Upgrade V8 to 3.4.8

1 files changed, 1335 insertions, 240 deletions

diff --git a/deps/v8/src/x64/macro-assembler-x64.cc b/deps/v8/src/x64/macro-assembler-x64.cc
index 8845bbb77c..7c8a3667e3 100644
--- a/deps/v8/src/x64/macro-assembler-x64.cc
+++ b/deps/v8/src/x64/macro-assembler-x64.cc
@@ -30,7 +30,7 @@
 #if defined(V8_TARGET_ARCH_X64)
 
 #include "bootstrapper.h"
-#include "codegen-inl.h"
+#include "codegen.h"
 #include "assembler-x64.h"
 #include "macro-assembler-x64.h"
 #include "serialize.h"
@@ -40,36 +40,156 @@
 namespace v8 {
 namespace internal {
 
-MacroAssembler::MacroAssembler(void* buffer, int size)
-    : Assembler(buffer, size),
+MacroAssembler::MacroAssembler(Isolate* arg_isolate, void* buffer, int size)
+    : Assembler(arg_isolate, buffer, size),
       generating_stub_(false),
       allow_stub_calls_(true),
-      code_object_(Heap::undefined_value()) {
+      root_array_available_(true) {
+  if (isolate() != NULL) {
+    code_object_ = Handle<Object>(isolate()->heap()->undefined_value(),
+                                  isolate());
+  }
+}
+
+
+static intptr_t RootRegisterDelta(ExternalReference other, Isolate* isolate) {
+  Address roots_register_value = kRootRegisterBias +
+      reinterpret_cast<Address>(isolate->heap()->roots_address());
+  intptr_t delta = other.address() - roots_register_value;
+  return delta;
+}
+
+
+Operand MacroAssembler::ExternalOperand(ExternalReference target,
+                                        Register scratch) {
+  if (root_array_available_ && !Serializer::enabled()) {
+    intptr_t delta = RootRegisterDelta(target, isolate());
+    if (is_int32(delta)) {
+      Serializer::TooLateToEnableNow();
+      return Operand(kRootRegister, static_cast<int32_t>(delta));
+    }
+  }
+  movq(scratch, target);
+  return Operand(scratch, 0);
+}
+
+
+void MacroAssembler::Load(Register destination, ExternalReference source) {
+  if (root_array_available_ && !Serializer::enabled()) {
+    intptr_t delta = RootRegisterDelta(source, isolate());
+    if (is_int32(delta)) {
+      Serializer::TooLateToEnableNow();
+      movq(destination, Operand(kRootRegister, static_cast<int32_t>(delta)));
+      return;
+    }
+  }
+  // Safe code.
+  if (destination.is(rax)) {
+    load_rax(source);
+  } else {
+    movq(kScratchRegister, source);
+    movq(destination, Operand(kScratchRegister, 0));
+  }
+}
+
+
+void MacroAssembler::Store(ExternalReference destination, Register source) {
+  if (root_array_available_ && !Serializer::enabled()) {
+    intptr_t delta = RootRegisterDelta(destination, isolate());
+    if (is_int32(delta)) {
+      Serializer::TooLateToEnableNow();
+      movq(Operand(kRootRegister, static_cast<int32_t>(delta)), source);
+      return;
+    }
+  }
+  // Safe code.
+  if (source.is(rax)) {
+    store_rax(destination);
+  } else {
+    movq(kScratchRegister, destination);
+    movq(Operand(kScratchRegister, 0), source);
+  }
+}
+
+
+void MacroAssembler::LoadAddress(Register destination,
+                                 ExternalReference source) {
+  if (root_array_available_ && !Serializer::enabled()) {
+    intptr_t delta = RootRegisterDelta(source, isolate());
+    if (is_int32(delta)) {
+      Serializer::TooLateToEnableNow();
+      lea(destination, Operand(kRootRegister, static_cast<int32_t>(delta)));
+      return;
+    }
+  }
+  // Safe code.
+  movq(destination, source);
+}
+
+
+int MacroAssembler::LoadAddressSize(ExternalReference source) {
+  if (root_array_available_ && !Serializer::enabled()) {
+    // This calculation depends on the internals of LoadAddress.
+    // It's correctness is ensured by the asserts in the Call
+    // instruction below.
+    intptr_t delta = RootRegisterDelta(source, isolate());
+    if (is_int32(delta)) {
+      Serializer::TooLateToEnableNow();
+      // Operand is lea(scratch, Operand(kRootRegister, delta));
+      // Opcodes : REX.W 8D ModRM Disp8/Disp32  - 4 or 7.
+      int size = 4;
+      if (!is_int8(static_cast<int32_t>(delta))) {
+        size += 3;  // Need full four-byte displacement in lea.
+      }
+      return size;
+    }
+  }
+  // Size of movq(destination, src);
+  return 10;
 }
 
 
 void MacroAssembler::LoadRoot(Register destination, Heap::RootListIndex index) {
-  movq(destination, Operand(kRootRegister, index << kPointerSizeLog2));
+  ASSERT(root_array_available_);
+  movq(destination, Operand(kRootRegister,
+                            (index << kPointerSizeLog2) - kRootRegisterBias));
+}
+
+
+void MacroAssembler::LoadRootIndexed(Register destination,
+                                     Register variable_offset,
+                                     int fixed_offset) {
+  ASSERT(root_array_available_);
+  movq(destination,
+       Operand(kRootRegister,
+               variable_offset, times_pointer_size,
+               (fixed_offset << kPointerSizeLog2) - kRootRegisterBias));
 }
 
 
 void MacroAssembler::StoreRoot(Register source, Heap::RootListIndex index) {
-  movq(Operand(kRootRegister, index << kPointerSizeLog2), source);
+  ASSERT(root_array_available_);
+  movq(Operand(kRootRegister, (index << kPointerSizeLog2) - kRootRegisterBias),
+       source);
 }
 
 
 void MacroAssembler::PushRoot(Heap::RootListIndex index) {
-  push(Operand(kRootRegister, index << kPointerSizeLog2));
+  ASSERT(root_array_available_);
+  push(Operand(kRootRegister, (index << kPointerSizeLog2) - kRootRegisterBias));
 }
 
 
 void MacroAssembler::CompareRoot(Register with, Heap::RootListIndex index) {
-  cmpq(with, Operand(kRootRegister, index << kPointerSizeLog2));
+  ASSERT(root_array_available_);
+  cmpq(with, Operand(kRootRegister,
+                     (index << kPointerSizeLog2) - kRootRegisterBias));
 }
 
 
 void MacroAssembler::CompareRoot(const Operand& with,
                                  Heap::RootListIndex index) {
+  ASSERT(root_array_available_);
   ASSERT(!with.AddressUsesRegister(kScratchRegister));
   LoadRoot(kScratchRegister, index);
   cmpq(with, kScratchRegister);
@@ -79,10 +199,10 @@ void MacroAssembler::CompareRoot(const Operand& with,
 void MacroAssembler::RecordWriteHelper(Register object,
                                        Register addr,
                                        Register scratch) {
-  if (FLAG_debug_code) {
+  if (emit_debug_code()) {
     // Check that the object is not in new space.
-    NearLabel not_in_new_space;
-    InNewSpace(object, scratch, not_equal, &not_in_new_space);
+    Label not_in_new_space;
+    InNewSpace(object, scratch, not_equal, &not_in_new_space, Label::kNear);
     Abort("new-space object passed to RecordWriteHelper");
     bind(&not_in_new_space);
   }
@@ -101,6 +221,42 @@ void MacroAssembler::RecordWriteHelper(Register object,
 }
 
 
+void MacroAssembler::InNewSpace(Register object,
+                                Register scratch,
+                                Condition cc,
+                                Label* branch,
+                                Label::Distance near_jump) {
+  if (Serializer::enabled()) {
+    // Can't do arithmetic on external references if it might get serialized.
+    // The mask isn't really an address.  We load it as an external reference in
+    // case the size of the new space is different between the snapshot maker
+    // and the running system.
+    if (scratch.is(object)) {
+      movq(kScratchRegister, ExternalReference::new_space_mask(isolate()));
+      and_(scratch, kScratchRegister);
+    } else {
+      movq(scratch, ExternalReference::new_space_mask(isolate()));
+      and_(scratch, object);
+    }
+    movq(kScratchRegister, ExternalReference::new_space_start(isolate()));
+    cmpq(scratch, kScratchRegister);
+    j(cc, branch, near_jump);
+  } else {
+    ASSERT(is_int32(static_cast<int64_t>(HEAP->NewSpaceMask())));
+    intptr_t new_space_start =
+        reinterpret_cast<intptr_t>(HEAP->NewSpaceStart());
+    movq(kScratchRegister, -new_space_start, RelocInfo::NONE);
+    if (scratch.is(object)) {
+      addq(scratch, kScratchRegister);
+    } else {
+      lea(scratch, Operand(object, kScratchRegister, times_1, 0));
+    }
+    and_(scratch, Immediate(static_cast<int32_t>(HEAP->NewSpaceMask())));
+    j(cc, branch, near_jump);
+  }
+}
+
+
 void MacroAssembler::RecordWrite(Register object,
                                  int offset,
                                  Register value,
@@ -111,7 +267,7 @@ void MacroAssembler::RecordWrite(Register object,
   ASSERT(!object.is(rsi) && !value.is(rsi) && !index.is(rsi));
 
   // First, check if a write barrier is even needed. The tests below
-  // catch stores of Smis and stores into young gen.
+  // catch stores of smis and stores into the young generation.
   Label done;
   JumpIfSmi(value, &done);
 
@@ -123,7 +279,7 @@ void MacroAssembler::RecordWrite(Register object,
   // clobbering done inside RecordWriteNonSmi but it's necessary to
   // avoid having the fast case for smis leave the registers
   // unchanged.
-  if (FLAG_debug_code) {
+  if (emit_debug_code()) {
     movq(object, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
     movq(value, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
     movq(index, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
@@ -140,7 +296,7 @@ void MacroAssembler::RecordWrite(Register object,
   ASSERT(!object.is(rsi) && !value.is(rsi) && !address.is(rsi));
 
   // First, check if a write barrier is even needed. The tests below
-  // catch stores of Smis and stores into young gen.
+  // catch stores of smis and stores into the young generation.
   Label done;
   JumpIfSmi(value, &done);
 
@@ -152,7 +308,7 @@ void MacroAssembler::RecordWrite(Register object,
 
   // Clobber all input registers when running with the debug-code flag
   // turned on to provoke errors.
-  if (FLAG_debug_code) {
+  if (emit_debug_code()) {
     movq(object, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
     movq(address, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
     movq(value, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
@@ -166,9 +322,9 @@ void MacroAssembler::RecordWriteNonSmi(Register object,
                                        Register index) {
   Label done;
 
-  if (FLAG_debug_code) {
-    NearLabel okay;
-    JumpIfNotSmi(object, &okay);
+  if (emit_debug_code()) {
+    Label okay;
+    JumpIfNotSmi(object, &okay, Label::kNear);
     Abort("MacroAssembler::RecordWriteNonSmi cannot deal with smis");
     bind(&okay);
 
@@ -210,7 +366,7 @@ void MacroAssembler::RecordWriteNonSmi(Register object,
 
   // Clobber all input registers when running with the debug-code flag
   // turned on to provoke errors.
-  if (FLAG_debug_code) {
+  if (emit_debug_code()) {
     movq(object, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
     movq(scratch, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
     movq(index, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
@@ -218,19 +374,19 @@ void MacroAssembler::RecordWriteNonSmi(Register object,
 }
 
 void MacroAssembler::Assert(Condition cc, const char* msg) {
-  if (FLAG_debug_code) Check(cc, msg);
+  if (emit_debug_code()) Check(cc, msg);
 }
 
 
 void MacroAssembler::AssertFastElements(Register elements) {
-  if (FLAG_debug_code) {
-    NearLabel ok;
+  if (emit_debug_code()) {
+    Label ok;
     CompareRoot(FieldOperand(elements, HeapObject::kMapOffset),
                 Heap::kFixedArrayMapRootIndex);
-    j(equal, &ok);
+    j(equal, &ok, Label::kNear);
     CompareRoot(FieldOperand(elements, HeapObject::kMapOffset),
                 Heap::kFixedCOWArrayMapRootIndex);
-    j(equal, &ok);
+    j(equal, &ok, Label::kNear);
     Abort("JSObject with fast elements map has slow elements");
     bind(&ok);
   }
@@ -238,8 +394,8 @@ void MacroAssembler::AssertFastElements(Register elements) {
 
 
 void MacroAssembler::Check(Condition cc, const char* msg) {
-  NearLabel L;
-  j(cc, &L);
+  Label L;
+  j(cc, &L, Label::kNear);
   Abort(msg);
   // will not return here
   bind(&L);
@@ -251,9 +407,9 @@ void MacroAssembler::CheckStackAlignment() {
   int frame_alignment_mask = frame_alignment - 1;
   if (frame_alignment > kPointerSize) {
     ASSERT(IsPowerOf2(frame_alignment));
-    NearLabel alignment_as_expected;
+    Label alignment_as_expected;
     testq(rsp, Immediate(frame_alignment_mask));
-    j(zero, &alignment_as_expected);
+    j(zero, &alignment_as_expected, Label::kNear);
     // Abort if stack is not aligned.
     int3();
     bind(&alignment_as_expected);
@@ -264,9 +420,9 @@ void MacroAssembler::CheckStackAlignment() {
 void MacroAssembler::NegativeZeroTest(Register result,
                                       Register op,
                                       Label* then_label) {
-  NearLabel ok;
+  Label ok;
   testl(result, result);
-  j(not_zero, &ok);
+  j(not_zero, &ok, Label::kNear);
   testl(op, op);
   j(sign, then_label);
   bind(&ok);
@@ -305,9 +461,9 @@ void MacroAssembler::Abort(const char* msg) {
 }
 
 
-void MacroAssembler::CallStub(CodeStub* stub) {
+void MacroAssembler::CallStub(CodeStub* stub, unsigned ast_id) {
   ASSERT(allow_stub_calls());  // calls are not allowed in some stubs
-  Call(stub->GetCode(), RelocInfo::CODE_TARGET);
+  Call(stub->GetCode(), RelocInfo::CODE_TARGET, ast_id);
 }
 
 
@@ -378,9 +534,9 @@ void MacroAssembler::CallRuntime(Runtime::FunctionId id, int num_arguments) {
 
 
 void MacroAssembler::CallRuntimeSaveDoubles(Runtime::FunctionId id) {
-  Runtime::Function* function = Runtime::FunctionForId(id);
+  const Runtime::Function* function = Runtime::FunctionForId(id);
   Set(rax, function->nargs);
-  movq(rbx, ExternalReference(function));
+  LoadAddress(rbx, ExternalReference(function, isolate()));
   CEntryStub ces(1);
   ces.SaveDoubles();
   CallStub(&ces);
@@ -393,7 +549,8 @@ MaybeObject* MacroAssembler::TryCallRuntime(Runtime::FunctionId id,
 }
 
 
-void MacroAssembler::CallRuntime(Runtime::Function* f, int num_arguments) {
+void MacroAssembler::CallRuntime(const Runtime::Function* f,
+                                 int num_arguments) {
   // If the expected number of arguments of the runtime function is
   // constant, we check that the actual number of arguments match the
   // expectation.
@@ -407,19 +564,19 @@ void MacroAssembler::CallRuntime(Runtime::Function* f, int num_arguments) {
   // should remove this need and make the runtime routine entry code
   // smarter.
   Set(rax, num_arguments);
-  movq(rbx, ExternalReference(f));
+  LoadAddress(rbx, ExternalReference(f, isolate()));
   CEntryStub ces(f->result_size);
   CallStub(&ces);
 }
 
 
-MaybeObject* MacroAssembler::TryCallRuntime(Runtime::Function* f,
+MaybeObject* MacroAssembler::TryCallRuntime(const Runtime::Function* f,
                                             int num_arguments) {
   if (f->nargs >= 0 && f->nargs != num_arguments) {
     IllegalOperation(num_arguments);
     // Since we did not call the stub, there was no allocation failure.
     // Return some non-failure object.
-    return Heap::undefined_value();
+    return HEAP->undefined_value();
   }
 
   // TODO(1236192): Most runtime routines don't need the number of
@@ -427,7 +584,7 @@ MaybeObject* MacroAssembler::TryCallRuntime(Runtime::Function* f,
   // should remove this need and make the runtime routine entry code
   // smarter.
   Set(rax, num_arguments);
-  movq(rbx, ExternalReference(f));
+  LoadAddress(rbx, ExternalReference(f, isolate()));
   CEntryStub ces(f->result_size);
   return TryCallStub(&ces);
 }
@@ -436,7 +593,7 @@ MaybeObject* MacroAssembler::TryCallRuntime(Runtime::Function* f,
 void MacroAssembler::CallExternalReference(const ExternalReference& ext,
                                            int num_arguments) {
   Set(rax, num_arguments);
-  movq(rbx, ext);
+  LoadAddress(rbx, ext);
 
   CEntryStub stub(1);
   CallStub(&stub);
@@ -483,14 +640,16 @@ MaybeObject* MacroAssembler::TryTailCallExternalReference(
 void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid,
                                      int num_arguments,
                                      int result_size) {
-  TailCallExternalReference(ExternalReference(fid), num_arguments, result_size);
+  TailCallExternalReference(ExternalReference(fid, isolate()),
+                            num_arguments,
+                            result_size);
 }
 
 
 MaybeObject* MacroAssembler::TryTailCallRuntime(Runtime::FunctionId fid,
                                                 int num_arguments,
                                                 int result_size) {
-  return TryTailCallExternalReference(ExternalReference(fid),
+  return TryTailCallExternalReference(ExternalReference(fid, isolate()),
                                       num_arguments,
                                       result_size);
 }
@@ -527,6 +686,7 @@ MaybeObject* MacroAssembler::TryCallApiFunctionAndReturn(
   Label leave_exit_frame;
   Label write_back;
 
+  Factory* factory = isolate()->factory();
   ExternalReference next_address =
       ExternalReference::handle_scope_next_address();
   const int kNextOffset = 0;
@@ -537,12 +697,12 @@ MaybeObject* MacroAssembler::TryCallApiFunctionAndReturn(
       ExternalReference::handle_scope_level_address(),
       next_address);
   ExternalReference scheduled_exception_address =
-      ExternalReference::scheduled_exception_address();
+      ExternalReference::scheduled_exception_address(isolate());
 
   // Allocate HandleScope in callee-save registers.
   Register prev_next_address_reg = r14;
   Register prev_limit_reg = rbx;
-  Register base_reg = r12;
+  Register base_reg = r15;
   movq(base_reg, next_address);
   movq(prev_next_address_reg, Operand(base_reg, kNextOffset));
   movq(prev_limit_reg, Operand(base_reg, kLimitOffset));
@@ -574,7 +734,7 @@ MaybeObject* MacroAssembler::TryCallApiFunctionAndReturn(
 
   // Check if the function scheduled an exception.
   movq(rsi, scheduled_exception_address);
-  Cmp(Operand(rsi, 0), Factory::the_hole_value());
+  Cmp(Operand(rsi, 0), factory->the_hole_value());
   j(not_equal, &promote_scheduled_exception);
 
   LeaveApiExitFrame();
@@ -589,14 +749,20 @@ MaybeObject* MacroAssembler::TryCallApiFunctionAndReturn(
 
   bind(&empty_result);
   // It was zero; the result is undefined.
-  Move(rax, Factory::undefined_value());
+  Move(rax, factory->undefined_value());
   jmp(&prologue);
 
   // HandleScope limit has changed. Delete allocated extensions.
   bind(&delete_allocated_handles);
   movq(Operand(base_reg, kLimitOffset), prev_limit_reg);
   movq(prev_limit_reg, rax);
-  movq(rax, ExternalReference::delete_handle_scope_extensions());
+#ifdef _WIN64
+  LoadAddress(rcx, ExternalReference::isolate_address());
+#else
+  LoadAddress(rdi, ExternalReference::isolate_address());
+#endif
+  LoadAddress(rax,
+              ExternalReference::delete_handle_scope_extensions(isolate()));
   call(rax);
   movq(rax, prev_limit_reg);
   jmp(&leave_exit_frame);
@@ -608,7 +774,7 @@ MaybeObject* MacroAssembler::TryCallApiFunctionAndReturn(
 void MacroAssembler::JumpToExternalReference(const ExternalReference& ext,
                                              int result_size) {
   // Set the entry point and jump to the C entry runtime stub.
-  movq(rbx, ext);
+  LoadAddress(rbx, ext);
   CEntryStub ces(result_size);
   jmp(ces.GetCode(), RelocInfo::CODE_TARGET);
 }
@@ -617,7 +783,7 @@ void MacroAssembler::JumpToExternalReference(const ExternalReference& ext,
 MaybeObject* MacroAssembler::TryJumpToExternalReference(
     const ExternalReference& ext, int result_size) {
   // Set the entry point and jump to the C entry runtime stub.
-  movq(rbx, ext);
+  LoadAddress(rbx, ext);
   CEntryStub ces(result_size);
   return TryTailCallStub(&ces);
 }
@@ -625,7 +791,7 @@ MaybeObject* MacroAssembler::TryJumpToExternalReference(
 
 void MacroAssembler::InvokeBuiltin(Builtins::JavaScript id,
                                    InvokeFlag flag,
-                                   PostCallGenerator* post_call_generator) {
+                                   const CallWrapper& call_wrapper) {
   // Calls are not allowed in some stubs.
   ASSERT(flag == JUMP_FUNCTION || allow_stub_calls());
 
@@ -634,7 +800,7 @@ void MacroAssembler::InvokeBuiltin(Builtins::JavaScript id,
   // parameter count to avoid emitting code to do the check.
   ParameterCount expected(0);
   GetBuiltinEntry(rdx, id);
-  InvokeCode(rdx, expected, expected, flag, post_call_generator);
+  InvokeCode(rdx, expected, expected, flag, call_wrapper, CALL_AS_METHOD);
 }
 
 
@@ -659,10 +825,10 @@ void MacroAssembler::GetBuiltinEntry(Register target, Builtins::JavaScript id) {
 void MacroAssembler::Set(Register dst, int64_t x) {
   if (x == 0) {
     xorl(dst, dst);
-  } else if (is_int32(x)) {
-    movq(dst, Immediate(static_cast<int32_t>(x)));
   } 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, RelocInfo::NONE);
   }
@@ -672,7 +838,7 @@ void MacroAssembler::Set(const Operand& dst, int64_t x) {
   if (is_int32(x)) {
     movq(dst, Immediate(static_cast<int32_t>(x)));
   } else {
-    movq(kScratchRegister, x, RelocInfo::NONE);
+    Set(kScratchRegister, x);
     movq(dst, kScratchRegister);
   }
 }
@@ -694,7 +860,7 @@ Register MacroAssembler::GetSmiConstant(Smi* source) {
 }
 
 void MacroAssembler::LoadSmiConstant(Register dst, Smi* source) {
-  if (FLAG_debug_code) {
+  if (emit_debug_code()) {
     movq(dst,
          reinterpret_cast<uint64_t>(Smi::FromInt(kSmiConstantRegisterValue)),
          RelocInfo::NONE);
@@ -702,17 +868,17 @@ void MacroAssembler::LoadSmiConstant(Register dst, Smi* source) {
     if (allow_stub_calls()) {
       Assert(equal, "Uninitialized kSmiConstantRegister");
     } else {
-      NearLabel ok;
-      j(equal, &ok);
+      Label ok;
+      j(equal, &ok, Label::kNear);
       int3();
       bind(&ok);
     }
   }
-  if (source->value() == 0) {
+  int value = source->value();
+  if (value == 0) {
     xorl(dst, dst);
     return;
   }
-  int value = source->value();
   bool negative = value < 0;
   unsigned int uvalue = negative ? -value : value;
 
@@ -763,10 +929,10 @@ void MacroAssembler::Integer32ToSmi(Register dst, Register src) {
 
 
 void MacroAssembler::Integer32ToSmiField(const Operand& dst, Register src) {
-  if (FLAG_debug_code) {
+  if (emit_debug_code()) {
     testb(dst, Immediate(0x01));
-    NearLabel ok;
-    j(zero, &ok);
+    Label ok;
+    j(zero, &ok, Label::kNear);
     if (allow_stub_calls()) {
       Abort("Integer32ToSmiField writing to non-smi location");
     } else {
@@ -783,9 +949,9 @@ void MacroAssembler::Integer64PlusConstantToSmi(Register dst,
                                                 Register src,
                                                 int constant) {
   if (dst.is(src)) {
-    addq(dst, Immediate(constant));
+    addl(dst, Immediate(constant));
   } else {
-    lea(dst, Operand(src, constant));
+    leal(dst, Operand(src, constant));
   }
   shl(dst, Immediate(kSmiShift));
 }
@@ -824,12 +990,24 @@ void MacroAssembler::SmiTest(Register src) {
 }
 
 
-void MacroAssembler::SmiCompare(Register dst, Register src) {
-  cmpq(dst, src);
+void MacroAssembler::SmiCompare(Register smi1, Register smi2) {
+  if (emit_debug_code()) {
+    AbortIfNotSmi(smi1);
+    AbortIfNotSmi(smi2);
+  }
+  cmpq(smi1, smi2);
 }
 
 
 void MacroAssembler::SmiCompare(Register dst, Smi* src) {
+  if (emit_debug_code()) {
+    AbortIfNotSmi(dst);
+  }
+  Cmp(dst, src);
+}
+
+
+void MacroAssembler::Cmp(Register dst, Smi* src) {
   ASSERT(!dst.is(kScratchRegister));
   if (src->value() == 0) {
     testq(dst, dst);
@@ -841,20 +1019,39 @@ void MacroAssembler::SmiCompare(Register dst, Smi* src) {
 
 
 void MacroAssembler::SmiCompare(Register dst, const Operand& src) {
+  if (emit_debug_code()) {
+    AbortIfNotSmi(dst);
+    AbortIfNotSmi(src);
+  }
   cmpq(dst, src);
 }
 
 
 void MacroAssembler::SmiCompare(const Operand& dst, Register src) {
+  if (emit_debug_code()) {
+    AbortIfNotSmi(dst);
+    AbortIfNotSmi(src);
+  }
   cmpq(dst, src);
 }
 
 
 void MacroAssembler::SmiCompare(const Operand& dst, Smi* src) {
+  if (emit_debug_code()) {
+    AbortIfNotSmi(dst);
+  }
   cmpl(Operand(dst, kSmiShift / kBitsPerByte), Immediate(src->value()));
 }
 
 
+void MacroAssembler::Cmp(const Operand& dst, Smi* src) {
+  // The Operand cannot use the smi register.
+  Register smi_reg = GetSmiConstant(src);
+  ASSERT(!dst.AddressUsesRegister(smi_reg));
+  cmpq(dst, smi_reg);
+}
+
+
 void MacroAssembler::SmiCompareInteger32(const Operand& dst, Register src) {
   cmpl(Operand(dst, kSmiShift / kBitsPerByte), src);
 }
@@ -892,6 +1089,24 @@ void MacroAssembler::PositiveSmiDivPowerOfTwoToInteger32(Register dst,
 }
 
 
+void MacroAssembler::SmiOrIfSmis(Register dst, Register src1, Register src2,
+                                 Label* on_not_smis,
+                                 Label::Distance near_jump) {
+  if (dst.is(src1) || dst.is(src2)) {
+    ASSERT(!src1.is(kScratchRegister));
+    ASSERT(!src2.is(kScratchRegister));
+    movq(kScratchRegister, src1);
+    or_(kScratchRegister, src2);
+    JumpIfNotSmi(kScratchRegister, on_not_smis, near_jump);
+    movq(dst, kScratchRegister);
+  } else {
+    movq(dst, src1);
+    or_(dst, src2);
+    JumpIfNotSmi(dst, on_not_smis, near_jump);
+  }
+}
+
+
 Condition MacroAssembler::CheckSmi(Register src) {
   ASSERT_EQ(0, kSmiTag);
   testb(src, Immediate(kSmiTagMask));
@@ -908,7 +1123,7 @@ Condition MacroAssembler::CheckSmi(const Operand& src) {
 
 Condition MacroAssembler::CheckNonNegativeSmi(Register src) {
   ASSERT_EQ(0, kSmiTag);
-  // Make mask 0x8000000000000001 and test that both bits are zero.
+  // Test that both bits of the mask 0x8000000000000001 are zero.
   movq(kScratchRegister, src);
   rol(kScratchRegister, Immediate(1));
   testb(kScratchRegister, Immediate(3));
@@ -1002,6 +1217,95 @@ void MacroAssembler::CheckSmiToIndicator(Register dst, const Operand& src) {
 }
 
 
+void MacroAssembler::JumpIfNotValidSmiValue(Register src,
+                                            Label* on_invalid,
+                                            Label::Distance near_jump) {
+  Condition is_valid = CheckInteger32ValidSmiValue(src);
+  j(NegateCondition(is_valid), on_invalid, near_jump);
+}
+
+
+void MacroAssembler::JumpIfUIntNotValidSmiValue(Register src,
+                                                Label* on_invalid,
+                                                Label::Distance near_jump) {
+  Condition is_valid = CheckUInteger32ValidSmiValue(src);
+  j(NegateCondition(is_valid), on_invalid, near_jump);
+}
+
+
+void MacroAssembler::JumpIfSmi(Register src,
+                               Label* on_smi,
+                               Label::Distance near_jump) {
+  Condition smi = CheckSmi(src);
+  j(smi, on_smi, near_jump);
+}
+
+
+void MacroAssembler::JumpIfNotSmi(Register src,
+                                  Label* on_not_smi,
+                                  Label::Distance near_jump) {
+  Condition smi = CheckSmi(src);
+  j(NegateCondition(smi), on_not_smi, near_jump);
+}
+
+
+void MacroAssembler::JumpUnlessNonNegativeSmi(
+    Register src, Label* on_not_smi_or_negative,
+    Label::Distance near_jump) {
+  Condition non_negative_smi = CheckNonNegativeSmi(src);
+  j(NegateCondition(non_negative_smi), on_not_smi_or_negative, near_jump);
+}
+
+
+void MacroAssembler::JumpIfSmiEqualsConstant(Register src,
+                                             Smi* constant,
+                                             Label* on_equals,
+                                             Label::Distance near_jump) {
+  SmiCompare(src, constant);
+  j(equal, on_equals, near_jump);
+}
+
+
+void MacroAssembler::JumpIfNotBothSmi(Register src1,
+                                      Register src2,
+                                      Label* on_not_both_smi,
+                                      Label::Distance near_jump) {
+  Condition both_smi = CheckBothSmi(src1, src2);
+  j(NegateCondition(both_smi), on_not_both_smi, near_jump);
+}
+
+
+void MacroAssembler::JumpUnlessBothNonNegativeSmi(Register src1,
+                                                  Register src2,
+                                                  Label* on_not_both_smi,
+                                                  Label::Distance near_jump) {
+  Condition both_smi = CheckBothNonNegativeSmi(src1, src2);
+  j(NegateCondition(both_smi), on_not_both_smi, near_jump);
+}
+
+
+void MacroAssembler::SmiTryAddConstant(Register dst,
+                                       Register src,
+                                       Smi* constant,
+                                       Label* on_not_smi_result,
+                                       Label::Distance near_jump) {
+  // Does not assume that src is a smi.
+  ASSERT_EQ(static_cast<int>(1), static_cast<int>(kSmiTagMask));
+  ASSERT_EQ(0, kSmiTag);
+  ASSERT(!dst.is(kScratchRegister));
+  ASSERT(!src.is(kScratchRegister));
+
+  JumpIfNotSmi(src, on_not_smi_result, near_jump);
+  Register tmp = (dst.is(src) ? kScratchRegister : dst);
+  LoadSmiConstant(tmp, constant);
+  addq(tmp, src);
+  j(overflow, on_not_smi_result, near_jump);
+  if (dst.is(src)) {
+    movq(dst, tmp);
+  }
+}
+
+
 void MacroAssembler::SmiAddConstant(Register dst, Register src, Smi* constant) {
   if (constant->value() == 0) {
     if (!dst.is(src)) {
@@ -1058,6 +1362,30 @@ void MacroAssembler::SmiAddConstant(const Operand& dst, Smi* constant) {
 }
 
 
+void MacroAssembler::SmiAddConstant(Register dst,
+                                    Register src,
+                                    Smi* constant,
+                                    Label* on_not_smi_result,
+                                    Label::Distance near_jump) {
+  if (constant->value() == 0) {
+    if (!dst.is(src)) {
+      movq(dst, src);
+    }
+  } else if (dst.is(src)) {
+    ASSERT(!dst.is(kScratchRegister));
+
+    LoadSmiConstant(kScratchRegister, constant);
+    addq(kScratchRegister, src);
+    j(overflow, on_not_smi_result, near_jump);
+    movq(dst, kScratchRegister);
+  } else {
+    LoadSmiConstant(dst, constant);
+    addq(dst, src);
+    j(overflow, on_not_smi_result, near_jump);
+  }
+}
+
+
 void MacroAssembler::SmiSubConstant(Register dst, Register src, Smi* constant) {
   if (constant->value() == 0) {
     if (!dst.is(src)) {
@@ -1082,19 +1410,148 @@ void MacroAssembler::SmiSubConstant(Register dst, Register src, Smi* constant) {
 }
 
 
+void MacroAssembler::SmiSubConstant(Register dst,
+                                    Register src,
+                                    Smi* constant,
+                                    Label* on_not_smi_result,
+                                    Label::Distance near_jump) {
+  if (constant->value() == 0) {
+    if (!dst.is(src)) {
+      movq(dst, src);
+    }
+  } else if (dst.is(src)) {
+    ASSERT(!dst.is(kScratchRegister));
+    if (constant->value() == Smi::kMinValue) {
+      // Subtracting min-value from any non-negative value will overflow.
+      // We test the non-negativeness before doing the subtraction.
+      testq(src, src);
+      j(not_sign, on_not_smi_result, near_jump);
+      LoadSmiConstant(kScratchRegister, constant);
+      subq(dst, kScratchRegister);
+    } else {
+      // Subtract by adding the negation.
+      LoadSmiConstant(kScratchRegister, Smi::FromInt(-constant->value()));
+      addq(kScratchRegister, dst);
+      j(overflow, on_not_smi_result, near_jump);
+      movq(dst, kScratchRegister);
+    }
+  } else {
+    if (constant->value() == Smi::kMinValue) {
+      // Subtracting min-value from any non-negative value will overflow.
+      // We test the non-negativeness before doing the subtraction.
+      testq(src, src);
+      j(not_sign, on_not_smi_result, near_jump);
+      LoadSmiConstant(dst, constant);
+      // Adding and subtracting the min-value gives the same result, it only
+      // differs on the overflow bit, which we don't check here.
+      addq(dst, src);
+    } else {
+      // Subtract by adding the negation.
+      LoadSmiConstant(dst, Smi::FromInt(-(constant->value())));
+      addq(dst, src);
+      j(overflow, on_not_smi_result, near_jump);
+    }
+  }
+}
+
+
+void MacroAssembler::SmiNeg(Register dst,
+                            Register src,
+                            Label* on_smi_result,
+                            Label::Distance near_jump) {
+  if (dst.is(src)) {
+    ASSERT(!dst.is(kScratchRegister));
+    movq(kScratchRegister, src);
+    neg(dst);  // Low 32 bits are retained as zero by negation.
+    // Test if result is zero or Smi::kMinValue.
+    cmpq(dst, kScratchRegister);
+    j(not_equal, on_smi_result, near_jump);
+    movq(src, kScratchRegister);
+  } else {
+    movq(dst, src);
+    neg(dst);
+    cmpq(dst, src);
+    // If the result is zero or Smi::kMinValue, negation failed to create a smi.
+    j(not_equal, on_smi_result, near_jump);
+  }
+}
+
+
+void MacroAssembler::SmiAdd(Register dst,
+                            Register src1,
+                            Register src2,
+                            Label* on_not_smi_result,
+                            Label::Distance near_jump) {
+  ASSERT_NOT_NULL(on_not_smi_result);
+  ASSERT(!dst.is(src2));
+  if (dst.is(src1)) {
+    movq(kScratchRegister, src1);
+    addq(kScratchRegister, src2);
+    j(overflow, on_not_smi_result, near_jump);
+    movq(dst, kScratchRegister);
+  } else {
+    movq(dst, src1);
+    addq(dst, src2);
+    j(overflow, on_not_smi_result, near_jump);
+  }
+}
+
+
+void MacroAssembler::SmiAdd(Register dst,
+                            Register src1,
+                            const Operand& src2,
+                            Label* on_not_smi_result,
+                            Label::Distance near_jump) {
+  ASSERT_NOT_NULL(on_not_smi_result);
+  if (dst.is(src1)) {
+    movq(kScratchRegister, src1);
+    addq(kScratchRegister, src2);
+    j(overflow, on_not_smi_result, near_jump);
+    movq(dst, kScratchRegister);
+  } else {
+    ASSERT(!src2.AddressUsesRegister(dst));
+    movq(dst, src1);
+    addq(dst, src2);
+    j(overflow, on_not_smi_result, near_jump);
+  }
+}
+
+
 void MacroAssembler::SmiAdd(Register dst,
                             Register src1,
                             Register src2) {
   // No overflow checking. Use only when it's known that
   // overflowing is impossible.
+  if (!dst.is(src1)) {
+    if (emit_debug_code()) {
+      movq(kScratchRegister, src1);
+      addq(kScratchRegister, src2);
+      Check(no_overflow, "Smi addition overflow");
+    }
+    lea(dst, Operand(src1, src2, times_1, 0));
+  } else {
+    addq(dst, src2);
+    Assert(no_overflow, "Smi addition overflow");
+  }
+}
+
+
+void MacroAssembler::SmiSub(Register dst,
+                            Register src1,
+                            Register src2,
+                            Label* on_not_smi_result,
+                            Label::Distance near_jump) {
+  ASSERT_NOT_NULL(on_not_smi_result);
   ASSERT(!dst.is(src2));
   if (dst.is(src1)) {
-    addq(dst, src2);
+    cmpq(dst, src2);
+    j(overflow, on_not_smi_result, near_jump);
+    subq(dst, src2);
   } else {
     movq(dst, src1);
-    addq(dst, src2);
+    subq(dst, src2);
+    j(overflow, on_not_smi_result, near_jump);
   }
-  Assert(no_overflow, "Smi addition overflow");
 }
 
 
@@ -1102,13 +1559,30 @@ void MacroAssembler::SmiSub(Register dst, Register src1, Register src2) {
   // No overflow checking. Use only when it's known that
   // overflowing is impossible (e.g., subtracting two positive smis).
   ASSERT(!dst.is(src2));
+  if (!dst.is(src1)) {
+    movq(dst, src1);
+  }
+  subq(dst, src2);
+  Assert(no_overflow, "Smi subtraction overflow");
+}
+
+
+void MacroAssembler::SmiSub(Register dst,
+                            Register src1,
+                            const Operand& src2,
+                            Label* on_not_smi_result,
+                            Label::Distance near_jump) {
+  ASSERT_NOT_NULL(on_not_smi_result);
   if (dst.is(src1)) {
-    subq(dst, src2);
+    movq(kScratchRegister, src2);
+    cmpq(src1, kScratchRegister);
+    j(overflow, on_not_smi_result, near_jump);
+    subq(src1, kScratchRegister);
   } else {
     movq(dst, src1);
     subq(dst, src2);
+    j(overflow, on_not_smi_result, near_jump);
   }
-  Assert(no_overflow, "Smi subtraction overflow");
 }
 
 
@@ -1117,16 +1591,188 @@ void MacroAssembler::SmiSub(Register dst,
                             const Operand& src2) {
   // No overflow checking. Use only when it's known that
   // overflowing is impossible (e.g., subtracting two positive smis).
-  if (dst.is(src1)) {
-    subq(dst, src2);
-  } else {
+  if (!dst.is(src1)) {
     movq(dst, src1);
-    subq(dst, src2);
   }
+  subq(dst, src2);
   Assert(no_overflow, "Smi subtraction overflow");
 }
 
 
+void MacroAssembler::SmiMul(Register dst,
+                            Register src1,
+                            Register src2,
+                            Label* on_not_smi_result,
+                            Label::Distance near_jump) {
+  ASSERT(!dst.is(src2));
+  ASSERT(!dst.is(kScratchRegister));
+  ASSERT(!src1.is(kScratchRegister));
+  ASSERT(!src2.is(kScratchRegister));
+
+  if (dst.is(src1)) {
+    Label failure, zero_correct_result;
+    movq(kScratchRegister, src1);  // Create backup for later testing.
+    SmiToInteger64(dst, src1);
+    imul(dst, src2);
+    j(overflow, &failure, Label::kNear);
+
+    // Check for negative zero result.  If product is zero, and one
+    // argument is negative, go to slow case.
+    Label correct_result;
+    testq(dst, dst);
+    j(not_zero, &correct_result, Label::kNear);
+
+    movq(dst, kScratchRegister);
+    xor_(dst, src2);
+    // Result was positive zero.
+    j(positive, &zero_correct_result, Label::kNear);
+
+    bind(&failure);  // Reused failure exit, restores src1.
+    movq(src1, kScratchRegister);
+    jmp(on_not_smi_result, near_jump);
+
+    bind(&zero_correct_result);
+    Set(dst, 0);
+
+    bind(&correct_result);
+  } else {
+    SmiToInteger64(dst, src1);
+    imul(dst, src2);
+    j(overflow, on_not_smi_result, near_jump);
+    // Check for negative zero result.  If product is zero, and one
+    // argument is negative, go to slow case.
+    Label correct_result;
+    testq(dst, dst);
+    j(not_zero, &correct_result, Label::kNear);
+    // One of src1 and src2 is zero, the check whether the other is
+    // negative.
+    movq(kScratchRegister, src1);
+    xor_(kScratchRegister, src2);
+    j(negative, on_not_smi_result, near_jump);
+    bind(&correct_result);
+  }
+}
+
+
+void MacroAssembler::SmiDiv(Register dst,
+                            Register src1,
+                            Register src2,
+                            Label* on_not_smi_result,
+                            Label::Distance near_jump) {
+  ASSERT(!src1.is(kScratchRegister));
+  ASSERT(!src2.is(kScratchRegister));
+  ASSERT(!dst.is(kScratchRegister));
+  ASSERT(!src2.is(rax));
+  ASSERT(!src2.is(rdx));
+  ASSERT(!src1.is(rdx));
+
+  // Check for 0 divisor (result is +/-Infinity).
+  testq(src2, src2);
+  j(zero, on_not_smi_result, near_jump);
+
+  if (src1.is(rax)) {
+    movq(kScratchRegister, src1);
+  }
+  SmiToInteger32(rax, src1);
+  // We need to rule out dividing Smi::kMinValue by -1, since that would
+  // overflow in idiv and raise an exception.
+  // We combine this with negative zero test (negative zero only happens
+  // when dividing zero by a negative number).
+
+  // We overshoot a little and go to slow case if we divide min-value
+  // by any negative value, not just -1.
+  Label safe_div;
+  testl(rax, Immediate(0x7fffffff));
+  j(not_zero, &safe_div, Label::kNear);
+  testq(src2, src2);
+  if (src1.is(rax)) {
+    j(positive, &safe_div, Label::kNear);
+    movq(src1, kScratchRegister);
+    jmp(on_not_smi_result, near_jump);
+  } else {
+    j(negative, on_not_smi_result, near_jump);
+  }
+  bind(&safe_div);
+
+  SmiToInteger32(src2, src2);
+  // Sign extend src1 into edx:eax.
+  cdq();
+  idivl(src2);
+  Integer32ToSmi(src2, src2);
+  // Check that the remainder is zero.
+  testl(rdx, rdx);
+  if (src1.is(rax)) {
+    Label smi_result;
+    j(zero, &smi_result, Label::kNear);
+    movq(src1, kScratchRegister);
+    jmp(on_not_smi_result, near_jump);
+    bind(&smi_result);
+  } else {
+    j(not_zero, on_not_smi_result, near_jump);
+  }
+  if (!dst.is(src1) && src1.is(rax)) {
+    movq(src1, kScratchRegister);
+  }
+  Integer32ToSmi(dst, rax);
+}
+
+
+void MacroAssembler::SmiMod(Register dst,
+                            Register src1,
+                            Register src2,
+                            Label* on_not_smi_result,
+                            Label::Distance near_jump) {
+  ASSERT(!dst.is(kScratchRegister));
+  ASSERT(!src1.is(kScratchRegister));
+  ASSERT(!src2.is(kScratchRegister));
+  ASSERT(!src2.is(rax));
+  ASSERT(!src2.is(rdx));
+  ASSERT(!src1.is(rdx));
+  ASSERT(!src1.is(src2));
+
+  testq(src2, src2);
+  j(zero, on_not_smi_result, near_jump);
+
+  if (src1.is(rax)) {
+    movq(kScratchRegister, src1);
+  }
+  SmiToInteger32(rax, src1);
+  SmiToInteger32(src2, src2);
+
+  // Test for the edge case of dividing Smi::kMinValue by -1 (will overflow).
+  Label safe_div;
+  cmpl(rax, Immediate(Smi::kMinValue));
+  j(not_equal, &safe_div, Label::kNear);
+  cmpl(src2, Immediate(-1));
+  j(not_equal, &safe_div, Label::kNear);
+  // Retag inputs and go slow case.
+  Integer32ToSmi(src2, src2);
+  if (src1.is(rax)) {
+    movq(src1, kScratchRegister);
+  }
+  jmp(on_not_smi_result, near_jump);
+  bind(&safe_div);
+
+  // Sign extend eax into edx:eax.
+  cdq();
+  idivl(src2);
+  // Restore smi tags on inputs.
+  Integer32ToSmi(src2, src2);
+  if (src1.is(rax)) {
+    movq(src1, kScratchRegister);
+  }
+  // Check for a negative zero result.  If the result is zero, and the
+  // dividend is negative, go slow to return a floating point negative zero.
+  Label smi_result;
+  testl(rdx, rdx);
+  j(not_zero, &smi_result, Label::kNear);
+  testq(src1, src1);
+  j(negative, on_not_smi_result, near_jump);
+  bind(&smi_result);
+  Integer32ToSmi(dst, rdx);
+}
+
+
 void MacroAssembler::SmiNot(Register dst, Register src) {
   ASSERT(!dst.is(kScratchRegister));
   ASSERT(!src.is(kScratchRegister));
@@ -1166,6 +1812,7 @@ void MacroAssembler::SmiAndConstant(Register dst, Register src, Smi* constant) {
 
 void MacroAssembler::SmiOr(Register dst, Register src1, Register src2) {
   if (!dst.is(src1)) {
+    ASSERT(!src1.is(src2));
     movq(dst, src1);
   }
   or_(dst, src2);
@@ -1186,6 +1833,7 @@ void MacroAssembler::SmiOrConstant(Register dst, Register src, Smi* constant) {
 
 void MacroAssembler::SmiXor(Register dst, Register src1, Register src2) {
   if (!dst.is(src1)) {
+    ASSERT(!src1.is(src2));
     movq(dst, src1);
   }
   xor_(dst, src2);
@@ -1231,11 +1879,28 @@ void MacroAssembler::SmiShiftLeftConstant(Register dst,
 }
 
 
+void MacroAssembler::SmiShiftLogicalRightConstant(
+    Register dst, Register src, int shift_value,
+    Label* on_not_smi_result, Label::Distance near_jump) {
+  // Logic right shift interprets its result as an *unsigned* number.
+  if (dst.is(src)) {
+    UNIMPLEMENTED();  // Not used.
+  } else {
+    movq(dst, src);
+    if (shift_value == 0) {
+      testq(dst, dst);
+      j(negative, on_not_smi_result, near_jump);
+    }
+    shr(dst, Immediate(shift_value + kSmiShift));
+    shl(dst, Immediate(kSmiShift));
+  }
+}
+
+
 void MacroAssembler::SmiShiftLeft(Register dst,
                                   Register src1,
                                   Register src2) {
   ASSERT(!dst.is(rcx));
-  NearLabel result_ok;
   // Untag shift amount.
   if (!dst.is(src1)) {
     movq(dst, src1);
@@ -1247,6 +1912,45 @@ void MacroAssembler::SmiShiftLeft(Register dst,
 }
 
 
+void MacroAssembler::SmiShiftLogicalRight(Register dst,
+                                          Register src1,
+                                          Register src2,
+                                          Label* on_not_smi_result,
+                                          Label::Distance near_jump) {
+  ASSERT(!dst.is(kScratchRegister));
+  ASSERT(!src1.is(kScratchRegister));
+  ASSERT(!src2.is(kScratchRegister));
+  ASSERT(!dst.is(rcx));
+  // dst and src1 can be the same, because the one case that bails out
+  // is a shift by 0, which leaves dst, and therefore src1, unchanged.
+  if (src1.is(rcx) || src2.is(rcx)) {
+    movq(kScratchRegister, rcx);
+  }
+  if (!dst.is(src1)) {
+    movq(dst, src1);
+  }
+  SmiToInteger32(rcx, src2);
+  orl(rcx, Immediate(kSmiShift));
+  shr_cl(dst);  // Shift is rcx modulo 0x1f + 32.
+  shl(dst, Immediate(kSmiShift));
+  testq(dst, dst);
+  if (src1.is(rcx) || src2.is(rcx)) {
+    Label positive_result;
+    j(positive, &positive_result, Label::kNear);
+    if (src1.is(rcx)) {
+      movq(src1, kScratchRegister);
+    } else {
+      movq(src2, kScratchRegister);
+    }
+    jmp(on_not_smi_result, near_jump);
+    bind(&positive_result);
+  } else {
+    // src2 was zero and src1 negative.
+    j(negative, on_not_smi_result, near_jump);
+  }
+}
+
+
 void MacroAssembler::SmiShiftArithmeticRight(Register dst,
                                              Register src1,
                                              Register src2) {
@@ -1274,6 +1978,45 @@ void MacroAssembler::SmiShiftArithmeticRight(Register dst,
 }
 
 
+void MacroAssembler::SelectNonSmi(Register dst,
+                                  Register src1,
+                                  Register src2,
+                                  Label* on_not_smis,
+                                  Label::Distance near_jump) {
+  ASSERT(!dst.is(kScratchRegister));
+  ASSERT(!src1.is(kScratchRegister));
+  ASSERT(!src2.is(kScratchRegister));
+  ASSERT(!dst.is(src1));
+  ASSERT(!dst.is(src2));
+  // Both operands must not be smis.
+#ifdef DEBUG
+  if (allow_stub_calls()) {  // Check contains a stub call.
+    Condition not_both_smis = NegateCondition(CheckBothSmi(src1, src2));
+    Check(not_both_smis, "Both registers were smis in SelectNonSmi.");
+  }
+#endif
+  ASSERT_EQ(0, kSmiTag);
+  ASSERT_EQ(0, Smi::FromInt(0));
+  movl(kScratchRegister, Immediate(kSmiTagMask));
+  and_(kScratchRegister, src1);
+  testl(kScratchRegister, src2);
+  // If non-zero then both are smis.
+  j(not_zero, on_not_smis, near_jump);
+
+  // Exactly one operand is a smi.
+  ASSERT_EQ(1, static_cast<int>(kSmiTagMask));
+  // kScratchRegister still holds src1 & kSmiTag, which is either zero or one.
+  subq(kScratchRegister, Immediate(1));
+  // If src1 is a smi, then scratch register all 1s, else it is all 0s.
+  movq(dst, src1);
+  xor_(dst, src2);
+  and_(dst, kScratchRegister);
+  // If src1 is a smi, dst holds src1 ^ src2, else it is zero.
+  xor_(dst, src1);
+  // If src1 is a smi, dst is src2, else it is src1, i.e., the non-smi.
+}
+
+
 SmiIndex MacroAssembler::SmiToIndex(Register dst,
                                     Register src,
                                     int shift) {
@@ -1309,6 +2052,104 @@ SmiIndex MacroAssembler::SmiToNegativeIndex(Register dst,
 }
 
 
+void MacroAssembler::AddSmiField(Register dst, const Operand& src) {
+  ASSERT_EQ(0, kSmiShift % kBitsPerByte);
+  addl(dst, Operand(src, kSmiShift / kBitsPerByte));
+}
+
+
+void MacroAssembler::JumpIfNotString(Register object,
+                                     Register object_map,
+                                     Label* not_string,
+                                     Label::Distance near_jump) {
+  Condition is_smi = CheckSmi(object);
+  j(is_smi, not_string, near_jump);
+  CmpObjectType(object, FIRST_NONSTRING_TYPE, object_map);
+  j(above_equal, not_string, near_jump);
+}
+
+
+void MacroAssembler::JumpIfNotBothSequentialAsciiStrings(
+    Register first_object,
+    Register second_object,
+    Register scratch1,
+    Register scratch2,
+    Label* on_fail,
+    Label::Distance near_jump) {
+  // Check that both objects are not smis.
+  Condition either_smi = CheckEitherSmi(first_object, second_object);
+  j(either_smi, on_fail, near_jump);
+
+  // Load instance type for both strings.
+  movq(scratch1, FieldOperand(first_object, HeapObject::kMapOffset));
+  movq(scratch2, FieldOperand(second_object, HeapObject::kMapOffset));
+  movzxbl(scratch1, FieldOperand(scratch1, Map::kInstanceTypeOffset));
+  movzxbl(scratch2, FieldOperand(scratch2, Map::kInstanceTypeOffset));
+
+  // Check that both are flat ascii strings.
+  ASSERT(kNotStringTag != 0);
+  const int kFlatAsciiStringMask =
+      kIsNotStringMask | kStringRepresentationMask | kStringEncodingMask;
+  const int kFlatAsciiStringTag = ASCII_STRING_TYPE;
+
+  andl(scratch1, Immediate(kFlatAsciiStringMask));
+  andl(scratch2, Immediate(kFlatAsciiStringMask));
+  // Interleave the bits to check both scratch1 and scratch2 in one test.
+  ASSERT_EQ(0, kFlatAsciiStringMask & (kFlatAsciiStringMask << 3));
+  lea(scratch1, Operand(scratch1, scratch2, times_8, 0));
+  cmpl(scratch1,
+       Immediate(kFlatAsciiStringTag + (kFlatAsciiStringTag << 3)));
+  j(not_equal, on_fail, near_jump);
+}
+
+
+void MacroAssembler::JumpIfInstanceTypeIsNotSequentialAscii(
+    Register instance_type,
+    Register scratch,
+    Label* failure,
+    Label::Distance near_jump) {
+  if (!scratch.is(instance_type)) {
+    movl(scratch, instance_type);
+  }
+
+  const int kFlatAsciiStringMask =
+      kIsNotStringMask | kStringRepresentationMask | kStringEncodingMask;
+
+  andl(scratch, Immediate(kFlatAsciiStringMask));
+  cmpl(scratch, Immediate(kStringTag | kSeqStringTag | kAsciiStringTag));
+  j(not_equal, failure, near_jump);
+}
+
+
+void MacroAssembler::JumpIfBothInstanceTypesAreNotSequentialAscii(
+    Register first_object_instance_type,
+    Register second_object_instance_type,
+    Register scratch1,
+    Register scratch2,
+    Label* on_fail,
+    Label::Distance near_jump) {
+  // Load instance type for both strings.
+  movq(scratch1, first_object_instance_type);
+  movq(scratch2, second_object_instance_type);
+
+  // Check that both are flat ascii strings.
+  ASSERT(kNotStringTag != 0);
+  const int kFlatAsciiStringMask =
+      kIsNotStringMask | kStringRepresentationMask | kStringEncodingMask;
+  const int kFlatAsciiStringTag = ASCII_STRING_TYPE;
+
+  andl(scratch1, Immediate(kFlatAsciiStringMask));
+  andl(scratch2, Immediate(kFlatAsciiStringMask));
+  // Interleave the bits to check both scratch1 and scratch2 in one test.
+  ASSERT_EQ(0, kFlatAsciiStringMask & (kFlatAsciiStringMask << 3));
+  lea(scratch1, Operand(scratch1, scratch2, times_8, 0));
+  cmpl(scratch1,
+       Immediate(kFlatAsciiStringTag + (kFlatAsciiStringTag << 3)));
+  j(not_equal, on_fail, near_jump);
+}
+
+
+
 void MacroAssembler::Move(Register dst, Register src) {
   if (!dst.is(src)) {
     movq(dst, src);
@@ -1339,7 +2180,7 @@ void MacroAssembler::Move(const Operand& dst, Handle<Object> source) {
 
 void MacroAssembler::Cmp(Register dst, Handle<Object> source) {
   if (source->IsSmi()) {
-    SmiCompare(dst, Smi::cast(*source));
+    Cmp(dst, Smi::cast(*source));
   } else {
     Move(kScratchRegister, source);
     cmpq(dst, kScratchRegister);
@@ -1349,7 +2190,7 @@ void MacroAssembler::Cmp(Register dst, Handle<Object> source) {
 
 void MacroAssembler::Cmp(const Operand& dst, Handle<Object> source) {
   if (source->IsSmi()) {
-    SmiCompare(dst, Smi::cast(*source));
+    Cmp(dst, Smi::cast(*source));
   } else {
     ASSERT(source->IsHeapObject());
     movq(kScratchRegister, source, RelocInfo::EMBEDDED_OBJECT);
@@ -1393,7 +2234,7 @@ void MacroAssembler::Test(const Operand& src, Smi* source) {
 
 
 void MacroAssembler::Jump(ExternalReference ext) {
-  movq(kScratchRegister, ext);
+  LoadAddress(kScratchRegister, ext);
   jmp(kScratchRegister);
 }
 
@@ -1410,21 +2251,48 @@ void MacroAssembler::Jump(Handle<Code> code_object, RelocInfo::Mode rmode) {
 }
 
 
+int MacroAssembler::CallSize(ExternalReference ext) {
+  // Opcode for call kScratchRegister is: Rex.B FF D4 (three bytes).
+  const int kCallInstructionSize = 3;
+  return LoadAddressSize(ext) + kCallInstructionSize;
+}
+
+
 void MacroAssembler::Call(ExternalReference ext) {
-  movq(kScratchRegister, ext);
+#ifdef DEBUG
+  int end_position = pc_offset() + CallSize(ext);
+#endif
+  LoadAddress(kScratchRegister, ext);
   call(kScratchRegister);
+#ifdef DEBUG
+  CHECK_EQ(end_position, pc_offset());
+#endif
 }
 
 
 void MacroAssembler::Call(Address destination, RelocInfo::Mode rmode) {
+#ifdef DEBUG
+  int end_position = pc_offset() + CallSize(destination, rmode);
+#endif
   movq(kScratchRegister, destination, rmode);
   call(kScratchRegister);
+#ifdef DEBUG
+  CHECK_EQ(pc_offset(), end_position);
+#endif
 }
 
 
-void MacroAssembler::Call(Handle<Code> code_object, RelocInfo::Mode rmode) {
+void MacroAssembler::Call(Handle<Code> code_object,
+                          RelocInfo::Mode rmode,
+                          unsigned ast_id) {
+#ifdef DEBUG
+  int end_position = pc_offset() + CallSize(code_object);
+#endif
   ASSERT(RelocInfo::IsCodeTarget(rmode));
-  call(code_object, rmode);
+  call(code_object, rmode, ast_id);
+#ifdef DEBUG
+  CHECK_EQ(end_position, pc_offset());
+#endif
 }
 
 
@@ -1440,10 +2308,10 @@ void MacroAssembler::Pushad() {
   push(r9);
   // r10 is kScratchRegister.
   push(r11);
-  push(r12);
+  // r12 is kSmiConstantRegister.
   // r13 is kRootRegister.
   push(r14);
-  // r15 is kSmiConstantRegister
+  push(r15);
   STATIC_ASSERT(11 == kNumSafepointSavedRegisters);
   // Use lea for symmetry with Popad.
   int sp_delta =
@@ -1457,8 +2325,8 @@ void MacroAssembler::Popad() {
   int sp_delta =
       (kNumSafepointRegisters - kNumSafepointSavedRegisters) * kPointerSize;
   lea(rsp, Operand(rsp, sp_delta));
+  pop(r15);
   pop(r14);
-  pop(r12);
   pop(r11);
   pop(r9);
   pop(r8);
@@ -1477,7 +2345,7 @@ void MacroAssembler::Dropad() {
 
 
 // Order general registers are pushed by Pushad:
-// rax, rcx, rdx, rbx, rsi, rdi, r8, r9, r11, r12, r14.
+// rax, rcx, rdx, rbx, rsi, rdi, r8, r9, r11, r14, r15.
 int MacroAssembler::kSafepointPushRegisterIndices[Register::kNumRegisters] = {
     0,
     1,
@@ -1491,10 +2359,10 @@ int MacroAssembler::kSafepointPushRegisterIndices[Register::kNumRegisters] = {
     7,
     -1,
     8,
-    9,
     -1,
-    10,
-    -1
+    -1,
+    9,
+    10
 };
 
 
@@ -1544,18 +2412,20 @@ void MacroAssembler::PushTryHandler(CodeLocation try_location,
     push(Immediate(0));  // NULL frame pointer.
   }
   // Save the current handler.
-  movq(kScratchRegister, ExternalReference(Top::k_handler_address));
-  push(Operand(kScratchRegister, 0));
+  Operand handler_operand =
+      ExternalOperand(ExternalReference(Isolate::k_handler_address, isolate()));
+  push(handler_operand);
   // Link this handler.
-  movq(Operand(kScratchRegister, 0), rsp);
+  movq(handler_operand, rsp);
 }
 
 
 void MacroAssembler::PopTryHandler() {
   ASSERT_EQ(0, StackHandlerConstants::kNextOffset);
   // Unlink this handler.
-  movq(kScratchRegister, ExternalReference(Top::k_handler_address));
-  pop(Operand(kScratchRegister, 0));
+  Operand handler_operand =
+      ExternalOperand(ExternalReference(Isolate::k_handler_address, isolate()));
+  pop(handler_operand);
   // Remove the remaining fields.
   addq(rsp, Immediate(StackHandlerConstants::kSize - kPointerSize));
 }
@@ -1573,21 +2443,20 @@ void MacroAssembler::Throw(Register value) {
     movq(rax, value);
   }
 
-  ExternalReference handler_address(Top::k_handler_address);
-  movq(kScratchRegister, handler_address);
-  movq(rsp, Operand(kScratchRegister, 0));
+  ExternalReference handler_address(Isolate::k_handler_address, isolate());
+  Operand handler_operand = ExternalOperand(handler_address);
+  movq(rsp, handler_operand);
   // get next in chain
-  pop(rcx);
-  movq(Operand(kScratchRegister, 0), rcx);
+  pop(handler_operand);
   pop(rbp);  // pop frame pointer
   pop(rdx);  // remove state
 
   // Before returning we restore the context from the frame pointer if not NULL.
   // The frame pointer is NULL in the exception handler of a JS entry frame.
   Set(rsi, 0);  // Tentatively set context pointer to NULL
-  NearLabel skip;
+  Label skip;
   cmpq(rbp, Immediate(0));
-  j(equal, &skip);
+  j(equal, &skip, Label::kNear);
   movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
   bind(&skip);
   ret(0);
@@ -1601,17 +2470,16 @@ void MacroAssembler::ThrowUncatchable(UncatchableExceptionType type,
     movq(rax, value);
   }
   // Fetch top stack handler.
-  ExternalReference handler_address(Top::k_handler_address);
-  movq(kScratchRegister, handler_address);
-  movq(rsp, Operand(kScratchRegister, 0));
+  ExternalReference handler_address(Isolate::k_handler_address, isolate());
+  Load(rsp, handler_address);
 
   // Unwind the handlers until the ENTRY handler is found.
-  NearLabel loop, done;
+  Label loop, done;
   bind(&loop);
   // Load the type of the current stack handler.
   const int kStateOffset = StackHandlerConstants::kStateOffset;
   cmpq(Operand(rsp, kStateOffset), Immediate(StackHandler::ENTRY));
-  j(equal, &done);
+  j(equal, &done, Label::kNear);
   // Fetch the next handler in the list.
   const int kNextOffset = StackHandlerConstants::kNextOffset;
   movq(rsp, Operand(rsp, kNextOffset));
@@ -1619,19 +2487,21 @@ void MacroAssembler::ThrowUncatchable(UncatchableExceptionType type,
   bind(&done);
 
   // Set the top handler address to next handler past the current ENTRY handler.
-  movq(kScratchRegister, handler_address);
-  pop(Operand(kScratchRegister, 0));
+  Operand handler_operand = ExternalOperand(handler_address);
+  pop(handler_operand);
 
   if (type == OUT_OF_MEMORY) {
     // Set external caught exception to false.
-    ExternalReference external_caught(Top::k_external_caught_exception_address);
-    movq(rax, Immediate(false));
-    store_rax(external_caught);
+    ExternalReference external_caught(
+        Isolate::k_external_caught_exception_address, isolate());
+    Set(rax, static_cast<int64_t>(false));
+    Store(external_caught, rax);
 
     // Set pending exception and rax to out of memory exception.
-    ExternalReference pending_exception(Top::k_pending_exception_address);
+    ExternalReference pending_exception(Isolate::k_pending_exception_address,
+                                        isolate());
     movq(rax, Failure::OutOfMemoryException(), RelocInfo::NONE);
-    store_rax(pending_exception);
+    Store(pending_exception, rax);
   }
 
   // Clear the context pointer.
@@ -1639,14 +2509,14 @@ void MacroAssembler::ThrowUncatchable(UncatchableExceptionType type,
 
   // Restore registers from handler.
   STATIC_ASSERT(StackHandlerConstants::kNextOffset + kPointerSize ==
-            StackHandlerConstants::kFPOffset);
+                StackHandlerConstants::kFPOffset);
   pop(rbp);  // FP
   STATIC_ASSERT(StackHandlerConstants::kFPOffset + kPointerSize ==
-            StackHandlerConstants::kStateOffset);
+                StackHandlerConstants::kStateOffset);
   pop(rdx);  // State
 
   STATIC_ASSERT(StackHandlerConstants::kStateOffset + kPointerSize ==
-            StackHandlerConstants::kPCOffset);
+                StackHandlerConstants::kPCOffset);
   ret(0);
 }
 
@@ -1688,11 +2558,21 @@ void MacroAssembler::CmpInstanceType(Register map, InstanceType type) {
 }
 
 
+void MacroAssembler::CheckFastElements(Register map,
+                                       Label* fail,
+                                       Label::Distance distance) {
+  STATIC_ASSERT(JSObject::FAST_ELEMENTS == 0);
+  cmpb(FieldOperand(map, Map::kBitField2Offset),
+       Immediate(Map::kMaximumBitField2FastElementValue));
+  j(above, fail, distance);
+}
+
+
 void MacroAssembler::CheckMap(Register obj,
                               Handle<Map> map,
                               Label* fail,
-                              bool is_heap_object) {
-  if (!is_heap_object) {
+                              SmiCheckType smi_check_type) {
+  if (smi_check_type == DO_SMI_CHECK) {
     JumpIfSmi(obj, fail);
   }
   Cmp(FieldOperand(obj, HeapObject::kMapOffset), map);
@@ -1700,26 +2580,87 @@ void MacroAssembler::CheckMap(Register obj,
 }
 
 
+void MacroAssembler::ClampUint8(Register reg) {
+  Label done;
+  testl(reg, Immediate(0xFFFFFF00));
+  j(zero, &done, Label::kNear);
+  setcc(negative, reg);  // 1 if negative, 0 if positive.
+  decb(reg);  // 0 if negative, 255 if positive.
+  bind(&done);
+}
+
+
+void MacroAssembler::ClampDoubleToUint8(XMMRegister input_reg,
+                                        XMMRegister temp_xmm_reg,
+                                        Register result_reg,
+                                        Register temp_reg) {
+  Label done;
+  Set(result_reg, 0);
+  xorps(temp_xmm_reg, temp_xmm_reg);
+  ucomisd(input_reg, temp_xmm_reg);
+  j(below, &done, Label::kNear);
+  uint64_t one_half = BitCast<uint64_t, double>(0.5);
+  Set(temp_reg, one_half);
+  movq(temp_xmm_reg, temp_reg);
+  addsd(temp_xmm_reg, input_reg);
+  cvttsd2si(result_reg, temp_xmm_reg);
+  testl(result_reg, Immediate(0xFFFFFF00));
+  j(zero, &done, Label::kNear);
+  Set(result_reg, 255);
+  bind(&done);
+}
+
+
+void MacroAssembler::LoadInstanceDescriptors(Register map,
+                                             Register descriptors) {
+  movq(descriptors, FieldOperand(map,
+                                 Map::kInstanceDescriptorsOrBitField3Offset));
+  Label not_smi;
+  JumpIfNotSmi(descriptors, &not_smi, Label::kNear);
+  Move(descriptors, isolate()->factory()->empty_descriptor_array());
+  bind(&not_smi);
+}
+
+
+void MacroAssembler::DispatchMap(Register obj,
+                                 Handle<Map> map,
+                                 Handle<Code> success,
+                                 SmiCheckType smi_check_type) {
+  Label fail;
+  if (smi_check_type == DO_SMI_CHECK) {
+    JumpIfSmi(obj, &fail);
+  }
+  Cmp(FieldOperand(obj, HeapObject::kMapOffset), map);
+  j(equal, success, RelocInfo::CODE_TARGET);
+
+  bind(&fail);
+}
+
+
 void MacroAssembler::AbortIfNotNumber(Register object) {
-  NearLabel ok;
+  Label ok;
   Condition is_smi = CheckSmi(object);
-  j(is_smi, &ok);
+  j(is_smi, &ok, Label::kNear);
   Cmp(FieldOperand(object, HeapObject::kMapOffset),
-      Factory::heap_number_map());
+      isolate()->factory()->heap_number_map());
   Assert(equal, "Operand not a number");
   bind(&ok);
 }
 
 
 void MacroAssembler::AbortIfSmi(Register object) {
-  NearLabel ok;
   Condition is_smi = CheckSmi(object);
   Assert(NegateCondition(is_smi), "Operand is a smi");
 }
 
 
 void MacroAssembler::AbortIfNotSmi(Register object) {
-  NearLabel ok;
+  Condition is_smi = CheckSmi(object);
+  Assert(is_smi, "Operand is not a smi");
+}
+
+
+void MacroAssembler::AbortIfNotSmi(const Operand& object) {
   Condition is_smi = CheckSmi(object);
   Assert(is_smi, "Operand is not a smi");
 }
@@ -1770,10 +2711,10 @@ void MacroAssembler::TryGetFunctionPrototype(Register function,
   j(not_equal, miss);
 
   // Make sure that the function has an instance prototype.
-  NearLabel non_instance;
+  Label non_instance;
   testb(FieldOperand(result, Map::kBitFieldOffset),
         Immediate(1 << Map::kHasNonInstancePrototype));
-  j(not_zero, &non_instance);
+  j(not_zero, &non_instance, Label::kNear);
 
   // Get the prototype or initial map from the function.
   movq(result,
@@ -1786,13 +2727,13 @@ void MacroAssembler::TryGetFunctionPrototype(Register function,
   j(equal, miss);
 
   // If the function does not have an initial map, we're done.
-  NearLabel done;
+  Label done;
   CmpObjectType(result, MAP_TYPE, kScratchRegister);
-  j(not_equal, &done);
+  j(not_equal, &done, Label::kNear);
 
   // Get the prototype from the initial map.
   movq(result, FieldOperand(result, Map::kPrototypeOffset));
-  jmp(&done);
+  jmp(&done, Label::kNear);
 
   // Non-instance prototype: Fetch prototype from constructor field
   // in initial map.
@@ -1806,8 +2747,8 @@ void MacroAssembler::TryGetFunctionPrototype(Register function,
 
 void MacroAssembler::SetCounter(StatsCounter* counter, int value) {
   if (FLAG_native_code_counters && counter->Enabled()) {
-    movq(kScratchRegister, ExternalReference(counter));
-    movl(Operand(kScratchRegister, 0), Immediate(value));
+    Operand counter_operand = ExternalOperand(ExternalReference(counter));
+    movl(counter_operand, Immediate(value));
   }
 }
 
@@ -1815,12 +2756,11 @@ void MacroAssembler::SetCounter(StatsCounter* counter, int value) {
 void MacroAssembler::IncrementCounter(StatsCounter* counter, int value) {
   ASSERT(value > 0);
   if (FLAG_native_code_counters && counter->Enabled()) {
-    movq(kScratchRegister, ExternalReference(counter));
-    Operand operand(kScratchRegister, 0);
+    Operand counter_operand = ExternalOperand(ExternalReference(counter));
     if (value == 1) {
-      incl(operand);
+      incl(counter_operand);
     } else {
-      addl(operand, Immediate(value));
+      addl(counter_operand, Immediate(value));
     }
   }
 }
@@ -1829,12 +2769,11 @@ void MacroAssembler::IncrementCounter(StatsCounter* counter, int value) {
 void MacroAssembler::DecrementCounter(StatsCounter* counter, int value) {
   ASSERT(value > 0);
   if (FLAG_native_code_counters && counter->Enabled()) {
-    movq(kScratchRegister, ExternalReference(counter));
-    Operand operand(kScratchRegister, 0);
+    Operand counter_operand = ExternalOperand(ExternalReference(counter));
     if (value == 1) {
-      decl(operand);
+      decl(counter_operand);
     } else {
-      subl(operand, Immediate(value));
+      subl(counter_operand, Immediate(value));
     }
   }
 }
@@ -1844,31 +2783,51 @@ void MacroAssembler::DecrementCounter(StatsCounter* counter, int value) {
 void MacroAssembler::DebugBreak() {
   ASSERT(allow_stub_calls());
   Set(rax, 0);  // No arguments.
-  movq(rbx, ExternalReference(Runtime::kDebugBreak));
+  LoadAddress(rbx, ExternalReference(Runtime::kDebugBreak, isolate()));
   CEntryStub ces(1);
   Call(ces.GetCode(), RelocInfo::DEBUG_BREAK);
 }
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 
+void MacroAssembler::SetCallKind(Register dst, CallKind call_kind) {
+  // This macro takes the dst register to make the code more readable
+  // at the call sites. However, the dst register has to be rcx to
+  // follow the calling convention which requires the call type to be
+  // in rcx.
+  ASSERT(dst.is(rcx));
+  if (call_kind == CALL_AS_FUNCTION) {
+    LoadSmiConstant(dst, Smi::FromInt(1));
+  } else {
+    LoadSmiConstant(dst, Smi::FromInt(0));
+  }
+}
+
+
 void MacroAssembler::InvokeCode(Register code,
                                 const ParameterCount& expected,
                                 const ParameterCount& actual,
                                 InvokeFlag flag,
-                                PostCallGenerator* post_call_generator) {
-  NearLabel done;
+                                const CallWrapper& call_wrapper,
+                                CallKind call_kind) {
+  Label done;
   InvokePrologue(expected,
                  actual,
                  Handle<Code>::null(),
                  code,
                  &done,
                  flag,
-                 post_call_generator);
+                 Label::kNear,
+                 call_wrapper,
+                 call_kind);
   if (flag == CALL_FUNCTION) {
+    call_wrapper.BeforeCall(CallSize(code));
+    SetCallKind(rcx, call_kind);
     call(code);
-    if (post_call_generator != NULL) post_call_generator->Generate();
+    call_wrapper.AfterCall();
   } else {
     ASSERT(flag == JUMP_FUNCTION);
+    SetCallKind(rcx, call_kind);
     jmp(code);
   }
   bind(&done);
@@ -1880,8 +2839,9 @@ void MacroAssembler::InvokeCode(Handle<Code> code,
                                 const ParameterCount& actual,
                                 RelocInfo::Mode rmode,
                                 InvokeFlag flag,
-                                PostCallGenerator* post_call_generator) {
-  NearLabel done;
+                                const CallWrapper& call_wrapper,
+                                CallKind call_kind) {
+  Label done;
   Register dummy = rax;
   InvokePrologue(expected,
                  actual,
@@ -1889,12 +2849,17 @@ void MacroAssembler::InvokeCode(Handle<Code> code,
                  dummy,
                  &done,
                  flag,
-                 post_call_generator);
+                 Label::kNear,
+                 call_wrapper,
+                 call_kind);
   if (flag == CALL_FUNCTION) {
+    call_wrapper.BeforeCall(CallSize(code));
+    SetCallKind(rcx, call_kind);
     Call(code, rmode);
-    if (post_call_generator != NULL) post_call_generator->Generate();
+    call_wrapper.AfterCall();
   } else {
     ASSERT(flag == JUMP_FUNCTION);
+    SetCallKind(rcx, call_kind);
     Jump(code, rmode);
   }
   bind(&done);
@@ -1904,7 +2869,8 @@ void MacroAssembler::InvokeCode(Handle<Code> code,
 void MacroAssembler::InvokeFunction(Register function,
                                     const ParameterCount& actual,
                                     InvokeFlag flag,
-                                    PostCallGenerator* post_call_generator) {
+                                    const CallWrapper& call_wrapper,
+                                    CallKind call_kind) {
   ASSERT(function.is(rdi));
   movq(rdx, FieldOperand(function, JSFunction::kSharedFunctionInfoOffset));
   movq(rsi, FieldOperand(function, JSFunction::kContextOffset));
@@ -1915,14 +2881,15 @@ void MacroAssembler::InvokeFunction(Register function,
   movq(rdx, FieldOperand(rdi, JSFunction::kCodeEntryOffset));
 
   ParameterCount expected(rbx);
-  InvokeCode(rdx, expected, actual, flag, post_call_generator);
+  InvokeCode(rdx, expected, actual, flag, call_wrapper, call_kind);
 }
 
 
 void MacroAssembler::InvokeFunction(JSFunction* function,
                                     const ParameterCount& actual,
                                     InvokeFlag flag,
-                                    PostCallGenerator* post_call_generator) {
+                                    const CallWrapper& call_wrapper,
+                                    CallKind call_kind) {
   ASSERT(function->is_compiled());
   // Get the function and setup the context.
   Move(rdi, Handle<JSFunction>(function));
@@ -1933,7 +2900,7 @@ void MacroAssembler::InvokeFunction(JSFunction* function,
     // the Code object every time we call the function.
     movq(rdx, FieldOperand(rdi, JSFunction::kCodeEntryOffset));
     ParameterCount expected(function->shared()->formal_parameter_count());
-    InvokeCode(rdx, expected, actual, flag, post_call_generator);
+    InvokeCode(rdx, expected, actual, flag, call_wrapper, call_kind);
   } else {
     // Invoke the cached code.
     Handle<Code> code(function->code());
@@ -1943,7 +2910,79 @@ void MacroAssembler::InvokeFunction(JSFunction* function,
                actual,
                RelocInfo::CODE_TARGET,
                flag,
-               post_call_generator);
+               call_wrapper,
+               call_kind);
+  }
+}
+
+
+void MacroAssembler::InvokePrologue(const ParameterCount& expected,
+                                    const ParameterCount& actual,
+                                    Handle<Code> code_constant,
+                                    Register code_register,
+                                    Label* done,
+                                    InvokeFlag flag,
+                                    Label::Distance near_jump,
+                                    const CallWrapper& call_wrapper,
+                                    CallKind call_kind) {
+  bool definitely_matches = false;
+  Label invoke;
+  if (expected.is_immediate()) {
+    ASSERT(actual.is_immediate());
+    if (expected.immediate() == actual.immediate()) {
+      definitely_matches = true;
+    } else {
+      Set(rax, actual.immediate());
+      if (expected.immediate() ==
+              SharedFunctionInfo::kDontAdaptArgumentsSentinel) {
+        // Don't worry about adapting arguments for built-ins that
+        // don't want that done. Skip adaption code by making it look
+        // like we have a match between expected and actual number of
+        // arguments.
+        definitely_matches = true;
+      } else {
+        Set(rbx, expected.immediate());
+      }
+    }
+  } else {
+    if (actual.is_immediate()) {
+      // Expected is in register, actual is immediate. This is the
+      // case when we invoke function values without going through the
+      // IC mechanism.
+      cmpq(expected.reg(), Immediate(actual.immediate()));
+      j(equal, &invoke, Label::kNear);
+      ASSERT(expected.reg().is(rbx));
+      Set(rax, actual.immediate());
+    } else if (!expected.reg().is(actual.reg())) {
+      // Both expected and actual are in (different) registers. This
+      // is the case when we invoke functions using call and apply.
+      cmpq(expected.reg(), actual.reg());
+      j(equal, &invoke, Label::kNear);
+      ASSERT(actual.reg().is(rax));
+      ASSERT(expected.reg().is(rbx));
+    }
+  }
+
+  if (!definitely_matches) {
+    Handle<Code> adaptor = isolate()->builtins()->ArgumentsAdaptorTrampoline();
+    if (!code_constant.is_null()) {
+      movq(rdx, code_constant, RelocInfo::EMBEDDED_OBJECT);
+      addq(rdx, Immediate(Code::kHeaderSize - kHeapObjectTag));
+    } else if (!code_register.is(rdx)) {
+      movq(rdx, code_register);
+    }
+
+    if (flag == CALL_FUNCTION) {
+      call_wrapper.BeforeCall(CallSize(adaptor));
+      SetCallKind(rcx, call_kind);
+      Call(adaptor, RelocInfo::CODE_TARGET);
+      call_wrapper.AfterCall();
+      jmp(done, near_jump);
+    } else {
+      SetCallKind(rcx, call_kind);
+      Jump(adaptor, RelocInfo::CODE_TARGET);
+    }
+    bind(&invoke);
   }
 }
 
@@ -1955,9 +2994,9 @@ void MacroAssembler::EnterFrame(StackFrame::Type type) {
   Push(Smi::FromInt(type));
   movq(kScratchRegister, CodeObject(), RelocInfo::EMBEDDED_OBJECT);
   push(kScratchRegister);
-  if (FLAG_debug_code) {
+  if (emit_debug_code()) {
     movq(kScratchRegister,
-         Factory::undefined_value(),
+         isolate()->factory()->undefined_value(),
          RelocInfo::EMBEDDED_OBJECT);
     cmpq(Operand(rsp, 0), kScratchRegister);
     Check(not_equal, "code object not properly patched");
@@ -1966,7 +3005,7 @@ void MacroAssembler::EnterFrame(StackFrame::Type type) {
 
 
 void MacroAssembler::LeaveFrame(StackFrame::Type type) {
-  if (FLAG_debug_code) {
+  if (emit_debug_code()) {
     Move(kScratchRegister, Smi::FromInt(type));
     cmpq(Operand(rbp, StandardFrameConstants::kMarkerOffset), kScratchRegister);
     Check(equal, "stack frame types must match");
@@ -1992,16 +3031,12 @@ void MacroAssembler::EnterExitFramePrologue(bool save_rax) {
   push(kScratchRegister);  // Accessed from EditFrame::code_slot.
 
   // Save the frame pointer and the context in top.
-  ExternalReference c_entry_fp_address(Top::k_c_entry_fp_address);
-  ExternalReference context_address(Top::k_context_address);
   if (save_rax) {
-    movq(r14, rax);  // Backup rax before we use it.
+    movq(r14, rax);  // Backup rax in callee-save register.
   }
 
-  movq(rax, rbp);
-  store_rax(c_entry_fp_address);
-  movq(rax, rsi);
-  store_rax(context_address);
+  Store(ExternalReference(Isolate::k_c_entry_fp_address, isolate()), rbp);
+  Store(ExternalReference(Isolate::k_context_address, isolate()), rsi);
 }
 
 
@@ -2013,7 +3048,6 @@ void MacroAssembler::EnterExitFrameEpilogue(int arg_stack_space,
 #endif
   // Optionally save all XMM registers.
   if (save_doubles) {
-    CpuFeatures::Scope scope(SSE2);
     int space = XMMRegister::kNumRegisters * kDoubleSize +
         arg_stack_space * kPointerSize;
     subq(rsp, Immediate(space));
@@ -2027,11 +3061,11 @@ void MacroAssembler::EnterExitFrameEpilogue(int arg_stack_space,
   }
 
   // Get the required frame alignment for the OS.
-  static const int kFrameAlignment = OS::ActivationFrameAlignment();
+  const int kFrameAlignment = OS::ActivationFrameAlignment();
   if (kFrameAlignment > 0) {
     ASSERT(IsPowerOf2(kFrameAlignment));
-    movq(kScratchRegister, Immediate(-kFrameAlignment));
-    and_(rsp, kScratchRegister);
+    ASSERT(is_int8(kFrameAlignment));
+    and_(rsp, Immediate(-kFrameAlignment));
   }
 
   // Patch the saved entry sp.
@@ -2042,10 +3076,10 @@ void MacroAssembler::EnterExitFrameEpilogue(int arg_stack_space,
 void MacroAssembler::EnterExitFrame(int arg_stack_space, bool save_doubles) {
   EnterExitFramePrologue(true);
 
-  // Setup argv in callee-saved register r12. It is reused in LeaveExitFrame,
+  // Setup argv in callee-saved register r15. It is reused in LeaveExitFrame,
   // so it must be retained across the C-call.
   int offset = StandardFrameConstants::kCallerSPOffset - kPointerSize;
-  lea(r12, Operand(rbp, r14, times_pointer_size, offset));
+  lea(r15, Operand(rbp, r14, times_pointer_size, offset));
 
   EnterExitFrameEpilogue(arg_stack_space, save_doubles);
 }
@@ -2059,7 +3093,7 @@ void MacroAssembler::EnterApiExitFrame(int arg_stack_space) {
 
 void MacroAssembler::LeaveExitFrame(bool save_doubles) {
   // Registers:
-  // r12 : argv
+  // r15 : argv
   if (save_doubles) {
     int offset = -2 * kPointerSize;
     for (int i = 0; i < XMMRegister::kNumAllocatableRegisters; i++) {
@@ -2073,7 +3107,7 @@ void MacroAssembler::LeaveExitFrame(bool save_doubles) {
 
   // Drop everything up to and including the arguments and the receiver
   // from the caller stack.
-  lea(rsp, Operand(r12, 1 * kPointerSize));
+  lea(rsp, Operand(r15, 1 * kPointerSize));
 
   // Push the return address to get ready to return.
   push(rcx);
@@ -2092,17 +3126,18 @@ void MacroAssembler::LeaveApiExitFrame() {
 
 void MacroAssembler::LeaveExitFrameEpilogue() {
   // Restore current context from top and clear it in debug mode.
-  ExternalReference context_address(Top::k_context_address);
-  movq(kScratchRegister, context_address);
-  movq(rsi, Operand(kScratchRegister, 0));
+  ExternalReference context_address(Isolate::k_context_address, isolate());
+  Operand context_operand = ExternalOperand(context_address);
+  movq(rsi, context_operand);
 #ifdef DEBUG
-  movq(Operand(kScratchRegister, 0), Immediate(0));
+  movq(context_operand, Immediate(0));
 #endif
 
   // Clear the top frame.
-  ExternalReference c_entry_fp_address(Top::k_c_entry_fp_address);
-  movq(kScratchRegister, c_entry_fp_address);
-  movq(Operand(kScratchRegister, 0), Immediate(0));
+  ExternalReference c_entry_fp_address(Isolate::k_c_entry_fp_address,
+                                       isolate());
+  Operand c_entry_fp_operand = ExternalOperand(c_entry_fp_address);
+  movq(c_entry_fp_operand, Immediate(0));
 }
 
 
@@ -2117,7 +3152,7 @@ void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg,
   movq(scratch, Operand(rbp, StandardFrameConstants::kContextOffset));
 
   // When generating debug code, make sure the lexical context is set.
-  if (FLAG_debug_code) {
+  if (emit_debug_code()) {
     cmpq(scratch, Immediate(0));
     Check(not_equal, "we should not have an empty lexical context");
   }
@@ -2127,9 +3162,9 @@ void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg,
   movq(scratch, FieldOperand(scratch, GlobalObject::kGlobalContextOffset));
 
   // Check the context is a global context.
-  if (FLAG_debug_code) {
+  if (emit_debug_code()) {
     Cmp(FieldOperand(scratch, HeapObject::kMapOffset),
-        Factory::global_context_map());
+        isolate()->factory()->global_context_map());
     Check(equal, "JSGlobalObject::global_context should be a global context.");
   }
 
@@ -2143,7 +3178,7 @@ void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg,
   // object.
 
   // Check the context is a global context.
-  if (FLAG_debug_code) {
+  if (emit_debug_code()) {
     // Preserve original value of holder_reg.
     push(holder_reg);
     movq(holder_reg, FieldOperand(holder_reg, JSGlobalProxy::kContextOffset));
@@ -2173,7 +3208,7 @@ void MacroAssembler::LoadAllocationTopHelper(Register result,
                                              Register scratch,
                                              AllocationFlags flags) {
   ExternalReference new_space_allocation_top =
-      ExternalReference::new_space_allocation_top_address();
+      ExternalReference::new_space_allocation_top_address(isolate());
 
   // Just return if allocation top is already known.
   if ((flags & RESULT_CONTAINS_TOP) != 0) {
@@ -2181,8 +3216,8 @@ void MacroAssembler::LoadAllocationTopHelper(Register result,
     ASSERT(!scratch.is_valid());
 #ifdef DEBUG
     // Assert that result actually contains top on entry.
-    movq(kScratchRegister, new_space_allocation_top);
-    cmpq(result, Operand(kScratchRegister, 0));
+    Operand top_operand = ExternalOperand(new_space_allocation_top);
+    cmpq(result, top_operand);
     Check(equal, "Unexpected allocation top");
 #endif
     return;
@@ -2191,39 +3226,30 @@ void MacroAssembler::LoadAllocationTopHelper(Register result,
   // Move address of new object to result. Use scratch register if available,
   // and keep address in scratch until call to UpdateAllocationTopHelper.
   if (scratch.is_valid()) {
-    movq(scratch, new_space_allocation_top);
+    LoadAddress(scratch, new_space_allocation_top);
     movq(result, Operand(scratch, 0));
-  } else if (result.is(rax)) {
-    load_rax(new_space_allocation_top);
   } else {
-    movq(kScratchRegister, new_space_allocation_top);
-    movq(result, Operand(kScratchRegister, 0));
+    Load(result, new_space_allocation_top);
   }
 }
 
 
 void MacroAssembler::UpdateAllocationTopHelper(Register result_end,
                                                Register scratch) {
-  if (FLAG_debug_code) {
+  if (emit_debug_code()) {
     testq(result_end, Immediate(kObjectAlignmentMask));
     Check(zero, "Unaligned allocation in new space");
   }
 
   ExternalReference new_space_allocation_top =
-      ExternalReference::new_space_allocation_top_address();
+      ExternalReference::new_space_allocation_top_address(isolate());
 
   // Update new top.
-  if (result_end.is(rax)) {
-    // rax can be stored directly to a memory location.
-    store_rax(new_space_allocation_top);
+  if (scratch.is_valid()) {
+    // Scratch already contains address of allocation top.
+    movq(Operand(scratch, 0), result_end);
   } else {
-    // Register required - use scratch provided if available.
-    if (scratch.is_valid()) {
-      movq(Operand(scratch, 0), result_end);
-    } else {
-      movq(kScratchRegister, new_space_allocation_top);
-      movq(Operand(kScratchRegister, 0), result_end);
-    }
+    Store(new_space_allocation_top, result_end);
   }
 }
 
@@ -2235,7 +3261,7 @@ void MacroAssembler::AllocateInNewSpace(int object_size,
                                         Label* gc_required,
                                         AllocationFlags flags) {
   if (!FLAG_inline_new) {
-    if (FLAG_debug_code) {
+    if (emit_debug_code()) {
       // Trash the registers to simulate an allocation failure.
       movl(result, Immediate(0x7091));
       if (result_end.is_valid()) {
@@ -2255,7 +3281,7 @@ void MacroAssembler::AllocateInNewSpace(int object_size,
 
   // Calculate new top and bail out if new space is exhausted.
   ExternalReference new_space_allocation_limit =
-      ExternalReference::new_space_allocation_limit_address();
+      ExternalReference::new_space_allocation_limit_address(isolate());
 
   Register top_reg = result_end.is_valid() ? result_end : result;
 
@@ -2264,8 +3290,8 @@ void MacroAssembler::AllocateInNewSpace(int object_size,
   }
   addq(top_reg, Immediate(object_size));
   j(carry, gc_required);
-  movq(kScratchRegister, new_space_allocation_limit);
-  cmpq(top_reg, Operand(kScratchRegister, 0));
+  Operand limit_operand = ExternalOperand(new_space_allocation_limit);
+  cmpq(top_reg, limit_operand);
   j(above, gc_required);
 
   // Update allocation top.
@@ -2293,7 +3319,7 @@ void MacroAssembler::AllocateInNewSpace(int header_size,
                                         Label* gc_required,
                                         AllocationFlags flags) {
   if (!FLAG_inline_new) {
-    if (FLAG_debug_code) {
+    if (emit_debug_code()) {
       // Trash the registers to simulate an allocation failure.
       movl(result, Immediate(0x7091));
       movl(result_end, Immediate(0x7191));
@@ -2312,15 +3338,15 @@ void MacroAssembler::AllocateInNewSpace(int header_size,
 
   // Calculate new top and bail out if new space is exhausted.
   ExternalReference new_space_allocation_limit =
-      ExternalReference::new_space_allocation_limit_address();
+      ExternalReference::new_space_allocation_limit_address(isolate());
 
   // We assume that element_count*element_size + header_size does not
   // overflow.
   lea(result_end, Operand(element_count, element_size, header_size));
   addq(result_end, result);
   j(carry, gc_required);
-  movq(kScratchRegister, new_space_allocation_limit);
-  cmpq(result_end, Operand(kScratchRegister, 0));
+  Operand limit_operand = ExternalOperand(new_space_allocation_limit);
+  cmpq(result_end, limit_operand);
   j(above, gc_required);
 
   // Update allocation top.
@@ -2340,7 +3366,7 @@ void MacroAssembler::AllocateInNewSpace(Register object_size,
                                         Label* gc_required,
                                         AllocationFlags flags) {
   if (!FLAG_inline_new) {
-    if (FLAG_debug_code) {
+    if (emit_debug_code()) {
       // Trash the registers to simulate an allocation failure.
       movl(result, Immediate(0x7091));
       movl(result_end, Immediate(0x7191));
@@ -2359,14 +3385,14 @@ void MacroAssembler::AllocateInNewSpace(Register object_size,
 
   // Calculate new top and bail out if new space is exhausted.
   ExternalReference new_space_allocation_limit =
-      ExternalReference::new_space_allocation_limit_address();
+      ExternalReference::new_space_allocation_limit_address(isolate());
   if (!object_size.is(result_end)) {
     movq(result_end, object_size);
   }
   addq(result_end, result);
   j(carry, gc_required);
-  movq(kScratchRegister, new_space_allocation_limit);
-  cmpq(result_end, Operand(kScratchRegister, 0));
+  Operand limit_operand = ExternalOperand(new_space_allocation_limit);
+  cmpq(result_end, limit_operand);
   j(above, gc_required);
 
   // Update allocation top.
@@ -2381,16 +3407,16 @@ void MacroAssembler::AllocateInNewSpace(Register object_size,
 
 void MacroAssembler::UndoAllocationInNewSpace(Register object) {
   ExternalReference new_space_allocation_top =
-      ExternalReference::new_space_allocation_top_address();
+      ExternalReference::new_space_allocation_top_address(isolate());
 
   // Make sure the object has no tag before resetting top.
   and_(object, Immediate(~kHeapObjectTagMask));
-  movq(kScratchRegister, new_space_allocation_top);
+  Operand top_operand = ExternalOperand(new_space_allocation_top);
 #ifdef DEBUG
-  cmpq(object, Operand(kScratchRegister, 0));
+  cmpq(object, top_operand);
   Check(below, "Undo allocation of non allocated memory");
 #endif
-  movq(Operand(kScratchRegister, 0), object);
+  movq(top_operand, object);
 }
 
 
@@ -2524,18 +3550,77 @@ void MacroAssembler::AllocateAsciiConsString(Register result,
 }
 
 
+// Copy memory, byte-by-byte, from source to destination.  Not optimized for
+// long or aligned copies.  The contents of scratch and length are destroyed.
+// Destination is incremented by length, source, length and scratch are
+// clobbered.
+// A simpler loop is faster on small copies, but slower on large ones.
+// The cld() instruction must have been emitted, to set the direction flag(),
+// before calling this function.
+void MacroAssembler::CopyBytes(Register destination,
+                               Register source,
+                               Register length,
+                               int min_length,
+                               Register scratch) {
+  ASSERT(min_length >= 0);
+  if (FLAG_debug_code) {
+    cmpl(length, Immediate(min_length));
+    Assert(greater_equal, "Invalid min_length");
+  }
+  Label loop, done, short_string, short_loop;
+
+  const int kLongStringLimit = 20;
+  if (min_length <= kLongStringLimit) {
+    cmpl(length, Immediate(kLongStringLimit));
+    j(less_equal, &short_string);
+  }
+
+  ASSERT(source.is(rsi));
+  ASSERT(destination.is(rdi));
+  ASSERT(length.is(rcx));
+
+  // Because source is 8-byte aligned in our uses of this function,
+  // we keep source aligned for the rep movs operation by copying the odd bytes
+  // at the end of the ranges.
+  movq(scratch, length);
+  shrl(length, Immediate(3));
+  repmovsq();
+  // Move remaining bytes of length.
+  andl(scratch, Immediate(0x7));
+  movq(length, Operand(source, scratch, times_1, -8));
+  movq(Operand(destination, scratch, times_1, -8), length);
+  addq(destination, scratch);
+
+  if (min_length <= kLongStringLimit) {
+    jmp(&done);
+
+    bind(&short_string);
+    if (min_length == 0) {
+      testl(length, length);
+      j(zero, &done);
+    }
+    lea(scratch, Operand(destination, length, times_1, 0));
+
+    bind(&short_loop);
+    movb(length, Operand(source, 0));
+    movb(Operand(destination, 0), length);
+    incq(source);
+    incq(destination);
+    cmpq(destination, scratch);
+    j(not_equal, &short_loop);
+
+    bind(&done);
+  }
+}
+
+
 void MacroAssembler::LoadContext(Register dst, int context_chain_length) {
   if (context_chain_length > 0) {
     // Move up the chain of contexts to the context containing the slot.
-    movq(dst, Operand(rsi, Context::SlotOffset(Context::CLOSURE_INDEX)));
-    // Load the function context (which is the incoming, outer context).
-    movq(dst, FieldOperand(dst, JSFunction::kContextOffset));
+    movq(dst, Operand(rsi, Context::SlotOffset(Context::PREVIOUS_INDEX)));
     for (int i = 1; i < context_chain_length; i++) {
-      movq(dst, Operand(dst, Context::SlotOffset(Context::CLOSURE_INDEX)));
-      movq(dst, FieldOperand(dst, JSFunction::kContextOffset));
+      movq(dst, Operand(dst, Context::SlotOffset(Context::PREVIOUS_INDEX)));
     }
-    // The context may be an intermediate context, not a function context.
-    movq(dst, Operand(dst, Context::SlotOffset(Context::FCONTEXT_INDEX)));
   } else {
     // Slot is in the current function context.  Move it into the
     // destination register in case we store into it (the write barrier
@@ -2543,17 +3628,25 @@ void MacroAssembler::LoadContext(Register dst, int context_chain_length) {
     movq(dst, rsi);
   }
 
-  // We should not have found a 'with' context by walking the context chain
-  // (i.e., the static scope chain and runtime context chain do not agree).
-  // A variable occurring in such a scope should have slot type LOOKUP and
-  // not CONTEXT.
-  if (FLAG_debug_code) {
-    cmpq(dst, Operand(dst, Context::SlotOffset(Context::FCONTEXT_INDEX)));
-    Check(equal, "Yo dawg, I heard you liked function contexts "
-                 "so I put function contexts in all your contexts");
+  // We should not have found a with or catch context by walking the context
+  // chain (i.e., the static scope chain and runtime context chain do not
+  // agree).  A variable occurring in such a scope should have slot type
+  // LOOKUP and not CONTEXT.
+  if (emit_debug_code()) {
+    CompareRoot(FieldOperand(dst, HeapObject::kMapOffset),
+                Heap::kWithContextMapRootIndex);
+    Check(not_equal, "Variable resolved to with context.");
+    CompareRoot(FieldOperand(dst, HeapObject::kMapOffset),
+                Heap::kCatchContextMapRootIndex);
+    Check(not_equal, "Variable resolved to catch context.");
   }
 }
 
+#ifdef _WIN64
+static const int kRegisterPassedArguments = 4;
+#else
+static const int kRegisterPassedArguments = 6;
+#endif
 
 void MacroAssembler::LoadGlobalFunction(int index, Register function) {
   // Load the global or builtins object from the current context.
@@ -2569,9 +3662,9 @@ void MacroAssembler::LoadGlobalFunctionInitialMap(Register function,
                                                   Register map) {
   // Load the initial map.  The global functions all have initial maps.
   movq(map, FieldOperand(function, JSFunction::kPrototypeOrInitialMapOffset));
-  if (FLAG_debug_code) {
+  if (emit_debug_code()) {
     Label ok, fail;
-    CheckMap(map, Factory::meta_map(), &fail, false);
+    CheckMap(map, isolate()->factory()->meta_map(), &fail, DO_SMI_CHECK);
     jmp(&ok);
     bind(&fail);
     Abort("Global functions must have initial map");
@@ -2589,11 +3682,10 @@ int MacroAssembler::ArgumentStackSlotsForCFunctionCall(int num_arguments) {
   // and the caller does not reserve stack slots for them.
   ASSERT(num_arguments >= 0);
 #ifdef _WIN64
-  static const int kMinimumStackSlots = 4;
+  const int kMinimumStackSlots = kRegisterPassedArguments;
   if (num_arguments < kMinimumStackSlots) return kMinimumStackSlots;
   return num_arguments;
 #else
-  static const int kRegisterPassedArguments = 6;
   if (num_arguments < kRegisterPassedArguments) return 0;
   return num_arguments - kRegisterPassedArguments;
 #endif
@@ -2604,6 +3696,7 @@ void MacroAssembler::PrepareCallCFunction(int num_arguments) {
   int frame_alignment = OS::ActivationFrameAlignment();
   ASSERT(frame_alignment != 0);
   ASSERT(num_arguments >= 0);
+
   // Make stack end at alignment and allocate space for arguments and old rsp.
   movq(kScratchRegister, rsp);
   ASSERT(IsPowerOf2(frame_alignment));
@@ -2617,14 +3710,14 @@ void MacroAssembler::PrepareCallCFunction(int num_arguments) {
 
 void MacroAssembler::CallCFunction(ExternalReference function,
                                    int num_arguments) {
-  movq(rax, function);
+  LoadAddress(rax, function);
   CallCFunction(rax, num_arguments);
 }
 
 
 void MacroAssembler::CallCFunction(Register function, int num_arguments) {
   // Check stack alignment.
-  if (FLAG_debug_code) {
+  if (emit_debug_code()) {
     CheckStackAlignment();
   }
 
@@ -2638,7 +3731,9 @@ void MacroAssembler::CallCFunction(Register function, int num_arguments) {
 
 
 CodePatcher::CodePatcher(byte* address, int size)
-    : address_(address), size_(size), masm_(address, size + Assembler::kGap) {
+    : address_(address),
+      size_(size),
+      masm_(Isolate::Current(), address, size + Assembler::kGap) {
   // Create a new macro assembler pointing to the address of the code to patch.
   // The size is adjusted with kGap on order for the assembler to generate size
   // bytes of instructions without failing with buffer size constraints.