SetThreadInWasmFlagScope {
+ public:
+  SetThreadInWasmFlagScope() {
+    DCHECK_IMPLIES(trap_handler::IsTrapHandlerEnabled(),
+                   !trap_handler::IsThreadInWasm());
+  }
+
+  ~SetThreadInWasmFlagScope() {
+    if (enabled_) trap_handler::SetThreadInWasm();
+  }
+
+  void Enable() { enabled_ = true; }
+
+ private:
+  bool enabled_ = false;
+};
+}  // namespace
+
 Object Isolate::UnwindAndFindHandler() {
+  // Create the {SetThreadInWasmFlagScope} first in this function so that its
+  // destructor gets called after all the other destructors. It is important
+  // that the destructor sets the thread-in-wasm flag after all other
+  // destructors. The other destructors may cause exceptions, e.g. ASan on
+  // Windows, which would invalidate the thread-in-wasm flag when the wasm trap
+  // handler handles such non-wasm exceptions.
+  SetThreadInWasmFlagScope set_thread_in_wasm_flag_scope;
   Object exception = pending_exception();
-  DCHECK_IMPLIES(trap_handler::IsTrapHandlerEnabled(),
-                 !trap_handler::IsThreadInWasm());
 
   auto FoundHandler = [&](Context context, Address instruction_start,
                           intptr_t handler_offset,
@@ -1771,9 +1797,10 @@ Object Isolate::UnwindAndFindHandler() {
                             StandardFrameConstants::kFixedFrameSizeAboveFp -
                             wasm_code->stack_slots() * kSystemPointerSize;
 
-        // This is going to be handled by Wasm, so we need to set the TLS flag.
-        trap_handler::SetThreadInWasm();
-
+        // This is going to be handled by WebAssembly, so we need to set the TLS
+        // flag. The {SetThreadInWasmFlagScope} will set the flag after all
+        // destructors have been executed.
+        set_thread_in_wasm_flag_scope.Enable();
         return FoundHandler(Context(), wasm_code->instruction_start(), offset,
                             wasm_code->constant_pool(), return_sp, frame->fp());
       }
@@ -1886,7 +1913,7 @@ Object Isolate::UnwindAndFindHandler() {
               static_cast<int>(offset));
 
           Code code =
-              builtins()->builtin(Builtins::kInterpreterEnterBytecodeDispatch);
+              builtins()->builtin(Builtins::kInterpreterEnterAtBytecode);
           return FoundHandler(context, code.InstructionStart(), 0,
                               code.constant_pool(), return_sp, frame->fp());
         }
@@ -2550,6 +2577,29 @@ void Isolate::SetAbortOnUncaughtExceptionCallback(
   abort_on_uncaught_exception_callback_ = callback;
 }
 
+void Isolate::InstallConditionalFeatures(Handle<Context> context) {
+  Handle<JSGlobalObject> global = handle(context->global_object(), this);
+  Handle<String> sab_name = factory()->SharedArrayBuffer_string();
+  if (IsSharedArrayBufferConstructorEnabled(context)) {
+    if (!JSObject::HasRealNamedProperty(global, sab_name).FromMaybe(true)) {
+      JSObject::AddProperty(this, global, factory()->SharedArrayBuffer_string(),
+                            shared_array_buffer_fun(), DONT_ENUM);
+    }
+  }
+}
+
+bool Isolate::IsSharedArrayBufferConstructorEnabled(Handle<Context> context) {
+  if (!FLAG_harmony_sharedarraybuffer) return false;
+
+  if (!FLAG_enable_sharedarraybuffer_per_context) return true;
+
+  if (sharedarraybuffer_constructor_enabled_callback()) {
+    v8::Local<v8::Context> api_context = v8::Utils::ToLocal(context);
+    return sharedarraybuffer_constructor_enabled_callback()(api_context);
+  }
+  return false;
+}
+
 bool Isolate::IsWasmSimdEnabled(Handle<Context> context) {
 #if V8_ENABLE_WEBASSEMBLY
   if (wasm_simd_enabled_callback()) {
@@ -2667,9 +2717,10 @@ void Isolate::UnregisterManagedPtrDestructor(ManagedPtrDestructor* destructor) {
 }
 
 #if V8_ENABLE_WEBASSEMBLY
-void Isolate::SetWasmEngine(std::shared_ptr<wasm::WasmEngine> engine) {
+void Isolate::SetWasmEngine(wasm::WasmEngine* engine) {
   DCHECK_NULL(wasm_engine_);  // Only call once before {Init}.
-  wasm_engine_ = std::move(engine);
+  DCHECK_NOT_NULL(engine);
+  wasm_engine_ = engine;
   wasm_engine_->AddIsolate(this);
 }
 
@@ -2683,7 +2734,6 @@ void Isolate::AddSharedWasmMemory(Handle<WasmMemoryObject> memory_object) {
 }
 #endif  // V8_ENABLE_WEBASSEMBLY
 
-// NOLINTNEXTLINE
 Isolate::PerIsolateThreadData::~PerIsolateThreadData() {
 #if defined(USE_SIMULATOR)
   delete simulator_;
@@ -2854,16 +2904,28 @@ std::atomic<size_t> Isolate::non_disposed_isolates_;
 #endif  // DEBUG
 
 // static
-Isolate* Isolate::New() {
+Isolate* Isolate::New() { return Isolate::Allocate(false); }
+
+// static
+Isolate* Isolate::NewShared(const v8::Isolate::CreateParams& params) {
+  Isolate* isolate = Isolate::Allocate(true);
+  v8::Isolate::Initialize(reinterpret_cast<v8::Isolate*>(isolate), params);
+  return isolate;
+}
+
+// static
+Isolate* Isolate::Allocate(bool is_shared) {
   // IsolateAllocator allocates the memory for the Isolate object according to
   // the given allocation mode.
   std::unique_ptr<IsolateAllocator> isolate_allocator =
       std::make_unique<IsolateAllocator>();
   // Construct Isolate object in the allocated memory.
   void* isolate_ptr = isolate_allocator->isolate_memory();
-  Isolate* isolate = new (isolate_ptr) Isolate(std::move(isolate_allocator));
+  Isolate* isolate =
+      new (isolate_ptr) Isolate(std::move(isolate_allocator), is_shared);
 #ifdef V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE
   DCHECK(IsAligned(isolate->isolate_root(), kPtrComprCageBaseAlignment));
+  DCHECK_EQ(isolate->isolate_root(), isolate->cage_base());
 #endif
 
 #ifdef DEBUG
@@ -2919,12 +2981,13 @@ void Isolate::SetUpFromReadOnlyArtifacts(
   heap_.SetUpFromReadOnlyHeap(read_only_heap_);
 }
 
-v8::PageAllocator* Isolate::page_allocator() {
+v8::PageAllocator* Isolate::page_allocator() const {
   return isolate_allocator_->page_allocator();
 }
 
-Isolate::Isolate(std::unique_ptr<i::IsolateAllocator> isolate_allocator)
-    : isolate_data_(this),
+Isolate::Isolate(std::unique_ptr<i::IsolateAllocator> isolate_allocator,
+                 bool is_shared)
+    : isolate_data_(this, isolate_allocator->GetPtrComprCageBase()),
       isolate_allocator_(std::move(isolate_allocator)),
       id_(isolate_counter.fetch_add(1, std::memory_order_relaxed)),
       allocator_(new TracingAccountingAllocator(this)),
@@ -2941,7 +3004,8 @@ Isolate::Isolate(std::unique_ptr<i::IsolateAllocator> isolate_allocator)
 #endif
       next_module_async_evaluating_ordinal_(
           SourceTextModule::kFirstAsyncEvaluatingOrdinal),
-      cancelable_task_manager_(new CancelableTaskManager()) {
+      cancelable_task_manager_(new CancelableTaskManager()),
+      is_shared_(is_shared) {
   TRACE_ISOLATE(constructor);
   CheckIsolateLayout();
 
@@ -2951,6 +3015,18 @@ Isolate::Isolate(std::unique_ptr<i::IsolateAllocator> isolate_allocator)
 
   handle_scope_data_.Initialize();
 
+  // When pointer compression is on with a per-Isolate cage, allocation in the
+  // shared Isolate can point into the per-Isolate RO heap as the offsets are
+  // constant across Isolates.
+  //
+  // When pointer compression is on with a shared cage or when pointer
+  // compression is off, a shared RO heap is required. Otherwise a shared
+  // allocation requested by a client Isolate could point into the client
+  // Isolate's RO space (e.g. an RO map) whose pages gets unmapped when it is
+  // disposed.
+  CHECK_IMPLIES(is_shared_, COMPRESS_POINTERS_IN_ISOLATE_CAGE_BOOL ||
+                                V8_SHARED_RO_HEAP_BOOL);
+
 #define ISOLATE_INIT_EXECUTE(type, name, initial_value) \
   name##_ = (initial_value);
   ISOLATE_INIT_LIST(ISOLATE_INIT_EXECUTE)
@@ -2979,6 +3055,11 @@ void Isolate::CheckIsolateLayout() {
   CHECK_EQ(static_cast<int>(
                OFFSET_OF(Isolate, isolate_data_.fast_c_call_caller_pc_)),
            Internals::kIsolateFastCCallCallerPcOffset);
+  CHECK_EQ(static_cast<int>(OFFSET_OF(Isolate, isolate_data_.cage_base_)),
+           Internals::kIsolateCageBaseOffset);
+  CHECK_EQ(static_cast<int>(
+               OFFSET_OF(Isolate, isolate_data_.long_task_stats_counter_)),
+           Internals::kIsolateLongTaskStatsCounterOffset);
   CHECK_EQ(static_cast<int>(OFFSET_OF(Isolate, isolate_data_.stack_guard_)),
            Internals::kIsolateStackGuardOffset);
   CHECK_EQ(static_cast<int>(OFFSET_OF(Isolate, isolate_data_.roots_)),
@@ -3020,10 +3101,10 @@ void Isolate::Deinit() {
 
 #if defined(V8_OS_WIN64)
   if (win64_unwindinfo::CanRegisterUnwindInfoForNonABICompliantCodeRange() &&
-      heap()->memory_allocator() && RequiresCodeRange()) {
-    const base::AddressRegion& code_range =
-        heap()->memory_allocator()->code_range();
-    void* start = reinterpret_cast<void*>(code_range.begin());
+      heap()->memory_allocator() && RequiresCodeRange() &&
+      heap()->code_range()->AtomicDecrementUnwindInfoUseCount() == 1) {
+    const base::AddressRegion& code_region = heap()->code_region();
+    void* start = reinterpret_cast<void*>(code_region.begin());
     win64_unwindinfo::UnregisterNonABICompliantCodeRange(start);
   }
 #endif  // V8_OS_WIN64
@@ -3044,6 +3125,9 @@ void Isolate::Deinit() {
     optimizing_compile_dispatcher_ = nullptr;
   }
 
+  // All client isolates should already be detached.
+  DCHECK_NULL(client_isolate_head_);
+
   // Help sweeper threads complete sweeping to stop faster.
   heap_.mark_compact_collector()->DrainSweepingWorklists();
   heap_.mark_compact_collector()->sweeper()->EnsureIterabilityCompleted();
@@ -3090,6 +3174,10 @@ void Isolate::Deinit() {
 
   main_thread_local_isolate_->heap()->FreeLinearAllocationArea();
 
+  if (shared_isolate_) {
+    DetachFromSharedIsolate();
+  }
+
   heap_.TearDown();
 
   main_thread_local_isolate_.reset();
@@ -3098,10 +3186,7 @@ void Isolate::Deinit() {
   if (logfile != nullptr) base::Fclose(logfile);
 
 #if V8_ENABLE_WEBASSEMBLY
-  if (wasm_engine_) {
-    wasm_engine_->RemoveIsolate(this);
-    wasm_engine_.reset();
-  }
+  wasm_engine_->RemoveIsolate(this);
 #endif  // V8_ENABLE_WEBASSEMBLY
 
   TearDownEmbeddedBlob();
@@ -3182,6 +3267,8 @@ Isolate::~Isolate() {
   delete thread_manager_;
   thread_manager_ = nullptr;
 
+  bigint_processor_->Destroy();
+
   delete global_handles_;
   global_handles_ = nullptr;
   delete eternal_handles_;
@@ -3389,8 +3476,9 @@ void Isolate::MaybeRemapEmbeddedBuiltinsIntoCodeRange() {
   CHECK_NOT_NULL(embedded_blob_code_);
   CHECK_NE(embedded_blob_code_size_, 0);
 
-  embedded_blob_code_ = heap_.RemapEmbeddedBuiltinsIntoCodeRange(
-      embedded_blob_code_, embedded_blob_code_size_);
+  DCHECK_NOT_NULL(heap_.code_range_);
+  embedded_blob_code_ = heap_.code_range_->RemapEmbeddedBuiltins(
+      this, embedded_blob_code_, embedded_blob_code_size_);
   CHECK_NOT_NULL(embedded_blob_code_);
   // The un-embedded code blob is already a part of the registered code range
   // so it's not necessary to register it again.
@@ -3474,6 +3562,21 @@ using MapOfLoadsAndStoresPerFunction =
     std::map<std::string /* function_name */,
              std::pair<uint64_t /* loads */, uint64_t /* stores */>>;
 MapOfLoadsAndStoresPerFunction* stack_access_count_map = nullptr;
+
+class BigIntPlatform : public bigint::Platform {
+ public:
+  explicit BigIntPlatform(Isolate* isolate) : isolate_(isolate) {}
+  ~BigIntPlatform() override = default;
+
+  bool InterruptRequested() override {
+    StackLimitCheck interrupt_check(isolate_);
+    return (interrupt_check.InterruptRequested() &&
+            isolate_->stack_guard()->HasTerminationRequest());
+  }
+
+ private:
+  Isolate* isolate_;
+};
 }  // namespace
 
 bool Isolate::Init(SnapshotData* startup_snapshot_data,
@@ -3522,6 +3625,7 @@ bool Isolate::Init(SnapshotData* startup_snapshot_data,
   heap_profiler_ = new HeapProfiler(heap());
   interpreter_ = new interpreter::Interpreter(this);
   string_table_.reset(new StringTable(this));
+  bigint_processor_ = bigint::Processor::New(new BigIntPlatform(this));
 
   compiler_dispatcher_ =
       new CompilerDispatcher(this, V8::GetCurrentPlatform(), FLAG_stack_size);
@@ -3531,7 +3635,7 @@ bool Isolate::Init(SnapshotData* startup_snapshot_data,
 
   metrics_recorder_ = std::make_shared<metrics::Recorder>();
 
-  {  // NOLINT
+  {
     // Ensure that the thread has a valid stack guard.  The v8::Locker object
     // will ensure this too, but we don't have to use lockers if we are only
     // using one thread.
@@ -3546,24 +3650,32 @@ bool Isolate::Init(SnapshotData* startup_snapshot_data,
   heap_.SetUpSpaces();
 
   if (V8_SHORT_BUILTIN_CALLS_BOOL && FLAG_short_builtin_calls) {
-    // Check if the system has more than 4GB of physical memory by comaring
-    // the old space size with respective threshod value.
-    is_short_builtin_calls_enabled_ =
-        heap_.MaxOldGenerationSize() >= kShortBuiltinCallsOldSpaceSizeThreshold;
+    // Check if the system has more than 4GB of physical memory by comparing the
+    // old space size with respective threshold value.
+    //
+    // Additionally, enable if there is already a process-wide CodeRange that
+    // has re-embedded builtins.
+    is_short_builtin_calls_enabled_ = (heap_.MaxOldGenerationSize() >=
+                                       kShortBuiltinCallsOldSpaceSizeThreshold);
+    if (COMPRESS_POINTERS_IN_SHARED_CAGE_BOOL) {
+      std::shared_ptr<CodeRange> code_range =
+          CodeRange::GetProcessWideCodeRange();
+      if (code_range && code_range->embedded_blob_code_copy() != nullptr) {
+        is_short_builtin_calls_enabled_ = true;
+      }
+    }
   }
 
   // Create LocalIsolate/LocalHeap for the main thread and set state to Running.
   main_thread_local_isolate_.reset(new LocalIsolate(this, ThreadKind::kMain));
   main_thread_local_heap()->Unpark();
 
+  heap_.InitializeMainThreadLocalHeap(main_thread_local_heap());
+
   isolate_data_.external_reference_table()->Init(this);
 
 #if V8_ENABLE_WEBASSEMBLY
-  // Setup the wasm engine.
-  if (wasm_engine_ == nullptr) {
-    SetWasmEngine(wasm::WasmEngine::GetWasmEngine());
-  }
-  DCHECK_NOT_NULL(wasm_engine_);
+  SetWasmEngine(wasm::WasmEngine::GetWasmEngine());
 #endif  // V8_ENABLE_WEBASSEMBLY
 
   if (setup_delegate_ == nullptr) {
@@ -3721,11 +3833,11 @@ bool Isolate::Init(SnapshotData* startup_snapshot_data,
   }
 
 #if defined(V8_OS_WIN64)
-  if (win64_unwindinfo::CanRegisterUnwindInfoForNonABICompliantCodeRange()) {
-    const base::AddressRegion& code_range =
-        heap()->memory_allocator()->code_range();
-    void* start = reinterpret_cast<void*>(code_range.begin());
-    size_t size_in_bytes = code_range.size();
+  if (win64_unwindinfo::CanRegisterUnwindInfoForNonABICompliantCodeRange() &&
+      heap()->code_range()->AtomicIncrementUnwindInfoUseCount() == 0) {
+    const base::AddressRegion& code_region = heap()->code_region();
+    void* start = reinterpret_cast<void*>(code_region.begin());
+    size_t size_in_bytes = code_region.size();
     win64_unwindinfo::RegisterNonABICompliantCodeRange(start, size_in_bytes);
   }
 #endif  // V8_OS_WIN64
@@ -3845,6 +3957,7 @@ void Isolate::DumpAndResetStats() {
     wasm_engine()->DumpAndResetTurboStatistics();
   }
 #endif  // V8_ENABLE_WEBASSEMBLY
+#if V8_RUNTIME_CALL_STATS
   if (V8_UNLIKELY(TracingFlags::runtime_stats.load(std::memory_order_relaxed) ==
                   v8::tracing::TracingCategoryObserver::ENABLED_BY_NATIVE)) {
     counters()->worker_thread_runtime_call_stats()->AddToMainTable(
@@ -3852,6 +3965,7 @@ void Isolate::DumpAndResetStats() {
     counters()->runtime_call_stats()->Print();
     counters()->runtime_call_stats()->Reset();
   }
+#endif  // V8_RUNTIME_CALL_STATS
   if (BasicBlockProfiler::Get()->HasData(this)) {
     StdoutStream out;
     BasicBlockProfiler::Get()->Print(out, this);
@@ -4121,19 +4235,23 @@ void Isolate::FireCallCompletedCallback(MicrotaskQueue* microtask_queue) {
   }
 }
 
-void Isolate::PromiseHookStateUpdated() {
-  bool promise_hook_or_async_event_delegate =
-      promise_hook_ || async_event_delegate_;
-  bool promise_hook_or_debug_is_active_or_async_event_delegate =
-      promise_hook_or_async_event_delegate || debug()->is_active();
-  if (promise_hook_or_debug_is_active_or_async_event_delegate &&
-      Protectors::IsPromiseHookIntact(this)) {
+void Isolate::UpdatePromiseHookProtector() {
+  if (Protectors::IsPromiseHookIntact(this)) {
     HandleScope scope(this);
     Protectors::InvalidatePromiseHook(this);
   }
-  promise_hook_or_async_event_delegate_ = promise_hook_or_async_event_delegate;
-  promise_hook_or_debug_is_active_or_async_event_delegate_ =
-      promise_hook_or_debug_is_active_or_async_event_delegate;
+}
+
+void Isolate::PromiseHookStateUpdated() {
+  promise_hook_flags_ =
+    (promise_hook_flags_ & PromiseHookFields::HasContextPromiseHook::kMask) |
+    PromiseHookFields::HasIsolatePromiseHook::encode(promise_hook_) |
+    PromiseHookFields::HasAsyncEventDelegate::encode(async_event_delegate_) |
+    PromiseHookFields::IsDebugActive::encode(debug()->is_active());
+
+  if (promise_hook_flags_ != 0) {
+    UpdatePromiseHookProtector();
+  }
 }
 
 namespace {
@@ -4260,11 +4378,15 @@ MaybeHandle<FixedArray> Isolate::GetImportAssertionsFromArgument(
   Handle<JSReceiver> import_assertions_object_receiver =
       Handle<JSReceiver>::cast(import_assertions_object);
 
-  Handle<FixedArray> assertion_keys =
-      KeyAccumulator::GetKeys(import_assertions_object_receiver,
-                              KeyCollectionMode::kOwnOnly, ENUMERABLE_STRINGS,
-                              GetKeysConversion::kConvertToString)
-          .ToHandleChecked();
+  Handle<FixedArray> assertion_keys;
+  if (!KeyAccumulator::GetKeys(import_assertions_object_receiver,
+                               KeyCollectionMode::kOwnOnly, ENUMERABLE_STRINGS,
+                               GetKeysConversion::kConvertToString)
+           .ToHandle(&assertion_keys)) {
+    // This happens if the assertions object is a Proxy whose ownKeys() or
+    // getOwnPropertyDescriptor() trap throws.
+    return MaybeHandle<FixedArray>();
+  }
 
   // The assertions will be passed to the host in the form: [key1,
   // value1, key2, value2, ...].
@@ -4311,7 +4433,7 @@ void Isolate::SetHostImportModuleDynamicallyCallback(
 
 MaybeHandle<JSObject> Isolate::RunHostInitializeImportMetaObjectCallback(
     Handle<SourceTextModule> module) {
-  CHECK(module->import_meta().IsTheHole(this));
+  CHECK(module->import_meta(kAcquireLoad).IsTheHole(this));
   Handle<JSObject> import_meta = factory()->NewJSObjectWithNullProto();
   if (host_initialize_import_meta_object_callback_ != nullptr) {
     v8::Local<v8::Context> api_context =
@@ -4433,17 +4555,30 @@ void Isolate::SetPromiseHook(PromiseHook hook) {
   PromiseHookStateUpdated();
 }
 
+void Isolate::RunAllPromiseHooks(PromiseHookType type,
+                                 Handle<JSPromise> promise,
+                                 Handle<Object> parent) {
+  if (HasContextPromiseHooks()) {
+    native_context()->RunPromiseHook(type, promise, parent);
+  }
+  if (HasIsolatePromiseHooks() || HasAsyncEventDelegate()) {
+    RunPromiseHook(type, promise, parent);
+  }
+}
+
 void Isolate::RunPromiseHook(PromiseHookType type, Handle<JSPromise> promise,
                              Handle<Object> parent) {
   RunPromiseHookForAsyncEventDelegate(type, promise);
-  if (promise_hook_ == nullptr) return;
+  if (!HasIsolatePromiseHooks()) return;
+  DCHECK(promise_hook_ != nullptr);
   promise_hook_(type, v8::Utils::PromiseToLocal(promise),
                 v8::Utils::ToLocal(parent));
 }
 
 void Isolate::RunPromiseHookForAsyncEventDelegate(PromiseHookType type,
                                                   Handle<JSPromise> promise) {
-  if (!async_event_delegate_) return;
+  if (!HasAsyncEventDelegate()) return;
+  DCHECK(async_event_delegate_ != nullptr);
   switch (type) {
     case PromiseHookType::kResolve:
       return;
@@ -4877,6 +5012,18 @@ MaybeLocal<v8::Context> Isolate::GetContextFromRecorderContextId(
   return result->second.Get(reinterpret_cast<v8::Isolate*>(this));
 }
 
+void Isolate::UpdateLongTaskStats() {
+  if (last_long_task_stats_counter_ != isolate_data_.long_task_stats_counter_) {
+    last_long_task_stats_counter_ = isolate_data_.long_task_stats_counter_;
+    long_task_stats_ = v8::metrics::LongTaskStats{};
+  }
+}
+
+v8::metrics::LongTaskStats* Isolate::GetCurrentLongTaskStats() {
+  UpdateLongTaskStats();
+  return &long_task_stats_;
+}
+
 void Isolate::RemoveContextIdCallback(const v8::WeakCallbackInfo<void>& data) {
   Isolate* isolate = reinterpret_cast<Isolate*>(data.GetIsolate());
   uintptr_t context_id = reinterpret_cast<uintptr_t>(data.GetParameter());
@@ -4953,5 +5100,54 @@ Address Isolate::store_to_stack_count_address(const char* function_name) {
   return reinterpret_cast<Address>(&map[name].second);
 }
 
+void Isolate::AttachToSharedIsolate(Isolate* shared) {
+  DCHECK(shared->is_shared());
+  DCHECK_NULL(shared_isolate_);
+  shared->AppendAsClientIsolate(this);
+  shared_isolate_ = shared;
+  heap()->InitSharedSpaces();
+}
+
+void Isolate::DetachFromSharedIsolate() {
+  DCHECK_NOT_NULL(shared_isolate_);
+  shared_isolate_->RemoveAsClientIsolate(this);
+  shared_isolate_ = nullptr;
+  heap()->DeinitSharedSpaces();
+}
+
+void Isolate::AppendAsClientIsolate(Isolate* client) {
+  base::MutexGuard guard(&client_isolate_mutex_);
+
+  DCHECK_NULL(client->prev_client_isolate_);
+  DCHECK_NULL(client->next_client_isolate_);
+  DCHECK_NE(client_isolate_head_, client);
+
+  if (client_isolate_head_) {
+    client_isolate_head_->prev_client_isolate_ = client;
+  }
+
+  client->prev_client_isolate_ = nullptr;
+  client->next_client_isolate_ = client_isolate_head_;
+
+  client_isolate_head_ = client;
+}
+
+void Isolate::RemoveAsClientIsolate(Isolate* client) {
+  base::MutexGuard guard(&client_isolate_mutex_);
+
+  if (client->next_client_isolate_) {
+    client->next_client_isolate_->prev_client_isolate_ =
+        client->prev_client_isolate_;
+  }
+
+  if (client->prev_client_isolate_) {
+    client->prev_client_isolate_->next_client_isolate_ =
+        client->next_client_isolate_;
+  } else {
+    DCHECK_EQ(client_isolate_head_, client);
+    client_isolate_head_ = client->next_client_isolate_;
+  }
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/execution/isolate.h b/chromium/v8/src/execution/isolate.h
index 61934d56190..f55af20acdf 100644
--- a/chromium/v8/src/execution/isolate.h
+++ b/chromium/v8/src/execution/isolate.h
@@ -13,7 +13,6 @@
 #include <unordered_map>
 #include <vector>
 
-#include "include/v8-inspector.h"
 #include "include/v8-internal.h"
 #include "include/v8-metrics.h"
 #include "include/v8.h"
@@ -48,12 +47,20 @@ class UMemory;
 }  // namespace U_ICU_NAMESPACE
 #endif  // V8_INTL_SUPPORT
 
+namespace v8_inspector {
+class V8Inspector;
+}  // namespace v8_inspector
+
 namespace v8 {
 
 namespace base {
 class RandomNumberGenerator;
 }  // namespace base
 
+namespace bigint {
+class Processor;
+}
+
 namespace debug {
 class ConsoleDelegate;
 class AsyncEventDelegate;
@@ -430,6 +437,8 @@ using DebugObjectCache = std::vector<Handle<HeapObject>>;
   V(AllowWasmCodeGenerationCallback, allow_wasm_code_gen_callback, nullptr)   \
   V(ExtensionCallback, wasm_module_callback, &NoExtension)                    \
   V(ExtensionCallback, wasm_instance_callback, &NoExtension)                  \
+  V(SharedArrayBufferConstructorEnabledCallback,                              \
+    sharedarraybuffer_constructor_enabled_callback, nullptr)                  \
   V(WasmStreamingCallback, wasm_streaming_callback, nullptr)                  \
   V(WasmLoadSourceMapCallback, wasm_load_source_map_callback, nullptr)        \
   V(WasmSimdEnabledCallback, wasm_simd_enabled_callback, nullptr)             \
@@ -548,6 +557,9 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   // new operator.
   static Isolate* New();
 
+  // Creates a new shared Isolate object.
+  static Isolate* NewShared(const v8::Isolate::CreateParams& params);
+
   // Deletes Isolate object. Must be used instead of delete operator.
   // Destroys the non-default isolates.
   // Sets default isolate into "has_been_disposed" state rather then destroying,
@@ -559,7 +571,7 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   void set_read_only_heap(ReadOnlyHeap* ro_heap) { read_only_heap_ = ro_heap; }
 
   // Page allocator that must be used for allocating V8 heap pages.
-  v8::PageAllocator* page_allocator();
+  v8::PageAllocator* page_allocator() const;
 
   // Returns the PerIsolateThreadData for the current thread (or nullptr if one
   // is not currently set).
@@ -659,12 +671,12 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   base::SharedMutex* map_updater_access() { return &map_updater_access_; }
 
   // The isolate's string table.
-  StringTable* string_table() { return string_table_.get(); }
+  StringTable* string_table() const { return string_table_.get(); }
 
   Address get_address_from_id(IsolateAddressId id);
 
   // Access to top context (where the current function object was created).
-  Context context() { return thread_local_top()->context_; }
+  Context context() const { return thread_local_top()->context_; }
   inline void set_context(Context context);
   Context* context_address() { return &thread_local_top()->context_; }
 
@@ -681,6 +693,10 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   inline void set_pending_exception(Object exception_obj);
   inline void clear_pending_exception();
 
+  void InstallConditionalFeatures(Handle<Context> context);
+
+  bool IsSharedArrayBufferConstructorEnabled(Handle<Context> context);
+
   bool IsWasmSimdEnabled(Handle<Context> context);
   bool AreWasmExceptionsEnabled(Handle<Context> context);
 
@@ -1021,6 +1037,25 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   const IsolateData* isolate_data() const { return &isolate_data_; }
   IsolateData* isolate_data() { return &isolate_data_; }
 
+  // When pointer compression is on, this is the base address of the pointer
+  // compression cage, and the kPtrComprCageBaseRegister is set to this
+  // value. When pointer compression is off, this is always kNullAddress.
+  Address cage_base() const {
+    DCHECK_IMPLIES(!COMPRESS_POINTERS_IN_ISOLATE_CAGE_BOOL &&
+                       !COMPRESS_POINTERS_IN_SHARED_CAGE_BOOL,
+                   isolate_data()->cage_base() == kNullAddress);
+    return isolate_data()->cage_base();
+  }
+
+  // When pointer compression is on, the PtrComprCage used by this
+  // Isolate. Otherwise nullptr.
+  VirtualMemoryCage* GetPtrComprCage() {
+    return isolate_allocator_->GetPtrComprCage();
+  }
+  const VirtualMemoryCage* GetPtrComprCage() const {
+    return isolate_allocator_->GetPtrComprCage();
+  }
+
   // Generated code can embed this address to get access to the isolate-specific
   // data (for example, roots, external references, builtins, etc.).
   // The kRootRegister is set to this value.
@@ -1047,7 +1082,7 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
                                sizeof(IsolateData));
   }
 
-  Object root(RootIndex index) { return Object(roots_table()[index]); }
+  Object root(RootIndex index) const { return Object(roots_table()[index]); }
 
   Handle<Object> root_handle(RootIndex index) {
     return Handle<Object>(&roots_table()[index]);
@@ -1063,8 +1098,8 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
 
   bool IsBuiltinsTableHandleLocation(Address* handle_location);
 
-  StubCache* load_stub_cache() { return load_stub_cache_; }
-  StubCache* store_stub_cache() { return store_stub_cache_; }
+  StubCache* load_stub_cache() const { return load_stub_cache_; }
+  StubCache* store_stub_cache() const { return store_stub_cache_; }
   Deoptimizer* GetAndClearCurrentDeoptimizer() {
     Deoptimizer* result = current_deoptimizer_;
     CHECK_NOT_NULL(result);
@@ -1101,32 +1136,34 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
 
   THREAD_LOCAL_TOP_ADDRESS(Address, thread_in_wasm_flag_address)
 
-  MaterializedObjectStore* materialized_object_store() {
+  MaterializedObjectStore* materialized_object_store() const {
     return materialized_object_store_;
   }
 
-  DescriptorLookupCache* descriptor_lookup_cache() {
+  DescriptorLookupCache* descriptor_lookup_cache() const {
     return descriptor_lookup_cache_;
   }
 
   HandleScopeData* handle_scope_data() { return &handle_scope_data_; }
 
-  HandleScopeImplementer* handle_scope_implementer() {
+  HandleScopeImplementer* handle_scope_implementer() const {
     DCHECK(handle_scope_implementer_);
     return handle_scope_implementer_;
   }
 
-  UnicodeCache* unicode_cache() { return unicode_cache_; }
+  UnicodeCache* unicode_cache() const { return unicode_cache_; }
 
   InnerPointerToCodeCache* inner_pointer_to_code_cache() {
     return inner_pointer_to_code_cache_;
   }
 
-  GlobalHandles* global_handles() { return global_handles_; }
+  GlobalHandles* global_handles() const { return global_handles_; }
 
-  EternalHandles* eternal_handles() { return eternal_handles_; }
+  EternalHandles* eternal_handles() const { return eternal_handles_; }
 
-  ThreadManager* thread_manager() { return thread_manager_; }
+  ThreadManager* thread_manager() const { return thread_manager_; }
+
+  bigint::Processor* bigint_processor() { return bigint_processor_; }
 
 #ifndef V8_INTL_SUPPORT
   unibrow::Mapping<unibrow::Ecma262UnCanonicalize>* jsregexp_uncanonicalize() {
@@ -1147,14 +1184,16 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
 
   Builtins* builtins() { return &builtins_; }
 
-  RegExpStack* regexp_stack() { return regexp_stack_; }
+  RegExpStack* regexp_stack() const { return regexp_stack_; }
 
-  size_t total_regexp_code_generated() { return total_regexp_code_generated_; }
+  size_t total_regexp_code_generated() const {
+    return total_regexp_code_generated_;
+  }
   void IncreaseTotalRegexpCodeGenerated(Handle<HeapObject> code);
 
   std::vector<int>* regexp_indices() { return &regexp_indices_; }
 
-  Debug* debug() { return debug_; }
+  Debug* debug() const { return debug_; }
 
   void* is_profiling_address() { return &is_profiling_; }
 
@@ -1178,8 +1217,7 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   v8::internal::Factory* factory() {
     // Upcast to the privately inherited base-class using c-style casts to avoid
     // undefined behavior (as static_cast cannot cast across private bases).
-    // NOLINTNEXTLINE (google-readability-casting)
-    return (v8::internal::Factory*)this;  // NOLINT(readability/casting)
+    return (v8::internal::Factory*)this;
   }
 
   static const int kJSRegexpStaticOffsetsVectorSize = 128;
@@ -1192,7 +1230,7 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
     DCHECK_LT(slot, Internals::kNumIsolateDataSlots);
     isolate_data_.embedder_data_[slot] = data;
   }
-  void* GetData(uint32_t slot) {
+  void* GetData(uint32_t slot) const {
     DCHECK_LT(slot, Internals::kNumIsolateDataSlots);
     return isolate_data_.embedder_data_[slot];
   }
@@ -1205,7 +1243,7 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
     return snapshot_blob_ != nullptr && snapshot_blob_->raw_size != 0;
   }
 
-  bool IsDead() { return has_fatal_error_; }
+  bool IsDead() const { return has_fatal_error_; }
   void SignalFatalError() { has_fatal_error_ = true; }
 
   bool use_optimizer();
@@ -1261,11 +1299,11 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
 
   void MaybeInitializeVectorListFromHeap();
 
-  double time_millis_since_init() {
+  double time_millis_since_init() const {
     return heap_.MonotonicallyIncreasingTimeInMs() - time_millis_at_init_;
   }
 
-  DateCache* date_cache() { return date_cache_; }
+  DateCache* date_cache() const { return date_cache_; }
 
   void set_date_cache(DateCache* date_cache);
 
@@ -1319,7 +1357,7 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
 
   std::unique_ptr<PersistentHandles> NewPersistentHandles();
 
-  PersistentHandlesList* persistent_handles_list() {
+  PersistentHandlesList* persistent_handles_list() const {
     return persistent_handles_list_.get();
   }
 
@@ -1437,21 +1475,27 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   }
 #endif
 
-  Address promise_hook_address() {
-    return reinterpret_cast<Address>(&promise_hook_);
+  void SetHasContextPromiseHooks(bool context_promise_hook) {
+    promise_hook_flags_ = PromiseHookFields::HasContextPromiseHook::update(
+        promise_hook_flags_, context_promise_hook);
+    PromiseHookStateUpdated();
   }
 
-  Address async_event_delegate_address() {
-    return reinterpret_cast<Address>(&async_event_delegate_);
+  bool HasContextPromiseHooks() const {
+    return PromiseHookFields::HasContextPromiseHook::decode(
+        promise_hook_flags_);
   }
 
-  Address promise_hook_or_async_event_delegate_address() {
-    return reinterpret_cast<Address>(&promise_hook_or_async_event_delegate_);
+  Address promise_hook_flags_address() {
+    return reinterpret_cast<Address>(&promise_hook_flags_);
+  }
+
+  Address promise_hook_address() {
+    return reinterpret_cast<Address>(&promise_hook_);
   }
 
-  Address promise_hook_or_debug_is_active_or_async_event_delegate_address() {
-    return reinterpret_cast<Address>(
-        &promise_hook_or_debug_is_active_or_async_event_delegate_);
+  Address async_event_delegate_address() {
+    return reinterpret_cast<Address>(&async_event_delegate_);
   }
 
   Address handle_scope_implementer_address() {
@@ -1469,6 +1513,9 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   void SetPromiseHook(PromiseHook hook);
   void RunPromiseHook(PromiseHookType type, Handle<JSPromise> promise,
                       Handle<Object> parent);
+  void RunAllPromiseHooks(PromiseHookType type, Handle<JSPromise> promise,
+                          Handle<Object> parent);
+  void UpdatePromiseHookProtector();
   void PromiseHookStateUpdated();
 
   void AddDetachedContext(Handle<Context> context);
@@ -1657,8 +1704,9 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   }
 
 #if V8_ENABLE_WEBASSEMBLY
-  wasm::WasmEngine* wasm_engine() const { return wasm_engine_.get(); }
-  void SetWasmEngine(std::shared_ptr<wasm::WasmEngine> engine);
+  // TODO(wasm): Replace all uses by {WasmEngine::GetWasmEngine}?
+  wasm::WasmEngine* wasm_engine() const { return wasm_engine_; }
+  void SetWasmEngine(wasm::WasmEngine* engine);
 
   void AddSharedWasmMemory(Handle<WasmMemoryObject> memory_object);
 #endif  // V8_ENABLE_WEBASSEMBLY
@@ -1692,6 +1740,9 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   MaybeLocal<v8::Context> GetContextFromRecorderContextId(
       v8::metrics::Recorder::ContextId id);
 
+  void UpdateLongTaskStats();
+  v8::metrics::LongTaskStats* GetCurrentLongTaskStats();
+
   LocalIsolate* main_thread_local_isolate() {
     return main_thread_local_isolate_.get();
   }
@@ -1715,8 +1766,24 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   }
 #endif
 
+  struct PromiseHookFields {
+    using HasContextPromiseHook = base::BitField<bool, 0, 1>;
+    using HasIsolatePromiseHook = HasContextPromiseHook::Next<bool, 1>;
+    using HasAsyncEventDelegate = HasIsolatePromiseHook::Next<bool, 1>;
+    using IsDebugActive = HasAsyncEventDelegate::Next<bool, 1>;
+  };
+
+  bool is_shared() { return is_shared_; }
+  Isolate* shared_isolate() { return shared_isolate_; }
+
+  void AttachToSharedIsolate(Isolate* shared);
+  void DetachFromSharedIsolate();
+
+  bool HasClientIsolates() const { return client_isolate_head_; }
+
  private:
-  explicit Isolate(std::unique_ptr<IsolateAllocator> isolate_allocator);
+  explicit Isolate(std::unique_ptr<IsolateAllocator> isolate_allocator,
+                   bool is_shared);
   ~Isolate();
 
   bool Init(SnapshotData* startup_snapshot_data,
@@ -1727,6 +1794,10 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   void InitializeCodeRanges();
   void AddCodeMemoryRange(MemoryRange range);
 
+  // Common method to create an Isolate used by Isolate::New() and
+  // Isolate::NewShared().
+  static Isolate* Allocate(bool is_shared);
+
   static void RemoveContextIdCallback(const v8::WeakCallbackInfo<void>& data);
 
   class ThreadDataTable {
@@ -1798,6 +1869,16 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   void RunPromiseHookForAsyncEventDelegate(PromiseHookType type,
                                            Handle<JSPromise> promise);
 
+  bool HasIsolatePromiseHooks() const {
+    return PromiseHookFields::HasIsolatePromiseHook::decode(
+        promise_hook_flags_);
+  }
+
+  bool HasAsyncEventDelegate() const {
+    return PromiseHookFields::HasAsyncEventDelegate::decode(
+        promise_hook_flags_);
+  }
+
   const char* RAILModeName(RAILMode rail_mode) const {
     switch (rail_mode) {
       case PERFORMANCE_RESPONSE:
@@ -1817,6 +1898,10 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   // Returns the Exception sentinel.
   Object ThrowInternal(Object exception, MessageLocation* location);
 
+  // Methods for appending and removing to/from client isolates list.
+  void AppendAsClientIsolate(Isolate* client);
+  void RemoveAsClientIsolate(Isolate* client);
+
   // This class contains a collection of data accessible from both C++ runtime
   // and compiled code (including assembly stubs, builtins, interpreter bytecode
   // handlers and optimized code).
@@ -1862,6 +1947,7 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   GlobalHandles* global_handles_ = nullptr;
   EternalHandles* eternal_handles_ = nullptr;
   ThreadManager* thread_manager_ = nullptr;
+  bigint::Processor* bigint_processor_ = nullptr;
   RuntimeState runtime_state_;
   Builtins builtins_;
   SetupIsolateDelegate* setup_delegate_ = nullptr;
@@ -2021,6 +2107,9 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
       Persistent<v8::Context, v8::CopyablePersistentTraits<v8::Context>>>
       recorder_context_id_map_;
 
+  size_t last_long_task_stats_counter_ = 0;
+  v8::metrics::LongTaskStats long_task_stats_;
+
   std::vector<Object> startup_object_cache_;
 
   // Used during builtins compilation to build the builtins constants table,
@@ -2050,8 +2139,7 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   debug::ConsoleDelegate* console_delegate_ = nullptr;
 
   debug::AsyncEventDelegate* async_event_delegate_ = nullptr;
-  bool promise_hook_or_async_event_delegate_ = false;
-  bool promise_hook_or_debug_is_active_or_async_event_delegate_ = false;
+  uint32_t promise_hook_flags_ = 0;
   int async_task_count_ = 0;
 
   std::unique_ptr<LocalIsolate> main_thread_local_isolate_;
@@ -2069,7 +2157,7 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   size_t elements_deletion_counter_ = 0;
 
 #if V8_ENABLE_WEBASSEMBLY
-  std::shared_ptr<wasm::WasmEngine> wasm_engine_;
+  wasm::WasmEngine* wasm_engine_ = nullptr;
 #endif  // V8_ENABLE_WEBASSEMBLY
 
   std::unique_ptr<TracingCpuProfilerImpl> tracing_cpu_profiler_;
@@ -2088,6 +2176,23 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   base::Mutex thread_data_table_mutex_;
   ThreadDataTable thread_data_table_;
 
+  // Set to true if this isolate is used as shared heap.
+  const bool is_shared_;
+
+  // Stores the shared isolate for this client isolate. nullptr for shared
+  // isolates or when no shared isolate is used.
+  Isolate* shared_isolate_ = nullptr;
+
+  // A shared isolate will use these two fields to track all its client
+  // isolates.
+  base::Mutex client_isolate_mutex_;
+  Isolate* client_isolate_head_ = nullptr;
+
+  // Used to form a linked list of all client isolates. Protected by
+  // client_isolate_mutex_.
+  Isolate* prev_client_isolate_ = nullptr;
+  Isolate* next_client_isolate_ = nullptr;
+
   // A signal-safe vector of heap pages containing code. Used with the
   // v8::Unwinder API.
   std::atomic<std::vector<MemoryRange>*> code_pages_{nullptr};
diff --git a/chromium/v8/src/execution/local-isolate-inl.h b/chromium/v8/src/execution/local-isolate-inl.h
index 318cc10fa4a..59a7b1f5e42 100644
--- a/chromium/v8/src/execution/local-isolate-inl.h
+++ b/chromium/v8/src/execution/local-isolate-inl.h
@@ -12,7 +12,7 @@
 namespace v8 {
 namespace internal {
 
-Address LocalIsolate::isolate_root() const { return isolate_->isolate_root(); }
+Address LocalIsolate::cage_base() const { return isolate_->cage_base(); }
 ReadOnlyHeap* LocalIsolate::read_only_heap() const {
   return isolate_->read_only_heap();
 }
diff --git a/chromium/v8/src/execution/local-isolate.h b/chromium/v8/src/execution/local-isolate.h
index 91192d5f0f1..5392534d667 100644
--- a/chromium/v8/src/execution/local-isolate.h
+++ b/chromium/v8/src/execution/local-isolate.h
@@ -50,7 +50,7 @@ class V8_EXPORT_PRIVATE LocalIsolate final : private HiddenLocalFactory {
 
   LocalHeap* heap() { return &heap_; }
 
-  inline Address isolate_root() const;
+  inline Address cage_base() const;
   inline ReadOnlyHeap* read_only_heap() const;
   inline Object root(RootIndex index) const;
 
@@ -62,8 +62,7 @@ class V8_EXPORT_PRIVATE LocalIsolate final : private HiddenLocalFactory {
   v8::internal::LocalFactory* factory() {
     // Upcast to the privately inherited base-class using c-style casts to avoid
     // undefined behavior (as static_cast cannot cast across private bases).
-    // NOLINTNEXTLINE (google-readability-casting)
-    return (v8::internal::LocalFactory*)this;  // NOLINT(readability/casting)
+    return (v8::internal::LocalFactory*)this;
   }
 
   bool has_pending_exception() const { return false; }
diff --git a/chromium/v8/src/execution/messages.cc b/chromium/v8/src/execution/messages.cc
index a8b7ad23ca4..f72ff6b02c3 100644
--- a/chromium/v8/src/execution/messages.cc
+++ b/chromium/v8/src/execution/messages.cc
@@ -186,8 +186,7 @@ void MessageHandler::ReportMessageNoExceptions(
           FUNCTION_CAST<v8::MessageCallback>(callback_obj.foreign_address());
       Handle<Object> callback_data(listener.get(1), isolate);
       {
-        RuntimeCallTimerScope timer(
-            isolate, RuntimeCallCounterId::kMessageListenerCallback);
+        RCS_SCOPE(isolate, RuntimeCallCounterId::kMessageListenerCallback);
         // Do not allow exceptions to propagate.
         v8::TryCatch try_catch(reinterpret_cast<v8::Isolate*>(isolate));
         callback(api_message_obj, callback_data->IsUndefined(isolate)
@@ -483,7 +482,8 @@ MaybeHandle<String> MessageFormatter::Format(Isolate* isolate,
 MaybeHandle<JSObject> ErrorUtils::Construct(Isolate* isolate,
                                             Handle<JSFunction> target,
                                             Handle<Object> new_target,
-                                            Handle<Object> message) {
+                                            Handle<Object> message,
+                                            Handle<Object> options) {
   FrameSkipMode mode = SKIP_FIRST;
   Handle<Object> caller;
 
@@ -495,15 +495,15 @@ MaybeHandle<JSObject> ErrorUtils::Construct(Isolate* isolate,
     caller = new_target;
   }
 
-  return ErrorUtils::Construct(isolate, target, new_target, message, mode,
-                               caller,
+  return ErrorUtils::Construct(isolate, target, new_target, message, options,
+                               mode, caller,
                                ErrorUtils::StackTraceCollection::kDetailed);
 }
 
 MaybeHandle<JSObject> ErrorUtils::Construct(
     Isolate* isolate, Handle<JSFunction> target, Handle<Object> new_target,
-    Handle<Object> message, FrameSkipMode mode, Handle<Object> caller,
-    StackTraceCollection stack_trace_collection) {
+    Handle<Object> message, Handle<Object> options, FrameSkipMode mode,
+    Handle<Object> caller, StackTraceCollection stack_trace_collection) {
   if (FLAG_correctness_fuzzer_suppressions) {
     // Abort range errors in correctness fuzzing, as their causes differ
     // accross correctness-fuzzing scenarios.
@@ -536,7 +536,6 @@ MaybeHandle<JSObject> ErrorUtils::Construct(
   //     true, [[Enumerable]]: false, [[Configurable]]: true}.
   //  c. Perform ! DefinePropertyOrThrow(O, "message", msgDesc).
   // 4. Return O.
-
   if (!message->IsUndefined(isolate)) {
     Handle<String> msg_string;
     ASSIGN_RETURN_ON_EXCEPTION(isolate, msg_string,
@@ -548,6 +547,31 @@ MaybeHandle<JSObject> ErrorUtils::Construct(
         JSObject);
   }
 
+  if (FLAG_harmony_error_cause && !options->IsUndefined(isolate)) {
+    // If Type(options) is Object and ? HasProperty(options, "cause") then
+    //   a. Let cause be ? Get(options, "cause").
+    //   b. Perform ! CreateNonEnumerableDataPropertyOrThrow(O, "cause", cause).
+    Handle<Name> cause_string = isolate->factory()->cause_string();
+    if (options->IsJSReceiver()) {
+      Handle<JSReceiver> js_options = Handle<JSReceiver>::cast(options);
+      Maybe<bool> has_cause = JSObject::HasProperty(js_options, cause_string);
+      if (has_cause.IsNothing()) {
+        DCHECK((isolate)->has_pending_exception());
+        return MaybeHandle<JSObject>();
+      }
+      if (has_cause.ToChecked()) {
+        Handle<Object> cause;
+        ASSIGN_RETURN_ON_EXCEPTION(
+            isolate, cause,
+            JSObject::GetProperty(isolate, js_options, cause_string), JSObject);
+        RETURN_ON_EXCEPTION(isolate,
+                            JSObject::SetOwnPropertyIgnoreAttributes(
+                                err, cause_string, cause, DONT_ENUM),
+                            JSObject);
+      }
+    }
+  }
+
   switch (stack_trace_collection) {
     case StackTraceCollection::kDetailed:
       RETURN_ON_EXCEPTION(
@@ -676,14 +700,15 @@ Handle<JSObject> ErrorUtils::MakeGenericError(
     isolate->clear_pending_exception();
   }
   Handle<String> msg = DoFormatMessage(isolate, index, arg0, arg1, arg2);
+  Handle<Object> options = isolate->factory()->undefined_value();
 
   DCHECK(mode != SKIP_UNTIL_SEEN);
 
   Handle<Object> no_caller;
   // The call below can't fail because constructor is a builtin.
   DCHECK(constructor->shared().HasBuiltinId());
-  return ErrorUtils::Construct(isolate, constructor, constructor, msg, mode,
-                               no_caller, StackTraceCollection::kDetailed)
+  return ErrorUtils::Construct(isolate, constructor, constructor, msg, options,
+                               mode, no_caller, StackTraceCollection::kDetailed)
       .ToHandleChecked();
 }
 
diff --git a/chromium/v8/src/execution/messages.h b/chromium/v8/src/execution/messages.h
index 43f99d17972..ad2d76f59e2 100644
--- a/chromium/v8/src/execution/messages.h
+++ b/chromium/v8/src/execution/messages.h
@@ -77,11 +77,12 @@ class ErrorUtils : public AllStatic {
   static MaybeHandle<JSObject> Construct(Isolate* isolate,
                                          Handle<JSFunction> target,
                                          Handle<Object> new_target,
-                                         Handle<Object> message);
+                                         Handle<Object> message,
+                                         Handle<Object> options);
   static MaybeHandle<JSObject> Construct(
       Isolate* isolate, Handle<JSFunction> target, Handle<Object> new_target,
-      Handle<Object> message, FrameSkipMode mode, Handle<Object> caller,
-      StackTraceCollection stack_trace_collection);
+      Handle<Object> message, Handle<Object> options, FrameSkipMode mode,
+      Handle<Object> caller, StackTraceCollection stack_trace_collection);
 
   static MaybeHandle<String> ToString(Isolate* isolate, Handle<Object> recv);
 
diff --git a/chromium/v8/src/execution/microtask-queue.cc b/chromium/v8/src/execution/microtask-queue.cc
index 496737b03a4..cae642e2c97 100644
--- a/chromium/v8/src/execution/microtask-queue.cc
+++ b/chromium/v8/src/execution/microtask-queue.cc
@@ -113,6 +113,16 @@ void MicrotaskQueue::EnqueueMicrotask(Microtask microtask) {
 void MicrotaskQueue::PerformCheckpoint(v8::Isolate* v8_isolate) {
   if (!IsRunningMicrotasks() && !GetMicrotasksScopeDepth() &&
       !HasMicrotasksSuppressions()) {
+    std::unique_ptr<MicrotasksScope> microtasks_scope;
+    if (microtasks_policy_ == v8::MicrotasksPolicy::kScoped) {
+      // If we're using microtask scopes to schedule microtask execution, V8
+      // API calls will check that there's always a microtask scope on the
+      // stack. As the microtasks we're about to execute could invoke embedder
+      // callbacks which then calls back into V8, we create an artificial
+      // microtask scope here to avoid running into the CallDepthScope check.
+      microtasks_scope.reset(new v8::MicrotasksScope(
+          v8_isolate, this, v8::MicrotasksScope::kDoNotRunMicrotasks));
+    }
     Isolate* isolate = reinterpret_cast<Isolate*>(v8_isolate);
     RunMicrotasks(isolate);
     isolate->ClearKeptObjects();
diff --git a/chromium/v8/src/execution/mips/simulator-mips.cc b/chromium/v8/src/execution/mips/simulator-mips.cc
index ca402dca040..3c9c2523102 100644
--- a/chromium/v8/src/execution/mips/simulator-mips.cc
+++ b/chromium/v8/src/execution/mips/simulator-mips.cc
@@ -47,7 +47,7 @@ uint32_t get_fcsr_condition_bit(uint32_t cc) {
 // SScanF not being implemented in a platform independent was through
 // ::v8::internal::OS in the same way as SNPrintF is that the Windows C Run-Time
 // Library does not provide vsscanf.
-#define SScanF sscanf  // NOLINT
+#define SScanF sscanf
 
 // The MipsDebugger class is used by the simulator while debugging simulated
 // code.
diff --git a/chromium/v8/src/execution/mips64/simulator-mips64.cc b/chromium/v8/src/execution/mips64/simulator-mips64.cc
index 198022b3a4e..2ab945f88de 100644
--- a/chromium/v8/src/execution/mips64/simulator-mips64.cc
+++ b/chromium/v8/src/execution/mips64/simulator-mips64.cc
@@ -64,7 +64,7 @@ static int64_t MultiplyHighSigned(int64_t u, int64_t v) {
 // SScanF not being implemented in a platform independent was through
 // ::v8::internal::OS in the same way as SNPrintF is that the Windows C Run-Time
 // Library does not provide vsscanf.
-#define SScanF sscanf  // NOLINT
+#define SScanF sscanf
 
 // The MipsDebugger class is used by the simulator while debugging simulated
 // code.
diff --git a/chromium/v8/src/execution/ppc/simulator-ppc.cc b/chromium/v8/src/execution/ppc/simulator-ppc.cc
index c812af360ea..f9b9552433e 100644
--- a/chromium/v8/src/execution/ppc/simulator-ppc.cc
+++ b/chromium/v8/src/execution/ppc/simulator-ppc.cc
@@ -39,7 +39,7 @@ DEFINE_LAZY_LEAKY_OBJECT_GETTER(Simulator::GlobalMonitor,
 // SScanF not being implemented in a platform independent way through
 // ::v8::internal::OS in the same way as SNPrintF is that the
 // Windows C Run-Time Library does not provide vsscanf.
-#define SScanF sscanf  // NOLINT
+#define SScanF sscanf
 
 // The PPCDebugger class is used by the simulator while debugging simulated
 // PowerPC code.
@@ -1138,7 +1138,7 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
         SimulatorRuntimeDirectGetterCall target =
             reinterpret_cast<SimulatorRuntimeDirectGetterCall>(external);
         if (!ABI_PASSES_HANDLES_IN_REGS) {
-          arg[0] = *(reinterpret_cast<intptr_t*>(arg[0]));
+          arg[0] = bit_cast<intptr_t>(arg[0]);
         }
         target(arg[0], arg[1]);
       } else if (redirection->type() ==
@@ -1157,7 +1157,7 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
         SimulatorRuntimeProfilingGetterCall target =
             reinterpret_cast<SimulatorRuntimeProfilingGetterCall>(external);
         if (!ABI_PASSES_HANDLES_IN_REGS) {
-          arg[0] = *(reinterpret_cast<intptr_t*>(arg[0]));
+          arg[0] = bit_cast<intptr_t>(arg[0]);
         }
         target(arg[0], arg[1], Redirection::ReverseRedirection(arg[2]));
       } else {
@@ -2464,6 +2464,10 @@ void Simulator::ExecuteGeneric(Instruction* instr) {
         DCHECK_EQ(instr->Bit(0), 1);
         set_simd_register_by_lane<int64_t>(frt, 0,
                                            static_cast<int64_t>(ra_val));
+        // Low 64 bits of the result is undefined,
+        // Which is simulated here by adding random bits.
+        set_simd_register_by_lane<int64_t>(
+            frt, 1, static_cast<int64_t>(0x123456789ABCD));
       }
       break;
     }
@@ -3913,8 +3917,7 @@ void Simulator::ExecuteGeneric(Instruction* instr) {
     case STVX: {
       DECODE_VX_INSTRUCTION(vrs, ra, rb, S)
       GET_ADDRESS(ra, rb, ra_val, rb_val)
-      __int128 vrs_val =
-          *(reinterpret_cast<__int128*>(get_simd_register(vrs).int8));
+      __int128 vrs_val = bit_cast<__int128>(get_simd_register(vrs).int8);
       WriteQW((ra_val + rb_val) & 0xFFFFFFFFFFFFFFF0, vrs_val);
       break;
     }
@@ -3926,6 +3929,14 @@ void Simulator::ExecuteGeneric(Instruction* instr) {
           xt, 1, ReadDW(ra_val + rb_val + kSystemPointerSize));
       break;
     }
+    case LXVX: {
+      DECODE_VX_INSTRUCTION(vrt, ra, rb, T)
+      GET_ADDRESS(ra, rb, ra_val, rb_val)
+      intptr_t addr = ra_val + rb_val;
+      simdr_t* ptr = reinterpret_cast<simdr_t*>(addr);
+      set_simd_register(vrt, *ptr);
+      break;
+    }
     case STXVD: {
       DECODE_VX_INSTRUCTION(xs, ra, rb, S)
       GET_ADDRESS(ra, rb, ra_val, rb_val)
@@ -3934,6 +3945,14 @@ void Simulator::ExecuteGeneric(Instruction* instr) {
               get_simd_register_by_lane<int64_t>(xs, 1));
       break;
     }
+    case STXVX: {
+      DECODE_VX_INSTRUCTION(vrs, ra, rb, S)
+      GET_ADDRESS(ra, rb, ra_val, rb_val)
+      intptr_t addr = ra_val + rb_val;
+      __int128 vrs_val = bit_cast<__int128>(get_simd_register(vrs).int8);
+      WriteQW(addr, vrs_val);
+      break;
+    }
     case LXSIBZX: {
       DECODE_VX_INSTRUCTION(xt, ra, rb, T)
       GET_ADDRESS(ra, rb, ra_val, rb_val)
@@ -3982,6 +4001,15 @@ void Simulator::ExecuteGeneric(Instruction* instr) {
       WriteDW(ra_val + rb_val, get_simd_register_by_lane<int64_t>(xs, 0));
       break;
     }
+    case XXBRQ: {
+      int t = instr->RTValue();
+      int b = instr->RBValue();
+      __int128 xb_val = bit_cast<__int128>(get_simd_register(b).int8);
+      __int128 xb_val_reversed = __builtin_bswap128(xb_val);
+      simdr_t simdr_xb = bit_cast<simdr_t>(xb_val_reversed);
+      set_simd_register(t, simdr_xb);
+      break;
+    }
 #define VSPLT(type)                                       \
   uint32_t uim = instr->Bits(20, 16);                     \
   int vrt = instr->RTValue();                             \
@@ -4749,7 +4777,7 @@ void Simulator::ExecuteGeneric(Instruction* instr) {
       DECODE_VX_INSTRUCTION(t, a, b, T)
       uint16_t result_bits = 0;
       unsigned __int128 src_bits =
-          *(reinterpret_cast<__int128*>(get_simd_register(a).int8));
+          bit_cast<__int128>(get_simd_register(a).int8);
       for (int i = 0; i < kSimd128Size; i++) {
         result_bits <<= 1;
         uint8_t selected_bit_index = get_simd_register_by_lane<uint8_t>(b, i);
@@ -4871,6 +4899,14 @@ void Simulator::ExecuteGeneric(Instruction* instr) {
       VECTOR_UNARY_OP(float, base::RecipSqrt)
       break;
     }
+    case VNEGW: {
+      VECTOR_UNARY_OP(int32_t, -)
+      break;
+    }
+    case VNEGD: {
+      VECTOR_UNARY_OP(int64_t, -)
+      break;
+    }
 #undef VECTOR_UNARY_OP
 #define VECTOR_ROUNDING_AVERAGE(intermediate_type, result_type)              \
   DECODE_VX_INSTRUCTION(t, a, b, T)                                          \
@@ -4911,7 +4947,7 @@ void Simulator::ExecuteGeneric(Instruction* instr) {
       break;
     }
   }
-}  // NOLINT
+}
 
 void Simulator::Trace(Instruction* instr) {
   disasm::NameConverter converter;
@@ -4981,7 +5017,7 @@ void Simulator::CallInternal(Address entry) {
   // Prepare to execute the code at entry
   if (ABI_USES_FUNCTION_DESCRIPTORS) {
     // entry is the function descriptor
-    set_pc(*(reinterpret_cast<intptr_t*>(entry)));
+    set_pc(*(bit_cast<intptr_t*>(entry)));
   } else {
     // entry is the instruction address
     set_pc(static_cast<intptr_t>(entry));
diff --git a/chromium/v8/src/execution/ppc/simulator-ppc.h b/chromium/v8/src/execution/ppc/simulator-ppc.h
index bacd844be05..2dea5c00ca2 100644
--- a/chromium/v8/src/execution/ppc/simulator-ppc.h
+++ b/chromium/v8/src/execution/ppc/simulator-ppc.h
@@ -321,6 +321,18 @@ class Simulator : public SimulatorBase {
     }
   }
 
+  // Byte Reverse.
+  static inline __uint128_t __builtin_bswap128(__uint128_t v) {
+    union {
+      uint64_t u64[2];
+      __uint128_t u128;
+    } res, val;
+    val.u128 = v;
+    res.u64[0] = __builtin_bswap64(val.u64[1]);
+    res.u64[1] = __builtin_bswap64(val.u64[0]);
+    return res.u128;
+  }
+
 #define RW_VAR_LIST(V)      \
   V(QWU, unsigned __int128) \
   V(QW, __int128)           \
diff --git a/chromium/v8/src/execution/protectors.h b/chromium/v8/src/execution/protectors.h
index c4ca49d948a..aa89275c110 100644
--- a/chromium/v8/src/execution/protectors.h
+++ b/chromium/v8/src/execution/protectors.h
@@ -26,6 +26,8 @@ class Protectors : public AllStatic {
     is_concat_spreadable_protector)                                           \
   V(NoElements, NoElementsProtector, no_elements_protector)                   \
                                                                               \
+  V(MegaDOM, MegaDOMProtector, mega_dom_protector)                            \
+                                                                              \
   /* The MapIterator protector protects the original iteration behaviors   */ \
   /* of Map.prototype.keys(), Map.prototype.values(), and                  */ \
   /* Set.prototype.entries(). It does not protect the original iteration   */ \
diff --git a/chromium/v8/src/execution/riscv64/simulator-riscv64.cc b/chromium/v8/src/execution/riscv64/simulator-riscv64.cc
index 1d38d8c0ca0..e8f16155bef 100644
--- a/chromium/v8/src/execution/riscv64/simulator-riscv64.cc
+++ b/chromium/v8/src/execution/riscv64/simulator-riscv64.cc
@@ -93,7 +93,7 @@ static inline int32_t get_ebreak_code(Instruction* instr) {
 // SScanF not being implemented in a platform independent was through
 // ::v8::internal::OS in the same way as SNPrintF is that the Windows C Run-Time
 // Library does not provide vsscanf.
-#define SScanF sscanf  // NOLINT
+#define SScanF sscanf
 
 // The RiscvDebugger class is used by the simulator while debugging simulated
 // code.
@@ -261,6 +261,10 @@ void RiscvDebugger::Debug() {
       disasm::Disassembler dasm(converter);
       // Use a reasonably large buffer.
       v8::internal::EmbeddedVector<char, 256> buffer;
+      const char* name = sim_->builtins_.Lookup((Address)sim_->get_pc());
+      if (name != nullptr) {
+        PrintF("Call builtin:  %s\n", name);
+      }
       dasm.InstructionDecode(buffer, reinterpret_cast<byte*>(sim_->get_pc()));
       PrintF("  0x%016" PRIx64 "   %s\n", sim_->get_pc(), buffer.begin());
       last_pc = sim_->get_pc();
@@ -785,7 +789,7 @@ void Simulator::CheckICache(base::CustomMatcherHashMap* i_cache,
   }
 }
 
-Simulator::Simulator(Isolate* isolate) : isolate_(isolate) {
+Simulator::Simulator(Isolate* isolate) : isolate_(isolate), builtins_(isolate) {
   // Set up simulator support first. Some of this information is needed to
   // setup the architecture state.
   stack_size_ = FLAG_sim_stack_size * KB;
@@ -1062,7 +1066,7 @@ T Simulator::FMaxMinHelper(T a, T b, MaxMinKind kind) {
 
   T result = 0;
   if (std::isnan(a) && std::isnan(b)) {
-    result = a;
+    result = std::numeric_limits<float>::quiet_NaN();
   } else if (std::isnan(a)) {
     result = b;
   } else if (std::isnan(b)) {
@@ -1101,7 +1105,7 @@ int64_t Simulator::get_pc() const { return registers_[pc]; }
 
 // TODO(plind): refactor this messy debug code when we do unaligned access.
 void Simulator::DieOrDebug() {
-  if ((1)) {  // Flag for this was removed.
+  if (FLAG_riscv_trap_to_simulator_debugger) {
     RiscvDebugger dbg(this);
     dbg.Debug();
   } else {
@@ -2819,6 +2823,33 @@ void Simulator::DecodeRVIType() {
       // Note: No need to shift 2 for JALR's imm12, but set lowest bit to 0.
       int64_t next_pc = (rs1() + imm12()) & ~reg_t(1);
       set_pc(next_pc);
+      if (::v8::internal::FLAG_trace_sim) {
+        if ((rs1_reg() != ra || imm12() != 0)) {
+          const char* name = builtins_.Lookup((Address)next_pc);
+          if (name != nullptr) {
+            int64_t arg0 = get_register(a0);
+            int64_t arg1 = get_register(a1);
+            int64_t arg2 = get_register(a2);
+            int64_t arg3 = get_register(a3);
+            int64_t arg4 = get_register(a4);
+            int64_t arg5 = get_register(a5);
+            int64_t arg6 = get_register(a6);
+            int64_t arg7 = get_register(a7);
+            int64_t* stack_pointer =
+                reinterpret_cast<int64_t*>(get_register(sp));
+            int64_t arg8 = stack_pointer[0];
+            int64_t arg9 = stack_pointer[1];
+            PrintF(
+                "Call to Builtin at %s "
+                "a0 %08" PRIx64 " ,a1 %08" PRIx64 " ,a2 %08" PRIx64
+                " ,a3 %08" PRIx64 " ,a4 %08" PRIx64 " ,a5 %08" PRIx64
+                " ,a6 %08" PRIx64 " ,a7 %08" PRIx64 " ,0(sp) %08" PRIx64
+                " ,8(sp) %08" PRIx64 " ,sp %08" PRIx64 ",fp %08" PRIx64 " \n",
+                name, arg0, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8,
+                arg9, get_register(sp), get_register(fp));
+          }
+        }
+      }
       break;
     }
     case RO_LB: {
diff --git a/chromium/v8/src/execution/riscv64/simulator-riscv64.h b/chromium/v8/src/execution/riscv64/simulator-riscv64.h
index e51ec6472c2..e5647b2c43f 100644
--- a/chromium/v8/src/execution/riscv64/simulator-riscv64.h
+++ b/chromium/v8/src/execution/riscv64/simulator-riscv64.h
@@ -706,6 +706,7 @@ class Simulator : public SimulatorBase {
   char* last_debugger_input_;
 
   v8::internal::Isolate* isolate_;
+  v8::internal::Builtins builtins_;
 
   // Stop is disabled if bit 31 is set.
   static const uint32_t kStopDisabledBit = 1 << 31;
diff --git a/chromium/v8/src/execution/runtime-profiler.cc b/chromium/v8/src/execution/runtime-profiler.cc
index 013d7c0e9f7..05e828da50d 100644
--- a/chromium/v8/src/execution/runtime-profiler.cc
+++ b/chromium/v8/src/execution/runtime-profiler.cc
@@ -107,20 +107,8 @@ void TraceHeuristicOptimizationDisallowed(JSFunction function) {
   }
 }
 
-// TODO(jgruber): Remove this once we include this tracing with --trace-opt.
-void TraceNCIRecompile(JSFunction function, OptimizationReason reason) {
-  if (FLAG_trace_turbo_nci) {
-    StdoutStream os;
-    os << "NCI tierup mark: " << Brief(function) << ", "
-       << OptimizationReasonToString(reason) << std::endl;
-  }
-}
-
 void TraceRecompile(JSFunction function, OptimizationReason reason,
                     CodeKind code_kind, Isolate* isolate) {
-  if (code_kind == CodeKind::NATIVE_CONTEXT_INDEPENDENT) {
-    TraceNCIRecompile(function, reason);
-  }
   if (FLAG_trace_opt) {
     CodeTracer::Scope scope(isolate->GetCodeTracer());
     PrintF(scope.file(), "[marking ");
@@ -187,8 +175,7 @@ void RuntimeProfiler::MaybeOptimizeFrame(JSFunction function,
 
   if (function.shared().optimization_disabled()) return;
 
-  // Note: We currently do not trigger OSR compilation from NCI or TP code.
-  // TODO(jgruber,v8:8888): But we should.
+  // Note: We currently do not trigger OSR compilation from TP code.
   if (frame->is_unoptimized()) {
     if (FLAG_always_osr) {
       AttemptOnStackReplacement(UnoptimizedFrame::cast(frame),
diff --git a/chromium/v8/src/execution/s390/simulator-s390.cc b/chromium/v8/src/execution/s390/simulator-s390.cc
index 435082a3b9d..93250b45f47 100644
--- a/chromium/v8/src/execution/s390/simulator-s390.cc
+++ b/chromium/v8/src/execution/s390/simulator-s390.cc
@@ -34,7 +34,7 @@ namespace internal {
 // SScanF not being implemented in a platform independent way through
 // ::v8::internal::OS in the same way as SNPrintF is that the
 // Windows C Run-Time Library does not provide vsscanf.
-#define SScanF sscanf  // NOLINT
+#define SScanF sscanf
 
 const Simulator::fpr_t Simulator::fp_zero;
 
@@ -772,6 +772,8 @@ void Simulator::EvalTableInit() {
   V(vsum, VSUM, 0xE764)   /* type = VRR_C VECTOR SUM ACROSS WORD  */           \
   V(vsumg, VSUMG, 0xE765) /* type = VRR_C VECTOR SUM ACROSS DOUBLEWORD  */     \
   V(vpk, VPK, 0xE794)     /* type = VRR_C VECTOR PACK  */                      \
+  V(vmrl, VMRL, 0xE760)   /* type = VRR_C VECTOR MERGE LOW */                  \
+  V(vmrh, VMRH, 0xE761)   /* type = VRR_C VECTOR MERGE HIGH */                 \
   V(vpks, VPKS, 0xE797)   /* type = VRR_B VECTOR PACK SATURATE  */             \
   V(vpkls, VPKLS, 0xE795) /* type = VRR_B VECTOR PACK LOGICAL SATURATE  */     \
   V(vupll, VUPLL, 0xE7D4) /* type = VRR_A VECTOR UNPACK LOGICAL LOW  */        \
@@ -1558,7 +1560,7 @@ void Simulator::EvalTableInit() {
   EvalTable[CZXT] = &Simulator::Evaluate_CZXT;
   EvalTable[CDZT] = &Simulator::Evaluate_CDZT;
   EvalTable[CXZT] = &Simulator::Evaluate_CXZT;
-}  // NOLINT
+}
 
 Simulator::Simulator(Isolate* isolate) : isolate_(isolate) {
   static base::OnceType once = V8_ONCE_INIT;
@@ -2000,8 +2002,8 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
           (redirection->type() == ExternalReference::BUILTIN_FP_INT_CALL);
 
       // Place the return address on the stack, making the call GC safe.
-      *reinterpret_cast<intptr_t*>(get_register(sp) +
-                                   kStackFrameRASlot * kSystemPointerSize) =
+      *bit_cast<intptr_t*>(get_register(sp) +
+                           kStackFrameRASlot * kSystemPointerSize) =
           get_register(r14);
 
       intptr_t external =
@@ -2141,7 +2143,7 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
         SimulatorRuntimeDirectGetterCall target =
             reinterpret_cast<SimulatorRuntimeDirectGetterCall>(external);
         if (!ABI_PASSES_HANDLES_IN_REGS) {
-          arg[0] = *(reinterpret_cast<intptr_t*>(arg[0]));
+          arg[0] = bit_cast<intptr_t>(arg[0]);
         }
         target(arg[0], arg[1]);
       } else if (redirection->type() ==
@@ -2160,7 +2162,7 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
         SimulatorRuntimeProfilingGetterCall target =
             reinterpret_cast<SimulatorRuntimeProfilingGetterCall>(external);
         if (!ABI_PASSES_HANDLES_IN_REGS) {
-          arg[0] = *(reinterpret_cast<intptr_t*>(arg[0]));
+          arg[0] = bit_cast<intptr_t>(arg[0]);
         }
         target(arg[0], arg[1], Redirection::ReverseRedirection(arg[2]));
       } else {
@@ -2268,7 +2270,7 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
         //         }
         // #endif
       }
-      int64_t saved_lr = *reinterpret_cast<intptr_t*>(
+      int64_t saved_lr = *bit_cast<intptr_t*>(
           get_register(sp) + kStackFrameRASlot * kSystemPointerSize);
 #if (!V8_TARGET_ARCH_S390X && V8_HOST_ARCH_S390)
       // On zLinux-31, the saved_lr might be tagged with a high bit of 1.
@@ -2485,7 +2487,7 @@ void Simulator::CallInternal(Address entry, int reg_arg_count) {
   // Prepare to execute the code at entry
   if (ABI_USES_FUNCTION_DESCRIPTORS) {
     // entry is the function descriptor
-    set_pc(*(reinterpret_cast<intptr_t*>(entry)));
+    set_pc(*(bit_cast<intptr_t*>(entry)));
   } else {
     // entry is the instruction address
     set_pc(static_cast<intptr_t>(entry));
@@ -2607,7 +2609,7 @@ intptr_t Simulator::CallImpl(Address entry, int argument_count,
 // Prepare to execute the code at entry
 #if ABI_USES_FUNCTION_DESCRIPTORS
   // entry is the function descriptor
-  set_pc(*(reinterpret_cast<intptr_t*>(entry)));
+  set_pc(*(bit_cast<intptr_t*>(entry)));
 #else
   // entry is the instruction address
   set_pc(static_cast<intptr_t>(entry));
@@ -3134,12 +3136,12 @@ EVALUATE(VLREP) {
   DCHECK_OPCODE(VLREP);
   DECODE_VRX_INSTRUCTION(r1, x2, b2, d2, m3);
   intptr_t addr = GET_ADDRESS(x2, b2, d2);
-#define CASE(i, type)                                                         \
-  case i: {                                                                   \
-    FOR_EACH_LANE(j, type) {                                                  \
-      set_simd_register_by_lane<type>(r1, j, *reinterpret_cast<type*>(addr)); \
-    }                                                                         \
-    break;                                                                    \
+#define CASE(i, type)                                                 \
+  case i: {                                                           \
+    FOR_EACH_LANE(j, type) {                                          \
+      set_simd_register_by_lane<type>(r1, j, *bit_cast<type*>(addr)); \
+    }                                                                 \
+    break;                                                            \
   }
   switch (m3) {
     CASE(0, uint8_t);
@@ -3273,8 +3275,10 @@ EVALUATE(VML) {
     j = lane_size;                                                         \
   }                                                                        \
   for (; j < kSimd128Size; i += 2, j += lane_size * 2, k++) {              \
-    input_type src0 = get_simd_register_by_lane<input_type>(r2, i);        \
-    input_type src1 = get_simd_register_by_lane<input_type>(r3, i);        \
+    result_type src0 = static_cast<result_type>(                           \
+        get_simd_register_by_lane<input_type>(r2, i));                     \
+    result_type src1 = static_cast<result_type>(                           \
+        get_simd_register_by_lane<input_type>(r3, i));                     \
     set_simd_register_by_lane<result_type>(r1, k, src0 * src1);            \
   }
 #define VECTOR_MULTIPLY_EVEN_ODD(r1, r2, r3, is_odd, sign)                    \
@@ -3395,6 +3399,53 @@ EVALUATE(VSUMG) {
 }
 #undef CASE
 
+#define VECTOR_MERGE(type, is_low_side)                                      \
+  constexpr size_t index_limit = (kSimd128Size / sizeof(type)) / 2;          \
+  for (size_t i = 0, source_index = is_low_side ? i + index_limit : i;       \
+       i < index_limit; i++, source_index++) {                               \
+    set_simd_register_by_lane<type>(                                         \
+        r1, 2 * i, get_simd_register_by_lane<type>(r2, source_index));       \
+    set_simd_register_by_lane<type>(                                         \
+        r1, (2 * i) + 1, get_simd_register_by_lane<type>(r3, source_index)); \
+  }
+#define CASE(i, type, is_low_side)  \
+  case i: {                         \
+    VECTOR_MERGE(type, is_low_side) \
+  } break;
+EVALUATE(VMRL) {
+  DCHECK_OPCODE(VMRL);
+  DECODE_VRR_C_INSTRUCTION(r1, r2, r3, m6, m5, m4);
+  USE(m6);
+  USE(m5);
+  switch (m4) {
+    CASE(0, int8_t, true);
+    CASE(1, int16_t, true);
+    CASE(2, int32_t, true);
+    CASE(3, int64_t, true);
+    default:
+      UNREACHABLE();
+  }
+  return length;
+}
+
+EVALUATE(VMRH) {
+  DCHECK_OPCODE(VMRH);
+  DECODE_VRR_C_INSTRUCTION(r1, r2, r3, m6, m5, m4);
+  USE(m6);
+  USE(m5);
+  switch (m4) {
+    CASE(0, int8_t, false);
+    CASE(1, int16_t, false);
+    CASE(2, int32_t, false);
+    CASE(3, int64_t, false);
+    default:
+      UNREACHABLE();
+  }
+  return length;
+}
+#undef CASE
+#undef VECTOR_MERGE
+
 template <class S, class D>
 void VectorPack(Simulator* sim, int dst, int src1, int src2, bool saturate,
                 const D& max = 0, const D& min = 0) {
@@ -3901,8 +3952,7 @@ EVALUATE(VBPERM) {
   USE(m5);
   USE(m6);
   uint16_t result_bits = 0;
-  unsigned __int128 src_bits =
-      *(reinterpret_cast<__int128*>(get_simd_register(r2).int8));
+  unsigned __int128 src_bits = bit_cast<__int128>(get_simd_register(r2).int8);
   for (int i = 0; i < kSimd128Size; i++) {
     result_bits <<= 1;
     uint8_t selected_bit_index = get_simd_register_by_lane<uint8_t>(r3, i);
@@ -5443,7 +5493,7 @@ EVALUATE(LD) {
   int64_t b2_val = (b2 == 0) ? 0 : get_register(b2);
   int64_t x2_val = (x2 == 0) ? 0 : get_register(x2);
   intptr_t addr = b2_val + x2_val + d2_val;
-  int64_t dbl_val = *reinterpret_cast<int64_t*>(addr);
+  int64_t dbl_val = *bit_cast<int64_t*>(addr);
   set_fpr(r1, dbl_val);
   return length;
 }
@@ -5482,7 +5532,7 @@ EVALUATE(LE) {
   int64_t b2_val = (b2 == 0) ? 0 : get_register(b2);
   int64_t x2_val = (x2 == 0) ? 0 : get_register(x2);
   intptr_t addr = b2_val + x2_val + d2_val;
-  float float_val = *reinterpret_cast<float*>(addr);
+  float float_val = *bit_cast<float*>(addr);
   set_fpr(r1, float_val);
   return length;
 }
@@ -11157,7 +11207,7 @@ EVALUATE(LEY) {
   int64_t x2_val = (x2 == 0) ? 0 : get_register(x2);
   int64_t b2_val = (b2 == 0) ? 0 : get_register(b2);
   intptr_t addr = x2_val + b2_val + d2;
-  float float_val = *reinterpret_cast<float*>(addr);
+  float float_val = *bit_cast<float*>(addr);
   set_fpr(r1, float_val);
   return length;
 }
@@ -11169,7 +11219,7 @@ EVALUATE(LDY) {
   int64_t x2_val = (x2 == 0) ? 0 : get_register(x2);
   int64_t b2_val = (b2 == 0) ? 0 : get_register(b2);
   intptr_t addr = x2_val + b2_val + d2;
-  uint64_t dbl_val = *reinterpret_cast<uint64_t*>(addr);
+  uint64_t dbl_val = *bit_cast<uint64_t*>(addr);
   set_fpr(r1, dbl_val);
   return length;
 }
diff --git a/chromium/v8/src/execution/shared-mutex-guard-if-off-thread.h b/chromium/v8/src/execution/shared-mutex-guard-if-off-thread.h
index 972f6c0c89a..8dfcd09f396 100644
--- a/chromium/v8/src/execution/shared-mutex-guard-if-off-thread.h
+++ b/chromium/v8/src/execution/shared-mutex-guard-if-off-thread.h
@@ -10,7 +10,7 @@
 namespace v8 {
 namespace internal {
 
-template <typename LocalIsolate, base::MutexSharedType kIsShared>
+template <typename IsolateT, base::MutexSharedType kIsShared>
 class SharedMutexGuardIfOffThread;
 
 }  // namespace internal
diff --git a/chromium/v8/src/execution/stack-guard.cc b/chromium/v8/src/execution/stack-guard.cc
index dd32f58b98c..0bbdf1444ac 100644
--- a/chromium/v8/src/execution/stack-guard.cc
+++ b/chromium/v8/src/execution/stack-guard.cc
@@ -12,6 +12,7 @@
 #include "src/logging/counters.h"
 #include "src/objects/backing-store.h"
 #include "src/roots/roots-inl.h"
+#include "src/tracing/trace-event.h"
 #include "src/utils/memcopy.h"
 
 #if V8_ENABLE_WEBASSEMBLY
diff --git a/chromium/v8/src/extensions/cputracemark-extension.cc b/chromium/v8/src/extensions/cputracemark-extension.cc
index 5fde3608de8..029ad0f3cb7 100644
--- a/chromium/v8/src/extensions/cputracemark-extension.cc
+++ b/chromium/v8/src/extensions/cputracemark-extension.cc
@@ -16,9 +16,8 @@ CpuTraceMarkExtension::GetNativeFunctionTemplate(v8::Isolate* isolate,
 void CpuTraceMarkExtension::Mark(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() < 1 || !args[0]->IsUint32()) {
-    args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
-        args.GetIsolate(),
-        "First parameter to cputracemark() must be a unsigned int32."));
+    args.GetIsolate()->ThrowError(
+        "First parameter to cputracemark() must be a unsigned int32.");
     return;
   }
 
diff --git a/chromium/v8/src/extensions/externalize-string-extension.cc b/chromium/v8/src/extensions/externalize-string-extension.cc
index b153ebd075b..3e42b214de6 100644
--- a/chromium/v8/src/extensions/externalize-string-extension.cc
+++ b/chromium/v8/src/extensions/externalize-string-extension.cc
@@ -59,9 +59,8 @@ ExternalizeStringExtension::GetNativeFunctionTemplate(
 void ExternalizeStringExtension::Externalize(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() < 1 || !args[0]->IsString()) {
-    args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
-        args.GetIsolate(),
-        "First parameter to externalizeString() must be a string."));
+    args.GetIsolate()->ThrowError(
+        "First parameter to externalizeString() must be a string.");
     return;
   }
   bool force_two_byte = false;
@@ -69,17 +68,15 @@ void ExternalizeStringExtension::Externalize(
     if (args[1]->IsBoolean()) {
       force_two_byte = args[1]->BooleanValue(args.GetIsolate());
     } else {
-      args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
-          args.GetIsolate(),
-          "Second parameter to externalizeString() must be a boolean."));
+      args.GetIsolate()->ThrowError(
+          "Second parameter to externalizeString() must be a boolean.");
       return;
     }
   }
   bool result = false;
   Handle<String> string = Utils::OpenHandle(*args[0].As<v8::String>());
   if (!string->SupportsExternalization()) {
-    args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
-        args.GetIsolate(), "string does not support externalization."));
+    args.GetIsolate()->ThrowError("string does not support externalization.");
     return;
   }
   if (string->IsOneByteRepresentation() && !force_two_byte) {
@@ -98,8 +95,7 @@ void ExternalizeStringExtension::Externalize(
     if (!result) delete resource;
   }
   if (!result) {
-    args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
-        args.GetIsolate(), "externalizeString() failed."));
+    args.GetIsolate()->ThrowError("externalizeString() failed.");
     return;
   }
 }
@@ -108,9 +104,8 @@ void ExternalizeStringExtension::Externalize(
 void ExternalizeStringExtension::IsOneByte(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() != 1 || !args[0]->IsString()) {
-    args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
-        args.GetIsolate(),
-        "isOneByteString() requires a single string argument."));
+    args.GetIsolate()->ThrowError(
+        "isOneByteString() requires a single string argument.");
     return;
   }
   bool is_one_byte =
diff --git a/chromium/v8/src/extensions/vtunedomain-support-extension.cc b/chromium/v8/src/extensions/vtunedomain-support-extension.cc
index 793ffec7167..9a7715bb237 100644
--- a/chromium/v8/src/extensions/vtunedomain-support-extension.cc
+++ b/chromium/v8/src/extensions/vtunedomain-support-extension.cc
@@ -109,10 +109,9 @@ void VTuneDomainSupportExtension::Mark(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() != 3 || !args[0]->IsString() || !args[1]->IsString() ||
       !args[2]->IsString()) {
-    args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
-        args.GetIsolate(),
+    args.GetIsolate()->ThrowError(
         "Parameter number should be exactly three, first domain name"
-        "second task name, third start/end"));
+        "second task name, third start/end");
     return;
   }
 
@@ -130,7 +129,7 @@ void VTuneDomainSupportExtension::Mark(
 
   int r = 0;
   if ((r = libvtune::invoke(params.str().c_str())) != 0) {
-    args.GetIsolate()->ThrowException(
+    args.GetIsolate()->ThrowError(
         v8::String::NewFromUtf8(args.GetIsolate(), std::to_string(r).c_str())
             .ToLocalChecked());
   }
diff --git a/chromium/v8/src/flags/flag-definitions.h b/chromium/v8/src/flags/flag-definitions.h
index fa59c204613..e1f493ae7b1 100644
--- a/chromium/v8/src/flags/flag-definitions.h
+++ b/chromium/v8/src/flags/flag-definitions.h
@@ -151,6 +151,12 @@ struct MaybeBoolFlag {
 #define COMPRESS_POINTERS_BOOL false
 #endif
 
+#ifdef V8_MAP_PACKING
+#define V8_MAP_PACKING_BOOL true
+#else
+#define V8_MAP_PACKING_BOOL false
+#endif
+
 #ifdef V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE
 #define COMPRESS_POINTERS_IN_ISOLATE_CAGE_BOOL true
 #else
@@ -176,7 +182,7 @@ struct MaybeBoolFlag {
 #endif
 
 #if V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || \
-    V8_TARGET_ARCH_ARM
+    V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_RISCV64
 #define ENABLE_SPARKPLUG true
 #else
 // TODO(v8:11421): Enable Sparkplug for other architectures
@@ -259,8 +265,6 @@ DEFINE_BOOL(use_strict, false, "enforce strict mode")
 
 DEFINE_BOOL(harmony, false, "enable all completed harmony features")
 DEFINE_BOOL(harmony_shipping, true, "enable all shipped harmony features")
-// Enabling FinalizationRegistry#cleanupSome also enables weak refs
-DEFINE_IMPLICATION(harmony_weak_refs_with_cleanup_some, harmony_weak_refs)
 
 // Update bootstrapper.cc whenever adding a new feature flag.
 
@@ -269,12 +273,13 @@ DEFINE_IMPLICATION(harmony_weak_refs_with_cleanup_some, harmony_weak_refs)
   V(harmony_regexp_sequence, "RegExp Unicode sequence properties")             \
   V(harmony_weak_refs_with_cleanup_some,                                       \
     "harmony weak references with FinalizationRegistry.prototype.cleanupSome") \
-  V(harmony_import_assertions, "harmony import assertions")
+  V(harmony_import_assertions, "harmony import assertions")                    \
+  V(harmony_rab_gsab,                                                          \
+    "harmony ResizableArrayBuffer / GrowableSharedArrayBuffer")
 
 #ifdef V8_INTL_SUPPORT
-#define HARMONY_INPROGRESS(V)                             \
-  HARMONY_INPROGRESS_BASE(V)                              \
-  V(harmony_intl_best_fit_matcher, "Intl BestFitMatcher") \
+#define HARMONY_INPROGRESS(V) \
+  HARMONY_INPROGRESS_BASE(V)  \
   V(harmony_intl_displaynames_date_types, "Intl.DisplayNames date types")
 #else
 #define HARMONY_INPROGRESS(V) HARMONY_INPROGRESS_BASE(V)
@@ -282,14 +287,14 @@ DEFINE_IMPLICATION(harmony_weak_refs_with_cleanup_some, harmony_weak_refs)
 
 // Features that are complete (but still behind --harmony/es-staging flag).
 #define HARMONY_STAGED_BASE(V)                                              \
-  V(harmony_relative_indexing_methods, "harmony relative indexing methods") \
-  V(harmony_class_static_blocks, "harmony static initializer blocks")
+  V(harmony_class_static_blocks, "harmony static initializer blocks")       \
+  V(harmony_error_cause, "harmony error cause property")
 
 #ifdef V8_INTL_SUPPORT
-#define HARMONY_STAGED(V)               \
-  HARMONY_STAGED_BASE(V)                \
-  V(harmony_intl_dateformat_day_period, \
-    "Add dayPeriod option to DateTimeFormat")
+#define HARMONY_STAGED(V)                                 \
+  HARMONY_STAGED_BASE(V)                                  \
+  V(harmony_intl_best_fit_matcher, "Intl BestFitMatcher") \
+  V(harmony_intl_locale_info, "Intl locale info")
 #else
 #define HARMONY_STAGED(V) HARMONY_STAGED_BASE(V)
 #endif
@@ -298,13 +303,16 @@ DEFINE_IMPLICATION(harmony_weak_refs_with_cleanup_some, harmony_weak_refs)
 #define HARMONY_SHIPPING_BASE(V)                                  \
   V(harmony_sharedarraybuffer, "harmony sharedarraybuffer")       \
   V(harmony_atomics, "harmony atomics")                           \
-  V(harmony_weak_refs, "harmony weak references")                 \
   V(harmony_regexp_match_indices, "harmony regexp match indices") \
   V(harmony_private_brand_checks, "harmony private brand checks") \
-  V(harmony_top_level_await, "harmony top level await")
+  V(harmony_top_level_await, "harmony top level await")           \
+  V(harmony_relative_indexing_methods, "harmony relative indexing methods")
 
 #ifdef V8_INTL_SUPPORT
-#define HARMONY_SHIPPING(V) HARMONY_SHIPPING_BASE(V)
+#define HARMONY_SHIPPING(V)             \
+  HARMONY_SHIPPING_BASE(V)              \
+  V(harmony_intl_dateformat_day_period, \
+    "Add dayPeriod option to DateTimeFormat")
 #else
 #define HARMONY_SHIPPING(V) HARMONY_SHIPPING_BASE(V)
 #endif
@@ -334,6 +342,13 @@ HARMONY_SHIPPING(FLAG_SHIPPING_FEATURES)
 DEFINE_BOOL(builtin_subclassing, true,
             "subclassing support in built-in methods")
 
+// If the following flag is set to `true`, the SharedArrayBuffer constructor is
+// enabled per context depending on the callback set via
+// `SetSharedArrayBufferConstructorEnabledCallback`. If no callback is set, the
+// SharedArrayBuffer constructor is disabled.
+DEFINE_BOOL(enable_sharedarraybuffer_per_context, false,
+            "enable the SharedArrayBuffer constructor per context")
+
 #ifdef V8_INTL_SUPPORT
 DEFINE_BOOL(icu_timezone_data, true, "get information about timezones from ICU")
 #endif
@@ -362,6 +377,17 @@ DEFINE_BOOL(icu_timezone_data, true, "get information about timezones from ICU")
 #define V8_SHARED_RO_HEAP_BOOL false
 #endif
 
+DEFINE_BOOL(stress_snapshot, false,
+            "disables sharing of the read-only heap for testing")
+// Incremental marking is incompatible with the stress_snapshot mode;
+// specifically, serialization may clear bytecode arrays from shared function
+// infos which the MarkCompactCollector (running concurrently) may still need.
+// See also https://crbug.com/v8/10882.
+//
+// Note: This is not an issue in production because we don't clear SFI's
+// there (that only happens in mksnapshot and in --stress-snapshot mode).
+DEFINE_NEG_IMPLICATION(stress_snapshot, incremental_marking)
+
 DEFINE_BOOL(lite_mode, V8_LITE_BOOL,
             "enables trade-off of performance for memory savings")
 
@@ -379,6 +405,13 @@ DEFINE_IMPLICATION(lite_mode, optimize_for_size)
 DEFINE_NEG_IMPLICATION(enable_third_party_heap, inline_new)
 DEFINE_NEG_IMPLICATION(enable_third_party_heap, allocation_site_pretenuring)
 DEFINE_NEG_IMPLICATION(enable_third_party_heap, turbo_allocation_folding)
+DEFINE_NEG_IMPLICATION(enable_third_party_heap, concurrent_recompilation)
+DEFINE_NEG_IMPLICATION(enable_third_party_heap, concurrent_inlining)
+DEFINE_NEG_IMPLICATION(enable_third_party_heap,
+                       finalize_streaming_on_background)
+DEFINE_NEG_IMPLICATION(enable_third_party_heap, use_marking_progress_bar)
+DEFINE_NEG_IMPLICATION(enable_third_party_heap, move_object_start)
+DEFINE_NEG_IMPLICATION(enable_third_party_heap, concurrent_marking)
 
 DEFINE_BOOL_READONLY(enable_third_party_heap, V8_ENABLE_THIRD_PARTY_HEAP_BOOL,
                      "Use third-party heap")
@@ -407,19 +440,15 @@ DEFINE_BOOL_READONLY(enable_unconditional_write_barriers,
                      "always use full write barriers")
 
 #ifdef V8_ENABLE_SINGLE_GENERATION
-#define V8_GENERATION_BOOL true
+#define V8_SINGLE_GENERATION_BOOL true
 #else
-#define V8_GENERATION_BOOL false
+#define V8_SINGLE_GENERATION_BOOL false
 #endif
 
 DEFINE_BOOL_READONLY(
-    single_generation, V8_GENERATION_BOOL,
+    single_generation, V8_SINGLE_GENERATION_BOOL,
     "allocate all objects from young generation to old generation")
 
-// Prevent inline allocation into new space
-DEFINE_NEG_IMPLICATION(single_generation, inline_new)
-DEFINE_NEG_IMPLICATION(single_generation, turbo_allocation_folding)
-
 #ifdef V8_ENABLE_CONSERVATIVE_STACK_SCANNING
 #define V8_ENABLE_CONSERVATIVE_STACK_SCANNING_BOOL true
 #else
@@ -589,7 +618,6 @@ DEFINE_BOOL(trace_generalization, false, "trace map generalization")
 
 // Flags for TurboProp.
 DEFINE_BOOL(turboprop, false, "enable experimental turboprop mid-tier compiler")
-DEFINE_IMPLICATION(turboprop, turbo_direct_heap_access)
 DEFINE_BOOL(turboprop_mid_tier_reg_alloc, true,
             "enable mid-tier register allocator for turboprop")
 DEFINE_BOOL(
@@ -619,11 +647,10 @@ DEFINE_BOOL(always_sparkplug, false, "directly tier up to Sparkplug code")
 DEFINE_IMPLICATION(always_sparkplug, sparkplug)
 #endif
 DEFINE_STRING(sparkplug_filter, "*", "filter for Sparkplug baseline compiler")
+DEFINE_BOOL(sparkplug_needs_short_builtins, false,
+            "only enable Sparkplug baseline compiler when "
+            "--short-builtin-calls are also enabled")
 DEFINE_BOOL(trace_baseline, false, "trace baseline compilation")
-#if !defined(V8_OS_MACOSX) || !defined(V8_HOST_ARCH_ARM64)
-// Don't disable --write-protect-code-memory on Apple Silicon.
-DEFINE_WEAK_VALUE_IMPLICATION(sparkplug, write_protect_code_memory, false)
-#endif
 
 #undef FLAG
 #define FLAG FLAG_FULL
@@ -652,13 +679,16 @@ DEFINE_BOOL(concurrent_inlining, false,
             "run optimizing compiler's inlining phase on a separate thread")
 DEFINE_BOOL(stress_concurrent_inlining, false,
             "makes concurrent inlining more likely to trigger in tests")
-DEFINE_BOOL(turbo_direct_heap_access, false,
-            "access kNeverSerialized objects directly from the heap")
 DEFINE_IMPLICATION(stress_concurrent_inlining, concurrent_inlining)
 DEFINE_NEG_IMPLICATION(stress_concurrent_inlining, lazy_feedback_allocation)
 DEFINE_WEAK_VALUE_IMPLICATION(stress_concurrent_inlining, interrupt_budget,
                               15 * KB)
-DEFINE_IMPLICATION(concurrent_inlining, turbo_direct_heap_access)
+DEFINE_BOOL(
+    turbo_concurrent_get_property_access_info, false,
+    "concurrently call GetPropertyAccessInfo (only with --concurrent-inlining)")
+DEFINE_BOOL(turbo_concurrent_inlining_check_ispendingallocation, false,
+            "when --concurrent-inlining is enabled, check IsPendingAllocation "
+            "in Ref construction")
 DEFINE_INT(max_serializer_nesting, 25,
            "maximum levels for nesting child serializers")
 DEFINE_WEAK_IMPLICATION(future, concurrent_inlining)
@@ -811,28 +841,20 @@ DEFINE_INT(reuse_opt_code_count, 0,
            "don't discard optimized code for the specified number of deopts.")
 DEFINE_BOOL(turbo_dynamic_map_checks, true,
             "use dynamic map checks when generating code for property accesses "
-            "if all handlers in an IC are the same for turboprop and NCI")
+            "if all handlers in an IC are the same for turboprop")
 DEFINE_BOOL(turbo_compress_translation_arrays, false,
             "compress translation arrays (experimental)")
 DEFINE_BOOL(turbo_inline_js_wasm_calls, false, "inline JS->Wasm calls")
-
-// Native context independent (NCI) code.
-DEFINE_BOOL(turbo_nci, false,
-            "enable experimental native context independent code.")
-// TODO(v8:8888): Temporary until NCI caching is implemented or
-// feedback collection is made unconditional.
-DEFINE_IMPLICATION(turbo_nci, turbo_collect_feedback_in_generic_lowering)
-DEFINE_BOOL(print_nci_code, false, "print native context independent code.")
-DEFINE_BOOL(trace_turbo_nci, false, "trace native context independent code.")
 DEFINE_BOOL(turbo_collect_feedback_in_generic_lowering, true,
             "enable experimental feedback collection in generic lowering.")
-// TODO(jgruber,v8:8888): Remove this flag once we've settled on an ageing
-// strategy.
 DEFINE_BOOL(isolate_script_cache_ageing, true,
             "enable ageing of the isolate script cache.")
 
-DEFINE_INT(script_run_delay, 0, "sleep [ms] on every Script::Run")
-DEFINE_INT(script_run_delay_once, 0, "sleep [ms] on the first Script::Run")
+DEFINE_FLOAT(script_delay, 0, "busy wait [ms] on every Script::Run")
+DEFINE_FLOAT(script_delay_once, 0, "busy wait [ms] on the first Script::Run")
+DEFINE_FLOAT(script_delay_fraction, 0.0,
+             "busy wait after each Script::Run by the given fraction of the "
+             "run's duration")
 
 // Favor memory over execution speed.
 DEFINE_BOOL(optimize_for_size, false,
@@ -862,7 +884,11 @@ DEFINE_VALUE_IMPLICATION(single_threaded, wasm_num_compilation_tasks, 0)
 DEFINE_DEBUG_BOOL(trace_wasm_native_heap, false,
                   "trace wasm native heap events")
 DEFINE_BOOL(wasm_write_protect_code_memory, false,
-            "write protect code memory on the wasm native heap")
+            "write protect code memory on the wasm native heap with mprotect")
+DEFINE_BOOL(wasm_memory_protection_keys, false,
+            "protect wasm code memory with PKU if available, no protection "
+            "without support; fallback to mprotect by adding "
+            "--wasm-write-protect-code-memory")
 DEFINE_DEBUG_BOOL(trace_wasm_serialization, false,
                   "trace serialization/deserialization")
 DEFINE_BOOL(wasm_async_compilation, true,
@@ -1172,7 +1198,6 @@ DEFINE_GENERIC_IMPLICATION(
     TracingFlags::gc_stats.store(
         v8::tracing::TracingCategoryObserver::ENABLED_BY_NATIVE))
 DEFINE_NEG_IMPLICATION(trace_gc_object_stats, incremental_marking)
-DEFINE_NEG_IMPLICATION(track_retaining_path, incremental_marking)
 DEFINE_NEG_IMPLICATION(track_retaining_path, parallel_marking)
 DEFINE_NEG_IMPLICATION(track_retaining_path, concurrent_marking)
 DEFINE_BOOL(track_detached_contexts, true,
@@ -1261,11 +1286,19 @@ DEFINE_BOOL_READONLY(
     "object space")
 
 // assembler-ia32.cc / assembler-arm.cc / assembler-arm64.cc / assembler-x64.cc
+#ifdef V8_ENABLE_DEBUG_CODE
 DEFINE_BOOL(debug_code, DEBUG_BOOL,
             "generate extra code (assertions) for debugging")
+#else
+DEFINE_BOOL_READONLY(debug_code, false, "")
+#endif
+#ifdef V8_CODE_COMMENTS
 DEFINE_BOOL(code_comments, false,
             "emit comments in code disassembly; for more readable source "
             "positions you should add --no-concurrent_recompilation")
+#else
+DEFINE_BOOL_READONLY(code_comments, false, "")
+#endif
 DEFINE_BOOL(enable_sse3, true, "enable use of SSE3 instructions if available")
 DEFINE_BOOL(enable_ssse3, true, "enable use of SSSE3 instructions if available")
 DEFINE_BOOL(enable_sse4_1, true,
@@ -1293,10 +1326,18 @@ DEFINE_BOOL(partial_constant_pool, true,
 DEFINE_STRING(sim_arm64_optional_features, "none",
               "enable optional features on the simulator for testing: none or "
               "all")
-DEFINE_BOOL(debug_riscv, false, "enable debug prints")
-// TODO(RISCV): https://github.com/v8-riscv/v8/issues/330
-DEFINE_BOOL(disable_riscv_constant_pool, true,
-            "disable constant pool (RISCV only)")
+
+#if defined(V8_TARGET_ARCH_RISCV64)
+DEFINE_BOOL(riscv_trap_to_simulator_debugger, false,
+            "enable simulator trap to debugger")
+DEFINE_BOOL(riscv_debug, false, "enable debug prints")
+
+DEFINE_BOOL(riscv_constant_pool, true,
+            "enable constant pool (RISCV only)")
+
+DEFINE_BOOL(riscv_c_extension, false,
+            "enable compressed extension isa variant (RISCV only)")
+#endif
 
 // Controlling source positions for Torque/CSA code.
 DEFINE_BOOL(enable_source_at_csa_bind, false,
@@ -1472,6 +1513,8 @@ DEFINE_BOOL(native_code_counters, DEBUG_BOOL,
 
 DEFINE_BOOL(super_ic, true, "use an IC for super property loads")
 
+DEFINE_BOOL(enable_mega_dom_ic, false, "use MegaDOM IC state for API objects")
+
 // objects.cc
 DEFINE_BOOL(thin_strings, true, "Enable ThinString support")
 DEFINE_BOOL(trace_prototype_users, false,
@@ -1554,7 +1597,7 @@ DEFINE_BOOL(
     "includes arguments for each function call in the error stack frames array")
 DEFINE_BOOL(adjust_os_scheduling_parameters, true,
             "adjust OS specific scheduling params for the isolate")
-DEFINE_BOOL(experimental_flush_embedded_blob_icache, false,
+DEFINE_BOOL(experimental_flush_embedded_blob_icache, true,
             "Used in an experiment to evaluate icache flushing on certain CPUs")
 
 // Flags for short builtin calls feature
diff --git a/chromium/v8/src/flags/flags.cc b/chromium/v8/src/flags/flags.cc
index 9825b5b1eaf..2cd9174148a 100644
--- a/chromium/v8/src/flags/flags.cc
+++ b/chromium/v8/src/flags/flags.cc
@@ -16,6 +16,8 @@
 #include "src/base/platform/platform.h"
 #include "src/codegen/cpu-features.h"
 #include "src/logging/counters.h"
+#include "src/logging/tracing-flags.h"
+#include "src/tracing/tracing-category-observer.h"
 #include "src/utils/allocation.h"
 #include "src/utils/memcopy.h"
 #include "src/utils/ostreams.h"
diff --git a/chromium/v8/src/handles/global-handles.cc b/chromium/v8/src/handles/global-handles.cc
index 6bc290eac71..9e4aad27fb3 100644
--- a/chromium/v8/src/handles/global-handles.cc
+++ b/chromium/v8/src/handles/global-handles.cc
@@ -8,8 +8,10 @@
 #include <cstdint>
 #include <map>
 
+#include "include/v8.h"
 #include "src/api/api-inl.h"
 #include "src/base/compiler-specific.h"
+#include "src/base/sanitizer/asan.h"
 #include "src/execution/vm-state-inl.h"
 #include "src/heap/embedder-tracing.h"
 #include "src/heap/heap-write-barrier-inl.h"
@@ -18,7 +20,6 @@
 #include "src/objects/objects-inl.h"
 #include "src/objects/slots.h"
 #include "src/objects/visitors.h"
-#include "src/sanitizer/asan.h"
 #include "src/tasks/cancelable-task.h"
 #include "src/tasks/task-utils.h"
 #include "src/utils/utils.h"
@@ -382,11 +383,11 @@ namespace {
 
 void ExtractInternalFields(JSObject jsobject, void** embedder_fields, int len) {
   int field_count = jsobject.GetEmbedderFieldCount();
-  PtrComprCageBase cage_base = GetPtrComprCageBase(jsobject);
+  Isolate* isolate = GetIsolateForHeapSandbox(jsobject);
   for (int i = 0; i < len; ++i) {
     if (field_count == i) break;
     void* pointer;
-    if (EmbedderDataSlot(jsobject, i).ToAlignedPointer(cage_base, &pointer)) {
+    if (EmbedderDataSlot(jsobject, i).ToAlignedPointer(isolate, &pointer)) {
       embedder_fields[i] = pointer;
     }
   }
@@ -1252,18 +1253,21 @@ void GlobalHandles::IdentifyWeakUnmodifiedObjects(
     WeakSlotCallback is_unmodified) {
   if (!FLAG_reclaim_unmodified_wrappers) return;
 
-  LocalEmbedderHeapTracer* const tracer =
-      isolate()->heap()->local_embedder_heap_tracer();
+  // Treat all objects as roots during incremental marking to avoid corrupting
+  // marking worklists.
+  if (isolate()->heap()->incremental_marking()->IsMarking()) return;
+
+  auto* const handler = isolate()->heap()->GetEmbedderRootsHandler();
   for (TracedNode* node : traced_young_nodes_) {
     if (node->IsInUse()) {
       DCHECK(node->is_root());
       if (is_unmodified(node->location())) {
         v8::Value* value = ToApi<v8::Value>(node->handle());
         if (node->has_destructor()) {
-          node->set_root(tracer->IsRootForNonTracingGC(
+          node->set_root(handler->IsRoot(
               *reinterpret_cast<v8::TracedGlobal<v8::Value>*>(&value)));
         } else {
-          node->set_root(tracer->IsRootForNonTracingGC(
+          node->set_root(handler->IsRoot(
               *reinterpret_cast<v8::TracedReference<v8::Value>*>(&value)));
         }
       }
@@ -1337,8 +1341,7 @@ void GlobalHandles::IterateYoungWeakObjectsForPhantomHandles(
 
   if (!FLAG_reclaim_unmodified_wrappers) return;
 
-  LocalEmbedderHeapTracer* const tracer =
-      isolate()->heap()->local_embedder_heap_tracer();
+  auto* const handler = isolate()->heap()->GetEmbedderRootsHandler();
   for (TracedNode* node : traced_young_nodes_) {
     if (!node->IsInUse()) continue;
 
@@ -1353,7 +1356,7 @@ void GlobalHandles::IterateYoungWeakObjectsForPhantomHandles(
           node->ResetPhantomHandle(HandleHolder::kLive);
         } else {
           v8::Value* value = ToApi<v8::Value>(node->handle());
-          tracer->ResetHandleInNonTracingGC(
+          handler->ResetRoot(
               *reinterpret_cast<v8::TracedReference<v8::Value>*>(&value));
           DCHECK(!node->IsInUse());
         }
diff --git a/chromium/v8/src/handles/handles-inl.h b/chromium/v8/src/handles/handles-inl.h
index 360da25cf63..4c1817e80d2 100644
--- a/chromium/v8/src/handles/handles-inl.h
+++ b/chromium/v8/src/handles/handles-inl.h
@@ -5,12 +5,12 @@
 #ifndef V8_HANDLES_HANDLES_INL_H_
 #define V8_HANDLES_HANDLES_INL_H_
 
+#include "src/base/sanitizer/msan.h"
 #include "src/execution/isolate.h"
 #include "src/execution/local-isolate.h"
 #include "src/handles/handles.h"
 #include "src/handles/local-handles-inl.h"
 #include "src/objects/objects.h"
-#include "src/sanitizer/msan.h"
 
 namespace v8 {
 namespace internal {
diff --git a/chromium/v8/src/handles/local-handles-inl.h b/chromium/v8/src/handles/local-handles-inl.h
index c9f1588410b..b8621559492 100644
--- a/chromium/v8/src/handles/local-handles-inl.h
+++ b/chromium/v8/src/handles/local-handles-inl.h
@@ -5,10 +5,10 @@
 #ifndef V8_HANDLES_LOCAL_HANDLES_INL_H_
 #define V8_HANDLES_LOCAL_HANDLES_INL_H_
 
+#include "src/base/sanitizer/msan.h"
 #include "src/execution/isolate.h"
 #include "src/execution/local-isolate.h"
 #include "src/handles/local-handles.h"
-#include "src/sanitizer/msan.h"
 
 namespace v8 {
 namespace internal {
diff --git a/chromium/v8/src/heap/array-buffer-sweeper.cc b/chromium/v8/src/heap/array-buffer-sweeper.cc
index 8af2a60e9c1..108a3497776 100644
--- a/chromium/v8/src/heap/array-buffer-sweeper.cc
+++ b/chromium/v8/src/heap/array-buffer-sweeper.cc
@@ -101,30 +101,25 @@ void ArrayBufferSweeper::EnsureFinished() {
       UNREACHABLE();
   }
 
-  DecrementExternalMemoryCounters();
+  UpdateCountersForConcurrentlySweptExtensions();
   sweeping_in_progress_ = false;
 }
 
-void ArrayBufferSweeper::AdjustCountersAndMergeIfPossible() {
+void ArrayBufferSweeper::MergeBackExtensionsWhenSwept() {
   if (sweeping_in_progress_) {
     DCHECK(job_.has_value());
     if (job_->state_ == SweepingState::kDone) {
       Merge();
       sweeping_in_progress_ = false;
     } else {
-      DecrementExternalMemoryCounters();
+      UpdateCountersForConcurrentlySweptExtensions();
     }
   }
 }
 
-void ArrayBufferSweeper::DecrementExternalMemoryCounters() {
+void ArrayBufferSweeper::UpdateCountersForConcurrentlySweptExtensions() {
   size_t freed_bytes = freed_bytes_.exchange(0, std::memory_order_relaxed);
-
-  if (freed_bytes > 0) {
-    heap_->DecrementExternalBackingStoreBytes(
-        ExternalBackingStoreType::kArrayBuffer, freed_bytes);
-    heap_->update_external_memory(-static_cast<int64_t>(freed_bytes));
-  }
+  DecrementExternalMemoryCounters(freed_bytes);
 }
 
 void ArrayBufferSweeper::RequestSweepYoung() {
@@ -166,7 +161,7 @@ void ArrayBufferSweeper::RequestSweep(SweepingScope scope) {
     Prepare(scope);
     job_->Sweep();
     Merge();
-    DecrementExternalMemoryCounters();
+    UpdateCountersForConcurrentlySweptExtensions();
   }
 }
 
@@ -228,18 +223,52 @@ void ArrayBufferSweeper::Append(JSArrayBuffer object,
     old_bytes_ += bytes;
   }
 
-  AdjustCountersAndMergeIfPossible();
-  DecrementExternalMemoryCounters();
+  MergeBackExtensionsWhenSwept();
   IncrementExternalMemoryCounters(bytes);
 }
 
+void ArrayBufferSweeper::Detach(JSArrayBuffer object,
+                                ArrayBufferExtension* extension) {
+  size_t bytes = extension->ClearAccountingLength();
+
+  // We cannot free the extension eagerly here, since extensions are tracked in
+  // a singly linked list. The next GC will remove it automatically.
+
+  if (!sweeping_in_progress_) {
+    // If concurrent sweeping isn't running at the moment, we can also adjust
+    // young_bytes_ or old_bytes_ right away.
+    if (Heap::InYoungGeneration(object)) {
+      DCHECK_GE(young_bytes_, bytes);
+      young_bytes_ -= bytes;
+      young_.bytes_ -= bytes;
+    } else {
+      DCHECK_GE(old_bytes_, bytes);
+      old_bytes_ -= bytes;
+      old_.bytes_ -= bytes;
+    }
+  }
+
+  MergeBackExtensionsWhenSwept();
+  DecrementExternalMemoryCounters(bytes);
+}
+
 void ArrayBufferSweeper::IncrementExternalMemoryCounters(size_t bytes) {
+  if (bytes == 0) return;
   heap_->IncrementExternalBackingStoreBytes(
       ExternalBackingStoreType::kArrayBuffer, bytes);
   reinterpret_cast<v8::Isolate*>(heap_->isolate())
       ->AdjustAmountOfExternalAllocatedMemory(static_cast<int64_t>(bytes));
 }
 
+void ArrayBufferSweeper::DecrementExternalMemoryCounters(size_t bytes) {
+  if (bytes == 0) return;
+  heap_->DecrementExternalBackingStoreBytes(
+      ExternalBackingStoreType::kArrayBuffer, bytes);
+  // Unlike IncrementExternalMemoryCounters we don't use
+  // AdjustAmountOfExternalAllocatedMemory such that we never start a GC here.
+  heap_->update_external_memory(-static_cast<int64_t>(bytes));
+}
+
 void ArrayBufferSweeper::IncrementFreedBytes(size_t bytes) {
   if (bytes == 0) return;
   freed_bytes_.fetch_add(bytes, std::memory_order_relaxed);
diff --git a/chromium/v8/src/heap/array-buffer-sweeper.h b/chromium/v8/src/heap/array-buffer-sweeper.h
index 0c15428b754..6dd7ed97f6c 100644
--- a/chromium/v8/src/heap/array-buffer-sweeper.h
+++ b/chromium/v8/src/heap/array-buffer-sweeper.h
@@ -59,8 +59,12 @@ class ArrayBufferSweeper {
   void RequestSweepYoung();
   void RequestSweepFull();
 
+  // Track the given ArrayBufferExtension for the given JSArrayBuffer.
   void Append(JSArrayBuffer object, ArrayBufferExtension* extension);
 
+  // Detaches an ArrayBufferExtension from a JSArrayBuffer.
+  void Detach(JSArrayBuffer object, ArrayBufferExtension* extension);
+
   ArrayBufferList young() { return young_; }
   ArrayBufferList old() { return old_; }
 
@@ -98,10 +102,11 @@ class ArrayBufferSweeper {
   base::Optional<SweepingJob> job_;
 
   void Merge();
-  void AdjustCountersAndMergeIfPossible();
+  void MergeBackExtensionsWhenSwept();
 
-  void DecrementExternalMemoryCounters();
+  void UpdateCountersForConcurrentlySweptExtensions();
   void IncrementExternalMemoryCounters(size_t bytes);
+  void DecrementExternalMemoryCounters(size_t bytes);
   void IncrementFreedBytes(size_t bytes);
 
   void RequestSweep(SweepingScope sweeping_task);
diff --git a/chromium/v8/src/heap/base/asm/riscv64/push_registers_asm.cc b/chromium/v8/src/heap/base/asm/riscv64/push_registers_asm.cc
index 1de4055a283..2d90aab1829 100644
--- a/chromium/v8/src/heap/base/asm/riscv64/push_registers_asm.cc
+++ b/chromium/v8/src/heap/base/asm/riscv64/push_registers_asm.cc
@@ -5,21 +5,26 @@
 // Push all callee-saved registers to get them on the stack for conservative
 // stack scanning.
 //
-// See asm/x64/push_registers_clang.cc for why the function is not generated
+// See asm/x64/push_registers_asm.cc for why the function is not generated
 // using clang.
 //
-// Do not depend on V8_TARGET_OS_* defines as some embedders may override the
-// GN toolchain (e.g. ChromeOS) and not provide them.
+// Calling convention source:
+// https://riscv.org/wp-content/uploads/2015/01/riscv-calling.pdf Table 18.2
 asm(".global PushAllRegistersAndIterateStack             \n"
     ".type PushAllRegistersAndIterateStack, %function    \n"
     ".hidden PushAllRegistersAndIterateStack             \n"
     "PushAllRegistersAndIterateStack:                    \n"
     // Push all callee-saved registers and save return address.
-    "  addi sp, sp, -96                                  \n"
-    "  sd ra, 88(sp)                                     \n"
-    "  sd s8, 80(sp)                                     \n"
-    "  sd sp, 72(sp)                                     \n"
-    "  sd gp, 64(sp)                                     \n"
+    "  addi sp, sp, -112                                 \n"
+    // Save return address.
+    "  sd ra, 104(sp)                                    \n"
+    // sp is callee-saved.
+    "  sd sp, 96(sp)                                     \n"
+    // s0-s11 are callee-saved.
+    "  sd s11, 88(sp)                                    \n"
+    "  sd s10, 80(sp)                                    \n"
+    "  sd s9, 72(sp)                                     \n"
+    "  sd s8, 64(sp)                                     \n"
     "  sd s7, 56(sp)                                     \n"
     "  sd s6, 48(sp)                                     \n"
     "  sd s5, 40(sp)                                     \n"
@@ -28,18 +33,19 @@ asm(".global PushAllRegistersAndIterateStack             \n"
     "  sd s2, 16(sp)                                     \n"
     "  sd s1,  8(sp)                                     \n"
     "  sd s0,  0(sp)                                     \n"
-    // Maintain frame pointer.
-    "  mv s8, sp                                         \n"
+    // Maintain frame pointer(fp is s0).
+    "  mv s0, sp                                         \n"
     // Pass 1st parameter (a0) unchanged (Stack*).
     // Pass 2nd parameter (a1) unchanged (StackVisitor*).
-    // Save 3rd parameter (a2; IterateStackCallback).
+    // Save 3rd parameter (a2; IterateStackCallback) to a3.
     "  mv a3, a2                                         \n"
+    // Pass 3rd parameter as sp (stack pointer).
     "  mv a2, sp                                         \n"
     // Call the callback.
     "  jalr a3                                           \n"
     // Load return address.
-    "  ld ra, 88(sp)                                     \n"
+    "  ld ra, 104(sp)                                    \n"
     // Restore frame pointer.
-    "  ld s8, 80(sp)                                     \n"
-    "  addi sp, sp, 96                                   \n"
+    "  ld s0, 0(sp)                                      \n"
+    "  addi sp, sp, 112                                  \n"
     "  jr ra                                             \n");
diff --git a/chromium/v8/src/heap/base/asm/x64/push_registers_asm.cc b/chromium/v8/src/heap/base/asm/x64/push_registers_asm.cc
index 68f7918c93c..9780b877b8c 100644
--- a/chromium/v8/src/heap/base/asm/x64/push_registers_asm.cc
+++ b/chromium/v8/src/heap/base/asm/x64/push_registers_asm.cc
@@ -19,7 +19,7 @@
 #ifdef _WIN64
 
 // We maintain 16-byte alignment at calls. There is an 8-byte return address
-// on the stack and we push 72 bytes which maintains 16-byte stack alignment
+// on the stack and we push 232 bytes which maintains 16-byte stack alignment
 // at the call.
 // Source: https://docs.microsoft.com/en-us/cpp/build/x64-calling-convention
 asm(".globl PushAllRegistersAndIterateStack             \n"
@@ -36,6 +36,18 @@ asm(".globl PushAllRegistersAndIterateStack             \n"
     "  push %r13                                        \n"
     "  push %r14                                        \n"
     "  push %r15                                        \n"
+    "  sub $160, %rsp                                   \n"
+    // Use aligned instrs as we are certain that the stack is properly aligned.
+    "  movdqa %xmm6, 144(%rsp)                          \n"
+    "  movdqa %xmm7, 128(%rsp)                          \n"
+    "  movdqa %xmm8, 112(%rsp)                          \n"
+    "  movdqa %xmm9, 96(%rsp)                           \n"
+    "  movdqa %xmm10, 80(%rsp)                          \n"
+    "  movdqa %xmm11, 64(%rsp)                          \n"
+    "  movdqa %xmm12, 48(%rsp)                          \n"
+    "  movdqa %xmm13, 32(%rsp)                          \n"
+    "  movdqa %xmm14, 16(%rsp)                          \n"
+    "  movdqa %xmm15, (%rsp)                            \n"
     // Pass 1st parameter (rcx) unchanged (Stack*).
     // Pass 2nd parameter (rdx) unchanged (StackVisitor*).
     // Save 3rd parameter (r8; IterateStackCallback)
@@ -45,7 +57,7 @@ asm(".globl PushAllRegistersAndIterateStack             \n"
     // Call the callback.
     "  call *%r9                                        \n"
     // Pop the callee-saved registers.
-    "  add $64, %rsp                                    \n"
+    "  add $224, %rsp                                   \n"
     // Restore rbp as it was used as frame pointer.
     "  pop %rbp                                         \n"
     "  ret                                              \n");
diff --git a/chromium/v8/src/heap/base/asm/x64/push_registers_masm.S b/chromium/v8/src/heap/base/asm/x64/push_registers_masm.S
index 627843830fa..a32e193c2f1 100644
--- a/chromium/v8/src/heap/base/asm/x64/push_registers_masm.S
+++ b/chromium/v8/src/heap/base/asm/x64/push_registers_masm.S
@@ -13,8 +13,8 @@ PushAllRegistersAndIterateStack:
     ;; stack scanning.
     ;;
     ;; We maintain 16-byte alignment at calls. There is an 8-byte return address
-    ;; on the stack and we push 72 bytes which maintains 16-byte stack alignment
-    ;; at the call.
+    ;; on the stack and we push 232 bytes which maintains 16-byte stack
+    ;; alignment at the call.
     ;; Source: https://docs.microsoft.com/en-us/cpp/build/x64-calling-convention
     ;;
     ;; rbp is callee-saved. Maintain proper frame pointer for debugging.
@@ -28,6 +28,18 @@ PushAllRegistersAndIterateStack:
     push r13
     push r14
     push r15
+    sub rsp, 160
+    ;; Use aligned instrs as we are certain that the stack is properly aligned.
+    movdqa  xmmword ptr [rsp + 144], xmm6
+    movdqa  xmmword ptr [rsp + 128], xmm7
+    movdqa  xmmword ptr [rsp + 112], xmm8
+    movdqa  xmmword ptr [rsp + 96], xmm9
+    movdqa  xmmword ptr [rsp + 80], xmm10
+    movdqa  xmmword ptr [rsp + 64], xmm11
+    movdqa  xmmword ptr [rsp + 48], xmm12
+    movdqa  xmmword ptr [rsp + 32], xmm13
+    movdqa  xmmword ptr [rsp + 16], xmm14
+    movdqa  xmmword ptr [rsp], xmm15
     ;; Pass 1st parameter (rcx) unchanged (Stack*).
     ;; Pass 2nd parameter (rdx) unchanged (StackVisitor*).
     ;; Save 3rd parameter (r8; IterateStackCallback)
@@ -37,7 +49,7 @@ PushAllRegistersAndIterateStack:
     ;; Call the callback.
     call r9
     ;; Pop the callee-saved registers.
-    add rsp, 64
+    add rsp, 224
     ;; Restore rbp as it was used as frame pointer.
     pop rbp
     ret
diff --git a/chromium/v8/src/heap/base/stack.cc b/chromium/v8/src/heap/base/stack.cc
index 939487ca77d..f6d522f1931 100644
--- a/chromium/v8/src/heap/base/stack.cc
+++ b/chromium/v8/src/heap/base/stack.cc
@@ -6,9 +6,11 @@
 
 #include <limits>
 
+#include "src/base/macros.h"
 #include "src/base/platform/platform.h"
+#include "src/base/sanitizer/asan.h"
+#include "src/base/sanitizer/msan.h"
 #include "src/heap/cppgc/globals.h"
-#include "src/heap/cppgc/sanitizers.h"
 
 namespace heap {
 namespace base {
@@ -41,7 +43,7 @@ namespace {
 
 // No ASAN support as accessing fake frames otherwise results in
 // "stack-use-after-scope" warnings.
-NO_SANITIZE_ADDRESS
+DISABLE_ASAN
 void IterateAsanFakeFrameIfNecessary(StackVisitor* visitor,
                                      void* asan_fake_stack,
                                      const void* stack_start,
@@ -77,7 +79,7 @@ void IterateSafeStackIfNecessary(StackVisitor* visitor) {
 #if defined(__has_feature)
 #if __has_feature(safe_stack)
   // Source:
-  // https://github.com/llvm/llvm-project/blob/master/compiler-rt/lib/safestack/safestack.cpp
+  // https://github.com/llvm/llvm-project/blob/main/compiler-rt/lib/safestack/safestack.cpp
   constexpr size_t kSafeStackAlignmentBytes = 16;
   void* stack_end = __builtin___get_unsafe_stack_ptr();
   void* stack_start = __builtin___get_unsafe_stack_top();
@@ -101,7 +103,7 @@ void IterateSafeStackIfNecessary(StackVisitor* visitor) {
 // any data that needs to be scanned.
 V8_NOINLINE
 // No ASAN support as method accesses redzones while walking the stack.
-NO_SANITIZE_ADDRESS
+DISABLE_ASAN
 void IteratePointersImpl(const Stack* stack, StackVisitor* visitor,
                          intptr_t* stack_end) {
 #ifdef V8_USE_ADDRESS_SANITIZER
@@ -116,7 +118,7 @@ void IteratePointersImpl(const Stack* stack, StackVisitor* visitor,
     // MSAN: Instead of unpoisoning the whole stack, the slot's value is copied
     // into a local which is unpoisoned.
     void* address = *current;
-    MSAN_UNPOISON(&address, sizeof(address));
+    MSAN_MEMORY_IS_INITIALIZED(&address, sizeof(address));
     if (address == nullptr) continue;
     visitor->VisitPointer(address);
 #ifdef V8_USE_ADDRESS_SANITIZER
@@ -135,5 +137,10 @@ void Stack::IteratePointers(StackVisitor* visitor) const {
   IterateSafeStackIfNecessary(visitor);
 }
 
+void Stack::IteratePointersUnsafe(StackVisitor* visitor,
+                                  uintptr_t stack_end) const {
+  IteratePointersImpl(this, visitor, reinterpret_cast<intptr_t*>(stack_end));
+}
+
 }  // namespace base
 }  // namespace heap
diff --git a/chromium/v8/src/heap/base/stack.h b/chromium/v8/src/heap/base/stack.h
index a46e6e660ed..d7267deee7e 100644
--- a/chromium/v8/src/heap/base/stack.h
+++ b/chromium/v8/src/heap/base/stack.h
@@ -26,10 +26,20 @@ class V8_EXPORT_PRIVATE Stack final {
   // Returns true if |slot| is part of the stack and false otherwise.
   bool IsOnStack(void* slot) const;
 
-  // Word-aligned iteration of the stack. Slot values are passed on to
-  // |visitor|.
+  // Word-aligned iteration of the stack. Callee-saved registers are pushed to
+  // the stack before iterating pointers. Slot values are passed on to
+  // `visitor`.
   void IteratePointers(StackVisitor* visitor) const;
 
+  // Word-aligned iteration of the stack, starting at `stack_end`. Slot values
+  // are passed on to `visitor`. This is intended to be used with verifiers that
+  // only visit a subset of the stack of IteratePointers().
+  //
+  // **Ignores:**
+  // - Callee-saved registers.
+  // - SafeStack.
+  void IteratePointersUnsafe(StackVisitor* visitor, uintptr_t stack_end) const;
+
   // Returns the start of the stack.
   const void* stack_start() const { return stack_start_; }
 
diff --git a/chromium/v8/src/heap/basic-memory-chunk.h b/chromium/v8/src/heap/basic-memory-chunk.h
index 1b2d7cb5dad..993291dc0e0 100644
--- a/chromium/v8/src/heap/basic-memory-chunk.h
+++ b/chromium/v8/src/heap/basic-memory-chunk.h
@@ -106,6 +106,9 @@ class BasicMemoryChunk {
     // because there exists a potential pointer to somewhere in the chunk which
     // can't be updated.
     PINNED = 1u << 22,
+
+    // This page belongs to a shared heap.
+    IN_SHARED_HEAP = 1u << 23,
   };
 
   static const intptr_t kAlignment =
@@ -255,6 +258,8 @@ class BasicMemoryChunk {
   bool InOldSpace() const;
   V8_EXPORT_PRIVATE bool InLargeObjectSpace() const;
 
+  bool InSharedHeap() const { return IsFlagSet(IN_SHARED_HEAP); }
+
   bool IsWritable() const {
     // If this is a read-only space chunk but heap_ is non-null, it has not yet
     // been sealed and can be written to.
@@ -294,11 +299,13 @@ class BasicMemoryChunk {
 
   // Only works if the pointer is in the first kPageSize of the MemoryChunk.
   static BasicMemoryChunk* FromAddress(Address a) {
+    DCHECK(!V8_ENABLE_THIRD_PARTY_HEAP_BOOL);
     return reinterpret_cast<BasicMemoryChunk*>(BaseAddress(a));
   }
 
   // Only works if the object is in the first kPageSize of the MemoryChunk.
   static BasicMemoryChunk* FromHeapObject(HeapObject o) {
+    DCHECK(!V8_ENABLE_THIRD_PARTY_HEAP_BOOL);
     return reinterpret_cast<BasicMemoryChunk*>(BaseAddress(o.ptr()));
   }
 
diff --git a/chromium/v8/src/heap/code-range.cc b/chromium/v8/src/heap/code-range.cc
new file mode 100644
index 00000000000..738c12710c9
--- /dev/null
+++ b/chromium/v8/src/heap/code-range.cc
@@ -0,0 +1,172 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/heap/code-range.h"
+
+#include "src/base/lazy-instance.h"
+#include "src/common/globals.h"
+#include "src/flags/flags.h"
+#include "src/heap/heap-inl.h"
+
+namespace v8 {
+namespace internal {
+
+namespace {
+
+DEFINE_LAZY_LEAKY_OBJECT_GETTER(std::shared_ptr<CodeRange>,
+                                GetProcessWideCodeRangeCage)
+
+DEFINE_LAZY_LEAKY_OBJECT_GETTER(CodeRangeAddressHint, GetCodeRangeAddressHint)
+
+void FunctionInStaticBinaryForAddressHint() {}
+}  // anonymous namespace
+
+Address CodeRangeAddressHint::GetAddressHint(size_t code_range_size) {
+  base::MutexGuard guard(&mutex_);
+  auto it = recently_freed_.find(code_range_size);
+  if (it == recently_freed_.end() || it->second.empty()) {
+    return FUNCTION_ADDR(&FunctionInStaticBinaryForAddressHint);
+  }
+  Address result = it->second.back();
+  it->second.pop_back();
+  return result;
+}
+
+void CodeRangeAddressHint::NotifyFreedCodeRange(Address code_range_start,
+                                                size_t code_range_size) {
+  base::MutexGuard guard(&mutex_);
+  recently_freed_[code_range_size].push_back(code_range_start);
+}
+
+CodeRange::~CodeRange() { Free(); }
+
+bool CodeRange::InitReservation(v8::PageAllocator* page_allocator,
+                                size_t requested) {
+  DCHECK_NE(requested, 0);
+
+  if (requested <= kMinimumCodeRangeSize) {
+    requested = kMinimumCodeRangeSize;
+  }
+  const size_t reserved_area =
+      kReservedCodeRangePages * MemoryAllocator::GetCommitPageSize();
+  if (requested < (kMaximalCodeRangeSize - reserved_area)) {
+    requested += RoundUp(reserved_area, MemoryChunk::kPageSize);
+    // Fullfilling both reserved pages requirement and huge code area
+    // alignments is not supported (requires re-implementation).
+    DCHECK_LE(kMinExpectedOSPageSize, page_allocator->AllocatePageSize());
+  }
+  DCHECK_IMPLIES(kPlatformRequiresCodeRange,
+                 requested <= kMaximalCodeRangeSize);
+
+  VirtualMemoryCage::ReservationParams params;
+  params.page_allocator = page_allocator;
+  params.reservation_size = requested;
+  params.base_alignment =
+      VirtualMemoryCage::ReservationParams::kAnyBaseAlignment;
+  params.base_bias_size = reserved_area;
+  params.page_size = MemoryChunk::kPageSize;
+  params.requested_start_hint =
+      GetCodeRangeAddressHint()->GetAddressHint(requested);
+
+  if (!VirtualMemoryCage::InitReservation(params)) return false;
+
+  // On some platforms, specifically Win64, we need to reserve some pages at
+  // the beginning of an executable space. See
+  //   https://cs.chromium.org/chromium/src/components/crash/content/
+  //     app/crashpad_win.cc?rcl=fd680447881449fba2edcf0589320e7253719212&l=204
+  // for details.
+  if (reserved_area > 0) {
+    if (!reservation()->SetPermissions(reservation()->address(), reserved_area,
+                                       PageAllocator::kReadWrite)) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+void CodeRange::Free() {
+  if (IsReserved()) {
+    GetCodeRangeAddressHint()->NotifyFreedCodeRange(
+        reservation()->region().begin(), reservation()->region().size());
+    VirtualMemoryCage::Free();
+  }
+}
+
+uint8_t* CodeRange::RemapEmbeddedBuiltins(Isolate* isolate,
+                                          const uint8_t* embedded_blob_code,
+                                          size_t embedded_blob_code_size) {
+  base::MutexGuard guard(&remap_embedded_builtins_mutex_);
+
+  const base::AddressRegion& code_region = reservation()->region();
+  CHECK_NE(code_region.begin(), kNullAddress);
+  CHECK(!code_region.is_empty());
+
+  uint8_t* embedded_blob_code_copy =
+      embedded_blob_code_copy_.load(std::memory_order_acquire);
+  if (embedded_blob_code_copy) {
+    DCHECK(
+        code_region.contains(reinterpret_cast<Address>(embedded_blob_code_copy),
+                             embedded_blob_code_size));
+    SLOW_DCHECK(memcmp(embedded_blob_code, embedded_blob_code_copy,
+                       embedded_blob_code_size) == 0);
+    return embedded_blob_code_copy;
+  }
+
+  const size_t kAllocatePageSize = page_allocator()->AllocatePageSize();
+  size_t allocate_code_size =
+      RoundUp(embedded_blob_code_size, kAllocatePageSize);
+
+  // Allocate the re-embedded code blob in the end.
+  void* hint = reinterpret_cast<void*>(code_region.end() - allocate_code_size);
+
+  embedded_blob_code_copy =
+      reinterpret_cast<uint8_t*>(page_allocator()->AllocatePages(
+          hint, allocate_code_size, kAllocatePageSize,
+          PageAllocator::kNoAccess));
+
+  if (!embedded_blob_code_copy) {
+    V8::FatalProcessOutOfMemory(
+        isolate, "Can't allocate space for re-embedded builtins");
+  }
+
+  size_t code_size =
+      RoundUp(embedded_blob_code_size, page_allocator()->CommitPageSize());
+
+  if (!page_allocator()->SetPermissions(embedded_blob_code_copy, code_size,
+                                        PageAllocator::kReadWrite)) {
+    V8::FatalProcessOutOfMemory(isolate,
+                                "Re-embedded builtins: set permissions");
+  }
+  memcpy(embedded_blob_code_copy, embedded_blob_code, embedded_blob_code_size);
+
+  if (!page_allocator()->SetPermissions(embedded_blob_code_copy, code_size,
+                                        PageAllocator::kReadExecute)) {
+    V8::FatalProcessOutOfMemory(isolate,
+                                "Re-embedded builtins: set permissions");
+  }
+
+  embedded_blob_code_copy_.store(embedded_blob_code_copy,
+                                 std::memory_order_release);
+  return embedded_blob_code_copy;
+}
+
+// static
+void CodeRange::InitializeProcessWideCodeRangeOnce(
+    v8::PageAllocator* page_allocator, size_t requested_size) {
+  *GetProcessWideCodeRangeCage() = std::make_shared<CodeRange>();
+  if (!GetProcessWideCodeRange()->InitReservation(page_allocator,
+                                                  requested_size)) {
+    V8::FatalProcessOutOfMemory(
+        nullptr, "Failed to reserve virtual memory for CodeRange");
+  }
+}
+
+// static
+std::shared_ptr<CodeRange> CodeRange::GetProcessWideCodeRange() {
+  return *GetProcessWideCodeRangeCage();
+}
+
+}  // namespace internal
+}  // namespace v8
diff --git a/chromium/v8/src/heap/code-range.h b/chromium/v8/src/heap/code-range.h
new file mode 100644
index 00000000000..b1bc6020b58
--- /dev/null
+++ b/chromium/v8/src/heap/code-range.h
@@ -0,0 +1,147 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_HEAP_CODE_RANGE_H_
+#define V8_HEAP_CODE_RANGE_H_
+
+#include <unordered_map>
+#include <vector>
+
+#include "src/base/platform/mutex.h"
+#include "src/common/globals.h"
+#include "src/utils/allocation.h"
+
+namespace v8 {
+namespace internal {
+
+// The process-wide singleton that keeps track of code range regions with the
+// intention to reuse free code range regions as a workaround for CFG memory
+// leaks (see crbug.com/870054).
+class CodeRangeAddressHint {
+ public:
+  // Returns the most recently freed code range start address for the given
+  // size. If there is no such entry, then a random address is returned.
+  V8_EXPORT_PRIVATE Address GetAddressHint(size_t code_range_size);
+
+  V8_EXPORT_PRIVATE void NotifyFreedCodeRange(Address code_range_start,
+                                              size_t code_range_size);
+
+ private:
+  base::Mutex mutex_;
+  // A map from code range size to an array of recently freed code range
+  // addresses. There should be O(1) different code range sizes.
+  // The length of each array is limited by the peak number of code ranges,
+  // which should be also O(1).
+  std::unordered_map<size_t, std::vector<Address>> recently_freed_;
+};
+
+// A code range is a virtual memory cage that may contain executable code. It
+// has the following layout.
+//
+// +------------+-----+----------------  ~~~  -+
+// |     RW     | ... |    ...                 |
+// +------------+-----+----------------- ~~~  -+
+// ^            ^     ^
+// start        base  allocatable base
+//
+// <------------>     <------------------------>
+//   reserved            allocatable region
+// <------------------------------------------->
+//               code region
+//
+// The start of the reservation may include reserved page with read-write access
+// as required by some platforms (Win64). The cage's page allocator does not
+// control the optional reserved page in the beginning of the code region.
+//
+// The following conditions hold:
+// 1) |reservation()->region()| >= |optional RW pages| +
+//    |reservation()->page_allocator()|
+// 2) |reservation()| is AllocatePageSize()-aligned
+// 3) |reservation()->page_allocator()| (i.e. allocatable base) is
+//    MemoryChunk::kAlignment-aligned
+// 4) |base()| is CommitPageSize()-aligned
+class CodeRange final : public VirtualMemoryCage {
+ public:
+  V8_EXPORT_PRIVATE ~CodeRange();
+
+  uint8_t* embedded_blob_code_copy() const {
+    // remap_embedded_builtins_mutex_ is designed to protect write contention to
+    // embedded_blob_code_copy_. It is safe to be read without taking the
+    // mutex. It is read to check if short builtins ought to be enabled because
+    // a shared CodeRange has already remapped builtins and to find where the
+    // instruction stream for a builtin is.
+    //
+    // For the first, this racing with an Isolate calling RemapEmbeddedBuiltins
+    // may result in disabling short builtins, which is not a correctness issue.
+    //
+    // For the second, this racing with an Isolate calling RemapEmbeddedBuiltins
+    // may result in an already running Isolate that did not have short builtins
+    // enabled (due to max old generation size) to switch over to using remapped
+    // builtins, which is also not a correctness issue as the remapped builtins
+    // are byte-equivalent.
+    //
+    // Both these scenarios should be rare. The initial Isolate is usually
+    // created by itself, i.e. without contention. Additionally, the first
+    // Isolate usually remaps builtins on machines with enough memory, not
+    // subsequent Isolates in the same process.
+    return embedded_blob_code_copy_.load(std::memory_order_acquire);
+  }
+
+#ifdef V8_OS_WIN64
+  // 64-bit Windows needs to track how many Isolates are using the CodeRange for
+  // registering and unregistering of unwind info. Note that even though
+  // CodeRanges are used with std::shared_ptr, std::shared_ptr::use_count should
+  // not be used for synchronization as it's usually implemented with a relaxed
+  // read.
+  uint32_t AtomicIncrementUnwindInfoUseCount() {
+    return unwindinfo_use_count_.fetch_add(1, std::memory_order_acq_rel);
+  }
+
+  uint32_t AtomicDecrementUnwindInfoUseCount() {
+    return unwindinfo_use_count_.fetch_sub(1, std::memory_order_acq_rel);
+  }
+#endif  // V8_OS_WIN64
+
+  bool InitReservation(v8::PageAllocator* page_allocator, size_t requested);
+
+  void Free();
+
+  // Remap and copy the embedded builtins into this CodeRange. This method is
+  // idempotent and only performs the copy once. This property is so that this
+  // method can be used uniformly regardless of having a per-Isolate or a shared
+  // pointer cage. Returns the address of the copy.
+  //
+  // The builtins code region will be freed with the code range at tear down.
+  //
+  // When ENABLE_SLOW_DCHECKS is on, the contents of the embedded_blob_code are
+  // compared against the already copied version.
+  uint8_t* RemapEmbeddedBuiltins(Isolate* isolate,
+                                 const uint8_t* embedded_blob_code,
+                                 size_t embedded_blob_code_size);
+
+  static void InitializeProcessWideCodeRangeOnce(
+      v8::PageAllocator* page_allocator, size_t requested_size);
+
+  // If InitializeProcessWideCodeRangeOnce has been called, returns the
+  // initialized CodeRange. Otherwise returns an empty std::shared_ptr.
+  V8_EXPORT_PRIVATE static std::shared_ptr<CodeRange> GetProcessWideCodeRange();
+
+ private:
+  // Used when short builtin calls are enabled, where embedded builtins are
+  // copied into the CodeRange so calls can be nearer.
+  std::atomic<uint8_t*> embedded_blob_code_copy_{nullptr};
+
+  // When sharing a CodeRange among Isolates, calls to RemapEmbeddedBuiltins may
+  // race during Isolate::Init.
+  base::Mutex remap_embedded_builtins_mutex_;
+
+#ifdef V8_OS_WIN64
+  std::atomic<uint32_t> unwindinfo_use_count_{0};
+#endif
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_HEAP_CODE_RANGE_H_
diff --git a/chromium/v8/src/heap/collection-barrier.cc b/chromium/v8/src/heap/collection-barrier.cc
index 92007690aa7..feeb23d0008 100644
--- a/chromium/v8/src/heap/collection-barrier.cc
+++ b/chromium/v8/src/heap/collection-barrier.cc
@@ -22,8 +22,7 @@ bool CollectionBarrier::CollectionRequested() {
 }
 
 LocalHeap::ThreadState CollectionBarrier::main_thread_state_relaxed() {
-  LocalHeap* main_thread_local_heap =
-      heap_->isolate()->main_thread_local_heap();
+  LocalHeap* main_thread_local_heap = heap_->main_thread_local_heap();
   return main_thread_local_heap->state_relaxed();
 }
 
diff --git a/chromium/v8/src/heap/combined-heap.h b/chromium/v8/src/heap/combined-heap.h
index 55664114d39..9c9ed9039fc 100644
--- a/chromium/v8/src/heap/combined-heap.h
+++ b/chromium/v8/src/heap/combined-heap.h
@@ -36,7 +36,8 @@ V8_WARN_UNUSED_RESULT inline bool IsValidHeapObject(Heap* heap,
   if (V8_ENABLE_THIRD_PARTY_HEAP_BOOL)
     return third_party_heap::Heap::IsValidHeapObject(object);
   else
-    return ReadOnlyHeap::Contains(object) || heap->Contains(object);
+    return ReadOnlyHeap::Contains(object) || heap->Contains(object) ||
+           heap->SharedHeapContains(object);
 }
 
 }  // namespace internal
diff --git a/chromium/v8/src/heap/concurrent-allocator-inl.h b/chromium/v8/src/heap/concurrent-allocator-inl.h
index c92b91ca476..07d669b17cb 100644
--- a/chromium/v8/src/heap/concurrent-allocator-inl.h
+++ b/chromium/v8/src/heap/concurrent-allocator-inl.h
@@ -20,6 +20,7 @@ namespace internal {
 AllocationResult ConcurrentAllocator::AllocateRaw(int object_size,
                                                   AllocationAlignment alignment,
                                                   AllocationOrigin origin) {
+  DCHECK(!FLAG_enable_third_party_heap);
   // TODO(dinfuehr): Add support for allocation observers
 #ifdef DEBUG
   local_heap_->VerifyCurrent();
diff --git a/chromium/v8/src/heap/concurrent-marking.cc b/chromium/v8/src/heap/concurrent-marking.cc
index eb1511f71d9..6f0aa89ebdd 100644
--- a/chromium/v8/src/heap/concurrent-marking.cc
+++ b/chromium/v8/src/heap/concurrent-marking.cc
@@ -8,6 +8,7 @@
 #include <unordered_map>
 
 #include "include/v8config.h"
+#include "src/common/globals.h"
 #include "src/execution/isolate.h"
 #include "src/heap/gc-tracer.h"
 #include "src/heap/heap-inl.h"
@@ -136,13 +137,13 @@ class ConcurrentMarkingVisitor final
   int VisitSeqOneByteString(Map map, SeqOneByteString object) {
     if (!ShouldVisit(object)) return 0;
     VisitMapPointer(object);
-    return SeqOneByteString::SizeFor(object.synchronized_length());
+    return SeqOneByteString::SizeFor(object.length(kAcquireLoad));
   }
 
   int VisitSeqTwoByteString(Map map, SeqTwoByteString object) {
     if (!ShouldVisit(object)) return 0;
     VisitMapPointer(object);
-    return SeqTwoByteString::SizeFor(object.synchronized_length());
+    return SeqTwoByteString::SizeFor(object.length(kAcquireLoad));
   }
 
   // Implements ephemeron semantics: Marks value if key is already reachable.
@@ -232,9 +233,9 @@ class ConcurrentMarkingVisitor final
 
   template <typename T>
   int VisitLeftTrimmableArray(Map map, T object) {
-    // The synchronized_length() function checks that the length is a Smi.
+    // The length() function checks that the length is a Smi.
     // This is not necessarily the case if the array is being left-trimmed.
-    Object length = object.unchecked_synchronized_length();
+    Object length = object.unchecked_length(kAcquireLoad);
     if (!ShouldVisit(object)) return 0;
     // The cached length must be the actual length as the array is not black.
     // Left trimming marks the array black before over-writing the length.
@@ -460,16 +461,28 @@ void ConcurrentMarking::Run(JobDelegate* delegate,
           break;
         }
         objects_processed++;
-        // The order of the two loads is important.
-        Address new_space_top = heap_->new_space()->original_top_acquire();
-        Address new_space_limit = heap_->new_space()->original_limit_relaxed();
-        Address new_large_object = heap_->new_lo_space()->pending_object();
+
+        Address new_space_top = kNullAddress;
+        Address new_space_limit = kNullAddress;
+        Address new_large_object = kNullAddress;
+
+        if (heap_->new_space()) {
+          // The order of the two loads is important.
+          new_space_top = heap_->new_space()->original_top_acquire();
+          new_space_limit = heap_->new_space()->original_limit_relaxed();
+        }
+
+        if (heap_->new_lo_space()) {
+          new_large_object = heap_->new_lo_space()->pending_object();
+        }
+
         Address addr = object.address();
+
         if ((new_space_top <= addr && addr < new_space_limit) ||
             addr == new_large_object) {
           local_marking_worklists.PushOnHold(object);
         } else {
-          Map map = object.synchronized_map(isolate);
+          Map map = object.map(isolate, kAcquireLoad);
           if (is_per_context_mode) {
             Address context;
             if (native_context_inferrer.Infer(isolate, map, object, &context)) {
diff --git a/chromium/v8/src/heap/cppgc-js/cpp-heap.cc b/chromium/v8/src/heap/cppgc-js/cpp-heap.cc
index 636f666521b..006c35808f3 100644
--- a/chromium/v8/src/heap/cppgc-js/cpp-heap.cc
+++ b/chromium/v8/src/heap/cppgc-js/cpp-heap.cc
@@ -5,6 +5,8 @@
 #include "src/heap/cppgc-js/cpp-heap.h"
 
 #include <cstdint>
+#include <memory>
+#include <numeric>
 
 #include "include/cppgc/heap-consistency.h"
 #include "include/cppgc/platform.h"
@@ -29,6 +31,7 @@
 #include "src/heap/cppgc/marking-visitor.h"
 #include "src/heap/cppgc/object-allocator.h"
 #include "src/heap/cppgc/prefinalizer-handler.h"
+#include "src/heap/cppgc/raw-heap.h"
 #include "src/heap/cppgc/stats-collector.h"
 #include "src/heap/cppgc/sweeper.h"
 #include "src/heap/embedder-tracing.h"
@@ -65,6 +68,13 @@ cppgc::HeapStatistics CppHeap::CollectStatistics(
       detail_level);
 }
 
+void CppHeap::CollectCustomSpaceStatisticsAtLastGC(
+    std::vector<cppgc::CustomSpaceIndex> custom_spaces,
+    std::unique_ptr<CustomSpaceStatisticsReceiver> receiver) {
+  return internal::CppHeap::From(this)->CollectCustomSpaceStatisticsAtLastGC(
+      std::move(custom_spaces), std::move(receiver));
+}
+
 void CppHeap::EnableDetachedGarbageCollectionsForTesting() {
   return internal::CppHeap::From(this)
       ->EnableDetachedGarbageCollectionsForTesting();
@@ -200,7 +210,7 @@ UnifiedHeapMarker::UnifiedHeapMarker(Key key, Heap* v8_heap,
 
 void UnifiedHeapMarker::AddObject(void* object) {
   mutator_marking_state_.MarkAndPush(
-      cppgc::internal::HeapObjectHeader::FromPayload(object));
+      cppgc::internal::HeapObjectHeader::FromObject(object));
 }
 
 }  // namespace
@@ -318,10 +328,6 @@ void CppHeap::TracePrologue(TraceFlags flags) {
 }
 
 bool CppHeap::AdvanceTracing(double deadline_in_ms) {
-  // TODO(chromium:1154636): The kAtomicMark/kIncrementalMark scope below is
-  // needed for recording all cpp marking time. Note that it can lead to double
-  // accounting since this scope is also accounted under an outer v8 scope.
-  // Make sure to only account this scope once.
   cppgc::internal::StatsCollector::EnabledScope stats_scope(
       stats_collector(),
       in_atomic_pause_ ? cppgc::internal::StatsCollector::kAtomicMark
@@ -342,8 +348,6 @@ bool CppHeap::IsTracingDone() { return marking_done_; }
 
 void CppHeap::EnterFinalPause(EmbedderStackState stack_state) {
   CHECK(!in_disallow_gc_scope());
-  cppgc::internal::StatsCollector::EnabledScope stats_scope(
-      stats_collector(), cppgc::internal::StatsCollector::kAtomicMark);
   in_atomic_pause_ = true;
   if (override_stack_state_) {
     stack_state = *override_stack_state_;
@@ -359,8 +363,6 @@ void CppHeap::TraceEpilogue(TraceSummary* trace_summary) {
   CHECK(in_atomic_pause_);
   CHECK(marking_done_);
   {
-    cppgc::internal::StatsCollector::EnabledScope stats_scope(
-        stats_collector(), cppgc::internal::StatsCollector::kAtomicMark);
     cppgc::subtle::DisallowGarbageCollectionScope disallow_gc_scope(*this);
     marker_->LeaveAtomicPause();
   }
@@ -376,7 +378,8 @@ void CppHeap::TraceEpilogue(TraceSummary* trace_summary) {
   // TODO(chromium:1056170): replace build flag with dedicated flag.
 #if DEBUG
   UnifiedHeapMarkingVerifier verifier(*this);
-  verifier.Run(stack_state_of_prev_gc_);
+  verifier.Run(stack_state_of_prev_gc(), stack_end_of_current_gc(),
+               stats_collector()->marked_bytes());
 #endif
 
   {
@@ -422,12 +425,17 @@ void CppHeap::ReportBufferedAllocationSizeIfPossible() {
     return;
   }
 
-  if (buffered_allocated_bytes_ < 0) {
-    DecreaseAllocatedSize(static_cast<size_t>(-buffered_allocated_bytes_));
+  // The calls below may trigger full GCs that are synchronous and also execute
+  // epilogue callbacks. Since such callbacks may allocate, the counter must
+  // already be zeroed by that time.
+  const int64_t bytes_to_report = buffered_allocated_bytes_;
+  buffered_allocated_bytes_ = 0;
+
+  if (bytes_to_report < 0) {
+    DecreaseAllocatedSize(static_cast<size_t>(-bytes_to_report));
   } else {
-    IncreaseAllocatedSize(static_cast<size_t>(buffered_allocated_bytes_));
+    IncreaseAllocatedSize(static_cast<size_t>(bytes_to_report));
   }
-  buffered_allocated_bytes_ = 0;
 }
 
 void CppHeap::CollectGarbageForTesting(
@@ -437,6 +445,8 @@ void CppHeap::CollectGarbageForTesting(
   // Finish sweeping in case it is still running.
   sweeper().FinishIfRunning();
 
+  SetStackEndOfCurrentGC(v8::base::Stack::GetCurrentStackPosition());
+
   if (isolate_) {
     // Go through EmbedderHeapTracer API and perform a unified heap collection.
     GarbageCollectionForTesting(stack_state);
@@ -481,5 +491,82 @@ void CppHeap::FinalizeIncrementalGarbageCollectionForTesting(
   sweeper_.FinishIfRunning();
 }
 
+namespace {
+
+void ReportCustomSpaceStatistics(
+    cppgc::internal::RawHeap& raw_heap,
+    std::vector<cppgc::CustomSpaceIndex> custom_spaces,
+    std::unique_ptr<CustomSpaceStatisticsReceiver> receiver) {
+  for (auto custom_space_index : custom_spaces) {
+    const cppgc::internal::BaseSpace* space =
+        raw_heap.CustomSpace(custom_space_index);
+    size_t allocated_bytes = std::accumulate(
+        space->begin(), space->end(), 0, [](size_t sum, auto* page) {
+          return sum + page->AllocatedBytesAtLastGC();
+        });
+    receiver->AllocatedBytes(custom_space_index, allocated_bytes);
+  }
+}
+
+class CollectCustomSpaceStatisticsAtLastGCTask final : public v8::Task {
+ public:
+  static constexpr v8::base::TimeDelta kTaskDelayMs =
+      v8::base::TimeDelta::FromMilliseconds(10);
+
+  CollectCustomSpaceStatisticsAtLastGCTask(
+      cppgc::internal::HeapBase& heap,
+      std::vector<cppgc::CustomSpaceIndex> custom_spaces,
+      std::unique_ptr<CustomSpaceStatisticsReceiver> receiver)
+      : heap_(heap),
+        custom_spaces_(std::move(custom_spaces)),
+        receiver_(std::move(receiver)) {}
+
+  void Run() final {
+    cppgc::internal::Sweeper& sweeper = heap_.sweeper();
+    if (sweeper.PerformSweepOnMutatorThread(
+            heap_.platform()->MonotonicallyIncreasingTime() +
+            kStepSizeMs.InSecondsF())) {
+      // Sweeping is done.
+      DCHECK(!sweeper.IsSweepingInProgress());
+      ReportCustomSpaceStatistics(heap_.raw_heap(), std::move(custom_spaces_),
+                                  std::move(receiver_));
+    } else {
+      heap_.platform()->GetForegroundTaskRunner()->PostDelayedTask(
+          std::make_unique<CollectCustomSpaceStatisticsAtLastGCTask>(
+              heap_, std::move(custom_spaces_), std::move(receiver_)),
+          kTaskDelayMs.InSecondsF());
+    }
+  }
+
+ private:
+  static constexpr v8::base::TimeDelta kStepSizeMs =
+      v8::base::TimeDelta::FromMilliseconds(5);
+
+  cppgc::internal::HeapBase& heap_;
+  std::vector<cppgc::CustomSpaceIndex> custom_spaces_;
+  std::unique_ptr<CustomSpaceStatisticsReceiver> receiver_;
+};
+
+constexpr v8::base::TimeDelta
+    CollectCustomSpaceStatisticsAtLastGCTask::kTaskDelayMs;
+constexpr v8::base::TimeDelta
+    CollectCustomSpaceStatisticsAtLastGCTask::kStepSizeMs;
+
+}  // namespace
+
+void CppHeap::CollectCustomSpaceStatisticsAtLastGC(
+    std::vector<cppgc::CustomSpaceIndex> custom_spaces,
+    std::unique_ptr<CustomSpaceStatisticsReceiver> receiver) {
+  if (sweeper().IsSweepingInProgress()) {
+    platform()->GetForegroundTaskRunner()->PostDelayedTask(
+        std::make_unique<CollectCustomSpaceStatisticsAtLastGCTask>(
+            AsBase(), std::move(custom_spaces), std::move(receiver)),
+        CollectCustomSpaceStatisticsAtLastGCTask::kTaskDelayMs.InSecondsF());
+    return;
+  }
+  ReportCustomSpaceStatistics(raw_heap(), std::move(custom_spaces),
+                              std::move(receiver));
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/heap/cppgc-js/cpp-heap.h b/chromium/v8/src/heap/cppgc-js/cpp-heap.h
index b13fd25a323..cf99b8fe602 100644
--- a/chromium/v8/src/heap/cppgc-js/cpp-heap.h
+++ b/chromium/v8/src/heap/cppgc-js/cpp-heap.h
@@ -5,6 +5,11 @@
 #ifndef V8_HEAP_CPPGC_JS_CPP_HEAP_H_
 #define V8_HEAP_CPPGC_JS_CPP_HEAP_H_
 
+#if CPPGC_IS_STANDALONE
+static_assert(
+    false, "V8 targets can not be built with cppgc_is_standalone set to true.");
+#endif
+
 #include "include/v8-cppgc.h"
 #include "include/v8.h"
 #include "src/base/macros.h"
@@ -55,6 +60,10 @@ class V8_EXPORT_PRIVATE CppHeap final
   void CollectGarbageForTesting(
       cppgc::internal::GarbageCollector::Config::StackState);
 
+  void CollectCustomSpaceStatisticsAtLastGC(
+      std::vector<cppgc::CustomSpaceIndex>,
+      std::unique_ptr<CustomSpaceStatisticsReceiver>);
+
   // v8::EmbedderHeapTracer interface.
   void RegisterV8References(
       const std::vector<std::pair<void*, void*> >& embedder_fields) final;
diff --git a/chromium/v8/src/heap/cppgc-js/cpp-snapshot.cc b/chromium/v8/src/heap/cppgc-js/cpp-snapshot.cc
index 79a863e3026..17929247ee4 100644
--- a/chromium/v8/src/heap/cppgc-js/cpp-snapshot.cc
+++ b/chromium/v8/src/heap/cppgc-js/cpp-snapshot.cc
@@ -382,7 +382,7 @@ class CppGraphBuilderImpl final {
   EmbedderNode* AddNode(const HeapObjectHeader& header) {
     return static_cast<EmbedderNode*>(
         graph_.AddNode(std::unique_ptr<v8::EmbedderGraph::Node>{
-            new EmbedderNode(header.GetName().value, header.GetSize())}));
+            new EmbedderNode(header.GetName().value, header.AllocatedSize())}));
   }
 
   void AddEdge(State& parent, const HeapObjectHeader& header) {
@@ -418,7 +418,7 @@ class CppGraphBuilderImpl final {
 
       if (HasEmbedderDataBackref(
               reinterpret_cast<v8::internal::Isolate*>(cpp_heap_.isolate()),
-              v8_value, parent.header()->Payload())) {
+              v8_value, parent.header()->ObjectStart())) {
         parent.get_node()->SetWrapperNode(v8_node);
 
         auto* profiler =
@@ -512,7 +512,7 @@ class VisiblityVisitor final : public JSVisitor {
   void Visit(const void*, cppgc::TraceDescriptor desc) final {
     graph_builder_.VisitForVisibility(
         &parent_scope_.ParentAsRegularState(),
-        HeapObjectHeader::FromPayload(desc.base_object_payload));
+        HeapObjectHeader::FromObject(desc.base_object_payload));
   }
   void VisitRoot(const void*, cppgc::TraceDescriptor,
                  const cppgc::SourceLocation&) final {}
@@ -556,13 +556,13 @@ class GraphBuildingVisitor final : public JSVisitor {
   void Visit(const void*, cppgc::TraceDescriptor desc) final {
     graph_builder_.AddEdge(
         parent_scope_.ParentAsRegularState(),
-        HeapObjectHeader::FromPayload(desc.base_object_payload));
+        HeapObjectHeader::FromObject(desc.base_object_payload));
   }
   void VisitRoot(const void*, cppgc::TraceDescriptor desc,
                  const cppgc::SourceLocation& loc) final {
     graph_builder_.VisitRootForGraphBuilding(
         parent_scope_.ParentAsRootState(),
-        HeapObjectHeader::FromPayload(desc.base_object_payload), loc);
+        HeapObjectHeader::FromObject(desc.base_object_payload), loc);
   }
   void VisitWeakRoot(const void*, cppgc::TraceDescriptor, cppgc::WeakCallback,
                      const void*, const cppgc::SourceLocation&) final {}
diff --git a/chromium/v8/src/heap/cppgc-js/unified-heap-marking-verifier.cc b/chromium/v8/src/heap/cppgc-js/unified-heap-marking-verifier.cc
index ea14b520480..b0f8595ec74 100644
--- a/chromium/v8/src/heap/cppgc-js/unified-heap-marking-verifier.cc
+++ b/chromium/v8/src/heap/cppgc-js/unified-heap-marking-verifier.cc
@@ -35,7 +35,7 @@ class UnifiedHeapVerificationVisitor final : public JSVisitor {
 
   void VisitWeakContainer(const void* object, cppgc::TraceDescriptor,
                           cppgc::TraceDescriptor weak_desc, cppgc::WeakCallback,
-                          const void*) {
+                          const void*) final {
     if (!object) return;
 
     // Contents of weak containers are found themselves through page iteration
@@ -58,13 +58,8 @@ class UnifiedHeapVerificationVisitor final : public JSVisitor {
 UnifiedHeapMarkingVerifier::UnifiedHeapMarkingVerifier(
     cppgc::internal::HeapBase& heap_base)
     : MarkingVerifierBase(
-          heap_base, std::make_unique<UnifiedHeapVerificationVisitor>(state_)) {
-}
-
-void UnifiedHeapMarkingVerifier::SetCurrentParent(
-    const cppgc::internal::HeapObjectHeader* parent) {
-  state_.SetCurrentParent(parent);
-}
+          heap_base, state_,
+          std::make_unique<UnifiedHeapVerificationVisitor>(state_)) {}
 
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/heap/cppgc-js/unified-heap-marking-verifier.h b/chromium/v8/src/heap/cppgc-js/unified-heap-marking-verifier.h
index 3a54b4dd323..bb2ac09e385 100644
--- a/chromium/v8/src/heap/cppgc-js/unified-heap-marking-verifier.h
+++ b/chromium/v8/src/heap/cppgc-js/unified-heap-marking-verifier.h
@@ -16,8 +16,6 @@ class V8_EXPORT_PRIVATE UnifiedHeapMarkingVerifier final
   explicit UnifiedHeapMarkingVerifier(cppgc::internal::HeapBase&);
   ~UnifiedHeapMarkingVerifier() final = default;
 
-  void SetCurrentParent(const cppgc::internal::HeapObjectHeader*) final;
-
  private:
   // TODO(chromium:1056170): Use a verification state that can handle JS
   // references.
diff --git a/chromium/v8/src/heap/cppgc/caged-heap.cc b/chromium/v8/src/heap/cppgc/caged-heap.cc
index 951fb0e853c..3a8304f4481 100644
--- a/chromium/v8/src/heap/cppgc/caged-heap.cc
+++ b/chromium/v8/src/heap/cppgc/caged-heap.cc
@@ -45,6 +45,27 @@ VirtualMemory ReserveCagedHeap(PageAllocator* platform_allocator) {
   UNREACHABLE();
 }
 
+class CppgcBoundedPageAllocator final : public v8::base::BoundedPageAllocator {
+ public:
+  CppgcBoundedPageAllocator(v8::PageAllocator* page_allocator, Address start,
+                            size_t size, size_t allocate_page_size)
+      : BoundedPageAllocator(page_allocator, start, size, allocate_page_size) {}
+
+  bool FreePages(void* address, size_t size) final {
+    // BoundedPageAllocator is not guaranteed to allocate zeroed page.
+    // Specifically it is possible that BPA frees a page and then tries to
+    // reallocate the same page before the OS has had a chance to asyncroniously
+    // reclaim that page. In such cases, the contents of the page would not have
+    // been cleared by the OS and the reallocated page will keep its previous
+    // contents. To mitigate this problem, CppgcBoundedPageAllocator clears all
+    // pages before they are freed. This also includes protected guard pages, so
+    // CppgcBoundedPageAllocator needs to update permissions before clearing.
+    SetPermissions(address, size, Permission::kReadWrite);
+    memset(address, 0, size);
+    return v8::base::BoundedPageAllocator::FreePages(address, size);
+  }
+};
+
 }  // namespace
 
 CagedHeap::CagedHeap(HeapBase* heap_base, PageAllocator* platform_allocator)
@@ -73,7 +94,7 @@ CagedHeap::CagedHeap(HeapBase* heap_base, PageAllocator* platform_allocator)
       caged_heap_start -
       reinterpret_cast<CagedAddress>(reserved_area_.address());
 
-  bounded_allocator_ = std::make_unique<CagedHeap::AllocatorType>(
+  bounded_allocator_ = std::make_unique<CppgcBoundedPageAllocator>(
       platform_allocator, caged_heap_start,
       reserved_area_.size() - local_data_size_with_padding, kPageSize);
 }
diff --git a/chromium/v8/src/heap/cppgc/compactor.cc b/chromium/v8/src/heap/cppgc/compactor.cc
index f4498e7fbc3..5f687050144 100644
--- a/chromium/v8/src/heap/cppgc/compactor.cc
+++ b/chromium/v8/src/heap/cppgc/compactor.cc
@@ -15,6 +15,7 @@
 #include "src/heap/cppgc/heap-base.h"
 #include "src/heap/cppgc/heap-page.h"
 #include "src/heap/cppgc/heap-space.h"
+#include "src/heap/cppgc/memory.h"
 #include "src/heap/cppgc/object-poisoner.h"
 #include "src/heap/cppgc/raw-heap.h"
 #include "src/heap/cppgc/stats-collector.h"
@@ -129,7 +130,7 @@ void MovableReferences::AddOrFilter(MovableReference* slot) {
            interior_movable_references_.find(slot));
   interior_movable_references_.emplace(slot, nullptr);
 #if DEBUG
-  interior_slot_to_object_.emplace(slot, slot_header.Payload());
+  interior_slot_to_object_.emplace(slot, slot_header.ObjectStart());
 #endif  // DEBUG
 }
 
@@ -144,8 +145,8 @@ void MovableReferences::Relocate(Address from, Address to) {
   // find the corresponding slot A.x. Object A may be moved already and the
   // memory may have been freed, which would result in a crash.
   if (!interior_movable_references_.empty()) {
-    const HeapObjectHeader& header = HeapObjectHeader::FromPayload(to);
-    const size_t size = header.GetSize() - sizeof(HeapObjectHeader);
+    const HeapObjectHeader& header = HeapObjectHeader::FromObject(to);
+    const size_t size = header.ObjectSize();
     RelocateInteriorReferences(from, to, size);
   }
 
@@ -275,14 +276,14 @@ class CompactionState final {
     // Return remaining available pages to the free page pool, decommitting
     // them from the pagefile.
     for (NormalPage* page : available_pages_) {
-      SET_MEMORY_INACCESSIBLE(page->PayloadStart(), page->PayloadSize());
+      SetMemoryInaccessible(page->PayloadStart(), page->PayloadSize());
       NormalPage::Destroy(page);
     }
   }
 
   void FinishCompactingPage(NormalPage* page) {
-#if DEBUG || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER) || \
-    defined(MEMORY_SANITIZER)
+#if DEBUG || defined(V8_USE_MEMORY_SANITIZER) || \
+    defined(V8_USE_ADDRESS_SANITIZER)
     // Zap the unused portion, until it is either compacted into or freed.
     if (current_page_ != page) {
       ZapMemory(page->PayloadStart(), page->PayloadSize());
@@ -303,7 +304,7 @@ class CompactionState final {
           current_page_->PayloadSize() - used_bytes_in_current_page_;
       Address payload = current_page_->PayloadStart();
       Address free_start = payload + used_bytes_in_current_page_;
-      SET_MEMORY_INACCESSIBLE(free_start, freed_size);
+      SetMemoryInaccessible(free_start, freed_size);
       space_->free_list().Add({free_start, freed_size});
       current_page_->object_start_bitmap().SetBit(free_start);
     }
@@ -329,7 +330,7 @@ void CompactPage(NormalPage* page, CompactionState& compaction_state) {
        header_address < page->PayloadEnd();) {
     HeapObjectHeader* header =
         reinterpret_cast<HeapObjectHeader*>(header_address);
-    size_t size = header->GetSize();
+    size_t size = header->AllocatedSize();
     DCHECK_GT(size, 0u);
     DCHECK_LT(size, kPageSize);
 
@@ -349,8 +350,8 @@ void CompactPage(NormalPage* page, CompactionState& compaction_state) {
       // As compaction is under way, leave the freed memory accessible
       // while compacting the rest of the page. We just zap the payload
       // to catch out other finalizers trying to access it.
-#if DEBUG || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER) || \
-    defined(MEMORY_SANITIZER)
+#if DEBUG || defined(V8_USE_MEMORY_SANITIZER) || \
+    defined(V8_USE_ADDRESS_SANITIZER)
       ZapMemory(header, size);
 #endif
       header_address += size;
diff --git a/chromium/v8/src/heap/cppgc/concurrent-marker.cc b/chromium/v8/src/heap/cppgc/concurrent-marker.cc
index 34953b9ec3b..6763515f280 100644
--- a/chromium/v8/src/heap/cppgc/concurrent-marker.cc
+++ b/chromium/v8/src/heap/cppgc/concurrent-marker.cc
@@ -125,7 +125,7 @@ void ConcurrentMarkingTask::ProcessWorklists(
               BasePage::FromPayload(item.base_object_payload)
                   ->SynchronizedLoad();
               const HeapObjectHeader& header =
-                  HeapObjectHeader::FromPayload(item.base_object_payload);
+                  HeapObjectHeader::FromObject(item.base_object_payload);
               DCHECK(!header.IsInConstruction<AccessMode::kAtomic>());
               DCHECK(header.IsMarked<AccessMode::kAtomic>());
               concurrent_marking_state.AccountMarkedBytes(header);
diff --git a/chromium/v8/src/heap/cppgc/explicit-management.cc b/chromium/v8/src/heap/cppgc/explicit-management.cc
index b3ab5f5b515..6e327339aa1 100644
--- a/chromium/v8/src/heap/cppgc/explicit-management.cc
+++ b/chromium/v8/src/heap/cppgc/explicit-management.cc
@@ -9,50 +9,46 @@
 #include "src/heap/cppgc/heap-base.h"
 #include "src/heap/cppgc/heap-object-header.h"
 #include "src/heap/cppgc/heap-page.h"
-#include "src/heap/cppgc/sanitizers.h"
+#include "src/heap/cppgc/memory.h"
 
 namespace cppgc {
 namespace internal {
 
 namespace {
 
-std::pair<bool, BasePage*> CanModifyObject(void* object) {
-  // object is guaranteed to be of type GarbageCollected, so getting the
-  // BasePage is okay for regular and large objects.
-  auto* base_page = BasePage::FromPayload(object);
-  auto* heap = base_page->heap();
+bool InGC(HeapHandle& heap_handle) {
+  const auto& heap = HeapBase::From(heap_handle);
   // Whenever the GC is active, avoid modifying the object as it may mess with
   // state that the GC needs.
-  const bool in_gc = heap->in_atomic_pause() || heap->marker() ||
-                     heap->sweeper().IsSweepingInProgress();
-  return {!in_gc, base_page};
+  return heap.in_atomic_pause() || heap.marker() ||
+         heap.sweeper().IsSweepingInProgress();
 }
 
 }  // namespace
 
-void FreeUnreferencedObject(void* object) {
-  bool can_free;
-  BasePage* base_page;
-  std::tie(can_free, base_page) = CanModifyObject(object);
-  if (!can_free) {
+void FreeUnreferencedObject(HeapHandle& heap_handle, void* object) {
+  if (InGC(heap_handle)) {
     return;
   }
 
-  auto& header = HeapObjectHeader::FromPayload(object);
+  auto& header = HeapObjectHeader::FromObject(object);
   header.Finalize();
 
+  // `object` is guaranteed to be of type GarbageCollected, so getting the
+  // BasePage is okay for regular and large objects.
+  BasePage* base_page = BasePage::FromPayload(object);
   if (base_page->is_large()) {  // Large object.
     base_page->space()->RemovePage(base_page);
     base_page->heap()->stats_collector()->NotifyExplicitFree(
         LargePage::From(base_page)->PayloadSize());
     LargePage::Destroy(LargePage::From(base_page));
   } else {  // Regular object.
-    const size_t header_size = header.GetSize();
+    const size_t header_size = header.AllocatedSize();
     auto* normal_page = NormalPage::From(base_page);
     auto& normal_space = *static_cast<NormalPageSpace*>(base_page->space());
     auto& lab = normal_space.linear_allocation_buffer();
-    ConstAddress payload_end = header.PayloadEnd();
-    SET_MEMORY_INACCESSIBLE(&header, header_size);
+    ConstAddress payload_end = header.ObjectEnd();
+    SetMemoryInaccessible(&header, header_size);
     if (payload_end == lab.start()) {  // Returning to LAB.
       lab.Set(reinterpret_cast<Address>(&header), lab.size() + header_size);
       normal_page->object_start_bitmap().ClearBit(lab.start());
@@ -69,18 +65,18 @@ namespace {
 
 bool Grow(HeapObjectHeader& header, BasePage& base_page, size_t new_size,
           size_t size_delta) {
-  DCHECK_GE(new_size, header.GetSize() + kAllocationGranularity);
+  DCHECK_GE(new_size, header.AllocatedSize() + kAllocationGranularity);
   DCHECK_GE(size_delta, kAllocationGranularity);
   DCHECK(!base_page.is_large());
 
   auto& normal_space = *static_cast<NormalPageSpace*>(base_page.space());
   auto& lab = normal_space.linear_allocation_buffer();
-  if (lab.start() == header.PayloadEnd() && lab.size() >= size_delta) {
+  if (lab.start() == header.ObjectEnd() && lab.size() >= size_delta) {
     // LABs are considered used memory which means that no allocated size
     // adjustments are needed.
     Address delta_start = lab.Allocate(size_delta);
-    SET_MEMORY_ACCESSIBLE(delta_start, size_delta);
-    header.SetSize(new_size);
+    SetMemoryAccessible(delta_start, size_delta);
+    header.SetAllocatedSize(new_size);
     return true;
   }
   return false;
@@ -88,30 +84,30 @@ bool Grow(HeapObjectHeader& header, BasePage& base_page, size_t new_size,
 
 bool Shrink(HeapObjectHeader& header, BasePage& base_page, size_t new_size,
             size_t size_delta) {
-  DCHECK_GE(header.GetSize(), new_size + kAllocationGranularity);
+  DCHECK_GE(header.AllocatedSize(), new_size + kAllocationGranularity);
   DCHECK_GE(size_delta, kAllocationGranularity);
   DCHECK(!base_page.is_large());
 
   auto& normal_space = *static_cast<NormalPageSpace*>(base_page.space());
   auto& lab = normal_space.linear_allocation_buffer();
-  Address free_start = header.PayloadEnd() - size_delta;
-  if (lab.start() == header.PayloadEnd()) {
+  Address free_start = header.ObjectEnd() - size_delta;
+  if (lab.start() == header.ObjectEnd()) {
     DCHECK_EQ(free_start, lab.start() - size_delta);
     // LABs are considered used memory which means that no allocated size
     // adjustments are needed.
     lab.Set(free_start, lab.size() + size_delta);
-    SET_MEMORY_INACCESSIBLE(lab.start(), size_delta);
-    header.SetSize(new_size);
+    SetMemoryInaccessible(lab.start(), size_delta);
+    header.SetAllocatedSize(new_size);
     return true;
   }
   // Heuristic: Only return memory to the free list if the block is larger than
   // the smallest size class.
   if (size_delta >= ObjectAllocator::kSmallestSpaceSize) {
-    SET_MEMORY_INACCESSIBLE(free_start, size_delta);
+    SetMemoryInaccessible(free_start, size_delta);
     base_page.heap()->stats_collector()->NotifyExplicitFree(size_delta);
     normal_space.free_list().Add({free_start, size_delta});
     NormalPage::From(&base_page)->object_start_bitmap().SetBit(free_start);
-    header.SetSize(new_size);
+    header.SetAllocatedSize(new_size);
   }
   // Return success in any case, as we want to avoid that embedders start
   // copying memory because of small deltas.
@@ -121,10 +117,11 @@ bool Shrink(HeapObjectHeader& header, BasePage& base_page, size_t new_size,
 }  // namespace
 
 bool Resize(void* object, size_t new_object_size) {
-  bool can_resize;
-  BasePage* base_page;
-  std::tie(can_resize, base_page) = CanModifyObject(object);
-  if (!can_resize) {
+  // `object` is guaranteed to be of type GarbageCollected, so getting the
+  // BasePage is okay for regular and large objects.
+  BasePage* base_page = BasePage::FromPayload(object);
+
+  if (InGC(*base_page->heap())) {
     return false;
   }
 
@@ -136,8 +133,8 @@ bool Resize(void* object, size_t new_object_size) {
 
   const size_t new_size = RoundUp<kAllocationGranularity>(
       sizeof(HeapObjectHeader) + new_object_size);
-  auto& header = HeapObjectHeader::FromPayload(object);
-  const size_t old_size = header.GetSize();
+  auto& header = HeapObjectHeader::FromObject(object);
+  const size_t old_size = header.AllocatedSize();
 
   if (new_size > old_size) {
     return Grow(header, *base_page, new_size, new_size - old_size);
diff --git a/chromium/v8/src/heap/cppgc/free-list.cc b/chromium/v8/src/heap/cppgc/free-list.cc
index 705d31725ad..600e15312cd 100644
--- a/chromium/v8/src/heap/cppgc/free-list.cc
+++ b/chromium/v8/src/heap/cppgc/free-list.cc
@@ -8,9 +8,9 @@
 
 #include "include/cppgc/internal/logging.h"
 #include "src/base/bits.h"
+#include "src/base/sanitizer/asan.h"
 #include "src/heap/cppgc/globals.h"
 #include "src/heap/cppgc/heap-object-header.h"
-#include "src/heap/cppgc/sanitizers.h"
 
 namespace cppgc {
 namespace internal {
@@ -132,7 +132,7 @@ FreeList::Block FreeList::Allocate(size_t allocation_size) {
       // Final bucket candidate; check initial entry if it is able
       // to service this allocation. Do not perform a linear scan,
       // as it is considered too costly.
-      if (!entry || entry->GetSize() < allocation_size) break;
+      if (!entry || entry->AllocatedSize() < allocation_size) break;
     }
     if (entry) {
       if (!entry->Next()) {
@@ -141,7 +141,7 @@ FreeList::Block FreeList::Allocate(size_t allocation_size) {
       }
       entry->Unlink(&free_list_heads_[index]);
       biggest_free_list_index_ = index;
-      return {entry, entry->GetSize()};
+      return {entry, entry->AllocatedSize()};
     }
   }
   biggest_free_list_index_ = index;
@@ -158,7 +158,7 @@ size_t FreeList::Size() const {
   size_t size = 0;
   for (auto* entry : free_list_heads_) {
     while (entry) {
-      size += entry->GetSize();
+      size += entry->AllocatedSize();
       entry = entry->Next();
     }
   }
@@ -175,7 +175,7 @@ bool FreeList::ContainsForTesting(Block block) const {
     for (Entry* entry = list; entry; entry = entry->Next()) {
       if (entry <= block.address &&
           (reinterpret_cast<Address>(block.address) + block.size <=
-           reinterpret_cast<Address>(entry) + entry->GetSize()))
+           reinterpret_cast<Address>(entry) + entry->AllocatedSize()))
         return true;
     }
   }
@@ -204,7 +204,7 @@ void FreeList::CollectStatistics(
     size_t entry_size = 0;
     for (Entry* entry = free_list_heads_[i]; entry; entry = entry->Next()) {
       ++entry_count;
-      entry_size += entry->GetSize();
+      entry_size += entry->AllocatedSize();
     }
     bucket_size.push_back(static_cast<size_t>(1) << i);
     free_count.push_back(entry_count);
diff --git a/chromium/v8/src/heap/cppgc/gc-info-table.cc b/chromium/v8/src/heap/cppgc/gc-info-table.cc
index 6b177848cbb..7462ba8a21d 100644
--- a/chromium/v8/src/heap/cppgc/gc-info-table.cc
+++ b/chromium/v8/src/heap/cppgc/gc-info-table.cc
@@ -35,8 +35,9 @@ PageAllocator* GetAllocator(PageAllocator* page_allocator) {
         default_page_allocator;
     page_allocator = default_page_allocator.get();
   }
-  // TODO(chromium:1056170): Wrap page_allocator into LsanPageAllocator when
-  // running with LEAK_SANITIZER.
+  // No need to introduce LSAN support for PageAllocator, as `GCInfoTable` is
+  // already a leaky object and the table payload (`GCInfoTable::table_`) should
+  // not refer to dynamically allocated objects.
   return page_allocator;
 }
 
diff --git a/chromium/v8/src/heap/cppgc/heap-base.cc b/chromium/v8/src/heap/cppgc/heap-base.cc
index f89c4c9f112..c7664f09c69 100644
--- a/chromium/v8/src/heap/cppgc/heap-base.cc
+++ b/chromium/v8/src/heap/cppgc/heap-base.cc
@@ -5,8 +5,8 @@
 #include "src/heap/cppgc/heap-base.h"
 
 #include "include/cppgc/heap-consistency.h"
-#include "src/base/bounded-page-allocator.h"
 #include "src/base/platform/platform.h"
+#include "src/base/sanitizer/lsan-page-allocator.h"
 #include "src/heap/base/stack.h"
 #include "src/heap/cppgc/globals.h"
 #include "src/heap/cppgc/heap-object-header.h"
@@ -15,6 +15,7 @@
 #include "src/heap/cppgc/heap-visitor.h"
 #include "src/heap/cppgc/marker.h"
 #include "src/heap/cppgc/marking-verifier.h"
+#include "src/heap/cppgc/object-view.h"
 #include "src/heap/cppgc/page-memory.h"
 #include "src/heap/cppgc/prefinalizer-handler.h"
 #include "src/heap/cppgc/stats-collector.h"
@@ -35,13 +36,7 @@ class ObjectSizeCounter : private HeapVisitor<ObjectSizeCounter> {
 
  private:
   static size_t ObjectSize(const HeapObjectHeader* header) {
-    const size_t size =
-        header->IsLargeObject()
-            ? static_cast<const LargePage*>(BasePage::FromPayload(header))
-                  ->PayloadSize()
-            : header->GetSize();
-    DCHECK_GE(size, sizeof(HeapObjectHeader));
-    return size - sizeof(HeapObjectHeader);
+    return ObjectView(*header).Size();
   }
 
   bool VisitHeapObjectHeader(HeapObjectHeader* header) {
@@ -62,13 +57,16 @@ HeapBase::HeapBase(
     std::unique_ptr<MetricRecorder> histogram_recorder)
     : raw_heap_(this, custom_spaces),
       platform_(std::move(platform)),
+#if defined(LEAK_SANITIZER)
+      lsan_page_allocator_(std::make_unique<v8::base::LsanPageAllocator>(
+          platform_->GetPageAllocator())),
+#endif  // LEAK_SANITIZER
 #if defined(CPPGC_CAGED_HEAP)
-      caged_heap_(this, platform_->GetPageAllocator()),
+      caged_heap_(this, page_allocator()),
       page_backend_(std::make_unique<PageBackend>(&caged_heap_.allocator())),
-#else
-      page_backend_(
-          std::make_unique<PageBackend>(platform_->GetPageAllocator())),
-#endif
+#else   // !CPPGC_CAGED_HEAP
+      page_backend_(std::make_unique<PageBackend>(page_allocator())),
+#endif  // !CPPGC_CAGED_HEAP
       stats_collector_(std::make_unique<StatsCollector>(
           std::move(histogram_recorder), platform_.get())),
       stack_(std::make_unique<heap::base::Stack>(
@@ -85,6 +83,14 @@ HeapBase::HeapBase(
 
 HeapBase::~HeapBase() = default;
 
+PageAllocator* HeapBase::page_allocator() const {
+#if defined(LEAK_SANITIZER)
+  return lsan_page_allocator_.get();
+#else   // !LEAK_SANITIZER
+  return platform_->GetPageAllocator();
+#endif  // !LEAK_SANITIZER
+}
+
 size_t HeapBase::ObjectPayloadSize() const {
   return ObjectSizeCounter().GetSize(const_cast<RawHeap*>(&raw_heap()));
 }
diff --git a/chromium/v8/src/heap/cppgc/heap-base.h b/chromium/v8/src/heap/cppgc/heap-base.h
index f9bdb95c04a..81365417180 100644
--- a/chromium/v8/src/heap/cppgc/heap-base.h
+++ b/chromium/v8/src/heap/cppgc/heap-base.h
@@ -19,6 +19,7 @@
 #include "src/heap/cppgc/metric-recorder.h"
 #include "src/heap/cppgc/object-allocator.h"
 #include "src/heap/cppgc/process-heap-statistics.h"
+#include "src/heap/cppgc/process-heap.h"
 #include "src/heap/cppgc/raw-heap.h"
 #include "src/heap/cppgc/sweeper.h"
 #include "v8config.h"  // NOLINT(build/include_directory)
@@ -27,6 +28,12 @@
 #include "src/heap/cppgc/caged-heap.h"
 #endif
 
+namespace v8 {
+namespace base {
+class LsanPageAllocator;
+}  // namespace base
+}  // namespace v8
+
 namespace heap {
 namespace base {
 class Stack;
@@ -152,6 +159,9 @@ class V8_EXPORT_PRIVATE HeapBase : public cppgc::HeapHandle {
   size_t ObjectPayloadSize() const;
 
   StackSupport stack_support() const { return stack_support_; }
+  const EmbedderStackState* override_stack_state() const {
+    return override_stack_state_.get();
+  }
 
   void AdvanceIncrementalGarbageCollectionOnAllocationIfNeeded();
 
@@ -172,6 +182,11 @@ class V8_EXPORT_PRIVATE HeapBase : public cppgc::HeapHandle {
     stack_state_of_prev_gc_ = stack_state;
   }
 
+  uintptr_t stack_end_of_current_gc() const { return stack_end_of_current_gc_; }
+  void SetStackEndOfCurrentGC(uintptr_t stack_end) {
+    stack_end_of_current_gc_ = stack_end;
+  }
+
   void SetInAtomicPauseForTesting(bool value) { in_atomic_pause_ = value; }
 
   virtual void StartIncrementalGarbageCollectionForTesting() = 0;
@@ -189,11 +204,20 @@ class V8_EXPORT_PRIVATE HeapBase : public cppgc::HeapHandle {
 
   void ExecutePreFinalizers();
 
+  PageAllocator* page_allocator() const;
+
   RawHeap raw_heap_;
   std::shared_ptr<cppgc::Platform> platform_;
+
+#if defined(LEAK_SANITIZER)
+  std::unique_ptr<v8::base::LsanPageAllocator> lsan_page_allocator_;
+#endif  // LEAK_SANITIZER
+
+  HeapRegistry::Subscription heap_registry_subscription_{*this};
+
 #if defined(CPPGC_CAGED_HEAP)
   CagedHeap caged_heap_;
-#endif
+#endif  // CPPGC_CAGED_HEAP
   std::unique_ptr<PageBackend> page_backend_;
 
   std::unique_ptr<StatsCollector> stats_collector_;
@@ -224,6 +248,10 @@ class V8_EXPORT_PRIVATE HeapBase : public cppgc::HeapHandle {
       EmbedderStackState::kNoHeapPointers;
   std::unique_ptr<EmbedderStackState> override_stack_state_;
 
+  // Marker that signals end of the interesting stack region in which on-heap
+  // pointers can be found.
+  uintptr_t stack_end_of_current_gc_ = 0;
+
   bool in_atomic_pause_ = false;
 
   friend class MarkerBase::IncrementalMarkingTask;
diff --git a/chromium/v8/src/heap/cppgc/heap-object-header.cc b/chromium/v8/src/heap/cppgc/heap-object-header.cc
index 0f5530114cb..5ff0e230e7f 100644
--- a/chromium/v8/src/heap/cppgc/heap-object-header.cc
+++ b/chromium/v8/src/heap/cppgc/heap-object-header.cc
@@ -6,9 +6,9 @@
 
 #include "include/cppgc/internal/api-constants.h"
 #include "src/base/macros.h"
+#include "src/base/sanitizer/asan.h"
 #include "src/heap/cppgc/gc-info-table.h"
 #include "src/heap/cppgc/heap-page.h"
-#include "src/heap/cppgc/sanitizers.h"
 
 namespace cppgc {
 namespace internal {
@@ -28,17 +28,17 @@ void HeapObjectHeader::Finalize() {
       IsLargeObject()
           ? LargePage::From(BasePage::FromPayload(this))->ObjectSize()
           : ObjectSize();
-  ASAN_UNPOISON_MEMORY_REGION(Payload(), size);
+  ASAN_UNPOISON_MEMORY_REGION(ObjectStart(), size);
 #endif  // V8_USE_ADDRESS_SANITIZER
   const GCInfo& gc_info = GlobalGCInfoTable::GCInfoFromIndex(GetGCInfoIndex());
   if (gc_info.finalize) {
-    gc_info.finalize(Payload());
+    gc_info.finalize(ObjectStart());
   }
 }
 
 HeapObjectName HeapObjectHeader::GetName() const {
   const GCInfo& gc_info = GlobalGCInfoTable::GCInfoFromIndex(GetGCInfoIndex());
-  return gc_info.name(Payload());
+  return gc_info.name(ObjectStart());
 }
 
 }  // namespace internal
diff --git a/chromium/v8/src/heap/cppgc/heap-object-header.h b/chromium/v8/src/heap/cppgc/heap-object-header.h
index 7e940ca3477..a50d115e52b 100644
--- a/chromium/v8/src/heap/cppgc/heap-object-header.h
+++ b/chromium/v8/src/heap/cppgc/heap-object-header.h
@@ -57,22 +57,22 @@ class HeapObjectHeader {
   static constexpr size_t kMaxSize = (size_t{1} << kSizeLog2) - 1;
   static constexpr uint16_t kLargeObjectSizeInHeader = 0;
 
-  inline static HeapObjectHeader& FromPayload(void* address);
-  inline static const HeapObjectHeader& FromPayload(const void* address);
+  inline static HeapObjectHeader& FromObject(void* address);
+  inline static const HeapObjectHeader& FromObject(const void* address);
 
   inline HeapObjectHeader(size_t size, GCInfoIndex gc_info_index);
 
-  // The payload starts directly after the HeapObjectHeader.
-  inline Address Payload() const;
+  // The object starts directly after the HeapObjectHeader.
+  inline Address ObjectStart() const;
   template <AccessMode mode = AccessMode::kNonAtomic>
-  inline Address PayloadEnd() const;
+  inline Address ObjectEnd() const;
 
   template <AccessMode mode = AccessMode::kNonAtomic>
   inline GCInfoIndex GetGCInfoIndex() const;
 
   template <AccessMode mode = AccessMode::kNonAtomic>
-  inline size_t GetSize() const;
-  inline void SetSize(size_t size);
+  inline size_t AllocatedSize() const;
+  inline void SetAllocatedSize(size_t size);
 
   template <AccessMode mode = AccessMode::kNonAtomic>
   inline size_t ObjectSize() const;
@@ -149,15 +149,15 @@ static_assert(kAllocationGranularity == sizeof(HeapObjectHeader),
               "guarantee alignment");
 
 // static
-HeapObjectHeader& HeapObjectHeader::FromPayload(void* payload) {
-  return *reinterpret_cast<HeapObjectHeader*>(static_cast<Address>(payload) -
+HeapObjectHeader& HeapObjectHeader::FromObject(void* object) {
+  return *reinterpret_cast<HeapObjectHeader*>(static_cast<Address>(object) -
                                               sizeof(HeapObjectHeader));
 }
 
 // static
-const HeapObjectHeader& HeapObjectHeader::FromPayload(const void* payload) {
+const HeapObjectHeader& HeapObjectHeader::FromObject(const void* object) {
   return *reinterpret_cast<const HeapObjectHeader*>(
-      static_cast<ConstAddress>(payload) - sizeof(HeapObjectHeader));
+      static_cast<ConstAddress>(object) - sizeof(HeapObjectHeader));
 }
 
 HeapObjectHeader::HeapObjectHeader(size_t size, GCInfoIndex gc_info_index) {
@@ -183,16 +183,16 @@ HeapObjectHeader::HeapObjectHeader(size_t size, GCInfoIndex gc_info_index) {
 #endif  // DEBUG
 }
 
-Address HeapObjectHeader::Payload() const {
+Address HeapObjectHeader::ObjectStart() const {
   return reinterpret_cast<Address>(const_cast<HeapObjectHeader*>(this)) +
          sizeof(HeapObjectHeader);
 }
 
 template <AccessMode mode>
-Address HeapObjectHeader::PayloadEnd() const {
+Address HeapObjectHeader::ObjectEnd() const {
   DCHECK(!IsLargeObject());
   return reinterpret_cast<Address>(const_cast<HeapObjectHeader*>(this)) +
-         GetSize<mode>();
+         AllocatedSize<mode>();
 }
 
 template <AccessMode mode>
@@ -203,7 +203,7 @@ GCInfoIndex HeapObjectHeader::GetGCInfoIndex() const {
 }
 
 template <AccessMode mode>
-size_t HeapObjectHeader::GetSize() const {
+size_t HeapObjectHeader::AllocatedSize() const {
   // Size is immutable after construction while either marking or sweeping
   // is running so relaxed load (if mode == kAtomic) is enough.
   uint16_t encoded_low_value =
@@ -212,19 +212,21 @@ size_t HeapObjectHeader::GetSize() const {
   return size;
 }
 
-void HeapObjectHeader::SetSize(size_t size) {
+void HeapObjectHeader::SetAllocatedSize(size_t size) {
   DCHECK(!IsMarked());
   encoded_low_ = EncodeSize(size);
 }
 
 template <AccessMode mode>
 size_t HeapObjectHeader::ObjectSize() const {
-  return GetSize<mode>() - sizeof(HeapObjectHeader);
+  // The following DCHECK also fails for large objects.
+  DCHECK_GT(AllocatedSize<mode>(), sizeof(HeapObjectHeader));
+  return AllocatedSize<mode>() - sizeof(HeapObjectHeader);
 }
 
 template <AccessMode mode>
 bool HeapObjectHeader::IsLargeObject() const {
-  return GetSize<mode>() == kLargeObjectSizeInHeader;
+  return AllocatedSize<mode>() == kLargeObjectSizeInHeader;
 }
 
 template <AccessMode mode>
@@ -235,7 +237,8 @@ bool HeapObjectHeader::IsInConstruction() const {
 }
 
 void HeapObjectHeader::MarkAsFullyConstructed() {
-  MakeGarbageCollectedTraitInternal::MarkObjectAsFullyConstructed(Payload());
+  MakeGarbageCollectedTraitInternal::MarkObjectAsFullyConstructed(
+      ObjectStart());
 }
 
 template <AccessMode mode>
@@ -282,7 +285,7 @@ template <AccessMode mode>
 void HeapObjectHeader::Trace(Visitor* visitor) const {
   const GCInfo& gc_info =
       GlobalGCInfoTable::GCInfoFromIndex(GetGCInfoIndex<mode>());
-  return gc_info.trace(visitor, Payload());
+  return gc_info.trace(visitor, ObjectStart());
 }
 
 template <AccessMode mode, HeapObjectHeader::EncodedHalf part,
diff --git a/chromium/v8/src/heap/cppgc/heap-page.cc b/chromium/v8/src/heap/cppgc/heap-page.cc
index d573d675ee4..f65b3fed9b8 100644
--- a/chromium/v8/src/heap/cppgc/heap-page.cc
+++ b/chromium/v8/src/heap/cppgc/heap-page.cc
@@ -69,6 +69,11 @@ ConstAddress BasePage::PayloadEnd() const {
   return const_cast<BasePage*>(this)->PayloadEnd();
 }
 
+size_t BasePage::AllocatedBytesAtLastGC() const {
+  return is_large() ? LargePage::From(this)->AllocatedBytesAtLastGC()
+                    : NormalPage::From(this)->AllocatedBytesAtLastGC();
+}
+
 HeapObjectHeader* BasePage::TryObjectHeaderFromInnerAddress(
     void* address) const {
   return const_cast<HeapObjectHeader*>(
diff --git a/chromium/v8/src/heap/cppgc/heap-page.h b/chromium/v8/src/heap/cppgc/heap-page.h
index 1a66b8593e6..39d5e644ee3 100644
--- a/chromium/v8/src/heap/cppgc/heap-page.h
+++ b/chromium/v8/src/heap/cppgc/heap-page.h
@@ -46,6 +46,10 @@ class V8_EXPORT_PRIVATE BasePage {
   Address PayloadEnd();
   ConstAddress PayloadEnd() const;
 
+  // Returns the size of live objects on the page at the last GC.
+  // The counter is update after sweeping.
+  size_t AllocatedBytesAtLastGC() const;
+
   // |address| must refer to real object.
   template <AccessMode = AccessMode::kNonAtomic>
   HeapObjectHeader& ObjectHeaderFromInnerAddress(void* address) const;
@@ -107,7 +111,7 @@ class V8_EXPORT_PRIVATE NormalPage final : public BasePage {
     bool operator!=(IteratorImpl other) const { return !(*this == other); }
 
     IteratorImpl& operator++() {
-      const size_t size = p_->GetSize();
+      const size_t size = p_->AllocatedSize();
       DCHECK_EQ(0, (size & (sizeof(T) - 1)));
       p_ += (size / sizeof(T));
       if (reinterpret_cast<ConstAddress>(p_) == lab_start_) {
@@ -169,6 +173,12 @@ class V8_EXPORT_PRIVATE NormalPage final : public BasePage {
     return (PayloadStart() <= address) && (address < PayloadEnd());
   }
 
+  size_t AllocatedBytesAtLastGC() const { return allocated_bytes_at_last_gc_; }
+
+  void SetAllocatedBytesAtLastGC(size_t bytes) {
+    allocated_bytes_at_last_gc_ = bytes;
+  }
+
   PlatformAwareObjectStartBitmap& object_start_bitmap() {
     return object_start_bitmap_;
   }
@@ -180,6 +190,7 @@ class V8_EXPORT_PRIVATE NormalPage final : public BasePage {
   NormalPage(HeapBase* heap, BaseSpace* space);
   ~NormalPage();
 
+  size_t allocated_bytes_at_last_gc_ = 0;
   PlatformAwareObjectStartBitmap object_start_bitmap_;
 };
 
@@ -210,7 +221,12 @@ class V8_EXPORT_PRIVATE LargePage final : public BasePage {
   ConstAddress PayloadEnd() const;
 
   size_t PayloadSize() const { return payload_size_; }
-  size_t ObjectSize() const { return payload_size_ - sizeof(HeapObjectHeader); }
+  size_t ObjectSize() const {
+    DCHECK_GT(payload_size_, sizeof(HeapObjectHeader));
+    return payload_size_ - sizeof(HeapObjectHeader);
+  }
+
+  size_t AllocatedBytesAtLastGC() const { return ObjectSize(); }
 
   bool PayloadContains(ConstAddress address) const {
     return (PayloadStart() <= address) && (address < PayloadEnd());
@@ -248,7 +264,7 @@ const HeapObjectHeader* ObjectHeaderFromInnerAddressImpl(const BasePage* page,
   const HeapObjectHeader* header =
       bitmap.FindHeader<mode>(static_cast<ConstAddress>(address));
   DCHECK_LT(address, reinterpret_cast<ConstAddress>(header) +
-                         header->GetSize<AccessMode::kAtomic>());
+                         header->AllocatedSize<AccessMode::kAtomic>());
   return header;
 }
 
diff --git a/chromium/v8/src/heap/cppgc/heap-statistics-collector.cc b/chromium/v8/src/heap/cppgc/heap-statistics-collector.cc
index 961148babd8..ef283e856ad 100644
--- a/chromium/v8/src/heap/cppgc/heap-statistics-collector.cc
+++ b/chromium/v8/src/heap/cppgc/heap-statistics-collector.cc
@@ -148,7 +148,7 @@ bool HeapStatisticsCollector::VisitHeapObjectHeader(HeapObjectHeader* header) {
   DCHECK_NOT_NULL(current_space_stats_);
   DCHECK_NOT_NULL(current_page_stats_);
   if (header->IsFree()) return true;
-  size_t object_size = header->GetSize();
+  size_t object_size = header->AllocatedSize();
   RecordObjectType(current_space_stats_, header, object_size);
   current_page_stats_->used_size_bytes += object_size;
   return true;
diff --git a/chromium/v8/src/heap/cppgc/heap.cc b/chromium/v8/src/heap/cppgc/heap.cc
index c0c9cec9292..dc127f8e51c 100644
--- a/chromium/v8/src/heap/cppgc/heap.cc
+++ b/chromium/v8/src/heap/cppgc/heap.cc
@@ -176,6 +176,7 @@ void Heap::FinalizeGarbageCollection(Config::StackState stack_state) {
   if (override_stack_state_) {
     config_.stack_state = *override_stack_state_;
   }
+  SetStackEndOfCurrentGC(v8::base::Stack::GetCurrentStackPosition());
   in_atomic_pause_ = true;
   {
     // This guards atomic pause marking, meaning that no internal method or
@@ -188,7 +189,8 @@ void Heap::FinalizeGarbageCollection(Config::StackState stack_state) {
   // TODO(chromium:1056170): replace build flag with dedicated flag.
 #if DEBUG
   MarkingVerifier verifier(*this);
-  verifier.Run(config_.stack_state);
+  verifier.Run(config_.stack_state, stack_end_of_current_gc(),
+               stats_collector()->marked_bytes());
 #endif
 
   subtle::NoGarbageCollectionScope no_gc(*this);
diff --git a/chromium/v8/src/heap/cppgc/liveness-broker.cc b/chromium/v8/src/heap/cppgc/liveness-broker.cc
index 8c61268ba81..d3dd457e056 100644
--- a/chromium/v8/src/heap/cppgc/liveness-broker.cc
+++ b/chromium/v8/src/heap/cppgc/liveness-broker.cc
@@ -9,7 +9,7 @@
 namespace cppgc {
 
 bool LivenessBroker::IsHeapObjectAliveImpl(const void* payload) const {
-  return internal::HeapObjectHeader::FromPayload(payload).IsMarked();
+  return internal::HeapObjectHeader::FromObject(payload).IsMarked();
 }
 
 namespace internal {
diff --git a/chromium/v8/src/heap/cppgc/marker.cc b/chromium/v8/src/heap/cppgc/marker.cc
index d30bb0a8ec2..d26fd580df9 100644
--- a/chromium/v8/src/heap/cppgc/marker.cc
+++ b/chromium/v8/src/heap/cppgc/marker.cc
@@ -191,7 +191,7 @@ MarkerBase::~MarkerBase() {
     MarkingWorklists::EphemeronPairItem item;
     while (mutator_marking_state_.discovered_ephemeron_pairs_worklist().Pop(
         &item)) {
-      DCHECK(!HeapObjectHeader::FromPayload(item.key).IsMarked());
+      DCHECK(!HeapObjectHeader::FromObject(item.key).IsMarked());
     }
 #else
     marking_worklists_.discovered_ephemeron_pairs_worklist()->Clear();
@@ -231,6 +231,8 @@ void MarkerBase::StartMarking() {
 }
 
 void MarkerBase::EnterAtomicPause(MarkingConfig::StackState stack_state) {
+  StatsCollector::EnabledScope top_stats_scope(heap().stats_collector(),
+                                               StatsCollector::kAtomicMark);
   StatsCollector::EnabledScope stats_scope(heap().stats_collector(),
                                            StatsCollector::kMarkAtomicPrologue);
 
@@ -261,30 +263,38 @@ void MarkerBase::EnterAtomicPause(MarkingConfig::StackState stack_state) {
 }
 
 void MarkerBase::LeaveAtomicPause() {
-  StatsCollector::EnabledScope stats_scope(heap().stats_collector(),
-                                           StatsCollector::kMarkAtomicEpilogue);
-  DCHECK(!incremental_marking_handle_);
-  ResetRememberedSet(heap());
-  heap().stats_collector()->NotifyMarkingCompleted(
-      // GetOverallMarkedBytes also includes concurrently marked bytes.
-      schedule_.GetOverallMarkedBytes());
-  is_marking_ = false;
+  {
+    StatsCollector::EnabledScope top_stats_scope(heap().stats_collector(),
+                                                 StatsCollector::kAtomicMark);
+    StatsCollector::EnabledScope stats_scope(
+        heap().stats_collector(), StatsCollector::kMarkAtomicEpilogue);
+    DCHECK(!incremental_marking_handle_);
+    ResetRememberedSet(heap());
+    heap().stats_collector()->NotifyMarkingCompleted(
+        // GetOverallMarkedBytes also includes concurrently marked bytes.
+        schedule_.GetOverallMarkedBytes());
+    is_marking_ = false;
+  }
   {
     // Weakness callbacks are forbidden from allocating objects.
     cppgc::subtle::DisallowGarbageCollectionScope disallow_gc_scope(heap_);
     ProcessWeakness();
   }
+  // TODO(chromium:1056170): It would be better if the call to Unlock was
+  // covered by some cppgc scope.
   g_process_mutex.Pointer()->Unlock();
   heap().SetStackStateOfPrevGC(config_.stack_state);
 }
 
 void MarkerBase::FinishMarking(MarkingConfig::StackState stack_state) {
   DCHECK(is_marking_);
-  StatsCollector::EnabledScope stats_scope(heap().stats_collector(),
-                                           StatsCollector::kAtomicMark);
   EnterAtomicPause(stack_state);
-  CHECK(AdvanceMarkingWithLimits(v8::base::TimeDelta::Max(), SIZE_MAX));
-  mutator_marking_state_.Publish();
+  {
+    StatsCollector::EnabledScope stats_scope(heap().stats_collector(),
+                                             StatsCollector::kAtomicMark);
+    CHECK(AdvanceMarkingWithLimits(v8::base::TimeDelta::Max(), SIZE_MAX));
+    mutator_marking_state_.Publish();
+  }
   LeaveAtomicPause();
 }
 
@@ -367,6 +377,10 @@ bool MarkerBase::IncrementalMarkingStep(MarkingConfig::StackState stack_state) {
 }
 
 void MarkerBase::AdvanceMarkingOnAllocation() {
+  StatsCollector::EnabledScope stats_scope(heap().stats_collector(),
+                                           StatsCollector::kIncrementalMark);
+  StatsCollector::EnabledScope nested_scope(heap().stats_collector(),
+                                            StatsCollector::kMarkOnAllocation);
   if (AdvanceMarkingWithLimits()) {
     // Schedule another incremental task for finalizing without a stack.
     ScheduleIncrementalMarkingTask();
@@ -458,7 +472,7 @@ bool MarkerBase::ProcessWorklistsWithDeadline(
               mutator_marking_state_.marking_worklist(),
               [this](const MarkingWorklists::MarkingItem& item) {
                 const HeapObjectHeader& header =
-                    HeapObjectHeader::FromPayload(item.base_object_payload);
+                    HeapObjectHeader::FromObject(item.base_object_payload);
                 DCHECK(!header.IsInConstruction<AccessMode::kNonAtomic>());
                 DCHECK(header.IsMarked<AccessMode::kNonAtomic>());
                 mutator_marking_state_.AccountMarkedBytes(header);
diff --git a/chromium/v8/src/heap/cppgc/marking-state.h b/chromium/v8/src/heap/cppgc/marking-state.h
index 6e08fc3e10e..c4627463338 100644
--- a/chromium/v8/src/heap/cppgc/marking-state.h
+++ b/chromium/v8/src/heap/cppgc/marking-state.h
@@ -174,9 +174,9 @@ MarkingStateBase::MarkingStateBase(HeapBase& heap,
 
 void MarkingStateBase::MarkAndPush(const void* object, TraceDescriptor desc) {
   DCHECK_NOT_NULL(object);
-  MarkAndPush(HeapObjectHeader::FromPayload(
-                  const_cast<void*>(desc.base_object_payload)),
-              desc);
+  MarkAndPush(
+      HeapObjectHeader::FromObject(const_cast<void*>(desc.base_object_payload)),
+      desc);
 }
 
 void MarkingStateBase::MarkAndPush(HeapObjectHeader& header,
@@ -202,7 +202,7 @@ bool MarkingStateBase::MarkNoPush(HeapObjectHeader& header) {
 void MarkingStateBase::MarkAndPush(HeapObjectHeader& header) {
   MarkAndPush(
       header,
-      {header.Payload(),
+      {header.ObjectStart(),
        GlobalGCInfoTable::GCInfoFromIndex(header.GetGCInfoIndex()).trace});
 }
 
@@ -222,7 +222,7 @@ void MarkingStateBase::RegisterWeakReferenceIfNeeded(const void* object,
   // Filter out already marked values. The write barrier for WeakMember
   // ensures that any newly set value after this point is kept alive and does
   // not require the callback.
-  if (HeapObjectHeader::FromPayload(desc.base_object_payload)
+  if (HeapObjectHeader::FromObject(desc.base_object_payload)
           .IsMarked<AccessMode::kAtomic>())
     return;
   RegisterWeakCallback(weak_callback, parameter);
@@ -245,7 +245,7 @@ void MarkingStateBase::ProcessWeakContainer(const void* object,
   DCHECK_NOT_NULL(object);
 
   HeapObjectHeader& header =
-      HeapObjectHeader::FromPayload(const_cast<void*>(object));
+      HeapObjectHeader::FromObject(const_cast<void*>(object));
 
   if (header.IsInConstruction<AccessMode::kAtomic>()) {
     not_fully_constructed_worklist_.Push<AccessMode::kAtomic>(&header);
@@ -255,6 +255,7 @@ void MarkingStateBase::ProcessWeakContainer(const void* object,
   // Only mark the container initially. Its buckets will be processed after
   // marking.
   if (!MarkNoPush(header)) return;
+
   RegisterWeakContainer(header);
 
   // Register final weak processing of the backing store.
@@ -264,7 +265,13 @@ void MarkingStateBase::ProcessWeakContainer(const void* object,
   // the TraceDescriptor will be nullptr. For ephemerons the callback will be
   // non-nullptr so that the container is traced and the ephemeron pairs are
   // processed.
-  if (desc.callback) PushMarked(header, desc);
+  if (desc.callback) {
+    PushMarked(header, desc);
+  } else {
+    // For weak containers, there's no trace callback and no processing loop to
+    // update the marked bytes, hence inline that here.
+    AccountMarkedBytes(header);
+  }
 }
 
 void MarkingStateBase::ProcessEphemeron(const void* key, const void* value,
@@ -273,7 +280,7 @@ void MarkingStateBase::ProcessEphemeron(const void* key, const void* value,
   // Filter out already marked keys. The write barrier for WeakMember
   // ensures that any newly set value after this point is kept alive and does
   // not require the callback.
-  if (HeapObjectHeader::FromPayload(key).IsMarked<AccessMode::kAtomic>()) {
+  if (HeapObjectHeader::FromObject(key).IsMarked<AccessMode::kAtomic>()) {
     if (value_desc.base_object_payload) {
       MarkAndPush(value_desc.base_object_payload, value_desc);
     } else {
@@ -291,7 +298,7 @@ void MarkingStateBase::AccountMarkedBytes(const HeapObjectHeader& header) {
       header.IsLargeObject<AccessMode::kAtomic>()
           ? reinterpret_cast<const LargePage*>(BasePage::FromPayload(&header))
                 ->PayloadSize()
-          : header.GetSize<AccessMode::kAtomic>());
+          : header.AllocatedSize<AccessMode::kAtomic>());
 }
 
 void MarkingStateBase::AccountMarkedBytes(size_t marked_bytes) {
@@ -308,7 +315,7 @@ class MutatorMarkingState : public MarkingStateBase {
     return MutatorMarkingState::MarkingStateBase::MarkNoPush(header);
   }
 
-  inline void PushMarkedWeakContainer(HeapObjectHeader&);
+  inline void ReTraceMarkedWeakContainer(cppgc::Visitor&, HeapObjectHeader&);
 
   inline void DynamicallyMarkAddress(ConstAddress);
 
@@ -343,13 +350,13 @@ class MutatorMarkingState : public MarkingStateBase {
   } recently_retraced_weak_containers_;
 };
 
-void MutatorMarkingState::PushMarkedWeakContainer(HeapObjectHeader& header) {
+void MutatorMarkingState::ReTraceMarkedWeakContainer(cppgc::Visitor& visitor,
+                                                     HeapObjectHeader& header) {
   DCHECK(weak_containers_worklist_.Contains(&header));
   recently_retraced_weak_containers_.Insert(&header);
-  PushMarked(
-      header,
-      {header.Payload(),
-       GlobalGCInfoTable::GCInfoFromIndex(header.GetGCInfoIndex()).trace});
+  // Don't push to the marking worklist to avoid double accounting of marked
+  // bytes as the container is already accounted for.
+  header.Trace(&visitor);
 }
 
 void MutatorMarkingState::DynamicallyMarkAddress(ConstAddress address) {
@@ -359,7 +366,7 @@ void MutatorMarkingState::DynamicallyMarkAddress(ConstAddress address) {
   DCHECK(!header.IsInConstruction());
   if (MarkNoPush(header)) {
     marking_worklist_.Push(
-        {reinterpret_cast<void*>(header.Payload()),
+        {reinterpret_cast<void*>(header.ObjectStart()),
          GlobalGCInfoTable::GCInfoFromIndex(header.GetGCInfoIndex()).trace});
   }
 }
@@ -371,7 +378,7 @@ void MutatorMarkingState::InvokeWeakRootsCallbackIfNeeded(
   // the callback instead of registering it.
 #if DEBUG
   const HeapObjectHeader& header =
-      HeapObjectHeader::FromPayload(desc.base_object_payload);
+      HeapObjectHeader::FromObject(desc.base_object_payload);
   DCHECK_IMPLIES(header.IsInConstruction(), header.IsMarked());
 #endif  // DEBUG
   weak_callback(LivenessBrokerFactory::Create(), parameter);
diff --git a/chromium/v8/src/heap/cppgc/marking-verifier.cc b/chromium/v8/src/heap/cppgc/marking-verifier.cc
index 42e3c4eb3e8..2bbf8878e42 100644
--- a/chromium/v8/src/heap/cppgc/marking-verifier.cc
+++ b/chromium/v8/src/heap/cppgc/marking-verifier.cc
@@ -9,50 +9,81 @@
 #include "src/heap/cppgc/heap-object-header.h"
 #include "src/heap/cppgc/heap.h"
 #include "src/heap/cppgc/marking-visitor.h"
+#include "src/heap/cppgc/object-view.h"
 
 namespace cppgc {
 namespace internal {
 
 MarkingVerifierBase::MarkingVerifierBase(
-    HeapBase& heap, std::unique_ptr<cppgc::Visitor> visitor)
+    HeapBase& heap, VerificationState& verification_state,
+    std::unique_ptr<cppgc::Visitor> visitor)
     : ConservativeTracingVisitor(heap, *heap.page_backend(), *visitor.get()),
+      verification_state_(verification_state),
       visitor_(std::move(visitor)) {}
 
-void MarkingVerifierBase::Run(Heap::Config::StackState stack_state) {
+void MarkingVerifierBase::Run(Heap::Config::StackState stack_state,
+                              uintptr_t stack_end,
+                              size_t expected_marked_bytes) {
   Traverse(&heap_.raw_heap());
   if (stack_state == Heap::Config::StackState::kMayContainHeapPointers) {
     in_construction_objects_ = &in_construction_objects_stack_;
-    heap_.stack()->IteratePointers(this);
-    CHECK_EQ(in_construction_objects_stack_, in_construction_objects_heap_);
+    heap_.stack()->IteratePointersUnsafe(this, stack_end);
+    // The objects found through the unsafe iteration are only a subset of the
+    // regular iteration as they miss objects held alive only from callee-saved
+    // registers that are never pushed on the stack and SafeStack.
+    CHECK_LE(in_construction_objects_stack_.size(),
+             in_construction_objects_heap_.size());
+    for (auto* header : in_construction_objects_stack_) {
+      CHECK_NE(in_construction_objects_heap_.end(),
+               in_construction_objects_heap_.find(header));
+    }
   }
+#ifdef CPPGC_VERIFY_LIVE_BYTES
+  CHECK_EQ(expected_marked_bytes, found_marked_bytes_);
+#endif  // CPPGC_VERIFY_LIVE_BYTES
 }
 
 void VerificationState::VerifyMarked(const void* base_object_payload) const {
   const HeapObjectHeader& child_header =
-      HeapObjectHeader::FromPayload(base_object_payload);
+      HeapObjectHeader::FromObject(base_object_payload);
 
   if (!child_header.IsMarked()) {
     FATAL(
         "MarkingVerifier: Encountered unmarked object.\n"
         "#\n"
         "# Hint:\n"
-        "#   %s\n"
-        "#     \\-> %s",
-        parent_->GetName().value, child_header.GetName().value);
+        "#   %s (%p)\n"
+        "#     \\-> %s (%p)",
+        parent_ ? parent_->GetName().value : "Stack",
+        parent_ ? parent_->ObjectStart() : nullptr,
+        child_header.GetName().value, child_header.ObjectStart());
   }
 }
 
 void MarkingVerifierBase::VisitInConstructionConservatively(
     HeapObjectHeader& header, TraceConservativelyCallback callback) {
-  CHECK(header.IsMarked());
   if (in_construction_objects_->find(&header) !=
       in_construction_objects_->end())
     return;
   in_construction_objects_->insert(&header);
+
+  // Stack case: Parent is stack and this is merely ensuring that the object
+  // itself is marked. If the object is marked, then it is being processed by
+  // the on-heap phase.
+  if (verification_state_.IsParentOnStack()) {
+    verification_state_.VerifyMarked(header.ObjectStart());
+    return;
+  }
+
+  // Heap case: Dispatching parent object that must be marked (pre-condition).
+  CHECK(header.IsMarked());
   callback(this, header);
 }
 
 void MarkingVerifierBase::VisitPointer(const void* address) {
+  // Entry point for stack walk. The conservative visitor dispatches as follows:
+  // - Fully constructed objects: Visit()
+  // - Objects in construction: VisitInConstructionConservatively()
   TraceConservativelyIfNeeded(address);
 }
 
@@ -62,7 +93,7 @@ bool MarkingVerifierBase::VisitHeapObjectHeader(HeapObjectHeader* header) {
 
   DCHECK(!header->IsFree());
 
-  SetCurrentParent(header);
+  verification_state_.SetCurrentParent(header);
 
   if (!header->IsInConstruction()) {
     header->Trace(visitor_.get());
@@ -71,6 +102,10 @@ bool MarkingVerifierBase::VisitHeapObjectHeader(HeapObjectHeader* header) {
     TraceConservativelyIfNeeded(*header);
   }
 
+  found_marked_bytes_ += ObjectView(*header).Size() + sizeof(HeapObjectHeader);
+
+  verification_state_.SetCurrentParent(nullptr);
+
   return true;
 }
 
@@ -112,12 +147,8 @@ class VerificationVisitor final : public cppgc::Visitor {
 }  // namespace
 
 MarkingVerifier::MarkingVerifier(HeapBase& heap_base)
-    : MarkingVerifierBase(heap_base,
+    : MarkingVerifierBase(heap_base, state_,
                           std::make_unique<VerificationVisitor>(state_)) {}
 
-void MarkingVerifier::SetCurrentParent(const HeapObjectHeader* parent) {
-  state_.SetCurrentParent(parent);
-}
-
 }  // namespace internal
 }  // namespace cppgc
diff --git a/chromium/v8/src/heap/cppgc/marking-verifier.h b/chromium/v8/src/heap/cppgc/marking-verifier.h
index eeced684497..95475f5191a 100644
--- a/chromium/v8/src/heap/cppgc/marking-verifier.h
+++ b/chromium/v8/src/heap/cppgc/marking-verifier.h
@@ -21,6 +21,9 @@ class VerificationState {
   void VerifyMarked(const void*) const;
   void SetCurrentParent(const HeapObjectHeader* header) { parent_ = header; }
 
+  // No parent means parent was on stack.
+  bool IsParentOnStack() const { return !parent_; }
+
  private:
   const HeapObjectHeader* parent_ = nullptr;
 };
@@ -37,12 +40,11 @@ class V8_EXPORT_PRIVATE MarkingVerifierBase
   MarkingVerifierBase(const MarkingVerifierBase&) = delete;
   MarkingVerifierBase& operator=(const MarkingVerifierBase&) = delete;
 
-  void Run(Heap::Config::StackState);
+  void Run(Heap::Config::StackState, uintptr_t, size_t);
 
  protected:
-  MarkingVerifierBase(HeapBase&, std::unique_ptr<cppgc::Visitor>);
-
-  virtual void SetCurrentParent(const HeapObjectHeader*) = 0;
+  MarkingVerifierBase(HeapBase&, VerificationState&,
+                      std::unique_ptr<cppgc::Visitor>);
 
  private:
   void VisitInConstructionConservatively(HeapObjectHeader&,
@@ -51,12 +53,14 @@ class V8_EXPORT_PRIVATE MarkingVerifierBase
 
   bool VisitHeapObjectHeader(HeapObjectHeader*);
 
+  VerificationState& verification_state_;
   std::unique_ptr<cppgc::Visitor> visitor_;
 
   std::unordered_set<const HeapObjectHeader*> in_construction_objects_heap_;
   std::unordered_set<const HeapObjectHeader*> in_construction_objects_stack_;
   std::unordered_set<const HeapObjectHeader*>* in_construction_objects_ =
       &in_construction_objects_heap_;
+  size_t found_marked_bytes_ = 0;
 };
 
 class V8_EXPORT_PRIVATE MarkingVerifier final : public MarkingVerifierBase {
@@ -64,8 +68,6 @@ class V8_EXPORT_PRIVATE MarkingVerifier final : public MarkingVerifierBase {
   explicit MarkingVerifier(HeapBase&);
   ~MarkingVerifier() final = default;
 
-  void SetCurrentParent(const HeapObjectHeader*) final;
-
  private:
   VerificationState state_;
 };
diff --git a/chromium/v8/src/heap/cppgc/marking-visitor.cc b/chromium/v8/src/heap/cppgc/marking-visitor.cc
index fb51ccc303e..a740d33a841 100644
--- a/chromium/v8/src/heap/cppgc/marking-visitor.cc
+++ b/chromium/v8/src/heap/cppgc/marking-visitor.cc
@@ -56,7 +56,7 @@ void ConservativeMarkingVisitor::VisitFullyConstructedConservatively(
     HeapObjectHeader& header) {
   if (header.IsMarked()) {
     if (marking_state_.IsMarkedWeakContainer(header))
-      marking_state_.PushMarkedWeakContainer(header);
+      marking_state_.ReTraceMarkedWeakContainer(visitor_, header);
     return;
   }
   ConservativeTracingVisitor::VisitFullyConstructedConservatively(header);
diff --git a/chromium/v8/src/heap/cppgc/memory.cc b/chromium/v8/src/heap/cppgc/memory.cc
new file mode 100644
index 00000000000..aa3baeaa8a0
--- /dev/null
+++ b/chromium/v8/src/heap/cppgc/memory.cc
@@ -0,0 +1,22 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/heap/cppgc/memory.h"
+
+#include <cstddef>
+
+#include "src/heap/cppgc/globals.h"
+
+namespace cppgc {
+namespace internal {
+
+void NoSanitizeMemset(void* address, char c, size_t bytes) {
+  volatile Address base = reinterpret_cast<Address>(address);
+  for (size_t i = 0; i < bytes; ++i) {
+    base[i] = c;
+  }
+}
+
+}  // namespace internal
+}  // namespace cppgc
diff --git a/chromium/v8/src/heap/cppgc/memory.h b/chromium/v8/src/heap/cppgc/memory.h
new file mode 100644
index 00000000000..d31af33ee3f
--- /dev/null
+++ b/chromium/v8/src/heap/cppgc/memory.h
@@ -0,0 +1,76 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_HEAP_CPPGC_MEMORY_H_
+#define V8_HEAP_CPPGC_MEMORY_H_
+
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+
+#include "src/base/macros.h"
+#include "src/base/sanitizer/asan.h"
+#include "src/base/sanitizer/msan.h"
+
+namespace cppgc {
+namespace internal {
+
+V8_NOINLINE DISABLE_ASAN void NoSanitizeMemset(void* address, char c,
+                                               size_t bytes);
+
+inline void ZapMemory(void* address, size_t size) {
+  // The lowest bit of the zapped value should be 0 so that zapped object are
+  // never viewed as fully constructed objects.
+  static constexpr uint8_t kZappedValue = 0xdc;
+  memset(address, kZappedValue, size);
+}
+
+// Together `SetMemoryAccessible()` and `SetMemoryInaccessible()` form the
+// memory access model for allocation and free.
+V8_INLINE void SetMemoryAccessible(void* address, size_t size) {
+#if defined(V8_USE_MEMORY_SANITIZER)
+
+  MSAN_MEMORY_IS_INITIALIZED(address, size);
+
+#elif defined(V8_USE_ADDRESS_SANITIZER)
+
+  ASAN_UNPOISON_MEMORY_REGION(address, size);
+
+#elif DEBUG
+
+  memset(address, 0, size);
+
+#else  // Release builds.
+
+  // Nothing to be done for release builds.
+
+#endif  // Release builds.
+}
+
+V8_INLINE void SetMemoryInaccessible(void* address, size_t size) {
+#if defined(V8_USE_MEMORY_SANITIZER)
+
+  memset(address, 0, size);
+  MSAN_ALLOCATED_UNINITIALIZED_MEMORY(address, size);
+
+#elif defined(V8_USE_ADDRESS_SANITIZER)
+
+  NoSanitizeMemset(address, 0, size);
+  ASAN_POISON_MEMORY_REGION(address, size);
+
+#elif DEBUG
+
+  ::cppgc::internal::ZapMemory(address, size);
+
+#else  // Release builds.
+
+  memset(address, 0, size);
+
+#endif  // Release builds.
+}
+
+}  // namespace internal
+}  // namespace cppgc
+
+#endif  // V8_HEAP_CPPGC_MEMORY_H_
diff --git a/chromium/v8/src/heap/cppgc/metric-recorder.h b/chromium/v8/src/heap/cppgc/metric-recorder.h
index 6e9d4d0787c..6118627d01d 100644
--- a/chromium/v8/src/heap/cppgc/metric-recorder.h
+++ b/chromium/v8/src/heap/cppgc/metric-recorder.h
@@ -14,7 +14,7 @@ class StatsCollector;
 
 /**
  * Base class used for reporting GC statistics histograms. Embedders interested
- * in collecting histgorams should implement the virtual AddMainThreadEvent
+ * in collecting histograms should implement the virtual AddMainThreadEvent
  * methods below and pass an instance of the implementation during Heap
  * creation.
  */
diff --git a/chromium/v8/src/heap/cppgc/object-allocator.cc b/chromium/v8/src/heap/cppgc/object-allocator.cc
index 366900b0f92..1197356c29d 100644
--- a/chromium/v8/src/heap/cppgc/object-allocator.cc
+++ b/chromium/v8/src/heap/cppgc/object-allocator.cc
@@ -95,7 +95,7 @@ void* AllocateLargeObject(PageBackend* page_backend, LargePageSpace* space,
   stats_collector->NotifyAllocation(size);
   MarkRangeAsYoung(page, page->PayloadStart(), page->PayloadEnd());
 
-  return header->Payload();
+  return header->ObjectStart();
 }
 
 }  // namespace
diff --git a/chromium/v8/src/heap/cppgc/object-allocator.h b/chromium/v8/src/heap/cppgc/object-allocator.h
index 56faef1c833..dd99d83ba56 100644
--- a/chromium/v8/src/heap/cppgc/object-allocator.h
+++ b/chromium/v8/src/heap/cppgc/object-allocator.h
@@ -12,9 +12,9 @@
 #include "src/heap/cppgc/heap-object-header.h"
 #include "src/heap/cppgc/heap-page.h"
 #include "src/heap/cppgc/heap-space.h"
+#include "src/heap/cppgc/memory.h"
 #include "src/heap/cppgc/object-start-bitmap.h"
 #include "src/heap/cppgc/raw-heap.h"
-#include "src/heap/cppgc/sanitizers.h"
 
 namespace cppgc {
 
@@ -111,10 +111,10 @@ void* ObjectAllocator::AllocateObjectOnSpace(NormalPageSpace* space,
 #if !defined(V8_USE_MEMORY_SANITIZER) && !defined(V8_USE_ADDRESS_SANITIZER) && \
     DEBUG
   // For debug builds, unzap only the payload.
-  SET_MEMORY_ACCESSIBLE(static_cast<char*>(raw) + sizeof(HeapObjectHeader),
-                        size - sizeof(HeapObjectHeader));
+  SetMemoryAccessible(static_cast<char*>(raw) + sizeof(HeapObjectHeader),
+                      size - sizeof(HeapObjectHeader));
 #else
-  SET_MEMORY_ACCESSIBLE(raw, size);
+  SetMemoryAccessible(raw, size);
 #endif
   auto* header = new (raw) HeapObjectHeader(size, gcinfo);
 
@@ -123,7 +123,7 @@ void* ObjectAllocator::AllocateObjectOnSpace(NormalPageSpace* space,
       ->object_start_bitmap()
       .SetBit<AccessMode::kAtomic>(reinterpret_cast<ConstAddress>(header));
 
-  return header->Payload();
+  return header->ObjectStart();
 }
 
 }  // namespace internal
diff --git a/chromium/v8/src/heap/cppgc/object-poisoner.h b/chromium/v8/src/heap/cppgc/object-poisoner.h
index fd2462d6694..632dea9b9d7 100644
--- a/chromium/v8/src/heap/cppgc/object-poisoner.h
+++ b/chromium/v8/src/heap/cppgc/object-poisoner.h
@@ -5,10 +5,10 @@
 #ifndef V8_HEAP_CPPGC_OBJECT_POISONER_H_
 #define V8_HEAP_CPPGC_OBJECT_POISONER_H_
 
+#include "src/base/sanitizer/asan.h"
 #include "src/heap/cppgc/heap-object-header.h"
 #include "src/heap/cppgc/heap-page.h"
 #include "src/heap/cppgc/heap-visitor.h"
-#include "src/heap/cppgc/sanitizers.h"
 
 namespace cppgc {
 namespace internal {
@@ -27,7 +27,7 @@ class UnmarkedObjectsPoisoner : public HeapVisitor<UnmarkedObjectsPoisoner> {
         header->IsLargeObject()
             ? LargePage::From(BasePage::FromPayload(header))->ObjectSize()
             : header->ObjectSize();
-    ASAN_POISON_MEMORY_REGION(header->Payload(), size);
+    ASAN_POISON_MEMORY_REGION(header->ObjectStart(), size);
     return true;
   }
 };
diff --git a/chromium/v8/src/heap/cppgc/object-size-trait.cc b/chromium/v8/src/heap/cppgc/object-size-trait.cc
index 11c50b3c4d1..7b82239a610 100644
--- a/chromium/v8/src/heap/cppgc/object-size-trait.cc
+++ b/chromium/v8/src/heap/cppgc/object-size-trait.cc
@@ -6,6 +6,7 @@
 
 #include "src/heap/cppgc/heap-object-header.h"
 #include "src/heap/cppgc/heap-page.h"
+#include "src/heap/cppgc/object-view.h"
 
 namespace cppgc {
 namespace internal {
@@ -13,11 +14,7 @@ namespace internal {
 // static
 size_t BaseObjectSizeTrait::GetObjectSizeForGarbageCollected(
     const void* object) {
-  const auto& header = HeapObjectHeader::FromPayload(object);
-  return header.IsLargeObject()
-             ? static_cast<const LargePage*>(BasePage::FromPayload(&header))
-                   ->ObjectSize()
-             : header.ObjectSize();
+  return ObjectView(HeapObjectHeader::FromObject(object)).Size();
 }
 
 // static
diff --git a/chromium/v8/src/heap/cppgc/object-view.h b/chromium/v8/src/heap/cppgc/object-view.h
new file mode 100644
index 00000000000..e83145cc319
--- /dev/null
+++ b/chromium/v8/src/heap/cppgc/object-view.h
@@ -0,0 +1,54 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_HEAP_CPPGC_OBJECT_VIEW_H_
+#define V8_HEAP_CPPGC_OBJECT_VIEW_H_
+
+#include "include/v8config.h"
+#include "src/heap/cppgc/heap-object-header.h"
+#include "src/heap/cppgc/heap-page.h"
+
+namespace cppgc {
+namespace internal {
+
+// ObjectView allows accessing a header within the bounds of the actual object.
+// It is not exposed externally and does not keep the underlying object alive.
+class ObjectView final {
+ public:
+  V8_INLINE explicit ObjectView(const HeapObjectHeader& header);
+
+  V8_INLINE Address Start() const;
+  V8_INLINE ConstAddress End() const;
+  V8_INLINE size_t Size() const;
+
+ private:
+  const HeapObjectHeader& header_;
+  const BasePage* base_page_;
+  const bool is_large_object_;
+};
+
+ObjectView::ObjectView(const HeapObjectHeader& header)
+    : header_(header),
+      base_page_(
+          BasePage::FromPayload(const_cast<HeapObjectHeader*>(&header_))),
+      is_large_object_(header_.IsLargeObject()) {
+  DCHECK_EQ(Start() + Size(), End());
+}
+
+Address ObjectView::Start() const { return header_.ObjectStart(); }
+
+ConstAddress ObjectView::End() const {
+  return is_large_object_ ? LargePage::From(base_page_)->PayloadEnd()
+                          : header_.ObjectEnd();
+}
+
+size_t ObjectView::Size() const {
+  return is_large_object_ ? LargePage::From(base_page_)->ObjectSize()
+                          : header_.ObjectSize();
+}
+
+}  // namespace internal
+}  // namespace cppgc
+
+#endif  // V8_HEAP_CPPGC_OBJECT_VIEW_H_
diff --git a/chromium/v8/src/heap/cppgc/page-memory.cc b/chromium/v8/src/heap/cppgc/page-memory.cc
index 76b9458517e..49b44aff91c 100644
--- a/chromium/v8/src/heap/cppgc/page-memory.cc
+++ b/chromium/v8/src/heap/cppgc/page-memory.cc
@@ -5,7 +5,7 @@
 #include "src/heap/cppgc/page-memory.h"
 
 #include "src/base/macros.h"
-#include "src/heap/cppgc/sanitizers.h"
+#include "src/base/sanitizer/asan.h"
 
 namespace cppgc {
 namespace internal {
diff --git a/chromium/v8/src/heap/cppgc/pointer-policies.cc b/chromium/v8/src/heap/cppgc/pointer-policies.cc
index fdc435af17c..23ad552c7aa 100644
--- a/chromium/v8/src/heap/cppgc/pointer-policies.cc
+++ b/chromium/v8/src/heap/cppgc/pointer-policies.cc
@@ -4,21 +4,70 @@
 
 #include "include/cppgc/internal/pointer-policies.h"
 
+#include "include/cppgc/internal/caged-heap-local-data.h"
 #include "include/cppgc/internal/persistent-node.h"
+#include "src/base/logging.h"
 #include "src/base/macros.h"
+#include "src/base/platform/platform.h"
+#include "src/heap/cppgc/heap-object-header.h"
 #include "src/heap/cppgc/heap-page.h"
 #include "src/heap/cppgc/heap.h"
+#include "src/heap/cppgc/page-memory.h"
+#include "src/heap/cppgc/process-heap.h"
 
 namespace cppgc {
 namespace internal {
 
-EnabledCheckingPolicy::EnabledCheckingPolicy() {
-  USE(impl_);
-  // TODO(chromium:1056170): Save creating heap state.
+namespace {
+
+#if defined(DEBUG)
+bool IsOnStack(const void* address) {
+  return v8::base::Stack::GetCurrentStackPosition() <= address &&
+         address < v8::base::Stack::GetStackStart();
 }
+#endif  // defined(DEBUG)
+
+}  // namespace
+
+void EnabledCheckingPolicy::CheckPointerImpl(const void* ptr,
+                                             bool points_to_payload) {
+  // `ptr` must not reside on stack.
+  DCHECK(!IsOnStack(ptr));
+  auto* base_page = BasePage::FromPayload(ptr);
+  // Large objects do not support mixins. This also means that `base_page` is
+  // valid for large objects.
+  DCHECK_IMPLIES(base_page->is_large(), points_to_payload);
+
+  // References cannot change their heap association which means that state is
+  // immutable once it is set.
+  if (!heap_) {
+    heap_ = base_page->heap();
+    if (!heap_->page_backend()->Lookup(reinterpret_cast<Address>(this))) {
+      // If `this` is not contained within the heap of `ptr`, we must deal with
+      // an on-stack or off-heap reference. For both cases there should be no
+      // heap registered.
+      CHECK(!HeapRegistry::TryFromManagedPointer(this));
+    }
+  }
+
+  // Member references should never mix heaps.
+  DCHECK_EQ(heap_, base_page->heap());
+
+  // Header checks.
+  const HeapObjectHeader* header = nullptr;
+  if (points_to_payload) {
+    header = &HeapObjectHeader::FromObject(ptr);
+  } else if (!heap_->sweeper().IsSweepingInProgress()) {
+    // Mixin case.
+    header = &base_page->ObjectHeaderFromInnerAddress(ptr);
+    DCHECK_LE(header->ObjectStart(), ptr);
+    DCHECK_GT(header->ObjectEnd(), ptr);
+  }
+  if (header) {
+    DCHECK(!header->IsFree());
+  }
 
-void EnabledCheckingPolicy::CheckPointer(const void* ptr) {
-  // TODO(chromium:1056170): Provide implementation.
+  // TODO(v8:11749): Check mark bits when during pre-finalizer phase.
 }
 
 PersistentRegion& StrongPersistentPolicy::GetPersistentRegion(
diff --git a/chromium/v8/src/heap/cppgc/process-heap-statistics.h b/chromium/v8/src/heap/cppgc/process-heap-statistics.h
index 2d7bfa117f8..da7683b616a 100644
--- a/chromium/v8/src/heap/cppgc/process-heap-statistics.h
+++ b/chromium/v8/src/heap/cppgc/process-heap-statistics.h
@@ -15,7 +15,7 @@ class ProcessHeapStatisticsUpdater {
  public:
   // Allocation observer implementation for heaps should register to contribute
   // to ProcessHeapStatistics. The heap is responsible for allocating and
-  // registering the obsrever impl with its stats collector.
+  // registering the observer impl with its stats collector.
   class AllocationObserverImpl final
       : public StatsCollector::AllocationObserver {
    public:
diff --git a/chromium/v8/src/heap/cppgc/process-heap.cc b/chromium/v8/src/heap/cppgc/process-heap.cc
index e084ea1264b..6f8bb05c6cf 100644
--- a/chromium/v8/src/heap/cppgc/process-heap.cc
+++ b/chromium/v8/src/heap/cppgc/process-heap.cc
@@ -4,10 +4,66 @@
 
 #include "src/heap/cppgc/process-heap.h"
 
+#include <algorithm>
+#include <vector>
+
+#include "src/base/lazy-instance.h"
+#include "src/base/platform/mutex.h"
+#include "src/heap/cppgc/heap-base.h"
+#include "src/heap/cppgc/page-memory.h"
+
 namespace cppgc {
 namespace internal {
 
 v8::base::LazyMutex g_process_mutex = LAZY_MUTEX_INITIALIZER;
 
+namespace {
+
+v8::base::LazyMutex g_heap_registry_mutex = LAZY_MUTEX_INITIALIZER;
+
+HeapRegistry::Storage& GetHeapRegistryStorage() {
+  static v8::base::LazyInstance<HeapRegistry::Storage>::type heap_registry =
+      LAZY_INSTANCE_INITIALIZER;
+  return *heap_registry.Pointer();
+}
+
+}  // namespace
+
+// static
+void HeapRegistry::RegisterHeap(HeapBase& heap) {
+  v8::base::MutexGuard guard(g_heap_registry_mutex.Pointer());
+
+  auto& storage = GetHeapRegistryStorage();
+  DCHECK_EQ(storage.end(), std::find(storage.begin(), storage.end(), &heap));
+  storage.push_back(&heap);
+}
+
+// static
+void HeapRegistry::UnregisterHeap(HeapBase& heap) {
+  v8::base::MutexGuard guard(g_heap_registry_mutex.Pointer());
+
+  auto& storage = GetHeapRegistryStorage();
+  const auto pos = std::find(storage.begin(), storage.end(), &heap);
+  DCHECK_NE(storage.end(), pos);
+  storage.erase(pos);
+}
+
+// static
+HeapBase* HeapRegistry::TryFromManagedPointer(const void* needle) {
+  v8::base::MutexGuard guard(g_heap_registry_mutex.Pointer());
+
+  for (auto* heap : GetHeapRegistryStorage()) {
+    const auto address =
+        heap->page_backend()->Lookup(reinterpret_cast<ConstAddress>(needle));
+    if (address) return heap;
+  }
+  return nullptr;
+}
+
+// static
+const HeapRegistry::Storage& HeapRegistry::GetRegisteredHeapsForTesting() {
+  return GetHeapRegistryStorage();
+}
+
 }  // namespace internal
 }  // namespace cppgc
diff --git a/chromium/v8/src/heap/cppgc/process-heap.h b/chromium/v8/src/heap/cppgc/process-heap.h
index 8afc7c88eb5..c581bad29c5 100644
--- a/chromium/v8/src/heap/cppgc/process-heap.h
+++ b/chromium/v8/src/heap/cppgc/process-heap.h
@@ -5,13 +5,48 @@
 #ifndef V8_HEAP_CPPGC_PROCESS_HEAP_H_
 #define V8_HEAP_CPPGC_PROCESS_HEAP_H_
 
+#include <vector>
+
+#include "src/base/macros.h"
 #include "src/base/platform/mutex.h"
 
 namespace cppgc {
 namespace internal {
 
+class HeapBase;
+
 extern v8::base::LazyMutex g_process_mutex;
 
+class V8_EXPORT_PRIVATE HeapRegistry final {
+ public:
+  using Storage = std::vector<HeapBase*>;
+
+  class Subscription final {
+   public:
+    inline explicit Subscription(HeapBase&);
+    inline ~Subscription();
+
+   private:
+    HeapBase& heap_;
+  };
+
+  static HeapBase* TryFromManagedPointer(const void* needle);
+
+  static const Storage& GetRegisteredHeapsForTesting();
+
+ private:
+  static void RegisterHeap(HeapBase&);
+  static void UnregisterHeap(HeapBase&);
+};
+
+HeapRegistry::Subscription::Subscription(HeapBase& heap) : heap_(heap) {
+  HeapRegistry::RegisterHeap(heap_);
+}
+
+HeapRegistry::Subscription::~Subscription() {
+  HeapRegistry::UnregisterHeap(heap_);
+}
+
 }  // namespace internal
 }  // namespace cppgc
 
diff --git a/chromium/v8/src/heap/cppgc/sanitizers.h b/chromium/v8/src/heap/cppgc/sanitizers.h
deleted file mode 100644
index c3a8ff684d7..00000000000
--- a/chromium/v8/src/heap/cppgc/sanitizers.h
+++ /dev/null
@@ -1,82 +0,0 @@
-// Copyright 2020 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef V8_HEAP_CPPGC_SANITIZERS_H_
-#define V8_HEAP_CPPGC_SANITIZERS_H_
-
-#include <stdint.h>
-#include <string.h>
-
-#include "src/base/macros.h"
-
-//
-// TODO(chromium:1056170): Find a place in base for sanitizer support.
-//
-
-#ifdef V8_USE_ADDRESS_SANITIZER
-
-#include <sanitizer/asan_interface.h>
-
-#define NO_SANITIZE_ADDRESS __attribute__((no_sanitize_address))
-#if !defined(ASAN_POISON_MEMORY_REGION) || !defined(ASAN_UNPOISON_MEMORY_REGION)
-#error "ASAN_POISON_MEMORY_REGION must be defined"
-#endif
-
-#else  // !V8_USE_ADDRESS_SANITIZER
-
-#define NO_SANITIZE_ADDRESS
-#define ASAN_POISON_MEMORY_REGION(addr, size) ((void)(addr), (void)(size))
-#define ASAN_UNPOISON_MEMORY_REGION(addr, size) ((void)(addr), (void)(size))
-
-#endif  // V8_USE_ADDRESS_SANITIZER
-
-#ifdef V8_USE_MEMORY_SANITIZER
-
-#include <sanitizer/msan_interface.h>
-
-#define MSAN_POISON(addr, size) __msan_allocated_memory(addr, size)
-#define MSAN_UNPOISON(addr, size) __msan_unpoison(addr, size)
-
-#else  // !V8_USE_MEMORY_SANITIZER
-
-#define MSAN_POISON(addr, size) ((void)(addr), (void)(size))
-#define MSAN_UNPOISON(addr, size) ((void)(addr), (void)(size))
-
-#endif  // V8_USE_MEMORY_SANITIZER
-
-// API for newly allocated or reclaimed memory.
-#if defined(V8_USE_MEMORY_SANITIZER)
-#define SET_MEMORY_ACCESSIBLE(address, size) MSAN_UNPOISON(address, size);
-#define SET_MEMORY_INACCESSIBLE(address, size) \
-  memset((address), 0, (size));                \
-  MSAN_POISON((address), (size))
-#elif defined(V8_USE_ADDRESS_SANITIZER)
-#define SET_MEMORY_ACCESSIBLE(address, size) \
-  ASAN_UNPOISON_MEMORY_REGION(address, size);
-#define SET_MEMORY_INACCESSIBLE(address, size) \
-  memset((address), 0, (size));                \
-  ASAN_POISON_MEMORY_REGION(address, size)
-#elif DEBUG
-#define SET_MEMORY_ACCESSIBLE(address, size) memset((address), 0, (size))
-#define SET_MEMORY_INACCESSIBLE(address, size) \
-  ::cppgc::internal::ZapMemory((address), (size));
-#else
-#define SET_MEMORY_ACCESSIBLE(address, size) ((void)(address), (void)(size))
-#define SET_MEMORY_INACCESSIBLE(address, size) memset((address), 0, (size))
-#endif
-
-namespace cppgc {
-namespace internal {
-
-inline void ZapMemory(void* address, size_t size) {
-  // The lowest bit of the zapped value should be 0 so that zapped object
-  // are never viewed as fully constructed objects.
-  static constexpr uint8_t kZappedValue = 0xdc;
-  memset(address, kZappedValue, size);
-}
-
-}  // namespace internal
-}  // namespace cppgc
-
-#endif  // V8_HEAP_CPPGC_SANITIZERS_H_
diff --git a/chromium/v8/src/heap/cppgc/stats-collector.h b/chromium/v8/src/heap/cppgc/stats-collector.h
index 2a8583c7304..4709f227035 100644
--- a/chromium/v8/src/heap/cppgc/stats-collector.h
+++ b/chromium/v8/src/heap/cppgc/stats-collector.h
@@ -39,6 +39,7 @@ namespace internal {
   V(MarkTransitiveClosure)                  \
   V(MarkTransitiveClosureWithDeadline)      \
   V(MarkFlushEphemerons)                    \
+  V(MarkOnAllocation)                       \
   V(MarkProcessBailOutObjects)              \
   V(MarkProcessMarkingWorklist)             \
   V(MarkProcessWriteBarrierWorklist)        \
@@ -52,6 +53,7 @@ namespace internal {
   V(MarkVisitRememberedSets)                \
   V(SweepInvokePreFinalizers)               \
   V(SweepIdleStep)                          \
+  V(SweepInTask)                            \
   V(SweepOnAllocation)                      \
   V(SweepFinalize)
 
@@ -256,7 +258,7 @@ class V8_EXPORT_PRIVATE StatsCollector final {
 
   void NotifyAllocation(size_t);
   void NotifyExplicitFree(size_t);
-  // Safepoints should only be invoked when garabge collections are possible.
+  // Safepoints should only be invoked when garbage collections are possible.
   // This is necessary as increments and decrements are reported as close to
   // their actual allocation/reclamation as possible.
   void NotifySafePointForConservativeCollection();
diff --git a/chromium/v8/src/heap/cppgc/sweeper.cc b/chromium/v8/src/heap/cppgc/sweeper.cc
index 937a52afc59..3e740f7924a 100644
--- a/chromium/v8/src/heap/cppgc/sweeper.cc
+++ b/chromium/v8/src/heap/cppgc/sweeper.cc
@@ -18,10 +18,10 @@
 #include "src/heap/cppgc/heap-page.h"
 #include "src/heap/cppgc/heap-space.h"
 #include "src/heap/cppgc/heap-visitor.h"
+#include "src/heap/cppgc/memory.h"
 #include "src/heap/cppgc/object-poisoner.h"
 #include "src/heap/cppgc/object-start-bitmap.h"
 #include "src/heap/cppgc/raw-heap.h"
-#include "src/heap/cppgc/sanitizers.h"
 #include "src/heap/cppgc/stats-collector.h"
 #include "src/heap/cppgc/task-handle.h"
 
@@ -133,7 +133,7 @@ class InlinedFinalizationBuilder final {
 
   void AddFinalizer(HeapObjectHeader* header, size_t size) {
     header->Finalize();
-    SET_MEMORY_INACCESSIBLE(header, size);
+    SetMemoryInaccessible(header, size);
   }
 
   void AddFreeListEntry(Address start, size_t size) {
@@ -161,10 +161,7 @@ class DeferredFinalizationBuilder final {
       result_.unfinalized_objects.push_back({header});
       found_finalizer_ = true;
     } else {
-      // Unmarked memory may have been poisoned. In the non-concurrent case this
-      // is taken care of by finalizing a header.
-      ASAN_UNPOISON_MEMORY_REGION(header, size);
-      SET_MEMORY_INACCESSIBLE(header, size);
+      SetMemoryInaccessible(header, size);
     }
   }
 
@@ -197,15 +194,16 @@ typename FinalizationBuilder::ResultType SweepNormalPage(NormalPage* page) {
   bitmap.Clear();
 
   size_t largest_new_free_list_entry = 0;
+  size_t live_bytes = 0;
 
   Address start_of_gap = page->PayloadStart();
   for (Address begin = page->PayloadStart(), end = page->PayloadEnd();
        begin != end;) {
     HeapObjectHeader* header = reinterpret_cast<HeapObjectHeader*>(begin);
-    const size_t size = header->GetSize();
+    const size_t size = header->AllocatedSize();
     // Check if this is a free list entry.
     if (header->IsFree<kAtomicAccess>()) {
-      SET_MEMORY_INACCESSIBLE(header, std::min(kFreeListEntrySize, size));
+      SetMemoryInaccessible(header, std::min(kFreeListEntrySize, size));
       begin += size;
       continue;
     }
@@ -229,6 +227,7 @@ typename FinalizationBuilder::ResultType SweepNormalPage(NormalPage* page) {
     bitmap.SetBit(begin);
     begin += size;
     start_of_gap = begin;
+    live_bytes += size;
   }
 
   if (start_of_gap != page->PayloadStart() &&
@@ -237,6 +236,7 @@ typename FinalizationBuilder::ResultType SweepNormalPage(NormalPage* page) {
         start_of_gap, static_cast<size_t>(page->PayloadEnd() - start_of_gap));
     bitmap.SetBit(start_of_gap);
   }
+  page->SetAllocatedBytesAtLastGC(live_bytes);
 
   const bool is_empty = (start_of_gap == page->PayloadStart());
   return builder.GetResult(is_empty, largest_new_free_list_entry);
@@ -290,9 +290,9 @@ class SweepFinalizer final {
 
     // Call finalizers.
     for (HeapObjectHeader* object : page_state->unfinalized_objects) {
-      const size_t size = object->GetSize();
+      const size_t size = object->AllocatedSize();
       object->Finalize();
-      SET_MEMORY_INACCESSIBLE(object, size);
+      SetMemoryInaccessible(object, size);
     }
 
     // Unmap page if empty.
@@ -665,6 +665,33 @@ class Sweeper::SweeperImpl final {
 
   bool IsSweepingInProgress() const { return is_in_progress_; }
 
+  bool PerformSweepOnMutatorThread(double deadline_in_seconds,
+                                   StatsCollector::ScopeId internal_scope_id) {
+    if (!is_in_progress_) return true;
+
+    MutatorThreadSweepingScope sweeping_in_progresss(*this);
+
+    bool sweep_complete;
+    {
+      StatsCollector::EnabledScope stats_scope(
+          stats_collector_, StatsCollector::kIncrementalSweep);
+
+      MutatorThreadSweeper sweeper(&space_states_, platform_);
+      {
+        StatsCollector::EnabledScope stats_scope(
+            stats_collector_, internal_scope_id, "deltaInSeconds",
+            deadline_in_seconds - platform_->MonotonicallyIncreasingTime());
+
+        sweep_complete = sweeper.SweepWithDeadline(deadline_in_seconds);
+      }
+      if (sweep_complete) {
+        FinalizeSweep();
+      }
+    }
+    if (sweep_complete) NotifyDone();
+    return sweep_complete;
+  }
+
  private:
   class MutatorThreadSweepingScope final {
    public:
@@ -701,33 +728,12 @@ class Sweeper::SweeperImpl final {
 
    private:
     void Run(double deadline_in_seconds) override {
-      if (handle_.IsCanceled() || !sweeper_->is_in_progress_) return;
+      if (handle_.IsCanceled()) return;
 
-      MutatorThreadSweepingScope sweeping_in_progresss(*sweeper_);
-
-      bool sweep_complete;
-      {
-        StatsCollector::EnabledScope stats_scope(
-            sweeper_->stats_collector_, StatsCollector::kIncrementalSweep);
-
-        MutatorThreadSweeper sweeper(&sweeper_->space_states_,
-                                     sweeper_->platform_);
-        {
-          StatsCollector::EnabledScope stats_scope(
-              sweeper_->stats_collector_, StatsCollector::kSweepIdleStep,
-              "idleDeltaInSeconds",
-              (deadline_in_seconds -
-               sweeper_->platform_->MonotonicallyIncreasingTime()));
-
-          sweep_complete = sweeper.SweepWithDeadline(deadline_in_seconds);
-        }
-        if (sweep_complete) {
-          sweeper_->FinalizeSweep();
-        } else {
-          sweeper_->ScheduleIncrementalSweeping();
-        }
+      if (!sweeper_->PerformSweepOnMutatorThread(
+              deadline_in_seconds, StatsCollector::kSweepIdleStep)) {
+        sweeper_->ScheduleIncrementalSweeping();
       }
-      if (sweep_complete) sweeper_->NotifyDone();
     }
 
     Handle GetHandle() const { return handle_; }
@@ -807,5 +813,10 @@ bool Sweeper::IsSweepingInProgress() const {
   return impl_->IsSweepingInProgress();
 }
 
+bool Sweeper::PerformSweepOnMutatorThread(double deadline_in_seconds) {
+  return impl_->PerformSweepOnMutatorThread(deadline_in_seconds,
+                                            StatsCollector::kSweepInTask);
+}
+
 }  // namespace internal
 }  // namespace cppgc
diff --git a/chromium/v8/src/heap/cppgc/sweeper.h b/chromium/v8/src/heap/cppgc/sweeper.h
index 4c77ec69173..a13962aa914 100644
--- a/chromium/v8/src/heap/cppgc/sweeper.h
+++ b/chromium/v8/src/heap/cppgc/sweeper.h
@@ -9,6 +9,7 @@
 
 #include "include/cppgc/heap.h"
 #include "src/base/macros.h"
+#include "src/base/platform/time.h"
 
 namespace cppgc {
 
@@ -49,6 +50,9 @@ class V8_EXPORT_PRIVATE Sweeper final {
   bool IsSweepingOnMutatorThread() const;
   bool IsSweepingInProgress() const;
 
+  // Assist with sweeping. Returns true if sweeping is done.
+  bool PerformSweepOnMutatorThread(double deadline_in_seconds);
+
  private:
   void WaitForConcurrentSweepingForTesting();
 
diff --git a/chromium/v8/src/heap/cppgc/trace-trait.cc b/chromium/v8/src/heap/cppgc/trace-trait.cc
index bf3759881b4..df14e3698be 100644
--- a/chromium/v8/src/heap/cppgc/trace-trait.cc
+++ b/chromium/v8/src/heap/cppgc/trace-trait.cc
@@ -18,9 +18,10 @@ TraceDescriptor TraceTraitFromInnerAddressImpl::GetTraceDescriptor(
   page->SynchronizedLoad();
   const HeapObjectHeader& header =
       page->ObjectHeaderFromInnerAddress<AccessMode::kAtomic>(address);
-  return {header.Payload(), GlobalGCInfoTable::GCInfoFromIndex(
-                                header.GetGCInfoIndex<AccessMode::kAtomic>())
-                                .trace};
+  return {header.ObjectStart(),
+          GlobalGCInfoTable::GCInfoFromIndex(
+              header.GetGCInfoIndex<AccessMode::kAtomic>())
+              .trace};
 }
 
 }  // namespace internal
diff --git a/chromium/v8/src/heap/cppgc/visitor.cc b/chromium/v8/src/heap/cppgc/visitor.cc
index 33786f6fce3..9d90e4ab3e3 100644
--- a/chromium/v8/src/heap/cppgc/visitor.cc
+++ b/chromium/v8/src/heap/cppgc/visitor.cc
@@ -4,11 +4,12 @@
 
 #include "src/heap/cppgc/visitor.h"
 
+#include "src/base/sanitizer/msan.h"
 #include "src/heap/cppgc/gc-info-table.h"
 #include "src/heap/cppgc/heap-object-header.h"
 #include "src/heap/cppgc/heap-page.h"
+#include "src/heap/cppgc/object-view.h"
 #include "src/heap/cppgc/page-memory.h"
-#include "src/heap/cppgc/sanitizers.h"
 
 namespace cppgc {
 
@@ -29,15 +30,15 @@ namespace {
 
 void TraceConservatively(ConservativeTracingVisitor* conservative_visitor,
                          const HeapObjectHeader& header) {
-  Address* payload = reinterpret_cast<Address*>(header.Payload());
-  const size_t payload_size = header.GetSize();
-  for (size_t i = 0; i < (payload_size / sizeof(Address)); ++i) {
-    Address maybe_ptr = payload[i];
+  const auto object_view = ObjectView(header);
+  Address* object = reinterpret_cast<Address*>(object_view.Start());
+  for (size_t i = 0; i < (object_view.Size() / sizeof(Address)); ++i) {
+    Address maybe_ptr = object[i];
 #if defined(MEMORY_SANITIZER)
-    // |payload| may be uninitialized by design or just contain padding bytes.
+    // |object| may be uninitialized by design or just contain padding bytes.
     // Copy into a local variable that is not poisoned for conservative marking.
     // Copy into a temporary variable to maintain the original MSAN state.
-    MSAN_UNPOISON(&maybe_ptr, sizeof(maybe_ptr));
+    MSAN_MEMORY_IS_INITIALIZED(&maybe_ptr, sizeof(maybe_ptr));
 #endif
     if (maybe_ptr) {
       conservative_visitor->TraceConservativelyIfNeeded(maybe_ptr);
@@ -49,8 +50,6 @@ void TraceConservatively(ConservativeTracingVisitor* conservative_visitor,
 
 void ConservativeTracingVisitor::TraceConservativelyIfNeeded(
     const void* address) {
-  // TODO(chromium:1056170): Add page bloom filter
-
   const BasePage* page = reinterpret_cast<const BasePage*>(
       page_backend_.Lookup(static_cast<ConstAddress>(address)));
 
@@ -78,8 +77,8 @@ void ConservativeTracingVisitor::TraceConservativelyIfNeeded(
 void ConservativeTracingVisitor::VisitFullyConstructedConservatively(
     HeapObjectHeader& header) {
   visitor_.Visit(
-      header.Payload(),
-      {header.Payload(),
+      header.ObjectStart(),
+      {header.ObjectStart(),
        GlobalGCInfoTable::GCInfoFromIndex(header.GetGCInfoIndex()).trace});
 }
 
diff --git a/chromium/v8/src/heap/embedder-tracing.cc b/chromium/v8/src/heap/embedder-tracing.cc
index 4fd747a964e..72bdde571a6 100644
--- a/chromium/v8/src/heap/embedder-tracing.cc
+++ b/chromium/v8/src/heap/embedder-tracing.cc
@@ -17,6 +17,7 @@ void LocalEmbedderHeapTracer::SetRemoteTracer(EmbedderHeapTracer* tracer) {
   if (remote_tracer_) remote_tracer_->isolate_ = nullptr;
 
   remote_tracer_ = tracer;
+  default_embedder_roots_handler_.SetTracer(tracer);
   if (remote_tracer_)
     remote_tracer_->isolate_ = reinterpret_cast<v8::Isolate*>(isolate_);
 }
@@ -75,9 +76,8 @@ void LocalEmbedderHeapTracer::SetEmbedderStackStateForNextFinalization(
   if (!InUse()) return;
 
   embedder_stack_state_ = stack_state;
-  if (EmbedderHeapTracer::EmbedderStackState::kNoHeapPointers == stack_state) {
-    remote_tracer()->NotifyEmptyEmbedderStack();
-  }
+  if (EmbedderHeapTracer::EmbedderStackState::kNoHeapPointers == stack_state)
+    NotifyEmptyEmbedderStack();
 }
 
 namespace {
@@ -164,5 +164,33 @@ void LocalEmbedderHeapTracer::StartIncrementalMarkingIfNeeded() {
   }
 }
 
+void LocalEmbedderHeapTracer::NotifyEmptyEmbedderStack() {
+  auto* overriden_stack_state = isolate_->heap()->overriden_stack_state();
+  if (overriden_stack_state &&
+      (*overriden_stack_state ==
+       cppgc::EmbedderStackState::kMayContainHeapPointers))
+    return;
+
+  isolate_->global_handles()->NotifyEmptyEmbedderStack();
+}
+
+bool DefaultEmbedderRootsHandler::IsRoot(
+    const v8::TracedReference<v8::Value>& handle) {
+  return !tracer_ || tracer_->IsRootForNonTracingGC(handle);
+}
+
+bool DefaultEmbedderRootsHandler::IsRoot(
+    const v8::TracedGlobal<v8::Value>& handle) {
+  return !tracer_ || tracer_->IsRootForNonTracingGC(handle);
+}
+
+void DefaultEmbedderRootsHandler::ResetRoot(
+    const v8::TracedReference<v8::Value>& handle) {
+  // Resetting is only called when IsRoot() returns false which
+  // can only happen the EmbedderHeapTracer is set on API level.
+  DCHECK(tracer_);
+  tracer_->ResetHandleInNonTracingGC(handle);
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/heap/embedder-tracing.h b/chromium/v8/src/heap/embedder-tracing.h
index 8a1b14a32b4..befb1a7e7ac 100644
--- a/chromium/v8/src/heap/embedder-tracing.h
+++ b/chromium/v8/src/heap/embedder-tracing.h
@@ -16,6 +16,19 @@ namespace internal {
 class Heap;
 class JSObject;
 
+class V8_EXPORT_PRIVATE DefaultEmbedderRootsHandler final
+    : public EmbedderRootsHandler {
+ public:
+  bool IsRoot(const v8::TracedReference<v8::Value>& handle) final;
+  bool IsRoot(const v8::TracedGlobal<v8::Value>& handle) final;
+  void ResetRoot(const v8::TracedReference<v8::Value>& handle) final;
+
+  void SetTracer(EmbedderHeapTracer* tracer) { tracer_ = tracer; }
+
+ private:
+  EmbedderHeapTracer* tracer_ = nullptr;
+};
+
 class V8_EXPORT_PRIVATE LocalEmbedderHeapTracer final {
  public:
   using WrapperInfo = std::pair<void*, void*>;
@@ -74,21 +87,6 @@ class V8_EXPORT_PRIVATE LocalEmbedderHeapTracer final {
   bool Trace(double deadline);
   bool IsRemoteTracingDone();
 
-  bool IsRootForNonTracingGC(const v8::TracedGlobal<v8::Value>& handle) {
-    return !InUse() || remote_tracer_->IsRootForNonTracingGC(handle);
-  }
-
-  bool IsRootForNonTracingGC(const v8::TracedReference<v8::Value>& handle) {
-    return !InUse() || remote_tracer_->IsRootForNonTracingGC(handle);
-  }
-
-  void ResetHandleInNonTracingGC(const v8::TracedReference<v8::Value>& handle) {
-    // Resetting is only called when IsRootForNonTracingGC returns false which
-    // can only happen the EmbedderHeapTracer is set on API level.
-    DCHECK(InUse());
-    remote_tracer_->ResetHandleInNonTracingGC(handle);
-  }
-
   bool ShouldFinalizeIncrementalMarking() {
     return !FLAG_incremental_marking_wrappers || !InUse() ||
            (IsRemoteTracingDone() && embedder_worklist_empty_);
@@ -130,6 +128,12 @@ class V8_EXPORT_PRIVATE LocalEmbedderHeapTracer final {
 
   void UpdateRemoteStats(size_t, double);
 
+  DefaultEmbedderRootsHandler& default_embedder_roots_handler() {
+    return default_embedder_roots_handler_;
+  }
+
+  void NotifyEmptyEmbedderStack();
+
  private:
   static constexpr size_t kEmbedderAllocatedThreshold = 128 * KB;
 
@@ -147,6 +151,7 @@ class V8_EXPORT_PRIVATE LocalEmbedderHeapTracer final {
 
   Isolate* const isolate_;
   EmbedderHeapTracer* remote_tracer_ = nullptr;
+  DefaultEmbedderRootsHandler default_embedder_roots_handler_;
 
   EmbedderHeapTracer::EmbedderStackState embedder_stack_state_ =
       EmbedderHeapTracer::EmbedderStackState::kMayContainHeapPointers;
@@ -183,11 +188,8 @@ class V8_EXPORT_PRIVATE V8_NODISCARD EmbedderStackStateScope final {
       : local_tracer_(local_tracer),
         old_stack_state_(local_tracer_->embedder_stack_state_) {
     local_tracer_->embedder_stack_state_ = stack_state;
-    if (EmbedderHeapTracer::EmbedderStackState::kNoHeapPointers ==
-        stack_state) {
-      if (local_tracer->remote_tracer())
-        local_tracer->remote_tracer()->NotifyEmptyEmbedderStack();
-    }
+    if (EmbedderHeapTracer::EmbedderStackState::kNoHeapPointers == stack_state)
+      local_tracer_->NotifyEmptyEmbedderStack();
   }
 
   ~EmbedderStackStateScope() {
diff --git a/chromium/v8/src/heap/factory-base-inl.h b/chromium/v8/src/heap/factory-base-inl.h
index 6f218b8248c..6c1cede212c 100644
--- a/chromium/v8/src/heap/factory-base-inl.h
+++ b/chromium/v8/src/heap/factory-base-inl.h
@@ -6,9 +6,10 @@
 #define V8_HEAP_FACTORY_BASE_INL_H_
 
 #include "src/heap/factory-base.h"
-
 #include "src/numbers/conversions.h"
 #include "src/objects/heap-number.h"
+#include "src/objects/map.h"
+#include "src/objects/slots-inl.h"
 #include "src/objects/smi.h"
 #include "src/roots/roots.h"
 
@@ -93,6 +94,29 @@ Handle<HeapNumber> FactoryBase<Impl>::NewHeapNumberWithHoleNaN() {
   return NewHeapNumberFromBits<allocation>(kHoleNanInt64);
 }
 
+template <typename Impl>
+template <typename StructType>
+StructType FactoryBase<Impl>::NewStructInternal(InstanceType type,
+                                                AllocationType allocation) {
+  ReadOnlyRoots roots = read_only_roots();
+  Map map = Map::GetInstanceTypeMap(roots, type);
+  int size = StructType::kSize;
+  return StructType::cast(NewStructInternal(roots, map, size, allocation));
+}
+
+template <typename Impl>
+Struct FactoryBase<Impl>::NewStructInternal(ReadOnlyRoots roots, Map map,
+                                            int size,
+                                            AllocationType allocation) {
+  DCHECK_EQ(size, map.instance_size());
+  HeapObject result = AllocateRawWithImmortalMap(size, allocation, map);
+  Struct str = Struct::cast(result);
+  Object value = roots.undefined_value();
+  int length = (size >> kTaggedSizeLog2) - 1;
+  MemsetTagged(str.RawField(Struct::kHeaderSize), value, length);
+  return str;
+}
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/chromium/v8/src/heap/factory-base.cc b/chromium/v8/src/heap/factory-base.cc
index 45577f7bf91..df78716a8de 100644
--- a/chromium/v8/src/heap/factory-base.cc
+++ b/chromium/v8/src/heap/factory-base.cc
@@ -53,36 +53,30 @@ FactoryBase<LocalFactory>::NewHeapNumber<AllocationType::kOld>();
 template <typename Impl>
 Handle<Struct> FactoryBase<Impl>::NewStruct(InstanceType type,
                                             AllocationType allocation) {
-  return handle(NewStructInternal(type, allocation), isolate());
-}
-
-template <typename Impl>
-Struct FactoryBase<Impl>::NewStructInternal(InstanceType type,
-                                            AllocationType allocation) {
-  Map map = Map::GetInstanceTypeMap(read_only_roots(), type);
+  ReadOnlyRoots roots = read_only_roots();
+  Map map = Map::GetInstanceTypeMap(roots, type);
   int size = map.instance_size();
-  HeapObject result = AllocateRawWithImmortalMap(size, allocation, map);
-  Struct str = Struct::cast(result);
-  str.InitializeBody(size);
-  return str;
+  return handle(NewStructInternal(roots, map, size, allocation), isolate());
 }
 
 template <typename Impl>
 Handle<AccessorPair> FactoryBase<Impl>::NewAccessorPair() {
-  Handle<AccessorPair> accessors = Handle<AccessorPair>::cast(
-      NewStruct(ACCESSOR_PAIR_TYPE, AllocationType::kOld));
-  AccessorPair raw = *accessors;
+  auto accessors =
+      NewStructInternal<AccessorPair>(ACCESSOR_PAIR_TYPE, AllocationType::kOld);
   DisallowGarbageCollection no_gc;
-  raw.set_getter(read_only_roots().null_value(), SKIP_WRITE_BARRIER);
-  raw.set_setter(read_only_roots().null_value(), SKIP_WRITE_BARRIER);
-  return accessors;
+  accessors.set_getter(read_only_roots().null_value(), SKIP_WRITE_BARRIER);
+  accessors.set_setter(read_only_roots().null_value(), SKIP_WRITE_BARRIER);
+  return handle(accessors, isolate());
 }
 
 template <typename Impl>
 Handle<FixedArray> FactoryBase<Impl>::NewFixedArray(int length,
                                                     AllocationType allocation) {
-  DCHECK_LE(0, length);
   if (length == 0) return impl()->empty_fixed_array();
+  if (length < 0 || length > FixedArray::kMaxLength) {
+    FATAL("Fatal JavaScript invalid size error %d", length);
+    UNREACHABLE();
+  }
   return NewFixedArrayWithFiller(
       read_only_roots().fixed_array_map_handle(), length,
       read_only_roots().undefined_value_handle(), allocation);
@@ -128,7 +122,8 @@ Handle<FixedArrayBase> FactoryBase<Impl>::NewFixedDoubleArray(
     int length, AllocationType allocation) {
   if (length == 0) return impl()->empty_fixed_array();
   if (length < 0 || length > FixedDoubleArray::kMaxLength) {
-    isolate()->FatalProcessOutOfHeapMemory("invalid array length");
+    FATAL("Fatal JavaScript invalid size error %d", length);
+    UNREACHABLE();
   }
   int size = FixedDoubleArray::SizeFor(length);
   Map map = read_only_roots().fixed_double_array_map();
@@ -172,7 +167,8 @@ template <typename Impl>
 Handle<ByteArray> FactoryBase<Impl>::NewByteArray(int length,
                                                   AllocationType allocation) {
   if (length < 0 || length > ByteArray::kMaxLength) {
-    isolate()->FatalProcessOutOfHeapMemory("invalid array length");
+    FATAL("Fatal JavaScript invalid size error %d", length);
+    UNREACHABLE();
   }
   int size = ByteArray::SizeFor(length);
   HeapObject result = AllocateRawWithImmortalMap(
@@ -189,7 +185,8 @@ Handle<BytecodeArray> FactoryBase<Impl>::NewBytecodeArray(
     int length, const byte* raw_bytecodes, int frame_size, int parameter_count,
     Handle<FixedArray> constant_pool) {
   if (length < 0 || length > BytecodeArray::kMaxLength) {
-    isolate()->FatalProcessOutOfHeapMemory("invalid array length");
+    FATAL("Fatal JavaScript invalid size error %d", length);
+    UNREACHABLE();
   }
   // Bytecode array is AllocationType::kOld, so constant pool array should be
   // too.
@@ -230,8 +227,8 @@ Handle<Script> FactoryBase<Impl>::NewScriptWithId(
   DCHECK(source->IsString() || source->IsUndefined());
   // Create and initialize script object.
   ReadOnlyRoots roots = read_only_roots();
-  Handle<Script> script =
-      Handle<Script>::cast(NewStruct(SCRIPT_TYPE, AllocationType::kOld));
+  Handle<Script> script = handle(
+      NewStructInternal<Script>(SCRIPT_TYPE, AllocationType::kOld), isolate());
   {
     DisallowGarbageCollection no_gc;
     Script raw = *script;
@@ -243,8 +240,8 @@ Handle<Script> FactoryBase<Impl>::NewScriptWithId(
     raw.set_context_data(roots.undefined_value(), SKIP_WRITE_BARRIER);
     raw.set_type(Script::TYPE_NORMAL);
     raw.set_line_ends(roots.undefined_value(), SKIP_WRITE_BARRIER);
-    raw.set_eval_from_shared_or_wrapped_arguments(roots.undefined_value(),
-                                                  SKIP_WRITE_BARRIER);
+    raw.set_eval_from_shared_or_wrapped_arguments_or_sfi_table(
+        roots.undefined_value(), SKIP_WRITE_BARRIER);
     raw.set_eval_from_position(0);
     raw.set_shared_function_infos(roots.empty_weak_fixed_array(),
                                   SKIP_WRITE_BARRIER);
@@ -394,14 +391,12 @@ template <typename Impl>
 Handle<ArrayBoilerplateDescription>
 FactoryBase<Impl>::NewArrayBoilerplateDescription(
     ElementsKind elements_kind, Handle<FixedArrayBase> constant_values) {
-  Handle<ArrayBoilerplateDescription> result =
-      Handle<ArrayBoilerplateDescription>::cast(
-          NewStruct(ARRAY_BOILERPLATE_DESCRIPTION_TYPE, AllocationType::kOld));
+  auto result = NewStructInternal<ArrayBoilerplateDescription>(
+      ARRAY_BOILERPLATE_DESCRIPTION_TYPE, AllocationType::kOld);
   DisallowGarbageCollection no_gc;
-  ArrayBoilerplateDescription raw = *result;
-  raw.set_elements_kind(elements_kind);
-  raw.set_constant_elements(*constant_values);
-  return result;
+  result.set_elements_kind(elements_kind);
+  result.set_constant_elements(*constant_values);
+  return handle(result, isolate());
 }
 
 template <typename Impl>
@@ -409,15 +404,13 @@ Handle<RegExpBoilerplateDescription>
 FactoryBase<Impl>::NewRegExpBoilerplateDescription(Handle<FixedArray> data,
                                                    Handle<String> source,
                                                    Smi flags) {
-  Handle<RegExpBoilerplateDescription> result =
-      Handle<RegExpBoilerplateDescription>::cast(NewStruct(
-          REG_EXP_BOILERPLATE_DESCRIPTION_TYPE, AllocationType::kOld));
+  auto result = NewStructInternal<RegExpBoilerplateDescription>(
+      REG_EXP_BOILERPLATE_DESCRIPTION_TYPE, AllocationType::kOld);
   DisallowGarbageCollection no_gc;
-  RegExpBoilerplateDescription raw = *result;
-  raw.set_data(*data);
-  raw.set_source(*source);
-  raw.set_flags(flags.value());
-  return result;
+  result.set_data(*data);
+  result.set_source(*source);
+  result.set_flags(flags.value());
+  return handle(result, isolate());
 }
 
 template <typename Impl>
@@ -426,14 +419,12 @@ FactoryBase<Impl>::NewTemplateObjectDescription(
     Handle<FixedArray> raw_strings, Handle<FixedArray> cooked_strings) {
   DCHECK_EQ(raw_strings->length(), cooked_strings->length());
   DCHECK_LT(0, raw_strings->length());
-  Handle<TemplateObjectDescription> result =
-      Handle<TemplateObjectDescription>::cast(
-          NewStruct(TEMPLATE_OBJECT_DESCRIPTION_TYPE, AllocationType::kOld));
+  auto result = NewStructInternal<TemplateObjectDescription>(
+      TEMPLATE_OBJECT_DESCRIPTION_TYPE, AllocationType::kOld);
   DisallowGarbageCollection no_gc;
-  TemplateObjectDescription raw = *result;
-  raw.set_raw_strings(*raw_strings);
-  raw.set_cooked_strings(*cooked_strings);
-  return result;
+  result.set_raw_strings(*raw_strings);
+  result.set_cooked_strings(*cooked_strings);
+  return handle(result, isolate());
 }
 
 template <typename Impl>
@@ -691,7 +682,8 @@ template <typename Impl>
 Handle<FreshlyAllocatedBigInt> FactoryBase<Impl>::NewBigInt(
     int length, AllocationType allocation) {
   if (length < 0 || length > BigInt::kMaxLength) {
-    isolate()->FatalProcessOutOfHeapMemory("invalid BigInt length");
+    FATAL("Fatal JavaScript invalid size error %d", length);
+    UNREACHABLE();
   }
   HeapObject result = AllocateRawWithImmortalMap(
       BigInt::SizeFor(length), allocation, read_only_roots().bigint_map());
@@ -760,11 +752,11 @@ Handle<DescriptorArray> FactoryBase<Impl>::NewDescriptorArray(
 template <typename Impl>
 Handle<ClassPositions> FactoryBase<Impl>::NewClassPositions(int start,
                                                             int end) {
-  Handle<ClassPositions> class_positions = Handle<ClassPositions>::cast(
-      NewStruct(CLASS_POSITIONS_TYPE, AllocationType::kOld));
-  class_positions->set_start(start);
-  class_positions->set_end(end);
-  return class_positions;
+  auto result = NewStructInternal<ClassPositions>(CLASS_POSITIONS_TYPE,
+                                                  AllocationType::kOld);
+  result.set_start(start);
+  result.set_end(end);
+  return handle(result, isolate());
 }
 
 template <typename Impl>
@@ -825,7 +817,8 @@ template <typename Impl>
 HeapObject FactoryBase<Impl>::AllocateRawFixedArray(int length,
                                                     AllocationType allocation) {
   if (length < 0 || length > FixedArray::kMaxLength) {
-    isolate()->FatalProcessOutOfHeapMemory("invalid array length");
+    FATAL("Fatal JavaScript invalid size error %d", length);
+    UNREACHABLE();
   }
   return AllocateRawArray(FixedArray::SizeFor(length), allocation);
 }
@@ -834,7 +827,8 @@ template <typename Impl>
 HeapObject FactoryBase<Impl>::AllocateRawWeakArrayList(
     int capacity, AllocationType allocation) {
   if (capacity < 0 || capacity > WeakArrayList::kMaxCapacity) {
-    isolate()->FatalProcessOutOfHeapMemory("invalid array length");
+    FATAL("Fatal JavaScript invalid size error %d", capacity);
+    UNREACHABLE();
   }
   return AllocateRawArray(WeakArrayList::SizeForCapacity(capacity), allocation);
 }
@@ -878,8 +872,9 @@ FactoryBase<Impl>::NewSwissNameDictionaryWithCapacity(
     return read_only_roots().empty_swiss_property_dictionary_handle();
   }
 
-  if (capacity > SwissNameDictionary::MaxCapacity()) {
-    isolate()->FatalProcessOutOfHeapMemory("invalid table size");
+  if (capacity < 0 || capacity > SwissNameDictionary::MaxCapacity()) {
+    FATAL("Fatal JavaScript invalid size error %d", capacity);
+    UNREACHABLE();
   }
 
   int meta_table_length = SwissNameDictionary::MetaTableSizeFor(capacity);
@@ -902,6 +897,18 @@ Handle<SwissNameDictionary> FactoryBase<Impl>::NewSwissNameDictionary(
       SwissNameDictionary::CapacityFor(at_least_space_for), allocation);
 }
 
+template <typename Impl>
+Handle<FunctionTemplateRareData>
+FactoryBase<Impl>::NewFunctionTemplateRareData() {
+  auto function_template_rare_data =
+      NewStructInternal<FunctionTemplateRareData>(
+          FUNCTION_TEMPLATE_RARE_DATA_TYPE, AllocationType::kOld);
+  DisallowGarbageCollection no_gc;
+  function_template_rare_data.set_c_function_overloads(
+      *impl()->empty_fixed_array(), SKIP_WRITE_BARRIER);
+  return handle(function_template_rare_data, isolate());
+}
+
 // Instantiate FactoryBase for the two variants we want.
 template class EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE) FactoryBase<Factory>;
 template class EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
diff --git a/chromium/v8/src/heap/factory-base.h b/chromium/v8/src/heap/factory-base.h
index b964f6b2346..4e3d5efbe40 100644
--- a/chromium/v8/src/heap/factory-base.h
+++ b/chromium/v8/src/heap/factory-base.h
@@ -228,14 +228,19 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) FactoryBase
   Handle<SwissNameDictionary> NewSwissNameDictionaryWithCapacity(
       int capacity, AllocationType allocation);
 
+  Handle<FunctionTemplateRareData> NewFunctionTemplateRareData();
+
  protected:
   // Allocate memory for an uninitialized array (e.g., a FixedArray or similar).
   HeapObject AllocateRawArray(int size, AllocationType allocation);
   HeapObject AllocateRawFixedArray(int length, AllocationType allocation);
   HeapObject AllocateRawWeakArrayList(int length, AllocationType allocation);
 
-  Struct NewStructInternal(InstanceType type,
-                           AllocationType allocation = AllocationType::kYoung);
+  template <typename StructType>
+  inline StructType NewStructInternal(InstanceType type,
+                                      AllocationType allocation);
+  Struct NewStructInternal(ReadOnlyRoots roots, Map map, int size,
+                           AllocationType allocation);
 
   HeapObject AllocateRawWithImmortalMap(
       int size, AllocationType allocation, Map map,
diff --git a/chromium/v8/src/heap/factory.cc b/chromium/v8/src/heap/factory.cc
index 0c89a3fa9cc..6f753d23b42 100644
--- a/chromium/v8/src/heap/factory.cc
+++ b/chromium/v8/src/heap/factory.cc
@@ -53,6 +53,7 @@
 #include "src/objects/js-regexp-inl.h"
 #include "src/objects/js-weak-refs-inl.h"
 #include "src/objects/literal-objects-inl.h"
+#include "src/objects/megadom-handler-inl.h"
 #include "src/objects/microtask-inl.h"
 #include "src/objects/module-inl.h"
 #include "src/objects/promise-inl.h"
@@ -153,9 +154,8 @@ MaybeHandle<Code> Factory::CodeBuilder::BuildInternal(
     if (is_executable_) {
       DCHECK(IsAligned(code->address(), kCodeAlignment));
       DCHECK_IMPLIES(
-          !V8_ENABLE_THIRD_PARTY_HEAP_BOOL &&
-              !heap->memory_allocator()->code_range().is_empty(),
-          heap->memory_allocator()->code_range().contains(code->address()));
+          !V8_ENABLE_THIRD_PARTY_HEAP_BOOL && !heap->code_region().is_empty(),
+          heap->code_region().contains(code->address()));
     }
 
     constexpr bool kIsNotOffHeapTrampoline = false;
@@ -314,8 +314,8 @@ Handle<HeapObject> Factory::NewFillerObject(int size, bool double_align,
 }
 
 Handle<PrototypeInfo> Factory::NewPrototypeInfo() {
-  PrototypeInfo result = PrototypeInfo::cast(
-      NewStructInternal(PROTOTYPE_INFO_TYPE, AllocationType::kOld));
+  auto result = NewStructInternal<PrototypeInfo>(PROTOTYPE_INFO_TYPE,
+                                                 AllocationType::kOld);
   DisallowGarbageCollection no_gc;
   result.set_prototype_users(Smi::zero());
   result.set_registry_slot(PrototypeInfo::UNREGISTERED);
@@ -326,8 +326,8 @@ Handle<PrototypeInfo> Factory::NewPrototypeInfo() {
 
 Handle<EnumCache> Factory::NewEnumCache(Handle<FixedArray> keys,
                                         Handle<FixedArray> indices) {
-  EnumCache result =
-      EnumCache::cast(NewStructInternal(ENUM_CACHE_TYPE, AllocationType::kOld));
+  auto result =
+      NewStructInternal<EnumCache>(ENUM_CACHE_TYPE, AllocationType::kOld);
   DisallowGarbageCollection no_gc;
   result.set_keys(*keys);
   result.set_indices(*indices);
@@ -336,7 +336,7 @@ Handle<EnumCache> Factory::NewEnumCache(Handle<FixedArray> keys,
 
 Handle<Tuple2> Factory::NewTuple2(Handle<Object> value1, Handle<Object> value2,
                                   AllocationType allocation) {
-  Tuple2 result = Tuple2::cast(NewStructInternal(TUPLE2_TYPE, allocation));
+  auto result = NewStructInternal<Tuple2>(TUPLE2_TYPE, allocation);
   DisallowGarbageCollection no_gc;
   result.set_value1(*value1);
   result.set_value2(*value2);
@@ -345,8 +345,8 @@ Handle<Tuple2> Factory::NewTuple2(Handle<Object> value1, Handle<Object> value2,
 
 Handle<BaselineData> Factory::NewBaselineData(
     Handle<Code> code, Handle<HeapObject> function_data) {
-  BaselineData baseline_data = BaselineData::cast(
-      NewStructInternal(BASELINE_DATA_TYPE, AllocationType::kOld));
+  auto baseline_data =
+      NewStructInternal<BaselineData>(BASELINE_DATA_TYPE, AllocationType::kOld);
   DisallowGarbageCollection no_gc;
   baseline_data.set_baseline_code(*code);
   baseline_data.set_data(*function_data);
@@ -410,20 +410,6 @@ MaybeHandle<FixedArray> Factory::TryNewFixedArray(
   return handle(array, isolate());
 }
 
-Handle<FixedArray> Factory::NewUninitializedFixedArray(int length) {
-  if (length == 0) return empty_fixed_array();
-  if (length < 0 || length > FixedArray::kMaxLength) {
-    isolate()->heap()->FatalProcessOutOfMemory("invalid array length");
-  }
-
-  // TODO(ulan): As an experiment this temporarily returns an initialized fixed
-  // array. After getting canary/performance coverage, either remove the
-  // function or revert to returning uninitilized array.
-  return NewFixedArrayWithFiller(read_only_roots().fixed_array_map_handle(),
-                                 length, undefined_value(),
-                                 AllocationType::kYoung);
-}
-
 Handle<ClosureFeedbackCellArray> Factory::NewClosureFeedbackCellArray(
     int length) {
   if (length == 0) return empty_closure_feedback_cell_array();
@@ -557,9 +543,8 @@ Handle<NameDictionary> Factory::NewNameDictionary(int at_least_space_for) {
 }
 
 Handle<PropertyDescriptorObject> Factory::NewPropertyDescriptorObject() {
-  PropertyDescriptorObject object =
-      PropertyDescriptorObject::cast(NewStructInternal(
-          PROPERTY_DESCRIPTOR_OBJECT_TYPE, AllocationType::kYoung));
+  auto object = NewStructInternal<PropertyDescriptorObject>(
+      PROPERTY_DESCRIPTOR_OBJECT_TYPE, AllocationType::kYoung);
   DisallowGarbageCollection no_gc;
   object.set_flags(0);
   Oddball the_hole = read_only_roots().the_hole_value();
@@ -1095,7 +1080,7 @@ Handle<NativeContext> Factory::NewNativeContext() {
   // The ExternalPointerTable is a C++ object.
   context.AllocateExternalPointerEntries(isolate());
   context.set_scope_info(*native_scope_info());
-  context.set_previous(Context::unchecked_cast(Smi::zero()));
+  context.set_previous(Context());
   context.set_extension(*undefined_value());
   context.set_errors_thrown(Smi::zero());
   context.set_math_random_index(Smi::zero());
@@ -1179,7 +1164,7 @@ Handle<Context> Factory::NewCatchContext(Handle<Context> previous,
       isolate()->catch_context_map(), Context::SizeFor(variadic_part_length),
       variadic_part_length, AllocationType::kYoung);
   DisallowGarbageCollection no_gc;
-  DCHECK(Heap::InYoungGeneration(context));
+  DCHECK_IMPLIES(!FLAG_single_generation, Heap::InYoungGeneration(context));
   context.set_scope_info(*scope_info, SKIP_WRITE_BARRIER);
   context.set_previous(*previous, SKIP_WRITE_BARRIER);
   context.set(Context::THROWN_OBJECT_INDEX, *thrown_object, SKIP_WRITE_BARRIER);
@@ -1204,7 +1189,7 @@ Handle<Context> Factory::NewDebugEvaluateContext(Handle<Context> previous,
                          Context::SizeFor(variadic_part_length),
                          variadic_part_length, AllocationType::kYoung);
   DisallowGarbageCollection no_gc;
-  DCHECK(Heap::InYoungGeneration(context));
+  DCHECK_IMPLIES(!FLAG_single_generation, Heap::InYoungGeneration(context));
   context.set_scope_info(*scope_info, SKIP_WRITE_BARRIER);
   context.set_previous(*previous, SKIP_WRITE_BARRIER);
   context.set_extension(*ext, SKIP_WRITE_BARRIER);
@@ -1227,7 +1212,7 @@ Handle<Context> Factory::NewWithContext(Handle<Context> previous,
       isolate()->with_context_map(), Context::SizeFor(variadic_part_length),
       variadic_part_length, AllocationType::kYoung);
   DisallowGarbageCollection no_gc;
-  DCHECK(Heap::InYoungGeneration(context));
+  DCHECK_IMPLIES(!FLAG_single_generation, Heap::InYoungGeneration(context));
   context.set_scope_info(*scope_info, SKIP_WRITE_BARRIER);
   context.set_previous(*previous, SKIP_WRITE_BARRIER);
   context.set_extension(*extension, SKIP_WRITE_BARRIER);
@@ -1243,7 +1228,7 @@ Handle<Context> Factory::NewBlockContext(Handle<Context> previous,
       isolate()->block_context_map(), Context::SizeFor(variadic_part_length),
       variadic_part_length, AllocationType::kYoung);
   DisallowGarbageCollection no_gc;
-  DCHECK(Heap::InYoungGeneration(context));
+  DCHECK_IMPLIES(!FLAG_single_generation, Heap::InYoungGeneration(context));
   context.set_scope_info(*scope_info, SKIP_WRITE_BARRIER);
   context.set_previous(*previous, SKIP_WRITE_BARRIER);
   return handle(context, isolate());
@@ -1256,7 +1241,7 @@ Handle<Context> Factory::NewBuiltinContext(Handle<NativeContext> native_context,
       isolate()->function_context_map(), Context::SizeFor(variadic_part_length),
       variadic_part_length, AllocationType::kYoung);
   DisallowGarbageCollection no_gc;
-  DCHECK(Heap::InYoungGeneration(context));
+  DCHECK_IMPLIES(!FLAG_single_generation, Heap::InYoungGeneration(context));
   context.set_scope_info(read_only_roots().empty_scope_info(),
                          SKIP_WRITE_BARRIER);
   context.set_previous(*native_context, SKIP_WRITE_BARRIER);
@@ -1265,15 +1250,15 @@ Handle<Context> Factory::NewBuiltinContext(Handle<NativeContext> native_context,
 
 Handle<AliasedArgumentsEntry> Factory::NewAliasedArgumentsEntry(
     int aliased_context_slot) {
-  AliasedArgumentsEntry entry = AliasedArgumentsEntry::cast(
-      NewStructInternal(ALIASED_ARGUMENTS_ENTRY_TYPE, AllocationType::kYoung));
+  auto entry = NewStructInternal<AliasedArgumentsEntry>(
+      ALIASED_ARGUMENTS_ENTRY_TYPE, AllocationType::kYoung);
   entry.set_aliased_context_slot(aliased_context_slot);
   return handle(entry, isolate());
 }
 
 Handle<AccessorInfo> Factory::NewAccessorInfo() {
-  AccessorInfo info = AccessorInfo::cast(
-      NewStructInternal(ACCESSOR_INFO_TYPE, AllocationType::kOld));
+  auto info =
+      NewStructInternal<AccessorInfo>(ACCESSOR_INFO_TYPE, AllocationType::kOld);
   DisallowGarbageCollection no_gc;
   info.set_name(*empty_string(), SKIP_WRITE_BARRIER);
   info.set_flags(0);  // Must clear the flags, it was initialized as undefined.
@@ -1311,8 +1296,8 @@ Handle<Script> Factory::CloneScript(Handle<Script> script) {
     new_script.set_context_data(old_script.context_data());
     new_script.set_type(old_script.type());
     new_script.set_line_ends(*undefined_value(), SKIP_WRITE_BARRIER);
-    new_script.set_eval_from_shared_or_wrapped_arguments(
-        script->eval_from_shared_or_wrapped_arguments());
+    new_script.set_eval_from_shared_or_wrapped_arguments_or_sfi_table(
+        script->eval_from_shared_or_wrapped_arguments_or_sfi_table());
     new_script.set_shared_function_infos(*empty_weak_fixed_array(),
                                          SKIP_WRITE_BARRIER);
     new_script.set_eval_from_position(old_script.eval_from_position());
@@ -1330,8 +1315,8 @@ Handle<Script> Factory::CloneScript(Handle<Script> script) {
 Handle<CallableTask> Factory::NewCallableTask(Handle<JSReceiver> callable,
                                               Handle<Context> context) {
   DCHECK(callable->IsCallable());
-  CallableTask microtask = CallableTask::cast(
-      NewStructInternal(CALLABLE_TASK_TYPE, AllocationType::kYoung));
+  auto microtask = NewStructInternal<CallableTask>(CALLABLE_TASK_TYPE,
+                                                   AllocationType::kYoung);
   DisallowGarbageCollection no_gc;
   microtask.set_callable(*callable, SKIP_WRITE_BARRIER);
   microtask.set_context(*context, SKIP_WRITE_BARRIER);
@@ -1340,8 +1325,8 @@ Handle<CallableTask> Factory::NewCallableTask(Handle<JSReceiver> callable,
 
 Handle<CallbackTask> Factory::NewCallbackTask(Handle<Foreign> callback,
                                               Handle<Foreign> data) {
-  CallbackTask microtask = CallbackTask::cast(
-      NewStructInternal(CALLBACK_TASK_TYPE, AllocationType::kYoung));
+  auto microtask = NewStructInternal<CallbackTask>(CALLBACK_TASK_TYPE,
+                                                   AllocationType::kYoung);
   DisallowGarbageCollection no_gc;
   microtask.set_callback(*callback, SKIP_WRITE_BARRIER);
   microtask.set_data(*data, SKIP_WRITE_BARRIER);
@@ -1352,9 +1337,8 @@ Handle<PromiseResolveThenableJobTask> Factory::NewPromiseResolveThenableJobTask(
     Handle<JSPromise> promise_to_resolve, Handle<JSReceiver> thenable,
     Handle<JSReceiver> then, Handle<Context> context) {
   DCHECK(then->IsCallable());
-  PromiseResolveThenableJobTask microtask =
-      PromiseResolveThenableJobTask::cast(NewStructInternal(
-          PROMISE_RESOLVE_THENABLE_JOB_TASK_TYPE, AllocationType::kYoung));
+  auto microtask = NewStructInternal<PromiseResolveThenableJobTask>(
+      PROMISE_RESOLVE_THENABLE_JOB_TASK_TYPE, AllocationType::kYoung);
   DisallowGarbageCollection no_gc;
   microtask.set_promise_to_resolve(*promise_to_resolve, SKIP_WRITE_BARRIER);
   microtask.set_thenable(*thenable, SKIP_WRITE_BARRIER);
@@ -1377,24 +1361,78 @@ Handle<Foreign> Factory::NewForeign(Address addr) {
 
 #if V8_ENABLE_WEBASSEMBLY
 Handle<WasmTypeInfo> Factory::NewWasmTypeInfo(Address type_address,
-                                              Handle<Map> opt_parent) {
+                                              Handle<Map> opt_parent,
+                                              int instance_size_bytes) {
+  // We pretenure WasmTypeInfo objects because they are refererenced by Maps,
+  // which are assumed to be long-lived. The supertypes list is constant
+  // after initialization, so we pretenure that too.
+  // The subtypes list, however, is expected to grow (and hence be replaced),
+  // so we don't pretenure it.
   Handle<ArrayList> subtypes = ArrayList::New(isolate(), 0);
   Handle<FixedArray> supertypes;
   if (opt_parent.is_null()) {
-    supertypes = NewUninitializedFixedArray(0);
+    supertypes = NewFixedArray(0);
   } else {
-    supertypes = CopyFixedArrayAndGrow(
-        handle(opt_parent->wasm_type_info().supertypes(), isolate()), 1);
+    supertypes = CopyArrayAndGrow(
+        handle(opt_parent->wasm_type_info().supertypes(), isolate()), 1,
+        AllocationType::kOld);
     supertypes->set(supertypes->length() - 1, *opt_parent);
   }
   Map map = *wasm_type_info_map();
   WasmTypeInfo result = WasmTypeInfo::cast(AllocateRawWithImmortalMap(
-      map.instance_size(), AllocationType::kYoung, map));
+      map.instance_size(), AllocationType::kOld, map));
   DisallowGarbageCollection no_gc;
   result.AllocateExternalPointerEntries(isolate());
   result.set_foreign_address(isolate(), type_address);
   result.set_supertypes(*supertypes, SKIP_WRITE_BARRIER);
-  result.set_subtypes(*subtypes, SKIP_WRITE_BARRIER);
+  result.set_subtypes(*subtypes);
+  result.set_instance_size(instance_size_bytes);
+  return handle(result, isolate());
+}
+
+Handle<WasmJSFunctionData> Factory::NewWasmJSFunctionData(
+    Address opt_call_target, Handle<JSReceiver> callable, int return_count,
+    int parameter_count, Handle<PodArray<wasm::ValueType>> serialized_sig,
+    Handle<Code> wrapper_code) {
+  Handle<Tuple2> pair = NewTuple2(null_value(), callable, AllocationType::kOld);
+  Map map = *wasm_js_function_data_map();
+  WasmJSFunctionData result =
+      WasmJSFunctionData::cast(AllocateRawWithImmortalMap(
+          map.instance_size(), AllocationType::kOld, map));
+  DisallowGarbageCollection no_gc;
+  result.AllocateExternalPointerEntries(isolate());
+  result.set_foreign_address(isolate(), opt_call_target);
+  result.set_ref(*pair);
+  result.set_serialized_return_count(return_count);
+  result.set_serialized_parameter_count(parameter_count);
+  result.set_serialized_signature(*serialized_sig);
+  result.set_wrapper_code(*wrapper_code);
+  // Default value, will be overwritten by the caller.
+  result.set_wasm_to_js_wrapper_code(
+      isolate()->heap()->builtin(Builtins::kAbort));
+  return handle(result, isolate());
+}
+
+Handle<WasmExportedFunctionData> Factory::NewWasmExportedFunctionData(
+    Handle<Code> export_wrapper, Handle<WasmInstanceObject> instance,
+    Address call_target, Handle<Object> ref, int func_index,
+    Address sig_address, int wrapper_budget) {
+  Handle<Foreign> sig_foreign = NewForeign(sig_address);
+  Map map = *wasm_exported_function_data_map();
+  WasmExportedFunctionData result =
+      WasmExportedFunctionData::cast(AllocateRawWithImmortalMap(
+          map.instance_size(), AllocationType::kOld, map));
+  DisallowGarbageCollection no_gc;
+  result.AllocateExternalPointerEntries(isolate());
+  result.set_foreign_address(isolate(), call_target);
+  result.set_ref(*ref);
+  result.set_wrapper_code(*export_wrapper);
+  result.set_instance(*instance);
+  result.set_function_index(func_index);
+  result.set_signature(*sig_foreign);
+  result.set_wrapper_budget(wrapper_budget);
+  result.set_c_wrapper_code(Smi::zero(), SKIP_WRITE_BARRIER);
+  result.set_packed_args_size(0);
   return handle(result, isolate());
 }
 
@@ -1566,9 +1604,7 @@ Map Factory::InitializeMap(Map map, InstanceType type, int instance_size,
   map.SetInstanceDescriptors(isolate(), *empty_descriptor_array(), 0);
   // Must be called only after |instance_type| and |instance_size| are set.
   map.set_visitor_id(Map::GetVisitorId(map));
-  // TODO(solanes, v8:7790, v8:11353): set_relaxed_bit_field could be an atomic
-  // set if TSAN could see the transitions happening in StoreIC.
-  map.set_relaxed_bit_field(0);
+  map.set_bit_field(0);
   map.set_bit_field2(Map::Bits2::NewTargetIsBaseBit::encode(true));
   int bit_field3 =
       Map::Bits3::EnumLengthBits::encode(kInvalidEnumCacheSentinel) |
@@ -1892,7 +1928,7 @@ Handle<JSObject> Factory::NewError(Handle<JSFunction> constructor,
 
   Handle<Object> no_caller;
   return ErrorUtils::Construct(isolate(), constructor, constructor, message,
-                               SKIP_NONE, no_caller,
+                               undefined_value(), SKIP_NONE, no_caller,
                                ErrorUtils::StackTraceCollection::kDetailed)
       .ToHandleChecked();
 }
@@ -2075,9 +2111,8 @@ Handle<Code> Factory::CopyCode(Handle<Code> code) {
 #endif
   DCHECK(IsAligned(new_code->address(), kCodeAlignment));
   DCHECK_IMPLIES(
-      !V8_ENABLE_THIRD_PARTY_HEAP_BOOL &&
-      !heap->memory_allocator()->code_range().is_empty(),
-      heap->memory_allocator()->code_range().contains(new_code->address()));
+      !V8_ENABLE_THIRD_PARTY_HEAP_BOOL && !heap->code_region().is_empty(),
+      heap->code_region().contains(new_code->address()));
   return new_code;
 }
 
@@ -2175,7 +2210,7 @@ Handle<JSGlobalObject> Factory::NewJSGlobalObject(
 
   // Set up the global object as a normalized object.
   global->set_global_dictionary(*dictionary, kReleaseStore);
-  global->synchronized_set_map(raw_map);
+  global->set_map(raw_map, kReleaseStore);
 
   // Make sure result is a global object with properties in dictionary.
   DCHECK(global->IsJSGlobalObject() && !global->HasFastProperties());
@@ -2212,13 +2247,9 @@ void Factory::InitializeJSObjectBody(JSObject obj, Map map, int start_offset) {
   // In case of Array subclassing the |map| could already be transitioned
   // to different elements kind from the initial map on which we track slack.
   bool in_progress = map.IsInobjectSlackTrackingInProgress();
-  Object filler;
-  if (in_progress) {
-    filler = *one_pointer_filler_map();
-  } else {
-    filler = *undefined_value();
-  }
-  obj.InitializeBody(map, start_offset, *undefined_value(), filler);
+  obj.InitializeBody(map, start_offset, in_progress,
+                     ReadOnlyRoots(isolate()).one_pointer_filler_map_word(),
+                     *undefined_value());
   if (in_progress) {
     map.FindRootMap(isolate()).InobjectSlackTrackingStep(isolate());
   }
@@ -2369,7 +2400,7 @@ Handle<FixedArrayBase> Factory::NewJSArrayStorage(
   } else {
     DCHECK(IsSmiOrObjectElementsKind(elements_kind));
     if (mode == DONT_INITIALIZE_ARRAY_ELEMENTS) {
-      elms = NewUninitializedFixedArray(capacity);
+      elms = NewFixedArray(capacity);
     } else {
       DCHECK(mode == INITIALIZE_ARRAY_ELEMENTS_WITH_HOLE);
       elms = NewFixedArrayWithHoles(capacity);
@@ -2444,7 +2475,8 @@ Handle<SourceTextModule> Factory::NewSourceTextModule(
   module.set_status(Module::kUninstantiated);
   module.set_exception(roots.the_hole_value(), SKIP_WRITE_BARRIER);
   module.set_top_level_capability(roots.undefined_value(), SKIP_WRITE_BARRIER);
-  module.set_import_meta(roots.the_hole_value(), SKIP_WRITE_BARRIER);
+  module.set_import_meta(roots.the_hole_value(), kReleaseStore,
+                         SKIP_WRITE_BARRIER);
   module.set_dfs_index(-1);
   module.set_dfs_ancestor_index(-1);
   module.set_flags(0);
@@ -2487,7 +2519,8 @@ Handle<JSArrayBuffer> Factory::NewJSArrayBuffer(
                   isolate());
   auto result =
       Handle<JSArrayBuffer>::cast(NewJSObjectFromMap(map, allocation));
-  result->Setup(SharedFlag::kNotShared, std::move(backing_store));
+  result->Setup(SharedFlag::kNotShared, ResizableFlag::kNotResizable,
+                std::move(backing_store));
   return result;
 }
 
@@ -2505,18 +2538,32 @@ MaybeHandle<JSArrayBuffer> Factory::NewJSArrayBufferAndBackingStore(
                   isolate());
   auto array_buffer =
       Handle<JSArrayBuffer>::cast(NewJSObjectFromMap(map, allocation));
-  array_buffer->Setup(SharedFlag::kNotShared, std::move(backing_store));
+  array_buffer->Setup(SharedFlag::kNotShared, ResizableFlag::kNotResizable,
+                      std::move(backing_store));
   return array_buffer;
 }
 
 Handle<JSArrayBuffer> Factory::NewJSSharedArrayBuffer(
     std::shared_ptr<BackingStore> backing_store) {
-  Handle<Map> map(
-      isolate()->native_context()->shared_array_buffer_fun().initial_map(),
-      isolate());
+  Handle<Map> map;
+  if (backing_store->is_resizable()) {
+    DCHECK(FLAG_harmony_rab_gsab);
+    map = Handle<Map>(isolate()
+                          ->native_context()
+                          ->growable_shared_array_buffer_fun()
+                          .initial_map(),
+                      isolate());
+  } else {
+    map = Handle<Map>(
+        isolate()->native_context()->shared_array_buffer_fun().initial_map(),
+        isolate());
+  }
   auto result = Handle<JSArrayBuffer>::cast(
       NewJSObjectFromMap(map, AllocationType::kYoung));
-  result->Setup(SharedFlag::kShared, std::move(backing_store));
+  ResizableFlag resizable = backing_store->is_resizable()
+                                ? ResizableFlag::kResizable
+                                : ResizableFlag::kNotResizable;
+  result->Setup(SharedFlag::kShared, resizable, std::move(backing_store));
   return result;
 }
 
@@ -2571,6 +2618,7 @@ void Factory::TypeAndSizeForElementsKind(ElementsKind kind,
     *element_size = sizeof(ctype);                \
     break;
     TYPED_ARRAYS(TYPED_ARRAY_CASE)
+    RAB_GSAB_TYPED_ARRAYS_WITH_TYPED_ARRAY_TYPE(TYPED_ARRAY_CASE)
 #undef TYPED_ARRAY_CASE
 
     default:
@@ -2653,6 +2701,8 @@ Handle<JSTypedArray> Factory::NewJSTypedArray(ExternalArrayType type,
   raw.AllocateExternalPointerEntries(isolate());
   raw.set_length(length);
   raw.SetOffHeapDataPtr(isolate(), buffer->backing_store(), byte_offset);
+  raw.set_is_length_tracking(false);
+  raw.set_is_backed_by_rab(!buffer->is_shared() && buffer->is_resizable());
   return typed_array;
 }
 
@@ -2791,7 +2841,7 @@ void Factory::ReinitializeJSGlobalProxy(Handle<JSGlobalProxy> object,
 
   // Reset the map for the object.
   JSGlobalProxy raw = *object;
-  raw.synchronized_set_map(*map);
+  raw.set_map(*map, kReleaseStore);
 
   // Reinitialize the object from the constructor map.
   InitializeJSObjectFromMap(raw, *raw_properties_or_hash, *map);
@@ -3016,11 +3066,11 @@ Handle<String> Factory::SizeToString(size_t value, bool check_cache) {
 Handle<DebugInfo> Factory::NewDebugInfo(Handle<SharedFunctionInfo> shared) {
   DCHECK(!shared->HasDebugInfo());
 
-  DebugInfo debug_info =
-      DebugInfo::cast(NewStructInternal(DEBUG_INFO_TYPE, AllocationType::kOld));
+  auto debug_info =
+      NewStructInternal<DebugInfo>(DEBUG_INFO_TYPE, AllocationType::kOld);
   DisallowGarbageCollection no_gc;
   SharedFunctionInfo raw_shared = *shared;
-  debug_info.set_flags(DebugInfo::kNone);
+  debug_info.set_flags(DebugInfo::kNone, kRelaxedStore);
   debug_info.set_shared(raw_shared);
   debug_info.set_debugger_hints(0);
   DCHECK_EQ(DebugInfo::kNoDebuggingId, debug_info.debugging_id());
@@ -3039,8 +3089,8 @@ Handle<DebugInfo> Factory::NewDebugInfo(Handle<SharedFunctionInfo> shared) {
 }
 
 Handle<BreakPointInfo> Factory::NewBreakPointInfo(int source_position) {
-  BreakPointInfo new_break_point_info = BreakPointInfo::cast(
-      NewStructInternal(BREAK_POINT_INFO_TYPE, AllocationType::kOld));
+  auto new_break_point_info = NewStructInternal<BreakPointInfo>(
+      BREAK_POINT_INFO_TYPE, AllocationType::kOld);
   DisallowGarbageCollection no_gc;
   new_break_point_info.set_source_position(source_position);
   new_break_point_info.set_break_points(*undefined_value(), SKIP_WRITE_BARRIER);
@@ -3048,8 +3098,8 @@ Handle<BreakPointInfo> Factory::NewBreakPointInfo(int source_position) {
 }
 
 Handle<BreakPoint> Factory::NewBreakPoint(int id, Handle<String> condition) {
-  BreakPoint new_break_point = BreakPoint::cast(
-      NewStructInternal(BREAK_POINT_TYPE, AllocationType::kOld));
+  auto new_break_point =
+      NewStructInternal<BreakPoint>(BREAK_POINT_TYPE, AllocationType::kOld);
   DisallowGarbageCollection no_gc;
   new_break_point.set_id(id);
   new_break_point.set_condition(*condition);
@@ -3060,8 +3110,8 @@ Handle<StackFrameInfo> Factory::NewStackFrameInfo(
     Handle<Object> receiver_or_instance, Handle<Object> function,
     Handle<HeapObject> code_object, int code_offset_or_source_position,
     int flags, Handle<FixedArray> parameters) {
-  StackFrameInfo info = StackFrameInfo::cast(
-      NewStructInternal(STACK_FRAME_INFO_TYPE, AllocationType::kYoung));
+  auto info = NewStructInternal<StackFrameInfo>(STACK_FRAME_INFO_TYPE,
+                                                AllocationType::kYoung);
   DisallowGarbageCollection no_gc;
   info.set_receiver_or_instance(*receiver_or_instance, SKIP_WRITE_BARRIER);
   info.set_function(*function, SKIP_WRITE_BARRIER);
@@ -3136,6 +3186,16 @@ Handle<Map> Factory::ObjectLiteralMapFromCache(Handle<NativeContext> context,
   return map;
 }
 
+Handle<MegaDomHandler> Factory::NewMegaDomHandler(MaybeObjectHandle accessor,
+                                                  MaybeObjectHandle context) {
+  Handle<Map> map = read_only_roots().mega_dom_handler_map_handle();
+  MegaDomHandler handler = MegaDomHandler::cast(New(map, AllocationType::kOld));
+  DisallowGarbageCollection no_gc;
+  handler.set_accessor(*accessor);
+  handler.set_context(*context);
+  return handle(handler, isolate());
+}
+
 Handle<LoadHandler> Factory::NewLoadHandler(int data_count,
                                             AllocationType allocation) {
   Handle<Map> map;
@@ -3496,7 +3556,8 @@ Handle<JSPromise> Factory::NewJSPromiseWithoutHook() {
 
 Handle<JSPromise> Factory::NewJSPromise() {
   Handle<JSPromise> promise = NewJSPromiseWithoutHook();
-  isolate()->RunPromiseHook(PromiseHookType::kInit, promise, undefined_value());
+  isolate()->RunAllPromiseHooks(PromiseHookType::kInit, promise,
+                                undefined_value());
   return promise;
 }
 
@@ -3538,20 +3599,12 @@ Handle<JSFunction> Factory::JSFunctionBuilder::Build() {
   PrepareMap();
   PrepareFeedbackCell();
 
-  // Determine the associated Code object.
-  Handle<Code> code;
-  const bool have_cached_code =
-      sfi_->TryGetCachedCode(isolate_).ToHandle(&code);
-  if (!have_cached_code) code = handle(sfi_->GetCode(), isolate_);
-
+  Handle<Code> code = handle(sfi_->GetCode(), isolate_);
   Handle<JSFunction> result = BuildRaw(code);
 
-  if (have_cached_code || code->kind() == CodeKind::BASELINE) {
+  if (code->kind() == CodeKind::BASELINE) {
     IsCompiledScope is_compiled_scope(sfi_->is_compiled_scope(isolate_));
     JSFunction::EnsureFeedbackVector(result, &is_compiled_scope);
-    if (FLAG_trace_turbo_nci && have_cached_code) {
-      CompilationCacheCode::TraceHit(sfi_, code);
-    }
   }
 
   Compiler::PostInstantiation(result);
@@ -3583,7 +3636,8 @@ Handle<JSFunction> Factory::JSFunctionBuilder::BuildRaw(Handle<Code> code) {
   function.set_code(*code, kReleaseStore, mode);
   if (function.has_prototype_slot()) {
     function.set_prototype_or_initial_map(
-        ReadOnlyRoots(isolate).the_hole_value(), SKIP_WRITE_BARRIER);
+        ReadOnlyRoots(isolate).the_hole_value(), kReleaseStore,
+        SKIP_WRITE_BARRIER);
   }
 
   // Potentially body initialization.
diff --git a/chromium/v8/src/heap/factory.h b/chromium/v8/src/heap/factory.h
index ebec483de47..7f99c557095 100644
--- a/chromium/v8/src/heap/factory.h
+++ b/chromium/v8/src/heap/factory.h
@@ -131,9 +131,6 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
   MaybeHandle<FixedArray> TryNewFixedArray(
       int length, AllocationType allocation = AllocationType::kYoung);
 
-  // Allocates an uninitialized fixed array. It must be filled by the caller.
-  Handle<FixedArray> NewUninitializedFixedArray(int length);
-
   // Allocates a closure feedback cell array whose feedback cells are
   // initialized with undefined values.
   Handle<ClosureFeedbackCellArray> NewClosureFeedbackCellArray(int num_slots);
@@ -557,7 +554,18 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
 
 #if V8_ENABLE_WEBASSEMBLY
   Handle<WasmTypeInfo> NewWasmTypeInfo(Address type_address,
-                                       Handle<Map> opt_parent);
+                                       Handle<Map> opt_parent,
+                                       int instance_size_bytes);
+  Handle<WasmExportedFunctionData> NewWasmExportedFunctionData(
+      Handle<Code> export_wrapper, Handle<WasmInstanceObject> instance,
+      Address call_target, Handle<Object> ref, int func_index,
+      Address sig_address, int wrapper_budget);
+  // {opt_call_target} is kNullAddress for JavaScript functions, and
+  // non-null for exported Wasm functions.
+  Handle<WasmJSFunctionData> NewWasmJSFunctionData(
+      Address opt_call_target, Handle<JSReceiver> callable, int return_count,
+      int parameter_count, Handle<PodArray<wasm::ValueType>> serialized_sig,
+      Handle<Code> wrapper_code);
 
   Handle<SharedFunctionInfo> NewSharedFunctionInfoForWasmExportedFunction(
       Handle<String> name, Handle<WasmExportedFunctionData> data);
@@ -732,7 +740,8 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
   Handle<LoadHandler> NewLoadHandler(
       int data_count, AllocationType allocation = AllocationType::kOld);
   Handle<StoreHandler> NewStoreHandler(int data_count);
-
+  Handle<MegaDomHandler> NewMegaDomHandler(MaybeObjectHandle accessor,
+                                           MaybeObjectHandle context);
   Handle<RegExpMatchInfo> NewRegExpMatchInfo();
 
   // Creates a new FixedArray that holds the data associated with the
diff --git a/chromium/v8/src/heap/finalization-registry-cleanup-task.cc b/chromium/v8/src/heap/finalization-registry-cleanup-task.cc
index 2acfa31ffba..18222e783d1 100644
--- a/chromium/v8/src/heap/finalization-registry-cleanup-task.cc
+++ b/chromium/v8/src/heap/finalization-registry-cleanup-task.cc
@@ -59,8 +59,21 @@ void FinalizationRegistryCleanupTask::RunInternal() {
       Context::cast(finalization_registry->native_context()), isolate);
   Handle<Object> callback(finalization_registry->cleanup(), isolate);
   v8::Context::Scope context_scope(v8::Utils::ToLocal(context));
-  v8::TryCatch catcher(reinterpret_cast<v8::Isolate*>(isolate));
+  v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(isolate);
+  v8::TryCatch catcher(v8_isolate);
   catcher.SetVerbose(true);
+  std::unique_ptr<MicrotasksScope> microtasks_scope;
+  MicrotaskQueue* microtask_queue =
+      finalization_registry->native_context().microtask_queue();
+  if (!microtask_queue) microtask_queue = isolate->default_microtask_queue();
+  if (microtask_queue &&
+      microtask_queue->microtasks_policy() == v8::MicrotasksPolicy::kScoped) {
+    // InvokeFinalizationRegistryCleanupFromTask will call into V8 API methods,
+    // so we need a valid microtasks scope on the stack to avoid running into
+    // the CallDepthScope check.
+    microtasks_scope.reset(new v8::MicrotasksScope(
+        v8_isolate, microtask_queue, v8::MicrotasksScope::kDoNotRunMicrotasks));
+  }
 
   // Exceptions are reported via the message handler. This is ensured by the
   // verbose TryCatch.
diff --git a/chromium/v8/src/heap/free-list.cc b/chromium/v8/src/heap/free-list.cc
index 80b4a4f01f2..9f13247a2e6 100644
--- a/chromium/v8/src/heap/free-list.cc
+++ b/chromium/v8/src/heap/free-list.cc
@@ -48,7 +48,7 @@ FreeSpace FreeListCategory::SearchForNodeInList(size_t minimum_size,
   for (FreeSpace cur_node = top(); !cur_node.is_null();
        cur_node = cur_node.next()) {
     DCHECK(Page::FromHeapObject(cur_node)->CanAllocate());
-    size_t size = cur_node.size();
+    size_t size = cur_node.size(kRelaxedLoad);
     if (size >= minimum_size) {
       DCHECK_GE(available_, size);
       UpdateCountersAfterAllocation(size);
@@ -91,10 +91,10 @@ void FreeListCategory::RepairFreeList(Heap* heap) {
   FreeSpace n = top();
   while (!n.is_null()) {
     ObjectSlot map_slot = n.map_slot();
-    if (map_slot.contains_value(kNullAddress)) {
-      map_slot.store(free_space_map);
+    if (map_slot.contains_map_value(kNullAddress)) {
+      map_slot.store_map(free_space_map);
     } else {
-      DCHECK(map_slot.contains_value(free_space_map.ptr()));
+      DCHECK(map_slot.contains_map_value(free_space_map.ptr()));
     }
     n = n.next();
   }
@@ -504,12 +504,13 @@ size_t FreeListCategory::SumFreeList() {
   while (!cur.is_null()) {
     // We can't use "cur->map()" here because both cur's map and the
     // root can be null during bootstrapping.
-    DCHECK(cur.map_slot().contains_value(Page::FromHeapObject(cur)
-                                             ->heap()
-                                             ->isolate()
-                                             ->root(RootIndex::kFreeSpaceMap)
-                                             .ptr()));
-    sum += cur.relaxed_read_size();
+    DCHECK(
+        cur.map_slot().contains_map_value(Page::FromHeapObject(cur)
+                                              ->heap()
+                                              ->isolate()
+                                              ->root(RootIndex::kFreeSpaceMap)
+                                              .ptr()));
+    sum += cur.size(kRelaxedLoad);
     cur = cur.next();
   }
   return sum;
diff --git a/chromium/v8/src/heap/gc-tracer.cc b/chromium/v8/src/heap/gc-tracer.cc
index b4f86cc2a15..70f8c276270 100644
--- a/chromium/v8/src/heap/gc-tracer.cc
+++ b/chromium/v8/src/heap/gc-tracer.cc
@@ -13,7 +13,9 @@
 #include "src/heap/heap-inl.h"
 #include "src/heap/incremental-marking.h"
 #include "src/heap/spaces.h"
-#include "src/logging/counters-inl.h"
+#include "src/logging/counters.h"
+#include "src/logging/tracing-flags.h"
+#include "src/tracing/tracing-category-observer.h"
 
 namespace v8 {
 namespace internal {
@@ -28,6 +30,8 @@ static size_t CountTotalHolesSize(Heap* heap) {
   }
   return holes_size;
 }
+
+#ifdef V8_RUNTIME_CALL_STATS
 WorkerThreadRuntimeCallStats* GCTracer::worker_thread_runtime_call_stats() {
   return heap_->isolate()->counters()->worker_thread_runtime_call_stats();
 }
@@ -38,6 +42,7 @@ RuntimeCallCounterId GCTracer::RCSCounterFromScope(Scope::ScopeId id) {
       static_cast<int>(RuntimeCallCounterId::kGC_MC_INCREMENTAL) +
       static_cast<int>(id));
 }
+#endif  // defined(V8_RUNTIME_CALL_STATS)
 
 double GCTracer::MonotonicallyIncreasingTimeInMs() {
   if (V8_UNLIKELY(FLAG_predictable)) {
@@ -61,6 +66,7 @@ GCTracer::Scope::Scope(GCTracer* tracer, ScopeId scope, ThreadKind thread_kind)
   start_time_ = tracer_->MonotonicallyIncreasingTimeInMs();
   if (V8_LIKELY(!TracingFlags::is_runtime_stats_enabled())) return;
 
+#ifdef V8_RUNTIME_CALL_STATS
   if (thread_kind_ == ThreadKind::kMain) {
     DCHECK_EQ(tracer_->heap_->isolate()->thread_id(), ThreadId::Current());
     runtime_stats_ =
@@ -72,6 +78,7 @@ GCTracer::Scope::Scope(GCTracer* tracer, ScopeId scope, ThreadKind thread_kind)
     runtime_stats_ = runtime_call_stats_scope_->Get();
     runtime_stats_->Enter(&timer_, GCTracer::RCSCounterFromScope(scope));
   }
+#endif  // defined(V8_RUNTIME_CALL_STATS)
 }
 
 GCTracer::Scope::~Scope() {
@@ -80,12 +87,23 @@ GCTracer::Scope::~Scope() {
   if (thread_kind_ == ThreadKind::kMain) {
     DCHECK_EQ(tracer_->heap_->isolate()->thread_id(), ThreadId::Current());
     tracer_->AddScopeSample(scope_, duration_ms);
+    if (scope_ == ScopeId::MC_INCREMENTAL ||
+        scope_ == ScopeId::MC_INCREMENTAL_START ||
+        scope_ == MC_INCREMENTAL_FINALIZE) {
+      auto* long_task_stats =
+          tracer_->heap_->isolate()->GetCurrentLongTaskStats();
+      long_task_stats->gc_full_incremental_wall_clock_duration_us +=
+          static_cast<int64_t>(duration_ms *
+                               base::Time::kMicrosecondsPerMillisecond);
+    }
   } else {
     tracer_->AddScopeSampleBackground(scope_, duration_ms);
   }
 
+#ifdef V8_RUNTIME_CALL_STATS
   if (V8_LIKELY(runtime_stats_ == nullptr)) return;
   runtime_stats_->Leave(&timer_);
+#endif  // defined(V8_RUNTIME_CALL_STATS)
 }
 
 const char* GCTracer::Scope::Name(ScopeId id) {
@@ -290,8 +308,10 @@ void GCTracer::StartInSafepoint() {
   current_.start_object_size = heap_->SizeOfObjects();
   current_.start_memory_size = heap_->memory_allocator()->Size();
   current_.start_holes_size = CountTotalHolesSize(heap_);
-  current_.young_object_size =
-      heap_->new_space()->Size() + heap_->new_lo_space()->SizeOfObjects();
+  size_t new_space_size = (heap_->new_space() ? heap_->new_space()->Size() : 0);
+  size_t new_lo_space_size =
+      (heap_->new_lo_space() ? heap_->new_lo_space()->SizeOfObjects() : 0);
+  current_.young_object_size = new_space_size + new_lo_space_size;
 }
 
 void GCTracer::ResetIncrementalMarkingCounters() {
@@ -333,6 +353,9 @@ void GCTracer::Stop(GarbageCollector collector) {
   AddAllocation(current_.end_time);
 
   double duration = current_.end_time - current_.start_time;
+  int64_t duration_us =
+      static_cast<int64_t>(duration * base::Time::kMicrosecondsPerMillisecond);
+  auto* long_task_stats = heap_->isolate()->GetCurrentLongTaskStats();
 
   switch (current_.type) {
     case Event::SCAVENGER:
@@ -342,6 +365,7 @@ void GCTracer::Stop(GarbageCollector collector) {
       recorded_minor_gcs_survived_.Push(
           MakeBytesAndDuration(current_.survived_young_object_size, duration));
       FetchBackgroundMinorGCCounters();
+      long_task_stats->gc_young_wall_clock_duration_us += duration_us;
       break;
     case Event::INCREMENTAL_MARK_COMPACTOR:
       current_.incremental_marking_bytes = incremental_marking_bytes_;
@@ -361,6 +385,7 @@ void GCTracer::Stop(GarbageCollector collector) {
       ResetIncrementalMarkingCounters();
       combined_mark_compact_speed_cache_ = 0.0;
       FetchBackgroundMarkCompactCounters();
+      long_task_stats->gc_full_atomic_wall_clock_duration_us += duration_us;
       break;
     case Event::MARK_COMPACTOR:
       DCHECK_EQ(0u, current_.incremental_marking_bytes);
@@ -373,6 +398,7 @@ void GCTracer::Stop(GarbageCollector collector) {
       ResetIncrementalMarkingCounters();
       combined_mark_compact_speed_cache_ = 0.0;
       FetchBackgroundMarkCompactCounters();
+      long_task_stats->gc_full_atomic_wall_clock_duration_us += duration_us;
       break;
     case Event::START:
       UNREACHABLE();
diff --git a/chromium/v8/src/heap/gc-tracer.h b/chromium/v8/src/heap/gc-tracer.h
index 011889ba66e..3a665726ca7 100644
--- a/chromium/v8/src/heap/gc-tracer.h
+++ b/chromium/v8/src/heap/gc-tracer.h
@@ -113,9 +113,11 @@ class V8_EXPORT_PRIVATE GCTracer {
     ScopeId scope_;
     ThreadKind thread_kind_;
     double start_time_;
+#ifdef V8_RUNTIME_CALL_STATS
     RuntimeCallTimer timer_;
     RuntimeCallStats* runtime_stats_ = nullptr;
     base::Optional<WorkerThreadRuntimeCallStatsScope> runtime_call_stats_scope_;
+#endif  // defined(V8_RUNTIME_CALL_STATS)
   };
 
   class Event {
@@ -195,7 +197,9 @@ class V8_EXPORT_PRIVATE GCTracer {
   static double CombineSpeedsInBytesPerMillisecond(double default_speed,
                                                    double optional_speed);
 
+#ifdef V8_RUNTIME_CALL_STATS
   static RuntimeCallCounterId RCSCounterFromScope(Scope::ScopeId id);
+#endif  // defined(V8_RUNTIME_CALL_STATS)
 
   explicit GCTracer(Heap* heap);
 
@@ -335,7 +339,9 @@ class V8_EXPORT_PRIVATE GCTracer {
   double AverageTimeToIncrementalMarkingTask() const;
   void RecordTimeToIncrementalMarkingTask(double time_to_task);
 
+#ifdef V8_RUNTIME_CALL_STATS
   WorkerThreadRuntimeCallStats* worker_thread_runtime_call_stats();
+#endif  // defined(V8_RUNTIME_CALL_STATS)
 
   CollectionEpoch CurrentEpoch(Scope::ScopeId id);
 
diff --git a/chromium/v8/src/heap/heap-inl.h b/chromium/v8/src/heap/heap-inl.h
index 8372dd518d7..8c2649e0ef8 100644
--- a/chromium/v8/src/heap/heap-inl.h
+++ b/chromium/v8/src/heap/heap-inl.h
@@ -8,22 +8,17 @@
 #include <cmath>
 
 // Clients of this interface shouldn't depend on lots of heap internals.
-// Do not include anything from src/heap other than src/heap/heap.h and its
-// write barrier here!
+// Avoid including anything but `heap.h` from `src/heap` where possible.
 #include "src/base/atomic-utils.h"
 #include "src/base/atomicops.h"
 #include "src/base/platform/platform.h"
+#include "src/base/sanitizer/msan.h"
 #include "src/common/assert-scope.h"
-#include "src/heap/heap-write-barrier.h"
-#include "src/heap/heap.h"
-#include "src/heap/third-party/heap-api.h"
-#include "src/objects/feedback-vector.h"
-
-// TODO(gc): There is one more include to remove in order to no longer
-// leak heap internals to users of this interface!
 #include "src/execution/isolate-data.h"
 #include "src/execution/isolate.h"
 #include "src/heap/code-object-registry.h"
+#include "src/heap/heap-write-barrier.h"
+#include "src/heap/heap.h"
 #include "src/heap/large-spaces.h"
 #include "src/heap/memory-allocator.h"
 #include "src/heap/memory-chunk.h"
@@ -31,11 +26,13 @@
 #include "src/heap/paged-spaces-inl.h"
 #include "src/heap/read-only-spaces.h"
 #include "src/heap/spaces-inl.h"
+#include "src/heap/third-party/heap-api.h"
 #include "src/objects/allocation-site-inl.h"
 #include "src/objects/api-callbacks-inl.h"
 #include "src/objects/cell-inl.h"
 #include "src/objects/descriptor-array.h"
 #include "src/objects/feedback-cell-inl.h"
+#include "src/objects/feedback-vector.h"
 #include "src/objects/literal-objects-inl.h"
 #include "src/objects/objects-inl.h"
 #include "src/objects/oddball.h"
@@ -45,7 +42,6 @@
 #include "src/objects/slots-inl.h"
 #include "src/objects/struct-inl.h"
 #include "src/profiler/heap-profiler.h"
-#include "src/sanitizer/msan.h"
 #include "src/strings/string-hasher.h"
 #include "src/zone/zone-list-inl.h"
 
@@ -162,19 +158,12 @@ Address* Heap::OldSpaceAllocationLimitAddress() {
   return old_space_->allocation_limit_address();
 }
 
-void Heap::UpdateNewSpaceAllocationCounter() {
-  new_space_allocation_counter_ = NewSpaceAllocationCounter();
-}
-
-size_t Heap::NewSpaceAllocationCounter() {
-  return new_space_allocation_counter_ + new_space()->AllocatedSinceLastGC();
-}
-
-inline const base::AddressRegion& Heap::code_range() {
+inline const base::AddressRegion& Heap::code_region() {
 #ifdef V8_ENABLE_THIRD_PARTY_HEAP
   return tp_heap_->GetCodeRange();
 #else
-  return memory_allocator_->code_range();
+  static constexpr base::AddressRegion kEmptyRegion;
+  return code_range_ ? code_range_->reservation()->region() : kEmptyRegion;
 #endif
 }
 
@@ -189,7 +178,8 @@ AllocationResult Heap::AllocateRaw(int size_in_bytes, AllocationType type,
 #ifdef V8_ENABLE_ALLOCATION_TIMEOUT
   if (FLAG_random_gc_interval > 0 || FLAG_gc_interval >= 0) {
     if (!always_allocate() && Heap::allocation_timeout_-- <= 0) {
-      return AllocationResult::Retry();
+      AllocationSpace space = FLAG_single_generation ? OLD_SPACE : NEW_SPACE;
+      return AllocationResult::Retry(space);
     }
   }
 #endif
@@ -197,6 +187,10 @@ AllocationResult Heap::AllocateRaw(int size_in_bytes, AllocationType type,
   IncrementObjectCounters();
 #endif
 
+  if (CanSafepoint()) {
+    main_thread_local_heap()->Safepoint();
+  }
+
   size_t large_object_threshold = MaxRegularHeapObjectSize(type);
   bool large_object =
       static_cast<size_t>(size_in_bytes) > large_object_threshold;
@@ -245,6 +239,12 @@ AllocationResult Heap::AllocateRaw(int size_in_bytes, AllocationType type,
       DCHECK(CanAllocateInReadOnlySpace());
       DCHECK_EQ(AllocationOrigin::kRuntime, origin);
       allocation = read_only_space_->AllocateRaw(size_in_bytes, alignment);
+    } else if (AllocationType::kSharedOld == type) {
+      allocation =
+          shared_old_allocator_->AllocateRaw(size_in_bytes, alignment, origin);
+    } else if (AllocationType::kSharedMap == type) {
+      allocation =
+          shared_map_allocator_->AllocateRaw(size_in_bytes, alignment, origin);
     } else {
       UNREACHABLE();
     }
@@ -285,10 +285,9 @@ HeapObject Heap::AllocateRawWith(int size, AllocationType allocation,
   DCHECK(AllowHeapAllocation::IsAllowed());
   DCHECK_EQ(gc_state(), NOT_IN_GC);
   Heap* heap = isolate()->heap();
-  if (!V8_ENABLE_THIRD_PARTY_HEAP_BOOL &&
-      allocation == AllocationType::kYoung &&
+  if (allocation == AllocationType::kYoung &&
       alignment == AllocationAlignment::kWordAligned &&
-      size <= MaxRegularHeapObjectSize(allocation)) {
+      size <= MaxRegularHeapObjectSize(allocation) && !FLAG_single_generation) {
     Address* top = heap->NewSpaceAllocationTopAddress();
     Address* limit = heap->NewSpaceAllocationLimitAddress();
     if ((*limit - *top >= static_cast<unsigned>(size)) &&
@@ -383,17 +382,21 @@ void Heap::RegisterExternalString(String string) {
 
 void Heap::FinalizeExternalString(String string) {
   DCHECK(string.IsExternalString());
-  Page* page = Page::FromHeapObject(string);
   ExternalString ext_string = ExternalString::cast(string);
 
-  page->DecrementExternalBackingStoreBytes(
-      ExternalBackingStoreType::kExternalString,
-      ext_string.ExternalPayloadSize());
+  if (!FLAG_enable_third_party_heap) {
+    Page* page = Page::FromHeapObject(string);
+    page->DecrementExternalBackingStoreBytes(
+        ExternalBackingStoreType::kExternalString,
+        ext_string.ExternalPayloadSize());
+  }
 
   ext_string.DisposeResource(isolate());
 }
 
-Address Heap::NewSpaceTop() { return new_space_->top(); }
+Address Heap::NewSpaceTop() {
+  return new_space_ ? new_space_->top() : kNullAddress;
+}
 
 bool Heap::InYoungGeneration(Object object) {
   DCHECK(!HasWeakHeapObjectTag(object));
@@ -458,7 +461,12 @@ bool Heap::InToPage(HeapObject heap_object) {
   return BasicMemoryChunk::FromHeapObject(heap_object)->IsToPage();
 }
 
-bool Heap::InOldSpace(Object object) { return old_space_->Contains(object); }
+bool Heap::InOldSpace(Object object) {
+  if (V8_ENABLE_THIRD_PARTY_HEAP_BOOL)
+    return object.IsHeapObject() &&
+           third_party_heap::Heap::InOldSpace(object.ptr());
+  return old_space_->Contains(object);
+}
 
 // static
 Heap* Heap::FromWritableHeapObject(HeapObject obj) {
@@ -502,7 +510,7 @@ AllocationMemento Heap::FindAllocationMemento(Map map, HeapObject object) {
   // below (memento_address == top) ensures that this is safe. Mark the word as
   // initialized to silence MemorySanitizer warnings.
   MSAN_MEMORY_IS_INITIALIZED(candidate_map_slot.address(), kTaggedSize);
-  if (!candidate_map_slot.contains_value(
+  if (!candidate_map_slot.contains_map_value(
           ReadOnlyRoots(this).allocation_memento_map().ptr())) {
     return AllocationMemento();
   }
@@ -577,18 +585,23 @@ void Heap::UpdateAllocationSite(Map map, HeapObject object,
 bool Heap::IsPendingAllocation(HeapObject object) {
   // TODO(ulan): Optimize this function to perform 3 loads at most.
   Address addr = object.address();
-  Address top = new_space_->original_top_acquire();
-  Address limit = new_space_->original_limit_relaxed();
-  if (top <= addr && addr < limit) return true;
+  Address top, limit;
+
+  if (new_space_) {
+    top = new_space_->original_top_acquire();
+    limit = new_space_->original_limit_relaxed();
+    if (top && top <= addr && addr < limit) return true;
+  }
+
   PagedSpaceIterator spaces(this);
   for (PagedSpace* space = spaces.Next(); space != nullptr;
        space = spaces.Next()) {
     top = space->original_top_acquire();
     limit = space->original_limit_relaxed();
-    if (top <= addr && addr < limit) return true;
+    if (top && top <= addr && addr < limit) return true;
   }
   if (addr == lo_space_->pending_object()) return true;
-  if (addr == new_lo_space_->pending_object()) return true;
+  if (new_lo_space_ && addr == new_lo_space_->pending_object()) return true;
   if (addr == code_lo_space_->pending_object()) return true;
   return false;
 }
@@ -644,8 +657,8 @@ int Heap::NextDebuggingId() {
 }
 
 int Heap::GetNextTemplateSerialNumber() {
-  int next_serial_number = next_template_serial_number().value() + 1;
-  set_next_template_serial_number(Smi::FromInt(next_serial_number));
+  int next_serial_number = next_template_serial_number().value();
+  set_next_template_serial_number(Smi::FromInt(next_serial_number + 1));
   return next_serial_number;
 }
 
diff --git a/chromium/v8/src/heap/heap-write-barrier.cc b/chromium/v8/src/heap/heap-write-barrier.cc
index 63949de2433..0030615bab4 100644
--- a/chromium/v8/src/heap/heap-write-barrier.cc
+++ b/chromium/v8/src/heap/heap-write-barrier.cc
@@ -68,7 +68,16 @@ void WriteBarrier::MarkingSlow(Heap* heap, DescriptorArray descriptor_array,
 int WriteBarrier::MarkingFromCode(Address raw_host, Address raw_slot) {
   HeapObject host = HeapObject::cast(Object(raw_host));
   MaybeObjectSlot slot(raw_slot);
-  WriteBarrier::Marking(host, slot, *slot);
+  Address value = (*slot).ptr();
+#ifdef V8_MAP_PACKING
+  if (slot.address() == host.address()) {
+    // Clear metadata bits and fix object tag.
+    value = (value & ~Internals::kMapWordMetadataMask &
+             ~Internals::kMapWordXorMask) |
+            (uint64_t)kHeapObjectTag;
+  }
+#endif
+  WriteBarrier::Marking(host, slot, MaybeObject(value));
   // Called by RecordWriteCodeStubAssembler, which doesnt accept void type
   return 0;
 }
diff --git a/chromium/v8/src/heap/heap.cc b/chromium/v8/src/heap/heap.cc
index 8b8c30a1b0b..9da67b75344 100644
--- a/chromium/v8/src/heap/heap.cc
+++ b/chromium/v8/src/heap/heap.cc
@@ -14,6 +14,7 @@
 #include "src/api/api-inl.h"
 #include "src/base/bits.h"
 #include "src/base/flags.h"
+#include "src/base/logging.h"
 #include "src/base/once.h"
 #include "src/base/platform/mutex.h"
 #include "src/base/utils/random-number-generator.h"
@@ -35,6 +36,7 @@
 #include "src/heap/barrier.h"
 #include "src/heap/base/stack.h"
 #include "src/heap/code-object-registry.h"
+#include "src/heap/code-range.h"
 #include "src/heap/code-stats.h"
 #include "src/heap/collection-barrier.h"
 #include "src/heap/combined-heap.h"
@@ -323,7 +325,9 @@ size_t Heap::SemiSpaceSizeFromYoungGenerationSize(
 size_t Heap::Capacity() {
   if (!HasBeenSetUp()) return 0;
 
-  return new_space_->Capacity() + OldGenerationCapacity();
+  if (FLAG_enable_third_party_heap) return tp_heap_->Capacity();
+
+  return NewSpaceCapacity() + OldGenerationCapacity();
 }
 
 size_t Heap::OldGenerationCapacity() {
@@ -358,7 +362,10 @@ size_t Heap::CommittedMemoryOfUnmapper() {
 size_t Heap::CommittedMemory() {
   if (!HasBeenSetUp()) return 0;
 
-  return new_space_->CommittedMemory() + new_lo_space_->Size() +
+  size_t new_space_committed = new_space_ ? new_space_->CommittedMemory() : 0;
+  size_t new_lo_space_committed = new_lo_space_ ? new_lo_space_->Size() : 0;
+
+  return new_space_committed + new_lo_space_committed +
          CommittedOldGenerationMemory();
 }
 
@@ -421,14 +428,17 @@ bool Heap::CanExpandOldGenerationBackground(LocalHeap* local_heap,
 }
 
 bool Heap::CanPromoteYoungAndExpandOldGeneration(size_t size) {
+  size_t new_space_capacity = NewSpaceCapacity();
+  size_t new_lo_space_capacity = new_lo_space_ ? new_lo_space_->Size() : 0;
+
   // Over-estimate the new space size using capacity to allow some slack.
-  return CanExpandOldGeneration(size + new_space_->Capacity() +
-                                new_lo_space_->Size());
+  return CanExpandOldGeneration(size + new_space_capacity +
+                                new_lo_space_capacity);
 }
 
 bool Heap::HasBeenSetUp() const {
-  // We will always have a new space when the heap is set up.
-  return new_space_ != nullptr;
+  // We will always have an old space when the heap is set up.
+  return old_space_ != nullptr;
 }
 
 GarbageCollector Heap::SelectGarbageCollector(AllocationSpace space,
@@ -440,7 +450,7 @@ GarbageCollector Heap::SelectGarbageCollector(AllocationSpace space,
     return MARK_COMPACTOR;
   }
 
-  if (FLAG_gc_global || ShouldStressCompaction()) {
+  if (FLAG_gc_global || ShouldStressCompaction() || FLAG_single_generation) {
     *reason = "GC in old space forced by flags";
     return MARK_COMPACTOR;
   }
@@ -485,7 +495,7 @@ void Heap::PrintShortHeapStatistics() {
                "New space,              used: %6zu KB"
                ", available: %6zu KB"
                ", committed: %6zu KB\n",
-               new_space_->Size() / KB, new_space_->Available() / KB,
+               NewSpaceSize() / KB, new_space_->Available() / KB,
                new_space_->CommittedMemory() / KB);
   PrintIsolate(isolate_,
                "New large object space, used: %6zu KB"
@@ -788,6 +798,58 @@ void Heap::PrintRetainingPath(HeapObject target, RetainingPathOption option) {
   PrintF("-------------------------------------------------\n");
 }
 
+void UpdateRetainersMapAfterScavenge(
+    std::unordered_map<HeapObject, HeapObject, Object::Hasher>* map) {
+  std::unordered_map<HeapObject, HeapObject, Object::Hasher> updated_map;
+
+  for (auto pair : *map) {
+    HeapObject object = pair.first;
+    HeapObject retainer = pair.second;
+
+    if (Heap::InFromPage(object)) {
+      MapWord map_word = object.map_word(kRelaxedLoad);
+      if (!map_word.IsForwardingAddress()) continue;
+      object = map_word.ToForwardingAddress();
+    }
+
+    if (Heap::InFromPage(retainer)) {
+      MapWord map_word = retainer.map_word(kRelaxedLoad);
+      if (!map_word.IsForwardingAddress()) continue;
+      retainer = map_word.ToForwardingAddress();
+    }
+
+    updated_map[object] = retainer;
+  }
+
+  *map = std::move(updated_map);
+}
+
+void Heap::UpdateRetainersAfterScavenge() {
+  if (!incremental_marking()->IsMarking()) return;
+
+  // This isn't supported for Minor MC.
+  DCHECK(!FLAG_minor_mc);
+
+  UpdateRetainersMapAfterScavenge(&retainer_);
+  UpdateRetainersMapAfterScavenge(&ephemeron_retainer_);
+
+  std::unordered_map<HeapObject, Root, Object::Hasher> updated_retaining_root;
+
+  for (auto pair : retaining_root_) {
+    HeapObject object = pair.first;
+
+    if (Heap::InFromPage(object)) {
+      MapWord map_word = object.map_word(kRelaxedLoad);
+      if (!map_word.IsForwardingAddress()) continue;
+      object = map_word.ToForwardingAddress();
+    }
+
+    updated_retaining_root[object] = pair.second;
+  }
+
+  retaining_root_ = std::move(updated_retaining_root);
+}
+
 void Heap::AddRetainer(HeapObject retainer, HeapObject object) {
   if (retainer_.count(object)) return;
   retainer_[object] = retainer;
@@ -850,7 +912,7 @@ void Heap::GarbageCollectionPrologue() {
   if (FLAG_gc_verbose) Print();
 #endif  // DEBUG
 
-  if (new_space_->IsAtMaximumCapacity()) {
+  if (new_space_ && new_space_->IsAtMaximumCapacity()) {
     maximum_size_scavenges_++;
   } else {
     maximum_size_scavenges_ = 0;
@@ -867,9 +929,20 @@ void Heap::GarbageCollectionPrologueInSafepoint() {
   TRACE_GC(tracer(), GCTracer::Scope::HEAP_PROLOGUE_SAFEPOINT);
   gc_count_++;
 
-  UpdateNewSpaceAllocationCounter();
-  CheckNewSpaceExpansionCriteria();
-  new_space_->ResetParkedAllocationBuffers();
+  if (new_space_) {
+    UpdateNewSpaceAllocationCounter();
+    CheckNewSpaceExpansionCriteria();
+    new_space_->ResetParkedAllocationBuffers();
+  }
+}
+
+void Heap::UpdateNewSpaceAllocationCounter() {
+  new_space_allocation_counter_ = NewSpaceAllocationCounter();
+}
+
+size_t Heap::NewSpaceAllocationCounter() {
+  return new_space_allocation_counter_ +
+         (new_space_ ? new_space()->AllocatedSinceLastGC() : 0);
 }
 
 size_t Heap::SizeOfObjects() {
@@ -894,7 +967,7 @@ void Heap::MergeAllocationSitePretenuringFeedback(
   AllocationSite site;
   for (auto& site_and_count : local_pretenuring_feedback) {
     site = site_and_count.first;
-    MapWord map_word = site_and_count.first.map_word();
+    MapWord map_word = site_and_count.first.map_word(kRelaxedLoad);
     if (map_word.IsForwardingAddress()) {
       site = AllocationSite::cast(map_word.ToForwardingAddress());
     }
@@ -944,14 +1017,15 @@ void Heap::RemoveAllocationObserversFromAllSpaces(
 }
 
 void Heap::PublishPendingAllocations() {
-  new_space_->MarkLabStartInitialized();
+  if (FLAG_enable_third_party_heap) return;
+  if (new_space_) new_space_->MarkLabStartInitialized();
   PagedSpaceIterator spaces(this);
   for (PagedSpace* space = spaces.Next(); space != nullptr;
        space = spaces.Next()) {
     space->MoveOriginalTopForward();
   }
   lo_space_->ResetPendingObject();
-  new_lo_space_->ResetPendingObject();
+  if (new_lo_space_) new_lo_space_->ResetPendingObject();
   code_lo_space_->ResetPendingObject();
 }
 
@@ -981,6 +1055,12 @@ inline bool MakePretenureDecision(
   return false;
 }
 
+// Clear feedback calculation fields until the next gc.
+inline void ResetPretenuringFeedback(AllocationSite site) {
+  site.set_memento_found_count(0);
+  site.set_memento_create_count(0);
+}
+
 inline bool DigestPretenuringFeedback(Isolate* isolate, AllocationSite site,
                                       bool maximum_size_scavenge) {
   bool deopt = false;
@@ -1008,11 +1088,34 @@ inline bool DigestPretenuringFeedback(Isolate* isolate, AllocationSite site,
                  site.PretenureDecisionName(site.pretenure_decision()));
   }
 
-  // Clear feedback calculation fields until the next gc.
-  site.set_memento_found_count(0);
-  site.set_memento_create_count(0);
+  ResetPretenuringFeedback(site);
   return deopt;
 }
+
+bool PretenureAllocationSiteManually(Isolate* isolate, AllocationSite site) {
+  AllocationSite::PretenureDecision current_decision =
+      site.pretenure_decision();
+  bool deopt = true;
+  if (current_decision == AllocationSite::kUndecided ||
+      current_decision == AllocationSite::kMaybeTenure) {
+    site.set_deopt_dependent_code(true);
+    site.set_pretenure_decision(AllocationSite::kTenure);
+  } else {
+    deopt = false;
+  }
+  if (FLAG_trace_pretenuring_statistics) {
+    PrintIsolate(isolate,
+                 "pretenuring manually requested: AllocationSite(%p): "
+                 "%s => %s\n",
+                 reinterpret_cast<void*>(site.ptr()),
+                 site.PretenureDecisionName(current_decision),
+                 site.PretenureDecisionName(site.pretenure_decision()));
+  }
+
+  ResetPretenuringFeedback(site);
+  return deopt;
+}
+
 }  // namespace
 
 void Heap::RemoveAllocationSitePretenuringFeedback(AllocationSite site) {
@@ -1020,7 +1123,8 @@ void Heap::RemoveAllocationSitePretenuringFeedback(AllocationSite site) {
 }
 
 bool Heap::DeoptMaybeTenuredAllocationSites() {
-  return new_space_->IsAtMaximumCapacity() && maximum_size_scavenges_ == 0;
+  return new_space_ && new_space_->IsAtMaximumCapacity() &&
+         maximum_size_scavenges_ == 0;
 }
 
 void Heap::ProcessPretenuringFeedback() {
@@ -1060,7 +1164,18 @@ void Heap::ProcessPretenuringFeedback() {
       }
     }
 
-    // Step 2: Deopt maybe tenured allocation sites if necessary.
+    // Step 2: Pretenure allocation sites for manual requests.
+    if (allocation_sites_to_pretenure_) {
+      while (!allocation_sites_to_pretenure_->empty()) {
+        auto site = allocation_sites_to_pretenure_->Pop();
+        if (PretenureAllocationSiteManually(isolate_, site)) {
+          trigger_deoptimization = true;
+        }
+      }
+      allocation_sites_to_pretenure_.reset();
+    }
+
+    // Step 3: Deopt maybe tenured allocation sites if necessary.
     bool deopt_maybe_tenured = DeoptMaybeTenuredAllocationSites();
     if (deopt_maybe_tenured) {
       ForeachAllocationSite(
@@ -1096,6 +1211,14 @@ void Heap::ProcessPretenuringFeedback() {
   }
 }
 
+void Heap::PretenureAllocationSiteOnNextCollection(AllocationSite site) {
+  if (!allocation_sites_to_pretenure_) {
+    allocation_sites_to_pretenure_.reset(
+        new GlobalHandleVector<AllocationSite>(this));
+  }
+  allocation_sites_to_pretenure_->Push(site);
+}
+
 void Heap::InvalidateCodeDeoptimizationData(Code code) {
   CodePageMemoryModificationScope modification_scope(code);
   code.set_deoptimization_data(ReadOnlyRoots(this).empty_fixed_array());
@@ -1145,7 +1268,10 @@ void Heap::GarbageCollectionEpilogueInSafepoint(GarbageCollector collector) {
   UPDATE_COUNTERS_FOR_SPACE(space)                         \
   UPDATE_FRAGMENTATION_FOR_SPACE(space)
 
-  UPDATE_COUNTERS_FOR_SPACE(new_space)
+  if (new_space()) {
+    UPDATE_COUNTERS_FOR_SPACE(new_space)
+  }
+
   UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(old_space)
   UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(code_space)
   UPDATE_COUNTERS_AND_FRAGMENTATION_FOR_SPACE(map_space)
@@ -1175,16 +1301,14 @@ void Heap::GarbageCollectionEpilogueInSafepoint(GarbageCollector collector) {
     ZapFromSpace();
   }
 
-  {
+  if (new_space()) {
     TRACE_GC(tracer(), GCTracer::Scope::HEAP_EPILOGUE_REDUCE_NEW_SPACE);
     ReduceNewSpaceSize();
   }
 
   // Set main thread state back to Running from CollectionRequested.
-  LocalHeap* main_thread_local_heap = isolate()->main_thread_local_heap();
-
   LocalHeap::ThreadState old_state =
-      main_thread_local_heap->state_.exchange(LocalHeap::kRunning);
+      main_thread_local_heap()->state_.exchange(LocalHeap::kRunning);
 
   CHECK(old_state == LocalHeap::kRunning ||
         old_state == LocalHeap::kCollectionRequested);
@@ -1404,8 +1528,7 @@ void Heap::CollectAllAvailableGarbage(GarbageCollectionReason gc_reason) {
   if (gc_reason == GarbageCollectionReason::kLastResort) {
     InvokeNearHeapLimitCallback();
   }
-  RuntimeCallTimerScope runtime_timer(
-      isolate(), RuntimeCallCounterId::kGC_Custom_AllAvailableGarbage);
+  RCS_SCOPE(isolate(), RuntimeCallCounterId::kGC_Custom_AllAvailableGarbage);
 
   // The optimizing compiler may be unnecessarily holding on to memory.
   isolate()->AbortConcurrentOptimization(BlockingBehavior::kDontBlock);
@@ -1512,6 +1635,7 @@ void Heap::EnsureFillerObjectAtTop() {
   // evacuation of a non-full new space (or if we are on the last page) there
   // may be uninitialized memory behind top. We fill the remainder of the page
   // with a filler.
+  if (!new_space_) return;
   Address to_top = new_space_->top();
   Page* page = Page::FromAddress(to_top - kTaggedSize);
   if (page->Contains(to_top)) {
@@ -1593,6 +1717,16 @@ bool Heap::CollectGarbage(AllocationSpace space,
 
   if (collector == MARK_COMPACTOR) {
     committed_memory_before = CommittedOldGenerationMemory();
+    if (cpp_heap()) {
+      // CppHeap needs a stack marker at the top of all entry points to allow
+      // deterministic passes over the stack. E.g., a verifier that should only
+      // find a subset of references of the marker.
+      //
+      // TODO(chromium:1056170): Consider adding a component that keeps track
+      // of relevant GC stack regions where interesting pointers can be found.
+      static_cast<v8::internal::CppHeap*>(cpp_heap())
+          ->SetStackEndOfCurrentGC(v8::base::Stack::GetCurrentStackPosition());
+    }
   }
 
   {
@@ -1800,7 +1934,7 @@ void Heap::StartIncrementalMarkingIfAllocationLimitIsReached(
     } else if (reached_limit == IncrementalMarkingLimit::kHardLimit) {
       StartIncrementalMarking(
           gc_flags,
-          OldGenerationSpaceAvailable() <= new_space_->Capacity()
+          OldGenerationSpaceAvailable() <= NewSpaceCapacity()
               ? GarbageCollectionReason::kAllocationLimit
               : GarbageCollectionReason::kGlobalAllocationLimit,
           gc_callback_flags);
@@ -1816,7 +1950,7 @@ void Heap::StartIncrementalMarkingIfAllocationLimitIsReachedBackground() {
 
   const size_t old_generation_space_available = OldGenerationSpaceAvailable();
 
-  if (old_generation_space_available < new_space_->Capacity()) {
+  if (old_generation_space_available < NewSpaceCapacity()) {
     incremental_marking()->incremental_marking_job()->ScheduleTask(this);
   }
 }
@@ -1943,6 +2077,7 @@ static void VerifyStringTable(Isolate* isolate) {
 #endif  // VERIFY_HEAP
 
 void Heap::EnsureFromSpaceIsCommitted() {
+  if (!new_space_) return;
   if (new_space_->CommitFromSpaceIfNeeded()) return;
 
   // Committing memory to from space failed.
@@ -2024,6 +2159,9 @@ size_t Heap::PerformGarbageCollection(
 
   SafepointScope safepoint_scope(this);
 
+  // Shared isolates cannot have any clients when running GC at the moment.
+  DCHECK_IMPLIES(IsShared(), !isolate()->HasClientIsolates());
+
   collection_barrier_->StopTimeToCollectionTimer();
 
 #ifdef VERIFY_HEAP
@@ -2039,7 +2177,7 @@ size_t Heap::PerformGarbageCollection(
   EnsureFromSpaceIsCommitted();
 
   size_t start_young_generation_size =
-      Heap::new_space()->Size() + new_lo_space()->SizeOfObjects();
+      NewSpaceSize() + (new_lo_space() ? new_lo_space()->SizeOfObjects() : 0);
 
   switch (collector) {
     case MARK_COMPACTOR:
@@ -2173,7 +2311,7 @@ void Heap::RecomputeLimits(GarbageCollector collector) {
   }
 
   size_t old_gen_size = OldGenerationSizeOfObjects();
-  size_t new_space_capacity = new_space()->Capacity();
+  size_t new_space_capacity = NewSpaceCapacity();
   HeapGrowingMode mode = CurrentHeapGrowingMode();
 
   if (collector == MARK_COMPACTOR) {
@@ -2219,8 +2357,7 @@ void Heap::RecomputeLimits(GarbageCollector collector) {
 }
 
 void Heap::CallGCPrologueCallbacks(GCType gc_type, GCCallbackFlags flags) {
-  RuntimeCallTimerScope runtime_timer(
-      isolate(), RuntimeCallCounterId::kGCPrologueCallback);
+  RCS_SCOPE(isolate(), RuntimeCallCounterId::kGCPrologueCallback);
   for (const GCCallbackTuple& info : gc_prologue_callbacks_) {
     if (gc_type & info.gc_type) {
       v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(this->isolate());
@@ -2230,8 +2367,7 @@ void Heap::CallGCPrologueCallbacks(GCType gc_type, GCCallbackFlags flags) {
 }
 
 void Heap::CallGCEpilogueCallbacks(GCType gc_type, GCCallbackFlags flags) {
-  RuntimeCallTimerScope runtime_timer(
-      isolate(), RuntimeCallCounterId::kGCEpilogueCallback);
+  RCS_SCOPE(isolate(), RuntimeCallCounterId::kGCEpilogueCallback);
   for (const GCCallbackTuple& info : gc_epilogue_callbacks_) {
     if (gc_type & info.gc_type) {
       v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(this->isolate());
@@ -2280,7 +2416,7 @@ void Heap::MarkCompact() {
 
 void Heap::MinorMarkCompact() {
 #ifdef ENABLE_MINOR_MC
-  DCHECK(FLAG_minor_mc);
+  DCHECK(FLAG_minor_mc && !FLAG_single_generation);
 
   PauseAllocationObserversScope pause_observers(this);
   SetGCState(MINOR_MARK_COMPACT);
@@ -2387,6 +2523,8 @@ void Heap::EvacuateYoungGeneration() {
 }
 
 void Heap::Scavenge() {
+  DCHECK(!FLAG_single_generation);
+
   if (fast_promotion_mode_ && CanPromoteYoungAndExpandOldGeneration(0)) {
     tracer()->NotifyYoungGenerationHandling(
         YoungGenerationHandling::kFastPromotionDuringScavenge);
@@ -2435,12 +2573,15 @@ void Heap::Scavenge() {
 }
 
 void Heap::ComputeFastPromotionMode() {
+  if (!new_space_) return;
+
   const size_t survived_in_new_space =
-      survived_last_scavenge_ * 100 / new_space_->Capacity();
+      survived_last_scavenge_ * 100 / NewSpaceCapacity();
   fast_promotion_mode_ =
       !FLAG_optimize_for_size && FLAG_fast_promotion_new_space &&
       !ShouldReduceMemory() && new_space_->IsAtMaximumCapacity() &&
       survived_in_new_space >= kMinPromotedPercentForFastPromotionMode;
+
   if (FLAG_trace_gc_verbose && !FLAG_trace_gc_ignore_scavenger) {
     PrintIsolate(isolate(), "Fast promotion mode: %s survival rate: %zu%%\n",
                  fast_promotion_mode_ ? "true" : "false",
@@ -2488,6 +2629,8 @@ bool Heap::ExternalStringTable::Contains(String string) {
 void Heap::UpdateExternalString(String string, size_t old_payload,
                                 size_t new_payload) {
   DCHECK(string.IsExternalString());
+  if (FLAG_enable_third_party_heap) return;
+
   Page* page = Page::FromHeapObject(string);
 
   if (old_payload > new_payload) {
@@ -2502,7 +2645,7 @@ void Heap::UpdateExternalString(String string, size_t old_payload,
 String Heap::UpdateYoungReferenceInExternalStringTableEntry(Heap* heap,
                                                             FullObjectSlot p) {
   HeapObject obj = HeapObject::cast(*p);
-  MapWord first_word = obj.map_word();
+  MapWord first_word = obj.map_word(kRelaxedLoad);
 
   String new_string;
 
@@ -2863,7 +3006,7 @@ HeapObject Heap::AlignWithFiller(ReadOnlyRoots roots, HeapObject object,
 
 void* Heap::AllocateExternalBackingStore(
     const std::function<void*(size_t)>& allocate, size_t byte_length) {
-  if (!always_allocate()) {
+  if (!always_allocate() && new_space()) {
     size_t new_space_backing_store_bytes =
         new_space()->ExternalBackingStoreBytes();
     if (new_space_backing_store_bytes >= 2 * kMaxSemiSpaceSize &&
@@ -2874,8 +3017,6 @@ void* Heap::AllocateExternalBackingStore(
                      GarbageCollectionReason::kExternalMemoryPressure);
     }
   }
-  // TODO(ulan): Perform GCs proactively based on the byte_length and
-  // the current external backing store counters.
   void* result = allocate(byte_length);
   if (result) return result;
   if (!always_allocate()) {
@@ -2948,7 +3089,7 @@ HeapObject CreateFillerObjectAtImpl(ReadOnlyRoots roots, Address addr, int size,
     DCHECK_GT(size, 2 * kTaggedSize);
     filler.set_map_after_allocation(roots.unchecked_free_space_map(),
                                     SKIP_WRITE_BARRIER);
-    FreeSpace::cast(filler).relaxed_write_size(size);
+    FreeSpace::cast(filler).set_size(size, kRelaxedStore);
     if (clear_memory_mode == ClearFreedMemoryMode::kClearFreedMemory) {
       MemsetTagged(ObjectSlot(addr) + 2, Object(kClearedFreeMemoryValue),
                    (size / kTaggedSize) - 2);
@@ -2957,7 +3098,7 @@ HeapObject CreateFillerObjectAtImpl(ReadOnlyRoots roots, Address addr, int size,
 
   // At this point, we may be deserializing the heap from a snapshot, and
   // none of the maps have been created yet and are nullptr.
-  DCHECK((filler.map_slot().contains_value(kNullAddress) &&
+  DCHECK((filler.map_slot().contains_map_value(kNullAddress) &&
           !Heap::FromWritableHeapObject(filler)->deserialization_complete()) ||
          filler.map().IsMap());
 
@@ -2969,8 +3110,7 @@ void VerifyNoNeedToClearSlots(Address start, Address end) {
   BasicMemoryChunk* basic_chunk = BasicMemoryChunk::FromAddress(start);
   if (basic_chunk->InReadOnlySpace()) return;
   MemoryChunk* chunk = static_cast<MemoryChunk*>(basic_chunk);
-  // TODO(ulan): Support verification of large pages.
-  if (chunk->InYoungGeneration() || chunk->IsLargePage()) return;
+  if (chunk->InYoungGeneration()) return;
   BaseSpace* space = chunk->owner();
   space->heap()->VerifySlotRangeHasNoRecordedSlots(start, end);
 }
@@ -3046,6 +3186,9 @@ bool Heap::IsImmovable(HeapObject object) {
 }
 
 bool Heap::IsLargeObject(HeapObject object) {
+  if (V8_ENABLE_THIRD_PARTY_HEAP_BOOL)
+    return third_party_heap::Heap::InLargeObjectSpace(object.address()) ||
+           third_party_heap::Heap::InSpace(object.address(), CODE_LO_SPACE);
   return BasicMemoryChunk::FromHeapObject(object)->IsLargePage();
 }
 
@@ -3109,6 +3252,9 @@ void Heap::OnMoveEvent(HeapObject target, HeapObject source,
   if (target.IsSharedFunctionInfo()) {
     LOG_CODE_EVENT(isolate_, SharedFunctionInfoMoveEvent(source.address(),
                                                          target.address()));
+  } else if (target.IsNativeContext()) {
+    PROFILE(isolate_,
+            NativeContextMoveEvent(source.address(), target.address()));
   }
 
   if (FLAG_verify_predictable) {
@@ -3184,7 +3330,8 @@ FixedArrayBase Heap::LeftTrimFixedArray(FixedArrayBase object,
   // Initialize header of the trimmed array. Since left trimming is only
   // performed on pages which are not concurrently swept creating a filler
   // object does not require synchronization.
-  RELAXED_WRITE_FIELD(object, bytes_to_trim, map);
+  RELAXED_WRITE_FIELD(object, bytes_to_trim,
+                      Object(MapWord::FromMap(map).ptr()));
   RELAXED_WRITE_FIELD(object, bytes_to_trim + kTaggedSize,
                       Smi::FromInt(len - elements_to_trim));
 
@@ -3298,7 +3445,7 @@ void Heap::CreateFillerForArray(T object, int elements_to_trim,
   // Initialize header of the trimmed array. We are storing the new length
   // using release store after creating a filler for the left-over space to
   // avoid races with the sweeper thread.
-  object.synchronized_set_length(object.length() - elements_to_trim);
+  object.set_length(object.length() - elements_to_trim, kReleaseStore);
 
   // Notify the heap object allocation tracker of change in object layout. The
   // array may not be moved during GC, and size has to be adjusted nevertheless.
@@ -3451,8 +3598,6 @@ void Heap::ActivateMemoryReducerIfNeeded() {
 }
 
 void Heap::ReduceNewSpaceSize() {
-  // TODO(ulan): Unify this constant with the similar constant in
-  // GCIdleTimeHandler once the change is merged to 4.5.
   static const size_t kLowAllocationThroughput = 1000;
   const double allocation_throughput =
       tracer()->CurrentAllocationThroughputInBytesPerMillisecond();
@@ -3468,6 +3613,12 @@ void Heap::ReduceNewSpaceSize() {
   }
 }
 
+size_t Heap::NewSpaceSize() { return new_space() ? new_space()->Size() : 0; }
+
+size_t Heap::NewSpaceCapacity() {
+  return new_space() ? new_space()->Capacity() : 0;
+}
+
 void Heap::FinalizeIncrementalMarkingIfComplete(
     GarbageCollectionReason gc_reason) {
   if (incremental_marking()->IsMarking() &&
@@ -3582,6 +3733,8 @@ class SlotCollectingVisitor final : public ObjectVisitor {
     UNREACHABLE();
   }
 
+  void VisitMapPointer(HeapObject object) override {}  // do nothing by default
+
   int number_of_slots() { return static_cast<int>(slots_.size()); }
 
   MaybeObjectSlot slot(int i) { return slots_[i]; }
@@ -3613,13 +3766,13 @@ void Heap::VerifyObjectLayoutChange(HeapObject object, Map new_map) {
     // Check that the set of slots before and after the transition match.
     SlotCollectingVisitor old_visitor;
     object.IterateFast(&old_visitor);
-    MapWord old_map_word = object.map_word();
+    MapWord old_map_word = object.map_word(kRelaxedLoad);
     // Temporarily set the new map to iterate new slots.
-    object.set_map_word(MapWord::FromMap(new_map));
+    object.set_map_word(MapWord::FromMap(new_map), kRelaxedStore);
     SlotCollectingVisitor new_visitor;
     object.IterateFast(&new_visitor);
     // Restore the old map.
-    object.set_map_word(old_map_word);
+    object.set_map_word(old_map_word, kRelaxedStore);
     DCHECK_EQ(new_visitor.number_of_slots(), old_visitor.number_of_slots());
     for (int i = 0; i < new_visitor.number_of_slots(); i++) {
       DCHECK_EQ(new_visitor.slot(i), old_visitor.slot(i));
@@ -3692,12 +3845,15 @@ void Heap::IdleNotificationEpilogue(GCIdleTimeAction action,
   }
 }
 
-double Heap::MonotonicallyIncreasingTimeInMs() {
+double Heap::MonotonicallyIncreasingTimeInMs() const {
   return V8::GetCurrentPlatform()->MonotonicallyIncreasingTime() *
          static_cast<double>(base::Time::kMillisecondsPerSecond);
 }
 
-void Heap::VerifyNewSpaceTop() { new_space()->VerifyTop(); }
+void Heap::VerifyNewSpaceTop() {
+  if (!new_space()) return;
+  new_space()->VerifyTop();
+}
 
 bool Heap::IdleNotification(int idle_time_in_ms) {
   return IdleNotification(
@@ -3866,6 +4022,11 @@ void Heap::AppendArrayBufferExtension(JSArrayBuffer object,
   array_buffer_sweeper_->Append(object, extension);
 }
 
+void Heap::DetachArrayBufferExtension(JSArrayBuffer object,
+                                      ArrayBufferExtension* extension) {
+  return array_buffer_sweeper_->Detach(object, extension);
+}
+
 void Heap::AutomaticallyRestoreInitialHeapLimit(double threshold_percent) {
   initial_max_old_generation_size_threshold_ =
       initial_max_old_generation_size_ * threshold_percent;
@@ -4009,13 +4170,23 @@ bool Heap::Contains(HeapObject value) const {
     return false;
   }
   return HasBeenSetUp() &&
-         (new_space_->ToSpaceContains(value) || old_space_->Contains(value) ||
-          code_space_->Contains(value) || map_space_->Contains(value) ||
-          lo_space_->Contains(value) || code_lo_space_->Contains(value) ||
-          new_lo_space_->Contains(value));
+         ((new_space_ && new_space_->ToSpaceContains(value)) ||
+          old_space_->Contains(value) || code_space_->Contains(value) ||
+          map_space_->Contains(value) || lo_space_->Contains(value) ||
+          code_lo_space_->Contains(value) ||
+          (new_lo_space_ && new_lo_space_->Contains(value)));
+}
+
+bool Heap::SharedHeapContains(HeapObject value) const {
+  if (shared_old_space_)
+    return shared_old_space_->Contains(value) ||
+           shared_map_space_->Contains(value);
+  return false;
 }
 
 bool Heap::InSpace(HeapObject value, AllocationSpace space) const {
+  if (V8_ENABLE_THIRD_PARTY_HEAP_BOOL)
+    return third_party_heap::Heap::InSpace(value.address(), space);
   if (memory_allocator()->IsOutsideAllocatedSpace(value.address())) {
     return false;
   }
@@ -4042,6 +4213,8 @@ bool Heap::InSpace(HeapObject value, AllocationSpace space) const {
   UNREACHABLE();
 }
 
+bool Heap::IsShared() { return isolate()->is_shared(); }
+
 bool Heap::InSpaceSlow(Address addr, AllocationSpace space) const {
   if (memory_allocator()->IsOutsideAllocatedSpace(addr)) {
     return false;
@@ -4116,7 +4289,7 @@ void Heap::Verify() {
   VerifySmisVisitor smis_visitor;
   IterateSmiRoots(&smis_visitor);
 
-  new_space_->Verify(isolate());
+  if (new_space_) new_space_->Verify(isolate());
 
   old_space_->Verify(isolate(), &visitor);
   map_space_->Verify(isolate(), &visitor);
@@ -4126,7 +4299,7 @@ void Heap::Verify() {
 
   lo_space_->Verify(isolate());
   code_lo_space_->Verify(isolate());
-  new_lo_space_->Verify(isolate());
+  if (new_lo_space_) new_lo_space_->Verify(isolate());
   VerifyStringTable(isolate());
 }
 
@@ -4147,7 +4320,7 @@ class SlotVerifyingVisitor : public ObjectVisitor {
                      ObjectSlot end) override {
 #ifdef DEBUG
     for (ObjectSlot slot = start; slot < end; ++slot) {
-      DCHECK(!HasWeakHeapObjectTag(*slot));
+      DCHECK(!MapWord::IsPacked((*slot).ptr()) || !HasWeakHeapObjectTag(*slot));
     }
 #endif  // DEBUG
     VisitPointers(host, MaybeObjectSlot(start), MaybeObjectSlot(end));
@@ -4315,7 +4488,7 @@ void Heap::VerifyCountersBeforeConcurrentSweeping() {
 #endif
 
 void Heap::ZapFromSpace() {
-  if (!new_space_->IsFromSpaceCommitted()) return;
+  if (!new_space_ || !new_space_->IsFromSpaceCommitted()) return;
   for (Page* page : PageRange(new_space_->from_space().first_page(), nullptr)) {
     memory_allocator()->ZapBlock(page->area_start(),
                                  page->HighWaterMark() - page->area_start(),
@@ -4397,18 +4570,20 @@ class FixStaleLeftTrimmedHandlesVisitor : public RootVisitor {
 
   void VisitRootPointers(Root root, const char* description,
                          FullObjectSlot start, FullObjectSlot end) override {
-    for (FullObjectSlot p = start; p < end; ++p) FixHandle(p);
+    for (FullObjectSlot p = start; p < end; ++p) {
+      FixHandle(p);
+    }
   }
 
  private:
   inline void FixHandle(FullObjectSlot p) {
     if (!(*p).IsHeapObject()) return;
     HeapObject current = HeapObject::cast(*p);
-    if (!current.map_word().IsForwardingAddress() &&
+    if (!current.map_word(kRelaxedLoad).IsForwardingAddress() &&
         current.IsFreeSpaceOrFiller()) {
 #ifdef DEBUG
       // We need to find a FixedArrayBase map after walking the fillers.
-      while (!current.map_word().IsForwardingAddress() &&
+      while (!current.map_word(kRelaxedLoad).IsForwardingAddress() &&
              current.IsFreeSpaceOrFiller()) {
         Address next = current.ptr();
         if (current.map() == ReadOnlyRoots(heap_).one_pointer_filler_map()) {
@@ -4421,7 +4596,7 @@ class FixStaleLeftTrimmedHandlesVisitor : public RootVisitor {
         }
         current = HeapObject::cast(Object(next));
       }
-      DCHECK(current.map_word().IsForwardingAddress() ||
+      DCHECK(current.map_word(kRelaxedLoad).IsForwardingAddress() ||
              current.IsFixedArrayBase());
 #endif  // DEBUG
       p.store(Smi::zero());
@@ -4502,8 +4677,10 @@ void Heap::IterateRoots(RootVisitor* v, base::EnumSet<SkipRoot> options) {
     // Iterate over local handles in handle scopes.
     FixStaleLeftTrimmedHandlesVisitor left_trim_visitor(this);
 #ifndef V8_ENABLE_CONSERVATIVE_STACK_SCANNING
-    isolate_->handle_scope_implementer()->Iterate(&left_trim_visitor);
-    isolate_->handle_scope_implementer()->Iterate(v);
+    if (!options.contains(SkipRoot::kMainThreadHandles)) {
+      isolate_->handle_scope_implementer()->Iterate(&left_trim_visitor);
+      isolate_->handle_scope_implementer()->Iterate(v);
+    }
 #endif
 
     safepoint_->Iterate(&left_trim_visitor);
@@ -4772,8 +4949,8 @@ void Heap::RecordStats(HeapStats* stats, bool take_snapshot) {
   *stats->end_marker = HeapStats::kEndMarker;
   *stats->ro_space_size = read_only_space_->Size();
   *stats->ro_space_capacity = read_only_space_->Capacity();
-  *stats->new_space_size = new_space_->Size();
-  *stats->new_space_capacity = new_space_->Capacity();
+  *stats->new_space_size = NewSpaceSize();
+  *stats->new_space_capacity = NewSpaceCapacity();
   *stats->old_space_size = old_space_->SizeOfObjects();
   *stats->old_space_capacity = old_space_->Capacity();
   *stats->code_space_size = code_space_->SizeOfObjects();
@@ -5036,9 +5213,9 @@ Heap::IncrementalMarkingLimit Heap::IncrementalMarkingLimitReached() {
   const base::Optional<size_t> global_memory_available =
       GlobalMemoryAvailable();
 
-  if (old_generation_space_available > new_space_->Capacity() &&
+  if (old_generation_space_available > NewSpaceCapacity() &&
       (!global_memory_available ||
-       global_memory_available > new_space_->Capacity())) {
+       global_memory_available > NewSpaceCapacity())) {
     return IncrementalMarkingLimit::kNoLimit;
   }
   if (ShouldOptimizeForMemoryUsage()) {
@@ -5065,8 +5242,10 @@ void Heap::EnableInlineAllocation() {
   inline_allocation_disabled_ = false;
 
   // Update inline allocation limit for new space.
-  new_space()->AdvanceAllocationObservers();
-  new_space()->UpdateInlineAllocationLimit(0);
+  if (new_space()) {
+    new_space()->AdvanceAllocationObservers();
+    new_space()->UpdateInlineAllocationLimit(0);
+  }
 }
 
 void Heap::DisableInlineAllocation() {
@@ -5074,7 +5253,9 @@ void Heap::DisableInlineAllocation() {
   inline_allocation_disabled_ = true;
 
   // Update inline allocation limit for new space.
-  new_space()->UpdateInlineAllocationLimit(0);
+  if (new_space()) {
+    new_space()->UpdateInlineAllocationLimit(0);
+  }
 
   // Update inline allocation limit for old spaces.
   PagedSpaceIterator spaces(this);
@@ -5138,6 +5319,10 @@ HeapObject Heap::AllocateRawWithRetryOrFailSlowPath(
   return HeapObject();
 }
 
+namespace {
+V8_DECLARE_ONCE(initialize_shared_code_range_once);
+}  // namespace
+
 void Heap::SetUp() {
 #ifdef V8_ENABLE_ALLOCATION_TIMEOUT
   allocation_timeout_ = NextAllocationTimeout();
@@ -5159,9 +5344,45 @@ void Heap::SetUp() {
       reinterpret_cast<uintptr_t>(v8::internal::GetRandomMmapAddr()) &
       ~kMmapRegionMask;
 
+  v8::PageAllocator* code_page_allocator;
+  if (isolate_->RequiresCodeRange() || code_range_size_ != 0) {
+    const size_t requested_size =
+        code_range_size_ == 0 ? kMaximalCodeRangeSize : code_range_size_;
+    // When a target requires the code range feature, we put all code objects in
+    // a contiguous range of virtual address space, so that they can call each
+    // other with near calls.
+    if (COMPRESS_POINTERS_IN_SHARED_CAGE_BOOL) {
+      // When sharing a pointer cage among Isolates, also share the
+      // CodeRange. isolate_->page_allocator() is the process-wide pointer
+      // compression cage's PageAllocator.
+      base::CallOnce(&initialize_shared_code_range_once,
+                     &CodeRange::InitializeProcessWideCodeRangeOnce,
+                     isolate_->page_allocator(), requested_size);
+      code_range_ = CodeRange::GetProcessWideCodeRange();
+    } else {
+      code_range_ = std::make_shared<CodeRange>();
+      if (!code_range_->InitReservation(isolate_->page_allocator(),
+                                        requested_size)) {
+        V8::FatalProcessOutOfMemory(
+            isolate_, "Failed to reserve virtual memory for CodeRange");
+      }
+    }
+
+    LOG(isolate_,
+        NewEvent("CodeRange",
+                 reinterpret_cast<void*>(code_range_->reservation()->address()),
+                 code_range_size_));
+
+    isolate_->AddCodeRange(code_range_->reservation()->region().begin(),
+                           code_range_->reservation()->region().size());
+    code_page_allocator = code_range_->page_allocator();
+  } else {
+    code_page_allocator = isolate_->page_allocator();
+  }
+
   // Set up memory allocator.
   memory_allocator_.reset(
-      new MemoryAllocator(isolate_, MaxReserved(), code_range_size_));
+      new MemoryAllocator(isolate_, code_page_allocator, MaxReserved()));
 
   mark_compact_collector_.reset(new MarkCompactCollector(this));
 
@@ -5203,49 +5424,6 @@ void Heap::ReplaceReadOnlySpace(SharedReadOnlySpace* space) {
   read_only_space_ = space;
 }
 
-uint8_t* Heap::RemapEmbeddedBuiltinsIntoCodeRange(
-    const uint8_t* embedded_blob_code, size_t embedded_blob_code_size) {
-  const base::AddressRegion& code_range = memory_allocator()->code_range();
-
-  CHECK_NE(code_range.begin(), kNullAddress);
-  CHECK(!code_range.is_empty());
-
-  v8::PageAllocator* code_page_allocator =
-      memory_allocator()->code_page_allocator();
-
-  const size_t kAllocatePageSize = code_page_allocator->AllocatePageSize();
-  size_t allocate_code_size =
-      RoundUp(embedded_blob_code_size, kAllocatePageSize);
-
-  // Allocate the re-embedded code blob in the end.
-  void* hint = reinterpret_cast<void*>(code_range.end() - allocate_code_size);
-
-  void* embedded_blob_copy = code_page_allocator->AllocatePages(
-      hint, allocate_code_size, kAllocatePageSize, PageAllocator::kNoAccess);
-
-  if (!embedded_blob_copy) {
-    V8::FatalProcessOutOfMemory(
-        isolate(), "Can't allocate space for re-embedded builtins");
-  }
-
-  size_t code_size =
-      RoundUp(embedded_blob_code_size, code_page_allocator->CommitPageSize());
-
-  if (!code_page_allocator->SetPermissions(embedded_blob_copy, code_size,
-                                           PageAllocator::kReadWrite)) {
-    V8::FatalProcessOutOfMemory(isolate(),
-                                "Re-embedded builtins: set permissions");
-  }
-  memcpy(embedded_blob_copy, embedded_blob_code, embedded_blob_code_size);
-
-  if (!code_page_allocator->SetPermissions(embedded_blob_copy, code_size,
-                                           PageAllocator::kReadExecute)) {
-    V8::FatalProcessOutOfMemory(isolate(),
-                                "Re-embedded builtins: set permissions");
-  }
-  return reinterpret_cast<uint8_t*>(embedded_blob_copy);
-}
-
 class StressConcurrentAllocationObserver : public AllocationObserver {
  public:
   explicit StressConcurrentAllocationObserver(Heap* heap)
@@ -5269,15 +5447,19 @@ class StressConcurrentAllocationObserver : public AllocationObserver {
 void Heap::SetUpSpaces() {
   // Ensure SetUpFromReadOnlySpace has been ran.
   DCHECK_NOT_NULL(read_only_space_);
-  space_[NEW_SPACE] = new_space_ =
-      new NewSpace(this, memory_allocator_->data_page_allocator(),
-                   initial_semispace_size_, max_semi_space_size_);
+  if (!FLAG_single_generation) {
+    space_[NEW_SPACE] = new_space_ =
+        new NewSpace(this, memory_allocator_->data_page_allocator(),
+                     initial_semispace_size_, max_semi_space_size_);
+  }
   space_[OLD_SPACE] = old_space_ = new OldSpace(this);
   space_[CODE_SPACE] = code_space_ = new CodeSpace(this);
   space_[MAP_SPACE] = map_space_ = new MapSpace(this);
   space_[LO_SPACE] = lo_space_ = new OldLargeObjectSpace(this);
-  space_[NEW_LO_SPACE] = new_lo_space_ =
-      new NewLargeObjectSpace(this, new_space_->Capacity());
+  if (!FLAG_single_generation) {
+    space_[NEW_LO_SPACE] = new_lo_space_ =
+        new NewLargeObjectSpace(this, NewSpaceCapacity());
+  }
   space_[CODE_LO_SPACE] = code_lo_space_ = new CodeLargeObjectSpace(this);
 
   for (int i = 0; i < static_cast<int>(v8::Isolate::kUseCounterFeatureCount);
@@ -5300,6 +5482,8 @@ void Heap::SetUpSpaces() {
     dead_object_stats_.reset(new ObjectStats(this));
   }
   local_embedder_heap_tracer_.reset(new LocalEmbedderHeapTracer(isolate()));
+  embedder_roots_handler_ =
+      &local_embedder_heap_tracer()->default_embedder_roots_handler();
 
   LOG(isolate_, IntPtrTEvent("heap-capacity", Capacity()));
   LOG(isolate_, IntPtrTEvent("heap-available", Available()));
@@ -5311,10 +5495,12 @@ void Heap::SetUpSpaces() {
   }
 #endif  // ENABLE_MINOR_MC
 
-  scavenge_job_.reset(new ScavengeJob());
-  scavenge_task_observer_.reset(new ScavengeTaskObserver(
-      this, ScavengeJob::YoungGenerationTaskTriggerSize(this)));
-  new_space()->AddAllocationObserver(scavenge_task_observer_.get());
+  if (!FLAG_single_generation) {
+    scavenge_job_.reset(new ScavengeJob());
+    scavenge_task_observer_.reset(new ScavengeTaskObserver(
+        this, ScavengeJob::YoungGenerationTaskTriggerSize(this)));
+    new_space()->AddAllocationObserver(scavenge_task_observer_.get());
+  }
 
   SetGetExternallyAllocatedMemoryInBytesCallback(
       DefaultGetExternallyAllocatedMemoryInBytesCallback);
@@ -5325,7 +5511,7 @@ void Heap::SetUpSpaces() {
     AddAllocationObserversToAllSpaces(stress_marking_observer_,
                                       stress_marking_observer_);
   }
-  if (FLAG_stress_scavenge > 0) {
+  if (FLAG_stress_scavenge > 0 && new_space()) {
     stress_scavenge_observer_ = new StressScavengeObserver(this);
     new_space()->AddAllocationObserver(stress_scavenge_observer_);
   }
@@ -5333,6 +5519,11 @@ void Heap::SetUpSpaces() {
   write_protect_code_memory_ = FLAG_write_protect_code_memory;
 }
 
+void Heap::InitializeMainThreadLocalHeap(LocalHeap* main_thread_local_heap) {
+  DCHECK_NULL(main_thread_local_heap_);
+  main_thread_local_heap_ = main_thread_local_heap;
+}
+
 void Heap::InitializeHashSeed() {
   DCHECK(!deserialization_complete_);
   uint64_t new_hash_seed;
@@ -5438,6 +5629,14 @@ void Heap::SetEmbedderHeapTracer(EmbedderHeapTracer* tracer) {
   local_embedder_heap_tracer()->SetRemoteTracer(tracer);
 }
 
+void Heap::SetEmbedderRootsHandler(EmbedderRootsHandler* handler) {
+  embedder_roots_handler_ = handler;
+}
+
+EmbedderRootsHandler* Heap::GetEmbedderRootsHandler() const {
+  return embedder_roots_handler_;
+}
+
 EmbedderHeapTracer* Heap::GetEmbedderHeapTracer() const {
   return local_embedder_heap_tracer()->remote_tracer();
 }
@@ -5461,6 +5660,11 @@ EmbedderHeapTracer::TraceFlags Heap::flags_for_embedder_tracer() const {
   return EmbedderHeapTracer::TraceFlags::kNoFlags;
 }
 
+const cppgc::EmbedderStackState* Heap::overriden_stack_state() const {
+  const auto* cpp_heap = CppHeap::From(cpp_heap_);
+  return cpp_heap ? cpp_heap->override_stack_state() : nullptr;
+}
+
 void Heap::RegisterExternallyReferencedObject(Address* location) {
   GlobalHandles::MarkTraced(location);
   Object object(*location);
@@ -5524,7 +5728,10 @@ void Heap::TearDown() {
     }
   }
 
-  new_space()->RemoveAllocationObserver(scavenge_task_observer_.get());
+  if (new_space()) {
+    new_space()->RemoveAllocationObserver(scavenge_task_observer_.get());
+  }
+
   scavenge_task_observer_.reset();
   scavenge_job_.reset();
 
@@ -5541,7 +5748,7 @@ void Heap::TearDown() {
     delete stress_marking_observer_;
     stress_marking_observer_ = nullptr;
   }
-  if (FLAG_stress_scavenge > 0) {
+  if (FLAG_stress_scavenge > 0 && new_space()) {
     new_space()->RemoveAllocationObserver(stress_scavenge_observer_);
     delete stress_scavenge_observer_;
     stress_scavenge_observer_ = nullptr;
@@ -5578,6 +5785,8 @@ void Heap::TearDown() {
   dead_object_stats_.reset();
 
   local_embedder_heap_tracer_.reset();
+  embedder_roots_handler_ = nullptr;
+
   if (cpp_heap_) {
     CppHeap::From(cpp_heap_)->DetachIsolate();
     cpp_heap_ = nullptr;
@@ -5587,6 +5796,8 @@ void Heap::TearDown() {
 
   tracer_.reset();
 
+  allocation_sites_to_pretenure_.reset();
+
   for (int i = FIRST_MUTABLE_SPACE; i <= LAST_MUTABLE_SPACE; i++) {
     delete space_[i];
     space_[i] = nullptr;
@@ -5608,6 +5819,24 @@ void Heap::TearDown() {
   memory_allocator_.reset();
 }
 
+void Heap::InitSharedSpaces() {
+  shared_old_space_ = isolate()->shared_isolate()->heap()->old_space();
+  shared_old_allocator_.reset(
+      new ConcurrentAllocator(main_thread_local_heap(), shared_old_space_));
+
+  shared_map_space_ = isolate()->shared_isolate()->heap()->map_space();
+  shared_map_allocator_.reset(
+      new ConcurrentAllocator(main_thread_local_heap(), shared_map_space_));
+}
+
+void Heap::DeinitSharedSpaces() {
+  shared_old_space_ = nullptr;
+  shared_old_allocator_.reset();
+
+  shared_map_space_ = nullptr;
+  shared_map_allocator_.reset();
+}
+
 void Heap::AddGCPrologueCallback(v8::Isolate::GCCallbackWithData callback,
                                  GCType gc_type, void* data) {
   DCHECK_NOT_NULL(callback);
@@ -5685,7 +5914,7 @@ Handle<WeakArrayList> CompactWeakArrayList(Heap* heap,
 
 }  // anonymous namespace
 
-void Heap::CompactWeakArrayLists(AllocationType allocation) {
+void Heap::CompactWeakArrayLists() {
   // Find known PrototypeUsers and compact them.
   std::vector<Handle<PrototypeInfo>> prototype_infos;
   {
@@ -5702,20 +5931,18 @@ void Heap::CompactWeakArrayLists(AllocationType allocation) {
   for (auto& prototype_info : prototype_infos) {
     Handle<WeakArrayList> array(
         WeakArrayList::cast(prototype_info->prototype_users()), isolate());
-    DCHECK_IMPLIES(allocation == AllocationType::kOld,
-                   InOldSpace(*array) ||
-                       *array == ReadOnlyRoots(this).empty_weak_array_list());
+    DCHECK(InOldSpace(*array) ||
+           *array == ReadOnlyRoots(this).empty_weak_array_list());
     WeakArrayList new_array = PrototypeUsers::Compact(
-        array, this, JSObject::PrototypeRegistryCompactionCallback, allocation);
+        array, this, JSObject::PrototypeRegistryCompactionCallback,
+        AllocationType::kOld);
     prototype_info->set_prototype_users(new_array);
   }
 
   // Find known WeakArrayLists and compact them.
   Handle<WeakArrayList> scripts(script_list(), isolate());
-  DCHECK_IMPLIES(
-      !V8_ENABLE_THIRD_PARTY_HEAP_BOOL && allocation == AllocationType::kOld,
-      InOldSpace(*scripts));
-  scripts = CompactWeakArrayList(this, scripts, allocation);
+  DCHECK(InOldSpace(*scripts));
+  scripts = CompactWeakArrayList(this, scripts, AllocationType::kOld);
   set_script_list(*scripts);
 }
 
@@ -5847,7 +6074,6 @@ void Heap::VerifyClearedSlot(HeapObject object, ObjectSlot slot) {
 void Heap::VerifySlotRangeHasNoRecordedSlots(Address start, Address end) {
 #ifndef V8_DISABLE_WRITE_BARRIERS
   Page* page = Page::FromAddress(start);
-  DCHECK(!page->IsLargePage());
   DCHECK(!page->InYoungGeneration());
   RememberedSet<OLD_TO_NEW>::CheckNoneInRange(page, start, end);
 #endif
@@ -5887,18 +6113,26 @@ PagedSpace* PagedSpaceIterator::Next() {
 }
 
 SpaceIterator::SpaceIterator(Heap* heap)
-    : heap_(heap), current_space_(FIRST_MUTABLE_SPACE - 1) {}
+    : heap_(heap), current_space_(FIRST_MUTABLE_SPACE) {}
 
 SpaceIterator::~SpaceIterator() = default;
 
 bool SpaceIterator::HasNext() {
-  // Iterate until no more spaces.
-  return current_space_ != LAST_SPACE;
+  while (current_space_ <= LAST_MUTABLE_SPACE) {
+    Space* space = heap_->space(current_space_);
+    if (space) return true;
+    ++current_space_;
+  }
+
+  // No more spaces left.
+  return false;
 }
 
 Space* SpaceIterator::Next() {
   DCHECK(HasNext());
-  return heap_->space(++current_space_);
+  Space* space = heap_->space(current_space_++);
+  DCHECK_NOT_NULL(space);
+  return space;
 }
 
 class HeapObjectsFilter {
@@ -5922,14 +6156,14 @@ class UnreachableObjectsFilter : public HeapObjectsFilter {
 
   bool SkipObject(HeapObject object) override {
     if (object.IsFreeSpaceOrFiller()) return true;
-    BasicMemoryChunk* chunk = BasicMemoryChunk::FromHeapObject(object);
+    Address chunk = object.ptr() & ~kLogicalChunkAlignmentMask;
     if (reachable_.count(chunk) == 0) return true;
     return reachable_[chunk]->count(object) == 0;
   }
 
  private:
   bool MarkAsReachable(HeapObject object) {
-    BasicMemoryChunk* chunk = BasicMemoryChunk::FromHeapObject(object);
+    Address chunk = object.ptr() & ~kLogicalChunkAlignmentMask;
     if (reachable_.count(chunk) == 0) {
       reachable_[chunk] = new std::unordered_set<HeapObject, Object::Hasher>();
     }
@@ -5938,11 +6172,20 @@ class UnreachableObjectsFilter : public HeapObjectsFilter {
     return true;
   }
 
+  static constexpr intptr_t kLogicalChunkAlignment =
+      (static_cast<uintptr_t>(1) << kPageSizeBits);
+
+  static constexpr intptr_t kLogicalChunkAlignmentMask =
+      kLogicalChunkAlignment - 1;
+
   class MarkingVisitor : public ObjectVisitor, public RootVisitor {
    public:
     explicit MarkingVisitor(UnreachableObjectsFilter* filter)
         : filter_(filter) {}
 
+    void VisitMapPointer(HeapObject object) override {
+      MarkHeapObject(Map::unchecked_cast(object.map()));
+    }
     void VisitPointers(HeapObject host, ObjectSlot start,
                        ObjectSlot end) override {
       MarkPointers(MaybeObjectSlot(start), MaybeObjectSlot(end));
@@ -6017,8 +6260,7 @@ class UnreachableObjectsFilter : public HeapObjectsFilter {
 
   Heap* heap_;
   DISALLOW_GARBAGE_COLLECTION(no_gc_)
-  std::unordered_map<BasicMemoryChunk*,
-                     std::unordered_set<HeapObject, Object::Hasher>*>
+  std::unordered_map<Address, std::unordered_set<HeapObject, Object::Hasher>*>
       reachable_;
 };
 
@@ -6041,13 +6283,14 @@ HeapObjectIterator::HeapObjectIterator(
       break;
   }
   object_iterator_ = space_iterator_->Next()->GetObjectIterator(heap_);
+  if (V8_ENABLE_THIRD_PARTY_HEAP_BOOL) heap_->tp_heap_->ResetIterator();
 }
 
 HeapObjectIterator::~HeapObjectIterator() {
 #ifdef DEBUG
   // Assert that in filtering mode we have iterated through all
   // objects. Otherwise, heap will be left in an inconsistent state.
-  if (filtering_ != kNoFiltering) {
+  if (!V8_ENABLE_THIRD_PARTY_HEAP_BOOL && filtering_ != kNoFiltering) {
     DCHECK_NULL(object_iterator_);
   }
 #endif
@@ -6064,6 +6307,7 @@ HeapObject HeapObjectIterator::Next() {
 }
 
 HeapObject HeapObjectIterator::NextObject() {
+  if (V8_ENABLE_THIRD_PARTY_HEAP_BOOL) return heap_->tp_heap_->NextObject();
   // No iterator means we are done.
   if (object_iterator_.get() == nullptr) return HeapObject();
 
@@ -6288,8 +6532,6 @@ MaybeHandle<JSFinalizationRegistry> Heap::DequeueDirtyJSFinalizationRegistry() {
 }
 
 void Heap::RemoveDirtyFinalizationRegistriesOnContext(NativeContext context) {
-  if (!FLAG_harmony_weak_refs) return;
-
   DisallowGarbageCollection no_gc;
 
   Isolate* isolate = this->isolate();
@@ -6319,7 +6561,6 @@ void Heap::RemoveDirtyFinalizationRegistriesOnContext(NativeContext context) {
 }
 
 void Heap::KeepDuringJob(Handle<JSReceiver> target) {
-  DCHECK(FLAG_harmony_weak_refs);
   DCHECK(weak_refs_keep_during_job().IsUndefined() ||
          weak_refs_keep_during_job().IsOrderedHashSet());
   Handle<OrderedHashSet> table;
@@ -6454,7 +6695,8 @@ void VerifyPointersVisitor::VerifyPointersImpl(TSlot start, TSlot end) {
     if (object.GetHeapObject(&heap_object)) {
       VerifyHeapObjectImpl(heap_object);
     } else {
-      CHECK(object.IsSmi() || object.IsCleared());
+      CHECK(object.IsSmi() || object.IsCleared() ||
+            MapWord::IsPacked(object.ptr()));
     }
   }
 }
@@ -6538,7 +6780,7 @@ void Heap::CreateObjectStats() {
 }
 
 Map Heap::GcSafeMapOfCodeSpaceObject(HeapObject object) {
-  MapWord map_word = object.map_word();
+  MapWord map_word = object.map_word(kRelaxedLoad);
   return map_word.IsForwardingAddress() ? map_word.ToForwardingAddress().map()
                                         : map_word.ToMap();
 }
@@ -6701,6 +6943,7 @@ template void Heap::WriteBarrierForRange<MaybeObjectSlot>(
 template <typename TSlot>
 void Heap::WriteBarrierForRange(HeapObject object, TSlot start_slot,
                                 TSlot end_slot) {
+  if (FLAG_disable_write_barriers) return;
   MemoryChunk* source_page = MemoryChunk::FromHeapObject(object);
   base::Flags<RangeWriteBarrierMode> mode;
 
diff --git a/chromium/v8/src/heap/heap.h b/chromium/v8/src/heap/heap.h
index 429f8864be7..4be4d8f7325 100644
--- a/chromium/v8/src/heap/heap.h
+++ b/chromium/v8/src/heap/heap.h
@@ -66,12 +66,16 @@ class ArrayBufferCollector;
 class ArrayBufferSweeper;
 class BasicMemoryChunk;
 class CodeLargeObjectSpace;
+class CodeRange;
 class CollectionBarrier;
+class ConcurrentAllocator;
 class ConcurrentMarking;
 class CppHeap;
 class GCIdleTimeHandler;
 class GCIdleTimeHeapState;
 class GCTracer;
+template <typename T>
+class GlobalHandleVector;
 class GlobalSafepoint;
 class HeapObjectAllocationTracker;
 class HeapObjectsFilter;
@@ -176,6 +180,7 @@ enum class SkipRoot {
   kGlobalHandles,
   kOldGeneration,
   kStack,
+  kMainThreadHandles,
   kUnserializable,
   kWeak
 };
@@ -194,7 +199,7 @@ class StrongRootsEntry {
 
 class AllocationResult {
  public:
-  static inline AllocationResult Retry(AllocationSpace space = NEW_SPACE) {
+  static inline AllocationResult Retry(AllocationSpace space) {
     return AllocationResult(space);
   }
 
@@ -513,6 +518,9 @@ class Heap {
   inline Address* OldSpaceAllocationTopAddress();
   inline Address* OldSpaceAllocationLimitAddress();
 
+  size_t NewSpaceSize();
+  size_t NewSpaceCapacity();
+
   // Move len non-weak tagged elements from src_slot to dst_slot of dst_object.
   // The source and destination memory ranges can overlap.
   V8_EXPORT_PRIVATE void MoveRange(HeapObject dst_object, ObjectSlot dst_slot,
@@ -566,9 +574,12 @@ class Heap {
   V8_EXPORT_PRIVATE int NotifyContextDisposed(bool dependant_context);
 
   void set_native_contexts_list(Object object) {
-    native_contexts_list_ = object;
+    native_contexts_list_.store(object.ptr(), std::memory_order_release);
+  }
+
+  Object native_contexts_list() const {
+    return Object(native_contexts_list_.load(std::memory_order_acquire));
   }
-  Object native_contexts_list() const { return native_contexts_list_; }
 
   void set_allocation_sites_list(Object object) {
     allocation_sites_list_ = object;
@@ -693,10 +704,12 @@ class Heap {
 
   void AppendArrayBufferExtension(JSArrayBuffer object,
                                   ArrayBufferExtension* extension);
+  void DetachArrayBufferExtension(JSArrayBuffer object,
+                                  ArrayBufferExtension* extension);
 
   GlobalSafepoint* safepoint() { return safepoint_.get(); }
 
-  V8_EXPORT_PRIVATE double MonotonicallyIncreasingTimeInMs();
+  V8_EXPORT_PRIVATE double MonotonicallyIncreasingTimeInMs() const;
 
   void VerifyNewSpaceTop();
 
@@ -743,7 +756,7 @@ class Heap {
 
   size_t backing_store_bytes() const { return backing_store_bytes_; }
 
-  void CompactWeakArrayLists(AllocationType allocation);
+  void CompactWeakArrayLists();
 
   V8_EXPORT_PRIVATE void AddRetainedMap(Handle<NativeContext> context,
                                         Handle<Map> map);
@@ -760,6 +773,11 @@ class Heap {
   inline bool CanAllocateInReadOnlySpace();
   bool deserialization_complete() const { return deserialization_complete_; }
 
+  // We can only invoke Safepoint() on the main thread local heap after
+  // deserialization is complete. Before that, main_thread_local_heap_ might be
+  // null.
+  V8_INLINE bool CanSafepoint() const { return deserialization_complete(); }
+
   bool HasLowAllocationRate();
   bool HasHighFragmentation();
   bool HasHighFragmentation(size_t used, size_t committed);
@@ -802,6 +820,9 @@ class Heap {
   // Sets up the heap memory without creating any objects.
   void SetUpSpaces();
 
+  // Prepares the heap, setting up for deserialization.
+  void InitializeMainThreadLocalHeap(LocalHeap* main_thread_local_heap);
+
   // (Re-)Initialize hash seed from flag or RNG.
   void InitializeHashSeed();
 
@@ -812,12 +833,6 @@ class Heap {
   // Create ObjectStats if live_object_stats_ or dead_object_stats_ are nullptr.
   void CreateObjectStats();
 
-  // If the code range exists, allocates executable pages in the code range and
-  // copies the embedded builtins code blob there. Returns address of the copy.
-  // The builtins code region will be freed with the code range at tear down.
-  uint8_t* RemapEmbeddedBuiltinsIntoCodeRange(const uint8_t* embedded_blob_code,
-                                              size_t embedded_blob_code_size);
-
   // Sets the TearDown state, so no new GC tasks get posted.
   void StartTearDown();
 
@@ -827,6 +842,12 @@ class Heap {
   // Returns whether SetUp has been called.
   bool HasBeenSetUp() const;
 
+  // Initialializes shared spaces.
+  void InitSharedSpaces();
+
+  // Removes shared spaces again.
+  void DeinitSharedSpaces();
+
   // ===========================================================================
   // Getters for spaces. =======================================================
   // ===========================================================================
@@ -857,6 +878,7 @@ class Heap {
   }
 
   inline Isolate* isolate();
+  inline const Isolate* isolate() const;
 
   MarkCompactCollector* mark_compact_collector() {
     return mark_compact_collector_.get();
@@ -870,7 +892,11 @@ class Heap {
     return array_buffer_sweeper_.get();
   }
 
-  const base::AddressRegion& code_range();
+  const base::AddressRegion& code_region();
+
+  CodeRange* code_range() { return code_range_.get(); }
+
+  LocalHeap* main_thread_local_heap() { return main_thread_local_heap_; }
 
   // ===========================================================================
   // Root set access. ==========================================================
@@ -1076,17 +1102,19 @@ class Heap {
 
   void EnsureSweepingCompleted();
 
-  IncrementalMarking* incremental_marking() {
+  IncrementalMarking* incremental_marking() const {
     return incremental_marking_.get();
   }
 
-  MarkingBarrier* marking_barrier() { return marking_barrier_.get(); }
+  MarkingBarrier* marking_barrier() const { return marking_barrier_.get(); }
 
   // ===========================================================================
   // Concurrent marking API. ===================================================
   // ===========================================================================
 
-  ConcurrentMarking* concurrent_marking() { return concurrent_marking_.get(); }
+  ConcurrentMarking* concurrent_marking() const {
+    return concurrent_marking_.get();
+  }
 
   // The runtime uses this function to notify potentially unsafe object layout
   // changes that require special synchronization with the concurrent marker.
@@ -1150,6 +1178,16 @@ class Heap {
 
   v8::CppHeap* cpp_heap() const { return cpp_heap_; }
 
+  const cppgc::EmbedderStackState* overriden_stack_state() const;
+
+  // ===========================================================================
+  // Embedder roots optimizations. =============================================
+  // ===========================================================================
+
+  V8_EXPORT_PRIVATE void SetEmbedderRootsHandler(EmbedderRootsHandler* handler);
+
+  EmbedderRootsHandler* GetEmbedderRootsHandler() const;
+
   // ===========================================================================
   // External string table API. ================================================
   // ===========================================================================
@@ -1192,10 +1230,18 @@ class Heap {
   // heaps is required.
   V8_EXPORT_PRIVATE bool Contains(HeapObject value) const;
 
+  // Checks whether an address/object is in the non-read-only heap (including
+  // auxiliary area and unused area). Use IsValidHeapObject if checking both
+  // heaps is required.
+  V8_EXPORT_PRIVATE bool SharedHeapContains(HeapObject value) const;
+
   // Checks whether an address/object in a space.
   // Currently used by tests, serialization and heap verification only.
   V8_EXPORT_PRIVATE bool InSpace(HeapObject value, AllocationSpace space) const;
 
+  // Returns true when this heap is shared.
+  V8_EXPORT_PRIVATE bool IsShared();
+
   // Slow methods that can be used for verification as they can also be used
   // with off-heap Addresses.
   V8_EXPORT_PRIVATE bool InSpaceSlow(Address addr, AllocationSpace space) const;
@@ -1335,9 +1381,9 @@ class Heap {
     survived_since_last_expansion_ += survived;
   }
 
-  inline void UpdateNewSpaceAllocationCounter();
+  void UpdateNewSpaceAllocationCounter();
 
-  inline size_t NewSpaceAllocationCounter();
+  V8_EXPORT_PRIVATE size_t NewSpaceAllocationCounter();
 
   // This should be used only for testing.
   void set_new_space_allocation_counter(size_t new_value) {
@@ -1451,6 +1497,12 @@ class Heap {
   void MergeAllocationSitePretenuringFeedback(
       const PretenuringFeedbackMap& local_pretenuring_feedback);
 
+  // Adds an allocation site to the list of sites to be pretenured during the
+  // next collection. Added allocation sites are pretenured independent of
+  // their feedback.
+  V8_EXPORT_PRIVATE void PretenureAllocationSiteOnNextCollection(
+      AllocationSite site);
+
   // ===========================================================================
   // Allocation tracking. ======================================================
   // ===========================================================================
@@ -2020,7 +2072,7 @@ class Heap {
       AllocationAlignment alignment = kWordAligned);
 
   // Allocates a heap object based on the map.
-  V8_WARN_UNUSED_RESULT AllocationResult Allocate(Map map,
+  V8_WARN_UNUSED_RESULT AllocationResult Allocate(Handle<Map> map,
                                                   AllocationType allocation);
 
   // Allocates a partial map for bootstrapping.
@@ -2045,6 +2097,7 @@ class Heap {
   // Stores the option corresponding to the object in the provided *option.
   bool IsRetainingPathTarget(HeapObject object, RetainingPathOption* option);
   void PrintRetainingPath(HeapObject object, RetainingPathOption option);
+  void UpdateRetainersAfterScavenge();
 
 #ifdef DEBUG
   V8_EXPORT_PRIVATE void IncrementObjectCounters();
@@ -2117,9 +2170,18 @@ class Heap {
   CodeLargeObjectSpace* code_lo_space_ = nullptr;
   NewLargeObjectSpace* new_lo_space_ = nullptr;
   ReadOnlySpace* read_only_space_ = nullptr;
+
+  OldSpace* shared_old_space_ = nullptr;
+  MapSpace* shared_map_space_ = nullptr;
+
+  std::unique_ptr<ConcurrentAllocator> shared_old_allocator_;
+  std::unique_ptr<ConcurrentAllocator> shared_map_allocator_;
+
   // Map from the space id to the space.
   Space* space_[LAST_SPACE + 1];
 
+  LocalHeap* main_thread_local_heap_ = nullptr;
+
   // List for tracking ArrayBufferExtensions
   ArrayBufferExtension* old_array_buffer_extensions_ = nullptr;
   ArrayBufferExtension* young_array_buffer_extensions_ = nullptr;
@@ -2189,7 +2251,9 @@ class Heap {
 
   // Weak list heads, threaded through the objects.
   // List heads are initialized lazily and contain the undefined_value at start.
-  Object native_contexts_list_;
+  // {native_contexts_list_} is an Address instead of an Object to allow the use
+  // of atomic accessors.
+  std::atomic<Address> native_contexts_list_;
   Object allocation_sites_list_;
   Object dirty_js_finalization_registries_list_;
   // Weak list tails.
@@ -2247,9 +2311,18 @@ class Heap {
   std::unique_ptr<LocalEmbedderHeapTracer> local_embedder_heap_tracer_;
   std::unique_ptr<MarkingBarrier> marking_barrier_;
 
+  // This object controls virtual space reserved for code on the V8 heap. This
+  // is only valid for 64-bit architectures where kRequiresCodeRange.
+  //
+  // Owned by the heap when !V8_COMPRESS_POINTERS_IN_SHARED_CAGE, otherwise is
+  // process-wide.
+  std::shared_ptr<CodeRange> code_range_;
+
   // The embedder owns the C++ heap.
   v8::CppHeap* cpp_heap_ = nullptr;
 
+  EmbedderRootsHandler* embedder_roots_handler_ = nullptr;
+
   StrongRootsEntry* strong_roots_head_ = nullptr;
   base::Mutex strong_roots_mutex_;
 
@@ -2278,6 +2351,9 @@ class Heap {
   // forwarding pointers.
   PretenuringFeedbackMap global_pretenuring_feedback_;
 
+  std::unique_ptr<GlobalHandleVector<AllocationSite>>
+      allocation_sites_to_pretenure_;
+
   char trace_ring_buffer_[kTraceRingBufferSize];
 
   // Used as boolean.
@@ -2335,14 +2411,15 @@ class Heap {
   int allocation_timeout_ = 0;
 #endif  // V8_ENABLE_ALLOCATION_TIMEOUT
 
-  std::map<HeapObject, HeapObject, Object::Comparer> retainer_;
-  std::map<HeapObject, Root, Object::Comparer> retaining_root_;
+  std::unordered_map<HeapObject, HeapObject, Object::Hasher> retainer_;
+  std::unordered_map<HeapObject, Root, Object::Hasher> retaining_root_;
   // If an object is retained by an ephemeron, then the retaining key of the
   // ephemeron is stored in this map.
-  std::map<HeapObject, HeapObject, Object::Comparer> ephemeron_retainer_;
+  std::unordered_map<HeapObject, HeapObject, Object::Hasher>
+      ephemeron_retainer_;
   // For each index inthe retaining_path_targets_ array this map
   // stores the option of the corresponding target.
-  std::map<int, RetainingPathOption> retaining_path_target_option_;
+  std::unordered_map<int, RetainingPathOption> retaining_path_target_option_;
 
   std::vector<HeapObjectAllocationTracker*> allocation_trackers_;
 
@@ -2367,6 +2444,7 @@ class Heap {
   friend class IncrementalMarking;
   friend class IncrementalMarkingJob;
   friend class LocalHeap;
+  friend class MarkingBarrier;
   friend class OldLargeObjectSpace;
   template <typename ConcreteVisitor, typename MarkingState>
   friend class MarkingVisitorBase;
@@ -2630,14 +2708,13 @@ class HeapObjectAllocationTracker {
 
 template <typename T>
 T ForwardingAddress(T heap_obj) {
-  MapWord map_word = heap_obj.map_word();
+  MapWord map_word = heap_obj.map_word(kRelaxedLoad);
 
   if (map_word.IsForwardingAddress()) {
     return T::cast(map_word.ToForwardingAddress());
   } else if (Heap::InFromPage(heap_obj)) {
     return T();
   } else {
-    // TODO(ulan): Support minor mark-compactor here.
     return heap_obj;
   }
 }
diff --git a/chromium/v8/src/heap/incremental-marking.cc b/chromium/v8/src/heap/incremental-marking.cc
index a0938359817..0c405c40bf8 100644
--- a/chromium/v8/src/heap/incremental-marking.cc
+++ b/chromium/v8/src/heap/incremental-marking.cc
@@ -39,9 +39,8 @@ void IncrementalMarking::Observer::Step(int bytes_allocated, Address addr,
                                         size_t size) {
   Heap* heap = incremental_marking_->heap();
   VMState<GC> state(heap->isolate());
-  RuntimeCallTimerScope runtime_timer(
-      heap->isolate(),
-      RuntimeCallCounterId::kGC_Custom_IncrementalMarkingObserver);
+  RCS_SCOPE(heap->isolate(),
+            RuntimeCallCounterId::kGC_Custom_IncrementalMarkingObserver);
   incremental_marking_->AdvanceOnAllocation();
   // AdvanceIncrementalMarkingOnAllocation can start incremental marking.
   incremental_marking_->EnsureBlackAllocated(addr, size);
@@ -108,20 +107,28 @@ class IncrementalMarkingRootMarkingVisitor : public RootVisitor {
 
   void VisitRootPointer(Root root, const char* description,
                         FullObjectSlot p) override {
+    DCHECK(!MapWord::IsPacked((*p).ptr()));
     MarkObjectByPointer(p);
   }
 
   void VisitRootPointers(Root root, const char* description,
                          FullObjectSlot start, FullObjectSlot end) override {
-    for (FullObjectSlot p = start; p < end; ++p) MarkObjectByPointer(p);
+    for (FullObjectSlot p = start; p < end; ++p) {
+      DCHECK(!MapWord::IsPacked((*p).ptr()));
+      MarkObjectByPointer(p);
+    }
   }
 
  private:
   void MarkObjectByPointer(FullObjectSlot p) {
-    Object obj = *p;
-    if (!obj.IsHeapObject()) return;
-
-    heap_->incremental_marking()->WhiteToGreyAndPush(HeapObject::cast(obj));
+    Object object = *p;
+    if (!object.IsHeapObject()) return;
+    DCHECK(!MapWord::IsPacked(object.ptr()));
+    HeapObject heap_object = HeapObject::cast(object);
+    BasicMemoryChunk* target_page =
+        BasicMemoryChunk::FromHeapObject(heap_object);
+    if (target_page->InSharedHeap()) return;
+    heap_->incremental_marking()->WhiteToGreyAndPush(heap_object);
   }
 
   Heap* heap_;
@@ -132,12 +139,14 @@ bool IncrementalMarking::WasActivated() { return was_activated_; }
 
 
 bool IncrementalMarking::CanBeActivated() {
-  // Only start incremental marking in a safe state: 1) when incremental
-  // marking is turned on, 2) when we are currently not in a GC, and
-  // 3) when we are currently not serializing or deserializing the heap.
+  // Only start incremental marking in a safe state:
+  //   1) when incremental marking is turned on
+  //   2) when we are currently not in a GC, and
+  //   3) when we are currently not serializing or deserializing the heap, and
+  //   4) not a shared heap.
   return FLAG_incremental_marking && heap_->gc_state() == Heap::NOT_IN_GC &&
          heap_->deserialization_complete() &&
-         !heap_->isolate()->serializer_enabled();
+         !heap_->isolate()->serializer_enabled() && !heap_->IsShared();
 }
 
 bool IncrementalMarking::IsBelowActivationThresholds() const {
@@ -147,6 +156,7 @@ bool IncrementalMarking::IsBelowActivationThresholds() const {
 
 void IncrementalMarking::Start(GarbageCollectionReason gc_reason) {
   DCHECK(!collector_->sweeping_in_progress());
+  DCHECK(!heap_->IsShared());
 
   if (FLAG_trace_incremental_marking) {
     const size_t old_generation_size_mb =
@@ -314,7 +324,9 @@ void IncrementalMarking::MarkRoots() {
 
   IncrementalMarkingRootMarkingVisitor visitor(this);
   heap_->IterateRoots(
-      &visitor, base::EnumSet<SkipRoot>{SkipRoot::kStack, SkipRoot::kWeak});
+      &visitor,
+      base::EnumSet<SkipRoot>{SkipRoot::kStack, SkipRoot::kMainThreadHandles,
+                              SkipRoot::kWeak});
 }
 
 bool IncrementalMarking::ShouldRetainMap(Map map, int age) {
@@ -356,6 +368,9 @@ void IncrementalMarking::RetainMaps() {
       if (!map_retaining_is_disabled && marking_state()->IsWhite(map)) {
         if (ShouldRetainMap(map, age)) {
           WhiteToGreyAndPush(map);
+          if (V8_UNLIKELY(FLAG_track_retaining_path)) {
+            heap_->AddRetainingRoot(Root::kRetainMaps, map);
+          }
         }
         Object prototype = map.prototype();
         if (age > 0 && prototype.IsHeapObject() &&
@@ -432,7 +447,7 @@ void IncrementalMarking::UpdateMarkingWorklistAfterScavenge() {
         DCHECK(obj.IsHeapObject());
         // Only pointers to from space have to be updated.
         if (Heap::InFromPage(obj)) {
-          MapWord map_word = obj.map_word();
+          MapWord map_word = obj.map_word(kRelaxedLoad);
           if (!map_word.IsForwardingAddress()) {
             // There may be objects on the marking deque that do not exist
             // anymore, e.g. left trimmed objects or objects from the root set
diff --git a/chromium/v8/src/heap/large-spaces.cc b/chromium/v8/src/heap/large-spaces.cc
index 5cbcc8620fb..4bb989fe9a8 100644
--- a/chromium/v8/src/heap/large-spaces.cc
+++ b/chromium/v8/src/heap/large-spaces.cc
@@ -5,6 +5,7 @@
 #include "src/heap/large-spaces.h"
 
 #include "src/base/platform/mutex.h"
+#include "src/base/sanitizer/msan.h"
 #include "src/common/globals.h"
 #include "src/execution/isolate.h"
 #include "src/heap/combined-heap.h"
@@ -18,7 +19,6 @@
 #include "src/heap/spaces-inl.h"
 #include "src/logging/log.h"
 #include "src/objects/objects-inl.h"
-#include "src/sanitizer/msan.h"
 #include "src/utils/ostreams.h"
 
 namespace v8 {
@@ -130,6 +130,7 @@ AllocationResult OldLargeObjectSpace::AllocateRaw(int object_size) {
 
 AllocationResult OldLargeObjectSpace::AllocateRaw(int object_size,
                                                   Executability executable) {
+  DCHECK(!FLAG_enable_third_party_heap);
   // Check if we want to force a GC before growing the old space further.
   // If so, fail the allocation.
   if (!heap()->CanExpandOldGeneration(object_size) ||
@@ -160,6 +161,7 @@ AllocationResult OldLargeObjectSpace::AllocateRaw(int object_size,
 
 AllocationResult OldLargeObjectSpace::AllocateRawBackground(
     LocalHeap* local_heap, int object_size) {
+  DCHECK(!FLAG_enable_third_party_heap);
   // Check if we want to force a GC before growing the old space further.
   // If so, fail the allocation.
   if (!heap()->CanExpandOldGenerationBackground(local_heap, object_size) ||
@@ -446,6 +448,7 @@ NewLargeObjectSpace::NewLargeObjectSpace(Heap* heap, size_t capacity)
       capacity_(capacity) {}
 
 AllocationResult NewLargeObjectSpace::AllocateRaw(int object_size) {
+  DCHECK(!FLAG_enable_third_party_heap);
   // Do not allocate more objects if promoting the existing object would exceed
   // the old generation capacity.
   if (!heap()->CanExpandOldGeneration(SizeOfObjects())) {
@@ -532,6 +535,7 @@ CodeLargeObjectSpace::CodeLargeObjectSpace(Heap* heap)
       chunk_map_(kInitialChunkMapCapacity) {}
 
 AllocationResult CodeLargeObjectSpace::AllocateRaw(int object_size) {
+  DCHECK(!FLAG_enable_third_party_heap);
   return OldLargeObjectSpace::AllocateRaw(object_size, EXECUTABLE);
 }
 
diff --git a/chromium/v8/src/heap/large-spaces.h b/chromium/v8/src/heap/large-spaces.h
index 8761b9949c4..1e53671a9b1 100644
--- a/chromium/v8/src/heap/large-spaces.h
+++ b/chromium/v8/src/heap/large-spaces.h
@@ -32,6 +32,7 @@ class LargePage : public MemoryChunk {
   static const int kMaxCodePageSize = 512 * MB;
 
   static LargePage* FromHeapObject(HeapObject o) {
+    DCHECK(!V8_ENABLE_THIRD_PARTY_HEAP_BOOL);
     return static_cast<LargePage*>(MemoryChunk::FromHeapObject(o));
   }
 
diff --git a/chromium/v8/src/heap/local-allocator.h b/chromium/v8/src/heap/local-allocator.h
index 9efbf3cf563..e64932b9fe9 100644
--- a/chromium/v8/src/heap/local-allocator.h
+++ b/chromium/v8/src/heap/local-allocator.h
@@ -36,7 +36,7 @@ class EvacuationAllocator {
     // Give back remaining LAB space if this EvacuationAllocator's new space LAB
     // sits right next to new space allocation top.
     const LinearAllocationArea info = new_space_lab_.CloseAndMakeIterable();
-    new_space_->MaybeFreeUnusedLab(info);
+    if (new_space_) new_space_->MaybeFreeUnusedLab(info);
   }
 
   inline AllocationResult Allocate(AllocationSpace space, int object_size,
diff --git a/chromium/v8/src/heap/local-heap-inl.h b/chromium/v8/src/heap/local-heap-inl.h
index fd0ec5a4499..e1333773dd3 100644
--- a/chromium/v8/src/heap/local-heap-inl.h
+++ b/chromium/v8/src/heap/local-heap-inl.h
@@ -18,6 +18,7 @@ namespace internal {
 AllocationResult LocalHeap::AllocateRaw(int size_in_bytes, AllocationType type,
                                         AllocationOrigin origin,
                                         AllocationAlignment alignment) {
+  DCHECK(!FLAG_enable_third_party_heap);
 #if DEBUG
   VerifyCurrent();
   DCHECK(AllowHandleAllocation::IsAllowed());
@@ -45,6 +46,7 @@ AllocationResult LocalHeap::AllocateRaw(int size_in_bytes, AllocationType type,
 Address LocalHeap::AllocateRawOrFail(int object_size, AllocationType type,
                                      AllocationOrigin origin,
                                      AllocationAlignment alignment) {
+  DCHECK(!FLAG_enable_third_party_heap);
   AllocationResult result = AllocateRaw(object_size, type, origin, alignment);
   if (!result.IsRetry()) return result.ToObject().address();
   return PerformCollectionAndAllocateAgain(object_size, type, origin,
diff --git a/chromium/v8/src/heap/local-heap.cc b/chromium/v8/src/heap/local-heap.cc
index 70cdbcc0d74..2c6724ba3a3 100644
--- a/chromium/v8/src/heap/local-heap.cc
+++ b/chromium/v8/src/heap/local-heap.cc
@@ -221,7 +221,7 @@ bool LocalHeap::TryPerformCollection() {
     heap_->CollectGarbageForBackground(this);
     return true;
   } else {
-    LocalHeap* main_thread = heap_->isolate()->main_thread_local_heap();
+    LocalHeap* main_thread = heap_->main_thread_local_heap();
     ThreadState current = main_thread->state_relaxed();
 
     while (true) {
diff --git a/chromium/v8/src/heap/mark-compact-inl.h b/chromium/v8/src/heap/mark-compact-inl.h
index a9db17f2aac..f28b9b5e849 100644
--- a/chromium/v8/src/heap/mark-compact-inl.h
+++ b/chromium/v8/src/heap/mark-compact-inl.h
@@ -205,9 +205,10 @@ void LiveObjectRange<mode>::iterator::AdvanceToNextValidObject() {
         // make sure that we skip all set bits in the black area until the
         // object ends.
         HeapObject black_object = HeapObject::FromAddress(addr);
-        Object map_object = ObjectSlot(addr).Acquire_Load();
+        Object map_object = black_object.map(kAcquireLoad);
         CHECK(map_object.IsMap());
         map = Map::cast(map_object);
+        DCHECK(map.IsMap());
         size = black_object.SizeFromMap(map);
         CHECK_LE(addr + size, chunk_->area_end());
         Address end = addr + size - kTaggedSize;
@@ -235,10 +236,11 @@ void LiveObjectRange<mode>::iterator::AdvanceToNextValidObject() {
           object = black_object;
         }
       } else if ((mode == kGreyObjects || mode == kAllLiveObjects)) {
-        Object map_object = ObjectSlot(addr).Acquire_Load();
+        object = HeapObject::FromAddress(addr);
+        Object map_object = object.map(kAcquireLoad);
         CHECK(map_object.IsMap());
         map = Map::cast(map_object);
-        object = HeapObject::FromAddress(addr);
+        DCHECK(map.IsMap());
         size = object.SizeFromMap(map);
         CHECK_LE(addr + size, chunk_->area_end());
       }
diff --git a/chromium/v8/src/heap/mark-compact.cc b/chromium/v8/src/heap/mark-compact.cc
index 951b49507ca..73eab9e2038 100644
--- a/chromium/v8/src/heap/mark-compact.cc
+++ b/chromium/v8/src/heap/mark-compact.cc
@@ -42,6 +42,7 @@
 #include "src/heap/worklist.h"
 #include "src/ic/stub-cache.h"
 #include "src/init/v8.h"
+#include "src/logging/tracing-flags.h"
 #include "src/objects/embedder-data-array-inl.h"
 #include "src/objects/foreign.h"
 #include "src/objects/hash-table-inl.h"
@@ -51,6 +52,7 @@
 #include "src/objects/slots-inl.h"
 #include "src/objects/transitions-inl.h"
 #include "src/tasks/cancelable-task.h"
+#include "src/tracing/tracing-category-observer.h"
 #include "src/utils/utils-inl.h"
 
 namespace v8 {
@@ -82,6 +84,7 @@ class MarkingVerifier : public ObjectVisitor, public RootVisitor {
   virtual ConcurrentBitmap<AccessMode::NON_ATOMIC>* bitmap(
       const MemoryChunk* chunk) = 0;
 
+  virtual void VerifyMap(Map map) = 0;
   virtual void VerifyPointers(ObjectSlot start, ObjectSlot end) = 0;
   virtual void VerifyPointers(MaybeObjectSlot start, MaybeObjectSlot end) = 0;
   virtual void VerifyRootPointers(FullObjectSlot start, FullObjectSlot end) = 0;
@@ -105,6 +108,8 @@ class MarkingVerifier : public ObjectVisitor, public RootVisitor {
     VerifyRootPointers(start, end);
   }
 
+  void VisitMapPointer(HeapObject object) override { VerifyMap(object.map()); }
+
   void VerifyRoots();
   void VerifyMarkingOnPage(const Page* page, Address start, Address end);
   void VerifyMarking(NewSpace* new_space);
@@ -146,6 +151,7 @@ void MarkingVerifier::VerifyMarkingOnPage(const Page* page, Address start,
 }
 
 void MarkingVerifier::VerifyMarking(NewSpace* space) {
+  if (!space) return;
   Address end = space->top();
   // The bottom position is at the start of its page. Allows us to use
   // page->area_start() as start of range on all pages.
@@ -168,6 +174,7 @@ void MarkingVerifier::VerifyMarking(PagedSpace* space) {
 }
 
 void MarkingVerifier::VerifyMarking(LargeObjectSpace* lo_space) {
+  if (!lo_space) return;
   LargeObjectSpaceObjectIterator it(lo_space);
   for (HeapObject obj = it.Next(); !obj.is_null(); obj = it.Next()) {
     if (IsBlackOrGrey(obj)) {
@@ -208,6 +215,8 @@ class FullMarkingVerifier : public MarkingVerifier {
     return marking_state_->IsBlackOrGrey(object);
   }
 
+  void VerifyMap(Map map) override { VerifyHeapObjectImpl(map); }
+
   void VerifyPointers(ObjectSlot start, ObjectSlot end) override {
     VerifyPointersImpl(start, end);
   }
@@ -235,6 +244,9 @@ class FullMarkingVerifier : public MarkingVerifier {
 
  private:
   V8_INLINE void VerifyHeapObjectImpl(HeapObject heap_object) {
+    if (!heap_->IsShared() &&
+        BasicMemoryChunk::FromHeapObject(heap_object)->InSharedHeap())
+      return;
     CHECK(marking_state_->IsBlackOrGrey(heap_object));
   }
 
@@ -271,11 +283,14 @@ class EvacuationVerifier : public ObjectVisitor, public RootVisitor {
     VerifyRootPointers(start, end);
   }
 
+  void VisitMapPointer(HeapObject object) override { VerifyMap(object.map()); }
+
  protected:
   explicit EvacuationVerifier(Heap* heap) : heap_(heap) {}
 
   inline Heap* heap() { return heap_; }
 
+  virtual void VerifyMap(Map map) = 0;
   virtual void VerifyPointers(ObjectSlot start, ObjectSlot end) = 0;
   virtual void VerifyPointers(MaybeObjectSlot start, MaybeObjectSlot end) = 0;
   virtual void VerifyRootPointers(FullObjectSlot start, FullObjectSlot end) = 0;
@@ -302,6 +317,7 @@ void EvacuationVerifier::VerifyEvacuationOnPage(Address start, Address end) {
 }
 
 void EvacuationVerifier::VerifyEvacuation(NewSpace* space) {
+  if (!space) return;
   PageRange range(space->first_allocatable_address(), space->top());
   for (auto it = range.begin(); it != range.end();) {
     Page* page = *(it++);
@@ -354,7 +370,7 @@ class FullEvacuationVerifier : public EvacuationVerifier {
       }
     }
   }
-
+  void VerifyMap(Map map) override { VerifyHeapObjectImpl(map); }
   void VerifyPointers(ObjectSlot start, ObjectSlot end) override {
     VerifyPointersImpl(start, end);
   }
@@ -408,6 +424,7 @@ MarkCompactCollector::MarkCompactCollector(Heap* heap)
 #ifdef DEBUG
       state_(IDLE),
 #endif
+      is_shared_heap_(heap->IsShared()),
       was_marked_incrementally_(false),
       evacuation_(false),
       compacting_(false),
@@ -548,6 +565,7 @@ void MarkCompactCollector::VerifyMarkbitsAreClean(PagedSpace* space) {
 }
 
 void MarkCompactCollector::VerifyMarkbitsAreClean(NewSpace* space) {
+  if (!space) return;
   for (Page* p : PageRange(space->first_allocatable_address(), space->top())) {
     CHECK(non_atomic_marking_state()->bitmap(p)->IsClean());
     CHECK_EQ(0, non_atomic_marking_state()->live_bytes(p));
@@ -555,6 +573,7 @@ void MarkCompactCollector::VerifyMarkbitsAreClean(NewSpace* space) {
 }
 
 void MarkCompactCollector::VerifyMarkbitsAreClean(LargeObjectSpace* space) {
+  if (!space) return;
   LargeObjectSpaceObjectIterator it(space);
   for (HeapObject obj = it.Next(); !obj.is_null(); obj = it.Next()) {
     CHECK(non_atomic_marking_state()->IsWhite(obj));
@@ -863,9 +882,14 @@ void MarkCompactCollector::Prepare() {
       [](LocalHeap* local_heap) { local_heap->FreeLinearAllocationArea(); });
 
   // All objects are guaranteed to be initialized in atomic pause
-  heap()->new_lo_space()->ResetPendingObject();
-  DCHECK_EQ(heap()->new_space()->top(),
-            heap()->new_space()->original_top_acquire());
+  if (heap()->new_lo_space()) {
+    heap()->new_lo_space()->ResetPendingObject();
+  }
+
+  if (heap()->new_space()) {
+    DCHECK_EQ(heap()->new_space()->top(),
+              heap()->new_space()->original_top_acquire());
+  }
 }
 
 void MarkCompactCollector::FinishConcurrentMarking() {
@@ -950,26 +974,34 @@ void MarkCompactCollector::SweepArrayBufferExtensions() {
 class MarkCompactCollector::RootMarkingVisitor final : public RootVisitor {
  public:
   explicit RootMarkingVisitor(MarkCompactCollector* collector)
-      : collector_(collector) {}
+      : collector_(collector), is_shared_heap_(collector->is_shared_heap()) {}
 
   void VisitRootPointer(Root root, const char* description,
                         FullObjectSlot p) final {
+    DCHECK(!MapWord::IsPacked(p.Relaxed_Load().ptr()));
     MarkObjectByPointer(root, p);
   }
 
   void VisitRootPointers(Root root, const char* description,
                          FullObjectSlot start, FullObjectSlot end) final {
-    for (FullObjectSlot p = start; p < end; ++p) MarkObjectByPointer(root, p);
+    for (FullObjectSlot p = start; p < end; ++p) {
+      MarkObjectByPointer(root, p);
+    }
   }
 
  private:
   V8_INLINE void MarkObjectByPointer(Root root, FullObjectSlot p) {
-    if (!(*p).IsHeapObject()) return;
-
-    collector_->MarkRootObject(root, HeapObject::cast(*p));
+    Object object = *p;
+    if (!object.IsHeapObject()) return;
+    HeapObject heap_object = HeapObject::cast(object);
+    BasicMemoryChunk* target_page =
+        BasicMemoryChunk::FromHeapObject(heap_object);
+    if (!is_shared_heap_ && target_page->InSharedHeap()) return;
+    collector_->MarkRootObject(root, heap_object);
   }
 
   MarkCompactCollector* const collector_;
+  const bool is_shared_heap_;
 };
 
 // This visitor is used to visit the body of special objects held alive by
@@ -991,8 +1023,12 @@ class MarkCompactCollector::CustomRootBodyMarkingVisitor final
     MarkObject(host, *p);
   }
 
+  void VisitMapPointer(HeapObject host) final { MarkObject(host, host.map()); }
+
   void VisitPointers(HeapObject host, ObjectSlot start, ObjectSlot end) final {
     for (ObjectSlot p = start; p < end; ++p) {
+      // The map slot should be handled in VisitMapPointer.
+      DCHECK_NE(host.map_slot(), p);
       DCHECK(!HasWeakHeapObjectTag(*p));
       MarkObject(host, *p);
     }
@@ -1145,6 +1181,7 @@ class RecordMigratedSlotVisitor : public ObjectVisitor {
   }
 
   inline void VisitPointer(HeapObject host, MaybeObjectSlot p) final {
+    DCHECK(!MapWord::IsPacked(p.Relaxed_Load().ptr()));
     RecordMigratedSlot(host, *p, p.address());
   }
 
@@ -1310,7 +1347,7 @@ class EvacuateVisitorBase : public HeapObjectVisitor {
       if (mode != MigrationMode::kFast)
         base->ExecuteMigrationObservers(dest, src, dst, size);
     }
-    src.set_map_word(MapWord::FromForwardingAddress(dst));
+    src.set_map_word(MapWord::FromForwardingAddress(dst), kRelaxedStore);
   }
 
   EvacuateVisitorBase(Heap* heap, EvacuationAllocator* local_allocator,
@@ -1439,7 +1476,8 @@ class EvacuateNewSpaceVisitor final : public EvacuateVisitorBase {
     if (map.visitor_id() == kVisitThinString) {
       HeapObject actual = ThinString::cast(object).unchecked_actual();
       if (MarkCompactCollector::IsOnEvacuationCandidate(actual)) return false;
-      object.set_map_word(MapWord::FromForwardingAddress(actual));
+      object.set_map_word(MapWord::FromForwardingAddress(actual),
+                          kRelaxedStore);
       return true;
     }
     // TODO(mlippautz): Handle ConsString.
@@ -1543,7 +1581,7 @@ class EvacuateOldSpaceVisitor final : public EvacuateVisitorBase {
     HeapObject target_object;
     if (TryEvacuateObject(Page::FromHeapObject(object)->owner_identity(),
                           object, size, &target_object)) {
-      DCHECK(object.map_word().IsForwardingAddress());
+      DCHECK(object.map_word(kRelaxedLoad).IsForwardingAddress());
       return true;
     }
     return false;
@@ -2483,9 +2521,6 @@ void MarkCompactCollector::ClearWeakReferences() {
 }
 
 void MarkCompactCollector::ClearJSWeakRefs() {
-  if (!FLAG_harmony_weak_refs) {
-    return;
-  }
   JSWeakRef weak_ref;
   while (weak_objects_.js_weak_refs.Pop(kMainThreadTask, &weak_ref)) {
     HeapObject target = HeapObject::cast(weak_ref.target());
@@ -2680,7 +2715,7 @@ static inline SlotCallbackResult UpdateSlot(TSlot slot,
                     std::is_same<TSlot, OffHeapObjectSlot>::value,
                 "Only [Full|OffHeap]ObjectSlot and [Full]MaybeObjectSlot are "
                 "expected here");
-  MapWord map_word = heap_obj.map_word();
+  MapWord map_word = heap_obj.map_word(kRelaxedLoad);
   if (map_word.IsForwardingAddress()) {
     DCHECK_IMPLIES(!Heap::InFromPage(heap_obj),
                    MarkCompactCollector::IsOnEvacuationCandidate(heap_obj) ||
@@ -2762,6 +2797,7 @@ class PointersUpdatingVisitor : public ObjectVisitor, public RootVisitor {
 
   void VisitRootPointer(Root root, const char* description,
                         FullObjectSlot p) override {
+    DCHECK(!MapWord::IsPacked(p.Relaxed_Load().ptr()));
     UpdateRootSlotInternal(cage_base_, p);
   }
 
@@ -2821,7 +2857,7 @@ class PointersUpdatingVisitor : public ObjectVisitor, public RootVisitor {
 
 static String UpdateReferenceInExternalStringTableEntry(Heap* heap,
                                                         FullObjectSlot p) {
-  MapWord map_word = HeapObject::cast(*p).map_word();
+  MapWord map_word = HeapObject::cast(*p).map_word(kRelaxedLoad);
 
   if (map_word.IsForwardingAddress()) {
     String new_string = String::cast(map_word.ToForwardingAddress());
@@ -2841,18 +2877,23 @@ static String UpdateReferenceInExternalStringTableEntry(Heap* heap,
 void MarkCompactCollector::EvacuatePrologue() {
   // New space.
   NewSpace* new_space = heap()->new_space();
-  // Append the list of new space pages to be processed.
-  for (Page* p :
-       PageRange(new_space->first_allocatable_address(), new_space->top())) {
-    new_space_evacuation_pages_.push_back(p);
-  }
-  new_space->Flip();
-  new_space->ResetLinearAllocationArea();
 
-  DCHECK_EQ(new_space->Size(), 0);
+  if (new_space) {
+    // Append the list of new space pages to be processed.
+    for (Page* p :
+         PageRange(new_space->first_allocatable_address(), new_space->top())) {
+      new_space_evacuation_pages_.push_back(p);
+    }
+    new_space->Flip();
+    new_space->ResetLinearAllocationArea();
+
+    DCHECK_EQ(new_space->Size(), 0);
+  }
 
-  heap()->new_lo_space()->Flip();
-  heap()->new_lo_space()->ResetPendingObject();
+  if (heap()->new_lo_space()) {
+    heap()->new_lo_space()->Flip();
+    heap()->new_lo_space()->ResetPendingObject();
+  }
 
   // Old space.
   DCHECK(old_space_evacuation_pages_.empty());
@@ -2863,18 +2904,27 @@ void MarkCompactCollector::EvacuatePrologue() {
 
 void MarkCompactCollector::EvacuateEpilogue() {
   aborted_evacuation_candidates_.clear();
+
   // New space.
-  heap()->new_space()->set_age_mark(heap()->new_space()->top());
-  DCHECK_IMPLIES(FLAG_always_promote_young_mc,
-                 heap()->new_space()->Size() == 0);
+  if (heap()->new_space()) {
+    heap()->new_space()->set_age_mark(heap()->new_space()->top());
+    DCHECK_IMPLIES(FLAG_always_promote_young_mc,
+                   heap()->new_space()->Size() == 0);
+  }
+
   // Deallocate unmarked large objects.
   heap()->lo_space()->FreeUnmarkedObjects();
   heap()->code_lo_space()->FreeUnmarkedObjects();
-  heap()->new_lo_space()->FreeUnmarkedObjects();
+  if (heap()->new_lo_space()) {
+    heap()->new_lo_space()->FreeUnmarkedObjects();
+  }
+
   // Old space. Deallocate evacuated candidate pages.
   ReleaseEvacuationCandidates();
+
   // Give pages that are queued to be freed back to the OS.
   heap()->memory_allocator()->unmapper()->FreeQueuedChunks();
+
 #ifdef DEBUG
   // Old-to-old slot sets must be empty after evacuation.
   for (Page* p : *heap()->old_space()) {
@@ -3274,19 +3324,21 @@ void MarkCompactCollector::EvacuatePagesInParallel() {
   }
 
   // Promote young generation large objects.
-  IncrementalMarking::NonAtomicMarkingState* marking_state =
-      heap()->incremental_marking()->non_atomic_marking_state();
-
-  for (auto it = heap()->new_lo_space()->begin();
-       it != heap()->new_lo_space()->end();) {
-    LargePage* current = *it;
-    it++;
-    HeapObject object = current->GetObject();
-    DCHECK(!marking_state->IsGrey(object));
-    if (marking_state->IsBlack(object)) {
-      heap_->lo_space()->PromoteNewLargeObject(current);
-      current->SetFlag(Page::PAGE_NEW_OLD_PROMOTION);
-      evacuation_items.emplace_back(ParallelWorkItem{}, current);
+  if (heap()->new_lo_space()) {
+    IncrementalMarking::NonAtomicMarkingState* marking_state =
+        heap()->incremental_marking()->non_atomic_marking_state();
+
+    for (auto it = heap()->new_lo_space()->begin();
+         it != heap()->new_lo_space()->end();) {
+      LargePage* current = *it;
+      it++;
+      HeapObject object = current->GetObject();
+      DCHECK(!marking_state->IsGrey(object));
+      if (marking_state->IsBlack(object)) {
+        heap_->lo_space()->PromoteNewLargeObject(current);
+        current->SetFlag(Page::PAGE_NEW_OLD_PROMOTION);
+        evacuation_items.emplace_back(ParallelWorkItem{}, current);
+      }
     }
   }
 
@@ -3314,7 +3366,7 @@ class EvacuationWeakObjectRetainer : public WeakObjectRetainer {
   Object RetainAs(Object object) override {
     if (object.IsHeapObject()) {
       HeapObject heap_object = HeapObject::cast(object);
-      MapWord map_word = heap_object.map_word();
+      MapWord map_word = heap_object.map_word(kRelaxedLoad);
       if (map_word.IsForwardingAddress()) {
         return map_word.ToForwardingAddress();
       }
@@ -3443,7 +3495,7 @@ void MarkCompactCollector::Evacuate() {
 
   UpdatePointersAfterEvacuation();
 
-  {
+  if (heap()->new_space()) {
     TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_EVACUATE_REBALANCE);
     if (!heap()->new_space()->Rebalance()) {
       heap()->FatalProcessOutOfMemory("NewSpace::Rebalance");
@@ -3645,7 +3697,7 @@ class RememberedSetUpdatingItem : public UpdatingItem {
       return REMOVE_SLOT;
     }
     if (Heap::InFromPage(heap_object)) {
-      MapWord map_word = heap_object.map_word();
+      MapWord map_word = heap_object.map_word(kRelaxedLoad);
       if (map_word.IsForwardingAddress()) {
         HeapObjectReference::Update(THeapObjectSlot(slot),
                                     map_word.ToForwardingAddress());
@@ -3815,6 +3867,8 @@ MarkCompactCollector::CreateRememberedSetUpdatingItem(
 
 int MarkCompactCollectorBase::CollectToSpaceUpdatingItems(
     std::vector<std::unique_ptr<UpdatingItem>>* items) {
+  if (!heap()->new_space()) return 0;
+
   // Seed to space pages.
   const Address space_start = heap()->new_space()->first_allocatable_address();
   const Address space_end = heap()->new_space()->top();
@@ -3877,7 +3931,7 @@ class EphemeronTableUpdatingItem : public UpdatingItem {
          it != heap_->ephemeron_remembered_set_.end();) {
       EphemeronHashTable table = it->first;
       auto& indices = it->second;
-      if (table.map_word().IsForwardingAddress()) {
+      if (table.map_word(kRelaxedLoad).IsForwardingAddress()) {
         // The table has moved, and RecordMigratedSlotVisitor::VisitEphemeron
         // inserts entries for the moved table into ephemeron_remembered_set_.
         it = heap_->ephemeron_remembered_set_.erase(it);
@@ -3890,7 +3944,7 @@ class EphemeronTableUpdatingItem : public UpdatingItem {
         HeapObjectSlot key_slot(table.RawFieldOfElementAt(
             EphemeronHashTable::EntryToIndex(InternalIndex(*iti))));
         HeapObject key = key_slot.ToHeapObject();
-        MapWord map_word = key.map_word();
+        MapWord map_word = key.map_word(kRelaxedLoad);
         if (map_word.IsForwardingAddress()) {
           key = map_word.ToForwardingAddress();
           key_slot.StoreHeapObject(key);
@@ -4145,6 +4199,8 @@ class YoungGenerationMarkingVerifier : public MarkingVerifier {
   }
 
  protected:
+  void VerifyMap(Map map) override { VerifyHeapObjectImpl(map); }
+
   void VerifyPointers(ObjectSlot start, ObjectSlot end) override {
     VerifyPointersImpl(start, end);
   }
@@ -4213,7 +4269,7 @@ class YoungGenerationEvacuationVerifier : public EvacuationVerifier {
       }
     }
   }
-
+  void VerifyMap(Map map) override { VerifyHeapObjectImpl(map); }
   void VerifyPointers(ObjectSlot start, ObjectSlot end) override {
     VerifyPointersImpl(start, end);
   }
@@ -4482,6 +4538,7 @@ class MinorMarkCompactCollector::RootMarkingVisitor : public RootVisitor {
   void VisitRootPointers(Root root, const char* description,
                          FullObjectSlot start, FullObjectSlot end) final {
     for (FullObjectSlot p = start; p < end; ++p) {
+      DCHECK(!MapWord::IsPacked((*p).ptr()));
       MarkObjectByPointer(p);
     }
   }
@@ -4539,7 +4596,8 @@ void MinorMarkCompactCollector::CollectGarbage() {
     }
     // Since we promote all surviving large objects immediatelly, all remaining
     // large objects must be dead.
-    // TODO(ulan): Don't free all as soon as we have an intermediate generation.
+    // TODO(v8:11685): Don't free all as soon as we have an intermediate
+    // generation.
     heap()->new_lo_space()->FreeDeadObjects([](HeapObject) { return true; });
   }
 
@@ -4572,7 +4630,7 @@ void MinorMarkCompactCollector::MakeIterable(
       p->heap()->CreateFillerObjectAt(free_start, static_cast<int>(size),
                                       ClearRecordedSlots::kNo);
     }
-    Map map = object.synchronized_map();
+    Map map = object.map(kAcquireLoad);
     int size = object.SizeFromMap(map);
     free_start = free_end + size;
   }
@@ -5027,7 +5085,7 @@ void MinorMarkCompactCollector::TraceFragmentation() {
           free_bytes_index++;
         }
       }
-      Map map = object.synchronized_map();
+      Map map = object.map(kAcquireLoad);
       int size = object.SizeFromMap(map);
       live_bytes += size;
       free_start = free_end + size;
diff --git a/chromium/v8/src/heap/mark-compact.h b/chromium/v8/src/heap/mark-compact.h
index 733588ae80a..035fb37064a 100644
--- a/chromium/v8/src/heap/mark-compact.h
+++ b/chromium/v8/src/heap/mark-compact.h
@@ -506,6 +506,7 @@ class MarkCompactCollector final : public MarkCompactCollectorBase {
   void RecordLiveSlotsOnPage(Page* page);
 
   bool is_compacting() const { return compacting_; }
+  bool is_shared_heap() const { return is_shared_heap_; }
 
   // Ensures that sweeping is finished.
   //
@@ -605,11 +606,11 @@ class MarkCompactCollector final : public MarkCompactCollectorBase {
 
   void MarkLiveObjects() override;
 
-  // Marks the object black and adds it to the marking work list.
+  // Marks the object grey and adds it to the marking work list.
   // This is for non-incremental marking only.
   V8_INLINE void MarkObject(HeapObject host, HeapObject obj);
 
-  // Marks the object black and adds it to the marking work list.
+  // Marks the object grey and adds it to the marking work list.
   // This is for non-incremental marking only.
   V8_INLINE void MarkRootObject(Root root, HeapObject obj);
 
@@ -743,6 +744,8 @@ class MarkCompactCollector final : public MarkCompactCollectorBase {
   CollectorState state_;
 #endif
 
+  const bool is_shared_heap_;
+
   bool was_marked_incrementally_;
 
   bool evacuation_;
diff --git a/chromium/v8/src/heap/marking-barrier-inl.h b/chromium/v8/src/heap/marking-barrier-inl.h
index 56bd7efda23..d03bdcb0f7a 100644
--- a/chromium/v8/src/heap/marking-barrier-inl.h
+++ b/chromium/v8/src/heap/marking-barrier-inl.h
@@ -28,8 +28,14 @@ bool MarkingBarrier::MarkValue(HeapObject host, HeapObject value) {
     // visits the host object.
     return false;
   }
-  if (WhiteToGreyAndPush(value) && is_main_thread_barrier_) {
-    incremental_marking_->RestartIfNotMarking();
+  if (WhiteToGreyAndPush(value)) {
+    if (is_main_thread_barrier_) {
+      incremental_marking_->RestartIfNotMarking();
+    }
+
+    if (V8_UNLIKELY(FLAG_track_retaining_path)) {
+      heap_->AddRetainingRoot(Root::kWriteBarrier, value);
+    }
   }
   return true;
 }
diff --git a/chromium/v8/src/heap/marking-visitor-inl.h b/chromium/v8/src/heap/marking-visitor-inl.h
index 55c37e535bd..14e8a4d3552 100644
--- a/chromium/v8/src/heap/marking-visitor-inl.h
+++ b/chromium/v8/src/heap/marking-visitor-inl.h
@@ -22,6 +22,7 @@ namespace internal {
 template <typename ConcreteVisitor, typename MarkingState>
 void MarkingVisitorBase<ConcreteVisitor, MarkingState>::MarkObject(
     HeapObject host, HeapObject object) {
+  DCHECK(ReadOnlyHeap::Contains(object) || heap_->Contains(object));
   concrete_visitor()->SynchronizePageAccess(object);
   if (concrete_visitor()->marking_state()->WhiteToGrey(object)) {
     local_marking_worklists_->Push(object);
@@ -38,6 +39,9 @@ template <typename ConcreteVisitor, typename MarkingState>
 template <typename THeapObjectSlot>
 void MarkingVisitorBase<ConcreteVisitor, MarkingState>::ProcessStrongHeapObject(
     HeapObject host, THeapObjectSlot slot, HeapObject heap_object) {
+  concrete_visitor()->SynchronizePageAccess(heap_object);
+  BasicMemoryChunk* target_page = BasicMemoryChunk::FromHeapObject(heap_object);
+  if (!is_shared_heap_ && target_page->InSharedHeap()) return;
   MarkObject(host, heap_object);
   concrete_visitor()->RecordSlot(host, slot, heap_object);
 }
@@ -355,7 +359,7 @@ int MarkingVisitorBase<ConcreteVisitor, MarkingState>::MarkDescriptorArrayBlack(
     DescriptorArray descriptors) {
   concrete_visitor()->marking_state()->WhiteToGrey(descriptors);
   if (concrete_visitor()->marking_state()->GreyToBlack(descriptors)) {
-    VisitPointer(descriptors, descriptors.map_slot());
+    VisitMapPointer(descriptors);
     VisitPointers(descriptors, descriptors.GetFirstPointerSlot(),
                   descriptors.GetDescriptorSlot(0));
     return DescriptorArray::BodyDescriptor::SizeOf(descriptors.map(),
diff --git a/chromium/v8/src/heap/marking-visitor.h b/chromium/v8/src/heap/marking-visitor.h
index 45dda338d01..f8795aadfd5 100644
--- a/chromium/v8/src/heap/marking-visitor.h
+++ b/chromium/v8/src/heap/marking-visitor.h
@@ -114,7 +114,8 @@ class MarkingVisitorBase : public HeapVisitor<int, ConcreteVisitor> {
         mark_compact_epoch_(mark_compact_epoch),
         bytecode_flush_mode_(bytecode_flush_mode),
         is_embedder_tracing_enabled_(is_embedder_tracing_enabled),
-        is_forced_gc_(is_forced_gc) {}
+        is_forced_gc_(is_forced_gc),
+        is_shared_heap_(heap->IsShared()) {}
 
   V8_INLINE int VisitBytecodeArray(Map map, BytecodeArray object);
   V8_INLINE int VisitDescriptorArray(Map map, DescriptorArray object);
@@ -133,6 +134,11 @@ class MarkingVisitorBase : public HeapVisitor<int, ConcreteVisitor> {
   V8_INLINE int VisitWeakCell(Map map, WeakCell object);
 
   // ObjectVisitor overrides.
+  void VisitMapPointer(HeapObject host) final {
+    // Note that we are skipping the recording the slot because map objects
+    // can't move, so this is safe (see ProcessStrongHeapObject for comparison)
+    MarkObject(host, HeapObject::cast(host.map()));
+  }
   V8_INLINE void VisitPointer(HeapObject host, ObjectSlot p) final {
     VisitPointersImpl(host, p, p + 1);
   }
@@ -196,6 +202,7 @@ class MarkingVisitorBase : public HeapVisitor<int, ConcreteVisitor> {
   const BytecodeFlushMode bytecode_flush_mode_;
   const bool is_embedder_tracing_enabled_;
   const bool is_forced_gc_;
+  const bool is_shared_heap_;
 };
 
 }  // namespace internal
diff --git a/chromium/v8/src/heap/memory-allocator.cc b/chromium/v8/src/heap/memory-allocator.cc
index b5bccb879d0..5783f2d04b9 100644
--- a/chromium/v8/src/heap/memory-allocator.cc
+++ b/chromium/v8/src/heap/memory-allocator.cc
@@ -20,118 +20,23 @@
 namespace v8 {
 namespace internal {
 
-static base::LazyInstance<CodeRangeAddressHint>::type code_range_address_hint =
-    LAZY_INSTANCE_INITIALIZER;
-
-namespace {
-void FunctionInStaticBinaryForAddressHint() {}
-}  // namespace
-
-Address CodeRangeAddressHint::GetAddressHint(size_t code_range_size) {
-  base::MutexGuard guard(&mutex_);
-  auto it = recently_freed_.find(code_range_size);
-  if (it == recently_freed_.end() || it->second.empty()) {
-    return FUNCTION_ADDR(&FunctionInStaticBinaryForAddressHint);
-  }
-  Address result = it->second.back();
-  it->second.pop_back();
-  return result;
-}
-
-void CodeRangeAddressHint::NotifyFreedCodeRange(Address code_range_start,
-                                                size_t code_range_size) {
-  base::MutexGuard guard(&mutex_);
-  recently_freed_[code_range_size].push_back(code_range_start);
-}
-
 // -----------------------------------------------------------------------------
 // MemoryAllocator
 //
 
-MemoryAllocator::MemoryAllocator(Isolate* isolate, size_t capacity,
-                                 size_t code_range_size)
+MemoryAllocator::MemoryAllocator(Isolate* isolate,
+                                 v8::PageAllocator* code_page_allocator,
+                                 size_t capacity)
     : isolate_(isolate),
       data_page_allocator_(isolate->page_allocator()),
-      code_page_allocator_(nullptr),
+      code_page_allocator_(code_page_allocator),
       capacity_(RoundUp(capacity, Page::kPageSize)),
       size_(0),
       size_executable_(0),
       lowest_ever_allocated_(static_cast<Address>(-1ll)),
       highest_ever_allocated_(kNullAddress),
       unmapper_(isolate->heap(), this) {
-  InitializeCodePageAllocator(data_page_allocator_, code_range_size);
-}
-
-void MemoryAllocator::InitializeCodePageAllocator(
-    v8::PageAllocator* page_allocator, size_t requested) {
-  DCHECK_NULL(code_page_allocator_instance_.get());
-
-  code_page_allocator_ = page_allocator;
-
-  if (requested == 0) {
-    if (!isolate_->RequiresCodeRange()) return;
-    // When a target requires the code range feature, we put all code objects
-    // in a kMaximalCodeRangeSize range of virtual address space, so that
-    // they can call each other with near calls.
-    requested = kMaximalCodeRangeSize;
-  } else if (requested <= kMinimumCodeRangeSize) {
-    requested = kMinimumCodeRangeSize;
-  }
-
-  const size_t reserved_area =
-      kReservedCodeRangePages * MemoryAllocator::GetCommitPageSize();
-  if (requested < (kMaximalCodeRangeSize - reserved_area)) {
-    requested += RoundUp(reserved_area, MemoryChunk::kPageSize);
-    // Fullfilling both reserved pages requirement and huge code area
-    // alignments is not supported (requires re-implementation).
-    DCHECK_LE(kMinExpectedOSPageSize, page_allocator->AllocatePageSize());
-  }
-  DCHECK(!isolate_->RequiresCodeRange() || requested <= kMaximalCodeRangeSize);
-
-  Address hint =
-      RoundDown(code_range_address_hint.Pointer()->GetAddressHint(requested),
-                page_allocator->AllocatePageSize());
-  VirtualMemory reservation(
-      page_allocator, requested, reinterpret_cast<void*>(hint),
-      std::max(kMinExpectedOSPageSize, page_allocator->AllocatePageSize()));
-  if (!reservation.IsReserved()) {
-    V8::FatalProcessOutOfMemory(isolate_,
-                                "CodeRange setup: allocate virtual memory");
-  }
-  code_range_ = reservation.region();
-  isolate_->AddCodeRange(code_range_.begin(), code_range_.size());
-
-  // We are sure that we have mapped a block of requested addresses.
-  DCHECK_GE(reservation.size(), requested);
-  Address base = reservation.address();
-
-  // On some platforms, specifically Win64, we need to reserve some pages at
-  // the beginning of an executable space. See
-  //   https://cs.chromium.org/chromium/src/components/crash/content/
-  //     app/crashpad_win.cc?rcl=fd680447881449fba2edcf0589320e7253719212&l=204
-  // for details.
-  if (reserved_area > 0) {
-    if (!reservation.SetPermissions(base, reserved_area,
-                                    PageAllocator::kReadWrite))
-      V8::FatalProcessOutOfMemory(isolate_, "CodeRange setup: set permissions");
-
-    base += reserved_area;
-  }
-  Address aligned_base = RoundUp(base, MemoryChunk::kAlignment);
-  size_t size =
-      RoundDown(reservation.size() - (aligned_base - base) - reserved_area,
-                MemoryChunk::kPageSize);
-  DCHECK(IsAligned(aligned_base, kMinExpectedOSPageSize));
-
-  LOG(isolate_,
-      NewEvent("CodeRange", reinterpret_cast<void*>(reservation.address()),
-               requested));
-
-  code_reservation_ = std::move(reservation);
-  code_page_allocator_instance_ = std::make_unique<base::BoundedPageAllocator>(
-      page_allocator, aligned_base, size,
-      static_cast<size_t>(MemoryChunk::kAlignment));
-  code_page_allocator_ = code_page_allocator_instance_.get();
+  DCHECK_NOT_NULL(code_page_allocator);
 }
 
 void MemoryAllocator::TearDown() {
@@ -147,13 +52,6 @@ void MemoryAllocator::TearDown() {
     last_chunk_.Free();
   }
 
-  if (code_page_allocator_instance_.get()) {
-    DCHECK(!code_range_.is_empty());
-    code_range_address_hint.Pointer()->NotifyFreedCodeRange(code_range_.begin(),
-                                                            code_range_.size());
-    code_range_ = base::AddressRegion();
-    code_page_allocator_instance_.reset();
-  }
   code_page_allocator_ = nullptr;
   data_page_allocator_ = nullptr;
 }
diff --git a/chromium/v8/src/heap/memory-allocator.h b/chromium/v8/src/heap/memory-allocator.h
index 179877e753a..d405aefa53b 100644
--- a/chromium/v8/src/heap/memory-allocator.h
+++ b/chromium/v8/src/heap/memory-allocator.h
@@ -17,6 +17,7 @@
 #include "src/base/macros.h"
 #include "src/base/platform/mutex.h"
 #include "src/base/platform/semaphore.h"
+#include "src/heap/code-range.h"
 #include "src/heap/heap.h"
 #include "src/heap/memory-chunk.h"
 #include "src/heap/spaces.h"
@@ -30,27 +31,6 @@ class Heap;
 class Isolate;
 class ReadOnlyPage;
 
-// The process-wide singleton that keeps track of code range regions with the
-// intention to reuse free code range regions as a workaround for CFG memory
-// leaks (see crbug.com/870054).
-class CodeRangeAddressHint {
- public:
-  // Returns the most recently freed code range start address for the given
-  // size. If there is no such entry, then a random address is returned.
-  V8_EXPORT_PRIVATE Address GetAddressHint(size_t code_range_size);
-
-  V8_EXPORT_PRIVATE void NotifyFreedCodeRange(Address code_range_start,
-                                              size_t code_range_size);
-
- private:
-  base::Mutex mutex_;
-  // A map from code range size to an array of recently freed code range
-  // addresses. There should be O(1) different code range sizes.
-  // The length of each array is limited by the peak number of code ranges,
-  // which should be also O(1).
-  std::unordered_map<size_t, std::vector<Address>> recently_freed_;
-};
-
 // ----------------------------------------------------------------------------
 // A space acquires chunks of memory from the operating system. The memory
 // allocator allocates and deallocates pages for the paged heap spaces and large
@@ -172,8 +152,9 @@ class MemoryAllocator {
   V8_EXPORT_PRIVATE static base::AddressRegion ComputeDiscardMemoryArea(
       Address addr, size_t size);
 
-  V8_EXPORT_PRIVATE MemoryAllocator(Isolate* isolate, size_t max_capacity,
-                                    size_t code_range_size);
+  V8_EXPORT_PRIVATE MemoryAllocator(Isolate* isolate,
+                                    v8::PageAllocator* code_page_allocator,
+                                    size_t max_capacity);
 
   V8_EXPORT_PRIVATE void TearDown();
 
@@ -283,17 +264,6 @@ class MemoryAllocator {
                                     : data_page_allocator_;
   }
 
-  // A region of memory that may contain executable code including reserved
-  // OS page with read-write access in the beginning.
-  const base::AddressRegion& code_range() const {
-    // |code_range_| >= |optional RW pages| + |code_page_allocator_instance_|
-    DCHECK_IMPLIES(!code_range_.is_empty(), code_page_allocator_instance_);
-    DCHECK_IMPLIES(!code_range_.is_empty(),
-                   code_range_.contains(code_page_allocator_instance_->begin(),
-                                        code_page_allocator_instance_->size()));
-    return code_range_;
-  }
-
   Unmapper* unmapper() { return &unmapper_; }
 
   // Performs all necessary bookkeeping to free the memory, but does not free
@@ -306,9 +276,6 @@ class MemoryAllocator {
   void RegisterReadOnlyMemory(ReadOnlyPage* page);
 
  private:
-  void InitializeCodePageAllocator(v8::PageAllocator* page_allocator,
-                                   size_t requested);
-
   // PreFreeMemory logically frees the object, i.e., it unregisters the
   // memory, logs a delete event and adds the chunk to remembered unmapped
   // pages.
@@ -360,10 +327,6 @@ class MemoryAllocator {
 
   Isolate* isolate_;
 
-  // This object controls virtual space reserved for code on the V8 heap. This
-  // is only valid for 64-bit architectures where kRequiresCodeRange.
-  VirtualMemory code_reservation_;
-
   // Page allocator used for allocating data pages. Depending on the
   // configuration it may be a page allocator instance provided by
   // v8::Platform or a BoundedPageAllocator (when pointer compression is
@@ -371,29 +334,12 @@ class MemoryAllocator {
   v8::PageAllocator* data_page_allocator_;
 
   // Page allocator used for allocating code pages. Depending on the
-  // configuration it may be a page allocator instance provided by
-  // v8::Platform or a BoundedPageAllocator (when pointer compression is
-  // enabled or on those 64-bit architectures where pc-relative 32-bit
+  // configuration it may be a page allocator instance provided by v8::Platform
+  // or a BoundedPageAllocator from Heap::code_range_ (when pointer compression
+  // is enabled or on those 64-bit architectures where pc-relative 32-bit
   // displacement can be used for call and jump instructions).
   v8::PageAllocator* code_page_allocator_;
 
-  // A part of the |code_reservation_| that may contain executable code
-  // including reserved page with read-write access in the beginning.
-  // See details below.
-  base::AddressRegion code_range_;
-
-  // This unique pointer owns the instance of bounded code allocator
-  // that controls executable pages allocation. It does not control the
-  // optionally existing page in the beginning of the |code_range_|.
-  // So, summarizing all above, the following conditions hold:
-  // 1) |code_reservation_| >= |code_range_|
-  // 2) |code_range_| >= |optional RW pages| +
-  // |code_page_allocator_instance_|. 3) |code_reservation_| is
-  // AllocatePageSize()-aligned 4) |code_page_allocator_instance_| is
-  // MemoryChunk::kAlignment-aligned 5) |code_range_| is
-  // CommitPageSize()-aligned
-  std::unique_ptr<base::BoundedPageAllocator> code_page_allocator_instance_;
-
   // Maximum space size in bytes.
   size_t capacity_;
 
diff --git a/chromium/v8/src/heap/memory-chunk.cc b/chromium/v8/src/heap/memory-chunk.cc
index c2355c6b84b..4d16da707f9 100644
--- a/chromium/v8/src/heap/memory-chunk.cc
+++ b/chromium/v8/src/heap/memory-chunk.cc
@@ -161,6 +161,9 @@ MemoryChunk* MemoryChunk::Initialize(BasicMemoryChunk* basic_chunk, Heap* heap,
 
   chunk->possibly_empty_buckets_.Initialize();
 
+  // All pages of a shared heap need to be marked with this flag.
+  if (heap->IsShared()) chunk->SetFlag(IN_SHARED_HEAP);
+
 #ifdef V8_ENABLE_CONSERVATIVE_STACK_SCANNING
   chunk->object_start_bitmap_ = ObjectStartBitmap(chunk->area_start());
 #endif
diff --git a/chromium/v8/src/heap/memory-measurement.cc b/chromium/v8/src/heap/memory-measurement.cc
index ab491e19a6e..491fe3102ab 100644
--- a/chromium/v8/src/heap/memory-measurement.cc
+++ b/chromium/v8/src/heap/memory-measurement.cc
@@ -336,7 +336,7 @@ std::unique_ptr<v8::MeasureMemoryDelegate> MemoryMeasurement::DefaultDelegate(
 
 bool NativeContextInferrer::InferForContext(Isolate* isolate, Context context,
                                             Address* native_context) {
-  Map context_map = context.synchronized_map();
+  Map context_map = context.map(kAcquireLoad);
   Object maybe_native_context =
       TaggedField<Object, Map::kConstructorOrBackPointerOrNativeContextOffset>::
           Acquire_Load(isolate, context_map);
diff --git a/chromium/v8/src/heap/new-spaces-inl.h b/chromium/v8/src/heap/new-spaces-inl.h
index ffd5d8cfd7e..98626260e11 100644
--- a/chromium/v8/src/heap/new-spaces-inl.h
+++ b/chromium/v8/src/heap/new-spaces-inl.h
@@ -5,12 +5,12 @@
 #ifndef V8_HEAP_NEW_SPACES_INL_H_
 #define V8_HEAP_NEW_SPACES_INL_H_
 
+#include "src/base/sanitizer/msan.h"
 #include "src/common/globals.h"
 #include "src/heap/heap.h"
 #include "src/heap/new-spaces.h"
 #include "src/heap/spaces-inl.h"
 #include "src/objects/tagged-impl.h"
-#include "src/sanitizer/msan.h"
 
 namespace v8 {
 namespace internal {
@@ -87,6 +87,8 @@ HeapObject SemiSpaceObjectIterator::Next() {
 AllocationResult NewSpace::AllocateRaw(int size_in_bytes,
                                        AllocationAlignment alignment,
                                        AllocationOrigin origin) {
+  DCHECK(!FLAG_single_generation);
+  DCHECK(!FLAG_enable_third_party_heap);
 #if DEBUG
   VerifyTop();
 #endif
@@ -110,7 +112,7 @@ AllocationResult NewSpace::AllocateFastUnaligned(int size_in_bytes,
                                                  AllocationOrigin origin) {
   Address top = allocation_info_.top();
   if (allocation_info_.limit() < top + size_in_bytes) {
-    return AllocationResult::Retry();
+    return AllocationResult::Retry(NEW_SPACE);
   }
 
   HeapObject obj = HeapObject::FromAddress(top);
@@ -135,7 +137,7 @@ AllocationResult NewSpace::AllocateFastAligned(
 
   if (allocation_info_.limit() - top <
       static_cast<uintptr_t>(aligned_size_in_bytes)) {
-    return AllocationResult::Retry();
+    return AllocationResult::Retry(NEW_SPACE);
   }
 
   HeapObject obj = HeapObject::FromAddress(top);
diff --git a/chromium/v8/src/heap/new-spaces.cc b/chromium/v8/src/heap/new-spaces.cc
index 029b77beb4d..8486c7bcc44 100644
--- a/chromium/v8/src/heap/new-spaces.cc
+++ b/chromium/v8/src/heap/new-spaces.cc
@@ -4,6 +4,7 @@
 
 #include "src/heap/new-spaces.h"
 
+#include "src/common/globals.h"
 #include "src/heap/array-buffer-sweeper.h"
 #include "src/heap/heap-inl.h"
 #include "src/heap/incremental-marking.h"
@@ -628,8 +629,9 @@ AllocationResult NewSpace::AllocateRawSlow(int size_in_bytes,
 
 AllocationResult NewSpace::AllocateRawUnaligned(int size_in_bytes,
                                                 AllocationOrigin origin) {
+  DCHECK(!FLAG_enable_third_party_heap);
   if (!EnsureAllocation(size_in_bytes, kWordAligned)) {
-    return AllocationResult::Retry();
+    return AllocationResult::Retry(NEW_SPACE);
   }
 
   DCHECK_EQ(allocation_info_.start(), allocation_info_.top());
@@ -646,8 +648,9 @@ AllocationResult NewSpace::AllocateRawUnaligned(int size_in_bytes,
 AllocationResult NewSpace::AllocateRawAligned(int size_in_bytes,
                                               AllocationAlignment alignment,
                                               AllocationOrigin origin) {
+  DCHECK(!FLAG_enable_third_party_heap);
   if (!EnsureAllocation(size_in_bytes, alignment)) {
-    return AllocationResult::Retry();
+    return AllocationResult::Retry(NEW_SPACE);
   }
 
   DCHECK_EQ(allocation_info_.start(), allocation_info_.top());
@@ -741,9 +744,11 @@ void NewSpace::Verify(Isolate* isolate) {
     CHECK_EQ(external_space_bytes[t], ExternalBackingStoreBytes(t));
   }
 
+  if (!FLAG_concurrent_array_buffer_sweeping) {
     size_t bytes = heap()->array_buffer_sweeper()->young().BytesSlow();
     CHECK_EQ(bytes,
              ExternalBackingStoreBytes(ExternalBackingStoreType::kArrayBuffer));
+  }
 
   // Check semi-spaces.
   CHECK_EQ(from_space_.id(), kFromSpace);
diff --git a/chromium/v8/src/heap/object-stats.cc b/chromium/v8/src/heap/object-stats.cc
index 86b2e6a2c40..5e0074e47f7 100644
--- a/chromium/v8/src/heap/object-stats.cc
+++ b/chromium/v8/src/heap/object-stats.cc
@@ -74,7 +74,7 @@ class FieldStatsCollector : public ObjectVisitor {
       raw_fields_count_in_object -= kDoubleSize / kTaggedSize;
       *boxed_double_fields_count_ += 1;
     } else if (host.IsSeqString()) {
-      int string_data = SeqString::cast(host).synchronized_length() *
+      int string_data = SeqString::cast(host).length(kAcquireLoad) *
                         (String::cast(host).IsOneByteRepresentation() ? 1 : 2) /
                         kTaggedSize;
       DCHECK_LE(string_data, raw_fields_count_in_object);
diff --git a/chromium/v8/src/heap/objects-visiting-inl.h b/chromium/v8/src/heap/objects-visiting-inl.h
index 37ecd50c8df..8aac430ddbd 100644
--- a/chromium/v8/src/heap/objects-visiting-inl.h
+++ b/chromium/v8/src/heap/objects-visiting-inl.h
@@ -76,8 +76,9 @@ ResultType HeapVisitor<ResultType, ConcreteVisitor>::Visit(Map map,
 template <typename ResultType, typename ConcreteVisitor>
 void HeapVisitor<ResultType, ConcreteVisitor>::VisitMapPointer(
     HeapObject host) {
-  DCHECK(!host.map_word().IsForwardingAddress());
-  static_cast<ConcreteVisitor*>(this)->VisitPointer(host, host.map_slot());
+  DCHECK(!host.map_word(kRelaxedLoad).IsForwardingAddress());
+  if (!static_cast<ConcreteVisitor*>(this)->ShouldVisitMapPointer()) return;
+  static_cast<ConcreteVisitor*>(this)->VisitMapPointer(host);
 }
 
 #define VISIT(TypeName)                                                        \
@@ -167,7 +168,7 @@ ResultType HeapVisitor<ResultType, ConcreteVisitor>::VisitFreeSpace(
   if (visitor->ShouldVisitMapPointer()) {
     visitor->VisitMapPointer(object);
   }
-  return static_cast<ResultType>(object.size());
+  return static_cast<ResultType>(object.size(kRelaxedLoad));
 }
 
 template <typename ConcreteVisitor>
diff --git a/chromium/v8/src/heap/objects-visiting.h b/chromium/v8/src/heap/objects-visiting.h
index 9f133d6cfab..7ea322dfb99 100644
--- a/chromium/v8/src/heap/objects-visiting.h
+++ b/chromium/v8/src/heap/objects-visiting.h
@@ -52,8 +52,11 @@ namespace internal {
   V(SyntheticModule)                    \
   V(TransitionArray)                    \
   IF_WASM(V, WasmArray)                 \
+  IF_WASM(V, WasmExportedFunctionData)  \
+  IF_WASM(V, WasmFunctionData)          \
   IF_WASM(V, WasmIndirectFunctionTable) \
   IF_WASM(V, WasmInstanceObject)        \
+  IF_WASM(V, WasmJSFunctionData)        \
   IF_WASM(V, WasmStruct)                \
   IF_WASM(V, WasmTypeInfo)
 
@@ -78,6 +81,8 @@ class HeapVisitor : public ObjectVisitor {
  public:
   V8_INLINE ResultType Visit(HeapObject object);
   V8_INLINE ResultType Visit(Map map, HeapObject object);
+  // A callback for visiting the map pointer in the object header.
+  V8_INLINE void VisitMapPointer(HeapObject host);
 
  protected:
   // A guard predicate for visiting the object.
@@ -86,8 +91,6 @@ class HeapVisitor : public ObjectVisitor {
   V8_INLINE bool ShouldVisit(HeapObject object) { return true; }
   // Guard predicate for visiting the objects map pointer separately.
   V8_INLINE bool ShouldVisitMapPointer() { return true; }
-  // A callback for visiting the map pointer in the object header.
-  V8_INLINE void VisitMapPointer(HeapObject host);
   // If this predicate returns false, then the heap visitor will fail
   // in default Visit implemention for subclasses of JSObject.
   V8_INLINE bool AllowDefaultJSObjectVisit() { return true; }
diff --git a/chromium/v8/src/heap/paged-spaces-inl.h b/chromium/v8/src/heap/paged-spaces-inl.h
index e135e30efc3..8c77186583d 100644
--- a/chromium/v8/src/heap/paged-spaces-inl.h
+++ b/chromium/v8/src/heap/paged-spaces-inl.h
@@ -131,6 +131,7 @@ AllocationResult PagedSpace::AllocateFastAligned(
 
 AllocationResult PagedSpace::AllocateRawUnaligned(int size_in_bytes,
                                                   AllocationOrigin origin) {
+  DCHECK(!FLAG_enable_third_party_heap);
   if (!EnsureLabMain(size_in_bytes, origin)) {
     return AllocationResult::Retry(identity());
   }
@@ -153,6 +154,7 @@ AllocationResult PagedSpace::AllocateRawUnaligned(int size_in_bytes,
 AllocationResult PagedSpace::AllocateRawAligned(int size_in_bytes,
                                                 AllocationAlignment alignment,
                                                 AllocationOrigin origin) {
+  DCHECK(!FLAG_enable_third_party_heap);
   DCHECK_EQ(identity(), OLD_SPACE);
   int allocation_size = size_in_bytes;
   // We don't know exactly how much filler we need to align until space is
@@ -182,6 +184,7 @@ AllocationResult PagedSpace::AllocateRawAligned(int size_in_bytes,
 AllocationResult PagedSpace::AllocateRaw(int size_in_bytes,
                                          AllocationAlignment alignment,
                                          AllocationOrigin origin) {
+  DCHECK(!FLAG_enable_third_party_heap);
   AllocationResult result;
 
   if (alignment != kWordAligned) {
diff --git a/chromium/v8/src/heap/paged-spaces.cc b/chromium/v8/src/heap/paged-spaces.cc
index f541974a506..8543f109ede 100644
--- a/chromium/v8/src/heap/paged-spaces.cc
+++ b/chromium/v8/src/heap/paged-spaces.cc
@@ -731,7 +731,7 @@ void PagedSpace::Verify(Isolate* isolate, ObjectVisitor* visitor) {
   }
   CHECK(allocation_pointer_found_in_space);
 
-  if (identity() == OLD_SPACE) {
+  if (identity() == OLD_SPACE && !FLAG_concurrent_array_buffer_sweeping) {
     size_t bytes = heap()->array_buffer_sweeper()->old().BytesSlow();
     CHECK_EQ(bytes,
              ExternalBackingStoreBytes(ExternalBackingStoreType::kArrayBuffer));
@@ -832,8 +832,8 @@ void PagedSpace::PrepareForMarkCompact() {
 
 bool PagedSpace::RefillLabMain(int size_in_bytes, AllocationOrigin origin) {
   VMState<GC> state(heap()->isolate());
-  RuntimeCallTimerScope runtime_timer(
-      heap()->isolate(), RuntimeCallCounterId::kGC_Custom_SlowAllocateRaw);
+  RCS_SCOPE(heap()->isolate(),
+            RuntimeCallCounterId::kGC_Custom_SlowAllocateRaw);
   return RawRefillLabMain(size_in_bytes, origin);
 }
 
diff --git a/chromium/v8/src/heap/read-only-heap.cc b/chromium/v8/src/heap/read-only-heap.cc
index d5f7e843efe..05ca965e082 100644
--- a/chromium/v8/src/heap/read-only-heap.cc
+++ b/chromium/v8/src/heap/read-only-heap.cc
@@ -249,6 +249,10 @@ bool ReadOnlyHeap::read_only_object_cache_is_initialized() const {
   return read_only_object_cache_.size() > 0;
 }
 
+size_t ReadOnlyHeap::read_only_object_cache_size() const {
+  return read_only_object_cache_.size();
+}
+
 ReadOnlyHeapObjectIterator::ReadOnlyHeapObjectIterator(ReadOnlyHeap* ro_heap)
     : ReadOnlyHeapObjectIterator(ro_heap->read_only_space()) {}
 
diff --git a/chromium/v8/src/heap/read-only-heap.h b/chromium/v8/src/heap/read-only-heap.h
index f947832c5f9..558a694c944 100644
--- a/chromium/v8/src/heap/read-only-heap.h
+++ b/chromium/v8/src/heap/read-only-heap.h
@@ -81,14 +81,15 @@ class ReadOnlyHeap {
   // Returns a read-only cache entry at a particular index.
   Object cached_read_only_object(size_t i) const;
   bool read_only_object_cache_is_initialized() const;
+  size_t read_only_object_cache_size() const;
 
   ReadOnlySpace* read_only_space() const { return read_only_space_; }
 
   // Returns whether the ReadOnlySpace will actually be shared taking into
   // account whether shared memory is available with pointer compression.
   static bool IsReadOnlySpaceShared() {
-    return V8_SHARED_RO_HEAP_BOOL && (!COMPRESS_POINTERS_IN_ISOLATE_CAGE_BOOL ||
-                                      IsSharedMemoryAvailable());
+    return V8_SHARED_RO_HEAP_BOOL &&
+           (!COMPRESS_POINTERS_BOOL || COMPRESS_POINTERS_IN_SHARED_CAGE_BOOL);
   }
 
   virtual void InitializeIsolateRoots(Isolate* isolate) {}
diff --git a/chromium/v8/src/heap/read-only-spaces.cc b/chromium/v8/src/heap/read-only-spaces.cc
index 5adac66afe0..248b5c22e6f 100644
--- a/chromium/v8/src/heap/read-only-spaces.cc
+++ b/chromium/v8/src/heap/read-only-spaces.cc
@@ -56,7 +56,18 @@ void ReadOnlyArtifacts::VerifyChecksum(SnapshotData* read_only_snapshot_data,
     CHECK_WITH_MSG(snapshot_checksum,
                    "Attempt to create the read-only heap after already "
                    "creating from a snapshot.");
-    CHECK_EQ(read_only_blob_checksum_, snapshot_checksum);
+    if (!FLAG_stress_snapshot) {
+      // --stress-snapshot is only intended to check how well the
+      // serializer/deserializer copes with unexpected objects, and is not
+      // intended to test whether the newly deserialized Isolate would actually
+      // work since it serializes a currently running Isolate, which is not
+      // supported. As a result, it's possible that it will create a new
+      // read-only snapshot that is not compatible with the original one (for
+      // instance due to the string table being re-ordered). Since we won't
+      // acutally use that new Isoalte, we're ok with any potential corruption.
+      // See crbug.com/1043058.
+      CHECK_EQ(read_only_blob_checksum_, snapshot_checksum);
+    }
   } else {
     // If there's no checksum, then that means the read-only heap objects are
     // being created.
@@ -70,11 +81,10 @@ SingleCopyReadOnlyArtifacts::~SingleCopyReadOnlyArtifacts() {
   // TearDown requires MemoryAllocator which itself is tied to an Isolate.
   shared_read_only_space_->pages_.resize(0);
 
-  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
   for (ReadOnlyPage* chunk : pages_) {
     void* chunk_address = reinterpret_cast<void*>(chunk->address());
-    size_t size = RoundUp(chunk->size(), page_allocator->AllocatePageSize());
-    CHECK(page_allocator->FreePages(chunk_address, size));
+    size_t size = RoundUp(chunk->size(), page_allocator_->AllocatePageSize());
+    CHECK(page_allocator_->FreePages(chunk_address, size));
   }
 }
 
@@ -86,6 +96,12 @@ ReadOnlyHeap* SingleCopyReadOnlyArtifacts::GetReadOnlyHeapForIsolate(
 void SingleCopyReadOnlyArtifacts::Initialize(Isolate* isolate,
                                              std::vector<ReadOnlyPage*>&& pages,
                                              const AllocationStats& stats) {
+  // Do not use the platform page allocator when sharing a pointer compression
+  // cage, as the Isolate's page allocator is a BoundedPageAllocator tied to the
+  // shared cage.
+  page_allocator_ = COMPRESS_POINTERS_IN_SHARED_CAGE_BOOL
+                        ? isolate->page_allocator()
+                        : GetPlatformPageAllocator();
   pages_ = std::move(pages);
   set_accounting_stats(stats);
   set_shared_read_only_space(
@@ -304,11 +320,12 @@ void ReadOnlySpace::DetachPagesAndAddToArtifacts(
   DCHECK(ReadOnlyHeap::IsReadOnlySpaceShared());
 
   Heap* heap = ReadOnlySpace::heap();
-  // Without pointer compression, ReadOnlySpace pages are directly shared
-  // between all heaps and so must be unregistered from their originating
-  // allocator.
-  Seal(COMPRESS_POINTERS_BOOL ? SealMode::kDetachFromHeap
-                              : SealMode::kDetachFromHeapAndUnregisterMemory);
+  // Without pointer compression in a per-Isolate cage, ReadOnlySpace pages are
+  // directly shared between all heaps and so must be unregistered from their
+  // originating allocator.
+  Seal(COMPRESS_POINTERS_IN_ISOLATE_CAGE_BOOL
+           ? SealMode::kDetachFromHeap
+           : SealMode::kDetachFromHeapAndUnregisterMemory);
   artifacts->Initialize(heap->isolate(), std::move(pages_), accounting_stats_);
 }
 
@@ -635,6 +652,7 @@ HeapObject ReadOnlySpace::TryAllocateLinearlyAligned(
 
 AllocationResult ReadOnlySpace::AllocateRawAligned(
     int size_in_bytes, AllocationAlignment alignment) {
+  DCHECK(!FLAG_enable_third_party_heap);
   DCHECK(!IsDetached());
   int allocation_size = size_in_bytes;
 
@@ -789,9 +807,9 @@ SharedReadOnlySpace::SharedReadOnlySpace(Heap* heap,
                                          SingleCopyReadOnlyArtifacts* artifacts)
     : SharedReadOnlySpace(heap) {
   // This constructor should only be used when RO_SPACE is shared without
-  // pointer compression.
+  // pointer compression in a per-Isolate cage.
   DCHECK(V8_SHARED_RO_HEAP_BOOL);
-  DCHECK(!COMPRESS_POINTERS_BOOL);
+  DCHECK(!COMPRESS_POINTERS_IN_ISOLATE_CAGE_BOOL);
   accounting_stats_ = artifacts->accounting_stats();
   pages_ = artifacts->pages();
 }
diff --git a/chromium/v8/src/heap/read-only-spaces.h b/chromium/v8/src/heap/read-only-spaces.h
index ee4b2a82234..0ca05d8d4c8 100644
--- a/chromium/v8/src/heap/read-only-spaces.h
+++ b/chromium/v8/src/heap/read-only-spaces.h
@@ -132,6 +132,9 @@ class SingleCopyReadOnlyArtifacts : public ReadOnlyArtifacts {
                   const AllocationStats& stats) override;
   void ReinstallReadOnlySpace(Isolate* isolate) override;
   void VerifyHeapAndSpaceRelationships(Isolate* isolate) override;
+
+ private:
+  v8::PageAllocator* page_allocator_ = nullptr;
 };
 
 // -----------------------------------------------------------------------------
diff --git a/chromium/v8/src/heap/scavenger-inl.h b/chromium/v8/src/heap/scavenger-inl.h
index 8560b5b62ba..193565d34de 100644
--- a/chromium/v8/src/heap/scavenger-inl.h
+++ b/chromium/v8/src/heap/scavenger-inl.h
@@ -119,7 +119,7 @@ void Scavenger::PageMemoryFence(MaybeObject object) {
 bool Scavenger::MigrateObject(Map map, HeapObject source, HeapObject target,
                               int size) {
   // Copy the content of source to target.
-  target.set_map_word(MapWord::FromMap(map));
+  target.set_map_word(MapWord::FromMap(map), kRelaxedStore);
   heap()->CopyBlock(target.address() + kTaggedSize,
                     source.address() + kTaggedSize, size - kTaggedSize);
 
@@ -159,7 +159,7 @@ CopyAndForwardResult Scavenger::SemiSpaceCopyObject(
     const bool self_success = MigrateObject(map, object, target, object_size);
     if (!self_success) {
       allocator_.FreeLast(NEW_SPACE, target, object_size);
-      MapWord map_word = object.synchronized_map_word();
+      MapWord map_word = object.map_word(kAcquireLoad);
       HeapObjectReference::Update(slot, map_word.ToForwardingAddress());
       DCHECK(!Heap::InFromPage(*slot));
       return Heap::InToPage(*slot)
@@ -184,6 +184,7 @@ CopyAndForwardResult Scavenger::PromoteObject(Map map, THeapObjectSlot slot,
   static_assert(std::is_same<THeapObjectSlot, FullHeapObjectSlot>::value ||
                     std::is_same<THeapObjectSlot, HeapObjectSlot>::value,
                 "Only FullHeapObjectSlot and HeapObjectSlot are expected here");
+  DCHECK_GE(object_size, Heap::kMinObjectSizeInTaggedWords * kTaggedSize);
   AllocationAlignment alignment = HeapObject::RequiredAlignment(map);
   AllocationResult allocation = allocator_.Allocate(
       OLD_SPACE, object_size, AllocationOrigin::kGC, alignment);
@@ -195,7 +196,7 @@ CopyAndForwardResult Scavenger::PromoteObject(Map map, THeapObjectSlot slot,
     const bool self_success = MigrateObject(map, object, target, object_size);
     if (!self_success) {
       allocator_.FreeLast(OLD_SPACE, target, object_size);
-      MapWord map_word = object.synchronized_map_word();
+      MapWord map_word = object.map_word(kAcquireLoad);
       HeapObjectReference::Update(slot, map_word.ToForwardingAddress());
       DCHECK(!Heap::InFromPage(*slot));
       return Heap::InToPage(*slot)
@@ -326,24 +327,25 @@ SlotCallbackResult Scavenger::EvacuateShortcutCandidate(Map map,
     HeapObjectReference::Update(slot, first);
 
     if (!Heap::InYoungGeneration(first)) {
-      object.synchronized_set_map_word(MapWord::FromForwardingAddress(first));
+      object.set_map_word(MapWord::FromForwardingAddress(first), kReleaseStore);
       return REMOVE_SLOT;
     }
 
-    MapWord first_word = first.synchronized_map_word();
+    MapWord first_word = first.map_word(kAcquireLoad);
     if (first_word.IsForwardingAddress()) {
       HeapObject target = first_word.ToForwardingAddress();
 
       HeapObjectReference::Update(slot, target);
-      object.synchronized_set_map_word(MapWord::FromForwardingAddress(target));
+      object.set_map_word(MapWord::FromForwardingAddress(target),
+                          kReleaseStore);
       return Heap::InYoungGeneration(target) ? KEEP_SLOT : REMOVE_SLOT;
     }
     Map map = first_word.ToMap();
     SlotCallbackResult result =
         EvacuateObjectDefault(map, slot, first, first.SizeFromMap(map),
                               Map::ObjectFieldsFrom(map.visitor_id()));
-    object.synchronized_set_map_word(
-        MapWord::FromForwardingAddress(slot.ToHeapObject()));
+    object.set_map_word(MapWord::FromForwardingAddress(slot.ToHeapObject()),
+                        kReleaseStore);
     return result;
   }
   DCHECK_EQ(ObjectFields::kMaybePointers,
@@ -390,7 +392,7 @@ SlotCallbackResult Scavenger::ScavengeObject(THeapObjectSlot p,
   DCHECK(Heap::InFromPage(object));
 
   // Synchronized load that consumes the publishing CAS of MigrateObject.
-  MapWord first_word = object.synchronized_map_word();
+  MapWord first_word = object.map_word(kAcquireLoad);
 
   // If the first word is a forwarding address, the object has already been
   // copied.
diff --git a/chromium/v8/src/heap/scavenger.cc b/chromium/v8/src/heap/scavenger.cc
index be9971e7c68..efa3ed2f614 100644
--- a/chromium/v8/src/heap/scavenger.cc
+++ b/chromium/v8/src/heap/scavenger.cc
@@ -130,13 +130,13 @@ namespace {
 
 V8_INLINE bool IsUnscavengedHeapObject(Heap* heap, Object object) {
   return Heap::InFromPage(object) &&
-         !HeapObject::cast(object).map_word().IsForwardingAddress();
+         !HeapObject::cast(object).map_word(kRelaxedLoad).IsForwardingAddress();
 }
 
 // Same as IsUnscavengedHeapObject() above but specialized for HeapObjects.
 V8_INLINE bool IsUnscavengedHeapObject(Heap* heap, HeapObject heap_object) {
   return Heap::InFromPage(heap_object) &&
-         !heap_object.map_word().IsForwardingAddress();
+         !heap_object.map_word(kRelaxedLoad).IsForwardingAddress();
 }
 
 bool IsUnscavengedHeapObjectSlot(Heap* heap, FullObjectSlot p) {
@@ -152,7 +152,7 @@ class ScavengeWeakObjectRetainer : public WeakObjectRetainer {
       return object;
     }
 
-    MapWord map_word = HeapObject::cast(object).map_word();
+    MapWord map_word = HeapObject::cast(object).map_word(kRelaxedLoad);
     if (map_word.IsForwardingAddress()) {
       return map_word.ToForwardingAddress();
     }
@@ -384,6 +384,10 @@ void ScavengerCollector::CollectGarbage() {
         &Heap::UpdateYoungReferenceInExternalStringTableEntry);
 
     heap_->incremental_marking()->UpdateMarkingWorklistAfterScavenge();
+
+    if (V8_UNLIKELY(FLAG_track_retaining_path)) {
+      heap_->UpdateRetainersAfterScavenge();
+    }
   }
 
   if (FLAG_concurrent_marking) {
@@ -481,7 +485,7 @@ void ScavengerCollector::HandleSurvivingNewLargeObjects() {
     Map map = update_info.second;
     // Order is important here. We have to re-install the map to have access
     // to meta-data like size during page promotion.
-    object.set_map_word(MapWord::FromMap(map));
+    object.set_map_word(MapWord::FromMap(map), kRelaxedStore);
     LargePage* page = LargePage::FromHeapObject(object);
     heap_->lo_space()->PromoteNewLargeObject(page);
   }
@@ -734,6 +738,7 @@ void Scavenger::AddEphemeronHashTable(EphemeronHashTable table) {
 void RootScavengeVisitor::VisitRootPointer(Root root, const char* description,
                                            FullObjectSlot p) {
   DCHECK(!HasWeakHeapObjectTag(*p));
+  DCHECK(!MapWord::IsPacked((*p).ptr()));
   ScavengePointer(p);
 }
 
@@ -741,12 +746,15 @@ void RootScavengeVisitor::VisitRootPointers(Root root, const char* description,
                                             FullObjectSlot start,
                                             FullObjectSlot end) {
   // Copy all HeapObject pointers in [start, end)
-  for (FullObjectSlot p = start; p < end; ++p) ScavengePointer(p);
+  for (FullObjectSlot p = start; p < end; ++p) {
+    ScavengePointer(p);
+  }
 }
 
 void RootScavengeVisitor::ScavengePointer(FullObjectSlot p) {
   Object object = *p;
   DCHECK(!HasWeakHeapObjectTag(object));
+  DCHECK(!MapWord::IsPacked(object.ptr()));
   if (Heap::InYoungGeneration(object)) {
     scavenger_->ScavengeObject(FullHeapObjectSlot(p), HeapObject::cast(object));
   }
diff --git a/chromium/v8/src/heap/setup-heap-internal.cc b/chromium/v8/src/heap/setup-heap-internal.cc
index 8a3e1fda121..886c89aeae0 100644
--- a/chromium/v8/src/heap/setup-heap-internal.cc
+++ b/chromium/v8/src/heap/setup-heap-internal.cc
@@ -195,9 +195,10 @@ void Heap::FinalizePartialMap(Map map) {
   map.set_constructor_or_back_pointer(roots.null_value());
 }
 
-AllocationResult Heap::Allocate(Map map, AllocationType allocation_type) {
-  DCHECK(map.instance_type() != MAP_TYPE);
-  int size = map.instance_size();
+AllocationResult Heap::Allocate(Handle<Map> map,
+                                AllocationType allocation_type) {
+  DCHECK(map->instance_type() != MAP_TYPE);
+  int size = map->instance_size();
   HeapObject result;
   AllocationResult allocation = AllocateRaw(size, allocation_type);
   if (!allocation.To(&result)) return allocation;
@@ -205,7 +206,7 @@ AllocationResult Heap::Allocate(Map map, AllocationType allocation_type) {
   WriteBarrierMode write_barrier_mode =
       allocation_type == AllocationType::kYoung ? SKIP_WRITE_BARRIER
                                                 : UPDATE_WRITE_BARRIER;
-  result.set_map_after_allocation(map, write_barrier_mode);
+  result.set_map_after_allocation(*map, write_barrier_mode);
   return result;
 }
 
@@ -281,7 +282,7 @@ bool Heap::CreateInitialMaps() {
 
   {
     AllocationResult allocation =
-        Allocate(roots.null_map(), AllocationType::kReadOnly);
+        Allocate(roots.null_map_handle(), AllocationType::kReadOnly);
     if (!allocation.To(&obj)) return false;
   }
   set_null_value(Oddball::cast(obj));
@@ -289,7 +290,7 @@ bool Heap::CreateInitialMaps() {
 
   {
     AllocationResult allocation =
-        Allocate(roots.undefined_map(), AllocationType::kReadOnly);
+        Allocate(roots.undefined_map_handle(), AllocationType::kReadOnly);
     if (!allocation.To(&obj)) return false;
   }
   set_undefined_value(Oddball::cast(obj));
@@ -297,7 +298,7 @@ bool Heap::CreateInitialMaps() {
   DCHECK(!InYoungGeneration(roots.undefined_value()));
   {
     AllocationResult allocation =
-        Allocate(roots.the_hole_map(), AllocationType::kReadOnly);
+        Allocate(roots.the_hole_map_handle(), AllocationType::kReadOnly);
     if (!allocation.To(&obj)) return false;
   }
   set_the_hole_value(Oddball::cast(obj));
@@ -317,7 +318,7 @@ bool Heap::CreateInitialMaps() {
   // Allocate the empty enum cache.
   {
     AllocationResult allocation =
-        Allocate(roots.enum_cache_map(), AllocationType::kReadOnly);
+        Allocate(roots.enum_cache_map_handle(), AllocationType::kReadOnly);
     if (!allocation.To(&obj)) return false;
   }
   set_empty_enum_cache(EnumCache::cast(obj));
@@ -381,6 +382,7 @@ bool Heap::CreateInitialMaps() {
     ALLOCATE_PRIMITIVE_MAP(SYMBOL_TYPE, Symbol::kSize, symbol,
                            Context::SYMBOL_FUNCTION_INDEX)
     ALLOCATE_MAP(FOREIGN_TYPE, Foreign::kSize, foreign)
+    ALLOCATE_MAP(MEGA_DOM_HANDLER_TYPE, MegaDomHandler::kSize, mega_dom_handler)
 
     ALLOCATE_PRIMITIVE_MAP(ODDBALL_TYPE, Oddball::kSize, boolean,
                            Context::BOOLEAN_FUNCTION_INDEX);
@@ -500,6 +502,10 @@ bool Heap::CreateInitialMaps() {
     ALLOCATE_MAP(CODE_DATA_CONTAINER_TYPE, CodeDataContainer::kSize,
                  code_data_container)
 
+    IF_WASM(ALLOCATE_MAP, WASM_EXPORTED_FUNCTION_DATA_TYPE,
+            WasmExportedFunctionData::kSize, wasm_exported_function_data)
+    IF_WASM(ALLOCATE_MAP, WASM_JS_FUNCTION_DATA_TYPE, WasmJSFunctionData::kSize,
+            wasm_js_function_data)
     IF_WASM(ALLOCATE_MAP, WASM_TYPE_INFO_TYPE, WasmTypeInfo::kSize,
             wasm_type_info)
 
@@ -550,8 +556,9 @@ bool Heap::CreateInitialMaps() {
 
   {
     // Empty array boilerplate description
-    AllocationResult alloc = Allocate(roots.array_boilerplate_description_map(),
-                                      AllocationType::kReadOnly);
+    AllocationResult alloc =
+        Allocate(roots.array_boilerplate_description_map_handle(),
+                 AllocationType::kReadOnly);
     if (!alloc.To(&obj)) return false;
 
     ArrayBoilerplateDescription::cast(obj).set_constant_elements(
@@ -564,7 +571,7 @@ bool Heap::CreateInitialMaps() {
 
   {
     AllocationResult allocation =
-        Allocate(roots.boolean_map(), AllocationType::kReadOnly);
+        Allocate(roots.boolean_map_handle(), AllocationType::kReadOnly);
     if (!allocation.To(&obj)) return false;
   }
   set_true_value(Oddball::cast(obj));
@@ -572,7 +579,7 @@ bool Heap::CreateInitialMaps() {
 
   {
     AllocationResult allocation =
-        Allocate(roots.boolean_map(), AllocationType::kReadOnly);
+        Allocate(roots.boolean_map_handle(), AllocationType::kReadOnly);
     if (!allocation.To(&obj)) return false;
   }
   set_false_value(Oddball::cast(obj));
@@ -864,6 +871,7 @@ void Heap::CreateInitialObjects() {
   set_is_concat_spreadable_protector(*factory->NewProtector());
   set_map_iterator_protector(*factory->NewProtector());
   set_no_elements_protector(*factory->NewProtector());
+  set_mega_dom_protector(*factory->NewProtector());
   set_promise_hook_protector(*factory->NewProtector());
   set_promise_resolve_protector(*factory->NewProtector());
   set_promise_species_protector(*factory->NewProtector());
diff --git a/chromium/v8/src/heap/spaces-inl.h b/chromium/v8/src/heap/spaces-inl.h
index ccdf050e681..9b9a02af437 100644
--- a/chromium/v8/src/heap/spaces-inl.h
+++ b/chromium/v8/src/heap/spaces-inl.h
@@ -141,7 +141,8 @@ AllocationResult LocalAllocationBuffer::AllocateRawAligned(
   int filler_size = Heap::GetFillToAlign(current_top, alignment);
 
   Address new_top = current_top + filler_size + size_in_bytes;
-  if (new_top > allocation_info_.limit()) return AllocationResult::Retry();
+  if (new_top > allocation_info_.limit())
+    return AllocationResult::Retry(NEW_SPACE);
 
   allocation_info_.set_top(new_top);
   if (filler_size > 0) {
diff --git a/chromium/v8/src/heap/spaces.cc b/chromium/v8/src/heap/spaces.cc
index b6c1e0bcc2a..63346786d51 100644
--- a/chromium/v8/src/heap/spaces.cc
+++ b/chromium/v8/src/heap/spaces.cc
@@ -11,6 +11,7 @@
 #include "src/base/bits.h"
 #include "src/base/bounded-page-allocator.h"
 #include "src/base/macros.h"
+#include "src/base/sanitizer/msan.h"
 #include "src/common/globals.h"
 #include "src/heap/combined-heap.h"
 #include "src/heap/concurrent-marking.h"
@@ -31,7 +32,6 @@
 #include "src/objects/heap-object.h"
 #include "src/objects/js-array-buffer-inl.h"
 #include "src/objects/objects-inl.h"
-#include "src/sanitizer/msan.h"
 #include "src/snapshot/snapshot.h"
 #include "src/utils/ostreams.h"
 
diff --git a/chromium/v8/src/heap/spaces.h b/chromium/v8/src/heap/spaces.h
index 0a0a884dc02..4afada00ceb 100644
--- a/chromium/v8/src/heap/spaces.h
+++ b/chromium/v8/src/heap/spaces.h
@@ -221,9 +221,11 @@ class Page : public MemoryChunk {
   // from [page_addr .. page_addr + kPageSize[. This only works if the object
   // is in fact in a page.
   static Page* FromAddress(Address addr) {
+    DCHECK(!V8_ENABLE_THIRD_PARTY_HEAP_BOOL);
     return reinterpret_cast<Page*>(addr & ~kPageAlignmentMask);
   }
   static Page* FromHeapObject(HeapObject o) {
+    DCHECK(!V8_ENABLE_THIRD_PARTY_HEAP_BOOL);
     return reinterpret_cast<Page*>(o.ptr() & ~kAlignmentMask);
   }
 
@@ -232,6 +234,7 @@ class Page : public MemoryChunk {
   // we subtract a hole word. The valid address ranges from
   // [page_addr + area_start_ .. page_addr + kPageSize + kTaggedSize].
   static Page* FromAllocationAreaAddress(Address address) {
+    DCHECK(!V8_ENABLE_THIRD_PARTY_HEAP_BOOL);
     return Page::FromAddress(address - kTaggedSize);
   }
 
diff --git a/chromium/v8/src/heap/sweeper.cc b/chromium/v8/src/heap/sweeper.cc
index c4e60be7072..0e35a3cea2b 100644
--- a/chromium/v8/src/heap/sweeper.cc
+++ b/chromium/v8/src/heap/sweeper.cc
@@ -351,9 +351,6 @@ int Sweeper::RawSweep(
   size_t live_bytes = 0;
   size_t max_freed_bytes = 0;
 
-  // TODO(ulan): we don't have to clear type old-to-old slots in code space
-  // because the concurrent marker doesn't mark code objects. This requires
-  // the write barrier for code objects to check the color of the code object.
   bool non_empty_typed_slots = p->typed_slot_set<OLD_TO_NEW>() != nullptr ||
                                p->typed_slot_set<OLD_TO_OLD>() != nullptr;
 
@@ -393,7 +390,8 @@ int Sweeper::RawSweep(
           free_start, free_end, p, non_empty_typed_slots, &free_ranges_map,
           &old_to_new_cleanup);
     }
-    Map map = object.synchronized_map();
+    Map map = object.map(kAcquireLoad);
+    DCHECK(map.IsMap());
     int size = object.SizeFromMap(map);
     live_bytes += size;
     free_start = free_end + size;
diff --git a/chromium/v8/src/heap/third-party/heap-api-stub.cc b/chromium/v8/src/heap/third-party/heap-api-stub.cc
index 6d31479bec6..f7ccb50810a 100644
--- a/chromium/v8/src/heap/third-party/heap-api-stub.cc
+++ b/chromium/v8/src/heap/third-party/heap-api-stub.cc
@@ -38,6 +38,12 @@ const base::AddressRegion& Heap::GetCodeRange() {
 }
 
 // static
+bool Heap::InSpace(Address, AllocationSpace) { return false; }
+
+// static
+bool Heap::InOldSpace(Address) { return false; }
+
+// static
 bool Heap::InCodeSpace(Address) { return false; }
 
 // static
diff --git a/chromium/v8/src/heap/third-party/heap-api.h b/chromium/v8/src/heap/third-party/heap-api.h
index c4712b988e9..16f2fde8842 100644
--- a/chromium/v8/src/heap/third-party/heap-api.h
+++ b/chromium/v8/src/heap/third-party/heap-api.h
@@ -26,6 +26,10 @@ class Heap {
 
   const base::AddressRegion& GetCodeRange();
 
+  static bool InSpace(Address address, AllocationSpace space);
+
+  static bool InOldSpace(Address address);
+
   static bool InCodeSpace(Address address);
 
   static bool InReadOnlySpace(Address address);
@@ -38,6 +42,8 @@ class Heap {
   HeapObject NextObject();
 
   bool CollectGarbage();
+
+  size_t Capacity();
 };
 
 }  // namespace third_party_heap
diff --git a/chromium/v8/src/heap/weak-object-worklists.cc b/chromium/v8/src/heap/weak-object-worklists.cc
index 532739000fe..84df473076f 100644
--- a/chromium/v8/src/heap/weak-object-worklists.cc
+++ b/chromium/v8/src/heap/weak-object-worklists.cc
@@ -115,19 +115,17 @@ void WeakObjects::UpdateWeakObjectsInCode(
 
 void WeakObjects::UpdateJSWeakRefs(
     WeakObjectWorklist<JSWeakRef>& js_weak_refs) {
-  if (FLAG_harmony_weak_refs) {
-    js_weak_refs.Update(
-        [](JSWeakRef js_weak_ref_in, JSWeakRef* js_weak_ref_out) -> bool {
-          JSWeakRef forwarded = ForwardingAddress(js_weak_ref_in);
-
-          if (!forwarded.is_null()) {
-            *js_weak_ref_out = forwarded;
-            return true;
-          }
-
-          return false;
-        });
-  }
+  js_weak_refs.Update(
+      [](JSWeakRef js_weak_ref_in, JSWeakRef* js_weak_ref_out) -> bool {
+        JSWeakRef forwarded = ForwardingAddress(js_weak_ref_in);
+
+        if (!forwarded.is_null()) {
+          *js_weak_ref_out = forwarded;
+          return true;
+        }
+
+        return false;
+      });
 }
 
 void WeakObjects::UpdateWeakCells(WeakObjectWorklist<WeakCell>& weak_cells) {
diff --git a/chromium/v8/src/ic/accessor-assembler.cc b/chromium/v8/src/ic/accessor-assembler.cc
index 35d1da5cd92..0ff67d030af 100644
--- a/chromium/v8/src/ic/accessor-assembler.cc
+++ b/chromium/v8/src/ic/accessor-assembler.cc
@@ -8,6 +8,7 @@
 #include "src/base/optional.h"
 #include "src/builtins/builtins-constructor-gen.h"
 #include "src/codegen/code-factory.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/ic/handler-configuration.h"
 #include "src/ic/ic.h"
 #include "src/ic/keyed-store-generic.h"
@@ -16,6 +17,7 @@
 #include "src/objects/cell.h"
 #include "src/objects/foreign.h"
 #include "src/objects/heap-number.h"
+#include "src/objects/megadom-handler.h"
 #include "src/objects/module.h"
 #include "src/objects/objects-inl.h"
 #include "src/objects/property-details.h"
@@ -134,6 +136,55 @@ void AccessorAssembler::HandlePolymorphicCase(
   }
 }
 
+void AccessorAssembler::TryMegaDOMCase(TNode<Object> lookup_start_object,
+                                       TNode<Map> lookup_start_object_map,
+                                       TVariable<MaybeObject>* var_handler,
+                                       TNode<Object> vector,
+                                       TNode<TaggedIndex> slot, Label* miss,
+                                       ExitPoint* exit_point) {
+  // Check if the receiver is a JS_API_OBJECT
+  GotoIfNot(IsJSApiObjectMap(lookup_start_object_map), miss);
+
+  // Check if receiver requires access check
+  GotoIf(IsSetWord32<Map::Bits1::IsAccessCheckNeededBit>(
+             LoadMapBitField(lookup_start_object_map)),
+         miss);
+
+  CSA_ASSERT(this, TaggedEqual(LoadFeedbackVectorSlot(CAST(vector), slot),
+                               MegaDOMSymbolConstant()));
+
+  // In some cases, we load the
+  TNode<MegaDomHandler> handler;
+  if (var_handler->IsBound()) {
+    handler = CAST(var_handler->value());
+  } else {
+    TNode<MaybeObject> maybe_handler =
+        LoadFeedbackVectorSlot(CAST(vector), slot, kTaggedSize);
+    CSA_ASSERT(this, IsStrong(maybe_handler));
+    handler = CAST(maybe_handler);
+  }
+
+  // Check if dom protector cell is still valid
+  GotoIf(IsMegaDOMProtectorCellInvalid(), miss);
+
+  // Load the getter
+  TNode<MaybeObject> maybe_getter = LoadMegaDomHandlerAccessor(handler);
+  CSA_ASSERT(this, IsWeakOrCleared(maybe_getter));
+  TNode<FunctionTemplateInfo> getter =
+      CAST(GetHeapObjectAssumeWeak(maybe_getter, miss));
+
+  // Load the accessor context
+  TNode<MaybeObject> maybe_context = LoadMegaDomHandlerContext(handler);
+  CSA_ASSERT(this, IsWeakOrCleared(maybe_context));
+  TNode<Context> context = CAST(GetHeapObjectAssumeWeak(maybe_context, miss));
+
+  // TODO(gsathya): This builtin throws an exception on interface check fail but
+  // we should miss to the runtime.
+  exit_point->Return(
+      CallBuiltin(Builtins::kCallFunctionTemplate_CheckCompatibleReceiver,
+                  context, getter, IntPtrConstant(0), lookup_start_object));
+}
+
 void AccessorAssembler::HandleLoadICHandlerCase(
     const LazyLoadICParameters* p, TNode<Object> handler, Label* miss,
     ExitPoint* exit_point, ICMode ic_mode, OnNonExistent on_nonexistent,
@@ -543,7 +594,7 @@ void AccessorAssembler::HandleLoadICSmiHandlerLoadNamedCase(
           properties, var_name_index.value(), &var_details, &var_value);
       TNode<Object> value = CallGetterIfAccessor(
           var_value.value(), CAST(holder), var_details.value(), p->context(),
-          p->receiver(), miss);
+          p->receiver(), p->name(), miss);
       exit_point->Return(value);
     }
   }
@@ -563,11 +614,17 @@ void AccessorAssembler::HandleLoadICSmiHandlerLoadNamedCase(
   }
 
   BIND(&native_data_property);
-  HandleLoadCallbackProperty(p, CAST(holder), handler_word, exit_point);
+  {
+    GotoIf(IsSideEffectFreeDebuggingActive(), &slow);
+    HandleLoadCallbackProperty(p, CAST(holder), handler_word, exit_point);
+  }
 
   BIND(&api_getter);
-  HandleLoadAccessor(p, CAST(holder), handler_word, CAST(handler), handler_kind,
-                     exit_point);
+  {
+    GotoIf(IsSideEffectFreeDebuggingActive(), &slow);
+    HandleLoadAccessor(p, CAST(holder), handler_word, CAST(handler),
+                       handler_kind, exit_point);
+  }
 
   BIND(&proxy);
   {
@@ -627,7 +684,8 @@ void AccessorAssembler::HandleLoadICSmiHandlerLoadNamedCase(
     GotoIf(IsTheHole(value), miss);
 
     exit_point->Return(CallGetterIfAccessor(value, CAST(holder), details,
-                                            p->context(), p->receiver(), miss));
+                                            p->context(), p->receiver(),
+                                            p->name(), miss));
   }
 
   BIND(&interceptor);
@@ -645,8 +703,9 @@ void AccessorAssembler::HandleLoadICSmiHandlerLoadNamedCase(
                                     p->name(), p->slot(), p->vector());
 
     } else {
-      exit_point->ReturnCallRuntime(Runtime::kGetProperty, p->context(), holder,
-                                    p->name(), p->receiver());
+      exit_point->ReturnCallRuntime(Runtime::kGetProperty, p->context(),
+                                    p->lookup_start_object(), p->name(),
+                                    p->receiver());
     }
   }
 
@@ -912,7 +971,7 @@ void AccessorAssembler::HandleLoadICProtoHandler(
               properties, name_index, &var_details, &var_value);
           TNode<Object> value = CallGetterIfAccessor(
               var_value.value(), CAST(var_holder->value()), var_details.value(),
-              p->context(), p->receiver(), miss);
+              p->context(), p->receiver(), p->name(), miss);
           exit_point->Return(value);
         }
       },
@@ -1507,7 +1566,6 @@ void AccessorAssembler::HandleStoreAccessor(const StoreICParameters* p,
       LoadObjectField(accessor_pair, AccessorPair::kSetterOffset);
   CSA_ASSERT(this, Word32BinaryNot(IsTheHole(setter)));
 
-  Callable callable = CodeFactory::Call(isolate());
   Return(Call(p->context(), setter, p->receiver(), p->value()));
 }
 
@@ -1686,9 +1744,12 @@ void AccessorAssembler::HandleStoreICProtoHandler(
       Goto(&store);
 
       BIND(&store);
-      TNode<IntPtrT> argc = IntPtrConstant(1);
-      Return(CallApiCallback(context, callback, argc, data, api_holder.value(),
-                             p->receiver(), p->value()));
+      {
+        GotoIf(IsSideEffectFreeDebuggingActive(), &if_slow);
+        TNode<IntPtrT> argc = IntPtrConstant(1);
+        Return(CallApiCallback(context, callback, argc, data,
+                               api_holder.value(), p->receiver(), p->value()));
+      }
     }
 
     BIND(&if_store_global_proxy);
@@ -2036,9 +2097,9 @@ void AccessorAssembler::EmitElementLoad(
     Label* if_hole, Label* rebox_double, TVariable<Float64T>* var_double_value,
     Label* unimplemented_elements_kind, Label* out_of_bounds, Label* miss,
     ExitPoint* exit_point, LoadAccessMode access_mode) {
-  Label if_typed_array(this), if_fast(this), if_fast_packed(this),
-      if_fast_holey(this), if_fast_double(this), if_fast_holey_double(this),
-      if_nonfast(this), if_dictionary(this);
+  Label if_rab_gsab_typed_array(this), if_typed_array(this), if_fast(this),
+      if_fast_packed(this), if_fast_holey(this), if_fast_double(this),
+      if_fast_holey_double(this), if_nonfast(this), if_dictionary(this);
   Branch(Int32GreaterThan(elements_kind,
                           Int32Constant(LAST_ANY_NONEXTENSIBLE_ELEMENTS_KIND)),
          &if_nonfast, &if_fast);
@@ -2119,7 +2180,16 @@ void AccessorAssembler::EmitElementLoad(
 
   BIND(&if_nonfast);
   {
-    STATIC_ASSERT(LAST_ELEMENTS_KIND == LAST_FIXED_TYPED_ARRAY_ELEMENTS_KIND);
+    Label uint8_elements(this), int8_elements(this), uint16_elements(this),
+        int16_elements(this), uint32_elements(this), int32_elements(this),
+        float32_elements(this), float64_elements(this), bigint64_elements(this),
+        biguint64_elements(this);
+    STATIC_ASSERT(LAST_ELEMENTS_KIND ==
+                  LAST_RAB_GSAB_FIXED_TYPED_ARRAY_ELEMENTS_KIND);
+    GotoIf(Int32GreaterThanOrEqual(
+               elements_kind,
+               Int32Constant(FIRST_RAB_GSAB_FIXED_TYPED_ARRAY_ELEMENTS_KIND)),
+           &if_rab_gsab_typed_array);
     GotoIf(Int32GreaterThanOrEqual(
                elements_kind,
                Int32Constant(FIRST_FIXED_TYPED_ARRAY_ELEMENTS_KIND)),
@@ -2145,88 +2215,129 @@ void AccessorAssembler::EmitElementLoad(
       exit_point->Return(access_mode == LoadAccessMode::kHas ? TrueConstant()
                                                              : value);
     }
-
-    BIND(&if_typed_array);
     {
-      Comment("typed elements");
-      // Check if buffer has been detached.
-      TNode<JSArrayBuffer> buffer = LoadJSArrayBufferViewBuffer(CAST(object));
-      GotoIf(IsDetachedBuffer(buffer), miss);
-
-      // Bounds check.
-      TNode<UintPtrT> length = LoadJSTypedArrayLength(CAST(object));
-      GotoIfNot(UintPtrLessThan(intptr_index, length), out_of_bounds);
-      if (access_mode == LoadAccessMode::kHas) {
-        exit_point->Return(TrueConstant());
-      } else {
-        TNode<RawPtrT> data_ptr = LoadJSTypedArrayDataPtr(CAST(object));
-
-        Label uint8_elements(this), int8_elements(this), uint16_elements(this),
-            int16_elements(this), uint32_elements(this), int32_elements(this),
-            float32_elements(this), float64_elements(this),
-            bigint64_elements(this), biguint64_elements(this);
-        Label* elements_kind_labels[] = {
-            &uint8_elements,    &uint8_elements,    &int8_elements,
-            &uint16_elements,   &int16_elements,    &uint32_elements,
-            &int32_elements,    &float32_elements,  &float64_elements,
-            &bigint64_elements, &biguint64_elements};
-        int32_t elements_kinds[] = {
-            UINT8_ELEMENTS,    UINT8_CLAMPED_ELEMENTS, INT8_ELEMENTS,
-            UINT16_ELEMENTS,   INT16_ELEMENTS,         UINT32_ELEMENTS,
-            INT32_ELEMENTS,    FLOAT32_ELEMENTS,       FLOAT64_ELEMENTS,
-            BIGINT64_ELEMENTS, BIGUINT64_ELEMENTS};
-        const size_t kTypedElementsKindCount =
-            LAST_FIXED_TYPED_ARRAY_ELEMENTS_KIND -
-            FIRST_FIXED_TYPED_ARRAY_ELEMENTS_KIND + 1;
-        DCHECK_EQ(kTypedElementsKindCount, arraysize(elements_kinds));
-        DCHECK_EQ(kTypedElementsKindCount, arraysize(elements_kind_labels));
-        Switch(elements_kind, miss, elements_kinds, elements_kind_labels,
-               kTypedElementsKindCount);
+      TVARIABLE(RawPtrT, data_ptr);
+      BIND(&if_rab_gsab_typed_array);
+      {
+        Comment("rab gsab typed elements");
+        Label variable_length(this), normal(this), length_check_ok(this);
+
+        TNode<JSTypedArray> array = CAST(object);
+        TNode<JSArrayBuffer> buffer = LoadJSArrayBufferViewBuffer(array);
+
+        // Bounds check (incl. detachedness check).
+        TNode<UintPtrT> length =
+            LoadVariableLengthJSTypedArrayLength(array, buffer, miss);
+        Branch(UintPtrLessThan(intptr_index, length), &length_check_ok,
+               out_of_bounds);
+        BIND(&length_check_ok);
+        {
+          if (access_mode == LoadAccessMode::kHas) {
+            exit_point->Return(TrueConstant());
+          } else {
+            data_ptr = LoadJSTypedArrayDataPtr(array);
+            Label* elements_kind_labels[] = {
+                &uint8_elements,    &uint8_elements,    &int8_elements,
+                &uint16_elements,   &int16_elements,    &uint32_elements,
+                &int32_elements,    &float32_elements,  &float64_elements,
+                &bigint64_elements, &biguint64_elements};
+            int32_t elements_kinds[] = {
+                RAB_GSAB_UINT8_ELEMENTS,    RAB_GSAB_UINT8_CLAMPED_ELEMENTS,
+                RAB_GSAB_INT8_ELEMENTS,     RAB_GSAB_UINT16_ELEMENTS,
+                RAB_GSAB_INT16_ELEMENTS,    RAB_GSAB_UINT32_ELEMENTS,
+                RAB_GSAB_INT32_ELEMENTS,    RAB_GSAB_FLOAT32_ELEMENTS,
+                RAB_GSAB_FLOAT64_ELEMENTS,  RAB_GSAB_BIGINT64_ELEMENTS,
+                RAB_GSAB_BIGUINT64_ELEMENTS};
+            const size_t kTypedElementsKindCount =
+                LAST_RAB_GSAB_FIXED_TYPED_ARRAY_ELEMENTS_KIND -
+                FIRST_RAB_GSAB_FIXED_TYPED_ARRAY_ELEMENTS_KIND + 1;
+            DCHECK_EQ(kTypedElementsKindCount, arraysize(elements_kinds));
+            DCHECK_EQ(kTypedElementsKindCount, arraysize(elements_kind_labels));
+            Switch(elements_kind, miss, elements_kinds, elements_kind_labels,
+                   kTypedElementsKindCount);
+          }
+        }
+      }
+      BIND(&if_typed_array);
+      {
+        Comment("typed elements");
+        // Check if buffer has been detached.
+        TNode<JSArrayBuffer> buffer = LoadJSArrayBufferViewBuffer(CAST(object));
+        GotoIf(IsDetachedBuffer(buffer), miss);
+
+        // Bounds check.
+        TNode<UintPtrT> length = LoadJSTypedArrayLength(CAST(object));
+        GotoIfNot(UintPtrLessThan(intptr_index, length), out_of_bounds);
+        if (access_mode == LoadAccessMode::kHas) {
+          exit_point->Return(TrueConstant());
+        } else {
+          data_ptr = LoadJSTypedArrayDataPtr(CAST(object));
+
+          Label* elements_kind_labels[] = {
+              &uint8_elements,    &uint8_elements,    &int8_elements,
+              &uint16_elements,   &int16_elements,    &uint32_elements,
+              &int32_elements,    &float32_elements,  &float64_elements,
+              &bigint64_elements, &biguint64_elements};
+          int32_t elements_kinds[] = {
+              UINT8_ELEMENTS,    UINT8_CLAMPED_ELEMENTS, INT8_ELEMENTS,
+              UINT16_ELEMENTS,   INT16_ELEMENTS,         UINT32_ELEMENTS,
+              INT32_ELEMENTS,    FLOAT32_ELEMENTS,       FLOAT64_ELEMENTS,
+              BIGINT64_ELEMENTS, BIGUINT64_ELEMENTS};
+          const size_t kTypedElementsKindCount =
+              LAST_FIXED_TYPED_ARRAY_ELEMENTS_KIND -
+              FIRST_FIXED_TYPED_ARRAY_ELEMENTS_KIND + 1;
+          DCHECK_EQ(kTypedElementsKindCount, arraysize(elements_kinds));
+          DCHECK_EQ(kTypedElementsKindCount, arraysize(elements_kind_labels));
+          Switch(elements_kind, miss, elements_kinds, elements_kind_labels,
+                 kTypedElementsKindCount);
+        }
+      }
+      if (access_mode != LoadAccessMode::kHas) {
         BIND(&uint8_elements);
         {
           Comment("UINT8_ELEMENTS");  // Handles UINT8_CLAMPED_ELEMENTS too.
-          TNode<Int32T> element = Load<Uint8T>(data_ptr, intptr_index);
+          TNode<Int32T> element = Load<Uint8T>(data_ptr.value(), intptr_index);
           exit_point->Return(SmiFromInt32(element));
         }
         BIND(&int8_elements);
         {
           Comment("INT8_ELEMENTS");
-          TNode<Int32T> element = Load<Int8T>(data_ptr, intptr_index);
+          TNode<Int32T> element = Load<Int8T>(data_ptr.value(), intptr_index);
           exit_point->Return(SmiFromInt32(element));
         }
         BIND(&uint16_elements);
         {
           Comment("UINT16_ELEMENTS");
           TNode<IntPtrT> index = WordShl(intptr_index, IntPtrConstant(1));
-          TNode<Int32T> element = Load<Uint16T>(data_ptr, index);
+          TNode<Int32T> element = Load<Uint16T>(data_ptr.value(), index);
           exit_point->Return(SmiFromInt32(element));
         }
         BIND(&int16_elements);
         {
           Comment("INT16_ELEMENTS");
           TNode<IntPtrT> index = WordShl(intptr_index, IntPtrConstant(1));
-          TNode<Int32T> element = Load<Int16T>(data_ptr, index);
+          TNode<Int32T> element = Load<Int16T>(data_ptr.value(), index);
           exit_point->Return(SmiFromInt32(element));
         }
         BIND(&uint32_elements);
         {
           Comment("UINT32_ELEMENTS");
           TNode<IntPtrT> index = WordShl(intptr_index, IntPtrConstant(2));
-          TNode<Uint32T> element = Load<Uint32T>(data_ptr, index);
+          TNode<Uint32T> element = Load<Uint32T>(data_ptr.value(), index);
           exit_point->Return(ChangeUint32ToTagged(element));
         }
         BIND(&int32_elements);
         {
           Comment("INT32_ELEMENTS");
           TNode<IntPtrT> index = WordShl(intptr_index, IntPtrConstant(2));
-          TNode<Int32T> element = Load<Int32T>(data_ptr, index);
+          TNode<Int32T> element = Load<Int32T>(data_ptr.value(), index);
           exit_point->Return(ChangeInt32ToTagged(element));
         }
         BIND(&float32_elements);
         {
           Comment("FLOAT32_ELEMENTS");
           TNode<IntPtrT> index = WordShl(intptr_index, IntPtrConstant(2));
-          TNode<Float32T> element = Load<Float32T>(data_ptr, index);
+          TNode<Float32T> element = Load<Float32T>(data_ptr.value(), index);
           *var_double_value = ChangeFloat32ToFloat64(element);
           Goto(rebox_double);
         }
@@ -2234,7 +2345,7 @@ void AccessorAssembler::EmitElementLoad(
         {
           Comment("FLOAT64_ELEMENTS");
           TNode<IntPtrT> index = WordShl(intptr_index, IntPtrConstant(3));
-          TNode<Float64T> element = Load<Float64T>(data_ptr, index);
+          TNode<Float64T> element = Load<Float64T>(data_ptr.value(), index);
           *var_double_value = element;
           Goto(rebox_double);
         }
@@ -2242,13 +2353,13 @@ void AccessorAssembler::EmitElementLoad(
         {
           Comment("BIGINT64_ELEMENTS");
           exit_point->Return(LoadFixedTypedArrayElementAsTagged(
-              data_ptr, Unsigned(intptr_index), BIGINT64_ELEMENTS));
+              data_ptr.value(), Unsigned(intptr_index), BIGINT64_ELEMENTS));
         }
         BIND(&biguint64_elements);
         {
           Comment("BIGUINT64_ELEMENTS");
           exit_point->Return(LoadFixedTypedArrayElementAsTagged(
-              data_ptr, Unsigned(intptr_index), BIGUINT64_ELEMENTS));
+              data_ptr.value(), Unsigned(intptr_index), BIGUINT64_ELEMENTS));
         }
       }
     }
@@ -2460,7 +2571,7 @@ void AccessorAssembler::GenericPropertyLoad(
   {
     TNode<Object> value = CallGetterIfAccessor(
         var_value.value(), lookup_start_object, var_details.value(),
-        p->context(), p->receiver(), slow);
+        p->context(), p->receiver(), p->name(), slow);
     IncrementCounter(isolate()->counters()->ic_keyed_load_generic_symbol(), 1);
     Return(value);
   }
@@ -2864,11 +2975,23 @@ void AccessorAssembler::LoadIC_Noninlined(const LoadICParameters* p,
   DCHECK_EQ(MachineRepresentation::kTagged, var_handler->rep());
 
   {
-    // Check megamorphic case.
-    GotoIfNot(TaggedEqual(feedback, MegamorphicSymbolConstant()), miss);
+    Label try_megamorphic(this), try_megadom(this);
+    GotoIf(TaggedEqual(feedback, MegamorphicSymbolConstant()),
+           &try_megamorphic);
+    GotoIf(TaggedEqual(feedback, MegaDOMSymbolConstant()), &try_megadom);
+    Goto(miss);
 
-    TryProbeStubCache(isolate()->load_stub_cache(), p->lookup_start_object(),
-                      CAST(p->name()), if_handler, var_handler, miss);
+    BIND(&try_megamorphic);
+    {
+      TryProbeStubCache(isolate()->load_stub_cache(), p->lookup_start_object(),
+                        CAST(p->name()), if_handler, var_handler, miss);
+    }
+
+    BIND(&try_megadom);
+    {
+      TryMegaDOMCase(p->lookup_start_object(), lookup_start_object_map,
+                     var_handler, p->vector(), p->slot(), miss, exit_point);
+    }
   }
 }
 
@@ -2964,7 +3087,7 @@ void AccessorAssembler::LoadGlobalIC(TNode<HeapObject> maybe_feedback_vector,
   BIND(&no_feedback);
   {
     int ic_kind =
-        static_cast<int>((typeof_mode == INSIDE_TYPEOF)
+        static_cast<int>((typeof_mode == TypeofMode::kInside)
                              ? FeedbackSlotKind::kLoadGlobalInsideTypeof
                              : FeedbackSlotKind::kLoadGlobalNotInsideTypeof);
     exit_point->ReturnCallStub(
@@ -3023,7 +3146,7 @@ void AccessorAssembler::LoadGlobalIC_TryHandlerCase(
   TNode<Object> handler = CAST(feedback_element);
   GotoIf(TaggedEqual(handler, UninitializedSymbolConstant()), miss);
 
-  OnNonExistent on_nonexistent = typeof_mode == NOT_INSIDE_TYPEOF
+  OnNonExistent on_nonexistent = typeof_mode == TypeofMode::kNotInside
                                      ? OnNonExistent::kThrowReferenceError
                                      : OnNonExistent::kReturnUndefined;
 
@@ -3958,7 +4081,7 @@ void AccessorAssembler::GenerateLookupContextBaseline(TypeofMode typeof_mode) {
   BIND(&slowpath);
   {
     auto name = Parameter<Object>(Descriptor::kName);
-    Runtime::FunctionId function_id = typeof_mode == INSIDE_TYPEOF
+    Runtime::FunctionId function_id = typeof_mode == TypeofMode::kInside
                                           ? Runtime::kLoadLookupSlotInsideTypeof
                                           : Runtime::kLoadLookupSlot;
     TailCallRuntime(function_id, context, name);
@@ -3990,7 +4113,7 @@ void AccessorAssembler::GenerateLookupGlobalICBaseline(TypeofMode typeof_mode) {
 
   // Slow path when we have to call out to the runtime
   BIND(&slowpath);
-  Runtime::FunctionId function_id = typeof_mode == INSIDE_TYPEOF
+  Runtime::FunctionId function_id = typeof_mode == TypeofMode::kInside
                                         ? Runtime::kLoadLookupSlotInsideTypeof
                                         : Runtime::kLoadLookupSlot;
   TailCallRuntime(function_id, context, name);
diff --git a/chromium/v8/src/ic/accessor-assembler.h b/chromium/v8/src/ic/accessor-assembler.h
index 79f8181af49..9aa15ae1b8e 100644
--- a/chromium/v8/src/ic/accessor-assembler.h
+++ b/chromium/v8/src/ic/accessor-assembler.h
@@ -311,6 +311,12 @@ class V8_EXPORT_PRIVATE AccessorAssembler : public CodeStubAssembler {
                              TVariable<MaybeObject>* var_handler,
                              Label* if_miss);
 
+  void TryMegaDOMCase(TNode<Object> lookup_start_object,
+                      TNode<Map> lookup_start_object_map,
+                      TVariable<MaybeObject>* var_handler, TNode<Object> vector,
+                      TNode<TaggedIndex> slot, Label* miss,
+                      ExitPoint* exit_point);
+
   // LoadIC implementation.
   void HandleLoadICHandlerCase(
       const LazyLoadICParameters* p, TNode<Object> handler, Label* miss,
diff --git a/chromium/v8/src/ic/call-optimization.cc b/chromium/v8/src/ic/call-optimization.cc
index 6521e831939..4cfd1464be2 100644
--- a/chromium/v8/src/ic/call-optimization.cc
+++ b/chromium/v8/src/ic/call-optimization.cc
@@ -8,11 +8,8 @@
 namespace v8 {
 namespace internal {
 
-CallOptimization::CallOptimization(Isolate* isolate, Handle<Object> function) {
-  constant_function_ = Handle<JSFunction>::null();
-  is_simple_api_call_ = false;
-  expected_receiver_type_ = Handle<FunctionTemplateInfo>::null();
-  api_call_info_ = Handle<CallHandlerInfo>::null();
+template <class IsolateT>
+CallOptimization::CallOptimization(IsolateT* isolate, Handle<Object> function) {
   if (function->IsJSFunction()) {
     Initialize(isolate, Handle<JSFunction>::cast(function));
   } else if (function->IsFunctionTemplateInfo()) {
@@ -20,6 +17,12 @@ CallOptimization::CallOptimization(Isolate* isolate, Handle<Object> function) {
   }
 }
 
+// Instantiations.
+template CallOptimization::CallOptimization(Isolate* isolate,
+                                            Handle<Object> function);
+template CallOptimization::CallOptimization(LocalIsolate* isolate,
+                                            Handle<Object> function);
+
 Context CallOptimization::GetAccessorContext(Map holder_map) const {
   if (is_constant_call()) {
     return constant_function_->context().native_context();
@@ -35,8 +38,10 @@ bool CallOptimization::IsCrossContextLazyAccessorPair(Context native_context,
   return native_context != GetAccessorContext(holder_map);
 }
 
+template <class IsolateT>
 Handle<JSObject> CallOptimization::LookupHolderOfExpectedType(
-    Handle<Map> object_map, HolderLookup* holder_lookup) const {
+    IsolateT* isolate, Handle<Map> object_map,
+    HolderLookup* holder_lookup) const {
   DCHECK(is_simple_api_call());
   if (!object_map->IsJSObjectMap()) {
     *holder_lookup = kHolderNotFound;
@@ -49,8 +54,8 @@ Handle<JSObject> CallOptimization::LookupHolderOfExpectedType(
   }
   if (object_map->IsJSGlobalProxyMap() && !object_map->prototype().IsNull()) {
     JSObject raw_prototype = JSObject::cast(object_map->prototype());
-    Handle<JSObject> prototype(raw_prototype, raw_prototype.GetIsolate());
-    object_map = handle(prototype->map(), prototype->GetIsolate());
+    Handle<JSObject> prototype(raw_prototype, isolate);
+    object_map = handle(prototype->map(), isolate);
     if (expected_receiver_type_->IsTemplateFor(*object_map)) {
       *holder_lookup = kHolderFound;
       return prototype;
@@ -60,6 +65,14 @@ Handle<JSObject> CallOptimization::LookupHolderOfExpectedType(
   return Handle<JSObject>::null();
 }
 
+// Instantiations.
+template Handle<JSObject> CallOptimization::LookupHolderOfExpectedType(
+    Isolate* isolate, Handle<Map> object_map,
+    HolderLookup* holder_lookup) const;
+template Handle<JSObject> CallOptimization::LookupHolderOfExpectedType(
+    LocalIsolate* isolate, Handle<Map> object_map,
+    HolderLookup* holder_lookup) const;
+
 bool CallOptimization::IsCompatibleReceiverMap(
     Handle<JSObject> api_holder, Handle<JSObject> holder,
     HolderLookup holder_lookup) const {
@@ -86,8 +99,9 @@ bool CallOptimization::IsCompatibleReceiverMap(
   UNREACHABLE();
 }
 
+template <class IsolateT>
 void CallOptimization::Initialize(
-    Isolate* isolate, Handle<FunctionTemplateInfo> function_template_info) {
+    IsolateT* isolate, Handle<FunctionTemplateInfo> function_template_info) {
   HeapObject call_code = function_template_info->call_code(kAcquireLoad);
   if (call_code.IsUndefined(isolate)) return;
   api_call_info_ = handle(CallHandlerInfo::cast(call_code), isolate);
@@ -98,9 +112,11 @@ void CallOptimization::Initialize(
         handle(FunctionTemplateInfo::cast(signature), isolate);
   }
   is_simple_api_call_ = true;
+  accept_any_receiver_ = function_template_info->accept_any_receiver();
 }
 
-void CallOptimization::Initialize(Isolate* isolate,
+template <class IsolateT>
+void CallOptimization::Initialize(IsolateT* isolate,
                                   Handle<JSFunction> function) {
   if (function.is_null() || !function->is_compiled()) return;
 
@@ -108,7 +124,8 @@ void CallOptimization::Initialize(Isolate* isolate,
   AnalyzePossibleApiFunction(isolate, function);
 }
 
-void CallOptimization::AnalyzePossibleApiFunction(Isolate* isolate,
+template <class IsolateT>
+void CallOptimization::AnalyzePossibleApiFunction(IsolateT* isolate,
                                                   Handle<JSFunction> function) {
   if (!function->shared().IsApiFunction()) return;
   Handle<FunctionTemplateInfo> info(function->shared().get_api_func_data(),
@@ -125,6 +142,7 @@ void CallOptimization::AnalyzePossibleApiFunction(Isolate* isolate,
   }
 
   is_simple_api_call_ = true;
+  accept_any_receiver_ = info->accept_any_receiver();
 }
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/ic/call-optimization.h b/chromium/v8/src/ic/call-optimization.h
index b6d49a1bf90..ca5c8aa7ef8 100644
--- a/chromium/v8/src/ic/call-optimization.h
+++ b/chromium/v8/src/ic/call-optimization.h
@@ -10,16 +10,22 @@
 
 namespace v8 {
 namespace internal {
+
 // Holds information about possible function call optimizations.
 class CallOptimization {
  public:
-  CallOptimization(Isolate* isolate, Handle<Object> function);
+  template <class IsolateT>
+  CallOptimization(IsolateT* isolate, Handle<Object> function);
 
   Context GetAccessorContext(Map holder_map) const;
   bool IsCrossContextLazyAccessorPair(Context native_context,
                                       Map holder_map) const;
 
   bool is_constant_call() const { return !constant_function_.is_null(); }
+  bool accept_any_receiver() const { return accept_any_receiver_; }
+  bool requires_signature_check() const {
+    return !expected_receiver_type_.is_null();
+  }
 
   Handle<JSFunction> constant_function() const {
     DCHECK(is_constant_call());
@@ -39,27 +45,38 @@ class CallOptimization {
   }
 
   enum HolderLookup { kHolderNotFound, kHolderIsReceiver, kHolderFound };
+
+  template <class IsolateT>
   Handle<JSObject> LookupHolderOfExpectedType(
-      Handle<Map> receiver_map, HolderLookup* holder_lookup) const;
+      IsolateT* isolate, Handle<Map> receiver_map,
+      HolderLookup* holder_lookup) const;
 
   bool IsCompatibleReceiverMap(Handle<JSObject> api_holder,
                                Handle<JSObject> holder, HolderLookup) const;
 
  private:
-  void Initialize(Isolate* isolate, Handle<JSFunction> function);
-  void Initialize(Isolate* isolate,
+  template <class IsolateT>
+  void Initialize(IsolateT* isolate, Handle<JSFunction> function);
+  template <class IsolateT>
+  void Initialize(IsolateT* isolate,
                   Handle<FunctionTemplateInfo> function_template_info);
 
   // Determines whether the given function can be called using the
   // fast api call builtin.
-  void AnalyzePossibleApiFunction(Isolate* isolate,
+  template <class IsolateT>
+  void AnalyzePossibleApiFunction(IsolateT* isolate,
                                   Handle<JSFunction> function);
 
   Handle<JSFunction> constant_function_;
-  bool is_simple_api_call_;
   Handle<FunctionTemplateInfo> expected_receiver_type_;
   Handle<CallHandlerInfo> api_call_info_;
+
+  // TODO(gsathya): Change these to be a bitfield and do a single fast check
+  // rather than two checks.
+  bool is_simple_api_call_ = false;
+  bool accept_any_receiver_ = false;
 };
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/chromium/v8/src/ic/ic.cc b/chromium/v8/src/ic/ic.cc
index 81e31d1c2d8..09f1815c1c0 100644
--- a/chromium/v8/src/ic/ic.cc
+++ b/chromium/v8/src/ic/ic.cc
@@ -33,6 +33,7 @@
 #include "src/objects/heap-number-inl.h"
 #include "src/objects/js-array-buffer-inl.h"
 #include "src/objects/js-array-inl.h"
+#include "src/objects/megadom-handler.h"
 #include "src/objects/module-inl.h"
 #include "src/objects/prototype.h"
 #include "src/objects/struct-inl.h"
@@ -59,6 +60,8 @@ char IC::TransitionMarkFromState(IC::State state) {
       return 'P';
     case MEGAMORPHIC:
       return 'N';
+    case MEGADOM:
+      return 'D';
     case GENERIC:
       return 'G';
   }
@@ -519,9 +522,12 @@ MaybeHandle<Object> LoadGlobalIC::Load(Handle<Name> name,
 
       bool use_ic = (state() != NO_FEEDBACK) && FLAG_use_ic && update_feedback;
       if (use_ic) {
+        // 'const' Variables are mutable if REPL mode is enabled. This disables
+        // compiler inlining for all 'const' variables declared in REPL mode.
         if (nexus()->ConfigureLexicalVarMode(
                 lookup_result.context_index, lookup_result.slot_index,
-                lookup_result.mode == VariableMode::kConst)) {
+                (lookup_result.mode == VariableMode::kConst &&
+                 !lookup_result.is_repl_mode))) {
           TRACE_HANDLER_STATS(isolate(), LoadGlobalIC_LoadScriptContextField);
         } else {
           // Given combination of indices can't be encoded, so use slow stub.
@@ -566,6 +572,55 @@ static bool AddOneReceiverMapIfMissing(
   return true;
 }
 
+bool IC::UpdateMegaDOMIC(const MaybeObjectHandle& handler, Handle<Name> name) {
+  if (!FLAG_enable_mega_dom_ic) return false;
+
+  // TODO(gsathya): Enable fuzzing once this feature is more stable.
+  if (FLAG_fuzzing) return false;
+
+  // TODO(gsathya): Support KeyedLoadIC, StoreIC and KeyedStoreIC.
+  if (!IsLoadIC()) return false;
+
+  // Check if DOM protector cell is valid.
+  if (!Protectors::IsMegaDOMIntact(isolate())) return false;
+
+  // Check if current lookup object is an API object
+  Handle<Map> map = lookup_start_object_map();
+  if (!InstanceTypeChecker::IsJSApiObject(map->instance_type())) return false;
+
+  Handle<Object> accessor_obj;
+  // TODO(gsathya): Check if there are overloads possible for this accessor and
+  // transition only if it isn't possible.
+  if (!accessor().ToHandle(&accessor_obj)) return false;
+
+  // TODO(gsathya): This is also created in IC::ComputeHandler, find a way to
+  // reuse it here.
+  CallOptimization call_optimization(isolate(), accessor_obj);
+
+  // Check if accessor is an API function
+  if (!call_optimization.is_simple_api_call()) return false;
+
+  // Check if accessor requires access checks
+  if (call_optimization.accept_any_receiver()) return false;
+
+  // Check if accessor requires signature checks
+  if (!call_optimization.requires_signature_check()) return false;
+
+  // Check if the receiver is the holder
+  CallOptimization::HolderLookup holder_lookup;
+  call_optimization.LookupHolderOfExpectedType(isolate(), map, &holder_lookup);
+  if (holder_lookup != CallOptimization::kHolderIsReceiver) return false;
+
+  Handle<Context> accessor_context(call_optimization.GetAccessorContext(*map),
+                                   isolate());
+
+  Handle<MegaDomHandler> new_handler = isolate()->factory()->NewMegaDomHandler(
+      MaybeObjectHandle::Weak(accessor_obj),
+      MaybeObjectHandle::Weak(accessor_context));
+  nexus()->ConfigureMegaDOM(MaybeObjectHandle(new_handler));
+  return true;
+}
+
 bool IC::UpdatePolymorphicIC(Handle<Name> name,
                              const MaybeObjectHandle& handler) {
   DCHECK(IsHandler(*handler));
@@ -703,9 +758,12 @@ void IC::SetCache(Handle<Name> name, const MaybeObjectHandle& handler) {
       V8_FALLTHROUGH;
     case POLYMORPHIC:
       if (UpdatePolymorphicIC(name, handler)) break;
+      if (UpdateMegaDOMIC(handler, name)) break;
       if (!is_keyed() || state() == RECOMPUTE_HANDLER) {
         CopyICToMegamorphicCache(name);
       }
+      V8_FALLTHROUGH;
+    case MEGADOM:
       ConfigureVectorState(MEGAMORPHIC, name);
       V8_FALLTHROUGH;
     case MEGAMORPHIC:
@@ -719,23 +777,20 @@ void IC::SetCache(Handle<Name> name, const MaybeObjectHandle& handler) {
 }
 
 void LoadIC::UpdateCaches(LookupIterator* lookup) {
-  Handle<Object> code;
+  Handle<Object> handler;
   if (lookup->state() == LookupIterator::ACCESS_CHECK) {
-    code = LoadHandler::LoadSlow(isolate());
+    handler = LoadHandler::LoadSlow(isolate());
   } else if (!lookup->IsFound()) {
     TRACE_HANDLER_STATS(isolate(), LoadIC_LoadNonexistentDH);
     Handle<Smi> smi_handler = LoadHandler::LoadNonExistent(isolate());
-    code = LoadHandler::LoadFullChain(
+    handler = LoadHandler::LoadFullChain(
         isolate(), lookup_start_object_map(),
         MaybeObjectHandle(isolate()->factory()->null_value()), smi_handler);
   } else if (IsLoadGlobalIC() && lookup->state() == LookupIterator::JSPROXY) {
     // If there is proxy just install the slow stub since we need to call the
     // HasProperty trap for global loads. The ProxyGetProperty builtin doesn't
     // handle this case.
-    Handle<Smi> slow_handler = LoadHandler::LoadSlow(isolate());
-    Handle<JSProxy> holder = lookup->GetHolder<JSProxy>();
-    code = LoadHandler::LoadFromPrototype(isolate(), lookup_start_object_map(),
-                                          holder, slow_handler);
+    handler = LoadHandler::LoadSlow(isolate());
   } else {
     if (IsLoadGlobalIC()) {
       if (lookup->TryLookupCachedProperty()) {
@@ -750,12 +805,12 @@ void LoadIC::UpdateCaches(LookupIterator* lookup) {
         return;
       }
     }
-    code = ComputeHandler(lookup);
+    handler = ComputeHandler(lookup);
   }
   // Can't use {lookup->name()} because the LookupIterator might be in
   // "elements" mode for keys that are strings representing integers above
   // JSArray::kMaxIndex.
-  SetCache(lookup->GetName(), code);
+  SetCache(lookup->GetName(), handler);
   TraceIC("LoadIC", lookup->GetName());
 }
 
@@ -877,6 +932,7 @@ Handle<Object> LoadIC::ComputeHandler(LookupIterator* lookup) {
           TRACE_HANDLER_STATS(isolate(), LoadIC_SlowStub);
           return LoadHandler::LoadSlow(isolate());
         }
+        set_accessor(getter);
 
         if ((getter->IsFunctionTemplateInfo() &&
              FunctionTemplateInfo::cast(*getter).BreakAtEntry()) ||
@@ -893,7 +949,8 @@ Handle<Object> LoadIC::ComputeHandler(LookupIterator* lookup) {
         if (call_optimization.is_simple_api_call()) {
           CallOptimization::HolderLookup holder_lookup;
           Handle<JSObject> api_holder =
-              call_optimization.LookupHolderOfExpectedType(map, &holder_lookup);
+              call_optimization.LookupHolderOfExpectedType(isolate(), map,
+                                                           &holder_lookup);
 
           if (!call_optimization.IsCompatibleReceiverMap(api_holder, holder,
                                                          holder_lookup) ||
@@ -1209,7 +1266,7 @@ Handle<Object> KeyedLoadIC::LoadElementHandler(Handle<Map> receiver_map,
   }
   DCHECK(IsFastElementsKind(elements_kind) ||
          IsAnyNonextensibleElementsKind(elements_kind) ||
-         IsTypedArrayElementsKind(elements_kind));
+         IsTypedArrayOrRabGsabTypedArrayElementsKind(elements_kind));
   bool convert_hole_to_undefined =
       (elements_kind == HOLEY_SMI_ELEMENTS ||
        elements_kind == HOLEY_ELEMENTS) &&
@@ -1325,7 +1382,7 @@ bool IsOutOfBoundsAccess(Handle<Object> receiver, size_t index) {
   if (receiver->IsJSArray()) {
     length = JSArray::cast(*receiver).length().Number();
   } else if (receiver->IsJSTypedArray()) {
-    length = JSTypedArray::cast(*receiver).length();
+    length = JSTypedArray::cast(*receiver).GetLength();
   } else if (receiver->IsJSObject()) {
     length = JSObject::cast(*receiver).elements().length();
   } else if (receiver->IsString()) {
@@ -1756,7 +1813,7 @@ MaybeObjectHandle StoreIC::ComputeHandler(LookupIterator* lookup) {
           CallOptimization::HolderLookup holder_lookup;
           Handle<JSObject> api_holder =
               call_optimization.LookupHolderOfExpectedType(
-                  lookup_start_object_map(), &holder_lookup);
+                  isolate(), lookup_start_object_map(), &holder_lookup);
           if (call_optimization.IsCompatibleReceiverMap(api_holder, holder,
                                                         holder_lookup)) {
             Handle<Smi> smi_handler = StoreHandler::StoreApiSetter(
@@ -1975,7 +2032,7 @@ void KeyedStoreIC::UpdateStoreElement(Handle<Map> receiver_map,
             "unsupported combination of arrays (potentially read-only length)");
         return;
 
-      } else if (map->has_typed_array_elements()) {
+      } else if (map->has_typed_array_or_rab_gsab_typed_array_elements()) {
         DCHECK(!IsStoreInArrayLiteralICKind(kind()));
         external_arrays++;
       }
@@ -2029,7 +2086,9 @@ Handle<Object> KeyedStoreIC::StoreElementHandler(
              receiver_map->has_typed_array_elements()) {
     TRACE_HANDLER_STATS(isolate(), KeyedStoreIC_StoreFastElementStub);
     code = CodeFactory::StoreFastElementIC(isolate(), store_mode).code();
-    if (receiver_map->has_typed_array_elements()) return code;
+    if (receiver_map->has_typed_array_elements()) {
+      return code;
+    }
   } else if (IsStoreInArrayLiteralICKind(kind())) {
     // TODO(jgruber): Update counter name.
     TRACE_HANDLER_STATS(isolate(), StoreInArrayLiteralIC_SlowStub);
@@ -2038,7 +2097,9 @@ Handle<Object> KeyedStoreIC::StoreElementHandler(
     // TODO(jgruber): Update counter name.
     TRACE_HANDLER_STATS(isolate(), KeyedStoreIC_StoreElementStub);
     DCHECK(DICTIONARY_ELEMENTS == receiver_map->elements_kind() ||
-           receiver_map->has_frozen_elements());
+           receiver_map->has_frozen_elements() ||
+           receiver_map->has_rab_gsab_typed_array_elements());
+    // TODO(v8:11111): Add fast paths for RAB / GSAB.
     code = StoreHandler::StoreSlow(isolate(), store_mode);
   }
 
@@ -2416,7 +2477,7 @@ RUNTIME_FUNCTION(Runtime_LoadGlobalIC_Miss) {
     vector = Handle<FeedbackVector>::cast(maybe_vector);
   }
 
-  FeedbackSlotKind kind = (typeof_mode == TypeofMode::INSIDE_TYPEOF)
+  FeedbackSlotKind kind = (typeof_mode == TypeofMode::kInside)
                               ? FeedbackSlotKind::kLoadGlobalInsideTypeof
                               : FeedbackSlotKind::kLoadGlobalNotInsideTypeof;
   LoadGlobalIC ic(isolate, vector, vector_slot, kind);
diff --git a/chromium/v8/src/ic/ic.h b/chromium/v8/src/ic/ic.h
index 170ee609cb4..ddac48e38e2 100644
--- a/chromium/v8/src/ic/ic.h
+++ b/chromium/v8/src/ic/ic.h
@@ -67,6 +67,8 @@ class IC {
 
  protected:
   void set_slow_stub_reason(const char* reason) { slow_stub_reason_ = reason; }
+  void set_accessor(Handle<Object> accessor) { accessor_ = accessor; }
+  MaybeHandle<Object> accessor() const { return accessor_; }
 
   Isolate* isolate() const { return isolate_; }
 
@@ -96,6 +98,7 @@ class IC {
   MaybeHandle<Object> ReferenceError(Handle<Name> name);
 
   void UpdateMonomorphicIC(const MaybeObjectHandle& handler, Handle<Name> name);
+  bool UpdateMegaDOMIC(const MaybeObjectHandle& handler, Handle<Name> name);
   bool UpdatePolymorphicIC(Handle<Name> name, const MaybeObjectHandle& handler);
   void UpdateMegamorphicCache(Handle<Map> map, Handle<Name> name,
                               const MaybeObjectHandle& handler);
@@ -154,7 +157,7 @@ class IC {
   State state_;
   FeedbackSlotKind kind_;
   Handle<Map> lookup_start_object_map_;
-
+  MaybeHandle<Object> accessor_;
   MapHandles target_maps_;
   bool target_maps_set_;
 
diff --git a/chromium/v8/src/ic/keyed-store-generic.cc b/chromium/v8/src/ic/keyed-store-generic.cc
index b07ea644836..8218d3d5211 100644
--- a/chromium/v8/src/ic/keyed-store-generic.cc
+++ b/chromium/v8/src/ic/keyed-store-generic.cc
@@ -568,7 +568,8 @@ void KeyedStoreGenericAssembler::EmitGenericElementStore(
   // dispatch.
   BIND(&if_nonfast);
   {
-    STATIC_ASSERT(LAST_ELEMENTS_KIND == LAST_FIXED_TYPED_ARRAY_ELEMENTS_KIND);
+    STATIC_ASSERT(LAST_ELEMENTS_KIND ==
+                  LAST_RAB_GSAB_FIXED_TYPED_ARRAY_ELEMENTS_KIND);
     GotoIf(Int32GreaterThanOrEqual(
                elements_kind,
                Int32Constant(FIRST_FIXED_TYPED_ARRAY_ELEMENTS_KIND)),
@@ -588,7 +589,8 @@ void KeyedStoreGenericAssembler::EmitGenericElementStore(
   BIND(&if_typed_array);
   {
     Comment("Typed array");
-    // TODO(jkummerow): Support typed arrays.
+    // TODO(jkummerow): Support typed arrays. Note: RAB / GSAB backed typed
+    // arrays end up here too.
     Goto(slow);
   }
 }
diff --git a/chromium/v8/src/init/bootstrapper.cc b/chromium/v8/src/init/bootstrapper.cc
index 7b1e7a196bd..1f00716b631 100644
--- a/chromium/v8/src/init/bootstrapper.cc
+++ b/chromium/v8/src/init/bootstrapper.cc
@@ -235,6 +235,8 @@ class Genesis {
   enum ArrayBufferKind {
     ARRAY_BUFFER,
     SHARED_ARRAY_BUFFER,
+    RESIZABLE_ARRAY_BUFFER,
+    GROWABLE_SHARED_ARRAY_BUFFER
   };
   Handle<JSFunction> CreateArrayBuffer(Handle<String> name,
                                        ArrayBufferKind array_buffer_kind);
@@ -244,7 +246,8 @@ class Genesis {
 
   Handle<JSFunction> InstallTypedArray(const char* name,
                                        ElementsKind elements_kind,
-                                       InstanceType type);
+                                       InstanceType type,
+                                       int rab_gsab_initial_map_index);
   void InitializeNormalizedMapCaches();
 
   enum ExtensionTraversalState { UNVISITED, VISITED, INSTALLED };
@@ -364,7 +367,8 @@ void Bootstrapper::DetachGlobal(Handle<Context> env) {
   ReadOnlyRoots roots(isolate_);
   Handle<JSGlobalProxy> global_proxy(env->global_proxy(), isolate_);
   global_proxy->set_native_context(roots.null_value());
-  JSObject::ForceSetPrototype(global_proxy, isolate_->factory()->null_value());
+  JSObject::ForceSetPrototype(isolate_, global_proxy,
+                              isolate_->factory()->null_value());
   global_proxy->map().SetConstructor(roots.null_value());
   if (FLAG_track_detached_contexts) {
     isolate_->AddDetachedContext(env);
@@ -921,10 +925,11 @@ void Genesis::CreateIteratorMaps(Handle<JSFunction> empty) {
       isolate()->object_function(), AllocationType::kOld);
   native_context()->set_initial_generator_prototype(
       *generator_object_prototype);
-  JSObject::ForceSetPrototype(generator_object_prototype, iterator_prototype);
+  JSObject::ForceSetPrototype(isolate(), generator_object_prototype,
+                              iterator_prototype);
   Handle<JSObject> generator_function_prototype = factory()->NewJSObject(
       isolate()->object_function(), AllocationType::kOld);
-  JSObject::ForceSetPrototype(generator_function_prototype, empty);
+  JSObject::ForceSetPrototype(isolate(), generator_function_prototype, empty);
 
   InstallToStringTag(isolate(), generator_function_prototype,
                      "GeneratorFunction");
@@ -1032,7 +1037,7 @@ void Genesis::CreateAsyncIteratorMaps(Handle<JSFunction> empty) {
   InstallToStringTag(isolate(), async_from_sync_iterator_prototype,
                      "Async-from-Sync Iterator");
 
-  JSObject::ForceSetPrototype(async_from_sync_iterator_prototype,
+  JSObject::ForceSetPrototype(isolate(), async_from_sync_iterator_prototype,
                               async_iterator_prototype);
 
   Handle<Map> async_from_sync_iterator_map = factory()->NewMap(
@@ -1049,7 +1054,8 @@ void Genesis::CreateAsyncIteratorMaps(Handle<JSFunction> empty) {
       isolate()->object_function(), AllocationType::kOld);
 
   // %AsyncGenerator% / %AsyncGeneratorFunction%.prototype
-  JSObject::ForceSetPrototype(async_generator_function_prototype, empty);
+  JSObject::ForceSetPrototype(isolate(), async_generator_function_prototype,
+                              empty);
 
   // The value of AsyncGeneratorFunction.prototype.prototype is the
   //     %AsyncGeneratorPrototype% intrinsic object.
@@ -1067,7 +1073,7 @@ void Genesis::CreateAsyncIteratorMaps(Handle<JSFunction> empty) {
                      "AsyncGeneratorFunction");
 
   // %AsyncGeneratorPrototype%
-  JSObject::ForceSetPrototype(async_generator_object_prototype,
+  JSObject::ForceSetPrototype(isolate(), async_generator_object_prototype,
                               async_iterator_prototype);
   native_context()->set_initial_async_generator_prototype(
       *async_generator_object_prototype);
@@ -1110,7 +1116,7 @@ void Genesis::CreateAsyncFunctionMaps(Handle<JSFunction> empty) {
   // %AsyncFunctionPrototype% intrinsic
   Handle<JSObject> async_function_prototype = factory()->NewJSObject(
       isolate()->object_function(), AllocationType::kOld);
-  JSObject::ForceSetPrototype(async_function_prototype, empty);
+  JSObject::ForceSetPrototype(isolate(), async_function_prototype, empty);
 
   InstallToStringTag(isolate(), async_function_prototype, "AsyncFunction");
 
@@ -1367,7 +1373,7 @@ void Genesis::HookUpGlobalProxy(Handle<JSGlobalProxy> global_proxy) {
   factory()->ReinitializeJSGlobalProxy(global_proxy, global_proxy_function);
   Handle<JSObject> global_object(
       JSObject::cast(native_context()->global_object()), isolate());
-  JSObject::ForceSetPrototype(global_proxy, global_object);
+  JSObject::ForceSetPrototype(isolate(), global_proxy, global_object);
   global_proxy->set_native_context(*native_context());
   DCHECK(native_context()->global_proxy() == *global_proxy);
 }
@@ -1394,7 +1400,8 @@ static void InstallWithIntrinsicDefaultProto(Isolate* isolate,
   JSObject::AddProperty(isolate, function,
                         isolate->factory()->native_context_index_symbol(),
                         index, NONE);
-  isolate->native_context()->set(context_index, *function);
+  isolate->native_context()->set(context_index, *function, UPDATE_WRITE_BARRIER,
+                                 kReleaseStore);
 }
 
 static void InstallError(
@@ -1404,6 +1411,11 @@ static void InstallError(
     int error_function_length = 1, int in_object_properties = 2) {
   Factory* factory = isolate->factory();
 
+  if (FLAG_harmony_error_cause) {
+    error_function_length += 1;
+    in_object_properties += 1;
+  }
+
   // Most Error objects consist of a message and a stack trace.
   // Reserve two in-object properties for these.
   const int kErrorObjectSize =
@@ -1411,7 +1423,6 @@ static void InstallError(
   Handle<JSFunction> error_fun = InstallFunction(
       isolate, global, name, JS_ERROR_TYPE, kErrorObjectSize,
       in_object_properties, factory->the_hole_value(), error_constructor);
-  error_fun->shared().DontAdaptArguments();
   error_fun->shared().set_length(error_function_length);
 
   if (context_index == Context::ERROR_FUNCTION_INDEX) {
@@ -1431,6 +1442,11 @@ static void InstallError(
     JSObject::AddProperty(isolate, prototype, factory->message_string(),
                           factory->empty_string(), DONT_ENUM);
 
+    if (FLAG_harmony_error_cause) {
+      JSObject::AddProperty(isolate, prototype, factory->cause_string(),
+                            factory->undefined_value(), DONT_ENUM);
+    }
+
     if (context_index == Context::ERROR_FUNCTION_INDEX) {
       Handle<JSFunction> to_string_fun =
           SimpleInstallFunction(isolate, prototype, "toString",
@@ -1465,7 +1481,6 @@ static void InstallError(
 void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                                Handle<JSFunction> empty_function) {
   // --- N a t i v e   C o n t e x t ---
-  native_context()->set_previous(Context());
   // Set extension and global object.
   native_context()->set_extension(*global_object);
   // Security setup: Set the security token of the native context to the global
@@ -1626,8 +1641,8 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                         JSFunction::kSizeWithPrototype, 0, prototype,
                         Builtins::kFunctionConstructor);
     // Function instances are sloppy by default.
-    function_fun->set_prototype_or_initial_map(
-        *isolate_->sloppy_function_map());
+    function_fun->set_prototype_or_initial_map(*isolate_->sloppy_function_map(),
+                                               kReleaseStore);
     function_fun->shared().DontAdaptArguments();
     function_fun->shared().set_length(1);
     InstallWithIntrinsicDefaultProto(isolate_, function_fun,
@@ -1636,8 +1651,10 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     // Setup the methods on the %FunctionPrototype%.
     JSObject::AddProperty(isolate_, prototype, factory->constructor_string(),
                           function_fun, DONT_ENUM);
-    SimpleInstallFunction(isolate_, prototype, "apply",
-                          Builtins::kFunctionPrototypeApply, 2, false);
+    Handle<JSFunction> function_prototype_apply =
+        SimpleInstallFunction(isolate_, prototype, "apply",
+                              Builtins::kFunctionPrototypeApply, 2, false);
+    native_context()->set_function_prototype_apply(*function_prototype_apply);
     SimpleInstallFunction(isolate_, prototype, "bind",
                           Builtins::kFastFunctionPrototypeBind, 1, false);
     SimpleInstallFunction(isolate_, prototype, "call",
@@ -1829,7 +1846,8 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
 
     Handle<JSObject> array_iterator_prototype =
         factory->NewJSObject(isolate_->object_function(), AllocationType::kOld);
-    JSObject::ForceSetPrototype(array_iterator_prototype, iterator_prototype);
+    JSObject::ForceSetPrototype(isolate(), array_iterator_prototype,
+                                iterator_prototype);
     CHECK_NE(array_iterator_prototype->map().ptr(),
              isolate_->initial_object_prototype()->map().ptr());
     array_iterator_prototype->map().set_instance_type(
@@ -2145,7 +2163,8 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
 
     Handle<JSObject> string_iterator_prototype =
         factory->NewJSObject(isolate_->object_function(), AllocationType::kOld);
-    JSObject::ForceSetPrototype(string_iterator_prototype, iterator_prototype);
+    JSObject::ForceSetPrototype(isolate(), string_iterator_prototype,
+                                iterator_prototype);
     CHECK_NE(string_iterator_prototype->map().ptr(),
              isolate_->initial_object_prototype()->map().ptr());
     string_iterator_prototype->map().set_instance_type(
@@ -2623,7 +2642,7 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
 
     Handle<JSObject> regexp_string_iterator_prototype = factory->NewJSObject(
         isolate()->object_function(), AllocationType::kOld);
-    JSObject::ForceSetPrototype(regexp_string_iterator_prototype,
+    JSObject::ForceSetPrototype(isolate(), regexp_string_iterator_prototype,
                                 iterator_prototype);
 
     InstallToStringTag(isolate(), regexp_string_iterator_prototype,
@@ -3222,7 +3241,7 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
             native_context()->initial_iterator_prototype(), isolate());
         Handle<JSObject> prototype = factory->NewJSObject(
             isolate()->object_function(), AllocationType::kOld);
-        JSObject::ForceSetPrototype(prototype, iterator_prototype);
+        JSObject::ForceSetPrototype(isolate(), prototype, iterator_prototype);
         // #sec-%segmentiteratorprototype%.@@tostringtag
         //
         // %SegmentIteratorPrototype% [ @@toStringTag ]
@@ -3274,6 +3293,25 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     InstallSpeciesGetter(isolate_, shared_array_buffer_fun);
   }
 
+  {  // R e s i z a b l e A r r a y B u f f e r
+    Handle<String> name = factory->ResizableArrayBuffer_string();
+    Handle<JSFunction> resizable_array_buffer_fun =
+        CreateArrayBuffer(name, RESIZABLE_ARRAY_BUFFER);
+    InstallWithIntrinsicDefaultProto(isolate_, resizable_array_buffer_fun,
+                                     Context::RESIZABLE_ARRAY_BUFFER_FUN_INDEX);
+    InstallSpeciesGetter(isolate_, resizable_array_buffer_fun);
+  }
+
+  {  // G r o w a b l e S h a r e d A r r a y B u f f e r
+    Handle<String> name = factory->GrowableSharedArrayBuffer_string();
+    Handle<JSFunction> growable_shared_array_buffer_fun =
+        CreateArrayBuffer(name, GROWABLE_SHARED_ARRAY_BUFFER);
+    InstallWithIntrinsicDefaultProto(
+        isolate_, growable_shared_array_buffer_fun,
+        Context::GROWABLE_SHARED_ARRAY_BUFFER_FUN_INDEX);
+    InstallSpeciesGetter(isolate_, growable_shared_array_buffer_fun);
+  }
+
   {  // -- A t o m i c s
     Handle<JSObject> atomics_object =
         factory->NewJSObject(isolate_->object_function(), AllocationType::kOld);
@@ -3403,12 +3441,13 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
   }
 
   {// -- T y p e d A r r a y s
-#define INSTALL_TYPED_ARRAY(Type, type, TYPE, ctype)                          \
-  {                                                                           \
-    Handle<JSFunction> fun = InstallTypedArray(                               \
-        #Type "Array", TYPE##_ELEMENTS, TYPE##_TYPED_ARRAY_CONSTRUCTOR_TYPE); \
-    InstallWithIntrinsicDefaultProto(isolate_, fun,                           \
-                                     Context::TYPE##_ARRAY_FUN_INDEX);        \
+#define INSTALL_TYPED_ARRAY(Type, type, TYPE, ctype)                         \
+  {                                                                          \
+    Handle<JSFunction> fun = InstallTypedArray(                              \
+        #Type "Array", TYPE##_ELEMENTS, TYPE##_TYPED_ARRAY_CONSTRUCTOR_TYPE, \
+        Context::RAB_GSAB_##TYPE##_ARRAY_MAP_INDEX);                         \
+    InstallWithIntrinsicDefaultProto(isolate_, fun,                          \
+                                     Context::TYPE##_ARRAY_FUN_INDEX);       \
   }
   TYPED_ARRAYS(INSTALL_TYPED_ARRAY)
 #undef INSTALL_TYPED_ARRAY
@@ -3862,6 +3901,61 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     native_context()->set_bound_function_with_constructor_map(*map);
   }
 
+  {  // -- F i n a l i z a t i o n R e g i s t r y
+    Handle<JSFunction> finalization_registry_fun = InstallFunction(
+        isolate_, global, factory->FinalizationRegistry_string(),
+        JS_FINALIZATION_REGISTRY_TYPE, JSFinalizationRegistry::kHeaderSize, 0,
+        factory->the_hole_value(), Builtins::kFinalizationRegistryConstructor);
+    InstallWithIntrinsicDefaultProto(
+        isolate_, finalization_registry_fun,
+        Context::JS_FINALIZATION_REGISTRY_FUNCTION_INDEX);
+
+    finalization_registry_fun->shared().DontAdaptArguments();
+    finalization_registry_fun->shared().set_length(1);
+
+    Handle<JSObject> finalization_registry_prototype(
+        JSObject::cast(finalization_registry_fun->instance_prototype()),
+        isolate());
+
+    InstallToStringTag(isolate_, finalization_registry_prototype,
+                       factory->FinalizationRegistry_string());
+
+    SimpleInstallFunction(isolate_, finalization_registry_prototype, "register",
+                          Builtins::kFinalizationRegistryRegister, 2, false);
+
+    SimpleInstallFunction(isolate_, finalization_registry_prototype,
+                          "unregister",
+                          Builtins::kFinalizationRegistryUnregister, 1, false);
+
+    // The cleanupSome function is created but not exposed, as it is used
+    // internally by InvokeFinalizationRegistryCleanupFromTask.
+    //
+    // It is exposed by FLAG_harmony_weak_refs_with_cleanup_some.
+    Handle<JSFunction> cleanup_some_fun = SimpleCreateFunction(
+        isolate_, factory->InternalizeUtf8String("cleanupSome"),
+        Builtins::kFinalizationRegistryPrototypeCleanupSome, 0, false);
+    native_context()->set_finalization_registry_cleanup_some(*cleanup_some_fun);
+  }
+
+  {  // -- W e a k R e f
+    Handle<JSFunction> weak_ref_fun = InstallFunction(
+        isolate_, global, "WeakRef", JS_WEAK_REF_TYPE, JSWeakRef::kHeaderSize,
+        0, factory->the_hole_value(), Builtins::kWeakRefConstructor);
+    InstallWithIntrinsicDefaultProto(isolate_, weak_ref_fun,
+                                     Context::JS_WEAK_REF_FUNCTION_INDEX);
+
+    weak_ref_fun->shared().DontAdaptArguments();
+    weak_ref_fun->shared().set_length(1);
+
+    Handle<JSObject> weak_ref_prototype(
+        JSObject::cast(weak_ref_fun->instance_prototype()), isolate());
+
+    InstallToStringTag(isolate_, weak_ref_prototype, factory->WeakRef_string());
+
+    SimpleInstallFunction(isolate_, weak_ref_prototype, "deref",
+                          Builtins::kWeakRefDeref, 0, true);
+  }
+
   {  // --- sloppy arguments map
     Handle<String> arguments_string = factory->Arguments_string();
     Handle<JSFunction> function = CreateFunctionForBuiltinWithPrototype(
@@ -3984,7 +4078,8 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
 
 Handle<JSFunction> Genesis::InstallTypedArray(const char* name,
                                               ElementsKind elements_kind,
-                                              InstanceType type) {
+                                              InstanceType type,
+                                              int rab_gsab_initial_map_index) {
   Handle<JSObject> global =
       Handle<JSObject>(native_context()->global_object(), isolate());
 
@@ -4021,6 +4116,16 @@ Handle<JSFunction> Genesis::InstallTypedArray(const char* name,
   prototype->map().set_instance_type(JS_TYPED_ARRAY_PROTOTYPE_TYPE);
 
   InstallConstant(isolate(), prototype, "BYTES_PER_ELEMENT", bytes_per_element);
+
+  // RAB / GSAB backed TypedArrays don't have separate constructors, but they
+  // have their own maps. Create the corresponding map here.
+  Handle<Map> rab_gsab_initial_map = factory()->NewMap(
+      JS_TYPED_ARRAY_TYPE, JSTypedArray::kSizeWithEmbedderFields,
+      GetCorrespondingRabGsabElementsKind(elements_kind), 0);
+  native_context()->set(rab_gsab_initial_map_index, *rab_gsab_initial_map,
+                        UPDATE_WRITE_BARRIER, kReleaseStore);
+  Map::SetPrototype(isolate(), rab_gsab_initial_map, prototype);
+
   return result;
 }
 
@@ -4099,14 +4204,14 @@ void Genesis::InitializeIteratorFunctions() {
         JSFunction::kSizeWithPrototype, 0, generator_function_prototype,
         Builtins::kGeneratorFunctionConstructor);
     generator_function_function->set_prototype_or_initial_map(
-        native_context->generator_function_map());
+        native_context->generator_function_map(), kReleaseStore);
     generator_function_function->shared().DontAdaptArguments();
     generator_function_function->shared().set_length(1);
     InstallWithIntrinsicDefaultProto(
         isolate, generator_function_function,
         Context::GENERATOR_FUNCTION_FUNCTION_INDEX);
 
-    JSObject::ForceSetPrototype(generator_function_function,
+    JSObject::ForceSetPrototype(isolate, generator_function_function,
                                 isolate->function_function());
     JSObject::AddProperty(
         isolate, generator_function_prototype, factory->constructor_string(),
@@ -4128,14 +4233,14 @@ void Genesis::InitializeIteratorFunctions() {
         JSFunction::kSizeWithPrototype, 0, async_generator_function_prototype,
         Builtins::kAsyncGeneratorFunctionConstructor);
     async_generator_function_function->set_prototype_or_initial_map(
-        native_context->async_generator_function_map());
+        native_context->async_generator_function_map(), kReleaseStore);
     async_generator_function_function->shared().DontAdaptArguments();
     async_generator_function_function->shared().set_length(1);
     InstallWithIntrinsicDefaultProto(
         isolate, async_generator_function_function,
         Context::ASYNC_GENERATOR_FUNCTION_FUNCTION_INDEX);
 
-    JSObject::ForceSetPrototype(async_generator_function_function,
+    JSObject::ForceSetPrototype(isolate, async_generator_function_function,
                                 isolate->function_function());
 
     JSObject::AddProperty(
@@ -4151,7 +4256,7 @@ void Genesis::InitializeIteratorFunctions() {
     // Setup %SetIteratorPrototype%.
     Handle<JSObject> prototype =
         factory->NewJSObject(isolate->object_function(), AllocationType::kOld);
-    JSObject::ForceSetPrototype(prototype, iterator_prototype);
+    JSObject::ForceSetPrototype(isolate, prototype, iterator_prototype);
 
     InstallToStringTag(isolate, prototype, factory->SetIterator_string());
 
@@ -4184,7 +4289,7 @@ void Genesis::InitializeIteratorFunctions() {
     // Setup %MapIteratorPrototype%.
     Handle<JSObject> prototype =
         factory->NewJSObject(isolate->object_function(), AllocationType::kOld);
-    JSObject::ForceSetPrototype(prototype, iterator_prototype);
+    JSObject::ForceSetPrototype(isolate, prototype, iterator_prototype);
 
     InstallToStringTag(isolate, prototype, factory->MapIterator_string());
 
@@ -4229,11 +4334,11 @@ void Genesis::InitializeIteratorFunctions() {
         JSFunction::kSizeWithPrototype, 0, async_function_prototype,
         Builtins::kAsyncFunctionConstructor);
     async_function_constructor->set_prototype_or_initial_map(
-        native_context->async_function_map());
+        native_context->async_function_map(), kReleaseStore);
     async_function_constructor->shared().DontAdaptArguments();
     async_function_constructor->shared().set_length(1);
     native_context->set_async_function_constructor(*async_function_constructor);
-    JSObject::ForceSetPrototype(async_function_constructor,
+    JSObject::ForceSetPrototype(isolate, async_function_constructor,
                                 isolate->function_function());
 
     JSObject::AddProperty(
@@ -4325,6 +4430,7 @@ EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_top_level_await)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_import_assertions)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_private_brand_checks)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_class_static_blocks)
+EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_error_cause)
 
 #ifdef V8_INTL_SUPPORT
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_intl_best_fit_matcher)
@@ -4335,7 +4441,10 @@ EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_intl_dateformat_day_period)
 #undef EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE
 
 void Genesis::InitializeGlobal_harmony_sharedarraybuffer() {
-  if (!FLAG_harmony_sharedarraybuffer) return;
+  if (!FLAG_harmony_sharedarraybuffer ||
+      FLAG_enable_sharedarraybuffer_per_context) {
+    return;
+  }
 
   Handle<JSGlobalObject> global(native_context()->global_object(), isolate());
 
@@ -4353,75 +4462,8 @@ void Genesis::InitializeGlobal_harmony_atomics() {
   InstallToStringTag(isolate_, isolate()->atomics_object(), "Atomics");
 }
 
-void Genesis::InitializeGlobal_harmony_weak_refs() {
-  if (!FLAG_harmony_weak_refs) return;
-
-  Factory* factory = isolate()->factory();
-  Handle<JSGlobalObject> global(native_context()->global_object(), isolate());
-
-  {
-    // Create %FinalizationRegistry%
-    Handle<JSFunction> finalization_registry_fun = InstallFunction(
-        isolate(), global, factory->FinalizationRegistry_string(),
-        JS_FINALIZATION_REGISTRY_TYPE, JSFinalizationRegistry::kHeaderSize, 0,
-        factory->the_hole_value(), Builtins::kFinalizationRegistryConstructor);
-    InstallWithIntrinsicDefaultProto(
-        isolate(), finalization_registry_fun,
-        Context::JS_FINALIZATION_REGISTRY_FUNCTION_INDEX);
-
-    finalization_registry_fun->shared().DontAdaptArguments();
-    finalization_registry_fun->shared().set_length(1);
-
-    Handle<JSObject> finalization_registry_prototype(
-        JSObject::cast(finalization_registry_fun->instance_prototype()),
-        isolate());
-
-    InstallToStringTag(isolate(), finalization_registry_prototype,
-                       factory->FinalizationRegistry_string());
-
-    SimpleInstallFunction(isolate(), finalization_registry_prototype,
-                          "register", Builtins::kFinalizationRegistryRegister,
-                          2, false);
-
-    SimpleInstallFunction(isolate(), finalization_registry_prototype,
-                          "unregister",
-                          Builtins::kFinalizationRegistryUnregister, 1, false);
-
-    // The cleanupSome function is created but not exposed, as it is used
-    // internally by InvokeFinalizationRegistryCleanupFromTask.
-    //
-    // It is exposed by FLAG_harmony_weak_refs_with_cleanup_some.
-    Handle<JSFunction> cleanup_some_fun = SimpleCreateFunction(
-        isolate(), factory->InternalizeUtf8String("cleanupSome"),
-        Builtins::kFinalizationRegistryPrototypeCleanupSome, 0, false);
-    native_context()->set_finalization_registry_cleanup_some(*cleanup_some_fun);
-  }
-  {
-    // Create %WeakRef%
-    Handle<JSFunction> weak_ref_fun = InstallFunction(
-        isolate(), global, factory->WeakRef_string(), JS_WEAK_REF_TYPE,
-        JSWeakRef::kHeaderSize, 0, factory->the_hole_value(),
-        Builtins::kWeakRefConstructor);
-    InstallWithIntrinsicDefaultProto(isolate(), weak_ref_fun,
-                                     Context::JS_WEAK_REF_FUNCTION_INDEX);
-
-    weak_ref_fun->shared().DontAdaptArguments();
-    weak_ref_fun->shared().set_length(1);
-
-    Handle<JSObject> weak_ref_prototype(
-        JSObject::cast(weak_ref_fun->instance_prototype()), isolate());
-
-    InstallToStringTag(isolate(), weak_ref_prototype,
-                       factory->WeakRef_string());
-
-    SimpleInstallFunction(isolate(), weak_ref_prototype, "deref",
-                          Builtins::kWeakRefDeref, 0, true);
-  }
-}
-
 void Genesis::InitializeGlobal_harmony_weak_refs_with_cleanup_some() {
   if (!FLAG_harmony_weak_refs_with_cleanup_some) return;
-  DCHECK(FLAG_harmony_weak_refs);
 
   Handle<JSFunction> finalization_registry_fun =
       isolate()->js_finalization_registry_fun();
@@ -4519,6 +4561,45 @@ void Genesis::InitializeGlobal_harmony_relative_indexing_methods() {
   }
 }
 
+#ifdef V8_INTL_SUPPORT
+
+void Genesis::InitializeGlobal_harmony_intl_locale_info() {
+  if (!FLAG_harmony_intl_locale_info) return;
+  Handle<JSObject> prototype(
+      JSObject::cast(native_context()->intl_locale_function().prototype()),
+      isolate_);
+  SimpleInstallGetter(isolate(), prototype, factory()->calendars_string(),
+                      Builtins::kLocalePrototypeCalendars, true);
+  SimpleInstallGetter(isolate(), prototype, factory()->collations_string(),
+                      Builtins::kLocalePrototypeCollations, true);
+  SimpleInstallGetter(isolate(), prototype, factory()->hourCycles_string(),
+                      Builtins::kLocalePrototypeHourCycles, true);
+  SimpleInstallGetter(isolate(), prototype,
+                      factory()->numberingSystems_string(),
+                      Builtins::kLocalePrototypeNumberingSystems, true);
+  SimpleInstallGetter(isolate(), prototype, factory()->textInfo_string(),
+                      Builtins::kLocalePrototypeTextInfo, true);
+  SimpleInstallGetter(isolate(), prototype, factory()->timeZones_string(),
+                      Builtins::kLocalePrototypeTimeZones, true);
+  SimpleInstallGetter(isolate(), prototype, factory()->weekInfo_string(),
+                      Builtins::kLocalePrototypeWeekInfo, true);
+}
+
+#endif  // V8_INTL_SUPPORT
+
+void Genesis::InitializeGlobal_harmony_rab_gsab() {
+  if (!FLAG_harmony_rab_gsab) return;
+
+  Handle<JSGlobalObject> global(native_context()->global_object(), isolate());
+
+  JSObject::AddProperty(isolate_, global, "ResizableArrayBuffer",
+                        isolate()->resizable_array_buffer_fun(), DONT_ENUM);
+
+  JSObject::AddProperty(isolate_, global, "GrowableSharedArrayBuffer",
+                        isolate()->growable_shared_array_buffer_fun(),
+                        DONT_ENUM);
+}
+
 Handle<JSFunction> Genesis::CreateArrayBuffer(
     Handle<String> name, ArrayBufferKind array_buffer_kind) {
   // Create the %ArrayBufferPrototype%
@@ -4562,6 +4643,28 @@ Handle<JSFunction> Genesis::CreateArrayBuffer(
                             Builtins::kSharedArrayBufferPrototypeSlice, 2,
                             true);
       break;
+    case RESIZABLE_ARRAY_BUFFER:
+      SimpleInstallGetter(isolate(), prototype, factory()->byte_length_string(),
+                          Builtins::kResizableArrayBufferPrototypeGetByteLength,
+                          false);
+      SimpleInstallGetter(
+          isolate(), prototype, factory()->max_byte_length_string(),
+          Builtins::kResizableArrayBufferPrototypeGetMaxByteLength, false);
+      SimpleInstallFunction(isolate(), prototype, "resize",
+                            Builtins::kResizableArrayBufferPrototypeResize, 1,
+                            true);
+      break;
+    case GROWABLE_SHARED_ARRAY_BUFFER:
+      SimpleInstallGetter(
+          isolate(), prototype, factory()->byte_length_string(),
+          Builtins::kGrowableSharedArrayBufferPrototypeGetByteLength, true);
+      SimpleInstallGetter(
+          isolate(), prototype, factory()->max_byte_length_string(),
+          Builtins::kGrowableSharedArrayBufferPrototypeGetMaxByteLength, false);
+      SimpleInstallFunction(isolate(), prototype, "grow",
+                            Builtins::kGrowableSharedArrayBufferPrototypeGrow,
+                            1, true);
+      break;
   }
 
   return array_buffer_fun;
@@ -5097,7 +5200,7 @@ bool Genesis::ConfigureGlobalObjects(
     }
   }
 
-  JSObject::ForceSetPrototype(global_proxy, global_object);
+  JSObject::ForceSetPrototype(isolate(), global_proxy, global_object);
 
   native_context()->set_array_buffer_map(
       native_context()->array_buffer_fun().initial_map());
@@ -5262,7 +5365,7 @@ void Genesis::TransferObject(Handle<JSObject> from, Handle<JSObject> to) {
 
   // Transfer the prototype (new map is needed).
   Handle<HeapObject> proto(from->map().prototype(), isolate());
-  JSObject::ForceSetPrototype(to, proto);
+  JSObject::ForceSetPrototype(isolate(), to, proto);
 }
 
 Handle<Map> Genesis::CreateInitialMapForArraySubclass(int size,
@@ -5312,7 +5415,7 @@ Genesis::Genesis(
     v8::DeserializeEmbedderFieldsCallback embedder_fields_deserializer,
     v8::MicrotaskQueue* microtask_queue)
     : isolate_(isolate), active_(isolate->bootstrapper()) {
-  RuntimeCallTimerScope rcs_timer(isolate, RuntimeCallCounterId::kGenesis);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kGenesis);
   result_ = Handle<Context>::null();
   global_proxy_ = Handle<JSGlobalProxy>::null();
 
@@ -5495,7 +5598,7 @@ Genesis::Genesis(Isolate* isolate,
   global_proxy->set_native_context(ReadOnlyRoots(heap()).null_value());
 
   // Configure the hidden prototype chain of the global proxy.
-  JSObject::ForceSetPrototype(global_proxy, global_object);
+  JSObject::ForceSetPrototype(isolate, global_proxy, global_object);
   global_proxy->map().SetConstructor(*global_constructor);
 
   global_proxy_ = global_proxy;
diff --git a/chromium/v8/src/init/heap-symbols.h b/chromium/v8/src/init/heap-symbols.h
index 71eb0545965..4d0213e8d1f 100644
--- a/chromium/v8/src/init/heap-symbols.h
+++ b/chromium/v8/src/init/heap-symbols.h
@@ -12,10 +12,12 @@
   V(_, accounting_string, "accounting")                             \
   V(_, breakType_string, "breakType")                               \
   V(_, calendar_string, "calendar")                                 \
+  V(_, calendars_string, "calendars")                               \
   V(_, cardinal_string, "cardinal")                                 \
   V(_, caseFirst_string, "caseFirst")                               \
   V(_, compare_string, "compare")                                   \
   V(_, collation_string, "collation")                               \
+  V(_, collations_string, "collations")                             \
   V(_, compact_string, "compact")                                   \
   V(_, compactDisplay_string, "compactDisplay")                     \
   V(_, currency_string, "currency")                                 \
@@ -26,6 +28,7 @@
   V(_, day_string, "day")                                           \
   V(_, dayPeriod_string, "dayPeriod")                               \
   V(_, decimal_string, "decimal")                                   \
+  V(_, direction_string, "direction")                               \
   V(_, endRange_string, "endRange")                                 \
   V(_, engineering_string, "engineering")                           \
   V(_, era_string, "era")                                           \
@@ -35,6 +38,7 @@
   V(_, exponentSeparator_string, "exponentSeparator")               \
   V(_, fallback_string, "fallback")                                 \
   V(_, first_string, "first")                                       \
+  V(_, firstDay_string, "firstDay")                                 \
   V(_, format_string, "format")                                     \
   V(_, fraction_string, "fraction")                                 \
   V(_, fractionalSecond_string, "fractionalSecond")                 \
@@ -50,6 +54,7 @@
   V(_, hour_string, "hour")                                         \
   V(_, hour12_string, "hour12")                                     \
   V(_, hourCycle_string, "hourCycle")                               \
+  V(_, hourCycles_string, "hourCycles")                             \
   V(_, ideo_string, "ideo")                                         \
   V(_, ignorePunctuation_string, "ignorePunctuation")               \
   V(_, Invalid_Date_string, "Invalid Date")                         \
@@ -63,8 +68,10 @@
   V(_, locale_string, "locale")                                     \
   V(_, loose_string, "loose")                                       \
   V(_, lower_string, "lower")                                       \
+  V(_, ltr_string, "ltr")                                           \
   V(_, maximumFractionDigits_string, "maximumFractionDigits")       \
   V(_, maximumSignificantDigits_string, "maximumSignificantDigits") \
+  V(_, minimalDays_string, "minimalDays")                           \
   V(_, minimumFractionDigits_string, "minimumFractionDigits")       \
   V(_, minimumIntegerDigits_string, "minimumIntegerDigits")         \
   V(_, minimumSignificantDigits_string, "minimumSignificantDigits") \
@@ -78,6 +85,7 @@
   V(_, notation_string, "notation")                                 \
   V(_, normal_string, "normal")                                     \
   V(_, numberingSystem_string, "numberingSystem")                   \
+  V(_, numberingSystems_string, "numberingSystems")                 \
   V(_, numeric_string, "numeric")                                   \
   V(_, ordinal_string, "ordinal")                                   \
   V(_, percentSign_string, "percentSign")                           \
@@ -85,6 +93,7 @@
   V(_, quarter_string, "quarter")                                   \
   V(_, region_string, "region")                                     \
   V(_, relatedYear_string, "relatedYear")                           \
+  V(_, rtl_string, "rtl")                                           \
   V(_, scientific_string, "scientific")                             \
   V(_, second_string, "second")                                     \
   V(_, segment_string, "segment")                                   \
@@ -99,8 +108,10 @@
   V(_, strict_string, "strict")                                     \
   V(_, style_string, "style")                                       \
   V(_, term_string, "term")                                         \
+  V(_, textInfo_string, "textInfo")                                 \
   V(_, timeStyle_string, "timeStyle")                               \
   V(_, timeZone_string, "timeZone")                                 \
+  V(_, timeZones_string, "timeZones")                               \
   V(_, timeZoneName_string, "timeZoneName")                         \
   V(_, type_string, "type")                                         \
   V(_, unknown_string, "unknown")                                   \
@@ -111,228 +122,235 @@
   V(_, unit_string, "unit")                                         \
   V(_, unitDisplay_string, "unitDisplay")                           \
   V(_, weekday_string, "weekday")                                   \
+  V(_, weekendEnd_string, "weekendEnd")                             \
+  V(_, weekendStart_string, "weekendStart")                         \
+  V(_, weekInfo_string, "weekInfo")                                 \
   V(_, year_string, "year")                                         \
   V(_, yearName_string, "yearName")
 #else  // V8_INTL_SUPPORT
 #define INTERNALIZED_STRING_LIST_GENERATOR_INTL(V, _)
 #endif  // V8_INTL_SUPPORT
 
-#define INTERNALIZED_STRING_LIST_GENERATOR(V, _)                     \
-  INTERNALIZED_STRING_LIST_GENERATOR_INTL(V, _)                      \
-  V(_, add_string, "add")                                            \
-  V(_, AggregateError_string, "AggregateError")                      \
-  V(_, always_string, "always")                                      \
-  V(_, anonymous_function_string, "(anonymous function)")            \
-  V(_, anonymous_string, "anonymous")                                \
-  V(_, apply_string, "apply")                                        \
-  V(_, Arguments_string, "Arguments")                                \
-  V(_, arguments_string, "arguments")                                \
-  V(_, arguments_to_string, "[object Arguments]")                    \
-  V(_, Array_string, "Array")                                        \
-  V(_, array_to_string, "[object Array]")                            \
-  V(_, ArrayBuffer_string, "ArrayBuffer")                            \
-  V(_, ArrayIterator_string, "Array Iterator")                       \
-  V(_, as_string, "as")                                              \
-  V(_, assert_string, "assert")                                      \
-  V(_, async_string, "async")                                        \
-  V(_, auto_string, "auto")                                          \
-  V(_, await_string, "await")                                        \
-  V(_, BigInt_string, "BigInt")                                      \
-  V(_, bigint_string, "bigint")                                      \
-  V(_, BigInt64Array_string, "BigInt64Array")                        \
-  V(_, BigUint64Array_string, "BigUint64Array")                      \
-  V(_, bind_string, "bind")                                          \
-  V(_, Boolean_string, "Boolean")                                    \
-  V(_, boolean_string, "boolean")                                    \
-  V(_, boolean_to_string, "[object Boolean]")                        \
-  V(_, bound__string, "bound ")                                      \
-  V(_, buffer_string, "buffer")                                      \
-  V(_, byte_length_string, "byteLength")                             \
-  V(_, byte_offset_string, "byteOffset")                             \
-  V(_, CompileError_string, "CompileError")                          \
-  V(_, callee_string, "callee")                                      \
-  V(_, caller_string, "caller")                                      \
-  V(_, character_string, "character")                                \
-  V(_, closure_string, "(closure)")                                  \
-  V(_, code_string, "code")                                          \
-  V(_, column_string, "column")                                      \
-  V(_, computed_string, "<computed>")                                \
-  V(_, configurable_string, "configurable")                          \
-  V(_, conjunction_string, "conjunction")                            \
-  V(_, construct_string, "construct")                                \
-  V(_, constructor_string, "constructor")                            \
-  V(_, current_string, "current")                                    \
-  V(_, Date_string, "Date")                                          \
-  V(_, date_to_string, "[object Date]")                              \
-  V(_, default_string, "default")                                    \
-  V(_, defineProperty_string, "defineProperty")                      \
-  V(_, deleteProperty_string, "deleteProperty")                      \
-  V(_, disjunction_string, "disjunction")                            \
-  V(_, done_string, "done")                                          \
-  V(_, dot_brand_string, ".brand")                                   \
-  V(_, dot_catch_string, ".catch")                                   \
-  V(_, dot_default_string, ".default")                               \
-  V(_, dot_for_string, ".for")                                       \
-  V(_, dot_generator_object_string, ".generator_object")             \
-  V(_, dot_home_object_string, ".home_object")                       \
-  V(_, dot_result_string, ".result")                                 \
-  V(_, dot_repl_result_string, ".repl_result")                       \
-  V(_, dot_static_home_object_string, "._static_home_object")        \
-  V(_, dot_string, ".")                                              \
-  V(_, dot_switch_tag_string, ".switch_tag")                         \
-  V(_, dotAll_string, "dotAll")                                      \
-  V(_, enumerable_string, "enumerable")                              \
-  V(_, element_string, "element")                                    \
-  V(_, Error_string, "Error")                                        \
-  V(_, errors_string, "errors")                                      \
-  V(_, error_to_string, "[object Error]")                            \
-  V(_, eval_string, "eval")                                          \
-  V(_, EvalError_string, "EvalError")                                \
-  V(_, exec_string, "exec")                                          \
-  V(_, false_string, "false")                                        \
-  V(_, FinalizationRegistry_string, "FinalizationRegistry")          \
-  V(_, flags_string, "flags")                                        \
-  V(_, Float32Array_string, "Float32Array")                          \
-  V(_, Float64Array_string, "Float64Array")                          \
-  V(_, from_string, "from")                                          \
-  V(_, Function_string, "Function")                                  \
-  V(_, function_native_code_string, "function () { [native code] }") \
-  V(_, function_string, "function")                                  \
-  V(_, function_to_string, "[object Function]")                      \
-  V(_, Generator_string, "Generator")                                \
-  V(_, get_space_string, "get ")                                     \
-  V(_, get_string, "get")                                            \
-  V(_, getOwnPropertyDescriptor_string, "getOwnPropertyDescriptor")  \
-  V(_, getPrototypeOf_string, "getPrototypeOf")                      \
-  V(_, global_string, "global")                                      \
-  V(_, globalThis_string, "globalThis")                              \
-  V(_, groups_string, "groups")                                      \
-  V(_, has_string, "has")                                            \
-  V(_, has_indices_string, "hasIndices")                             \
-  V(_, ignoreCase_string, "ignoreCase")                              \
-  V(_, illegal_access_string, "illegal access")                      \
-  V(_, illegal_argument_string, "illegal argument")                  \
-  V(_, index_string, "index")                                        \
-  V(_, indices_string, "indices")                                    \
-  V(_, Infinity_string, "Infinity")                                  \
-  V(_, infinity_string, "infinity")                                  \
-  V(_, input_string, "input")                                        \
-  V(_, Int16Array_string, "Int16Array")                              \
-  V(_, Int32Array_string, "Int32Array")                              \
-  V(_, Int8Array_string, "Int8Array")                                \
-  V(_, isExtensible_string, "isExtensible")                          \
-  V(_, jsMemoryEstimate_string, "jsMemoryEstimate")                  \
-  V(_, jsMemoryRange_string, "jsMemoryRange")                        \
-  V(_, keys_string, "keys")                                          \
-  V(_, lastIndex_string, "lastIndex")                                \
-  V(_, length_string, "length")                                      \
-  V(_, let_string, "let")                                            \
-  V(_, line_string, "line")                                          \
-  V(_, linear_string, "linear")                                      \
-  V(_, LinkError_string, "LinkError")                                \
-  V(_, long_string, "long")                                          \
-  V(_, Map_string, "Map")                                            \
-  V(_, MapIterator_string, "Map Iterator")                           \
-  V(_, medium_string, "medium")                                      \
-  V(_, message_string, "message")                                    \
-  V(_, meta_string, "meta")                                          \
-  V(_, minus_Infinity_string, "-Infinity")                           \
-  V(_, Module_string, "Module")                                      \
-  V(_, multiline_string, "multiline")                                \
-  V(_, name_string, "name")                                          \
-  V(_, NaN_string, "NaN")                                            \
-  V(_, narrow_string, "narrow")                                      \
-  V(_, native_string, "native")                                      \
-  V(_, new_target_string, ".new.target")                             \
-  V(_, next_string, "next")                                          \
-  V(_, NFC_string, "NFC")                                            \
-  V(_, NFD_string, "NFD")                                            \
-  V(_, NFKC_string, "NFKC")                                          \
-  V(_, NFKD_string, "NFKD")                                          \
-  V(_, not_equal_string, "not-equal")                                \
-  V(_, null_string, "null")                                          \
-  V(_, null_to_string, "[object Null]")                              \
-  V(_, Number_string, "Number")                                      \
-  V(_, number_string, "number")                                      \
-  V(_, number_to_string, "[object Number]")                          \
-  V(_, Object_string, "Object")                                      \
-  V(_, object_string, "object")                                      \
-  V(_, object_to_string, "[object Object]")                          \
-  V(_, of_string, "of")                                              \
-  V(_, ok_string, "ok")                                              \
-  V(_, one_string, "1")                                              \
-  V(_, other_string, "other")                                        \
-  V(_, ownKeys_string, "ownKeys")                                    \
-  V(_, percent_string, "percent")                                    \
-  V(_, position_string, "position")                                  \
-  V(_, preventExtensions_string, "preventExtensions")                \
-  V(_, private_constructor_string, "#constructor")                   \
-  V(_, Promise_string, "Promise")                                    \
-  V(_, proto_string, "__proto__")                                    \
-  V(_, prototype_string, "prototype")                                \
-  V(_, proxy_string, "proxy")                                        \
-  V(_, Proxy_string, "Proxy")                                        \
-  V(_, query_colon_string, "(?:)")                                   \
-  V(_, RangeError_string, "RangeError")                              \
-  V(_, raw_string, "raw")                                            \
-  V(_, ReferenceError_string, "ReferenceError")                      \
-  V(_, ReflectGet_string, "Reflect.get")                             \
-  V(_, ReflectHas_string, "Reflect.has")                             \
-  V(_, RegExp_string, "RegExp")                                      \
-  V(_, regexp_to_string, "[object RegExp]")                          \
-  V(_, resolve_string, "resolve")                                    \
-  V(_, return_string, "return")                                      \
-  V(_, revoke_string, "revoke")                                      \
-  V(_, RuntimeError_string, "RuntimeError")                          \
-  V(_, Script_string, "Script")                                      \
-  V(_, script_string, "script")                                      \
-  V(_, short_string, "short")                                        \
-  V(_, Set_string, "Set")                                            \
-  V(_, sentence_string, "sentence")                                  \
-  V(_, set_space_string, "set ")                                     \
-  V(_, set_string, "set")                                            \
-  V(_, SetIterator_string, "Set Iterator")                           \
-  V(_, setPrototypeOf_string, "setPrototypeOf")                      \
-  V(_, SharedArrayBuffer_string, "SharedArrayBuffer")                \
-  V(_, source_string, "source")                                      \
-  V(_, sourceText_string, "sourceText")                              \
-  V(_, stack_string, "stack")                                        \
-  V(_, stackTraceLimit_string, "stackTraceLimit")                    \
-  V(_, sticky_string, "sticky")                                      \
-  V(_, String_string, "String")                                      \
-  V(_, string_string, "string")                                      \
-  V(_, string_to_string, "[object String]")                          \
-  V(_, symbol_species_string, "[Symbol.species]")                    \
-  V(_, Symbol_string, "Symbol")                                      \
-  V(_, symbol_string, "symbol")                                      \
-  V(_, SyntaxError_string, "SyntaxError")                            \
-  V(_, target_string, "target")                                      \
-  V(_, then_string, "then")                                          \
-  V(_, this_function_string, ".this_function")                       \
-  V(_, this_string, "this")                                          \
-  V(_, throw_string, "throw")                                        \
-  V(_, timed_out_string, "timed-out")                                \
-  V(_, toJSON_string, "toJSON")                                      \
-  V(_, toString_string, "toString")                                  \
-  V(_, true_string, "true")                                          \
-  V(_, total_string, "total")                                        \
-  V(_, TypeError_string, "TypeError")                                \
-  V(_, Uint16Array_string, "Uint16Array")                            \
-  V(_, Uint32Array_string, "Uint32Array")                            \
-  V(_, Uint8Array_string, "Uint8Array")                              \
-  V(_, Uint8ClampedArray_string, "Uint8ClampedArray")                \
-  V(_, undefined_string, "undefined")                                \
-  V(_, undefined_to_string, "[object Undefined]")                    \
-  V(_, unicode_string, "unicode")                                    \
-  V(_, URIError_string, "URIError")                                  \
-  V(_, value_string, "value")                                        \
-  V(_, valueOf_string, "valueOf")                                    \
-  V(_, WeakMap_string, "WeakMap")                                    \
-  V(_, WeakRef_string, "WeakRef")                                    \
-  V(_, WeakSet_string, "WeakSet")                                    \
-  V(_, week_string, "week")                                          \
-  V(_, word_string, "word")                                          \
-  V(_, writable_string, "writable")                                  \
+#define INTERNALIZED_STRING_LIST_GENERATOR(V, _)                      \
+  INTERNALIZED_STRING_LIST_GENERATOR_INTL(V, _)                       \
+  V(_, add_string, "add")                                             \
+  V(_, AggregateError_string, "AggregateError")                       \
+  V(_, always_string, "always")                                       \
+  V(_, anonymous_function_string, "(anonymous function)")             \
+  V(_, anonymous_string, "anonymous")                                 \
+  V(_, apply_string, "apply")                                         \
+  V(_, Arguments_string, "Arguments")                                 \
+  V(_, arguments_string, "arguments")                                 \
+  V(_, arguments_to_string, "[object Arguments]")                     \
+  V(_, Array_string, "Array")                                         \
+  V(_, array_to_string, "[object Array]")                             \
+  V(_, ArrayBuffer_string, "ArrayBuffer")                             \
+  V(_, ArrayIterator_string, "Array Iterator")                        \
+  V(_, as_string, "as")                                               \
+  V(_, assert_string, "assert")                                       \
+  V(_, async_string, "async")                                         \
+  V(_, auto_string, "auto")                                           \
+  V(_, await_string, "await")                                         \
+  V(_, BigInt_string, "BigInt")                                       \
+  V(_, bigint_string, "bigint")                                       \
+  V(_, BigInt64Array_string, "BigInt64Array")                         \
+  V(_, BigUint64Array_string, "BigUint64Array")                       \
+  V(_, bind_string, "bind")                                           \
+  V(_, Boolean_string, "Boolean")                                     \
+  V(_, boolean_string, "boolean")                                     \
+  V(_, boolean_to_string, "[object Boolean]")                         \
+  V(_, bound__string, "bound ")                                       \
+  V(_, buffer_string, "buffer")                                       \
+  V(_, byte_length_string, "byteLength")                              \
+  V(_, byte_offset_string, "byteOffset")                              \
+  V(_, CompileError_string, "CompileError")                           \
+  V(_, callee_string, "callee")                                       \
+  V(_, caller_string, "caller")                                       \
+  V(_, cause_string, "cause")                                         \
+  V(_, character_string, "character")                                 \
+  V(_, closure_string, "(closure)")                                   \
+  V(_, code_string, "code")                                           \
+  V(_, column_string, "column")                                       \
+  V(_, computed_string, "<computed>")                                 \
+  V(_, configurable_string, "configurable")                           \
+  V(_, conjunction_string, "conjunction")                             \
+  V(_, construct_string, "construct")                                 \
+  V(_, constructor_string, "constructor")                             \
+  V(_, current_string, "current")                                     \
+  V(_, Date_string, "Date")                                           \
+  V(_, date_to_string, "[object Date]")                               \
+  V(_, default_string, "default")                                     \
+  V(_, defineProperty_string, "defineProperty")                       \
+  V(_, deleteProperty_string, "deleteProperty")                       \
+  V(_, disjunction_string, "disjunction")                             \
+  V(_, done_string, "done")                                           \
+  V(_, dot_brand_string, ".brand")                                    \
+  V(_, dot_catch_string, ".catch")                                    \
+  V(_, dot_default_string, ".default")                                \
+  V(_, dot_for_string, ".for")                                        \
+  V(_, dot_generator_object_string, ".generator_object")              \
+  V(_, dot_home_object_string, ".home_object")                        \
+  V(_, dot_result_string, ".result")                                  \
+  V(_, dot_repl_result_string, ".repl_result")                        \
+  V(_, dot_static_home_object_string, "._static_home_object")         \
+  V(_, dot_string, ".")                                               \
+  V(_, dot_switch_tag_string, ".switch_tag")                          \
+  V(_, dotAll_string, "dotAll")                                       \
+  V(_, enumerable_string, "enumerable")                               \
+  V(_, element_string, "element")                                     \
+  V(_, Error_string, "Error")                                         \
+  V(_, errors_string, "errors")                                       \
+  V(_, error_to_string, "[object Error]")                             \
+  V(_, eval_string, "eval")                                           \
+  V(_, EvalError_string, "EvalError")                                 \
+  V(_, exec_string, "exec")                                           \
+  V(_, false_string, "false")                                         \
+  V(_, FinalizationRegistry_string, "FinalizationRegistry")           \
+  V(_, flags_string, "flags")                                         \
+  V(_, Float32Array_string, "Float32Array")                           \
+  V(_, Float64Array_string, "Float64Array")                           \
+  V(_, from_string, "from")                                           \
+  V(_, Function_string, "Function")                                   \
+  V(_, function_native_code_string, "function () { [native code] }")  \
+  V(_, function_string, "function")                                   \
+  V(_, function_to_string, "[object Function]")                       \
+  V(_, Generator_string, "Generator")                                 \
+  V(_, get_space_string, "get ")                                      \
+  V(_, get_string, "get")                                             \
+  V(_, getOwnPropertyDescriptor_string, "getOwnPropertyDescriptor")   \
+  V(_, getPrototypeOf_string, "getPrototypeOf")                       \
+  V(_, global_string, "global")                                       \
+  V(_, globalThis_string, "globalThis")                               \
+  V(_, groups_string, "groups")                                       \
+  V(_, GrowableSharedArrayBuffer_string, "GrowableSharedArrayBuffer") \
+  V(_, has_string, "has")                                             \
+  V(_, has_indices_string, "hasIndices")                              \
+  V(_, ignoreCase_string, "ignoreCase")                               \
+  V(_, illegal_access_string, "illegal access")                       \
+  V(_, illegal_argument_string, "illegal argument")                   \
+  V(_, index_string, "index")                                         \
+  V(_, indices_string, "indices")                                     \
+  V(_, Infinity_string, "Infinity")                                   \
+  V(_, infinity_string, "infinity")                                   \
+  V(_, input_string, "input")                                         \
+  V(_, Int16Array_string, "Int16Array")                               \
+  V(_, Int32Array_string, "Int32Array")                               \
+  V(_, Int8Array_string, "Int8Array")                                 \
+  V(_, isExtensible_string, "isExtensible")                           \
+  V(_, jsMemoryEstimate_string, "jsMemoryEstimate")                   \
+  V(_, jsMemoryRange_string, "jsMemoryRange")                         \
+  V(_, keys_string, "keys")                                           \
+  V(_, lastIndex_string, "lastIndex")                                 \
+  V(_, length_string, "length")                                       \
+  V(_, let_string, "let")                                             \
+  V(_, line_string, "line")                                           \
+  V(_, linear_string, "linear")                                       \
+  V(_, LinkError_string, "LinkError")                                 \
+  V(_, long_string, "long")                                           \
+  V(_, Map_string, "Map")                                             \
+  V(_, MapIterator_string, "Map Iterator")                            \
+  V(_, max_byte_length_string, "maxByteLength")                       \
+  V(_, medium_string, "medium")                                       \
+  V(_, message_string, "message")                                     \
+  V(_, meta_string, "meta")                                           \
+  V(_, minus_Infinity_string, "-Infinity")                            \
+  V(_, Module_string, "Module")                                       \
+  V(_, multiline_string, "multiline")                                 \
+  V(_, name_string, "name")                                           \
+  V(_, NaN_string, "NaN")                                             \
+  V(_, narrow_string, "narrow")                                       \
+  V(_, native_string, "native")                                       \
+  V(_, new_target_string, ".new.target")                              \
+  V(_, next_string, "next")                                           \
+  V(_, NFC_string, "NFC")                                             \
+  V(_, NFD_string, "NFD")                                             \
+  V(_, NFKC_string, "NFKC")                                           \
+  V(_, NFKD_string, "NFKD")                                           \
+  V(_, not_equal_string, "not-equal")                                 \
+  V(_, null_string, "null")                                           \
+  V(_, null_to_string, "[object Null]")                               \
+  V(_, Number_string, "Number")                                       \
+  V(_, number_string, "number")                                       \
+  V(_, number_to_string, "[object Number]")                           \
+  V(_, Object_string, "Object")                                       \
+  V(_, object_string, "object")                                       \
+  V(_, object_to_string, "[object Object]")                           \
+  V(_, of_string, "of")                                               \
+  V(_, ok_string, "ok")                                               \
+  V(_, one_string, "1")                                               \
+  V(_, other_string, "other")                                         \
+  V(_, ownKeys_string, "ownKeys")                                     \
+  V(_, percent_string, "percent")                                     \
+  V(_, position_string, "position")                                   \
+  V(_, preventExtensions_string, "preventExtensions")                 \
+  V(_, private_constructor_string, "#constructor")                    \
+  V(_, Promise_string, "Promise")                                     \
+  V(_, proto_string, "__proto__")                                     \
+  V(_, prototype_string, "prototype")                                 \
+  V(_, proxy_string, "proxy")                                         \
+  V(_, Proxy_string, "Proxy")                                         \
+  V(_, query_colon_string, "(?:)")                                    \
+  V(_, RangeError_string, "RangeError")                               \
+  V(_, raw_string, "raw")                                             \
+  V(_, ReferenceError_string, "ReferenceError")                       \
+  V(_, ReflectGet_string, "Reflect.get")                              \
+  V(_, ReflectHas_string, "Reflect.has")                              \
+  V(_, RegExp_string, "RegExp")                                       \
+  V(_, regexp_to_string, "[object RegExp]")                           \
+  V(_, ResizableArrayBuffer_string, "ResizableArrayBuffer")           \
+  V(_, resolve_string, "resolve")                                     \
+  V(_, return_string, "return")                                       \
+  V(_, revoke_string, "revoke")                                       \
+  V(_, RuntimeError_string, "RuntimeError")                           \
+  V(_, Script_string, "Script")                                       \
+  V(_, script_string, "script")                                       \
+  V(_, short_string, "short")                                         \
+  V(_, Set_string, "Set")                                             \
+  V(_, sentence_string, "sentence")                                   \
+  V(_, set_space_string, "set ")                                      \
+  V(_, set_string, "set")                                             \
+  V(_, SetIterator_string, "Set Iterator")                            \
+  V(_, setPrototypeOf_string, "setPrototypeOf")                       \
+  V(_, SharedArrayBuffer_string, "SharedArrayBuffer")                 \
+  V(_, source_string, "source")                                       \
+  V(_, sourceText_string, "sourceText")                               \
+  V(_, stack_string, "stack")                                         \
+  V(_, stackTraceLimit_string, "stackTraceLimit")                     \
+  V(_, sticky_string, "sticky")                                       \
+  V(_, String_string, "String")                                       \
+  V(_, string_string, "string")                                       \
+  V(_, string_to_string, "[object String]")                           \
+  V(_, symbol_species_string, "[Symbol.species]")                     \
+  V(_, Symbol_string, "Symbol")                                       \
+  V(_, symbol_string, "symbol")                                       \
+  V(_, SyntaxError_string, "SyntaxError")                             \
+  V(_, target_string, "target")                                       \
+  V(_, then_string, "then")                                           \
+  V(_, this_function_string, ".this_function")                        \
+  V(_, this_string, "this")                                           \
+  V(_, throw_string, "throw")                                         \
+  V(_, timed_out_string, "timed-out")                                 \
+  V(_, toJSON_string, "toJSON")                                       \
+  V(_, toString_string, "toString")                                   \
+  V(_, true_string, "true")                                           \
+  V(_, total_string, "total")                                         \
+  V(_, TypeError_string, "TypeError")                                 \
+  V(_, Uint16Array_string, "Uint16Array")                             \
+  V(_, Uint32Array_string, "Uint32Array")                             \
+  V(_, Uint8Array_string, "Uint8Array")                               \
+  V(_, Uint8ClampedArray_string, "Uint8ClampedArray")                 \
+  V(_, undefined_string, "undefined")                                 \
+  V(_, undefined_to_string, "[object Undefined]")                     \
+  V(_, unicode_string, "unicode")                                     \
+  V(_, URIError_string, "URIError")                                   \
+  V(_, value_string, "value")                                         \
+  V(_, valueOf_string, "valueOf")                                     \
+  V(_, WeakMap_string, "WeakMap")                                     \
+  V(_, WeakRef_string, "WeakRef")                                     \
+  V(_, WeakSet_string, "WeakSet")                                     \
+  V(_, week_string, "week")                                           \
+  V(_, word_string, "word")                                           \
+  V(_, writable_string, "writable")                                   \
   V(_, zero_string, "0")
 
 #define PRIVATE_SYMBOL_LIST_GENERATOR(V, _)    \
@@ -349,6 +367,7 @@
   V(_, error_start_pos_symbol)                 \
   V(_, frozen_symbol)                          \
   V(_, interpreter_trampoline_symbol)          \
+  V(_, mega_dom_symbol)                        \
   V(_, megamorphic_symbol)                     \
   V(_, native_context_index_symbol)            \
   V(_, nonextensible_symbol)                   \
diff --git a/chromium/v8/src/init/isolate-allocator.cc b/chromium/v8/src/init/isolate-allocator.cc
index 5db27d288b1..a479f1ab945 100644
--- a/chromium/v8/src/init/isolate-allocator.cc
+++ b/chromium/v8/src/init/isolate-allocator.cc
@@ -3,39 +3,18 @@
 // found in the LICENSE file.
 
 #include "src/init/isolate-allocator.h"
+
 #include "src/base/bounded-page-allocator.h"
 #include "src/common/ptr-compr.h"
 #include "src/execution/isolate.h"
+#include "src/heap/code-range.h"
 #include "src/utils/memcopy.h"
 #include "src/utils/utils.h"
 
 namespace v8 {
 namespace internal {
 
-IsolateAllocator::IsolateAllocator() {
 #ifdef V8_COMPRESS_POINTERS
-  Address heap_reservation_address = InitReservation();
-  CommitPagesForIsolate(heap_reservation_address);
-#else
-  // Allocate Isolate in C++ heap.
-  page_allocator_ = GetPlatformPageAllocator();
-  isolate_memory_ = ::operator new(sizeof(Isolate));
-  DCHECK(!reservation_.IsReserved());
-#endif  // V8_COMPRESS_POINTERS
-}
-
-IsolateAllocator::~IsolateAllocator() {
-  if (reservation_.IsReserved()) {
-    // The actual memory will be freed when the |reservation_| will die.
-    return;
-  }
-
-  // The memory was allocated in C++ heap.
-  ::operator delete(isolate_memory_);
-}
-
-#ifdef V8_COMPRESS_POINTERS
-
 namespace {
 
 // "IsolateRootBiasPage" is an optional region before the 4Gb aligned
@@ -50,109 +29,125 @@ inline size_t GetIsolateRootBiasPageSize(
 
 }  // namespace
 
-Address IsolateAllocator::InitReservation() {
-  v8::PageAllocator* platform_page_allocator = GetPlatformPageAllocator();
+struct PtrComprCageReservationParams
+    : public VirtualMemoryCage::ReservationParams {
+  PtrComprCageReservationParams() {
+    page_allocator = GetPlatformPageAllocator();
+
+    // This is only used when there is a per-Isolate cage, in which case the
+    // Isolate is allocated within the cage, and the Isolate root is also the
+    // cage base.
+    const size_t kIsolateRootBiasPageSize =
+        COMPRESS_POINTERS_IN_ISOLATE_CAGE_BOOL
+            ? GetIsolateRootBiasPageSize(page_allocator)
+            : 0;
+    reservation_size = kPtrComprCageReservationSize + kIsolateRootBiasPageSize;
+    base_alignment = kPtrComprCageBaseAlignment;
+    base_bias_size = kIsolateRootBiasPageSize;
+
+    // Simplify BoundedPageAllocator's life by configuring it to use same page
+    // size as the Heap will use (MemoryChunk::kPageSize).
+    page_size =
+        RoundUp(size_t{1} << kPageSizeBits, page_allocator->AllocatePageSize());
+    requested_start_hint =
+        reinterpret_cast<Address>(page_allocator->GetRandomMmapAddr());
+  }
+};
+#endif  // V8_COMPRESS_POINTERS
 
-  const size_t kIsolateRootBiasPageSize =
-      GetIsolateRootBiasPageSize(platform_page_allocator);
-
-  // Reserve a |4Gb + kIsolateRootBiasPageSize| region such as that the
-  // resevation address plus |kIsolateRootBiasPageSize| is 4Gb aligned.
-  const size_t reservation_size =
-      kPtrComprCageReservationSize + kIsolateRootBiasPageSize;
-  const size_t base_alignment = kPtrComprCageBaseAlignment;
-
-  const int kMaxAttempts = 4;
-  for (int attempt = 0; attempt < kMaxAttempts; ++attempt) {
-    Address hint = RoundDown(reinterpret_cast<Address>(
-                                 platform_page_allocator->GetRandomMmapAddr()),
-                             base_alignment) -
-                   kIsolateRootBiasPageSize;
-
-    // Within this reservation there will be a sub-region with proper alignment.
-    VirtualMemory padded_reservation(platform_page_allocator,
-                                     reservation_size * 2,
-                                     reinterpret_cast<void*>(hint));
-    if (!padded_reservation.IsReserved()) break;
-
-    // Find properly aligned sub-region inside the reservation.
-    Address address =
-        RoundUp(padded_reservation.address() + kIsolateRootBiasPageSize,
-                base_alignment) -
-        kIsolateRootBiasPageSize;
-    CHECK(padded_reservation.InVM(address, reservation_size));
-
-#if defined(V8_OS_FUCHSIA)
-    // Fuchsia does not respect given hints so as a workaround we will use
-    // overreserved address space region instead of trying to re-reserve
-    // a subregion.
-    bool overreserve = true;
-#else
-    // For the last attempt use the overreserved region to avoid an OOM crash.
-    // This case can happen if there are many isolates being created in
-    // parallel that race for reserving the regions.
-    bool overreserve = (attempt == kMaxAttempts - 1);
+#ifdef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
+namespace {
+DEFINE_LAZY_LEAKY_OBJECT_GETTER(VirtualMemoryCage, GetProcessWidePtrComprCage)
+}  // anonymous namespace
+
+// static
+void IsolateAllocator::FreeProcessWidePtrComprCageForTesting() {
+  if (std::shared_ptr<CodeRange> code_range =
+          CodeRange::GetProcessWideCodeRange()) {
+    code_range->Free();
+  }
+  GetProcessWidePtrComprCage()->Free();
+}
+#endif  // V8_COMPRESS_POINTERS_IN_SHARED_CAGE
+
+// static
+void IsolateAllocator::InitializeOncePerProcess() {
+#ifdef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
+  PtrComprCageReservationParams params;
+  if (!GetProcessWidePtrComprCage()->InitReservation(params)) {
+    V8::FatalProcessOutOfMemory(
+        nullptr,
+        "Failed to reserve virtual memory for process-wide V8 "
+        "pointer compression cage");
+  }
 #endif
+}
 
-    if (overreserve) {
-      if (padded_reservation.InVM(address, reservation_size)) {
-        reservation_ = std::move(padded_reservation);
-        return address;
-      }
-    } else {
-      // Now free the padded reservation and immediately try to reserve an exact
-      // region at aligned address. We have to do this dancing because the
-      // reservation address requirement is more complex than just a certain
-      // alignment and not all operating systems support freeing parts of
-      // reserved address space regions.
-      padded_reservation.Free();
-
-      VirtualMemory reservation(platform_page_allocator, reservation_size,
-                                reinterpret_cast<void*>(address));
-      if (!reservation.IsReserved()) break;
-
-      // The reservation could still be somewhere else but we can accept it
-      // if it has the required alignment.
-      Address address =
-          RoundUp(reservation.address() + kIsolateRootBiasPageSize,
-                  base_alignment) -
-          kIsolateRootBiasPageSize;
-
-      if (reservation.address() == address) {
-        reservation_ = std::move(reservation);
-        CHECK_EQ(reservation_.size(), reservation_size);
-        return address;
-      }
-    }
+IsolateAllocator::IsolateAllocator() {
+#if defined(V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE)
+  PtrComprCageReservationParams params;
+  if (!isolate_ptr_compr_cage_.InitReservation(params)) {
+    V8::FatalProcessOutOfMemory(
+        nullptr,
+        "Failed to reserve memory for Isolate V8 pointer compression cage");
   }
-  V8::FatalProcessOutOfMemory(nullptr,
-                              "Failed to reserve memory for new V8 Isolate");
-  return kNullAddress;
+  page_allocator_ = isolate_ptr_compr_cage_.page_allocator();
+  CommitPagesForIsolate();
+#elif defined(V8_COMPRESS_POINTERS_IN_SHARED_CAGE)
+  // Allocate Isolate in C++ heap when sharing a cage.
+  CHECK(GetProcessWidePtrComprCage()->IsReserved());
+  page_allocator_ = GetProcessWidePtrComprCage()->page_allocator();
+  isolate_memory_ = ::operator new(sizeof(Isolate));
+#else
+  // Allocate Isolate in C++ heap.
+  page_allocator_ = GetPlatformPageAllocator();
+  isolate_memory_ = ::operator new(sizeof(Isolate));
+#endif  // V8_COMPRESS_POINTERS
+
+  CHECK_NOT_NULL(page_allocator_);
 }
 
-void IsolateAllocator::CommitPagesForIsolate(Address heap_reservation_address) {
-  v8::PageAllocator* platform_page_allocator = GetPlatformPageAllocator();
+IsolateAllocator::~IsolateAllocator() {
+#ifdef V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE
+  if (isolate_ptr_compr_cage_.reservation()->IsReserved()) {
+    // The actual memory will be freed when the |isolate_ptr_compr_cage_| will
+    // die.
+    return;
+  }
+#endif
 
-  const size_t kIsolateRootBiasPageSize =
-      GetIsolateRootBiasPageSize(platform_page_allocator);
+  // The memory was allocated in C++ heap.
+  ::operator delete(isolate_memory_);
+}
 
-  Address isolate_root = heap_reservation_address + kIsolateRootBiasPageSize;
-  CHECK(IsAligned(isolate_root, kPtrComprCageBaseAlignment));
+VirtualMemoryCage* IsolateAllocator::GetPtrComprCage() {
+#if defined V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE
+  return &isolate_ptr_compr_cage_;
+#elif defined V8_COMPRESS_POINTERS_IN_SHARED_CAGE
+  return GetProcessWidePtrComprCage();
+#else
+  return nullptr;
+#endif
+}
 
-  CHECK(reservation_.InVM(
-      heap_reservation_address,
-      kPtrComprCageReservationSize + kIsolateRootBiasPageSize));
+const VirtualMemoryCage* IsolateAllocator::GetPtrComprCage() const {
+  return const_cast<IsolateAllocator*>(this)->GetPtrComprCage();
+}
 
-  // Simplify BoundedPageAllocator's life by configuring it to use same page
-  // size as the Heap will use (MemoryChunk::kPageSize).
-  size_t page_size = RoundUp(size_t{1} << kPageSizeBits,
-                             platform_page_allocator->AllocatePageSize());
+#ifdef V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE
+void IsolateAllocator::CommitPagesForIsolate() {
+  v8::PageAllocator* platform_page_allocator = GetPlatformPageAllocator();
 
-  page_allocator_instance_ = std::make_unique<base::BoundedPageAllocator>(
-      platform_page_allocator, isolate_root, kPtrComprCageReservationSize,
-      page_size);
-  page_allocator_ = page_allocator_instance_.get();
+  CHECK(isolate_ptr_compr_cage_.IsReserved());
+  Address isolate_root = isolate_ptr_compr_cage_.base();
+  CHECK(IsAligned(isolate_root, kPtrComprCageBaseAlignment));
+  CHECK_GE(isolate_ptr_compr_cage_.reservation()->size(),
+           kPtrComprCageReservationSize +
+               GetIsolateRootBiasPageSize(platform_page_allocator));
+  CHECK(isolate_ptr_compr_cage_.reservation()->InVM(
+      isolate_root, kPtrComprCageReservationSize));
 
+  size_t page_size = page_allocator_->AllocatePageSize();
   Address isolate_address = isolate_root - Isolate::isolate_root_bias();
   Address isolate_end = isolate_address + sizeof(Isolate);
 
@@ -162,7 +157,7 @@ void IsolateAllocator::CommitPagesForIsolate(Address heap_reservation_address) {
     size_t reserved_region_size =
         RoundUp(isolate_end, page_size) - reserved_region_address;
 
-    CHECK(page_allocator_instance_->AllocatePagesAt(
+    CHECK(isolate_ptr_compr_cage_.page_allocator()->AllocatePagesAt(
         reserved_region_address, reserved_region_size,
         PageAllocator::Permission::kNoAccess));
   }
@@ -175,11 +170,12 @@ void IsolateAllocator::CommitPagesForIsolate(Address heap_reservation_address) {
     size_t committed_region_size =
         RoundUp(isolate_end, commit_page_size) - committed_region_address;
 
-    // We are using |reservation_| directly here because |page_allocator_| has
-    // bigger commit page size than we actually need.
-    CHECK(reservation_.SetPermissions(committed_region_address,
-                                      committed_region_size,
-                                      PageAllocator::kReadWrite));
+    // We are using |isolate_ptr_compr_cage_.reservation()| directly here
+    // because |page_allocator_| has bigger commit page size than we actually
+    // need.
+    CHECK(isolate_ptr_compr_cage_.reservation()->SetPermissions(
+        committed_region_address, committed_region_size,
+        PageAllocator::kReadWrite));
 
     if (Heap::ShouldZapGarbage()) {
       MemsetPointer(reinterpret_cast<Address*>(committed_region_address),
@@ -188,7 +184,7 @@ void IsolateAllocator::CommitPagesForIsolate(Address heap_reservation_address) {
   }
   isolate_memory_ = reinterpret_cast<void*>(isolate_address);
 }
-#endif  // V8_COMPRESS_POINTERS
+#endif  // V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE
 
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/init/isolate-allocator.h b/chromium/v8/src/init/isolate-allocator.h
index 9f894da1595..2bf739ec498 100644
--- a/chromium/v8/src/init/isolate-allocator.h
+++ b/chromium/v8/src/init/isolate-allocator.h
@@ -7,26 +7,24 @@
 
 #include <memory>
 
-#include "src/base/bounded-page-allocator.h"
 #include "src/base/page-allocator.h"
 #include "src/common/globals.h"
+#include "src/flags/flags.h"
 #include "src/utils/allocation.h"
 
 namespace v8 {
-
-// Forward declarations.
-namespace base {
-class BoundedPageAllocator;
-}  // namespace base
-
 namespace internal {
 
 // IsolateAllocator object is responsible for allocating memory for one (!)
 // Isolate object. Depending on the whether pointer compression is enabled,
 // the memory can be allocated
-// 1) in the C++ heap (when pointer compression is disabled)
+//
+// 1) in the C++ heap (when pointer compression is disabled or when multiple
+// Isolates share a pointer compression cage)
+//
 // 2) in a proper part of a properly aligned region of a reserved address space
-//   (when pointer compression is enabled).
+//   (when pointer compression is enabled and each Isolate has its own pointer
+//   compression cage).
 //
 // Isolate::New() first creates IsolateAllocator object which allocates the
 // memory and then it constructs Isolate object in this memory. Once it's done
@@ -44,15 +42,30 @@ class V8_EXPORT_PRIVATE IsolateAllocator final {
 
   v8::PageAllocator* page_allocator() const { return page_allocator_; }
 
+  Address GetPtrComprCageBase() const {
+    return COMPRESS_POINTERS_BOOL ? GetPtrComprCage()->base() : kNullAddress;
+  }
+
+  // When pointer compression is on, return the pointer compression
+  // cage. Otherwise return nullptr.
+  VirtualMemoryCage* GetPtrComprCage();
+  const VirtualMemoryCage* GetPtrComprCage() const;
+
+  static void InitializeOncePerProcess();
+
  private:
-  Address InitReservation();
-  void CommitPagesForIsolate(Address heap_reservation_address);
+  void CommitPagesForIsolate();
+
+  friend class SequentialUnmapperTest;
+  // Only used for testing.
+  static void FreeProcessWidePtrComprCageForTesting();
 
   // The allocated memory for Isolate instance.
   void* isolate_memory_ = nullptr;
   v8::PageAllocator* page_allocator_ = nullptr;
-  std::unique_ptr<base::BoundedPageAllocator> page_allocator_instance_;
-  VirtualMemory reservation_;
+#ifdef V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE
+  VirtualMemoryCage isolate_ptr_compr_cage_;
+#endif
 };
 
 }  // namespace internal
diff --git a/chromium/v8/src/init/v8.cc b/chromium/v8/src/init/v8.cc
index fbf120b1b61..e14d02efbdc 100644
--- a/chromium/v8/src/init/v8.cc
+++ b/chromium/v8/src/init/v8.cc
@@ -133,6 +133,26 @@ void V8::InitializeOncePerProcessImpl() {
   }
 #endif
 
+  // When fuzzing and concurrent compilation is enabled, disable Turbofan
+  // tracing flags since reading/printing heap state is not thread-safe and
+  // leads to false positives on TSAN bots.
+  // TODO(chromium:1205289): Teach relevant fuzzers to not pass TF tracing
+  // flags instead, and remove this section.
+  if (FLAG_fuzzing && FLAG_concurrent_recompilation) {
+    FLAG_trace_turbo = false;
+    FLAG_trace_turbo_graph = false;
+    FLAG_trace_turbo_scheduled = false;
+    FLAG_trace_turbo_reduction = false;
+    FLAG_trace_turbo_trimming = false;
+    FLAG_trace_turbo_jt = false;
+    FLAG_trace_turbo_ceq = false;
+    FLAG_trace_turbo_loop = false;
+    FLAG_trace_turbo_alloc = false;
+    FLAG_trace_all_uses = false;
+    FLAG_trace_representation = false;
+    FLAG_trace_turbo_stack_accesses = false;
+  }
+
   if (FLAG_regexp_interpret_all && FLAG_regexp_tier_up) {
     // Turning off the tier-up strategy, because the --regexp-interpret-all and
     // --regexp-tier-up flags are incompatible.
@@ -151,6 +171,7 @@ void V8::InitializeOncePerProcessImpl() {
 #if defined(V8_USE_PERFETTO)
   if (perfetto::Tracing::IsInitialized()) TrackEvent::Register();
 #endif
+  IsolateAllocator::InitializeOncePerProcess();
   Isolate::InitializeOncePerProcess();
 
 #if defined(USE_SIMULATOR)
@@ -163,6 +184,8 @@ void V8::InitializeOncePerProcessImpl() {
 #if V8_ENABLE_WEBASSEMBLY
   wasm::WasmEngine::InitializeOncePerProcess();
 #endif  // V8_ENABLE_WEBASSEMBLY
+
+  ExternalReferenceTable::InitializeOncePerProcess();
 }
 
 void V8::InitializeOncePerProcess() {
diff --git a/chromium/v8/src/inspector/injected-script.cc b/chromium/v8/src/inspector/injected-script.cc
index 992ff50fe7d..fc029e937aa 100644
--- a/chromium/v8/src/inspector/injected-script.cc
+++ b/chromium/v8/src/inspector/injected-script.cc
@@ -302,7 +302,8 @@ class InjectedScript::ProtocolPromiseHandler {
       exceptionDetails->setStackTrace(
           stack->buildInspectorObjectImpl(m_inspector->debugger()));
     if (stack && !stack->isEmpty())
-      exceptionDetails->setScriptId(toString16(stack->topScriptId()));
+      exceptionDetails->setScriptId(
+          String16::fromInteger(stack->topScriptId()));
     callback->sendSuccess(std::move(wrappedValue), std::move(exceptionDetails));
   }
 
diff --git a/chromium/v8/src/inspector/injected-script.h b/chromium/v8/src/inspector/injected-script.h
index 01d0ff06653..9971d7da3a7 100644
--- a/chromium/v8/src/inspector/injected-script.h
+++ b/chromium/v8/src/inspector/injected-script.h
@@ -173,7 +173,8 @@ class InjectedScript final {
     int m_sessionId;
   };
 
-  class ContextScope : public Scope {
+  class ContextScope : public Scope,
+                       public V8InspectorSession::CommandLineAPIScope {
    public:
     ContextScope(V8InspectorSessionImpl*, int executionContextId);
     ~ContextScope() override;
diff --git a/chromium/v8/src/inspector/string-16.h b/chromium/v8/src/inspector/string-16.h
index 88a7584255f..b38917185e8 100644
--- a/chromium/v8/src/inspector/string-16.h
+++ b/chromium/v8/src/inspector/string-16.h
@@ -27,8 +27,8 @@ class String16 {
   String16(const String16&) V8_NOEXCEPT = default;
   String16(String16&&) V8_NOEXCEPT = default;
   String16(const UChar* characters, size_t size);
-  V8_EXPORT String16(const UChar* characters);  // NOLINT(runtime/explicit)
-  V8_EXPORT String16(const char* characters);   // NOLINT(runtime/explicit)
+  V8_EXPORT String16(const UChar* characters);
+  V8_EXPORT String16(const char* characters);
   String16(const char* characters, size_t size);
   explicit String16(const std::basic_string<UChar>& impl);
   explicit String16(std::basic_string<UChar>&& impl);
diff --git a/chromium/v8/src/inspector/v8-console-message.cc b/chromium/v8/src/inspector/v8-console-message.cc
index 58a37073a82..1b03a02c7bb 100644
--- a/chromium/v8/src/inspector/v8-console-message.cc
+++ b/chromium/v8/src/inspector/v8-console-message.cc
@@ -152,7 +152,7 @@ class V8ValueStringBuilder {
 
   bool append(v8::Local<v8::Symbol> symbol) {
     m_builder.append("Symbol(");
-    bool result = append(symbol->Description(), IgnoreUndefined);
+    bool result = append(symbol->Description(m_isolate), IgnoreUndefined);
     m_builder.append(')');
     return result;
   }
diff --git a/chromium/v8/src/inspector/v8-console.cc b/chromium/v8/src/inspector/v8-console.cc
index cc464ebe048..afe790fb62b 100644
--- a/chromium/v8/src/inspector/v8-console.cc
+++ b/chromium/v8/src/inspector/v8-console.cc
@@ -162,14 +162,9 @@ class ConsoleHelper {
   int m_groupId;
 };
 
-void returnDataCallback(const v8::FunctionCallbackInfo<v8::Value>& info) {
-  info.GetReturnValue().Set(info.Data());
-}
-
 void createBoundFunctionProperty(
     v8::Local<v8::Context> context, v8::Local<v8::Object> console,
     v8::Local<v8::Value> data, const char* name, v8::FunctionCallback callback,
-    const char* description = nullptr,
     v8::SideEffectType side_effect_type = v8::SideEffectType::kHasSideEffect) {
   v8::Local<v8::String> funcName =
       toV8StringInternalized(context->GetIsolate(), name);
@@ -179,18 +174,6 @@ void createBoundFunctionProperty(
            .ToLocal(&func))
     return;
   func->SetName(funcName);
-  if (description) {
-    v8::Local<v8::String> returnValue =
-        toV8String(context->GetIsolate(), description);
-    v8::Local<v8::Function> toStringFunction;
-    if (v8::Function::New(context, returnDataCallback, returnValue, 0,
-                          v8::ConstructorBehavior::kThrow,
-                          v8::SideEffectType::kHasNoSideEffect)
-            .ToLocal(&toStringFunction))
-      createDataProperty(context, func, toV8StringInternalized(
-                                            context->GetIsolate(), "toString"),
-                         toStringFunction);
-  }
   createDataProperty(context, console, funcName, func);
 }
 
@@ -498,11 +481,11 @@ void V8Console::valuesCallback(const v8::FunctionCallbackInfo<v8::Value>& info,
   info.GetReturnValue().Set(values);
 }
 
-static void setFunctionBreakpoint(
-    ConsoleHelper& helper,  // NOLINT(runtime/references)
-    int sessionId, v8::Local<v8::Function> function,
-    V8DebuggerAgentImpl::BreakpointSource source,
-    v8::Local<v8::String> condition, bool enable) {
+static void setFunctionBreakpoint(ConsoleHelper& helper, int sessionId,
+                                  v8::Local<v8::Function> function,
+                                  V8DebuggerAgentImpl::BreakpointSource source,
+                                  v8::Local<v8::String> condition,
+                                  bool enable) {
   V8InspectorSessionImpl* session = helper.session(sessionId);
   if (session == nullptr) return;
   if (!session->debuggerAgent()->enabled()) return;
@@ -557,8 +540,9 @@ void V8Console::monitorFunctionCallback(
   else
     builder.append(functionName);
   builder.append(
-      " called\" + (arguments.length > 0 ? \" with arguments: \" + "
-      "Array.prototype.join.call(arguments, \", \") : \"\")) && false");
+      " called\" + (typeof arguments !== \"undefined\" && arguments.length > 0 "
+      "? \" with arguments: \" + Array.prototype.join.call(arguments, \", \") "
+      ": \"\")) && false");
   setFunctionBreakpoint(helper, sessionId, function,
                         V8DebuggerAgentImpl::MonitorCommandBreakpointSource,
                         toV8String(info.GetIsolate(), builder.toString()),
@@ -696,80 +680,62 @@ v8::Local<v8::Object> V8Console::createCommandLineAPI(
   *static_cast<CommandLineAPIData*>(data->GetBackingStore()->Data()) =
       CommandLineAPIData(this, sessionId);
   createBoundFunctionProperty(context, commandLineAPI, data, "dir",
-                              &V8Console::call<&V8Console::Dir>,
-                              "function dir(value) { [Command Line API] }");
+                              &V8Console::call<&V8Console::Dir>);
   createBoundFunctionProperty(context, commandLineAPI, data, "dirxml",
-                              &V8Console::call<&V8Console::DirXml>,
-                              "function dirxml(value) { [Command Line API] }");
+                              &V8Console::call<&V8Console::DirXml>);
   createBoundFunctionProperty(context, commandLineAPI, data, "profile",
-                              &V8Console::call<&V8Console::Profile>,
-                              "function profile(title) { [Command Line API] }");
-  createBoundFunctionProperty(
-      context, commandLineAPI, data, "profileEnd",
-      &V8Console::call<&V8Console::ProfileEnd>,
-      "function profileEnd(title) { [Command Line API] }");
+                              &V8Console::call<&V8Console::Profile>);
+  createBoundFunctionProperty(context, commandLineAPI, data, "profileEnd",
+                              &V8Console::call<&V8Console::ProfileEnd>);
   createBoundFunctionProperty(context, commandLineAPI, data, "clear",
-                              &V8Console::call<&V8Console::Clear>,
-                              "function clear() { [Command Line API] }");
-  createBoundFunctionProperty(
-      context, commandLineAPI, data, "table",
-      &V8Console::call<&V8Console::Table>,
-      "function table(data, [columns]) { [Command Line API] }");
+                              &V8Console::call<&V8Console::Clear>);
+  createBoundFunctionProperty(context, commandLineAPI, data, "table",
+                              &V8Console::call<&V8Console::Table>);
 
   createBoundFunctionProperty(context, commandLineAPI, data, "keys",
                               &V8Console::call<&V8Console::keysCallback>,
-                              "function keys(object) { [Command Line API] }",
                               v8::SideEffectType::kHasNoSideEffect);
   createBoundFunctionProperty(context, commandLineAPI, data, "values",
                               &V8Console::call<&V8Console::valuesCallback>,
-                              "function values(object) { [Command Line API] }",
                               v8::SideEffectType::kHasNoSideEffect);
   createBoundFunctionProperty(
       context, commandLineAPI, data, "debug",
-      &V8Console::call<&V8Console::debugFunctionCallback>,
-      "function debug(function, condition) { [Command Line API] }");
+      &V8Console::call<&V8Console::debugFunctionCallback>);
   createBoundFunctionProperty(
       context, commandLineAPI, data, "undebug",
-      &V8Console::call<&V8Console::undebugFunctionCallback>,
-      "function undebug(function) { [Command Line API] }");
+      &V8Console::call<&V8Console::undebugFunctionCallback>);
   createBoundFunctionProperty(
       context, commandLineAPI, data, "monitor",
-      &V8Console::call<&V8Console::monitorFunctionCallback>,
-      "function monitor(function) { [Command Line API] }");
+      &V8Console::call<&V8Console::monitorFunctionCallback>);
   createBoundFunctionProperty(
       context, commandLineAPI, data, "unmonitor",
-      &V8Console::call<&V8Console::unmonitorFunctionCallback>,
-      "function unmonitor(function) { [Command Line API] }");
-  createBoundFunctionProperty(
-      context, commandLineAPI, data, "inspect",
-      &V8Console::call<&V8Console::inspectCallback>,
-      "function inspect(object) { [Command Line API] }");
+      &V8Console::call<&V8Console::unmonitorFunctionCallback>);
+  createBoundFunctionProperty(context, commandLineAPI, data, "inspect",
+                              &V8Console::call<&V8Console::inspectCallback>);
   createBoundFunctionProperty(context, commandLineAPI, data, "copy",
-                              &V8Console::call<&V8Console::copyCallback>,
-                              "function copy(value) { [Command Line API] }");
+                              &V8Console::call<&V8Console::copyCallback>);
   createBoundFunctionProperty(
       context, commandLineAPI, data, "queryObjects",
-      &V8Console::call<&V8Console::queryObjectsCallback>,
-      "function queryObjects(constructor) { [Command Line API] }");
+      &V8Console::call<&V8Console::queryObjectsCallback>);
   createBoundFunctionProperty(
       context, commandLineAPI, data, "$_",
-      &V8Console::call<&V8Console::lastEvaluationResultCallback>, nullptr,
+      &V8Console::call<&V8Console::lastEvaluationResultCallback>,
       v8::SideEffectType::kHasNoSideEffect);
   createBoundFunctionProperty(context, commandLineAPI, data, "$0",
                               &V8Console::call<&V8Console::inspectedObject0>,
-                              nullptr, v8::SideEffectType::kHasNoSideEffect);
+                              v8::SideEffectType::kHasNoSideEffect);
   createBoundFunctionProperty(context, commandLineAPI, data, "$1",
                               &V8Console::call<&V8Console::inspectedObject1>,
-                              nullptr, v8::SideEffectType::kHasNoSideEffect);
+                              v8::SideEffectType::kHasNoSideEffect);
   createBoundFunctionProperty(context, commandLineAPI, data, "$2",
                               &V8Console::call<&V8Console::inspectedObject2>,
-                              nullptr, v8::SideEffectType::kHasNoSideEffect);
+                              v8::SideEffectType::kHasNoSideEffect);
   createBoundFunctionProperty(context, commandLineAPI, data, "$3",
                               &V8Console::call<&V8Console::inspectedObject3>,
-                              nullptr, v8::SideEffectType::kHasNoSideEffect);
+                              v8::SideEffectType::kHasNoSideEffect);
   createBoundFunctionProperty(context, commandLineAPI, data, "$4",
                               &V8Console::call<&V8Console::inspectedObject4>,
-                              nullptr, v8::SideEffectType::kHasNoSideEffect);
+                              v8::SideEffectType::kHasNoSideEffect);
 
   m_inspector->client()->installAdditionalCommandLineAPI(context,
                                                          commandLineAPI);
diff --git a/chromium/v8/src/inspector/v8-debugger-agent-impl.cc b/chromium/v8/src/inspector/v8-debugger-agent-impl.cc
index f99d57d33e3..6b54e192a54 100644
--- a/chromium/v8/src/inspector/v8-debugger-agent-impl.cc
+++ b/chromium/v8/src/inspector/v8-debugger-agent-impl.cc
@@ -1042,23 +1042,7 @@ Response V8DebuggerAgentImpl::restartFrame(
     std::unique_ptr<Array<CallFrame>>* newCallFrames,
     Maybe<protocol::Runtime::StackTrace>* asyncStackTrace,
     Maybe<protocol::Runtime::StackTraceId>* asyncStackTraceId) {
-  if (!isPaused()) return Response::ServerError(kDebuggerNotPaused);
-  InjectedScript::CallFrameScope scope(m_session, callFrameId);
-  Response response = scope.initialize();
-  if (!response.IsSuccess()) return response;
-  int frameOrdinal = static_cast<int>(scope.frameOrdinal());
-  auto it = v8::debug::StackTraceIterator::Create(m_isolate, frameOrdinal);
-  if (it->Done()) {
-    return Response::ServerError("Could not find call frame with given id");
-  }
-  if (!it->Restart()) {
-    return Response::InternalError();
-  }
-  response = currentCallFrames(newCallFrames);
-  if (!response.IsSuccess()) return response;
-  *asyncStackTrace = currentAsyncStackTrace();
-  *asyncStackTraceId = currentExternalStackTrace();
-  return Response::Success();
+  return Response::ServerError("Frame restarting not supported");
 }
 
 Response V8DebuggerAgentImpl::getScriptSource(
diff --git a/chromium/v8/src/inspector/v8-debugger.cc b/chromium/v8/src/inspector/v8-debugger.cc
index 9f035b578ef..6887657239d 100644
--- a/chromium/v8/src/inspector/v8-debugger.cc
+++ b/chromium/v8/src/inspector/v8-debugger.cc
@@ -24,7 +24,7 @@ static const int kMaxAsyncTaskStacks = 128 * 1024;
 static const int kNoBreakpointId = 0;
 
 template <typename Map>
-void cleanupExpiredWeakPointers(Map& map) {  // NOLINT(runtime/references)
+void cleanupExpiredWeakPointers(Map& map) {
   for (auto it = map.begin(); it != map.end();) {
     if (it->second.expired()) {
       it = map.erase(it);
diff --git a/chromium/v8/src/inspector/v8-heap-profiler-agent-impl.cc b/chromium/v8/src/inspector/v8-heap-profiler-agent-impl.cc
index 6472c5ca94e..b441be565c9 100644
--- a/chromium/v8/src/inspector/v8-heap-profiler-agent-impl.cc
+++ b/chromium/v8/src/inspector/v8-heap-profiler-agent-impl.cc
@@ -232,10 +232,12 @@ Response V8HeapProfilerAgentImpl::startTrackingHeapObjects(
 }
 
 Response V8HeapProfilerAgentImpl::stopTrackingHeapObjects(
-    Maybe<bool> reportProgress, Maybe<bool> treatGlobalObjectsAsRoots) {
+    Maybe<bool> reportProgress, Maybe<bool> treatGlobalObjectsAsRoots,
+    Maybe<bool> captureNumericValue) {
   requestHeapStatsUpdate();
   takeHeapSnapshot(std::move(reportProgress),
-                   std::move(treatGlobalObjectsAsRoots));
+                   std::move(treatGlobalObjectsAsRoots),
+                   std::move(captureNumericValue));
   stopTrackingHeapObjectsInternal();
   return Response::Success();
 }
@@ -258,7 +260,8 @@ Response V8HeapProfilerAgentImpl::disable() {
 }
 
 Response V8HeapProfilerAgentImpl::takeHeapSnapshot(
-    Maybe<bool> reportProgress, Maybe<bool> treatGlobalObjectsAsRoots) {
+    Maybe<bool> reportProgress, Maybe<bool> treatGlobalObjectsAsRoots,
+    Maybe<bool> captureNumericValue) {
   v8::HeapProfiler* profiler = m_isolate->GetHeapProfiler();
   if (!profiler) return Response::ServerError("Cannot access v8 heap profiler");
   std::unique_ptr<HeapSnapshotProgress> progress;
@@ -267,7 +270,8 @@ Response V8HeapProfilerAgentImpl::takeHeapSnapshot(
 
   GlobalObjectNameResolver resolver(m_session);
   const v8::HeapSnapshot* snapshot = profiler->TakeHeapSnapshot(
-      progress.get(), &resolver, treatGlobalObjectsAsRoots.fromMaybe(true));
+      progress.get(), &resolver, treatGlobalObjectsAsRoots.fromMaybe(true),
+      captureNumericValue.fromMaybe(false));
   if (!snapshot) return Response::ServerError("Failed to take heap snapshot");
   HeapSnapshotOutputStream stream(&m_frontend);
   snapshot->Serialize(&stream);
@@ -375,6 +379,9 @@ Response V8HeapProfilerAgentImpl::startSampling(
   const unsigned defaultSamplingInterval = 1 << 15;
   double samplingIntervalValue =
       samplingInterval.fromMaybe(defaultSamplingInterval);
+  if (samplingIntervalValue <= 0.0) {
+    return Response::ServerError("Invalid sampling interval");
+  }
   m_state->setDouble(HeapProfilerAgentState::samplingHeapProfilerInterval,
                      samplingIntervalValue);
   m_state->setBoolean(HeapProfilerAgentState::samplingHeapProfilerEnabled,
diff --git a/chromium/v8/src/inspector/v8-heap-profiler-agent-impl.h b/chromium/v8/src/inspector/v8-heap-profiler-agent-impl.h
index b9babdb9898..feda75ffb71 100644
--- a/chromium/v8/src/inspector/v8-heap-profiler-agent-impl.h
+++ b/chromium/v8/src/inspector/v8-heap-profiler-agent-impl.h
@@ -34,14 +34,15 @@ class V8HeapProfilerAgentImpl : public protocol::HeapProfiler::Backend {
 
   Response enable() override;
   Response startTrackingHeapObjects(Maybe<bool> trackAllocations) override;
-  Response stopTrackingHeapObjects(
-      Maybe<bool> reportProgress,
-      Maybe<bool> treatGlobalObjectsAsRoots) override;
+  Response stopTrackingHeapObjects(Maybe<bool> reportProgress,
+                                   Maybe<bool> treatGlobalObjectsAsRoots,
+                                   Maybe<bool> captureNumericValue) override;
 
   Response disable() override;
 
   Response takeHeapSnapshot(Maybe<bool> reportProgress,
-                            Maybe<bool> treatGlobalObjectsAsRoots) override;
+                            Maybe<bool> treatGlobalObjectsAsRoots,
+                            Maybe<bool> captureNumericValue) override;
 
   Response getObjectByHeapObjectId(
       const String16& heapSnapshotObjectId, Maybe<String16> objectGroup,
diff --git a/chromium/v8/src/inspector/v8-inspector-session-impl.cc b/chromium/v8/src/inspector/v8-inspector-session-impl.cc
index 02b694a1a98..b926ddfbba7 100644
--- a/chromium/v8/src/inspector/v8-inspector-session-impl.cc
+++ b/chromium/v8/src/inspector/v8-inspector-session-impl.cc
@@ -155,6 +155,20 @@ V8InspectorSessionImpl::~V8InspectorSessionImpl() {
   m_inspector->disconnect(this);
 }
 
+std::unique_ptr<V8InspectorSession::CommandLineAPIScope>
+V8InspectorSessionImpl::initializeCommandLineAPIScope(int executionContextId) {
+  auto scope =
+      std::make_unique<InjectedScript::ContextScope>(this, executionContextId);
+  auto result = scope->initialize();
+  if (!result.IsSuccess()) {
+    return nullptr;
+  }
+
+  scope->installCommandLineAPI();
+
+  return scope;
+}
+
 protocol::DictionaryValue* V8InspectorSessionImpl::agentState(
     const String16& name) {
   protocol::DictionaryValue* state = m_state->getObject(name);
diff --git a/chromium/v8/src/inspector/v8-inspector-session-impl.h b/chromium/v8/src/inspector/v8-inspector-session-impl.h
index db530385aab..115c15c5faa 100644
--- a/chromium/v8/src/inspector/v8-inspector-session-impl.h
+++ b/chromium/v8/src/inspector/v8-inspector-session-impl.h
@@ -50,6 +50,9 @@ class V8InspectorSessionImpl : public V8InspectorSession,
   int contextGroupId() const { return m_contextGroupId; }
   int sessionId() const { return m_sessionId; }
 
+  std::unique_ptr<V8InspectorSession::CommandLineAPIScope>
+  initializeCommandLineAPIScope(int executionContextId) override;
+
   Response findInjectedScript(int contextId, InjectedScript*&);
   Response findInjectedScript(RemoteObjectIdBase*, InjectedScript*&);
   void reset();
diff --git a/chromium/v8/src/inspector/v8-profiler-agent-impl.cc b/chromium/v8/src/inspector/v8-profiler-agent-impl.cc
index 47be9448799..8ebee1fd21a 100644
--- a/chromium/v8/src/inspector/v8-profiler-agent-impl.cc
+++ b/chromium/v8/src/inspector/v8-profiler-agent-impl.cc
@@ -150,10 +150,11 @@ std::unique_ptr<protocol::Debugger::Location> currentDebugLocation(
     V8InspectorImpl* inspector) {
   std::unique_ptr<V8StackTraceImpl> callStack =
       inspector->debugger()->captureStackTrace(false /* fullStack */);
-  auto location = protocol::Debugger::Location::create()
-                      .setScriptId(toString16(callStack->topScriptId()))
-                      .setLineNumber(callStack->topLineNumber())
-                      .build();
+  auto location =
+      protocol::Debugger::Location::create()
+          .setScriptId(String16::fromInteger(callStack->topScriptId()))
+          .setLineNumber(callStack->topLineNumber())
+          .build();
   location->setColumnNumber(callStack->topColumnNumber());
   return location;
 }
diff --git a/chromium/v8/src/inspector/v8-runtime-agent-impl.cc b/chromium/v8/src/inspector/v8-runtime-agent-impl.cc
index 6fee3b3b05f..97fc07a6bf0 100644
--- a/chromium/v8/src/inspector/v8-runtime-agent-impl.cc
+++ b/chromium/v8/src/inspector/v8-runtime-agent-impl.cc
@@ -109,8 +109,7 @@ bool wrapEvaluateResultAsync(InjectedScript* injectedScript,
 }
 
 void innerCallFunctionOn(
-    V8InspectorSessionImpl* session,
-    InjectedScript::Scope& scope,  // NOLINT(runtime/references)
+    V8InspectorSessionImpl* session, InjectedScript::Scope& scope,
     v8::Local<v8::Value> recv, const String16& expression,
     Maybe<protocol::Array<protocol::Runtime::CallArgument>> optionalArguments,
     bool silent, WrapMode wrapMode, bool userGesture, bool awaitPromise,
@@ -694,7 +693,6 @@ protocol::DictionaryValue* getOrCreateDictionary(
 Response V8RuntimeAgentImpl::addBinding(const String16& name,
                                         Maybe<int> executionContextId,
                                         Maybe<String16> executionContextName) {
-  if (m_activeBindings.count(name)) return Response::Success();
   if (executionContextId.isJust()) {
     if (executionContextName.isJust()) {
       return Response::InvalidParams(
@@ -743,8 +741,8 @@ void V8RuntimeAgentImpl::bindingCallback(
     const v8::FunctionCallbackInfo<v8::Value>& info) {
   v8::Isolate* isolate = info.GetIsolate();
   if (info.Length() != 1 || !info[0]->IsString()) {
-    info.GetIsolate()->ThrowException(toV8String(
-        isolate, "Invalid arguments: should be exactly one string."));
+    info.GetIsolate()->ThrowError(
+        "Invalid arguments: should be exactly one string.");
     return;
   }
   V8InspectorImpl* inspector =
@@ -764,6 +762,10 @@ void V8RuntimeAgentImpl::bindingCallback(
 
 void V8RuntimeAgentImpl::addBinding(InspectedContext* context,
                                     const String16& name) {
+  auto it = m_activeBindings.find(name);
+  if (it != m_activeBindings.end() && it->second.count(context->contextId())) {
+    return;
+  }
   v8::HandleScope handles(m_inspector->isolate());
   v8::Local<v8::Context> localContext = context->context();
   v8::Local<v8::Object> global = localContext->Global();
@@ -775,7 +777,12 @@ void V8RuntimeAgentImpl::addBinding(InspectedContext* context,
           .ToLocal(&functionValue)) {
     v8::Maybe<bool> success = global->Set(localContext, v8Name, functionValue);
     USE(success);
-    m_activeBindings.insert(name);
+    if (it == m_activeBindings.end()) {
+      m_activeBindings.emplace(name,
+                               std::unordered_set<int>(context->contextId()));
+    } else {
+      m_activeBindings.at(name).insert(context->contextId());
+    }
   }
 }
 
diff --git a/chromium/v8/src/inspector/v8-runtime-agent-impl.h b/chromium/v8/src/inspector/v8-runtime-agent-impl.h
index 5ac1e462f89..4694adae277 100644
--- a/chromium/v8/src/inspector/v8-runtime-agent-impl.h
+++ b/chromium/v8/src/inspector/v8-runtime-agent-impl.h
@@ -148,7 +148,8 @@ class V8RuntimeAgentImpl : public protocol::Runtime::Backend {
   bool m_enabled;
   std::unordered_map<String16, std::unique_ptr<v8::Global<v8::Script>>>
       m_compiledScripts;
-  std::set<String16> m_activeBindings;
+  // Binding name -> executionContextIds mapping.
+  std::unordered_map<String16, std::unordered_set<int>> m_activeBindings;
 };
 
 }  // namespace v8_inspector
diff --git a/chromium/v8/src/inspector/v8-stack-trace-impl.cc b/chromium/v8/src/inspector/v8-stack-trace-impl.cc
index 86bedc07ec7..3506c929966 100644
--- a/chromium/v8/src/inspector/v8-stack-trace-impl.cc
+++ b/chromium/v8/src/inspector/v8-stack-trace-impl.cc
@@ -7,6 +7,7 @@
 #include <algorithm>
 
 #include "../../third_party/inspector_protocol/crdtp/json.h"
+#include "src/debug/debug-interface.h"
 #include "src/inspector/v8-debugger.h"
 #include "src/inspector/v8-inspector-impl.h"
 #include "src/tracing/trace-event.h"
@@ -175,9 +176,9 @@ std::unique_ptr<StringBuffer> V8StackTraceId::ToString() {
 }
 
 StackFrame::StackFrame(v8::Isolate* isolate, v8::Local<v8::StackFrame> v8Frame)
-    : m_functionName(toProtocolString(isolate, v8Frame->GetFunctionName())),
+    : m_functionName(
+          toProtocolString(isolate, v8::debug::GetFunctionDebugName(v8Frame))),
       m_scriptId(v8Frame->GetScriptId()),
-      m_scriptIdAsString(String16::fromInteger(v8Frame->GetScriptId())),
       m_sourceURL(
           toProtocolString(isolate, v8Frame->GetScriptNameOrSourceURL())),
       m_lineNumber(v8Frame->GetLineNumber() - 1),
@@ -192,10 +193,6 @@ const String16& StackFrame::functionName() const { return m_functionName; }
 
 int StackFrame::scriptId() const { return m_scriptId; }
 
-const String16& StackFrame::scriptIdAsString() const {
-  return m_scriptIdAsString;
-}
-
 const String16& StackFrame::sourceURL() const { return m_sourceURL; }
 
 int StackFrame::lineNumber() const { return m_lineNumber; }
@@ -324,13 +321,7 @@ int V8StackTraceImpl::topColumnNumber() const {
   return m_frames[0]->columnNumber() + 1;
 }
 
-StringView V8StackTraceImpl::topScriptId() const {
-  return toStringView(m_frames[0]->scriptIdAsString());
-}
-
-int V8StackTraceImpl::topScriptIdAsInteger() const {
-  return m_frames[0]->scriptId();
-}
+int V8StackTraceImpl::topScriptId() const { return m_frames[0]->scriptId(); }
 
 StringView V8StackTraceImpl::topFunctionName() const {
   return toStringView(m_frames[0]->functionName());
diff --git a/chromium/v8/src/inspector/v8-stack-trace-impl.h b/chromium/v8/src/inspector/v8-stack-trace-impl.h
index 3896c7371c3..065d5ce47cf 100644
--- a/chromium/v8/src/inspector/v8-stack-trace-impl.h
+++ b/chromium/v8/src/inspector/v8-stack-trace-impl.h
@@ -27,7 +27,6 @@ class StackFrame {
 
   const String16& functionName() const;
   int scriptId() const;
-  const String16& scriptIdAsString() const;
   const String16& sourceURL() const;
   int lineNumber() const;    // 0-based.
   int columnNumber() const;  // 0-based.
@@ -38,7 +37,6 @@ class StackFrame {
  private:
   String16 m_functionName;
   int m_scriptId;
-  String16 m_scriptIdAsString;
   String16 m_sourceURL;
   int m_lineNumber;    // 0-based.
   int m_columnNumber;  // 0-based.
@@ -75,8 +73,7 @@ class V8StackTraceImpl : public V8StackTrace {
   StringView topSourceURL() const override;
   int topLineNumber() const override;    // 1-based.
   int topColumnNumber() const override;  // 1-based.
-  StringView topScriptId() const override;
-  int topScriptIdAsInteger() const override;
+  int topScriptId() const override;
   StringView topFunctionName() const override;
   std::unique_ptr<protocol::Runtime::API::StackTrace> buildInspectorObject()
       const override;
diff --git a/chromium/v8/src/inspector/v8-string-conversions.cc b/chromium/v8/src/inspector/v8-string-conversions.cc
index 4ccf6351fb3..0c75e66b972 100644
--- a/chromium/v8/src/inspector/v8-string-conversions.cc
+++ b/chromium/v8/src/inspector/v8-string-conversions.cc
@@ -228,9 +228,7 @@ static const UChar32 offsetsFromUTF8[6] = {0x00000000UL,
                                            static_cast<UChar32>(0xFA082080UL),
                                            static_cast<UChar32>(0x82082080UL)};
 
-static inline UChar32 readUTF8Sequence(
-    const char*& sequence,  // NOLINT(runtime/references)
-    size_t length) {
+static inline UChar32 readUTF8Sequence(const char*& sequence, size_t length) {
   UChar32 character = 0;
 
   // The cases all fall through.
@@ -336,8 +334,7 @@ ConversionResult convertUTF8ToUTF16(const char** sourceStart,
 
 // Helper to write a three-byte UTF-8 code point to the buffer, caller must
 // check room is available.
-static inline void putUTF8Triple(char*& buffer,  // NOLINT(runtime/references)
-                                 UChar ch) {
+static inline void putUTF8Triple(char*& buffer, UChar ch) {
   *buffer++ = static_cast<char>(((ch >> 12) & 0x0F) | 0xE0);
   *buffer++ = static_cast<char>(((ch >> 6) & 0x3F) | 0x80);
   *buffer++ = static_cast<char>((ch & 0x3F) | 0x80);
diff --git a/chromium/v8/src/inspector/value-mirror.cc b/chromium/v8/src/inspector/value-mirror.cc
index 18d870a94a3..5348b76a120 100644
--- a/chromium/v8/src/inspector/value-mirror.cc
+++ b/chromium/v8/src/inspector/value-mirror.cc
@@ -165,10 +165,11 @@ String16 abbreviateString(const String16& value, AbbreviateMode mode) {
 
 String16 descriptionForSymbol(v8::Local<v8::Context> context,
                               v8::Local<v8::Symbol> symbol) {
-  return String16::concat("Symbol(",
-                          toProtocolStringWithTypeCheck(context->GetIsolate(),
-                                                        symbol->Description()),
-                          ")");
+  v8::Isolate* isolate = context->GetIsolate();
+  return String16::concat(
+      "Symbol(",
+      toProtocolStringWithTypeCheck(isolate, symbol->Description(isolate)),
+      ")");
 }
 
 String16 descriptionForBigInt(v8::Local<v8::Context> context,
@@ -194,21 +195,19 @@ String16 descriptionForPrimitiveType(v8::Local<v8::Context> context,
   return String16();
 }
 
-String16 descriptionForRegExp(v8::Isolate* isolate,
+String16 descriptionForObject(v8::Isolate* isolate,
+                              v8::Local<v8::Object> object) {
+  return toProtocolString(isolate, object->GetConstructorName());
+}
+
+String16 descriptionForRegExp(v8::Local<v8::Context> context,
                               v8::Local<v8::RegExp> value) {
-  String16Builder description;
-  description.append('/');
-  description.append(toProtocolString(isolate, value->GetSource()));
-  description.append('/');
-  v8::RegExp::Flags flags = value->GetFlags();
-  if (flags & v8::RegExp::Flags::kGlobal) description.append('g');
-  if (flags & v8::RegExp::Flags::kIgnoreCase) description.append('i');
-  if (flags & v8::RegExp::Flags::kLinear) description.append('l');
-  if (flags & v8::RegExp::Flags::kMultiline) description.append('m');
-  if (flags & v8::RegExp::Flags::kDotAll) description.append('s');
-  if (flags & v8::RegExp::Flags::kUnicode) description.append('u');
-  if (flags & v8::RegExp::Flags::kSticky) description.append('y');
-  return description.toString();
+  v8::Isolate* isolate = context->GetIsolate();
+  v8::Local<v8::String> description;
+  if (!value->ToString(context).ToLocal(&description)) {
+    return descriptionForObject(isolate, value);
+  }
+  return toProtocolString(isolate, description);
 }
 
 enum class ErrorType { kNative, kClient };
@@ -266,11 +265,6 @@ String16 descriptionForError(v8::Local<v8::Context> context,
   return description + stackWithoutMessage;
 }
 
-String16 descriptionForObject(v8::Isolate* isolate,
-                              v8::Local<v8::Object> object) {
-  return toProtocolString(isolate, object->GetConstructorName());
-}
-
 String16 descriptionForDate(v8::Local<v8::Context> context,
                             v8::Local<v8::Date> date) {
   v8::Isolate* isolate = context->GetIsolate();
@@ -355,14 +349,9 @@ String16 descriptionForEntry(v8::Local<v8::Context> context,
   return key.length() ? ("{" + key + " => " + value + "}") : value;
 }
 
-String16 descriptionForFunction(v8::Local<v8::Context> context,
-                                v8::Local<v8::Function> value) {
-  v8::Isolate* isolate = context->GetIsolate();
-  v8::TryCatch tryCatch(isolate);
-  v8::Local<v8::String> description;
-  if (!value->ToString(context).ToLocal(&description)) {
-    return descriptionForObject(isolate, value);
-  }
+String16 descriptionForFunction(v8::Local<v8::Function> value) {
+  v8::Isolate* isolate = value->GetIsolate();
+  v8::Local<v8::String> description = v8::debug::GetFunctionDescription(value);
   return toProtocolString(isolate, description);
 }
 
@@ -652,7 +641,7 @@ class FunctionMirror final : public ValueMirror {
                     .setType(RemoteObject::TypeEnum::Function)
                     .setClassName(toProtocolStringWithTypeCheck(
                         context->GetIsolate(), m_value->GetConstructorName()))
-                    .setDescription(descriptionForFunction(context, m_value))
+                    .setDescription(descriptionForFunction(m_value))
                     .build();
     }
     return Response::Success();
@@ -673,7 +662,7 @@ class FunctionMirror final : public ValueMirror {
     *preview =
         ObjectPreview::create()
             .setType(RemoteObject::TypeEnum::Function)
-            .setDescription(descriptionForFunction(context, m_value))
+            .setDescription(descriptionForFunction(m_value))
             .setOverflow(false)
             .setProperties(std::make_unique<protocol::Array<PropertyPreview>>())
             .build();
@@ -1216,7 +1205,6 @@ bool ValueMirror::getProperties(v8::Local<v8::Context> context,
       return false;
     }
   }
-  bool shouldSkipProto = internalType == V8InternalValueType::kScopeList;
 
   bool formatAccessorsAsProperties =
       clientFor(context)->formatAccessorsAsProperties(object);
@@ -1321,7 +1309,6 @@ bool ValueMirror::getProperties(v8::Local<v8::Context> context,
       }
     }
     if (accessorPropertiesOnly && !isAccessorProperty) continue;
-    if (name == "__proto__") shouldSkipProto = true;
     auto mirror = PropertyMirror{name,
                                  writable,
                                  configurable,
@@ -1340,16 +1327,6 @@ bool ValueMirror::getProperties(v8::Local<v8::Context> context,
       return false;
     }
   }
-  if (!shouldSkipProto && ownProperties && !object->IsProxy() &&
-      !accessorPropertiesOnly) {
-    v8::Local<v8::Value> prototype = object->GetPrototype();
-    if (prototype->IsObject()) {
-      accumulator->Add(PropertyMirror{String16("__proto__"), true, true, false,
-                                      true, false,
-                                      ValueMirror::create(context, prototype),
-                                      nullptr, nullptr, nullptr, nullptr});
-    }
-  }
   return true;
 }
 
@@ -1615,7 +1592,7 @@ std::unique_ptr<ValueMirror> ValueMirror::create(v8::Local<v8::Context> context,
   if (value->IsRegExp()) {
     return std::make_unique<ObjectMirror>(
         value, RemoteObject::SubtypeEnum::Regexp,
-        descriptionForRegExp(isolate, value.As<v8::RegExp>()));
+        descriptionForRegExp(context, value.As<v8::RegExp>()));
   }
   if (value->IsProxy()) {
     return std::make_unique<ObjectMirror>(
diff --git a/chromium/v8/src/interpreter/bytecode-array-builder.cc b/chromium/v8/src/interpreter/bytecode-array-builder.cc
index 63c07683e6d..23c622b0337 100644
--- a/chromium/v8/src/interpreter/bytecode-array-builder.cc
+++ b/chromium/v8/src/interpreter/bytecode-array-builder.cc
@@ -81,9 +81,8 @@ Register BytecodeArrayBuilder::Local(int index) const {
   return Register(index);
 }
 
-template <typename LocalIsolate>
-Handle<BytecodeArray> BytecodeArrayBuilder::ToBytecodeArray(
-    LocalIsolate* isolate) {
+template <typename IsolateT>
+Handle<BytecodeArray> BytecodeArrayBuilder::ToBytecodeArray(IsolateT* isolate) {
   DCHECK(RemainderOfBlockIsDead());
   DCHECK(!bytecode_generated_);
   bytecode_generated_ = true;
@@ -115,9 +114,9 @@ int BytecodeArrayBuilder::CheckBytecodeMatches(BytecodeArray bytecode) {
 }
 #endif
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<ByteArray> BytecodeArrayBuilder::ToSourcePositionTable(
-    LocalIsolate* isolate) {
+    IsolateT* isolate) {
   DCHECK(RemainderOfBlockIsDead());
 
   return bytecode_array_writer_.ToSourcePositionTable(isolate);
@@ -726,11 +725,13 @@ BytecodeArrayBuilder& BytecodeArrayBuilder::LoadGlobal(const AstRawString* name,
   DCHECK_EQ(GetTypeofModeFromSlotKind(feedback_vector_spec()->GetKind(
                 FeedbackVector::ToSlot(feedback_slot))),
             typeof_mode);
-  if (typeof_mode == INSIDE_TYPEOF) {
-    OutputLdaGlobalInsideTypeof(name_index, feedback_slot);
-  } else {
-    DCHECK_EQ(typeof_mode, NOT_INSIDE_TYPEOF);
-    OutputLdaGlobal(name_index, feedback_slot);
+  switch (typeof_mode) {
+    case TypeofMode::kInside:
+      OutputLdaGlobalInsideTypeof(name_index, feedback_slot);
+      break;
+    case TypeofMode::kNotInside:
+      OutputLdaGlobal(name_index, feedback_slot);
+      break;
   }
   return *this;
 }
@@ -775,11 +776,13 @@ BytecodeArrayBuilder& BytecodeArrayBuilder::StoreContextSlot(Register context,
 BytecodeArrayBuilder& BytecodeArrayBuilder::LoadLookupSlot(
     const AstRawString* name, TypeofMode typeof_mode) {
   size_t name_index = GetConstantPoolEntry(name);
-  if (typeof_mode == INSIDE_TYPEOF) {
-    OutputLdaLookupSlotInsideTypeof(name_index);
-  } else {
-    DCHECK_EQ(typeof_mode, NOT_INSIDE_TYPEOF);
-    OutputLdaLookupSlot(name_index);
+  switch (typeof_mode) {
+    case TypeofMode::kInside:
+      OutputLdaLookupSlotInsideTypeof(name_index);
+      break;
+    case TypeofMode::kNotInside:
+      OutputLdaLookupSlot(name_index);
+      break;
   }
   return *this;
 }
@@ -788,11 +791,13 @@ BytecodeArrayBuilder& BytecodeArrayBuilder::LoadLookupContextSlot(
     const AstRawString* name, TypeofMode typeof_mode, int slot_index,
     int depth) {
   size_t name_index = GetConstantPoolEntry(name);
-  if (typeof_mode == INSIDE_TYPEOF) {
-    OutputLdaLookupContextSlotInsideTypeof(name_index, slot_index, depth);
-  } else {
-    DCHECK(typeof_mode == NOT_INSIDE_TYPEOF);
-    OutputLdaLookupContextSlot(name_index, slot_index, depth);
+  switch (typeof_mode) {
+    case TypeofMode::kInside:
+      OutputLdaLookupContextSlotInsideTypeof(name_index, slot_index, depth);
+      break;
+    case TypeofMode::kNotInside:
+      OutputLdaLookupContextSlot(name_index, slot_index, depth);
+      break;
   }
   return *this;
 }
@@ -801,11 +806,13 @@ BytecodeArrayBuilder& BytecodeArrayBuilder::LoadLookupGlobalSlot(
     const AstRawString* name, TypeofMode typeof_mode, int feedback_slot,
     int depth) {
   size_t name_index = GetConstantPoolEntry(name);
-  if (typeof_mode == INSIDE_TYPEOF) {
-    OutputLdaLookupGlobalSlotInsideTypeof(name_index, feedback_slot, depth);
-  } else {
-    DCHECK(typeof_mode == NOT_INSIDE_TYPEOF);
-    OutputLdaLookupGlobalSlot(name_index, feedback_slot, depth);
+  switch (typeof_mode) {
+    case TypeofMode::kInside:
+      OutputLdaLookupGlobalSlotInsideTypeof(name_index, feedback_slot, depth);
+      break;
+    case TypeofMode::kNotInside:
+      OutputLdaLookupGlobalSlot(name_index, feedback_slot, depth);
+      break;
   }
   return *this;
 }
diff --git a/chromium/v8/src/interpreter/bytecode-array-builder.h b/chromium/v8/src/interpreter/bytecode-array-builder.h
index 28716b401bb..3d72777c5a4 100644
--- a/chromium/v8/src/interpreter/bytecode-array-builder.h
+++ b/chromium/v8/src/interpreter/bytecode-array-builder.h
@@ -46,12 +46,12 @@ class V8_EXPORT_PRIVATE BytecodeArrayBuilder final {
   BytecodeArrayBuilder(const BytecodeArrayBuilder&) = delete;
   BytecodeArrayBuilder& operator=(const BytecodeArrayBuilder&) = delete;
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-  Handle<BytecodeArray> ToBytecodeArray(LocalIsolate* isolate);
-  template <typename LocalIsolate>
+  Handle<BytecodeArray> ToBytecodeArray(IsolateT* isolate);
+  template <typename IsolateT>
   EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-  Handle<ByteArray> ToSourcePositionTable(LocalIsolate* isolate);
+  Handle<ByteArray> ToSourcePositionTable(IsolateT* isolate);
 
 #ifdef DEBUG
   int CheckBytecodeMatches(BytecodeArray bytecode);
diff --git a/chromium/v8/src/interpreter/bytecode-array-iterator.cc b/chromium/v8/src/interpreter/bytecode-array-iterator.cc
index 2579f5d3782..bb1fdcb95ff 100644
--- a/chromium/v8/src/interpreter/bytecode-array-iterator.cc
+++ b/chromium/v8/src/interpreter/bytecode-array-iterator.cc
@@ -207,9 +207,9 @@ Runtime::FunctionId BytecodeArrayIterator::GetIntrinsicIdOperand(
       static_cast<IntrinsicsHelper::IntrinsicId>(raw_id));
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<Object> BytecodeArrayIterator::GetConstantAtIndex(
-    int index, LocalIsolate* isolate) const {
+    int index, IsolateT* isolate) const {
   return handle(bytecode_array()->constant_pool().get(index), isolate);
 }
 
@@ -221,9 +221,9 @@ Smi BytecodeArrayIterator::GetConstantAtIndexAsSmi(int index) const {
   return Smi::cast(bytecode_array()->constant_pool().get(index));
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<Object> BytecodeArrayIterator::GetConstantForIndexOperand(
-    int operand_index, LocalIsolate* isolate) const {
+    int operand_index, IsolateT* isolate) const {
   return GetConstantAtIndex(GetIndexOperand(operand_index), isolate);
 }
 
diff --git a/chromium/v8/src/interpreter/bytecode-array-iterator.h b/chromium/v8/src/interpreter/bytecode-array-iterator.h
index d0c676d2a34..5e93cbccb86 100644
--- a/chromium/v8/src/interpreter/bytecode-array-iterator.h
+++ b/chromium/v8/src/interpreter/bytecode-array-iterator.h
@@ -115,13 +115,13 @@ class V8_EXPORT_PRIVATE BytecodeArrayIterator {
   Runtime::FunctionId GetRuntimeIdOperand(int operand_index) const;
   Runtime::FunctionId GetIntrinsicIdOperand(int operand_index) const;
   uint32_t GetNativeContextIndexOperand(int operand_index) const;
-  template <typename LocalIsolate>
-  Handle<Object> GetConstantAtIndex(int offset, LocalIsolate* isolate) const;
+  template <typename IsolateT>
+  Handle<Object> GetConstantAtIndex(int offset, IsolateT* isolate) const;
   bool IsConstantAtIndexSmi(int offset) const;
   Smi GetConstantAtIndexAsSmi(int offset) const;
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   Handle<Object> GetConstantForIndexOperand(int operand_index,
-                                            LocalIsolate* isolate) const;
+                                            IsolateT* isolate) const;
 
   // Returns the relative offset of the branch target at the current bytecode.
   // It is an error to call this method if the bytecode is not for a jump or
diff --git a/chromium/v8/src/interpreter/bytecode-array-writer.cc b/chromium/v8/src/interpreter/bytecode-array-writer.cc
index 0172d3626b5..2ed8e614bb2 100644
--- a/chromium/v8/src/interpreter/bytecode-array-writer.cc
+++ b/chromium/v8/src/interpreter/bytecode-array-writer.cc
@@ -37,9 +37,9 @@ BytecodeArrayWriter::BytecodeArrayWriter(
   bytecodes_.reserve(512);  // Derived via experimentation.
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<BytecodeArray> BytecodeArrayWriter::ToBytecodeArray(
-    LocalIsolate* isolate, int register_count, int parameter_count,
+    IsolateT* isolate, int register_count, int parameter_count,
     Handle<ByteArray> handler_table) {
   DCHECK_EQ(0, unbound_jumps_);
 
@@ -63,9 +63,9 @@ template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
         LocalIsolate* isolate, int register_count, int parameter_count,
         Handle<ByteArray> handler_table);
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<ByteArray> BytecodeArrayWriter::ToSourcePositionTable(
-    LocalIsolate* isolate) {
+    IsolateT* isolate) {
   DCHECK(!source_position_table_builder_.Lazy());
   Handle<ByteArray> source_position_table =
       source_position_table_builder_.Omit()
diff --git a/chromium/v8/src/interpreter/bytecode-array-writer.h b/chromium/v8/src/interpreter/bytecode-array-writer.h
index 6517ad9f5e3..9976f59c23b 100644
--- a/chromium/v8/src/interpreter/bytecode-array-writer.h
+++ b/chromium/v8/src/interpreter/bytecode-array-writer.h
@@ -55,15 +55,15 @@ class V8_EXPORT_PRIVATE BytecodeArrayWriter final {
 
   void SetFunctionEntrySourcePosition(int position);
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-  Handle<BytecodeArray> ToBytecodeArray(LocalIsolate* isolate,
-                                        int register_count, int parameter_count,
+  Handle<BytecodeArray> ToBytecodeArray(IsolateT* isolate, int register_count,
+                                        int parameter_count,
                                         Handle<ByteArray> handler_table);
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-  Handle<ByteArray> ToSourcePositionTable(LocalIsolate* isolate);
+  Handle<ByteArray> ToSourcePositionTable(IsolateT* isolate);
 
 #ifdef DEBUG
   // Returns -1 if they match or the offset of the first mismatching byte.
diff --git a/chromium/v8/src/interpreter/bytecode-generator.cc b/chromium/v8/src/interpreter/bytecode-generator.cc
index 76686a9d62e..a08c42126b6 100644
--- a/chromium/v8/src/interpreter/bytecode-generator.cc
+++ b/chromium/v8/src/interpreter/bytecode-generator.cc
@@ -740,11 +740,11 @@ class V8_NODISCARD BytecodeGenerator::TestResultScope final
 // Used to build a list of toplevel declaration data.
 class BytecodeGenerator::TopLevelDeclarationsBuilder final : public ZoneObject {
  public:
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   Handle<FixedArray> AllocateDeclarations(UnoptimizedCompilationInfo* info,
                                           BytecodeGenerator* generator,
                                           Handle<Script> script,
-                                          LocalIsolate* isolate) {
+                                          IsolateT* isolate) {
     DCHECK(has_constant_pool_entry_);
 
     Handle<FixedArray> data =
@@ -1187,14 +1187,14 @@ using NullContextScopeFor = typename NullContextScopeHelper<Isolate>::Type;
 
 }  // namespace
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<BytecodeArray> BytecodeGenerator::FinalizeBytecode(
-    LocalIsolate* isolate, Handle<Script> script) {
+    IsolateT* isolate, Handle<Script> script) {
   DCHECK_EQ(ThreadId::Current(), isolate->thread_id());
 #ifdef DEBUG
   // Unoptimized compilation should be context-independent. Verify that we don't
   // access the native context by nulling it out during finalization.
-  NullContextScopeFor<LocalIsolate> null_context_scope(isolate);
+  NullContextScopeFor<IsolateT> null_context_scope(isolate);
 #endif
 
   AllocateDeferredConstants(isolate, script);
@@ -1225,14 +1225,14 @@ template Handle<BytecodeArray> BytecodeGenerator::FinalizeBytecode(
 template Handle<BytecodeArray> BytecodeGenerator::FinalizeBytecode(
     LocalIsolate* isolate, Handle<Script> script);
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<ByteArray> BytecodeGenerator::FinalizeSourcePositionTable(
-    LocalIsolate* isolate) {
+    IsolateT* isolate) {
   DCHECK_EQ(ThreadId::Current(), isolate->thread_id());
 #ifdef DEBUG
   // Unoptimized compilation should be context-independent. Verify that we don't
   // access the native context by nulling it out during finalization.
-  NullContextScopeFor<LocalIsolate> null_context_scope(isolate);
+  NullContextScopeFor<IsolateT> null_context_scope(isolate);
 #endif
 
   Handle<ByteArray> source_position_table =
@@ -1257,8 +1257,8 @@ int BytecodeGenerator::CheckBytecodeMatches(BytecodeArray bytecode) {
 }
 #endif
 
-template <typename LocalIsolate>
-void BytecodeGenerator::AllocateDeferredConstants(LocalIsolate* isolate,
+template <typename IsolateT>
+void BytecodeGenerator::AllocateDeferredConstants(IsolateT* isolate,
                                                   Handle<Script> script) {
   if (top_level_builder()->has_top_level_declaration()) {
     // Build global declaration pair array.
@@ -3289,7 +3289,7 @@ void BytecodeGenerator::BuildVariableLoad(Variable* variable,
       break;
     }
     case VariableLocation::REPL_GLOBAL: {
-      DCHECK(variable->IsReplGlobalLet());
+      DCHECK(variable->IsReplGlobal());
       FeedbackSlot slot = GetCachedLoadGlobalICSlot(typeof_mode, variable);
       builder()->LoadGlobal(variable->raw_name(), feedback_index(slot),
                             typeof_mode);
@@ -3478,7 +3478,8 @@ void BytecodeGenerator::BuildVariableAssignment(
       break;
     }
     case VariableLocation::REPL_GLOBAL: {
-      // A let declaration like 'let x = 7' is effectively translated to:
+      // A let or const declaration like 'let x = 7' is effectively translated
+      // to:
       //   <top of the script>:
       //     ScriptContext.x = TheHole;
       //   ...
@@ -3488,19 +3489,23 @@ void BytecodeGenerator::BuildVariableAssignment(
       // The ScriptContext slot for 'x' that we store to here is not
       // necessarily the ScriptContext of this script, but rather the
       // first ScriptContext that has a slot for name 'x'.
-      DCHECK(variable->IsReplGlobalLet());
+      DCHECK(variable->IsReplGlobal());
       if (op == Token::INIT) {
         RegisterList store_args = register_allocator()->NewRegisterList(2);
         builder()
             ->StoreAccumulatorInRegister(store_args[1])
             .LoadLiteral(variable->raw_name())
             .StoreAccumulatorInRegister(store_args[0]);
-        builder()->CallRuntime(Runtime::kStoreGlobalNoHoleCheckForReplLet,
-                               store_args);
+        builder()->CallRuntime(
+            Runtime::kStoreGlobalNoHoleCheckForReplLetOrConst, store_args);
       } else {
-        FeedbackSlot slot =
-            GetCachedStoreGlobalICSlot(language_mode(), variable);
-        builder()->StoreGlobal(variable->raw_name(), feedback_index(slot));
+        if (mode == VariableMode::kConst) {
+          builder()->CallRuntime(Runtime::kThrowConstAssignError);
+        } else {
+          FeedbackSlot slot =
+              GetCachedStoreGlobalICSlot(language_mode(), variable);
+          builder()->StoreGlobal(variable->raw_name(), feedback_index(slot));
+        }
       }
       break;
     }
@@ -5420,7 +5425,7 @@ void BytecodeGenerator::VisitForTypeOfValue(Expression* expr) {
     // perform a non-contextual load in case the operand is a variable proxy.
     VariableProxy* proxy = expr->AsVariableProxy();
     BuildVariableLoadForAccumulatorValue(proxy->var(), proxy->hole_check_mode(),
-                                         INSIDE_TYPEOF);
+                                         TypeofMode::kInside);
   } else {
     VisitForAccumulatorValue(expr);
   }
@@ -6850,7 +6855,7 @@ int BytecodeGenerator::feedback_index(FeedbackSlot slot) const {
 FeedbackSlot BytecodeGenerator::GetCachedLoadGlobalICSlot(
     TypeofMode typeof_mode, Variable* variable) {
   FeedbackSlotCache::SlotKind slot_kind =
-      typeof_mode == INSIDE_TYPEOF
+      typeof_mode == TypeofMode::kInside
           ? FeedbackSlotCache::SlotKind::kLoadGlobalInsideTypeof
           : FeedbackSlotCache::SlotKind::kLoadGlobalNotInsideTypeof;
   FeedbackSlot slot(feedback_slot_cache()->Get(slot_kind, variable));
diff --git a/chromium/v8/src/interpreter/bytecode-generator.h b/chromium/v8/src/interpreter/bytecode-generator.h
index 69d5bf89576..f3b048d52d2 100644
--- a/chromium/v8/src/interpreter/bytecode-generator.h
+++ b/chromium/v8/src/interpreter/bytecode-generator.h
@@ -37,11 +37,11 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
       std::vector<FunctionLiteral*>* eager_inner_literals);
 
   void GenerateBytecode(uintptr_t stack_limit);
-  template <typename LocalIsolate>
-  Handle<BytecodeArray> FinalizeBytecode(LocalIsolate* isolate,
+  template <typename IsolateT>
+  Handle<BytecodeArray> FinalizeBytecode(IsolateT* isolate,
                                          Handle<Script> script);
-  template <typename LocalIsolate>
-  Handle<ByteArray> FinalizeSourcePositionTable(LocalIsolate* isolate);
+  template <typename IsolateT>
+  Handle<ByteArray> FinalizeSourcePositionTable(IsolateT* isolate);
 
 #ifdef DEBUG
   int CheckBytecodeMatches(BytecodeArray bytecode);
@@ -165,8 +165,8 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
   };
 
   void GenerateBytecodeBody();
-  template <typename LocalIsolate>
-  void AllocateDeferredConstants(LocalIsolate* isolate, Handle<Script> script);
+  template <typename IsolateT>
+  void AllocateDeferredConstants(IsolateT* isolate, Handle<Script> script);
 
   DEFINE_AST_VISITOR_SUBCLASS_MEMBERS();
 
@@ -243,10 +243,10 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
                                const AstRawString* name);
 
   void BuildVariableLoad(Variable* variable, HoleCheckMode hole_check_mode,
-                         TypeofMode typeof_mode = NOT_INSIDE_TYPEOF);
+                         TypeofMode typeof_mode = TypeofMode::kNotInside);
   void BuildVariableLoadForAccumulatorValue(
       Variable* variable, HoleCheckMode hole_check_mode,
-      TypeofMode typeof_mode = NOT_INSIDE_TYPEOF);
+      TypeofMode typeof_mode = TypeofMode::kNotInside);
   void BuildVariableAssignment(
       Variable* variable, Token::Value op, HoleCheckMode hole_check_mode,
       LookupHoistingMode lookup_hoisting_mode = LookupHoistingMode::kNormal);
diff --git a/chromium/v8/src/interpreter/bytecode-operands.h b/chromium/v8/src/interpreter/bytecode-operands.h
index c9cca226abb..4032980fe8a 100644
--- a/chromium/v8/src/interpreter/bytecode-operands.h
+++ b/chromium/v8/src/interpreter/bytecode-operands.h
@@ -151,7 +151,6 @@ class BytecodeOperands : public AllStatic {
 #undef OPERAND_SCALE_COUNT
 
   static constexpr int OperandScaleAsIndex(OperandScale operand_scale) {
-#if V8_HAS_CXX14_CONSTEXPR
 #ifdef DEBUG
     int result = static_cast<int>(operand_scale) >> 1;
     switch (operand_scale) {
@@ -168,7 +167,6 @@ class BytecodeOperands : public AllStatic {
         UNREACHABLE();
     }
 #endif
-#endif
     return static_cast<int>(operand_scale) >> 1;
   }
 
diff --git a/chromium/v8/src/interpreter/bytecodes.h b/chromium/v8/src/interpreter/bytecodes.h
index 56d9d5af0d1..e4589918b69 100644
--- a/chromium/v8/src/interpreter/bytecodes.h
+++ b/chromium/v8/src/interpreter/bytecodes.h
@@ -68,7 +68,9 @@ namespace interpreter {
     OperandType::kRuntimeId, OperandType::kReg, OperandType::kReg,             \
     OperandType::kReg)                                                         \
                                                                                \
-  /* Loading the accumulator */                                                \
+  /* Side-effect-free bytecodes -- carefully ordered for efficient checks */   \
+  /* - [Loading the accumulator] */                                            \
+  V(Ldar, ImplicitRegisterUse::kWriteAccumulator, OperandType::kReg)           \
   V(LdaZero, ImplicitRegisterUse::kWriteAccumulator)                           \
   V(LdaSmi, ImplicitRegisterUse::kWriteAccumulator, OperandType::kImm)         \
   V(LdaUndefined, ImplicitRegisterUse::kWriteAccumulator)                      \
@@ -77,6 +79,27 @@ namespace interpreter {
   V(LdaTrue, ImplicitRegisterUse::kWriteAccumulator)                           \
   V(LdaFalse, ImplicitRegisterUse::kWriteAccumulator)                          \
   V(LdaConstant, ImplicitRegisterUse::kWriteAccumulator, OperandType::kIdx)    \
+  V(LdaContextSlot, ImplicitRegisterUse::kWriteAccumulator, OperandType::kReg, \
+    OperandType::kIdx, OperandType::kUImm)                                     \
+  V(LdaImmutableContextSlot, ImplicitRegisterUse::kWriteAccumulator,           \
+    OperandType::kReg, OperandType::kIdx, OperandType::kUImm)                  \
+  V(LdaCurrentContextSlot, ImplicitRegisterUse::kWriteAccumulator,             \
+    OperandType::kIdx)                                                         \
+  V(LdaImmutableCurrentContextSlot, ImplicitRegisterUse::kWriteAccumulator,    \
+    OperandType::kIdx)                                                         \
+  /* - [Register Loads ] */                                                    \
+  V(Star, ImplicitRegisterUse::kReadAccumulator, OperandType::kRegOut)         \
+  V(Mov, ImplicitRegisterUse::kNone, OperandType::kReg, OperandType::kRegOut)  \
+  V(PushContext, ImplicitRegisterUse::kReadAccumulator, OperandType::kRegOut)  \
+  V(PopContext, ImplicitRegisterUse::kNone, OperandType::kReg)                 \
+  /* - [Test Operations ] */                                                   \
+  V(TestReferenceEqual, ImplicitRegisterUse::kReadWriteAccumulator,            \
+    OperandType::kReg)                                                         \
+  V(TestUndetectable, ImplicitRegisterUse::kReadWriteAccumulator)              \
+  V(TestNull, ImplicitRegisterUse::kReadWriteAccumulator)                      \
+  V(TestUndefined, ImplicitRegisterUse::kReadWriteAccumulator)                 \
+  V(TestTypeOf, ImplicitRegisterUse::kReadWriteAccumulator,                    \
+    OperandType::kFlag8)                                                       \
                                                                                \
   /* Globals */                                                                \
   V(LdaGlobal, ImplicitRegisterUse::kWriteAccumulator, OperandType::kIdx,      \
@@ -87,16 +110,6 @@ namespace interpreter {
     OperandType::kIdx)                                                         \
                                                                                \
   /* Context operations */                                                     \
-  V(PushContext, ImplicitRegisterUse::kReadAccumulator, OperandType::kRegOut)  \
-  V(PopContext, ImplicitRegisterUse::kNone, OperandType::kReg)                 \
-  V(LdaContextSlot, ImplicitRegisterUse::kWriteAccumulator, OperandType::kReg, \
-    OperandType::kIdx, OperandType::kUImm)                                     \
-  V(LdaImmutableContextSlot, ImplicitRegisterUse::kWriteAccumulator,           \
-    OperandType::kReg, OperandType::kIdx, OperandType::kUImm)                  \
-  V(LdaCurrentContextSlot, ImplicitRegisterUse::kWriteAccumulator,             \
-    OperandType::kIdx)                                                         \
-  V(LdaImmutableCurrentContextSlot, ImplicitRegisterUse::kWriteAccumulator,    \
-    OperandType::kIdx)                                                         \
   V(StaContextSlot, ImplicitRegisterUse::kReadAccumulator, OperandType::kReg,  \
     OperandType::kIdx, OperandType::kUImm)                                     \
   V(StaCurrentContextSlot, ImplicitRegisterUse::kReadAccumulator,              \
@@ -117,13 +130,6 @@ namespace interpreter {
   V(StaLookupSlot, ImplicitRegisterUse::kReadWriteAccumulator,                 \
     OperandType::kIdx, OperandType::kFlag8)                                    \
                                                                                \
-  /* Register-accumulator transfers */                                         \
-  V(Ldar, ImplicitRegisterUse::kWriteAccumulator, OperandType::kReg)           \
-  V(Star, ImplicitRegisterUse::kReadAccumulator, OperandType::kRegOut)         \
-                                                                               \
-  /* Register-register transfers */                                            \
-  V(Mov, ImplicitRegisterUse::kNone, OperandType::kReg, OperandType::kRegOut)  \
-                                                                               \
   /* Property loads (LoadIC) operations */                                     \
   V(LdaNamedProperty, ImplicitRegisterUse::kWriteAccumulator,                  \
     OperandType::kReg, OperandType::kIdx, OperandType::kIdx)                   \
@@ -272,7 +278,7 @@ namespace interpreter {
     OperandType::kReg, OperandType::kRegList, OperandType::kRegCount,          \
     OperandType::kIdx)                                                         \
                                                                                \
-  /* Test Operators */                                                         \
+  /* Effectful Test Operators */                                               \
   V(TestEqual, ImplicitRegisterUse::kReadWriteAccumulator, OperandType::kReg,  \
     OperandType::kIdx)                                                         \
   V(TestEqualStrict, ImplicitRegisterUse::kReadWriteAccumulator,               \
@@ -285,17 +291,10 @@ namespace interpreter {
     OperandType::kReg, OperandType::kIdx)                                      \
   V(TestGreaterThanOrEqual, ImplicitRegisterUse::kReadWriteAccumulator,        \
     OperandType::kReg, OperandType::kIdx)                                      \
-  V(TestReferenceEqual, ImplicitRegisterUse::kReadWriteAccumulator,            \
-    OperandType::kReg)                                                         \
   V(TestInstanceOf, ImplicitRegisterUse::kReadWriteAccumulator,                \
     OperandType::kReg, OperandType::kIdx)                                      \
   V(TestIn, ImplicitRegisterUse::kReadWriteAccumulator, OperandType::kReg,     \
     OperandType::kIdx)                                                         \
-  V(TestUndetectable, ImplicitRegisterUse::kReadWriteAccumulator)              \
-  V(TestNull, ImplicitRegisterUse::kReadWriteAccumulator)                      \
-  V(TestUndefined, ImplicitRegisterUse::kReadWriteAccumulator)                 \
-  V(TestTypeOf, ImplicitRegisterUse::kReadWriteAccumulator,                    \
-    OperandType::kFlag8)                                                       \
                                                                                \
   /* Cast operators */                                                         \
   V(ToName, ImplicitRegisterUse::kReadAccumulator, OperandType::kRegOut)       \
@@ -650,25 +649,17 @@ class V8_EXPORT_PRIVATE Bytecodes final : public AllStatic {
   // Return true if |bytecode| is an accumulator load without effects,
   // e.g. LdaConstant, LdaTrue, Ldar.
   static constexpr bool IsAccumulatorLoadWithoutEffects(Bytecode bytecode) {
-    return bytecode == Bytecode::kLdar || bytecode == Bytecode::kLdaZero ||
-           bytecode == Bytecode::kLdaSmi || bytecode == Bytecode::kLdaNull ||
-           bytecode == Bytecode::kLdaTrue || bytecode == Bytecode::kLdaFalse ||
-           bytecode == Bytecode::kLdaUndefined ||
-           bytecode == Bytecode::kLdaTheHole ||
-           bytecode == Bytecode::kLdaConstant ||
-           bytecode == Bytecode::kLdaContextSlot ||
-           bytecode == Bytecode::kLdaCurrentContextSlot ||
-           bytecode == Bytecode::kLdaImmutableContextSlot ||
-           bytecode == Bytecode::kLdaImmutableCurrentContextSlot;
+    STATIC_ASSERT(Bytecode::kLdar < Bytecode::kLdaImmutableCurrentContextSlot);
+    return bytecode >= Bytecode::kLdar &&
+           bytecode <= Bytecode::kLdaImmutableCurrentContextSlot;
   }
 
   // Returns true if |bytecode| is a compare operation without external effects
   // (e.g., Type cooersion).
   static constexpr bool IsCompareWithoutEffects(Bytecode bytecode) {
-    return bytecode == Bytecode::kTestUndetectable ||
-           bytecode == Bytecode::kTestNull ||
-           bytecode == Bytecode::kTestUndefined ||
-           bytecode == Bytecode::kTestTypeOf;
+    STATIC_ASSERT(Bytecode::kTestReferenceEqual < Bytecode::kTestTypeOf);
+    return bytecode >= Bytecode::kTestReferenceEqual &&
+           bytecode <= Bytecode::kTestTypeOf;
   }
 
   static constexpr bool IsShortStar(Bytecode bytecode) {
@@ -683,8 +674,8 @@ class V8_EXPORT_PRIVATE Bytecodes final : public AllStatic {
   // Return true if |bytecode| is a register load without effects,
   // e.g. Mov, Star.
   static constexpr bool IsRegisterLoadWithoutEffects(Bytecode bytecode) {
-    return bytecode == Bytecode::kMov || bytecode == Bytecode::kPopContext ||
-           bytecode == Bytecode::kPushContext || IsAnyStar(bytecode);
+    return IsShortStar(bytecode) ||
+           (bytecode >= Bytecode::kStar && bytecode <= Bytecode::kPopContext);
   }
 
   // Returns true if the bytecode is a conditional jump taking
diff --git a/chromium/v8/src/interpreter/constant-array-builder.cc b/chromium/v8/src/interpreter/constant-array-builder.cc
index 4142d3a7cac..260a75448d9 100644
--- a/chromium/v8/src/interpreter/constant-array-builder.cc
+++ b/chromium/v8/src/interpreter/constant-array-builder.cc
@@ -65,9 +65,9 @@ const ConstantArrayBuilder::Entry& ConstantArrayBuilder::ConstantArraySlice::At(
 }
 
 #if DEBUG
-template <typename LocalIsolate>
+template <typename IsolateT>
 void ConstantArrayBuilder::ConstantArraySlice::CheckAllElementsAreUnique(
-    LocalIsolate* isolate) const {
+    IsolateT* isolate) const {
   std::set<Smi> smis;
   std::set<double> heap_numbers;
   std::set<const AstRawString*> strings;
@@ -164,9 +164,9 @@ ConstantArrayBuilder::ConstantArraySlice* ConstantArrayBuilder::IndexToSlice(
   UNREACHABLE();
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 MaybeHandle<Object> ConstantArrayBuilder::At(size_t index,
-                                             LocalIsolate* isolate) const {
+                                             IsolateT* isolate) const {
   const ConstantArraySlice* slice = IndexToSlice(index);
   DCHECK_LT(index, slice->capacity());
   if (index < slice->start_index() + slice->size()) {
@@ -183,8 +183,8 @@ template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
     MaybeHandle<Object> ConstantArrayBuilder::At(size_t index,
                                                  LocalIsolate* isolate) const;
 
-template <typename LocalIsolate>
-Handle<FixedArray> ConstantArrayBuilder::ToFixedArray(LocalIsolate* isolate) {
+template <typename IsolateT>
+Handle<FixedArray> ConstantArrayBuilder::ToFixedArray(IsolateT* isolate) {
   Handle<FixedArray> fixed_array = isolate->factory()->NewFixedArrayWithHoles(
       static_cast<int>(size()), AllocationType::kOld);
   int array_index = 0;
@@ -372,9 +372,8 @@ void ConstantArrayBuilder::DiscardReservedEntry(OperandSize operand_size) {
   OperandSizeToSlice(operand_size)->Unreserve();
 }
 
-template <typename LocalIsolate>
-Handle<Object> ConstantArrayBuilder::Entry::ToHandle(
-    LocalIsolate* isolate) const {
+template <typename IsolateT>
+Handle<Object> ConstantArrayBuilder::Entry::ToHandle(IsolateT* isolate) const {
   switch (tag_) {
     case Tag::kDeferred:
       // We shouldn't have any deferred entries by now.
diff --git a/chromium/v8/src/interpreter/constant-array-builder.h b/chromium/v8/src/interpreter/constant-array-builder.h
index b17995f0a16..2120142a12b 100644
--- a/chromium/v8/src/interpreter/constant-array-builder.h
+++ b/chromium/v8/src/interpreter/constant-array-builder.h
@@ -52,16 +52,16 @@ class V8_EXPORT_PRIVATE ConstantArrayBuilder final {
   explicit ConstantArrayBuilder(Zone* zone);
 
   // Generate a fixed array of constant handles based on inserted objects.
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-  Handle<FixedArray> ToFixedArray(LocalIsolate* isolate);
+  Handle<FixedArray> ToFixedArray(IsolateT* isolate);
 
   // Returns the object, as a handle in |isolate|, that is in the constant pool
   // array at index |index|. Returns null if there is no handle at this index.
   // Only expected to be used in tests.
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-  MaybeHandle<Object> At(size_t index, LocalIsolate* isolate) const;
+  MaybeHandle<Object> At(size_t index, IsolateT* isolate) const;
 
   // Returns the number of elements in the array.
   size_t size() const;
@@ -154,8 +154,8 @@ class V8_EXPORT_PRIVATE ConstantArrayBuilder final {
       smi_ = smi;
     }
 
-    template <typename LocalIsolate>
-    Handle<Object> ToHandle(LocalIsolate* isolate) const;
+    template <typename IsolateT>
+    Handle<Object> ToHandle(IsolateT* isolate) const;
 
    private:
     explicit Entry(Tag tag) : tag_(tag) {}
@@ -207,8 +207,8 @@ class V8_EXPORT_PRIVATE ConstantArrayBuilder final {
     const Entry& At(size_t index) const;
 
 #if DEBUG
-    template <typename LocalIsolate>
-    void CheckAllElementsAreUnique(LocalIsolate* isolate) const;
+    template <typename IsolateT>
+    void CheckAllElementsAreUnique(IsolateT* isolate) const;
 #endif
 
     inline size_t available() const { return capacity() - reserved() - size(); }
diff --git a/chromium/v8/src/interpreter/handler-table-builder.cc b/chromium/v8/src/interpreter/handler-table-builder.cc
index 56f5b849dc6..1a88b2ab073 100644
--- a/chromium/v8/src/interpreter/handler-table-builder.cc
+++ b/chromium/v8/src/interpreter/handler-table-builder.cc
@@ -15,8 +15,8 @@ namespace interpreter {
 
 HandlerTableBuilder::HandlerTableBuilder(Zone* zone) : entries_(zone) {}
 
-template <typename LocalIsolate>
-Handle<ByteArray> HandlerTableBuilder::ToHandlerTable(LocalIsolate* isolate) {
+template <typename IsolateT>
+Handle<ByteArray> HandlerTableBuilder::ToHandlerTable(IsolateT* isolate) {
   int handler_table_size = static_cast<int>(entries_.size());
   Handle<ByteArray> table_byte_array = isolate->factory()->NewByteArray(
       HandlerTable::LengthForRange(handler_table_size), AllocationType::kOld);
diff --git a/chromium/v8/src/interpreter/handler-table-builder.h b/chromium/v8/src/interpreter/handler-table-builder.h
index f5f264d7c7e..8670fc04924 100644
--- a/chromium/v8/src/interpreter/handler-table-builder.h
+++ b/chromium/v8/src/interpreter/handler-table-builder.h
@@ -30,8 +30,8 @@ class V8_EXPORT_PRIVATE HandlerTableBuilder final {
 
   // Builds the actual handler table by copying the current values into a heap
   // object. Any further mutations to the builder won't be reflected.
-  template <typename LocalIsolate>
-  Handle<ByteArray> ToHandlerTable(LocalIsolate* isolate);
+  template <typename IsolateT>
+  Handle<ByteArray> ToHandlerTable(IsolateT* isolate);
 
   // Creates a new handler table entry and returns a {hander_id} identifying the
   // entry, so that it can be referenced by below setter functions.
diff --git a/chromium/v8/src/interpreter/interpreter-assembler.cc b/chromium/v8/src/interpreter/interpreter-assembler.cc
index df5b525877d..f6733def8e6 100644
--- a/chromium/v8/src/interpreter/interpreter-assembler.cc
+++ b/chromium/v8/src/interpreter/interpreter-assembler.cc
@@ -8,7 +8,7 @@
 #include <ostream>
 
 #include "src/codegen/code-factory.h"
-#include "src/codegen/interface-descriptors.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/machine-type.h"
 #include "src/execution/frames.h"
 #include "src/interpreter/bytecodes.h"
@@ -803,7 +803,9 @@ void InterpreterAssembler::CallJSWithSpreadAndDispatch(
     TNode<UintPtrT> slot_id, TNode<HeapObject> maybe_feedback_vector) {
   DCHECK(Bytecodes::MakesCallAlongCriticalPath(bytecode_));
   DCHECK_EQ(Bytecodes::GetReceiverMode(bytecode_), ConvertReceiverMode::kAny);
-  CollectCallFeedback(function, context, maybe_feedback_vector, slot_id);
+  LazyNode<Object> receiver = [=] { return LoadRegisterAtOperandIndex(1); };
+  CollectCallFeedback(function, receiver, context, maybe_feedback_vector,
+                      slot_id);
   Comment("call using CallWithSpread builtin");
   Callable callable = CodeFactory::InterpreterPushArgsThenCall(
       isolate(), ConvertReceiverMode::kAny,
@@ -1310,26 +1312,6 @@ void InterpreterAssembler::AbortIfWordNotEqual(TNode<WordT> lhs,
   BIND(&ok);
 }
 
-void InterpreterAssembler::MaybeDropFrames(TNode<Context> context) {
-  TNode<ExternalReference> restart_fp_address =
-      ExternalConstant(ExternalReference::debug_restart_fp_address(isolate()));
-
-  TNode<IntPtrT> restart_fp = Load<IntPtrT>(restart_fp_address);
-  TNode<IntPtrT> null = IntPtrConstant(0);
-
-  Label ok(this), drop_frames(this);
-  Branch(IntPtrEqual(restart_fp, null), &ok, &drop_frames);
-
-  BIND(&drop_frames);
-  // We don't expect this call to return since the frame dropper tears down
-  // the stack and jumps into the function on the target frame to restart it.
-  CallStub(CodeFactory::FrameDropperTrampoline(isolate()), context, restart_fp);
-  Abort(AbortReason::kUnexpectedReturnFromFrameDropper);
-  Goto(&ok);
-
-  BIND(&ok);
-}
-
 void InterpreterAssembler::OnStackReplacement(TNode<Context> context,
                                               TNode<IntPtrT> relative_jump) {
   TNode<JSFunction> function = CAST(LoadRegister(Register::function_closure()));
diff --git a/chromium/v8/src/interpreter/interpreter-assembler.h b/chromium/v8/src/interpreter/interpreter-assembler.h
index 019fd40f3bf..bf4641200bb 100644
--- a/chromium/v8/src/interpreter/interpreter-assembler.h
+++ b/chromium/v8/src/interpreter/interpreter-assembler.h
@@ -241,9 +241,6 @@ class V8_EXPORT_PRIVATE InterpreterAssembler : public CodeStubAssembler {
       TNode<FixedArrayBase> parameters_and_registers,
       TNode<IntPtrT> formal_parameter_count, TNode<UintPtrT> register_count);
 
-  // Dispatch to frame dropper trampoline if necessary.
-  void MaybeDropFrames(TNode<Context> context);
-
   // Perform OnStackReplacement.
   void OnStackReplacement(TNode<Context> context, TNode<IntPtrT> relative_jump);
 
diff --git a/chromium/v8/src/interpreter/interpreter-generator.cc b/chromium/v8/src/interpreter/interpreter-generator.cc
index cb01348a351..75027b96b7d 100644
--- a/chromium/v8/src/interpreter/interpreter-generator.cc
+++ b/chromium/v8/src/interpreter/interpreter-generator.cc
@@ -209,7 +209,7 @@ IGNITION_HANDLER(LdaGlobal, InterpreterLoadGlobalAssembler) {
   static const int kNameOperandIndex = 0;
   static const int kSlotOperandIndex = 1;
 
-  LdaGlobal(kSlotOperandIndex, kNameOperandIndex, NOT_INSIDE_TYPEOF);
+  LdaGlobal(kSlotOperandIndex, kNameOperandIndex, TypeofMode::kNotInside);
 }
 
 // LdaGlobalInsideTypeof <name_index> <slot>
@@ -220,7 +220,7 @@ IGNITION_HANDLER(LdaGlobalInsideTypeof, InterpreterLoadGlobalAssembler) {
   static const int kNameOperandIndex = 0;
   static const int kSlotOperandIndex = 1;
 
-  LdaGlobal(kSlotOperandIndex, kNameOperandIndex, INSIDE_TYPEOF);
+  LdaGlobal(kSlotOperandIndex, kNameOperandIndex, TypeofMode::kInside);
 }
 
 // StaGlobal <name_index> <slot>
@@ -418,8 +418,8 @@ class InterpreterLookupGlobalAssembler : public InterpreterLoadGlobalAssembler {
 
       TypeofMode typeof_mode =
           function_id == Runtime::kLoadLookupSlotInsideTypeof
-              ? INSIDE_TYPEOF
-              : NOT_INSIDE_TYPEOF;
+              ? TypeofMode::kInside
+              : TypeofMode::kNotInside;
 
       LdaGlobal(kSlotOperandIndex, kNameOperandIndex, typeof_mode);
     }
@@ -1365,13 +1365,19 @@ class InterpreterJSCallAssembler : public InterpreterAssembler {
   // Generates code to perform a JS call that collects type feedback.
   void JSCall(ConvertReceiverMode receiver_mode) {
     TNode<Object> function = LoadRegisterAtOperandIndex(0);
+    LazyNode<Object> receiver = [=] {
+      return receiver_mode == ConvertReceiverMode::kNullOrUndefined
+                 ? UndefinedConstant()
+                 : LoadRegisterAtOperandIndex(1);
+    };
     RegListNodePair args = GetRegisterListAtOperandIndex(1);
     TNode<UintPtrT> slot_id = BytecodeOperandIdx(3);
     TNode<HeapObject> maybe_feedback_vector = LoadFeedbackVector();
     TNode<Context> context = GetContext();
 
     // Collect the {function} feedback.
-    CollectCallFeedback(function, context, maybe_feedback_vector, slot_id);
+    CollectCallFeedback(function, receiver, context, maybe_feedback_vector,
+                        slot_id);
 
     // Call the function and dispatch to the next handler.
     CallJSAndDispatch(function, context, args, receiver_mode);
@@ -1399,12 +1405,18 @@ class InterpreterJSCallAssembler : public InterpreterAssembler {
         kFirstArgumentOperandIndex + kReceiverAndArgOperandCount;
 
     TNode<Object> function = LoadRegisterAtOperandIndex(0);
+    LazyNode<Object> receiver = [=] {
+      return receiver_mode == ConvertReceiverMode::kNullOrUndefined
+                 ? UndefinedConstant()
+                 : LoadRegisterAtOperandIndex(1);
+    };
     TNode<UintPtrT> slot_id = BytecodeOperandIdx(kSlotOperandIndex);
     TNode<HeapObject> maybe_feedback_vector = LoadFeedbackVector();
     TNode<Context> context = GetContext();
 
     // Collect the {function} feedback.
-    CollectCallFeedback(function, context, maybe_feedback_vector, slot_id);
+    CollectCallFeedback(function, receiver, context, maybe_feedback_vector,
+                        slot_id);
 
     switch (kReceiverAndArgOperandCount) {
       case 0:
@@ -2776,7 +2788,7 @@ IGNITION_HANDLER(ThrowIfNotSuperConstructor, InterpreterAssembler) {
 // Call runtime to handle debugger statement.
 IGNITION_HANDLER(Debugger, InterpreterAssembler) {
   TNode<Context> context = GetContext();
-  CallStub(CodeFactory::HandleDebuggerStatement(isolate()), context);
+  CallRuntime(Runtime::kHandleDebuggerStatement, context);
   Dispatch();
 }
 
@@ -2791,7 +2803,6 @@ IGNITION_HANDLER(Debugger, InterpreterAssembler) {
         Runtime::kDebugBreakOnBytecode, context, accumulator);               \
     TNode<Object> return_value = Projection<0>(result_pair);                 \
     TNode<IntPtrT> original_bytecode = SmiUntag(Projection<1>(result_pair)); \
-    MaybeDropFrames(context);                                                \
     SetAccumulator(return_value);                                            \
     DispatchToBytecodeWithOptionalStarLookahead(original_bytecode);          \
   }
diff --git a/chromium/v8/src/interpreter/interpreter-intrinsics-generator.cc b/chromium/v8/src/interpreter/interpreter-intrinsics-generator.cc
index b6ea44f6e73..c98f78f8788 100644
--- a/chromium/v8/src/interpreter/interpreter-intrinsics-generator.cc
+++ b/chromium/v8/src/interpreter/interpreter-intrinsics-generator.cc
@@ -213,12 +213,6 @@ TNode<Object> IntrinsicsGenerator::HasProperty(
                                 arg_count);
 }
 
-TNode<Object> IntrinsicsGenerator::ToString(
-    const InterpreterAssembler::RegListNodePair& args, TNode<Context> context,
-    int arg_count) {
-  return IntrinsicAsBuiltinCall(args, context, Builtins::kToString, arg_count);
-}
-
 TNode<Object> IntrinsicsGenerator::ToLength(
     const InterpreterAssembler::RegListNodePair& args, TNode<Context> context,
     int arg_count) {
diff --git a/chromium/v8/src/interpreter/interpreter-intrinsics.h b/chromium/v8/src/interpreter/interpreter-intrinsics.h
index 07c60270c2a..85c54f67f11 100644
--- a/chromium/v8/src/interpreter/interpreter-intrinsics.h
+++ b/chromium/v8/src/interpreter/interpreter-intrinsics.h
@@ -36,7 +36,6 @@ namespace interpreter {
   V(IsArray, is_array, 1)                                            \
   V(IsJSReceiver, is_js_receiver, 1)                                 \
   V(IsSmi, is_smi, 1)                                                \
-  V(ToString, to_string, 1)                                          \
   V(ToLength, to_length, 1)                                          \
   V(ToObject, to_object, 1)
 
diff --git a/chromium/v8/src/interpreter/interpreter.cc b/chromium/v8/src/interpreter/interpreter.cc
index ddce0f0e4eb..36f2c546146 100644
--- a/chromium/v8/src/interpreter/interpreter.cc
+++ b/chromium/v8/src/interpreter/interpreter.cc
@@ -18,7 +18,6 @@
 #include "src/init/setup-isolate.h"
 #include "src/interpreter/bytecode-generator.h"
 #include "src/interpreter/bytecodes.h"
-#include "src/logging/counters-inl.h"
 #include "src/objects/objects-inl.h"
 #include "src/objects/shared-function-info.h"
 #include "src/objects/slots.h"
@@ -50,14 +49,13 @@ class InterpreterCompilationJob final : public UnoptimizedCompilationJob {
 
  private:
   BytecodeGenerator* generator() { return &generator_; }
-  template <typename LocalIsolate>
-  void CheckAndPrintBytecodeMismatch(LocalIsolate* isolate,
-                                     Handle<Script> script,
+  template <typename IsolateT>
+  void CheckAndPrintBytecodeMismatch(IsolateT* isolate, Handle<Script> script,
                                      Handle<BytecodeArray> bytecode);
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   Status DoFinalizeJobImpl(Handle<SharedFunctionInfo> shared_info,
-                           LocalIsolate* isolate);
+                           IsolateT* isolate);
 
   Zone zone_;
   UnoptimizedCompilationInfo compilation_info_;
@@ -177,10 +175,9 @@ InterpreterCompilationJob::InterpreterCompilationJob(
                  eager_inner_literals) {}
 
 InterpreterCompilationJob::Status InterpreterCompilationJob::ExecuteJobImpl() {
-  RuntimeCallTimerScope runtimeTimerScope(
-      parse_info()->runtime_call_stats(),
-      RuntimeCallCounterId::kCompileIgnition,
-      RuntimeCallStats::kThreadSpecific);
+  RCS_SCOPE(parse_info()->runtime_call_stats(),
+            RuntimeCallCounterId::kCompileIgnition,
+            RuntimeCallStats::kThreadSpecific);
   // TODO(lpy): add support for background compilation RCS trace.
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.CompileIgnition");
 
@@ -203,10 +200,9 @@ InterpreterCompilationJob::Status InterpreterCompilationJob::ExecuteJobImpl() {
 }
 
 #ifdef DEBUG
-template <typename LocalIsolate>
+template <typename IsolateT>
 void InterpreterCompilationJob::CheckAndPrintBytecodeMismatch(
-    LocalIsolate* isolate, Handle<Script> script,
-    Handle<BytecodeArray> bytecode) {
+    IsolateT* isolate, Handle<Script> script, Handle<BytecodeArray> bytecode) {
   int first_mismatch = generator()->CheckBytecodeMatches(*bytecode);
   if (first_mismatch >= 0) {
     parse_info()->ast_value_factory()->Internalize(isolate);
@@ -243,9 +239,8 @@ void InterpreterCompilationJob::CheckAndPrintBytecodeMismatch(
 
 InterpreterCompilationJob::Status InterpreterCompilationJob::FinalizeJobImpl(
     Handle<SharedFunctionInfo> shared_info, Isolate* isolate) {
-  RuntimeCallTimerScope runtimeTimerScope(
-      parse_info()->runtime_call_stats(),
-      RuntimeCallCounterId::kCompileIgnitionFinalization);
+  RCS_SCOPE(parse_info()->runtime_call_stats(),
+            RuntimeCallCounterId::kCompileIgnitionFinalization);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                "V8.CompileIgnitionFinalization");
   return DoFinalizeJobImpl(shared_info, isolate);
@@ -253,17 +248,16 @@ InterpreterCompilationJob::Status InterpreterCompilationJob::FinalizeJobImpl(
 
 InterpreterCompilationJob::Status InterpreterCompilationJob::FinalizeJobImpl(
     Handle<SharedFunctionInfo> shared_info, LocalIsolate* isolate) {
-  RuntimeCallTimerScope runtimeTimerScope(
-      parse_info()->runtime_call_stats(),
-      RuntimeCallCounterId::kCompileBackgroundIgnitionFinalization);
+  RCS_SCOPE(parse_info()->runtime_call_stats(),
+            RuntimeCallCounterId::kCompileBackgroundIgnitionFinalization);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                "V8.CompileIgnitionFinalization");
   return DoFinalizeJobImpl(shared_info, isolate);
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 InterpreterCompilationJob::Status InterpreterCompilationJob::DoFinalizeJobImpl(
-    Handle<SharedFunctionInfo> shared_info, LocalIsolate* isolate) {
+    Handle<SharedFunctionInfo> shared_info, IsolateT* isolate) {
   Handle<BytecodeArray> bytecodes = compilation_info_.bytecode_array();
   if (bytecodes.is_null()) {
     bytecodes = generator()->FinalizeBytecode(
diff --git a/chromium/v8/src/json/json-parser.cc b/chromium/v8/src/json/json-parser.cc
index ccea49e89fa..7d350d02e54 100644
--- a/chromium/v8/src/json/json-parser.cc
+++ b/chromium/v8/src/json/json-parser.cc
@@ -10,6 +10,7 @@
 #include "src/numbers/hash-seed-inl.h"
 #include "src/objects/field-type.h"
 #include "src/objects/hash-table-inl.h"
+#include "src/objects/map-updater.h"
 #include "src/objects/objects-inl.h"
 #include "src/objects/property-descriptor.h"
 #include "src/strings/char-predicates-inl.h"
@@ -509,17 +510,18 @@ Handle<Object> JsonParser<Char>::BuildJsonObject(
       }
       Handle<FieldType> value_type =
           value->OptimalType(isolate(), representation);
-      Map::GeneralizeField(isolate(), target, descriptor_index,
-                           details.constness(), representation, value_type);
+      MapUpdater::GeneralizeField(isolate(), target, descriptor_index,
+                                  details.constness(), representation,
+                                  value_type);
     } else if (expected_representation.IsHeapObject() &&
                !target->instance_descriptors(isolate())
                     .GetFieldType(descriptor_index)
                     .NowContains(value)) {
       Handle<FieldType> value_type =
           value->OptimalType(isolate(), expected_representation);
-      Map::GeneralizeField(isolate(), target, descriptor_index,
-                           details.constness(), expected_representation,
-                           value_type);
+      MapUpdater::GeneralizeField(isolate(), target, descriptor_index,
+                                  details.constness(), expected_representation,
+                                  value_type);
     } else if (expected_representation.IsDouble() && value->IsSmi()) {
       new_mutable_double++;
     }
@@ -601,8 +603,8 @@ Handle<Object> JsonParser<Char>::BuildJsonObject(
           mutable_double_address += kMutableDoubleSize;
         } else {
           DCHECK(value.IsHeapNumber());
-          HeapObject::cast(value).synchronized_set_map(
-              *factory()->heap_number_map());
+          HeapObject::cast(value).set_map(*factory()->heap_number_map(),
+                                          kReleaseStore);
         }
       }
       object->RawFastInobjectPropertyAtPut(index, value, mode);
diff --git a/chromium/v8/src/libplatform/tracing/recorder-default.cc b/chromium/v8/src/libplatform/tracing/recorder-default.cc
deleted file mode 100644
index 46e0cbb8e26..00000000000
--- a/chromium/v8/src/libplatform/tracing/recorder-default.cc
+++ /dev/null
@@ -1,25 +0,0 @@
-// Copyright 2020 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-#ifndef V8_LIBPLATFORM_TRACING_RECORDER_DEFAULT_H_
-#define V8_LIBPLATFORM_TRACING_RECORDER_DEFAULT_H_
-
-#include "src/libplatform/tracing/recorder.h"
-
-namespace v8 {
-namespace platform {
-namespace tracing {
-
-Recorder::Recorder() {}
-Recorder::~Recorder() {}
-
-bool Recorder::IsEnabled() { return false; }
-bool Recorder::IsEnabled(const uint8_t level) { return false; }
-
-void Recorder::AddEvent(TraceObject* trace_event) {}
-
-}  // namespace tracing
-}  // namespace platform
-}  // namespace v8
-
-#endif  // V8_LIBPLATFORM_TRACING_RECORDER_DEFAULT_H_
diff --git a/chromium/v8/src/libplatform/tracing/recorder-mac.cc b/chromium/v8/src/libplatform/tracing/recorder-mac.cc
new file mode 100644
index 00000000000..6a6689f8cf1
--- /dev/null
+++ b/chromium/v8/src/libplatform/tracing/recorder-mac.cc
@@ -0,0 +1,43 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+#ifndef V8_LIBPLATFORM_TRACING_RECORDER_MAC_H_
+#define V8_LIBPLATFORM_TRACING_RECORDER_MAC_H_
+
+#include "src/libplatform/tracing/recorder.h"
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunguarded-availability"
+
+namespace v8 {
+namespace platform {
+namespace tracing {
+
+Recorder::Recorder() { v8Provider = os_log_create("v8", ""); }
+Recorder::~Recorder() {}
+
+bool Recorder::IsEnabled() {
+  return os_log_type_enabled(v8Provider, OS_LOG_TYPE_DEFAULT);
+}
+bool Recorder::IsEnabled(const uint8_t level) {
+  if (level == OS_LOG_TYPE_DEFAULT || level == OS_LOG_TYPE_INFO ||
+      level == OS_LOG_TYPE_DEBUG || level == OS_LOG_TYPE_ERROR ||
+      level == OS_LOG_TYPE_FAULT) {
+    return os_log_type_enabled(v8Provider, static_cast<os_log_type_t>(level));
+  }
+  return false;
+}
+
+void Recorder::AddEvent(TraceObject* trace_event) {
+  os_signpost_event_emit(v8Provider, OS_SIGNPOST_ID_EXCLUSIVE, "",
+                         "%s, cpu_duration: %d", trace_event->name(),
+                         static_cast<int>(trace_event->cpu_duration()));
+}
+
+}  // namespace tracing
+}  // namespace platform
+}  // namespace v8
+
+#pragma clang diagnostic pop
+
+#endif  // V8_LIBPLATFORM_TRACING_RECORDER_MAC_H_
diff --git a/chromium/v8/src/libplatform/tracing/recorder.h b/chromium/v8/src/libplatform/tracing/recorder.h
index 31cc75f9bd8..8b8eb0e0e91 100644
--- a/chromium/v8/src/libplatform/tracing/recorder.h
+++ b/chromium/v8/src/libplatform/tracing/recorder.h
@@ -9,6 +9,16 @@
 
 #include "include/libplatform/v8-tracing.h"
 
+#if !defined(V8_ENABLE_SYSTEM_INSTRUMENTATION)
+#error "only include this file if V8_ENABLE_SYSTEM_INSTRUMENTATION"
+#endif
+
+#if V8_OS_MACOSX
+#include <os/signpost.h>
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunguarded-availability"
+#endif
+
 #if V8_OS_WIN
 #ifndef V8_ETW_GUID
 #define V8_ETW_GUID \
@@ -31,14 +41,23 @@ class V8_PLATFORM_EXPORT Recorder {
   Recorder();
   ~Recorder();
 
-  static bool IsEnabled();
-  static bool IsEnabled(const uint8_t level);
+  bool IsEnabled();
+  bool IsEnabled(const uint8_t level);
 
   void AddEvent(TraceObject* trace_event);
+
+ private:
+#if V8_OS_MACOSX
+  os_log_t v8Provider;
+#endif
 };
 
 }  // namespace tracing
 }  // namespace platform
 }  // namespace v8
 
+#if V8_OS_MACOSX
+#pragma clang diagnostic pop
+#endif
+
 #endif  // V8_LIBPLATFORM_TRACING_RECORDER_H_
diff --git a/chromium/v8/src/libplatform/tracing/trace-writer.cc b/chromium/v8/src/libplatform/tracing/trace-writer.cc
index 5740dabd8f2..1131522eec4 100644
--- a/chromium/v8/src/libplatform/tracing/trace-writer.cc
+++ b/chromium/v8/src/libplatform/tracing/trace-writer.cc
@@ -9,7 +9,10 @@
 #include "base/trace_event/common/trace_event_common.h"
 #include "include/v8-platform.h"
 #include "src/base/platform/platform.h"
+
+#if defined(V8_ENABLE_SYSTEM_INSTRUMENTATION)
 #include "src/libplatform/tracing/recorder.h"
+#endif
 
 namespace v8 {
 namespace platform {
@@ -191,6 +194,7 @@ TraceWriter* TraceWriter::CreateJSONTraceWriter(std::ostream& stream,
   return new JSONTraceWriter(stream, tag);
 }
 
+#if defined(V8_ENABLE_SYSTEM_INSTRUMENTATION)
 SystemInstrumentationTraceWriter::SystemInstrumentationTraceWriter() {
   recorder_ = std::make_unique<Recorder>();
 }
@@ -211,6 +215,7 @@ void SystemInstrumentationTraceWriter::Flush() {}
 TraceWriter* TraceWriter::CreateSystemInstrumentationTraceWriter() {
   return new SystemInstrumentationTraceWriter();
 }
+#endif
 
 }  // namespace tracing
 }  // namespace platform
diff --git a/chromium/v8/src/libplatform/tracing/trace-writer.h b/chromium/v8/src/libplatform/tracing/trace-writer.h
index 1f727b815a5..2fada451080 100644
--- a/chromium/v8/src/libplatform/tracing/trace-writer.h
+++ b/chromium/v8/src/libplatform/tracing/trace-writer.h
@@ -29,6 +29,7 @@ class JSONTraceWriter : public TraceWriter {
   bool append_comma_ = false;
 };
 
+#if defined(V8_ENABLE_SYSTEM_INSTRUMENTATION)
 class SystemInstrumentationTraceWriter : public TraceWriter {
  public:
   SystemInstrumentationTraceWriter();
@@ -39,6 +40,7 @@ class SystemInstrumentationTraceWriter : public TraceWriter {
  private:
   std::unique_ptr<Recorder> recorder_;
 };
+#endif
 
 }  // namespace tracing
 }  // namespace platform
diff --git a/chromium/v8/src/logging/code-events.h b/chromium/v8/src/logging/code-events.h
index c009ba0b15d..cda7c39fc7c 100644
--- a/chromium/v8/src/logging/code-events.h
+++ b/chromium/v8/src/logging/code-events.h
@@ -98,6 +98,7 @@ class CodeEventListener {
   // Not handlified as this happens during GC. No allocation allowed.
   virtual void CodeMoveEvent(AbstractCode from, AbstractCode to) = 0;
   virtual void SharedFunctionInfoMoveEvent(Address from, Address to) = 0;
+  virtual void NativeContextMoveEvent(Address from, Address to) = 0;
   virtual void CodeMovingGCEvent() = 0;
   virtual void CodeDisableOptEvent(Handle<AbstractCode> code,
                                    Handle<SharedFunctionInfo> shared) = 0;
@@ -217,6 +218,11 @@ class CodeEventDispatcher : public CodeEventListener {
       listener->SharedFunctionInfoMoveEvent(from, to);
     });
   }
+  void NativeContextMoveEvent(Address from, Address to) override {
+    DispatchEventToListeners([=](CodeEventListener* listener) {
+      listener->NativeContextMoveEvent(from, to);
+    });
+  }
   void CodeMovingGCEvent() override {
     DispatchEventToListeners(
         [](CodeEventListener* listener) { listener->CodeMovingGCEvent(); });
diff --git a/chromium/v8/src/logging/counters-definitions.h b/chromium/v8/src/logging/counters-definitions.h
index ffa9647719d..ebf6e3f430a 100644
--- a/chromium/v8/src/logging/counters-definitions.h
+++ b/chromium/v8/src/logging/counters-definitions.h
@@ -85,6 +85,11 @@ namespace internal {
   HR(wasm_modules_per_engine, V8.WasmModulesPerEngine, 1, 1024, 30)            \
   /* bailout reason if Liftoff failed, or {kSuccess} (per function) */         \
   HR(liftoff_bailout_reasons, V8.LiftoffBailoutReasons, 0, 20, 21)             \
+  /* support for PKEYs/PKU by testing result of pkey_alloc() */                \
+  /* TODO(chromium:1207318): Only values 0 and 1 are actually used, but 3 */   \
+  /* buckets needed until {BooleanHistogram} is supported in Chromium UMA. */  \
+  HR(wasm_memory_protection_keys_support, V8.WasmMemoryProtectionKeysSupport,  \
+     0, 2, 3)                                                                  \
   /* number of thrown exceptions per isolate */                                \
   HR(wasm_throw_count, V8.WasmThrowCount, 0, 100000, 30)                       \
   /* number of rethrown exceptions per isolate */                              \
diff --git a/chromium/v8/src/logging/counters-inl.h b/chromium/v8/src/logging/counters-inl.h
deleted file mode 100644
index 3e067c7c060..00000000000
--- a/chromium/v8/src/logging/counters-inl.h
+++ /dev/null
@@ -1,64 +0,0 @@
-// Copyright 2016 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef V8_LOGGING_COUNTERS_INL_H_
-#define V8_LOGGING_COUNTERS_INL_H_
-
-#include "src/logging/counters.h"
-#include "src/logging/tracing-flags.h"
-
-namespace v8 {
-namespace internal {
-
-void RuntimeCallTimer::Start(RuntimeCallCounter* counter,
-                             RuntimeCallTimer* parent) {
-  DCHECK(!IsStarted());
-  counter_ = counter;
-  parent_.SetValue(parent);
-  if (TracingFlags::runtime_stats.load(std::memory_order_relaxed) ==
-      v8::tracing::TracingCategoryObserver::ENABLED_BY_SAMPLING) {
-    return;
-  }
-  base::TimeTicks now = RuntimeCallTimer::Now();
-  if (parent) parent->Pause(now);
-  Resume(now);
-  DCHECK(IsStarted());
-}
-
-void RuntimeCallTimer::Pause(base::TimeTicks now) {
-  DCHECK(IsStarted());
-  elapsed_ += (now - start_ticks_);
-  start_ticks_ = base::TimeTicks();
-}
-
-void RuntimeCallTimer::Resume(base::TimeTicks now) {
-  DCHECK(!IsStarted());
-  start_ticks_ = now;
-}
-
-RuntimeCallTimer* RuntimeCallTimer::Stop() {
-  if (!IsStarted()) return parent();
-  base::TimeTicks now = RuntimeCallTimer::Now();
-  Pause(now);
-  counter_->Increment();
-  CommitTimeToCounter();
-
-  RuntimeCallTimer* parent_timer = parent();
-  if (parent_timer) {
-    parent_timer->Resume(now);
-  }
-  return parent_timer;
-}
-
-void RuntimeCallTimer::CommitTimeToCounter() {
-  counter_->Add(elapsed_);
-  elapsed_ = base::TimeDelta();
-}
-
-bool RuntimeCallTimer::IsStarted() { return start_ticks_ != base::TimeTicks(); }
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_LOGGING_COUNTERS_INL_H_
diff --git a/chromium/v8/src/logging/counters.cc b/chromium/v8/src/logging/counters.cc
index c9c9aa0ebe5..3ffced08324 100644
--- a/chromium/v8/src/logging/counters.cc
+++ b/chromium/v8/src/logging/counters.cc
@@ -4,16 +4,13 @@
 
 #include "src/logging/counters.h"
 
-#include <iomanip>
-
-#include "src/base/platform/platform.h"
+#include "src/base/atomic-utils.h"
+#include "src/base/platform/elapsed-timer.h"
 #include "src/base/platform/time.h"
 #include "src/builtins/builtins-definitions.h"
 #include "src/execution/isolate.h"
-#include "src/logging/counters-inl.h"
 #include "src/logging/log-inl.h"
 #include "src/logging/log.h"
-#include "src/utils/ostreams.h"
 
 namespace v8 {
 namespace internal {
@@ -121,15 +118,16 @@ void TimedHistogram::RecordAbandon(base::ElapsedTimer* timer,
 }
 
 Counters::Counters(Isolate* isolate)
-    : isolate_(isolate),
-      stats_table_(this),
-// clang format off
+    :
 #define SC(name, caption) name##_(this, "c:" #caption),
       STATS_COUNTER_TS_LIST(SC)
 #undef SC
-      // clang format on
-      runtime_call_stats_(RuntimeCallStats::kMainIsolateThread),
-      worker_thread_runtime_call_stats_() {
+#ifdef V8_RUNTIME_CALL_STATS
+          runtime_call_stats_(RuntimeCallStats::kMainIsolateThread),
+      worker_thread_runtime_call_stats_(),
+#endif
+      isolate_(isolate),
+      stats_table_(this) {
   static const struct {
     Histogram Counters::*member;
     const char* caption;
@@ -319,355 +317,5 @@ void Counters::ResetCreateHistogramFunction(CreateHistogramCallback f) {
 #undef HM
 }
 
-base::TimeTicks (*RuntimeCallTimer::Now)() =
-    &base::TimeTicks::HighResolutionNow;
-
-base::TimeTicks RuntimeCallTimer::NowCPUTime() {
-  base::ThreadTicks ticks = base::ThreadTicks::Now();
-  return base::TimeTicks::FromInternalValue(ticks.ToInternalValue());
-}
-
-class RuntimeCallStatEntries {
- public:
-  void Print(std::ostream& os) {
-    if (total_call_count == 0) return;
-    std::sort(entries.rbegin(), entries.rend());
-    os << std::setw(50) << "Runtime Function/C++ Builtin" << std::setw(12)
-       << "Time" << std::setw(18) << "Count" << std::endl
-       << std::string(88, '=') << std::endl;
-    for (Entry& entry : entries) {
-      entry.SetTotal(total_time, total_call_count);
-      entry.Print(os);
-    }
-    os << std::string(88, '-') << std::endl;
-    Entry("Total", total_time, total_call_count).Print(os);
-  }
-
-  // By default, the compiler will usually inline this, which results in a large
-  // binary size increase: std::vector::push_back expands to a large amount of
-  // instructions, and this function is invoked repeatedly by macros.
-  V8_NOINLINE void Add(RuntimeCallCounter* counter) {
-    if (counter->count() == 0) return;
-    entries.push_back(
-        Entry(counter->name(), counter->time(), counter->count()));
-    total_time += counter->time();
-    total_call_count += counter->count();
-  }
-
- private:
-  class Entry {
-   public:
-    Entry(const char* name, base::TimeDelta time, uint64_t count)
-        : name_(name),
-          time_(time.InMicroseconds()),
-          count_(count),
-          time_percent_(100),
-          count_percent_(100) {}
-
-    bool operator<(const Entry& other) const {
-      if (time_ < other.time_) return true;
-      if (time_ > other.time_) return false;
-      return count_ < other.count_;
-    }
-
-    V8_NOINLINE void Print(std::ostream& os) {
-      os.precision(2);
-      os << std::fixed << std::setprecision(2);
-      os << std::setw(50) << name_;
-      os << std::setw(10) << static_cast<double>(time_) / 1000 << "ms ";
-      os << std::setw(6) << time_percent_ << "%";
-      os << std::setw(10) << count_ << " ";
-      os << std::setw(6) << count_percent_ << "%";
-      os << std::endl;
-    }
-
-    V8_NOINLINE void SetTotal(base::TimeDelta total_time,
-                              uint64_t total_count) {
-      if (total_time.InMicroseconds() == 0) {
-        time_percent_ = 0;
-      } else {
-        time_percent_ = 100.0 * time_ / total_time.InMicroseconds();
-      }
-      count_percent_ = 100.0 * count_ / total_count;
-    }
-
-   private:
-    const char* name_;
-    int64_t time_;
-    uint64_t count_;
-    double time_percent_;
-    double count_percent_;
-  };
-
-  uint64_t total_call_count = 0;
-  base::TimeDelta total_time;
-  std::vector<Entry> entries;
-};
-
-void RuntimeCallCounter::Reset() {
-  count_ = 0;
-  time_ = 0;
-}
-
-void RuntimeCallCounter::Dump(v8::tracing::TracedValue* value) {
-  value->BeginArray(name_);
-  value->AppendDouble(count_);
-  value->AppendDouble(time_);
-  value->EndArray();
-}
-
-void RuntimeCallCounter::Add(RuntimeCallCounter* other) {
-  count_ += other->count();
-  time_ += other->time().InMicroseconds();
-}
-
-void RuntimeCallTimer::Snapshot() {
-  base::TimeTicks now = Now();
-  // Pause only / topmost timer in the timer stack.
-  Pause(now);
-  // Commit all the timer's elapsed time to the counters.
-  RuntimeCallTimer* timer = this;
-  while (timer != nullptr) {
-    timer->CommitTimeToCounter();
-    timer = timer->parent();
-  }
-  Resume(now);
-}
-
-RuntimeCallStats::RuntimeCallStats(ThreadType thread_type)
-    : in_use_(false), thread_type_(thread_type) {
-  static const char* const kNames[] = {
-#define CALL_BUILTIN_COUNTER(name) "GC_" #name,
-      FOR_EACH_GC_COUNTER(CALL_BUILTIN_COUNTER)  //
-#undef CALL_BUILTIN_COUNTER
-#define CALL_RUNTIME_COUNTER(name) #name,
-      FOR_EACH_MANUAL_COUNTER(CALL_RUNTIME_COUNTER)  //
-#undef CALL_RUNTIME_COUNTER
-#define CALL_RUNTIME_COUNTER(name, nargs, ressize) #name,
-      FOR_EACH_INTRINSIC(CALL_RUNTIME_COUNTER)  //
-#undef CALL_RUNTIME_COUNTER
-#define CALL_BUILTIN_COUNTER(name) #name,
-      BUILTIN_LIST_C(CALL_BUILTIN_COUNTER)  //
-#undef CALL_BUILTIN_COUNTER
-#define CALL_BUILTIN_COUNTER(name) "API_" #name,
-      FOR_EACH_API_COUNTER(CALL_BUILTIN_COUNTER)  //
-#undef CALL_BUILTIN_COUNTER
-#define CALL_BUILTIN_COUNTER(name) #name,
-      FOR_EACH_HANDLER_COUNTER(CALL_BUILTIN_COUNTER)  //
-#undef CALL_BUILTIN_COUNTER
-#define THREAD_SPECIFIC_COUNTER(name) #name,
-      FOR_EACH_THREAD_SPECIFIC_COUNTER(THREAD_SPECIFIC_COUNTER)  //
-#undef THREAD_SPECIFIC_COUNTER
-  };
-  for (int i = 0; i < kNumberOfCounters; i++) {
-    this->counters_[i] = RuntimeCallCounter(kNames[i]);
-  }
-  if (FLAG_rcs_cpu_time) {
-    CHECK(base::ThreadTicks::IsSupported());
-    base::ThreadTicks::WaitUntilInitialized();
-    RuntimeCallTimer::Now = &RuntimeCallTimer::NowCPUTime;
-  }
-}
-
-namespace {
-constexpr RuntimeCallCounterId FirstCounter(RuntimeCallCounterId first, ...) {
-  return first;
-}
-
-#define THREAD_SPECIFIC_COUNTER(name) k##name,
-constexpr RuntimeCallCounterId kFirstThreadVariantCounter =
-    FirstCounter(FOR_EACH_THREAD_SPECIFIC_COUNTER(THREAD_SPECIFIC_COUNTER) 0);
-#undef THREAD_SPECIFIC_COUNTER
-
-#define THREAD_SPECIFIC_COUNTER(name) +1
-constexpr int kThreadVariantCounterCount =
-    0 FOR_EACH_THREAD_SPECIFIC_COUNTER(THREAD_SPECIFIC_COUNTER);
-#undef THREAD_SPECIFIC_COUNTER
-
-constexpr auto kLastThreadVariantCounter = static_cast<RuntimeCallCounterId>(
-    kFirstThreadVariantCounter + kThreadVariantCounterCount - 1);
-}  // namespace
-
-bool RuntimeCallStats::HasThreadSpecificCounterVariants(
-    RuntimeCallCounterId id) {
-  // Check that it's in the range of the thread-specific variant counters and
-  // also that it's one of the background counters.
-  return id >= kFirstThreadVariantCounter && id <= kLastThreadVariantCounter;
-}
-
-bool RuntimeCallStats::IsBackgroundThreadSpecificVariant(
-    RuntimeCallCounterId id) {
-  return HasThreadSpecificCounterVariants(id) &&
-         (id - kFirstThreadVariantCounter) % 2 == 1;
-}
-
-void RuntimeCallStats::Enter(RuntimeCallTimer* timer,
-                             RuntimeCallCounterId counter_id) {
-  DCHECK(IsCalledOnTheSameThread());
-  RuntimeCallCounter* counter = GetCounter(counter_id);
-  DCHECK_NOT_NULL(counter->name());
-  timer->Start(counter, current_timer());
-  current_timer_.SetValue(timer);
-  current_counter_.SetValue(counter);
-}
-
-void RuntimeCallStats::Leave(RuntimeCallTimer* timer) {
-  DCHECK(IsCalledOnTheSameThread());
-  RuntimeCallTimer* stack_top = current_timer();
-  if (stack_top == nullptr) return;  // Missing timer is a result of Reset().
-  CHECK(stack_top == timer);
-  current_timer_.SetValue(timer->Stop());
-  RuntimeCallTimer* cur_timer = current_timer();
-  current_counter_.SetValue(cur_timer ? cur_timer->counter() : nullptr);
-}
-
-void RuntimeCallStats::Add(RuntimeCallStats* other) {
-  for (int i = 0; i < kNumberOfCounters; i++) {
-    GetCounter(i)->Add(other->GetCounter(i));
-  }
-}
-
-// static
-void RuntimeCallStats::CorrectCurrentCounterId(RuntimeCallCounterId counter_id,
-                                               CounterMode mode) {
-  DCHECK(IsCalledOnTheSameThread());
-  if (mode == RuntimeCallStats::CounterMode::kThreadSpecific) {
-    counter_id = CounterIdForThread(counter_id);
-  }
-  DCHECK(IsCounterAppropriateForThread(counter_id));
-
-  RuntimeCallTimer* timer = current_timer();
-  if (timer == nullptr) return;
-  RuntimeCallCounter* counter = GetCounter(counter_id);
-  timer->set_counter(counter);
-  current_counter_.SetValue(counter);
-}
-
-bool RuntimeCallStats::IsCalledOnTheSameThread() {
-  if (thread_id_.IsValid()) return thread_id_ == ThreadId::Current();
-  thread_id_ = ThreadId::Current();
-  return true;
-}
-
-void RuntimeCallStats::Print() {
-  StdoutStream os;
-  Print(os);
-}
-
-void RuntimeCallStats::Print(std::ostream& os) {
-  RuntimeCallStatEntries entries;
-  if (current_timer_.Value() != nullptr) {
-    current_timer_.Value()->Snapshot();
-  }
-  for (int i = 0; i < kNumberOfCounters; i++) {
-    entries.Add(GetCounter(i));
-  }
-  entries.Print(os);
-}
-
-void RuntimeCallStats::EnumerateCounters(
-    debug::RuntimeCallCounterCallback callback) {
-  if (current_timer_.Value() != nullptr) {
-    current_timer_.Value()->Snapshot();
-  }
-  for (int i = 0; i < kNumberOfCounters; i++) {
-    RuntimeCallCounter* counter = GetCounter(i);
-    callback(counter->name(), counter->count(), counter->time());
-  }
-}
-
-void RuntimeCallStats::Reset() {
-  if (V8_LIKELY(!TracingFlags::is_runtime_stats_enabled())) return;
-
-  // In tracing, we only what to trace the time spent on top level trace events,
-  // if runtime counter stack is not empty, we should clear the whole runtime
-  // counter stack, and then reset counters so that we can dump counters into
-  // top level trace events accurately.
-  while (current_timer_.Value()) {
-    current_timer_.SetValue(current_timer_.Value()->Stop());
-  }
-
-  for (int i = 0; i < kNumberOfCounters; i++) {
-    GetCounter(i)->Reset();
-  }
-
-  in_use_ = true;
-}
-
-void RuntimeCallStats::Dump(v8::tracing::TracedValue* value) {
-  for (int i = 0; i < kNumberOfCounters; i++) {
-    if (GetCounter(i)->count() > 0) GetCounter(i)->Dump(value);
-  }
-  in_use_ = false;
-}
-
-WorkerThreadRuntimeCallStats::WorkerThreadRuntimeCallStats()
-    : isolate_thread_id_(ThreadId::Current()) {}
-
-WorkerThreadRuntimeCallStats::~WorkerThreadRuntimeCallStats() {
-  if (tls_key_) base::Thread::DeleteThreadLocalKey(*tls_key_);
-}
-
-base::Thread::LocalStorageKey WorkerThreadRuntimeCallStats::GetKey() {
-  base::MutexGuard lock(&mutex_);
-  DCHECK(TracingFlags::is_runtime_stats_enabled());
-  if (!tls_key_) tls_key_ = base::Thread::CreateThreadLocalKey();
-  return *tls_key_;
-}
-
-RuntimeCallStats* WorkerThreadRuntimeCallStats::NewTable() {
-  DCHECK(TracingFlags::is_runtime_stats_enabled());
-  // Never create a new worker table on the isolate's main thread.
-  DCHECK_NE(ThreadId::Current(), isolate_thread_id_);
-  std::unique_ptr<RuntimeCallStats> new_table =
-      std::make_unique<RuntimeCallStats>(RuntimeCallStats::kWorkerThread);
-  RuntimeCallStats* result = new_table.get();
-
-  base::MutexGuard lock(&mutex_);
-  tables_.push_back(std::move(new_table));
-  return result;
-}
-
-void WorkerThreadRuntimeCallStats::AddToMainTable(
-    RuntimeCallStats* main_call_stats) {
-  base::MutexGuard lock(&mutex_);
-  for (auto& worker_stats : tables_) {
-    DCHECK_NE(main_call_stats, worker_stats.get());
-    main_call_stats->Add(worker_stats.get());
-    worker_stats->Reset();
-  }
-}
-
-WorkerThreadRuntimeCallStatsScope::WorkerThreadRuntimeCallStatsScope(
-    WorkerThreadRuntimeCallStats* worker_stats)
-    : table_(nullptr) {
-  if (V8_LIKELY(!TracingFlags::is_runtime_stats_enabled())) return;
-
-  table_ = reinterpret_cast<RuntimeCallStats*>(
-      base::Thread::GetThreadLocal(worker_stats->GetKey()));
-  if (table_ == nullptr) {
-    table_ = worker_stats->NewTable();
-    base::Thread::SetThreadLocal(worker_stats->GetKey(), table_);
-  }
-
-  if ((TracingFlags::runtime_stats.load(std::memory_order_relaxed) &
-       v8::tracing::TracingCategoryObserver::ENABLED_BY_TRACING)) {
-    table_->Reset();
-  }
-}
-
-WorkerThreadRuntimeCallStatsScope::~WorkerThreadRuntimeCallStatsScope() {
-  if (V8_LIKELY(table_ == nullptr)) return;
-
-  if ((TracingFlags::runtime_stats.load(std::memory_order_relaxed) &
-       v8::tracing::TracingCategoryObserver::ENABLED_BY_TRACING)) {
-    auto value = v8::tracing::TracedValue::Create();
-    table_->Dump(value.get());
-    TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("v8.runtime_stats"),
-                         "V8.RuntimeStats", TRACE_EVENT_SCOPE_THREAD,
-                         "runtime-call-stats", std::move(value));
-  }
-}
-
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/logging/counters.h b/chromium/v8/src/logging/counters.h
index 89cda727542..0de6a8d0e66 100644
--- a/chromium/v8/src/logging/counters.h
+++ b/chromium/v8/src/logging/counters.h
@@ -13,16 +13,10 @@
 #include "src/base/platform/elapsed-timer.h"
 #include "src/base/platform/time.h"
 #include "src/common/globals.h"
-#include "src/debug/debug-interface.h"
 #include "src/execution/isolate.h"
-#include "src/init/heap-symbols.h"
 #include "src/logging/counters-definitions.h"
-#include "src/logging/tracing-flags.h"
+#include "src/logging/runtime-call-stats.h"
 #include "src/objects/objects.h"
-#include "src/runtime/runtime.h"
-#include "src/tracing/trace-event.h"
-#include "src/tracing/traced-value.h"
-#include "src/tracing/tracing-category-observer.h"
 #include "src/utils/allocation.h"
 
 namespace v8 {
@@ -648,668 +642,6 @@ double AggregatedMemoryHistogram<Histogram>::Aggregate(double current_ms,
          value * ((current_ms - last_ms_) / interval_ms);
 }
 
-class RuntimeCallCounter final {
- public:
-  RuntimeCallCounter() : RuntimeCallCounter(nullptr) {}
-  explicit RuntimeCallCounter(const char* name)
-      : name_(name), count_(0), time_(0) {}
-  V8_NOINLINE void Reset();
-  V8_NOINLINE void Dump(v8::tracing::TracedValue* value);
-  void Add(RuntimeCallCounter* other);
-
-  const char* name() const { return name_; }
-  int64_t count() const { return count_; }
-  base::TimeDelta time() const {
-    return base::TimeDelta::FromMicroseconds(time_);
-  }
-  void Increment() { count_++; }
-  void Add(base::TimeDelta delta) { time_ += delta.InMicroseconds(); }
-
- private:
-  friend class RuntimeCallStats;
-
-  const char* name_;
-  int64_t count_;
-  // Stored as int64_t so that its initialization can be deferred.
-  int64_t time_;
-};
-
-// RuntimeCallTimer is used to keep track of the stack of currently active
-// timers used for properly measuring the own time of a RuntimeCallCounter.
-class RuntimeCallTimer final {
- public:
-  RuntimeCallCounter* counter() { return counter_; }
-  void set_counter(RuntimeCallCounter* counter) { counter_ = counter; }
-  RuntimeCallTimer* parent() const { return parent_.Value(); }
-  void set_parent(RuntimeCallTimer* timer) { parent_.SetValue(timer); }
-  const char* name() const { return counter_->name(); }
-
-  inline bool IsStarted();
-
-  inline void Start(RuntimeCallCounter* counter, RuntimeCallTimer* parent);
-  void Snapshot();
-  inline RuntimeCallTimer* Stop();
-
-  // Make the time source configurable for testing purposes.
-  V8_EXPORT_PRIVATE static base::TimeTicks (*Now)();
-
-  // Helper to switch over to CPU time.
-  static base::TimeTicks NowCPUTime();
-
- private:
-  inline void Pause(base::TimeTicks now);
-  inline void Resume(base::TimeTicks now);
-  inline void CommitTimeToCounter();
-
-  RuntimeCallCounter* counter_ = nullptr;
-  base::AtomicValue<RuntimeCallTimer*> parent_;
-  base::TimeTicks start_ticks_;
-  base::TimeDelta elapsed_;
-};
-
-#define FOR_EACH_GC_COUNTER(V) \
-  TRACER_SCOPES(V)             \
-  TRACER_BACKGROUND_SCOPES(V)
-
-#define FOR_EACH_API_COUNTER(V)                            \
-  V(AccessorPair_New)                                      \
-  V(ArrayBuffer_Cast)                                      \
-  V(ArrayBuffer_Detach)                                    \
-  V(ArrayBuffer_New)                                       \
-  V(ArrayBuffer_NewBackingStore)                           \
-  V(ArrayBuffer_BackingStore_Reallocate)                   \
-  V(Array_CloneElementAt)                                  \
-  V(Array_New)                                             \
-  V(BigInt64Array_New)                                     \
-  V(BigInt_NewFromWords)                                   \
-  V(BigIntObject_BigIntValue)                              \
-  V(BigIntObject_New)                                      \
-  V(BigUint64Array_New)                                    \
-  V(BooleanObject_BooleanValue)                            \
-  V(BooleanObject_New)                                     \
-  V(Context_New)                                           \
-  V(Context_NewRemoteContext)                              \
-  V(DataView_New)                                          \
-  V(Date_New)                                              \
-  V(Date_NumberValue)                                      \
-  V(Debug_Call)                                            \
-  V(debug_GetPrivateMembers)                               \
-  V(Error_New)                                             \
-  V(External_New)                                          \
-  V(Float32Array_New)                                      \
-  V(Float64Array_New)                                      \
-  V(Function_Call)                                         \
-  V(Function_New)                                          \
-  V(Function_FunctionProtoToString)                        \
-  V(Function_NewInstance)                                  \
-  V(FunctionTemplate_GetFunction)                          \
-  V(FunctionTemplate_New)                                  \
-  V(FunctionTemplate_NewRemoteInstance)                    \
-  V(FunctionTemplate_NewWithCache)                         \
-  V(FunctionTemplate_NewWithFastHandler)                   \
-  V(Int16Array_New)                                        \
-  V(Int32Array_New)                                        \
-  V(Int8Array_New)                                         \
-  V(Isolate_DateTimeConfigurationChangeNotification)       \
-  V(Isolate_LocaleConfigurationChangeNotification)         \
-  V(JSON_Parse)                                            \
-  V(JSON_Stringify)                                        \
-  V(Map_AsArray)                                           \
-  V(Map_Clear)                                             \
-  V(Map_Delete)                                            \
-  V(Map_Get)                                               \
-  V(Map_Has)                                               \
-  V(Map_New)                                               \
-  V(Map_Set)                                               \
-  V(Message_GetEndColumn)                                  \
-  V(Message_GetLineNumber)                                 \
-  V(Message_GetSourceLine)                                 \
-  V(Message_GetStartColumn)                                \
-  V(Module_Evaluate)                                       \
-  V(Module_InstantiateModule)                              \
-  V(Module_SetSyntheticModuleExport)                       \
-  V(NumberObject_New)                                      \
-  V(NumberObject_NumberValue)                              \
-  V(Object_CallAsConstructor)                              \
-  V(Object_CallAsFunction)                                 \
-  V(Object_CreateDataProperty)                             \
-  V(Object_DefineOwnProperty)                              \
-  V(Object_DefineProperty)                                 \
-  V(Object_Delete)                                         \
-  V(Object_DeleteProperty)                                 \
-  V(Object_ForceSet)                                       \
-  V(Object_Get)                                            \
-  V(Object_GetOwnPropertyDescriptor)                       \
-  V(Object_GetOwnPropertyNames)                            \
-  V(Object_GetPropertyAttributes)                          \
-  V(Object_GetPropertyNames)                               \
-  V(Object_GetRealNamedProperty)                           \
-  V(Object_GetRealNamedPropertyAttributes)                 \
-  V(Object_GetRealNamedPropertyAttributesInPrototypeChain) \
-  V(Object_GetRealNamedPropertyInPrototypeChain)           \
-  V(Object_Has)                                            \
-  V(Object_HasOwnProperty)                                 \
-  V(Object_HasRealIndexedProperty)                         \
-  V(Object_HasRealNamedCallbackProperty)                   \
-  V(Object_HasRealNamedProperty)                           \
-  V(Object_IsCodeLike)                                     \
-  V(Object_New)                                            \
-  V(Object_ObjectProtoToString)                            \
-  V(Object_Set)                                            \
-  V(Object_SetAccessor)                                    \
-  V(Object_SetIntegrityLevel)                              \
-  V(Object_SetPrivate)                                     \
-  V(Object_SetPrototype)                                   \
-  V(ObjectTemplate_New)                                    \
-  V(ObjectTemplate_NewInstance)                            \
-  V(Object_ToArrayIndex)                                   \
-  V(Object_ToBigInt)                                       \
-  V(Object_ToDetailString)                                 \
-  V(Object_ToInt32)                                        \
-  V(Object_ToInteger)                                      \
-  V(Object_ToNumber)                                       \
-  V(Object_ToObject)                                       \
-  V(Object_ToString)                                       \
-  V(Object_ToUint32)                                       \
-  V(Persistent_New)                                        \
-  V(Private_New)                                           \
-  V(Promise_Catch)                                         \
-  V(Promise_Chain)                                         \
-  V(Promise_HasRejectHandler)                              \
-  V(Promise_Resolver_New)                                  \
-  V(Promise_Resolver_Reject)                               \
-  V(Promise_Resolver_Resolve)                              \
-  V(Promise_Result)                                        \
-  V(Promise_Status)                                        \
-  V(Promise_Then)                                          \
-  V(Proxy_New)                                             \
-  V(RangeError_New)                                        \
-  V(ReferenceError_New)                                    \
-  V(RegExp_Exec)                                           \
-  V(RegExp_New)                                            \
-  V(ScriptCompiler_Compile)                                \
-  V(ScriptCompiler_CompileFunctionInContext)               \
-  V(ScriptCompiler_CompileUnbound)                         \
-  V(Script_Run)                                            \
-  V(Set_Add)                                               \
-  V(Set_AsArray)                                           \
-  V(Set_Clear)                                             \
-  V(Set_Delete)                                            \
-  V(Set_Has)                                               \
-  V(Set_New)                                               \
-  V(SharedArrayBuffer_New)                                 \
-  V(SharedArrayBuffer_NewBackingStore)                     \
-  V(String_Concat)                                         \
-  V(String_NewExternalOneByte)                             \
-  V(String_NewExternalTwoByte)                             \
-  V(String_NewFromOneByte)                                 \
-  V(String_NewFromTwoByte)                                 \
-  V(String_NewFromUtf8)                                    \
-  V(String_NewFromUtf8Literal)                             \
-  V(StringObject_New)                                      \
-  V(StringObject_StringValue)                              \
-  V(String_Write)                                          \
-  V(String_WriteUtf8)                                      \
-  V(Symbol_New)                                            \
-  V(SymbolObject_New)                                      \
-  V(SymbolObject_SymbolValue)                              \
-  V(SyntaxError_New)                                       \
-  V(TracedGlobal_New)                                      \
-  V(TryCatch_StackTrace)                                   \
-  V(TypeError_New)                                         \
-  V(Uint16Array_New)                                       \
-  V(Uint32Array_New)                                       \
-  V(Uint8Array_New)                                        \
-  V(Uint8ClampedArray_New)                                 \
-  V(UnboundScript_GetId)                                   \
-  V(UnboundScript_GetLineNumber)                           \
-  V(UnboundScript_GetName)                                 \
-  V(UnboundScript_GetSourceMappingURL)                     \
-  V(UnboundScript_GetSourceURL)                            \
-  V(ValueDeserializer_ReadHeader)                          \
-  V(ValueDeserializer_ReadValue)                           \
-  V(ValueSerializer_WriteValue)                            \
-  V(Value_Equals)                                          \
-  V(Value_InstanceOf)                                      \
-  V(Value_Int32Value)                                      \
-  V(Value_IntegerValue)                                    \
-  V(Value_NumberValue)                                     \
-  V(Value_TypeOf)                                          \
-  V(Value_Uint32Value)                                     \
-  V(WasmCompileError_New)                                  \
-  V(WasmLinkError_New)                                     \
-  V(WasmRuntimeError_New)                                  \
-  V(WeakMap_Get)                                           \
-  V(WeakMap_New)                                           \
-  V(WeakMap_Set)
-
-#define ADD_THREAD_SPECIFIC_COUNTER(V, Prefix, Suffix) \
-  V(Prefix##Suffix)                                    \
-  V(Prefix##Background##Suffix)
-
-#define FOR_EACH_THREAD_SPECIFIC_COUNTER(V)                                 \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Compile, Analyse)                          \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Compile, Eval)                             \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Compile, Function)                         \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Compile, Ignition)                         \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Compile, IgnitionFinalization)             \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Compile, RewriteReturnResult)              \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Compile, ScopeAnalysis)                    \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Compile, Script)                           \
-                                                                            \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, AllocateFPRegisters)             \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, AllocateGeneralRegisters)        \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, AssembleCode)                    \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, AssignSpillSlots)                \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, BuildLiveRangeBundles)           \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, BuildLiveRanges)                 \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, BytecodeGraphBuilder)            \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, CommitAssignment)                \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, ConnectRanges)                   \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, ControlFlowOptimization)         \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, CSAEarlyOptimization)            \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, CSAOptimization)                 \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, DecideSpillingMode)              \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, DecompressionOptimization)       \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, EarlyOptimization)               \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, EarlyTrimming)                   \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, EffectLinearization)             \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, EscapeAnalysis)                  \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, FinalizeCode)                    \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, FrameElision)                    \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, GenericLowering)                 \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, Inlining)                        \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, JumpThreading)                   \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, MidTierPopulateReferenceMaps)    \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, MidTierRegisterAllocator)        \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, MidTierRegisterOutputDefinition) \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, MidTierSpillSlotAllocator)       \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, LateGraphTrimming)               \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, LateOptimization)                \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, LoadElimination)                 \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, LocateSpillSlots)                \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, LoopExitElimination)             \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, LoopPeeling)                     \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, MachineOperatorOptimization)     \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, MeetRegisterConstraints)         \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, MemoryOptimization)              \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, OptimizeMoves)                   \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, PopulatePointerMaps)             \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, PrintGraph)                      \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, ResolveControlFlow)              \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, ResolvePhis)                     \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize,                                  \
-                              ScheduledEffectControlLinearization)          \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, ScheduledMachineLowering)        \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, Scheduling)                      \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, SelectInstructions)              \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, SimplifiedLowering)              \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, StoreStoreElimination)           \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, TypeAssertions)                  \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, TypedLowering)                   \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, Typer)                           \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, Untyper)                         \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, VerifyGraph)                     \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, WasmBaseOptimization)            \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, WasmInlining)                    \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, WasmLoopUnrolling)               \
-                                                                            \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Parse, ArrowFunctionLiteral)               \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Parse, FunctionLiteral)                    \
-  ADD_THREAD_SPECIFIC_COUNTER(V, Parse, Program)                            \
-  ADD_THREAD_SPECIFIC_COUNTER(V, PreParse, ArrowFunctionLiteral)            \
-  ADD_THREAD_SPECIFIC_COUNTER(V, PreParse, WithVariableResolution)
-
-#define FOR_EACH_MANUAL_COUNTER(V)             \
-  V(AccessorGetterCallback)                    \
-  V(AccessorSetterCallback)                    \
-  V(ArrayLengthGetter)                         \
-  V(ArrayLengthSetter)                         \
-  V(BoundFunctionLengthGetter)                 \
-  V(BoundFunctionNameGetter)                   \
-  V(CodeGenerationFromStringsCallbacks)        \
-  V(CompileBackgroundCompileTask)              \
-  V(CompileBaseline)                           \
-  V(CompileBaselineVisit)                      \
-  V(CompileBaselinePreVisit)                   \
-  V(CompileCollectSourcePositions)             \
-  V(CompileDeserialize)                        \
-  V(CompileEnqueueOnDispatcher)                \
-  V(CompileFinalizeBackgroundCompileTask)      \
-  V(CompileFinishNowOnDispatcher)              \
-  V(CompileGetFromOptimizedCodeMap)            \
-  V(CompilePublishBackgroundFinalization)      \
-  V(CompileSerialize)                          \
-  V(CompileWaitForDispatcher)                  \
-  V(ConfigureInstance)                         \
-  V(CreateApiFunction)                         \
-  V(DeoptimizeCode)                            \
-  V(DeserializeContext)                        \
-  V(DeserializeIsolate)                        \
-  V(FinalizationRegistryCleanupFromTask)       \
-  V(FunctionCallback)                          \
-  V(FunctionLengthGetter)                      \
-  V(FunctionPrototypeGetter)                   \
-  V(FunctionPrototypeSetter)                   \
-  V(GC_Custom_AllAvailableGarbage)             \
-  V(GC_Custom_IncrementalMarkingObserver)      \
-  V(GC_Custom_SlowAllocateRaw)                 \
-  V(GCEpilogueCallback)                        \
-  V(GCPrologueCallback)                        \
-  V(Genesis)                                   \
-  V(GetCompatibleReceiver)                     \
-  V(GetMoreDataCallback)                       \
-  V(IndexedDefinerCallback)                    \
-  V(IndexedDeleterCallback)                    \
-  V(IndexedDescriptorCallback)                 \
-  V(IndexedEnumeratorCallback)                 \
-  V(IndexedGetterCallback)                     \
-  V(IndexedQueryCallback)                      \
-  V(IndexedSetterCallback)                     \
-  V(InstantiateFunction)                       \
-  V(InstantiateObject)                         \
-  V(Invoke)                                    \
-  V(InvokeApiFunction)                         \
-  V(InvokeApiInterruptCallbacks)               \
-  V(IsCompatibleReceiver)                      \
-  V(IsCompatibleReceiverMap)                   \
-  V(IsTemplateFor)                             \
-  V(JS_Execution)                              \
-  V(Map_SetPrototype)                          \
-  V(Map_TransitionToAccessorProperty)          \
-  V(Map_TransitionToDataProperty)              \
-  V(MessageListenerCallback)                   \
-  V(NamedDefinerCallback)                      \
-  V(NamedDeleterCallback)                      \
-  V(NamedDescriptorCallback)                   \
-  V(NamedEnumeratorCallback)                   \
-  V(NamedGetterCallback)                       \
-  V(NamedQueryCallback)                        \
-  V(NamedSetterCallback)                       \
-  V(Object_DeleteProperty)                     \
-  V(ObjectVerify)                              \
-  V(OptimizeBackgroundDispatcherJob)           \
-  V(OptimizeCode)                              \
-  V(OptimizeConcurrentFinalize)                \
-  V(OptimizeConcurrentPrepare)                 \
-  V(OptimizeFinalizePipelineJob)               \
-  V(OptimizeHeapBrokerInitialization)          \
-  V(OptimizeNonConcurrent)                     \
-  V(OptimizeSerialization)                     \
-  V(OptimizeSerializeMetadata)                 \
-  V(ParseEval)                                 \
-  V(ParseFunction)                             \
-  V(PropertyCallback)                          \
-  V(PrototypeMap_TransitionToAccessorProperty) \
-  V(PrototypeMap_TransitionToDataProperty)     \
-  V(PrototypeObject_DeleteProperty)            \
-  V(ReconfigureToDataProperty)                 \
-  V(UpdateProtector)                           \
-  V(StringLengthGetter)                        \
-  V(TestCounter1)                              \
-  V(TestCounter2)                              \
-  V(TestCounter3)
-
-#define FOR_EACH_HANDLER_COUNTER(V)               \
-  V(KeyedLoadIC_KeyedLoadSloppyArgumentsStub)     \
-  V(KeyedLoadIC_LoadElementDH)                    \
-  V(KeyedLoadIC_LoadIndexedInterceptorStub)       \
-  V(KeyedLoadIC_LoadIndexedStringDH)              \
-  V(KeyedLoadIC_SlowStub)                         \
-  V(KeyedStoreIC_ElementsTransitionAndStoreStub)  \
-  V(KeyedStoreIC_KeyedStoreSloppyArgumentsStub)   \
-  V(KeyedStoreIC_SlowStub)                        \
-  V(KeyedStoreIC_StoreElementStub)                \
-  V(KeyedStoreIC_StoreFastElementStub)            \
-  V(LoadGlobalIC_LoadScriptContextField)          \
-  V(LoadGlobalIC_SlowStub)                        \
-  V(LoadIC_FunctionPrototypeStub)                 \
-  V(LoadIC_HandlerCacheHit_Accessor)              \
-  V(LoadIC_LoadAccessorDH)                        \
-  V(LoadIC_LoadAccessorFromPrototypeDH)           \
-  V(LoadIC_LoadApiGetterFromPrototypeDH)          \
-  V(LoadIC_LoadCallback)                          \
-  V(LoadIC_LoadConstantDH)                        \
-  V(LoadIC_LoadConstantFromPrototypeDH)           \
-  V(LoadIC_LoadFieldDH)                           \
-  V(LoadIC_LoadFieldFromPrototypeDH)              \
-  V(LoadIC_LoadGlobalDH)                          \
-  V(LoadIC_LoadGlobalFromPrototypeDH)             \
-  V(LoadIC_LoadIntegerIndexedExoticDH)            \
-  V(LoadIC_LoadInterceptorDH)                     \
-  V(LoadIC_LoadInterceptorFromPrototypeDH)        \
-  V(LoadIC_LoadNativeDataPropertyDH)              \
-  V(LoadIC_LoadNativeDataPropertyFromPrototypeDH) \
-  V(LoadIC_LoadNonexistentDH)                     \
-  V(LoadIC_LoadNonMaskingInterceptorDH)           \
-  V(LoadIC_LoadNormalDH)                          \
-  V(LoadIC_LoadNormalFromPrototypeDH)             \
-  V(LoadIC_NonReceiver)                           \
-  V(LoadIC_SlowStub)                              \
-  V(LoadIC_StringLength)                          \
-  V(LoadIC_StringWrapperLength)                   \
-  V(StoreGlobalIC_SlowStub)                       \
-  V(StoreGlobalIC_StoreScriptContextField)        \
-  V(StoreIC_HandlerCacheHit_Accessor)             \
-  V(StoreIC_NonReceiver)                          \
-  V(StoreIC_SlowStub)                             \
-  V(StoreIC_StoreAccessorDH)                      \
-  V(StoreIC_StoreAccessorOnPrototypeDH)           \
-  V(StoreIC_StoreApiSetterOnPrototypeDH)          \
-  V(StoreIC_StoreFieldDH)                         \
-  V(StoreIC_StoreGlobalDH)                        \
-  V(StoreIC_StoreGlobalTransitionDH)              \
-  V(StoreIC_StoreInterceptorStub)                 \
-  V(StoreIC_StoreNativeDataPropertyDH)            \
-  V(StoreIC_StoreNativeDataPropertyOnPrototypeDH) \
-  V(StoreIC_StoreNormalDH)                        \
-  V(StoreIC_StoreTransitionDH)                    \
-  V(StoreInArrayLiteralIC_SlowStub)
-
-enum RuntimeCallCounterId {
-#define CALL_RUNTIME_COUNTER(name) kGC_##name,
-  FOR_EACH_GC_COUNTER(CALL_RUNTIME_COUNTER)  //
-#undef CALL_RUNTIME_COUNTER
-#define CALL_RUNTIME_COUNTER(name) k##name,
-  FOR_EACH_MANUAL_COUNTER(CALL_RUNTIME_COUNTER)  //
-#undef CALL_RUNTIME_COUNTER
-#define CALL_RUNTIME_COUNTER(name, nargs, ressize) kRuntime_##name,
-  FOR_EACH_INTRINSIC(CALL_RUNTIME_COUNTER)  //
-#undef CALL_RUNTIME_COUNTER
-#define CALL_BUILTIN_COUNTER(name) kBuiltin_##name,
-  BUILTIN_LIST_C(CALL_BUILTIN_COUNTER)  //
-#undef CALL_BUILTIN_COUNTER
-#define CALL_BUILTIN_COUNTER(name) kAPI_##name,
-  FOR_EACH_API_COUNTER(CALL_BUILTIN_COUNTER)  //
-#undef CALL_BUILTIN_COUNTER
-#define CALL_BUILTIN_COUNTER(name) kHandler_##name,
-  FOR_EACH_HANDLER_COUNTER(CALL_BUILTIN_COUNTER)  //
-#undef CALL_BUILTIN_COUNTER
-#define THREAD_SPECIFIC_COUNTER(name) k##name,
-  FOR_EACH_THREAD_SPECIFIC_COUNTER(THREAD_SPECIFIC_COUNTER)  //
-#undef THREAD_SPECIFIC_COUNTER
-  kNumberOfCounters,
-};
-
-class RuntimeCallStats final {
- public:
-  enum ThreadType { kMainIsolateThread, kWorkerThread };
-
-  // If kExact is chosen the counter will be use as given. With kThreadSpecific,
-  // if the RuntimeCallStats was created for a worker thread, then the
-  // background specific version of the counter will be used instead.
-  enum CounterMode { kExact, kThreadSpecific };
-
-  explicit V8_EXPORT_PRIVATE RuntimeCallStats(ThreadType thread_type);
-
-  // Starting measuring the time for a function. This will establish the
-  // connection to the parent counter for properly calculating the own times.
-  V8_EXPORT_PRIVATE void Enter(RuntimeCallTimer* timer,
-                               RuntimeCallCounterId counter_id);
-
-  // Leave a scope for a measured runtime function. This will properly add
-  // the time delta to the current_counter and subtract the delta from its
-  // parent.
-  V8_EXPORT_PRIVATE void Leave(RuntimeCallTimer* timer);
-
-  // Set counter id for the innermost measurement. It can be used to refine
-  // event kind when a runtime entry counter is too generic.
-  V8_EXPORT_PRIVATE void CorrectCurrentCounterId(
-      RuntimeCallCounterId counter_id, CounterMode mode = kExact);
-
-  V8_EXPORT_PRIVATE void Reset();
-  // Add all entries from another stats object.
-  void Add(RuntimeCallStats* other);
-  V8_EXPORT_PRIVATE void Print(std::ostream& os);
-  V8_EXPORT_PRIVATE void Print();
-  V8_NOINLINE void Dump(v8::tracing::TracedValue* value);
-
-  V8_EXPORT_PRIVATE void EnumerateCounters(
-      debug::RuntimeCallCounterCallback callback);
-
-  ThreadId thread_id() const { return thread_id_; }
-  RuntimeCallTimer* current_timer() { return current_timer_.Value(); }
-  RuntimeCallCounter* current_counter() { return current_counter_.Value(); }
-  bool InUse() { return in_use_; }
-  bool IsCalledOnTheSameThread();
-
-  V8_EXPORT_PRIVATE bool IsBackgroundThreadSpecificVariant(
-      RuntimeCallCounterId id);
-  V8_EXPORT_PRIVATE bool HasThreadSpecificCounterVariants(
-      RuntimeCallCounterId id);
-
-  // This should only be called for counters with a dual Background variant. If
-  // on the main thread, this just returns the counter. If on a worker thread,
-  // it returns Background variant of the counter.
-  RuntimeCallCounterId CounterIdForThread(RuntimeCallCounterId id) {
-    DCHECK(HasThreadSpecificCounterVariants(id));
-    // All thread specific counters are laid out with the main thread variant
-    // first followed by the background variant.
-    return thread_type_ == kWorkerThread
-               ? static_cast<RuntimeCallCounterId>(id + 1)
-               : id;
-  }
-
-  bool IsCounterAppropriateForThread(RuntimeCallCounterId id) {
-    // TODO(delphick): We should add background-only counters and ensure that
-    // all counters (not just the thread-specific variants) are only invoked on
-    // the correct thread.
-    if (!HasThreadSpecificCounterVariants(id)) return true;
-    return IsBackgroundThreadSpecificVariant(id) ==
-           (thread_type_ == kWorkerThread);
-  }
-
-  static const int kNumberOfCounters =
-      static_cast<int>(RuntimeCallCounterId::kNumberOfCounters);
-  RuntimeCallCounter* GetCounter(RuntimeCallCounterId counter_id) {
-    return &counters_[static_cast<int>(counter_id)];
-  }
-  RuntimeCallCounter* GetCounter(int counter_id) {
-    return &counters_[counter_id];
-  }
-
- private:
-  // Top of a stack of active timers.
-  base::AtomicValue<RuntimeCallTimer*> current_timer_;
-  // Active counter object associated with current timer.
-  base::AtomicValue<RuntimeCallCounter*> current_counter_;
-  // Used to track nested tracing scopes.
-  bool in_use_;
-  ThreadType thread_type_;
-  ThreadId thread_id_;
-  RuntimeCallCounter counters_[kNumberOfCounters];
-};
-
-class WorkerThreadRuntimeCallStats final {
- public:
-  WorkerThreadRuntimeCallStats();
-  ~WorkerThreadRuntimeCallStats();
-
-  // Returns the TLS key associated with this WorkerThreadRuntimeCallStats.
-  base::Thread::LocalStorageKey GetKey();
-
-  // Returns a new worker thread runtime call stats table managed by this
-  // WorkerThreadRuntimeCallStats.
-  RuntimeCallStats* NewTable();
-
-  // Adds the counters from the worker thread tables to |main_call_stats|.
-  void AddToMainTable(RuntimeCallStats* main_call_stats);
-
- private:
-  base::Mutex mutex_;
-  std::vector<std::unique_ptr<RuntimeCallStats>> tables_;
-  base::Optional<base::Thread::LocalStorageKey> tls_key_;
-  // Since this is for creating worker thread runtime-call stats, record the
-  // main thread ID to ensure we never create a worker RCS table for the main
-  // thread.
-  ThreadId isolate_thread_id_;
-};
-
-// Creating a WorkerThreadRuntimeCallStatsScope will provide a thread-local
-// runtime call stats table, and will dump the table to an immediate trace event
-// when it is destroyed.
-class V8_NODISCARD WorkerThreadRuntimeCallStatsScope final {
- public:
-  explicit WorkerThreadRuntimeCallStatsScope(
-      WorkerThreadRuntimeCallStats* off_thread_stats);
-  ~WorkerThreadRuntimeCallStatsScope();
-
-  RuntimeCallStats* Get() const { return table_; }
-
- private:
-  RuntimeCallStats* table_;
-};
-
-#define CHANGE_CURRENT_RUNTIME_COUNTER(runtime_call_stats, counter_id) \
-  do {                                                                 \
-    if (V8_UNLIKELY(TracingFlags::is_runtime_stats_enabled()) &&       \
-        runtime_call_stats) {                                          \
-      runtime_call_stats->CorrectCurrentCounterId(counter_id);         \
-    }                                                                  \
-  } while (false)
-
-#define TRACE_HANDLER_STATS(isolate, counter_name) \
-  CHANGE_CURRENT_RUNTIME_COUNTER(                  \
-      isolate->counters()->runtime_call_stats(),   \
-      RuntimeCallCounterId::kHandler_##counter_name)
-
-// A RuntimeCallTimerScopes wraps around a RuntimeCallTimer to measure the
-// the time of C++ scope.
-class V8_NODISCARD RuntimeCallTimerScope {
- public:
-  inline RuntimeCallTimerScope(Isolate* isolate,
-                               RuntimeCallCounterId counter_id);
-  inline RuntimeCallTimerScope(RuntimeCallStats* stats,
-                               RuntimeCallCounterId counter_id,
-                               RuntimeCallStats::CounterMode mode =
-                                   RuntimeCallStats::CounterMode::kExact) {
-    if (V8_LIKELY(!TracingFlags::is_runtime_stats_enabled() ||
-                  stats == nullptr)) {
-      return;
-    }
-    stats_ = stats;
-    if (mode == RuntimeCallStats::CounterMode::kThreadSpecific) {
-      counter_id = stats->CounterIdForThread(counter_id);
-    }
-
-    DCHECK(stats->IsCounterAppropriateForThread(counter_id));
-    stats_->Enter(&timer_, counter_id);
-  }
-
-  inline ~RuntimeCallTimerScope() {
-    if (V8_UNLIKELY(stats_ != nullptr)) {
-      stats_->Leave(&timer_);
-    }
-  }
-
-  RuntimeCallTimerScope(const RuntimeCallTimerScope&) = delete;
-  RuntimeCallTimerScope& operator=(const RuntimeCallTimerScope&) = delete;
-
- private:
-  RuntimeCallStats* stats_ = nullptr;
-  RuntimeCallTimer timer_;
-};
-
 // This file contains all the v8 counters that are in use.
 class Counters : public std::enable_shared_from_this<Counters> {
  public:
@@ -1410,11 +742,19 @@ class Counters : public std::enable_shared_from_this<Counters> {
   };
   // clang-format on
 
+#ifdef V8_RUNTIME_CALL_STATS
   RuntimeCallStats* runtime_call_stats() { return &runtime_call_stats_; }
 
   WorkerThreadRuntimeCallStats* worker_thread_runtime_call_stats() {
     return &worker_thread_runtime_call_stats_;
   }
+#else   // V8_RUNTIME_CALL_STATS
+  RuntimeCallStats* runtime_call_stats() { return nullptr; }
+
+  WorkerThreadRuntimeCallStats* worker_thread_runtime_call_stats() {
+    return nullptr;
+  }
+#endif  // V8_RUNTIME_CALL_STATS
 
  private:
   friend class StatsTable;
@@ -1422,9 +762,6 @@ class Counters : public std::enable_shared_from_this<Counters> {
   friend class Histogram;
   friend class HistogramTimer;
 
-  Isolate* isolate_;
-  StatsTable stats_table_;
-
   int* FindLocation(const char* name) {
     return stats_table_.FindLocation(name);
   }
@@ -1491,8 +828,12 @@ class Counters : public std::enable_shared_from_this<Counters> {
   FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(SC)
 #undef SC
 
+#ifdef V8_RUNTIME_CALL_STATS
   RuntimeCallStats runtime_call_stats_;
   WorkerThreadRuntimeCallStats worker_thread_runtime_call_stats_;
+#endif
+  Isolate* isolate_;
+  StatsTable stats_table_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(Counters);
 };
@@ -1505,12 +846,14 @@ void HistogramTimer::Stop() {
   TimedHistogram::Stop(&timer_, counters()->isolate());
 }
 
+#ifdef V8_RUNTIME_CALL_STATS
 RuntimeCallTimerScope::RuntimeCallTimerScope(Isolate* isolate,
                                              RuntimeCallCounterId counter_id) {
   if (V8_LIKELY(!TracingFlags::is_runtime_stats_enabled())) return;
   stats_ = isolate->counters()->runtime_call_stats();
   stats_->Enter(&timer_, counter_id);
 }
+#endif  // defined(V8_RUNTIME_CALL_STATS)
 
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/logging/log.cc b/chromium/v8/src/logging/log.cc
index 110152c56bf..1e76a66a66b 100644
--- a/chromium/v8/src/logging/log.cc
+++ b/chromium/v8/src/logging/log.cc
@@ -1728,12 +1728,14 @@ bool Logger::EnsureLogScriptSource(Script script) {
 }
 
 void Logger::RuntimeCallTimerEvent() {
+#ifdef V8_RUNTIME_CALL_STATS
   RuntimeCallStats* stats = isolate_->counters()->runtime_call_stats();
   RuntimeCallCounter* counter = stats->current_counter();
   if (counter == nullptr) return;
   MSG_BUILDER();
   msg << "active-runtime-timer" << kNext << counter->name();
   msg.WriteToLogFile();
+#endif  // V8_RUNTIME_CALL_STATS
 }
 
 void Logger::TickEvent(TickSample* sample, bool overflow) {
@@ -2127,7 +2129,6 @@ void ExistingCodeLogger::LogCodeObject(Object object) {
     case CodeKind::INTERPRETED_FUNCTION:
     case CodeKind::TURBOFAN:
     case CodeKind::BASELINE:
-    case CodeKind::NATIVE_CONTEXT_INDEPENDENT:
     case CodeKind::TURBOPROP:
       return;  // We log this later using LogCompiledFunctions.
     case CodeKind::BYTECODE_HANDLER:
@@ -2273,9 +2274,10 @@ void ExistingCodeLogger::LogExistingFunction(
       CALL_CODE_EVENT_HANDLER(CallbackEvent(fun_name, entry_point))
 
       // Fast API function.
-      Address c_function = v8::ToCData<Address>(fun_data->GetCFunction());
-      if (c_function != kNullAddress) {
-        CALL_CODE_EVENT_HANDLER(CallbackEvent(fun_name, c_function))
+      int c_functions_count = fun_data->GetCFunctionsCount();
+      for (int i = 0; i < c_functions_count; i++) {
+        CALL_CODE_EVENT_HANDLER(
+            CallbackEvent(fun_name, fun_data->GetCFunction(i)))
       }
     }
   }
diff --git a/chromium/v8/src/logging/log.h b/chromium/v8/src/logging/log.h
index e52f9f28338..ec190320601 100644
--- a/chromium/v8/src/logging/log.h
+++ b/chromium/v8/src/logging/log.h
@@ -208,6 +208,7 @@ class Logger : public CodeEventListener {
                              Handle<String> source) override;
   void CodeMoveEvent(AbstractCode from, AbstractCode to) override;
   void SharedFunctionInfoMoveEvent(Address from, Address to) override;
+  void NativeContextMoveEvent(Address from, Address to) override {}
   void CodeMovingGCEvent() override;
   void CodeDisableOptEvent(Handle<AbstractCode> code,
                            Handle<SharedFunctionInfo> shared) override;
@@ -410,6 +411,7 @@ class V8_EXPORT_PRIVATE CodeEventLogger : public CodeEventListener {
   void GetterCallbackEvent(Handle<Name> name, Address entry_point) override {}
   void SetterCallbackEvent(Handle<Name> name, Address entry_point) override {}
   void SharedFunctionInfoMoveEvent(Address from, Address to) override {}
+  void NativeContextMoveEvent(Address from, Address to) override {}
   void CodeMovingGCEvent() override {}
   void CodeDeoptEvent(Handle<Code> code, DeoptimizeKind kind, Address pc,
                       int fp_to_sp_delta, bool reuse_code) override {}
@@ -475,6 +477,7 @@ class ExternalCodeEventListener : public CodeEventListener {
   void GetterCallbackEvent(Handle<Name> name, Address entry_point) override {}
   void SetterCallbackEvent(Handle<Name> name, Address entry_point) override {}
   void SharedFunctionInfoMoveEvent(Address from, Address to) override {}
+  void NativeContextMoveEvent(Address from, Address to) override {}
   void CodeMoveEvent(AbstractCode from, AbstractCode to) override;
   void CodeDisableOptEvent(Handle<AbstractCode> code,
                            Handle<SharedFunctionInfo> shared) override {}
diff --git a/chromium/v8/src/logging/runtime-call-stats.cc b/chromium/v8/src/logging/runtime-call-stats.cc
new file mode 100644
index 00000000000..86e3215f74e
--- /dev/null
+++ b/chromium/v8/src/logging/runtime-call-stats.cc
@@ -0,0 +1,370 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifdef V8_RUNTIME_CALL_STATS
+
+#include "src/logging/runtime-call-stats.h"
+
+#include <iomanip>
+
+#include "src/tracing/tracing-category-observer.h"
+#include "src/utils/ostreams.h"
+
+namespace v8 {
+namespace internal {
+
+base::TimeTicks (*RuntimeCallTimer::Now)() =
+    &base::TimeTicks::HighResolutionNow;
+
+base::TimeTicks RuntimeCallTimer::NowCPUTime() {
+  base::ThreadTicks ticks = base::ThreadTicks::Now();
+  return base::TimeTicks::FromInternalValue(ticks.ToInternalValue());
+}
+
+class RuntimeCallStatEntries {
+ public:
+  void Print(std::ostream& os) {
+    if (total_call_count == 0) return;
+    std::sort(entries.rbegin(), entries.rend());
+    os << std::setw(50) << "Runtime Function/C++ Builtin" << std::setw(12)
+       << "Time" << std::setw(18) << "Count" << std::endl
+       << std::string(88, '=') << std::endl;
+    for (Entry& entry : entries) {
+      entry.SetTotal(total_time, total_call_count);
+      entry.Print(os);
+    }
+    os << std::string(88, '-') << std::endl;
+    Entry("Total", total_time, total_call_count).Print(os);
+  }
+
+  // By default, the compiler will usually inline this, which results in a large
+  // binary size increase: std::vector::push_back expands to a large amount of
+  // instructions, and this function is invoked repeatedly by macros.
+  V8_NOINLINE void Add(RuntimeCallCounter* counter) {
+    if (counter->count() == 0) return;
+    entries.push_back(
+        Entry(counter->name(), counter->time(), counter->count()));
+    total_time += counter->time();
+    total_call_count += counter->count();
+  }
+
+ private:
+  class Entry {
+   public:
+    Entry(const char* name, base::TimeDelta time, uint64_t count)
+        : name_(name),
+          time_(time.InMicroseconds()),
+          count_(count),
+          time_percent_(100),
+          count_percent_(100) {}
+
+    bool operator<(const Entry& other) const {
+      if (time_ < other.time_) return true;
+      if (time_ > other.time_) return false;
+      return count_ < other.count_;
+    }
+
+    V8_NOINLINE void Print(std::ostream& os) {
+      os.precision(2);
+      os << std::fixed << std::setprecision(2);
+      os << std::setw(50) << name_;
+      os << std::setw(10) << static_cast<double>(time_) / 1000 << "ms ";
+      os << std::setw(6) << time_percent_ << "%";
+      os << std::setw(10) << count_ << " ";
+      os << std::setw(6) << count_percent_ << "%";
+      os << std::endl;
+    }
+
+    V8_NOINLINE void SetTotal(base::TimeDelta total_time,
+                              uint64_t total_count) {
+      if (total_time.InMicroseconds() == 0) {
+        time_percent_ = 0;
+      } else {
+        time_percent_ = 100.0 * time_ / total_time.InMicroseconds();
+      }
+      count_percent_ = 100.0 * count_ / total_count;
+    }
+
+   private:
+    const char* name_;
+    int64_t time_;
+    uint64_t count_;
+    double time_percent_;
+    double count_percent_;
+  };
+
+  uint64_t total_call_count = 0;
+  base::TimeDelta total_time;
+  std::vector<Entry> entries;
+};
+
+void RuntimeCallCounter::Reset() {
+  count_ = 0;
+  time_ = 0;
+}
+
+void RuntimeCallCounter::Dump(v8::tracing::TracedValue* value) {
+  value->BeginArray(name_);
+  value->AppendDouble(count_);
+  value->AppendDouble(time_);
+  value->EndArray();
+}
+
+void RuntimeCallCounter::Add(RuntimeCallCounter* other) {
+  count_ += other->count();
+  time_ += other->time().InMicroseconds();
+}
+
+void RuntimeCallTimer::Snapshot() {
+  base::TimeTicks now = Now();
+  // Pause only / topmost timer in the timer stack.
+  Pause(now);
+  // Commit all the timer's elapsed time to the counters.
+  RuntimeCallTimer* timer = this;
+  while (timer != nullptr) {
+    timer->CommitTimeToCounter();
+    timer = timer->parent();
+  }
+  Resume(now);
+}
+
+RuntimeCallStats::RuntimeCallStats(ThreadType thread_type)
+    : in_use_(false), thread_type_(thread_type) {
+  static const char* const kNames[] = {
+#define CALL_BUILTIN_COUNTER(name) "GC_" #name,
+      FOR_EACH_GC_COUNTER(CALL_BUILTIN_COUNTER)  //
+#undef CALL_BUILTIN_COUNTER
+#define CALL_RUNTIME_COUNTER(name) #name,
+      FOR_EACH_MANUAL_COUNTER(CALL_RUNTIME_COUNTER)  //
+#undef CALL_RUNTIME_COUNTER
+#define CALL_RUNTIME_COUNTER(name, nargs, ressize) #name,
+      FOR_EACH_INTRINSIC(CALL_RUNTIME_COUNTER)  //
+#undef CALL_RUNTIME_COUNTER
+#define CALL_BUILTIN_COUNTER(name) #name,
+      BUILTIN_LIST_C(CALL_BUILTIN_COUNTER)  //
+#undef CALL_BUILTIN_COUNTER
+#define CALL_BUILTIN_COUNTER(name) "API_" #name,
+      FOR_EACH_API_COUNTER(CALL_BUILTIN_COUNTER)  //
+#undef CALL_BUILTIN_COUNTER
+#define CALL_BUILTIN_COUNTER(name) #name,
+      FOR_EACH_HANDLER_COUNTER(CALL_BUILTIN_COUNTER)  //
+#undef CALL_BUILTIN_COUNTER
+#define THREAD_SPECIFIC_COUNTER(name) #name,
+      FOR_EACH_THREAD_SPECIFIC_COUNTER(THREAD_SPECIFIC_COUNTER)  //
+#undef THREAD_SPECIFIC_COUNTER
+  };
+  for (int i = 0; i < kNumberOfCounters; i++) {
+    this->counters_[i] = RuntimeCallCounter(kNames[i]);
+  }
+  if (FLAG_rcs_cpu_time) {
+    CHECK(base::ThreadTicks::IsSupported());
+    base::ThreadTicks::WaitUntilInitialized();
+    RuntimeCallTimer::Now = &RuntimeCallTimer::NowCPUTime;
+  }
+}
+
+namespace {
+constexpr RuntimeCallCounterId FirstCounter(RuntimeCallCounterId first, ...) {
+  return first;
+}
+
+#define THREAD_SPECIFIC_COUNTER(name) k##name,
+constexpr RuntimeCallCounterId kFirstThreadVariantCounter =
+    FirstCounter(FOR_EACH_THREAD_SPECIFIC_COUNTER(THREAD_SPECIFIC_COUNTER) 0);
+#undef THREAD_SPECIFIC_COUNTER
+
+#define THREAD_SPECIFIC_COUNTER(name) +1
+constexpr int kThreadVariantCounterCount =
+    0 FOR_EACH_THREAD_SPECIFIC_COUNTER(THREAD_SPECIFIC_COUNTER);
+#undef THREAD_SPECIFIC_COUNTER
+
+constexpr auto kLastThreadVariantCounter = static_cast<RuntimeCallCounterId>(
+    kFirstThreadVariantCounter + kThreadVariantCounterCount - 1);
+}  // namespace
+
+bool RuntimeCallStats::HasThreadSpecificCounterVariants(
+    RuntimeCallCounterId id) {
+  // Check that it's in the range of the thread-specific variant counters and
+  // also that it's one of the background counters.
+  return id >= kFirstThreadVariantCounter && id <= kLastThreadVariantCounter;
+}
+
+bool RuntimeCallStats::IsBackgroundThreadSpecificVariant(
+    RuntimeCallCounterId id) {
+  return HasThreadSpecificCounterVariants(id) &&
+         (id - kFirstThreadVariantCounter) % 2 == 1;
+}
+
+void RuntimeCallStats::Enter(RuntimeCallTimer* timer,
+                             RuntimeCallCounterId counter_id) {
+  DCHECK(IsCalledOnTheSameThread());
+  RuntimeCallCounter* counter = GetCounter(counter_id);
+  DCHECK_NOT_NULL(counter->name());
+  timer->Start(counter, current_timer());
+  current_timer_.SetValue(timer);
+  current_counter_.SetValue(counter);
+}
+
+void RuntimeCallStats::Leave(RuntimeCallTimer* timer) {
+  DCHECK(IsCalledOnTheSameThread());
+  RuntimeCallTimer* stack_top = current_timer();
+  if (stack_top == nullptr) return;  // Missing timer is a result of Reset().
+  CHECK(stack_top == timer);
+  current_timer_.SetValue(timer->Stop());
+  RuntimeCallTimer* cur_timer = current_timer();
+  current_counter_.SetValue(cur_timer ? cur_timer->counter() : nullptr);
+}
+
+void RuntimeCallStats::Add(RuntimeCallStats* other) {
+  for (int i = 0; i < kNumberOfCounters; i++) {
+    GetCounter(i)->Add(other->GetCounter(i));
+  }
+}
+
+// static
+void RuntimeCallStats::CorrectCurrentCounterId(RuntimeCallCounterId counter_id,
+                                               CounterMode mode) {
+  DCHECK(IsCalledOnTheSameThread());
+  if (mode == RuntimeCallStats::CounterMode::kThreadSpecific) {
+    counter_id = CounterIdForThread(counter_id);
+  }
+  DCHECK(IsCounterAppropriateForThread(counter_id));
+
+  RuntimeCallTimer* timer = current_timer();
+  if (timer == nullptr) return;
+  RuntimeCallCounter* counter = GetCounter(counter_id);
+  timer->set_counter(counter);
+  current_counter_.SetValue(counter);
+}
+
+bool RuntimeCallStats::IsCalledOnTheSameThread() {
+  if (thread_id_.IsValid()) return thread_id_ == ThreadId::Current();
+  thread_id_ = ThreadId::Current();
+  return true;
+}
+
+void RuntimeCallStats::Print() {
+  StdoutStream os;
+  Print(os);
+}
+
+void RuntimeCallStats::Print(std::ostream& os) {
+  RuntimeCallStatEntries entries;
+  if (current_timer_.Value() != nullptr) {
+    current_timer_.Value()->Snapshot();
+  }
+  for (int i = 0; i < kNumberOfCounters; i++) {
+    entries.Add(GetCounter(i));
+  }
+  entries.Print(os);
+}
+
+void RuntimeCallStats::EnumerateCounters(
+    debug::RuntimeCallCounterCallback callback) {
+  if (current_timer_.Value() != nullptr) {
+    current_timer_.Value()->Snapshot();
+  }
+  for (int i = 0; i < kNumberOfCounters; i++) {
+    RuntimeCallCounter* counter = GetCounter(i);
+    callback(counter->name(), counter->count(), counter->time());
+  }
+}
+
+void RuntimeCallStats::Reset() {
+  if (V8_LIKELY(!TracingFlags::is_runtime_stats_enabled())) return;
+
+  // In tracing, we only what to trace the time spent on top level trace events,
+  // if runtime counter stack is not empty, we should clear the whole runtime
+  // counter stack, and then reset counters so that we can dump counters into
+  // top level trace events accurately.
+  while (current_timer_.Value()) {
+    current_timer_.SetValue(current_timer_.Value()->Stop());
+  }
+
+  for (int i = 0; i < kNumberOfCounters; i++) {
+    GetCounter(i)->Reset();
+  }
+
+  in_use_ = true;
+}
+
+void RuntimeCallStats::Dump(v8::tracing::TracedValue* value) {
+  for (int i = 0; i < kNumberOfCounters; i++) {
+    if (GetCounter(i)->count() > 0) GetCounter(i)->Dump(value);
+  }
+  in_use_ = false;
+}
+
+WorkerThreadRuntimeCallStats::WorkerThreadRuntimeCallStats()
+    : isolate_thread_id_(ThreadId::Current()) {}
+
+WorkerThreadRuntimeCallStats::~WorkerThreadRuntimeCallStats() {
+  if (tls_key_) base::Thread::DeleteThreadLocalKey(*tls_key_);
+}
+
+base::Thread::LocalStorageKey WorkerThreadRuntimeCallStats::GetKey() {
+  base::MutexGuard lock(&mutex_);
+  DCHECK(TracingFlags::is_runtime_stats_enabled());
+  if (!tls_key_) tls_key_ = base::Thread::CreateThreadLocalKey();
+  return *tls_key_;
+}
+
+RuntimeCallStats* WorkerThreadRuntimeCallStats::NewTable() {
+  DCHECK(TracingFlags::is_runtime_stats_enabled());
+  // Never create a new worker table on the isolate's main thread.
+  DCHECK_NE(ThreadId::Current(), isolate_thread_id_);
+  std::unique_ptr<RuntimeCallStats> new_table =
+      std::make_unique<RuntimeCallStats>(RuntimeCallStats::kWorkerThread);
+  RuntimeCallStats* result = new_table.get();
+
+  base::MutexGuard lock(&mutex_);
+  tables_.push_back(std::move(new_table));
+  return result;
+}
+
+void WorkerThreadRuntimeCallStats::AddToMainTable(
+    RuntimeCallStats* main_call_stats) {
+  base::MutexGuard lock(&mutex_);
+  for (auto& worker_stats : tables_) {
+    DCHECK_NE(main_call_stats, worker_stats.get());
+    main_call_stats->Add(worker_stats.get());
+    worker_stats->Reset();
+  }
+}
+
+WorkerThreadRuntimeCallStatsScope::WorkerThreadRuntimeCallStatsScope(
+    WorkerThreadRuntimeCallStats* worker_stats)
+    : table_(nullptr) {
+  if (V8_LIKELY(!TracingFlags::is_runtime_stats_enabled())) return;
+
+  table_ = reinterpret_cast<RuntimeCallStats*>(
+      base::Thread::GetThreadLocal(worker_stats->GetKey()));
+  if (table_ == nullptr) {
+    table_ = worker_stats->NewTable();
+    base::Thread::SetThreadLocal(worker_stats->GetKey(), table_);
+  }
+
+  if ((TracingFlags::runtime_stats.load(std::memory_order_relaxed) &
+       v8::tracing::TracingCategoryObserver::ENABLED_BY_TRACING)) {
+    table_->Reset();
+  }
+}
+
+WorkerThreadRuntimeCallStatsScope::~WorkerThreadRuntimeCallStatsScope() {
+  if (V8_LIKELY(table_ == nullptr)) return;
+
+  if ((TracingFlags::runtime_stats.load(std::memory_order_relaxed) &
+       v8::tracing::TracingCategoryObserver::ENABLED_BY_TRACING)) {
+    auto value = v8::tracing::TracedValue::Create();
+    table_->Dump(value.get());
+    TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("v8.runtime_stats"),
+                         "V8.RuntimeStats", TRACE_EVENT_SCOPE_THREAD,
+                         "runtime-call-stats", std::move(value));
+  }
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_RUNTIME_CALL_STATS
diff --git a/chromium/v8/src/logging/runtime-call-stats.h b/chromium/v8/src/logging/runtime-call-stats.h
new file mode 100644
index 00000000000..7593170d865
--- /dev/null
+++ b/chromium/v8/src/logging/runtime-call-stats.h
@@ -0,0 +1,763 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_LOGGING_RUNTIME_CALL_STATS_H_
+#define V8_LOGGING_RUNTIME_CALL_STATS_H_
+
+#include "include/v8.h"
+
+#ifdef V8_RUNTIME_CALL_STATS
+
+#include "src/base/atomic-utils.h"
+#include "src/base/optional.h"
+#include "src/base/platform/elapsed-timer.h"
+#include "src/base/platform/time.h"
+#include "src/builtins/builtins-definitions.h"
+#include "src/debug/debug-interface.h"
+#include "src/execution/thread-id.h"
+#include "src/init/heap-symbols.h"
+#include "src/logging/tracing-flags.h"
+#include "src/runtime/runtime.h"
+#include "src/tracing/traced-value.h"
+#include "src/tracing/tracing-category-observer.h"
+
+#endif  // V8_RUNTIME_CALL_STATS
+
+namespace v8 {
+namespace internal {
+
+#ifdef V8_RUNTIME_CALL_STATS
+
+#define RCS_SCOPE(...) \
+  v8::internal::RuntimeCallTimerScope rcs_timer_scope(__VA_ARGS__)
+
+class RuntimeCallCounter final {
+ public:
+  RuntimeCallCounter() : RuntimeCallCounter(nullptr) {}
+  explicit RuntimeCallCounter(const char* name)
+      : name_(name), count_(0), time_(0) {}
+  V8_NOINLINE void Reset();
+  V8_NOINLINE void Dump(v8::tracing::TracedValue* value);
+  void Add(RuntimeCallCounter* other);
+
+  const char* name() const { return name_; }
+  int64_t count() const { return count_; }
+  base::TimeDelta time() const {
+    return base::TimeDelta::FromMicroseconds(time_);
+  }
+  void Increment() { count_++; }
+  void Add(base::TimeDelta delta) { time_ += delta.InMicroseconds(); }
+
+ private:
+  friend class RuntimeCallStats;
+
+  const char* name_;
+  int64_t count_;
+  // Stored as int64_t so that its initialization can be deferred.
+  int64_t time_;
+};
+
+// RuntimeCallTimer is used to keep track of the stack of currently active
+// timers used for properly measuring the own time of a RuntimeCallCounter.
+class RuntimeCallTimer final {
+ public:
+  RuntimeCallCounter* counter() { return counter_; }
+  void set_counter(RuntimeCallCounter* counter) { counter_ = counter; }
+  RuntimeCallTimer* parent() const { return parent_.Value(); }
+  void set_parent(RuntimeCallTimer* timer) { parent_.SetValue(timer); }
+  const char* name() const { return counter_->name(); }
+
+  inline bool IsStarted() const { return start_ticks_ != base::TimeTicks(); }
+
+  inline void Start(RuntimeCallCounter* counter, RuntimeCallTimer* parent) {
+    DCHECK(!IsStarted());
+    counter_ = counter;
+    parent_.SetValue(parent);
+    if (TracingFlags::runtime_stats.load(std::memory_order_relaxed) ==
+        v8::tracing::TracingCategoryObserver::ENABLED_BY_SAMPLING) {
+      return;
+    }
+    base::TimeTicks now = RuntimeCallTimer::Now();
+    if (parent) parent->Pause(now);
+    Resume(now);
+    DCHECK(IsStarted());
+  }
+
+  void Snapshot();
+
+  inline RuntimeCallTimer* Stop() {
+    if (!IsStarted()) return parent();
+    base::TimeTicks now = RuntimeCallTimer::Now();
+    Pause(now);
+    counter_->Increment();
+    CommitTimeToCounter();
+
+    RuntimeCallTimer* parent_timer = parent();
+    if (parent_timer) {
+      parent_timer->Resume(now);
+    }
+    return parent_timer;
+  }
+
+  // Make the time source configurable for testing purposes.
+  V8_EXPORT_PRIVATE static base::TimeTicks (*Now)();
+
+  // Helper to switch over to CPU time.
+  static base::TimeTicks NowCPUTime();
+
+ private:
+  inline void Pause(base::TimeTicks now) {
+    DCHECK(IsStarted());
+    elapsed_ += (now - start_ticks_);
+    start_ticks_ = base::TimeTicks();
+  }
+
+  inline void Resume(base::TimeTicks now) {
+    DCHECK(!IsStarted());
+    start_ticks_ = now;
+  }
+
+  inline void CommitTimeToCounter() {
+    counter_->Add(elapsed_);
+    elapsed_ = base::TimeDelta();
+  }
+
+  RuntimeCallCounter* counter_ = nullptr;
+  base::AtomicValue<RuntimeCallTimer*> parent_;
+  base::TimeTicks start_ticks_;
+  base::TimeDelta elapsed_;
+};
+
+#define FOR_EACH_GC_COUNTER(V) \
+  TRACER_SCOPES(V)             \
+  TRACER_BACKGROUND_SCOPES(V)
+
+#define FOR_EACH_API_COUNTER(V)                            \
+  V(AccessorPair_New)                                      \
+  V(ArrayBuffer_Cast)                                      \
+  V(ArrayBuffer_Detach)                                    \
+  V(ArrayBuffer_New)                                       \
+  V(ArrayBuffer_NewBackingStore)                           \
+  V(ArrayBuffer_BackingStore_Reallocate)                   \
+  V(Array_CloneElementAt)                                  \
+  V(Array_New)                                             \
+  V(BigInt64Array_New)                                     \
+  V(BigInt_NewFromWords)                                   \
+  V(BigIntObject_BigIntValue)                              \
+  V(BigIntObject_New)                                      \
+  V(BigUint64Array_New)                                    \
+  V(BooleanObject_BooleanValue)                            \
+  V(BooleanObject_New)                                     \
+  V(Context_New)                                           \
+  V(Context_NewRemoteContext)                              \
+  V(DataView_New)                                          \
+  V(Date_New)                                              \
+  V(Date_NumberValue)                                      \
+  V(Debug_Call)                                            \
+  V(debug_GetPrivateMembers)                               \
+  V(Error_New)                                             \
+  V(External_New)                                          \
+  V(Float32Array_New)                                      \
+  V(Float64Array_New)                                      \
+  V(Function_Call)                                         \
+  V(Function_New)                                          \
+  V(Function_FunctionProtoToString)                        \
+  V(Function_NewInstance)                                  \
+  V(FunctionTemplate_GetFunction)                          \
+  V(FunctionTemplate_New)                                  \
+  V(FunctionTemplate_NewRemoteInstance)                    \
+  V(FunctionTemplate_NewWithCache)                         \
+  V(FunctionTemplate_NewWithFastHandler)                   \
+  V(Int16Array_New)                                        \
+  V(Int32Array_New)                                        \
+  V(Int8Array_New)                                         \
+  V(Isolate_DateTimeConfigurationChangeNotification)       \
+  V(Isolate_LocaleConfigurationChangeNotification)         \
+  V(JSON_Parse)                                            \
+  V(JSON_Stringify)                                        \
+  V(Map_AsArray)                                           \
+  V(Map_Clear)                                             \
+  V(Map_Delete)                                            \
+  V(Map_Get)                                               \
+  V(Map_Has)                                               \
+  V(Map_New)                                               \
+  V(Map_Set)                                               \
+  V(Message_GetEndColumn)                                  \
+  V(Message_GetLineNumber)                                 \
+  V(Message_GetSourceLine)                                 \
+  V(Message_GetStartColumn)                                \
+  V(Module_Evaluate)                                       \
+  V(Module_InstantiateModule)                              \
+  V(Module_SetSyntheticModuleExport)                       \
+  V(NumberObject_New)                                      \
+  V(NumberObject_NumberValue)                              \
+  V(Object_CallAsConstructor)                              \
+  V(Object_CallAsFunction)                                 \
+  V(Object_CreateDataProperty)                             \
+  V(Object_DefineOwnProperty)                              \
+  V(Object_DefineProperty)                                 \
+  V(Object_Delete)                                         \
+  V(Object_DeleteProperty)                                 \
+  V(Object_ForceSet)                                       \
+  V(Object_Get)                                            \
+  V(Object_GetOwnPropertyDescriptor)                       \
+  V(Object_GetOwnPropertyNames)                            \
+  V(Object_GetPropertyAttributes)                          \
+  V(Object_GetPropertyNames)                               \
+  V(Object_GetRealNamedProperty)                           \
+  V(Object_GetRealNamedPropertyAttributes)                 \
+  V(Object_GetRealNamedPropertyAttributesInPrototypeChain) \
+  V(Object_GetRealNamedPropertyInPrototypeChain)           \
+  V(Object_Has)                                            \
+  V(Object_HasOwnProperty)                                 \
+  V(Object_HasRealIndexedProperty)                         \
+  V(Object_HasRealNamedCallbackProperty)                   \
+  V(Object_HasRealNamedProperty)                           \
+  V(Object_IsCodeLike)                                     \
+  V(Object_New)                                            \
+  V(Object_ObjectProtoToString)                            \
+  V(Object_Set)                                            \
+  V(Object_SetAccessor)                                    \
+  V(Object_SetIntegrityLevel)                              \
+  V(Object_SetPrivate)                                     \
+  V(Object_SetPrototype)                                   \
+  V(ObjectTemplate_New)                                    \
+  V(ObjectTemplate_NewInstance)                            \
+  V(Object_ToArrayIndex)                                   \
+  V(Object_ToBigInt)                                       \
+  V(Object_ToDetailString)                                 \
+  V(Object_ToInt32)                                        \
+  V(Object_ToInteger)                                      \
+  V(Object_ToNumber)                                       \
+  V(Object_ToObject)                                       \
+  V(Object_ToString)                                       \
+  V(Object_ToUint32)                                       \
+  V(Persistent_New)                                        \
+  V(Private_New)                                           \
+  V(Promise_Catch)                                         \
+  V(Promise_Chain)                                         \
+  V(Promise_HasRejectHandler)                              \
+  V(Promise_Resolver_New)                                  \
+  V(Promise_Resolver_Reject)                               \
+  V(Promise_Resolver_Resolve)                              \
+  V(Promise_Result)                                        \
+  V(Promise_Status)                                        \
+  V(Promise_Then)                                          \
+  V(Proxy_New)                                             \
+  V(RangeError_New)                                        \
+  V(ReferenceError_New)                                    \
+  V(RegExp_Exec)                                           \
+  V(RegExp_New)                                            \
+  V(ScriptCompiler_Compile)                                \
+  V(ScriptCompiler_CompileFunctionInContext)               \
+  V(ScriptCompiler_CompileUnbound)                         \
+  V(Script_Run)                                            \
+  V(Set_Add)                                               \
+  V(Set_AsArray)                                           \
+  V(Set_Clear)                                             \
+  V(Set_Delete)                                            \
+  V(Set_Has)                                               \
+  V(Set_New)                                               \
+  V(SharedArrayBuffer_New)                                 \
+  V(SharedArrayBuffer_NewBackingStore)                     \
+  V(String_Concat)                                         \
+  V(String_NewExternalOneByte)                             \
+  V(String_NewExternalTwoByte)                             \
+  V(String_NewFromOneByte)                                 \
+  V(String_NewFromTwoByte)                                 \
+  V(String_NewFromUtf8)                                    \
+  V(String_NewFromUtf8Literal)                             \
+  V(StringObject_New)                                      \
+  V(StringObject_StringValue)                              \
+  V(String_Write)                                          \
+  V(String_WriteUtf8)                                      \
+  V(Symbol_New)                                            \
+  V(SymbolObject_New)                                      \
+  V(SymbolObject_SymbolValue)                              \
+  V(SyntaxError_New)                                       \
+  V(TracedGlobal_New)                                      \
+  V(TryCatch_StackTrace)                                   \
+  V(TypeError_New)                                         \
+  V(Uint16Array_New)                                       \
+  V(Uint32Array_New)                                       \
+  V(Uint8Array_New)                                        \
+  V(Uint8ClampedArray_New)                                 \
+  V(UnboundScript_GetId)                                   \
+  V(UnboundScript_GetLineNumber)                           \
+  V(UnboundScript_GetName)                                 \
+  V(UnboundScript_GetSourceMappingURL)                     \
+  V(UnboundScript_GetSourceURL)                            \
+  V(ValueDeserializer_ReadHeader)                          \
+  V(ValueDeserializer_ReadValue)                           \
+  V(ValueSerializer_WriteValue)                            \
+  V(Value_Equals)                                          \
+  V(Value_InstanceOf)                                      \
+  V(Value_Int32Value)                                      \
+  V(Value_IntegerValue)                                    \
+  V(Value_NumberValue)                                     \
+  V(Value_TypeOf)                                          \
+  V(Value_Uint32Value)                                     \
+  V(WasmCompileError_New)                                  \
+  V(WasmLinkError_New)                                     \
+  V(WasmRuntimeError_New)                                  \
+  V(WeakMap_Get)                                           \
+  V(WeakMap_New)                                           \
+  V(WeakMap_Set)
+
+#define ADD_THREAD_SPECIFIC_COUNTER(V, Prefix, Suffix) \
+  V(Prefix##Suffix)                                    \
+  V(Prefix##Background##Suffix)
+
+#define FOR_EACH_THREAD_SPECIFIC_COUNTER(V)                                 \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Compile, Analyse)                          \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Compile, Eval)                             \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Compile, Function)                         \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Compile, Ignition)                         \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Compile, IgnitionFinalization)             \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Compile, RewriteReturnResult)              \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Compile, ScopeAnalysis)                    \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Compile, Script)                           \
+                                                                            \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, AllocateFPRegisters)             \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, AllocateGeneralRegisters)        \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, AssembleCode)                    \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, AssignSpillSlots)                \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, BuildLiveRangeBundles)           \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, BuildLiveRanges)                 \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, BytecodeGraphBuilder)            \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, CommitAssignment)                \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, ConnectRanges)                   \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, ControlFlowOptimization)         \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, CSAEarlyOptimization)            \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, CSAOptimization)                 \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, DecideSpillingMode)              \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, DecompressionOptimization)       \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, EarlyOptimization)               \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, EarlyTrimming)                   \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, EffectLinearization)             \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, EscapeAnalysis)                  \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, FinalizeCode)                    \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, FrameElision)                    \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, GenericLowering)                 \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, Inlining)                        \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, JumpThreading)                   \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, MidTierPopulateReferenceMaps)    \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, MidTierRegisterAllocator)        \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, MidTierRegisterOutputDefinition) \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, MidTierSpillSlotAllocator)       \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, LateGraphTrimming)               \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, LateOptimization)                \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, LoadElimination)                 \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, LocateSpillSlots)                \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, LoopExitElimination)             \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, LoopPeeling)                     \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, MachineOperatorOptimization)     \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, MeetRegisterConstraints)         \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, MemoryOptimization)              \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, OptimizeMoves)                   \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, PopulatePointerMaps)             \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, PrintGraph)                      \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, ResolveControlFlow)              \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, ResolvePhis)                     \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize,                                  \
+                              ScheduledEffectControlLinearization)          \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, ScheduledMachineLowering)        \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, Scheduling)                      \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, SelectInstructions)              \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, SimplifiedLowering)              \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, StoreStoreElimination)           \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, TypeAssertions)                  \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, TypedLowering)                   \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, Typer)                           \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, Untyper)                         \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, VerifyGraph)                     \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, WasmBaseOptimization)            \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, WasmInlining)                    \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Optimize, WasmLoopUnrolling)               \
+                                                                            \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Parse, ArrowFunctionLiteral)               \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Parse, FunctionLiteral)                    \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Parse, Program)                            \
+  ADD_THREAD_SPECIFIC_COUNTER(V, PreParse, ArrowFunctionLiteral)            \
+  ADD_THREAD_SPECIFIC_COUNTER(V, PreParse, WithVariableResolution)
+
+#define FOR_EACH_MANUAL_COUNTER(V)             \
+  V(AccessorGetterCallback)                    \
+  V(AccessorSetterCallback)                    \
+  V(ArrayLengthGetter)                         \
+  V(ArrayLengthSetter)                         \
+  V(BoundFunctionLengthGetter)                 \
+  V(BoundFunctionNameGetter)                   \
+  V(CodeGenerationFromStringsCallbacks)        \
+  V(CompileBackgroundCompileTask)              \
+  V(CompileBaseline)                           \
+  V(CompileBaselineVisit)                      \
+  V(CompileBaselinePreVisit)                   \
+  V(CompileCollectSourcePositions)             \
+  V(CompileDeserialize)                        \
+  V(CompileEnqueueOnDispatcher)                \
+  V(CompileFinalizeBackgroundCompileTask)      \
+  V(CompileFinishNowOnDispatcher)              \
+  V(CompileGetFromOptimizedCodeMap)            \
+  V(CompilePublishBackgroundFinalization)      \
+  V(CompileSerialize)                          \
+  V(CompileWaitForDispatcher)                  \
+  V(ConfigureInstance)                         \
+  V(CreateApiFunction)                         \
+  V(DeoptimizeCode)                            \
+  V(DeserializeContext)                        \
+  V(DeserializeIsolate)                        \
+  V(FinalizationRegistryCleanupFromTask)       \
+  V(FunctionCallback)                          \
+  V(FunctionLengthGetter)                      \
+  V(FunctionPrototypeGetter)                   \
+  V(FunctionPrototypeSetter)                   \
+  V(GC_Custom_AllAvailableGarbage)             \
+  V(GC_Custom_IncrementalMarkingObserver)      \
+  V(GC_Custom_SlowAllocateRaw)                 \
+  V(GCEpilogueCallback)                        \
+  V(GCPrologueCallback)                        \
+  V(Genesis)                                   \
+  V(GetCompatibleReceiver)                     \
+  V(GetMoreDataCallback)                       \
+  V(IndexedDefinerCallback)                    \
+  V(IndexedDeleterCallback)                    \
+  V(IndexedDescriptorCallback)                 \
+  V(IndexedEnumeratorCallback)                 \
+  V(IndexedGetterCallback)                     \
+  V(IndexedQueryCallback)                      \
+  V(IndexedSetterCallback)                     \
+  V(InstantiateFunction)                       \
+  V(InstantiateObject)                         \
+  V(Invoke)                                    \
+  V(InvokeApiFunction)                         \
+  V(InvokeApiInterruptCallbacks)               \
+  V(IsCompatibleReceiver)                      \
+  V(IsCompatibleReceiverMap)                   \
+  V(IsTemplateFor)                             \
+  V(JS_Execution)                              \
+  V(Map_SetPrototype)                          \
+  V(Map_TransitionToAccessorProperty)          \
+  V(Map_TransitionToDataProperty)              \
+  V(MessageListenerCallback)                   \
+  V(NamedDefinerCallback)                      \
+  V(NamedDeleterCallback)                      \
+  V(NamedDescriptorCallback)                   \
+  V(NamedEnumeratorCallback)                   \
+  V(NamedGetterCallback)                       \
+  V(NamedQueryCallback)                        \
+  V(NamedSetterCallback)                       \
+  V(Object_DeleteProperty)                     \
+  V(ObjectVerify)                              \
+  V(OptimizeBackgroundDispatcherJob)           \
+  V(OptimizeCode)                              \
+  V(OptimizeConcurrentFinalize)                \
+  V(OptimizeConcurrentPrepare)                 \
+  V(OptimizeFinalizePipelineJob)               \
+  V(OptimizeHeapBrokerInitialization)          \
+  V(OptimizeNonConcurrent)                     \
+  V(OptimizeSerialization)                     \
+  V(OptimizeSerializeMetadata)                 \
+  V(ParseEval)                                 \
+  V(ParseFunction)                             \
+  V(PropertyCallback)                          \
+  V(PrototypeMap_TransitionToAccessorProperty) \
+  V(PrototypeMap_TransitionToDataProperty)     \
+  V(PrototypeObject_DeleteProperty)            \
+  V(ReconfigureToDataProperty)                 \
+  V(UpdateProtector)                           \
+  V(StringLengthGetter)                        \
+  V(TestCounter1)                              \
+  V(TestCounter2)                              \
+  V(TestCounter3)
+
+#define FOR_EACH_HANDLER_COUNTER(V)               \
+  V(KeyedLoadIC_KeyedLoadSloppyArgumentsStub)     \
+  V(KeyedLoadIC_LoadElementDH)                    \
+  V(KeyedLoadIC_LoadIndexedInterceptorStub)       \
+  V(KeyedLoadIC_LoadIndexedStringDH)              \
+  V(KeyedLoadIC_SlowStub)                         \
+  V(KeyedStoreIC_ElementsTransitionAndStoreStub)  \
+  V(KeyedStoreIC_KeyedStoreSloppyArgumentsStub)   \
+  V(KeyedStoreIC_SlowStub)                        \
+  V(KeyedStoreIC_StoreElementStub)                \
+  V(KeyedStoreIC_StoreFastElementStub)            \
+  V(LoadGlobalIC_LoadScriptContextField)          \
+  V(LoadGlobalIC_SlowStub)                        \
+  V(LoadIC_FunctionPrototypeStub)                 \
+  V(LoadIC_HandlerCacheHit_Accessor)              \
+  V(LoadIC_LoadAccessorDH)                        \
+  V(LoadIC_LoadAccessorFromPrototypeDH)           \
+  V(LoadIC_LoadApiGetterFromPrototypeDH)          \
+  V(LoadIC_LoadCallback)                          \
+  V(LoadIC_LoadConstantDH)                        \
+  V(LoadIC_LoadConstantFromPrototypeDH)           \
+  V(LoadIC_LoadFieldDH)                           \
+  V(LoadIC_LoadFieldFromPrototypeDH)              \
+  V(LoadIC_LoadGlobalDH)                          \
+  V(LoadIC_LoadGlobalFromPrototypeDH)             \
+  V(LoadIC_LoadIntegerIndexedExoticDH)            \
+  V(LoadIC_LoadInterceptorDH)                     \
+  V(LoadIC_LoadInterceptorFromPrototypeDH)        \
+  V(LoadIC_LoadNativeDataPropertyDH)              \
+  V(LoadIC_LoadNativeDataPropertyFromPrototypeDH) \
+  V(LoadIC_LoadNonexistentDH)                     \
+  V(LoadIC_LoadNonMaskingInterceptorDH)           \
+  V(LoadIC_LoadNormalDH)                          \
+  V(LoadIC_LoadNormalFromPrototypeDH)             \
+  V(LoadIC_NonReceiver)                           \
+  V(LoadIC_SlowStub)                              \
+  V(LoadIC_StringLength)                          \
+  V(LoadIC_StringWrapperLength)                   \
+  V(StoreGlobalIC_SlowStub)                       \
+  V(StoreGlobalIC_StoreScriptContextField)        \
+  V(StoreIC_HandlerCacheHit_Accessor)             \
+  V(StoreIC_NonReceiver)                          \
+  V(StoreIC_SlowStub)                             \
+  V(StoreIC_StoreAccessorDH)                      \
+  V(StoreIC_StoreAccessorOnPrototypeDH)           \
+  V(StoreIC_StoreApiSetterOnPrototypeDH)          \
+  V(StoreIC_StoreFieldDH)                         \
+  V(StoreIC_StoreGlobalDH)                        \
+  V(StoreIC_StoreGlobalTransitionDH)              \
+  V(StoreIC_StoreInterceptorStub)                 \
+  V(StoreIC_StoreNativeDataPropertyDH)            \
+  V(StoreIC_StoreNativeDataPropertyOnPrototypeDH) \
+  V(StoreIC_StoreNormalDH)                        \
+  V(StoreIC_StoreTransitionDH)                    \
+  V(StoreInArrayLiteralIC_SlowStub)
+
+enum RuntimeCallCounterId {
+#define CALL_RUNTIME_COUNTER(name) kGC_##name,
+  FOR_EACH_GC_COUNTER(CALL_RUNTIME_COUNTER)
+#undef CALL_RUNTIME_COUNTER
+#define CALL_RUNTIME_COUNTER(name) k##name,
+      FOR_EACH_MANUAL_COUNTER(CALL_RUNTIME_COUNTER)
+#undef CALL_RUNTIME_COUNTER
+#define CALL_RUNTIME_COUNTER(name, nargs, ressize) kRuntime_##name,
+          FOR_EACH_INTRINSIC(CALL_RUNTIME_COUNTER)
+#undef CALL_RUNTIME_COUNTER
+#define CALL_BUILTIN_COUNTER(name) kBuiltin_##name,
+              BUILTIN_LIST_C(CALL_BUILTIN_COUNTER)
+#undef CALL_BUILTIN_COUNTER
+#define CALL_BUILTIN_COUNTER(name) kAPI_##name,
+                  FOR_EACH_API_COUNTER(CALL_BUILTIN_COUNTER)
+#undef CALL_BUILTIN_COUNTER
+#define CALL_BUILTIN_COUNTER(name) kHandler_##name,
+                      FOR_EACH_HANDLER_COUNTER(CALL_BUILTIN_COUNTER)
+#undef CALL_BUILTIN_COUNTER
+#define THREAD_SPECIFIC_COUNTER(name) k##name,
+                          FOR_EACH_THREAD_SPECIFIC_COUNTER(
+                              THREAD_SPECIFIC_COUNTER)
+#undef THREAD_SPECIFIC_COUNTER
+                              kNumberOfCounters,
+};
+
+class RuntimeCallStats final {
+ public:
+  enum ThreadType { kMainIsolateThread, kWorkerThread };
+
+  // If kExact is chosen the counter will be use as given. With kThreadSpecific,
+  // if the RuntimeCallStats was created for a worker thread, then the
+  // background specific version of the counter will be used instead.
+  enum CounterMode { kExact, kThreadSpecific };
+
+  explicit V8_EXPORT_PRIVATE RuntimeCallStats(ThreadType thread_type);
+
+  // Starting measuring the time for a function. This will establish the
+  // connection to the parent counter for properly calculating the own times.
+  V8_EXPORT_PRIVATE void Enter(RuntimeCallTimer* timer,
+                               RuntimeCallCounterId counter_id);
+
+  // Leave a scope for a measured runtime function. This will properly add
+  // the time delta to the current_counter and subtract the delta from its
+  // parent.
+  V8_EXPORT_PRIVATE void Leave(RuntimeCallTimer* timer);
+
+  // Set counter id for the innermost measurement. It can be used to refine
+  // event kind when a runtime entry counter is too generic.
+  V8_EXPORT_PRIVATE void CorrectCurrentCounterId(
+      RuntimeCallCounterId counter_id, CounterMode mode = kExact);
+
+  V8_EXPORT_PRIVATE void Reset();
+  // Add all entries from another stats object.
+  void Add(RuntimeCallStats* other);
+  V8_EXPORT_PRIVATE void Print(std::ostream& os);
+  V8_EXPORT_PRIVATE void Print();
+  V8_NOINLINE void Dump(v8::tracing::TracedValue* value);
+
+  V8_EXPORT_PRIVATE void EnumerateCounters(
+      debug::RuntimeCallCounterCallback callback);
+
+  ThreadId thread_id() const { return thread_id_; }
+  RuntimeCallTimer* current_timer() { return current_timer_.Value(); }
+  RuntimeCallCounter* current_counter() { return current_counter_.Value(); }
+  bool InUse() { return in_use_; }
+  bool IsCalledOnTheSameThread();
+
+  V8_EXPORT_PRIVATE bool IsBackgroundThreadSpecificVariant(
+      RuntimeCallCounterId id);
+  V8_EXPORT_PRIVATE bool HasThreadSpecificCounterVariants(
+      RuntimeCallCounterId id);
+
+  // This should only be called for counters with a dual Background variant. If
+  // on the main thread, this just returns the counter. If on a worker thread,
+  // it returns Background variant of the counter.
+  RuntimeCallCounterId CounterIdForThread(RuntimeCallCounterId id) {
+    DCHECK(HasThreadSpecificCounterVariants(id));
+    // All thread specific counters are laid out with the main thread variant
+    // first followed by the background variant.
+    return thread_type_ == kWorkerThread
+               ? static_cast<RuntimeCallCounterId>(id + 1)
+               : id;
+  }
+
+  bool IsCounterAppropriateForThread(RuntimeCallCounterId id) {
+    // TODO(delphick): We should add background-only counters and ensure that
+    // all counters (not just the thread-specific variants) are only invoked on
+    // the correct thread.
+    if (!HasThreadSpecificCounterVariants(id)) return true;
+    return IsBackgroundThreadSpecificVariant(id) ==
+           (thread_type_ == kWorkerThread);
+  }
+
+  static const int kNumberOfCounters =
+      static_cast<int>(RuntimeCallCounterId::kNumberOfCounters);
+  RuntimeCallCounter* GetCounter(RuntimeCallCounterId counter_id) {
+    return &counters_[static_cast<int>(counter_id)];
+  }
+  RuntimeCallCounter* GetCounter(int counter_id) {
+    return &counters_[counter_id];
+  }
+
+ private:
+  // Top of a stack of active timers.
+  base::AtomicValue<RuntimeCallTimer*> current_timer_;
+  // Active counter object associated with current timer.
+  base::AtomicValue<RuntimeCallCounter*> current_counter_;
+  // Used to track nested tracing scopes.
+  bool in_use_;
+  ThreadType thread_type_;
+  ThreadId thread_id_;
+  RuntimeCallCounter counters_[kNumberOfCounters];
+};
+
+class WorkerThreadRuntimeCallStats final {
+ public:
+  WorkerThreadRuntimeCallStats();
+  ~WorkerThreadRuntimeCallStats();
+
+  // Returns the TLS key associated with this WorkerThreadRuntimeCallStats.
+  base::Thread::LocalStorageKey GetKey();
+
+  // Returns a new worker thread runtime call stats table managed by this
+  // WorkerThreadRuntimeCallStats.
+  RuntimeCallStats* NewTable();
+
+  // Adds the counters from the worker thread tables to |main_call_stats|.
+  void AddToMainTable(RuntimeCallStats* main_call_stats);
+
+ private:
+  base::Mutex mutex_;
+  std::vector<std::unique_ptr<RuntimeCallStats>> tables_;
+  base::Optional<base::Thread::LocalStorageKey> tls_key_;
+  // Since this is for creating worker thread runtime-call stats, record the
+  // main thread ID to ensure we never create a worker RCS table for the main
+  // thread.
+  ThreadId isolate_thread_id_;
+};
+
+// Creating a WorkerThreadRuntimeCallStatsScope will provide a thread-local
+// runtime call stats table, and will dump the table to an immediate trace event
+// when it is destroyed.
+class V8_NODISCARD WorkerThreadRuntimeCallStatsScope final {
+ public:
+  explicit WorkerThreadRuntimeCallStatsScope(
+      WorkerThreadRuntimeCallStats* off_thread_stats);
+  ~WorkerThreadRuntimeCallStatsScope();
+
+  RuntimeCallStats* Get() const { return table_; }
+
+ private:
+  RuntimeCallStats* table_;
+};
+
+#define CHANGE_CURRENT_RUNTIME_COUNTER(runtime_call_stats, counter_id) \
+  do {                                                                 \
+    if (V8_UNLIKELY(TracingFlags::is_runtime_stats_enabled()) &&       \
+        runtime_call_stats) {                                          \
+      runtime_call_stats->CorrectCurrentCounterId(counter_id);         \
+    }                                                                  \
+  } while (false)
+
+#define TRACE_HANDLER_STATS(isolate, counter_name) \
+  CHANGE_CURRENT_RUNTIME_COUNTER(                  \
+      isolate->counters()->runtime_call_stats(),   \
+      RuntimeCallCounterId::kHandler_##counter_name)
+
+// A RuntimeCallTimerScopes wraps around a RuntimeCallTimer to measure the
+// the time of C++ scope.
+class V8_NODISCARD RuntimeCallTimerScope {
+ public:
+  inline RuntimeCallTimerScope(Isolate* isolate,
+                               RuntimeCallCounterId counter_id);
+  inline RuntimeCallTimerScope(RuntimeCallStats* stats,
+                               RuntimeCallCounterId counter_id,
+                               RuntimeCallStats::CounterMode mode =
+                                   RuntimeCallStats::CounterMode::kExact) {
+    if (V8_LIKELY(!TracingFlags::is_runtime_stats_enabled() ||
+                  stats == nullptr)) {
+      return;
+    }
+    stats_ = stats;
+    if (mode == RuntimeCallStats::CounterMode::kThreadSpecific) {
+      counter_id = stats->CounterIdForThread(counter_id);
+    }
+
+    DCHECK(stats->IsCounterAppropriateForThread(counter_id));
+    stats_->Enter(&timer_, counter_id);
+  }
+
+  inline ~RuntimeCallTimerScope() {
+    if (V8_UNLIKELY(stats_ != nullptr)) {
+      stats_->Leave(&timer_);
+    }
+  }
+
+  RuntimeCallTimerScope(const RuntimeCallTimerScope&) = delete;
+  RuntimeCallTimerScope& operator=(const RuntimeCallTimerScope&) = delete;
+
+ private:
+  RuntimeCallStats* stats_ = nullptr;
+  RuntimeCallTimer timer_;
+};
+
+#else  // RUNTIME_CALL_STATS
+
+#define RCS_SCOPE(...)
+#define TRACE_HANDLER_STATS(...)
+#define CHANGE_CURRENT_RUNTIME_COUNTER(...)
+
+// Create dummy types to limit code changes
+class WorkerThreadRuntimeCallStats {};
+
+class RuntimeCallStats {
+ public:
+  enum ThreadType { kMainIsolateThread, kWorkerThread };
+  explicit V8_EXPORT_PRIVATE RuntimeCallStats(ThreadType thread_type) {}
+};
+
+class WorkerThreadRuntimeCallStatsScope {
+ public:
+  explicit WorkerThreadRuntimeCallStatsScope(
+      WorkerThreadRuntimeCallStats* off_thread_stats) {}
+  RuntimeCallStats* Get() const { return nullptr; }
+};
+
+#endif  // RUNTIME_CALL_STATS
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_LOGGING_RUNTIME_CALL_STATS_H_
diff --git a/chromium/v8/src/numbers/conversions.cc b/chromium/v8/src/numbers/conversions.cc
index d7c31c2e71c..4a018854dd8 100644
--- a/chromium/v8/src/numbers/conversions.cc
+++ b/chromium/v8/src/numbers/conversions.cc
@@ -182,23 +182,23 @@ enum class Sign { kNegative, kPositive, kNone };
 // ES6 18.2.5 parseInt(string, radix) (with NumberParseIntHelper subclass);
 // and BigInt parsing cases from https://tc39.github.io/proposal-bigint/
 // (with StringToBigIntHelper subclass).
-template <typename LocalIsolate>
+template <typename IsolateT>
 class StringToIntHelper {
  public:
-  StringToIntHelper(LocalIsolate* isolate, Handle<String> subject, int radix)
+  StringToIntHelper(IsolateT* isolate, Handle<String> subject, int radix)
       : isolate_(isolate), subject_(subject), radix_(radix) {
     DCHECK(subject->IsFlat());
   }
 
   // Used for the StringToBigInt operation.
-  StringToIntHelper(LocalIsolate* isolate, Handle<String> subject)
+  StringToIntHelper(IsolateT* isolate, Handle<String> subject)
       : isolate_(isolate), subject_(subject) {
     DCHECK(subject->IsFlat());
   }
 
   // Used for parsing BigInt literals, where the input is a Zone-allocated
   // buffer of one-byte digits, along with an optional radix prefix.
-  StringToIntHelper(LocalIsolate* isolate, const uint8_t* subject, int length)
+  StringToIntHelper(IsolateT* isolate, const uint8_t* subject, int length)
       : isolate_(isolate), raw_one_byte_subject_(subject), length_(length) {}
   virtual ~StringToIntHelper() = default;
 
@@ -239,7 +239,7 @@ class StringToIntHelper {
     return subject_->GetFlatContent(no_gc).ToUC16Vector();
   }
 
-  LocalIsolate* isolate() { return isolate_; }
+  IsolateT* isolate() { return isolate_; }
   int radix() { return radix_; }
   int cursor() { return cursor_; }
   int length() { return length_; }
@@ -254,7 +254,7 @@ class StringToIntHelper {
   template <class Char>
   bool ParseChunkInternal(Char start);
 
-  LocalIsolate* isolate_;
+  IsolateT* isolate_;
   Handle<String> subject_;
   const uint8_t* raw_one_byte_subject_ = nullptr;
   int radix_ = 0;
@@ -267,8 +267,8 @@ class StringToIntHelper {
   State state_ = State::kRunning;
 };
 
-template <typename LocalIsolate>
-void StringToIntHelper<LocalIsolate>::ParseInt() {
+template <typename IsolateT>
+void StringToIntHelper<IsolateT>::ParseInt() {
   {
     DisallowGarbageCollection no_gc;
     if (IsOneByte()) {
@@ -311,10 +311,10 @@ void StringToIntHelper<LocalIsolate>::ParseInt() {
   DCHECK_NE(state_, State::kRunning);
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 template <class Char>
-void StringToIntHelper<LocalIsolate>::DetectRadixInternal(Char current,
-                                                          int length) {
+void StringToIntHelper<IsolateT>::DetectRadixInternal(Char current,
+                                                      int length) {
   Char start = current;
   length_ = length;
   Char end = start + length;
@@ -391,9 +391,9 @@ void StringToIntHelper<LocalIsolate>::DetectRadixInternal(Char current,
   cursor_ = static_cast<int>(current - start);
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 template <class Char>
-bool StringToIntHelper<LocalIsolate>::ParseChunkInternal(Char start) {
+bool StringToIntHelper<IsolateT>::ParseChunkInternal(Char start) {
   const int kChunkSize = 10240;
   Char current = start + cursor_;
   Char end = start + length_;
@@ -860,14 +860,14 @@ double StringToInt(Isolate* isolate, Handle<String> string, int radix) {
   return helper.GetResult();
 }
 
-template <typename LocalIsolate>
-class StringToBigIntHelper : public StringToIntHelper<LocalIsolate> {
+template <typename IsolateT>
+class StringToBigIntHelper : public StringToIntHelper<IsolateT> {
  public:
   enum class Behavior { kStringToBigInt, kLiteral };
 
   // Used for StringToBigInt operation (BigInt constructor and == operator).
-  StringToBigIntHelper(LocalIsolate* isolate, Handle<String> string)
-      : StringToIntHelper<LocalIsolate>(isolate, string),
+  StringToBigIntHelper(IsolateT* isolate, Handle<String> string)
+      : StringToIntHelper<IsolateT>(isolate, string),
         behavior_(Behavior::kStringToBigInt) {
     this->set_allow_binary_and_octal_prefixes();
     this->set_disallow_trailing_junk();
@@ -875,8 +875,8 @@ class StringToBigIntHelper : public StringToIntHelper<LocalIsolate> {
 
   // Used for parsing BigInt literals, where the input is a buffer of
   // one-byte ASCII digits, along with an optional radix prefix.
-  StringToBigIntHelper(LocalIsolate* isolate, const uint8_t* string, int length)
-      : StringToIntHelper<LocalIsolate>(isolate, string, length),
+  StringToBigIntHelper(IsolateT* isolate, const uint8_t* string, int length)
+      : StringToIntHelper<IsolateT>(isolate, string, length),
         behavior_(Behavior::kLiteral) {
     this->set_allow_binary_and_octal_prefixes();
   }
@@ -943,8 +943,8 @@ class StringToBigIntHelper : public StringToIntHelper<LocalIsolate> {
   Behavior behavior_;
 };
 
-template <typename LocalIsolate>
-bool StringToBigIntHelper<LocalIsolate>::CheckTermination() {
+template <typename IsolateT>
+bool StringToBigIntHelper<IsolateT>::CheckTermination() {
   return false;
 }
 
@@ -961,9 +961,9 @@ MaybeHandle<BigInt> StringToBigInt(Isolate* isolate, Handle<String> string) {
   return helper.GetResult();
 }
 
-template <typename LocalIsolate>
-MaybeHandle<BigInt> BigIntLiteral(LocalIsolate* isolate, const char* string) {
-  StringToBigIntHelper<LocalIsolate> helper(
+template <typename IsolateT>
+MaybeHandle<BigInt> BigIntLiteral(IsolateT* isolate, const char* string) {
+  StringToBigIntHelper<IsolateT> helper(
       isolate, reinterpret_cast<const uint8_t*>(string),
       static_cast<int>(strlen(string)));
   return helper.GetResult();
diff --git a/chromium/v8/src/numbers/conversions.h b/chromium/v8/src/numbers/conversions.h
index d4a09e1b20c..935d6f57e28 100644
--- a/chromium/v8/src/numbers/conversions.h
+++ b/chromium/v8/src/numbers/conversions.h
@@ -101,9 +101,9 @@ MaybeHandle<BigInt> StringToBigInt(Isolate* isolate, Handle<String> string);
 //   0x -> hex
 //   0o -> octal
 //   0b -> binary
-template <typename LocalIsolate>
+template <typename IsolateT>
 EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-MaybeHandle<BigInt> BigIntLiteral(LocalIsolate* isolate, const char* string);
+MaybeHandle<BigInt> BigIntLiteral(IsolateT* isolate, const char* string);
 
 const int kDoubleToCStringMinBufferSize = 100;
 
diff --git a/chromium/v8/src/numbers/dtoa.h b/chromium/v8/src/numbers/dtoa.h
index da67c180e8c..cf540f1213a 100644
--- a/chromium/v8/src/numbers/dtoa.h
+++ b/chromium/v8/src/numbers/dtoa.h
@@ -23,9 +23,14 @@ enum DtoaMode {
   DTOA_PRECISION
 };
 
-// The maximal length of digits a double can have in base 10.
-// Note that DoubleToAscii null-terminates its input. So the given buffer should
-// be at least kBase10MaximalLength + 1 characters long.
+// The maximal length of digits a double can have in base 10 as returned by
+// 'DoubleToAscii'. This does neither include sign, decimal point nor exponent.
+// For example DoubleToAscii(-3.5844466002796428e+298, ..., buffer, ...) will
+// fill buffer with the string "35844466002796428", while sign and decimal point
+// position will be provided through additional output arguments.
+// kBase10MaximalLength refers to the maximal length of this string. Note that
+// DoubleToAscii null-terminates its input. So the given buffer should be at
+// least kBase10MaximalLength + 1 characters long.
 const int kBase10MaximalLength = 17;
 
 // Converts the given double 'v' to ASCII.
diff --git a/chromium/v8/src/objects/all-objects-inl.h b/chromium/v8/src/objects/all-objects-inl.h
index 78c239fd773..5a78cefc8d0 100644
--- a/chromium/v8/src/objects/all-objects-inl.h
+++ b/chromium/v8/src/objects/all-objects-inl.h
@@ -52,6 +52,7 @@
 #include "src/objects/lookup-inl.h"
 #include "src/objects/map-inl.h"
 #include "src/objects/maybe-object-inl.h"
+#include "src/objects/megadom-handler-inl.h"
 #include "src/objects/microtask-inl.h"
 #include "src/objects/module-inl.h"
 #include "src/objects/name-inl.h"
diff --git a/chromium/v8/src/objects/allocation-site-inl.h b/chromium/v8/src/objects/allocation-site-inl.h
index d9911bc8266..68e91e68a5a 100644
--- a/chromium/v8/src/objects/allocation-site-inl.h
+++ b/chromium/v8/src/objects/allocation-site-inl.h
@@ -27,6 +27,8 @@ CAST_ACCESSOR(AllocationSite)
 
 ACCESSORS(AllocationSite, transition_info_or_boilerplate, Object,
           kTransitionInfoOrBoilerplateOffset)
+RELEASE_ACQUIRE_ACCESSORS(AllocationSite, transition_info_or_boilerplate,
+                          Object, kTransitionInfoOrBoilerplateOffset)
 ACCESSORS(AllocationSite, nested_site, Object, kNestedSiteOffset)
 INT32_ACCESSORS(AllocationSite, pretenure_data, kPretenureDataOffset)
 INT32_ACCESSORS(AllocationSite, pretenure_create_count,
@@ -41,8 +43,14 @@ JSObject AllocationSite::boilerplate() const {
   return JSObject::cast(transition_info_or_boilerplate());
 }
 
-void AllocationSite::set_boilerplate(JSObject object, WriteBarrierMode mode) {
-  set_transition_info_or_boilerplate(object, mode);
+JSObject AllocationSite::boilerplate(AcquireLoadTag tag) const {
+  DCHECK(PointsToLiteral());
+  return JSObject::cast(transition_info_or_boilerplate(tag));
+}
+
+void AllocationSite::set_boilerplate(JSObject value, ReleaseStoreTag tag,
+                                     WriteBarrierMode mode) {
+  set_transition_info_or_boilerplate(value, tag, mode);
 }
 
 int AllocationSite::transition_info() const {
diff --git a/chromium/v8/src/objects/allocation-site.h b/chromium/v8/src/objects/allocation-site.h
index 437876d94cc..549e82a4da9 100644
--- a/chromium/v8/src/objects/allocation-site.h
+++ b/chromium/v8/src/objects/allocation-site.h
@@ -40,7 +40,9 @@ class AllocationSite : public Struct {
   // Contains either a Smi-encoded bitfield or a boilerplate. If it's a Smi the
   // AllocationSite is for a constructed Array.
   DECL_ACCESSORS(transition_info_or_boilerplate, Object)
-  DECL_ACCESSORS(boilerplate, JSObject)
+  DECL_RELEASE_ACQUIRE_ACCESSORS(transition_info_or_boilerplate, Object)
+  DECL_GETTER(boilerplate, JSObject)
+  DECL_RELEASE_ACQUIRE_ACCESSORS(boilerplate, JSObject)
   DECL_INT_ACCESSORS(transition_info)
 
   // nested_site threads a list of sites that represent nested literals
@@ -68,9 +70,9 @@ class AllocationSite : public Struct {
   bool IsNested();
 
   // transition_info bitfields, for constructed array transition info.
-  using ElementsKindBits = base::BitField<ElementsKind, 0, 5>;
-  using DoNotInlineBit = base::BitField<bool, 5, 1>;
-  // Unused bits 6-30.
+  using ElementsKindBits = base::BitField<ElementsKind, 0, 6>;
+  using DoNotInlineBit = base::BitField<bool, 6, 1>;
+  // Unused bits 7-30.
 
   // Bitfields for pretenure_data
   using MementoFoundCountBits = base::BitField<int, 0, 26>;
diff --git a/chromium/v8/src/objects/api-callbacks.h b/chromium/v8/src/objects/api-callbacks.h
index f5d81dd9861..a55ca5eb62f 100644
--- a/chromium/v8/src/objects/api-callbacks.h
+++ b/chromium/v8/src/objects/api-callbacks.h
@@ -64,6 +64,8 @@ class AccessorInfo : public TorqueGeneratedAccessorInfo<AccessorInfo, Struct> {
   static int AppendUnique(Isolate* isolate, Handle<Object> descriptors,
                           Handle<FixedArray> array, int valid_descriptors);
 
+  DECL_PRINTER(AccessorInfo)
+
  private:
   inline bool HasExpectedReceiverType();
 
diff --git a/chromium/v8/src/objects/arguments.tq b/chromium/v8/src/objects/arguments.tq
index b65464688a7..6f8e02fdbc9 100644
--- a/chromium/v8/src/objects/arguments.tq
+++ b/chromium/v8/src/objects/arguments.tq
@@ -80,7 +80,7 @@ extern shape JSStrictArgumentsObject extends JSArgumentsObject {
 class SloppyArgumentsElements extends FixedArrayBase {
   context: Context;
   arguments: FixedArray|NumberDictionary;
-  @relaxedRead mapped_entries[length]: Smi|TheHole;
+  @cppRelaxedLoad mapped_entries[length]: Smi|TheHole;
 }
 
 macro NewSloppyArgumentsElements<Iterator: type>(
diff --git a/chromium/v8/src/objects/backing-store.cc b/chromium/v8/src/objects/backing-store.cc
index 08288ef62c0..77eaf3a722c 100644
--- a/chromium/v8/src/objects/backing-store.cc
+++ b/chromium/v8/src/objects/backing-store.cc
@@ -37,6 +37,14 @@ namespace {
 constexpr size_t kPlatformMaxPages =
     std::numeric_limits<size_t>::max() / wasm::kWasmPageSize;
 
+constexpr uint64_t kNegativeGuardSize = uint64_t{2} * GB;
+
+#if V8_TARGET_ARCH_64_BIT
+constexpr uint64_t kFullGuardSize = uint64_t{10} * GB;
+#endif
+
+#endif  // V8_ENABLE_WEBASSEMBLY
+
 #if V8_TARGET_ARCH_MIPS64
 // MIPS64 has a user space of 2^40 bytes on most processors,
 // address space limits needs to be smaller.
@@ -50,12 +58,6 @@ constexpr size_t kAddressSpaceLimit = 0x10100000000L;  // 1 TiB + 4 GiB
 constexpr size_t kAddressSpaceLimit = 0xC0000000;  // 3 GiB
 #endif
 
-constexpr uint64_t kNegativeGuardSize = uint64_t{2} * GB;
-
-#if V8_TARGET_ARCH_64_BIT
-constexpr uint64_t kFullGuardSize = uint64_t{10} * GB;
-#endif
-
 std::atomic<uint64_t> reserved_address_space_{0};
 
 // Allocation results are reported to UMA
@@ -75,7 +77,7 @@ enum class AllocationStatus {
 base::AddressRegion GetReservedRegion(bool has_guard_regions,
                                       void* buffer_start,
                                       size_t byte_capacity) {
-#if V8_TARGET_ARCH_64_BIT
+#if V8_TARGET_ARCH_64_BIT && V8_ENABLE_WEBASSEMBLY
   if (has_guard_regions) {
     // Guard regions always look like this:
     // |xxx(2GiB)xxx|.......(4GiB)..xxxxx|xxxxxx(4GiB)xxxxxx|
@@ -97,7 +99,7 @@ base::AddressRegion GetReservedRegion(bool has_guard_regions,
 }
 
 size_t GetReservationSize(bool has_guard_regions, size_t byte_capacity) {
-#if V8_TARGET_ARCH_64_BIT
+#if V8_TARGET_ARCH_64_BIT && V8_ENABLE_WEBASSEMBLY
   if (has_guard_regions) return kFullGuardSize;
 #else
   DCHECK(!has_guard_regions);
@@ -110,7 +112,6 @@ void RecordStatus(Isolate* isolate, AllocationStatus status) {
   isolate->counters()->wasm_memory_allocation_result()->AddSample(
       static_cast<int>(status));
 }
-#endif  // V8_ENABLE_WEBASSEMBLY
 
 inline void DebugCheckZero(void* start, size_t byte_length) {
 #if DEBUG
@@ -160,6 +161,8 @@ BackingStore::~BackingStore() {
 
 #if V8_ENABLE_WEBASSEMBLY
   if (is_wasm_memory_) {
+    // TODO(v8:11111): RAB / GSAB - Wasm integration.
+    DCHECK(!is_resizable_);
     DCHECK(free_on_destruct_);
     DCHECK(!custom_deleter_);
     size_t reservation_size =
@@ -189,6 +192,23 @@ BackingStore::~BackingStore() {
   }
 #endif  // V8_ENABLE_WEBASSEMBLY
 
+  if (is_resizable_) {
+    DCHECK(free_on_destruct_);
+    DCHECK(!custom_deleter_);
+    size_t reservation_size =
+        GetReservationSize(has_guard_regions_, byte_capacity_);
+    auto region =
+        GetReservedRegion(has_guard_regions_, buffer_start_, byte_capacity_);
+
+    bool pages_were_freed =
+        region.size() == 0 /* no need to free any pages */ ||
+        FreePages(GetPlatformPageAllocator(),
+                  reinterpret_cast<void*>(region.begin()), region.size());
+    CHECK(pages_were_freed);
+    BackingStore::ReleaseReservation(reservation_size);
+    Clear();
+    return;
+  }
   if (custom_deleter_) {
     DCHECK(free_on_destruct_);
     TRACE_BS("BS:custom deleter bs=%p mem=%p (length=%zu, capacity=%zu)\n",
@@ -252,15 +272,16 @@ std::unique_ptr<BackingStore> BackingStore::Allocate(
     }
   }
 
-  auto result = new BackingStore(buffer_start,  // start
-                                 byte_length,   // length
-                                 byte_length,   // capacity
-                                 shared,        // shared
-                                 false,         // is_wasm_memory
-                                 true,          // free_on_destruct
-                                 false,         // has_guard_regions
-                                 false,         // custom_deleter
-                                 false);        // empty_deleter
+  auto result = new BackingStore(buffer_start,                  // start
+                                 byte_length,                   // length
+                                 byte_length,                   // capacity
+                                 shared,                        // shared
+                                 ResizableFlag::kNotResizable,  // resizable
+                                 false,   // is_wasm_memory
+                                 true,    // free_on_destruct
+                                 false,   // has_guard_regions
+                                 false,   // custom_deleter
+                                 false);  // empty_deleter
 
   TRACE_BS("BS:alloc  bs=%p mem=%p (length=%zu)\n", result,
            result->buffer_start(), byte_length);
@@ -281,6 +302,27 @@ void BackingStore::SetAllocatorFromIsolate(Isolate* isolate) {
 }
 
 #if V8_ENABLE_WEBASSEMBLY
+// Allocate a backing store for a Wasm memory. Always use the page allocator
+// and add guard regions.
+std::unique_ptr<BackingStore> BackingStore::TryAllocateWasmMemory(
+    Isolate* isolate, size_t initial_pages, size_t maximum_pages,
+    SharedFlag shared) {
+  // Compute size of reserved memory.
+  size_t engine_max_pages = wasm::max_mem_pages();
+  maximum_pages = std::min(engine_max_pages, maximum_pages);
+
+  auto result = TryAllocateAndPartiallyCommitMemory(
+      isolate, initial_pages * wasm::kWasmPageSize, wasm::kWasmPageSize,
+      initial_pages, maximum_pages, true, shared);
+  // Shared Wasm memories need an anchor for the memory object list.
+  if (result && shared == SharedFlag::kShared) {
+    result->type_specific_data_.shared_wasm_memory_data =
+        new SharedWasmMemoryData();
+  }
+  return result;
+}
+#endif  // V8_ENABLE_WEBASSEMBLY
+
 bool BackingStore::ReserveAddressSpace(uint64_t num_bytes) {
   uint64_t reservation_limit = kAddressSpaceLimit;
   uint64_t old_count = reserved_address_space_.load(std::memory_order_relaxed);
@@ -300,17 +342,21 @@ void BackingStore::ReleaseReservation(uint64_t num_bytes) {
   DCHECK_LE(num_bytes, old_reserved);
 }
 
-// Allocate a backing store for a Wasm memory. Always use the page allocator
-// and add guard regions.
-std::unique_ptr<BackingStore> BackingStore::TryAllocateWasmMemory(
-    Isolate* isolate, size_t initial_pages, size_t maximum_pages,
+std::unique_ptr<BackingStore> BackingStore::TryAllocateAndPartiallyCommitMemory(
+    Isolate* isolate, size_t byte_length, size_t page_size,
+    size_t initial_pages, size_t maximum_pages, bool is_wasm_memory,
     SharedFlag shared) {
+  // Enforce engine limitation on the maximum number of pages.
+  if (maximum_pages > std::numeric_limits<size_t>::max() / page_size) {
+    return nullptr;
+  }
+
   // Cannot reserve 0 pages on some OSes.
   if (maximum_pages == 0) maximum_pages = 1;
 
   TRACE_BS("BSw:try   %zu pages, %zu max\n", initial_pages, maximum_pages);
 
-  bool guards = trap_handler::IsTrapHandlerEnabled();
+  bool guards = is_wasm_memory && trap_handler::IsTrapHandlerEnabled();
 
   // For accounting purposes, whether a GC was necessary.
   bool did_retry = false;
@@ -329,16 +375,7 @@ std::unique_ptr<BackingStore> BackingStore::TryAllocateWasmMemory(
     return false;
   };
 
-  // Compute size of reserved memory.
-
-  size_t engine_max_pages = wasm::max_mem_pages();
-  maximum_pages = std::min(engine_max_pages, maximum_pages);
-  // If the platform doesn't support so many pages, attempting to allocate
-  // is guaranteed to fail, so we don't even try.
-  if (maximum_pages > kPlatformMaxPages) return {};
-  CHECK_LE(maximum_pages,
-           std::numeric_limits<size_t>::max() / wasm::kWasmPageSize);
-  size_t byte_capacity = maximum_pages * wasm::kWasmPageSize;
+  size_t byte_capacity = maximum_pages * page_size;
   size_t reservation_size = GetReservationSize(guards, byte_capacity);
 
   //--------------------------------------------------------------------------
@@ -366,7 +403,7 @@ std::unique_ptr<BackingStore> BackingStore::TryAllocateWasmMemory(
   auto allocate_pages = [&] {
     allocation_base =
         AllocatePages(GetPlatformPageAllocator(), nullptr, reservation_size,
-                      wasm::kWasmPageSize, PageAllocator::kNoAccess);
+                      page_size, PageAllocator::kNoAccess);
     return allocation_base != nullptr;
   };
   if (!gc_retry(allocate_pages)) {
@@ -379,23 +416,27 @@ std::unique_ptr<BackingStore> BackingStore::TryAllocateWasmMemory(
 
   // Get a pointer to the start of the buffer, skipping negative guard region
   // if necessary.
+#if V8_ENABLE_WEBASSEMBLY
   byte* buffer_start = reinterpret_cast<byte*>(allocation_base) +
                        (guards ? kNegativeGuardSize : 0);
-
+#else
+  DCHECK(!guards);
+  byte* buffer_start = reinterpret_cast<byte*>(allocation_base);
+#endif
   //--------------------------------------------------------------------------
   // 3. Commit the initial pages (allow read/write).
   //--------------------------------------------------------------------------
-  size_t byte_length = initial_pages * wasm::kWasmPageSize;
+  size_t committed_byte_length = initial_pages * page_size;
   auto commit_memory = [&] {
-    return byte_length == 0 ||
-           SetPermissions(GetPlatformPageAllocator(), buffer_start, byte_length,
-                          PageAllocator::kReadWrite);
+    return committed_byte_length == 0 ||
+           SetPermissions(GetPlatformPageAllocator(), buffer_start,
+                          committed_byte_length, PageAllocator::kReadWrite);
   };
   if (!gc_retry(commit_memory)) {
     TRACE_BS("BSw:try   failed to set permissions (%p, %zu)\n", buffer_start,
-             byte_length);
+             committed_byte_length);
     // SetPermissions put us over the process memory limit.
-    V8::FatalProcessOutOfMemory(nullptr, "BackingStore::AllocateWasmMemory()");
+    V8::FatalProcessOutOfMemory(nullptr, "BackingStore::AllocateMemory()");
   }
 
   DebugCheckZero(buffer_start, byte_length);  // touch the bytes.
@@ -403,30 +444,29 @@ std::unique_ptr<BackingStore> BackingStore::TryAllocateWasmMemory(
   RecordStatus(isolate, did_retry ? AllocationStatus::kSuccessAfterRetry
                                   : AllocationStatus::kSuccess);
 
-  auto result = new BackingStore(buffer_start,   // start
-                                 byte_length,    // length
-                                 byte_capacity,  // capacity
-                                 shared,         // shared
-                                 true,           // is_wasm_memory
-                                 true,           // free_on_destruct
-                                 guards,         // has_guard_regions
-                                 false,          // custom_deleter
-                                 false);         // empty_deleter
+  ResizableFlag resizable =
+      is_wasm_memory ? ResizableFlag::kNotResizable : ResizableFlag::kResizable;
+
+  auto result = new BackingStore(buffer_start,    // start
+                                 byte_length,     // length
+                                 byte_capacity,   // capacity
+                                 shared,          // shared
+                                 resizable,       // resizable
+                                 is_wasm_memory,  // is_wasm_memory
+                                 true,            // free_on_destruct
+                                 guards,          // has_guard_regions
+                                 false,           // custom_deleter
+                                 false);          // empty_deleter
 
   TRACE_BS(
       "BSw:alloc bs=%p mem=%p (length=%zu, capacity=%zu, reservation=%zu)\n",
       result, result->buffer_start(), byte_length, byte_capacity,
       reservation_size);
 
-  // Shared Wasm memories need an anchor for the memory object list.
-  if (shared == SharedFlag::kShared) {
-    result->type_specific_data_.shared_wasm_memory_data =
-        new SharedWasmMemoryData();
-  }
-
   return std::unique_ptr<BackingStore>(result);
 }
 
+#if V8_ENABLE_WEBASSEMBLY
 // Allocate a backing store for a Wasm memory. Always use the page allocator
 // and add guard regions.
 std::unique_ptr<BackingStore> BackingStore::AllocateWasmMemory(
@@ -583,18 +623,102 @@ void BackingStore::UpdateSharedWasmMemoryObjects(Isolate* isolate) {
 }
 #endif  // V8_ENABLE_WEBASSEMBLY
 
+// Commit already reserved memory (for RAB backing stores (not shared)).
+BackingStore::ResizeOrGrowResult BackingStore::ResizeInPlace(
+    Isolate* isolate, size_t new_byte_length, size_t new_committed_length) {
+  DCHECK_LE(new_byte_length, new_committed_length);
+  DCHECK(!is_shared());
+
+  if (new_byte_length < byte_length_) {
+    // TOOO(v8:11111): Figure out a strategy for shrinking - when do we
+    // un-commit the memory?
+
+    // Zero the memory so that in case the buffer is grown later, we have
+    // zeroed the contents already.
+    memset(reinterpret_cast<byte*>(buffer_start_) + new_byte_length, 0,
+           byte_length_ - new_byte_length);
+
+    // Changing the byte length wouldn't strictly speaking be needed, since
+    // the JSArrayBuffer already stores the updated length. This is to keep
+    // the BackingStore and JSArrayBuffer in sync.
+    byte_length_ = new_byte_length;
+    return kSuccess;
+  }
+  if (new_byte_length == byte_length_) {
+    // i::SetPermissions with size 0 fails on some platforms, so special
+    // handling for the case byte_length_ == new_byte_length == 0 is required.
+    return kSuccess;
+  }
+
+  // Try to adjust the permissions on the memory.
+  if (!i::SetPermissions(GetPlatformPageAllocator(), buffer_start_,
+                         new_committed_length, PageAllocator::kReadWrite)) {
+    return kFailure;
+  }
+
+  // Do per-isolate accounting for non-shared backing stores.
+  DCHECK(free_on_destruct_);
+  reinterpret_cast<v8::Isolate*>(isolate)
+      ->AdjustAmountOfExternalAllocatedMemory(new_byte_length - byte_length_);
+  byte_length_ = new_byte_length;
+  return kSuccess;
+}
+
+// Commit already reserved memory (for GSAB backing stores (shared)).
+BackingStore::ResizeOrGrowResult BackingStore::GrowInPlace(
+    Isolate* isolate, size_t new_byte_length, size_t new_committed_length) {
+  DCHECK_LE(new_byte_length, new_committed_length);
+  DCHECK(is_shared());
+  // See comment in GrowWasmMemoryInPlace.
+  // GrowableSharedArrayBuffer.prototype.grow can be called from several
+  // threads. If two threads try to grow() in a racy way, the spec allows the
+  // larger grow to throw also if the smaller grow succeeds first. The
+  // implementation below doesn't throw in that case - instead, it retries and
+  // succeeds. If the larger grow finishes first though, the smaller grow must
+  // throw.
+  size_t old_byte_length = byte_length_.load(std::memory_order_seq_cst);
+  while (true) {
+    if (new_byte_length < old_byte_length) {
+      // The caller checks for the new_byte_length < old_byte_length_ case. This
+      // can only happen if another thread grew the memory after that.
+      return kRace;
+    }
+    if (new_byte_length == old_byte_length) {
+      // i::SetPermissions with size 0 fails on some platforms, so special
+      // handling for the case old_byte_length == new_byte_length == 0 is
+      // required.
+      return kSuccess;
+    }
+
+    // Try to adjust the permissions on the memory.
+    if (!i::SetPermissions(GetPlatformPageAllocator(), buffer_start_,
+                           new_committed_length, PageAllocator::kReadWrite)) {
+      return kFailure;
+    }
+
+    // compare_exchange_weak updates old_byte_length.
+    if (byte_length_.compare_exchange_weak(old_byte_length, new_byte_length,
+                                           std::memory_order_seq_cst)) {
+      // Successfully updated both the length and permissions.
+      break;
+    }
+  }
+  return kSuccess;
+}
+
 std::unique_ptr<BackingStore> BackingStore::WrapAllocation(
     Isolate* isolate, void* allocation_base, size_t allocation_length,
     SharedFlag shared, bool free_on_destruct) {
-  auto result = new BackingStore(allocation_base,    // start
-                                 allocation_length,  // length
-                                 allocation_length,  // capacity
-                                 shared,             // shared
-                                 false,              // is_wasm_memory
-                                 free_on_destruct,   // free_on_destruct
-                                 false,              // has_guard_regions
-                                 false,              // custom_deleter
-                                 false);             // empty_deleter
+  auto result = new BackingStore(allocation_base,               // start
+                                 allocation_length,             // length
+                                 allocation_length,             // capacity
+                                 shared,                        // shared
+                                 ResizableFlag::kNotResizable,  // resizable
+                                 false,             // is_wasm_memory
+                                 free_on_destruct,  // free_on_destruct
+                                 false,             // has_guard_regions
+                                 false,             // custom_deleter
+                                 false);            // empty_deleter
   result->SetAllocatorFromIsolate(isolate);
   TRACE_BS("BS:wrap   bs=%p mem=%p (length=%zu)\n", result,
            result->buffer_start(), result->byte_length());
@@ -606,10 +730,11 @@ std::unique_ptr<BackingStore> BackingStore::WrapAllocation(
     v8::BackingStore::DeleterCallback deleter, void* deleter_data,
     SharedFlag shared) {
   bool is_empty_deleter = (deleter == v8::BackingStore::EmptyDeleter);
-  auto result = new BackingStore(allocation_base,    // start
-                                 allocation_length,  // length
-                                 allocation_length,  // capacity
-                                 shared,             // shared
+  auto result = new BackingStore(allocation_base,               // start
+                                 allocation_length,             // length
+                                 allocation_length,             // capacity
+                                 shared,                        // shared
+                                 ResizableFlag::kNotResizable,  // resizable
                                  false,              // is_wasm_memory
                                  true,               // free_on_destruct
                                  false,              // has_guard_regions
@@ -623,15 +748,16 @@ std::unique_ptr<BackingStore> BackingStore::WrapAllocation(
 
 std::unique_ptr<BackingStore> BackingStore::EmptyBackingStore(
     SharedFlag shared) {
-  auto result = new BackingStore(nullptr,  // start
-                                 0,        // length
-                                 0,        // capacity
-                                 shared,   // shared
-                                 false,    // is_wasm_memory
-                                 true,     // free_on_destruct
-                                 false,    // has_guard_regions
-                                 false,    // custom_deleter
-                                 false);   // empty_deleter
+  auto result = new BackingStore(nullptr,                       // start
+                                 0,                             // length
+                                 0,                             // capacity
+                                 shared,                        // shared
+                                 ResizableFlag::kNotResizable,  // resizable
+                                 false,   // is_wasm_memory
+                                 true,    // free_on_destruct
+                                 false,   // has_guard_regions
+                                 false,   // custom_deleter
+                                 false);  // empty_deleter
 
   return std::unique_ptr<BackingStore>(result);
 }
diff --git a/chromium/v8/src/objects/backing-store.h b/chromium/v8/src/objects/backing-store.h
index eb879d5e8ad..5598388d3b9 100644
--- a/chromium/v8/src/objects/backing-store.h
+++ b/chromium/v8/src/objects/backing-store.h
@@ -21,6 +21,9 @@ class WasmMemoryObject;
 // Whether the backing store is shared or not.
 enum class SharedFlag : uint8_t { kNotShared, kShared };
 
+// Whether the backing store is resizable or not.
+enum class ResizableFlag : uint8_t { kNotResizable, kResizable };
+
 // Whether the backing store memory is initialied to zero or not.
 enum class InitializedFlag : uint8_t { kUninitialized, kZeroInitialized };
 
@@ -56,6 +59,12 @@ class V8_EXPORT_PRIVATE BackingStore : public BackingStoreBase {
                                                           SharedFlag shared);
 #endif  // V8_ENABLE_WEBASSEMBLY
 
+  // Tries to allocate `maximum_pages` of memory and commit `initial_pages`.
+  static std::unique_ptr<BackingStore> TryAllocateAndPartiallyCommitMemory(
+      Isolate* isolate, size_t byte_length, size_t page_size,
+      size_t initial_pages, size_t maximum_pages, bool is_wasm_memory,
+      SharedFlag shared);
+
   // Create a backing store that wraps existing allocated memory.
   // If {free_on_destruct} is {true}, the memory will be freed using the
   // ArrayBufferAllocator::Free() callback when this backing store is
@@ -77,15 +86,24 @@ class V8_EXPORT_PRIVATE BackingStore : public BackingStoreBase {
 
   // Accessors.
   void* buffer_start() const { return buffer_start_; }
-  size_t byte_length() const {
-    return byte_length_.load(std::memory_order_relaxed);
+  size_t byte_length(
+      std::memory_order memory_order = std::memory_order_relaxed) const {
+    return byte_length_.load(memory_order);
   }
   size_t byte_capacity() const { return byte_capacity_; }
   bool is_shared() const { return is_shared_; }
+  bool is_resizable() const { return is_resizable_; }
   bool is_wasm_memory() const { return is_wasm_memory_; }
   bool has_guard_regions() const { return has_guard_regions_; }
   bool free_on_destruct() const { return free_on_destruct_; }
 
+  enum ResizeOrGrowResult { kSuccess, kFailure, kRace };
+
+  ResizeOrGrowResult ResizeInPlace(Isolate* isolate, size_t new_byte_length,
+                                   size_t new_committed_length);
+  ResizeOrGrowResult GrowInPlace(Isolate* isolate, size_t new_byte_length,
+                                 size_t new_committed_length);
+
   // Wrapper around ArrayBuffer::Allocator::Reallocate.
   bool Reallocate(Isolate* isolate, size_t new_byte_length);
 
@@ -111,12 +129,6 @@ class V8_EXPORT_PRIVATE BackingStore : public BackingStoreBase {
   static void BroadcastSharedWasmMemoryGrow(Isolate* isolate,
                                             std::shared_ptr<BackingStore>);
 
-  // TODO(wasm): address space limitations should be enforced in page alloc.
-  // These methods enforce a limit on the total amount of address space,
-  // which is used for both backing stores and wasm memory.
-  static bool ReserveAddressSpace(uint64_t num_bytes);
-  static void ReleaseReservation(uint64_t num_bytes);
-
   // Remove all memory objects in the given isolate that refer to this
   // backing store.
   static void RemoveSharedWasmMemoryObjects(Isolate* isolate);
@@ -125,6 +137,12 @@ class V8_EXPORT_PRIVATE BackingStore : public BackingStoreBase {
   static void UpdateSharedWasmMemoryObjects(Isolate* isolate);
 #endif  // V8_ENABLE_WEBASSEMBLY
 
+  // TODO(wasm): address space limitations should be enforced in page alloc.
+  // These methods enforce a limit on the total amount of address space,
+  // which is used for both backing stores and wasm memory.
+  static bool ReserveAddressSpace(uint64_t num_bytes);
+  static void ReleaseReservation(uint64_t num_bytes);
+
   // Returns the size of the external memory owned by this backing store.
   // It is used for triggering GCs based on the external memory pressure.
   size_t PerIsolateAccountingLength() {
@@ -148,19 +166,26 @@ class V8_EXPORT_PRIVATE BackingStore : public BackingStoreBase {
   friend class GlobalBackingStoreRegistry;
 
   BackingStore(void* buffer_start, size_t byte_length, size_t byte_capacity,
-               SharedFlag shared, bool is_wasm_memory, bool free_on_destruct,
-               bool has_guard_regions, bool custom_deleter, bool empty_deleter)
+               SharedFlag shared, ResizableFlag resizable, bool is_wasm_memory,
+               bool free_on_destruct, bool has_guard_regions,
+               bool custom_deleter, bool empty_deleter)
       : buffer_start_(buffer_start),
         byte_length_(byte_length),
         byte_capacity_(byte_capacity),
         is_shared_(shared == SharedFlag::kShared),
+        is_resizable_(resizable == ResizableFlag::kResizable),
         is_wasm_memory_(is_wasm_memory),
         holds_shared_ptr_to_allocator_(false),
         free_on_destruct_(free_on_destruct),
         has_guard_regions_(has_guard_regions),
         globally_registered_(false),
         custom_deleter_(custom_deleter),
-        empty_deleter_(empty_deleter) {}
+        empty_deleter_(empty_deleter) {
+    // TODO(v8:11111): RAB / GSAB - Wasm integration.
+    DCHECK_IMPLIES(is_wasm_memory_, !is_resizable_);
+    DCHECK_IMPLIES(is_resizable_, !custom_deleter_);
+    DCHECK_IMPLIES(is_resizable_, free_on_destruct_);
+  }
   BackingStore(const BackingStore&) = delete;
   BackingStore& operator=(const BackingStore&) = delete;
   void SetAllocatorFromIsolate(Isolate* isolate);
@@ -199,6 +224,8 @@ class V8_EXPORT_PRIVATE BackingStore : public BackingStoreBase {
   } type_specific_data_;
 
   bool is_shared_ : 1;
+  // Backing stores for (Resizable|GrowableShared)ArrayBuffer
+  bool is_resizable_ : 1;
   bool is_wasm_memory_ : 1;
   bool holds_shared_ptr_to_allocator_ : 1;
   bool free_on_destruct_ : 1;
diff --git a/chromium/v8/src/objects/bigint.cc b/chromium/v8/src/objects/bigint.cc
index cffac5af8e1..9614d4d1461 100644
--- a/chromium/v8/src/objects/bigint.cc
+++ b/chromium/v8/src/objects/bigint.cc
@@ -51,21 +51,20 @@ class MutableBigInt : public FreshlyAllocatedBigInt {
   static void Canonicalize(MutableBigInt result);
 
   // Allocation helpers.
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   static MaybeHandle<MutableBigInt> New(
-      LocalIsolate* isolate, int length,
+      IsolateT* isolate, int length,
       AllocationType allocation = AllocationType::kYoung);
   static Handle<BigInt> NewFromInt(Isolate* isolate, int value);
   static Handle<BigInt> NewFromDouble(Isolate* isolate, double value);
   void InitializeDigits(int length, byte value = 0);
   static Handle<MutableBigInt> Copy(Isolate* isolate,
                                     Handle<BigIntBase> source);
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   static Handle<BigInt> Zero(
-      LocalIsolate* isolate,
-      AllocationType allocation = AllocationType::kYoung) {
+      IsolateT* isolate, AllocationType allocation = AllocationType::kYoung) {
     // TODO(jkummerow): Consider caching a canonical zero-BigInt.
-    return MakeImmutable<LocalIsolate>(
+    return MakeImmutable<IsolateT>(
         New(isolate, 0, allocation).ToHandleChecked());
   }
 
@@ -136,10 +135,6 @@ class MutableBigInt : public FreshlyAllocatedBigInt {
       Isolate* isolate, Handle<BigIntBase> x, Handle<BigIntBase> y,
       MutableBigInt result_storage = MutableBigInt());
 
-  static void MultiplyAccumulate(Handle<BigIntBase> multiplicand,
-                                 digit_t multiplier,
-                                 Handle<MutableBigInt> accumulator,
-                                 int accumulator_index);
   static void InternalMultiplyAdd(BigIntBase source, digit_t factor,
                                   digit_t summand, int n, MutableBigInt result);
   void InplaceMultiplyAdd(uintptr_t factor, uintptr_t summand);
@@ -211,7 +206,7 @@ class MutableBigInt : public FreshlyAllocatedBigInt {
     bitfield = SignBits::update(bitfield, new_sign);
     RELAXED_WRITE_INT32_FIELD(*this, kBitfieldOffset, bitfield);
   }
-  inline void synchronized_set_length(int new_length) {
+  inline void set_length(int new_length, ReleaseStoreTag) {
     int32_t bitfield = RELAXED_READ_INT32_FIELD(*this, kBitfieldOffset);
     bitfield = LengthBits::update(bitfield, new_length);
     RELEASE_WRITE_INT32_FIELD(*this, kBitfieldOffset, bitfield);
@@ -243,14 +238,25 @@ NEVER_READ_ONLY_SPACE_IMPL(MutableBigInt)
 #include "src/base/platform/wrappers.h"
 #include "src/objects/object-macros-undef.h"
 
-struct GetDigits : bigint::Digits {
-  explicit GetDigits(Handle<BigIntBase> bigint) : GetDigits(*bigint) {}
-  explicit GetDigits(BigIntBase bigint)
-      : bigint::Digits(
-            reinterpret_cast<bigint::digit_t*>(
-                bigint.ptr() + BigIntBase::kDigitsOffset - kHeapObjectTag),
-            bigint.length()) {}
-};
+bigint::Digits GetDigits(BigIntBase bigint) {
+  return bigint::Digits(
+      reinterpret_cast<bigint::digit_t*>(
+          bigint.ptr() + BigIntBase::kDigitsOffset - kHeapObjectTag),
+      bigint.length());
+}
+bigint::Digits GetDigits(Handle<BigIntBase> bigint) {
+  return GetDigits(*bigint);
+}
+
+bigint::RWDigits GetRWDigits(MutableBigInt bigint) {
+  return bigint::RWDigits(
+      reinterpret_cast<bigint::digit_t*>(
+          bigint.ptr() + BigIntBase::kDigitsOffset - kHeapObjectTag),
+      bigint.length());
+}
+bigint::RWDigits GetRWDigits(Handle<MutableBigInt> bigint) {
+  return GetRWDigits(*bigint);
+}
 
 template <typename T, typename Isolate>
 MaybeHandle<T> ThrowBigIntTooBig(Isolate* isolate) {
@@ -266,8 +272,8 @@ MaybeHandle<T> ThrowBigIntTooBig(Isolate* isolate) {
   THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kBigIntTooBig), T);
 }
 
-template <typename LocalIsolate>
-MaybeHandle<MutableBigInt> MutableBigInt::New(LocalIsolate* isolate, int length,
+template <typename IsolateT>
+MaybeHandle<MutableBigInt> MutableBigInt::New(IsolateT* isolate, int length,
                                               AllocationType allocation) {
   if (length > BigInt::kMaxLength) {
     return ThrowBigIntTooBig<MutableBigInt>(isolate);
@@ -390,7 +396,7 @@ MaybeHandle<BigInt> MutableBigInt::MakeImmutable(
   return MakeImmutable(result);
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<BigInt> MutableBigInt::MakeImmutable(Handle<MutableBigInt> result) {
   MutableBigInt::Canonicalize(*result);
   return Handle<BigInt>::cast(result);
@@ -412,7 +418,7 @@ void MutableBigInt::Canonicalize(MutableBigInt result) {
       // of the object changed significantly.
       heap->CreateFillerObjectAt(new_end, size_delta, ClearRecordedSlots::kNo);
     }
-    result.synchronized_set_length(new_length);
+    result.set_length(new_length, kReleaseStore);
 
     // Canonicalize -0n.
     if (new_length == 0) {
@@ -424,8 +430,8 @@ void MutableBigInt::Canonicalize(MutableBigInt result) {
                  result.digit(result.length() - 1) != 0);  // MSD is non-zero.
 }
 
-template <typename LocalIsolate>
-Handle<BigInt> BigInt::Zero(LocalIsolate* isolate, AllocationType allocation) {
+template <typename IsolateT>
+Handle<BigInt> BigInt::Zero(IsolateT* isolate, AllocationType allocation) {
   return MutableBigInt::Zero(isolate, allocation);
 }
 template Handle<BigInt> BigInt::Zero(Isolate* isolate,
@@ -531,29 +537,18 @@ MaybeHandle<BigInt> BigInt::Multiply(Isolate* isolate, Handle<BigInt> x,
                                      Handle<BigInt> y) {
   if (x->is_zero()) return x;
   if (y->is_zero()) return y;
-  int result_length = x->length() + y->length();
+  int result_length = bigint::MultiplyResultLength(GetDigits(x), GetDigits(y));
   Handle<MutableBigInt> result;
   if (!MutableBigInt::New(isolate, result_length).ToHandle(&result)) {
     return MaybeHandle<BigInt>();
   }
-  result->InitializeDigits(result_length);
-  uintptr_t work_estimate = 0;
-  for (int i = 0; i < x->length(); i++) {
-    MutableBigInt::MultiplyAccumulate(y, x->digit(i), result, i);
-
-    // Multiplication can take a long time. Check for interrupt requests
-    // every now and then (roughly every 10-20 of milliseconds -- rarely
-    // enough not to create noticeable overhead, frequently enough not to
-    // appear frozen).
-    work_estimate += y->length();
-    if (work_estimate > 5000000) {
-      work_estimate = 0;
-      StackLimitCheck interrupt_check(isolate);
-      if (interrupt_check.InterruptRequested() &&
-          isolate->stack_guard()->HandleInterrupts().IsException(isolate)) {
-        return MaybeHandle<BigInt>();
-      }
-    }
+  DisallowGarbageCollection no_gc;
+  bigint::Status status = isolate->bigint_processor()->Multiply(
+      GetRWDigits(result), GetDigits(x), GetDigits(y));
+  if (status == bigint::Status::kInterrupted) {
+    AllowGarbageCollection terminating_anyway;
+    isolate->TerminateExecution();
+    return {};
   }
   result->set_sign(x->sign() != y->sign());
   return MutableBigInt::MakeImmutable(result);
@@ -1449,46 +1444,6 @@ Handle<MutableBigInt> MutableBigInt::AbsoluteXor(Isolate* isolate,
                            [](digit_t a, digit_t b) { return a ^ b; });
 }
 
-// Multiplies {multiplicand} with {multiplier} and adds the result to
-// {accumulator}, starting at {accumulator_index} for the least-significant
-// digit.
-// Callers must ensure that {accumulator} is big enough to hold the result.
-void MutableBigInt::MultiplyAccumulate(Handle<BigIntBase> multiplicand,
-                                       digit_t multiplier,
-                                       Handle<MutableBigInt> accumulator,
-                                       int accumulator_index) {
-  // This is a minimum requirement; the DCHECK in the second loop below
-  // will enforce more as needed.
-  DCHECK(accumulator->length() > multiplicand->length() + accumulator_index);
-  if (multiplier == 0L) return;
-  digit_t carry = 0;
-  digit_t high = 0;
-  for (int i = 0; i < multiplicand->length(); i++, accumulator_index++) {
-    digit_t acc = accumulator->digit(accumulator_index);
-    digit_t new_carry = 0;
-    // Add last round's carryovers.
-    acc = digit_add(acc, high, &new_carry);
-    acc = digit_add(acc, carry, &new_carry);
-    // Compute this round's multiplication.
-    digit_t m_digit = multiplicand->digit(i);
-    digit_t low = digit_mul(multiplier, m_digit, &high);
-    acc = digit_add(acc, low, &new_carry);
-    // Store result and prepare for next round.
-    accumulator->set_digit(accumulator_index, acc);
-    carry = new_carry;
-  }
-  for (; carry != 0 || high != 0; accumulator_index++) {
-    DCHECK(accumulator_index < accumulator->length());
-    digit_t acc = accumulator->digit(accumulator_index);
-    digit_t new_carry = 0;
-    acc = digit_add(acc, high, &new_carry);
-    high = 0;
-    acc = digit_add(acc, carry, &new_carry);
-    accumulator->set_digit(accumulator_index, acc);
-    carry = new_carry;
-  }
-}
-
 // Multiplies {source} with {factor} and adds {summand} to the result.
 // {result} and {source} may be the same BigInt for inplace modification.
 void MutableBigInt::InternalMultiplyAdd(BigIntBase source, digit_t factor,
@@ -1928,9 +1883,9 @@ constexpr uint8_t kMaxBitsPerChar[] = {
 static const int kBitsPerCharTableShift = 5;
 static const size_t kBitsPerCharTableMultiplier = 1u << kBitsPerCharTableShift;
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 MaybeHandle<FreshlyAllocatedBigInt> BigInt::AllocateFor(
-    LocalIsolate* isolate, int radix, int charcount, ShouldThrow should_throw,
+    IsolateT* isolate, int radix, int charcount, ShouldThrow should_throw,
     AllocationType allocation) {
   DCHECK(2 <= radix && radix <= 36);
   DCHECK_GE(charcount, 0);
@@ -1966,7 +1921,7 @@ template MaybeHandle<FreshlyAllocatedBigInt> BigInt::AllocateFor(
     LocalIsolate* isolate, int radix, int charcount, ShouldThrow should_throw,
     AllocationType allocation);
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<BigInt> BigInt::Finalize(Handle<FreshlyAllocatedBigInt> x, bool sign) {
   Handle<MutableBigInt> bigint = Handle<MutableBigInt>::cast(x);
   bigint->set_sign(sign);
@@ -2249,7 +2204,7 @@ MaybeHandle<String> MutableBigInt::ToStringGeneric(Isolate* isolate,
   if (sign) chars[pos++] = '-';
   // Trim any over-allocation (which can happen due to conservative estimates).
   if (pos < static_cast<int>(chars_required)) {
-    result->synchronized_set_length(pos);
+    result->set_length(pos, kReleaseStore);
     int string_size =
         SeqOneByteString::SizeFor(static_cast<int>(chars_required));
     int needed_size = SeqOneByteString::SizeFor(pos);
diff --git a/chromium/v8/src/objects/bigint.h b/chromium/v8/src/objects/bigint.h
index a7494a54c5a..19dfca348a8 100644
--- a/chromium/v8/src/objects/bigint.h
+++ b/chromium/v8/src/objects/bigint.h
@@ -38,7 +38,7 @@ class BigIntBase : public PrimitiveHeapObject {
   }
 
   // For use by the GC.
-  inline int synchronized_length() const {
+  inline int length(AcquireLoadTag) const {
     int32_t bitfield = ACQUIRE_READ_INT32_FIELD(*this, kBitfieldOffset);
     return LengthBits::decode(static_cast<uint32_t>(bitfield));
   }
@@ -242,22 +242,22 @@ class BigInt : public BigIntBase {
   class BodyDescriptor;
 
  private:
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   friend class StringToBigIntHelper;
   friend class ValueDeserializer;
   friend class ValueSerializer;
 
   // Special functions for StringToBigIntHelper:
-  template <typename LocalIsolate>
-  static Handle<BigInt> Zero(LocalIsolate* isolate, AllocationType allocation =
-                                                        AllocationType::kYoung);
-  template <typename LocalIsolate>
+  template <typename IsolateT>
+  static Handle<BigInt> Zero(
+      IsolateT* isolate, AllocationType allocation = AllocationType::kYoung);
+  template <typename IsolateT>
   static MaybeHandle<FreshlyAllocatedBigInt> AllocateFor(
-      LocalIsolate* isolate, int radix, int charcount, ShouldThrow should_throw,
+      IsolateT* isolate, int radix, int charcount, ShouldThrow should_throw,
       AllocationType allocation);
   static void InplaceMultiplyAdd(FreshlyAllocatedBigInt x, uintptr_t factor,
                                  uintptr_t summand);
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   static Handle<BigInt> Finalize(Handle<FreshlyAllocatedBigInt> x, bool sign);
 
   // Special functions for ValueSerializer/ValueDeserializer:
diff --git a/chromium/v8/src/objects/code-inl.h b/chromium/v8/src/objects/code-inl.h
index 6fd3355a42f..f53c585538d 100644
--- a/chromium/v8/src/objects/code-inl.h
+++ b/chromium/v8/src/objects/code-inl.h
@@ -450,8 +450,8 @@ inline bool Code::is_interpreter_trampoline_builtin() const {
   const int index = builtin_index();
   return index != Builtins::kNoBuiltinId &&
          (index == Builtins::kInterpreterEntryTrampoline ||
-          index == Builtins::kInterpreterEnterBytecodeAdvance ||
-          index == Builtins::kInterpreterEnterBytecodeDispatch);
+          index == Builtins::kInterpreterEnterAtBytecode ||
+          index == Builtins::kInterpreterEnterAtNextBytecode);
 }
 
 inline bool Code::is_baseline_trampoline_builtin() const {
@@ -715,7 +715,7 @@ bool Code::IsWeakObject(HeapObject object) {
 }
 
 bool Code::IsWeakObjectInOptimizedCode(HeapObject object) {
-  Map map = object.synchronized_map();
+  Map map = object.map(kAcquireLoad);
   InstanceType instance_type = map.instance_type();
   if (InstanceTypeChecker::IsMap(instance_type)) {
     return Map::cast(object).CanTransition();
diff --git a/chromium/v8/src/objects/code-kind.cc b/chromium/v8/src/objects/code-kind.cc
index 8d480c86db9..5c4ab5d2991 100644
--- a/chromium/v8/src/objects/code-kind.cc
+++ b/chromium/v8/src/objects/code-kind.cc
@@ -24,8 +24,6 @@ const char* CodeKindToMarker(CodeKind kind) {
       return "~";
     case CodeKind::BASELINE:
       return "^";
-    case CodeKind::NATIVE_CONTEXT_INDEPENDENT:
-      return "-";
     case CodeKind::TURBOPROP:
       return "+";
     case CodeKind::TURBOFAN:
diff --git a/chromium/v8/src/objects/code-kind.h b/chromium/v8/src/objects/code-kind.h
index 12f65ba18aa..888e04c42b5 100644
--- a/chromium/v8/src/objects/code-kind.h
+++ b/chromium/v8/src/objects/code-kind.h
@@ -28,7 +28,6 @@ namespace internal {
   V(C_WASM_ENTRY)               \
   V(INTERPRETED_FUNCTION)       \
   V(BASELINE)                   \
-  V(NATIVE_CONTEXT_INDEPENDENT) \
   V(TURBOPROP)                  \
   V(TURBOFAN)
 
@@ -38,14 +37,10 @@ enum class CodeKind {
 #undef DEFINE_CODE_KIND_ENUM
 };
 STATIC_ASSERT(CodeKind::INTERPRETED_FUNCTION < CodeKind::TURBOPROP &&
-              CodeKind::INTERPRETED_FUNCTION <
-                  CodeKind::NATIVE_CONTEXT_INDEPENDENT &&
               CodeKind::INTERPRETED_FUNCTION < CodeKind::BASELINE);
-STATIC_ASSERT(CodeKind::BASELINE < CodeKind::TURBOPROP &&
-              CodeKind::BASELINE < CodeKind::NATIVE_CONTEXT_INDEPENDENT);
+STATIC_ASSERT(CodeKind::BASELINE < CodeKind::TURBOPROP);
 STATIC_ASSERT(CodeKind::BASELINE < CodeKind::TURBOFAN &&
-              CodeKind::TURBOPROP < CodeKind::TURBOFAN &&
-              CodeKind::NATIVE_CONTEXT_INDEPENDENT < CodeKind::TURBOFAN);
+              CodeKind::TURBOPROP < CodeKind::TURBOFAN);
 
 #define V(...) +1
 static constexpr int kCodeKindCount = CODE_KIND_LIST(V);
@@ -70,18 +65,10 @@ inline constexpr bool CodeKindIsUnoptimizedJSFunction(CodeKind kind) {
                          CodeKind::BASELINE);
 }
 
-inline constexpr bool CodeKindIsNativeContextIndependentJSFunction(
-    CodeKind kind) {
-  return kind == CodeKind::NATIVE_CONTEXT_INDEPENDENT;
-}
-
 inline constexpr bool CodeKindIsOptimizedJSFunction(CodeKind kind) {
-  STATIC_ASSERT(static_cast<int>(CodeKind::NATIVE_CONTEXT_INDEPENDENT) + 1 ==
-                static_cast<int>(CodeKind::TURBOPROP));
   STATIC_ASSERT(static_cast<int>(CodeKind::TURBOPROP) + 1 ==
                 static_cast<int>(CodeKind::TURBOFAN));
-  return base::IsInRange(kind, CodeKind::NATIVE_CONTEXT_INDEPENDENT,
-                         CodeKind::TURBOFAN);
+  return base::IsInRange(kind, CodeKind::TURBOPROP, CodeKind::TURBOFAN);
 }
 
 inline constexpr bool CodeKindIsJSFunction(CodeKind kind) {
@@ -94,9 +81,6 @@ inline constexpr bool CodeKindIsBuiltinOrJSFunction(CodeKind kind) {
 }
 
 inline constexpr bool CodeKindCanDeoptimize(CodeKind kind) {
-  // Even though NCI code does not deopt by itself at the time of writing,
-  // tests may trigger deopts manually and thus we cannot make a narrower
-  // distinction here.
   return CodeKindIsOptimizedJSFunction(kind);
 }
 
@@ -104,9 +88,8 @@ inline constexpr bool CodeKindCanOSR(CodeKind kind) {
   return kind == CodeKind::TURBOFAN || kind == CodeKind::TURBOPROP;
 }
 
-inline constexpr bool CodeKindIsOptimizedAndCanTierUp(CodeKind kind) {
-  return kind == CodeKind::NATIVE_CONTEXT_INDEPENDENT ||
-         (!FLAG_turboprop_as_toptier && kind == CodeKind::TURBOPROP);
+inline bool CodeKindIsOptimizedAndCanTierUp(CodeKind kind) {
+  return !FLAG_turboprop_as_toptier && kind == CodeKind::TURBOPROP;
 }
 
 inline constexpr bool CodeKindCanTierUp(CodeKind kind) {
@@ -116,8 +99,7 @@ inline constexpr bool CodeKindCanTierUp(CodeKind kind) {
 
 // The optimization marker field on the feedback vector has a dual purpose of
 // controlling the tier-up workflow, and caching the produced code object for
-// access from multiple closures. The marker is not used for all code kinds
-// though, in particular it is not used when generating NCI code.
+// access from multiple closures.
 inline constexpr bool CodeKindIsStoredInOptimizedCodeCache(CodeKind kind) {
   return kind == CodeKind::TURBOFAN || kind == CodeKind::TURBOPROP;
 }
@@ -128,9 +110,6 @@ inline OptimizationTier GetTierForCodeKind(CodeKind kind) {
     return FLAG_turboprop_as_toptier ? OptimizationTier::kTopTier
                                      : OptimizationTier::kMidTier;
   }
-  if (kind == CodeKind::NATIVE_CONTEXT_INDEPENDENT) {
-    return OptimizationTier::kTopTier;
-  }
   return OptimizationTier::kNone;
 }
 
@@ -169,11 +148,9 @@ DEFINE_OPERATORS_FOR_FLAGS(CodeKinds)
 
 static constexpr CodeKinds kJSFunctionCodeKindsMask{
     CodeKindFlag::INTERPRETED_FUNCTION | CodeKindFlag::TURBOFAN |
-    CodeKindFlag::NATIVE_CONTEXT_INDEPENDENT | CodeKindFlag::TURBOPROP |
-    CodeKindFlag::BASELINE};
+    CodeKindFlag::TURBOPROP | CodeKindFlag::BASELINE};
 static constexpr CodeKinds kOptimizedJSFunctionCodeKindsMask{
-    CodeKindFlag::TURBOFAN | CodeKindFlag::NATIVE_CONTEXT_INDEPENDENT |
-    CodeKindFlag::TURBOPROP};
+    CodeKindFlag::TURBOFAN | CodeKindFlag::TURBOPROP};
 
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/objects/code.cc b/chromium/v8/src/objects/code.cc
index 7268f001ce9..5b4ad4406d0 100644
--- a/chromium/v8/src/objects/code.cc
+++ b/chromium/v8/src/objects/code.cc
@@ -145,22 +145,42 @@ int Code::OffHeapInstructionSize() const {
   return d.InstructionSizeOfBuiltin(builtin_index());
 }
 
+namespace {
+
+// Helper function for getting an EmbeddedData that can handle un-embedded
+// builtins when short builtin calls are enabled.
+inline EmbeddedData EmbeddedDataWithMaybeRemappedEmbeddedBuiltins(Code code) {
+#if defined(V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE)
+  // GetIsolateFromWritableObject(*this) works for both read-only and writable
+  // objects when pointer compression is enabled with a per-Isolate cage.
+  return EmbeddedData::FromBlob(GetIsolateFromWritableObject(code));
+#elif defined(V8_COMPRESS_POINTERS_IN_SHARED_CAGE)
+  // When pointer compression is enabled with a shared cage, there is also a
+  // shared CodeRange. When short builtin calls are enabled, there is a single
+  // copy of the re-embedded builtins in the shared CodeRange, so use that if
+  // it's present.
+  if (FLAG_jitless) return EmbeddedData::FromBlob();
+  CodeRange* code_range = CodeRange::GetProcessWideCodeRange().get();
+  return (code_range && code_range->embedded_blob_code_copy() != nullptr)
+             ? EmbeddedData::FromBlob(code_range)
+             : EmbeddedData::FromBlob();
+#else
+  // Otherwise there is a single copy of the blob across all Isolates, use the
+  // global atomic variables.
+  return EmbeddedData::FromBlob();
+#endif
+}
+
+}  // namespace
+
 Address Code::OffHeapInstructionStart() const {
   DCHECK(is_off_heap_trampoline());
   if (Isolate::CurrentEmbeddedBlobCode() == nullptr) {
     return raw_instruction_size();
   }
-  // TODO(11527): pass Isolate as an argument.
-  // GetIsolateFromWritableObject(*this) works for both read-only and writable
-  // objects here because short builtin calls feature requires pointer
-  // compression.
-  // We don't have to check the Isolate::is_short_builtin_calls_enabled() value
-  // because if the short builtin calls wasn't actually enabled because of not
-  // enough memory, the FromBlob(isolate) would still be the correct one to use.
-  EmbeddedData d =
-      FLAG_short_builtin_calls
-          ? EmbeddedData::FromBlob(GetIsolateFromWritableObject(*this))
-          : EmbeddedData::FromBlob();
+
+  // TODO(11527): pass Isolate as an argument for getting the EmbeddedData.
+  EmbeddedData d = EmbeddedDataWithMaybeRemappedEmbeddedBuiltins(*this);
   return d.InstructionStartOfBuiltin(builtin_index());
 }
 
@@ -169,17 +189,9 @@ Address Code::OffHeapInstructionEnd() const {
   if (Isolate::CurrentEmbeddedBlobCode() == nullptr) {
     return raw_instruction_size();
   }
-  // TODO(11527): pass Isolate as an argument.
-  // GetIsolateFromWritableObject(*this) works for both read-only and writable
-  // objects here because short builtin calls feature requires pointer
-  // compression.
-  // We don't have to check the Isolate::is_short_builtin_calls_enabled() value
-  // because if the short builtin calls wasn't actually enabled because of not
-  // enough memory, the FromBlob(isolate) would still be the correct one to use.
-  EmbeddedData d =
-      FLAG_short_builtin_calls
-          ? EmbeddedData::FromBlob(GetIsolateFromWritableObject(*this))
-          : EmbeddedData::FromBlob();
+
+  // TODO(11527): pass Isolate as an argument for getting the EmbeddedData.
+  EmbeddedData d = EmbeddedDataWithMaybeRemappedEmbeddedBuiltins(*this);
   return d.InstructionStartOfBuiltin(builtin_index()) +
          d.InstructionSizeOfBuiltin(builtin_index());
 }
@@ -299,11 +311,12 @@ bool Code::IsIsolateIndependent(Isolate* isolate) {
                  RelocInfo::ModeMask(RelocInfo::WASM_STUB_CALL)));
 
 #if defined(V8_TARGET_ARCH_PPC) || defined(V8_TARGET_ARCH_PPC64) || \
-    defined(V8_TARGET_ARCH_MIPS64) || defined(V8_TARGET_ARCH_RISCV64)
+    defined(V8_TARGET_ARCH_MIPS64)
   return RelocIterator(*this, kModeMask).done();
 #elif defined(V8_TARGET_ARCH_X64) || defined(V8_TARGET_ARCH_ARM64) || \
     defined(V8_TARGET_ARCH_ARM) || defined(V8_TARGET_ARCH_MIPS) ||    \
-    defined(V8_TARGET_ARCH_S390) || defined(V8_TARGET_ARCH_IA32)
+    defined(V8_TARGET_ARCH_S390) || defined(V8_TARGET_ARCH_IA32) ||   \
+    defined(V8_TARGET_ARCH_RISCV64)
   for (RelocIterator it(*this, kModeMask); !it.done(); it.next()) {
     // On these platforms we emit relative builtin-to-builtin
     // jumps for isolate independent builtins in the snapshot. They are later
@@ -325,67 +338,6 @@ bool Code::IsIsolateIndependent(Isolate* isolate) {
   return true;
 }
 
-// Multiple native contexts live on the same heap, and V8 currently
-// draws no clear distinction between native-context-dependent and
-// independent objects. A good guideline is "objects embedded into
-// bytecode are nc-independent", since bytecode is shared between
-// native contexts. Among others, this is the case for ScopeInfo,
-// SharedFunctionInfo, String, etc.
-bool Code::IsNativeContextIndependent(Isolate* isolate) {
-  static constexpr int kModeMask =
-      RelocInfo::AllRealModesMask() &
-      ~RelocInfo::ModeMask(RelocInfo::CONST_POOL) &
-      ~RelocInfo::ModeMask(RelocInfo::EXTERNAL_REFERENCE) &
-      ~RelocInfo::ModeMask(RelocInfo::INTERNAL_REFERENCE) &
-      ~RelocInfo::ModeMask(RelocInfo::INTERNAL_REFERENCE_ENCODED) &
-      ~RelocInfo::ModeMask(RelocInfo::OFF_HEAP_TARGET) &
-      ~RelocInfo::ModeMask(RelocInfo::RUNTIME_ENTRY) &
-      ~RelocInfo::ModeMask(RelocInfo::VENEER_POOL);
-  STATIC_ASSERT(kModeMask ==
-                (RelocInfo::ModeMask(RelocInfo::CODE_TARGET) |
-                 RelocInfo::ModeMask(RelocInfo::RELATIVE_CODE_TARGET) |
-                 RelocInfo::ModeMask(RelocInfo::COMPRESSED_EMBEDDED_OBJECT) |
-                 RelocInfo::ModeMask(RelocInfo::FULL_EMBEDDED_OBJECT) |
-                 RelocInfo::ModeMask(RelocInfo::DATA_EMBEDDED_OBJECT) |
-                 RelocInfo::ModeMask(RelocInfo::WASM_CALL) |
-                 RelocInfo::ModeMask(RelocInfo::WASM_STUB_CALL)));
-
-  bool is_independent = true;
-  for (RelocIterator it(*this, kModeMask); !it.done(); it.next()) {
-    if (RelocInfo::IsEmbeddedObjectMode(it.rinfo()->rmode())) {
-      HeapObject o = it.rinfo()->target_object();
-      // TODO(jgruber,v8:8888): Extend this with further NCI objects,
-      // and define a more systematic
-      // IsNativeContextIndependent<T>() predicate.
-      if (o.IsString()) continue;
-      if (o.IsScopeInfo()) continue;
-      if (o.IsHeapNumber()) continue;
-      if (o.IsBigInt()) continue;
-      if (o.IsSharedFunctionInfo()) continue;
-      if (o.IsArrayBoilerplateDescription()) continue;
-      if (o.IsObjectBoilerplateDescription()) continue;
-      if (o.IsTemplateObjectDescription()) continue;
-      if (o.IsFixedArray()) {
-        // Some uses of FixedArray are valid.
-        // 1. Passed as arg to %DeclareGlobals, contains only strings
-        //    and SFIs.
-        // 2. Passed as arg to %DefineClass. No well defined contents.
-        // .. ?
-        // TODO(jgruber): Consider assigning dedicated instance
-        //    types instead of assuming fixed arrays are okay.
-        continue;
-      }
-      // Other objects are expected to be context-dependent.
-      PrintF("Found native-context-dependent object:\n");
-      o.Print();
-      o.map().Print();
-    }
-    is_independent = false;
-  }
-
-  return is_independent;
-}
-
 bool Code::Inlines(SharedFunctionInfo sfi) {
   // We can only check for inlining for optimized code.
   DCHECK(is_optimized_code());
@@ -474,7 +426,7 @@ void print_pc(std::ostream& os, int pc) {
 }
 }  // anonymous namespace
 
-void DeoptimizationData::DeoptimizationDataPrint(std::ostream& os) {  // NOLINT
+void DeoptimizationData::DeoptimizationDataPrint(std::ostream& os) {
   if (length() == 0) {
     os << "Deoptimization Input Data invalidated by lazy deoptimization\n";
     return;
diff --git a/chromium/v8/src/objects/code.h b/chromium/v8/src/objects/code.h
index d431701936f..fbd52505ee2 100644
--- a/chromium/v8/src/objects/code.h
+++ b/chromium/v8/src/objects/code.h
@@ -447,7 +447,6 @@ class Code : public HeapObject {
   inline HandlerTable::CatchPrediction GetBuiltinCatchPrediction();
 
   bool IsIsolateIndependent(Isolate* isolate);
-  bool IsNativeContextIndependent(Isolate* isolate);
 
   inline bool CanContainWeakObjects();
 
@@ -982,7 +981,7 @@ class DeoptimizationData : public FixedArray {
   DECL_CAST(DeoptimizationData)
 
 #ifdef ENABLE_DISASSEMBLER
-  void DeoptimizationDataPrint(std::ostream& os);  // NOLINT
+  void DeoptimizationDataPrint(std::ostream& os);
 #endif
 
  private:
diff --git a/chromium/v8/src/objects/compilation-cache-table.cc b/chromium/v8/src/objects/compilation-cache-table.cc
index 9ef14689753..b9345541167 100644
--- a/chromium/v8/src/objects/compilation-cache-table.cc
+++ b/chromium/v8/src/objects/compilation-cache-table.cc
@@ -295,16 +295,6 @@ Handle<Object> CompilationCacheTable::LookupRegExp(Handle<String> src,
   return Handle<Object>(get(EntryToIndex(entry) + 1), isolate);
 }
 
-MaybeHandle<Code> CompilationCacheTable::LookupCode(
-    Handle<SharedFunctionInfo> key) {
-  Isolate* isolate = GetIsolate();
-  DisallowGarbageCollection no_gc;
-  CodeKey k(key);
-  InternalIndex entry = FindEntry(isolate, &k);
-  if (entry.is_not_found()) return {};
-  return Handle<Code>(Code::cast(get(EntryToIndex(entry) + 1)), isolate);
-}
-
 Handle<CompilationCacheTable> CompilationCacheTable::PutScript(
     Handle<CompilationCacheTable> cache, Handle<String> src,
     LanguageMode language_mode, Handle<SharedFunctionInfo> value,
@@ -373,30 +363,6 @@ Handle<CompilationCacheTable> CompilationCacheTable::PutRegExp(
   return cache;
 }
 
-Handle<CompilationCacheTable> CompilationCacheTable::PutCode(
-    Isolate* isolate, Handle<CompilationCacheTable> cache,
-    Handle<SharedFunctionInfo> key, Handle<Code> value) {
-  CodeKey k(key);
-
-  {
-    InternalIndex entry = cache->FindEntry(isolate, &k);
-    if (entry.is_found()) {
-      // Update.
-      cache->set(EntryToIndex(entry), *key);
-      cache->set(EntryToIndex(entry) + 1, *value);
-      return cache;
-    }
-  }
-
-  // Insert.
-  cache = EnsureCapacity(isolate, cache);
-  InternalIndex entry = cache->FindInsertionEntry(isolate, k.Hash());
-  cache->set(EntryToIndex(entry), *key);
-  cache->set(EntryToIndex(entry) + 1, *value);
-  cache->ElementAdded();
-  return cache;
-}
-
 void CompilationCacheTable::Age(Isolate* isolate) {
   DisallowGarbageCollection no_gc;
   for (InternalIndex entry : IterateEntries()) {
diff --git a/chromium/v8/src/objects/compilation-cache-table.h b/chromium/v8/src/objects/compilation-cache-table.h
index 2fd548bfe57..e39e013c61c 100644
--- a/chromium/v8/src/objects/compilation-cache-table.h
+++ b/chromium/v8/src/objects/compilation-cache-table.h
@@ -123,13 +123,6 @@ class CompilationCacheTable
       Isolate* isolate, Handle<CompilationCacheTable> cache, Handle<String> src,
       JSRegExp::Flags flags, Handle<FixedArray> value);
 
-  // The Code cache shares native-context-independent (NCI) code between
-  // contexts.
-  MaybeHandle<Code> LookupCode(Handle<SharedFunctionInfo> key);
-  static Handle<CompilationCacheTable> PutCode(
-      Isolate* isolate, Handle<CompilationCacheTable> cache,
-      Handle<SharedFunctionInfo> key, Handle<Code> value);
-
   void Remove(Object value);
   void Age(Isolate* isolate);
 
diff --git a/chromium/v8/src/objects/compressed-slots-inl.h b/chromium/v8/src/objects/compressed-slots-inl.h
index 54c828d919a..b550c9f8515 100644
--- a/chromium/v8/src/objects/compressed-slots-inl.h
+++ b/chromium/v8/src/objects/compressed-slots-inl.h
@@ -28,6 +28,13 @@ bool CompressedObjectSlot::contains_value(Address raw_value) const {
          static_cast<uint32_t>(static_cast<Tagged_t>(raw_value));
 }
 
+bool CompressedObjectSlot::contains_map_value(Address raw_value) const {
+  // Simply forward to contains_value because map packing is not supported with
+  // pointer compression.
+  DCHECK(!V8_MAP_PACKING_BOOL);
+  return contains_value(raw_value);
+}
+
 Object CompressedObjectSlot::operator*() const {
   Tagged_t value = *location();
   return Object(DecompressTaggedAny(address(), value));
@@ -42,6 +49,20 @@ void CompressedObjectSlot::store(Object value) const {
   *location() = CompressTagged(value.ptr());
 }
 
+void CompressedObjectSlot::store_map(Map map) const {
+  // Simply forward to store because map packing is not supported with pointer
+  // compression.
+  DCHECK(!V8_MAP_PACKING_BOOL);
+  store(map);
+}
+
+Map CompressedObjectSlot::load_map() const {
+  // Simply forward to Relaxed_Load because map packing is not supported with
+  // pointer compression.
+  DCHECK(!V8_MAP_PACKING_BOOL);
+  return Map::unchecked_cast(Relaxed_Load());
+}
+
 Object CompressedObjectSlot::Acquire_Load() const {
   AtomicTagged_t value = AsAtomicTagged::Acquire_Load(location());
   return Object(DecompressTaggedAny(address(), value));
diff --git a/chromium/v8/src/objects/compressed-slots.h b/chromium/v8/src/objects/compressed-slots.h
index 7737e685fe0..f13fc15adcf 100644
--- a/chromium/v8/src/objects/compressed-slots.h
+++ b/chromium/v8/src/objects/compressed-slots.h
@@ -37,12 +37,16 @@ class CompressedObjectSlot : public SlotBase<CompressedObjectSlot, Tagged_t> {
   // Compares memory representation of a value stored in the slot with given
   // raw value without decompression.
   inline bool contains_value(Address raw_value) const;
+  inline bool contains_map_value(Address raw_value) const;
 
   // TODO(leszeks): Consider deprecating the operator* load, and always pass the
   // Isolate.
   inline Object operator*() const;
   inline Object load(PtrComprCageBase cage_base) const;
   inline void store(Object value) const;
+  inline void store_map(Map map) const;
+
+  inline Map load_map() const;
 
   inline Object Acquire_Load() const;
   inline Object Relaxed_Load() const;
diff --git a/chromium/v8/src/objects/contexts-inl.h b/chromium/v8/src/objects/contexts-inl.h
index 356df687ded..d744ffc6818 100644
--- a/chromium/v8/src/objects/contexts-inl.h
+++ b/chromium/v8/src/objects/contexts-inl.h
@@ -55,38 +55,54 @@ NEVER_READ_ONLY_SPACE_IMPL(Context)
 
 CAST_ACCESSOR(NativeContext)
 
-V8_INLINE Object Context::get(int index) const { return elements(index); }
-V8_INLINE Object Context::get(PtrComprCageBase cage_base, int index) const {
-  return elements(cage_base, index);
-}
-V8_INLINE void Context::set(int index, Object value) {
-  set_elements(index, value);
+Object Context::get(int index) const {
+  PtrComprCageBase cage_base = GetPtrComprCageBase(*this);
+  return get(cage_base, index);
 }
-V8_INLINE void Context::set(int index, Object value, WriteBarrierMode mode) {
-  set_elements(index, value, mode);
+
+Object Context::get(PtrComprCageBase cage_base, int index) const {
+  DCHECK_LT(static_cast<unsigned int>(index),
+            static_cast<unsigned int>(length()));
+  return TaggedField<Object>::Relaxed_Load(cage_base, *this,
+                                           OffsetOfElementAt(index));
 }
 
-void Context::set_scope_info(ScopeInfo scope_info, WriteBarrierMode mode) {
-  set(SCOPE_INFO_INDEX, scope_info, mode);
+void Context::set(int index, Object value, WriteBarrierMode mode) {
+  DCHECK_LT(static_cast<unsigned int>(index),
+            static_cast<unsigned int>(length()));
+  const int offset = OffsetOfElementAt(index);
+  RELAXED_WRITE_FIELD(*this, offset, value);
+  CONDITIONAL_WRITE_BARRIER(*this, offset, value, mode);
 }
 
-Object Context::synchronized_get(int index) const {
+Object Context::get(int index, AcquireLoadTag tag) const {
   PtrComprCageBase cage_base = GetPtrComprCageBase(*this);
-  return synchronized_get(cage_base, index);
+  return get(cage_base, index, tag);
 }
 
-Object Context::synchronized_get(PtrComprCageBase cage_base, int index) const {
+Object Context::get(PtrComprCageBase cage_base, int index,
+                    AcquireLoadTag) const {
   DCHECK_LT(static_cast<unsigned int>(index),
-            static_cast<unsigned int>(this->length()));
+            static_cast<unsigned int>(length()));
   return ACQUIRE_READ_FIELD(*this, OffsetOfElementAt(index));
 }
 
-void Context::synchronized_set(int index, Object value) {
+void Context::set(int index, Object value, WriteBarrierMode mode,
+                  ReleaseStoreTag) {
   DCHECK_LT(static_cast<unsigned int>(index),
-            static_cast<unsigned int>(this->length()));
+            static_cast<unsigned int>(length()));
   const int offset = OffsetOfElementAt(index);
   RELEASE_WRITE_FIELD(*this, offset, value);
-  WRITE_BARRIER(*this, offset, value);
+  CONDITIONAL_WRITE_BARRIER(*this, offset, value, mode);
+}
+
+void NativeContext::set(int index, Object value, WriteBarrierMode mode,
+                        ReleaseStoreTag tag) {
+  Context::set(index, value, mode, tag);
+}
+
+void Context::set_scope_info(ScopeInfo scope_info, WriteBarrierMode mode) {
+  set(SCOPE_INFO_INDEX, scope_info, mode);
 }
 
 Object Context::unchecked_previous() { return get(PREVIOUS_INDEX); }
@@ -161,18 +177,22 @@ bool Context::HasSameSecurityTokenAs(Context that) const {
          that.native_context().security_token();
 }
 
-#define NATIVE_CONTEXT_FIELD_ACCESSORS(index, type, name) \
-  void Context::set_##name(type value) {                  \
-    DCHECK(IsNativeContext());                            \
-    set(index, value);                                    \
-  }                                                       \
-  bool Context::is_##name(type value) const {             \
-    DCHECK(IsNativeContext());                            \
-    return type::cast(get(index)) == value;               \
-  }                                                       \
-  type Context::name() const {                            \
-    DCHECK(IsNativeContext());                            \
-    return type::cast(get(index));                        \
+#define NATIVE_CONTEXT_FIELD_ACCESSORS(index, type, name)   \
+  void Context::set_##name(type value) {                    \
+    DCHECK(IsNativeContext());                              \
+    set(index, value, UPDATE_WRITE_BARRIER, kReleaseStore); \
+  }                                                         \
+  bool Context::is_##name(type value) const {               \
+    DCHECK(IsNativeContext());                              \
+    return type::cast(get(index)) == value;                 \
+  }                                                         \
+  type Context::name() const {                              \
+    DCHECK(IsNativeContext());                              \
+    return type::cast(get(index));                          \
+  }                                                         \
+  type Context::name(AcquireLoadTag tag) const {            \
+    DCHECK(IsNativeContext());                              \
+    return type::cast(get(index, tag));                     \
   }
 NATIVE_CONTEXT_FIELDS(NATIVE_CONTEXT_FIELD_ACCESSORS)
 #undef NATIVE_CONTEXT_FIELD_ACCESSORS
@@ -242,8 +262,9 @@ Map Context::GetInitialJSArrayMap(ElementsKind kind) const {
 }
 
 DEF_GETTER(NativeContext, microtask_queue, MicrotaskQueue*) {
+  Isolate* isolate = GetIsolateForHeapSandbox(*this);
   return reinterpret_cast<MicrotaskQueue*>(ReadExternalPointerField(
-      kMicrotaskQueueOffset, cage_base, kNativeContextMicrotaskQueueTag));
+      kMicrotaskQueueOffset, isolate, kNativeContextMicrotaskQueueTag));
 }
 
 void NativeContext::AllocateExternalPointerEntries(Isolate* isolate) {
@@ -259,11 +280,13 @@ void NativeContext::set_microtask_queue(Isolate* isolate,
 
 void NativeContext::synchronized_set_script_context_table(
     ScriptContextTable script_context_table) {
-  synchronized_set(SCRIPT_CONTEXT_TABLE_INDEX, script_context_table);
+  set(SCRIPT_CONTEXT_TABLE_INDEX, script_context_table, UPDATE_WRITE_BARRIER,
+      kReleaseStore);
 }
 
 ScriptContextTable NativeContext::synchronized_script_context_table() const {
-  return ScriptContextTable::cast(synchronized_get(SCRIPT_CONTEXT_TABLE_INDEX));
+  return ScriptContextTable::cast(
+      get(SCRIPT_CONTEXT_TABLE_INDEX, kAcquireLoad));
 }
 
 OSROptimizedCodeCache NativeContext::GetOSROptimizedCodeCache() {
diff --git a/chromium/v8/src/objects/contexts.cc b/chromium/v8/src/objects/contexts.cc
index af73bf02568..eade27d934b 100644
--- a/chromium/v8/src/objects/contexts.cc
+++ b/chromium/v8/src/objects/contexts.cc
@@ -55,6 +55,7 @@ bool ScriptContextTable::Lookup(Isolate* isolate, ScriptContextTable table,
   for (int i = 0; i < table.synchronized_used(); i++) {
     Context context = table.get_context(i);
     DCHECK(context.IsScriptContext());
+    result->is_repl_mode = context.scope_info().IsReplModeScope();
     int slot_index = ScopeInfo::ContextSlotIndex(
         context.scope_info(), name, &result->mode, &result->init_flag,
         &result->maybe_assigned_flag, &is_static_flag);
@@ -415,11 +416,11 @@ void NativeContext::AddOptimizedCode(Code code) {
   DCHECK(CodeKindCanDeoptimize(code.kind()));
   DCHECK(code.next_code_link().IsUndefined());
   code.set_next_code_link(get(OPTIMIZED_CODE_LIST));
-  set(OPTIMIZED_CODE_LIST, code, UPDATE_WEAK_WRITE_BARRIER);
+  set(OPTIMIZED_CODE_LIST, code, UPDATE_WEAK_WRITE_BARRIER, kReleaseStore);
 }
 
 void NativeContext::SetOptimizedCodeListHead(Object head) {
-  set(OPTIMIZED_CODE_LIST, head, UPDATE_WEAK_WRITE_BARRIER);
+  set(OPTIMIZED_CODE_LIST, head, UPDATE_WEAK_WRITE_BARRIER, kReleaseStore);
 }
 
 Object NativeContext::OptimizedCodeListHead() {
@@ -427,7 +428,7 @@ Object NativeContext::OptimizedCodeListHead() {
 }
 
 void NativeContext::SetDeoptimizedCodeListHead(Object head) {
-  set(DEOPTIMIZED_CODE_LIST, head, UPDATE_WEAK_WRITE_BARRIER);
+  set(DEOPTIMIZED_CODE_LIST, head, UPDATE_WEAK_WRITE_BARRIER, kReleaseStore);
 }
 
 Object NativeContext::DeoptimizedCodeListHead() {
@@ -511,5 +512,53 @@ STATIC_ASSERT(NativeContext::kSize ==
               (Context::SizeFor(NativeContext::NATIVE_CONTEXT_SLOTS) +
                kSystemPointerSize));
 
+void NativeContext::RunPromiseHook(PromiseHookType type,
+                                   Handle<JSPromise> promise,
+                                   Handle<Object> parent) {
+  Isolate* isolate = promise->GetIsolate();
+  DCHECK(isolate->HasContextPromiseHooks());
+  int contextSlot;
+
+  switch (type) {
+    case PromiseHookType::kInit:
+      contextSlot = PROMISE_HOOK_INIT_FUNCTION_INDEX;
+      break;
+    case PromiseHookType::kResolve:
+      contextSlot = PROMISE_HOOK_RESOLVE_FUNCTION_INDEX;
+      break;
+    case PromiseHookType::kBefore:
+      contextSlot = PROMISE_HOOK_BEFORE_FUNCTION_INDEX;
+      break;
+    case PromiseHookType::kAfter:
+      contextSlot = PROMISE_HOOK_AFTER_FUNCTION_INDEX;
+      break;
+    default:
+      UNREACHABLE();
+  }
+
+  Handle<Object> hook(isolate->native_context()->get(contextSlot), isolate);
+  if (hook->IsUndefined()) return;
+
+  int argc = type == PromiseHookType::kInit ? 2 : 1;
+  Handle<Object> argv[2] = {
+    Handle<Object>::cast(promise),
+    parent
+  };
+
+  Handle<Object> receiver = isolate->global_proxy();
+
+  if (Execution::Call(isolate, hook, receiver, argc, argv).is_null()) {
+    DCHECK(isolate->has_pending_exception());
+    Handle<Object> exception(isolate->pending_exception(), isolate);
+
+    MessageLocation* no_location = nullptr;
+    Handle<JSMessageObject> message =
+        isolate->CreateMessageOrAbort(exception, no_location);
+    MessageHandler::ReportMessage(isolate, no_location, message);
+
+    isolate->clear_pending_exception();
+  }
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/objects/contexts.h b/chromium/v8/src/objects/contexts.h
index 79aed5d40ff..2c8988f13ec 100644
--- a/chromium/v8/src/objects/contexts.h
+++ b/chromium/v8/src/objects/contexts.h
@@ -50,7 +50,8 @@ enum ContextLookupFlags {
   V(MATH_POW_INDEX, JSFunction, math_pow)                         \
   V(PROMISE_INTERNAL_CONSTRUCTOR_INDEX, JSFunction,               \
     promise_internal_constructor)                                 \
-  V(PROMISE_THEN_INDEX, JSFunction, promise_then)
+  V(PROMISE_THEN_INDEX, JSFunction, promise_then)                 \
+  V(FUNCTION_PROTOTYPE_APPLY_INDEX, JSFunction, function_prototype_apply)
 
 #define NATIVE_CONTEXT_FIELDS(V)                                               \
   V(GLOBAL_PROXY_INDEX, JSGlobalProxy, global_proxy_object)                    \
@@ -111,6 +112,8 @@ enum ContextLookupFlags {
   V(GENERATOR_OBJECT_PROTOTYPE_MAP_INDEX, Map, generator_object_prototype_map) \
   V(ASYNC_GENERATOR_OBJECT_PROTOTYPE_MAP_INDEX, Map,                           \
     async_generator_object_prototype_map)                                      \
+  V(GROWABLE_SHARED_ARRAY_BUFFER_FUN_INDEX, JSFunction,                        \
+    growable_shared_array_buffer_fun)                                          \
   V(INITIAL_ARRAY_ITERATOR_MAP_INDEX, Map, initial_array_iterator_map)         \
   V(INITIAL_ARRAY_ITERATOR_PROTOTYPE_INDEX, JSObject,                          \
     initial_array_iterator_prototype)                                          \
@@ -198,12 +201,29 @@ enum ContextLookupFlags {
   V(NUMBER_FUNCTION_INDEX, JSFunction, number_function)                        \
   V(OBJECT_FUNCTION_INDEX, JSFunction, object_function)                        \
   V(OBJECT_FUNCTION_PROTOTYPE_MAP_INDEX, Map, object_function_prototype_map)   \
+  V(PROMISE_HOOK_INIT_FUNCTION_INDEX, Object, promise_hook_init_function)      \
+  V(PROMISE_HOOK_BEFORE_FUNCTION_INDEX, Object, promise_hook_before_function)  \
+  V(PROMISE_HOOK_AFTER_FUNCTION_INDEX, Object, promise_hook_after_function)    \
+  V(PROMISE_HOOK_RESOLVE_FUNCTION_INDEX, Object,                               \
+    promise_hook_resolve_function)                                             \
   V(PROXY_CALLABLE_MAP_INDEX, Map, proxy_callable_map)                         \
   V(PROXY_CONSTRUCTOR_MAP_INDEX, Map, proxy_constructor_map)                   \
   V(PROXY_FUNCTION_INDEX, JSFunction, proxy_function)                          \
   V(PROXY_MAP_INDEX, Map, proxy_map)                                           \
   V(PROXY_REVOCABLE_RESULT_MAP_INDEX, Map, proxy_revocable_result_map)         \
   V(PROMISE_PROTOTYPE_INDEX, JSObject, promise_prototype)                      \
+  V(RAB_GSAB_UINT8_ARRAY_MAP_INDEX, Map, rab_gsab_uint8_array_map)             \
+  V(RAB_GSAB_INT8_ARRAY_MAP_INDEX, Map, rab_gsab_int8_array_map)               \
+  V(RAB_GSAB_UINT16_ARRAY_MAP_INDEX, Map, rab_gsab_uint16_array_map)           \
+  V(RAB_GSAB_INT16_ARRAY_MAP_INDEX, Map, rab_gsab_int16_array_map)             \
+  V(RAB_GSAB_UINT32_ARRAY_MAP_INDEX, Map, rab_gsab_uint32_array_map)           \
+  V(RAB_GSAB_INT32_ARRAY_MAP_INDEX, Map, rab_gsab_int32_array_map)             \
+  V(RAB_GSAB_FLOAT32_ARRAY_MAP_INDEX, Map, rab_gsab_float32_array_map)         \
+  V(RAB_GSAB_FLOAT64_ARRAY_MAP_INDEX, Map, rab_gsab_float64_array_map)         \
+  V(RAB_GSAB_UINT8_CLAMPED_ARRAY_MAP_INDEX, Map,                               \
+    rab_gsab_uint8_clamped_array_map)                                          \
+  V(RAB_GSAB_BIGUINT64_ARRAY_MAP_INDEX, Map, rab_gsab_biguint64_array_map)     \
+  V(RAB_GSAB_BIGINT64_ARRAY_MAP_INDEX, Map, rab_gsab_bigint64_array_map)       \
   V(RECORDER_CONTEXT_ID, Object, recorder_context_id)                          \
   V(REGEXP_EXEC_FUNCTION_INDEX, JSFunction, regexp_exec_function)              \
   V(REGEXP_FUNCTION_INDEX, JSFunction, regexp_function)                        \
@@ -220,6 +240,7 @@ enum ContextLookupFlags {
   V(REGEXP_SPLIT_FUNCTION_INDEX, JSFunction, regexp_split_function)            \
   V(INITIAL_REGEXP_STRING_ITERATOR_PROTOTYPE_MAP_INDEX, Map,                   \
     initial_regexp_string_iterator_prototype_map)                              \
+  V(RESIZABLE_ARRAY_BUFFER_FUN_INDEX, JSFunction, resizable_array_buffer_fun)  \
   V(SCRIPT_CONTEXT_TABLE_INDEX, ScriptContextTable, script_context_table)      \
   V(SCRIPT_EXECUTION_CALLBACK_INDEX, Object, script_execution_callback)        \
   V(SECURITY_TOKEN_INDEX, Object, security_token)                              \
@@ -337,6 +358,9 @@ class ScriptContextTable : public FixedArray {
   struct LookupResult {
     int context_index;
     int slot_index;
+    // repl_mode flag is needed to disable inlining of 'const' variables in REPL
+    // mode.
+    bool is_repl_mode;
     VariableMode mode;
     InitializationFlag init_flag;
     MaybeAssignedFlag maybe_assigned_flag;
@@ -421,16 +445,18 @@ class Context : public TorqueGeneratedContext<Context, HeapObject> {
   NEVER_READ_ONLY_SPACE
 
   // Setter and getter for elements.
+  // Note the plain accessors use relaxed semantics.
+  // TODO(jgruber): Make that explicit through tags.
   V8_INLINE Object get(int index) const;
   V8_INLINE Object get(PtrComprCageBase cage_base, int index) const;
-  V8_INLINE void set(int index, Object value);
-  // Setter with explicit barrier mode.
-  V8_INLINE void set(int index, Object value, WriteBarrierMode mode);
-  // Setter and getter with synchronization semantics.
-  V8_INLINE Object synchronized_get(int index) const;
-  V8_INLINE Object synchronized_get(PtrComprCageBase cage_base,
-                                    int index) const;
-  V8_INLINE void synchronized_set(int index, Object value);
+  V8_INLINE void set(int index, Object value,
+                     WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
+  // Accessors with acquire-release semantics.
+  V8_INLINE Object get(int index, AcquireLoadTag) const;
+  V8_INLINE Object get(PtrComprCageBase cage_base, int index,
+                       AcquireLoadTag) const;
+  V8_INLINE void set(int index, Object value, WriteBarrierMode mode,
+                     ReleaseStoreTag);
 
   static const int kScopeInfoOffset = kElementsOffset;
   static const int kPreviousOffset = kScopeInfoOffset + kTaggedSize;
@@ -447,7 +473,7 @@ class Context : public TorqueGeneratedContext<Context, HeapObject> {
   V8_INLINE static constexpr int SizeFor(int length) {
     // TODO(v8:9287): This is a workaround for GCMole build failures.
     int result = kElementsOffset + length * kTaggedSize;
-    CONSTEXPR_DCHECK(TorqueGeneratedContext::SizeFor(length) == result);
+    DCHECK_EQ(TorqueGeneratedContext::SizeFor(length), result);
     return result;
   }
 
@@ -523,8 +549,6 @@ class Context : public TorqueGeneratedContext<Context, HeapObject> {
 
   inline Object unchecked_previous();
   inline Context previous();
-  inline void set_previous(Context context,
-                           WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
 
   inline Object next_context_link();
 
@@ -582,7 +606,8 @@ class Context : public TorqueGeneratedContext<Context, HeapObject> {
 #define NATIVE_CONTEXT_FIELD_ACCESSORS(index, type, name) \
   inline void set_##name(type value);                     \
   inline bool is_##name(type value) const;                \
-  inline type name() const;
+  inline type name() const;                               \
+  inline type name(AcquireLoadTag) const;
   NATIVE_CONTEXT_FIELDS(NATIVE_CONTEXT_FIELD_ACCESSORS)
 #undef NATIVE_CONTEXT_FIELD_ACCESSORS
 
@@ -638,6 +663,10 @@ class Context : public TorqueGeneratedContext<Context, HeapObject> {
   static bool IsBootstrappingOrValidParentContext(Object object, Context kid);
 #endif
 
+  friend class Factory;
+  inline void set_previous(Context context,
+                           WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
+
   TQ_OBJECT_CONSTRUCTORS(Context)
 };
 
@@ -648,6 +677,15 @@ class NativeContext : public Context {
 
   inline void AllocateExternalPointerEntries(Isolate* isolate);
 
+  // NativeContext fields are read concurrently from background threads; any
+  // concurrent writes of affected fields must have acquire-release semantics,
+  // thus we hide the non-atomic setter. Note this doesn't protect fully since
+  // one could still use Context::set and/or write directly using offsets (e.g.
+  // from CSA/Torque).
+  void set(int index, Object value, WriteBarrierMode mode) = delete;
+  V8_INLINE void set(int index, Object value, WriteBarrierMode mode,
+                     ReleaseStoreTag);
+
   // [microtask_queue]: pointer to the MicrotaskQueue object.
   DECL_GETTER(microtask_queue, MicrotaskQueue*)
   inline void set_microtask_queue(Isolate* isolate, MicrotaskQueue* queue);
@@ -696,6 +734,9 @@ class NativeContext : public Context {
   void IncrementErrorsThrown();
   int GetErrorsThrown();
 
+  void RunPromiseHook(PromiseHookType type, Handle<JSPromise> promise,
+                      Handle<Object> parent);
+
  private:
   STATIC_ASSERT(OffsetOfElementAt(EMBEDDER_DATA_INDEX) ==
                 Internals::kNativeContextEmbedderDataOffset);
diff --git a/chromium/v8/src/objects/contexts.tq b/chromium/v8/src/objects/contexts.tq
index 604852c24ea..83c43cc7f57 100644
--- a/chromium/v8/src/objects/contexts.tq
+++ b/chromium/v8/src/objects/contexts.tq
@@ -13,7 +13,7 @@ class Context extends HeapObject {
     return *ContextSlot(this, ContextSlot::SCOPE_INFO_INDEX);
   }
   const length: Smi;
-  @relaxedRead @relaxedWrite elements[length]: Object;
+  elements[length]: Object;
 }
 
 extern class AwaitContext extends Context generates 'TNode<Context>';
@@ -118,12 +118,42 @@ extern enum ContextSlot extends intptr constexpr 'Context::Field' {
   SLOPPY_ARGUMENTS_MAP_INDEX: Slot<NativeContext, Map>,
   FAST_ALIASED_ARGUMENTS_MAP_INDEX: Slot<NativeContext, Map>,
   FUNCTION_CONTEXT_MAP_INDEX: Slot<NativeContext, Map>,
+  FUNCTION_PROTOTYPE_APPLY_INDEX: Slot<NativeContext, JSFunction>,
+
+  UINT8_ARRAY_FUN_INDEX: Slot<NativeContext, JSFunction>,
+  INT8_ARRAY_FUN_INDEX: Slot<NativeContext, JSFunction>,
+  UINT16_ARRAY_FUN_INDEX: Slot<NativeContext, JSFunction>,
+  INT16_ARRAY_FUN_INDEX: Slot<NativeContext, JSFunction>,
+  UINT32_ARRAY_FUN_INDEX: Slot<NativeContext, JSFunction>,
+  INT32_ARRAY_FUN_INDEX: Slot<NativeContext, JSFunction>,
+  FLOAT32_ARRAY_FUN_INDEX: Slot<NativeContext, JSFunction>,
+  FLOAT64_ARRAY_FUN_INDEX: Slot<NativeContext, JSFunction>,
+  UINT8_CLAMPED_ARRAY_FUN_INDEX: Slot<NativeContext, JSFunction>,
+  BIGUINT64_ARRAY_FUN_INDEX: Slot<NativeContext, JSFunction>,
+  BIGINT64_ARRAY_FUN_INDEX: Slot<NativeContext, JSFunction>,
+
+  RAB_GSAB_UINT8_ARRAY_MAP_INDEX: Slot<NativeContext, Map>,
+  RAB_GSAB_INT8_ARRAY_MAP_INDEX: Slot<NativeContext, Map>,
+  RAB_GSAB_UINT16_ARRAY_MAP_INDEX: Slot<NativeContext, Map>,
+  RAB_GSAB_INT16_ARRAY_MAP_INDEX: Slot<NativeContext, Map>,
+  RAB_GSAB_UINT32_ARRAY_MAP_INDEX: Slot<NativeContext, Map>,
+  RAB_GSAB_INT32_ARRAY_MAP_INDEX: Slot<NativeContext, Map>,
+  RAB_GSAB_FLOAT32_ARRAY_MAP_INDEX: Slot<NativeContext, Map>,
+  RAB_GSAB_FLOAT64_ARRAY_MAP_INDEX: Slot<NativeContext, Map>,
+  RAB_GSAB_UINT8_CLAMPED_ARRAY_MAP_INDEX: Slot<NativeContext, Map>,
+  RAB_GSAB_BIGUINT64_ARRAY_MAP_INDEX: Slot<NativeContext, Map>,
+  RAB_GSAB_BIGINT64_ARRAY_MAP_INDEX: Slot<NativeContext, Map>,
 
   PROMISE_FUNCTION_INDEX: Slot<NativeContext, JSFunction>,
   PROMISE_THEN_INDEX: Slot<NativeContext, JSFunction>,
   PROMISE_PROTOTYPE_INDEX: Slot<NativeContext, JSObject>,
   STRICT_FUNCTION_WITHOUT_PROTOTYPE_MAP_INDEX: Slot<NativeContext, Map>,
 
+  PROMISE_HOOK_INIT_FUNCTION_INDEX: Slot<NativeContext, Undefined|Callable>,
+  PROMISE_HOOK_BEFORE_FUNCTION_INDEX: Slot<NativeContext, Undefined|Callable>,
+  PROMISE_HOOK_AFTER_FUNCTION_INDEX: Slot<NativeContext, Undefined|Callable>,
+  PROMISE_HOOK_RESOLVE_FUNCTION_INDEX: Slot<NativeContext, Undefined|Callable>,
+
   CONTINUATION_PRESERVED_EMBEDDER_DATA_INDEX: Slot<NativeContext, HeapObject>,
 
   BOUND_FUNCTION_WITH_CONSTRUCTOR_MAP_INDEX: Slot<NativeContext, Map>,
diff --git a/chromium/v8/src/objects/debug-objects-inl.h b/chromium/v8/src/objects/debug-objects-inl.h
index 8c8b013e232..e9e7c08f4cd 100644
--- a/chromium/v8/src/objects/debug-objects-inl.h
+++ b/chromium/v8/src/objects/debug-objects-inl.h
@@ -36,12 +36,6 @@ BIT_FIELD_ACCESSORS(DebugInfo, debugger_hints, computed_debug_is_blackboxed,
 BIT_FIELD_ACCESSORS(DebugInfo, debugger_hints, debugging_id,
                     DebugInfo::DebuggingIdBits)
 
-// TODO(nicohartmann@, v8:11122): Remove once Torque can generate them.
-RELEASE_ACQUIRE_ACCESSORS(DebugInfo, debug_bytecode_array, HeapObject,
-                          kDebugBytecodeArrayOffset)
-RELEASE_ACQUIRE_ACCESSORS(DebugInfo, original_bytecode_array, HeapObject,
-                          kOriginalBytecodeArrayOffset)
-
 bool DebugInfo::HasInstrumentedBytecodeArray() {
   return debug_bytecode_array(kAcquireLoad).IsBytecodeArray();
 }
diff --git a/chromium/v8/src/objects/debug-objects.cc b/chromium/v8/src/objects/debug-objects.cc
index ecb24632ef2..d3caa122332 100644
--- a/chromium/v8/src/objects/debug-objects.cc
+++ b/chromium/v8/src/objects/debug-objects.cc
@@ -14,18 +14,23 @@ namespace v8 {
 namespace internal {
 
 bool DebugInfo::IsEmpty() const {
-  return flags() == kNone && debugger_hints() == 0;
+  return flags(kRelaxedLoad) == kNone && debugger_hints() == 0;
 }
 
-bool DebugInfo::HasBreakInfo() const { return (flags() & kHasBreakInfo) != 0; }
+bool DebugInfo::HasBreakInfo() const {
+  return (flags(kRelaxedLoad) & kHasBreakInfo) != 0;
+}
 
 DebugInfo::ExecutionMode DebugInfo::DebugExecutionMode() const {
-  return (flags() & kDebugExecutionMode) != 0 ? kSideEffects : kBreakpoints;
+  return (flags(kRelaxedLoad) & kDebugExecutionMode) != 0 ? kSideEffects
+                                                          : kBreakpoints;
 }
 
 void DebugInfo::SetDebugExecutionMode(ExecutionMode value) {
-  set_flags(value == kSideEffects ? (flags() | kDebugExecutionMode)
-                                  : (flags() & ~kDebugExecutionMode));
+  set_flags(value == kSideEffects
+                ? (flags(kRelaxedLoad) | kDebugExecutionMode)
+                : (flags(kRelaxedLoad) & ~kDebugExecutionMode),
+            kRelaxedStore);
 }
 
 void DebugInfo::ClearBreakInfo(Isolate* isolate) {
@@ -45,27 +50,29 @@ void DebugInfo::ClearBreakInfo(Isolate* isolate) {
   }
   set_break_points(ReadOnlyRoots(isolate).empty_fixed_array());
 
-  int new_flags = flags();
+  int new_flags = flags(kRelaxedLoad);
   new_flags &= ~kHasBreakInfo & ~kPreparedForDebugExecution;
   new_flags &= ~kBreakAtEntry & ~kCanBreakAtEntry;
   new_flags &= ~kDebugExecutionMode;
-  set_flags(new_flags);
+  set_flags(new_flags, kRelaxedStore);
 }
 
 void DebugInfo::SetBreakAtEntry() {
   DCHECK(CanBreakAtEntry());
-  set_flags(flags() | kBreakAtEntry);
+  set_flags(flags(kRelaxedLoad) | kBreakAtEntry, kRelaxedStore);
 }
 
 void DebugInfo::ClearBreakAtEntry() {
   DCHECK(CanBreakAtEntry());
-  set_flags(flags() & ~kBreakAtEntry);
+  set_flags(flags(kRelaxedLoad) & ~kBreakAtEntry, kRelaxedStore);
 }
 
-bool DebugInfo::BreakAtEntry() const { return (flags() & kBreakAtEntry) != 0; }
+bool DebugInfo::BreakAtEntry() const {
+  return (flags(kRelaxedLoad) & kBreakAtEntry) != 0;
+}
 
 bool DebugInfo::CanBreakAtEntry() const {
-  return (flags() & kCanBreakAtEntry) != 0;
+  return (flags(kRelaxedLoad) & kCanBreakAtEntry) != 0;
 }
 
 // Check if there is a break point at this source position.
@@ -199,15 +206,15 @@ Handle<Object> DebugInfo::FindBreakPointInfo(Isolate* isolate,
 }
 
 bool DebugInfo::HasCoverageInfo() const {
-  return (flags() & kHasCoverageInfo) != 0;
+  return (flags(kRelaxedLoad) & kHasCoverageInfo) != 0;
 }
 
 void DebugInfo::ClearCoverageInfo(Isolate* isolate) {
   if (HasCoverageInfo()) {
     set_coverage_info(ReadOnlyRoots(isolate).undefined_value());
 
-    int new_flags = flags() & ~kHasCoverageInfo;
-    set_flags(new_flags);
+    int new_flags = flags(kRelaxedLoad) & ~kHasCoverageInfo;
+    set_flags(new_flags, kRelaxedStore);
   }
 }
 
diff --git a/chromium/v8/src/objects/debug-objects.h b/chromium/v8/src/objects/debug-objects.h
index e92a3026f88..77c9b80e659 100644
--- a/chromium/v8/src/objects/debug-objects.h
+++ b/chromium/v8/src/objects/debug-objects.h
@@ -37,7 +37,10 @@ class DebugInfo : public TorqueGeneratedDebugInfo<DebugInfo, Struct> {
   // --- Debug execution ---
   // -----------------------
 
-  enum ExecutionMode { kBreakpoints = 0, kSideEffects = kDebugExecutionMode };
+  enum ExecutionMode : uint8_t {
+    kBreakpoints = 0,
+    kSideEffects = kDebugExecutionMode
+  };
 
   // Returns current debug execution mode. Debug execution mode defines by
   // applied to bytecode patching. False for breakpoints, true for side effect
@@ -45,9 +48,6 @@ class DebugInfo : public TorqueGeneratedDebugInfo<DebugInfo, Struct> {
   ExecutionMode DebugExecutionMode() const;
   void SetDebugExecutionMode(ExecutionMode value);
 
-  DECL_RELEASE_ACQUIRE_ACCESSORS(debug_bytecode_array, HeapObject)
-  DECL_RELEASE_ACQUIRE_ACCESSORS(original_bytecode_array, HeapObject)
-
   // Specifies whether the associated function has an instrumented bytecode
   // array. If so, OriginalBytecodeArray returns the non-instrumented bytecode,
   // and DebugBytecodeArray returns the instrumented bytecode.
diff --git a/chromium/v8/src/objects/debug-objects.tq b/chromium/v8/src/objects/debug-objects.tq
index b8ca86781fe..1df2e7a484d 100644
--- a/chromium/v8/src/objects/debug-objects.tq
+++ b/chromium/v8/src/objects/debug-objects.tq
@@ -44,14 +44,18 @@ extern class DebugInfo extends Struct {
   script: Undefined|Script;
   // The original uninstrumented bytecode array for functions with break
   // points - the instrumented bytecode is held in the shared function info.
+  @cppAcquireLoad
+  @cppReleaseStore
   original_bytecode_array: Undefined|BytecodeArray;
   // The debug instrumented bytecode array for functions with break points
   // - also pointed to by the shared function info.
+  @cppAcquireLoad
+  @cppReleaseStore
   debug_bytecode_array: Undefined|BytecodeArray;
   // Fixed array holding status information for each active break point.
   break_points: FixedArray;
   // A bitfield that lists uses of the current instance.
-  flags: SmiTagged<DebugInfoFlags>;
+  @cppRelaxedLoad @cppRelaxedStore flags: SmiTagged<DebugInfoFlags>;
   coverage_info: CoverageInfo|Undefined;
 }
 
diff --git a/chromium/v8/src/objects/descriptor-array.h b/chromium/v8/src/objects/descriptor-array.h
index 327931a421e..1a9eb7fae1f 100644
--- a/chromium/v8/src/objects/descriptor-array.h
+++ b/chromium/v8/src/objects/descriptor-array.h
@@ -133,9 +133,9 @@ class DescriptorArray
 
   // Allocates a DescriptorArray, but returns the singleton
   // empty descriptor array object if number_of_descriptors is 0.
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   V8_EXPORT_PRIVATE static Handle<DescriptorArray> Allocate(
-      LocalIsolate* isolate, int nof_descriptors, int slack,
+      IsolateT* isolate, int nof_descriptors, int slack,
       AllocationType allocation = AllocationType::kYoung);
 
   void Initialize(EnumCache enum_cache, HeapObject undefined_value,
diff --git a/chromium/v8/src/objects/dictionary.h b/chromium/v8/src/objects/dictionary.h
index be255f8162d..a2db1b6289b 100644
--- a/chromium/v8/src/objects/dictionary.h
+++ b/chromium/v8/src/objects/dictionary.h
@@ -76,9 +76,9 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) Dictionary
   // Garbage collection support.
   inline ObjectSlot RawFieldOfValueAt(InternalIndex entry);
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   V8_WARN_UNUSED_RESULT static Handle<Derived> Add(
-      LocalIsolate* isolate, Handle<Derived> dictionary, Key key,
+      IsolateT* isolate, Handle<Derived> dictionary, Key key,
       Handle<Object> value, PropertyDetails details,
       InternalIndex* entry_out = nullptr);
 
@@ -142,9 +142,9 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) BaseNameDictionary
   inline int Hash() const;
 
   // Creates a new dictionary.
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   V8_WARN_UNUSED_RESULT static Handle<Derived> New(
-      LocalIsolate* isolate, int at_least_space_for,
+      IsolateT* isolate, int at_least_space_for,
       AllocationType allocation = AllocationType::kYoung,
       MinimumCapacity capacity_option = USE_DEFAULT_MINIMUM_CAPACITY);
 
@@ -159,9 +159,9 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) BaseNameDictionary
   static Handle<FixedArray> IterationIndices(Isolate* isolate,
                                              Handle<Derived> dictionary);
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   V8_WARN_UNUSED_RESULT static Handle<Derived> AddNoUpdateNextEnumerationIndex(
-      LocalIsolate* isolate, Handle<Derived> dictionary, Key key,
+      IsolateT* isolate, Handle<Derived> dictionary, Key key,
       Handle<Object> value, PropertyDetails details,
       InternalIndex* entry_out = nullptr);
 
diff --git a/chromium/v8/src/objects/elements-kind.cc b/chromium/v8/src/objects/elements-kind.cc
index 78670f25bd0..6ffa34b868f 100644
--- a/chromium/v8/src/objects/elements-kind.cc
+++ b/chromium/v8/src/objects/elements-kind.cc
@@ -17,19 +17,30 @@ int ElementsKindToShiftSize(ElementsKind elements_kind) {
     case UINT8_ELEMENTS:
     case INT8_ELEMENTS:
     case UINT8_CLAMPED_ELEMENTS:
+    case RAB_GSAB_UINT8_ELEMENTS:
+    case RAB_GSAB_INT8_ELEMENTS:
+    case RAB_GSAB_UINT8_CLAMPED_ELEMENTS:
       return 0;
     case UINT16_ELEMENTS:
     case INT16_ELEMENTS:
+    case RAB_GSAB_UINT16_ELEMENTS:
+    case RAB_GSAB_INT16_ELEMENTS:
       return 1;
     case UINT32_ELEMENTS:
     case INT32_ELEMENTS:
     case FLOAT32_ELEMENTS:
+    case RAB_GSAB_UINT32_ELEMENTS:
+    case RAB_GSAB_INT32_ELEMENTS:
+    case RAB_GSAB_FLOAT32_ELEMENTS:
       return 2;
     case PACKED_DOUBLE_ELEMENTS:
     case HOLEY_DOUBLE_ELEMENTS:
     case FLOAT64_ELEMENTS:
     case BIGINT64_ELEMENTS:
     case BIGUINT64_ELEMENTS:
+    case RAB_GSAB_FLOAT64_ELEMENTS:
+    case RAB_GSAB_BIGINT64_ELEMENTS:
+    case RAB_GSAB_BIGUINT64_ELEMENTS:
       return 3;
     case PACKED_SMI_ELEMENTS:
     case PACKED_ELEMENTS:
@@ -109,6 +120,7 @@ const char* ElementsKindToString(ElementsKind kind) {
     return #TYPE "ELEMENTS";
 
       TYPED_ARRAYS(PRINT_NAME);
+      RAB_GSAB_TYPED_ARRAYS(PRINT_NAME);
 #undef PRINT_NAME
     case NO_ELEMENTS:
       return "NO_ELEMENTS";
diff --git a/chromium/v8/src/objects/elements-kind.h b/chromium/v8/src/objects/elements-kind.h
index ec3ca3402d1..b19e21136f3 100644
--- a/chromium/v8/src/objects/elements-kind.h
+++ b/chromium/v8/src/objects/elements-kind.h
@@ -28,6 +28,36 @@ namespace internal {
   V(BigUint64, biguint64, BIGUINT64, uint64_t)           \
   V(BigInt64, bigint64, BIGINT64, int64_t)
 
+#define RAB_GSAB_TYPED_ARRAYS(V)                                         \
+  V(RabGsabUint8, rab_gsab_uint8, RAB_GSAB_UINT8, uint8_t)               \
+  V(RabGsabInt8, rab_gsab_int8, RAB_GSAB_INT8, int8_t)                   \
+  V(RabGsabUint16, rab_gsab_uint16, RAB_GSAB_UINT16, uint16_t)           \
+  V(RabGsabInt16, rab_gsab_int16, RAB_GSAB_INT16, int16_t)               \
+  V(RabGsabUint32, rab_gsab_uint32, RAB_GSAB_UINT32, uint32_t)           \
+  V(RabGsabInt32, rab_gsab_int32, RAB_GSAB_INT32, int32_t)               \
+  V(RabGsabFloat32, rab_gsab_float32, RAB_GSAB_FLOAT32, float)           \
+  V(RabGsabFloat64, rab_gsab_float64, RAB_GSAB_FLOAT64, double)          \
+  V(RabGsabUint8Clamped, rab_gsab_uint8_clamped, RAB_GSAB_UINT8_CLAMPED, \
+    uint8_t)                                                             \
+  V(RabGsabBigUint64, rab_gsab_biguint64, RAB_GSAB_BIGUINT64, uint64_t)  \
+  V(RabGsabBigInt64, rab_gsab_bigint64, RAB_GSAB_BIGINT64, int64_t)
+
+// The TypedArrays backed by RAB / GSAB are called Uint8Array, Uint16Array etc,
+// and not RabGsabUint8Array, RabGsabUint16Array etc. This macro is used for
+// generating code which refers to the TypedArray type.
+#define RAB_GSAB_TYPED_ARRAYS_WITH_TYPED_ARRAY_TYPE(V)                     \
+  V(Uint8, rab_gsab_uint8, RAB_GSAB_UINT8, uint8_t)                        \
+  V(Int8, rab_gsab_int8, RAB_GSAB_INT8, int8_t)                            \
+  V(Uint16, rab_gsab_uint16, RAB_GSAB_UINT16, uint16_t)                    \
+  V(Int16, rab_gsab_int16, RAB_GSAB_INT16, int16_t)                        \
+  V(Uint32, rab_gsab_uint32, RAB_GSAB_UINT32, uint32_t)                    \
+  V(Int32, rab_gsab_int32, RAB_GSAB_INT32, int32_t)                        \
+  V(Float32, rab_gsab_float32, RAB_GSAB_FLOAT32, float)                    \
+  V(Float64, rab_gsab_float64, RAB_GSAB_FLOAT64, double)                   \
+  V(Uint8Clamped, rab_gsab_uint8_clamped, RAB_GSAB_UINT8_CLAMPED, uint8_t) \
+  V(BigUint64, rab_gsab_biguint64, RAB_GSAB_BIGUINT64, uint64_t)           \
+  V(BigInt64, rab_gsab_bigint64, RAB_GSAB_BIGINT64, int64_t)
+
 enum ElementsKind : uint8_t {
   // The "fast" kind for elements that only contain SMI values. Must be first
   // to make it possible to efficiently check maps for this kind.
@@ -71,6 +101,7 @@ enum ElementsKind : uint8_t {
 // Fixed typed arrays.
 #define TYPED_ARRAY_ELEMENTS_KIND(Type, type, TYPE, ctype) TYPE##_ELEMENTS,
   TYPED_ARRAYS(TYPED_ARRAY_ELEMENTS_KIND)
+      RAB_GSAB_TYPED_ARRAYS(TYPED_ARRAY_ELEMENTS_KIND)
 #undef TYPED_ARRAY_ELEMENTS_KIND
 
   // Sentinel ElementsKind for objects with no elements.
@@ -78,11 +109,13 @@ enum ElementsKind : uint8_t {
 
   // Derived constants from ElementsKind.
   FIRST_ELEMENTS_KIND = PACKED_SMI_ELEMENTS,
-  LAST_ELEMENTS_KIND = BIGINT64_ELEMENTS,
+  LAST_ELEMENTS_KIND = RAB_GSAB_BIGINT64_ELEMENTS,
   FIRST_FAST_ELEMENTS_KIND = PACKED_SMI_ELEMENTS,
   LAST_FAST_ELEMENTS_KIND = HOLEY_DOUBLE_ELEMENTS,
   FIRST_FIXED_TYPED_ARRAY_ELEMENTS_KIND = UINT8_ELEMENTS,
   LAST_FIXED_TYPED_ARRAY_ELEMENTS_KIND = BIGINT64_ELEMENTS,
+  FIRST_RAB_GSAB_FIXED_TYPED_ARRAY_ELEMENTS_KIND = RAB_GSAB_UINT8_ELEMENTS,
+  LAST_RAB_GSAB_FIXED_TYPED_ARRAY_ELEMENTS_KIND = RAB_GSAB_BIGINT64_ELEMENTS,
   TERMINAL_FAST_ELEMENTS_KIND = HOLEY_ELEMENTS,
   FIRST_ANY_NONEXTENSIBLE_ELEMENTS_KIND = PACKED_NONEXTENSIBLE_ELEMENTS,
   LAST_ANY_NONEXTENSIBLE_ELEMENTS_KIND = HOLEY_FROZEN_ELEMENTS,
@@ -103,7 +136,7 @@ constexpr int kFastElementsKindCount =
 constexpr int kFastElementsKindPackedToHoley =
     HOLEY_SMI_ELEMENTS - PACKED_SMI_ELEMENTS;
 
-constexpr int kElementsKindBits = 5;
+constexpr int kElementsKindBits = 6;
 STATIC_ASSERT((1 << kElementsKindBits) > LAST_ELEMENTS_KIND);
 STATIC_ASSERT((1 << (kElementsKindBits - 1)) <= LAST_ELEMENTS_KIND);
 
@@ -150,8 +183,20 @@ inline bool IsTypedArrayElementsKind(ElementsKind kind) {
                          LAST_FIXED_TYPED_ARRAY_ELEMENTS_KIND);
 }
 
+inline bool IsRabGsabTypedArrayElementsKind(ElementsKind kind) {
+  return base::IsInRange(kind, FIRST_RAB_GSAB_FIXED_TYPED_ARRAY_ELEMENTS_KIND,
+                         LAST_RAB_GSAB_FIXED_TYPED_ARRAY_ELEMENTS_KIND);
+}
+
+inline bool IsTypedArrayOrRabGsabTypedArrayElementsKind(ElementsKind kind) {
+  return base::IsInRange(kind, FIRST_FIXED_TYPED_ARRAY_ELEMENTS_KIND,
+                         LAST_RAB_GSAB_FIXED_TYPED_ARRAY_ELEMENTS_KIND);
+}
+
 inline bool IsTerminalElementsKind(ElementsKind kind) {
-  return kind == TERMINAL_FAST_ELEMENTS_KIND || IsTypedArrayElementsKind(kind);
+  return kind == TERMINAL_FAST_ELEMENTS_KIND ||
+         IsTypedArrayElementsKind(kind) ||
+         IsRabGsabTypedArrayElementsKind(kind);
 }
 
 inline bool IsFastElementsKind(ElementsKind kind) {
@@ -281,6 +326,13 @@ inline ElementsKind GetHoleyElementsKind(ElementsKind packed_kind) {
   return packed_kind;
 }
 
+inline ElementsKind GetCorrespondingRabGsabElementsKind(
+    ElementsKind typed_array_kind) {
+  DCHECK(IsTypedArrayElementsKind(typed_array_kind));
+  return ElementsKind(typed_array_kind - FIRST_FIXED_TYPED_ARRAY_ELEMENTS_KIND +
+                      FIRST_RAB_GSAB_FIXED_TYPED_ARRAY_ELEMENTS_KIND);
+}
+
 inline bool UnionElementsKindUptoPackedness(ElementsKind* a_out,
                                             ElementsKind b) {
   // Assert that the union of two ElementKinds can be computed via std::max.
diff --git a/chromium/v8/src/objects/elements.cc b/chromium/v8/src/objects/elements.cc
index 9b1c7936bb6..e70ae489008 100644
--- a/chromium/v8/src/objects/elements.cc
+++ b/chromium/v8/src/objects/elements.cc
@@ -4,6 +4,7 @@
 
 #include "src/objects/elements.h"
 
+#include "src/base/atomicops.h"
 #include "src/common/message-template.h"
 #include "src/execution/arguments.h"
 #include "src/execution/frames.h"
@@ -59,6 +60,17 @@
 //     - Uint8ClampedElementsAccessor
 //     - BigUint64ElementsAccessor
 //     - BigInt64ElementsAccessor
+//     - RabGsabUint8ElementsAccessor
+//     - RabGsabInt8ElementsAccessor
+//     - RabGsabUint16ElementsAccessor
+//     - RabGsabInt16ElementsAccessor
+//     - RabGsabUint32ElementsAccessor
+//     - RabGsabInt32ElementsAccessor
+//     - RabGsabFloat32ElementsAccessor
+//     - RabGsabFloat64ElementsAccessor
+//     - RabGsabUint8ClampedElementsAccessor
+//     - RabGsabBigUint64ElementsAccessor
+//     - RabGsabBigInt64ElementsAccessor
 //   - DictionaryElementsAccessor
 //   - SloppyArgumentsElementsAccessor
 //     - FastSloppyArgumentsElementsAccessor
@@ -129,7 +141,19 @@ enum Where { AT_START, AT_END };
   V(Float64ElementsAccessor, FLOAT64_ELEMENTS, ByteArray)                     \
   V(Uint8ClampedElementsAccessor, UINT8_CLAMPED_ELEMENTS, ByteArray)          \
   V(BigUint64ElementsAccessor, BIGUINT64_ELEMENTS, ByteArray)                 \
-  V(BigInt64ElementsAccessor, BIGINT64_ELEMENTS, ByteArray)
+  V(BigInt64ElementsAccessor, BIGINT64_ELEMENTS, ByteArray)                   \
+  V(RabGsabUint8ElementsAccessor, RAB_GSAB_UINT8_ELEMENTS, ByteArray)         \
+  V(RabGsabInt8ElementsAccessor, RAB_GSAB_INT8_ELEMENTS, ByteArray)           \
+  V(RabGsabUint16ElementsAccessor, RAB_GSAB_UINT16_ELEMENTS, ByteArray)       \
+  V(RabGsabInt16ElementsAccessor, RAB_GSAB_INT16_ELEMENTS, ByteArray)         \
+  V(RabGsabUint32ElementsAccessor, RAB_GSAB_UINT32_ELEMENTS, ByteArray)       \
+  V(RabGsabInt32ElementsAccessor, RAB_GSAB_INT32_ELEMENTS, ByteArray)         \
+  V(RabGsabFloat32ElementsAccessor, RAB_GSAB_FLOAT32_ELEMENTS, ByteArray)     \
+  V(RabGsabFloat64ElementsAccessor, RAB_GSAB_FLOAT64_ELEMENTS, ByteArray)     \
+  V(RabGsabUint8ClampedElementsAccessor, RAB_GSAB_UINT8_CLAMPED_ELEMENTS,     \
+    ByteArray)                                                                \
+  V(RabGsabBigUint64ElementsAccessor, RAB_GSAB_BIGUINT64_ELEMENTS, ByteArray) \
+  V(RabGsabBigInt64ElementsAccessor, RAB_GSAB_BIGINT64_ELEMENTS, ByteArray)
 
 template <ElementsKind Kind>
 class ElementsKindTraits {
@@ -639,57 +663,64 @@ class ElementsAccessorBase : public InternalElementsAccessor {
     UNREACHABLE();
   }
 
-  void Add(Handle<JSObject> object, uint32_t index, Handle<Object> value,
-           PropertyAttributes attributes, uint32_t new_capacity) final {
-    Subclass::AddImpl(object, index, value, attributes, new_capacity);
+  Maybe<bool> Add(Handle<JSObject> object, uint32_t index, Handle<Object> value,
+                  PropertyAttributes attributes, uint32_t new_capacity) final {
+    return Subclass::AddImpl(object, index, value, attributes, new_capacity);
   }
 
-  static void AddImpl(Handle<JSObject> object, uint32_t index,
-                      Handle<Object> value, PropertyAttributes attributes,
-                      uint32_t new_capacity) {
+  static Maybe<bool> AddImpl(Handle<JSObject> object, uint32_t index,
+                             Handle<Object> value,
+                             PropertyAttributes attributes,
+                             uint32_t new_capacity) {
     UNREACHABLE();
   }
 
-  uint32_t Push(Handle<JSArray> receiver, BuiltinArguments* args,
-                uint32_t push_size) final {
+  Maybe<uint32_t> Push(Handle<JSArray> receiver, BuiltinArguments* args,
+                       uint32_t push_size) final {
     return Subclass::PushImpl(receiver, args, push_size);
   }
 
-  static uint32_t PushImpl(Handle<JSArray> receiver, BuiltinArguments* args,
-                           uint32_t push_sized) {
+  static Maybe<uint32_t> PushImpl(Handle<JSArray> receiver,
+                                  BuiltinArguments* args, uint32_t push_sized) {
     UNREACHABLE();
   }
 
-  uint32_t Unshift(Handle<JSArray> receiver, BuiltinArguments* args,
-                   uint32_t unshift_size) final {
+  Maybe<uint32_t> Unshift(Handle<JSArray> receiver, BuiltinArguments* args,
+                          uint32_t unshift_size) final {
     return Subclass::UnshiftImpl(receiver, args, unshift_size);
   }
 
-  static uint32_t UnshiftImpl(Handle<JSArray> receiver, BuiltinArguments* args,
-                              uint32_t unshift_size) {
+  static Maybe<uint32_t> UnshiftImpl(Handle<JSArray> receiver,
+                                     BuiltinArguments* args,
+                                     uint32_t unshift_size) {
     UNREACHABLE();
   }
 
-  Handle<Object> Pop(Handle<JSArray> receiver) final {
+  MaybeHandle<Object> Pop(Handle<JSArray> receiver) final {
     return Subclass::PopImpl(receiver);
   }
 
-  static Handle<Object> PopImpl(Handle<JSArray> receiver) { UNREACHABLE(); }
+  static MaybeHandle<Object> PopImpl(Handle<JSArray> receiver) {
+    UNREACHABLE();
+  }
 
-  Handle<Object> Shift(Handle<JSArray> receiver) final {
+  MaybeHandle<Object> Shift(Handle<JSArray> receiver) final {
     return Subclass::ShiftImpl(receiver);
   }
 
-  static Handle<Object> ShiftImpl(Handle<JSArray> receiver) { UNREACHABLE(); }
+  static MaybeHandle<Object> ShiftImpl(Handle<JSArray> receiver) {
+    UNREACHABLE();
+  }
 
-  void SetLength(Handle<JSArray> array, uint32_t length) final {
-    Subclass::SetLengthImpl(array->GetIsolate(), array, length,
-                            handle(array->elements(), array->GetIsolate()));
+  Maybe<bool> SetLength(Handle<JSArray> array, uint32_t length) final {
+    return Subclass::SetLengthImpl(
+        array->GetIsolate(), array, length,
+        handle(array->elements(), array->GetIsolate()));
   }
 
-  static void SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
-                            uint32_t length,
-                            Handle<FixedArrayBase> backing_store) {
+  static Maybe<bool> SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
+                                   uint32_t length,
+                                   Handle<FixedArrayBase> backing_store) {
     DCHECK(!array->SetLengthWouldNormalize(length));
     DCHECK(IsFastElementsKind(array->GetElementsKind()));
     uint32_t old_length = 0;
@@ -735,11 +766,13 @@ class ElementsAccessorBase : public InternalElementsAccessor {
     } else {
       // Check whether the backing store should be expanded.
       capacity = std::max(length, JSObject::NewElementsCapacity(capacity));
-      Subclass::GrowCapacityAndConvertImpl(array, capacity);
+      MAYBE_RETURN(Subclass::GrowCapacityAndConvertImpl(array, capacity),
+                   Nothing<bool>());
     }
 
     array->set_length(Smi::FromInt(length));
     JSObject::ValidateElements(*array);
+    return Just(true);
   }
 
   size_t NumberOfElements(JSObject receiver) final {
@@ -765,23 +798,35 @@ class ElementsAccessorBase : public InternalElementsAccessor {
     return Subclass::GetMaxIndex(receiver, elements);
   }
 
-  static Handle<FixedArrayBase> ConvertElementsWithCapacity(
+  static MaybeHandle<FixedArrayBase> ConvertElementsWithCapacity(
       Handle<JSObject> object, Handle<FixedArrayBase> old_elements,
       ElementsKind from_kind, uint32_t capacity) {
     return ConvertElementsWithCapacity(object, old_elements, from_kind,
                                        capacity, 0, 0);
   }
 
-  static Handle<FixedArrayBase> ConvertElementsWithCapacity(
+  static MaybeHandle<FixedArrayBase> ConvertElementsWithCapacity(
       Handle<JSObject> object, Handle<FixedArrayBase> old_elements,
       ElementsKind from_kind, uint32_t capacity, uint32_t src_index,
       uint32_t dst_index) {
     Isolate* isolate = object->GetIsolate();
     Handle<FixedArrayBase> new_elements;
+    // TODO(victorgomes): Retrieve native context in optimized code
+    // and remove the check isolate->context().is_null().
     if (IsDoubleElementsKind(kind())) {
+      if (!isolate->context().is_null() &&
+          !base::IsInRange(capacity, 0, FixedDoubleArray::kMaxLength)) {
+        return isolate->Throw<FixedArrayBase>(isolate->factory()->NewRangeError(
+            MessageTemplate::kInvalidArrayLength));
+      }
       new_elements = isolate->factory()->NewFixedDoubleArray(capacity);
     } else {
-      new_elements = isolate->factory()->NewUninitializedFixedArray(capacity);
+      if (!isolate->context().is_null() &&
+          !base::IsInRange(capacity, 0, FixedArray::kMaxLength)) {
+        return isolate->Throw<FixedArrayBase>(isolate->factory()->NewRangeError(
+            MessageTemplate::kInvalidArrayLength));
+      }
+      new_elements = isolate->factory()->NewFixedArray(capacity);
     }
 
     int packed_size = kPackedSizeNotKnown;
@@ -793,11 +838,11 @@ class ElementsAccessorBase : public InternalElementsAccessor {
                                from_kind, dst_index, packed_size,
                                kCopyToEndAndInitializeToHole);
 
-    return new_elements;
+    return MaybeHandle<FixedArrayBase>(new_elements);
   }
 
-  static void TransitionElementsKindImpl(Handle<JSObject> object,
-                                         Handle<Map> to_map) {
+  static Maybe<bool> TransitionElementsKindImpl(Handle<JSObject> object,
+                                                Handle<Map> to_map) {
     Isolate* isolate = object->GetIsolate();
     Handle<Map> from_map = handle(object->map(), isolate);
     ElementsKind from_kind = from_map->elements_kind();
@@ -822,8 +867,12 @@ class ElementsAccessorBase : public InternalElementsAccessor {
             (IsSmiElementsKind(from_kind) && IsDoubleElementsKind(to_kind)) ||
             (IsDoubleElementsKind(from_kind) && IsObjectElementsKind(to_kind)));
         uint32_t capacity = static_cast<uint32_t>(object->elements().length());
-        Handle<FixedArrayBase> elements = ConvertElementsWithCapacity(
-            object, from_elements, from_kind, capacity);
+        Handle<FixedArrayBase> elements;
+        ASSIGN_RETURN_ON_EXCEPTION_VALUE(
+            object->GetIsolate(), elements,
+            ConvertElementsWithCapacity(object, from_elements, from_kind,
+                                        capacity),
+            Nothing<bool>());
         JSObject::SetMapAndElements(object, to_map, elements);
       }
       if (FLAG_trace_elements_transitions) {
@@ -832,10 +881,11 @@ class ElementsAccessorBase : public InternalElementsAccessor {
                                           handle(object->elements(), isolate));
       }
     }
+    return Just(true);
   }
 
-  static void GrowCapacityAndConvertImpl(Handle<JSObject> object,
-                                         uint32_t capacity) {
+  static Maybe<bool> GrowCapacityAndConvertImpl(Handle<JSObject> object,
+                                                uint32_t capacity) {
     ElementsKind from_kind = object->GetElementsKind();
     if (IsSmiOrObjectElementsKind(from_kind)) {
       // Array optimizations rely on the prototype lookups of Array objects
@@ -850,15 +900,18 @@ class ElementsAccessorBase : public InternalElementsAccessor {
     DCHECK(IsDoubleElementsKind(from_kind) != IsDoubleElementsKind(kind()) ||
            IsDictionaryElementsKind(from_kind) ||
            static_cast<uint32_t>(old_elements->length()) < capacity);
-    Subclass::BasicGrowCapacityAndConvertImpl(object, old_elements, from_kind,
-                                              kind(), capacity);
+    return Subclass::BasicGrowCapacityAndConvertImpl(
+        object, old_elements, from_kind, kind(), capacity);
   }
 
-  static void BasicGrowCapacityAndConvertImpl(
+  static Maybe<bool> BasicGrowCapacityAndConvertImpl(
       Handle<JSObject> object, Handle<FixedArrayBase> old_elements,
       ElementsKind from_kind, ElementsKind to_kind, uint32_t capacity) {
-    Handle<FixedArrayBase> elements =
-        ConvertElementsWithCapacity(object, old_elements, from_kind, capacity);
+    Handle<FixedArrayBase> elements;
+    ASSIGN_RETURN_ON_EXCEPTION_VALUE(
+        object->GetIsolate(), elements,
+        ConvertElementsWithCapacity(object, old_elements, from_kind, capacity),
+        Nothing<bool>());
 
     if (IsHoleyElementsKind(from_kind)) {
       to_kind = GetHoleyElementsKind(to_kind);
@@ -873,40 +926,45 @@ class ElementsAccessorBase : public InternalElementsAccessor {
       JSObject::PrintElementsTransition(stdout, object, from_kind, old_elements,
                                         to_kind, elements);
     }
+    return Just(true);
   }
 
-  void TransitionElementsKind(Handle<JSObject> object, Handle<Map> map) final {
-    Subclass::TransitionElementsKindImpl(object, map);
+  Maybe<bool> TransitionElementsKind(Handle<JSObject> object,
+                                     Handle<Map> map) final {
+    return Subclass::TransitionElementsKindImpl(object, map);
   }
 
-  void GrowCapacityAndConvert(Handle<JSObject> object,
-                              uint32_t capacity) final {
-    Subclass::GrowCapacityAndConvertImpl(object, capacity);
+  Maybe<bool> GrowCapacityAndConvert(Handle<JSObject> object,
+                                     uint32_t capacity) final {
+    return Subclass::GrowCapacityAndConvertImpl(object, capacity);
   }
 
-  bool GrowCapacity(Handle<JSObject> object, uint32_t index) final {
+  Maybe<bool> GrowCapacity(Handle<JSObject> object, uint32_t index) final {
     // This function is intended to be called from optimized code. We don't
     // want to trigger lazy deopts there, so refuse to handle cases that would.
     if (object->map().is_prototype_map() ||
         object->WouldConvertToSlowElements(index)) {
-      return false;
+      return Just(false);
     }
     Handle<FixedArrayBase> old_elements(object->elements(),
                                         object->GetIsolate());
     uint32_t new_capacity = JSObject::NewElementsCapacity(index + 1);
     DCHECK(static_cast<uint32_t>(old_elements->length()) < new_capacity);
-    Handle<FixedArrayBase> elements =
-        ConvertElementsWithCapacity(object, old_elements, kind(), new_capacity);
+    Handle<FixedArrayBase> elements;
+    ASSIGN_RETURN_ON_EXCEPTION_VALUE(
+        object->GetIsolate(), elements,
+        ConvertElementsWithCapacity(object, old_elements, kind(), new_capacity),
+        Nothing<bool>());
 
     DCHECK_EQ(object->GetElementsKind(), kind());
     // Transition through the allocation site as well if present.
     if (JSObject::UpdateAllocationSite<AllocationSiteUpdateMode::kCheckOnly>(
             object, kind())) {
-      return false;
+      return Just(false);
     }
 
     object->set_elements(*elements);
-    return true;
+    return Just(true);
   }
 
   void Delete(Handle<JSObject> obj, InternalIndex entry) final {
@@ -1220,13 +1278,14 @@ class ElementsAccessorBase : public InternalElementsAccessor {
     return Subclass::GetCapacityImpl(holder, backing_store);
   }
 
-  static Object FillImpl(Handle<JSObject> receiver, Handle<Object> obj_value,
-                         size_t start, size_t end) {
+  static MaybeHandle<Object> FillImpl(Handle<JSObject> receiver,
+                                      Handle<Object> obj_value, size_t start,
+                                      size_t end) {
     UNREACHABLE();
   }
 
-  Object Fill(Handle<JSObject> receiver, Handle<Object> obj_value, size_t start,
-              size_t end) override {
+  MaybeHandle<Object> Fill(Handle<JSObject> receiver, Handle<Object> obj_value,
+                           size_t start, size_t end) override {
     return Subclass::FillImpl(receiver, obj_value, start, end);
   }
 
@@ -1348,9 +1407,9 @@ class DictionaryElementsAccessor
     return dict.NumberOfElements();
   }
 
-  static void SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
-                            uint32_t length,
-                            Handle<FixedArrayBase> backing_store) {
+  static Maybe<bool> SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
+                                   uint32_t length,
+                                   Handle<FixedArrayBase> backing_store) {
     Handle<NumberDictionary> dict =
         Handle<NumberDictionary>::cast(backing_store);
     uint32_t old_length = 0;
@@ -1401,6 +1460,7 @@ class DictionaryElementsAccessor
 
     Handle<Object> length_obj = isolate->factory()->NewNumberFromUint(length);
     array->set_length(*length_obj);
+    return Just(true);
   }
 
   static void CopyElementsImpl(Isolate* isolate, FixedArrayBase from,
@@ -1466,9 +1526,10 @@ class DictionaryElementsAccessor
     dictionary.DetailsAtPut(entry, details);
   }
 
-  static void AddImpl(Handle<JSObject> object, uint32_t index,
-                      Handle<Object> value, PropertyAttributes attributes,
-                      uint32_t new_capacity) {
+  static Maybe<bool> AddImpl(Handle<JSObject> object, uint32_t index,
+                             Handle<Object> value,
+                             PropertyAttributes attributes,
+                             uint32_t new_capacity) {
     PropertyDetails details(kData, attributes, PropertyCellType::kNoCell);
     Handle<NumberDictionary> dictionary =
         object->HasFastElements() || object->HasFastStringWrapperElements()
@@ -1479,8 +1540,9 @@ class DictionaryElementsAccessor
         object->GetIsolate(), dictionary, index, value, details);
     new_dictionary->UpdateMaxNumberKey(index, object);
     if (attributes != NONE) object->RequireSlowElements(*new_dictionary);
-    if (dictionary.is_identical_to(new_dictionary)) return;
+    if (dictionary.is_identical_to(new_dictionary)) return Just(true);
     object->set_elements(*new_dictionary);
+    return Just(true);
   }
 
   static bool HasEntryImpl(Isolate* isolate, FixedArrayBase store,
@@ -1904,12 +1966,10 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
     backing_store->set_the_hole(isolate, entry);
 
     // TODO(verwaest): Move this out of elements.cc.
-    // If an old space backing store is larger than a certain size and
+    // If the backing store is larger than a certain size and
     // has too few used values, normalize it.
     const int kMinLengthForSparsenessCheck = 64;
     if (backing_store->length() < kMinLengthForSparsenessCheck) return;
-    // TODO(ulan): Check if it works with young large objects.
-    if (ObjectInYoungGeneration(*backing_store)) return;
     uint32_t length = 0;
     if (obj->IsJSArray()) {
       JSArray::cast(*obj).length().ToArrayLength(&length);
@@ -1971,9 +2031,10 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
                                                 value, attributes);
   }
 
-  static void AddImpl(Handle<JSObject> object, uint32_t index,
-                      Handle<Object> value, PropertyAttributes attributes,
-                      uint32_t new_capacity) {
+  static Maybe<bool> AddImpl(Handle<JSObject> object, uint32_t index,
+                             Handle<Object> value,
+                             PropertyAttributes attributes,
+                             uint32_t new_capacity) {
     DCHECK_EQ(NONE, attributes);
     ElementsKind from_kind = object->GetElementsKind();
     ElementsKind to_kind = Subclass::kind();
@@ -1981,7 +2042,8 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
         IsDoubleElementsKind(from_kind) != IsDoubleElementsKind(to_kind) ||
         Subclass::GetCapacityImpl(*object, object->elements()) !=
             new_capacity) {
-      Subclass::GrowCapacityAndConvertImpl(object, new_capacity);
+      MAYBE_RETURN(Subclass::GrowCapacityAndConvertImpl(object, new_capacity),
+                   Nothing<bool>());
     } else {
       if (IsFastElementsKind(from_kind) && from_kind != to_kind) {
         JSObject::TransitionElementsKind(object, to_kind);
@@ -1992,6 +2054,7 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
       }
     }
     Subclass::SetImpl(object, InternalIndex(index), *value);
+    return Just(true);
   }
 
   static void DeleteImpl(Handle<JSObject> obj, InternalIndex entry) {
@@ -2086,24 +2149,25 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
 #endif
   }
 
-  static Handle<Object> PopImpl(Handle<JSArray> receiver) {
+  static MaybeHandle<Object> PopImpl(Handle<JSArray> receiver) {
     return Subclass::RemoveElement(receiver, AT_END);
   }
 
-  static Handle<Object> ShiftImpl(Handle<JSArray> receiver) {
+  static MaybeHandle<Object> ShiftImpl(Handle<JSArray> receiver) {
     return Subclass::RemoveElement(receiver, AT_START);
   }
 
-  static uint32_t PushImpl(Handle<JSArray> receiver, BuiltinArguments* args,
-                           uint32_t push_size) {
+  static Maybe<uint32_t> PushImpl(Handle<JSArray> receiver,
+                                  BuiltinArguments* args, uint32_t push_size) {
     Handle<FixedArrayBase> backing_store(receiver->elements(),
                                          receiver->GetIsolate());
     return Subclass::AddArguments(receiver, backing_store, args, push_size,
                                   AT_END);
   }
 
-  static uint32_t UnshiftImpl(Handle<JSArray> receiver, BuiltinArguments* args,
-                              uint32_t unshift_size) {
+  static Maybe<uint32_t> UnshiftImpl(Handle<JSArray> receiver,
+                                     BuiltinArguments* args,
+                                     uint32_t unshift_size) {
     Handle<FixedArrayBase> backing_store(receiver->elements(),
                                          receiver->GetIsolate());
     return Subclass::AddArguments(receiver, backing_store, args, unshift_size,
@@ -2137,8 +2201,9 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
     }
   }
 
-  static Object FillImpl(Handle<JSObject> receiver, Handle<Object> obj_value,
-                         size_t start, size_t end) {
+  static MaybeHandle<Object> FillImpl(Handle<JSObject> receiver,
+                                      Handle<Object> obj_value, size_t start,
+                                      size_t end) {
     // Ensure indexes are within array bounds
     DCHECK_LE(0, start);
     DCHECK_LE(start, end);
@@ -2151,8 +2216,8 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
     // Make sure we have enough space.
     DCHECK_LE(end, std::numeric_limits<uint32_t>::max());
     if (end > Subclass::GetCapacityImpl(*receiver, receiver->elements())) {
-      Subclass::GrowCapacityAndConvertImpl(receiver,
-                                           static_cast<uint32_t>(end));
+      MAYBE_RETURN_NULL(Subclass::GrowCapacityAndConvertImpl(
+          receiver, static_cast<uint32_t>(end)));
       CHECK_EQ(Subclass::kind(), receiver->GetElementsKind());
     }
     DCHECK_LE(end, Subclass::GetCapacityImpl(*receiver, receiver->elements()));
@@ -2160,7 +2225,7 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
     for (size_t index = start; index < end; ++index) {
       Subclass::SetImpl(receiver, InternalIndex(index), *obj_value);
     }
-    return *receiver;
+    return MaybeHandle<Object>(receiver);
   }
 
   static Maybe<bool> IncludesValueImpl(Isolate* isolate,
@@ -2322,8 +2387,8 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
     return result;
   }
 
-  static Handle<Object> RemoveElement(Handle<JSArray> receiver,
-                                      Where remove_position) {
+  static MaybeHandle<Object> RemoveElement(Handle<JSArray> receiver,
+                                           Where remove_position) {
     Isolate* isolate = receiver->GetIsolate();
     ElementsKind kind = KindTraits::Kind;
     if (IsSmiOrObjectElementsKind(kind)) {
@@ -2341,24 +2406,26 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
       Subclass::MoveElements(isolate, receiver, backing_store, 0, 1, new_length,
                              0, 0);
     }
-    Subclass::SetLengthImpl(isolate, receiver, new_length, backing_store);
+    MAYBE_RETURN_NULL(
+        Subclass::SetLengthImpl(isolate, receiver, new_length, backing_store));
 
     if (IsHoleyElementsKind(kind) && result->IsTheHole(isolate)) {
       return isolate->factory()->undefined_value();
     }
-    return result;
+    return MaybeHandle<Object>(result);
   }
 
-  static uint32_t AddArguments(Handle<JSArray> receiver,
-                               Handle<FixedArrayBase> backing_store,
-                               BuiltinArguments* args, uint32_t add_size,
-                               Where add_position) {
+  static Maybe<uint32_t> AddArguments(Handle<JSArray> receiver,
+                                      Handle<FixedArrayBase> backing_store,
+                                      BuiltinArguments* args, uint32_t add_size,
+                                      Where add_position) {
     uint32_t length = Smi::ToInt(receiver->length());
     DCHECK_LT(0, add_size);
     uint32_t elms_len = backing_store->length();
     // Check we do not overflow the new_length.
     DCHECK(add_size <= static_cast<uint32_t>(Smi::kMaxValue - length));
     uint32_t new_length = length + add_size;
+    Isolate* isolate = receiver->GetIsolate();
 
     if (new_length > elms_len) {
       // New backing storage is needed.
@@ -2366,14 +2433,16 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
       // If we add arguments to the start we have to shift the existing objects.
       int copy_dst_index = add_position == AT_START ? add_size : 0;
       // Copy over all objects to a new backing_store.
-      backing_store = Subclass::ConvertElementsWithCapacity(
-          receiver, backing_store, KindTraits::Kind, capacity, 0,
-          copy_dst_index);
+      ASSIGN_RETURN_ON_EXCEPTION_VALUE(
+          isolate, backing_store,
+          Subclass::ConvertElementsWithCapacity(receiver, backing_store,
+                                                KindTraits::Kind, capacity, 0,
+                                                copy_dst_index),
+          Nothing<uint32_t>());
       receiver->set_elements(*backing_store);
     } else if (add_position == AT_START) {
       // If the backing store has enough capacity and we add elements to the
       // start we have to shift the existing objects.
-      Isolate* isolate = receiver->GetIsolate();
       Subclass::MoveElements(isolate, receiver, backing_store, add_size, 0,
                              length, 0, 0);
     }
@@ -2383,7 +2452,7 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
     Subclass::CopyArguments(args, backing_store, add_size, 1, insertion_index);
     // Set the length.
     receiver->set_length(Smi::FromInt(new_length));
-    return new_length;
+    return Just(new_length);
   }
 
   static void CopyArguments(BuiltinArguments* args,
@@ -2469,6 +2538,7 @@ class FastSmiOrObjectElementsAccessor
       case SLOW_STRING_WRAPPER_ELEMENTS:
 #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) case TYPE##_ELEMENTS:
         TYPED_ARRAYS(TYPED_ARRAY_CASE)
+        RAB_GSAB_TYPED_ARRAYS(TYPED_ARRAY_CASE)
 #undef TYPED_ARRAY_CASE
         // This function is currently only used for JSArrays with non-zero
         // length.
@@ -2569,28 +2639,29 @@ class FastNonextensibleObjectElementsAccessor
  public:
   using BackingStore = typename KindTraits::BackingStore;
 
-  static uint32_t PushImpl(Handle<JSArray> receiver, BuiltinArguments* args,
-                           uint32_t push_size) {
+  static Maybe<uint32_t> PushImpl(Handle<JSArray> receiver,
+                                  BuiltinArguments* args, uint32_t push_size) {
     UNREACHABLE();
   }
 
-  static void AddImpl(Handle<JSObject> object, uint32_t index,
-                      Handle<Object> value, PropertyAttributes attributes,
-                      uint32_t new_capacity) {
+  static Maybe<bool> AddImpl(Handle<JSObject> object, uint32_t index,
+                             Handle<Object> value,
+                             PropertyAttributes attributes,
+                             uint32_t new_capacity) {
     UNREACHABLE();
   }
 
   // TODO(duongn): refactor this due to code duplication of sealed version.
   // Consider using JSObject::NormalizeElements(). Also consider follow the fast
   // element logic instead of changing to dictionary mode.
-  static void SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
-                            uint32_t length,
-                            Handle<FixedArrayBase> backing_store) {
+  static Maybe<bool> SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
+                                   uint32_t length,
+                                   Handle<FixedArrayBase> backing_store) {
     uint32_t old_length = 0;
     CHECK(array->length().ToArrayIndex(&old_length));
     if (length == old_length) {
       // Do nothing.
-      return;
+      return Just(true);
     }
 
     // Transition to DICTIONARY_ELEMENTS.
@@ -2622,8 +2693,8 @@ class FastNonextensibleObjectElementsAccessor
 
     // Set length.
     Handle<FixedArrayBase> new_backing_store(array->elements(), isolate);
-    DictionaryElementsAccessor::SetLengthImpl(isolate, array, length,
-                                              new_backing_store);
+    return DictionaryElementsAccessor::SetLengthImpl(isolate, array, length,
+                                                     new_backing_store);
   }
 };
 
@@ -2662,30 +2733,33 @@ class FastSealedObjectElementsAccessor
     UNREACHABLE();
   }
 
-  static Handle<Object> PopImpl(Handle<JSArray> receiver) { UNREACHABLE(); }
+  static MaybeHandle<Object> PopImpl(Handle<JSArray> receiver) {
+    UNREACHABLE();
+  }
 
-  static uint32_t PushImpl(Handle<JSArray> receiver, BuiltinArguments* args,
-                           uint32_t push_size) {
+  static Maybe<uint32_t> PushImpl(Handle<JSArray> receiver,
+                                  BuiltinArguments* args, uint32_t push_size) {
     UNREACHABLE();
   }
 
-  static void AddImpl(Handle<JSObject> object, uint32_t index,
-                      Handle<Object> value, PropertyAttributes attributes,
-                      uint32_t new_capacity) {
+  static Maybe<bool> AddImpl(Handle<JSObject> object, uint32_t index,
+                             Handle<Object> value,
+                             PropertyAttributes attributes,
+                             uint32_t new_capacity) {
     UNREACHABLE();
   }
 
   // TODO(duongn): refactor this due to code duplication of nonextensible
   // version. Consider using JSObject::NormalizeElements(). Also consider follow
   // the fast element logic instead of changing to dictionary mode.
-  static void SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
-                            uint32_t length,
-                            Handle<FixedArrayBase> backing_store) {
+  static Maybe<bool> SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
+                                   uint32_t length,
+                                   Handle<FixedArrayBase> backing_store) {
     uint32_t old_length = 0;
     CHECK(array->length().ToArrayIndex(&old_length));
     if (length == old_length) {
       // Do nothing.
-      return;
+      return Just(true);
     }
 
     // Transition to DICTIONARY_ELEMENTS.
@@ -2717,8 +2791,8 @@ class FastSealedObjectElementsAccessor
 
     // Set length
     Handle<FixedArrayBase> new_backing_store(array->elements(), isolate);
-    DictionaryElementsAccessor::SetLengthImpl(isolate, array, length,
-                                              new_backing_store);
+    return DictionaryElementsAccessor::SetLengthImpl(isolate, array, length,
+                                                     new_backing_store);
   }
 };
 
@@ -2772,22 +2846,25 @@ class FastFrozenObjectElementsAccessor
     UNREACHABLE();
   }
 
-  static Handle<Object> PopImpl(Handle<JSArray> receiver) { UNREACHABLE(); }
+  static MaybeHandle<Object> PopImpl(Handle<JSArray> receiver) {
+    UNREACHABLE();
+  }
 
-  static uint32_t PushImpl(Handle<JSArray> receiver, BuiltinArguments* args,
-                           uint32_t push_size) {
+  static Maybe<uint32_t> PushImpl(Handle<JSArray> receiver,
+                                  BuiltinArguments* args, uint32_t push_size) {
     UNREACHABLE();
   }
 
-  static void AddImpl(Handle<JSObject> object, uint32_t index,
-                      Handle<Object> value, PropertyAttributes attributes,
-                      uint32_t new_capacity) {
+  static Maybe<bool> AddImpl(Handle<JSObject> object, uint32_t index,
+                             Handle<Object> value,
+                             PropertyAttributes attributes,
+                             uint32_t new_capacity) {
     UNREACHABLE();
   }
 
-  static void SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
-                            uint32_t length,
-                            Handle<FixedArrayBase> backing_store) {
+  static Maybe<bool> SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
+                                   uint32_t length,
+                                   Handle<FixedArrayBase> backing_store) {
     UNREACHABLE();
   }
 
@@ -2877,6 +2954,7 @@ class FastDoubleElementsAccessor
       case NO_ELEMENTS:
 #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) case TYPE##_ELEMENTS:
         TYPED_ARRAYS(TYPED_ARRAY_CASE)
+        RAB_GSAB_TYPED_ARRAYS(TYPED_ARRAY_CASE)
 #undef TYPED_ARRAY_CASE
         // This function is currently only used for JSArrays with non-zero
         // length.
@@ -2952,6 +3030,8 @@ class FastHoleyDoubleElementsAccessor
           FastHoleyDoubleElementsAccessor,
           ElementsKindTraits<HOLEY_DOUBLE_ELEMENTS>> {};
 
+enum IsSharedBuffer : bool { kShared = true, kUnshared = false };
+
 // Super class for all external element arrays.
 template <ElementsKind Kind, typename ElementType>
 class TypedElementsAccessor
@@ -2998,42 +3078,70 @@ class TypedElementsAccessor
   static void SetImpl(Handle<JSObject> holder, InternalIndex entry,
                       Object value) {
     Handle<JSTypedArray> typed_array = Handle<JSTypedArray>::cast(holder);
-    DCHECK_LE(entry.raw_value(), typed_array->length());
-    SetImpl(static_cast<ElementType*>(typed_array->DataPtr()),
-            entry.raw_value(), FromObject(value));
-  }
+    DCHECK_LE(entry.raw_value(), typed_array->GetLength());
+    auto* entry_ptr =
+        static_cast<ElementType*>(typed_array->DataPtr()) + entry.raw_value();
+    auto is_shared = typed_array->buffer().is_shared() ? kShared : kUnshared;
+    SetImpl(entry_ptr, FromObject(value), is_shared);
+  }
+
+  static void SetImpl(ElementType* data_ptr, ElementType value,
+                      IsSharedBuffer is_shared) {
+    // TODO(ishell, v8:8875): Independent of pointer compression, 8-byte size
+    // fields (external pointers, doubles and BigInt data) are not always 8-byte
+    // aligned. This is relying on undefined behaviour in C++, since {data_ptr}
+    // is not aligned to {alignof(ElementType)}.
+    if (!is_shared) {
+      base::WriteUnalignedValue(reinterpret_cast<Address>(data_ptr), value);
+      return;
+    }
 
-  static void SetImpl(ElementType* data_ptr, size_t entry, ElementType value) {
     // The JavaScript memory model allows for racy reads and writes to a
-    // SharedArrayBuffer's backing store. ThreadSanitizer will catch these
-    // racy accesses and warn about them, so we disable TSAN for these reads
-    // and writes using annotations.
-    //
-    // We don't use relaxed atomics here, as it is not a requirement of the
-    // JavaScript memory model to have tear-free reads of overlapping accesses,
-    // and using relaxed atomics may introduce overhead.
-    TSAN_ANNOTATE_IGNORE_WRITES_BEGIN;
-    if (COMPRESS_POINTERS_BOOL && alignof(ElementType) > kTaggedSize) {
-      // TODO(ishell, v8:8875): When pointer compression is enabled 8-byte size
-      // fields (external pointers, doubles and BigInt data) are only
-      // kTaggedSize aligned so we have to use unaligned pointer friendly way of
-      // accessing them in order to avoid undefined behavior in C++ code.
-      base::WriteUnalignedValue<ElementType>(
-          reinterpret_cast<Address>(data_ptr + entry), value);
-    } else {
-      data_ptr[entry] = value;
+    // SharedArrayBuffer's backing store. Using relaxed atomics is not strictly
+    // required for JavaScript, but will avoid undefined behaviour in C++ and is
+    // unlikely to introduce noticable overhead.
+    if (IsAligned(reinterpret_cast<uintptr_t>(data_ptr),
+                  alignof(std::atomic<ElementType>))) {
+      // Use a single relaxed atomic store.
+      STATIC_ASSERT(sizeof(std::atomic<ElementType>) == sizeof(ElementType));
+      reinterpret_cast<std::atomic<ElementType>*>(data_ptr)->store(
+          value, std::memory_order_relaxed);
+      return;
+    }
+
+    // Some static CHECKs (are optimized out if succeeding) to ensure that
+    // {data_ptr} is at least four byte aligned, and {std::atomic<uint32_t>}
+    // has size and alignment of four bytes, such that we can cast the
+    // {data_ptr} to it.
+    CHECK_LE(kInt32Size, alignof(ElementType));
+    CHECK_EQ(kInt32Size, alignof(std::atomic<uint32_t>));
+    CHECK_EQ(kInt32Size, sizeof(std::atomic<uint32_t>));
+    // And dynamically check that we indeed have at least four byte alignment.
+    DCHECK(IsAligned(reinterpret_cast<uintptr_t>(data_ptr), kInt32Size));
+    // Store as multiple 32-bit words. Make {kNumWords} >= 1 to avoid compiler
+    // warnings for the empty array or memcpy to an empty object.
+    constexpr size_t kNumWords =
+        std::max(size_t{1}, sizeof(ElementType) / kInt32Size);
+    uint32_t words[kNumWords];
+    CHECK_EQ(sizeof(words), sizeof(value));
+    memcpy(words, &value, sizeof(value));
+    for (size_t word = 0; word < kNumWords; ++word) {
+      STATIC_ASSERT(sizeof(std::atomic<uint32_t>) == sizeof(uint32_t));
+      reinterpret_cast<std::atomic<uint32_t>*>(data_ptr)[word].store(
+          words[word], std::memory_order_relaxed);
     }
-    TSAN_ANNOTATE_IGNORE_WRITES_END;
   }
 
   static Handle<Object> GetInternalImpl(Handle<JSObject> holder,
                                         InternalIndex entry) {
     Handle<JSTypedArray> typed_array = Handle<JSTypedArray>::cast(holder);
     Isolate* isolate = typed_array->GetIsolate();
-    DCHECK_LE(entry.raw_value(), typed_array->length());
+    DCHECK_LT(entry.raw_value(), typed_array->GetLength());
     DCHECK(!typed_array->WasDetached());
-    ElementType elem = GetImpl(
-        static_cast<ElementType*>(typed_array->DataPtr()), entry.raw_value());
+    auto* element_ptr =
+        static_cast<ElementType*>(typed_array->DataPtr()) + entry.raw_value();
+    auto is_shared = typed_array->buffer().is_shared() ? kShared : kUnshared;
+    ElementType elem = GetImpl(element_ptr, is_shared);
     return ToHandle(isolate, elem);
   }
 
@@ -3042,28 +3150,53 @@ class TypedElementsAccessor
     UNREACHABLE();
   }
 
-  static ElementType GetImpl(ElementType* data_ptr, size_t entry) {
+  static ElementType GetImpl(ElementType* data_ptr, IsSharedBuffer is_shared) {
+    // TODO(ishell, v8:8875): Independent of pointer compression, 8-byte size
+    // fields (external pointers, doubles and BigInt data) are not always
+    // 8-byte aligned.
+    if (!is_shared) {
+      return base::ReadUnalignedValue<ElementType>(
+          reinterpret_cast<Address>(data_ptr));
+    }
+
     // The JavaScript memory model allows for racy reads and writes to a
-    // SharedArrayBuffer's backing store. ThreadSanitizer will catch these
-    // racy accesses and warn about them, so we disable TSAN for these reads
-    // and writes using annotations.
-    //
-    // We don't use relaxed atomics here, as it is not a requirement of the
-    // JavaScript memory model to have tear-free reads of overlapping accesses,
-    // and using relaxed atomics may introduce overhead.
-    TSAN_ANNOTATE_IGNORE_READS_BEGIN;
-    ElementType result;
-    if (COMPRESS_POINTERS_BOOL && alignof(ElementType) > kTaggedSize) {
-      // TODO(ishell, v8:8875): When pointer compression is enabled 8-byte size
-      // fields (external pointers, doubles and BigInt data) are only
-      // kTaggedSize aligned so we have to use unaligned pointer friendly way of
-      // accessing them in order to avoid undefined behavior in C++ code.
-      result = base::ReadUnalignedValue<ElementType>(
-          reinterpret_cast<Address>(data_ptr + entry));
-    } else {
-      result = data_ptr[entry];
+    // SharedArrayBuffer's backing store. Using relaxed atomics is not strictly
+    // required for JavaScript, but will avoid undefined behaviour in C++ and is
+    // unlikely to introduce noticable overhead.
+    if (IsAligned(reinterpret_cast<uintptr_t>(data_ptr),
+                  alignof(std::atomic<ElementType>))) {
+      // Use a single relaxed atomic load.
+      STATIC_ASSERT(sizeof(std::atomic<ElementType>) == sizeof(ElementType));
+      // Note: acquire semantics are not needed here, but clang seems to merge
+      // this atomic load with the non-atomic load above if we use relaxed
+      // semantics. This will result in TSan failures.
+      return reinterpret_cast<std::atomic<ElementType>*>(data_ptr)->load(
+          std::memory_order_acquire);
+    }
+
+    // Some static CHECKs (are optimized out if succeeding) to ensure that
+    // {data_ptr} is at least four byte aligned, and {std::atomic<uint32_t>}
+    // has size and alignment of four bytes, such that we can cast the
+    // {data_ptr} to it.
+    CHECK_LE(kInt32Size, alignof(ElementType));
+    CHECK_EQ(kInt32Size, alignof(std::atomic<uint32_t>));
+    CHECK_EQ(kInt32Size, sizeof(std::atomic<uint32_t>));
+    // And dynamically check that we indeed have at least four byte alignment.
+    DCHECK(IsAligned(reinterpret_cast<uintptr_t>(data_ptr), kInt32Size));
+    // Load in multiple 32-bit words. Make {kNumWords} >= 1 to avoid compiler
+    // warnings for the empty array or memcpy to an empty object.
+    constexpr size_t kNumWords =
+        std::max(size_t{1}, sizeof(ElementType) / kInt32Size);
+    uint32_t words[kNumWords];
+    for (size_t word = 0; word < kNumWords; ++word) {
+      STATIC_ASSERT(sizeof(std::atomic<uint32_t>) == sizeof(uint32_t));
+      words[word] =
+          reinterpret_cast<std::atomic<uint32_t>*>(data_ptr)[word].load(
+              std::memory_order_relaxed);
     }
-    TSAN_ANNOTATE_IGNORE_READS_END;
+    ElementType result;
+    CHECK_EQ(sizeof(words), sizeof(result));
+    memcpy(&result, words, sizeof(result));
     return result;
   }
 
@@ -3086,9 +3219,9 @@ class TypedElementsAccessor
     return false;
   }
 
-  static void SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
-                            uint32_t length,
-                            Handle<FixedArrayBase> backing_store) {
+  static Maybe<bool> SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
+                                   uint32_t length,
+                                   Handle<FixedArrayBase> backing_store) {
     // External arrays do not support changing their length.
     UNREACHABLE();
   }
@@ -3111,8 +3244,7 @@ class TypedElementsAccessor
 
   static size_t GetCapacityImpl(JSObject holder, FixedArrayBase backing_store) {
     JSTypedArray typed_array = JSTypedArray::cast(holder);
-    if (typed_array.WasDetached()) return 0;
-    return typed_array.length();
+    return typed_array.GetLength();
   }
 
   static size_t NumberOfElementsImpl(JSObject receiver,
@@ -3155,8 +3287,9 @@ class TypedElementsAccessor
     return Just(true);
   }
 
-  static Object FillImpl(Handle<JSObject> receiver, Handle<Object> value,
-                         size_t start, size_t end) {
+  static MaybeHandle<Object> FillImpl(Handle<JSObject> receiver,
+                                      Handle<Object> value, size_t start,
+                                      size_t end) {
     Handle<JSTypedArray> typed_array = Handle<JSTypedArray>::cast(receiver);
     DCHECK(!typed_array->WasDetached());
     DCHECK_LE(start, end);
@@ -3171,7 +3304,7 @@ class TypedElementsAccessor
     } else {
       std::fill(data + start, data + end, scalar);
     }
-    return *typed_array;
+    return MaybeHandle<Object>(typed_array);
   }
 
   static Maybe<bool> IncludesValueImpl(Isolate* isolate,
@@ -3200,6 +3333,7 @@ class TypedElementsAccessor
     ElementType typed_search_value;
     ElementType* data_ptr =
         reinterpret_cast<ElementType*>(typed_array.DataPtr());
+    auto is_shared = typed_array.buffer().is_shared() ? kShared : kUnshared;
     if (Kind == BIGINT64_ELEMENTS || Kind == BIGUINT64_ELEMENTS) {
       if (!value->IsBigInt()) return Just(false);
       bool lossless;
@@ -3215,8 +3349,8 @@ class TypedElementsAccessor
         }
         if (std::isnan(search_value)) {
           for (size_t k = start_from; k < length; ++k) {
-            double elem_k =
-                static_cast<double>(AccessorClass::GetImpl(data_ptr, k));
+            double elem_k = static_cast<double>(
+                AccessorClass::GetImpl(data_ptr + k, is_shared));
             if (std::isnan(elem_k)) return Just(true);
           }
           return Just(false);
@@ -3233,7 +3367,7 @@ class TypedElementsAccessor
     }
 
     for (size_t k = start_from; k < length; ++k) {
-      ElementType elem_k = AccessorClass::GetImpl(data_ptr, k);
+      ElementType elem_k = AccessorClass::GetImpl(data_ptr + k, is_shared);
       if (elem_k == typed_search_value) return Just(true);
     }
     return Just(false);
@@ -3285,8 +3419,9 @@ class TypedElementsAccessor
       length = typed_array.length();
     }
 
+    auto is_shared = typed_array.buffer().is_shared() ? kShared : kUnshared;
     for (size_t k = start_from; k < length; ++k) {
-      ElementType elem_k = AccessorClass::GetImpl(data_ptr, k);
+      ElementType elem_k = AccessorClass::GetImpl(data_ptr + k, is_shared);
       if (elem_k == typed_search_value) return Just<int64_t>(k);
     }
     return Just<int64_t>(-1);
@@ -3333,8 +3468,9 @@ class TypedElementsAccessor
 
     DCHECK_LT(start_from, typed_array.length());
     size_t k = start_from;
+    auto is_shared = typed_array.buffer().is_shared() ? kShared : kUnshared;
     do {
-      ElementType elem_k = AccessorClass::GetImpl(data_ptr, k);
+      ElementType elem_k = AccessorClass::GetImpl(data_ptr + k, is_shared);
       if (elem_k == typed_search_value) return Just<int64_t>(k);
     } while (k-- != 0);
     return Just<int64_t>(-1);
@@ -3384,12 +3520,16 @@ class TypedElementsAccessor
     size_t count = end - start;
     DCHECK_LE(count, destination.length());
     ElementType* dest_data = static_cast<ElementType*>(destination.DataPtr());
+    auto is_shared =
+        source.buffer().is_shared() || destination.buffer().is_shared()
+            ? kShared
+            : kUnshared;
     switch (source.GetElementsKind()) {
 #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype)                            \
   case TYPE##_ELEMENTS: {                                                    \
     ctype* source_data = reinterpret_cast<ctype*>(source.DataPtr()) + start; \
     CopyBetweenBackingStores<TYPE##_ELEMENTS, ctype>(source_data, dest_data, \
-                                                     count);                 \
+                                                     count, is_shared);      \
     break;                                                                   \
   }
       TYPED_ARRAYS(TYPED_ARRAY_CASE)
@@ -3408,16 +3548,16 @@ class TypedElementsAccessor
   template <ElementsKind SourceKind, typename SourceElementType>
   static void CopyBetweenBackingStores(SourceElementType* source_data_ptr,
                                        ElementType* dest_data_ptr,
-                                       size_t length) {
-    DisallowGarbageCollection no_gc;
-    for (size_t i = 0; i < length; i++) {
+                                       size_t length,
+                                       IsSharedBuffer is_shared) {
+    for (; length > 0; --length, ++source_data_ptr, ++dest_data_ptr) {
       // We use scalar accessors to avoid boxing/unboxing, so there are no
       // allocations.
       SourceElementType source_elem =
           TypedElementsAccessor<SourceKind, SourceElementType>::GetImpl(
-              source_data_ptr, i);
+              source_data_ptr, is_shared);
       ElementType dest_elem = FromScalar(source_elem);
-      SetImpl(dest_data_ptr, i, dest_elem);
+      SetImpl(dest_data_ptr, dest_elem, is_shared);
     }
   }
 
@@ -3448,14 +3588,24 @@ class TypedElementsAccessor
     size_t source_byte_length = source.byte_length();
     size_t dest_byte_length = destination.byte_length();
 
+    bool source_shared = source.buffer().is_shared();
+    bool destination_shared = destination.buffer().is_shared();
+
     // We can simply copy the backing store if the types are the same, or if
     // we are converting e.g. Uint8 <-> Int8, as the binary representation
     // will be the same. This is not the case for floats or clamped Uint8,
     // which have special conversion operations.
     if (same_type || (same_size && both_are_simple)) {
       size_t element_size = source.element_size();
-      std::memmove(dest_data + offset * element_size, source_data,
-                   length * element_size);
+      if (source_shared || destination_shared) {
+        base::Relaxed_Memcpy(
+            reinterpret_cast<base::Atomic8*>(dest_data + offset * element_size),
+            reinterpret_cast<base::Atomic8*>(source_data),
+            length * element_size);
+      } else {
+        std::memmove(dest_data + offset * element_size, source_data,
+                     length * element_size);
+      }
     } else {
       std::unique_ptr<uint8_t[]> cloned_source_elements;
 
@@ -3463,17 +3613,25 @@ class TypedElementsAccessor
       if (dest_data + dest_byte_length > source_data &&
           source_data + source_byte_length > dest_data) {
         cloned_source_elements.reset(new uint8_t[source_byte_length]);
-        std::memcpy(cloned_source_elements.get(), source_data,
-                    source_byte_length);
+        if (source_shared) {
+          base::Relaxed_Memcpy(
+              reinterpret_cast<base::Atomic8*>(cloned_source_elements.get()),
+              reinterpret_cast<base::Atomic8*>(source_data),
+              source_byte_length);
+        } else {
+          std::memcpy(cloned_source_elements.get(), source_data,
+                      source_byte_length);
+        }
         source_data = cloned_source_elements.get();
       }
 
       switch (source.GetElementsKind()) {
-#define TYPED_ARRAY_CASE(Type, type, TYPE, ctype)                    \
-  case TYPE##_ELEMENTS:                                              \
-    CopyBetweenBackingStores<TYPE##_ELEMENTS, ctype>(                \
-        reinterpret_cast<ctype*>(source_data),                       \
-        reinterpret_cast<ElementType*>(dest_data) + offset, length); \
+#define TYPED_ARRAY_CASE(Type, type, TYPE, ctype)                   \
+  case TYPE##_ELEMENTS:                                             \
+    CopyBetweenBackingStores<TYPE##_ELEMENTS, ctype>(               \
+        reinterpret_cast<ctype*>(source_data),                      \
+        reinterpret_cast<ElementType*>(dest_data) + offset, length, \
+        source_shared || destination_shared ? kShared : kUnshared); \
     break;
         TYPED_ARRAYS(TYPED_ARRAY_CASE)
         default:
@@ -3529,6 +3687,9 @@ class TypedElementsAccessor
 
     ElementsKind kind = source.GetElementsKind();
 
+    auto destination_shared =
+        destination.buffer().is_shared() ? kShared : kUnshared;
+
     // When we find the hole, we normally have to look up the element on the
     // prototype chain, which is not handled here and we return false instead.
     // When the array has the original array prototype, and that prototype has
@@ -3546,17 +3707,19 @@ class TypedElementsAccessor
 
       for (size_t i = 0; i < length; i++) {
         Object elem = source_store.get(static_cast<int>(i));
-        SetImpl(dest_data, i, FromScalar(Smi::ToInt(elem)));
+        SetImpl(dest_data + i, FromScalar(Smi::ToInt(elem)),
+                destination_shared);
       }
       return true;
     } else if (kind == HOLEY_SMI_ELEMENTS) {
       FixedArray source_store = FixedArray::cast(source.elements());
       for (size_t i = 0; i < length; i++) {
         if (source_store.is_the_hole(isolate, static_cast<int>(i))) {
-          SetImpl(dest_data, i, FromObject(undefined));
+          SetImpl(dest_data + i, FromObject(undefined), destination_shared);
         } else {
           Object elem = source_store.get(static_cast<int>(i));
-          SetImpl(dest_data, i, FromScalar(Smi::ToInt(elem)));
+          SetImpl(dest_data + i, FromScalar(Smi::ToInt(elem)),
+                  destination_shared);
         }
       }
       return true;
@@ -3569,17 +3732,17 @@ class TypedElementsAccessor
         // Use the from_double conversion for this specific TypedArray type,
         // rather than relying on C++ to convert elem.
         double elem = source_store.get_scalar(static_cast<int>(i));
-        SetImpl(dest_data, i, FromScalar(elem));
+        SetImpl(dest_data + i, FromScalar(elem), destination_shared);
       }
       return true;
     } else if (kind == HOLEY_DOUBLE_ELEMENTS) {
       FixedDoubleArray source_store = FixedDoubleArray::cast(source.elements());
       for (size_t i = 0; i < length; i++) {
         if (source_store.is_the_hole(static_cast<int>(i))) {
-          SetImpl(dest_data, i, FromObject(undefined));
+          SetImpl(dest_data + i, FromObject(undefined), destination_shared);
         } else {
           double elem = source_store.get_scalar(static_cast<int>(i));
-          SetImpl(dest_data, i, FromScalar(elem));
+          SetImpl(dest_data + i, FromScalar(elem), destination_shared);
         }
       }
       return true;
@@ -3872,9 +4035,225 @@ Handle<Object> TypedElementsAccessor<BIGUINT64_ELEMENTS, uint64_t>::ToHandle(
   return BigInt::FromUint64(isolate, value);
 }
 
+// static
+template <>
+Handle<Object> TypedElementsAccessor<RAB_GSAB_INT8_ELEMENTS, int8_t>::ToHandle(
+    Isolate* isolate, int8_t value) {
+  return handle(Smi::FromInt(value), isolate);
+}
+
+// static
+template <>
+Handle<Object> TypedElementsAccessor<RAB_GSAB_UINT8_ELEMENTS,
+                                     uint8_t>::ToHandle(Isolate* isolate,
+                                                        uint8_t value) {
+  return handle(Smi::FromInt(value), isolate);
+}
+
+// static
+template <>
+Handle<Object> TypedElementsAccessor<RAB_GSAB_INT16_ELEMENTS,
+                                     int16_t>::ToHandle(Isolate* isolate,
+                                                        int16_t value) {
+  return handle(Smi::FromInt(value), isolate);
+}
+
+// static
+template <>
+Handle<Object> TypedElementsAccessor<RAB_GSAB_UINT16_ELEMENTS,
+                                     uint16_t>::ToHandle(Isolate* isolate,
+                                                         uint16_t value) {
+  return handle(Smi::FromInt(value), isolate);
+}
+
+// static
+template <>
+Handle<Object> TypedElementsAccessor<RAB_GSAB_INT32_ELEMENTS,
+                                     int32_t>::ToHandle(Isolate* isolate,
+                                                        int32_t value) {
+  return isolate->factory()->NewNumberFromInt(value);
+}
+
+// static
+template <>
+Handle<Object> TypedElementsAccessor<RAB_GSAB_UINT32_ELEMENTS,
+                                     uint32_t>::ToHandle(Isolate* isolate,
+                                                         uint32_t value) {
+  return isolate->factory()->NewNumberFromUint(value);
+}
+
+// static
+template <>
+float TypedElementsAccessor<RAB_GSAB_FLOAT32_ELEMENTS, float>::FromScalar(
+    double value) {
+  return DoubleToFloat32(value);
+}
+
+// static
+template <>
+Handle<Object> TypedElementsAccessor<RAB_GSAB_FLOAT32_ELEMENTS,
+                                     float>::ToHandle(Isolate* isolate,
+                                                      float value) {
+  return isolate->factory()->NewNumber(value);
+}
+
+// static
+template <>
+double TypedElementsAccessor<RAB_GSAB_FLOAT64_ELEMENTS, double>::FromScalar(
+    double value) {
+  return value;
+}
+
+// static
+template <>
+Handle<Object> TypedElementsAccessor<RAB_GSAB_FLOAT64_ELEMENTS,
+                                     double>::ToHandle(Isolate* isolate,
+                                                       double value) {
+  return isolate->factory()->NewNumber(value);
+}
+
+// static
+template <>
+uint8_t TypedElementsAccessor<RAB_GSAB_UINT8_CLAMPED_ELEMENTS,
+                              uint8_t>::FromScalar(int value) {
+  if (value < 0x00) return 0x00;
+  if (value > 0xFF) return 0xFF;
+  return static_cast<uint8_t>(value);
+}
+
+// static
+template <>
+uint8_t TypedElementsAccessor<RAB_GSAB_UINT8_CLAMPED_ELEMENTS,
+                              uint8_t>::FromScalar(uint32_t value) {
+  // We need this special case for Uint32 -> Uint8Clamped, because the highest
+  // Uint32 values will be negative as an int, clamping to 0, rather than 255.
+  if (value > 0xFF) return 0xFF;
+  return static_cast<uint8_t>(value);
+}
+
+// static
+template <>
+uint8_t TypedElementsAccessor<RAB_GSAB_UINT8_CLAMPED_ELEMENTS,
+                              uint8_t>::FromScalar(double value) {
+  // Handle NaNs and less than zero values which clamp to zero.
+  if (!(value > 0)) return 0;
+  if (value > 0xFF) return 0xFF;
+  return static_cast<uint8_t>(lrint(value));
+}
+
+// static
+template <>
+Handle<Object> TypedElementsAccessor<RAB_GSAB_UINT8_CLAMPED_ELEMENTS,
+                                     uint8_t>::ToHandle(Isolate* isolate,
+                                                        uint8_t value) {
+  return handle(Smi::FromInt(value), isolate);
+}
+
+// static
+template <>
+int64_t TypedElementsAccessor<RAB_GSAB_BIGINT64_ELEMENTS, int64_t>::FromScalar(
+    int value) {
+  UNREACHABLE();
+}
+
+// static
+template <>
+int64_t TypedElementsAccessor<RAB_GSAB_BIGINT64_ELEMENTS, int64_t>::FromScalar(
+    uint32_t value) {
+  UNREACHABLE();
+}
+
+// static
+template <>
+int64_t TypedElementsAccessor<RAB_GSAB_BIGINT64_ELEMENTS, int64_t>::FromScalar(
+    double value) {
+  UNREACHABLE();
+}
+
+// static
+template <>
+int64_t TypedElementsAccessor<RAB_GSAB_BIGINT64_ELEMENTS, int64_t>::FromScalar(
+    int64_t value) {
+  return value;
+}
+
+// static
+template <>
+int64_t TypedElementsAccessor<RAB_GSAB_BIGINT64_ELEMENTS, int64_t>::FromScalar(
+    uint64_t value) {
+  return static_cast<int64_t>(value);
+}
+
+// static
+template <>
+int64_t TypedElementsAccessor<RAB_GSAB_BIGINT64_ELEMENTS, int64_t>::FromObject(
+    Object value, bool* lossless) {
+  return BigInt::cast(value).AsInt64(lossless);
+}
+
+// static
+template <>
+Handle<Object> TypedElementsAccessor<RAB_GSAB_BIGINT64_ELEMENTS,
+                                     int64_t>::ToHandle(Isolate* isolate,
+                                                        int64_t value) {
+  return BigInt::FromInt64(isolate, value);
+}
+
+// static
+template <>
+uint64_t TypedElementsAccessor<RAB_GSAB_BIGUINT64_ELEMENTS,
+                               uint64_t>::FromScalar(int value) {
+  UNREACHABLE();
+}
+
+// static
+template <>
+uint64_t TypedElementsAccessor<RAB_GSAB_BIGUINT64_ELEMENTS,
+                               uint64_t>::FromScalar(uint32_t value) {
+  UNREACHABLE();
+}
+
+// static
+template <>
+uint64_t TypedElementsAccessor<RAB_GSAB_BIGUINT64_ELEMENTS,
+                               uint64_t>::FromScalar(double value) {
+  UNREACHABLE();
+}
+
+// static
+template <>
+uint64_t TypedElementsAccessor<RAB_GSAB_BIGUINT64_ELEMENTS,
+                               uint64_t>::FromScalar(int64_t value) {
+  return static_cast<uint64_t>(value);
+}
+
+// static
+template <>
+uint64_t TypedElementsAccessor<RAB_GSAB_BIGUINT64_ELEMENTS,
+                               uint64_t>::FromScalar(uint64_t value) {
+  return value;
+}
+
+// static
+template <>
+uint64_t TypedElementsAccessor<RAB_GSAB_BIGUINT64_ELEMENTS,
+                               uint64_t>::FromObject(Object value,
+                                                     bool* lossless) {
+  return BigInt::cast(value).AsUint64(lossless);
+}
+
+// static
+template <>
+Handle<Object> TypedElementsAccessor<RAB_GSAB_BIGUINT64_ELEMENTS,
+                                     uint64_t>::ToHandle(Isolate* isolate,
+                                                         uint64_t value) {
+  return BigInt::FromUint64(isolate, value);
+}
+
 #define FIXED_ELEMENTS_ACCESSOR(Type, type, TYPE, ctype) \
   using Type##ElementsAccessor = TypedElementsAccessor<TYPE##_ELEMENTS, ctype>;
 TYPED_ARRAYS(FIXED_ELEMENTS_ACCESSOR)
+RAB_GSAB_TYPED_ARRAYS(FIXED_ELEMENTS_ACCESSOR)
 #undef FIXED_ELEMENTS_ACCESSOR
 
 template <typename Subclass, typename ArgumentsAccessor, typename KindTraits>
@@ -3894,7 +4273,7 @@ class SloppyArgumentsElementsAccessor
     if (entry.as_uint32() < length) {
       // Read context mapped entry.
       DisallowGarbageCollection no_gc;
-      Object probe = elements->mapped_entries(entry.as_uint32());
+      Object probe = elements->mapped_entries(entry.as_uint32(), kRelaxedLoad);
       DCHECK(!probe.IsTheHole(isolate));
       Context context = elements->context();
       int context_entry = Smi::ToInt(probe);
@@ -3908,13 +4287,13 @@ class SloppyArgumentsElementsAccessor
     }
   }
 
-  static void TransitionElementsKindImpl(Handle<JSObject> object,
-                                         Handle<Map> map) {
+  static Maybe<bool> TransitionElementsKindImpl(Handle<JSObject> object,
+                                                Handle<Map> map) {
     UNREACHABLE();
   }
 
-  static void GrowCapacityAndConvertImpl(Handle<JSObject> object,
-                                         uint32_t capacity) {
+  static Maybe<bool> GrowCapacityAndConvertImpl(Handle<JSObject> object,
+                                                uint32_t capacity) {
     UNREACHABLE();
   }
 
@@ -3930,7 +4309,7 @@ class SloppyArgumentsElementsAccessor
     if (entry.as_uint32() < length) {
       // Store context mapped entry.
       DisallowGarbageCollection no_gc;
-      Object probe = elements.mapped_entries(entry.as_uint32());
+      Object probe = elements.mapped_entries(entry.as_uint32(), kRelaxedLoad);
       DCHECK(!probe.IsTheHole());
       Context context = Context::cast(elements.context());
       int context_entry = Smi::ToInt(probe);
@@ -3953,9 +4332,9 @@ class SloppyArgumentsElementsAccessor
     }
   }
 
-  static void SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
-                            uint32_t length,
-                            Handle<FixedArrayBase> parameter_map) {
+  static Maybe<bool> SetLengthImpl(Isolate* isolate, Handle<JSArray> array,
+                                   uint32_t length,
+                                   Handle<FixedArrayBase> parameter_map) {
     // Sloppy arguments objects are not arrays.
     UNREACHABLE();
   }
@@ -4063,7 +4442,7 @@ class SloppyArgumentsElementsAccessor
                                  size_t index) {
     uint32_t length = elements.length();
     if (index >= length) return false;
-    return !elements.mapped_entries(static_cast<uint32_t>(index))
+    return !elements.mapped_entries(static_cast<uint32_t>(index), kRelaxedLoad)
                 .IsTheHole(isolate);
   }
 
@@ -4118,7 +4497,8 @@ class SloppyArgumentsElementsAccessor
     uint32_t length = elements->length();
 
     for (uint32_t i = 0; i < length; ++i) {
-      if (elements->mapped_entries(i).IsTheHole(isolate)) continue;
+      if (elements->mapped_entries(i, kRelaxedLoad).IsTheHole(isolate))
+        continue;
       if (convert == GetKeysConversion::kConvertToString) {
         Handle<String> index_string = isolate->factory()->Uint32ToString(i);
         list->set(insertion_index, *index_string);
@@ -4251,9 +4631,10 @@ class SlowSloppyArgumentsElementsAccessor
         NumberDictionary::DeleteEntry(isolate, dict, entry.adjust_down(length));
     elements->set_arguments(*dict);
   }
-  static void AddImpl(Handle<JSObject> object, uint32_t index,
-                      Handle<Object> value, PropertyAttributes attributes,
-                      uint32_t new_capacity) {
+  static Maybe<bool> AddImpl(Handle<JSObject> object, uint32_t index,
+                             Handle<Object> value,
+                             PropertyAttributes attributes,
+                             uint32_t new_capacity) {
     Isolate* isolate = object->GetIsolate();
     Handle<SloppyArgumentsElements> elements(
         SloppyArgumentsElements::cast(object->elements()), isolate);
@@ -4270,6 +4651,7 @@ class SlowSloppyArgumentsElementsAccessor
     if (*dictionary != *new_dictionary) {
       elements->set_arguments(*new_dictionary);
     }
+    return Just(true);
   }
 
   static void ReconfigureImpl(Handle<JSObject> object,
@@ -4281,7 +4663,7 @@ class SlowSloppyArgumentsElementsAccessor
         Handle<SloppyArgumentsElements>::cast(store);
     uint32_t length = elements->length();
     if (entry.as_uint32() < length) {
-      Object probe = elements->mapped_entries(entry.as_uint32());
+      Object probe = elements->mapped_entries(entry.as_uint32(), kRelaxedLoad);
       DCHECK(!probe.IsTheHole(isolate));
       Context context = elements->context();
       int context_entry = Smi::ToInt(probe);
@@ -4365,9 +4747,10 @@ class FastSloppyArgumentsElementsAccessor
     SlowSloppyArgumentsElementsAccessor::SloppyDeleteImpl(obj, elements, entry);
   }
 
-  static void AddImpl(Handle<JSObject> object, uint32_t index,
-                      Handle<Object> value, PropertyAttributes attributes,
-                      uint32_t new_capacity) {
+  static Maybe<bool> AddImpl(Handle<JSObject> object, uint32_t index,
+                             Handle<Object> value,
+                             PropertyAttributes attributes,
+                             uint32_t new_capacity) {
     DCHECK_EQ(NONE, attributes);
     Isolate* isolate = object->GetIsolate();
     Handle<SloppyArgumentsElements> elements(
@@ -4375,7 +4758,8 @@ class FastSloppyArgumentsElementsAccessor
     Handle<FixedArray> old_arguments(elements->arguments(), isolate);
     if (old_arguments->IsNumberDictionary() ||
         static_cast<uint32_t>(old_arguments->length()) < new_capacity) {
-      GrowCapacityAndConvertImpl(object, new_capacity);
+      MAYBE_RETURN(GrowCapacityAndConvertImpl(object, new_capacity),
+                   Nothing<bool>());
     }
     FixedArray arguments = elements->arguments();
     // For fast holey objects, the entry equals the index. The code above made
@@ -4385,6 +4769,7 @@ class FastSloppyArgumentsElementsAccessor
     // kMaxUInt32.
     FastHoleyObjectElementsAccessor::SetImpl(arguments, InternalIndex(index),
                                              *value);
+    return Just(true);
   }
 
   static void ReconfigureImpl(Handle<JSObject> object,
@@ -4414,8 +4799,8 @@ class FastSloppyArgumentsElementsAccessor
     }
   }
 
-  static void GrowCapacityAndConvertImpl(Handle<JSObject> object,
-                                         uint32_t capacity) {
+  static Maybe<bool> GrowCapacityAndConvertImpl(Handle<JSObject> object,
+                                                uint32_t capacity) {
     Isolate* isolate = object->GetIsolate();
     Handle<SloppyArgumentsElements> elements(
         SloppyArgumentsElements::cast(object->elements()), isolate);
@@ -4426,13 +4811,17 @@ class FastSloppyArgumentsElementsAccessor
     // elements.
     DCHECK(from_kind == SLOW_SLOPPY_ARGUMENTS_ELEMENTS ||
            static_cast<uint32_t>(old_arguments->length()) < capacity);
-    Handle<FixedArrayBase> arguments =
-        ConvertElementsWithCapacity(object, old_arguments, from_kind, capacity);
+    Handle<FixedArrayBase> arguments;
+    ASSIGN_RETURN_ON_EXCEPTION_VALUE(
+        isolate, arguments,
+        ConvertElementsWithCapacity(object, old_arguments, from_kind, capacity),
+        Nothing<bool>());
     Handle<Map> new_map = JSObject::GetElementsTransitionMap(
         object, FAST_SLOPPY_ARGUMENTS_ELEMENTS);
     JSObject::MigrateToMap(isolate, object, new_map);
     elements->set_arguments(FixedArray::cast(*arguments));
     JSObject::ValidateElements(*object);
+    return Just(true);
   }
 };
 
@@ -4504,9 +4893,10 @@ class StringWrapperElementsAccessor
                                   value);
   }
 
-  static void AddImpl(Handle<JSObject> object, uint32_t index,
-                      Handle<Object> value, PropertyAttributes attributes,
-                      uint32_t new_capacity) {
+  static Maybe<bool> AddImpl(Handle<JSObject> object, uint32_t index,
+                             Handle<Object> value,
+                             PropertyAttributes attributes,
+                             uint32_t new_capacity) {
     DCHECK(index >= static_cast<uint32_t>(GetString(*object).length()));
     // Explicitly grow fast backing stores if needed. Dictionaries know how to
     // extend their capacity themselves.
@@ -4514,10 +4904,12 @@ class StringWrapperElementsAccessor
         (object->GetElementsKind() == SLOW_STRING_WRAPPER_ELEMENTS ||
          BackingStoreAccessor::GetCapacityImpl(*object, object->elements()) !=
              new_capacity)) {
-      GrowCapacityAndConvertImpl(object, new_capacity);
+      MAYBE_RETURN(GrowCapacityAndConvertImpl(object, new_capacity),
+                   Nothing<bool>());
     }
     BackingStoreAccessor::AddImpl(object, index, value, attributes,
                                   new_capacity);
+    return Just(true);
   }
 
   static void ReconfigureImpl(Handle<JSObject> object,
@@ -4562,8 +4954,8 @@ class StringWrapperElementsAccessor
                                                            backing_store, keys);
   }
 
-  static void GrowCapacityAndConvertImpl(Handle<JSObject> object,
-                                         uint32_t capacity) {
+  static Maybe<bool> GrowCapacityAndConvertImpl(Handle<JSObject> object,
+                                                uint32_t capacity) {
     Handle<FixedArrayBase> old_elements(object->elements(),
                                         object->GetIsolate());
     ElementsKind from_kind = object->GetElementsKind();
@@ -4578,9 +4970,9 @@ class StringWrapperElementsAccessor
     // elements.
     DCHECK(from_kind == SLOW_STRING_WRAPPER_ELEMENTS ||
            static_cast<uint32_t>(old_elements->length()) < capacity);
-    Subclass::BasicGrowCapacityAndConvertImpl(object, old_elements, from_kind,
-                                              FAST_STRING_WRAPPER_ELEMENTS,
-                                              capacity);
+    return Subclass::BasicGrowCapacityAndConvertImpl(
+        object, old_elements, from_kind, FAST_STRING_WRAPPER_ELEMENTS,
+        capacity);
   }
 
   static void CopyElementsImpl(Isolate* isolate, FixedArrayBase from,
@@ -4665,7 +5057,7 @@ MaybeHandle<Object> ArrayConstructInitializeElements(
     } else {
       // Take the argument as the length.
       JSArray::Initialize(array, 0);
-      JSArray::SetLength(array, length);
+      MAYBE_RETURN_NULL(JSArray::SetLength(array, length));
     }
     return array;
   }
diff --git a/chromium/v8/src/objects/elements.h b/chromium/v8/src/objects/elements.h
index 4a34e866f2f..23dbe1d34f1 100644
--- a/chromium/v8/src/objects/elements.h
+++ b/chromium/v8/src/objects/elements.h
@@ -66,7 +66,8 @@ class ElementsAccessor {
   // changing array sizes as defined in EcmaScript 5.1 15.4.5.2, i.e. array that
   // have non-deletable elements can only be shrunk to the size of highest
   // element that is non-deletable.
-  virtual void SetLength(Handle<JSArray> holder, uint32_t new_length) = 0;
+  V8_WARN_UNUSED_RESULT virtual Maybe<bool> SetLength(Handle<JSArray> holder,
+                                                      uint32_t new_length) = 0;
 
   // Copy all indices that have elements from |object| into the given
   // KeyAccumulator. For Dictionary-based element-kinds we filter out elements
@@ -96,13 +97,14 @@ class ElementsAccessor {
       Handle<JSObject> receiver, KeyAccumulator* accumulator,
       AddKeyConversion convert) = 0;
 
-  virtual void TransitionElementsKind(Handle<JSObject> object,
-                                      Handle<Map> map) = 0;
-  virtual void GrowCapacityAndConvert(Handle<JSObject> object,
-                                      uint32_t capacity) = 0;
+  V8_WARN_UNUSED_RESULT virtual Maybe<bool> TransitionElementsKind(
+      Handle<JSObject> object, Handle<Map> map) = 0;
+  V8_WARN_UNUSED_RESULT virtual Maybe<bool> GrowCapacityAndConvert(
+      Handle<JSObject> object, uint32_t capacity) = 0;
   // Unlike GrowCapacityAndConvert do not attempt to convert the backing store
   // and simply return false in this case.
-  virtual bool GrowCapacity(Handle<JSObject> object, uint32_t index) = 0;
+  V8_WARN_UNUSED_RESULT virtual Maybe<bool> GrowCapacity(
+      Handle<JSObject> object, uint32_t index) = 0;
 
   static void InitializeOncePerProcess();
   static void TearDown();
@@ -110,29 +112,36 @@ class ElementsAccessor {
   virtual void Set(Handle<JSObject> holder, InternalIndex entry,
                    Object value) = 0;
 
-  virtual void Add(Handle<JSObject> object, uint32_t index,
-                   Handle<Object> value, PropertyAttributes attributes,
-                   uint32_t new_capacity) = 0;
+  V8_WARN_UNUSED_RESULT virtual Maybe<bool> Add(Handle<JSObject> object,
+                                                uint32_t index,
+                                                Handle<Object> value,
+                                                PropertyAttributes attributes,
+                                                uint32_t new_capacity) = 0;
 
   static Handle<JSArray> Concat(Isolate* isolate, BuiltinArguments* args,
                                 uint32_t concat_size, uint32_t result_length);
 
-  virtual uint32_t Push(Handle<JSArray> receiver, BuiltinArguments* args,
-                        uint32_t push_size) = 0;
+  V8_WARN_UNUSED_RESULT virtual Maybe<uint32_t> Push(Handle<JSArray> receiver,
+                                                     BuiltinArguments* args,
+                                                     uint32_t push_size) = 0;
 
-  virtual uint32_t Unshift(Handle<JSArray> receiver, BuiltinArguments* args,
-                           uint32_t unshift_size) = 0;
+  V8_WARN_UNUSED_RESULT virtual Maybe<uint32_t> Unshift(
+      Handle<JSArray> receiver, BuiltinArguments* args,
+      uint32_t unshift_size) = 0;
 
-  virtual Handle<Object> Pop(Handle<JSArray> receiver) = 0;
+  V8_WARN_UNUSED_RESULT virtual MaybeHandle<Object> Pop(
+      Handle<JSArray> receiver) = 0;
 
-  virtual Handle<Object> Shift(Handle<JSArray> receiver) = 0;
+  V8_WARN_UNUSED_RESULT virtual MaybeHandle<Object> Shift(
+      Handle<JSArray> receiver) = 0;
 
   virtual Handle<NumberDictionary> Normalize(Handle<JSObject> object) = 0;
 
   virtual size_t GetCapacity(JSObject holder, FixedArrayBase backing_store) = 0;
 
-  virtual Object Fill(Handle<JSObject> receiver, Handle<Object> obj_value,
-                      size_t start, size_t end) = 0;
+  V8_WARN_UNUSED_RESULT virtual MaybeHandle<Object> Fill(
+      Handle<JSObject> receiver, Handle<Object> obj_value, size_t start,
+      size_t end) = 0;
 
   // Check an Object's own elements for an element (using SameValueZero
   // semantics)
diff --git a/chromium/v8/src/objects/embedder-data-slot-inl.h b/chromium/v8/src/objects/embedder-data-slot-inl.h
index 3f8deb39f09..983a0b0ad41 100644
--- a/chromium/v8/src/objects/embedder-data-slot-inl.h
+++ b/chromium/v8/src/objects/embedder-data-slot-inl.h
@@ -81,7 +81,7 @@ void EmbedderDataSlot::store_tagged(JSObject object, int embedder_field_index,
 #endif
 }
 
-bool EmbedderDataSlot::ToAlignedPointer(PtrComprCageBase isolate_root,
+bool EmbedderDataSlot::ToAlignedPointer(Isolate* isolate,
                                         void** out_pointer) const {
   // We don't care about atomicity of access here because embedder slots
   // are accessed this way only from the main thread via API during "mutator"
@@ -89,16 +89,9 @@ bool EmbedderDataSlot::ToAlignedPointer(PtrComprCageBase isolate_root,
   // at the tagged part of the embedder slot but read-only access is ok).
   Address raw_value;
 #ifdef V8_HEAP_SANDBOX
-
-  // TODO(syg): V8_HEAP_SANDBOX doesn't work with pointer cage
-#ifdef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
-#error "V8_HEAP_SANDBOX requires per-Isolate pointer compression cage"
-#endif
-
   uint32_t index = base::Memory<uint32_t>(address() + kRawPayloadOffset);
-  const Isolate* isolate = Isolate::FromRootAddress(isolate_root.address());
-  raw_value = isolate->external_pointer_table().get(index) ^
-              kEmbedderDataSlotPayloadTag;
+  raw_value = isolate->external_pointer_table().get(index) &
+              ~kEmbedderDataSlotPayloadTag;
 #else
   if (COMPRESS_POINTERS_BOOL) {
     // TODO(ishell, v8:8875): When pointer compression is enabled 8-byte size
@@ -114,27 +107,20 @@ bool EmbedderDataSlot::ToAlignedPointer(PtrComprCageBase isolate_root,
   return HAS_SMI_TAG(raw_value);
 }
 
-bool EmbedderDataSlot::ToAlignedPointerSafe(PtrComprCageBase isolate_root,
+bool EmbedderDataSlot::ToAlignedPointerSafe(Isolate* isolate,
                                             void** out_pointer) const {
 #ifdef V8_HEAP_SANDBOX
-
-  // TODO(syg): V8_HEAP_SANDBOX doesn't work with pointer cage
-#ifdef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
-#error "V8_HEAP_SANDBOX requires per-Isolate pointer compression cage"
-#endif
-
   uint32_t index = base::Memory<uint32_t>(address() + kRawPayloadOffset);
   Address raw_value;
-  const Isolate* isolate = Isolate::FromRootAddress(isolate_root.address());
   if (isolate->external_pointer_table().is_valid_index(index)) {
-    raw_value = isolate->external_pointer_table().get(index) ^
-                kEmbedderDataSlotPayloadTag;
+    raw_value = isolate->external_pointer_table().get(index) &
+                ~kEmbedderDataSlotPayloadTag;
     *out_pointer = reinterpret_cast<void*>(raw_value);
     return true;
   }
   return false;
 #else
-  return ToAlignedPointer(isolate_root, out_pointer);
+  return ToAlignedPointer(isolate, out_pointer);
 #endif  // V8_HEAP_SANDBOX
 }
 
@@ -150,7 +136,7 @@ bool EmbedderDataSlot::store_aligned_pointer(Isolate* isolate, void* ptr) {
         ObjectSlot(address() + kRawPayloadOffset).Relaxed_Load();
     uint32_t index = static_cast<uint32_t>(index_as_object.ptr());
     isolate->external_pointer_table().set(index,
-                                          value ^ kEmbedderDataSlotPayloadTag);
+                                          value | kEmbedderDataSlotPayloadTag);
     return true;
   }
 #endif
diff --git a/chromium/v8/src/objects/embedder-data-slot.h b/chromium/v8/src/objects/embedder-data-slot.h
index 65fe78403a2..6213b7b333c 100644
--- a/chromium/v8/src/objects/embedder-data-slot.h
+++ b/chromium/v8/src/objects/embedder-data-slot.h
@@ -75,8 +75,7 @@ class EmbedderDataSlot
   // When V8 heap sandbox is enabled, calling this method when the raw part of
   // the slot does not contain valid external pointer table index is undefined
   // behaviour and most likely result in crashes.
-  V8_INLINE bool ToAlignedPointer(PtrComprCageBase isolate_root,
-                                  void** out_result) const;
+  V8_INLINE bool ToAlignedPointer(Isolate* isolate, void** out_result) const;
 
   // Same as ToAlignedPointer() but with a workaround for V8 heap sandbox.
   // When V8 heap sandbox is enabled, this method doesn't crash when the raw
@@ -87,7 +86,7 @@ class EmbedderDataSlot
   //
   // Call this function if you are not sure whether the slot contains valid
   // external pointer or not.
-  V8_INLINE bool ToAlignedPointerSafe(PtrComprCageBase isolate_root,
+  V8_INLINE bool ToAlignedPointerSafe(Isolate* isolate,
                                       void** out_result) const;
 
   // Returns true if the pointer was successfully stored or false it the pointer
diff --git a/chromium/v8/src/objects/feedback-vector-inl.h b/chromium/v8/src/objects/feedback-vector-inl.h
index 8853dabdbdb..aea13c5fd6d 100644
--- a/chromium/v8/src/objects/feedback-vector-inl.h
+++ b/chromium/v8/src/objects/feedback-vector-inl.h
@@ -182,14 +182,15 @@ bool FeedbackVector::IsOfLegacyType(MaybeObject value) {
 #endif  // DEBUG
 
 MaybeObject FeedbackVector::Get(FeedbackSlot slot) const {
-  MaybeObject value = raw_feedback_slots(GetIndex(slot));
+  MaybeObject value = raw_feedback_slots(GetIndex(slot), kRelaxedLoad);
   DCHECK(!IsOfLegacyType(value));
   return value;
 }
 
 MaybeObject FeedbackVector::Get(PtrComprCageBase cage_base,
                                 FeedbackSlot slot) const {
-  MaybeObject value = raw_feedback_slots(cage_base, GetIndex(slot));
+  MaybeObject value =
+      raw_feedback_slots(cage_base, GetIndex(slot), kRelaxedLoad);
   DCHECK(!IsOfLegacyType(value));
   return value;
 }
@@ -335,6 +336,10 @@ Handle<Symbol> FeedbackVector::MegamorphicSentinel(Isolate* isolate) {
   return isolate->factory()->megamorphic_symbol();
 }
 
+Handle<Symbol> FeedbackVector::MegaDOMSentinel(Isolate* isolate) {
+  return isolate->factory()->mega_dom_symbol();
+}
+
 Symbol FeedbackVector::RawUninitializedSentinel(Isolate* isolate) {
   return ReadOnlyRoots(isolate).uninitialized_symbol();
 }
@@ -377,6 +382,11 @@ MaybeObject FeedbackNexus::MegamorphicSentinel() const {
       *FeedbackVector::MegamorphicSentinel(GetIsolate()));
 }
 
+MaybeObject FeedbackNexus::MegaDOMSentinel() const {
+  return MaybeObject::FromObject(
+      *FeedbackVector::MegaDOMSentinel(GetIsolate()));
+}
+
 MaybeObject FeedbackNexus::FromHandle(MaybeObjectHandle slot) const {
   return slot.is_null() ? HeapObjectReference::ClearedValue(config()->isolate())
                         : *slot;
diff --git a/chromium/v8/src/objects/feedback-vector.cc b/chromium/v8/src/objects/feedback-vector.cc
index a77ea5d265f..5f4cf592b08 100644
--- a/chromium/v8/src/objects/feedback-vector.cc
+++ b/chromium/v8/src/objects/feedback-vector.cc
@@ -54,6 +54,7 @@ static bool IsPropertyNameFeedback(MaybeObject feedback) {
   Symbol symbol = Symbol::cast(heap_object);
   ReadOnlyRoots roots = symbol.GetReadOnlyRoots();
   return symbol != roots.uninitialized_symbol() &&
+         symbol != roots.mega_dom_symbol() &&
          symbol != roots.megamorphic_symbol();
 }
 
@@ -75,8 +76,8 @@ void FeedbackMetadata::SetKind(FeedbackSlot slot, FeedbackSlotKind kind) {
 }
 
 // static
-template <typename LocalIsolate>
-Handle<FeedbackMetadata> FeedbackMetadata::New(LocalIsolate* isolate,
+template <typename IsolateT>
+Handle<FeedbackMetadata> FeedbackMetadata::New(IsolateT* isolate,
                                                const FeedbackVectorSpec* spec) {
   auto* factory = isolate->factory();
 
@@ -253,8 +254,6 @@ Handle<FeedbackVector> FeedbackVector::New(
   DCHECK_EQ(vector->optimization_marker(),
             FLAG_log_function_events ? OptimizationMarker::kLogFirstExecution
                                      : OptimizationMarker::kNone);
-  // TODO(mythria): This might change if NCI code is installed on feedback
-  // vector. Update this accordingly.
   DCHECK_EQ(vector->optimization_tier(), OptimizationTier::kNone);
   DCHECK_EQ(vector->invocation_count(), 0);
   DCHECK_EQ(vector->profiler_ticks(), 0);
@@ -676,6 +675,13 @@ bool FeedbackNexus::ConfigureMegamorphic() {
   return false;
 }
 
+void FeedbackNexus::ConfigureMegaDOM(const MaybeObjectHandle& handler) {
+  DisallowGarbageCollection no_gc;
+  MaybeObject sentinel = MegaDOMSentinel();
+
+  SetFeedback(sentinel, SKIP_WRITE_BARRIER, *handler, UPDATE_WRITE_BARRIER);
+}
+
 bool FeedbackNexus::ConfigureMegamorphic(IcCheckType property_type) {
   DisallowGarbageCollection no_gc;
   MaybeObject sentinel = MegamorphicSentinel();
@@ -737,6 +743,10 @@ InlineCacheState FeedbackNexus::ic_state() const {
       if (feedback == MegamorphicSentinel()) {
         return MEGAMORPHIC;
       }
+      if (feedback == MegaDOMSentinel()) {
+        DCHECK(IsLoadICKind(kind()));
+        return MEGADOM;
+      }
       if (feedback->IsWeakOrCleared()) {
         // Don't check if the map is cleared.
         return MONOMORPHIC;
@@ -999,6 +1009,15 @@ SpeculationMode FeedbackNexus::GetSpeculationMode() {
   return SpeculationModeField::decode(value);
 }
 
+CallFeedbackContent FeedbackNexus::GetCallFeedbackContent() {
+  DCHECK(IsCallICKind(kind()));
+
+  Object call_count = GetFeedbackExtra()->cast<Object>();
+  CHECK(call_count.IsSmi());
+  uint32_t value = static_cast<uint32_t>(Smi::ToInt(call_count));
+  return CallFeedbackContentField::decode(value);
+}
+
 float FeedbackNexus::ComputeCallFrequency() {
   DCHECK(IsCallICKind(kind()));
 
@@ -1407,52 +1426,6 @@ std::vector<Handle<String>> FeedbackNexus::GetTypesForSourcePositions(
   return types_for_position;
 }
 
-namespace {
-
-Handle<JSObject> ConvertToJSObject(Isolate* isolate,
-                                   Handle<SimpleNumberDictionary> feedback) {
-  Handle<JSObject> type_profile =
-      isolate->factory()->NewJSObject(isolate->object_function());
-
-  for (int index = SimpleNumberDictionary::kElementsStartIndex;
-       index < feedback->length();
-       index += SimpleNumberDictionary::kEntrySize) {
-    int key_index = index + SimpleNumberDictionary::kEntryKeyIndex;
-    Object key = feedback->get(key_index);
-    if (key.IsSmi()) {
-      int value_index = index + SimpleNumberDictionary::kEntryValueIndex;
-
-      Handle<ArrayList> position_specific_types(
-          ArrayList::cast(feedback->get(value_index)), isolate);
-
-      int position = Smi::ToInt(key);
-      JSObject::AddDataElement(
-          type_profile, position,
-          isolate->factory()->NewJSArrayWithElements(
-              ArrayList::Elements(isolate, position_specific_types)),
-          PropertyAttributes::NONE);
-    }
-  }
-  return type_profile;
-}
-}  // namespace
-
-JSObject FeedbackNexus::GetTypeProfile() const {
-  DCHECK(IsTypeProfileKind(kind()));
-  Isolate* isolate = GetIsolate();
-
-  MaybeObject const feedback = GetFeedback();
-
-  if (feedback == UninitializedSentinel()) {
-    return *isolate->factory()->NewJSObject(isolate->object_function());
-  }
-
-  return *ConvertToJSObject(isolate,
-                            handle(SimpleNumberDictionary::cast(
-                                       feedback->GetHeapObjectAssumeStrong()),
-                                   isolate));
-}
-
 void FeedbackNexus::ResetTypeProfile() {
   DCHECK(IsTypeProfileKind(kind()));
   SetFeedback(UninitializedSentinel());
diff --git a/chromium/v8/src/objects/feedback-vector.h b/chromium/v8/src/objects/feedback-vector.h
index cc5e867f720..07aad24430e 100644
--- a/chromium/v8/src/objects/feedback-vector.h
+++ b/chromium/v8/src/objects/feedback-vector.h
@@ -130,8 +130,8 @@ inline bool IsCloneObjectKind(FeedbackSlotKind kind) {
 inline TypeofMode GetTypeofModeFromSlotKind(FeedbackSlotKind kind) {
   DCHECK(IsLoadGlobalICKind(kind));
   return (kind == FeedbackSlotKind::kLoadGlobalInsideTypeof)
-             ? INSIDE_TYPEOF
-             : NOT_INSIDE_TYPEOF;
+             ? TypeofMode::kInside
+             : TypeofMode::kNotInside;
 }
 
 inline LanguageMode GetLanguageModeFromSlotKind(FeedbackSlotKind kind) {
@@ -311,7 +311,7 @@ class FeedbackVector
 
   DECL_PRINTER(FeedbackVector)
 
-  void FeedbackSlotPrint(std::ostream& os, FeedbackSlot slot);  // NOLINT
+  void FeedbackSlotPrint(std::ostream& os, FeedbackSlot slot);
 
   // Clears the vector slots. Return true if feedback has changed.
   bool ClearSlots(Isolate* isolate);
@@ -322,6 +322,9 @@ class FeedbackVector
   // The object that indicates a megamorphic state.
   static inline Handle<Symbol> MegamorphicSentinel(Isolate* isolate);
 
+  // The object that indicates a MegaDOM state.
+  static inline Handle<Symbol> MegaDOMSentinel(Isolate* isolate);
+
   // A raw version of the uninitialized sentinel that's safe to read during
   // garbage collection (e.g., for patching the cache).
   static inline Symbol RawUninitializedSentinel(Isolate* isolate);
@@ -389,7 +392,7 @@ class V8_EXPORT_PRIVATE FeedbackVectorSpec {
   }
 
   FeedbackSlot AddLoadGlobalICSlot(TypeofMode typeof_mode) {
-    return AddSlot(typeof_mode == INSIDE_TYPEOF
+    return AddSlot(typeof_mode == TypeofMode::kInside
                        ? FeedbackSlotKind::kLoadGlobalInsideTypeof
                        : FeedbackSlotKind::kLoadGlobalNotInsideTypeof);
   }
@@ -532,9 +535,9 @@ class FeedbackMetadata : public HeapObject {
   V8_EXPORT_PRIVATE FeedbackSlotKind GetKind(FeedbackSlot slot) const;
 
   // If {spec} is null, then it is considered empty.
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   V8_EXPORT_PRIVATE static Handle<FeedbackMetadata> New(
-      LocalIsolate* isolate, const FeedbackVectorSpec* spec = nullptr);
+      IsolateT* isolate, const FeedbackVectorSpec* spec = nullptr);
 
   DECL_PRINTER(FeedbackMetadata)
   DECL_VERIFIER(FeedbackMetadata)
@@ -588,7 +591,6 @@ class FeedbackMetadata : public HeapObject {
 
 // Verify that an empty hash field looks like a tagged object, but can't
 // possibly be confused with a pointer.
-// NOLINTNEXTLINE(runtime/references) (false positive)
 STATIC_ASSERT((Name::kEmptyHashField & kHeapObjectTag) == kHeapObjectTag);
 STATIC_ASSERT(Name::kEmptyHashField == 0x3);
 // Verify that a set hash field will not look like a tagged object.
@@ -728,7 +730,7 @@ class V8_EXPORT_PRIVATE FeedbackNexus final {
   bool IsMegamorphic() const { return ic_state() == MEGAMORPHIC; }
   bool IsGeneric() const { return ic_state() == GENERIC; }
 
-  void Print(std::ostream& os);  // NOLINT
+  void Print(std::ostream& os);
 
   // For map-based ICs (load, keyed-load, store, keyed-store).
   Map GetFirstMap() const;
@@ -773,6 +775,8 @@ class V8_EXPORT_PRIVATE FeedbackNexus final {
   void ConfigurePolymorphic(
       Handle<Name> name, std::vector<MapAndHandler> const& maps_and_handlers);
 
+  void ConfigureMegaDOM(const MaybeObjectHandle& handler);
+
   BinaryOperationHint GetBinaryOperationFeedback() const;
   CompareOperationHint GetCompareOperationFeedback() const;
   ForInHint GetForInFeedback() const;
@@ -791,13 +795,15 @@ class V8_EXPORT_PRIVATE FeedbackNexus final {
   int GetCallCount();
   void SetSpeculationMode(SpeculationMode mode);
   SpeculationMode GetSpeculationMode();
+  CallFeedbackContent GetCallFeedbackContent();
 
   // Compute the call frequency based on the call count and the invocation
   // count (taken from the type feedback vector).
   float ComputeCallFrequency();
 
   using SpeculationModeField = base::BitField<SpeculationMode, 0, 1>;
-  using CallCountField = base::BitField<uint32_t, 1, 31>;
+  using CallFeedbackContentField = base::BitField<CallFeedbackContent, 1, 1>;
+  using CallCountField = base::BitField<uint32_t, 2, 30>;
 
   // For InstanceOf ICs.
   MaybeHandle<JSObject> GetConstructorFeedback() const;
@@ -831,7 +837,6 @@ class V8_EXPORT_PRIVATE FeedbackNexus final {
 
   // Add a type to the list of types for source position <position>.
   void Collect(Handle<String> type, int position);
-  JSObject GetTypeProfile() const;
 
   std::vector<int> GetSourcePositions() const;
   std::vector<Handle<String>> GetTypesForSourcePositions(uint32_t pos) const;
@@ -847,6 +852,7 @@ class V8_EXPORT_PRIVATE FeedbackNexus final {
 
   inline MaybeObject UninitializedSentinel() const;
   inline MaybeObject MegamorphicSentinel() const;
+  inline MaybeObject MegaDOMSentinel() const;
 
   // Create an array. The caller must install it in a feedback vector slot.
   Handle<WeakFixedArray> CreateArrayOfSize(int length);
diff --git a/chromium/v8/src/objects/feedback-vector.tq b/chromium/v8/src/objects/feedback-vector.tq
index a84533db676..768254f1870 100644
--- a/chromium/v8/src/objects/feedback-vector.tq
+++ b/chromium/v8/src/objects/feedback-vector.tq
@@ -24,7 +24,7 @@ extern class FeedbackVector extends HeapObject {
   shared_function_info: SharedFunctionInfo;
   maybe_optimized_code: Weak<Code>;
   closure_feedback_cell_array: ClosureFeedbackCellArray;
-  @relaxedRead raw_feedback_slots[length]: MaybeObject;
+  @cppRelaxedLoad raw_feedback_slots[length]: MaybeObject;
 }
 
 extern class FeedbackMetadata extends HeapObject;
diff --git a/chromium/v8/src/objects/fixed-array-inl.h b/chromium/v8/src/objects/fixed-array-inl.h
index cca6d400705..43b77539e14 100644
--- a/chromium/v8/src/objects/fixed-array-inl.h
+++ b/chromium/v8/src/objects/fixed-array-inl.h
@@ -19,7 +19,6 @@
 #include "src/objects/oddball.h"
 #include "src/objects/slots.h"
 #include "src/roots/roots-inl.h"
-#include "src/sanitizer/tsan.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
@@ -45,13 +44,11 @@ TQ_OBJECT_CONSTRUCTORS_IMPL(WeakArrayList)
 
 NEVER_READ_ONLY_SPACE_IMPL(WeakArrayList)
 
-SYNCHRONIZED_SMI_ACCESSORS(FixedArrayBase, length, kLengthOffset)
+RELEASE_ACQUIRE_SMI_ACCESSORS(FixedArrayBase, length, kLengthOffset)
 
-SYNCHRONIZED_SMI_ACCESSORS(WeakFixedArray, length, kLengthOffset)
+RELEASE_ACQUIRE_SMI_ACCESSORS(WeakFixedArray, length, kLengthOffset)
 
-SYNCHRONIZED_SMI_ACCESSORS(WeakArrayList, capacity, kCapacityOffset)
-
-Object FixedArrayBase::unchecked_synchronized_length() const {
+Object FixedArrayBase::unchecked_length(AcquireLoadTag) const {
   return ACQUIRE_READ_FIELD(*this, kLengthOffset);
 }
 
@@ -243,15 +240,11 @@ void FixedArray::CopyElements(Isolate* isolate, int dst_index, FixedArray src,
 // Due to left- and right-trimming, concurrent visitors need to read the length
 // with acquire semantics.
 // TODO(ulan): Acquire should not be needed anymore.
-inline int FixedArray::AllocatedSize() {
-  return SizeFor(synchronized_length());
-}
+inline int FixedArray::AllocatedSize() { return SizeFor(length(kAcquireLoad)); }
 inline int WeakFixedArray::AllocatedSize() {
-  return SizeFor(synchronized_length());
-}
-inline int WeakArrayList::AllocatedSize() {
-  return SizeFor(synchronized_capacity());
+  return SizeFor(length(kAcquireLoad));
 }
+inline int WeakArrayList::AllocatedSize() { return SizeFor(capacity()); }
 
 // Perform a binary search in a fixed array.
 template <SearchMode search_mode, typename T>
@@ -445,7 +438,7 @@ MaybeObject WeakFixedArray::Get(int index) const {
 
 MaybeObject WeakFixedArray::Get(PtrComprCageBase cage_base, int index) const {
   DCHECK_LT(static_cast<unsigned>(index), static_cast<unsigned>(length()));
-  return objects(cage_base, index);
+  return objects(cage_base, index, kRelaxedLoad);
 }
 
 void WeakFixedArray::Set(int index, MaybeObject value, WriteBarrierMode mode) {
@@ -480,7 +473,7 @@ MaybeObject WeakArrayList::Get(int index) const {
 
 MaybeObject WeakArrayList::Get(PtrComprCageBase cage_base, int index) const {
   DCHECK_LT(static_cast<unsigned>(index), static_cast<unsigned>(capacity()));
-  return objects(cage_base, index);
+  return objects(cage_base, index, kRelaxedLoad);
 }
 
 void WeakArrayList::Set(int index, MaybeObject value, WriteBarrierMode mode) {
diff --git a/chromium/v8/src/objects/fixed-array.h b/chromium/v8/src/objects/fixed-array.h
index 98c5d8d5b5c..d6c5077aa0f 100644
--- a/chromium/v8/src/objects/fixed-array.h
+++ b/chromium/v8/src/objects/fixed-array.h
@@ -71,10 +71,12 @@ enum FixedArraySubInstanceType {
 class FixedArrayBase
     : public TorqueGeneratedFixedArrayBase<FixedArrayBase, HeapObject> {
  public:
-  // Get and set the length using acquire loads and release stores.
-  DECL_SYNCHRONIZED_INT_ACCESSORS(length)
+  // Forward declare the non-atomic (set_)length defined in torque.
+  using TorqueGeneratedFixedArrayBase::length;
+  using TorqueGeneratedFixedArrayBase::set_length;
+  DECL_RELEASE_ACQUIRE_INT_ACCESSORS(length)
 
-  inline Object unchecked_synchronized_length() const;
+  inline Object unchecked_length(AcquireLoadTag) const;
 
   static int GetMaxLengthForNewSpaceAllocation(ElementsKind kind);
 
@@ -283,8 +285,10 @@ class WeakFixedArray
       int index, MaybeObject value,
       WriteBarrierMode mode = WriteBarrierMode::UPDATE_WRITE_BARRIER);
 
-  // Get and set the length using acquire loads and release stores.
-  DECL_SYNCHRONIZED_INT_ACCESSORS(length)
+  // Forward declare the non-atomic (set_)length defined in torque.
+  using TorqueGeneratedWeakFixedArray::length;
+  using TorqueGeneratedWeakFixedArray::set_length;
+  DECL_RELEASE_ACQUIRE_INT_ACCESSORS(length)
 
   // Gives access to raw memory which stores the array's data.
   inline MaybeObjectSlot data_start();
@@ -376,9 +380,6 @@ class WeakArrayList
 
   V8_EXPORT_PRIVATE bool IsFull();
 
-  // Get and set the capacity using acquire loads and release stores.
-  DECL_SYNCHRONIZED_INT_ACCESSORS(capacity)
-
   int AllocatedSize();
 
   class BodyDescriptor;
diff --git a/chromium/v8/src/objects/fixed-array.tq b/chromium/v8/src/objects/fixed-array.tq
index 6aed0c26b27..31198d70d4a 100644
--- a/chromium/v8/src/objects/fixed-array.tq
+++ b/chromium/v8/src/objects/fixed-array.tq
@@ -26,7 +26,7 @@ extern class FixedDoubleArray extends FixedArrayBase {
 @generateCppClass
 extern class WeakFixedArray extends HeapObject {
   const length: Smi;
-  @relaxedRead objects[length]: MaybeObject;
+  @cppRelaxedLoad objects[length]: MaybeObject;
 }
 
 @generateCppClass
@@ -51,7 +51,7 @@ extern class TemplateList extends FixedArray {
 extern class WeakArrayList extends HeapObject {
   const capacity: Smi;
   length: Smi;
-  @relaxedRead objects[capacity]: MaybeObject;
+  @cppRelaxedLoad objects[capacity]: MaybeObject;
 }
 
 extern operator '.length_intptr' macro LoadAndUntagFixedArrayBaseLength(
diff --git a/chromium/v8/src/objects/foreign-inl.h b/chromium/v8/src/objects/foreign-inl.h
index 150857f49a0..a278c844b92 100644
--- a/chromium/v8/src/objects/foreign-inl.h
+++ b/chromium/v8/src/objects/foreign-inl.h
@@ -29,7 +29,8 @@ bool Foreign::IsNormalized(Object value) {
 }
 
 DEF_GETTER(Foreign, foreign_address, Address) {
-  return ReadExternalPointerField(kForeignAddressOffset, cage_base,
+  Isolate* isolate = GetIsolateForHeapSandbox(*this);
+  return ReadExternalPointerField(kForeignAddressOffset, isolate,
                                   kForeignForeignAddressTag);
 }
 
diff --git a/chromium/v8/src/objects/free-space-inl.h b/chromium/v8/src/objects/free-space-inl.h
index e8ce1d63507..443ff25caa6 100644
--- a/chromium/v8/src/objects/free-space-inl.h
+++ b/chromium/v8/src/objects/free-space-inl.h
@@ -23,7 +23,7 @@ TQ_OBJECT_CONSTRUCTORS_IMPL(FreeSpace)
 
 RELAXED_SMI_ACCESSORS(FreeSpace, size, kSizeOffset)
 
-int FreeSpace::Size() { return size(); }
+int FreeSpace::Size() { return size(kRelaxedLoad); }
 
 FreeSpace FreeSpace::next() {
   DCHECK(IsValid());
@@ -50,10 +50,10 @@ bool FreeSpace::IsValid() {
   Heap* heap = GetHeapFromWritableObject(*this);
   Object free_space_map =
       Isolate::FromHeap(heap)->root(RootIndex::kFreeSpaceMap);
-  CHECK_IMPLIES(!map_slot().contains_value(free_space_map.ptr()),
+  CHECK_IMPLIES(!map_slot().contains_map_value(free_space_map.ptr()),
                 !heap->deserialization_complete() &&
-                    map_slot().contains_value(kNullAddress));
-  CHECK_LE(kNextOffset + kTaggedSize, relaxed_read_size());
+                    map_slot().contains_map_value(kNullAddress));
+  CHECK_LE(kNextOffset + kTaggedSize, size(kRelaxedLoad));
   return true;
 }
 
diff --git a/chromium/v8/src/objects/free-space.h b/chromium/v8/src/objects/free-space.h
index 76d618cbfdb..d2f569bb33a 100644
--- a/chromium/v8/src/objects/free-space.h
+++ b/chromium/v8/src/objects/free-space.h
@@ -23,8 +23,7 @@ namespace internal {
 class FreeSpace : public TorqueGeneratedFreeSpace<FreeSpace, HeapObject> {
  public:
   // [size]: size of the free space including the header.
-  inline int relaxed_read_size() const;
-  inline void relaxed_write_size(int value);
+  DECL_RELAXED_SMI_ACCESSORS(size)
 
   inline int Size();
 
diff --git a/chromium/v8/src/objects/function-kind.h b/chromium/v8/src/objects/function-kind.h
index b863f9c72fc..02b5b7636a1 100644
--- a/chromium/v8/src/objects/function-kind.h
+++ b/chromium/v8/src/objects/function-kind.h
@@ -181,6 +181,14 @@ inline bool BindsSuper(FunctionKind kind) {
          IsClassConstructor(kind);
 }
 
+inline bool IsAwaitAsIdentifierDisallowed(FunctionKind kind) {
+  // 'await' is always disallowed as an identifier in module contexts. Callers
+  // should short-circuit the module case instead of calling this.
+  DCHECK(!IsModule(kind));
+  return IsAsyncFunction(kind) ||
+         kind == FunctionKind::kClassStaticInitializerFunction;
+}
+
 inline const char* FunctionKind2String(FunctionKind kind) {
   switch (kind) {
     case FunctionKind::kNormalFunction:
diff --git a/chromium/v8/src/objects/hash-table-inl.h b/chromium/v8/src/objects/hash-table-inl.h
index 27645058b30..19382cc7ec1 100644
--- a/chromium/v8/src/objects/hash-table-inl.h
+++ b/chromium/v8/src/objects/hash-table-inl.h
@@ -130,9 +130,8 @@ Handle<Map> EphemeronHashTable::GetMap(ReadOnlyRoots roots) {
 }
 
 template <typename Derived, typename Shape>
-template <typename LocalIsolate>
-InternalIndex HashTable<Derived, Shape>::FindEntry(LocalIsolate* isolate,
-                                                   Key key) {
+template <typename IsolateT>
+InternalIndex HashTable<Derived, Shape>::FindEntry(IsolateT* isolate, Key key) {
   ReadOnlyRoots roots(isolate);
   return FindEntry(isolate, roots, key, Shape::Hash(roots, key));
 }
diff --git a/chromium/v8/src/objects/hash-table.h b/chromium/v8/src/objects/hash-table.h
index 12ac020fb76..c17a15c95f3 100644
--- a/chromium/v8/src/objects/hash-table.h
+++ b/chromium/v8/src/objects/hash-table.h
@@ -125,9 +125,9 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) HashTable
   using Key = typename Shape::Key;
 
   // Returns a new HashTable object.
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   V8_WARN_UNUSED_RESULT static Handle<Derived> New(
-      LocalIsolate* isolate, int at_least_space_for,
+      IsolateT* isolate, int at_least_space_for,
       AllocationType allocation = AllocationType::kYoung,
       MinimumCapacity capacity_option = USE_DEFAULT_MINIMUM_CAPACITY);
 
@@ -140,8 +140,8 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) HashTable
   // Find entry for key otherwise return kNotFound.
   inline InternalIndex FindEntry(PtrComprCageBase cage_base,
                                  ReadOnlyRoots roots, Key key, int32_t hash);
-  template <typename LocalIsolate>
-  inline InternalIndex FindEntry(LocalIsolate* isolate, Key key);
+  template <typename IsolateT>
+  inline InternalIndex FindEntry(IsolateT* isolate, Key key);
 
   // Rehashes the table in-place.
   void Rehash(PtrComprCageBase cage_base);
@@ -194,9 +194,9 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) HashTable
   }
 
   // Ensure enough space for n additional elements.
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   V8_WARN_UNUSED_RESULT static Handle<Derived> EnsureCapacity(
-      LocalIsolate* isolate, Handle<Derived> table, int n = 1,
+      IsolateT* isolate, Handle<Derived> table, int n = 1,
       AllocationType allocation = AllocationType::kYoung);
 
   // Returns true if this table has sufficient capacity for adding n elements.
@@ -212,9 +212,9 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) HashTable
  protected:
   friend class ObjectHashTable;
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   V8_WARN_UNUSED_RESULT static Handle<Derived> NewInternal(
-      LocalIsolate* isolate, int capacity, AllocationType allocation);
+      IsolateT* isolate, int capacity, AllocationType allocation);
 
   // Find the entry at which to insert element with the given key that
   // has the given hash value.
diff --git a/chromium/v8/src/objects/heap-object.h b/chromium/v8/src/objects/heap-object.h
index e0aea975371..128e17fab1b 100644
--- a/chromium/v8/src/objects/heap-object.h
+++ b/chromium/v8/src/objects/heap-object.h
@@ -43,8 +43,8 @@ class HeapObject : public Object {
   inline void set_map_no_write_barrier(Map value);
 
   // Access the map using acquire load and release store.
-  DECL_GETTER(synchronized_map, Map)
-  inline void synchronized_set_map(Map value);
+  DECL_ACQUIRE_GETTER(map, Map)
+  inline void set_map(Map value, ReleaseStoreTag);
 
   // Compare-and-swaps map word using release store, returns true if the map
   // word was actually swapped.
@@ -58,12 +58,12 @@ class HeapObject : public Object {
 
   // During garbage collection, the map word of a heap object does not
   // necessarily contain a map pointer.
-  DECL_GETTER(map_word, MapWord)
-  inline void set_map_word(MapWord map_word);
+  DECL_RELAXED_GETTER(map_word, MapWord)
+  inline void set_map_word(MapWord map_word, RelaxedStoreTag);
 
   // Access the map word using acquire load and release store.
-  DECL_GETTER(synchronized_map_word, MapWord)
-  inline void synchronized_set_map_word(MapWord map_word);
+  DECL_ACQUIRE_GETTER(map_word, MapWord)
+  inline void set_map_word(MapWord map_word, ReleaseStoreTag);
 
   // This method exists to help remove GetIsolate/GetHeap from HeapObject, in a
   // way that doesn't require passing Isolate/Heap down huge call chains or to
@@ -163,9 +163,9 @@ class HeapObject : public Object {
       const DisallowGarbageCollection& promise);
 
   // Dispatched behavior.
-  void HeapObjectShortPrint(std::ostream& os);  // NOLINT
+  void HeapObjectShortPrint(std::ostream& os);
 #ifdef OBJECT_PRINT
-  void PrintHeader(std::ostream& os, const char* id);  // NOLINT
+  void PrintHeader(std::ostream& os, const char* id);
 #endif
   DECL_PRINTER(HeapObject)
   EXPORT_DECL_VERIFIER(HeapObject)
diff --git a/chromium/v8/src/objects/instance-type-inl.h b/chromium/v8/src/objects/instance-type-inl.h
index 8edb73d666a..32ee7a24f53 100644
--- a/chromium/v8/src/objects/instance-type-inl.h
+++ b/chromium/v8/src/objects/instance-type-inl.h
@@ -31,14 +31,14 @@ struct InstanceRangeChecker {
 template <InstanceType upper_limit>
 struct InstanceRangeChecker<FIRST_TYPE, upper_limit> {
   static constexpr bool Check(InstanceType value) {
-    CONSTEXPR_DCHECK(FIRST_TYPE <= value);
+    DCHECK_LE(FIRST_TYPE, value);
     return value <= upper_limit;
   }
 };
 template <InstanceType lower_limit>
 struct InstanceRangeChecker<lower_limit, LAST_TYPE> {
   static constexpr bool Check(InstanceType value) {
-    CONSTEXPR_DCHECK(LAST_TYPE >= value);
+    DCHECK_GE(LAST_TYPE, value);
     return value >= lower_limit;
   }
 };
diff --git a/chromium/v8/src/objects/instance-type.h b/chromium/v8/src/objects/instance-type.h
index 9c8c8d5d63d..7a11f9cf688 100644
--- a/chromium/v8/src/objects/instance-type.h
+++ b/chromium/v8/src/objects/instance-type.h
@@ -33,16 +33,11 @@ enum StringRepresentationTag {
 };
 const uint32_t kIsIndirectStringMask = 1 << 0;
 const uint32_t kIsIndirectStringTag = 1 << 0;
-// NOLINTNEXTLINE(runtime/references) (false positive)
 STATIC_ASSERT((kSeqStringTag & kIsIndirectStringMask) == 0);
-// NOLINTNEXTLINE(runtime/references) (false positive)
 STATIC_ASSERT((kExternalStringTag & kIsIndirectStringMask) == 0);
-// NOLINTNEXTLINE(runtime/references) (false positive)
 STATIC_ASSERT((kConsStringTag & kIsIndirectStringMask) == kIsIndirectStringTag);
-// NOLINTNEXTLINE(runtime/references) (false positive)
 STATIC_ASSERT((kSlicedStringTag & kIsIndirectStringMask) ==
               kIsIndirectStringTag);
-// NOLINTNEXTLINE(runtime/references) (false positive)
 STATIC_ASSERT((kThinStringTag & kIsIndirectStringMask) == kIsIndirectStringTag);
 
 // For strings, bit 3 indicates whether the string consists of two-byte
@@ -152,7 +147,6 @@ enum InstanceType : uint16_t {
 constexpr InstanceType LAST_STRING_TYPE =
     static_cast<InstanceType>(FIRST_NONSTRING_TYPE - 1);
 
-// NOLINTNEXTLINE(runtime/references) (false positive)
 STATIC_ASSERT((FIRST_NONSTRING_TYPE & kIsNotStringMask) != kStringTag);
 STATIC_ASSERT(JS_OBJECT_TYPE == Internals::kJSObjectType);
 STATIC_ASSERT(JS_API_OBJECT_TYPE == Internals::kJSApiObjectType);
@@ -258,6 +252,7 @@ TYPED_ARRAYS(TYPED_ARRAY_IS_TYPE_FUNCTION_DECL)
   V(_, FunctionTemplateInfoMap, function_template_info_map,                    \
     FunctionTemplateInfo)                                                      \
   V(_, HeapNumberMap, heap_number_map, HeapNumber)                             \
+  V(_, MegaDomHandlerMap, mega_dom_handler_map, MegaDomHandler)                \
   V(_, MetaMap, meta_map, Map)                                                 \
   V(_, PreparseDataMap, preparse_data_map, PreparseData)                       \
   V(_, PrototypeInfoMap, prototype_info_map, PrototypeInfo)                    \
diff --git a/chromium/v8/src/objects/internal-index.h b/chromium/v8/src/objects/internal-index.h
index a241f3c686f..dec83cefe2a 100644
--- a/chromium/v8/src/objects/internal-index.h
+++ b/chromium/v8/src/objects/internal-index.h
@@ -40,8 +40,7 @@ class InternalIndex {
     return static_cast<uint32_t>(entry_);
   }
   constexpr int as_int() const {
-    CONSTEXPR_DCHECK(entry_ <=
-                     static_cast<size_t>(std::numeric_limits<int>::max()));
+    DCHECK_GE(std::numeric_limits<int>::max(), entry_);
     return static_cast<int>(entry_);
   }
 
diff --git a/chromium/v8/src/objects/intl-objects.cc b/chromium/v8/src/objects/intl-objects.cc
index d9fca11e735..f5be56df451 100644
--- a/chromium/v8/src/objects/intl-objects.cc
+++ b/chromium/v8/src/objects/intl-objects.cc
@@ -90,7 +90,7 @@ inline constexpr uint16_t ToLatin1Lower(uint16_t ch) {
 
 // Does not work for U+00DF (sharp-s), U+00B5 (micron), U+00FF.
 inline constexpr uint16_t ToLatin1Upper(uint16_t ch) {
-  CONSTEXPR_DCHECK(ch != 0xDF && ch != 0xB5 && ch != 0xFF);
+  DCHECK(ch != 0xDF && ch != 0xB5 && ch != 0xFF);
   return ch &
          ~((IsAsciiLower(ch) || (((ch & 0xE0) == 0xE0) && ch != 0xF7)) << 5);
 }
@@ -479,7 +479,12 @@ Handle<JSObject> InnerAddElement(Isolate* isolate, Handle<JSArray> array,
                         field_type_string, NONE);
 
   JSObject::AddProperty(isolate, element, factory->value_string(), value, NONE);
-  JSObject::AddDataElement(array, index, element, NONE);
+  // TODO(victorgomes): Temporarily forcing a fatal error here in case of
+  // overflow, until Intl::AddElement can handle exceptions.
+  if (JSObject::AddDataElement(array, index, element, NONE).IsNothing()) {
+    FATAL("Fatal JavaScript invalid array size when adding element");
+    UNREACHABLE();
+  }
   return element;
 }
 
@@ -568,7 +573,14 @@ std::set<std::string> Intl::BuildLocaleSet(
   for (const std::string& locale : icu_available_locales) {
     if (path != nullptr || validate_key != nullptr) {
       if (!ValidateResource(icu::Locale(locale.c_str()), path, validate_key)) {
-        continue;
+        // FIXME(chromium:1215606) Find a beter fix for nb->no fallback
+        if (locale != "nb") {
+          continue;
+        }
+        // Try no for nb
+        if (!ValidateResource(icu::Locale("no"), path, validate_key)) {
+          continue;
+        }
       }
     }
     locales.insert(locale);
@@ -1486,7 +1498,6 @@ icu::LocaleMatcher BuildLocaleMatcher(
       builder.addSupportedLocale(l);
     }
   }
-
   return builder.build(*status);
 }
 
@@ -1533,23 +1544,12 @@ std::string BestFitMatcher(Isolate* isolate,
                            const std::set<std::string>& available_locales,
                            const std::vector<std::string>& requested_locales) {
   UErrorCode status = U_ZERO_ERROR;
-  icu::LocaleMatcher matcher =
-      BuildLocaleMatcher(isolate, available_locales, &status);
-  DCHECK(U_SUCCESS(status));
-
   Iterator iter(requested_locales.cbegin(), requested_locales.cend());
-  std::string bestfit =
-      matcher.getBestMatch(iter, status)->toLanguageTag<std::string>(status);
-  if (U_FAILURE(status)) {
-    return DefaultLocale(isolate);
-  }
-  // We need to return the extensions with it.
-  for (auto it = requested_locales.begin(); it != requested_locales.end();
-       ++it) {
-    if (it->find(bestfit) == 0) {
-      return *it;
-    }
-  }
+  std::string bestfit = BuildLocaleMatcher(isolate, available_locales, &status)
+                            .getBestMatchResult(iter, status)
+                            .makeResolvedLocale(status)
+                            .toLanguageTag<std::string>(status);
+  DCHECK(U_SUCCESS(status));
   return bestfit;
 }
 
@@ -1561,32 +1561,29 @@ std::vector<std::string> BestFitSupportedLocales(
   UErrorCode status = U_ZERO_ERROR;
   icu::LocaleMatcher matcher =
       BuildLocaleMatcher(isolate, available_locales, &status);
-  DCHECK(U_SUCCESS(status));
-
-  std::string default_locale = DefaultLocale(isolate);
   std::vector<std::string> result;
-  for (auto it = requested_locales.cbegin(); it != requested_locales.cend();
-       it++) {
-    if (*it == default_locale) {
-      result.push_back(*it);
-    } else {
+  if (U_SUCCESS(status)) {
+    for (auto it = requested_locales.cbegin(); it != requested_locales.cend();
+         it++) {
       status = U_ZERO_ERROR;
       icu::Locale desired = icu::Locale::forLanguageTag(it->c_str(), status);
-      std::string bestfit = matcher.getBestMatch(desired, status)
-                                ->toLanguageTag<std::string>(status);
-      // We need to return the extensions with it.
-      if (U_SUCCESS(status) && it->find(bestfit) == 0) {
-        result.push_back(*it);
-      }
+      icu::LocaleMatcher::Result matched =
+          matcher.getBestMatchResult(desired, status);
+      if (U_FAILURE(status)) continue;
+      if (matched.getSupportedIndex() < 0) continue;
+      std::string bestfit =
+          matched.makeResolvedLocale(status).toLanguageTag<std::string>(status);
+      if (U_FAILURE(status)) continue;
+      result.push_back(bestfit);
     }
   }
   return result;
 }
 
 // ecma262 #sec-createarrayfromlist
-Handle<JSArray> CreateArrayFromList(Isolate* isolate,
-                                    std::vector<std::string> elements,
-                                    PropertyAttributes attr) {
+MaybeHandle<JSArray> CreateArrayFromList(Isolate* isolate,
+                                         std::vector<std::string> elements,
+                                         PropertyAttributes attr) {
   Factory* factory = isolate->factory();
   // Let array be ! ArrayCreate(0).
   Handle<JSArray> array = factory->NewJSArray(0);
@@ -1599,10 +1596,11 @@ Handle<JSArray> CreateArrayFromList(Isolate* isolate,
     const std::string& part = elements[i];
     Handle<String> value =
         factory->NewStringFromUtf8(CStrVector(part.c_str())).ToHandleChecked();
-    JSObject::AddDataElement(array, i, value, attr);
+    MAYBE_RETURN(JSObject::AddDataElement(array, i, value, attr),
+                 MaybeHandle<JSArray>());
   }
   // 5. Return array.
-  return array;
+  return MaybeHandle<JSArray>(array);
 }
 
 // ECMA 402 9.2.9 SupportedLocales(availableLocales, requestedLocales, options)
@@ -2042,23 +2040,15 @@ icu::TimeZone* ICUTimezoneCache::GetTimeZone() {
 bool ICUTimezoneCache::GetOffsets(double time_ms, bool is_utc,
                                   int32_t* raw_offset, int32_t* dst_offset) {
   UErrorCode status = U_ZERO_ERROR;
-  // TODO(jshin): ICU TimeZone class handles skipped time differently from
-  // Ecma 262 (https://github.com/tc39/ecma262/pull/778) and icu::TimeZone
-  // class does not expose the necessary API. Fixing
-  // http://bugs.icu-project.org/trac/ticket/13268 would make it easy to
-  // implement the proposed spec change. A proposed fix for ICU is
-  //    https://chromium-review.googlesource.com/851265 .
-  // In the meantime, use an internal (still public) API of icu::BasicTimeZone.
-  // Once it's accepted by the upstream, get rid of cast. Note that casting
-  // TimeZone to BasicTimeZone is safe because we know that icu::TimeZone used
-  // here is a BasicTimeZone.
   if (is_utc) {
     GetTimeZone()->getOffset(time_ms, false, *raw_offset, *dst_offset, status);
   } else {
+    // Note that casting TimeZone to BasicTimeZone is safe because we know that
+    // icu::TimeZone used here is a BasicTimeZone.
     static_cast<const icu::BasicTimeZone*>(GetTimeZone())
-        ->getOffsetFromLocal(time_ms, icu::BasicTimeZone::kFormer,
-                             icu::BasicTimeZone::kFormer, *raw_offset,
-                             *dst_offset, status);
+        ->getOffsetFromLocal(time_ms, UCAL_TZ_LOCAL_FORMER,
+                             UCAL_TZ_LOCAL_FORMER, *raw_offset, *dst_offset,
+                             status);
   }
 
   return U_SUCCESS(status);
diff --git a/chromium/v8/src/objects/intl-objects.h b/chromium/v8/src/objects/intl-objects.h
index d4b4feed686..ec0eb93873b 100644
--- a/chromium/v8/src/objects/intl-objects.h
+++ b/chromium/v8/src/objects/intl-objects.h
@@ -21,7 +21,7 @@
 #include "unicode/locid.h"
 #include "unicode/uversion.h"
 
-#define V8_MINIMUM_ICU_VERSION 68
+#define V8_MINIMUM_ICU_VERSION 69
 
 namespace U_ICU_NAMESPACE {
 class BreakIterator;
diff --git a/chromium/v8/src/objects/js-array-buffer-inl.h b/chromium/v8/src/objects/js-array-buffer-inl.h
index b4aa5e33b98..0fa5737ec71 100644
--- a/chromium/v8/src/objects/js-array-buffer-inl.h
+++ b/chromium/v8/src/objects/js-array-buffer-inl.h
@@ -43,7 +43,8 @@ void JSArrayBuffer::set_byte_length(size_t value) {
 }
 
 DEF_GETTER(JSArrayBuffer, backing_store, void*) {
-  Address value = ReadExternalPointerField(kBackingStoreOffset, cage_base,
+  Isolate* isolate = GetIsolateForHeapSandbox(*this);
+  Address value = ReadExternalPointerField(kBackingStoreOffset, isolate,
                                            kArrayBufferBackingStoreTag);
   return reinterpret_cast<void*>(value);
 }
@@ -167,6 +168,8 @@ BIT_FIELD_ACCESSORS(JSArrayBuffer, bit_field, is_asmjs_memory,
                     JSArrayBuffer::IsAsmJsMemoryBit)
 BIT_FIELD_ACCESSORS(JSArrayBuffer, bit_field, is_shared,
                     JSArrayBuffer::IsSharedBit)
+BIT_FIELD_ACCESSORS(JSArrayBuffer, bit_field, is_resizable,
+                    JSArrayBuffer::IsResizableBit)
 
 size_t JSArrayBufferView::byte_offset() const {
   return ReadField<size_t>(kByteOffsetOffset);
@@ -188,18 +191,57 @@ bool JSArrayBufferView::WasDetached() const {
   return JSArrayBuffer::cast(buffer()).was_detached();
 }
 
+BIT_FIELD_ACCESSORS(JSTypedArray, bit_field, is_length_tracking,
+                    JSTypedArray::IsLengthTrackingBit)
+BIT_FIELD_ACCESSORS(JSTypedArray, bit_field, is_backed_by_rab,
+                    JSTypedArray::IsBackedByRabBit)
+
+bool JSTypedArray::IsVariableLength() const {
+  return is_length_tracking() || is_backed_by_rab();
+}
+
+size_t JSTypedArray::GetLength() const {
+  if (WasDetached()) return 0;
+  if (is_length_tracking()) {
+    if (is_backed_by_rab()) {
+      return buffer().byte_length() / element_size();
+    }
+    return buffer().GetBackingStore()->byte_length(std::memory_order_seq_cst) /
+           element_size();
+  }
+  size_t array_length = LengthUnchecked();
+  if (is_backed_by_rab()) {
+    // The sum can't overflow, since we have managed to allocate the
+    // JSTypedArray.
+    if (byte_offset() + array_length * element_size() >
+        buffer().byte_length()) {
+      return 0;
+    }
+  }
+  return array_length;
+}
+
 void JSTypedArray::AllocateExternalPointerEntries(Isolate* isolate) {
   InitExternalPointerField(kExternalPointerOffset, isolate);
 }
 
-size_t JSTypedArray::length() const { return ReadField<size_t>(kLengthOffset); }
+size_t JSTypedArray::length() const {
+  DCHECK(!is_length_tracking());
+  DCHECK(!is_backed_by_rab());
+  return ReadField<size_t>(kLengthOffset);
+}
+
+size_t JSTypedArray::LengthUnchecked() const {
+  return ReadField<size_t>(kLengthOffset);
+}
 
 void JSTypedArray::set_length(size_t value) {
   WriteField<size_t>(kLengthOffset, value);
 }
 
 DEF_GETTER(JSTypedArray, external_pointer, Address) {
-  return ReadExternalPointerField(kExternalPointerOffset, cage_base,
+  Isolate* isolate = GetIsolateForHeapSandbox(*this);
+  return ReadExternalPointerField(kExternalPointerOffset, isolate,
                                   kTypedArrayExternalPointerTag);
 }
 
@@ -320,8 +362,9 @@ MaybeHandle<JSTypedArray> JSTypedArray::Validate(Isolate* isolate,
 }
 
 DEF_GETTER(JSDataView, data_pointer, void*) {
+  Isolate* isolate = GetIsolateForHeapSandbox(*this);
   return reinterpret_cast<void*>(ReadExternalPointerField(
-      kDataPointerOffset, cage_base, kDataViewDataPointerTag));
+      kDataPointerOffset, isolate, kDataViewDataPointerTag));
 }
 
 void JSDataView::AllocateExternalPointerEntries(Isolate* isolate) {
diff --git a/chromium/v8/src/objects/js-array-buffer.cc b/chromium/v8/src/objects/js-array-buffer.cc
index 074a8dc1bf2..91175309f99 100644
--- a/chromium/v8/src/objects/js-array-buffer.cc
+++ b/chromium/v8/src/objects/js-array-buffer.cc
@@ -35,11 +35,12 @@ bool CanonicalNumericIndexString(Isolate* isolate, Handle<Object> s,
 }
 }  // anonymous namespace
 
-void JSArrayBuffer::Setup(SharedFlag shared,
+void JSArrayBuffer::Setup(SharedFlag shared, ResizableFlag resizable,
                           std::shared_ptr<BackingStore> backing_store) {
   clear_padding();
   set_bit_field(0);
   set_is_shared(shared == SharedFlag::kShared);
+  set_is_resizable(resizable == ResizableFlag::kResizable);
   set_is_detachable(shared != SharedFlag::kShared);
   for (int i = 0; i < v8::ArrayBuffer::kEmbedderFieldCount; i++) {
     SetEmbedderField(i, Smi::zero());
@@ -61,10 +62,17 @@ void JSArrayBuffer::Setup(SharedFlag shared,
 void JSArrayBuffer::Attach(std::shared_ptr<BackingStore> backing_store) {
   DCHECK_NOT_NULL(backing_store);
   DCHECK_EQ(is_shared(), backing_store->is_shared());
+  DCHECK_EQ(is_resizable(), backing_store->is_resizable());
   DCHECK(!was_detached());
   Isolate* isolate = GetIsolate();
   set_backing_store(isolate, backing_store->buffer_start());
-  set_byte_length(backing_store->byte_length());
+  if (is_shared() && is_resizable()) {
+    // GSABs need to read their byte_length from the BackingStore. Maintain the
+    // invariant that their byte_length field is always 0.
+    set_byte_length(0);
+  } else {
+    set_byte_length(backing_store->byte_length());
+  }
   if (backing_store->is_wasm_memory()) set_is_detachable(false);
   if (!backing_store->free_on_destruct()) set_is_external(true);
   Heap* heap = isolate->heap();
@@ -86,9 +94,12 @@ void JSArrayBuffer::Detach(bool force_for_wasm_memory) {
   }
 
   Isolate* const isolate = GetIsolate();
-  if (backing_store()) {
-    std::shared_ptr<BackingStore> backing_store;
-      backing_store = RemoveExtension();
+  ArrayBufferExtension* extension = this->extension();
+
+  if (extension) {
+    DisallowGarbageCollection disallow_gc;
+    isolate->heap()->DetachArrayBufferExtension(*this, extension);
+    std::shared_ptr<BackingStore> backing_store = RemoveExtension();
     CHECK_IMPLIES(force_for_wasm_memory, backing_store->is_wasm_memory());
   }
 
@@ -151,14 +162,14 @@ void JSArrayBuffer::YoungMarkExtensionPromoted() {
 Handle<JSArrayBuffer> JSTypedArray::GetBuffer() {
   Isolate* isolate = GetIsolate();
   Handle<JSTypedArray> self(*this, isolate);
-  DCHECK(IsTypedArrayElementsKind(self->GetElementsKind()));
-
+  DCHECK(IsTypedArrayOrRabGsabTypedArrayElementsKind(self->GetElementsKind()));
   Handle<JSArrayBuffer> array_buffer(JSArrayBuffer::cast(self->buffer()),
                                      isolate);
   if (!is_on_heap()) {
     // Already is off heap, so return the existing buffer.
     return array_buffer;
   }
+  DCHECK(!array_buffer->is_resizable());
 
   // The existing array buffer should be empty.
   DCHECK_NULL(array_buffer->backing_store());
@@ -179,7 +190,8 @@ Handle<JSArrayBuffer> JSTypedArray::GetBuffer() {
   }
 
   // Attach the backing store to the array buffer.
-  array_buffer->Setup(SharedFlag::kNotShared, std::move(backing_store));
+  array_buffer->Setup(SharedFlag::kNotShared, ResizableFlag::kNotResizable,
+                      std::move(backing_store));
 
   // Clear the elements of the typed array.
   self->set_elements(ReadOnlyRoots(isolate).empty_byte_array());
@@ -267,6 +279,7 @@ ExternalArrayType JSTypedArray::type() {
     return kExternal##Type##Array;
 
     TYPED_ARRAYS(ELEMENTS_KIND_TO_ARRAY_TYPE)
+    RAB_GSAB_TYPED_ARRAYS_WITH_TYPED_ARRAY_TYPE(ELEMENTS_KIND_TO_ARRAY_TYPE)
 #undef ELEMENTS_KIND_TO_ARRAY_TYPE
 
     default:
@@ -274,13 +287,14 @@ ExternalArrayType JSTypedArray::type() {
   }
 }
 
-size_t JSTypedArray::element_size() {
+size_t JSTypedArray::element_size() const {
   switch (map().elements_kind()) {
 #define ELEMENTS_KIND_TO_ELEMENT_SIZE(Type, type, TYPE, ctype) \
   case TYPE##_ELEMENTS:                                        \
     return sizeof(ctype);
 
     TYPED_ARRAYS(ELEMENTS_KIND_TO_ELEMENT_SIZE)
+    RAB_GSAB_TYPED_ARRAYS(ELEMENTS_KIND_TO_ELEMENT_SIZE)
 #undef ELEMENTS_KIND_TO_ELEMENT_SIZE
 
     default:
@@ -288,5 +302,24 @@ size_t JSTypedArray::element_size() {
   }
 }
 
+size_t JSTypedArray::LengthTrackingGsabBackedTypedArrayLength(
+    Isolate* isolate, Address raw_array) {
+  // TODO(v8:11111): Cache the last seen length in JSArrayBuffer and use it
+  // in bounds checks to minimize the need for calling this function.
+  DCHECK(FLAG_harmony_rab_gsab);
+  DisallowGarbageCollection no_gc;
+  DisallowJavascriptExecution no_js(isolate);
+  JSTypedArray array = JSTypedArray::cast(Object(raw_array));
+  CHECK(array.is_length_tracking());
+  JSArrayBuffer buffer = array.buffer();
+  CHECK(buffer.is_resizable());
+  CHECK(buffer.is_shared());
+  size_t backing_byte_length =
+      buffer.GetBackingStore()->byte_length(std::memory_order_seq_cst);
+  CHECK_GE(backing_byte_length, array.byte_offset());
+  auto element_byte_size = ElementsKindToByteSize(array.GetElementsKind());
+  return (backing_byte_length - array.byte_offset()) / element_byte_size;
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/objects/js-array-buffer.h b/chromium/v8/src/objects/js-array-buffer.h
index 3ec5e0d5177..f723380772b 100644
--- a/chromium/v8/src/objects/js-array-buffer.h
+++ b/chromium/v8/src/objects/js-array-buffer.h
@@ -77,13 +77,18 @@ class JSArrayBuffer
   // [is_asmjs_memory]: true => this buffer was once used as asm.js memory.
   DECL_BOOLEAN_ACCESSORS(is_asmjs_memory)
 
-  // [is_shared]: tells whether this is an ArrayBuffer or a SharedArrayBuffer.
+  // [is_shared]: true if this is a SharedArrayBuffer or a
+  // GrowableSharedArrayBuffer.
   DECL_BOOLEAN_ACCESSORS(is_shared)
 
+  // [is_resizable]: true if this is a ResizableArrayBuffer or a
+  // GrowableSharedArrayBuffer.
+  DECL_BOOLEAN_ACCESSORS(is_resizable)
+
   // Initializes the fields of the ArrayBuffer. The provided backing_store can
   // be nullptr. If it is not nullptr, then the function registers it with
   // src/heap/array-buffer-tracker.h.
-  V8_EXPORT_PRIVATE void Setup(SharedFlag shared,
+  V8_EXPORT_PRIVATE void Setup(SharedFlag shared, ResizableFlag resizable,
                                std::shared_ptr<BackingStore> backing_store);
 
   // Attaches the backing store to an already constructed empty ArrayBuffer.
@@ -167,7 +172,7 @@ class ArrayBufferExtension : public Malloced {
   std::atomic<GcState> young_gc_state_;
   std::shared_ptr<BackingStore> backing_store_;
   ArrayBufferExtension* next_;
-  std::size_t accounting_length_;
+  std::atomic<size_t> accounting_length_;
 
   GcState young_gc_state() {
     return young_gc_state_.load(std::memory_order_relaxed);
@@ -205,10 +210,16 @@ class ArrayBufferExtension : public Malloced {
   std::shared_ptr<BackingStore> backing_store() { return backing_store_; }
   BackingStore* backing_store_raw() { return backing_store_.get(); }
 
-  size_t accounting_length() { return accounting_length_; }
+  size_t accounting_length() {
+    return accounting_length_.load(std::memory_order_relaxed);
+  }
 
   void set_accounting_length(size_t accounting_length) {
-    accounting_length_ = accounting_length;
+    accounting_length_.store(accounting_length, std::memory_order_relaxed);
+  }
+
+  size_t ClearAccountingLength() {
+    return accounting_length_.exchange(0, std::memory_order_relaxed);
   }
 
   std::shared_ptr<BackingStore> RemoveBackingStore() {
@@ -253,6 +264,9 @@ class JSTypedArray
   // eventually.
   static constexpr size_t kMaxLength = v8::TypedArray::kMaxLength;
 
+  // Bit positions for [bit_field].
+  DEFINE_TORQUE_GENERATED_JS_TYPED_ARRAY_FLAGS()
+
   // [length]: length of typed array in elements.
   DECL_PRIMITIVE_GETTER(length, size_t)
 
@@ -265,7 +279,7 @@ class JSTypedArray
       PropertyDescriptor* desc, Maybe<ShouldThrow> should_throw);
 
   ExternalArrayType type();
-  V8_EXPORT_PRIVATE size_t element_size();
+  V8_EXPORT_PRIVATE size_t element_size() const;
 
   V8_EXPORT_PRIVATE Handle<JSArrayBuffer> GetBuffer();
 
@@ -290,6 +304,14 @@ class JSTypedArray
   inline bool is_on_heap() const;
   inline bool is_on_heap(AcquireLoadTag tag) const;
 
+  DECL_BOOLEAN_ACCESSORS(is_length_tracking)
+  DECL_BOOLEAN_ACCESSORS(is_backed_by_rab)
+  inline bool IsVariableLength() const;
+  inline size_t GetLength() const;
+
+  static size_t LengthTrackingGsabBackedTypedArrayLength(Isolate* isolate,
+                                                         Address raw_array);
+
   // Note: this is a pointer compression specific optimization.
   // Normally, on-heap typed arrays contain HeapObject value in |base_pointer|
   // field and an offset in |external_pointer|.
@@ -346,6 +368,9 @@ class JSTypedArray
   friend class Factory;
 
   DECL_PRIMITIVE_SETTER(length, size_t)
+  // Reads the "length" field, doesn't assert the TypedArray is not RAB / GSAB
+  // backed.
+  inline size_t LengthUnchecked() const;
 
   DECL_GETTER(external_pointer, Address)
   DECL_GETTER(external_pointer_raw, ExternalPointer_t)
diff --git a/chromium/v8/src/objects/js-array-buffer.tq b/chromium/v8/src/objects/js-array-buffer.tq
index 72e74cc99bd..ddd90d4c815 100644
--- a/chromium/v8/src/objects/js-array-buffer.tq
+++ b/chromium/v8/src/objects/js-array-buffer.tq
@@ -8,11 +8,13 @@ bitfield struct JSArrayBufferFlags extends uint32 {
   was_detached: bool: 1 bit;
   is_asm_js_memory: bool: 1 bit;
   is_shared: bool: 1 bit;
+  is_resizable: bool: 1 bit;
 }
 
 @generateCppClass
 extern class JSArrayBuffer extends JSObject {
   byte_length: uintptr;
+  max_byte_length: uintptr;
   backing_store: ExternalPointer;
   extension: RawPtr;
   bit_field: JSArrayBufferFlags;
@@ -29,10 +31,16 @@ macro IsDetachedBuffer(buffer: JSArrayBuffer): bool {
   return buffer.bit_field.was_detached;
 }
 
+@export
 macro IsSharedArrayBuffer(buffer: JSArrayBuffer): bool {
   return buffer.bit_field.is_shared;
 }
 
+@export
+macro IsResizableArrayBuffer(buffer: JSArrayBuffer): bool {
+  return buffer.bit_field.is_resizable;
+}
+
 @abstract
 @generateCppClass
 extern class JSArrayBufferView extends JSObject {
@@ -41,11 +49,35 @@ extern class JSArrayBufferView extends JSObject {
   byte_length: uintptr;
 }
 
+// We have 4 different TypedArrays:
+// 1) Normal (backed by AB / SAB) or non-length tracking backed by GSAB (can't
+// go oob once constructed) 2) Non-length tracking backed by RAB (can go oob
+// once constructed) 3) Length-tracking backed by RAB (JSArrayBuffer stores the
+// length) 4) Length-tracking backed by GSAB (BackingStore stores the length)
+bitfield struct JSTypedArrayFlags extends uint32 {
+  is_length_tracking: bool: 1 bit;
+  is_backed_by_rab: bool: 1 bit;
+}
+
 @generateCppClass
 extern class JSTypedArray extends JSArrayBufferView {
   length: uintptr;
   external_pointer: ExternalPointer;
   base_pointer: ByteArray|Smi;
+  bit_field: JSTypedArrayFlags;
+  // Pads header size to be a multiple of kTaggedSize.
+  @if(TAGGED_SIZE_8_BYTES) optional_padding: uint32;
+  @ifnot(TAGGED_SIZE_8_BYTES) optional_padding: void;
+}
+
+@export
+macro IsVariableLengthTypedArray(array: JSTypedArray): bool {
+  return array.bit_field.is_length_tracking || array.bit_field.is_backed_by_rab;
+}
+
+@export
+macro IsLengthTrackingTypedArray(array: JSTypedArray): bool {
+  return array.bit_field.is_length_tracking;
 }
 
 @generateCppClass
diff --git a/chromium/v8/src/objects/js-array.h b/chromium/v8/src/objects/js-array.h
index a8b336d2be9..776cb4446b4 100644
--- a/chromium/v8/src/objects/js-array.h
+++ b/chromium/v8/src/objects/js-array.h
@@ -58,8 +58,8 @@ class JSArray : public JSObject {
   // Initializes the array to a certain length.
   inline bool AllowsSetLength();
 
-  V8_EXPORT_PRIVATE static void SetLength(Handle<JSArray> array,
-                                          uint32_t length);
+  V8_EXPORT_PRIVATE static Maybe<bool> SetLength(Handle<JSArray> array,
+                                                 uint32_t length);
 
   // Set the content of the array to the content of storage.
   static inline void SetContent(Handle<JSArray> array,
diff --git a/chromium/v8/src/objects/js-function-inl.h b/chromium/v8/src/objects/js-function-inl.h
index 5c8cb5b644a..b0a53f58759 100644
--- a/chromium/v8/src/objects/js-function-inl.h
+++ b/chromium/v8/src/objects/js-function-inl.h
@@ -91,7 +91,7 @@ void JSFunction::MarkForOptimization(ConcurrencyMode mode) {
     mode = ConcurrencyMode::kNotConcurrent;
   }
 
-  DCHECK(!is_compiled() || ActiveTierIsIgnition() || ActiveTierIsNCI() ||
+  DCHECK(!is_compiled() || ActiveTierIsIgnition() ||
          ActiveTierIsMidtierTurboprop() || ActiveTierIsBaseline());
   DCHECK(!ActiveTierIsTurbofan());
   DCHECK(shared().IsInterpreted());
@@ -131,8 +131,8 @@ void JSFunction::CompleteInobjectSlackTrackingIfActive() {
   }
 }
 
-template <typename LocalIsolate>
-AbstractCode JSFunction::abstract_code(LocalIsolate* isolate) {
+template <typename IsolateT>
+AbstractCode JSFunction::abstract_code(IsolateT* isolate) {
   if (ActiveTierIsIgnition()) {
     return AbstractCode::cast(shared().GetBytecodeArray(isolate));
   } else {
@@ -206,27 +206,28 @@ void JSFunction::set_context(HeapObject value, WriteBarrierMode mode) {
   CONDITIONAL_WRITE_BARRIER(*this, kContextOffset, value, mode);
 }
 
-ACCESSORS_CHECKED(JSFunction, prototype_or_initial_map, HeapObject,
-                  kPrototypeOrInitialMapOffset, map().has_prototype_slot())
+RELEASE_ACQUIRE_ACCESSORS_CHECKED(JSFunction, prototype_or_initial_map,
+                                  HeapObject, kPrototypeOrInitialMapOffset,
+                                  map().has_prototype_slot())
 
 DEF_GETTER(JSFunction, has_prototype_slot, bool) {
   return map(cage_base).has_prototype_slot();
 }
 
 DEF_GETTER(JSFunction, initial_map, Map) {
-  return Map::cast(prototype_or_initial_map(cage_base));
+  return Map::cast(prototype_or_initial_map(cage_base, kAcquireLoad));
 }
 
 DEF_GETTER(JSFunction, has_initial_map, bool) {
   DCHECK(has_prototype_slot(cage_base));
-  return prototype_or_initial_map(cage_base).IsMap(cage_base);
+  return prototype_or_initial_map(cage_base, kAcquireLoad).IsMap(cage_base);
 }
 
 DEF_GETTER(JSFunction, has_instance_prototype, bool) {
   DCHECK(has_prototype_slot(cage_base));
   return has_initial_map(cage_base) ||
-         !prototype_or_initial_map(cage_base).IsTheHole(
-             GetReadOnlyRoots(cage_base));
+         !prototype_or_initial_map(cage_base, kAcquireLoad)
+              .IsTheHole(GetReadOnlyRoots(cage_base));
 }
 
 DEF_GETTER(JSFunction, has_prototype, bool) {
@@ -251,7 +252,7 @@ DEF_GETTER(JSFunction, instance_prototype, HeapObject) {
     return initial_map(cage_base).prototype(cage_base);
   // When there is no initial map and the prototype is a JSReceiver, the
   // initial map field is used for the prototype field.
-  return HeapObject::cast(prototype_or_initial_map(cage_base));
+  return HeapObject::cast(prototype_or_initial_map(cage_base, kAcquireLoad));
 }
 
 DEF_GETTER(JSFunction, prototype, Object) {
diff --git a/chromium/v8/src/objects/js-function.cc b/chromium/v8/src/objects/js-function.cc
index 35010be838e..b191746fae2 100644
--- a/chromium/v8/src/objects/js-function.cc
+++ b/chromium/v8/src/objects/js-function.cc
@@ -101,9 +101,6 @@ bool HighestTierOf(CodeKinds kinds, CodeKind* highest_tier) {
   } else if ((kinds & CodeKindFlag::BASELINE) != 0) {
     *highest_tier = CodeKind::BASELINE;
     return true;
-  } else if ((kinds & CodeKindFlag::NATIVE_CONTEXT_INDEPENDENT) != 0) {
-    *highest_tier = CodeKind::NATIVE_CONTEXT_INDEPENDENT;
-    return true;
   } else if ((kinds & CodeKindFlag::INTERPRETED_FUNCTION) != 0) {
     *highest_tier = CodeKind::INTERPRETED_FUNCTION;
     return true;
@@ -135,7 +132,6 @@ CodeKind JSFunction::GetActiveTier() const {
   DCHECK(highest_tier == CodeKind::TURBOFAN ||
          highest_tier == CodeKind::BASELINE ||
          highest_tier == CodeKind::TURBOPROP ||
-         highest_tier == CodeKind::NATIVE_CONTEXT_INDEPENDENT ||
          highest_tier == CodeKind::INTERPRETED_FUNCTION);
   return highest_tier;
 }
@@ -145,11 +141,6 @@ bool JSFunction::ActiveTierIsTurbofan() const {
   return GetActiveTier() == CodeKind::TURBOFAN;
 }
 
-bool JSFunction::ActiveTierIsNCI() const {
-  if (!shared().HasBytecodeArray()) return false;
-  return GetActiveTier() == CodeKind::NATIVE_CONTEXT_INDEPENDENT;
-}
-
 bool JSFunction::ActiveTierIsBaseline() const {
   return GetActiveTier() == CodeKind::BASELINE;
 }
@@ -376,7 +367,6 @@ void JSFunction::InitializeFeedbackCell(
 
   const bool needs_feedback_vector =
       !FLAG_lazy_feedback_allocation || FLAG_always_opt ||
-      function->shared().may_have_cached_code() ||
       // We also need a feedback vector for certain log events, collecting type
       // profile and more precise code coverage.
       FLAG_log_function_events || !isolate->is_best_effort_code_coverage() ||
@@ -410,7 +400,7 @@ void SetInstancePrototype(Isolate* isolate, Handle<JSFunction> function,
       // Put the value in the initial map field until an initial map is needed.
       // At that point, a new initial map is created and the prototype is put
       // into the initial map where it belongs.
-      function->set_prototype_or_initial_map(*value);
+      function->set_prototype_or_initial_map(*value, kReleaseStore);
     } else {
       Handle<Map> new_map =
           Map::Copy(isolate, initial_map, "SetInstancePrototype");
@@ -435,7 +425,7 @@ void SetInstancePrototype(Isolate* isolate, Handle<JSFunction> function,
     // Put the value in the initial map field until an initial map is
     // needed.  At that point, a new initial map is created and the
     // prototype is put into the initial map where it belongs.
-    function->set_prototype_or_initial_map(*value);
+    function->set_prototype_or_initial_map(*value, kReleaseStore);
     if (value->IsJSObject()) {
       // Optimize as prototype to detach it from its transition tree.
       JSObject::OptimizeAsPrototype(Handle<JSObject>::cast(value));
@@ -498,7 +488,7 @@ void JSFunction::SetInitialMap(Isolate* isolate, Handle<JSFunction> function,
     Map::SetPrototype(isolate, map, prototype);
   }
   map->SetConstructor(*constructor);
-  function->set_prototype_or_initial_map(*map);
+  function->set_prototype_or_initial_map(*map, kReleaseStore);
   if (FLAG_log_maps) {
     LOG(isolate, MapEvent("InitialMap", Handle<Map>(), map, "",
                           SharedFunctionInfo::DebugName(
@@ -806,6 +796,55 @@ MaybeHandle<Map> JSFunction::GetDerivedMap(Isolate* isolate,
   return map;
 }
 
+Handle<Map> JSFunction::GetDerivedRabGsabMap(Isolate* isolate,
+                                             Handle<JSFunction> constructor,
+                                             Handle<JSReceiver> new_target) {
+  {
+    DisallowHeapAllocation no_alloc;
+    NativeContext context = isolate->context().native_context();
+    if (*new_target == context.uint8_array_fun()) {
+      return handle(context.rab_gsab_uint8_array_map(), isolate);
+    }
+    if (*new_target == context.int8_array_fun()) {
+      return handle(context.rab_gsab_int8_array_map(), isolate);
+    }
+    if (*new_target == context.uint16_array_fun()) {
+      return handle(context.rab_gsab_uint16_array_map(), isolate);
+    }
+    if (*new_target == context.int16_array_fun()) {
+      return handle(context.rab_gsab_int16_array_map(), isolate);
+    }
+    if (*new_target == context.uint32_array_fun()) {
+      return handle(context.rab_gsab_uint32_array_map(), isolate);
+    }
+    if (*new_target == context.int32_array_fun()) {
+      return handle(context.rab_gsab_int32_array_map(), isolate);
+    }
+    if (*new_target == context.float32_array_fun()) {
+      return handle(context.rab_gsab_float32_array_map(), isolate);
+    }
+    if (*new_target == context.float64_array_fun()) {
+      return handle(context.rab_gsab_float64_array_map(), isolate);
+    }
+    if (*new_target == context.biguint64_array_fun()) {
+      return handle(context.rab_gsab_biguint64_array_map(), isolate);
+    }
+    if (*new_target == context.bigint64_array_fun()) {
+      return handle(context.rab_gsab_bigint64_array_map(), isolate);
+    }
+  }
+
+  // This only happens when subclassing TypedArrays. Create a new map with the
+  // corresponding RAB / GSAB ElementsKind. Note: the map is not cached and
+  // reused -> every array gets a unique map, making ICs slow.
+  Handle<Map> map =
+      GetDerivedMap(isolate, constructor, new_target).ToHandleChecked();
+  Handle<Map> rab_gsab_map = Map::Copy(isolate, map, "RAB / GSAB");
+  rab_gsab_map->set_elements_kind(
+      GetCorrespondingRabGsabElementsKind(map->elements_kind()));
+  return rab_gsab_map;
+}
+
 int JSFunction::ComputeInstanceSizeWithMinSlack(Isolate* isolate) {
   CHECK(has_initial_map());
   if (initial_map().IsInobjectSlackTrackingInProgress()) {
diff --git a/chromium/v8/src/objects/js-function.h b/chromium/v8/src/objects/js-function.h
index 76af98efe72..9d0fc533f48 100644
--- a/chromium/v8/src/objects/js-function.h
+++ b/chromium/v8/src/objects/js-function.h
@@ -55,7 +55,7 @@ class JSBoundFunction
 class JSFunction : public JSFunctionOrBoundFunction {
  public:
   // [prototype_or_initial_map]:
-  DECL_ACCESSORS(prototype_or_initial_map, HeapObject)
+  DECL_RELEASE_ACQUIRE_ACCESSORS(prototype_or_initial_map, HeapObject)
 
   // [shared]: The information about the function that
   // can be shared by instances.
@@ -93,8 +93,8 @@ class JSFunction : public JSFunctionOrBoundFunction {
 
   // Get the abstract code associated with the function, which will either be
   // a Code object or a BytecodeArray.
-  template <typename LocalIsolate>
-  inline AbstractCode abstract_code(LocalIsolate* isolate);
+  template <typename IsolateT>
+  inline AbstractCode abstract_code(IsolateT* isolate);
 
   // The predicates for querying code kinds related to this function have
   // specific terminology:
@@ -122,7 +122,6 @@ class JSFunction : public JSFunctionOrBoundFunction {
   CodeKind GetActiveTier() const;
   V8_EXPORT_PRIVATE bool ActiveTierIsIgnition() const;
   bool ActiveTierIsTurbofan() const;
-  bool ActiveTierIsNCI() const;
   bool ActiveTierIsBaseline() const;
   bool ActiveTierIsIgnitionOrBaseline() const;
   bool ActiveTierIsMidtierTurboprop() const;
@@ -238,6 +237,11 @@ class JSFunction : public JSFunctionOrBoundFunction {
       Isolate* isolate, Handle<JSFunction> constructor,
       Handle<JSReceiver> new_target);
 
+  // Like GetDerivedMap, but returns a map with a RAB / GSAB ElementsKind.
+  static V8_WARN_UNUSED_RESULT Handle<Map> GetDerivedRabGsabMap(
+      Isolate* isolate, Handle<JSFunction> constructor,
+      Handle<JSReceiver> new_target);
+
   // Get and set the prototype property on a JSFunction. If the
   // function has an initial map the prototype is set on the initial
   // map. Otherwise, the prototype is put in the initial map field
diff --git a/chromium/v8/src/objects/js-locale.cc b/chromium/v8/src/objects/js-locale.cc
index a8da4a96128..236c673ca36 100644
--- a/chromium/v8/src/objects/js-locale.cc
+++ b/chromium/v8/src/objects/js-locale.cc
@@ -20,10 +20,15 @@
 #include "src/objects/intl-objects.h"
 #include "src/objects/js-locale-inl.h"
 #include "src/objects/objects-inl.h"
+#include "unicode/calendar.h"
 #include "unicode/char16ptr.h"
+#include "unicode/coll.h"
+#include "unicode/dtptngen.h"
 #include "unicode/localebuilder.h"
 #include "unicode/locid.h"
+#include "unicode/ucal.h"
 #include "unicode/uloc.h"
+#include "unicode/ulocdata.h"
 #include "unicode/unistr.h"
 
 namespace v8 {
@@ -165,6 +170,11 @@ bool IsUnicodeVariantSubtag(const std::string& value) {
 bool IsExtensionSingleton(const std::string& value) {
   return IsAlphanum(value, 1, 1);
 }
+
+int32_t weekdayFromEDaysOfWeek(icu::Calendar::EDaysOfWeek eDaysOfWeek) {
+  return (eDaysOfWeek == icu::Calendar::SUNDAY) ? 7 : eDaysOfWeek - 1;
+}
+
 }  // namespace
 
 bool JSLocale::Is38AlphaNumList(const std::string& value) {
@@ -450,6 +460,340 @@ MaybeHandle<JSLocale> JSLocale::Minimize(Isolate* isolate,
   return Construct(isolate, result);
 }
 
+template <typename T>
+MaybeHandle<JSArray> GetKeywordValuesFromLocale(
+    Isolate* isolate, const char* key, const char* unicode_key,
+    const icu::Locale& locale,
+    const std::map<std::string, std::string>& substitutions) {
+  Factory* factory = isolate->factory();
+  UErrorCode status = U_ZERO_ERROR;
+  std::string ext =
+      locale.getUnicodeKeywordValue<std::string>(unicode_key, status);
+  if (!ext.empty()) {
+    Handle<FixedArray> fixed_array = factory->NewFixedArray(1);
+    Handle<String> str = factory->NewStringFromAsciiChecked(ext.c_str());
+    fixed_array->set(0, *str);
+    return factory->NewJSArrayWithElements(fixed_array);
+  }
+  status = U_ZERO_ERROR;
+  std::unique_ptr<icu::StringEnumeration> enumeration(
+      T::getKeywordValuesForLocale(key, locale, true, status));
+  if (U_FAILURE(status)) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSArray);
+  }
+  int32_t count = enumeration->count(status);
+  if (U_FAILURE(status)) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSArray);
+  }
+  Handle<FixedArray> fixed_array = factory->NewFixedArray(count);
+
+  int32_t index = 0;
+  for (const char* item = enumeration->next(nullptr, status);
+       U_SUCCESS(status) && item != nullptr;
+       item = enumeration->next(nullptr, status)) {
+    auto mapped = substitutions.find(item);
+    if (mapped != substitutions.end()) {
+      item = mapped->second.c_str();
+      if (*item == '\0') {
+        continue;
+      }
+    }
+    Handle<String> str = factory->NewStringFromAsciiChecked(item);
+    fixed_array->set(index++, *str);
+  }
+  if (U_FAILURE(status)) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSArray);
+  }
+  return factory->NewJSArrayWithElements(fixed_array);
+}
+
+MaybeHandle<JSArray> JSLocale::Calendars(Isolate* isolate,
+                                         Handle<JSLocale> locale) {
+  icu::Locale icu_locale(*(locale->icu_locale().raw()));
+  const std::map<std::string, std::string> substitutions(
+      {{"gregorian", "gregory"}, {"ethiopic-amete-alem", "ethioaa"}});
+  return GetKeywordValuesFromLocale<icu::Calendar>(isolate, "calendar", "ca",
+                                                   icu_locale, substitutions);
+}
+
+MaybeHandle<JSArray> JSLocale::Collations(Isolate* isolate,
+                                          Handle<JSLocale> locale) {
+  icu::Locale icu_locale(*(locale->icu_locale().raw()));
+  const std::map<std::string, std::string> substitutions(
+      {{"standard", ""}, {"search", ""}});
+  return GetKeywordValuesFromLocale<icu::Collator>(isolate, "collations", "co",
+                                                   icu_locale, substitutions);
+}
+
+MaybeHandle<JSArray> JSLocale::HourCycles(Isolate* isolate,
+                                          Handle<JSLocale> locale) {
+  // Let preferred be loc.[[HourCycle]].
+  // Let locale be loc.[[Locale]].
+  icu::Locale icu_locale(*(locale->icu_locale().raw()));
+  Factory* factory = isolate->factory();
+
+  // Assert: locale matches the unicode_locale_id production.
+
+  // Let list be a List of 1 or more hour cycle identifiers, which must be
+  // String values indicating either the 12-hour format ("h11", "h12") or the
+  // 24-hour format ("h23", "h24"), sorted in descending preference of those in
+  // common use in the locale for date and time formatting.
+
+  // Return CreateArrayFromListAndPreferred( list, preferred ).
+  Handle<FixedArray> fixed_array = factory->NewFixedArray(1);
+  UErrorCode status = U_ZERO_ERROR;
+  std::string ext =
+      icu_locale.getUnicodeKeywordValue<std::string>("hc", status);
+  if (!ext.empty()) {
+    Handle<String> str = factory->NewStringFromAsciiChecked(ext.c_str());
+    fixed_array->set(0, *str);
+    return factory->NewJSArrayWithElements(fixed_array);
+  }
+  status = U_ZERO_ERROR;
+  std::unique_ptr<icu::DateTimePatternGenerator> generator(
+      icu::DateTimePatternGenerator::createInstance(icu_locale, status));
+  if (U_FAILURE(status)) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSArray);
+  }
+
+  UDateFormatHourCycle hc = generator->getDefaultHourCycle(status);
+  if (U_FAILURE(status)) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSArray);
+  }
+  Handle<String> hour_cycle;
+
+  switch (hc) {
+    case UDAT_HOUR_CYCLE_11:
+      hour_cycle = factory->h11_string();
+      break;
+    case UDAT_HOUR_CYCLE_12:
+      hour_cycle = factory->h12_string();
+      break;
+    case UDAT_HOUR_CYCLE_23:
+      hour_cycle = factory->h23_string();
+      break;
+    case UDAT_HOUR_CYCLE_24:
+      hour_cycle = factory->h24_string();
+      break;
+    default:
+      break;
+  }
+  fixed_array->set(0, *hour_cycle);
+  return factory->NewJSArrayWithElements(fixed_array);
+}
+
+MaybeHandle<JSArray> JSLocale::NumberingSystems(Isolate* isolate,
+                                                Handle<JSLocale> locale) {
+  // Let preferred be loc.[[NumberingSystem]].
+
+  // Let locale be loc.[[Locale]].
+  icu::Locale icu_locale(*(locale->icu_locale().raw()));
+  Factory* factory = isolate->factory();
+
+  // Assert: locale matches the unicode_locale_id production.
+
+  // Let list be a List of 1 or more numbering system identifiers, which must be
+  // String values conforming to the type sequence from UTS 35 Unicode Locale
+  // Identifier, section 3.2, sorted in descending preference of those in common
+  // use in the locale for formatting numeric values.
+
+  // Return CreateArrayFromListAndPreferred( list, preferred ).
+  UErrorCode status = U_ZERO_ERROR;
+  Handle<FixedArray> fixed_array = factory->NewFixedArray(1);
+  std::string numbering_system =
+      icu_locale.getUnicodeKeywordValue<std::string>("nu", status);
+  if (numbering_system.empty()) {
+    numbering_system = Intl::GetNumberingSystem(icu_locale);
+  }
+  Handle<String> str =
+      factory->NewStringFromAsciiChecked(numbering_system.c_str());
+
+  fixed_array->set(0, *str);
+  return factory->NewJSArrayWithElements(fixed_array);
+}
+
+MaybeHandle<Object> JSLocale::TimeZones(Isolate* isolate,
+                                        Handle<JSLocale> locale) {
+  // Let loc be the this value.
+
+  // Perform ? RequireInternalSlot(loc, [[InitializedLocale]])
+
+  // Let locale be loc.[[Locale]].
+  icu::Locale icu_locale(*(locale->icu_locale().raw()));
+  Factory* factory = isolate->factory();
+
+  // If the unicode_language_id production of locale does not contain the
+  // ["-" unicode_region_subtag] sequence, return undefined.
+  const char* region = icu_locale.getCountry();
+  if (region == nullptr || strlen(region) == 0) {
+    return factory->undefined_value();
+  }
+
+  // Return TimeZonesOfLocale(loc).
+
+  // Let locale be loc.[[Locale]].
+
+  // Assert: locale matches the unicode_locale_id production.
+
+  // Let region be the substring of locale corresponding to the
+  // unicode_region_subtag production of the unicode_language_id.
+
+  // Let list be a List of 1 or more time zone identifiers, which must be String
+  // values indicating a Zone or Link name of the IANA Time Zone Database,
+  // sorted in descending preference of those in common use in region.
+  int32_t index = 0;
+  UErrorCode status = U_ZERO_ERROR;
+  std::unique_ptr<icu::StringEnumeration> enumeration(
+      icu::TimeZone::createTimeZoneIDEnumeration(UCAL_ZONE_TYPE_CANONICAL,
+                                                 region, nullptr, status));
+  if (U_FAILURE(status)) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSArray);
+  }
+  int32_t count = enumeration->count(status);
+  if (U_FAILURE(status)) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSArray);
+  }
+
+  // Return CreateArrayFromList( list ).
+  Handle<FixedArray> fixed_array = factory->NewFixedArray(count);
+  for (const char* item = enumeration->next(nullptr, status);
+       U_SUCCESS(status) && item != nullptr;
+       item = enumeration->next(nullptr, status)) {
+    Handle<String> str = isolate->factory()->NewStringFromAsciiChecked(item);
+    fixed_array->set(index++, *str);
+  }
+  if (U_FAILURE(status)) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSArray);
+  }
+
+  return factory->NewJSArrayWithElements(fixed_array);
+}
+
+MaybeHandle<JSObject> JSLocale::TextInfo(Isolate* isolate,
+                                         Handle<JSLocale> locale) {
+  // Let loc be the this value.
+
+  // Perform ? RequireInternalSlot(loc, [[InitializedLocale]]).
+
+  // Let locale be loc.[[Locale]].
+
+  // Assert: locale matches the unicode_locale_id production.
+
+  Factory* factory = isolate->factory();
+  // Let info be ! ObjectCreate(%Object.prototype%).
+  Handle<JSObject> info = factory->NewJSObject(isolate->object_function());
+
+  // Let dir be "ltr".
+  Handle<String> dir = factory->ltr_string();
+
+  // If the default general ordering of characters (characterOrder) within a
+  // line in the locale is right-to-left, then
+  UErrorCode status = U_ZERO_ERROR;
+  ULayoutType orientation = uloc_getCharacterOrientation(
+      (locale->icu_locale().raw())->getName(), &status);
+  if (U_FAILURE(status)) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSObject);
+  }
+  if (orientation == ULOC_LAYOUT_LTR) {
+    // Let dir be "rtl".
+    dir = factory->rtl_string();
+  }
+
+  // Perform ! CreateDataPropertyOrThrow(info, "direction", dir).
+  CHECK(JSReceiver::CreateDataProperty(
+            isolate, info, factory->direction_string(), dir, Just(kDontThrow))
+            .FromJust());
+
+  // Return info.
+  return info;
+}
+
+MaybeHandle<JSObject> JSLocale::WeekInfo(Isolate* isolate,
+                                         Handle<JSLocale> locale) {
+  // Let loc be the this value.
+
+  // Perform ? RequireInternalSlot(loc, [[InitializedLocale]]).
+
+  // Let locale be loc.[[Locale]].
+
+  // Assert: locale matches the unicode_locale_id production.
+  Factory* factory = isolate->factory();
+
+  // Let info be ! ObjectCreate(%Object.prototype%).
+  Handle<JSObject> info = factory->NewJSObject(isolate->object_function());
+  UErrorCode status = U_ZERO_ERROR;
+  std::unique_ptr<icu::Calendar> calendar(
+      icu::Calendar::createInstance(*(locale->icu_locale().raw()), status));
+  if (U_FAILURE(status)) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSObject);
+  }
+
+  // Let fd be the weekday value indicating which day of the week is considered
+  // the 'first' day, for calendar purposes, in the locale.
+  int32_t fd = weekdayFromEDaysOfWeek(calendar->getFirstDayOfWeek());
+  bool thursday_is_weekend =
+      (UCAL_WEEKDAY != calendar->getDayOfWeekType(UCAL_THURSDAY, status));
+  bool friday_is_weekend =
+      (UCAL_WEEKDAY != calendar->getDayOfWeekType(UCAL_FRIDAY, status));
+  bool saturday_is_weekend =
+      (UCAL_WEEKDAY != calendar->getDayOfWeekType(UCAL_SATURDAY, status));
+  bool sunday_is_weekend =
+      (UCAL_WEEKDAY != calendar->getDayOfWeekType(UCAL_SUNDAY, status));
+  if (U_FAILURE(status)) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSObject);
+  }
+
+  // Let ws be the weekday value indicating which day of the week is considered
+  // the starting day of the 'weekend', for calendar purposes, in the locale.
+  int32_t ws = thursday_is_weekend ? 4 : (friday_is_weekend ? 5 : 6);
+
+  // Let we be the weekday value indicating which day of the week is considered
+  // the ending day of the 'weekend', for calendar purposes, in the locale.
+  int32_t we = sunday_is_weekend ? 7 : (saturday_is_weekend ? 6 : 5);
+
+  // Let md be the minimal days required in the first week of a month or year,
+  // for calendar purposes, in the locale.
+  int32_t md = calendar->getMinimalDaysInFirstWeek();
+
+  // Perform ! CreateDataPropertyOrThrow(info, "firstDay", fd).
+  CHECK(JSReceiver::CreateDataProperty(
+            isolate, info, factory->firstDay_string(),
+            factory->NewNumberFromInt(fd), Just(kDontThrow))
+            .FromJust());
+
+  // Perform ! CreateDataPropertyOrThrow(info, "weekendStart", ws).
+  CHECK(JSReceiver::CreateDataProperty(
+            isolate, info, factory->weekendStart_string(),
+            factory->NewNumberFromInt(ws), Just(kDontThrow))
+            .FromJust());
+
+  // Perform ! CreateDataPropertyOrThrow(info, "weekendEnd", we).
+  CHECK(JSReceiver::CreateDataProperty(
+            isolate, info, factory->weekendEnd_string(),
+            factory->NewNumberFromInt(we), Just(kDontThrow))
+            .FromJust());
+
+  // Perform ! CreateDataPropertyOrThrow(info, "minimalDays", md).
+  CHECK(JSReceiver::CreateDataProperty(
+            isolate, info, factory->minimalDays_string(),
+            factory->NewNumberFromInt(md), Just(kDontThrow))
+            .FromJust());
+
+  // Return info.
+  return info;
+}
+
 Handle<Object> JSLocale::Language(Isolate* isolate, Handle<JSLocale> locale) {
   Factory* factory = isolate->factory();
   const char* language = locale->icu_locale().raw()->getLanguage();
diff --git a/chromium/v8/src/objects/js-locale.h b/chromium/v8/src/objects/js-locale.h
index d864c8272f5..5f57dca5169 100644
--- a/chromium/v8/src/objects/js-locale.h
+++ b/chromium/v8/src/objects/js-locale.h
@@ -40,6 +40,21 @@ class JSLocale : public TorqueGeneratedJSLocale<JSLocale, JSObject> {
   static MaybeHandle<JSLocale> Minimize(Isolate* isolate,
                                         Handle<JSLocale> locale);
 
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSArray> Calendars(
+      Isolate* isolate, Handle<JSLocale> locale);
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSArray> Collations(
+      Isolate* isolate, Handle<JSLocale> locale);
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSArray> HourCycles(
+      Isolate* isolate, Handle<JSLocale> locale);
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSArray> NumberingSystems(
+      Isolate* isolate, Handle<JSLocale> locale);
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSObject> TextInfo(
+      Isolate* isolate, Handle<JSLocale> locale);
+  V8_WARN_UNUSED_RESULT static MaybeHandle<Object> TimeZones(
+      Isolate* isolate, Handle<JSLocale> locale);
+  V8_WARN_UNUSED_RESULT static MaybeHandle<JSObject> WeekInfo(
+      Isolate* isolate, Handle<JSLocale> locale);
+
   static Handle<Object> Language(Isolate* isolate, Handle<JSLocale> locale);
   static Handle<Object> Script(Isolate* isolate, Handle<JSLocale> locale);
   static Handle<Object> Region(Isolate* isolate, Handle<JSLocale> locale);
diff --git a/chromium/v8/src/objects/js-objects-inl.h b/chromium/v8/src/objects/js-objects-inl.h
index cbbbc9fc9ec..6d3dc9cdde4 100644
--- a/chromium/v8/src/objects/js-objects-inl.h
+++ b/chromium/v8/src/objects/js-objects-inl.h
@@ -401,25 +401,31 @@ Object JSObject::InObjectPropertyAtPut(int index, Object value,
 }
 
 void JSObject::InitializeBody(Map map, int start_offset,
-                              Object pre_allocated_value, Object filler_value) {
-  DCHECK_IMPLIES(filler_value.IsHeapObject(),
-                 !ObjectInYoungGeneration(filler_value));
-  DCHECK_IMPLIES(pre_allocated_value.IsHeapObject(),
-                 !ObjectInYoungGeneration(pre_allocated_value));
+                              bool is_slack_tracking_in_progress,
+                              MapWord filler_map, Object undefined_filler) {
   int size = map.instance_size();
   int offset = start_offset;
-  if (filler_value != pre_allocated_value) {
+  if (is_slack_tracking_in_progress) {
     int end_of_pre_allocated_offset =
         size - (map.UnusedPropertyFields() * kTaggedSize);
     DCHECK_LE(kHeaderSize, end_of_pre_allocated_offset);
+    // fill start with references to the undefined value object
     while (offset < end_of_pre_allocated_offset) {
-      WRITE_FIELD(*this, offset, pre_allocated_value);
+      WRITE_FIELD(*this, offset, undefined_filler);
+      offset += kTaggedSize;
+    }
+    // fill the remainder with one word filler objects (ie just a map word)
+    while (offset < size) {
+      Object fm = Object(filler_map.ptr());
+      WRITE_FIELD(*this, offset, fm);
+      offset += kTaggedSize;
+    }
+  } else {
+    while (offset < size) {
+      // fill with references to the undefined value object
+      WRITE_FIELD(*this, offset, undefined_filler);
       offset += kTaggedSize;
     }
-  }
-  while (offset < size) {
-    WRITE_FIELD(*this, offset, filler_value);
-    offset += kTaggedSize;
   }
 }
 
@@ -769,7 +775,6 @@ static inline bool ShouldConvertToSlowElements(JSObject object,
   if (index - capacity >= JSObject::kMaxGap) return true;
   *new_capacity = JSObject::NewElementsCapacity(index + 1);
   DCHECK_LT(index, *new_capacity);
-  // TODO(ulan): Check if it works with young large objects.
   if (*new_capacity <= JSObject::kMaxUncheckedOldFastElementsLength ||
       (*new_capacity <= JSObject::kMaxUncheckedFastElementsLength &&
        ObjectInYoungGeneration(object))) {
diff --git a/chromium/v8/src/objects/js-objects.cc b/chromium/v8/src/objects/js-objects.cc
index 01df8e1524f..032296aaa48 100644
--- a/chromium/v8/src/objects/js-objects.cc
+++ b/chromium/v8/src/objects/js-objects.cc
@@ -2054,8 +2054,7 @@ MaybeHandle<FixedArray> GetOwnValuesOrEntries(Isolate* isolate,
         MaybeHandle<FixedArray>());
 
     if (get_entries) {
-      Handle<FixedArray> entry_storage =
-          isolate->factory()->NewUninitializedFixedArray(2);
+      Handle<FixedArray> entry_storage = isolate->factory()->NewFixedArray(2);
       entry_storage->set(0, *key);
       entry_storage->set(1, *value);
       value = isolate->factory()->NewJSArrayWithElements(entry_storage,
@@ -2767,14 +2766,14 @@ void MigrateFastToFast(Isolate* isolate, Handle<JSObject> object,
     // If the map does not add named properties, simply set the map.
     if (old_map->NumberOfOwnDescriptors() ==
         new_map->NumberOfOwnDescriptors()) {
-      object->synchronized_set_map(*new_map);
+      object->set_map(*new_map, kReleaseStore);
       return;
     }
 
     // If the map adds a new kDescriptor property, simply set the map.
     PropertyDetails details = new_map->GetLastDescriptorDetails(isolate);
     if (details.location() == kDescriptor) {
-      object->synchronized_set_map(*new_map);
+      object->set_map(*new_map, kReleaseStore);
       return;
     }
 
@@ -2790,7 +2789,7 @@ void MigrateFastToFast(Isolate* isolate, Handle<JSObject> object,
         auto value = isolate->factory()->NewHeapNumberWithHoleNaN();
         object->FastPropertyAtPut(index, *value);
       }
-      object->synchronized_set_map(*new_map);
+      object->set_map(*new_map, kReleaseStore);
       return;
     }
 
@@ -2818,7 +2817,7 @@ void MigrateFastToFast(Isolate* isolate, Handle<JSObject> object,
 
     // Set the new property value and do the map transition.
     object->SetProperties(*new_storage);
-    object->synchronized_set_map(*new_map);
+    object->set_map(*new_map, kReleaseStore);
     return;
   }
 
@@ -2831,7 +2830,7 @@ void MigrateFastToFast(Isolate* isolate, Handle<JSObject> object,
   // converted to doubles.
   if (!old_map->InstancesNeedRewriting(*new_map, number_of_fields, inobject,
                                        unused, &old_number_of_fields)) {
-    object->synchronized_set_map(*new_map);
+    object->set_map(*new_map, kReleaseStore);
     return;
   }
 
@@ -2946,7 +2945,7 @@ void MigrateFastToFast(Isolate* isolate, Handle<JSObject> object,
 
   // We are storing the new map using release store after creating a filler for
   // the left-over space to avoid races with the sweeper thread.
-  object->synchronized_set_map(*new_map);
+  object->set_map(*new_map, kReleaseStore);
 }
 
 void MigrateFastToSlow(Isolate* isolate, Handle<JSObject> object,
@@ -3044,7 +3043,7 @@ void MigrateFastToSlow(Isolate* isolate, Handle<JSObject> object,
 
   // We are storing the new map using release store after creating a filler for
   // the left-over space to avoid races with the sweeper thread.
-  object->synchronized_set_map(*new_map);
+  object->set_map(*new_map, kReleaseStore);
 
   if (V8_ENABLE_SWISS_NAME_DICTIONARY_BOOL) {
     object->SetProperties(*ord_dictionary);
@@ -3088,7 +3087,7 @@ void JSObject::MigrateToMap(Isolate* isolate, Handle<JSObject> object,
     CHECK(new_map->is_dictionary_map());
 
     // Slow-to-slow migration is trivial.
-    object->synchronized_set_map(*new_map);
+    object->set_map(*new_map, kReleaseStore);
   } else if (!new_map->is_dictionary_map()) {
     MigrateFastToFast(isolate, object, new_map);
     if (old_map->is_prototype_map()) {
@@ -3118,10 +3117,9 @@ void JSObject::MigrateToMap(Isolate* isolate, Handle<JSObject> object,
   // When adding code here, add a DisallowGarbageCollection too.
 }
 
-void JSObject::ForceSetPrototype(Handle<JSObject> object,
+void JSObject::ForceSetPrototype(Isolate* isolate, Handle<JSObject> object,
                                  Handle<HeapObject> proto) {
   // object.__proto__ = proto;
-  Isolate* isolate = object->GetIsolate();
   Handle<Map> old_map = Handle<Map>(object->map(), isolate);
   Handle<Map> new_map = Map::Copy(isolate, old_map, "ForceSetPrototype");
   Map::SetPrototype(isolate, new_map, proto);
@@ -3199,7 +3197,7 @@ void JSObject::AllocateStorageForMap(Handle<JSObject> object, Handle<Map> map) {
     Object value = storage->get(i);
     object->FastPropertyAtPut(index, value);
   }
-  object->synchronized_set_map(*map);
+  object->set_map(*map, kReleaseStore);
 }
 
 void JSObject::MigrateInstance(Isolate* isolate, Handle<JSObject> object) {
@@ -3489,7 +3487,7 @@ void JSObject::MigrateSlowToFast(Handle<JSObject> object,
     DCHECK_LE(unused_property_fields, inobject_props);
     // Transform the object.
     new_map->SetInObjectUnusedPropertyFields(inobject_props);
-    object->synchronized_set_map(*new_map);
+    object->set_map(*new_map, kReleaseStore);
     object->SetProperties(ReadOnlyRoots(isolate).empty_fixed_array());
     // Check that it really works.
     DCHECK(object->HasFastProperties());
@@ -3608,7 +3606,7 @@ void JSObject::MigrateSlowToFast(Handle<JSObject> object,
     LOG(isolate, MapEvent("SlowToFast", old_map, new_map, reason));
   }
   // Transform the object.
-  object->synchronized_set_map(*new_map);
+  object->set_map(*new_map, kReleaseStore);
 
   object->SetProperties(*fields);
   DCHECK(object->IsJSObject());
@@ -4222,10 +4220,15 @@ bool JSObject::HasEnumerableElements() {
     }
 #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) case TYPE##_ELEMENTS:
 
-      TYPED_ARRAYS(TYPED_ARRAY_CASE)
+      TYPED_ARRAYS(TYPED_ARRAY_CASE) {
+        size_t length = JSTypedArray::cast(object).length();
+        return length > 0;
+      }
+
+      RAB_GSAB_TYPED_ARRAYS(TYPED_ARRAY_CASE)
 #undef TYPED_ARRAY_CASE
       {
-        size_t length = JSTypedArray::cast(object).length();
+        size_t length = JSTypedArray::cast(object).GetLength();
         return length > 0;
       }
     case DICTIONARY_ELEMENTS: {
@@ -4769,7 +4772,7 @@ void JSObject::SetImmutableProto(Handle<JSObject> object) {
 
   Handle<Map> new_map =
       Map::TransitionToImmutableProto(object->GetIsolate(), map);
-  object->synchronized_set_map(*new_map);
+  object->set_map(*new_map, kReleaseStore);
 }
 
 void JSObject::EnsureCanContainElements(Handle<JSObject> object,
@@ -4851,9 +4854,9 @@ static ElementsKind BestFittingFastElementsKind(JSObject object) {
 }
 
 // static
-void JSObject::AddDataElement(Handle<JSObject> object, uint32_t index,
-                              Handle<Object> value,
-                              PropertyAttributes attributes) {
+Maybe<bool> JSObject::AddDataElement(Handle<JSObject> object, uint32_t index,
+                                     Handle<Object> value,
+                                     PropertyAttributes attributes) {
   Isolate* isolate = object->GetIsolate();
 
   DCHECK(object->map(isolate).is_extensible());
@@ -4896,13 +4899,15 @@ void JSObject::AddDataElement(Handle<JSObject> object, uint32_t index,
   }
   to = GetMoreGeneralElementsKind(kind, to);
   ElementsAccessor* accessor = ElementsAccessor::ForKind(to);
-  accessor->Add(object, index, value, attributes, new_capacity);
+  MAYBE_RETURN(accessor->Add(object, index, value, attributes, new_capacity),
+               Nothing<bool>());
 
   if (object->IsJSArray(isolate) && index >= old_length) {
     Handle<Object> new_length =
         isolate->factory()->NewNumberFromUint(index + 1);
     JSArray::cast(*object).set_length(*new_length);
   }
+  return Just(true);
 }
 
 template <AllocationSiteUpdateMode update_or_check>
@@ -4969,7 +4974,15 @@ void JSObject::TransitionElementsKind(Handle<JSObject> object,
     DCHECK((IsSmiElementsKind(from_kind) && IsDoubleElementsKind(to_kind)) ||
            (IsDoubleElementsKind(from_kind) && IsObjectElementsKind(to_kind)));
     uint32_t c = static_cast<uint32_t>(object->elements().length());
-    ElementsAccessor::ForKind(to_kind)->GrowCapacityAndConvert(object, c);
+    if (ElementsAccessor::ForKind(to_kind)
+            ->GrowCapacityAndConvert(object, c)
+            .IsNothing()) {
+      // TODO(victorgomes): Temporarily forcing a fatal error here in case of
+      // overflow, until all users of TransitionElementsKind can handle
+      // exceptions.
+      FATAL("Fatal JavaScript invalid array size transitioning elements kind.");
+      UNREACHABLE();
+    }
   }
 }
 
@@ -5017,6 +5030,7 @@ int JSObject::GetFastElementsUsage() {
 #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) case TYPE##_ELEMENTS:
 
       TYPED_ARRAYS(TYPED_ARRAY_CASE)
+      RAB_GSAB_TYPED_ARRAYS(TYPED_ARRAY_CASE)
 #undef TYPED_ARRAY_CASE
       UNREACHABLE();
   }
diff --git a/chromium/v8/src/objects/js-objects.h b/chromium/v8/src/objects/js-objects.h
index b1f22ed8f6f..2e94bf17a95 100644
--- a/chromium/v8/src/objects/js-objects.h
+++ b/chromium/v8/src/objects/js-objects.h
@@ -440,10 +440,9 @@ class JSObject : public TorqueGeneratedJSObject<JSObject, JSReceiver> {
                           const char* name, Handle<Object> value,
                           PropertyAttributes attributes);
 
-  V8_EXPORT_PRIVATE static void AddDataElement(Handle<JSObject> receiver,
-                                               uint32_t index,
-                                               Handle<Object> value,
-                                               PropertyAttributes attributes);
+  V8_EXPORT_PRIVATE static Maybe<bool> AddDataElement(
+      Handle<JSObject> receiver, uint32_t index, Handle<Object> value,
+      PropertyAttributes attributes);
 
   // Extend the receiver with a single fast property appeared first in the
   // passed map. This also extends the property backing store if necessary.
@@ -620,7 +619,7 @@ class JSObject : public TorqueGeneratedJSObject<JSObject, JSReceiver> {
 
   // Forces a prototype without any of the checks that the regular SetPrototype
   // would do.
-  static void ForceSetPrototype(Handle<JSObject> object,
+  static void ForceSetPrototype(Isolate* isolate, Handle<JSObject> object,
                                 Handle<HeapObject> proto);
 
   // Convert the object to use the canonical dictionary
@@ -680,11 +679,12 @@ class JSObject : public TorqueGeneratedJSObject<JSObject, JSReceiver> {
 
   // Initializes the body starting at |start_offset|. It is responsibility of
   // the caller to initialize object header. Fill the pre-allocated fields with
-  // pre_allocated_value and the rest with filler_value.
+  // undefined_value and the rest with filler_map.
   // Note: this call does not update write barrier, the caller is responsible
-  // to ensure that |filler_value| can be collected without WB here.
+  // to ensure that |filler_map| can be collected without WB here.
   inline void InitializeBody(Map map, int start_offset,
-                             Object pre_allocated_value, Object filler_value);
+                             bool is_slack_tracking_in_progress,
+                             MapWord filler_map, Object undefined_value);
 
   // Check whether this object references another object
   bool ReferencesObject(Object obj);
@@ -702,11 +702,11 @@ class JSObject : public TorqueGeneratedJSObject<JSObject, JSReceiver> {
   DECL_PRINTER(JSObject)
   DECL_VERIFIER(JSObject)
 #ifdef OBJECT_PRINT
-  bool PrintProperties(std::ostream& os);  // NOLINT
-  void PrintElements(std::ostream& os);    // NOLINT
+  bool PrintProperties(std::ostream& os);
+  void PrintElements(std::ostream& os);
 #endif
 #if defined(DEBUG) || defined(OBJECT_PRINT)
-  void PrintTransitions(std::ostream& os);  // NOLINT
+  void PrintTransitions(std::ostream& os);
 #endif
 
   static void PrintElementsTransition(FILE* file, Handle<JSObject> object,
diff --git a/chromium/v8/src/objects/js-objects.tq b/chromium/v8/src/objects/js-objects.tq
index 9f5bf8554e9..e21f874bbb6 100644
--- a/chromium/v8/src/objects/js-objects.tq
+++ b/chromium/v8/src/objects/js-objects.tq
@@ -67,10 +67,15 @@ macro GetDerivedMap(implicit context: Context)(
 
     return map;
   } label SlowPath {
-    return runtime::GetDerivedMap(context, target, newTarget);
+    return runtime::GetDerivedMap(context, target, newTarget, FalseConstant());
   }
 }
 
+macro GetDerivedRabGsabMap(implicit context: Context)(
+    target: JSFunction, newTarget: JSReceiver): Map {
+  return runtime::GetDerivedMap(context, target, newTarget, TrueConstant());
+}
+
 macro AllocateFastOrSlowJSObjectFromMap(implicit context: Context)(map: Map):
     JSObject {
   let properties: EmptyFixedArray|NameDictionary|SwissNameDictionary =
diff --git a/chromium/v8/src/objects/js-regexp.cc b/chromium/v8/src/objects/js-regexp.cc
index b8a01418dae..0ae91a5ef91 100644
--- a/chromium/v8/src/objects/js-regexp.cc
+++ b/chromium/v8/src/objects/js-regexp.cc
@@ -151,6 +151,27 @@ JSRegExp::Flags JSRegExp::FlagsFromString(Isolate* isolate,
 }
 
 // static
+Handle<String> JSRegExp::StringFromFlags(Isolate* isolate,
+                                         JSRegExp::Flags flags) {
+  // Ensure that this function is up-to-date with the supported flag options.
+  constexpr size_t kFlagCount = JSRegExp::kFlagCount;
+  STATIC_ASSERT(kFlagCount == 8);
+
+  // Translate to the lexicographically smaller string.
+  int cursor = 0;
+  char buffer[kFlagCount] = {'\0'};
+  if (flags & JSRegExp::kHasIndices) buffer[cursor++] = 'd';
+  if (flags & JSRegExp::kGlobal) buffer[cursor++] = 'g';
+  if (flags & JSRegExp::kIgnoreCase) buffer[cursor++] = 'i';
+  if (flags & JSRegExp::kLinear) buffer[cursor++] = 'l';
+  if (flags & JSRegExp::kMultiline) buffer[cursor++] = 'm';
+  if (flags & JSRegExp::kDotAll) buffer[cursor++] = 's';
+  if (flags & JSRegExp::kUnicode) buffer[cursor++] = 'u';
+  if (flags & JSRegExp::kSticky) buffer[cursor++] = 'y';
+  return isolate->factory()->NewStringFromAsciiChecked(buffer);
+}
+
+// static
 MaybeHandle<JSRegExp> JSRegExp::New(Isolate* isolate, Handle<String> pattern,
                                     Flags flags, uint32_t backtrack_limit) {
   Handle<JSFunction> constructor = isolate->regexp_function();
diff --git a/chromium/v8/src/objects/js-regexp.h b/chromium/v8/src/objects/js-regexp.h
index c23662251a4..d66912c9e85 100644
--- a/chromium/v8/src/objects/js-regexp.h
+++ b/chromium/v8/src/objects/js-regexp.h
@@ -90,6 +90,9 @@ class JSRegExp : public TorqueGeneratedJSRegExp<JSRegExp, JSObject> {
   static Flags FlagsFromString(Isolate* isolate, Handle<String> flags,
                                bool* success);
 
+  V8_EXPORT_PRIVATE static Handle<String> StringFromFlags(Isolate* isolate,
+                                                          Flags flags);
+
   bool CanTierUp();
   bool MarkedForTierUp();
   void ResetLastTierUpTick();
diff --git a/chromium/v8/src/objects/literal-objects.cc b/chromium/v8/src/objects/literal-objects.cc
index 8dfea9f77c1..e6d57de82e2 100644
--- a/chromium/v8/src/objects/literal-objects.cc
+++ b/chromium/v8/src/objects/literal-objects.cc
@@ -37,9 +37,9 @@ inline int EncodeComputedEntry(ClassBoilerplate::ValueKind value_kind,
   return flags;
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 void AddToDescriptorArrayTemplate(
-    LocalIsolate* isolate, Handle<DescriptorArray> descriptor_array_template,
+    IsolateT* isolate, Handle<DescriptorArray> descriptor_array_template,
     Handle<Name> name, ClassBoilerplate::ValueKind value_kind,
     Handle<Object> value) {
   InternalIndex entry = descriptor_array_template->Search(
@@ -90,18 +90,18 @@ void AddToDescriptorArrayTemplate(
   }
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<NameDictionary> DictionaryAddNoUpdateNextEnumerationIndex(
-    LocalIsolate* isolate, Handle<NameDictionary> dictionary, Handle<Name> name,
+    IsolateT* isolate, Handle<NameDictionary> dictionary, Handle<Name> name,
     Handle<Object> value, PropertyDetails details,
     InternalIndex* entry_out = nullptr) {
   return NameDictionary::AddNoUpdateNextEnumerationIndex(
       isolate, dictionary, name, value, details, entry_out);
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<SwissNameDictionary> DictionaryAddNoUpdateNextEnumerationIndex(
-    LocalIsolate* isolate, Handle<SwissNameDictionary> dictionary,
+    IsolateT* isolate, Handle<SwissNameDictionary> dictionary,
     Handle<Name> name, Handle<Object> value, PropertyDetails details,
     InternalIndex* entry_out = nullptr) {
   // SwissNameDictionary does not maintain the enumeration order in property
@@ -109,10 +109,10 @@ Handle<SwissNameDictionary> DictionaryAddNoUpdateNextEnumerationIndex(
   return SwissNameDictionary::Add(isolate, dictionary, name, value, details);
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<NumberDictionary> DictionaryAddNoUpdateNextEnumerationIndex(
-    LocalIsolate* isolate, Handle<NumberDictionary> dictionary,
-    uint32_t element, Handle<Object> value, PropertyDetails details,
+    IsolateT* isolate, Handle<NumberDictionary> dictionary, uint32_t element,
+    Handle<Object> value, PropertyDetails details,
     InternalIndex* entry_out = nullptr) {
   // NumberDictionary does not maintain the enumeration order, so it's
   // a normal Add().
@@ -149,10 +149,9 @@ inline int GetExistingValueIndex(Object value) {
   return value.IsSmi() ? Smi::ToInt(value) : kAccessorNotDefined;
 }
 
-template <typename LocalIsolate, typename Dictionary, typename Key>
-void AddToDictionaryTemplate(LocalIsolate* isolate,
-                             Handle<Dictionary> dictionary, Key key,
-                             int key_index,
+template <typename IsolateT, typename Dictionary, typename Key>
+void AddToDictionaryTemplate(IsolateT* isolate, Handle<Dictionary> dictionary,
+                             Key key, int key_index,
                              ClassBoilerplate::ValueKind value_kind,
                              Smi value) {
   InternalIndex entry = dictionary->FindEntry(isolate, key);
@@ -372,7 +371,7 @@ void AddToDictionaryTemplate(LocalIsolate* isolate,
 
 // Helper class that eases building of a properties, elements and computed
 // properties templates.
-template <typename LocalIsolate>
+template <typename IsolateT>
 class ObjectDescriptor {
  public:
   void IncComputedCount() { ++computed_count_; }
@@ -401,7 +400,7 @@ class ObjectDescriptor {
     return computed_properties_;
   }
 
-  void CreateTemplates(LocalIsolate* isolate) {
+  void CreateTemplates(IsolateT* isolate) {
     auto* factory = isolate->factory();
     descriptor_array_template_ = factory->empty_descriptor_array();
     if (V8_ENABLE_SWISS_NAME_DICTIONARY_BOOL) {
@@ -443,8 +442,8 @@ class ObjectDescriptor {
     temp_handle_ = handle(Smi::zero(), isolate);
   }
 
-  void AddConstant(LocalIsolate* isolate, Handle<Name> name,
-                   Handle<Object> value, PropertyAttributes attribs) {
+  void AddConstant(IsolateT* isolate, Handle<Name> name, Handle<Object> value,
+                   PropertyAttributes attribs) {
     bool is_accessor = value->IsAccessorInfo();
     DCHECK(!value->IsAccessorPair());
     if (HasDictionaryProperties()) {
@@ -473,7 +472,7 @@ class ObjectDescriptor {
     }
   }
 
-  void AddNamedProperty(LocalIsolate* isolate, Handle<Name> name,
+  void AddNamedProperty(IsolateT* isolate, Handle<Name> name,
                         ClassBoilerplate::ValueKind value_kind,
                         int value_index) {
     Smi value = Smi::FromInt(value_index);
@@ -494,7 +493,7 @@ class ObjectDescriptor {
     }
   }
 
-  void AddIndexedProperty(LocalIsolate* isolate, uint32_t element,
+  void AddIndexedProperty(IsolateT* isolate, uint32_t element,
                           ClassBoilerplate::ValueKind value_kind,
                           int value_index) {
     Smi value = Smi::FromInt(value_index);
@@ -516,7 +515,7 @@ class ObjectDescriptor {
     next_enumeration_index_ = current_index + 1;
   }
 
-  void Finalize(LocalIsolate* isolate) {
+  void Finalize(IsolateT* isolate) {
     if (HasDictionaryProperties()) {
       DCHECK_EQ(current_computed_index_, computed_properties_->length());
       if (!V8_ENABLE_SWISS_NAME_DICTIONARY_BOOL) {
@@ -555,9 +554,9 @@ class ObjectDescriptor {
   Handle<Object> temp_handle_;
 };
 
-template <typename LocalIsolate, typename PropertyDict>
+template <typename IsolateT, typename PropertyDict>
 void ClassBoilerplate::AddToPropertiesTemplate(
-    LocalIsolate* isolate, Handle<PropertyDict> dictionary, Handle<Name> name,
+    IsolateT* isolate, Handle<PropertyDict> dictionary, Handle<Name> name,
     int key_index, ClassBoilerplate::ValueKind value_kind, Smi value) {
   AddToDictionaryTemplate(isolate, dictionary, name, key_index, value_kind,
                           value);
@@ -572,9 +571,9 @@ template void ClassBoilerplate::AddToPropertiesTemplate(
     Isolate* isolate, Handle<SwissNameDictionary> dictionary, Handle<Name> name,
     int key_index, ClassBoilerplate::ValueKind value_kind, Smi value);
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 void ClassBoilerplate::AddToElementsTemplate(
-    LocalIsolate* isolate, Handle<NumberDictionary> dictionary, uint32_t key,
+    IsolateT* isolate, Handle<NumberDictionary> dictionary, uint32_t key,
     int key_index, ClassBoilerplate::ValueKind value_kind, Smi value) {
   AddToDictionaryTemplate(isolate, dictionary, key, key_index, value_kind,
                           value);
@@ -586,21 +585,20 @@ template void ClassBoilerplate::AddToElementsTemplate(
     LocalIsolate* isolate, Handle<NumberDictionary> dictionary, uint32_t key,
     int key_index, ClassBoilerplate::ValueKind value_kind, Smi value);
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<ClassBoilerplate> ClassBoilerplate::BuildClassBoilerplate(
-    LocalIsolate* isolate, ClassLiteral* expr) {
+    IsolateT* isolate, ClassLiteral* expr) {
   // Create a non-caching handle scope to ensure that the temporary handle used
   // by ObjectDescriptor for passing Smis around does not corrupt handle cache
   // in CanonicalHandleScope.
-  typename LocalIsolate::HandleScopeType scope(isolate);
+  typename IsolateT::HandleScopeType scope(isolate);
   auto* factory = isolate->factory();
-  ObjectDescriptor<LocalIsolate> static_desc(kMinimumClassPropertiesCount);
-  ObjectDescriptor<LocalIsolate> instance_desc(
-      kMinimumPrototypePropertiesCount);
+  ObjectDescriptor<IsolateT> static_desc(kMinimumClassPropertiesCount);
+  ObjectDescriptor<IsolateT> instance_desc(kMinimumPrototypePropertiesCount);
 
   for (int i = 0; i < expr->public_members()->length(); i++) {
     ClassLiteral::Property* property = expr->public_members()->at(i);
-    ObjectDescriptor<LocalIsolate>& desc =
+    ObjectDescriptor<IsolateT>& desc =
         property->is_static() ? static_desc : instance_desc;
     if (property->is_computed_name()) {
       if (property->kind() != ClassLiteral::Property::FIELD) {
@@ -678,7 +676,7 @@ Handle<ClassBoilerplate> ClassBoilerplate::BuildClassBoilerplate(
         continue;
     }
 
-    ObjectDescriptor<LocalIsolate>& desc =
+    ObjectDescriptor<IsolateT>& desc =
         property->is_static() ? static_desc : instance_desc;
     if (property->is_computed_name()) {
       int computed_name_index = dynamic_argument_index;
diff --git a/chromium/v8/src/objects/literal-objects.h b/chromium/v8/src/objects/literal-objects.h
index 3377bcd4c2b..a20347c4a7e 100644
--- a/chromium/v8/src/objects/literal-objects.h
+++ b/chromium/v8/src/objects/literal-objects.h
@@ -122,20 +122,20 @@ class ClassBoilerplate : public FixedArray {
   DECL_ACCESSORS(instance_elements_template, Object)
   DECL_ACCESSORS(instance_computed_properties, FixedArray)
 
-  template <typename LocalIsolate, typename Dictionary>
-  static void AddToPropertiesTemplate(LocalIsolate* isolate,
+  template <typename IsolateT, typename Dictionary>
+  static void AddToPropertiesTemplate(IsolateT* isolate,
                                       Handle<Dictionary> dictionary,
                                       Handle<Name> name, int key_index,
                                       ValueKind value_kind, Smi value);
 
-  template <typename LocalIsolate>
-  static void AddToElementsTemplate(LocalIsolate* isolate,
+  template <typename IsolateT>
+  static void AddToElementsTemplate(IsolateT* isolate,
                                     Handle<NumberDictionary> dictionary,
                                     uint32_t key, int key_index,
                                     ValueKind value_kind, Smi value);
 
-  template <typename LocalIsolate>
-  static Handle<ClassBoilerplate> BuildClassBoilerplate(LocalIsolate* isolate,
+  template <typename IsolateT>
+  static Handle<ClassBoilerplate> BuildClassBoilerplate(IsolateT* isolate,
                                                         ClassLiteral* expr);
 
   enum {
diff --git a/chromium/v8/src/objects/lookup-inl.h b/chromium/v8/src/objects/lookup-inl.h
index 5f2fbd4cc20..84a16279851 100644
--- a/chromium/v8/src/objects/lookup-inl.h
+++ b/chromium/v8/src/objects/lookup-inl.h
@@ -169,7 +169,8 @@ Handle<Name> LookupIterator::GetName() {
 
 bool LookupIterator::IsElement(JSReceiver object) const {
   return index_ <= JSObject::kMaxElementIndex ||
-         (index_ != kInvalidIndex && object.map().has_typed_array_elements());
+         (index_ != kInvalidIndex &&
+          object.map().has_typed_array_or_rab_gsab_typed_array_elements());
 }
 
 bool LookupIterator::is_dictionary_holder() const {
@@ -209,7 +210,7 @@ bool LookupIterator::IsCacheableTransition() {
 // static
 void LookupIterator::UpdateProtector(Isolate* isolate, Handle<Object> receiver,
                                      Handle<Name> name) {
-  RuntimeCallTimerScope scope(isolate, RuntimeCallCounterId::kUpdateProtector);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kUpdateProtector);
 
   // This list must be kept in sync with
   // CodeStubAssembler::CheckForAssociatedProtector!
diff --git a/chromium/v8/src/objects/lookup.cc b/chromium/v8/src/objects/lookup.cc
index d81d0059336..8f8c6081dfd 100644
--- a/chromium/v8/src/objects/lookup.cc
+++ b/chromium/v8/src/objects/lookup.cc
@@ -15,6 +15,7 @@
 #include "src/objects/field-type.h"
 #include "src/objects/hash-table-inl.h"
 #include "src/objects/heap-number-inl.h"
+#include "src/objects/map-updater.h"
 #include "src/objects/ordered-hash-table.h"
 #include "src/objects/struct-inl.h"
 
@@ -471,7 +472,7 @@ void LookupIterator::ReconfigureDataProperty(Handle<Object> value,
     Handle<Map> old_map(holder_obj->map(isolate_), isolate_);
     // Force mutable to avoid changing constant value by reconfiguring
     // kData -> kAccessor -> kData.
-    Handle<Map> new_map = Map::ReconfigureExistingProperty(
+    Handle<Map> new_map = MapUpdater::ReconfigureExistingProperty(
         isolate_, old_map, descriptor_number(), i::kData, attributes,
         PropertyConstness::kMutable);
     if (!new_map->is_dictionary_map()) {
@@ -487,11 +488,15 @@ void LookupIterator::ReconfigureDataProperty(Handle<Object> value,
 
   if (!IsElement(*holder) && !holder_obj->HasFastProperties(isolate_)) {
     if (holder_obj->map(isolate_).is_prototype_map() &&
-        (property_details_.attributes() & READ_ONLY) == 0 &&
-        (attributes & READ_ONLY) != 0) {
+        (((property_details_.attributes() & READ_ONLY) == 0 &&
+          (attributes & READ_ONLY) != 0) ||
+         (property_details_.attributes() & DONT_ENUM) !=
+             (attributes & DONT_ENUM))) {
       // Invalidate prototype validity cell when a property is reconfigured
       // from writable to read-only as this may invalidate transitioning store
       // IC handlers.
+      // Invalidate prototype validity cell when a property changes
+      // enumerability to clear the prototype chain enum cache.
       JSObject::InvalidatePrototypeChains(holder->map(isolate_));
     }
     if (holder_obj->IsJSGlobalObject(isolate_)) {
@@ -688,10 +693,10 @@ void LookupIterator::Delete() {
   } else {
     DCHECK(!name()->IsPrivateName(isolate_));
     bool is_prototype_map = holder->map(isolate_).is_prototype_map();
-    RuntimeCallTimerScope stats_scope(
-        isolate_, is_prototype_map
-                      ? RuntimeCallCounterId::kPrototypeObject_DeleteProperty
-                      : RuntimeCallCounterId::kObject_DeleteProperty);
+    RCS_SCOPE(isolate_,
+              is_prototype_map
+                  ? RuntimeCallCounterId::kPrototypeObject_DeleteProperty
+                  : RuntimeCallCounterId::kObject_DeleteProperty);
 
     PropertyNormalizationMode mode =
         is_prototype_map ? KEEP_INOBJECT_PROPERTIES : CLEAR_INOBJECT_PROPERTIES;
@@ -1026,7 +1031,9 @@ void LookupIterator::WriteDataValue(Handle<Object> value,
     GlobalDictionary dictionary =
         JSGlobalObject::cast(*holder).global_dictionary(isolate_, kAcquireLoad);
     PropertyCell cell = dictionary.CellAt(isolate_, dictionary_entry());
-    DCHECK_EQ(cell.value(), *value);
+    DCHECK(cell.value() == *value ||
+           (cell.value().IsString() && value->IsString() &&
+            String::cast(cell.value()).Equals(String::cast(*value))));
 #endif  // DEBUG
   } else {
     DCHECK_IMPLIES(holder->IsJSProxy(isolate_), name()->IsPrivate(isolate_));
@@ -1247,13 +1254,13 @@ bool LookupIterator::LookupCachedProperty(Handle<AccessorPair> accessor_pair) {
   DCHECK_EQ(state(), LookupIterator::ACCESSOR);
   DCHECK(GetAccessors()->IsAccessorPair(isolate_));
 
-  Handle<Object> getter(accessor_pair->getter(isolate_), isolate());
-  MaybeHandle<Name> maybe_name =
-      FunctionTemplateInfo::TryGetCachedPropertyName(isolate(), getter);
-  if (maybe_name.is_null()) return false;
+  base::Optional<Name> maybe_name =
+      FunctionTemplateInfo::TryGetCachedPropertyName(
+          isolate(), accessor_pair->getter(isolate_));
+  if (!maybe_name.has_value()) return false;
 
   // We have found a cached property! Modify the iterator accordingly.
-  name_ = maybe_name.ToHandleChecked();
+  name_ = handle(maybe_name.value(), isolate_);
   Restart();
   CHECK_EQ(state(), LookupIterator::DATA);
   return true;
@@ -1357,7 +1364,7 @@ ConcurrentLookupIterator::TryGetOwnConstantElement(
 
     // The access guard below protects only internalized string accesses.
     // TODO(jgruber): Support other string kinds.
-    Map wrapped_string_map = wrapped_string.synchronized_map(isolate);
+    Map wrapped_string_map = wrapped_string.map(isolate, kAcquireLoad);
     if (!InstanceTypeChecker::IsInternalizedString(
             wrapped_string_map.instance_type())) {
       return kGaveUp;
diff --git a/chromium/v8/src/objects/map-inl.h b/chromium/v8/src/objects/map-inl.h
index eb28f0b111f..96626f28eb3 100644
--- a/chromium/v8/src/objects/map-inl.h
+++ b/chromium/v8/src/objects/map-inl.h
@@ -90,19 +90,21 @@ BIT_FIELD_ACCESSORS(Map, bit_field2, is_immutable_proto,
                     Map::Bits2::IsImmutablePrototypeBit)
 
 // |bit_field3| fields.
-BIT_FIELD_ACCESSORS(Map, bit_field3, owns_descriptors,
+BIT_FIELD_ACCESSORS(Map, relaxed_bit_field3, owns_descriptors,
                     Map::Bits3::OwnsDescriptorsBit)
-BIT_FIELD_ACCESSORS(Map, bit_field3, is_deprecated, Map::Bits3::IsDeprecatedBit)
-BIT_FIELD_ACCESSORS(Map, bit_field3, is_in_retained_map_list,
+BIT_FIELD_ACCESSORS(Map, release_acquire_bit_field3, is_deprecated,
+                    Map::Bits3::IsDeprecatedBit)
+BIT_FIELD_ACCESSORS(Map, relaxed_bit_field3, is_in_retained_map_list,
                     Map::Bits3::IsInRetainedMapListBit)
-BIT_FIELD_ACCESSORS(Map, bit_field3, is_prototype_map,
+BIT_FIELD_ACCESSORS(Map, release_acquire_bit_field3, is_prototype_map,
                     Map::Bits3::IsPrototypeMapBit)
-BIT_FIELD_ACCESSORS(Map, bit_field3, is_migration_target,
+BIT_FIELD_ACCESSORS(Map, relaxed_bit_field3, is_migration_target,
                     Map::Bits3::IsMigrationTargetBit)
-BIT_FIELD_ACCESSORS(Map, bit_field3, is_extensible, Map::Bits3::IsExtensibleBit)
+BIT_FIELD_ACCESSORS2(Map, relaxed_bit_field3, bit_field3, is_extensible,
+                     Map::Bits3::IsExtensibleBit)
 BIT_FIELD_ACCESSORS(Map, bit_field3, may_have_interesting_symbols,
                     Map::Bits3::MayHaveInterestingSymbolsBit)
-BIT_FIELD_ACCESSORS(Map, bit_field3, construction_counter,
+BIT_FIELD_ACCESSORS(Map, relaxed_bit_field3, construction_counter,
                     Map::Bits3::ConstructionCounterBits)
 
 DEF_GETTER(Map, GetNamedInterceptor, InterceptorInfo) {
@@ -117,11 +119,18 @@ DEF_GETTER(Map, GetIndexedInterceptor, InterceptorInfo) {
   return InterceptorInfo::cast(info.GetIndexedPropertyHandler(cage_base));
 }
 
+// static
 bool Map::IsMostGeneralFieldType(Representation representation,
                                  FieldType field_type) {
   return !representation.IsHeapObject() || field_type.IsAny();
 }
 
+// static
+bool Map::FieldTypeIsCleared(Representation rep, FieldType type) {
+  return type.IsNone() && rep.IsHeapObject();
+}
+
+// static
 bool Map::CanHaveFastTransitionableElementsKind(InstanceType instance_type) {
   return instance_type == JS_ARRAY_TYPE ||
          instance_type == JS_PRIMITIVE_WRAPPER_TYPE ||
@@ -196,14 +205,15 @@ InternalIndex Map::LastAdded() const {
 }
 
 int Map::NumberOfOwnDescriptors() const {
-  return Bits3::NumberOfOwnDescriptorsBits::decode(bit_field3());
+  return Bits3::NumberOfOwnDescriptorsBits::decode(
+      release_acquire_bit_field3());
 }
 
 void Map::SetNumberOfOwnDescriptors(int number) {
   DCHECK_LE(number, instance_descriptors().number_of_descriptors());
   CHECK_LE(static_cast<unsigned>(number),
            static_cast<unsigned>(kMaxNumberOfDescriptors));
-  set_bit_field3(
+  set_release_acquire_bit_field3(
       Bits3::NumberOfOwnDescriptorsBits::update(bit_field3(), number));
 }
 
@@ -221,7 +231,7 @@ void Map::SetEnumLength(int length) {
     CHECK_LE(static_cast<unsigned>(length),
              static_cast<unsigned>(kMaxNumberOfDescriptors));
   }
-  set_bit_field3(Bits3::EnumLengthBits::update(bit_field3(), length));
+  set_relaxed_bit_field3(Bits3::EnumLengthBits::update(bit_field3(), length));
 }
 
 FixedArrayBase Map::GetInitialElements() const {
@@ -229,7 +239,7 @@ FixedArrayBase Map::GetInitialElements() const {
   if (has_fast_elements() || has_fast_string_wrapper_elements() ||
       has_any_nonextensible_elements()) {
     result = GetReadOnlyRoots().empty_fixed_array();
-  } else if (has_typed_array_elements()) {
+  } else if (has_typed_array_or_rab_gsab_typed_array_elements()) {
     result = GetReadOnlyRoots().empty_byte_array();
   } else if (has_dictionary_elements()) {
     result = GetReadOnlyRoots().empty_slow_element_dictionary();
@@ -271,16 +281,28 @@ void Map::set_instance_size(int value) {
 }
 
 int Map::inobject_properties_start_or_constructor_function_index() const {
-  return RELAXED_READ_BYTE_FIELD(
-      *this, kInObjectPropertiesStartOrConstructorFunctionIndexOffset);
+  if (V8_CONCURRENT_MARKING_BOOL) {
+    // TODO(solanes, v8:7790, v8:11353): Make this and the setter non-atomic
+    // when TSAN sees the map's store synchronization.
+    return RELAXED_READ_BYTE_FIELD(
+        *this, kInObjectPropertiesStartOrConstructorFunctionIndexOffset);
+  } else {
+    return ReadField<byte>(
+        kInObjectPropertiesStartOrConstructorFunctionIndexOffset);
+  }
 }
 
 void Map::set_inobject_properties_start_or_constructor_function_index(
     int value) {
   CHECK_LT(static_cast<unsigned>(value), 256);
-  RELAXED_WRITE_BYTE_FIELD(
-      *this, kInObjectPropertiesStartOrConstructorFunctionIndexOffset,
-      static_cast<byte>(value));
+  if (V8_CONCURRENT_MARKING_BOOL) {
+    RELAXED_WRITE_BYTE_FIELD(
+        *this, kInObjectPropertiesStartOrConstructorFunctionIndexOffset,
+        static_cast<byte>(value));
+  } else {
+    WriteField<byte>(kInObjectPropertiesStartOrConstructorFunctionIndexOffset,
+                     static_cast<byte>(value));
+  }
 }
 
 int Map::GetInObjectPropertiesStartInWords() const {
@@ -318,15 +340,23 @@ Handle<Map> Map::AddMissingTransitionsForTesting(
   return AddMissingTransitions(isolate, split_map, descriptors);
 }
 
-// TODO(solanes, v8:7790, v8:11353): Make the instance_type accessors non-atomic
-// when TSAN sees the map's store synchronization.
 InstanceType Map::instance_type() const {
-  return static_cast<InstanceType>(
-      RELAXED_READ_UINT16_FIELD(*this, kInstanceTypeOffset));
+  if (V8_CONCURRENT_MARKING_BOOL) {
+    // TODO(solanes, v8:7790, v8:11353): Make this and the setter non-atomic
+    // when TSAN sees the map's store synchronization.
+    return static_cast<InstanceType>(
+        RELAXED_READ_UINT16_FIELD(*this, kInstanceTypeOffset));
+  } else {
+    return static_cast<InstanceType>(ReadField<uint16_t>(kInstanceTypeOffset));
+  }
 }
 
 void Map::set_instance_type(InstanceType value) {
-  RELAXED_WRITE_UINT16_FIELD(*this, kInstanceTypeOffset, value);
+  if (V8_CONCURRENT_MARKING_BOOL) {
+    RELAXED_WRITE_UINT16_FIELD(*this, kInstanceTypeOffset, value);
+  } else {
+    WriteField<uint16_t>(kInstanceTypeOffset, value);
+  }
 }
 
 int Map::UnusedPropertyFields() const {
@@ -451,7 +481,13 @@ void Map::AccountAddedOutOfObjectPropertyField(int unused_in_property_array) {
 byte Map::bit_field() const { return ReadField<byte>(kBitFieldOffset); }
 
 void Map::set_bit_field(byte value) {
-  WriteField<byte>(kBitFieldOffset, value);
+  if (V8_CONCURRENT_MARKING_BOOL) {
+    // TODO(solanes, v8:7790, v8:11353): Make this non-atomic when TSAN sees the
+    // map's store synchronization.
+    set_relaxed_bit_field(value);
+  } else {
+    WriteField<byte>(kBitFieldOffset, value);
+  }
 }
 
 byte Map::relaxed_bit_field() const {
@@ -468,6 +504,40 @@ void Map::set_bit_field2(byte value) {
   WriteField<byte>(kBitField2Offset, value);
 }
 
+uint32_t Map::bit_field3() const {
+  if (V8_CONCURRENT_MARKING_BOOL) {
+    // TODO(solanes, v8:7790, v8:11353): Make this and the setter non-atomic
+    // when TSAN sees the map's store synchronization.
+    return relaxed_bit_field3();
+  } else {
+    return ReadField<uint32_t>(kBitField3Offset);
+  }
+}
+
+void Map::set_bit_field3(uint32_t value) {
+  if (V8_CONCURRENT_MARKING_BOOL) {
+    set_relaxed_bit_field3(value);
+  } else {
+    WriteField<uint32_t>(kBitField3Offset, value);
+  }
+}
+
+uint32_t Map::relaxed_bit_field3() const {
+  return RELAXED_READ_UINT32_FIELD(*this, kBitField3Offset);
+}
+
+void Map::set_relaxed_bit_field3(uint32_t value) {
+  RELAXED_WRITE_UINT32_FIELD(*this, kBitField3Offset, value);
+}
+
+uint32_t Map::release_acquire_bit_field3() const {
+  return ACQUIRE_READ_UINT32_FIELD(*this, kBitField3Offset);
+}
+
+void Map::set_release_acquire_bit_field3(uint32_t value) {
+  RELEASE_WRITE_UINT32_FIELD(*this, kBitField3Offset, value);
+}
+
 bool Map::is_abandoned_prototype_map() const {
   return is_prototype_map() && !owns_descriptors();
 }
@@ -523,6 +593,14 @@ bool Map::has_typed_array_elements() const {
   return IsTypedArrayElementsKind(elements_kind());
 }
 
+bool Map::has_rab_gsab_typed_array_elements() const {
+  return IsRabGsabTypedArrayElementsKind(elements_kind());
+}
+
+bool Map::has_typed_array_or_rab_gsab_typed_array_elements() const {
+  return IsTypedArrayOrRabGsabTypedArrayElementsKind(elements_kind());
+}
+
 bool Map::has_dictionary_elements() const {
   return IsDictionaryElementsKind(elements_kind());
 }
@@ -551,15 +629,16 @@ void Map::set_is_dictionary_map(bool value) {
 }
 
 bool Map::is_dictionary_map() const {
-  return Bits3::IsDictionaryMapBit::decode(bit_field3());
+  return Bits3::IsDictionaryMapBit::decode(relaxed_bit_field3());
 }
 
 void Map::mark_unstable() {
-  set_bit_field3(Bits3::IsUnstableBit::update(bit_field3(), true));
+  set_release_acquire_bit_field3(
+      Bits3::IsUnstableBit::update(bit_field3(), true));
 }
 
 bool Map::is_stable() const {
-  return !Bits3::IsUnstableBit::decode(bit_field3());
+  return !Bits3::IsUnstableBit::decode(release_acquire_bit_field3());
 }
 
 bool Map::CanBeDeprecated() const {
@@ -616,14 +695,6 @@ void Map::InitializeDescriptors(Isolate* isolate, DescriptorArray descriptors) {
                          descriptors.number_of_descriptors());
 }
 
-void Map::set_bit_field3(uint32_t bits) {
-  RELEASE_WRITE_UINT32_FIELD(*this, kBitField3Offset, bits);
-}
-
-uint32_t Map::bit_field3() const {
-  return ACQUIRE_READ_UINT32_FIELD(*this, kBitField3Offset);
-}
-
 void Map::clear_padding() {
   if (FIELD_SIZE(kOptionalPaddingOffset) == 0) return;
   DCHECK_EQ(4, FIELD_SIZE(kOptionalPaddingOffset));
@@ -698,6 +769,9 @@ ACCESSORS_CHECKED2(Map, constructor_or_back_pointer, Object,
 ACCESSORS_CHECKED(Map, native_context, NativeContext,
                   kConstructorOrBackPointerOrNativeContextOffset,
                   IsContextMap())
+ACCESSORS_CHECKED(Map, native_context_or_null, Object,
+                  kConstructorOrBackPointerOrNativeContextOffset,
+                  (value.IsNull() || value.IsNativeContext()) && IsContextMap())
 #if V8_ENABLE_WEBASSEMBLY
 ACCESSORS_CHECKED(Map, wasm_type_info, WasmTypeInfo,
                   kConstructorOrBackPointerOrNativeContextOffset,
diff --git a/chromium/v8/src/objects/map-updater.cc b/chromium/v8/src/objects/map-updater.cc
index 8ab15451a77..feb060fa518 100644
--- a/chromium/v8/src/objects/map-updater.cc
+++ b/chromium/v8/src/objects/map-updater.cc
@@ -4,6 +4,10 @@
 
 #include "src/objects/map-updater.h"
 
+#include <queue>
+
+#include "src/base/platform/mutex.h"
+#include "src/execution/frames.h"
 #include "src/execution/isolate.h"
 #include "src/handles/handles.h"
 #include "src/objects/field-type.h"
@@ -23,6 +27,66 @@ inline bool EqualImmutableValues(Object obj1, Object obj2) {
   return false;
 }
 
+V8_WARN_UNUSED_RESULT Handle<FieldType> GeneralizeFieldType(
+    Representation rep1, Handle<FieldType> type1, Representation rep2,
+    Handle<FieldType> type2, Isolate* isolate) {
+  // Cleared field types need special treatment. They represent lost knowledge,
+  // so we must be conservative, so their generalization with any other type
+  // is "Any".
+  if (Map::FieldTypeIsCleared(rep1, *type1) ||
+      Map::FieldTypeIsCleared(rep2, *type2)) {
+    return FieldType::Any(isolate);
+  }
+  if (type1->NowIs(type2)) return type2;
+  if (type2->NowIs(type1)) return type1;
+  return FieldType::Any(isolate);
+}
+
+void PrintGeneralization(
+    Isolate* isolate, Handle<Map> map, FILE* file, const char* reason,
+    InternalIndex modify_index, int split, int descriptors,
+    bool descriptor_to_field, Representation old_representation,
+    Representation new_representation, PropertyConstness old_constness,
+    PropertyConstness new_constness, MaybeHandle<FieldType> old_field_type,
+    MaybeHandle<Object> old_value, MaybeHandle<FieldType> new_field_type,
+    MaybeHandle<Object> new_value) {
+  OFStream os(file);
+  os << "[generalizing]";
+  Name name = map->instance_descriptors(isolate).GetKey(modify_index);
+  if (name.IsString()) {
+    String::cast(name).PrintOn(file);
+  } else {
+    os << "{symbol " << reinterpret_cast<void*>(name.ptr()) << "}";
+  }
+  os << ":";
+  if (descriptor_to_field) {
+    os << "c";
+  } else {
+    os << old_representation.Mnemonic() << "{";
+    if (old_field_type.is_null()) {
+      os << Brief(*(old_value.ToHandleChecked()));
+    } else {
+      old_field_type.ToHandleChecked()->PrintTo(os);
+    }
+    os << ";" << old_constness << "}";
+  }
+  os << "->" << new_representation.Mnemonic() << "{";
+  if (new_field_type.is_null()) {
+    os << Brief(*(new_value.ToHandleChecked()));
+  } else {
+    new_field_type.ToHandleChecked()->PrintTo(os);
+  }
+  os << ";" << new_constness << "} (";
+  if (strlen(reason) > 0) {
+    os << reason;
+  } else {
+    os << "+" << (descriptors - split) << " maps";
+  }
+  os << ") [";
+  JavaScriptFrame::PrintTop(isolate, file, false, true);
+  os << "]\n";
+}
+
 }  // namespace
 
 MapUpdater::MapUpdater(Isolate* isolate, Handle<Map> old_map)
@@ -142,8 +206,8 @@ Handle<Map> MapUpdater::ReconfigureToDataField(InternalIndex descriptor,
                               old_details.location(), new_representation_);
 
     new_field_type_ =
-        Map::GeneralizeFieldType(old_representation, old_field_type,
-                                 new_representation_, field_type, isolate_);
+        GeneralizeFieldType(old_representation, old_field_type,
+                            new_representation_, field_type, isolate_);
   } else {
     // We don't know if this is a first property kind reconfiguration
     // and we don't know which value was in this property previously
@@ -222,8 +286,8 @@ void MapUpdater::GeneralizeField(Handle<Map> map, InternalIndex modify_index,
                                  PropertyConstness new_constness,
                                  Representation new_representation,
                                  Handle<FieldType> new_field_type) {
-  Map::GeneralizeField(isolate_, map, modify_index, new_constness,
-                       new_representation, new_field_type);
+  GeneralizeField(isolate_, map, modify_index, new_constness,
+                  new_representation, new_field_type);
 
   DCHECK(*old_descriptors_ == old_map_->instance_descriptors(isolate_) ||
          *old_descriptors_ ==
@@ -237,6 +301,23 @@ MapUpdater::State MapUpdater::Normalize(const char* reason) {
   return state_;  // Done.
 }
 
+void MapUpdater::ShrinkInstanceSize(base::SharedMutex* map_updater_access,
+                                    Map map, int slack) {
+  DCHECK_GE(slack, 0);
+#ifdef DEBUG
+  int old_visitor_id = Map::GetVisitorId(map);
+  int new_unused = map.UnusedPropertyFields() - slack;
+#endif
+
+  {
+    base::SharedMutexGuard<base::kExclusive> mutex_guard(map_updater_access);
+    map.set_instance_size(map.InstanceSizeFromSlack(slack));
+  }
+  map.set_construction_counter(Map::kNoSlackTracking);
+  DCHECK_EQ(old_visitor_id, Map::GetVisitorId(map));
+  DCHECK_EQ(new_unused, map.UnusedPropertyFields());
+}
+
 MapUpdater::State MapUpdater::TryReconfigureToDataFieldInplace() {
   // Updating deprecated maps in-place doesn't make sense.
   if (old_map_->is_deprecated()) return state_;
@@ -262,9 +343,9 @@ MapUpdater::State MapUpdater::TryReconfigureToDataFieldInplace() {
   DCHECK_EQ(new_attributes_, old_details.attributes());
   DCHECK_EQ(kField, old_details.location());
   if (FLAG_trace_generalization) {
-    old_map_->PrintGeneralization(
-        isolate_, stdout, "uninitialized field", modified_descriptor_, old_nof_,
-        old_nof_, false, old_representation, new_representation_,
+    PrintGeneralization(
+        isolate_, old_map_, stdout, "uninitialized field", modified_descriptor_,
+        old_nof_, old_nof_, false, old_representation, new_representation_,
         old_details.constness(), new_constness_,
         handle(old_descriptors_->GetFieldType(modified_descriptor_), isolate_),
         MaybeHandle<Object>(), new_field_type_, MaybeHandle<Object>());
@@ -615,9 +696,9 @@ Handle<DescriptorArray> MapUpdater::BuildDescriptorArray() {
           GetOrComputeFieldType(target_descriptors, i,
                                 target_details.location(), next_representation);
 
-      Handle<FieldType> next_field_type = Map::GeneralizeFieldType(
-          old_details.representation(), old_field_type, next_representation,
-          target_field_type, isolate_);
+      Handle<FieldType> next_field_type =
+          GeneralizeFieldType(old_details.representation(), old_field_type,
+                              next_representation, target_field_type, isolate_);
 
       Map::GeneralizeIfCanHaveTransitionableFastElementsKind(
           isolate_, instance_type, &next_representation, &next_field_type);
@@ -795,8 +876,9 @@ MapUpdater::State MapUpdater::ConstructNewMap() {
                          isolate_);
     }
 
-    old_map_->PrintGeneralization(
-        isolate_, stdout, "", modified_descriptor_, split_nof, old_nof_,
+    PrintGeneralization(
+        isolate_, old_map_, stdout, "", modified_descriptor_, split_nof,
+        old_nof_,
         old_details.location() == kDescriptor && new_location_ == kField,
         old_details.representation(), new_details.representation(),
         old_details.constness(), new_details.constness(), old_field_type,
@@ -840,5 +922,179 @@ MapUpdater::State MapUpdater::ConstructNewMapWithIntegrityLevelTransition() {
   return state_;
 }
 
+namespace {
+
+void PrintReconfiguration(Isolate* isolate, Handle<Map> map, FILE* file,
+                          InternalIndex modify_index, PropertyKind kind,
+                          PropertyAttributes attributes) {
+  OFStream os(file);
+  os << "[reconfiguring]";
+  Name name = map->instance_descriptors(isolate).GetKey(modify_index);
+  if (name.IsString()) {
+    String::cast(name).PrintOn(file);
+  } else {
+    os << "{symbol " << reinterpret_cast<void*>(name.ptr()) << "}";
+  }
+  os << ": " << (kind == kData ? "kData" : "ACCESSORS") << ", attrs: ";
+  os << attributes << " [";
+  JavaScriptFrame::PrintTop(isolate, file, false, true);
+  os << "]\n";
+}
+
+}  // namespace
+
+// static
+Handle<Map> MapUpdater::ReconfigureExistingProperty(
+    Isolate* isolate, Handle<Map> map, InternalIndex descriptor,
+    PropertyKind kind, PropertyAttributes attributes,
+    PropertyConstness constness) {
+  // Dictionaries have to be reconfigured in-place.
+  DCHECK(!map->is_dictionary_map());
+  DCHECK_EQ(kData, kind);  // Only kData case is supported so far.
+
+  if (!map->GetBackPointer().IsMap()) {
+    // There is no benefit from reconstructing transition tree for maps without
+    // back pointers, normalize and try to hit the map cache instead.
+    return Map::Normalize(isolate, map, CLEAR_INOBJECT_PROPERTIES,
+                          "Normalize_AttributesMismatchProtoMap");
+  }
+
+  if (FLAG_trace_generalization) {
+    PrintReconfiguration(isolate, map, stdout, descriptor, kind, attributes);
+  }
+
+  return MapUpdater{isolate, map}.ReconfigureToDataField(
+      descriptor, attributes, constness, Representation::None(),
+      FieldType::None(isolate));
+}
+
+// static
+void MapUpdater::UpdateFieldType(Isolate* isolate, Handle<Map> map,
+                                 InternalIndex descriptor, Handle<Name> name,
+                                 PropertyConstness new_constness,
+                                 Representation new_representation,
+                                 const MaybeObjectHandle& new_wrapped_type) {
+  DCHECK(new_wrapped_type->IsSmi() || new_wrapped_type->IsWeak());
+  // We store raw pointers in the queue, so no allocations are allowed.
+  DisallowGarbageCollection no_gc;
+  PropertyDetails details =
+      map->instance_descriptors(isolate).GetDetails(descriptor);
+  if (details.location() != kField) return;
+  DCHECK_EQ(kData, details.kind());
+
+  if (new_constness != details.constness() && map->is_prototype_map()) {
+    JSObject::InvalidatePrototypeChains(*map);
+  }
+
+  std::queue<Map> backlog;
+  backlog.push(*map);
+
+  while (!backlog.empty()) {
+    Map current = backlog.front();
+    backlog.pop();
+
+    TransitionsAccessor transitions(isolate, current, &no_gc);
+    int num_transitions = transitions.NumberOfTransitions();
+    for (int i = 0; i < num_transitions; ++i) {
+      Map target = transitions.GetTarget(i);
+      backlog.push(target);
+    }
+    DescriptorArray descriptors = current.instance_descriptors(isolate);
+    PropertyDetails details = descriptors.GetDetails(descriptor);
+
+    // It is allowed to change representation here only from None
+    // to something or from Smi or HeapObject to Tagged.
+    DCHECK(details.representation().Equals(new_representation) ||
+           details.representation().CanBeInPlaceChangedTo(new_representation));
+
+    // Skip if already updated the shared descriptor.
+    if (new_constness != details.constness() ||
+        !new_representation.Equals(details.representation()) ||
+        descriptors.GetFieldType(descriptor) != *new_wrapped_type.object()) {
+      Descriptor d = Descriptor::DataField(
+          name, descriptors.GetFieldIndex(descriptor), details.attributes(),
+          new_constness, new_representation, new_wrapped_type);
+      descriptors.Replace(descriptor, &d);
+    }
+  }
+}
+
+// TODO(jgruber): Lock the map-updater mutex.
+// static
+void MapUpdater::GeneralizeField(Isolate* isolate, Handle<Map> map,
+                                 InternalIndex modify_index,
+                                 PropertyConstness new_constness,
+                                 Representation new_representation,
+                                 Handle<FieldType> new_field_type) {
+  DCHECK(!map->is_deprecated());
+
+  // Check if we actually need to generalize the field type at all.
+  Handle<DescriptorArray> old_descriptors(map->instance_descriptors(isolate),
+                                          isolate);
+  PropertyDetails old_details = old_descriptors->GetDetails(modify_index);
+  PropertyConstness old_constness = old_details.constness();
+  Representation old_representation = old_details.representation();
+  Handle<FieldType> old_field_type(old_descriptors->GetFieldType(modify_index),
+                                   isolate);
+
+  // Return if the current map is general enough to hold requested constness and
+  // representation/field type.
+  if (IsGeneralizableTo(new_constness, old_constness) &&
+      old_representation.Equals(new_representation) &&
+      !Map::FieldTypeIsCleared(new_representation, *new_field_type) &&
+      // Checking old_field_type for being cleared is not necessary because
+      // the NowIs check below would fail anyway in that case.
+      new_field_type->NowIs(old_field_type)) {
+    DCHECK(GeneralizeFieldType(old_representation, old_field_type,
+                               new_representation, new_field_type, isolate)
+               ->NowIs(old_field_type));
+    return;
+  }
+
+  // Determine the field owner.
+  Handle<Map> field_owner(map->FindFieldOwner(isolate, modify_index), isolate);
+  Handle<DescriptorArray> descriptors(
+      field_owner->instance_descriptors(isolate), isolate);
+  DCHECK_EQ(*old_field_type, descriptors->GetFieldType(modify_index));
+
+  new_field_type =
+      GeneralizeFieldType(old_representation, old_field_type,
+                          new_representation, new_field_type, isolate);
+
+  new_constness = GeneralizeConstness(old_constness, new_constness);
+
+  PropertyDetails details = descriptors->GetDetails(modify_index);
+  Handle<Name> name(descriptors->GetKey(modify_index), isolate);
+
+  MaybeObjectHandle wrapped_type(Map::WrapFieldType(isolate, new_field_type));
+  UpdateFieldType(isolate, field_owner, modify_index, name, new_constness,
+                  new_representation, wrapped_type);
+
+  if (new_constness != old_constness) {
+    field_owner->dependent_code().DeoptimizeDependentCodeGroup(
+        DependentCode::kFieldConstGroup);
+  }
+
+  if (!new_field_type->Equals(*old_field_type)) {
+    field_owner->dependent_code().DeoptimizeDependentCodeGroup(
+        DependentCode::kFieldTypeGroup);
+  }
+
+  if (!new_representation.Equals(old_representation)) {
+    field_owner->dependent_code().DeoptimizeDependentCodeGroup(
+        DependentCode::kFieldRepresentationGroup);
+  }
+
+  if (FLAG_trace_generalization) {
+    PrintGeneralization(
+        isolate, map, stdout, "field type generalization", modify_index,
+        map->NumberOfOwnDescriptors(), map->NumberOfOwnDescriptors(), false,
+        details.representation(),
+        descriptors->GetDetails(modify_index).representation(), old_constness,
+        new_constness, old_field_type, MaybeHandle<Object>(), new_field_type,
+        MaybeHandle<Object>());
+  }
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/objects/map-updater.h b/chromium/v8/src/objects/map-updater.h
index 427ddc90e83..c901782bf17 100644
--- a/chromium/v8/src/objects/map-updater.h
+++ b/chromium/v8/src/objects/map-updater.h
@@ -67,6 +67,22 @@ class V8_EXPORT_PRIVATE MapUpdater {
   // version and performs the steps 1-6.
   Handle<Map> Update();
 
+  static Handle<Map> ReconfigureExistingProperty(Isolate* isolate,
+                                                 Handle<Map> map,
+                                                 InternalIndex descriptor,
+                                                 PropertyKind kind,
+                                                 PropertyAttributes attributes,
+                                                 PropertyConstness constness);
+
+  static void GeneralizeField(Isolate* isolate, Handle<Map> map,
+                              InternalIndex modify_index,
+                              PropertyConstness new_constness,
+                              Representation new_representation,
+                              Handle<FieldType> new_field_type);
+
+  static void ShrinkInstanceSize(base::SharedMutex* map_updater_access, Map map,
+                                 int slack);
+
  private:
   enum State {
     kInitialized,
@@ -167,6 +183,16 @@ class V8_EXPORT_PRIVATE MapUpdater {
       Handle<DescriptorArray> descriptors, InternalIndex descriptor,
       PropertyLocation location, Representation representation);
 
+  // Update field type of the given descriptor to new representation and new
+  // type. The type must be prepared for storing in descriptor array:
+  // it must be either a simple type or a map wrapped in a weak cell.
+  static void UpdateFieldType(Isolate* isolate, Handle<Map> map,
+                              InternalIndex descriptor_number,
+                              Handle<Name> name,
+                              PropertyConstness new_constness,
+                              Representation new_representation,
+                              const MaybeObjectHandle& new_wrapped_type);
+
   void GeneralizeField(Handle<Map> map, InternalIndex modify_index,
                        PropertyConstness new_constness,
                        Representation new_representation,
diff --git a/chromium/v8/src/objects/map.cc b/chromium/v8/src/objects/map.cc
index 0f281519b79..0857d7beea3 100644
--- a/chromium/v8/src/objects/map.cc
+++ b/chromium/v8/src/objects/map.cc
@@ -10,7 +10,6 @@
 #include "src/handles/maybe-handles.h"
 #include "src/heap/heap-write-barrier-inl.h"
 #include "src/init/bootstrapper.h"
-#include "src/logging/counters-inl.h"
 #include "src/logging/log.h"
 #include "src/objects/arguments-inl.h"
 #include "src/objects/descriptor-array.h"
@@ -46,34 +45,16 @@ Map Map::GetPrototypeChainRootMap(Isolate* isolate) const {
 }
 
 // static
-MaybeHandle<JSFunction> Map::GetConstructorFunction(
-    Handle<Map> map, Handle<Context> native_context) {
-  if (map->IsPrimitiveMap()) {
-    int const constructor_function_index = map->GetConstructorFunctionIndex();
+base::Optional<JSFunction> Map::GetConstructorFunction(Map map,
+                                                       Context native_context) {
+  DisallowGarbageCollection no_gc;
+  if (map.IsPrimitiveMap()) {
+    int const constructor_function_index = map.GetConstructorFunctionIndex();
     if (constructor_function_index != kNoConstructorFunctionIndex) {
-      return handle(
-          JSFunction::cast(native_context->get(constructor_function_index)),
-          native_context->GetIsolate());
+      return JSFunction::cast(native_context.get(constructor_function_index));
     }
   }
-  return MaybeHandle<JSFunction>();
-}
-
-void Map::PrintReconfiguration(Isolate* isolate, FILE* file,
-                               InternalIndex modify_index, PropertyKind kind,
-                               PropertyAttributes attributes) {
-  OFStream os(file);
-  os << "[reconfiguring]";
-  Name name = instance_descriptors(isolate).GetKey(modify_index);
-  if (name.IsString()) {
-    String::cast(name).PrintOn(file);
-  } else {
-    os << "{symbol " << reinterpret_cast<void*>(name.ptr()) << "}";
-  }
-  os << ": " << (kind == kData ? "kData" : "ACCESSORS") << ", attrs: ";
-  os << attributes << " [";
-  JavaScriptFrame::PrintTop(isolate, file, false, true);
-  os << "]\n";
+  return {};
 }
 
 Map Map::GetInstanceTypeMap(ReadOnlyRoots roots, InstanceType type) {
@@ -373,6 +354,10 @@ VisitorId Map::GetVisitorId(Map map) {
       return kVisitWasmStruct;
     case WASM_TYPE_INFO_TYPE:
       return kVisitWasmTypeInfo;
+    case WASM_JS_FUNCTION_DATA_TYPE:
+      return kVisitWasmJSFunctionData;
+    case WASM_EXPORTED_FUNCTION_DATA_TYPE:
+      return kVisitWasmExportedFunctionData;
 #endif  // V8_ENABLE_WEBASSEMBLY
 
 #define MAKE_TQ_CASE(TYPE, Name) \
@@ -386,51 +371,6 @@ VisitorId Map::GetVisitorId(Map map) {
   }
 }
 
-void Map::PrintGeneralization(
-    Isolate* isolate, FILE* file, const char* reason,
-    InternalIndex modify_index, int split, int descriptors,
-    bool descriptor_to_field, Representation old_representation,
-    Representation new_representation, PropertyConstness old_constness,
-    PropertyConstness new_constness, MaybeHandle<FieldType> old_field_type,
-    MaybeHandle<Object> old_value, MaybeHandle<FieldType> new_field_type,
-    MaybeHandle<Object> new_value) {
-  OFStream os(file);
-  os << "[generalizing]";
-  Name name = instance_descriptors(isolate).GetKey(modify_index);
-  if (name.IsString()) {
-    String::cast(name).PrintOn(file);
-  } else {
-    os << "{symbol " << reinterpret_cast<void*>(name.ptr()) << "}";
-  }
-  os << ":";
-  if (descriptor_to_field) {
-    os << "c";
-  } else {
-    os << old_representation.Mnemonic() << "{";
-    if (old_field_type.is_null()) {
-      os << Brief(*(old_value.ToHandleChecked()));
-    } else {
-      old_field_type.ToHandleChecked()->PrintTo(os);
-    }
-    os << ";" << old_constness << "}";
-  }
-  os << "->" << new_representation.Mnemonic() << "{";
-  if (new_field_type.is_null()) {
-    os << Brief(*(new_value.ToHandleChecked()));
-  } else {
-    new_field_type.ToHandleChecked()->PrintTo(os);
-  }
-  os << ";" << new_constness << "} (";
-  if (strlen(reason) > 0) {
-    os << reason;
-  } else {
-    os << "+" << (descriptors - split) << " maps";
-  }
-  os << ") [";
-  JavaScriptFrame::PrintTop(isolate, file, false, true);
-  os << "]\n";
-}
-
 // static
 MaybeObjectHandle Map::WrapFieldType(Isolate* isolate, Handle<FieldType> type) {
   if (type->IsClass()) {
@@ -661,151 +601,6 @@ Map Map::FindFieldOwner(Isolate* isolate, InternalIndex descriptor) const {
   return result;
 }
 
-void Map::UpdateFieldType(Isolate* isolate, InternalIndex descriptor,
-                          Handle<Name> name, PropertyConstness new_constness,
-                          Representation new_representation,
-                          const MaybeObjectHandle& new_wrapped_type) {
-  DCHECK(new_wrapped_type->IsSmi() || new_wrapped_type->IsWeak());
-  // We store raw pointers in the queue, so no allocations are allowed.
-  DisallowGarbageCollection no_gc;
-  PropertyDetails details =
-      instance_descriptors(isolate).GetDetails(descriptor);
-  if (details.location() != kField) return;
-  DCHECK_EQ(kData, details.kind());
-
-  if (new_constness != details.constness() && is_prototype_map()) {
-    JSObject::InvalidatePrototypeChains(*this);
-  }
-
-  Zone zone(isolate->allocator(), ZONE_NAME);
-  ZoneQueue<Map> backlog(&zone);
-  backlog.push(*this);
-
-  while (!backlog.empty()) {
-    Map current = backlog.front();
-    backlog.pop();
-
-    TransitionsAccessor transitions(isolate, current, &no_gc);
-    int num_transitions = transitions.NumberOfTransitions();
-    for (int i = 0; i < num_transitions; ++i) {
-      Map target = transitions.GetTarget(i);
-      backlog.push(target);
-    }
-    DescriptorArray descriptors = current.instance_descriptors(isolate);
-    PropertyDetails details = descriptors.GetDetails(descriptor);
-
-    // It is allowed to change representation here only from None
-    // to something or from Smi or HeapObject to Tagged.
-    DCHECK(details.representation().Equals(new_representation) ||
-           details.representation().CanBeInPlaceChangedTo(new_representation));
-
-    // Skip if already updated the shared descriptor.
-    if (new_constness != details.constness() ||
-        !new_representation.Equals(details.representation()) ||
-        descriptors.GetFieldType(descriptor) != *new_wrapped_type.object()) {
-      Descriptor d = Descriptor::DataField(
-          name, descriptors.GetFieldIndex(descriptor), details.attributes(),
-          new_constness, new_representation, new_wrapped_type);
-      descriptors.Replace(descriptor, &d);
-    }
-  }
-}
-
-bool FieldTypeIsCleared(Representation rep, FieldType type) {
-  return type.IsNone() && rep.IsHeapObject();
-}
-
-// static
-Handle<FieldType> Map::GeneralizeFieldType(Representation rep1,
-                                           Handle<FieldType> type1,
-                                           Representation rep2,
-                                           Handle<FieldType> type2,
-                                           Isolate* isolate) {
-  // Cleared field types need special treatment. They represent lost knowledge,
-  // so we must be conservative, so their generalization with any other type
-  // is "Any".
-  if (FieldTypeIsCleared(rep1, *type1) || FieldTypeIsCleared(rep2, *type2)) {
-    return FieldType::Any(isolate);
-  }
-  if (type1->NowIs(type2)) return type2;
-  if (type2->NowIs(type1)) return type1;
-  return FieldType::Any(isolate);
-}
-
-// static
-void Map::GeneralizeField(Isolate* isolate, Handle<Map> map,
-                          InternalIndex modify_index,
-                          PropertyConstness new_constness,
-                          Representation new_representation,
-                          Handle<FieldType> new_field_type) {
-  // Check if we actually need to generalize the field type at all.
-  Handle<DescriptorArray> old_descriptors(map->instance_descriptors(isolate),
-                                          isolate);
-  PropertyDetails old_details = old_descriptors->GetDetails(modify_index);
-  PropertyConstness old_constness = old_details.constness();
-  Representation old_representation = old_details.representation();
-  Handle<FieldType> old_field_type(old_descriptors->GetFieldType(modify_index),
-                                   isolate);
-
-  // Return if the current map is general enough to hold requested constness and
-  // representation/field type.
-  if (IsGeneralizableTo(new_constness, old_constness) &&
-      old_representation.Equals(new_representation) &&
-      !FieldTypeIsCleared(new_representation, *new_field_type) &&
-      // Checking old_field_type for being cleared is not necessary because
-      // the NowIs check below would fail anyway in that case.
-      new_field_type->NowIs(old_field_type)) {
-    DCHECK(GeneralizeFieldType(old_representation, old_field_type,
-                               new_representation, new_field_type, isolate)
-               ->NowIs(old_field_type));
-    return;
-  }
-
-  // Determine the field owner.
-  Handle<Map> field_owner(map->FindFieldOwner(isolate, modify_index), isolate);
-  Handle<DescriptorArray> descriptors(
-      field_owner->instance_descriptors(isolate), isolate);
-  DCHECK_EQ(*old_field_type, descriptors->GetFieldType(modify_index));
-
-  new_field_type =
-      Map::GeneralizeFieldType(old_representation, old_field_type,
-                               new_representation, new_field_type, isolate);
-
-  new_constness = GeneralizeConstness(old_constness, new_constness);
-
-  PropertyDetails details = descriptors->GetDetails(modify_index);
-  Handle<Name> name(descriptors->GetKey(modify_index), isolate);
-
-  MaybeObjectHandle wrapped_type(WrapFieldType(isolate, new_field_type));
-  field_owner->UpdateFieldType(isolate, modify_index, name, new_constness,
-                               new_representation, wrapped_type);
-
-  if (new_constness != old_constness) {
-    field_owner->dependent_code().DeoptimizeDependentCodeGroup(
-        DependentCode::kFieldConstGroup);
-  }
-
-  if (!new_field_type->Equals(*old_field_type)) {
-    field_owner->dependent_code().DeoptimizeDependentCodeGroup(
-        DependentCode::kFieldTypeGroup);
-  }
-
-  if (!new_representation.Equals(old_representation)) {
-    field_owner->dependent_code().DeoptimizeDependentCodeGroup(
-        DependentCode::kFieldRepresentationGroup);
-  }
-
-  if (FLAG_trace_generalization) {
-    map->PrintGeneralization(
-        isolate, stdout, "field type generalization", modify_index,
-        map->NumberOfOwnDescriptors(), map->NumberOfOwnDescriptors(), false,
-        details.representation(),
-        descriptors->GetDetails(modify_index).representation(), old_constness,
-        new_constness, old_field_type, MaybeHandle<Object>(), new_field_type,
-        MaybeHandle<Object>());
-  }
-}
-
 namespace {
 
 Map SearchMigrationTarget(Isolate* isolate, Map old_map) {
@@ -831,7 +626,7 @@ Map SearchMigrationTarget(Isolate* isolate, Map old_map) {
     PropertyDetails old_details = old_descriptors.GetDetails(i);
     if (old_details.location() == kField && old_details.kind() == kData) {
       FieldType old_type = old_descriptors.GetFieldType(i);
-      if (FieldTypeIsCleared(old_details.representation(), old_type)) {
+      if (Map::FieldTypeIsCleared(old_details.representation(), old_type)) {
         return Map();
       }
     }
@@ -1362,7 +1157,7 @@ int Map::NumberOfEnumerableProperties() const {
 
 int Map::NextFreePropertyIndex() const {
   int number_of_own_descriptors = NumberOfOwnDescriptors();
-  DescriptorArray descs = instance_descriptors();
+  DescriptorArray descs = instance_descriptors(kRelaxedLoad);
   // Search properties backwards to find the last field.
   for (int i = number_of_own_descriptors - 1; i >= 0; --i) {
     PropertyDetails details = descs.GetDetails(InternalIndex(i));
@@ -1418,9 +1213,7 @@ Handle<Map> Map::RawCopy(Isolate* isolate, Handle<Map> map, int instance_size,
   Handle<HeapObject> prototype(map->prototype(), isolate);
   Map::SetPrototype(isolate, result, prototype);
   result->set_constructor_or_back_pointer(map->GetConstructor());
-  // TODO(solanes, v8:7790, v8:11353): set_relaxed_bit_field could be an atomic
-  // set if TSAN could see the transitions happening in StoreIC.
-  result->set_relaxed_bit_field(map->bit_field());
+  result->set_bit_field(map->bit_field());
   result->set_bit_field2(map->bit_field2());
   int new_bit_field3 = map->bit_field3();
   new_bit_field3 = Bits3::OwnsDescriptorsBit::update(new_bit_field3, true);
@@ -1432,6 +1225,7 @@ Handle<Map> Map::RawCopy(Isolate* isolate, Handle<Map> map, int instance_size,
   if (!map->is_dictionary_map()) {
     new_bit_field3 = Bits3::IsUnstableBit::update(new_bit_field3, false);
   }
+  // Same as bit_field comment above.
   result->set_bit_field3(new_bit_field3);
   result->clear_padding();
   return result;
@@ -2075,11 +1869,10 @@ Handle<Map> Map::TransitionToDataProperty(Isolate* isolate, Handle<Map> map,
                                           PropertyAttributes attributes,
                                           PropertyConstness constness,
                                           StoreOrigin store_origin) {
-  RuntimeCallTimerScope stats_scope(
-      isolate,
-      map->IsDetached(isolate)
-          ? RuntimeCallCounterId::kPrototypeMap_TransitionToDataProperty
-          : RuntimeCallCounterId::kMap_TransitionToDataProperty);
+  RCS_SCOPE(isolate,
+            map->IsDetached(isolate)
+                ? RuntimeCallCounterId::kPrototypeMap_TransitionToDataProperty
+                : RuntimeCallCounterId::kMap_TransitionToDataProperty);
 
   DCHECK(name->IsUniqueName());
   DCHECK(!map->is_dictionary_map());
@@ -2156,40 +1949,13 @@ Handle<Map> Map::TransitionToDataProperty(Isolate* isolate, Handle<Map> map,
   return result;
 }
 
-Handle<Map> Map::ReconfigureExistingProperty(Isolate* isolate, Handle<Map> map,
-                                             InternalIndex descriptor,
-                                             PropertyKind kind,
-                                             PropertyAttributes attributes,
-                                             PropertyConstness constness) {
-  // Dictionaries have to be reconfigured in-place.
-  DCHECK(!map->is_dictionary_map());
-
-  if (!map->GetBackPointer().IsMap()) {
-    // There is no benefit from reconstructing transition tree for maps without
-    // back pointers, normalize and try to hit the map cache instead.
-    return Map::Normalize(isolate, map, CLEAR_INOBJECT_PROPERTIES,
-                          "Normalize_AttributesMismatchProtoMap");
-  }
-
-  if (FLAG_trace_generalization) {
-    map->PrintReconfiguration(isolate, stdout, descriptor, kind, attributes);
-  }
-
-  MapUpdater mu(isolate, map);
-  DCHECK_EQ(kData, kind);  // Only kData case is supported so far.
-  Handle<Map> new_map = mu.ReconfigureToDataField(
-      descriptor, attributes, constness, Representation::None(),
-      FieldType::None(isolate));
-  return new_map;
-}
-
 Handle<Map> Map::TransitionToAccessorProperty(Isolate* isolate, Handle<Map> map,
                                               Handle<Name> name,
                                               InternalIndex descriptor,
                                               Handle<Object> getter,
                                               Handle<Object> setter,
                                               PropertyAttributes attributes) {
-  RuntimeCallTimerScope stats_scope(
+  RCS_SCOPE(
       isolate,
       map->IsDetached(isolate)
           ? RuntimeCallCounterId::kPrototypeMap_TransitionToAccessorProperty
@@ -2438,13 +2204,6 @@ bool Map::EquivalentToForNormalization(const Map other,
              JSObject::GetEmbedderFieldCount(other);
 }
 
-static void GetMinInobjectSlack(Map map, void* data) {
-  int slack = map.UnusedPropertyFields();
-  if (*reinterpret_cast<int*>(data) > slack) {
-    *reinterpret_cast<int*>(data) = slack;
-  }
-}
-
 int Map::ComputeMinObjectSlack(Isolate* isolate) {
   DisallowGarbageCollection no_gc;
   // Has to be an initial map.
@@ -2452,27 +2211,13 @@ int Map::ComputeMinObjectSlack(Isolate* isolate) {
 
   int slack = UnusedPropertyFields();
   TransitionsAccessor transitions(isolate, *this, &no_gc);
-  transitions.TraverseTransitionTree(&GetMinInobjectSlack, &slack);
+  TransitionsAccessor::TraverseCallback callback = [&](Map map) {
+    slack = std::min(slack, map.UnusedPropertyFields());
+  };
+  transitions.TraverseTransitionTree(callback);
   return slack;
 }
 
-static void ShrinkInstanceSize(Map map, void* data) {
-  int slack = *reinterpret_cast<int*>(data);
-  DCHECK_GE(slack, 0);
-#ifdef DEBUG
-  int old_visitor_id = Map::GetVisitorId(map);
-  int new_unused = map.UnusedPropertyFields() - slack;
-#endif
-  map.set_instance_size(map.InstanceSizeFromSlack(slack));
-  map.set_construction_counter(Map::kNoSlackTracking);
-  DCHECK_EQ(old_visitor_id, Map::GetVisitorId(map));
-  DCHECK_EQ(new_unused, map.UnusedPropertyFields());
-}
-
-static void StopSlackTracking(Map map, void* data) {
-  map.set_construction_counter(Map::kNoSlackTracking);
-}
-
 void Map::CompleteInobjectSlackTracking(Isolate* isolate) {
   DisallowGarbageCollection no_gc;
   // Has to be an initial map.
@@ -2480,12 +2225,19 @@ void Map::CompleteInobjectSlackTracking(Isolate* isolate) {
 
   int slack = ComputeMinObjectSlack(isolate);
   TransitionsAccessor transitions(isolate, *this, &no_gc);
+  TransitionsAccessor::TraverseCallback callback;
   if (slack != 0) {
     // Resize the initial map and all maps in its transition tree.
-    transitions.TraverseTransitionTree(&ShrinkInstanceSize, &slack);
+    callback = [&](Map map) {
+      MapUpdater::ShrinkInstanceSize(isolate->map_updater_access(), map, slack);
+    };
   } else {
-    transitions.TraverseTransitionTree(&StopSlackTracking, nullptr);
+    callback = [](Map map) {
+      // Stop slack tracking for this map.
+      map.set_construction_counter(Map::kNoSlackTracking);
+    };
   }
+  transitions.TraverseTransitionTree(callback);
 }
 
 void Map::SetInstanceDescriptors(Isolate* isolate, DescriptorArray descriptors,
@@ -2583,8 +2335,7 @@ bool Map::IsPrototypeChainInvalidated(Map map) {
 void Map::SetPrototype(Isolate* isolate, Handle<Map> map,
                        Handle<HeapObject> prototype,
                        bool enable_prototype_setup_mode) {
-  RuntimeCallTimerScope stats_scope(isolate,
-                                    RuntimeCallCounterId::kMap_SetPrototype);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kMap_SetPrototype);
 
   if (prototype->IsJSObject()) {
     Handle<JSObject> prototype_jsobj = Handle<JSObject>::cast(prototype);
diff --git a/chromium/v8/src/objects/map.h b/chromium/v8/src/objects/map.h
index e31bb9a51f4..83e5dfa365b 100644
--- a/chromium/v8/src/objects/map.h
+++ b/chromium/v8/src/objects/map.h
@@ -68,9 +68,12 @@ enum InstanceType : uint16_t;
   V(Symbol)                             \
   V(SyntheticModule)                    \
   V(TransitionArray)                    \
+  IF_WASM(V, WasmArray)                 \
+  IF_WASM(V, WasmExportedFunctionData)  \
+  IF_WASM(V, WasmFunctionData)          \
   IF_WASM(V, WasmIndirectFunctionTable) \
   IF_WASM(V, WasmInstanceObject)        \
-  IF_WASM(V, WasmArray)                 \
+  IF_WASM(V, WasmJSFunctionData)        \
   IF_WASM(V, WasmStruct)                \
   IF_WASM(V, WasmTypeInfo)              \
   V(WeakCell)
@@ -148,8 +151,7 @@ using MapHandles = std::vector<Handle<Map>>;
 //      | Byte     | [bit_field2]                                    |
 //      |          |   - new_target_is_base (bit 0)                  |
 //      |          |   - is_immutable_proto (bit 1)                  |
-//      |          |   - unused bit (bit 2)                          |
-//      |          |   - elements_kind (bits 3..7)                   |
+//      |          |   - elements_kind (bits 2..7)                   |
 // +----+----------+-------------------------------------------------+
 // | Int           | [bit_field3]                                    |
 // |               |   - enum_length (bit 0..9)                      |
@@ -211,8 +213,8 @@ class Map : public HeapObject {
   static const int kNoConstructorFunctionIndex = 0;
   inline int GetConstructorFunctionIndex() const;
   inline void SetConstructorFunctionIndex(int value);
-  static MaybeHandle<JSFunction> GetConstructorFunction(
-      Handle<Map> map, Handle<Context> native_context);
+  static base::Optional<JSFunction> GetConstructorFunction(
+      Map map, Context native_context);
 
   // Retrieve interceptors.
   DECL_GETTER(GetNamedInterceptor, InterceptorInfo)
@@ -244,7 +246,12 @@ class Map : public HeapObject {
   //
   // Bit field.
   //
+  // The setter in this pair calls the relaxed setter if concurrent marking is
+  // on, or performs the write non-atomically if it's off. The read is always
+  // non-atomically. This is done to have wider TSAN coverage on the cases where
+  // it's possible.
   DECL_PRIMITIVE_ACCESSORS(bit_field, byte)
+
   // Atomic accessors, used for allowlisting legitimate concurrent accesses.
   DECL_PRIMITIVE_ACCESSORS(relaxed_bit_field, byte)
 
@@ -266,8 +273,14 @@ class Map : public HeapObject {
   //
   // Bit field 3.
   //
+  // {bit_field3} calls the relaxed accessors if concurrent marking is on, or
+  // performs the read/write non-atomically if it's off. This is done to have
+  // wider TSAN coverage on the cases where it's possible.
   DECL_PRIMITIVE_ACCESSORS(bit_field3, uint32_t)
 
+  DECL_PRIMITIVE_ACCESSORS(relaxed_bit_field3, uint32_t)
+  DECL_PRIMITIVE_ACCESSORS(release_acquire_bit_field3, uint32_t)
+
   // Clear uninitialized padding space. This ensures that the snapshot content
   // is deterministic. Depending on the V8 build mode there could be no padding.
   V8_INLINE void clear_padding();
@@ -402,6 +415,8 @@ class Map : public HeapObject {
   inline bool has_fast_sloppy_arguments_elements() const;
   inline bool has_fast_string_wrapper_elements() const;
   inline bool has_typed_array_elements() const;
+  inline bool has_rab_gsab_typed_array_elements() const;
+  inline bool has_typed_array_or_rab_gsab_typed_array_elements() const;
   inline bool has_dictionary_elements() const;
   inline bool has_any_nonextensible_elements() const;
   inline bool has_nonextensible_elements() const;
@@ -488,18 +503,11 @@ class Map : public HeapObject {
   bool InstancesNeedRewriting(Map target, int target_number_of_fields,
                               int target_inobject, int target_unused,
                               int* old_number_of_fields) const;
-  V8_WARN_UNUSED_RESULT static Handle<FieldType> GeneralizeFieldType(
-      Representation rep1, Handle<FieldType> type1, Representation rep2,
-      Handle<FieldType> type2, Isolate* isolate);
-  static void GeneralizeField(Isolate* isolate, Handle<Map> map,
-                              InternalIndex modify_index,
-                              PropertyConstness new_constness,
-                              Representation new_representation,
-                              Handle<FieldType> new_field_type);
   // Returns true if the |field_type| is the most general one for
   // given |representation|.
   static inline bool IsMostGeneralFieldType(Representation representation,
                                             FieldType field_type);
+  static inline bool FieldTypeIsCleared(Representation rep, FieldType type);
 
   // Generalizes representation and field_type if objects with given
   // instance type can have fast elements that can be transitioned by
@@ -554,6 +562,7 @@ class Map : public HeapObject {
   // and with the Wasm type info for WebAssembly object maps.
   DECL_ACCESSORS(constructor_or_back_pointer, Object)
   DECL_ACCESSORS(native_context, NativeContext)
+  DECL_ACCESSORS(native_context_or_null, Object)
   DECL_ACCESSORS(wasm_type_info, WasmTypeInfo)
   DECL_GETTER(GetConstructor, Object)
   DECL_GETTER(GetFunctionTemplateInfo, FunctionTemplateInfo)
@@ -716,10 +725,6 @@ class Map : public HeapObject {
       Isolate* isolate, Handle<Map> map, Handle<Name> name,
       InternalIndex descriptor, Handle<Object> getter, Handle<Object> setter,
       PropertyAttributes attributes);
-  V8_EXPORT_PRIVATE static Handle<Map> ReconfigureExistingProperty(
-      Isolate* isolate, Handle<Map> map, InternalIndex descriptor,
-      PropertyKind kind, PropertyAttributes attributes,
-      PropertyConstness constness);
 
   inline void AppendDescriptor(Isolate* isolate, Descriptor* desc);
 
@@ -912,28 +917,6 @@ class Map : public HeapObject {
 
   void ReplaceDescriptors(Isolate* isolate, DescriptorArray new_descriptors);
 
-  // Update field type of the given descriptor to new representation and new
-  // type. The type must be prepared for storing in descriptor array:
-  // it must be either a simple type or a map wrapped in a weak cell.
-  void UpdateFieldType(Isolate* isolate, InternalIndex descriptor_number,
-                       Handle<Name> name, PropertyConstness new_constness,
-                       Representation new_representation,
-                       const MaybeObjectHandle& new_wrapped_type);
-
-  // TODO(ishell): Move to MapUpdater.
-  void PrintReconfiguration(Isolate* isolate, FILE* file,
-                            InternalIndex modify_index, PropertyKind kind,
-                            PropertyAttributes attributes);
-  // TODO(ishell): Move to MapUpdater.
-  void PrintGeneralization(
-      Isolate* isolate, FILE* file, const char* reason,
-      InternalIndex modify_index, int split, int descriptors,
-      bool constant_to_field, Representation old_representation,
-      Representation new_representation, PropertyConstness old_constness,
-      PropertyConstness new_constness, MaybeHandle<FieldType> old_field_type,
-      MaybeHandle<Object> old_value, MaybeHandle<FieldType> new_field_type,
-      MaybeHandle<Object> new_value);
-
   // This is the equivalent of IsMap() but avoids reading the instance type so
   // it can be used concurrently without acquire load.
   V8_INLINE bool ConcurrentIsMap(PtrComprCageBase cage_base,
diff --git a/chromium/v8/src/objects/map.tq b/chromium/v8/src/objects/map.tq
index 4cd3f2d67fa..49b2e5be36d 100644
--- a/chromium/v8/src/objects/map.tq
+++ b/chromium/v8/src/objects/map.tq
@@ -16,8 +16,7 @@ bitfield struct MapBitFields1 extends uint8 {
 bitfield struct MapBitFields2 extends uint8 {
   new_target_is_base: bool: 1 bit;
   is_immutable_prototype: bool: 1 bit;
-  unused: bool: 1 bit;
-  elements_kind: ElementsKind: 5 bit;
+  elements_kind: ElementsKind: 6 bit;
 }
 
 bitfield struct MapBitFields3 extends uint32 {
diff --git a/chromium/v8/src/objects/megadom-handler-inl.h b/chromium/v8/src/objects/megadom-handler-inl.h
new file mode 100644
index 00000000000..87efc66f0e5
--- /dev/null
+++ b/chromium/v8/src/objects/megadom-handler-inl.h
@@ -0,0 +1,26 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_OBJECTS_MEGADOM_HANDLER_INL_H_
+#define V8_OBJECTS_MEGADOM_HANDLER_INL_H_
+
+#include "src/objects/megadom-handler.h"
+#include "src/objects/objects-inl.h"  // Needed for write barriers
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+#include "torque-generated/src/objects/megadom-handler-tq-inl.inc"
+
+TQ_OBJECT_CONSTRUCTORS_IMPL(MegaDomHandler)
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_MEGADOM_HANDLER_INL_H_
diff --git a/chromium/v8/src/objects/megadom-handler.h b/chromium/v8/src/objects/megadom-handler.h
new file mode 100644
index 00000000000..00de29d0d5f
--- /dev/null
+++ b/chromium/v8/src/objects/megadom-handler.h
@@ -0,0 +1,32 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_OBJECTS_MEGADOM_HANDLER_H_
+#define V8_OBJECTS_MEGADOM_HANDLER_H_
+
+#include "src/objects/heap-object.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+#include "torque-generated/src/objects/megadom-handler-tq.inc"
+
+class MegaDomHandler
+    : public TorqueGeneratedMegaDomHandler<MegaDomHandler, HeapObject> {
+ public:
+  void BriefPrintDetails(std::ostream& os);
+  class BodyDescriptor;
+
+  TQ_OBJECT_CONSTRUCTORS(MegaDomHandler)
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_MEGADOM_HANDLER_H_
diff --git a/chromium/v8/src/objects/megadom-handler.tq b/chromium/v8/src/objects/megadom-handler.tq
new file mode 100644
index 00000000000..7daaa5a8d80
--- /dev/null
+++ b/chromium/v8/src/objects/megadom-handler.tq
@@ -0,0 +1,11 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+@generateCppClass
+@generatePrint
+@generateBodyDescriptor
+extern class MegaDomHandler extends HeapObject {
+  accessor: MaybeObject;
+  context: MaybeObject;
+}
diff --git a/chromium/v8/src/objects/object-list-macros.h b/chromium/v8/src/objects/object-list-macros.h
index fc3f956d2db..837f895f5fc 100644
--- a/chromium/v8/src/objects/object-list-macros.h
+++ b/chromium/v8/src/objects/object-list-macros.h
@@ -166,6 +166,7 @@ class ZoneForwardList;
   V(LoadHandler)                               \
   V(Map)                                       \
   V(MapCache)                                  \
+  V(MegaDomHandler)                            \
   V(Module)                                    \
   V(Microtask)                                 \
   V(Name)                                      \
@@ -217,8 +218,11 @@ class ZoneForwardList;
   IF_WASM(V, WasmArray)                        \
   IF_WASM(V, WasmExceptionObject)              \
   IF_WASM(V, WasmExceptionPackage)             \
+  IF_WASM(V, WasmExportedFunctionData)         \
+  IF_WASM(V, WasmFunctionData)                 \
   IF_WASM(V, WasmGlobalObject)                 \
   IF_WASM(V, WasmInstanceObject)               \
+  IF_WASM(V, WasmJSFunctionData)               \
   IF_WASM(V, WasmMemoryObject)                 \
   IF_WASM(V, WasmModuleObject)                 \
   IF_WASM(V, WasmStruct)                       \
diff --git a/chromium/v8/src/objects/object-macros-undef.h b/chromium/v8/src/objects/object-macros-undef.h
index e2c5961ab2a..1d240729ff6 100644
--- a/chromium/v8/src/objects/object-macros-undef.h
+++ b/chromium/v8/src/objects/object-macros-undef.h
@@ -14,10 +14,8 @@
 #undef DECL_PRIMITIVE_GETTER
 #undef DECL_PRIMITIVE_SETTER
 #undef DECL_PRIMITIVE_ACCESSORS
-#undef DECL_SYNCHRONIZED_PRIMITIVE_ACCESSORS
 #undef DECL_BOOLEAN_ACCESSORS
 #undef DECL_INT_ACCESSORS
-#undef DECL_SYNCHRONIZED_INT_ACCESSORS
 #undef DECL_INT32_ACCESSORS
 #undef DECL_UINT16_ACCESSORS
 #undef DECL_INT16_ACCESSORS
@@ -61,7 +59,9 @@
 #undef RELEASE_ACQUIRE_WEAK_ACCESSORS
 #undef SMI_ACCESSORS_CHECKED
 #undef SMI_ACCESSORS
-#undef SYNCHRONIZED_SMI_ACCESSORS
+#undef DECL_RELEASE_ACQUIRE_INT_ACCESSORS
+#undef RELEASE_ACQUIRE_SMI_ACCESSORS
+#undef DECL_RELAXED_SMI_ACCESSORS
 #undef RELAXED_SMI_ACCESSORS
 #undef BOOL_GETTER
 #undef BOOL_ACCESSORS
diff --git a/chromium/v8/src/objects/object-macros.h b/chromium/v8/src/objects/object-macros.h
index 2a742d5d77d..ed4637a406a 100644
--- a/chromium/v8/src/objects/object-macros.h
+++ b/chromium/v8/src/objects/object-macros.h
@@ -56,17 +56,10 @@
   DECL_PRIMITIVE_GETTER(name, type)          \
   DECL_PRIMITIVE_SETTER(name, type)
 
-#define DECL_SYNCHRONIZED_PRIMITIVE_ACCESSORS(name, type) \
-  inline type synchronized_##name() const;                \
-  inline void synchronized_set_##name(type value);
-
 #define DECL_BOOLEAN_ACCESSORS(name) DECL_PRIMITIVE_ACCESSORS(name, bool)
 
 #define DECL_INT_ACCESSORS(name) DECL_PRIMITIVE_ACCESSORS(name, int)
 
-#define DECL_SYNCHRONIZED_INT_ACCESSORS(name) \
-  DECL_SYNCHRONIZED_PRIMITIVE_ACCESSORS(name, int)
-
 #define DECL_INT32_ACCESSORS(name) DECL_PRIMITIVE_ACCESSORS(name, int32_t)
 
 #define DECL_UINT16_ACCESSORS(name) \
@@ -324,21 +317,29 @@
 #define SMI_ACCESSORS(holder, name, offset) \
   SMI_ACCESSORS_CHECKED(holder, name, offset, true)
 
-#define SYNCHRONIZED_SMI_ACCESSORS(holder, name, offset)                 \
-  int holder::synchronized_##name() const {                              \
+#define DECL_RELEASE_ACQUIRE_INT_ACCESSORS(name) \
+  inline int name(AcquireLoadTag) const;         \
+  inline void set_##name(int value, ReleaseStoreTag);
+
+#define RELEASE_ACQUIRE_SMI_ACCESSORS(holder, name, offset)              \
+  int holder::name(AcquireLoadTag) const {                               \
     Smi value = TaggedField<Smi, offset>::Acquire_Load(*this);           \
     return value.value();                                                \
   }                                                                      \
-  void holder::synchronized_set_##name(int value) {                      \
+  void holder::set_##name(int value, ReleaseStoreTag) {                  \
     TaggedField<Smi, offset>::Release_Store(*this, Smi::FromInt(value)); \
   }
 
+#define DECL_RELAXED_SMI_ACCESSORS(name) \
+  inline int name(RelaxedLoadTag) const; \
+  inline void set_##name(int value, RelaxedStoreTag);
+
 #define RELAXED_SMI_ACCESSORS(holder, name, offset)                      \
-  int holder::relaxed_read_##name() const {                              \
+  int holder::name(RelaxedLoadTag) const {                               \
     Smi value = TaggedField<Smi, offset>::Relaxed_Load(*this);           \
     return value.value();                                                \
   }                                                                      \
-  void holder::relaxed_write_##name(int value) {                         \
+  void holder::set_##name(int value, RelaxedStoreTag) {                  \
     TaggedField<Smi, offset>::Relaxed_Store(*this, Smi::FromInt(value)); \
   }
 
@@ -604,7 +605,7 @@ static_assert(sizeof(unsigned) == sizeof(uint32_t),
                       static_cast<base::Atomic8>(value));
 
 #ifdef OBJECT_PRINT
-#define DECL_PRINTER(Name) void Name##Print(std::ostream& os);  // NOLINT
+#define DECL_PRINTER(Name) void Name##Print(std::ostream& os);
 #else
 #define DECL_PRINTER(Name)
 #endif
diff --git a/chromium/v8/src/objects/objects-body-descriptors-inl.h b/chromium/v8/src/objects/objects-body-descriptors-inl.h
index 2ffe2a44144..18dceb527d4 100644
--- a/chromium/v8/src/objects/objects-body-descriptors-inl.h
+++ b/chromium/v8/src/objects/objects-body-descriptors-inl.h
@@ -15,6 +15,7 @@
 #include "src/objects/hash-table.h"
 #include "src/objects/js-collection.h"
 #include "src/objects/js-weak-refs.h"
+#include "src/objects/megadom-handler-inl.h"
 #include "src/objects/objects-body-descriptors.h"
 #include "src/objects/oddball.h"
 #include "src/objects/ordered-hash-table-inl.h"
@@ -103,12 +104,17 @@ DISABLE_CFI_PERF void BodyDescriptorBase::IteratePointers(HeapObject obj,
                                                           int start_offset,
                                                           int end_offset,
                                                           ObjectVisitor* v) {
+  if (start_offset == HeapObject::kMapOffset) {
+    v->VisitMapPointer(obj);
+    start_offset += kTaggedSize;
+  }
   v->VisitPointers(obj, obj.RawField(start_offset), obj.RawField(end_offset));
 }
 
 template <typename ObjectVisitor>
 void BodyDescriptorBase::IteratePointer(HeapObject obj, int offset,
                                         ObjectVisitor* v) {
+  DCHECK_NE(offset, HeapObject::kMapOffset);
   v->VisitPointer(obj, obj.RawField(offset));
 }
 
@@ -122,6 +128,7 @@ DISABLE_CFI_PERF void BodyDescriptorBase::IterateMaybeWeakPointers(
 template <typename ObjectVisitor>
 void BodyDescriptorBase::IterateMaybeWeakPointer(HeapObject obj, int offset,
                                                  ObjectVisitor* v) {
+  DCHECK_NE(offset, HeapObject::kMapOffset);
   v->VisitPointer(obj, obj.RawMaybeWeakField(offset));
 }
 
@@ -423,7 +430,7 @@ class ByteArray::BodyDescriptor final : public BodyDescriptorBase {
                                  ObjectVisitor* v) {}
 
   static inline int SizeOf(Map map, HeapObject obj) {
-    return ByteArray::SizeFor(ByteArray::cast(obj).synchronized_length());
+    return ByteArray::SizeFor(ByteArray::cast(obj).length(kAcquireLoad));
   }
 };
 
@@ -444,7 +451,7 @@ class BytecodeArray::BodyDescriptor final : public BodyDescriptorBase {
 
   static inline int SizeOf(Map map, HeapObject obj) {
     return BytecodeArray::SizeFor(
-        BytecodeArray::cast(obj).synchronized_length());
+        BytecodeArray::cast(obj).length(kAcquireLoad));
   }
 };
 
@@ -457,7 +464,7 @@ class BigInt::BodyDescriptor final : public BodyDescriptorBase {
                                  ObjectVisitor* v) {}
 
   static inline int SizeOf(Map map, HeapObject obj) {
-    return BigInt::SizeFor(BigInt::cast(obj).synchronized_length());
+    return BigInt::SizeFor(BigInt::cast(obj).length(kAcquireLoad));
   }
 };
 
@@ -471,7 +478,7 @@ class FixedDoubleArray::BodyDescriptor final : public BodyDescriptorBase {
 
   static inline int SizeOf(Map map, HeapObject obj) {
     return FixedDoubleArray::SizeFor(
-        FixedDoubleArray::cast(obj).synchronized_length());
+        FixedDoubleArray::cast(obj).length(kAcquireLoad));
   }
 };
 
@@ -582,6 +589,43 @@ class WasmTypeInfo::BodyDescriptor final : public BodyDescriptorBase {
   static inline int SizeOf(Map map, HeapObject object) { return kSize; }
 };
 
+class WasmJSFunctionData::BodyDescriptor final : public BodyDescriptorBase {
+ public:
+  static bool IsValidSlot(Map map, HeapObject obj, int offset) {
+    UNREACHABLE();
+  }
+
+  template <typename ObjectVisitor>
+  static inline void IterateBody(Map map, HeapObject obj, int object_size,
+                                 ObjectVisitor* v) {
+    Foreign::BodyDescriptor::IterateBody<ObjectVisitor>(map, obj, object_size,
+                                                        v);
+    IteratePointers(obj, WasmFunctionData::kStartOfStrongFieldsOffset,
+                    kEndOfStrongFieldsOffset, v);
+  }
+
+  static inline int SizeOf(Map map, HeapObject object) { return kSize; }
+};
+
+class WasmExportedFunctionData::BodyDescriptor final
+    : public BodyDescriptorBase {
+ public:
+  static bool IsValidSlot(Map map, HeapObject obj, int offset) {
+    UNREACHABLE();
+  }
+
+  template <typename ObjectVisitor>
+  static inline void IterateBody(Map map, HeapObject obj, int object_size,
+                                 ObjectVisitor* v) {
+    Foreign::BodyDescriptor::IterateBody<ObjectVisitor>(map, obj, object_size,
+                                                        v);
+    IteratePointers(obj, WasmFunctionData::kStartOfStrongFieldsOffset,
+                    kEndOfStrongFieldsOffset, v);
+  }
+
+  static inline int SizeOf(Map map, HeapObject object) { return kSize; }
+};
+
 class WasmInstanceObject::BodyDescriptor final : public BodyDescriptorBase {
  public:
   static bool IsValidSlot(Map map, HeapObject obj, int offset) {
@@ -655,7 +699,7 @@ class WasmStruct::BodyDescriptor final : public BodyDescriptorBase {
   }
 
   static inline int SizeOf(Map map, HeapObject object) {
-    return map.instance_size();
+    return WasmStruct::GcSafeSize(map);
   }
 };
 
@@ -944,6 +988,12 @@ ReturnType BodyDescriptorApply(InstanceType type, T1 p1, T2 p2, T3 p3, T4 p4) {
 #if V8_ENABLE_WEBASSEMBLY
     case WASM_ARRAY_TYPE:
       return Op::template apply<WasmArray::BodyDescriptor>(p1, p2, p3, p4);
+    case WASM_EXPORTED_FUNCTION_DATA_TYPE:
+      return Op::template apply<WasmExportedFunctionData::BodyDescriptor>(
+          p1, p2, p3, p4);
+    case WASM_JS_FUNCTION_DATA_TYPE:
+      return Op::template apply<WasmJSFunctionData::BodyDescriptor>(p1, p2, p3,
+                                                                    p4);
     case WASM_STRUCT_TYPE:
       return Op::template apply<WasmStruct::BodyDescriptor>(p1, p2, p3, p4);
     case WASM_TYPE_INFO_TYPE:
@@ -1134,7 +1184,7 @@ ReturnType BodyDescriptorApply(InstanceType type, T1 p1, T2 p2, T3 p3, T4 p4) {
 
 template <typename ObjectVisitor>
 void HeapObject::IterateFast(ObjectVisitor* v) {
-  BodyDescriptorBase::IteratePointer(*this, kMapOffset, v);
+  v->VisitMapPointer(*this);
   IterateBodyFast(v);
 }
 
diff --git a/chromium/v8/src/objects/objects-definitions.h b/chromium/v8/src/objects/objects-definitions.h
index 43560caab81..20ce96aae5d 100644
--- a/chromium/v8/src/objects/objects-definitions.h
+++ b/chromium/v8/src/objects/objects-definitions.h
@@ -152,12 +152,8 @@ namespace internal {
     template_object_description)                                               \
   V(_, TUPLE2_TYPE, Tuple2, tuple2)                                            \
   IF_WASM(V, _, WASM_EXCEPTION_TAG_TYPE, WasmExceptionTag, wasm_exception_tag) \
-  IF_WASM(V, _, WASM_EXPORTED_FUNCTION_DATA_TYPE, WasmExportedFunctionData,    \
-          wasm_exported_function_data)                                         \
   IF_WASM(V, _, WASM_INDIRECT_FUNCTION_TABLE_TYPE, WasmIndirectFunctionTable,  \
-          wasm_indirect_function_table)                                        \
-  IF_WASM(V, _, WASM_JS_FUNCTION_DATA_TYPE, WasmJSFunctionData,                \
-          wasm_js_function_data)
+          wasm_indirect_function_table)
 
 // Adapts one STRUCT_LIST_GENERATOR entry to the STRUCT_LIST entry
 #define STRUCT_LIST_ADAPTER(V, NAME, Name, name) V(NAME, Name, name)
diff --git a/chromium/v8/src/objects/objects-inl.h b/chromium/v8/src/objects/objects-inl.h
index c94feca2501..1a0ff834b26 100644
--- a/chromium/v8/src/objects/objects-inl.h
+++ b/chromium/v8/src/objects/objects-inl.h
@@ -16,6 +16,7 @@
 #include "src/base/memory.h"
 #include "src/builtins/builtins.h"
 #include "src/common/external-pointer-inl.h"
+#include "src/common/globals.h"
 #include "src/handles/handles-inl.h"
 #include "src/heap/factory.h"
 #include "src/heap/heap-write-barrier-inl.h"
@@ -42,7 +43,6 @@
 #include "src/objects/tagged-impl-inl.h"
 #include "src/objects/tagged-index.h"
 #include "src/objects/templates.h"
-#include "src/sanitizer/tsan.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
@@ -631,10 +631,9 @@ void Object::InitExternalPointerField(size_t offset, Isolate* isolate,
   i::InitExternalPointerField(field_address(offset), isolate, value, tag);
 }
 
-Address Object::ReadExternalPointerField(size_t offset,
-                                         PtrComprCageBase isolate_root,
+Address Object::ReadExternalPointerField(size_t offset, Isolate* isolate,
                                          ExternalPointerTag tag) const {
-  return i::ReadExternalPointerField(field_address(offset), isolate_root, tag);
+  return i::ReadExternalPointerField(field_address(offset), isolate, tag);
 }
 
 void Object::WriteExternalPointerField(size_t offset, Isolate* isolate,
@@ -650,11 +649,26 @@ MaybeObjectSlot HeapObject::RawMaybeWeakField(int byte_offset) const {
   return MaybeObjectSlot(field_address(byte_offset));
 }
 
-MapWord MapWord::FromMap(const Map map) { return MapWord(map.ptr()); }
+MapWord MapWord::FromMap(const Map map) {
+  DCHECK(map.is_null() || !MapWord::IsPacked(map.ptr()));
+#ifdef V8_MAP_PACKING
+  return MapWord(Pack(map.ptr()));
+#else
+  return MapWord(map.ptr());
+#endif
+}
 
-Map MapWord::ToMap() const { return Map::unchecked_cast(Object(value_)); }
+Map MapWord::ToMap() const {
+#ifdef V8_MAP_PACKING
+  return Map::unchecked_cast(Object(Unpack(value_)));
+#else
+  return Map::unchecked_cast(Object(value_));
+#endif
+}
 
-bool MapWord::IsForwardingAddress() const { return HAS_SMI_TAG(value_); }
+bool MapWord::IsForwardingAddress() const {
+  return (value_ & kForwardingTagMask) == kForwardingTag;
+}
 
 MapWord MapWord::FromForwardingAddress(HeapObject object) {
   return MapWord(object.ptr() - kHeapObjectTag);
@@ -697,7 +711,9 @@ ReadOnlyRoots HeapObject::GetReadOnlyRoots(PtrComprCageBase cage_base) const {
 #endif
 }
 
-DEF_GETTER(HeapObject, map, Map) { return map_word(cage_base).ToMap(); }
+DEF_GETTER(HeapObject, map, Map) {
+  return map_word(cage_base, kRelaxedLoad).ToMap();
+}
 
 void HeapObject::set_map(Map value) {
 #ifdef VERIFY_HEAP
@@ -705,7 +721,7 @@ void HeapObject::set_map(Map value) {
     GetHeapFromWritableObject(*this)->VerifyObjectLayoutChange(*this, value);
   }
 #endif
-  set_map_word(MapWord::FromMap(value));
+  set_map_word(MapWord::FromMap(value), kRelaxedStore);
 #ifndef V8_DISABLE_WRITE_BARRIERS
   if (!value.is_null()) {
     // TODO(1600) We are passing kNullAddress as a slot because maps can never
@@ -715,17 +731,21 @@ void HeapObject::set_map(Map value) {
 #endif
 }
 
-DEF_GETTER(HeapObject, synchronized_map, Map) {
-  return synchronized_map_word(cage_base).ToMap();
+Map HeapObject::map(AcquireLoadTag tag) const {
+  PtrComprCageBase cage_base = GetPtrComprCageBase(*this);
+  return HeapObject::map(cage_base, tag);
+}
+Map HeapObject::map(PtrComprCageBase cage_base, AcquireLoadTag tag) const {
+  return map_word(cage_base, tag).ToMap();
 }
 
-void HeapObject::synchronized_set_map(Map value) {
+void HeapObject::set_map(Map value, ReleaseStoreTag tag) {
 #ifdef VERIFY_HEAP
   if (FLAG_verify_heap && !value.is_null()) {
     GetHeapFromWritableObject(*this)->VerifyObjectLayoutChange(*this, value);
   }
 #endif
-  synchronized_set_map_word(MapWord::FromMap(value));
+  set_map_word(MapWord::FromMap(value), tag);
 #ifndef V8_DISABLE_WRITE_BARRIERS
   if (!value.is_null()) {
     // TODO(1600) We are passing kNullAddress as a slot because maps can never
@@ -742,11 +762,12 @@ void HeapObject::set_map_no_write_barrier(Map value) {
     GetHeapFromWritableObject(*this)->VerifyObjectLayoutChange(*this, value);
   }
 #endif
-  set_map_word(MapWord::FromMap(value));
+  set_map_word(MapWord::FromMap(value), kRelaxedStore);
 }
 
 void HeapObject::set_map_after_allocation(Map value, WriteBarrierMode mode) {
-  set_map_word(MapWord::FromMap(value));
+  MapWord mapword = MapWord::FromMap(value);
+  set_map_word(mapword, kRelaxedStore);
 #ifndef V8_DISABLE_WRITE_BARRIERS
   if (mode != SKIP_WRITE_BARRIER) {
     DCHECK(!value.is_null());
@@ -761,20 +782,28 @@ ObjectSlot HeapObject::map_slot() const {
   return ObjectSlot(MapField::address(*this));
 }
 
-DEF_GETTER(HeapObject, map_word, MapWord) {
-  return MapField::Relaxed_Load(cage_base, *this);
+MapWord HeapObject::map_word(RelaxedLoadTag tag) const {
+  PtrComprCageBase cage_base = GetPtrComprCageBase(*this);
+  return HeapObject::map_word(cage_base, tag);
+}
+MapWord HeapObject::map_word(PtrComprCageBase cage_base, RelaxedLoadTag) const {
+  return MapField::Relaxed_Load_Map_Word(cage_base, *this);
 }
 
-void HeapObject::set_map_word(MapWord map_word) {
-  MapField::Relaxed_Store(*this, map_word);
+void HeapObject::set_map_word(MapWord map_word, RelaxedStoreTag) {
+  MapField::Relaxed_Store_Map_Word(*this, map_word);
 }
 
-DEF_GETTER(HeapObject, synchronized_map_word, MapWord) {
-  return MapField::Acquire_Load(cage_base, *this);
+MapWord HeapObject::map_word(AcquireLoadTag tag) const {
+  PtrComprCageBase cage_base = GetPtrComprCageBase(*this);
+  return HeapObject::map_word(cage_base, tag);
+}
+MapWord HeapObject::map_word(PtrComprCageBase cage_base, AcquireLoadTag) const {
+  return MapField::Acquire_Load_No_Unpack(cage_base, *this);
 }
 
-void HeapObject::synchronized_set_map_word(MapWord map_word) {
-  MapField::Release_Store(*this, map_word);
+void HeapObject::set_map_word(MapWord map_word, ReleaseStoreTag) {
+  MapField::Release_Store_Map_Word(*this, map_word);
 }
 
 bool HeapObject::release_compare_and_swap_map_word(MapWord old_map_word,
@@ -1081,8 +1110,7 @@ static inline uint32_t ObjectAddressForHashing(Address object) {
 static inline Handle<Object> MakeEntryPair(Isolate* isolate, size_t index,
                                            Handle<Object> value) {
   Handle<Object> key = isolate->factory()->SizeToString(index);
-  Handle<FixedArray> entry_storage =
-      isolate->factory()->NewUninitializedFixedArray(2);
+  Handle<FixedArray> entry_storage = isolate->factory()->NewFixedArray(2);
   {
     entry_storage->set(0, *key, SKIP_WRITE_BARRIER);
     entry_storage->set(1, *value, SKIP_WRITE_BARRIER);
@@ -1093,8 +1121,7 @@ static inline Handle<Object> MakeEntryPair(Isolate* isolate, size_t index,
 
 static inline Handle<Object> MakeEntryPair(Isolate* isolate, Handle<Object> key,
                                            Handle<Object> value) {
-  Handle<FixedArray> entry_storage =
-      isolate->factory()->NewUninitializedFixedArray(2);
+  Handle<FixedArray> entry_storage = isolate->factory()->NewFixedArray(2);
   {
     entry_storage->set(0, *key, SKIP_WRITE_BARRIER);
     entry_storage->set(1, *value, SKIP_WRITE_BARRIER);
diff --git a/chromium/v8/src/objects/objects.cc b/chromium/v8/src/objects/objects.cc
index 18e659a910b..74b970b5451 100644
--- a/chromium/v8/src/objects/objects.cc
+++ b/chromium/v8/src/objects/objects.cc
@@ -41,7 +41,6 @@
 #include "src/heap/read-only-heap.h"
 #include "src/ic/ic.h"
 #include "src/init/bootstrapper.h"
-#include "src/logging/counters-inl.h"
 #include "src/logging/counters.h"
 #include "src/logging/log.h"
 #include "src/objects/allocation-site-inl.h"
@@ -102,6 +101,7 @@
 #include "src/objects/literal-objects-inl.h"
 #include "src/objects/map-inl.h"
 #include "src/objects/map.h"
+#include "src/objects/megadom-handler-inl.h"
 #include "src/objects/microtask-inl.h"
 #include "src/objects/module-inl.h"
 #include "src/objects/promise-inl.h"
@@ -1320,8 +1320,8 @@ Handle<SharedFunctionInfo> FunctionTemplateInfo::GetOrCreateSharedFunctionInfo(
   return result;
 }
 
-bool FunctionTemplateInfo::IsTemplateFor(Map map) {
-  RuntimeCallTimerScope timer(
+bool FunctionTemplateInfo::IsTemplateFor(Map map) const {
+  RCS_SCOPE(
       LocalHeap::Current() == nullptr
           ? GetIsolate()->counters()->runtime_call_stats()
           : LocalIsolate::FromHeap(LocalHeap::Current())->runtime_call_stats(),
@@ -1350,16 +1350,32 @@ bool FunctionTemplateInfo::IsTemplateFor(Map map) {
   return false;
 }
 
+bool FunctionTemplateInfo::IsLeafTemplateForApiObject(Object object) const {
+  i::DisallowGarbageCollection no_gc;
+
+  if (!object.IsJSApiObject()) {
+    return false;
+  }
+
+  bool result = false;
+  Map map = HeapObject::cast(object).map();
+  Object constructor_obj = map.GetConstructor();
+  if (constructor_obj.IsJSFunction()) {
+    JSFunction fun = JSFunction::cast(constructor_obj);
+    result = (*this == fun.shared().function_data(kAcquireLoad));
+  } else if (constructor_obj.IsFunctionTemplateInfo()) {
+    result = (*this == constructor_obj);
+  }
+  DCHECK_IMPLIES(result, IsTemplateFor(map));
+  return result;
+}
+
 // static
 FunctionTemplateRareData FunctionTemplateInfo::AllocateFunctionTemplateRareData(
     Isolate* isolate, Handle<FunctionTemplateInfo> function_template_info) {
   DCHECK(function_template_info->rare_data(kAcquireLoad).IsUndefined(isolate));
-  Handle<Struct> struct_obj = isolate->factory()->NewStruct(
-      FUNCTION_TEMPLATE_RARE_DATA_TYPE, AllocationType::kOld);
   Handle<FunctionTemplateRareData> rare_data =
-      i::Handle<FunctionTemplateRareData>::cast(struct_obj);
-  rare_data->set_c_function(Smi(0));
-  rare_data->set_c_signature(Smi(0));
+      isolate->factory()->NewFunctionTemplateRareData();
   function_template_info->set_rare_data(*rare_data, kReleaseStore);
   return *rare_data;
 }
@@ -1887,11 +1903,9 @@ std::ostream& operator<<(std::ostream& os, const Brief& v) {
   return os;
 }
 
-void Smi::SmiPrint(std::ostream& os) const {  // NOLINT
-  os << value();
-}
+void Smi::SmiPrint(std::ostream& os) const { os << value(); }
 
-void HeapObject::HeapObjectShortPrint(std::ostream& os) {  // NOLINT
+void HeapObject::HeapObjectShortPrint(std::ostream& os) {
   os << AsHex::Address(this->ptr()) << " ";
 
   if (IsString()) {
@@ -2043,7 +2057,7 @@ void HeapObject::HeapObjectShortPrint(std::ostream& os) {  // NOLINT
       os << "<FeedbackVector[" << FeedbackVector::cast(*this).length() << "]>";
       break;
     case FREE_SPACE_TYPE:
-      os << "<FreeSpace[" << FreeSpace::cast(*this).size() << "]>";
+      os << "<FreeSpace[" << FreeSpace::cast(*this).size(kRelaxedLoad) << "]>";
       break;
 
     case PREPARSE_DATA_TYPE: {
@@ -2200,6 +2214,10 @@ void Tuple2::BriefPrintDetails(std::ostream& os) {
   os << " " << Brief(value1()) << ", " << Brief(value2());
 }
 
+void MegaDomHandler::BriefPrintDetails(std::ostream& os) {
+  os << " " << Brief(accessor()) << ", " << Brief(context());
+}
+
 void ClassPositions::BriefPrintDetails(std::ostream& os) {
   os << " " << start() << ", " << end();
 }
@@ -2240,7 +2258,7 @@ int HeapObject::SizeFromMap(Map map) const {
   if (base::IsInRange(instance_type, FIRST_FIXED_ARRAY_TYPE,
                       LAST_FIXED_ARRAY_TYPE)) {
     return FixedArray::SizeFor(
-        FixedArray::unchecked_cast(*this).synchronized_length());
+        FixedArray::unchecked_cast(*this).length(kAcquireLoad));
   }
   if (base::IsInRange(instance_type, FIRST_CONTEXT_TYPE, LAST_CONTEXT_TYPE)) {
     if (instance_type == NATIVE_CONTEXT_TYPE) return NativeContext::kSize;
@@ -2251,29 +2269,29 @@ int HeapObject::SizeFromMap(Map map) const {
     // Strings may get concurrently truncated, hence we have to access its
     // length synchronized.
     return SeqOneByteString::SizeFor(
-        SeqOneByteString::unchecked_cast(*this).synchronized_length());
+        SeqOneByteString::unchecked_cast(*this).length(kAcquireLoad));
   }
   if (instance_type == BYTE_ARRAY_TYPE) {
     return ByteArray::SizeFor(
-        ByteArray::unchecked_cast(*this).synchronized_length());
+        ByteArray::unchecked_cast(*this).length(kAcquireLoad));
   }
   if (instance_type == BYTECODE_ARRAY_TYPE) {
     return BytecodeArray::SizeFor(
-        BytecodeArray::unchecked_cast(*this).synchronized_length());
+        BytecodeArray::unchecked_cast(*this).length(kAcquireLoad));
   }
   if (instance_type == FREE_SPACE_TYPE) {
-    return FreeSpace::unchecked_cast(*this).relaxed_read_size();
+    return FreeSpace::unchecked_cast(*this).size(kRelaxedLoad);
   }
   if (instance_type == STRING_TYPE ||
       instance_type == INTERNALIZED_STRING_TYPE) {
     // Strings may get concurrently truncated, hence we have to access its
     // length synchronized.
     return SeqTwoByteString::SizeFor(
-        SeqTwoByteString::unchecked_cast(*this).synchronized_length());
+        SeqTwoByteString::unchecked_cast(*this).length(kAcquireLoad));
   }
   if (instance_type == FIXED_DOUBLE_ARRAY_TYPE) {
     return FixedDoubleArray::SizeFor(
-        FixedDoubleArray::unchecked_cast(*this).synchronized_length());
+        FixedDoubleArray::unchecked_cast(*this).length(kAcquireLoad));
   }
   if (instance_type == FEEDBACK_METADATA_TYPE) {
     return FeedbackMetadata::SizeFor(
@@ -2287,11 +2305,11 @@ int HeapObject::SizeFromMap(Map map) const {
   if (base::IsInRange(instance_type, FIRST_WEAK_FIXED_ARRAY_TYPE,
                       LAST_WEAK_FIXED_ARRAY_TYPE)) {
     return WeakFixedArray::SizeFor(
-        WeakFixedArray::unchecked_cast(*this).synchronized_length());
+        WeakFixedArray::unchecked_cast(*this).length(kAcquireLoad));
   }
   if (instance_type == WEAK_ARRAY_LIST_TYPE) {
     return WeakArrayList::SizeForCapacity(
-        WeakArrayList::unchecked_cast(*this).synchronized_capacity());
+        WeakArrayList::unchecked_cast(*this).capacity());
   }
   if (instance_type == SMALL_ORDERED_HASH_SET_TYPE) {
     return SmallOrderedHashSet::SizeFor(
@@ -2311,7 +2329,7 @@ int HeapObject::SizeFromMap(Map map) const {
   }
   if (instance_type == PROPERTY_ARRAY_TYPE) {
     return PropertyArray::SizeFor(
-        PropertyArray::cast(*this).synchronized_length());
+        PropertyArray::cast(*this).length(kAcquireLoad));
   }
   if (instance_type == FEEDBACK_VECTOR_TYPE) {
     return FeedbackVector::SizeFor(
@@ -2339,6 +2357,9 @@ int HeapObject::SizeFromMap(Map map) const {
         CoverageInfo::unchecked_cast(*this).slot_count());
   }
 #if V8_ENABLE_WEBASSEMBLY
+  if (instance_type == WASM_STRUCT_TYPE) {
+    return WasmStruct::GcSafeSize(map);
+  }
   if (instance_type == WASM_ARRAY_TYPE) {
     return WasmArray::GcSafeSizeFor(map, WasmArray::cast(*this).length());
   }
@@ -2822,6 +2843,7 @@ Maybe<bool> Object::SetDataProperty(LookupIterator* it, Handle<Object> value) {
 
   Handle<Object> to_assign = value;
   // Convert the incoming value to a number for storing into typed arrays.
+  // TODO(v8:11111): Support RAB / GSAB.
   if (it->IsElement() && receiver->IsJSObject() &&
       JSObject::cast(*receiver).HasTypedArrayElements()) {
     ElementsKind elements_kind = JSObject::cast(*receiver).GetElementsKind();
@@ -2912,8 +2934,9 @@ Maybe<bool> Object::AddDataProperty(LookupIterator* it, Handle<Object> value,
     }
 
     Handle<JSObject> receiver_obj = Handle<JSObject>::cast(receiver);
-    JSObject::AddDataElement(receiver_obj, it->array_index(), value,
-                             attributes);
+    MAYBE_RETURN(JSObject::AddDataElement(receiver_obj, it->array_index(),
+                                          value, attributes),
+                 Nothing<bool>());
     JSObject::ValidateElements(*receiver_obj);
     return Just(true);
   } else {
@@ -3406,10 +3429,13 @@ Maybe<bool> JSArray::ArraySetLength(Isolate* isolate, Handle<JSArray> a,
   }
   // 13. If oldLenDesc.[[Writable]] is false, return false.
   if (!old_len_desc.writable() ||
-      // Also handle the {configurable: true} case since we later use
-      // JSArray::SetLength instead of OrdinaryDefineOwnProperty to change
-      // the length, and it doesn't have access to the descriptor anymore.
-      new_len_desc->configurable()) {
+      // Also handle the {configurable: true} and enumerable changes
+      // since we later use JSArray::SetLength instead of
+      // OrdinaryDefineOwnProperty to change the length,
+      // and it doesn't have access to the descriptor anymore.
+      new_len_desc->configurable() ||
+      (new_len_desc->has_enumerable() &&
+       (old_len_desc.enumerable() != new_len_desc->enumerable()))) {
     RETURN_FAILURE(isolate, GetShouldThrow(isolate, should_throw),
                    NewTypeError(MessageTemplate::kRedefineDisallowed,
                                 isolate->factory()->length_string()));
@@ -3428,7 +3454,7 @@ Maybe<bool> JSArray::ArraySetLength(Isolate* isolate, Handle<JSArray> a,
     // (Not needed.)
   }
   // Most of steps 16 through 19 is implemented by JSArray::SetLength.
-  JSArray::SetLength(a, new_len);
+  MAYBE_RETURN(JSArray::SetLength(a, new_len), Nothing<bool>());
   // Steps 19d-ii, 20.
   if (!new_writable) {
     PropertyDescriptor readonly;
@@ -3966,8 +3992,7 @@ Handle<FixedArray> FixedArray::SetAndGrow(Isolate* isolate,
   do {
     capacity = JSObject::NewElementsCapacity(capacity);
   } while (capacity <= index);
-  Handle<FixedArray> new_array =
-      isolate->factory()->NewUninitializedFixedArray(capacity);
+  Handle<FixedArray> new_array = isolate->factory()->NewFixedArray(capacity);
   array->CopyTo(0, *new_array, 0, array->length());
   new_array->FillWithHoles(array->length(), new_array->length());
   new_array->set(index, *value);
@@ -4336,8 +4361,8 @@ Handle<RegExpMatchInfo> RegExpMatchInfo::ReserveCaptures(
   return result;
 }
 
-template <typename LocalIsolate>
-Handle<DescriptorArray> DescriptorArray::Allocate(LocalIsolate* isolate,
+template <typename IsolateT>
+Handle<DescriptorArray> DescriptorArray::Allocate(IsolateT* isolate,
                                                   int nof_descriptors,
                                                   int slack,
                                                   AllocationType allocation) {
@@ -4551,9 +4576,7 @@ void Relocatable::PostGarbageCollectionProcessing(Isolate* isolate) {
 }
 
 // Reserve space for statics needing saving and restoring.
-int Relocatable::ArchiveSpacePerThread() {
-  return sizeof(Relocatable*);  // NOLINT
-}
+int Relocatable::ArchiveSpacePerThread() { return sizeof(Relocatable*); }
 
 // Archive statics that are thread-local.
 char* Relocatable::ArchiveState(Isolate* isolate, char* to) {
@@ -4720,7 +4743,8 @@ Handle<Object> CacheInitialJSArrayMaps(Isolate* isolate,
   Handle<Map> current_map = initial_map;
   ElementsKind kind = current_map->elements_kind();
   DCHECK_EQ(GetInitialFastElementsKind(), kind);
-  native_context->set(Context::ArrayMapIndex(kind), *current_map);
+  native_context->set(Context::ArrayMapIndex(kind), *current_map,
+                      UPDATE_WRITE_BARRIER, kReleaseStore);
   for (int i = GetSequenceIndexFromFastElementsKind(kind) + 1;
        i < kFastElementsKindCount; ++i) {
     Handle<Map> new_map;
@@ -4733,7 +4757,8 @@ Handle<Object> CacheInitialJSArrayMaps(Isolate* isolate,
                                         INSERT_TRANSITION);
     }
     DCHECK_EQ(next_kind, new_map->elements_kind());
-    native_context->set(Context::ArrayMapIndex(next_kind), *new_map);
+    native_context->set(Context::ArrayMapIndex(next_kind), *new_map,
+                        UPDATE_WRITE_BARRIER, kReleaseStore);
     current_map = new_map;
   }
   return initial_map;
@@ -4783,9 +4808,9 @@ int Script::GetEvalPosition(Isolate* isolate, Handle<Script> script) {
   return position;
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 // static
-void Script::InitLineEnds(LocalIsolate* isolate, Handle<Script> script) {
+void Script::InitLineEnds(IsolateT* isolate, Handle<Script> script) {
   if (!script->line_ends().IsUndefined(isolate)) return;
 #if V8_ENABLE_WEBASSEMBLY
   DCHECK(script->type() != Script::TYPE_WASM ||
@@ -4996,16 +5021,23 @@ Object Script::GetNameOrSourceURL() {
   return name();
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 MaybeHandle<SharedFunctionInfo> Script::FindSharedFunctionInfo(
-    LocalIsolate* isolate, int function_literal_id) {
+    Handle<Script> script, IsolateT* isolate,
+    FunctionLiteral* function_literal) {
+  int function_literal_id = function_literal->function_literal_id();
+  if V8_UNLIKELY (script->type() == Script::TYPE_WEB_SNAPSHOT &&
+                  function_literal_id >= script->shared_function_info_count()) {
+    return FindWebSnapshotSharedFunctionInfo(script, isolate, function_literal);
+  }
+
   CHECK_NE(function_literal_id, kFunctionLiteralIdInvalid);
   // If this check fails, the problem is most probably the function id
   // renumbering done by AstFunctionLiteralIdReindexer; in particular, that
   // AstTraversalVisitor doesn't recurse properly in the construct which
   // triggers the mismatch.
-  CHECK_LT(function_literal_id, shared_function_infos().length());
-  MaybeObject shared = shared_function_infos().Get(function_literal_id);
+  CHECK_LT(function_literal_id, script->shared_function_info_count());
+  MaybeObject shared = script->shared_function_infos().Get(function_literal_id);
   HeapObject heap_object;
   if (!shared->GetHeapObject(&heap_object) ||
       heap_object.IsUndefined(isolate)) {
@@ -5014,9 +5046,81 @@ MaybeHandle<SharedFunctionInfo> Script::FindSharedFunctionInfo(
   return handle(SharedFunctionInfo::cast(heap_object), isolate);
 }
 template MaybeHandle<SharedFunctionInfo> Script::FindSharedFunctionInfo(
-    Isolate* isolate, int function_literal_id);
+    Handle<Script> script, Isolate* isolate, FunctionLiteral* function_literal);
 template MaybeHandle<SharedFunctionInfo> Script::FindSharedFunctionInfo(
-    LocalIsolate* isolate, int function_literal_id);
+    Handle<Script> script, LocalIsolate* isolate,
+    FunctionLiteral* function_literal);
+
+MaybeHandle<SharedFunctionInfo> Script::FindWebSnapshotSharedFunctionInfo(
+    Handle<Script> script, Isolate* isolate,
+    FunctionLiteral* function_literal) {
+  // We might be able to de-dupe the SFI against a SFI that was
+  // created when deserializing the snapshot (or when calling a function which
+  // was included in the snapshot). In that case, we can find it based on the
+  // start position in shared_function_info_table.
+  Handle<ObjectHashTable> shared_function_info_table = handle(
+      ObjectHashTable::cast(script->shared_function_info_table()), isolate);
+  {
+    DisallowHeapAllocation no_gc;
+    Object index_object = shared_function_info_table->Lookup(
+        handle(Smi::FromInt(function_literal->start_position()), isolate));
+    if (!index_object.IsTheHole()) {
+      int index = Smi::cast(index_object).value();
+      DCHECK_LT(index, script->shared_function_info_count());
+      MaybeObject maybe_shared = script->shared_function_infos().Get(index);
+      HeapObject heap_object;
+      if (!maybe_shared->GetHeapObject(&heap_object)) {
+        // We found the correct location but it's not filled in (e.g., the weak
+        // pointer to the SharedFunctionInfo has been cleared). Record the
+        // location in the FunctionLiteral, so that it will be refilled later.
+        // SharedFunctionInfo::SetScript will write the SharedFunctionInfo in
+        // the shared_function_infos.
+        function_literal->set_function_literal_id(index);
+        return MaybeHandle<SharedFunctionInfo>();
+      }
+      SharedFunctionInfo shared = SharedFunctionInfo::cast(heap_object);
+      DCHECK_EQ(shared.StartPosition(), function_literal->start_position());
+      DCHECK_EQ(shared.EndPosition(), function_literal->end_position());
+      return handle(shared, isolate);
+    }
+  }
+
+  // It's possible that FunctionLiterals which were processed before this one
+  // were deduplicated against existing ones. Decrease function_literal_id to
+  // avoid holes in shared_function_infos.
+  int old_length = script->shared_function_info_count();
+  int function_literal_id = old_length;
+  function_literal->set_function_literal_id(function_literal_id);
+
+  // Also add to shared_function_info_table.
+  shared_function_info_table = ObjectHashTable::Put(
+      shared_function_info_table,
+      handle(Smi::FromInt(function_literal->start_position()), isolate),
+      handle(Smi::FromInt(function_literal_id), isolate));
+  script->set_shared_function_info_table(*shared_function_info_table);
+
+  // Grow shared_function_infos if needed (we don't know the correct amount of
+  // space needed upfront).
+  int new_length = old_length + 1;
+  Handle<WeakFixedArray> old_infos =
+      handle(script->shared_function_infos(), isolate);
+  if (new_length > old_infos->length()) {
+    int capacity = WeakArrayList::CapacityForLength(new_length);
+    Handle<WeakFixedArray> new_infos(
+        isolate->factory()->NewWeakFixedArray(capacity, AllocationType::kOld));
+    new_infos->CopyElements(isolate, 0, *old_infos, 0, old_length,
+                            WriteBarrierMode::UPDATE_WRITE_BARRIER);
+    script->set_shared_function_infos(*new_infos);
+  }
+  return MaybeHandle<SharedFunctionInfo>();
+}
+
+MaybeHandle<SharedFunctionInfo> Script::FindWebSnapshotSharedFunctionInfo(
+    Handle<Script> script, LocalIsolate* isolate,
+    FunctionLiteral* function_literal) {
+  // Off-thread serialization of web snapshots is not implemented.
+  UNREACHABLE();
+}
 
 Script::Iterator::Iterator(Isolate* isolate)
     : iterator_(isolate->heap()->script_list()) {}
@@ -5036,13 +5140,13 @@ void JSArray::Initialize(Handle<JSArray> array, int capacity, int length) {
       array, length, capacity, INITIALIZE_ARRAY_ELEMENTS_WITH_HOLE);
 }
 
-void JSArray::SetLength(Handle<JSArray> array, uint32_t new_length) {
+Maybe<bool> JSArray::SetLength(Handle<JSArray> array, uint32_t new_length) {
   // We should never end in here with a pixel or external array.
   DCHECK(array->AllowsSetLength());
   if (array->SetLengthWouldNormalize(new_length)) {
     JSObject::NormalizeElements(array);
   }
-  array->GetElementsAccessor()->SetLength(array, new_length);
+  return array->GetElementsAccessor()->SetLength(array, new_length);
 }
 
 // ES6: 9.5.2 [[SetPrototypeOf]] (V)
@@ -5322,8 +5426,8 @@ Handle<Object> JSPromise::Reject(Handle<JSPromise> promise,
   if (isolate->debug()->is_active()) MoveMessageToPromise(isolate, promise);
 
   if (debug_event) isolate->debug()->OnPromiseReject(promise, reason);
-  isolate->RunPromiseHook(PromiseHookType::kResolve, promise,
-                          isolate->factory()->undefined_value());
+  isolate->RunAllPromiseHooks(PromiseHookType::kResolve, promise,
+                              isolate->factory()->undefined_value());
 
   // 1. Assert: The value of promise.[[PromiseState]] is "pending".
   CHECK_EQ(Promise::kPending, promise->status());
@@ -5358,8 +5462,8 @@ MaybeHandle<Object> JSPromise::Resolve(Handle<JSPromise> promise,
   DCHECK(
       !reinterpret_cast<v8::Isolate*>(isolate)->GetCurrentContext().IsEmpty());
 
-  isolate->RunPromiseHook(PromiseHookType::kResolve, promise,
-                          isolate->factory()->undefined_value());
+  isolate->RunAllPromiseHooks(PromiseHookType::kResolve, promise,
+                              isolate->factory()->undefined_value());
 
   // 7. If SameValue(resolution, promise) is true, then
   if (promise.is_identical_to(resolution)) {
@@ -5508,8 +5612,9 @@ Handle<Object> JSPromise::TriggerPromiseReactions(Isolate* isolate,
         static_cast<int>(
             PromiseReactionJobTask::kSizeOfAllPromiseReactionJobTasks));
     if (type == PromiseReaction::kFulfill) {
-      task->synchronized_set_map(
-          ReadOnlyRoots(isolate).promise_fulfill_reaction_job_task_map());
+      task->set_map(
+          ReadOnlyRoots(isolate).promise_fulfill_reaction_job_task_map(),
+          kReleaseStore);
       Handle<PromiseFulfillReactionJobTask>::cast(task)->set_argument(
           *argument);
       Handle<PromiseFulfillReactionJobTask>::cast(task)->set_context(
@@ -5528,8 +5633,9 @@ Handle<Object> JSPromise::TriggerPromiseReactions(Isolate* isolate,
                                kContinuationPreservedEmbedderDataOffset));
     } else {
       DisallowGarbageCollection no_gc;
-      task->synchronized_set_map(
-          ReadOnlyRoots(isolate).promise_reject_reaction_job_task_map());
+      task->set_map(
+          ReadOnlyRoots(isolate).promise_reject_reaction_job_task_map(),
+          kReleaseStore);
       Handle<PromiseRejectReactionJobTask>::cast(task)->set_argument(*argument);
       Handle<PromiseRejectReactionJobTask>::cast(task)->set_context(
           *handler_context);
@@ -5568,9 +5674,9 @@ void HashTable<Derived, Shape>::IterateElements(ObjectVisitor* v) {
 }
 
 template <typename Derived, typename Shape>
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<Derived> HashTable<Derived, Shape>::New(
-    LocalIsolate* isolate, int at_least_space_for, AllocationType allocation,
+    IsolateT* isolate, int at_least_space_for, AllocationType allocation,
     MinimumCapacity capacity_option) {
   DCHECK_LE(0, at_least_space_for);
   DCHECK_IMPLIES(capacity_option == USE_CUSTOM_MINIMUM_CAPACITY,
@@ -5586,9 +5692,9 @@ Handle<Derived> HashTable<Derived, Shape>::New(
 }
 
 template <typename Derived, typename Shape>
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<Derived> HashTable<Derived, Shape>::NewInternal(
-    LocalIsolate* isolate, int capacity, AllocationType allocation) {
+    IsolateT* isolate, int capacity, AllocationType allocation) {
   auto* factory = isolate->factory();
   int length = EntryToIndex(InternalIndex(capacity));
   Handle<FixedArray> array = factory->NewFixedArrayWithMap(
@@ -5718,9 +5824,9 @@ void HashTable<Derived, Shape>::Rehash(PtrComprCageBase cage_base) {
 }
 
 template <typename Derived, typename Shape>
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<Derived> HashTable<Derived, Shape>::EnsureCapacity(
-    LocalIsolate* isolate, Handle<Derived> table, int n,
+    IsolateT* isolate, Handle<Derived> table, int n,
     AllocationType allocation) {
   if (table->HasSufficientCapacityToAdd(n)) return table;
 
@@ -5851,9 +5957,9 @@ Handle<ObjectHashSet> ObjectHashSet::Add(Isolate* isolate,
 }
 
 template <typename Derived, typename Shape>
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<Derived> BaseNameDictionary<Derived, Shape>::New(
-    LocalIsolate* isolate, int at_least_space_for, AllocationType allocation,
+    IsolateT* isolate, int at_least_space_for, AllocationType allocation,
     MinimumCapacity capacity_option) {
   DCHECK_LE(0, at_least_space_for);
   Handle<Derived> dict = Dictionary<Derived, Shape>::New(
@@ -5925,10 +6031,10 @@ Handle<Derived> Dictionary<Derived, Shape>::AtPut(Isolate* isolate,
 }
 
 template <typename Derived, typename Shape>
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<Derived>
 BaseNameDictionary<Derived, Shape>::AddNoUpdateNextEnumerationIndex(
-    LocalIsolate* isolate, Handle<Derived> dictionary, Key key,
+    IsolateT* isolate, Handle<Derived> dictionary, Key key,
     Handle<Object> value, PropertyDetails details, InternalIndex* entry_out) {
   // Insert element at empty or deleted entry.
   return Dictionary<Derived, Shape>::Add(isolate, dictionary, key, value,
@@ -5954,8 +6060,8 @@ Handle<Derived> BaseNameDictionary<Derived, Shape>::Add(
 }
 
 template <typename Derived, typename Shape>
-template <typename LocalIsolate>
-Handle<Derived> Dictionary<Derived, Shape>::Add(LocalIsolate* isolate,
+template <typename IsolateT>
+Handle<Derived> Dictionary<Derived, Shape>::Add(IsolateT* isolate,
                                                 Handle<Derived> dictionary,
                                                 Key key, Handle<Object> value,
                                                 PropertyDetails details,
@@ -6576,17 +6682,33 @@ AccessCheckInfo AccessCheckInfo::Get(Isolate* isolate,
   return AccessCheckInfo::cast(data_obj);
 }
 
-MaybeHandle<Name> FunctionTemplateInfo::TryGetCachedPropertyName(
-    Isolate* isolate, Handle<Object> getter) {
-  if (getter->IsFunctionTemplateInfo()) {
-    Handle<FunctionTemplateInfo> fti =
-        Handle<FunctionTemplateInfo>::cast(getter);
-    // Check if the accessor uses a cached property.
-    if (!fti->cached_property_name().IsTheHole(isolate)) {
-      return handle(Name::cast(fti->cached_property_name()), isolate);
-    }
-  }
-  return MaybeHandle<Name>();
+base::Optional<Name> FunctionTemplateInfo::TryGetCachedPropertyName(
+    Isolate* isolate, Object getter) {
+  DisallowGarbageCollection no_gc;
+  if (!getter.IsFunctionTemplateInfo()) return {};
+  // Check if the accessor uses a cached property.
+  Object maybe_name = FunctionTemplateInfo::cast(getter).cached_property_name();
+  if (maybe_name.IsTheHole(isolate)) return {};
+  return Name::cast(maybe_name);
+}
+
+int FunctionTemplateInfo::GetCFunctionsCount() const {
+  i::DisallowHeapAllocation no_gc;
+  return FixedArray::cast(GetCFunctionOverloads()).length() /
+         kFunctionOverloadEntrySize;
+}
+
+Address FunctionTemplateInfo::GetCFunction(int index) const {
+  i::DisallowHeapAllocation no_gc;
+  return v8::ToCData<Address>(FixedArray::cast(GetCFunctionOverloads())
+                                  .get(index * kFunctionOverloadEntrySize));
+}
+
+const CFunctionInfo* FunctionTemplateInfo::GetCSignature(int index) const {
+  i::DisallowHeapAllocation no_gc;
+  return v8::ToCData<CFunctionInfo*>(
+      FixedArray::cast(GetCFunctionOverloads())
+          .get(index * kFunctionOverloadEntrySize + 1));
 }
 
 Address Smi::LexicographicCompare(Isolate* isolate, Smi x, Smi y) {
diff --git a/chromium/v8/src/objects/objects.h b/chromium/v8/src/objects/objects.h
index e4532bb0e5e..e80098dfe8d 100644
--- a/chromium/v8/src/objects/objects.h
+++ b/chromium/v8/src/objects/objects.h
@@ -602,7 +602,7 @@ class Object : public TaggedImpl<HeapObjectReferenceType::STRONG, Address> {
   // Prints this object without details to a message accumulator.
   V8_EXPORT_PRIVATE void ShortPrint(StringStream* accumulator) const;
 
-  V8_EXPORT_PRIVATE void ShortPrint(std::ostream& os) const;  // NOLINT
+  V8_EXPORT_PRIVATE void ShortPrint(std::ostream& os) const;
 
   inline static Object cast(Object object) { return object; }
   inline static Object unchecked_cast(Object object) { return object; }
@@ -615,10 +615,10 @@ class Object : public TaggedImpl<HeapObjectReferenceType::STRONG, Address> {
   V8_EXPORT_PRIVATE void Print() const;
 
   // Prints this object with details.
-  V8_EXPORT_PRIVATE void Print(std::ostream& os) const;  // NOLINT
+  V8_EXPORT_PRIVATE void Print(std::ostream& os) const;
 #else
   void Print() const { ShortPrint(); }
-  void Print(std::ostream& os) const { ShortPrint(os); }  // NOLINT
+  void Print(std::ostream& os) const { ShortPrint(os); }
 #endif
 
   // For use with std::unordered_set.
@@ -673,8 +673,7 @@ class Object : public TaggedImpl<HeapObjectReferenceType::STRONG, Address> {
   inline void InitExternalPointerField(size_t offset, Isolate* isolate);
   inline void InitExternalPointerField(size_t offset, Isolate* isolate,
                                        Address value, ExternalPointerTag tag);
-  inline Address ReadExternalPointerField(size_t offset,
-                                          PtrComprCageBase isolate_root,
+  inline Address ReadExternalPointerField(size_t offset, Isolate* isolate,
                                           ExternalPointerTag tag) const;
   inline void WriteExternalPointerField(size_t offset, Isolate* isolate,
                                         Address value, ExternalPointerTag tag);
@@ -778,6 +777,23 @@ class MapWord {
 
   inline Address ptr() { return value_; }
 
+#ifdef V8_MAP_PACKING
+  static constexpr Address Pack(Address map) {
+    return map ^ Internals::kMapWordXorMask;
+  }
+  static constexpr Address Unpack(Address mapword) {
+    // TODO(wenyuzhao): Clear header metadata.
+    return mapword ^ Internals::kMapWordXorMask;
+  }
+  static constexpr bool IsPacked(Address mapword) {
+    return (static_cast<intptr_t>(mapword) & Internals::kMapWordXorMask) ==
+               Internals::kMapWordSignature &&
+           (0xffffffff00000000 & static_cast<intptr_t>(mapword)) != 0;
+  }
+#else
+  static constexpr bool IsPacked(Address) { return false; }
+#endif
+
  private:
   // HeapObject calls the private constructor and directly reads the value.
   friend class HeapObject;
diff --git a/chromium/v8/src/objects/ordered-hash-table.cc b/chromium/v8/src/objects/ordered-hash-table.cc
index a19217878dc..c6754db9378 100644
--- a/chromium/v8/src/objects/ordered-hash-table.cc
+++ b/chromium/v8/src/objects/ordered-hash-table.cc
@@ -16,9 +16,9 @@ namespace v8 {
 namespace internal {
 
 template <class Derived, int entrysize>
-template <typename LocalIsolate>
+template <typename IsolateT>
 MaybeHandle<Derived> OrderedHashTable<Derived, entrysize>::Allocate(
-    LocalIsolate* isolate, int capacity, AllocationType allocation) {
+    IsolateT* isolate, int capacity, AllocationType allocation) {
   // Capacity must be a power of two, since we depend on being able
   // to divide and multiple by 2 (kLoadFactor) to derive capacity
   // from number of buckets. If we decide to change kLoadFactor
@@ -63,9 +63,9 @@ MaybeHandle<Derived> OrderedHashTable<Derived, entrysize>::AllocateEmpty(
 }
 
 template <class Derived, int entrysize>
-template <typename LocalIsolate>
+template <typename IsolateT>
 MaybeHandle<Derived> OrderedHashTable<Derived, entrysize>::EnsureGrowable(
-    LocalIsolate* isolate, Handle<Derived> table) {
+    IsolateT* isolate, Handle<Derived> table) {
   DCHECK(!table->IsObsolete());
 
   int nof = table->NumberOfElements();
@@ -238,17 +238,17 @@ HeapObject OrderedHashMap::GetEmpty(ReadOnlyRoots ro_roots) {
 }
 
 template <class Derived, int entrysize>
-template <typename LocalIsolate>
+template <typename IsolateT>
 MaybeHandle<Derived> OrderedHashTable<Derived, entrysize>::Rehash(
-    LocalIsolate* isolate, Handle<Derived> table) {
+    IsolateT* isolate, Handle<Derived> table) {
   return OrderedHashTable<Derived, entrysize>::Rehash(isolate, table,
                                                       table->Capacity());
 }
 
 template <class Derived, int entrysize>
-template <typename LocalIsolate>
+template <typename IsolateT>
 MaybeHandle<Derived> OrderedHashTable<Derived, entrysize>::Rehash(
-    LocalIsolate* isolate, Handle<Derived> table, int new_capacity) {
+    IsolateT* isolate, Handle<Derived> table, int new_capacity) {
   DCHECK(!table->IsObsolete());
 
   MaybeHandle<Derived> new_table_candidate =
@@ -320,10 +320,9 @@ MaybeHandle<OrderedHashMap> OrderedHashMap::Rehash(Isolate* isolate,
   return Base::Rehash(isolate, table, new_capacity);
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 MaybeHandle<OrderedNameDictionary> OrderedNameDictionary::Rehash(
-    LocalIsolate* isolate, Handle<OrderedNameDictionary> table,
-    int new_capacity) {
+    IsolateT* isolate, Handle<OrderedNameDictionary> table, int new_capacity) {
   MaybeHandle<OrderedNameDictionary> new_table_candidate =
       Base::Rehash(isolate, table, new_capacity);
   Handle<OrderedNameDictionary> new_table;
@@ -407,9 +406,8 @@ MaybeHandle<OrderedHashMap> OrderedHashMap::Add(Isolate* isolate,
   return table;
 }
 
-template <typename LocalIsolate>
-InternalIndex OrderedNameDictionary::FindEntry(LocalIsolate* isolate,
-                                               Object key) {
+template <typename IsolateT>
+InternalIndex OrderedNameDictionary::FindEntry(IsolateT* isolate, Object key) {
   DisallowGarbageCollection no_gc;
 
   DCHECK(key.IsUniqueName());
@@ -438,10 +436,10 @@ InternalIndex OrderedNameDictionary::FindEntry(LocalIsolate* isolate,
   return InternalIndex::NotFound();
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 MaybeHandle<OrderedNameDictionary> OrderedNameDictionary::Add(
-    LocalIsolate* isolate, Handle<OrderedNameDictionary> table,
-    Handle<Name> key, Handle<Object> value, PropertyDetails details) {
+    IsolateT* isolate, Handle<OrderedNameDictionary> table, Handle<Name> key,
+    Handle<Object> value, PropertyDetails details) {
   DCHECK(key->IsUniqueName());
   DCHECK(table->FindEntry(isolate, *key).is_not_found());
 
@@ -505,21 +503,21 @@ Handle<OrderedNameDictionary> OrderedNameDictionary::DeleteEntry(
   return Shrink(isolate, table);
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 MaybeHandle<OrderedHashSet> OrderedHashSet::Allocate(
-    LocalIsolate* isolate, int capacity, AllocationType allocation) {
+    IsolateT* isolate, int capacity, AllocationType allocation) {
   return Base::Allocate(isolate, capacity, allocation);
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 MaybeHandle<OrderedHashMap> OrderedHashMap::Allocate(
-    LocalIsolate* isolate, int capacity, AllocationType allocation) {
+    IsolateT* isolate, int capacity, AllocationType allocation) {
   return Base::Allocate(isolate, capacity, allocation);
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 MaybeHandle<OrderedNameDictionary> OrderedNameDictionary::Allocate(
-    LocalIsolate* isolate, int capacity, AllocationType allocation) {
+    IsolateT* isolate, int capacity, AllocationType allocation) {
   MaybeHandle<OrderedNameDictionary> table_candidate =
       Base::Allocate(isolate, capacity, allocation);
   Handle<OrderedNameDictionary> table;
diff --git a/chromium/v8/src/objects/ordered-hash-table.h b/chromium/v8/src/objects/ordered-hash-table.h
index 1746e2dc896..1110352e46b 100644
--- a/chromium/v8/src/objects/ordered-hash-table.h
+++ b/chromium/v8/src/objects/ordered-hash-table.h
@@ -67,8 +67,8 @@ class OrderedHashTable : public FixedArray {
  public:
   // Returns an OrderedHashTable (possibly |table|) with enough space
   // to add at least one new element.
-  template <typename LocalIsolate>
-  static MaybeHandle<Derived> EnsureGrowable(LocalIsolate* isolate,
+  template <typename IsolateT>
+  static MaybeHandle<Derived> EnsureGrowable(IsolateT* isolate,
                                              Handle<Derived> table);
 
   // Returns an OrderedHashTable (possibly |table|) that's shrunken
@@ -200,21 +200,20 @@ class OrderedHashTable : public FixedArray {
 
  protected:
   // Returns an OrderedHashTable with a capacity of at least |capacity|.
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   static MaybeHandle<Derived> Allocate(
-      LocalIsolate* isolate, int capacity,
+      IsolateT* isolate, int capacity,
       AllocationType allocation = AllocationType::kYoung);
 
   static MaybeHandle<Derived> AllocateEmpty(Isolate* isolate,
                                             AllocationType allocation,
                                             RootIndex root_ndex);
 
-  template <typename LocalIsolate>
-  static MaybeHandle<Derived> Rehash(LocalIsolate* isolate,
-                                     Handle<Derived> table);
-  template <typename LocalIsolate>
-  static MaybeHandle<Derived> Rehash(LocalIsolate* isolate,
-                                     Handle<Derived> table, int new_capacity);
+  template <typename IsolateT>
+  static MaybeHandle<Derived> Rehash(IsolateT* isolate, Handle<Derived> table);
+  template <typename IsolateT>
+  static MaybeHandle<Derived> Rehash(IsolateT* isolate, Handle<Derived> table,
+                                     int new_capacity);
 
   int HashToEntryRaw(int hash) {
     int bucket = HashToBucket(hash);
@@ -287,9 +286,9 @@ class V8_EXPORT_PRIVATE OrderedHashSet
                                             int new_capacity);
   static MaybeHandle<OrderedHashSet> Rehash(Isolate* isolate,
                                             Handle<OrderedHashSet> table);
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   static MaybeHandle<OrderedHashSet> Allocate(
-      LocalIsolate* isolate, int capacity,
+      IsolateT* isolate, int capacity,
       AllocationType allocation = AllocationType::kYoung);
 
   static MaybeHandle<OrderedHashSet> AllocateEmpty(
@@ -318,9 +317,9 @@ class V8_EXPORT_PRIVATE OrderedHashMap
                                          Handle<Object> key,
                                          Handle<Object> value);
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   static MaybeHandle<OrderedHashMap> Allocate(
-      LocalIsolate* isolate, int capacity,
+      IsolateT* isolate, int capacity,
       AllocationType allocation = AllocationType::kYoung);
 
   static MaybeHandle<OrderedHashMap> AllocateEmpty(
@@ -761,24 +760,24 @@ class V8_EXPORT_PRIVATE OrderedNameDictionary
   DECL_CAST(OrderedNameDictionary)
   DECL_PRINTER(OrderedNameDictionary)
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   static MaybeHandle<OrderedNameDictionary> Add(
-      LocalIsolate* isolate, Handle<OrderedNameDictionary> table,
-      Handle<Name> key, Handle<Object> value, PropertyDetails details);
+      IsolateT* isolate, Handle<OrderedNameDictionary> table, Handle<Name> key,
+      Handle<Object> value, PropertyDetails details);
 
   void SetEntry(InternalIndex entry, Object key, Object value,
                 PropertyDetails details);
 
-  template <typename LocalIsolate>
-  InternalIndex FindEntry(LocalIsolate* isolate, Object key);
+  template <typename IsolateT>
+  InternalIndex FindEntry(IsolateT* isolate, Object key);
 
   // This is to make the interfaces of NameDictionary::FindEntry and
   // OrderedNameDictionary::FindEntry compatible.
   // TODO(emrich) clean this up: NameDictionary uses Handle<Object>
   // for FindEntry keys due to its Key typedef, but that's also used
   // for adding, where we do need handles.
-  template <typename LocalIsolate>
-  InternalIndex FindEntry(LocalIsolate* isolate, Handle<Object> key) {
+  template <typename IsolateT>
+  InternalIndex FindEntry(IsolateT* isolate, Handle<Object> key) {
     return FindEntry(isolate, *key);
   }
 
@@ -786,18 +785,17 @@ class V8_EXPORT_PRIVATE OrderedNameDictionary
       Isolate* isolate, Handle<OrderedNameDictionary> table,
       InternalIndex entry);
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   static MaybeHandle<OrderedNameDictionary> Allocate(
-      LocalIsolate* isolate, int capacity,
+      IsolateT* isolate, int capacity,
       AllocationType allocation = AllocationType::kYoung);
 
   static MaybeHandle<OrderedNameDictionary> AllocateEmpty(
       Isolate* isolate, AllocationType allocation = AllocationType::kReadOnly);
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   static MaybeHandle<OrderedNameDictionary> Rehash(
-      LocalIsolate* isolate, Handle<OrderedNameDictionary> table,
-      int new_capacity);
+      IsolateT* isolate, Handle<OrderedNameDictionary> table, int new_capacity);
 
   // Returns the value for entry.
   inline Object ValueAt(InternalIndex entry);
diff --git a/chromium/v8/src/objects/property-array-inl.h b/chromium/v8/src/objects/property-array-inl.h
index fe884b043fd..b51b0d5f2d0 100644
--- a/chromium/v8/src/objects/property-array-inl.h
+++ b/chromium/v8/src/objects/property-array-inl.h
@@ -22,7 +22,8 @@ OBJECT_CONSTRUCTORS_IMPL(PropertyArray, HeapObject)
 CAST_ACCESSOR(PropertyArray)
 
 SMI_ACCESSORS(PropertyArray, length_and_hash, kLengthAndHashOffset)
-SYNCHRONIZED_SMI_ACCESSORS(PropertyArray, length_and_hash, kLengthAndHashOffset)
+RELEASE_ACQUIRE_SMI_ACCESSORS(PropertyArray, length_and_hash,
+                              kLengthAndHashOffset)
 
 Object PropertyArray::get(int index) const {
   PtrComprCageBase cage_base = GetPtrComprCageBase(*this);
@@ -64,8 +65,8 @@ void PropertyArray::initialize_length(int len) {
   set_length_and_hash(len);
 }
 
-int PropertyArray::synchronized_length() const {
-  return LengthField::decode(synchronized_length_and_hash());
+int PropertyArray::length(AcquireLoadTag) const {
+  return LengthField::decode(length_and_hash(kAcquireLoad));
 }
 
 int PropertyArray::Hash() const { return HashField::decode(length_and_hash()); }
diff --git a/chromium/v8/src/objects/property-array.h b/chromium/v8/src/objects/property-array.h
index f4cc5c9fb1c..8ee51982c00 100644
--- a/chromium/v8/src/objects/property-array.h
+++ b/chromium/v8/src/objects/property-array.h
@@ -18,9 +18,7 @@ class PropertyArray : public HeapObject {
  public:
   // [length]: length of the array.
   inline int length() const;
-
-  // Get the length using acquire loads.
-  inline int synchronized_length() const;
+  inline int length(AcquireLoadTag) const;
 
   // This is only used on a newly allocated PropertyArray which
   // doesn't have an existing hash.
@@ -70,7 +68,7 @@ class PropertyArray : public HeapObject {
  private:
   DECL_INT_ACCESSORS(length_and_hash)
 
-  DECL_SYNCHRONIZED_INT_ACCESSORS(length_and_hash)
+  DECL_RELEASE_ACQUIRE_INT_ACCESSORS(length_and_hash)
 
   OBJECT_CONSTRUCTORS(PropertyArray, HeapObject);
 };
diff --git a/chromium/v8/src/objects/scope-info.cc b/chromium/v8/src/objects/scope-info.cc
index 308b57a309d..67a64e873aa 100644
--- a/chromium/v8/src/objects/scope-info.cc
+++ b/chromium/v8/src/objects/scope-info.cc
@@ -57,9 +57,8 @@ bool ScopeInfo::Equals(ScopeInfo other) const {
 #endif
 
 // static
-template <typename LocalIsolate>
-Handle<ScopeInfo> ScopeInfo::Create(LocalIsolate* isolate, Zone* zone,
-                                    Scope* scope,
+template <typename IsolateT>
+Handle<ScopeInfo> ScopeInfo::Create(IsolateT* isolate, Zone* zone, Scope* scope,
                                     MaybeHandle<ScopeInfo> outer_scope) {
   // Collect variables.
   int context_local_count = 0;
@@ -1078,8 +1077,8 @@ std::ostream& operator<<(std::ostream& os, VariableAllocationInfo var_info) {
   return os;
 }
 
-template <typename LocalIsolate>
-Handle<ModuleRequest> ModuleRequest::New(LocalIsolate* isolate,
+template <typename IsolateT>
+Handle<ModuleRequest> ModuleRequest::New(IsolateT* isolate,
                                          Handle<String> specifier,
                                          Handle<FixedArray> import_assertions,
                                          int position) {
@@ -1098,9 +1097,9 @@ template Handle<ModuleRequest> ModuleRequest::New(
     LocalIsolate* isolate, Handle<String> specifier,
     Handle<FixedArray> import_assertions, int position);
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<SourceTextModuleInfoEntry> SourceTextModuleInfoEntry::New(
-    LocalIsolate* isolate, Handle<PrimitiveHeapObject> export_name,
+    IsolateT* isolate, Handle<PrimitiveHeapObject> export_name,
     Handle<PrimitiveHeapObject> local_name,
     Handle<PrimitiveHeapObject> import_name, int module_request, int cell_index,
     int beg_pos, int end_pos) {
@@ -1128,9 +1127,9 @@ template Handle<SourceTextModuleInfoEntry> SourceTextModuleInfoEntry::New(
     Handle<PrimitiveHeapObject> import_name, int module_request, int cell_index,
     int beg_pos, int end_pos);
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<SourceTextModuleInfo> SourceTextModuleInfo::New(
-    LocalIsolate* isolate, Zone* zone, SourceTextModuleDescriptor* descr) {
+    IsolateT* isolate, Zone* zone, SourceTextModuleDescriptor* descr) {
   // Serialize module requests.
   int size = static_cast<int>(descr->module_requests().size());
   Handle<FixedArray> module_requests = isolate->factory()->NewFixedArray(size);
diff --git a/chromium/v8/src/objects/scope-info.h b/chromium/v8/src/objects/scope-info.h
index 57e5d2e308f..c90f6bfed9a 100644
--- a/chromium/v8/src/objects/scope-info.h
+++ b/chromium/v8/src/objects/scope-info.h
@@ -213,19 +213,18 @@ class ScopeInfo : public TorqueGeneratedScopeInfo<ScopeInfo, HeapObject> {
   // closest outer class when resolving private names.
   bool PrivateNameLookupSkipsOuterClass() const;
 
-  // REPL mode scopes allow re-declaraction of let variables. They come from
-  // debug evaluate but are different to IsDebugEvaluateScope().
+  // REPL mode scopes allow re-declaraction of let and const variables. They
+  // come from debug evaluate but are different to IsDebugEvaluateScope().
   bool IsReplModeScope() const;
 
 #ifdef DEBUG
   bool Equals(ScopeInfo other) const;
 #endif
 
-  template <typename LocalIsolate>
-  static Handle<ScopeInfo> Create(LocalIsolate* isolate, Zone* zone,
-                                  Scope* scope,
+  template <typename IsolateT>
+  static Handle<ScopeInfo> Create(IsolateT* isolate, Zone* zone, Scope* scope,
                                   MaybeHandle<ScopeInfo> outer_scope);
-  static Handle<ScopeInfo> CreateForWithScope(
+  V8_EXPORT_PRIVATE static Handle<ScopeInfo> CreateForWithScope(
       Isolate* isolate, MaybeHandle<ScopeInfo> outer_scope);
   V8_EXPORT_PRIVATE static Handle<ScopeInfo> CreateForEmptyFunction(
       Isolate* isolate);
@@ -314,7 +313,7 @@ class ScopeInfo : public TorqueGeneratedScopeInfo<ScopeInfo, HeapObject> {
   }
   static constexpr int ConvertOffsetToIndex(int offset) {
     int index = (offset - HeapObject::kHeaderSize) / kTaggedSize;
-    CONSTEXPR_DCHECK(OffsetOfElementAt(index) == offset);
+    DCHECK_EQ(OffsetOfElementAt(index), offset);
     return index;
   }
 
diff --git a/chromium/v8/src/objects/script-inl.h b/chromium/v8/src/objects/script-inl.h
index b1e226a0465..4dd8bed3824 100644
--- a/chromium/v8/src/objects/script-inl.h
+++ b/chromium/v8/src/objects/script-inl.h
@@ -25,7 +25,7 @@ NEVER_READ_ONLY_SPACE_IMPL(Script)
 
 #if V8_ENABLE_WEBASSEMBLY
 ACCESSORS_CHECKED(Script, wasm_breakpoint_infos, FixedArray,
-                  kEvalFromSharedOrWrappedArgumentsOffset,
+                  kEvalFromSharedOrWrappedArgumentsOrSfiTableOffset,
                   this->type() == TYPE_WASM)
 ACCESSORS_CHECKED(Script, wasm_managed_native_module, Object,
                   kEvalFromPositionOffset, this->type() == TYPE_WASM)
@@ -37,40 +37,59 @@ ACCESSORS_CHECKED(Script, wasm_weak_instance_list, WeakArrayList,
 #endif  // V8_ENABLE_WEBASSEMBLY
 
 SMI_ACCESSORS(Script, type, kScriptTypeOffset)
-ACCESSORS_CHECKED(Script, eval_from_shared_or_wrapped_arguments, Object,
-                  kEvalFromSharedOrWrappedArgumentsOffset,
+ACCESSORS_CHECKED(Script, eval_from_shared_or_wrapped_arguments_or_sfi_table,
+                  Object, kEvalFromSharedOrWrappedArgumentsOrSfiTableOffset,
                   CHECK_SCRIPT_NOT_WASM)
 SMI_ACCESSORS_CHECKED(Script, eval_from_position, kEvalFromPositionOffset,
                       CHECK_SCRIPT_NOT_WASM)
 #undef CHECK_SCRIPT_NOT_WASM
 
 bool Script::is_wrapped() const {
-  return eval_from_shared_or_wrapped_arguments().IsFixedArray();
+  return eval_from_shared_or_wrapped_arguments_or_sfi_table().IsFixedArray() &&
+         type() != TYPE_WEB_SNAPSHOT;
 }
 
 bool Script::has_eval_from_shared() const {
-  return eval_from_shared_or_wrapped_arguments().IsSharedFunctionInfo();
+  return eval_from_shared_or_wrapped_arguments_or_sfi_table()
+      .IsSharedFunctionInfo();
 }
 
 void Script::set_eval_from_shared(SharedFunctionInfo shared,
                                   WriteBarrierMode mode) {
   DCHECK(!is_wrapped());
-  set_eval_from_shared_or_wrapped_arguments(shared, mode);
+  DCHECK_NE(type(), TYPE_WEB_SNAPSHOT);
+  set_eval_from_shared_or_wrapped_arguments_or_sfi_table(shared, mode);
 }
 
 SharedFunctionInfo Script::eval_from_shared() const {
   DCHECK(has_eval_from_shared());
-  return SharedFunctionInfo::cast(eval_from_shared_or_wrapped_arguments());
+  return SharedFunctionInfo::cast(
+      eval_from_shared_or_wrapped_arguments_or_sfi_table());
 }
 
 void Script::set_wrapped_arguments(FixedArray value, WriteBarrierMode mode) {
   DCHECK(!has_eval_from_shared());
-  set_eval_from_shared_or_wrapped_arguments(value, mode);
+  DCHECK_NE(type(), TYPE_WEB_SNAPSHOT);
+  set_eval_from_shared_or_wrapped_arguments_or_sfi_table(value, mode);
 }
 
 FixedArray Script::wrapped_arguments() const {
   DCHECK(is_wrapped());
-  return FixedArray::cast(eval_from_shared_or_wrapped_arguments());
+  return FixedArray::cast(eval_from_shared_or_wrapped_arguments_or_sfi_table());
+}
+
+void Script::set_shared_function_info_table(ObjectHashTable value,
+                                            WriteBarrierMode mode) {
+  DCHECK(!has_eval_from_shared());
+  DCHECK(!is_wrapped());
+  DCHECK_EQ(type(), TYPE_WEB_SNAPSHOT);
+  set_eval_from_shared_or_wrapped_arguments_or_sfi_table(value, mode);
+}
+
+ObjectHashTable Script::shared_function_info_table() const {
+  DCHECK_EQ(type(), TYPE_WEB_SNAPSHOT);
+  return ObjectHashTable::cast(
+      eval_from_shared_or_wrapped_arguments_or_sfi_table());
 }
 
 DEF_GETTER(Script, shared_function_infos, WeakFixedArray) {
@@ -91,6 +110,15 @@ void Script::set_shared_function_infos(WeakFixedArray value,
   CONDITIONAL_WRITE_BARRIER(*this, kSharedFunctionInfosOffset, value, mode);
 }
 
+int Script::shared_function_info_count() const {
+  if V8_UNLIKELY (type() == TYPE_WEB_SNAPSHOT) {
+    // +1 because the 0th element in shared_function_infos is reserved for the
+    // top-level SharedFunctionInfo which doesn't exist.
+    return shared_function_info_table().NumberOfElements() + 1;
+  }
+  return shared_function_infos().length();
+}
+
 #if V8_ENABLE_WEBASSEMBLY
 bool Script::has_wasm_breakpoint_infos() const {
   return type() == TYPE_WASM && wasm_breakpoint_infos().length() > 0;
diff --git a/chromium/v8/src/objects/script.h b/chromium/v8/src/objects/script.h
index e487da76497..3d2ff73b99a 100644
--- a/chromium/v8/src/objects/script.h
+++ b/chromium/v8/src/objects/script.h
@@ -20,6 +20,8 @@ namespace v8 {
 
 namespace internal {
 
+class FunctionLiteral;
+
 #include "torque-generated/src/objects/script-tq.inc"
 
 // Script describes a script which has been added to the VM.
@@ -38,7 +40,8 @@ class Script : public TorqueGeneratedScript<Script, Struct> {
 #if V8_ENABLE_WEBASSEMBLY
     TYPE_WASM = 3,
 #endif  // V8_ENABLE_WEBASSEMBLY
-    TYPE_INSPECTOR = 4
+    TYPE_INSPECTOR = 4,
+    TYPE_WEB_SNAPSHOT = 5
   };
 
   // Script compilation types.
@@ -53,7 +56,7 @@ class Script : public TorqueGeneratedScript<Script, Struct> {
   // [type]: the script type.
   DECL_INT_ACCESSORS(type)
 
-  DECL_ACCESSORS(eval_from_shared_or_wrapped_arguments, Object)
+  DECL_ACCESSORS(eval_from_shared_or_wrapped_arguments_or_sfi_table, Object)
 
   // [eval_from_shared]: for eval scripts the shared function info for the
   // function from which eval was called.
@@ -62,6 +65,12 @@ class Script : public TorqueGeneratedScript<Script, Struct> {
   // [wrapped_arguments]: for the list of arguments in a wrapped script.
   DECL_ACCESSORS(wrapped_arguments, FixedArray)
 
+  // For web snapshots: a hash table mapping function positions to indices in
+  // shared_function_infos.
+  // TODO(v8:11525): Replace with a more efficient data structure mapping
+  // function positions to weak pointers to SharedFunctionInfos directly.
+  DECL_ACCESSORS(shared_function_info_table, ObjectHashTable)
+
   // Whether the script is implicitly wrapped in a function.
   inline bool is_wrapped() const;
 
@@ -78,6 +87,8 @@ class Script : public TorqueGeneratedScript<Script, Struct> {
   // function infos created from this script.
   DECL_ACCESSORS(shared_function_infos, WeakFixedArray)
 
+  inline int shared_function_info_count() const;
+
 #if V8_ENABLE_WEBASSEMBLY
   // [wasm_breakpoint_infos]: the list of {BreakPointInfo} objects describing
   // all WebAssembly breakpoints for modules/instances managed via this script.
@@ -137,9 +148,9 @@ class Script : public TorqueGeneratedScript<Script, Struct> {
   static int GetEvalPosition(Isolate* isolate, Handle<Script> script);
 
   // Init line_ends array with source code positions of line ends.
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-  static void InitLineEnds(LocalIsolate* isolate, Handle<Script> script);
+  static void InitLineEnds(IsolateT* isolate, Handle<Script> script);
 
   // Carries information about a source position.
   struct PositionInfo {
@@ -176,10 +187,19 @@ class Script : public TorqueGeneratedScript<Script, Struct> {
   int GetLineNumber(int code_pos) const;
 
   // Look through the list of existing shared function infos to find one
-  // that matches the function literal.  Return empty handle if not found.
-  template <typename LocalIsolate>
-  MaybeHandle<SharedFunctionInfo> FindSharedFunctionInfo(
-      LocalIsolate* isolate, int function_literal_id);
+  // that matches the function literal. Return empty handle if not found.
+  template <typename IsolateT>
+  static MaybeHandle<SharedFunctionInfo> FindSharedFunctionInfo(
+      Handle<Script> script, IsolateT* isolate,
+      FunctionLiteral* function_literal);
+
+  static MaybeHandle<SharedFunctionInfo> FindWebSnapshotSharedFunctionInfo(
+      Handle<Script> script, Isolate* isolate,
+      FunctionLiteral* function_literal);
+
+  static MaybeHandle<SharedFunctionInfo> FindWebSnapshotSharedFunctionInfo(
+      Handle<Script> script, LocalIsolate* isolate,
+      FunctionLiteral* function_literal);
 
   // Iterate over all script objects on the heap.
   class V8_EXPORT_PRIVATE Iterator {
diff --git a/chromium/v8/src/objects/script.tq b/chromium/v8/src/objects/script.tq
index dac25360cb9..36a70dede58 100644
--- a/chromium/v8/src/objects/script.tq
+++ b/chromium/v8/src/objects/script.tq
@@ -40,8 +40,12 @@ extern class Script extends Struct {
   // [id]: the script id.
   id: Smi;
 
-  eval_from_shared_or_wrapped_arguments: SharedFunctionInfo|FixedArray|
-      Undefined;
+  // For scripts originating from eval: the SharedFunctionInfo contains the SFI
+  // for the script. For scripts wrapped as functions: the FixedArray contains
+  // the arguments. For web snapshots: the ObjectHashTable maps function start
+  // position to SFI index in shared_function_infos.
+  eval_from_shared_or_wrapped_arguments_or_sfi_table: SharedFunctionInfo|
+      FixedArray|ObjectHashTable|Undefined;
   eval_from_position: Smi|Foreign;  // Smi or Managed<wasm::NativeModule>
   shared_function_infos: WeakFixedArray|WeakArrayList;
 
diff --git a/chromium/v8/src/objects/shared-function-info-inl.h b/chromium/v8/src/objects/shared-function-info-inl.h
index c125b01a3d0..3bc0f70572b 100644
--- a/chromium/v8/src/objects/shared-function-info-inl.h
+++ b/chromium/v8/src/objects/shared-function-info-inl.h
@@ -166,8 +166,8 @@ bool SharedFunctionInfo::needs_script_context() const {
   return is_script() && scope_info().ContextLocalCount() > 0;
 }
 
-template <typename LocalIsolate>
-AbstractCode SharedFunctionInfo::abstract_code(LocalIsolate* isolate) {
+template <typename IsolateT>
+AbstractCode SharedFunctionInfo::abstract_code(IsolateT* isolate) {
   // TODO(v8:11429): Decide if this return bytecode or baseline code, when the
   // latter is present.
   if (HasBytecodeArray()) {
@@ -186,9 +186,8 @@ int SharedFunctionInfo::function_token_position() const {
   }
 }
 
-template <typename LocalIsolate>
-bool SharedFunctionInfo::AreSourcePositionsAvailable(
-    LocalIsolate* isolate) const {
+template <typename IsolateT>
+bool SharedFunctionInfo::AreSourcePositionsAvailable(IsolateT* isolate) const {
   if (FLAG_enable_lazy_source_positions) {
     return !HasBytecodeArray() ||
            GetBytecodeArray(isolate).HasSourcePositionTable();
@@ -196,9 +195,9 @@ bool SharedFunctionInfo::AreSourcePositionsAvailable(
   return true;
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 SharedFunctionInfo::Inlineability SharedFunctionInfo::GetInlineability(
-    LocalIsolate* isolate) const {
+    IsolateT* isolate) const {
   if (!script().IsScript()) return kHasNoScript;
 
   if (GetIsolate()->is_precise_binary_code_coverage() &&
@@ -235,9 +234,6 @@ BIT_FIELD_ACCESSORS(SharedFunctionInfo, flags2,
                     has_static_private_methods_or_accessors,
                     SharedFunctionInfo::HasStaticPrivateMethodsOrAccessorsBit)
 
-BIT_FIELD_ACCESSORS(SharedFunctionInfo, flags2, may_have_cached_code,
-                    SharedFunctionInfo::MayHaveCachedCodeBit)
-
 BIT_FIELD_ACCESSORS(SharedFunctionInfo, flags, syntax_kind,
                     SharedFunctionInfo::FunctionSyntaxKindBits)
 
@@ -453,9 +449,8 @@ bool SharedFunctionInfo::is_compiled() const {
          !data.IsUncompiledData();
 }
 
-template <typename LocalIsolate>
-IsCompiledScope SharedFunctionInfo::is_compiled_scope(
-    LocalIsolate* isolate) const {
+template <typename IsolateT>
+IsCompiledScope SharedFunctionInfo::is_compiled_scope(IsolateT* isolate) const {
   return IsCompiledScope(*this, isolate);
 }
 
@@ -497,10 +492,9 @@ bool SharedFunctionInfo::HasBytecodeArray() const {
          data.IsBaselineData();
 }
 
-template <typename LocalIsolate>
-BytecodeArray SharedFunctionInfo::GetBytecodeArray(
-    LocalIsolate* isolate) const {
-  SharedMutexGuardIfOffThread<LocalIsolate, base::kShared> mutex_guard(
+template <typename IsolateT>
+BytecodeArray SharedFunctionInfo::GetBytecodeArray(IsolateT* isolate) const {
+  SharedMutexGuardIfOffThread<IsolateT, base::kShared> mutex_guard(
       GetIsolate()->shared_function_info_access(), isolate);
 
   DCHECK(HasBytecodeArray());
@@ -739,8 +733,8 @@ void SharedFunctionInfo::ClearPreparseData() {
                 UncompiledDataWithPreparseData::kSize);
   STATIC_ASSERT(UncompiledDataWithoutPreparseData::kSize ==
                 UncompiledData::kHeaderSize);
-  data.synchronized_set_map(
-      GetReadOnlyRoots().uncompiled_data_without_preparse_data_map());
+  data.set_map(GetReadOnlyRoots().uncompiled_data_without_preparse_data_map(),
+               kReleaseStore);
 
   // Fill the remaining space with filler.
   heap->CreateFillerObjectAt(
diff --git a/chromium/v8/src/objects/shared-function-info.cc b/chromium/v8/src/objects/shared-function-info.cc
index 5f5917d64a9..054a314f454 100644
--- a/chromium/v8/src/objects/shared-function-info.cc
+++ b/chromium/v8/src/objects/shared-function-info.cc
@@ -431,12 +431,6 @@ std::ostream& operator<<(std::ostream& os, const SourceCodeOf& v) {
   }
 }
 
-MaybeHandle<Code> SharedFunctionInfo::TryGetCachedCode(Isolate* isolate) {
-  if (!may_have_cached_code()) return {};
-  Handle<SharedFunctionInfo> zis(*this, isolate);
-  return isolate->compilation_cache()->LookupCode(zis);
-}
-
 void SharedFunctionInfo::DisableOptimization(BailoutReason reason) {
   DCHECK_NE(reason, BailoutReason::kNoReason);
 
@@ -456,9 +450,9 @@ void SharedFunctionInfo::DisableOptimization(BailoutReason reason) {
 }
 
 // static
-template <typename LocalIsolate>
+template <typename IsolateT>
 void SharedFunctionInfo::InitFromFunctionLiteral(
-    LocalIsolate* isolate, Handle<SharedFunctionInfo> shared_info,
+    IsolateT* isolate, Handle<SharedFunctionInfo> shared_info,
     FunctionLiteral* lit, bool is_toplevel) {
   DCHECK(!shared_info->name_or_scope_info(kAcquireLoad).IsScopeInfo());
 
diff --git a/chromium/v8/src/objects/shared-function-info.h b/chromium/v8/src/objects/shared-function-info.h
index f9db1acbcf7..3ca8a5758d1 100644
--- a/chromium/v8/src/objects/shared-function-info.h
+++ b/chromium/v8/src/objects/shared-function-info.h
@@ -191,8 +191,8 @@ class SharedFunctionInfo
 
   // Get the abstract code associated with the function, which will either be
   // a Code object or a BytecodeArray.
-  template <typename LocalIsolate>
-  inline AbstractCode abstract_code(LocalIsolate* isolate);
+  template <typename IsolateT>
+  inline AbstractCode abstract_code(IsolateT* isolate);
 
   // Tells whether or not this shared function info has an attached
   // BytecodeArray.
@@ -264,9 +264,8 @@ class SharedFunctionInfo
   // Returns an IsCompiledScope which reports whether the function is compiled,
   // and if compiled, will avoid the function becoming uncompiled while it is
   // held.
-  template <typename LocalIsolate>
-  inline IsCompiledScope is_compiled_scope(LocalIsolate* isolate) const;
-
+  template <typename IsolateT>
+  inline IsCompiledScope is_compiled_scope(IsolateT* isolate) const;
 
   // [internal formal parameter count]: The declared number of parameters.
   // For subclass constructors, also includes new.target.
@@ -301,8 +300,8 @@ class SharedFunctionInfo
   inline FunctionTemplateInfo get_api_func_data() const;
   inline void set_api_func_data(FunctionTemplateInfo data);
   inline bool HasBytecodeArray() const;
-  template <typename LocalIsolate>
-  inline BytecodeArray GetBytecodeArray(LocalIsolate* isolate) const;
+  template <typename IsolateT>
+  inline BytecodeArray GetBytecodeArray(IsolateT* isolate) const;
 
   inline void set_bytecode_array(BytecodeArray bytecode);
   inline Code InterpreterTrampoline() const;
@@ -417,15 +416,6 @@ class SharedFunctionInfo
   DECL_BOOLEAN_ACCESSORS(class_scope_has_private_brand)
   DECL_BOOLEAN_ACCESSORS(has_static_private_methods_or_accessors)
 
-  // True if a Code object associated with this SFI has been inserted into the
-  // compilation cache. Note that the cache entry may be removed by aging,
-  // hence the 'may'.
-  DECL_BOOLEAN_ACCESSORS(may_have_cached_code)
-
-  // Returns the cached Code object for this SFI if it exists, an empty handle
-  // otherwise.
-  MaybeHandle<Code> TryGetCachedCode(Isolate* isolate);
-
   // Is this function a top-level function (scripts, evals).
   DECL_BOOLEAN_ACCESSORS(is_toplevel)
 
@@ -557,8 +547,8 @@ class SharedFunctionInfo
     kExceedsBytecodeLimit,
     kMayContainBreakPoints,
   };
-  template <typename LocalIsolate>
-  Inlineability GetInlineability(LocalIsolate* isolate) const;
+  template <typename IsolateT>
+  Inlineability GetInlineability(IsolateT* isolate) const;
 
   // Source size of this function.
   int SourceSize();
@@ -569,8 +559,8 @@ class SharedFunctionInfo
   inline bool has_simple_parameters();
 
   // Initialize a SharedFunctionInfo from a parsed function literal.
-  template <typename LocalIsolate>
-  static void InitFromFunctionLiteral(LocalIsolate* isolate,
+  template <typename IsolateT>
+  static void InitFromFunctionLiteral(IsolateT* isolate,
                                       Handle<SharedFunctionInfo> shared_info,
                                       FunctionLiteral* lit, bool is_toplevel);
 
@@ -587,8 +577,8 @@ class SharedFunctionInfo
   static void EnsureSourcePositionsAvailable(
       Isolate* isolate, Handle<SharedFunctionInfo> shared_info);
 
-  template <typename LocalIsolate>
-  bool AreSourcePositionsAvailable(LocalIsolate* isolate) const;
+  template <typename IsolateT>
+  bool AreSourcePositionsAvailable(IsolateT* isolate) const;
 
   // Hash based on function literal id and script id.
   V8_EXPORT_PRIVATE uint32_t Hash();
diff --git a/chromium/v8/src/objects/shared-function-info.tq b/chromium/v8/src/objects/shared-function-info.tq
index b38598efbb2..3c793efe9b0 100644
--- a/chromium/v8/src/objects/shared-function-info.tq
+++ b/chromium/v8/src/objects/shared-function-info.tq
@@ -49,7 +49,6 @@ bitfield struct SharedFunctionInfoFlags extends uint32 {
 bitfield struct SharedFunctionInfoFlags2 extends uint8 {
   class_scope_has_private_brand: bool: 1 bit;
   has_static_private_methods_or_accessors: bool: 1 bit;
-  may_have_cached_code: bool: 1 bit;
 }
 
 @export
diff --git a/chromium/v8/src/objects/slots-inl.h b/chromium/v8/src/objects/slots-inl.h
index c0d35c525fb..3672df06353 100644
--- a/chromium/v8/src/objects/slots-inl.h
+++ b/chromium/v8/src/objects/slots-inl.h
@@ -10,6 +10,7 @@
 #include "src/common/ptr-compr-inl.h"
 #include "src/objects/compressed-slots.h"
 #include "src/objects/heap-object.h"
+#include "src/objects/map.h"
 #include "src/objects/maybe-object.h"
 #include "src/objects/objects.h"
 #include "src/objects/slots.h"
@@ -29,12 +30,32 @@ bool FullObjectSlot::contains_value(Address raw_value) const {
   return base::AsAtomicPointer::Relaxed_Load(location()) == raw_value;
 }
 
+bool FullObjectSlot::contains_map_value(Address raw_value) const {
+  return load_map().ptr() == raw_value;
+}
+
 Object FullObjectSlot::operator*() const { return Object(*location()); }
 
 Object FullObjectSlot::load(PtrComprCageBase cage_base) const { return **this; }
 
 void FullObjectSlot::store(Object value) const { *location() = value.ptr(); }
 
+void FullObjectSlot::store_map(Map map) const {
+#ifdef V8_MAP_PACKING
+  *location() = MapWord::Pack(map.ptr());
+#else
+  store(map);
+#endif
+}
+
+Map FullObjectSlot::load_map() const {
+#ifdef V8_MAP_PACKING
+  return Map::unchecked_cast(Object(MapWord::Unpack(*location())));
+#else
+  return Map::unchecked_cast(Object(*location()));
+#endif
+}
+
 Object FullObjectSlot::Acquire_Load() const {
   return Object(base::AsAtomicPointer::Acquire_Load(location()));
 }
diff --git a/chromium/v8/src/objects/slots.h b/chromium/v8/src/objects/slots.h
index 69c6a8a80bc..59b44d49b05 100644
--- a/chromium/v8/src/objects/slots.h
+++ b/chromium/v8/src/objects/slots.h
@@ -108,10 +108,14 @@ class FullObjectSlot : public SlotBase<FullObjectSlot, Address> {
   // Compares memory representation of a value stored in the slot with given
   // raw value.
   inline bool contains_value(Address raw_value) const;
+  inline bool contains_map_value(Address raw_value) const;
 
   inline Object operator*() const;
   inline Object load(PtrComprCageBase cage_base) const;
   inline void store(Object value) const;
+  inline void store_map(Map map) const;
+
+  inline Map load_map() const;
 
   inline Object Acquire_Load() const;
   inline Object Acquire_Load(PtrComprCageBase cage_base) const;
diff --git a/chromium/v8/src/objects/smi.h b/chromium/v8/src/objects/smi.h
index 44cd5f7446e..cc99d8f7d08 100644
--- a/chromium/v8/src/objects/smi.h
+++ b/chromium/v8/src/objects/smi.h
@@ -26,7 +26,7 @@ class Smi : public Object {
   // in that we want them to be constexprs.
   constexpr Smi() : Object() {}
   explicit constexpr Smi(Address ptr) : Object(ptr) {
-    CONSTEXPR_DCHECK(HAS_SMI_TAG(ptr));
+    DCHECK(HAS_SMI_TAG(ptr));
   }
 
   // Returns the integer value.
@@ -43,7 +43,7 @@ class Smi : public Object {
 
   // Convert a value to a Smi object.
   static inline constexpr Smi FromInt(int value) {
-    CONSTEXPR_DCHECK(Smi::IsValid(value));
+    DCHECK(Smi::IsValid(value));
     return Smi(Internals::IntToSmi(value));
   }
 
@@ -69,8 +69,8 @@ class Smi : public Object {
 
   // Returns whether value can be represented in a Smi.
   static inline bool constexpr IsValid(intptr_t value) {
-    CONSTEXPR_DCHECK(Internals::IsValidSmi(value) ==
-                     (value >= kMinValue && value <= kMaxValue));
+    DCHECK_EQ(Internals::IsValidSmi(value),
+              value >= kMinValue && value <= kMaxValue);
     return Internals::IsValidSmi(value);
   }
 
@@ -87,7 +87,7 @@ class Smi : public Object {
   DECL_CAST(Smi)
 
   // Dispatched behavior.
-  V8_EXPORT_PRIVATE void SmiPrint(std::ostream& os) const;  // NOLINT
+  V8_EXPORT_PRIVATE void SmiPrint(std::ostream& os) const;
   DECL_VERIFIER(Smi)
 
   // Since this is a constexpr, "calling" it is just as efficient
diff --git a/chromium/v8/src/objects/source-text-module.cc b/chromium/v8/src/objects/source-text-module.cc
index a905444da5f..755f826a87a 100644
--- a/chromium/v8/src/objects/source-text-module.cc
+++ b/chromium/v8/src/objects/source-text-module.cc
@@ -672,13 +672,13 @@ Handle<JSModuleNamespace> SourceTextModule::GetModuleNamespace(
 
 MaybeHandle<JSObject> SourceTextModule::GetImportMeta(
     Isolate* isolate, Handle<SourceTextModule> module) {
-  Handle<HeapObject> import_meta(module->import_meta(), isolate);
+  Handle<HeapObject> import_meta(module->import_meta(kAcquireLoad), isolate);
   if (import_meta->IsTheHole(isolate)) {
     if (!isolate->RunHostInitializeImportMetaObjectCallback(module).ToHandle(
             &import_meta)) {
       return {};
     }
-    module->set_import_meta(*import_meta);
+    module->set_import_meta(*import_meta, kReleaseStore);
   }
   return Handle<JSObject>::cast(import_meta);
 }
@@ -1181,7 +1181,7 @@ void SourceTextModule::Reset(Isolate* isolate,
                              Handle<SourceTextModule> module) {
   Factory* factory = isolate->factory();
 
-  DCHECK(module->import_meta().IsTheHole(isolate));
+  DCHECK(module->import_meta(kAcquireLoad).IsTheHole(isolate));
 
   Handle<FixedArray> regular_exports =
       factory->NewFixedArray(module->regular_exports().length());
diff --git a/chromium/v8/src/objects/source-text-module.h b/chromium/v8/src/objects/source-text-module.h
index 873a0cd7299..6f2a3cd0f72 100644
--- a/chromium/v8/src/objects/source-text-module.h
+++ b/chromium/v8/src/objects/source-text-module.h
@@ -219,8 +219,8 @@ class SourceTextModuleInfo : public FixedArray {
  public:
   DECL_CAST(SourceTextModuleInfo)
 
-  template <typename LocalIsolate>
-  static Handle<SourceTextModuleInfo> New(LocalIsolate* isolate, Zone* zone,
+  template <typename IsolateT>
+  static Handle<SourceTextModuleInfo> New(IsolateT* isolate, Zone* zone,
                                           SourceTextModuleDescriptor* descr);
 
   inline FixedArray module_requests() const;
@@ -267,9 +267,8 @@ class ModuleRequest
   NEVER_READ_ONLY_SPACE
   DECL_VERIFIER(ModuleRequest)
 
-  template <typename LocalIsolate>
-  static Handle<ModuleRequest> New(LocalIsolate* isolate,
-                                   Handle<String> specifier,
+  template <typename IsolateT>
+  static Handle<ModuleRequest> New(IsolateT* isolate, Handle<String> specifier,
                                    Handle<FixedArray> import_assertions,
                                    int position);
 
@@ -287,9 +286,9 @@ class SourceTextModuleInfoEntry
   DECL_PRINTER(SourceTextModuleInfoEntry)
   DECL_VERIFIER(SourceTextModuleInfoEntry)
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   static Handle<SourceTextModuleInfoEntry> New(
-      LocalIsolate* isolate, Handle<PrimitiveHeapObject> export_name,
+      IsolateT* isolate, Handle<PrimitiveHeapObject> export_name,
       Handle<PrimitiveHeapObject> local_name,
       Handle<PrimitiveHeapObject> import_name, int module_request,
       int cell_index, int beg_pos, int end_pos);
diff --git a/chromium/v8/src/objects/source-text-module.tq b/chromium/v8/src/objects/source-text-module.tq
index 5a21807cc5a..a3d565c908f 100644
--- a/chromium/v8/src/objects/source-text-module.tq
+++ b/chromium/v8/src/objects/source-text-module.tq
@@ -29,7 +29,7 @@ extern class SourceTextModule extends Module {
   // The value of import.meta inside of this module.
   // Lazily initialized on first access. It's the hole before first access and
   // a JSObject afterwards.
-  import_meta: TheHole|JSObject;
+  @cppAcquireLoad @cppReleaseStore import_meta: TheHole|JSObject;
 
   // The first visited module of a cycle. For modules not in a cycle, this is
   // the module itself. It's the hole before the module state transitions to
diff --git a/chromium/v8/src/objects/string-inl.h b/chromium/v8/src/objects/string-inl.h
index 912109b2e0a..8b71536d8f5 100644
--- a/chromium/v8/src/objects/string-inl.h
+++ b/chromium/v8/src/objects/string-inl.h
@@ -92,12 +92,12 @@ class V8_NODISCARD SharedStringAccessGuardIfNeeded {
   base::Optional<base::SharedMutexGuard<base::kShared>> mutex_guard;
 };
 
-int String::synchronized_length() const {
+int String::length(AcquireLoadTag) const {
   return base::AsAtomic32::Acquire_Load(
       reinterpret_cast<const int32_t*>(field_address(kLengthOffset)));
 }
 
-void String::synchronized_set_length(int value) {
+void String::set_length(int value, ReleaseStoreTag) {
   base::AsAtomic32::Release_Store(
       reinterpret_cast<int32_t*>(field_address(kLengthOffset)), value);
 }
@@ -119,7 +119,7 @@ CAST_ACCESSOR(ExternalString)
 CAST_ACCESSOR(ExternalTwoByteString)
 
 StringShape::StringShape(const String str)
-    : type_(str.synchronized_map().instance_type()) {
+    : type_(str.map(kAcquireLoad).instance_type()) {
   set_valid();
   DCHECK_EQ(type_ & kIsNotStringMask, kStringTag);
 }
@@ -335,8 +335,8 @@ class SequentialStringKey final : public StringTableKey {
         chars_(chars),
         convert_(convert) {}
 
-  template <typename LocalIsolate>
-  bool IsMatch(LocalIsolate* isolate, String s) {
+  template <typename IsolateT>
+  bool IsMatch(IsolateT* isolate, String s) {
     return s.IsEqualTo<String::EqualityType::kNoLengthCheck>(chars_, isolate);
   }
 
@@ -827,10 +827,10 @@ void SeqTwoByteString::SeqTwoByteStringSet(int index, uint16_t value) {
 // Due to ThinString rewriting, concurrent visitors need to read the length with
 // acquire semantics.
 inline int SeqOneByteString::AllocatedSize() {
-  return SizeFor(synchronized_length());
+  return SizeFor(length(kAcquireLoad));
 }
 inline int SeqTwoByteString::AllocatedSize() {
-  return SizeFor(synchronized_length());
+  return SizeFor(length(kAcquireLoad));
 }
 
 void SlicedString::set_parent(String parent, WriteBarrierMode mode) {
@@ -862,7 +862,8 @@ void ExternalString::AllocateExternalPointerEntries(Isolate* isolate) {
 }
 
 DEF_GETTER(ExternalString, resource_as_address, Address) {
-  return ReadExternalPointerField(kResourceOffset, cage_base,
+  Isolate* isolate = GetIsolateForHeapSandbox(*this);
+  return ReadExternalPointerField(kResourceOffset, isolate,
                                   kExternalStringResourceTag);
 }
 
diff --git a/chromium/v8/src/objects/string-table.cc b/chromium/v8/src/objects/string-table.cc
index a5493761162..cd554e02202 100644
--- a/chromium/v8/src/objects/string-table.cc
+++ b/chromium/v8/src/objects/string-table.cc
@@ -69,8 +69,8 @@ int ComputeStringTableCapacityWithShrink(int current_capacity,
   return new_capacity;
 }
 
-template <typename LocalIsolate, typename StringTableKey>
-bool KeyIsMatch(LocalIsolate* isolate, StringTableKey* key, String string) {
+template <typename IsolateT, typename StringTableKey>
+bool KeyIsMatch(IsolateT* isolate, StringTableKey* key, String string) {
   if (string.hash() != key->hash()) return false;
   if (string.length() != key->length()) return false;
   return key->IsMatch(isolate, string);
@@ -135,15 +135,15 @@ class StringTable::Data {
   int number_of_elements() const { return number_of_elements_; }
   int number_of_deleted_elements() const { return number_of_deleted_elements_; }
 
-  template <typename LocalIsolate, typename StringTableKey>
-  InternalIndex FindEntry(LocalIsolate* isolate, StringTableKey* key,
+  template <typename IsolateT, typename StringTableKey>
+  InternalIndex FindEntry(IsolateT* isolate, StringTableKey* key,
                           uint32_t hash) const;
 
   InternalIndex FindInsertionEntry(PtrComprCageBase cage_base,
                                    uint32_t hash) const;
 
-  template <typename LocalIsolate, typename StringTableKey>
-  InternalIndex FindEntryOrInsertionEntry(LocalIsolate* isolate,
+  template <typename IsolateT, typename StringTableKey>
+  InternalIndex FindEntryOrInsertionEntry(IsolateT* isolate,
                                           StringTableKey* key,
                                           uint32_t hash) const;
 
@@ -249,8 +249,8 @@ std::unique_ptr<StringTable::Data> StringTable::Data::Resize(
   return new_data;
 }
 
-template <typename LocalIsolate, typename StringTableKey>
-InternalIndex StringTable::Data::FindEntry(LocalIsolate* isolate,
+template <typename IsolateT, typename StringTableKey>
+InternalIndex StringTable::Data::FindEntry(IsolateT* isolate,
                                            StringTableKey* key,
                                            uint32_t hash) const {
   uint32_t count = 1;
@@ -281,9 +281,9 @@ InternalIndex StringTable::Data::FindInsertionEntry(PtrComprCageBase cage_base,
   }
 }
 
-template <typename LocalIsolate, typename StringTableKey>
+template <typename IsolateT, typename StringTableKey>
 InternalIndex StringTable::Data::FindEntryOrInsertionEntry(
-    LocalIsolate* isolate, StringTableKey* key, uint32_t hash) const {
+    IsolateT* isolate, StringTableKey* key, uint32_t hash) const {
   InternalIndex insertion_entry = InternalIndex::NotFound();
   uint32_t count = 1;
   // EnsureCapacity will guarantee the hash table is never full.
@@ -428,9 +428,8 @@ Handle<String> StringTable::LookupString(Isolate* isolate,
   return result;
 }
 
-template <typename StringTableKey, typename LocalIsolate>
-Handle<String> StringTable::LookupKey(LocalIsolate* isolate,
-                                      StringTableKey* key) {
+template <typename StringTableKey, typename IsolateT>
+Handle<String> StringTable::LookupKey(IsolateT* isolate, StringTableKey* key) {
   // String table lookups are allowed to be concurrent, assuming that:
   //
   //   - The Heap access is allowed to be concurrent (using LocalHeap or
diff --git a/chromium/v8/src/objects/string-table.h b/chromium/v8/src/objects/string-table.h
index fe87ce15f2b..fc630f156ca 100644
--- a/chromium/v8/src/objects/string-table.h
+++ b/chromium/v8/src/objects/string-table.h
@@ -63,8 +63,8 @@ class V8_EXPORT_PRIVATE StringTable {
   // Find string in the string table, using the given key. If the string is not
   // there yet, it is created (by the key) and added. The return value is the
   // string found.
-  template <typename StringTableKey, typename LocalIsolate>
-  Handle<String> LookupKey(LocalIsolate* isolate, StringTableKey* key);
+  template <typename StringTableKey, typename IsolateT>
+  Handle<String> LookupKey(IsolateT* isolate, StringTableKey* key);
 
   // {raw_string} must be a tagged String pointer.
   // Returns a tagged pointer: either a Smi if the string is an array index, an
diff --git a/chromium/v8/src/objects/string.cc b/chromium/v8/src/objects/string.cc
index ffa1be3aa34..52bb9679a54 100644
--- a/chromium/v8/src/objects/string.cc
+++ b/chromium/v8/src/objects/string.cc
@@ -127,7 +127,7 @@ void String::MakeThin(Isolate* isolate, String internalized) {
   ThinString thin = ThinString::unchecked_cast(*this);
   thin.set_actual(internalized);
   DCHECK_GE(old_size, ThinString::kSize);
-  this->synchronized_set_map(*map);
+  this->set_map(*map, kReleaseStore);
   Address thin_end = thin.address() + ThinString::kSize;
   int size_delta = old_size - ThinString::kSize;
   if (size_delta != 0) {
@@ -200,7 +200,7 @@ bool String::MakeExternal(v8::String::ExternalStringResource* resource) {
 
   // We are storing the new map using release store after creating a filler for
   // the left-over space to avoid races with the sweeper thread.
-  this->synchronized_set_map(new_map);
+  this->set_map(new_map, kReleaseStore);
 
   ExternalTwoByteString self = ExternalTwoByteString::cast(*this);
   self.AllocateExternalPointerEntries(isolate);
@@ -277,7 +277,7 @@ bool String::MakeExternal(v8::String::ExternalOneByteStringResource* resource) {
 
   // We are storing the new map using release store after creating a filler for
   // the left-over space to avoid races with the sweeper thread.
-  this->synchronized_set_map(new_map);
+  this->set_map(new_map, kReleaseStore);
 
   ExternalOneByteString self = ExternalOneByteString::cast(*this);
   self.AllocateExternalPointerEntries(isolate);
@@ -374,7 +374,7 @@ void String::StringShortPrint(StringStream* accumulator) {
   accumulator->Put('>');
 }
 
-void String::PrintUC16(std::ostream& os, int start, int end) {  // NOLINT
+void String::PrintUC16(std::ostream& os, int start, int end) {
   if (end < 0) end = length();
   StringCharacterStream stream(*this, start);
   for (int i = start; i < end && stream.HasMore(); i++) {
@@ -735,8 +735,8 @@ static void CalculateLineEndsImpl(std::vector<int>* line_ends,
   }
 }
 
-template <typename LocalIsolate>
-Handle<FixedArray> String::CalculateLineEnds(LocalIsolate* isolate,
+template <typename IsolateT>
+Handle<FixedArray> String::CalculateLineEnds(IsolateT* isolate,
                                              Handle<String> src,
                                              bool include_ending_line) {
   src = Flatten(isolate, src);
@@ -1425,7 +1425,7 @@ Handle<String> SeqString::Truncate(Handle<SeqString> string, int new_length) {
                              ClearRecordedSlots::kNo);
   // We are storing the new length using release store after creating a filler
   // for the left-over space to avoid races with the sweeper thread.
-  string->synchronized_set_length(new_length);
+  string->set_length(new_length, kReleaseStore);
 
   return string;
 }
diff --git a/chromium/v8/src/objects/string.h b/chromium/v8/src/objects/string.h
index b8d47b5551f..b873a069ada 100644
--- a/chromium/v8/src/objects/string.h
+++ b/chromium/v8/src/objects/string.h
@@ -194,9 +194,10 @@ class String : public TorqueGeneratedString<String, Name> {
   const byte* AddressOfCharacterAt(int start_index,
                                    const DisallowGarbageCollection& no_gc);
 
-  // Get and set the length of the string using acquire loads and release
-  // stores.
-  DECL_SYNCHRONIZED_INT_ACCESSORS(length)
+  // Forward declare the non-atomic (set_)length defined in torque.
+  using TorqueGeneratedString::length;
+  using TorqueGeneratedString::set_length;
+  DECL_RELEASE_ACQUIRE_INT_ACCESSORS(length)
 
   // Returns whether this string has only one-byte chars, i.e. all of them can
   // be one-byte encoded.  This might be the case even if the string is
@@ -409,7 +410,7 @@ class String : public TorqueGeneratedString<String, Name> {
   const char* PrefixForDebugPrint() const;
   const char* SuffixForDebugPrint() const;
   void StringShortPrint(StringStream* accumulator);
-  void PrintUC16(std::ostream& os, int start = 0, int end = -1);  // NOLINT
+  void PrintUC16(std::ostream& os, int start = 0, int end = -1);
   void PrintUC16(StringStream* accumulator, int start, int end);
 
   // Dispatched behavior.
@@ -530,8 +531,8 @@ class String : public TorqueGeneratedString<String, Name> {
       Visitor* visitor, String string, int offset,
       const SharedStringAccessGuardIfNeeded& access_guard);
 
-  template <typename LocalIsolate>
-  static Handle<FixedArray> CalculateLineEnds(LocalIsolate* isolate,
+  template <typename IsolateT>
+  static Handle<FixedArray> CalculateLineEnds(IsolateT* isolate,
                                               Handle<String> string,
                                               bool include_ending_line);
 
diff --git a/chromium/v8/src/objects/struct-inl.h b/chromium/v8/src/objects/struct-inl.h
index b313bc43f89..b062660fd1b 100644
--- a/chromium/v8/src/objects/struct-inl.h
+++ b/chromium/v8/src/objects/struct-inl.h
@@ -28,13 +28,6 @@ NEVER_READ_ONLY_SPACE_IMPL(AccessorPair)
 
 TQ_OBJECT_CONSTRUCTORS_IMPL(ClassPositions)
 
-void Struct::InitializeBody(int object_size) {
-  Object value = GetReadOnlyRoots().undefined_value();
-  for (int offset = kHeaderSize; offset < object_size; offset += kTaggedSize) {
-    WRITE_FIELD(*this, offset, value);
-  }
-}
-
 Object AccessorPair::get(AccessorComponent component) {
   return component == ACCESSOR_GETTER ? getter() : setter();
 }
diff --git a/chromium/v8/src/objects/struct.h b/chromium/v8/src/objects/struct.h
index fa4fe42b620..ca0dcf4ac10 100644
--- a/chromium/v8/src/objects/struct.h
+++ b/chromium/v8/src/objects/struct.h
@@ -21,7 +21,6 @@ namespace internal {
 // identified in the type system.
 class Struct : public TorqueGeneratedStruct<Struct, HeapObject> {
  public:
-  inline void InitializeBody(int object_size);
   void BriefPrintDetails(std::ostream& os);
   STATIC_ASSERT(kHeaderSize == HeapObject::kHeaderSize);
 
diff --git a/chromium/v8/src/objects/swiss-name-dictionary-inl.h b/chromium/v8/src/objects/swiss-name-dictionary-inl.h
index 343abfc8cc3..770c32b59f9 100644
--- a/chromium/v8/src/objects/swiss-name-dictionary-inl.h
+++ b/chromium/v8/src/objects/swiss-name-dictionary-inl.h
@@ -89,7 +89,7 @@ constexpr int SwissNameDictionary::CtrlTableSize(int capacity) {
 
 // static
 constexpr int SwissNameDictionary::SizeFor(int capacity) {
-  CONSTEXPR_DCHECK(IsValidCapacity(capacity));
+  DCHECK(IsValidCapacity(capacity));
   return PropertyDetailsTableStartOffset(capacity) + capacity;
 }
 
@@ -98,7 +98,7 @@ constexpr int SwissNameDictionary::SizeFor(int capacity) {
 // Similar to Abseil's CapacityToGrowth.
 // static
 constexpr int SwissNameDictionary::MaxUsableCapacity(int capacity) {
-  CONSTEXPR_DCHECK(IsValidCapacity(capacity));
+  DCHECK(IsValidCapacity(capacity));
 
   if (Group::kWidth == 8 && capacity == 4) {
     // If the group size is 16 we can fully utilize capacity 4: There will be
@@ -146,9 +146,8 @@ void SwissNameDictionary::SetEntryForEnumerationIndex(int enumeration_index,
                     entry);
 }
 
-template <typename LocalIsolate>
-InternalIndex SwissNameDictionary::FindEntry(LocalIsolate* isolate,
-                                             Object key) {
+template <typename IsolateT>
+InternalIndex SwissNameDictionary::FindEntry(IsolateT* isolate, Object key) {
   Name name = Name::cast(key);
   DCHECK(name.IsUniqueName());
   uint32_t hash = name.hash();
@@ -212,8 +211,8 @@ InternalIndex SwissNameDictionary::FindEntry(LocalIsolate* isolate,
   }
 }
 
-template <typename LocalIsolate>
-InternalIndex SwissNameDictionary::FindEntry(LocalIsolate* isolate,
+template <typename IsolateT>
+InternalIndex SwissNameDictionary::FindEntry(IsolateT* isolate,
                                              Handle<Object> key) {
   return FindEntry(isolate, *key);
 }
@@ -318,9 +317,9 @@ PropertyDetails SwissNameDictionary::DetailsAt(InternalIndex entry) {
 }
 
 // static
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<SwissNameDictionary> SwissNameDictionary::EnsureGrowable(
-    LocalIsolate* isolate, Handle<SwissNameDictionary> table) {
+    IsolateT* isolate, Handle<SwissNameDictionary> table) {
   int capacity = table->Capacity();
 
   if (table->UsedCapacity() < MaxUsableCapacity(capacity)) {
@@ -444,7 +443,7 @@ int SwissNameDictionary::GetMetaTableField(ByteArray meta_table,
 }
 
 constexpr int SwissNameDictionary::MetaTableSizePerEntryFor(int capacity) {
-  CONSTEXPR_DCHECK(IsValidCapacity(capacity));
+  DCHECK(IsValidCapacity(capacity));
 
   // See the STATIC_ASSERTs on |kMax1ByteMetaTableCapacity| and
   // |kMax2ByteMetaTableCapacity| in the .cc file for an explanation of these
@@ -459,7 +458,7 @@ constexpr int SwissNameDictionary::MetaTableSizePerEntryFor(int capacity) {
 }
 
 constexpr int SwissNameDictionary::MetaTableSizeFor(int capacity) {
-  CONSTEXPR_DCHECK(IsValidCapacity(capacity));
+  DCHECK(IsValidCapacity(capacity));
 
   int per_entry_size = MetaTableSizePerEntryFor(capacity);
 
@@ -488,9 +487,9 @@ bool SwissNameDictionary::ToKey(ReadOnlyRoots roots, InternalIndex entry,
 }
 
 // static
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<SwissNameDictionary> SwissNameDictionary::Add(
-    LocalIsolate* isolate, Handle<SwissNameDictionary> original_table,
+    IsolateT* isolate, Handle<SwissNameDictionary> original_table,
     Handle<Name> key, Handle<Object> value, PropertyDetails details,
     InternalIndex* entry_out) {
   DCHECK(original_table->FindEntry(isolate, *key).is_not_found());
@@ -538,9 +537,9 @@ int SwissNameDictionary::AddInternal(Name key, Object value,
   return target;
 }
 
-template <typename LocalIsolate>
-void SwissNameDictionary::Initialize(LocalIsolate* isolate,
-                                     ByteArray meta_table, int capacity) {
+template <typename IsolateT>
+void SwissNameDictionary::Initialize(IsolateT* isolate, ByteArray meta_table,
+                                     int capacity) {
   DCHECK(IsValidCapacity(capacity));
   DisallowHeapAllocation no_gc;
   ReadOnlyRoots roots(isolate);
@@ -564,7 +563,7 @@ void SwissNameDictionary::Initialize(LocalIsolate* isolate,
 SwissNameDictionary::IndexIterator::IndexIterator(
     Handle<SwissNameDictionary> dict, int start)
     : enum_index_{start}, dict_{dict} {
-  if (!COMPRESS_POINTERS_BOOL && dict.is_null()) {
+  if (!COMPRESS_POINTERS_IN_ISOLATE_CAGE_BOOL && dict.is_null()) {
     used_capacity_ = 0;
   } else {
     used_capacity_ = dict->UsedCapacity();
@@ -609,7 +608,7 @@ SwissNameDictionary::IndexIterator SwissNameDictionary::IndexIterable::begin() {
 }
 
 SwissNameDictionary::IndexIterator SwissNameDictionary::IndexIterable::end() {
-  if (!COMPRESS_POINTERS_BOOL && dict_.is_null()) {
+  if (!COMPRESS_POINTERS_IN_ISOLATE_CAGE_BOOL && dict_.is_null()) {
     return IndexIterator(dict_, 0);
   } else {
     DCHECK(!dict_.is_null());
@@ -620,12 +619,12 @@ SwissNameDictionary::IndexIterator SwissNameDictionary::IndexIterable::end() {
 SwissNameDictionary::IndexIterable
 SwissNameDictionary::IterateEntriesOrdered() {
   // If we are supposed to iterate the empty dictionary (which is non-writable)
-  // and pointer compression is disabled, we have no simple way to get the
-  // isolate, which we would need to create a handle.
+  // and pointer compression with a per-Isolate cage is disabled, we have no
+  // simple way to get the isolate, which we would need to create a handle.
   // TODO(emrich): Consider always using roots.empty_swiss_dictionary_handle()
   // in the condition once this function gets Isolate as a parameter in order to
   // avoid empty dict checks.
-  if (!COMPRESS_POINTERS_BOOL && Capacity() == 0)
+  if (!COMPRESS_POINTERS_IN_ISOLATE_CAGE_BOOL && Capacity() == 0)
     return IndexIterable(Handle<SwissNameDictionary>::null());
 
   Isolate* isolate;
@@ -661,7 +660,7 @@ constexpr int SwissNameDictionary::MaxCapacity() {
       sizeof(uint32_t);
 
   int result = (FixedArray::kMaxSize - const_size) / per_entry_size;
-  CONSTEXPR_DCHECK(result <= Smi::kMaxValue);
+  DCHECK_GE(Smi::kMaxValue, result);
 
   return result;
 }
diff --git a/chromium/v8/src/objects/swiss-name-dictionary.cc b/chromium/v8/src/objects/swiss-name-dictionary.cc
index 5b567aeaeed..57038ca41d9 100644
--- a/chromium/v8/src/objects/swiss-name-dictionary.cc
+++ b/chromium/v8/src/objects/swiss-name-dictionary.cc
@@ -37,10 +37,9 @@ Handle<SwissNameDictionary> SwissNameDictionary::DeleteEntry(
 }
 
 // static
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<SwissNameDictionary> SwissNameDictionary::Rehash(
-    LocalIsolate* isolate, Handle<SwissNameDictionary> table,
-    int new_capacity) {
+    IsolateT* isolate, Handle<SwissNameDictionary> table, int new_capacity) {
   DCHECK(IsValidCapacity(new_capacity));
   DCHECK_LE(table->NumberOfElements(), MaxUsableCapacity(new_capacity));
   ReadOnlyRoots roots(isolate);
diff --git a/chromium/v8/src/objects/swiss-name-dictionary.h b/chromium/v8/src/objects/swiss-name-dictionary.h
index 9ab225dd349..afafb83dd28 100644
--- a/chromium/v8/src/objects/swiss-name-dictionary.h
+++ b/chromium/v8/src/objects/swiss-name-dictionary.h
@@ -72,10 +72,10 @@ class V8_EXPORT_PRIVATE SwissNameDictionary : public HeapObject {
  public:
   using Group = swiss_table::Group;
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   inline static Handle<SwissNameDictionary> Add(
-      LocalIsolate* isolate, Handle<SwissNameDictionary> table,
-      Handle<Name> key, Handle<Object> value, PropertyDetails details,
+      IsolateT* isolate, Handle<SwissNameDictionary> table, Handle<Name> key,
+      Handle<Object> value, PropertyDetails details,
       InternalIndex* entry_out = nullptr);
 
   static Handle<SwissNameDictionary> Shrink(Isolate* isolate,
@@ -84,16 +84,16 @@ class V8_EXPORT_PRIVATE SwissNameDictionary : public HeapObject {
   static Handle<SwissNameDictionary> DeleteEntry(
       Isolate* isolate, Handle<SwissNameDictionary> table, InternalIndex entry);
 
-  template <typename LocalIsolate>
-  inline InternalIndex FindEntry(LocalIsolate* isolate, Object key);
+  template <typename IsolateT>
+  inline InternalIndex FindEntry(IsolateT* isolate, Object key);
 
   // This is to make the interfaces of NameDictionary::FindEntry and
   // OrderedNameDictionary::FindEntry compatible.
   // TODO(emrich) clean this up: NameDictionary uses Handle<Object>
   // for FindEntry keys due to its Key typedef, but that's also used
   // for adding, where we do need handles.
-  template <typename LocalIsolate>
-  inline InternalIndex FindEntry(LocalIsolate* isolate, Handle<Object> key);
+  template <typename IsolateT>
+  inline InternalIndex FindEntry(IsolateT* isolate, Handle<Object> key);
 
   static inline bool IsKey(ReadOnlyRoots roots, Object key_candidate);
   inline bool ToKey(ReadOnlyRoots roots, InternalIndex entry, Object* out_key);
@@ -123,11 +123,11 @@ class V8_EXPORT_PRIVATE SwissNameDictionary : public HeapObject {
   // deleted entries (which reside in initialized memory, but are not compared).
   bool EqualsForTesting(SwissNameDictionary other);
 
-  template <typename LocalIsolate>
-  void Initialize(LocalIsolate* isolate, ByteArray meta_table, int capacity);
+  template <typename IsolateT>
+  void Initialize(IsolateT* isolate, ByteArray meta_table, int capacity);
 
-  template <typename LocalIsolate>
-  static Handle<SwissNameDictionary> Rehash(LocalIsolate* isolate,
+  template <typename IsolateT>
+  static Handle<SwissNameDictionary> Rehash(IsolateT* isolate,
                                             Handle<SwissNameDictionary> table,
                                             int new_capacity);
   void Rehash(Isolate* isolate);
@@ -262,9 +262,9 @@ class V8_EXPORT_PRIVATE SwissNameDictionary : public HeapObject {
   using ctrl_t = swiss_table::ctrl_t;
   using Ctrl = swiss_table::Ctrl;
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   inline static Handle<SwissNameDictionary> EnsureGrowable(
-      LocalIsolate* isolate, Handle<SwissNameDictionary> table);
+      IsolateT* isolate, Handle<SwissNameDictionary> table);
 
   // Returns table of byte-encoded PropertyDetails (without enumeration index
   // stored in PropertyDetails).
diff --git a/chromium/v8/src/objects/tagged-field-inl.h b/chromium/v8/src/objects/tagged-field-inl.h
index 513f6a02d97..5c3a18982e3 100644
--- a/chromium/v8/src/objects/tagged-field-inl.h
+++ b/chromium/v8/src/objects/tagged-field-inl.h
@@ -56,6 +56,7 @@ Tagged_t TaggedField<T, kFieldOffset>::full_to_tagged(Address value) {
 template <typename T, int kFieldOffset>
 T TaggedField<T, kFieldOffset>::load(HeapObject host, int offset) {
   Tagged_t value = *location(host, offset);
+  DCHECK_NE(kFieldOffset + offset, HeapObject::kMapOffset);
   return T(tagged_to_full(host.ptr(), value));
 }
 
@@ -64,6 +65,7 @@ template <typename T, int kFieldOffset>
 T TaggedField<T, kFieldOffset>::load(PtrComprCageBase cage_base,
                                      HeapObject host, int offset) {
   Tagged_t value = *location(host, offset);
+  DCHECK_NE(kFieldOffset + offset, HeapObject::kMapOffset);
   return T(tagged_to_full(cage_base, value));
 }
 
@@ -73,7 +75,9 @@ void TaggedField<T, kFieldOffset>::store(HeapObject host, T value) {
 #ifdef V8_ATOMIC_OBJECT_FIELD_WRITES
   Relaxed_Store(host, value);
 #else
-  *location(host) = full_to_tagged(value.ptr());
+  Address ptr = value.ptr();
+  DCHECK_NE(kFieldOffset, HeapObject::kMapOffset);
+  *location(host) = full_to_tagged(ptr);
 #endif
 }
 
@@ -83,7 +87,9 @@ void TaggedField<T, kFieldOffset>::store(HeapObject host, int offset, T value) {
 #ifdef V8_ATOMIC_OBJECT_FIELD_WRITES
   Relaxed_Store(host, offset, value);
 #else
-  *location(host, offset) = full_to_tagged(value.ptr());
+  Address ptr = value.ptr();
+  DCHECK_NE(kFieldOffset + offset, HeapObject::kMapOffset);
+  *location(host, offset) = full_to_tagged(ptr);
 #endif
 }
 
@@ -91,6 +97,7 @@ void TaggedField<T, kFieldOffset>::store(HeapObject host, int offset, T value) {
 template <typename T, int kFieldOffset>
 T TaggedField<T, kFieldOffset>::Relaxed_Load(HeapObject host, int offset) {
   AtomicTagged_t value = AsAtomicTagged::Relaxed_Load(location(host, offset));
+  DCHECK_NE(kFieldOffset + offset, HeapObject::kMapOffset);
   return T(tagged_to_full(host.ptr(), value));
 }
 
@@ -99,50 +106,89 @@ template <typename T, int kFieldOffset>
 T TaggedField<T, kFieldOffset>::Relaxed_Load(PtrComprCageBase cage_base,
                                              HeapObject host, int offset) {
   AtomicTagged_t value = AsAtomicTagged::Relaxed_Load(location(host, offset));
+  DCHECK_NE(kFieldOffset + offset, HeapObject::kMapOffset);
   return T(tagged_to_full(cage_base, value));
 }
 
 // static
 template <typename T, int kFieldOffset>
-void TaggedField<T, kFieldOffset>::Relaxed_Store(HeapObject host, T value) {
+T TaggedField<T, kFieldOffset>::Relaxed_Load_Map_Word(
+    PtrComprCageBase cage_base, HeapObject host) {
+  AtomicTagged_t value = AsAtomicTagged::Relaxed_Load(location(host, 0));
+  return T(tagged_to_full(cage_base, value));
+}
+
+// static
+template <typename T, int kFieldOffset>
+void TaggedField<T, kFieldOffset>::Relaxed_Store_Map_Word(HeapObject host,
+                                                          T value) {
   AsAtomicTagged::Relaxed_Store(location(host), full_to_tagged(value.ptr()));
 }
 
 // static
 template <typename T, int kFieldOffset>
+void TaggedField<T, kFieldOffset>::Relaxed_Store(HeapObject host, T value) {
+  Address ptr = value.ptr();
+  DCHECK_NE(kFieldOffset, HeapObject::kMapOffset);
+  AsAtomicTagged::Relaxed_Store(location(host), full_to_tagged(ptr));
+}
+
+// static
+template <typename T, int kFieldOffset>
 void TaggedField<T, kFieldOffset>::Relaxed_Store(HeapObject host, int offset,
                                                  T value) {
-  AsAtomicTagged::Relaxed_Store(location(host, offset),
-                                full_to_tagged(value.ptr()));
+  Address ptr = value.ptr();
+  DCHECK_NE(kFieldOffset + offset, HeapObject::kMapOffset);
+  AsAtomicTagged::Relaxed_Store(location(host, offset), full_to_tagged(ptr));
 }
 
 // static
 template <typename T, int kFieldOffset>
 T TaggedField<T, kFieldOffset>::Acquire_Load(HeapObject host, int offset) {
   AtomicTagged_t value = AsAtomicTagged::Acquire_Load(location(host, offset));
+  DCHECK_NE(kFieldOffset + offset, HeapObject::kMapOffset);
   return T(tagged_to_full(host.ptr(), value));
 }
 
 // static
 template <typename T, int kFieldOffset>
+T TaggedField<T, kFieldOffset>::Acquire_Load_No_Unpack(
+    PtrComprCageBase cage_base, HeapObject host, int offset) {
+  AtomicTagged_t value = AsAtomicTagged::Acquire_Load(location(host, offset));
+  return T(tagged_to_full(cage_base, value));
+}
+
+template <typename T, int kFieldOffset>
 T TaggedField<T, kFieldOffset>::Acquire_Load(PtrComprCageBase cage_base,
                                              HeapObject host, int offset) {
   AtomicTagged_t value = AsAtomicTagged::Acquire_Load(location(host, offset));
+  DCHECK_NE(kFieldOffset + offset, HeapObject::kMapOffset);
   return T(tagged_to_full(cage_base, value));
 }
 
 // static
 template <typename T, int kFieldOffset>
 void TaggedField<T, kFieldOffset>::Release_Store(HeapObject host, T value) {
-  AsAtomicTagged::Release_Store(location(host), full_to_tagged(value.ptr()));
+  Address ptr = value.ptr();
+  DCHECK_NE(kFieldOffset, HeapObject::kMapOffset);
+  AsAtomicTagged::Release_Store(location(host), full_to_tagged(ptr));
+}
+
+// static
+template <typename T, int kFieldOffset>
+void TaggedField<T, kFieldOffset>::Release_Store_Map_Word(HeapObject host,
+                                                          T value) {
+  Address ptr = value.ptr();
+  AsAtomicTagged::Release_Store(location(host), full_to_tagged(ptr));
 }
 
 // static
 template <typename T, int kFieldOffset>
 void TaggedField<T, kFieldOffset>::Release_Store(HeapObject host, int offset,
                                                  T value) {
-  AsAtomicTagged::Release_Store(location(host, offset),
-                                full_to_tagged(value.ptr()));
+  Address ptr = value.ptr();
+  DCHECK_NE(kFieldOffset + offset, HeapObject::kMapOffset);
+  AsAtomicTagged::Release_Store(location(host, offset), full_to_tagged(ptr));
 }
 
 // static
diff --git a/chromium/v8/src/objects/tagged-field.h b/chromium/v8/src/objects/tagged-field.h
index e3950fa0af3..d9fc0bb1027 100644
--- a/chromium/v8/src/objects/tagged-field.h
+++ b/chromium/v8/src/objects/tagged-field.h
@@ -52,6 +52,8 @@ class TaggedField : public AllStatic {
   static inline void Relaxed_Store(HeapObject host, int offset, T value);
 
   static inline T Acquire_Load(HeapObject host, int offset = 0);
+  static inline T Acquire_Load_No_Unpack(PtrComprCageBase cage_base,
+                                         HeapObject host, int offset = 0);
   static inline T Acquire_Load(PtrComprCageBase cage_base, HeapObject host,
                                int offset = 0);
 
@@ -61,6 +63,13 @@ class TaggedField : public AllStatic {
   static inline Tagged_t Release_CompareAndSwap(HeapObject host, T old,
                                                 T value);
 
+  // Note: Use these *_Map_Word methods only when loading a MapWord from a
+  // MapField.
+  static inline T Relaxed_Load_Map_Word(PtrComprCageBase cage_base,
+                                        HeapObject host);
+  static inline void Relaxed_Store_Map_Word(HeapObject host, T value);
+  static inline void Release_Store_Map_Word(HeapObject host, T value);
+
  private:
   static inline Tagged_t* location(HeapObject host, int offset = 0);
 
diff --git a/chromium/v8/src/objects/tagged-impl.h b/chromium/v8/src/objects/tagged-impl.h
index 9ef8b58d991..e7278a12451 100644
--- a/chromium/v8/src/objects/tagged-impl.h
+++ b/chromium/v8/src/objects/tagged-impl.h
@@ -88,8 +88,7 @@ class TaggedImpl {
 
   // Returns true if this tagged value is a strong pointer to a HeapObject.
   constexpr inline bool IsStrong() const {
-    CONSTEXPR_DCHECK(kCanBeWeak ||
-                     (!IsSmi() == HAS_STRONG_HEAP_OBJECT_TAG(ptr_)));
+    DCHECK(kCanBeWeak || (!IsSmi() == HAS_STRONG_HEAP_OBJECT_TAG(ptr_)));
     return kCanBeWeak ? HAS_STRONG_HEAP_OBJECT_TAG(ptr_) : !IsSmi();
   }
 
diff --git a/chromium/v8/src/objects/tagged-index.h b/chromium/v8/src/objects/tagged-index.h
index e8cfbc76087..19812877cb7 100644
--- a/chromium/v8/src/objects/tagged-index.h
+++ b/chromium/v8/src/objects/tagged-index.h
@@ -38,7 +38,7 @@ class TaggedIndex : public Object {
   // special in that we want them to be constexprs.
   constexpr TaggedIndex() : Object() {}
   explicit constexpr TaggedIndex(Address ptr) : Object(ptr) {
-    CONSTEXPR_DCHECK(HAS_SMI_TAG(ptr));
+    DCHECK(HAS_SMI_TAG(ptr));
   }
 
   // Returns the integer value.
@@ -49,7 +49,7 @@ class TaggedIndex : public Object {
 
   // Convert a value to a TaggedIndex object.
   static inline TaggedIndex FromIntptr(intptr_t value) {
-    CONSTEXPR_DCHECK(TaggedIndex::IsValid(value));
+    DCHECK(TaggedIndex::IsValid(value));
     return TaggedIndex((static_cast<Address>(value) << kSmiTagSize) | kSmiTag);
   }
 
diff --git a/chromium/v8/src/objects/templates-inl.h b/chromium/v8/src/objects/templates-inl.h
index d5a08fd88eb..d2d50762463 100644
--- a/chromium/v8/src/objects/templates-inl.h
+++ b/chromium/v8/src/objects/templates-inl.h
@@ -34,34 +34,10 @@ BOOL_ACCESSORS(FunctionTemplateInfo, flag, read_only_prototype,
                ReadOnlyPrototypeBit::kShift)
 BOOL_ACCESSORS(FunctionTemplateInfo, flag, remove_prototype,
                RemovePrototypeBit::kShift)
-BOOL_ACCESSORS(FunctionTemplateInfo, flag, do_not_cache, DoNotCacheBit::kShift)
 BOOL_ACCESSORS(FunctionTemplateInfo, flag, accept_any_receiver,
                AcceptAnyReceiverBit::kShift)
 BOOL_ACCESSORS(FunctionTemplateInfo, flag, published, PublishedBit::kShift)
 
-// TODO(nicohartmann@, v8:11122): Let Torque generate this accessor.
-RELEASE_ACQUIRE_ACCESSORS(FunctionTemplateInfo, call_code, HeapObject,
-                          kCallCodeOffset)
-
-// TODO(nicohartmann@, v8:11122): Let Torque generate this accessor.
-HeapObject FunctionTemplateInfo::rare_data(AcquireLoadTag) const {
-  PtrComprCageBase cage_base = GetPtrComprCageBase(*this);
-  return rare_data(cage_base, kAcquireLoad);
-}
-HeapObject FunctionTemplateInfo::rare_data(PtrComprCageBase cage_base,
-                                           AcquireLoadTag) const {
-  HeapObject value =
-      TaggedField<HeapObject>::Acquire_Load(cage_base, *this, kRareDataOffset);
-  DCHECK(value.IsUndefined() || value.IsFunctionTemplateRareData());
-  return value;
-}
-void FunctionTemplateInfo::set_rare_data(HeapObject value, ReleaseStoreTag,
-                                         WriteBarrierMode mode) {
-  DCHECK(value.IsUndefined() || value.IsFunctionTemplateRareData());
-  RELEASE_WRITE_FIELD(*this, kRareDataOffset, value);
-  CONDITIONAL_WRITE_BARRIER(*this, kRareDataOffset, value, mode);
-}
-
 // static
 FunctionTemplateRareData FunctionTemplateInfo::EnsureFunctionTemplateRareData(
     Isolate* isolate, Handle<FunctionTemplateInfo> function_template_info) {
@@ -100,10 +76,15 @@ RARE_ACCESSORS(instance_template, InstanceTemplate, HeapObject, undefined)
 RARE_ACCESSORS(instance_call_handler, InstanceCallHandler, HeapObject,
                undefined)
 RARE_ACCESSORS(access_check_info, AccessCheckInfo, HeapObject, undefined)
-RARE_ACCESSORS(c_function, CFunction, Object, Smi(0))
-RARE_ACCESSORS(c_signature, CSignature, Object, Smi(0))
+RARE_ACCESSORS(c_function_overloads, CFunctionOverloads, FixedArray,
+               GetReadOnlyRoots(cage_base).empty_fixed_array())
 #undef RARE_ACCESSORS
 
+bool TemplateInfo::should_cache() const {
+  return serial_number() != kDoNotCache;
+}
+bool TemplateInfo::is_cached() const { return serial_number() > kUncached; }
+
 bool FunctionTemplateInfo::instantiated() {
   return shared_function_info().IsSharedFunctionInfo();
 }
diff --git a/chromium/v8/src/objects/templates.h b/chromium/v8/src/objects/templates.h
index 966b81167c4..b2401734323 100644
--- a/chromium/v8/src/objects/templates.h
+++ b/chromium/v8/src/objects/templates.h
@@ -12,6 +12,9 @@
 #include "src/objects/object-macros.h"
 
 namespace v8 {
+
+class CFunctionInfo;
+
 namespace internal {
 
 #include "torque-generated/src/objects/templates-tq.inc"
@@ -27,6 +30,16 @@ class TemplateInfo : public TorqueGeneratedTemplateInfo<TemplateInfo, Struct> {
   // instead of caching them.
   static const int kSlowTemplateInstantiationsCacheSize = 1 * MB;
 
+  // If the serial number is set to kDoNotCache, then we should never cache this
+  // TemplateInfo.
+  static const int kDoNotCache = -1;
+  // If the serial number is set to kUncached, it means that this TemplateInfo
+  // has not been cached yet but it can be.
+  static const int kUncached = -2;
+
+  inline bool should_cache() const;
+  inline bool is_cached() const;
+
   TQ_OBJECT_CONSTRUCTORS(TemplateInfo)
 };
 
@@ -35,6 +48,7 @@ class FunctionTemplateRareData
     : public TorqueGeneratedFunctionTemplateRareData<FunctionTemplateRareData,
                                                      Struct> {
  public:
+  DECL_VERIFIER(FunctionTemplateRareData)
   TQ_OBJECT_CONSTRUCTORS(FunctionTemplateRareData)
 };
 
@@ -83,20 +97,9 @@ class FunctionTemplateInfo
 
   DECL_RARE_ACCESSORS(access_check_info, AccessCheckInfo, HeapObject)
 
-  DECL_RARE_ACCESSORS(c_function, CFunction, Object)
-  DECL_RARE_ACCESSORS(c_signature, CSignature, Object)
+  DECL_RARE_ACCESSORS(c_function_overloads, CFunctionOverloads, FixedArray)
 #undef DECL_RARE_ACCESSORS
 
-  // TODO(nicohartmann@, v8:11122): Let Torque generate the following accessor.
-  DECL_RELEASE_ACQUIRE_ACCESSORS(call_code, HeapObject)
-
-  // TODO(nicohartmann@, v8:11122): Let Torque generate the following accessor.
-  inline HeapObject rare_data(AcquireLoadTag) const;
-  inline HeapObject rare_data(PtrComprCageBase cage_base, AcquireLoadTag) const;
-  inline void set_rare_data(
-      HeapObject value, ReleaseStoreTag,
-      WriteBarrierMode mode = WriteBarrierMode::UPDATE_WRITE_BARRIER);
-
   // Begin flag bits ---------------------
   DECL_BOOLEAN_ACCESSORS(undetectable)
 
@@ -111,10 +114,6 @@ class FunctionTemplateInfo
   // prototype_provoider_template are instantiated.
   DECL_BOOLEAN_ACCESSORS(remove_prototype)
 
-  // If set, do not attach a serial number to this FunctionTemplate and thus do
-  // not keep an instance boilerplate around.
-  DECL_BOOLEAN_ACCESSORS(do_not_cache)
-
   // If not set an access may be performed on calling the associated JSFunction.
   DECL_BOOLEAN_ACCESSORS(accept_any_receiver)
 
@@ -128,8 +127,6 @@ class FunctionTemplateInfo
   // Dispatched behavior.
   DECL_PRINTER(FunctionTemplateInfo)
 
-  static const int kInvalidSerialNumber = 0;
-
   static Handle<SharedFunctionInfo> GetOrCreateSharedFunctionInfo(
       Isolate* isolate, Handle<FunctionTemplateInfo> info,
       MaybeHandle<Name> maybe_name);
@@ -146,14 +143,26 @@ class FunctionTemplateInfo
   inline FunctionTemplateInfo GetParent(Isolate* isolate);
   // Returns true if |object| is an instance of this function template.
   inline bool IsTemplateFor(JSObject object);
-  bool IsTemplateFor(Map map);
+  bool IsTemplateFor(Map map) const;
+  // Returns true if |object| is an API object and is constructed by this
+  // particular function template (skips walking up the chain of inheriting
+  // functions that is done by IsTemplateFor).
+  bool IsLeafTemplateForApiObject(Object object) const;
   inline bool instantiated();
 
   inline bool BreakAtEntry();
 
   // Helper function for cached accessors.
-  static MaybeHandle<Name> TryGetCachedPropertyName(Isolate* isolate,
-                                                    Handle<Object> getter);
+  static base::Optional<Name> TryGetCachedPropertyName(Isolate* isolate,
+                                                       Object getter);
+  // Fast API overloads.
+  int GetCFunctionsCount() const;
+  Address GetCFunction(int index) const;
+  const CFunctionInfo* GetCSignature(int index) const;
+
+  // CFunction data for a set of overloads is stored into a FixedArray, as
+  // [address_0, signature_0, ... address_n-1, signature_n-1].
+  static const int kFunctionOverloadEntrySize = 2;
 
   // Bit position in the flag, from least significant bit position.
   DEFINE_TORQUE_GENERATED_FUNCTION_TEMPLATE_INFO_FLAGS()
diff --git a/chromium/v8/src/objects/templates.tq b/chromium/v8/src/objects/templates.tq
index e952747ecf7..1dec706d490 100644
--- a/chromium/v8/src/objects/templates.tq
+++ b/chromium/v8/src/objects/templates.tq
@@ -24,8 +24,7 @@ extern class FunctionTemplateRareData extends Struct {
   instance_template: ObjectTemplateInfo|Undefined;
   instance_call_handler: CallHandlerInfo|Undefined;
   access_check_info: AccessCheckInfo|Undefined;
-  c_function: Foreign|Zero;
-  c_signature: Foreign|Zero;
+  c_function_overloads: FixedArray;
 }
 
 bitfield struct FunctionTemplateInfoFlags extends uint31 {
@@ -33,7 +32,6 @@ bitfield struct FunctionTemplateInfoFlags extends uint31 {
   needs_access_check: bool: 1 bit;
   read_only_prototype: bool: 1 bit;
   remove_prototype: bool: 1 bit;
-  do_not_cache: bool: 1 bit;
   accept_any_receiver: bool: 1 bit;
   published: bool: 1 bit;
 }
@@ -42,7 +40,7 @@ bitfield struct FunctionTemplateInfoFlags extends uint31 {
 extern class FunctionTemplateInfo extends TemplateInfo {
   // Handler invoked when calling an instance of this FunctionTemplateInfo.
   // Either CallHandlerInfo or Undefined.
-  call_code: CallHandlerInfo|Undefined;
+  @cppAcquireLoad @cppReleaseStore call_code: CallHandlerInfo|Undefined;
   class_name: String|Undefined;
   // If the signature is a FunctionTemplateInfo it is used to check whether the
   // receiver calling the associated JSFunction is a compatible receiver, i.e.
@@ -52,6 +50,8 @@ extern class FunctionTemplateInfo extends TemplateInfo {
   // If any of the setters declared by DECL_RARE_ACCESSORS are used then a
   // FunctionTemplateRareData will be stored here. Until then this contains
   // undefined.
+  @cppAcquireLoad
+  @cppReleaseStore
   rare_data: FunctionTemplateRareData|Undefined;
   shared_function_info: SharedFunctionInfo|Undefined;
   // Internal field to store a flag bitfield.
diff --git a/chromium/v8/src/objects/torque-defined-classes.h b/chromium/v8/src/objects/torque-defined-classes.h
index aeea4e1c536..4273d347117 100644
--- a/chromium/v8/src/objects/torque-defined-classes.h
+++ b/chromium/v8/src/objects/torque-defined-classes.h
@@ -7,6 +7,7 @@
 #include "src/objects/descriptor-array.h"
 #include "src/objects/fixed-array.h"
 #include "src/objects/heap-object.h"
+#include "src/objects/megadom-handler.h"
 #include "src/objects/objects.h"
 
 // Has to be the last include (doesn't have include guards):
diff --git a/chromium/v8/src/objects/transitions.cc b/chromium/v8/src/objects/transitions.cc
index ac908030a2d..a8bf5bbde0c 100644
--- a/chromium/v8/src/objects/transitions.cc
+++ b/chromium/v8/src/objects/transitions.cc
@@ -510,7 +510,7 @@ void TransitionsAccessor::EnsureHasFullTransitionArray() {
 }
 
 void TransitionsAccessor::TraverseTransitionTreeInternal(
-    TraverseCallback callback, void* data, DisallowGarbageCollection* no_gc) {
+    TraverseCallback callback, DisallowGarbageCollection* no_gc) {
   switch (encoding()) {
     case kPrototypeInfo:
     case kUninitialized:
@@ -520,7 +520,7 @@ void TransitionsAccessor::TraverseTransitionTreeInternal(
       Map simple_target =
           Map::cast(raw_transitions_->GetHeapObjectAssumeWeak());
       TransitionsAccessor(isolate_, simple_target, no_gc)
-          .TraverseTransitionTreeInternal(callback, data, no_gc);
+          .TraverseTransitionTreeInternal(callback, no_gc);
       break;
     }
     case kFullTransitionArray: {
@@ -533,7 +533,7 @@ void TransitionsAccessor::TraverseTransitionTreeInternal(
           HeapObject heap_object;
           if (target->GetHeapObjectIfWeak(&heap_object)) {
             TransitionsAccessor(isolate_, Map::cast(heap_object), no_gc)
-                .TraverseTransitionTreeInternal(callback, data, no_gc);
+                .TraverseTransitionTreeInternal(callback, no_gc);
           } else {
             DCHECK(target->IsCleared());
           }
@@ -541,12 +541,12 @@ void TransitionsAccessor::TraverseTransitionTreeInternal(
       }
       for (int i = 0; i < transitions().number_of_transitions(); ++i) {
         TransitionsAccessor(isolate_, transitions().GetTarget(i), no_gc)
-            .TraverseTransitionTreeInternal(callback, data, no_gc);
+            .TraverseTransitionTreeInternal(callback, no_gc);
       }
       break;
     }
   }
-  callback(map_, data);
+  callback(map_);
 }
 
 #ifdef DEBUG
diff --git a/chromium/v8/src/objects/transitions.h b/chromium/v8/src/objects/transitions.h
index 237cfcd0efa..473827fd405 100644
--- a/chromium/v8/src/objects/transitions.h
+++ b/chromium/v8/src/objects/transitions.h
@@ -100,13 +100,13 @@ class V8_EXPORT_PRIVATE TransitionsAccessor {
       PropertyAttributes* out_integrity_level = nullptr);
 
   // ===== ITERATION =====
-  using TraverseCallback = void (*)(Map map, void* data);
+  using TraverseCallback = std::function<void(Map)>;
 
   // Traverse the transition tree in postorder.
-  void TraverseTransitionTree(TraverseCallback callback, void* data) {
+  void TraverseTransitionTree(TraverseCallback callback) {
     // Make sure that we do not allocate in the callback.
     DisallowGarbageCollection no_gc;
-    TraverseTransitionTreeInternal(callback, data, &no_gc);
+    TraverseTransitionTreeInternal(callback, &no_gc);
   }
 
   // ===== PROTOTYPE TRANSITIONS =====
@@ -192,7 +192,7 @@ class V8_EXPORT_PRIVATE TransitionsAccessor {
   void SetPrototypeTransitions(Handle<WeakFixedArray> proto_transitions);
   WeakFixedArray GetPrototypeTransitions();
 
-  void TraverseTransitionTreeInternal(TraverseCallback callback, void* data,
+  void TraverseTransitionTreeInternal(TraverseCallback callback,
                                       DisallowGarbageCollection* no_gc);
 
   Isolate* isolate_;
diff --git a/chromium/v8/src/objects/value-serializer.cc b/chromium/v8/src/objects/value-serializer.cc
index 43d946943b0..9984f097a42 100644
--- a/chromium/v8/src/objects/value-serializer.cc
+++ b/chromium/v8/src/objects/value-serializer.cc
@@ -22,6 +22,7 @@
 #include "src/objects/js-array-inl.h"
 #include "src/objects/js-collection-inl.h"
 #include "src/objects/js-regexp-inl.h"
+#include "src/objects/map-updater.h"
 #include "src/objects/objects-inl.h"
 #include "src/objects/objects.h"
 #include "src/objects/oddball-inl.h"
@@ -226,6 +227,8 @@ enum class ErrorTag : uint8_t {
   kUriErrorPrototype = 'U',
   // Followed by message: string.
   kMessage = 'm',
+  // Followed by a JS object: cause.
+  kCause = 'c',
   // Followed by stack: string.
   kStack = 's',
   // The end of this error information.
@@ -299,6 +302,9 @@ void ValueSerializer::WriteZigZag(T value) {
               (value >> (8 * sizeof(T) - 1)));
 }
 
+template EXPORT_TEMPLATE_DEFINE(
+    V8_EXPORT_PRIVATE) void ValueSerializer::WriteZigZag(int32_t value);
+
 void ValueSerializer::WriteDouble(double value) {
   // Warning: this uses host endianness.
   WriteRawBytes(&value, sizeof(value));
@@ -934,6 +940,9 @@ Maybe<bool> ValueSerializer::WriteJSError(Handle<JSObject> error) {
   Maybe<bool> message_found = JSReceiver::GetOwnPropertyDescriptor(
       isolate_, error, isolate_->factory()->message_string(), &message_desc);
   MAYBE_RETURN(message_found, Nothing<bool>());
+  PropertyDescriptor cause_desc;
+  Maybe<bool> cause_found = JSReceiver::GetOwnPropertyDescriptor(
+      isolate_, error, isolate_->factory()->cause_string(), &cause_desc);
 
   WriteTag(SerializationTag::kError);
 
@@ -973,6 +982,15 @@ Maybe<bool> ValueSerializer::WriteJSError(Handle<JSObject> error) {
     WriteString(message);
   }
 
+  if (cause_found.FromJust() &&
+      PropertyDescriptor::IsDataDescriptor(&cause_desc)) {
+    Handle<Object> cause = cause_desc.value();
+    WriteVarint(static_cast<uint8_t>(ErrorTag::kCause));
+    if (!WriteObject(cause).FromMaybe(false)) {
+      return Nothing<bool>();
+    }
+  }
+
   if (!Object::GetProperty(isolate_, error, isolate_->factory()->stack_string())
            .ToHandle(&stack)) {
     return Nothing<bool>();
@@ -1200,6 +1218,9 @@ Maybe<T> ValueDeserializer::ReadZigZag() {
                              -static_cast<T>(unsigned_value & 1)));
 }
 
+template EXPORT_TEMPLATE_DEFINE(
+    V8_EXPORT_PRIVATE) Maybe<int32_t> ValueDeserializer::ReadZigZag();
+
 Maybe<double> ValueDeserializer::ReadDouble() {
   // Warning: this uses host endianness.
   if (sizeof(double) > static_cast<unsigned>(end_ - position_))
@@ -1527,7 +1548,7 @@ MaybeHandle<JSArray> ValueDeserializer::ReadSparseJSArray() {
   HandleScope scope(isolate_);
   Handle<JSArray> array =
       isolate_->factory()->NewJSArray(0, TERMINAL_FAST_ELEMENTS_KIND);
-  JSArray::SetLength(array, length);
+  MAYBE_RETURN(JSArray::SetLength(array, length), MaybeHandle<JSArray>());
   AddObjectWithID(id, array);
 
   uint32_t num_properties;
@@ -1874,6 +1895,7 @@ MaybeHandle<JSArrayBufferView> ValueDeserializer::ReadJSArrayBufferView(
 
 MaybeHandle<Object> ValueDeserializer::ReadJSError() {
   Handle<Object> message = isolate_->factory()->undefined_value();
+  Handle<Object> options = isolate_->factory()->undefined_value();
   Handle<Object> stack = isolate_->factory()->undefined_value();
   Handle<Object> no_caller;
   auto constructor = isolate_->error_function();
@@ -1911,6 +1933,20 @@ MaybeHandle<Object> ValueDeserializer::ReadJSError() {
         message = message_string;
         break;
       }
+      case ErrorTag::kCause: {
+        Handle<Object> cause;
+        if (!ReadObject().ToHandle(&cause)) {
+          return MaybeHandle<JSObject>();
+        }
+        options = isolate_->factory()->NewJSObject(isolate_->object_function());
+        if (JSObject::DefinePropertyOrElementIgnoreAttributes(
+                Handle<JSObject>::cast(options),
+                isolate_->factory()->cause_string(), cause, DONT_ENUM)
+                .is_null()) {
+          return MaybeHandle<JSObject>();
+        }
+        break;
+      }
       case ErrorTag::kStack: {
         Handle<String> stack_string;
         if (!ReadString().ToHandle(&stack_string)) {
@@ -1929,7 +1965,7 @@ MaybeHandle<Object> ValueDeserializer::ReadJSError() {
 
   Handle<Object> error;
   if (!ErrorUtils::Construct(isolate_, constructor, constructor, message,
-                             SKIP_NONE, no_caller,
+                             options, SKIP_NONE, no_caller,
                              ErrorUtils::StackTraceCollection::kNone)
            .ToHandle(&error)) {
     return MaybeHandle<Object>();
@@ -2101,9 +2137,9 @@ Maybe<uint32_t> ValueDeserializer::ReadJSObjectProperties(
                    .NowContains(value)) {
             Handle<FieldType> value_type =
                 value->OptimalType(isolate_, expected_representation);
-            Map::GeneralizeField(isolate_, target, descriptor,
-                                 details.constness(), expected_representation,
-                                 value_type);
+            MapUpdater::GeneralizeField(isolate_, target, descriptor,
+                                        details.constness(),
+                                        expected_representation, value_type);
           }
           DCHECK(target->instance_descriptors(isolate_)
                      .GetFieldType(descriptor)
@@ -2285,7 +2321,7 @@ ValueDeserializer::ReadObjectUsingEntireBufferForLegacyFormat() {
 
         Handle<JSArray> js_array =
             isolate_->factory()->NewJSArray(0, TERMINAL_FAST_ELEMENTS_KIND);
-        JSArray::SetLength(js_array, length);
+        MAYBE_RETURN_NULL(JSArray::SetLength(js_array, length));
         size_t begin_properties =
             stack.size() - 2 * static_cast<size_t>(num_properties);
         if (num_properties &&
diff --git a/chromium/v8/src/objects/visitors.h b/chromium/v8/src/objects/visitors.h
index 1111bf25129..947db3fa510 100644
--- a/chromium/v8/src/objects/visitors.h
+++ b/chromium/v8/src/objects/visitors.h
@@ -39,6 +39,8 @@ class CodeDataContainer;
   V(kReadOnlyObjectCache, "(Read-only object cache)") \
   V(kWeakCollections, "(Weak collections)")           \
   V(kWrapperTracing, "(Wrapper tracing)")             \
+  V(kWriteBarrier, "(Write barrier)")                 \
+  V(kRetainMaps, "(Retain maps)")                     \
   V(kUnknown, "(Unknown)")
 
 class VisitorSynchronization : public AllStatic {
@@ -162,6 +164,9 @@ class ObjectVisitor {
 
   // Visits the relocation info using the given iterator.
   virtual void VisitRelocInfo(RelocIterator* it);
+
+  // Visits the object's map pointer, decoding as necessary
+  virtual void VisitMapPointer(HeapObject host) { UNREACHABLE(); }
 };
 
 }  // namespace internal
diff --git a/chromium/v8/src/parsing/literal-buffer.cc b/chromium/v8/src/parsing/literal-buffer.cc
index 42a41cb15d6..a3e665a5c3c 100644
--- a/chromium/v8/src/parsing/literal-buffer.cc
+++ b/chromium/v8/src/parsing/literal-buffer.cc
@@ -12,8 +12,8 @@
 namespace v8 {
 namespace internal {
 
-template <typename LocalIsolate>
-Handle<String> LiteralBuffer::Internalize(LocalIsolate* isolate) const {
+template <typename IsolateT>
+Handle<String> LiteralBuffer::Internalize(IsolateT* isolate) const {
   if (is_one_byte()) {
     return isolate->factory()->InternalizeString(one_byte_literal());
   }
diff --git a/chromium/v8/src/parsing/literal-buffer.h b/chromium/v8/src/parsing/literal-buffer.h
index 60c70a5b468..3a3457082c0 100644
--- a/chromium/v8/src/parsing/literal-buffer.h
+++ b/chromium/v8/src/parsing/literal-buffer.h
@@ -66,8 +66,8 @@ class LiteralBuffer final {
     is_one_byte_ = true;
   }
 
-  template <typename LocalIsolate>
-  Handle<String> Internalize(LocalIsolate* isolate) const;
+  template <typename IsolateT>
+  Handle<String> Internalize(IsolateT* isolate) const;
 
  private:
   static const int kInitialCapacity = 16;
diff --git a/chromium/v8/src/parsing/parse-info.cc b/chromium/v8/src/parsing/parse-info.cc
index 69d18ef2b2b..6f469383a30 100644
--- a/chromium/v8/src/parsing/parse-info.cc
+++ b/chromium/v8/src/parsing/parse-info.cc
@@ -234,9 +234,9 @@ ParseInfo::~ParseInfo() = default;
 
 DeclarationScope* ParseInfo::scope() const { return literal()->scope(); }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 Handle<Script> ParseInfo::CreateScript(
-    LocalIsolate* isolate, Handle<String> source,
+    IsolateT* isolate, Handle<String> source,
     MaybeHandle<FixedArray> maybe_wrapped_arguments,
     ScriptOriginOptions origin_options, NativesFlag natives) {
   // Create a script object describing the script to be compiled.
diff --git a/chromium/v8/src/parsing/parse-info.h b/chromium/v8/src/parsing/parse-info.h
index 2068847efbc..d203ebed854 100644
--- a/chromium/v8/src/parsing/parse-info.h
+++ b/chromium/v8/src/parsing/parse-info.h
@@ -212,9 +212,9 @@ class V8_EXPORT_PRIVATE ParseInfo {
 
   ~ParseInfo();
 
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-  Handle<Script> CreateScript(LocalIsolate* isolate, Handle<String> source,
+  Handle<Script> CreateScript(IsolateT* isolate, Handle<String> source,
                               MaybeHandle<FixedArray> maybe_wrapped_arguments,
                               ScriptOriginOptions origin_options,
                               NativesFlag natives = NOT_NATIVES_CODE);
diff --git a/chromium/v8/src/parsing/parser-base.h b/chromium/v8/src/parsing/parser-base.h
index db0966803b1..d30c3f1b1fc 100644
--- a/chromium/v8/src/parsing/parser-base.h
+++ b/chromium/v8/src/parsing/parser-base.h
@@ -1060,14 +1060,14 @@ class ParserBase {
   bool is_resumable() const {
     return IsResumableFunction(function_state_->kind());
   }
-  bool is_class_static_block() const {
-    return function_state_->kind() ==
-           FunctionKind::kClassStaticInitializerFunction;
-  }
   bool is_await_allowed() const {
     return is_async_function() || (flags().allow_harmony_top_level_await() &&
                                    IsModule(function_state_->kind()));
   }
+  bool is_await_as_identifier_disallowed() {
+    return flags().is_module() ||
+           IsAwaitAsIdentifierDisallowed(function_state_->kind());
+  }
   const PendingCompilationErrorHandler* pending_error_handler() const {
     return pending_error_handler_;
   }
@@ -1652,8 +1652,7 @@ ParserBase<Impl>::ParseAndClassifyIdentifier(Token::Value next) {
   }
 
   if (!Token::IsValidIdentifier(next, language_mode(), is_generator(),
-                                flags().is_module() || is_async_function() ||
-                                    is_class_static_block())) {
+                                is_await_as_identifier_disallowed())) {
     ReportUnexpectedToken(next);
     return impl()->EmptyIdentifierString();
   }
@@ -1677,7 +1676,8 @@ typename ParserBase<Impl>::IdentifierT ParserBase<Impl>::ParseIdentifier(
 
   if (!Token::IsValidIdentifier(
           next, language_mode(), IsGeneratorFunction(function_kind),
-          flags().is_module() || IsAsyncFunction(function_kind))) {
+          flags().is_module() ||
+              IsAwaitAsIdentifierDisallowed(function_kind))) {
     ReportUnexpectedToken(next);
     return impl()->EmptyIdentifierString();
   }
@@ -2570,9 +2570,8 @@ ParserBase<Impl>::ParseObjectPropertyDefinition(ParsePropertyInfo* prop_info,
       //    IdentifierReference Initializer?
       DCHECK_EQ(function_flags, ParseFunctionFlag::kIsNormal);
 
-      if (!Token::IsValidIdentifier(
-              name_token, language_mode(), is_generator(),
-              flags().is_module() || is_async_function())) {
+      if (!Token::IsValidIdentifier(name_token, language_mode(), is_generator(),
+                                    is_await_as_identifier_disallowed())) {
         ReportUnexpectedToken(Next());
         return impl()->NullLiteralProperty();
       }
@@ -4427,6 +4426,12 @@ bool ParserBase<Impl>::IsNextLetKeyword() {
     case Token::ASYNC:
       return true;
     case Token::FUTURE_STRICT_RESERVED_WORD:
+    case Token::ESCAPED_STRICT_RESERVED_WORD:
+      // The early error rule for future reserved keywords
+      // (ES#sec-identifiers-static-semantics-early-errors) uses the static
+      // semantics StringValue of IdentifierName, which normalizes escape
+      // sequences. So, both escaped and unescaped future reserved keywords are
+      // allowed as identifiers in sloppy mode.
       return is_sloppy(language_mode());
     default:
       return false;
@@ -4437,12 +4442,11 @@ template <typename Impl>
 typename ParserBase<Impl>::ExpressionT
 ParserBase<Impl>::ParseArrowFunctionLiteral(
     const FormalParametersT& formal_parameters) {
-  const RuntimeCallCounterId counters[2] = {
-      RuntimeCallCounterId::kParseArrowFunctionLiteral,
-      RuntimeCallCounterId::kPreParseArrowFunctionLiteral};
-  RuntimeCallTimerScope runtime_timer(runtime_call_stats_,
-                                      counters[Impl::IsPreParser()],
-                                      RuntimeCallStats::kThreadSpecific);
+  RCS_SCOPE(runtime_call_stats_,
+            Impl::IsPreParser()
+                ? RuntimeCallCounterId::kPreParseArrowFunctionLiteral
+                : RuntimeCallCounterId::kParseArrowFunctionLiteral,
+            RuntimeCallStats::kThreadSpecific);
   base::ElapsedTimer timer;
   if (V8_UNLIKELY(FLAG_log_function_events)) timer.Start();
 
@@ -4631,7 +4635,7 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseClassLiteral(
   ClassInfo class_info(this);
   class_info.is_anonymous = is_anonymous;
 
-  scope()->set_start_position(end_position());
+  scope()->set_start_position(class_token_pos);
   if (Check(Token::EXTENDS)) {
     ClassScope::HeritageParsingScope heritage(class_scope);
     FuncNameInferrerState fni_state(&fni_);
@@ -5553,6 +5557,14 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseReturnStatement() {
     case MODULE_SCOPE:
       impl()->ReportMessageAt(loc, MessageTemplate::kIllegalReturn);
       return impl()->NullStatement();
+    case BLOCK_SCOPE:
+      // Class static blocks disallow return. They are their own var scopes and
+      // have a varblock scope.
+      if (function_state_->kind() == kClassStaticInitializerFunction) {
+        impl()->ReportMessageAt(loc, MessageTemplate::kIllegalReturn);
+        return impl()->NullStatement();
+      }
+      break;
     default:
       break;
   }
@@ -5987,7 +5999,8 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseForStatement(
       expression = ParseExpressionCoverGrammar();
       // `for (async of` is disallowed but `for (async.x of` is allowed, so
       // check if the token is ASYNC after parsing the expression.
-      bool expression_is_async = scanner()->current_token() == Token::ASYNC;
+      bool expression_is_async = scanner()->current_token() == Token::ASYNC &&
+                                 !scanner()->literal_contains_escapes();
       // Initializer is reference followed by in/of.
       lhs_end_pos = end_position();
       is_for_each = CheckInOrOf(&for_info.mode);
diff --git a/chromium/v8/src/parsing/parser.cc b/chromium/v8/src/parsing/parser.cc
index 92e11f6b9cc..0671fc5f6b8 100644
--- a/chromium/v8/src/parsing/parser.cc
+++ b/chromium/v8/src/parsing/parser.cc
@@ -522,10 +522,9 @@ void Parser::ParseProgram(Isolate* isolate, Handle<Script> script,
   // It's OK to use the Isolate & counters here, since this function is only
   // called in the main thread.
   DCHECK(parsing_on_main_thread_);
-  RuntimeCallTimerScope runtime_timer(
-      runtime_call_stats_, flags().is_eval()
-                               ? RuntimeCallCounterId::kParseEval
-                               : RuntimeCallCounterId::kParseProgram);
+  RCS_SCOPE(runtime_call_stats_, flags().is_eval()
+                                     ? RuntimeCallCounterId::kParseEval
+                                     : RuntimeCallCounterId::kParseProgram);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.ParseProgram");
   base::ElapsedTimer timer;
   if (V8_UNLIKELY(FLAG_log_function_events)) timer.Start();
@@ -704,9 +703,8 @@ void Parser::PostProcessParseResult(Isolate* isolate, ParseInfo* info,
   if (isolate) info->ast_value_factory()->Internalize(isolate);
 
   {
-    RuntimeCallTimerScope runtimeTimer(info->runtime_call_stats(),
-                                       RuntimeCallCounterId::kCompileAnalyse,
-                                       RuntimeCallStats::kThreadSpecific);
+    RCS_SCOPE(info->runtime_call_stats(), RuntimeCallCounterId::kCompileAnalyse,
+              RuntimeCallStats::kThreadSpecific);
     if (!Rewriter::Rewrite(info) || !DeclarationScope::Analyze(info)) {
       // Null out the literal to indicate that something failed.
       info->set_literal(nullptr);
@@ -819,8 +817,7 @@ void Parser::ParseFunction(Isolate* isolate, ParseInfo* info,
   // It's OK to use the Isolate & counters here, since this function is only
   // called in the main thread.
   DCHECK(parsing_on_main_thread_);
-  RuntimeCallTimerScope runtime_timer(runtime_call_stats_,
-                                      RuntimeCallCounterId::kParseFunction);
+  RCS_SCOPE(runtime_call_stats_, RuntimeCallCounterId::kParseFunction);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.ParseFunction");
   base::ElapsedTimer timer;
   if (V8_UNLIKELY(FLAG_log_function_events)) timer.Start();
@@ -833,14 +830,23 @@ void Parser::ParseFunction(Isolate* isolate, ParseInfo* info,
                         Scope::DeserializationMode::kIncludingVariables);
   DCHECK_EQ(factory()->zone(), info->zone());
 
+  Handle<Script> script = handle(Script::cast(shared_info->script()), isolate);
   if (shared_info->is_wrapped()) {
-    maybe_wrapped_arguments_ = handle(
-        Script::cast(shared_info->script()).wrapped_arguments(), isolate);
+    maybe_wrapped_arguments_ = handle(script->wrapped_arguments(), isolate);
   }
 
   int start_position = shared_info->StartPosition();
   int end_position = shared_info->EndPosition();
   int function_literal_id = shared_info->function_literal_id();
+  if V8_UNLIKELY (script->type() == Script::TYPE_WEB_SNAPSHOT) {
+    // Function literal IDs for inner functions haven't been allocated when
+    // deserializing. Put the inner function SFIs to the end of the list;
+    // they'll be deduplicated later (if the corresponding SFIs exist already)
+    // in Script::FindSharedFunctionInfo. (-1 here because function_literal_id
+    // is the parent's id. The inner function will get ids starting from
+    // function_literal_id + 1.)
+    function_literal_id = script->shared_function_info_count() - 1;
+  }
 
   // Initialize parser state.
   Handle<String> name(shared_info->Name(), isolate);
@@ -865,9 +871,10 @@ void Parser::ParseFunction(Isolate* isolate, ParseInfo* info,
   if (result != nullptr) {
     Handle<String> inferred_name(shared_info->inferred_name(), isolate);
     result->set_inferred_name(inferred_name);
+    // Fix the function_literal_id in case we changed it earlier.
+    result->set_function_literal_id(shared_info->function_literal_id());
   }
   PostProcessParseResult(isolate, info, result);
-
   if (V8_UNLIKELY(FLAG_log_function_events) && result != nullptr) {
     double ms = timer.Elapsed().InMillisecondsF();
     // We should already be internalized by now, so the debug name will be
@@ -971,6 +978,10 @@ FunctionLiteral* Parser::DoParseFunction(Isolate* isolate, ParseInfo* info,
           if (p->initializer() != nullptr) {
             reindexer.Reindex(p->initializer());
           }
+          if (reindexer.HasStackOverflow()) {
+            set_stack_overflow();
+            return nullptr;
+          }
         }
         ResetFunctionLiteralId();
         SkipFunctionLiterals(function_literal_id - 1);
@@ -2559,9 +2570,8 @@ FunctionLiteral* Parser::ParseFunctionLiteral(
   const bool is_lazy_top_level_function = is_lazy && is_top_level;
   const bool is_lazy_inner_function = is_lazy && !is_top_level;
 
-  RuntimeCallTimerScope runtime_timer(
-      runtime_call_stats_, RuntimeCallCounterId::kParseFunctionLiteral,
-      RuntimeCallStats::kThreadSpecific);
+  RCS_SCOPE(runtime_call_stats_, RuntimeCallCounterId::kParseFunctionLiteral,
+            RuntimeCallStats::kThreadSpecific);
   base::ElapsedTimer timer;
   if (V8_UNLIKELY(FLAG_log_function_events)) timer.Start();
 
@@ -2652,14 +2662,14 @@ FunctionLiteral* Parser::ParseFunctionLiteral(
         reinterpret_cast<const char*>(function_name->raw_data()),
         function_name->byte_length(), function_name->is_one_byte());
   }
-  if (V8_UNLIKELY(TracingFlags::is_runtime_stats_enabled()) &&
-      did_preparse_successfully) {
-    if (runtime_call_stats_) {
-      runtime_call_stats_->CorrectCurrentCounterId(
-          RuntimeCallCounterId::kPreParseWithVariableResolution,
-          RuntimeCallStats::kThreadSpecific);
-    }
+#ifdef V8_RUNTIME_CALL_STATS
+  if (did_preparse_successfully && runtime_call_stats_ &&
+      V8_UNLIKELY(TracingFlags::is_runtime_stats_enabled())) {
+    runtime_call_stats_->CorrectCurrentCounterId(
+        RuntimeCallCounterId::kPreParseWithVariableResolution,
+        RuntimeCallStats::kThreadSpecific);
   }
+#endif  // V8_RUNTIME_CALL_STATS
 
   // Validate function name. We can do this only after parsing the function,
   // since the function can declare itself strict.
@@ -3224,9 +3234,8 @@ void Parser::InsertSloppyBlockFunctionVarBindings(DeclarationScope* scope) {
 // ----------------------------------------------------------------------------
 // Parser support
 
-template <typename LocalIsolate>
-void Parser::HandleSourceURLComments(LocalIsolate* isolate,
-                                     Handle<Script> script) {
+template <typename IsolateT>
+void Parser::HandleSourceURLComments(IsolateT* isolate, Handle<Script> script) {
   Handle<String> source_url = scanner_.SourceUrl(isolate);
   if (!source_url.is_null()) {
     script->set_source_url(*source_url);
@@ -3264,8 +3273,7 @@ void Parser::UpdateStatistics(Isolate* isolate, Handle<Script> script) {
 
 void Parser::ParseOnBackground(ParseInfo* info, int start_position,
                                int end_position, int function_literal_id) {
-  RuntimeCallTimerScope runtimeTimer(
-      runtime_call_stats_, RuntimeCallCounterId::kParseBackgroundProgram);
+  RCS_SCOPE(runtime_call_stats_, RuntimeCallCounterId::kParseBackgroundProgram);
   parsing_on_main_thread_ = false;
 
   DCHECK_NULL(info->literal());
diff --git a/chromium/v8/src/parsing/parser.h b/chromium/v8/src/parsing/parser.h
index 4ede3035036..07efef277e1 100644
--- a/chromium/v8/src/parsing/parser.h
+++ b/chromium/v8/src/parsing/parser.h
@@ -161,8 +161,8 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
 
   // Move statistics to Isolate
   void UpdateStatistics(Isolate* isolate, Handle<Script> script);
-  template <typename LocalIsolate>
-  void HandleSourceURLComments(LocalIsolate* isolate, Handle<Script> script);
+  template <typename IsolateT>
+  void HandleSourceURLComments(IsolateT* isolate, Handle<Script> script);
 
  private:
   friend class ParserBase<Parser>;
@@ -654,15 +654,6 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
     }
   }
 
-  // A shortcut for performing a ToString operation
-  V8_INLINE Expression* ToString(Expression* expr) {
-    if (expr->IsStringLiteral()) return expr;
-    ScopedPtrList<Expression> args(pointer_buffer());
-    args.Add(expr);
-    return factory()->NewCallRuntime(Runtime::kInlineToString, args,
-                                     expr->position());
-  }
-
   // Returns true if we have a binary expression between two numeric
   // literals. In that case, *x will be changed to an expression which is the
   // computed value.
diff --git a/chromium/v8/src/parsing/pending-compilation-error-handler.cc b/chromium/v8/src/parsing/pending-compilation-error-handler.cc
index dccd6dba77e..2ab5b3eb1ad 100644
--- a/chromium/v8/src/parsing/pending-compilation-error-handler.cc
+++ b/chromium/v8/src/parsing/pending-compilation-error-handler.cc
@@ -31,9 +31,9 @@ void PendingCompilationErrorHandler::MessageDetails::SetString(
   arg_handle_ = isolate->heap()->NewPersistentHandle(string);
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 void PendingCompilationErrorHandler::MessageDetails::Prepare(
-    LocalIsolate* isolate) {
+    IsolateT* isolate) {
   switch (type_) {
     case kAstRawString:
       return SetString(arg_->string(), isolate);
@@ -101,8 +101,8 @@ void PendingCompilationErrorHandler::ReportWarningAt(int start_position,
       MessageDetails(start_position, end_position, message, arg));
 }
 
-template <typename LocalIsolate>
-void PendingCompilationErrorHandler::PrepareWarnings(LocalIsolate* isolate) {
+template <typename IsolateT>
+void PendingCompilationErrorHandler::PrepareWarnings(IsolateT* isolate) {
   DCHECK(!has_pending_error());
 
   for (MessageDetails& warning : warning_messages_) {
@@ -128,9 +128,9 @@ void PendingCompilationErrorHandler::ReportWarnings(
   }
 }
 
-template <typename LocalIsolate>
+template <typename IsolateT>
 void PendingCompilationErrorHandler::PrepareErrors(
-    LocalIsolate* isolate, AstValueFactory* ast_value_factory) {
+    IsolateT* isolate, AstValueFactory* ast_value_factory) {
   if (stack_overflow()) return;
 
   DCHECK(has_pending_error());
diff --git a/chromium/v8/src/parsing/pending-compilation-error-handler.h b/chromium/v8/src/parsing/pending-compilation-error-handler.h
index 5efb5a43a48..31e765d5145 100644
--- a/chromium/v8/src/parsing/pending-compilation-error-handler.h
+++ b/chromium/v8/src/parsing/pending-compilation-error-handler.h
@@ -53,15 +53,15 @@ class PendingCompilationErrorHandler {
   bool has_pending_warnings() const { return !warning_messages_.empty(); }
 
   // Handle errors detected during parsing.
-  template <typename LocalIsolate>
+  template <typename IsolateT>
   EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-  void PrepareErrors(LocalIsolate* isolate, AstValueFactory* ast_value_factory);
+  void PrepareErrors(IsolateT* isolate, AstValueFactory* ast_value_factory);
   V8_EXPORT_PRIVATE void ReportErrors(Isolate* isolate,
                                       Handle<Script> script) const;
 
   // Handle warnings detected during compilation.
-  template <typename LocalIsolate>
-  void PrepareWarnings(LocalIsolate* isolate);
+  template <typename IsolateT>
+  void PrepareWarnings(IsolateT* isolate);
   void ReportWarnings(Isolate* isolate, Handle<Script> script) const;
 
   V8_EXPORT_PRIVATE Handle<String> FormatErrorMessageForTest(Isolate* isolate);
@@ -106,8 +106,8 @@ class PendingCompilationErrorHandler {
     MessageLocation GetLocation(Handle<Script> script) const;
     MessageTemplate message() const { return message_; }
 
-    template <typename LocalIsolate>
-    void Prepare(LocalIsolate* isolate);
+    template <typename IsolateT>
+    void Prepare(IsolateT* isolate);
 
    private:
     enum Type { kNone, kAstRawString, kConstCharString, kMainThreadHandle };
diff --git a/chromium/v8/src/parsing/preparser.cc b/chromium/v8/src/parsing/preparser.cc
index 2764e00a8bf..4547e602ee3 100644
--- a/chromium/v8/src/parsing/preparser.cc
+++ b/chromium/v8/src/parsing/preparser.cc
@@ -272,10 +272,9 @@ PreParser::Expression PreParser::ParseFunctionLiteral(
   DCHECK_NE(FunctionSyntaxKind::kWrapped, function_syntax_kind);
   // Function ::
   //   '(' FormalParameterList? ')' '{' FunctionBody '}'
-  RuntimeCallTimerScope runtime_timer(
-      runtime_call_stats_,
-      RuntimeCallCounterId::kPreParseWithVariableResolution,
-      RuntimeCallStats::kThreadSpecific);
+  RCS_SCOPE(runtime_call_stats_,
+            RuntimeCallCounterId::kPreParseWithVariableResolution,
+            RuntimeCallStats::kThreadSpecific);
 
   base::ElapsedTimer timer;
   if (V8_UNLIKELY(FLAG_log_function_events)) timer.Start();
diff --git a/chromium/v8/src/parsing/rewriter.cc b/chromium/v8/src/parsing/rewriter.cc
index dee07632803..35f82e25ab4 100644
--- a/chromium/v8/src/parsing/rewriter.cc
+++ b/chromium/v8/src/parsing/rewriter.cc
@@ -382,10 +382,9 @@ DECLARATION_NODE_LIST(DEF_VISIT)
 // Assumes code has been parsed.  Mutates the AST, so the AST should not
 // continue to be used in the case of failure.
 bool Rewriter::Rewrite(ParseInfo* info) {
-  RuntimeCallTimerScope runtimeTimer(
-      info->runtime_call_stats(),
-      RuntimeCallCounterId::kCompileRewriteReturnResult,
-      RuntimeCallStats::kThreadSpecific);
+  RCS_SCOPE(info->runtime_call_stats(),
+            RuntimeCallCounterId::kCompileRewriteReturnResult,
+            RuntimeCallStats::kThreadSpecific);
 
   FunctionLiteral* function = info->literal();
   DCHECK_NOT_NULL(function);
diff --git a/chromium/v8/src/parsing/scanner-character-streams.cc b/chromium/v8/src/parsing/scanner-character-streams.cc
index 434b83676c0..a5fec69e84c 100644
--- a/chromium/v8/src/parsing/scanner-character-streams.cc
+++ b/chromium/v8/src/parsing/scanner-character-streams.cc
@@ -215,8 +215,7 @@ class ChunkedStream {
     const uint8_t* data = nullptr;
     size_t length;
     {
-      RuntimeCallTimerScope scope(stats,
-                                  RuntimeCallCounterId::kGetMoreDataCallback);
+      RCS_SCOPE(stats, RuntimeCallCounterId::kGetMoreDataCallback);
       length = source_->GetMoreData(&data);
     }
     ProcessChunk(data, position, length);
@@ -721,8 +720,7 @@ void Utf8ExternalStreamingStream::FillBufferFromCurrentChunk() {
 }
 
 bool Utf8ExternalStreamingStream::FetchChunk() {
-  RuntimeCallTimerScope scope(runtime_call_stats(),
-                              RuntimeCallCounterId::kGetMoreDataCallback);
+  RCS_SCOPE(runtime_call_stats(), RuntimeCallCounterId::kGetMoreDataCallback);
   DCHECK_EQ(current_.chunk_no, chunks_.size());
   DCHECK(chunks_.empty() || chunks_.back().length != 0);
 
diff --git a/chromium/v8/src/parsing/scanner.cc b/chromium/v8/src/parsing/scanner.cc
index c5960787629..8ee64a16966 100644
--- a/chromium/v8/src/parsing/scanner.cc
+++ b/chromium/v8/src/parsing/scanner.cc
@@ -586,8 +586,8 @@ Token::Value Scanner::ScanTemplateSpan() {
   return result;
 }
 
-template <typename LocalIsolate>
-Handle<String> Scanner::SourceUrl(LocalIsolate* isolate) const {
+template <typename IsolateT>
+Handle<String> Scanner::SourceUrl(IsolateT* isolate) const {
   Handle<String> tmp;
   if (source_url_.length() > 0) {
     tmp = source_url_.Internalize(isolate);
@@ -598,8 +598,8 @@ Handle<String> Scanner::SourceUrl(LocalIsolate* isolate) const {
 template Handle<String> Scanner::SourceUrl(Isolate* isolate) const;
 template Handle<String> Scanner::SourceUrl(LocalIsolate* isolate) const;
 
-template <typename LocalIsolate>
-Handle<String> Scanner::SourceMappingUrl(LocalIsolate* isolate) const {
+template <typename IsolateT>
+Handle<String> Scanner::SourceMappingUrl(IsolateT* isolate) const {
   Handle<String> tmp;
   if (source_mapping_url_.length() > 0) {
     tmp = source_mapping_url_.Internalize(isolate);
diff --git a/chromium/v8/src/parsing/scanner.h b/chromium/v8/src/parsing/scanner.h
index 3df234ce54a..d93f581366f 100644
--- a/chromium/v8/src/parsing/scanner.h
+++ b/chromium/v8/src/parsing/scanner.h
@@ -407,10 +407,10 @@ class V8_EXPORT_PRIVATE Scanner {
     return ScanTemplateSpan();
   }
 
-  template <typename LocalIsolate>
-  Handle<String> SourceUrl(LocalIsolate* isolate) const;
-  template <typename LocalIsolate>
-  Handle<String> SourceMappingUrl(LocalIsolate* isolate) const;
+  template <typename IsolateT>
+  Handle<String> SourceUrl(IsolateT* isolate) const;
+  template <typename IsolateT>
+  Handle<String> SourceMappingUrl(IsolateT* isolate) const;
 
   bool FoundHtmlComment() const { return found_html_comment_; }
 
diff --git a/chromium/v8/src/profiler/cpu-profiler.cc b/chromium/v8/src/profiler/cpu-profiler.cc
index eba513b39d5..ba9022be1b0 100644
--- a/chromium/v8/src/profiler/cpu-profiler.cc
+++ b/chromium/v8/src/profiler/cpu-profiler.cc
@@ -104,10 +104,11 @@ ProfilingScope::~ProfilingScope() {
 
 ProfilerEventsProcessor::ProfilerEventsProcessor(
     Isolate* isolate, Symbolizer* symbolizer,
-    ProfilerCodeObserver* code_observer)
+    ProfilerCodeObserver* code_observer, CpuProfilesCollection* profiles)
     : Thread(Thread::Options("v8:ProfEvntProc", kProfilerStackSize)),
       symbolizer_(symbolizer),
       code_observer_(code_observer),
+      profiles_(profiles),
       last_code_event_id_(0),
       last_processed_code_event_id_(0),
       isolate_(isolate) {
@@ -119,9 +120,8 @@ SamplingEventsProcessor::SamplingEventsProcessor(
     Isolate* isolate, Symbolizer* symbolizer,
     ProfilerCodeObserver* code_observer, CpuProfilesCollection* profiles,
     base::TimeDelta period, bool use_precise_sampling)
-    : ProfilerEventsProcessor(isolate, symbolizer, code_observer),
+    : ProfilerEventsProcessor(isolate, symbolizer, code_observer, profiles),
       sampler_(new CpuSampler(isolate, this)),
-      profiles_(profiles),
       period_(period),
       use_precise_sampling_(use_precise_sampling) {
   sampler_->Start();
@@ -188,7 +188,14 @@ void ProfilerEventsProcessor::StopSynchronously() {
 bool ProfilerEventsProcessor::ProcessCodeEvent() {
   CodeEventsContainer record;
   if (events_buffer_.Dequeue(&record)) {
-    code_observer_->CodeEventHandlerInternal(record);
+    if (record.generic.type == CodeEventRecord::NATIVE_CONTEXT_MOVE) {
+      NativeContextMoveEventRecord& nc_record =
+          record.NativeContextMoveEventRecord_;
+      profiles_->UpdateNativeContextAddressForCurrentProfiles(
+          nc_record.from_address, nc_record.to_address);
+    } else {
+      code_observer_->CodeEventHandlerInternal(record);
+    }
     last_processed_code_event_id_ = record.generic.order;
     return true;
   }
@@ -202,6 +209,7 @@ void ProfilerEventsProcessor::CodeEventHandler(
     case CodeEventRecord::CODE_MOVE:
     case CodeEventRecord::CODE_DISABLE_OPT:
     case CodeEventRecord::CODE_DELETE:
+    case CodeEventRecord::NATIVE_CONTEXT_MOVE:
       Enqueue(evt_rec);
       break;
     case CodeEventRecord::CODE_DEOPT: {
@@ -224,7 +232,8 @@ void SamplingEventsProcessor::SymbolizeAndAddToProfiles(
       symbolizer_->SymbolizeTickSample(record->sample);
   profiles_->AddPathToCurrentProfiles(
       record->sample.timestamp, symbolized.stack_trace, symbolized.src_line,
-      record->sample.update_stats, record->sample.sampling_interval);
+      record->sample.update_stats, record->sample.sampling_interval,
+      reinterpret_cast<Address>(record->sample.context));
 }
 
 ProfilerEventsProcessor::SampleProcessingResult
@@ -371,6 +380,7 @@ void ProfilerCodeObserver::CodeEventHandlerInternal(
 }
 
 void ProfilerCodeObserver::CreateEntriesForRuntimeCallStats() {
+#ifdef V8_RUNTIME_CALL_STATS
   RuntimeCallStats* rcs = isolate_->counters()->runtime_call_stats();
   for (int i = 0; i < RuntimeCallStats::kNumberOfCounters; ++i) {
     RuntimeCallCounter* counter = rcs->GetCounter(i);
@@ -379,6 +389,7 @@ void ProfilerCodeObserver::CreateEntriesForRuntimeCallStats() {
                                "native V8Runtime");
     code_map_.AddCode(reinterpret_cast<Address>(counter), entry, 1);
   }
+#endif  // V8_RUNTIME_CALL_STATS
 }
 
 void ProfilerCodeObserver::LogBuiltins() {
diff --git a/chromium/v8/src/profiler/cpu-profiler.h b/chromium/v8/src/profiler/cpu-profiler.h
index d605a8c3d3d..ced37e4ade5 100644
--- a/chromium/v8/src/profiler/cpu-profiler.h
+++ b/chromium/v8/src/profiler/cpu-profiler.h
@@ -37,10 +37,14 @@ class Symbolizer;
   V(REPORT_BUILTIN, ReportBuiltinEventRecord)    \
   V(CODE_DELETE, CodeDeleteEventRecord)
 
+#define VM_EVENTS_TYPE_LIST(V) \
+  CODE_EVENTS_TYPE_LIST(V)     \
+  V(NATIVE_CONTEXT_MOVE, NativeContextMoveEventRecord)
+
 class CodeEventRecord {
  public:
 #define DECLARE_TYPE(type, ignore) type,
-  enum Type { NONE = 0, CODE_EVENTS_TYPE_LIST(DECLARE_TYPE) };
+  enum Type { NONE = 0, VM_EVENTS_TYPE_LIST(DECLARE_TYPE) };
 #undef DECLARE_TYPE
 
   Type type;
@@ -99,6 +103,13 @@ class ReportBuiltinEventRecord : public CodeEventRecord {
   V8_INLINE void UpdateCodeMap(CodeMap* code_map);
 };
 
+// Signals that a native context's address has changed.
+class NativeContextMoveEventRecord : public CodeEventRecord {
+ public:
+  Address from_address;
+  Address to_address;
+};
+
 // A record type for sending samples from the main thread/signal handler to the
 // profiling thread.
 class TickSampleEventRecord {
@@ -130,7 +141,7 @@ class CodeEventsContainer {
   union  {
     CodeEventRecord generic;
 #define DECLARE_CLASS(ignore, type) type type##_;
-    CODE_EVENTS_TYPE_LIST(DECLARE_CLASS)
+    VM_EVENTS_TYPE_LIST(DECLARE_CLASS)
 #undef DECLARE_CLASS
   };
 };
@@ -174,7 +185,8 @@ class V8_EXPORT_PRIVATE ProfilerEventsProcessor : public base::Thread,
 
  protected:
   ProfilerEventsProcessor(Isolate* isolate, Symbolizer* symbolizer,
-                          ProfilerCodeObserver* code_observer);
+                          ProfilerCodeObserver* code_observer,
+                          CpuProfilesCollection* profiles);
 
   // Called from events processing thread (Run() method.)
   bool ProcessCodeEvent();
@@ -188,6 +200,7 @@ class V8_EXPORT_PRIVATE ProfilerEventsProcessor : public base::Thread,
 
   Symbolizer* symbolizer_;
   ProfilerCodeObserver* code_observer_;
+  CpuProfilesCollection* profiles_;
   std::atomic_bool running_{true};
   base::ConditionVariable running_cond_;
   base::Mutex running_mutex_;
@@ -238,7 +251,6 @@ class V8_EXPORT_PRIVATE SamplingEventsProcessor
   SamplingCircularQueue<TickSampleEventRecord,
                         kTickSampleQueueLength> ticks_buffer_;
   std::unique_ptr<sampler::Sampler> sampler_;
-  CpuProfilesCollection* profiles_;
   base::TimeDelta period_;           // Samples & code events processing period.
   const bool use_precise_sampling_;  // Whether or not busy-waiting is used for
                                      // low sampling intervals on Windows.
diff --git a/chromium/v8/src/profiler/heap-profiler.cc b/chromium/v8/src/profiler/heap-profiler.cc
index 8a7ed34d46e..dbe48876d2e 100644
--- a/chromium/v8/src/profiler/heap-profiler.cc
+++ b/chromium/v8/src/profiler/heap-profiler.cc
@@ -81,9 +81,10 @@ v8::EmbedderGraph::Node::Detachedness HeapProfiler::GetDetachedness(
 HeapSnapshot* HeapProfiler::TakeSnapshot(
     v8::ActivityControl* control,
     v8::HeapProfiler::ObjectNameResolver* resolver,
-    bool treat_global_objects_as_roots) {
+    bool treat_global_objects_as_roots, bool capture_numeric_value) {
   is_taking_snapshot_ = true;
-  HeapSnapshot* result = new HeapSnapshot(this, treat_global_objects_as_roots);
+  HeapSnapshot* result = new HeapSnapshot(this, treat_global_objects_as_roots,
+                                          capture_numeric_value);
   {
     HeapSnapshotGenerator generator(result, control, resolver, heap());
     if (!generator.GenerateSnapshot()) {
diff --git a/chromium/v8/src/profiler/heap-profiler.h b/chromium/v8/src/profiler/heap-profiler.h
index ebf737523cc..fc867e66324 100644
--- a/chromium/v8/src/profiler/heap-profiler.h
+++ b/chromium/v8/src/profiler/heap-profiler.h
@@ -33,7 +33,8 @@ class HeapProfiler : public HeapObjectAllocationTracker {
 
   HeapSnapshot* TakeSnapshot(v8::ActivityControl* control,
                              v8::HeapProfiler::ObjectNameResolver* resolver,
-                             bool treat_global_objects_as_roots);
+                             bool treat_global_objects_as_roots,
+                             bool capture_numeric_value);
 
   bool StartSamplingHeapProfiler(uint64_t sample_interval, int stack_depth,
                                  v8::HeapProfiler::SamplingFlags);
diff --git a/chromium/v8/src/profiler/heap-snapshot-generator.cc b/chromium/v8/src/profiler/heap-snapshot-generator.cc
index 9cc26fa3e20..da4e57fad9a 100644
--- a/chromium/v8/src/profiler/heap-snapshot-generator.cc
+++ b/chromium/v8/src/profiler/heap-snapshot-generator.cc
@@ -183,9 +183,11 @@ const char* HeapEntry::TypeAsString() const {
   }
 }
 
-HeapSnapshot::HeapSnapshot(HeapProfiler* profiler, bool global_objects_as_roots)
+HeapSnapshot::HeapSnapshot(HeapProfiler* profiler, bool global_objects_as_roots,
+                           bool capture_numeric_value)
     : profiler_(profiler),
-      treat_global_objects_as_roots_(global_objects_as_roots) {
+      treat_global_objects_as_roots_(global_objects_as_roots),
+      capture_numeric_value_(capture_numeric_value) {
   // It is very important to keep objects that form a heap snapshot
   // as small as possible. Check assumptions about data structure sizes.
   STATIC_ASSERT(kSystemPointerSize != 4 || sizeof(HeapGraphEdge) == 12);
@@ -387,8 +389,7 @@ SnapshotObjectId HeapObjectsMap::FindOrAddEntry(Address addr,
     return entry_info.id;
   }
   entry->value = reinterpret_cast<void*>(entries_.size());
-  SnapshotObjectId id = next_id_;
-  next_id_ += kObjectIdStep;
+  SnapshotObjectId id = get_next_id();
   entries_.push_back(EntryInfo(id, addr, size, accessed));
   DCHECK(static_cast<uint32_t>(entries_.size()) > entries_map_.occupancy());
   return id;
@@ -553,6 +554,16 @@ HeapEntry* V8HeapExplorer::AllocateEntry(HeapThing ptr) {
   return AddEntry(HeapObject::cast(Object(reinterpret_cast<Address>(ptr))));
 }
 
+HeapEntry* V8HeapExplorer::AllocateEntry(Smi smi) {
+  SnapshotObjectId id = heap_object_map_->get_next_id();
+  HeapEntry* entry =
+      snapshot_->AddEntry(HeapEntry::kHeapNumber, "smi number", id, 0, 0);
+  // XXX: Smis do not appear in CombinedHeapObjectIterator, so we need to
+  // extract the references here
+  ExtractNumberReference(entry, smi);
+  return entry;
+}
+
 void V8HeapExplorer::ExtractLocation(HeapEntry* entry, HeapObject object) {
   if (object.IsJSFunction()) {
     JSFunction func = JSFunction::cast(object);
@@ -638,7 +649,7 @@ HeapEntry* V8HeapExplorer::AddEntry(HeapObject object) {
              object.IsByteArray()) {
     return AddEntry(object, HeapEntry::kArray, "");
   } else if (object.IsHeapNumber()) {
-    return AddEntry(object, HeapEntry::kHeapNumber, "number");
+    return AddEntry(object, HeapEntry::kHeapNumber, "heap number");
   }
   return AddEntry(object, HeapEntry::kHidden, GetSystemEntryName(object));
 }
@@ -721,6 +732,13 @@ class IndexedReferencesExtractor : public ObjectVisitor {
                      ObjectSlot end) override {
     VisitPointers(host, MaybeObjectSlot(start), MaybeObjectSlot(end));
   }
+  void VisitMapPointer(HeapObject object) override {
+    if (generator_->visited_fields_[0]) {
+      generator_->visited_fields_[0] = false;
+    } else {
+      VisitHeapObjectImpl(object.map(), 0);
+    }
+  }
   void VisitPointers(HeapObject host, MaybeObjectSlot start,
                      MaybeObjectSlot end) override {
     // [start,end) must be a sub-region of [parent_start_, parent_end), i.e.
@@ -830,6 +848,10 @@ void V8HeapExplorer::ExtractReferences(HeapEntry* entry, HeapObject obj) {
     ExtractEphemeronHashTableReferences(entry, EphemeronHashTable::cast(obj));
   } else if (obj.IsFixedArray()) {
     ExtractFixedArrayReferences(entry, FixedArray::cast(obj));
+  } else if (obj.IsHeapNumber()) {
+    if (snapshot_->capture_numeric_value()) {
+      ExtractNumberReference(entry, obj);
+    }
   }
 }
 
@@ -867,7 +889,7 @@ void V8HeapExplorer::ExtractJSObjectReferences(HeapEntry* entry,
   } else if (obj.IsJSFunction()) {
     JSFunction js_fun = JSFunction::cast(js_obj);
     if (js_fun.has_prototype_slot()) {
-      Object proto_or_map = js_fun.prototype_or_initial_map();
+      Object proto_or_map = js_fun.prototype_or_initial_map(kAcquireLoad);
       if (!proto_or_map.IsTheHole(isolate)) {
         if (!proto_or_map.IsMap()) {
           SetPropertyReference(entry, roots.prototype_string(), proto_or_map,
@@ -1246,6 +1268,11 @@ class JSArrayBufferDataEntryAllocator : public HeapEntriesAllocator {
                                HeapEntry::kNative, "system / JSArrayBufferData",
                                size_);
   }
+  HeapEntry* AllocateEntry(Smi smi) override {
+    DCHECK(false);
+    return nullptr;
+  }
+
  private:
   size_t size_;
   V8HeapExplorer* explorer_;
@@ -1291,6 +1318,30 @@ void V8HeapExplorer::ExtractFixedArrayReferences(HeapEntry* entry,
   }
 }
 
+void V8HeapExplorer::ExtractNumberReference(HeapEntry* entry, Object number) {
+  DCHECK(number.IsNumber());
+
+  // Must be large enough to fit any double, int, or size_t.
+  char arr[32];
+  Vector<char> buffer(arr, arraysize(arr));
+
+  const char* string;
+  if (number.IsSmi()) {
+    int int_value = Smi::ToInt(number);
+    string = IntToCString(int_value, buffer);
+  } else {
+    double double_value = HeapNumber::cast(number).value();
+    string = DoubleToCString(double_value, buffer);
+  }
+
+  const char* name = names_->GetCopy(string);
+
+  SnapshotObjectId id = heap_object_map_->get_next_id();
+  HeapEntry* child_entry =
+      snapshot_->AddEntry(HeapEntry::kString, name, id, 0, 0);
+  entry->SetNamedReference(HeapGraphEdge::kInternal, "value", child_entry);
+}
+
 void V8HeapExplorer::ExtractFeedbackVectorReferences(
     HeapEntry* entry, FeedbackVector feedback_vector) {
   MaybeObject code = feedback_vector.maybe_optimized_code();
@@ -1345,8 +1396,10 @@ void V8HeapExplorer::ExtractPropertyReferences(JSObject js_obj,
       PropertyDetails details = descs.GetDetails(i);
       switch (details.location()) {
         case kField: {
-          Representation r = details.representation();
-          if (r.IsSmi() || r.IsDouble()) break;
+          if (!snapshot_->capture_numeric_value()) {
+            Representation r = details.representation();
+            if (r.IsSmi() || r.IsDouble()) break;
+          }
 
           Name k = descs.GetKey(i);
           FieldIndex field_index = FieldIndex::ForDescriptor(js_obj.map(), i);
@@ -1476,9 +1529,15 @@ String V8HeapExplorer::GetConstructorName(JSObject object) {
 }
 
 HeapEntry* V8HeapExplorer::GetEntry(Object obj) {
-  return obj.IsHeapObject() ? generator_->FindOrAddEntry(
-                                  reinterpret_cast<void*>(obj.ptr()), this)
-                            : nullptr;
+  if (obj.IsHeapObject()) {
+    return generator_->FindOrAddEntry(reinterpret_cast<void*>(obj.ptr()), this);
+  }
+
+  DCHECK(obj.IsSmi());
+  if (!snapshot_->capture_numeric_value()) {
+    return nullptr;
+  }
+  return generator_->FindOrAddEntry(Smi::cast(obj), this);
 }
 
 class RootsReferencesExtractor : public RootVisitor {
@@ -1500,6 +1559,7 @@ class RootsReferencesExtractor : public RootVisitor {
   void VisitRootPointers(Root root, const char* description,
                          FullObjectSlot start, FullObjectSlot end) override {
     for (FullObjectSlot p = start; p < end; ++p) {
+      DCHECK(!MapWord::IsPacked(p.Relaxed_Load().ptr()));
       VisitRootPointer(root, description, p);
     }
   }
@@ -1649,23 +1709,25 @@ void V8HeapExplorer::SetElementReference(HeapEntry* parent_entry, int index,
 void V8HeapExplorer::SetInternalReference(HeapEntry* parent_entry,
                                           const char* reference_name,
                                           Object child_obj, int field_offset) {
-  HeapEntry* child_entry = GetEntry(child_obj);
-  if (child_entry == nullptr) return;
-  if (IsEssentialObject(child_obj)) {
-    parent_entry->SetNamedReference(HeapGraphEdge::kInternal, reference_name,
-                                    child_entry);
+  if (!IsEssentialObject(child_obj)) {
+    return;
   }
+  HeapEntry* child_entry = GetEntry(child_obj);
+  DCHECK_NOT_NULL(child_entry);
+  parent_entry->SetNamedReference(HeapGraphEdge::kInternal, reference_name,
+                                  child_entry);
   MarkVisitedField(field_offset);
 }
 
 void V8HeapExplorer::SetInternalReference(HeapEntry* parent_entry, int index,
                                           Object child_obj, int field_offset) {
-  HeapEntry* child_entry = GetEntry(child_obj);
-  if (child_entry == nullptr) return;
-  if (IsEssentialObject(child_obj)) {
-    parent_entry->SetNamedReference(HeapGraphEdge::kInternal,
-                                    names_->GetName(index), child_entry);
+  if (!IsEssentialObject(child_obj)) {
+    return;
   }
+  HeapEntry* child_entry = GetEntry(child_obj);
+  DCHECK_NOT_NULL(child_entry);
+  parent_entry->SetNamedReference(HeapGraphEdge::kInternal,
+                                  names_->GetName(index), child_entry);
   MarkVisitedField(field_offset);
 }
 
@@ -1673,9 +1735,13 @@ void V8HeapExplorer::SetHiddenReference(HeapObject parent_obj,
                                         HeapEntry* parent_entry, int index,
                                         Object child_obj, int field_offset) {
   DCHECK_EQ(parent_entry, GetEntry(parent_obj));
+  DCHECK(!MapWord::IsPacked(child_obj.ptr()));
+  if (!IsEssentialObject(child_obj)) {
+    return;
+  }
   HeapEntry* child_entry = GetEntry(child_obj);
-  if (child_entry != nullptr && IsEssentialObject(child_obj) &&
-      IsEssentialHiddenReference(parent_obj, field_offset)) {
+  DCHECK_NOT_NULL(child_entry);
+  if (IsEssentialHiddenReference(parent_obj, field_offset)) {
     parent_entry->SetIndexedReference(HeapGraphEdge::kHidden, index,
                                       child_entry);
   }
@@ -1684,23 +1750,25 @@ void V8HeapExplorer::SetHiddenReference(HeapObject parent_obj,
 void V8HeapExplorer::SetWeakReference(HeapEntry* parent_entry,
                                       const char* reference_name,
                                       Object child_obj, int field_offset) {
-  HeapEntry* child_entry = GetEntry(child_obj);
-  if (child_entry == nullptr) return;
-  if (IsEssentialObject(child_obj)) {
-    parent_entry->SetNamedReference(HeapGraphEdge::kWeak, reference_name,
-                                    child_entry);
+  if (!IsEssentialObject(child_obj)) {
+    return;
   }
+  HeapEntry* child_entry = GetEntry(child_obj);
+  DCHECK_NOT_NULL(child_entry);
+  parent_entry->SetNamedReference(HeapGraphEdge::kWeak, reference_name,
+                                  child_entry);
   MarkVisitedField(field_offset);
 }
 
 void V8HeapExplorer::SetWeakReference(HeapEntry* parent_entry, int index,
                                       Object child_obj, int field_offset) {
-  HeapEntry* child_entry = GetEntry(child_obj);
-  if (child_entry == nullptr) return;
-  if (IsEssentialObject(child_obj)) {
-    parent_entry->SetNamedReference(
-        HeapGraphEdge::kWeak, names_->GetFormatted("%d", index), child_entry);
+  if (!IsEssentialObject(child_obj)) {
+    return;
   }
+  HeapEntry* child_entry = GetEntry(child_obj);
+  DCHECK_NOT_NULL(child_entry);
+  parent_entry->SetNamedReference(
+      HeapGraphEdge::kWeak, names_->GetFormatted("%d", index), child_entry);
   MarkVisitedField(field_offset);
 }
 
@@ -1758,6 +1826,13 @@ void V8HeapExplorer::SetGcRootsReference(Root root) {
 
 void V8HeapExplorer::SetGcSubrootReference(Root root, const char* description,
                                            bool is_weak, Object child_obj) {
+  if (child_obj.IsSmi()) {
+    // TODO(arenevier): if we handle smis here, the snapshot gets 2 to 3 times
+    // slower on large heaps. According to perf, The bulk of the extra works
+    // happens in TemplateHashMapImpl::Probe method, when tyring to get
+    // names->GetFormatted("%d / %s", index, description)
+    return;
+  }
   HeapEntry* child_entry = GetEntry(child_obj);
   if (child_entry == nullptr) return;
   const char* name = GetStrongGcSubrootName(child_obj);
@@ -1834,6 +1909,7 @@ class GlobalObjectsEnumerator : public RootVisitor {
   void VisitRootPointersImpl(Root root, const char* description, TSlot start,
                              TSlot end) {
     for (TSlot p = start; p < end; ++p) {
+      DCHECK(!MapWord::IsPacked(p.Relaxed_Load(isolate_).ptr()));
       Object o = p.load(isolate_);
       if (!o.IsNativeContext(isolate_)) continue;
       JSObject proxy = Context::cast(o).global_proxy();
@@ -1934,6 +2010,7 @@ class EmbedderGraphEntriesAllocator : public HeapEntriesAllocator {
         names_(snapshot_->profiler()->names()),
         heap_object_map_(snapshot_->profiler()->heap_object_map()) {}
   HeapEntry* AllocateEntry(HeapThing ptr) override;
+  HeapEntry* AllocateEntry(Smi smi) override;
 
  private:
   HeapSnapshot* snapshot_;
@@ -1984,6 +2061,11 @@ HeapEntry* EmbedderGraphEntriesAllocator::AllocateEntry(HeapThing ptr) {
   return heap_entry;
 }
 
+HeapEntry* EmbedderGraphEntriesAllocator::AllocateEntry(Smi smi) {
+  DCHECK(false);
+  return nullptr;
+}
+
 NativeObjectsExplorer::NativeObjectsExplorer(
     HeapSnapshot* snapshot, SnapshottingProgressReportingInterface* progress)
     : isolate_(
diff --git a/chromium/v8/src/profiler/heap-snapshot-generator.h b/chromium/v8/src/profiler/heap-snapshot-generator.h
index 12fd9450a9b..2ab13a99bf3 100644
--- a/chromium/v8/src/profiler/heap-snapshot-generator.h
+++ b/chromium/v8/src/profiler/heap-snapshot-generator.h
@@ -188,7 +188,8 @@ class HeapEntry {
 // HeapSnapshotGenerator fills in a HeapSnapshot.
 class HeapSnapshot {
  public:
-  explicit HeapSnapshot(HeapProfiler* profiler, bool global_objects_as_roots);
+  explicit HeapSnapshot(HeapProfiler* profiler, bool global_objects_as_roots,
+                        bool capture_numeric_value);
   HeapSnapshot(const HeapSnapshot&) = delete;
   HeapSnapshot& operator=(const HeapSnapshot&) = delete;
   void Delete();
@@ -213,6 +214,7 @@ class HeapSnapshot {
   bool treat_global_objects_as_roots() const {
     return treat_global_objects_as_roots_;
   }
+  bool capture_numeric_value() const { return capture_numeric_value_; }
 
   void AddLocation(HeapEntry* entry, int scriptId, int line, int col);
   HeapEntry* AddEntry(HeapEntry::Type type,
@@ -245,6 +247,7 @@ class HeapSnapshot {
   std::vector<SourceLocation> locations_;
   SnapshotObjectId max_snapshot_js_object_id_ = -1;
   bool treat_global_objects_as_roots_;
+  bool capture_numeric_value_;
 };
 
 
@@ -277,6 +280,10 @@ class HeapObjectsMap {
   SnapshotObjectId last_assigned_id() const {
     return next_id_ - kObjectIdStep;
   }
+  SnapshotObjectId get_next_id() {
+    next_id_ += kObjectIdStep;
+    return next_id_ - kObjectIdStep;
+  }
 
   void StopHeapObjectsTracking();
   SnapshotObjectId PushHeapObjectsStats(OutputStream* stream,
@@ -322,6 +329,7 @@ class HeapEntriesAllocator {
  public:
   virtual ~HeapEntriesAllocator() = default;
   virtual HeapEntry* AllocateEntry(HeapThing ptr) = 0;
+  virtual HeapEntry* AllocateEntry(Smi smi) = 0;
 };
 
 class SnapshottingProgressReportingInterface {
@@ -342,6 +350,7 @@ class V8_EXPORT_PRIVATE V8HeapExplorer : public HeapEntriesAllocator {
   V8HeapExplorer& operator=(const V8HeapExplorer&) = delete;
 
   HeapEntry* AllocateEntry(HeapThing ptr) override;
+  HeapEntry* AllocateEntry(Smi smi) override;
   int EstimateObjectsCount();
   bool IterateAndExtractReferences(HeapSnapshotGenerator* generator);
   void CollectGlobalObjectsTags();
@@ -397,6 +406,7 @@ class V8_EXPORT_PRIVATE V8HeapExplorer : public HeapEntriesAllocator {
   void ExtractJSGeneratorObjectReferences(HeapEntry* entry,
                                           JSGeneratorObject generator);
   void ExtractFixedArrayReferences(HeapEntry* entry, FixedArray array);
+  void ExtractNumberReference(HeapEntry* entry, Object number);
   void ExtractFeedbackVectorReferences(HeapEntry* entry,
                                        FeedbackVector feedback_vector);
   void ExtractDescriptorArrayReferences(HeapEntry* entry,
@@ -501,6 +511,9 @@ class HeapSnapshotGenerator : public SnapshottingProgressReportingInterface {
   // The HeapEntriesMap instance is used to track a mapping between
   // real heap objects and their representations in heap snapshots.
   using HeapEntriesMap = std::unordered_map<HeapThing, HeapEntry*>;
+  // The SmiEntriesMap instance is used to track a mapping between smi and
+  // their representations in heap snapshots.
+  using SmiEntriesMap = std::unordered_map<int, HeapEntry*>;
 
   HeapSnapshotGenerator(HeapSnapshot* snapshot,
                         v8::ActivityControl* control,
@@ -515,16 +528,31 @@ class HeapSnapshotGenerator : public SnapshottingProgressReportingInterface {
     return it != entries_map_.end() ? it->second : nullptr;
   }
 
+  HeapEntry* FindEntry(Smi smi) {
+    auto it = smis_map_.find(smi.value());
+    return it != smis_map_.end() ? it->second : nullptr;
+  }
+
   HeapEntry* AddEntry(HeapThing ptr, HeapEntriesAllocator* allocator) {
     return entries_map_.emplace(ptr, allocator->AllocateEntry(ptr))
         .first->second;
   }
 
+  HeapEntry* AddEntry(Smi smi, HeapEntriesAllocator* allocator) {
+    return smis_map_.emplace(smi.value(), allocator->AllocateEntry(smi))
+        .first->second;
+  }
+
   HeapEntry* FindOrAddEntry(HeapThing ptr, HeapEntriesAllocator* allocator) {
     HeapEntry* entry = FindEntry(ptr);
     return entry != nullptr ? entry : AddEntry(ptr, allocator);
   }
 
+  HeapEntry* FindOrAddEntry(Smi smi, HeapEntriesAllocator* allocator) {
+    HeapEntry* entry = FindEntry(smi);
+    return entry != nullptr ? entry : AddEntry(smi, allocator);
+  }
+
  private:
   bool FillReferences();
   void ProgressStep() override;
@@ -537,6 +565,7 @@ class HeapSnapshotGenerator : public SnapshottingProgressReportingInterface {
   NativeObjectsExplorer dom_explorer_;
   // Mapping from HeapThing pointers to HeapEntry indices.
   HeapEntriesMap entries_map_;
+  SmiEntriesMap smis_map_;
   // Used during snapshot generation.
   int progress_counter_;
   int progress_total_;
diff --git a/chromium/v8/src/profiler/profile-generator.cc b/chromium/v8/src/profiler/profile-generator.cc
index 375079de3e8..93075d4f7c2 100644
--- a/chromium/v8/src/profiler/profile-generator.cc
+++ b/chromium/v8/src/profiler/profile-generator.cc
@@ -533,6 +533,12 @@ void ProfileTree::TraverseDepthFirst(Callback* callback) {
   }
 }
 
+void ContextFilter::OnMoveEvent(Address from_address, Address to_address) {
+  if (native_context_address() != from_address) return;
+
+  set_native_context_address(to_address);
+}
+
 using v8::tracing::TracedValue;
 
 std::atomic<uint32_t> CpuProfile::last_id_;
@@ -557,6 +563,13 @@ CpuProfile::CpuProfile(CpuProfiler* profiler, const char* title,
   value->SetDouble("startTime", start_time_.since_origin().InMicroseconds());
   TRACE_EVENT_SAMPLE_WITH_ID1(TRACE_DISABLED_BY_DEFAULT("v8.cpu_profiler"),
                               "Profile", id_, "data", std::move(value));
+
+  DisallowHeapAllocation no_gc;
+  if (options_.has_filter_context()) {
+    i::Address raw_filter_context =
+        reinterpret_cast<i::Address>(options_.raw_filter_context());
+    context_filter_.set_native_context_address(raw_filter_context);
+  }
 }
 
 bool CpuProfile::CheckSubsample(base::TimeDelta source_sampling_interval) {
@@ -706,6 +719,8 @@ void CpuProfile::StreamPendingTraceEvents() {
 
 void CpuProfile::FinishProfile() {
   end_time_ = base::TimeTicks::HighResolutionNow();
+  // Stop tracking context movements after profiling stops.
+  context_filter_.set_native_context_address(kNullAddress);
   StreamPendingTraceEvents();
   auto value = TracedValue::Create();
   // The endTime timestamp is not converted to Perfetto's clock domain and will
@@ -942,14 +957,26 @@ base::TimeDelta CpuProfilesCollection::GetCommonSamplingInterval() const {
 
 void CpuProfilesCollection::AddPathToCurrentProfiles(
     base::TimeTicks timestamp, const ProfileStackTrace& path, int src_line,
-    bool update_stats, base::TimeDelta sampling_interval) {
+    bool update_stats, base::TimeDelta sampling_interval,
+    Address native_context_address) {
   // As starting / stopping profiles is rare relatively to this
   // method, we don't bother minimizing the duration of lock holding,
   // e.g. copying contents of the list to a local vector.
   current_profiles_semaphore_.Wait();
   for (const std::unique_ptr<CpuProfile>& profile : current_profiles_) {
-    profile->AddPath(timestamp, path, src_line, update_stats,
-                     sampling_interval);
+    if (profile->context_filter().Accept(native_context_address)) {
+      profile->AddPath(timestamp, path, src_line, update_stats,
+                       sampling_interval);
+    }
+  }
+  current_profiles_semaphore_.Signal();
+}
+
+void CpuProfilesCollection::UpdateNativeContextAddressForCurrentProfiles(
+    Address from, Address to) {
+  current_profiles_semaphore_.Wait();
+  for (const std::unique_ptr<CpuProfile>& profile : current_profiles_) {
+    profile->context_filter().OnMoveEvent(from, to);
   }
   current_profiles_semaphore_.Signal();
 }
diff --git a/chromium/v8/src/profiler/profile-generator.h b/chromium/v8/src/profiler/profile-generator.h
index 551dfdf5917..c4bffa945a0 100644
--- a/chromium/v8/src/profiler/profile-generator.h
+++ b/chromium/v8/src/profiler/profile-generator.h
@@ -237,6 +237,31 @@ struct CodeEntryAndLineNumber {
 
 using ProfileStackTrace = std::vector<CodeEntryAndLineNumber>;
 
+// Filters stack frames from sources other than a target native context.
+class ContextFilter {
+ public:
+  explicit ContextFilter(Address native_context_address = kNullAddress)
+      : native_context_address_(native_context_address) {}
+
+  // Invoked when a native context has changed address.
+  void OnMoveEvent(Address from_address, Address to_address);
+
+  bool Accept(Address native_context_address) const {
+    if (native_context_address_ == kNullAddress) return true;
+    return (native_context_address & ~kHeapObjectTag) ==
+           native_context_address_;
+  }
+
+  // Update the context's tracked address based on VM-thread events.
+  void set_native_context_address(Address address) {
+    native_context_address_ = address;
+  }
+  Address native_context_address() const { return native_context_address_; }
+
+ private:
+  Address native_context_address_;
+};
+
 class ProfileTree;
 
 class V8_EXPORT_PRIVATE ProfileNode {
@@ -386,6 +411,7 @@ class CpuProfile {
   base::TimeTicks start_time() const { return start_time_; }
   base::TimeTicks end_time() const { return end_time_; }
   CpuProfiler* cpu_profiler() const { return profiler_; }
+  ContextFilter& context_filter() { return context_filter_; }
 
   void UpdateTicksScale();
 
@@ -397,6 +423,7 @@ class CpuProfile {
   const char* title_;
   const CpuProfilingOptions options_;
   std::unique_ptr<DiscardedSamplesDelegate> delegate_;
+  ContextFilter context_filter_;
   base::TimeTicks start_time_;
   base::TimeTicks end_time_;
   std::deque<SampleInfo> samples_;
@@ -486,7 +513,11 @@ class V8_EXPORT_PRIVATE CpuProfilesCollection {
   void AddPathToCurrentProfiles(base::TimeTicks timestamp,
                                 const ProfileStackTrace& path, int src_line,
                                 bool update_stats,
-                                base::TimeDelta sampling_interval);
+                                base::TimeDelta sampling_interval,
+                                Address native_context_address = kNullAddress);
+
+  // Called from profile generator thread.
+  void UpdateNativeContextAddressForCurrentProfiles(Address from, Address to);
 
   // Limits the number of profiles that can be simultaneously collected.
   static const int kMaxSimultaneousProfiles = 100;
diff --git a/chromium/v8/src/profiler/profiler-listener.cc b/chromium/v8/src/profiler/profiler-listener.cc
index 8b253fb4729..a2cfb8b07b2 100644
--- a/chromium/v8/src/profiler/profiler-listener.cc
+++ b/chromium/v8/src/profiler/profiler-listener.cc
@@ -302,6 +302,13 @@ void ProfilerListener::CodeMoveEvent(AbstractCode from, AbstractCode to) {
   DispatchCodeEvent(evt_rec);
 }
 
+void ProfilerListener::NativeContextMoveEvent(Address from, Address to) {
+  CodeEventsContainer evt_rec(CodeEventRecord::NATIVE_CONTEXT_MOVE);
+  evt_rec.NativeContextMoveEventRecord_.from_address = from;
+  evt_rec.NativeContextMoveEventRecord_.to_address = to;
+  DispatchCodeEvent(evt_rec);
+}
+
 void ProfilerListener::CodeDisableOptEvent(Handle<AbstractCode> code,
                                            Handle<SharedFunctionInfo> shared) {
   CodeEventsContainer evt_rec(CodeEventRecord::CODE_DISABLE_OPT);
diff --git a/chromium/v8/src/profiler/profiler-listener.h b/chromium/v8/src/profiler/profiler-listener.h
index 49e7db32baa..50a9b818936 100644
--- a/chromium/v8/src/profiler/profiler-listener.h
+++ b/chromium/v8/src/profiler/profiler-listener.h
@@ -59,6 +59,7 @@ class V8_EXPORT_PRIVATE ProfilerListener : public CodeEventListener,
                              Handle<String> source) override;
   void CodeMoveEvent(AbstractCode from, AbstractCode to) override;
   void SharedFunctionInfoMoveEvent(Address from, Address to) override {}
+  void NativeContextMoveEvent(Address from, Address to) override;
   void CodeMovingGCEvent() override {}
   void CodeDisableOptEvent(Handle<AbstractCode> code,
                            Handle<SharedFunctionInfo> shared) override;
diff --git a/chromium/v8/src/profiler/sampling-heap-profiler.cc b/chromium/v8/src/profiler/sampling-heap-profiler.cc
index aef0170bb48..4bef9793abf 100644
--- a/chromium/v8/src/profiler/sampling-heap-profiler.cc
+++ b/chromium/v8/src/profiler/sampling-heap-profiler.cc
@@ -75,7 +75,7 @@ void SamplingHeapProfiler::SampleObject(Address soon_object, size_t size) {
   DisallowGarbageCollection no_gc;
 
   // Check if the area is iterable by confirming that it starts with a map.
-  DCHECK((*ObjectSlot(soon_object)).IsMap());
+  DCHECK(HeapObject::FromAddress(soon_object).map().IsMap());
 
   HandleScope scope(isolate_);
   HeapObject heap_object = HeapObject::FromAddress(soon_object);
diff --git a/chromium/v8/src/profiler/tick-sample.cc b/chromium/v8/src/profiler/tick-sample.cc
index 638aa5545a1..253b80d19e2 100644
--- a/chromium/v8/src/profiler/tick-sample.cc
+++ b/chromium/v8/src/profiler/tick-sample.cc
@@ -7,14 +7,14 @@
 #include <cinttypes>
 
 #include "include/v8-profiler.h"
+#include "src/base/sanitizer/asan.h"
+#include "src/base/sanitizer/msan.h"
 #include "src/execution/frames-inl.h"
 #include "src/execution/simulator.h"
 #include "src/execution/vm-state-inl.h"
 #include "src/heap/heap-inl.h"  // For Heap::code_range.
 #include "src/logging/counters.h"
 #include "src/profiler/profiler-stats.h"
-#include "src/sanitizer/asan.h"
-#include "src/sanitizer/msan.h"
 
 namespace v8 {
 namespace internal {
@@ -177,6 +177,7 @@ DISABLE_ASAN void TickSample::Init(Isolate* v8_isolate,
   pc = regs.pc;
   frames_count = static_cast<unsigned>(info.frames_count);
   has_external_callback = info.external_callback_entry != nullptr;
+  context = info.context;
   if (has_external_callback) {
     external_callback_entry = info.external_callback_entry;
   } else if (frames_count) {
@@ -209,6 +210,7 @@ bool TickSample::GetStackSample(Isolate* v8_isolate, RegisterState* regs,
   sample_info->frames_count = 0;
   sample_info->vm_state = isolate->current_vm_state();
   sample_info->external_callback_entry = nullptr;
+  sample_info->context = nullptr;
   if (sample_info->vm_state == GC) return true;
 
   i::Address js_entry_sp = isolate->js_entry_sp();
@@ -232,7 +234,7 @@ bool TickSample::GetStackSample(Isolate* v8_isolate, RegisterState* regs,
   // TODO(petermarshall): Code range is always null on ia32 so this check for
   // IsNoFrameRegion will never actually run there.
   if (regs->pc &&
-      isolate->heap()->memory_allocator()->code_range().contains(
+      isolate->heap()->code_region().contains(
           reinterpret_cast<i::Address>(regs->pc)) &&
       IsNoFrameRegion(reinterpret_cast<i::Address>(regs->pc))) {
     // The frame is not setup, so it'd be hard to iterate the stack. Bailout.
@@ -278,6 +280,13 @@ bool TickSample::GetStackSample(Isolate* v8_isolate, RegisterState* regs,
                                reinterpret_cast<i::Address>(regs->lr),
                                js_entry_sp);
 
+  Context top_context = isolate->context();
+  if (top_context.ptr() != i::Context::kNoContext &&
+      top_context.ptr() != i::Context::kInvalidContext) {
+    NativeContext top_native_context = top_context.native_context();
+    sample_info->context = reinterpret_cast<void*>(top_native_context.ptr());
+  }
+
   if (it.done()) return true;
 
   size_t i = 0;
@@ -287,15 +296,18 @@ bool TickSample::GetStackSample(Isolate* v8_isolate, RegisterState* regs,
     frames[i] = reinterpret_cast<void*>(isolate->c_function());
     i++;
   }
-
+#ifdef V8_RUNTIME_CALL_STATS
   i::RuntimeCallTimer* timer =
       isolate->counters()->runtime_call_stats()->current_timer();
+#endif  // V8_RUNTIME_CALL_STATS
   for (; !it.done() && i < frames_limit; it.Advance()) {
+#ifdef V8_RUNTIME_CALL_STATS
     while (timer && reinterpret_cast<i::Address>(timer) < it.frame()->fp() &&
            i < frames_limit) {
       frames[i++] = reinterpret_cast<void*>(timer->counter());
       timer = timer->parent();
     }
+#endif  // V8_RUNTIME_CALL_STATS
     if (i == frames_limit) break;
 
     if (it.frame()->is_interpreted()) {
diff --git a/chromium/v8/src/profiler/tick-sample.h b/chromium/v8/src/profiler/tick-sample.h
index 777c3d192dc..1bfcb7d0971 100644
--- a/chromium/v8/src/profiler/tick-sample.h
+++ b/chromium/v8/src/profiler/tick-sample.h
@@ -90,6 +90,7 @@ struct V8_EXPORT TickSample {
   static const unsigned kMaxFramesCountLog2 = 8;
   static const unsigned kMaxFramesCount = (1 << kMaxFramesCountLog2) - 1;
   void* stack[kMaxFramesCount];     // Call stack.
+  void* context = nullptr;          // Address of the incumbent native context.
   unsigned frames_count : kMaxFramesCountLog2;  // Number of captured frames.
   bool has_external_callback : 1;
   bool update_stats : 1;  // Whether the sample should update aggregated stats.
diff --git a/chromium/v8/src/regexp/arm64/regexp-macro-assembler-arm64.cc b/chromium/v8/src/regexp/arm64/regexp-macro-assembler-arm64.cc
index 0441fe29763..5e24500a261 100644
--- a/chromium/v8/src/regexp/arm64/regexp-macro-assembler-arm64.cc
+++ b/chromium/v8/src/regexp/arm64/regexp-macro-assembler-arm64.cc
@@ -395,7 +395,7 @@ void RegExpMacroAssemblerARM64::CheckNotBackReferenceIgnoreCase(
       __ Sub(current_input_offset().X(), current_input_offset().X(),
              Operand(capture_length, SXTW));
     }
-    if (masm_->emit_debug_code()) {
+    if (FLAG_debug_code) {
       __ Cmp(current_input_offset().X(), Operand(current_input_offset(), SXTW));
       __ Ccmp(current_input_offset(), 0, NoFlag, eq);
       // The current input offset should be <= 0, and fit in a W register.
@@ -528,7 +528,7 @@ void RegExpMacroAssemblerARM64::CheckNotBackReference(int start_reg,
            Operand(capture_length, SXTW));
   }
 
-  if (masm_->emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ Cmp(current_input_offset().X(), Operand(current_input_offset(), SXTW));
     __ Ccmp(current_input_offset(), 0, NoFlag, eq);
     // The current input offset should be <= 0, and fit in a W register.
@@ -817,7 +817,7 @@ Handle<HeapObject> RegExpMacroAssemblerARM64::GetCode(Handle<String> source) {
 
   // Find negative length (offset of start relative to end).
   __ Sub(x10, input_start(), input_end());
-  if (masm_->emit_debug_code()) {
+  if (FLAG_debug_code) {
     // Check that the size of the input string chars is in range.
     __ Neg(x11, x10);
     __ Cmp(x11, SeqTwoByteString::kMaxCharsSize);
@@ -882,7 +882,7 @@ Handle<HeapObject> RegExpMacroAssemblerARM64::GetCode(Handle<String> source) {
 
       // Get string length.
       __ Sub(x10, input_end(), input_start());
-      if (masm_->emit_debug_code()) {
+      if (FLAG_debug_code) {
         // Check that the size of the input string chars is in range.
         __ Cmp(x10, SeqTwoByteString::kMaxCharsSize);
         __ Check(ls, AbortReason::kInputStringTooLong);
@@ -1167,7 +1167,7 @@ void RegExpMacroAssemblerARM64::PushBacktrack(Label* label) {
   } else {
     __ Adr(x10, label, MacroAssembler::kAdrFar);
     __ Sub(x10, x10, code_pointer());
-    if (masm_->emit_debug_code()) {
+    if (FLAG_debug_code) {
       __ Cmp(x10, kWRegMask);
       // The code offset has to fit in a W register.
       __ Check(ls, AbortReason::kOffsetOutOfRange);
@@ -1322,7 +1322,7 @@ void RegExpMacroAssemblerARM64::ClearRegisters(int reg_from, int reg_to) {
 void RegExpMacroAssemblerARM64::WriteStackPointerToRegister(int reg) {
   __ Ldr(x10, MemOperand(frame_pointer(), kStackBase));
   __ Sub(x10, backtrack_stackpointer(), x10);
-  if (masm_->emit_debug_code()) {
+  if (FLAG_debug_code) {
     __ Cmp(x10, Operand(w10, SXTW));
     // The stack offset needs to fit in a W register.
     __ Check(eq, AbortReason::kOffsetOutOfRange);
@@ -1629,7 +1629,7 @@ void RegExpMacroAssemblerARM64::LoadCurrentCharacterUnchecked(int cp_offset,
   }
 
   if (cp_offset != 0) {
-    if (masm_->emit_debug_code()) {
+    if (FLAG_debug_code) {
       __ Mov(x10, cp_offset * char_size());
       __ Add(x10, x10, Operand(current_input_offset(), SXTW));
       __ Cmp(x10, Operand(w10, SXTW));
diff --git a/chromium/v8/src/regexp/ppc/OWNERS b/chromium/v8/src/regexp/ppc/OWNERS
deleted file mode 100644
index 02c2cd757c9..00000000000
--- a/chromium/v8/src/regexp/ppc/OWNERS
+++ /dev/null
@@ -1,5 +0,0 @@
-junyan@redhat.com
-joransiu@ca.ibm.com
-midawson@redhat.com
-mfarazma@redhat.com
-vasili.skurydzin@ibm.com
diff --git a/chromium/v8/src/regexp/ppc/regexp-macro-assembler-ppc.cc b/chromium/v8/src/regexp/ppc/regexp-macro-assembler-ppc.cc
index c0d69297f99..77a09526372 100644
--- a/chromium/v8/src/regexp/ppc/regexp-macro-assembler-ppc.cc
+++ b/chromium/v8/src/regexp/ppc/regexp-macro-assembler-ppc.cc
@@ -162,7 +162,7 @@ void RegExpMacroAssemblerPPC::AdvanceRegister(int reg, int by) {
   DCHECK_LE(0, reg);
   DCHECK_GT(num_registers_, reg);
   if (by != 0) {
-    __ LoadP(r3, register_location(reg), r0);
+    __ LoadU64(r3, register_location(reg), r0);
     __ mov(r0, Operand(by));
     __ add(r3, r3, r0);
     __ StoreP(r3, register_location(reg), r0);
@@ -174,7 +174,7 @@ void RegExpMacroAssemblerPPC::Backtrack() {
   CheckPreemption();
   if (has_backtrack_limit()) {
     Label next;
-    __ LoadP(r3, MemOperand(frame_pointer(), kBacktrackCount), r0);
+    __ LoadU64(r3, MemOperand(frame_pointer(), kBacktrackCount), r0);
     __ addi(r3, r3, Operand(1));
     __ StoreP(r3, MemOperand(frame_pointer(), kBacktrackCount), r0);
     __ mov(r0, Operand(backtrack_limit()));
@@ -213,7 +213,7 @@ void RegExpMacroAssemblerPPC::CheckCharacterGT(uc16 limit, Label* on_greater) {
 }
 
 void RegExpMacroAssemblerPPC::CheckAtStart(int cp_offset, Label* on_at_start) {
-  __ LoadP(r4, MemOperand(frame_pointer(), kStringStartMinusOne));
+  __ LoadU64(r4, MemOperand(frame_pointer(), kStringStartMinusOne));
   __ addi(r3, current_input_offset(),
           Operand(-char_size() + cp_offset * char_size()));
   __ cmp(r3, r4);
@@ -222,7 +222,7 @@ void RegExpMacroAssemblerPPC::CheckAtStart(int cp_offset, Label* on_at_start) {
 
 void RegExpMacroAssemblerPPC::CheckNotAtStart(int cp_offset,
                                               Label* on_not_at_start) {
-  __ LoadP(r4, MemOperand(frame_pointer(), kStringStartMinusOne));
+  __ LoadU64(r4, MemOperand(frame_pointer(), kStringStartMinusOne));
   __ addi(r3, current_input_offset(),
           Operand(-char_size() + cp_offset * char_size()));
   __ cmp(r3, r4);
@@ -238,7 +238,7 @@ void RegExpMacroAssemblerPPC::CheckCharacterLT(uc16 limit, Label* on_less) {
 
 void RegExpMacroAssemblerPPC::CheckGreedyLoop(Label* on_equal) {
   Label backtrack_non_equal;
-  __ LoadP(r3, MemOperand(backtrack_stackpointer(), 0));
+  __ LoadU64(r3, MemOperand(backtrack_stackpointer(), 0));
   __ cmp(current_input_offset(), r3);
   __ bne(&backtrack_non_equal);
   __ addi(backtrack_stackpointer(), backtrack_stackpointer(),
@@ -251,8 +251,9 @@ void RegExpMacroAssemblerPPC::CheckGreedyLoop(Label* on_equal) {
 void RegExpMacroAssemblerPPC::CheckNotBackReferenceIgnoreCase(
     int start_reg, bool read_backward, bool unicode, Label* on_no_match) {
   Label fallthrough;
-  __ LoadP(r3, register_location(start_reg), r0);  // Index of start of capture
-  __ LoadP(r4, register_location(start_reg + 1), r0);  // Index of end
+  __ LoadU64(r3, register_location(start_reg),
+             r0);  // Index of start of capture
+  __ LoadU64(r4, register_location(start_reg + 1), r0);  // Index of end
   __ sub(r4, r4, r3, LeaveOE, SetRC);                  // Length of capture.
 
   // At this point, the capture registers are either both set or both cleared.
@@ -262,7 +263,7 @@ void RegExpMacroAssemblerPPC::CheckNotBackReferenceIgnoreCase(
 
   // Check that there are enough characters left in the input.
   if (read_backward) {
-    __ LoadP(r6, MemOperand(frame_pointer(), kStringStartMinusOne));
+    __ LoadU64(r6, MemOperand(frame_pointer(), kStringStartMinusOne));
     __ add(r6, r6, r4);
     __ cmp(current_input_offset(), r6);
     BranchOrBacktrack(le, on_no_match);
@@ -325,9 +326,10 @@ void RegExpMacroAssemblerPPC::CheckNotBackReferenceIgnoreCase(
     // Compute new value of character position after the matched part.
     __ sub(current_input_offset(), r5, end_of_input_address());
     if (read_backward) {
-      __ LoadP(r3, register_location(start_reg));  // Index of start of capture
-      __ LoadP(r4,
-               register_location(start_reg + 1));  // Index of end of capture
+      __ LoadU64(r3,
+                 register_location(start_reg));  // Index of start of capture
+      __ LoadU64(r4,
+                 register_location(start_reg + 1));  // Index of end of capture
       __ add(current_input_offset(), current_input_offset(), r3);
       __ sub(current_input_offset(), current_input_offset(), r4);
     }
@@ -391,8 +393,8 @@ void RegExpMacroAssemblerPPC::CheckNotBackReference(int start_reg,
   Label fallthrough;
 
   // Find length of back-referenced capture.
-  __ LoadP(r3, register_location(start_reg), r0);
-  __ LoadP(r4, register_location(start_reg + 1), r0);
+  __ LoadU64(r3, register_location(start_reg), r0);
+  __ LoadU64(r4, register_location(start_reg + 1), r0);
   __ sub(r4, r4, r3, LeaveOE, SetRC);  // Length to check.
 
   // At this point, the capture registers are either both set or both cleared.
@@ -402,7 +404,7 @@ void RegExpMacroAssemblerPPC::CheckNotBackReference(int start_reg,
 
   // Check that there are enough characters left in the input.
   if (read_backward) {
-    __ LoadP(r6, MemOperand(frame_pointer(), kStringStartMinusOne));
+    __ LoadU64(r6, MemOperand(frame_pointer(), kStringStartMinusOne));
     __ add(r6, r6, r4);
     __ cmp(current_input_offset(), r6);
     BranchOrBacktrack(le, on_no_match);
@@ -442,8 +444,9 @@ void RegExpMacroAssemblerPPC::CheckNotBackReference(int start_reg,
   // Move current character position to position after match.
   __ sub(current_input_offset(), r5, end_of_input_address());
   if (read_backward) {
-    __ LoadP(r3, register_location(start_reg));  // Index of start of capture
-    __ LoadP(r4, register_location(start_reg + 1));  // Index of end of capture
+    __ LoadU64(r3, register_location(start_reg));  // Index of start of capture
+    __ LoadU64(r4,
+               register_location(start_reg + 1));  // Index of end of capture
     __ add(current_input_offset(), current_input_offset(), r3);
     __ sub(current_input_offset(), current_input_offset(), r4);
   }
@@ -715,7 +718,7 @@ Handle<HeapObject> RegExpMacroAssemblerPPC::GetCode(Handle<String> source) {
     ExternalReference stack_limit =
         ExternalReference::address_of_jslimit(isolate());
     __ mov(r3, Operand(stack_limit));
-    __ LoadP(r3, MemOperand(r3));
+    __ LoadU64(r3, MemOperand(r3));
     __ sub(r3, sp, r3, LeaveOE, SetRC);
     // Handle it if the stack pointer is already below the stack limit.
     __ ble(&stack_limit_hit, cr0);
@@ -739,14 +742,14 @@ Handle<HeapObject> RegExpMacroAssemblerPPC::GetCode(Handle<String> source) {
     // Allocate space on stack for registers.
     __ Add(sp, sp, -num_registers_ * kSystemPointerSize, r0);
     // Load string end.
-    __ LoadP(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
+    __ LoadU64(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
     // Load input start.
-    __ LoadP(r3, MemOperand(frame_pointer(), kInputStart));
+    __ LoadU64(r3, MemOperand(frame_pointer(), kInputStart));
     // Find negative length (offset of start relative to end).
     __ sub(current_input_offset(), r3, end_of_input_address());
     // Set r3 to address of char before start of the input string
     // (effectively string position -1).
-    __ LoadP(r4, MemOperand(frame_pointer(), kStartIndex));
+    __ LoadU64(r4, MemOperand(frame_pointer(), kStartIndex));
     __ subi(r3, current_input_offset(), Operand(char_size()));
     if (mode_ == UC16) {
       __ ShiftLeftImm(r0, r4, Operand(1));
@@ -795,8 +798,8 @@ Handle<HeapObject> RegExpMacroAssemblerPPC::GetCode(Handle<String> source) {
     }
 
     // Initialize backtrack stack pointer.
-    __ LoadP(backtrack_stackpointer(),
-             MemOperand(frame_pointer(), kStackHighEnd));
+    __ LoadU64(backtrack_stackpointer(),
+               MemOperand(frame_pointer(), kStackHighEnd));
 
     __ b(&start_label_);
 
@@ -806,9 +809,9 @@ Handle<HeapObject> RegExpMacroAssemblerPPC::GetCode(Handle<String> source) {
       __ bind(&success_label_);
       if (num_saved_registers_ > 0) {
         // copy captures to output
-        __ LoadP(r4, MemOperand(frame_pointer(), kInputStart));
-        __ LoadP(r3, MemOperand(frame_pointer(), kRegisterOutput));
-        __ LoadP(r5, MemOperand(frame_pointer(), kStartIndex));
+        __ LoadU64(r4, MemOperand(frame_pointer(), kInputStart));
+        __ LoadU64(r3, MemOperand(frame_pointer(), kRegisterOutput));
+        __ LoadU64(r5, MemOperand(frame_pointer(), kStartIndex));
         __ sub(r4, end_of_input_address(), r4);
         // r4 is length of input in bytes.
         if (mode_ == UC16) {
@@ -823,8 +826,8 @@ Handle<HeapObject> RegExpMacroAssemblerPPC::GetCode(Handle<String> source) {
         // unroll the loop once to add an operation between a load of a register
         // and the following use of that register.
         for (int i = 0; i < num_saved_registers_; i += 2) {
-          __ LoadP(r5, register_location(i), r0);
-          __ LoadP(r6, register_location(i + 1), r0);
+          __ LoadU64(r5, register_location(i), r0);
+          __ LoadU64(r6, register_location(i + 1), r0);
           if (i == 0 && global_with_zero_length_check()) {
             // Keep capture start in r25 for the zero-length check later.
             __ mr(r25, r5);
@@ -847,9 +850,9 @@ Handle<HeapObject> RegExpMacroAssemblerPPC::GetCode(Handle<String> source) {
 
       if (global()) {
         // Restart matching if the regular expression is flagged as global.
-        __ LoadP(r3, MemOperand(frame_pointer(), kSuccessfulCaptures));
-        __ LoadP(r4, MemOperand(frame_pointer(), kNumOutputRegisters));
-        __ LoadP(r5, MemOperand(frame_pointer(), kRegisterOutput));
+        __ LoadU64(r3, MemOperand(frame_pointer(), kSuccessfulCaptures));
+        __ LoadU64(r4, MemOperand(frame_pointer(), kNumOutputRegisters));
+        __ LoadU64(r5, MemOperand(frame_pointer(), kRegisterOutput));
         // Increment success counter.
         __ addi(r3, r3, Operand(1));
         __ StoreP(r3, MemOperand(frame_pointer(), kSuccessfulCaptures));
@@ -866,7 +869,7 @@ Handle<HeapObject> RegExpMacroAssemblerPPC::GetCode(Handle<String> source) {
         __ StoreP(r5, MemOperand(frame_pointer(), kRegisterOutput));
 
         // Prepare r3 to initialize registers with its value in the next run.
-        __ LoadP(r3, MemOperand(frame_pointer(), kStringStartMinusOne));
+        __ LoadU64(r3, MemOperand(frame_pointer(), kStringStartMinusOne));
 
         if (global_with_zero_length_check()) {
           // Special case for zero-length matches.
@@ -894,7 +897,7 @@ Handle<HeapObject> RegExpMacroAssemblerPPC::GetCode(Handle<String> source) {
     // Exit and return r3
     __ bind(&exit_label_);
     if (global()) {
-      __ LoadP(r3, MemOperand(frame_pointer(), kSuccessfulCaptures));
+      __ LoadU64(r3, MemOperand(frame_pointer(), kSuccessfulCaptures));
     }
 
     __ bind(&return_r3);
@@ -925,7 +928,8 @@ Handle<HeapObject> RegExpMacroAssemblerPPC::GetCode(Handle<String> source) {
       __ bne(&return_r3);
 
       // String might have moved: Reload end of string from frame.
-      __ LoadP(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
+      __ LoadU64(end_of_input_address(),
+                 MemOperand(frame_pointer(), kInputEnd));
       SafeReturn();
     }
 
@@ -984,7 +988,7 @@ void RegExpMacroAssemblerPPC::GoTo(Label* to) { BranchOrBacktrack(al, to); }
 
 void RegExpMacroAssemblerPPC::IfRegisterGE(int reg, int comparand,
                                            Label* if_ge) {
-  __ LoadP(r3, register_location(reg), r0);
+  __ LoadU64(r3, register_location(reg), r0);
   __ Cmpi(r3, Operand(comparand), r0);
   BranchOrBacktrack(ge, if_ge);
 }
@@ -992,14 +996,14 @@ void RegExpMacroAssemblerPPC::IfRegisterGE(int reg, int comparand,
 
 void RegExpMacroAssemblerPPC::IfRegisterLT(int reg, int comparand,
                                            Label* if_lt) {
-  __ LoadP(r3, register_location(reg), r0);
+  __ LoadU64(r3, register_location(reg), r0);
   __ Cmpi(r3, Operand(comparand), r0);
   BranchOrBacktrack(lt, if_lt);
 }
 
 
 void RegExpMacroAssemblerPPC::IfRegisterEqPos(int reg, Label* if_eq) {
-  __ LoadP(r3, register_location(reg), r0);
+  __ LoadU64(r3, register_location(reg), r0);
   __ cmp(r3, current_input_offset());
   BranchOrBacktrack(eq, if_eq);
 }
@@ -1036,20 +1040,20 @@ void RegExpMacroAssemblerPPC::PushCurrentPosition() {
 
 void RegExpMacroAssemblerPPC::PushRegister(int register_index,
                                            StackCheckFlag check_stack_limit) {
-  __ LoadP(r3, register_location(register_index), r0);
+  __ LoadU64(r3, register_location(register_index), r0);
   Push(r3);
   if (check_stack_limit) CheckStackLimit();
 }
 
 
 void RegExpMacroAssemblerPPC::ReadCurrentPositionFromRegister(int reg) {
-  __ LoadP(current_input_offset(), register_location(reg), r0);
+  __ LoadU64(current_input_offset(), register_location(reg), r0);
 }
 
 
 void RegExpMacroAssemblerPPC::ReadStackPointerFromRegister(int reg) {
-  __ LoadP(backtrack_stackpointer(), register_location(reg), r0);
-  __ LoadP(r3, MemOperand(frame_pointer(), kStackHighEnd));
+  __ LoadU64(backtrack_stackpointer(), register_location(reg), r0);
+  __ LoadU64(r3, MemOperand(frame_pointer(), kStackHighEnd));
   __ add(backtrack_stackpointer(), backtrack_stackpointer(), r3);
 }
 
@@ -1094,7 +1098,7 @@ void RegExpMacroAssemblerPPC::WriteCurrentPositionToRegister(int reg,
 
 void RegExpMacroAssemblerPPC::ClearRegisters(int reg_from, int reg_to) {
   DCHECK(reg_from <= reg_to);
-  __ LoadP(r3, MemOperand(frame_pointer(), kStringStartMinusOne));
+  __ LoadU64(r3, MemOperand(frame_pointer(), kStringStartMinusOne));
   for (int reg = reg_from; reg <= reg_to; reg++) {
     __ StoreP(r3, register_location(reg), r0);
   }
@@ -1102,7 +1106,7 @@ void RegExpMacroAssemblerPPC::ClearRegisters(int reg_from, int reg_to) {
 
 
 void RegExpMacroAssemblerPPC::WriteStackPointerToRegister(int reg) {
-  __ LoadP(r4, MemOperand(frame_pointer(), kStackHighEnd));
+  __ LoadU64(r4, MemOperand(frame_pointer(), kStackHighEnd));
   __ sub(r3, backtrack_stackpointer(), r4);
   __ StoreP(r3, register_location(reg), r0);
 }
@@ -1160,7 +1164,7 @@ void RegExpMacroAssemblerPPC::CallCheckStackGuardState(Register scratch) {
   // Restore the stack pointer
   stack_space = kNumRequiredStackFrameSlots + stack_passed_arguments;
   if (frame_alignment > kSystemPointerSize) {
-    __ LoadP(sp, MemOperand(sp, stack_space * kSystemPointerSize));
+    __ LoadU64(sp, MemOperand(sp, stack_space * kSystemPointerSize));
   } else {
     __ addi(sp, sp, Operand(stack_space * kSystemPointerSize));
   }
@@ -1213,7 +1217,7 @@ void RegExpMacroAssemblerPPC::CheckPosition(int cp_offset,
     __ Cmpi(current_input_offset(), Operand(-cp_offset * char_size()), r0);
     BranchOrBacktrack(ge, on_outside_input);
   } else {
-    __ LoadP(r4, MemOperand(frame_pointer(), kStringStartMinusOne));
+    __ LoadU64(r4, MemOperand(frame_pointer(), kStringStartMinusOne));
     __ addi(r3, current_input_offset(), Operand(cp_offset * char_size()));
     __ cmp(r3, r4);
     BranchOrBacktrack(le, on_outside_input);
@@ -1271,7 +1275,7 @@ void RegExpMacroAssemblerPPC::Push(Register source) {
 
 void RegExpMacroAssemblerPPC::Pop(Register target) {
   DCHECK(target != backtrack_stackpointer());
-  __ LoadP(target, MemOperand(backtrack_stackpointer()));
+  __ LoadU64(target, MemOperand(backtrack_stackpointer()));
   __ addi(backtrack_stackpointer(), backtrack_stackpointer(),
           Operand(kSystemPointerSize));
 }
@@ -1282,7 +1286,7 @@ void RegExpMacroAssemblerPPC::CheckPreemption() {
   ExternalReference stack_limit =
       ExternalReference::address_of_jslimit(isolate());
   __ mov(r3, Operand(stack_limit));
-  __ LoadP(r3, MemOperand(r3));
+  __ LoadU64(r3, MemOperand(r3));
   __ cmpl(sp, r3);
   SafeCall(&check_preempt_label_, le);
 }
@@ -1292,7 +1296,7 @@ void RegExpMacroAssemblerPPC::CheckStackLimit() {
   ExternalReference stack_limit =
       ExternalReference::address_of_regexp_stack_limit_address(isolate());
   __ mov(r3, Operand(stack_limit));
-  __ LoadP(r3, MemOperand(r3));
+  __ LoadU64(r3, MemOperand(r3));
   __ cmpl(backtrack_stackpointer(), r3);
   SafeCall(&stack_overflow_label_, le);
 }
diff --git a/chromium/v8/src/regexp/regexp-ast.cc b/chromium/v8/src/regexp/regexp-ast.cc
index dd9e719c948..aaca95b64c9 100644
--- a/chromium/v8/src/regexp/regexp-ast.cc
+++ b/chromium/v8/src/regexp/regexp-ast.cc
@@ -293,14 +293,12 @@ void* RegExpUnparser::VisitEmpty(RegExpEmpty* that, void* data) {
   return nullptr;
 }
 
-
-std::ostream& RegExpTree::Print(std::ostream& os, Zone* zone) {  // NOLINT
+std::ostream& RegExpTree::Print(std::ostream& os, Zone* zone) {
   RegExpUnparser unparser(os, zone);
   Accept(&unparser, nullptr);
   return os;
 }
 
-
 RegExpDisjunction::RegExpDisjunction(ZoneList<RegExpTree*>* alternatives)
     : alternatives_(alternatives) {
   DCHECK_LT(1, alternatives->length());
diff --git a/chromium/v8/src/regexp/regexp-ast.h b/chromium/v8/src/regexp/regexp-ast.h
index c038c640f49..89f523bf2e8 100644
--- a/chromium/v8/src/regexp/regexp-ast.h
+++ b/chromium/v8/src/regexp/regexp-ast.h
@@ -214,8 +214,7 @@ class RegExpTree : public ZoneObject {
   // expression.
   virtual Interval CaptureRegisters() { return Interval::Empty(); }
   virtual void AppendToText(RegExpText* text, Zone* zone);
-  V8_EXPORT_PRIVATE std::ostream& Print(std::ostream& os,
-                                        Zone* zone);  // NOLINT
+  V8_EXPORT_PRIVATE std::ostream& Print(std::ostream& os, Zone* zone);
 #define MAKE_ASTYPE(Name)           \
   virtual RegExp##Name* As##Name(); \
   virtual bool Is##Name();
diff --git a/chromium/v8/src/regexp/regexp-bytecodes.h b/chromium/v8/src/regexp/regexp-bytecodes.h
index e3248d7b837..088fd93b231 100644
--- a/chromium/v8/src/regexp/regexp-bytecodes.h
+++ b/chromium/v8/src/regexp/regexp-bytecodes.h
@@ -231,7 +231,7 @@ static constexpr int kRegExpBytecodeLengths[] = {
 };
 
 inline constexpr int RegExpBytecodeLength(int bytecode) {
-  CONSTEXPR_DCHECK(base::IsInRange(bytecode, 0, kRegExpBytecodeCount - 1));
+  DCHECK(base::IsInRange(bytecode, 0, kRegExpBytecodeCount - 1));
   return kRegExpBytecodeLengths[bytecode];
 }
 
@@ -242,7 +242,7 @@ static constexpr const char* const kRegExpBytecodeNames[] = {
 };
 
 inline constexpr const char* RegExpBytecodeName(int bytecode) {
-  CONSTEXPR_DCHECK(base::IsInRange(bytecode, 0, kRegExpBytecodeCount - 1));
+  DCHECK(base::IsInRange(bytecode, 0, kRegExpBytecodeCount - 1));
   return kRegExpBytecodeNames[bytecode];
 }
 
diff --git a/chromium/v8/src/regexp/regexp-compiler.cc b/chromium/v8/src/regexp/regexp-compiler.cc
index c743ee25631..36661f45f2c 100644
--- a/chromium/v8/src/regexp/regexp-compiler.cc
+++ b/chromium/v8/src/regexp/regexp-compiler.cc
@@ -1435,9 +1435,11 @@ EatsAtLeastInfo LoopChoiceNode::EatsAtLeastFromLoopEntry() {
   DCHECK_EQ(alternatives_->length(), 2);  // There's just loop and continue.
 
   if (read_backward()) {
-    // Can't do anything special for a backward loop, so return the basic values
-    // that we got during analysis.
-    return *eats_at_least_info();
+    // The eats_at_least value is not used if reading backward. The
+    // EatsAtLeastPropagator should've zeroed it as well.
+    DCHECK_EQ(eats_at_least_info()->eats_at_least_from_possibly_start, 0);
+    DCHECK_EQ(eats_at_least_info()->eats_at_least_from_not_start, 0);
+    return {};
   }
 
   // Figure out how much the loop body itself eats, not including anything in
@@ -3531,14 +3533,23 @@ class EatsAtLeastPropagator : public AllStatic {
   }
 
   static void VisitAction(ActionNode* that) {
-    // POSITIVE_SUBMATCH_SUCCESS rewinds input, so we must not consider
-    // successor nodes for eats_at_least. SET_REGISTER_FOR_LOOP indicates a loop
-    // entry point, which means the loop body will run at least the minimum
-    // number of times before the continuation case can run. Otherwise the
-    // current node eats at least as much as its successor.
+    // - BEGIN_SUBMATCH and POSITIVE_SUBMATCH_SUCCESS wrap lookarounds.
+    // Lookarounds rewind input, so their eats_at_least value must not
+    // propagate to surroundings.
+    // TODO(jgruber): Instead of resetting EAL to 0 at lookaround boundaries,
+    // analysis should instead skip over the lookaround and look at whatever
+    // follows the lookaround. A simple solution would be to store a pointer to
+    // the associated POSITIVE_SUBMATCH_SUCCESS node in the BEGIN_SUBMATCH
+    // node, and use that during analysis.
+    // - SET_REGISTER_FOR_LOOP indicates a loop entry point, which means the
+    // loop body will run at least the minimum number of times before the
+    // continuation case can run. Otherwise the current node eats at least as
+    // much as its successor.
     switch (that->action_type()) {
+      case ActionNode::BEGIN_SUBMATCH:
       case ActionNode::POSITIVE_SUBMATCH_SUCCESS:
-        break;  // Was already initialized to zero.
+        DCHECK(that->eats_at_least_info()->IsZero());
+        break;
       case ActionNode::SET_REGISTER_FOR_LOOP:
         that->set_eats_at_least_info(
             that->on_success()->EatsAtLeastFromLoopEntry());
@@ -3560,7 +3571,10 @@ class EatsAtLeastPropagator : public AllStatic {
   }
 
   static void VisitLoopChoiceContinueNode(LoopChoiceNode* that) {
-    that->set_eats_at_least_info(*that->continue_node()->eats_at_least_info());
+    if (!that->read_backward()) {
+      that->set_eats_at_least_info(
+          *that->continue_node()->eats_at_least_info());
+    }
   }
 
   static void VisitLoopChoiceLoopNode(LoopChoiceNode* that) {}
diff --git a/chromium/v8/src/regexp/regexp-dotprinter.cc b/chromium/v8/src/regexp/regexp-dotprinter.cc
index 4412960b3dc..b708e8d7355 100644
--- a/chromium/v8/src/regexp/regexp-dotprinter.cc
+++ b/chromium/v8/src/regexp/regexp-dotprinter.cc
@@ -60,8 +60,7 @@ void DotPrinterImpl::PrintOnFailure(RegExpNode* from, RegExpNode* on_failure) {
 
 class AttributePrinter {
  public:
-  explicit AttributePrinter(std::ostream& os)  // NOLINT
-      : os_(os), first_(true) {}
+  explicit AttributePrinter(std::ostream& os) : os_(os), first_(true) {}
   void PrintSeparator() {
     if (first_) {
       first_ = false;
diff --git a/chromium/v8/src/regexp/regexp-macro-assembler.cc b/chromium/v8/src/regexp/regexp-macro-assembler.cc
index db45e21ca04..36ef75bc422 100644
--- a/chromium/v8/src/regexp/regexp-macro-assembler.cc
+++ b/chromium/v8/src/regexp/regexp-macro-assembler.cc
@@ -309,10 +309,9 @@ int NativeRegExpMacroAssembler::Execute(
   RegExp::CallOrigin call_origin = RegExp::CallOrigin::kFromRuntime;
 
   using RegexpMatcherSig = int(
-      Address input_string, int start_offset,  // NOLINT(readability/casting)
-      const byte* input_start, const byte* input_end, int* output,
-      int output_size, Address stack_base, int call_origin, Isolate* isolate,
-      Address regexp);
+      Address input_string, int start_offset, const byte* input_start,
+      const byte* input_end, int* output, int output_size, Address stack_base,
+      int call_origin, Isolate* isolate, Address regexp);
 
   auto fn = GeneratedCode<RegexpMatcherSig>::FromCode(code);
   int result =
diff --git a/chromium/v8/src/regexp/regexp-nodes.h b/chromium/v8/src/regexp/regexp-nodes.h
index 9b863ef2396..5a7df3df6bf 100644
--- a/chromium/v8/src/regexp/regexp-nodes.h
+++ b/chromium/v8/src/regexp/regexp-nodes.h
@@ -109,6 +109,11 @@ struct EatsAtLeastInfo final {
     }
   }
 
+  bool IsZero() const {
+    return eats_at_least_from_possibly_start == 0 &&
+           eats_at_least_from_not_start == 0;
+  }
+
   // Any successful match starting from the current node will consume at least
   // this many characters. This does not necessarily mean that there is a
   // possible match with exactly this many characters, but we generally try to
diff --git a/chromium/v8/src/regexp/x64/regexp-macro-assembler-x64.cc b/chromium/v8/src/regexp/x64/regexp-macro-assembler-x64.cc
index 79574ca9932..a02cccb96a4 100644
--- a/chromium/v8/src/regexp/x64/regexp-macro-assembler-x64.cc
+++ b/chromium/v8/src/regexp/x64/regexp-macro-assembler-x64.cc
@@ -356,8 +356,7 @@ void RegExpMacroAssemblerX64::CheckNotBackReferenceIgnoreCase(
     // Isolate.
     __ LoadAddress(arg_reg_4, ExternalReference::isolate_address(isolate()));
 
-    { // NOLINT: Can't find a way to open this scope without confusing the
-      // linter.
+    {
       AllowExternalCallThatCantCauseGC scope(&masm_);
       ExternalReference compare =
           unicode ? ExternalReference::re_case_insensitive_compare_unicode(
@@ -672,7 +671,7 @@ bool RegExpMacroAssemblerX64::CheckSpecialCharacterClass(uc16 type,
 void RegExpMacroAssemblerX64::Fail() {
   STATIC_ASSERT(FAILURE == 0);  // Return value for failure is zero.
   if (!global()) {
-    __ Set(rax, FAILURE);
+    __ Move(rax, FAILURE);
   }
   __ jmp(&exit_label_);
 }
@@ -750,7 +749,7 @@ Handle<HeapObject> RegExpMacroAssemblerX64::GetCode(Handle<String> source) {
   __ j(above_equal, &stack_ok);
   // Exit with OutOfMemory exception. There is not enough space on the stack
   // for our working registers.
-  __ Set(rax, EXCEPTION);
+  __ Move(rax, EXCEPTION);
   __ jmp(&return_rax);
 
   __ bind(&stack_limit_hit);
@@ -790,7 +789,7 @@ Handle<HeapObject> RegExpMacroAssemblerX64::GetCode(Handle<String> source) {
   // Load newline if index is at start, previous character otherwise.
   __ cmpl(Operand(rbp, kStartIndex), Immediate(0));
   __ j(not_equal, &load_char_start_regexp, Label::kNear);
-  __ Set(current_character(), '\n');
+  __ Move(current_character(), '\n');
   __ jmp(&start_regexp, Label::kNear);
 
   // Global regexp restarts matching here.
@@ -805,7 +804,7 @@ Handle<HeapObject> RegExpMacroAssemblerX64::GetCode(Handle<String> source) {
     // Fill in stack push order, to avoid accessing across an unwritten
     // page (a problem on Windows).
     if (num_saved_registers_ > 8) {
-      __ Set(rcx, kRegisterZero);
+      __ Move(rcx, kRegisterZero);
       Label init_loop;
       __ bind(&init_loop);
       __ movq(Operand(rbp, rcx, times_1, 0), rax);
@@ -1002,13 +1001,13 @@ Handle<HeapObject> RegExpMacroAssemblerX64::GetCode(Handle<String> source) {
     // If any of the code above needed to exit with an exception.
     __ bind(&exit_with_exception);
     // Exit with Result EXCEPTION(-1) to signal thrown exception.
-    __ Set(rax, EXCEPTION);
+    __ Move(rax, EXCEPTION);
     __ jmp(&return_rax);
   }
 
   if (fallback_label_.is_linked()) {
     __ bind(&fallback_label_);
-    __ Set(rax, FALLBACK_TO_EXPERIMENTAL);
+    __ Move(rax, FALLBACK_TO_EXPERIMENTAL);
     __ jmp(&return_rax);
   }
 
diff --git a/chromium/v8/src/roots/roots.cc b/chromium/v8/src/roots/roots.cc
index 3fdecfe0bf1..e79fdb31099 100644
--- a/chromium/v8/src/roots/roots.cc
+++ b/chromium/v8/src/roots/roots.cc
@@ -17,6 +17,10 @@ const char* RootsTable::root_names_[RootsTable::kEntriesCount] = {
 #undef ROOT_NAME
 };
 
+MapWord ReadOnlyRoots::one_pointer_filler_map_word() {
+  return MapWord::FromMap(one_pointer_filler_map());
+}
+
 void ReadOnlyRoots::Iterate(RootVisitor* visitor) {
   visitor->VisitRootPointers(Root::kReadOnlyRootList, nullptr,
                              FullObjectSlot(read_only_roots_),
diff --git a/chromium/v8/src/roots/roots.h b/chromium/v8/src/roots/roots.h
index 64758f5efaf..cfa0f897576 100644
--- a/chromium/v8/src/roots/roots.h
+++ b/chromium/v8/src/roots/roots.h
@@ -88,6 +88,7 @@ class Symbol;
   V(Map, fixed_double_array_map, FixedDoubleArrayMap)                          \
   V(Map, global_dictionary_map, GlobalDictionaryMap)                           \
   V(Map, many_closures_cell_map, ManyClosuresCellMap)                          \
+  V(Map, mega_dom_handler_map, MegaDomHandlerMap)                              \
   V(Map, module_info_map, ModuleInfoMap)                                       \
   V(Map, name_dictionary_map, NameDictionaryMap)                               \
   V(Map, no_closures_cell_map, NoClosuresCellMap)                              \
@@ -110,6 +111,9 @@ class Symbol;
   V(Map, source_text_module_map, SourceTextModuleMap)                          \
   V(Map, swiss_name_dictionary_map, SwissNameDictionaryMap)                    \
   V(Map, synthetic_module_map, SyntheticModuleMap)                             \
+  IF_WASM(V, Map, wasm_exported_function_data_map,                             \
+          WasmExportedFunctionDataMap)                                         \
+  IF_WASM(V, Map, wasm_js_function_data_map, WasmJSFunctionDataMap)            \
   IF_WASM(V, Map, wasm_type_info_map, WasmTypeInfoMap)                         \
   V(Map, weak_fixed_array_map, WeakFixedArrayMap)                              \
   V(Map, weak_array_list_map, WeakArrayListMap)                                \
@@ -210,6 +214,7 @@ class Symbol;
   /* Protectors */                                                             \
   V(PropertyCell, array_constructor_protector, ArrayConstructorProtector)      \
   V(PropertyCell, no_elements_protector, NoElementsProtector)                  \
+  V(PropertyCell, mega_dom_protector, MegaDOMProtector)                        \
   V(PropertyCell, is_concat_spreadable_protector, IsConcatSpreadableProtector) \
   V(PropertyCell, array_species_protector, ArraySpeciesProtector)              \
   V(PropertyCell, typed_array_species_protector, TypedArraySpeciesProtector)   \
@@ -536,6 +541,10 @@ class ReadOnlyRoots {
   V8_INLINE explicit ReadOnlyRoots(Isolate* isolate);
   V8_INLINE explicit ReadOnlyRoots(LocalIsolate* isolate);
 
+  // For `v8_enable_map_packing=true`, this will return a packed (also untagged)
+  // map-word instead of a tagged heap pointer.
+  MapWord one_pointer_filler_map_word();
+
 #define ROOT_ACCESSOR(Type, name, CamelName)     \
   V8_INLINE class Type name() const;             \
   V8_INLINE class Type unchecked_##name() const; \
diff --git a/chromium/v8/src/runtime/runtime-array.cc b/chromium/v8/src/runtime/runtime-array.cc
index 623064fd8aa..bdfb666ab7c 100644
--- a/chromium/v8/src/runtime/runtime-array.cc
+++ b/chromium/v8/src/runtime/runtime-array.cc
@@ -28,7 +28,14 @@ RUNTIME_FUNCTION(Runtime_TransitionElementsKind) {
   CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
   CONVERT_ARG_HANDLE_CHECKED(Map, to_map, 1);
   ElementsKind to_kind = to_map->elements_kind();
-  ElementsAccessor::ForKind(to_kind)->TransitionElementsKind(object, to_map);
+  if (ElementsAccessor::ForKind(to_kind)
+          ->TransitionElementsKind(object, to_map)
+          .IsNothing()) {
+    // TODO(victorgomes): EffectControlLinearizer::LowerTransitionElementsKind
+    // does not handle exceptions.
+    FATAL("Fatal JavaScript invalid array size");
+    UNREACHABLE();
+  }
   return *object;
 }
 
@@ -180,7 +187,11 @@ RUNTIME_FUNCTION(Runtime_GrowArrayElements) {
   uint32_t capacity = static_cast<uint32_t>(object->elements().length());
 
   if (index >= capacity) {
-    if (!object->GetElementsAccessor()->GrowCapacity(object, index)) {
+    bool has_grown;
+    MAYBE_ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+        isolate, has_grown,
+        object->GetElementsAccessor()->GrowCapacity(object, index));
+    if (!has_grown) {
       return Smi::zero();
     }
   }
diff --git a/chromium/v8/src/runtime/runtime-classes.cc b/chromium/v8/src/runtime/runtime-classes.cc
index 120f2441a79..8fb37cec32a 100644
--- a/chromium/v8/src/runtime/runtime-classes.cc
+++ b/chromium/v8/src/runtime/runtime-classes.cc
@@ -188,7 +188,6 @@ Object GetMethodWithSharedName(
 template <typename Dictionary>
 Handle<Dictionary> ShallowCopyDictionaryTemplate(
     Isolate* isolate, Handle<Dictionary> dictionary_template) {
-  Handle<Map> dictionary_map(dictionary_template->map(), isolate);
   Handle<Dictionary> dictionary =
       Dictionary::ShallowCopy(isolate, dictionary_template);
   // Clone all AccessorPairs in the dictionary.
@@ -375,7 +374,7 @@ bool AddDescriptorsByTemplate(
   }
 
   // Atomically commit the changes.
-  receiver->synchronized_set_map(*map);
+  receiver->set_map(*map, kReleaseStore);
   if (elements_dictionary->NumberOfElements() > 0) {
     receiver->set_elements(*elements_dictionary);
   }
@@ -469,7 +468,7 @@ bool AddDescriptorsByTemplate(
   }
 
   // Atomically commit the changes.
-  receiver->synchronized_set_map(*map);
+  receiver->set_map(*map, kReleaseStore);
   receiver->set_raw_properties_or_hash(*properties_dictionary);
   if (elements_dictionary->NumberOfElements() > 0) {
     receiver->set_elements(*elements_dictionary);
@@ -498,7 +497,7 @@ bool InitClassPrototype(Isolate* isolate,
   map = Map::CopyDropDescriptors(isolate, map);
   map->set_is_prototype_map(true);
   Map::SetPrototype(isolate, map, prototype_parent);
-  constructor->set_prototype_or_initial_map(*prototype);
+  constructor->set_prototype_or_initial_map(*prototype, kReleaseStore);
   map->SetConstructor(*constructor);
   Handle<FixedArray> computed_properties(
       class_boilerplate->instance_computed_properties(), isolate);
diff --git a/chromium/v8/src/runtime/runtime-compiler.cc b/chromium/v8/src/runtime/runtime-compiler.cc
index 090a9261c44..1586e35e254 100644
--- a/chromium/v8/src/runtime/runtime-compiler.cc
+++ b/chromium/v8/src/runtime/runtime-compiler.cc
@@ -29,14 +29,6 @@ namespace internal {
 
 namespace {
 
-// Returns false iff an exception was thrown.
-bool MaybeSpawnNativeContextIndependentCompilationJob(
-    Isolate* isolate, Handle<JSFunction> function, ConcurrencyMode mode) {
-  if (!FLAG_turbo_nci) return true;  // Nothing to do.
-  return Compiler::CompileOptimized(isolate, function, mode,
-                                    CodeKind::NATIVE_CONTEXT_INDEPENDENT);
-}
-
 Object CompileOptimized(Isolate* isolate, Handle<JSFunction> function,
                         ConcurrencyMode mode) {
   StackLimitCheck check(isolate);
@@ -50,34 +42,12 @@ Object CompileOptimized(Isolate* isolate, Handle<JSFunction> function,
     return ReadOnlyRoots(isolate).exception();
   }
 
-  // Possibly compile for NCI caching.
-  if (!MaybeSpawnNativeContextIndependentCompilationJob(isolate, function,
-                                                        mode)) {
-    return ReadOnlyRoots(isolate).exception();
-  }
-
   // As a post-condition of CompileOptimized, the function *must* be compiled,
   // i.e. the installed Code object must not be the CompileLazy builtin.
   DCHECK(function->is_compiled());
   return function->code();
 }
 
-void TryInstallNCICode(Isolate* isolate, Handle<JSFunction> function,
-                       Handle<SharedFunctionInfo> sfi,
-                       IsCompiledScope* is_compiled_scope) {
-  // This function should only be called if there's a possibility that cached
-  // code exists.
-  DCHECK(sfi->may_have_cached_code());
-  DCHECK_EQ(function->shared(), *sfi);
-
-  Handle<Code> code;
-  if (sfi->TryGetCachedCode(isolate).ToHandle(&code)) {
-    function->set_code(*code, kReleaseStore);
-    JSFunction::EnsureFeedbackVector(function, is_compiled_scope);
-    if (FLAG_trace_turbo_nci) CompilationCacheCode::TraceHit(sfi, code);
-  }
-}
-
 }  // namespace
 
 RUNTIME_FUNCTION(Runtime_CompileLazy) {
@@ -104,9 +74,6 @@ RUNTIME_FUNCTION(Runtime_CompileLazy) {
                          &is_compiled_scope)) {
     return ReadOnlyRoots(isolate).exception();
   }
-  if (sfi->may_have_cached_code()) {
-    TryInstallNCICode(isolate, function, sfi, &is_compiled_scope);
-  }
   DCHECK(function->is_compiled());
   return function->code();
 }
@@ -127,18 +94,6 @@ RUNTIME_FUNCTION(Runtime_InstallBaselineCode) {
   return baseline_code;
 }
 
-RUNTIME_FUNCTION(Runtime_TryInstallNCICode) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(1, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(JSFunction, function, 0);
-  DCHECK(function->is_compiled());
-  Handle<SharedFunctionInfo> sfi(function->shared(), isolate);
-  IsCompiledScope is_compiled_scope(*sfi, isolate);
-  TryInstallNCICode(isolate, function, sfi, &is_compiled_scope);
-  DCHECK(function->is_compiled());
-  return function->code();
-}
-
 RUNTIME_FUNCTION(Runtime_CompileOptimized_Concurrent) {
   HandleScope scope(isolate);
   DCHECK_EQ(1, args.length());
@@ -276,6 +231,14 @@ RUNTIME_FUNCTION(Runtime_ObserveNode) {
   return *obj;
 }
 
+RUNTIME_FUNCTION(Runtime_VerifyType) {
+  // %VerifyType has no effect in the interpreter.
+  HandleScope scope(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(Object, obj, 0);
+  return *obj;
+}
+
 static bool IsSuitableForOnStackReplacement(Isolate* isolate,
                                             Handle<JSFunction> function) {
   // Keep track of whether we've succeeded in optimizing.
@@ -356,16 +319,7 @@ RUNTIME_FUNCTION(Runtime_CompileForOnStackReplacement) {
       PrintF(scope.file(), " at OSR bytecode offset %d]\n", osr_offset.ToInt());
     }
     maybe_result =
-        Compiler::GetOptimizedCodeForOSR(function, osr_offset, frame);
-
-    // Possibly compile for NCI caching.
-    if (!MaybeSpawnNativeContextIndependentCompilationJob(
-            isolate, function,
-            isolate->concurrent_recompilation_enabled()
-                ? ConcurrencyMode::kConcurrent
-                : ConcurrencyMode::kNotConcurrent)) {
-      return Object();
-    }
+        Compiler::GetOptimizedCodeForOSR(isolate, function, osr_offset, frame);
   }
 
   // Check whether we ended up with usable optimized code.
diff --git a/chromium/v8/src/runtime/runtime-debug.cc b/chromium/v8/src/runtime/runtime-debug.cc
index 4ffcaf23978..90ae087d209 100644
--- a/chromium/v8/src/runtime/runtime-debug.cc
+++ b/chromium/v8/src/runtime/runtime-debug.cc
@@ -61,13 +61,6 @@ RUNTIME_FUNCTION_RETURN_PAIR(Runtime_DebugBreakOnBytecode) {
                             handle(it.frame()->function(), isolate));
   }
 
-  // If we are dropping frames, there is no need to get a return value or
-  // bytecode, since we will be restarting execution at a different frame.
-  if (isolate->debug()->will_restart()) {
-    return MakePair(ReadOnlyRoots(isolate).undefined_value(),
-                    Smi::FromInt(static_cast<uint8_t>(Bytecode::kIllegal)));
-  }
-
   // Return the handler from the original bytecode array.
   DCHECK(it.frame()->is_interpreted());
   InterpretedFrame* interpreted_frame =
@@ -157,11 +150,11 @@ RUNTIME_FUNCTION(Runtime_ScheduleBreak) {
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
+namespace {
+
 template <class IteratorType>
-static MaybeHandle<JSArray> GetIteratorInternalProperties(
-    Isolate* isolate, Handle<IteratorType> object) {
-  Factory* factory = isolate->factory();
-  Handle<IteratorType> iterator = Handle<IteratorType>::cast(object);
+static Handle<ArrayList> AddIteratorInternalProperties(
+    Isolate* isolate, Handle<ArrayList> result, Handle<IteratorType> iterator) {
   const char* kind = nullptr;
   switch (iterator->map().instance_type()) {
     case JS_MAP_KEY_ITERATOR_TYPE:
@@ -179,62 +172,60 @@ static MaybeHandle<JSArray> GetIteratorInternalProperties(
       UNREACHABLE();
   }
 
-  Handle<FixedArray> result = factory->NewFixedArray(2 * 3);
-  Handle<String> has_more =
-      factory->NewStringFromAsciiChecked("[[IteratorHasMore]]");
-  result->set(0, *has_more);
-  result->set(1, isolate->heap()->ToBoolean(iterator->HasMore()));
-
-  Handle<String> index =
-      factory->NewStringFromAsciiChecked("[[IteratorIndex]]");
-  result->set(2, *index);
-  result->set(3, iterator->index());
-
-  Handle<String> iterator_kind =
-      factory->NewStringFromAsciiChecked("[[IteratorKind]]");
-  result->set(4, *iterator_kind);
-  Handle<String> kind_str = factory->NewStringFromAsciiChecked(kind);
-  result->set(5, *kind_str);
-  return factory->NewJSArrayWithElements(result);
+  result = ArrayList::Add(
+      isolate, result,
+      isolate->factory()->NewStringFromAsciiChecked("[[IteratorHasMore]]"),
+      isolate->factory()->ToBoolean(iterator->HasMore()));
+  result = ArrayList::Add(
+      isolate, result,
+      isolate->factory()->NewStringFromAsciiChecked("[[IteratorIndex]]"),
+      handle(iterator->index(), isolate));
+  result = ArrayList::Add(
+      isolate, result,
+      isolate->factory()->NewStringFromAsciiChecked("[[IteratorKind]]"),
+      isolate->factory()->NewStringFromAsciiChecked(kind));
+  return result;
 }
 
+}  // namespace
 
 MaybeHandle<JSArray> Runtime::GetInternalProperties(Isolate* isolate,
                                                     Handle<Object> object) {
-  Factory* factory = isolate->factory();
+  auto result = ArrayList::New(isolate, 8 * 2);
+  if (object->IsJSObject()) {
+    PrototypeIterator iter(isolate, Handle<JSObject>::cast(object));
+    Handle<Object> prototype = PrototypeIterator::GetCurrent(iter);
+    if (!prototype->IsNull(isolate)) {
+      result = ArrayList::Add(
+          isolate, result,
+          isolate->factory()->NewStringFromStaticChars("[[Prototype]]"),
+          prototype);
+    }
+  }
   if (object->IsJSBoundFunction()) {
     Handle<JSBoundFunction> function = Handle<JSBoundFunction>::cast(object);
 
-    Handle<FixedArray> result = factory->NewFixedArray(2 * 3);
-    Handle<String> target =
-        factory->NewStringFromAsciiChecked("[[TargetFunction]]");
-    result->set(0, *target);
-    result->set(1, function->bound_target_function());
-
-    Handle<String> bound_this =
-        factory->NewStringFromAsciiChecked("[[BoundThis]]");
-    result->set(2, *bound_this);
-    result->set(3, function->bound_this());
-
-    Handle<String> bound_args =
-        factory->NewStringFromAsciiChecked("[[BoundArgs]]");
-    result->set(4, *bound_args);
-    Handle<FixedArray> bound_arguments =
-        factory->CopyFixedArray(handle(function->bound_arguments(), isolate));
-    Handle<JSArray> arguments_array =
-        factory->NewJSArrayWithElements(bound_arguments);
-    result->set(5, *arguments_array);
-    return factory->NewJSArrayWithElements(result);
-  }
-  if (object->IsJSMapIterator()) {
+    result = ArrayList::Add(
+        isolate, result,
+        isolate->factory()->NewStringFromAsciiChecked("[[TargetFunction]]"),
+        handle(function->bound_target_function(), isolate));
+    result = ArrayList::Add(
+        isolate, result,
+        isolate->factory()->NewStringFromAsciiChecked("[[BoundThis]]"),
+        handle(function->bound_this(), isolate));
+    result = ArrayList::Add(
+        isolate, result,
+        isolate->factory()->NewStringFromAsciiChecked("[[BoundArgs]]"),
+        isolate->factory()->NewJSArrayWithElements(
+            isolate->factory()->CopyFixedArray(
+                handle(function->bound_arguments(), isolate))));
+  } else if (object->IsJSMapIterator()) {
     Handle<JSMapIterator> iterator = Handle<JSMapIterator>::cast(object);
-    return GetIteratorInternalProperties(isolate, iterator);
-  }
-  if (object->IsJSSetIterator()) {
+    result = AddIteratorInternalProperties(isolate, result, iterator);
+  } else if (object->IsJSSetIterator()) {
     Handle<JSSetIterator> iterator = Handle<JSSetIterator>::cast(object);
-    return GetIteratorInternalProperties(isolate, iterator);
-  }
-  if (object->IsJSGeneratorObject()) {
+    result = AddIteratorInternalProperties(isolate, result, iterator);
+  } else if (object->IsJSGeneratorObject()) {
     Handle<JSGeneratorObject> generator =
         Handle<JSGeneratorObject>::cast(object);
 
@@ -247,163 +238,131 @@ MaybeHandle<JSArray> Runtime::GetInternalProperties(Isolate* isolate,
       DCHECK(generator->is_suspended());
     }
 
-    Handle<FixedArray> result = factory->NewFixedArray(2 * 3);
-    Handle<String> generator_status =
-        factory->NewStringFromAsciiChecked("[[GeneratorState]]");
-    result->set(0, *generator_status);
-    Handle<String> status_str = factory->NewStringFromAsciiChecked(status);
-    result->set(1, *status_str);
-
-    Handle<String> function =
-        factory->NewStringFromAsciiChecked("[[GeneratorFunction]]");
-    result->set(2, *function);
-    result->set(3, generator->function());
-
-    Handle<String> receiver =
-        factory->NewStringFromAsciiChecked("[[GeneratorReceiver]]");
-    result->set(4, *receiver);
-    result->set(5, generator->receiver());
-    return factory->NewJSArrayWithElements(result);
-  }
-  if (object->IsJSPromise()) {
+    result = ArrayList::Add(
+        isolate, result,
+        isolate->factory()->NewStringFromAsciiChecked("[[GeneratorState]]"),
+        isolate->factory()->NewStringFromAsciiChecked(status));
+    result = ArrayList::Add(
+        isolate, result,
+        isolate->factory()->NewStringFromAsciiChecked("[[GeneratorFunction]]"),
+        handle(generator->function(), isolate));
+    result = ArrayList::Add(
+        isolate, result,
+        isolate->factory()->NewStringFromAsciiChecked("[[GeneratorReceiver]]"),
+        handle(generator->receiver(), isolate));
+  } else if (object->IsJSPromise()) {
     Handle<JSPromise> promise = Handle<JSPromise>::cast(object);
-    const char* status = JSPromise::Status(promise->status());
-    Handle<FixedArray> result = factory->NewFixedArray(2 * 2);
-    Handle<String> promise_status =
-        factory->NewStringFromAsciiChecked("[[PromiseState]]");
-    result->set(0, *promise_status);
-    Handle<String> status_str = factory->NewStringFromAsciiChecked(status);
-    result->set(1, *status_str);
-
-    Handle<Object> value_obj(promise->status() == Promise::kPending
-                                 ? ReadOnlyRoots(isolate).undefined_value()
-                                 : promise->result(),
-                             isolate);
-    Handle<String> promise_value =
-        factory->NewStringFromAsciiChecked("[[PromiseResult]]");
-    result->set(2, *promise_value);
-    result->set(3, *value_obj);
-    return factory->NewJSArrayWithElements(result);
-  }
-  if (object->IsJSProxy()) {
-    Handle<JSProxy> js_proxy = Handle<JSProxy>::cast(object);
-    Handle<FixedArray> result = factory->NewFixedArray(3 * 2);
 
-    Handle<String> handler_str =
-        factory->NewStringFromAsciiChecked("[[Handler]]");
-    result->set(0, *handler_str);
-    result->set(1, js_proxy->handler());
-
-    Handle<String> target_str =
-        factory->NewStringFromAsciiChecked("[[Target]]");
-    result->set(2, *target_str);
-    result->set(3, js_proxy->target());
+    result = ArrayList::Add(
+        isolate, result,
+        isolate->factory()->NewStringFromAsciiChecked("[[PromiseState]]"),
+        isolate->factory()->NewStringFromAsciiChecked(
+            JSPromise::Status(promise->status())));
+    result = ArrayList::Add(
+        isolate, result,
+        isolate->factory()->NewStringFromAsciiChecked("[[PromiseResult]]"),
+        promise->status() == Promise::kPending
+            ? isolate->factory()->undefined_value()
+            : handle(promise->result(), isolate));
+  } else if (object->IsJSProxy()) {
+    Handle<JSProxy> js_proxy = Handle<JSProxy>::cast(object);
 
-    Handle<String> is_revoked_str =
-        factory->NewStringFromAsciiChecked("[[IsRevoked]]");
-    result->set(4, *is_revoked_str);
-    result->set(5, isolate->heap()->ToBoolean(js_proxy->IsRevoked()));
-    return factory->NewJSArrayWithElements(result);
-  }
-  if (object->IsJSPrimitiveWrapper()) {
+    result = ArrayList::Add(
+        isolate, result,
+        isolate->factory()->NewStringFromAsciiChecked("[[Handler]]"),
+        handle(js_proxy->handler(), isolate));
+    result = ArrayList::Add(
+        isolate, result,
+        isolate->factory()->NewStringFromAsciiChecked("[[Target]]"),
+        handle(js_proxy->target(), isolate));
+    result = ArrayList::Add(
+        isolate, result,
+        isolate->factory()->NewStringFromAsciiChecked("[[IsRevoked]]"),
+        isolate->factory()->ToBoolean(js_proxy->IsRevoked()));
+  } else if (object->IsJSPrimitiveWrapper()) {
     Handle<JSPrimitiveWrapper> js_value =
         Handle<JSPrimitiveWrapper>::cast(object);
 
-    Handle<FixedArray> result = factory->NewFixedArray(2);
-    Handle<String> primitive_value =
-        factory->NewStringFromAsciiChecked("[[PrimitiveValue]]");
-    result->set(0, *primitive_value);
-    result->set(1, js_value->value());
-    return factory->NewJSArrayWithElements(result);
-  }
-  if (object->IsJSArrayBuffer()) {
+    result = ArrayList::Add(
+        isolate, result,
+        isolate->factory()->NewStringFromAsciiChecked("[[PrimitiveValue]]"),
+        handle(js_value->value(), isolate));
+  } else if (object->IsJSArrayBuffer()) {
     Handle<JSArrayBuffer> js_array_buffer = Handle<JSArrayBuffer>::cast(object);
     if (js_array_buffer->was_detached()) {
       // Mark a detached JSArrayBuffer and such and don't even try to
       // create views for it, since the TypedArray constructors will
       // throw a TypeError when the underlying buffer is detached.
-      Handle<FixedArray> result = factory->NewFixedArray(1 * 2);
-      Handle<String> is_detached_str =
-          factory->NewStringFromAsciiChecked("[[IsDetached]]");
-      result->set(0, *is_detached_str);
-      result->set(1, isolate->heap()->ToBoolean(true));
-      return factory->NewJSArrayWithElements(result, PACKED_ELEMENTS);
-    }
-    const size_t byte_length = js_array_buffer->byte_length();
-    static const ExternalArrayType kTypes[] = {
-        kExternalInt8Array,
-        kExternalUint8Array,
-        kExternalInt16Array,
-        kExternalInt32Array,
-    };
-    Handle<FixedArray> result =
-        factory->NewFixedArray((3 + arraysize(kTypes)) * 2);
-    int index = 0;
-    for (auto type : kTypes) {
-      switch (type) {
-#define TYPED_ARRAY_CASE(Type, type, TYPE, ctype)                            \
-  case kExternal##Type##Array: {                                             \
-    if ((byte_length % sizeof(ctype)) != 0) continue;                        \
-    Handle<String> typed_array_str =                                         \
-        factory->NewStringFromStaticChars("[[" #Type "Array]]");             \
-    Handle<JSTypedArray> js_typed_array =                                    \
-        factory->NewJSTypedArray(kExternal##Type##Array, js_array_buffer, 0, \
-                                 byte_length / sizeof(ctype));               \
-    result->set(index++, *typed_array_str);                                  \
-    result->set(index++, *js_typed_array);                                   \
-    break;                                                                   \
-  }
-        TYPED_ARRAYS(TYPED_ARRAY_CASE)
+      result = ArrayList::Add(
+          isolate, result,
+          isolate->factory()->NewStringFromAsciiChecked("[[IsDetached]]"),
+          isolate->factory()->true_value());
+    } else {
+      const size_t byte_length = js_array_buffer->byte_length();
+      static const ExternalArrayType kTypes[] = {
+          kExternalInt8Array,
+          kExternalUint8Array,
+          kExternalInt16Array,
+          kExternalInt32Array,
+      };
+      for (auto type : kTypes) {
+        switch (type) {
+#define TYPED_ARRAY_CASE(Type, type, TYPE, ctype)                           \
+  case kExternal##Type##Array: {                                            \
+    if ((byte_length % sizeof(ctype)) != 0) continue;                       \
+    result = ArrayList::Add(                                                \
+        isolate, result,                                                    \
+        isolate->factory()->NewStringFromStaticChars("[[" #Type "Array]]"), \
+        isolate->factory()->NewJSTypedArray(kExternal##Type##Array,         \
+                                            js_array_buffer, 0,             \
+                                            byte_length / sizeof(ctype)));  \
+    break;                                                                  \
+  }
+          TYPED_ARRAYS(TYPED_ARRAY_CASE)
 #undef TYPED_ARRAY_CASE
         default:
           UNREACHABLE();
+        }
+      }
+      result =
+          ArrayList::Add(isolate, result,
+                         isolate->factory()->NewStringFromAsciiChecked(
+                             "[[ArrayBufferByteLength]]"),
+                         isolate->factory()->NewNumberFromSize(byte_length));
+
+      // Use the backing store pointer as a unique ID
+      EmbeddedVector<char, 32> buffer_data_vec;
+      int len =
+          SNPrintF(buffer_data_vec, V8PRIxPTR_FMT,
+                   reinterpret_cast<Address>(js_array_buffer->backing_store()));
+      result = ArrayList::Add(
+          isolate, result,
+          isolate->factory()->NewStringFromAsciiChecked("[[ArrayBufferData]]"),
+          isolate->factory()->InternalizeUtf8String(
+              buffer_data_vec.SubVector(0, len)));
+
+      Handle<Symbol> memory_symbol =
+          isolate->factory()->array_buffer_wasm_memory_symbol();
+      Handle<Object> memory_object =
+          JSObject::GetDataProperty(js_array_buffer, memory_symbol);
+      if (!memory_object->IsUndefined(isolate)) {
+        result = ArrayList::Add(isolate, result,
+                                isolate->factory()->NewStringFromAsciiChecked(
+                                    "[[WebAssemblyMemory]]"),
+                                memory_object);
       }
     }
-    Handle<String> byte_length_str =
-        factory->NewStringFromAsciiChecked("[[ArrayBufferByteLength]]");
-    Handle<Object> byte_length_obj = factory->NewNumberFromSize(byte_length);
-    result->set(index++, *byte_length_str);
-    result->set(index++, *byte_length_obj);
-
-    Handle<String> buffer_data_str =
-        factory->NewStringFromAsciiChecked("[[ArrayBufferData]]");
-    // Use the backing store pointer as a unique ID
-    EmbeddedVector<char, 32> buffer_data_vec;
-    int len =
-        SNPrintF(buffer_data_vec, V8PRIxPTR_FMT,
-                 reinterpret_cast<Address>(js_array_buffer->backing_store()));
-    Handle<String> buffer_data_obj =
-        factory->InternalizeUtf8String(buffer_data_vec.SubVector(0, len));
-    result->set(index++, *buffer_data_str);
-    result->set(index++, *buffer_data_obj);
-
 #if V8_ENABLE_WEBASSEMBLY
-    Handle<Symbol> memory_symbol = factory->array_buffer_wasm_memory_symbol();
-    Handle<Object> memory_object =
-        JSObject::GetDataProperty(js_array_buffer, memory_symbol);
-    if (!memory_object->IsUndefined(isolate)) {
-      Handle<String> buffer_memory_str =
-          factory->NewStringFromAsciiChecked("[[WebAssemblyMemory]]");
-      Handle<WasmMemoryObject> buffer_memory_obj =
-          Handle<WasmMemoryObject>::cast(memory_object);
-      result->set(index++, *buffer_memory_str);
-      result->set(index++, *buffer_memory_obj);
-    }
+  } else if (object->IsWasmInstanceObject()) {
+    result = AddWasmInstanceObjectInternalProperties(
+        isolate, result, Handle<WasmInstanceObject>::cast(object));
+  } else if (object->IsWasmModuleObject()) {
+    result = AddWasmModuleObjectInternalProperties(
+        isolate, result, Handle<WasmModuleObject>::cast(object));
 #endif  // V8_ENABLE_WEBASSEMBLY
-
-    return factory->NewJSArrayWithElements(result, PACKED_ELEMENTS, index);
   }
-#if V8_ENABLE_WEBASSEMBLY
-  if (object->IsWasmInstanceObject()) {
-    return GetWasmInstanceObjectInternalProperties(
-        Handle<WasmInstanceObject>::cast(object));
-  }
-  if (object->IsWasmModuleObject()) {
-    return GetWasmModuleObjectInternalProperties(
-        Handle<WasmModuleObject>::cast(object));
-  }
-#endif  // V8_ENABLE_WEBASSEMBLY
-  return factory->NewJSArray(0);
+  return isolate->factory()->NewJSArrayWithElements(
+      ArrayList::Elements(isolate, result), PACKED_ELEMENTS);
 }
 
 RUNTIME_FUNCTION(Runtime_GetGeneratorScopeCount) {
@@ -718,7 +677,8 @@ RUNTIME_FUNCTION(Runtime_DebugOnFunctionCall) {
   CONVERT_ARG_HANDLE_CHECKED(Object, receiver, 1);
   if (isolate->debug()->needs_check_on_function_call()) {
     // Ensure that the callee will perform debug check on function call too.
-    Deoptimizer::DeoptimizeFunction(*fun);
+    Handle<SharedFunctionInfo> shared(fun->shared(), isolate);
+    isolate->debug()->DeoptimizeFunction(shared);
     if (isolate->debug()->last_step_action() >= StepIn ||
         isolate->debug()->break_on_next_function_call()) {
       DCHECK_EQ(isolate->debug_execution_mode(), DebugInfo::kBreakpoints);
@@ -902,22 +862,9 @@ RUNTIME_FUNCTION(Runtime_LiveEditPatchScript) {
     case v8::debug::LiveEditResult::BLOCKED_BY_RUNNING_GENERATOR:
       return isolate->Throw(*isolate->factory()->NewStringFromAsciiChecked(
           "LiveEdit failed: BLOCKED_BY_RUNNING_GENERATOR"));
-    case v8::debug::LiveEditResult::BLOCKED_BY_FUNCTION_ABOVE_BREAK_FRAME:
-      return isolate->Throw(*isolate->factory()->NewStringFromAsciiChecked(
-          "LiveEdit failed: BLOCKED_BY_FUNCTION_ABOVE_BREAK_FRAME"));
-    case v8::debug::LiveEditResult::
-        BLOCKED_BY_FUNCTION_BELOW_NON_DROPPABLE_FRAME:
-      return isolate->Throw(*isolate->factory()->NewStringFromAsciiChecked(
-          "LiveEdit failed: BLOCKED_BY_FUNCTION_BELOW_NON_DROPPABLE_FRAME"));
     case v8::debug::LiveEditResult::BLOCKED_BY_ACTIVE_FUNCTION:
       return isolate->Throw(*isolate->factory()->NewStringFromAsciiChecked(
           "LiveEdit failed: BLOCKED_BY_ACTIVE_FUNCTION"));
-    case v8::debug::LiveEditResult::BLOCKED_BY_NEW_TARGET_IN_RESTART_FRAME:
-      return isolate->Throw(*isolate->factory()->NewStringFromAsciiChecked(
-          "LiveEdit failed: BLOCKED_BY_NEW_TARGET_IN_RESTART_FRAME"));
-    case v8::debug::LiveEditResult::FRAME_RESTART_IS_NOT_SUPPORTED:
-      return isolate->Throw(*isolate->factory()->NewStringFromAsciiChecked(
-          "LiveEdit failed: FRAME_RESTART_IS_NOT_SUPPORTED"));
     case v8::debug::LiveEditResult::OK:
       return ReadOnlyRoots(isolate).undefined_value();
   }
@@ -931,7 +878,7 @@ RUNTIME_FUNCTION(Runtime_ProfileCreateSnapshotDataBlob) {
   // Used only by the test/memory/Memory.json benchmark. This creates a snapshot
   // blob and outputs various statistics around it.
 
-  DCHECK(FLAG_profile_deserialization);
+  DCHECK(FLAG_profile_deserialization && FLAG_serialization_statistics);
 
   DisableEmbeddedBlobRefcounting();
 
diff --git a/chromium/v8/src/runtime/runtime-internal.cc b/chromium/v8/src/runtime/runtime-internal.cc
index 245d1fd77e1..6d569c2be2e 100644
--- a/chromium/v8/src/runtime/runtime-internal.cc
+++ b/chromium/v8/src/runtime/runtime-internal.cc
@@ -7,6 +7,7 @@
 #include "src/api/api.h"
 #include "src/ast/ast-traversal-visitor.h"
 #include "src/ast/prettyprinter.h"
+#include "src/baseline/baseline-osr-inl.h"
 #include "src/baseline/baseline.h"
 #include "src/builtins/builtins.h"
 #include "src/common/message-template.h"
@@ -139,6 +140,7 @@ const char* ElementsKindToType(ElementsKind fixed_elements_kind) {
     return #Type "Array";
 
     TYPED_ARRAYS(ELEMENTS_KIND_CASE)
+    RAB_GSAB_TYPED_ARRAYS_WITH_TYPED_ARRAY_TYPE(ELEMENTS_KIND_CASE)
 #undef ELEMENTS_KIND_CASE
 
     default:
@@ -342,23 +344,13 @@ RUNTIME_FUNCTION(Runtime_BytecodeBudgetInterruptFromBytecode) {
     // a non zero invocation count so we can inline functions.
     function->feedback_vector().set_invocation_count(1);
     if (FLAG_sparkplug) {
-      if (Compiler::CompileBaseline(isolate, function,
-                                    Compiler::CLEAR_EXCEPTION,
-                                    &is_compiled_scope)) {
-        if (FLAG_use_osr) {
-          JavaScriptFrameIterator it(isolate);
-          DCHECK(it.frame()->is_unoptimized());
-          UnoptimizedFrame* frame = UnoptimizedFrame::cast(it.frame());
-          if (FLAG_trace_osr) {
-            CodeTracer::Scope scope(isolate->GetCodeTracer());
-            PrintF(
-                scope.file(),
-                "[OSR - Entry at OSR bytecode offset %d into baseline code]\n",
-                frame->GetBytecodeOffset());
-          }
-          frame->GetBytecodeArray().set_osr_loop_nesting_level(
-              AbstractCode::kMaxLoopNestingMarker);
-        }
+      if (V8_LIKELY(FLAG_use_osr)) {
+        JavaScriptFrameIterator it(isolate);
+        DCHECK(it.frame()->is_unoptimized());
+        UnoptimizedFrame* frame = UnoptimizedFrame::cast(it.frame());
+        OSRInterpreterFrameToBaseline(isolate, function, frame);
+      } else {
+        OSRInterpreterFrameToBaseline(isolate, function, nullptr);
       }
     }
     return ReadOnlyRoots(isolate).undefined_value();
@@ -528,6 +520,7 @@ RUNTIME_FUNCTION(Runtime_IncrementUseCounter) {
 RUNTIME_FUNCTION(Runtime_GetAndResetRuntimeCallStats) {
   HandleScope scope(isolate);
   DCHECK_LE(args.length(), 2);
+#ifdef V8_RUNTIME_CALL_STATS
   // Append any worker thread runtime call stats to the main table before
   // printing.
   isolate->counters()->worker_thread_runtime_call_stats()->AddToMainTable(
@@ -570,6 +563,7 @@ RUNTIME_FUNCTION(Runtime_GetAndResetRuntimeCallStats) {
   } else {
     std::fflush(f);
   }
+#endif  // V8_RUNTIME_CALL_STATS
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
diff --git a/chromium/v8/src/runtime/runtime-literals.cc b/chromium/v8/src/runtime/runtime-literals.cc
index 5ee7bcd4c53..c4285f2403b 100644
--- a/chromium/v8/src/runtime/runtime-literals.cc
+++ b/chromium/v8/src/runtime/runtime-literals.cc
@@ -218,6 +218,7 @@ MaybeHandle<JSObject> JSObjectWalkVisitor<ContextObject>::StructureWalk(
 #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype) case TYPE##_ELEMENTS:
 
       TYPED_ARRAYS(TYPED_ARRAY_CASE)
+      RAB_GSAB_TYPED_ARRAYS(TYPED_ARRAY_CASE)
 #undef TYPED_ARRAY_CASE
       // Typed elements cannot be created using an object literal.
       UNREACHABLE();
@@ -291,7 +292,7 @@ class AllocationSiteCreationContext : public AllocationSiteContext {
   }
   void ExitScope(Handle<AllocationSite> scope_site, Handle<JSObject> object) {
     if (object.is_null()) return;
-    scope_site->set_boilerplate(*object);
+    scope_site->set_boilerplate(*object, kReleaseStore);
     if (FLAG_trace_creation_allocation_sites) {
       bool top_level =
           !scope_site.is_null() && top().is_identical_to(scope_site);
diff --git a/chromium/v8/src/runtime/runtime-object.cc b/chromium/v8/src/runtime/runtime-object.cc
index a98ad2e6dc4..13493125da1 100644
--- a/chromium/v8/src/runtime/runtime-object.cc
+++ b/chromium/v8/src/runtime/runtime-object.cc
@@ -16,8 +16,10 @@
 #include "src/logging/counters.h"
 #include "src/objects/hash-table-inl.h"
 #include "src/objects/js-array-inl.h"
+#include "src/objects/map-updater.h"
 #include "src/objects/property-descriptor-object.h"
 #include "src/objects/property-descriptor.h"
+#include "src/objects/property-details.h"
 #include "src/objects/swiss-name-dictionary-inl.h"
 #include "src/runtime/runtime-utils.h"
 #include "src/runtime/runtime.h"
@@ -25,23 +27,22 @@
 namespace v8 {
 namespace internal {
 
-MaybeHandle<Object> Runtime::GetObjectProperty(Isolate* isolate,
-                                               Handle<Object> holder,
-                                               Handle<Object> key,
-                                               Handle<Object> receiver,
-                                               bool* is_found) {
+MaybeHandle<Object> Runtime::GetObjectProperty(
+    Isolate* isolate, Handle<Object> lookup_start_object, Handle<Object> key,
+    Handle<Object> receiver, bool* is_found) {
   if (receiver.is_null()) {
-    receiver = holder;
+    receiver = lookup_start_object;
   }
-  if (holder->IsNullOrUndefined(isolate)) {
-    ErrorUtils::ThrowLoadFromNullOrUndefined(isolate, holder, key);
+  if (lookup_start_object->IsNullOrUndefined(isolate)) {
+    ErrorUtils::ThrowLoadFromNullOrUndefined(isolate, lookup_start_object, key);
     return MaybeHandle<Object>();
   }
 
   bool success = false;
   LookupIterator::Key lookup_key(isolate, key, &success);
   if (!success) return MaybeHandle<Object>();
-  LookupIterator it = LookupIterator(isolate, receiver, lookup_key, holder);
+  LookupIterator it =
+      LookupIterator(isolate, receiver, lookup_key, lookup_start_object);
 
   MaybeHandle<Object> result = Object::GetProperty(&it);
   if (is_found) *is_found = it.IsFound();
@@ -58,12 +59,12 @@ MaybeHandle<Object> Runtime::GetObjectProperty(Isolate* isolate,
                                       : name_string;
       THROW_NEW_ERROR(isolate,
                       NewTypeError(MessageTemplate::kInvalidPrivateBrand,
-                                   class_name, holder),
+                                   class_name, lookup_start_object),
                       Object);
     }
     THROW_NEW_ERROR(isolate,
                     NewTypeError(MessageTemplate::kInvalidPrivateMemberRead,
-                                 name_string, holder),
+                                 name_string, lookup_start_object),
                     Object);
   }
   return result;
@@ -95,6 +96,28 @@ MaybeHandle<Object> Runtime::HasProperty(Isolate* isolate,
 
 namespace {
 
+// This function sets the sentinel value in a deleted field. Thes sentinel has
+// to look like a proper standalone object because the slack tracking may
+// complete at any time. For this reason we use the filler map word.
+// If V8_MAP_PACKING is enabled, then the filler map word is a packed filler
+// map. Otherwise, the filler map word is the same as the filler map.
+inline void ClearField(Isolate* isolate, JSObject object, FieldIndex index) {
+  if (index.is_inobject()) {
+    MapWord filler_map_word =
+        ReadOnlyRoots(isolate).one_pointer_filler_map_word();
+#ifndef V8_MAP_PACKING
+    DCHECK_EQ(filler_map_word.ToMap(),
+              ReadOnlyRoots(isolate).one_pointer_filler_map());
+#endif
+    int offset = index.offset();
+    TaggedField<MapWord>::Release_Store(object, offset, filler_map_word);
+  } else {
+    object.property_array().set(
+        index.outobject_array_index(),
+        ReadOnlyRoots(isolate).one_pointer_filler_map());
+  }
+}
+
 void GeneralizeAllTransitionsToFieldAsMutable(Isolate* isolate, Handle<Map> map,
                                               Handle<Name> name) {
   InternalIndex descriptor(map->NumberOfOwnDescriptors());
@@ -131,9 +154,9 @@ void GeneralizeAllTransitionsToFieldAsMutable(Isolate* isolate, Handle<Map> map,
     Handle<FieldType> field_type(
         target->instance_descriptors(isolate).GetFieldType(descriptor),
         isolate);
-    Map::GeneralizeField(isolate, target, descriptor,
-                         PropertyConstness::kMutable, details.representation(),
-                         field_type);
+    MapUpdater::GeneralizeField(isolate, target, descriptor,
+                                PropertyConstness::kMutable,
+                                details.representation(), field_type);
     DCHECK_EQ(PropertyConstness::kMutable, target->instance_descriptors(isolate)
                                                .GetDetails(descriptor)
                                                .constness());
@@ -191,8 +214,7 @@ bool DeleteObjectPropertyFast(Isolate* isolate, Handle<JSReceiver> receiver,
       // Clear out the properties backing store.
       receiver->SetProperties(ReadOnlyRoots(isolate).empty_fixed_array());
     } else {
-      Object filler = ReadOnlyRoots(isolate).one_pointer_filler_map();
-      JSObject::cast(*receiver).FastPropertyAtPut(index, filler);
+      ClearField(isolate, JSObject::cast(*receiver), index);
       // We must clear any recorded slot for the deleted property, because
       // subsequent object modifications might put a raw double there.
       // Slot clearing is the reason why this entire function cannot currently
@@ -203,8 +225,10 @@ bool DeleteObjectPropertyFast(Isolate* isolate, Handle<JSReceiver> receiver,
         // have recorded slots in free space.
         isolate->heap()->ClearRecordedSlot(*receiver,
                                            receiver->RawField(index.offset()));
-        MemoryChunk* chunk = MemoryChunk::FromHeapObject(*receiver);
-        chunk->InvalidateRecordedSlots(*receiver);
+        if (!FLAG_enable_third_party_heap) {
+          MemoryChunk* chunk = MemoryChunk::FromHeapObject(*receiver);
+          chunk->InvalidateRecordedSlots(*receiver);
+        }
       }
     }
   }
@@ -214,7 +238,7 @@ bool DeleteObjectPropertyFast(Isolate* isolate, Handle<JSReceiver> receiver,
   // the "deoptimize dependent code" mechanism.
   receiver_map->NotifyLeafMapLayoutChange(isolate);
   // Finally, perform the map rollback.
-  receiver->synchronized_set_map(*parent_map);
+  receiver->set_map(*parent_map, kReleaseStore);
 #if VERIFY_HEAP
   receiver->HeapObjectVerify(isolate);
   receiver->property_array().PropertyArrayVerify(isolate);
@@ -682,15 +706,15 @@ RUNTIME_FUNCTION(Runtime_JSReceiverSetPrototypeOfDontThrow) {
 RUNTIME_FUNCTION(Runtime_GetProperty) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 3 || args.length() == 2);
-  CONVERT_ARG_HANDLE_CHECKED(Object, holder_obj, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, lookup_start_obj, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, key_obj, 1);
-  Handle<Object> receiver_obj = holder_obj;
+  Handle<Object> receiver_obj = lookup_start_obj;
   if (args.length() == 3) {
     CHECK(args[2].IsObject());
     receiver_obj = args.at<Object>(2);
   }
 
-  // Fast cases for getting named properties of the holder JSObject
+  // Fast cases for getting named properties of the lookup_start_obj JSObject
   // itself.
   //
   // The global proxy objects has to be excluded since LookupOwn on
@@ -708,18 +732,19 @@ RUNTIME_FUNCTION(Runtime_GetProperty) {
   if (key_obj->IsString() && String::cast(*key_obj).AsArrayIndex(&index)) {
     key_obj = isolate->factory()->NewNumberFromUint(index);
   }
-  if (holder_obj->IsJSObject()) {
-    if (!holder_obj->IsJSGlobalProxy() && !holder_obj->IsAccessCheckNeeded() &&
-        key_obj->IsName()) {
-      Handle<JSObject> holder = Handle<JSObject>::cast(holder_obj);
+  if (lookup_start_obj->IsJSObject()) {
+    Handle<JSObject> lookup_start_object =
+        Handle<JSObject>::cast(lookup_start_obj);
+    if (!lookup_start_object->IsJSGlobalProxy() &&
+        !lookup_start_object->IsAccessCheckNeeded() && key_obj->IsName()) {
       Handle<Name> key = Handle<Name>::cast(key_obj);
       key_obj = key = isolate->factory()->InternalizeName(key);
 
       DisallowGarbageCollection no_gc;
-      if (holder->IsJSGlobalObject()) {
+      if (lookup_start_object->IsJSGlobalObject()) {
         // Attempt dictionary lookup.
-        GlobalDictionary dictionary =
-            JSGlobalObject::cast(*holder).global_dictionary(kAcquireLoad);
+        GlobalDictionary dictionary = JSGlobalObject::cast(*lookup_start_object)
+                                          .global_dictionary(kAcquireLoad);
         InternalIndex entry = dictionary.FindEntry(isolate, key);
         if (entry.is_found()) {
           PropertyCell cell = dictionary.CellAt(entry);
@@ -729,17 +754,19 @@ RUNTIME_FUNCTION(Runtime_GetProperty) {
             // If value is the hole (meaning, absent) do the general lookup.
           }
         }
-      } else if (!holder->HasFastProperties()) {
+      } else if (!lookup_start_object->HasFastProperties()) {
         // Attempt dictionary lookup.
         if (V8_ENABLE_SWISS_NAME_DICTIONARY_BOOL) {
-          SwissNameDictionary dictionary = holder->property_dictionary_swiss();
+          SwissNameDictionary dictionary =
+              lookup_start_object->property_dictionary_swiss();
           InternalIndex entry = dictionary.FindEntry(isolate, *key);
           if (entry.is_found() &&
               (dictionary.DetailsAt(entry).kind() == kData)) {
             return dictionary.ValueAt(entry);
           }
         } else {
-          NameDictionary dictionary = holder->property_dictionary();
+          NameDictionary dictionary =
+              lookup_start_object->property_dictionary();
           InternalIndex entry = dictionary.FindEntry(isolate, key);
           if ((entry.is_found()) &&
               (dictionary.DetailsAt(entry).kind() == kData)) {
@@ -754,22 +781,21 @@ RUNTIME_FUNCTION(Runtime_GetProperty) {
       // transition elements to FAST_*_ELEMENTS to avoid excessive boxing of
       // doubles for those future calls in the case that the elements would
       // become PACKED_DOUBLE_ELEMENTS.
-      Handle<JSObject> js_object = Handle<JSObject>::cast(holder_obj);
-      ElementsKind elements_kind = js_object->GetElementsKind();
+      ElementsKind elements_kind = lookup_start_object->GetElementsKind();
       if (IsDoubleElementsKind(elements_kind)) {
-        if (Smi::ToInt(*key_obj) >= js_object->elements().length()) {
+        if (Smi::ToInt(*key_obj) >= lookup_start_object->elements().length()) {
           elements_kind = IsHoleyElementsKind(elements_kind) ? HOLEY_ELEMENTS
                                                              : PACKED_ELEMENTS;
-          JSObject::TransitionElementsKind(js_object, elements_kind);
+          JSObject::TransitionElementsKind(lookup_start_object, elements_kind);
         }
       } else {
         DCHECK(IsSmiOrObjectElementsKind(elements_kind) ||
                !IsFastElementsKind(elements_kind));
       }
     }
-  } else if (holder_obj->IsString() && key_obj->IsSmi()) {
+  } else if (lookup_start_obj->IsString() && key_obj->IsSmi()) {
     // Fast case for string indexing using [] with a smi index.
-    Handle<String> str = Handle<String>::cast(holder_obj);
+    Handle<String> str = Handle<String>::cast(lookup_start_obj);
     int index = Handle<Smi>::cast(key_obj)->value();
     if (index >= 0 && index < str->length()) {
       Factory* factory = isolate->factory();
@@ -780,8 +806,8 @@ RUNTIME_FUNCTION(Runtime_GetProperty) {
 
   // Fall back to GetObjectProperty.
   RETURN_RESULT_OR_FAILURE(
-      isolate,
-      Runtime::GetObjectProperty(isolate, holder_obj, key_obj, receiver_obj));
+      isolate, Runtime::GetObjectProperty(isolate, lookup_start_obj, key_obj,
+                                          receiver_obj));
 }
 
 RUNTIME_FUNCTION(Runtime_SetKeyedProperty) {
@@ -947,11 +973,16 @@ RUNTIME_FUNCTION(Runtime_NewObject) {
 
 RUNTIME_FUNCTION(Runtime_GetDerivedMap) {
   HandleScope scope(isolate);
-  DCHECK_EQ(2, args.length());
+  DCHECK_EQ(3, args.length());
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, target, 0);
   CONVERT_ARG_HANDLE_CHECKED(JSReceiver, new_target, 1);
-  RETURN_RESULT_OR_FAILURE(
-      isolate, JSFunction::GetDerivedMap(isolate, target, new_target));
+  CONVERT_ARG_HANDLE_CHECKED(Object, rab_gsab, 2);
+  if (rab_gsab->IsTrue()) {
+    return *JSFunction::GetDerivedRabGsabMap(isolate, target, new_target);
+  } else {
+    RETURN_RESULT_OR_FAILURE(
+        isolate, JSFunction::GetDerivedMap(isolate, target, new_target));
+  }
 }
 
 RUNTIME_FUNCTION(Runtime_CompleteInobjectSlackTrackingForMap) {
diff --git a/chromium/v8/src/runtime/runtime-promise.cc b/chromium/v8/src/runtime/runtime-promise.cc
index c1ee96facca..0ade310cfb5 100644
--- a/chromium/v8/src/runtime/runtime-promise.cc
+++ b/chromium/v8/src/runtime/runtime-promise.cc
@@ -29,8 +29,8 @@ RUNTIME_FUNCTION(Runtime_PromiseRejectEventFromStack) {
     // undefined, which we interpret as being a caught exception event.
     rejected_promise = isolate->GetPromiseOnStackOnThrow();
   }
-  isolate->RunPromiseHook(PromiseHookType::kResolve, promise,
-                          isolate->factory()->undefined_value());
+  isolate->RunAllPromiseHooks(PromiseHookType::kResolve, promise,
+                              isolate->factory()->undefined_value());
   isolate->debug()->OnPromiseReject(rejected_promise, value);
 
   // Report only if we don't actually have a handler.
@@ -142,7 +142,7 @@ Handle<JSPromise> AwaitPromisesInitCommon(Isolate* isolate,
   // hook for the throwaway promise (passing the {promise} as its
   // parent).
   Handle<JSPromise> throwaway = isolate->factory()->NewJSPromiseWithoutHook();
-  isolate->RunPromiseHook(PromiseHookType::kInit, throwaway, promise);
+  isolate->RunAllPromiseHooks(PromiseHookType::kInit, throwaway, promise);
 
   // On inspector side we capture async stack trace and store it by
   // outer_promise->async_task_id when async function is suspended first time.
@@ -204,7 +204,7 @@ RUNTIME_FUNCTION(Runtime_AwaitPromisesInitOld) {
 
   // Fire the init hook for the wrapper promise (that we created for the
   // {value} previously).
-  isolate->RunPromiseHook(PromiseHookType::kInit, promise, outer_promise);
+  isolate->RunAllPromiseHooks(PromiseHookType::kInit, promise, outer_promise);
   return *AwaitPromisesInitCommon(isolate, value, promise, outer_promise,
                                   reject_handler, is_predicted_as_caught);
 }
@@ -260,17 +260,18 @@ RUNTIME_FUNCTION(Runtime_ResolvePromise) {
 // takes care of the Error-related construction, e.g., stack traces.
 RUNTIME_FUNCTION(Runtime_ConstructAggregateErrorHelper) {
   HandleScope scope(isolate);
-  DCHECK_EQ(3, args.length());
+  DCHECK_EQ(4, args.length());
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, target, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, new_target, 1);
   CONVERT_ARG_HANDLE_CHECKED(Object, message, 2);
+  CONVERT_ARG_HANDLE_CHECKED(Object, options, 3);
 
   DCHECK_EQ(*target, *isolate->aggregate_error_function());
 
   Handle<Object> result;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
       isolate, result,
-      ErrorUtils::Construct(isolate, target, new_target, message));
+      ErrorUtils::Construct(isolate, target, new_target, message, options));
   return *result;
 }
 
@@ -299,6 +300,14 @@ RUNTIME_FUNCTION(Runtime_ConstructInternalAggregateErrorHelper) {
     arg2 = args.at<Object>(3);
   }
 
+  Handle<Object> options;
+  if (args.length() >= 5) {
+    CHECK(args[4].IsObject());
+    options = args.at<Object>(4);
+  } else {
+    options = isolate->factory()->undefined_value();
+  }
+
   Handle<Object> message_string = MessageFormatter::Format(
       isolate, MessageTemplate(message->value()), arg0, arg1, arg2);
 
@@ -306,8 +315,8 @@ RUNTIME_FUNCTION(Runtime_ConstructInternalAggregateErrorHelper) {
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
       isolate, result,
       ErrorUtils::Construct(isolate, isolate->aggregate_error_function(),
-                            isolate->aggregate_error_function(),
-                            message_string));
+                            isolate->aggregate_error_function(), message_string,
+                            options));
   return *result;
 }
 
diff --git a/chromium/v8/src/runtime/runtime-regexp.cc b/chromium/v8/src/runtime/runtime-regexp.cc
index d18602f58f7..f80316e34dd 100644
--- a/chromium/v8/src/runtime/runtime-regexp.cc
+++ b/chromium/v8/src/runtime/runtime-regexp.cc
@@ -1696,7 +1696,7 @@ RUNTIME_FUNCTION(Runtime_RegExpSplit) {
 
     if (!result->IsNull(isolate)) return *factory->NewJSArray(0);
 
-    Handle<FixedArray> elems = factory->NewUninitializedFixedArray(1);
+    Handle<FixedArray> elems = factory->NewFixedArray(1);
     elems->set(0, *string);
     return *factory->NewJSArrayWithElements(elems);
   }
@@ -2004,5 +2004,13 @@ RUNTIME_FUNCTION(Runtime_IsRegExp) {
   return isolate->heap()->ToBoolean(obj.IsJSRegExp());
 }
 
+RUNTIME_FUNCTION(Runtime_RegExpStringFromFlags) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_CHECKED(JSRegExp, regexp, 0);
+  Handle<String> flags = JSRegExp::StringFromFlags(isolate, regexp.GetFlags());
+  return *flags;
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/runtime/runtime-scopes.cc b/chromium/v8/src/runtime/runtime-scopes.cc
index 457f3729556..e925e1f7f99 100644
--- a/chromium/v8/src/runtime/runtime-scopes.cc
+++ b/chromium/v8/src/runtime/runtime-scopes.cc
@@ -510,7 +510,7 @@ RUNTIME_FUNCTION(Runtime_NewStrictArguments) {
       isolate->factory()->NewArgumentsObject(callee, argument_count);
   if (argument_count) {
     Handle<FixedArray> array =
-        isolate->factory()->NewUninitializedFixedArray(argument_count);
+        isolate->factory()->NewFixedArray(argument_count);
     DisallowGarbageCollection no_gc;
     WriteBarrierMode mode = array->GetWriteBarrierMode(no_gc);
     for (int i = 0; i < argument_count; i++) {
@@ -859,7 +859,7 @@ RUNTIME_FUNCTION(Runtime_StoreLookupSlot_SloppyHoisting) {
                                LanguageMode::kSloppy, lookup_flags));
 }
 
-RUNTIME_FUNCTION(Runtime_StoreGlobalNoHoleCheckForReplLet) {
+RUNTIME_FUNCTION(Runtime_StoreGlobalNoHoleCheckForReplLetOrConst) {
   HandleScope scope(isolate);
   DCHECK_EQ(2, args.length());
   CONVERT_ARG_HANDLE_CHECKED(String, name, 0);
diff --git a/chromium/v8/src/runtime/runtime-strings.cc b/chromium/v8/src/runtime/runtime-strings.cc
index 0acf6334d44..bd651c646c6 100644
--- a/chromium/v8/src/runtime/runtime-strings.cc
+++ b/chromium/v8/src/runtime/runtime-strings.cc
@@ -315,7 +315,7 @@ RUNTIME_FUNCTION(Runtime_StringToArray) {
   int position = 0;
   if (s->IsFlat() && s->IsOneByteRepresentation()) {
     // Try using cached chars where possible.
-    elements = isolate->factory()->NewUninitializedFixedArray(length);
+    elements = isolate->factory()->NewFixedArray(length);
 
     DisallowGarbageCollection no_gc;
     String::FlatContent content = s->GetFlatContent(no_gc);
diff --git a/chromium/v8/src/runtime/runtime-test-wasm.cc b/chromium/v8/src/runtime/runtime-test-wasm.cc
index 9c07441de55..54976dcc05b 100644
--- a/chromium/v8/src/runtime/runtime-test-wasm.cc
+++ b/chromium/v8/src/runtime/runtime-test-wasm.cc
@@ -158,8 +158,7 @@ RUNTIME_FUNCTION(Runtime_WasmTraceEnter) {
   wasm::ModuleWireBytes wire_bytes =
       wasm::ModuleWireBytes(frame->native_module()->wire_bytes());
   wasm::WireBytesRef name_ref =
-      module->lazily_generated_names.LookupFunctionName(
-          wire_bytes, func_index, VectorOf(module->export_table));
+      module->lazily_generated_names.LookupFunctionName(wire_bytes, func_index);
   wasm::WasmName name = wire_bytes.GetNameOrNull(name_ref);
 
   wasm::WasmCode* code = frame->wasm_code();
@@ -423,14 +422,10 @@ RUNTIME_FUNCTION(Runtime_WasmTraceMemory) {
       frame->wasm_instance().memory_object().array_buffer().backing_store());
   int func_index = frame->function_index();
   int pos = frame->position();
-  // TODO(titzer): eliminate dependency on WasmModule definition here.
-  int func_start =
-      frame->wasm_instance().module()->functions[func_index].code.offset();
   wasm::ExecutionTier tier = frame->wasm_code()->is_liftoff()
                                  ? wasm::ExecutionTier::kLiftoff
                                  : wasm::ExecutionTier::kTurbofan;
-  wasm::TraceMemoryOperation(tier, info, func_index, pos - func_start,
-                             mem_start);
+  wasm::TraceMemoryOperation(tier, info, func_index, pos, mem_start);
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
diff --git a/chromium/v8/src/runtime/runtime-test.cc b/chromium/v8/src/runtime/runtime-test.cc
index 0dd7368e39e..00a4124dcef 100644
--- a/chromium/v8/src/runtime/runtime-test.cc
+++ b/chromium/v8/src/runtime/runtime-test.cc
@@ -4,6 +4,7 @@
 
 #include "src/api/api-inl.h"
 #include "src/base/platform/mutex.h"
+#include "src/baseline/baseline-osr-inl.h"
 #include "src/codegen/assembler-inl.h"
 #include "src/codegen/compiler.h"
 #include "src/codegen/pending-optimization-table.h"
@@ -41,6 +42,11 @@ V8_WARN_UNUSED_RESULT Object CrashUnlessFuzzing(Isolate* isolate) {
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
+// Returns |value| unless fuzzing is enabled, otherwise returns undefined_value.
+V8_WARN_UNUSED_RESULT Object ReturnFuzzSafe(Object value, Isolate* isolate) {
+  return FLAG_fuzzing ? ReadOnlyRoots(isolate).undefined_value() : value;
+}
+
 // Assert that the given argument is a number within the Int32 range
 // and convert it to int32_t.  If the argument is not an Int32 we crash if not
 // in fuzzing mode.
@@ -470,6 +476,37 @@ RUNTIME_FUNCTION(Runtime_OptimizeOsr) {
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
+RUNTIME_FUNCTION(Runtime_BaselineOsr) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 0 || args.length() == 1);
+
+  Handle<JSFunction> function;
+
+  // The optional parameter determines the frame being targeted.
+  int stack_depth = 0;
+  if (args.length() == 1) {
+    if (!args[0].IsSmi()) return CrashUnlessFuzzing(isolate);
+    stack_depth = args.smi_at(0);
+  }
+
+  // Find the JavaScript function on the top of the stack.
+  JavaScriptFrameIterator it(isolate);
+  while (!it.done() && stack_depth--) it.Advance();
+  if (!it.done()) function = handle(it.frame()->function(), isolate);
+  if (function.is_null()) return CrashUnlessFuzzing(isolate);
+  if (!FLAG_sparkplug || !FLAG_use_osr) {
+    return ReadOnlyRoots(isolate).undefined_value();
+  }
+  if (!it.frame()->is_unoptimized()) {
+    return ReadOnlyRoots(isolate).undefined_value();
+  }
+
+  UnoptimizedFrame* frame = UnoptimizedFrame::cast(it.frame());
+  OSRInterpreterFrameToBaseline(isolate, function, frame);
+
+  return ReadOnlyRoots(isolate).undefined_value();
+}
+
 RUNTIME_FUNCTION(Runtime_NeverOptimizeFunction) {
   HandleScope scope(isolate);
   DCHECK_EQ(1, args.length());
@@ -576,6 +613,11 @@ RUNTIME_FUNCTION(Runtime_GetOptimizationStatus) {
     if (frame->is_optimized()) {
       status |=
           static_cast<int>(OptimizationStatus::kTopmostFrameIsTurboFanned);
+    } else if (frame->is_interpreted()) {
+      status |=
+          static_cast<int>(OptimizationStatus::kTopmostFrameIsInterpreted);
+    } else if (frame->is_baseline()) {
+      status |= static_cast<int>(OptimizationStatus::kTopmostFrameIsBaseline);
     }
   }
 
@@ -678,6 +720,7 @@ int FixedArrayLenFromSize(int size) {
 }
 
 void FillUpOneNewSpacePage(Isolate* isolate, Heap* heap) {
+  DCHECK(!FLAG_single_generation);
   PauseAllocationObserversScope pause_observers(heap);
   NewSpace* space = heap->new_space();
   // We cannot rely on `space->limit()` to point to the end of the current page
@@ -990,6 +1033,25 @@ RUNTIME_FUNCTION(Runtime_InYoungGeneration) {
   return isolate->heap()->ToBoolean(ObjectInYoungGeneration(obj));
 }
 
+// Force pretenuring for the allocation site the passed object belongs to.
+RUNTIME_FUNCTION(Runtime_PretenureAllocationSite) {
+  DisallowGarbageCollection no_gc;
+
+  if (args.length() != 1) return CrashUnlessFuzzing(isolate);
+  CONVERT_ARG_CHECKED(Object, arg, 0);
+  if (!arg.IsJSObject()) return CrashUnlessFuzzing(isolate);
+  JSObject object = JSObject::cast(arg);
+
+  Heap* heap = object.GetHeap();
+  AllocationMemento memento =
+      heap->FindAllocationMemento<Heap::kForRuntime>(object.map(), object);
+  if (memento.is_null())
+    return ReturnFuzzSafe(ReadOnlyRoots(isolate).false_value(), isolate);
+  AllocationSite site = memento.GetAllocationSite();
+  heap->PretenureAllocationSiteOnNextCollection(site);
+  return ReturnFuzzSafe(ReadOnlyRoots(isolate).true_value(), isolate);
+}
+
 namespace {
 
 v8::ModifyCodeGenerationFromStringsResult DisallowCodegenFromStringsCallback(
@@ -1257,6 +1319,7 @@ RUNTIME_FUNCTION(Runtime_EnableCodeLoggingForTesting) {
                                Handle<String> source) final {}
     void CodeMoveEvent(AbstractCode from, AbstractCode to) final {}
     void SharedFunctionInfoMoveEvent(Address from, Address to) final {}
+    void NativeContextMoveEvent(Address from, Address to) final {}
     void CodeMovingGCEvent() final {}
     void CodeDisableOptEvent(Handle<AbstractCode> code,
                              Handle<SharedFunctionInfo> shared) final {}
@@ -1294,5 +1357,11 @@ RUNTIME_FUNCTION(Runtime_NewRegExpWithBacktrackLimit) {
       isolate, JSRegExp::New(isolate, pattern, flags, backtrack_limit));
 }
 
+RUNTIME_FUNCTION(Runtime_Is64Bit) {
+  SealHandleScope shs(isolate);
+  DCHECK_EQ(0, args.length());
+  return isolate->heap()->ToBoolean(kSystemPointerSize == 8);
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/runtime/runtime-typedarray.cc b/chromium/v8/src/runtime/runtime-typedarray.cc
index b73cfc9769a..5d0fc35944a 100644
--- a/chromium/v8/src/runtime/runtime-typedarray.cc
+++ b/chromium/v8/src/runtime/runtime-typedarray.cc
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "src/base/atomicops.h"
 #include "src/common/message-template.h"
 #include "src/execution/arguments-inl.h"
 #include "src/heap/factory.h"
@@ -52,6 +53,15 @@ RUNTIME_FUNCTION(Runtime_TypedArrayGetBuffer) {
   return *holder->GetBuffer();
 }
 
+RUNTIME_FUNCTION(Runtime_GrowableSharedArrayBufferByteLength) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(JSArrayBuffer, array_buffer, 0);
+
+  CHECK_EQ(0, array_buffer->byte_length());
+  size_t byte_length = array_buffer->GetBackingStore()->byte_length();
+  return *isolate->factory()->NewNumberFromSize(byte_length);
+}
 
 namespace {
 
@@ -84,6 +94,14 @@ RUNTIME_FUNCTION(Runtime_TypedArraySortFast) {
   CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, array, 0);
   DCHECK(!array->WasDetached());
 
+#if V8_OS_LINUX
+  if (FLAG_multi_mapped_mock_allocator) {
+    // Sorting is meaningless with the mock allocator, and std::sort
+    // might crash (because aliasing elements violate its assumptions).
+    return *array;
+  }
+#endif
+
   size_t length = array->length();
   DCHECK_LT(1, length);
 
@@ -108,7 +126,8 @@ RUNTIME_FUNCTION(Runtime_TypedArraySortFast) {
       offheap_copy.resize(bytes);
       data_copy_ptr = &offheap_copy[0];
     }
-    std::memcpy(data_copy_ptr, static_cast<void*>(array->DataPtr()), bytes);
+    base::Relaxed_Memcpy(static_cast<base::Atomic8*>(data_copy_ptr),
+                         static_cast<base::Atomic8*>(array->DataPtr()), bytes);
   }
 
   DisallowGarbageCollection no_gc;
@@ -147,7 +166,8 @@ RUNTIME_FUNCTION(Runtime_TypedArraySortFast) {
     DCHECK_NOT_NULL(data_copy_ptr);
     DCHECK_NE(array_copy.is_null(), offheap_copy.empty());
     const size_t bytes = array->byte_length();
-    std::memcpy(static_cast<void*>(array->DataPtr()), data_copy_ptr, bytes);
+    base::Relaxed_Memcpy(static_cast<base::Atomic8*>(array->DataPtr()),
+                         static_cast<base::Atomic8*>(data_copy_ptr), bytes);
   }
 
   return *array;
diff --git a/chromium/v8/src/runtime/runtime.cc b/chromium/v8/src/runtime/runtime.cc
index c1b287cae37..9e553b12af1 100644
--- a/chromium/v8/src/runtime/runtime.cc
+++ b/chromium/v8/src/runtime/runtime.cc
@@ -209,6 +209,7 @@ bool Runtime::IsAllowListedForFuzzing(FunctionId id) {
     case Runtime::kOptimizeFunctionOnNextCall:
     case Runtime::kOptimizeOsr:
     case Runtime::kPrepareFunctionForOptimization:
+    case Runtime::kPretenureAllocationSite:
     case Runtime::kSetAllocationTimeout:
     case Runtime::kSimulateNewspaceFull:
       return true;
@@ -218,8 +219,10 @@ bool Runtime::IsAllowListedForFuzzing(FunctionId id) {
     case Runtime::kGetOptimizationStatus:
     case Runtime::kHeapObjectVerify:
     case Runtime::kIsBeingInterpreted:
+    case Runtime::kVerifyType:
       return !FLAG_allow_natives_for_differential_fuzzing;
     case Runtime::kCompileBaseline:
+    case Runtime::kBaselineOsr:
       return FLAG_sparkplug;
     default:
       return false;
diff --git a/chromium/v8/src/runtime/runtime.h b/chromium/v8/src/runtime/runtime.h
index 578156f0942..eea742f2c99 100644
--- a/chromium/v8/src/runtime/runtime.h
+++ b/chromium/v8/src/runtime/runtime.h
@@ -115,7 +115,7 @@ namespace internal {
   F(NotifyDeoptimized, 0, 1)              \
   F(ObserveNode, 1, 1)                    \
   F(ResolvePossiblyDirectEval, 6, 1)      \
-  F(TryInstallNCICode, 1, 1)
+  F(VerifyType, 1, 1)
 
 #define FOR_EACH_INTRINSIC_DATE(F, I) F(DateCurrentTime, 0, 1)
 
@@ -343,7 +343,7 @@ namespace internal {
   I(ToNumber, 1, 1)                                             \
   F(ToNumeric, 1, 1)                                            \
   I(ToObject, 1, 1)                                             \
-  I(ToString, 1, 1)                                             \
+  F(ToString, 1, 1)                                             \
   F(TryMigrateInstance, 1, 1)                                   \
   F(SwissTableAdd, 4, 1)                                        \
   F(SwissTableAllocate, 1, 1)                                   \
@@ -383,8 +383,8 @@ namespace internal {
   F(ResolvePromise, 2, 1)                \
   F(PromiseRejectAfterResolved, 2, 1)    \
   F(PromiseResolveAfterResolved, 2, 1)   \
-  F(ConstructAggregateErrorHelper, 3, 1) \
-  F(ConstructInternalAggregateErrorHelper, -1 /* <= 4*/, 1)
+  F(ConstructAggregateErrorHelper, 4, 1) \
+  F(ConstructInternalAggregateErrorHelper, -1 /* <= 5*/, 1)
 
 #define FOR_EACH_INTRINSIC_PROXY(F, I) \
   F(CheckProxyGetSetTrapResult, 2, 1)  \
@@ -407,31 +407,32 @@ namespace internal {
   F(RegExpInitializeAndCompile, 3, 1)                            \
   F(RegExpReplaceRT, 3, 1)                                       \
   F(RegExpSplit, 3, 1)                                           \
+  F(RegExpStringFromFlags, 1, 1)                                 \
   F(StringReplaceNonGlobalRegExpWithFunction, 3, 1)              \
   F(StringSplit, 3, 1)
 
-#define FOR_EACH_INTRINSIC_SCOPES(F, I)     \
-  F(DeclareEvalFunction, 2, 1)              \
-  F(DeclareEvalVar, 1, 1)                   \
-  F(DeclareGlobals, 2, 1)                   \
-  F(DeclareModuleExports, 2, 1)             \
-  F(DeleteLookupSlot, 1, 1)                 \
-  F(LoadLookupSlot, 1, 1)                   \
-  F(LoadLookupSlotInsideTypeof, 1, 1)       \
-                                            \
-  F(NewClosure, 2, 1)                       \
-  F(NewClosure_Tenured, 2, 1)               \
-  F(NewFunctionContext, 1, 1)               \
-  F(NewRestParameter, 1, 1)                 \
-  F(NewSloppyArguments, 1, 1)               \
-  F(NewStrictArguments, 1, 1)               \
-  F(PushBlockContext, 1, 1)                 \
-  F(PushCatchContext, 2, 1)                 \
-  F(PushWithContext, 2, 1)                  \
-  F(StoreGlobalNoHoleCheckForReplLet, 2, 1) \
-  F(StoreLookupSlot_Sloppy, 2, 1)           \
-  F(StoreLookupSlot_SloppyHoisting, 2, 1)   \
-  F(StoreLookupSlot_Strict, 2, 1)           \
+#define FOR_EACH_INTRINSIC_SCOPES(F, I)            \
+  F(DeclareEvalFunction, 2, 1)                     \
+  F(DeclareEvalVar, 1, 1)                          \
+  F(DeclareGlobals, 2, 1)                          \
+  F(DeclareModuleExports, 2, 1)                    \
+  F(DeleteLookupSlot, 1, 1)                        \
+  F(LoadLookupSlot, 1, 1)                          \
+  F(LoadLookupSlotInsideTypeof, 1, 1)              \
+                                                   \
+  F(NewClosure, 2, 1)                              \
+  F(NewClosure_Tenured, 2, 1)                      \
+  F(NewFunctionContext, 1, 1)                      \
+  F(NewRestParameter, 1, 1)                        \
+  F(NewSloppyArguments, 1, 1)                      \
+  F(NewStrictArguments, 1, 1)                      \
+  F(PushBlockContext, 1, 1)                        \
+  F(PushCatchContext, 2, 1)                        \
+  F(PushWithContext, 2, 1)                         \
+  F(StoreGlobalNoHoleCheckForReplLetOrConst, 2, 1) \
+  F(StoreLookupSlot_Sloppy, 2, 1)                  \
+  F(StoreLookupSlot_SloppyHoisting, 2, 1)          \
+  F(StoreLookupSlot_Strict, 2, 1)                  \
   F(ThrowConstAssignError, 0, 1)
 
 #define FOR_EACH_INTRINSIC_STRINGS(F, I)  \
@@ -460,104 +461,108 @@ namespace internal {
   F(SymbolDescriptiveString, 1, 1)         \
   F(SymbolIsPrivate, 1, 1)
 
-#define FOR_EACH_INTRINSIC_TEST(F, I)          \
-  F(Abort, 1, 1)                               \
-  F(AbortJS, 1, 1)                             \
-  F(AbortCSAAssert, 1, 1)                      \
-  F(ArraySpeciesProtector, 0, 1)               \
-  F(ClearFunctionFeedback, 1, 1)               \
-  F(ClearMegamorphicStubCache, 0, 1)           \
-  F(CompleteInobjectSlackTracking, 1, 1)       \
-  F(ConstructConsString, 2, 1)                 \
-  F(ConstructDouble, 2, 1)                     \
-  F(ConstructSlicedString, 2, 1)               \
-  F(DebugPrint, 1, 1)                          \
-  F(DebugPrintPtr, 1, 1)                       \
-  F(DebugTrace, 0, 1)                          \
-  F(DebugTrackRetainingPath, -1, 1)            \
-  F(DeoptimizeFunction, 1, 1)                  \
-  F(DisallowCodegenFromStrings, 1, 1)          \
-  F(DisassembleFunction, 1, 1)                 \
-  F(DynamicCheckMapsEnabled, 0, 1)             \
-  F(IsTopTierTurboprop, 0, 1)                  \
-  F(IsMidTierTurboprop, 0, 1)                  \
-  F(EnableCodeLoggingForTesting, 0, 1)         \
-  F(EnsureFeedbackVectorForFunction, 1, 1)     \
-  F(GetCallable, 0, 1)                         \
-  F(GetInitializerFunction, 1, 1)              \
-  F(GetOptimizationStatus, -1, 1)              \
-  F(GetUndetectable, 0, 1)                     \
-  F(GlobalPrint, 1, 1)                         \
-  F(HasDictionaryElements, 1, 1)               \
-  F(HasDoubleElements, 1, 1)                   \
-  F(HasElementsInALargeObjectSpace, 1, 1)      \
-  F(HasFastElements, 1, 1)                     \
-  F(HasFastProperties, 1, 1)                   \
-  F(HasOwnConstDataProperty, 2, 1)             \
-  F(HasFixedBigInt64Elements, 1, 1)            \
-  F(HasFixedBigUint64Elements, 1, 1)           \
-  F(HasFixedFloat32Elements, 1, 1)             \
-  F(HasFixedFloat64Elements, 1, 1)             \
-  F(HasFixedInt16Elements, 1, 1)               \
-  F(HasFixedInt32Elements, 1, 1)               \
-  F(HasFixedInt8Elements, 1, 1)                \
-  F(HasFixedUint16Elements, 1, 1)              \
-  F(HasFixedUint32Elements, 1, 1)              \
-  F(HasFixedUint8ClampedElements, 1, 1)        \
-  F(HasFixedUint8Elements, 1, 1)               \
-  F(HasHoleyElements, 1, 1)                    \
-  F(HasObjectElements, 1, 1)                   \
-  F(HasPackedElements, 1, 1)                   \
-  F(HasSloppyArgumentsElements, 1, 1)          \
-  F(HasSmiElements, 1, 1)                      \
-  F(HasSmiOrObjectElements, 1, 1)              \
-  F(HaveSameMap, 2, 1)                         \
-  F(HeapObjectVerify, 1, 1)                    \
-  F(ICsAreEnabled, 0, 1)                       \
-  F(InLargeObjectSpace, 1, 1)                  \
-  F(InYoungGeneration, 1, 1)                   \
-  F(IsBeingInterpreted, 0, 1)                  \
-  F(IsConcurrentRecompilationSupported, 0, 1)  \
-  F(IsDictPropertyConstTrackingEnabled, 0, 1)  \
-  F(RegexpHasBytecode, 2, 1)                   \
-  F(RegexpHasNativeCode, 2, 1)                 \
-  F(RegexpTypeTag, 1, 1)                       \
-  F(RegexpIsUnmodified, 1, 1)                  \
-  F(MapIteratorProtector, 0, 1)                \
-  F(ArrayIteratorProtector, 0, 1)              \
-  F(NeverOptimizeFunction, 1, 1)               \
-  F(NotifyContextDisposed, 0, 1)               \
-  F(OptimizeFunctionOnNextCall, -1, 1)         \
-  F(TierupFunctionOnNextCall, -1, 1)           \
-  F(OptimizeOsr, -1, 1)                        \
-  F(NewRegExpWithBacktrackLimit, 3, 1)         \
-  F(PrepareFunctionForOptimization, -1, 1)     \
-  F(PrintWithNameForAssert, 2, 1)              \
-  F(RunningInSimulator, 0, 1)                  \
-  F(RuntimeEvaluateREPL, 1, 1)                 \
-  F(SerializeDeserializeNow, 0, 1)             \
-  F(SetAllocationTimeout, -1 /* 2 || 3 */, 1)  \
-  F(SetForceSlowPath, 1, 1)                    \
-  F(SetIteratorProtector, 0, 1)                \
-  F(SimulateNewspaceFull, 0, 1)                \
-  F(ScheduleGCInStackCheck, 0, 1)              \
-  F(StringIteratorProtector, 0, 1)             \
-  F(SystemBreak, 0, 1)                         \
-  F(TraceEnter, 0, 1)                          \
-  F(TraceExit, 1, 1)                           \
-  F(TurbofanStaticAssert, 1, 1)                \
-  F(TypedArraySpeciesProtector, 0, 1)          \
-  F(UnblockConcurrentRecompilation, 0, 1)      \
-  I(DeoptimizeNow, 0, 1)                       \
-  F(PromiseSpeciesProtector, 0, 1)             \
-  F(IsConcatSpreadableProtector, 0, 1)         \
-  F(RegExpSpeciesProtector, 0, 1)
-
-#define FOR_EACH_INTRINSIC_TYPEDARRAY(F, I) \
-  F(ArrayBufferDetach, 1, 1)                \
-  F(TypedArrayCopyElements, 3, 1)           \
-  F(TypedArrayGetBuffer, 1, 1)              \
-  F(TypedArraySet, 2, 1)                    \
+#define FOR_EACH_INTRINSIC_TEST(F, I)         \
+  F(Abort, 1, 1)                              \
+  F(AbortJS, 1, 1)                            \
+  F(AbortCSAAssert, 1, 1)                     \
+  F(ArraySpeciesProtector, 0, 1)              \
+  F(BaselineOsr, -1, 1)                       \
+  F(ClearFunctionFeedback, 1, 1)              \
+  F(ClearMegamorphicStubCache, 0, 1)          \
+  F(CompleteInobjectSlackTracking, 1, 1)      \
+  F(ConstructConsString, 2, 1)                \
+  F(ConstructDouble, 2, 1)                    \
+  F(ConstructSlicedString, 2, 1)              \
+  F(DebugPrint, 1, 1)                         \
+  F(DebugPrintPtr, 1, 1)                      \
+  F(DebugTrace, 0, 1)                         \
+  F(DebugTrackRetainingPath, -1, 1)           \
+  F(DeoptimizeFunction, 1, 1)                 \
+  F(DisallowCodegenFromStrings, 1, 1)         \
+  F(DisassembleFunction, 1, 1)                \
+  F(DynamicCheckMapsEnabled, 0, 1)            \
+  F(IsTopTierTurboprop, 0, 1)                 \
+  F(IsMidTierTurboprop, 0, 1)                 \
+  F(EnableCodeLoggingForTesting, 0, 1)        \
+  F(EnsureFeedbackVectorForFunction, 1, 1)    \
+  F(GetCallable, 0, 1)                        \
+  F(GetInitializerFunction, 1, 1)             \
+  F(GetOptimizationStatus, -1, 1)             \
+  F(GetUndetectable, 0, 1)                    \
+  F(GlobalPrint, 1, 1)                        \
+  F(HasDictionaryElements, 1, 1)              \
+  F(HasDoubleElements, 1, 1)                  \
+  F(HasElementsInALargeObjectSpace, 1, 1)     \
+  F(HasFastElements, 1, 1)                    \
+  F(HasFastProperties, 1, 1)                  \
+  F(HasOwnConstDataProperty, 2, 1)            \
+  F(HasFixedBigInt64Elements, 1, 1)           \
+  F(HasFixedBigUint64Elements, 1, 1)          \
+  F(HasFixedFloat32Elements, 1, 1)            \
+  F(HasFixedFloat64Elements, 1, 1)            \
+  F(HasFixedInt16Elements, 1, 1)              \
+  F(HasFixedInt32Elements, 1, 1)              \
+  F(HasFixedInt8Elements, 1, 1)               \
+  F(HasFixedUint16Elements, 1, 1)             \
+  F(HasFixedUint32Elements, 1, 1)             \
+  F(HasFixedUint8ClampedElements, 1, 1)       \
+  F(HasFixedUint8Elements, 1, 1)              \
+  F(HasHoleyElements, 1, 1)                   \
+  F(HasObjectElements, 1, 1)                  \
+  F(HasPackedElements, 1, 1)                  \
+  F(HasSloppyArgumentsElements, 1, 1)         \
+  F(HasSmiElements, 1, 1)                     \
+  F(HasSmiOrObjectElements, 1, 1)             \
+  F(HaveSameMap, 2, 1)                        \
+  F(HeapObjectVerify, 1, 1)                   \
+  F(ICsAreEnabled, 0, 1)                      \
+  F(InLargeObjectSpace, 1, 1)                 \
+  F(InYoungGeneration, 1, 1)                  \
+  F(IsBeingInterpreted, 0, 1)                 \
+  F(IsConcurrentRecompilationSupported, 0, 1) \
+  F(IsDictPropertyConstTrackingEnabled, 0, 1) \
+  F(RegexpHasBytecode, 2, 1)                  \
+  F(RegexpHasNativeCode, 2, 1)                \
+  F(RegexpTypeTag, 1, 1)                      \
+  F(RegexpIsUnmodified, 1, 1)                 \
+  F(MapIteratorProtector, 0, 1)               \
+  F(ArrayIteratorProtector, 0, 1)             \
+  F(NeverOptimizeFunction, 1, 1)              \
+  F(NotifyContextDisposed, 0, 1)              \
+  F(OptimizeFunctionOnNextCall, -1, 1)        \
+  F(TierupFunctionOnNextCall, -1, 1)          \
+  F(OptimizeOsr, -1, 1)                       \
+  F(NewRegExpWithBacktrackLimit, 3, 1)        \
+  F(PrepareFunctionForOptimization, -1, 1)    \
+  F(PretenureAllocationSite, 1, 1)            \
+  F(PrintWithNameForAssert, 2, 1)             \
+  F(RunningInSimulator, 0, 1)                 \
+  F(RuntimeEvaluateREPL, 1, 1)                \
+  F(SerializeDeserializeNow, 0, 1)            \
+  F(SetAllocationTimeout, -1 /* 2 || 3 */, 1) \
+  F(SetForceSlowPath, 1, 1)                   \
+  F(SetIteratorProtector, 0, 1)               \
+  F(SimulateNewspaceFull, 0, 1)               \
+  F(ScheduleGCInStackCheck, 0, 1)             \
+  F(StringIteratorProtector, 0, 1)            \
+  F(SystemBreak, 0, 1)                        \
+  F(TraceEnter, 0, 1)                         \
+  F(TraceExit, 1, 1)                          \
+  F(TurbofanStaticAssert, 1, 1)               \
+  F(TypedArraySpeciesProtector, 0, 1)         \
+  F(UnblockConcurrentRecompilation, 0, 1)     \
+  I(DeoptimizeNow, 0, 1)                      \
+  F(PromiseSpeciesProtector, 0, 1)            \
+  F(IsConcatSpreadableProtector, 0, 1)        \
+  F(RegExpSpeciesProtector, 0, 1)             \
+  F(Is64Bit, 0, 1)
+
+#define FOR_EACH_INTRINSIC_TYPEDARRAY(F, I)    \
+  F(ArrayBufferDetach, 1, 1)                   \
+  F(GrowableSharedArrayBufferByteLength, 1, 1) \
+  F(TypedArrayCopyElements, 3, 1)              \
+  F(TypedArrayGetBuffer, 1, 1)                 \
+  F(TypedArraySet, 2, 1)                       \
   F(TypedArraySortFast, 1, 1)
 
 #define FOR_EACH_INTRINSIC_WASM(F, I) \
@@ -784,9 +789,10 @@ class Runtime : public AllStatic {
                     Handle<Object> value, StoreOrigin store_origin,
                     Maybe<ShouldThrow> should_throw = Nothing<ShouldThrow>());
 
-  // When "receiver" is not passed, it defaults to "holder".
+  // When "receiver" is not passed, it defaults to "lookup_start_object".
   V8_EXPORT_PRIVATE V8_WARN_UNUSED_RESULT static MaybeHandle<Object>
-  GetObjectProperty(Isolate* isolate, Handle<Object> holder, Handle<Object> key,
+  GetObjectProperty(Isolate* isolate, Handle<Object> lookup_start_object,
+                    Handle<Object> key,
                     Handle<Object> receiver = Handle<Object>(),
                     bool* is_found = nullptr);
 
@@ -862,6 +868,8 @@ enum class OptimizationStatus {
   kLiteMode = 1 << 12,
   kMarkedForDeoptimization = 1 << 13,
   kBaseline = 1 << 14,
+  kTopmostFrameIsInterpreted = 1 << 15,
+  kTopmostFrameIsBaseline = 1 << 16,
 };
 
 }  // namespace internal
diff --git a/chromium/v8/src/sanitizer/asan.h b/chromium/v8/src/sanitizer/asan.h
deleted file mode 100644
index 0381e5a4c48..00000000000
--- a/chromium/v8/src/sanitizer/asan.h
+++ /dev/null
@@ -1,28 +0,0 @@
-// Copyright 2018 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// AddressSanitizer support.
-
-#ifndef V8_SANITIZER_ASAN_H_
-#define V8_SANITIZER_ASAN_H_
-
-#include "src/base/macros.h"
-#include "src/common/globals.h"
-
-#ifdef V8_USE_ADDRESS_SANITIZER
-
-#include <sanitizer/asan_interface.h>
-
-#else  // !V8_USE_ADDRESS_SANITIZER
-
-#define ASAN_POISON_MEMORY_REGION(start, size)                          \
-  static_assert(std::is_pointer<decltype(start)>::value &&              \
-                    std::is_convertible<decltype(size), size_t>::value, \
-                "static type violation")
-#define ASAN_UNPOISON_MEMORY_REGION(start, size) \
-  ASAN_POISON_MEMORY_REGION(start, size)
-
-#endif  // V8_USE_ADDRESS_SANITIZER
-
-#endif  // V8_SANITIZER_ASAN_H_
diff --git a/chromium/v8/src/sanitizer/msan.h b/chromium/v8/src/sanitizer/msan.h
deleted file mode 100644
index 01e774e7e41..00000000000
--- a/chromium/v8/src/sanitizer/msan.h
+++ /dev/null
@@ -1,36 +0,0 @@
-// Copyright 2013 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// MemorySanitizer support.
-
-#ifndef V8_SANITIZER_MSAN_H_
-#define V8_SANITIZER_MSAN_H_
-
-#include "src/base/macros.h"
-#include "src/common/globals.h"
-
-#ifdef V8_USE_MEMORY_SANITIZER
-
-#include <sanitizer/msan_interface.h>
-
-// Marks a memory range as uninitialized, as if it was allocated here.
-#define MSAN_ALLOCATED_UNINITIALIZED_MEMORY(p, s) \
-  __msan_allocated_memory(reinterpret_cast<const void*>(p), (s))
-// Marks a memory range as initialized.
-#define MSAN_MEMORY_IS_INITIALIZED(p, s) \
-  __msan_unpoison(reinterpret_cast<const void*>(p), (s))
-
-#else  // !V8_USE_MEMORY_SANITIZER
-
-#define MSAN_ALLOCATED_UNINITIALIZED_MEMORY(p, s)                            \
-  static_assert((std::is_pointer<decltype(p)>::value ||                      \
-                 std::is_same<v8::internal::Address, decltype(p)>::value) && \
-                    std::is_convertible<decltype(s), size_t>::value,         \
-                "static type violation")
-#define MSAN_MEMORY_IS_INITIALIZED(p, s) \
-  MSAN_ALLOCATED_UNINITIALIZED_MEMORY(p, s)
-
-#endif  // V8_USE_MEMORY_SANITIZER
-
-#endif  // V8_SANITIZER_MSAN_H_
diff --git a/chromium/v8/src/sanitizer/tsan.h b/chromium/v8/src/sanitizer/tsan.h
deleted file mode 100644
index 0013b91bfc7..00000000000
--- a/chromium/v8/src/sanitizer/tsan.h
+++ /dev/null
@@ -1,47 +0,0 @@
-// Copyright 2017 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef V8_SANITIZER_TSAN_H_
-#define V8_SANITIZER_TSAN_H_
-
-namespace v8 {
-namespace base {
-
-// This file contains annotations for ThreadSanitizer (TSan), a race detector.
-// See
-// https://llvm.org/svn/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_interface_ann.cc
-
-#if THREAD_SANITIZER
-
-#define TSAN_ANNOTATE_IGNORE_READS_BEGIN \
-  v8::base::AnnotateIgnoreReadsBegin(__FILE__, __LINE__)
-#define TSAN_ANNOTATE_IGNORE_READS_END \
-  v8::base::AnnotateIgnoreReadsEnd(__FILE__, __LINE__)
-#define TSAN_ANNOTATE_IGNORE_WRITES_BEGIN \
-  v8::base::AnnotateIgnoreWritesBegin(__FILE__, __LINE__)
-#define TSAN_ANNOTATE_IGNORE_WRITES_END \
-  v8::base::AnnotateIgnoreWritesEnd(__FILE__, __LINE__)
-
-extern "C" {
-
-void AnnotateIgnoreReadsBegin(const char* file, int line);
-void AnnotateIgnoreReadsEnd(const char* file, int line);
-void AnnotateIgnoreWritesBegin(const char* file, int line);
-void AnnotateIgnoreWritesEnd(const char* file, int line);
-
-}  // extern "C"
-
-#else
-
-#define TSAN_ANNOTATE_IGNORE_READS_BEGIN ((void)0)
-#define TSAN_ANNOTATE_IGNORE_READS_END ((void)0)
-#define TSAN_ANNOTATE_IGNORE_WRITES_BEGIN ((void)0)
-#define TSAN_ANNOTATE_IGNORE_WRITES_END ((void)0)
-
-#endif
-
-}  // namespace base
-}  // namespace v8
-
-#endif  // V8_SANITIZER_TSAN_H_
diff --git a/chromium/v8/src/snapshot/code-serializer.cc b/chromium/v8/src/snapshot/code-serializer.cc
index a4641baabf2..3725b267f57 100644
--- a/chromium/v8/src/snapshot/code-serializer.cc
+++ b/chromium/v8/src/snapshot/code-serializer.cc
@@ -44,8 +44,7 @@ ScriptCompiler::CachedData* CodeSerializer::Serialize(
   Isolate* isolate = info->GetIsolate();
   TRACE_EVENT_CALL_STATS_SCOPED(isolate, "v8", "V8.Execute");
   HistogramTimerScope histogram_timer(isolate->counters()->compile_serialize());
-  RuntimeCallTimerScope runtimeTimer(isolate,
-                                     RuntimeCallCounterId::kCompileSerialize);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kCompileSerialize);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.CompileSerialize");
 
   base::ElapsedTimer timer;
diff --git a/chromium/v8/src/snapshot/context-deserializer.cc b/chromium/v8/src/snapshot/context-deserializer.cc
index 04756b5ffe8..ad109baccaf 100644
--- a/chromium/v8/src/snapshot/context-deserializer.cc
+++ b/chromium/v8/src/snapshot/context-deserializer.cc
@@ -62,9 +62,11 @@ void ContextDeserializer::SetupOffHeapArrayBufferBackingStores() {
     uint32_t store_index = buffer->GetBackingStoreRefForDeserialization();
     auto bs = backing_store(store_index);
     buffer->AllocateExternalPointerEntries(isolate());
+    // TODO(v8:11111): Support RAB / GSAB.
+    CHECK(!buffer->is_resizable());
     SharedFlag shared =
         bs && bs->is_shared() ? SharedFlag::kShared : SharedFlag::kNotShared;
-    buffer->Setup(shared, bs);
+    buffer->Setup(shared, ResizableFlag::kNotResizable, bs);
   }
 }
 
diff --git a/chromium/v8/src/snapshot/deserializer.cc b/chromium/v8/src/snapshot/deserializer.cc
index ecfa889f1e3..7756580c836 100644
--- a/chromium/v8/src/snapshot/deserializer.cc
+++ b/chromium/v8/src/snapshot/deserializer.cc
@@ -464,6 +464,9 @@ void Deserializer::PostProcessNewObject(Handle<Map> map, Handle<HeapObject> obj,
     DCHECK(InstanceTypeChecker::IsStrongDescriptorArray(instance_type));
     Handle<DescriptorArray> descriptors = Handle<DescriptorArray>::cast(obj);
     new_descriptor_arrays_.push_back(descriptors);
+  } else if (InstanceTypeChecker::IsNativeContext(instance_type)) {
+    Handle<NativeContext> context = Handle<NativeContext>::cast(obj);
+    context->AllocateExternalPointerEntries(isolate());
   }
 
   // Check alignment.
diff --git a/chromium/v8/src/snapshot/embedded/embedded-data.cc b/chromium/v8/src/snapshot/embedded/embedded-data.cc
index 2a0549cfbb7..fb3883a410d 100644
--- a/chromium/v8/src/snapshot/embedded/embedded-data.cc
+++ b/chromium/v8/src/snapshot/embedded/embedded-data.cc
@@ -6,6 +6,7 @@
 
 #include "src/codegen/assembler-inl.h"
 #include "src/codegen/callable.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/objects/objects-inl.h"
 #include "src/snapshot/snapshot-utils.h"
 #include "src/snapshot/snapshot.h"
@@ -137,6 +138,9 @@ void InstructionStream::CreateOffHeapInstructionStream(Isolate* isolate,
   // in the binary) and what we are currently setting up here (where the blob is
   // on the native heap).
   std::memcpy(allocated_code_bytes, d.code(), d.code_size());
+  if (FLAG_experimental_flush_embedded_blob_icache) {
+    FlushInstructionCache(allocated_code_bytes, d.code_size());
+  }
   CHECK(SetPermissions(page_allocator, allocated_code_bytes,
                        allocation_code_size, PageAllocator::kReadExecute));
 
@@ -184,14 +188,15 @@ bool BuiltinAliasesOffHeapTrampolineRegister(Isolate* isolate, Code code) {
       return false;
   }
 
+  if (CallInterfaceDescriptor::ContextRegister() ==
+      kOffHeapTrampolineRegister) {
+    return true;
+  }
+
   Callable callable = Builtins::CallableFor(
       isolate, static_cast<Builtins::Name>(code.builtin_index()));
   CallInterfaceDescriptor descriptor = callable.descriptor();
 
-  if (descriptor.ContextRegister() == kOffHeapTrampolineRegister) {
-    return true;
-  }
-
   for (int i = 0; i < descriptor.GetRegisterParameterCount(); i++) {
     Register reg = descriptor.GetRegisterParameter(i);
     if (reg == kOffHeapTrampolineRegister) return true;
@@ -213,7 +218,8 @@ void FinalizeEmbeddedCodeTargets(Isolate* isolate, EmbeddedData* blob) {
 
 #if defined(V8_TARGET_ARCH_X64) || defined(V8_TARGET_ARCH_ARM64) || \
     defined(V8_TARGET_ARCH_ARM) || defined(V8_TARGET_ARCH_MIPS) ||  \
-    defined(V8_TARGET_ARCH_IA32) || defined(V8_TARGET_ARCH_S390)
+    defined(V8_TARGET_ARCH_IA32) || defined(V8_TARGET_ARCH_S390) || \
+    defined(V8_TARGET_ARCH_RISCV64)
     // On these platforms we emit relative builtin-to-builtin
     // jumps for isolate independent builtins in the snapshot. This fixes up the
     // relative jumps to the right offsets in the snapshot.
@@ -453,10 +459,9 @@ void EmbeddedData::PrintStatistics() const {
   const int k99th = kCount * 0.99;
 
   PrintF("EmbeddedData:\n");
-  PrintF("  Total size:                         %d\n",
+  PrintF("  Total size:                  %d\n",
          static_cast<int>(code_size() + data_size()));
-  PrintF("  Data size:                      %d\n",
-         static_cast<int>(data_size()));
+  PrintF("  Data size:                   %d\n", static_cast<int>(data_size()));
   PrintF("  Code size:                   %d\n", static_cast<int>(code_size()));
   PrintF("  Instruction size (50th percentile): %d\n", sizes[k50th]);
   PrintF("  Instruction size (75th percentile): %d\n", sizes[k75th]);
diff --git a/chromium/v8/src/snapshot/embedded/embedded-data.h b/chromium/v8/src/snapshot/embedded/embedded-data.h
index 6518c38d025..12f524d154b 100644
--- a/chromium/v8/src/snapshot/embedded/embedded-data.h
+++ b/chromium/v8/src/snapshot/embedded/embedded-data.h
@@ -9,6 +9,7 @@
 #include "src/builtins/builtins.h"
 #include "src/common/globals.h"
 #include "src/execution/isolate.h"
+#include "src/heap/code-range.h"
 
 namespace v8 {
 namespace internal {
@@ -62,6 +63,13 @@ class EmbeddedData final {
         isolate->embedded_blob_data(), isolate->embedded_blob_data_size());
   }
 
+  static EmbeddedData FromBlob(CodeRange* code_range) {
+    return EmbeddedData(code_range->embedded_blob_code_copy(),
+                        Isolate::CurrentEmbeddedBlobCodeSize(),
+                        Isolate::CurrentEmbeddedBlobData(),
+                        Isolate::CurrentEmbeddedBlobDataSize());
+  }
+
   const uint8_t* code() const { return code_; }
   uint32_t code_size() const { return code_size_; }
   const uint8_t* data() const { return data_; }
diff --git a/chromium/v8/src/snapshot/mksnapshot.cc b/chromium/v8/src/snapshot/mksnapshot.cc
index 4cccc8d1735..9a1e988bf86 100644
--- a/chromium/v8/src/snapshot/mksnapshot.cc
+++ b/chromium/v8/src/snapshot/mksnapshot.cc
@@ -11,10 +11,10 @@
 #include "include/libplatform/libplatform.h"
 #include "src/base/platform/platform.h"
 #include "src/base/platform/wrappers.h"
+#include "src/base/sanitizer/msan.h"
 #include "src/codegen/assembler-arch.h"
 #include "src/codegen/source-position-table.h"
 #include "src/flags/flags.h"
-#include "src/sanitizer/msan.h"
 #include "src/snapshot/context-serializer.h"
 #include "src/snapshot/embedded/embedded-file-writer.h"
 #include "src/snapshot/snapshot.h"
@@ -155,7 +155,7 @@ v8::StartupData CreateSnapshotDataBlob(v8::Isolate* isolate,
       isolate);
 
   if (i::FLAG_profile_deserialization) {
-    i::PrintF("Creating snapshot took %0.3f ms\n",
+    i::PrintF("[Creating snapshot took %0.3f ms]\n",
               timer.Elapsed().InMillisecondsF());
   }
 
diff --git a/chromium/v8/src/snapshot/object-deserializer.cc b/chromium/v8/src/snapshot/object-deserializer.cc
index 929996ee106..d5ce8cc6e93 100644
--- a/chromium/v8/src/snapshot/object-deserializer.cc
+++ b/chromium/v8/src/snapshot/object-deserializer.cc
@@ -66,7 +66,9 @@ void ObjectDeserializer::CommitPostProcessedObjects() {
     auto bs = backing_store(store_index);
     SharedFlag shared =
         bs && bs->is_shared() ? SharedFlag::kShared : SharedFlag::kNotShared;
-    buffer->Setup(shared, bs);
+    // TODO(v8:11111): Support RAB / GSAB.
+    CHECK(!bs || !bs->is_resizable());
+    buffer->Setup(shared, ResizableFlag::kNotResizable, bs);
   }
 
   for (Handle<Script> script : new_scripts()) {
diff --git a/chromium/v8/src/snapshot/read-only-serializer.cc b/chromium/v8/src/snapshot/read-only-serializer.cc
index 06c5094782c..3dc5af0b0d7 100644
--- a/chromium/v8/src/snapshot/read-only-serializer.cc
+++ b/chromium/v8/src/snapshot/read-only-serializer.cc
@@ -74,6 +74,10 @@ void ReadOnlySerializer::SerializeReadOnlyRoots() {
                 isolate()->handle_scope_implementer()->blocks()->empty());
 
   ReadOnlyRoots(isolate()).Iterate(this);
+
+  if (reconstruct_read_only_object_cache_for_testing()) {
+    ReconstructReadOnlyObjectCacheForTesting();
+  }
 }
 
 void ReadOnlySerializer::FinalizeSerialization() {
@@ -129,5 +133,18 @@ bool ReadOnlySerializer::SerializeUsingReadOnlyObjectCache(
   return true;
 }
 
+void ReadOnlySerializer::ReconstructReadOnlyObjectCacheForTesting() {
+  ReadOnlyHeap* ro_heap = isolate()->read_only_heap();
+  DCHECK(ro_heap->read_only_object_cache_is_initialized());
+  for (size_t i = 0, size = ro_heap->read_only_object_cache_size(); i < size;
+       i++) {
+    Handle<HeapObject> obj(
+        HeapObject::cast(ro_heap->cached_read_only_object(i)), isolate());
+    int cache_index = SerializeInObjectCache(obj);
+    USE(cache_index);
+    DCHECK_EQ(cache_index, i);
+  }
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/snapshot/read-only-serializer.h b/chromium/v8/src/snapshot/read-only-serializer.h
index fd88b9f7b65..7f9482f3b9a 100644
--- a/chromium/v8/src/snapshot/read-only-serializer.h
+++ b/chromium/v8/src/snapshot/read-only-serializer.h
@@ -37,6 +37,8 @@ class V8_EXPORT_PRIVATE ReadOnlySerializer : public RootsSerializer {
                                          Handle<HeapObject> obj);
 
  private:
+  void ReconstructReadOnlyObjectCacheForTesting();
+
   void SerializeObjectImpl(Handle<HeapObject> o) override;
   bool MustBeDeferred(HeapObject object) override;
 
diff --git a/chromium/v8/src/snapshot/serializer-deserializer.h b/chromium/v8/src/snapshot/serializer-deserializer.h
index 0e156f75a09..82f34001065 100644
--- a/chromium/v8/src/snapshot/serializer-deserializer.h
+++ b/chromium/v8/src/snapshot/serializer-deserializer.h
@@ -187,14 +187,13 @@ class SerializerDeserializer : public RootVisitor {
     }
 
     static constexpr byte Encode(TValue value) {
-      CONSTEXPR_DCHECK(IsEncodable(value));
+      DCHECK(IsEncodable(value));
       return static_cast<byte>(kBytecode + static_cast<int>(value) - kMinValue);
     }
 
     static constexpr TValue Decode(byte bytecode) {
-      CONSTEXPR_DCHECK(base::IsInRange(bytecode,
-                                       Encode(static_cast<TValue>(kMinValue)),
-                                       Encode(static_cast<TValue>(kMaxValue))));
+      DCHECK(base::IsInRange(bytecode, Encode(static_cast<TValue>(kMinValue)),
+                             Encode(static_cast<TValue>(kMaxValue))));
       return static_cast<TValue>(bytecode - kBytecode + kMinValue);
     }
   };
@@ -241,7 +240,7 @@ class SerializerDeserializer : public RootVisitor {
     }
 
     static constexpr int Encode(int repeat_count) {
-      CONSTEXPR_DCHECK(IsEncodable(repeat_count));
+      DCHECK(IsEncodable(repeat_count));
       return repeat_count - kFirstEncodableVariableRepeatCount;
     }
 
diff --git a/chromium/v8/src/snapshot/serializer.cc b/chromium/v8/src/snapshot/serializer.cc
index 89c5485d62c..7f7551316c1 100644
--- a/chromium/v8/src/snapshot/serializer.cc
+++ b/chromium/v8/src/snapshot/serializer.cc
@@ -98,9 +98,9 @@ void Serializer::OutputStatistics(const char* name) {
   }
   INSTANCE_TYPE_LIST(PRINT_INSTANCE_TYPE)
 #undef PRINT_INSTANCE_TYPE
+#endif  // OBJECT_PRINT
 
   PrintF("\n");
-#endif  // OBJECT_PRINT
 }
 
 void Serializer::SerializeDeferredObjects() {
diff --git a/chromium/v8/src/snapshot/serializer.h b/chromium/v8/src/snapshot/serializer.h
index 3743fa02c90..a1b17e4fd56 100644
--- a/chromium/v8/src/snapshot/serializer.h
+++ b/chromium/v8/src/snapshot/serializer.h
@@ -298,6 +298,10 @@ class Serializer : public SerializerDeserializer {
     return (flags_ & Snapshot::kAllowActiveIsolateForTesting) != 0;
   }
 
+  bool reconstruct_read_only_object_cache_for_testing() const {
+    return (flags_ & Snapshot::kReconstructReadOnlyObjectCacheForTesting) != 0;
+  }
+
  private:
   // A circular queue of hot objects. This is added to in the same order as in
   // Deserializer::HotObjectsList, but this stores the objects as an array of
diff --git a/chromium/v8/src/snapshot/snapshot-utils.cc b/chromium/v8/src/snapshot/snapshot-utils.cc
index eb2372372c9..df53dfe751e 100644
--- a/chromium/v8/src/snapshot/snapshot-utils.cc
+++ b/chromium/v8/src/snapshot/snapshot-utils.cc
@@ -4,7 +4,7 @@
 
 #include "src/snapshot/snapshot-utils.h"
 
-#include "src/sanitizer/msan.h"
+#include "src/base/sanitizer/msan.h"
 #include "third_party/zlib/zlib.h"
 
 namespace v8 {
diff --git a/chromium/v8/src/snapshot/snapshot.cc b/chromium/v8/src/snapshot/snapshot.cc
index b78e6a70d6e..3b4db28447b 100644
--- a/chromium/v8/src/snapshot/snapshot.cc
+++ b/chromium/v8/src/snapshot/snapshot.cc
@@ -144,8 +144,7 @@ bool Snapshot::VersionIsValid(const v8::StartupData* data) {
 
 bool Snapshot::Initialize(Isolate* isolate) {
   if (!isolate->snapshot_available()) return false;
-  RuntimeCallTimerScope rcs_timer(isolate,
-                                  RuntimeCallCounterId::kDeserializeIsolate);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kDeserializeIsolate);
   base::ElapsedTimer timer;
   if (FLAG_profile_deserialization) timer.Start();
 
@@ -173,8 +172,7 @@ MaybeHandle<Context> Snapshot::NewContextFromSnapshot(
     Isolate* isolate, Handle<JSGlobalProxy> global_proxy, size_t context_index,
     v8::DeserializeEmbedderFieldsCallback embedder_fields_deserializer) {
   if (!isolate->snapshot_available()) return Handle<Context>();
-  RuntimeCallTimerScope rcs_timer(isolate,
-                                  RuntimeCallCounterId::kDeserializeContext);
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kDeserializeContext);
   base::ElapsedTimer timer;
   if (FLAG_profile_deserialization) timer.Start();
 
@@ -288,7 +286,10 @@ void Snapshot::SerializeDeserializeAndVerifyForTesting(
 
     Snapshot::SerializerFlags flags(
         Snapshot::kAllowUnknownExternalReferencesForTesting |
-        Snapshot::kAllowActiveIsolateForTesting);
+        Snapshot::kAllowActiveIsolateForTesting |
+        (ReadOnlyHeap::IsReadOnlySpaceShared()
+             ? Snapshot::kReconstructReadOnlyObjectCacheForTesting
+             : 0));
     serialized_data = Snapshot::Create(isolate, *default_context, no_gc, flags);
     auto_delete_serialized_data.reset(serialized_data.data);
   }
@@ -360,7 +361,7 @@ v8::StartupData Snapshot::Create(
     context_serializer.Serialize(&contexts->at(i), no_gc);
     can_be_rehashed = can_be_rehashed && context_serializer.can_be_rehashed();
     context_snapshots.push_back(new SnapshotData(&context_serializer));
-    if (FLAG_profile_deserialization) {
+    if (FLAG_serialization_statistics) {
       context_allocation_sizes.push_back(
           context_serializer.TotalAllocationSize());
     }
@@ -374,15 +375,19 @@ v8::StartupData Snapshot::Create(
   read_only_serializer.FinalizeSerialization();
   can_be_rehashed = can_be_rehashed && read_only_serializer.can_be_rehashed();
 
-  if (FLAG_profile_deserialization) {
+  if (FLAG_serialization_statistics) {
     // These prints should match the regexp in test/memory/Memory.json
+    DCHECK_NE(read_only_serializer.TotalAllocationSize(), 0);
+    DCHECK_NE(startup_serializer.TotalAllocationSize(), 0);
     PrintF("Deserialization will allocate:\n");
     PrintF("%10d bytes per isolate\n",
            read_only_serializer.TotalAllocationSize() +
                startup_serializer.TotalAllocationSize());
     for (int i = 0; i < num_contexts; i++) {
+      DCHECK_NE(context_allocation_sizes[i], 0);
       PrintF("%10d bytes per context #%d\n", context_allocation_sizes[i], i);
     }
+    PrintF("\n");
   }
 
   SnapshotData read_only_snapshot(&read_only_serializer);
@@ -471,7 +476,7 @@ v8::StartupData SnapshotImpl::CreateSnapshotBlob(
   CopyBytes(data + payload_offset,
             reinterpret_cast<const char*>(startup_snapshot->RawData().begin()),
             payload_length);
-  if (FLAG_profile_deserialization) {
+  if (FLAG_serialization_statistics) {
     PrintF("Snapshot blob consists of:\n%10d bytes for startup\n",
            payload_length);
   }
@@ -485,7 +490,7 @@ v8::StartupData SnapshotImpl::CreateSnapshotBlob(
       data + payload_offset,
       reinterpret_cast<const char*>(read_only_snapshot->RawData().begin()),
       payload_length);
-  if (FLAG_profile_deserialization) {
+  if (FLAG_serialization_statistics) {
     PrintF("%10d bytes for read-only\n", payload_length);
   }
   payload_offset += payload_length;
@@ -500,11 +505,12 @@ v8::StartupData SnapshotImpl::CreateSnapshotBlob(
         data + payload_offset,
         reinterpret_cast<const char*>(context_snapshot->RawData().begin()),
         payload_length);
-    if (FLAG_profile_deserialization) {
+    if (FLAG_serialization_statistics) {
       PrintF("%10d bytes for context #%d\n", payload_length, i);
     }
     payload_offset += payload_length;
   }
+  if (FLAG_serialization_statistics) PrintF("\n");
 
   DCHECK_EQ(total_length, payload_offset);
   v8::StartupData result = {data, static_cast<int>(total_length)};
diff --git a/chromium/v8/src/snapshot/snapshot.h b/chromium/v8/src/snapshot/snapshot.h
index 0e510f0096f..2f16eee6d58 100644
--- a/chromium/v8/src/snapshot/snapshot.h
+++ b/chromium/v8/src/snapshot/snapshot.h
@@ -36,6 +36,15 @@ class Snapshot : public AllStatic {
     // after deserialization.
     // If unset, we assert that these previously mentioned areas are empty.
     kAllowActiveIsolateForTesting = 1 << 1,
+    // If set, the ReadOnlySerializer reconstructs the read-only object cache
+    // from the existing ReadOnlyHeap's read-only object cache so the same
+    // mapping is used.  This mode is used for testing deserialization of a
+    // snapshot from a live isolate that's using a shared
+    // ReadOnlyHeap. Otherwise during deserialization the indices will mismatch,
+    // causing deserialization crashes when e.g. types mismatch.
+    // If unset, the read-only object cache is populated as read-only objects
+    // are serialized.
+    kReconstructReadOnlyObjectCacheForTesting = 1 << 2,
   };
   using SerializerFlags = base::Flags<SerializerFlag>;
   V8_EXPORT_PRIVATE static constexpr SerializerFlags kDefaultSerializerFlags =
diff --git a/chromium/v8/src/strings/unicode.cc b/chromium/v8/src/strings/unicode.cc
index 21faccd0b42..a74e700ebd4 100644
--- a/chromium/v8/src/strings/unicode.cc
+++ b/chromium/v8/src/strings/unicode.cc
@@ -238,160 +238,112 @@ bool Uppercase::Is(uchar c) { return static_cast<bool>(u_isupper(c)); }
 #else
 static const uint16_t kUppercaseTable0Size = 455;
 static const int32_t kUppercaseTable0[455] = {
-    1073741889, 90,         1073742016, 214,
-    1073742040, 222,        256,        258,  // NOLINT
-    260,        262,        264,        266,
-    268,        270,        272,        274,  // NOLINT
-    276,        278,        280,        282,
-    284,        286,        288,        290,  // NOLINT
-    292,        294,        296,        298,
-    300,        302,        304,        306,  // NOLINT
-    308,        310,        313,        315,
-    317,        319,        321,        323,  // NOLINT
-    325,        327,        330,        332,
-    334,        336,        338,        340,  // NOLINT
-    342,        344,        346,        348,
-    350,        352,        354,        356,  // NOLINT
-    358,        360,        362,        364,
-    366,        368,        370,        372,  // NOLINT
-    374,        1073742200, 377,        379,
-    381,        1073742209, 386,        388,  // NOLINT
-    1073742214, 391,        1073742217, 395,
-    1073742222, 401,        1073742227, 404,  // NOLINT
-    1073742230, 408,        1073742236, 413,
-    1073742239, 416,        418,        420,  // NOLINT
-    1073742246, 423,        425,        428,
-    1073742254, 431,        1073742257, 435,  // NOLINT
-    437,        1073742263, 440,        444,
-    452,        455,        458,        461,  // NOLINT
-    463,        465,        467,        469,
-    471,        473,        475,        478,  // NOLINT
-    480,        482,        484,        486,
-    488,        490,        492,        494,  // NOLINT
-    497,        500,        1073742326, 504,
-    506,        508,        510,        512,  // NOLINT
-    514,        516,        518,        520,
-    522,        524,        526,        528,  // NOLINT
-    530,        532,        534,        536,
-    538,        540,        542,        544,  // NOLINT
-    546,        548,        550,        552,
-    554,        556,        558,        560,  // NOLINT
-    562,        1073742394, 571,        1073742397,
-    574,        577,        1073742403, 582,  // NOLINT
-    584,        586,        588,        590,
-    880,        882,        886,        895,  // NOLINT
-    902,        1073742728, 906,        908,
-    1073742734, 911,        1073742737, 929,  // NOLINT
-    1073742755, 939,        975,        1073742802,
-    980,        984,        986,        988,  // NOLINT
-    990,        992,        994,        996,
-    998,        1000,       1002,       1004,  // NOLINT
-    1006,       1012,       1015,       1073742841,
-    1018,       1073742845, 1071,       1120,  // NOLINT
-    1122,       1124,       1126,       1128,
-    1130,       1132,       1134,       1136,  // NOLINT
-    1138,       1140,       1142,       1144,
-    1146,       1148,       1150,       1152,  // NOLINT
-    1162,       1164,       1166,       1168,
-    1170,       1172,       1174,       1176,  // NOLINT
-    1178,       1180,       1182,       1184,
-    1186,       1188,       1190,       1192,  // NOLINT
-    1194,       1196,       1198,       1200,
-    1202,       1204,       1206,       1208,  // NOLINT
-    1210,       1212,       1214,       1073743040,
-    1217,       1219,       1221,       1223,  // NOLINT
-    1225,       1227,       1229,       1232,
-    1234,       1236,       1238,       1240,  // NOLINT
-    1242,       1244,       1246,       1248,
-    1250,       1252,       1254,       1256,  // NOLINT
-    1258,       1260,       1262,       1264,
-    1266,       1268,       1270,       1272,  // NOLINT
-    1274,       1276,       1278,       1280,
-    1282,       1284,       1286,       1288,  // NOLINT
-    1290,       1292,       1294,       1296,
-    1298,       1300,       1302,       1304,  // NOLINT
-    1306,       1308,       1310,       1312,
-    1314,       1316,       1318,       1320,  // NOLINT
-    1322,       1324,       1326,       1073743153,
-    1366,       1073746080, 4293,       4295,  // NOLINT
-    4301,       7680,       7682,       7684,
-    7686,       7688,       7690,       7692,  // NOLINT
-    7694,       7696,       7698,       7700,
-    7702,       7704,       7706,       7708,  // NOLINT
-    7710,       7712,       7714,       7716,
-    7718,       7720,       7722,       7724,  // NOLINT
-    7726,       7728,       7730,       7732,
-    7734,       7736,       7738,       7740,  // NOLINT
-    7742,       7744,       7746,       7748,
-    7750,       7752,       7754,       7756,  // NOLINT
-    7758,       7760,       7762,       7764,
-    7766,       7768,       7770,       7772,  // NOLINT
-    7774,       7776,       7778,       7780,
-    7782,       7784,       7786,       7788,  // NOLINT
-    7790,       7792,       7794,       7796,
-    7798,       7800,       7802,       7804,  // NOLINT
-    7806,       7808,       7810,       7812,
-    7814,       7816,       7818,       7820,  // NOLINT
-    7822,       7824,       7826,       7828,
-    7838,       7840,       7842,       7844,  // NOLINT
-    7846,       7848,       7850,       7852,
-    7854,       7856,       7858,       7860,  // NOLINT
-    7862,       7864,       7866,       7868,
-    7870,       7872,       7874,       7876,  // NOLINT
-    7878,       7880,       7882,       7884,
-    7886,       7888,       7890,       7892,  // NOLINT
-    7894,       7896,       7898,       7900,
-    7902,       7904,       7906,       7908,  // NOLINT
-    7910,       7912,       7914,       7916,
-    7918,       7920,       7922,       7924,  // NOLINT
-    7926,       7928,       7930,       7932,
-    7934,       1073749768, 7951,       1073749784,  // NOLINT
-    7965,       1073749800, 7983,       1073749816,
-    7999,       1073749832, 8013,       8025,  // NOLINT
-    8027,       8029,       8031,       1073749864,
-    8047,       1073749944, 8123,       1073749960,  // NOLINT
-    8139,       1073749976, 8155,       1073749992,
-    8172,       1073750008, 8187};  // NOLINT
+    1073741889, 90,         1073742016, 214,        1073742040, 222,
+    256,        258,        260,        262,        264,        266,
+    268,        270,        272,        274,        276,        278,
+    280,        282,        284,        286,        288,        290,
+    292,        294,        296,        298,        300,        302,
+    304,        306,        308,        310,        313,        315,
+    317,        319,        321,        323,        325,        327,
+    330,        332,        334,        336,        338,        340,
+    342,        344,        346,        348,        350,        352,
+    354,        356,        358,        360,        362,        364,
+    366,        368,        370,        372,        374,        1073742200,
+    377,        379,        381,        1073742209, 386,        388,
+    1073742214, 391,        1073742217, 395,        1073742222, 401,
+    1073742227, 404,        1073742230, 408,        1073742236, 413,
+    1073742239, 416,        418,        420,        1073742246, 423,
+    425,        428,        1073742254, 431,        1073742257, 435,
+    437,        1073742263, 440,        444,        452,        455,
+    458,        461,        463,        465,        467,        469,
+    471,        473,        475,        478,        480,        482,
+    484,        486,        488,        490,        492,        494,
+    497,        500,        1073742326, 504,        506,        508,
+    510,        512,        514,        516,        518,        520,
+    522,        524,        526,        528,        530,        532,
+    534,        536,        538,        540,        542,        544,
+    546,        548,        550,        552,        554,        556,
+    558,        560,        562,        1073742394, 571,        1073742397,
+    574,        577,        1073742403, 582,        584,        586,
+    588,        590,        880,        882,        886,        895,
+    902,        1073742728, 906,        908,        1073742734, 911,
+    1073742737, 929,        1073742755, 939,        975,        1073742802,
+    980,        984,        986,        988,        990,        992,
+    994,        996,        998,        1000,       1002,       1004,
+    1006,       1012,       1015,       1073742841, 1018,       1073742845,
+    1071,       1120,       1122,       1124,       1126,       1128,
+    1130,       1132,       1134,       1136,       1138,       1140,
+    1142,       1144,       1146,       1148,       1150,       1152,
+    1162,       1164,       1166,       1168,       1170,       1172,
+    1174,       1176,       1178,       1180,       1182,       1184,
+    1186,       1188,       1190,       1192,       1194,       1196,
+    1198,       1200,       1202,       1204,       1206,       1208,
+    1210,       1212,       1214,       1073743040, 1217,       1219,
+    1221,       1223,       1225,       1227,       1229,       1232,
+    1234,       1236,       1238,       1240,       1242,       1244,
+    1246,       1248,       1250,       1252,       1254,       1256,
+    1258,       1260,       1262,       1264,       1266,       1268,
+    1270,       1272,       1274,       1276,       1278,       1280,
+    1282,       1284,       1286,       1288,       1290,       1292,
+    1294,       1296,       1298,       1300,       1302,       1304,
+    1306,       1308,       1310,       1312,       1314,       1316,
+    1318,       1320,       1322,       1324,       1326,       1073743153,
+    1366,       1073746080, 4293,       4295,       4301,       7680,
+    7682,       7684,       7686,       7688,       7690,       7692,
+    7694,       7696,       7698,       7700,       7702,       7704,
+    7706,       7708,       7710,       7712,       7714,       7716,
+    7718,       7720,       7722,       7724,       7726,       7728,
+    7730,       7732,       7734,       7736,       7738,       7740,
+    7742,       7744,       7746,       7748,       7750,       7752,
+    7754,       7756,       7758,       7760,       7762,       7764,
+    7766,       7768,       7770,       7772,       7774,       7776,
+    7778,       7780,       7782,       7784,       7786,       7788,
+    7790,       7792,       7794,       7796,       7798,       7800,
+    7802,       7804,       7806,       7808,       7810,       7812,
+    7814,       7816,       7818,       7820,       7822,       7824,
+    7826,       7828,       7838,       7840,       7842,       7844,
+    7846,       7848,       7850,       7852,       7854,       7856,
+    7858,       7860,       7862,       7864,       7866,       7868,
+    7870,       7872,       7874,       7876,       7878,       7880,
+    7882,       7884,       7886,       7888,       7890,       7892,
+    7894,       7896,       7898,       7900,       7902,       7904,
+    7906,       7908,       7910,       7912,       7914,       7916,
+    7918,       7920,       7922,       7924,       7926,       7928,
+    7930,       7932,       7934,       1073749768, 7951,       1073749784,
+    7965,       1073749800, 7983,       1073749816, 7999,       1073749832,
+    8013,       8025,       8027,       8029,       8031,       1073749864,
+    8047,       1073749944, 8123,       1073749960, 8139,       1073749976,
+    8155,       1073749992, 8172,       1073750008, 8187};
 static const uint16_t kUppercaseTable1Size = 86;
 static const int32_t kUppercaseTable1[86] = {
-    258,        263,        1073742091, 269,  1073742096, 274,
-    277,        1073742105,  // NOLINT
-    285,        292,        294,        296,  1073742122, 301,
-    1073742128, 307,  // NOLINT
-    1073742142, 319,        325,        387,  1073744896, 3118,
-    3168,       1073744994,  // NOLINT
-    3172,       3175,       3177,       3179, 1073745005, 3184,
-    3186,       3189,  // NOLINT
-    1073745022, 3200,       3202,       3204, 3206,       3208,
-    3210,       3212,  // NOLINT
-    3214,       3216,       3218,       3220, 3222,       3224,
-    3226,       3228,  // NOLINT
-    3230,       3232,       3234,       3236, 3238,       3240,
-    3242,       3244,  // NOLINT
-    3246,       3248,       3250,       3252, 3254,       3256,
-    3258,       3260,  // NOLINT
-    3262,       3264,       3266,       3268, 3270,       3272,
-    3274,       3276,  // NOLINT
-    3278,       3280,       3282,       3284, 3286,       3288,
-    3290,       3292,                                             // NOLINT
-    3294,       3296,       3298,       3307, 3309,       3314};  // NOLINT
+    258,        263,  1073742091, 269,  1073742096, 274,        277,
+    1073742105, 285,  292,        294,  296,        1073742122, 301,
+    1073742128, 307,  1073742142, 319,  325,        387,        1073744896,
+    3118,       3168, 1073744994, 3172, 3175,       3177,       3179,
+    1073745005, 3184, 3186,       3189, 1073745022, 3200,       3202,
+    3204,       3206, 3208,       3210, 3212,       3214,       3216,
+    3218,       3220, 3222,       3224, 3226,       3228,       3230,
+    3232,       3234, 3236,       3238, 3240,       3242,       3244,
+    3246,       3248, 3250,       3252, 3254,       3256,       3258,
+    3260,       3262, 3264,       3266, 3268,       3270,       3272,
+    3274,       3276, 3278,       3280, 3282,       3284,       3286,
+    3288,       3290, 3292,       3294, 3296,       3298,       3307,
+    3309,       3314};
 static const uint16_t kUppercaseTable5Size = 101;
 static const int32_t kUppercaseTable5[101] = {
-    1600, 1602,       1604, 1606,       1608, 1610,       1612, 1614,  // NOLINT
-    1616, 1618,       1620, 1622,       1624, 1626,       1628, 1630,  // NOLINT
-    1632, 1634,       1636, 1638,       1640, 1642,       1644, 1664,  // NOLINT
-    1666, 1668,       1670, 1672,       1674, 1676,       1678, 1680,  // NOLINT
-    1682, 1684,       1686, 1688,       1690, 1826,       1828, 1830,  // NOLINT
-    1832, 1834,       1836, 1838,       1842, 1844,       1846, 1848,  // NOLINT
-    1850, 1852,       1854, 1856,       1858, 1860,       1862, 1864,  // NOLINT
-    1866, 1868,       1870, 1872,       1874, 1876,       1878, 1880,  // NOLINT
-    1882, 1884,       1886, 1888,       1890, 1892,       1894, 1896,  // NOLINT
-    1898, 1900,       1902, 1913,       1915, 1073743741, 1918, 1920,  // NOLINT
-    1922, 1924,       1926, 1931,       1933, 1936,       1938, 1942,  // NOLINT
-    1944, 1946,       1948, 1950,       1952, 1954,       1956, 1958,  // NOLINT
-    1960, 1073743786, 1965, 1073743792, 1969};                         // NOLINT
+    1600, 1602, 1604, 1606, 1608, 1610, 1612, 1614,       1616, 1618,
+    1620, 1622, 1624, 1626, 1628, 1630, 1632, 1634,       1636, 1638,
+    1640, 1642, 1644, 1664, 1666, 1668, 1670, 1672,       1674, 1676,
+    1678, 1680, 1682, 1684, 1686, 1688, 1690, 1826,       1828, 1830,
+    1832, 1834, 1836, 1838, 1842, 1844, 1846, 1848,       1850, 1852,
+    1854, 1856, 1858, 1860, 1862, 1864, 1866, 1868,       1870, 1872,
+    1874, 1876, 1878, 1880, 1882, 1884, 1886, 1888,       1890, 1892,
+    1894, 1896, 1898, 1900, 1902, 1913, 1915, 1073743741, 1918, 1920,
+    1922, 1924, 1926, 1931, 1933, 1936, 1938, 1942,       1944, 1946,
+    1948, 1950, 1952, 1954, 1956, 1958, 1960, 1073743786, 1965, 1073743792,
+    1969};
 static const uint16_t kUppercaseTable7Size = 2;
-static const int32_t kUppercaseTable7[2] = {1073749793, 7994};  // NOLINT
+static const int32_t kUppercaseTable7[2] = {1073749793, 7994};
 bool Uppercase::Is(uchar c) {
   int chunk_index = c >> 13;
   switch (chunk_index) {
@@ -415,189 +367,133 @@ bool Letter::Is(uchar c) { return static_cast<bool>(u_isalpha(c)); }
 #else
 static const uint16_t kLetterTable0Size = 431;
 static const int32_t kLetterTable0[431] = {
-    1073741889, 90,         1073741921, 122,
-    170,        181,        186,        1073742016,  // NOLINT
-    214,        1073742040, 246,        1073742072,
-    705,        1073742534, 721,        1073742560,  // NOLINT
-    740,        748,        750,        1073742704,
-    884,        1073742710, 887,        1073742714,  // NOLINT
-    893,        895,        902,        1073742728,
-    906,        908,        1073742734, 929,  // NOLINT
-    1073742755, 1013,       1073742839, 1153,
-    1073742986, 1327,       1073743153, 1366,  // NOLINT
-    1369,       1073743201, 1415,       1073743312,
-    1514,       1073743344, 1522,       1073743392,  // NOLINT
-    1610,       1073743470, 1647,       1073743473,
-    1747,       1749,       1073743589, 1766,  // NOLINT
-    1073743598, 1775,       1073743610, 1788,
-    1791,       1808,       1073743634, 1839,  // NOLINT
-    1073743693, 1957,       1969,       1073743818,
-    2026,       1073743860, 2037,       2042,  // NOLINT
-    1073743872, 2069,       2074,       2084,
-    2088,       1073743936, 2136,       1073744032,  // NOLINT
-    2226,       1073744132, 2361,       2365,
-    2384,       1073744216, 2401,       1073744241,  // NOLINT
-    2432,       1073744261, 2444,       1073744271,
-    2448,       1073744275, 2472,       1073744298,  // NOLINT
-    2480,       2482,       1073744310, 2489,
-    2493,       2510,       1073744348, 2525,  // NOLINT
-    1073744351, 2529,       1073744368, 2545,
-    1073744389, 2570,       1073744399, 2576,  // NOLINT
-    1073744403, 2600,       1073744426, 2608,
-    1073744434, 2611,       1073744437, 2614,  // NOLINT
-    1073744440, 2617,       1073744473, 2652,
-    2654,       1073744498, 2676,       1073744517,  // NOLINT
-    2701,       1073744527, 2705,       1073744531,
-    2728,       1073744554, 2736,       1073744562,  // NOLINT
-    2739,       1073744565, 2745,       2749,
-    2768,       1073744608, 2785,       1073744645,  // NOLINT
-    2828,       1073744655, 2832,       1073744659,
-    2856,       1073744682, 2864,       1073744690,  // NOLINT
-    2867,       1073744693, 2873,       2877,
-    1073744732, 2909,       1073744735, 2913,  // NOLINT
-    2929,       2947,       1073744773, 2954,
-    1073744782, 2960,       1073744786, 2965,  // NOLINT
-    1073744793, 2970,       2972,       1073744798,
-    2975,       1073744803, 2980,       1073744808,  // NOLINT
-    2986,       1073744814, 3001,       3024,
-    1073744901, 3084,       1073744910, 3088,  // NOLINT
-    1073744914, 3112,       1073744938, 3129,
-    3133,       1073744984, 3161,       1073744992,  // NOLINT
-    3169,       1073745029, 3212,       1073745038,
-    3216,       1073745042, 3240,       1073745066,  // NOLINT
-    3251,       1073745077, 3257,       3261,
-    3294,       1073745120, 3297,       1073745137,  // NOLINT
-    3314,       1073745157, 3340,       1073745166,
-    3344,       1073745170, 3386,       3389,  // NOLINT
-    3406,       1073745248, 3425,       1073745274,
-    3455,       1073745285, 3478,       1073745306,  // NOLINT
-    3505,       1073745331, 3515,       3517,
-    1073745344, 3526,       1073745409, 3632,  // NOLINT
-    1073745458, 3635,       1073745472, 3654,
-    1073745537, 3714,       3716,       1073745543,  // NOLINT
-    3720,       3722,       3725,       1073745556,
-    3735,       1073745561, 3743,       1073745569,  // NOLINT
-    3747,       3749,       3751,       1073745578,
-    3755,       1073745581, 3760,       1073745586,  // NOLINT
-    3763,       3773,       1073745600, 3780,
-    3782,       1073745628, 3807,       3840,  // NOLINT
-    1073745728, 3911,       1073745737, 3948,
-    1073745800, 3980,       1073745920, 4138,  // NOLINT
-    4159,       1073746000, 4181,       1073746010,
-    4189,       4193,       1073746021, 4198,  // NOLINT
-    1073746030, 4208,       1073746037, 4225,
-    4238,       1073746080, 4293,       4295,  // NOLINT
-    4301,       1073746128, 4346,       1073746172,
-    4680,       1073746506, 4685,       1073746512,  // NOLINT
-    4694,       4696,       1073746522, 4701,
-    1073746528, 4744,       1073746570, 4749,  // NOLINT
-    1073746576, 4784,       1073746610, 4789,
-    1073746616, 4798,       4800,       1073746626,  // NOLINT
-    4805,       1073746632, 4822,       1073746648,
-    4880,       1073746706, 4885,       1073746712,  // NOLINT
-    4954,       1073746816, 5007,       1073746848,
-    5108,       1073746945, 5740,       1073747567,  // NOLINT
-    5759,       1073747585, 5786,       1073747616,
-    5866,       1073747694, 5880,       1073747712,  // NOLINT
-    5900,       1073747726, 5905,       1073747744,
-    5937,       1073747776, 5969,       1073747808,  // NOLINT
-    5996,       1073747822, 6000,       1073747840,
-    6067,       6103,       6108,       1073748000,  // NOLINT
-    6263,       1073748096, 6312,       6314,
-    1073748144, 6389,       1073748224, 6430,  // NOLINT
-    1073748304, 6509,       1073748336, 6516,
-    1073748352, 6571,       1073748417, 6599,  // NOLINT
-    1073748480, 6678,       1073748512, 6740,
-    6823,       1073748741, 6963,       1073748805,  // NOLINT
-    6987,       1073748867, 7072,       1073748910,
-    7087,       1073748922, 7141,       1073748992,  // NOLINT
-    7203,       1073749069, 7247,       1073749082,
-    7293,       1073749225, 7404,       1073749230,  // NOLINT
-    7409,       1073749237, 7414,       1073749248,
-    7615,       1073749504, 7957,       1073749784,  // NOLINT
-    7965,       1073749792, 8005,       1073749832,
-    8013,       1073749840, 8023,       8025,  // NOLINT
-    8027,       8029,       1073749855, 8061,
-    1073749888, 8116,       1073749942, 8124,  // NOLINT
-    8126,       1073749954, 8132,       1073749958,
-    8140,       1073749968, 8147,       1073749974,  // NOLINT
-    8155,       1073749984, 8172,       1073750002,
-    8180,       1073750006, 8188};  // NOLINT
+    1073741889, 90,         1073741921, 122,        170,        181,
+    186,        1073742016, 214,        1073742040, 246,        1073742072,
+    705,        1073742534, 721,        1073742560, 740,        748,
+    750,        1073742704, 884,        1073742710, 887,        1073742714,
+    893,        895,        902,        1073742728, 906,        908,
+    1073742734, 929,        1073742755, 1013,       1073742839, 1153,
+    1073742986, 1327,       1073743153, 1366,       1369,       1073743201,
+    1415,       1073743312, 1514,       1073743344, 1522,       1073743392,
+    1610,       1073743470, 1647,       1073743473, 1747,       1749,
+    1073743589, 1766,       1073743598, 1775,       1073743610, 1788,
+    1791,       1808,       1073743634, 1839,       1073743693, 1957,
+    1969,       1073743818, 2026,       1073743860, 2037,       2042,
+    1073743872, 2069,       2074,       2084,       2088,       1073743936,
+    2136,       1073744032, 2226,       1073744132, 2361,       2365,
+    2384,       1073744216, 2401,       1073744241, 2432,       1073744261,
+    2444,       1073744271, 2448,       1073744275, 2472,       1073744298,
+    2480,       2482,       1073744310, 2489,       2493,       2510,
+    1073744348, 2525,       1073744351, 2529,       1073744368, 2545,
+    1073744389, 2570,       1073744399, 2576,       1073744403, 2600,
+    1073744426, 2608,       1073744434, 2611,       1073744437, 2614,
+    1073744440, 2617,       1073744473, 2652,       2654,       1073744498,
+    2676,       1073744517, 2701,       1073744527, 2705,       1073744531,
+    2728,       1073744554, 2736,       1073744562, 2739,       1073744565,
+    2745,       2749,       2768,       1073744608, 2785,       1073744645,
+    2828,       1073744655, 2832,       1073744659, 2856,       1073744682,
+    2864,       1073744690, 2867,       1073744693, 2873,       2877,
+    1073744732, 2909,       1073744735, 2913,       2929,       2947,
+    1073744773, 2954,       1073744782, 2960,       1073744786, 2965,
+    1073744793, 2970,       2972,       1073744798, 2975,       1073744803,
+    2980,       1073744808, 2986,       1073744814, 3001,       3024,
+    1073744901, 3084,       1073744910, 3088,       1073744914, 3112,
+    1073744938, 3129,       3133,       1073744984, 3161,       1073744992,
+    3169,       1073745029, 3212,       1073745038, 3216,       1073745042,
+    3240,       1073745066, 3251,       1073745077, 3257,       3261,
+    3294,       1073745120, 3297,       1073745137, 3314,       1073745157,
+    3340,       1073745166, 3344,       1073745170, 3386,       3389,
+    3406,       1073745248, 3425,       1073745274, 3455,       1073745285,
+    3478,       1073745306, 3505,       1073745331, 3515,       3517,
+    1073745344, 3526,       1073745409, 3632,       1073745458, 3635,
+    1073745472, 3654,       1073745537, 3714,       3716,       1073745543,
+    3720,       3722,       3725,       1073745556, 3735,       1073745561,
+    3743,       1073745569, 3747,       3749,       3751,       1073745578,
+    3755,       1073745581, 3760,       1073745586, 3763,       3773,
+    1073745600, 3780,       3782,       1073745628, 3807,       3840,
+    1073745728, 3911,       1073745737, 3948,       1073745800, 3980,
+    1073745920, 4138,       4159,       1073746000, 4181,       1073746010,
+    4189,       4193,       1073746021, 4198,       1073746030, 4208,
+    1073746037, 4225,       4238,       1073746080, 4293,       4295,
+    4301,       1073746128, 4346,       1073746172, 4680,       1073746506,
+    4685,       1073746512, 4694,       4696,       1073746522, 4701,
+    1073746528, 4744,       1073746570, 4749,       1073746576, 4784,
+    1073746610, 4789,       1073746616, 4798,       4800,       1073746626,
+    4805,       1073746632, 4822,       1073746648, 4880,       1073746706,
+    4885,       1073746712, 4954,       1073746816, 5007,       1073746848,
+    5108,       1073746945, 5740,       1073747567, 5759,       1073747585,
+    5786,       1073747616, 5866,       1073747694, 5880,       1073747712,
+    5900,       1073747726, 5905,       1073747744, 5937,       1073747776,
+    5969,       1073747808, 5996,       1073747822, 6000,       1073747840,
+    6067,       6103,       6108,       1073748000, 6263,       1073748096,
+    6312,       6314,       1073748144, 6389,       1073748224, 6430,
+    1073748304, 6509,       1073748336, 6516,       1073748352, 6571,
+    1073748417, 6599,       1073748480, 6678,       1073748512, 6740,
+    6823,       1073748741, 6963,       1073748805, 6987,       1073748867,
+    7072,       1073748910, 7087,       1073748922, 7141,       1073748992,
+    7203,       1073749069, 7247,       1073749082, 7293,       1073749225,
+    7404,       1073749230, 7409,       1073749237, 7414,       1073749248,
+    7615,       1073749504, 7957,       1073749784, 7965,       1073749792,
+    8005,       1073749832, 8013,       1073749840, 8023,       8025,
+    8027,       8029,       1073749855, 8061,       1073749888, 8116,
+    1073749942, 8124,       8126,       1073749954, 8132,       1073749958,
+    8140,       1073749968, 8147,       1073749974, 8155,       1073749984,
+    8172,       1073750002, 8180,       1073750006, 8188};
 static const uint16_t kLetterTable1Size = 87;
 static const int32_t kLetterTable1[87] = {
-    113,        127,        1073741968, 156,
-    258,        263,        1073742090, 275,  // NOLINT
-    277,        1073742105, 285,        292,
-    294,        296,        1073742122, 301,  // NOLINT
-    1073742127, 313,        1073742140, 319,
-    1073742149, 329,        334,        1073742176,  // NOLINT
-    392,        1073744896, 3118,       1073744944,
-    3166,       1073744992, 3300,       1073745131,  // NOLINT
-    3310,       1073745138, 3315,       1073745152,
-    3365,       3367,       3373,       1073745200,  // NOLINT
-    3431,       3439,       1073745280, 3478,
-    1073745312, 3494,       1073745320, 3502,  // NOLINT
-    1073745328, 3510,       1073745336, 3518,
-    1073745344, 3526,       1073745352, 3534,  // NOLINT
-    1073745360, 3542,       1073745368, 3550,
-    3631,       1073745925, 4103,       1073745953,  // NOLINT
-    4137,       1073745969, 4149,       1073745976,
-    4156,       1073745985, 4246,       1073746077,  // NOLINT
-    4255,       1073746081, 4346,       1073746172,
-    4351,       1073746181, 4397,       1073746225,  // NOLINT
-    4494,       1073746336, 4538,       1073746416,
-    4607,       1073746944, 8191};  // NOLINT
+    113,        127,        1073741968, 156,        258,        263,
+    1073742090, 275,        277,        1073742105, 285,        292,
+    294,        296,        1073742122, 301,        1073742127, 313,
+    1073742140, 319,        1073742149, 329,        334,        1073742176,
+    392,        1073744896, 3118,       1073744944, 3166,       1073744992,
+    3300,       1073745131, 3310,       1073745138, 3315,       1073745152,
+    3365,       3367,       3373,       1073745200, 3431,       3439,
+    1073745280, 3478,       1073745312, 3494,       1073745320, 3502,
+    1073745328, 3510,       1073745336, 3518,       1073745344, 3526,
+    1073745352, 3534,       1073745360, 3542,       1073745368, 3550,
+    3631,       1073745925, 4103,       1073745953, 4137,       1073745969,
+    4149,       1073745976, 4156,       1073745985, 4246,       1073746077,
+    4255,       1073746081, 4346,       1073746172, 4351,       1073746181,
+    4397,       1073746225, 4494,       1073746336, 4538,       1073746416,
+    4607,       1073746944, 8191};
 static const uint16_t kLetterTable2Size = 4;
-static const int32_t kLetterTable2[4] = {1073741824, 3509, 1073745408,
-                                         8191};  // NOLINT
+static const int32_t kLetterTable2[4] = {1073741824, 3509, 1073745408, 8191};
 static const uint16_t kLetterTable3Size = 2;
-static const int32_t kLetterTable3[2] = {1073741824, 8191};  // NOLINT
+static const int32_t kLetterTable3[2] = {1073741824, 8191};
 static const uint16_t kLetterTable4Size = 2;
-static const int32_t kLetterTable4[2] = {1073741824, 8140};  // NOLINT
+static const int32_t kLetterTable4[2] = {1073741824, 8140};
 static const uint16_t kLetterTable5Size = 100;
 static const int32_t kLetterTable5[100] = {
-    1073741824, 1164,       1073743056, 1277,
-    1073743104, 1548,       1073743376, 1567,  // NOLINT
-    1073743402, 1579,       1073743424, 1646,
-    1073743487, 1693,       1073743520, 1775,  // NOLINT
-    1073743639, 1823,       1073743650, 1928,
-    1073743755, 1934,       1073743760, 1965,  // NOLINT
-    1073743792, 1969,       1073743863, 2049,
-    1073743875, 2053,       1073743879, 2058,  // NOLINT
-    1073743884, 2082,       1073743936, 2163,
-    1073744002, 2227,       1073744114, 2295,  // NOLINT
-    2299,       1073744138, 2341,       1073744176,
-    2374,       1073744224, 2428,       1073744260,  // NOLINT
-    2482,       2511,       1073744352, 2532,
-    1073744358, 2543,       1073744378, 2558,  // NOLINT
-    1073744384, 2600,       1073744448, 2626,
-    1073744452, 2635,       1073744480, 2678,  // NOLINT
-    2682,       1073744510, 2735,       2737,
-    1073744565, 2742,       1073744569, 2749,  // NOLINT
-    2752,       2754,       1073744603, 2781,
-    1073744608, 2794,       1073744626, 2804,  // NOLINT
-    1073744641, 2822,       1073744649, 2830,
-    1073744657, 2838,       1073744672, 2854,  // NOLINT
-    1073744680, 2862,       1073744688, 2906,
-    1073744732, 2911,       1073744740, 2917,   // NOLINT
-    1073744832, 3042,       1073744896, 8191};  // NOLINT
+    1073741824, 1164,       1073743056, 1277,       1073743104, 1548,
+    1073743376, 1567,       1073743402, 1579,       1073743424, 1646,
+    1073743487, 1693,       1073743520, 1775,       1073743639, 1823,
+    1073743650, 1928,       1073743755, 1934,       1073743760, 1965,
+    1073743792, 1969,       1073743863, 2049,       1073743875, 2053,
+    1073743879, 2058,       1073743884, 2082,       1073743936, 2163,
+    1073744002, 2227,       1073744114, 2295,       2299,       1073744138,
+    2341,       1073744176, 2374,       1073744224, 2428,       1073744260,
+    2482,       2511,       1073744352, 2532,       1073744358, 2543,
+    1073744378, 2558,       1073744384, 2600,       1073744448, 2626,
+    1073744452, 2635,       1073744480, 2678,       2682,       1073744510,
+    2735,       2737,       1073744565, 2742,       1073744569, 2749,
+    2752,       2754,       1073744603, 2781,       1073744608, 2794,
+    1073744626, 2804,       1073744641, 2822,       1073744649, 2830,
+    1073744657, 2838,       1073744672, 2854,       1073744680, 2862,
+    1073744688, 2906,       1073744732, 2911,       1073744740, 2917,
+    1073744832, 3042,       1073744896, 8191};
 static const uint16_t kLetterTable6Size = 6;
-static const int32_t kLetterTable6[6] = {1073741824, 6051, 1073747888, 6086,
-                                         1073747915, 6139};  // NOLINT
+static const int32_t kLetterTable6[6] = {1073741824, 6051,       1073747888,
+                                         6086,       1073747915, 6139};
 static const uint16_t kLetterTable7Size = 48;
 static const int32_t kLetterTable7[48] = {
-    1073748224, 6765,       1073748592, 6873,
-    1073748736, 6918,       1073748755, 6935,  // NOLINT
-    6941,       1073748767, 6952,       1073748778,
-    6966,       1073748792, 6972,       6974,  // NOLINT
-    1073748800, 6977,       1073748803, 6980,
-    1073748806, 7089,       1073748947, 7485,  // NOLINT
-    1073749328, 7567,       1073749394, 7623,
-    1073749488, 7675,       1073749616, 7796,  // NOLINT
-    1073749622, 7932,       1073749793, 7994,
-    1073749825, 8026,       1073749862, 8126,  // NOLINT
-    1073749954, 8135,       1073749962, 8143,
-    1073749970, 8151,       1073749978, 8156};  // NOLINT
+    1073748224, 6765,       1073748592, 6873,       1073748736, 6918,
+    1073748755, 6935,       6941,       1073748767, 6952,       1073748778,
+    6966,       1073748792, 6972,       6974,       1073748800, 6977,
+    1073748803, 6980,       1073748806, 7089,       1073748947, 7485,
+    1073749328, 7567,       1073749394, 7623,       1073749488, 7675,
+    1073749616, 7796,       1073749622, 7932,       1073749793, 7994,
+    1073749825, 8026,       1073749862, 8126,       1073749954, 8135,
+    1073749962, 8143,       1073749970, 8151,       1073749978, 8156};
 bool Letter::Is(uchar c) {
   int chunk_index = c >> 13;
   switch (chunk_index) {
@@ -631,189 +527,133 @@ bool Letter::Is(uchar c) {
 
 static const uint16_t kID_StartTable0Size = 434;
 static const int32_t kID_StartTable0[434] = {
-    36,         1073741889, 90,         92,
-    95,         1073741921, 122,        170,  // NOLINT
-    181,        186,        1073742016, 214,
-    1073742040, 246,        1073742072, 705,  // NOLINT
-    1073742534, 721,        1073742560, 740,
-    748,        750,        1073742704, 884,  // NOLINT
-    1073742710, 887,        1073742714, 893,
-    895,        902,        1073742728, 906,  // NOLINT
-    908,        1073742734, 929,        1073742755,
-    1013,       1073742839, 1153,       1073742986,  // NOLINT
-    1327,       1073743153, 1366,       1369,
-    1073743201, 1415,       1073743312, 1514,  // NOLINT
-    1073743344, 1522,       1073743392, 1610,
-    1073743470, 1647,       1073743473, 1747,  // NOLINT
-    1749,       1073743589, 1766,       1073743598,
-    1775,       1073743610, 1788,       1791,  // NOLINT
-    1808,       1073743634, 1839,       1073743693,
-    1957,       1969,       1073743818, 2026,  // NOLINT
-    1073743860, 2037,       2042,       1073743872,
-    2069,       2074,       2084,       2088,  // NOLINT
-    1073743936, 2136,       1073744032, 2226,
-    1073744132, 2361,       2365,       2384,  // NOLINT
-    1073744216, 2401,       1073744241, 2432,
-    1073744261, 2444,       1073744271, 2448,  // NOLINT
-    1073744275, 2472,       1073744298, 2480,
-    2482,       1073744310, 2489,       2493,  // NOLINT
-    2510,       1073744348, 2525,       1073744351,
-    2529,       1073744368, 2545,       1073744389,  // NOLINT
-    2570,       1073744399, 2576,       1073744403,
-    2600,       1073744426, 2608,       1073744434,  // NOLINT
-    2611,       1073744437, 2614,       1073744440,
-    2617,       1073744473, 2652,       2654,  // NOLINT
-    1073744498, 2676,       1073744517, 2701,
-    1073744527, 2705,       1073744531, 2728,  // NOLINT
-    1073744554, 2736,       1073744562, 2739,
-    1073744565, 2745,       2749,       2768,  // NOLINT
-    1073744608, 2785,       1073744645, 2828,
-    1073744655, 2832,       1073744659, 2856,  // NOLINT
-    1073744682, 2864,       1073744690, 2867,
-    1073744693, 2873,       2877,       1073744732,  // NOLINT
-    2909,       1073744735, 2913,       2929,
-    2947,       1073744773, 2954,       1073744782,  // NOLINT
-    2960,       1073744786, 2965,       1073744793,
-    2970,       2972,       1073744798, 2975,  // NOLINT
-    1073744803, 2980,       1073744808, 2986,
-    1073744814, 3001,       3024,       1073744901,  // NOLINT
-    3084,       1073744910, 3088,       1073744914,
-    3112,       1073744938, 3129,       3133,  // NOLINT
-    1073744984, 3161,       1073744992, 3169,
-    1073745029, 3212,       1073745038, 3216,  // NOLINT
-    1073745042, 3240,       1073745066, 3251,
-    1073745077, 3257,       3261,       3294,  // NOLINT
-    1073745120, 3297,       1073745137, 3314,
-    1073745157, 3340,       1073745166, 3344,  // NOLINT
-    1073745170, 3386,       3389,       3406,
-    1073745248, 3425,       1073745274, 3455,  // NOLINT
-    1073745285, 3478,       1073745306, 3505,
-    1073745331, 3515,       3517,       1073745344,  // NOLINT
-    3526,       1073745409, 3632,       1073745458,
-    3635,       1073745472, 3654,       1073745537,  // NOLINT
-    3714,       3716,       1073745543, 3720,
-    3722,       3725,       1073745556, 3735,  // NOLINT
-    1073745561, 3743,       1073745569, 3747,
-    3749,       3751,       1073745578, 3755,  // NOLINT
-    1073745581, 3760,       1073745586, 3763,
-    3773,       1073745600, 3780,       3782,  // NOLINT
-    1073745628, 3807,       3840,       1073745728,
-    3911,       1073745737, 3948,       1073745800,  // NOLINT
-    3980,       1073745920, 4138,       4159,
-    1073746000, 4181,       1073746010, 4189,  // NOLINT
-    4193,       1073746021, 4198,       1073746030,
-    4208,       1073746037, 4225,       4238,  // NOLINT
-    1073746080, 4293,       4295,       4301,
-    1073746128, 4346,       1073746172, 4680,  // NOLINT
-    1073746506, 4685,       1073746512, 4694,
-    4696,       1073746522, 4701,       1073746528,  // NOLINT
-    4744,       1073746570, 4749,       1073746576,
-    4784,       1073746610, 4789,       1073746616,  // NOLINT
-    4798,       4800,       1073746626, 4805,
-    1073746632, 4822,       1073746648, 4880,  // NOLINT
-    1073746706, 4885,       1073746712, 4954,
-    1073746816, 5007,       1073746848, 5108,  // NOLINT
-    1073746945, 5740,       1073747567, 5759,
-    1073747585, 5786,       1073747616, 5866,  // NOLINT
-    1073747694, 5880,       1073747712, 5900,
-    1073747726, 5905,       1073747744, 5937,  // NOLINT
-    1073747776, 5969,       1073747808, 5996,
-    1073747822, 6000,       1073747840, 6067,  // NOLINT
-    6103,       6108,       1073748000, 6263,
-    1073748096, 6312,       6314,       1073748144,  // NOLINT
-    6389,       1073748224, 6430,       1073748304,
-    6509,       1073748336, 6516,       1073748352,  // NOLINT
-    6571,       1073748417, 6599,       1073748480,
-    6678,       1073748512, 6740,       6823,  // NOLINT
-    1073748741, 6963,       1073748805, 6987,
-    1073748867, 7072,       1073748910, 7087,  // NOLINT
-    1073748922, 7141,       1073748992, 7203,
-    1073749069, 7247,       1073749082, 7293,  // NOLINT
-    1073749225, 7404,       1073749230, 7409,
-    1073749237, 7414,       1073749248, 7615,  // NOLINT
-    1073749504, 7957,       1073749784, 7965,
-    1073749792, 8005,       1073749832, 8013,  // NOLINT
-    1073749840, 8023,       8025,       8027,
-    8029,       1073749855, 8061,       1073749888,  // NOLINT
-    8116,       1073749942, 8124,       8126,
-    1073749954, 8132,       1073749958, 8140,  // NOLINT
-    1073749968, 8147,       1073749974, 8155,
-    1073749984, 8172,       1073750002, 8180,  // NOLINT
-    1073750006, 8188};                         // NOLINT
+    36,         1073741889, 90,         92,         95,         1073741921,
+    122,        170,        181,        186,        1073742016, 214,
+    1073742040, 246,        1073742072, 705,        1073742534, 721,
+    1073742560, 740,        748,        750,        1073742704, 884,
+    1073742710, 887,        1073742714, 893,        895,        902,
+    1073742728, 906,        908,        1073742734, 929,        1073742755,
+    1013,       1073742839, 1153,       1073742986, 1327,       1073743153,
+    1366,       1369,       1073743201, 1415,       1073743312, 1514,
+    1073743344, 1522,       1073743392, 1610,       1073743470, 1647,
+    1073743473, 1747,       1749,       1073743589, 1766,       1073743598,
+    1775,       1073743610, 1788,       1791,       1808,       1073743634,
+    1839,       1073743693, 1957,       1969,       1073743818, 2026,
+    1073743860, 2037,       2042,       1073743872, 2069,       2074,
+    2084,       2088,       1073743936, 2136,       1073744032, 2226,
+    1073744132, 2361,       2365,       2384,       1073744216, 2401,
+    1073744241, 2432,       1073744261, 2444,       1073744271, 2448,
+    1073744275, 2472,       1073744298, 2480,       2482,       1073744310,
+    2489,       2493,       2510,       1073744348, 2525,       1073744351,
+    2529,       1073744368, 2545,       1073744389, 2570,       1073744399,
+    2576,       1073744403, 2600,       1073744426, 2608,       1073744434,
+    2611,       1073744437, 2614,       1073744440, 2617,       1073744473,
+    2652,       2654,       1073744498, 2676,       1073744517, 2701,
+    1073744527, 2705,       1073744531, 2728,       1073744554, 2736,
+    1073744562, 2739,       1073744565, 2745,       2749,       2768,
+    1073744608, 2785,       1073744645, 2828,       1073744655, 2832,
+    1073744659, 2856,       1073744682, 2864,       1073744690, 2867,
+    1073744693, 2873,       2877,       1073744732, 2909,       1073744735,
+    2913,       2929,       2947,       1073744773, 2954,       1073744782,
+    2960,       1073744786, 2965,       1073744793, 2970,       2972,
+    1073744798, 2975,       1073744803, 2980,       1073744808, 2986,
+    1073744814, 3001,       3024,       1073744901, 3084,       1073744910,
+    3088,       1073744914, 3112,       1073744938, 3129,       3133,
+    1073744984, 3161,       1073744992, 3169,       1073745029, 3212,
+    1073745038, 3216,       1073745042, 3240,       1073745066, 3251,
+    1073745077, 3257,       3261,       3294,       1073745120, 3297,
+    1073745137, 3314,       1073745157, 3340,       1073745166, 3344,
+    1073745170, 3386,       3389,       3406,       1073745248, 3425,
+    1073745274, 3455,       1073745285, 3478,       1073745306, 3505,
+    1073745331, 3515,       3517,       1073745344, 3526,       1073745409,
+    3632,       1073745458, 3635,       1073745472, 3654,       1073745537,
+    3714,       3716,       1073745543, 3720,       3722,       3725,
+    1073745556, 3735,       1073745561, 3743,       1073745569, 3747,
+    3749,       3751,       1073745578, 3755,       1073745581, 3760,
+    1073745586, 3763,       3773,       1073745600, 3780,       3782,
+    1073745628, 3807,       3840,       1073745728, 3911,       1073745737,
+    3948,       1073745800, 3980,       1073745920, 4138,       4159,
+    1073746000, 4181,       1073746010, 4189,       4193,       1073746021,
+    4198,       1073746030, 4208,       1073746037, 4225,       4238,
+    1073746080, 4293,       4295,       4301,       1073746128, 4346,
+    1073746172, 4680,       1073746506, 4685,       1073746512, 4694,
+    4696,       1073746522, 4701,       1073746528, 4744,       1073746570,
+    4749,       1073746576, 4784,       1073746610, 4789,       1073746616,
+    4798,       4800,       1073746626, 4805,       1073746632, 4822,
+    1073746648, 4880,       1073746706, 4885,       1073746712, 4954,
+    1073746816, 5007,       1073746848, 5108,       1073746945, 5740,
+    1073747567, 5759,       1073747585, 5786,       1073747616, 5866,
+    1073747694, 5880,       1073747712, 5900,       1073747726, 5905,
+    1073747744, 5937,       1073747776, 5969,       1073747808, 5996,
+    1073747822, 6000,       1073747840, 6067,       6103,       6108,
+    1073748000, 6263,       1073748096, 6312,       6314,       1073748144,
+    6389,       1073748224, 6430,       1073748304, 6509,       1073748336,
+    6516,       1073748352, 6571,       1073748417, 6599,       1073748480,
+    6678,       1073748512, 6740,       6823,       1073748741, 6963,
+    1073748805, 6987,       1073748867, 7072,       1073748910, 7087,
+    1073748922, 7141,       1073748992, 7203,       1073749069, 7247,
+    1073749082, 7293,       1073749225, 7404,       1073749230, 7409,
+    1073749237, 7414,       1073749248, 7615,       1073749504, 7957,
+    1073749784, 7965,       1073749792, 8005,       1073749832, 8013,
+    1073749840, 8023,       8025,       8027,       8029,       1073749855,
+    8061,       1073749888, 8116,       1073749942, 8124,       8126,
+    1073749954, 8132,       1073749958, 8140,       1073749968, 8147,
+    1073749974, 8155,       1073749984, 8172,       1073750002, 8180,
+    1073750006, 8188};
 static const uint16_t kID_StartTable1Size = 84;
 static const int32_t kID_StartTable1[84] = {
-    113,        127,        1073741968, 156,
-    258,        263,        1073742090, 275,  // NOLINT
-    277,        1073742104, 285,        292,
-    294,        296,        1073742122, 313,  // NOLINT
-    1073742140, 319,        1073742149, 329,
-    334,        1073742176, 392,        1073744896,  // NOLINT
-    3118,       1073744944, 3166,       1073744992,
-    3300,       1073745131, 3310,       1073745138,  // NOLINT
-    3315,       1073745152, 3365,       3367,
-    3373,       1073745200, 3431,       3439,  // NOLINT
-    1073745280, 3478,       1073745312, 3494,
-    1073745320, 3502,       1073745328, 3510,  // NOLINT
-    1073745336, 3518,       1073745344, 3526,
-    1073745352, 3534,       1073745360, 3542,  // NOLINT
-    1073745368, 3550,       1073745925, 4103,
-    1073745953, 4137,       1073745969, 4149,  // NOLINT
-    1073745976, 4156,       1073745985, 4246,
-    1073746075, 4255,       1073746081, 4346,  // NOLINT
-    1073746172, 4351,       1073746181, 4397,
-    1073746225, 4494,       1073746336, 4538,   // NOLINT
-    1073746416, 4607,       1073746944, 8191};  // NOLINT
+    113,        127,        1073741968, 156,        258,        263,
+    1073742090, 275,        277,        1073742104, 285,        292,
+    294,        296,        1073742122, 313,        1073742140, 319,
+    1073742149, 329,        334,        1073742176, 392,        1073744896,
+    3118,       1073744944, 3166,       1073744992, 3300,       1073745131,
+    3310,       1073745138, 3315,       1073745152, 3365,       3367,
+    3373,       1073745200, 3431,       3439,       1073745280, 3478,
+    1073745312, 3494,       1073745320, 3502,       1073745328, 3510,
+    1073745336, 3518,       1073745344, 3526,       1073745352, 3534,
+    1073745360, 3542,       1073745368, 3550,       1073745925, 4103,
+    1073745953, 4137,       1073745969, 4149,       1073745976, 4156,
+    1073745985, 4246,       1073746075, 4255,       1073746081, 4346,
+    1073746172, 4351,       1073746181, 4397,       1073746225, 4494,
+    1073746336, 4538,       1073746416, 4607,       1073746944, 8191};
 static const uint16_t kID_StartTable2Size = 4;
-static const int32_t kID_StartTable2[4] = {1073741824, 3509, 1073745408,
-                                           8191};  // NOLINT
+static const int32_t kID_StartTable2[4] = {1073741824, 3509, 1073745408, 8191};
 static const uint16_t kID_StartTable3Size = 2;
-static const int32_t kID_StartTable3[2] = {1073741824, 8191};  // NOLINT
+static const int32_t kID_StartTable3[2] = {1073741824, 8191};
 static const uint16_t kID_StartTable4Size = 2;
-static const int32_t kID_StartTable4[2] = {1073741824, 8140};  // NOLINT
+static const int32_t kID_StartTable4[2] = {1073741824, 8140};
 static const uint16_t kID_StartTable5Size = 100;
 static const int32_t kID_StartTable5[100] = {
-    1073741824, 1164,       1073743056, 1277,
-    1073743104, 1548,       1073743376, 1567,  // NOLINT
-    1073743402, 1579,       1073743424, 1646,
-    1073743487, 1693,       1073743520, 1775,  // NOLINT
-    1073743639, 1823,       1073743650, 1928,
-    1073743755, 1934,       1073743760, 1965,  // NOLINT
-    1073743792, 1969,       1073743863, 2049,
-    1073743875, 2053,       1073743879, 2058,  // NOLINT
-    1073743884, 2082,       1073743936, 2163,
-    1073744002, 2227,       1073744114, 2295,  // NOLINT
-    2299,       1073744138, 2341,       1073744176,
-    2374,       1073744224, 2428,       1073744260,  // NOLINT
-    2482,       2511,       1073744352, 2532,
-    1073744358, 2543,       1073744378, 2558,  // NOLINT
-    1073744384, 2600,       1073744448, 2626,
-    1073744452, 2635,       1073744480, 2678,  // NOLINT
-    2682,       1073744510, 2735,       2737,
-    1073744565, 2742,       1073744569, 2749,  // NOLINT
-    2752,       2754,       1073744603, 2781,
-    1073744608, 2794,       1073744626, 2804,  // NOLINT
-    1073744641, 2822,       1073744649, 2830,
-    1073744657, 2838,       1073744672, 2854,  // NOLINT
-    1073744680, 2862,       1073744688, 2906,
-    1073744732, 2911,       1073744740, 2917,   // NOLINT
-    1073744832, 3042,       1073744896, 8191};  // NOLINT
+    1073741824, 1164,       1073743056, 1277,       1073743104, 1548,
+    1073743376, 1567,       1073743402, 1579,       1073743424, 1646,
+    1073743487, 1693,       1073743520, 1775,       1073743639, 1823,
+    1073743650, 1928,       1073743755, 1934,       1073743760, 1965,
+    1073743792, 1969,       1073743863, 2049,       1073743875, 2053,
+    1073743879, 2058,       1073743884, 2082,       1073743936, 2163,
+    1073744002, 2227,       1073744114, 2295,       2299,       1073744138,
+    2341,       1073744176, 2374,       1073744224, 2428,       1073744260,
+    2482,       2511,       1073744352, 2532,       1073744358, 2543,
+    1073744378, 2558,       1073744384, 2600,       1073744448, 2626,
+    1073744452, 2635,       1073744480, 2678,       2682,       1073744510,
+    2735,       2737,       1073744565, 2742,       1073744569, 2749,
+    2752,       2754,       1073744603, 2781,       1073744608, 2794,
+    1073744626, 2804,       1073744641, 2822,       1073744649, 2830,
+    1073744657, 2838,       1073744672, 2854,       1073744680, 2862,
+    1073744688, 2906,       1073744732, 2911,       1073744740, 2917,
+    1073744832, 3042,       1073744896, 8191};
 static const uint16_t kID_StartTable6Size = 6;
-static const int32_t kID_StartTable6[6] = {1073741824, 6051, 1073747888, 6086,
-                                           1073747915, 6139};  // NOLINT
+static const int32_t kID_StartTable6[6] = {1073741824, 6051,       1073747888,
+                                           6086,       1073747915, 6139};
 static const uint16_t kID_StartTable7Size = 48;
 static const int32_t kID_StartTable7[48] = {
-    1073748224, 6765,       1073748592, 6873,
-    1073748736, 6918,       1073748755, 6935,  // NOLINT
-    6941,       1073748767, 6952,       1073748778,
-    6966,       1073748792, 6972,       6974,  // NOLINT
-    1073748800, 6977,       1073748803, 6980,
-    1073748806, 7089,       1073748947, 7485,  // NOLINT
-    1073749328, 7567,       1073749394, 7623,
-    1073749488, 7675,       1073749616, 7796,  // NOLINT
-    1073749622, 7932,       1073749793, 7994,
-    1073749825, 8026,       1073749862, 8126,  // NOLINT
-    1073749954, 8135,       1073749962, 8143,
-    1073749970, 8151,       1073749978, 8156};  // NOLINT
+    1073748224, 6765,       1073748592, 6873,       1073748736, 6918,
+    1073748755, 6935,       6941,       1073748767, 6952,       1073748778,
+    6966,       1073748792, 6972,       6974,       1073748800, 6977,
+    1073748803, 6980,       1073748806, 7089,       1073748947, 7485,
+    1073749328, 7567,       1073749394, 7623,       1073749488, 7675,
+    1073749616, 7796,       1073749622, 7932,       1073749793, 7994,
+    1073749825, 8026,       1073749862, 8126,       1073749954, 8135,
+    1073749962, 8143,       1073749970, 8151,       1073749978, 8156};
 bool ID_Start::Is(uchar c) {
   int chunk_index = c >> 13;
   switch (chunk_index) {
@@ -844,115 +684,82 @@ bool ID_Start::Is(uchar c) {
 
 static const uint16_t kID_ContinueTable0Size = 315;
 static const int32_t kID_ContinueTable0[315] = {
-    1073741872, 57,         95,         183,
-    1073742592, 879,        903,        1073742979,  // NOLINT
-    1159,       1073743249, 1469,       1471,
-    1073743297, 1474,       1073743300, 1477,  // NOLINT
-    1479,       1073743376, 1562,       1073743435,
-    1641,       1648,       1073743574, 1756,  // NOLINT
-    1073743583, 1764,       1073743591, 1768,
-    1073743594, 1773,       1073743600, 1785,  // NOLINT
-    1809,       1073743664, 1866,       1073743782,
-    1968,       1073743808, 1993,       1073743851,  // NOLINT
-    2035,       1073743894, 2073,       1073743899,
-    2083,       1073743909, 2087,       1073743913,  // NOLINT
-    2093,       1073743961, 2139,       1073744100,
-    2307,       1073744186, 2364,       1073744190,  // NOLINT
-    2383,       1073744209, 2391,       1073744226,
-    2403,       1073744230, 2415,       1073744257,  // NOLINT
-    2435,       2492,       1073744318, 2500,
-    1073744327, 2504,       1073744331, 2509,  // NOLINT
-    2519,       1073744354, 2531,       1073744358,
-    2543,       1073744385, 2563,       2620,  // NOLINT
-    1073744446, 2626,       1073744455, 2632,
-    1073744459, 2637,       2641,       1073744486,  // NOLINT
-    2673,       2677,       1073744513, 2691,
-    2748,       1073744574, 2757,       1073744583,  // NOLINT
-    2761,       1073744587, 2765,       1073744610,
-    2787,       1073744614, 2799,       1073744641,  // NOLINT
-    2819,       2876,       1073744702, 2884,
-    1073744711, 2888,       1073744715, 2893,  // NOLINT
-    1073744726, 2903,       1073744738, 2915,
-    1073744742, 2927,       2946,       1073744830,  // NOLINT
-    3010,       1073744838, 3016,       1073744842,
-    3021,       3031,       1073744870, 3055,  // NOLINT
-    1073744896, 3075,       1073744958, 3140,
-    1073744966, 3144,       1073744970, 3149,  // NOLINT
-    1073744981, 3158,       1073744994, 3171,
-    1073744998, 3183,       1073745025, 3203,  // NOLINT
-    3260,       1073745086, 3268,       1073745094,
-    3272,       1073745098, 3277,       1073745109,  // NOLINT
-    3286,       1073745122, 3299,       1073745126,
-    3311,       1073745153, 3331,       1073745214,  // NOLINT
-    3396,       1073745222, 3400,       1073745226,
-    3405,       3415,       1073745250, 3427,  // NOLINT
-    1073745254, 3439,       1073745282, 3459,
-    3530,       1073745359, 3540,       3542,  // NOLINT
-    1073745368, 3551,       1073745382, 3567,
-    1073745394, 3571,       3633,       1073745460,  // NOLINT
-    3642,       1073745479, 3662,       1073745488,
-    3673,       3761,       1073745588, 3769,  // NOLINT
-    1073745595, 3772,       1073745608, 3789,
-    1073745616, 3801,       1073745688, 3865,  // NOLINT
-    1073745696, 3881,       3893,       3895,
-    3897,       1073745726, 3903,       1073745777,  // NOLINT
-    3972,       1073745798, 3975,       1073745805,
-    3991,       1073745817, 4028,       4038,  // NOLINT
-    1073745963, 4158,       1073745984, 4169,
-    1073746006, 4185,       1073746014, 4192,  // NOLINT
-    1073746018, 4196,       1073746023, 4205,
-    1073746033, 4212,       1073746050, 4237,  // NOLINT
-    1073746063, 4253,       1073746781, 4959,
-    1073746793, 4977,       1073747730, 5908,  // NOLINT
-    1073747762, 5940,       1073747794, 5971,
-    1073747826, 6003,       1073747892, 6099,  // NOLINT
-    6109,       1073747936, 6121,       1073747979,
-    6157,       1073747984, 6169,       6313,  // NOLINT
-    1073748256, 6443,       1073748272, 6459,
-    1073748294, 6479,       1073748400, 6592,  // NOLINT
-    1073748424, 6601,       1073748432, 6618,
-    1073748503, 6683,       1073748565, 6750,  // NOLINT
-    1073748576, 6780,       1073748607, 6793,
-    1073748624, 6809,       1073748656, 6845,  // NOLINT
-    1073748736, 6916,       1073748788, 6980,
-    1073748816, 7001,       1073748843, 7027,  // NOLINT
-    1073748864, 7042,       1073748897, 7085,
-    1073748912, 7097,       1073748966, 7155,  // NOLINT
-    1073749028, 7223,       1073749056, 7241,
-    1073749072, 7257,       1073749200, 7378,  // NOLINT
-    1073749204, 7400,       7405,       1073749234,
-    7412,       1073749240, 7417,       1073749440,  // NOLINT
-    7669,       1073749500, 7679};                   // NOLINT
+    1073741872, 57,         95,         183,        1073742592, 879,
+    903,        1073742979, 1159,       1073743249, 1469,       1471,
+    1073743297, 1474,       1073743300, 1477,       1479,       1073743376,
+    1562,       1073743435, 1641,       1648,       1073743574, 1756,
+    1073743583, 1764,       1073743591, 1768,       1073743594, 1773,
+    1073743600, 1785,       1809,       1073743664, 1866,       1073743782,
+    1968,       1073743808, 1993,       1073743851, 2035,       1073743894,
+    2073,       1073743899, 2083,       1073743909, 2087,       1073743913,
+    2093,       1073743961, 2139,       1073744100, 2307,       1073744186,
+    2364,       1073744190, 2383,       1073744209, 2391,       1073744226,
+    2403,       1073744230, 2415,       1073744257, 2435,       2492,
+    1073744318, 2500,       1073744327, 2504,       1073744331, 2509,
+    2519,       1073744354, 2531,       1073744358, 2543,       1073744385,
+    2563,       2620,       1073744446, 2626,       1073744455, 2632,
+    1073744459, 2637,       2641,       1073744486, 2673,       2677,
+    1073744513, 2691,       2748,       1073744574, 2757,       1073744583,
+    2761,       1073744587, 2765,       1073744610, 2787,       1073744614,
+    2799,       1073744641, 2819,       2876,       1073744702, 2884,
+    1073744711, 2888,       1073744715, 2893,       1073744726, 2903,
+    1073744738, 2915,       1073744742, 2927,       2946,       1073744830,
+    3010,       1073744838, 3016,       1073744842, 3021,       3031,
+    1073744870, 3055,       1073744896, 3075,       1073744958, 3140,
+    1073744966, 3144,       1073744970, 3149,       1073744981, 3158,
+    1073744994, 3171,       1073744998, 3183,       1073745025, 3203,
+    3260,       1073745086, 3268,       1073745094, 3272,       1073745098,
+    3277,       1073745109, 3286,       1073745122, 3299,       1073745126,
+    3311,       1073745153, 3331,       1073745214, 3396,       1073745222,
+    3400,       1073745226, 3405,       3415,       1073745250, 3427,
+    1073745254, 3439,       1073745282, 3459,       3530,       1073745359,
+    3540,       3542,       1073745368, 3551,       1073745382, 3567,
+    1073745394, 3571,       3633,       1073745460, 3642,       1073745479,
+    3662,       1073745488, 3673,       3761,       1073745588, 3769,
+    1073745595, 3772,       1073745608, 3789,       1073745616, 3801,
+    1073745688, 3865,       1073745696, 3881,       3893,       3895,
+    3897,       1073745726, 3903,       1073745777, 3972,       1073745798,
+    3975,       1073745805, 3991,       1073745817, 4028,       4038,
+    1073745963, 4158,       1073745984, 4169,       1073746006, 4185,
+    1073746014, 4192,       1073746018, 4196,       1073746023, 4205,
+    1073746033, 4212,       1073746050, 4237,       1073746063, 4253,
+    1073746781, 4959,       1073746793, 4977,       1073747730, 5908,
+    1073747762, 5940,       1073747794, 5971,       1073747826, 6003,
+    1073747892, 6099,       6109,       1073747936, 6121,       1073747979,
+    6157,       1073747984, 6169,       6313,       1073748256, 6443,
+    1073748272, 6459,       1073748294, 6479,       1073748400, 6592,
+    1073748424, 6601,       1073748432, 6618,       1073748503, 6683,
+    1073748565, 6750,       1073748576, 6780,       1073748607, 6793,
+    1073748624, 6809,       1073748656, 6845,       1073748736, 6916,
+    1073748788, 6980,       1073748816, 7001,       1073748843, 7027,
+    1073748864, 7042,       1073748897, 7085,       1073748912, 7097,
+    1073748966, 7155,       1073749028, 7223,       1073749056, 7241,
+    1073749072, 7257,       1073749200, 7378,       1073749204, 7400,
+    7405,       1073749234, 7412,       1073749240, 7417,       1073749440,
+    7669,       1073749500, 7679};
 static const uint16_t kID_ContinueTable1Size = 19;
 static const int32_t kID_ContinueTable1[19] = {
-    1073741836, 13,         1073741887, 64,
-    84,         1073742032, 220,        225,  // NOLINT
-    1073742053, 240,        1073745135, 3313,
-    3455,       1073745376, 3583,       1073745962,  // NOLINT
-    4143,       1073746073, 4250};                   // NOLINT
+    1073741836, 13,   1073741887, 64,         84,
+    1073742032, 220,  225,        1073742053, 240,
+    1073745135, 3313, 3455,       1073745376, 3583,
+    1073745962, 4143, 1073746073, 4250};
 static const uint16_t kID_ContinueTable5Size = 63;
 static const int32_t kID_ContinueTable5[63] = {
-    1073743392, 1577,       1647,       1073743476,
-    1661,       1695,       1073743600, 1777,  // NOLINT
-    2050,       2054,       2059,       1073743907,
-    2087,       1073744000, 2177,       1073744052,  // NOLINT
-    2244,       1073744080, 2265,       1073744096,
-    2289,       1073744128, 2313,       1073744166,  // NOLINT
-    2349,       1073744199, 2387,       1073744256,
-    2435,       1073744307, 2496,       1073744336,  // NOLINT
-    2521,       2533,       1073744368, 2553,
-    1073744425, 2614,       2627,       1073744460,  // NOLINT
-    2637,       1073744464, 2649,       1073744507,
-    2685,       2736,       1073744562, 2740,  // NOLINT
-    1073744567, 2744,       1073744574, 2751,
-    2753,       1073744619, 2799,       1073744629,  // NOLINT
-    2806,       1073744867, 3050,       1073744876,
-    3053,       1073744880, 3065};  // NOLINT
+    1073743392, 1577,       1647,       1073743476, 1661,       1695,
+    1073743600, 1777,       2050,       2054,       2059,       1073743907,
+    2087,       1073744000, 2177,       1073744052, 2244,       1073744080,
+    2265,       1073744096, 2289,       1073744128, 2313,       1073744166,
+    2349,       1073744199, 2387,       1073744256, 2435,       1073744307,
+    2496,       1073744336, 2521,       2533,       1073744368, 2553,
+    1073744425, 2614,       2627,       1073744460, 2637,       1073744464,
+    2649,       1073744507, 2685,       2736,       1073744562, 2740,
+    1073744567, 2744,       1073744574, 2751,       2753,       1073744619,
+    2799,       1073744629, 2806,       1073744867, 3050,       1073744876,
+    3053,       1073744880, 3065};
 static const uint16_t kID_ContinueTable7Size = 12;
 static const int32_t kID_ContinueTable7[12] = {
-    6942, 1073749504, 7695, 1073749536,
-    7725, 1073749555, 7732, 1073749581,  // NOLINT
-    7759, 1073749776, 7961, 7999};       // NOLINT
+    6942, 1073749504, 7695, 1073749536, 7725, 1073749555,
+    7732, 1073749581, 7759, 1073749776, 7961, 7999};
 bool ID_Continue::Is(uchar c) {
   int chunk_index = c >> 13;
   switch (chunk_index) {
@@ -973,13 +780,11 @@ bool ID_Continue::Is(uchar c) {
 // point.properties)
 
 static const uint16_t kWhiteSpaceTable0Size = 6;
-static const int32_t kWhiteSpaceTable0[6] = {9,  1073741835, 12,
-                                             32, 160,        5760};  // NOLINT
+static const int32_t kWhiteSpaceTable0[6] = {9, 1073741835, 12, 32, 160, 5760};
 static const uint16_t kWhiteSpaceTable1Size = 5;
-static const int32_t kWhiteSpaceTable1[5] = {1073741824, 10, 47, 95,
-                                             4096};  // NOLINT
+static const int32_t kWhiteSpaceTable1[5] = {1073741824, 10, 47, 95, 4096};
 static const uint16_t kWhiteSpaceTable7Size = 1;
-static const int32_t kWhiteSpaceTable7[1] = {7935};  // NOLINT
+static const int32_t kWhiteSpaceTable7[1] = {7935};
 bool WhiteSpace::Is(uchar c) {
   int chunk_index = c >> 13;
   switch (chunk_index) {
@@ -996,270 +801,189 @@ bool WhiteSpace::Is(uchar c) {
 #endif  // !V8_INTL_SUPPORT
 
 #ifndef V8_INTL_SUPPORT
-static const MultiCharacterSpecialCase<2> kToLowercaseMultiStrings0[2] =
-    {  // NOLINT
-        {{105, 775}},
-        {{kSentinel}}};                              // NOLINT
-static const uint16_t kToLowercaseTable0Size = 488;  // NOLINT
+static const MultiCharacterSpecialCase<2> kToLowercaseMultiStrings0[2] = {
+    {{105, 775}}, {{kSentinel}}};
+static const uint16_t kToLowercaseTable0Size = 488;
 static const int32_t kToLowercaseTable0[976] = {
-    1073741889, 128,    90,         128,   1073742016, 128,
-    214,        128,    1073742040, 128,   222,        128,
-    256,        4,      258,        4,  // NOLINT
-    260,        4,      262,        4,     264,        4,
-    266,        4,      268,        4,     270,        4,
-    272,        4,      274,        4,  // NOLINT
-    276,        4,      278,        4,     280,        4,
-    282,        4,      284,        4,     286,        4,
-    288,        4,      290,        4,  // NOLINT
-    292,        4,      294,        4,     296,        4,
-    298,        4,      300,        4,     302,        4,
-    304,        1,      306,        4,  // NOLINT
-    308,        4,      310,        4,     313,        4,
-    315,        4,      317,        4,     319,        4,
-    321,        4,      323,        4,  // NOLINT
-    325,        4,      327,        4,     330,        4,
-    332,        4,      334,        4,     336,        4,
-    338,        4,      340,        4,  // NOLINT
-    342,        4,      344,        4,     346,        4,
-    348,        4,      350,        4,     352,        4,
-    354,        4,      356,        4,  // NOLINT
-    358,        4,      360,        4,     362,        4,
-    364,        4,      366,        4,     368,        4,
-    370,        4,      372,        4,  // NOLINT
-    374,        4,      376,        -484,  377,        4,
-    379,        4,      381,        4,     385,        840,
-    386,        4,      388,        4,  // NOLINT
-    390,        824,    391,        4,     1073742217, 820,
-    394,        820,    395,        4,     398,        316,
-    399,        808,    400,        812,  // NOLINT
-    401,        4,      403,        820,   404,        828,
-    406,        844,    407,        836,   408,        4,
-    412,        844,    413,        852,  // NOLINT
-    415,        856,    416,        4,     418,        4,
-    420,        4,      422,        872,   423,        4,
-    425,        872,    428,        4,  // NOLINT
-    430,        872,    431,        4,     1073742257, 868,
-    434,        868,    435,        4,     437,        4,
-    439,        876,    440,        4,  // NOLINT
-    444,        4,      452,        8,     453,        4,
-    455,        8,      456,        4,     458,        8,
-    459,        4,      461,        4,  // NOLINT
-    463,        4,      465,        4,     467,        4,
-    469,        4,      471,        4,     473,        4,
-    475,        4,      478,        4,  // NOLINT
-    480,        4,      482,        4,     484,        4,
-    486,        4,      488,        4,     490,        4,
-    492,        4,      494,        4,  // NOLINT
-    497,        8,      498,        4,     500,        4,
-    502,        -388,   503,        -224,  504,        4,
-    506,        4,      508,        4,  // NOLINT
-    510,        4,      512,        4,     514,        4,
-    516,        4,      518,        4,     520,        4,
-    522,        4,      524,        4,  // NOLINT
-    526,        4,      528,        4,     530,        4,
-    532,        4,      534,        4,     536,        4,
-    538,        4,      540,        4,  // NOLINT
-    542,        4,      544,        -520,  546,        4,
-    548,        4,      550,        4,     552,        4,
-    554,        4,      556,        4,  // NOLINT
-    558,        4,      560,        4,     562,        4,
-    570,        43180,  571,        4,     573,        -652,
-    574,        43168,  577,        4,  // NOLINT
-    579,        -780,   580,        276,   581,        284,
-    582,        4,      584,        4,     586,        4,
-    588,        4,      590,        4,  // NOLINT
-    880,        4,      882,        4,     886,        4,
-    895,        464,    902,        152,   1073742728, 148,
-    906,        148,    908,        256,  // NOLINT
-    1073742734, 252,    911,        252,   1073742737, 128,
-    929,        128,    931,        6,     1073742756, 128,
-    939,        128,    975,        32,  // NOLINT
-    984,        4,      986,        4,     988,        4,
-    990,        4,      992,        4,     994,        4,
-    996,        4,      998,        4,  // NOLINT
-    1000,       4,      1002,       4,     1004,       4,
-    1006,       4,      1012,       -240,  1015,       4,
-    1017,       -28,    1018,       4,  // NOLINT
-    1073742845, -520,   1023,       -520,  1073742848, 320,
-    1039,       320,    1073742864, 128,   1071,       128,
-    1120,       4,      1122,       4,  // NOLINT
-    1124,       4,      1126,       4,     1128,       4,
-    1130,       4,      1132,       4,     1134,       4,
-    1136,       4,      1138,       4,  // NOLINT
-    1140,       4,      1142,       4,     1144,       4,
-    1146,       4,      1148,       4,     1150,       4,
-    1152,       4,      1162,       4,  // NOLINT
-    1164,       4,      1166,       4,     1168,       4,
-    1170,       4,      1172,       4,     1174,       4,
-    1176,       4,      1178,       4,  // NOLINT
-    1180,       4,      1182,       4,     1184,       4,
-    1186,       4,      1188,       4,     1190,       4,
-    1192,       4,      1194,       4,  // NOLINT
-    1196,       4,      1198,       4,     1200,       4,
-    1202,       4,      1204,       4,     1206,       4,
-    1208,       4,      1210,       4,  // NOLINT
-    1212,       4,      1214,       4,     1216,       60,
-    1217,       4,      1219,       4,     1221,       4,
-    1223,       4,      1225,       4,  // NOLINT
-    1227,       4,      1229,       4,     1232,       4,
-    1234,       4,      1236,       4,     1238,       4,
-    1240,       4,      1242,       4,  // NOLINT
-    1244,       4,      1246,       4,     1248,       4,
-    1250,       4,      1252,       4,     1254,       4,
-    1256,       4,      1258,       4,  // NOLINT
-    1260,       4,      1262,       4,     1264,       4,
-    1266,       4,      1268,       4,     1270,       4,
-    1272,       4,      1274,       4,  // NOLINT
-    1276,       4,      1278,       4,     1280,       4,
-    1282,       4,      1284,       4,     1286,       4,
-    1288,       4,      1290,       4,  // NOLINT
-    1292,       4,      1294,       4,     1296,       4,
-    1298,       4,      1300,       4,     1302,       4,
-    1304,       4,      1306,       4,  // NOLINT
-    1308,       4,      1310,       4,     1312,       4,
-    1314,       4,      1316,       4,     1318,       4,
-    1320,       4,      1322,       4,  // NOLINT
-    1324,       4,      1326,       4,     1073743153, 192,
-    1366,       192,    1073746080, 29056, 4293,       29056,
-    4295,       29056,  4301,       29056,  // NOLINT
-    7680,       4,      7682,       4,     7684,       4,
-    7686,       4,      7688,       4,     7690,       4,
-    7692,       4,      7694,       4,  // NOLINT
-    7696,       4,      7698,       4,     7700,       4,
-    7702,       4,      7704,       4,     7706,       4,
-    7708,       4,      7710,       4,  // NOLINT
-    7712,       4,      7714,       4,     7716,       4,
-    7718,       4,      7720,       4,     7722,       4,
-    7724,       4,      7726,       4,  // NOLINT
-    7728,       4,      7730,       4,     7732,       4,
-    7734,       4,      7736,       4,     7738,       4,
-    7740,       4,      7742,       4,  // NOLINT
-    7744,       4,      7746,       4,     7748,       4,
-    7750,       4,      7752,       4,     7754,       4,
-    7756,       4,      7758,       4,  // NOLINT
-    7760,       4,      7762,       4,     7764,       4,
-    7766,       4,      7768,       4,     7770,       4,
-    7772,       4,      7774,       4,  // NOLINT
-    7776,       4,      7778,       4,     7780,       4,
-    7782,       4,      7784,       4,     7786,       4,
-    7788,       4,      7790,       4,  // NOLINT
-    7792,       4,      7794,       4,     7796,       4,
-    7798,       4,      7800,       4,     7802,       4,
-    7804,       4,      7806,       4,  // NOLINT
-    7808,       4,      7810,       4,     7812,       4,
-    7814,       4,      7816,       4,     7818,       4,
-    7820,       4,      7822,       4,  // NOLINT
-    7824,       4,      7826,       4,     7828,       4,
-    7838,       -30460, 7840,       4,     7842,       4,
-    7844,       4,      7846,       4,  // NOLINT
-    7848,       4,      7850,       4,     7852,       4,
-    7854,       4,      7856,       4,     7858,       4,
-    7860,       4,      7862,       4,  // NOLINT
-    7864,       4,      7866,       4,     7868,       4,
-    7870,       4,      7872,       4,     7874,       4,
-    7876,       4,      7878,       4,  // NOLINT
-    7880,       4,      7882,       4,     7884,       4,
-    7886,       4,      7888,       4,     7890,       4,
-    7892,       4,      7894,       4,  // NOLINT
-    7896,       4,      7898,       4,     7900,       4,
-    7902,       4,      7904,       4,     7906,       4,
-    7908,       4,      7910,       4,  // NOLINT
-    7912,       4,      7914,       4,     7916,       4,
-    7918,       4,      7920,       4,     7922,       4,
-    7924,       4,      7926,       4,  // NOLINT
-    7928,       4,      7930,       4,     7932,       4,
-    7934,       4,      1073749768, -32,   7951,       -32,
-    1073749784, -32,    7965,       -32,  // NOLINT
-    1073749800, -32,    7983,       -32,   1073749816, -32,
-    7999,       -32,    1073749832, -32,   8013,       -32,
-    8025,       -32,    8027,       -32,  // NOLINT
-    8029,       -32,    8031,       -32,   1073749864, -32,
-    8047,       -32,    1073749896, -32,   8079,       -32,
-    1073749912, -32,    8095,       -32,  // NOLINT
-    1073749928, -32,    8111,       -32,   1073749944, -32,
-    8121,       -32,    1073749946, -296,  8123,       -296,
-    8124,       -36,    1073749960, -344,  // NOLINT
-    8139,       -344,   8140,       -36,   1073749976, -32,
-    8153,       -32,    1073749978, -400,  8155,       -400,
-    1073749992, -32,    8169,       -32,  // NOLINT
-    1073749994, -448,   8171,       -448,  8172,       -28,
-    1073750008, -512,   8185,       -512,  1073750010, -504,
-    8187,       -504,   8188,       -36};                 // NOLINT
-static const uint16_t kToLowercaseMultiStrings0Size = 2;  // NOLINT
-static const MultiCharacterSpecialCase<1> kToLowercaseMultiStrings1[1] =
-    {                                               // NOLINT
-        {{kSentinel}}};                             // NOLINT
-static const uint16_t kToLowercaseTable1Size = 79;  // NOLINT
+    1073741889, 128,   90,         128,   1073742016, 128,   214,        128,
+    1073742040, 128,   222,        128,   256,        4,     258,        4,
+    260,        4,     262,        4,     264,        4,     266,        4,
+    268,        4,     270,        4,     272,        4,     274,        4,
+    276,        4,     278,        4,     280,        4,     282,        4,
+    284,        4,     286,        4,     288,        4,     290,        4,
+    292,        4,     294,        4,     296,        4,     298,        4,
+    300,        4,     302,        4,     304,        1,     306,        4,
+    308,        4,     310,        4,     313,        4,     315,        4,
+    317,        4,     319,        4,     321,        4,     323,        4,
+    325,        4,     327,        4,     330,        4,     332,        4,
+    334,        4,     336,        4,     338,        4,     340,        4,
+    342,        4,     344,        4,     346,        4,     348,        4,
+    350,        4,     352,        4,     354,        4,     356,        4,
+    358,        4,     360,        4,     362,        4,     364,        4,
+    366,        4,     368,        4,     370,        4,     372,        4,
+    374,        4,     376,        -484,  377,        4,     379,        4,
+    381,        4,     385,        840,   386,        4,     388,        4,
+    390,        824,   391,        4,     1073742217, 820,   394,        820,
+    395,        4,     398,        316,   399,        808,   400,        812,
+    401,        4,     403,        820,   404,        828,   406,        844,
+    407,        836,   408,        4,     412,        844,   413,        852,
+    415,        856,   416,        4,     418,        4,     420,        4,
+    422,        872,   423,        4,     425,        872,   428,        4,
+    430,        872,   431,        4,     1073742257, 868,   434,        868,
+    435,        4,     437,        4,     439,        876,   440,        4,
+    444,        4,     452,        8,     453,        4,     455,        8,
+    456,        4,     458,        8,     459,        4,     461,        4,
+    463,        4,     465,        4,     467,        4,     469,        4,
+    471,        4,     473,        4,     475,        4,     478,        4,
+    480,        4,     482,        4,     484,        4,     486,        4,
+    488,        4,     490,        4,     492,        4,     494,        4,
+    497,        8,     498,        4,     500,        4,     502,        -388,
+    503,        -224,  504,        4,     506,        4,     508,        4,
+    510,        4,     512,        4,     514,        4,     516,        4,
+    518,        4,     520,        4,     522,        4,     524,        4,
+    526,        4,     528,        4,     530,        4,     532,        4,
+    534,        4,     536,        4,     538,        4,     540,        4,
+    542,        4,     544,        -520,  546,        4,     548,        4,
+    550,        4,     552,        4,     554,        4,     556,        4,
+    558,        4,     560,        4,     562,        4,     570,        43180,
+    571,        4,     573,        -652,  574,        43168, 577,        4,
+    579,        -780,  580,        276,   581,        284,   582,        4,
+    584,        4,     586,        4,     588,        4,     590,        4,
+    880,        4,     882,        4,     886,        4,     895,        464,
+    902,        152,   1073742728, 148,   906,        148,   908,        256,
+    1073742734, 252,   911,        252,   1073742737, 128,   929,        128,
+    931,        6,     1073742756, 128,   939,        128,   975,        32,
+    984,        4,     986,        4,     988,        4,     990,        4,
+    992,        4,     994,        4,     996,        4,     998,        4,
+    1000,       4,     1002,       4,     1004,       4,     1006,       4,
+    1012,       -240,  1015,       4,     1017,       -28,   1018,       4,
+    1073742845, -520,  1023,       -520,  1073742848, 320,   1039,       320,
+    1073742864, 128,   1071,       128,   1120,       4,     1122,       4,
+    1124,       4,     1126,       4,     1128,       4,     1130,       4,
+    1132,       4,     1134,       4,     1136,       4,     1138,       4,
+    1140,       4,     1142,       4,     1144,       4,     1146,       4,
+    1148,       4,     1150,       4,     1152,       4,     1162,       4,
+    1164,       4,     1166,       4,     1168,       4,     1170,       4,
+    1172,       4,     1174,       4,     1176,       4,     1178,       4,
+    1180,       4,     1182,       4,     1184,       4,     1186,       4,
+    1188,       4,     1190,       4,     1192,       4,     1194,       4,
+    1196,       4,     1198,       4,     1200,       4,     1202,       4,
+    1204,       4,     1206,       4,     1208,       4,     1210,       4,
+    1212,       4,     1214,       4,     1216,       60,    1217,       4,
+    1219,       4,     1221,       4,     1223,       4,     1225,       4,
+    1227,       4,     1229,       4,     1232,       4,     1234,       4,
+    1236,       4,     1238,       4,     1240,       4,     1242,       4,
+    1244,       4,     1246,       4,     1248,       4,     1250,       4,
+    1252,       4,     1254,       4,     1256,       4,     1258,       4,
+    1260,       4,     1262,       4,     1264,       4,     1266,       4,
+    1268,       4,     1270,       4,     1272,       4,     1274,       4,
+    1276,       4,     1278,       4,     1280,       4,     1282,       4,
+    1284,       4,     1286,       4,     1288,       4,     1290,       4,
+    1292,       4,     1294,       4,     1296,       4,     1298,       4,
+    1300,       4,     1302,       4,     1304,       4,     1306,       4,
+    1308,       4,     1310,       4,     1312,       4,     1314,       4,
+    1316,       4,     1318,       4,     1320,       4,     1322,       4,
+    1324,       4,     1326,       4,     1073743153, 192,   1366,       192,
+    1073746080, 29056, 4293,       29056, 4295,       29056, 4301,       29056,
+    7680,       4,     7682,       4,     7684,       4,     7686,       4,
+    7688,       4,     7690,       4,     7692,       4,     7694,       4,
+    7696,       4,     7698,       4,     7700,       4,     7702,       4,
+    7704,       4,     7706,       4,     7708,       4,     7710,       4,
+    7712,       4,     7714,       4,     7716,       4,     7718,       4,
+    7720,       4,     7722,       4,     7724,       4,     7726,       4,
+    7728,       4,     7730,       4,     7732,       4,     7734,       4,
+    7736,       4,     7738,       4,     7740,       4,     7742,       4,
+    7744,       4,     7746,       4,     7748,       4,     7750,       4,
+    7752,       4,     7754,       4,     7756,       4,     7758,       4,
+    7760,       4,     7762,       4,     7764,       4,     7766,       4,
+    7768,       4,     7770,       4,     7772,       4,     7774,       4,
+    7776,       4,     7778,       4,     7780,       4,     7782,       4,
+    7784,       4,     7786,       4,     7788,       4,     7790,       4,
+    7792,       4,     7794,       4,     7796,       4,     7798,       4,
+    7800,       4,     7802,       4,     7804,       4,     7806,       4,
+    7808,       4,     7810,       4,     7812,       4,     7814,       4,
+    7816,       4,     7818,       4,     7820,       4,     7822,       4,
+    7824,       4,     7826,       4,     7828,       4,     7838,       -30460,
+    7840,       4,     7842,       4,     7844,       4,     7846,       4,
+    7848,       4,     7850,       4,     7852,       4,     7854,       4,
+    7856,       4,     7858,       4,     7860,       4,     7862,       4,
+    7864,       4,     7866,       4,     7868,       4,     7870,       4,
+    7872,       4,     7874,       4,     7876,       4,     7878,       4,
+    7880,       4,     7882,       4,     7884,       4,     7886,       4,
+    7888,       4,     7890,       4,     7892,       4,     7894,       4,
+    7896,       4,     7898,       4,     7900,       4,     7902,       4,
+    7904,       4,     7906,       4,     7908,       4,     7910,       4,
+    7912,       4,     7914,       4,     7916,       4,     7918,       4,
+    7920,       4,     7922,       4,     7924,       4,     7926,       4,
+    7928,       4,     7930,       4,     7932,       4,     7934,       4,
+    1073749768, -32,   7951,       -32,   1073749784, -32,   7965,       -32,
+    1073749800, -32,   7983,       -32,   1073749816, -32,   7999,       -32,
+    1073749832, -32,   8013,       -32,   8025,       -32,   8027,       -32,
+    8029,       -32,   8031,       -32,   1073749864, -32,   8047,       -32,
+    1073749896, -32,   8079,       -32,   1073749912, -32,   8095,       -32,
+    1073749928, -32,   8111,       -32,   1073749944, -32,   8121,       -32,
+    1073749946, -296,  8123,       -296,  8124,       -36,   1073749960, -344,
+    8139,       -344,  8140,       -36,   1073749976, -32,   8153,       -32,
+    1073749978, -400,  8155,       -400,  1073749992, -32,   8169,       -32,
+    1073749994, -448,  8171,       -448,  8172,       -28,   1073750008, -512,
+    8185,       -512,  1073750010, -504,  8187,       -504,  8188,       -36};
+static const uint16_t kToLowercaseMultiStrings0Size = 2;
+static const MultiCharacterSpecialCase<1> kToLowercaseMultiStrings1[1] = {
+    {{kSentinel}}};
+static const uint16_t kToLowercaseTable1Size = 79;
 static const int32_t kToLowercaseTable1[158] = {
-    294,        -30068,     298,        -33532, 299,    -33048, 306,
-    112,        1073742176, 64,         367,    64,     387,    4,
-    1073743030, 104,  // NOLINT
-    1231,       104,        1073744896, 192,    3118,   192,    3168,
-    4,          3170,       -42972,     3171,   -15256, 3172,   -42908,
-    3175,       4,  // NOLINT
-    3177,       4,          3179,       4,      3181,   -43120, 3182,
-    -42996,     3183,       -43132,     3184,   -43128, 3186,   4,
-    3189,       4,  // NOLINT
-    1073745022, -43260,     3199,       -43260, 3200,   4,      3202,
-    4,          3204,       4,          3206,   4,      3208,   4,
-    3210,       4,  // NOLINT
-    3212,       4,          3214,       4,      3216,   4,      3218,
-    4,          3220,       4,          3222,   4,      3224,   4,
-    3226,       4,  // NOLINT
-    3228,       4,          3230,       4,      3232,   4,      3234,
-    4,          3236,       4,          3238,   4,      3240,   4,
-    3242,       4,  // NOLINT
-    3244,       4,          3246,       4,      3248,   4,      3250,
-    4,          3252,       4,          3254,   4,      3256,   4,
-    3258,       4,  // NOLINT
-    3260,       4,          3262,       4,      3264,   4,      3266,
-    4,          3268,       4,          3270,   4,      3272,   4,
-    3274,       4,  // NOLINT
-    3276,       4,          3278,       4,      3280,   4,      3282,
-    4,          3284,       4,          3286,   4,      3288,   4,
-    3290,       4,  // NOLINT
-    3292,       4,          3294,       4,      3296,   4,      3298,
-    4,          3307,       4,          3309,   4,      3314,   4};  // NOLINT
-static const uint16_t kToLowercaseMultiStrings1Size = 1;             // NOLINT
-static const MultiCharacterSpecialCase<1> kToLowercaseMultiStrings5[1] =
-    {                                                // NOLINT
-        {{kSentinel}}};                              // NOLINT
-static const uint16_t kToLowercaseTable5Size = 103;  // NOLINT
+    294,        -30068, 298,        -33532, 299,  -33048, 306,        112,
+    1073742176, 64,     367,        64,     387,  4,      1073743030, 104,
+    1231,       104,    1073744896, 192,    3118, 192,    3168,       4,
+    3170,       -42972, 3171,       -15256, 3172, -42908, 3175,       4,
+    3177,       4,      3179,       4,      3181, -43120, 3182,       -42996,
+    3183,       -43132, 3184,       -43128, 3186, 4,      3189,       4,
+    1073745022, -43260, 3199,       -43260, 3200, 4,      3202,       4,
+    3204,       4,      3206,       4,      3208, 4,      3210,       4,
+    3212,       4,      3214,       4,      3216, 4,      3218,       4,
+    3220,       4,      3222,       4,      3224, 4,      3226,       4,
+    3228,       4,      3230,       4,      3232, 4,      3234,       4,
+    3236,       4,      3238,       4,      3240, 4,      3242,       4,
+    3244,       4,      3246,       4,      3248, 4,      3250,       4,
+    3252,       4,      3254,       4,      3256, 4,      3258,       4,
+    3260,       4,      3262,       4,      3264, 4,      3266,       4,
+    3268,       4,      3270,       4,      3272, 4,      3274,       4,
+    3276,       4,      3278,       4,      3280, 4,      3282,       4,
+    3284,       4,      3286,       4,      3288, 4,      3290,       4,
+    3292,       4,      3294,       4,      3296, 4,      3298,       4,
+    3307,       4,      3309,       4,      3314, 4};
+static const uint16_t kToLowercaseMultiStrings1Size = 1;
+static const MultiCharacterSpecialCase<1> kToLowercaseMultiStrings5[1] = {
+    {{kSentinel}}};
+static const uint16_t kToLowercaseTable5Size = 103;
 static const int32_t kToLowercaseTable5[206] = {
-    1600, 4,       1602, 4,       1604, 4,       1606, 4,
-    1608, 4,       1610, 4,       1612, 4,       1614, 4,  // NOLINT
-    1616, 4,       1618, 4,       1620, 4,       1622, 4,
-    1624, 4,       1626, 4,       1628, 4,       1630, 4,  // NOLINT
-    1632, 4,       1634, 4,       1636, 4,       1638, 4,
-    1640, 4,       1642, 4,       1644, 4,       1664, 4,  // NOLINT
-    1666, 4,       1668, 4,       1670, 4,       1672, 4,
-    1674, 4,       1676, 4,       1678, 4,       1680, 4,  // NOLINT
-    1682, 4,       1684, 4,       1686, 4,       1688, 4,
-    1690, 4,       1826, 4,       1828, 4,       1830, 4,  // NOLINT
-    1832, 4,       1834, 4,       1836, 4,       1838, 4,
-    1842, 4,       1844, 4,       1846, 4,       1848, 4,  // NOLINT
-    1850, 4,       1852, 4,       1854, 4,       1856, 4,
-    1858, 4,       1860, 4,       1862, 4,       1864, 4,  // NOLINT
-    1866, 4,       1868, 4,       1870, 4,       1872, 4,
-    1874, 4,       1876, 4,       1878, 4,       1880, 4,  // NOLINT
-    1882, 4,       1884, 4,       1886, 4,       1888, 4,
-    1890, 4,       1892, 4,       1894, 4,       1896, 4,  // NOLINT
-    1898, 4,       1900, 4,       1902, 4,       1913, 4,
-    1915, 4,       1917, -141328, 1918, 4,       1920, 4,  // NOLINT
-    1922, 4,       1924, 4,       1926, 4,       1931, 4,
-    1933, -169120, 1936, 4,       1938, 4,       1942, 4,  // NOLINT
-    1944, 4,       1946, 4,       1948, 4,       1950, 4,
-    1952, 4,       1954, 4,       1956, 4,       1958, 4,  // NOLINT
-    1960, 4,       1962, -169232, 1963, -169276, 1964, -169260,
-    1965, -169220, 1968, -169032, 1969, -169128};         // NOLINT
-static const uint16_t kToLowercaseMultiStrings5Size = 1;  // NOLINT
-static const MultiCharacterSpecialCase<1> kToLowercaseMultiStrings7[1] =
-    {                                              // NOLINT
-        {{kSentinel}}};                            // NOLINT
-static const uint16_t kToLowercaseTable7Size = 2;  // NOLINT
-static const int32_t kToLowercaseTable7[4] = {1073749793, 128, 7994,
-                                              128};       // NOLINT
-static const uint16_t kToLowercaseMultiStrings7Size = 1;  // NOLINT
+    1600, 4,       1602, 4,       1604, 4,       1606, 4,       1608, 4,
+    1610, 4,       1612, 4,       1614, 4,       1616, 4,       1618, 4,
+    1620, 4,       1622, 4,       1624, 4,       1626, 4,       1628, 4,
+    1630, 4,       1632, 4,       1634, 4,       1636, 4,       1638, 4,
+    1640, 4,       1642, 4,       1644, 4,       1664, 4,       1666, 4,
+    1668, 4,       1670, 4,       1672, 4,       1674, 4,       1676, 4,
+    1678, 4,       1680, 4,       1682, 4,       1684, 4,       1686, 4,
+    1688, 4,       1690, 4,       1826, 4,       1828, 4,       1830, 4,
+    1832, 4,       1834, 4,       1836, 4,       1838, 4,       1842, 4,
+    1844, 4,       1846, 4,       1848, 4,       1850, 4,       1852, 4,
+    1854, 4,       1856, 4,       1858, 4,       1860, 4,       1862, 4,
+    1864, 4,       1866, 4,       1868, 4,       1870, 4,       1872, 4,
+    1874, 4,       1876, 4,       1878, 4,       1880, 4,       1882, 4,
+    1884, 4,       1886, 4,       1888, 4,       1890, 4,       1892, 4,
+    1894, 4,       1896, 4,       1898, 4,       1900, 4,       1902, 4,
+    1913, 4,       1915, 4,       1917, -141328, 1918, 4,       1920, 4,
+    1922, 4,       1924, 4,       1926, 4,       1931, 4,       1933, -169120,
+    1936, 4,       1938, 4,       1942, 4,       1944, 4,       1946, 4,
+    1948, 4,       1950, 4,       1952, 4,       1954, 4,       1956, 4,
+    1958, 4,       1960, 4,       1962, -169232, 1963, -169276, 1964, -169260,
+    1965, -169220, 1968, -169032, 1969, -169128};
+static const uint16_t kToLowercaseMultiStrings5Size = 1;
+static const MultiCharacterSpecialCase<1> kToLowercaseMultiStrings7[1] = {
+    {{kSentinel}}};
+static const uint16_t kToLowercaseTable7Size = 2;
+static const int32_t kToLowercaseTable7[4] = {1073749793, 128, 7994, 128};
+static const uint16_t kToLowercaseMultiStrings7Size = 1;
 int ToLowercase::Convert(uchar c, uchar n, uchar* result,
                          bool* allow_caching_ptr) {
   int chunk_index = c >> 13;
@@ -1285,348 +1009,296 @@ int ToLowercase::Convert(uchar c, uchar n, uchar* result,
   }
 }
 
-static const MultiCharacterSpecialCase<3> kToUppercaseMultiStrings0[62] =
-    {  // NOLINT
-        {{83, 83, kSentinel}},    {{700, 78, kSentinel}},
-        {{74, 780, kSentinel}},   {{921, 776, 769}},  // NOLINT
-        {{933, 776, 769}},        {{1333, 1362, kSentinel}},
-        {{72, 817, kSentinel}},   {{84, 776, kSentinel}},  // NOLINT
-        {{87, 778, kSentinel}},   {{89, 778, kSentinel}},
-        {{65, 702, kSentinel}},   {{933, 787, kSentinel}},  // NOLINT
-        {{933, 787, 768}},        {{933, 787, 769}},
-        {{933, 787, 834}},        {{7944, 921, kSentinel}},  // NOLINT
-        {{7945, 921, kSentinel}}, {{7946, 921, kSentinel}},
-        {{7947, 921, kSentinel}}, {{7948, 921, kSentinel}},  // NOLINT
-        {{7949, 921, kSentinel}}, {{7950, 921, kSentinel}},
-        {{7951, 921, kSentinel}}, {{7976, 921, kSentinel}},  // NOLINT
-        {{7977, 921, kSentinel}}, {{7978, 921, kSentinel}},
-        {{7979, 921, kSentinel}}, {{7980, 921, kSentinel}},  // NOLINT
-        {{7981, 921, kSentinel}}, {{7982, 921, kSentinel}},
-        {{7983, 921, kSentinel}}, {{8040, 921, kSentinel}},  // NOLINT
-        {{8041, 921, kSentinel}}, {{8042, 921, kSentinel}},
-        {{8043, 921, kSentinel}}, {{8044, 921, kSentinel}},  // NOLINT
-        {{8045, 921, kSentinel}}, {{8046, 921, kSentinel}},
-        {{8047, 921, kSentinel}}, {{8122, 921, kSentinel}},  // NOLINT
-        {{913, 921, kSentinel}},  {{902, 921, kSentinel}},
-        {{913, 834, kSentinel}},  {{913, 834, 921}},  // NOLINT
-        {{8138, 921, kSentinel}}, {{919, 921, kSentinel}},
-        {{905, 921, kSentinel}},  {{919, 834, kSentinel}},  // NOLINT
-        {{919, 834, 921}},        {{921, 776, 768}},
-        {{921, 834, kSentinel}},  {{921, 776, 834}},  // NOLINT
-        {{933, 776, 768}},        {{929, 787, kSentinel}},
-        {{933, 834, kSentinel}},  {{933, 776, 834}},  // NOLINT
-        {{8186, 921, kSentinel}}, {{937, 921, kSentinel}},
-        {{911, 921, kSentinel}},  {{937, 834, kSentinel}},  // NOLINT
-        {{937, 834, 921}},        {{kSentinel}}};           // NOLINT
-static const uint16_t kToUppercaseTable0Size = 590;         // NOLINT
+static const MultiCharacterSpecialCase<3> kToUppercaseMultiStrings0[62] = {
+    {{83, 83, kSentinel}},    {{700, 78, kSentinel}},
+    {{74, 780, kSentinel}},   {{921, 776, 769}},
+    {{933, 776, 769}},        {{1333, 1362, kSentinel}},
+    {{72, 817, kSentinel}},   {{84, 776, kSentinel}},
+    {{87, 778, kSentinel}},   {{89, 778, kSentinel}},
+    {{65, 702, kSentinel}},   {{933, 787, kSentinel}},
+    {{933, 787, 768}},        {{933, 787, 769}},
+    {{933, 787, 834}},        {{7944, 921, kSentinel}},
+    {{7945, 921, kSentinel}}, {{7946, 921, kSentinel}},
+    {{7947, 921, kSentinel}}, {{7948, 921, kSentinel}},
+    {{7949, 921, kSentinel}}, {{7950, 921, kSentinel}},
+    {{7951, 921, kSentinel}}, {{7976, 921, kSentinel}},
+    {{7977, 921, kSentinel}}, {{7978, 921, kSentinel}},
+    {{7979, 921, kSentinel}}, {{7980, 921, kSentinel}},
+    {{7981, 921, kSentinel}}, {{7982, 921, kSentinel}},
+    {{7983, 921, kSentinel}}, {{8040, 921, kSentinel}},
+    {{8041, 921, kSentinel}}, {{8042, 921, kSentinel}},
+    {{8043, 921, kSentinel}}, {{8044, 921, kSentinel}},
+    {{8045, 921, kSentinel}}, {{8046, 921, kSentinel}},
+    {{8047, 921, kSentinel}}, {{8122, 921, kSentinel}},
+    {{913, 921, kSentinel}},  {{902, 921, kSentinel}},
+    {{913, 834, kSentinel}},  {{913, 834, 921}},
+    {{8138, 921, kSentinel}}, {{919, 921, kSentinel}},
+    {{905, 921, kSentinel}},  {{919, 834, kSentinel}},
+    {{919, 834, 921}},        {{921, 776, 768}},
+    {{921, 834, kSentinel}},  {{921, 776, 834}},
+    {{933, 776, 768}},        {{929, 787, kSentinel}},
+    {{933, 834, kSentinel}},  {{933, 776, 834}},
+    {{8186, 921, kSentinel}}, {{937, 921, kSentinel}},
+    {{911, 921, kSentinel}},  {{937, 834, kSentinel}},
+    {{937, 834, 921}},        {{kSentinel}}};
+static const uint16_t kToUppercaseTable0Size = 590;
 static const int32_t kToUppercaseTable0[1180] = {
     1073741921, -128,   122,        -128,   181,        2972,
     223,        1,      1073742048, -128,   246,        -128,
-    1073742072, -128,   254,        -128,  // NOLINT
-    255,        484,    257,        -4,     259,        -4,
-    261,        -4,     263,        -4,     265,        -4,
-    267,        -4,     269,        -4,  // NOLINT
-    271,        -4,     273,        -4,     275,        -4,
-    277,        -4,     279,        -4,     281,        -4,
-    283,        -4,     285,        -4,  // NOLINT
+    1073742072, -128,   254,        -128,   255,        484,
+    257,        -4,     259,        -4,     261,        -4,
+    263,        -4,     265,        -4,     267,        -4,
+    269,        -4,     271,        -4,     273,        -4,
+    275,        -4,     277,        -4,     279,        -4,
+    281,        -4,     283,        -4,     285,        -4,
     287,        -4,     289,        -4,     291,        -4,
     293,        -4,     295,        -4,     297,        -4,
-    299,        -4,     301,        -4,  // NOLINT
-    303,        -4,     305,        -928,   307,        -4,
-    309,        -4,     311,        -4,     314,        -4,
-    316,        -4,     318,        -4,  // NOLINT
-    320,        -4,     322,        -4,     324,        -4,
-    326,        -4,     328,        -4,     329,        5,
-    331,        -4,     333,        -4,  // NOLINT
+    299,        -4,     301,        -4,     303,        -4,
+    305,        -928,   307,        -4,     309,        -4,
+    311,        -4,     314,        -4,     316,        -4,
+    318,        -4,     320,        -4,     322,        -4,
+    324,        -4,     326,        -4,     328,        -4,
+    329,        5,      331,        -4,     333,        -4,
     335,        -4,     337,        -4,     339,        -4,
     341,        -4,     343,        -4,     345,        -4,
-    347,        -4,     349,        -4,  // NOLINT
-    351,        -4,     353,        -4,     355,        -4,
-    357,        -4,     359,        -4,     361,        -4,
-    363,        -4,     365,        -4,  // NOLINT
-    367,        -4,     369,        -4,     371,        -4,
-    373,        -4,     375,        -4,     378,        -4,
-    380,        -4,     382,        -4,  // NOLINT
+    347,        -4,     349,        -4,     351,        -4,
+    353,        -4,     355,        -4,     357,        -4,
+    359,        -4,     361,        -4,     363,        -4,
+    365,        -4,     367,        -4,     369,        -4,
+    371,        -4,     373,        -4,     375,        -4,
+    378,        -4,     380,        -4,     382,        -4,
     383,        -1200,  384,        780,    387,        -4,
     389,        -4,     392,        -4,     396,        -4,
-    402,        -4,     405,        388,  // NOLINT
-    409,        -4,     410,        652,    414,        520,
-    417,        -4,     419,        -4,     421,        -4,
-    424,        -4,     429,        -4,  // NOLINT
-    432,        -4,     436,        -4,     438,        -4,
-    441,        -4,     445,        -4,     447,        224,
-    453,        -4,     454,        -8,  // NOLINT
+    402,        -4,     405,        388,    409,        -4,
+    410,        652,    414,        520,    417,        -4,
+    419,        -4,     421,        -4,     424,        -4,
+    429,        -4,     432,        -4,     436,        -4,
+    438,        -4,     441,        -4,     445,        -4,
+    447,        224,    453,        -4,     454,        -8,
     456,        -4,     457,        -8,     459,        -4,
     460,        -8,     462,        -4,     464,        -4,
-    466,        -4,     468,        -4,  // NOLINT
-    470,        -4,     472,        -4,     474,        -4,
-    476,        -4,     477,        -316,   479,        -4,
-    481,        -4,     483,        -4,  // NOLINT
-    485,        -4,     487,        -4,     489,        -4,
-    491,        -4,     493,        -4,     495,        -4,
-    496,        9,      498,        -4,  // NOLINT
+    466,        -4,     468,        -4,     470,        -4,
+    472,        -4,     474,        -4,     476,        -4,
+    477,        -316,   479,        -4,     481,        -4,
+    483,        -4,     485,        -4,     487,        -4,
+    489,        -4,     491,        -4,     493,        -4,
+    495,        -4,     496,        9,      498,        -4,
     499,        -8,     501,        -4,     505,        -4,
     507,        -4,     509,        -4,     511,        -4,
-    513,        -4,     515,        -4,  // NOLINT
-    517,        -4,     519,        -4,     521,        -4,
-    523,        -4,     525,        -4,     527,        -4,
-    529,        -4,     531,        -4,  // NOLINT
-    533,        -4,     535,        -4,     537,        -4,
-    539,        -4,     541,        -4,     543,        -4,
-    547,        -4,     549,        -4,  // NOLINT
+    513,        -4,     515,        -4,     517,        -4,
+    519,        -4,     521,        -4,     523,        -4,
+    525,        -4,     527,        -4,     529,        -4,
+    531,        -4,     533,        -4,     535,        -4,
+    537,        -4,     539,        -4,     541,        -4,
+    543,        -4,     547,        -4,     549,        -4,
     551,        -4,     553,        -4,     555,        -4,
     557,        -4,     559,        -4,     561,        -4,
-    563,        -4,     572,        -4,  // NOLINT
-    1073742399, 43260,  576,        43260,  578,        -4,
-    583,        -4,     585,        -4,     587,        -4,
-    589,        -4,     591,        -4,  // NOLINT
-    592,        43132,  593,        43120,  594,        43128,
-    595,        -840,   596,        -824,   1073742422, -820,
-    599,        -820,   601,        -808,  // NOLINT
+    563,        -4,     572,        -4,     1073742399, 43260,
+    576,        43260,  578,        -4,     583,        -4,
+    585,        -4,     587,        -4,     589,        -4,
+    591,        -4,     592,        43132,  593,        43120,
+    594,        43128,  595,        -840,   596,        -824,
+    1073742422, -820,   599,        -820,   601,        -808,
     603,        -812,   604,        169276, 608,        -820,
     609,        169260, 611,        -828,   613,        169120,
-    614,        169232, 616,        -836,  // NOLINT
-    617,        -844,   619,        42972,  620,        169220,
-    623,        -844,   625,        42996,  626,        -852,
-    629,        -856,   637,        42908,  // NOLINT
-    640,        -872,   643,        -872,   647,        169128,
-    648,        -872,   649,        -276,   1073742474, -868,
-    651,        -868,   652,        -284,  // NOLINT
+    614,        169232, 616,        -836,   617,        -844,
+    619,        42972,  620,        169220, 623,        -844,
+    625,        42996,  626,        -852,   629,        -856,
+    637,        42908,  640,        -872,   643,        -872,
+    647,        169128, 648,        -872,   649,        -276,
+    1073742474, -868,   651,        -868,   652,        -284,
     658,        -876,   670,        169032, 837,        336,
     881,        -4,     883,        -4,     887,        -4,
-    1073742715, 520,    893,        520,  // NOLINT
-    912,        13,     940,        -152,   1073742765, -148,
-    943,        -148,   944,        17,     1073742769, -128,
-    961,        -128,   962,        -124,  // NOLINT
-    1073742787, -128,   971,        -128,   972,        -256,
-    1073742797, -252,   974,        -252,   976,        -248,
-    977,        -228,   981,        -188,  // NOLINT
+    1073742715, 520,    893,        520,    912,        13,
+    940,        -152,   1073742765, -148,   943,        -148,
+    944,        17,     1073742769, -128,   961,        -128,
+    962,        -124,   1073742787, -128,   971,        -128,
+    972,        -256,   1073742797, -252,   974,        -252,
+    976,        -248,   977,        -228,   981,        -188,
     982,        -216,   983,        -32,    985,        -4,
     987,        -4,     989,        -4,     991,        -4,
-    993,        -4,     995,        -4,  // NOLINT
-    997,        -4,     999,        -4,     1001,       -4,
-    1003,       -4,     1005,       -4,     1007,       -4,
-    1008,       -344,   1009,       -320,  // NOLINT
-    1010,       28,     1011,       -464,   1013,       -384,
-    1016,       -4,     1019,       -4,     1073742896, -128,
-    1103,       -128,   1073742928, -320,  // NOLINT
+    993,        -4,     995,        -4,     997,        -4,
+    999,        -4,     1001,       -4,     1003,       -4,
+    1005,       -4,     1007,       -4,     1008,       -344,
+    1009,       -320,   1010,       28,     1011,       -464,
+    1013,       -384,   1016,       -4,     1019,       -4,
+    1073742896, -128,   1103,       -128,   1073742928, -320,
     1119,       -320,   1121,       -4,     1123,       -4,
     1125,       -4,     1127,       -4,     1129,       -4,
-    1131,       -4,     1133,       -4,  // NOLINT
-    1135,       -4,     1137,       -4,     1139,       -4,
-    1141,       -4,     1143,       -4,     1145,       -4,
-    1147,       -4,     1149,       -4,  // NOLINT
-    1151,       -4,     1153,       -4,     1163,       -4,
-    1165,       -4,     1167,       -4,     1169,       -4,
-    1171,       -4,     1173,       -4,  // NOLINT
+    1131,       -4,     1133,       -4,     1135,       -4,
+    1137,       -4,     1139,       -4,     1141,       -4,
+    1143,       -4,     1145,       -4,     1147,       -4,
+    1149,       -4,     1151,       -4,     1153,       -4,
+    1163,       -4,     1165,       -4,     1167,       -4,
+    1169,       -4,     1171,       -4,     1173,       -4,
     1175,       -4,     1177,       -4,     1179,       -4,
     1181,       -4,     1183,       -4,     1185,       -4,
-    1187,       -4,     1189,       -4,  // NOLINT
-    1191,       -4,     1193,       -4,     1195,       -4,
-    1197,       -4,     1199,       -4,     1201,       -4,
-    1203,       -4,     1205,       -4,  // NOLINT
-    1207,       -4,     1209,       -4,     1211,       -4,
-    1213,       -4,     1215,       -4,     1218,       -4,
-    1220,       -4,     1222,       -4,  // NOLINT
+    1187,       -4,     1189,       -4,     1191,       -4,
+    1193,       -4,     1195,       -4,     1197,       -4,
+    1199,       -4,     1201,       -4,     1203,       -4,
+    1205,       -4,     1207,       -4,     1209,       -4,
+    1211,       -4,     1213,       -4,     1215,       -4,
+    1218,       -4,     1220,       -4,     1222,       -4,
     1224,       -4,     1226,       -4,     1228,       -4,
     1230,       -4,     1231,       -60,    1233,       -4,
-    1235,       -4,     1237,       -4,  // NOLINT
-    1239,       -4,     1241,       -4,     1243,       -4,
-    1245,       -4,     1247,       -4,     1249,       -4,
-    1251,       -4,     1253,       -4,  // NOLINT
-    1255,       -4,     1257,       -4,     1259,       -4,
-    1261,       -4,     1263,       -4,     1265,       -4,
-    1267,       -4,     1269,       -4,  // NOLINT
+    1235,       -4,     1237,       -4,     1239,       -4,
+    1241,       -4,     1243,       -4,     1245,       -4,
+    1247,       -4,     1249,       -4,     1251,       -4,
+    1253,       -4,     1255,       -4,     1257,       -4,
+    1259,       -4,     1261,       -4,     1263,       -4,
+    1265,       -4,     1267,       -4,     1269,       -4,
     1271,       -4,     1273,       -4,     1275,       -4,
     1277,       -4,     1279,       -4,     1281,       -4,
-    1283,       -4,     1285,       -4,  // NOLINT
-    1287,       -4,     1289,       -4,     1291,       -4,
-    1293,       -4,     1295,       -4,     1297,       -4,
-    1299,       -4,     1301,       -4,  // NOLINT
-    1303,       -4,     1305,       -4,     1307,       -4,
-    1309,       -4,     1311,       -4,     1313,       -4,
-    1315,       -4,     1317,       -4,  // NOLINT
+    1283,       -4,     1285,       -4,     1287,       -4,
+    1289,       -4,     1291,       -4,     1293,       -4,
+    1295,       -4,     1297,       -4,     1299,       -4,
+    1301,       -4,     1303,       -4,     1305,       -4,
+    1307,       -4,     1309,       -4,     1311,       -4,
+    1313,       -4,     1315,       -4,     1317,       -4,
     1319,       -4,     1321,       -4,     1323,       -4,
     1325,       -4,     1327,       -4,     1073743201, -192,
-    1414,       -192,   1415,       21,  // NOLINT
-    7545,       141328, 7549,       15256,  7681,       -4,
-    7683,       -4,     7685,       -4,     7687,       -4,
-    7689,       -4,     7691,       -4,  // NOLINT
-    7693,       -4,     7695,       -4,     7697,       -4,
-    7699,       -4,     7701,       -4,     7703,       -4,
-    7705,       -4,     7707,       -4,  // NOLINT
+    1414,       -192,   1415,       21,     7545,       141328,
+    7549,       15256,  7681,       -4,     7683,       -4,
+    7685,       -4,     7687,       -4,     7689,       -4,
+    7691,       -4,     7693,       -4,     7695,       -4,
+    7697,       -4,     7699,       -4,     7701,       -4,
+    7703,       -4,     7705,       -4,     7707,       -4,
     7709,       -4,     7711,       -4,     7713,       -4,
     7715,       -4,     7717,       -4,     7719,       -4,
-    7721,       -4,     7723,       -4,  // NOLINT
-    7725,       -4,     7727,       -4,     7729,       -4,
-    7731,       -4,     7733,       -4,     7735,       -4,
-    7737,       -4,     7739,       -4,  // NOLINT
-    7741,       -4,     7743,       -4,     7745,       -4,
-    7747,       -4,     7749,       -4,     7751,       -4,
-    7753,       -4,     7755,       -4,  // NOLINT
+    7721,       -4,     7723,       -4,     7725,       -4,
+    7727,       -4,     7729,       -4,     7731,       -4,
+    7733,       -4,     7735,       -4,     7737,       -4,
+    7739,       -4,     7741,       -4,     7743,       -4,
+    7745,       -4,     7747,       -4,     7749,       -4,
+    7751,       -4,     7753,       -4,     7755,       -4,
     7757,       -4,     7759,       -4,     7761,       -4,
     7763,       -4,     7765,       -4,     7767,       -4,
-    7769,       -4,     7771,       -4,  // NOLINT
-    7773,       -4,     7775,       -4,     7777,       -4,
-    7779,       -4,     7781,       -4,     7783,       -4,
-    7785,       -4,     7787,       -4,  // NOLINT
-    7789,       -4,     7791,       -4,     7793,       -4,
-    7795,       -4,     7797,       -4,     7799,       -4,
-    7801,       -4,     7803,       -4,  // NOLINT
+    7769,       -4,     7771,       -4,     7773,       -4,
+    7775,       -4,     7777,       -4,     7779,       -4,
+    7781,       -4,     7783,       -4,     7785,       -4,
+    7787,       -4,     7789,       -4,     7791,       -4,
+    7793,       -4,     7795,       -4,     7797,       -4,
+    7799,       -4,     7801,       -4,     7803,       -4,
     7805,       -4,     7807,       -4,     7809,       -4,
     7811,       -4,     7813,       -4,     7815,       -4,
-    7817,       -4,     7819,       -4,  // NOLINT
-    7821,       -4,     7823,       -4,     7825,       -4,
-    7827,       -4,     7829,       -4,     7830,       25,
-    7831,       29,     7832,       33,  // NOLINT
-    7833,       37,     7834,       41,     7835,       -236,
-    7841,       -4,     7843,       -4,     7845,       -4,
-    7847,       -4,     7849,       -4,  // NOLINT
+    7817,       -4,     7819,       -4,     7821,       -4,
+    7823,       -4,     7825,       -4,     7827,       -4,
+    7829,       -4,     7830,       25,     7831,       29,
+    7832,       33,     7833,       37,     7834,       41,
+    7835,       -236,   7841,       -4,     7843,       -4,
+    7845,       -4,     7847,       -4,     7849,       -4,
     7851,       -4,     7853,       -4,     7855,       -4,
     7857,       -4,     7859,       -4,     7861,       -4,
-    7863,       -4,     7865,       -4,  // NOLINT
-    7867,       -4,     7869,       -4,     7871,       -4,
-    7873,       -4,     7875,       -4,     7877,       -4,
-    7879,       -4,     7881,       -4,  // NOLINT
-    7883,       -4,     7885,       -4,     7887,       -4,
-    7889,       -4,     7891,       -4,     7893,       -4,
-    7895,       -4,     7897,       -4,  // NOLINT
+    7863,       -4,     7865,       -4,     7867,       -4,
+    7869,       -4,     7871,       -4,     7873,       -4,
+    7875,       -4,     7877,       -4,     7879,       -4,
+    7881,       -4,     7883,       -4,     7885,       -4,
+    7887,       -4,     7889,       -4,     7891,       -4,
+    7893,       -4,     7895,       -4,     7897,       -4,
     7899,       -4,     7901,       -4,     7903,       -4,
     7905,       -4,     7907,       -4,     7909,       -4,
-    7911,       -4,     7913,       -4,  // NOLINT
-    7915,       -4,     7917,       -4,     7919,       -4,
-    7921,       -4,     7923,       -4,     7925,       -4,
-    7927,       -4,     7929,       -4,  // NOLINT
-    7931,       -4,     7933,       -4,     7935,       -4,
-    1073749760, 32,     7943,       32,     1073749776, 32,
-    7957,       32,     1073749792, 32,  // NOLINT
+    7911,       -4,     7913,       -4,     7915,       -4,
+    7917,       -4,     7919,       -4,     7921,       -4,
+    7923,       -4,     7925,       -4,     7927,       -4,
+    7929,       -4,     7931,       -4,     7933,       -4,
+    7935,       -4,     1073749760, 32,     7943,       32,
+    1073749776, 32,     7957,       32,     1073749792, 32,
     7975,       32,     1073749808, 32,     7991,       32,
     1073749824, 32,     8005,       32,     8016,       45,
-    8017,       32,     8018,       49,  // NOLINT
-    8019,       32,     8020,       53,     8021,       32,
-    8022,       57,     8023,       32,     1073749856, 32,
-    8039,       32,     1073749872, 296,  // NOLINT
-    8049,       296,    1073749874, 344,    8053,       344,
-    1073749878, 400,    8055,       400,    1073749880, 512,
-    8057,       512,    1073749882, 448,  // NOLINT
+    8017,       32,     8018,       49,     8019,       32,
+    8020,       53,     8021,       32,     8022,       57,
+    8023,       32,     1073749856, 32,     8039,       32,
+    1073749872, 296,    8049,       296,    1073749874, 344,
+    8053,       344,    1073749878, 400,    8055,       400,
+    1073749880, 512,    8057,       512,    1073749882, 448,
     8059,       448,    1073749884, 504,    8061,       504,
     8064,       61,     8065,       65,     8066,       69,
-    8067,       73,     8068,       77,  // NOLINT
-    8069,       81,     8070,       85,     8071,       89,
-    8072,       61,     8073,       65,     8074,       69,
-    8075,       73,     8076,       77,  // NOLINT
-    8077,       81,     8078,       85,     8079,       89,
-    8080,       93,     8081,       97,     8082,       101,
-    8083,       105,    8084,       109,  // NOLINT
+    8067,       73,     8068,       77,     8069,       81,
+    8070,       85,     8071,       89,     8072,       61,
+    8073,       65,     8074,       69,     8075,       73,
+    8076,       77,     8077,       81,     8078,       85,
+    8079,       89,     8080,       93,     8081,       97,
+    8082,       101,    8083,       105,    8084,       109,
     8085,       113,    8086,       117,    8087,       121,
     8088,       93,     8089,       97,     8090,       101,
-    8091,       105,    8092,       109,  // NOLINT
-    8093,       113,    8094,       117,    8095,       121,
-    8096,       125,    8097,       129,    8098,       133,
-    8099,       137,    8100,       141,  // NOLINT
-    8101,       145,    8102,       149,    8103,       153,
-    8104,       125,    8105,       129,    8106,       133,
-    8107,       137,    8108,       141,  // NOLINT
+    8091,       105,    8092,       109,    8093,       113,
+    8094,       117,    8095,       121,    8096,       125,
+    8097,       129,    8098,       133,    8099,       137,
+    8100,       141,    8101,       145,    8102,       149,
+    8103,       153,    8104,       125,    8105,       129,
+    8106,       133,    8107,       137,    8108,       141,
     8109,       145,    8110,       149,    8111,       153,
     1073749936, 32,     8113,       32,     8114,       157,
-    8115,       161,    8116,       165,  // NOLINT
-    8118,       169,    8119,       173,    8124,       161,
-    8126,       -28820, 8130,       177,    8131,       181,
-    8132,       185,    8134,       189,  // NOLINT
-    8135,       193,    8140,       181,    1073749968, 32,
-    8145,       32,     8146,       197,    8147,       13,
-    8150,       201,    8151,       205,  // NOLINT
+    8115,       161,    8116,       165,    8118,       169,
+    8119,       173,    8124,       161,    8126,       -28820,
+    8130,       177,    8131,       181,    8132,       185,
+    8134,       189,    8135,       193,    8140,       181,
+    1073749968, 32,     8145,       32,     8146,       197,
+    8147,       13,     8150,       201,    8151,       205,
     1073749984, 32,     8161,       32,     8162,       209,
     8163,       17,     8164,       213,    8165,       28,
-    8166,       217,    8167,       221,  // NOLINT
-    8178,       225,    8179,       229,    8180,       233,
-    8182,       237,    8183,       241,    8188,       229};  // NOLINT
-static const uint16_t kToUppercaseMultiStrings0Size = 62;      // NOLINT
-static const MultiCharacterSpecialCase<1> kToUppercaseMultiStrings1[1] =
-    {                                               // NOLINT
-        {{kSentinel}}};                             // NOLINT
-static const uint16_t kToUppercaseTable1Size = 73;  // NOLINT
+    8166,       217,    8167,       221,    8178,       225,
+    8179,       229,    8180,       233,    8182,       237,
+    8183,       241,    8188,       229};
+static const uint16_t kToUppercaseMultiStrings0Size = 62;
+static const MultiCharacterSpecialCase<1> kToUppercaseMultiStrings1[1] = {
+    {{kSentinel}}};
+static const uint16_t kToUppercaseTable1Size = 73;
 static const int32_t kToUppercaseTable1[146] = {
-    334,        -112,   1073742192, -64,    383,        -64,
-    388,        -4,     1073743056, -104,   1257,       -104,
-    1073744944, -192,   3166,       -192,  // NOLINT
-    3169,       -4,     3173,       -43180, 3174,       -43168,
-    3176,       -4,     3178,       -4,     3180,       -4,
-    3187,       -4,     3190,       -4,  // NOLINT
-    3201,       -4,     3203,       -4,     3205,       -4,
-    3207,       -4,     3209,       -4,     3211,       -4,
-    3213,       -4,     3215,       -4,  // NOLINT
-    3217,       -4,     3219,       -4,     3221,       -4,
-    3223,       -4,     3225,       -4,     3227,       -4,
-    3229,       -4,     3231,       -4,  // NOLINT
-    3233,       -4,     3235,       -4,     3237,       -4,
-    3239,       -4,     3241,       -4,     3243,       -4,
-    3245,       -4,     3247,       -4,  // NOLINT
-    3249,       -4,     3251,       -4,     3253,       -4,
-    3255,       -4,     3257,       -4,     3259,       -4,
-    3261,       -4,     3263,       -4,  // NOLINT
-    3265,       -4,     3267,       -4,     3269,       -4,
-    3271,       -4,     3273,       -4,     3275,       -4,
-    3277,       -4,     3279,       -4,  // NOLINT
-    3281,       -4,     3283,       -4,     3285,       -4,
-    3287,       -4,     3289,       -4,     3291,       -4,
-    3293,       -4,     3295,       -4,  // NOLINT
-    3297,       -4,     3299,       -4,     3308,       -4,
-    3310,       -4,     3315,       -4,     1073745152, -29056,
-    3365,       -29056, 3367,       -29056,               // NOLINT
-    3373,       -29056};                                  // NOLINT
-static const uint16_t kToUppercaseMultiStrings1Size = 1;  // NOLINT
-static const MultiCharacterSpecialCase<1> kToUppercaseMultiStrings5[1] =
-    {                                               // NOLINT
-        {{kSentinel}}};                             // NOLINT
-static const uint16_t kToUppercaseTable5Size = 95;  // NOLINT
-static const int32_t
-    kToUppercaseTable5[190] = {1601, -4, 1603, -4, 1605, -4, 1607, -4, 1609, -4,
-                               1611, -4, 1613, -4, 1615, -4,  // NOLINT
-                               1617, -4, 1619, -4, 1621, -4, 1623, -4, 1625, -4,
-                               1627, -4, 1629, -4, 1631, -4,  // NOLINT
-                               1633, -4, 1635, -4, 1637, -4, 1639, -4, 1641, -4,
-                               1643, -4, 1645, -4, 1665, -4,  // NOLINT
-                               1667, -4, 1669, -4, 1671, -4, 1673, -4, 1675, -4,
-                               1677, -4, 1679, -4, 1681, -4,  // NOLINT
-                               1683, -4, 1685, -4, 1687, -4, 1689, -4, 1691, -4,
-                               1827, -4, 1829, -4, 1831, -4,  // NOLINT
-                               1833, -4, 1835, -4, 1837, -4, 1839, -4, 1843, -4,
-                               1845, -4, 1847, -4, 1849, -4,  // NOLINT
-                               1851, -4, 1853, -4, 1855, -4, 1857, -4, 1859, -4,
-                               1861, -4, 1863, -4, 1865, -4,  // NOLINT
-                               1867, -4, 1869, -4, 1871, -4, 1873, -4, 1875, -4,
-                               1877, -4, 1879, -4, 1881, -4,  // NOLINT
-                               1883, -4, 1885, -4, 1887, -4, 1889, -4, 1891, -4,
-                               1893, -4, 1895, -4, 1897, -4,  // NOLINT
-                               1899, -4, 1901, -4, 1903, -4, 1914, -4, 1916, -4,
-                               1919, -4, 1921, -4, 1923, -4,  // NOLINT
-                               1925, -4, 1927, -4, 1932, -4, 1937, -4, 1939, -4,
-                               1943, -4, 1945, -4, 1947, -4,  // NOLINT
-                               1949, -4, 1951, -4, 1953, -4, 1955, -4, 1957, -4,
-                               1959, -4, 1961, -4};       // NOLINT
-static const uint16_t kToUppercaseMultiStrings5Size = 1;  // NOLINT
-static const MultiCharacterSpecialCase<3> kToUppercaseMultiStrings7[12] =
-    {  // NOLINT
-        {{70, 70, kSentinel}},
-        {{70, 73, kSentinel}},
-        {{70, 76, kSentinel}},
-        {{70, 70, 73}},  // NOLINT
-        {{70, 70, 76}},
-        {{83, 84, kSentinel}},
-        {{1348, 1350, kSentinel}},
-        {{1348, 1333, kSentinel}},  // NOLINT
-        {{1348, 1339, kSentinel}},
-        {{1358, 1350, kSentinel}},
-        {{1348, 1341, kSentinel}},
-        {{kSentinel}}};                             // NOLINT
-static const uint16_t kToUppercaseTable7Size = 14;  // NOLINT
-static const int32_t kToUppercaseTable7[28] =
-    {6912,       1,    6913, 5,   6914, 9,  6915, 13,
-     6916,       17,   6917, 21,  6918, 21, 6931, 25,  // NOLINT
-     6932,       29,   6933, 33,  6934, 37, 6935, 41,
-     1073749825, -128, 8026, -128};                        // NOLINT
-static const uint16_t kToUppercaseMultiStrings7Size = 12;  // NOLINT
+    334,  -112,   1073742192, -64,    383,  -64,   388,  -4, 1073743056, -104,
+    1257, -104,   1073744944, -192,   3166, -192,  3169, -4, 3173,       -43180,
+    3174, -43168, 3176,       -4,     3178, -4,    3180, -4, 3187,       -4,
+    3190, -4,     3201,       -4,     3203, -4,    3205, -4, 3207,       -4,
+    3209, -4,     3211,       -4,     3213, -4,    3215, -4, 3217,       -4,
+    3219, -4,     3221,       -4,     3223, -4,    3225, -4, 3227,       -4,
+    3229, -4,     3231,       -4,     3233, -4,    3235, -4, 3237,       -4,
+    3239, -4,     3241,       -4,     3243, -4,    3245, -4, 3247,       -4,
+    3249, -4,     3251,       -4,     3253, -4,    3255, -4, 3257,       -4,
+    3259, -4,     3261,       -4,     3263, -4,    3265, -4, 3267,       -4,
+    3269, -4,     3271,       -4,     3273, -4,    3275, -4, 3277,       -4,
+    3279, -4,     3281,       -4,     3283, -4,    3285, -4, 3287,       -4,
+    3289, -4,     3291,       -4,     3293, -4,    3295, -4, 3297,       -4,
+    3299, -4,     3308,       -4,     3310, -4,    3315, -4, 1073745152, -29056,
+    3365, -29056, 3367,       -29056, 3373, -29056};
+static const uint16_t kToUppercaseMultiStrings1Size = 1;
+static const MultiCharacterSpecialCase<1> kToUppercaseMultiStrings5[1] = {
+    {{kSentinel}}};
+static const uint16_t kToUppercaseTable5Size = 95;
+static const int32_t kToUppercaseTable5[190] = {
+    1601, -4, 1603, -4, 1605, -4, 1607, -4, 1609, -4, 1611, -4, 1613, -4,
+    1615, -4, 1617, -4, 1619, -4, 1621, -4, 1623, -4, 1625, -4, 1627, -4,
+    1629, -4, 1631, -4, 1633, -4, 1635, -4, 1637, -4, 1639, -4, 1641, -4,
+    1643, -4, 1645, -4, 1665, -4, 1667, -4, 1669, -4, 1671, -4, 1673, -4,
+    1675, -4, 1677, -4, 1679, -4, 1681, -4, 1683, -4, 1685, -4, 1687, -4,
+    1689, -4, 1691, -4, 1827, -4, 1829, -4, 1831, -4, 1833, -4, 1835, -4,
+    1837, -4, 1839, -4, 1843, -4, 1845, -4, 1847, -4, 1849, -4, 1851, -4,
+    1853, -4, 1855, -4, 1857, -4, 1859, -4, 1861, -4, 1863, -4, 1865, -4,
+    1867, -4, 1869, -4, 1871, -4, 1873, -4, 1875, -4, 1877, -4, 1879, -4,
+    1881, -4, 1883, -4, 1885, -4, 1887, -4, 1889, -4, 1891, -4, 1893, -4,
+    1895, -4, 1897, -4, 1899, -4, 1901, -4, 1903, -4, 1914, -4, 1916, -4,
+    1919, -4, 1921, -4, 1923, -4, 1925, -4, 1927, -4, 1932, -4, 1937, -4,
+    1939, -4, 1943, -4, 1945, -4, 1947, -4, 1949, -4, 1951, -4, 1953, -4,
+    1955, -4, 1957, -4, 1959, -4, 1961, -4};
+static const uint16_t kToUppercaseMultiStrings5Size = 1;
+static const MultiCharacterSpecialCase<3> kToUppercaseMultiStrings7[12] = {
+    {{70, 70, kSentinel}},
+    {{70, 73, kSentinel}},
+    {{70, 76, kSentinel}},
+    {{70, 70, 73}},
+    {{70, 70, 76}},
+    {{83, 84, kSentinel}},
+    {{1348, 1350, kSentinel}},
+    {{1348, 1333, kSentinel}},
+    {{1348, 1339, kSentinel}},
+    {{1358, 1350, kSentinel}},
+    {{1348, 1341, kSentinel}},
+    {{kSentinel}}};
+static const uint16_t kToUppercaseTable7Size = 14;
+static const int32_t kToUppercaseTable7[28] = {
+    6912, 1,  6913, 5,  6914,       9,    6915, 13,  6916, 17,
+    6917, 21, 6918, 21, 6931,       25,   6932, 29,  6933, 33,
+    6934, 37, 6935, 41, 1073749825, -128, 8026, -128};
+static const uint16_t kToUppercaseMultiStrings7Size = 12;
 int ToUppercase::Convert(uchar c, uchar n, uchar* result,
                          bool* allow_caching_ptr) {
   int chunk_index = c >> 13;
@@ -1653,269 +1325,221 @@ int ToUppercase::Convert(uchar c, uchar n, uchar* result,
 }
 
 static const MultiCharacterSpecialCase<1> kEcma262CanonicalizeMultiStrings0[1] =
-    {                                                        // NOLINT
-        {{kSentinel}}};                                      // NOLINT
-static const uint16_t kEcma262CanonicalizeTable0Size = 498;  // NOLINT
+    {{{kSentinel}}};
+static const uint16_t kEcma262CanonicalizeTable0Size = 498;
 static const int32_t kEcma262CanonicalizeTable0[996] = {
     1073741921, -128,   122,        -128,   181,        2972,
     1073742048, -128,   246,        -128,   1073742072, -128,
-    254,        -128,   255,        484,  // NOLINT
-    257,        -4,     259,        -4,     261,        -4,
-    263,        -4,     265,        -4,     267,        -4,
-    269,        -4,     271,        -4,  // NOLINT
-    273,        -4,     275,        -4,     277,        -4,
-    279,        -4,     281,        -4,     283,        -4,
-    285,        -4,     287,        -4,  // NOLINT
+    254,        -128,   255,        484,    257,        -4,
+    259,        -4,     261,        -4,     263,        -4,
+    265,        -4,     267,        -4,     269,        -4,
+    271,        -4,     273,        -4,     275,        -4,
+    277,        -4,     279,        -4,     281,        -4,
+    283,        -4,     285,        -4,     287,        -4,
     289,        -4,     291,        -4,     293,        -4,
     295,        -4,     297,        -4,     299,        -4,
-    301,        -4,     303,        -4,  // NOLINT
-    307,        -4,     309,        -4,     311,        -4,
-    314,        -4,     316,        -4,     318,        -4,
-    320,        -4,     322,        -4,  // NOLINT
-    324,        -4,     326,        -4,     328,        -4,
-    331,        -4,     333,        -4,     335,        -4,
-    337,        -4,     339,        -4,  // NOLINT
+    301,        -4,     303,        -4,     307,        -4,
+    309,        -4,     311,        -4,     314,        -4,
+    316,        -4,     318,        -4,     320,        -4,
+    322,        -4,     324,        -4,     326,        -4,
+    328,        -4,     331,        -4,     333,        -4,
+    335,        -4,     337,        -4,     339,        -4,
     341,        -4,     343,        -4,     345,        -4,
     347,        -4,     349,        -4,     351,        -4,
-    353,        -4,     355,        -4,  // NOLINT
-    357,        -4,     359,        -4,     361,        -4,
-    363,        -4,     365,        -4,     367,        -4,
-    369,        -4,     371,        -4,  // NOLINT
-    373,        -4,     375,        -4,     378,        -4,
-    380,        -4,     382,        -4,     384,        780,
-    387,        -4,     389,        -4,  // NOLINT
+    353,        -4,     355,        -4,     357,        -4,
+    359,        -4,     361,        -4,     363,        -4,
+    365,        -4,     367,        -4,     369,        -4,
+    371,        -4,     373,        -4,     375,        -4,
+    378,        -4,     380,        -4,     382,        -4,
+    384,        780,    387,        -4,     389,        -4,
     392,        -4,     396,        -4,     402,        -4,
     405,        388,    409,        -4,     410,        652,
-    414,        520,    417,        -4,  // NOLINT
-    419,        -4,     421,        -4,     424,        -4,
-    429,        -4,     432,        -4,     436,        -4,
-    438,        -4,     441,        -4,  // NOLINT
-    445,        -4,     447,        224,    453,        -4,
-    454,        -8,     456,        -4,     457,        -8,
-    459,        -4,     460,        -8,  // NOLINT
+    414,        520,    417,        -4,     419,        -4,
+    421,        -4,     424,        -4,     429,        -4,
+    432,        -4,     436,        -4,     438,        -4,
+    441,        -4,     445,        -4,     447,        224,
+    453,        -4,     454,        -8,     456,        -4,
+    457,        -8,     459,        -4,     460,        -8,
     462,        -4,     464,        -4,     466,        -4,
     468,        -4,     470,        -4,     472,        -4,
-    474,        -4,     476,        -4,  // NOLINT
-    477,        -316,   479,        -4,     481,        -4,
-    483,        -4,     485,        -4,     487,        -4,
-    489,        -4,     491,        -4,  // NOLINT
-    493,        -4,     495,        -4,     498,        -4,
-    499,        -8,     501,        -4,     505,        -4,
-    507,        -4,     509,        -4,  // NOLINT
+    474,        -4,     476,        -4,     477,        -316,
+    479,        -4,     481,        -4,     483,        -4,
+    485,        -4,     487,        -4,     489,        -4,
+    491,        -4,     493,        -4,     495,        -4,
+    498,        -4,     499,        -8,     501,        -4,
+    505,        -4,     507,        -4,     509,        -4,
     511,        -4,     513,        -4,     515,        -4,
     517,        -4,     519,        -4,     521,        -4,
-    523,        -4,     525,        -4,  // NOLINT
-    527,        -4,     529,        -4,     531,        -4,
-    533,        -4,     535,        -4,     537,        -4,
-    539,        -4,     541,        -4,  // NOLINT
-    543,        -4,     547,        -4,     549,        -4,
-    551,        -4,     553,        -4,     555,        -4,
-    557,        -4,     559,        -4,  // NOLINT
+    523,        -4,     525,        -4,     527,        -4,
+    529,        -4,     531,        -4,     533,        -4,
+    535,        -4,     537,        -4,     539,        -4,
+    541,        -4,     543,        -4,     547,        -4,
+    549,        -4,     551,        -4,     553,        -4,
+    555,        -4,     557,        -4,     559,        -4,
     561,        -4,     563,        -4,     572,        -4,
     1073742399, 43260,  576,        43260,  578,        -4,
-    583,        -4,     585,        -4,  // NOLINT
-    587,        -4,     589,        -4,     591,        -4,
-    592,        43132,  593,        43120,  594,        43128,
-    595,        -840,   596,        -824,  // NOLINT
-    1073742422, -820,   599,        -820,   601,        -808,
-    603,        -812,   604,        169276, 608,        -820,
-    609,        169260, 611,        -828,  // NOLINT
+    583,        -4,     585,        -4,     587,        -4,
+    589,        -4,     591,        -4,     592,        43132,
+    593,        43120,  594,        43128,  595,        -840,
+    596,        -824,   1073742422, -820,   599,        -820,
+    601,        -808,   603,        -812,   604,        169276,
+    608,        -820,   609,        169260, 611,        -828,
     613,        169120, 614,        169232, 616,        -836,
     617,        -844,   619,        42972,  620,        169220,
-    623,        -844,   625,        42996,  // NOLINT
-    626,        -852,   629,        -856,   637,        42908,
-    640,        -872,   643,        -872,   647,        169128,
-    648,        -872,   649,        -276,  // NOLINT
-    1073742474, -868,   651,        -868,   652,        -284,
-    658,        -876,   670,        169032, 837,        336,
-    881,        -4,     883,        -4,  // NOLINT
+    623,        -844,   625,        42996,  626,        -852,
+    629,        -856,   637,        42908,  640,        -872,
+    643,        -872,   647,        169128, 648,        -872,
+    649,        -276,   1073742474, -868,   651,        -868,
+    652,        -284,   658,        -876,   670,        169032,
+    837,        336,    881,        -4,     883,        -4,
     887,        -4,     1073742715, 520,    893,        520,
     940,        -152,   1073742765, -148,   943,        -148,
-    1073742769, -128,   961,        -128,  // NOLINT
-    962,        -124,   1073742787, -128,   971,        -128,
-    972,        -256,   1073742797, -252,   974,        -252,
-    976,        -248,   977,        -228,  // NOLINT
-    981,        -188,   982,        -216,   983,        -32,
-    985,        -4,     987,        -4,     989,        -4,
-    991,        -4,     993,        -4,  // NOLINT
+    1073742769, -128,   961,        -128,   962,        -124,
+    1073742787, -128,   971,        -128,   972,        -256,
+    1073742797, -252,   974,        -252,   976,        -248,
+    977,        -228,   981,        -188,   982,        -216,
+    983,        -32,    985,        -4,     987,        -4,
+    989,        -4,     991,        -4,     993,        -4,
     995,        -4,     997,        -4,     999,        -4,
     1001,       -4,     1003,       -4,     1005,       -4,
-    1007,       -4,     1008,       -344,  // NOLINT
-    1009,       -320,   1010,       28,     1011,       -464,
-    1013,       -384,   1016,       -4,     1019,       -4,
-    1073742896, -128,   1103,       -128,  // NOLINT
-    1073742928, -320,   1119,       -320,   1121,       -4,
-    1123,       -4,     1125,       -4,     1127,       -4,
-    1129,       -4,     1131,       -4,  // NOLINT
+    1007,       -4,     1008,       -344,   1009,       -320,
+    1010,       28,     1011,       -464,   1013,       -384,
+    1016,       -4,     1019,       -4,     1073742896, -128,
+    1103,       -128,   1073742928, -320,   1119,       -320,
+    1121,       -4,     1123,       -4,     1125,       -4,
+    1127,       -4,     1129,       -4,     1131,       -4,
     1133,       -4,     1135,       -4,     1137,       -4,
     1139,       -4,     1141,       -4,     1143,       -4,
-    1145,       -4,     1147,       -4,  // NOLINT
-    1149,       -4,     1151,       -4,     1153,       -4,
-    1163,       -4,     1165,       -4,     1167,       -4,
-    1169,       -4,     1171,       -4,  // NOLINT
-    1173,       -4,     1175,       -4,     1177,       -4,
-    1179,       -4,     1181,       -4,     1183,       -4,
-    1185,       -4,     1187,       -4,  // NOLINT
+    1145,       -4,     1147,       -4,     1149,       -4,
+    1151,       -4,     1153,       -4,     1163,       -4,
+    1165,       -4,     1167,       -4,     1169,       -4,
+    1171,       -4,     1173,       -4,     1175,       -4,
+    1177,       -4,     1179,       -4,     1181,       -4,
+    1183,       -4,     1185,       -4,     1187,       -4,
     1189,       -4,     1191,       -4,     1193,       -4,
     1195,       -4,     1197,       -4,     1199,       -4,
-    1201,       -4,     1203,       -4,  // NOLINT
-    1205,       -4,     1207,       -4,     1209,       -4,
-    1211,       -4,     1213,       -4,     1215,       -4,
-    1218,       -4,     1220,       -4,  // NOLINT
-    1222,       -4,     1224,       -4,     1226,       -4,
-    1228,       -4,     1230,       -4,     1231,       -60,
-    1233,       -4,     1235,       -4,  // NOLINT
+    1201,       -4,     1203,       -4,     1205,       -4,
+    1207,       -4,     1209,       -4,     1211,       -4,
+    1213,       -4,     1215,       -4,     1218,       -4,
+    1220,       -4,     1222,       -4,     1224,       -4,
+    1226,       -4,     1228,       -4,     1230,       -4,
+    1231,       -60,    1233,       -4,     1235,       -4,
     1237,       -4,     1239,       -4,     1241,       -4,
     1243,       -4,     1245,       -4,     1247,       -4,
-    1249,       -4,     1251,       -4,  // NOLINT
-    1253,       -4,     1255,       -4,     1257,       -4,
-    1259,       -4,     1261,       -4,     1263,       -4,
-    1265,       -4,     1267,       -4,  // NOLINT
-    1269,       -4,     1271,       -4,     1273,       -4,
-    1275,       -4,     1277,       -4,     1279,       -4,
-    1281,       -4,     1283,       -4,  // NOLINT
+    1249,       -4,     1251,       -4,     1253,       -4,
+    1255,       -4,     1257,       -4,     1259,       -4,
+    1261,       -4,     1263,       -4,     1265,       -4,
+    1267,       -4,     1269,       -4,     1271,       -4,
+    1273,       -4,     1275,       -4,     1277,       -4,
+    1279,       -4,     1281,       -4,     1283,       -4,
     1285,       -4,     1287,       -4,     1289,       -4,
     1291,       -4,     1293,       -4,     1295,       -4,
-    1297,       -4,     1299,       -4,  // NOLINT
-    1301,       -4,     1303,       -4,     1305,       -4,
-    1307,       -4,     1309,       -4,     1311,       -4,
-    1313,       -4,     1315,       -4,  // NOLINT
-    1317,       -4,     1319,       -4,     1321,       -4,
-    1323,       -4,     1325,       -4,     1327,       -4,
-    1073743201, -192,   1414,       -192,  // NOLINT
+    1297,       -4,     1299,       -4,     1301,       -4,
+    1303,       -4,     1305,       -4,     1307,       -4,
+    1309,       -4,     1311,       -4,     1313,       -4,
+    1315,       -4,     1317,       -4,     1319,       -4,
+    1321,       -4,     1323,       -4,     1325,       -4,
+    1327,       -4,     1073743201, -192,   1414,       -192,
     7545,       141328, 7549,       15256,  7681,       -4,
     7683,       -4,     7685,       -4,     7687,       -4,
-    7689,       -4,     7691,       -4,  // NOLINT
-    7693,       -4,     7695,       -4,     7697,       -4,
-    7699,       -4,     7701,       -4,     7703,       -4,
-    7705,       -4,     7707,       -4,  // NOLINT
-    7709,       -4,     7711,       -4,     7713,       -4,
-    7715,       -4,     7717,       -4,     7719,       -4,
-    7721,       -4,     7723,       -4,  // NOLINT
+    7689,       -4,     7691,       -4,     7693,       -4,
+    7695,       -4,     7697,       -4,     7699,       -4,
+    7701,       -4,     7703,       -4,     7705,       -4,
+    7707,       -4,     7709,       -4,     7711,       -4,
+    7713,       -4,     7715,       -4,     7717,       -4,
+    7719,       -4,     7721,       -4,     7723,       -4,
     7725,       -4,     7727,       -4,     7729,       -4,
     7731,       -4,     7733,       -4,     7735,       -4,
-    7737,       -4,     7739,       -4,  // NOLINT
-    7741,       -4,     7743,       -4,     7745,       -4,
-    7747,       -4,     7749,       -4,     7751,       -4,
-    7753,       -4,     7755,       -4,  // NOLINT
-    7757,       -4,     7759,       -4,     7761,       -4,
-    7763,       -4,     7765,       -4,     7767,       -4,
-    7769,       -4,     7771,       -4,  // NOLINT
+    7737,       -4,     7739,       -4,     7741,       -4,
+    7743,       -4,     7745,       -4,     7747,       -4,
+    7749,       -4,     7751,       -4,     7753,       -4,
+    7755,       -4,     7757,       -4,     7759,       -4,
+    7761,       -4,     7763,       -4,     7765,       -4,
+    7767,       -4,     7769,       -4,     7771,       -4,
     7773,       -4,     7775,       -4,     7777,       -4,
     7779,       -4,     7781,       -4,     7783,       -4,
-    7785,       -4,     7787,       -4,  // NOLINT
-    7789,       -4,     7791,       -4,     7793,       -4,
-    7795,       -4,     7797,       -4,     7799,       -4,
-    7801,       -4,     7803,       -4,  // NOLINT
-    7805,       -4,     7807,       -4,     7809,       -4,
-    7811,       -4,     7813,       -4,     7815,       -4,
-    7817,       -4,     7819,       -4,  // NOLINT
+    7785,       -4,     7787,       -4,     7789,       -4,
+    7791,       -4,     7793,       -4,     7795,       -4,
+    7797,       -4,     7799,       -4,     7801,       -4,
+    7803,       -4,     7805,       -4,     7807,       -4,
+    7809,       -4,     7811,       -4,     7813,       -4,
+    7815,       -4,     7817,       -4,     7819,       -4,
     7821,       -4,     7823,       -4,     7825,       -4,
     7827,       -4,     7829,       -4,     7835,       -236,
-    7841,       -4,     7843,       -4,  // NOLINT
-    7845,       -4,     7847,       -4,     7849,       -4,
-    7851,       -4,     7853,       -4,     7855,       -4,
-    7857,       -4,     7859,       -4,  // NOLINT
-    7861,       -4,     7863,       -4,     7865,       -4,
-    7867,       -4,     7869,       -4,     7871,       -4,
-    7873,       -4,     7875,       -4,  // NOLINT
+    7841,       -4,     7843,       -4,     7845,       -4,
+    7847,       -4,     7849,       -4,     7851,       -4,
+    7853,       -4,     7855,       -4,     7857,       -4,
+    7859,       -4,     7861,       -4,     7863,       -4,
+    7865,       -4,     7867,       -4,     7869,       -4,
+    7871,       -4,     7873,       -4,     7875,       -4,
     7877,       -4,     7879,       -4,     7881,       -4,
     7883,       -4,     7885,       -4,     7887,       -4,
-    7889,       -4,     7891,       -4,  // NOLINT
-    7893,       -4,     7895,       -4,     7897,       -4,
-    7899,       -4,     7901,       -4,     7903,       -4,
-    7905,       -4,     7907,       -4,  // NOLINT
-    7909,       -4,     7911,       -4,     7913,       -4,
-    7915,       -4,     7917,       -4,     7919,       -4,
-    7921,       -4,     7923,       -4,  // NOLINT
+    7889,       -4,     7891,       -4,     7893,       -4,
+    7895,       -4,     7897,       -4,     7899,       -4,
+    7901,       -4,     7903,       -4,     7905,       -4,
+    7907,       -4,     7909,       -4,     7911,       -4,
+    7913,       -4,     7915,       -4,     7917,       -4,
+    7919,       -4,     7921,       -4,     7923,       -4,
     7925,       -4,     7927,       -4,     7929,       -4,
     7931,       -4,     7933,       -4,     7935,       -4,
-    1073749760, 32,     7943,       32,  // NOLINT
-    1073749776, 32,     7957,       32,     1073749792, 32,
-    7975,       32,     1073749808, 32,     7991,       32,
-    1073749824, 32,     8005,       32,  // NOLINT
-    8017,       32,     8019,       32,     8021,       32,
-    8023,       32,     1073749856, 32,     8039,       32,
-    1073749872, 296,    8049,       296,  // NOLINT
+    1073749760, 32,     7943,       32,     1073749776, 32,
+    7957,       32,     1073749792, 32,     7975,       32,
+    1073749808, 32,     7991,       32,     1073749824, 32,
+    8005,       32,     8017,       32,     8019,       32,
+    8021,       32,     8023,       32,     1073749856, 32,
+    8039,       32,     1073749872, 296,    8049,       296,
     1073749874, 344,    8053,       344,    1073749878, 400,
     8055,       400,    1073749880, 512,    8057,       512,
-    1073749882, 448,    8059,       448,  // NOLINT
-    1073749884, 504,    8061,       504,    1073749936, 32,
-    8113,       32,     8126,       -28820, 1073749968, 32,
-    8145,       32,     1073749984, 32,                           // NOLINT
-    8161,       32,     8165,       28};                          // NOLINT
-static const uint16_t kEcma262CanonicalizeMultiStrings0Size = 1;  // NOLINT
+    1073749882, 448,    8059,       448,    1073749884, 504,
+    8061,       504,    1073749936, 32,     8113,       32,
+    8126,       -28820, 1073749968, 32,     8145,       32,
+    1073749984, 32,     8161,       32,     8165,       28};
+static const uint16_t kEcma262CanonicalizeMultiStrings0Size = 1;
 static const MultiCharacterSpecialCase<1> kEcma262CanonicalizeMultiStrings1[1] =
-    {                                                       // NOLINT
-        {{kSentinel}}};                                     // NOLINT
-static const uint16_t kEcma262CanonicalizeTable1Size = 73;  // NOLINT
+    {{{kSentinel}}};
+static const uint16_t kEcma262CanonicalizeTable1Size = 73;
 static const int32_t kEcma262CanonicalizeTable1[146] = {
-    334,        -112,   1073742192, -64,    383,        -64,
-    388,        -4,     1073743056, -104,   1257,       -104,
-    1073744944, -192,   3166,       -192,  // NOLINT
-    3169,       -4,     3173,       -43180, 3174,       -43168,
-    3176,       -4,     3178,       -4,     3180,       -4,
-    3187,       -4,     3190,       -4,  // NOLINT
-    3201,       -4,     3203,       -4,     3205,       -4,
-    3207,       -4,     3209,       -4,     3211,       -4,
-    3213,       -4,     3215,       -4,  // NOLINT
-    3217,       -4,     3219,       -4,     3221,       -4,
-    3223,       -4,     3225,       -4,     3227,       -4,
-    3229,       -4,     3231,       -4,  // NOLINT
-    3233,       -4,     3235,       -4,     3237,       -4,
-    3239,       -4,     3241,       -4,     3243,       -4,
-    3245,       -4,     3247,       -4,  // NOLINT
-    3249,       -4,     3251,       -4,     3253,       -4,
-    3255,       -4,     3257,       -4,     3259,       -4,
-    3261,       -4,     3263,       -4,  // NOLINT
-    3265,       -4,     3267,       -4,     3269,       -4,
-    3271,       -4,     3273,       -4,     3275,       -4,
-    3277,       -4,     3279,       -4,  // NOLINT
-    3281,       -4,     3283,       -4,     3285,       -4,
-    3287,       -4,     3289,       -4,     3291,       -4,
-    3293,       -4,     3295,       -4,  // NOLINT
-    3297,       -4,     3299,       -4,     3308,       -4,
-    3310,       -4,     3315,       -4,     1073745152, -29056,
-    3365,       -29056, 3367,       -29056,                       // NOLINT
-    3373,       -29056};                                          // NOLINT
-static const uint16_t kEcma262CanonicalizeMultiStrings1Size = 1;  // NOLINT
+    334,  -112,   1073742192, -64,    383,  -64,   388,  -4, 1073743056, -104,
+    1257, -104,   1073744944, -192,   3166, -192,  3169, -4, 3173,       -43180,
+    3174, -43168, 3176,       -4,     3178, -4,    3180, -4, 3187,       -4,
+    3190, -4,     3201,       -4,     3203, -4,    3205, -4, 3207,       -4,
+    3209, -4,     3211,       -4,     3213, -4,    3215, -4, 3217,       -4,
+    3219, -4,     3221,       -4,     3223, -4,    3225, -4, 3227,       -4,
+    3229, -4,     3231,       -4,     3233, -4,    3235, -4, 3237,       -4,
+    3239, -4,     3241,       -4,     3243, -4,    3245, -4, 3247,       -4,
+    3249, -4,     3251,       -4,     3253, -4,    3255, -4, 3257,       -4,
+    3259, -4,     3261,       -4,     3263, -4,    3265, -4, 3267,       -4,
+    3269, -4,     3271,       -4,     3273, -4,    3275, -4, 3277,       -4,
+    3279, -4,     3281,       -4,     3283, -4,    3285, -4, 3287,       -4,
+    3289, -4,     3291,       -4,     3293, -4,    3295, -4, 3297,       -4,
+    3299, -4,     3308,       -4,     3310, -4,    3315, -4, 1073745152, -29056,
+    3365, -29056, 3367,       -29056, 3373, -29056};
+static const uint16_t kEcma262CanonicalizeMultiStrings1Size = 1;
 static const MultiCharacterSpecialCase<1> kEcma262CanonicalizeMultiStrings5[1] =
-    {                                                       // NOLINT
-        {{kSentinel}}};                                     // NOLINT
-static const uint16_t kEcma262CanonicalizeTable5Size = 95;  // NOLINT
+    {{{kSentinel}}};
+static const uint16_t kEcma262CanonicalizeTable5Size = 95;
 static const int32_t kEcma262CanonicalizeTable5[190] = {
-        1601, -4, 1603, -4, 1605, -4, 1607, -4,
-        1609, -4, 1611, -4, 1613, -4, 1615, -4,  // NOLINT
-        1617, -4, 1619, -4, 1621, -4, 1623, -4,
-        1625, -4, 1627, -4, 1629, -4, 1631, -4,  // NOLINT
-        1633, -4, 1635, -4, 1637, -4, 1639, -4,
-        1641, -4, 1643, -4, 1645, -4, 1665, -4,  // NOLINT
-        1667, -4, 1669, -4, 1671, -4, 1673, -4,
-        1675, -4, 1677, -4, 1679, -4, 1681, -4,  // NOLINT
-        1683, -4, 1685, -4, 1687, -4, 1689, -4,
-        1691, -4, 1827, -4, 1829, -4, 1831, -4,  // NOLINT
-        1833, -4, 1835, -4, 1837, -4, 1839, -4,
-        1843, -4, 1845, -4, 1847, -4, 1849, -4,  // NOLINT
-        1851, -4, 1853, -4, 1855, -4, 1857, -4,
-        1859, -4, 1861, -4, 1863, -4, 1865, -4,  // NOLINT
-        1867, -4, 1869, -4, 1871, -4, 1873, -4,
-        1875, -4, 1877, -4, 1879, -4, 1881, -4,  // NOLINT
-        1883, -4, 1885, -4, 1887, -4, 1889, -4,
-        1891, -4, 1893, -4, 1895, -4, 1897, -4,  // NOLINT
-        1899, -4, 1901, -4, 1903, -4, 1914, -4,
-        1916, -4, 1919, -4, 1921, -4, 1923, -4,  // NOLINT
-        1925, -4, 1927, -4, 1932, -4, 1937, -4,
-        1939, -4, 1943, -4, 1945, -4, 1947, -4,  // NOLINT
-        1949, -4, 1951, -4, 1953, -4, 1955, -4,
-        1957, -4, 1959, -4, 1961, -4};                            // NOLINT
-static const uint16_t kEcma262CanonicalizeMultiStrings5Size = 1;  // NOLINT
+    1601, -4, 1603, -4, 1605, -4, 1607, -4, 1609, -4, 1611, -4, 1613, -4,
+    1615, -4, 1617, -4, 1619, -4, 1621, -4, 1623, -4, 1625, -4, 1627, -4,
+    1629, -4, 1631, -4, 1633, -4, 1635, -4, 1637, -4, 1639, -4, 1641, -4,
+    1643, -4, 1645, -4, 1665, -4, 1667, -4, 1669, -4, 1671, -4, 1673, -4,
+    1675, -4, 1677, -4, 1679, -4, 1681, -4, 1683, -4, 1685, -4, 1687, -4,
+    1689, -4, 1691, -4, 1827, -4, 1829, -4, 1831, -4, 1833, -4, 1835, -4,
+    1837, -4, 1839, -4, 1843, -4, 1845, -4, 1847, -4, 1849, -4, 1851, -4,
+    1853, -4, 1855, -4, 1857, -4, 1859, -4, 1861, -4, 1863, -4, 1865, -4,
+    1867, -4, 1869, -4, 1871, -4, 1873, -4, 1875, -4, 1877, -4, 1879, -4,
+    1881, -4, 1883, -4, 1885, -4, 1887, -4, 1889, -4, 1891, -4, 1893, -4,
+    1895, -4, 1897, -4, 1899, -4, 1901, -4, 1903, -4, 1914, -4, 1916, -4,
+    1919, -4, 1921, -4, 1923, -4, 1925, -4, 1927, -4, 1932, -4, 1937, -4,
+    1939, -4, 1943, -4, 1945, -4, 1947, -4, 1949, -4, 1951, -4, 1953, -4,
+    1955, -4, 1957, -4, 1959, -4, 1961, -4};
+static const uint16_t kEcma262CanonicalizeMultiStrings5Size = 1;
 static const MultiCharacterSpecialCase<1> kEcma262CanonicalizeMultiStrings7[1] =
-    {                                                      // NOLINT
-        {{kSentinel}}};                                    // NOLINT
-static const uint16_t kEcma262CanonicalizeTable7Size = 2;  // NOLINT
+    {{{kSentinel}}};
+static const uint16_t kEcma262CanonicalizeTable7Size = 2;
 static const int32_t kEcma262CanonicalizeTable7[4] = {1073749825, -128, 8026,
-                                                      -128};      // NOLINT
-static const uint16_t kEcma262CanonicalizeMultiStrings7Size = 1;  // NOLINT
+                                                      -128};
+static const uint16_t kEcma262CanonicalizeMultiStrings7Size = 1;
 int Ecma262Canonicalize::Convert(uchar c, uchar n, uchar* result,
                                  bool* allow_caching_ptr) {
   int chunk_index = c >> 13;
@@ -1942,1095 +1566,899 @@ int Ecma262Canonicalize::Convert(uchar c, uchar n, uchar* result,
 }
 
 static const MultiCharacterSpecialCase<4>
-    kEcma262UnCanonicalizeMultiStrings0[507] = {  // NOLINT
-        {{65, 97, kSentinel}},
-        {{90, 122, kSentinel}},
-        {{181, 924, 956, kSentinel}},
-        {{192, 224, kSentinel}},  // NOLINT
-        {{214, 246, kSentinel}},
-        {{216, 248, kSentinel}},
-        {{222, 254, kSentinel}},
-        {{255, 376, kSentinel}},  // NOLINT
-        {{256, 257, kSentinel}},
-        {{258, 259, kSentinel}},
-        {{260, 261, kSentinel}},
-        {{262, 263, kSentinel}},  // NOLINT
-        {{264, 265, kSentinel}},
-        {{266, 267, kSentinel}},
-        {{268, 269, kSentinel}},
-        {{270, 271, kSentinel}},  // NOLINT
-        {{272, 273, kSentinel}},
-        {{274, 275, kSentinel}},
-        {{276, 277, kSentinel}},
-        {{278, 279, kSentinel}},  // NOLINT
-        {{280, 281, kSentinel}},
-        {{282, 283, kSentinel}},
-        {{284, 285, kSentinel}},
-        {{286, 287, kSentinel}},  // NOLINT
-        {{288, 289, kSentinel}},
-        {{290, 291, kSentinel}},
-        {{292, 293, kSentinel}},
-        {{294, 295, kSentinel}},  // NOLINT
-        {{296, 297, kSentinel}},
-        {{298, 299, kSentinel}},
-        {{300, 301, kSentinel}},
-        {{302, 303, kSentinel}},  // NOLINT
-        {{306, 307, kSentinel}},
-        {{308, 309, kSentinel}},
-        {{310, 311, kSentinel}},
-        {{313, 314, kSentinel}},  // NOLINT
-        {{315, 316, kSentinel}},
-        {{317, 318, kSentinel}},
-        {{319, 320, kSentinel}},
-        {{321, 322, kSentinel}},  // NOLINT
-        {{323, 324, kSentinel}},
-        {{325, 326, kSentinel}},
-        {{327, 328, kSentinel}},
-        {{330, 331, kSentinel}},  // NOLINT
-        {{332, 333, kSentinel}},
-        {{334, 335, kSentinel}},
-        {{336, 337, kSentinel}},
-        {{338, 339, kSentinel}},  // NOLINT
-        {{340, 341, kSentinel}},
-        {{342, 343, kSentinel}},
-        {{344, 345, kSentinel}},
-        {{346, 347, kSentinel}},  // NOLINT
-        {{348, 349, kSentinel}},
-        {{350, 351, kSentinel}},
-        {{352, 353, kSentinel}},
-        {{354, 355, kSentinel}},  // NOLINT
-        {{356, 357, kSentinel}},
-        {{358, 359, kSentinel}},
-        {{360, 361, kSentinel}},
-        {{362, 363, kSentinel}},  // NOLINT
-        {{364, 365, kSentinel}},
-        {{366, 367, kSentinel}},
-        {{368, 369, kSentinel}},
-        {{370, 371, kSentinel}},  // NOLINT
-        {{372, 373, kSentinel}},
-        {{374, 375, kSentinel}},
-        {{377, 378, kSentinel}},
-        {{379, 380, kSentinel}},  // NOLINT
-        {{381, 382, kSentinel}},
-        {{384, 579, kSentinel}},
-        {{385, 595, kSentinel}},
-        {{386, 387, kSentinel}},  // NOLINT
-        {{388, 389, kSentinel}},
-        {{390, 596, kSentinel}},
-        {{391, 392, kSentinel}},
-        {{393, 598, kSentinel}},  // NOLINT
-        {{394, 599, kSentinel}},
-        {{395, 396, kSentinel}},
-        {{398, 477, kSentinel}},
-        {{399, 601, kSentinel}},  // NOLINT
-        {{400, 603, kSentinel}},
-        {{401, 402, kSentinel}},
-        {{403, 608, kSentinel}},
-        {{404, 611, kSentinel}},  // NOLINT
-        {{405, 502, kSentinel}},
-        {{406, 617, kSentinel}},
-        {{407, 616, kSentinel}},
-        {{408, 409, kSentinel}},  // NOLINT
-        {{410, 573, kSentinel}},
-        {{412, 623, kSentinel}},
-        {{413, 626, kSentinel}},
-        {{414, 544, kSentinel}},  // NOLINT
-        {{415, 629, kSentinel}},
-        {{416, 417, kSentinel}},
-        {{418, 419, kSentinel}},
-        {{420, 421, kSentinel}},  // NOLINT
-        {{422, 640, kSentinel}},
-        {{423, 424, kSentinel}},
-        {{425, 643, kSentinel}},
-        {{428, 429, kSentinel}},  // NOLINT
-        {{430, 648, kSentinel}},
-        {{431, 432, kSentinel}},
-        {{433, 650, kSentinel}},
-        {{434, 651, kSentinel}},  // NOLINT
-        {{435, 436, kSentinel}},
-        {{437, 438, kSentinel}},
-        {{439, 658, kSentinel}},
-        {{440, 441, kSentinel}},  // NOLINT
-        {{444, 445, kSentinel}},
-        {{447, 503, kSentinel}},
-        {{452, 453, 454, kSentinel}},
-        {{455, 456, 457, kSentinel}},  // NOLINT
-        {{458, 459, 460, kSentinel}},
-        {{461, 462, kSentinel}},
-        {{463, 464, kSentinel}},
-        {{465, 466, kSentinel}},  // NOLINT
-        {{467, 468, kSentinel}},
-        {{469, 470, kSentinel}},
-        {{471, 472, kSentinel}},
-        {{473, 474, kSentinel}},  // NOLINT
-        {{475, 476, kSentinel}},
-        {{478, 479, kSentinel}},
-        {{480, 481, kSentinel}},
-        {{482, 483, kSentinel}},  // NOLINT
-        {{484, 485, kSentinel}},
-        {{486, 487, kSentinel}},
-        {{488, 489, kSentinel}},
-        {{490, 491, kSentinel}},  // NOLINT
-        {{492, 493, kSentinel}},
-        {{494, 495, kSentinel}},
-        {{497, 498, 499, kSentinel}},
-        {{500, 501, kSentinel}},  // NOLINT
-        {{504, 505, kSentinel}},
-        {{506, 507, kSentinel}},
-        {{508, 509, kSentinel}},
-        {{510, 511, kSentinel}},  // NOLINT
-        {{512, 513, kSentinel}},
-        {{514, 515, kSentinel}},
-        {{516, 517, kSentinel}},
-        {{518, 519, kSentinel}},  // NOLINT
-        {{520, 521, kSentinel}},
-        {{522, 523, kSentinel}},
-        {{524, 525, kSentinel}},
-        {{526, 527, kSentinel}},  // NOLINT
-        {{528, 529, kSentinel}},
-        {{530, 531, kSentinel}},
-        {{532, 533, kSentinel}},
-        {{534, 535, kSentinel}},  // NOLINT
-        {{536, 537, kSentinel}},
-        {{538, 539, kSentinel}},
-        {{540, 541, kSentinel}},
-        {{542, 543, kSentinel}},  // NOLINT
-        {{546, 547, kSentinel}},
-        {{548, 549, kSentinel}},
-        {{550, 551, kSentinel}},
-        {{552, 553, kSentinel}},  // NOLINT
-        {{554, 555, kSentinel}},
-        {{556, 557, kSentinel}},
-        {{558, 559, kSentinel}},
-        {{560, 561, kSentinel}},  // NOLINT
-        {{562, 563, kSentinel}},
-        {{570, 11365, kSentinel}},
-        {{571, 572, kSentinel}},
-        {{574, 11366, kSentinel}},  // NOLINT
-        {{575, 11390, kSentinel}},
-        {{576, 11391, kSentinel}},
-        {{577, 578, kSentinel}},
-        {{580, 649, kSentinel}},  // NOLINT
-        {{581, 652, kSentinel}},
-        {{582, 583, kSentinel}},
-        {{584, 585, kSentinel}},
-        {{586, 587, kSentinel}},  // NOLINT
-        {{588, 589, kSentinel}},
-        {{590, 591, kSentinel}},
-        {{592, 11375, kSentinel}},
-        {{593, 11373, kSentinel}},  // NOLINT
-        {{594, 11376, kSentinel}},
-        {{604, 42923, kSentinel}},
-        {{609, 42924, kSentinel}},
-        {{613, 42893, kSentinel}},  // NOLINT
-        {{614, 42922, kSentinel}},
-        {{619, 11362, kSentinel}},
-        {{620, 42925, kSentinel}},
-        {{625, 11374, kSentinel}},  // NOLINT
-        {{637, 11364, kSentinel}},
-        {{647, 42929, kSentinel}},
-        {{670, 42928, kSentinel}},
-        {{837, 921, 953, 8126}},  // NOLINT
-        {{880, 881, kSentinel}},
-        {{882, 883, kSentinel}},
-        {{886, 887, kSentinel}},
-        {{891, 1021, kSentinel}},  // NOLINT
-        {{893, 1023, kSentinel}},
-        {{895, 1011, kSentinel}},
-        {{902, 940, kSentinel}},
-        {{904, 941, kSentinel}},  // NOLINT
-        {{906, 943, kSentinel}},
-        {{908, 972, kSentinel}},
-        {{910, 973, kSentinel}},
-        {{911, 974, kSentinel}},  // NOLINT
-        {{913, 945, kSentinel}},
-        {{914, 946, 976, kSentinel}},
-        {{915, 947, kSentinel}},
-        {{916, 948, kSentinel}},  // NOLINT
-        {{917, 949, 1013, kSentinel}},
-        {{918, 950, kSentinel}},
-        {{919, 951, kSentinel}},
-        {{920, 952, 977, kSentinel}},  // NOLINT
-        {{922, 954, 1008, kSentinel}},
-        {{923, 955, kSentinel}},
-        {{925, 957, kSentinel}},
-        {{927, 959, kSentinel}},  // NOLINT
-        {{928, 960, 982, kSentinel}},
-        {{929, 961, 1009, kSentinel}},
-        {{931, 962, 963, kSentinel}},
-        {{932, 964, kSentinel}},  // NOLINT
-        {{933, 965, kSentinel}},
-        {{934, 966, 981, kSentinel}},
-        {{935, 967, kSentinel}},
-        {{939, 971, kSentinel}},  // NOLINT
-        {{975, 983, kSentinel}},
-        {{984, 985, kSentinel}},
-        {{986, 987, kSentinel}},
-        {{988, 989, kSentinel}},  // NOLINT
-        {{990, 991, kSentinel}},
-        {{992, 993, kSentinel}},
-        {{994, 995, kSentinel}},
-        {{996, 997, kSentinel}},  // NOLINT
-        {{998, 999, kSentinel}},
-        {{1000, 1001, kSentinel}},
-        {{1002, 1003, kSentinel}},
-        {{1004, 1005, kSentinel}},  // NOLINT
-        {{1006, 1007, kSentinel}},
-        {{1010, 1017, kSentinel}},
-        {{1015, 1016, kSentinel}},
-        {{1018, 1019, kSentinel}},  // NOLINT
-        {{1024, 1104, kSentinel}},
-        {{1039, 1119, kSentinel}},
-        {{1040, 1072, kSentinel}},
-        {{1071, 1103, kSentinel}},  // NOLINT
-        {{1120, 1121, kSentinel}},
-        {{1122, 1123, kSentinel}},
-        {{1124, 1125, kSentinel}},
-        {{1126, 1127, kSentinel}},  // NOLINT
-        {{1128, 1129, kSentinel}},
-        {{1130, 1131, kSentinel}},
-        {{1132, 1133, kSentinel}},
-        {{1134, 1135, kSentinel}},  // NOLINT
-        {{1136, 1137, kSentinel}},
-        {{1138, 1139, kSentinel}},
-        {{1140, 1141, kSentinel}},
-        {{1142, 1143, kSentinel}},  // NOLINT
-        {{1144, 1145, kSentinel}},
-        {{1146, 1147, kSentinel}},
-        {{1148, 1149, kSentinel}},
-        {{1150, 1151, kSentinel}},  // NOLINT
-        {{1152, 1153, kSentinel}},
-        {{1162, 1163, kSentinel}},
-        {{1164, 1165, kSentinel}},
-        {{1166, 1167, kSentinel}},  // NOLINT
-        {{1168, 1169, kSentinel}},
-        {{1170, 1171, kSentinel}},
-        {{1172, 1173, kSentinel}},
-        {{1174, 1175, kSentinel}},  // NOLINT
-        {{1176, 1177, kSentinel}},
-        {{1178, 1179, kSentinel}},
-        {{1180, 1181, kSentinel}},
-        {{1182, 1183, kSentinel}},  // NOLINT
-        {{1184, 1185, kSentinel}},
-        {{1186, 1187, kSentinel}},
-        {{1188, 1189, kSentinel}},
-        {{1190, 1191, kSentinel}},  // NOLINT
-        {{1192, 1193, kSentinel}},
-        {{1194, 1195, kSentinel}},
-        {{1196, 1197, kSentinel}},
-        {{1198, 1199, kSentinel}},  // NOLINT
-        {{1200, 1201, kSentinel}},
-        {{1202, 1203, kSentinel}},
-        {{1204, 1205, kSentinel}},
-        {{1206, 1207, kSentinel}},  // NOLINT
-        {{1208, 1209, kSentinel}},
-        {{1210, 1211, kSentinel}},
-        {{1212, 1213, kSentinel}},
-        {{1214, 1215, kSentinel}},  // NOLINT
-        {{1216, 1231, kSentinel}},
-        {{1217, 1218, kSentinel}},
-        {{1219, 1220, kSentinel}},
-        {{1221, 1222, kSentinel}},  // NOLINT
-        {{1223, 1224, kSentinel}},
-        {{1225, 1226, kSentinel}},
-        {{1227, 1228, kSentinel}},
-        {{1229, 1230, kSentinel}},  // NOLINT
-        {{1232, 1233, kSentinel}},
-        {{1234, 1235, kSentinel}},
-        {{1236, 1237, kSentinel}},
-        {{1238, 1239, kSentinel}},  // NOLINT
-        {{1240, 1241, kSentinel}},
-        {{1242, 1243, kSentinel}},
-        {{1244, 1245, kSentinel}},
-        {{1246, 1247, kSentinel}},  // NOLINT
-        {{1248, 1249, kSentinel}},
-        {{1250, 1251, kSentinel}},
-        {{1252, 1253, kSentinel}},
-        {{1254, 1255, kSentinel}},  // NOLINT
-        {{1256, 1257, kSentinel}},
-        {{1258, 1259, kSentinel}},
-        {{1260, 1261, kSentinel}},
-        {{1262, 1263, kSentinel}},  // NOLINT
-        {{1264, 1265, kSentinel}},
-        {{1266, 1267, kSentinel}},
-        {{1268, 1269, kSentinel}},
-        {{1270, 1271, kSentinel}},  // NOLINT
-        {{1272, 1273, kSentinel}},
-        {{1274, 1275, kSentinel}},
-        {{1276, 1277, kSentinel}},
-        {{1278, 1279, kSentinel}},  // NOLINT
-        {{1280, 1281, kSentinel}},
-        {{1282, 1283, kSentinel}},
-        {{1284, 1285, kSentinel}},
-        {{1286, 1287, kSentinel}},  // NOLINT
-        {{1288, 1289, kSentinel}},
-        {{1290, 1291, kSentinel}},
-        {{1292, 1293, kSentinel}},
-        {{1294, 1295, kSentinel}},  // NOLINT
-        {{1296, 1297, kSentinel}},
-        {{1298, 1299, kSentinel}},
-        {{1300, 1301, kSentinel}},
-        {{1302, 1303, kSentinel}},  // NOLINT
-        {{1304, 1305, kSentinel}},
-        {{1306, 1307, kSentinel}},
-        {{1308, 1309, kSentinel}},
-        {{1310, 1311, kSentinel}},  // NOLINT
-        {{1312, 1313, kSentinel}},
-        {{1314, 1315, kSentinel}},
-        {{1316, 1317, kSentinel}},
-        {{1318, 1319, kSentinel}},  // NOLINT
-        {{1320, 1321, kSentinel}},
-        {{1322, 1323, kSentinel}},
-        {{1324, 1325, kSentinel}},
-        {{1326, 1327, kSentinel}},  // NOLINT
-        {{1329, 1377, kSentinel}},
-        {{1366, 1414, kSentinel}},
-        {{4256, 11520, kSentinel}},
-        {{4293, 11557, kSentinel}},  // NOLINT
-        {{4295, 11559, kSentinel}},
-        {{4301, 11565, kSentinel}},
-        {{7545, 42877, kSentinel}},
-        {{7549, 11363, kSentinel}},  // NOLINT
-        {{7680, 7681, kSentinel}},
-        {{7682, 7683, kSentinel}},
-        {{7684, 7685, kSentinel}},
-        {{7686, 7687, kSentinel}},  // NOLINT
-        {{7688, 7689, kSentinel}},
-        {{7690, 7691, kSentinel}},
-        {{7692, 7693, kSentinel}},
-        {{7694, 7695, kSentinel}},  // NOLINT
-        {{7696, 7697, kSentinel}},
-        {{7698, 7699, kSentinel}},
-        {{7700, 7701, kSentinel}},
-        {{7702, 7703, kSentinel}},  // NOLINT
-        {{7704, 7705, kSentinel}},
-        {{7706, 7707, kSentinel}},
-        {{7708, 7709, kSentinel}},
-        {{7710, 7711, kSentinel}},  // NOLINT
-        {{7712, 7713, kSentinel}},
-        {{7714, 7715, kSentinel}},
-        {{7716, 7717, kSentinel}},
-        {{7718, 7719, kSentinel}},  // NOLINT
-        {{7720, 7721, kSentinel}},
-        {{7722, 7723, kSentinel}},
-        {{7724, 7725, kSentinel}},
-        {{7726, 7727, kSentinel}},  // NOLINT
-        {{7728, 7729, kSentinel}},
-        {{7730, 7731, kSentinel}},
-        {{7732, 7733, kSentinel}},
-        {{7734, 7735, kSentinel}},  // NOLINT
-        {{7736, 7737, kSentinel}},
-        {{7738, 7739, kSentinel}},
-        {{7740, 7741, kSentinel}},
-        {{7742, 7743, kSentinel}},  // NOLINT
-        {{7744, 7745, kSentinel}},
-        {{7746, 7747, kSentinel}},
-        {{7748, 7749, kSentinel}},
-        {{7750, 7751, kSentinel}},  // NOLINT
-        {{7752, 7753, kSentinel}},
-        {{7754, 7755, kSentinel}},
-        {{7756, 7757, kSentinel}},
-        {{7758, 7759, kSentinel}},  // NOLINT
-        {{7760, 7761, kSentinel}},
-        {{7762, 7763, kSentinel}},
-        {{7764, 7765, kSentinel}},
-        {{7766, 7767, kSentinel}},  // NOLINT
-        {{7768, 7769, kSentinel}},
-        {{7770, 7771, kSentinel}},
-        {{7772, 7773, kSentinel}},
-        {{7774, 7775, kSentinel}},  // NOLINT
-        {{7776, 7777, 7835, kSentinel}},
-        {{7778, 7779, kSentinel}},
-        {{7780, 7781, kSentinel}},
-        {{7782, 7783, kSentinel}},  // NOLINT
-        {{7784, 7785, kSentinel}},
-        {{7786, 7787, kSentinel}},
-        {{7788, 7789, kSentinel}},
-        {{7790, 7791, kSentinel}},  // NOLINT
-        {{7792, 7793, kSentinel}},
-        {{7794, 7795, kSentinel}},
-        {{7796, 7797, kSentinel}},
-        {{7798, 7799, kSentinel}},  // NOLINT
-        {{7800, 7801, kSentinel}},
-        {{7802, 7803, kSentinel}},
-        {{7804, 7805, kSentinel}},
-        {{7806, 7807, kSentinel}},  // NOLINT
-        {{7808, 7809, kSentinel}},
-        {{7810, 7811, kSentinel}},
-        {{7812, 7813, kSentinel}},
-        {{7814, 7815, kSentinel}},  // NOLINT
-        {{7816, 7817, kSentinel}},
-        {{7818, 7819, kSentinel}},
-        {{7820, 7821, kSentinel}},
-        {{7822, 7823, kSentinel}},  // NOLINT
-        {{7824, 7825, kSentinel}},
-        {{7826, 7827, kSentinel}},
-        {{7828, 7829, kSentinel}},
-        {{7840, 7841, kSentinel}},  // NOLINT
-        {{7842, 7843, kSentinel}},
-        {{7844, 7845, kSentinel}},
-        {{7846, 7847, kSentinel}},
-        {{7848, 7849, kSentinel}},  // NOLINT
-        {{7850, 7851, kSentinel}},
-        {{7852, 7853, kSentinel}},
-        {{7854, 7855, kSentinel}},
-        {{7856, 7857, kSentinel}},  // NOLINT
-        {{7858, 7859, kSentinel}},
-        {{7860, 7861, kSentinel}},
-        {{7862, 7863, kSentinel}},
-        {{7864, 7865, kSentinel}},  // NOLINT
-        {{7866, 7867, kSentinel}},
-        {{7868, 7869, kSentinel}},
-        {{7870, 7871, kSentinel}},
-        {{7872, 7873, kSentinel}},  // NOLINT
-        {{7874, 7875, kSentinel}},
-        {{7876, 7877, kSentinel}},
-        {{7878, 7879, kSentinel}},
-        {{7880, 7881, kSentinel}},  // NOLINT
-        {{7882, 7883, kSentinel}},
-        {{7884, 7885, kSentinel}},
-        {{7886, 7887, kSentinel}},
-        {{7888, 7889, kSentinel}},  // NOLINT
-        {{7890, 7891, kSentinel}},
-        {{7892, 7893, kSentinel}},
-        {{7894, 7895, kSentinel}},
-        {{7896, 7897, kSentinel}},  // NOLINT
-        {{7898, 7899, kSentinel}},
-        {{7900, 7901, kSentinel}},
-        {{7902, 7903, kSentinel}},
-        {{7904, 7905, kSentinel}},  // NOLINT
-        {{7906, 7907, kSentinel}},
-        {{7908, 7909, kSentinel}},
-        {{7910, 7911, kSentinel}},
-        {{7912, 7913, kSentinel}},  // NOLINT
-        {{7914, 7915, kSentinel}},
-        {{7916, 7917, kSentinel}},
-        {{7918, 7919, kSentinel}},
-        {{7920, 7921, kSentinel}},  // NOLINT
-        {{7922, 7923, kSentinel}},
-        {{7924, 7925, kSentinel}},
-        {{7926, 7927, kSentinel}},
-        {{7928, 7929, kSentinel}},  // NOLINT
-        {{7930, 7931, kSentinel}},
-        {{7932, 7933, kSentinel}},
-        {{7934, 7935, kSentinel}},
-        {{7936, 7944, kSentinel}},  // NOLINT
-        {{7943, 7951, kSentinel}},
-        {{7952, 7960, kSentinel}},
-        {{7957, 7965, kSentinel}},
-        {{7968, 7976, kSentinel}},  // NOLINT
-        {{7975, 7983, kSentinel}},
-        {{7984, 7992, kSentinel}},
-        {{7991, 7999, kSentinel}},
-        {{8000, 8008, kSentinel}},  // NOLINT
-        {{8005, 8013, kSentinel}},
-        {{8017, 8025, kSentinel}},
-        {{8019, 8027, kSentinel}},
-        {{8021, 8029, kSentinel}},  // NOLINT
-        {{8023, 8031, kSentinel}},
-        {{8032, 8040, kSentinel}},
-        {{8039, 8047, kSentinel}},
-        {{8048, 8122, kSentinel}},  // NOLINT
-        {{8049, 8123, kSentinel}},
-        {{8050, 8136, kSentinel}},
-        {{8053, 8139, kSentinel}},
-        {{8054, 8154, kSentinel}},  // NOLINT
-        {{8055, 8155, kSentinel}},
-        {{8056, 8184, kSentinel}},
-        {{8057, 8185, kSentinel}},
-        {{8058, 8170, kSentinel}},  // NOLINT
-        {{8059, 8171, kSentinel}},
-        {{8060, 8186, kSentinel}},
-        {{8061, 8187, kSentinel}},
-        {{8112, 8120, kSentinel}},  // NOLINT
-        {{8113, 8121, kSentinel}},
-        {{8144, 8152, kSentinel}},
-        {{8145, 8153, kSentinel}},
-        {{8160, 8168, kSentinel}},  // NOLINT
-        {{8161, 8169, kSentinel}},
-        {{8165, 8172, kSentinel}},
-        {{kSentinel}}};                                         // NOLINT
-static const uint16_t kEcma262UnCanonicalizeTable0Size = 1005;  // NOLINT
+    kEcma262UnCanonicalizeMultiStrings0[507] = {{{65, 97, kSentinel}},
+                                                {{90, 122, kSentinel}},
+                                                {{181, 924, 956, kSentinel}},
+                                                {{192, 224, kSentinel}},
+                                                {{214, 246, kSentinel}},
+                                                {{216, 248, kSentinel}},
+                                                {{222, 254, kSentinel}},
+                                                {{255, 376, kSentinel}},
+                                                {{256, 257, kSentinel}},
+                                                {{258, 259, kSentinel}},
+                                                {{260, 261, kSentinel}},
+                                                {{262, 263, kSentinel}},
+                                                {{264, 265, kSentinel}},
+                                                {{266, 267, kSentinel}},
+                                                {{268, 269, kSentinel}},
+                                                {{270, 271, kSentinel}},
+                                                {{272, 273, kSentinel}},
+                                                {{274, 275, kSentinel}},
+                                                {{276, 277, kSentinel}},
+                                                {{278, 279, kSentinel}},
+                                                {{280, 281, kSentinel}},
+                                                {{282, 283, kSentinel}},
+                                                {{284, 285, kSentinel}},
+                                                {{286, 287, kSentinel}},
+                                                {{288, 289, kSentinel}},
+                                                {{290, 291, kSentinel}},
+                                                {{292, 293, kSentinel}},
+                                                {{294, 295, kSentinel}},
+                                                {{296, 297, kSentinel}},
+                                                {{298, 299, kSentinel}},
+                                                {{300, 301, kSentinel}},
+                                                {{302, 303, kSentinel}},
+                                                {{306, 307, kSentinel}},
+                                                {{308, 309, kSentinel}},
+                                                {{310, 311, kSentinel}},
+                                                {{313, 314, kSentinel}},
+                                                {{315, 316, kSentinel}},
+                                                {{317, 318, kSentinel}},
+                                                {{319, 320, kSentinel}},
+                                                {{321, 322, kSentinel}},
+                                                {{323, 324, kSentinel}},
+                                                {{325, 326, kSentinel}},
+                                                {{327, 328, kSentinel}},
+                                                {{330, 331, kSentinel}},
+                                                {{332, 333, kSentinel}},
+                                                {{334, 335, kSentinel}},
+                                                {{336, 337, kSentinel}},
+                                                {{338, 339, kSentinel}},
+                                                {{340, 341, kSentinel}},
+                                                {{342, 343, kSentinel}},
+                                                {{344, 345, kSentinel}},
+                                                {{346, 347, kSentinel}},
+                                                {{348, 349, kSentinel}},
+                                                {{350, 351, kSentinel}},
+                                                {{352, 353, kSentinel}},
+                                                {{354, 355, kSentinel}},
+                                                {{356, 357, kSentinel}},
+                                                {{358, 359, kSentinel}},
+                                                {{360, 361, kSentinel}},
+                                                {{362, 363, kSentinel}},
+                                                {{364, 365, kSentinel}},
+                                                {{366, 367, kSentinel}},
+                                                {{368, 369, kSentinel}},
+                                                {{370, 371, kSentinel}},
+                                                {{372, 373, kSentinel}},
+                                                {{374, 375, kSentinel}},
+                                                {{377, 378, kSentinel}},
+                                                {{379, 380, kSentinel}},
+                                                {{381, 382, kSentinel}},
+                                                {{384, 579, kSentinel}},
+                                                {{385, 595, kSentinel}},
+                                                {{386, 387, kSentinel}},
+                                                {{388, 389, kSentinel}},
+                                                {{390, 596, kSentinel}},
+                                                {{391, 392, kSentinel}},
+                                                {{393, 598, kSentinel}},
+                                                {{394, 599, kSentinel}},
+                                                {{395, 396, kSentinel}},
+                                                {{398, 477, kSentinel}},
+                                                {{399, 601, kSentinel}},
+                                                {{400, 603, kSentinel}},
+                                                {{401, 402, kSentinel}},
+                                                {{403, 608, kSentinel}},
+                                                {{404, 611, kSentinel}},
+                                                {{405, 502, kSentinel}},
+                                                {{406, 617, kSentinel}},
+                                                {{407, 616, kSentinel}},
+                                                {{408, 409, kSentinel}},
+                                                {{410, 573, kSentinel}},
+                                                {{412, 623, kSentinel}},
+                                                {{413, 626, kSentinel}},
+                                                {{414, 544, kSentinel}},
+                                                {{415, 629, kSentinel}},
+                                                {{416, 417, kSentinel}},
+                                                {{418, 419, kSentinel}},
+                                                {{420, 421, kSentinel}},
+                                                {{422, 640, kSentinel}},
+                                                {{423, 424, kSentinel}},
+                                                {{425, 643, kSentinel}},
+                                                {{428, 429, kSentinel}},
+                                                {{430, 648, kSentinel}},
+                                                {{431, 432, kSentinel}},
+                                                {{433, 650, kSentinel}},
+                                                {{434, 651, kSentinel}},
+                                                {{435, 436, kSentinel}},
+                                                {{437, 438, kSentinel}},
+                                                {{439, 658, kSentinel}},
+                                                {{440, 441, kSentinel}},
+                                                {{444, 445, kSentinel}},
+                                                {{447, 503, kSentinel}},
+                                                {{452, 453, 454, kSentinel}},
+                                                {{455, 456, 457, kSentinel}},
+                                                {{458, 459, 460, kSentinel}},
+                                                {{461, 462, kSentinel}},
+                                                {{463, 464, kSentinel}},
+                                                {{465, 466, kSentinel}},
+                                                {{467, 468, kSentinel}},
+                                                {{469, 470, kSentinel}},
+                                                {{471, 472, kSentinel}},
+                                                {{473, 474, kSentinel}},
+                                                {{475, 476, kSentinel}},
+                                                {{478, 479, kSentinel}},
+                                                {{480, 481, kSentinel}},
+                                                {{482, 483, kSentinel}},
+                                                {{484, 485, kSentinel}},
+                                                {{486, 487, kSentinel}},
+                                                {{488, 489, kSentinel}},
+                                                {{490, 491, kSentinel}},
+                                                {{492, 493, kSentinel}},
+                                                {{494, 495, kSentinel}},
+                                                {{497, 498, 499, kSentinel}},
+                                                {{500, 501, kSentinel}},
+                                                {{504, 505, kSentinel}},
+                                                {{506, 507, kSentinel}},
+                                                {{508, 509, kSentinel}},
+                                                {{510, 511, kSentinel}},
+                                                {{512, 513, kSentinel}},
+                                                {{514, 515, kSentinel}},
+                                                {{516, 517, kSentinel}},
+                                                {{518, 519, kSentinel}},
+                                                {{520, 521, kSentinel}},
+                                                {{522, 523, kSentinel}},
+                                                {{524, 525, kSentinel}},
+                                                {{526, 527, kSentinel}},
+                                                {{528, 529, kSentinel}},
+                                                {{530, 531, kSentinel}},
+                                                {{532, 533, kSentinel}},
+                                                {{534, 535, kSentinel}},
+                                                {{536, 537, kSentinel}},
+                                                {{538, 539, kSentinel}},
+                                                {{540, 541, kSentinel}},
+                                                {{542, 543, kSentinel}},
+                                                {{546, 547, kSentinel}},
+                                                {{548, 549, kSentinel}},
+                                                {{550, 551, kSentinel}},
+                                                {{552, 553, kSentinel}},
+                                                {{554, 555, kSentinel}},
+                                                {{556, 557, kSentinel}},
+                                                {{558, 559, kSentinel}},
+                                                {{560, 561, kSentinel}},
+                                                {{562, 563, kSentinel}},
+                                                {{570, 11365, kSentinel}},
+                                                {{571, 572, kSentinel}},
+                                                {{574, 11366, kSentinel}},
+                                                {{575, 11390, kSentinel}},
+                                                {{576, 11391, kSentinel}},
+                                                {{577, 578, kSentinel}},
+                                                {{580, 649, kSentinel}},
+                                                {{581, 652, kSentinel}},
+                                                {{582, 583, kSentinel}},
+                                                {{584, 585, kSentinel}},
+                                                {{586, 587, kSentinel}},
+                                                {{588, 589, kSentinel}},
+                                                {{590, 591, kSentinel}},
+                                                {{592, 11375, kSentinel}},
+                                                {{593, 11373, kSentinel}},
+                                                {{594, 11376, kSentinel}},
+                                                {{604, 42923, kSentinel}},
+                                                {{609, 42924, kSentinel}},
+                                                {{613, 42893, kSentinel}},
+                                                {{614, 42922, kSentinel}},
+                                                {{619, 11362, kSentinel}},
+                                                {{620, 42925, kSentinel}},
+                                                {{625, 11374, kSentinel}},
+                                                {{637, 11364, kSentinel}},
+                                                {{647, 42929, kSentinel}},
+                                                {{670, 42928, kSentinel}},
+                                                {{837, 921, 953, 8126}},
+                                                {{880, 881, kSentinel}},
+                                                {{882, 883, kSentinel}},
+                                                {{886, 887, kSentinel}},
+                                                {{891, 1021, kSentinel}},
+                                                {{893, 1023, kSentinel}},
+                                                {{895, 1011, kSentinel}},
+                                                {{902, 940, kSentinel}},
+                                                {{904, 941, kSentinel}},
+                                                {{906, 943, kSentinel}},
+                                                {{908, 972, kSentinel}},
+                                                {{910, 973, kSentinel}},
+                                                {{911, 974, kSentinel}},
+                                                {{913, 945, kSentinel}},
+                                                {{914, 946, 976, kSentinel}},
+                                                {{915, 947, kSentinel}},
+                                                {{916, 948, kSentinel}},
+                                                {{917, 949, 1013, kSentinel}},
+                                                {{918, 950, kSentinel}},
+                                                {{919, 951, kSentinel}},
+                                                {{920, 952, 977, kSentinel}},
+                                                {{922, 954, 1008, kSentinel}},
+                                                {{923, 955, kSentinel}},
+                                                {{925, 957, kSentinel}},
+                                                {{927, 959, kSentinel}},
+                                                {{928, 960, 982, kSentinel}},
+                                                {{929, 961, 1009, kSentinel}},
+                                                {{931, 962, 963, kSentinel}},
+                                                {{932, 964, kSentinel}},
+                                                {{933, 965, kSentinel}},
+                                                {{934, 966, 981, kSentinel}},
+                                                {{935, 967, kSentinel}},
+                                                {{939, 971, kSentinel}},
+                                                {{975, 983, kSentinel}},
+                                                {{984, 985, kSentinel}},
+                                                {{986, 987, kSentinel}},
+                                                {{988, 989, kSentinel}},
+                                                {{990, 991, kSentinel}},
+                                                {{992, 993, kSentinel}},
+                                                {{994, 995, kSentinel}},
+                                                {{996, 997, kSentinel}},
+                                                {{998, 999, kSentinel}},
+                                                {{1000, 1001, kSentinel}},
+                                                {{1002, 1003, kSentinel}},
+                                                {{1004, 1005, kSentinel}},
+                                                {{1006, 1007, kSentinel}},
+                                                {{1010, 1017, kSentinel}},
+                                                {{1015, 1016, kSentinel}},
+                                                {{1018, 1019, kSentinel}},
+                                                {{1024, 1104, kSentinel}},
+                                                {{1039, 1119, kSentinel}},
+                                                {{1040, 1072, kSentinel}},
+                                                {{1071, 1103, kSentinel}},
+                                                {{1120, 1121, kSentinel}},
+                                                {{1122, 1123, kSentinel}},
+                                                {{1124, 1125, kSentinel}},
+                                                {{1126, 1127, kSentinel}},
+                                                {{1128, 1129, kSentinel}},
+                                                {{1130, 1131, kSentinel}},
+                                                {{1132, 1133, kSentinel}},
+                                                {{1134, 1135, kSentinel}},
+                                                {{1136, 1137, kSentinel}},
+                                                {{1138, 1139, kSentinel}},
+                                                {{1140, 1141, kSentinel}},
+                                                {{1142, 1143, kSentinel}},
+                                                {{1144, 1145, kSentinel}},
+                                                {{1146, 1147, kSentinel}},
+                                                {{1148, 1149, kSentinel}},
+                                                {{1150, 1151, kSentinel}},
+                                                {{1152, 1153, kSentinel}},
+                                                {{1162, 1163, kSentinel}},
+                                                {{1164, 1165, kSentinel}},
+                                                {{1166, 1167, kSentinel}},
+                                                {{1168, 1169, kSentinel}},
+                                                {{1170, 1171, kSentinel}},
+                                                {{1172, 1173, kSentinel}},
+                                                {{1174, 1175, kSentinel}},
+                                                {{1176, 1177, kSentinel}},
+                                                {{1178, 1179, kSentinel}},
+                                                {{1180, 1181, kSentinel}},
+                                                {{1182, 1183, kSentinel}},
+                                                {{1184, 1185, kSentinel}},
+                                                {{1186, 1187, kSentinel}},
+                                                {{1188, 1189, kSentinel}},
+                                                {{1190, 1191, kSentinel}},
+                                                {{1192, 1193, kSentinel}},
+                                                {{1194, 1195, kSentinel}},
+                                                {{1196, 1197, kSentinel}},
+                                                {{1198, 1199, kSentinel}},
+                                                {{1200, 1201, kSentinel}},
+                                                {{1202, 1203, kSentinel}},
+                                                {{1204, 1205, kSentinel}},
+                                                {{1206, 1207, kSentinel}},
+                                                {{1208, 1209, kSentinel}},
+                                                {{1210, 1211, kSentinel}},
+                                                {{1212, 1213, kSentinel}},
+                                                {{1214, 1215, kSentinel}},
+                                                {{1216, 1231, kSentinel}},
+                                                {{1217, 1218, kSentinel}},
+                                                {{1219, 1220, kSentinel}},
+                                                {{1221, 1222, kSentinel}},
+                                                {{1223, 1224, kSentinel}},
+                                                {{1225, 1226, kSentinel}},
+                                                {{1227, 1228, kSentinel}},
+                                                {{1229, 1230, kSentinel}},
+                                                {{1232, 1233, kSentinel}},
+                                                {{1234, 1235, kSentinel}},
+                                                {{1236, 1237, kSentinel}},
+                                                {{1238, 1239, kSentinel}},
+                                                {{1240, 1241, kSentinel}},
+                                                {{1242, 1243, kSentinel}},
+                                                {{1244, 1245, kSentinel}},
+                                                {{1246, 1247, kSentinel}},
+                                                {{1248, 1249, kSentinel}},
+                                                {{1250, 1251, kSentinel}},
+                                                {{1252, 1253, kSentinel}},
+                                                {{1254, 1255, kSentinel}},
+                                                {{1256, 1257, kSentinel}},
+                                                {{1258, 1259, kSentinel}},
+                                                {{1260, 1261, kSentinel}},
+                                                {{1262, 1263, kSentinel}},
+                                                {{1264, 1265, kSentinel}},
+                                                {{1266, 1267, kSentinel}},
+                                                {{1268, 1269, kSentinel}},
+                                                {{1270, 1271, kSentinel}},
+                                                {{1272, 1273, kSentinel}},
+                                                {{1274, 1275, kSentinel}},
+                                                {{1276, 1277, kSentinel}},
+                                                {{1278, 1279, kSentinel}},
+                                                {{1280, 1281, kSentinel}},
+                                                {{1282, 1283, kSentinel}},
+                                                {{1284, 1285, kSentinel}},
+                                                {{1286, 1287, kSentinel}},
+                                                {{1288, 1289, kSentinel}},
+                                                {{1290, 1291, kSentinel}},
+                                                {{1292, 1293, kSentinel}},
+                                                {{1294, 1295, kSentinel}},
+                                                {{1296, 1297, kSentinel}},
+                                                {{1298, 1299, kSentinel}},
+                                                {{1300, 1301, kSentinel}},
+                                                {{1302, 1303, kSentinel}},
+                                                {{1304, 1305, kSentinel}},
+                                                {{1306, 1307, kSentinel}},
+                                                {{1308, 1309, kSentinel}},
+                                                {{1310, 1311, kSentinel}},
+                                                {{1312, 1313, kSentinel}},
+                                                {{1314, 1315, kSentinel}},
+                                                {{1316, 1317, kSentinel}},
+                                                {{1318, 1319, kSentinel}},
+                                                {{1320, 1321, kSentinel}},
+                                                {{1322, 1323, kSentinel}},
+                                                {{1324, 1325, kSentinel}},
+                                                {{1326, 1327, kSentinel}},
+                                                {{1329, 1377, kSentinel}},
+                                                {{1366, 1414, kSentinel}},
+                                                {{4256, 11520, kSentinel}},
+                                                {{4293, 11557, kSentinel}},
+                                                {{4295, 11559, kSentinel}},
+                                                {{4301, 11565, kSentinel}},
+                                                {{7545, 42877, kSentinel}},
+                                                {{7549, 11363, kSentinel}},
+                                                {{7680, 7681, kSentinel}},
+                                                {{7682, 7683, kSentinel}},
+                                                {{7684, 7685, kSentinel}},
+                                                {{7686, 7687, kSentinel}},
+                                                {{7688, 7689, kSentinel}},
+                                                {{7690, 7691, kSentinel}},
+                                                {{7692, 7693, kSentinel}},
+                                                {{7694, 7695, kSentinel}},
+                                                {{7696, 7697, kSentinel}},
+                                                {{7698, 7699, kSentinel}},
+                                                {{7700, 7701, kSentinel}},
+                                                {{7702, 7703, kSentinel}},
+                                                {{7704, 7705, kSentinel}},
+                                                {{7706, 7707, kSentinel}},
+                                                {{7708, 7709, kSentinel}},
+                                                {{7710, 7711, kSentinel}},
+                                                {{7712, 7713, kSentinel}},
+                                                {{7714, 7715, kSentinel}},
+                                                {{7716, 7717, kSentinel}},
+                                                {{7718, 7719, kSentinel}},
+                                                {{7720, 7721, kSentinel}},
+                                                {{7722, 7723, kSentinel}},
+                                                {{7724, 7725, kSentinel}},
+                                                {{7726, 7727, kSentinel}},
+                                                {{7728, 7729, kSentinel}},
+                                                {{7730, 7731, kSentinel}},
+                                                {{7732, 7733, kSentinel}},
+                                                {{7734, 7735, kSentinel}},
+                                                {{7736, 7737, kSentinel}},
+                                                {{7738, 7739, kSentinel}},
+                                                {{7740, 7741, kSentinel}},
+                                                {{7742, 7743, kSentinel}},
+                                                {{7744, 7745, kSentinel}},
+                                                {{7746, 7747, kSentinel}},
+                                                {{7748, 7749, kSentinel}},
+                                                {{7750, 7751, kSentinel}},
+                                                {{7752, 7753, kSentinel}},
+                                                {{7754, 7755, kSentinel}},
+                                                {{7756, 7757, kSentinel}},
+                                                {{7758, 7759, kSentinel}},
+                                                {{7760, 7761, kSentinel}},
+                                                {{7762, 7763, kSentinel}},
+                                                {{7764, 7765, kSentinel}},
+                                                {{7766, 7767, kSentinel}},
+                                                {{7768, 7769, kSentinel}},
+                                                {{7770, 7771, kSentinel}},
+                                                {{7772, 7773, kSentinel}},
+                                                {{7774, 7775, kSentinel}},
+                                                {{7776, 7777, 7835, kSentinel}},
+                                                {{7778, 7779, kSentinel}},
+                                                {{7780, 7781, kSentinel}},
+                                                {{7782, 7783, kSentinel}},
+                                                {{7784, 7785, kSentinel}},
+                                                {{7786, 7787, kSentinel}},
+                                                {{7788, 7789, kSentinel}},
+                                                {{7790, 7791, kSentinel}},
+                                                {{7792, 7793, kSentinel}},
+                                                {{7794, 7795, kSentinel}},
+                                                {{7796, 7797, kSentinel}},
+                                                {{7798, 7799, kSentinel}},
+                                                {{7800, 7801, kSentinel}},
+                                                {{7802, 7803, kSentinel}},
+                                                {{7804, 7805, kSentinel}},
+                                                {{7806, 7807, kSentinel}},
+                                                {{7808, 7809, kSentinel}},
+                                                {{7810, 7811, kSentinel}},
+                                                {{7812, 7813, kSentinel}},
+                                                {{7814, 7815, kSentinel}},
+                                                {{7816, 7817, kSentinel}},
+                                                {{7818, 7819, kSentinel}},
+                                                {{7820, 7821, kSentinel}},
+                                                {{7822, 7823, kSentinel}},
+                                                {{7824, 7825, kSentinel}},
+                                                {{7826, 7827, kSentinel}},
+                                                {{7828, 7829, kSentinel}},
+                                                {{7840, 7841, kSentinel}},
+                                                {{7842, 7843, kSentinel}},
+                                                {{7844, 7845, kSentinel}},
+                                                {{7846, 7847, kSentinel}},
+                                                {{7848, 7849, kSentinel}},
+                                                {{7850, 7851, kSentinel}},
+                                                {{7852, 7853, kSentinel}},
+                                                {{7854, 7855, kSentinel}},
+                                                {{7856, 7857, kSentinel}},
+                                                {{7858, 7859, kSentinel}},
+                                                {{7860, 7861, kSentinel}},
+                                                {{7862, 7863, kSentinel}},
+                                                {{7864, 7865, kSentinel}},
+                                                {{7866, 7867, kSentinel}},
+                                                {{7868, 7869, kSentinel}},
+                                                {{7870, 7871, kSentinel}},
+                                                {{7872, 7873, kSentinel}},
+                                                {{7874, 7875, kSentinel}},
+                                                {{7876, 7877, kSentinel}},
+                                                {{7878, 7879, kSentinel}},
+                                                {{7880, 7881, kSentinel}},
+                                                {{7882, 7883, kSentinel}},
+                                                {{7884, 7885, kSentinel}},
+                                                {{7886, 7887, kSentinel}},
+                                                {{7888, 7889, kSentinel}},
+                                                {{7890, 7891, kSentinel}},
+                                                {{7892, 7893, kSentinel}},
+                                                {{7894, 7895, kSentinel}},
+                                                {{7896, 7897, kSentinel}},
+                                                {{7898, 7899, kSentinel}},
+                                                {{7900, 7901, kSentinel}},
+                                                {{7902, 7903, kSentinel}},
+                                                {{7904, 7905, kSentinel}},
+                                                {{7906, 7907, kSentinel}},
+                                                {{7908, 7909, kSentinel}},
+                                                {{7910, 7911, kSentinel}},
+                                                {{7912, 7913, kSentinel}},
+                                                {{7914, 7915, kSentinel}},
+                                                {{7916, 7917, kSentinel}},
+                                                {{7918, 7919, kSentinel}},
+                                                {{7920, 7921, kSentinel}},
+                                                {{7922, 7923, kSentinel}},
+                                                {{7924, 7925, kSentinel}},
+                                                {{7926, 7927, kSentinel}},
+                                                {{7928, 7929, kSentinel}},
+                                                {{7930, 7931, kSentinel}},
+                                                {{7932, 7933, kSentinel}},
+                                                {{7934, 7935, kSentinel}},
+                                                {{7936, 7944, kSentinel}},
+                                                {{7943, 7951, kSentinel}},
+                                                {{7952, 7960, kSentinel}},
+                                                {{7957, 7965, kSentinel}},
+                                                {{7968, 7976, kSentinel}},
+                                                {{7975, 7983, kSentinel}},
+                                                {{7984, 7992, kSentinel}},
+                                                {{7991, 7999, kSentinel}},
+                                                {{8000, 8008, kSentinel}},
+                                                {{8005, 8013, kSentinel}},
+                                                {{8017, 8025, kSentinel}},
+                                                {{8019, 8027, kSentinel}},
+                                                {{8021, 8029, kSentinel}},
+                                                {{8023, 8031, kSentinel}},
+                                                {{8032, 8040, kSentinel}},
+                                                {{8039, 8047, kSentinel}},
+                                                {{8048, 8122, kSentinel}},
+                                                {{8049, 8123, kSentinel}},
+                                                {{8050, 8136, kSentinel}},
+                                                {{8053, 8139, kSentinel}},
+                                                {{8054, 8154, kSentinel}},
+                                                {{8055, 8155, kSentinel}},
+                                                {{8056, 8184, kSentinel}},
+                                                {{8057, 8185, kSentinel}},
+                                                {{8058, 8170, kSentinel}},
+                                                {{8059, 8171, kSentinel}},
+                                                {{8060, 8186, kSentinel}},
+                                                {{8061, 8187, kSentinel}},
+                                                {{8112, 8120, kSentinel}},
+                                                {{8113, 8121, kSentinel}},
+                                                {{8144, 8152, kSentinel}},
+                                                {{8145, 8153, kSentinel}},
+                                                {{8160, 8168, kSentinel}},
+                                                {{8161, 8169, kSentinel}},
+                                                {{8165, 8172, kSentinel}},
+                                                {{kSentinel}}};
+static const uint16_t kEcma262UnCanonicalizeTable0Size = 1005;
 static const int32_t kEcma262UnCanonicalizeTable0[2010] = {
-    1073741889, 1,    90,         5,    1073741921, 1,
-    122,        5,    181,        9,    1073742016, 13,
-    214,        17,   1073742040, 21,  // NOLINT
-    222,        25,   1073742048, 13,   246,        17,
-    1073742072, 21,   254,        25,   255,        29,
-    256,        33,   257,        33,  // NOLINT
-    258,        37,   259,        37,   260,        41,
-    261,        41,   262,        45,   263,        45,
-    264,        49,   265,        49,  // NOLINT
-    266,        53,   267,        53,   268,        57,
-    269,        57,   270,        61,   271,        61,
-    272,        65,   273,        65,  // NOLINT
-    274,        69,   275,        69,   276,        73,
-    277,        73,   278,        77,   279,        77,
-    280,        81,   281,        81,  // NOLINT
-    282,        85,   283,        85,   284,        89,
-    285,        89,   286,        93,   287,        93,
-    288,        97,   289,        97,  // NOLINT
-    290,        101,  291,        101,  292,        105,
-    293,        105,  294,        109,  295,        109,
-    296,        113,  297,        113,  // NOLINT
-    298,        117,  299,        117,  300,        121,
-    301,        121,  302,        125,  303,        125,
-    306,        129,  307,        129,  // NOLINT
-    308,        133,  309,        133,  310,        137,
-    311,        137,  313,        141,  314,        141,
-    315,        145,  316,        145,  // NOLINT
-    317,        149,  318,        149,  319,        153,
-    320,        153,  321,        157,  322,        157,
-    323,        161,  324,        161,  // NOLINT
-    325,        165,  326,        165,  327,        169,
-    328,        169,  330,        173,  331,        173,
-    332,        177,  333,        177,  // NOLINT
-    334,        181,  335,        181,  336,        185,
-    337,        185,  338,        189,  339,        189,
-    340,        193,  341,        193,  // NOLINT
-    342,        197,  343,        197,  344,        201,
-    345,        201,  346,        205,  347,        205,
-    348,        209,  349,        209,  // NOLINT
-    350,        213,  351,        213,  352,        217,
-    353,        217,  354,        221,  355,        221,
-    356,        225,  357,        225,  // NOLINT
-    358,        229,  359,        229,  360,        233,
-    361,        233,  362,        237,  363,        237,
-    364,        241,  365,        241,  // NOLINT
-    366,        245,  367,        245,  368,        249,
-    369,        249,  370,        253,  371,        253,
-    372,        257,  373,        257,  // NOLINT
-    374,        261,  375,        261,  376,        29,
-    377,        265,  378,        265,  379,        269,
-    380,        269,  381,        273,  // NOLINT
-    382,        273,  384,        277,  385,        281,
-    386,        285,  387,        285,  388,        289,
-    389,        289,  390,        293,  // NOLINT
-    391,        297,  392,        297,  1073742217, 301,
-    394,        305,  395,        309,  396,        309,
-    398,        313,  399,        317,  // NOLINT
-    400,        321,  401,        325,  402,        325,
-    403,        329,  404,        333,  405,        337,
-    406,        341,  407,        345,  // NOLINT
-    408,        349,  409,        349,  410,        353,
-    412,        357,  413,        361,  414,        365,
-    415,        369,  416,        373,  // NOLINT
-    417,        373,  418,        377,  419,        377,
-    420,        381,  421,        381,  422,        385,
-    423,        389,  424,        389,  // NOLINT
-    425,        393,  428,        397,  429,        397,
-    430,        401,  431,        405,  432,        405,
-    1073742257, 409,  434,        413,  // NOLINT
-    435,        417,  436,        417,  437,        421,
-    438,        421,  439,        425,  440,        429,
-    441,        429,  444,        433,  // NOLINT
-    445,        433,  447,        437,  452,        441,
-    453,        441,  454,        441,  455,        445,
-    456,        445,  457,        445,  // NOLINT
-    458,        449,  459,        449,  460,        449,
-    461,        453,  462,        453,  463,        457,
-    464,        457,  465,        461,  // NOLINT
-    466,        461,  467,        465,  468,        465,
-    469,        469,  470,        469,  471,        473,
-    472,        473,  473,        477,  // NOLINT
-    474,        477,  475,        481,  476,        481,
-    477,        313,  478,        485,  479,        485,
-    480,        489,  481,        489,  // NOLINT
-    482,        493,  483,        493,  484,        497,
-    485,        497,  486,        501,  487,        501,
-    488,        505,  489,        505,  // NOLINT
-    490,        509,  491,        509,  492,        513,
-    493,        513,  494,        517,  495,        517,
-    497,        521,  498,        521,  // NOLINT
-    499,        521,  500,        525,  501,        525,
-    502,        337,  503,        437,  504,        529,
-    505,        529,  506,        533,  // NOLINT
-    507,        533,  508,        537,  509,        537,
-    510,        541,  511,        541,  512,        545,
-    513,        545,  514,        549,  // NOLINT
-    515,        549,  516,        553,  517,        553,
-    518,        557,  519,        557,  520,        561,
-    521,        561,  522,        565,  // NOLINT
-    523,        565,  524,        569,  525,        569,
-    526,        573,  527,        573,  528,        577,
-    529,        577,  530,        581,  // NOLINT
-    531,        581,  532,        585,  533,        585,
-    534,        589,  535,        589,  536,        593,
-    537,        593,  538,        597,  // NOLINT
-    539,        597,  540,        601,  541,        601,
-    542,        605,  543,        605,  544,        365,
-    546,        609,  547,        609,  // NOLINT
-    548,        613,  549,        613,  550,        617,
-    551,        617,  552,        621,  553,        621,
-    554,        625,  555,        625,  // NOLINT
-    556,        629,  557,        629,  558,        633,
-    559,        633,  560,        637,  561,        637,
-    562,        641,  563,        641,  // NOLINT
-    570,        645,  571,        649,  572,        649,
-    573,        353,  574,        653,  1073742399, 657,
-    576,        661,  577,        665,  // NOLINT
-    578,        665,  579,        277,  580,        669,
-    581,        673,  582,        677,  583,        677,
-    584,        681,  585,        681,  // NOLINT
-    586,        685,  587,        685,  588,        689,
-    589,        689,  590,        693,  591,        693,
-    592,        697,  593,        701,  // NOLINT
-    594,        705,  595,        281,  596,        293,
-    1073742422, 301,  599,        305,  601,        317,
-    603,        321,  604,        709,  // NOLINT
-    608,        329,  609,        713,  611,        333,
-    613,        717,  614,        721,  616,        345,
-    617,        341,  619,        725,  // NOLINT
-    620,        729,  623,        357,  625,        733,
-    626,        361,  629,        369,  637,        737,
-    640,        385,  643,        393,  // NOLINT
-    647,        741,  648,        401,  649,        669,
-    1073742474, 409,  651,        413,  652,        673,
-    658,        425,  670,        745,  // NOLINT
-    837,        749,  880,        753,  881,        753,
-    882,        757,  883,        757,  886,        761,
-    887,        761,  1073742715, 765,  // NOLINT
-    893,        769,  895,        773,  902,        777,
-    1073742728, 781,  906,        785,  908,        789,
-    1073742734, 793,  911,        797,  // NOLINT
-    913,        801,  914,        805,  1073742739, 809,
-    916,        813,  917,        817,  1073742742, 821,
-    919,        825,  920,        829,  // NOLINT
-    921,        749,  922,        833,  923,        837,
-    924,        9,    1073742749, 841,  927,        845,
-    928,        849,  929,        853,  // NOLINT
-    931,        857,  1073742756, 861,  933,        865,
-    934,        869,  1073742759, 873,  939,        877,
-    940,        777,  1073742765, 781,  // NOLINT
-    943,        785,  945,        801,  946,        805,
-    1073742771, 809,  948,        813,  949,        817,
-    1073742774, 821,  951,        825,  // NOLINT
-    952,        829,  953,        749,  954,        833,
-    955,        837,  956,        9,    1073742781, 841,
-    959,        845,  960,        849,  // NOLINT
-    961,        853,  962,        857,  963,        857,
-    1073742788, 861,  965,        865,  966,        869,
-    1073742791, 873,  971,        877,  // NOLINT
-    972,        789,  1073742797, 793,  974,        797,
-    975,        881,  976,        805,  977,        829,
-    981,        869,  982,        849,  // NOLINT
-    983,        881,  984,        885,  985,        885,
-    986,        889,  987,        889,  988,        893,
-    989,        893,  990,        897,  // NOLINT
-    991,        897,  992,        901,  993,        901,
-    994,        905,  995,        905,  996,        909,
-    997,        909,  998,        913,  // NOLINT
-    999,        913,  1000,       917,  1001,       917,
-    1002,       921,  1003,       921,  1004,       925,
-    1005,       925,  1006,       929,  // NOLINT
-    1007,       929,  1008,       833,  1009,       853,
-    1010,       933,  1011,       773,  1013,       817,
-    1015,       937,  1016,       937,  // NOLINT
-    1017,       933,  1018,       941,  1019,       941,
-    1073742845, 765,  1023,       769,  1073742848, 945,
-    1039,       949,  1073742864, 953,  // NOLINT
-    1071,       957,  1073742896, 953,  1103,       957,
-    1073742928, 945,  1119,       949,  1120,       961,
-    1121,       961,  1122,       965,  // NOLINT
-    1123,       965,  1124,       969,  1125,       969,
-    1126,       973,  1127,       973,  1128,       977,
-    1129,       977,  1130,       981,  // NOLINT
-    1131,       981,  1132,       985,  1133,       985,
-    1134,       989,  1135,       989,  1136,       993,
-    1137,       993,  1138,       997,  // NOLINT
-    1139,       997,  1140,       1001, 1141,       1001,
-    1142,       1005, 1143,       1005, 1144,       1009,
-    1145,       1009, 1146,       1013,  // NOLINT
-    1147,       1013, 1148,       1017, 1149,       1017,
-    1150,       1021, 1151,       1021, 1152,       1025,
-    1153,       1025, 1162,       1029,  // NOLINT
-    1163,       1029, 1164,       1033, 1165,       1033,
-    1166,       1037, 1167,       1037, 1168,       1041,
-    1169,       1041, 1170,       1045,  // NOLINT
-    1171,       1045, 1172,       1049, 1173,       1049,
-    1174,       1053, 1175,       1053, 1176,       1057,
-    1177,       1057, 1178,       1061,  // NOLINT
-    1179,       1061, 1180,       1065, 1181,       1065,
-    1182,       1069, 1183,       1069, 1184,       1073,
-    1185,       1073, 1186,       1077,  // NOLINT
-    1187,       1077, 1188,       1081, 1189,       1081,
-    1190,       1085, 1191,       1085, 1192,       1089,
-    1193,       1089, 1194,       1093,  // NOLINT
-    1195,       1093, 1196,       1097, 1197,       1097,
-    1198,       1101, 1199,       1101, 1200,       1105,
-    1201,       1105, 1202,       1109,  // NOLINT
-    1203,       1109, 1204,       1113, 1205,       1113,
-    1206,       1117, 1207,       1117, 1208,       1121,
-    1209,       1121, 1210,       1125,  // NOLINT
-    1211,       1125, 1212,       1129, 1213,       1129,
-    1214,       1133, 1215,       1133, 1216,       1137,
-    1217,       1141, 1218,       1141,  // NOLINT
-    1219,       1145, 1220,       1145, 1221,       1149,
-    1222,       1149, 1223,       1153, 1224,       1153,
-    1225,       1157, 1226,       1157,  // NOLINT
-    1227,       1161, 1228,       1161, 1229,       1165,
-    1230,       1165, 1231,       1137, 1232,       1169,
-    1233,       1169, 1234,       1173,  // NOLINT
-    1235,       1173, 1236,       1177, 1237,       1177,
-    1238,       1181, 1239,       1181, 1240,       1185,
-    1241,       1185, 1242,       1189,  // NOLINT
-    1243,       1189, 1244,       1193, 1245,       1193,
-    1246,       1197, 1247,       1197, 1248,       1201,
-    1249,       1201, 1250,       1205,  // NOLINT
-    1251,       1205, 1252,       1209, 1253,       1209,
-    1254,       1213, 1255,       1213, 1256,       1217,
-    1257,       1217, 1258,       1221,  // NOLINT
-    1259,       1221, 1260,       1225, 1261,       1225,
-    1262,       1229, 1263,       1229, 1264,       1233,
-    1265,       1233, 1266,       1237,  // NOLINT
-    1267,       1237, 1268,       1241, 1269,       1241,
-    1270,       1245, 1271,       1245, 1272,       1249,
-    1273,       1249, 1274,       1253,  // NOLINT
-    1275,       1253, 1276,       1257, 1277,       1257,
-    1278,       1261, 1279,       1261, 1280,       1265,
-    1281,       1265, 1282,       1269,  // NOLINT
-    1283,       1269, 1284,       1273, 1285,       1273,
-    1286,       1277, 1287,       1277, 1288,       1281,
-    1289,       1281, 1290,       1285,  // NOLINT
-    1291,       1285, 1292,       1289, 1293,       1289,
-    1294,       1293, 1295,       1293, 1296,       1297,
-    1297,       1297, 1298,       1301,  // NOLINT
-    1299,       1301, 1300,       1305, 1301,       1305,
-    1302,       1309, 1303,       1309, 1304,       1313,
-    1305,       1313, 1306,       1317,  // NOLINT
-    1307,       1317, 1308,       1321, 1309,       1321,
-    1310,       1325, 1311,       1325, 1312,       1329,
-    1313,       1329, 1314,       1333,  // NOLINT
-    1315,       1333, 1316,       1337, 1317,       1337,
-    1318,       1341, 1319,       1341, 1320,       1345,
-    1321,       1345, 1322,       1349,  // NOLINT
-    1323,       1349, 1324,       1353, 1325,       1353,
-    1326,       1357, 1327,       1357, 1073743153, 1361,
-    1366,       1365, 1073743201, 1361,  // NOLINT
-    1414,       1365, 1073746080, 1369, 4293,       1373,
-    4295,       1377, 4301,       1381, 7545,       1385,
-    7549,       1389, 7680,       1393,  // NOLINT
-    7681,       1393, 7682,       1397, 7683,       1397,
-    7684,       1401, 7685,       1401, 7686,       1405,
-    7687,       1405, 7688,       1409,  // NOLINT
-    7689,       1409, 7690,       1413, 7691,       1413,
-    7692,       1417, 7693,       1417, 7694,       1421,
-    7695,       1421, 7696,       1425,  // NOLINT
-    7697,       1425, 7698,       1429, 7699,       1429,
-    7700,       1433, 7701,       1433, 7702,       1437,
-    7703,       1437, 7704,       1441,  // NOLINT
-    7705,       1441, 7706,       1445, 7707,       1445,
-    7708,       1449, 7709,       1449, 7710,       1453,
-    7711,       1453, 7712,       1457,  // NOLINT
-    7713,       1457, 7714,       1461, 7715,       1461,
-    7716,       1465, 7717,       1465, 7718,       1469,
-    7719,       1469, 7720,       1473,  // NOLINT
-    7721,       1473, 7722,       1477, 7723,       1477,
-    7724,       1481, 7725,       1481, 7726,       1485,
-    7727,       1485, 7728,       1489,  // NOLINT
-    7729,       1489, 7730,       1493, 7731,       1493,
-    7732,       1497, 7733,       1497, 7734,       1501,
-    7735,       1501, 7736,       1505,  // NOLINT
-    7737,       1505, 7738,       1509, 7739,       1509,
-    7740,       1513, 7741,       1513, 7742,       1517,
-    7743,       1517, 7744,       1521,  // NOLINT
-    7745,       1521, 7746,       1525, 7747,       1525,
-    7748,       1529, 7749,       1529, 7750,       1533,
-    7751,       1533, 7752,       1537,  // NOLINT
-    7753,       1537, 7754,       1541, 7755,       1541,
-    7756,       1545, 7757,       1545, 7758,       1549,
-    7759,       1549, 7760,       1553,  // NOLINT
-    7761,       1553, 7762,       1557, 7763,       1557,
-    7764,       1561, 7765,       1561, 7766,       1565,
-    7767,       1565, 7768,       1569,  // NOLINT
-    7769,       1569, 7770,       1573, 7771,       1573,
-    7772,       1577, 7773,       1577, 7774,       1581,
-    7775,       1581, 7776,       1585,  // NOLINT
-    7777,       1585, 7778,       1589, 7779,       1589,
-    7780,       1593, 7781,       1593, 7782,       1597,
-    7783,       1597, 7784,       1601,  // NOLINT
-    7785,       1601, 7786,       1605, 7787,       1605,
-    7788,       1609, 7789,       1609, 7790,       1613,
-    7791,       1613, 7792,       1617,  // NOLINT
-    7793,       1617, 7794,       1621, 7795,       1621,
-    7796,       1625, 7797,       1625, 7798,       1629,
-    7799,       1629, 7800,       1633,  // NOLINT
-    7801,       1633, 7802,       1637, 7803,       1637,
-    7804,       1641, 7805,       1641, 7806,       1645,
-    7807,       1645, 7808,       1649,  // NOLINT
-    7809,       1649, 7810,       1653, 7811,       1653,
-    7812,       1657, 7813,       1657, 7814,       1661,
-    7815,       1661, 7816,       1665,  // NOLINT
-    7817,       1665, 7818,       1669, 7819,       1669,
-    7820,       1673, 7821,       1673, 7822,       1677,
-    7823,       1677, 7824,       1681,  // NOLINT
-    7825,       1681, 7826,       1685, 7827,       1685,
-    7828,       1689, 7829,       1689, 7835,       1585,
-    7840,       1693, 7841,       1693,  // NOLINT
-    7842,       1697, 7843,       1697, 7844,       1701,
-    7845,       1701, 7846,       1705, 7847,       1705,
-    7848,       1709, 7849,       1709,  // NOLINT
-    7850,       1713, 7851,       1713, 7852,       1717,
-    7853,       1717, 7854,       1721, 7855,       1721,
-    7856,       1725, 7857,       1725,  // NOLINT
-    7858,       1729, 7859,       1729, 7860,       1733,
-    7861,       1733, 7862,       1737, 7863,       1737,
-    7864,       1741, 7865,       1741,  // NOLINT
-    7866,       1745, 7867,       1745, 7868,       1749,
-    7869,       1749, 7870,       1753, 7871,       1753,
-    7872,       1757, 7873,       1757,  // NOLINT
-    7874,       1761, 7875,       1761, 7876,       1765,
-    7877,       1765, 7878,       1769, 7879,       1769,
-    7880,       1773, 7881,       1773,  // NOLINT
-    7882,       1777, 7883,       1777, 7884,       1781,
-    7885,       1781, 7886,       1785, 7887,       1785,
-    7888,       1789, 7889,       1789,  // NOLINT
-    7890,       1793, 7891,       1793, 7892,       1797,
-    7893,       1797, 7894,       1801, 7895,       1801,
-    7896,       1805, 7897,       1805,  // NOLINT
-    7898,       1809, 7899,       1809, 7900,       1813,
-    7901,       1813, 7902,       1817, 7903,       1817,
-    7904,       1821, 7905,       1821,  // NOLINT
-    7906,       1825, 7907,       1825, 7908,       1829,
-    7909,       1829, 7910,       1833, 7911,       1833,
-    7912,       1837, 7913,       1837,  // NOLINT
-    7914,       1841, 7915,       1841, 7916,       1845,
-    7917,       1845, 7918,       1849, 7919,       1849,
-    7920,       1853, 7921,       1853,  // NOLINT
-    7922,       1857, 7923,       1857, 7924,       1861,
-    7925,       1861, 7926,       1865, 7927,       1865,
-    7928,       1869, 7929,       1869,  // NOLINT
-    7930,       1873, 7931,       1873, 7932,       1877,
-    7933,       1877, 7934,       1881, 7935,       1881,
-    1073749760, 1885, 7943,       1889,  // NOLINT
-    1073749768, 1885, 7951,       1889, 1073749776, 1893,
-    7957,       1897, 1073749784, 1893, 7965,       1897,
-    1073749792, 1901, 7975,       1905,  // NOLINT
-    1073749800, 1901, 7983,       1905, 1073749808, 1909,
-    7991,       1913, 1073749816, 1909, 7999,       1913,
-    1073749824, 1917, 8005,       1921,  // NOLINT
-    1073749832, 1917, 8013,       1921, 8017,       1925,
-    8019,       1929, 8021,       1933, 8023,       1937,
-    8025,       1925, 8027,       1929,  // NOLINT
-    8029,       1933, 8031,       1937, 1073749856, 1941,
-    8039,       1945, 1073749864, 1941, 8047,       1945,
-    1073749872, 1949, 8049,       1953,  // NOLINT
-    1073749874, 1957, 8053,       1961, 1073749878, 1965,
-    8055,       1969, 1073749880, 1973, 8057,       1977,
-    1073749882, 1981, 8059,       1985,  // NOLINT
-    1073749884, 1989, 8061,       1993, 1073749936, 1997,
-    8113,       2001, 1073749944, 1997, 8121,       2001,
-    1073749946, 1949, 8123,       1953,  // NOLINT
-    8126,       749,  1073749960, 1957, 8139,       1961,
-    1073749968, 2005, 8145,       2009, 1073749976, 2005,
-    8153,       2009, 1073749978, 1965,  // NOLINT
-    8155,       1969, 1073749984, 2013, 8161,       2017,
-    8165,       2021, 1073749992, 2013, 8169,       2017,
-    1073749994, 1981, 8171,       1985,  // NOLINT
-    8172,       2021, 1073750008, 1973, 8185,       1977,
-    1073750010, 1989, 8187,       1993};                              // NOLINT
-static const uint16_t kEcma262UnCanonicalizeMultiStrings0Size = 507;  // NOLINT
+    1073741889, 1,    90,         5,    1073741921, 1,    122,        5,
+    181,        9,    1073742016, 13,   214,        17,   1073742040, 21,
+    222,        25,   1073742048, 13,   246,        17,   1073742072, 21,
+    254,        25,   255,        29,   256,        33,   257,        33,
+    258,        37,   259,        37,   260,        41,   261,        41,
+    262,        45,   263,        45,   264,        49,   265,        49,
+    266,        53,   267,        53,   268,        57,   269,        57,
+    270,        61,   271,        61,   272,        65,   273,        65,
+    274,        69,   275,        69,   276,        73,   277,        73,
+    278,        77,   279,        77,   280,        81,   281,        81,
+    282,        85,   283,        85,   284,        89,   285,        89,
+    286,        93,   287,        93,   288,        97,   289,        97,
+    290,        101,  291,        101,  292,        105,  293,        105,
+    294,        109,  295,        109,  296,        113,  297,        113,
+    298,        117,  299,        117,  300,        121,  301,        121,
+    302,        125,  303,        125,  306,        129,  307,        129,
+    308,        133,  309,        133,  310,        137,  311,        137,
+    313,        141,  314,        141,  315,        145,  316,        145,
+    317,        149,  318,        149,  319,        153,  320,        153,
+    321,        157,  322,        157,  323,        161,  324,        161,
+    325,        165,  326,        165,  327,        169,  328,        169,
+    330,        173,  331,        173,  332,        177,  333,        177,
+    334,        181,  335,        181,  336,        185,  337,        185,
+    338,        189,  339,        189,  340,        193,  341,        193,
+    342,        197,  343,        197,  344,        201,  345,        201,
+    346,        205,  347,        205,  348,        209,  349,        209,
+    350,        213,  351,        213,  352,        217,  353,        217,
+    354,        221,  355,        221,  356,        225,  357,        225,
+    358,        229,  359,        229,  360,        233,  361,        233,
+    362,        237,  363,        237,  364,        241,  365,        241,
+    366,        245,  367,        245,  368,        249,  369,        249,
+    370,        253,  371,        253,  372,        257,  373,        257,
+    374,        261,  375,        261,  376,        29,   377,        265,
+    378,        265,  379,        269,  380,        269,  381,        273,
+    382,        273,  384,        277,  385,        281,  386,        285,
+    387,        285,  388,        289,  389,        289,  390,        293,
+    391,        297,  392,        297,  1073742217, 301,  394,        305,
+    395,        309,  396,        309,  398,        313,  399,        317,
+    400,        321,  401,        325,  402,        325,  403,        329,
+    404,        333,  405,        337,  406,        341,  407,        345,
+    408,        349,  409,        349,  410,        353,  412,        357,
+    413,        361,  414,        365,  415,        369,  416,        373,
+    417,        373,  418,        377,  419,        377,  420,        381,
+    421,        381,  422,        385,  423,        389,  424,        389,
+    425,        393,  428,        397,  429,        397,  430,        401,
+    431,        405,  432,        405,  1073742257, 409,  434,        413,
+    435,        417,  436,        417,  437,        421,  438,        421,
+    439,        425,  440,        429,  441,        429,  444,        433,
+    445,        433,  447,        437,  452,        441,  453,        441,
+    454,        441,  455,        445,  456,        445,  457,        445,
+    458,        449,  459,        449,  460,        449,  461,        453,
+    462,        453,  463,        457,  464,        457,  465,        461,
+    466,        461,  467,        465,  468,        465,  469,        469,
+    470,        469,  471,        473,  472,        473,  473,        477,
+    474,        477,  475,        481,  476,        481,  477,        313,
+    478,        485,  479,        485,  480,        489,  481,        489,
+    482,        493,  483,        493,  484,        497,  485,        497,
+    486,        501,  487,        501,  488,        505,  489,        505,
+    490,        509,  491,        509,  492,        513,  493,        513,
+    494,        517,  495,        517,  497,        521,  498,        521,
+    499,        521,  500,        525,  501,        525,  502,        337,
+    503,        437,  504,        529,  505,        529,  506,        533,
+    507,        533,  508,        537,  509,        537,  510,        541,
+    511,        541,  512,        545,  513,        545,  514,        549,
+    515,        549,  516,        553,  517,        553,  518,        557,
+    519,        557,  520,        561,  521,        561,  522,        565,
+    523,        565,  524,        569,  525,        569,  526,        573,
+    527,        573,  528,        577,  529,        577,  530,        581,
+    531,        581,  532,        585,  533,        585,  534,        589,
+    535,        589,  536,        593,  537,        593,  538,        597,
+    539,        597,  540,        601,  541,        601,  542,        605,
+    543,        605,  544,        365,  546,        609,  547,        609,
+    548,        613,  549,        613,  550,        617,  551,        617,
+    552,        621,  553,        621,  554,        625,  555,        625,
+    556,        629,  557,        629,  558,        633,  559,        633,
+    560,        637,  561,        637,  562,        641,  563,        641,
+    570,        645,  571,        649,  572,        649,  573,        353,
+    574,        653,  1073742399, 657,  576,        661,  577,        665,
+    578,        665,  579,        277,  580,        669,  581,        673,
+    582,        677,  583,        677,  584,        681,  585,        681,
+    586,        685,  587,        685,  588,        689,  589,        689,
+    590,        693,  591,        693,  592,        697,  593,        701,
+    594,        705,  595,        281,  596,        293,  1073742422, 301,
+    599,        305,  601,        317,  603,        321,  604,        709,
+    608,        329,  609,        713,  611,        333,  613,        717,
+    614,        721,  616,        345,  617,        341,  619,        725,
+    620,        729,  623,        357,  625,        733,  626,        361,
+    629,        369,  637,        737,  640,        385,  643,        393,
+    647,        741,  648,        401,  649,        669,  1073742474, 409,
+    651,        413,  652,        673,  658,        425,  670,        745,
+    837,        749,  880,        753,  881,        753,  882,        757,
+    883,        757,  886,        761,  887,        761,  1073742715, 765,
+    893,        769,  895,        773,  902,        777,  1073742728, 781,
+    906,        785,  908,        789,  1073742734, 793,  911,        797,
+    913,        801,  914,        805,  1073742739, 809,  916,        813,
+    917,        817,  1073742742, 821,  919,        825,  920,        829,
+    921,        749,  922,        833,  923,        837,  924,        9,
+    1073742749, 841,  927,        845,  928,        849,  929,        853,
+    931,        857,  1073742756, 861,  933,        865,  934,        869,
+    1073742759, 873,  939,        877,  940,        777,  1073742765, 781,
+    943,        785,  945,        801,  946,        805,  1073742771, 809,
+    948,        813,  949,        817,  1073742774, 821,  951,        825,
+    952,        829,  953,        749,  954,        833,  955,        837,
+    956,        9,    1073742781, 841,  959,        845,  960,        849,
+    961,        853,  962,        857,  963,        857,  1073742788, 861,
+    965,        865,  966,        869,  1073742791, 873,  971,        877,
+    972,        789,  1073742797, 793,  974,        797,  975,        881,
+    976,        805,  977,        829,  981,        869,  982,        849,
+    983,        881,  984,        885,  985,        885,  986,        889,
+    987,        889,  988,        893,  989,        893,  990,        897,
+    991,        897,  992,        901,  993,        901,  994,        905,
+    995,        905,  996,        909,  997,        909,  998,        913,
+    999,        913,  1000,       917,  1001,       917,  1002,       921,
+    1003,       921,  1004,       925,  1005,       925,  1006,       929,
+    1007,       929,  1008,       833,  1009,       853,  1010,       933,
+    1011,       773,  1013,       817,  1015,       937,  1016,       937,
+    1017,       933,  1018,       941,  1019,       941,  1073742845, 765,
+    1023,       769,  1073742848, 945,  1039,       949,  1073742864, 953,
+    1071,       957,  1073742896, 953,  1103,       957,  1073742928, 945,
+    1119,       949,  1120,       961,  1121,       961,  1122,       965,
+    1123,       965,  1124,       969,  1125,       969,  1126,       973,
+    1127,       973,  1128,       977,  1129,       977,  1130,       981,
+    1131,       981,  1132,       985,  1133,       985,  1134,       989,
+    1135,       989,  1136,       993,  1137,       993,  1138,       997,
+    1139,       997,  1140,       1001, 1141,       1001, 1142,       1005,
+    1143,       1005, 1144,       1009, 1145,       1009, 1146,       1013,
+    1147,       1013, 1148,       1017, 1149,       1017, 1150,       1021,
+    1151,       1021, 1152,       1025, 1153,       1025, 1162,       1029,
+    1163,       1029, 1164,       1033, 1165,       1033, 1166,       1037,
+    1167,       1037, 1168,       1041, 1169,       1041, 1170,       1045,
+    1171,       1045, 1172,       1049, 1173,       1049, 1174,       1053,
+    1175,       1053, 1176,       1057, 1177,       1057, 1178,       1061,
+    1179,       1061, 1180,       1065, 1181,       1065, 1182,       1069,
+    1183,       1069, 1184,       1073, 1185,       1073, 1186,       1077,
+    1187,       1077, 1188,       1081, 1189,       1081, 1190,       1085,
+    1191,       1085, 1192,       1089, 1193,       1089, 1194,       1093,
+    1195,       1093, 1196,       1097, 1197,       1097, 1198,       1101,
+    1199,       1101, 1200,       1105, 1201,       1105, 1202,       1109,
+    1203,       1109, 1204,       1113, 1205,       1113, 1206,       1117,
+    1207,       1117, 1208,       1121, 1209,       1121, 1210,       1125,
+    1211,       1125, 1212,       1129, 1213,       1129, 1214,       1133,
+    1215,       1133, 1216,       1137, 1217,       1141, 1218,       1141,
+    1219,       1145, 1220,       1145, 1221,       1149, 1222,       1149,
+    1223,       1153, 1224,       1153, 1225,       1157, 1226,       1157,
+    1227,       1161, 1228,       1161, 1229,       1165, 1230,       1165,
+    1231,       1137, 1232,       1169, 1233,       1169, 1234,       1173,
+    1235,       1173, 1236,       1177, 1237,       1177, 1238,       1181,
+    1239,       1181, 1240,       1185, 1241,       1185, 1242,       1189,
+    1243,       1189, 1244,       1193, 1245,       1193, 1246,       1197,
+    1247,       1197, 1248,       1201, 1249,       1201, 1250,       1205,
+    1251,       1205, 1252,       1209, 1253,       1209, 1254,       1213,
+    1255,       1213, 1256,       1217, 1257,       1217, 1258,       1221,
+    1259,       1221, 1260,       1225, 1261,       1225, 1262,       1229,
+    1263,       1229, 1264,       1233, 1265,       1233, 1266,       1237,
+    1267,       1237, 1268,       1241, 1269,       1241, 1270,       1245,
+    1271,       1245, 1272,       1249, 1273,       1249, 1274,       1253,
+    1275,       1253, 1276,       1257, 1277,       1257, 1278,       1261,
+    1279,       1261, 1280,       1265, 1281,       1265, 1282,       1269,
+    1283,       1269, 1284,       1273, 1285,       1273, 1286,       1277,
+    1287,       1277, 1288,       1281, 1289,       1281, 1290,       1285,
+    1291,       1285, 1292,       1289, 1293,       1289, 1294,       1293,
+    1295,       1293, 1296,       1297, 1297,       1297, 1298,       1301,
+    1299,       1301, 1300,       1305, 1301,       1305, 1302,       1309,
+    1303,       1309, 1304,       1313, 1305,       1313, 1306,       1317,
+    1307,       1317, 1308,       1321, 1309,       1321, 1310,       1325,
+    1311,       1325, 1312,       1329, 1313,       1329, 1314,       1333,
+    1315,       1333, 1316,       1337, 1317,       1337, 1318,       1341,
+    1319,       1341, 1320,       1345, 1321,       1345, 1322,       1349,
+    1323,       1349, 1324,       1353, 1325,       1353, 1326,       1357,
+    1327,       1357, 1073743153, 1361, 1366,       1365, 1073743201, 1361,
+    1414,       1365, 1073746080, 1369, 4293,       1373, 4295,       1377,
+    4301,       1381, 7545,       1385, 7549,       1389, 7680,       1393,
+    7681,       1393, 7682,       1397, 7683,       1397, 7684,       1401,
+    7685,       1401, 7686,       1405, 7687,       1405, 7688,       1409,
+    7689,       1409, 7690,       1413, 7691,       1413, 7692,       1417,
+    7693,       1417, 7694,       1421, 7695,       1421, 7696,       1425,
+    7697,       1425, 7698,       1429, 7699,       1429, 7700,       1433,
+    7701,       1433, 7702,       1437, 7703,       1437, 7704,       1441,
+    7705,       1441, 7706,       1445, 7707,       1445, 7708,       1449,
+    7709,       1449, 7710,       1453, 7711,       1453, 7712,       1457,
+    7713,       1457, 7714,       1461, 7715,       1461, 7716,       1465,
+    7717,       1465, 7718,       1469, 7719,       1469, 7720,       1473,
+    7721,       1473, 7722,       1477, 7723,       1477, 7724,       1481,
+    7725,       1481, 7726,       1485, 7727,       1485, 7728,       1489,
+    7729,       1489, 7730,       1493, 7731,       1493, 7732,       1497,
+    7733,       1497, 7734,       1501, 7735,       1501, 7736,       1505,
+    7737,       1505, 7738,       1509, 7739,       1509, 7740,       1513,
+    7741,       1513, 7742,       1517, 7743,       1517, 7744,       1521,
+    7745,       1521, 7746,       1525, 7747,       1525, 7748,       1529,
+    7749,       1529, 7750,       1533, 7751,       1533, 7752,       1537,
+    7753,       1537, 7754,       1541, 7755,       1541, 7756,       1545,
+    7757,       1545, 7758,       1549, 7759,       1549, 7760,       1553,
+    7761,       1553, 7762,       1557, 7763,       1557, 7764,       1561,
+    7765,       1561, 7766,       1565, 7767,       1565, 7768,       1569,
+    7769,       1569, 7770,       1573, 7771,       1573, 7772,       1577,
+    7773,       1577, 7774,       1581, 7775,       1581, 7776,       1585,
+    7777,       1585, 7778,       1589, 7779,       1589, 7780,       1593,
+    7781,       1593, 7782,       1597, 7783,       1597, 7784,       1601,
+    7785,       1601, 7786,       1605, 7787,       1605, 7788,       1609,
+    7789,       1609, 7790,       1613, 7791,       1613, 7792,       1617,
+    7793,       1617, 7794,       1621, 7795,       1621, 7796,       1625,
+    7797,       1625, 7798,       1629, 7799,       1629, 7800,       1633,
+    7801,       1633, 7802,       1637, 7803,       1637, 7804,       1641,
+    7805,       1641, 7806,       1645, 7807,       1645, 7808,       1649,
+    7809,       1649, 7810,       1653, 7811,       1653, 7812,       1657,
+    7813,       1657, 7814,       1661, 7815,       1661, 7816,       1665,
+    7817,       1665, 7818,       1669, 7819,       1669, 7820,       1673,
+    7821,       1673, 7822,       1677, 7823,       1677, 7824,       1681,
+    7825,       1681, 7826,       1685, 7827,       1685, 7828,       1689,
+    7829,       1689, 7835,       1585, 7840,       1693, 7841,       1693,
+    7842,       1697, 7843,       1697, 7844,       1701, 7845,       1701,
+    7846,       1705, 7847,       1705, 7848,       1709, 7849,       1709,
+    7850,       1713, 7851,       1713, 7852,       1717, 7853,       1717,
+    7854,       1721, 7855,       1721, 7856,       1725, 7857,       1725,
+    7858,       1729, 7859,       1729, 7860,       1733, 7861,       1733,
+    7862,       1737, 7863,       1737, 7864,       1741, 7865,       1741,
+    7866,       1745, 7867,       1745, 7868,       1749, 7869,       1749,
+    7870,       1753, 7871,       1753, 7872,       1757, 7873,       1757,
+    7874,       1761, 7875,       1761, 7876,       1765, 7877,       1765,
+    7878,       1769, 7879,       1769, 7880,       1773, 7881,       1773,
+    7882,       1777, 7883,       1777, 7884,       1781, 7885,       1781,
+    7886,       1785, 7887,       1785, 7888,       1789, 7889,       1789,
+    7890,       1793, 7891,       1793, 7892,       1797, 7893,       1797,
+    7894,       1801, 7895,       1801, 7896,       1805, 7897,       1805,
+    7898,       1809, 7899,       1809, 7900,       1813, 7901,       1813,
+    7902,       1817, 7903,       1817, 7904,       1821, 7905,       1821,
+    7906,       1825, 7907,       1825, 7908,       1829, 7909,       1829,
+    7910,       1833, 7911,       1833, 7912,       1837, 7913,       1837,
+    7914,       1841, 7915,       1841, 7916,       1845, 7917,       1845,
+    7918,       1849, 7919,       1849, 7920,       1853, 7921,       1853,
+    7922,       1857, 7923,       1857, 7924,       1861, 7925,       1861,
+    7926,       1865, 7927,       1865, 7928,       1869, 7929,       1869,
+    7930,       1873, 7931,       1873, 7932,       1877, 7933,       1877,
+    7934,       1881, 7935,       1881, 1073749760, 1885, 7943,       1889,
+    1073749768, 1885, 7951,       1889, 1073749776, 1893, 7957,       1897,
+    1073749784, 1893, 7965,       1897, 1073749792, 1901, 7975,       1905,
+    1073749800, 1901, 7983,       1905, 1073749808, 1909, 7991,       1913,
+    1073749816, 1909, 7999,       1913, 1073749824, 1917, 8005,       1921,
+    1073749832, 1917, 8013,       1921, 8017,       1925, 8019,       1929,
+    8021,       1933, 8023,       1937, 8025,       1925, 8027,       1929,
+    8029,       1933, 8031,       1937, 1073749856, 1941, 8039,       1945,
+    1073749864, 1941, 8047,       1945, 1073749872, 1949, 8049,       1953,
+    1073749874, 1957, 8053,       1961, 1073749878, 1965, 8055,       1969,
+    1073749880, 1973, 8057,       1977, 1073749882, 1981, 8059,       1985,
+    1073749884, 1989, 8061,       1993, 1073749936, 1997, 8113,       2001,
+    1073749944, 1997, 8121,       2001, 1073749946, 1949, 8123,       1953,
+    8126,       749,  1073749960, 1957, 8139,       1961, 1073749968, 2005,
+    8145,       2009, 1073749976, 2005, 8153,       2009, 1073749978, 1965,
+    8155,       1969, 1073749984, 2013, 8161,       2017, 8165,       2021,
+    1073749992, 2013, 8169,       2017, 1073749994, 1981, 8171,       1985,
+    8172,       2021, 1073750008, 1973, 8185,       1977, 1073750010, 1989,
+    8187,       1993};
+static const uint16_t kEcma262UnCanonicalizeMultiStrings0Size = 507;
 static const MultiCharacterSpecialCase<2>
-    kEcma262UnCanonicalizeMultiStrings1[83] = {  // NOLINT
-        {{8498, 8526}},   {{8544, 8560}},   {{8559, 8575}},
-        {{8579, 8580}},  // NOLINT
-        {{9398, 9424}},   {{9423, 9449}},   {{11264, 11312}},
-        {{11310, 11358}},  // NOLINT
-        {{11360, 11361}}, {{619, 11362}},   {{7549, 11363}},
-        {{637, 11364}},  // NOLINT
-        {{570, 11365}},   {{574, 11366}},   {{11367, 11368}},
-        {{11369, 11370}},  // NOLINT
-        {{11371, 11372}}, {{593, 11373}},   {{625, 11374}},
-        {{592, 11375}},  // NOLINT
-        {{594, 11376}},   {{11378, 11379}}, {{11381, 11382}},
-        {{575, 11390}},  // NOLINT
-        {{576, 11391}},   {{11392, 11393}}, {{11394, 11395}},
-        {{11396, 11397}},  // NOLINT
-        {{11398, 11399}}, {{11400, 11401}}, {{11402, 11403}},
-        {{11404, 11405}},  // NOLINT
-        {{11406, 11407}}, {{11408, 11409}}, {{11410, 11411}},
-        {{11412, 11413}},  // NOLINT
-        {{11414, 11415}}, {{11416, 11417}}, {{11418, 11419}},
-        {{11420, 11421}},  // NOLINT
-        {{11422, 11423}}, {{11424, 11425}}, {{11426, 11427}},
-        {{11428, 11429}},  // NOLINT
-        {{11430, 11431}}, {{11432, 11433}}, {{11434, 11435}},
-        {{11436, 11437}},  // NOLINT
-        {{11438, 11439}}, {{11440, 11441}}, {{11442, 11443}},
-        {{11444, 11445}},  // NOLINT
-        {{11446, 11447}}, {{11448, 11449}}, {{11450, 11451}},
-        {{11452, 11453}},  // NOLINT
-        {{11454, 11455}}, {{11456, 11457}}, {{11458, 11459}},
-        {{11460, 11461}},  // NOLINT
-        {{11462, 11463}}, {{11464, 11465}}, {{11466, 11467}},
-        {{11468, 11469}},  // NOLINT
-        {{11470, 11471}}, {{11472, 11473}}, {{11474, 11475}},
-        {{11476, 11477}},  // NOLINT
-        {{11478, 11479}}, {{11480, 11481}}, {{11482, 11483}},
-        {{11484, 11485}},  // NOLINT
-        {{11486, 11487}}, {{11488, 11489}}, {{11490, 11491}},
-        {{11499, 11500}},  // NOLINT
-        {{11501, 11502}}, {{11506, 11507}}, {{4256, 11520}},
-        {{4293, 11557}},                                       // NOLINT
-        {{4295, 11559}},  {{4301, 11565}},  {{kSentinel}}};    // NOLINT
-static const uint16_t kEcma262UnCanonicalizeTable1Size = 149;  // NOLINT
+    kEcma262UnCanonicalizeMultiStrings1[83] = {
+        {{8498, 8526}},   {{8544, 8560}},   {{8559, 8575}},   {{8579, 8580}},
+        {{9398, 9424}},   {{9423, 9449}},   {{11264, 11312}}, {{11310, 11358}},
+        {{11360, 11361}}, {{619, 11362}},   {{7549, 11363}},  {{637, 11364}},
+        {{570, 11365}},   {{574, 11366}},   {{11367, 11368}}, {{11369, 11370}},
+        {{11371, 11372}}, {{593, 11373}},   {{625, 11374}},   {{592, 11375}},
+        {{594, 11376}},   {{11378, 11379}}, {{11381, 11382}}, {{575, 11390}},
+        {{576, 11391}},   {{11392, 11393}}, {{11394, 11395}}, {{11396, 11397}},
+        {{11398, 11399}}, {{11400, 11401}}, {{11402, 11403}}, {{11404, 11405}},
+        {{11406, 11407}}, {{11408, 11409}}, {{11410, 11411}}, {{11412, 11413}},
+        {{11414, 11415}}, {{11416, 11417}}, {{11418, 11419}}, {{11420, 11421}},
+        {{11422, 11423}}, {{11424, 11425}}, {{11426, 11427}}, {{11428, 11429}},
+        {{11430, 11431}}, {{11432, 11433}}, {{11434, 11435}}, {{11436, 11437}},
+        {{11438, 11439}}, {{11440, 11441}}, {{11442, 11443}}, {{11444, 11445}},
+        {{11446, 11447}}, {{11448, 11449}}, {{11450, 11451}}, {{11452, 11453}},
+        {{11454, 11455}}, {{11456, 11457}}, {{11458, 11459}}, {{11460, 11461}},
+        {{11462, 11463}}, {{11464, 11465}}, {{11466, 11467}}, {{11468, 11469}},
+        {{11470, 11471}}, {{11472, 11473}}, {{11474, 11475}}, {{11476, 11477}},
+        {{11478, 11479}}, {{11480, 11481}}, {{11482, 11483}}, {{11484, 11485}},
+        {{11486, 11487}}, {{11488, 11489}}, {{11490, 11491}}, {{11499, 11500}},
+        {{11501, 11502}}, {{11506, 11507}}, {{4256, 11520}},  {{4293, 11557}},
+        {{4295, 11559}},  {{4301, 11565}},  {{kSentinel}}};
+static const uint16_t kEcma262UnCanonicalizeTable1Size = 149;
 static const int32_t kEcma262UnCanonicalizeTable1[298] = {
     306,        1,   334,        1,   1073742176, 5,   367,  9,
-    1073742192, 5,   383,        9,   387,        13,  388,  13,  // NOLINT
+    1073742192, 5,   383,        9,   387,        13,  388,  13,
     1073743030, 17,  1231,       21,  1073743056, 17,  1257, 21,
-    1073744896, 25,  3118,       29,  1073744944, 25,  3166, 29,  // NOLINT
+    1073744896, 25,  3118,       29,  1073744944, 25,  3166, 29,
     3168,       33,  3169,       33,  3170,       37,  3171, 41,
-    3172,       45,  3173,       49,  3174,       53,  3175, 57,  // NOLINT
+    3172,       45,  3173,       49,  3174,       53,  3175, 57,
     3176,       57,  3177,       61,  3178,       61,  3179, 65,
-    3180,       65,  3181,       69,  3182,       73,  3183, 77,  // NOLINT
+    3180,       65,  3181,       69,  3182,       73,  3183, 77,
     3184,       81,  3186,       85,  3187,       85,  3189, 89,
-    3190,       89,  1073745022, 93,  3199,       97,  3200, 101,  // NOLINT
+    3190,       89,  1073745022, 93,  3199,       97,  3200, 101,
     3201,       101, 3202,       105, 3203,       105, 3204, 109,
-    3205,       109, 3206,       113, 3207,       113, 3208, 117,  // NOLINT
+    3205,       109, 3206,       113, 3207,       113, 3208, 117,
     3209,       117, 3210,       121, 3211,       121, 3212, 125,
-    3213,       125, 3214,       129, 3215,       129, 3216, 133,  // NOLINT
+    3213,       125, 3214,       129, 3215,       129, 3216, 133,
     3217,       133, 3218,       137, 3219,       137, 3220, 141,
-    3221,       141, 3222,       145, 3223,       145, 3224, 149,  // NOLINT
+    3221,       141, 3222,       145, 3223,       145, 3224, 149,
     3225,       149, 3226,       153, 3227,       153, 3228, 157,
-    3229,       157, 3230,       161, 3231,       161, 3232, 165,  // NOLINT
+    3229,       157, 3230,       161, 3231,       161, 3232, 165,
     3233,       165, 3234,       169, 3235,       169, 3236, 173,
-    3237,       173, 3238,       177, 3239,       177, 3240, 181,  // NOLINT
+    3237,       173, 3238,       177, 3239,       177, 3240, 181,
     3241,       181, 3242,       185, 3243,       185, 3244, 189,
-    3245,       189, 3246,       193, 3247,       193, 3248, 197,  // NOLINT
+    3245,       189, 3246,       193, 3247,       193, 3248, 197,
     3249,       197, 3250,       201, 3251,       201, 3252, 205,
-    3253,       205, 3254,       209, 3255,       209, 3256, 213,  // NOLINT
+    3253,       205, 3254,       209, 3255,       209, 3256, 213,
     3257,       213, 3258,       217, 3259,       217, 3260, 221,
-    3261,       221, 3262,       225, 3263,       225, 3264, 229,  // NOLINT
+    3261,       221, 3262,       225, 3263,       225, 3264, 229,
     3265,       229, 3266,       233, 3267,       233, 3268, 237,
-    3269,       237, 3270,       241, 3271,       241, 3272, 245,  // NOLINT
+    3269,       237, 3270,       241, 3271,       241, 3272, 245,
     3273,       245, 3274,       249, 3275,       249, 3276, 253,
-    3277,       253, 3278,       257, 3279,       257, 3280, 261,  // NOLINT
+    3277,       253, 3278,       257, 3279,       257, 3280, 261,
     3281,       261, 3282,       265, 3283,       265, 3284, 269,
-    3285,       269, 3286,       273, 3287,       273, 3288, 277,  // NOLINT
+    3285,       269, 3286,       273, 3287,       273, 3288, 277,
     3289,       277, 3290,       281, 3291,       281, 3292, 285,
-    3293,       285, 3294,       289, 3295,       289, 3296, 293,  // NOLINT
+    3293,       285, 3294,       289, 3295,       289, 3296, 293,
     3297,       293, 3298,       297, 3299,       297, 3307, 301,
-    3308,       301, 3309,       305, 3310,       305, 3314, 309,  // NOLINT
+    3308,       301, 3309,       305, 3310,       305, 3314, 309,
     3315,       309, 1073745152, 313, 3365,       317, 3367, 321,
-    3373,       325};                                                // NOLINT
-static const uint16_t kEcma262UnCanonicalizeMultiStrings1Size = 83;  // NOLINT
+    3373,       325};
+static const uint16_t kEcma262UnCanonicalizeMultiStrings1Size = 83;
 static const MultiCharacterSpecialCase<2>
-    kEcma262UnCanonicalizeMultiStrings5[104] = {  // NOLINT
-        {{42560, 42561}}, {{42562, 42563}},
-        {{42564, 42565}}, {{42566, 42567}},  // NOLINT
-        {{42568, 42569}}, {{42570, 42571}},
-        {{42572, 42573}}, {{42574, 42575}},  // NOLINT
-        {{42576, 42577}}, {{42578, 42579}},
-        {{42580, 42581}}, {{42582, 42583}},  // NOLINT
-        {{42584, 42585}}, {{42586, 42587}},
-        {{42588, 42589}}, {{42590, 42591}},  // NOLINT
-        {{42592, 42593}}, {{42594, 42595}},
-        {{42596, 42597}}, {{42598, 42599}},  // NOLINT
-        {{42600, 42601}}, {{42602, 42603}},
-        {{42604, 42605}}, {{42624, 42625}},  // NOLINT
-        {{42626, 42627}}, {{42628, 42629}},
-        {{42630, 42631}}, {{42632, 42633}},  // NOLINT
-        {{42634, 42635}}, {{42636, 42637}},
-        {{42638, 42639}}, {{42640, 42641}},  // NOLINT
-        {{42642, 42643}}, {{42644, 42645}},
-        {{42646, 42647}}, {{42648, 42649}},  // NOLINT
-        {{42650, 42651}}, {{42786, 42787}},
-        {{42788, 42789}}, {{42790, 42791}},  // NOLINT
-        {{42792, 42793}}, {{42794, 42795}},
-        {{42796, 42797}}, {{42798, 42799}},  // NOLINT
-        {{42802, 42803}}, {{42804, 42805}},
-        {{42806, 42807}}, {{42808, 42809}},  // NOLINT
-        {{42810, 42811}}, {{42812, 42813}},
-        {{42814, 42815}}, {{42816, 42817}},  // NOLINT
-        {{42818, 42819}}, {{42820, 42821}},
-        {{42822, 42823}}, {{42824, 42825}},  // NOLINT
-        {{42826, 42827}}, {{42828, 42829}},
-        {{42830, 42831}}, {{42832, 42833}},  // NOLINT
-        {{42834, 42835}}, {{42836, 42837}},
-        {{42838, 42839}}, {{42840, 42841}},  // NOLINT
-        {{42842, 42843}}, {{42844, 42845}},
-        {{42846, 42847}}, {{42848, 42849}},  // NOLINT
-        {{42850, 42851}}, {{42852, 42853}},
-        {{42854, 42855}}, {{42856, 42857}},  // NOLINT
-        {{42858, 42859}}, {{42860, 42861}},
-        {{42862, 42863}}, {{42873, 42874}},  // NOLINT
-        {{42875, 42876}}, {{7545, 42877}},
-        {{42878, 42879}}, {{42880, 42881}},  // NOLINT
-        {{42882, 42883}}, {{42884, 42885}},
-        {{42886, 42887}}, {{42891, 42892}},  // NOLINT
-        {{613, 42893}},   {{42896, 42897}},
-        {{42898, 42899}}, {{42902, 42903}},  // NOLINT
-        {{42904, 42905}}, {{42906, 42907}},
-        {{42908, 42909}}, {{42910, 42911}},  // NOLINT
-        {{42912, 42913}}, {{42914, 42915}},
-        {{42916, 42917}}, {{42918, 42919}},  // NOLINT
-        {{42920, 42921}}, {{614, 42922}},
-        {{604, 42923}},   {{609, 42924}},  // NOLINT
-        {{620, 42925}},   {{670, 42928}},
-        {{647, 42929}},   {{kSentinel}}};                      // NOLINT
-static const uint16_t kEcma262UnCanonicalizeTable5Size = 198;  // NOLINT
-static const int32_t
-    kEcma262UnCanonicalizeTable5[396] =
-        {1600, 1,   1601, 1,   1602, 5,   1603, 5,
-         1604, 9,   1605, 9,   1606, 13,  1607, 13,  // NOLINT
-         1608, 17,  1609, 17,  1610, 21,  1611, 21,
-         1612, 25,  1613, 25,  1614, 29,  1615, 29,  // NOLINT
-         1616, 33,  1617, 33,  1618, 37,  1619, 37,
-         1620, 41,  1621, 41,  1622, 45,  1623, 45,  // NOLINT
-         1624, 49,  1625, 49,  1626, 53,  1627, 53,
-         1628, 57,  1629, 57,  1630, 61,  1631, 61,  // NOLINT
-         1632, 65,  1633, 65,  1634, 69,  1635, 69,
-         1636, 73,  1637, 73,  1638, 77,  1639, 77,  // NOLINT
-         1640, 81,  1641, 81,  1642, 85,  1643, 85,
-         1644, 89,  1645, 89,  1664, 93,  1665, 93,  // NOLINT
-         1666, 97,  1667, 97,  1668, 101, 1669, 101,
-         1670, 105, 1671, 105, 1672, 109, 1673, 109,  // NOLINT
-         1674, 113, 1675, 113, 1676, 117, 1677, 117,
-         1678, 121, 1679, 121, 1680, 125, 1681, 125,  // NOLINT
-         1682, 129, 1683, 129, 1684, 133, 1685, 133,
-         1686, 137, 1687, 137, 1688, 141, 1689, 141,  // NOLINT
-         1690, 145, 1691, 145, 1826, 149, 1827, 149,
-         1828, 153, 1829, 153, 1830, 157, 1831, 157,  // NOLINT
-         1832, 161, 1833, 161, 1834, 165, 1835, 165,
-         1836, 169, 1837, 169, 1838, 173, 1839, 173,  // NOLINT
-         1842, 177, 1843, 177, 1844, 181, 1845, 181,
-         1846, 185, 1847, 185, 1848, 189, 1849, 189,  // NOLINT
-         1850, 193, 1851, 193, 1852, 197, 1853, 197,
-         1854, 201, 1855, 201, 1856, 205, 1857, 205,  // NOLINT
-         1858, 209, 1859, 209, 1860, 213, 1861, 213,
-         1862, 217, 1863, 217, 1864, 221, 1865, 221,  // NOLINT
-         1866, 225, 1867, 225, 1868, 229, 1869, 229,
-         1870, 233, 1871, 233, 1872, 237, 1873, 237,  // NOLINT
-         1874, 241, 1875, 241, 1876, 245, 1877, 245,
-         1878, 249, 1879, 249, 1880, 253, 1881, 253,  // NOLINT
-         1882, 257, 1883, 257, 1884, 261, 1885, 261,
-         1886, 265, 1887, 265, 1888, 269, 1889, 269,  // NOLINT
-         1890, 273, 1891, 273, 1892, 277, 1893, 277,
-         1894, 281, 1895, 281, 1896, 285, 1897, 285,  // NOLINT
-         1898, 289, 1899, 289, 1900, 293, 1901, 293,
-         1902, 297, 1903, 297, 1913, 301, 1914, 301,  // NOLINT
-         1915, 305, 1916, 305, 1917, 309, 1918, 313,
-         1919, 313, 1920, 317, 1921, 317, 1922, 321,  // NOLINT
-         1923, 321, 1924, 325, 1925, 325, 1926, 329,
-         1927, 329, 1931, 333, 1932, 333, 1933, 337,  // NOLINT
-         1936, 341, 1937, 341, 1938, 345, 1939, 345,
-         1942, 349, 1943, 349, 1944, 353, 1945, 353,  // NOLINT
-         1946, 357, 1947, 357, 1948, 361, 1949, 361,
-         1950, 365, 1951, 365, 1952, 369, 1953, 369,  // NOLINT
-         1954, 373, 1955, 373, 1956, 377, 1957, 377,
-         1958, 381, 1959, 381, 1960, 385, 1961, 385,  // NOLINT
-         1962, 389, 1963, 393, 1964, 397, 1965, 401,
-         1968, 405, 1969, 409};                                       // NOLINT
-static const uint16_t kEcma262UnCanonicalizeMultiStrings5Size = 104;  // NOLINT
+    kEcma262UnCanonicalizeMultiStrings5[104] = {
+        {{42560, 42561}}, {{42562, 42563}}, {{42564, 42565}}, {{42566, 42567}},
+        {{42568, 42569}}, {{42570, 42571}}, {{42572, 42573}}, {{42574, 42575}},
+        {{42576, 42577}}, {{42578, 42579}}, {{42580, 42581}}, {{42582, 42583}},
+        {{42584, 42585}}, {{42586, 42587}}, {{42588, 42589}}, {{42590, 42591}},
+        {{42592, 42593}}, {{42594, 42595}}, {{42596, 42597}}, {{42598, 42599}},
+        {{42600, 42601}}, {{42602, 42603}}, {{42604, 42605}}, {{42624, 42625}},
+        {{42626, 42627}}, {{42628, 42629}}, {{42630, 42631}}, {{42632, 42633}},
+        {{42634, 42635}}, {{42636, 42637}}, {{42638, 42639}}, {{42640, 42641}},
+        {{42642, 42643}}, {{42644, 42645}}, {{42646, 42647}}, {{42648, 42649}},
+        {{42650, 42651}}, {{42786, 42787}}, {{42788, 42789}}, {{42790, 42791}},
+        {{42792, 42793}}, {{42794, 42795}}, {{42796, 42797}}, {{42798, 42799}},
+        {{42802, 42803}}, {{42804, 42805}}, {{42806, 42807}}, {{42808, 42809}},
+        {{42810, 42811}}, {{42812, 42813}}, {{42814, 42815}}, {{42816, 42817}},
+        {{42818, 42819}}, {{42820, 42821}}, {{42822, 42823}}, {{42824, 42825}},
+        {{42826, 42827}}, {{42828, 42829}}, {{42830, 42831}}, {{42832, 42833}},
+        {{42834, 42835}}, {{42836, 42837}}, {{42838, 42839}}, {{42840, 42841}},
+        {{42842, 42843}}, {{42844, 42845}}, {{42846, 42847}}, {{42848, 42849}},
+        {{42850, 42851}}, {{42852, 42853}}, {{42854, 42855}}, {{42856, 42857}},
+        {{42858, 42859}}, {{42860, 42861}}, {{42862, 42863}}, {{42873, 42874}},
+        {{42875, 42876}}, {{7545, 42877}},  {{42878, 42879}}, {{42880, 42881}},
+        {{42882, 42883}}, {{42884, 42885}}, {{42886, 42887}}, {{42891, 42892}},
+        {{613, 42893}},   {{42896, 42897}}, {{42898, 42899}}, {{42902, 42903}},
+        {{42904, 42905}}, {{42906, 42907}}, {{42908, 42909}}, {{42910, 42911}},
+        {{42912, 42913}}, {{42914, 42915}}, {{42916, 42917}}, {{42918, 42919}},
+        {{42920, 42921}}, {{614, 42922}},   {{604, 42923}},   {{609, 42924}},
+        {{620, 42925}},   {{670, 42928}},   {{647, 42929}},   {{kSentinel}}};
+static const uint16_t kEcma262UnCanonicalizeTable5Size = 198;
+static const int32_t kEcma262UnCanonicalizeTable5[396] = {
+    1600, 1,   1601, 1,   1602, 5,   1603, 5,   1604, 9,   1605, 9,   1606, 13,
+    1607, 13,  1608, 17,  1609, 17,  1610, 21,  1611, 21,  1612, 25,  1613, 25,
+    1614, 29,  1615, 29,  1616, 33,  1617, 33,  1618, 37,  1619, 37,  1620, 41,
+    1621, 41,  1622, 45,  1623, 45,  1624, 49,  1625, 49,  1626, 53,  1627, 53,
+    1628, 57,  1629, 57,  1630, 61,  1631, 61,  1632, 65,  1633, 65,  1634, 69,
+    1635, 69,  1636, 73,  1637, 73,  1638, 77,  1639, 77,  1640, 81,  1641, 81,
+    1642, 85,  1643, 85,  1644, 89,  1645, 89,  1664, 93,  1665, 93,  1666, 97,
+    1667, 97,  1668, 101, 1669, 101, 1670, 105, 1671, 105, 1672, 109, 1673, 109,
+    1674, 113, 1675, 113, 1676, 117, 1677, 117, 1678, 121, 1679, 121, 1680, 125,
+    1681, 125, 1682, 129, 1683, 129, 1684, 133, 1685, 133, 1686, 137, 1687, 137,
+    1688, 141, 1689, 141, 1690, 145, 1691, 145, 1826, 149, 1827, 149, 1828, 153,
+    1829, 153, 1830, 157, 1831, 157, 1832, 161, 1833, 161, 1834, 165, 1835, 165,
+    1836, 169, 1837, 169, 1838, 173, 1839, 173, 1842, 177, 1843, 177, 1844, 181,
+    1845, 181, 1846, 185, 1847, 185, 1848, 189, 1849, 189, 1850, 193, 1851, 193,
+    1852, 197, 1853, 197, 1854, 201, 1855, 201, 1856, 205, 1857, 205, 1858, 209,
+    1859, 209, 1860, 213, 1861, 213, 1862, 217, 1863, 217, 1864, 221, 1865, 221,
+    1866, 225, 1867, 225, 1868, 229, 1869, 229, 1870, 233, 1871, 233, 1872, 237,
+    1873, 237, 1874, 241, 1875, 241, 1876, 245, 1877, 245, 1878, 249, 1879, 249,
+    1880, 253, 1881, 253, 1882, 257, 1883, 257, 1884, 261, 1885, 261, 1886, 265,
+    1887, 265, 1888, 269, 1889, 269, 1890, 273, 1891, 273, 1892, 277, 1893, 277,
+    1894, 281, 1895, 281, 1896, 285, 1897, 285, 1898, 289, 1899, 289, 1900, 293,
+    1901, 293, 1902, 297, 1903, 297, 1913, 301, 1914, 301, 1915, 305, 1916, 305,
+    1917, 309, 1918, 313, 1919, 313, 1920, 317, 1921, 317, 1922, 321, 1923, 321,
+    1924, 325, 1925, 325, 1926, 329, 1927, 329, 1931, 333, 1932, 333, 1933, 337,
+    1936, 341, 1937, 341, 1938, 345, 1939, 345, 1942, 349, 1943, 349, 1944, 353,
+    1945, 353, 1946, 357, 1947, 357, 1948, 361, 1949, 361, 1950, 365, 1951, 365,
+    1952, 369, 1953, 369, 1954, 373, 1955, 373, 1956, 377, 1957, 377, 1958, 381,
+    1959, 381, 1960, 385, 1961, 385, 1962, 389, 1963, 393, 1964, 397, 1965, 401,
+    1968, 405, 1969, 409};
+static const uint16_t kEcma262UnCanonicalizeMultiStrings5Size = 104;
 static const MultiCharacterSpecialCase<2>
-    kEcma262UnCanonicalizeMultiStrings7[3] = {  // NOLINT
-        {{65313, 65345}},
-        {{65338, 65370}},
-        {{kSentinel}}};                                      // NOLINT
-static const uint16_t kEcma262UnCanonicalizeTable7Size = 4;  // NOLINT
-static const int32_t kEcma262UnCanonicalizeTable7[8] = {
-    1073749793, 1, 7994, 5, 1073749825, 1, 8026, 5};                // NOLINT
-static const uint16_t kEcma262UnCanonicalizeMultiStrings7Size = 3;  // NOLINT
+    kEcma262UnCanonicalizeMultiStrings7[3] = {
+        {{65313, 65345}}, {{65338, 65370}}, {{kSentinel}}};
+static const uint16_t kEcma262UnCanonicalizeTable7Size = 4;
+static const int32_t kEcma262UnCanonicalizeTable7[8] = {1073749793, 1, 7994, 5,
+                                                        1073749825, 1, 8026, 5};
+static const uint16_t kEcma262UnCanonicalizeMultiStrings7Size = 3;
 int Ecma262UnCanonicalize::Convert(uchar c, uchar n, uchar* result,
                                    bool* allow_caching_ptr) {
   int chunk_index = c >> 13;
@@ -3057,46 +2485,43 @@ int Ecma262UnCanonicalize::Convert(uchar c, uchar n, uchar* result,
 }
 
 static const MultiCharacterSpecialCase<1>
-    kCanonicalizationRangeMultiStrings0[1] = {                // NOLINT
-        {{kSentinel}}};                                       // NOLINT
-static const uint16_t kCanonicalizationRangeTable0Size = 70;  // NOLINT
+    kCanonicalizationRangeMultiStrings0[1] = {{{kSentinel}}};
+static const uint16_t kCanonicalizationRangeTable0Size = 70;
 static const int32_t kCanonicalizationRangeTable0[140] = {
     1073741889, 100, 90,   0, 1073741921, 100, 122,  0,
-    1073742016, 88,  214,  0, 1073742040, 24,  222,  0,  // NOLINT
+    1073742016, 88,  214,  0, 1073742040, 24,  222,  0,
     1073742048, 88,  246,  0, 1073742072, 24,  254,  0,
-    1073742715, 8,   893,  0, 1073742728, 8,   906,  0,  // NOLINT
+    1073742715, 8,   893,  0, 1073742728, 8,   906,  0,
     1073742749, 8,   927,  0, 1073742759, 16,  939,  0,
-    1073742765, 8,   943,  0, 1073742781, 8,   959,  0,  // NOLINT
+    1073742765, 8,   943,  0, 1073742781, 8,   959,  0,
     1073742791, 16,  971,  0, 1073742845, 8,   1023, 0,
-    1073742848, 60,  1039, 0, 1073742864, 124, 1071, 0,  // NOLINT
+    1073742848, 60,  1039, 0, 1073742864, 124, 1071, 0,
     1073742896, 124, 1103, 0, 1073742928, 60,  1119, 0,
-    1073743153, 148, 1366, 0, 1073743201, 148, 1414, 0,  // NOLINT
+    1073743153, 148, 1366, 0, 1073743201, 148, 1414, 0,
     1073746080, 148, 4293, 0, 1073749760, 28,  7943, 0,
-    1073749768, 28,  7951, 0, 1073749776, 20,  7957, 0,  // NOLINT
+    1073749768, 28,  7951, 0, 1073749776, 20,  7957, 0,
     1073749784, 20,  7965, 0, 1073749792, 28,  7975, 0,
-    1073749800, 28,  7983, 0, 1073749808, 28,  7991, 0,  // NOLINT
+    1073749800, 28,  7983, 0, 1073749808, 28,  7991, 0,
     1073749816, 28,  7999, 0, 1073749824, 20,  8005, 0,
-    1073749832, 20,  8013, 0, 1073749856, 28,  8039, 0,  // NOLINT
+    1073749832, 20,  8013, 0, 1073749856, 28,  8039, 0,
     1073749864, 28,  8047, 0, 1073749874, 12,  8053, 0,
-    1073749960, 12,  8139, 0};                                      // NOLINT
-static const uint16_t kCanonicalizationRangeMultiStrings0Size = 1;  // NOLINT
+    1073749960, 12,  8139, 0};
+static const uint16_t kCanonicalizationRangeMultiStrings0Size = 1;
 static const MultiCharacterSpecialCase<1>
-    kCanonicalizationRangeMultiStrings1[1] = {                // NOLINT
-        {{kSentinel}}};                                       // NOLINT
-static const uint16_t kCanonicalizationRangeTable1Size = 14;  // NOLINT
+    kCanonicalizationRangeMultiStrings1[1] = {{{kSentinel}}};
+static const uint16_t kCanonicalizationRangeTable1Size = 14;
 static const int32_t kCanonicalizationRangeTable1[28] = {
     1073742176, 60,  367,  0, 1073742192, 60,  383,  0,
-    1073743030, 100, 1231, 0, 1073743056, 100, 1257, 0,  // NOLINT
+    1073743030, 100, 1231, 0, 1073743056, 100, 1257, 0,
     1073744896, 184, 3118, 0, 1073744944, 184, 3166, 0,
-    1073745152, 148, 3365, 0};                                      // NOLINT
-static const uint16_t kCanonicalizationRangeMultiStrings1Size = 1;  // NOLINT
+    1073745152, 148, 3365, 0};
+static const uint16_t kCanonicalizationRangeMultiStrings1Size = 1;
 static const MultiCharacterSpecialCase<1>
-    kCanonicalizationRangeMultiStrings7[1] = {               // NOLINT
-        {{kSentinel}}};                                      // NOLINT
-static const uint16_t kCanonicalizationRangeTable7Size = 4;  // NOLINT
+    kCanonicalizationRangeMultiStrings7[1] = {{{kSentinel}}};
+static const uint16_t kCanonicalizationRangeTable7Size = 4;
 static const int32_t kCanonicalizationRangeTable7[8] = {
-    1073749793, 100, 7994, 0, 1073749825, 100, 8026, 0};            // NOLINT
-static const uint16_t kCanonicalizationRangeMultiStrings7Size = 1;  // NOLINT
+    1073749793, 100, 7994, 0, 1073749825, 100, 8026, 0};
+static const uint16_t kCanonicalizationRangeMultiStrings7Size = 1;
 int CanonicalizationRange::Convert(uchar c, uchar n, uchar* result,
                                    bool* allow_caching_ptr) {
   int chunk_index = c >> 13;
@@ -3121,71 +2546,63 @@ int CanonicalizationRange::Convert(uchar c, uchar n, uchar* result,
 const uchar UnicodeData::kMaxCodePoint = 0xFFFD;
 
 int UnicodeData::GetByteCount() {
-  return kUppercaseTable0Size * sizeof(int32_t)      // NOLINT
-         + kUppercaseTable1Size * sizeof(int32_t)    // NOLINT
-         + kUppercaseTable5Size * sizeof(int32_t)    // NOLINT
-         + kUppercaseTable7Size * sizeof(int32_t)    // NOLINT
-         + kLetterTable0Size * sizeof(int32_t)       // NOLINT
-         + kLetterTable1Size * sizeof(int32_t)       // NOLINT
-         + kLetterTable2Size * sizeof(int32_t)       // NOLINT
-         + kLetterTable3Size * sizeof(int32_t)       // NOLINT
-         + kLetterTable4Size * sizeof(int32_t)       // NOLINT
-         + kLetterTable5Size * sizeof(int32_t)       // NOLINT
-         + kLetterTable6Size * sizeof(int32_t)       // NOLINT
-         + kLetterTable7Size * sizeof(int32_t)       // NOLINT
-         + kID_StartTable0Size * sizeof(int32_t)     // NOLINT
-         + kID_StartTable1Size * sizeof(int32_t)     // NOLINT
-         + kID_StartTable2Size * sizeof(int32_t)     // NOLINT
-         + kID_StartTable3Size * sizeof(int32_t)     // NOLINT
-         + kID_StartTable4Size * sizeof(int32_t)     // NOLINT
-         + kID_StartTable5Size * sizeof(int32_t)     // NOLINT
-         + kID_StartTable6Size * sizeof(int32_t)     // NOLINT
-         + kID_StartTable7Size * sizeof(int32_t)     // NOLINT
-         + kID_ContinueTable0Size * sizeof(int32_t)  // NOLINT
-         + kID_ContinueTable1Size * sizeof(int32_t)  // NOLINT
-         + kID_ContinueTable5Size * sizeof(int32_t)  // NOLINT
-         + kID_ContinueTable7Size * sizeof(int32_t)  // NOLINT
-         + kWhiteSpaceTable0Size * sizeof(int32_t)   // NOLINT
-         + kWhiteSpaceTable1Size * sizeof(int32_t)   // NOLINT
-         + kWhiteSpaceTable7Size * sizeof(int32_t)   // NOLINT
-         + kToLowercaseMultiStrings0Size *
-               sizeof(MultiCharacterSpecialCase<2>)  // NOLINT
-         + kToLowercaseMultiStrings1Size *
-               sizeof(MultiCharacterSpecialCase<1>)  // NOLINT
-         + kToLowercaseMultiStrings5Size *
-               sizeof(MultiCharacterSpecialCase<1>)  // NOLINT
-         + kToLowercaseMultiStrings7Size *
-               sizeof(MultiCharacterSpecialCase<1>)  // NOLINT
-         + kToUppercaseMultiStrings0Size *
-               sizeof(MultiCharacterSpecialCase<3>)  // NOLINT
-         + kToUppercaseMultiStrings1Size *
-               sizeof(MultiCharacterSpecialCase<1>)  // NOLINT
-         + kToUppercaseMultiStrings5Size *
-               sizeof(MultiCharacterSpecialCase<1>)  // NOLINT
-         + kToUppercaseMultiStrings7Size *
-               sizeof(MultiCharacterSpecialCase<3>)  // NOLINT
-         + kEcma262CanonicalizeMultiStrings0Size *
-               sizeof(MultiCharacterSpecialCase<1>)  // NOLINT
-         + kEcma262CanonicalizeMultiStrings1Size *
-               sizeof(MultiCharacterSpecialCase<1>)  // NOLINT
-         + kEcma262CanonicalizeMultiStrings5Size *
-               sizeof(MultiCharacterSpecialCase<1>)  // NOLINT
-         + kEcma262CanonicalizeMultiStrings7Size *
-               sizeof(MultiCharacterSpecialCase<1>)  // NOLINT
-         + kEcma262UnCanonicalizeMultiStrings0Size *
-               sizeof(MultiCharacterSpecialCase<4>)  // NOLINT
-         + kEcma262UnCanonicalizeMultiStrings1Size *
-               sizeof(MultiCharacterSpecialCase<2>)  // NOLINT
-         + kEcma262UnCanonicalizeMultiStrings5Size *
-               sizeof(MultiCharacterSpecialCase<2>)  // NOLINT
-         + kEcma262UnCanonicalizeMultiStrings7Size *
-               sizeof(MultiCharacterSpecialCase<2>)  // NOLINT
-         + kCanonicalizationRangeMultiStrings0Size *
-               sizeof(MultiCharacterSpecialCase<1>)  // NOLINT
-         + kCanonicalizationRangeMultiStrings1Size *
-               sizeof(MultiCharacterSpecialCase<1>)  // NOLINT
-         + kCanonicalizationRangeMultiStrings7Size *
-               sizeof(MultiCharacterSpecialCase<1>);  // NOLINT
+  return kUppercaseTable0Size * sizeof(int32_t) +
+         kUppercaseTable1Size * sizeof(int32_t) +
+         kUppercaseTable5Size * sizeof(int32_t) +
+         kUppercaseTable7Size * sizeof(int32_t) +
+         kLetterTable0Size * sizeof(int32_t) +
+         kLetterTable1Size * sizeof(int32_t) +
+         kLetterTable2Size * sizeof(int32_t) +
+         kLetterTable3Size * sizeof(int32_t) +
+         kLetterTable4Size * sizeof(int32_t) +
+         kLetterTable5Size * sizeof(int32_t) +
+         kLetterTable6Size * sizeof(int32_t) +
+         kLetterTable7Size * sizeof(int32_t) +
+         kID_StartTable0Size * sizeof(int32_t) +
+         kID_StartTable1Size * sizeof(int32_t) +
+         kID_StartTable2Size * sizeof(int32_t) +
+         kID_StartTable3Size * sizeof(int32_t) +
+         kID_StartTable4Size * sizeof(int32_t) +
+         kID_StartTable5Size * sizeof(int32_t) +
+         kID_StartTable6Size * sizeof(int32_t) +
+         kID_StartTable7Size * sizeof(int32_t) +
+         kID_ContinueTable0Size * sizeof(int32_t) +
+         kID_ContinueTable1Size * sizeof(int32_t) +
+         kID_ContinueTable5Size * sizeof(int32_t) +
+         kID_ContinueTable7Size * sizeof(int32_t) +
+         kWhiteSpaceTable0Size * sizeof(int32_t) +
+         kWhiteSpaceTable1Size * sizeof(int32_t) +
+         kWhiteSpaceTable7Size * sizeof(int32_t) +
+         kToLowercaseMultiStrings0Size * sizeof(MultiCharacterSpecialCase<2>) +
+         kToLowercaseMultiStrings1Size * sizeof(MultiCharacterSpecialCase<1>) +
+         kToLowercaseMultiStrings5Size * sizeof(MultiCharacterSpecialCase<1>) +
+         kToLowercaseMultiStrings7Size * sizeof(MultiCharacterSpecialCase<1>) +
+         kToUppercaseMultiStrings0Size * sizeof(MultiCharacterSpecialCase<3>) +
+         kToUppercaseMultiStrings1Size * sizeof(MultiCharacterSpecialCase<1>) +
+         kToUppercaseMultiStrings5Size * sizeof(MultiCharacterSpecialCase<1>) +
+         kToUppercaseMultiStrings7Size * sizeof(MultiCharacterSpecialCase<3>) +
+         kEcma262CanonicalizeMultiStrings0Size *
+             sizeof(MultiCharacterSpecialCase<1>) +
+         kEcma262CanonicalizeMultiStrings1Size *
+             sizeof(MultiCharacterSpecialCase<1>) +
+         kEcma262CanonicalizeMultiStrings5Size *
+             sizeof(MultiCharacterSpecialCase<1>) +
+         kEcma262CanonicalizeMultiStrings7Size *
+             sizeof(MultiCharacterSpecialCase<1>) +
+         kEcma262UnCanonicalizeMultiStrings0Size *
+             sizeof(MultiCharacterSpecialCase<4>) +
+         kEcma262UnCanonicalizeMultiStrings1Size *
+             sizeof(MultiCharacterSpecialCase<2>) +
+         kEcma262UnCanonicalizeMultiStrings5Size *
+             sizeof(MultiCharacterSpecialCase<2>) +
+         kEcma262UnCanonicalizeMultiStrings7Size *
+             sizeof(MultiCharacterSpecialCase<2>) +
+         kCanonicalizationRangeMultiStrings0Size *
+             sizeof(MultiCharacterSpecialCase<1>) +
+         kCanonicalizationRangeMultiStrings1Size *
+             sizeof(MultiCharacterSpecialCase<1>) +
+         kCanonicalizationRangeMultiStrings7Size *
+             sizeof(MultiCharacterSpecialCase<1>);
 }
 #endif  // !V8_INTL_SUPPORT
 
diff --git a/chromium/v8/src/third_party/vtune/BUILD.gn b/chromium/v8/src/third_party/vtune/BUILD.gn
index f699ab147ef..e8582dbb793 100644
--- a/chromium/v8/src/third_party/vtune/BUILD.gn
+++ b/chromium/v8/src/third_party/vtune/BUILD.gn
@@ -22,9 +22,7 @@ static_library("v8_vtune") {
     "vtune-jit.h",
   ]
   configs += [ ":vtune_ittapi" ]
-  deps = [
-    "../../..:v8",
-  ]
+  deps = [ "../../..:v8" ]
 }
 
 static_library("v8_vtune_trace_mark") {
@@ -33,16 +31,13 @@ static_library("v8_vtune_trace_mark") {
     "vtuneapi.cc",
     "vtuneapi.h",
   ]
-  deps = [
-    ":ittnotify",
-  ]
+  deps = [ ":ittnotify" ]
 }
 
 static_library("ittnotify") {
   sources = [
     "//third_party/ittapi/include/ittnotify.h",
     "//third_party/ittapi/include/legacy/ittnotify.h",
-    "//third_party/ittapi/src/ittnotify/disable-warnings.h",
     "//third_party/ittapi/src/ittnotify/ittnotify_config.h",
     "//third_party/ittapi/src/ittnotify/ittnotify_static.c",
     "//third_party/ittapi/src/ittnotify/ittnotify_static.h",
diff --git a/chromium/v8/src/torque/class-debug-reader-generator.cc b/chromium/v8/src/torque/class-debug-reader-generator.cc
index 19ac671bd79..5f45ea3adef 100644
--- a/chromium/v8/src/torque/class-debug-reader-generator.cc
+++ b/chromium/v8/src/torque/class-debug-reader-generator.cc
@@ -285,6 +285,11 @@ void GenerateFieldValueAccessor(const Field& field,
   cc_contents << "  d::MemoryAccessResult validity = accessor("
               << address_getter << "()" << index_offset
               << ", reinterpret_cast<uint8_t*>(&value), sizeof(value));\n";
+#ifdef V8_MAP_PACKING
+  if (field_getter == "GetMapValue") {
+    cc_contents << "  value = i::MapWord::Unpack(value);\n";
+  }
+#endif
   cc_contents << "  return {validity, "
               << (debug_field_type.IsTagged()
                       ? "EnsureDecompressed(value, address_)"
diff --git a/chromium/v8/src/torque/constants.h b/chromium/v8/src/torque/constants.h
index 2a4e6fcb5b3..bb0ae2b69ef 100644
--- a/chromium/v8/src/torque/constants.h
+++ b/chromium/v8/src/torque/constants.h
@@ -107,15 +107,15 @@ static const char* const ANNOTATION_EXPORT = "@export";
 static const char* const ANNOTATION_DO_NOT_GENERATE_CAST = "@doNotGenerateCast";
 static const char* const ANNOTATION_USE_PARENT_TYPE_CHECKER =
     "@useParentTypeChecker";
-// Generate C++ accessors with relaxed write semantics.
-// Weak<T> and MaybeObject fields always use relaxed write.
-static const char* const ANNOTATION_RELAXED_WRITE = "@relaxedWrite";
-// Generate C++ accessors with relaxed read semantics.
-static const char* const ANNOTATION_RELAXED_READ = "@relaxedRead";
-// Generate C++ accessors with release write semantics.
-static const char* const ANNOTATION_RELEASE_WRITE = "@releaseWrite";
-// Generate C++ accessors with acquire read semantics.
-static const char* const ANNOTATION_ACQUIRE_READ = "@acquireRead";
+// Generate C++ accessors with relaxed store semantics.
+// Weak<T> and MaybeObject fields always use relaxed store.
+static const char* const ANNOTATION_CPP_RELAXED_STORE = "@cppRelaxedStore";
+// Generate C++ accessors with relaxed load semantics.
+static const char* const ANNOTATION_CPP_RELAXED_LOAD = "@cppRelaxedLoad";
+// Generate C++ accessors with release store semantics.
+static const char* const ANNOTATION_CPP_RELEASE_STORE = "@cppReleaseStore";
+// Generate C++ accessors with acquire load semantics.
+static const char* const ANNOTATION_CPP_ACQUIRE_LOAD = "@cppAcquireLoad";
 
 inline bool IsConstexprName(const std::string& name) {
   return name.substr(0, std::strlen(CONSTEXPR_TYPE_PREFIX)) ==
diff --git a/chromium/v8/src/torque/global-context.h b/chromium/v8/src/torque/global-context.h
index 403502b67bf..754d16e4a03 100644
--- a/chromium/v8/src/torque/global-context.h
+++ b/chromium/v8/src/torque/global-context.h
@@ -79,6 +79,8 @@ class GlobalContext : public ContextualClass<GlobalContext> {
     std::stringstream class_definition_inline_headerfile;
 
     std::stringstream class_definition_ccfile;
+
+    std::set<SourceId> required_builtin_includes;
   };
   static PerFileStreams& GeneratedPerFile(SourceId file) {
     PerFileStreams& result = Get().generated_per_file_[file];
diff --git a/chromium/v8/src/torque/implementation-visitor.cc b/chromium/v8/src/torque/implementation-visitor.cc
index a2cf0fee866..b35a45d7b65 100644
--- a/chromium/v8/src/torque/implementation-visitor.cc
+++ b/chromium/v8/src/torque/implementation-visitor.cc
@@ -11,12 +11,14 @@
 #include "src/base/optional.h"
 #include "src/common/globals.h"
 #include "src/torque/cc-generator.h"
+#include "src/torque/cfg.h"
 #include "src/torque/constants.h"
 #include "src/torque/csa-generator.h"
 #include "src/torque/declaration-visitor.h"
 #include "src/torque/global-context.h"
 #include "src/torque/parameter-difference.h"
 #include "src/torque/server-data.h"
+#include "src/torque/source-positions.h"
 #include "src/torque/type-inference.h"
 #include "src/torque/type-visitor.h"
 #include "src/torque/types.h"
@@ -26,6 +28,10 @@ namespace v8 {
 namespace internal {
 namespace torque {
 
+namespace {
+const char* BuiltinIncludesMarker = "// __BUILTIN_INCLUDES_MARKER__\n";
+}  // namespace
+
 VisitResult ImplementationVisitor::Visit(Expression* expr) {
   CurrentSourcePosition::Scope scope(expr->pos);
   switch (expr->kind) {
@@ -76,11 +82,17 @@ void ImplementationVisitor::BeginGeneratedFiles() {
         out << "#include " << StringLiteralQuote(include_path) << "\n";
       }
 
-      for (SourceId file : SourceFileMap::AllSources()) {
-        out << "#include \"torque-generated/" +
-                   SourceFileMap::PathFromV8RootWithoutExtension(file) +
-                   "-tq-csa.h\"\n";
-      }
+      out << "// Required Builtins:\n";
+      out << "#include \"torque-generated/" +
+                 SourceFileMap::PathFromV8RootWithoutExtension(file) +
+                 "-tq-csa.h\"\n";
+      // Now that required include files are collected while generting the file,
+      // we only know the full set at the end. Insert a marker here that is
+      // replaced with the list of includes at the very end.
+      // TODO(nicohartmann@): This is not the most beautiful way to do this,
+      // replace once the cpp file builder is available, where this can be
+      // handled easily.
+      out << BuiltinIncludesMarker;
       out << "\n";
 
       out << "namespace v8 {\n"
@@ -658,8 +670,8 @@ void ImplementationVisitor::Visit(Builtin* builtin) {
   } else {
     DCHECK(builtin->IsStub());
 
-    bool has_context_parameter = signature.HasContextParameter();
     for (size_t i = 0; i < signature.parameter_names.size(); ++i) {
+      const std::string& parameter_name = signature.parameter_names[i]->value;
       const Type* type = signature.types()[i];
       const bool mark_as_used = signature.implicit_count > i;
       std::string var = AddParameter(i, builtin, &parameters, &parameter_types,
@@ -667,14 +679,8 @@ void ImplementationVisitor::Visit(Builtin* builtin) {
       csa_ccfile() << "  " << type->GetGeneratedTypeName() << " " << var
                    << " = "
                    << "UncheckedParameter<" << type->GetGeneratedTNodeTypeName()
-                   << ">(";
-      if (i == 0 && has_context_parameter) {
-        csa_ccfile() << "Descriptor::kContext";
-      } else {
-        csa_ccfile() << "Descriptor::ParameterIndex<"
-                     << (has_context_parameter ? i - 1 : i) << ">()";
-      }
-      csa_ccfile() << ");\n";
+                   << ">(Descriptor::k" << CamelifyString(parameter_name)
+                   << ");\n";
       csa_ccfile() << "  USE(" << var << ");\n";
     }
   }
@@ -1743,7 +1749,23 @@ void ImplementationVisitor::GenerateImplementation(const std::string& dir) {
     GlobalContext::PerFileStreams& streams =
         GlobalContext::GeneratedPerFile(file);
 
-    WriteFile(base_filename + "-tq-csa.cc", streams.csa_ccfile.str());
+    std::string csa_cc = streams.csa_ccfile.str();
+    // Insert missing builtin includes where the marker is.
+    {
+      auto pos = csa_cc.find(BuiltinIncludesMarker);
+      CHECK_NE(pos, std::string::npos);
+      std::string includes;
+      for (const SourceId& include : streams.required_builtin_includes) {
+        std::string include_file =
+            SourceFileMap::PathFromV8RootWithoutExtension(include);
+        includes += "#include \"torque-generated/";
+        includes += include_file;
+        includes += "-tq-csa.h\"\n";
+      }
+      csa_cc.replace(pos, strlen(BuiltinIncludesMarker), std::move(includes));
+    }
+
+    WriteFile(base_filename + "-tq-csa.cc", std::move(csa_cc));
     WriteFile(base_filename + "-tq-csa.h", streams.csa_headerfile.str());
     WriteFile(base_filename + "-tq.inc",
               streams.class_definition_headerfile.str());
@@ -2368,6 +2390,10 @@ LocationReference ImplementationVisitor::GetLocationReference(
     }
   }
   Value* value = Declarations::LookupValue(name);
+  CHECK(value->Position().source.IsValid());
+  if (auto stream = CurrentFileStreams::Get()) {
+    stream->required_builtin_includes.insert(value->Position().source);
+  }
   if (GlobalContext::collect_language_server_data()) {
     LanguageServerData::AddDefinition(expr->name->pos, value->name()->pos);
   }
@@ -2623,6 +2649,11 @@ VisitResult ImplementationVisitor::GenerateCall(
     Callable* callable, base::Optional<LocationReference> this_reference,
     Arguments arguments, const TypeVector& specialization_types,
     bool is_tailcall) {
+  CHECK(callable->Position().source.IsValid());
+  if (auto stream = CurrentFileStreams::Get()) {
+    stream->required_builtin_includes.insert(callable->Position().source);
+  }
+
   const Type* return_type = callable->signature().return_type;
 
   if (is_tailcall) {
@@ -3128,8 +3159,7 @@ VisitResult ImplementationVisitor::Visit(CallMethodExpression* expr) {
   TypeVector argument_types = arguments.parameters.ComputeTypeVector();
   DCHECK_EQ(expr->method->namespace_qualification.size(), 0);
   QualifiedName qualified_name = QualifiedName(method_name);
-  Callable* callable = nullptr;
-  callable = LookupMethod(method_name, target_type, arguments, {});
+  Callable* callable = LookupMethod(method_name, target_type, arguments, {});
   if (GlobalContext::collect_language_server_data()) {
     LanguageServerData::AddDefinition(expr->method->name->pos,
                                       callable->IdentifierPosition());
@@ -3437,40 +3467,40 @@ void ImplementationVisitor::GenerateBuiltinDefinitionsAndInterfaceDescriptors(
         std::string descriptor_name = builtin->ExternalName() + "Descriptor";
         bool has_context_parameter = builtin->signature().HasContextParameter();
         size_t kFirstNonContextParameter = has_context_parameter ? 1 : 0;
-        size_t parameter_count =
-            builtin->parameter_names().size() - kFirstNonContextParameter;
         TypeVector return_types = LowerType(builtin->signature().return_type);
 
-        interface_descriptors
-            << "class " << descriptor_name
-            << " : public TorqueInterfaceDescriptor<" << return_types.size()
-            << ", " << parameter_count << ", "
-            << (has_context_parameter ? "true" : "false") << "> {\n";
-        interface_descriptors << "  DECLARE_DESCRIPTOR_WITH_BASE("
-                              << descriptor_name
-                              << ", TorqueInterfaceDescriptor)\n";
-
-        interface_descriptors
-            << "  std::vector<MachineType> ReturnType() override {\n";
-        interface_descriptors << "    return {{";
+        interface_descriptors << "class " << descriptor_name
+                              << " : public StaticCallInterfaceDescriptor<"
+                              << descriptor_name << "> {\n";
+
+        interface_descriptors << " public:\n";
+
+        if (has_context_parameter) {
+          interface_descriptors << "  DEFINE_RESULT_AND_PARAMETERS(";
+        } else {
+          interface_descriptors << "  DEFINE_RESULT_AND_PARAMETERS_NO_CONTEXT(";
+        }
+        interface_descriptors << return_types.size();
+        for (size_t i = kFirstNonContextParameter;
+             i < builtin->parameter_names().size(); ++i) {
+          Identifier* parameter = builtin->parameter_names()[i];
+          interface_descriptors << ", k" << CamelifyString(parameter->value);
+        }
+        interface_descriptors << ")\n";
+
+        interface_descriptors << "  DEFINE_RESULT_AND_PARAMETER_TYPES(";
         PrintCommaSeparatedList(interface_descriptors, return_types,
                                 MachineTypeString);
-        interface_descriptors << "}};\n";
-        interface_descriptors << "  }\n";
-
-        interface_descriptors << "  std::array<MachineType, " << parameter_count
-                              << "> ParameterTypes() override {\n";
-        interface_descriptors << "    return {";
         for (size_t i = kFirstNonContextParameter;
              i < builtin->parameter_names().size(); ++i) {
-          bool last = i + 1 == builtin->parameter_names().size();
           const Type* type = builtin->signature().parameter_types.types[i];
-          interface_descriptors << MachineTypeString(type)
-                                << (last ? "" : ", ");
+          interface_descriptors << ", " << MachineTypeString(type);
         }
-        interface_descriptors << "};\n";
+        interface_descriptors << ")\n";
+
+        interface_descriptors << "  DECLARE_DEFAULT_DESCRIPTOR("
+                              << descriptor_name << ")\n";
 
-        interface_descriptors << "  }\n";
         interface_descriptors << "};\n\n";
       } else {
         builtin_definitions << "TFJ(" << builtin->ExternalName();
@@ -4221,15 +4251,47 @@ void CppClassGenerator::GenerateFieldAccessors(
   }
 
   hdr_ << "  inline " << type_name << " " << name << "("
-       << (indexed ? "int i" : "") << ") const;\n";
+       << (indexed ? "int i" : "");
+  switch (class_field.read_synchronization) {
+    case FieldSynchronization::kNone:
+      break;
+    case FieldSynchronization::kRelaxed:
+      hdr_ << (indexed ? ", RelaxedLoadTag" : "RelaxedLoadTag");
+      break;
+    case FieldSynchronization::kAcquireRelease:
+      hdr_ << (indexed ? ", AcquireLoadTag" : "AcquireLoadTag");
+      break;
+  }
+  hdr_ << ") const;\n";
   if (can_contain_heap_objects) {
     hdr_ << "  inline " << type_name << " " << name
-         << "(PtrComprCageBase cage_base" << (indexed ? ", int i" : "")
-         << ") const;\n";
+         << "(PtrComprCageBase cage_base" << (indexed ? ", int i" : "");
+    switch (class_field.read_synchronization) {
+      case FieldSynchronization::kNone:
+        break;
+      case FieldSynchronization::kRelaxed:
+        hdr_ << ", RelaxedLoadTag";
+        break;
+      case FieldSynchronization::kAcquireRelease:
+        hdr_ << ", AcquireLoadTag";
+        break;
+    }
+
+    hdr_ << ") const;\n";
   }
   hdr_ << "  inline void set_" << name << "(" << (indexed ? "int i, " : "")
-       << type_name << " value"
-       << (can_contain_heap_objects
+       << type_name << " value";
+  switch (class_field.write_synchronization) {
+    case FieldSynchronization::kNone:
+      break;
+    case FieldSynchronization::kRelaxed:
+      hdr_ << ", RelaxedStoreTag";
+      break;
+    case FieldSynchronization::kAcquireRelease:
+      hdr_ << ", ReleaseStoreTag";
+      break;
+  }
+  hdr_ << (can_contain_heap_objects
                ? ", WriteBarrierMode mode = UPDATE_WRITE_BARRIER"
                : "")
        << ");\n\n";
@@ -4239,10 +4301,32 @@ void CppClassGenerator::GenerateFieldAccessors(
   if (can_contain_heap_objects) {
     inl_ << "template <class D, class P>\n";
     inl_ << type_name << " " << gen_name_ << "<D, P>::" << name << "("
-         << (indexed ? "int i" : "") << ") const {\n";
+         << (indexed ? "int i" : "");
+    switch (class_field.read_synchronization) {
+      case FieldSynchronization::kNone:
+        break;
+      case FieldSynchronization::kRelaxed:
+        inl_ << (indexed ? ", RelaxedLoadTag" : "RelaxedLoadTag");
+        break;
+      case FieldSynchronization::kAcquireRelease:
+        inl_ << (indexed ? ", AcquireLoadTag" : "AcquireLoadTag");
+        break;
+    }
+    inl_ << ") const {\n";
     inl_ << "  PtrComprCageBase cage_base = GetPtrComprCageBase(*this);\n";
     inl_ << "  return " << gen_name_ << "::" << name << "(cage_base"
-         << (indexed ? ", i" : "") << ");\n";
+         << (indexed ? ", i" : "");
+    switch (class_field.read_synchronization) {
+      case FieldSynchronization::kNone:
+        break;
+      case FieldSynchronization::kRelaxed:
+        inl_ << ", kRelaxedLoad";
+        break;
+      case FieldSynchronization::kAcquireRelease:
+        inl_ << ", kAcquireLoad";
+        break;
+    }
+    inl_ << ");\n";
     inl_ << "}\n";
   }
 
@@ -4252,6 +4336,18 @@ void CppClassGenerator::GenerateFieldAccessors(
   if (can_contain_heap_objects) inl_ << "PtrComprCageBase cage_base";
   if (can_contain_heap_objects && indexed) inl_ << ", ";
   if (indexed) inl_ << "int i";
+  switch (class_field.read_synchronization) {
+    case FieldSynchronization::kNone:
+      break;
+    case FieldSynchronization::kRelaxed:
+      inl_ << ((can_contain_heap_objects || indexed) ? ", RelaxedLoadTag"
+                                                     : "RelaxedLoadTag");
+      break;
+    case FieldSynchronization::kAcquireRelease:
+      inl_ << ((can_contain_heap_objects || indexed) ? ", AcquireLoadTag"
+                                                     : "AcquireLoadTag");
+      break;
+  }
   inl_ << ") const {\n";
 
   inl_ << "  " << type_name << " value;\n";
@@ -4266,6 +4362,16 @@ void CppClassGenerator::GenerateFieldAccessors(
     inl_ << "int i, ";
   }
   inl_ << type_name << " value";
+  switch (class_field.write_synchronization) {
+    case FieldSynchronization::kNone:
+      break;
+    case FieldSynchronization::kRelaxed:
+      inl_ << ", RelaxedStoreTag";
+      break;
+    case FieldSynchronization::kAcquireRelease:
+      inl_ << ", ReleaseStoreTag";
+      break;
+  }
   if (can_contain_heap_objects) {
     inl_ << ", WriteBarrierMode mode";
   }
@@ -4339,10 +4445,10 @@ void CppClassGenerator::EmitLoadFieldStatement(
   if (!field_type->IsSubtypeOf(TypeOracle::GetTaggedType())) {
     if (class_field.read_synchronization ==
         FieldSynchronization::kAcquireRelease) {
-      ReportError("Torque doesn't support @acquireRead on untagged data");
+      ReportError("Torque doesn't support @cppAcquireRead on untagged data");
     } else if (class_field.read_synchronization ==
                FieldSynchronization::kRelaxed) {
-      ReportError("Torque doesn't support @relaxedRead on untagged data");
+      ReportError("Torque doesn't support @cppRelaxedRead on untagged data");
     }
     inl_ << "this->template ReadField<" << type_name << ">(" << offset
          << ");\n";
@@ -4636,11 +4742,33 @@ void GeneratePrintDefinitionsForClass(std::ostream& impl, const ClassType* type,
             // TODO(turbofan): Print struct fields too.
             impl << "\" <struct field printing still unimplemented>\";\n";
           } else {
-            impl << "this->" << f.name_and_type.name << "();\n";
+            impl << "this->" << f.name_and_type.name;
+            switch (f.read_synchronization) {
+              case FieldSynchronization::kNone:
+                impl << "();\n";
+                break;
+              case FieldSynchronization::kRelaxed:
+                impl << "(kRelaxedLoad);\n";
+                break;
+              case FieldSynchronization::kAcquireRelease:
+                impl << "(kAcquireLoad);\n";
+                break;
+            }
           }
         } else {
           impl << "  os << \"\\n - " << f.name_and_type.name << ": \" << "
-               << "Brief(this->" << f.name_and_type.name << "());\n";
+               << "Brief(this->" << f.name_and_type.name;
+          switch (f.read_synchronization) {
+            case FieldSynchronization::kNone:
+              impl << "());\n";
+              break;
+            case FieldSynchronization::kRelaxed:
+              impl << "(kRelaxedLoad));\n";
+              break;
+            case FieldSynchronization::kAcquireRelease:
+              impl << "(kAcquireLoad));\n";
+              break;
+          }
         }
       }
     }
@@ -4864,7 +4992,7 @@ namespace {
 void GenerateFieldValueVerifier(const std::string& class_name, bool indexed,
                                 std::string offset, const Field& leaf_field,
                                 std::string indexed_field_size,
-                                std::ostream& cc_contents) {
+                                std::ostream& cc_contents, bool is_map) {
   const Type* field_type = leaf_field.name_and_type.type;
 
   bool maybe_object =
@@ -4879,8 +5007,12 @@ void GenerateFieldValueVerifier(const std::string& class_name, bool indexed,
   const std::string value = leaf_field.name_and_type.name + "__value";
 
   // Read the field.
-  cc_contents << "    " << object_type << " " << value << " = TaggedField<"
-              << object_type << ">::load(o, " << offset << ");\n";
+  if (is_map) {
+    cc_contents << "    " << object_type << " " << value << " = o.map();\n";
+  } else {
+    cc_contents << "    " << object_type << " " << value << " = TaggedField<"
+                << object_type << ">::load(o, " << offset << ");\n";
+  }
 
   // Call VerifyPointer or VerifyMaybeObjectPointer on it.
   cc_contents << "    " << object_type << "::" << verify_fn << "(isolate, "
@@ -4947,13 +5079,13 @@ void GenerateClassFieldVerifier(const std::string& class_name,
             class_name, f.index.has_value(),
             field_start_offset + " + " + std::to_string(*struct_field.offset),
             struct_field, std::to_string((*struct_type)->PackedSize()),
-            cc_contents);
+            cc_contents, f.name_and_type.name == "map");
       }
     }
   } else {
     GenerateFieldValueVerifier(class_name, f.index.has_value(),
                                field_start_offset, f, "kTaggedSize",
-                               cc_contents);
+                               cc_contents, f.name_and_type.name == "map");
   }
 
   cc_contents << "  }\n";
diff --git a/chromium/v8/src/torque/torque-parser.cc b/chromium/v8/src/torque/torque-parser.cc
index cab0182677a..c74ef024978 100644
--- a/chromium/v8/src/torque/torque-parser.cc
+++ b/chromium/v8/src/torque/torque-parser.cc
@@ -1954,22 +1954,23 @@ base::Optional<ParseResult> MakeAnnotation(ParseResultIterator* child_results) {
 }
 
 base::Optional<ParseResult> MakeClassField(ParseResultIterator* child_results) {
-  AnnotationSet annotations(child_results,
-                            {ANNOTATION_NO_VERIFIER, ANNOTATION_RELAXED_WRITE,
-                             ANNOTATION_RELAXED_READ, ANNOTATION_RELEASE_WRITE,
-                             ANNOTATION_ACQUIRE_READ},
-                            {ANNOTATION_IF, ANNOTATION_IFNOT});
+  AnnotationSet annotations(
+      child_results,
+      {ANNOTATION_NO_VERIFIER, ANNOTATION_CPP_RELAXED_STORE,
+       ANNOTATION_CPP_RELAXED_LOAD, ANNOTATION_CPP_RELEASE_STORE,
+       ANNOTATION_CPP_ACQUIRE_LOAD},
+      {ANNOTATION_IF, ANNOTATION_IFNOT});
   bool generate_verify = !annotations.Contains(ANNOTATION_NO_VERIFIER);
   FieldSynchronization write_synchronization = FieldSynchronization::kNone;
-  if (annotations.Contains(ANNOTATION_RELEASE_WRITE)) {
+  if (annotations.Contains(ANNOTATION_CPP_RELEASE_STORE)) {
     write_synchronization = FieldSynchronization::kAcquireRelease;
-  } else if (annotations.Contains(ANNOTATION_RELAXED_WRITE)) {
+  } else if (annotations.Contains(ANNOTATION_CPP_RELAXED_STORE)) {
     write_synchronization = FieldSynchronization::kRelaxed;
   }
   FieldSynchronization read_synchronization = FieldSynchronization::kNone;
-  if (annotations.Contains(ANNOTATION_ACQUIRE_READ)) {
+  if (annotations.Contains(ANNOTATION_CPP_ACQUIRE_LOAD)) {
     read_synchronization = FieldSynchronization::kAcquireRelease;
-  } else if (annotations.Contains(ANNOTATION_RELAXED_READ)) {
+  } else if (annotations.Contains(ANNOTATION_CPP_RELAXED_LOAD)) {
     read_synchronization = FieldSynchronization::kRelaxed;
   }
   std::vector<ConditionalAnnotation> conditions;
diff --git a/chromium/v8/src/torque/torque.cc b/chromium/v8/src/torque/torque.cc
index 4e71c430140..ca16ce4ca6c 100644
--- a/chromium/v8/src/torque/torque.cc
+++ b/chromium/v8/src/torque/torque.cc
@@ -33,7 +33,12 @@ int WrappedMain(int argc, const char** argv) {
     } else if (argument == "-v8-root") {
       options.v8_root = std::string(argv[++i]);
     } else if (argument == "-m32") {
+#ifdef V8_COMPRESS_POINTERS
+      std::cerr << "Pointer compression is incompatible with -m32.\n";
+      base::OS::Abort();
+#else
       options.force_32bit_output = true;
+#endif
     } else if (argument == "-annotate-ir") {
       options.annotate_ir = true;
     } else {
diff --git a/chromium/v8/src/tracing/trace-event.cc b/chromium/v8/src/tracing/trace-event.cc
index 8e69fe55205..7f1f96adc79 100644
--- a/chromium/v8/src/tracing/trace-event.cc
+++ b/chromium/v8/src/tracing/trace-event.cc
@@ -20,6 +20,8 @@ v8::TracingController* TraceEventHelper::GetTracingController() {
   return v8::internal::V8::GetCurrentPlatform()->GetTracingController();
 }
 
+#ifdef V8_RUNTIME_CALL_STATS
+
 void CallStatsScopedTracer::AddEndTraceEvent() {
   if (!has_parent_scope_ && p_data_->isolate) {
     auto value = v8::tracing::TracedValue::Create();
@@ -52,6 +54,8 @@ void CallStatsScopedTracer::Initialize(v8::internal::Isolate* isolate,
       v8::internal::tracing::kGlobalScope, v8::internal::tracing::kNoId,
       TRACE_EVENT_FLAG_NONE, v8::internal::tracing::kNoId);
 }
+
+#endif  // defined(V8_RUNTIME_CALL_STATS)
 #endif  // !defined(V8_USE_PERFETTO)
 
 }  // namespace tracing
diff --git a/chromium/v8/src/tracing/trace-event.h b/chromium/v8/src/tracing/trace-event.h
index b5a16c85907..36c9cdcadf5 100644
--- a/chromium/v8/src/tracing/trace-event.h
+++ b/chromium/v8/src/tracing/trace-event.h
@@ -279,6 +279,7 @@ enum CategoryGroupEnabledFlags {
 #define TRACE_EVENT_CALL_STATS_SCOPED(isolate, category_group, name) \
   INTERNAL_TRACE_EVENT_CALL_STATS_SCOPED(isolate, category_group, name)
 
+#ifdef V8_RUNTIME_CALL_STATS
 #define INTERNAL_TRACE_EVENT_CALL_STATS_SCOPED(isolate, category_group, name)  \
   INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category_group);                      \
   v8::internal::tracing::CallStatsScopedTracer INTERNAL_TRACE_EVENT_UID(       \
@@ -288,6 +289,9 @@ enum CategoryGroupEnabledFlags {
         .Initialize(isolate, INTERNAL_TRACE_EVENT_UID(category_group_enabled), \
                     name);                                                     \
   }
+#else  // V8_RUNTIME_CALL_STATS
+#define INTERNAL_TRACE_EVENT_CALL_STATS_SCOPED(isolate, category_group, name)
+#endif  // V8_RUNTIME_CALL_STATS
 
 namespace v8 {
 namespace internal {
@@ -588,6 +592,7 @@ class ScopedTracer {
   Data data_;
 };
 
+#ifdef V8_RUNTIME_CALL_STATS
 // Do not use directly.
 class CallStatsScopedTracer {
  public:
@@ -612,6 +617,7 @@ class CallStatsScopedTracer {
   Data* p_data_;
   Data data_;
 };
+#endif  // defined(V8_RUNTIME_CALL_STATS)
 
 }  // namespace tracing
 }  // namespace internal
@@ -619,6 +625,8 @@ class CallStatsScopedTracer {
 
 #else  // defined(V8_USE_PERFETTO)
 
+#ifdef V8_RUNTIME_CALL_STATS
+
 #define TRACE_EVENT_CALL_STATS_SCOPED(isolate, category, name)             \
   struct PERFETTO_UID(ScopedEvent) {                                       \
     struct ScopedStats {                                                   \
@@ -650,6 +658,7 @@ class CallStatsScopedTracer {
     { isolate, 0 }                                                         \
   }
 
+#endif  // defined(V8_RUNTIME_CALL_STATS)
 #endif  // defined(V8_USE_PERFETTO)
 
 #endif  // V8_TRACING_TRACE_EVENT_H_
diff --git a/chromium/v8/src/trap-handler/DEPS b/chromium/v8/src/trap-handler/DEPS
index 061634d51b8..dc6d27e1554 100644
--- a/chromium/v8/src/trap-handler/DEPS
+++ b/chromium/v8/src/trap-handler/DEPS
@@ -6,19 +6,8 @@ include_rules = [
   "-src",
   "-include",
   "+src/trap-handler",
+  # Use the IMMEDIATE_CRASH() macro for crashing non-recoverably on check failure.
+  "+src/base/immediate-crash.h",
+  # Allow include/v8config.h for V8_OS_* macros.
+  "+include/v8config.h",
 ]
-
-specific_include_rules = {
-  "trap-handler.h": [
-    "+src/base/build_config.h",
-    "+src/common/globals.h",
-    "+src/flags/flags.h",
-  ],
-  "handler-inside-posix.h": [
-    # To access V8_OS_LINUX. This file is already included in build_config.h.
-    "+include/v8config.h",
-  ],
-  "handler-inside-win.h": [
-    "+src/base/macros.h",
-  ]
-}
diff --git a/chromium/v8/src/trap-handler/handler-inside-posix.h b/chromium/v8/src/trap-handler/handler-inside-posix.h
index 49fe23a7128..27e46773bbd 100644
--- a/chromium/v8/src/trap-handler/handler-inside-posix.h
+++ b/chromium/v8/src/trap-handler/handler-inside-posix.h
@@ -6,6 +6,7 @@
 #define V8_TRAP_HANDLER_HANDLER_INSIDE_POSIX_H_
 
 #include <signal.h>
+
 #include "include/v8config.h"
 
 namespace v8 {
diff --git a/chromium/v8/src/trap-handler/handler-inside-win.h b/chromium/v8/src/trap-handler/handler-inside-win.h
index 6db28149e7d..9b9b0605178 100644
--- a/chromium/v8/src/trap-handler/handler-inside-win.h
+++ b/chromium/v8/src/trap-handler/handler-inside-win.h
@@ -7,7 +7,7 @@
 
 #include <windows.h>
 
-#include "src/base/macros.h"
+#include "src/trap-handler/trap-handler.h"  // For TH_DISABLE_ASAN.
 
 namespace v8 {
 namespace internal {
@@ -18,7 +18,7 @@ LONG WINAPI HandleWasmTrap(EXCEPTION_POINTERS* exception);
 // On Windows, asan installs its own exception handler which maps shadow
 // memory. Since our exception handler may be executed before the asan exception
 // handler, we have to make sure that asan shadow memory is not accessed here.
-DISABLE_ASAN bool TryHandleWasmTrap(EXCEPTION_POINTERS* exception);
+TH_DISABLE_ASAN bool TryHandleWasmTrap(EXCEPTION_POINTERS* exception);
 
 }  // namespace trap_handler
 }  // namespace internal
diff --git a/chromium/v8/src/trap-handler/handler-inside.cc b/chromium/v8/src/trap-handler/handler-inside.cc
index 81e37c205af..31d7f24491a 100644
--- a/chromium/v8/src/trap-handler/handler-inside.cc
+++ b/chromium/v8/src/trap-handler/handler-inside.cc
@@ -50,11 +50,14 @@ bool TryFindLandingPad(uintptr_t fault_addr, uintptr_t* landing_pad) {
     if (data == nullptr) {
       continue;
     }
-    const Address base = data->base;
+    const uintptr_t base = data->base;
 
     if (fault_addr >= base && fault_addr < base + data->size) {
       // Hurray, we found the code object. Check for protected addresses.
-      const ptrdiff_t offset = fault_addr - base;
+      const uint32_t offset = static_cast<uint32_t>(fault_addr - base);
+      // The offset must fit in 32 bit, see comment on
+      // ProtectedInstructionData::instr_offset.
+      TH_DCHECK(base + offset == fault_addr);
 
       for (unsigned i = 0; i < data->num_protected_instructions; ++i) {
         if (data->instructions[i].instr_offset == offset) {
diff --git a/chromium/v8/src/trap-handler/handler-outside-posix.cc b/chromium/v8/src/trap-handler/handler-outside-posix.cc
index 55bcc0075b3..004783b64f3 100644
--- a/chromium/v8/src/trap-handler/handler-outside-posix.cc
+++ b/chromium/v8/src/trap-handler/handler-outside-posix.cc
@@ -21,6 +21,8 @@
 
 #include <signal.h>
 
+#include <cstdio>
+
 #include "src/trap-handler/handler-inside-posix.h"
 #include "src/trap-handler/trap-handler-internal.h"
 
@@ -39,7 +41,7 @@ bool g_is_default_signal_handler_registered;
 }  // namespace
 
 bool RegisterDefaultTrapHandler() {
-  CHECK(!g_is_default_signal_handler_registered);
+  TH_CHECK(!g_is_default_signal_handler_registered);
 
   struct sigaction action;
   action.sa_sigaction = HandleSignal;
@@ -61,7 +63,7 @@ bool RegisterDefaultTrapHandler() {
     defined(THREAD_SANITIZER) || defined(LEAK_SANITIZER) ||    \
     defined(UNDEFINED_SANITIZER)
   struct sigaction installed_handler;
-  CHECK_EQ(sigaction(kOobSignal, NULL, &installed_handler), 0);
+  TH_CHECK(sigaction(kOobSignal, NULL, &installed_handler) == 0);
   // If the installed handler does not point to HandleSignal, then
   // allow_user_segv_handler is 0.
   if (installed_handler.sa_sigaction != HandleSignal) {
diff --git a/chromium/v8/src/trap-handler/handler-outside-win.cc b/chromium/v8/src/trap-handler/handler-outside-win.cc
index 09673c8cccf..307f919d789 100644
--- a/chromium/v8/src/trap-handler/handler-outside-win.cc
+++ b/chromium/v8/src/trap-handler/handler-outside-win.cc
@@ -40,7 +40,7 @@ void* g_registered_handler = nullptr;
 
 bool RegisterDefaultTrapHandler() {
   constexpr ULONG first = TRUE;
-  CHECK_NULL(g_registered_handler);
+  TH_CHECK(g_registered_handler == nullptr);
   g_registered_handler = AddVectoredExceptionHandler(first, HandleWasmTrap);
 
   return nullptr != g_registered_handler;
diff --git a/chromium/v8/src/trap-handler/handler-outside.cc b/chromium/v8/src/trap-handler/handler-outside.cc
index 62355a5b60f..2eabcca0f7e 100644
--- a/chromium/v8/src/trap-handler/handler-outside.cc
+++ b/chromium/v8/src/trap-handler/handler-outside.cc
@@ -66,7 +66,7 @@ bool IsDisjoint(const CodeProtectionInfo* a, const CodeProtectionInfo* b) {
 // registered.
 void VerifyCodeRangeIsDisjoint(const CodeProtectionInfo* code_info) {
   for (size_t i = 0; i < gNumCodeObjects; ++i) {
-    DCHECK(IsDisjoint(code_info, gCodeObjects[i].code_info));
+    TH_DCHECK(IsDisjoint(code_info, gCodeObjects[i].code_info));
   }
 }
 
@@ -79,11 +79,11 @@ void ValidateCodeObjects() {
 
     // Do some sanity checks on the protected instruction data
     for (unsigned i = 0; i < data->num_protected_instructions; ++i) {
-      DCHECK_GE(data->instructions[i].instr_offset, 0);
-      DCHECK_LT(data->instructions[i].instr_offset, data->size);
-      DCHECK_GE(data->instructions[i].landing_offset, 0);
-      DCHECK_LT(data->instructions[i].landing_offset, data->size);
-      DCHECK_GT(data->instructions[i].landing_offset,
+      TH_DCHECK(data->instructions[i].instr_offset >= 0);
+      TH_DCHECK(data->instructions[i].instr_offset < data->size);
+      TH_DCHECK(data->instructions[i].landing_offset >= 0);
+      TH_DCHECK(data->instructions[i].landing_offset < data->size);
+      TH_DCHECK(data->instructions[i].landing_offset >
                 data->instructions[i].instr_offset);
     }
   }
@@ -92,10 +92,10 @@ void ValidateCodeObjects() {
   size_t free_count = 0;
   for (size_t i = gNextCodeObject; i != gNumCodeObjects;
        i = gCodeObjects[i].next_free) {
-    DCHECK_LT(i, gNumCodeObjects);
+    TH_DCHECK(i < gNumCodeObjects);
     ++free_count;
     // This check will fail if we encounter a cycle.
-    DCHECK_LE(free_count, gNumCodeObjects);
+    TH_DCHECK(free_count <= gNumCodeObjects);
   }
 
   // Check that all free entries are reachable via the free list.
@@ -105,12 +105,12 @@ void ValidateCodeObjects() {
       ++free_count2;
     }
   }
-  DCHECK_EQ(free_count, free_count2);
+  TH_DCHECK(free_count == free_count2);
 }
 }  // namespace
 
 CodeProtectionInfo* CreateHandlerData(
-    Address base, size_t size, size_t num_protected_instructions,
+    uintptr_t base, size_t size, size_t num_protected_instructions,
     const ProtectedInstructionData* protected_instructions) {
   const size_t alloc_size = HandlerDataSize(num_protected_instructions);
   CodeProtectionInfo* data =
@@ -131,9 +131,8 @@ CodeProtectionInfo* CreateHandlerData(
 }
 
 int RegisterHandlerData(
-    Address base, size_t size, size_t num_protected_instructions,
+    uintptr_t base, size_t size, size_t num_protected_instructions,
     const ProtectedInstructionData* protected_instructions) {
-
   CodeProtectionInfo* data = CreateHandlerData(
       base, size, num_protected_instructions, protected_instructions);
 
@@ -188,7 +187,7 @@ int RegisterHandlerData(
     gNumCodeObjects = new_size;
   }
 
-  DCHECK(gCodeObjects[i].code_info == nullptr);
+  TH_DCHECK(gCodeObjects[i].code_info == nullptr);
 
   // Find out where the next entry should go.
   gNextCodeObject = gCodeObjects[i].next_free;
@@ -211,7 +210,7 @@ void ReleaseHandlerData(int index) {
   if (index == kInvalidIndex) {
     return;
   }
-  DCHECK_GE(index, 0);
+  TH_DCHECK(index >= 0);
 
   // Remove the data from the global list if it's there.
   CodeProtectionInfo* data = nullptr;
@@ -230,7 +229,7 @@ void ReleaseHandlerData(int index) {
   }
   // TODO(eholk): on debug builds, ensure there are no more copies in
   // the list.
-  DCHECK_NOT_NULL(data);  // make sure we're releasing legitimate handler data.
+  TH_DCHECK(data);  // make sure we're releasing legitimate handler data.
   free(data);
 }
 
@@ -259,9 +258,9 @@ bool EnableTrapHandler(bool use_v8_handler) {
   // trap handlers are disabled.
   bool can_enable =
       g_can_enable_trap_handler.exchange(false, std::memory_order_relaxed);
-  if (!can_enable) {
-    FATAL("EnableTrapHandler called twice, or after IsTrapHandlerEnabled");
-  }
+  // EnableTrapHandler called twice, or after IsTrapHandlerEnabled.
+  TH_CHECK(can_enable);
+
   if (!V8_TRAP_HANDLER_SUPPORTED) {
     return false;
   }
diff --git a/chromium/v8/src/trap-handler/handler-shared.cc b/chromium/v8/src/trap-handler/handler-shared.cc
index 0607d2ed547..977d28daee9 100644
--- a/chromium/v8/src/trap-handler/handler-shared.cc
+++ b/chromium/v8/src/trap-handler/handler-shared.cc
@@ -26,7 +26,7 @@ namespace trap_handler {
 // We declare this as int rather than bool as a workaround for a glibc bug, in
 // which the dynamic loader cannot handle executables whose TLS area is only
 // 1 byte in size; see https://sourceware.org/bugzilla/show_bug.cgi?id=14898.
-THREAD_LOCAL int g_thread_in_wasm_code;
+thread_local int g_thread_in_wasm_code;
 
 static_assert(sizeof(g_thread_in_wasm_code) > 1,
               "sizeof(thread_local_var) must be > 1, see "
diff --git a/chromium/v8/src/trap-handler/trap-handler-internal.h b/chromium/v8/src/trap-handler/trap-handler-internal.h
index 843cd34b704..71588ab8957 100644
--- a/chromium/v8/src/trap-handler/trap-handler-internal.h
+++ b/chromium/v8/src/trap-handler/trap-handler-internal.h
@@ -22,7 +22,7 @@ namespace trap_handler {
 // protected memory access instructions and an offset to a landing pad to handle
 // faults on that instruction.
 struct CodeProtectionInfo {
-  Address base;
+  uintptr_t base;
   size_t size;
   size_t num_protected_instructions;
   ProtectedInstructionData instructions[1];
diff --git a/chromium/v8/src/trap-handler/trap-handler.h b/chromium/v8/src/trap-handler/trap-handler.h
index fcdc256a38d..a27ea236e79 100644
--- a/chromium/v8/src/trap-handler/trap-handler.h
+++ b/chromium/v8/src/trap-handler/trap-handler.h
@@ -10,15 +10,13 @@
 
 #include <atomic>
 
-#include "src/base/build_config.h"
-#include "src/common/globals.h"
-#include "src/flags/flags.h"
+#include "include/v8config.h"
+#include "src/base/immediate-crash.h"
 
 namespace v8 {
 namespace internal {
 namespace trap_handler {
 
-// TODO(eholk): Support trap handlers on other platforms.
 #if V8_TARGET_ARCH_X64 && V8_OS_LINUX && !V8_OS_ANDROID
 #define V8_TRAP_HANDLER_SUPPORTED true
 #elif V8_TARGET_ARCH_X64 && V8_OS_WIN
@@ -33,6 +31,35 @@ namespace trap_handler {
 #define V8_TRAP_HANDLER_SUPPORTED false
 #endif
 
+// Setup for shared library export.
+#if defined(BUILDING_V8_SHARED) && defined(V8_OS_WIN)
+#define TH_EXPORT_PRIVATE __declspec(dllexport)
+#elif defined(BUILDING_V8_SHARED)
+#define TH_EXPORT_PRIVATE __attribute__((visibility("default")))
+#elif defined(USING_V8_SHARED) && defined(V8_OS_WIN)
+#define TH_EXPORT_PRIVATE __declspec(dllimport)
+#else
+#define TH_EXPORT_PRIVATE
+#endif
+
+#define TH_CHECK(condition) \
+  if (!(condition)) IMMEDIATE_CRASH();
+#ifdef DEBUG
+#define TH_DCHECK(condition) TH_CHECK(condition)
+#else
+#define TH_DCHECK(condition) void(0)
+#endif
+
+#if defined(__has_feature)
+#if __has_feature(address_sanitizer)
+#define TH_DISABLE_ASAN __attribute__((no_sanitize_address))
+#else
+#define TH_DISABLE_ASAN
+#endif
+#else
+#define TH_DISABLE_ASAN
+#endif
+
 struct ProtectedInstructionData {
   // The offset of this instruction from the start of its code object.
   // Wasm code never grows larger than 2GB, so uint32_t is sufficient.
@@ -50,23 +77,14 @@ const int kInvalidIndex = -1;
 ///
 /// This returns a number that can be used to identify the handler data to
 /// ReleaseHandlerData, or -1 on failure.
-int V8_EXPORT_PRIVATE RegisterHandlerData(
-    Address base, size_t size, size_t num_protected_instructions,
+int TH_EXPORT_PRIVATE RegisterHandlerData(
+    uintptr_t base, size_t size, size_t num_protected_instructions,
     const ProtectedInstructionData* protected_instructions);
 
 /// Removes the data from the master list and frees any memory, if necessary.
 /// TODO(mtrofin): We can switch to using size_t for index and not need
 /// kInvalidIndex.
-void V8_EXPORT_PRIVATE ReleaseHandlerData(int index);
-
-#if V8_OS_WIN
-#define THREAD_LOCAL __declspec(thread)
-#elif V8_OS_ANDROID
-// TODO(eholk): fix this before enabling for trap handlers for Android.
-#define THREAD_LOCAL
-#else
-#define THREAD_LOCAL __thread
-#endif
+void TH_EXPORT_PRIVATE ReleaseHandlerData(int index);
 
 // Initially false, set to true if when trap handlers are enabled. Never goes
 // back to false then.
@@ -83,10 +101,10 @@ extern std::atomic<bool> g_can_enable_trap_handler;
 //
 // use_v8_handler indicates that V8 should install its own handler
 // rather than relying on the embedder to do it.
-V8_EXPORT_PRIVATE bool EnableTrapHandler(bool use_v8_handler);
+TH_EXPORT_PRIVATE bool EnableTrapHandler(bool use_v8_handler);
 
 inline bool IsTrapHandlerEnabled() {
-  DCHECK_IMPLIES(g_is_trap_handler_enabled, V8_TRAP_HANDLER_SUPPORTED);
+  TH_DCHECK(!g_is_trap_handler_enabled || V8_TRAP_HANDLER_SUPPORTED);
   // Disallow enabling the trap handler after retrieving the current value.
   // Re-enabling them late can produce issues because code or objects might have
   // been generated under the assumption that trap handlers are disabled.
@@ -97,34 +115,40 @@ inline bool IsTrapHandlerEnabled() {
   return g_is_trap_handler_enabled;
 }
 
-extern THREAD_LOCAL int g_thread_in_wasm_code;
+#if defined(V8_OS_AIX)
+// `thread_local` does not link on AIX:
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100641
+extern __thread int g_thread_in_wasm_code;
+#else
+extern thread_local int g_thread_in_wasm_code;
+#endif
 
 // Return the address of the thread-local {g_thread_in_wasm_code} variable. This
 // pointer can be accessed and modified as long as the thread calling this
 // function exists. Only use if from the same thread do avoid race conditions.
-V8_NOINLINE V8_EXPORT_PRIVATE int* GetThreadInWasmThreadLocalAddress();
+V8_NOINLINE TH_EXPORT_PRIVATE int* GetThreadInWasmThreadLocalAddress();
 
 // On Windows, asan installs its own exception handler which maps shadow
 // memory. Since our exception handler may be executed before the asan exception
 // handler, we have to make sure that asan shadow memory is not accessed here.
-DISABLE_ASAN inline bool IsThreadInWasm() { return g_thread_in_wasm_code; }
+TH_DISABLE_ASAN inline bool IsThreadInWasm() { return g_thread_in_wasm_code; }
 
 inline void SetThreadInWasm() {
   if (IsTrapHandlerEnabled()) {
-    DCHECK(!IsThreadInWasm());
+    TH_DCHECK(!IsThreadInWasm());
     g_thread_in_wasm_code = true;
   }
 }
 
 inline void ClearThreadInWasm() {
   if (IsTrapHandlerEnabled()) {
-    DCHECK(IsThreadInWasm());
+    TH_DCHECK(IsThreadInWasm());
     g_thread_in_wasm_code = false;
   }
 }
 
 bool RegisterDefaultTrapHandler();
-V8_EXPORT_PRIVATE void RemoveTrapHandler();
+TH_EXPORT_PRIVATE void RemoveTrapHandler();
 
 size_t GetRecoveredTrapCount();
 
diff --git a/chromium/v8/src/utils/allocation.cc b/chromium/v8/src/utils/allocation.cc
index db4d3ac13b6..0c7c468d821 100644
--- a/chromium/v8/src/utils/allocation.cc
+++ b/chromium/v8/src/utils/allocation.cc
@@ -5,19 +5,21 @@
 #include "src/utils/allocation.h"
 
 #include <stdlib.h>  // For free, malloc.
+
 #include "src/base/bits.h"
+#include "src/base/bounded-page-allocator.h"
 #include "src/base/lazy-instance.h"
 #include "src/base/logging.h"
 #include "src/base/page-allocator.h"
 #include "src/base/platform/platform.h"
+#include "src/base/sanitizer/lsan-page-allocator.h"
 #include "src/flags/flags.h"
 #include "src/init/v8.h"
-#include "src/sanitizer/lsan-page-allocator.h"
 #include "src/utils/memcopy.h"
 #include "src/utils/vector.h"
 
 #if V8_LIBC_BIONIC
-#include <malloc.h>  // NOLINT
+#include <malloc.h>
 
 #include "src/base/platform/wrappers.h"
 #endif
@@ -293,5 +295,137 @@ void VirtualMemory::FreeReadOnly() {
                   RoundUp(region.size(), page_allocator->AllocatePageSize())));
 }
 
+VirtualMemoryCage::VirtualMemoryCage() = default;
+
+VirtualMemoryCage::~VirtualMemoryCage() { Free(); }
+
+VirtualMemoryCage::VirtualMemoryCage(VirtualMemoryCage&& other) V8_NOEXCEPT {
+  *this = std::move(other);
+}
+
+VirtualMemoryCage& VirtualMemoryCage::operator=(VirtualMemoryCage&& other)
+    V8_NOEXCEPT {
+  page_allocator_ = std::move(other.page_allocator_);
+  reservation_ = std::move(other.reservation_);
+  return *this;
+}
+
+namespace {
+inline Address VirtualMemoryCageStart(
+    Address reservation_start,
+    const VirtualMemoryCage::ReservationParams& params) {
+  return RoundUp(reservation_start + params.base_bias_size,
+                 params.base_alignment) -
+         params.base_bias_size;
+}
+}  // namespace
+
+bool VirtualMemoryCage::InitReservation(const ReservationParams& params) {
+  DCHECK(!reservation_.IsReserved());
+
+  const size_t allocate_page_size = params.page_allocator->AllocatePageSize();
+  CHECK(IsAligned(params.reservation_size, allocate_page_size));
+  CHECK(params.base_alignment == ReservationParams::kAnyBaseAlignment ||
+        (IsAligned(params.base_alignment, allocate_page_size) &&
+         IsAligned(params.base_bias_size, allocate_page_size)));
+  CHECK_LE(params.base_bias_size, params.reservation_size);
+
+  Address hint = RoundDown(params.requested_start_hint,
+                           RoundUp(params.base_alignment, allocate_page_size)) -
+                 RoundUp(params.base_bias_size, allocate_page_size);
+
+  if (params.base_alignment == ReservationParams::kAnyBaseAlignment) {
+    // When the base doesn't need to be aligned, the virtual memory reservation
+    // fails only due to OOM.
+    VirtualMemory reservation(params.page_allocator, params.reservation_size,
+                              reinterpret_cast<void*>(hint));
+    if (!reservation.IsReserved()) return false;
+
+    reservation_ = std::move(reservation);
+    base_ = reservation_.address() + params.base_bias_size;
+    CHECK_EQ(reservation_.size(), params.reservation_size);
+  } else {
+    // Otherwise, we need to try harder by first overreserving
+    // in hopes of finding a correctly aligned address within the larger
+    // reservation.
+    const int kMaxAttempts = 4;
+    for (int attempt = 0; attempt < kMaxAttempts; ++attempt) {
+      // Reserve a region of twice the size so that there is an aligned address
+      // within it that's usable as the cage base.
+      VirtualMemory padded_reservation(params.page_allocator,
+                                       params.reservation_size * 2,
+                                       reinterpret_cast<void*>(hint));
+      if (!padded_reservation.IsReserved()) return false;
+
+      // Find properly aligned sub-region inside the reservation.
+      Address address =
+          VirtualMemoryCageStart(padded_reservation.address(), params);
+      CHECK(padded_reservation.InVM(address, params.reservation_size));
+
+#if defined(V8_OS_FUCHSIA)
+      // Fuchsia does not respect given hints so as a workaround we will use
+      // overreserved address space region instead of trying to re-reserve
+      // a subregion.
+      bool overreserve = true;
+#else
+      // For the last attempt use the overreserved region to avoid an OOM crash.
+      // This case can happen if there are many isolates being created in
+      // parallel that race for reserving the regions.
+      bool overreserve = (attempt == kMaxAttempts - 1);
+#endif
+
+      if (overreserve) {
+        if (padded_reservation.InVM(address, params.reservation_size)) {
+          reservation_ = std::move(padded_reservation);
+          base_ = address + params.base_bias_size;
+          break;
+        }
+      } else {
+        // Now free the padded reservation and immediately try to reserve an
+        // exact region at aligned address. We have to do this dancing because
+        // the reservation address requirement is more complex than just a
+        // certain alignment and not all operating systems support freeing parts
+        // of reserved address space regions.
+        padded_reservation.Free();
+
+        VirtualMemory reservation(params.page_allocator,
+                                  params.reservation_size,
+                                  reinterpret_cast<void*>(address));
+        if (!reservation.IsReserved()) return false;
+
+        // The reservation could still be somewhere else but we can accept it
+        // if it has the required alignment.
+        Address address = VirtualMemoryCageStart(reservation.address(), params);
+        if (reservation.address() == address) {
+          reservation_ = std::move(reservation);
+          base_ = address + params.base_bias_size;
+          CHECK_EQ(reservation_.size(), params.reservation_size);
+          break;
+        }
+      }
+    }
+  }
+  CHECK_NE(base_, kNullAddress);
+  CHECK(IsAligned(base_, params.base_alignment));
+
+  const Address allocatable_base = RoundUp(base_, params.page_size);
+  const size_t allocatable_size =
+      RoundDown(params.reservation_size - (allocatable_base - base_) -
+                    params.base_bias_size,
+                params.page_size);
+  page_allocator_ = std::make_unique<base::BoundedPageAllocator>(
+      params.page_allocator, allocatable_base, allocatable_size,
+      params.page_size);
+  return true;
+}
+
+void VirtualMemoryCage::Free() {
+  if (IsReserved()) {
+    base_ = kNullAddress;
+    page_allocator_.reset();
+    reservation_.Free();
+  }
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/utils/allocation.h b/chromium/v8/src/utils/allocation.h
index 6adefccf8d9..1d161b7e246 100644
--- a/chromium/v8/src/utils/allocation.h
+++ b/chromium/v8/src/utils/allocation.h
@@ -13,6 +13,11 @@
 #include "src/init/v8.h"
 
 namespace v8 {
+
+namespace base {
+class BoundedPageAllocator;
+}  // namespace base
+
 namespace internal {
 
 class Isolate;
@@ -213,7 +218,7 @@ class VirtualMemory final {
 
   v8::PageAllocator* page_allocator() { return page_allocator_; }
 
-  base::AddressRegion region() const { return region_; }
+  const base::AddressRegion& region() const { return region_; }
 
   // Returns the start address of the reserved memory.
   // If the memory was reserved with an alignment, this address is not
@@ -250,7 +255,7 @@ class VirtualMemory final {
   // can be called on a VirtualMemory that is itself not writable.
   V8_EXPORT_PRIVATE void FreeReadOnly();
 
-  bool InVM(Address address, size_t size) {
+  bool InVM(Address address, size_t size) const {
     return region_.contains(address, size);
   }
 
@@ -260,6 +265,102 @@ class VirtualMemory final {
   base::AddressRegion region_;
 };
 
+// Represents a VirtualMemory reservation along with a BoundedPageAllocator that
+// can be used to allocate within the reservation.
+//
+// Virtual memory cages are used for both the pointer compression cage and code
+// ranges (on platforms that require code ranges) and are configurable via
+// ReservationParams.
+//
+// +------------+-----------+-----------  ~~~  -+
+// |     ...    |    ...    |   ...             |
+// +------------+-----------+------------ ~~~  -+
+// ^            ^           ^
+// start        cage base   allocatable base
+//
+// <------------>           <------------------->
+// base bias size              allocatable size
+// <-------------------------------------------->
+//             reservation size
+//
+// - The reservation is made using ReservationParams::page_allocator.
+// - start is the start of the virtual memory reservation.
+// - cage base is the base address of the cage.
+// - allocatable base is the cage base rounded up to the nearest
+//   ReservationParams::page_size, and is the start of the allocatable area for
+//   the BoundedPageAllocator.
+//
+// - The base bias is configured by ReservationParams::base_bias_size.
+// - The reservation size is configured by ReservationParams::reservation_size.
+//
+// Additionally,
+// - The alignment of the cage base is configured by
+//   ReservationParams::base_alignment.
+// - The page size of the BoundedPageAllocator is configured by
+//   ReservationParams::page_size.
+// - A hint for the value of start can be passed by
+//   ReservationParams::requested_start_hint.
+//
+// The configuration is subject to the following alignment requirements.
+// Below, AllocatePageSize is short for
+// ReservationParams::page_allocator->AllocatePageSize().
+//
+// - The reservation size must be AllocatePageSize-aligned.
+// - If the base alignment is not kAnyBaseAlignment, both the base alignment
+//   and the base bias size must be AllocatePageSize-aligned.
+// - The base alignment may be kAnyBaseAlignment to denote any alignment is
+//   acceptable. In this case the base bias size does not need to be aligned.
+class VirtualMemoryCage {
+ public:
+  VirtualMemoryCage();
+  virtual ~VirtualMemoryCage();
+
+  VirtualMemoryCage(const VirtualMemoryCage&) = delete;
+  VirtualMemoryCage& operator=(VirtualMemoryCage&) = delete;
+
+  VirtualMemoryCage(VirtualMemoryCage&& other) V8_NOEXCEPT;
+  VirtualMemoryCage& operator=(VirtualMemoryCage&& other) V8_NOEXCEPT;
+
+  Address base() const { return base_; }
+
+  base::BoundedPageAllocator* page_allocator() const {
+    return page_allocator_.get();
+  }
+
+  VirtualMemory* reservation() { return &reservation_; }
+  const VirtualMemory* reservation() const { return &reservation_; }
+
+  bool IsReserved() const {
+    DCHECK_EQ(base_ != kNullAddress, reservation_.IsReserved());
+    return reservation_.IsReserved();
+  }
+
+  struct ReservationParams {
+    // The allocator to use to reserve the virtual memory.
+    v8::PageAllocator* page_allocator;
+    // See diagram above.
+    size_t reservation_size;
+    size_t base_alignment;
+    size_t base_bias_size;
+    size_t page_size;
+    Address requested_start_hint;
+
+    static constexpr size_t kAnyBaseAlignment = 1;
+  };
+
+  // A number of attempts is made to try to reserve a region that satisfies the
+  // constraints in params, but this may fail. The base address may be different
+  // than the one requested.
+  bool InitReservation(const ReservationParams& params);
+
+  void Free();
+
+ protected:
+  Address base_ = kNullAddress;
+  std::unique_ptr<base::BoundedPageAllocator> page_allocator_;
+  VirtualMemory reservation_;
+};
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/chromium/v8/src/utils/ostreams.cc b/chromium/v8/src/utils/ostreams.cc
index b58f51159b8..a2a6f8574f8 100644
--- a/chromium/v8/src/utils/ostreams.cc
+++ b/chromium/v8/src/utils/ostreams.cc
@@ -19,7 +19,7 @@
 
 #if defined(ANDROID) && !defined(V8_ANDROID_LOG_STDOUT)
 #define LOG_TAG "v8"
-#include <android/log.h>  // NOLINT
+#include <android/log.h>
 #endif
 
 namespace v8 {
diff --git a/chromium/v8/src/utils/ostreams.h b/chromium/v8/src/utils/ostreams.h
index 899c85fd94c..2dfedb5fd95 100644
--- a/chromium/v8/src/utils/ostreams.h
+++ b/chromium/v8/src/utils/ostreams.h
@@ -8,7 +8,7 @@
 #include <cstddef>
 #include <cstdio>
 #include <cstring>
-#include <ostream>  // NOLINT
+#include <ostream>
 #include <streambuf>
 
 #include "include/v8config.h"
@@ -158,10 +158,10 @@ struct PrintIteratorRange {
 // Print any collection which can be iterated via std::begin and std::end.
 // {Iterator} is the common type of {std::begin} and {std::end} called on a
 // {const T&}. This function is only instantiable if that type exists.
-template <typename T, typename Iterator = typename std::common_type<
-                          decltype(std::begin(std::declval<const T&>())),
-                          decltype(std::end(std::declval<const T&>()))>::type>
-PrintIteratorRange<Iterator> PrintCollection(const T& collection) {
+template <typename T>
+auto PrintCollection(const T& collection) -> PrintIteratorRange<
+    typename std::common_type<decltype(std::begin(collection)),
+                              decltype(std::end(collection))>::type> {
   return {std::begin(collection), std::end(collection)};
 }
 
diff --git a/chromium/v8/src/utils/v8dll-main.cc b/chromium/v8/src/utils/v8dll-main.cc
index 255f0d8dbff..6d7f390c8f6 100644
--- a/chromium/v8/src/utils/v8dll-main.cc
+++ b/chromium/v8/src/utils/v8dll-main.cc
@@ -4,7 +4,7 @@
 
 // The GYP based build ends up defining USING_V8_SHARED when compiling this
 // file.
-#undef USING_V8_SHARED  // NOLINT
+#undef USING_V8_SHARED
 #include "include/v8.h"
 
 #if V8_OS_WIN
diff --git a/chromium/v8/src/utils/vector.h b/chromium/v8/src/utils/vector.h
index dad7abf0273..d085f14ab0e 100644
--- a/chromium/v8/src/utils/vector.h
+++ b/chromium/v8/src/utils/vector.h
@@ -28,7 +28,7 @@ class Vector {
   constexpr Vector() : start_(nullptr), length_(0) {}
 
   constexpr Vector(T* data, size_t length) : start_(data), length_(length) {
-    CONSTEXPR_DCHECK(length == 0 || data != nullptr);
+    DCHECK(length == 0 || data != nullptr);
   }
 
   static Vector<T> New(size_t length) {
diff --git a/chromium/v8/src/wasm/OWNERS b/chromium/v8/src/wasm/OWNERS
index d0de7de9357..516dd84d6ee 100644
--- a/chromium/v8/src/wasm/OWNERS
+++ b/chromium/v8/src/wasm/OWNERS
@@ -3,5 +3,6 @@ bbudge@chromium.org
 clemensb@chromium.org
 gdeepti@chromium.org
 jkummerow@chromium.org
+manoskouk@chromium.org
 thibaudm@chromium.org
 zhin@chromium.org
diff --git a/chromium/v8/src/wasm/baseline/arm/liftoff-assembler-arm.h b/chromium/v8/src/wasm/baseline/arm/liftoff-assembler-arm.h
index 62917ab0a34..acc7f08fa07 100644
--- a/chromium/v8/src/wasm/baseline/arm/liftoff-assembler-arm.h
+++ b/chromium/v8/src/wasm/baseline/arm/liftoff-assembler-arm.h
@@ -605,6 +605,8 @@ void LiftoffAssembler::SpillInstance(Register instance) {
   str(instance, liftoff::GetInstanceOperand());
 }
 
+void LiftoffAssembler::ResetOSRTarget() {}
+
 void LiftoffAssembler::FillInstanceInto(Register dst) {
   ldr(dst, liftoff::GetInstanceOperand());
 }
@@ -743,7 +745,7 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
                           : MemOperand(dst_addr, actual_offset_reg);
   str(src.gp(), dst_op);
 
-  if (skip_write_barrier) return;
+  if (skip_write_barrier || FLAG_disable_write_barriers) return;
 
   // The write barrier.
   Label write_barrier;
@@ -758,7 +760,7 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
   CallRecordWriteStub(dst_addr,
                       actual_offset_reg == no_reg ? Operand(offset_imm)
                                                   : Operand(actual_offset_reg),
-                      EMIT_REMEMBERED_SET, kSaveFPRegs,
+                      RememberedSetAction::kEmit, SaveFPRegsMode::kSave,
                       wasm::WasmCode::kRecordWrite);
   bind(&exit);
 }
@@ -4227,6 +4229,8 @@ void LiftoffAssembler::DeallocateStackSlot(uint32_t size) {
   add(sp, sp, Operand(size));
 }
 
+void LiftoffAssembler::MaybeOSR() {}
+
 void LiftoffStackSlots::Construct(int param_slots) {
   DCHECK_LT(0, slots_.size());
   SortInPushOrder();
diff --git a/chromium/v8/src/wasm/baseline/arm64/liftoff-assembler-arm64.h b/chromium/v8/src/wasm/baseline/arm64/liftoff-assembler-arm64.h
index 39ef8528e52..63493edbd30 100644
--- a/chromium/v8/src/wasm/baseline/arm64/liftoff-assembler-arm64.h
+++ b/chromium/v8/src/wasm/baseline/arm64/liftoff-assembler-arm64.h
@@ -127,37 +127,32 @@ template <typename T>
 inline MemOperand GetMemOp(LiftoffAssembler* assm,
                            UseScratchRegisterScope* temps, Register addr,
                            Register offset, T offset_imm) {
-  if (offset.is_valid()) {
-    if (offset_imm == 0) return MemOperand(addr.X(), offset.W(), UXTW);
-    Register tmp = temps->AcquireX();
-    DCHECK_GE(kMaxUInt32, offset_imm);
-    assm->Add(tmp, offset.X(), offset_imm);
-    return MemOperand(addr.X(), tmp);
-  }
-  return MemOperand(addr.X(), offset_imm);
-}
-
-// Certain load instructions do not support offset (register or immediate).
-// This creates a MemOperand that is suitable for such instructions by adding
-// |addr|, |offset| (if needed), and |offset_imm| into a temporary.
-inline MemOperand GetMemOpWithImmOffsetZero(LiftoffAssembler* assm,
-                                            UseScratchRegisterScope* temps,
-                                            Register addr, Register offset,
-                                            uintptr_t offset_imm) {
+  if (!offset.is_valid()) return MemOperand(addr.X(), offset_imm);
+  Register effective_addr = addr.X();
+  if (offset_imm) {
+    effective_addr = temps->AcquireX();
+    assm->Add(effective_addr, addr.X(), offset_imm);
+  }
+  return MemOperand(effective_addr, offset.W(), UXTW);
+}
+
+// Compute the effective address (sum of |addr|, |offset| (if given) and
+// |offset_imm|) into a temporary register. This is needed for certain load
+// instructions that do not support an offset (register or immediate).
+// Returns |addr| if both |offset| and |offset_imm| are zero.
+inline Register GetEffectiveAddress(LiftoffAssembler* assm,
+                                    UseScratchRegisterScope* temps,
+                                    Register addr, Register offset,
+                                    uintptr_t offset_imm) {
+  if (!offset.is_valid() && offset_imm == 0) return addr;
   Register tmp = temps->AcquireX();
   if (offset.is_valid()) {
-    // offset has passed BoundsCheckMem in liftoff-compiler, and been unsigned
-    // extended, so it is fine to use the full width of the register.
-    assm->Add(tmp, addr, offset);
-    if (offset_imm != 0) {
-      assm->Add(tmp, tmp, offset_imm);
-    }
-  } else {
-    if (offset_imm != 0) {
-      assm->Add(tmp, addr, offset_imm);
-    }
+    // TODO(clemensb): This needs adaption for memory64.
+    assm->Add(tmp, addr, Operand(offset, UXTW));
+    addr = tmp;
   }
-  return MemOperand(tmp.X(), 0);
+  if (offset_imm != 0) assm->Add(tmp, addr, offset_imm);
+  return tmp;
 }
 
 enum class ShiftDirection : bool { kLeft, kRight };
@@ -430,6 +425,8 @@ void LiftoffAssembler::SpillInstance(Register instance) {
   Str(instance, liftoff::GetInstanceOperand());
 }
 
+void LiftoffAssembler::ResetOSRTarget() {}
+
 void LiftoffAssembler::FillInstanceInto(Register dst) {
   Ldr(dst, liftoff::GetInstanceOperand());
 }
@@ -458,13 +455,20 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
                                           LiftoffRegister src,
                                           LiftoffRegList pinned,
                                           SkipWriteBarrier skip_write_barrier) {
-  // Store the value.
   UseScratchRegisterScope temps(this);
-  MemOperand dst_op =
-      liftoff::GetMemOp(this, &temps, dst_addr, offset_reg, offset_imm);
-  StoreTaggedField(src.gp(), dst_op);
+  Operand offset_op = offset_reg.is_valid() ? Operand(offset_reg.W(), UXTW)
+                                            : Operand(offset_imm);
+  // For the write barrier (below), we cannot have both an offset register and
+  // an immediate offset. Add them to a 32-bit offset initially, but in a 64-bit
+  // register, because that's needed in the MemOperand below.
+  if (offset_reg.is_valid() && offset_imm) {
+    Register effective_offset = temps.AcquireX();
+    Add(effective_offset.W(), offset_reg.W(), offset_imm);
+    offset_op = effective_offset;
+  }
+  StoreTaggedField(src.gp(), MemOperand(dst_addr.X(), offset_op));
 
-  if (skip_write_barrier) return;
+  if (skip_write_barrier || FLAG_disable_write_barriers) return;
 
   // The write barrier.
   Label write_barrier;
@@ -479,11 +483,8 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
   }
   CheckPageFlag(src.gp(), MemoryChunk::kPointersToHereAreInterestingMask, ne,
                 &exit);
-  CallRecordWriteStub(
-      dst_addr,
-      dst_op.IsRegisterOffset() ? Operand(dst_op.regoffset().X())
-                                : Operand(dst_op.offset()),
-      EMIT_REMEMBERED_SET, kSaveFPRegs, wasm::WasmCode::kRecordWrite);
+  CallRecordWriteStub(dst_addr, offset_op, RememberedSetAction::kEmit,
+                      SaveFPRegsMode::kSave, wasm::WasmCode::kRecordWrite);
   bind(&exit);
 }
 
@@ -1333,7 +1334,7 @@ bool LiftoffAssembler::emit_type_conversion(WasmOpcode opcode,
                                             LiftoffRegister src, Label* trap) {
   switch (opcode) {
     case kExprI32ConvertI64:
-      if (src != dst) Mov(dst.gp().W(), src.gp().W());
+      Mov(dst.gp().W(), src.gp().W());
       return true;
     case kExprI32SConvertF32:
       Fcvtzs(dst.gp().W(), src.fp().S());  // f32 -> i32 round to zero.
@@ -1491,11 +1492,11 @@ bool LiftoffAssembler::emit_type_conversion(WasmOpcode opcode,
 }
 
 void LiftoffAssembler::emit_i32_signextend_i8(Register dst, Register src) {
-  sxtb(dst, src);
+  sxtb(dst.W(), src.W());
 }
 
 void LiftoffAssembler::emit_i32_signextend_i16(Register dst, Register src) {
-  sxth(dst, src);
+  sxth(dst.W(), src.W());
 }
 
 void LiftoffAssembler::emit_i64_signextend_i8(LiftoffRegister dst,
@@ -1629,8 +1630,8 @@ void LiftoffAssembler::LoadTransform(LiftoffRegister dst, Register src_addr,
   UseScratchRegisterScope temps(this);
   MemOperand src_op =
       transform == LoadTransformationKind::kSplat
-          ? liftoff::GetMemOpWithImmOffsetZero(this, &temps, src_addr,
-                                               offset_reg, offset_imm)
+          ? MemOperand{liftoff::GetEffectiveAddress(this, &temps, src_addr,
+                                                    offset_reg, offset_imm)}
           : liftoff::GetMemOp(this, &temps, src_addr, offset_reg, offset_imm);
   *protected_load_pc = pc_offset();
   MachineType memtype = type.mem_type();
@@ -1681,8 +1682,8 @@ void LiftoffAssembler::LoadLane(LiftoffRegister dst, LiftoffRegister src,
                                 uintptr_t offset_imm, LoadType type,
                                 uint8_t laneidx, uint32_t* protected_load_pc) {
   UseScratchRegisterScope temps(this);
-  MemOperand src_op = liftoff::GetMemOpWithImmOffsetZero(
-      this, &temps, addr, offset_reg, offset_imm);
+  MemOperand src_op{
+      liftoff::GetEffectiveAddress(this, &temps, addr, offset_reg, offset_imm)};
   *protected_load_pc = pc_offset();
 
   MachineType mem_type = type.mem_type();
@@ -1708,8 +1709,8 @@ void LiftoffAssembler::StoreLane(Register dst, Register offset,
                                  StoreType type, uint8_t lane,
                                  uint32_t* protected_store_pc) {
   UseScratchRegisterScope temps(this);
-  MemOperand dst_op =
-      liftoff::GetMemOpWithImmOffsetZero(this, &temps, dst, offset, offset_imm);
+  MemOperand dst_op{
+      liftoff::GetEffectiveAddress(this, &temps, dst, offset, offset_imm)};
   if (protected_store_pc) *protected_store_pc = pc_offset();
 
   MachineRepresentation rep = type.mem_rep();
@@ -3221,6 +3222,8 @@ void LiftoffAssembler::DeallocateStackSlot(uint32_t size) {
   Drop(size, 1);
 }
 
+void LiftoffAssembler::MaybeOSR() {}
+
 void LiftoffStackSlots::Construct(int param_slots) {
   DCHECK_LT(0, slots_.size());
   // The stack pointer is required to be quadword aligned.
diff --git a/chromium/v8/src/wasm/baseline/ia32/liftoff-assembler-ia32.h b/chromium/v8/src/wasm/baseline/ia32/liftoff-assembler-ia32.h
index 83b00d4a2ad..9f35b5efc3f 100644
--- a/chromium/v8/src/wasm/baseline/ia32/liftoff-assembler-ia32.h
+++ b/chromium/v8/src/wasm/baseline/ia32/liftoff-assembler-ia32.h
@@ -332,6 +332,8 @@ void LiftoffAssembler::SpillInstance(Register instance) {
   mov(liftoff::GetInstanceOperand(), instance);
 }
 
+void LiftoffAssembler::ResetOSRTarget() {}
+
 void LiftoffAssembler::FillInstanceInto(Register dst) {
   mov(dst, liftoff::GetInstanceOperand());
 }
@@ -365,7 +367,7 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
                        : Operand(dst_addr, offset_reg, times_1, offset_imm);
   mov(dst_op, src.gp());
 
-  if (skip_write_barrier) return;
+  if (skip_write_barrier || FLAG_disable_write_barriers) return;
 
   Register scratch = pinned.set(GetUnusedRegister(kGpReg, pinned)).gp();
   Label write_barrier;
@@ -380,8 +382,8 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
                 MemoryChunk::kPointersToHereAreInterestingMask, zero, &exit,
                 Label::kNear);
   lea(scratch, dst_op);
-  CallRecordWriteStub(dst_addr, scratch, EMIT_REMEMBERED_SET, kSaveFPRegs,
-                      wasm::WasmCode::kRecordWrite);
+  CallRecordWriteStub(dst_addr, scratch, RememberedSetAction::kEmit,
+                      SaveFPRegsMode::kSave, wasm::WasmCode::kRecordWrite);
   bind(&exit);
 }
 
@@ -2932,15 +2934,7 @@ void LiftoffAssembler::emit_i64x2_splat(LiftoffRegister dst,
 
 void LiftoffAssembler::emit_f32x4_splat(LiftoffRegister dst,
                                         LiftoffRegister src) {
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    vshufps(dst.fp(), src.fp(), src.fp(), 0);
-  } else {
-    if (dst.fp() != src.fp()) {
-      movss(dst.fp(), src.fp());
-    }
-    shufps(dst.fp(), src.fp(), 0);
-  }
+  F32x4Splat(dst.fp(), src.fp());
 }
 
 void LiftoffAssembler::emit_f64x2_splat(LiftoffRegister dst,
@@ -3262,13 +3256,7 @@ void LiftoffAssembler::emit_s128_const(LiftoffRegister dst,
 }
 
 void LiftoffAssembler::emit_s128_not(LiftoffRegister dst, LiftoffRegister src) {
-  if (dst.fp() != src.fp()) {
-    Pcmpeqd(dst.fp(), dst.fp());
-    Pxor(dst.fp(), src.fp());
-  } else {
-    Pcmpeqd(liftoff::kScratchDoubleReg, liftoff::kScratchDoubleReg);
-    Pxor(dst.fp(), liftoff::kScratchDoubleReg);
-  }
+  S128Not(dst.fp(), src.fp(), liftoff::kScratchDoubleReg);
 }
 
 void LiftoffAssembler::emit_s128_and(LiftoffRegister dst, LiftoffRegister lhs,
@@ -3849,16 +3837,7 @@ void LiftoffAssembler::emit_i32x4_extmul_high_i16x8_u(LiftoffRegister dst,
 
 void LiftoffAssembler::emit_i64x2_neg(LiftoffRegister dst,
                                       LiftoffRegister src) {
-  DoubleRegister reg =
-      dst.fp() == src.fp() ? liftoff::kScratchDoubleReg : dst.fp();
-  Pxor(reg, reg);
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    vpsubq(dst.fp(), reg, src.fp());
-  } else {
-    psubq(reg, src.fp());
-    if (dst.fp() != reg) movaps(dst.fp(), reg);
-  }
+  I64x2Neg(dst.fp(), src.fp(), liftoff::kScratchDoubleReg);
 }
 
 void LiftoffAssembler::emit_i64x2_alltrue(LiftoffRegister dst,
@@ -3892,7 +3871,7 @@ void LiftoffAssembler::emit_i64x2_shr_s(LiftoffRegister dst,
 
   // Set up a mask [0x80000000,0,0x80000000,0].
   Pcmpeqb(tmp, tmp);
-  Psllq(tmp, tmp, 63);
+  Psllq(tmp, tmp, byte{63});
 
   Psrlq(tmp, tmp, shift);
   if (CpuFeatures::IsSupported(AVX)) {
@@ -3911,11 +3890,11 @@ void LiftoffAssembler::emit_i64x2_shr_s(LiftoffRegister dst,
 void LiftoffAssembler::emit_i64x2_shri_s(LiftoffRegister dst,
                                          LiftoffRegister lhs, int32_t rhs) {
   XMMRegister tmp = liftoff::kScratchDoubleReg;
-  int32_t shift = rhs & 63;
+  byte shift = rhs & 63;
 
   // Set up a mask [0x80000000,0,0x80000000,0].
   Pcmpeqb(tmp, tmp);
-  Psllq(tmp, tmp, 63);
+  Psllq(tmp, tmp, byte{63});
 
   Psrlq(tmp, tmp, shift);
   liftoff::EmitSimdShiftOpImm<&Assembler::vpsrlq, &Assembler::psrlq, 6>(
@@ -3959,13 +3938,13 @@ void LiftoffAssembler::emit_i64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
   Movaps(tmp1.fp(), lhs.fp());
   Movaps(tmp2.fp(), rhs.fp());
   // Multiply high dword of each qword of left with right.
-  Psrlq(tmp1.fp(), 32);
+  Psrlq(tmp1.fp(), byte{32});
   Pmuludq(tmp1.fp(), tmp1.fp(), rhs.fp());
   // Multiply high dword of each qword of right with left.
-  Psrlq(tmp2.fp(), 32);
+  Psrlq(tmp2.fp(), byte{32});
   Pmuludq(tmp2.fp(), tmp2.fp(), lhs.fp());
   Paddq(tmp2.fp(), tmp2.fp(), tmp1.fp());
-  Psllq(tmp2.fp(), tmp2.fp(), 32);
+  Psllq(tmp2.fp(), tmp2.fp(), byte{32});
   liftoff::EmitSimdCommutativeBinOp<&Assembler::vpmuludq, &Assembler::pmuludq>(
       this, dst, lhs, rhs);
   Paddq(dst.fp(), dst.fp(), tmp2.fp());
@@ -4028,11 +4007,11 @@ void LiftoffAssembler::emit_f32x4_abs(LiftoffRegister dst,
                                       LiftoffRegister src) {
   if (dst.fp() == src.fp()) {
     Pcmpeqd(liftoff::kScratchDoubleReg, liftoff::kScratchDoubleReg);
-    Psrld(liftoff::kScratchDoubleReg, liftoff::kScratchDoubleReg, 1);
+    Psrld(liftoff::kScratchDoubleReg, liftoff::kScratchDoubleReg, byte{1});
     Andps(dst.fp(), liftoff::kScratchDoubleReg);
   } else {
     Pcmpeqd(dst.fp(), dst.fp());
-    Psrld(dst.fp(), dst.fp(), 1);
+    Psrld(dst.fp(), dst.fp(), byte{1});
     Andps(dst.fp(), src.fp());
   }
 }
@@ -4041,11 +4020,11 @@ void LiftoffAssembler::emit_f32x4_neg(LiftoffRegister dst,
                                       LiftoffRegister src) {
   if (dst.fp() == src.fp()) {
     Pcmpeqd(liftoff::kScratchDoubleReg, liftoff::kScratchDoubleReg);
-    Pslld(liftoff::kScratchDoubleReg, liftoff::kScratchDoubleReg, 31);
+    Pslld(liftoff::kScratchDoubleReg, liftoff::kScratchDoubleReg, byte{31});
     Xorps(dst.fp(), liftoff::kScratchDoubleReg);
   } else {
     Pcmpeqd(dst.fp(), dst.fp());
-    Pslld(dst.fp(), dst.fp(), 31);
+    Pslld(dst.fp(), dst.fp(), byte{31});
     Xorps(dst.fp(), src.fp());
   }
 }
@@ -4184,11 +4163,11 @@ void LiftoffAssembler::emit_f64x2_abs(LiftoffRegister dst,
                                       LiftoffRegister src) {
   if (dst.fp() == src.fp()) {
     Pcmpeqd(liftoff::kScratchDoubleReg, liftoff::kScratchDoubleReg);
-    Psrlq(liftoff::kScratchDoubleReg, liftoff::kScratchDoubleReg, 1);
+    Psrlq(liftoff::kScratchDoubleReg, liftoff::kScratchDoubleReg, byte{1});
     Andpd(dst.fp(), liftoff::kScratchDoubleReg);
   } else {
     Pcmpeqd(dst.fp(), dst.fp());
-    Psrlq(dst.fp(), dst.fp(), 1);
+    Psrlq(dst.fp(), dst.fp(), byte{1});
     Andpd(dst.fp(), src.fp());
   }
 }
@@ -4197,11 +4176,11 @@ void LiftoffAssembler::emit_f64x2_neg(LiftoffRegister dst,
                                       LiftoffRegister src) {
   if (dst.fp() == src.fp()) {
     Pcmpeqd(liftoff::kScratchDoubleReg, liftoff::kScratchDoubleReg);
-    Psllq(liftoff::kScratchDoubleReg, liftoff::kScratchDoubleReg, 63);
+    Psllq(liftoff::kScratchDoubleReg, liftoff::kScratchDoubleReg, byte{63});
     Xorpd(dst.fp(), liftoff::kScratchDoubleReg);
   } else {
     Pcmpeqd(dst.fp(), dst.fp());
-    Psllq(dst.fp(), dst.fp(), 63);
+    Psllq(dst.fp(), dst.fp(), byte{63});
     Xorpd(dst.fp(), src.fp());
   }
 }
@@ -4265,61 +4244,12 @@ void LiftoffAssembler::emit_f64x2_div(LiftoffRegister dst, LiftoffRegister lhs,
 
 void LiftoffAssembler::emit_f64x2_min(LiftoffRegister dst, LiftoffRegister lhs,
                                       LiftoffRegister rhs) {
-  // The minpd instruction doesn't propagate NaNs and +0's in its first
-  // operand. Perform minpd in both orders, merge the results, and adjust.
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    vminpd(liftoff::kScratchDoubleReg, lhs.fp(), rhs.fp());
-    vminpd(dst.fp(), rhs.fp(), lhs.fp());
-  } else if (dst.fp() == lhs.fp() || dst.fp() == rhs.fp()) {
-    XMMRegister src = dst.fp() == lhs.fp() ? rhs.fp() : lhs.fp();
-    movaps(liftoff::kScratchDoubleReg, src);
-    minpd(liftoff::kScratchDoubleReg, dst.fp());
-    minpd(dst.fp(), src);
-  } else {
-    movaps(liftoff::kScratchDoubleReg, lhs.fp());
-    minpd(liftoff::kScratchDoubleReg, rhs.fp());
-    movaps(dst.fp(), rhs.fp());
-    minpd(dst.fp(), lhs.fp());
-  }
-  // propagate -0's and NaNs, which may be non-canonical.
-  Orpd(liftoff::kScratchDoubleReg, dst.fp());
-  // Canonicalize NaNs by quieting and clearing the payload.
-  Cmpunordpd(dst.fp(), dst.fp(), liftoff::kScratchDoubleReg);
-  Orpd(liftoff::kScratchDoubleReg, dst.fp());
-  Psrlq(dst.fp(), 13);
-  Andnpd(dst.fp(), liftoff::kScratchDoubleReg);
+  F64x2Min(dst.fp(), lhs.fp(), rhs.fp(), liftoff::kScratchDoubleReg);
 }
 
 void LiftoffAssembler::emit_f64x2_max(LiftoffRegister dst, LiftoffRegister lhs,
                                       LiftoffRegister rhs) {
-  // The maxpd instruction doesn't propagate NaNs and +0's in its first
-  // operand. Perform maxpd in both orders, merge the results, and adjust.
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    vmaxpd(liftoff::kScratchDoubleReg, lhs.fp(), rhs.fp());
-    vmaxpd(dst.fp(), rhs.fp(), lhs.fp());
-  } else if (dst.fp() == lhs.fp() || dst.fp() == rhs.fp()) {
-    XMMRegister src = dst.fp() == lhs.fp() ? rhs.fp() : lhs.fp();
-    movaps(liftoff::kScratchDoubleReg, src);
-    maxpd(liftoff::kScratchDoubleReg, dst.fp());
-    maxpd(dst.fp(), src);
-  } else {
-    movaps(liftoff::kScratchDoubleReg, lhs.fp());
-    maxpd(liftoff::kScratchDoubleReg, rhs.fp());
-    movaps(dst.fp(), rhs.fp());
-    maxpd(dst.fp(), lhs.fp());
-  }
-  // Find discrepancies.
-  Xorpd(dst.fp(), liftoff::kScratchDoubleReg);
-  // Propagate NaNs, which may be non-canonical.
-  Orpd(liftoff::kScratchDoubleReg, dst.fp());
-  // Propagate sign discrepancy and (subtle) quiet NaNs.
-  Subpd(liftoff::kScratchDoubleReg, liftoff::kScratchDoubleReg, dst.fp());
-  // Canonicalize NaNs by clearing the payload. Sign is non-deterministic.
-  Cmpunordpd(dst.fp(), dst.fp(), liftoff::kScratchDoubleReg);
-  Psrlq(dst.fp(), 13);
-  Andnpd(dst.fp(), liftoff::kScratchDoubleReg);
+  F64x2Max(dst.fp(), lhs.fp(), rhs.fp(), liftoff::kScratchDoubleReg);
 }
 
 void LiftoffAssembler::emit_f64x2_pmin(LiftoffRegister dst, LiftoffRegister lhs,
@@ -4616,25 +4546,13 @@ void LiftoffAssembler::emit_i64x2_extract_lane(LiftoffRegister dst,
 void LiftoffAssembler::emit_f32x4_extract_lane(LiftoffRegister dst,
                                                LiftoffRegister lhs,
                                                uint8_t imm_lane_idx) {
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    vshufps(dst.fp(), lhs.fp(), lhs.fp(), imm_lane_idx);
-  } else {
-    if (dst.fp() != lhs.fp()) movaps(dst.fp(), lhs.fp());
-    if (imm_lane_idx != 0) shufps(dst.fp(), dst.fp(), imm_lane_idx);
-  }
+  F32x4ExtractLane(dst.fp(), lhs.fp(), imm_lane_idx);
 }
 
 void LiftoffAssembler::emit_f64x2_extract_lane(LiftoffRegister dst,
                                                LiftoffRegister lhs,
                                                uint8_t imm_lane_idx) {
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    vshufpd(dst.fp(), lhs.fp(), lhs.fp(), imm_lane_idx);
-  } else {
-    if (dst.fp() != lhs.fp()) movaps(dst.fp(), lhs.fp());
-    if (imm_lane_idx != 0) shufpd(dst.fp(), dst.fp(), imm_lane_idx);
-  }
+  F64x2ExtractLane(dst.fp(), lhs.fp(), imm_lane_idx);
 }
 
 void LiftoffAssembler::emit_i8x16_replace_lane(LiftoffRegister dst,
@@ -4712,27 +4630,7 @@ void LiftoffAssembler::emit_f64x2_replace_lane(LiftoffRegister dst,
                                                LiftoffRegister src1,
                                                LiftoffRegister src2,
                                                uint8_t imm_lane_idx) {
-  // TODO(fanchenk): Use movlhps and blendpd
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    if (imm_lane_idx == 0) {
-      vinsertps(dst.fp(), src1.fp(), src2.fp(), 0b00000000);
-      vinsertps(dst.fp(), dst.fp(), src2.fp(), 0b01010000);
-    } else {
-      vinsertps(dst.fp(), src1.fp(), src2.fp(), 0b00100000);
-      vinsertps(dst.fp(), dst.fp(), src2.fp(), 0b01110000);
-    }
-  } else {
-    CpuFeatureScope scope(this, SSE4_1);
-    if (dst.fp() != src1.fp()) movaps(dst.fp(), src1.fp());
-    if (imm_lane_idx == 0) {
-      insertps(dst.fp(), src2.fp(), 0b00000000);
-      insertps(dst.fp(), src2.fp(), 0b01010000);
-    } else {
-      insertps(dst.fp(), src2.fp(), 0b00100000);
-      insertps(dst.fp(), src2.fp(), 0b01110000);
-    }
-  }
+  F64x2ReplaceLane(dst.fp(), src1.fp(), src2.fp(), imm_lane_idx);
 }
 
 void LiftoffAssembler::StackCheck(Label* ool_code, Register limit_address) {
@@ -4906,6 +4804,8 @@ void LiftoffAssembler::DeallocateStackSlot(uint32_t size) {
   add(esp, Immediate(size));
 }
 
+void LiftoffAssembler::MaybeOSR() {}
+
 void LiftoffStackSlots::Construct(int param_slots) {
   DCHECK_LT(0, slots_.size());
   SortInPushOrder();
diff --git a/chromium/v8/src/wasm/baseline/liftoff-assembler.cc b/chromium/v8/src/wasm/baseline/liftoff-assembler.cc
index a544460ab98..f8b01ac960d 100644
--- a/chromium/v8/src/wasm/baseline/liftoff-assembler.cc
+++ b/chromium/v8/src/wasm/baseline/liftoff-assembler.cc
@@ -738,22 +738,36 @@ void LiftoffAssembler::MergeStackWith(CacheState& target, uint32_t arity,
                                 cache_state_.stack_state[stack_base + i]);
   }
 
+  // Check whether the cached instance needs to be moved to another register.
+  // Register moves are executed as part of the {StackTransferRecipe}. Remember
+  // whether the register content has to be reloaded after executing the stack
+  // transfers.
+  bool reload_instance = false;
+  // If the registers match, or the destination has no cache register, nothing
+  // needs to be done.
   if (cache_state_.cached_instance != target.cached_instance &&
       target.cached_instance != no_reg) {
+    // On forward jumps, just reset the cached register in the target state.
     if (jump_direction == kForwardJump) {
-      // On forward jumps, just reset the cached instance in the target state.
       target.ClearCachedInstanceRegister();
+    } else if (cache_state_.cached_instance != no_reg) {
+      // If the source has the content but in the wrong register, execute a
+      // register move as part of the stack transfer.
+      transfers.MoveRegister(LiftoffRegister{target.cached_instance},
+                             LiftoffRegister{cache_state_.cached_instance},
+                             kPointerKind);
     } else {
-      // On backward jumps, we already generated code assuming that the instance
-      // is available in that register. Thus move it there.
-      if (cache_state_.cached_instance == no_reg) {
-        LoadInstanceFromFrame(target.cached_instance);
-      } else {
-        Move(target.cached_instance, cache_state_.cached_instance,
-             kPointerKind);
-      }
+      // Otherwise (the source state has no cached content), we reload later.
+      reload_instance = true;
     }
   }
+
+  // Now execute stack transfers and register moves/loads.
+  transfers.Execute();
+
+  if (reload_instance) {
+    LoadInstanceFromFrame(target.cached_instance);
+  }
 }
 
 void LiftoffAssembler::Spill(VarState* slot) {
diff --git a/chromium/v8/src/wasm/baseline/liftoff-assembler.h b/chromium/v8/src/wasm/baseline/liftoff-assembler.h
index 3090bc81659..b0439dc4e10 100644
--- a/chromium/v8/src/wasm/baseline/liftoff-assembler.h
+++ b/chromium/v8/src/wasm/baseline/liftoff-assembler.h
@@ -341,6 +341,11 @@ class LiftoffAssembler : public TurboAssembler {
     }
 
     void clear_used(LiftoffRegister reg) {
+      if (reg.is_pair()) {
+        clear_used(reg.low());
+        clear_used(reg.high());
+        return;
+      }
       register_use_count[reg.liftoff_code()] = 0;
       used_registers.clear(reg);
     }
@@ -633,6 +638,7 @@ class LiftoffAssembler : public TurboAssembler {
   inline void LoadTaggedPointerFromInstance(Register dst, Register instance,
                                             int offset);
   inline void SpillInstance(Register instance);
+  inline void ResetOSRTarget();
   inline void FillInstanceInto(Register dst);
   inline void LoadTaggedPointer(Register dst, Register src_addr,
                                 Register offset_reg, int32_t offset_imm,
@@ -1416,6 +1422,9 @@ class LiftoffAssembler : public TurboAssembler {
   inline void AllocateStackSlot(Register addr, uint32_t size);
   inline void DeallocateStackSlot(uint32_t size);
 
+  // Instrumentation for shadow-stack-compatible OSR on x64.
+  inline void MaybeOSR();
+
   ////////////////////////////////////
   // End of platform-specific part. //
   ////////////////////////////////////
diff --git a/chromium/v8/src/wasm/baseline/liftoff-compiler.cc b/chromium/v8/src/wasm/baseline/liftoff-compiler.cc
index a26df172252..e6048374015 100644
--- a/chromium/v8/src/wasm/baseline/liftoff-compiler.cc
+++ b/chromium/v8/src/wasm/baseline/liftoff-compiler.cc
@@ -10,7 +10,7 @@
 #include "src/codegen/assembler-inl.h"
 // TODO(clemensb): Remove dependences on compiler stuff.
 #include "src/codegen/external-reference.h"
-#include "src/codegen/interface-descriptors.h"
+#include "src/codegen/interface-descriptors-inl.h"
 #include "src/codegen/machine-type.h"
 #include "src/codegen/macro-assembler-inl.h"
 #include "src/compiler/linkage.h"
@@ -75,7 +75,7 @@ struct assert_field_size {
   __ LoadTaggedPointerFromInstance(dst, LoadInstanceIntoRegister(pinned, dst), \
                                    WASM_INSTANCE_OBJECT_FIELD_OFFSET(name));
 
-#ifdef DEBUG
+#ifdef V8_CODE_COMMENTS
 #define DEBUG_CODE_COMMENT(str) \
   do {                          \
     __ RecordComment(str);      \
@@ -151,12 +151,7 @@ constexpr LiftoffCondition GetCompareCondition(WasmOpcode opcode) {
     case kExprI32GeU:
       return kUnsignedGreaterEqual;
     default:
-#if V8_HAS_CXX14_CONSTEXPR
       UNREACHABLE();
-#else
-      // We need to return something for old compilers here.
-      return kEqual;
-#endif
   }
 }
 
@@ -362,7 +357,6 @@ class LiftoffCompiler {
     Label catch_label;
     bool catch_reached = false;
     bool in_handler = false;
-    int32_t previous_catch = -1;
   };
 
   struct Control : public ControlBase<Value, validate> {
@@ -594,8 +588,7 @@ class LiftoffCompiler {
     }
   }
 
-  // TODO(ahaas): Make this function constexpr once GCC allows it.
-  LiftoffRegList RegsUnusedByParams() {
+  constexpr static LiftoffRegList RegsUnusedByParams() {
     LiftoffRegList regs = kGpCacheRegList;
     for (auto reg : kGpParamRegisters) {
       regs.clear(reg);
@@ -620,8 +613,9 @@ class LiftoffCompiler {
       // For reference type parameters we have to use registers that were not
       // used for parameters because some reference type stack parameters may
       // get processed before some value type register parameters.
+      static constexpr auto kRegsUnusedByParams = RegsUnusedByParams();
       LiftoffRegister reg = is_reference(reg_kind)
-                                ? __ GetUnusedRegister(RegsUnusedByParams())
+                                ? __ GetUnusedRegister(kRegsUnusedByParams)
                                 : __ GetUnusedRegister(rc, pinned);
       __ LoadCallerFrameSlot(reg, -location.AsCallerFrameSlot(), reg_kind);
       return reg;
@@ -742,6 +736,7 @@ class LiftoffCompiler {
     // Store the instance parameter to a special stack slot.
     __ SpillInstance(kWasmInstanceRegister);
     __ cache_state()->SetInstanceCacheRegister(kWasmInstanceRegister);
+    if (for_debugging_) __ ResetOSRTarget();
 
     // Process parameters.
     if (num_params) DEBUG_CODE_COMMENT("process parameters");
@@ -909,6 +904,9 @@ class LiftoffCompiler {
       ool->debug_sidetable_entry_builder->set_pc_offset(__ pc_offset());
     }
     DCHECK_EQ(ool->continuation.get()->is_bound(), is_stack_check);
+    if (is_stack_check) {
+      MaybeOSR();
+    }
     if (!ool->regs_to_save.is_empty()) __ PopRegisters(ool->regs_to_save);
     if (is_stack_check) {
       if (V8_UNLIKELY(ool->spilled_registers != nullptr)) {
@@ -1046,6 +1044,7 @@ class LiftoffCompiler {
     DefineSafepointWithCalleeSavedRegisters();
     RegisterDebugSideTableEntry(decoder,
                                 DebugSideTableBuilder::kAllowRegisters);
+    MaybeOSR();
   }
 
   void PushControl(Control* block) {
@@ -1072,16 +1071,14 @@ class LiftoffCompiler {
     // Save the current cache state for the merge when jumping to this loop.
     loop->label_state.Split(*__ cache_state());
 
+    PushControl(loop);
+
     // Execute a stack check in the loop header.
     StackCheck(decoder, decoder->position());
-
-    PushControl(loop);
   }
 
   void Try(FullDecoder* decoder, Control* block) {
     block->try_info = std::make_unique<TryInfo>();
-    block->try_info->previous_catch = current_catch_;
-    current_catch_ = static_cast<int32_t>(decoder->control_depth() - 1);
     PushControl(block);
   }
 
@@ -1114,7 +1111,6 @@ class LiftoffCompiler {
                       const ExceptionIndexImmediate<validate>& imm,
                       Control* block, Vector<Value> values) {
     DCHECK(block->is_try_catch());
-    current_catch_ = block->try_info->previous_catch;  // Pop try scope.
     __ emit_jump(block->label.get());
 
     // The catch block is unreachable if no possible throws in the try block
@@ -1181,6 +1177,7 @@ class LiftoffCompiler {
       if (depth == decoder->control_depth() - 1) {
         // Delegate to the caller, do not emit a landing pad.
         Rethrow(decoder, __ cache_state()->stack_state.back());
+        MaybeOSR();
       } else {
         DCHECK(target->is_incomplete_try());
         if (!target->try_info->catch_reached) {
@@ -1194,14 +1191,15 @@ class LiftoffCompiler {
         __ emit_jump(&target->try_info->catch_label);
       }
     }
-    current_catch_ = block->try_info->previous_catch;
   }
 
   void Rethrow(FullDecoder* decoder, Control* try_block) {
     int index = try_block->try_info->catch_state.stack_height() - 1;
     auto& exception = __ cache_state()->stack_state[index];
     Rethrow(decoder, exception);
-    EmitLandingPad(decoder);
+    int pc_offset = __ pc_offset();
+    MaybeOSR();
+    EmitLandingPad(decoder, pc_offset);
   }
 
   void CatchAll(FullDecoder* decoder, Control* block) {
@@ -1209,8 +1207,6 @@ class LiftoffCompiler {
            block->is_try_unwind());
     DCHECK_EQ(decoder->control_at(0), block);
 
-    current_catch_ = block->try_info->previous_catch;  // Pop try scope.
-
     // The catch block is unreachable if no possible throws in the try block
     // exist. We only build a landing pad if some node in the try block can
     // (possibly) throw. Otherwise the catch environments remain empty.
@@ -1340,8 +1336,6 @@ class LiftoffCompiler {
     if (!c->label.get()->is_bound()) __ bind(c->label.get());
   }
 
-  void EndControl(FullDecoder* decoder, Control* c) {}
-
   void GenerateCCall(const LiftoffRegister* result_regs,
                      const ValueKindSig* sig, ValueKind out_argument_kind,
                      const LiftoffRegister* arg_regs,
@@ -3152,6 +3146,32 @@ class LiftoffCompiler {
     __ PushRegister(kRef, ref);
   }
 
+  void BrOnNonNull(FullDecoder* decoder, const Value& ref_object,
+                   uint32_t depth) {
+    // Before branching, materialize all constants. This avoids repeatedly
+    // materializing them for each conditional branch.
+    if (depth != decoder->control_depth() - 1) {
+      __ MaterializeMergedConstants(
+          decoder->control_at(depth)->br_merge()->arity);
+    }
+
+    Label cont_false;
+    LiftoffRegList pinned;
+    LiftoffRegister ref = pinned.set(__ PopToRegister(pinned));
+    // Put the reference back onto the stack for the branch.
+    __ PushRegister(kRef, ref);
+
+    Register null = __ GetUnusedRegister(kGpReg, pinned).gp();
+    LoadNullValue(null, pinned);
+    __ emit_cond_jump(kEqual, &cont_false, ref_object.type.kind(), ref.gp(),
+                      null);
+
+    BrOrRet(decoder, depth, 0);
+    // Drop the reference if we are not branching.
+    __ DropValues(1);
+    __ bind(&cont_false);
+  }
+
   template <ValueKind src_kind, ValueKind result_kind, typename EmitFn>
   void EmitTerOp(EmitFn fn) {
     static constexpr RegClass src_rc = reg_class_for(src_kind);
@@ -4054,22 +4074,22 @@ class LiftoffCompiler {
     DCHECK_EQ(index, WasmExceptionPackage::GetEncodedSize(exception));
   }
 
-  void EmitLandingPad(FullDecoder* decoder) {
-    if (current_catch_ == -1) return;
+  void EmitLandingPad(FullDecoder* decoder, int handler_offset) {
+    if (decoder->current_catch() == -1) return;
     MovableLabel handler;
-    int handler_offset = __ pc_offset();
 
     // If we return from the throwing code normally, just skip over the handler.
     Label skip_handler;
     __ emit_jump(&skip_handler);
 
     // Handler: merge into the catch state, and jump to the catch body.
+    DEBUG_CODE_COMMENT("-- landing pad --");
     __ bind(handler.get());
     __ ExceptionHandler();
     __ PushException();
     handlers_.push_back({std::move(handler), handler_offset});
     Control* current_try =
-        decoder->control_at(decoder->control_depth() - 1 - current_catch_);
+        decoder->control_at(decoder->control_depth_of_current_catch());
     DCHECK_NOT_NULL(current_try->try_info);
     if (!current_try->try_info->catch_reached) {
       current_try->try_info->catch_state.InitMerge(
@@ -4102,6 +4122,7 @@ class LiftoffCompiler {
                     {LiftoffAssembler::VarState{
                         kSmiKind, LiftoffRegister{encoded_size_reg}, 0}},
                     decoder->position());
+    MaybeOSR();
 
     // The FixedArray for the exception values is now in the first gp return
     // register.
@@ -4136,7 +4157,9 @@ class LiftoffCompiler {
                      LiftoffAssembler::VarState{kPointerKind, values_array, 0}},
                     decoder->position());
 
-    EmitLandingPad(decoder);
+    int pc_offset = __ pc_offset();
+    MaybeOSR();
+    EmitLandingPad(decoder, pc_offset);
   }
 
   void AtomicStoreMem(FullDecoder* decoder, StoreType type,
@@ -4260,6 +4283,7 @@ class LiftoffCompiler {
     __ DropValues(1);
 
     LiftoffRegister result = expected;
+    if (__ cache_state()->is_used(result)) __ SpillRegister(result);
 
     // We already added the index to addr, so we can just pass no_reg to the
     // assembler now.
@@ -4296,7 +4320,6 @@ class LiftoffCompiler {
                        std::initializer_list<LiftoffAssembler::VarState> params,
                        int position) {
     DEBUG_CODE_COMMENT(
-        // NOLINTNEXTLINE(whitespace/braces)
         (std::string{"call builtin: "} + GetRuntimeStubName(stub_id)).c_str());
     auto interface_descriptor = Builtins::CallInterfaceDescriptorFor(
         RuntimeStubIdToBuiltinName(stub_id));
@@ -4810,6 +4833,18 @@ class LiftoffCompiler {
       StoreObjectField(obj.gp(), no_reg, offset, value, pinned, field_kind);
       pinned.clear(value);
     }
+    if (imm.struct_type->field_count() == 0) {
+      static_assert(Heap::kMinObjectSizeInTaggedWords == 2 &&
+                        WasmStruct::kHeaderSize == kTaggedSize,
+                    "empty structs need exactly one padding field");
+      ValueKind field_kind = ValueKind::kRef;
+      LiftoffRegister value = pinned.set(__ GetUnusedRegister(kGpReg, pinned));
+      LoadNullValue(value.gp(), pinned);
+      StoreObjectField(obj.gp(), no_reg,
+                       wasm::ObjectAccess::ToTagged(WasmStruct::kHeaderSize),
+                       value, pinned, field_kind);
+      pinned.clear(value);
+    }
     __ PushRegister(kRef, obj);
   }
 
@@ -5426,6 +5461,7 @@ class LiftoffCompiler {
         source_position_table_builder_.AddPosition(
             __ pc_offset(), SourcePosition(decoder->position()), true);
         __ CallIndirect(sig, call_descriptor, target);
+        FinishCall(decoder, sig, call_descriptor);
       }
     } else {
       // A direct call within this module just gets the current instance.
@@ -5443,15 +5479,9 @@ class LiftoffCompiler {
         source_position_table_builder_.AddPosition(
             __ pc_offset(), SourcePosition(decoder->position()), true);
         __ CallNativeWasmCode(addr);
+        FinishCall(decoder, sig, call_descriptor);
       }
     }
-
-    if (!tail_call) {
-      DefineSafepoint();
-      RegisterDebugSideTableEntry(decoder, DebugSideTableBuilder::kDidSpill);
-      EmitLandingPad(decoder);
-      __ FinishCall(sig, call_descriptor);
-    }
   }
 
   void CallIndirect(FullDecoder* decoder, const Value& index_val,
@@ -5546,7 +5576,6 @@ class LiftoffCompiler {
     __ Load(LiftoffRegister(scratch), table, index, 0, LoadType::kI32Load,
             pinned);
 
-    // TODO(9495): Do not always compare signatures, same as wasm-compiler.cc.
     // Compare against expected signature.
     __ LoadConstant(LiftoffRegister(tmp_const), WasmValue(canonical_sig_num));
 
@@ -5617,10 +5646,7 @@ class LiftoffCompiler {
           __ pc_offset(), SourcePosition(decoder->position()), true);
       __ CallIndirect(sig, call_descriptor, target);
 
-      DefineSafepoint();
-      RegisterDebugSideTableEntry(decoder, DebugSideTableBuilder::kDidSpill);
-      EmitLandingPad(decoder);
-      __ FinishCall(sig, call_descriptor);
+      FinishCall(decoder, sig, call_descriptor);
     }
   }
 
@@ -5635,9 +5661,9 @@ class LiftoffCompiler {
     call_descriptor =
         GetLoweredCallDescriptor(compilation_zone_, call_descriptor);
 
-    // Since this is a call instruction, we'll have to spill everything later
-    // anyway; do it right away so that the register state tracking doesn't
-    // get confused by the conditional builtin call below.
+    // Executing a write barrier needs temp registers; doing this on a
+    // conditional branch confuses the LiftoffAssembler's register management.
+    // Spill everything up front to work around that.
     __ SpillAllRegisters();
 
     // We limit ourselves to four registers:
@@ -5652,6 +5678,7 @@ class LiftoffCompiler {
     LiftoffRegister target = pinned.set(__ GetUnusedRegister(kGpReg, pinned));
     LiftoffRegister temp = pinned.set(__ GetUnusedRegister(kGpReg, pinned));
 
+    // Load the WasmFunctionData.
     LiftoffRegister func_data = func_ref;
     __ LoadTaggedPointer(
         func_data.gp(), func_ref.gp(), no_reg,
@@ -5662,144 +5689,65 @@ class LiftoffCompiler {
         wasm::ObjectAccess::ToTagged(SharedFunctionInfo::kFunctionDataOffset),
         pinned);
 
-    LiftoffRegister data_type = instance;
-    __ LoadMap(data_type.gp(), func_data.gp());
-    __ Load(data_type, data_type.gp(), no_reg,
-            wasm::ObjectAccess::ToTagged(Map::kInstanceTypeOffset),
-            LoadType::kI32Load16U, pinned);
+    // Load "ref" (instance or <instance, callable> pair) and target.
+    __ LoadTaggedPointer(
+        instance.gp(), func_data.gp(), no_reg,
+        wasm::ObjectAccess::ToTagged(WasmFunctionData::kRefOffset), pinned);
 
-    Label is_js_function, perform_call;
-    __ emit_i32_cond_jumpi(kEqual, &is_js_function, data_type.gp(),
-                           WASM_JS_FUNCTION_DATA_TYPE);
-    // End of {data_type}'s live range.
+    Label load_target, perform_call;
 
+    // Check if "ref" is a Tuple2.
     {
-      // Call to a WasmExportedFunction.
-
-      LiftoffRegister callee_instance = instance;
-      __ LoadTaggedPointer(callee_instance.gp(), func_data.gp(), no_reg,
-                           wasm::ObjectAccess::ToTagged(
-                               WasmExportedFunctionData::kInstanceOffset),
-                           pinned);
-      LiftoffRegister func_index = target;
-      __ LoadSmiAsInt32(func_index, func_data.gp(),
-                        wasm::ObjectAccess::ToTagged(
-                            WasmExportedFunctionData::kFunctionIndexOffset),
-                        pinned);
-      LiftoffRegister imported_function_refs = temp;
-      __ LoadTaggedPointer(imported_function_refs.gp(), callee_instance.gp(),
-                           no_reg,
-                           wasm::ObjectAccess::ToTagged(
-                               WasmInstanceObject::kImportedFunctionRefsOffset),
-                           pinned);
-      // We overwrite {imported_function_refs} here, at the cost of having
-      // to reload it later, because we don't have more registers on ia32.
-      LiftoffRegister imported_functions_num = imported_function_refs;
-      __ LoadFixedArrayLengthAsInt32(imported_functions_num,
-                                     imported_function_refs.gp(), pinned);
-
-      Label imported;
-      __ emit_cond_jump(kSignedLessThan, &imported, kI32, func_index.gp(),
-                        imported_functions_num.gp());
-
-      {
-        // Function locally defined in module.
-
-        // {func_index} is invalid from here on.
-        LiftoffRegister jump_table_start = target;
-        __ Load(jump_table_start, callee_instance.gp(), no_reg,
-                wasm::ObjectAccess::ToTagged(
-                    WasmInstanceObject::kJumpTableStartOffset),
-                kPointerLoadType, pinned);
-        LiftoffRegister jump_table_offset = temp;
-        __ LoadSmiAsInt32(jump_table_offset, func_data.gp(),
-                          wasm::ObjectAccess::ToTagged(
-                              WasmExportedFunctionData::kJumpTableOffsetOffset),
+      LiftoffRegister pair_map = temp;
+      LiftoffRegister ref_map = target;
+      __ LoadMap(ref_map.gp(), instance.gp());
+      LOAD_INSTANCE_FIELD(pair_map.gp(), IsolateRoot, kSystemPointerSize,
                           pinned);
-        __ emit_ptrsize_add(target.gp(), jump_table_start.gp(),
-                            jump_table_offset.gp());
-        __ emit_jump(&perform_call);
-      }
-
-      {
-        // Function imported to module.
-        __ bind(&imported);
-
-        LiftoffRegister imported_function_targets = temp;
-        __ Load(imported_function_targets, callee_instance.gp(), no_reg,
-                wasm::ObjectAccess::ToTagged(
-                    WasmInstanceObject::kImportedFunctionTargetsOffset),
-                kPointerLoadType, pinned);
-        // {callee_instance} is invalid from here on.
-        LiftoffRegister imported_instance = instance;
-        // Scale {func_index} to kTaggedSize.
-        __ emit_i32_shli(func_index.gp(), func_index.gp(), kTaggedSizeLog2);
-        // {func_data} is invalid from here on.
-        imported_function_refs = func_data;
-        __ LoadTaggedPointer(
-            imported_function_refs.gp(), callee_instance.gp(), no_reg,
-            wasm::ObjectAccess::ToTagged(
-                WasmInstanceObject::kImportedFunctionRefsOffset),
-            pinned);
-        __ LoadTaggedPointer(
-            imported_instance.gp(), imported_function_refs.gp(),
-            func_index.gp(),
-            wasm::ObjectAccess::ElementOffsetInTaggedFixedArray(0), pinned);
-        // Scale {func_index} to kSystemPointerSize.
-        if (kSystemPointerSize == kTaggedSize * 2) {
-          __ emit_i32_add(func_index.gp(), func_index.gp(), func_index.gp());
-        } else {
-          DCHECK_EQ(kSystemPointerSize, kTaggedSize);
-        }
-        // This overwrites the contents of {func_index}, which we don't need
-        // any more.
-        __ Load(target, imported_function_targets.gp(), func_index.gp(), 0,
-                kPointerLoadType, pinned);
-        __ emit_jump(&perform_call);
-      }
-    }
-
-    {
-      // Call to a WasmJSFunction. The call target is
-      // function_data->wasm_to_js_wrapper_code()->instruction_start().
-      // The instance_node is the pair
-      // (current WasmInstanceObject, function_data->callable()).
-      __ bind(&is_js_function);
-
-      LiftoffRegister callable = temp;
-      __ LoadTaggedPointer(
-          callable.gp(), func_data.gp(), no_reg,
-          wasm::ObjectAccess::ToTagged(WasmJSFunctionData::kCallableOffset),
-          pinned);
-
-      // Preserve {func_data} across the call.
-      LiftoffRegList saved_regs = LiftoffRegList::ForRegs(func_data);
-      __ PushRegisters(saved_regs);
+      __ LoadTaggedPointer(pair_map.gp(), pair_map.gp(), no_reg,
+                           IsolateData::root_slot_offset(RootIndex::kTuple2Map),
+                           pinned);
+      __ emit_cond_jump(kUnequal, &load_target, kRef, ref_map.gp(),
+                        pair_map.gp());
 
-      LiftoffRegister current_instance = instance;
+      // Overwrite the tuple's "instance" entry with the current instance.
+      // TODO(jkummerow): Can we figure out a way to guarantee that the
+      // instance field is always precomputed?
+      LiftoffRegister current_instance = temp;
       __ FillInstanceInto(current_instance.gp());
-      LiftoffAssembler::VarState instance_var(kOptRef, current_instance, 0);
-      LiftoffAssembler::VarState callable_var(kOptRef, callable, 0);
-
-      CallRuntimeStub(WasmCode::kWasmAllocatePair,
-                      MakeSig::Returns(kOptRef).Params(kOptRef, kOptRef),
-                      {instance_var, callable_var}, decoder->position());
-      if (instance.gp() != kReturnRegister0) {
-        __ Move(instance.gp(), kReturnRegister0, kPointerKind);
-      }
-
-      // Restore {func_data}, which we saved across the call.
-      __ PopRegisters(saved_regs);
+      __ StoreTaggedPointer(instance.gp(), no_reg,
+                            wasm::ObjectAccess::ToTagged(Tuple2::kValue1Offset),
+                            current_instance, pinned);
+      // Fall through to {load_target}.
+    }
+    // Load the call target.
+    __ bind(&load_target);
+
+#ifdef V8_HEAP_SANDBOX
+    LOAD_INSTANCE_FIELD(temp.gp(), IsolateRoot, kSystemPointerSize, pinned);
+    __ LoadExternalPointerField(
+        target.gp(),
+        FieldOperand(func_data.gp(), WasmFunctionData::kForeignAddressOffset),
+        kForeignForeignAddressTag, temp.gp(),
+        TurboAssembler::IsolateRootLocation::kInScratchRegister);
+#else
+    __ Load(
+        target, func_data.gp(), no_reg,
+        wasm::ObjectAccess::ToTagged(WasmFunctionData::kForeignAddressOffset),
+        kPointerLoadType, pinned);
+#endif
 
-      LiftoffRegister wrapper_code = target;
-      __ LoadTaggedPointer(wrapper_code.gp(), func_data.gp(), no_reg,
-                           wasm::ObjectAccess::ToTagged(
-                               WasmJSFunctionData::kWasmToJsWrapperCodeOffset),
-                           pinned);
-      __ emit_ptrsize_addi(target.gp(), wrapper_code.gp(),
-                           wasm::ObjectAccess::ToTagged(Code::kHeaderSize));
-      // Fall through to {perform_call}.
-    }
+    LiftoffRegister null_address = temp;
+    __ LoadConstant(null_address, WasmValue::ForUintPtr(0));
+    __ emit_cond_jump(kUnequal, &perform_call, kRef, target.gp(),
+                      null_address.gp());
+    // The cached target can only be null for WasmJSFunctions.
+    __ LoadTaggedPointer(target.gp(), func_data.gp(), no_reg,
+                         wasm::ObjectAccess::ToTagged(
+                             WasmJSFunctionData::kWasmToJsWrapperCodeOffset),
+                         pinned);
+    __ emit_ptrsize_addi(target.gp(), target.gp(),
+                         wasm::ObjectAccess::ToTagged(Code::kHeaderSize));
+    // Fall through to {perform_call}.
 
     __ bind(&perform_call);
     // Now the call target is in {target}, and the right instance object
@@ -5818,18 +5766,14 @@ class LiftoffCompiler {
           __ pc_offset(), SourcePosition(decoder->position()), true);
       __ CallIndirect(sig, call_descriptor, target_reg);
 
-      DefineSafepoint();
-      RegisterDebugSideTableEntry(decoder, DebugSideTableBuilder::kDidSpill);
-      EmitLandingPad(decoder);
-      __ FinishCall(sig, call_descriptor);
+      FinishCall(decoder, sig, call_descriptor);
     }
   }
 
   void LoadNullValue(Register null, LiftoffRegList pinned) {
     LOAD_INSTANCE_FIELD(null, IsolateRoot, kSystemPointerSize, pinned);
-    __ LoadTaggedPointer(null, null, no_reg,
-                         IsolateData::root_slot_offset(RootIndex::kNullValue),
-                         pinned);
+    __ LoadFullPointer(null, null,
+                       IsolateData::root_slot_offset(RootIndex::kNullValue));
   }
 
   void LoadExceptionSymbol(Register dst, LiftoffRegList pinned,
@@ -5946,6 +5890,22 @@ class LiftoffCompiler {
                            WASM_STRUCT_TYPE - WASM_ARRAY_TYPE);
   }
 
+  void MaybeOSR() {
+    if (V8_UNLIKELY(for_debugging_)) {
+      __ MaybeOSR();
+    }
+  }
+
+  void FinishCall(FullDecoder* decoder, ValueKindSig* sig,
+                  compiler::CallDescriptor* call_descriptor) {
+    DefineSafepoint();
+    RegisterDebugSideTableEntry(decoder, DebugSideTableBuilder::kDidSpill);
+    int pc_offset = __ pc_offset();
+    MaybeOSR();
+    EmitLandingPad(decoder, pc_offset);
+    __ FinishCall(sig, call_descriptor);
+  }
+
   static constexpr WasmOpcode kNoOutstandingOp = kExprUnreachable;
   static constexpr base::EnumSet<ValueKind> kUnconditionallySupported{
       kI32, kI64, kF32, kF64};
@@ -5993,9 +5953,6 @@ class LiftoffCompiler {
   // at the first breakable opcode in the function (if compiling for debugging).
   bool did_function_entry_break_checks_ = false;
 
-  // Depth of the current try block.
-  int32_t current_catch_ = -1;
-
   struct HandlerInfo {
     MovableLabel handler;
     int pc_offset;
diff --git a/chromium/v8/src/wasm/baseline/liftoff-register.h b/chromium/v8/src/wasm/baseline/liftoff-register.h
index bb27b99dc27..63ac2acf8bc 100644
--- a/chromium/v8/src/wasm/baseline/liftoff-register.h
+++ b/chromium/v8/src/wasm/baseline/liftoff-register.h
@@ -152,11 +152,12 @@ class LiftoffRegister {
                 "chosen type is small enough");
 
  public:
-  explicit LiftoffRegister(Register reg) : LiftoffRegister(reg.code()) {
+  constexpr explicit LiftoffRegister(Register reg)
+      : LiftoffRegister(reg.code()) {
     DCHECK_NE(0, kLiftoffAssemblerGpCacheRegs & reg.bit());
     DCHECK_EQ(reg, gp());
   }
-  explicit LiftoffRegister(DoubleRegister reg)
+  constexpr explicit LiftoffRegister(DoubleRegister reg)
       : LiftoffRegister(kAfterMaxLiftoffGpRegCode + reg.code()) {
     DCHECK_NE(0, kLiftoffAssemblerFpCacheRegs & reg.bit());
     DCHECK_EQ(reg, fp());
@@ -275,22 +276,22 @@ class LiftoffRegister {
     return DoubleRegister::from_code((code_ & kCodeMask) + 1);
   }
 
-  Register gp() const {
+  constexpr Register gp() const {
     DCHECK(is_gp());
     return Register::from_code(code_);
   }
 
-  DoubleRegister fp() const {
+  constexpr DoubleRegister fp() const {
     DCHECK(is_fp());
     return DoubleRegister::from_code(code_ - kAfterMaxLiftoffGpRegCode);
   }
 
-  int liftoff_code() const {
+  constexpr int liftoff_code() const {
     STATIC_ASSERT(sizeof(int) >= sizeof(storage_t));
     return static_cast<int>(code_);
   }
 
-  RegClass reg_class() const {
+  constexpr RegClass reg_class() const {
     return is_fp_pair() ? kFpRegPair
                         : is_gp_pair() ? kGpRegPair : is_gp() ? kGpReg : kFpReg;
   }
@@ -364,7 +365,7 @@ class LiftoffRegList {
     return reg;
   }
 
-  LiftoffRegister clear(LiftoffRegister reg) {
+  constexpr LiftoffRegister clear(LiftoffRegister reg) {
     if (reg.is_pair()) {
       regs_ &= ~(storage_t{1} << reg.low().liftoff_code());
       regs_ &= ~(storage_t{1} << reg.high().liftoff_code());
@@ -373,8 +374,10 @@ class LiftoffRegList {
     }
     return reg;
   }
-  Register clear(Register reg) { return clear(LiftoffRegister{reg}).gp(); }
-  DoubleRegister clear(DoubleRegister reg) {
+  constexpr Register clear(Register reg) {
+    return clear(LiftoffRegister{reg}).gp();
+  }
+  constexpr DoubleRegister clear(DoubleRegister reg) {
     return clear(LiftoffRegister{reg}).fp();
   }
 
diff --git a/chromium/v8/src/wasm/baseline/mips/liftoff-assembler-mips.h b/chromium/v8/src/wasm/baseline/mips/liftoff-assembler-mips.h
index ca715a8a328..58d2d8545cc 100644
--- a/chromium/v8/src/wasm/baseline/mips/liftoff-assembler-mips.h
+++ b/chromium/v8/src/wasm/baseline/mips/liftoff-assembler-mips.h
@@ -433,6 +433,8 @@ void LiftoffAssembler::SpillInstance(Register instance) {
   sw(instance, liftoff::GetInstanceOperand());
 }
 
+void LiftoffAssembler::ResetOSRTarget() {}
+
 void LiftoffAssembler::FillInstanceInto(Register dst) {
   lw(dst, liftoff::GetInstanceOperand());
 }
@@ -468,7 +470,7 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
                                              : MemOperand(dst_addr, offset_imm);
   Sw(src.gp(), dst_op);
 
-  if (skip_write_barrier) return;
+  if (skip_write_barrier || FLAG_disable_write_barriers) return;
 
   // The write barrier.
   Label write_barrier;
@@ -483,8 +485,8 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
   CheckPageFlag(src.gp(), scratch,
                 MemoryChunk::kPointersToHereAreInterestingMask, eq, &exit);
   Addu(scratch, dst_op.rm(), dst_op.offset());
-  CallRecordWriteStub(dst_addr, scratch, EMIT_REMEMBERED_SET, kSaveFPRegs,
-                      wasm::WasmCode::kRecordWrite);
+  CallRecordWriteStub(dst_addr, scratch, RememberedSetAction::kEmit,
+                      SaveFPRegsMode::kSave, wasm::WasmCode::kRecordWrite);
   bind(&exit);
 }
 
@@ -2835,7 +2837,7 @@ void LiftoffAssembler::CallTrapCallbackForTesting() {
 }
 
 void LiftoffAssembler::AssertUnreachable(AbortReason reason) {
-  if (emit_debug_code()) Abort(reason);
+  if (FLAG_debug_code) Abort(reason);
 }
 
 void LiftoffAssembler::PushRegisters(LiftoffRegList regs) {
@@ -2998,6 +3000,8 @@ void LiftoffAssembler::DeallocateStackSlot(uint32_t size) {
   addiu(sp, sp, size);
 }
 
+void LiftoffAssembler::MaybeOSR() {}
+
 void LiftoffStackSlots::Construct(int param_slots) {
   DCHECK_LT(0, slots_.size());
   SortInPushOrder();
diff --git a/chromium/v8/src/wasm/baseline/mips64/liftoff-assembler-mips64.h b/chromium/v8/src/wasm/baseline/mips64/liftoff-assembler-mips64.h
index a5a9f8ce231..15b3b4f7c4d 100644
--- a/chromium/v8/src/wasm/baseline/mips64/liftoff-assembler-mips64.h
+++ b/chromium/v8/src/wasm/baseline/mips64/liftoff-assembler-mips64.h
@@ -418,6 +418,8 @@ void LiftoffAssembler::SpillInstance(Register instance) {
   Sd(instance, liftoff::GetInstanceOperand());
 }
 
+void LiftoffAssembler::ResetOSRTarget() {}
+
 void LiftoffAssembler::FillInstanceInto(Register dst) {
   Ld(dst, liftoff::GetInstanceOperand());
 }
@@ -448,7 +450,7 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
   MemOperand dst_op = liftoff::GetMemOp(this, dst_addr, offset_reg, offset_imm);
   Sd(src.gp(), dst_op);
 
-  if (skip_write_barrier) return;
+  if (skip_write_barrier || FLAG_disable_write_barriers) return;
 
   Label write_barrier;
   Label exit;
@@ -462,8 +464,8 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
                 MemoryChunk::kPointersToHereAreInterestingMask, eq,
                 &exit);
   Daddu(scratch, dst_op.rm(), dst_op.offset());
-  CallRecordWriteStub(dst_addr, scratch, EMIT_REMEMBERED_SET, kSaveFPRegs,
-                      wasm::WasmCode::kRecordWrite);
+  CallRecordWriteStub(dst_addr, scratch, RememberedSetAction::kEmit,
+                      SaveFPRegsMode::kSave, wasm::WasmCode::kRecordWrite);
   bind(&exit);
 }
 
@@ -2994,7 +2996,7 @@ void LiftoffAssembler::CallTrapCallbackForTesting() {
 }
 
 void LiftoffAssembler::AssertUnreachable(AbortReason reason) {
-  if (emit_debug_code()) Abort(reason);
+  if (FLAG_debug_code) Abort(reason);
 }
 
 void LiftoffAssembler::PushRegisters(LiftoffRegList regs) {
@@ -3166,6 +3168,8 @@ void LiftoffAssembler::DeallocateStackSlot(uint32_t size) {
   Daddu(sp, sp, size);
 }
 
+void LiftoffAssembler::MaybeOSR() {}
+
 void LiftoffStackSlots::Construct(int param_slots) {
   DCHECK_LT(0, slots_.size());
   SortInPushOrder();
diff --git a/chromium/v8/src/wasm/baseline/ppc/OWNERS b/chromium/v8/src/wasm/baseline/ppc/OWNERS
deleted file mode 100644
index 02c2cd757c9..00000000000
--- a/chromium/v8/src/wasm/baseline/ppc/OWNERS
+++ /dev/null
@@ -1,5 +0,0 @@
-junyan@redhat.com
-joransiu@ca.ibm.com
-midawson@redhat.com
-mfarazma@redhat.com
-vasili.skurydzin@ibm.com
diff --git a/chromium/v8/src/wasm/baseline/ppc/liftoff-assembler-ppc.h b/chromium/v8/src/wasm/baseline/ppc/liftoff-assembler-ppc.h
index 4e99821a27d..10d574301e6 100644
--- a/chromium/v8/src/wasm/baseline/ppc/liftoff-assembler-ppc.h
+++ b/chromium/v8/src/wasm/baseline/ppc/liftoff-assembler-ppc.h
@@ -45,6 +45,47 @@ inline MemOperand GetHalfStackSlot(int offset, RegPairHalf half) {
   return MemOperand(fp, -kInstanceOffset - offset + half_offset);
 }
 
+inline constexpr Condition ToCondition(LiftoffCondition liftoff_cond) {
+  switch (liftoff_cond) {
+    case kEqual:
+      return eq;
+    case kUnequal:
+      return ne;
+    case kSignedLessThan:
+    case kUnsignedLessThan:
+      return lt;
+    case kSignedLessEqual:
+    case kUnsignedLessEqual:
+      return le;
+    case kSignedGreaterEqual:
+    case kUnsignedGreaterEqual:
+      return ge;
+    case kSignedGreaterThan:
+    case kUnsignedGreaterThan:
+      return gt;
+  }
+}
+
+inline constexpr bool UseSignedOp(LiftoffCondition liftoff_cond) {
+  switch (liftoff_cond) {
+    case kEqual:
+    case kUnequal:
+    case kSignedLessThan:
+    case kSignedLessEqual:
+    case kSignedGreaterThan:
+    case kSignedGreaterEqual:
+      return true;
+    case kUnsignedLessThan:
+    case kUnsignedLessEqual:
+    case kUnsignedGreaterThan:
+    case kUnsignedGreaterEqual:
+      return false;
+    default:
+      UNREACHABLE();
+  }
+  return false;
+}
+
 }  // namespace liftoff
 
 int LiftoffAssembler::PrepareStackFrame() {
@@ -87,7 +128,30 @@ bool LiftoffAssembler::NeedsAlignment(ValueKind kind) {
 
 void LiftoffAssembler::LoadConstant(LiftoffRegister reg, WasmValue value,
                                     RelocInfo::Mode rmode) {
-  bailout(kUnsupportedArchitecture, "LoadConstant");
+  switch (value.type().kind()) {
+    case kI32:
+      mov(reg.gp(), Operand(value.to_i32(), rmode));
+      break;
+    case kI64:
+      mov(reg.gp(), Operand(value.to_i64(), rmode));
+      break;
+    case kF32: {
+      UseScratchRegisterScope temps(this);
+      Register scratch = temps.Acquire();
+      mov(scratch, Operand(value.to_f32_boxed().get_scalar()));
+      MovIntToFloat(reg.fp(), scratch);
+      break;
+    }
+    case kF64: {
+      UseScratchRegisterScope temps(this);
+      Register scratch = temps.Acquire();
+      mov(scratch, Operand(value.to_f32_boxed().get_scalar()));
+      MovInt64ToDouble(reg.fp(), scratch);
+      break;
+    }
+    default:
+      UNREACHABLE();
+  }
 }
 
 void LiftoffAssembler::LoadInstanceFromFrame(Register dst) {
@@ -109,6 +173,8 @@ void LiftoffAssembler::SpillInstance(Register instance) {
   bailout(kUnsupportedArchitecture, "SpillInstance");
 }
 
+void LiftoffAssembler::ResetOSRTarget() {}
+
 void LiftoffAssembler::FillInstanceInto(Register dst) {
   bailout(kUnsupportedArchitecture, "FillInstanceInto");
 }
@@ -524,56 +590,123 @@ void LiftoffAssembler::emit_i64_signextend_i32(LiftoffRegister dst,
   bailout(kUnsupportedArchitecture, "emit_i64_signextend_i32");
 }
 
-void LiftoffAssembler::emit_jump(Label* label) {
-  bailout(kUnsupportedArchitecture, "emit_jump");
-}
+void LiftoffAssembler::emit_jump(Label* label) { b(al, label); }
 
-void LiftoffAssembler::emit_jump(Register target) {
-  bailout(kUnsupportedArchitecture, "emit_jump");
-}
+void LiftoffAssembler::emit_jump(Register target) { Jump(target); }
 
 void LiftoffAssembler::emit_cond_jump(LiftoffCondition liftoff_cond,
                                       Label* label, ValueKind kind,
                                       Register lhs, Register rhs) {
-  bailout(kUnsupportedArchitecture, "emit_cond_jump");
+  Condition cond = liftoff::ToCondition(liftoff_cond);
+  bool use_signed = liftoff::UseSignedOp(liftoff_cond);
+
+  if (rhs != no_reg) {
+    switch (kind) {
+      case kI32:
+        if (use_signed) {
+          cmpw(lhs, rhs);
+        } else {
+          cmplw(lhs, rhs);
+        }
+        break;
+      case kRef:
+      case kOptRef:
+      case kRtt:
+      case kRttWithDepth:
+        DCHECK(liftoff_cond == kEqual || liftoff_cond == kUnequal);
+        V8_FALLTHROUGH;
+      case kI64:
+        if (use_signed) {
+          cmp(lhs, rhs);
+        } else {
+          cmpl(lhs, rhs);
+        }
+        break;
+      default:
+        UNREACHABLE();
+    }
+  } else {
+    DCHECK_EQ(kind, kI32);
+    CHECK(use_signed);
+    cmpwi(lhs, Operand::Zero());
+  }
+
+  b(cond, label);
 }
 
 void LiftoffAssembler::emit_i32_cond_jumpi(LiftoffCondition liftoff_cond,
                                            Label* label, Register lhs,
                                            int32_t imm) {
-  bailout(kUnsupportedArchitecture, "emit_i32_cond_jumpi");
+  Condition cond = liftoff::ToCondition(liftoff_cond);
+  Cmpwi(lhs, Operand(imm), r0);
+  b(cond, label);
 }
 
 void LiftoffAssembler::emit_i32_eqz(Register dst, Register src) {
-  bailout(kUnsupportedArchitecture, "emit_i32_eqz");
+  Label done;
+  cmpwi(src, Operand(0));
+  mov(dst, Operand(1));
+  beq(&done);
+  mov(dst, Operand::Zero());
+  bind(&done);
 }
 
 void LiftoffAssembler::emit_i32_set_cond(LiftoffCondition liftoff_cond,
                                          Register dst, Register lhs,
                                          Register rhs) {
-  bailout(kUnsupportedArchitecture, "emit_i32_set_cond");
+  bool use_signed = liftoff::UseSignedOp(liftoff_cond);
+  if (use_signed) {
+    cmpw(lhs, rhs);
+  } else {
+    cmplw(lhs, rhs);
+  }
+  Label done;
+  mov(dst, Operand(1));
+  b(liftoff::ToCondition(liftoff_cond), &done);
+  mov(dst, Operand::Zero());
+  bind(&done);
 }
 
 void LiftoffAssembler::emit_i64_eqz(Register dst, LiftoffRegister src) {
-  bailout(kUnsupportedArchitecture, "emit_i64_eqz");
+  Label done;
+  cmpi(src.gp(), Operand(0));
+  mov(dst, Operand(1));
+  beq(&done);
+  mov(dst, Operand::Zero());
+  bind(&done);
 }
 
 void LiftoffAssembler::emit_i64_set_cond(LiftoffCondition liftoff_cond,
                                          Register dst, LiftoffRegister lhs,
                                          LiftoffRegister rhs) {
-  bailout(kUnsupportedArchitecture, "emit_i64_set_cond");
+  bool use_signed = liftoff::UseSignedOp(liftoff_cond);
+  if (use_signed) {
+    cmp(lhs.gp(), rhs.gp());
+  } else {
+    cmpl(lhs.gp(), rhs.gp());
+  }
+  Label done;
+  mov(dst, Operand(1));
+  b(liftoff::ToCondition(liftoff_cond), &done);
+  mov(dst, Operand::Zero());
+  bind(&done);
 }
 
 void LiftoffAssembler::emit_f32_set_cond(LiftoffCondition liftoff_cond,
                                          Register dst, DoubleRegister lhs,
                                          DoubleRegister rhs) {
-  bailout(kUnsupportedArchitecture, "emit_f32_set_cond");
+  fcmpu(lhs, rhs);
+  Label done;
+  mov(dst, Operand(1));
+  b(liftoff::ToCondition(liftoff_cond), &done);
+  mov(dst, Operand::Zero());
+  bind(&done);
 }
 
 void LiftoffAssembler::emit_f64_set_cond(LiftoffCondition liftoff_cond,
                                          Register dst, DoubleRegister lhs,
                                          DoubleRegister rhs) {
-  bailout(kUnsupportedArchitecture, "emit_f64_set_cond");
+  emit_f32_set_cond(liftoff_cond, dst, lhs, rhs);
 }
 
 bool LiftoffAssembler::emit_select(LiftoffRegister dst, Register condition,
@@ -1801,6 +1934,8 @@ void LiftoffAssembler::DeallocateStackSlot(uint32_t size) {
   bailout(kUnsupportedArchitecture, "DeallocateStackSlot");
 }
 
+void LiftoffAssembler::MaybeOSR() {}
+
 void LiftoffStackSlots::Construct(int param_slots) {
   asm_->bailout(kUnsupportedArchitecture, "LiftoffStackSlots::Construct");
 }
diff --git a/chromium/v8/src/wasm/baseline/riscv64/liftoff-assembler-riscv64.h b/chromium/v8/src/wasm/baseline/riscv64/liftoff-assembler-riscv64.h
index 47f8ce2125d..3f549a3df63 100644
--- a/chromium/v8/src/wasm/baseline/riscv64/liftoff-assembler-riscv64.h
+++ b/chromium/v8/src/wasm/baseline/riscv64/liftoff-assembler-riscv64.h
@@ -325,9 +325,9 @@ void LiftoffAssembler::PatchPrepareStackFrame(int offset) {
   patching_assembler.Add64(sp, sp, Operand(-frame_size));
 }
 
-void LiftoffAssembler::FinishCode() {}
+void LiftoffAssembler::FinishCode() { ForceConstantPoolEmissionWithoutJump(); }
 
-void LiftoffAssembler::AbortCompilation() {}
+void LiftoffAssembler::AbortCompilation() { AbortedCodeGeneration(); }
 
 // static
 constexpr int LiftoffAssembler::StaticStackFrameSize() {
@@ -382,12 +382,19 @@ void LiftoffAssembler::LoadInstanceFromFrame(Register dst) {
 void LiftoffAssembler::LoadFromInstance(Register dst, Register instance,
                                         int offset, int size) {
   DCHECK_LE(0, offset);
-  DCHECK(size == 4 || size == 8);
   MemOperand src{instance, offset};
-  if (size == 4) {
-    Lw(dst, src);
-  } else {
-    Ld(dst, src);
+  switch (size) {
+    case 1:
+      Lb(dst, MemOperand(src));
+      break;
+    case 4:
+      Lw(dst, MemOperand(src));
+      break;
+    case 8:
+      Ld(dst, MemOperand(src));
+      break;
+    default:
+      UNIMPLEMENTED();
   }
 }
 
@@ -401,6 +408,8 @@ void LiftoffAssembler::SpillInstance(Register instance) {
   Sd(instance, liftoff::GetInstanceOperand());
 }
 
+void LiftoffAssembler::ResetOSRTarget() {}
+
 void LiftoffAssembler::FillInstanceInto(Register dst) {
   Ld(dst, liftoff::GetInstanceOperand());
 }
@@ -414,6 +423,12 @@ void LiftoffAssembler::LoadTaggedPointer(Register dst, Register src_addr,
   Ld(dst, src_op);
 }
 
+void LiftoffAssembler::LoadFullPointer(Register dst, Register src_addr,
+                                       int32_t offset_imm) {
+  MemOperand src_op = liftoff::GetMemOp(this, src_addr, no_reg, offset_imm);
+  Ld(dst, src_op);
+}
+
 void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
                                           Register offset_reg,
                                           int32_t offset_imm,
@@ -425,7 +440,7 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
   MemOperand dst_op = liftoff::GetMemOp(this, dst_addr, offset_reg, offset_imm);
   Sd(src.gp(), dst_op);
 
-  if (skip_write_barrier) return;
+  if (skip_write_barrier || FLAG_disable_write_barriers) return;
 
   Label write_barrier;
   Label exit;
@@ -437,9 +452,9 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
   JumpIfSmi(src.gp(), &exit);
   CheckPageFlag(src.gp(), scratch,
                 MemoryChunk::kPointersToHereAreInterestingMask, eq, &exit);
-  Add64(scratch, dst_addr, offset_imm);
-  CallRecordWriteStub(dst_addr, scratch, EMIT_REMEMBERED_SET, kSaveFPRegs,
-                      wasm::WasmCode::kRecordWrite);
+  Add64(scratch, dst_op.rm(), dst_op.offset());
+  CallRecordWriteStub(dst_addr, scratch, RememberedSetAction::kEmit,
+                      SaveFPRegsMode::kSave, wasm::WasmCode::kRecordWrite);
   bind(&exit);
 }
 
@@ -543,60 +558,297 @@ void LiftoffAssembler::Store(Register dst_addr, Register offset_reg,
   }
 }
 
+namespace liftoff {
+#define __ lasm->
+
+inline Register CalculateActualAddress(LiftoffAssembler* lasm,
+                                       Register addr_reg, Register offset_reg,
+                                       uintptr_t offset_imm,
+                                       Register result_reg) {
+  DCHECK_NE(offset_reg, no_reg);
+  DCHECK_NE(addr_reg, no_reg);
+  __ Add64(result_reg, addr_reg, Operand(offset_reg));
+  if (offset_imm != 0) {
+    __ Add64(result_reg, result_reg, Operand(offset_imm));
+  }
+  return result_reg;
+}
+
+enum class Binop { kAdd, kSub, kAnd, kOr, kXor, kExchange };
+
+inline void AtomicBinop(LiftoffAssembler* lasm, Register dst_addr,
+                        Register offset_reg, uintptr_t offset_imm,
+                        LiftoffRegister value, LiftoffRegister result,
+                        StoreType type, Binop op) {
+  LiftoffRegList pinned =
+      LiftoffRegList::ForRegs(dst_addr, offset_reg, value, result);
+  Register store_result = pinned.set(__ GetUnusedRegister(kGpReg, pinned)).gp();
+
+  // Make sure that {result} is unique.
+  Register result_reg = result.gp();
+  if (result_reg == value.gp() || result_reg == dst_addr ||
+      result_reg == offset_reg) {
+    result_reg = __ GetUnusedRegister(kGpReg, pinned).gp();
+  }
+
+  UseScratchRegisterScope temps(lasm);
+  Register actual_addr = liftoff::CalculateActualAddress(
+      lasm, dst_addr, offset_reg, offset_imm, temps.Acquire());
+
+  // Allocate an additional {temp} register to hold the result that should be
+  // stored to memory. Note that {temp} and {store_result} are not allowed to be
+  // the same register.
+  Register temp = temps.Acquire();
+
+  Label retry;
+  __ bind(&retry);
+  switch (type.value()) {
+    case StoreType::kI64Store8:
+    case StoreType::kI32Store8:
+      __ lbu(result_reg, actual_addr, 0);
+      __ sync();
+      break;
+    case StoreType::kI64Store16:
+    case StoreType::kI32Store16:
+      __ lhu(result_reg, actual_addr, 0);
+      __ sync();
+      break;
+    case StoreType::kI64Store32:
+    case StoreType::kI32Store:
+      __ lr_w(true, false, result_reg, actual_addr);
+      break;
+    case StoreType::kI64Store:
+      __ lr_d(true, false, result_reg, actual_addr);
+      break;
+    default:
+      UNREACHABLE();
+  }
+
+  switch (op) {
+    case Binop::kAdd:
+      __ add(temp, result_reg, value.gp());
+      break;
+    case Binop::kSub:
+      __ sub(temp, result_reg, value.gp());
+      break;
+    case Binop::kAnd:
+      __ and_(temp, result_reg, value.gp());
+      break;
+    case Binop::kOr:
+      __ or_(temp, result_reg, value.gp());
+      break;
+    case Binop::kXor:
+      __ xor_(temp, result_reg, value.gp());
+      break;
+    case Binop::kExchange:
+      __ mv(temp, value.gp());
+      break;
+  }
+  switch (type.value()) {
+    case StoreType::kI64Store8:
+    case StoreType::kI32Store8:
+      __ sync();
+      __ sb(temp, actual_addr, 0);
+      __ sync();
+      __ mv(store_result, zero_reg);
+      break;
+    case StoreType::kI64Store16:
+    case StoreType::kI32Store16:
+      __ sync();
+      __ sh(temp, actual_addr, 0);
+      __ sync();
+      __ mv(store_result, zero_reg);
+      break;
+    case StoreType::kI64Store32:
+    case StoreType::kI32Store:
+      __ sc_w(false, true, store_result, actual_addr, temp);
+      break;
+    case StoreType::kI64Store:
+      __ sc_w(false, true, store_result, actual_addr, temp);
+      break;
+    default:
+      UNREACHABLE();
+  }
+
+  __ bnez(store_result, &retry);
+  if (result_reg != result.gp()) {
+    __ mv(result.gp(), result_reg);
+  }
+}
+
+#undef __
+}  // namespace liftoff
+
 void LiftoffAssembler::AtomicLoad(LiftoffRegister dst, Register src_addr,
                                   Register offset_reg, uintptr_t offset_imm,
                                   LoadType type, LiftoffRegList pinned) {
-  bailout(kAtomics, "AtomicLoad");
+  UseScratchRegisterScope temps(this);
+  Register src_reg = liftoff::CalculateActualAddress(
+      this, src_addr, offset_reg, offset_imm, temps.Acquire());
+  switch (type.value()) {
+    case LoadType::kI32Load8U:
+    case LoadType::kI64Load8U:
+      lbu(dst.gp(), src_reg, 0);
+      sync();
+      return;
+    case LoadType::kI32Load16U:
+    case LoadType::kI64Load16U:
+      lhu(dst.gp(), src_reg, 0);
+      sync();
+      return;
+    case LoadType::kI32Load:
+      lr_w(true, true, dst.gp(), src_reg);
+      return;
+    case LoadType::kI64Load32U:
+      lr_w(true, true, dst.gp(), src_reg);
+      slli(dst.gp(), dst.gp(), 32);
+      srli(dst.gp(), dst.gp(), 32);
+      return;
+    case LoadType::kI64Load:
+      lr_d(true, true, dst.gp(), src_reg);
+      return;
+    default:
+      UNREACHABLE();
+  }
 }
 
 void LiftoffAssembler::AtomicStore(Register dst_addr, Register offset_reg,
                                    uintptr_t offset_imm, LiftoffRegister src,
                                    StoreType type, LiftoffRegList pinned) {
-  bailout(kAtomics, "AtomicStore");
+  UseScratchRegisterScope temps(this);
+  Register dst_reg = liftoff::CalculateActualAddress(
+      this, dst_addr, offset_reg, offset_imm, temps.Acquire());
+  switch (type.value()) {
+    case StoreType::kI64Store8:
+    case StoreType::kI32Store8:
+      sync();
+      sb(src.gp(), dst_reg, 0);
+      sync();
+      return;
+    case StoreType::kI64Store16:
+    case StoreType::kI32Store16:
+      sync();
+      sh(src.gp(), dst_reg, 0);
+      sync();
+      return;
+    case StoreType::kI64Store32:
+    case StoreType::kI32Store:
+      sc_w(true, true, zero_reg, dst_reg, src.gp());
+      return;
+    case StoreType::kI64Store:
+      sc_d(true, true, zero_reg, dst_reg, src.gp());
+      return;
+    default:
+      UNREACHABLE();
+  }
 }
 
 void LiftoffAssembler::AtomicAdd(Register dst_addr, Register offset_reg,
                                  uintptr_t offset_imm, LiftoffRegister value,
                                  LiftoffRegister result, StoreType type) {
-  bailout(kAtomics, "AtomicAdd");
+  liftoff::AtomicBinop(this, dst_addr, offset_reg, offset_imm, value, result,
+                       type, liftoff::Binop::kAdd);
 }
 
 void LiftoffAssembler::AtomicSub(Register dst_addr, Register offset_reg,
                                  uintptr_t offset_imm, LiftoffRegister value,
                                  LiftoffRegister result, StoreType type) {
-  bailout(kAtomics, "AtomicSub");
+  liftoff::AtomicBinop(this, dst_addr, offset_reg, offset_imm, value, result,
+                       type, liftoff::Binop::kSub);
 }
 
 void LiftoffAssembler::AtomicAnd(Register dst_addr, Register offset_reg,
                                  uintptr_t offset_imm, LiftoffRegister value,
                                  LiftoffRegister result, StoreType type) {
-  bailout(kAtomics, "AtomicAnd");
+  liftoff::AtomicBinop(this, dst_addr, offset_reg, offset_imm, value, result,
+                       type, liftoff::Binop::kAnd);
 }
 
 void LiftoffAssembler::AtomicOr(Register dst_addr, Register offset_reg,
                                 uintptr_t offset_imm, LiftoffRegister value,
                                 LiftoffRegister result, StoreType type) {
-  bailout(kAtomics, "AtomicOr");
+  liftoff::AtomicBinop(this, dst_addr, offset_reg, offset_imm, value, result,
+                       type, liftoff::Binop::kOr);
 }
 
 void LiftoffAssembler::AtomicXor(Register dst_addr, Register offset_reg,
                                  uintptr_t offset_imm, LiftoffRegister value,
                                  LiftoffRegister result, StoreType type) {
-  bailout(kAtomics, "AtomicXor");
+  liftoff::AtomicBinop(this, dst_addr, offset_reg, offset_imm, value, result,
+                       type, liftoff::Binop::kXor);
 }
 
 void LiftoffAssembler::AtomicExchange(Register dst_addr, Register offset_reg,
                                       uintptr_t offset_imm,
                                       LiftoffRegister value,
                                       LiftoffRegister result, StoreType type) {
-  bailout(kAtomics, "AtomicExchange");
+  liftoff::AtomicBinop(this, dst_addr, offset_reg, offset_imm, value, result,
+                       type, liftoff::Binop::kExchange);
 }
 
 void LiftoffAssembler::AtomicCompareExchange(
     Register dst_addr, Register offset_reg, uintptr_t offset_imm,
     LiftoffRegister expected, LiftoffRegister new_value, LiftoffRegister result,
     StoreType type) {
-  bailout(kAtomics, "AtomicCompareExchange");
+  LiftoffRegList pinned =
+      LiftoffRegList::ForRegs(dst_addr, offset_reg, expected, new_value);
+
+  Register result_reg = result.gp();
+  if (pinned.has(result)) {
+    result_reg = GetUnusedRegister(kGpReg, pinned).gp();
+  }
+
+  UseScratchRegisterScope temps(this);
+
+  Register actual_addr = liftoff::CalculateActualAddress(
+      this, dst_addr, offset_reg, offset_imm, temps.Acquire());
+
+  Register store_result = temps.Acquire();
+
+  Label retry;
+  Label done;
+  bind(&retry);
+  switch (type.value()) {
+    case StoreType::kI64Store8:
+    case StoreType::kI32Store8:
+      lbu(result_reg, actual_addr, 0);
+      sync();
+      Branch(&done, ne, result.gp(), Operand(expected.gp()));
+      sync();
+      sb(new_value.gp(), actual_addr, 0);
+      sync();
+      mv(store_result, zero_reg);
+      break;
+    case StoreType::kI64Store16:
+    case StoreType::kI32Store16:
+      lhu(result_reg, actual_addr, 0);
+      sync();
+      Branch(&done, ne, result.gp(), Operand(expected.gp()));
+      sync();
+      sh(new_value.gp(), actual_addr, 0);
+      sync();
+      mv(store_result, zero_reg);
+      break;
+    case StoreType::kI64Store32:
+    case StoreType::kI32Store:
+      lr_w(true, true, result_reg, actual_addr);
+      Branch(&done, ne, result.gp(), Operand(expected.gp()));
+      sc_w(true, true, store_result, new_value.gp(), actual_addr);
+      break;
+    case StoreType::kI64Store:
+      lr_d(true, true, result_reg, actual_addr);
+      Branch(&done, ne, result.gp(), Operand(expected.gp()));
+      sc_d(true, true, store_result, new_value.gp(), actual_addr);
+      break;
+    default:
+      UNREACHABLE();
+  }
+  bnez(store_result, &retry);
+  bind(&done);
+
+  if (result_reg != result.gp()) {
+    mv(result.gp(), result_reg);
+  }
 }
 
 void LiftoffAssembler::AtomicFence() { sync(); }
@@ -2412,7 +2664,7 @@ void LiftoffAssembler::CallTrapCallbackForTesting() {
 }
 
 void LiftoffAssembler::AssertUnreachable(AbortReason reason) {
-  if (emit_debug_code()) Abort(reason);
+  if (FLAG_debug_code) Abort(reason);
 }
 
 void LiftoffAssembler::PushRegisters(LiftoffRegList regs) {
@@ -2542,8 +2794,8 @@ void LiftoffAssembler::CallIndirect(const ValueKindSig* sig,
                                     compiler::CallDescriptor* call_descriptor,
                                     Register target) {
   if (target == no_reg) {
-    pop(kScratchReg);
-    Call(kScratchReg);
+    pop(t6);
+    Call(t6);
   } else {
     Call(target);
   }
@@ -2551,8 +2803,8 @@ void LiftoffAssembler::CallIndirect(const ValueKindSig* sig,
 
 void LiftoffAssembler::TailCallIndirect(Register target) {
   if (target == no_reg) {
-    Pop(kScratchReg);
-    Jump(kScratchReg);
+    Pop(t6);
+    Jump(t6);
   } else {
     Jump(target);
   }
@@ -2573,6 +2825,7 @@ void LiftoffAssembler::DeallocateStackSlot(uint32_t size) {
   Add64(sp, sp, Operand(size));
 }
 
+void LiftoffAssembler::MaybeOSR() {}
 
 void LiftoffStackSlots::Construct(int param_slots) {
   DCHECK_LT(0, slots_.size());
diff --git a/chromium/v8/src/wasm/baseline/s390/liftoff-assembler-s390.h b/chromium/v8/src/wasm/baseline/s390/liftoff-assembler-s390.h
index 8560c91553f..4c230ed305d 100644
--- a/chromium/v8/src/wasm/baseline/s390/liftoff-assembler-s390.h
+++ b/chromium/v8/src/wasm/baseline/s390/liftoff-assembler-s390.h
@@ -224,6 +224,8 @@ void LiftoffAssembler::SpillInstance(Register instance) {
   StoreU64(instance, liftoff::GetInstanceOperand());
 }
 
+void LiftoffAssembler::ResetOSRTarget() {}
+
 void LiftoffAssembler::FillInstanceInto(Register dst) {
   LoadU64(dst, liftoff::GetInstanceOperand());
 }
@@ -254,7 +256,7 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
       MemOperand(dst_addr, offset_reg == no_reg ? r0 : offset_reg, offset_imm);
   StoreTaggedField(src.gp(), dst_op);
 
-  if (skip_write_barrier) return;
+  if (skip_write_barrier || FLAG_disable_write_barriers) return;
 
   Label write_barrier;
   Label exit;
@@ -269,8 +271,8 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
   CheckPageFlag(src.gp(), r1, MemoryChunk::kPointersToHereAreInterestingMask,
                 eq, &exit);
   lay(r1, dst_op);
-  CallRecordWriteStub(dst_addr, r1, EMIT_REMEMBERED_SET, kSaveFPRegs,
-                      wasm::WasmCode::kRecordWrite);
+  CallRecordWriteStub(dst_addr, r1, RememberedSetAction::kEmit,
+                      SaveFPRegsMode::kSave, wasm::WasmCode::kRecordWrite);
   bind(&exit);
 }
 
@@ -665,19 +667,253 @@ void LiftoffAssembler::AtomicSub(Register dst_addr, Register offset_reg,
 void LiftoffAssembler::AtomicAnd(Register dst_addr, Register offset_reg,
                                  uintptr_t offset_imm, LiftoffRegister value,
                                  LiftoffRegister result, StoreType type) {
-  bailout(kAtomics, "AtomicAnd");
+  Register tmp1 =
+      GetUnusedRegister(
+          kGpReg, LiftoffRegList::ForRegs(dst_addr, offset_reg, value, result))
+          .gp();
+  Register tmp2 =
+      GetUnusedRegister(kGpReg, LiftoffRegList::ForRegs(dst_addr, offset_reg,
+                                                        value, result, tmp1))
+          .gp();
+
+  lay(ip,
+      MemOperand(dst_addr, offset_reg == no_reg ? r0 : offset_reg, offset_imm));
+
+  switch (type.value()) {
+    case StoreType::kI32Store8:
+    case StoreType::kI64Store8: {
+      Label do_again;
+      bind(&do_again);
+      LoadU8(tmp1, MemOperand(ip));
+      AndP(tmp2, tmp1, value.gp());
+      AtomicCmpExchangeU8(ip, result.gp(), tmp1, tmp2, r0, r1);
+      b(Condition(4), &do_again);
+      LoadU8(result.gp(), result.gp());
+      break;
+    }
+    case StoreType::kI32Store16:
+    case StoreType::kI64Store16: {
+      Label do_again;
+      bind(&do_again);
+      LoadU16(tmp1, MemOperand(ip));
+#ifdef V8_TARGET_BIG_ENDIAN
+      lrvr(tmp2, tmp1);
+      ShiftRightU32(tmp2, tmp2, Operand(16));
+      AndP(tmp2, tmp2, value.gp());
+      lrvr(tmp2, tmp2);
+      ShiftRightU32(tmp2, tmp2, Operand(16));
+#else
+      AndP(tmp2, tmp1, value.gp());
+#endif
+      AtomicCmpExchangeU16(ip, result.gp(), tmp1, tmp2, r0, r1);
+      b(Condition(4), &do_again);
+      LoadU16(result.gp(), result.gp());
+      break;
+    }
+    case StoreType::kI32Store:
+    case StoreType::kI64Store32: {
+      Label do_again;
+      bind(&do_again);
+      LoadU32(tmp1, MemOperand(ip));
+#ifdef V8_TARGET_BIG_ENDIAN
+      lrvr(tmp2, tmp1);
+      AndP(tmp2, tmp2, value.gp());
+      lrvr(tmp2, tmp2);
+#else
+      AndP(tmp2, tmp1, value.gp());
+#endif
+      CmpAndSwap(tmp1, tmp2, MemOperand(ip));
+      b(Condition(4), &do_again);
+      LoadU32(result.gp(), tmp1);
+      break;
+    }
+    case StoreType::kI64Store: {
+      Label do_again;
+      bind(&do_again);
+      LoadU64(tmp1, MemOperand(ip));
+#ifdef V8_TARGET_BIG_ENDIAN
+      lrvgr(tmp2, tmp1);
+      AndP(tmp2, tmp2, value.gp());
+      lrvgr(tmp2, tmp2);
+#else
+      AndP(tmp2, tmp1, value.gp());
+#endif
+      CmpAndSwap64(tmp1, tmp2, MemOperand(ip));
+      b(Condition(4), &do_again);
+      mov(result.gp(), tmp1);
+      break;
+    }
+    default:
+      UNREACHABLE();
+  }
 }
 
 void LiftoffAssembler::AtomicOr(Register dst_addr, Register offset_reg,
                                 uintptr_t offset_imm, LiftoffRegister value,
                                 LiftoffRegister result, StoreType type) {
-  bailout(kAtomics, "AtomicOr");
+  Register tmp1 =
+      GetUnusedRegister(
+          kGpReg, LiftoffRegList::ForRegs(dst_addr, offset_reg, value, result))
+          .gp();
+  Register tmp2 =
+      GetUnusedRegister(kGpReg, LiftoffRegList::ForRegs(dst_addr, offset_reg,
+                                                        value, result, tmp1))
+          .gp();
+
+  lay(ip,
+      MemOperand(dst_addr, offset_reg == no_reg ? r0 : offset_reg, offset_imm));
+
+  switch (type.value()) {
+    case StoreType::kI32Store8:
+    case StoreType::kI64Store8: {
+      Label do_again;
+      bind(&do_again);
+      LoadU8(tmp1, MemOperand(ip));
+      OrP(tmp2, tmp1, value.gp());
+      AtomicCmpExchangeU8(ip, result.gp(), tmp1, tmp2, r0, r1);
+      b(Condition(4), &do_again);
+      LoadU8(result.gp(), result.gp());
+      break;
+    }
+    case StoreType::kI32Store16:
+    case StoreType::kI64Store16: {
+      Label do_again;
+      bind(&do_again);
+      LoadU16(tmp1, MemOperand(ip));
+#ifdef V8_TARGET_BIG_ENDIAN
+      lrvr(tmp2, tmp1);
+      ShiftRightU32(tmp2, tmp2, Operand(16));
+      OrP(tmp2, tmp2, value.gp());
+      lrvr(tmp2, tmp2);
+      ShiftRightU32(tmp2, tmp2, Operand(16));
+#else
+      OrP(tmp2, tmp1, value.gp());
+#endif
+      AtomicCmpExchangeU16(ip, result.gp(), tmp1, tmp2, r0, r1);
+      b(Condition(4), &do_again);
+      LoadU16(result.gp(), result.gp());
+      break;
+    }
+    case StoreType::kI32Store:
+    case StoreType::kI64Store32: {
+      Label do_again;
+      bind(&do_again);
+      LoadU32(tmp1, MemOperand(ip));
+#ifdef V8_TARGET_BIG_ENDIAN
+      lrvr(tmp2, tmp1);
+      OrP(tmp2, tmp2, value.gp());
+      lrvr(tmp2, tmp2);
+#else
+      OrP(tmp2, tmp1, value.gp());
+#endif
+      CmpAndSwap(tmp1, tmp2, MemOperand(ip));
+      b(Condition(4), &do_again);
+      LoadU32(result.gp(), tmp1);
+      break;
+    }
+    case StoreType::kI64Store: {
+      Label do_again;
+      bind(&do_again);
+      LoadU64(tmp1, MemOperand(ip));
+#ifdef V8_TARGET_BIG_ENDIAN
+      lrvgr(tmp2, tmp1);
+      OrP(tmp2, tmp2, value.gp());
+      lrvgr(tmp2, tmp2);
+#else
+      OrP(tmp2, tmp1, value.gp());
+#endif
+      CmpAndSwap64(tmp1, tmp2, MemOperand(ip));
+      b(Condition(4), &do_again);
+      mov(result.gp(), tmp1);
+      break;
+    }
+    default:
+      UNREACHABLE();
+  }
 }
 
 void LiftoffAssembler::AtomicXor(Register dst_addr, Register offset_reg,
                                  uintptr_t offset_imm, LiftoffRegister value,
                                  LiftoffRegister result, StoreType type) {
-  bailout(kAtomics, "AtomicXor");
+  Register tmp1 =
+      GetUnusedRegister(
+          kGpReg, LiftoffRegList::ForRegs(dst_addr, offset_reg, value, result))
+          .gp();
+  Register tmp2 =
+      GetUnusedRegister(kGpReg, LiftoffRegList::ForRegs(dst_addr, offset_reg,
+                                                        value, result, tmp1))
+          .gp();
+
+  lay(ip,
+      MemOperand(dst_addr, offset_reg == no_reg ? r0 : offset_reg, offset_imm));
+
+  switch (type.value()) {
+    case StoreType::kI32Store8:
+    case StoreType::kI64Store8: {
+      Label do_again;
+      bind(&do_again);
+      LoadU8(tmp1, MemOperand(ip));
+      XorP(tmp2, tmp1, value.gp());
+      AtomicCmpExchangeU8(ip, result.gp(), tmp1, tmp2, r0, r1);
+      b(Condition(4), &do_again);
+      LoadU8(result.gp(), result.gp());
+      break;
+    }
+    case StoreType::kI32Store16:
+    case StoreType::kI64Store16: {
+      Label do_again;
+      bind(&do_again);
+      LoadU16(tmp1, MemOperand(ip));
+#ifdef V8_TARGET_BIG_ENDIAN
+      lrvr(tmp2, tmp1);
+      ShiftRightU32(tmp2, tmp2, Operand(16));
+      XorP(tmp2, tmp2, value.gp());
+      lrvr(tmp2, tmp2);
+      ShiftRightU32(tmp2, tmp2, Operand(16));
+#else
+      XorP(tmp2, tmp1, value.gp());
+#endif
+      AtomicCmpExchangeU16(ip, result.gp(), tmp1, tmp2, r0, r1);
+      b(Condition(4), &do_again);
+      LoadU16(result.gp(), result.gp());
+      break;
+    }
+    case StoreType::kI32Store:
+    case StoreType::kI64Store32: {
+      Label do_again;
+      bind(&do_again);
+      LoadU32(tmp1, MemOperand(ip));
+#ifdef V8_TARGET_BIG_ENDIAN
+      lrvr(tmp2, tmp1);
+      XorP(tmp2, tmp2, value.gp());
+      lrvr(tmp2, tmp2);
+#else
+      XorP(tmp2, tmp1, value.gp());
+#endif
+      CmpAndSwap(tmp1, tmp2, MemOperand(ip));
+      b(Condition(4), &do_again);
+      LoadU32(result.gp(), tmp1);
+      break;
+    }
+    case StoreType::kI64Store: {
+      Label do_again;
+      bind(&do_again);
+      LoadU64(tmp1, MemOperand(ip));
+#ifdef V8_TARGET_BIG_ENDIAN
+      lrvgr(tmp2, tmp1);
+      XorP(tmp2, tmp2, value.gp());
+      lrvgr(tmp2, tmp2);
+#else
+      XorP(tmp2, tmp1, value.gp());
+#endif
+      CmpAndSwap64(tmp1, tmp2, MemOperand(ip));
+      b(Condition(4), &do_again);
+      mov(result.gp(), tmp1);
+      break;
+    }
+    default:
+      UNREACHABLE();
+  }
 }
 
 void LiftoffAssembler::AtomicExchange(Register dst_addr, Register offset_reg,
@@ -1162,9 +1398,19 @@ void LiftoffAssembler::FillStackSlotsWithZero(int start, int size) {
     LFR_TO_REG, LFR_TO_REG, USE, , void)                                       \
   V(i64_ctz, CountTrailingZerosU64, LiftoffRegister, LiftoffRegister,          \
     LFR_TO_REG, LFR_TO_REG, USE, , void)                                       \
+  V(f32_ceil, CeilF32, DoubleRegister, DoubleRegister, , , USE, true, bool)    \
+  V(f32_floor, FloorF32, DoubleRegister, DoubleRegister, , , USE, true, bool)  \
+  V(f32_trunc, TruncF32, DoubleRegister, DoubleRegister, , , USE, true, bool)  \
+  V(f32_nearest_int, NearestIntF32, DoubleRegister, DoubleRegister, , , USE,   \
+    true, bool)                                                                \
   V(f32_abs, lpebr, DoubleRegister, DoubleRegister, , , USE, , void)           \
   V(f32_neg, lcebr, DoubleRegister, DoubleRegister, , , USE, , void)           \
   V(f32_sqrt, sqebr, DoubleRegister, DoubleRegister, , , USE, , void)          \
+  V(f64_ceil, CeilF64, DoubleRegister, DoubleRegister, , , USE, true, bool)    \
+  V(f64_floor, FloorF64, DoubleRegister, DoubleRegister, , , USE, true, bool)  \
+  V(f64_trunc, TruncF64, DoubleRegister, DoubleRegister, , , USE, true, bool)  \
+  V(f64_nearest_int, NearestIntF64, DoubleRegister, DoubleRegister, , , USE,   \
+    true, bool)                                                                \
   V(f64_abs, lpdbr, DoubleRegister, DoubleRegister, , , USE, , void)           \
   V(f64_neg, lcdbr, DoubleRegister, DoubleRegister, , , USE, , void)           \
   V(f64_sqrt, sqdbr, DoubleRegister, DoubleRegister, , , USE, , void)
@@ -1185,6 +1431,14 @@ UNOP_LIST(EMIT_UNOP_FUNCTION)
 // V(name, instr, dtype, stype1, stype2, dcast, scast1, scast2, rcast,
 // return_val, return_type)
 #define BINOP_LIST(V)                                                          \
+  V(f32_min, FloatMin, DoubleRegister, DoubleRegister, DoubleRegister, , , ,   \
+    USE, , void)                                                               \
+  V(f32_max, FloatMax, DoubleRegister, DoubleRegister, DoubleRegister, , , ,   \
+    USE, , void)                                                               \
+  V(f64_min, DoubleMin, DoubleRegister, DoubleRegister, DoubleRegister, , , ,  \
+    USE, , void)                                                               \
+  V(f64_max, DoubleMax, DoubleRegister, DoubleRegister, DoubleRegister, , , ,  \
+    USE, , void)                                                               \
   V(f64_add, AddF64, DoubleRegister, DoubleRegister, DoubleRegister, , , ,     \
     USE, , void)                                                               \
   V(f64_sub, SubF64, DoubleRegister, DoubleRegister, DoubleRegister, , , ,     \
@@ -1279,84 +1533,6 @@ BINOP_LIST(EMIT_BINOP_FUNCTION)
 #undef REGISTER_AND_WITH_1F
 #undef LFR_TO_REG
 
-bool LiftoffAssembler::emit_f32_ceil(DoubleRegister dst, DoubleRegister src) {
-  fiebra(ROUND_TOWARD_POS_INF, dst, src);
-  return true;
-}
-
-bool LiftoffAssembler::emit_f32_floor(DoubleRegister dst, DoubleRegister src) {
-  fiebra(ROUND_TOWARD_NEG_INF, dst, src);
-  return true;
-}
-
-bool LiftoffAssembler::emit_f32_trunc(DoubleRegister dst, DoubleRegister src) {
-  fiebra(ROUND_TOWARD_0, dst, src);
-  return true;
-}
-
-bool LiftoffAssembler::emit_f32_nearest_int(DoubleRegister dst,
-                                            DoubleRegister src) {
-  fiebra(ROUND_TO_NEAREST_TO_EVEN, dst, src);
-  return true;
-}
-
-void LiftoffAssembler::emit_f64_min(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  if (CpuFeatures::IsSupported(VECTOR_ENHANCE_FACILITY_1)) {
-    vfmin(dst, lhs, rhs, Condition(1), Condition(8), Condition(3));
-    return;
-  }
-  DoubleMin(dst, lhs, rhs);
-}
-
-void LiftoffAssembler::emit_f32_min(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  if (CpuFeatures::IsSupported(VECTOR_ENHANCE_FACILITY_1)) {
-    vfmin(dst, lhs, rhs, Condition(1), Condition(8), Condition(2));
-    return;
-  }
-  FloatMin(dst, lhs, rhs);
-}
-
-bool LiftoffAssembler::emit_f64_ceil(DoubleRegister dst, DoubleRegister src) {
-  fidbra(ROUND_TOWARD_POS_INF, dst, src);
-  return true;
-}
-
-bool LiftoffAssembler::emit_f64_floor(DoubleRegister dst, DoubleRegister src) {
-  fidbra(ROUND_TOWARD_NEG_INF, dst, src);
-  return true;
-}
-
-bool LiftoffAssembler::emit_f64_trunc(DoubleRegister dst, DoubleRegister src) {
-  fidbra(ROUND_TOWARD_0, dst, src);
-  return true;
-}
-
-bool LiftoffAssembler::emit_f64_nearest_int(DoubleRegister dst,
-                                            DoubleRegister src) {
-  fidbra(ROUND_TO_NEAREST_TO_EVEN, dst, src);
-  return true;
-}
-
-void LiftoffAssembler::emit_f64_max(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  if (CpuFeatures::IsSupported(VECTOR_ENHANCE_FACILITY_1)) {
-    vfmax(dst, lhs, rhs, Condition(1), Condition(8), Condition(3));
-    return;
-  }
-  DoubleMax(dst, lhs, rhs);
-}
-
-void LiftoffAssembler::emit_f32_max(DoubleRegister dst, DoubleRegister lhs,
-                                    DoubleRegister rhs) {
-  if (CpuFeatures::IsSupported(VECTOR_ENHANCE_FACILITY_1)) {
-    vfmax(dst, lhs, rhs, Condition(1), Condition(8), Condition(2));
-    return;
-  }
-  FloatMax(dst, lhs, rhs);
-}
-
 void LiftoffAssembler::emit_i32_divs(Register dst, Register lhs, Register rhs,
                                      Label* trap_div_by_zero,
                                      Label* trap_div_unrepresentable) {
@@ -1890,7 +2066,9 @@ bool LiftoffAssembler::emit_select(LiftoffRegister dst, Register condition,
 
 void LiftoffAssembler::emit_smi_check(Register obj, Label* target,
                                       SmiCheckMode mode) {
-  bailout(kUnsupportedArchitecture, "emit_smi_check");
+  TestIfSmi(obj);
+  Condition condition = mode == kJumpOnSmi ? eq : ne;
+  b(condition, target);  // branch if SMI
 }
 
 void LiftoffAssembler::LoadTransform(LiftoffRegister dst, Register src_addr,
@@ -3207,6 +3385,8 @@ void LiftoffAssembler::DeallocateStackSlot(uint32_t size) {
   lay(sp, MemOperand(sp, size));
 }
 
+void LiftoffAssembler::MaybeOSR() {}
+
 void LiftoffStackSlots::Construct(int param_slots) {
   DCHECK_LT(0, slots_.size());
   SortInPushOrder();
diff --git a/chromium/v8/src/wasm/baseline/x64/liftoff-assembler-x64.h b/chromium/v8/src/wasm/baseline/x64/liftoff-assembler-x64.h
index e8a57bafca1..3da9656b42c 100644
--- a/chromium/v8/src/wasm/baseline/x64/liftoff-assembler-x64.h
+++ b/chromium/v8/src/wasm/baseline/x64/liftoff-assembler-x64.h
@@ -70,6 +70,8 @@ inline Operand GetStackSlot(int offset) { return Operand(rbp, -offset); }
 // TODO(clemensb): Make this a constexpr variable once Operand is constexpr.
 inline Operand GetInstanceOperand() { return GetStackSlot(kInstanceOffset); }
 
+inline Operand GetOSRTargetSlot() { return GetStackSlot(kOSRTargetOffset); }
+
 inline Operand GetMemOp(LiftoffAssembler* assm, Register addr, Register offset,
                         uintptr_t offset_imm) {
   if (is_uint31(offset_imm)) {
@@ -79,7 +81,7 @@ inline Operand GetMemOp(LiftoffAssembler* assm, Register addr, Register offset,
   }
   // Offset immediate does not fit in 31 bits.
   Register scratch = kScratchRegister;
-  assm->Set(scratch, offset_imm);
+  assm->TurboAssembler::Move(scratch, offset_imm);
   if (offset != no_reg) assm->addq(scratch, offset);
   return Operand(addr, scratch, times_1, 0);
 }
@@ -249,7 +251,7 @@ void LiftoffAssembler::AbortCompilation() {}
 
 // static
 constexpr int LiftoffAssembler::StaticStackFrameSize() {
-  return liftoff::kInstanceOffset;
+  return kOSRTargetOffset;
 }
 
 int LiftoffAssembler::SlotSizeForType(ValueKind kind) {
@@ -272,7 +274,7 @@ void LiftoffAssembler::LoadConstant(LiftoffRegister reg, WasmValue value,
       break;
     case kI64:
       if (RelocInfo::IsNone(rmode)) {
-        TurboAssembler::Set(reg.gp(), value.to_i64());
+        TurboAssembler::Move(reg.gp(), value.to_i64());
       } else {
         movq(reg.gp(), Immediate64(value.to_i64(), rmode));
       }
@@ -322,6 +324,10 @@ void LiftoffAssembler::SpillInstance(Register instance) {
   movq(liftoff::GetInstanceOperand(), instance);
 }
 
+void LiftoffAssembler::ResetOSRTarget() {
+  movq(liftoff::GetOSRTargetSlot(), Immediate(0));
+}
+
 void LiftoffAssembler::FillInstanceInto(Register dst) {
   movq(dst, liftoff::GetInstanceOperand());
 }
@@ -331,7 +337,7 @@ void LiftoffAssembler::LoadTaggedPointer(Register dst, Register src_addr,
                                          int32_t offset_imm,
                                          LiftoffRegList pinned) {
   DCHECK_GE(offset_imm, 0);
-  if (emit_debug_code() && offset_reg != no_reg) {
+  if (FLAG_debug_code && offset_reg != no_reg) {
     AssertZeroExtended(offset_reg);
   }
   Operand src_op = liftoff::GetMemOp(this, src_addr, offset_reg,
@@ -357,7 +363,7 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
                                      static_cast<uint32_t>(offset_imm));
   StoreTaggedField(dst_op, src.gp());
 
-  if (skip_write_barrier) return;
+  if (skip_write_barrier || FLAG_disable_write_barriers) return;
 
   Register scratch = pinned.set(GetUnusedRegister(kGpReg, pinned)).gp();
   Label write_barrier;
@@ -375,8 +381,8 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
                 MemoryChunk::kPointersToHereAreInterestingMask, zero, &exit,
                 Label::kNear);
   leaq(scratch, dst_op);
-  CallRecordWriteStub(dst_addr, scratch, EMIT_REMEMBERED_SET, kSaveFPRegs,
-                      wasm::WasmCode::kRecordWrite);
+  CallRecordWriteStub(dst_addr, scratch, RememberedSetAction::kEmit,
+                      SaveFPRegsMode::kSave, wasm::WasmCode::kRecordWrite);
   bind(&exit);
 }
 
@@ -1253,7 +1259,7 @@ void LiftoffAssembler::emit_i64_add(LiftoffRegister dst, LiftoffRegister lhs,
 void LiftoffAssembler::emit_i64_addi(LiftoffRegister dst, LiftoffRegister lhs,
                                      int64_t imm) {
   if (!is_int32(imm)) {
-    TurboAssembler::Set(kScratchRegister, imm);
+    TurboAssembler::Move(kScratchRegister, imm);
     if (lhs.gp() == dst.gp()) {
       addq(dst.gp(), kScratchRegister);
     } else {
@@ -2534,7 +2540,7 @@ void LiftoffAssembler::emit_i64x2_splat(LiftoffRegister dst,
 
 void LiftoffAssembler::emit_f32x4_splat(LiftoffRegister dst,
                                         LiftoffRegister src) {
-  Shufps(dst.fp(), src.fp(), src.fp(), 0);
+  F32x4Splat(dst.fp(), src.fp());
 }
 
 void LiftoffAssembler::emit_f64x2_splat(LiftoffRegister dst,
@@ -2846,13 +2852,7 @@ void LiftoffAssembler::emit_s128_const(LiftoffRegister dst,
 }
 
 void LiftoffAssembler::emit_s128_not(LiftoffRegister dst, LiftoffRegister src) {
-  if (dst.fp() != src.fp()) {
-    Pcmpeqd(dst.fp(), dst.fp());
-    Pxor(dst.fp(), src.fp());
-  } else {
-    Pcmpeqd(kScratchDoubleReg, kScratchDoubleReg);
-    Pxor(dst.fp(), kScratchDoubleReg);
-  }
+  S128Not(dst.fp(), src.fp(), kScratchDoubleReg);
 }
 
 void LiftoffAssembler::emit_s128_and(LiftoffRegister dst, LiftoffRegister lhs,
@@ -3429,15 +3429,7 @@ void LiftoffAssembler::emit_i32x4_extmul_high_i16x8_u(LiftoffRegister dst,
 
 void LiftoffAssembler::emit_i64x2_neg(LiftoffRegister dst,
                                       LiftoffRegister src) {
-  DoubleRegister reg = dst.fp() == src.fp() ? kScratchDoubleReg : dst.fp();
-  Pxor(reg, reg);
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    vpsubq(dst.fp(), reg, src.fp());
-  } else {
-    psubq(reg, src.fp());
-    if (dst.fp() != reg) movaps(dst.fp(), reg);
-  }
+  I64x2Neg(dst.fp(), src.fp(), kScratchDoubleReg);
 }
 
 void LiftoffAssembler::emit_i64x2_alltrue(LiftoffRegister dst,
@@ -3504,13 +3496,13 @@ void LiftoffAssembler::emit_i64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
   Movaps(tmp1.fp(), lhs.fp());
   Movaps(tmp2.fp(), rhs.fp());
   // Multiply high dword of each qword of left with right.
-  Psrlq(tmp1.fp(), 32);
+  Psrlq(tmp1.fp(), byte{32});
   Pmuludq(tmp1.fp(), rhs.fp());
   // Multiply high dword of each qword of right with left.
-  Psrlq(tmp2.fp(), 32);
+  Psrlq(tmp2.fp(), byte{32});
   Pmuludq(tmp2.fp(), lhs.fp());
   Paddq(tmp2.fp(), tmp1.fp());
-  Psllq(tmp2.fp(), 32);
+  Psllq(tmp2.fp(), byte{32});
   liftoff::EmitSimdCommutativeBinOp<&Assembler::vpmuludq, &Assembler::pmuludq>(
       this, dst, lhs, rhs);
   Paddq(dst.fp(), tmp2.fp());
@@ -3586,11 +3578,11 @@ void LiftoffAssembler::emit_f32x4_neg(LiftoffRegister dst,
                                       LiftoffRegister src) {
   if (dst.fp() == src.fp()) {
     Pcmpeqd(kScratchDoubleReg, kScratchDoubleReg);
-    Pslld(kScratchDoubleReg, static_cast<byte>(31));
+    Pslld(kScratchDoubleReg, byte{31});
     Xorps(dst.fp(), kScratchDoubleReg);
   } else {
     Pcmpeqd(dst.fp(), dst.fp());
-    Pslld(dst.fp(), static_cast<byte>(31));
+    Pslld(dst.fp(), byte{31});
     Xorps(dst.fp(), src.fp());
   }
 }
@@ -3674,7 +3666,7 @@ void LiftoffAssembler::emit_f32x4_min(LiftoffRegister dst, LiftoffRegister lhs,
   // propagate -0's and NaNs, which may be non-canonical.
   Orps(kScratchDoubleReg, dst.fp());
   // Canonicalize NaNs by quieting and clearing the payload.
-  Cmpps(dst.fp(), kScratchDoubleReg, int8_t{3});
+  Cmpunordps(dst.fp(), kScratchDoubleReg);
   Orps(kScratchDoubleReg, dst.fp());
   Psrld(dst.fp(), byte{10});
   Andnps(dst.fp(), kScratchDoubleReg);
@@ -3706,7 +3698,7 @@ void LiftoffAssembler::emit_f32x4_max(LiftoffRegister dst, LiftoffRegister lhs,
   // Propagate sign discrepancy and (subtle) quiet NaNs.
   Subps(kScratchDoubleReg, dst.fp());
   // Canonicalize NaNs by clearing the payload. Sign is non-deterministic.
-  Cmpps(dst.fp(), kScratchDoubleReg, int8_t{3});
+  Cmpunordps(dst.fp(), kScratchDoubleReg);
   Psrld(dst.fp(), byte{10});
   Andnps(dst.fp(), kScratchDoubleReg);
 }
@@ -3729,11 +3721,11 @@ void LiftoffAssembler::emit_f64x2_abs(LiftoffRegister dst,
                                       LiftoffRegister src) {
   if (dst.fp() == src.fp()) {
     Pcmpeqd(kScratchDoubleReg, kScratchDoubleReg);
-    Psrlq(kScratchDoubleReg, static_cast<byte>(1));
+    Psrlq(kScratchDoubleReg, byte{1});
     Andpd(dst.fp(), kScratchDoubleReg);
   } else {
     Pcmpeqd(dst.fp(), dst.fp());
-    Psrlq(dst.fp(), static_cast<byte>(1));
+    Psrlq(dst.fp(), byte{1});
     Andpd(dst.fp(), src.fp());
   }
 }
@@ -3810,61 +3802,12 @@ void LiftoffAssembler::emit_f64x2_div(LiftoffRegister dst, LiftoffRegister lhs,
 
 void LiftoffAssembler::emit_f64x2_min(LiftoffRegister dst, LiftoffRegister lhs,
                                       LiftoffRegister rhs) {
-  // The minpd instruction doesn't propagate NaNs and +0's in its first
-  // operand. Perform minpd in both orders, merge the results, and adjust.
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    vminpd(kScratchDoubleReg, lhs.fp(), rhs.fp());
-    vminpd(dst.fp(), rhs.fp(), lhs.fp());
-  } else if (dst.fp() == lhs.fp() || dst.fp() == rhs.fp()) {
-    XMMRegister src = dst.fp() == lhs.fp() ? rhs.fp() : lhs.fp();
-    movaps(kScratchDoubleReg, src);
-    minpd(kScratchDoubleReg, dst.fp());
-    minpd(dst.fp(), src);
-  } else {
-    movaps(kScratchDoubleReg, lhs.fp());
-    minpd(kScratchDoubleReg, rhs.fp());
-    movaps(dst.fp(), rhs.fp());
-    minpd(dst.fp(), lhs.fp());
-  }
-  // propagate -0's and NaNs, which may be non-canonical.
-  Orpd(kScratchDoubleReg, dst.fp());
-  // Canonicalize NaNs by quieting and clearing the payload.
-  Cmppd(dst.fp(), kScratchDoubleReg, int8_t{3});
-  Orpd(kScratchDoubleReg, dst.fp());
-  Psrlq(dst.fp(), 13);
-  Andnpd(dst.fp(), kScratchDoubleReg);
+  F64x2Min(dst.fp(), lhs.fp(), rhs.fp(), kScratchDoubleReg);
 }
 
 void LiftoffAssembler::emit_f64x2_max(LiftoffRegister dst, LiftoffRegister lhs,
                                       LiftoffRegister rhs) {
-  // The maxpd instruction doesn't propagate NaNs and +0's in its first
-  // operand. Perform maxpd in both orders, merge the results, and adjust.
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    vmaxpd(kScratchDoubleReg, lhs.fp(), rhs.fp());
-    vmaxpd(dst.fp(), rhs.fp(), lhs.fp());
-  } else if (dst.fp() == lhs.fp() || dst.fp() == rhs.fp()) {
-    XMMRegister src = dst.fp() == lhs.fp() ? rhs.fp() : lhs.fp();
-    movaps(kScratchDoubleReg, src);
-    maxpd(kScratchDoubleReg, dst.fp());
-    maxpd(dst.fp(), src);
-  } else {
-    movaps(kScratchDoubleReg, lhs.fp());
-    maxpd(kScratchDoubleReg, rhs.fp());
-    movaps(dst.fp(), rhs.fp());
-    maxpd(dst.fp(), lhs.fp());
-  }
-  // Find discrepancies.
-  Xorpd(dst.fp(), kScratchDoubleReg);
-  // Propagate NaNs, which may be non-canonical.
-  Orpd(kScratchDoubleReg, dst.fp());
-  // Propagate sign discrepancy and (subtle) quiet NaNs.
-  Subpd(kScratchDoubleReg, dst.fp());
-  // Canonicalize NaNs by clearing the payload. Sign is non-deterministic.
-  Cmppd(dst.fp(), kScratchDoubleReg, int8_t{3});
-  Psrlq(dst.fp(), 13);
-  Andnpd(dst.fp(), kScratchDoubleReg);
+  F64x2Max(dst.fp(), lhs.fp(), rhs.fp(), kScratchDoubleReg);
 }
 
 void LiftoffAssembler::emit_f64x2_pmin(LiftoffRegister dst, LiftoffRegister lhs,
@@ -4148,20 +4091,13 @@ void LiftoffAssembler::emit_i64x2_extract_lane(LiftoffRegister dst,
 void LiftoffAssembler::emit_f32x4_extract_lane(LiftoffRegister dst,
                                                LiftoffRegister lhs,
                                                uint8_t imm_lane_idx) {
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    vshufps(dst.fp(), lhs.fp(), lhs.fp(), imm_lane_idx);
-  } else {
-    if (dst.fp() != lhs.fp()) movaps(dst.fp(), lhs.fp());
-    if (imm_lane_idx != 0) shufps(dst.fp(), dst.fp(), imm_lane_idx);
-  }
+  F32x4ExtractLane(dst.fp(), lhs.fp(), imm_lane_idx);
 }
 
 void LiftoffAssembler::emit_f64x2_extract_lane(LiftoffRegister dst,
                                                LiftoffRegister lhs,
                                                uint8_t imm_lane_idx) {
-  Pextrq(kScratchRegister, lhs.fp(), static_cast<int8_t>(imm_lane_idx));
-  Movq(dst.fp(), kScratchRegister);
+  F64x2ExtractLane(dst.fp(), lhs.fp(), imm_lane_idx);
 }
 
 void LiftoffAssembler::emit_i8x16_replace_lane(LiftoffRegister dst,
@@ -4237,22 +4173,7 @@ void LiftoffAssembler::emit_f64x2_replace_lane(LiftoffRegister dst,
                                                LiftoffRegister src1,
                                                LiftoffRegister src2,
                                                uint8_t imm_lane_idx) {
-  if (CpuFeatures::IsSupported(AVX)) {
-    CpuFeatureScope scope(this, AVX);
-    if (imm_lane_idx == 0) {
-      vpblendw(dst.fp(), src1.fp(), src2.fp(), 0b00001111);
-    } else {
-      vmovlhps(dst.fp(), src1.fp(), src2.fp());
-    }
-  } else {
-    CpuFeatureScope scope(this, SSE4_1);
-    if (dst.fp() != src1.fp()) movaps(dst.fp(), src1.fp());
-    if (imm_lane_idx == 0) {
-      pblendw(dst.fp(), src2.fp(), 0b00001111);
-    } else {
-      movlhps(dst.fp(), src2.fp());
-    }
-  }
+  F64x2ReplaceLane(dst.fp(), src1.fp(), src2.fp(), imm_lane_idx);
 }
 
 void LiftoffAssembler::StackCheck(Label* ool_code, Register limit_address) {
@@ -4424,6 +4345,12 @@ void LiftoffAssembler::DeallocateStackSlot(uint32_t size) {
   addq(rsp, Immediate(size));
 }
 
+void LiftoffAssembler::MaybeOSR() {
+  cmpq(liftoff::GetOSRTargetSlot(), Immediate(0));
+  j(not_equal, static_cast<Address>(WasmCode::kWasmOnStackReplace),
+    RelocInfo::WASM_STUB_CALL);
+}
+
 void LiftoffStackSlots::Construct(int param_slots) {
   DCHECK_LT(0, slots_.size());
   SortInPushOrder();
diff --git a/chromium/v8/src/wasm/branch-hint-map.h b/chromium/v8/src/wasm/branch-hint-map.h
new file mode 100644
index 00000000000..242bbecbce4
--- /dev/null
+++ b/chromium/v8/src/wasm/branch-hint-map.h
@@ -0,0 +1,46 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_WASM_BRANCH_HINT_MAP_H_
+#define V8_WASM_BRANCH_HINT_MAP_H_
+
+#include <unordered_map>
+
+#include "src/base/macros.h"
+
+namespace v8 {
+namespace internal {
+
+namespace wasm {
+
+enum class WasmBranchHint : uint8_t {
+  kNoHint = 0,
+  kUnlikely = 1,
+  kLikely = 2,
+};
+
+class V8_EXPORT_PRIVATE BranchHintMap {
+ public:
+  void insert(uint32_t offset, WasmBranchHint hint) {
+    map_.emplace(offset, hint);
+  }
+  WasmBranchHint GetHintFor(uint32_t offset) const {
+    auto it = map_.find(offset);
+    if (it == map_.end()) {
+      return WasmBranchHint::kNoHint;
+    }
+    return it->second;
+  }
+
+ private:
+  std::unordered_map<uint32_t, WasmBranchHint> map_;
+};
+
+using BranchHintInfo = std::unordered_map<uint32_t, BranchHintMap>;
+
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_WASM_BRANCH_HINT_MAP_H_
diff --git a/chromium/v8/src/wasm/c-api.cc b/chromium/v8/src/wasm/c-api.cc
index 3af5afaee37..72d2e073055 100644
--- a/chromium/v8/src/wasm/c-api.cc
+++ b/chromium/v8/src/wasm/c-api.cc
@@ -257,7 +257,6 @@ void Engine::operator delete(void* p) { ::operator delete(p); }
 auto Engine::make(own<Config>&& config) -> own<Engine> {
   i::FLAG_expose_gc = true;
   i::FLAG_experimental_wasm_reftypes = true;
-  i::FLAG_experimental_wasm_mv = true;
   auto engine = new (std::nothrow) EngineImpl;
   if (!engine) return own<Engine>();
   engine->platform = v8::platform::NewDefaultPlatform();
@@ -456,8 +455,7 @@ struct FuncTypeImpl : ExternTypeImpl {
   ownvec<ValType> params;
   ownvec<ValType> results;
 
-  FuncTypeImpl(ownvec<ValType>& params,   // NOLINT(runtime/references)
-               ownvec<ValType>& results)  // NOLINT(runtime/references)
+  FuncTypeImpl(ownvec<ValType>& params, ownvec<ValType>& results)
       : ExternTypeImpl(EXTERN_FUNC),
         params(std::move(params)),
         results(std::move(results)) {}
@@ -508,8 +506,7 @@ struct GlobalTypeImpl : ExternTypeImpl {
   own<ValType> content;
   Mutability mutability;
 
-  GlobalTypeImpl(own<ValType>& content,  // NOLINT(runtime/references)
-                 Mutability mutability)
+  GlobalTypeImpl(own<ValType>& content, Mutability mutability)
       : ExternTypeImpl(EXTERN_GLOBAL),
         content(std::move(content)),
         mutability(mutability) {}
@@ -561,8 +558,7 @@ struct TableTypeImpl : ExternTypeImpl {
   own<ValType> element;
   Limits limits;
 
-  TableTypeImpl(own<ValType>& element,  // NOLINT(runtime/references)
-                Limits limits)
+  TableTypeImpl(own<ValType>& element, Limits limits)
       : ExternTypeImpl(EXTERN_TABLE),
         element(std::move(element)),
         limits(limits) {}
@@ -653,9 +649,7 @@ struct ImportTypeImpl {
   Name name;
   own<ExternType> type;
 
-  ImportTypeImpl(Name& module,           // NOLINT(runtime/references)
-                 Name& name,             // NOLINT(runtime/references)
-                 own<ExternType>& type)  // NOLINT(runtime/references)
+  ImportTypeImpl(Name& module, Name& name, own<ExternType>& type)
       : module(std::move(module)),
         name(std::move(name)),
         type(std::move(type)) {}
@@ -696,8 +690,7 @@ struct ExportTypeImpl {
   Name name;
   own<ExternType> type;
 
-  ExportTypeImpl(Name& name,             // NOLINT(runtime/references)
-                 own<ExternType>& type)  // NOLINT(runtime/references)
+  ExportTypeImpl(Name& name, own<ExternType>& type)
       : name(std::move(name)), type(std::move(type)) {}
 };
 
@@ -1357,26 +1350,6 @@ i::Handle<i::Object> WasmRefToV8(i::Isolate* isolate, const Ref* ref) {
   return impl(ref)->v8_object();
 }
 
-i::Handle<i::Object> CallTargetForCaching(i::Isolate* isolate,
-                                          i::Address real_call_target) {
-  if (i::kTaggedSize == i::kInt32Size) {
-    return isolate->factory()->NewForeign(real_call_target);
-  } else {
-    // 64-bit uncompressed platform.
-    return i::handle(i::Smi((real_call_target << i::kSmiTagSize) | i::kSmiTag),
-                     isolate);
-  }
-}
-
-i::Address CallTargetFromCache(i::Object cached_call_target) {
-  if (i::kTaggedSize == i::kInt32Size) {
-    return i::Foreign::cast(cached_call_target).foreign_address();
-  } else {
-    // 64-bit uncompressed platform.
-    return cached_call_target.ptr() >> i::kSmiTagSize;
-  }
-}
-
 void PrepareFunctionData(i::Isolate* isolate,
                          i::Handle<i::WasmExportedFunctionData> function_data,
                          const i::wasm::FunctionSig* sig,
@@ -1390,12 +1363,6 @@ void PrepareFunctionData(i::Isolate* isolate,
   // Compute packed args size.
   function_data->set_packed_args_size(
       i::wasm::CWasmArgumentsPacker::TotalSize(sig));
-  // Get call target (function table offset), and wrap it as a cacheable object
-  // (pseudo-Smi or Foreign, depending on platform).
-  i::Handle<i::Object> call_target = CallTargetForCaching(
-      isolate,
-      function_data->instance().GetCallTarget(function_data->function_index()));
-  function_data->set_wasm_call_target(*call_target);
 }
 
 void PushArgs(const i::wasm::FunctionSig* sig, const Val args[],
@@ -1532,8 +1499,7 @@ auto Func::call(const Val args[], Val results[]) const -> own<Trap> {
   PrepareFunctionData(isolate, function_data, sig, instance->module());
   i::Handle<i::Code> wrapper_code = i::Handle<i::Code>(
       i::Code::cast(function_data->c_wrapper_code()), isolate);
-  i::Address call_target =
-      CallTargetFromCache(function_data->wasm_call_target());
+  i::Address call_target = function_data->foreign_address();
 
   i::wasm::CWasmArgumentsPacker packer(function_data->packed_args_size());
   PushArgs(sig, args, &packer, store);
diff --git a/chromium/v8/src/wasm/compilation-environment.h b/chromium/v8/src/wasm/compilation-environment.h
index 987180c83f6..a10190f70b0 100644
--- a/chromium/v8/src/wasm/compilation-environment.h
+++ b/chromium/v8/src/wasm/compilation-environment.h
@@ -38,8 +38,6 @@ enum RuntimeExceptionSupport : bool {
 
 enum UseTrapHandler : bool { kUseTrapHandler = true, kNoTrapHandler = false };
 
-enum LowerSimd : bool { kLowerSimd = true, kNoLowerSimd = false };
-
 // The {CompilationEnv} encapsulates the module data that is used during
 // compilation. CompilationEnvs are shareable across multiple compilations.
 struct CompilationEnv {
@@ -66,8 +64,6 @@ struct CompilationEnv {
   // Features enabled for this compilation.
   const WasmFeatures enabled_features;
 
-  const LowerSimd lower_simd;
-
   // We assume that memories of size >= half of the virtual address space
   // cannot be allocated (see https://crbug.com/1201340).
   static constexpr uint32_t kMaxMemoryPagesAtRuntime = std::min(
@@ -77,8 +73,7 @@ struct CompilationEnv {
   constexpr CompilationEnv(const WasmModule* module,
                            UseTrapHandler use_trap_handler,
                            RuntimeExceptionSupport runtime_exception_support,
-                           const WasmFeatures& enabled_features,
-                           LowerSimd lower_simd = kNoLowerSimd)
+                           const WasmFeatures& enabled_features)
       : module(module),
         use_trap_handler(use_trap_handler),
         runtime_exception_support(runtime_exception_support),
@@ -92,8 +87,7 @@ struct CompilationEnv {
                      module && module->has_maximum_pages ? module->maximum_pages
                                                          : max_mem_pages()) *
             uint64_t{kWasmPageSize})),
-        enabled_features(enabled_features),
-        lower_simd(lower_simd) {}
+        enabled_features(enabled_features) {}
 };
 
 // The wire bytes are either owned by the StreamingDecoder, or (after streaming)
@@ -127,6 +121,8 @@ class V8_EXPORT_PRIVATE CompilationState {
 
   void CancelCompilation();
 
+  void CancelInitialCompilation();
+
   void SetError();
 
   void SetWireBytesStorage(std::shared_ptr<WireBytesStorage>);
diff --git a/chromium/v8/src/wasm/function-body-decoder-impl.h b/chromium/v8/src/wasm/function-body-decoder-impl.h
index d37f7186818..94c34c402d5 100644
--- a/chromium/v8/src/wasm/function-body-decoder-impl.h
+++ b/chromium/v8/src/wasm/function-body-decoder-impl.h
@@ -539,13 +539,6 @@ struct BlockTypeImmediate {
       type = value_type_reader::read_value_type<validate>(decoder, pc, &length,
                                                           module, enabled);
     } else {
-      if (!VALIDATE(enabled.has_mv())) {
-        DecodeError<validate>(decoder, pc,
-                              "invalid block type %" PRId64
-                              ", enable with --experimental-wasm-mv",
-                              block_type);
-        return;
-      }
       type = kWasmBottom;
       sig_index = static_cast<uint32_t>(block_type);
     }
@@ -582,18 +575,6 @@ struct BranchDepthImmediate {
 };
 
 template <Decoder::ValidateFlag validate>
-struct BranchOnExceptionImmediate {
-  BranchDepthImmediate<validate> depth;
-  ExceptionIndexImmediate<validate> index;
-  uint32_t length = 0;
-  inline BranchOnExceptionImmediate(Decoder* decoder, const byte* pc)
-      : depth(BranchDepthImmediate<validate>(decoder, pc)),
-        index(ExceptionIndexImmediate<validate>(decoder, pc + depth.length)) {
-    length = depth.length + index.length;
-  }
-};
-
-template <Decoder::ValidateFlag validate>
 struct FunctionIndexImmediate {
   uint32_t index = 0;
   uint32_t length = 1;
@@ -965,8 +946,10 @@ enum Reachability : uint8_t {
 template <typename Value, Decoder::ValidateFlag validate>
 struct ControlBase : public PcForErrors<validate> {
   ControlKind kind = kControlBlock;
-  uint32_t locals_count = 0;
-  uint32_t stack_depth = 0;  // stack height at the beginning of the construct.
+  uint32_t locals_count = 0;  // Additional locals introduced in this 'let'.
+  uint32_t stack_depth = 0;   // Stack height at the beginning of the construct.
+  int32_t previous_catch = -1;  // Depth of the innermost catch containing this
+                                // 'try'.
   Reachability reachability = kReachable;
 
   // Values merged into the start or end of this control construct.
@@ -1037,7 +1020,6 @@ struct ControlBase : public PcForErrors<validate> {
   F(If, const Value& cond, Control* if_block)                                  \
   F(FallThruTo, Control* c)                                                    \
   F(PopControl, Control* block)                                                \
-  F(EndControl, Control* block)                                                \
   /* Instructions: */                                                          \
   F(UnOp, WasmOpcode opcode, const Value& value, Value* result)                \
   F(BinOp, WasmOpcode opcode, const Value& lhs, const Value& rhs,              \
@@ -1099,6 +1081,7 @@ struct ControlBase : public PcForErrors<validate> {
   F(ReturnCallIndirect, const Value& index,                                    \
     const CallIndirectImmediate<validate>& imm, const Value args[])            \
   F(BrOnNull, const Value& ref_object, uint32_t depth)                         \
+  F(BrOnNonNull, const Value& ref_object, uint32_t depth)                      \
   F(SimdOp, WasmOpcode opcode, Vector<Value> args, Value* result)              \
   F(SimdLaneOp, WasmOpcode opcode, const SimdLaneImmediate<validate>& imm,     \
     const Vector<Value> inputs, Value* result)                                 \
@@ -1184,9 +1167,7 @@ class WasmDecoder : public Decoder {
         module_(module),
         enabled_(enabled),
         detected_(detected),
-        sig_(sig) {
-    if (sig_ && sig_->return_count() > 1) detected_->Add(kFeature_mv);
-  }
+        sig_(sig) {}
 
   Zone* zone() const { return local_types_.get_allocator().zone(); }
 
@@ -1433,9 +1414,6 @@ class WasmDecoder : public Decoder {
   inline bool Complete(CallFunctionImmediate<validate>& imm) {
     if (!VALIDATE(imm.index < module_->functions.size())) return false;
     imm.sig = module_->functions[imm.index].sig;
-    if (imm.sig->return_count() > 1) {
-      this->detected_->Add(kFeature_mv);
-    }
     return true;
   }
 
@@ -1450,13 +1428,11 @@ class WasmDecoder : public Decoder {
   inline bool Complete(CallIndirectImmediate<validate>& imm) {
     if (!VALIDATE(module_->has_signature(imm.sig_index))) return false;
     imm.sig = module_->signature(imm.sig_index);
-    if (imm.sig->return_count() > 1) {
-      this->detected_->Add(kFeature_mv);
-    }
     return true;
   }
 
   inline bool Validate(const byte* pc, CallIndirectImmediate<validate>& imm) {
+    // Validate immediate table index.
     if (!VALIDATE(imm.table_index < module_->tables.size())) {
       DecodeError(pc, "call_indirect: table index immediate out of bounds");
       return false;
@@ -1468,10 +1444,13 @@ class WasmDecoder : public Decoder {
           imm.table_index);
       return false;
     }
+
+    // Validate immediate signature index.
     if (!Complete(imm)) {
       DecodeError(pc, "invalid signature index: #%u", imm.sig_index);
       return false;
     }
+
     // Check that the dynamic signature for this call is a subtype of the static
     // type of the table the function is defined in.
     ValueType immediate_type = ValueType::Ref(imm.sig_index, kNonNullable);
@@ -1480,6 +1459,7 @@ class WasmDecoder : public Decoder {
                   "call_indirect: Immediate signature #%u is not a subtype of "
                   "immediate table #%u",
                   imm.sig_index, imm.table_index);
+      return false;
     }
     return true;
   }
@@ -1503,13 +1483,6 @@ class WasmDecoder : public Decoder {
     return checkAvailable(imm.table_count);
   }
 
-  inline bool Validate(const byte* pc,
-                       BranchOnExceptionImmediate<validate>& imm,
-                       size_t control_size) {
-    return Validate(pc, imm.depth, control_size) &&
-           Validate(pc + imm.depth.length, imm.index);
-  }
-
   inline bool Validate(const byte* pc, WasmOpcode opcode,
                        SimdLaneImmediate<validate>& imm) {
     uint8_t num_lanes = 0;
@@ -1573,9 +1546,6 @@ class WasmDecoder : public Decoder {
     if (imm.type != kWasmBottom) return true;
     if (!VALIDATE(module_->has_signature(imm.sig_index))) return false;
     imm.sig = module_->signature(imm.sig_index);
-    if (imm.sig->return_count() > 1) {
-      this->detected_->Add(kFeature_mv);
-    }
     return true;
   }
 
@@ -1709,6 +1679,7 @@ class WasmDecoder : public Decoder {
       case kExprBr:
       case kExprBrIf:
       case kExprBrOnNull:
+      case kExprBrOnNonNull:
       case kExprDelegate: {
         BranchDepthImmediate<validate> imm(decoder, pc + 1);
         return 1 + imm.length;
@@ -2043,6 +2014,7 @@ class WasmDecoder : public Decoder {
       case kExprBrIf:
       case kExprBrTable:
       case kExprIf:
+      case kExprBrOnNonNull:
         return {1, 0};
       case kExprLocalGet:
       case kExprGlobalGet:
@@ -2183,12 +2155,22 @@ MemoryAccessImmediate<validate>::MemoryAccessImmediate(
     : MemoryAccessImmediate(decoder, pc, max_alignment,
                             decoder->module_->is_memory64) {}
 
+// Only call this in contexts where {current_code_reachable_and_ok_} is known to
+// hold.
+#define CALL_INTERFACE(name, ...)                         \
+  do {                                                    \
+    DCHECK(!control_.empty());                            \
+    DCHECK(current_code_reachable_and_ok_);               \
+    DCHECK_EQ(current_code_reachable_and_ok_,             \
+              this->ok() && control_.back().reachable()); \
+    interface_.name(this, ##__VA_ARGS__);                 \
+  } while (false)
 #define CALL_INTERFACE_IF_OK_AND_REACHABLE(name, ...)     \
   do {                                                    \
     DCHECK(!control_.empty());                            \
     DCHECK_EQ(current_code_reachable_and_ok_,             \
               this->ok() && control_.back().reachable()); \
-    if (current_code_reachable_and_ok_) {                 \
+    if (V8_LIKELY(current_code_reachable_and_ok_)) {      \
       interface_.name(this, ##__VA_ARGS__);               \
     }                                                     \
   } while (false)
@@ -2289,33 +2271,39 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     return WasmOpcodes::OpcodeName(opcode);
   }
 
-  inline WasmCodePosition position() {
+  WasmCodePosition position() const {
     int offset = static_cast<int>(this->pc_ - this->start_);
     DCHECK_EQ(this->pc_ - this->start_, offset);  // overflows cannot happen
     return offset;
   }
 
-  inline uint32_t control_depth() const {
+  uint32_t control_depth() const {
     return static_cast<uint32_t>(control_.size());
   }
 
-  inline Control* control_at(uint32_t depth) {
+  Control* control_at(uint32_t depth) {
     DCHECK_GT(control_.size(), depth);
     return &control_.back() - depth;
   }
 
-  inline uint32_t stack_size() const {
+  uint32_t stack_size() const {
     DCHECK_GE(stack_end_, stack_);
     DCHECK_GE(kMaxUInt32, stack_end_ - stack_);
     return static_cast<uint32_t>(stack_end_ - stack_);
   }
 
-  inline Value* stack_value(uint32_t depth) {
+  Value* stack_value(uint32_t depth) const {
     DCHECK_LT(0, depth);
     DCHECK_GE(stack_size(), depth);
     return stack_end_ - depth;
   }
 
+  int32_t current_catch() const { return current_catch_; }
+
+  uint32_t control_depth_of_current_catch() const {
+    return control_depth() - 1 - current_catch();
+  }
+
   void SetSucceedingCodeDynamicallyUnreachable() {
     Control* current = &control_.back();
     if (current->reachable()) {
@@ -2324,7 +2312,12 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     }
   }
 
+  inline uint32_t pc_relative_offset() const {
+    return this->pc_offset() - first_instruction_offset;
+  }
+
  private:
+  uint32_t first_instruction_offset = 0;
   Interface interface_;
 
   // The value stack, stored as individual pointers for maximum performance.
@@ -2340,6 +2333,9 @@ class WasmFullDecoder : public WasmDecoder<validate> {
   // a cache for {ok() && control_.back().reachable()}).
   bool current_code_reachable_and_ok_ = true;
 
+  // Depth of the current try block.
+  int32_t current_catch_ = -1;
+
   static Value UnreachableValue(const uint8_t* pc) {
     return Value{pc, kWasmBottom};
   }
@@ -2519,6 +2515,8 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     ArgVector args = PeekArgs(imm.sig);
     Control* try_block = PushControl(kControlTry, 0, args.length());
     SetBlockType(try_block, imm, args.begin());
+    try_block->previous_catch = current_catch_;
+    current_catch_ = static_cast<int>(control_depth() - 1);
     CALL_INTERFACE_IF_OK_AND_REACHABLE(Try, try_block);
     DropArgs(imm.sig);
     PushMergeValues(try_block, &try_block->start_merge);
@@ -2543,7 +2541,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
       this->DecodeError("catch after unwind for try");
       return 0;
     }
-    FallThruTo(c);
+    FallThrough();
     c->kind = kControlTryCatch;
     // TODO(jkummerow): Consider moving the stack manipulation after the
     // INTERFACE call for consistency.
@@ -2556,6 +2554,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
       Push(CreateValue(sig->GetParam(i)));
     }
     Vector<Value> values(stack_ + c->stack_depth, sig->parameter_count());
+    current_catch_ = c->previous_catch;  // Pop try scope.
     CALL_INTERFACE_IF_OK_AND_PARENT_REACHABLE(CatchException, imm, c, values);
     current_code_reachable_and_ok_ = this->ok() && c->reachable();
     return 1 + imm.length;
@@ -2584,11 +2583,11 @@ class WasmFullDecoder : public WasmDecoder<validate> {
           "cannot delegate inside the catch handler of the target");
       return 0;
     }
-    FallThruTo(c);
+    FallThrough();
     CALL_INTERFACE_IF_OK_AND_PARENT_REACHABLE(Delegate, imm.depth + 1, c);
-    current_code_reachable_and_ok_ = this->ok() && control_.back().reachable();
+    current_catch_ = c->previous_catch;
     EndControl();
-    PopControl(c);
+    PopControl();
     return 1 + imm.length;
   }
 
@@ -2608,9 +2607,10 @@ class WasmFullDecoder : public WasmDecoder<validate> {
       this->error("cannot have catch-all after unwind");
       return 0;
     }
-    FallThruTo(c);
+    FallThrough();
     c->kind = kControlTryCatchAll;
     c->reachability = control_at(1)->innerReachability();
+    current_catch_ = c->previous_catch;  // Pop try scope.
     CALL_INTERFACE_IF_OK_AND_PARENT_REACHABLE(CatchAll, c);
     stack_end_ = stack_ + c->stack_depth;
     current_code_reachable_and_ok_ = this->ok() && c->reachable();
@@ -2630,9 +2630,10 @@ class WasmFullDecoder : public WasmDecoder<validate> {
       this->error("catch, catch-all or unwind already present for try");
       return 0;
     }
-    FallThruTo(c);
+    FallThrough();
     c->kind = kControlTryUnwind;
     c->reachability = control_at(1)->innerReachability();
+    current_catch_ = c->previous_catch;  // Pop try scope.
     CALL_INTERFACE_IF_OK_AND_PARENT_REACHABLE(CatchAll, c);
     stack_end_ = stack_ + c->stack_depth;
     current_code_reachable_and_ok_ = this->ok() && c->reachable();
@@ -2645,33 +2646,69 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     if (!this->Validate(this->pc_ + 1, imm, control_.size())) return 0;
     Value ref_object = Peek(0, 0);
     Control* c = control_at(imm.depth);
-    TypeCheckBranchResult check_result = TypeCheckBranch(c, true, 1);
+    if (!VALIDATE(TypeCheckBranch<true>(c, 1))) return 0;
     switch (ref_object.type.kind()) {
       case kBottom:
         // We are in a polymorphic stack. Leave the stack as it is.
-        DCHECK(check_result != kReachableBranch);
+        DCHECK(!current_code_reachable_and_ok_);
         break;
       case kRef:
         // For a non-nullable value, we won't take the branch, and can leave
         // the stack as it is.
         break;
       case kOptRef: {
-        if (V8_LIKELY(check_result == kReachableBranch)) {
-          CALL_INTERFACE_IF_OK_AND_REACHABLE(BrOnNull, ref_object, imm.depth);
           Value result = CreateValue(
               ValueType::Ref(ref_object.type.heap_type(), kNonNullable));
           // The result of br_on_null has the same value as the argument (but a
           // non-nullable type).
-          CALL_INTERFACE_IF_OK_AND_REACHABLE(Forward, ref_object, &result);
-          c->br_merge()->reached = true;
+          if (V8_LIKELY(current_code_reachable_and_ok_)) {
+            CALL_INTERFACE(BrOnNull, ref_object, imm.depth);
+            CALL_INTERFACE(Forward, ref_object, &result);
+            c->br_merge()->reached = true;
+          }
+          // In unreachable code, we still have to push a value of the correct
+          // type onto the stack.
           Drop(ref_object);
           Push(result);
-        } else {
-          // Even in non-reachable code, we need to push a value of the correct
-          // type to the stack.
-          Drop(ref_object);
-          Push(CreateValue(
-              ValueType::Ref(ref_object.type.heap_type(), kNonNullable)));
+        break;
+      }
+      default:
+        PopTypeError(0, ref_object, "object reference");
+        return 0;
+    }
+    return 1 + imm.length;
+  }
+
+  DECODE(BrOnNonNull) {
+    CHECK_PROTOTYPE_OPCODE(gc);
+    BranchDepthImmediate<validate> imm(this, this->pc_ + 1);
+    if (!this->Validate(this->pc_ + 1, imm, control_.size())) return 0;
+    Value ref_object = Peek(0, 0, kWasmAnyRef);
+    Drop(ref_object);
+    // Typechecking the branch and creating the branch merges requires the
+    // non-null value on the stack, so we push it temporarily.
+    Value result = CreateValue(ref_object.type.AsNonNull());
+    Push(result);
+    Control* c = control_at(imm.depth);
+    if (!VALIDATE(TypeCheckBranch<true>(c, 0))) return 0;
+    switch (ref_object.type.kind()) {
+      case kBottom:
+        // We are in unreachable code. Do nothing.
+        DCHECK(!current_code_reachable_and_ok_);
+        break;
+      case kRef:
+        // For a non-nullable value, we always take the branch.
+        if (V8_LIKELY(current_code_reachable_and_ok_)) {
+          CALL_INTERFACE(Forward, ref_object, stack_value(1));
+          CALL_INTERFACE(BrOrRet, imm.depth, 0);
+          c->br_merge()->reached = true;
+        }
+        break;
+      case kOptRef: {
+        if (V8_LIKELY(current_code_reachable_and_ok_)) {
+          CALL_INTERFACE(Forward, ref_object, stack_value(1));
+          CALL_INTERFACE(BrOnNonNull, ref_object, imm.depth);
+          c->br_merge()->reached = true;
         }
         break;
       }
@@ -2679,6 +2716,8 @@ class WasmFullDecoder : public WasmDecoder<validate> {
         PopTypeError(0, ref_object, "object reference");
         return 0;
     }
+    // If we stay in the branch, {ref_object} is null. Drop it from the stack.
+    Drop(result);
     return 1 + imm.length;
   }
 
@@ -2751,7 +2790,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
       this->DecodeError("else already present for if");
       return 0;
     }
-    if (!TypeCheckFallThru()) return 0;
+    if (!VALIDATE(TypeCheckFallThru())) return 0;
     c->kind = kControlIfElse;
     CALL_INTERFACE_IF_OK_AND_PARENT_REACHABLE(Else, c);
     if (c->reachable()) c->end_merge.reached = true;
@@ -2764,27 +2803,24 @@ class WasmFullDecoder : public WasmDecoder<validate> {
   DECODE(End) {
     DCHECK(!control_.empty());
     Control* c = &control_.back();
-    if (!VALIDATE(!c->is_incomplete_try())) {
-      this->DecodeError("missing catch or catch-all in try");
-      return 0;
-    }
-    if (c->is_onearmed_if()) {
-      if (!VALIDATE(c->end_merge.arity == c->start_merge.arity)) {
-        this->DecodeError(
-            c->pc(), "start-arity and end-arity of one-armed if must match");
-        return 0;
-      }
-      if (!TypeCheckOneArmedIf(c)) return 0;
-    }
     if (c->is_try_catch()) {
       // Emulate catch-all + re-throw.
-      FallThruTo(c);
+      FallThrough();
       c->reachability = control_at(1)->innerReachability();
       CALL_INTERFACE_IF_OK_AND_PARENT_REACHABLE(CatchAll, c);
       current_code_reachable_and_ok_ =
           this->ok() && control_.back().reachable();
       CALL_INTERFACE_IF_OK_AND_REACHABLE(Rethrow, c);
       EndControl();
+      PopControl();
+      return 1;
+    }
+    if (!VALIDATE(!c->is_incomplete_try())) {
+      this->DecodeError("missing catch or catch-all in try");
+      return 0;
+    }
+    if (c->is_onearmed_if()) {
+      if (!VALIDATE(TypeCheckOneArmedIf(c))) return 0;
     }
     if (c->is_try_unwind()) {
       // Unwind implicitly rethrows at the end.
@@ -2798,7 +2834,6 @@ class WasmFullDecoder : public WasmDecoder<validate> {
                                this->local_types_.begin() + c->locals_count);
       this->num_locals_ -= c->locals_count;
     }
-    if (!TypeCheckFallThru()) return 0;
 
     if (control_.size() == 1) {
       // If at the last (implicit) control, check we are at end.
@@ -2809,11 +2844,13 @@ class WasmFullDecoder : public WasmDecoder<validate> {
       // The result of the block is the return value.
       trace_msg->Append("\n" TRACE_INST_FORMAT, startrel(this->pc_),
                         "(implicit) return");
-      DoReturn();
+      DoReturn<kStrictCounting, kFallthroughMerge>();
       control_.clear();
       return 1;
     }
-    PopControl(c);
+
+    if (!VALIDATE(TypeCheckFallThru())) return 0;
+    PopControl();
     return 1;
   }
 
@@ -2853,9 +2890,9 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     BranchDepthImmediate<validate> imm(this, this->pc_ + 1);
     if (!this->Validate(this->pc_ + 1, imm, control_.size())) return 0;
     Control* c = control_at(imm.depth);
-    TypeCheckBranchResult check_result = TypeCheckBranch(c, false, 0);
-    if (V8_LIKELY(check_result == kReachableBranch)) {
-      CALL_INTERFACE_IF_OK_AND_REACHABLE(BrOrRet, imm.depth, 0);
+    if (!VALIDATE(TypeCheckBranch<false>(c, 0))) return 0;
+    if (V8_LIKELY(current_code_reachable_and_ok_)) {
+      CALL_INTERFACE(BrOrRet, imm.depth, 0);
       c->br_merge()->reached = true;
     }
     EndControl();
@@ -2867,9 +2904,9 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     if (!this->Validate(this->pc_ + 1, imm, control_.size())) return 0;
     Value cond = Peek(0, 0, kWasmI32);
     Control* c = control_at(imm.depth);
-    TypeCheckBranchResult check_result = TypeCheckBranch(c, true, 1);
-    if (V8_LIKELY(check_result == kReachableBranch)) {
-      CALL_INTERFACE_IF_OK_AND_REACHABLE(BrIf, cond, imm.depth);
+    if (!VALIDATE(TypeCheckBranch<true>(c, 1))) return 0;
+    if (V8_LIKELY(current_code_reachable_and_ok_)) {
+      CALL_INTERFACE(BrIf, cond, imm.depth);
       c->br_merge()->reached = true;
     }
     Drop(cond);
@@ -2887,40 +2924,38 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     // all branch targets as reachable after the {CALL_INTERFACE} call.
     std::vector<bool> br_targets(control_.size());
 
-    // The result types of the br_table instruction. We have to check the
-    // stack against these types. Only needed during validation.
-    std::vector<ValueType> result_types;
+    uint32_t arity = 0;
 
     while (iterator.has_next()) {
       const uint32_t index = iterator.cur_index();
       const byte* pos = iterator.pc();
-      uint32_t target = iterator.next();
-      if (!VALIDATE(ValidateBrTableTarget(target, pos, index))) return 0;
+      const uint32_t target = iterator.next();
+      if (!VALIDATE(target < control_depth())) {
+        this->DecodeError(pos, "invalid branch depth: %u", target);
+        return 0;
+      }
       // Avoid redundant branch target checks.
       if (br_targets[target]) continue;
       br_targets[target] = true;
 
       if (validate) {
         if (index == 0) {
-          // With the first branch target, initialize the result types.
-          result_types = InitializeBrTableResultTypes(target);
-        } else if (!UpdateBrTableResultTypes(&result_types, target, pos,
-                                             index)) {
+          arity = control_at(target)->br_merge()->arity;
+        } else if (!VALIDATE(control_at(target)->br_merge()->arity == arity)) {
+          this->DecodeError(
+              pos, "br_table: label arity inconsistent with previous arity %d",
+              arity);
           return 0;
         }
+        if (!VALIDATE(TypeCheckBranch<false>(control_at(target), 1))) return 0;
       }
     }
 
-    if (!VALIDATE(TypeCheckBrTable(result_types, 1))) return 0;
-
-    DCHECK(this->ok());
-
-    if (current_code_reachable_and_ok_) {
-      CALL_INTERFACE_IF_OK_AND_REACHABLE(BrTable, imm, key);
+    if (V8_LIKELY(current_code_reachable_and_ok_)) {
+      CALL_INTERFACE(BrTable, imm, key);
 
-      for (int i = 0, e = control_depth(); i < e; ++i) {
-        if (!br_targets[i]) continue;
-        control_at(i)->br_merge()->reached = true;
+      for (uint32_t i = 0; i < control_depth(); ++i) {
+        control_at(i)->br_merge()->reached |= br_targets[i];
       }
     }
     Drop(key);
@@ -2929,22 +2964,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
   }
 
   DECODE(Return) {
-    if (V8_LIKELY(current_code_reachable_and_ok_)) {
-      if (!VALIDATE(TypeCheckReturn())) return 0;
-      DoReturn();
-    } else {
-      // We inspect all return values from the stack to check their type.
-      // Since we deal with unreachable code, we do not have to keep the
-      // values.
-      int num_returns = static_cast<int>(this->sig_->return_count());
-      for (int i = num_returns - 1, depth = 0; i >= 0; --i, ++depth) {
-        Peek(depth, i, this->sig_->GetReturn(i));
-      }
-      Drop(num_returns);
-    }
-
-    EndControl();
-    return 1;
+    return DoReturn<kNonStrictCounting, kReturnMerge>() ? 1 : 0;
   }
 
   DECODE(Unreachable) {
@@ -3409,6 +3429,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     DECODE_IMPL(CatchAll);
     DECODE_IMPL(Unwind);
     DECODE_IMPL(BrOnNull);
+    DECODE_IMPL(BrOnNonNull);
     DECODE_IMPL(Let);
     DECODE_IMPL(Loop);
     DECODE_IMPL(If);
@@ -3490,6 +3511,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
       CALL_INTERFACE_IF_OK_AND_REACHABLE(StartFunctionBody, c);
     }
 
+    first_instruction_offset = this->pc_offset();
     // Decode the function body.
     while (this->pc_ < this->end_) {
       // Most operations only grow the stack by at least one element (unary and
@@ -3526,7 +3548,6 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     Control* current = &control_.back();
     DCHECK_LE(stack_ + current->stack_depth, stack_end_);
     stack_end_ = stack_ + current->stack_depth;
-    CALL_INTERFACE_IF_OK_AND_REACHABLE(EndControl, current);
     current->reachability = kUnreachable;
     current_code_reachable_and_ok_ = false;
   }
@@ -3642,11 +3663,12 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     return &control_.back();
   }
 
-  void PopControl(Control* c) {
+  void PopControl() {
     // This cannot be the outermost control block.
     DCHECK_LT(1, control_.size());
+    Control* c = &control_.back();
+    DCHECK_LE(stack_ + c->stack_depth, stack_end_);
 
-    DCHECK_EQ(c, &control_.back());
     CALL_INTERFACE_IF_OK_AND_PARENT_REACHABLE(PopControl, c);
 
     // A loop just leaves the values on the stack.
@@ -3658,7 +3680,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     // If the parent block was reachable before, but the popped control does not
     // return to here, this block becomes "spec only reachable".
     if (!parent_reached) SetSucceedingCodeDynamicallyUnreachable();
-    current_code_reachable_and_ok_ = control_.back().reachable();
+    current_code_reachable_and_ok_ = this->ok() && control_.back().reachable();
   }
 
   int DecodeLoadMem(LoadType type, int prefix_len = 1) {
@@ -3739,92 +3761,6 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     return prefix_len + imm.length;
   }
 
-  bool ValidateBrTableTarget(uint32_t target, const byte* pos, int index) {
-    if (!VALIDATE(target < this->control_.size())) {
-      this->DecodeError(pos, "improper branch in br_table target %u (depth %u)",
-                        index, target);
-      return false;
-    }
-    return true;
-  }
-
-  std::vector<ValueType> InitializeBrTableResultTypes(uint32_t target) {
-    Merge<Value>* merge = control_at(target)->br_merge();
-    int br_arity = merge->arity;
-    std::vector<ValueType> result(br_arity);
-    for (int i = 0; i < br_arity; ++i) {
-      result[i] = (*merge)[i].type;
-    }
-    return result;
-  }
-
-  bool UpdateBrTableResultTypes(std::vector<ValueType>* result_types,
-                                uint32_t target, const byte* pos, int index) {
-    Merge<Value>* merge = control_at(target)->br_merge();
-    int br_arity = merge->arity;
-    // First we check if the arities match.
-    if (!VALIDATE(br_arity == static_cast<int>(result_types->size()))) {
-      this->DecodeError(pos,
-                        "inconsistent arity in br_table target %u (previous "
-                        "was %zu, this one is %u)",
-                        index, result_types->size(), br_arity);
-      return false;
-    }
-
-    for (int i = 0; i < br_arity; ++i) {
-      if (this->enabled_.has_reftypes()) {
-        // The expected type is the biggest common sub type of all targets.
-        (*result_types)[i] =
-            CommonSubtype((*result_types)[i], (*merge)[i].type, this->module_);
-      } else {
-        // All target must have the same signature.
-        if (!VALIDATE((*result_types)[i] == (*merge)[i].type)) {
-          this->DecodeError(pos,
-                            "inconsistent type in br_table target %u (previous "
-                            "was %s, this one is %s)",
-                            index, (*result_types)[i].name().c_str(),
-                            (*merge)[i].type.name().c_str());
-          return false;
-        }
-      }
-    }
-    return true;
-  }
-
-  bool TypeCheckBrTable(const std::vector<ValueType>& result_types,
-                        uint32_t drop_values) {
-    int br_arity = static_cast<int>(result_types.size());
-    if (V8_LIKELY(!control_.back().unreachable())) {
-      int available =
-          static_cast<int>(stack_size()) - control_.back().stack_depth;
-      available -= std::min(available, static_cast<int>(drop_values));
-      // There have to be enough values on the stack.
-      if (!VALIDATE(available >= br_arity)) {
-        this->DecodeError(
-            "expected %u elements on the stack for branch to @%d, found %u",
-            br_arity, startrel(control_.back().pc()), available);
-        return false;
-      }
-      Value* stack_values = stack_end_ - br_arity - drop_values;
-      // Type-check the topmost br_arity values on the stack.
-      for (int i = 0; i < br_arity; ++i) {
-        Value& val = stack_values[i];
-        if (!VALIDATE(IsSubtypeOf(val.type, result_types[i], this->module_))) {
-          this->DecodeError("type error in merge[%u] (expected %s, got %s)", i,
-                            result_types[i].name().c_str(),
-                            val.type.name().c_str());
-          return false;
-        }
-      }
-    } else {  // !control_.back().reachable()
-      // Type-check the values on the stack.
-      for (int i = 0; i < br_arity; ++i) {
-        Peek(i + drop_values, i + 1, result_types[i]);
-      }
-    }
-    return this->ok();
-  }
-
   uint32_t SimdConstOp(uint32_t opcode_length) {
     Simd128Immediate<validate> imm(this, this->pc_ + opcode_length);
     Value result = CreateValue(kWasmS128);
@@ -4377,7 +4313,6 @@ class WasmFullDecoder : public WasmDecoder<validate> {
               CALL_INTERFACE_IF_OK_AND_REACHABLE(Drop);
               CALL_INTERFACE_IF_OK_AND_REACHABLE(AssertNull, obj, &value);
             } else {
-              // TODO(manoskouk): Change the trap label.
               CALL_INTERFACE_IF_OK_AND_REACHABLE(Trap,
                                                  TrapReason::kTrapIllegalCast);
               EndControl();
@@ -4426,23 +4361,21 @@ class WasmFullDecoder : public WasmDecoder<validate> {
                 ? kWasmBottom
                 : ValueType::Ref(rtt.type.ref_index(), kNonNullable));
         Push(result_on_branch);
-        TypeCheckBranchResult check_result = TypeCheckBranch(c, true, 0);
-        if (V8_LIKELY(check_result == kReachableBranch)) {
-          // This logic ensures that code generation can assume that functions
-          // can only be cast to function types, and data objects to data types.
-          if (V8_LIKELY(ObjectRelatedWithRtt(obj, rtt))) {
-            // The {value_on_branch} parameter we pass to the interface must
-            // be pointer-identical to the object on the stack, so we can't
-            // reuse {result_on_branch} which was passed-by-value to {Push}.
-            Value* value_on_branch = stack_value(1);
-            CALL_INTERFACE_IF_OK_AND_REACHABLE(
-                BrOnCast, obj, rtt, value_on_branch, branch_depth.depth);
+        if (!VALIDATE(TypeCheckBranch<true>(c, 0))) return 0;
+        // This logic ensures that code generation can assume that functions
+        // can only be cast to function types, and data objects to data types.
+        if (V8_LIKELY(ObjectRelatedWithRtt(obj, rtt))) {
+          // The {value_on_branch} parameter we pass to the interface must
+          // be pointer-identical to the object on the stack, so we can't
+          // reuse {result_on_branch} which was passed-by-value to {Push}.
+          Value* value_on_branch = stack_value(1);
+          if (V8_LIKELY(current_code_reachable_and_ok_)) {
+            CALL_INTERFACE(BrOnCast, obj, rtt, value_on_branch,
+                           branch_depth.depth);
             c->br_merge()->reached = true;
           }
-          // Otherwise the types are unrelated. Do not branch.
-        } else if (check_result == kInvalidStack) {
-          return 0;
         }
+        // Otherwise the types are unrelated. Do not branch.
         Drop(result_on_branch);
         Push(obj);  // Restore stack state on fallthrough.
         return opcode_length + branch_depth.length;
@@ -4510,25 +4443,20 @@ class WasmFullDecoder : public WasmDecoder<validate> {
         Value result_on_branch =
             CreateValue(ValueType::Ref(heap_type, kNonNullable));
         Push(result_on_branch);
-        TypeCheckBranchResult check_result = TypeCheckBranch(c, true, 0);
-        if (V8_LIKELY(check_result == kReachableBranch)) {
-          // The {value_on_branch} parameter we pass to the interface must be
-          // pointer-identical to the object on the stack, so we can't reuse
-          // {result_on_branch} which was passed-by-value to {Push}.
-          Value* value_on_branch = stack_value(1);
+        if (!VALIDATE(TypeCheckBranch<true>(c, 0))) return 0;
+        // The {value_on_branch} parameter we pass to the interface must be
+        // pointer-identical to the object on the stack, so we can't reuse
+        // {result_on_branch} which was passed-by-value to {Push}.
+        Value* value_on_branch = stack_value(1);
+        if (V8_LIKELY(current_code_reachable_and_ok_)) {
           if (opcode == kExprBrOnFunc) {
-            CALL_INTERFACE_IF_OK_AND_REACHABLE(BrOnFunc, obj, value_on_branch,
-                                               branch_depth.depth);
+            CALL_INTERFACE(BrOnFunc, obj, value_on_branch, branch_depth.depth);
           } else if (opcode == kExprBrOnData) {
-            CALL_INTERFACE_IF_OK_AND_REACHABLE(BrOnData, obj, value_on_branch,
-                                               branch_depth.depth);
+            CALL_INTERFACE(BrOnData, obj, value_on_branch, branch_depth.depth);
           } else {
-            CALL_INTERFACE_IF_OK_AND_REACHABLE(BrOnI31, obj, value_on_branch,
-                                               branch_depth.depth);
+            CALL_INTERFACE(BrOnI31, obj, value_on_branch, branch_depth.depth);
           }
           c->br_merge()->reached = true;
-        } else if (check_result == kInvalidStack) {
-          return 0;
         }
         Drop(result_on_branch);
         Push(obj);  // Restore stack state on fallthrough.
@@ -4714,11 +4642,6 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     }
   }
 
-  void DoReturn() {
-    DCHECK_GE(stack_size(), this->sig_->return_count());
-    CALL_INTERFACE_IF_OK_AND_REACHABLE(DoReturn, 0);
-  }
-
   V8_INLINE void EnsureStackSpace(int slots_needed) {
     if (V8_LIKELY(stack_capacity_end_ - stack_end_ >= slots_needed)) return;
     GrowStackSpace(slots_needed);
@@ -4842,7 +4765,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     // TODO(wasm): This check is often redundant.
     if (V8_UNLIKELY(stack_size() < limit + count)) {
       // Popping past the current control start in reachable code.
-      if (!VALIDATE(!control_.back().reachable())) {
+      if (!VALIDATE(!current_code_reachable_and_ok_)) {
         NotEnoughArgumentsError(0);
       }
       // Pop what we can.
@@ -4854,188 +4777,152 @@ class WasmFullDecoder : public WasmDecoder<validate> {
   // For more descriptive call sites:
   V8_INLINE void Drop(const Value& /* unused */) { Drop(1); }
 
-  // Pops values from the stack, as defined by {merge}. Thereby we type-check
-  // unreachable merges. Afterwards the values are pushed again on the stack
-  // according to the signature in {merge}. This is done so follow-up validation
-  // is possible.
-  bool TypeCheckUnreachableMerge(Merge<Value>& merge, bool conditional_branch,
-                                 uint32_t drop_values = 0) {
-    int arity = merge.arity;
-    // For conditional branches, stack value '0' is the condition of the branch,
-    // and the result values start at index '1'.
-    int index_offset = conditional_branch ? 1 : 0;
+  enum StackElementsCountMode : bool {
+    kNonStrictCounting = false,
+    kStrictCounting = true
+  };
+
+  enum MergeType { kBranchMerge, kReturnMerge, kFallthroughMerge };
+
+  // - If the current code is reachable, check if the current stack values are
+  //   compatible with {merge} based on their number and types. Disregard the
+  //   first {drop_values} on the stack. If {strict_count}, check that
+  //   #(stack elements) == {merge->arity}, otherwise
+  //   #(stack elements) >= {merge->arity}.
+  // - If the current code is unreachable, check if any values that may exist on
+  //   top of the stack are compatible with {merge}. If {push_branch_values},
+  //   push back to the stack values based on the type of {merge} (this is
+  //   needed for conditional branches due to their typing rules, and
+  //   fallthroughs so that the outer control finds the expected values on the
+  //   stack). TODO(manoskouk): We expect the unreachable-code behavior to
+  //   change, either due to relaxation of dead code verification, or the
+  //   introduction of subtyping.
+  template <StackElementsCountMode strict_count, bool push_branch_values,
+            MergeType merge_type>
+  bool TypeCheckStackAgainstMerge(uint32_t drop_values, Merge<Value>* merge) {
+    static_assert(validate, "Call this function only within VALIDATE");
+    constexpr const char* merge_description =
+        merge_type == kBranchMerge
+            ? "branch"
+            : merge_type == kReturnMerge ? "return" : "fallthru";
+    uint32_t arity = merge->arity;
+    uint32_t actual = stack_size() - control_.back().stack_depth;
+    if (V8_LIKELY(current_code_reachable_and_ok_)) {
+      if (V8_UNLIKELY(strict_count ? actual != drop_values + arity
+                                   : actual < drop_values + arity)) {
+        this->DecodeError("expected %u elements on the stack for %s, found %u",
+                          arity, merge_description,
+                          actual >= drop_values ? actual - drop_values : 0);
+        return false;
+      }
+      // Typecheck the topmost {merge->arity} values on the stack.
+      Value* stack_values = stack_end_ - (arity + drop_values);
+      for (uint32_t i = 0; i < arity; ++i) {
+        Value& val = stack_values[i];
+        Value& old = (*merge)[i];
+        if (!IsSubtypeOf(val.type, old.type, this->module_)) {
+          this->DecodeError("type error in %s[%u] (expected %s, got %s)",
+                            merge_description, i, old.type.name().c_str(),
+                            val.type.name().c_str());
+          return false;
+        }
+      }
+      return true;
+    }
+    // Unreachable code validation starts here.
+    if (V8_UNLIKELY(strict_count && actual > drop_values + arity)) {
+      this->DecodeError("expected %u elements on the stack for %s, found %u",
+                        arity, merge_description,
+                        actual >= drop_values ? actual - drop_values : 0);
+      return false;
+    }
+    // TODO(manoskouk): Use similar code as above if we keep unreachable checks.
     for (int i = arity - 1, depth = drop_values; i >= 0; --i, ++depth) {
-      Peek(depth, index_offset + i, merge[i].type);
-    }
-    // Push values of the correct type onto the stack.
-    Drop(drop_values);
-    Drop(arity);
-    // {Drop} is adaptive for polymorphic stacks: it might drop fewer values
-    // than requested. So ensuring stack space here is not redundant.
-    EnsureStackSpace(arity + drop_values);
-    for (int i = 0; i < arity; i++) Push(CreateValue(merge[i].type));
-    // {drop_values} are about to be dropped anyway, so we can forget their
-    // previous types, but we do have to maintain the correct stack height.
-    for (uint32_t i = 0; i < drop_values; i++) {
-      Push(UnreachableValue(this->pc_));
+      Peek(depth, i, (*merge)[i].type);
+    }
+    if (push_branch_values) {
+      Drop(drop_values);
+      Drop(arity);
+      // {Drop} is adaptive for polymorphic stacks: it might drop fewer values
+      // than requested. So ensuring stack space here is not redundant.
+      EnsureStackSpace(drop_values + arity);
+      // Push values of the correct type onto the stack.
+      for (int i = 0; i < static_cast<int>(arity); i++) {
+        Push(CreateValue((*merge)[i].type));
+      }
+      // {drop_values} are about to be dropped anyway, so we can forget their
+      // previous types, but we do have to maintain the correct stack height.
+      for (uint32_t i = 0; i < drop_values; i++) {
+        Push(UnreachableValue(this->pc_));
+      }
     }
     return this->ok();
   }
 
+  template <StackElementsCountMode strict_count, MergeType merge_type>
+  bool DoReturn() {
+    if (!VALIDATE((TypeCheckStackAgainstMerge<strict_count, false, merge_type>(
+            0, &control_.front().end_merge)))) {
+      return false;
+    }
+    DCHECK_IMPLIES(current_code_reachable_and_ok_,
+                   stack_size() >= this->sig_->return_count());
+    CALL_INTERFACE_IF_OK_AND_REACHABLE(DoReturn, 0);
+    EndControl();
+    return true;
+  }
+
   int startrel(const byte* ptr) { return static_cast<int>(ptr - this->start_); }
 
-  void FallThruTo(Control* c) {
-    DCHECK_EQ(c, &control_.back());
+  void FallThrough() {
+    Control* c = &control_.back();
     DCHECK_NE(c->kind, kControlLoop);
-    if (!TypeCheckFallThru()) return;
+    if (!VALIDATE(TypeCheckFallThru())) return;
     CALL_INTERFACE_IF_OK_AND_REACHABLE(FallThruTo, c);
     if (c->reachable()) c->end_merge.reached = true;
   }
 
-  bool TypeCheckMergeValues(Control* c, uint32_t drop_values,
-                            Merge<Value>* merge) {
-    static_assert(validate, "Call this function only within VALIDATE");
-    DCHECK(merge == &c->start_merge || merge == &c->end_merge);
-    DCHECK_GE(stack_size() - drop_values, c->stack_depth + merge->arity);
-    Value* stack_values = stack_value(merge->arity + drop_values);
-    // Typecheck the topmost {merge->arity} values on the stack.
-    for (uint32_t i = 0; i < merge->arity; ++i) {
-      Value& val = stack_values[i];
-      Value& old = (*merge)[i];
-      if (!VALIDATE(IsSubtypeOf(val.type, old.type, this->module_))) {
-        this->DecodeError("type error in merge[%u] (expected %s, got %s)", i,
-                          old.type.name().c_str(), val.type.name().c_str());
-        return false;
-      }
-    }
-
-    return true;
-  }
-
   bool TypeCheckOneArmedIf(Control* c) {
     static_assert(validate, "Call this function only within VALIDATE");
     DCHECK(c->is_onearmed_if());
-    DCHECK_EQ(c->start_merge.arity, c->end_merge.arity);
+    if (c->end_merge.arity != c->start_merge.arity) {
+      this->DecodeError(c->pc(),
+                        "start-arity and end-arity of one-armed if must match");
+      return false;
+    }
     for (uint32_t i = 0; i < c->start_merge.arity; ++i) {
       Value& start = c->start_merge[i];
       Value& end = c->end_merge[i];
-      if (!VALIDATE(IsSubtypeOf(start.type, end.type, this->module_))) {
+      if (!IsSubtypeOf(start.type, end.type, this->module_)) {
         this->DecodeError("type error in merge[%u] (expected %s, got %s)", i,
                           end.type.name().c_str(), start.type.name().c_str());
         return false;
       }
     }
-
     return true;
   }
 
   bool TypeCheckFallThru() {
     static_assert(validate, "Call this function only within VALIDATE");
-    Control& c = control_.back();
-    if (V8_LIKELY(c.reachable())) {
-      uint32_t expected = c.end_merge.arity;
-      DCHECK_GE(stack_size(), c.stack_depth);
-      uint32_t actual = stack_size() - c.stack_depth;
-      // Fallthrus must match the arity of the control exactly.
-      if (!VALIDATE(actual == expected)) {
-        this->DecodeError(
-            "expected %u elements on the stack for fallthru to @%d, found %u",
-            expected, startrel(c.pc()), actual);
-        return false;
-      }
-      if (expected == 0) return true;  // Fast path.
-
-      return TypeCheckMergeValues(&c, 0, &c.end_merge);
-    }
-
-    // Type-check an unreachable fallthru. First we do an arity check, then a
-    // type check. Note that type-checking may require an adjustment of the
-    // stack, if some stack values are missing to match the block signature.
-    Merge<Value>& merge = c.end_merge;
-    int arity = static_cast<int>(merge.arity);
-    int available = static_cast<int>(stack_size()) - c.stack_depth;
-    // For fallthrus, not more than the needed values should be available.
-    if (!VALIDATE(available <= arity)) {
-      this->DecodeError(
-          "expected %u elements on the stack for fallthru to @%d, found %u",
-          arity, startrel(c.pc()), available);
-      return false;
-    }
-    // Pop all values from the stack for type checking of existing stack
-    // values.
-    return TypeCheckUnreachableMerge(merge, false);
+    return TypeCheckStackAgainstMerge<kStrictCounting, true, kFallthroughMerge>(
+        0, &control_.back().end_merge);
   }
 
-  enum TypeCheckBranchResult {
-    kReachableBranch,
-    kUnreachableBranch,
-    kInvalidStack,
-  };
-
-  // If the type code is reachable, check if the current stack values are
+  // If the current code is reachable, check if the current stack values are
   // compatible with a jump to {c}, based on their number and types.
   // Otherwise, we have a polymorphic stack: check if any values that may exist
-  // on top of the stack are compatible with {c}, and push back to the stack
-  // values based on the type of {c}.
-  TypeCheckBranchResult TypeCheckBranch(Control* c, bool conditional_branch,
-                                        uint32_t drop_values) {
-    if (V8_LIKELY(control_.back().reachable())) {
-      // We only do type-checking here. This is only needed during validation.
-      if (!validate) return kReachableBranch;
-
-      // Branches must have at least the number of values expected; can have
-      // more.
-      uint32_t expected = c->br_merge()->arity;
-      if (expected == 0) return kReachableBranch;  // Fast path.
-      uint32_t limit = control_.back().stack_depth;
-      if (!VALIDATE(stack_size() >= limit + drop_values + expected)) {
-        uint32_t actual = stack_size() - limit;
-        actual -= std::min(actual, drop_values);
-        this->DecodeError(
-            "expected %u elements on the stack for br to @%d, found %u",
-            expected, startrel(c->pc()), actual);
-        return kInvalidStack;
-      }
-      return TypeCheckMergeValues(c, drop_values, c->br_merge())
-                 ? kReachableBranch
-                 : kInvalidStack;
-    }
-
-    return TypeCheckUnreachableMerge(*c->br_merge(), conditional_branch,
-                                     drop_values)
-               ? kUnreachableBranch
-               : kInvalidStack;
-  }
-
-  bool TypeCheckReturn() {
-    int num_returns = static_cast<int>(this->sig_->return_count());
-    // No type checking is needed if there are no returns.
-    if (num_returns == 0) return true;
-
-    // Returns must have at least the number of values expected; can have more.
-    int num_available =
-        static_cast<int>(stack_size()) - control_.back().stack_depth;
-    if (!VALIDATE(num_available >= num_returns)) {
-      this->DecodeError(
-          "expected %u elements on the stack for return, found %u", num_returns,
-          num_available);
-      return false;
-    }
-
-    // Typecheck the topmost {num_returns} values on the stack.
-    // This line requires num_returns > 0.
-    Value* stack_values = stack_end_ - num_returns;
-    for (int i = 0; i < num_returns; ++i) {
-      Value& val = stack_values[i];
-      ValueType expected_type = this->sig_->GetReturn(i);
-      if (!VALIDATE(IsSubtypeOf(val.type, expected_type, this->module_))) {
-        this->DecodeError("type error in return[%u] (expected %s, got %s)", i,
-                          expected_type.name().c_str(),
-                          val.type.name().c_str());
-        return false;
-      }
-    }
-    return true;
+  // on top of the stack are compatible with {c}. If {push_branch_values},
+  // push back to the stack values based on the type of {c} (this is needed for
+  // conditional branches due to their typing rules, and fallthroughs so that
+  // the outer control finds enough values on the stack).
+  // {drop_values} is the number of stack values that will be dropped before the
+  // branch is taken. This is currently 1 for for br (condition), br_table
+  // (index) and br_on_null (reference), and 0 for all other branches.
+  template <bool push_branch_values>
+  bool TypeCheckBranch(Control* c, uint32_t drop_values) {
+    static_assert(validate, "Call this function only within VALIDATE");
+    return TypeCheckStackAgainstMerge<kNonStrictCounting, push_branch_values,
+                                      kBranchMerge>(drop_values, c->br_merge());
   }
 
   void onFirstError() override {
diff --git a/chromium/v8/src/wasm/function-compiler.cc b/chromium/v8/src/wasm/function-compiler.cc
index 4303344f136..4a2db3d496e 100644
--- a/chromium/v8/src/wasm/function-compiler.cc
+++ b/chromium/v8/src/wasm/function-compiler.cc
@@ -306,7 +306,8 @@ JSToWasmWrapperCompilationUnit::JSToWasmWrapperCompilationUnit(
     Isolate* isolate, WasmEngine* wasm_engine, const FunctionSig* sig,
     const WasmModule* module, bool is_import,
     const WasmFeatures& enabled_features, AllowGeneric allow_generic)
-    : is_import_(is_import),
+    : isolate_(isolate),
+      is_import_(is_import),
       sig_(sig),
       use_generic_wrapper_(allow_generic && UseGenericWrapper(sig) &&
                            !is_import),
@@ -326,19 +327,19 @@ void JSToWasmWrapperCompilationUnit::Execute() {
   }
 }
 
-Handle<Code> JSToWasmWrapperCompilationUnit::Finalize(Isolate* isolate) {
+Handle<Code> JSToWasmWrapperCompilationUnit::Finalize() {
   Handle<Code> code;
   if (use_generic_wrapper_) {
     code =
-        isolate->builtins()->builtin_handle(Builtins::kGenericJSToWasmWrapper);
+        isolate_->builtins()->builtin_handle(Builtins::kGenericJSToWasmWrapper);
   } else {
-    CompilationJob::Status status = job_->FinalizeJob(isolate);
+    CompilationJob::Status status = job_->FinalizeJob(isolate_);
     CHECK_EQ(status, CompilationJob::SUCCEEDED);
     code = job_->compilation_info()->code();
   }
-  if (!use_generic_wrapper_ && must_record_function_compilation(isolate)) {
+  if (!use_generic_wrapper_ && must_record_function_compilation(isolate_)) {
     RecordWasmHeapStubCompilation(
-        isolate, code, "%s", job_->compilation_info()->GetDebugName().get());
+        isolate_, code, "%s", job_->compilation_info()->GetDebugName().get());
   }
   return code;
 }
@@ -353,7 +354,7 @@ Handle<Code> JSToWasmWrapperCompilationUnit::CompileJSToWasmWrapper(
                                       module, is_import, enabled_features,
                                       kAllowGeneric);
   unit.Execute();
-  return unit.Finalize(isolate);
+  return unit.Finalize();
 }
 
 // static
@@ -366,7 +367,7 @@ Handle<Code> JSToWasmWrapperCompilationUnit::CompileSpecificJSToWasmWrapper(
                                       module, is_import, enabled_features,
                                       kDontAllowGeneric);
   unit.Execute();
-  return unit.Finalize(isolate);
+  return unit.Finalize();
 }
 
 }  // namespace wasm
diff --git a/chromium/v8/src/wasm/function-compiler.h b/chromium/v8/src/wasm/function-compiler.h
index f8d1f00a4e4..80cd1a7b679 100644
--- a/chromium/v8/src/wasm/function-compiler.h
+++ b/chromium/v8/src/wasm/function-compiler.h
@@ -127,8 +127,10 @@ class V8_EXPORT_PRIVATE JSToWasmWrapperCompilationUnit final {
                                  AllowGeneric allow_generic);
   ~JSToWasmWrapperCompilationUnit();
 
+  Isolate* isolate() const { return isolate_; }
+
   void Execute();
-  Handle<Code> Finalize(Isolate* isolate);
+  Handle<Code> Finalize();
 
   bool is_import() const { return is_import_; }
   const FunctionSig* sig() const { return sig_; }
@@ -146,6 +148,11 @@ class V8_EXPORT_PRIVATE JSToWasmWrapperCompilationUnit final {
                                                      const WasmModule* module);
 
  private:
+  // Wrapper compilation is bound to an isolate. Concurrent accesses to the
+  // isolate (during the "Execute" phase) must be audited carefully, i.e. we
+  // should only access immutable information (like the root table). The isolate
+  // is guaranteed to be alive when this unit executes.
+  Isolate* isolate_;
   bool is_import_;
   const FunctionSig* sig_;
   bool use_generic_wrapper_;
diff --git a/chromium/v8/src/wasm/graph-builder-interface.cc b/chromium/v8/src/wasm/graph-builder-interface.cc
index c856f4d9493..c8b7d1834e4 100644
--- a/chromium/v8/src/wasm/graph-builder-interface.cc
+++ b/chromium/v8/src/wasm/graph-builder-interface.cc
@@ -9,6 +9,7 @@
 #include "src/handles/handles.h"
 #include "src/objects/objects-inl.h"
 #include "src/utils/ostreams.h"
+#include "src/wasm/branch-hint-map.h"
 #include "src/wasm/decoder.h"
 #include "src/wasm/function-body-decoder-impl.h"
 #include "src/wasm/function-body-decoder.h"
@@ -29,7 +30,7 @@ namespace {
 // It maintains a control state that tracks whether the environment
 // is reachable, has reached a control end, or has been merged.
 struct SsaEnv : public ZoneObject {
-  enum State { kControlEnd, kUnreachable, kReached, kMerged };
+  enum State { kUnreachable, kReached, kMerged };
 
   State state;
   TFNode* control;
@@ -50,11 +51,11 @@ struct SsaEnv : public ZoneObject {
                                        effect(other.effect),
                                        instance_cache(other.instance_cache),
                                        locals(std::move(other.locals)) {
-    other.Kill(kUnreachable);
+    other.Kill();
   }
 
-  void Kill(State new_state = kControlEnd) {
-    state = new_state;
+  void Kill() {
+    state = kUnreachable;
     for (TFNode*& local : locals) {
       local = nullptr;
     }
@@ -67,8 +68,6 @@ struct SsaEnv : public ZoneObject {
   }
 };
 
-constexpr uint32_t kNullCatch = static_cast<uint32_t>(-1);
-
 class WasmGraphBuildingInterface {
  public:
   static constexpr Decoder::ValidateFlag validate = Decoder::kFullValidation;
@@ -97,7 +96,7 @@ class WasmGraphBuildingInterface {
   };
 
   struct Control : public ControlBase<Value, validate> {
-    SsaEnv* end_env = nullptr;    // end environment for the construct.
+    SsaEnv* merge_env = nullptr;  // merge environment for the construct.
     SsaEnv* false_env = nullptr;  // false environment (only for if).
     TryInfo* try_info = nullptr;  // information about try statements.
     int32_t previous_catch = -1;  // previous Control with a catch.
@@ -110,10 +109,18 @@ class WasmGraphBuildingInterface {
         : ControlBase(std::forward<Args>(args)...) {}
   };
 
-  explicit WasmGraphBuildingInterface(compiler::WasmGraphBuilder* builder)
-      : builder_(builder) {}
+  explicit WasmGraphBuildingInterface(compiler::WasmGraphBuilder* builder,
+                                      int func_index)
+      : builder_(builder), func_index_(func_index) {}
 
   void StartFunction(FullDecoder* decoder) {
+    // Get the branch hints map for this function (if available)
+    if (decoder->module_) {
+      auto branch_hints_it = decoder->module_->branch_hints.find(func_index_);
+      if (branch_hints_it != decoder->module_->branch_hints.end()) {
+        branch_hints_ = &branch_hints_it->second;
+      }
+    }
     // The first '+ 1' is needed by TF Start node, the second '+ 1' is for the
     // instance parameter.
     builder_->Start(static_cast<int>(decoder->sig_->parameter_count() + 1 + 1));
@@ -156,15 +163,15 @@ class WasmGraphBuildingInterface {
 
   void Block(FullDecoder* decoder, Control* block) {
     // The branch environment is the outer environment.
-    block->end_env = ssa_env_;
+    block->merge_env = ssa_env_;
     SetEnv(Steal(decoder->zone(), ssa_env_));
   }
 
   void Loop(FullDecoder* decoder, Control* block) {
-    SsaEnv* finish_try_env = Steal(decoder->zone(), ssa_env_);
-    block->end_env = finish_try_env;
-    SetEnv(finish_try_env);
-    // The continue environment is the inner environment.
+    // This is the merge environment at the beginning of the loop.
+    SsaEnv* merge_env = Steal(decoder->zone(), ssa_env_);
+    block->merge_env = merge_env;
+    SetEnv(merge_env);
 
     ssa_env_->state = SsaEnv::kMerged;
 
@@ -216,15 +223,15 @@ class WasmGraphBuildingInterface {
                                             control());
     }
 
+    // Now we setup a new environment for the inside of the loop.
     SetEnv(Split(decoder->zone(), ssa_env_));
     builder_->StackCheck(decoder->position());
-
     ssa_env_->SetNotMerged();
-    if (!decoder->ok()) return;
+
     // Wrap input merge into phis.
     for (uint32_t i = 0; i < block->start_merge.arity; ++i) {
       Value& val = block->start_merge[i];
-      TFNode* inputs[] = {val.node, block->end_env->control};
+      TFNode* inputs[] = {val.node, block->merge_env->control};
       val.node = builder_->Phi(val.type, 1, inputs);
     }
   }
@@ -238,22 +245,34 @@ class WasmGraphBuildingInterface {
     SsaEnv* try_env = Steal(decoder->zone(), outer_env);
     SetEnv(try_env);
     TryInfo* try_info = decoder->zone()->New<TryInfo>(catch_env);
-    block->end_env = outer_env;
+    block->merge_env = outer_env;
     block->try_info = try_info;
-    block->previous_catch = current_catch_;
-    current_catch_ = static_cast<int32_t>(decoder->control_depth() - 1);
   }
 
   void If(FullDecoder* decoder, const Value& cond, Control* if_block) {
     TFNode* if_true = nullptr;
     TFNode* if_false = nullptr;
-    builder_->BranchNoHint(cond.node, &if_true, &if_false);
-    SsaEnv* end_env = ssa_env_;
+    WasmBranchHint hint = WasmBranchHint::kNoHint;
+    if (branch_hints_) {
+      hint = branch_hints_->GetHintFor(decoder->pc_relative_offset());
+    }
+    switch (hint) {
+      case WasmBranchHint::kNoHint:
+        builder_->BranchNoHint(cond.node, &if_true, &if_false);
+        break;
+      case WasmBranchHint::kUnlikely:
+        builder_->BranchExpectFalse(cond.node, &if_true, &if_false);
+        break;
+      case WasmBranchHint::kLikely:
+        builder_->BranchExpectTrue(cond.node, &if_true, &if_false);
+        break;
+    }
+    SsaEnv* merge_env = ssa_env_;
     SsaEnv* false_env = Split(decoder->zone(), ssa_env_);
     false_env->control = if_false;
     SsaEnv* true_env = Steal(decoder->zone(), ssa_env_);
     true_env->control = if_true;
-    if_block->end_env = end_env;
+    if_block->merge_env = merge_env;
     if_block->false_env = false_env;
     SetEnv(true_env);
   }
@@ -294,11 +313,9 @@ class WasmGraphBuildingInterface {
       MergeValuesInto(decoder, block, &block->end_merge, values);
     }
     // Now continue with the merged environment.
-    SetEnv(block->end_env);
+    SetEnv(block->merge_env);
   }
 
-  void EndControl(FullDecoder* decoder, Control* block) { ssa_env_->Kill(); }
-
   void UnOp(FullDecoder* decoder, WasmOpcode opcode, const Value& value,
             Value* result) {
     result->node = builder_->Unop(opcode, value.node, decoder->position());
@@ -482,7 +499,21 @@ class WasmGraphBuildingInterface {
     SsaEnv* fenv = ssa_env_;
     SsaEnv* tenv = Split(decoder->zone(), fenv);
     fenv->SetNotMerged();
-    builder_->BranchNoHint(cond.node, &tenv->control, &fenv->control);
+    WasmBranchHint hint = WasmBranchHint::kNoHint;
+    if (branch_hints_) {
+      hint = branch_hints_->GetHintFor(decoder->pc_relative_offset());
+    }
+    switch (hint) {
+      case WasmBranchHint::kNoHint:
+        builder_->BranchNoHint(cond.node, &tenv->control, &fenv->control);
+        break;
+      case WasmBranchHint::kUnlikely:
+        builder_->BranchExpectFalse(cond.node, &tenv->control, &fenv->control);
+        break;
+      case WasmBranchHint::kLikely:
+        builder_->BranchExpectTrue(cond.node, &tenv->control, &fenv->control);
+        break;
+    }
     builder_->SetControl(fenv->control);
     SetEnv(tenv);
     BrOrRet(decoder, depth, 1);
@@ -639,6 +670,19 @@ class WasmGraphBuildingInterface {
     SetEnv(false_env);
   }
 
+  void BrOnNonNull(FullDecoder* decoder, const Value& ref_object,
+                   uint32_t depth) {
+    SsaEnv* false_env = ssa_env_;
+    SsaEnv* true_env = Split(decoder->zone(), false_env);
+    false_env->SetNotMerged();
+    builder_->BrOnNull(ref_object.node, &false_env->control,
+                       &true_env->control);
+    builder_->SetControl(false_env->control);
+    SetEnv(true_env);
+    BrOrRet(decoder, depth, 0);
+    SetEnv(false_env);
+  }
+
   void SimdOp(FullDecoder* decoder, WasmOpcode opcode, Vector<Value> args,
               Value* result) {
     NodeVector inputs(args.size());
@@ -689,9 +733,6 @@ class WasmGraphBuildingInterface {
                       const ExceptionIndexImmediate<validate>& imm,
                       Control* block, Vector<Value> values) {
     DCHECK(block->is_try_catch());
-
-    current_catch_ = block->previous_catch;  // Pop try scope.
-
     // The catch block is unreachable if no possible throws in the try block
     // exist. We only build a landing pad if some node in the try block can
     // (possibly) throw. Otherwise the catch environments remain empty.
@@ -743,7 +784,6 @@ class WasmGraphBuildingInterface {
         // and IfFailure nodes.
         builder_->Rethrow(block->try_info->exception);
         TerminateThrow(decoder);
-        current_catch_ = block->previous_catch;
         return;
       }
       DCHECK(decoder->control_at(depth)->is_try());
@@ -765,7 +805,6 @@ class WasmGraphBuildingInterface {
             target_try->exception, block->try_info->exception);
       }
     }
-    current_catch_ = block->previous_catch;
   }
 
   void CatchAll(FullDecoder* decoder, Control* block) {
@@ -773,8 +812,6 @@ class WasmGraphBuildingInterface {
            block->is_try_unwind());
     DCHECK_EQ(decoder->control_at(0), block);
 
-    current_catch_ = block->previous_catch;  // Pop try scope.
-
     // The catch block is unreachable if no possible throws in the try block
     // exist. We only build a landing pad if some node in the try block can
     // (possibly) throw. Otherwise the catch environments remain empty.
@@ -1080,7 +1117,8 @@ class WasmGraphBuildingInterface {
  private:
   SsaEnv* ssa_env_ = nullptr;
   compiler::WasmGraphBuilder* builder_;
-  uint32_t current_catch_ = kNullCatch;
+  int func_index_;
+  const BranchHintMap* branch_hints_ = nullptr;
   // Tracks loop data for loop unrolling.
   std::vector<compiler::WasmLoopInfo> loop_infos_;
 
@@ -1088,13 +1126,9 @@ class WasmGraphBuildingInterface {
 
   TFNode* control() { return builder_->control(); }
 
-  uint32_t control_depth_of_current_catch(FullDecoder* decoder) {
-    return decoder->control_depth() - 1 - current_catch_;
-  }
-
   TryInfo* current_try_info(FullDecoder* decoder) {
-    DCHECK_LT(current_catch_, decoder->control_depth());
-    return decoder->control_at(control_depth_of_current_catch(decoder))
+    DCHECK_LT(decoder->current_catch(), decoder->control_depth());
+    return decoder->control_at(decoder->control_depth_of_current_catch())
         ->try_info;
   }
 
@@ -1122,9 +1156,6 @@ class WasmGraphBuildingInterface {
           case SsaEnv::kMerged:
             state = 'M';
             break;
-          case SsaEnv::kControlEnd:
-            state = 'E';
-            break;
         }
       }
       PrintF("{set_env = %p, state = %c", env, state);
@@ -1146,7 +1177,7 @@ class WasmGraphBuildingInterface {
   V8_INLINE TFNode* CheckForException(FullDecoder* decoder, TFNode* node) {
     if (node == nullptr) return nullptr;
 
-    const bool inside_try_scope = current_catch_ != kNullCatch;
+    const bool inside_try_scope = decoder->current_catch() != -1;
     if (!inside_try_scope) return node;
 
     return CheckForExceptionImpl(decoder, node);
@@ -1170,7 +1201,7 @@ class WasmGraphBuildingInterface {
     TryInfo* try_info = current_try_info(decoder);
     if (FLAG_wasm_loop_unrolling) {
       ValueVector values;
-      BuildNestedLoopExits(decoder, control_depth_of_current_catch(decoder),
+      BuildNestedLoopExits(decoder, decoder->control_depth_of_current_catch(),
                            true, values, &if_exception);
     }
     Goto(decoder, try_info->catch_env);
@@ -1218,8 +1249,10 @@ class WasmGraphBuildingInterface {
                        Value* values) {
     DCHECK(merge == &c->start_merge || merge == &c->end_merge);
 
-    SsaEnv* target = c->end_env;
+    SsaEnv* target = c->merge_env;
+    // This has to be computed before calling Goto().
     const bool first = target->state == SsaEnv::kUnreachable;
+
     Goto(decoder, target);
 
     if (merge->arity == 0) return;
@@ -1327,7 +1360,6 @@ class WasmGraphBuildingInterface {
       default:
         UNREACHABLE();
     }
-    return ssa_env_->Kill();
   }
 
   // Create a complete copy of {from}.
@@ -1357,11 +1389,6 @@ class WasmGraphBuildingInterface {
     return result;
   }
 
-  // Create an unreachable environment.
-  SsaEnv* UnreachableEnv(Zone* zone) {
-    return zone->New<SsaEnv>(zone, SsaEnv::kUnreachable, nullptr, nullptr, 0);
-  }
-
   void DoCall(FullDecoder* decoder, CallMode call_mode, uint32_t table_index,
               CheckForNull null_check, TFNode* caller_node,
               const FunctionSig* sig, uint32_t sig_index, const Value args[],
@@ -1523,10 +1550,11 @@ DecodeResult BuildTFGraph(AccountingAllocator* allocator,
                           compiler::WasmGraphBuilder* builder,
                           WasmFeatures* detected, const FunctionBody& body,
                           std::vector<compiler::WasmLoopInfo>* loop_infos,
-                          compiler::NodeOriginTable* node_origins) {
+                          compiler::NodeOriginTable* node_origins,
+                          int func_index) {
   Zone zone(allocator, ZONE_NAME);
   WasmFullDecoder<Decoder::kFullValidation, WasmGraphBuildingInterface> decoder(
-      &zone, module, enabled, detected, body, builder);
+      &zone, module, enabled, detected, body, builder, func_index);
   if (node_origins) {
     builder->AddBytecodePositionDecorator(node_origins, &decoder);
   }
diff --git a/chromium/v8/src/wasm/graph-builder-interface.h b/chromium/v8/src/wasm/graph-builder-interface.h
index ce125313e44..6c668e2b0a0 100644
--- a/chromium/v8/src/wasm/graph-builder-interface.h
+++ b/chromium/v8/src/wasm/graph-builder-interface.h
@@ -10,7 +10,6 @@
 #define V8_WASM_GRAPH_BUILDER_INTERFACE_H_
 
 #include "src/wasm/decoder.h"
-#include "src/wasm/wasm-opcodes.h"
 #include "src/wasm/wasm-result.h"
 
 namespace v8 {
@@ -33,7 +32,7 @@ BuildTFGraph(AccountingAllocator* allocator, const WasmFeatures& enabled,
              const WasmModule* module, compiler::WasmGraphBuilder* builder,
              WasmFeatures* detected, const FunctionBody& body,
              std::vector<compiler::WasmLoopInfo>* loop_infos,
-             compiler::NodeOriginTable* node_origins);
+             compiler::NodeOriginTable* node_origins, int func_index);
 
 }  // namespace wasm
 }  // namespace internal
diff --git a/chromium/v8/src/wasm/memory-protection-key.cc b/chromium/v8/src/wasm/memory-protection-key.cc
new file mode 100644
index 00000000000..e8252cd9ce9
--- /dev/null
+++ b/chromium/v8/src/wasm/memory-protection-key.cc
@@ -0,0 +1,189 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/wasm/memory-protection-key.h"
+
+#if defined(V8_OS_LINUX) && defined(V8_HOST_ARCH_X64)
+#include <sys/mman.h>  // For {mprotect()} protection macros.
+#undef MAP_TYPE  // Conflicts with MAP_TYPE in Torque-generated instance-types.h
+#endif
+
+#include "src/base/build_config.h"
+#include "src/base/logging.h"
+#include "src/base/macros.h"
+#include "src/base/platform/platform.h"
+
+// Runtime-detection of PKU support with {dlsym()}.
+//
+// For now, we support memory protection keys/PKEYs/PKU only for Linux on x64
+// based on glibc functions {pkey_alloc()}, {pkey_free()}, etc.
+// Those functions are only available since glibc version 2.27:
+// https://man7.org/linux/man-pages/man2/pkey_alloc.2.html
+// However, if we check the glibc verison with V8_GLIBC_PREPREQ here at compile
+// time, this causes two problems due to dynamic linking of glibc:
+// 1) If the compiling system _has_ a new enough glibc, the binary will include
+// calls to {pkey_alloc()} etc., and then the runtime system must supply a
+// new enough glibc version as well. That is, this potentially breaks runtime
+// compatability on older systems (e.g., Ubuntu 16.04 with glibc 2.23).
+// 2) If the compiling system _does not_ have a new enough glibc, PKU support
+// will not be compiled in, even though the runtime system potentially _does_
+// have support for it due to a new enough Linux kernel and glibc version.
+// That is, this results in non-optimal security (PKU available, but not used).
+// Hence, we do _not_ check the glibc version during compilation, and instead
+// only at runtime try to load {pkey_alloc()} etc. with {dlsym()}.
+// TODO(dlehmann): Move this import and freestanding functions below to
+// base/platform/platform.h {OS} (lower-level functions) and
+// {base::PageAllocator} (exported API).
+#if defined(V8_OS_LINUX) && defined(V8_HOST_ARCH_X64)
+#include <dlfcn.h>
+#endif
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+
+// TODO(dlehmann) Security: Are there alternatives to disabling CFI altogether
+// for the functions below? Since they are essentially an arbitrary indirect
+// call gadget, disabling CFI should be only a last resort. In Chromium, there
+// was {base::ProtectedMemory} to protect the function pointer from being
+// overwritten, but t seems it was removed to not begin used and AFAICT no such
+// thing exists in V8 to begin with. See
+// https://www.chromium.org/developers/testing/control-flow-integrity and
+// https://crrev.com/c/1884819.
+// What is the general solution for CFI + {dlsym()}?
+// An alternative would be to not rely on glibc and instead implement PKEY
+// directly on top of Linux syscalls + inline asm, but that is quite some low-
+// level code (probably in the order of 100 lines).
+DISABLE_CFI_ICALL
+int AllocateMemoryProtectionKey() {
+// See comment on the import on feature testing for PKEY support.
+#if defined(V8_OS_LINUX) && defined(V8_HOST_ARCH_X64)
+  // Try to to find {pkey_alloc()} support in glibc.
+  typedef int (*pkey_alloc_t)(unsigned int, unsigned int);
+  // Cache the {dlsym()} lookup in a {static} variable.
+  static auto* pkey_alloc =
+      bit_cast<pkey_alloc_t>(dlsym(RTLD_DEFAULT, "pkey_alloc"));
+  if (pkey_alloc != nullptr) {
+    // If there is support in glibc, try to allocate a new key.
+    // This might still return -1, e.g., because the kernel does not support
+    // PKU or because there is no more key available.
+    // Different reasons for why {pkey_alloc()} failed could be checked with
+    // errno, e.g., EINVAL vs ENOSPC vs ENOSYS. See manpages and glibc manual
+    // (the latter is the authorative source):
+    // https://www.gnu.org/software/libc/manual/html_mono/libc.html#Memory-Protection-Keys
+    return pkey_alloc(/* flags, unused */ 0, kDisableAccess);
+  }
+#endif
+  return kNoMemoryProtectionKey;
+}
+
+DISABLE_CFI_ICALL
+void FreeMemoryProtectionKey(int key) {
+  // Only free the key if one was allocated.
+  if (key == kNoMemoryProtectionKey) return;
+
+#if defined(V8_OS_LINUX) && defined(V8_HOST_ARCH_X64)
+  typedef int (*pkey_free_t)(int);
+  static auto* pkey_free =
+      bit_cast<pkey_free_t>(dlsym(RTLD_DEFAULT, "pkey_free"));
+  // If a valid key was allocated, {pkey_free()} must also be available.
+  DCHECK_NOT_NULL(pkey_free);
+
+  int ret = pkey_free(key);
+  CHECK_EQ(/* success */ 0, ret);
+#else
+  // On platforms without PKU support, we should have already returned because
+  // the key must be {kNoMemoryProtectionKey}.
+  UNREACHABLE();
+#endif
+}
+
+#if defined(V8_OS_LINUX) && defined(V8_HOST_ARCH_X64)
+// TODO(dlehmann): Copied from base/platform/platform-posix.cc. Should be
+// removed once this code is integrated in base/platform/platform-linux.cc.
+int GetProtectionFromMemoryPermission(base::OS::MemoryPermission access) {
+  switch (access) {
+    case base::OS::MemoryPermission::kNoAccess:
+    case base::OS::MemoryPermission::kNoAccessWillJitLater:
+      return PROT_NONE;
+    case base::OS::MemoryPermission::kRead:
+      return PROT_READ;
+    case base::OS::MemoryPermission::kReadWrite:
+      return PROT_READ | PROT_WRITE;
+    case base::OS::MemoryPermission::kReadWriteExecute:
+      return PROT_READ | PROT_WRITE | PROT_EXEC;
+    case base::OS::MemoryPermission::kReadExecute:
+      return PROT_READ | PROT_EXEC;
+  }
+  UNREACHABLE();
+}
+#endif
+
+DISABLE_CFI_ICALL
+bool SetPermissionsAndMemoryProtectionKey(
+    PageAllocator* page_allocator, base::AddressRegion region,
+    PageAllocator::Permission page_permissions, int key) {
+  DCHECK_NOT_NULL(page_allocator);
+
+  void* address = reinterpret_cast<void*>(region.begin());
+  size_t size = region.size();
+
+#if defined(V8_OS_LINUX) && defined(V8_HOST_ARCH_X64)
+  typedef int (*pkey_mprotect_t)(void*, size_t, int, int);
+  static auto* pkey_mprotect =
+      bit_cast<pkey_mprotect_t>(dlsym(RTLD_DEFAULT, "pkey_mprotect"));
+
+  if (pkey_mprotect == nullptr) {
+    // If there is no runtime support for {pkey_mprotect()}, no key should have
+    // been allocated in the first place.
+    DCHECK_EQ(kNoMemoryProtectionKey, key);
+
+    // Without PKU support, fallback to regular {mprotect()}.
+    return page_allocator->SetPermissions(address, size, page_permissions);
+  }
+
+  // Copied with slight modifications from base/platform/platform-posix.cc
+  // {OS::SetPermissions()}.
+  // TODO(dlehmann): Move this block into its own function at the right
+  // abstraction boundary (likely some static method in platform.h {OS})
+  // once the whole PKU code is moved into base/platform/.
+  DCHECK_EQ(0, region.begin() % page_allocator->CommitPageSize());
+  DCHECK_EQ(0, size % page_allocator->CommitPageSize());
+
+  int protection = GetProtectionFromMemoryPermission(
+      static_cast<base::OS::MemoryPermission>(page_permissions));
+
+  int ret = pkey_mprotect(address, size, protection, key);
+
+  return ret == /* success */ 0;
+#else
+  // Without PKU support, fallback to regular {mprotect()}.
+  return page_allocator->SetPermissions(address, size, page_permissions);
+#endif
+}
+
+DISABLE_CFI_ICALL
+bool SetPermissionsForMemoryProtectionKey(
+    int key, MemoryProtectionKeyPermission permissions) {
+  if (key == kNoMemoryProtectionKey) return false;
+
+#if defined(V8_OS_LINUX) && defined(V8_HOST_ARCH_X64)
+  typedef int (*pkey_set_t)(int, unsigned int);
+  static auto* pkey_set = bit_cast<pkey_set_t>(dlsym(RTLD_DEFAULT, "pkey_set"));
+  // If a valid key was allocated, {pkey_set()} must also be available.
+  DCHECK_NOT_NULL(pkey_set);
+
+  int ret = pkey_set(key, permissions);
+
+  return ret == /* success */ 0;
+#else
+  // On platforms without PKU support, we should have already returned because
+  // the key must be {kNoMemoryProtectionKey}.
+  UNREACHABLE();
+#endif
+}
+
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
diff --git a/chromium/v8/src/wasm/memory-protection-key.h b/chromium/v8/src/wasm/memory-protection-key.h
new file mode 100644
index 00000000000..9f9a200cdfe
--- /dev/null
+++ b/chromium/v8/src/wasm/memory-protection-key.h
@@ -0,0 +1,90 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#if !V8_ENABLE_WEBASSEMBLY
+#error This header should only be included if WebAssembly is enabled.
+#endif  // !V8_ENABLE_WEBASSEMBLY
+
+#ifndef V8_WASM_MEMORY_PROTECTION_KEY_H_
+#define V8_WASM_MEMORY_PROTECTION_KEY_H_
+
+#if defined(V8_OS_LINUX) && defined(V8_HOST_ARCH_X64)
+#include <sys/mman.h>  // For STATIC_ASSERT of permission values.
+#undef MAP_TYPE  // Conflicts with MAP_TYPE in Torque-generated instance-types.h
+#endif
+
+#include "include/v8-platform.h"
+#include "src/base/address-region.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+
+// TODO(dlehmann): Move this to base/platform/platform.h {OS} (lower-level API)
+// and {base::PageAllocator} (higher-level, exported API) once the API is more
+// stable and we have converged on a better design (e.g., typed class wrapper
+// around int memory protection key).
+
+// Sentinel value if there is no PKU support or allocation of a key failed.
+// This is also the return value on an error of pkey_alloc() and has the
+// benefit that calling pkey_mprotect() with -1 behaves the same as regular
+// mprotect().
+constexpr int kNoMemoryProtectionKey = -1;
+
+// Permissions for memory protection keys on top of the page's permissions.
+// NOTE: Since there is no executable bit, the executable permission cannot be
+// withdrawn by memory protection keys.
+enum MemoryProtectionKeyPermission {
+  kNoRestrictions = 0,
+  kDisableAccess = 1,
+  kDisableWrite = 2,
+};
+
+// If sys/mman.h has PKEY support (on newer Linux distributions), ensure that
+// our definitions of the permissions is consistent with the ones in glibc.
+#if defined(PKEY_DISABLE_ACCESS)
+STATIC_ASSERT(kDisableAccess == PKEY_DISABLE_ACCESS);
+STATIC_ASSERT(kDisableWrite == PKEY_DISABLE_WRITE);
+#endif
+
+// Allocates a memory protection key on platforms with PKU support, returns
+// {kNoMemoryProtectionKey} on platforms without support or when allocation
+// failed at runtime.
+int AllocateMemoryProtectionKey();
+
+// Frees the given memory protection key, to make it available again for the
+// next call to {AllocateMemoryProtectionKey()}. Note that this does NOT
+// invalidate access rights to pages that are still tied to that key. That is,
+// if the key is reused and pages with that key are still accessable, this might
+// be a security issue. See
+// https://www.gnu.org/software/libc/manual/html_mono/libc.html#Memory-Protection-Keys
+void FreeMemoryProtectionKey(int key);
+
+// Associates a memory protection {key} with the given {region}.
+// If {key} is {kNoMemoryProtectionKey} this behaves like "plain"
+// {SetPermissions()} and associates the default key to the region. That is,
+// explicitly calling with {kNoMemoryProtectionKey} can be used to disassociate
+// any protection key from a region. This also means "plain" {SetPermissions()}
+// disassociates the key from a region, making the key's access restrictions
+// irrelevant/inactive for that region.
+// Returns true if changing permissions and key was successful. (Returns a bool
+// to be consistent with {SetPermissions()}).
+// The {page_permissions} are the permissions of the page, not the key. For
+// changing the permissions of the key, use
+// {SetPermissionsForMemoryProtectionKey()} instead.
+bool SetPermissionsAndMemoryProtectionKey(
+    PageAllocator* page_allocator, base::AddressRegion region,
+    PageAllocator::Permission page_permissions, int key);
+
+// Set the key's permissions and return whether this was successful.
+// Returns false on platforms without PKU support or when the operation failed,
+// e.g., because the key was invalid.
+bool SetPermissionsForMemoryProtectionKey(
+    int key, MemoryProtectionKeyPermission permissions);
+
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_WASM_MEMORY_PROTECTION_KEY_H_
diff --git a/chromium/v8/src/wasm/memory-tracing.cc b/chromium/v8/src/wasm/memory-tracing.cc
index 0d88c4b461e..68310a03f31 100644
--- a/chromium/v8/src/wasm/memory-tracing.cc
+++ b/chromium/v8/src/wasm/memory-tracing.cc
@@ -50,7 +50,7 @@ void TraceMemoryOperation(base::Optional<ExecutionTier> tier,
   }
   const char* eng =
       tier.has_value() ? ExecutionTierToString(tier.value()) : "?";
-  printf("%-11s func:%6d+0x%-6x%s %016" PRIuPTR " val: %s\n", eng, func_index,
+  printf("%-11s func:%6d:0x%-6x%s %016" PRIuPTR " val: %s\n", eng, func_index,
          position, info->is_store ? " store to" : "load from", info->offset,
          value.begin());
 }
diff --git a/chromium/v8/src/wasm/module-compiler.cc b/chromium/v8/src/wasm/module-compiler.cc
index 3b1d8750bac..4742a85070c 100644
--- a/chromium/v8/src/wasm/module-compiler.cc
+++ b/chromium/v8/src/wasm/module-compiler.cc
@@ -32,7 +32,6 @@
 #include "src/wasm/wasm-js.h"
 #include "src/wasm/wasm-limits.h"
 #include "src/wasm/wasm-objects-inl.h"
-#include "src/wasm/wasm-opcodes.h"
 #include "src/wasm/wasm-result.h"
 #include "src/wasm/wasm-serialization.h"
 
@@ -531,17 +530,19 @@ class CompilationStateImpl {
   CompilationStateImpl(const std::shared_ptr<NativeModule>& native_module,
                        std::shared_ptr<Counters> async_counters);
   ~CompilationStateImpl() {
-    DCHECK(compile_job_->IsValid());
-    compile_job_->CancelAndDetach();
+    if (compile_job_->IsValid()) compile_job_->CancelAndDetach();
   }
 
   // Call right after the constructor, after the {compilation_state_} field in
   // the {NativeModule} has been initialized.
   void InitCompileJob(WasmEngine*);
 
-  // Cancel all background compilation, without waiting for compile tasks to
-  // finish.
-  void CancelCompilation();
+  // {kCancelUnconditionally}: Cancel all compilation.
+  // {kCancelInitialCompilation}: Cancel all compilation if initial (baseline)
+  // compilation is not finished yet.
+  enum CancellationPolicy { kCancelUnconditionally, kCancelInitialCompilation };
+  void CancelCompilation(CancellationPolicy);
+
   bool cancelled() const;
 
   // Initialize compilation progress. Set compilation tiers to expect for
@@ -767,7 +768,6 @@ void UpdateFeatureUseCounts(Isolate* isolate, const WasmFeatures& detected) {
   using Feature = v8::Isolate::UseCounterFeature;
   constexpr static std::pair<WasmFeature, Feature> kUseCounters[] = {
       {kFeature_reftypes, Feature::kWasmRefTypes},
-      {kFeature_mv, Feature::kWasmMultiValue},
       {kFeature_simd, Feature::kWasmSimdOpcodes},
       {kFeature_threads, Feature::kWasmThreadOpcodes},
       {kFeature_eh, Feature::kWasmExceptionHandling}};
@@ -791,7 +791,14 @@ void CompilationState::InitCompileJob(WasmEngine* engine) {
   Impl(this)->InitCompileJob(engine);
 }
 
-void CompilationState::CancelCompilation() { Impl(this)->CancelCompilation(); }
+void CompilationState::CancelCompilation() {
+  Impl(this)->CancelCompilation(CompilationStateImpl::kCancelUnconditionally);
+}
+
+void CompilationState::CancelInitialCompilation() {
+  Impl(this)->CancelCompilation(
+      CompilationStateImpl::kCancelInitialCompilation);
+}
 
 void CompilationState::SetError() { Impl(this)->SetError(); }
 
@@ -1202,16 +1209,25 @@ CompilationExecutionResult ExecuteJSToWasmWrapperCompilationUnits(
   std::shared_ptr<JSToWasmWrapperCompilationUnit> wrapper_unit = nullptr;
   int num_processed_wrappers = 0;
 
+  OperationsBarrier::Token wrapper_compilation_token;
+  Isolate* isolate;
+
   {
     BackgroundCompileScope compile_scope(native_module);
     if (compile_scope.cancelled()) return kYield;
     wrapper_unit = compile_scope.compilation_state()
                        ->GetNextJSToWasmWrapperCompilationUnit();
     if (!wrapper_unit) return kNoMoreUnits;
+    isolate = wrapper_unit->isolate();
+    wrapper_compilation_token =
+        compile_scope.native_module()->engine()->StartWrapperCompilation(
+            isolate);
+    if (!wrapper_compilation_token) return kNoMoreUnits;
   }
 
   TRACE_EVENT0("v8.wasm", "wasm.JSToWasmWrapperCompilation");
   while (true) {
+    DCHECK_EQ(isolate, wrapper_unit->isolate());
     wrapper_unit->Execute();
     ++num_processed_wrappers;
     bool yield = delegate && delegate->ShouldYield();
@@ -1829,10 +1845,10 @@ std::shared_ptr<StreamingDecoder> AsyncCompileJob::CreateStreamingDecoder() {
 AsyncCompileJob::~AsyncCompileJob() {
   // Note: This destructor always runs on the foreground thread of the isolate.
   background_task_manager_.CancelAndWait();
-  // If the runtime objects were not created yet, then initial compilation did
-  // not finish yet. In this case we can abort compilation.
-  if (native_module_ && module_object_.is_null()) {
-    Impl(native_module_->compilation_state())->CancelCompilation();
+  // If initial compilation did not finish yet we can abort it.
+  if (native_module_) {
+    Impl(native_module_->compilation_state())
+        ->CancelCompilation(CompilationStateImpl::kCancelInitialCompilation);
   }
   // Tell the streaming decoder that the AsyncCompileJob is not available
   // anymore.
@@ -2459,7 +2475,8 @@ void AsyncStreamingProcessor::FinishAsyncCompileJobWithError(
   // Check if there is already a CompiledModule, in which case we have to clean
   // up the CompilationStateImpl as well.
   if (job_->native_module_) {
-    Impl(job_->native_module_->compilation_state())->CancelCompilation();
+    Impl(job_->native_module_->compilation_state())
+        ->CancelCompilation(CompilationStateImpl::kCancelUnconditionally);
 
     job_->DoSync<AsyncCompileJob::DecodeFail,
                  AsyncCompileJob::kUseExistingForegroundTask>(error);
@@ -2783,13 +2800,22 @@ void CompilationStateImpl::InitCompileJob(WasmEngine* engine) {
                                              async_counters_));
 }
 
-void CompilationStateImpl::CancelCompilation() {
+void CompilationStateImpl::CancelCompilation(
+    CompilationStateImpl::CancellationPolicy cancellation_policy) {
+  base::MutexGuard callbacks_guard(&callbacks_mutex_);
+
+  if (cancellation_policy == kCancelInitialCompilation &&
+      finished_events_.contains(
+          CompilationEvent::kFinishedBaselineCompilation)) {
+    // Initial compilation already finished; cannot be cancelled.
+    return;
+  }
+
   // std::memory_order_relaxed is sufficient because no other state is
   // synchronized with |compile_cancelled_|.
   compile_cancelled_.store(true, std::memory_order_relaxed);
 
   // No more callbacks after abort.
-  base::MutexGuard callbacks_guard(&callbacks_mutex_);
   callbacks_.clear();
 }
 
@@ -3040,7 +3066,8 @@ void CompilationStateImpl::FinalizeJSToWasmWrappers(
                js_to_wasm_wrapper_units_.size());
   CodeSpaceMemoryModificationScope modification_scope(isolate->heap());
   for (auto& unit : js_to_wasm_wrapper_units_) {
-    Handle<Code> code = unit->Finalize(isolate);
+    DCHECK_EQ(isolate, unit->isolate());
+    Handle<Code> code = unit->Finalize();
     int wrapper_index =
         GetExportWrapperIndex(module, unit->sig(), unit->is_import());
     (*export_wrappers_out)->set(wrapper_index, *code);
@@ -3090,7 +3117,8 @@ void CompilationStateImpl::OnFinishedUnits(Vector<WasmCode*> code_vector) {
     DCHECK_NOT_NULL(code);
     DCHECK_LT(code->index(), native_module_->num_functions());
 
-    if (code->index() < native_module_->num_imported_functions()) {
+    if (code->index() <
+        static_cast<int>(native_module_->num_imported_functions())) {
       // Import wrapper.
       DCHECK_EQ(code->tier(), ExecutionTier::kTurbofan);
       outstanding_baseline_units_--;
@@ -3449,7 +3477,8 @@ void CompileJsToWasmWrappers(Isolate* isolate, const WasmModule* module,
   for (auto& pair : compilation_units) {
     JSToWasmWrapperKey key = pair.first;
     JSToWasmWrapperCompilationUnit* unit = pair.second.get();
-    Handle<Code> code = unit->Finalize(isolate);
+    DCHECK_EQ(isolate, unit->isolate());
+    Handle<Code> code = unit->Finalize();
     int wrapper_index = GetExportWrapperIndex(module, &key.second, key.first);
     (*export_wrappers_out)->set(wrapper_index, *code);
     RecordStats(*code, isolate->counters());
diff --git a/chromium/v8/src/wasm/module-decoder.cc b/chromium/v8/src/wasm/module-decoder.cc
index f2c77efb230..be4d8ef833d 100644
--- a/chromium/v8/src/wasm/module-decoder.cc
+++ b/chromium/v8/src/wasm/module-decoder.cc
@@ -34,6 +34,7 @@ namespace {
 constexpr char kNameString[] = "name";
 constexpr char kSourceMappingURLString[] = "sourceMappingURL";
 constexpr char kCompilationHintsString[] = "compilationHints";
+constexpr char kBranchHintsString[] = "branchHints";
 constexpr char kDebugInfoString[] = ".debug_info";
 constexpr char kExternalDebugInfoString[] = "external_debug_info";
 
@@ -95,6 +96,8 @@ const char* SectionName(SectionCode code) {
       return kExternalDebugInfoString;
     case kCompilationHintsSectionCode:
       return kCompilationHintsString;
+    case kBranchHintsSectionCode:
+      return kBranchHintsString;
     default:
       return "<unknown>";
   }
@@ -144,6 +147,7 @@ SectionCode IdentifyUnknownSectionInternal(Decoder* decoder) {
       {StaticCharVector(kNameString), kNameSectionCode},
       {StaticCharVector(kSourceMappingURLString), kSourceMappingURLSectionCode},
       {StaticCharVector(kCompilationHintsString), kCompilationHintsSectionCode},
+      {StaticCharVector(kBranchHintsString), kBranchHintsSectionCode},
       {StaticCharVector(kDebugInfoString), kDebugInfoSectionCode},
       {StaticCharVector(kExternalDebugInfoString),
        kExternalDebugInfoSectionCode}};
@@ -432,6 +436,13 @@ class ModuleDecoderImpl : public Decoder {
         // first occurrence after function section and before code section are
         // ignored.
         break;
+      case kBranchHintsSectionCode:
+        // TODO(yuri): report out of place branch hints section as a
+        // warning.
+        // Be lenient with placement of compilation hints section. All except
+        // first occurrence after function section and before code section are
+        // ignored.
+        break;
       default:
         next_ordered_section_ = section_code + 1;
         break;
@@ -498,6 +509,15 @@ class ModuleDecoderImpl : public Decoder {
           consume_bytes(static_cast<uint32_t>(end_ - start_), nullptr);
         }
         break;
+      case kBranchHintsSectionCode:
+        if (enabled_features_.has_branch_hinting()) {
+          DecodeBranchHintsSection();
+        } else {
+          // Ignore this section when feature was disabled. It is an optional
+          // custom section anyways.
+          consume_bytes(static_cast<uint32_t>(end_ - start_), nullptr);
+        }
+        break;
       case kDataCountSectionCode:
         DecodeDataCountSection();
         break;
@@ -884,50 +904,25 @@ class ModuleDecoderImpl : public Decoder {
     uint32_t element_count =
         consume_count("element count", FLAG_wasm_max_table_size);
 
-    for (uint32_t i = 0; ok() && i < element_count; ++i) {
-      const byte* pos = pc();
-
-      WasmElemSegment::Status status;
-      bool functions_as_elements;
-      uint32_t table_index;
-      WasmInitExpr offset;
-      ValueType type = kWasmBottom;
-      consume_element_segment_header(&status, &functions_as_elements, &type,
-                                     &table_index, &offset);
+    for (uint32_t i = 0; i < element_count; ++i) {
+      bool expressions_as_elements;
+      WasmElemSegment segment =
+          consume_element_segment_header(&expressions_as_elements);
       if (failed()) return;
-      DCHECK_NE(type, kWasmBottom);
-
-      if (status == WasmElemSegment::kStatusActive) {
-        if (table_index >= module_->tables.size()) {
-          errorf(pos, "out of bounds table index %u", table_index);
-          break;
-        }
-        if (!IsSubtypeOf(type, module_->tables[table_index].type,
-                         this->module_.get())) {
-          errorf(pos,
-                 "Invalid element segment. Table %u is not a super-type of %s",
-                 table_index, type.name().c_str());
-          break;
-        }
-      }
+      DCHECK_NE(segment.type, kWasmBottom);
 
       uint32_t num_elem =
           consume_count("number of elements", max_table_init_entries());
-      if (status == WasmElemSegment::kStatusActive) {
-        module_->elem_segments.emplace_back(table_index, std::move(offset));
-      } else {
-        module_->elem_segments.emplace_back(
-            status == WasmElemSegment::kStatusDeclarative);
-      }
 
-      WasmElemSegment* init = &module_->elem_segments.back();
-      init->type = type;
       for (uint32_t j = 0; j < num_elem; j++) {
-        uint32_t index = functions_as_elements ? consume_element_expr()
-                                               : consume_element_func_index();
-        if (failed()) break;
-        init->entries.push_back(index);
+        WasmInitExpr init =
+            expressions_as_elements
+                ? consume_element_expr()
+                : WasmInitExpr::RefFuncConst(consume_element_func_index());
+        if (failed()) return;
+        segment.entries.push_back(std::move(init));
       }
+      module_->elem_segments.push_back(std::move(segment));
     }
   }
 
@@ -1174,6 +1169,82 @@ class ModuleDecoderImpl : public Decoder {
     // consume_bytes(static_cast<uint32_t>(end_ - start_), nullptr);
   }
 
+  void DecodeBranchHintsSection() {
+    TRACE("DecodeBranchHints module+%d\n", static_cast<int>(pc_ - start_));
+    if (!has_seen_unordered_section(kBranchHintsSectionCode)) {
+      set_seen_unordered_section(kBranchHintsSectionCode);
+      // Use an inner decoder so that errors don't fail the outer decoder.
+      Decoder inner(start_, pc_, end_, buffer_offset_);
+      BranchHintInfo branch_hints;
+
+      uint32_t func_count = inner.consume_u32v("number of functions");
+      // Keep track of the previous function index to validate the ordering
+      int64_t last_func_idx = -1;
+      for (uint32_t i = 0; i < func_count; i++) {
+        uint32_t func_idx = inner.consume_u32v("function index");
+        if (int64_t(func_idx) <= last_func_idx) {
+          inner.errorf("Invalid function index: %d", func_idx);
+          break;
+        }
+        last_func_idx = func_idx;
+        uint8_t reserved = inner.consume_u8("reserved byte");
+        if (reserved != 0x0) {
+          inner.errorf("Invalid reserved byte: %#x", reserved);
+          break;
+        }
+        uint32_t num_hints = inner.consume_u32v("number of hints");
+        BranchHintMap func_branch_hints;
+        TRACE("DecodeBranchHints[%d] module+%d\n", func_idx,
+              static_cast<int>(inner.pc() - inner.start()));
+        // Keep track of the previous branch offset to validate the ordering
+        int64_t last_br_off = -1;
+        for (uint32_t j = 0; j < num_hints; ++j) {
+          uint32_t br_dir = inner.consume_u32v("branch direction");
+          uint32_t br_off = inner.consume_u32v("branch instruction offset");
+          if (int64_t(br_off) <= last_br_off) {
+            inner.errorf("Invalid branch offset: %d", br_off);
+            break;
+          }
+          last_br_off = br_off;
+          TRACE("DecodeBranchHints[%d][%d] module+%d\n", func_idx, br_off,
+                static_cast<int>(inner.pc() - inner.start()));
+          WasmBranchHint hint;
+          switch (br_dir) {
+            case 0:
+              hint = WasmBranchHint::kUnlikely;
+              break;
+            case 1:
+              hint = WasmBranchHint::kLikely;
+              break;
+            default:
+              hint = WasmBranchHint::kNoHint;
+              inner.errorf(inner.pc(), "Invalid branch hint %#x", br_dir);
+              break;
+          }
+          if (!inner.ok()) {
+            break;
+          }
+          func_branch_hints.insert(br_off, hint);
+        }
+        if (!inner.ok()) {
+          break;
+        }
+        branch_hints.emplace(func_idx, std::move(func_branch_hints));
+      }
+      // Extra unexpected bytes are an error.
+      if (inner.more()) {
+        inner.errorf("Unexpected extra bytes: %d\n",
+                     static_cast<int>(inner.pc() - inner.start()));
+      }
+      // If everything went well, accept the hints for the module.
+      if (inner.ok()) {
+        module_->branch_hints = std::move(branch_hints);
+      }
+    }
+    // Skip the whole branch hints section in the outer decoder.
+    consume_bytes(static_cast<uint32_t>(end_ - start_), nullptr);
+  }
+
   void DecodeDataCountSection() {
     module_->num_declared_data_segments =
         consume_count("data segments count", kV8MaxWasmDataSegments);
@@ -1911,10 +1982,8 @@ class ModuleDecoderImpl : public Decoder {
     std::vector<ValueType> returns;
 
     // Parse return types.
-    const size_t max_return_count = enabled_features_.has_mv()
-                                        ? kV8MaxWasmFunctionMultiReturns
-                                        : kV8MaxWasmFunctionReturns;
-    uint32_t return_count = consume_count("return count", max_return_count);
+    uint32_t return_count =
+        consume_count("return count", kV8MaxWasmFunctionReturns);
     if (failed()) return nullptr;
     for (uint32_t i = 0; ok() && i < return_count; ++i) {
       returns.push_back(consume_value_type());
@@ -1967,86 +2036,114 @@ class ModuleDecoderImpl : public Decoder {
     return attribute;
   }
 
-  void consume_element_segment_header(WasmElemSegment::Status* status,
-                                      bool* functions_as_elements,
-                                      ValueType* type, uint32_t* table_index,
-                                      WasmInitExpr* offset) {
+  WasmElemSegment consume_element_segment_header(
+      bool* expressions_as_elements) {
     const byte* pos = pc();
-    uint32_t flag = consume_u32v("flag");
 
     // The mask for the bit in the flag which indicates if the segment is
-    // active or not.
-    constexpr uint8_t kIsPassiveMask = 0x01;
-    // The mask for the bit in the flag which indicates if the segment has an
-    // explicit table index field.
-    constexpr uint8_t kHasTableIndexMask = 0x02;
+    // active or not (0 is active).
+    constexpr uint8_t kNonActiveMask = 1 << 0;
+    // The mask for the bit in the flag which indicates:
+    // - for active tables, if the segment has an explicit table index field.
+    // - for non-active tables, whether the table is declarative (vs. passive).
+    constexpr uint8_t kHasTableIndexOrIsDeclarativeMask = 1 << 1;
     // The mask for the bit in the flag which indicates if the functions of this
-    // segment are defined as function indices (=0) or elements(=1).
-    constexpr uint8_t kFunctionsAsElementsMask = 0x04;
-    constexpr uint8_t kFullMask =
-        kIsPassiveMask | kHasTableIndexMask | kFunctionsAsElementsMask;
-
-    bool is_passive = flag & kIsPassiveMask;
-    if (!is_passive) {
-      *status = WasmElemSegment::kStatusActive;
-      if (module_->tables.size() == 0) {
-        error(pc_, "Active element sections require a table");
-      }
-    } else if ((flag & kHasTableIndexMask)) {  // Special bit combination for
-                                               // declarative segments.
-      *status = WasmElemSegment::kStatusDeclarative;
-    } else {
-      *status = WasmElemSegment::kStatusPassive;
+    // segment are defined as function indices (0) or init. expressions (1).
+    constexpr uint8_t kExpressionsAsElementsMask = 1 << 2;
+    constexpr uint8_t kFullMask = kNonActiveMask |
+                                  kHasTableIndexOrIsDeclarativeMask |
+                                  kExpressionsAsElementsMask;
+
+    uint32_t flag = consume_u32v("flag");
+    if ((flag & kFullMask) != flag) {
+      errorf(pos, "illegal flag value %u. Must be between 0 and 7", flag);
+      return {};
     }
-    *functions_as_elements = flag & kFunctionsAsElementsMask;
-    bool has_table_index = (flag & kHasTableIndexMask) &&
-                           *status == WasmElemSegment::kStatusActive;
 
-    if (*status == WasmElemSegment::kStatusDeclarative &&
+    const WasmElemSegment::Status status =
+        (flag & kNonActiveMask) ? (flag & kHasTableIndexOrIsDeclarativeMask)
+                                      ? WasmElemSegment::kStatusDeclarative
+                                      : WasmElemSegment::kStatusPassive
+                                : WasmElemSegment::kStatusActive;
+    if (status == WasmElemSegment::kStatusDeclarative &&
         !enabled_features_.has_reftypes()) {
       error(
           "Declarative element segments require --experimental-wasm-reftypes");
-      return;
-    }
-    if ((flag & kFullMask) != flag) {
-      errorf(pos, "illegal flag value %u. Must be between 0 and 7", flag);
+      return {};
     }
+    const bool is_active = status == WasmElemSegment::kStatusActive;
 
-    if (has_table_index) {
-      *table_index = consume_u32v("table index");
-    } else {
-      *table_index = 0;
-    }
+    *expressions_as_elements = flag & kExpressionsAsElementsMask;
 
-    if (*status == WasmElemSegment::kStatusActive) {
-      *offset = consume_init_expr(module_.get(), kWasmI32,
-                                  module_.get()->globals.size());
-      if (offset->kind() == WasmInitExpr::kNone) {
-        // Failed to parse offset initializer, return early.
-        return;
-      }
+    const bool has_table_index =
+        is_active && (flag & kHasTableIndexOrIsDeclarativeMask);
+    uint32_t table_index = has_table_index ? consume_u32v("table index") : 0;
+    if (is_active && table_index >= module_->tables.size()) {
+      errorf(pos, "out of bounds%s table index %u",
+             has_table_index ? " implicit" : "", table_index);
+      return {};
     }
-
-    if (*status == WasmElemSegment::kStatusActive && !has_table_index) {
-      // Active segments without table indices are a special case for backwards
-      // compatibility. These cases have an implicit element kind or element
-      // type, so we are done already with the segment header.
-      *type = kWasmFuncRef;
-      return;
+    ValueType table_type =
+        is_active ? module_->tables[table_index].type : kWasmBottom;
+
+    WasmInitExpr offset;
+    if (is_active) {
+      offset = consume_init_expr(module_.get(), kWasmI32,
+                                 module_.get()->globals.size());
+      // Failed to parse offset initializer, return early.
+      if (failed()) return {};
+    }
+
+    // Denotes an active segment without table index, type, or element kind.
+    const bool backwards_compatible_mode =
+        is_active && !(flag & kHasTableIndexOrIsDeclarativeMask);
+    ValueType type;
+    if (*expressions_as_elements) {
+      type =
+          backwards_compatible_mode ? kWasmFuncRef : consume_reference_type();
+      if (is_active && !IsSubtypeOf(type, table_type, this->module_.get())) {
+        errorf(pos,
+               "Element segment of type %s is not a subtype of referenced "
+               "table %u (of type %s)",
+               type.name().c_str(), table_index, table_type.name().c_str());
+        return {};
+      }
+    } else {
+      if (!backwards_compatible_mode) {
+        // We have to check that there is an element kind of type Function. All
+        // other element kinds are not valid yet.
+        uint8_t val = consume_u8("element kind");
+        if (static_cast<ImportExportKindCode>(val) != kExternalFunction) {
+          errorf(pos, "illegal element kind 0x%x. Must be 0x%x", val,
+                 kExternalFunction);
+          return {};
+        }
+      }
+      if (!is_active) {
+        // Declarative and passive segments without explicit type are funcref.
+        type = kWasmFuncRef;
+      } else {
+        type = table_type;
+        // Active segments with function indices must reference a function
+        // table. TODO(7748): Add support for anyref tables when we have them.
+        if (!IsSubtypeOf(table_type, kWasmFuncRef, this->module_.get())) {
+          errorf(pos,
+                 "An active element segment with function indices as elements "
+                 "must reference a table of %s. Instead, table %u of type %s "
+                 "is referenced.",
+                 enabled_features_.has_typed_funcref()
+                     ? "a subtype of type funcref"
+                     : "type funcref",
+                 table_index, table_type.name().c_str());
+          return {};
+        }
+      }
     }
 
-    if (*functions_as_elements) {
-      *type = consume_reference_type();
+    if (is_active) {
+      return {type, table_index, std::move(offset)};
     } else {
-      // We have to check that there is an element kind of type Function. All
-      // other element kinds are not valid yet.
-      uint8_t val = consume_u8("element kind");
-      ImportExportKindCode kind = static_cast<ImportExportKindCode>(val);
-      if (kind != kExternalFunction) {
-        errorf(pos, "illegal element kind %x. Must be 0x00", val);
-        return;
-      }
-      *type = kWasmFuncRef;
+      return {type, status == WasmElemSegment::kStatusDeclarative};
     }
   }
 
@@ -2091,32 +2188,49 @@ class ModuleDecoderImpl : public Decoder {
     func->declared = true;
     DCHECK_NE(func, nullptr);
     DCHECK_EQ(index, func->func_index);
-    DCHECK_NE(index, WasmElemSegment::kNullIndex);
     return index;
   }
 
-  uint32_t consume_element_expr() {
-    uint32_t index = WasmElemSegment::kNullIndex;
+  // TODO(manoskouk): When reftypes lands, remove this and use
+  // consume_init_expr() instead.
+  WasmInitExpr consume_element_expr() {
     uint8_t opcode = consume_u8("element opcode");
-    if (failed()) return index;
+    if (failed()) return {};
     switch (opcode) {
       case kExprRefNull: {
         HeapTypeImmediate<kFullValidation> imm(WasmFeatures::All(), this,
                                                this->pc(), module_.get());
         consume_bytes(imm.length, "ref.null immediate");
-        index = WasmElemSegment::kNullIndex;
-        break;
+        expect_u8("end opcode", kExprEnd);
+        return WasmInitExpr::RefNullConst(imm.type.representation());
+      }
+      case kExprRefFunc: {
+        uint32_t index = consume_element_func_index();
+        if (failed()) return {};
+        expect_u8("end opcode", kExprEnd);
+        return WasmInitExpr::RefFuncConst(index);
+      }
+      case kExprGlobalGet: {
+        if (!enabled_features_.has_reftypes()) {
+          errorf(
+              "Unexpected opcode 0x%x in element. Enable with "
+              "--experimental-wasm-reftypes",
+              kExprGlobalGet);
+          return {};
+        }
+        uint32_t index = this->consume_u32v("global index");
+        if (failed()) return {};
+        if (index >= module_->globals.size()) {
+          errorf("Out-of-bounds global index %d", index);
+          return {};
+        }
+        expect_u8("end opcode", kExprEnd);
+        return WasmInitExpr::GlobalGet(index);
       }
-      case kExprRefFunc:
-        index = consume_element_func_index();
-        if (failed()) return index;
-        break;
       default:
         error("invalid opcode in element");
-        break;
+        return {};
     }
-    expect_u8("end opcode", kExprEnd);
-    return index;
   }
 };
 
@@ -2374,8 +2488,7 @@ bool FindNameSection(Decoder* decoder) {
 }  // namespace
 
 void DecodeFunctionNames(const byte* module_start, const byte* module_end,
-                         std::unordered_map<uint32_t, WireBytesRef>* names,
-                         const Vector<const WasmExport> export_table) {
+                         std::unordered_map<uint32_t, WireBytesRef>* names) {
   DCHECK_NOT_NULL(names);
   DCHECK(names->empty());
 
@@ -2407,13 +2520,6 @@ void DecodeFunctionNames(const byte* module_start, const byte* module_end,
       }
     }
   }
-
-  // Extract from export table.
-  for (const WasmExport& exp : export_table) {
-    if (exp.kind == kExternalFunction && names->count(exp.index) == 0) {
-      names->insert(std::make_pair(exp.index, exp.name));
-    }
-  }
 }
 
 NameMap DecodeNameMap(Vector<const uint8_t> module_bytes,
diff --git a/chromium/v8/src/wasm/module-decoder.h b/chromium/v8/src/wasm/module-decoder.h
index 2d33f51f319..2af2760ab4e 100644
--- a/chromium/v8/src/wasm/module-decoder.h
+++ b/chromium/v8/src/wasm/module-decoder.h
@@ -187,13 +187,11 @@ V8_EXPORT_PRIVATE std::vector<CustomSectionOffset> DecodeCustomSections(
 // function.
 AsmJsOffsetsResult DecodeAsmJsOffsets(Vector<const uint8_t> encoded_offsets);
 
-// Decode the function names from the name section and also look at export
-// table. Returns the result as an unordered map. Only names with valid utf8
-// encoding are stored and conflicts are resolved by choosing the last name
-// read.
+// Decode the function names from the name section. Returns the result as an
+// unordered map. Only names with valid utf8 encoding are stored and conflicts
+// are resolved by choosing the last name read.
 void DecodeFunctionNames(const byte* module_start, const byte* module_end,
-                         std::unordered_map<uint32_t, WireBytesRef>* names,
-                         const Vector<const WasmExport> export_table);
+                         std::unordered_map<uint32_t, WireBytesRef>* names);
 
 // Decode the requested subsection of the name section.
 // The result will be empty if no name section is present. On encountering an
diff --git a/chromium/v8/src/wasm/module-instantiate.cc b/chromium/v8/src/wasm/module-instantiate.cc
index f64a657eb8e..7945e798499 100644
--- a/chromium/v8/src/wasm/module-instantiate.cc
+++ b/chromium/v8/src/wasm/module-instantiate.cc
@@ -20,6 +20,7 @@
 #include "src/wasm/wasm-module.h"
 #include "src/wasm/wasm-objects-inl.h"
 #include "src/wasm/wasm-subtyping.h"
+#include "src/wasm/wasm-value.h"
 
 #define TRACE(...)                                      \
   do {                                                  \
@@ -122,16 +123,17 @@ Handle<Map> CreateStructMap(Isolate* isolate, const WasmModule* module,
                             int struct_index, Handle<Map> opt_rtt_parent) {
   const wasm::StructType* type = module->struct_type(struct_index);
   const int inobject_properties = 0;
-  DCHECK_LE(type->total_fields_size(), kMaxInt - WasmStruct::kHeaderSize);
-  const int instance_size =
-      WasmStruct::kHeaderSize + static_cast<int>(type->total_fields_size());
+  // We have to use the variable size sentinel because the instance size
+  // stored directly in a Map is capped at 255 pointer sizes.
+  const int map_instance_size = kVariableSizeSentinel;
+  const int real_instance_size = WasmStruct::Size(type);
   const InstanceType instance_type = WASM_STRUCT_TYPE;
   // TODO(jkummerow): If NO_ELEMENTS were supported, we could use that here.
   const ElementsKind elements_kind = TERMINAL_FAST_ELEMENTS_KIND;
   Handle<WasmTypeInfo> type_info = isolate->factory()->NewWasmTypeInfo(
-      reinterpret_cast<Address>(type), opt_rtt_parent);
+      reinterpret_cast<Address>(type), opt_rtt_parent, real_instance_size);
   Handle<Map> map = isolate->factory()->NewMap(
-      instance_type, instance_size, elements_kind, inobject_properties);
+      instance_type, map_instance_size, elements_kind, inobject_properties);
   map->set_wasm_type_info(*type_info);
   return map;
 }
@@ -141,10 +143,12 @@ Handle<Map> CreateArrayMap(Isolate* isolate, const WasmModule* module,
   const wasm::ArrayType* type = module->array_type(array_index);
   const int inobject_properties = 0;
   const int instance_size = kVariableSizeSentinel;
+  // Wasm Arrays don't have a static instance size.
+  const int cached_instance_size = 0;
   const InstanceType instance_type = WASM_ARRAY_TYPE;
   const ElementsKind elements_kind = TERMINAL_FAST_ELEMENTS_KIND;
   Handle<WasmTypeInfo> type_info = isolate->factory()->NewWasmTypeInfo(
-      reinterpret_cast<Address>(type), opt_rtt_parent);
+      reinterpret_cast<Address>(type), opt_rtt_parent, cached_instance_size);
   Handle<Map> map = isolate->factory()->NewMap(
       instance_type, instance_size, elements_kind, inobject_properties);
   map->set_wasm_type_info(*type_info);
@@ -615,7 +619,7 @@ MaybeHandle<WasmInstanceObject> InstanceBuilder::Build() {
   // list.
   //--------------------------------------------------------------------------
   if (enabled_.has_gc()) {
-    Handle<FixedArray> maps = isolate_->factory()->NewUninitializedFixedArray(
+    Handle<FixedArray> maps = isolate_->factory()->NewFixedArray(
         static_cast<int>(module_->type_kinds.size()));
     for (int map_index = 0;
          map_index < static_cast<int>(module_->type_kinds.size());
@@ -1325,11 +1329,15 @@ bool InstanceBuilder::ProcessImportedGlobal(Handle<WasmInstanceObject> instance,
     // TODO(wasm): Still observable if Function.prototype.valueOf or friends
     // are patched, we might need to check for that as well.
     if (value->IsJSFunction()) value = isolate_->factory()->nan_value();
-    if (value->IsPrimitive() && !value->IsSymbol()) {
-      if (global.type == kWasmI32) {
-        value = Object::ToInt32(isolate_, value).ToHandleChecked();
-      } else {
-        value = Object::ToNumber(isolate_, value).ToHandleChecked();
+    if (value->IsPrimitive()) {
+      MaybeHandle<Object> converted = global.type == kWasmI32
+                                          ? Object::ToInt32(isolate_, value)
+                                          : Object::ToNumber(isolate_, value);
+      if (!converted.ToHandle(&value)) {
+        // Conversion is known to fail for Symbols and BigInts.
+        ReportLinkError("global import must be a number", import_index,
+                        module_name, import_name);
+        return false;
       }
     }
   }
@@ -1903,10 +1911,10 @@ bool LoadElemSegmentImpl(Isolate* isolate, Handle<WasmInstanceObject> instance,
 
   const WasmModule* module = instance->module();
   for (size_t i = 0; i < count; ++i) {
-    uint32_t func_index = elem_segment.entries[src + i];
+    const WasmInitExpr* init = &elem_segment.entries[src + i];
     int entry_index = static_cast<int>(dst + i);
 
-    if (func_index == WasmElemSegment::kNullIndex) {
+    if (init->kind() == WasmInitExpr::kRefNullConst) {
       if (IsSubtypeOf(table_object->type(), kWasmFuncRef, module)) {
         IndirectFunctionTableEntry(instance, table_index, entry_index).clear();
       }
@@ -1915,6 +1923,18 @@ bool LoadElemSegmentImpl(Isolate* isolate, Handle<WasmInstanceObject> instance,
       continue;
     }
 
+    if (init->kind() == WasmInitExpr::kGlobalGet) {
+      WasmTableObject::Set(
+          isolate, table_object, entry_index,
+          WasmInstanceObject::GetGlobalValue(
+              instance, module->globals[init->immediate().index])
+              .to_ref());
+      continue;
+    }
+
+    DCHECK_EQ(init->kind(), WasmInitExpr::kRefFuncConst);
+
+    const uint32_t func_index = init->immediate().index;
     const WasmFunction* function = &module->functions[func_index];
 
     // Update the local dispatch table first if necessary.
diff --git a/chromium/v8/src/wasm/value-type.h b/chromium/v8/src/wasm/value-type.h
index 983e2090b64..7895a731f6a 100644
--- a/chromium/v8/src/wasm/value-type.h
+++ b/chromium/v8/src/wasm/value-type.h
@@ -94,7 +94,7 @@ class HeapType {
   }
 
   explicit constexpr HeapType(Representation repr) : representation_(repr) {
-    CONSTEXPR_DCHECK(is_bottom() || is_valid());
+    DCHECK(is_bottom() || is_valid());
   }
   explicit constexpr HeapType(uint32_t repr)
       : HeapType(static_cast<Representation>(repr)) {}
@@ -116,7 +116,7 @@ class HeapType {
 
   constexpr Representation representation() const { return representation_; }
   constexpr uint32_t ref_index() const {
-    CONSTEXPR_DCHECK(is_index());
+    DCHECK(is_index());
     return representation_;
   }
 
@@ -201,7 +201,7 @@ constexpr int element_size_log2(ValueKind kind) {
   };
 
   int size_log_2 = kElementSizeLog2[kind];
-  CONSTEXPR_DCHECK(size_log_2 >= 0);
+  DCHECK_LE(0, size_log_2);
   return size_log_2;
 }
 
@@ -214,7 +214,7 @@ constexpr int element_size_bytes(ValueKind kind) {
   };
 
   int size = kElementSize[kind];
-  CONSTEXPR_DCHECK(size > 0);
+  DCHECK_LT(0, size);
   return size;
 }
 
@@ -240,7 +240,7 @@ constexpr const char* name(ValueKind kind) {
 }
 
 constexpr MachineType machine_type(ValueKind kind) {
-  CONSTEXPR_DCHECK(kBottom != kind);
+  DCHECK_NE(kBottom, kind);
 
   constexpr MachineType kMachineType[] = {
 #define MACH_TYPE(kind, log2Size, code, machineType, ...) \
@@ -262,7 +262,7 @@ constexpr bool is_rtt(ValueKind kind) {
 }
 
 constexpr bool is_defaultable(ValueKind kind) {
-  CONSTEXPR_DCHECK(kind != kBottom && kind != kVoid);
+  DCHECK(kind != kBottom && kind != kVoid);
   return kind != kRef && !is_rtt(kind);
 }
 
@@ -277,11 +277,11 @@ class ValueType {
   /******************************* Constructors *******************************/
   constexpr ValueType() : bit_field_(KindField::encode(kVoid)) {}
   static constexpr ValueType Primitive(ValueKind kind) {
-    CONSTEXPR_DCHECK(kind == kBottom || kind <= kI16);
+    DCHECK(kind == kBottom || kind <= kI16);
     return ValueType(KindField::encode(kind));
   }
   static constexpr ValueType Ref(uint32_t heap_type, Nullability nullability) {
-    CONSTEXPR_DCHECK(HeapType(heap_type).is_valid());
+    DCHECK(HeapType(heap_type).is_valid());
     return ValueType(
         KindField::encode(nullability == kNullable ? kOptRef : kRef) |
         HeapTypeField::encode(heap_type));
@@ -291,14 +291,14 @@ class ValueType {
   }
 
   static constexpr ValueType Rtt(uint32_t type_index) {
-    CONSTEXPR_DCHECK(HeapType(type_index).is_index());
+    DCHECK(HeapType(type_index).is_index());
     return ValueType(KindField::encode(kRtt) |
                      HeapTypeField::encode(type_index));
   }
 
   static constexpr ValueType Rtt(uint32_t type_index,
                                  uint8_t inheritance_depth) {
-    CONSTEXPR_DCHECK(HeapType(type_index).is_index());
+    DCHECK(HeapType(type_index).is_index());
     return ValueType(KindField::encode(kRttWithDepth) |
                      HeapTypeField::encode(type_index) |
                      DepthField::encode(inheritance_depth));
@@ -340,27 +340,34 @@ class ValueType {
     return is_packed() ? Primitive(kI32) : *this;
   }
 
+  // Returns the version of this type that does not allow null values. Handles
+  // bottom.
+  constexpr ValueType AsNonNull() const {
+    DCHECK(is_object_reference() || is_bottom());
+    return is_nullable() ? Ref(heap_type(), kNonNullable) : *this;
+  }
+
   /***************************** Field Accessors ******************************/
   constexpr ValueKind kind() const { return KindField::decode(bit_field_); }
   constexpr HeapType::Representation heap_representation() const {
-    CONSTEXPR_DCHECK(is_object_reference());
+    DCHECK(is_object_reference());
     return static_cast<HeapType::Representation>(
         HeapTypeField::decode(bit_field_));
   }
   constexpr HeapType heap_type() const {
-    CONSTEXPR_DCHECK(is_object_reference());
+    DCHECK(is_object_reference());
     return HeapType(heap_representation());
   }
   constexpr uint8_t depth() const {
-    CONSTEXPR_DCHECK(has_depth());
+    DCHECK(has_depth());
     return DepthField::decode(bit_field_);
   }
   constexpr uint32_t ref_index() const {
-    CONSTEXPR_DCHECK(has_index());
+    DCHECK(has_index());
     return HeapTypeField::decode(bit_field_);
   }
   constexpr Nullability nullability() const {
-    CONSTEXPR_DCHECK(is_object_reference());
+    DCHECK(is_object_reference());
     return kind() == kOptRef ? kNullable : kNonNullable;
   }
 
@@ -426,7 +433,7 @@ class ValueType {
   // (e.g., Ref(HeapType::kFunc, kNullable).value_type_code will return
   // kFuncrefCode and not kOptRefCode).
   constexpr ValueTypeCode value_type_code() const {
-    CONSTEXPR_DCHECK(kind() != kBottom);
+    DCHECK_NE(kBottom, kind());
     switch (kind()) {
       case kOptRef:
         switch (heap_representation()) {
diff --git a/chromium/v8/src/wasm/wasm-code-manager.cc b/chromium/v8/src/wasm/wasm-code-manager.cc
index d9225103bbd..8907cbab313 100644
--- a/chromium/v8/src/wasm/wasm-code-manager.cc
+++ b/chromium/v8/src/wasm/wasm-code-manager.cc
@@ -26,6 +26,7 @@
 #include "src/wasm/compilation-environment.h"
 #include "src/wasm/function-compiler.h"
 #include "src/wasm/jump-table-assembler.h"
+#include "src/wasm/memory-protection-key.h"
 #include "src/wasm/module-compiler.h"
 #include "src/wasm/wasm-debug.h"
 #include "src/wasm/wasm-engine.h"
@@ -225,8 +226,8 @@ void WasmCode::LogCode(Isolate* isolate, const char* source_url,
 
   ModuleWireBytes wire_bytes(native_module_->wire_bytes());
   const WasmModule* module = native_module_->module();
-  WireBytesRef name_ref = module->lazily_generated_names.LookupFunctionName(
-      wire_bytes, index(), VectorOf(module->export_table));
+  WireBytesRef name_ref =
+      module->lazily_generated_names.LookupFunctionName(wire_bytes, index());
   WasmName name = wire_bytes.GetNameOrNull(name_ref);
 
   const WasmDebugSymbols& debug_symbols = module->debug_symbols;
@@ -502,28 +503,14 @@ int WasmCode::GetSourcePositionBefore(int offset) {
   return position;
 }
 
-WasmCodeAllocator::OptionalLock::~OptionalLock() {
-  if (allocator_) allocator_->mutex_.Unlock();
-}
-
-void WasmCodeAllocator::OptionalLock::Lock(WasmCodeAllocator* allocator) {
-  DCHECK(!is_locked());
-  allocator_ = allocator;
-  allocator->mutex_.Lock();
-}
-
 // static
 constexpr size_t WasmCodeAllocator::kMaxCodeSpaceSize;
 
 WasmCodeAllocator::WasmCodeAllocator(WasmCodeManager* code_manager,
-                                     VirtualMemory code_space,
                                      std::shared_ptr<Counters> async_counters)
     : code_manager_(code_manager),
-      free_code_space_(code_space.region()),
       async_counters_(std::move(async_counters)) {
   owned_code_space_.reserve(4);
-  owned_code_space_.emplace_back(std::move(code_space));
-  async_counters_->wasm_module_num_code_spaces()->AddSample(1);
 }
 
 WasmCodeAllocator::~WasmCodeAllocator() {
@@ -531,9 +518,12 @@ WasmCodeAllocator::~WasmCodeAllocator() {
                                   committed_code_space());
 }
 
-void WasmCodeAllocator::Init(NativeModule* native_module) {
-  DCHECK_EQ(1, owned_code_space_.size());
-  native_module->AddCodeSpace(owned_code_space_[0].region(), {});
+void WasmCodeAllocator::Init(VirtualMemory code_space) {
+  DCHECK(owned_code_space_.empty());
+  DCHECK(free_code_space_.IsEmpty());
+  free_code_space_.Merge(code_space.region());
+  owned_code_space_.emplace_back(std::move(code_space));
+  async_counters_->wasm_module_num_code_spaces()->AddSample(1);
 }
 
 namespace {
@@ -625,18 +615,11 @@ size_t ReservationSize(size_t code_size_estimate, int num_declared_functions,
 
 Vector<byte> WasmCodeAllocator::AllocateForCode(NativeModule* native_module,
                                                 size_t size) {
-  return AllocateForCodeInRegion(native_module, size, kUnrestrictedRegion,
-                                 WasmCodeAllocator::OptionalLock{});
+  return AllocateForCodeInRegion(native_module, size, kUnrestrictedRegion);
 }
 
 Vector<byte> WasmCodeAllocator::AllocateForCodeInRegion(
-    NativeModule* native_module, size_t size, base::AddressRegion region,
-    const WasmCodeAllocator::OptionalLock& optional_lock) {
-  OptionalLock new_lock;
-  if (!optional_lock.is_locked()) new_lock.Lock(this);
-  const auto& locked_lock =
-      optional_lock.is_locked() ? optional_lock : new_lock;
-  DCHECK(locked_lock.is_locked());
+    NativeModule* native_module, size_t size, base::AddressRegion region) {
   DCHECK_EQ(code_manager_, native_module->engine()->code_manager());
   DCHECK_LT(0, size);
   v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
@@ -667,7 +650,7 @@ Vector<byte> WasmCodeAllocator::AllocateForCodeInRegion(
     code_manager_->AssignRange(new_region, native_module);
     free_code_space_.Merge(new_region);
     owned_code_space_.emplace_back(std::move(new_mem));
-    native_module->AddCodeSpace(new_region, locked_lock);
+    native_module->AddCodeSpaceLocked(new_region);
 
     code_space = free_code_space_.Allocate(size);
     DCHECK(!code_space.is_empty());
@@ -703,16 +686,40 @@ Vector<byte> WasmCodeAllocator::AllocateForCodeInRegion(
   return {reinterpret_cast<byte*>(code_space.begin()), code_space.size()};
 }
 
-bool WasmCodeAllocator::SetExecutable(bool executable) {
-  base::MutexGuard lock(&mutex_);
-  if (is_executable_ == executable) return true;
-  TRACE_HEAP("Setting module %p as executable: %d.\n", this, executable);
-
-  v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
+// TODO(dlehmann): Do not return the success as a bool, but instead fail hard.
+// That is, pull the CHECK from {NativeModuleModificationScope} in here and
+// return void.
+// TODO(dlehmann): Ensure {SetWritable(true)} is always paired up with a
+// {SetWritable(false)}, such that eventually the code space is write protected.
+// One solution is to make the API foolproof by hiding {SetWritable()} and
+// allowing change of permissions only through {NativeModuleModificationScope}.
+// TODO(dlehmann): Add tests that ensure the code space is eventually write-
+// protected.
+bool WasmCodeAllocator::SetWritable(bool writable) {
+  // Invariant: `this.writers_count_ > 0` iff `code space has W permission`.
+  // TODO(dlehmann): This is currently not fulfilled before the first call
+  // to SetWritable(false), because initial permissions are RWX.
+  // Fix by setting initial permissions to RX and adding writable permission
+  // where appropriate. See also {WasmCodeManager::Commit()}.
+  if (writable) {
+    if (++writers_count_ > 1) return true;
+  } else {
+    DCHECK_GT(writers_count_, 0);
+    if (--writers_count_ > 0) return true;
+  }
+  writable = writers_count_ > 0;
+  TRACE_HEAP("Setting module %p as writable: %d.\n", this, writable);
 
   if (FLAG_wasm_write_protect_code_memory) {
+    v8::PageAllocator* page_allocator = GetPlatformPageAllocator();
+
+    // Due to concurrent compilation and execution, we always need the execute
+    // permission, however during codegen we additionally need to write.
+    // Hence this does not actually achieve write-xor-execute, but merely
+    // "always-execute" with "no-write-eventually".
     PageAllocator::Permission permission =
-        executable ? PageAllocator::kReadExecute : PageAllocator::kReadWrite;
+        writable ? PageAllocator::kReadWriteExecute
+                 : PageAllocator::kReadExecute;
 #if V8_OS_WIN
     // On windows, we need to switch permissions per separate virtual memory
     // reservation.
@@ -725,8 +732,8 @@ bool WasmCodeAllocator::SetExecutable(bool executable) {
                           permission)) {
         return false;
       }
-      TRACE_HEAP("Set %p:%p to executable:%d\n", vmem.address(), vmem.end(),
-                 executable);
+      TRACE_HEAP("Set %p:%p to writable:%d\n", vmem.address(), vmem.end(),
+                 writable);
     }
 #else   // V8_OS_WIN
     size_t commit_page_size = page_allocator->CommitPageSize();
@@ -738,21 +745,46 @@ bool WasmCodeAllocator::SetExecutable(bool executable) {
                           permission)) {
         return false;
       }
-      TRACE_HEAP("Set 0x%" PRIxPTR ":0x%" PRIxPTR " to executable:%d\n",
-                 region.begin(), region.end(), executable);
+      TRACE_HEAP("Set 0x%" PRIxPTR ":0x%" PRIxPTR " to writable:%d\n",
+                 region.begin(), region.end(), writable);
     }
 #endif  // V8_OS_WIN
   }
-  is_executable_ = executable;
   return true;
 }
 
+bool WasmCodeAllocator::SetThreadWritable(bool writable) {
+  static thread_local int writable_nesting_level = 0;
+  if (writable) {
+    if (++writable_nesting_level > 1) return true;
+  } else {
+    DCHECK_GT(writable_nesting_level, 0);
+    if (--writable_nesting_level > 0) return true;
+  }
+  writable = writable_nesting_level > 0;
+
+  int key = code_manager_->memory_protection_key_;
+
+  MemoryProtectionKeyPermission permissions =
+      writable ? kNoRestrictions : kDisableWrite;
+
+  TRACE_HEAP("Setting memory protection key %d to writable: %d.\n", key,
+             writable);
+  return SetPermissionsForMemoryProtectionKey(key, permissions);
+}
+
 void WasmCodeAllocator::FreeCode(Vector<WasmCode* const> codes) {
   // Zap code area and collect freed code regions.
   DisjointAllocationPool freed_regions;
   size_t code_size = 0;
   CODE_SPACE_WRITE_SCOPE
   for (WasmCode* code : codes) {
+    // TODO(dlehmann): Pull the {NativeModuleModificationScope} out of the loop.
+    // However, its constructor requires a {NativeModule}.
+    // Can be fixed if {NativeModuleModificationScope()} is changed to take
+    // only a {WasmCodeAllocator} in its constructor.
+    NativeModuleModificationScope native_module_modification_scope(
+        code->native_module());
     ZapCode(code->instruction_start(), code->instructions().size());
     FlushInstructionCache(code->instruction_start(),
                           code->instructions().size());
@@ -768,19 +800,16 @@ void WasmCodeAllocator::FreeCode(Vector<WasmCode* const> codes) {
   DisjointAllocationPool regions_to_decommit;
   PageAllocator* allocator = GetPlatformPageAllocator();
   size_t commit_page_size = allocator->CommitPageSize();
-  {
-    base::MutexGuard guard(&mutex_);
-    for (auto region : freed_regions.regions()) {
-      auto merged_region = freed_code_space_.Merge(region);
-      Address discard_start =
-          std::max(RoundUp(merged_region.begin(), commit_page_size),
-                   RoundDown(region.begin(), commit_page_size));
-      Address discard_end =
-          std::min(RoundDown(merged_region.end(), commit_page_size),
-                   RoundUp(region.end(), commit_page_size));
-      if (discard_start >= discard_end) continue;
-      regions_to_decommit.Merge({discard_start, discard_end - discard_start});
-    }
+  for (auto region : freed_regions.regions()) {
+    auto merged_region = freed_code_space_.Merge(region);
+    Address discard_start =
+        std::max(RoundUp(merged_region.begin(), commit_page_size),
+                 RoundDown(region.begin(), commit_page_size));
+    Address discard_end =
+        std::min(RoundDown(merged_region.end(), commit_page_size),
+                 RoundUp(region.end(), commit_page_size));
+    if (discard_start >= discard_end) continue;
+    regions_to_decommit.Merge({discard_start, discard_end - discard_start});
   }
 
   for (auto region : regions_to_decommit.regions()) {
@@ -795,7 +824,6 @@ void WasmCodeAllocator::FreeCode(Vector<WasmCode* const> codes) {
 }
 
 size_t WasmCodeAllocator::GetNumCodeSpaces() const {
-  base::MutexGuard lock(&mutex_);
   return owned_code_space_.size();
 }
 
@@ -809,8 +837,7 @@ NativeModule::NativeModule(WasmEngine* engine, const WasmFeatures& enabled,
                            std::shared_ptr<NativeModule>* shared_this)
     : engine_(engine),
       engine_scope_(engine->GetBarrierForBackgroundCompile()->TryLock()),
-      code_allocator_(engine->code_manager(), std::move(code_space),
-                      async_counters),
+      code_allocator_(engine->code_manager(), async_counters),
       enabled_features_(enabled),
       module_(std::move(module)),
       import_wrapper_cache_(std::unique_ptr<WasmImportWrapperCache>(
@@ -838,7 +865,14 @@ NativeModule::NativeModule(WasmEngine* engine, const WasmFeatures& enabled,
     std::fill_n(num_liftoff_function_calls_.get(),
                 module_->num_declared_functions, kCounterStart);
   }
-  code_allocator_.Init(this);
+  // Even though there cannot be another thread using this object (since we are
+  // just constructing it), we need to hold the mutex to fulfill the
+  // precondition of {WasmCodeAllocator::Init}, which calls
+  // {NativeModule::AddCodeSpaceLocked}.
+  base::RecursiveMutexGuard guard{&allocation_mutex_};
+  auto initial_region = code_space.region();
+  code_allocator_.Init(std::move(code_space));
+  AddCodeSpaceLocked(initial_region);
 }
 
 void NativeModule::ReserveCodeTableForTesting(uint32_t max_functions) {
@@ -852,16 +886,13 @@ void NativeModule::ReserveCodeTableForTesting(uint32_t max_functions) {
   code_table_ = std::move(new_table);
 
   base::AddressRegion single_code_space_region;
-  {
-    base::MutexGuard guard(&allocation_mutex_);
-    CHECK_EQ(1, code_space_data_.size());
-    single_code_space_region = code_space_data_[0].region;
-  }
+  base::RecursiveMutexGuard guard(&allocation_mutex_);
+  CHECK_EQ(1, code_space_data_.size());
+  single_code_space_region = code_space_data_[0].region;
   // Re-allocate jump table.
-  main_jump_table_ = CreateEmptyJumpTableInRegion(
+  main_jump_table_ = CreateEmptyJumpTableInRegionLocked(
       JumpTableAssembler::SizeForNumberOfSlots(max_functions),
-      single_code_space_region, WasmCodeAllocator::OptionalLock{});
-  base::MutexGuard guard(&allocation_mutex_);
+      single_code_space_region);
   code_space_data_[0].jump_table = main_jump_table_;
 }
 
@@ -879,7 +910,7 @@ void NativeModule::LogWasmCodes(Isolate* isolate, Script script) {
 
   // Log all owned code, not just the current entries in the code table. This
   // will also include import wrappers.
-  base::MutexGuard lock(&allocation_mutex_);
+  base::RecursiveMutexGuard lock(&allocation_mutex_);
   for (auto& owned_entry : owned_code_) {
     owned_entry.second->LogCode(isolate, source_url.get(), script.id());
   }
@@ -890,11 +921,12 @@ void NativeModule::LogWasmCodes(Isolate* isolate, Script script) {
 
 CompilationEnv NativeModule::CreateCompilationEnv() const {
   return {module(), use_trap_handler_, kRuntimeExceptionSupport,
-          enabled_features_, kNoLowerSimd};
+          enabled_features_};
 }
 
 WasmCode* NativeModule::AddCodeForTesting(Handle<Code> code) {
   CODE_SPACE_WRITE_SCOPE
+  NativeModuleModificationScope native_module_modification_scope(this);
   const size_t relocation_size = code->relocation_size();
   OwnedVector<byte> reloc_info;
   if (relocation_size > 0) {
@@ -929,6 +961,7 @@ WasmCode* NativeModule::AddCodeForTesting(Handle<Code> code) {
   const int constant_pool_offset = base_offset + code->constant_pool_offset();
   const int code_comments_offset = base_offset + code->code_comments_offset();
 
+  base::RecursiveMutexGuard guard{&allocation_mutex_};
   Vector<uint8_t> dst_code_bytes =
       code_allocator_.AllocateForCode(this, instructions.size());
   base::Memcpy(dst_code_bytes.begin(), instructions.begin(),
@@ -940,7 +973,7 @@ WasmCode* NativeModule::AddCodeForTesting(Handle<Code> code) {
   int mode_mask =
       RelocInfo::kApplyMask | RelocInfo::ModeMask(RelocInfo::WASM_STUB_CALL);
   auto jump_tables_ref =
-      FindJumpTablesForRegion(base::AddressRegionOf(dst_code_bytes));
+      FindJumpTablesForRegionLocked(base::AddressRegionOf(dst_code_bytes));
   Address dst_code_addr = reinterpret_cast<Address>(dst_code_bytes.begin());
   Address constant_pool_start = dst_code_addr + constant_pool_offset;
   RelocIterator orig_it(*code, mode_mask);
@@ -982,7 +1015,7 @@ WasmCode* NativeModule::AddCodeForTesting(Handle<Code> code) {
   new_code->MaybePrint();
   new_code->Validate();
 
-  return PublishCode(std::move(new_code));
+  return PublishCodeLocked(std::move(new_code));
 }
 
 void NativeModule::UseLazyStub(uint32_t func_index) {
@@ -990,25 +1023,24 @@ void NativeModule::UseLazyStub(uint32_t func_index) {
   DCHECK_LT(func_index,
             module_->num_imported_functions + module_->num_declared_functions);
 
+  base::RecursiveMutexGuard guard(&allocation_mutex_);
   if (!lazy_compile_table_) {
     uint32_t num_slots = module_->num_declared_functions;
     WasmCodeRefScope code_ref_scope;
     CODE_SPACE_WRITE_SCOPE
-    base::AddressRegion single_code_space_region;
-    {
-      base::MutexGuard guard(&allocation_mutex_);
-      DCHECK_EQ(1, code_space_data_.size());
-      single_code_space_region = code_space_data_[0].region;
-    }
-    lazy_compile_table_ = CreateEmptyJumpTableInRegion(
+    NativeModuleModificationScope native_module_modification_scope(this);
+    DCHECK_EQ(1, code_space_data_.size());
+    base::AddressRegion single_code_space_region = code_space_data_[0].region;
+    lazy_compile_table_ = CreateEmptyJumpTableInRegionLocked(
         JumpTableAssembler::SizeForNumberOfLazyFunctions(num_slots),
-        single_code_space_region, WasmCodeAllocator::OptionalLock{});
+        single_code_space_region);
     JumpTableAssembler::GenerateLazyCompileTable(
         lazy_compile_table_->instruction_start(), num_slots,
         module_->num_imported_functions,
-        GetNearRuntimeStubEntry(WasmCode::kWasmCompileLazy,
-                                FindJumpTablesForRegion(base::AddressRegionOf(
-                                    lazy_compile_table_->instructions()))));
+        GetNearRuntimeStubEntry(
+            WasmCode::kWasmCompileLazy,
+            FindJumpTablesForRegionLocked(
+                base::AddressRegionOf(lazy_compile_table_->instructions()))));
   }
 
   // Add jump table entry for jump to the lazy compile stub.
@@ -1017,7 +1049,6 @@ void NativeModule::UseLazyStub(uint32_t func_index) {
   Address lazy_compile_target =
       lazy_compile_table_->instruction_start() +
       JumpTableAssembler::LazyCompileSlotIndexToOffset(slot_index);
-  base::MutexGuard guard(&allocation_mutex_);
   PatchJumpTablesLocked(slot_index, lazy_compile_target);
 }
 
@@ -1026,10 +1057,14 @@ std::unique_ptr<WasmCode> NativeModule::AddCode(
     int tagged_parameter_slots, Vector<const byte> protected_instructions_data,
     Vector<const byte> source_position_table, WasmCode::Kind kind,
     ExecutionTier tier, ForDebugging for_debugging) {
-  Vector<byte> code_space =
-      code_allocator_.AllocateForCode(this, desc.instr_size);
-  auto jump_table_ref =
-      FindJumpTablesForRegion(base::AddressRegionOf(code_space));
+  Vector<byte> code_space;
+  NativeModule::JumpTablesRef jump_table_ref;
+  {
+    base::RecursiveMutexGuard guard{&allocation_mutex_};
+    code_space = code_allocator_.AllocateForCode(this, desc.instr_size);
+    jump_table_ref =
+        FindJumpTablesForRegionLocked(base::AddressRegionOf(code_space));
+  }
   return AddCodeWithCodeSpace(index, desc, stack_slots, tagged_parameter_slots,
                               protected_instructions_data,
                               source_position_table, kind, tier, for_debugging,
@@ -1057,6 +1092,7 @@ std::unique_ptr<WasmCode> NativeModule::AddCodeWithCodeSpace(
   const int instr_size = desc.instr_size;
 
   CODE_SPACE_WRITE_SCOPE
+  NativeModuleModificationScope native_module_modification_scope(this);
   base::Memcpy(dst_code_bytes.begin(), desc.buffer,
                static_cast<size_t>(desc.instr_size));
 
@@ -1107,7 +1143,7 @@ std::unique_ptr<WasmCode> NativeModule::AddCodeWithCodeSpace(
 WasmCode* NativeModule::PublishCode(std::unique_ptr<WasmCode> code) {
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.wasm.detailed"),
                "wasm.PublishCode");
-  base::MutexGuard lock(&allocation_mutex_);
+  base::RecursiveMutexGuard lock(&allocation_mutex_);
   return PublishCodeLocked(std::move(code));
 }
 
@@ -1117,7 +1153,7 @@ std::vector<WasmCode*> NativeModule::PublishCode(
                "wasm.PublishCode", "number", codes.size());
   std::vector<WasmCode*> published_code;
   published_code.reserve(codes.size());
-  base::MutexGuard lock(&allocation_mutex_);
+  base::RecursiveMutexGuard lock(&allocation_mutex_);
   // The published code is put into the top-most surrounding {WasmCodeRefScope}.
   for (auto& code : codes) {
     published_code.push_back(PublishCodeLocked(std::move(code)));
@@ -1138,8 +1174,7 @@ WasmCode::Kind GetCodeKind(const WasmCompilationResult& result) {
 
 WasmCode* NativeModule::PublishCodeLocked(
     std::unique_ptr<WasmCode> owned_code) {
-  // The caller must hold the {allocation_mutex_}, thus we fail to lock it here.
-  DCHECK(!allocation_mutex_.TryLock());
+  allocation_mutex_.AssertHeld();
 
   WasmCode* code = owned_code.get();
   new_owned_code_.emplace_back(std::move(owned_code));
@@ -1148,7 +1183,7 @@ WasmCode* NativeModule::PublishCodeLocked(
   // guaranteed to be valid.
   WasmCodeRefScope::AddRef(code);
 
-  if (code->IsAnonymous() || code->index() < module_->num_imported_functions) {
+  if (code->index() < static_cast<int>(module_->num_imported_functions)) {
     return code;
   }
 
@@ -1208,7 +1243,7 @@ WasmCode* NativeModule::PublishCodeLocked(
 }
 
 void NativeModule::ReinstallDebugCode(WasmCode* code) {
-  base::MutexGuard lock(&allocation_mutex_);
+  base::RecursiveMutexGuard lock(&allocation_mutex_);
 
   DCHECK_EQ(this, code->native_module());
   DCHECK_EQ(kWithBreakpoints, code->for_debugging());
@@ -1230,9 +1265,14 @@ void NativeModule::ReinstallDebugCode(WasmCode* code) {
   PatchJumpTablesLocked(slot_idx, code->instruction_start());
 }
 
-Vector<uint8_t> NativeModule::AllocateForDeserializedCode(
-    size_t total_code_size) {
-  return code_allocator_.AllocateForCode(this, total_code_size);
+std::pair<Vector<uint8_t>, NativeModule::JumpTablesRef>
+NativeModule::AllocateForDeserializedCode(size_t total_code_size) {
+  base::RecursiveMutexGuard guard{&allocation_mutex_};
+  Vector<uint8_t> code_space =
+      code_allocator_.AllocateForCode(this, total_code_size);
+  auto jump_tables =
+      FindJumpTablesForRegionLocked(base::AddressRegionOf(code_space));
+  return {code_space, jump_tables};
 }
 
 std::unique_ptr<WasmCode> NativeModule::AddDeserializedCode(
@@ -1253,7 +1293,7 @@ std::unique_ptr<WasmCode> NativeModule::AddDeserializedCode(
 }
 
 std::vector<WasmCode*> NativeModule::SnapshotCodeTable() const {
-  base::MutexGuard lock(&allocation_mutex_);
+  base::RecursiveMutexGuard lock(&allocation_mutex_);
   WasmCode** start = code_table_.get();
   WasmCode** end = start + module_->num_declared_functions;
   for (WasmCode* code : VectorOf(start, end - start)) {
@@ -1263,19 +1303,19 @@ std::vector<WasmCode*> NativeModule::SnapshotCodeTable() const {
 }
 
 WasmCode* NativeModule::GetCode(uint32_t index) const {
-  base::MutexGuard guard(&allocation_mutex_);
+  base::RecursiveMutexGuard guard(&allocation_mutex_);
   WasmCode* code = code_table_[declared_function_index(module(), index)];
   if (code) WasmCodeRefScope::AddRef(code);
   return code;
 }
 
 bool NativeModule::HasCode(uint32_t index) const {
-  base::MutexGuard guard(&allocation_mutex_);
+  base::RecursiveMutexGuard guard(&allocation_mutex_);
   return code_table_[declared_function_index(module(), index)] != nullptr;
 }
 
 bool NativeModule::HasCodeWithTier(uint32_t index, ExecutionTier tier) const {
-  base::MutexGuard guard(&allocation_mutex_);
+  base::RecursiveMutexGuard guard(&allocation_mutex_);
   return code_table_[declared_function_index(module(), index)] != nullptr &&
          code_table_[declared_function_index(module(), index)]->tier() == tier;
 }
@@ -1289,16 +1329,17 @@ WasmModuleSourceMap* NativeModule::GetWasmSourceMap() const {
   return source_map_.get();
 }
 
-WasmCode* NativeModule::CreateEmptyJumpTableInRegion(
-    int jump_table_size, base::AddressRegion region,
-    const WasmCodeAllocator::OptionalLock& allocator_lock) {
+WasmCode* NativeModule::CreateEmptyJumpTableInRegionLocked(
+    int jump_table_size, base::AddressRegion region) {
+  allocation_mutex_.AssertHeld();
   // Only call this if we really need a jump table.
   DCHECK_LT(0, jump_table_size);
-  Vector<uint8_t> code_space = code_allocator_.AllocateForCodeInRegion(
-      this, jump_table_size, region, allocator_lock);
+  Vector<uint8_t> code_space =
+      code_allocator_.AllocateForCodeInRegion(this, jump_table_size, region);
   DCHECK(!code_space.empty());
   UpdateCodeSize(jump_table_size, ExecutionTier::kNone, kNoDebugging);
   CODE_SPACE_WRITE_SCOPE
+  NativeModuleModificationScope native_module_modification_scope(this);
   ZapCode(reinterpret_cast<Address>(code_space.begin()), code_space.size());
   std::unique_ptr<WasmCode> code{
       new WasmCode{this,                  // native_module
@@ -1317,7 +1358,7 @@ WasmCode* NativeModule::CreateEmptyJumpTableInRegion(
                    WasmCode::kJumpTable,  // kind
                    ExecutionTier::kNone,  // tier
                    kNoDebugging}};        // for_debugging
-  return PublishCode(std::move(code));
+  return PublishCodeLocked(std::move(code));
 }
 
 void NativeModule::UpdateCodeSize(size_t size, ExecutionTier tier,
@@ -1330,10 +1371,10 @@ void NativeModule::UpdateCodeSize(size_t size, ExecutionTier tier,
 }
 
 void NativeModule::PatchJumpTablesLocked(uint32_t slot_index, Address target) {
-  // The caller must hold the {allocation_mutex_}, thus we fail to lock it here.
-  DCHECK(!allocation_mutex_.TryLock());
+  allocation_mutex_.AssertHeld();
 
   CODE_SPACE_WRITE_SCOPE
+  NativeModuleModificationScope native_module_modification_scope(this);
   for (auto& code_space_data : code_space_data_) {
     DCHECK_IMPLIES(code_space_data.jump_table, code_space_data.far_jump_table);
     if (!code_space_data.jump_table) continue;
@@ -1343,8 +1384,7 @@ void NativeModule::PatchJumpTablesLocked(uint32_t slot_index, Address target) {
 
 void NativeModule::PatchJumpTableLocked(const CodeSpaceData& code_space_data,
                                         uint32_t slot_index, Address target) {
-  // The caller must hold the {allocation_mutex_}, thus we fail to lock it here.
-  DCHECK(!allocation_mutex_.TryLock());
+  allocation_mutex_.AssertHeld();
 
   DCHECK_NOT_NULL(code_space_data.jump_table);
   DCHECK_NOT_NULL(code_space_data.far_jump_table);
@@ -1369,9 +1409,9 @@ void NativeModule::PatchJumpTableLocked(const CodeSpaceData& code_space_data,
                                          target);
 }
 
-void NativeModule::AddCodeSpace(
-    base::AddressRegion region,
-    const WasmCodeAllocator::OptionalLock& allocator_lock) {
+void NativeModule::AddCodeSpaceLocked(base::AddressRegion region) {
+  allocation_mutex_.AssertHeld();
+
   // Each code space must be at least twice as large as the overhead per code
   // space. Otherwise, we are wasting too much memory.
   DCHECK_GE(region.size(),
@@ -1387,8 +1427,8 @@ void NativeModule::AddCodeSpace(
           ->CanRegisterUnwindInfoForNonABICompliantCodeRange()) {
     size_t size = Heap::GetCodeRangeReservedAreaSize();
     DCHECK_LT(0, size);
-    Vector<byte> padding = code_allocator_.AllocateForCodeInRegion(
-        this, size, region, allocator_lock);
+    Vector<byte> padding =
+        code_allocator_.AllocateForCodeInRegion(this, size, region);
     CHECK_EQ(reinterpret_cast<Address>(padding.begin()), region.begin());
     win64_unwindinfo::RegisterNonABICompliantCodeRange(
         reinterpret_cast<void*>(region.begin()), region.size());
@@ -1397,28 +1437,29 @@ void NativeModule::AddCodeSpace(
 
   WasmCodeRefScope code_ref_scope;
   CODE_SPACE_WRITE_SCOPE
+  NativeModuleModificationScope native_module_modification_scope(this);
   WasmCode* jump_table = nullptr;
   WasmCode* far_jump_table = nullptr;
   const uint32_t num_wasm_functions = module_->num_declared_functions;
   const bool is_first_code_space = code_space_data_.empty();
   // We always need a far jump table, because it contains the runtime stubs.
-  const bool needs_far_jump_table = !FindJumpTablesForRegion(region).is_valid();
+  const bool needs_far_jump_table =
+      !FindJumpTablesForRegionLocked(region).is_valid();
   const bool needs_jump_table = num_wasm_functions > 0 && needs_far_jump_table;
 
   if (needs_jump_table) {
-    jump_table = CreateEmptyJumpTableInRegion(
-        JumpTableAssembler::SizeForNumberOfSlots(num_wasm_functions), region,
-        allocator_lock);
+    jump_table = CreateEmptyJumpTableInRegionLocked(
+        JumpTableAssembler::SizeForNumberOfSlots(num_wasm_functions), region);
     CHECK(region.contains(jump_table->instruction_start()));
   }
 
   if (needs_far_jump_table) {
     int num_function_slots = NumWasmFunctionsInFarJumpTable(num_wasm_functions);
-    far_jump_table = CreateEmptyJumpTableInRegion(
+    far_jump_table = CreateEmptyJumpTableInRegionLocked(
         JumpTableAssembler::SizeForNumberOfFarJumpSlots(
             WasmCode::kRuntimeStubCount,
             NumWasmFunctionsInFarJumpTable(num_function_slots)),
-        region, allocator_lock);
+        region);
     CHECK(region.contains(far_jump_table->instruction_start()));
     EmbeddedData embedded_data = EmbeddedData::FromBlob();
 #define RUNTIME_STUB(Name) Builtins::k##Name,
@@ -1446,7 +1487,6 @@ void NativeModule::AddCodeSpace(
     main_far_jump_table_ = far_jump_table;
   }
 
-  base::MutexGuard guard(&allocation_mutex_);
   code_space_data_.push_back(CodeSpaceData{region, jump_table, far_jump_table});
 
   if (jump_table && !is_first_code_space) {
@@ -1499,8 +1539,7 @@ void NativeModule::SetWireBytes(OwnedVector<const uint8_t> wire_bytes) {
 }
 
 void NativeModule::TransferNewOwnedCodeLocked() const {
-  // The caller holds the allocation mutex.
-  DCHECK(!allocation_mutex_.TryLock());
+  allocation_mutex_.AssertHeld();
   DCHECK(!new_owned_code_.empty());
   // Sort the {new_owned_code_} vector reversed, such that the position of the
   // previously inserted element can be used as a hint for the next element. If
@@ -1524,8 +1563,7 @@ void NativeModule::TransferNewOwnedCodeLocked() const {
 }
 
 void NativeModule::InsertToCodeCache(WasmCode* code) {
-  // The caller holds {allocation_mutex_}.
-  DCHECK(!allocation_mutex_.TryLock());
+  allocation_mutex_.AssertHeld();
   DCHECK_NOT_NULL(cached_code_);
   if (code->IsAnonymous()) return;
   // Only cache Liftoff debugging code or TurboFan code (no breakpoints or
@@ -1541,7 +1579,7 @@ void NativeModule::InsertToCodeCache(WasmCode* code) {
 }
 
 WasmCode* NativeModule::Lookup(Address pc) const {
-  base::MutexGuard lock(&allocation_mutex_);
+  base::RecursiveMutexGuard lock(&allocation_mutex_);
   if (!new_owned_code_.empty()) TransferNewOwnedCodeLocked();
   auto iter = owned_code_.upper_bound(pc);
   if (iter == owned_code_.begin()) return nullptr;
@@ -1566,8 +1604,9 @@ Address NativeModule::GetCallTargetForFunction(uint32_t func_index) const {
   return main_jump_table_->instruction_start() + slot_offset;
 }
 
-NativeModule::JumpTablesRef NativeModule::FindJumpTablesForRegion(
+NativeModule::JumpTablesRef NativeModule::FindJumpTablesForRegionLocked(
     base::AddressRegion code_region) const {
+  allocation_mutex_.AssertHeld();
   auto jump_table_usable = [code_region](const WasmCode* jump_table) {
     Address table_start = jump_table->instruction_start();
     Address table_end = table_start + jump_table->instructions().size();
@@ -1583,18 +1622,6 @@ NativeModule::JumpTablesRef NativeModule::FindJumpTablesForRegion(
     return max_distance <= WasmCodeAllocator::kMaxCodeSpaceSize;
   };
 
-  // Fast path: Try to use {main_jump_table_} and {main_far_jump_table_}.
-  // Access to these fields is possible without locking, since these fields are
-  // initialized on construction of the {NativeModule}.
-  if (main_far_jump_table_ && jump_table_usable(main_far_jump_table_) &&
-      (main_jump_table_ == nullptr || jump_table_usable(main_jump_table_))) {
-    return {
-        main_jump_table_ ? main_jump_table_->instruction_start() : kNullAddress,
-        main_far_jump_table_->instruction_start()};
-  }
-
-  // Otherwise, take the mutex and look for another suitable jump table.
-  base::MutexGuard guard(&allocation_mutex_);
   for (auto& code_space_data : code_space_data_) {
     DCHECK_IMPLIES(code_space_data.jump_table, code_space_data.far_jump_table);
     if (!code_space_data.far_jump_table) continue;
@@ -1645,7 +1672,7 @@ uint32_t NativeModule::GetFunctionIndexFromJumpTableSlot(
 }
 
 WasmCode::RuntimeStubId NativeModule::GetRuntimeStubId(Address target) const {
-  base::MutexGuard guard(&allocation_mutex_);
+  base::RecursiveMutexGuard guard(&allocation_mutex_);
 
   for (auto& code_space_data : code_space_data_) {
     if (code_space_data.far_jump_table != nullptr &&
@@ -1679,10 +1706,22 @@ NativeModule::~NativeModule() {
 
 WasmCodeManager::WasmCodeManager(size_t max_committed)
     : max_committed_code_space_(max_committed),
-      critical_committed_code_space_(max_committed / 2) {
+      critical_committed_code_space_(max_committed / 2),
+      memory_protection_key_(FLAG_wasm_memory_protection_keys
+                                 ? AllocateMemoryProtectionKey()
+                                 : kNoMemoryProtectionKey) {
   DCHECK_LE(max_committed, FLAG_wasm_max_code_space * MB);
 }
 
+WasmCodeManager::~WasmCodeManager() {
+  // No more committed code space.
+  DCHECK_EQ(0, total_committed_code_space_.load());
+
+  if (FLAG_wasm_memory_protection_keys) {
+    FreeMemoryProtectionKey(memory_protection_key_);
+  }
+}
+
 #if defined(V8_OS_WIN64)
 bool WasmCodeManager::CanRegisterUnwindInfoForNonABICompliantCodeRange() const {
   return win64_unwindinfo::CanRegisterUnwindInfoForNonABICompliantCodeRange() &&
@@ -1711,16 +1750,38 @@ void WasmCodeManager::Commit(base::AddressRegion region) {
       break;
     }
   }
-  PageAllocator::Permission permission = FLAG_wasm_write_protect_code_memory
-                                             ? PageAllocator::kReadWrite
-                                             : PageAllocator::kReadWriteExecute;
-
-  TRACE_HEAP("Setting rw permissions for 0x%" PRIxPTR ":0x%" PRIxPTR "\n",
-             region.begin(), region.end());
+  // Even when we employ W^X with FLAG_wasm_write_protect_code_memory == true,
+  // code pages need to be initially allocated with RWX permission because of
+  // concurrent compilation/execution. For this reason there is no distinction
+  // here based on FLAG_wasm_write_protect_code_memory.
+  // TODO(dlehmann): This allocates initially as writable and executable, and
+  // as such is not safe-by-default. In particular, if
+  // {WasmCodeAllocator::SetWritable(false)} is never called afterwards (e.g.,
+  // because no {NativeModuleModificationScope} is created), the writable
+  // permission is never withdrawn.
+  // One potential fix is to allocate initially with kReadExecute only, which
+  // forces all compilation threads to add the missing
+  // {NativeModuleModificationScope}s before modification; and/or adding
+  // DCHECKs that {NativeModuleModificationScope} is open when calling this
+  // method.
+  PageAllocator::Permission permission = PageAllocator::kReadWriteExecute;
+
+  bool success;
+  if (FLAG_wasm_memory_protection_keys) {
+    TRACE_HEAP(
+        "Setting rwx permissions and memory protection key %d for 0x%" PRIxPTR
+        ":0x%" PRIxPTR "\n",
+        memory_protection_key_, region.begin(), region.end());
+    success = SetPermissionsAndMemoryProtectionKey(
+        GetPlatformPageAllocator(), region, permission, memory_protection_key_);
+  } else {
+    TRACE_HEAP("Setting rwx permissions for 0x%" PRIxPTR ":0x%" PRIxPTR "\n",
+               region.begin(), region.end());
+    success = SetPermissions(GetPlatformPageAllocator(), region.begin(),
+                             region.size(), permission);
+  }
 
-  if (!SetPermissions(GetPlatformPageAllocator(), region.begin(), region.size(),
-                      permission)) {
-    // Highly unlikely.
+  if (V8_UNLIKELY(!success)) {
     V8::FatalProcessOutOfMemory(
         nullptr,
         "WasmCodeManager::Commit: Cannot make pre-reserved region writable");
@@ -1739,8 +1800,13 @@ void WasmCodeManager::Decommit(base::AddressRegion region) {
   USE(old_committed);
   TRACE_HEAP("Discarding system pages 0x%" PRIxPTR ":0x%" PRIxPTR "\n",
              region.begin(), region.end());
-  CHECK(allocator->SetPermissions(reinterpret_cast<void*>(region.begin()),
-                                  region.size(), PageAllocator::kNoAccess));
+  if (FLAG_wasm_memory_protection_keys) {
+    CHECK(SetPermissionsAndMemoryProtectionKey(
+        allocator, region, PageAllocator::kNoAccess, kNoMemoryProtectionKey));
+  } else {
+    CHECK(SetPermissions(allocator, region.begin(), region.size(),
+                         PageAllocator::kNoAccess));
+  }
 }
 
 void WasmCodeManager::AssignRange(base::AddressRegion region,
@@ -2002,10 +2068,15 @@ std::vector<std::unique_ptr<WasmCode>> NativeModule::AddCompiledCode(
     DCHECK(result.succeeded());
     total_code_space += RoundUp<kCodeAlignment>(result.code_desc.instr_size);
   }
-  Vector<byte> code_space =
-      code_allocator_.AllocateForCode(this, total_code_space);
-  // Lookup the jump tables to use once, then use for all code objects.
-  auto jump_tables = FindJumpTablesForRegion(base::AddressRegionOf(code_space));
+  Vector<byte> code_space;
+  NativeModule::JumpTablesRef jump_tables;
+  {
+    base::RecursiveMutexGuard guard{&allocation_mutex_};
+    code_space = code_allocator_.AllocateForCode(this, total_code_space);
+    // Lookup the jump tables to use once, then use for all code objects.
+    jump_tables =
+        FindJumpTablesForRegionLocked(base::AddressRegionOf(code_space));
+  }
   // If we happen to have a {total_code_space} which is bigger than
   // {kMaxCodeSpaceSize}, we would not find valid jump tables for the whole
   // region. If this ever happens, we need to handle this case (by splitting the
@@ -2017,6 +2088,7 @@ std::vector<std::unique_ptr<WasmCode>> NativeModule::AddCompiledCode(
 
   // Now copy the generated code into the code space and relocate it.
   CODE_SPACE_WRITE_SCOPE
+  NativeModuleModificationScope native_module_modification_scope(this);
   for (auto& result : results) {
     DCHECK_EQ(result.code_desc.buffer, result.instr_buffer.get());
     size_t code_size = RoundUp<kCodeAlignment>(result.code_desc.instr_size);
@@ -2039,12 +2111,12 @@ void NativeModule::SetTieringState(TieringState new_tiering_state) {
   // Do not tier down asm.js (just never change the tiering state).
   if (module()->origin != kWasmOrigin) return;
 
-  base::MutexGuard lock(&allocation_mutex_);
+  base::RecursiveMutexGuard lock(&allocation_mutex_);
   tiering_state_ = new_tiering_state;
 }
 
 bool NativeModule::IsTieredDown() {
-  base::MutexGuard lock(&allocation_mutex_);
+  base::RecursiveMutexGuard lock(&allocation_mutex_);
   return tiering_state_ == kTieredDown;
 }
 
@@ -2054,7 +2126,7 @@ void NativeModule::RecompileForTiering() {
   // compilation units finish, code installation will handle that correctly.
   TieringState current_state;
   {
-    base::MutexGuard lock(&allocation_mutex_);
+    base::RecursiveMutexGuard lock(&allocation_mutex_);
     current_state = tiering_state_;
 
     // Initialize {cached_code_} to signal that this cache should get filled
@@ -2074,7 +2146,7 @@ void NativeModule::RecompileForTiering() {
 std::vector<int> NativeModule::FindFunctionsToRecompile(
     TieringState new_tiering_state) {
   WasmCodeRefScope code_ref_scope;
-  base::MutexGuard guard(&allocation_mutex_);
+  base::RecursiveMutexGuard guard(&allocation_mutex_);
   std::vector<int> function_indexes;
   int imported = module()->num_imported_functions;
   int declared = module()->num_declared_functions;
@@ -2110,19 +2182,16 @@ std::vector<int> NativeModule::FindFunctionsToRecompile(
 }
 
 void NativeModule::FreeCode(Vector<WasmCode* const> codes) {
+  base::RecursiveMutexGuard guard(&allocation_mutex_);
   // Free the code space.
   code_allocator_.FreeCode(codes);
 
-  DebugInfo* debug_info = nullptr;
-  {
-    base::MutexGuard guard(&allocation_mutex_);
-    if (!new_owned_code_.empty()) TransferNewOwnedCodeLocked();
-    debug_info = debug_info_.get();
-    // Free the {WasmCode} objects. This will also unregister trap handler data.
-    for (WasmCode* code : codes) {
-      DCHECK_EQ(1, owned_code_.count(code->instruction_start()));
-      owned_code_.erase(code->instruction_start());
-    }
+  if (!new_owned_code_.empty()) TransferNewOwnedCodeLocked();
+  DebugInfo* debug_info = debug_info_.get();
+  // Free the {WasmCode} objects. This will also unregister trap handler data.
+  for (WasmCode* code : codes) {
+    DCHECK_EQ(1, owned_code_.count(code->instruction_start()));
+    owned_code_.erase(code->instruction_start());
   }
   // Remove debug side tables for all removed code objects, after releasing our
   // lock. This is to avoid lock order inversion.
@@ -2130,16 +2199,17 @@ void NativeModule::FreeCode(Vector<WasmCode* const> codes) {
 }
 
 size_t NativeModule::GetNumberOfCodeSpacesForTesting() const {
+  base::RecursiveMutexGuard guard{&allocation_mutex_};
   return code_allocator_.GetNumCodeSpaces();
 }
 
 bool NativeModule::HasDebugInfo() const {
-  base::MutexGuard guard(&allocation_mutex_);
+  base::RecursiveMutexGuard guard(&allocation_mutex_);
   return debug_info_ != nullptr;
 }
 
 DebugInfo* NativeModule::GetDebugInfo() {
-  base::MutexGuard guard(&allocation_mutex_);
+  base::RecursiveMutexGuard guard(&allocation_mutex_);
   if (!debug_info_) debug_info_ = std::make_unique<DebugInfo>(this);
   return debug_info_.get();
 }
@@ -2200,17 +2270,30 @@ WasmCode* WasmCodeManager::LookupCode(Address pc) const {
 NativeModuleModificationScope::NativeModuleModificationScope(
     NativeModule* native_module)
     : native_module_(native_module) {
-  if (FLAG_wasm_write_protect_code_memory && native_module_ &&
-      (native_module_->modification_scope_depth_++) == 0) {
-    bool success = native_module_->SetExecutable(false);
+  DCHECK_NOT_NULL(native_module_);
+  if (FLAG_wasm_memory_protection_keys) {
+    bool success = native_module_->SetThreadWritable(true);
+    if (!success && FLAG_wasm_write_protect_code_memory) {
+      // Fallback to mprotect-based write protection (much slower).
+      success = native_module_->SetWritable(true);
+      CHECK(success);
+    }
+  } else if (FLAG_wasm_write_protect_code_memory) {
+    bool success = native_module_->SetWritable(true);
     CHECK(success);
   }
 }
 
 NativeModuleModificationScope::~NativeModuleModificationScope() {
-  if (FLAG_wasm_write_protect_code_memory && native_module_ &&
-      (native_module_->modification_scope_depth_--) == 1) {
-    bool success = native_module_->SetExecutable(true);
+  if (FLAG_wasm_memory_protection_keys) {
+    bool success = native_module_->SetThreadWritable(false);
+    if (!success && FLAG_wasm_write_protect_code_memory) {
+      // Fallback to mprotect-based write protection (much slower).
+      success = native_module_->SetWritable(false);
+      CHECK(success);
+    }
+  } else if (FLAG_wasm_write_protect_code_memory) {
+    bool success = native_module_->SetWritable(false);
     CHECK(success);
   }
 }
diff --git a/chromium/v8/src/wasm/wasm-code-manager.h b/chromium/v8/src/wasm/wasm-code-manager.h
index 2996a6e2c67..312f5346b44 100644
--- a/chromium/v8/src/wasm/wasm-code-manager.h
+++ b/chromium/v8/src/wasm/wasm-code-manager.h
@@ -26,6 +26,7 @@
 #include "src/trap-handler/trap-handler.h"
 #include "src/utils/vector.h"
 #include "src/wasm/compilation-environment.h"
+#include "src/wasm/memory-protection-key.h"
 #include "src/wasm/wasm-features.h"
 #include "src/wasm/wasm-limits.h"
 #include "src/wasm/wasm-module-sourcemap.h"
@@ -94,7 +95,8 @@ struct WasmModule;
   V(WasmAllocateArrayWithRtt)            \
   V(WasmAllocateRtt)                     \
   V(WasmAllocateStructWithRtt)           \
-  V(WasmSubtypeCheck)
+  V(WasmSubtypeCheck)                    \
+  V(WasmOnStackReplace)
 
 // Sorted, disjoint and non-overlapping memory regions. A region is of the
 // form [start, end). So there's no [start, end), [end, other_end),
@@ -160,11 +162,7 @@ class V8_EXPORT_PRIVATE WasmCode final {
     return {reloc_info().end(), static_cast<size_t>(source_positions_size_)};
   }
 
-  // TODO(clemensb): Make this return int.
-  uint32_t index() const {
-    DCHECK_LE(0, index_);
-    return index_;
-  }
+  int index() const { return index_; }
   // Anonymous functions are functions that don't carry an index.
   bool IsAnonymous() const { return index_ == kAnonymousFuncIndex; }
   Kind kind() const { return KindField::decode(flags_); }
@@ -397,31 +395,11 @@ class WasmCodeAllocator {
   static constexpr size_t kMaxCodeSpaceSize = 1024 * MB;
 #endif
 
-  // {OptionalLock} is passed between {WasmCodeAllocator} and {NativeModule} to
-  // indicate that the lock on the {WasmCodeAllocator} is already taken. It's
-  // optional to allow to also call methods without holding the lock.
-  class OptionalLock {
-   public:
-    // External users can only instantiate a non-locked {OptionalLock}.
-    OptionalLock() = default;
-    ~OptionalLock();
-    bool is_locked() const { return allocator_ != nullptr; }
-
-   private:
-    friend class WasmCodeAllocator;
-    // {Lock} is called from the {WasmCodeAllocator} if no locked {OptionalLock}
-    // is passed.
-    void Lock(WasmCodeAllocator*);
-
-    WasmCodeAllocator* allocator_ = nullptr;
-  };
-
-  WasmCodeAllocator(WasmCodeManager*, VirtualMemory code_space,
-                    std::shared_ptr<Counters> async_counters);
+  WasmCodeAllocator(WasmCodeManager*, std::shared_ptr<Counters> async_counters);
   ~WasmCodeAllocator();
 
   // Call before use, after the {NativeModule} is set up completely.
-  void Init(NativeModule*);
+  void Init(VirtualMemory code_space);
 
   size_t committed_code_space() const {
     return committed_code_space_.load(std::memory_order_acquire);
@@ -434,22 +412,32 @@ class WasmCodeAllocator {
   }
 
   // Allocate code space. Returns a valid buffer or fails with OOM (crash).
+  // Hold the {NativeModule}'s {allocation_mutex_} when calling this method.
   Vector<byte> AllocateForCode(NativeModule*, size_t size);
 
   // Allocate code space within a specific region. Returns a valid buffer or
   // fails with OOM (crash).
+  // Hold the {NativeModule}'s {allocation_mutex_} when calling this method.
   Vector<byte> AllocateForCodeInRegion(NativeModule*, size_t size,
-                                       base::AddressRegion,
-                                       const WasmCodeAllocator::OptionalLock&);
+                                       base::AddressRegion);
+
+  // Sets permissions of all owned code space to read-write or read-only (if
+  // {writable} is false). Returns true on success.
+  // Hold the {NativeModule}'s {allocation_mutex_} when calling this method.
+  V8_EXPORT_PRIVATE bool SetWritable(bool writable);
 
-  // Sets permissions of all owned code space to executable, or read-write (if
-  // {executable} is false). Returns true on success.
-  V8_EXPORT_PRIVATE bool SetExecutable(bool executable);
+  // Set this thread's permission of all owned code space to read-write or
+  // read-only (if {writable} is false). Uses memory protection keys.
+  // Returns true on success. Since the permission is thread-local, there is no
+  // requirement to hold any lock when calling this method.
+  bool SetThreadWritable(bool writable);
 
   // Free memory pages of all given code objects. Used for wasm code GC.
+  // Hold the {NativeModule}'s {allocation_mutex_} when calling this method.
   void FreeCode(Vector<WasmCode* const>);
 
   // Retrieve the number of separately reserved code spaces.
+  // Hold the {NativeModule}'s {allocation_mutex_} when calling this method.
   size_t GetNumCodeSpaces() const;
 
  private:
@@ -461,10 +449,8 @@ class WasmCodeAllocator {
   // The engine-wide wasm code manager.
   WasmCodeManager* const code_manager_;
 
-  mutable base::Mutex mutex_;
-
   //////////////////////////////////////////////////////////////////////////////
-  // Protected by {mutex_}:
+  // These fields are protected by the mutex in {NativeModule}.
 
   // Code space that was reserved and is available for allocations (subset of
   // {owned_code_space_}).
@@ -476,6 +462,8 @@ class WasmCodeAllocator {
   DisjointAllocationPool freed_code_space_;
   std::vector<VirtualMemory> owned_code_space_;
 
+  int writers_count_{0};
+
   // End of fields protected by {mutex_}.
   //////////////////////////////////////////////////////////////////////////////
 
@@ -483,8 +471,6 @@ class WasmCodeAllocator {
   std::atomic<size_t> generated_code_size_{0};
   std::atomic<size_t> freed_code_size_{0};
 
-  bool is_executable_ = false;
-
   std::shared_ptr<Counters> async_counters_;
 };
 
@@ -523,7 +509,15 @@ class V8_EXPORT_PRIVATE NativeModule final {
   // table and jump table via another {PublishCode}.
   void ReinstallDebugCode(WasmCode*);
 
-  Vector<uint8_t> AllocateForDeserializedCode(size_t total_code_size);
+  struct JumpTablesRef {
+    Address jump_table_start = kNullAddress;
+    Address far_jump_table_start = kNullAddress;
+
+    bool is_valid() const { return far_jump_table_start != kNullAddress; }
+  };
+
+  std::pair<Vector<uint8_t>, JumpTablesRef> AllocateForDeserializedCode(
+      size_t total_code_size);
 
   std::unique_ptr<WasmCode> AddDeserializedCode(
       int index, Vector<byte> instructions, int stack_slots,
@@ -564,26 +558,19 @@ class V8_EXPORT_PRIVATE NativeModule final {
   // the first jump table).
   Address GetCallTargetForFunction(uint32_t func_index) const;
 
-  struct JumpTablesRef {
-    Address jump_table_start = kNullAddress;
-    Address far_jump_table_start = kNullAddress;
-
-    bool is_valid() const { return far_jump_table_start != kNullAddress; }
-  };
-
   // Finds the jump tables that should be used for given code region. This
   // information is then passed to {GetNearCallTargetForFunction} and
   // {GetNearRuntimeStubEntry} to avoid the overhead of looking this information
   // up there. Return an empty struct if no suitable jump tables exist.
-  JumpTablesRef FindJumpTablesForRegion(base::AddressRegion) const;
+  JumpTablesRef FindJumpTablesForRegionLocked(base::AddressRegion) const;
 
   // Similarly to {GetCallTargetForFunction}, but uses the jump table previously
-  // looked up via {FindJumpTablesForRegion}.
+  // looked up via {FindJumpTablesForRegionLocked}.
   Address GetNearCallTargetForFunction(uint32_t func_index,
                                        const JumpTablesRef&) const;
 
   // Get a runtime stub entry (which is a far jump table slot) in the jump table
-  // previously looked up via {FindJumpTablesForRegion}.
+  // previously looked up via {FindJumpTablesForRegionLocked}.
   Address GetNearRuntimeStubEntry(WasmCode::RuntimeStubId index,
                                   const JumpTablesRef&) const;
 
@@ -591,8 +578,13 @@ class V8_EXPORT_PRIVATE NativeModule final {
   // to a function index.
   uint32_t GetFunctionIndexFromJumpTableSlot(Address slot_address) const;
 
-  bool SetExecutable(bool executable) {
-    return code_allocator_.SetExecutable(executable);
+  bool SetWritable(bool writable) {
+    base::RecursiveMutexGuard guard{&allocation_mutex_};
+    return code_allocator_.SetWritable(writable);
+  }
+
+  bool SetThreadWritable(bool writable) {
+    return code_allocator_.SetThreadWritable(writable);
   }
 
   // For cctests, where we build both WasmModule and the runtime objects
@@ -726,9 +718,8 @@ class V8_EXPORT_PRIVATE NativeModule final {
       ExecutionTier tier, ForDebugging for_debugging,
       Vector<uint8_t> code_space, const JumpTablesRef& jump_tables_ref);
 
-  WasmCode* CreateEmptyJumpTableInRegion(
-      int jump_table_size, base::AddressRegion,
-      const WasmCodeAllocator::OptionalLock&);
+  WasmCode* CreateEmptyJumpTableInRegionLocked(int jump_table_size,
+                                               base::AddressRegion);
 
   void UpdateCodeSize(size_t, ExecutionTier, ForDebugging);
 
@@ -740,8 +731,7 @@ class V8_EXPORT_PRIVATE NativeModule final {
                             Address target);
 
   // Called by the {WasmCodeAllocator} to register a new code space.
-  void AddCodeSpace(base::AddressRegion,
-                    const WasmCodeAllocator::OptionalLock&);
+  void AddCodeSpaceLocked(base::AddressRegion);
 
   // Hold the {allocation_mutex_} when calling {PublishCodeLocked}.
   WasmCode* PublishCodeLocked(std::unique_ptr<WasmCode>);
@@ -806,7 +796,12 @@ class V8_EXPORT_PRIVATE NativeModule final {
   std::unique_ptr<uint32_t[]> num_liftoff_function_calls_;
 
   // This mutex protects concurrent calls to {AddCode} and friends.
-  mutable base::Mutex allocation_mutex_;
+  // TODO(dlehmann): Revert this to a regular {Mutex} again.
+  // This needs to be a {RecursiveMutex} only because of
+  // {NativeModuleModificationScope} usages, which are (1) either at places
+  // that already hold the {allocation_mutex_} or (2) because of multiple open
+  // {NativeModuleModificationScope}s in the call hierarchy. Both are fixable.
+  mutable base::RecursiveMutex allocation_mutex_;
 
   //////////////////////////////////////////////////////////////////////////////
   // Protected by {allocation_mutex_}:
@@ -847,7 +842,6 @@ class V8_EXPORT_PRIVATE NativeModule final {
   // End of fields protected by {allocation_mutex_}.
   //////////////////////////////////////////////////////////////////////////////
 
-  int modification_scope_depth_ = 0;
   UseTrapHandler use_trap_handler_ = kNoTrapHandler;
   bool lazy_compile_frozen_ = false;
   std::atomic<size_t> liftoff_bailout_count_{0};
@@ -861,12 +855,7 @@ class V8_EXPORT_PRIVATE WasmCodeManager final {
   WasmCodeManager(const WasmCodeManager&) = delete;
   WasmCodeManager& operator=(const WasmCodeManager&) = delete;
 
-#ifdef DEBUG
-  ~WasmCodeManager() {
-    // No more committed code space.
-    DCHECK_EQ(0, total_committed_code_space_.load());
-  }
-#endif
+  ~WasmCodeManager();
 
 #if defined(V8_OS_WIN64)
   bool CanRegisterUnwindInfoForNonABICompliantCodeRange() const;
@@ -922,6 +911,8 @@ class V8_EXPORT_PRIVATE WasmCodeManager final {
   // and updated after each GC.
   std::atomic<size_t> critical_committed_code_space_;
 
+  const int memory_protection_key_;
+
   mutable base::Mutex native_modules_mutex_;
 
   //////////////////////////////////////////////////////////////////////////////
diff --git a/chromium/v8/src/wasm/wasm-constants.h b/chromium/v8/src/wasm/wasm-constants.h
index a02ea78e850..f960e7c201a 100644
--- a/chromium/v8/src/wasm/wasm-constants.h
+++ b/chromium/v8/src/wasm/wasm-constants.h
@@ -101,10 +101,11 @@ enum SectionCode : int8_t {
   kDebugInfoSectionCode,          // DWARF section .debug_info
   kExternalDebugInfoSectionCode,  // Section encoding the external symbol path
   kCompilationHintsSectionCode,   // Compilation hints section
+  kBranchHintsSectionCode,        // Branch hints section
 
   // Helper values
   kFirstSectionInModule = kTypeSectionCode,
-  kLastKnownModuleSection = kCompilationHintsSectionCode,
+  kLastKnownModuleSection = kBranchHintsSectionCode,
   kFirstUnorderedSection = kDataCountSectionCode,
 };
 
@@ -156,6 +157,10 @@ constexpr int kAnonymousFuncIndex = -1;
 // often enough.
 constexpr uint32_t kGenericWrapperBudget = 1000;
 
+#if V8_TARGET_ARCH_X64
+constexpr int32_t kOSRTargetOffset = 3 * kSystemPointerSize;
+#endif
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/wasm/wasm-debug.cc b/chromium/v8/src/wasm/wasm-debug.cc
index 22872f5d884..ad4e7853aa1 100644
--- a/chromium/v8/src/wasm/wasm-debug.cc
+++ b/chromium/v8/src/wasm/wasm-debug.cc
@@ -697,13 +697,19 @@ class DebugInfoImpl {
     DCHECK_EQ(frame->function_index(), new_code->index());
     DCHECK_EQ(frame->native_module(), new_code->native_module());
     DCHECK(frame->wasm_code()->is_liftoff());
+    Address new_pc =
+        FindNewPC(frame, new_code, frame->byte_offset(), return_location);
 #ifdef DEBUG
     int old_position = frame->position();
 #endif
-    Address new_pc =
-        FindNewPC(frame, new_code, frame->byte_offset(), return_location);
+#if V8_TARGET_ARCH_X64
+    if (frame->wasm_code()->for_debugging()) {
+      base::Memory<Address>(frame->fp() - kOSRTargetOffset) = new_pc;
+    }
+#else
     PointerAuthentication::ReplacePC(frame->pc_address(), new_pc,
                                      kSystemPointerSize);
+#endif
     // The frame position should still be the same after OSR.
     DCHECK_EQ(old_position, frame->position());
   }
diff --git a/chromium/v8/src/wasm/wasm-engine.cc b/chromium/v8/src/wasm/wasm-engine.cc
index ed19f89a5e8..c38236dc789 100644
--- a/chromium/v8/src/wasm/wasm-engine.cc
+++ b/chromium/v8/src/wasm/wasm-engine.cc
@@ -18,6 +18,7 @@
 #include "src/strings/string-hasher-inl.h"
 #include "src/utils/ostreams.h"
 #include "src/wasm/function-compiler.h"
+#include "src/wasm/memory-protection-key.h"
 #include "src/wasm/module-compiler.h"
 #include "src/wasm/module-decoder.h"
 #include "src/wasm/module-instantiate.h"
@@ -347,7 +348,8 @@ struct WasmEngine::CurrentGCInfo {
 struct WasmEngine::IsolateInfo {
   explicit IsolateInfo(Isolate* isolate)
       : log_codes(WasmCode::ShouldBeLogged(isolate)),
-        async_counters(isolate->async_counters()) {
+        async_counters(isolate->async_counters()),
+        wrapper_compilation_barrier_(std::make_shared<OperationsBarrier>()) {
     v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(isolate);
     v8::Platform* platform = V8::GetCurrentPlatform();
     foreground_task_runner = platform->GetForegroundTaskRunner(v8_isolate);
@@ -398,6 +400,12 @@ struct WasmEngine::IsolateInfo {
   int throw_count = 0;
   int rethrow_count = 0;
   int catch_count = 0;
+
+  // Operations barrier to synchronize on wrapper compilation on isolate
+  // shutdown.
+  // TODO(wasm): Remove this once we can use the generic js-to-wasm wrapper
+  // everywhere.
+  std::shared_ptr<OperationsBarrier> wrapper_compilation_barrier_;
 };
 
 struct WasmEngine::NativeModuleInfo {
@@ -934,9 +942,10 @@ void WasmEngine::DeleteCompileJobsOnIsolate(Isolate* isolate) {
   // Under the mutex get all jobs to delete. Then delete them without holding
   // the mutex, such that deletion can reenter the WasmEngine.
   std::vector<std::unique_ptr<AsyncCompileJob>> jobs_to_delete;
+  std::vector<std::weak_ptr<NativeModule>> modules_in_isolate;
+  std::shared_ptr<OperationsBarrier> wrapper_compilation_barrier;
   {
     base::MutexGuard guard(&mutex_);
-    DCHECK_EQ(1, isolates_.count(isolate));
     for (auto it = async_compile_jobs_.begin();
          it != async_compile_jobs_.end();) {
       if (it->first->isolate() != isolate) {
@@ -946,7 +955,34 @@ void WasmEngine::DeleteCompileJobsOnIsolate(Isolate* isolate) {
       jobs_to_delete.push_back(std::move(it->second));
       it = async_compile_jobs_.erase(it);
     }
+    DCHECK_EQ(1, isolates_.count(isolate));
+    auto* isolate_info = isolates_[isolate].get();
+    wrapper_compilation_barrier = isolate_info->wrapper_compilation_barrier_;
+    for (auto* native_module : isolate_info->native_modules) {
+      DCHECK_EQ(1, native_modules_.count(native_module));
+      modules_in_isolate.emplace_back(native_modules_[native_module]->weak_ptr);
+    }
   }
+
+  // All modules that have not finished initial compilation yet cannot be
+  // shared with other isolates. Hence we cancel their compilation. In
+  // particular, this will cancel wrapper compilation which is bound to this
+  // isolate (this would be a UAF otherwise).
+  for (auto& weak_module : modules_in_isolate) {
+    if (auto shared_module = weak_module.lock()) {
+      shared_module->compilation_state()->CancelInitialCompilation();
+    }
+  }
+
+  // After cancelling, wait for all current wrapper compilation to actually
+  // finish.
+  wrapper_compilation_barrier->CancelAndWait();
+}
+
+OperationsBarrier::Token WasmEngine::StartWrapperCompilation(Isolate* isolate) {
+  base::MutexGuard guard(&mutex_);
+  DCHECK_EQ(1, isolates_.count(isolate));
+  return isolates_[isolate]->wrapper_compilation_barrier_->TryLock();
 }
 
 void WasmEngine::AddIsolate(Isolate* isolate) {
@@ -954,6 +990,15 @@ void WasmEngine::AddIsolate(Isolate* isolate) {
   DCHECK_EQ(0, isolates_.count(isolate));
   isolates_.emplace(isolate, std::make_unique<IsolateInfo>(isolate));
 
+  // Record memory protection key support.
+  if (FLAG_wasm_memory_protection_keys) {
+    auto* histogram =
+        isolate->counters()->wasm_memory_protection_keys_support();
+    bool has_mpk =
+        code_manager()->memory_protection_key_ != kNoMemoryProtectionKey;
+    histogram->AddSample(has_mpk ? 1 : 0);
+  }
+
   // Install sampling GC callback.
   // TODO(v8:7424): For now we sample module sizes in a GC callback. This will
   // bias samples towards apps with high memory pressure. We should switch to
@@ -1281,6 +1326,18 @@ void WasmEngine::ReportLiveCodeFromStackForGC(Isolate* isolate) {
     StackFrame* const frame = it.frame();
     if (frame->type() != StackFrame::WASM) continue;
     live_wasm_code.insert(WasmFrame::cast(frame)->wasm_code());
+#if V8_TARGET_ARCH_X64
+    if (WasmFrame::cast(frame)->wasm_code()->for_debugging()) {
+      Address osr_target = base::Memory<Address>(WasmFrame::cast(frame)->fp() -
+                                                 kOSRTargetOffset);
+      if (osr_target) {
+        WasmCode* osr_code =
+            isolate->wasm_engine()->code_manager()->LookupCode(osr_target);
+        DCHECK_NOT_NULL(osr_code);
+        live_wasm_code.insert(osr_code);
+      }
+    }
+#endif
   }
 
   CheckNoArchivedThreads(isolate);
@@ -1514,24 +1571,29 @@ void WasmEngine::PotentiallyFinishCurrentGC() {
 
 namespace {
 
-DEFINE_LAZY_LEAKY_OBJECT_GETTER(std::shared_ptr<WasmEngine>,
-                                GetSharedWasmEngine)
+WasmEngine* global_wasm_engine = nullptr;
 
 }  // namespace
 
 // static
 void WasmEngine::InitializeOncePerProcess() {
-  *GetSharedWasmEngine() = std::make_shared<WasmEngine>();
+  DCHECK_NULL(global_wasm_engine);
+  global_wasm_engine = new WasmEngine();
 }
 
 // static
 void WasmEngine::GlobalTearDown() {
-  GetSharedWasmEngine()->reset();
+  // Note: This can be called multiple times in a row (see
+  // test-api/InitializeAndDisposeMultiple). This is fine, as
+  // {global_wasm_engine} will be nullptr then.
+  delete global_wasm_engine;
+  global_wasm_engine = nullptr;
 }
 
 // static
-std::shared_ptr<WasmEngine> WasmEngine::GetWasmEngine() {
-  return *GetSharedWasmEngine();
+WasmEngine* WasmEngine::GetWasmEngine() {
+  DCHECK_NOT_NULL(global_wasm_engine);
+  return global_wasm_engine;
 }
 
 // {max_mem_pages} is declared in wasm-limits.h.
diff --git a/chromium/v8/src/wasm/wasm-engine.h b/chromium/v8/src/wasm/wasm-engine.h
index 5a26bd44577..d4736036cba 100644
--- a/chromium/v8/src/wasm/wasm-engine.h
+++ b/chromium/v8/src/wasm/wasm-engine.h
@@ -246,6 +246,12 @@ class V8_EXPORT_PRIVATE WasmEngine {
   // for tearing down an isolate, or to clean it up to be reused.
   void DeleteCompileJobsOnIsolate(Isolate* isolate);
 
+  // Get a token for compiling wrappers for an Isolate. The token is used to
+  // synchronize background tasks on isolate shutdown. The caller should only
+  // hold the token while compiling export wrappers. If the isolate is already
+  // shutting down, this method will return an invalid token.
+  OperationsBarrier::Token StartWrapperCompilation(Isolate*);
+
   // Manage the set of Isolates that use this WasmEngine.
   void AddIsolate(Isolate* isolate);
   void RemoveIsolate(Isolate* isolate);
@@ -351,10 +357,8 @@ class V8_EXPORT_PRIVATE WasmEngine {
   static void InitializeOncePerProcess();
   static void GlobalTearDown();
 
-  // Returns a reference to the WasmEngine shared by the entire process. Try to
-  // use {Isolate::wasm_engine} instead if it is available, which encapsulates
-  // engine lifetime decisions during Isolate bootstrapping.
-  static std::shared_ptr<WasmEngine> GetWasmEngine();
+  // Returns a reference to the WasmEngine shared by the entire process.
+  static WasmEngine* GetWasmEngine();
 
  private:
   struct CurrentGCInfo;
diff --git a/chromium/v8/src/wasm/wasm-feature-flags.h b/chromium/v8/src/wasm/wasm-feature-flags.h
index 9c790d7c67e..9adf3d662f1 100644
--- a/chromium/v8/src/wasm/wasm-feature-flags.h
+++ b/chromium/v8/src/wasm/wasm-feature-flags.h
@@ -37,7 +37,12 @@
   /* Relaxed SIMD proposal. */                                                 \
   /* https://github.com/WebAssembly/relaxed-simd */                            \
   /* V8 side owner: zhin */                                                    \
-  V(relaxed_simd, "relaxed simd", false)
+  V(relaxed_simd, "relaxed simd", false)                                       \
+                                                                               \
+  /* Branch Hinting proposal. */                                               \
+  /* https://github.com/WebAssembly/branch-hinting */                          \
+  /* V8 side owner: jkummerow */                                               \
+  V(branch_hinting, "branch hinting", false)
 
 // #############################################################################
 // Staged features (disabled by default, but enabled via --wasm-staging (also
@@ -76,13 +81,6 @@
 // Shipped features (enabled by default). Remove the feature flag once they hit
 // stable and are expected to stay enabled.
 #define FOREACH_WASM_SHIPPED_FEATURE_FLAG(V) /*          (force 80 columns) */ \
-  /* Multi-value proposal. */                                                  \
-  /* https://github.com/WebAssembly/multi-value */                             \
-  /* V8 side owner: thibaudm */                                                \
-  /* Shipped in v8.6. */                                                       \
-  /* ITS: https://groups.google.com/g/v8-users/c/pv2E4yFWeF0 */                \
-  V(mv, "multi-value support", true)                                           \
-                                                                               \
   /* Fixed-width SIMD operations. */                                           \
   /* https://github.com/webassembly/simd */                                    \
   /* V8 side owner: gdeepti, zhin */                                           \
diff --git a/chromium/v8/src/wasm/wasm-init-expr.cc b/chromium/v8/src/wasm/wasm-init-expr.cc
new file mode 100644
index 00000000000..6348c581936
--- /dev/null
+++ b/chromium/v8/src/wasm/wasm-init-expr.cc
@@ -0,0 +1,57 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/wasm/wasm-init-expr.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+
+std::ostream& operator<<(std::ostream& os, const WasmInitExpr& expr) {
+  os << "(";
+  switch (expr.kind()) {
+    case WasmInitExpr::kNone:
+      UNREACHABLE();
+    case WasmInitExpr::kGlobalGet:
+      os << "global.get " << expr.immediate().index;
+      break;
+    case WasmInitExpr::kI32Const:
+      os << "i32.const " << expr.immediate().i32_const;
+      break;
+    case WasmInitExpr::kI64Const:
+      os << "i64.const " << expr.immediate().i64_const;
+      break;
+    case WasmInitExpr::kF32Const:
+      os << "f32.const " << expr.immediate().f32_const;
+      break;
+    case WasmInitExpr::kF64Const:
+      os << "f64.const " << expr.immediate().f64_const;
+      break;
+    case WasmInitExpr::kS128Const:
+      os << "s128.const 0x" << std::hex;
+      for (uint8_t b : expr.immediate().s128_const) {
+        os << b;
+      }
+      os << std::dec;
+      break;
+    case WasmInitExpr::kRefNullConst:
+      os << "ref.null " << expr.immediate().heap_type;
+      break;
+    case WasmInitExpr::kRefFuncConst:
+      os << "ref.func " << expr.immediate().index;
+      break;
+    case WasmInitExpr::kRttCanon:
+      os << "rtt.canon " << expr.immediate().heap_type;
+      break;
+    case WasmInitExpr::kRttSub:
+      os << "rtt.sub " << *expr.operand();
+      break;
+  }
+  os << ")";
+  return os;
+}
+
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
diff --git a/chromium/v8/src/wasm/wasm-init-expr.h b/chromium/v8/src/wasm/wasm-init-expr.h
new file mode 100644
index 00000000000..39fc1a7ee6a
--- /dev/null
+++ b/chromium/v8/src/wasm/wasm-init-expr.h
@@ -0,0 +1,150 @@
+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#if !V8_ENABLE_WEBASSEMBLY
+#error This header should only be included if WebAssembly is enabled.
+#endif  // !V8_ENABLE_WEBASSEMBLY
+
+#ifndef V8_WASM_WASM_INIT_EXPR_H_
+#define V8_WASM_WASM_INIT_EXPR_H_
+
+#include <memory>
+
+#include "src/wasm/value-type.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+
+// Representation of an initializer expression.
+class WasmInitExpr {
+ public:
+  enum Operator {
+    kNone,
+    kGlobalGet,
+    kI32Const,
+    kI64Const,
+    kF32Const,
+    kF64Const,
+    kS128Const,
+    kRefNullConst,
+    kRefFuncConst,
+    kRttCanon,
+    kRttSub
+  };
+
+  union Immediate {
+    int32_t i32_const;
+    int64_t i64_const;
+    float f32_const;
+    double f64_const;
+    std::array<uint8_t, kSimd128Size> s128_const;
+    uint32_t index;
+    HeapType::Representation heap_type;
+  };
+
+  WasmInitExpr() : kind_(kNone) { immediate_.i32_const = 0; }
+  explicit WasmInitExpr(int32_t v) : kind_(kI32Const) {
+    immediate_.i32_const = v;
+  }
+  explicit WasmInitExpr(int64_t v) : kind_(kI64Const) {
+    immediate_.i64_const = v;
+  }
+  explicit WasmInitExpr(float v) : kind_(kF32Const) {
+    immediate_.f32_const = v;
+  }
+  explicit WasmInitExpr(double v) : kind_(kF64Const) {
+    immediate_.f64_const = v;
+  }
+  explicit WasmInitExpr(uint8_t v[kSimd128Size]) : kind_(kS128Const) {
+    base::Memcpy(immediate_.s128_const.data(), v, kSimd128Size);
+  }
+
+  MOVE_ONLY_NO_DEFAULT_CONSTRUCTOR(WasmInitExpr);
+
+  static WasmInitExpr GlobalGet(uint32_t index) {
+    WasmInitExpr expr;
+    expr.kind_ = kGlobalGet;
+    expr.immediate_.index = index;
+    return expr;
+  }
+
+  static WasmInitExpr RefFuncConst(uint32_t index) {
+    WasmInitExpr expr;
+    expr.kind_ = kRefFuncConst;
+    expr.immediate_.index = index;
+    return expr;
+  }
+
+  static WasmInitExpr RefNullConst(HeapType::Representation heap_type) {
+    WasmInitExpr expr;
+    expr.kind_ = kRefNullConst;
+    expr.immediate_.heap_type = heap_type;
+    return expr;
+  }
+
+  static WasmInitExpr RttCanon(uint32_t index) {
+    WasmInitExpr expr;
+    expr.kind_ = kRttCanon;
+    expr.immediate_.index = index;
+    return expr;
+  }
+
+  static WasmInitExpr RttSub(uint32_t index, WasmInitExpr supertype) {
+    WasmInitExpr expr;
+    expr.kind_ = kRttSub;
+    expr.immediate_.index = index;
+    expr.operand_ = std::make_unique<WasmInitExpr>(std::move(supertype));
+    return expr;
+  }
+
+  Immediate immediate() const { return immediate_; }
+  Operator kind() const { return kind_; }
+  WasmInitExpr* operand() const { return operand_.get(); }
+
+  bool operator==(const WasmInitExpr& other) const {
+    if (kind() != other.kind()) return false;
+    switch (kind()) {
+      case kNone:
+        return true;
+      case kGlobalGet:
+      case kRefFuncConst:
+      case kRttCanon:
+        return immediate().index == other.immediate().index;
+      case kI32Const:
+        return immediate().i32_const == other.immediate().i32_const;
+      case kI64Const:
+        return immediate().i64_const == other.immediate().i64_const;
+      case kF32Const:
+        return immediate().f32_const == other.immediate().f32_const;
+      case kF64Const:
+        return immediate().f64_const == other.immediate().f64_const;
+      case kS128Const:
+        return immediate().s128_const == other.immediate().s128_const;
+      case kRefNullConst:
+        return immediate().heap_type == other.immediate().heap_type;
+      case kRttSub:
+        return immediate().index == other.immediate().index &&
+               *operand() == *other.operand();
+    }
+  }
+
+  V8_INLINE bool operator!=(const WasmInitExpr& other) {
+    return !(*this == other);
+  }
+
+ private:
+  Immediate immediate_;
+  Operator kind_;
+  std::unique_ptr<WasmInitExpr> operand_ = nullptr;
+};
+
+V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os,
+                                           const WasmInitExpr& expr);
+
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_WASM_WASM_INIT_EXPR_H_
diff --git a/chromium/v8/src/wasm/wasm-js.cc b/chromium/v8/src/wasm/wasm-js.cc
index 7f1d8e261ff..70492135dec 100644
--- a/chromium/v8/src/wasm/wasm-js.cc
+++ b/chromium/v8/src/wasm/wasm-js.cc
@@ -1475,9 +1475,7 @@ void WebAssemblyFunction(const v8::FunctionCallbackInfo<v8::Value>& args) {
     thrower.TypeError("Argument 0 contains results without 'length'");
     return;
   }
-  if (results_len > (enabled_features.has_mv()
-                         ? i::wasm::kV8MaxWasmFunctionMultiReturns
-                         : i::wasm::kV8MaxWasmFunctionReturns)) {
+  if (results_len > i::wasm::kV8MaxWasmFunctionReturns) {
     thrower.TypeError("Argument 0 contains too many results");
     return;
   }
@@ -2034,7 +2032,8 @@ Handle<JSFunction> InstallConstructorFunc(Isolate* isolate,
                                           Handle<JSObject> object,
                                           const char* str,
                                           FunctionCallback func) {
-  return InstallFunc(isolate, object, str, func, 1, true, DONT_ENUM);
+  return InstallFunc(isolate, object, str, func, 1, true, DONT_ENUM,
+                     SideEffectType::kHasNoSideEffect);
 }
 
 Handle<String> GetterName(Isolate* isolate, Handle<String> name) {
@@ -2064,7 +2063,8 @@ void InstallGetterSetter(Isolate* isolate, Handle<JSObject> object,
                          FunctionCallback setter) {
   Handle<String> name = v8_str(isolate, str);
   Handle<JSFunction> getter_func =
-      CreateFunc(isolate, GetterName(isolate, name), getter, false);
+      CreateFunc(isolate, GetterName(isolate, name), getter, false,
+                 SideEffectType::kHasNoSideEffect);
   Handle<JSFunction> setter_func =
       CreateFunc(isolate, SetterName(isolate, name), setter, false);
   setter_func->shared().set_length(1);
@@ -2148,11 +2148,12 @@ void WasmJs::Install(Isolate* isolate, bool exposed_on_global_object) {
   JSFunction::SetInitialMap(isolate, module_constructor, module_map,
                             module_proto);
   InstallFunc(isolate, module_constructor, "imports", WebAssemblyModuleImports,
-              1);
+              1, false, NONE, SideEffectType::kHasNoSideEffect);
   InstallFunc(isolate, module_constructor, "exports", WebAssemblyModuleExports,
-              1);
+              1, false, NONE, SideEffectType::kHasNoSideEffect);
   InstallFunc(isolate, module_constructor, "customSections",
-              WebAssemblyModuleCustomSections, 2);
+              WebAssemblyModuleCustomSections, 2, false, NONE,
+              SideEffectType::kHasNoSideEffect);
   JSObject::AddProperty(isolate, module_proto, factory->to_string_tag_symbol(),
                         v8_str(isolate, "WebAssembly.Module"), ro_attributes);
 
@@ -2192,7 +2193,8 @@ void WasmJs::Install(Isolate* isolate, bool exposed_on_global_object) {
   JSFunction::SetInitialMap(isolate, table_constructor, table_map, table_proto);
   InstallGetter(isolate, table_proto, "length", WebAssemblyTableGetLength);
   InstallFunc(isolate, table_proto, "grow", WebAssemblyTableGrow, 1);
-  InstallFunc(isolate, table_proto, "get", WebAssemblyTableGet, 1);
+  InstallFunc(isolate, table_proto, "get", WebAssemblyTableGet, 1, false, NONE,
+              SideEffectType::kHasNoSideEffect);
   InstallFunc(isolate, table_proto, "set", WebAssemblyTableSet, 2);
   if (enabled_features.has_type_reflection()) {
     InstallFunc(isolate, table_constructor, "type", WebAssemblyTableType, 1);
@@ -2232,7 +2234,8 @@ void WasmJs::Install(Isolate* isolate, bool exposed_on_global_object) {
       i::WASM_GLOBAL_OBJECT_TYPE, WasmGlobalObject::kHeaderSize);
   JSFunction::SetInitialMap(isolate, global_constructor, global_map,
                             global_proto);
-  InstallFunc(isolate, global_proto, "valueOf", WebAssemblyGlobalValueOf, 0);
+  InstallFunc(isolate, global_proto, "valueOf", WebAssemblyGlobalValueOf, 0,
+              false, NONE, SideEffectType::kHasNoSideEffect);
   InstallGetterSetter(isolate, global_proto, "value", WebAssemblyGlobalGetValue,
                       WebAssemblyGlobalSetValue);
   if (enabled_features.has_type_reflection()) {
@@ -2243,15 +2246,8 @@ void WasmJs::Install(Isolate* isolate, bool exposed_on_global_object) {
 
   // Setup Exception
   if (enabled_features.has_eh()) {
-    Handle<String> exception_name = v8_str(isolate, "Exception");
-    Handle<JSFunction> exception_constructor =
-        CreateFunc(isolate, exception_name, WebAssemblyException, true,
-                   SideEffectType::kHasSideEffect);
-    exception_constructor->shared().set_length(1);
-    JSObject::AddProperty(isolate, webassembly, exception_name,
-                          exception_constructor, DONT_ENUM);
-    // Install the constructor on the context unconditionally so that it is also
-    // available when the feature is enabled via the origin trial.
+    Handle<JSFunction> exception_constructor = InstallConstructorFunc(
+        isolate, webassembly, "Exception", WebAssemblyException);
     context->set_wasm_exception_constructor(*exception_constructor);
     SetDummyInstanceTemplate(isolate, exception_constructor);
     JSFunction::EnsureHasInitialMap(exception_constructor);
@@ -2332,7 +2328,6 @@ void WasmJs::InstallConditionalFeatures(Isolate* isolate,
     Handle<JSObject> webassembly = Handle<JSObject>::cast(webassembly_obj);
     // Setup Exception
     Handle<String> exception_name = v8_str(isolate, "Exception");
-
     if (JSObject::HasOwnProperty(webassembly, exception_name).FromMaybe(true)) {
       // The {Exception} constructor already exists, there is nothing more to
       // do.
diff --git a/chromium/v8/src/wasm/wasm-limits.h b/chromium/v8/src/wasm/wasm-limits.h
index 78a8f0afd43..9e565db0e8b 100644
--- a/chromium/v8/src/wasm/wasm-limits.h
+++ b/chromium/v8/src/wasm/wasm-limits.h
@@ -43,8 +43,7 @@ constexpr size_t kV8MaxWasmModuleSize = 1024 * 1024 * 1024;  // = 1 GiB
 constexpr size_t kV8MaxWasmFunctionSize = 7654321;
 constexpr size_t kV8MaxWasmFunctionLocals = 50000;
 constexpr size_t kV8MaxWasmFunctionParams = 1000;
-constexpr size_t kV8MaxWasmFunctionMultiReturns = 1000;
-constexpr size_t kV8MaxWasmFunctionReturns = 1;
+constexpr size_t kV8MaxWasmFunctionReturns = 1000;
 constexpr size_t kV8MaxWasmFunctionBrTableSize = 65520;
 // Don't use this limit directly, but use the value of FLAG_wasm_max_table_size.
 constexpr size_t kV8MaxWasmTableSize = 10000000;
@@ -57,7 +56,7 @@ constexpr size_t kV8MaxWasmStructFields = 999;
 constexpr uint32_t kV8MaxRttSubtypingDepth = 31;
 // Maximum supported by implementation: ((1<<27)-3).
 // Reason: total object size in bytes must fit into a Smi, for filler objects.
-constexpr size_t kV8MaxWasmArrayLength = 1u << 24;
+constexpr size_t kV8MaxWasmArrayLength = 1u << 26;
 
 static_assert(kV8MaxWasmTableSize <= 4294967295,  // 2^32 - 1
               "v8 should not exceed WebAssembly's non-web embedding limits");
diff --git a/chromium/v8/src/wasm/wasm-module-builder.cc b/chromium/v8/src/wasm/wasm-module-builder.cc
index 67f826f2fd9..41fa4f6b6bd 100644
--- a/chromium/v8/src/wasm/wasm-module-builder.cc
+++ b/chromium/v8/src/wasm/wasm-module-builder.cc
@@ -13,7 +13,6 @@
 #include "src/wasm/leb-helper.h"
 #include "src/wasm/wasm-constants.h"
 #include "src/wasm/wasm-module.h"
-#include "src/wasm/wasm-opcodes.h"
 #include "src/zone/zone-containers.h"
 
 namespace v8 {
@@ -301,6 +300,11 @@ uint32_t WasmModuleBuilder::AddArrayType(ArrayType* type) {
   return index;
 }
 
+// static
+const uint32_t WasmModuleBuilder::kNullIndex =
+    std::numeric_limits<uint32_t>::max();
+
+// TODO(9495): Add support for typed function tables and more init. expressions.
 uint32_t WasmModuleBuilder::AllocateIndirectFunctions(uint32_t count) {
   DCHECK(allocating_indirect_functions_allowed_);
   uint32_t index = static_cast<uint32_t>(indirect_functions_.size());
@@ -310,7 +314,7 @@ uint32_t WasmModuleBuilder::AllocateIndirectFunctions(uint32_t count) {
   }
   uint32_t new_size = static_cast<uint32_t>(indirect_functions_.size()) + count;
   DCHECK(max_table_size_ == 0 || new_size <= max_table_size_);
-  indirect_functions_.resize(new_size, WasmElemSegment::kNullIndex);
+  indirect_functions_.resize(new_size, kNullIndex);
   uint32_t max = max_table_size_ > 0 ? max_table_size_ : new_size;
   if (tables_.empty()) {
     // This cannot use {AddTable} because that would flip the
@@ -710,13 +714,13 @@ void WasmModuleBuilder::WriteTo(ZoneBuffer* buffer) const {
     buffer->write_u8(0);              // table index
     uint32_t first_element = 0;
     while (first_element < indirect_functions_.size() &&
-           indirect_functions_[first_element] == WasmElemSegment::kNullIndex) {
+           indirect_functions_[first_element] == kNullIndex) {
       first_element++;
     }
     uint32_t last_element =
         static_cast<uint32_t>(indirect_functions_.size() - 1);
     while (last_element >= first_element &&
-           indirect_functions_[last_element] == WasmElemSegment::kNullIndex) {
+           indirect_functions_[last_element] == kNullIndex) {
       last_element--;
     }
     buffer->write_u8(kExprI32Const);  // offset
diff --git a/chromium/v8/src/wasm/wasm-module-builder.h b/chromium/v8/src/wasm/wasm-module-builder.h
index f7b5ff1b768..c1d15a834ea 100644
--- a/chromium/v8/src/wasm/wasm-module-builder.h
+++ b/chromium/v8/src/wasm/wasm-module-builder.h
@@ -297,6 +297,8 @@ class V8_EXPORT_PRIVATE WasmModuleBuilder : public ZoneObject {
     return types_[exceptions_[index]].sig;
   }
 
+  static const uint32_t kNullIndex;
+
  private:
   struct Type {
     enum Kind { kFunctionSig, kStructType, kArrayType };
diff --git a/chromium/v8/src/wasm/wasm-module.cc b/chromium/v8/src/wasm/wasm-module.cc
index c336dc5f7d1..acebe8d0e5e 100644
--- a/chromium/v8/src/wasm/wasm-module.cc
+++ b/chromium/v8/src/wasm/wasm-module.cc
@@ -21,25 +21,23 @@
 #include "src/snapshot/snapshot.h"
 #include "src/wasm/module-decoder.h"
 #include "src/wasm/wasm-code-manager.h"
+#include "src/wasm/wasm-init-expr.h"
 #include "src/wasm/wasm-js.h"
 #include "src/wasm/wasm-objects-inl.h"
 #include "src/wasm/wasm-result.h"
+#include "src/wasm/wasm-subtyping.h"
 
 namespace v8 {
 namespace internal {
 namespace wasm {
 
-// static
-const uint32_t WasmElemSegment::kNullIndex;
-
 WireBytesRef LazilyGeneratedNames::LookupFunctionName(
-    const ModuleWireBytes& wire_bytes, uint32_t function_index,
-    Vector<const WasmExport> export_table) const {
+    const ModuleWireBytes& wire_bytes, uint32_t function_index) const {
   base::MutexGuard lock(&mutex_);
   if (!function_names_) {
     function_names_.reset(new std::unordered_map<uint32_t, WireBytesRef>());
     DecodeFunctionNames(wire_bytes.start(), wire_bytes.end(),
-                        function_names_.get(), export_table);
+                        function_names_.get());
   }
   auto it = function_names_->find(function_index);
   if (it == function_names_->end()) return WireBytesRef();
@@ -180,7 +178,7 @@ WasmName ModuleWireBytes::GetNameOrNull(WireBytesRef ref) const {
 WasmName ModuleWireBytes::GetNameOrNull(const WasmFunction* function,
                                         const WasmModule* module) const {
   return GetNameOrNull(module->lazily_generated_names.LookupFunctionName(
-      *this, function->func_index, VectorOf(module->export_table)));
+      *this, function->func_index));
 }
 
 std::ostream& operator<<(std::ostream& os, const WasmFunctionName& name) {
@@ -199,6 +197,8 @@ std::ostream& operator<<(std::ostream& os, const WasmFunctionName& name) {
 WasmModule::WasmModule(std::unique_ptr<Zone> signature_zone)
     : signature_zone(std::move(signature_zone)) {}
 
+WasmModule::~WasmModule() { DeleteCachedTypeJudgementsForModule(this); }
+
 bool IsWasmCodegenAllowed(Isolate* isolate, Handle<Context> context) {
   // TODO(wasm): Once wasm has its own CSP policy, we should introduce a
   // separate callback that includes information about the module about to be
diff --git a/chromium/v8/src/wasm/wasm-module.h b/chromium/v8/src/wasm/wasm-module.h
index bbfcf9623b5..d185e673412 100644
--- a/chromium/v8/src/wasm/wasm-module.h
+++ b/chromium/v8/src/wasm/wasm-module.h
@@ -16,10 +16,11 @@
 #include "src/common/globals.h"
 #include "src/handles/handles.h"
 #include "src/utils/vector.h"
+#include "src/wasm/branch-hint-map.h"
 #include "src/wasm/signature-map.h"
 #include "src/wasm/struct-types.h"
 #include "src/wasm/wasm-constants.h"
-#include "src/wasm/wasm-opcodes.h"
+#include "src/wasm/wasm-init-expr.h"
 
 namespace v8 {
 
@@ -107,30 +108,34 @@ struct WasmDataSegment {
 
 // Static representation of wasm element segment (table initializer).
 struct WasmElemSegment {
-  MOVE_ONLY_NO_DEFAULT_CONSTRUCTOR(WasmElemSegment);
-
   // Construct an active segment.
-  WasmElemSegment(uint32_t table_index, WasmInitExpr offset)
-      : type(kWasmFuncRef),
+  WasmElemSegment(ValueType type, uint32_t table_index, WasmInitExpr offset)
+      : type(type),
         table_index(table_index),
         offset(std::move(offset)),
         status(kStatusActive) {}
 
   // Construct a passive or declarative segment, which has no table index or
   // offset.
-  explicit WasmElemSegment(bool declarative)
-      : type(kWasmFuncRef),
+  WasmElemSegment(ValueType type, bool declarative)
+      : type(type),
         table_index(0),
         status(declarative ? kStatusDeclarative : kStatusPassive) {}
 
-  // Used in the {entries} vector to represent a `ref.null` entry in a passive
-  // segment.
-  V8_EXPORT_PRIVATE static const uint32_t kNullIndex = ~0u;
+  // Construct a passive or declarative segment, which has no table index or
+  // offset.
+  WasmElemSegment()
+      : type(kWasmBottom), table_index(0), status(kStatusActive) {}
+
+  WasmElemSegment(const WasmElemSegment&) = delete;
+  WasmElemSegment(WasmElemSegment&&) V8_NOEXCEPT = default;
+  WasmElemSegment& operator=(const WasmElemSegment&) = delete;
+  WasmElemSegment& operator=(WasmElemSegment&&) V8_NOEXCEPT = default;
 
   ValueType type;
   uint32_t table_index;
   WasmInitExpr offset;
-  std::vector<uint32_t> entries;
+  std::vector<WasmInitExpr> entries;
   enum Status {
     kStatusActive,      // copied automatically during instantiation.
     kStatusPassive,     // copied explicitly after instantiation.
@@ -188,8 +193,7 @@ struct ModuleWireBytes;
 class V8_EXPORT_PRIVATE LazilyGeneratedNames {
  public:
   WireBytesRef LookupFunctionName(const ModuleWireBytes& wire_bytes,
-                                  uint32_t function_index,
-                                  Vector<const WasmExport> export_table) const;
+                                  uint32_t function_index) const;
 
   void AddForTesting(int function_index, WireBytesRef name);
 
@@ -335,6 +339,7 @@ struct V8_EXPORT_PRIVATE WasmModule {
   std::vector<WasmException> exceptions;
   std::vector<WasmElemSegment> elem_segments;
   std::vector<WasmCompilationHint> compilation_hints;
+  BranchHintInfo branch_hints;
   SignatureMap signature_map;  // canonicalizing map for signature indexes.
 
   ModuleOrigin origin = kWasmOrigin;  // origin of the module
@@ -347,6 +352,7 @@ struct V8_EXPORT_PRIVATE WasmModule {
 
   explicit WasmModule(std::unique_ptr<Zone> signature_zone = nullptr);
   WasmModule(const WasmModule&) = delete;
+  ~WasmModule();
   WasmModule& operator=(const WasmModule&) = delete;
 };
 
diff --git a/chromium/v8/src/wasm/wasm-objects-inl.h b/chromium/v8/src/wasm/wasm-objects-inl.h
index 3da7e1650a1..e102fbd97fe 100644
--- a/chromium/v8/src/wasm/wasm-objects-inl.h
+++ b/chromium/v8/src/wasm/wasm-objects-inl.h
@@ -36,13 +36,14 @@ namespace internal {
 
 OBJECT_CONSTRUCTORS_IMPL(WasmExceptionObject, JSObject)
 TQ_OBJECT_CONSTRUCTORS_IMPL(WasmExceptionTag)
-OBJECT_CONSTRUCTORS_IMPL(WasmExportedFunctionData, Struct)
+OBJECT_CONSTRUCTORS_IMPL(WasmExportedFunctionData, WasmFunctionData)
 OBJECT_CONSTRUCTORS_IMPL(WasmGlobalObject, JSObject)
 OBJECT_CONSTRUCTORS_IMPL(WasmInstanceObject, JSObject)
 OBJECT_CONSTRUCTORS_IMPL(WasmMemoryObject, JSObject)
 OBJECT_CONSTRUCTORS_IMPL(WasmModuleObject, JSObject)
 OBJECT_CONSTRUCTORS_IMPL(WasmTableObject, JSObject)
 OBJECT_CONSTRUCTORS_IMPL(AsmWasmData, Struct)
+TQ_OBJECT_CONSTRUCTORS_IMPL(WasmFunctionData)
 TQ_OBJECT_CONSTRUCTORS_IMPL(WasmTypeInfo)
 TQ_OBJECT_CONSTRUCTORS_IMPL(WasmStruct)
 TQ_OBJECT_CONSTRUCTORS_IMPL(WasmArray)
@@ -55,6 +56,7 @@ CAST_ACCESSOR(WasmMemoryObject)
 CAST_ACCESSOR(WasmModuleObject)
 CAST_ACCESSOR(WasmTableObject)
 CAST_ACCESSOR(AsmWasmData)
+CAST_ACCESSOR(WasmFunctionData)
 CAST_ACCESSOR(WasmTypeInfo)
 CAST_ACCESSOR(WasmStruct)
 CAST_ACCESSOR(WasmArray)
@@ -329,18 +331,17 @@ WasmExportedFunction::WasmExportedFunction(Address ptr) : JSFunction(ptr) {
 }
 CAST_ACCESSOR(WasmExportedFunction)
 
+// WasmFunctionData
+ACCESSORS(WasmFunctionData, ref, Object, kRefOffset)
+
 // WasmExportedFunctionData
 ACCESSORS(WasmExportedFunctionData, wrapper_code, Code, kWrapperCodeOffset)
 ACCESSORS(WasmExportedFunctionData, instance, WasmInstanceObject,
           kInstanceOffset)
-SMI_ACCESSORS(WasmExportedFunctionData, jump_table_offset,
-              kJumpTableOffsetOffset)
 SMI_ACCESSORS(WasmExportedFunctionData, function_index, kFunctionIndexOffset)
 ACCESSORS(WasmExportedFunctionData, signature, Foreign, kSignatureOffset)
 SMI_ACCESSORS(WasmExportedFunctionData, wrapper_budget, kWrapperBudgetOffset)
 ACCESSORS(WasmExportedFunctionData, c_wrapper_code, Object, kCWrapperCodeOffset)
-ACCESSORS(WasmExportedFunctionData, wasm_call_target, Object,
-          kWasmCallTargetOffset)
 SMI_ACCESSORS(WasmExportedFunctionData, packed_args_size, kPackedArgsSizeOffset)
 
 wasm::FunctionSig* WasmExportedFunctionData::sig() const {
@@ -354,7 +355,7 @@ WasmJSFunction::WasmJSFunction(Address ptr) : JSFunction(ptr) {
 CAST_ACCESSOR(WasmJSFunction)
 
 // WasmJSFunctionData
-OBJECT_CONSTRUCTORS_IMPL(WasmJSFunctionData, Struct)
+OBJECT_CONSTRUCTORS_IMPL(WasmJSFunctionData, WasmFunctionData)
 CAST_ACCESSOR(WasmJSFunctionData)
 SMI_ACCESSORS(WasmJSFunctionData, serialized_return_count,
               kSerializedReturnCountOffset)
@@ -362,7 +363,6 @@ SMI_ACCESSORS(WasmJSFunctionData, serialized_parameter_count,
               kSerializedParameterCountOffset)
 ACCESSORS(WasmJSFunctionData, serialized_signature, PodArray<wasm::ValueType>,
           kSerializedSignatureOffset)
-ACCESSORS(WasmJSFunctionData, callable, JSReceiver, kCallableOffset)
 ACCESSORS(WasmJSFunctionData, wrapper_code, Code, kWrapperCodeOffset)
 ACCESSORS(WasmJSFunctionData, wasm_to_js_wrapper_code, Code,
           kWasmToJsWrapperCodeOffset)
@@ -416,13 +416,27 @@ wasm::StructType* WasmStruct::type(Map map) {
 wasm::StructType* WasmStruct::GcSafeType(Map map) {
   DCHECK_EQ(WASM_STRUCT_TYPE, map.instance_type());
   HeapObject raw = HeapObject::cast(map.constructor_or_back_pointer());
-  MapWord map_word = raw.map_word();
+  MapWord map_word = raw.map_word(kRelaxedLoad);
   HeapObject forwarded =
       map_word.IsForwardingAddress() ? map_word.ToForwardingAddress() : raw;
   Foreign foreign = Foreign::cast(forwarded);
   return reinterpret_cast<wasm::StructType*>(foreign.foreign_address());
 }
 
+int WasmStruct::Size(const wasm::StructType* type) {
+  // Object size must fit into a Smi (because of filler objects), and its
+  // computation must not overflow.
+  STATIC_ASSERT(Smi::kMaxValue <= kMaxInt);
+  DCHECK_LE(type->total_fields_size(), Smi::kMaxValue - kHeaderSize);
+  return std::max(kHeaderSize + static_cast<int>(type->total_fields_size()),
+                  Heap::kMinObjectSizeInTaggedWords * kTaggedSize);
+}
+
+int WasmStruct::GcSafeSize(Map map) {
+  wasm::StructType* type = GcSafeType(map);
+  return Size(type);
+}
+
 wasm::StructType* WasmStruct::type() const { return type(map()); }
 
 ObjectSlot WasmStruct::RawField(int raw_offset) {
@@ -439,7 +453,7 @@ wasm::ArrayType* WasmArray::type(Map map) {
 wasm::ArrayType* WasmArray::GcSafeType(Map map) {
   DCHECK_EQ(WASM_ARRAY_TYPE, map.instance_type());
   HeapObject raw = HeapObject::cast(map.constructor_or_back_pointer());
-  MapWord map_word = raw.map_word();
+  MapWord map_word = raw.map_word(kRelaxedLoad);
   HeapObject forwarded =
       map_word.IsForwardingAddress() ? map_word.ToForwardingAddress() : raw;
   Foreign foreign = Foreign::cast(forwarded);
@@ -460,12 +474,6 @@ int WasmArray::GcSafeSizeFor(Map map, int length) {
 
 void WasmTypeInfo::clear_foreign_address(Isolate* isolate) {
 #ifdef V8_HEAP_SANDBOX
-
-  // TODO(syg): V8_HEAP_SANDBOX doesn't work with pointer cage
-#ifdef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
-#error "V8_HEAP_SANDBOX requires per-Isolate pointer compression cage"
-#endif
-
   // Due to the type-specific pointer tags for external pointers, we need to
   // allocate an entry in the table here even though it will just store nullptr.
   AllocateExternalPointerEntries(isolate);
diff --git a/chromium/v8/src/wasm/wasm-objects.cc b/chromium/v8/src/wasm/wasm-objects.cc
index d4e7cb65a13..718124debf1 100644
--- a/chromium/v8/src/wasm/wasm-objects.cc
+++ b/chromium/v8/src/wasm/wasm-objects.cc
@@ -226,33 +226,21 @@ MaybeHandle<String> WasmModuleObject::GetFunctionNameOrNull(
   wasm::WireBytesRef name =
       module_object->module()->lazily_generated_names.LookupFunctionName(
           wasm::ModuleWireBytes(module_object->native_module()->wire_bytes()),
-          func_index, VectorOf(module_object->module()->export_table));
+          func_index);
   if (!name.is_set()) return {};
   return ExtractUtf8StringFromModuleBytes(isolate, module_object, name,
                                           kNoInternalize);
 }
 
-Handle<String> WasmModuleObject::GetFunctionName(
-    Isolate* isolate, Handle<WasmModuleObject> module_object,
-    uint32_t func_index) {
-  MaybeHandle<String> name =
-      GetFunctionNameOrNull(isolate, module_object, func_index);
-  if (!name.is_null()) return name.ToHandleChecked();
-  EmbeddedVector<char, 32> buffer;
-  DCHECK_GE(func_index, module_object->module()->num_imported_functions);
-  int length = SNPrintF(buffer, "func%u", func_index);
-  return isolate->factory()
-      ->NewStringFromOneByte(Vector<uint8_t>::cast(buffer.SubVector(0, length)))
-      .ToHandleChecked();
-}
-
-Vector<const uint8_t> WasmModuleObject::GetRawFunctionName(
-    uint32_t func_index) {
+Vector<const uint8_t> WasmModuleObject::GetRawFunctionName(int func_index) {
+  if (func_index == wasm::kAnonymousFuncIndex) {
+    return Vector<const uint8_t>({nullptr, 0});
+  }
   DCHECK_GT(module()->functions.size(), func_index);
   wasm::ModuleWireBytes wire_bytes(native_module()->wire_bytes());
   wasm::WireBytesRef name_ref =
-      module()->lazily_generated_names.LookupFunctionName(
-          wire_bytes, func_index, VectorOf(module()->export_table));
+      module()->lazily_generated_names.LookupFunctionName(wire_bytes,
+                                                          func_index);
   wasm::WasmName name = wire_bytes.GetNameOrNull(name_ref);
   return Vector<const uint8_t>::cast(name);
 }
@@ -454,21 +442,18 @@ void WasmTableObject::Set(Isolate* isolate, Handle<WasmTableObject> table,
     case wasm::HeapType::kEq:
     case wasm::HeapType::kData:
     case wasm::HeapType::kI31:
-      // TODO(7748): Implement once we have a story for struct/arrays/i31ref in
-      // JS.
-      UNIMPLEMENTED();
+      // TODO(7748): Implement once we have struct/arrays/i31ref tables.
+      UNREACHABLE();
     case wasm::HeapType::kBottom:
       UNREACHABLE();
     default:
       DCHECK(!table->instance().IsUndefined());
-      if (WasmInstanceObject::cast(table->instance())
-              .module()
-              ->has_signature(entry_index)) {
-        SetFunctionTableEntry(isolate, table, entries, entry_index, entry);
-        return;
-      }
-      // TODO(7748): Implement once we have a story for struct/arrays in JS.
-      UNIMPLEMENTED();
+      // TODO(7748): Relax this once we have struct/array/i31ref tables.
+      DCHECK(WasmInstanceObject::cast(table->instance())
+                 .module()
+                 ->has_signature(table->type().ref_index()));
+      SetFunctionTableEntry(isolate, table, entries, entry_index, entry);
+      return;
   }
 }
 
@@ -509,18 +494,16 @@ Handle<Object> WasmTableObject::Get(Isolate* isolate,
       UNREACHABLE();
     default:
       DCHECK(!table->instance().IsUndefined());
-      if (WasmInstanceObject::cast(table->instance())
-              .module()
-              ->has_signature(entry_index)) {
-        if (WasmExportedFunction::IsWasmExportedFunction(*entry) ||
-            WasmJSFunction::IsWasmJSFunction(*entry) ||
-            WasmCapiFunction::IsWasmCapiFunction(*entry)) {
-          return entry;
-        }
-        break;
+      // TODO(7748): Relax this once we have struct/array/i31ref tables.
+      DCHECK(WasmInstanceObject::cast(table->instance())
+                 .module()
+                 ->has_signature(table->type().ref_index()));
+      if (WasmExportedFunction::IsWasmExportedFunction(*entry) ||
+          WasmJSFunction::IsWasmJSFunction(*entry) ||
+          WasmCapiFunction::IsWasmCapiFunction(*entry)) {
+        return entry;
       }
-      // TODO(7748): Implement once we have a story for struct/arrays in JS.
-      UNIMPLEMENTED();
+      break;
   }
 
   // {entry} is not a valid entry in the table. It has to be a placeholder
@@ -1898,30 +1881,18 @@ Handle<WasmExportedFunction> WasmExportedFunction::New(
       (export_wrapper->is_builtin() &&
        export_wrapper->builtin_index() == Builtins::kGenericJSToWasmWrapper));
   int num_imported_functions = instance->module()->num_imported_functions;
-  int jump_table_offset = -1;
-  if (func_index >= num_imported_functions) {
-    uint32_t jump_table_diff =
-        instance->module_object().native_module()->GetJumpTableOffset(
-            func_index);
-    DCHECK_GE(kMaxInt, jump_table_diff);
-    jump_table_offset = static_cast<int>(jump_table_diff);
-  }
+  Handle<Object> ref =
+      func_index >= num_imported_functions
+          ? instance
+          : handle(instance->imported_function_refs().get(func_index), isolate);
+
   Factory* factory = isolate->factory();
   const wasm::FunctionSig* sig = instance->module()->functions[func_index].sig;
-  Handle<Foreign> sig_foreign =
-      factory->NewForeign(reinterpret_cast<Address>(sig));
+  Address call_target = instance->GetCallTarget(func_index);
   Handle<WasmExportedFunctionData> function_data =
-      Handle<WasmExportedFunctionData>::cast(factory->NewStruct(
-          WASM_EXPORTED_FUNCTION_DATA_TYPE, AllocationType::kOld));
-  function_data->set_wrapper_code(*export_wrapper);
-  function_data->set_instance(*instance);
-  function_data->set_jump_table_offset(jump_table_offset);
-  function_data->set_function_index(func_index);
-  function_data->set_signature(*sig_foreign);
-  function_data->set_wrapper_budget(wasm::kGenericWrapperBudget);
-  function_data->set_c_wrapper_code(Smi::zero(), SKIP_WRITE_BARRIER);
-  function_data->set_wasm_call_target(Smi::zero(), SKIP_WRITE_BARRIER);
-  function_data->set_packed_args_size(0);
+      factory->NewWasmExportedFunctionData(
+          export_wrapper, instance, call_target, ref, func_index,
+          reinterpret_cast<Address>(sig), wasm::kGenericWrapperBudget);
 
   MaybeHandle<String> maybe_name;
   bool is_asm_js_module = instance->module_object().is_asm_js();
@@ -2042,18 +2013,18 @@ Handle<WasmJSFunction> WasmJSFunction::New(Isolate* isolate,
   Handle<Code> wrapper_code =
       compiler::CompileJSToJSWrapper(isolate, sig, nullptr).ToHandleChecked();
 
+  // WasmJSFunctions use on-heap Code objects as call targets, so we can't
+  // cache the target address, unless the WasmJSFunction wraps a
+  // WasmExportedFunction.
+  Address call_target = kNullAddress;
+  if (WasmExportedFunction::IsWasmExportedFunction(*callable)) {
+    call_target = WasmExportedFunction::cast(*callable).GetWasmCallTarget();
+  }
+
   Factory* factory = isolate->factory();
-  Handle<WasmJSFunctionData> function_data = Handle<WasmJSFunctionData>::cast(
-      factory->NewStruct(WASM_JS_FUNCTION_DATA_TYPE, AllocationType::kOld));
-  function_data->set_serialized_return_count(return_count);
-  function_data->set_serialized_parameter_count(parameter_count);
-  function_data->set_serialized_signature(*serialized_sig);
-  function_data->set_callable(*callable);
-  function_data->set_wrapper_code(*wrapper_code);
-  // Use Abort() as a default value (it will never be called if not overwritten
-  // below).
-  function_data->set_wasm_to_js_wrapper_code(
-      isolate->heap()->builtin(Builtins::kAbort));
+  Handle<WasmJSFunctionData> function_data = factory->NewWasmJSFunctionData(
+      call_target, callable, return_count, parameter_count, serialized_sig,
+      wrapper_code);
 
   if (wasm::WasmFeatures::FromIsolate(isolate).has_typed_funcref()) {
     using CK = compiler::WasmImportCallKind;
@@ -2094,7 +2065,8 @@ Handle<WasmJSFunction> WasmJSFunction::New(Isolate* isolate,
 }
 
 JSReceiver WasmJSFunction::GetCallable() const {
-  return shared().wasm_js_function_data().callable();
+  return JSReceiver::cast(
+      Tuple2::cast(shared().wasm_js_function_data().ref()).value2());
 }
 
 const wasm::FunctionSig* WasmJSFunction::GetSignature(Zone* zone) {
@@ -2256,7 +2228,8 @@ bool TypecheckJSObject(Isolate* isolate, const WasmModule* module,
 
             if (WasmJSFunction::IsWasmJSFunction(*value)) {
               // Since a WasmJSFunction cannot refer to indexed types (definable
-              // only in a module), we do not need to use EquivalentTypes().
+              // only in a module), we do not need full function subtyping.
+              // TODO(manoskouk): Change this if wasm types can be exported.
               if (!WasmJSFunction::cast(*value).MatchesSignature(
                       module->signature(expected.ref_index()))) {
                 *error_message =
@@ -2268,11 +2241,12 @@ bool TypecheckJSObject(Isolate* isolate, const WasmModule* module,
             }
 
             if (WasmCapiFunction::IsWasmCapiFunction(*value)) {
+              // Since a WasmCapiFunction cannot refer to indexed types
+              // (definable only in a module), we do not need full function
+              // subtyping.
+              // TODO(manoskouk): Change this if wasm types can be exported.
               if (!WasmCapiFunction::cast(*value).MatchesSignature(
                       module->signature(expected.ref_index()))) {
-                // Since a WasmCapiFunction cannot refer to indexed types
-                // (definable in a module), we don't need to invoke
-                // IsEquivalentType();
                 *error_message =
                     "assigned WasmCapiFunction has to be a subtype of the "
                     "expected type";
diff --git a/chromium/v8/src/wasm/wasm-objects.h b/chromium/v8/src/wasm/wasm-objects.h
index 47bef60ac71..473c4725cc4 100644
--- a/chromium/v8/src/wasm/wasm-objects.h
+++ b/chromium/v8/src/wasm/wasm-objects.h
@@ -166,17 +166,11 @@ class WasmModuleObject : public JSObject {
                                                    Handle<WasmModuleObject>,
                                                    uint32_t func_index);
 
-  // Get the function name of the function identified by the given index.
-  // Returns "func[func_index]" if the function is unnamed or the
-  // name is not a valid UTF-8 string.
-  static Handle<String> GetFunctionName(Isolate*, Handle<WasmModuleObject>,
-                                        uint32_t func_index);
-
   // Get the raw bytes of the function name of the function identified by the
   // given index.
   // Meant to be used for debugging or frame printing.
   // Does not allocate, hence gc-safe.
-  Vector<const uint8_t> GetRawFunctionName(uint32_t func_index);
+  Vector<const uint8_t> GetRawFunctionName(int func_index);
 
   // Extract a portion of the wire bytes as UTF-8 string, optionally
   // internalized. (Prefer to internalize early if the string will be used for a
@@ -747,19 +741,31 @@ class WasmIndirectFunctionTable : public Struct {
   OBJECT_CONSTRUCTORS(WasmIndirectFunctionTable, Struct);
 };
 
+class WasmFunctionData
+    : public TorqueGeneratedWasmFunctionData<WasmFunctionData, Foreign> {
+ public:
+  DECL_ACCESSORS(ref, Object)
+
+  DECL_CAST(WasmFunctionData)
+  DECL_PRINTER(WasmFunctionData)
+
+  TQ_OBJECT_CONSTRUCTORS(WasmFunctionData)
+};
+
 // Information for a WasmExportedFunction which is referenced as the function
 // data of the SharedFunctionInfo underlying the function. For details please
 // see the {SharedFunctionInfo::HasWasmExportedFunctionData} predicate.
-class WasmExportedFunctionData : public Struct {
+class WasmExportedFunctionData : public WasmFunctionData {
  public:
   DECL_ACCESSORS(wrapper_code, Code)
+  // This is the instance that exported the function (which in case of
+  // imported and re-exported functions is different from the instance
+  // where the function is defined -- for the latter see WasmFunctionData::ref).
   DECL_ACCESSORS(instance, WasmInstanceObject)
-  DECL_INT_ACCESSORS(jump_table_offset)
   DECL_INT_ACCESSORS(function_index)
   DECL_ACCESSORS(signature, Foreign)
   DECL_INT_ACCESSORS(wrapper_budget)
   DECL_ACCESSORS(c_wrapper_code, Object)
-  DECL_ACCESSORS(wasm_call_target, Object)
   DECL_INT_ACCESSORS(packed_args_size)
 
   inline wasm::FunctionSig* sig() const;
@@ -772,21 +778,22 @@ class WasmExportedFunctionData : public Struct {
 
   // Layout description.
   DEFINE_FIELD_OFFSET_CONSTANTS(
-      HeapObject::kHeaderSize,
+      WasmFunctionData::kSize,
       TORQUE_GENERATED_WASM_EXPORTED_FUNCTION_DATA_FIELDS)
 
-  OBJECT_CONSTRUCTORS(WasmExportedFunctionData, Struct);
+  class BodyDescriptor;
+
+  OBJECT_CONSTRUCTORS(WasmExportedFunctionData, WasmFunctionData);
 };
 
 // Information for a WasmJSFunction which is referenced as the function data of
 // the SharedFunctionInfo underlying the function. For details please see the
 // {SharedFunctionInfo::HasWasmJSFunctionData} predicate.
-class WasmJSFunctionData : public Struct {
+class WasmJSFunctionData : public WasmFunctionData {
  public:
   DECL_INT_ACCESSORS(serialized_return_count)
   DECL_INT_ACCESSORS(serialized_parameter_count)
   DECL_ACCESSORS(serialized_signature, PodArray<wasm::ValueType>)
-  DECL_ACCESSORS(callable, JSReceiver)
   DECL_ACCESSORS(wrapper_code, Code)
   DECL_ACCESSORS(wasm_to_js_wrapper_code, Code)
 
@@ -797,10 +804,12 @@ class WasmJSFunctionData : public Struct {
   DECL_VERIFIER(WasmJSFunctionData)
 
   // Layout description.
-  DEFINE_FIELD_OFFSET_CONSTANTS(HeapObject::kHeaderSize,
+  DEFINE_FIELD_OFFSET_CONSTANTS(WasmFunctionData::kSize,
                                 TORQUE_GENERATED_WASM_JS_FUNCTION_DATA_FIELDS)
 
-  OBJECT_CONSTRUCTORS(WasmJSFunctionData, Struct);
+  class BodyDescriptor;
+
+  OBJECT_CONSTRUCTORS(WasmJSFunctionData, WasmFunctionData);
 };
 
 class WasmScript : public AllStatic {
@@ -915,6 +924,8 @@ class WasmStruct : public TorqueGeneratedWasmStruct<WasmStruct, HeapObject> {
   static inline wasm::StructType* type(Map map);
   inline wasm::StructType* type() const;
   static inline wasm::StructType* GcSafeType(Map map);
+  static inline int Size(const wasm::StructType* type);
+  static inline int GcSafeSize(Map map);
 
   inline ObjectSlot RawField(int raw_offset);
 
diff --git a/chromium/v8/src/wasm/wasm-objects.tq b/chromium/v8/src/wasm/wasm-objects.tq
index adcf63ba879..13911e590df 100644
--- a/chromium/v8/src/wasm/wasm-objects.tq
+++ b/chromium/v8/src/wasm/wasm-objects.tq
@@ -11,22 +11,31 @@ type ManagedWasmNativeModule extends Foreign
 
 extern class WasmInstanceObject extends JSObject;
 
-extern class WasmExportedFunctionData extends Struct {
+@generateCppClass
+extern class WasmFunctionData extends Foreign {
+  // This is the "reference" value that must be passed along in the "instance"
+  // register when calling the given function. It is either the target instance,
+  // or a pair holding the target instance and the callable; currently the
+  // latter is the case when the function being called is defined in JavaScript
+  // or via the C-API.
+  // For imported functions, this value equals the respective entry in
+  // the module's imported_function_refs array.
+  ref: WasmInstanceObject|Tuple2;
+}
+
+extern class WasmExportedFunctionData extends WasmFunctionData {
   wrapper_code: Code;
   instance: WasmInstanceObject;
-  jump_table_offset: Smi;
   function_index: Smi;
   signature: Foreign;
   wrapper_budget: Smi;
   // The remaining fields are for fast calling from C++. The contract is
   // that they are lazily populated, and either all will be present or none.
   c_wrapper_code: Object;
-  wasm_call_target: Smi|Foreign;
   packed_args_size: Smi;
 }
 
-extern class WasmJSFunctionData extends Struct {
-  callable: JSReceiver;
+extern class WasmJSFunctionData extends WasmFunctionData {
   wrapper_code: Code;
   wasm_to_js_wrapper_code: Code;
   serialized_return_count: Smi;
@@ -34,6 +43,7 @@ extern class WasmJSFunctionData extends Struct {
   serialized_signature: PodArrayOfWasmValueType;
 }
 
+// TODO(jkummerow): Derive from WasmFunctionData.
 @export
 class WasmCapiFunctionData extends HeapObject {
   call_target: RawPtr;
@@ -107,6 +117,8 @@ extern class AsmWasmData extends Struct {
 extern class WasmTypeInfo extends Foreign {
   supertypes: FixedArray;
   subtypes: ArrayList;
+  // In bytes, used for struct allocation.
+  instance_size: Smi;
 }
 
 @generateCppClass
diff --git a/chromium/v8/src/wasm/wasm-opcodes-inl.h b/chromium/v8/src/wasm/wasm-opcodes-inl.h
index 6b124b2dbc3..a63b46ee0e3 100644
--- a/chromium/v8/src/wasm/wasm-opcodes-inl.h
+++ b/chromium/v8/src/wasm/wasm-opcodes-inl.h
@@ -162,6 +162,7 @@ constexpr const char* WasmOpcodes::OpcodeName(WasmOpcode opcode) {
     CASE_OP(CallRef, "call_ref")
     CASE_OP(ReturnCallRef, "return_call_ref")
     CASE_OP(BrOnNull, "br_on_null")
+    CASE_OP(BrOnNonNull, "br_on_non_null")
     CASE_OP(Drop, "drop")
     CASE_OP(Select, "select")
     CASE_OP(SelectWithType, "select")
@@ -629,16 +630,12 @@ constexpr const FunctionSig* WasmOpcodes::Signature(WasmOpcode opcode) {
     case kNumericPrefix:
       return impl::kCachedSigs[impl::kNumericExprSigTable[opcode & 0xFF]];
     default:
-#if V8_HAS_CXX14_CONSTEXPR
       UNREACHABLE();  // invalid prefix.
-#else
-      return nullptr;
-#endif
   }
 }
 
 constexpr const FunctionSig* WasmOpcodes::AsmjsSignature(WasmOpcode opcode) {
-  CONSTEXPR_DCHECK(opcode < impl::kSimpleAsmjsExprSigTable.size());
+  DCHECK_GT(impl::kSimpleAsmjsExprSigTable.size(), opcode);
   return impl::kCachedSigs[impl::kSimpleAsmjsExprSigTable[opcode]];
 }
 
diff --git a/chromium/v8/src/wasm/wasm-opcodes.cc b/chromium/v8/src/wasm/wasm-opcodes.cc
index 94618077519..e4c0d19a058 100644
--- a/chromium/v8/src/wasm/wasm-opcodes.cc
+++ b/chromium/v8/src/wasm/wasm-opcodes.cc
@@ -35,9 +35,6 @@ std::ostream& operator<<(std::ostream& os, const FunctionSig& sig) {
 // https://chromium-review.googlesource.com/c/v8/v8/+/2413251).
 bool IsJSCompatibleSignature(const FunctionSig* sig, const WasmModule* module,
                              const WasmFeatures& enabled_features) {
-  if (!enabled_features.has_mv() && sig->return_count() > 1) {
-    return false;
-  }
   for (auto type : sig->all()) {
     // TODO(7748): Allow structs, arrays, and rtts when their JS-interaction is
     // decided on.
diff --git a/chromium/v8/src/wasm/wasm-opcodes.h b/chromium/v8/src/wasm/wasm-opcodes.h
index 909cacadd25..8bd8d1d4634 100644
--- a/chromium/v8/src/wasm/wasm-opcodes.h
+++ b/chromium/v8/src/wasm/wasm-opcodes.h
@@ -52,6 +52,7 @@ bool V8_EXPORT_PRIVATE IsJSCompatibleSignature(const FunctionSig* sig,
   V(Delegate, 0x18, _ /* eh_prototype */)       \
   V(CatchAll, 0x19, _ /* eh_prototype */)       \
   V(BrOnNull, 0xd4, _ /* gc prototype */)       \
+  V(BrOnNonNull, 0xd6, _ /* gc prototype */)    \
   V(NopForTestingUnsupportedInLiftoff, 0x16, _)
 
 // Constants, locals, globals, and calls.
@@ -252,37 +253,37 @@ bool V8_EXPORT_PRIVATE IsJSCompatibleSignature(const FunctionSig* sig,
 // These opcodes are not spec'ed (or visible) externally; the idea is
 // to use unused ranges for internal purposes.
 #define FOREACH_ASMJS_COMPAT_OPCODE(V) \
-  V(F64Acos, 0xc5, d_d)                \
-  V(F64Asin, 0xc6, d_d)                \
-  V(F64Atan, 0xc7, d_d)                \
-  V(F64Cos, 0xc8, d_d)                 \
-  V(F64Sin, 0xc9, d_d)                 \
-  V(F64Tan, 0xca, d_d)                 \
-  V(F64Exp, 0xcb, d_d)                 \
-  V(F64Log, 0xcc, d_d)                 \
-  V(F64Atan2, 0xcd, d_dd)              \
-  V(F64Pow, 0xce, d_dd)                \
-  V(F64Mod, 0xcf, d_dd)                \
+  V(F64Acos, 0xdc, d_d)                \
+  V(F64Asin, 0xdd, d_d)                \
+  V(F64Atan, 0xde, d_d)                \
+  V(F64Cos, 0xdf, d_d)                 \
+  V(F64Sin, 0xe0, d_d)                 \
+  V(F64Tan, 0xe1, d_d)                 \
+  V(F64Exp, 0xe2, d_d)                 \
+  V(F64Log, 0xe3, d_d)                 \
+  V(F64Atan2, 0xe4, d_dd)              \
+  V(F64Pow, 0xe5, d_dd)                \
+  V(F64Mod, 0xe6, d_dd)                \
   V(I32AsmjsDivS, 0xe7, i_ii)          \
   V(I32AsmjsDivU, 0xe8, i_ii)          \
   V(I32AsmjsRemS, 0xe9, i_ii)          \
-  V(I32AsmjsRemU, 0xd6, i_ii)          \
-  V(I32AsmjsLoadMem8S, 0xd7, i_i)      \
-  V(I32AsmjsLoadMem8U, 0xd8, i_i)      \
-  V(I32AsmjsLoadMem16S, 0xd9, i_i)     \
-  V(I32AsmjsLoadMem16U, 0xda, i_i)     \
-  V(I32AsmjsLoadMem, 0xdb, i_i)        \
-  V(F32AsmjsLoadMem, 0xdc, f_i)        \
-  V(F64AsmjsLoadMem, 0xdd, d_i)        \
-  V(I32AsmjsStoreMem8, 0xde, i_ii)     \
-  V(I32AsmjsStoreMem16, 0xdf, i_ii)    \
-  V(I32AsmjsStoreMem, 0xe0, i_ii)      \
-  V(F32AsmjsStoreMem, 0xe1, f_if)      \
-  V(F64AsmjsStoreMem, 0xe2, d_id)      \
-  V(I32AsmjsSConvertF32, 0xe3, i_f)    \
-  V(I32AsmjsUConvertF32, 0xe4, i_f)    \
-  V(I32AsmjsSConvertF64, 0xe5, i_d)    \
-  V(I32AsmjsUConvertF64, 0xe6, i_d)
+  V(I32AsmjsRemU, 0xea, i_ii)          \
+  V(I32AsmjsLoadMem8S, 0xeb, i_i)      \
+  V(I32AsmjsLoadMem8U, 0xec, i_i)      \
+  V(I32AsmjsLoadMem16S, 0xed, i_i)     \
+  V(I32AsmjsLoadMem16U, 0xee, i_i)     \
+  V(I32AsmjsLoadMem, 0xef, i_i)        \
+  V(F32AsmjsLoadMem, 0xf0, f_i)        \
+  V(F64AsmjsLoadMem, 0xf1, d_i)        \
+  V(I32AsmjsStoreMem8, 0xf2, i_ii)     \
+  V(I32AsmjsStoreMem16, 0xf3, i_ii)    \
+  V(I32AsmjsStoreMem, 0xf4, i_ii)      \
+  V(F32AsmjsStoreMem, 0xf5, f_if)      \
+  V(F64AsmjsStoreMem, 0xf6, d_id)      \
+  V(I32AsmjsSConvertF32, 0xf7, i_f)    \
+  V(I32AsmjsUConvertF32, 0xf8, i_f)    \
+  V(I32AsmjsSConvertF64, 0xf9, i_d)    \
+  V(I32AsmjsUConvertF64, 0xfa, i_d)
 
 #define FOREACH_SIMD_MEM_OPCODE(V) \
   V(S128LoadMem, 0xfd00, s_i)      \
@@ -759,10 +760,10 @@ bool V8_EXPORT_PRIVATE IsJSCompatibleSignature(const FunctionSig* sig,
   V(s_is, kWasmS128, kWasmI32, kWasmS128)
 
 #define FOREACH_PREFIX(V) \
+  V(GC, 0xfb)             \
   V(Numeric, 0xfc)        \
   V(Simd, 0xfd)           \
-  V(Atomic, 0xfe)         \
-  V(GC, 0xfb)
+  V(Atomic, 0xfe)
 
 enum WasmOpcode {
 // Declare expression opcodes.
@@ -801,129 +802,6 @@ class V8_EXPORT_PRIVATE WasmOpcodes {
   static inline const char* TrapReasonMessage(TrapReason);
 };
 
-// Representation of an initializer expression.
-class WasmInitExpr {
- public:
-  enum Operator {
-    kNone,
-    kGlobalGet,
-    kI32Const,
-    kI64Const,
-    kF32Const,
-    kF64Const,
-    kS128Const,
-    kRefNullConst,
-    kRefFuncConst,
-    kRttCanon,
-    kRttSub
-  };
-
-  union Immediate {
-    int32_t i32_const;
-    int64_t i64_const;
-    float f32_const;
-    double f64_const;
-    std::array<uint8_t, kSimd128Size> s128_const;
-    uint32_t index;
-    HeapType::Representation heap_type;
-  };
-
-  WasmInitExpr() : kind_(kNone) { immediate_.i32_const = 0; }
-  explicit WasmInitExpr(int32_t v) : kind_(kI32Const) {
-    immediate_.i32_const = v;
-  }
-  explicit WasmInitExpr(int64_t v) : kind_(kI64Const) {
-    immediate_.i64_const = v;
-  }
-  explicit WasmInitExpr(float v) : kind_(kF32Const) {
-    immediate_.f32_const = v;
-  }
-  explicit WasmInitExpr(double v) : kind_(kF64Const) {
-    immediate_.f64_const = v;
-  }
-  explicit WasmInitExpr(uint8_t v[kSimd128Size]) : kind_(kS128Const) {
-    base::Memcpy(immediate_.s128_const.data(), v, kSimd128Size);
-  }
-
-  MOVE_ONLY_NO_DEFAULT_CONSTRUCTOR(WasmInitExpr);
-
-  static WasmInitExpr GlobalGet(uint32_t index) {
-    WasmInitExpr expr;
-    expr.kind_ = kGlobalGet;
-    expr.immediate_.index = index;
-    return expr;
-  }
-
-  static WasmInitExpr RefFuncConst(uint32_t index) {
-    WasmInitExpr expr;
-    expr.kind_ = kRefFuncConst;
-    expr.immediate_.index = index;
-    return expr;
-  }
-
-  static WasmInitExpr RefNullConst(HeapType::Representation heap_type) {
-    WasmInitExpr expr;
-    expr.kind_ = kRefNullConst;
-    expr.immediate_.heap_type = heap_type;
-    return expr;
-  }
-
-  static WasmInitExpr RttCanon(uint32_t index) {
-    WasmInitExpr expr;
-    expr.kind_ = kRttCanon;
-    expr.immediate_.index = index;
-    return expr;
-  }
-
-  static WasmInitExpr RttSub(uint32_t index, WasmInitExpr supertype) {
-    WasmInitExpr expr;
-    expr.kind_ = kRttSub;
-    expr.immediate_.index = index;
-    expr.operand_ = std::make_unique<WasmInitExpr>(std::move(supertype));
-    return expr;
-  }
-
-  Immediate immediate() const { return immediate_; }
-  Operator kind() const { return kind_; }
-  WasmInitExpr* operand() const { return operand_.get(); }
-
-  bool operator==(const WasmInitExpr& other) const {
-    if (kind() != other.kind()) return false;
-    switch (kind()) {
-      case kNone:
-        return true;
-      case kGlobalGet:
-      case kRefFuncConst:
-      case kRttCanon:
-        return immediate().index == other.immediate().index;
-      case kI32Const:
-        return immediate().i32_const == other.immediate().i32_const;
-      case kI64Const:
-        return immediate().i64_const == other.immediate().i64_const;
-      case kF32Const:
-        return immediate().f32_const == other.immediate().f32_const;
-      case kF64Const:
-        return immediate().f64_const == other.immediate().f64_const;
-      case kS128Const:
-        return immediate().s128_const == other.immediate().s128_const;
-      case kRefNullConst:
-        return immediate().heap_type == other.immediate().heap_type;
-      case kRttSub:
-        return immediate().index == other.immediate().index &&
-               *operand() == *other.operand();
-    }
-  }
-
-  V8_INLINE bool operator!=(const WasmInitExpr& other) {
-    return !(*this == other);
-  }
-
- private:
-  Immediate immediate_;
-  Operator kind_;
-  std::unique_ptr<WasmInitExpr> operand_ = nullptr;
-};
-
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
diff --git a/chromium/v8/src/wasm/wasm-serialization.cc b/chromium/v8/src/wasm/wasm-serialization.cc
index b2e6f0c4d8a..a47e420cb11 100644
--- a/chromium/v8/src/wasm/wasm-serialization.cc
+++ b/chromium/v8/src/wasm/wasm-serialization.cc
@@ -567,6 +567,8 @@ class CopyAndRelocTask : public JobTask {
 
   void Run(JobDelegate* delegate) override {
     CODE_SPACE_WRITE_SCOPE
+    NativeModuleModificationScope native_module_modification_scope(
+        deserializer_->native_module_);
     do {
       auto batch = from_queue_->Pop();
       if (batch.empty()) break;
@@ -712,11 +714,9 @@ DeserializationUnit NativeModuleDeserializer::ReadCode(int fn_index,
     constexpr size_t kMaxReservation =
         RoundUp<kCodeAlignment>(WasmCodeAllocator::kMaxCodeSpaceSize * 9 / 10);
     size_t code_space_size = std::min(kMaxReservation, remaining_code_size_);
-    current_code_space_ =
+    std::tie(current_code_space_, current_jump_tables_) =
         native_module_->AllocateForDeserializedCode(code_space_size);
     DCHECK_EQ(current_code_space_.size(), code_space_size);
-    current_jump_tables_ = native_module_->FindJumpTablesForRegion(
-        base::AddressRegionOf(current_code_space_));
     DCHECK(current_jump_tables_.is_valid());
   }
 
diff --git a/chromium/v8/src/wasm/wasm-subtyping.cc b/chromium/v8/src/wasm/wasm-subtyping.cc
index b0e8105a605..d2b7e9fe31d 100644
--- a/chromium/v8/src/wasm/wasm-subtyping.cc
+++ b/chromium/v8/src/wasm/wasm-subtyping.cc
@@ -91,6 +91,26 @@ class TypeJudgementCache {
     type_equivalence_cache_.erase(
         std::make_tuple(type1, type2, module1, module2));
   }
+  void delete_module(const WasmModule* module) {
+    for (auto iterator = type_equivalence_cache_.begin();
+         iterator != type_equivalence_cache_.end();) {
+      if (std::get<2>(*iterator) == module ||
+          std::get<3>(*iterator) == module) {
+        iterator = type_equivalence_cache_.erase(iterator);
+      } else {
+        iterator++;
+      }
+    }
+    for (auto iterator = subtyping_cache_.begin();
+         iterator != subtyping_cache_.end();) {
+      if (std::get<2>(*iterator) == module ||
+          std::get<3>(*iterator) == module) {
+        iterator = subtyping_cache_.erase(iterator);
+      } else {
+        iterator++;
+      }
+    }
+  }
 
  private:
   Zone zone_;
@@ -258,14 +278,46 @@ bool ArrayIsSubtypeOf(uint32_t subtype_index, uint32_t supertype_index,
   }
 }
 
-// TODO(7748): Expand this with function subtyping when it is introduced.
 bool FunctionIsSubtypeOf(uint32_t subtype_index, uint32_t supertype_index,
                          const WasmModule* sub_module,
                          const WasmModule* super_module) {
-  return FunctionEquivalentIndices(subtype_index, supertype_index, sub_module,
-                                   super_module);
-}
+  if (!FLAG_experimental_wasm_gc) {
+    return FunctionEquivalentIndices(subtype_index, supertype_index, sub_module,
+                                     super_module);
+  }
+  const FunctionSig* sub_func = sub_module->types[subtype_index].function_sig;
+  const FunctionSig* super_func =
+      super_module->types[supertype_index].function_sig;
+
+  if (sub_func->parameter_count() != super_func->parameter_count() ||
+      sub_func->return_count() != super_func->return_count()) {
+    return false;
+  }
+
+  TypeJudgementCache::instance()->cache_subtype(subtype_index, supertype_index,
+                                                sub_module, super_module);
+
+  for (uint32_t i = 0; i < sub_func->parameter_count(); i++) {
+    // Contravariance for params.
+    if (!IsSubtypeOf(super_func->parameters()[i], sub_func->parameters()[i],
+                     super_module, sub_module)) {
+      TypeJudgementCache::instance()->uncache_subtype(
+          subtype_index, supertype_index, sub_module, super_module);
+      return false;
+    }
+  }
+  for (uint32_t i = 0; i < sub_func->return_count(); i++) {
+    // Covariance for returns.
+    if (!IsSubtypeOf(sub_func->returns()[i], super_func->returns()[i],
+                     sub_module, super_module)) {
+      TypeJudgementCache::instance()->uncache_subtype(
+          subtype_index, supertype_index, sub_module, super_module);
+      return false;
+    }
+  }
 
+  return true;
+}
 }  // namespace
 
 V8_NOINLINE V8_EXPORT_PRIVATE bool IsSubtypeOfImpl(
@@ -403,11 +455,12 @@ V8_NOINLINE bool EquivalentTypes(ValueType type1, ValueType type2,
                            module2);
 }
 
-ValueType CommonSubtype(ValueType a, ValueType b, const WasmModule* module) {
-  if (a == b) return a;
-  if (IsSubtypeOf(a, b, module)) return a;
-  if (IsSubtypeOf(b, a, module)) return b;
-  return kWasmBottom;
+void DeleteCachedTypeJudgementsForModule(const WasmModule* module) {
+  // Accessing the caches for subtyping and equivalence from multiple background
+  // threads is protected by a lock.
+  base::RecursiveMutexGuard type_cache_access(
+      TypeJudgementCache::instance()->type_cache_mutex());
+  TypeJudgementCache::instance()->delete_module(module);
 }
 
 }  // namespace wasm
diff --git a/chromium/v8/src/wasm/wasm-subtyping.h b/chromium/v8/src/wasm/wasm-subtyping.h
index 0c35f7c4708..59e7935d1f1 100644
--- a/chromium/v8/src/wasm/wasm-subtyping.h
+++ b/chromium/v8/src/wasm/wasm-subtyping.h
@@ -60,8 +60,10 @@ V8_NOINLINE bool EquivalentTypes(ValueType type1, ValueType type2,
 // - Struct subtyping: Subtype must have at least as many fields as supertype,
 //   covariance for immutable fields, equivalence for mutable fields.
 // - Array subtyping (mutable only) is the equivalence relation.
-// - Function subtyping is the equivalence relation (note: this rule might
-//   change in the future to include type variance).
+// - Function subtyping depends on the enabled wasm features: if
+//   --experimental-wasm-gc is enabled, then subtyping is computed
+//   contravariantly for parameter types and covariantly for return types.
+//   Otherwise, the subtyping relation is the equivalence relation.
 V8_INLINE bool IsSubtypeOf(ValueType subtype, ValueType supertype,
                            const WasmModule* sub_module,
                            const WasmModule* super_module) {
@@ -91,11 +93,9 @@ V8_INLINE bool IsHeapSubtypeOf(uint32_t subtype_index, uint32_t supertype_index,
                      ValueType::Ref(supertype_index, kNonNullable), module);
 }
 
-// Returns the weakest type that is a subtype of both a and b
-// (which is currently always one of a, b, or kWasmBottom).
-// TODO(manoskouk): Update this once we have settled on a type system for
-// reference types.
-ValueType CommonSubtype(ValueType a, ValueType b, const WasmModule* module);
+// Call this function in {module}'s destructor to avoid spurious cache hits in
+// case another WasmModule gets allocated in the same address later.
+void DeleteCachedTypeJudgementsForModule(const WasmModule* module);
 
 }  // namespace wasm
 }  // namespace internal
diff --git a/chromium/v8/src/wasm/wasm-value.h b/chromium/v8/src/wasm/wasm-value.h
index 0a1d2b69e25..faaad180760 100644
--- a/chromium/v8/src/wasm/wasm-value.h
+++ b/chromium/v8/src/wasm/wasm-value.h
@@ -12,7 +12,7 @@
 #include "src/base/memory.h"
 #include "src/handles/handles.h"
 #include "src/utils/boxed-float.h"
-#include "src/wasm/wasm-opcodes.h"
+#include "src/wasm/value-type.h"
 #include "src/zone/zone-containers.h"
 
 namespace v8 {
diff --git a/chromium/v8/src/web-snapshot/web-snapshot.cc b/chromium/v8/src/web-snapshot/web-snapshot.cc
index 16bbc9af3e4..f36698a351e 100644
--- a/chromium/v8/src/web-snapshot/web-snapshot.cc
+++ b/chromium/v8/src/web-snapshot/web-snapshot.cc
@@ -11,6 +11,7 @@
 #include "src/base/platform/wrappers.h"
 #include "src/handles/handles.h"
 #include "src/objects/contexts.h"
+#include "src/objects/js-regexp-inl.h"
 #include "src/objects/script.h"
 
 namespace v8 {
@@ -34,8 +35,8 @@ void WebSnapshotSerializerDeserializer::Throw(const char* message) {
   error_message_ = message;
   if (!isolate_->has_pending_exception()) {
     v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(isolate_);
-    v8_isolate->ThrowException(v8::Exception::Error(
-        v8::String::NewFromUtf8(v8_isolate, message).ToLocalChecked()));
+    v8_isolate->ThrowError(
+        v8::String::NewFromUtf8(v8_isolate, message).ToLocalChecked());
   }
 }
 
@@ -238,7 +239,10 @@ void WebSnapshotSerializer::SerializeMap(Handle<Map> map, uint32_t& id) {
 
 // Format (serialized function):
 // - 0 if there's no context, 1 + context id otherwise
-// - String id (source string)
+// - String id (source snippet)
+// - Start position in the source snippet
+// - Length in the source snippet
+// TODO(v8:11525): Investigate whether the length is really needed.
 void WebSnapshotSerializer::SerializeFunction(Handle<JSFunction> function,
                                               uint32_t& id) {
   if (InsertIntoIndexMap(function_ids_, function, id)) {
@@ -251,7 +255,7 @@ void WebSnapshotSerializer::SerializeFunction(Handle<JSFunction> function,
   }
 
   Handle<Context> context(function->context(), isolate_);
-  if (context->IsNativeContext()) {
+  if (context->IsNativeContext() || context->IsScriptContext()) {
     function_serializer_.WriteUint32(0);
   } else {
     DCHECK(context->IsFunctionContext());
@@ -260,20 +264,19 @@ void WebSnapshotSerializer::SerializeFunction(Handle<JSFunction> function,
     function_serializer_.WriteUint32(context_id + 1);
   }
 
-  // TODO(v8:11525): For inner functions which occur inside a serialized
-  // function, create a "substring" type, so that we don't need to serialize the
-  // same content twice.
+  // TODO(v8:11525): Don't write the full source but instead, a set of minimal
+  // snippets which cover the serialized functions.
   Handle<String> full_source(
       String::cast(Script::cast(function->shared().script()).source()),
       isolate_);
-  int start = function->shared().StartPosition();
-  int end = function->shared().EndPosition();
-  Handle<String> source =
-      isolate_->factory()->NewSubString(full_source, start, end);
   uint32_t source_id = 0;
-  SerializeString(source, source_id);
+  SerializeString(full_source, source_id);
   function_serializer_.WriteUint32(source_id);
 
+  int start = function->shared().StartPosition();
+  function_serializer_.WriteUint32(start);
+  int end = function->shared().EndPosition();
+  function_serializer_.WriteUint32(end - start);
   // TODO(v8:11525): Serialize .prototype.
   // TODO(v8:11525): Support properties in functions.
 }
@@ -297,7 +300,8 @@ void WebSnapshotSerializer::SerializeContext(Handle<Context> context,
   }
 
   uint32_t parent_context_id = 0;
-  if (!context->previous().IsNativeContext()) {
+  if (!context->previous().IsNativeContext() &&
+      !context->previous().IsScriptContext()) {
     SerializeContext(handle(context->previous(), isolate_), parent_context_id);
     ++parent_context_id;
   }
@@ -387,18 +391,35 @@ void WebSnapshotSerializer::WriteValue(Handle<Object> object,
                                        ValueSerializer& serializer) {
   uint32_t id = 0;
   if (object->IsSmi()) {
-    // TODO(v8:11525): Implement.
-    UNREACHABLE();
+    serializer.WriteUint32(ValueType::INTEGER);
+    serializer.WriteZigZag<int32_t>(Smi::cast(*object).value());
+    return;
   }
 
   DCHECK(object->IsHeapObject());
   switch (HeapObject::cast(*object).map().instance_type()) {
     case ODDBALL_TYPE:
-      // TODO(v8:11525): Implement.
-      UNREACHABLE();
+      switch (Oddball::cast(*object).kind()) {
+        case Oddball::kFalse:
+          serializer.WriteUint32(ValueType::FALSE_CONSTANT);
+          return;
+        case Oddball::kTrue:
+          serializer.WriteUint32(ValueType::TRUE_CONSTANT);
+          return;
+        case Oddball::kNull:
+          serializer.WriteUint32(ValueType::NULL_CONSTANT);
+          return;
+        case Oddball::kUndefined:
+          serializer.WriteUint32(ValueType::UNDEFINED_CONSTANT);
+          return;
+        default:
+          UNREACHABLE();
+      }
     case HEAP_NUMBER_TYPE:
-      // TODO(v8:11525): Implement.
-      UNREACHABLE();
+      // TODO(v8:11525): Handle possible endianness mismatch.
+      serializer.WriteUint32(ValueType::DOUBLE);
+      serializer.WriteDouble(HeapNumber::cast(*object).value());
+      break;
     case JS_FUNCTION_TYPE:
       SerializeFunction(Handle<JSFunction>::cast(object), id);
       serializer.WriteUint32(ValueType::FUNCTION_ID);
@@ -409,6 +430,23 @@ void WebSnapshotSerializer::WriteValue(Handle<Object> object,
       serializer.WriteUint32(ValueType::OBJECT_ID);
       serializer.WriteUint32(id);
       break;
+    case JS_REG_EXP_TYPE: {
+      Handle<JSRegExp> regexp = Handle<JSRegExp>::cast(object);
+      if (regexp->map() != isolate_->regexp_function()->initial_map()) {
+        Throw("Web snapshot: Unsupported RegExp map");
+        return;
+      }
+      uint32_t pattern_id, flags_id;
+      Handle<String> pattern = handle(regexp->Pattern(), isolate_);
+      Handle<String> flags_string =
+          JSRegExp::StringFromFlags(isolate_, regexp->GetFlags());
+      SerializeString(pattern, pattern_id);
+      SerializeString(flags_string, flags_id);
+      serializer.WriteUint32(ValueType::REGEXP);
+      serializer.WriteUint32(pattern_id);
+      serializer.WriteUint32(flags_id);
+      break;
+    }
     default:
       if (object->IsString()) {
         SerializeString(Handle<String>::cast(object), id);
@@ -669,8 +707,21 @@ void WebSnapshotDeserializer::DeserializeFunctions() {
     Throw("Web snapshot: Malformed function table");
     return;
   }
-  STATIC_ASSERT(kMaxItemCount <= FixedArray::kMaxLength);
+  STATIC_ASSERT(kMaxItemCount + 1 <= FixedArray::kMaxLength);
   functions_ = isolate_->factory()->NewFixedArray(function_count_);
+
+  Handle<Script> script =
+      isolate_->factory()->NewScript(isolate_->factory()->empty_string());
+  script->set_type(Script::TYPE_WEB_SNAPSHOT);
+  // Overallocate the array for SharedFunctionInfos; functions which we
+  // deserialize soon will create more SharedFunctionInfos when called.
+  Handle<WeakFixedArray> infos(isolate_->factory()->NewWeakFixedArray(
+      WeakArrayList::CapacityForLength(function_count_ + 1),
+      AllocationType::kOld));
+  script->set_shared_function_infos(*infos);
+  Handle<ObjectHashTable> shared_function_info_table =
+      ObjectHashTable::New(isolate_, function_count_);
+
   for (uint32_t i = 0; i < function_count_; ++i) {
     uint32_t context_id;
     // Note: > (not >= on purpose, we will subtract 1).
@@ -681,10 +732,24 @@ void WebSnapshotDeserializer::DeserializeFunctions() {
     }
 
     Handle<String> source = ReadString(false);
+    if (i == 0) {
+      script->set_source(*source);
+    } else {
+      // TODO(v8:11525): Support multiple source snippets.
+      DCHECK_EQ(script->source(), *source);
+    }
+
+    uint32_t start_position;
+    uint32_t length;
+    if (!deserializer_->ReadUint32(&start_position) ||
+        !deserializer_->ReadUint32(&length)) {
+      Throw("Web snapshot: Malformed function");
+      return;
+    }
 
     // TODO(v8:11525): Support other function kinds.
     // TODO(v8:11525): Support (exported) top level functions.
-    Handle<Script> script = isolate_->factory()->NewScript(source);
+
     // TODO(v8:11525): Deduplicate the SFIs for inner functions the user creates
     // post-deserialization (by calling the outer function, if it's also in the
     // snapshot) against the ones we create here.
@@ -692,18 +757,24 @@ void WebSnapshotDeserializer::DeserializeFunctions() {
         isolate_->factory()->NewSharedFunctionInfo(
             isolate_->factory()->empty_string(), MaybeHandle<Code>(),
             Builtins::kCompileLazy, FunctionKind::kNormalFunction);
-    shared->set_function_literal_id(1);
+    shared->set_script(*script);
+    // Index 0 is reserved for top-level shared function info (which web
+    // snapshot scripts don't have).
+    const int shared_function_info_index = i + 1;
+    shared->set_function_literal_id(shared_function_info_index);
     // TODO(v8:11525): Decide how to handle language modes.
     shared->set_language_mode(LanguageMode::kStrict);
     shared->set_uncompiled_data(
         *isolate_->factory()->NewUncompiledDataWithoutPreparseData(
-            ReadOnlyRoots(isolate_).empty_string_handle(), 0,
-            source->length()));
-    shared->set_script(*script);
-    Handle<WeakFixedArray> infos(
-        isolate_->factory()->NewWeakFixedArray(3, AllocationType::kOld));
-    infos->Set(1, HeapObjectReference::Weak(*shared));
-    script->set_shared_function_infos(*infos);
+            ReadOnlyRoots(isolate_).empty_string_handle(), start_position,
+            start_position + length));
+    shared->set_allows_lazy_compilation(true);
+    infos->Set(shared_function_info_index, HeapObjectReference::Weak(*shared));
+
+    shared_function_info_table = ObjectHashTable::Put(
+        shared_function_info_table,
+        handle(Smi::FromInt(start_position), isolate_),
+        handle(Smi::FromInt(shared_function_info_index), isolate_));
 
     Handle<JSFunction> function =
         Factory::JSFunctionBuilder(isolate_, shared, isolate_->native_context())
@@ -718,6 +789,7 @@ void WebSnapshotDeserializer::DeserializeFunctions() {
     }
     functions_->set(i, *function);
   }
+  script->set_shared_function_info_table(*shared_function_info_table);
 }
 
 void WebSnapshotDeserializer::DeserializeObjects() {
@@ -806,6 +878,46 @@ void WebSnapshotDeserializer::ReadValue(Handle<Object>& value,
     return;
   }
   switch (value_type) {
+    case ValueType::FALSE_CONSTANT: {
+      value = handle(ReadOnlyRoots(isolate_).false_value(), isolate_);
+      representation = Representation::Tagged();
+      break;
+    }
+    case ValueType::TRUE_CONSTANT: {
+      value = handle(ReadOnlyRoots(isolate_).true_value(), isolate_);
+      representation = Representation::Tagged();
+      break;
+    }
+    case ValueType::NULL_CONSTANT: {
+      value = handle(ReadOnlyRoots(isolate_).null_value(), isolate_);
+      representation = Representation::Tagged();
+      break;
+    }
+    case ValueType::UNDEFINED_CONSTANT: {
+      value = handle(ReadOnlyRoots(isolate_).undefined_value(), isolate_);
+      representation = Representation::Tagged();
+      break;
+    }
+    case ValueType::INTEGER: {
+      Maybe<int32_t> number = deserializer_->ReadZigZag<int32_t>();
+      if (number.IsNothing()) {
+        Throw("Web snapshot: Malformed integer");
+        return;
+      }
+      value = isolate_->factory()->NewNumberFromInt(number.FromJust());
+      representation = Representation::Tagged();
+      break;
+    }
+    case ValueType::DOUBLE: {
+      double number;
+      if (!deserializer_->ReadDouble(&number)) {
+        Throw("Web snapshot: Malformed double");
+        return;
+      }
+      value = isolate_->factory()->NewNumber(number);
+      representation = Representation::Tagged();
+      break;
+    }
     case ValueType::STRING_ID: {
       value = ReadString(false);
       representation = Representation::Tagged();
@@ -834,6 +946,25 @@ void WebSnapshotDeserializer::ReadValue(Handle<Object>& value,
       value = handle(functions_->get(function_id), isolate_);
       representation = Representation::Tagged();
       break;
+    case ValueType::REGEXP: {
+      Handle<String> pattern = ReadString(false);
+      Handle<String> flags_string = ReadString(false);
+      bool success = false;
+      JSRegExp::Flags flags =
+          JSRegExp::FlagsFromString(isolate_, flags_string, &success);
+      if (!success) {
+        Throw("Web snapshot: Malformed flags in regular expression");
+        return;
+      }
+      MaybeHandle<JSRegExp> maybe_regexp =
+          JSRegExp::New(isolate_, pattern, flags);
+      if (!maybe_regexp.ToHandle(&value)) {
+        Throw("Web snapshot: Malformed RegExp");
+        return;
+      }
+      representation = Representation::Tagged();
+      break;
+    }
     default:
       // TODO(v8:11525): Handle other value types.
       Throw("Web snapshot: Unsupported value type");
diff --git a/chromium/v8/src/web-snapshot/web-snapshot.h b/chromium/v8/src/web-snapshot/web-snapshot.h
index 31461c8dbc5..8127fa7aa8d 100644
--- a/chromium/v8/src/web-snapshot/web-snapshot.h
+++ b/chromium/v8/src/web-snapshot/web-snapshot.h
@@ -38,11 +38,22 @@ class WebSnapshotSerializerDeserializer {
   inline bool has_error() const { return error_message_ != nullptr; }
   const char* error_message() const { return error_message_; }
 
-  enum ValueType : uint8_t { STRING_ID, OBJECT_ID, FUNCTION_ID };
+  enum ValueType : uint8_t {
+    FALSE_CONSTANT,
+    TRUE_CONSTANT,
+    NULL_CONSTANT,
+    UNDEFINED_CONSTANT,
+    INTEGER,
+    DOUBLE,
+    STRING_ID,
+    OBJECT_ID,
+    FUNCTION_ID,
+    REGEXP
+  };
 
   // The maximum count of items for each value type (strings, objects etc.)
   static constexpr uint32_t kMaxItemCount =
-      static_cast<uint32_t>(FixedArray::kMaxLength);
+      static_cast<uint32_t>(FixedArray::kMaxLength - 1);
   // This ensures indices and lengths can be converted between uint32_t and int
   // without problems:
   STATIC_ASSERT(kMaxItemCount < std::numeric_limits<int32_t>::max());
diff --git a/chromium/v8/src/zone/zone-segment.cc b/chromium/v8/src/zone/zone-segment.cc
index 49cedb851b8..6b682624dce 100644
--- a/chromium/v8/src/zone/zone-segment.cc
+++ b/chromium/v8/src/zone/zone-segment.cc
@@ -4,7 +4,7 @@
 
 #include "src/zone/zone-segment.h"
 
-#include "src/sanitizer/msan.h"
+#include "src/base/sanitizer/msan.h"
 
 namespace v8 {
 namespace internal {
diff --git a/chromium/v8/src/zone/zone.cc b/chromium/v8/src/zone/zone.cc
index e40b92be68a..40cf1ab2df8 100644
--- a/chromium/v8/src/zone/zone.cc
+++ b/chromium/v8/src/zone/zone.cc
@@ -7,8 +7,8 @@
 #include <cstring>
 #include <memory>
 
+#include "src/base/sanitizer/asan.h"
 #include "src/init/v8.h"
-#include "src/sanitizer/asan.h"
 #include "src/utils/utils.h"
 #include "src/zone/type-stats.h"
 
diff --git a/chromium/v8/test/benchmarks/cpp/BUILD.gn b/chromium/v8/test/benchmarks/cpp/BUILD.gn
index 6c579528414..07eeb94f159 100644
--- a/chromium/v8/test/benchmarks/cpp/BUILD.gn
+++ b/chromium/v8/test/benchmarks/cpp/BUILD.gn
@@ -25,6 +25,9 @@ if (v8_enable_google_benchmark) {
 
     sources = [ "empty.cc" ]
 
-    deps = [ "//third_party/google_benchmark:benchmark_main" ]
+    deps = [
+      "//:v8_libbase",
+      "//third_party/google_benchmark:benchmark_main",
+    ]
   }
 }
diff --git a/chromium/v8/test/cctest/BUILD.gn b/chromium/v8/test/cctest/BUILD.gn
index ffa4e3a136a..8f6e5610b84 100644
--- a/chromium/v8/test/cctest/BUILD.gn
+++ b/chromium/v8/test/cctest/BUILD.gn
@@ -127,6 +127,7 @@ v8_source_set("cctest_sources") {
     "compiler/test-run-unwinding-info.cc",
     "compiler/test-run-variables.cc",
     "compiler/test-sloppy-equality.cc",
+    "compiler/test-verify-type.cc",
     "compiler/value-helper.cc",
     "compiler/value-helper.h",
     "disasm-regex-helper.cc",
@@ -156,6 +157,7 @@ v8_source_set("cctest_sources") {
     "heap/test-mark-compact.cc",
     "heap/test-memory-measurement.cc",
     "heap/test-page-promotion.cc",
+    "heap/test-shared-heap.cc",
     "heap/test-spaces.cc",
     "heap/test-unmapper.cc",
     "heap/test-weak-references.cc",
@@ -260,6 +262,7 @@ v8_source_set("cctest_sources") {
     "test-platform.cc",
     "test-profile-generator.cc",
     "test-property-details.cc",
+    "test-ptr-compr-cage.cc",
     "test-random-number-generator.cc",
     "test-regexp.cc",
     "test-representation.cc",
@@ -438,7 +441,6 @@ v8_source_set("cctest_sources") {
       "wasm/test-run-wasm-relaxed-simd.cc",
       "wasm/test-run-wasm-sign-extension.cc",
       "wasm/test-run-wasm-simd-liftoff.cc",
-      "wasm/test-run-wasm-simd-scalar-lowering.cc",
       "wasm/test-run-wasm-simd.cc",
       "wasm/test-run-wasm-wrappers.cc",
       "wasm/test-run-wasm.cc",
diff --git a/chromium/v8/test/mjsunit/BUILD.gn b/chromium/v8/test/mjsunit/BUILD.gn
index 1acef4ef642..2bdfd797d5b 100644
--- a/chromium/v8/test/mjsunit/BUILD.gn
+++ b/chromium/v8/test/mjsunit/BUILD.gn
@@ -24,14 +24,10 @@ group("v8_mjsunit") {
     "../../tools/profile.mjs",
     "../../tools/profile_view.mjs",
     "../../tools/splaytree.mjs",
-    "../../tools/system-analyzer/helper.mjs",
-    "../../tools/system-analyzer/log/api.mjs",
-    "../../tools/system-analyzer/log/code.mjs",
-    "../../tools/system-analyzer/log/ic.mjs",
-    "../../tools/system-analyzer/log/log.mjs",
-    "../../tools/system-analyzer/log/map.mjs",
+    "../../tools/system-analyzer/log/",
     "../../tools/system-analyzer/processor.mjs",
     "../../tools/system-analyzer/timeline.mjs",
+    "../../tools/system-analyzer/helper.mjs",
     "../../tools/tickprocessor.mjs",
   ]
 }
diff --git a/chromium/v8/test/unittests/BUILD.gn b/chromium/v8/test/unittests/BUILD.gn
index 43858603dcb..f47b4994133 100644
--- a/chromium/v8/test/unittests/BUILD.gn
+++ b/chromium/v8/test/unittests/BUILD.gn
@@ -86,6 +86,7 @@ v8_source_set("cppgc_unittests_sources") {
   testonly = true
 
   sources = [
+    "heap/cppgc/allocation-unittest.cc",
     "heap/cppgc/compactor-unittest.cc",
     "heap/cppgc/concurrent-marking-unittest.cc",
     "heap/cppgc/concurrent-sweeper-unittest.cc",
@@ -101,6 +102,7 @@ v8_source_set("cppgc_unittests_sources") {
     "heap/cppgc/heap-growing-unittest.cc",
     "heap/cppgc/heap-object-header-unittest.cc",
     "heap/cppgc/heap-page-unittest.cc",
+    "heap/cppgc/heap-registry-unittest.cc",
     "heap/cppgc/heap-statistics-collector-unittest.cc",
     "heap/cppgc/heap-unittest.cc",
     "heap/cppgc/incremental-marking-schedule-unittest.cc",
@@ -117,6 +119,7 @@ v8_source_set("cppgc_unittests_sources") {
     "heap/cppgc/page-memory-unittest.cc",
     "heap/cppgc/persistent-family-unittest.cc",
     "heap/cppgc/prefinalizer-unittest.cc",
+    "heap/cppgc/sanitizer-unittest.cc",
     "heap/cppgc/source-location-unittest.cc",
     "heap/cppgc/stack-unittest.cc",
     "heap/cppgc/stats-collector-scopes-unittest.cc",
@@ -129,6 +132,7 @@ v8_source_set("cppgc_unittests_sources") {
     "heap/cppgc/tests.h",
     "heap/cppgc/visitor-unittest.cc",
     "heap/cppgc/weak-container-unittest.cc",
+    "heap/cppgc/workloads-unittest.cc",
     "heap/cppgc/write-barrier-unittest.cc",
   ]
 
@@ -359,6 +363,7 @@ v8_source_set("unittests_sources") {
     "parser/ast-value-unittest.cc",
     "parser/preparser-unittest.cc",
     "profiler/strings-storage-unittest.cc",
+    "regexp/regexp-unittest.cc",
     "regress/regress-crbug-1041240-unittest.cc",
     "regress/regress-crbug-1056054-unittest.cc",
     "regress/regress-crbug-938251-unittest.cc",
@@ -387,6 +392,10 @@ v8_source_set("unittests_sources") {
     "zone/zone-unittest.cc",
   ]
 
+  if (v8_enable_runtime_call_stats) {
+    sources += [ "logging/runtime-call-stats-unittest.cc" ]
+  }
+
   if (v8_enable_webassembly) {
     sources += [
       "../../test/common/wasm/wasm-macro-gen.h",
diff --git a/chromium/v8/third_party/google_benchmark/BUILD.gn b/chromium/v8/third_party/google_benchmark/BUILD.gn
index 565a39d51c1..e746cc421a0 100644
--- a/chromium/v8/third_party/google_benchmark/BUILD.gn
+++ b/chromium/v8/third_party/google_benchmark/BUILD.gn
@@ -3,8 +3,9 @@
 # found in the LICENSE file.
 
 import("//build/config/gclient_args.gni")
+import("../../gni/v8.gni")
 
-if (checkout_google_benchmark) {
+if (v8_enable_google_benchmark) {
   config("benchmark_config") {
     include_dirs = [ "src/include" ]
   }
@@ -35,11 +36,12 @@ if (checkout_google_benchmark) {
       "src/src/counter.cc",
       "src/src/counter.h",
       "src/src/csv_reporter.cc",
-      "src/src/cycle_clock.h",
       "src/src/internal_macros.h",
       "src/src/json_reporter.cc",
       "src/src/log.h",
       "src/src/mutex.h",
+      "src/src/perf_counters.cc",
+      "src/src/perf_counters.h",
       "src/src/re.h",
       "src/src/reporter.cc",
       "src/src/sleep.cc",
@@ -68,6 +70,6 @@ if (checkout_google_benchmark) {
   source_set("benchmark_main") {
     testonly = true
     sources = [ "src/src/benchmark_main.cc" ]
-    deps = [ ":google_benchmark" ]
+    public_deps = [ ":google_benchmark" ]
   }
 }
diff --git a/chromium/v8/third_party/googletest/BUILD.gn b/chromium/v8/third_party/googletest/BUILD.gn
index cfa9205547d..4d393efd95f 100644
--- a/chromium/v8/third_party/googletest/BUILD.gn
+++ b/chromium/v8/third_party/googletest/BUILD.gn
@@ -2,6 +2,8 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("../../gni/v8.gni")
+
 config("gtest_config") {
   visibility = [ ":*" ]  # gmock also shares this config.
 
@@ -49,8 +51,6 @@ config("gmock_config") {
 source_set("gtest") {
   testonly = true
   sources = [
-    # TODO(crbug.com/829773): Remove this after transitioning off <tr1/tuple>.
-    "custom/gmock/internal/custom/gmock-port.h",
     "src/googletest/include/gtest/gtest-death-test.h",
     "src/googletest/include/gtest/gtest-matchers.h",
     "src/googletest/include/gtest/gtest-message.h",
@@ -64,12 +64,9 @@ source_set("gtest") {
     "src/googletest/include/gtest/internal/gtest-death-test-internal.h",
     "src/googletest/include/gtest/internal/gtest-filepath.h",
     "src/googletest/include/gtest/internal/gtest-internal.h",
-    "src/googletest/include/gtest/internal/gtest-linked_ptr.h",
-    "src/googletest/include/gtest/internal/gtest-param-util-generated.h",
     "src/googletest/include/gtest/internal/gtest-param-util.h",
     "src/googletest/include/gtest/internal/gtest-port.h",
     "src/googletest/include/gtest/internal/gtest-string.h",
-    "src/googletest/include/gtest/internal/gtest-tuple.h",
     "src/googletest/include/gtest/internal/gtest-type-util.h",
 
     #"src/googletest/src/gtest-all.cc",  # Not needed by our build.
@@ -92,6 +89,15 @@ source_set("gtest") {
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]
 
+  # V8-only workaround for http://crbug.com/chromium/1191946. Ensures that
+  # googletest is compiled with the same visibility such as the rest of V8, see
+  # https://source.chromium.org/chromium/chromium/src/+/master:v8/gni/v8.gni
+  if ((is_posix || is_fuchsia) &&
+      (v8_enable_backtrace || v8_monolithic || v8_expose_symbols)) {
+    configs -= [ "//build/config/gcc:symbol_visibility_hidden" ]
+    configs += [ "//build/config/gcc:symbol_visibility_default" ]
+  }
+
   deps = []
 
   if (is_fuchsia) {
@@ -118,22 +124,16 @@ source_set("gmock") {
     "src/googlemock/include/gmock/gmock-actions.h",
     "src/googlemock/include/gmock/gmock-cardinalities.h",
     "src/googlemock/include/gmock/gmock-function-mocker.h",
-    "src/googlemock/include/gmock/gmock-generated-actions.h",
-    "src/googlemock/include/gmock/gmock-generated-nice-strict.h",
     "src/googlemock/include/gmock/gmock-matchers.h",
     "src/googlemock/include/gmock/gmock-more-actions.h",
     "src/googlemock/include/gmock/gmock-more-matchers.h",
     "src/googlemock/include/gmock/gmock-nice-strict.h",
     "src/googlemock/include/gmock/gmock-spec-builders.h",
     "src/googlemock/include/gmock/gmock.h",
-    "src/googlemock/include/gmock/internal/gmock-generated-internal-utils.h",
     "src/googlemock/include/gmock/internal/gmock-internal-utils.h",
     "src/googlemock/include/gmock/internal/gmock-port.h",
     "src/googlemock/include/gmock/internal/gmock-pp.h",
 
-    # gmock helpers.
-    "custom/gmock/internal/custom/gmock-port.h",
-
     #"src/googlemock/src/gmock-all.cc",  # Not needed by our build.
     "src/googlemock/src/gmock-cardinalities.cc",
     "src/googlemock/src/gmock-internal-utils.cc",
@@ -142,10 +142,21 @@ source_set("gmock") {
     "src/googlemock/src/gmock.cc",
   ]
 
+  # V8-only workaround for http://crbug.com/chromium/1191946. Ensures that
+  # googletest is compiled with the same visibility such as the rest of V8, see
+  # https://source.chromium.org/chromium/chromium/src/+/master:v8/gni/v8.gni
+  if ((is_posix || is_fuchsia) &&
+      (v8_enable_backtrace || v8_monolithic || v8_expose_symbols)) {
+    configs -= [ "//build/config/gcc:symbol_visibility_hidden" ]
+    configs += [ "//build/config/gcc:symbol_visibility_default" ]
+  }
+
   public_configs = [
     ":gmock_config",
     ":gtest_config",
   ]
+
+  deps = [ ":gtest" ]
 }
 
 # Do NOT depend on this directly. Use //testing/gmock:gmock_main instead.
@@ -153,5 +164,8 @@ source_set("gmock") {
 static_library("gmock_main") {
   testonly = true
   sources = [ "src/googlemock/src/gmock_main.cc" ]
-  deps = [ ":gmock" ]
+  deps = [
+    ":gmock",
+    ":gtest",
+  ]
 }
diff --git a/chromium/v8/third_party/inspector_protocol/BUILD.gn b/chromium/v8/third_party/inspector_protocol/BUILD.gn
index 880b651c095..94b7fe2677a 100644
--- a/chromium/v8/third_party/inspector_protocol/BUILD.gn
+++ b/chromium/v8/third_party/inspector_protocol/BUILD.gn
@@ -5,7 +5,10 @@
 import("../../gni/v8.gni")
 
 config("crdtp_config") {
-  visibility = [ "../../src/inspector:*", ":*" ]
+  visibility = [
+    ":*",
+    "../../src/inspector:*",
+  ]
   configs = [ "../../:internal_config" ]
   include_dirs = [ "../../include" ]
 }
@@ -46,6 +49,7 @@ v8_source_set("crdtp_platform") {
     "crdtp/json_platform_v8.cc",
   ]
   public_deps = [ "../..:v8_libbase" ]
+  deps = [ "../../:v8_internal_headers" ]
   configs = [ ":crdtp_config" ]
 }
 
diff --git a/chromium/v8/third_party/inspector_protocol/README.v8 b/chromium/v8/third_party/inspector_protocol/README.v8
index 97bc1c34147..cc5e083c6a2 100644
--- a/chromium/v8/third_party/inspector_protocol/README.v8
+++ b/chromium/v8/third_party/inspector_protocol/README.v8
@@ -2,7 +2,7 @@ Name: inspector protocol
 Short Name: inspector_protocol
 URL: https://chromium.googlesource.com/deps/inspector_protocol/
 Version: 0
-Revision: 94298cef795ec994106bdaff002c41182911b767
+Revision: 35e8d2d89cb017d72cf905362672de77c978e1e6
 License: BSD
 License File: LICENSE
 Security Critical: no
diff --git a/chromium/v8/third_party/inspector_protocol/crdtp/serializable.cc b/chromium/v8/third_party/inspector_protocol/crdtp/serializable.cc
index 20de53ecc08..7a21ffd35fe 100644
--- a/chromium/v8/third_party/inspector_protocol/crdtp/serializable.cc
+++ b/chromium/v8/third_party/inspector_protocol/crdtp/serializable.cc
@@ -4,6 +4,8 @@
 
 #include "serializable.h"
 
+#include <utility>
+
 namespace v8_crdtp {
 // =============================================================================
 // Serializable - An object to be emitted as a sequence of bytes.
@@ -18,7 +20,8 @@ std::vector<uint8_t> Serializable::Serialize() const {
 namespace {
 class PreSerialized : public Serializable {
  public:
-  explicit PreSerialized(std::vector<uint8_t> bytes) : bytes_(bytes) {}
+  explicit PreSerialized(std::vector<uint8_t> bytes)
+      : bytes_(std::move(bytes)) {}
 
   void AppendSerialized(std::vector<uint8_t>* out) const override {
     out->insert(out->end(), bytes_.begin(), bytes_.end());
diff --git a/chromium/v8/third_party/inspector_protocol/crdtp/status.cc b/chromium/v8/third_party/inspector_protocol/crdtp/status.cc
index 4a8e03d3898..7181df97d16 100644
--- a/chromium/v8/third_party/inspector_protocol/crdtp/status.cc
+++ b/chromium/v8/third_party/inspector_protocol/crdtp/status.cc
@@ -113,6 +113,8 @@ std::string Status::Message() const {
       return "BINDINGS: string8 value expected";
     case Error::BINDINGS_BINARY_VALUE_EXPECTED:
       return "BINDINGS: binary value expected";
+    case Error::BINDINGS_DICTIONARY_VALUE_EXPECTED:
+      return "BINDINGS: dictionary value expected";
   }
   // Some compilers can't figure out that we can't get here.
   return "INVALID ERROR CODE";
diff --git a/chromium/v8/third_party/inspector_protocol/crdtp/status.h b/chromium/v8/third_party/inspector_protocol/crdtp/status.h
index 45e0a57acfb..1039156942c 100644
--- a/chromium/v8/third_party/inspector_protocol/crdtp/status.h
+++ b/chromium/v8/third_party/inspector_protocol/crdtp/status.h
@@ -77,6 +77,7 @@ enum class Error {
   BINDINGS_STRING_VALUE_EXPECTED = 0x34,
   BINDINGS_STRING8_VALUE_EXPECTED = 0x35,
   BINDINGS_BINARY_VALUE_EXPECTED = 0x36,
+  BINDINGS_DICTIONARY_VALUE_EXPECTED = 0x37,
 };
 
 // A status value with position that can be copied. The default status
diff --git a/chromium/v8/third_party/inspector_protocol/lib/ValueConversions_cpp.template b/chromium/v8/third_party/inspector_protocol/lib/ValueConversions_cpp.template
index 36c8dcc3563..a16b522c38a 100644
--- a/chromium/v8/third_party/inspector_protocol/lib/ValueConversions_cpp.template
+++ b/chromium/v8/third_party/inspector_protocol/lib/ValueConversions_cpp.template
@@ -96,6 +96,10 @@ bool ProtocolTypeTraits<std::unique_ptr<DictionaryValue>>::Deserialize(
   std::unique_ptr<Value> res;
   if (!ProtocolTypeTraits<std::unique_ptr<Value>>::Deserialize(state, &res))
     return false;
+  if (res->type() != Value::TypeObject) {
+    state->RegisterError(Error::BINDINGS_DICTIONARY_VALUE_EXPECTED);
+    return false;
+  }
   *value = DictionaryValue::cast(std::move(res));
   return true;
 }
diff --git a/chromium/v8/third_party/inspector_protocol/lib/base_string_adapter_cc.template b/chromium/v8/third_party/inspector_protocol/lib/base_string_adapter_cc.template
index e503f5c23e2..10488f22432 100644
--- a/chromium/v8/third_party/inspector_protocol/lib/base_string_adapter_cc.template
+++ b/chromium/v8/third_party/inspector_protocol/lib/base_string_adapter_cc.template
@@ -11,7 +11,6 @@
 #include "base/base64.h"
 #include "base/json/json_reader.h"
 #include "base/memory/ptr_util.h"
-#include "base/strings/string16.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
@@ -141,7 +140,7 @@ std::unique_ptr<base::Value> toBaseValue(Value* value, int depth) {
 // static
 String StringUtil::fromUTF16LE(const uint16_t* data, size_t length) {
   std::string utf8;
-  base::UTF16ToUTF8(reinterpret_cast<const base::char16*>(data), length, &utf8);
+  base::UTF16ToUTF8(reinterpret_cast<const char16_t*>(data), length, &utf8);
   return utf8;
 }
 
@@ -246,4 +245,4 @@ void ProtocolTypeTraits<Binary>::Serialize(const Binary& value, std::vector<uint
   value.AppendSerialized(bytes);
 }
 
-}  // namespace {{config.crdtp.namespace}}
\ No newline at end of file
+}  // namespace {{config.crdtp.namespace}}
diff --git a/chromium/v8/third_party/inspector_protocol/pdl.py b/chromium/v8/third_party/inspector_protocol/pdl.py
index d7733634e58..9a9fec98988 100644
--- a/chromium/v8/third_party/inspector_protocol/pdl.py
+++ b/chromium/v8/third_party/inspector_protocol/pdl.py
@@ -27,6 +27,9 @@ def assignType(item, type, is_array=False, map_binary_to_string=False):
     type = 'string'
   if map_binary_to_string and type == 'binary':
     type = 'string'
+    if 'description' in item:
+      item['description'] = (item['description'] +
+          ' (Encoded as a base64 string when passed over JSON)')
   if type in primitiveTypes:
     item['type'] = type
   else:
diff --git a/chromium/v8/third_party/jsoncpp/BUILD.gn b/chromium/v8/third_party/jsoncpp/BUILD.gn
index 411d2d62e73..6324be019c4 100644
--- a/chromium/v8/third_party/jsoncpp/BUILD.gn
+++ b/chromium/v8/third_party/jsoncpp/BUILD.gn
@@ -21,9 +21,7 @@ source_set("jsoncpp") {
   sources = [
     "generated/version.h",
     "source/include/json/assertions.h",
-    "source/include/json/autolink.h",
     "source/include/json/config.h",
-    "source/include/json/features.h",
     "source/include/json/forwards.h",
     "source/include/json/json.h",
     "source/include/json/reader.h",
diff --git a/chromium/v8/tools/clusterfuzz/v8_foozzie.py b/chromium/v8/tools/clusterfuzz/v8_foozzie.py
index 9f3810c9f5b..52b79540939 100755
--- a/chromium/v8/tools/clusterfuzz/v8_foozzie.py
+++ b/chromium/v8/tools/clusterfuzz/v8_foozzie.py
@@ -211,14 +211,14 @@ class ExecutionArgumentsConfig(object):
         'default: bundled in the directory of this script',
         default=DEFAULT_D8)
 
-  def make_options(self, options, default_config=None):
+  def make_options(self, options, default_config=None, default_d8=None):
     def get(name):
       return getattr(options, '%s_%s' % (self.label, name))
 
     config = default_config or get('config')
     assert config in CONFIGS
 
-    d8 = get('d8')
+    d8 = default_d8 or get('d8')
     if not os.path.isabs(d8):
       d8 = os.path.join(BASE_PATH, d8)
     assert os.path.exists(d8)
@@ -239,6 +239,13 @@ class ExecutionConfig(object):
     flags = getattr(options, label).flags
     self.command = Command(options, label, d8, flags)
 
+    # Options for a fallback configuration only exist when comparing
+    # different architectures.
+    fallback_label = label + '_fallback'
+    self.fallback = None
+    if getattr(options, fallback_label, None):
+      self.fallback = ExecutionConfig(options, fallback_label)
+
   @property
   def flags(self):
     return self.command.flags
@@ -278,7 +285,15 @@ def parse_args():
   options.first = first_config_arguments.make_options(options)
   options.second = second_config_arguments.make_options(options)
   options.default = second_config_arguments.make_options(
-      options, DEFAULT_CONFIG)
+      options, default_config=DEFAULT_CONFIG)
+
+  # Use fallback configurations only on diffrent architectures. In this
+  # case we are going to re-test against the first architecture.
+  if options.first.arch != options.second.arch:
+    options.second_fallback = second_config_arguments.make_options(
+        options, default_d8=options.first.d8)
+    options.default_fallback = second_config_arguments.make_options(
+        options, default_config=DEFAULT_CONFIG, default_d8=options.first.d8)
 
   # Ensure we make a valid comparison.
   if (options.first.d8 == options.second.d8 and
@@ -315,10 +330,12 @@ def fail_bailout(output, ignore_by_output_fun):
 
 
 def format_difference(
-    source_key, first_config, second_config,
-    first_config_output, second_config_output, difference, source=None):
+    first_config, second_config,
+    first_config_output, second_config_output,
+    difference, source_key=None, source=None):
   # The first three entries will be parsed by clusterfuzz. Format changes
   # will require changes on the clusterfuzz side.
+  source_key = source_key or cluster_failures(source)
   first_config_label = '%s,%s' % (first_config.arch, first_config.config)
   second_config_label = '%s,%s' % (second_config.arch, second_config.config)
   source_file_text = SOURCE_FILE_TEMPLATE % source if source else ''
@@ -376,6 +393,29 @@ def cluster_failures(source, known_failures=None):
   return long_key[:ORIGINAL_SOURCE_HASH_LENGTH]
 
 
+class RepeatedRuns(object):
+  """Helper class for storing statistical data from repeated runs."""
+  def __init__(self, test_case, timeout, verbose):
+    self.test_case = test_case
+    self.timeout = timeout
+    self.verbose = verbose
+
+    # Stores if any run has crashed or was simulated.
+    self.has_crashed = False
+    self.simulated = False
+
+  def run(self, config):
+    comparison_output = config.command.run(
+        self.test_case, timeout=self.timeout, verbose=self.verbose)
+    self.has_crashed = self.has_crashed or comparison_output.HasCrashed()
+    self.simulated = self.simulated or config.is_error_simulation
+    return comparison_output
+
+  @property
+  def crash_state(self):
+    return '_simulated_crash_' if self.simulated else '_unexpected_crash_'
+
+
 def run_comparisons(suppress, execution_configs, test_case, timeout,
                     verbose=True, ignore_crashes=True, source_key=None):
   """Runs different configurations and bails out on output difference.
@@ -393,20 +433,15 @@ def run_comparisons(suppress, execution_configs, test_case, timeout,
     source_key: A fixed source key. If not given, it will be inferred from the
         output.
   """
-  run_test_case = lambda config: config.command.run(
-      test_case, timeout=timeout, verbose=verbose)
+  runner = RepeatedRuns(test_case, timeout, verbose)
 
   # Run the baseline configuration.
   baseline_config = execution_configs[0]
-  baseline_output = run_test_case(baseline_config)
-  has_crashed = baseline_output.HasCrashed()
-  simulated = baseline_config.is_error_simulation
+  baseline_output = runner.run(baseline_config)
 
   # Iterate over the remaining configurations, run and compare.
   for comparison_config in execution_configs[1:]:
-    comparison_output = run_test_case(comparison_config)
-    has_crashed = has_crashed or comparison_output.HasCrashed()
-    simulated = simulated or comparison_config.is_error_simulation
+    comparison_output = runner.run(comparison_config)
     difference, source = suppress.diff(baseline_output, comparison_output)
 
     if difference:
@@ -416,12 +451,25 @@ def run_comparisons(suppress, execution_configs, test_case, timeout,
       fail_bailout(baseline_output, suppress.ignore_by_output)
       fail_bailout(comparison_output, suppress.ignore_by_output)
 
-      source_key = source_key or cluster_failures(source)
+      # Check if a difference also occurs with the fallback configuration and
+      # give it precedence. E.g. we always prefer x64 differences.
+      if comparison_config.fallback:
+        fallback_output = runner.run(comparison_config.fallback)
+        fallback_difference, fallback_source = suppress.diff(
+            baseline_output, fallback_output)
+        if fallback_difference:
+          fail_bailout(fallback_output, suppress.ignore_by_output)
+          source = fallback_source
+          comparison_config = comparison_config.fallback
+          comparison_output = fallback_output
+          difference = fallback_difference
+
       raise FailException(format_difference(
-          source_key, baseline_config, comparison_config,
-          baseline_output, comparison_output, difference, source))
+          baseline_config, comparison_config,
+          baseline_output, comparison_output,
+          difference, source_key, source))
 
-  if has_crashed:
+  if runner.has_crashed:
     if ignore_crashes:
       # Show if a crash has happened in one of the runs and no difference was
       # detected. This is only for the statistics during experiments.
@@ -429,9 +477,8 @@ def run_comparisons(suppress, execution_configs, test_case, timeout,
     else:
       # Subsume simulated and unexpected crashes (e.g. during smoke tests)
       # with one failure state.
-      crash_state = '_simulated_crash_' if simulated else '_unexpected_crash_'
       raise FailException(FAILURE_HEADER_TEMPLATE % dict(
-          configs='', source_key='', suppression=crash_state))
+          configs='', source_key='', suppression=runner.crash_state))
 
 
 def main():
@@ -448,7 +495,7 @@ def main():
   content_bailout(content, suppress.ignore_by_content)
 
   # Prepare the baseline, default and a secondary configuration to compare to.
-  # The baseline (turbofan) takes precedence as many of the secondary configs
+  # The default (turbofan) takes precedence as many of the secondary configs
   # are based on the turbofan config with additional parameters.
   execution_configs = [
     ExecutionConfig(options, 'first'),
diff --git a/chromium/v8/tools/clusterfuzz/v8_foozzie_test.py b/chromium/v8/tools/clusterfuzz/v8_foozzie_test.py
index eb8322ce622..a8ba74364bc 100755
--- a/chromium/v8/tools/clusterfuzz/v8_foozzie_test.py
+++ b/chromium/v8/tools/clusterfuzz/v8_foozzie_test.py
@@ -263,7 +263,7 @@ class SystemTest(unittest.TestCase):
 
   Overview of fakes:
     baseline: Example foozzie output including a syntax error.
-    build1: Difference to baseline is a stack trace differece expected to
+    build1: Difference to baseline is a stack trace difference expected to
             be suppressed.
     build2: Difference to baseline is a non-suppressed output difference
             causing the script to fail.
@@ -312,6 +312,36 @@ class SystemTest(unittest.TestCase):
     self.assertIn('v8_mock_archs.js', lines[1])
     self.assertIn('v8_mock_archs.js', lines[3])
 
+  def testDifferentArchFailFirst(self):
+    """Test that we re-test against x64. This tests the path that also fails
+    on x64 and then reports the error as x64.
+    """
+    with open(os.path.join(TEST_DATA, 'failure_output_arch.txt')) as f:
+      expected_output = f.read()
+    # Build 3 simulates x86 and produces a difference on --bad-flag, but
+    # the baseline build shows the same difference when --bad-flag is passed.
+    with self.assertRaises(subprocess.CalledProcessError) as ctx:
+      run_foozzie('build3', '--skip-smoke-tests',
+                  '--second-config-extra-flags=--bad-flag')
+    e = ctx.exception
+    self.assertEqual(v8_foozzie.RETURN_FAIL, e.returncode)
+    self.assertEqual(expected_output, cut_verbose_output(e.output, 3))
+
+  def testDifferentArchFailSecond(self):
+    """As above, but we test the path that only fails in the second (ia32)
+    run and not with x64 and then reports the error as ia32.
+    """
+    with open(os.path.join(TEST_DATA, 'failure_output_second.txt')) as f:
+      expected_output = f.read()
+    # Build 3 simulates x86 and produces a difference on --very-bad-flag,
+    # which the baseline build doesn't.
+    with self.assertRaises(subprocess.CalledProcessError) as ctx:
+      run_foozzie('build3', '--skip-smoke-tests',
+                  '--second-config-extra-flags=--very-bad-flag')
+    e = ctx.exception
+    self.assertEqual(v8_foozzie.RETURN_FAIL, e.returncode)
+    self.assertEqual(expected_output, cut_verbose_output(e.output, 3))
+
   def testJitless(self):
     """Test that webassembly is mocked out when comparing with jitless."""
     stdout = run_foozzie(
diff --git a/chromium/v8/tools/clusterfuzz/v8_mock.js b/chromium/v8/tools/clusterfuzz/v8_mock.js
index be7a40b70f4..41f1901d5d6 100644
--- a/chromium/v8/tools/clusterfuzz/v8_mock.js
+++ b/chromium/v8/tools/clusterfuzz/v8_mock.js
@@ -99,7 +99,11 @@ Object.defineProperty(
 
 // Mock buffer access in float typed arrays because of varying NaN patterns.
 (function() {
+  const origArrayFrom = Array.from;
+  const origArrayIsArray = Array.isArray;
+  const origFunctionPrototype = Function.prototype;
   const origIsNaN = isNaN;
+  const origIterator = Symbol.iterator;
   const deNaNify = function(value) { return origIsNaN(value) ? 1 : value; };
   const mock = function(type) {
 
@@ -117,17 +121,17 @@ Object.defineProperty(
       construct: function(target, args) {
         for (let i = 0; i < args.length; i++) {
           if (args[i] != null &&
-              typeof args[i][Symbol.iterator] === 'function') {
+              typeof args[i][origIterator] === 'function') {
             // Consume iterators.
-            args[i] = Array.from(args[i]);
+            args[i] = origArrayFrom(args[i]);
           }
-          if (Array.isArray(args[i])) {
+          if (origArrayIsArray(args[i])) {
             args[i] = args[i].map(deNaNify);
           }
         }
 
         const obj = new (
-            Function.prototype.bind.call(type, null, ...args));
+            origFunctionPrototype.bind.call(type, null, ...args));
         return new Proxy(obj, {
           get: function(x, prop) {
             if (typeof x[prop] == "function")
diff --git a/chromium/v8/tools/codemap.mjs b/chromium/v8/tools/codemap.mjs
index 4986fbd3b05..5beeb3b1b6f 100644
--- a/chromium/v8/tools/codemap.mjs
+++ b/chromium/v8/tools/codemap.mjs
@@ -252,11 +252,18 @@ export class CodeMap {
   }
 
   /**
-   * Returns an array of all libraries entries.
+   * Returns an array of all library entries.
    */
-  getAllLibrariesEntries() {
+  getAllLibraryEntries() {
     return this.libraries_.exportValues();
   }
+
+  /**
+   * Returns an array of pairs of all library entries and their addresses.
+   */
+  getAllLibraryEntriesWithAddresses() {
+    return this.libraries_.exportKeysAndValues();
+  }
 }
 
 
diff --git a/chromium/v8/tools/cppgc/gen_cmake.py b/chromium/v8/tools/cppgc/gen_cmake.py
index 6fc1bc0b030..90eda1f3bb1 100755
--- a/chromium/v8/tools/cppgc/gen_cmake.py
+++ b/chromium/v8/tools/cppgc/gen_cmake.py
@@ -244,6 +244,7 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 option(CPPGC_ENABLE_OBJECT_NAMES "Enable object names in cppgc for debug purposes" OFF)
 option(CPPGC_ENABLE_CAGED_HEAP "Enable heap reservation of size 4GB, only possible for 64bit archs" OFF)
+option(CPPGC_ENABLE_VERIFY_LIVE_BYTES " Enable verification of live bytes in the marking verifier" OFF)
 option(CPPGC_ENABLE_YOUNG_GENERATION "Enable young generation in cppgc" OFF)
 set(CPPGC_TARGET_ARCH "x64" CACHE STRING "Target architecture, possible options: x64, x86, arm, arm64, ppc64, s390x, mipsel, mips64el")
 
@@ -433,6 +434,9 @@ endif()
 if(CPPGC_ENABLE_CAGED_HEAP)
   target_compile_definitions({target.name} PRIVATE "-DCPPGC_CAGED_HEAP")
 endif()
+if(CPPGC_ENABLE_VERIFY_LIVE_BYTES)
+  target_compile_definitions({target.name} PRIVATE "-DCPPGC_VERIFY_LIVE_BYTES")
+endif()
 if(CPPGC_ENABLE_YOUNG_GENERATION)
   target_compile_definitions({target.name} PRIVATE "-DCPPGC_YOUNG_GENERATION")
 endif()"""
diff --git a/chromium/v8/tools/debug_helper/get-object-properties.cc b/chromium/v8/tools/debug_helper/get-object-properties.cc
index 7199bc51d22..b85bbc05906 100644
--- a/chromium/v8/tools/debug_helper/get-object-properties.cc
+++ b/chromium/v8/tools/debug_helper/get-object-properties.cc
@@ -316,7 +316,10 @@ class ReadStringVisitor : public TqObjectVisitor {
   bool IsExternalStringCached(const TqExternalString* object) {
     // The safest way to get the instance type is to use known map pointers, in
     // case the map data is not available.
-    uintptr_t map = GetOrFinish(object->GetMapValue(accessor_));
+    Value<uintptr_t> map_ptr = object->GetMapValue(accessor_);
+    DCHECK_IMPLIES(map_ptr.validity == d::MemoryAccessResult::kOk,
+                   !v8::internal::MapWord::IsPacked(map_ptr.value));
+    uintptr_t map = GetOrFinish(map_ptr);
     if (done_) return false;
     auto instance_types = FindKnownMapInstanceTypes(map, heap_addresses_);
     // Exactly one of the matched instance types should be a string type,
@@ -347,10 +350,10 @@ class ReadStringVisitor : public TqObjectVisitor {
       ExternalPointer_t resource_data =
           GetOrFinish(object->GetResourceDataValue(accessor_));
 #ifdef V8_COMPRESS_POINTERS
-      uintptr_t data_address = static_cast<uintptr_t>(
-          DecodeExternalPointer(GetPtrComprCageBaseFromOnHeapAddress(
-                                    heap_addresses_.any_heap_pointer),
-                                resource_data, kExternalStringResourceDataTag));
+      Isolate* isolate = GetIsolateForHeapSandbox(
+          HeapObject::unchecked_cast(Object(heap_addresses_.any_heap_pointer)));
+      uintptr_t data_address = static_cast<uintptr_t>(DecodeExternalPointer(
+          isolate, resource_data, kExternalStringResourceDataTag));
 #else
       uintptr_t data_address = static_cast<uintptr_t>(resource_data);
 #endif  // V8_COMPRESS_POINTERS
@@ -500,6 +503,7 @@ class AddInfoVisitor : public TqObjectVisitor {
     if (map_ptr.validity != d::MemoryAccessResult::kOk) {
       return;  // Can't read the JSObject. Nothing useful to do.
     }
+    DCHECK(!v8::internal::MapWord::IsPacked(map_ptr.value));
     TqMap map(map_ptr.value);
 
     // On JSObject instances, this value is the start of in-object properties.
diff --git a/chromium/v8/tools/dev/gm.py b/chromium/v8/tools/dev/gm.py
index 4e318f2f32e..8a05da3cc96 100755
--- a/chromium/v8/tools/dev/gm.py
+++ b/chromium/v8/tools/dev/gm.py
@@ -262,10 +262,10 @@ class Config(object):
       cpu = "arm"
     elif self.arch == "android_arm64":
       cpu = "arm64"
-    elif self.arch == "arm64" and _GetMachine() == "aarch64":
+    elif self.arch == "arm64" and _GetMachine() in ("aarch64", "arm64"):
       # arm64 build host:
       cpu = "arm64"
-    elif self.arch == "arm" and _GetMachine() == "aarch64":
+    elif self.arch == "arm" and _GetMachine() in ("aarch64", "arm64"):
       cpu = "arm"
     elif "64" in self.arch or self.arch == "s390x":
       # Native x64 or simulator build.
@@ -291,7 +291,8 @@ class Config(object):
 
   def GetSpecialCompiler(self):
     if _GetMachine() == "aarch64":
-      # We have no prebuilt Clang for arm64. Use the system Clang instead.
+      # We have no prebuilt Clang for arm64 on Linux, so use the system Clang
+      # instead.
       return ["clang_base_path = \"/usr\"", "clang_use_chrome_plugins = false"]
     return []
 
diff --git a/chromium/v8/tools/dev/v8gen.py b/chromium/v8/tools/dev/v8gen.py
index 18abf8aa25f..c6ba1d2174a 100755
--- a/chromium/v8/tools/dev/v8gen.py
+++ b/chromium/v8/tools/dev/v8gen.py
@@ -121,7 +121,7 @@ class GenerateGnArgs(object):
     add_common_options(list_cmd)
 
     # Default to "gen" unless global help is requested.
-    if not args or args[0] not in subps.choices.keys() + ['-h', '--help']:
+    if not args or args[0] not in list(subps.choices) + ['-h', '--help']:
       args = ['gen'] + args
 
     return self.parser.parse_args(args)
@@ -193,14 +193,16 @@ class GenerateGnArgs(object):
     return 0
 
   def verbose_print_1(self, text):
-    if self._options.verbosity >= 1:
+    if self._options.verbosity and self._options.verbosity >= 1:
       print('#' * 80)
       print(text)
 
   def verbose_print_2(self, text):
-    if self._options.verbosity >= 2:
+    if self._options.verbosity and self._options.verbosity >= 2:
       indent = ' ' * 2
       for l in text.splitlines():
+        if type(l) == bytes:
+          l = l.decode()
         print(indent + l)
 
   def _call_cmd(self, args):
@@ -306,7 +308,7 @@ if __name__ == "__main__":
   try:
     sys.exit(gen.main())
   except Exception:
-    if gen._options.verbosity < 2:
+    if not gen._options.verbosity or gen._options.verbosity < 2:
       print ('\nHint: You can raise verbosity (-vv) to see the output of '
              'failed commands.\n')
     raise
diff --git a/chromium/v8/tools/generate-header-include-checks.py b/chromium/v8/tools/generate-header-include-checks.py
index 4e58a492dec..2171ee8a0da 100755
--- a/chromium/v8/tools/generate-header-include-checks.py
+++ b/chromium/v8/tools/generate-header-include-checks.py
@@ -31,6 +31,8 @@ OUT_DIR = os.path.join(V8_DIR, 'check-header-includes')
 AUTO_EXCLUDE = [
   # flag-definitions.h needs a mode set for being included.
   'src/flags/flag-definitions.h',
+  # recorder.h should only be included conditionally.
+  'src/libplatform/tracing/recorder.h',
 ]
 AUTO_EXCLUDE_PATTERNS = [
   'src/base/atomicops_internals_.*',
diff --git a/chromium/v8/tools/mb/mb.py b/chromium/v8/tools/mb/mb.py
index 8ca90899440..7031ba50dbd 100755
--- a/chromium/v8/tools/mb/mb.py
+++ b/chromium/v8/tools/mb/mb.py
@@ -27,7 +27,16 @@ import sys
 import subprocess
 import tempfile
 import traceback
-import urllib2
+
+# for py2/py3 compatibility
+try:
+  from urllib.parse import quote
+except ImportError:
+  from urllib2 import quote
+try:
+  from urllib.request import urlopen
+except ImportError:
+  from urllib2 import urlopen
 
 from collections import OrderedDict
 
@@ -869,7 +878,7 @@ class MetaBuildWrapper(object):
     return err, labels
 
   def GNCmd(self, subcommand, path, *args):
-    if self.platform == 'linux2':
+    if self.platform.startswith('linux'):
       subdir, exe = 'linux64', 'gn'
     elif self.platform == 'darwin':
       subdir, exe = 'mac', 'gn'
@@ -1109,7 +1118,7 @@ class MetaBuildWrapper(object):
 
   def CheckCompile(self, builder_group, builder):
     url_template = self.args.url_template + '/{builder}/builds/_all?as_text=1'
-    url = urllib2.quote(
+    url = quote(
             url_template.format(builder_group=builder_group, builder=builder),
             safe=':/()?=')
     try:
@@ -1201,7 +1210,7 @@ class MetaBuildWrapper(object):
 
   def Fetch(self, url):
     # This function largely exists so it can be overridden for testing.
-    f = urllib2.urlopen(url)
+    f = urlopen(url)
     contents = f.read()
     f.close()
     return contents
diff --git a/chromium/v8/tools/profile.mjs b/chromium/v8/tools/profile.mjs
index f4be41e2da3..8001f4b5aeb 100644
--- a/chromium/v8/tools/profile.mjs
+++ b/chromium/v8/tools/profile.mjs
@@ -151,6 +151,14 @@ export class Profile {
   scripts_ = [];
   urlToScript_ = new Map();
 
+  serializeVMSymbols() {
+    let result = this.codeMap_.getAllStaticEntriesWithAddresses();
+    result.concat(this.codeMap_.getAllLibraryEntriesWithAddresses())
+    return result.map(([startAddress, codeEntry]) => {
+      return [codeEntry.getName(), startAddress, startAddress + codeEntry.size]
+    });
+  }
+
   /**
    * Returns whether a function with the specified name must be skipped.
    * Should be overriden by subclasses.
@@ -182,7 +190,6 @@ export class Profile {
     COMPILED: 0,
     IGNITION: 1,
     BASELINE: 2,
-    NATIVE_CONTEXT_INDEPENDENT: 3,
     TURBOPROP: 4,
     TURBOFAN: 5,
   }
@@ -198,8 +205,6 @@ export class Profile {
         return this.CodeState.IGNITION;
       case '^':
         return this.CodeState.BASELINE;
-      case '-':
-        return this.CodeState.NATIVE_CONTEXT_INDEPENDENT;
       case '+':
         return this.CodeState.TURBOPROP;
       case '*':
@@ -215,8 +220,6 @@ export class Profile {
       return "Unopt";
     } else if (state === this.CodeState.BASELINE) {
       return "Baseline";
-    } else if (state === this.CodeState.NATIVE_CONTEXT_INDEPENDENT) {
-      return "NCI";
     } else if (state === this.CodeState.TURBOPROP) {
       return "Turboprop";
     } else if (state === this.CodeState.TURBOFAN) {
diff --git a/chromium/v8/tools/profview/profile-utils.js b/chromium/v8/tools/profview/profile-utils.js
index 35fe3d7cb25..bd9f248b54d 100644
--- a/chromium/v8/tools/profview/profile-utils.js
+++ b/chromium/v8/tools/profview/profile-utils.js
@@ -6,11 +6,12 @@
 
 let codeKinds = [
     "UNKNOWN",
-    "CPPPARSE",
-    "CPPCOMPBC",
-    "CPPCOMP",
-    "CPPGC",
-    "CPPEXT",
+    "CPP_PARSE",
+    "CPP_COMP_BC",
+    "CPP_COMP_BASELINE",
+    "CPP_COMP",
+    "CPP_GC",
+    "CPP_EXT",
     "CPP",
     "LIB",
     "IC",
@@ -18,11 +19,10 @@ let codeKinds = [
     "STUB",
     "BUILTIN",
     "REGEXP",
-    "JSOPT",
-    "JSUNOPT",
-    "JSNCI",
-    "JSTURBOPROP",
-    "JSBASELINE",
+    "JS_OPT",
+    "JS_UNOPT",
+    "JS_TURBOPROP",
+    "JS_BASELINE",
 ];
 
 function resolveCodeKind(code) {
@@ -53,17 +53,15 @@ function resolveCodeKind(code) {
     return "CODE";
   } else if (code.type === "JS") {
     if (code.kind === "Builtin") {
-      return "JSUNOPT";
+      return "JS_UNOPT";
     } else if (code.kind === "Opt") {
-      return "JSOPT";
+      return "JS_OPT";
     } else if (code.kind === "Unopt") {
-      return "JSUNOPT";
-    } else if (code.kind === "NCI") {
-      return "JSNCI";
+      return "JS_UNOPT";
     } else if (code.kind === "Baseline") {
-      return "JSBASELINE";
+      return "JS_BASELINE";
     } else if (code.kind === "Turboprop") {
-      return "JSTURBOPROP";
+      return "JS_TURBOPROP";
     }
   }
   console.log("Unknown code type '" + type + "'.");
@@ -73,16 +71,17 @@ function resolveCodeKindAndVmState(code, vmState) {
   let kind = resolveCodeKind(code);
   if (kind === "CPP") {
     if (vmState === 1) {
-      kind = "CPPGC";
+      kind = "CPP_GC";
     } else if (vmState === 2) {
-      kind = "CPPPARSE";
+      kind = "CPP_PARSE";
     } else if (vmState === 3) {
-      kind = "CPPCOMPBC";
+      kind = "CPP_COMP_BC";
     } else if (vmState === 4) {
-      kind = "CPPCOMP";
+      kind = "CPP_COMP";
     } else if (vmState === 6) {
-      kind = "CPPEXT";
+      kind = "CPP_EXT";
     }
+    // TODO(cbruni): add CPP_COMP_BASELINE
   }
   return kind;
 }
@@ -272,20 +271,20 @@ function buildCategoryTreeAndLookup() {
     }
     root.children.push(n);
   }
-  addCategory("JS Optimized", [ "JSOPT" ]);
-  addCategory("JS NCI", [ "JSNCI" ]);
-  addCategory("JS Turboprop", [ "JSTURBOPROP" ]);
-  addCategory("JS Baseline", [ "JSBASELINE" ]);
-  addCategory("JS Unoptimized", [ "JSUNOPT", "BC" ]);
+  addCategory("JS Optimized", [ "JS_OPT" ]);
+  addCategory("JS Turboprop", [ "JS_TURBOPROP" ]);
+  addCategory("JS Baseline", [ "JS_BASELINE" ]);
+  addCategory("JS Unoptimized", [ "JS_UNOPT", "BC" ]);
   addCategory("IC", [ "IC" ]);
   addCategory("RegExp", [ "REGEXP" ]);
   addCategory("Other generated", [ "STUB", "BUILTIN" ]);
   addCategory("C++", [ "CPP", "LIB" ]);
-  addCategory("C++/GC", [ "CPPGC" ]);
-  addCategory("C++/Parser", [ "CPPPARSE" ]);
-  addCategory("C++/Bytecode compiler", [ "CPPCOMPBC" ]);
-  addCategory("C++/Compiler", [ "CPPCOMP" ]);
-  addCategory("C++/External", [ "CPPEXT" ]);
+  addCategory("C++/GC", [ "CPP_GC" ]);
+  addCategory("C++/Parser", [ "CPP_PARSE" ]);
+  addCategory("C++/Bytecode Compiler", [ "CPP_COMP_BC" ]);
+  addCategory("C++/Baseline Compiler", [ "CPP_COMP_BASELINE" ]);
+  addCategory("C++/Compiler", [ "CPP_COMP" ]);
+  addCategory("C++/External", [ "CPP_EXT" ]);
   addCategory("Unknown", [ "UNKNOWN" ]);
 
   return { categories, root };
diff --git a/chromium/v8/tools/profview/profview.js b/chromium/v8/tools/profview/profview.js
index 15a74f72405..60fc05e7274 100644
--- a/chromium/v8/tools/profview/profview.js
+++ b/chromium/v8/tools/profview/profview.js
@@ -212,63 +212,91 @@ let main = {
 
 const CATEGORY_COLOR = "#f5f5f5";
 const bucketDescriptors =
-    [ { kinds : [ "JSOPT" ],
-        color : "#64dd17",
-        backgroundColor : "#80e27e",
-        text : "JS Optimized" },
-      { kinds : [ "JSNCI" ],
-        color : "#3289a8",
-        backgroundColor : "#3289a8",
-        text : "JS NCI" },
-      { kinds : [ "JSTURBOPROP" ],
-        color : "#693eb8",
-        backgroundColor : "#a6c452",
-        text : "JS Turboprop" },
-      { kinds : [ "JSBASELINE" ],
-        color : "#b3005b",
-        backgroundColor : "#ff9e80",
-        text : "JS Baseline" },
-      { kinds : [ "JSUNOPT", "BC" ],
-        color : "#dd2c00",
-        backgroundColor : "#ff9e80",
-        text : "JS Unoptimized" },
-      { kinds : [ "IC" ],
-        color : "#ff6d00",
-        backgroundColor : "#ffab40",
-        text : "IC" },
-      { kinds : [ "STUB", "BUILTIN", "REGEXP" ],
-        color : "#ffd600",
-        backgroundColor : "#ffea00",
-        text : "Other generated" },
-      { kinds : [ "CPP", "LIB" ],
-        color : "#304ffe",
-        backgroundColor : "#6ab7ff",
-        text : "C++" },
-      { kinds : [ "CPPEXT" ],
-        color : "#003c8f",
-        backgroundColor : "#c0cfff",
-        text : "C++/external" },
-      { kinds : [ "CPPPARSE" ],
-        color : "#aa00ff",
-        backgroundColor : "#ffb2ff",
-        text : "C++/Parser" },
-      { kinds : [ "CPPCOMPBC" ],
-        color : "#43a047",
-        backgroundColor : "#88c399",
-        text : "C++/Bytecode compiler" },
-      { kinds : [ "CPPCOMP" ],
-        color : "#00e5ff",
-        backgroundColor : "#6effff",
-        text : "C++/Compiler" },
-      { kinds : [ "CPPGC" ],
-        color : "#6200ea",
-        backgroundColor : "#e1bee7",
-        text : "C++/GC" },
-      { kinds : [ "UNKNOWN" ],
-        color : "#bdbdbd",
-        backgroundColor : "#efefef",
-        text : "Unknown" }
-    ];
+  [{
+    kinds: ["JS_OPT"],
+    color: "#64dd17",
+    backgroundColor: "#80e27e",
+    text: "JS Optimized"
+  },
+  {
+    kinds: ["JS_TURBOPROP"],
+    color: "#693eb8",
+    backgroundColor: "#a6c452",
+    text: "JS Turboprop"
+  },
+  {
+    kinds: ["JS_BASELINE"],
+    color: "#b3005b",
+    backgroundColor: "#ff9e80",
+    text: "JS Baseline"
+  },
+  {
+    kinds: ["JS_UNOPT", "BC"],
+    color: "#dd2c00",
+    backgroundColor: "#ff9e80",
+    text: "JS Unoptimized"
+  },
+  {
+    kinds: ["IC"],
+    color: "#ff6d00",
+    backgroundColor: "#ffab40",
+    text: "IC"
+  },
+  {
+    kinds: ["STUB", "BUILTIN", "REGEXP"],
+    color: "#ffd600",
+    backgroundColor: "#ffea00",
+    text: "Other generated"
+  },
+  {
+    kinds: ["CPP", "LIB"],
+    color: "#304ffe",
+    backgroundColor: "#6ab7ff",
+    text: "C++"
+  },
+  {
+    kinds: ["CPP_EXT"],
+    color: "#003c8f",
+    backgroundColor: "#c0cfff",
+    text: "C++/external"
+  },
+  {
+    kinds: ["CPP_PARSE"],
+    color: "#aa00ff",
+    backgroundColor: "#ffb2ff",
+    text: "C++/Parser"
+  },
+  {
+    kinds: ["CPP_COMP_BC"],
+    color: "#43a047",
+    backgroundColor: "#88c399",
+    text: "C++/Bytecode compiler"
+  },
+  {
+    kinds: ["CPP_COMP_BASELINE"],
+    color: "#43a047",
+    backgroundColor: "#5a8000",
+    text: "C++/Baseline compiler"
+  },
+  {
+    kinds: ["CPP_COMP"],
+    color: "#00e5ff",
+    backgroundColor: "#6effff",
+    text: "C++/Compiler"
+  },
+  {
+    kinds: ["CPP_GC"],
+    color: "#6200ea",
+    backgroundColor: "#e1bee7",
+    text: "C++/GC"
+  },
+  {
+    kinds: ["UNKNOWN"],
+    color: "#bdbdbd",
+    backgroundColor: "#efefef",
+    text: "Unknown"
+  }
+  ];
 
 let kindToBucketDescriptor = {};
 for (let i = 0; i < bucketDescriptors.length; i++) {
@@ -294,15 +322,17 @@ function codeTypeToText(type) {
   switch (type) {
     case "UNKNOWN":
       return "Unknown";
-    case "CPPPARSE":
+    case "CPP_PARSE":
       return "C++ Parser";
-    case "CPPCOMPBC":
-      return "C++ Bytecode Compiler)";
-    case "CPPCOMP":
+    case "CPP_COMP_BASELINE":
+      return "C++ Baseline Compiler";
+    case "CPP_COMP_BC":
+      return "C++ Bytecode Compiler";
+    case "CPP_COMP":
       return "C++ Compiler";
-    case "CPPGC":
+    case "CPP_GC":
       return "C++ GC";
-    case "CPPEXT":
+    case "CPP_EXT":
       return "C++ External";
     case "CPP":
       return "C++";
@@ -318,13 +348,13 @@ function codeTypeToText(type) {
       return "Builtin";
     case "REGEXP":
       return "RegExp";
-    case "JSOPT":
+    case "JS_OPT":
       return "JS opt";
-    case "JSNCI":
-      return "JS NCI";
-    case "JSTURBOPROP":
+    case "JS_TURBOPROP":
       return "JS Turboprop";
-    case "JSUNOPT":
+    case "JS_BASELINE":
+      return "JS Baseline";
+    case "JS_UNOPT":
       return "JS unopt";
   }
   console.error("Unknown type: " + type);
diff --git a/chromium/v8/tools/release/auto_roll.py b/chromium/v8/tools/release/auto_roll.py
index ffba545c8f2..76247b1fb3e 100755
--- a/chromium/v8/tools/release/auto_roll.py
+++ b/chromium/v8/tools/release/auto_roll.py
@@ -126,7 +126,7 @@ class UpdateChromiumCheckout(Step):
   def RunStep(self):
     self['json_output']['monitoring_state'] = 'update_chromium'
     cwd = self._options.chromium
-    self.GitCheckout("master", cwd=cwd)
+    self.GitCheckout("main", cwd=cwd)
     self.DeleteBranch("work-branch", cwd=cwd)
     self.GitPull(cwd=cwd)
 
@@ -168,7 +168,7 @@ class UploadCL(Step):
     else:
       print("Dry run - don't upload.")
 
-    self.GitCheckout("master", cwd=cwd)
+    self.GitCheckout("main", cwd=cwd)
     self.GitDeleteBranch("work-branch", cwd=cwd)
 
 class CleanUp(Step):
diff --git a/chromium/v8/tools/release/test_scripts.py b/chromium/v8/tools/release/test_scripts.py
index bfac9a4a34a..7cf5d141301 100755
--- a/chromium/v8/tools/release/test_scripts.py
+++ b/chromium/v8/tools/release/test_scripts.py
@@ -612,7 +612,7 @@ deps = {
       Cmd("git describe --tags roll_hsh", "3.22.4"),
       Cmd("git describe --tags last_roll_hsh", "3.22.2.1"),
       Cmd("git status -s -uno", "", cwd=chrome_dir),
-      Cmd("git checkout -f master", "", cwd=chrome_dir),
+      Cmd("git checkout -f main", "", cwd=chrome_dir),
       Cmd("git branch", "", cwd=chrome_dir),
       Cmd("git pull", "", cwd=chrome_dir),
       Cmd("git fetch origin", ""),
@@ -626,7 +626,7 @@ deps = {
       Cmd("git cl upload --send-mail -f "
           "--cq-dry-run --set-bot-commit --bypass-hooks", "",
           cwd=chrome_dir),
-      Cmd("git checkout -f master", "", cwd=chrome_dir),
+      Cmd("git checkout -f main", "", cwd=chrome_dir),
       Cmd("git branch -D work-branch", "", cwd=chrome_dir),
     ]
     self.Expect(expectations)
diff --git a/chromium/v8/tools/system-analyzer/index.css b/chromium/v8/tools/system-analyzer/index.css
index ad3f24d27ba..53110079b2c 100644
--- a/chromium/v8/tools/system-analyzer/index.css
+++ b/chromium/v8/tools/system-analyzer/index.css
@@ -68,7 +68,7 @@ section {
   border-radius: 8px;
   cursor: pointer;
 }
-::-webkit-scrollbar-thumb:hover { 
+::-webkit-scrollbar-thumb:hover {
   background-color: rgba(128, 128, 128, 0.8);
 }
 
diff --git a/chromium/v8/tools/system-analyzer/index.mjs b/chromium/v8/tools/system-analyzer/index.mjs
index 4b0ed9f9c5f..550838118b3 100644
--- a/chromium/v8/tools/system-analyzer/index.mjs
+++ b/chromium/v8/tools/system-analyzer/index.mjs
@@ -110,7 +110,7 @@ class App {
         entries = entry.entries.concat(entry.sourcePositions);
         break;
       default:
-        throw new Error('Unknown selection type!');
+        throw new Error(`Unknown selection type: ${entry.constructor?.name}`);
     }
     if (entry.sourcePosition) {
       entries.push(entry.sourcePosition);
@@ -134,7 +134,11 @@ class App {
   }
 
   selectEntriesOfSingleType(entries, type) {
-    switch (entries[0]?.constructor ?? type) {
+    const entryType = entries[0]?.constructor ?? type;
+    switch (entryType) {
+      case Script:
+        entries = entries.flatMap(script => script.sourcePositions);
+        return this.showSourcePositions(entries);
       case SourcePosition:
         return this.showSourcePositions(entries);
       case MapLogEntry:
@@ -148,7 +152,7 @@ class App {
       case DeoptLogEntry:
         return this.showDeoptEntries(entries);
       default:
-        throw new Error('Unknown selection type!');
+        throw new Error(`Unknown selection type: ${entryType?.name}`);
     }
   }
 
@@ -205,6 +209,8 @@ class App {
 
   focusLogEntry(entry) {
     switch (entry.constructor) {
+      case Script:
+        return this.focusSourcePosition(entry.sourcePositions[0]);
       case SourcePosition:
         return this.focusSourcePosition(entry);
       case MapLogEntry:
@@ -218,7 +224,7 @@ class App {
       case DeoptLogEntry:
         return this.focusDeoptLogEntry(entry);
       default:
-        throw new Error('Unknown selection type!');
+        throw new Error(`Unknown selection type: ${entry.constructor?.name}`);
     }
   }
 
diff --git a/chromium/v8/tools/system-analyzer/processor.mjs b/chromium/v8/tools/system-analyzer/processor.mjs
index 9685e09ad6b..806cba132c8 100644
--- a/chromium/v8/tools/system-analyzer/processor.mjs
+++ b/chromium/v8/tools/system-analyzer/processor.mjs
@@ -230,17 +230,21 @@ export class Processor extends LogReader {
     this.addSourcePosition(codeEntry, logEntry);
     logEntry.functionSourcePosition = logEntry.sourcePosition;
     // custom parse deopt location
-    if (deoptLocation !== '<unknown>') {
-      const colSeparator = deoptLocation.lastIndexOf(':');
-      const rowSeparator = deoptLocation.lastIndexOf(':', colSeparator - 1);
-      const script = this.getScript(deoptLocation.substring(1, rowSeparator));
-      const line =
-          parseInt(deoptLocation.substring(rowSeparator + 1, colSeparator));
-      const column = parseInt(
-          deoptLocation.substring(colSeparator + 1, deoptLocation.length - 1));
-      logEntry.sourcePosition =
-          script.addSourcePosition(line, column, logEntry);
+    if (deoptLocation === '<unknown>') return;
+    // Handle deopt location for inlined code: <location> inlined at <location>
+    const inlinedPos = deoptLocation.indexOf(' inlined at ');
+    if (inlinedPos > 0) {
+      deoptLocation = deoptLocation.substring(0, inlinedPos)
     }
+    const colSeparator = deoptLocation.lastIndexOf(':');
+    const rowSeparator = deoptLocation.lastIndexOf(':', colSeparator - 1);
+    const script = this.getScript(deoptLocation.substring(1, rowSeparator));
+    if (!script) return;
+    const line =
+        parseInt(deoptLocation.substring(rowSeparator + 1, colSeparator));
+    const column = parseInt(
+        deoptLocation.substring(colSeparator + 1, deoptLocation.length - 1));
+    logEntry.sourcePosition = script.addSourcePosition(line, column, logEntry);
   }
 
   processScriptSource(scriptId, url, source) {
diff --git a/chromium/v8/tools/system-analyzer/view/code-panel-template.html b/chromium/v8/tools/system-analyzer/view/code-panel-template.html
index e04c6be8c18..3622c25062c 100644
--- a/chromium/v8/tools/system-analyzer/view/code-panel-template.html
+++ b/chromium/v8/tools/system-analyzer/view/code-panel-template.html
@@ -11,7 +11,9 @@ found in the LICENSE file. -->
   }
 </style>
 <div class="panel">
-  <h2>Code Panel</h2>
+  <input type="checkbox" id="closer" class="panelCloserInput" checked>
+  <label class="panelCloserLabel" for="closer">▼</label>
+  <h2 class="title">Code Panel</h2>
   <div class="selection">
     <select id="codeSelect"></select>
     <button id="selectedRelatedButton">Select Related Events</button>
diff --git a/chromium/v8/tools/system-analyzer/view/code-panel.mjs b/chromium/v8/tools/system-analyzer/view/code-panel.mjs
index 3b5261e03c3..34e4ad300e4 100644
--- a/chromium/v8/tools/system-analyzer/view/code-panel.mjs
+++ b/chromium/v8/tools/system-analyzer/view/code-panel.mjs
@@ -5,11 +5,11 @@ import {IcLogEntry} from '../log/ic.mjs';
 import {MapLogEntry} from '../log/map.mjs';
 
 import {FocusEvent, SelectionEvent, ToolTipEvent} from './events.mjs';
-import {delay, DOM, formatBytes, formatMicroSeconds, V8CustomElement} from './helper.mjs';
+import {CollapsableElement, delay, DOM, formatBytes, formatMicroSeconds} from './helper.mjs';
 
 DOM.defineCustomElement('view/code-panel',
                         (templateText) =>
-                            class CodePanel extends V8CustomElement {
+                            class CodePanel extends CollapsableElement {
   _timeline;
   _selectedEntries;
   _entry;
@@ -24,19 +24,17 @@ DOM.defineCustomElement('view/code-panel',
   set timeline(timeline) {
     this._timeline = timeline;
     this.$('.panel').style.display = timeline.isEmpty() ? 'none' : 'inherit';
-    this.update();
+    this.requestUpdate();
   }
 
   set selectedEntries(entries) {
     this._selectedEntries = entries;
-    // TODO: add code selection dropdown
-    this._updateSelect();
     this.entry = entries.first();
   }
 
   set entry(entry) {
     this._entry = entry;
-    this.update();
+    this.requestUpdate();
   }
 
   get _disassemblyNode() {
@@ -52,12 +50,15 @@ DOM.defineCustomElement('view/code-panel',
   }
 
   _update() {
+    this._updateSelect();
     this._disassemblyNode.innerText = this._entry?.disassemble ?? '';
     this._sourceNode.innerText = this._entry?.source ?? '';
   }
 
   _updateSelect() {
     const select = this._codeSelectNode;
+    if (select.data === this._selectedEntries) return;
+    select.data = this._selectedEntries;
     select.options.length = 0;
     const sorted =
         this._selectedEntries.slice().sort((a, b) => a.time - b.time);
diff --git a/chromium/v8/tools/system-analyzer/view/helper.mjs b/chromium/v8/tools/system-analyzer/view/helper.mjs
index 780864ef5a0..44da06ced4d 100644
--- a/chromium/v8/tools/system-analyzer/view/helper.mjs
+++ b/chromium/v8/tools/system-analyzer/view/helper.mjs
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-class CSSColor {
+export class CSSColor {
   static _cache = new Map();
 
   static get(name) {
@@ -121,7 +121,7 @@ class CSSColor {
   }
 }
 
-class DOM {
+export class DOM {
   static element(type, classes) {
     const node = document.createElement(type);
     if (classes === undefined) return node;
@@ -185,19 +185,18 @@ class DOM {
   }
 }
 
-function $(id) {
+export function $(id) {
   return document.querySelector(id)
 }
 
-class V8CustomElement extends HTMLElement {
+export class V8CustomElement extends HTMLElement {
   _updateTimeoutId;
-  _updateCallback = this._update.bind(this);
+  _updateCallback = this.forceUpdate.bind(this);
 
   constructor(templateText) {
     super();
     const shadowRoot = this.attachShadow({mode: 'open'});
     shadowRoot.innerHTML = templateText;
-    this._updateCallback = this._update.bind(this);
   }
 
   $(id) {
@@ -208,7 +207,7 @@ class V8CustomElement extends HTMLElement {
     return this.shadowRoot.querySelectorAll(query);
   }
 
-  update(useAnimation = false) {
+  requestUpdate(useAnimation = false) {
     if (useAnimation) {
       window.cancelAnimationFrame(this._updateTimeoutId);
       this._updateTimeoutId =
@@ -221,12 +220,54 @@ class V8CustomElement extends HTMLElement {
     }
   }
 
+  forceUpdate() {
+    this._update();
+  }
+
   _update() {
     throw Error('Subclass responsibility');
   }
 }
 
-class Chunked {
+export class CollapsableElement extends V8CustomElement {
+  constructor(templateText) {
+    super(templateText);
+    this._hasPendingUpdate = false;
+    this._closer.onclick = _ => this.tryUpdateOnVisibilityChange();
+  }
+
+  get _closer() {
+    return this.$('#closer');
+  }
+
+  _contentIsVisible() {
+    return !this._closer.checked;
+  }
+
+  requestUpdate(useAnimation = false) {
+    // A pending update will be resolved later, no need to try again.
+    if (this._hasPendingUpdate) return;
+    this._hasPendingUpdate = true;
+    this.requestUpdateIfVisible(useAnimation);
+  }
+
+  tryUpdateOnVisibilityChange() {
+    if (!this._hasPendingUpdate) return;
+    this.requestUpdateIfVisible(true);
+  }
+
+  requestUpdateIfVisible(useAnimation) {
+    if (!this._contentIsVisible()) return;
+    return super.requestUpdate(useAnimation);
+  }
+
+  forceUpdate() {
+    this._hasPendingUpdate = false;
+    super.forceUpdate();
+  }
+}
+
+export class Chunked {
   constructor(iterable, limit) {
     this._iterator = iterable[Symbol.iterator]();
     this._limit = limit;
@@ -248,7 +289,7 @@ class Chunked {
   }
 }
 
-class LazyTable {
+export class LazyTable {
   constructor(table, rowData, rowElementCreator, limit = 100) {
     this._table = table;
     this._chunkedRowData = new Chunked(rowData, limit);
@@ -258,22 +299,25 @@ class LazyTable {
     } else {
       table.replaceChild(DOM.tbody(), table.tBodies[0]);
     }
-    if (!table.tFoot) {
-      const td = table.appendChild(DOM.element('tfoot'))
-                     .appendChild(DOM.tr())
-                     .appendChild(DOM.td());
-      for (let count of [10, 100]) {
-        const button = DOM.element('button');
-        button.innerText = `+${count}`;
-        button.onclick = (e) => this._addMoreRows(count);
-        td.appendChild(button);
-      }
-      td.setAttribute('colspan', 100);
-    }
+    if (!table.tFoot) this._addFooter();
     table.tFoot.addEventListener('click', this._clickHandler);
     this._addMoreRows();
   }
 
+  _addFooter() {
+    const td = DOM.td();
+    td.setAttribute('colspan', 100);
+    for (let addCount of [10, 100, 250, 500]) {
+      const button = DOM.element('button');
+      button.innerText = `+${addCount}`;
+      button.onclick = (e) => this._addMoreRows(addCount);
+      td.appendChild(button);
+    }
+    this._table.appendChild(DOM.element('tfoot'))
+        .appendChild(DOM.tr())
+        .appendChild(td);
+  }
+
   _addMoreRows(count = undefined) {
     const fragment = new DocumentFragment();
     for (let row of this._chunkedRowData.next(count)) {
@@ -304,11 +348,4 @@ export function gradientStopsFromGroups(
   return stops;
 }
 
-export * from '../helper.mjs';
-export {
-  DOM,
-  $,
-  V8CustomElement,
-  CSSColor,
-  LazyTable,
-};
+export * from '../helper.mjs';
\ No newline at end of file
diff --git a/chromium/v8/tools/system-analyzer/view/list-panel-template.html b/chromium/v8/tools/system-analyzer/view/list-panel-template.html
index 4714f97c02f..fb38f5b4598 100644
--- a/chromium/v8/tools/system-analyzer/view/list-panel-template.html
+++ b/chromium/v8/tools/system-analyzer/view/list-panel-template.html
@@ -30,11 +30,13 @@ found in the LICENSE file. -->
     text-align: left;
     cursor: -webkit-zoom-in;
     color: rgba(var(--border-color), 1);
+    user-select: none;
   }
 
   .toggle::before {
     content: "▶";
   }
+
   .open .toggle::before {
     content: "▼";
   }
@@ -58,7 +60,7 @@ found in the LICENSE file. -->
 </style>
 
 <div class="panel">
-  <input type="checkbox" id="closer" class="panelCloserInput">
+  <input type="checkbox" id="closer" class="panelCloserInput" checked>
   <label class="panelCloserLabel" for="closer">▼</label>
   <h2 id="title"></h2>
   <div class="selection">
diff --git a/chromium/v8/tools/system-analyzer/view/list-panel.mjs b/chromium/v8/tools/system-analyzer/view/list-panel.mjs
index 85e3cd47e28..bc3b2f89d58 100644
--- a/chromium/v8/tools/system-analyzer/view/list-panel.mjs
+++ b/chromium/v8/tools/system-analyzer/view/list-panel.mjs
@@ -5,23 +5,24 @@
 import {Script, SourcePosition} from '../../profile.mjs';
 import {LogEntry} from '../log/log.mjs';
 
-import {FocusEvent} from './events.mjs';
+import {FocusEvent, ToolTipEvent} from './events.mjs';
 import {groupBy, LazyTable} from './helper.mjs';
-import {DOM, V8CustomElement} from './helper.mjs';
+import {CollapsableElement, DOM} from './helper.mjs';
 
 DOM.defineCustomElement('view/list-panel',
                         (templateText) =>
-                            class ListPanel extends V8CustomElement {
+                            class ListPanel extends CollapsableElement {
   _selectedLogEntries = [];
   _displayedLogEntries = [];
   _timeline;
 
   _detailsClickHandler = this._handleDetailsClick.bind(this);
   _logEntryClickHandler = this._handleLogEntryClick.bind(this);
+  _logEntryMouseOverHandler = this._logEntryMouseOverHandler.bind(this);
 
   constructor() {
     super(templateText);
-    this.groupKey.addEventListener('change', e => this.update());
+    this.groupKey.addEventListener('change', e => this.requestUpdate());
     this.showAllRadio.onclick = _ => this._showEntries(this._timeline);
     this.showTimerangeRadio.onclick = _ =>
         this._showEntries(this._timeline.selectionOrSelf);
@@ -72,9 +73,11 @@ DOM.defineCustomElement('view/list-panel',
   get showAllRadio() {
     return this.$('#show-all');
   }
+
   get showTimerangeRadio() {
     return this.$('#show-timerange');
   }
+
   get showSelectionRadio() {
     return this.$('#show-selection');
   }
@@ -95,7 +98,7 @@ DOM.defineCustomElement('view/list-panel',
 
   _showEntries(entries) {
     this._displayedLogEntries = entries;
-    this.update();
+    this.requestUpdate();
   }
 
   _update() {
@@ -123,6 +126,12 @@ DOM.defineCustomElement('view/list-panel',
     this.dispatchEvent(new FocusEvent(group.key));
   }
 
+  _logEntryMouseOverHandler(e) {
+    const group = e.currentTarget.group;
+    this.dispatchEvent(
+        new ToolTipEvent(group.key.toStringLong(), e.currentTarget));
+  }
+
   _handleDetailsClick(event) {
     event.stopPropagation();
     const tr = event.target.parentNode;
@@ -182,6 +191,7 @@ DOM.defineCustomElement('view/list-panel',
       const valueTd = tr.appendChild(DOM.td(`${group.key}`, 'key'));
       if (this._isClickable(group.key)) {
         tr.onclick = this._logEntryClickHandler;
+        tr.onmouseover = this._logEntryMouseOverHandler;
         valueTd.classList.add('clickable');
       }
       return tr;
diff --git a/chromium/v8/tools/system-analyzer/view/map-panel-template.html b/chromium/v8/tools/system-analyzer/view/map-panel-template.html
index 8a2b23ee3d4..4790e376f99 100644
--- a/chromium/v8/tools/system-analyzer/view/map-panel-template.html
+++ b/chromium/v8/tools/system-analyzer/view/map-panel-template.html
@@ -11,7 +11,7 @@ found in the LICENSE file. -->
   }
 </style>
 <div class="panel">
-  <input type="checkbox" id="closer" class="panelCloserInput">
+  <input type="checkbox" id="closer" class="panelCloserInput" checked>
   <label class="panelCloserLabel" for="closer">▼</label>
   <h2>Map Panel</h2>
   <div class="selection">
diff --git a/chromium/v8/tools/system-analyzer/view/map-panel.mjs b/chromium/v8/tools/system-analyzer/view/map-panel.mjs
index 7ee2325f34c..be00ef01246 100644
--- a/chromium/v8/tools/system-analyzer/view/map-panel.mjs
+++ b/chromium/v8/tools/system-analyzer/view/map-panel.mjs
@@ -7,100 +7,103 @@ import './map-panel/map-transitions.mjs';
 import {MapLogEntry} from '../log/map.mjs';
 
 import {FocusEvent} from './events.mjs';
-import {DOM, V8CustomElement} from './helper.mjs';
-
-DOM.defineCustomElement(
-    'view/map-panel', (templateText) => class MapPanel extends V8CustomElement {
-      _map;
-      _timeline;
-      _selectedLogEntries = [];
-      _displayedLogEntries = [];
-
-      constructor() {
-        super(templateText);
-        this.searchBarBtn.addEventListener('click', e => this._handleSearch(e));
-        this.showAllRadio.onclick = _ => this._showEntries(this._timeline);
-        this.showTimerangeRadio.onclick = _ =>
-            this._showEntries(this._timeline.selectionOrSelf);
-        this.showSelectionRadio.onclick = _ =>
-            this._showEntries(this._selectedLogEntries);
-      }
-
-      get showAllRadio() {
-        return this.$('#show-all');
-      }
-      get showTimerangeRadio() {
-        return this.$('#show-timerange');
-      }
-      get showSelectionRadio() {
-        return this.$('#show-selection');
-      }
-
-      get mapTransitionsPanel() {
-        return this.$('#map-transitions');
-      }
-
-      get mapDetailsTransitionsPanel() {
-        return this.$('#map-details-transitions');
-      }
-
-      get mapDetailsPanel() {
-        return this.$('#map-details');
-      }
-
-      get searchBarBtn() {
-        return this.$('#searchBarBtn');
-      }
-
-      get searchBar() {
-        return this.$('#searchBar');
-      }
-
-      set timeline(timeline) {
-        console.assert(timeline !== undefined, 'timeline undefined!');
-        this._timeline = timeline;
-        this.$('.panel').style.display =
-            timeline.isEmpty() ? 'none' : 'inherit';
-        this.mapTransitionsPanel.timeline = timeline;
-        this.mapDetailsTransitionsPanel.timeline = timeline;
-      }
-
-      set selectedLogEntries(entries) {
-        if (entries === this._timeline.selection) {
-          this.showTimerangeRadio.click();
-        } else if (entries == this._timeline) {
-          this.showAllRadio.click();
-        } else {
-          this._selectedLogEntries = entries;
-          this.showSelectionRadio.click();
-        }
-      }
-
-      set map(map) {
-        this._map = map;
-        this.mapDetailsTransitionsPanel.selectedLogEntries = [map];
-        this.mapDetailsPanel.map = map;
-      }
-
-      _showEntries(entries) {
-        this._displayedLogEntries = entries;
-        this.mapTransitionsPanel.selectedLogEntries = entries;
-      }
-
-      update() {
-        // nothing to do
-      }
-
-      _handleSearch(e) {
-        let searchBar = this.$('#searchBarInput');
-        let searchBarInput = searchBar.value;
-        // access the map from model cache
-        let selectedMap = MapLogEntry.get(searchBarInput);
-        if (selectedMap) {
-          searchBar.className = 'success';
-          this.dispatchEvent(new FocusEvent(selectedMap));
-        } else {
-          searchBar.className = 'failure';
-        }
-      }
-    });
+import {CollapsableElement, DOM} from './helper.mjs';
+
+DOM.defineCustomElement('view/map-panel',
+                        (templateText) =>
+                            class MapPanel extends CollapsableElement {
+  _map;
+  _timeline;
+  _selectedLogEntries = [];
+  _displayedLogEntries = [];
+
+  constructor() {
+    super(templateText);
+    this.searchBarBtn.addEventListener('click', e => this._handleSearch(e));
+    this.showAllRadio.onclick = _ => this._showEntries(this._timeline);
+    this.showTimerangeRadio.onclick = _ =>
+        this._showEntries(this._timeline.selectionOrSelf);
+    this.showSelectionRadio.onclick = _ =>
+        this._showEntries(this._selectedLogEntries);
+  }
+
+  get showAllRadio() {
+    return this.$('#show-all');
+  }
+
+  get showTimerangeRadio() {
+    return this.$('#show-timerange');
+  }
+
+  get showSelectionRadio() {
+    return this.$('#show-selection');
+  }
+
+  get mapTransitionsPanel() {
+    return this.$('#map-transitions');
+  }
+
+  get mapDetailsTransitionsPanel() {
+    return this.$('#map-details-transitions');
+  }
+
+  get mapDetailsPanel() {
+    return this.$('#map-details');
+  }
+
+  get searchBarBtn() {
+    return this.$('#searchBarBtn');
+  }
+
+  get searchBar() {
+    return this.$('#searchBar');
+  }
+
+  set timeline(timeline) {
+    console.assert(timeline !== undefined, 'timeline undefined!');
+    this._timeline = timeline;
+    this.$('.panel').style.display = timeline.isEmpty() ? 'none' : 'inherit';
+    this.mapTransitionsPanel.timeline = timeline;
+    this.mapDetailsTransitionsPanel.timeline = timeline;
+  }
+
+  set selectedLogEntries(entries) {
+    if (entries === this._timeline.selection) {
+      this.showTimerangeRadio.click();
+    } else if (entries == this._timeline) {
+      this.showAllRadio.click();
+    } else {
+      this._selectedLogEntries = entries;
+      this.showSelectionRadio.click();
+    }
+  }
+
+  set map(map) {
+    this._map = map;
+    this.requestUpdate();
+  }
+
+  _showEntries(entries) {
+    this._displayedLogEntries = entries;
+    this.requestUpdate();
+  }
+
+  _update() {
+    this.mapDetailsTransitionsPanel.selectedLogEntries = [this._map];
+    this.mapDetailsPanel.map = this._map;
+    this.mapTransitionsPanel.selectedLogEntries = this._displayedLogEntries;
+  }
+
+  _handleSearch(e) {
+    const searchBar = this.$('#searchBarInput');
+    const searchBarInput = searchBar.value;
+    // access the map from model cache
+    const selectedMap = MapLogEntry.get(searchBarInput);
+    if (selectedMap) {
+      searchBar.className = 'success';
+      this.dispatchEvent(new FocusEvent(selectedMap));
+    } else {
+      searchBar.className = 'failure';
+    }
+  }
+});
diff --git a/chromium/v8/tools/system-analyzer/view/map-panel/map-details.mjs b/chromium/v8/tools/system-analyzer/view/map-panel/map-details.mjs
index 446475a5b08..a8ea27e2e4e 100644
--- a/chromium/v8/tools/system-analyzer/view/map-panel/map-details.mjs
+++ b/chromium/v8/tools/system-analyzer/view/map-panel/map-details.mjs
@@ -25,7 +25,7 @@ DOM.defineCustomElement(
       set map(map) {
         if (this._map === map) return;
         this._map = map;
-        this.update();
+        this.requestUpdate();
       }
 
       _update() {
diff --git a/chromium/v8/tools/system-analyzer/view/map-panel/map-transitions.mjs b/chromium/v8/tools/system-analyzer/view/map-panel/map-transitions.mjs
index f60bd37d392..fbe78f91563 100644
--- a/chromium/v8/tools/system-analyzer/view/map-panel/map-transitions.mjs
+++ b/chromium/v8/tools/system-analyzer/view/map-panel/map-transitions.mjs
@@ -37,7 +37,7 @@ DOM.defineCustomElement(
 
       set selectedLogEntries(list) {
         this._selectedLogEntries = list;
-        this.update();
+        this.requestUpdate();
       }
 
       _update() {
diff --git a/chromium/v8/tools/system-analyzer/view/script-panel-template.html b/chromium/v8/tools/system-analyzer/view/script-panel-template.html
index 27fd3d83eb6..ab5c3f95f35 100644
--- a/chromium/v8/tools/system-analyzer/view/script-panel-template.html
+++ b/chromium/v8/tools/system-analyzer/view/script-panel-template.html
@@ -40,11 +40,15 @@ found in the LICENSE file. -->
 
   .marked {
     background-color: var(--secondary-color);
+    box-shadow: 0px 0px 2px 3px var(--secondary-color);
+    animation-name: pulse;
+    animation-duration: 3s;
+    animation-delay: 500ms;
   }
 
   @keyframes pulse {
     0% {
-      box-shadow: 0px 0px 0px 0px var(--secondary-color);
+      box-shadow: 0px 0px 0px 3px var(--secondary-color);
     }
     5% {
       box-shadow: 0px 0px 0px 10px var(--secondary-color);
@@ -56,11 +60,13 @@ found in the LICENSE file. -->
       box-shadow: 0px 0px 0px 10px var(--secondary-color);
     }
     20% {
-      box-shadow: 0px 0px 0px 0px var(--secondary-color);
+      box-shadow: 0px 0px 2px 3px var(--secondary-color);
     }
   }
 </style>
 <div class="panel">
+  <input type="checkbox" id="closer" class="panelCloserInput" checked>
+  <label class="panelCloserLabel" for="closer">▼</label>
   <h2>Source Panel</h2>
   <div class="selection">
     <select id="script-dropdown"></select>
diff --git a/chromium/v8/tools/system-analyzer/view/script-panel.mjs b/chromium/v8/tools/system-analyzer/view/script-panel.mjs
index b0dac6960c3..6f5befcc160 100644
--- a/chromium/v8/tools/system-analyzer/view/script-panel.mjs
+++ b/chromium/v8/tools/system-analyzer/view/script-panel.mjs
@@ -5,11 +5,11 @@ import {groupBy} from '../helper.mjs';
 import {App} from '../index.mjs'
 
 import {SelectRelatedEvent, ToolTipEvent} from './events.mjs';
-import {CSSColor, delay, DOM, formatBytes, gradientStopsFromGroups, V8CustomElement} from './helper.mjs';
+import {CollapsableElement, CSSColor, delay, DOM, formatBytes, gradientStopsFromGroups} from './helper.mjs';
 
 DOM.defineCustomElement('view/script-panel',
                         (templateText) =>
-                            class SourcePanel extends V8CustomElement {
+                            class SourcePanel extends CollapsableElement {
   _selectedSourcePositions = [];
   _sourcePositionsToMarkNodes = [];
   _scripts = [];
@@ -110,7 +110,7 @@ DOM.defineCustomElement('view/script-panel',
     if (!sourcePosition) return;
     const markNode = this._sourcePositionsToMarkNodes.get(sourcePosition);
     markNode.scrollIntoView(
-        {behavior: 'smooth', block: 'nearest', inline: 'center'});
+        {behavior: 'auto', block: 'center', inline: 'center'});
   }
 
   _handleSelectScript(e) {
diff --git a/chromium/v8/tools/system-analyzer/view/timeline/timeline-track.mjs b/chromium/v8/tools/system-analyzer/view/timeline/timeline-track.mjs
index 60216af2eef..6f05b772d81 100644
--- a/chromium/v8/tools/system-analyzer/view/timeline/timeline-track.mjs
+++ b/chromium/v8/tools/system-analyzer/view/timeline/timeline-track.mjs
@@ -112,7 +112,7 @@ DOM.defineCustomElement('view/timeline/timeline-track',
   _updateChunks() {
     this._chunks =
         this._timeline.chunks(this.nofChunks, this._legend.filterPredicate);
-    this.update();
+    this.requestUpdate();
   }
 
   get chunks() {
@@ -180,7 +180,7 @@ DOM.defineCustomElement('view/timeline/timeline-track',
         node.ondblclick = this._chunkDoubleClickHandler;
       }
       const style = node.style;
-      style.left = `${((chunk.start - start) * this._timeToPixel) | 0}px`;
+      style.left = `${i * kChunkWidth}px`;
       style.height = `${height | 0}px`;
       style.backgroundImage = this._createBackgroundImage(chunk);
       node.chunk = chunk;
diff --git a/chromium/v8/tools/system-analyzer/view/tool-tip-template.html b/chromium/v8/tools/system-analyzer/view/tool-tip-template.html
index b0e9c72c45c..dc56997825f 100644
--- a/chromium/v8/tools/system-analyzer/view/tool-tip-template.html
+++ b/chromium/v8/tools/system-analyzer/view/tool-tip-template.html
@@ -24,6 +24,7 @@ found in the LICENSE file. -->
   .textContent {
     font-family: monospace;
     white-space: pre;
+    overflow-wrap: anywhere;
     overflow-x: hidden;
     max-width: 500px;
   }
diff --git a/chromium/v8/tools/system-analyzer/view/tool-tip.mjs b/chromium/v8/tools/system-analyzer/view/tool-tip.mjs
index 896c04dd298..a01ee1bdbf6 100644
--- a/chromium/v8/tools/system-analyzer/view/tool-tip.mjs
+++ b/chromium/v8/tools/system-analyzer/view/tool-tip.mjs
@@ -16,9 +16,10 @@ DOM.defineCustomElement(
             this.hide();
           } else {
             this.show();
-            this.update(true);
+            this.requestUpdate(true);
           }
         });
+        document.addEventListener('click', (e) => this.hide());
       }
 
       _update() {
@@ -31,7 +32,7 @@ DOM.defineCustomElement(
           rect.y += rect.height;
         }
         this._setPosition(rect, atRight, atBottom);
-        this.update(true);
+        this.requestUpdate(true);
       }
 
       set positionOrTargetNode(positionOrTargetNode) {
@@ -47,7 +48,7 @@ DOM.defineCustomElement(
         this._targetNode = targetNode;
         if (targetNode) {
           this._intersectionObserver.observe(targetNode);
-          this.update(true);
+          this.requestUpdate(true);
         }
       }
 
diff --git a/chromium/v8/tools/testrunner/base_runner.py b/chromium/v8/tools/testrunner/base_runner.py
index fdaf0370a17..b6889a3773a 100644
--- a/chromium/v8/tools/testrunner/base_runner.py
+++ b/chromium/v8/tools/testrunner/base_runner.py
@@ -172,6 +172,7 @@ class BuildConfig(object):
     self.cfi_vptr = build_config['is_cfi']
     self.control_flow_integrity = build_config['v8_control_flow_integrity']
     self.concurrent_marking = build_config['v8_enable_concurrent_marking']
+    self.single_generation = build_config['v8_enable_single_generation']
     self.dcheck_always_on = build_config['dcheck_always_on']
     self.gcov_coverage = build_config['is_gcov_coverage']
     self.is_android = build_config['is_android']
@@ -189,6 +190,8 @@ class BuildConfig(object):
     self.verify_csa = build_config['v8_enable_verify_csa']
     self.lite_mode = build_config['v8_enable_lite_mode']
     self.pointer_compression = build_config['v8_enable_pointer_compression']
+    self.pointer_compression_shared_cage = build_config['v8_enable_pointer_compression_shared_cage']
+    self.third_party_heap = build_config['v8_enable_third_party_heap']
     self.webassembly = build_config['v8_enable_webassembly']
     # Export only for MIPS target
     if self.arch in ['mips', 'mipsel', 'mips64', 'mips64el']:
@@ -229,6 +232,10 @@ class BuildConfig(object):
       detected_options.append('lite_mode')
     if self.pointer_compression:
       detected_options.append('pointer_compression')
+    if self.pointer_compression_shared_cage:
+      detected_options.append('pointer_compression_shared_cage')
+    if self.third_party_heap:
+      detected_options.append('third_party_heap')
     if self.webassembly:
       detected_options.append('webassembly')
 
@@ -351,7 +358,7 @@ class BaseTestRunner(object):
 
     # Progress
     parser.add_option("-p", "--progress",
-                      choices=PROGRESS_INDICATORS.keys(), default="mono",
+                      choices=list(PROGRESS_INDICATORS), default="mono",
                       help="The style of progress indicator (verbose, dots, "
                            "color, mono)")
     parser.add_option("--json-test-results",
@@ -638,7 +645,7 @@ class BaseTestRunner(object):
       self.build_config.arch in ['mipsel', 'mips', 'mips64', 'mips64el'] and
       self.build_config.mips_arch_variant)
 
-    no_simd_sse = any(
+    no_simd_hardware = any(
         i in options.extra_flags for i in ['--noenable-sse3',
                                            '--no-enable-sse3'
                                            '--noenable-ssse3',
@@ -646,10 +653,16 @@ class BaseTestRunner(object):
                                            '--noenable-sse4-1',
                                            '--no-enable-sse4_1'])
 
-    # Set no_simd_sse on architectures without Simd enabled.
+    # Set no_simd_hardware on architectures without Simd enabled.
     if self.build_config.arch == 'mips64el' or \
        self.build_config.arch == 'mipsel':
-       no_simd_sse = not simd_mips
+       no_simd_hardware = not simd_mips
+
+    # Ppc64 processors earlier than POWER9 do not support Simd instructions
+    if self.build_config.arch == 'ppc64' and \
+       not self.build_config.simulator_run and \
+       utils.GuessPowerProcessorVersion() < 9:
+       no_simd_hardware = True
 
     return {
       "arch": self.build_config.arch,
@@ -658,6 +671,7 @@ class BaseTestRunner(object):
       "cfi_vptr": self.build_config.cfi_vptr,
       "control_flow_integrity": self.build_config.control_flow_integrity,
       "concurrent_marking": self.build_config.concurrent_marking,
+      "single_generation": self.build_config.single_generation,
       "dcheck_always_on": self.build_config.dcheck_always_on,
       "deopt_fuzzer": False,
       "endurance_fuzzer": False,
@@ -673,7 +687,7 @@ class BaseTestRunner(object):
       "msan": self.build_config.msan,
       "no_harness": options.no_harness,
       "no_i18n": self.build_config.no_i18n,
-      "no_simd_sse": no_simd_sse,
+      "no_simd_hardware": no_simd_hardware,
       "novfp3": False,
       "optimize_for_size": "--optimize-for-size" in options.extra_flags,
       "predictable": self.build_config.predictable,
@@ -681,11 +695,13 @@ class BaseTestRunner(object):
       "simulator_run": self.build_config.simulator_run and
                        not options.dont_skip_simulator_slow_tests,
       "system": self.target_os,
+      "third_party_heap": self.build_config.third_party_heap,
       "tsan": self.build_config.tsan,
       "ubsan_vptr": self.build_config.ubsan_vptr,
       "verify_csa": self.build_config.verify_csa,
       "lite_mode": self.build_config.lite_mode,
       "pointer_compression": self.build_config.pointer_compression,
+      "pointer_compression_shared_cage": self.build_config.pointer_compression_shared_cage,
     }
 
   def _runner_flags(self):
@@ -718,6 +734,8 @@ class BaseTestRunner(object):
       factor *= 2
     if self.build_config.predictable:
       factor *= 4
+    if self.build_config.tsan:
+      factor *= 1.5
     if self.build_config.use_sanitizer:
       factor *= 1.5
     if self.build_config.is_full_debug:
diff --git a/chromium/v8/tools/testrunner/local/statusfile.py b/chromium/v8/tools/testrunner/local/statusfile.py
index 6c2cc01fb87..b6f97cd5641 100644
--- a/chromium/v8/tools/testrunner/local/statusfile.py
+++ b/chromium/v8/tools/testrunner/local/statusfile.py
@@ -282,7 +282,7 @@ def ReadStatusFile(content, variables):
 
 def _ReadSection(section, variables, rules, prefix_rules):
   assert type(section) == dict
-  for rule, outcome_list in section.iteritems():
+  for rule, outcome_list in section.items():
     assert type(rule) == str
 
     if rule[-1] == '*':
diff --git a/chromium/v8/tools/testrunner/local/utils.py b/chromium/v8/tools/testrunner/local/utils.py
index 8fdc16b4bb7..94429a9fde9 100644
--- a/chromium/v8/tools/testrunner/local/utils.py
+++ b/chromium/v8/tools/testrunner/local/utils.py
@@ -97,6 +97,58 @@ def GuessOS():
     return None
 
 
+# Returns power processor version, taking compatibility mode into account.
+# (Power9 running in Power8 compatibility mode returns 8)
+# Only useful if arch is ppc64
+def GuessPowerProcessorVersion():
+  import ctypes, ctypes.util
+  os = GuessOS()
+  if os == 'linux':
+    AT_PLATFORM = 15 # from linux/auxvec.h
+    _LIBC = ctypes.CDLL(ctypes.util.find_library('c'))
+    _LIBC.getauxval.argtypes = [ctypes.c_ulong]
+    _LIBC.getauxval.restype = ctypes.c_char_p
+    at_platform = _LIBC.getauxval(AT_PLATFORM).decode('utf-8').lower()
+    if at_platform.startswith('power6'):
+      return 6
+    elif at_platform.startswith('power7'):
+      return 7
+    elif at_platform.startswith('power8'):
+      return 8
+    elif at_platform.startswith('power9'):
+      return 9
+    elif at_platform.startswith('power10'):
+      return 10
+    else:
+      raise Exception('Unable to guess power processor version')
+  elif os == 'aix':
+    # covers aix and os400
+    RTLD_MEMBER = 0x00040000
+    _LIBC = ctypes.CDLL(ctypes.util.find_library('c'),
+                        ctypes.DEFAULT_MODE | RTLD_MEMBER)
+    class _system_configuration(ctypes.Structure):
+      _fields_ = [
+        ('architecture', ctypes.c_int),
+        ('implementation', ctypes.c_int),
+      ]
+    cfg = _system_configuration.in_dll(_LIBC, '_system_configuration')
+    # Values found in sys/systemcfg.h
+    if cfg.implementation == 0x4000:
+      return 6
+    elif cfg.implementation == 0x8000:
+      return 7
+    elif cfg.implementation == 0x10000:
+      return 8
+    elif cfg.implementation == 0x20000:
+      return 9
+    elif cfg.implementation == 0x40000:
+      return 10
+    else:
+      raise Exception('Unable to guess power processor version')
+  else:
+    raise Exception('Unable to guess power processor version')
+
+
 def UseSimulator(arch):
   machine = platform.machine()
   return (machine and
diff --git a/chromium/v8/tools/testrunner/local/variants.py b/chromium/v8/tools/testrunner/local/variants.py
index 0af6d3ab0e6..e214de05404 100644
--- a/chromium/v8/tools/testrunner/local/variants.py
+++ b/chromium/v8/tools/testrunner/local/variants.py
@@ -44,6 +44,7 @@ ALL_VARIANT_FLAGS = {
   "instruction_scheduling": [["--turbo-instruction-scheduling"]],
   "stress_instruction_scheduling": [["--turbo-stress-instruction-scheduling"]],
   "top_level_await": [["--harmony-top-level-await"]],
+  "wasm_write_protect_code": [["--wasm-write-protect-code-memory"]],
 }
 
 # Flags that lead to a contradiction with the flags provided by the respective
@@ -59,9 +60,9 @@ INCOMPATIBLE_FLAGS_PER_VARIANT = {
   "slow_path": ["--no-force-slow-path"],
   "stress_concurrent_allocation": ["--single-threaded-gc", "--predictable"],
   "stress_concurrent_inlining": ["--single-threaded", "--predictable",
-                                 "--no-turbo-direct-heap-access"],
+                                 "--no-concurrent-inlining"],
+  "concurrent_inlining": ["--no-concurrent-inlining"],
   "stress_incremental_marking": ["--no-stress-incremental-marking"],
-  "future": ["--no-turbo-direct-heap-access"],
   "stress_js_bg_compile_wasm_code_gc": ["--no-stress-background-compile"],
   "stress": ["--no-stress-opt", "--always-opt", "--no-always-opt", "--liftoff",
              "--max-inlined-bytecode-size=*",
@@ -69,16 +70,17 @@ INCOMPATIBLE_FLAGS_PER_VARIANT = {
              "--wasm-generic-wrapper"],
   "sparkplug": ["--jitless", "--no-sparkplug" ],
   "always_sparkplug": ["--jitless", "--no-sparkplug", "--no-always-sparkplug"],
-  "turboprop": ["--interrupt-budget=*", "--no-turbo-direct-heap-access",
-                "--no-turboprop"],
-  "turboprop_as_toptier": ["--interrupt-budget=*",
-                           "--no-turbo-direct-heap-access", "--no-turboprop",
+  "turboprop": ["--interrupt-budget=*", "--no-turboprop"],
+  "turboprop_as_toptier": ["--interrupt-budget=*", "--no-turboprop",
                            "--no-turboprop-as-toptier"],
   "code_serializer": ["--cache=after-execute", "--cache=full-code-cache",
                       "--cache=none"],
   "no_local_heaps": ["--concurrent-inlining", "--turboprop"],
   "experimental_regexp": ["--no-enable-experimental-regexp-engine",
                           "--no-default-to-experimental-regexp-engine"],
+  # There is a negative implication: --perf-prof disables
+  # --wasm-write-protect-code-memory.
+  "wasm_write_protect_code": ["--perf-prof"],
 }
 
 # Flags that lead to a contradiction under certain build variables.
@@ -101,6 +103,8 @@ INCOMPATIBLE_FLAGS_PER_BUILD_VARIABLE = {
 # The conflicts might be directly contradictory flags or be caused by the
 # implications defined in flag-definitions.h.
 INCOMPATIBLE_FLAGS_PER_EXTRA_FLAG = {
+  "--concurrent-inlining":
+        INCOMPATIBLE_FLAGS_PER_VARIANT["concurrent_inlining"],
   "--concurrent-recompilation": ["--no-concurrent-recompilation", "--predictable"],
   "--enable-armv8": ["--no-enable-armv8"],
   "--gc-interval=*": ["--gc-interval=*"],
@@ -109,9 +113,9 @@ INCOMPATIBLE_FLAGS_PER_EXTRA_FLAG = {
   "--no-enable-sse4-1": ["--enable-sse4-1"],
   "--optimize-for-size": ["--max-semi-space-size=*"],
   "--stress_concurrent_allocation": ["--single-threaded-gc", "--predictable"],
-  "--stress_concurrent_inlining": ["--single-threaded", "--predictable"],
+  "--stress-concurrent-inlining":
+        INCOMPATIBLE_FLAGS_PER_VARIANT["stress_concurrent_inlining"],
   "--stress-flush-bytecode": ["--no-stress-flush-bytecode"],
-  "--future": ["--no-turbo-direct-heap-access"],
   "--stress-incremental-marking": INCOMPATIBLE_FLAGS_PER_VARIANT["stress_incremental_marking"],
 }
 
diff --git a/chromium/v8/tools/testrunner/outproc/message.py b/chromium/v8/tools/testrunner/outproc/message.py
index c253b6f8e06..c301529eb7d 100644
--- a/chromium/v8/tools/testrunner/outproc/message.py
+++ b/chromium/v8/tools/testrunner/outproc/message.py
@@ -9,9 +9,11 @@ import re
 from . import base
 
 
-class OutProc(base.OutProc):
-  def __init__(self, expected_outcomes, basepath, expected_fail):
-    super(OutProc, self).__init__(expected_outcomes)
+class OutProc(base.ExpectedOutProc):
+  def __init__(self, expected_outcomes, basepath, expected_fail,
+               expected_filename, regenerate_expected_files):
+    super(OutProc, self).__init__(expected_outcomes, expected_filename,
+                                  regenerate_expected_files)
     self._basepath = basepath
     self._expected_fail = expected_fail
 
diff --git a/chromium/v8/tools/testrunner/standard_runner.py b/chromium/v8/tools/testrunner/standard_runner.py
index f3551d01b88..94c25766824 100755
--- a/chromium/v8/tools/testrunner/standard_runner.py
+++ b/chromium/v8/tools/testrunner/standard_runner.py
@@ -46,7 +46,7 @@ VARIANT_ALIASES = {
   'exhaustive': MORE_VARIANTS + VARIANTS,
   # Additional variants, run on a subset of bots.
   'extra': ['nooptimization', 'future', 'no_wasm_traps', 'turboprop',
-            'instruction_scheduling', 'turboprop_as_toptier'],
+            'instruction_scheduling', 'always_sparkplug'],
 }
 
 # Extra flags passed to all tests using the standard test runner.
diff --git a/chromium/v8/tools/testrunner/testproc/fuzzer.py b/chromium/v8/tools/testrunner/testproc/fuzzer.py
index 965ba23d04f..1237da56b2e 100644
--- a/chromium/v8/tools/testrunner/testproc/fuzzer.py
+++ b/chromium/v8/tools/testrunner/testproc/fuzzer.py
@@ -43,6 +43,7 @@ EXTRA_FLAGS = [
   (0.1, '--regexp-tier-up-ticks=10'),
   (0.1, '--regexp-tier-up-ticks=100'),
   (0.1, '--stress-background-compile'),
+  (0.1, '--stress-concurrent-inlining'),
   (0.1, '--stress-lazy-source-positions'),
   (0.1, '--stress-wasm-code-gc'),
   (0.1, '--turbo-instruction-scheduling'),
diff --git a/chromium/v8/tools/tickprocessor-driver.mjs b/chromium/v8/tools/tickprocessor-driver.mjs
index e7020e388d2..c0507bfffee 100644
--- a/chromium/v8/tools/tickprocessor-driver.mjs
+++ b/chromium/v8/tools/tickprocessor-driver.mjs
@@ -73,6 +73,7 @@ const tickProcessor = new TickProcessor(
   params.separateBytecodes,
   params.separateBuiltins,
   params.separateStubs,
+  params.separateBaselineHandlers,
   params.callGraphSize,
   params.ignoreUnknown,
   params.stateFilter,
@@ -85,4 +86,9 @@ const tickProcessor = new TickProcessor(
   params.runtimeTimerFilter,
   params.preprocessJson);
 tickProcessor.processLogFile(params.logFileName);
-tickProcessor.printStatistics();
+
+if (params.serializeVMSymbols) {
+  tickProcessor.printVMSymbols();
+} else {
+  tickProcessor.printStatistics();
+}
diff --git a/chromium/v8/tools/tickprocessor.mjs b/chromium/v8/tools/tickprocessor.mjs
index 1ad67e22c0d..8b59e573352 100644
--- a/chromium/v8/tools/tickprocessor.mjs
+++ b/chromium/v8/tools/tickprocessor.mjs
@@ -35,10 +35,12 @@ class V8Profile extends Profile {
   static IC_RE =
       /^(LoadGlobalIC: )|(Handler: )|(?:CallIC|LoadIC|StoreIC)|(?:Builtin: (?:Keyed)?(?:Load|Store)IC_)/;
   static BYTECODES_RE = /^(BytecodeHandler: )/;
+  static BASELINE_HANDLERS_RE = /^(Builtin: .*Baseline.*)/;
   static BUILTINS_RE = /^(Builtin: )/;
   static STUBS_RE = /^(Stub: )/;
 
-  constructor(separateIc, separateBytecodes, separateBuiltins, separateStubs) {
+  constructor(separateIc, separateBytecodes, separateBuiltins, separateStubs,
+        separateBaselineHandlers) {
     super();
     const regexps = [];
     if (!separateIc) regexps.push(V8Profile.IC_RE);
@@ -46,7 +48,7 @@ class V8Profile extends Profile {
     if (!separateBuiltins) regexps.push(V8Profile.BUILTINS_RE);
     if (!separateStubs) regexps.push(V8Profile.STUBS_RE);
     if (regexps.length > 0) {
-      this.skipThisFunction = function (name) {
+      this.skipThisFunction = function(name) {
         for (let i = 0; i < regexps.length; i++) {
           if (regexps[i].test(name)) return true;
         }
@@ -64,7 +66,7 @@ export function readFile(fileName) {
   try {
     return read(fileName);
   } catch (e) {
-    printErr(`${fileName}: ${e.message || e}`);
+    printErr(`file="${fileName}": ${e.message || e}`);
     throw e;
   }
 }
@@ -77,6 +79,7 @@ export class TickProcessor extends LogReader {
     separateBytecodes,
     separateBuiltins,
     separateStubs,
+    separateBaselineHandlers,
     callGraphSize,
     ignoreUnknown,
     stateFilter,
@@ -211,7 +214,7 @@ export class TickProcessor extends LogReader {
       this.profile_ = new JsonProfile();
     } else {
       this.profile_ = new V8Profile(separateIc, separateBytecodes,
-        separateBuiltins, separateStubs);
+        separateBuiltins, separateStubs, separateBaselineHandlers);
     }
     this.codeTypes_ = {};
     // Count each tick as a time unit.
@@ -228,6 +231,7 @@ export class TickProcessor extends LogReader {
     GC: 1,
     PARSER: 2,
     BYTECODE_COMPILER: 3,
+    // TODO(cbruni): add BASELINE_COMPILER
     COMPILER: 4,
     OTHER: 5,
     EXTERNAL: 6,
@@ -285,7 +289,7 @@ export class TickProcessor extends LogReader {
   processSharedLibrary(name, startAddr, endAddr, aslrSlide) {
     const entry = this.profile_.addLibrary(name, startAddr, endAddr, aslrSlide);
     this.setCodeType(entry.getName(), 'SHARED_LIB');
-    const libFuncs = this.cppEntriesProvider_.parseVmSymbols(
+    this.cppEntriesProvider_.parseVmSymbols(
       name, startAddr, endAddr, aslrSlide, (fName, fStart, fEnd) => {
         this.profile_.addStaticCode(fName, fStart, fEnd);
         this.setCodeType(fName, 'CPP');
@@ -409,6 +413,11 @@ export class TickProcessor extends LogReader {
     this.generation_++;
   }
 
+  printVMSymbols() {
+    console.log(
+      JSON.stringify(this.profile_.serializeVMSymbols()));
+  }
+
   printStatistics() {
     if (this.preprocessJson) {
       this.profile_.writeJson();
@@ -854,6 +863,8 @@ export class ArgumentsProcessor extends BaseArgumentsProcessor {
         'Separate Builtin entries'],
       '--separate-stubs': ['separateStubs', parseBool,
         'Separate Stub entries'],
+      '--separate-baseline-handlers': ['separateBaselineHandlers', parseBool,
+        'Separate Baseline Handler entries'],
       '--unix': ['platform', 'unix',
         'Specify that we are running on *nix platform'],
       '--windows': ['platform', 'windows',
@@ -880,6 +891,8 @@ export class ArgumentsProcessor extends BaseArgumentsProcessor {
         'Ignore ticks outside pairs of Date.now() calls'],
       '--only-summary': ['onlySummary', true,
         'Print only tick summary, exclude other information'],
+      '--serialize-vm-symbols': ['serializeVMSymbols', true,
+        'Print all C++ symbols and library addresses as JSON data'],
       '--preprocess': ['preprocessJson', true,
         'Preprocess for consumption with web interface']
     };
@@ -903,6 +916,7 @@ export class ArgumentsProcessor extends BaseArgumentsProcessor {
       separateBytecodes: false,
       separateBuiltins: true,
       separateStubs: true,
+      separateBaselineHandlers: false,
       preprocessJson: null,
       targetRootFS: '',
       nm: 'nm',
@@ -913,6 +927,7 @@ export class ArgumentsProcessor extends BaseArgumentsProcessor {
       pairwiseTimedRange: false,
       onlySummary: false,
       runtimeTimerFilter: null,
+      serializeVMSymbols: false,
     };
   }
 }
diff --git a/chromium/v8/tools/ubsan/blacklist.txt b/chromium/v8/tools/ubsan/ignorelist.txt
index ea4e79bf522..4e476abe492 100644
--- a/chromium/v8/tools/ubsan/blacklist.txt
+++ b/chromium/v8/tools/ubsan/ignorelist.txt
@@ -1,5 +1,5 @@
 #############################################################################
-# UBSan blacklist.
+# UBSan ignorelist.
 
 # Bug 8735: PropertyCallbackInfo<void> vs PropertyCallbackInfo<T>.
 fun:*v8*internal*PropertyCallbackArguments*CallAccessorSetter*
diff --git a/chromium/v8/tools/ubsan/vptr_blacklist.txt b/chromium/v8/tools/ubsan/vptr_ignorelist.txt
index ccad5b10615..26c30ed02d5 100644
--- a/chromium/v8/tools/ubsan/vptr_blacklist.txt
+++ b/chromium/v8/tools/ubsan/vptr_ignorelist.txt
@@ -1,9 +1,9 @@
 #############################################################################
-# UBSan vptr blacklist.
-# Function and type based blacklisting use a mangled name, and it is especially
+# UBSan vptr ignorelist.
+# Function and type based ignorelisting use a mangled name, and it is especially
 # tricky to represent C++ types. For now, any possible changes by name manglings
 # are simply represented as wildcard expressions of regexp, and thus it might be
-# over-blacklisted.
+# over-ignorelisted.
 
 #############################################################################
 # UBsan goes into an infinite recursion when __dynamic_cast instrumented with
diff --git a/chromium/v8/tools/unittests/run_tests_test.py b/chromium/v8/tools/unittests/run_tests_test.py
index f174a239bf2..ae3833abc81 100755
--- a/chromium/v8/tools/unittests/run_tests_test.py
+++ b/chromium/v8/tools/unittests/run_tests_test.py
@@ -334,7 +334,8 @@ class SystemTest(unittest.TestCase):
           is_msan=True, is_tsan=True, is_ubsan_vptr=True, target_cpu='x86',
           v8_enable_i18n_support=False, v8_target_cpu='x86',
           v8_enable_verify_csa=False, v8_enable_lite_mode=False,
-          v8_enable_pointer_compression=False)
+          v8_enable_pointer_compression=False,
+          v8_enable_pointer_compression_shared_cage=False)
       result = run_tests(
           basedir,
           '--progress=verbose',
diff --git a/chromium/v8/tools/v8_presubmit.py b/chromium/v8/tools/v8_presubmit.py
index db008aabf17..f4212794513 100755
--- a/chromium/v8/tools/v8_presubmit.py
+++ b/chromium/v8/tools/v8_presubmit.py
@@ -63,6 +63,8 @@ from testrunner.local import utils
 # runtime/references: As of May 2020 the C++ style guide suggests using
 #   references for out parameters, see
 #   https://google.github.io/styleguide/cppguide.html#Inputs_and_Outputs.
+# whitespace/braces: Doesn't handle {}-initialization for custom types
+#   well; also should be subsumed by clang-format.
 
 LINT_RULES = """
 -build/header_guard
@@ -70,6 +72,7 @@ LINT_RULES = """
 -readability/fn_size
 -readability/multiline_comment
 -runtime/references
+-whitespace/braces
 -whitespace/comments
 """.split()
 
diff --git a/chromium/v8/tools/v8heapconst.py b/chromium/v8/tools/v8heapconst.py
index f0cc6481a88..c28123dcec9 100644
--- a/chromium/v8/tools/v8heapconst.py
+++ b/chromium/v8/tools/v8heapconst.py
@@ -32,126 +32,128 @@ INSTANCE_TYPES = {
   68: "ABSTRACT_INTERNAL_CLASS_SUBCLASS1_TYPE",
   69: "ABSTRACT_INTERNAL_CLASS_SUBCLASS2_TYPE",
   70: "FOREIGN_TYPE",
-  71: "WASM_TYPE_INFO_TYPE",
-  72: "PROMISE_FULFILL_REACTION_JOB_TASK_TYPE",
-  73: "PROMISE_REJECT_REACTION_JOB_TASK_TYPE",
-  74: "CALLABLE_TASK_TYPE",
-  75: "CALLBACK_TASK_TYPE",
-  76: "PROMISE_RESOLVE_THENABLE_JOB_TASK_TYPE",
-  77: "LOAD_HANDLER_TYPE",
-  78: "STORE_HANDLER_TYPE",
-  79: "FUNCTION_TEMPLATE_INFO_TYPE",
-  80: "OBJECT_TEMPLATE_INFO_TYPE",
-  81: "ACCESS_CHECK_INFO_TYPE",
-  82: "ACCESSOR_INFO_TYPE",
-  83: "ACCESSOR_PAIR_TYPE",
-  84: "ALIASED_ARGUMENTS_ENTRY_TYPE",
-  85: "ALLOCATION_MEMENTO_TYPE",
-  86: "ALLOCATION_SITE_TYPE",
-  87: "ARRAY_BOILERPLATE_DESCRIPTION_TYPE",
-  88: "ASM_WASM_DATA_TYPE",
-  89: "ASYNC_GENERATOR_REQUEST_TYPE",
-  90: "BASELINE_DATA_TYPE",
-  91: "BREAK_POINT_TYPE",
-  92: "BREAK_POINT_INFO_TYPE",
-  93: "CACHED_TEMPLATE_OBJECT_TYPE",
-  94: "CALL_HANDLER_INFO_TYPE",
-  95: "CLASS_POSITIONS_TYPE",
-  96: "DEBUG_INFO_TYPE",
-  97: "ENUM_CACHE_TYPE",
-  98: "FEEDBACK_CELL_TYPE",
-  99: "FUNCTION_TEMPLATE_RARE_DATA_TYPE",
-  100: "INTERCEPTOR_INFO_TYPE",
-  101: "INTERPRETER_DATA_TYPE",
-  102: "MODULE_REQUEST_TYPE",
-  103: "PROMISE_CAPABILITY_TYPE",
-  104: "PROMISE_REACTION_TYPE",
-  105: "PROPERTY_DESCRIPTOR_OBJECT_TYPE",
-  106: "PROTOTYPE_INFO_TYPE",
-  107: "REG_EXP_BOILERPLATE_DESCRIPTION_TYPE",
-  108: "SCRIPT_TYPE",
-  109: "SOURCE_TEXT_MODULE_INFO_ENTRY_TYPE",
-  110: "STACK_FRAME_INFO_TYPE",
-  111: "TEMPLATE_OBJECT_DESCRIPTION_TYPE",
-  112: "TUPLE2_TYPE",
-  113: "WASM_EXCEPTION_TAG_TYPE",
-  114: "WASM_EXPORTED_FUNCTION_DATA_TYPE",
-  115: "WASM_INDIRECT_FUNCTION_TABLE_TYPE",
-  116: "WASM_JS_FUNCTION_DATA_TYPE",
-  117: "FIXED_ARRAY_TYPE",
-  118: "HASH_TABLE_TYPE",
-  119: "EPHEMERON_HASH_TABLE_TYPE",
-  120: "GLOBAL_DICTIONARY_TYPE",
-  121: "NAME_DICTIONARY_TYPE",
-  122: "NUMBER_DICTIONARY_TYPE",
-  123: "ORDERED_HASH_MAP_TYPE",
-  124: "ORDERED_HASH_SET_TYPE",
-  125: "ORDERED_NAME_DICTIONARY_TYPE",
-  126: "SIMPLE_NUMBER_DICTIONARY_TYPE",
-  127: "CLOSURE_FEEDBACK_CELL_ARRAY_TYPE",
-  128: "OBJECT_BOILERPLATE_DESCRIPTION_TYPE",
-  129: "SCRIPT_CONTEXT_TABLE_TYPE",
-  130: "BYTE_ARRAY_TYPE",
-  131: "BYTECODE_ARRAY_TYPE",
-  132: "FIXED_DOUBLE_ARRAY_TYPE",
-  133: "INTERNAL_CLASS_WITH_SMI_ELEMENTS_TYPE",
-  134: "SLOPPY_ARGUMENTS_ELEMENTS_TYPE",
-  135: "AWAIT_CONTEXT_TYPE",
-  136: "BLOCK_CONTEXT_TYPE",
-  137: "CATCH_CONTEXT_TYPE",
-  138: "DEBUG_EVALUATE_CONTEXT_TYPE",
-  139: "EVAL_CONTEXT_TYPE",
-  140: "FUNCTION_CONTEXT_TYPE",
-  141: "MODULE_CONTEXT_TYPE",
-  142: "NATIVE_CONTEXT_TYPE",
-  143: "SCRIPT_CONTEXT_TYPE",
-  144: "WITH_CONTEXT_TYPE",
-  145: "EXPORTED_SUB_CLASS_BASE_TYPE",
-  146: "EXPORTED_SUB_CLASS_TYPE",
-  147: "EXPORTED_SUB_CLASS2_TYPE",
-  148: "SMALL_ORDERED_HASH_MAP_TYPE",
-  149: "SMALL_ORDERED_HASH_SET_TYPE",
-  150: "SMALL_ORDERED_NAME_DICTIONARY_TYPE",
-  151: "DESCRIPTOR_ARRAY_TYPE",
-  152: "STRONG_DESCRIPTOR_ARRAY_TYPE",
-  153: "SOURCE_TEXT_MODULE_TYPE",
-  154: "SYNTHETIC_MODULE_TYPE",
-  155: "UNCOMPILED_DATA_WITH_PREPARSE_DATA_TYPE",
-  156: "UNCOMPILED_DATA_WITHOUT_PREPARSE_DATA_TYPE",
-  157: "WEAK_FIXED_ARRAY_TYPE",
-  158: "TRANSITION_ARRAY_TYPE",
-  159: "CELL_TYPE",
-  160: "CODE_TYPE",
-  161: "CODE_DATA_CONTAINER_TYPE",
-  162: "COVERAGE_INFO_TYPE",
-  163: "EMBEDDER_DATA_ARRAY_TYPE",
-  164: "FEEDBACK_METADATA_TYPE",
-  165: "FEEDBACK_VECTOR_TYPE",
-  166: "FILLER_TYPE",
-  167: "FREE_SPACE_TYPE",
-  168: "INTERNAL_CLASS_TYPE",
-  169: "INTERNAL_CLASS_WITH_STRUCT_ELEMENTS_TYPE",
-  170: "MAP_TYPE",
-  171: "ON_HEAP_BASIC_BLOCK_PROFILER_DATA_TYPE",
-  172: "PREPARSE_DATA_TYPE",
-  173: "PROPERTY_ARRAY_TYPE",
-  174: "PROPERTY_CELL_TYPE",
-  175: "SCOPE_INFO_TYPE",
-  176: "SHARED_FUNCTION_INFO_TYPE",
-  177: "SMI_BOX_TYPE",
-  178: "SMI_PAIR_TYPE",
-  179: "SORT_STATE_TYPE",
-  180: "SWISS_NAME_DICTIONARY_TYPE",
-  181: "WASM_ARRAY_TYPE",
-  182: "WASM_CAPI_FUNCTION_DATA_TYPE",
-  183: "WASM_STRUCT_TYPE",
-  184: "WEAK_ARRAY_LIST_TYPE",
-  185: "WEAK_CELL_TYPE",
-  186: "JS_PROXY_TYPE",
+  71: "WASM_FUNCTION_DATA_TYPE",
+  72: "WASM_EXPORTED_FUNCTION_DATA_TYPE",
+  73: "WASM_JS_FUNCTION_DATA_TYPE",
+  74: "WASM_TYPE_INFO_TYPE",
+  75: "PROMISE_FULFILL_REACTION_JOB_TASK_TYPE",
+  76: "PROMISE_REJECT_REACTION_JOB_TASK_TYPE",
+  77: "CALLABLE_TASK_TYPE",
+  78: "CALLBACK_TASK_TYPE",
+  79: "PROMISE_RESOLVE_THENABLE_JOB_TASK_TYPE",
+  80: "LOAD_HANDLER_TYPE",
+  81: "STORE_HANDLER_TYPE",
+  82: "FUNCTION_TEMPLATE_INFO_TYPE",
+  83: "OBJECT_TEMPLATE_INFO_TYPE",
+  84: "ACCESS_CHECK_INFO_TYPE",
+  85: "ACCESSOR_INFO_TYPE",
+  86: "ACCESSOR_PAIR_TYPE",
+  87: "ALIASED_ARGUMENTS_ENTRY_TYPE",
+  88: "ALLOCATION_MEMENTO_TYPE",
+  89: "ALLOCATION_SITE_TYPE",
+  90: "ARRAY_BOILERPLATE_DESCRIPTION_TYPE",
+  91: "ASM_WASM_DATA_TYPE",
+  92: "ASYNC_GENERATOR_REQUEST_TYPE",
+  93: "BASELINE_DATA_TYPE",
+  94: "BREAK_POINT_TYPE",
+  95: "BREAK_POINT_INFO_TYPE",
+  96: "CACHED_TEMPLATE_OBJECT_TYPE",
+  97: "CALL_HANDLER_INFO_TYPE",
+  98: "CLASS_POSITIONS_TYPE",
+  99: "DEBUG_INFO_TYPE",
+  100: "ENUM_CACHE_TYPE",
+  101: "FEEDBACK_CELL_TYPE",
+  102: "FUNCTION_TEMPLATE_RARE_DATA_TYPE",
+  103: "INTERCEPTOR_INFO_TYPE",
+  104: "INTERPRETER_DATA_TYPE",
+  105: "MODULE_REQUEST_TYPE",
+  106: "PROMISE_CAPABILITY_TYPE",
+  107: "PROMISE_REACTION_TYPE",
+  108: "PROPERTY_DESCRIPTOR_OBJECT_TYPE",
+  109: "PROTOTYPE_INFO_TYPE",
+  110: "REG_EXP_BOILERPLATE_DESCRIPTION_TYPE",
+  111: "SCRIPT_TYPE",
+  112: "SOURCE_TEXT_MODULE_INFO_ENTRY_TYPE",
+  113: "STACK_FRAME_INFO_TYPE",
+  114: "TEMPLATE_OBJECT_DESCRIPTION_TYPE",
+  115: "TUPLE2_TYPE",
+  116: "WASM_EXCEPTION_TAG_TYPE",
+  117: "WASM_INDIRECT_FUNCTION_TABLE_TYPE",
+  118: "FIXED_ARRAY_TYPE",
+  119: "HASH_TABLE_TYPE",
+  120: "EPHEMERON_HASH_TABLE_TYPE",
+  121: "GLOBAL_DICTIONARY_TYPE",
+  122: "NAME_DICTIONARY_TYPE",
+  123: "NUMBER_DICTIONARY_TYPE",
+  124: "ORDERED_HASH_MAP_TYPE",
+  125: "ORDERED_HASH_SET_TYPE",
+  126: "ORDERED_NAME_DICTIONARY_TYPE",
+  127: "SIMPLE_NUMBER_DICTIONARY_TYPE",
+  128: "CLOSURE_FEEDBACK_CELL_ARRAY_TYPE",
+  129: "OBJECT_BOILERPLATE_DESCRIPTION_TYPE",
+  130: "SCRIPT_CONTEXT_TABLE_TYPE",
+  131: "BYTE_ARRAY_TYPE",
+  132: "BYTECODE_ARRAY_TYPE",
+  133: "FIXED_DOUBLE_ARRAY_TYPE",
+  134: "INTERNAL_CLASS_WITH_SMI_ELEMENTS_TYPE",
+  135: "SLOPPY_ARGUMENTS_ELEMENTS_TYPE",
+  136: "AWAIT_CONTEXT_TYPE",
+  137: "BLOCK_CONTEXT_TYPE",
+  138: "CATCH_CONTEXT_TYPE",
+  139: "DEBUG_EVALUATE_CONTEXT_TYPE",
+  140: "EVAL_CONTEXT_TYPE",
+  141: "FUNCTION_CONTEXT_TYPE",
+  142: "MODULE_CONTEXT_TYPE",
+  143: "NATIVE_CONTEXT_TYPE",
+  144: "SCRIPT_CONTEXT_TYPE",
+  145: "WITH_CONTEXT_TYPE",
+  146: "EXPORTED_SUB_CLASS_BASE_TYPE",
+  147: "EXPORTED_SUB_CLASS_TYPE",
+  148: "EXPORTED_SUB_CLASS2_TYPE",
+  149: "SMALL_ORDERED_HASH_MAP_TYPE",
+  150: "SMALL_ORDERED_HASH_SET_TYPE",
+  151: "SMALL_ORDERED_NAME_DICTIONARY_TYPE",
+  152: "DESCRIPTOR_ARRAY_TYPE",
+  153: "STRONG_DESCRIPTOR_ARRAY_TYPE",
+  154: "SOURCE_TEXT_MODULE_TYPE",
+  155: "SYNTHETIC_MODULE_TYPE",
+  156: "UNCOMPILED_DATA_WITH_PREPARSE_DATA_TYPE",
+  157: "UNCOMPILED_DATA_WITHOUT_PREPARSE_DATA_TYPE",
+  158: "WEAK_FIXED_ARRAY_TYPE",
+  159: "TRANSITION_ARRAY_TYPE",
+  160: "CELL_TYPE",
+  161: "CODE_TYPE",
+  162: "CODE_DATA_CONTAINER_TYPE",
+  163: "COVERAGE_INFO_TYPE",
+  164: "EMBEDDER_DATA_ARRAY_TYPE",
+  165: "FEEDBACK_METADATA_TYPE",
+  166: "FEEDBACK_VECTOR_TYPE",
+  167: "FILLER_TYPE",
+  168: "FREE_SPACE_TYPE",
+  169: "INTERNAL_CLASS_TYPE",
+  170: "INTERNAL_CLASS_WITH_STRUCT_ELEMENTS_TYPE",
+  171: "MAP_TYPE",
+  172: "MEGA_DOM_HANDLER_TYPE",
+  173: "ON_HEAP_BASIC_BLOCK_PROFILER_DATA_TYPE",
+  174: "PREPARSE_DATA_TYPE",
+  175: "PROPERTY_ARRAY_TYPE",
+  176: "PROPERTY_CELL_TYPE",
+  177: "SCOPE_INFO_TYPE",
+  178: "SHARED_FUNCTION_INFO_TYPE",
+  179: "SMI_BOX_TYPE",
+  180: "SMI_PAIR_TYPE",
+  181: "SORT_STATE_TYPE",
+  182: "SWISS_NAME_DICTIONARY_TYPE",
+  183: "WASM_ARRAY_TYPE",
+  184: "WASM_CAPI_FUNCTION_DATA_TYPE",
+  185: "WASM_STRUCT_TYPE",
+  186: "WEAK_ARRAY_LIST_TYPE",
+  187: "WEAK_CELL_TYPE",
+  188: "JS_PROXY_TYPE",
   1057: "JS_OBJECT_TYPE",
-  187: "JS_GLOBAL_OBJECT_TYPE",
-  188: "JS_GLOBAL_PROXY_TYPE",
-  189: "JS_MODULE_NAMESPACE_TYPE",
+  189: "JS_GLOBAL_OBJECT_TYPE",
+  190: "JS_GLOBAL_PROXY_TYPE",
+  191: "JS_MODULE_NAMESPACE_TYPE",
   1040: "JS_SPECIAL_API_OBJECT_TYPE",
   1041: "JS_PRIMITIVE_WRAPPER_TYPE",
   1042: "JS_ARRAY_ITERATOR_PROTOTYPE_TYPE",
@@ -233,159 +235,160 @@ INSTANCE_TYPES = {
 
 # List of known V8 maps.
 KNOWN_MAPS = {
-  ("read_only_space", 0x02119): (170, "MetaMap"),
+  ("read_only_space", 0x02119): (171, "MetaMap"),
   ("read_only_space", 0x02141): (67, "NullMap"),
-  ("read_only_space", 0x02169): (152, "StrongDescriptorArrayMap"),
-  ("read_only_space", 0x02191): (157, "WeakFixedArrayMap"),
-  ("read_only_space", 0x021d1): (97, "EnumCacheMap"),
-  ("read_only_space", 0x02205): (117, "FixedArrayMap"),
+  ("read_only_space", 0x02169): (153, "StrongDescriptorArrayMap"),
+  ("read_only_space", 0x02191): (158, "WeakFixedArrayMap"),
+  ("read_only_space", 0x021d1): (100, "EnumCacheMap"),
+  ("read_only_space", 0x02205): (118, "FixedArrayMap"),
   ("read_only_space", 0x02251): (8, "OneByteInternalizedStringMap"),
-  ("read_only_space", 0x0229d): (167, "FreeSpaceMap"),
-  ("read_only_space", 0x022c5): (166, "OnePointerFillerMap"),
-  ("read_only_space", 0x022ed): (166, "TwoPointerFillerMap"),
+  ("read_only_space", 0x0229d): (168, "FreeSpaceMap"),
+  ("read_only_space", 0x022c5): (167, "OnePointerFillerMap"),
+  ("read_only_space", 0x022ed): (167, "TwoPointerFillerMap"),
   ("read_only_space", 0x02315): (67, "UninitializedMap"),
   ("read_only_space", 0x0238d): (67, "UndefinedMap"),
   ("read_only_space", 0x023d1): (66, "HeapNumberMap"),
   ("read_only_space", 0x02405): (67, "TheHoleMap"),
   ("read_only_space", 0x02465): (67, "BooleanMap"),
-  ("read_only_space", 0x02509): (130, "ByteArrayMap"),
-  ("read_only_space", 0x02531): (117, "FixedCOWArrayMap"),
-  ("read_only_space", 0x02559): (118, "HashTableMap"),
+  ("read_only_space", 0x02509): (131, "ByteArrayMap"),
+  ("read_only_space", 0x02531): (118, "FixedCOWArrayMap"),
+  ("read_only_space", 0x02559): (119, "HashTableMap"),
   ("read_only_space", 0x02581): (64, "SymbolMap"),
   ("read_only_space", 0x025a9): (40, "OneByteStringMap"),
-  ("read_only_space", 0x025d1): (175, "ScopeInfoMap"),
-  ("read_only_space", 0x025f9): (176, "SharedFunctionInfoMap"),
-  ("read_only_space", 0x02621): (160, "CodeMap"),
-  ("read_only_space", 0x02649): (159, "CellMap"),
-  ("read_only_space", 0x02671): (174, "GlobalPropertyCellMap"),
+  ("read_only_space", 0x025d1): (177, "ScopeInfoMap"),
+  ("read_only_space", 0x025f9): (178, "SharedFunctionInfoMap"),
+  ("read_only_space", 0x02621): (161, "CodeMap"),
+  ("read_only_space", 0x02649): (160, "CellMap"),
+  ("read_only_space", 0x02671): (176, "GlobalPropertyCellMap"),
   ("read_only_space", 0x02699): (70, "ForeignMap"),
-  ("read_only_space", 0x026c1): (158, "TransitionArrayMap"),
+  ("read_only_space", 0x026c1): (159, "TransitionArrayMap"),
   ("read_only_space", 0x026e9): (45, "ThinOneByteStringMap"),
-  ("read_only_space", 0x02711): (165, "FeedbackVectorMap"),
+  ("read_only_space", 0x02711): (166, "FeedbackVectorMap"),
   ("read_only_space", 0x02749): (67, "ArgumentsMarkerMap"),
   ("read_only_space", 0x027a9): (67, "ExceptionMap"),
   ("read_only_space", 0x02805): (67, "TerminationExceptionMap"),
   ("read_only_space", 0x0286d): (67, "OptimizedOutMap"),
   ("read_only_space", 0x028cd): (67, "StaleRegisterMap"),
-  ("read_only_space", 0x0292d): (129, "ScriptContextTableMap"),
-  ("read_only_space", 0x02955): (127, "ClosureFeedbackCellArrayMap"),
-  ("read_only_space", 0x0297d): (164, "FeedbackMetadataArrayMap"),
-  ("read_only_space", 0x029a5): (117, "ArrayListMap"),
+  ("read_only_space", 0x0292d): (130, "ScriptContextTableMap"),
+  ("read_only_space", 0x02955): (128, "ClosureFeedbackCellArrayMap"),
+  ("read_only_space", 0x0297d): (165, "FeedbackMetadataArrayMap"),
+  ("read_only_space", 0x029a5): (118, "ArrayListMap"),
   ("read_only_space", 0x029cd): (65, "BigIntMap"),
-  ("read_only_space", 0x029f5): (128, "ObjectBoilerplateDescriptionMap"),
-  ("read_only_space", 0x02a1d): (131, "BytecodeArrayMap"),
-  ("read_only_space", 0x02a45): (161, "CodeDataContainerMap"),
-  ("read_only_space", 0x02a6d): (162, "CoverageInfoMap"),
-  ("read_only_space", 0x02a95): (132, "FixedDoubleArrayMap"),
-  ("read_only_space", 0x02abd): (120, "GlobalDictionaryMap"),
-  ("read_only_space", 0x02ae5): (98, "ManyClosuresCellMap"),
-  ("read_only_space", 0x02b0d): (117, "ModuleInfoMap"),
-  ("read_only_space", 0x02b35): (121, "NameDictionaryMap"),
-  ("read_only_space", 0x02b5d): (98, "NoClosuresCellMap"),
-  ("read_only_space", 0x02b85): (122, "NumberDictionaryMap"),
-  ("read_only_space", 0x02bad): (98, "OneClosureCellMap"),
-  ("read_only_space", 0x02bd5): (123, "OrderedHashMapMap"),
-  ("read_only_space", 0x02bfd): (124, "OrderedHashSetMap"),
-  ("read_only_space", 0x02c25): (125, "OrderedNameDictionaryMap"),
-  ("read_only_space", 0x02c4d): (172, "PreparseDataMap"),
-  ("read_only_space", 0x02c75): (173, "PropertyArrayMap"),
-  ("read_only_space", 0x02c9d): (94, "SideEffectCallHandlerInfoMap"),
-  ("read_only_space", 0x02cc5): (94, "SideEffectFreeCallHandlerInfoMap"),
-  ("read_only_space", 0x02ced): (94, "NextCallSideEffectFreeCallHandlerInfoMap"),
-  ("read_only_space", 0x02d15): (126, "SimpleNumberDictionaryMap"),
-  ("read_only_space", 0x02d3d): (148, "SmallOrderedHashMapMap"),
-  ("read_only_space", 0x02d65): (149, "SmallOrderedHashSetMap"),
-  ("read_only_space", 0x02d8d): (150, "SmallOrderedNameDictionaryMap"),
-  ("read_only_space", 0x02db5): (153, "SourceTextModuleMap"),
-  ("read_only_space", 0x02ddd): (180, "SwissNameDictionaryMap"),
-  ("read_only_space", 0x02e05): (154, "SyntheticModuleMap"),
-  ("read_only_space", 0x02e2d): (71, "WasmTypeInfoMap"),
-  ("read_only_space", 0x02e55): (184, "WeakArrayListMap"),
-  ("read_only_space", 0x02e7d): (119, "EphemeronHashTableMap"),
-  ("read_only_space", 0x02ea5): (163, "EmbedderDataArrayMap"),
-  ("read_only_space", 0x02ecd): (185, "WeakCellMap"),
-  ("read_only_space", 0x02ef5): (32, "StringMap"),
-  ("read_only_space", 0x02f1d): (41, "ConsOneByteStringMap"),
-  ("read_only_space", 0x02f45): (33, "ConsStringMap"),
-  ("read_only_space", 0x02f6d): (37, "ThinStringMap"),
-  ("read_only_space", 0x02f95): (35, "SlicedStringMap"),
-  ("read_only_space", 0x02fbd): (43, "SlicedOneByteStringMap"),
-  ("read_only_space", 0x02fe5): (34, "ExternalStringMap"),
-  ("read_only_space", 0x0300d): (42, "ExternalOneByteStringMap"),
-  ("read_only_space", 0x03035): (50, "UncachedExternalStringMap"),
-  ("read_only_space", 0x0305d): (0, "InternalizedStringMap"),
-  ("read_only_space", 0x03085): (2, "ExternalInternalizedStringMap"),
-  ("read_only_space", 0x030ad): (10, "ExternalOneByteInternalizedStringMap"),
-  ("read_only_space", 0x030d5): (18, "UncachedExternalInternalizedStringMap"),
-  ("read_only_space", 0x030fd): (26, "UncachedExternalOneByteInternalizedStringMap"),
-  ("read_only_space", 0x03125): (58, "UncachedExternalOneByteStringMap"),
-  ("read_only_space", 0x0314d): (67, "SelfReferenceMarkerMap"),
-  ("read_only_space", 0x03175): (67, "BasicBlockCountersMarkerMap"),
-  ("read_only_space", 0x031b9): (87, "ArrayBoilerplateDescriptionMap"),
-  ("read_only_space", 0x032b9): (100, "InterceptorInfoMap"),
-  ("read_only_space", 0x05401): (72, "PromiseFulfillReactionJobTaskMap"),
-  ("read_only_space", 0x05429): (73, "PromiseRejectReactionJobTaskMap"),
-  ("read_only_space", 0x05451): (74, "CallableTaskMap"),
-  ("read_only_space", 0x05479): (75, "CallbackTaskMap"),
-  ("read_only_space", 0x054a1): (76, "PromiseResolveThenableJobTaskMap"),
-  ("read_only_space", 0x054c9): (79, "FunctionTemplateInfoMap"),
-  ("read_only_space", 0x054f1): (80, "ObjectTemplateInfoMap"),
-  ("read_only_space", 0x05519): (81, "AccessCheckInfoMap"),
-  ("read_only_space", 0x05541): (82, "AccessorInfoMap"),
-  ("read_only_space", 0x05569): (83, "AccessorPairMap"),
-  ("read_only_space", 0x05591): (84, "AliasedArgumentsEntryMap"),
-  ("read_only_space", 0x055b9): (85, "AllocationMementoMap"),
-  ("read_only_space", 0x055e1): (88, "AsmWasmDataMap"),
-  ("read_only_space", 0x05609): (89, "AsyncGeneratorRequestMap"),
-  ("read_only_space", 0x05631): (90, "BaselineDataMap"),
-  ("read_only_space", 0x05659): (91, "BreakPointMap"),
-  ("read_only_space", 0x05681): (92, "BreakPointInfoMap"),
-  ("read_only_space", 0x056a9): (93, "CachedTemplateObjectMap"),
-  ("read_only_space", 0x056d1): (95, "ClassPositionsMap"),
-  ("read_only_space", 0x056f9): (96, "DebugInfoMap"),
-  ("read_only_space", 0x05721): (99, "FunctionTemplateRareDataMap"),
-  ("read_only_space", 0x05749): (101, "InterpreterDataMap"),
-  ("read_only_space", 0x05771): (102, "ModuleRequestMap"),
-  ("read_only_space", 0x05799): (103, "PromiseCapabilityMap"),
-  ("read_only_space", 0x057c1): (104, "PromiseReactionMap"),
-  ("read_only_space", 0x057e9): (105, "PropertyDescriptorObjectMap"),
-  ("read_only_space", 0x05811): (106, "PrototypeInfoMap"),
-  ("read_only_space", 0x05839): (107, "RegExpBoilerplateDescriptionMap"),
-  ("read_only_space", 0x05861): (108, "ScriptMap"),
-  ("read_only_space", 0x05889): (109, "SourceTextModuleInfoEntryMap"),
-  ("read_only_space", 0x058b1): (110, "StackFrameInfoMap"),
-  ("read_only_space", 0x058d9): (111, "TemplateObjectDescriptionMap"),
-  ("read_only_space", 0x05901): (112, "Tuple2Map"),
-  ("read_only_space", 0x05929): (113, "WasmExceptionTagMap"),
-  ("read_only_space", 0x05951): (114, "WasmExportedFunctionDataMap"),
-  ("read_only_space", 0x05979): (115, "WasmIndirectFunctionTableMap"),
-  ("read_only_space", 0x059a1): (116, "WasmJSFunctionDataMap"),
-  ("read_only_space", 0x059c9): (134, "SloppyArgumentsElementsMap"),
-  ("read_only_space", 0x059f1): (151, "DescriptorArrayMap"),
-  ("read_only_space", 0x05a19): (156, "UncompiledDataWithoutPreparseDataMap"),
-  ("read_only_space", 0x05a41): (155, "UncompiledDataWithPreparseDataMap"),
-  ("read_only_space", 0x05a69): (171, "OnHeapBasicBlockProfilerDataMap"),
-  ("read_only_space", 0x05a91): (168, "InternalClassMap"),
-  ("read_only_space", 0x05ab9): (178, "SmiPairMap"),
-  ("read_only_space", 0x05ae1): (177, "SmiBoxMap"),
-  ("read_only_space", 0x05b09): (145, "ExportedSubClassBaseMap"),
-  ("read_only_space", 0x05b31): (146, "ExportedSubClassMap"),
-  ("read_only_space", 0x05b59): (68, "AbstractInternalClassSubclass1Map"),
-  ("read_only_space", 0x05b81): (69, "AbstractInternalClassSubclass2Map"),
-  ("read_only_space", 0x05ba9): (133, "InternalClassWithSmiElementsMap"),
-  ("read_only_space", 0x05bd1): (169, "InternalClassWithStructElementsMap"),
-  ("read_only_space", 0x05bf9): (147, "ExportedSubClass2Map"),
-  ("read_only_space", 0x05c21): (179, "SortStateMap"),
-  ("read_only_space", 0x05c49): (182, "WasmCapiFunctionDataMap"),
-  ("read_only_space", 0x05c71): (86, "AllocationSiteWithWeakNextMap"),
-  ("read_only_space", 0x05c99): (86, "AllocationSiteWithoutWeakNextMap"),
-  ("read_only_space", 0x05cc1): (77, "LoadHandler1Map"),
-  ("read_only_space", 0x05ce9): (77, "LoadHandler2Map"),
-  ("read_only_space", 0x05d11): (77, "LoadHandler3Map"),
-  ("read_only_space", 0x05d39): (78, "StoreHandler0Map"),
-  ("read_only_space", 0x05d61): (78, "StoreHandler1Map"),
-  ("read_only_space", 0x05d89): (78, "StoreHandler2Map"),
-  ("read_only_space", 0x05db1): (78, "StoreHandler3Map"),
+  ("read_only_space", 0x029f5): (129, "ObjectBoilerplateDescriptionMap"),
+  ("read_only_space", 0x02a1d): (132, "BytecodeArrayMap"),
+  ("read_only_space", 0x02a45): (162, "CodeDataContainerMap"),
+  ("read_only_space", 0x02a6d): (163, "CoverageInfoMap"),
+  ("read_only_space", 0x02a95): (133, "FixedDoubleArrayMap"),
+  ("read_only_space", 0x02abd): (121, "GlobalDictionaryMap"),
+  ("read_only_space", 0x02ae5): (101, "ManyClosuresCellMap"),
+  ("read_only_space", 0x02b0d): (172, "MegaDomHandlerMap"),
+  ("read_only_space", 0x02b35): (118, "ModuleInfoMap"),
+  ("read_only_space", 0x02b5d): (122, "NameDictionaryMap"),
+  ("read_only_space", 0x02b85): (101, "NoClosuresCellMap"),
+  ("read_only_space", 0x02bad): (123, "NumberDictionaryMap"),
+  ("read_only_space", 0x02bd5): (101, "OneClosureCellMap"),
+  ("read_only_space", 0x02bfd): (124, "OrderedHashMapMap"),
+  ("read_only_space", 0x02c25): (125, "OrderedHashSetMap"),
+  ("read_only_space", 0x02c4d): (126, "OrderedNameDictionaryMap"),
+  ("read_only_space", 0x02c75): (174, "PreparseDataMap"),
+  ("read_only_space", 0x02c9d): (175, "PropertyArrayMap"),
+  ("read_only_space", 0x02cc5): (97, "SideEffectCallHandlerInfoMap"),
+  ("read_only_space", 0x02ced): (97, "SideEffectFreeCallHandlerInfoMap"),
+  ("read_only_space", 0x02d15): (97, "NextCallSideEffectFreeCallHandlerInfoMap"),
+  ("read_only_space", 0x02d3d): (127, "SimpleNumberDictionaryMap"),
+  ("read_only_space", 0x02d65): (149, "SmallOrderedHashMapMap"),
+  ("read_only_space", 0x02d8d): (150, "SmallOrderedHashSetMap"),
+  ("read_only_space", 0x02db5): (151, "SmallOrderedNameDictionaryMap"),
+  ("read_only_space", 0x02ddd): (154, "SourceTextModuleMap"),
+  ("read_only_space", 0x02e05): (182, "SwissNameDictionaryMap"),
+  ("read_only_space", 0x02e2d): (155, "SyntheticModuleMap"),
+  ("read_only_space", 0x02e55): (72, "WasmExportedFunctionDataMap"),
+  ("read_only_space", 0x02e7d): (73, "WasmJSFunctionDataMap"),
+  ("read_only_space", 0x02ea5): (74, "WasmTypeInfoMap"),
+  ("read_only_space", 0x02ecd): (186, "WeakArrayListMap"),
+  ("read_only_space", 0x02ef5): (120, "EphemeronHashTableMap"),
+  ("read_only_space", 0x02f1d): (164, "EmbedderDataArrayMap"),
+  ("read_only_space", 0x02f45): (187, "WeakCellMap"),
+  ("read_only_space", 0x02f6d): (32, "StringMap"),
+  ("read_only_space", 0x02f95): (41, "ConsOneByteStringMap"),
+  ("read_only_space", 0x02fbd): (33, "ConsStringMap"),
+  ("read_only_space", 0x02fe5): (37, "ThinStringMap"),
+  ("read_only_space", 0x0300d): (35, "SlicedStringMap"),
+  ("read_only_space", 0x03035): (43, "SlicedOneByteStringMap"),
+  ("read_only_space", 0x0305d): (34, "ExternalStringMap"),
+  ("read_only_space", 0x03085): (42, "ExternalOneByteStringMap"),
+  ("read_only_space", 0x030ad): (50, "UncachedExternalStringMap"),
+  ("read_only_space", 0x030d5): (0, "InternalizedStringMap"),
+  ("read_only_space", 0x030fd): (2, "ExternalInternalizedStringMap"),
+  ("read_only_space", 0x03125): (10, "ExternalOneByteInternalizedStringMap"),
+  ("read_only_space", 0x0314d): (18, "UncachedExternalInternalizedStringMap"),
+  ("read_only_space", 0x03175): (26, "UncachedExternalOneByteInternalizedStringMap"),
+  ("read_only_space", 0x0319d): (58, "UncachedExternalOneByteStringMap"),
+  ("read_only_space", 0x031c5): (67, "SelfReferenceMarkerMap"),
+  ("read_only_space", 0x031ed): (67, "BasicBlockCountersMarkerMap"),
+  ("read_only_space", 0x03231): (90, "ArrayBoilerplateDescriptionMap"),
+  ("read_only_space", 0x03331): (103, "InterceptorInfoMap"),
+  ("read_only_space", 0x05639): (75, "PromiseFulfillReactionJobTaskMap"),
+  ("read_only_space", 0x05661): (76, "PromiseRejectReactionJobTaskMap"),
+  ("read_only_space", 0x05689): (77, "CallableTaskMap"),
+  ("read_only_space", 0x056b1): (78, "CallbackTaskMap"),
+  ("read_only_space", 0x056d9): (79, "PromiseResolveThenableJobTaskMap"),
+  ("read_only_space", 0x05701): (82, "FunctionTemplateInfoMap"),
+  ("read_only_space", 0x05729): (83, "ObjectTemplateInfoMap"),
+  ("read_only_space", 0x05751): (84, "AccessCheckInfoMap"),
+  ("read_only_space", 0x05779): (85, "AccessorInfoMap"),
+  ("read_only_space", 0x057a1): (86, "AccessorPairMap"),
+  ("read_only_space", 0x057c9): (87, "AliasedArgumentsEntryMap"),
+  ("read_only_space", 0x057f1): (88, "AllocationMementoMap"),
+  ("read_only_space", 0x05819): (91, "AsmWasmDataMap"),
+  ("read_only_space", 0x05841): (92, "AsyncGeneratorRequestMap"),
+  ("read_only_space", 0x05869): (93, "BaselineDataMap"),
+  ("read_only_space", 0x05891): (94, "BreakPointMap"),
+  ("read_only_space", 0x058b9): (95, "BreakPointInfoMap"),
+  ("read_only_space", 0x058e1): (96, "CachedTemplateObjectMap"),
+  ("read_only_space", 0x05909): (98, "ClassPositionsMap"),
+  ("read_only_space", 0x05931): (99, "DebugInfoMap"),
+  ("read_only_space", 0x05959): (102, "FunctionTemplateRareDataMap"),
+  ("read_only_space", 0x05981): (104, "InterpreterDataMap"),
+  ("read_only_space", 0x059a9): (105, "ModuleRequestMap"),
+  ("read_only_space", 0x059d1): (106, "PromiseCapabilityMap"),
+  ("read_only_space", 0x059f9): (107, "PromiseReactionMap"),
+  ("read_only_space", 0x05a21): (108, "PropertyDescriptorObjectMap"),
+  ("read_only_space", 0x05a49): (109, "PrototypeInfoMap"),
+  ("read_only_space", 0x05a71): (110, "RegExpBoilerplateDescriptionMap"),
+  ("read_only_space", 0x05a99): (111, "ScriptMap"),
+  ("read_only_space", 0x05ac1): (112, "SourceTextModuleInfoEntryMap"),
+  ("read_only_space", 0x05ae9): (113, "StackFrameInfoMap"),
+  ("read_only_space", 0x05b11): (114, "TemplateObjectDescriptionMap"),
+  ("read_only_space", 0x05b39): (115, "Tuple2Map"),
+  ("read_only_space", 0x05b61): (116, "WasmExceptionTagMap"),
+  ("read_only_space", 0x05b89): (117, "WasmIndirectFunctionTableMap"),
+  ("read_only_space", 0x05bb1): (135, "SloppyArgumentsElementsMap"),
+  ("read_only_space", 0x05bd9): (152, "DescriptorArrayMap"),
+  ("read_only_space", 0x05c01): (157, "UncompiledDataWithoutPreparseDataMap"),
+  ("read_only_space", 0x05c29): (156, "UncompiledDataWithPreparseDataMap"),
+  ("read_only_space", 0x05c51): (173, "OnHeapBasicBlockProfilerDataMap"),
+  ("read_only_space", 0x05c79): (169, "InternalClassMap"),
+  ("read_only_space", 0x05ca1): (180, "SmiPairMap"),
+  ("read_only_space", 0x05cc9): (179, "SmiBoxMap"),
+  ("read_only_space", 0x05cf1): (146, "ExportedSubClassBaseMap"),
+  ("read_only_space", 0x05d19): (147, "ExportedSubClassMap"),
+  ("read_only_space", 0x05d41): (68, "AbstractInternalClassSubclass1Map"),
+  ("read_only_space", 0x05d69): (69, "AbstractInternalClassSubclass2Map"),
+  ("read_only_space", 0x05d91): (134, "InternalClassWithSmiElementsMap"),
+  ("read_only_space", 0x05db9): (170, "InternalClassWithStructElementsMap"),
+  ("read_only_space", 0x05de1): (148, "ExportedSubClass2Map"),
+  ("read_only_space", 0x05e09): (181, "SortStateMap"),
+  ("read_only_space", 0x05e31): (184, "WasmCapiFunctionDataMap"),
+  ("read_only_space", 0x05e59): (89, "AllocationSiteWithWeakNextMap"),
+  ("read_only_space", 0x05e81): (89, "AllocationSiteWithoutWeakNextMap"),
+  ("read_only_space", 0x05ea9): (80, "LoadHandler1Map"),
+  ("read_only_space", 0x05ed1): (80, "LoadHandler2Map"),
+  ("read_only_space", 0x05ef9): (80, "LoadHandler3Map"),
+  ("read_only_space", 0x05f21): (81, "StoreHandler0Map"),
+  ("read_only_space", 0x05f49): (81, "StoreHandler1Map"),
+  ("read_only_space", 0x05f71): (81, "StoreHandler2Map"),
+  ("read_only_space", 0x05f99): (81, "StoreHandler3Map"),
   ("map_space", 0x02119): (1057, "ExternalMap"),
   ("map_space", 0x02141): (1098, "JSMessageObjectMap"),
 }
@@ -411,32 +414,32 @@ KNOWN_OBJECTS = {
   ("read_only_space", 0x0282d): "TerminationException",
   ("read_only_space", 0x02895): "OptimizedOut",
   ("read_only_space", 0x028f5): "StaleRegister",
-  ("read_only_space", 0x0319d): "EmptyPropertyArray",
-  ("read_only_space", 0x031a5): "EmptyByteArray",
-  ("read_only_space", 0x031ad): "EmptyObjectBoilerplateDescription",
-  ("read_only_space", 0x031e1): "EmptyArrayBoilerplateDescription",
-  ("read_only_space", 0x031ed): "EmptyClosureFeedbackCellArray",
-  ("read_only_space", 0x031f5): "EmptySlowElementDictionary",
-  ("read_only_space", 0x03219): "EmptyOrderedHashMap",
-  ("read_only_space", 0x0322d): "EmptyOrderedHashSet",
-  ("read_only_space", 0x03241): "EmptyFeedbackMetadata",
-  ("read_only_space", 0x0324d): "EmptyPropertyDictionary",
-  ("read_only_space", 0x03275): "EmptyOrderedPropertyDictionary",
-  ("read_only_space", 0x0328d): "EmptySwissPropertyDictionary",
-  ("read_only_space", 0x032e1): "NoOpInterceptorInfo",
-  ("read_only_space", 0x03309): "EmptyWeakArrayList",
-  ("read_only_space", 0x03315): "InfinityValue",
-  ("read_only_space", 0x03321): "MinusZeroValue",
-  ("read_only_space", 0x0332d): "MinusInfinityValue",
-  ("read_only_space", 0x03339): "SelfReferenceMarker",
-  ("read_only_space", 0x03379): "BasicBlockCountersMarker",
-  ("read_only_space", 0x033bd): "OffHeapTrampolineRelocationInfo",
-  ("read_only_space", 0x033c9): "TrampolineTrivialCodeDataContainer",
-  ("read_only_space", 0x033d5): "TrampolinePromiseRejectionCodeDataContainer",
-  ("read_only_space", 0x033e1): "GlobalThisBindingScopeInfo",
-  ("read_only_space", 0x03415): "EmptyFunctionScopeInfo",
-  ("read_only_space", 0x03439): "NativeScopeInfo",
-  ("read_only_space", 0x03451): "HashSeed",
+  ("read_only_space", 0x03215): "EmptyPropertyArray",
+  ("read_only_space", 0x0321d): "EmptyByteArray",
+  ("read_only_space", 0x03225): "EmptyObjectBoilerplateDescription",
+  ("read_only_space", 0x03259): "EmptyArrayBoilerplateDescription",
+  ("read_only_space", 0x03265): "EmptyClosureFeedbackCellArray",
+  ("read_only_space", 0x0326d): "EmptySlowElementDictionary",
+  ("read_only_space", 0x03291): "EmptyOrderedHashMap",
+  ("read_only_space", 0x032a5): "EmptyOrderedHashSet",
+  ("read_only_space", 0x032b9): "EmptyFeedbackMetadata",
+  ("read_only_space", 0x032c5): "EmptyPropertyDictionary",
+  ("read_only_space", 0x032ed): "EmptyOrderedPropertyDictionary",
+  ("read_only_space", 0x03305): "EmptySwissPropertyDictionary",
+  ("read_only_space", 0x03359): "NoOpInterceptorInfo",
+  ("read_only_space", 0x03381): "EmptyWeakArrayList",
+  ("read_only_space", 0x0338d): "InfinityValue",
+  ("read_only_space", 0x03399): "MinusZeroValue",
+  ("read_only_space", 0x033a5): "MinusInfinityValue",
+  ("read_only_space", 0x033b1): "SelfReferenceMarker",
+  ("read_only_space", 0x033f1): "BasicBlockCountersMarker",
+  ("read_only_space", 0x03435): "OffHeapTrampolineRelocationInfo",
+  ("read_only_space", 0x03441): "TrampolineTrivialCodeDataContainer",
+  ("read_only_space", 0x0344d): "TrampolinePromiseRejectionCodeDataContainer",
+  ("read_only_space", 0x03459): "GlobalThisBindingScopeInfo",
+  ("read_only_space", 0x0348d): "EmptyFunctionScopeInfo",
+  ("read_only_space", 0x034b1): "NativeScopeInfo",
+  ("read_only_space", 0x034c9): "HashSeed",
   ("old_space", 0x02119): "ArgumentsIteratorAccessor",
   ("old_space", 0x0215d): "ArrayLengthAccessor",
   ("old_space", 0x021a1): "BoundFunctionLengthAccessor",
@@ -453,52 +456,53 @@ KNOWN_OBJECTS = {
   ("old_space", 0x0244d): "ManyClosuresCell",
   ("old_space", 0x02459): "ArrayConstructorProtector",
   ("old_space", 0x0246d): "NoElementsProtector",
-  ("old_space", 0x02481): "IsConcatSpreadableProtector",
-  ("old_space", 0x02495): "ArraySpeciesProtector",
-  ("old_space", 0x024a9): "TypedArraySpeciesProtector",
-  ("old_space", 0x024bd): "PromiseSpeciesProtector",
-  ("old_space", 0x024d1): "RegExpSpeciesProtector",
-  ("old_space", 0x024e5): "StringLengthProtector",
-  ("old_space", 0x024f9): "ArrayIteratorProtector",
-  ("old_space", 0x0250d): "ArrayBufferDetachingProtector",
-  ("old_space", 0x02521): "PromiseHookProtector",
-  ("old_space", 0x02535): "PromiseResolveProtector",
-  ("old_space", 0x02549): "MapIteratorProtector",
-  ("old_space", 0x0255d): "PromiseThenProtector",
-  ("old_space", 0x02571): "SetIteratorProtector",
-  ("old_space", 0x02585): "StringIteratorProtector",
-  ("old_space", 0x02599): "SingleCharacterStringCache",
-  ("old_space", 0x029a1): "StringSplitCache",
-  ("old_space", 0x02da9): "RegExpMultipleCache",
-  ("old_space", 0x031b1): "BuiltinsConstantsTable",
-  ("old_space", 0x035b1): "AsyncFunctionAwaitRejectSharedFun",
-  ("old_space", 0x035d5): "AsyncFunctionAwaitResolveSharedFun",
-  ("old_space", 0x035f9): "AsyncGeneratorAwaitRejectSharedFun",
-  ("old_space", 0x0361d): "AsyncGeneratorAwaitResolveSharedFun",
-  ("old_space", 0x03641): "AsyncGeneratorYieldResolveSharedFun",
-  ("old_space", 0x03665): "AsyncGeneratorReturnResolveSharedFun",
-  ("old_space", 0x03689): "AsyncGeneratorReturnClosedRejectSharedFun",
-  ("old_space", 0x036ad): "AsyncGeneratorReturnClosedResolveSharedFun",
-  ("old_space", 0x036d1): "AsyncIteratorValueUnwrapSharedFun",
-  ("old_space", 0x036f5): "PromiseAllResolveElementSharedFun",
-  ("old_space", 0x03719): "PromiseAllSettledResolveElementSharedFun",
-  ("old_space", 0x0373d): "PromiseAllSettledRejectElementSharedFun",
-  ("old_space", 0x03761): "PromiseAnyRejectElementSharedFun",
-  ("old_space", 0x03785): "PromiseCapabilityDefaultRejectSharedFun",
-  ("old_space", 0x037a9): "PromiseCapabilityDefaultResolveSharedFun",
-  ("old_space", 0x037cd): "PromiseCatchFinallySharedFun",
-  ("old_space", 0x037f1): "PromiseGetCapabilitiesExecutorSharedFun",
-  ("old_space", 0x03815): "PromiseThenFinallySharedFun",
-  ("old_space", 0x03839): "PromiseThrowerFinallySharedFun",
-  ("old_space", 0x0385d): "PromiseValueThunkFinallySharedFun",
-  ("old_space", 0x03881): "ProxyRevokeSharedFun",
+  ("old_space", 0x02481): "MegaDOMProtector",
+  ("old_space", 0x02495): "IsConcatSpreadableProtector",
+  ("old_space", 0x024a9): "ArraySpeciesProtector",
+  ("old_space", 0x024bd): "TypedArraySpeciesProtector",
+  ("old_space", 0x024d1): "PromiseSpeciesProtector",
+  ("old_space", 0x024e5): "RegExpSpeciesProtector",
+  ("old_space", 0x024f9): "StringLengthProtector",
+  ("old_space", 0x0250d): "ArrayIteratorProtector",
+  ("old_space", 0x02521): "ArrayBufferDetachingProtector",
+  ("old_space", 0x02535): "PromiseHookProtector",
+  ("old_space", 0x02549): "PromiseResolveProtector",
+  ("old_space", 0x0255d): "MapIteratorProtector",
+  ("old_space", 0x02571): "PromiseThenProtector",
+  ("old_space", 0x02585): "SetIteratorProtector",
+  ("old_space", 0x02599): "StringIteratorProtector",
+  ("old_space", 0x025ad): "SingleCharacterStringCache",
+  ("old_space", 0x029b5): "StringSplitCache",
+  ("old_space", 0x02dbd): "RegExpMultipleCache",
+  ("old_space", 0x031c5): "BuiltinsConstantsTable",
+  ("old_space", 0x035d1): "AsyncFunctionAwaitRejectSharedFun",
+  ("old_space", 0x035f5): "AsyncFunctionAwaitResolveSharedFun",
+  ("old_space", 0x03619): "AsyncGeneratorAwaitRejectSharedFun",
+  ("old_space", 0x0363d): "AsyncGeneratorAwaitResolveSharedFun",
+  ("old_space", 0x03661): "AsyncGeneratorYieldResolveSharedFun",
+  ("old_space", 0x03685): "AsyncGeneratorReturnResolveSharedFun",
+  ("old_space", 0x036a9): "AsyncGeneratorReturnClosedRejectSharedFun",
+  ("old_space", 0x036cd): "AsyncGeneratorReturnClosedResolveSharedFun",
+  ("old_space", 0x036f1): "AsyncIteratorValueUnwrapSharedFun",
+  ("old_space", 0x03715): "PromiseAllResolveElementSharedFun",
+  ("old_space", 0x03739): "PromiseAllSettledResolveElementSharedFun",
+  ("old_space", 0x0375d): "PromiseAllSettledRejectElementSharedFun",
+  ("old_space", 0x03781): "PromiseAnyRejectElementSharedFun",
+  ("old_space", 0x037a5): "PromiseCapabilityDefaultRejectSharedFun",
+  ("old_space", 0x037c9): "PromiseCapabilityDefaultResolveSharedFun",
+  ("old_space", 0x037ed): "PromiseCatchFinallySharedFun",
+  ("old_space", 0x03811): "PromiseGetCapabilitiesExecutorSharedFun",
+  ("old_space", 0x03835): "PromiseThenFinallySharedFun",
+  ("old_space", 0x03859): "PromiseThrowerFinallySharedFun",
+  ("old_space", 0x0387d): "PromiseValueThunkFinallySharedFun",
+  ("old_space", 0x038a1): "ProxyRevokeSharedFun",
 }
 
 # Lower 32 bits of first page addresses for various heap spaces.
 HEAP_FIRST_PAGES = {
-  0x08100000: "old_space",
-  0x08140000: "map_space",
-  0x08040000: "read_only_space",
+  0x080c0000: "old_space",
+  0x08100000: "map_space",
+  0x08000000: "read_only_space",
 }
 
 # List of known V8 Frame Markers.
diff --git a/chromium/v8/tools/v8windbg/BUILD.gn b/chromium/v8/tools/v8windbg/BUILD.gn
index 5618d2d9455..e30b826b0f4 100644
--- a/chromium/v8/tools/v8windbg/BUILD.gn
+++ b/chromium/v8/tools/v8windbg/BUILD.gn
@@ -42,8 +42,6 @@ v8_shared_library("v8windbg") {
     "src/cur-isolate.h",
     "src/js-stack.cc",
     "src/js-stack.h",
-    "src/list-chunks.cc",
-    "src/list-chunks.h",
     "src/local-variables.cc",
     "src/local-variables.h",
     "src/object-inspection.cc",
@@ -56,6 +54,9 @@ v8_shared_library("v8windbg") {
 
   deps = [
     ":v8windbg_base",
+    "../../:v8_flags",
+    "../../:v8_libbase",
+    "../../:v8_shared_internal_headers",
     "../debug_helper:v8_debug_helper",
   ]
 }
diff --git a/chromium/v8/tools/v8windbg/README.md b/chromium/v8/tools/v8windbg/README.md
index de6638e4d43..887f437b0de 100644
--- a/chromium/v8/tools/v8windbg/README.md
+++ b/chromium/v8/tools/v8windbg/README.md
@@ -41,8 +41,6 @@ functions that can be called from within `dx` commands:
   like `dx @$v8object(0x34f49880471, "v8::internal::JSArray")`.
 - `@$curisolate()` gets the Isolate pointer for the current thread, if the
   current thread has a JavaScript Isolate associated.
-- `@$listchunks()` returns a list of the memory chunks in the Heap for the
-  current Isolate.
 - `@$jsstack()` returns a list of the JS stack frames, including information 
 about script and function.
 
@@ -67,8 +65,6 @@ functions declared in `dbgext.h` to create and destroy the extension instance.
 `./src` file index:
 
 - `cur-isolate.{cc,h}` implements the `IModelMethod` for `@$curisolate()`.
-- `list-chunks.{cc,h}` implements the `IModelMethod` for `@$listchunks()`. Its
-  result is a custom object that supports iteration and indexing.
 - `js-stack.{cc,h}` implements the `IModelMethod` for `@$jsstack()`. Its
   result is a custom object that supports iteration and indexing. 
 - `local-variables.{cc,h}` implements the `IModelPropertyAccessor` that provides
diff --git a/chromium/v8/tools/v8windbg/src/list-chunks.cc b/chromium/v8/tools/v8windbg/src/list-chunks.cc
deleted file mode 100644
index 90b3ff6af69..00000000000
--- a/chromium/v8/tools/v8windbg/src/list-chunks.cc
+++ /dev/null
@@ -1,238 +0,0 @@
-// Copyright 2020 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "tools/v8windbg/src/list-chunks.h"
-
-#include "tools/v8windbg/src/cur-isolate.h"
-
-// v8windbg!ListChunksAlias::Call
-IFACEMETHODIMP ListChunksAlias::Call(IModelObject* p_context_object,
-                                     ULONG64 arg_count,
-                                     _In_reads_(arg_count)
-                                         IModelObject** pp_arguments,
-                                     IModelObject** pp_result,
-                                     IKeyStore** pp_metadata) noexcept {
-  WRL::ComPtr<IDebugHostContext> sp_ctx;
-  RETURN_IF_FAIL(sp_debug_host->GetCurrentContext(&sp_ctx));
-
-  WRL::ComPtr<IModelObject> result;
-  RETURN_IF_FAIL(
-      sp_data_model_manager->CreateSyntheticObject(sp_ctx.Get(), &result));
-
-  auto sp_iterator{WRL::Make<MemoryChunks>()};
-
-  RETURN_IF_FAIL(result->SetConcept(
-      __uuidof(IIndexableConcept),
-      static_cast<IIndexableConcept*>(sp_iterator.Get()), nullptr));
-  RETURN_IF_FAIL(result->SetConcept(
-      __uuidof(IIterableConcept),
-      static_cast<IIterableConcept*>(sp_iterator.Get()), nullptr));
-
-  *pp_result = result.Detach();
-  if (pp_metadata) {
-    *pp_metadata = nullptr;
-  }
-  return S_OK;
-}
-
-ChunkData::ChunkData() = default;
-ChunkData::~ChunkData() = default;
-ChunkData::ChunkData(const ChunkData&) = default;
-ChunkData::ChunkData(ChunkData&&) = default;
-ChunkData& ChunkData::operator=(const ChunkData&) = default;
-ChunkData& ChunkData::operator=(ChunkData&&) = default;
-
-MemoryChunkIterator::MemoryChunkIterator(
-    WRL::ComPtr<IDebugHostContext>& host_context)
-    : sp_ctx_(host_context) {}
-MemoryChunkIterator::~MemoryChunkIterator() = default;
-
-HRESULT MemoryChunkIterator::PopulateChunkData() {
-  WRL::ComPtr<IModelObject> sp_isolate, sp_heap, sp_space;
-  chunks_.clear();
-
-  RETURN_IF_FAIL(GetCurrentIsolate(sp_isolate));
-
-  RETURN_IF_FAIL(
-      sp_isolate->GetRawValue(SymbolField, L"heap_", RawSearchNone, &sp_heap));
-  RETURN_IF_FAIL(
-      sp_heap->GetRawValue(SymbolField, L"space_", RawSearchNone, &sp_space));
-
-  WRL::ComPtr<IDebugHostType> sp_space_type;
-  RETURN_IF_FAIL(sp_space->GetTypeInfo(&sp_space_type));
-
-  // Iterate over the array of Space pointers
-  WRL::ComPtr<IIterableConcept> sp_iterable;
-  RETURN_IF_FAIL(
-      sp_space->GetConcept(__uuidof(IIterableConcept), &sp_iterable, nullptr));
-
-  WRL::ComPtr<IModelIterator> sp_space_iterator;
-  RETURN_IF_FAIL(sp_iterable->GetIterator(sp_space.Get(), &sp_space_iterator));
-
-  // Loop through all the spaces in the array
-  WRL::ComPtr<IModelObject> sp_space_ptr;
-  while (sp_space_iterator->GetNext(&sp_space_ptr, 0, nullptr, nullptr) !=
-         E_BOUNDS) {
-    // Should have gotten a "v8::internal::Space *". Dereference, then get field
-    // "memory_chunk_list_" [Type: v8::base::List<v8::internal::MemoryChunk>]
-    WRL::ComPtr<IModelObject> sp_space, sp_chunk_list, sp_mem_chunk_ptr,
-        sp_mem_chunk;
-    RETURN_IF_FAIL(sp_space_ptr->Dereference(&sp_space));
-    RETURN_IF_FAIL(sp_space->GetRawValue(SymbolField, L"memory_chunk_list_",
-                                         RawSearchNone, &sp_chunk_list));
-
-    // Then get field "front_" [Type: v8::internal::MemoryChunk *]
-    RETURN_IF_FAIL(sp_chunk_list->GetRawValue(
-        SymbolField, L"front_", RawSearchNone, &sp_mem_chunk_ptr));
-
-    // Loop here on the list of MemoryChunks for the space
-    while (true) {
-      // See if it is a nullptr (i.e. no chunks in this space)
-      uint64_t front_val;
-      RETURN_IF_FAIL(
-          UnboxULong64(sp_mem_chunk_ptr.Get(), &front_val, true /*convert*/));
-      if (front_val == 0) {
-        break;
-      }
-
-      // Dereference and get fields "area_start_" and "area_end_" (both uint64)
-      RETURN_IF_FAIL(sp_mem_chunk_ptr->Dereference(&sp_mem_chunk));
-
-      WRL::ComPtr<IModelObject> sp_start, sp_end;
-      RETURN_IF_FAIL(sp_mem_chunk->GetRawValue(SymbolField, L"area_start_",
-                                               RawSearchNone, &sp_start));
-      RETURN_IF_FAIL(sp_mem_chunk->GetRawValue(SymbolField, L"area_end_",
-                                               RawSearchNone, &sp_end));
-
-      ChunkData chunk_entry;
-      chunk_entry.area_start = sp_start;
-      chunk_entry.area_end = sp_end;
-      chunk_entry.space = sp_space;
-      chunks_.push_back(chunk_entry);
-
-      // Follow the list_node_.next_ to the next memory chunk
-      WRL::ComPtr<IModelObject> sp_list_node;
-      RETURN_IF_FAIL(sp_mem_chunk->GetRawValue(SymbolField, L"list_node_",
-                                               RawSearchNone, &sp_list_node));
-
-      sp_mem_chunk_ptr = nullptr;
-      sp_mem_chunk = nullptr;
-      RETURN_IF_FAIL(sp_list_node->GetRawValue(
-          SymbolField, L"next_", RawSearchNone, &sp_mem_chunk_ptr));
-      // Top of the loop will check if this is a nullptr and exit if so
-    }
-    sp_space_ptr = nullptr;
-  }
-
-  return S_OK;
-}
-
-IFACEMETHODIMP MemoryChunkIterator::Reset() noexcept {
-  position_ = 0;
-  return S_OK;
-}
-
-IFACEMETHODIMP MemoryChunkIterator::GetNext(IModelObject** object,
-                                            ULONG64 dimensions,
-                                            IModelObject** indexers,
-                                            IKeyStore** metadata) noexcept {
-  if (dimensions > 1) return E_INVALIDARG;
-
-  if (position_ == 0) {
-    RETURN_IF_FAIL(PopulateChunkData());
-  }
-
-  if (metadata != nullptr) *metadata = nullptr;
-
-  WRL::ComPtr<IModelObject> sp_index, sp_value;
-
-  if (dimensions == 1) {
-    RETURN_IF_FAIL(CreateULong64(position_, &sp_index));
-  }
-
-  RETURN_IF_FAIL(GetAt(position_, &sp_value));
-
-  // Now update counter and transfer ownership of results, because nothing can
-  // fail from this point onward.
-  ++position_;
-  if (dimensions == 1) {
-    *indexers = sp_index.Detach();
-  }
-  *object = sp_value.Detach();
-  return S_OK;
-}
-
-HRESULT MemoryChunkIterator::GetAt(uint64_t index,
-                                   IModelObject** result) const {
-  if (index >= chunks_.size()) return E_BOUNDS;
-
-  // Create the synthetic object representing the chunk here
-  const ChunkData& curr_chunk = chunks_.at(index);
-  WRL::ComPtr<IModelObject> sp_value;
-  RETURN_IF_FAIL(
-      sp_data_model_manager->CreateSyntheticObject(sp_ctx_.Get(), &sp_value));
-  RETURN_IF_FAIL(
-      sp_value->SetKey(L"area_start", curr_chunk.area_start.Get(), nullptr));
-  RETURN_IF_FAIL(
-      sp_value->SetKey(L"area_end", curr_chunk.area_end.Get(), nullptr));
-  RETURN_IF_FAIL(sp_value->SetKey(L"space", curr_chunk.space.Get(), nullptr));
-
-  *result = sp_value.Detach();
-  return S_OK;
-}
-
-MemoryChunks::MemoryChunks() = default;
-MemoryChunks::~MemoryChunks() = default;
-
-IFACEMETHODIMP MemoryChunks::GetDimensionality(
-    IModelObject* context_object, ULONG64* dimensionality) noexcept {
-  *dimensionality = 1;
-  return S_OK;
-}
-
-IFACEMETHODIMP MemoryChunks::GetAt(IModelObject* context_object,
-                                   ULONG64 indexer_count,
-                                   IModelObject** indexers,
-                                   IModelObject** object,
-                                   IKeyStore** metadata) noexcept {
-  if (indexer_count != 1) return E_INVALIDARG;
-  if (metadata != nullptr) *metadata = nullptr;
-  WRL::ComPtr<IDebugHostContext> sp_ctx;
-  RETURN_IF_FAIL(context_object->GetContext(&sp_ctx));
-
-  // This should be instantiated once for each synthetic object returned,
-  // so should be able to cache/reuse an iterator
-  if (opt_chunks_ == nullptr) {
-    opt_chunks_ = WRL::Make<MemoryChunkIterator>(sp_ctx);
-    _ASSERT(opt_chunks_ != nullptr);
-    RETURN_IF_FAIL(opt_chunks_->PopulateChunkData());
-  }
-
-  uint64_t index;
-  RETURN_IF_FAIL(UnboxULong64(indexers[0], &index, true /*convert*/));
-
-  return opt_chunks_->GetAt(index, object);
-}
-
-IFACEMETHODIMP MemoryChunks::SetAt(IModelObject* context_object,
-                                   ULONG64 indexer_count,
-                                   IModelObject** indexers,
-                                   IModelObject* value) noexcept {
-  return E_NOTIMPL;
-}
-
-IFACEMETHODIMP MemoryChunks::GetDefaultIndexDimensionality(
-    IModelObject* context_object, ULONG64* dimensionality) noexcept {
-  *dimensionality = 1;
-  return S_OK;
-}
-
-IFACEMETHODIMP MemoryChunks::GetIterator(IModelObject* context_object,
-                                         IModelIterator** iterator) noexcept {
-  WRL::ComPtr<IDebugHostContext> sp_ctx;
-  RETURN_IF_FAIL(context_object->GetContext(&sp_ctx));
-  auto sp_memory_iterator{WRL::Make<MemoryChunkIterator>(sp_ctx)};
-  *iterator = sp_memory_iterator.Detach();
-  return S_OK;
-}
diff --git a/chromium/v8/tools/v8windbg/src/list-chunks.h b/chromium/v8/tools/v8windbg/src/list-chunks.h
deleted file mode 100644
index 10eec100d17..00000000000
--- a/chromium/v8/tools/v8windbg/src/list-chunks.h
+++ /dev/null
@@ -1,100 +0,0 @@
-// Copyright 2020 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef V8_TOOLS_V8WINDBG_SRC_LIST_CHUNKS_H_
-#define V8_TOOLS_V8WINDBG_SRC_LIST_CHUNKS_H_
-
-#include <crtdbg.h>
-#include <wrl/implements.h>
-
-#include <optional>
-#include <string>
-#include <vector>
-
-#include "src/base/optional.h"
-#include "tools/v8windbg/base/utilities.h"
-#include "tools/v8windbg/src/v8-debug-helper-interop.h"
-#include "tools/v8windbg/src/v8windbg-extension.h"
-
-class ListChunksAlias
-    : public WRL::RuntimeClass<
-          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
-          IModelMethod> {
- public:
-  IFACEMETHOD(Call)
-  (IModelObject* p_context_object, ULONG64 arg_count,
-   _In_reads_(arg_count) IModelObject** pp_arguments, IModelObject** pp_result,
-   IKeyStore** pp_metadata);
-};
-
-struct ChunkData {
-  ChunkData();
-  ~ChunkData();
-  ChunkData(const ChunkData&);
-  ChunkData(ChunkData&&);
-  ChunkData& operator=(const ChunkData&);
-  ChunkData& operator=(ChunkData&&);
-  WRL::ComPtr<IModelObject> area_start;
-  WRL::ComPtr<IModelObject> area_end;
-  WRL::ComPtr<IModelObject> space;
-};
-
-class MemoryChunkIterator
-    : public WRL::RuntimeClass<
-          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
-          IModelIterator> {
- public:
-  MemoryChunkIterator(WRL::ComPtr<IDebugHostContext>& host_context);
-  ~MemoryChunkIterator() override;
-
-  HRESULT PopulateChunkData();
-
-  IFACEMETHOD(Reset)();
-
-  IFACEMETHOD(GetNext)
-  (IModelObject** object, ULONG64 dimensions, IModelObject** indexers,
-   IKeyStore** metadata);
-
-  const std::vector<ChunkData>& GetChunks() const { return chunks_; }
-
-  HRESULT GetAt(uint64_t index, IModelObject** result) const;
-
- private:
-  ULONG position_ = 0;
-  std::vector<ChunkData> chunks_;
-  WRL::ComPtr<IDebugHostContext> sp_ctx_;
-};
-
-class MemoryChunks
-    : public WRL::RuntimeClass<
-          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
-          IIndexableConcept, IIterableConcept> {
- public:
-  MemoryChunks();
-  ~MemoryChunks() override;
-
-  // IIndexableConcept members
-  IFACEMETHOD(GetDimensionality)
-  (IModelObject* context_object, ULONG64* dimensionality);
-
-  IFACEMETHOD(GetAt)
-  (IModelObject* context_object, ULONG64 indexer_count, IModelObject** indexers,
-   IModelObject** object, IKeyStore** metadata);
-
-  IFACEMETHOD(SetAt)
-  (IModelObject* context_object, ULONG64 indexer_count, IModelObject** indexers,
-   IModelObject* value);
-
-  // IIterableConcept
-  IFACEMETHOD(GetDefaultIndexDimensionality)
-  (IModelObject* context_object, ULONG64* dimensionality);
-
-  IFACEMETHOD(GetIterator)
-  (IModelObject* context_object, IModelIterator** iterator);
-
- private:
-  WRL::ComPtr<MemoryChunkIterator> opt_chunks_;
-};
-
-#endif  // V8_TOOLS_V8WINDBG_SRC_LIST_CHUNKS_H_
diff --git a/chromium/v8/tools/v8windbg/src/v8windbg-extension.cc b/chromium/v8/tools/v8windbg/src/v8windbg-extension.cc
index 7fbe39d1920..55014cfc8e3 100644
--- a/chromium/v8/tools/v8windbg/src/v8windbg-extension.cc
+++ b/chromium/v8/tools/v8windbg/src/v8windbg-extension.cc
@@ -9,14 +9,12 @@
 #include "tools/v8windbg/base/utilities.h"
 #include "tools/v8windbg/src/cur-isolate.h"
 #include "tools/v8windbg/src/js-stack.h"
-#include "tools/v8windbg/src/list-chunks.h"
 #include "tools/v8windbg/src/local-variables.h"
 #include "tools/v8windbg/src/object-inspection.h"
 
 std::unique_ptr<Extension> Extension::current_extension_ = nullptr;
 const wchar_t* pcur_isolate = L"curisolate";
 const wchar_t* pjs_stack = L"jsstack";
-const wchar_t* plist_chunks = L"listchunks";
 const wchar_t* pv8_object = L"v8object";
 
 HRESULT CreateExtension() {
@@ -263,7 +261,6 @@ HRESULT Extension::Initialize() {
   std::vector<std::pair<const wchar_t*, WRL::ComPtr<IModelMethod>>> functions =
       {{pcur_isolate, WRL::Make<CurrIsolateAlias>()},
        {pjs_stack, WRL::Make<JSStackAlias>()},
-       {plist_chunks, WRL::Make<ListChunksAlias>()},
        {pv8_object, WRL::Make<InspectV8ObjectMethod>()}};
   for (const auto& function : functions) {
     WRL::ComPtr<IModelObject> method;
@@ -375,7 +372,6 @@ Extension::RegistrationType& Extension::RegistrationType::operator=(
 Extension::~Extension() {
   sp_debug_host_extensibility->DestroyFunctionAlias(pcur_isolate);
   sp_debug_host_extensibility->DestroyFunctionAlias(pjs_stack);
-  sp_debug_host_extensibility->DestroyFunctionAlias(plist_chunks);
   sp_debug_host_extensibility->DestroyFunctionAlias(pv8_object);
 
   for (const auto& registered : registered_types_) {
diff --git a/chromium/v8/tools/whitespace.txt b/chromium/v8/tools/whitespace.txt
index 61fd2e94864..8542464212c 100644
--- a/chromium/v8/tools/whitespace.txt
+++ b/chromium/v8/tools/whitespace.txt
@@ -6,9 +6,9 @@ A Smi balks into a war and says:
 "I'm so deoptimized today!"
 The doubles heard this and started to unbox.
 The Smi looked at them when a crazy v8-autoroll account showed up...
-The autoroller bought a round of Himbeerbrause. Suddenly.....
+The autoroller bought a round of Himbeerbrause. Suddenly........
 The bartender starts to shake the bottles...........................
-I can't add trailing whitespaces, so I'm adding this line...........
+I can't add trailing whitespaces, so I'm adding this line............
 I'm starting to think that just adding trailing whitespaces might not be bad.
 
 Because whitespaces are not that funny......