Upgrade V8 to 3.7.0

22 files changed, 2727 insertions, 1213 deletions

diff --git a/deps/v8/src/arm/assembler-arm-inl.h b/deps/v8/src/arm/assembler-arm-inl.h
index 3e19a4538..93cecf52b 100644
--- a/deps/v8/src/arm/assembler-arm-inl.h
+++ b/deps/v8/src/arm/assembler-arm-inl.h
@@ -77,6 +77,11 @@ int RelocInfo::target_address_size() {
 void RelocInfo::set_target_address(Address target) {
   ASSERT(IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY);
   Assembler::set_target_address_at(pc_, target);
+  if (host() != NULL && IsCodeTarget(rmode_)) {
+    Object* target_code = Code::GetCodeFromTargetAddress(target);
+    host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(
+        host(), this, HeapObject::cast(target_code));
+  }
 }
 
 
@@ -101,6 +106,10 @@ Object** RelocInfo::target_object_address() {
 void RelocInfo::set_target_object(Object* target) {
   ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
   Assembler::set_target_address_at(pc_, reinterpret_cast<Address>(target));
+  if (host() != NULL && target->IsHeapObject()) {
+    host()->GetHeap()->incremental_marking()->RecordWrite(
+        host(), &Memory::Object_at(pc_), HeapObject::cast(target));
+  }
 }
 
 
@@ -131,6 +140,12 @@ void RelocInfo::set_target_cell(JSGlobalPropertyCell* cell) {
   ASSERT(rmode_ == RelocInfo::GLOBAL_PROPERTY_CELL);
   Address address = cell->address() + JSGlobalPropertyCell::kValueOffset;
   Memory::Address_at(pc_) = address;
+  if (host() != NULL) {
+    // TODO(1550) We are passing NULL as a slot because cell can never be on
+    // evacuation candidate.
+    host()->GetHeap()->incremental_marking()->RecordWrite(
+        host(), NULL, cell);
+  }
 }
 
 
@@ -147,6 +162,11 @@ void RelocInfo::set_call_address(Address target) {
   ASSERT((IsJSReturn(rmode()) && IsPatchedReturnSequence()) ||
          (IsDebugBreakSlot(rmode()) && IsPatchedDebugBreakSlotSequence()));
   Memory::Address_at(pc_ + 2 * Assembler::kInstrSize) = target;
+  if (host() != NULL) {
+    Object* target_code = Code::GetCodeFromTargetAddress(target);
+    host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(
+        host(), this, HeapObject::cast(target_code));
+  }
 }
 
 
@@ -195,7 +215,7 @@ bool RelocInfo::IsPatchedDebugBreakSlotSequence() {
 void RelocInfo::Visit(ObjectVisitor* visitor) {
   RelocInfo::Mode mode = rmode();
   if (mode == RelocInfo::EMBEDDED_OBJECT) {
-    visitor->VisitPointer(target_object_address());
+    visitor->VisitEmbeddedPointer(this);
   } else if (RelocInfo::IsCodeTarget(mode)) {
     visitor->VisitCodeTarget(this);
   } else if (mode == RelocInfo::GLOBAL_PROPERTY_CELL) {
@@ -221,7 +241,7 @@ template<typename StaticVisitor>
 void RelocInfo::Visit(Heap* heap) {
   RelocInfo::Mode mode = rmode();
   if (mode == RelocInfo::EMBEDDED_OBJECT) {
-    StaticVisitor::VisitPointer(heap, target_object_address());
+    StaticVisitor::VisitEmbeddedPointer(heap, this);
   } else if (RelocInfo::IsCodeTarget(mode)) {
     StaticVisitor::VisitCodeTarget(heap, this);
   } else if (mode == RelocInfo::GLOBAL_PROPERTY_CELL) {
diff --git a/deps/v8/src/arm/assembler-arm.cc b/deps/v8/src/arm/assembler-arm.cc
index 0ec36921a..329493a34 100644
--- a/deps/v8/src/arm/assembler-arm.cc
+++ b/deps/v8/src/arm/assembler-arm.cc
@@ -78,7 +78,9 @@ static uint64_t CpuFeaturesImpliedByCompiler() {
 
 
 void CpuFeatures::Probe() {
-  ASSERT(!initialized_);
+  unsigned standard_features = (OS::CpuFeaturesImpliedByPlatform() |
+                                CpuFeaturesImpliedByCompiler());
+  ASSERT(supported_ == 0 || supported_ == standard_features);
 #ifdef DEBUG
   initialized_ = true;
 #endif
@@ -86,8 +88,7 @@ void CpuFeatures::Probe() {
   // Get the features implied by the OS and the compiler settings. This is the
   // minimal set of features which is also alowed for generated code in the
   // snapshot.
-  supported_ |= OS::CpuFeaturesImpliedByPlatform();
-  supported_ |= CpuFeaturesImpliedByCompiler();
+  supported_ |= standard_features;
 
   if (Serializer::enabled()) {
     // No probing for features if we might serialize (generate snapshot).
@@ -2505,7 +2506,8 @@ void Assembler::dd(uint32_t data) {
 
 
 void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
-  RelocInfo rinfo(pc_, rmode, data);  // we do not try to reuse pool constants
+  // We do not try to reuse pool constants.
+  RelocInfo rinfo(pc_, rmode, data, NULL);
   if (rmode >= RelocInfo::JS_RETURN && rmode <= RelocInfo::DEBUG_BREAK_SLOT) {
     // Adjust code for new modes.
     ASSERT(RelocInfo::IsDebugBreakSlot(rmode)
@@ -2537,7 +2539,7 @@ void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
     }
     ASSERT(buffer_space() >= kMaxRelocSize);  // too late to grow buffer here
     if (rmode == RelocInfo::CODE_TARGET_WITH_ID) {
-      RelocInfo reloc_info_with_ast_id(pc_, rmode, RecordedAstId());
+      RelocInfo reloc_info_with_ast_id(pc_, rmode, RecordedAstId(), NULL);
       ClearRecordedAstId();
       reloc_info_writer.Write(&reloc_info_with_ast_id);
     } else {
diff --git a/deps/v8/src/arm/assembler-arm.h b/deps/v8/src/arm/assembler-arm.h
index 9a586936f..d19b64da5 100644
--- a/deps/v8/src/arm/assembler-arm.h
+++ b/deps/v8/src/arm/assembler-arm.h
@@ -1209,6 +1209,10 @@ class Assembler : public AssemblerBase {
   PositionsRecorder* positions_recorder() { return &positions_recorder_; }
 
   // Read/patch instructions
+  Instr instr_at(int pos) { return *reinterpret_cast<Instr*>(buffer_ + pos); }
+  void instr_at_put(int pos, Instr instr) {
+    *reinterpret_cast<Instr*>(buffer_ + pos) = instr;
+  }
   static Instr instr_at(byte* pc) { return *reinterpret_cast<Instr*>(pc); }
   static void instr_at_put(byte* pc, Instr instr) {
     *reinterpret_cast<Instr*>(pc) = instr;
@@ -1263,12 +1267,6 @@ class Assembler : public AssemblerBase {
 
   int buffer_space() const { return reloc_info_writer.pos() - pc_; }
 
-  // Read/patch instructions
-  Instr instr_at(int pos) { return *reinterpret_cast<Instr*>(buffer_ + pos); }
-  void instr_at_put(int pos, Instr instr) {
-    *reinterpret_cast<Instr*>(buffer_ + pos) = instr;
-  }
-
   // Decode branch instruction at pos and return branch target pos
   int target_at(int pos);
 
diff --git a/deps/v8/src/arm/builtins-arm.cc b/deps/v8/src/arm/builtins-arm.cc
index 60d2081c2..32b7896a5 100644
--- a/deps/v8/src/arm/builtins-arm.cc
+++ b/deps/v8/src/arm/builtins-arm.cc
@@ -582,10 +582,11 @@ void Builtins::Generate_StringConstructCode(MacroAssembler* masm) {
   __ bind(&convert_argument);
   __ push(function);  // Preserve the function.
   __ IncrementCounter(counters->string_ctor_conversions(), 1, r3, r4);
-  __ EnterInternalFrame();
-  __ push(r0);
-  __ InvokeBuiltin(Builtins::TO_STRING, CALL_FUNCTION);
-  __ LeaveInternalFrame();
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
+    __ push(r0);
+    __ InvokeBuiltin(Builtins::TO_STRING, CALL_FUNCTION);
+  }
   __ pop(function);
   __ mov(argument, r0);
   __ b(&argument_is_string);
@@ -601,10 +602,11 @@ void Builtins::Generate_StringConstructCode(MacroAssembler* masm) {
   // create a string wrapper.
   __ bind(&gc_required);
   __ IncrementCounter(counters->string_ctor_gc_required(), 1, r3, r4);
-  __ EnterInternalFrame();
-  __ push(argument);
-  __ CallRuntime(Runtime::kNewStringWrapper, 1);
-  __ LeaveInternalFrame();
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
+    __ push(argument);
+    __ CallRuntime(Runtime::kNewStringWrapper, 1);
+  }
   __ Ret();
 }
 
@@ -617,12 +619,12 @@ void Builtins::Generate_JSConstructCall(MacroAssembler* masm) {
   //  -- sp[...]: constructor arguments
   // -----------------------------------
 
-  Label non_function_call;
+  Label slow, non_function_call;
   // Check that the function is not a smi.
   __ JumpIfSmi(r1, &non_function_call);
   // Check that the function is a JSFunction.
   __ CompareObjectType(r1, r2, r2, JS_FUNCTION_TYPE);
-  __ b(ne, &non_function_call);
+  __ b(ne, &slow);
 
   // Jump to the function-specific construct stub.
   __ ldr(r2, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
@@ -631,10 +633,19 @@ void Builtins::Generate_JSConstructCall(MacroAssembler* masm) {
 
   // r0: number of arguments
   // r1: called object
+  // r2: object type
+  Label do_call;
+  __ bind(&slow);
+  __ cmp(r2, Operand(JS_FUNCTION_PROXY_TYPE));
+  __ b(ne, &non_function_call);
+  __ GetBuiltinEntry(r3, Builtins::CALL_FUNCTION_PROXY_AS_CONSTRUCTOR);
+  __ jmp(&do_call);
+
   __ bind(&non_function_call);
+  __ GetBuiltinEntry(r3, Builtins::CALL_NON_FUNCTION_AS_CONSTRUCTOR);
+  __ bind(&do_call);
   // Set expected number of arguments to zero (not changing r0).
   __ mov(r2, Operand(0, RelocInfo::NONE));
-  __ GetBuiltinEntry(r3, Builtins::CALL_NON_FUNCTION_AS_CONSTRUCTOR);
   __ SetCallKind(r5, CALL_AS_METHOD);
   __ Jump(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
           RelocInfo::CODE_TARGET);
@@ -650,321 +661,329 @@ static void Generate_JSConstructStubHelper(MacroAssembler* masm,
   Isolate* isolate = masm->isolate();
 
   // Enter a construct frame.
-  __ EnterConstructFrame();
-
-  // Preserve the two incoming parameters on the stack.
-  __ mov(r0, Operand(r0, LSL, kSmiTagSize));
-  __ push(r0);  // Smi-tagged arguments count.
-  __ push(r1);  // Constructor function.
-
-  // Try to allocate the object without transitioning into C code. If any of the
-  // preconditions is not met, the code bails out to the runtime call.
-  Label rt_call, allocated;
-  if (FLAG_inline_new) {
-    Label undo_allocation;
+  {
+    FrameScope scope(masm, StackFrame::CONSTRUCT);
+
+    // Preserve the two incoming parameters on the stack.
+    __ mov(r0, Operand(r0, LSL, kSmiTagSize));
+    __ push(r0);  // Smi-tagged arguments count.
+    __ push(r1);  // Constructor function.
+
+    // Try to allocate the object without transitioning into C code. If any of
+    // the preconditions is not met, the code bails out to the runtime call.
+    Label rt_call, allocated;
+    if (FLAG_inline_new) {
+      Label undo_allocation;
 #ifdef ENABLE_DEBUGGER_SUPPORT
-    ExternalReference debug_step_in_fp =
-        ExternalReference::debug_step_in_fp_address(isolate);
-    __ mov(r2, Operand(debug_step_in_fp));
-    __ ldr(r2, MemOperand(r2));
-    __ tst(r2, r2);
-    __ b(ne, &rt_call);
+      ExternalReference debug_step_in_fp =
+          ExternalReference::debug_step_in_fp_address(isolate);
+      __ mov(r2, Operand(debug_step_in_fp));
+      __ ldr(r2, MemOperand(r2));
+      __ tst(r2, r2);
+      __ b(ne, &rt_call);
 #endif
 
-    // Load the initial map and verify that it is in fact a map.
-    // r1: constructor function
-    __ ldr(r2, FieldMemOperand(r1, JSFunction::kPrototypeOrInitialMapOffset));
-    __ JumpIfSmi(r2, &rt_call);
-    __ CompareObjectType(r2, r3, r4, MAP_TYPE);
-    __ b(ne, &rt_call);
+      // Load the initial map and verify that it is in fact a map.
+      // r1: constructor function
+      __ ldr(r2, FieldMemOperand(r1, JSFunction::kPrototypeOrInitialMapOffset));
+      __ JumpIfSmi(r2, &rt_call);
+      __ CompareObjectType(r2, r3, r4, MAP_TYPE);
+      __ b(ne, &rt_call);
+
+      // Check that the constructor is not constructing a JSFunction (see
+      // comments in Runtime_NewObject in runtime.cc). In which case the
+      // initial map's instance type would be JS_FUNCTION_TYPE.
+      // r1: constructor function
+      // r2: initial map
+      __ CompareInstanceType(r2, r3, JS_FUNCTION_TYPE);
+      __ b(eq, &rt_call);
 
-    // Check that the constructor is not constructing a JSFunction (see comments
-    // in Runtime_NewObject in runtime.cc). In which case the initial map's
-    // instance type would be JS_FUNCTION_TYPE.
-    // r1: constructor function
-    // r2: initial map
-    __ CompareInstanceType(r2, r3, JS_FUNCTION_TYPE);
-    __ b(eq, &rt_call);
-
-    if (count_constructions) {
-      Label allocate;
-      // Decrease generous allocation count.
-      __ ldr(r3, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
-      MemOperand constructor_count =
-          FieldMemOperand(r3, SharedFunctionInfo::kConstructionCountOffset);
-      __ ldrb(r4, constructor_count);
-      __ sub(r4, r4, Operand(1), SetCC);
-      __ strb(r4, constructor_count);
-      __ b(ne, &allocate);
-
-      __ Push(r1, r2);
-
-      __ push(r1);  // constructor
-      // The call will replace the stub, so the countdown is only done once.
-      __ CallRuntime(Runtime::kFinalizeInstanceSize, 1);
-
-      __ pop(r2);
-      __ pop(r1);
-
-      __ bind(&allocate);
-    }
-
-    // Now allocate the JSObject on the heap.
-    // r1: constructor function
-    // r2: initial map
-    __ ldrb(r3, FieldMemOperand(r2, Map::kInstanceSizeOffset));
-    __ AllocateInNewSpace(r3, r4, r5, r6, &rt_call, SIZE_IN_WORDS);
+      if (count_constructions) {
+        Label allocate;
+        // Decrease generous allocation count.
+        __ ldr(r3, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
+        MemOperand constructor_count =
+            FieldMemOperand(r3, SharedFunctionInfo::kConstructionCountOffset);
+        __ ldrb(r4, constructor_count);
+        __ sub(r4, r4, Operand(1), SetCC);
+        __ strb(r4, constructor_count);
+        __ b(ne, &allocate);
+
+        __ Push(r1, r2);
+
+        __ push(r1);  // constructor
+        // The call will replace the stub, so the countdown is only done once.
+        __ CallRuntime(Runtime::kFinalizeInstanceSize, 1);
+
+        __ pop(r2);
+        __ pop(r1);
+
+        __ bind(&allocate);
+      }
 
-    // Allocated the JSObject, now initialize the fields. Map is set to initial
-    // map and properties and elements are set to empty fixed array.
-    // r1: constructor function
-    // r2: initial map
-    // r3: object size
-    // r4: JSObject (not tagged)
-    __ LoadRoot(r6, Heap::kEmptyFixedArrayRootIndex);
-    __ mov(r5, r4);
-    ASSERT_EQ(0 * kPointerSize, JSObject::kMapOffset);
-    __ str(r2, MemOperand(r5, kPointerSize, PostIndex));
-    ASSERT_EQ(1 * kPointerSize, JSObject::kPropertiesOffset);
-    __ str(r6, MemOperand(r5, kPointerSize, PostIndex));
-    ASSERT_EQ(2 * kPointerSize, JSObject::kElementsOffset);
-    __ str(r6, MemOperand(r5, kPointerSize, PostIndex));
-
-    // Fill all the in-object properties with the appropriate filler.
-    // r1: constructor function
-    // r2: initial map
-    // r3: object size (in words)
-    // r4: JSObject (not tagged)
-    // r5: First in-object property of JSObject (not tagged)
-    __ add(r6, r4, Operand(r3, LSL, kPointerSizeLog2));  // End of object.
-    ASSERT_EQ(3 * kPointerSize, JSObject::kHeaderSize);
-    { Label loop, entry;
+      // Now allocate the JSObject on the heap.
+      // r1: constructor function
+      // r2: initial map
+      __ ldrb(r3, FieldMemOperand(r2, Map::kInstanceSizeOffset));
+      __ AllocateInNewSpace(r3, r4, r5, r6, &rt_call, SIZE_IN_WORDS);
+
+      // Allocated the JSObject, now initialize the fields. Map is set to
+      // initial map and properties and elements are set to empty fixed array.
+      // r1: constructor function
+      // r2: initial map
+      // r3: object size
+      // r4: JSObject (not tagged)
+      __ LoadRoot(r6, Heap::kEmptyFixedArrayRootIndex);
+      __ mov(r5, r4);
+      ASSERT_EQ(0 * kPointerSize, JSObject::kMapOffset);
+      __ str(r2, MemOperand(r5, kPointerSize, PostIndex));
+      ASSERT_EQ(1 * kPointerSize, JSObject::kPropertiesOffset);
+      __ str(r6, MemOperand(r5, kPointerSize, PostIndex));
+      ASSERT_EQ(2 * kPointerSize, JSObject::kElementsOffset);
+      __ str(r6, MemOperand(r5, kPointerSize, PostIndex));
+
+      // Fill all the in-object properties with the appropriate filler.
+      // r1: constructor function
+      // r2: initial map
+      // r3: object size (in words)
+      // r4: JSObject (not tagged)
+      // r5: First in-object property of JSObject (not tagged)
+      __ add(r6, r4, Operand(r3, LSL, kPointerSizeLog2));  // End of object.
+      ASSERT_EQ(3 * kPointerSize, JSObject::kHeaderSize);
+      __ LoadRoot(r7, Heap::kUndefinedValueRootIndex);
       if (count_constructions) {
+        __ ldr(r0, FieldMemOperand(r2, Map::kInstanceSizesOffset));
+        __ Ubfx(r0, r0, Map::kPreAllocatedPropertyFieldsByte * kBitsPerByte,
+                kBitsPerByte);
+        __ add(r0, r5, Operand(r0, LSL, kPointerSizeLog2));
+        // r0: offset of first field after pre-allocated fields
+        if (FLAG_debug_code) {
+          __ cmp(r0, r6);
+          __ Assert(le, "Unexpected number of pre-allocated property fields.");
+        }
+        __ InitializeFieldsWithFiller(r5, r0, r7);
         // To allow for truncation.
         __ LoadRoot(r7, Heap::kOnePointerFillerMapRootIndex);
-      } else {
-        __ LoadRoot(r7, Heap::kUndefinedValueRootIndex);
       }
-      __ b(&entry);
-      __ bind(&loop);
-      __ str(r7, MemOperand(r5, kPointerSize, PostIndex));
-      __ bind(&entry);
-      __ cmp(r5, r6);
-      __ b(lt, &loop);
-    }
+      __ InitializeFieldsWithFiller(r5, r6, r7);
+
+      // Add the object tag to make the JSObject real, so that we can continue
+      // and jump into the continuation code at any time from now on. Any
+      // failures need to undo the allocation, so that the heap is in a
+      // consistent state and verifiable.
+      __ add(r4, r4, Operand(kHeapObjectTag));
+
+      // Check if a non-empty properties array is needed. Continue with
+      // allocated object if not fall through to runtime call if it is.
+      // r1: constructor function
+      // r4: JSObject
+      // r5: start of next object (not tagged)
+      __ ldrb(r3, FieldMemOperand(r2, Map::kUnusedPropertyFieldsOffset));
+      // The field instance sizes contains both pre-allocated property fields
+      // and in-object properties.
+      __ ldr(r0, FieldMemOperand(r2, Map::kInstanceSizesOffset));
+      __ Ubfx(r6, r0, Map::kPreAllocatedPropertyFieldsByte * kBitsPerByte,
+              kBitsPerByte);
+      __ add(r3, r3, Operand(r6));
+      __ Ubfx(r6, r0, Map::kInObjectPropertiesByte * kBitsPerByte,
+              kBitsPerByte);
+      __ sub(r3, r3, Operand(r6), SetCC);
+
+      // Done if no extra properties are to be allocated.
+      __ b(eq, &allocated);
+      __ Assert(pl, "Property allocation count failed.");
+
+      // Scale the number of elements by pointer size and add the header for
+      // FixedArrays to the start of the next object calculation from above.
+      // r1: constructor
+      // r3: number of elements in properties array
+      // r4: JSObject
+      // r5: start of next object
+      __ add(r0, r3, Operand(FixedArray::kHeaderSize / kPointerSize));
+      __ AllocateInNewSpace(
+          r0,
+          r5,
+          r6,
+          r2,
+          &undo_allocation,
+          static_cast<AllocationFlags>(RESULT_CONTAINS_TOP | SIZE_IN_WORDS));
+
+      // Initialize the FixedArray.
+      // r1: constructor
+      // r3: number of elements in properties array
+      // r4: JSObject
+      // r5: FixedArray (not tagged)
+      __ LoadRoot(r6, Heap::kFixedArrayMapRootIndex);
+      __ mov(r2, r5);
+      ASSERT_EQ(0 * kPointerSize, JSObject::kMapOffset);
+      __ str(r6, MemOperand(r2, kPointerSize, PostIndex));
+      ASSERT_EQ(1 * kPointerSize, FixedArray::kLengthOffset);
+      __ mov(r0, Operand(r3, LSL, kSmiTagSize));
+      __ str(r0, MemOperand(r2, kPointerSize, PostIndex));
+
+      // Initialize the fields to undefined.
+      // r1: constructor function
+      // r2: First element of FixedArray (not tagged)
+      // r3: number of elements in properties array
+      // r4: JSObject
+      // r5: FixedArray (not tagged)
+      __ add(r6, r2, Operand(r3, LSL, kPointerSizeLog2));  // End of object.
+      ASSERT_EQ(2 * kPointerSize, FixedArray::kHeaderSize);
+      { Label loop, entry;
+        if (count_constructions) {
+          __ LoadRoot(r7, Heap::kUndefinedValueRootIndex);
+        } else if (FLAG_debug_code) {
+          __ LoadRoot(r8, Heap::kUndefinedValueRootIndex);
+          __ cmp(r7, r8);
+          __ Assert(eq, "Undefined value not loaded.");
+        }
+        __ b(&entry);
+        __ bind(&loop);
+        __ str(r7, MemOperand(r2, kPointerSize, PostIndex));
+        __ bind(&entry);
+        __ cmp(r2, r6);
+        __ b(lt, &loop);
+      }
 
-    // Add the object tag to make the JSObject real, so that we can continue and
-    // jump into the continuation code at any time from now on. Any failures
-    // need to undo the allocation, so that the heap is in a consistent state
-    // and verifiable.
-    __ add(r4, r4, Operand(kHeapObjectTag));
+      // Store the initialized FixedArray into the properties field of
+      // the JSObject
+      // r1: constructor function
+      // r4: JSObject
+      // r5: FixedArray (not tagged)
+      __ add(r5, r5, Operand(kHeapObjectTag));  // Add the heap tag.
+      __ str(r5, FieldMemOperand(r4, JSObject::kPropertiesOffset));
+
+      // Continue with JSObject being successfully allocated
+      // r1: constructor function
+      // r4: JSObject
+      __ jmp(&allocated);
+
+      // Undo the setting of the new top so that the heap is verifiable. For
+      // example, the map's unused properties potentially do not match the
+      // allocated objects unused properties.
+      // r4: JSObject (previous new top)
+      __ bind(&undo_allocation);
+      __ UndoAllocationInNewSpace(r4, r5);
+    }
 
-    // Check if a non-empty properties array is needed. Continue with allocated
-    // object if not fall through to runtime call if it is.
+    // Allocate the new receiver object using the runtime call.
     // r1: constructor function
+    __ bind(&rt_call);
+    __ push(r1);  // argument for Runtime_NewObject
+    __ CallRuntime(Runtime::kNewObject, 1);
+    __ mov(r4, r0);
+
+    // Receiver for constructor call allocated.
     // r4: JSObject
-    // r5: start of next object (not tagged)
-    __ ldrb(r3, FieldMemOperand(r2, Map::kUnusedPropertyFieldsOffset));
-    // The field instance sizes contains both pre-allocated property fields and
-    // in-object properties.
-    __ ldr(r0, FieldMemOperand(r2, Map::kInstanceSizesOffset));
-    __ Ubfx(r6, r0, Map::kPreAllocatedPropertyFieldsByte * 8, 8);
-    __ add(r3, r3, Operand(r6));
-    __ Ubfx(r6, r0, Map::kInObjectPropertiesByte * 8, 8);
-    __ sub(r3, r3, Operand(r6), SetCC);
-
-    // Done if no extra properties are to be allocated.
-    __ b(eq, &allocated);
-    __ Assert(pl, "Property allocation count failed.");
-
-    // Scale the number of elements by pointer size and add the header for
-    // FixedArrays to the start of the next object calculation from above.
-    // r1: constructor
-    // r3: number of elements in properties array
-    // r4: JSObject
-    // r5: start of next object
-    __ add(r0, r3, Operand(FixedArray::kHeaderSize / kPointerSize));
-    __ AllocateInNewSpace(
-        r0,
-        r5,
-        r6,
-        r2,
-        &undo_allocation,
-        static_cast<AllocationFlags>(RESULT_CONTAINS_TOP | SIZE_IN_WORDS));
-
-    // Initialize the FixedArray.
-    // r1: constructor
-    // r3: number of elements in properties array
-    // r4: JSObject
-    // r5: FixedArray (not tagged)
-    __ LoadRoot(r6, Heap::kFixedArrayMapRootIndex);
-    __ mov(r2, r5);
-    ASSERT_EQ(0 * kPointerSize, JSObject::kMapOffset);
-    __ str(r6, MemOperand(r2, kPointerSize, PostIndex));
-    ASSERT_EQ(1 * kPointerSize, FixedArray::kLengthOffset);
-    __ mov(r0, Operand(r3, LSL, kSmiTagSize));
-    __ str(r0, MemOperand(r2, kPointerSize, PostIndex));
-
-    // Initialize the fields to undefined.
+    __ bind(&allocated);
+    __ push(r4);
+
+    // Push the function and the allocated receiver from the stack.
+    // sp[0]: receiver (newly allocated object)
+    // sp[1]: constructor function
+    // sp[2]: number of arguments (smi-tagged)
+    __ ldr(r1, MemOperand(sp, kPointerSize));
+    __ push(r1);  // Constructor function.
+    __ push(r4);  // Receiver.
+
+    // Reload the number of arguments from the stack.
     // r1: constructor function
-    // r2: First element of FixedArray (not tagged)
-    // r3: number of elements in properties array
-    // r4: JSObject
-    // r5: FixedArray (not tagged)
-    __ add(r6, r2, Operand(r3, LSL, kPointerSizeLog2));  // End of object.
-    ASSERT_EQ(2 * kPointerSize, FixedArray::kHeaderSize);
-    { Label loop, entry;
-      if (count_constructions) {
-        __ LoadRoot(r7, Heap::kUndefinedValueRootIndex);
-      } else if (FLAG_debug_code) {
-        __ LoadRoot(r8, Heap::kUndefinedValueRootIndex);
-        __ cmp(r7, r8);
-        __ Assert(eq, "Undefined value not loaded.");
-      }
-      __ b(&entry);
-      __ bind(&loop);
-      __ str(r7, MemOperand(r2, kPointerSize, PostIndex));
-      __ bind(&entry);
-      __ cmp(r2, r6);
-      __ b(lt, &loop);
-    }
-
-    // Store the initialized FixedArray into the properties field of
-    // the JSObject
+    // sp[0]: receiver
+    // sp[1]: constructor function
+    // sp[2]: receiver
+    // sp[3]: constructor function
+    // sp[4]: number of arguments (smi-tagged)
+    __ ldr(r3, MemOperand(sp, 4 * kPointerSize));
+
+    // Setup pointer to last argument.
+    __ add(r2, fp, Operand(StandardFrameConstants::kCallerSPOffset));
+
+    // Setup number of arguments for function call below
+    __ mov(r0, Operand(r3, LSR, kSmiTagSize));
+
+    // Copy arguments and receiver to the expression stack.
+    // r0: number of arguments
+    // r2: address of last argument (caller sp)
     // r1: constructor function
-    // r4: JSObject
-    // r5: FixedArray (not tagged)
-    __ add(r5, r5, Operand(kHeapObjectTag));  // Add the heap tag.
-    __ str(r5, FieldMemOperand(r4, JSObject::kPropertiesOffset));
+    // r3: number of arguments (smi-tagged)
+    // sp[0]: receiver
+    // sp[1]: constructor function
+    // sp[2]: receiver
+    // sp[3]: constructor function
+    // sp[4]: number of arguments (smi-tagged)
+    Label loop, entry;
+    __ b(&entry);
+    __ bind(&loop);
+    __ ldr(ip, MemOperand(r2, r3, LSL, kPointerSizeLog2 - 1));
+    __ push(ip);
+    __ bind(&entry);
+    __ sub(r3, r3, Operand(2), SetCC);
+    __ b(ge, &loop);
 
-    // Continue with JSObject being successfully allocated
+    // Call the function.
+    // r0: number of arguments
     // r1: constructor function
-    // r4: JSObject
-    __ jmp(&allocated);
-
-    // Undo the setting of the new top so that the heap is verifiable. For
-    // example, the map's unused properties potentially do not match the
-    // allocated objects unused properties.
-    // r4: JSObject (previous new top)
-    __ bind(&undo_allocation);
-    __ UndoAllocationInNewSpace(r4, r5);
-  }
-
-  // Allocate the new receiver object using the runtime call.
-  // r1: constructor function
-  __ bind(&rt_call);
-  __ push(r1);  // argument for Runtime_NewObject
-  __ CallRuntime(Runtime::kNewObject, 1);
-  __ mov(r4, r0);
-
-  // Receiver for constructor call allocated.
-  // r4: JSObject
-  __ bind(&allocated);
-  __ push(r4);
-
-  // Push the function and the allocated receiver from the stack.
-  // sp[0]: receiver (newly allocated object)
-  // sp[1]: constructor function
-  // sp[2]: number of arguments (smi-tagged)
-  __ ldr(r1, MemOperand(sp, kPointerSize));
-  __ push(r1);  // Constructor function.
-  __ push(r4);  // Receiver.
-
-  // Reload the number of arguments from the stack.
-  // r1: constructor function
-  // sp[0]: receiver
-  // sp[1]: constructor function
-  // sp[2]: receiver
-  // sp[3]: constructor function
-  // sp[4]: number of arguments (smi-tagged)
-  __ ldr(r3, MemOperand(sp, 4 * kPointerSize));
-
-  // Setup pointer to last argument.
-  __ add(r2, fp, Operand(StandardFrameConstants::kCallerSPOffset));
-
-  // Setup number of arguments for function call below
-  __ mov(r0, Operand(r3, LSR, kSmiTagSize));
+    if (is_api_function) {
+      __ ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
+      Handle<Code> code =
+          masm->isolate()->builtins()->HandleApiCallConstruct();
+      ParameterCount expected(0);
+      __ InvokeCode(code, expected, expected,
+                    RelocInfo::CODE_TARGET, CALL_FUNCTION, CALL_AS_METHOD);
+    } else {
+      ParameterCount actual(r0);
+      __ InvokeFunction(r1, actual, CALL_FUNCTION,
+                        NullCallWrapper(), CALL_AS_METHOD);
+    }
 
-  // Copy arguments and receiver to the expression stack.
-  // r0: number of arguments
-  // r2: address of last argument (caller sp)
-  // r1: constructor function
-  // r3: number of arguments (smi-tagged)
-  // sp[0]: receiver
-  // sp[1]: constructor function
-  // sp[2]: receiver
-  // sp[3]: constructor function
-  // sp[4]: number of arguments (smi-tagged)
-  Label loop, entry;
-  __ b(&entry);
-  __ bind(&loop);
-  __ ldr(ip, MemOperand(r2, r3, LSL, kPointerSizeLog2 - 1));
-  __ push(ip);
-  __ bind(&entry);
-  __ sub(r3, r3, Operand(2), SetCC);
-  __ b(ge, &loop);
+    // Pop the function from the stack.
+    // sp[0]: constructor function
+    // sp[2]: receiver
+    // sp[3]: constructor function
+    // sp[4]: number of arguments (smi-tagged)
+    __ pop();
 
-  // Call the function.
-  // r0: number of arguments
-  // r1: constructor function
-  if (is_api_function) {
-    __ ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
-    Handle<Code> code =
-        masm->isolate()->builtins()->HandleApiCallConstruct();
-    ParameterCount expected(0);
-    __ InvokeCode(code, expected, expected,
-                  RelocInfo::CODE_TARGET, CALL_FUNCTION, CALL_AS_METHOD);
-  } else {
-    ParameterCount actual(r0);
-    __ InvokeFunction(r1, actual, CALL_FUNCTION,
-                      NullCallWrapper(), CALL_AS_METHOD);
+    // Restore context from the frame.
+    // r0: result
+    // sp[0]: receiver
+    // sp[1]: constructor function
+    // sp[2]: number of arguments (smi-tagged)
+    __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
+
+    // If the result is an object (in the ECMA sense), we should get rid
+    // of the receiver and use the result; see ECMA-262 section 13.2.2-7
+    // on page 74.
+    Label use_receiver, exit;
+
+    // If the result is a smi, it is *not* an object in the ECMA sense.
+    // r0: result
+    // sp[0]: receiver (newly allocated object)
+    // sp[1]: constructor function
+    // sp[2]: number of arguments (smi-tagged)
+    __ JumpIfSmi(r0, &use_receiver);
+
+    // If the type of the result (stored in its map) is less than
+    // FIRST_SPEC_OBJECT_TYPE, it is not an object in the ECMA sense.
+    __ CompareObjectType(r0, r3, r3, FIRST_SPEC_OBJECT_TYPE);
+    __ b(ge, &exit);
+
+    // Throw away the result of the constructor invocation and use the
+    // on-stack receiver as the result.
+    __ bind(&use_receiver);
+    __ ldr(r0, MemOperand(sp));
+
+    // Remove receiver from the stack, remove caller arguments, and
+    // return.
+    __ bind(&exit);
+    // r0: result
+    // sp[0]: receiver (newly allocated object)
+    // sp[1]: constructor function
+    // sp[2]: number of arguments (smi-tagged)
+    __ ldr(r1, MemOperand(sp, 2 * kPointerSize));
+
+    // Leave construct frame.
   }
 
-  // Pop the function from the stack.
-  // sp[0]: constructor function
-  // sp[2]: receiver
-  // sp[3]: constructor function
-  // sp[4]: number of arguments (smi-tagged)
-  __ pop();
-
-  // Restore context from the frame.
-  // r0: result
-  // sp[0]: receiver
-  // sp[1]: constructor function
-  // sp[2]: number of arguments (smi-tagged)
-  __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
-
-  // If the result is an object (in the ECMA sense), we should get rid
-  // of the receiver and use the result; see ECMA-262 section 13.2.2-7
-  // on page 74.
-  Label use_receiver, exit;
-
-  // If the result is a smi, it is *not* an object in the ECMA sense.
-  // r0: result
-  // sp[0]: receiver (newly allocated object)
-  // sp[1]: constructor function
-  // sp[2]: number of arguments (smi-tagged)
-  __ JumpIfSmi(r0, &use_receiver);
-
-  // If the type of the result (stored in its map) is less than
-  // FIRST_SPEC_OBJECT_TYPE, it is not an object in the ECMA sense.
-  __ CompareObjectType(r0, r3, r3, FIRST_SPEC_OBJECT_TYPE);
-  __ b(ge, &exit);
-
-  // Throw away the result of the constructor invocation and use the
-  // on-stack receiver as the result.
-  __ bind(&use_receiver);
-  __ ldr(r0, MemOperand(sp));
-
-  // Remove receiver from the stack, remove caller arguments, and
-  // return.
-  __ bind(&exit);
-  // r0: result
-  // sp[0]: receiver (newly allocated object)
-  // sp[1]: constructor function
-  // sp[2]: number of arguments (smi-tagged)
-  __ ldr(r1, MemOperand(sp, 2 * kPointerSize));
-  __ LeaveConstructFrame();
   __ add(sp, sp, Operand(r1, LSL, kPointerSizeLog2 - 1));
   __ add(sp, sp, Operand(kPointerSize));
   __ IncrementCounter(isolate->counters()->constructed_objects(), 1, r1, r2);
@@ -997,63 +1016,64 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
   // r4: argv
   // r5-r7, cp may be clobbered
 
-  // Clear the context before we push it when entering the JS frame.
+  // Clear the context before we push it when entering the internal frame.
   __ mov(cp, Operand(0, RelocInfo::NONE));
 
   // Enter an internal frame.
-  __ EnterInternalFrame();
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
 
-  // Set up the context from the function argument.
-  __ ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
+    // Set up the context from the function argument.
+    __ ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
 
-  // Set up the roots register.
-  ExternalReference roots_address =
-      ExternalReference::roots_address(masm->isolate());
-  __ mov(r10, Operand(roots_address));
+    // Set up the roots register.
+    ExternalReference roots_address =
+        ExternalReference::roots_address(masm->isolate());
+    __ mov(r10, Operand(roots_address));
 
-  // Push the function and the receiver onto the stack.
-  __ push(r1);
-  __ push(r2);
+    // Push the function and the receiver onto the stack.
+    __ push(r1);
+    __ push(r2);
 
-  // Copy arguments to the stack in a loop.
-  // r1: function
-  // r3: argc
-  // r4: argv, i.e. points to first arg
-  Label loop, entry;
-  __ add(r2, r4, Operand(r3, LSL, kPointerSizeLog2));
-  // r2 points past last arg.
-  __ b(&entry);
-  __ bind(&loop);
-  __ ldr(r0, MemOperand(r4, kPointerSize, PostIndex));  // read next parameter
-  __ ldr(r0, MemOperand(r0));  // dereference handle
-  __ push(r0);  // push parameter
-  __ bind(&entry);
-  __ cmp(r4, r2);
-  __ b(ne, &loop);
-
-  // Initialize all JavaScript callee-saved registers, since they will be seen
-  // by the garbage collector as part of handlers.
-  __ LoadRoot(r4, Heap::kUndefinedValueRootIndex);
-  __ mov(r5, Operand(r4));
-  __ mov(r6, Operand(r4));
-  __ mov(r7, Operand(r4));
-  if (kR9Available == 1) {
-    __ mov(r9, Operand(r4));
-  }
+    // Copy arguments to the stack in a loop.
+    // r1: function
+    // r3: argc
+    // r4: argv, i.e. points to first arg
+    Label loop, entry;
+    __ add(r2, r4, Operand(r3, LSL, kPointerSizeLog2));
+    // r2 points past last arg.
+    __ b(&entry);
+    __ bind(&loop);
+    __ ldr(r0, MemOperand(r4, kPointerSize, PostIndex));  // read next parameter
+    __ ldr(r0, MemOperand(r0));  // dereference handle
+    __ push(r0);  // push parameter
+    __ bind(&entry);
+    __ cmp(r4, r2);
+    __ b(ne, &loop);
 
-  // Invoke the code and pass argc as r0.
-  __ mov(r0, Operand(r3));
-  if (is_construct) {
-    __ Call(masm->isolate()->builtins()->JSConstructCall());
-  } else {
-    ParameterCount actual(r0);
-    __ InvokeFunction(r1, actual, CALL_FUNCTION,
-                      NullCallWrapper(), CALL_AS_METHOD);
-  }
+    // Initialize all JavaScript callee-saved registers, since they will be seen
+    // by the garbage collector as part of handlers.
+    __ LoadRoot(r4, Heap::kUndefinedValueRootIndex);
+    __ mov(r5, Operand(r4));
+    __ mov(r6, Operand(r4));
+    __ mov(r7, Operand(r4));
+    if (kR9Available == 1) {
+      __ mov(r9, Operand(r4));
+    }
 
-  // Exit the JS frame and remove the parameters (except function), and return.
-  // Respect ABI stack constraint.
-  __ LeaveInternalFrame();
+    // Invoke the code and pass argc as r0.
+    __ mov(r0, Operand(r3));
+    if (is_construct) {
+      __ Call(masm->isolate()->builtins()->JSConstructCall());
+    } else {
+      ParameterCount actual(r0);
+      __ InvokeFunction(r1, actual, CALL_FUNCTION,
+                        NullCallWrapper(), CALL_AS_METHOD);
+    }
+    // Exit the JS frame and remove the parameters (except function), and
+    // return.
+    // Respect ABI stack constraint.
+  }
   __ Jump(lr);
 
   // r0: result
@@ -1072,26 +1092,27 @@ void Builtins::Generate_JSConstructEntryTrampoline(MacroAssembler* masm) {
 
 void Builtins::Generate_LazyCompile(MacroAssembler* masm) {
   // Enter an internal frame.
-  __ EnterInternalFrame();
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
 
-  // Preserve the function.
-  __ push(r1);
-  // Push call kind information.
-  __ push(r5);
+    // Preserve the function.
+    __ push(r1);
+    // Push call kind information.
+    __ push(r5);
 
-  // Push the function on the stack as the argument to the runtime function.
-  __ push(r1);
-  __ CallRuntime(Runtime::kLazyCompile, 1);
-  // Calculate the entry point.
-  __ add(r2, r0, Operand(Code::kHeaderSize - kHeapObjectTag));
+    // Push the function on the stack as the argument to the runtime function.
+    __ push(r1);
+    __ CallRuntime(Runtime::kLazyCompile, 1);
+    // Calculate the entry point.
+    __ add(r2, r0, Operand(Code::kHeaderSize - kHeapObjectTag));
 
-  // Restore call kind information.
-  __ pop(r5);
-  // Restore saved function.
-  __ pop(r1);
+    // Restore call kind information.
+    __ pop(r5);
+    // Restore saved function.
+    __ pop(r1);
 
-  // Tear down temporary frame.
-  __ LeaveInternalFrame();
+    // Tear down internal frame.
+  }
 
   // Do a tail-call of the compiled function.
   __ Jump(r2);
@@ -1100,26 +1121,27 @@ void Builtins::Generate_LazyCompile(MacroAssembler* masm) {
 
 void Builtins::Generate_LazyRecompile(MacroAssembler* masm) {
   // Enter an internal frame.
-  __ EnterInternalFrame();
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
 
-  // Preserve the function.
-  __ push(r1);
-  // Push call kind information.
-  __ push(r5);
+    // Preserve the function.
+    __ push(r1);
+    // Push call kind information.
+    __ push(r5);
 
-  // Push the function on the stack as the argument to the runtime function.
-  __ push(r1);
-  __ CallRuntime(Runtime::kLazyRecompile, 1);
-  // Calculate the entry point.
-  __ add(r2, r0, Operand(Code::kHeaderSize - kHeapObjectTag));
+    // Push the function on the stack as the argument to the runtime function.
+    __ push(r1);
+    __ CallRuntime(Runtime::kLazyRecompile, 1);
+    // Calculate the entry point.
+    __ add(r2, r0, Operand(Code::kHeaderSize - kHeapObjectTag));
 
-  // Restore call kind information.
-  __ pop(r5);
-  // Restore saved function.
-  __ pop(r1);
+    // Restore call kind information.
+    __ pop(r5);
+    // Restore saved function.
+    __ pop(r1);
 
-  // Tear down temporary frame.
-  __ LeaveInternalFrame();
+    // Tear down internal frame.
+  }
 
   // Do a tail-call of the compiled function.
   __ Jump(r2);
@@ -1128,12 +1150,13 @@ void Builtins::Generate_LazyRecompile(MacroAssembler* masm) {
 
 static void Generate_NotifyDeoptimizedHelper(MacroAssembler* masm,
                                              Deoptimizer::BailoutType type) {
-  __ EnterInternalFrame();
-  // Pass the function and deoptimization type to the runtime system.
-  __ mov(r0, Operand(Smi::FromInt(static_cast<int>(type))));
-  __ push(r0);
-  __ CallRuntime(Runtime::kNotifyDeoptimized, 1);
-  __ LeaveInternalFrame();
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
+    // Pass the function and deoptimization type to the runtime system.
+    __ mov(r0, Operand(Smi::FromInt(static_cast<int>(type))));
+    __ push(r0);
+    __ CallRuntime(Runtime::kNotifyDeoptimized, 1);
+  }
 
   // Get the full codegen state from the stack and untag it -> r6.
   __ ldr(r6, MemOperand(sp, 0 * kPointerSize));
@@ -1173,9 +1196,10 @@ void Builtins::Generate_NotifyOSR(MacroAssembler* masm) {
   // the registers without worrying about which of them contain
   // pointers. This seems a bit fragile.
   __ stm(db_w, sp, kJSCallerSaved | kCalleeSaved | lr.bit() | fp.bit());
-  __ EnterInternalFrame();
-  __ CallRuntime(Runtime::kNotifyOSR, 0);
-  __ LeaveInternalFrame();
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
+    __ CallRuntime(Runtime::kNotifyOSR, 0);
+  }
   __ ldm(ia_w, sp, kJSCallerSaved | kCalleeSaved | lr.bit() | fp.bit());
   __ Ret();
 }
@@ -1191,10 +1215,11 @@ void Builtins::Generate_OnStackReplacement(MacroAssembler* masm) {
   // Lookup the function in the JavaScript frame and push it as an
   // argument to the on-stack replacement function.
   __ ldr(r0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
-  __ EnterInternalFrame();
-  __ push(r0);
-  __ CallRuntime(Runtime::kCompileForOnStackReplacement, 1);
-  __ LeaveInternalFrame();
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
+    __ push(r0);
+    __ CallRuntime(Runtime::kCompileForOnStackReplacement, 1);
+  }
 
   // If the result was -1 it means that we couldn't optimize the
   // function. Just return and continue in the unoptimized version.
@@ -1276,17 +1301,23 @@ void Builtins::Generate_FunctionCall(MacroAssembler* masm) {
     __ b(ge, &shift_arguments);
 
     __ bind(&convert_to_object);
-    __ EnterInternalFrame();  // In order to preserve argument count.
-    __ mov(r0, Operand(r0, LSL, kSmiTagSize));  // Smi-tagged.
-    __ push(r0);
 
-    __ push(r2);
-    __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
-    __ mov(r2, r0);
+    {
+      // Enter an internal frame in order to preserve argument count.
+      FrameScope scope(masm, StackFrame::INTERNAL);
+      __ mov(r0, Operand(r0, LSL, kSmiTagSize));  // Smi-tagged.
+      __ push(r0);
+
+      __ push(r2);
+      __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
+      __ mov(r2, r0);
+
+      __ pop(r0);
+      __ mov(r0, Operand(r0, ASR, kSmiTagSize));
+
+      // Exit the internal frame.
+    }
 
-    __ pop(r0);
-    __ mov(r0, Operand(r0, ASR, kSmiTagSize));
-    __ LeaveInternalFrame();
     // Restore the function to r1, and the flag to r4.
     __ ldr(r1, MemOperand(sp, r0, LSL, kPointerSizeLog2));
     __ mov(r4, Operand(0, RelocInfo::NONE));
@@ -1406,156 +1437,157 @@ void Builtins::Generate_FunctionApply(MacroAssembler* masm) {
   const int kRecvOffset     =  3 * kPointerSize;
   const int kFunctionOffset =  4 * kPointerSize;
 
-  __ EnterInternalFrame();
+  {
+    FrameScope frame_scope(masm, StackFrame::INTERNAL);
 
-  __ ldr(r0, MemOperand(fp, kFunctionOffset));  // get the function
-  __ push(r0);
-  __ ldr(r0, MemOperand(fp, kArgsOffset));  // get the args array
-  __ push(r0);
-  __ InvokeBuiltin(Builtins::APPLY_PREPARE, CALL_FUNCTION);
-
-  // Check the stack for overflow. We are not trying to catch
-  // interruptions (e.g. debug break and preemption) here, so the "real stack
-  // limit" is checked.
-  Label okay;
-  __ LoadRoot(r2, Heap::kRealStackLimitRootIndex);
-  // Make r2 the space we have left. The stack might already be overflowed
-  // here which will cause r2 to become negative.
-  __ sub(r2, sp, r2);
-  // Check if the arguments will overflow the stack.
-  __ cmp(r2, Operand(r0, LSL, kPointerSizeLog2 - kSmiTagSize));
-  __ b(gt, &okay);  // Signed comparison.
-
-  // Out of stack space.
-  __ ldr(r1, MemOperand(fp, kFunctionOffset));
-  __ push(r1);
-  __ push(r0);
-  __ InvokeBuiltin(Builtins::APPLY_OVERFLOW, CALL_FUNCTION);
-  // End of stack check.
+    __ ldr(r0, MemOperand(fp, kFunctionOffset));  // get the function
+    __ push(r0);
+    __ ldr(r0, MemOperand(fp, kArgsOffset));  // get the args array
+    __ push(r0);
+    __ InvokeBuiltin(Builtins::APPLY_PREPARE, CALL_FUNCTION);
+
+    // Check the stack for overflow. We are not trying to catch
+    // interruptions (e.g. debug break and preemption) here, so the "real stack
+    // limit" is checked.
+    Label okay;
+    __ LoadRoot(r2, Heap::kRealStackLimitRootIndex);
+    // Make r2 the space we have left. The stack might already be overflowed
+    // here which will cause r2 to become negative.
+    __ sub(r2, sp, r2);
+    // Check if the arguments will overflow the stack.
+    __ cmp(r2, Operand(r0, LSL, kPointerSizeLog2 - kSmiTagSize));
+    __ b(gt, &okay);  // Signed comparison.
+
+    // Out of stack space.
+    __ ldr(r1, MemOperand(fp, kFunctionOffset));
+    __ push(r1);
+    __ push(r0);
+    __ InvokeBuiltin(Builtins::APPLY_OVERFLOW, CALL_FUNCTION);
+    // End of stack check.
 
-  // Push current limit and index.
-  __ bind(&okay);
-  __ push(r0);  // limit
-  __ mov(r1, Operand(0, RelocInfo::NONE));  // initial index
-  __ push(r1);
+    // Push current limit and index.
+    __ bind(&okay);
+    __ push(r0);  // limit
+    __ mov(r1, Operand(0, RelocInfo::NONE));  // initial index
+    __ push(r1);
 
-  // Get the receiver.
-  __ ldr(r0, MemOperand(fp, kRecvOffset));
+    // Get the receiver.
+    __ ldr(r0, MemOperand(fp, kRecvOffset));
 
-  // Check that the function is a JS function (otherwise it must be a proxy).
-  Label push_receiver;
-  __ ldr(r1, MemOperand(fp, kFunctionOffset));
-  __ CompareObjectType(r1, r2, r2, JS_FUNCTION_TYPE);
-  __ b(ne, &push_receiver);
+    // Check that the function is a JS function (otherwise it must be a proxy).
+    Label push_receiver;
+    __ ldr(r1, MemOperand(fp, kFunctionOffset));
+    __ CompareObjectType(r1, r2, r2, JS_FUNCTION_TYPE);
+    __ b(ne, &push_receiver);
 
-  // Change context eagerly to get the right global object if necessary.
-  __ ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
-  // Load the shared function info while the function is still in r1.
-  __ ldr(r2, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
+    // Change context eagerly to get the right global object if necessary.
+    __ ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
+    // Load the shared function info while the function is still in r1.
+    __ ldr(r2, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
 
-  // Compute the receiver.
-  // Do not transform the receiver for strict mode functions.
-  Label call_to_object, use_global_receiver;
-  __ ldr(r2, FieldMemOperand(r2, SharedFunctionInfo::kCompilerHintsOffset));
-  __ tst(r2, Operand(1 << (SharedFunctionInfo::kStrictModeFunction +
-                           kSmiTagSize)));
-  __ b(ne, &push_receiver);
-
-  // Do not transform the receiver for strict mode functions.
-  __ tst(r2, Operand(1 << (SharedFunctionInfo::kNative + kSmiTagSize)));
-  __ b(ne, &push_receiver);
-
-  // Compute the receiver in non-strict mode.
-  __ JumpIfSmi(r0, &call_to_object);
-  __ LoadRoot(r1, Heap::kNullValueRootIndex);
-  __ cmp(r0, r1);
-  __ b(eq, &use_global_receiver);
-  __ LoadRoot(r1, Heap::kUndefinedValueRootIndex);
-  __ cmp(r0, r1);
-  __ b(eq, &use_global_receiver);
-
-  // Check if the receiver is already a JavaScript object.
-  // r0: receiver
-  STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
-  __ CompareObjectType(r0, r1, r1, FIRST_SPEC_OBJECT_TYPE);
-  __ b(ge, &push_receiver);
-
-  // Convert the receiver to a regular object.
-  // r0: receiver
-  __ bind(&call_to_object);
-  __ push(r0);
-  __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
-  __ b(&push_receiver);
-
-  // Use the current global receiver object as the receiver.
-  __ bind(&use_global_receiver);
-  const int kGlobalOffset =
-      Context::kHeaderSize + Context::GLOBAL_INDEX * kPointerSize;
-  __ ldr(r0, FieldMemOperand(cp, kGlobalOffset));
-  __ ldr(r0, FieldMemOperand(r0, GlobalObject::kGlobalContextOffset));
-  __ ldr(r0, FieldMemOperand(r0, kGlobalOffset));
-  __ ldr(r0, FieldMemOperand(r0, GlobalObject::kGlobalReceiverOffset));
-
-  // Push the receiver.
-  // r0: receiver
-  __ bind(&push_receiver);
-  __ push(r0);
+    // Compute the receiver.
+    // Do not transform the receiver for strict mode functions.
+    Label call_to_object, use_global_receiver;
+    __ ldr(r2, FieldMemOperand(r2, SharedFunctionInfo::kCompilerHintsOffset));
+    __ tst(r2, Operand(1 << (SharedFunctionInfo::kStrictModeFunction +
+                             kSmiTagSize)));
+    __ b(ne, &push_receiver);
 
-  // Copy all arguments from the array to the stack.
-  Label entry, loop;
-  __ ldr(r0, MemOperand(fp, kIndexOffset));
-  __ b(&entry);
+    // Do not transform the receiver for strict mode functions.
+    __ tst(r2, Operand(1 << (SharedFunctionInfo::kNative + kSmiTagSize)));
+    __ b(ne, &push_receiver);
 
-  // Load the current argument from the arguments array and push it to the
-  // stack.
-  // r0: current argument index
-  __ bind(&loop);
-  __ ldr(r1, MemOperand(fp, kArgsOffset));
-  __ push(r1);
-  __ push(r0);
+    // Compute the receiver in non-strict mode.
+    __ JumpIfSmi(r0, &call_to_object);
+    __ LoadRoot(r1, Heap::kNullValueRootIndex);
+    __ cmp(r0, r1);
+    __ b(eq, &use_global_receiver);
+    __ LoadRoot(r1, Heap::kUndefinedValueRootIndex);
+    __ cmp(r0, r1);
+    __ b(eq, &use_global_receiver);
 
-  // Call the runtime to access the property in the arguments array.
-  __ CallRuntime(Runtime::kGetProperty, 2);
-  __ push(r0);
+    // Check if the receiver is already a JavaScript object.
+    // r0: receiver
+    STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
+    __ CompareObjectType(r0, r1, r1, FIRST_SPEC_OBJECT_TYPE);
+    __ b(ge, &push_receiver);
 
-  // Use inline caching to access the arguments.
-  __ ldr(r0, MemOperand(fp, kIndexOffset));
-  __ add(r0, r0, Operand(1 << kSmiTagSize));
-  __ str(r0, MemOperand(fp, kIndexOffset));
+    // Convert the receiver to a regular object.
+    // r0: receiver
+    __ bind(&call_to_object);
+    __ push(r0);
+    __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
+    __ b(&push_receiver);
 
-  // Test if the copy loop has finished copying all the elements from the
-  // arguments object.
-  __ bind(&entry);
-  __ ldr(r1, MemOperand(fp, kLimitOffset));
-  __ cmp(r0, r1);
-  __ b(ne, &loop);
-
-  // Invoke the function.
-  Label call_proxy;
-  ParameterCount actual(r0);
-  __ mov(r0, Operand(r0, ASR, kSmiTagSize));
-  __ ldr(r1, MemOperand(fp, kFunctionOffset));
-  __ CompareObjectType(r1, r2, r2, JS_FUNCTION_TYPE);
-  __ b(ne, &call_proxy);
-  __ InvokeFunction(r1, actual, CALL_FUNCTION,
-                    NullCallWrapper(), CALL_AS_METHOD);
+    // Use the current global receiver object as the receiver.
+    __ bind(&use_global_receiver);
+    const int kGlobalOffset =
+        Context::kHeaderSize + Context::GLOBAL_INDEX * kPointerSize;
+    __ ldr(r0, FieldMemOperand(cp, kGlobalOffset));
+    __ ldr(r0, FieldMemOperand(r0, GlobalObject::kGlobalContextOffset));
+    __ ldr(r0, FieldMemOperand(r0, kGlobalOffset));
+    __ ldr(r0, FieldMemOperand(r0, GlobalObject::kGlobalReceiverOffset));
+
+    // Push the receiver.
+    // r0: receiver
+    __ bind(&push_receiver);
+    __ push(r0);
 
-  // Tear down the internal frame and remove function, receiver and args.
-  __ LeaveInternalFrame();
-  __ add(sp, sp, Operand(3 * kPointerSize));
-  __ Jump(lr);
+    // Copy all arguments from the array to the stack.
+    Label entry, loop;
+    __ ldr(r0, MemOperand(fp, kIndexOffset));
+    __ b(&entry);
 
-  // Invoke the function proxy.
-  __ bind(&call_proxy);
-  __ push(r1);  // add function proxy as last argument
-  __ add(r0, r0, Operand(1));
-  __ mov(r2, Operand(0, RelocInfo::NONE));
-  __ SetCallKind(r5, CALL_AS_METHOD);
-  __ GetBuiltinEntry(r3, Builtins::CALL_FUNCTION_PROXY);
-  __ Call(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
-          RelocInfo::CODE_TARGET);
+    // Load the current argument from the arguments array and push it to the
+    // stack.
+    // r0: current argument index
+    __ bind(&loop);
+    __ ldr(r1, MemOperand(fp, kArgsOffset));
+    __ push(r1);
+    __ push(r0);
+
+    // Call the runtime to access the property in the arguments array.
+    __ CallRuntime(Runtime::kGetProperty, 2);
+    __ push(r0);
+
+    // Use inline caching to access the arguments.
+    __ ldr(r0, MemOperand(fp, kIndexOffset));
+    __ add(r0, r0, Operand(1 << kSmiTagSize));
+    __ str(r0, MemOperand(fp, kIndexOffset));
 
-  __ LeaveInternalFrame();
+    // Test if the copy loop has finished copying all the elements from the
+    // arguments object.
+    __ bind(&entry);
+    __ ldr(r1, MemOperand(fp, kLimitOffset));
+    __ cmp(r0, r1);
+    __ b(ne, &loop);
+
+    // Invoke the function.
+    Label call_proxy;
+    ParameterCount actual(r0);
+    __ mov(r0, Operand(r0, ASR, kSmiTagSize));
+    __ ldr(r1, MemOperand(fp, kFunctionOffset));
+    __ CompareObjectType(r1, r2, r2, JS_FUNCTION_TYPE);
+    __ b(ne, &call_proxy);
+    __ InvokeFunction(r1, actual, CALL_FUNCTION,
+                      NullCallWrapper(), CALL_AS_METHOD);
+
+    frame_scope.GenerateLeaveFrame();
+    __ add(sp, sp, Operand(3 * kPointerSize));
+    __ Jump(lr);
+
+    // Invoke the function proxy.
+    __ bind(&call_proxy);
+    __ push(r1);  // add function proxy as last argument
+    __ add(r0, r0, Operand(1));
+    __ mov(r2, Operand(0, RelocInfo::NONE));
+    __ SetCallKind(r5, CALL_AS_METHOD);
+    __ GetBuiltinEntry(r3, Builtins::CALL_FUNCTION_PROXY);
+    __ Call(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
+            RelocInfo::CODE_TARGET);
+
+    // Tear down the internal frame and remove function, receiver and args.
+  }
   __ add(sp, sp, Operand(3 * kPointerSize));
   __ Jump(lr);
 }
diff --git a/deps/v8/src/arm/code-stubs-arm.cc b/deps/v8/src/arm/code-stubs-arm.cc
index e65f6d9b6..44923a184 100644
--- a/deps/v8/src/arm/code-stubs-arm.cc
+++ b/deps/v8/src/arm/code-stubs-arm.cc
@@ -189,6 +189,72 @@ void FastNewContextStub::Generate(MacroAssembler* masm) {
 }
 
 
+void FastNewBlockContextStub::Generate(MacroAssembler* masm) {
+  // Stack layout on entry:
+  //
+  // [sp]: function.
+  // [sp + kPointerSize]: serialized scope info
+
+  // Try to allocate the context in new space.
+  Label gc;
+  int length = slots_ + Context::MIN_CONTEXT_SLOTS;
+  __ AllocateInNewSpace(FixedArray::SizeFor(length),
+                        r0, r1, r2, &gc, TAG_OBJECT);
+
+  // Load the function from the stack.
+  __ ldr(r3, MemOperand(sp, 0));
+
+  // Load the serialized scope info from the stack.
+  __ ldr(r1, MemOperand(sp, 1 * kPointerSize));
+
+  // Setup the object header.
+  __ LoadRoot(r2, Heap::kBlockContextMapRootIndex);
+  __ str(r2, FieldMemOperand(r0, HeapObject::kMapOffset));
+  __ mov(r2, Operand(Smi::FromInt(length)));
+  __ str(r2, FieldMemOperand(r0, FixedArray::kLengthOffset));
+
+  // If this block context is nested in the global context we get a smi
+  // sentinel instead of a function. The block context should get the
+  // canonical empty function of the global context as its closure which
+  // we still have to look up.
+  Label after_sentinel;
+  __ JumpIfNotSmi(r3, &after_sentinel);
+  if (FLAG_debug_code) {
+    const char* message = "Expected 0 as a Smi sentinel";
+    __ cmp(r3, Operand::Zero());
+    __ Assert(eq, message);
+  }
+  __ ldr(r3, GlobalObjectOperand());
+  __ ldr(r3, FieldMemOperand(r3, GlobalObject::kGlobalContextOffset));
+  __ ldr(r3, ContextOperand(r3, Context::CLOSURE_INDEX));
+  __ bind(&after_sentinel);
+
+  // Setup the fixed slots.
+  __ str(r3, ContextOperand(r0, Context::CLOSURE_INDEX));
+  __ str(cp, ContextOperand(r0, Context::PREVIOUS_INDEX));
+  __ str(r1, ContextOperand(r0, Context::EXTENSION_INDEX));
+
+  // Copy the global object from the previous context.
+  __ ldr(r1, ContextOperand(cp, Context::GLOBAL_INDEX));
+  __ str(r1, ContextOperand(r0, Context::GLOBAL_INDEX));
+
+  // Initialize the rest of the slots to the hole value.
+  __ LoadRoot(r1, Heap::kTheHoleValueRootIndex);
+  for (int i = 0; i < slots_; i++) {
+    __ str(r1, ContextOperand(r0, i + Context::MIN_CONTEXT_SLOTS));
+  }
+
+  // Remove the on-stack argument and return.
+  __ mov(cp, r0);
+  __ add(sp, sp, Operand(2 * kPointerSize));
+  __ Ret();
+
+  // Need to collect. Call into runtime system.
+  __ bind(&gc);
+  __ TailCallRuntime(Runtime::kPushBlockContext, 2, 1);
+}
+
+
 void FastCloneShallowArrayStub::Generate(MacroAssembler* masm) {
   // Stack layout on entry:
   //
@@ -838,9 +904,11 @@ void FloatingPointHelper::CallCCodeForDoubleOperation(
     __ vmov(d0, r0, r1);
     __ vmov(d1, r2, r3);
   }
-  // Call C routine that may not cause GC or other trouble.
-  __ CallCFunction(ExternalReference::double_fp_operation(op, masm->isolate()),
-                   0, 2);
+  {
+    AllowExternalCallThatCantCauseGC scope(masm);
+    __ CallCFunction(
+        ExternalReference::double_fp_operation(op, masm->isolate()), 0, 2);
+  }
   // Store answer in the overwritable heap number. Double returned in
   // registers r0 and r1 or in d0.
   if (masm->use_eabi_hardfloat()) {
@@ -857,6 +925,29 @@ void FloatingPointHelper::CallCCodeForDoubleOperation(
 }
 
 
+bool WriteInt32ToHeapNumberStub::IsPregenerated() {
+  // These variants are compiled ahead of time.  See next method.
+  if (the_int_.is(r1) && the_heap_number_.is(r0) && scratch_.is(r2)) {
+    return true;
+  }
+  if (the_int_.is(r2) && the_heap_number_.is(r0) && scratch_.is(r3)) {
+    return true;
+  }
+  // Other register combinations are generated as and when they are needed,
+  // so it is unsafe to call them from stubs (we can't generate a stub while
+  // we are generating a stub).
+  return false;
+}
+
+
+void WriteInt32ToHeapNumberStub::GenerateFixedRegStubsAheadOfTime() {
+  WriteInt32ToHeapNumberStub stub1(r1, r0, r2);
+  WriteInt32ToHeapNumberStub stub2(r2, r0, r3);
+  stub1.GetCode()->set_is_pregenerated(true);
+  stub2.GetCode()->set_is_pregenerated(true);
+}
+
+
 // See comment for class.
 void WriteInt32ToHeapNumberStub::Generate(MacroAssembler* masm) {
   Label max_negative_int;
@@ -1197,6 +1288,8 @@ static void EmitTwoNonNanDoubleComparison(MacroAssembler* masm,
       __ vmov(d0, r0, r1);
       __ vmov(d1, r2, r3);
     }
+
+    AllowExternalCallThatCantCauseGC scope(masm);
     __ CallCFunction(ExternalReference::compare_doubles(masm->isolate()),
                      0, 2);
     __ pop(pc);  // Return.
@@ -1214,7 +1307,7 @@ static void EmitStrictTwoHeapObjectCompare(MacroAssembler* masm,
     // If either operand is a JS object or an oddball value, then they are
     // not equal since their pointers are different.
     // There is no test for undetectability in strict equality.
-    STATIC_ASSERT(LAST_TYPE == LAST_CALLABLE_SPEC_OBJECT_TYPE);
+    STATIC_ASSERT(LAST_TYPE == LAST_SPEC_OBJECT_TYPE);
     Label first_non_object;
     // Get the type of the first operand into r2 and compare it with
     // FIRST_SPEC_OBJECT_TYPE.
@@ -1606,6 +1699,8 @@ void CompareStub::Generate(MacroAssembler* masm) {
 // The stub expects its argument in the tos_ register and returns its result in
 // it, too: zero for false, and a non-zero value for true.
 void ToBooleanStub::Generate(MacroAssembler* masm) {
+  // This stub overrides SometimesSetsUpAFrame() to return false.  That means
+  // we cannot call anything that could cause a GC from this stub.
   // This stub uses VFP3 instructions.
   CpuFeatures::Scope scope(VFP3);
 
@@ -1713,6 +1808,41 @@ void ToBooleanStub::GenerateTypeTransition(MacroAssembler* masm) {
 }
 
 
+void StoreBufferOverflowStub::Generate(MacroAssembler* masm) {
+  // We don't allow a GC during a store buffer overflow so there is no need to
+  // store the registers in any particular way, but we do have to store and
+  // restore them.
+  __ stm(db_w, sp, kCallerSaved | lr.bit());
+  if (save_doubles_ == kSaveFPRegs) {
+    CpuFeatures::Scope scope(VFP3);
+    __ sub(sp, sp, Operand(kDoubleSize * DwVfpRegister::kNumRegisters));
+    for (int i = 0; i < DwVfpRegister::kNumRegisters; i++) {
+      DwVfpRegister reg = DwVfpRegister::from_code(i);
+      __ vstr(reg, MemOperand(sp, i * kDoubleSize));
+    }
+  }
+  const int argument_count = 1;
+  const int fp_argument_count = 0;
+  const Register scratch = r1;
+
+  AllowExternalCallThatCantCauseGC scope(masm);
+  __ PrepareCallCFunction(argument_count, fp_argument_count, scratch);
+  __ mov(r0, Operand(ExternalReference::isolate_address()));
+  __ CallCFunction(
+      ExternalReference::store_buffer_overflow_function(masm->isolate()),
+      argument_count);
+  if (save_doubles_ == kSaveFPRegs) {
+    CpuFeatures::Scope scope(VFP3);
+    for (int i = 0; i < DwVfpRegister::kNumRegisters; i++) {
+      DwVfpRegister reg = DwVfpRegister::from_code(i);
+      __ vldr(reg, MemOperand(sp, i * kDoubleSize));
+    }
+    __ add(sp, sp, Operand(kDoubleSize * DwVfpRegister::kNumRegisters));
+  }
+  __ ldm(ia_w, sp, kCallerSaved | pc.bit());  // Also pop pc to get Ret(0).
+}
+
+
 void UnaryOpStub::PrintName(StringStream* stream) {
   const char* op_name = Token::Name(op_);
   const char* overwrite_name = NULL;  // Make g++ happy.
@@ -1866,12 +1996,13 @@ void UnaryOpStub::GenerateHeapNumberCodeSub(MacroAssembler* masm,
     __ jmp(&heapnumber_allocated);
 
     __ bind(&slow_allocate_heapnumber);
-    __ EnterInternalFrame();
-    __ push(r0);
-    __ CallRuntime(Runtime::kNumberAlloc, 0);
-    __ mov(r1, Operand(r0));
-    __ pop(r0);
-    __ LeaveInternalFrame();
+    {
+      FrameScope scope(masm, StackFrame::INTERNAL);
+      __ push(r0);
+      __ CallRuntime(Runtime::kNumberAlloc, 0);
+      __ mov(r1, Operand(r0));
+      __ pop(r0);
+    }
 
     __ bind(&heapnumber_allocated);
     __ ldr(r3, FieldMemOperand(r0, HeapNumber::kMantissaOffset));
@@ -1912,13 +2043,14 @@ void UnaryOpStub::GenerateHeapNumberCodeBitNot(
     __ jmp(&heapnumber_allocated);
 
     __ bind(&slow_allocate_heapnumber);
-    __ EnterInternalFrame();
-    __ push(r0);  // Push the heap number, not the untagged int32.
-    __ CallRuntime(Runtime::kNumberAlloc, 0);
-    __ mov(r2, r0);  // Move the new heap number into r2.
-    // Get the heap number into r0, now that the new heap number is in r2.
-    __ pop(r0);
-    __ LeaveInternalFrame();
+    {
+      FrameScope scope(masm, StackFrame::INTERNAL);
+      __ push(r0);  // Push the heap number, not the untagged int32.
+      __ CallRuntime(Runtime::kNumberAlloc, 0);
+      __ mov(r2, r0);  // Move the new heap number into r2.
+      // Get the heap number into r0, now that the new heap number is in r2.
+      __ pop(r0);
+    }
 
     // Convert the heap number in r0 to an untagged integer in r1.
     // This can't go slow-case because it's the same number we already
@@ -2028,6 +2160,10 @@ void BinaryOpStub::GenerateTypeTransitionWithSavedArgs(
 
 
 void BinaryOpStub::Generate(MacroAssembler* masm) {
+  // Explicitly allow generation of nested stubs. It is safe here because
+  // generation code does not use any raw pointers.
+  AllowStubCallsScope allow_stub_calls(masm, true);
+
   switch (operands_type_) {
     case BinaryOpIC::UNINITIALIZED:
       GenerateTypeTransition(masm);
@@ -3133,10 +3269,11 @@ void TranscendentalCacheStub::Generate(MacroAssembler* masm) {
     __ LoadRoot(r5, Heap::kHeapNumberMapRootIndex);
     __ AllocateHeapNumber(r0, scratch0, scratch1, r5, &skip_cache);
     __ vstr(d2, FieldMemOperand(r0, HeapNumber::kValueOffset));
-    __ EnterInternalFrame();
-    __ push(r0);
-    __ CallRuntime(RuntimeFunction(), 1);
-    __ LeaveInternalFrame();
+    {
+      FrameScope scope(masm, StackFrame::INTERNAL);
+      __ push(r0);
+      __ CallRuntime(RuntimeFunction(), 1);
+    }
     __ vldr(d2, FieldMemOperand(r0, HeapNumber::kValueOffset));
     __ Ret();
 
@@ -3149,14 +3286,15 @@ void TranscendentalCacheStub::Generate(MacroAssembler* masm) {
 
     // We return the value in d2 without adding it to the cache, but
     // we cause a scavenging GC so that future allocations will succeed.
-    __ EnterInternalFrame();
-
-    // Allocate an aligned object larger than a HeapNumber.
-    ASSERT(4 * kPointerSize >= HeapNumber::kSize);
-    __ mov(scratch0, Operand(4 * kPointerSize));
-    __ push(scratch0);
-    __ CallRuntimeSaveDoubles(Runtime::kAllocateInNewSpace);
-    __ LeaveInternalFrame();
+    {
+      FrameScope scope(masm, StackFrame::INTERNAL);
+
+      // Allocate an aligned object larger than a HeapNumber.
+      ASSERT(4 * kPointerSize >= HeapNumber::kSize);
+      __ mov(scratch0, Operand(4 * kPointerSize));
+      __ push(scratch0);
+      __ CallRuntimeSaveDoubles(Runtime::kAllocateInNewSpace);
+    }
     __ Ret();
   }
 }
@@ -3173,6 +3311,7 @@ void TranscendentalCacheStub::GenerateCallCFunction(MacroAssembler* masm,
   } else {
     __ vmov(r0, r1, d2);
   }
+  AllowExternalCallThatCantCauseGC scope(masm);
   switch (type_) {
     case TranscendentalCache::SIN:
       __ CallCFunction(ExternalReference::math_sin_double_function(isolate),
@@ -3268,11 +3407,14 @@ void MathPowStub::Generate(MacroAssembler* masm) {
     __ push(lr);
     __ PrepareCallCFunction(1, 1, scratch);
     __ SetCallCDoubleArguments(double_base, exponent);
-    __ CallCFunction(
-        ExternalReference::power_double_int_function(masm->isolate()),
-        1, 1);
-    __ pop(lr);
-    __ GetCFunctionDoubleResult(double_result);
+    {
+      AllowExternalCallThatCantCauseGC scope(masm);
+      __ CallCFunction(
+          ExternalReference::power_double_int_function(masm->isolate()),
+          1, 1);
+      __ pop(lr);
+      __ GetCFunctionDoubleResult(double_result);
+    }
     __ vstr(double_result,
             FieldMemOperand(heapnumber, HeapNumber::kValueOffset));
     __ mov(r0, heapnumber);
@@ -3298,11 +3440,14 @@ void MathPowStub::Generate(MacroAssembler* masm) {
     __ push(lr);
     __ PrepareCallCFunction(0, 2, scratch);
     __ SetCallCDoubleArguments(double_base, double_exponent);
-    __ CallCFunction(
-        ExternalReference::power_double_double_function(masm->isolate()),
-        0, 2);
-    __ pop(lr);
-    __ GetCFunctionDoubleResult(double_result);
+    {
+      AllowExternalCallThatCantCauseGC scope(masm);
+      __ CallCFunction(
+          ExternalReference::power_double_double_function(masm->isolate()),
+          0, 2);
+      __ pop(lr);
+      __ GetCFunctionDoubleResult(double_result);
+    }
     __ vstr(double_result,
             FieldMemOperand(heapnumber, HeapNumber::kValueOffset));
     __ mov(r0, heapnumber);
@@ -3319,6 +3464,37 @@ bool CEntryStub::NeedsImmovableCode() {
 }
 
 
+bool CEntryStub::IsPregenerated() {
+  return (!save_doubles_ || ISOLATE->fp_stubs_generated()) &&
+          result_size_ == 1;
+}
+
+
+void CodeStub::GenerateStubsAheadOfTime() {
+  CEntryStub::GenerateAheadOfTime();
+  WriteInt32ToHeapNumberStub::GenerateFixedRegStubsAheadOfTime();
+  StoreBufferOverflowStub::GenerateFixedRegStubsAheadOfTime();
+  RecordWriteStub::GenerateFixedRegStubsAheadOfTime();
+}
+
+
+void CodeStub::GenerateFPStubs() {
+  CEntryStub save_doubles(1, kSaveFPRegs);
+  Handle<Code> code = save_doubles.GetCode();
+  code->set_is_pregenerated(true);
+  StoreBufferOverflowStub stub(kSaveFPRegs);
+  stub.GetCode()->set_is_pregenerated(true);
+  code->GetIsolate()->set_fp_stubs_generated(true);
+}
+
+
+void CEntryStub::GenerateAheadOfTime() {
+  CEntryStub stub(1, kDontSaveFPRegs);
+  Handle<Code> code = stub.GetCode();
+  code->set_is_pregenerated(true);
+}
+
+
 void CEntryStub::GenerateThrowTOS(MacroAssembler* masm) {
   __ Throw(r0);
 }
@@ -3430,8 +3606,7 @@ void CEntryStub::GenerateCore(MacroAssembler* masm,
   __ b(eq, throw_out_of_memory_exception);
 
   // Retrieve the pending exception and clear the variable.
-  __ mov(ip, Operand(ExternalReference::the_hole_value_location(isolate)));
-  __ ldr(r3, MemOperand(ip));
+  __ mov(r3, Operand(isolate->factory()->the_hole_value()));
   __ mov(ip, Operand(ExternalReference(Isolate::kPendingExceptionAddress,
                                        isolate)));
   __ ldr(r0, MemOperand(ip));
@@ -3469,6 +3644,7 @@ void CEntryStub::Generate(MacroAssembler* masm) {
   __ sub(r6, r6, Operand(kPointerSize));
 
   // Enter the exit frame that transitions from JavaScript to C++.
+  FrameScope scope(masm, StackFrame::MANUAL);
   __ EnterExitFrame(save_doubles_);
 
   // Setup argc and the builtin function in callee-saved registers.
@@ -3613,8 +3789,7 @@ void JSEntryStub::GenerateBody(MacroAssembler* masm, bool is_construct) {
   // saved values before returning a failure to C.
 
   // Clear any pending exceptions.
-  __ mov(ip, Operand(ExternalReference::the_hole_value_location(isolate)));
-  __ ldr(r5, MemOperand(ip));
+  __ mov(r5, Operand(isolate->factory()->the_hole_value()));
   __ mov(ip, Operand(ExternalReference(Isolate::kPendingExceptionAddress,
                                        isolate)));
   __ str(r5, MemOperand(ip));
@@ -3851,10 +4026,11 @@ void InstanceofStub::Generate(MacroAssembler* masm) {
     }
   __ InvokeBuiltin(Builtins::INSTANCE_OF, JUMP_FUNCTION);
   } else {
-    __ EnterInternalFrame();
-    __ Push(r0, r1);
-    __ InvokeBuiltin(Builtins::INSTANCE_OF, CALL_FUNCTION);
-    __ LeaveInternalFrame();
+    {
+      FrameScope scope(masm, StackFrame::INTERNAL);
+      __ Push(r0, r1);
+      __ InvokeBuiltin(Builtins::INSTANCE_OF, CALL_FUNCTION);
+    }
     __ cmp(r0, Operand::Zero());
     __ LoadRoot(r0, Heap::kTrueValueRootIndex, eq);
     __ LoadRoot(r0, Heap::kFalseValueRootIndex, ne);
@@ -4250,10 +4426,6 @@ void RegExpExecStub::Generate(MacroAssembler* masm) {
 #ifdef V8_INTERPRETED_REGEXP
   __ TailCallRuntime(Runtime::kRegExpExec, 4, 1);
 #else  // V8_INTERPRETED_REGEXP
-  if (!FLAG_regexp_entry_native) {
-    __ TailCallRuntime(Runtime::kRegExpExec, 4, 1);
-    return;
-  }
 
   // Stack frame on entry.
   //  sp[0]: last_match_info (expected JSArray)
@@ -4480,8 +4652,7 @@ void RegExpExecStub::Generate(MacroAssembler* masm) {
 
   // For arguments 4 and 3 get string length, calculate start of string data and
   // calculate the shift of the index (0 for ASCII and 1 for two byte).
-  STATIC_ASSERT(SeqAsciiString::kHeaderSize == SeqTwoByteString::kHeaderSize);
-  __ add(r8, subject, Operand(SeqAsciiString::kHeaderSize - kHeapObjectTag));
+  __ add(r8, subject, Operand(SeqString::kHeaderSize - kHeapObjectTag));
   __ eor(r3, r3, Operand(1));
   // Load the length from the original subject string from the previous stack
   // frame. Therefore we have to use fp, which points exactly to two pointer
@@ -4532,8 +4703,7 @@ void RegExpExecStub::Generate(MacroAssembler* masm) {
   // stack overflow (on the backtrack stack) was detected in RegExp code but
   // haven't created the exception yet. Handle that in the runtime system.
   // TODO(592): Rerunning the RegExp to get the stack overflow exception.
-  __ mov(r1, Operand(ExternalReference::the_hole_value_location(isolate)));
-  __ ldr(r1, MemOperand(r1, 0));
+  __ mov(r1, Operand(isolate->factory()->the_hole_value()));
   __ mov(r2, Operand(ExternalReference(Isolate::kPendingExceptionAddress,
                                        isolate)));
   __ ldr(r0, MemOperand(r2, 0));
@@ -4575,16 +4745,25 @@ void RegExpExecStub::Generate(MacroAssembler* masm) {
   __ str(r2, FieldMemOperand(last_match_info_elements,
                              RegExpImpl::kLastCaptureCountOffset));
   // Store last subject and last input.
-  __ mov(r3, last_match_info_elements);  // Moved up to reduce latency.
   __ str(subject,
          FieldMemOperand(last_match_info_elements,
                          RegExpImpl::kLastSubjectOffset));
-  __ RecordWrite(r3, Operand(RegExpImpl::kLastSubjectOffset), r2, r7);
+  __ mov(r2, subject);
+  __ RecordWriteField(last_match_info_elements,
+                      RegExpImpl::kLastSubjectOffset,
+                      r2,
+                      r7,
+                      kLRHasNotBeenSaved,
+                      kDontSaveFPRegs);
   __ str(subject,
          FieldMemOperand(last_match_info_elements,
                          RegExpImpl::kLastInputOffset));
-  __ mov(r3, last_match_info_elements);
-  __ RecordWrite(r3, Operand(RegExpImpl::kLastInputOffset), r2, r7);
+  __ RecordWriteField(last_match_info_elements,
+                      RegExpImpl::kLastInputOffset,
+                      subject,
+                      r7,
+                      kLRHasNotBeenSaved,
+                      kDontSaveFPRegs);
 
   // Get the static offsets vector filled by the native regexp code.
   ExternalReference address_of_static_offsets_vector =
@@ -4712,6 +4891,22 @@ void RegExpConstructResultStub::Generate(MacroAssembler* masm) {
 }
 
 
+void CallFunctionStub::FinishCode(Code* code) {
+  code->set_has_function_cache(false);
+}
+
+
+void CallFunctionStub::Clear(Heap* heap, Address address) {
+  UNREACHABLE();
+}
+
+
+Object* CallFunctionStub::GetCachedValue(Address address) {
+  UNREACHABLE();
+  return NULL;
+}
+
+
 void CallFunctionStub::Generate(MacroAssembler* masm) {
   Label slow, non_function;
 
@@ -4889,23 +5084,26 @@ void StringCharCodeAtGenerator::GenerateFast(MacroAssembler* masm) {
   __ cmp(result_, Operand(ip));
   __ b(ne, &call_runtime_);
   // Get the first of the two strings and load its instance type.
-  __ ldr(object_, FieldMemOperand(object_, ConsString::kFirstOffset));
+  __ ldr(result_, FieldMemOperand(object_, ConsString::kFirstOffset));
   __ jmp(&assure_seq_string);
 
   // SlicedString, unpack and add offset.
   __ bind(&sliced_string);
   __ ldr(result_, FieldMemOperand(object_, SlicedString::kOffsetOffset));
   __ add(scratch_, scratch_, result_);
-  __ ldr(object_, FieldMemOperand(object_, SlicedString::kParentOffset));
+  __ ldr(result_, FieldMemOperand(object_, SlicedString::kParentOffset));
 
   // Assure that we are dealing with a sequential string. Go to runtime if not.
   __ bind(&assure_seq_string);
-  __ ldr(result_, FieldMemOperand(object_, HeapObject::kMapOffset));
+  __ ldr(result_, FieldMemOperand(result_, HeapObject::kMapOffset));
   __ ldrb(result_, FieldMemOperand(result_, Map::kInstanceTypeOffset));
   // Check that parent is not an external string. Go to runtime otherwise.
   STATIC_ASSERT(kSeqStringTag == 0);
   __ tst(result_, Operand(kStringRepresentationMask));
   __ b(ne, &call_runtime_);
+  // Actually fetch the parent string if it is confirmed to be sequential.
+  STATIC_ASSERT(SlicedString::kParentOffset == ConsString::kFirstOffset);
+  __ ldr(object_, FieldMemOperand(object_, SlicedString::kParentOffset));
 
   // Check for 1-byte or 2-byte string.
   __ bind(&flat_string);
@@ -6425,12 +6623,13 @@ void ICCompareStub::GenerateMiss(MacroAssembler* masm) {
   // Call the runtime system in a fresh internal frame.
   ExternalReference miss =
       ExternalReference(IC_Utility(IC::kCompareIC_Miss), masm->isolate());
-  __ EnterInternalFrame();
-  __ Push(r1, r0);
-  __ mov(ip, Operand(Smi::FromInt(op_)));
-  __ push(ip);
-  __ CallExternalReference(miss, 3);
-  __ LeaveInternalFrame();
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
+    __ Push(r1, r0);
+    __ mov(ip, Operand(Smi::FromInt(op_)));
+    __ push(ip);
+    __ CallExternalReference(miss, 3);
+  }
   // Compute the entry point of the rewritten stub.
   __ add(r2, r0, Operand(Code::kHeaderSize - kHeapObjectTag));
   // Restore registers.
@@ -6613,6 +6812,8 @@ void StringDictionaryLookupStub::GeneratePositiveLookup(MacroAssembler* masm,
 
 
 void StringDictionaryLookupStub::Generate(MacroAssembler* masm) {
+  // This stub overrides SometimesSetsUpAFrame() to return false.  That means
+  // we cannot call anything that could cause a GC from this stub.
   // Registers:
   //  result: StringDictionary to probe
   //  r1: key
@@ -6702,6 +6903,267 @@ void StringDictionaryLookupStub::Generate(MacroAssembler* masm) {
 }
 
 
+struct AheadOfTimeWriteBarrierStubList {
+  Register object, value, address;
+  RememberedSetAction action;
+};
+
+
+struct AheadOfTimeWriteBarrierStubList kAheadOfTime[] = {
+  // Used in RegExpExecStub.
+  { r6, r4, r7, EMIT_REMEMBERED_SET },
+  { r6, r2, r7, EMIT_REMEMBERED_SET },
+  // Used in CompileArrayPushCall.
+  // Also used in StoreIC::GenerateNormal via GenerateDictionaryStore.
+  // Also used in KeyedStoreIC::GenerateGeneric.
+  { r3, r4, r5, EMIT_REMEMBERED_SET },
+  // Used in CompileStoreGlobal.
+  { r4, r1, r2, OMIT_REMEMBERED_SET },
+  // Used in StoreStubCompiler::CompileStoreField via GenerateStoreField.
+  { r1, r2, r3, EMIT_REMEMBERED_SET },
+  { r3, r2, r1, EMIT_REMEMBERED_SET },
+  // Used in KeyedStoreStubCompiler::CompileStoreField via GenerateStoreField.
+  { r2, r1, r3, EMIT_REMEMBERED_SET },
+  { r3, r1, r2, EMIT_REMEMBERED_SET },
+  // KeyedStoreStubCompiler::GenerateStoreFastElement.
+  { r4, r2, r3, EMIT_REMEMBERED_SET },
+  // Null termination.
+  { no_reg, no_reg, no_reg, EMIT_REMEMBERED_SET}
+};
+
+
+bool RecordWriteStub::IsPregenerated() {
+  for (AheadOfTimeWriteBarrierStubList* entry = kAheadOfTime;
+       !entry->object.is(no_reg);
+       entry++) {
+    if (object_.is(entry->object) &&
+        value_.is(entry->value) &&
+        address_.is(entry->address) &&
+        remembered_set_action_ == entry->action &&
+        save_fp_regs_mode_ == kDontSaveFPRegs) {
+      return true;
+    }
+  }
+  return false;
+}
+
+
+bool StoreBufferOverflowStub::IsPregenerated() {
+  return save_doubles_ == kDontSaveFPRegs || ISOLATE->fp_stubs_generated();
+}
+
+
+void StoreBufferOverflowStub::GenerateFixedRegStubsAheadOfTime() {
+  StoreBufferOverflowStub stub1(kDontSaveFPRegs);
+  stub1.GetCode()->set_is_pregenerated(true);
+}
+
+
+void RecordWriteStub::GenerateFixedRegStubsAheadOfTime() {
+  for (AheadOfTimeWriteBarrierStubList* entry = kAheadOfTime;
+       !entry->object.is(no_reg);
+       entry++) {
+    RecordWriteStub stub(entry->object,
+                         entry->value,
+                         entry->address,
+                         entry->action,
+                         kDontSaveFPRegs);
+    stub.GetCode()->set_is_pregenerated(true);
+  }
+}
+
+
+// Takes the input in 3 registers: address_ value_ and object_.  A pointer to
+// the value has just been written into the object, now this stub makes sure
+// we keep the GC informed.  The word in the object where the value has been
+// written is in the address register.
+void RecordWriteStub::Generate(MacroAssembler* masm) {
+  Label skip_to_incremental_noncompacting;
+  Label skip_to_incremental_compacting;
+
+  // The first two instructions are generated with labels so as to get the
+  // offset fixed up correctly by the bind(Label*) call.  We patch it back and
+  // forth between a compare instructions (a nop in this position) and the
+  // real branch when we start and stop incremental heap marking.
+  // See RecordWriteStub::Patch for details.
+  __ b(&skip_to_incremental_noncompacting);
+  __ b(&skip_to_incremental_compacting);
+
+  if (remembered_set_action_ == EMIT_REMEMBERED_SET) {
+    __ RememberedSetHelper(object_,
+                           address_,
+                           value_,
+                           save_fp_regs_mode_,
+                           MacroAssembler::kReturnAtEnd);
+  }
+  __ Ret();
+
+  __ bind(&skip_to_incremental_noncompacting);
+  GenerateIncremental(masm, INCREMENTAL);
+
+  __ bind(&skip_to_incremental_compacting);
+  GenerateIncremental(masm, INCREMENTAL_COMPACTION);
+
+  // Initial mode of the stub is expected to be STORE_BUFFER_ONLY.
+  // Will be checked in IncrementalMarking::ActivateGeneratedStub.
+  ASSERT(Assembler::GetBranchOffset(masm->instr_at(0)) < (1 << 12));
+  ASSERT(Assembler::GetBranchOffset(masm->instr_at(4)) < (1 << 12));
+  PatchBranchIntoNop(masm, 0);
+  PatchBranchIntoNop(masm, Assembler::kInstrSize);
+}
+
+
+void RecordWriteStub::GenerateIncremental(MacroAssembler* masm, Mode mode) {
+  regs_.Save(masm);
+
+  if (remembered_set_action_ == EMIT_REMEMBERED_SET) {
+    Label dont_need_remembered_set;
+
+    __ ldr(regs_.scratch0(), MemOperand(regs_.address(), 0));
+    __ JumpIfNotInNewSpace(regs_.scratch0(),  // Value.
+                           regs_.scratch0(),
+                           &dont_need_remembered_set);
+
+    __ CheckPageFlag(regs_.object(),
+                     regs_.scratch0(),
+                     1 << MemoryChunk::SCAN_ON_SCAVENGE,
+                     ne,
+                     &dont_need_remembered_set);
+
+    // First notify the incremental marker if necessary, then update the
+    // remembered set.
+    CheckNeedsToInformIncrementalMarker(
+        masm, kUpdateRememberedSetOnNoNeedToInformIncrementalMarker, mode);
+    InformIncrementalMarker(masm, mode);
+    regs_.Restore(masm);
+    __ RememberedSetHelper(object_,
+                           address_,
+                           value_,
+                           save_fp_regs_mode_,
+                           MacroAssembler::kReturnAtEnd);
+
+    __ bind(&dont_need_remembered_set);
+  }
+
+  CheckNeedsToInformIncrementalMarker(
+      masm, kReturnOnNoNeedToInformIncrementalMarker, mode);
+  InformIncrementalMarker(masm, mode);
+  regs_.Restore(masm);
+  __ Ret();
+}
+
+
+void RecordWriteStub::InformIncrementalMarker(MacroAssembler* masm, Mode mode) {
+  regs_.SaveCallerSaveRegisters(masm, save_fp_regs_mode_);
+  int argument_count = 3;
+  __ PrepareCallCFunction(argument_count, regs_.scratch0());
+  Register address =
+      r0.is(regs_.address()) ? regs_.scratch0() : regs_.address();
+  ASSERT(!address.is(regs_.object()));
+  ASSERT(!address.is(r0));
+  __ Move(address, regs_.address());
+  __ Move(r0, regs_.object());
+  if (mode == INCREMENTAL_COMPACTION) {
+    __ Move(r1, address);
+  } else {
+    ASSERT(mode == INCREMENTAL);
+    __ ldr(r1, MemOperand(address, 0));
+  }
+  __ mov(r2, Operand(ExternalReference::isolate_address()));
+
+  AllowExternalCallThatCantCauseGC scope(masm);
+  if (mode == INCREMENTAL_COMPACTION) {
+    __ CallCFunction(
+        ExternalReference::incremental_evacuation_record_write_function(
+            masm->isolate()),
+        argument_count);
+  } else {
+    ASSERT(mode == INCREMENTAL);
+    __ CallCFunction(
+        ExternalReference::incremental_marking_record_write_function(
+            masm->isolate()),
+        argument_count);
+  }
+  regs_.RestoreCallerSaveRegisters(masm, save_fp_regs_mode_);
+}
+
+
+void RecordWriteStub::CheckNeedsToInformIncrementalMarker(
+    MacroAssembler* masm,
+    OnNoNeedToInformIncrementalMarker on_no_need,
+    Mode mode) {
+  Label on_black;
+  Label need_incremental;
+  Label need_incremental_pop_scratch;
+
+  // Let's look at the color of the object:  If it is not black we don't have
+  // to inform the incremental marker.
+  __ JumpIfBlack(regs_.object(), regs_.scratch0(), regs_.scratch1(), &on_black);
+
+  regs_.Restore(masm);
+  if (on_no_need == kUpdateRememberedSetOnNoNeedToInformIncrementalMarker) {
+    __ RememberedSetHelper(object_,
+                           address_,
+                           value_,
+                           save_fp_regs_mode_,
+                           MacroAssembler::kReturnAtEnd);
+  } else {
+    __ Ret();
+  }
+
+  __ bind(&on_black);
+
+  // Get the value from the slot.
+  __ ldr(regs_.scratch0(), MemOperand(regs_.address(), 0));
+
+  if (mode == INCREMENTAL_COMPACTION) {
+    Label ensure_not_white;
+
+    __ CheckPageFlag(regs_.scratch0(),  // Contains value.
+                     regs_.scratch1(),  // Scratch.
+                     MemoryChunk::kEvacuationCandidateMask,
+                     eq,
+                     &ensure_not_white);
+
+    __ CheckPageFlag(regs_.object(),
+                     regs_.scratch1(),  // Scratch.
+                     MemoryChunk::kSkipEvacuationSlotsRecordingMask,
+                     eq,
+                     &need_incremental);
+
+    __ bind(&ensure_not_white);
+  }
+
+  // We need extra registers for this, so we push the object and the address
+  // register temporarily.
+  __ Push(regs_.object(), regs_.address());
+  __ EnsureNotWhite(regs_.scratch0(),  // The value.
+                    regs_.scratch1(),  // Scratch.
+                    regs_.object(),  // Scratch.
+                    regs_.address(),  // Scratch.
+                    &need_incremental_pop_scratch);
+  __ Pop(regs_.object(), regs_.address());
+
+  regs_.Restore(masm);
+  if (on_no_need == kUpdateRememberedSetOnNoNeedToInformIncrementalMarker) {
+    __ RememberedSetHelper(object_,
+                           address_,
+                           value_,
+                           save_fp_regs_mode_,
+                           MacroAssembler::kReturnAtEnd);
+  } else {
+    __ Ret();
+  }
+
+  __ bind(&need_incremental_pop_scratch);
+  __ Pop(regs_.object(), regs_.address());
+
+  __ bind(&need_incremental);
+
+  // Fall through when we need to inform the incremental marker.
+}
+
+
 #undef __
 
 } }  // namespace v8::internal
diff --git a/deps/v8/src/arm/code-stubs-arm.h b/deps/v8/src/arm/code-stubs-arm.h
index 557f7e6d4..3ba75bab1 100644
--- a/deps/v8/src/arm/code-stubs-arm.h
+++ b/deps/v8/src/arm/code-stubs-arm.h
@@ -58,6 +58,25 @@ class TranscendentalCacheStub: public CodeStub {
 };
 
 
+class StoreBufferOverflowStub: public CodeStub {
+ public:
+  explicit StoreBufferOverflowStub(SaveFPRegsMode save_fp)
+      : save_doubles_(save_fp) { }
+
+  void Generate(MacroAssembler* masm);
+
+  virtual bool IsPregenerated();
+  static void GenerateFixedRegStubsAheadOfTime();
+  virtual bool SometimesSetsUpAFrame() { return false; }
+
+ private:
+  SaveFPRegsMode save_doubles_;
+
+  Major MajorKey() { return StoreBufferOverflow; }
+  int MinorKey() { return (save_doubles_ == kSaveFPRegs) ? 1 : 0; }
+};
+
+
 class UnaryOpStub: public CodeStub {
  public:
   UnaryOpStub(Token::Value op,
@@ -323,6 +342,9 @@ class WriteInt32ToHeapNumberStub : public CodeStub {
         the_heap_number_(the_heap_number),
         scratch_(scratch) { }
 
+  bool IsPregenerated();
+  static void GenerateFixedRegStubsAheadOfTime();
+
  private:
   Register the_int_;
   Register the_heap_number_;
@@ -371,6 +393,225 @@ class NumberToStringStub: public CodeStub {
 };
 
 
+class RecordWriteStub: public CodeStub {
+ public:
+  RecordWriteStub(Register object,
+                  Register value,
+                  Register address,
+                  RememberedSetAction remembered_set_action,
+                  SaveFPRegsMode fp_mode)
+      : object_(object),
+        value_(value),
+        address_(address),
+        remembered_set_action_(remembered_set_action),
+        save_fp_regs_mode_(fp_mode),
+        regs_(object,   // An input reg.
+              address,  // An input reg.
+              value) {  // One scratch reg.
+  }
+
+  enum Mode {
+    STORE_BUFFER_ONLY,
+    INCREMENTAL,
+    INCREMENTAL_COMPACTION
+  };
+
+  virtual bool IsPregenerated();
+  static void GenerateFixedRegStubsAheadOfTime();
+  virtual bool SometimesSetsUpAFrame() { return false; }
+
+  static void PatchBranchIntoNop(MacroAssembler* masm, int pos) {
+    masm->instr_at_put(pos, (masm->instr_at(pos) & ~B27) | (B24 | B20));
+    ASSERT(Assembler::IsTstImmediate(masm->instr_at(pos)));
+  }
+
+  static void PatchNopIntoBranch(MacroAssembler* masm, int pos) {
+    masm->instr_at_put(pos, (masm->instr_at(pos) & ~(B24 | B20)) | B27);
+    ASSERT(Assembler::IsBranch(masm->instr_at(pos)));
+  }
+
+  static Mode GetMode(Code* stub) {
+    Instr first_instruction = Assembler::instr_at(stub->instruction_start());
+    Instr second_instruction = Assembler::instr_at(stub->instruction_start() +
+                                                   Assembler::kInstrSize);
+
+    if (Assembler::IsBranch(first_instruction)) {
+      return INCREMENTAL;
+    }
+
+    ASSERT(Assembler::IsTstImmediate(first_instruction));
+
+    if (Assembler::IsBranch(second_instruction)) {
+      return INCREMENTAL_COMPACTION;
+    }
+
+    ASSERT(Assembler::IsTstImmediate(second_instruction));
+
+    return STORE_BUFFER_ONLY;
+  }
+
+  static void Patch(Code* stub, Mode mode) {
+    MacroAssembler masm(NULL,
+                        stub->instruction_start(),
+                        stub->instruction_size());
+    switch (mode) {
+      case STORE_BUFFER_ONLY:
+        ASSERT(GetMode(stub) == INCREMENTAL ||
+               GetMode(stub) == INCREMENTAL_COMPACTION);
+        PatchBranchIntoNop(&masm, 0);
+        PatchBranchIntoNop(&masm, Assembler::kInstrSize);
+        break;
+      case INCREMENTAL:
+        ASSERT(GetMode(stub) == STORE_BUFFER_ONLY);
+        PatchNopIntoBranch(&masm, 0);
+        break;
+      case INCREMENTAL_COMPACTION:
+        ASSERT(GetMode(stub) == STORE_BUFFER_ONLY);
+        PatchNopIntoBranch(&masm, Assembler::kInstrSize);
+        break;
+    }
+    ASSERT(GetMode(stub) == mode);
+    CPU::FlushICache(stub->instruction_start(), 2 * Assembler::kInstrSize);
+  }
+
+ private:
+  // This is a helper class for freeing up 3 scratch registers.  The input is
+  // two registers that must be preserved and one scratch register provided by
+  // the caller.
+  class RegisterAllocation {
+   public:
+    RegisterAllocation(Register object,
+                       Register address,
+                       Register scratch0)
+        : object_(object),
+          address_(address),
+          scratch0_(scratch0) {
+      ASSERT(!AreAliased(scratch0, object, address, no_reg));
+      scratch1_ = GetRegThatIsNotOneOf(object_, address_, scratch0_);
+    }
+
+    void Save(MacroAssembler* masm) {
+      ASSERT(!AreAliased(object_, address_, scratch1_, scratch0_));
+      // We don't have to save scratch0_ because it was given to us as
+      // a scratch register.
+      masm->push(scratch1_);
+    }
+
+    void Restore(MacroAssembler* masm) {
+      masm->pop(scratch1_);
+    }
+
+    // If we have to call into C then we need to save and restore all caller-
+    // saved registers that were not already preserved.  The scratch registers
+    // will be restored by other means so we don't bother pushing them here.
+    void SaveCallerSaveRegisters(MacroAssembler* masm, SaveFPRegsMode mode) {
+      masm->stm(db_w, sp, (kCallerSaved | lr.bit()) & ~scratch1_.bit());
+      if (mode == kSaveFPRegs) {
+        CpuFeatures::Scope scope(VFP3);
+        masm->sub(sp,
+                  sp,
+                  Operand(kDoubleSize * (DwVfpRegister::kNumRegisters - 1)));
+        // Save all VFP registers except d0.
+        for (int i = DwVfpRegister::kNumRegisters - 1; i > 0; i--) {
+          DwVfpRegister reg = DwVfpRegister::from_code(i);
+          masm->vstr(reg, MemOperand(sp, (i - 1) * kDoubleSize));
+        }
+      }
+    }
+
+    inline void RestoreCallerSaveRegisters(MacroAssembler*masm,
+                                           SaveFPRegsMode mode) {
+      if (mode == kSaveFPRegs) {
+        CpuFeatures::Scope scope(VFP3);
+        // Restore all VFP registers except d0.
+        for (int i = DwVfpRegister::kNumRegisters - 1; i > 0; i--) {
+          DwVfpRegister reg = DwVfpRegister::from_code(i);
+          masm->vldr(reg, MemOperand(sp, (i - 1) * kDoubleSize));
+        }
+        masm->add(sp,
+                  sp,
+                  Operand(kDoubleSize * (DwVfpRegister::kNumRegisters - 1)));
+      }
+      masm->ldm(ia_w, sp, (kCallerSaved | lr.bit()) & ~scratch1_.bit());
+    }
+
+    inline Register object() { return object_; }
+    inline Register address() { return address_; }
+    inline Register scratch0() { return scratch0_; }
+    inline Register scratch1() { return scratch1_; }
+
+   private:
+    Register object_;
+    Register address_;
+    Register scratch0_;
+    Register scratch1_;
+
+    Register GetRegThatIsNotOneOf(Register r1,
+                                  Register r2,
+                                  Register r3) {
+      for (int i = 0; i < Register::kNumAllocatableRegisters; i++) {
+        Register candidate = Register::FromAllocationIndex(i);
+        if (candidate.is(r1)) continue;
+        if (candidate.is(r2)) continue;
+        if (candidate.is(r3)) continue;
+        return candidate;
+      }
+      UNREACHABLE();
+      return no_reg;
+    }
+    friend class RecordWriteStub;
+  };
+
+  enum OnNoNeedToInformIncrementalMarker {
+    kReturnOnNoNeedToInformIncrementalMarker,
+    kUpdateRememberedSetOnNoNeedToInformIncrementalMarker
+  };
+
+  void Generate(MacroAssembler* masm);
+  void GenerateIncremental(MacroAssembler* masm, Mode mode);
+  void CheckNeedsToInformIncrementalMarker(
+      MacroAssembler* masm,
+      OnNoNeedToInformIncrementalMarker on_no_need,
+      Mode mode);
+  void InformIncrementalMarker(MacroAssembler* masm, Mode mode);
+
+  Major MajorKey() { return RecordWrite; }
+
+  int MinorKey() {
+    return ObjectBits::encode(object_.code()) |
+        ValueBits::encode(value_.code()) |
+        AddressBits::encode(address_.code()) |
+        RememberedSetActionBits::encode(remembered_set_action_) |
+        SaveFPRegsModeBits::encode(save_fp_regs_mode_);
+  }
+
+  bool MustBeInStubCache() {
+    // All stubs must be registered in the stub cache
+    // otherwise IncrementalMarker would not be able to find
+    // and patch it.
+    return true;
+  }
+
+  void Activate(Code* code) {
+    code->GetHeap()->incremental_marking()->ActivateGeneratedStub(code);
+  }
+
+  class ObjectBits: public BitField<int, 0, 4> {};
+  class ValueBits: public BitField<int, 4, 4> {};
+  class AddressBits: public BitField<int, 8, 4> {};
+  class RememberedSetActionBits: public BitField<RememberedSetAction, 12, 1> {};
+  class SaveFPRegsModeBits: public BitField<SaveFPRegsMode, 13, 1> {};
+
+  Register object_;
+  Register value_;
+  Register address_;
+  RememberedSetAction remembered_set_action_;
+  SaveFPRegsMode save_fp_regs_mode_;
+  Label slow_;
+  RegisterAllocation regs_;
+};
+
+
 // Enter C code from generated RegExp code in a way that allows
 // the C code to fix the return address in case of a GC.
 // Currently only needed on ARM.
@@ -575,6 +816,8 @@ class StringDictionaryLookupStub: public CodeStub {
                                      Register r0,
                                      Register r1);
 
+  virtual bool SometimesSetsUpAFrame() { return false; }
+
  private:
   static const int kInlinedProbes = 4;
   static const int kTotalProbes = 20;
@@ -587,7 +830,7 @@ class StringDictionaryLookupStub: public CodeStub {
       StringDictionary::kHeaderSize +
       StringDictionary::kElementsStartIndex * kPointerSize;
 
-  Major MajorKey() { return StringDictionaryNegativeLookup; }
+  Major MajorKey() { return StringDictionaryLookup; }
 
   int MinorKey() {
     return LookupModeBits::encode(mode_);
diff --git a/deps/v8/src/arm/codegen-arm.cc b/deps/v8/src/arm/codegen-arm.cc
index bf748a9b6..3993ed02b 100644
--- a/deps/v8/src/arm/codegen-arm.cc
+++ b/deps/v8/src/arm/codegen-arm.cc
@@ -38,12 +38,16 @@ namespace internal {
 // Platform-specific RuntimeCallHelper functions.
 
 void StubRuntimeCallHelper::BeforeCall(MacroAssembler* masm) const {
-  masm->EnterInternalFrame();
+  masm->EnterFrame(StackFrame::INTERNAL);
+  ASSERT(!masm->has_frame());
+  masm->set_has_frame(true);
 }
 
 
 void StubRuntimeCallHelper::AfterCall(MacroAssembler* masm) const {
-  masm->LeaveInternalFrame();
+  masm->LeaveFrame(StackFrame::INTERNAL);
+  ASSERT(masm->has_frame());
+  masm->set_has_frame(false);
 }
 
 
diff --git a/deps/v8/src/arm/codegen-arm.h b/deps/v8/src/arm/codegen-arm.h
index d27982aba..1c0d508d2 100644
--- a/deps/v8/src/arm/codegen-arm.h
+++ b/deps/v8/src/arm/codegen-arm.h
@@ -69,16 +69,6 @@ class CodeGenerator: public AstVisitor {
                               int pos,
                               bool right_here = false);
 
-  // Constants related to patching of inlined load/store.
-  static int GetInlinedKeyedLoadInstructionsAfterPatch() {
-    return FLAG_debug_code ? 32 : 13;
-  }
-  static const int kInlinedKeyedStoreInstructionsAfterPatch = 8;
-  static int GetInlinedNamedStoreInstructionsAfterPatch() {
-    ASSERT(Isolate::Current()->inlined_write_barrier_size() != -1);
-    return Isolate::Current()->inlined_write_barrier_size() + 4;
-  }
-
  private:
   DISALLOW_COPY_AND_ASSIGN(CodeGenerator);
 };
diff --git a/deps/v8/src/arm/debug-arm.cc b/deps/v8/src/arm/debug-arm.cc
index 07a22722c..b866f9cc8 100644
--- a/deps/v8/src/arm/debug-arm.cc
+++ b/deps/v8/src/arm/debug-arm.cc
@@ -132,55 +132,57 @@ void BreakLocationIterator::ClearDebugBreakAtSlot() {
 static void Generate_DebugBreakCallHelper(MacroAssembler* masm,
                                           RegList object_regs,
                                           RegList non_object_regs) {
-  __ EnterInternalFrame();
-
-  // Store the registers containing live values on the expression stack to
-  // make sure that these are correctly updated during GC. Non object values
-  // are stored as a smi causing it to be untouched by GC.
-  ASSERT((object_regs & ~kJSCallerSaved) == 0);
-  ASSERT((non_object_regs & ~kJSCallerSaved) == 0);
-  ASSERT((object_regs & non_object_regs) == 0);
-  if ((object_regs | non_object_regs) != 0) {
-    for (int i = 0; i < kNumJSCallerSaved; i++) {
-      int r = JSCallerSavedCode(i);
-      Register reg = { r };
-      if ((non_object_regs & (1 << r)) != 0) {
-        if (FLAG_debug_code) {
-          __ tst(reg, Operand(0xc0000000));
-          __ Assert(eq, "Unable to encode value as smi");
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
+
+    // Store the registers containing live values on the expression stack to
+    // make sure that these are correctly updated during GC. Non object values
+    // are stored as a smi causing it to be untouched by GC.
+    ASSERT((object_regs & ~kJSCallerSaved) == 0);
+    ASSERT((non_object_regs & ~kJSCallerSaved) == 0);
+    ASSERT((object_regs & non_object_regs) == 0);
+    if ((object_regs | non_object_regs) != 0) {
+      for (int i = 0; i < kNumJSCallerSaved; i++) {
+        int r = JSCallerSavedCode(i);
+        Register reg = { r };
+        if ((non_object_regs & (1 << r)) != 0) {
+          if (FLAG_debug_code) {
+            __ tst(reg, Operand(0xc0000000));
+            __ Assert(eq, "Unable to encode value as smi");
+          }
+          __ mov(reg, Operand(reg, LSL, kSmiTagSize));
         }
-        __ mov(reg, Operand(reg, LSL, kSmiTagSize));
       }
+      __ stm(db_w, sp, object_regs | non_object_regs);
     }
-    __ stm(db_w, sp, object_regs | non_object_regs);
-  }
 
 #ifdef DEBUG
-  __ RecordComment("// Calling from debug break to runtime - come in - over");
+    __ RecordComment("// Calling from debug break to runtime - come in - over");
 #endif
-  __ mov(r0, Operand(0, RelocInfo::NONE));  // no arguments
-  __ mov(r1, Operand(ExternalReference::debug_break(masm->isolate())));
-
-  CEntryStub ceb(1);
-  __ CallStub(&ceb);
-
-  // Restore the register values from the expression stack.
-  if ((object_regs | non_object_regs) != 0) {
-    __ ldm(ia_w, sp, object_regs | non_object_regs);
-    for (int i = 0; i < kNumJSCallerSaved; i++) {
-      int r = JSCallerSavedCode(i);
-      Register reg = { r };
-      if ((non_object_regs & (1 << r)) != 0) {
-        __ mov(reg, Operand(reg, LSR, kSmiTagSize));
-      }
-      if (FLAG_debug_code &&
-          (((object_regs |non_object_regs) & (1 << r)) == 0)) {
-        __ mov(reg, Operand(kDebugZapValue));
+    __ mov(r0, Operand(0, RelocInfo::NONE));  // no arguments
+    __ mov(r1, Operand(ExternalReference::debug_break(masm->isolate())));
+
+    CEntryStub ceb(1);
+    __ CallStub(&ceb);
+
+    // Restore the register values from the expression stack.
+    if ((object_regs | non_object_regs) != 0) {
+      __ ldm(ia_w, sp, object_regs | non_object_regs);
+      for (int i = 0; i < kNumJSCallerSaved; i++) {
+        int r = JSCallerSavedCode(i);
+        Register reg = { r };
+        if ((non_object_regs & (1 << r)) != 0) {
+          __ mov(reg, Operand(reg, LSR, kSmiTagSize));
+        }
+        if (FLAG_debug_code &&
+            (((object_regs |non_object_regs) & (1 << r)) == 0)) {
+          __ mov(reg, Operand(kDebugZapValue));
+        }
       }
     }
-  }
 
-  __ LeaveInternalFrame();
+    // Leave the internal frame.
+  }
 
   // Now that the break point has been handled, resume normal execution by
   // jumping to the target address intended by the caller and that was
diff --git a/deps/v8/src/arm/deoptimizer-arm.cc b/deps/v8/src/arm/deoptimizer-arm.cc
index 00357f76d..bb03d740d 100644
--- a/deps/v8/src/arm/deoptimizer-arm.cc
+++ b/deps/v8/src/arm/deoptimizer-arm.cc
@@ -112,12 +112,19 @@ void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
   }
 #endif
 
+  Isolate* isolate = code->GetIsolate();
+
   // Add the deoptimizing code to the list.
   DeoptimizingCodeListNode* node = new DeoptimizingCodeListNode(code);
-  DeoptimizerData* data = code->GetIsolate()->deoptimizer_data();
+  DeoptimizerData* data = isolate->deoptimizer_data();
   node->set_next(data->deoptimizing_code_list_);
   data->deoptimizing_code_list_ = node;
 
+  // We might be in the middle of incremental marking with compaction.
+  // Tell collector to treat this code object in a special way and
+  // ignore all slots that might have been recorded on it.
+  isolate->heap()->mark_compact_collector()->InvalidateCode(code);
+
   // Set the code for the function to non-optimized version.
   function->ReplaceCode(function->shared()->code());
 
@@ -134,7 +141,8 @@ void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
 }
 
 
-void Deoptimizer::PatchStackCheckCodeAt(Address pc_after,
+void Deoptimizer::PatchStackCheckCodeAt(Code* unoptimized_code,
+                                        Address pc_after,
                                         Code* check_code,
                                         Code* replacement_code) {
   const int kInstrSize = Assembler::kInstrSize;
@@ -169,6 +177,13 @@ void Deoptimizer::PatchStackCheckCodeAt(Address pc_after,
          reinterpret_cast<uint32_t>(check_code->entry()));
   Memory::uint32_at(stack_check_address_pointer) =
       reinterpret_cast<uint32_t>(replacement_code->entry());
+
+  RelocInfo rinfo(pc_after - 2 * kInstrSize,
+                  RelocInfo::CODE_TARGET,
+                  0,
+                  unoptimized_code);
+  unoptimized_code->GetHeap()->incremental_marking()->RecordWriteIntoCode(
+      unoptimized_code, &rinfo, replacement_code);
 }
 
 
@@ -193,6 +208,9 @@ void Deoptimizer::RevertStackCheckCodeAt(Address pc_after,
          reinterpret_cast<uint32_t>(replacement_code->entry()));
   Memory::uint32_at(stack_check_address_pointer) =
       reinterpret_cast<uint32_t>(check_code->entry());
+
+  check_code->GetHeap()->incremental_marking()->
+      RecordCodeTargetPatch(pc_after - 2 * kInstrSize, check_code);
 }
 
 
@@ -632,7 +650,10 @@ void Deoptimizer::EntryGenerator::Generate() {
   __ mov(r5, Operand(ExternalReference::isolate_address()));
   __ str(r5, MemOperand(sp, 1 * kPointerSize));  // Isolate.
   // Call Deoptimizer::New().
-  __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate), 6);
+  {
+    AllowExternalCallThatCantCauseGC scope(masm());
+    __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate), 6);
+  }
 
   // Preserve "deoptimizer" object in register r0 and get the input
   // frame descriptor pointer to r1 (deoptimizer->input_);
@@ -686,8 +707,11 @@ void Deoptimizer::EntryGenerator::Generate() {
   // r0: deoptimizer object; r1: scratch.
   __ PrepareCallCFunction(1, r1);
   // Call Deoptimizer::ComputeOutputFrames().
-  __ CallCFunction(
-      ExternalReference::compute_output_frames_function(isolate), 1);
+  {
+    AllowExternalCallThatCantCauseGC scope(masm());
+    __ CallCFunction(
+        ExternalReference::compute_output_frames_function(isolate), 1);
+  }
   __ pop(r0);  // Restore deoptimizer object (class Deoptimizer).
 
   // Replace the current (input) frame with the output frames.
diff --git a/deps/v8/src/arm/frames-arm.h b/deps/v8/src/arm/frames-arm.h
index 26bbd82d0..c66ceee93 100644
--- a/deps/v8/src/arm/frames-arm.h
+++ b/deps/v8/src/arm/frames-arm.h
@@ -70,6 +70,16 @@ static const RegList kCalleeSaved =
   1 << 10 |  // r10 v7
   1 << 11;   // r11 v8 (fp in JavaScript code)
 
+// When calling into C++ (only for C++ calls that can't cause a GC).
+// The call code will take care of lr, fp, etc.
+static const RegList kCallerSaved =
+  1 <<  0 |  // r0
+  1 <<  1 |  // r1
+  1 <<  2 |  // r2
+  1 <<  3 |  // r3
+  1 <<  9;   // r9
+
+
 static const int kNumCalleeSaved = 7 + kR9Available;
 
 // Double registers d8 to d15 are callee-saved.
diff --git a/deps/v8/src/arm/full-codegen-arm.cc b/deps/v8/src/arm/full-codegen-arm.cc
index 50ed8b1da..353ce5b10 100644
--- a/deps/v8/src/arm/full-codegen-arm.cc
+++ b/deps/v8/src/arm/full-codegen-arm.cc
@@ -39,6 +39,7 @@
 #include "stub-cache.h"
 
 #include "arm/code-stubs-arm.h"
+#include "arm/macro-assembler-arm.h"
 
 namespace v8 {
 namespace internal {
@@ -155,6 +156,11 @@ void FullCodeGenerator::Generate(CompilationInfo* info) {
     __ bind(&ok);
   }
 
+  // Open a frame scope to indicate that there is a frame on the stack.  The
+  // MANUAL indicates that the scope shouldn't actually generate code to set up
+  // the frame (that is done below).
+  FrameScope frame_scope(masm_, StackFrame::MANUAL);
+
   int locals_count = info->scope()->num_stack_slots();
 
   __ Push(lr, fp, cp, r1);
@@ -200,13 +206,12 @@ void FullCodeGenerator::Generate(CompilationInfo* info) {
         // Load parameter from stack.
         __ ldr(r0, MemOperand(fp, parameter_offset));
         // Store it in the context.
-        __ mov(r1, Operand(Context::SlotOffset(var->index())));
-        __ str(r0, MemOperand(cp, r1));
-        // Update the write barrier. This clobbers all involved
-        // registers, so we have to use two more registers to avoid
-        // clobbering cp.
-        __ mov(r2, Operand(cp));
-        __ RecordWrite(r2, Operand(r1), r3, r0);
+        MemOperand target = ContextOperand(cp, var->index());
+        __ str(r0, target);
+
+        // Update the write barrier.
+        __ RecordWriteContextSlot(
+            cp, target.offset(), r0, r3, kLRHasBeenSaved, kDontSaveFPRegs);
       }
     }
   }
@@ -264,7 +269,7 @@ void FullCodeGenerator::Generate(CompilationInfo* info) {
       // constant.
       if (scope()->is_function_scope() && scope()->function() != NULL) {
         int ignored = 0;
-        EmitDeclaration(scope()->function(), Variable::CONST, NULL, &ignored);
+        EmitDeclaration(scope()->function(), CONST, NULL, &ignored);
       }
       VisitDeclarations(scope()->declarations());
     }
@@ -665,12 +670,15 @@ void FullCodeGenerator::SetVar(Variable* var,
   ASSERT(!scratch1.is(src));
   MemOperand location = VarOperand(var, scratch0);
   __ str(src, location);
+
   // Emit the write barrier code if the location is in the heap.
   if (var->IsContextSlot()) {
-    __ RecordWrite(scratch0,
-                   Operand(Context::SlotOffset(var->index())),
-                   scratch1,
-                   src);
+    __ RecordWriteContextSlot(scratch0,
+                              location.offset(),
+                              src,
+                              scratch1,
+                              kLRHasBeenSaved,
+                              kDontSaveFPRegs);
   }
 }
 
@@ -703,7 +711,7 @@ void FullCodeGenerator::PrepareForBailoutBeforeSplit(State state,
 
 
 void FullCodeGenerator::EmitDeclaration(VariableProxy* proxy,
-                                        Variable::Mode mode,
+                                        VariableMode mode,
                                         FunctionLiteral* function,
                                         int* global_count) {
   // If it was not possible to allocate the variable at compile time, we
@@ -721,7 +729,7 @@ void FullCodeGenerator::EmitDeclaration(VariableProxy* proxy,
         Comment cmnt(masm_, "[ Declaration");
         VisitForAccumulatorValue(function);
         __ str(result_register(), StackOperand(variable));
-      } else if (mode == Variable::CONST || mode == Variable::LET) {
+      } else if (mode == CONST || mode == LET) {
         Comment cmnt(masm_, "[ Declaration");
         __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
         __ str(ip, StackOperand(variable));
@@ -746,10 +754,16 @@ void FullCodeGenerator::EmitDeclaration(VariableProxy* proxy,
         __ str(result_register(), ContextOperand(cp, variable->index()));
         int offset = Context::SlotOffset(variable->index());
         // We know that we have written a function, which is not a smi.
-        __ mov(r1, Operand(cp));
-        __ RecordWrite(r1, Operand(offset), r2, result_register());
+        __ RecordWriteContextSlot(cp,
+                                  offset,
+                                  result_register(),
+                                  r2,
+                                  kLRHasBeenSaved,
+                                  kDontSaveFPRegs,
+                                  EMIT_REMEMBERED_SET,
+                                  OMIT_SMI_CHECK);
         PrepareForBailoutForId(proxy->id(), NO_REGISTERS);
-      } else if (mode == Variable::CONST || mode == Variable::LET) {
+      } else if (mode == CONST || mode == LET) {
         Comment cmnt(masm_, "[ Declaration");
         __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
         __ str(ip, ContextOperand(cp, variable->index()));
@@ -762,10 +776,8 @@ void FullCodeGenerator::EmitDeclaration(VariableProxy* proxy,
       Comment cmnt(masm_, "[ Declaration");
       __ mov(r2, Operand(variable->name()));
       // Declaration nodes are always introduced in one of three modes.
-      ASSERT(mode == Variable::VAR ||
-             mode == Variable::CONST ||
-             mode == Variable::LET);
-      PropertyAttributes attr = (mode == Variable::CONST) ? READ_ONLY : NONE;
+      ASSERT(mode == VAR || mode == CONST || mode == LET);
+      PropertyAttributes attr = (mode == CONST) ? READ_ONLY : NONE;
       __ mov(r1, Operand(Smi::FromInt(attr)));
       // Push initial value, if any.
       // Note: For variables we must not push an initial value (such as
@@ -775,7 +787,7 @@ void FullCodeGenerator::EmitDeclaration(VariableProxy* proxy,
         __ Push(cp, r2, r1);
         // Push initial value for function declaration.
         VisitForStackValue(function);
-      } else if (mode == Variable::CONST || mode == Variable::LET) {
+      } else if (mode == CONST || mode == LET) {
         __ LoadRoot(r0, Heap::kTheHoleValueRootIndex);
         __ Push(cp, r2, r1, r0);
       } else {
@@ -1205,15 +1217,23 @@ void FullCodeGenerator::EmitDynamicLookupFastCase(Variable* var,
   // introducing variables.  In those cases, we do not want to
   // perform a runtime call for all variables in the scope
   // containing the eval.
-  if (var->mode() == Variable::DYNAMIC_GLOBAL) {
+  if (var->mode() == DYNAMIC_GLOBAL) {
     EmitLoadGlobalCheckExtensions(var, typeof_state, slow);
     __ jmp(done);
-  } else if (var->mode() == Variable::DYNAMIC_LOCAL) {
+  } else if (var->mode() == DYNAMIC_LOCAL) {
     Variable* local = var->local_if_not_shadowed();
     __ ldr(r0, ContextSlotOperandCheckExtensions(local, slow));
-    if (local->mode() == Variable::CONST) {
+    if (local->mode() == CONST ||
+        local->mode() == LET) {
       __ CompareRoot(r0, Heap::kTheHoleValueRootIndex);
-      __ LoadRoot(r0, Heap::kUndefinedValueRootIndex, eq);
+      if (local->mode() == CONST) {
+        __ LoadRoot(r0, Heap::kUndefinedValueRootIndex, eq);
+      } else {  // LET
+        __ b(ne, done);
+        __ mov(r0, Operand(var->name()));
+        __ push(r0);
+        __ CallRuntime(Runtime::kThrowReferenceError, 1);
+      }
     }
     __ jmp(done);
   }
@@ -1246,13 +1266,13 @@ void FullCodeGenerator::EmitVariableLoad(VariableProxy* proxy) {
       Comment cmnt(masm_, var->IsContextSlot()
                               ? "Context variable"
                               : "Stack variable");
-      if (var->mode() != Variable::LET && var->mode() != Variable::CONST) {
+      if (var->mode() != LET && var->mode() != CONST) {
         context()->Plug(var);
       } else {
         // Let and const need a read barrier.
         GetVar(r0, var);
         __ CompareRoot(r0, Heap::kTheHoleValueRootIndex);
-        if (var->mode() == Variable::LET) {
+        if (var->mode() == LET) {
           Label done;
           __ b(ne, &done);
           __ mov(r0, Operand(var->name()));
@@ -1490,14 +1510,23 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
     VisitForAccumulatorValue(subexpr);
 
     // Store the subexpression value in the array's elements.
-    __ ldr(r1, MemOperand(sp));  // Copy of array literal.
-    __ ldr(r1, FieldMemOperand(r1, JSObject::kElementsOffset));
+    __ ldr(r6, MemOperand(sp));  // Copy of array literal.
+    __ ldr(r1, FieldMemOperand(r6, JSObject::kElementsOffset));
     int offset = FixedArray::kHeaderSize + (i * kPointerSize);
     __ str(result_register(), FieldMemOperand(r1, offset));
 
+    Label no_map_change;
+    __ JumpIfSmi(result_register(), &no_map_change);
     // Update the write barrier for the array store with r0 as the scratch
     // register.
-    __ RecordWrite(r1, Operand(offset), r2, result_register());
+    __ RecordWriteField(
+        r1, offset, result_register(), r2, kLRHasBeenSaved, kDontSaveFPRegs,
+        EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
+    __ ldr(r3, FieldMemOperand(r1, HeapObject::kMapOffset));
+    __ CheckFastSmiOnlyElements(r3, r2, &no_map_change);
+    __ push(r6);  // Copy of array literal.
+    __ CallRuntime(Runtime::kNonSmiElementStored, 1);
+    __ bind(&no_map_change);
 
     PrepareForBailoutForId(expr->GetIdForElement(i), NO_REGISTERS);
   }
@@ -1844,7 +1873,7 @@ void FullCodeGenerator::EmitVariableAssignment(Variable* var,
       __ CallRuntime(Runtime::kInitializeConstContextSlot, 3);
     }
 
-  } else if (var->mode() == Variable::LET && op != Token::INIT_LET) {
+  } else if (var->mode() == LET && op != Token::INIT_LET) {
     // Non-initializing assignment to let variable needs a write barrier.
     if (var->IsLookupSlot()) {
       __ push(r0);  // Value.
@@ -1869,11 +1898,12 @@ void FullCodeGenerator::EmitVariableAssignment(Variable* var,
         // RecordWrite may destroy all its register arguments.
         __ mov(r3, result_register());
         int offset = Context::SlotOffset(var->index());
-        __ RecordWrite(r1, Operand(offset), r2, r3);
+        __ RecordWriteContextSlot(
+            r1, offset, r3, r2, kLRHasBeenSaved, kDontSaveFPRegs);
       }
     }
 
-  } else if (var->mode() != Variable::CONST) {
+  } else if (var->mode() != CONST) {
     // Assignment to var or initializing assignment to let.
     if (var->IsStackAllocated() || var->IsContextSlot()) {
       MemOperand location = VarOperand(var, r1);
@@ -1887,7 +1917,9 @@ void FullCodeGenerator::EmitVariableAssignment(Variable* var,
       __ str(r0, location);
       if (var->IsContextSlot()) {
         __ mov(r3, r0);
-        __ RecordWrite(r1, Operand(Context::SlotOffset(var->index())), r2, r3);
+        int offset = Context::SlotOffset(var->index());
+        __ RecordWriteContextSlot(
+            r1, offset, r3, r2, kLRHasBeenSaved, kDontSaveFPRegs);
       }
     } else {
       ASSERT(var->IsLookupSlot());
@@ -2107,10 +2139,8 @@ void FullCodeGenerator::EmitResolvePossiblyDirectEval(ResolveEvalFlag flag,
   __ push(r1);
   // Push the strict mode flag. In harmony mode every eval call
   // is a strict mode eval call.
-  StrictModeFlag strict_mode = strict_mode_flag();
-  if (FLAG_harmony_block_scoping) {
-    strict_mode = kStrictMode;
-  }
+  StrictModeFlag strict_mode =
+      FLAG_harmony_scoping ? kStrictMode : strict_mode_flag();
   __ mov(r1, Operand(Smi::FromInt(strict_mode)));
   __ push(r1);
 
@@ -2156,7 +2186,7 @@ void FullCodeGenerator::VisitCall(Call* expr) {
       // context lookup in the runtime system.
       Label done;
       Variable* var = proxy->var();
-      if (!var->IsUnallocated() && var->mode() == Variable::DYNAMIC_GLOBAL) {
+      if (!var->IsUnallocated() && var->mode() == DYNAMIC_GLOBAL) {
         Label slow;
         EmitLoadGlobalCheckExtensions(var, NOT_INSIDE_TYPEOF, &slow);
         // Push the function and resolve eval.
@@ -2662,20 +2692,24 @@ void FullCodeGenerator::EmitClassOf(ZoneList<Expression*>* args) {
 
   // Check that the object is a JS object but take special care of JS
   // functions to make sure they have 'Function' as their class.
+  // Assume that there are only two callable types, and one of them is at
+  // either end of the type range for JS object types. Saves extra comparisons.
+  STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
   __ CompareObjectType(r0, r0, r1, FIRST_SPEC_OBJECT_TYPE);
   // Map is now in r0.
   __ b(lt, &null);
-
-  // As long as LAST_CALLABLE_SPEC_OBJECT_TYPE is the last instance type, and
-  // FIRST_CALLABLE_SPEC_OBJECT_TYPE comes right after
-  // LAST_NONCALLABLE_SPEC_OBJECT_TYPE, we can avoid checking for the latter.
-  STATIC_ASSERT(LAST_TYPE == LAST_CALLABLE_SPEC_OBJECT_TYPE);
-  STATIC_ASSERT(FIRST_CALLABLE_SPEC_OBJECT_TYPE ==
-                LAST_NONCALLABLE_SPEC_OBJECT_TYPE + 1);
-  __ cmp(r1, Operand(FIRST_CALLABLE_SPEC_OBJECT_TYPE));
-  __ b(ge, &function);
-
-  // Check if the constructor in the map is a function.
+  STATIC_ASSERT(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE ==
+                FIRST_SPEC_OBJECT_TYPE + 1);
+  __ b(eq, &function);
+
+  __ cmp(r1, Operand(LAST_SPEC_OBJECT_TYPE));
+  STATIC_ASSERT(LAST_NONCALLABLE_SPEC_OBJECT_TYPE ==
+                LAST_SPEC_OBJECT_TYPE - 1);
+  __ b(eq, &function);
+  // Assume that there is no larger type.
+  STATIC_ASSERT(LAST_NONCALLABLE_SPEC_OBJECT_TYPE == LAST_TYPE - 1);
+
+  // Check if the constructor in the map is a JS function.
   __ ldr(r0, FieldMemOperand(r0, Map::kConstructorOffset));
   __ CompareObjectType(r0, r1, r1, JS_FUNCTION_TYPE);
   __ b(ne, &non_function_constructor);
@@ -2853,7 +2887,9 @@ void FullCodeGenerator::EmitSetValueOf(ZoneList<Expression*>* args) {
   __ str(r0, FieldMemOperand(r1, JSValue::kValueOffset));
   // Update the write barrier.  Save the value as it will be
   // overwritten by the write barrier code and is needed afterward.
-  __ RecordWrite(r1, Operand(JSValue::kValueOffset - kHeapObjectTag), r2, r3);
+  __ mov(r2, r0);
+  __ RecordWriteField(
+      r1, JSValue::kValueOffset, r2, r3, kLRHasBeenSaved, kDontSaveFPRegs);
 
   __ bind(&done);
   context()->Plug(r0);
@@ -3141,16 +3177,31 @@ void FullCodeGenerator::EmitSwapElements(ZoneList<Expression*>* args) {
   __ str(scratch1, MemOperand(index2, 0));
   __ str(scratch2, MemOperand(index1, 0));
 
-  Label new_space;
-  __ InNewSpace(elements, scratch1, eq, &new_space);
+  Label no_remembered_set;
+  __ CheckPageFlag(elements,
+                   scratch1,
+                   1 << MemoryChunk::SCAN_ON_SCAVENGE,
+                   ne,
+                   &no_remembered_set);
   // Possible optimization: do a check that both values are Smis
   // (or them and test against Smi mask.)
 
-  __ mov(scratch1, elements);
-  __ RecordWriteHelper(elements, index1, scratch2);
-  __ RecordWriteHelper(scratch1, index2, scratch2);  // scratch1 holds elements.
+  // We are swapping two objects in an array and the incremental marker never
+  // pauses in the middle of scanning a single object.  Therefore the
+  // incremental marker is not disturbed, so we don't need to call the
+  // RecordWrite stub that notifies the incremental marker.
+  __ RememberedSetHelper(elements,
+                         index1,
+                         scratch2,
+                         kDontSaveFPRegs,
+                         MacroAssembler::kFallThroughAtEnd);
+  __ RememberedSetHelper(elements,
+                         index2,
+                         scratch2,
+                         kDontSaveFPRegs,
+                         MacroAssembler::kFallThroughAtEnd);
 
-  __ bind(&new_space);
+  __ bind(&no_remembered_set);
   // We are done. Drop elements from the stack, and return undefined.
   __ Drop(3);
   __ LoadRoot(r0, Heap::kUndefinedValueRootIndex);
@@ -3898,10 +3949,14 @@ void FullCodeGenerator::VisitForTypeofValue(Expression* expr) {
 
 
 void FullCodeGenerator::EmitLiteralCompareTypeof(Expression* expr,
-                                                 Handle<String> check,
-                                                 Label* if_true,
-                                                 Label* if_false,
-                                                 Label* fall_through) {
+                                                 Handle<String> check) {
+  Label materialize_true, materialize_false;
+  Label* if_true = NULL;
+  Label* if_false = NULL;
+  Label* fall_through = NULL;
+  context()->PrepareTest(&materialize_true, &materialize_false,
+                         &if_true, &if_false, &fall_through);
+
   { AccumulatorValueContext context(this);
     VisitForTypeofValue(expr);
   }
@@ -3942,9 +3997,11 @@ void FullCodeGenerator::EmitLiteralCompareTypeof(Expression* expr,
 
   } else if (check->Equals(isolate()->heap()->function_symbol())) {
     __ JumpIfSmi(r0, if_false);
-    __ CompareObjectType(r0, r1, r0, FIRST_CALLABLE_SPEC_OBJECT_TYPE);
-    Split(ge, if_true, if_false, fall_through);
-
+    STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
+    __ CompareObjectType(r0, r0, r1, JS_FUNCTION_TYPE);
+    __ b(eq, if_true);
+    __ cmp(r1, Operand(JS_FUNCTION_PROXY_TYPE));
+    Split(eq, if_true, if_false, fall_through);
   } else if (check->Equals(isolate()->heap()->object_symbol())) {
     __ JumpIfSmi(r0, if_false);
     if (!FLAG_harmony_typeof) {
@@ -3963,18 +4020,7 @@ void FullCodeGenerator::EmitLiteralCompareTypeof(Expression* expr,
   } else {
     if (if_false != fall_through) __ jmp(if_false);
   }
-}
-
-
-void FullCodeGenerator::EmitLiteralCompareUndefined(Expression* expr,
-                                                    Label* if_true,
-                                                    Label* if_false,
-                                                    Label* fall_through) {
-  VisitForAccumulatorValue(expr);
-  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
-
-  __ CompareRoot(r0, Heap::kUndefinedValueRootIndex);
-  Split(eq, if_true, if_false, fall_through);
+  context()->Plug(if_true, if_false);
 }
 
 
@@ -3982,9 +4028,12 @@ void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
   Comment cmnt(masm_, "[ CompareOperation");
   SetSourcePosition(expr->position());
 
+  // First we try a fast inlined version of the compare when one of
+  // the operands is a literal.
+  if (TryLiteralCompare(expr)) return;
+
   // Always perform the comparison for its control flow.  Pack the result
   // into the expression's context after the comparison is performed.
-
   Label materialize_true, materialize_false;
   Label* if_true = NULL;
   Label* if_false = NULL;
@@ -3992,13 +4041,6 @@ void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
   context()->PrepareTest(&materialize_true, &materialize_false,
                          &if_true, &if_false, &fall_through);
 
-  // First we try a fast inlined version of the compare when one of
-  // the operands is a literal.
-  if (TryLiteralCompare(expr, if_true, if_false, fall_through)) {
-    context()->Plug(if_true, if_false);
-    return;
-  }
-
   Token::Value op = expr->op();
   VisitForStackValue(expr->left());
   switch (op) {
@@ -4085,8 +4127,9 @@ void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
 }
 
 
-void FullCodeGenerator::VisitCompareToNull(CompareToNull* expr) {
-  Comment cmnt(masm_, "[ CompareToNull");
+void FullCodeGenerator::EmitLiteralCompareNil(CompareOperation* expr,
+                                              Expression* sub_expr,
+                                              NilValue nil) {
   Label materialize_true, materialize_false;
   Label* if_true = NULL;
   Label* if_false = NULL;
@@ -4094,15 +4137,21 @@ void FullCodeGenerator::VisitCompareToNull(CompareToNull* expr) {
   context()->PrepareTest(&materialize_true, &materialize_false,
                          &if_true, &if_false, &fall_through);
 
-  VisitForAccumulatorValue(expr->expression());
+  VisitForAccumulatorValue(sub_expr);
   PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
-  __ LoadRoot(r1, Heap::kNullValueRootIndex);
+  Heap::RootListIndex nil_value = nil == kNullValue ?
+      Heap::kNullValueRootIndex :
+      Heap::kUndefinedValueRootIndex;
+  __ LoadRoot(r1, nil_value);
   __ cmp(r0, r1);
-  if (expr->is_strict()) {
+  if (expr->op() == Token::EQ_STRICT) {
     Split(eq, if_true, if_false, fall_through);
   } else {
+    Heap::RootListIndex other_nil_value = nil == kNullValue ?
+        Heap::kUndefinedValueRootIndex :
+        Heap::kNullValueRootIndex;
     __ b(eq, if_true);
-    __ LoadRoot(r1, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(r1, other_nil_value);
     __ cmp(r0, r1);
     __ b(eq, if_true);
     __ JumpIfSmi(r0, if_false);
diff --git a/deps/v8/src/arm/ic-arm.cc b/deps/v8/src/arm/ic-arm.cc
index 2e49cae92..6e0badca1 100644
--- a/deps/v8/src/arm/ic-arm.cc
+++ b/deps/v8/src/arm/ic-arm.cc
@@ -208,7 +208,8 @@ static void GenerateDictionaryStore(MacroAssembler* masm,
 
   // Update the write barrier. Make sure not to clobber the value.
   __ mov(scratch1, value);
-  __ RecordWrite(elements, scratch2, scratch1);
+  __ RecordWrite(
+      elements, scratch2, scratch1, kLRHasNotBeenSaved, kDontSaveFPRegs);
 }
 
 
@@ -504,21 +505,22 @@ static void GenerateCallMiss(MacroAssembler* masm,
   // Get the receiver of the function from the stack.
   __ ldr(r3, MemOperand(sp, argc * kPointerSize));
 
-  __ EnterInternalFrame();
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
 
-  // Push the receiver and the name of the function.
-  __ Push(r3, r2);
+    // Push the receiver and the name of the function.
+    __ Push(r3, r2);
 
-  // Call the entry.
-  __ mov(r0, Operand(2));
-  __ mov(r1, Operand(ExternalReference(IC_Utility(id), isolate)));
+    // Call the entry.
+    __ mov(r0, Operand(2));
+    __ mov(r1, Operand(ExternalReference(IC_Utility(id), isolate)));
 
-  CEntryStub stub(1);
-  __ CallStub(&stub);
+    CEntryStub stub(1);
+    __ CallStub(&stub);
 
-  // Move result to r1 and leave the internal frame.
-  __ mov(r1, Operand(r0));
-  __ LeaveInternalFrame();
+    // Move result to r1 and leave the internal frame.
+    __ mov(r1, Operand(r0));
+  }
 
   // Check if the receiver is a global object of some sort.
   // This can happen only for regular CallIC but not KeyedCallIC.
@@ -650,12 +652,13 @@ void KeyedCallIC::GenerateMegamorphic(MacroAssembler* masm, int argc) {
   // This branch is taken when calling KeyedCallIC_Miss is neither required
   // nor beneficial.
   __ IncrementCounter(counters->keyed_call_generic_slow_load(), 1, r0, r3);
-  __ EnterInternalFrame();
-  __ push(r2);  // save the key
-  __ Push(r1, r2);  // pass the receiver and the key
-  __ CallRuntime(Runtime::kKeyedGetProperty, 2);
-  __ pop(r2);  // restore the key
-  __ LeaveInternalFrame();
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
+    __ push(r2);  // save the key
+    __ Push(r1, r2);  // pass the receiver and the key
+    __ CallRuntime(Runtime::kKeyedGetProperty, 2);
+    __ pop(r2);  // restore the key
+  }
   __ mov(r1, r0);
   __ jmp(&do_call);
 
@@ -908,7 +911,8 @@ void KeyedStoreIC::GenerateNonStrictArguments(MacroAssembler* masm) {
       GenerateMappedArgumentsLookup(masm, r2, r1, r3, r4, r5, &notin, &slow);
   __ str(r0, mapped_location);
   __ add(r6, r3, r5);
-  __ RecordWrite(r3, r6, r9);
+  __ mov(r9, r0);
+  __ RecordWrite(r3, r6, r9, kLRHasNotBeenSaved, kDontSaveFPRegs);
   __ Ret();
   __ bind(&notin);
   // The unmapped lookup expects that the parameter map is in r3.
@@ -916,7 +920,8 @@ void KeyedStoreIC::GenerateNonStrictArguments(MacroAssembler* masm) {
       GenerateUnmappedArgumentsLookup(masm, r1, r3, r4, &slow);
   __ str(r0, unmapped_location);
   __ add(r6, r3, r4);
-  __ RecordWrite(r3, r6, r9);
+  __ mov(r9, r0);
+  __ RecordWrite(r3, r6, r9, kLRHasNotBeenSaved, kDontSaveFPRegs);
   __ Ret();
   __ bind(&slow);
   GenerateMiss(masm, false);
@@ -1267,13 +1272,17 @@ void KeyedStoreIC::GenerateGeneric(MacroAssembler* masm,
   //  -- r2     : receiver
   //  -- lr     : return address
   // -----------------------------------
-  Label slow, fast, array, extra;
+  Label slow, array, extra, check_if_double_array;
+  Label fast_object_with_map_check, fast_object_without_map_check;
+  Label fast_double_with_map_check, fast_double_without_map_check;
 
   // Register usage.
   Register value = r0;
   Register key = r1;
   Register receiver = r2;
   Register elements = r3;  // Elements array of the receiver.
+  Register elements_map = r6;
+  Register receiver_map = r7;
   // r4 and r5 are used as general scratch registers.
 
   // Check that the key is a smi.
@@ -1281,35 +1290,26 @@ void KeyedStoreIC::GenerateGeneric(MacroAssembler* masm,
   // Check that the object isn't a smi.
   __ JumpIfSmi(receiver, &slow);
   // Get the map of the object.
-  __ ldr(r4, FieldMemOperand(receiver, HeapObject::kMapOffset));
+  __ ldr(receiver_map, FieldMemOperand(receiver, HeapObject::kMapOffset));
   // Check that the receiver does not require access checks.  We need
   // to do this because this generic stub does not perform map checks.
-  __ ldrb(ip, FieldMemOperand(r4, Map::kBitFieldOffset));
+  __ ldrb(ip, FieldMemOperand(receiver_map, Map::kBitFieldOffset));
   __ tst(ip, Operand(1 << Map::kIsAccessCheckNeeded));
   __ b(ne, &slow);
   // Check if the object is a JS array or not.
-  __ ldrb(r4, FieldMemOperand(r4, Map::kInstanceTypeOffset));
+  __ ldrb(r4, FieldMemOperand(receiver_map, Map::kInstanceTypeOffset));
   __ cmp(r4, Operand(JS_ARRAY_TYPE));
   __ b(eq, &array);
   // Check that the object is some kind of JSObject.
-  __ cmp(r4, Operand(FIRST_JS_RECEIVER_TYPE));
+  __ cmp(r4, Operand(FIRST_JS_OBJECT_TYPE));
   __ b(lt, &slow);
-  __ cmp(r4, Operand(JS_PROXY_TYPE));
-  __ b(eq, &slow);
-  __ cmp(r4, Operand(JS_FUNCTION_PROXY_TYPE));
-  __ b(eq, &slow);
 
   // Object case: Check key against length in the elements array.
   __ ldr(elements, FieldMemOperand(receiver, JSObject::kElementsOffset));
-  // Check that the object is in fast mode and writable.
-  __ ldr(r4, FieldMemOperand(elements, HeapObject::kMapOffset));
-  __ LoadRoot(ip, Heap::kFixedArrayMapRootIndex);
-  __ cmp(r4, ip);
-  __ b(ne, &slow);
   // Check array bounds. Both the key and the length of FixedArray are smis.
   __ ldr(ip, FieldMemOperand(elements, FixedArray::kLengthOffset));
   __ cmp(key, Operand(ip));
-  __ b(lo, &fast);
+  __ b(lo, &fast_object_with_map_check);
 
   // Slow case, handle jump to runtime.
   __ bind(&slow);
@@ -1330,21 +1330,31 @@ void KeyedStoreIC::GenerateGeneric(MacroAssembler* masm,
   __ ldr(ip, FieldMemOperand(elements, FixedArray::kLengthOffset));
   __ cmp(key, Operand(ip));
   __ b(hs, &slow);
+  __ ldr(elements_map, FieldMemOperand(elements, HeapObject::kMapOffset));
+  __ cmp(elements_map,
+         Operand(masm->isolate()->factory()->fixed_array_map()));
+  __ b(ne, &check_if_double_array);
   // Calculate key + 1 as smi.
   STATIC_ASSERT(kSmiTag == 0);
   __ add(r4, key, Operand(Smi::FromInt(1)));
   __ str(r4, FieldMemOperand(receiver, JSArray::kLengthOffset));
-  __ b(&fast);
+  __ b(&fast_object_without_map_check);
+
+  __ bind(&check_if_double_array);
+  __ cmp(elements_map,
+         Operand(masm->isolate()->factory()->fixed_double_array_map()));
+  __ b(ne, &slow);
+  // Add 1 to key, and go to common element store code for doubles.
+  STATIC_ASSERT(kSmiTag == 0);
+  __ add(r4, key, Operand(Smi::FromInt(1)));
+  __ str(r4, FieldMemOperand(receiver, JSArray::kLengthOffset));
+  __ jmp(&fast_double_without_map_check);
 
   // Array case: Get the length and the elements array from the JS
   // array. Check that the array is in fast mode (and writable); if it
   // is the length is always a smi.
   __ bind(&array);
   __ ldr(elements, FieldMemOperand(receiver, JSObject::kElementsOffset));
-  __ ldr(r4, FieldMemOperand(elements, HeapObject::kMapOffset));
-  __ LoadRoot(ip, Heap::kFixedArrayMapRootIndex);
-  __ cmp(r4, ip);
-  __ b(ne, &slow);
 
   // Check the key against the length in the array.
   __ ldr(ip, FieldMemOperand(receiver, JSArray::kLengthOffset));
@@ -1352,18 +1362,57 @@ void KeyedStoreIC::GenerateGeneric(MacroAssembler* masm,
   __ b(hs, &extra);
   // Fall through to fast case.
 
-  __ bind(&fast);
-  // Fast case, store the value to the elements backing store.
-  __ add(r5, elements, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
-  __ add(r5, r5, Operand(key, LSL, kPointerSizeLog2 - kSmiTagSize));
-  __ str(value, MemOperand(r5));
-  // Skip write barrier if the written value is a smi.
-  __ tst(value, Operand(kSmiTagMask));
-  __ Ret(eq);
+  __ bind(&fast_object_with_map_check);
+  Register scratch_value = r4;
+  Register address = r5;
+  __ ldr(elements_map, FieldMemOperand(elements, HeapObject::kMapOffset));
+  __ cmp(elements_map,
+         Operand(masm->isolate()->factory()->fixed_array_map()));
+  __ b(ne, &fast_double_with_map_check);
+  __ bind(&fast_object_without_map_check);
+  // Smi stores don't require further checks.
+  Label non_smi_value;
+  __ JumpIfNotSmi(value, &non_smi_value);
+  // It's irrelevant whether array is smi-only or not when writing a smi.
+  __ add(address, elements, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+  __ add(address, address, Operand(key, LSL, kPointerSizeLog2 - kSmiTagSize));
+  __ str(value, MemOperand(address));
+  __ Ret();
+
+  __ bind(&non_smi_value);
+  // Escape to slow case when writing non-smi into smi-only array.
+  __ CheckFastObjectElements(receiver_map, scratch_value, &slow);
+  // Fast elements array, store the value to the elements backing store.
+  __ add(address, elements, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+  __ add(address, address, Operand(key, LSL, kPointerSizeLog2 - kSmiTagSize));
+  __ str(value, MemOperand(address));
   // Update write barrier for the elements array address.
-  __ sub(r4, r5, Operand(elements));
-  __ RecordWrite(elements, Operand(r4), r5, r6);
+  __ mov(scratch_value, value);  // Preserve the value which is returned.
+  __ RecordWrite(elements,
+                 address,
+                 scratch_value,
+                 kLRHasNotBeenSaved,
+                 kDontSaveFPRegs,
+                 EMIT_REMEMBERED_SET,
+                 OMIT_SMI_CHECK);
+  __ Ret();
 
+  __ bind(&fast_double_with_map_check);
+  // Check for fast double array case. If this fails, call through to the
+  // runtime.
+  __ cmp(elements_map,
+         Operand(masm->isolate()->factory()->fixed_double_array_map()));
+  __ b(ne, &slow);
+  __ bind(&fast_double_without_map_check);
+  __ StoreNumberToDoubleElements(value,
+                                 key,
+                                 receiver,
+                                 elements,
+                                 r4,
+                                 r5,
+                                 r6,
+                                 r7,
+                                 &slow);
   __ Ret();
 }
 
diff --git a/deps/v8/src/arm/lithium-arm.cc b/deps/v8/src/arm/lithium-arm.cc
index 30ccd05be..84959397b 100644
--- a/deps/v8/src/arm/lithium-arm.cc
+++ b/deps/v8/src/arm/lithium-arm.cc
@@ -212,10 +212,11 @@ void LCmpIDAndBranch::PrintDataTo(StringStream* stream) {
 }
 
 
-void LIsNullAndBranch::PrintDataTo(StringStream* stream) {
+void LIsNilAndBranch::PrintDataTo(StringStream* stream) {
   stream->Add("if ");
   InputAt(0)->PrintTo(stream);
-  stream->Add(is_strict() ? " === null" : " == null");
+  stream->Add(kind() == kStrictEquality ? " === " : " == ");
+  stream->Add(nil() == kNullValue ? "null" : "undefined");
   stream->Add(" then B%d else B%d", true_block_id(), false_block_id());
 }
 
@@ -711,7 +712,9 @@ LInstruction* LChunkBuilder::DefineFixedDouble(
 
 LInstruction* LChunkBuilder::AssignEnvironment(LInstruction* instr) {
   HEnvironment* hydrogen_env = current_block_->last_environment();
-  instr->set_environment(CreateEnvironment(hydrogen_env));
+  int argument_index_accumulator = 0;
+  instr->set_environment(CreateEnvironment(hydrogen_env,
+                                           &argument_index_accumulator));
   return instr;
 }
 
@@ -994,10 +997,13 @@ void LChunkBuilder::VisitInstruction(HInstruction* current) {
 }
 
 
-LEnvironment* LChunkBuilder::CreateEnvironment(HEnvironment* hydrogen_env) {
+LEnvironment* LChunkBuilder::CreateEnvironment(
+    HEnvironment* hydrogen_env,
+    int* argument_index_accumulator) {
   if (hydrogen_env == NULL) return NULL;
 
-  LEnvironment* outer = CreateEnvironment(hydrogen_env->outer());
+  LEnvironment* outer =
+      CreateEnvironment(hydrogen_env->outer(), argument_index_accumulator);
   int ast_id = hydrogen_env->ast_id();
   ASSERT(ast_id != AstNode::kNoNumber);
   int value_count = hydrogen_env->length();
@@ -1007,7 +1013,6 @@ LEnvironment* LChunkBuilder::CreateEnvironment(HEnvironment* hydrogen_env) {
                                           argument_count_,
                                           value_count,
                                           outer);
-  int argument_index = 0;
   for (int i = 0; i < value_count; ++i) {
     if (hydrogen_env->is_special_index(i)) continue;
 
@@ -1016,7 +1021,7 @@ LEnvironment* LChunkBuilder::CreateEnvironment(HEnvironment* hydrogen_env) {
     if (value->IsArgumentsObject()) {
       op = NULL;
     } else if (value->IsPushArgument()) {
-      op = new LArgument(argument_index++);
+      op = new LArgument((*argument_index_accumulator)++);
     } else {
       op = UseAny(value);
     }
@@ -1444,9 +1449,9 @@ LInstruction* LChunkBuilder::DoCompareConstantEqAndBranch(
 }
 
 
-LInstruction* LChunkBuilder::DoIsNullAndBranch(HIsNullAndBranch* instr) {
+LInstruction* LChunkBuilder::DoIsNilAndBranch(HIsNilAndBranch* instr) {
   ASSERT(instr->value()->representation().IsTagged());
-  return new LIsNullAndBranch(UseRegisterAtStart(instr->value()));
+  return new LIsNilAndBranch(UseRegisterAtStart(instr->value()));
 }
 
 
@@ -1734,7 +1739,7 @@ LInstruction* LChunkBuilder::DoConstant(HConstant* instr) {
 
 LInstruction* LChunkBuilder::DoLoadGlobalCell(HLoadGlobalCell* instr) {
   LLoadGlobalCell* result = new LLoadGlobalCell;
-  return instr->check_hole_value()
+  return instr->RequiresHoleCheck()
       ? AssignEnvironment(DefineAsRegister(result))
       : DefineAsRegister(result);
 }
@@ -1748,14 +1753,11 @@ LInstruction* LChunkBuilder::DoLoadGlobalGeneric(HLoadGlobalGeneric* instr) {
 
 
 LInstruction* LChunkBuilder::DoStoreGlobalCell(HStoreGlobalCell* instr) {
-  if (instr->check_hole_value()) {
-    LOperand* temp = TempRegister();
-    LOperand* value = UseRegister(instr->value());
-    return AssignEnvironment(new LStoreGlobalCell(value, temp));
-  } else {
-    LOperand* value = UseRegisterAtStart(instr->value());
-    return new LStoreGlobalCell(value, NULL);
-  }
+  LOperand* temp = TempRegister();
+  LOperand* value = UseTempRegister(instr->value());
+  LInstruction* result = new LStoreGlobalCell(value, temp);
+  if (instr->RequiresHoleCheck()) result = AssignEnvironment(result);
+  return result;
 }
 
 
diff --git a/deps/v8/src/arm/lithium-arm.h b/deps/v8/src/arm/lithium-arm.h
index 8c18760fd..73c7e459c 100644
--- a/deps/v8/src/arm/lithium-arm.h
+++ b/deps/v8/src/arm/lithium-arm.h
@@ -107,7 +107,7 @@ class LCodeGen;
   V(Integer32ToDouble)                          \
   V(InvokeFunction)                             \
   V(IsConstructCallAndBranch)                   \
-  V(IsNullAndBranch)                            \
+  V(IsNilAndBranch)                             \
   V(IsObjectAndBranch)                          \
   V(IsSmiAndBranch)                             \
   V(IsUndetectableAndBranch)                    \
@@ -627,16 +627,17 @@ class LCmpConstantEqAndBranch: public LControlInstruction<1, 0> {
 };
 
 
-class LIsNullAndBranch: public LControlInstruction<1, 0> {
+class LIsNilAndBranch: public LControlInstruction<1, 0> {
  public:
-  explicit LIsNullAndBranch(LOperand* value) {
+  explicit LIsNilAndBranch(LOperand* value) {
     inputs_[0] = value;
   }
 
-  DECLARE_CONCRETE_INSTRUCTION(IsNullAndBranch, "is-null-and-branch")
-  DECLARE_HYDROGEN_ACCESSOR(IsNullAndBranch)
+  DECLARE_CONCRETE_INSTRUCTION(IsNilAndBranch, "is-nil-and-branch")
+  DECLARE_HYDROGEN_ACCESSOR(IsNilAndBranch)
 
-  bool is_strict() const { return hydrogen()->is_strict(); }
+  EqualityKind kind() const { return hydrogen()->kind(); }
+  NilValue nil() const { return hydrogen()->nil(); }
 
   virtual void PrintDataTo(StringStream* stream);
 };
@@ -2159,7 +2160,8 @@ class LChunkBuilder BASE_EMBEDDED {
       LInstruction* instr, int ast_id);
   void ClearInstructionPendingDeoptimizationEnvironment();
 
-  LEnvironment* CreateEnvironment(HEnvironment* hydrogen_env);
+  LEnvironment* CreateEnvironment(HEnvironment* hydrogen_env,
+                                  int* argument_index_accumulator);
 
   void VisitInstruction(HInstruction* current);
 
diff --git a/deps/v8/src/arm/lithium-codegen-arm.cc b/deps/v8/src/arm/lithium-codegen-arm.cc
index f5d744914..70ef88481 100644
--- a/deps/v8/src/arm/lithium-codegen-arm.cc
+++ b/deps/v8/src/arm/lithium-codegen-arm.cc
@@ -82,6 +82,14 @@ bool LCodeGen::GenerateCode() {
   status_ = GENERATING;
   CpuFeatures::Scope scope1(VFP3);
   CpuFeatures::Scope scope2(ARMv7);
+
+  CodeStub::GenerateFPStubs();
+
+  // Open a frame scope to indicate that there is a frame on the stack.  The
+  // NONE indicates that the scope shouldn't actually generate code to set up
+  // the frame (that is done in GeneratePrologue).
+  FrameScope frame_scope(masm_, StackFrame::NONE);
+
   return GeneratePrologue() &&
       GenerateBody() &&
       GenerateDeferredCode() &&
@@ -206,13 +214,11 @@ bool LCodeGen::GeneratePrologue() {
         // Load parameter from stack.
         __ ldr(r0, MemOperand(fp, parameter_offset));
         // Store it in the context.
-        __ mov(r1, Operand(Context::SlotOffset(var->index())));
-        __ str(r0, MemOperand(cp, r1));
-        // Update the write barrier. This clobbers all involved
-        // registers, so we have to use two more registers to avoid
-        // clobbering cp.
-        __ mov(r2, Operand(cp));
-        __ RecordWrite(r2, Operand(r1), r3, r0);
+        MemOperand target = ContextOperand(cp, var->index());
+        __ str(r0, target);
+        // Update the write barrier. This clobbers r3 and r0.
+        __ RecordWriteContextSlot(
+            cp, target.offset(), r0, r3, kLRHasBeenSaved, kSaveFPRegs);
       }
     }
     Comment(";;; End allocate local context");
@@ -262,6 +268,9 @@ bool LCodeGen::GenerateDeferredCode() {
     for (int i = 0; !is_aborted() && i < deferred_.length(); i++) {
       LDeferredCode* code = deferred_[i];
       __ bind(code->entry());
+      Comment(";;; Deferred code @%d: %s.",
+              code->instruction_index(),
+              code->instr()->Mnemonic());
       code->Generate();
       __ jmp(code->exit());
     }
@@ -739,7 +748,7 @@ void LCodeGen::RecordSafepoint(
     int deoptimization_index) {
   ASSERT(expected_safepoint_kind_ == kind);
 
-  const ZoneList<LOperand*>* operands = pointers->operands();
+  const ZoneList<LOperand*>* operands = pointers->GetNormalizedOperands();
   Safepoint safepoint = safepoints_.DefineSafepoint(masm(),
       kind, arguments, deoptimization_index);
   for (int i = 0; i < operands->length(); i++) {
@@ -1032,6 +1041,7 @@ void LCodeGen::DoDivI(LDivI* instr) {
     virtual void Generate() {
       codegen()->DoDeferredBinaryOpStub(instr_, Token::DIV);
     }
+    virtual LInstruction* instr() { return instr_; }
    private:
     LDivI* instr_;
   };
@@ -1743,25 +1753,35 @@ void LCodeGen::DoCmpConstantEqAndBranch(LCmpConstantEqAndBranch* instr) {
 }
 
 
-void LCodeGen::DoIsNullAndBranch(LIsNullAndBranch* instr) {
+void LCodeGen::DoIsNilAndBranch(LIsNilAndBranch* instr) {
   Register scratch = scratch0();
   Register reg = ToRegister(instr->InputAt(0));
+  int false_block = chunk_->LookupDestination(instr->false_block_id());
 
-  // TODO(fsc): If the expression is known to be a smi, then it's
-  // definitely not null. Jump to the false block.
+  // If the expression is known to be untagged or a smi, then it's definitely
+  // not null, and it can't be a an undetectable object.
+  if (instr->hydrogen()->representation().IsSpecialization() ||
+      instr->hydrogen()->type().IsSmi()) {
+    EmitGoto(false_block);
+    return;
+  }
 
   int true_block = chunk_->LookupDestination(instr->true_block_id());
-  int false_block = chunk_->LookupDestination(instr->false_block_id());
-
-  __ LoadRoot(ip, Heap::kNullValueRootIndex);
+  Heap::RootListIndex nil_value = instr->nil() == kNullValue ?
+      Heap::kNullValueRootIndex :
+      Heap::kUndefinedValueRootIndex;
+  __ LoadRoot(ip, nil_value);
   __ cmp(reg, ip);
-  if (instr->is_strict()) {
+  if (instr->kind() == kStrictEquality) {
     EmitBranch(true_block, false_block, eq);
   } else {
+    Heap::RootListIndex other_nil_value = instr->nil() == kNullValue ?
+        Heap::kUndefinedValueRootIndex :
+        Heap::kNullValueRootIndex;
     Label* true_label = chunk_->GetAssemblyLabel(true_block);
     Label* false_label = chunk_->GetAssemblyLabel(false_block);
     __ b(eq, true_label);
-    __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
+    __ LoadRoot(ip, other_nil_value);
     __ cmp(reg, ip);
     __ b(eq, true_label);
     __ JumpIfSmi(reg, false_label);
@@ -1918,28 +1938,36 @@ void LCodeGen::EmitClassOfTest(Label* is_true,
   ASSERT(!input.is(temp));
   ASSERT(!temp.is(temp2));  // But input and temp2 may be the same register.
   __ JumpIfSmi(input, is_false);
-  __ CompareObjectType(input, temp, temp2, FIRST_SPEC_OBJECT_TYPE);
-  __ b(lt, is_false);
 
-  // Map is now in temp.
-  // Functions have class 'Function'.
-  __ CompareInstanceType(temp, temp2, FIRST_CALLABLE_SPEC_OBJECT_TYPE);
   if (class_name->IsEqualTo(CStrVector("Function"))) {
-    __ b(ge, is_true);
+    // Assuming the following assertions, we can use the same compares to test
+    // for both being a function type and being in the object type range.
+    STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
+    STATIC_ASSERT(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE ==
+                  FIRST_SPEC_OBJECT_TYPE + 1);
+    STATIC_ASSERT(LAST_NONCALLABLE_SPEC_OBJECT_TYPE ==
+                  LAST_SPEC_OBJECT_TYPE - 1);
+    STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
+    __ CompareObjectType(input, temp, temp2, FIRST_SPEC_OBJECT_TYPE);
+    __ b(lt, is_false);
+    __ b(eq, is_true);
+    __ cmp(temp2, Operand(LAST_SPEC_OBJECT_TYPE));
+    __ b(eq, is_true);
   } else {
-    __ b(ge, is_false);
+    // Faster code path to avoid two compares: subtract lower bound from the
+    // actual type and do a signed compare with the width of the type range.
+    __ ldr(temp, FieldMemOperand(input, HeapObject::kMapOffset));
+    __ ldrb(temp2, FieldMemOperand(temp, Map::kInstanceTypeOffset));
+    __ sub(temp2, temp2, Operand(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
+    __ cmp(temp2, Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE -
+                          FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
+    __ b(gt, is_false);
   }
 
+  // Now we are in the FIRST-LAST_NONCALLABLE_SPEC_OBJECT_TYPE range.
   // Check if the constructor in the map is a function.
   __ ldr(temp, FieldMemOperand(temp, Map::kConstructorOffset));
 
-  // As long as LAST_CALLABLE_SPEC_OBJECT_TYPE is the last instance type and
-  // FIRST_CALLABLE_SPEC_OBJECT_TYPE comes right after
-  // LAST_NONCALLABLE_SPEC_OBJECT_TYPE, we can avoid checking for the latter.
-  STATIC_ASSERT(LAST_TYPE == LAST_CALLABLE_SPEC_OBJECT_TYPE);
-  STATIC_ASSERT(FIRST_CALLABLE_SPEC_OBJECT_TYPE ==
-                LAST_NONCALLABLE_SPEC_OBJECT_TYPE + 1);
-
   // Objects with a non-function constructor have class 'Object'.
   __ CompareObjectType(temp, temp2, temp2, JS_FUNCTION_TYPE);
   if (class_name->IsEqualTo(CStrVector("Object"))) {
@@ -2016,9 +2044,8 @@ void LCodeGen::DoInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr) {
     virtual void Generate() {
       codegen()->DoDeferredLInstanceOfKnownGlobal(instr_, &map_check_);
     }
-
+    virtual LInstruction* instr() { return instr_; }
     Label* map_check() { return &map_check_; }
-
    private:
     LInstanceOfKnownGlobal* instr_;
     Label map_check_;
@@ -2180,7 +2207,7 @@ void LCodeGen::DoLoadGlobalCell(LLoadGlobalCell* instr) {
   Register result = ToRegister(instr->result());
   __ mov(ip, Operand(Handle<Object>(instr->hydrogen()->cell())));
   __ ldr(result, FieldMemOperand(ip, JSGlobalPropertyCell::kValueOffset));
-  if (instr->hydrogen()->check_hole_value()) {
+  if (instr->hydrogen()->RequiresHoleCheck()) {
     __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
     __ cmp(result, ip);
     DeoptimizeIf(eq, instr->environment());
@@ -2203,6 +2230,7 @@ void LCodeGen::DoLoadGlobalGeneric(LLoadGlobalGeneric* instr) {
 void LCodeGen::DoStoreGlobalCell(LStoreGlobalCell* instr) {
   Register value = ToRegister(instr->InputAt(0));
   Register scratch = scratch0();
+  Register scratch2 = ToRegister(instr->TempAt(0));
 
   // Load the cell.
   __ mov(scratch, Operand(Handle<Object>(instr->hydrogen()->cell())));
@@ -2211,8 +2239,7 @@ void LCodeGen::DoStoreGlobalCell(LStoreGlobalCell* instr) {
   // been deleted from the property dictionary. In that case, we need
   // to update the property details in the property dictionary to mark
   // it as no longer deleted.
-  if (instr->hydrogen()->check_hole_value()) {
-    Register scratch2 = ToRegister(instr->TempAt(0));
+  if (instr->hydrogen()->RequiresHoleCheck()) {
     __ ldr(scratch2,
            FieldMemOperand(scratch, JSGlobalPropertyCell::kValueOffset));
     __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
@@ -2222,6 +2249,15 @@ void LCodeGen::DoStoreGlobalCell(LStoreGlobalCell* instr) {
 
   // Store the value.
   __ str(value, FieldMemOperand(scratch, JSGlobalPropertyCell::kValueOffset));
+
+  // Cells are always in the remembered set.
+  __ RecordWriteField(scratch,
+                      JSGlobalPropertyCell::kValueOffset,
+                      value,
+                      scratch2,
+                      kLRHasBeenSaved,
+                      kSaveFPRegs,
+                      OMIT_REMEMBERED_SET);
 }
 
 
@@ -2247,10 +2283,15 @@ void LCodeGen::DoLoadContextSlot(LLoadContextSlot* instr) {
 void LCodeGen::DoStoreContextSlot(LStoreContextSlot* instr) {
   Register context = ToRegister(instr->context());
   Register value = ToRegister(instr->value());
-  __ str(value, ContextOperand(context, instr->slot_index()));
+  MemOperand target = ContextOperand(context, instr->slot_index());
+  __ str(value, target);
   if (instr->needs_write_barrier()) {
-    int offset = Context::SlotOffset(instr->slot_index());
-    __ RecordWrite(context, Operand(offset), value, scratch0());
+    __ RecordWriteContextSlot(context,
+                              target.offset(),
+                              value,
+                              scratch0(),
+                              kLRHasBeenSaved,
+                              kSaveFPRegs);
   }
 }
 
@@ -2500,13 +2541,9 @@ void LCodeGen::DoLoadKeyedFastDoubleElement(
            Operand(FixedDoubleArray::kHeaderSize - kHeapObjectTag));
   }
 
-  if (instr->hydrogen()->RequiresHoleCheck()) {
-    // TODO(danno): If no hole check is required, there is no need to allocate
-    // elements into a temporary register, instead scratch can be used.
-    __ ldr(scratch, MemOperand(elements, sizeof(kHoleNanLower32)));
-    __ cmp(scratch, Operand(kHoleNanUpper32));
-    DeoptimizeIf(eq, instr->environment());
-  }
+  __ ldr(scratch, MemOperand(elements, sizeof(kHoleNanLower32)));
+  __ cmp(scratch, Operand(kHoleNanUpper32));
+  DeoptimizeIf(eq, instr->environment());
 
   __ vldr(result, elements, 0);
 }
@@ -2577,6 +2614,7 @@ void LCodeGen::DoLoadKeyedSpecializedArrayElement(
       case EXTERNAL_DOUBLE_ELEMENTS:
       case FAST_DOUBLE_ELEMENTS:
       case FAST_ELEMENTS:
+      case FAST_SMI_ONLY_ELEMENTS:
       case DICTIONARY_ELEMENTS:
       case NON_STRICT_ARGUMENTS_ELEMENTS:
         UNREACHABLE();
@@ -2906,6 +2944,7 @@ void LCodeGen::DoMathAbs(LUnaryMathOperation* instr) {
     virtual void Generate() {
       codegen()->DoDeferredMathAbsTaggedHeapNumber(instr_);
     }
+    virtual LInstruction* instr() { return instr_; }
    private:
     LUnaryMathOperation* instr_;
   };
@@ -3202,7 +3241,7 @@ void LCodeGen::DoCallFunction(LCallFunction* instr) {
   ASSERT(ToRegister(instr->result()).is(r0));
 
   int arity = instr->arity();
-  CallFunctionStub stub(arity, RECEIVER_MIGHT_BE_IMPLICIT);
+  CallFunctionStub stub(arity, NO_CALL_FUNCTION_FLAGS);
   CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
   __ Drop(1);
   __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
@@ -3262,7 +3301,8 @@ void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
     __ str(value, FieldMemOperand(object, offset));
     if (instr->needs_write_barrier()) {
       // Update the write barrier for the object for in-object properties.
-      __ RecordWrite(object, Operand(offset), value, scratch);
+      __ RecordWriteField(
+          object, offset, value, scratch, kLRHasBeenSaved, kSaveFPRegs);
     }
   } else {
     __ ldr(scratch, FieldMemOperand(object, JSObject::kPropertiesOffset));
@@ -3270,7 +3310,8 @@ void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
     if (instr->needs_write_barrier()) {
       // Update the write barrier for the properties array.
       // object is used as a scratch register.
-      __ RecordWrite(scratch, Operand(offset), value, object);
+      __ RecordWriteField(
+          scratch, offset, value, object, kLRHasBeenSaved, kSaveFPRegs);
     }
   }
 }
@@ -3301,6 +3342,13 @@ void LCodeGen::DoStoreKeyedFastElement(LStoreKeyedFastElement* instr) {
   Register key = instr->key()->IsRegister() ? ToRegister(instr->key()) : no_reg;
   Register scratch = scratch0();
 
+  // This instruction cannot handle the FAST_SMI_ONLY_ELEMENTS -> FAST_ELEMENTS
+  // conversion, so it deopts in that case.
+  if (instr->hydrogen()->ValueNeedsSmiCheck()) {
+    __ tst(value, Operand(kSmiTagMask));
+    DeoptimizeIf(ne, instr->environment());
+  }
+
   // Do the store.
   if (instr->key()->IsConstantOperand()) {
     ASSERT(!instr->hydrogen()->NeedsWriteBarrier());
@@ -3315,8 +3363,8 @@ void LCodeGen::DoStoreKeyedFastElement(LStoreKeyedFastElement* instr) {
 
   if (instr->hydrogen()->NeedsWriteBarrier()) {
     // Compute address of modified element and store it into key register.
-    __ add(key, scratch, Operand(FixedArray::kHeaderSize));
-    __ RecordWrite(elements, key, value);
+    __ add(key, scratch, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+    __ RecordWrite(elements, key, value, kLRHasBeenSaved, kSaveFPRegs);
   }
 }
 
@@ -3417,6 +3465,7 @@ void LCodeGen::DoStoreKeyedSpecializedArrayElement(
       case EXTERNAL_DOUBLE_ELEMENTS:
       case FAST_DOUBLE_ELEMENTS:
       case FAST_ELEMENTS:
+      case FAST_SMI_ONLY_ELEMENTS:
       case DICTIONARY_ELEMENTS:
       case NON_STRICT_ARGUMENTS_ELEMENTS:
         UNREACHABLE();
@@ -3452,6 +3501,7 @@ void LCodeGen::DoStringCharCodeAt(LStringCharCodeAt* instr) {
     DeferredStringCharCodeAt(LCodeGen* codegen, LStringCharCodeAt* instr)
         : LDeferredCode(codegen), instr_(instr) { }
     virtual void Generate() { codegen()->DoDeferredStringCharCodeAt(instr_); }
+    virtual LInstruction* instr() { return instr_; }
    private:
     LStringCharCodeAt* instr_;
   };
@@ -3575,6 +3625,7 @@ void LCodeGen::DoStringCharFromCode(LStringCharFromCode* instr) {
     DeferredStringCharFromCode(LCodeGen* codegen, LStringCharFromCode* instr)
         : LDeferredCode(codegen), instr_(instr) { }
     virtual void Generate() { codegen()->DoDeferredStringCharFromCode(instr_); }
+    virtual LInstruction* instr() { return instr_; }
    private:
     LStringCharFromCode* instr_;
   };
@@ -3646,6 +3697,7 @@ void LCodeGen::DoNumberTagI(LNumberTagI* instr) {
     DeferredNumberTagI(LCodeGen* codegen, LNumberTagI* instr)
         : LDeferredCode(codegen), instr_(instr) { }
     virtual void Generate() { codegen()->DoDeferredNumberTagI(instr_); }
+    virtual LInstruction* instr() { return instr_; }
    private:
     LNumberTagI* instr_;
   };
@@ -3711,6 +3763,7 @@ void LCodeGen::DoNumberTagD(LNumberTagD* instr) {
     DeferredNumberTagD(LCodeGen* codegen, LNumberTagD* instr)
         : LDeferredCode(codegen), instr_(instr) { }
     virtual void Generate() { codegen()->DoDeferredNumberTagD(instr_); }
+    virtual LInstruction* instr() { return instr_; }
    private:
     LNumberTagD* instr_;
   };
@@ -3819,16 +3872,6 @@ void LCodeGen::EmitNumberUntagD(Register input_reg,
 }
 
 
-class DeferredTaggedToI: public LDeferredCode {
- public:
-  DeferredTaggedToI(LCodeGen* codegen, LTaggedToI* instr)
-      : LDeferredCode(codegen), instr_(instr) { }
-  virtual void Generate() { codegen()->DoDeferredTaggedToI(instr_); }
- private:
-  LTaggedToI* instr_;
-};
-
-
 void LCodeGen::DoDeferredTaggedToI(LTaggedToI* instr) {
   Register input_reg = ToRegister(instr->InputAt(0));
   Register scratch1 = scratch0();
@@ -3911,6 +3954,16 @@ void LCodeGen::DoDeferredTaggedToI(LTaggedToI* instr) {
 
 
 void LCodeGen::DoTaggedToI(LTaggedToI* instr) {
+  class DeferredTaggedToI: public LDeferredCode {
+   public:
+    DeferredTaggedToI(LCodeGen* codegen, LTaggedToI* instr)
+        : LDeferredCode(codegen), instr_(instr) { }
+    virtual void Generate() { codegen()->DoDeferredTaggedToI(instr_); }
+    virtual LInstruction* instr() { return instr_; }
+   private:
+    LTaggedToI* instr_;
+  };
+
   LOperand* input = instr->InputAt(0);
   ASSERT(input->IsRegister());
   ASSERT(input->Equals(instr->result()));
@@ -4343,10 +4396,12 @@ Condition LCodeGen::EmitTypeofIs(Label* true_label,
     final_branch_condition = ne;
 
   } else if (type_name->Equals(heap()->function_symbol())) {
+    STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
     __ JumpIfSmi(input, false_label);
-    __ CompareObjectType(input, input, scratch,
-                         FIRST_CALLABLE_SPEC_OBJECT_TYPE);
-    final_branch_condition = ge;
+    __ CompareObjectType(input, scratch, input, JS_FUNCTION_TYPE);
+    __ b(eq, true_label);
+    __ cmp(input, Operand(JS_FUNCTION_PROXY_TYPE));
+    final_branch_condition = eq;
 
   } else if (type_name->Equals(heap()->object_symbol())) {
     __ JumpIfSmi(input, false_label);
@@ -4468,6 +4523,7 @@ void LCodeGen::DoStackCheck(LStackCheck* instr) {
     DeferredStackCheck(LCodeGen* codegen, LStackCheck* instr)
         : LDeferredCode(codegen), instr_(instr) { }
     virtual void Generate() { codegen()->DoDeferredStackCheck(instr_); }
+    virtual LInstruction* instr() { return instr_; }
    private:
     LStackCheck* instr_;
   };
diff --git a/deps/v8/src/arm/lithium-codegen-arm.h b/deps/v8/src/arm/lithium-codegen-arm.h
index ead848903..711e4595e 100644
--- a/deps/v8/src/arm/lithium-codegen-arm.h
+++ b/deps/v8/src/arm/lithium-codegen-arm.h
@@ -376,16 +376,20 @@ class LCodeGen BASE_EMBEDDED {
 class LDeferredCode: public ZoneObject {
  public:
   explicit LDeferredCode(LCodeGen* codegen)
-      : codegen_(codegen), external_exit_(NULL) {
+      : codegen_(codegen),
+        external_exit_(NULL),
+        instruction_index_(codegen->current_instruction_) {
     codegen->AddDeferredCode(this);
   }
 
   virtual ~LDeferredCode() { }
   virtual void Generate() = 0;
+  virtual LInstruction* instr() = 0;
 
   void SetExit(Label *exit) { external_exit_ = exit; }
   Label* entry() { return &entry_; }
   Label* exit() { return external_exit_ != NULL ? external_exit_ : &exit_; }
+  int instruction_index() const { return instruction_index_; }
 
  protected:
   LCodeGen* codegen() const { return codegen_; }
@@ -396,6 +400,7 @@ class LDeferredCode: public ZoneObject {
   Label entry_;
   Label exit_;
   Label* external_exit_;
+  int instruction_index_;
 };
 
 } }  // namespace v8::internal
diff --git a/deps/v8/src/arm/macro-assembler-arm.cc b/deps/v8/src/arm/macro-assembler-arm.cc
index f37f31021..918f9ebe0 100644
--- a/deps/v8/src/arm/macro-assembler-arm.cc
+++ b/deps/v8/src/arm/macro-assembler-arm.cc
@@ -42,7 +42,8 @@ namespace internal {
 MacroAssembler::MacroAssembler(Isolate* arg_isolate, void* buffer, int size)
     : Assembler(arg_isolate, buffer, size),
       generating_stub_(false),
-      allow_stub_calls_(true) {
+      allow_stub_calls_(true),
+      has_frame_(false) {
   if (isolate() != NULL) {
     code_object_ = Handle<Object>(isolate()->heap()->undefined_value(),
                                   isolate());
@@ -406,32 +407,6 @@ void MacroAssembler::StoreRoot(Register source,
 }
 
 
-void MacroAssembler::RecordWriteHelper(Register object,
-                                       Register address,
-                                       Register scratch) {
-  if (emit_debug_code()) {
-    // Check that the object is not in new space.
-    Label not_in_new_space;
-    InNewSpace(object, scratch, ne, &not_in_new_space);
-    Abort("new-space object passed to RecordWriteHelper");
-    bind(&not_in_new_space);
-  }
-
-  // Calculate page address.
-  Bfc(object, 0, kPageSizeBits);
-
-  // Calculate region number.
-  Ubfx(address, address, Page::kRegionSizeLog2,
-       kPageSizeBits - Page::kRegionSizeLog2);
-
-  // Mark region dirty.
-  ldr(scratch, MemOperand(object, Page::kDirtyFlagOffset));
-  mov(ip, Operand(1));
-  orr(scratch, scratch, Operand(ip, LSL, address));
-  str(scratch, MemOperand(object, Page::kDirtyFlagOffset));
-}
-
-
 void MacroAssembler::InNewSpace(Register object,
                                 Register scratch,
                                 Condition cond,
@@ -443,38 +418,52 @@ void MacroAssembler::InNewSpace(Register object,
 }
 
 
-// Will clobber 4 registers: object, offset, scratch, ip.  The
-// register 'object' contains a heap object pointer.  The heap object
-// tag is shifted away.
-void MacroAssembler::RecordWrite(Register object,
-                                 Operand offset,
-                                 Register scratch0,
-                                 Register scratch1) {
-  // The compiled code assumes that record write doesn't change the
-  // context register, so we check that none of the clobbered
-  // registers are cp.
-  ASSERT(!object.is(cp) && !scratch0.is(cp) && !scratch1.is(cp));
-
+void MacroAssembler::RecordWriteField(
+    Register object,
+    int offset,
+    Register value,
+    Register dst,
+    LinkRegisterStatus lr_status,
+    SaveFPRegsMode save_fp,
+    RememberedSetAction remembered_set_action,
+    SmiCheck smi_check) {
+  // First, check if a write barrier is even needed. The tests below
+  // catch stores of Smis.
   Label done;
 
-  // First, test that the object is not in the new space.  We cannot set
-  // region marks for new space pages.
-  InNewSpace(object, scratch0, eq, &done);
+  // Skip barrier if writing a smi.
+  if (smi_check == INLINE_SMI_CHECK) {
+    JumpIfSmi(value, &done);
+  }
 
-  // Add offset into the object.
-  add(scratch0, object, offset);
+  // Although the object register is tagged, the offset is relative to the start
+  // of the object, so so offset must be a multiple of kPointerSize.
+  ASSERT(IsAligned(offset, kPointerSize));
 
-  // Record the actual write.
-  RecordWriteHelper(object, scratch0, scratch1);
+  add(dst, object, Operand(offset - kHeapObjectTag));
+  if (emit_debug_code()) {
+    Label ok;
+    tst(dst, Operand((1 << kPointerSizeLog2) - 1));
+    b(eq, &ok);
+    stop("Unaligned cell in write barrier");
+    bind(&ok);
+  }
+
+  RecordWrite(object,
+              dst,
+              value,
+              lr_status,
+              save_fp,
+              remembered_set_action,
+              OMIT_SMI_CHECK);
 
   bind(&done);
 
-  // Clobber all input registers when running with the debug-code flag
+  // Clobber clobbered input registers when running with the debug-code flag
   // turned on to provoke errors.
   if (emit_debug_code()) {
-    mov(object, Operand(BitCast<int32_t>(kZapValue)));
-    mov(scratch0, Operand(BitCast<int32_t>(kZapValue)));
-    mov(scratch1, Operand(BitCast<int32_t>(kZapValue)));
+    mov(value, Operand(BitCast<int32_t>(kZapValue + 4)));
+    mov(dst, Operand(BitCast<int32_t>(kZapValue + 8)));
   }
 }
 
@@ -484,29 +473,94 @@ void MacroAssembler::RecordWrite(Register object,
 // tag is shifted away.
 void MacroAssembler::RecordWrite(Register object,
                                  Register address,
-                                 Register scratch) {
+                                 Register value,
+                                 LinkRegisterStatus lr_status,
+                                 SaveFPRegsMode fp_mode,
+                                 RememberedSetAction remembered_set_action,
+                                 SmiCheck smi_check) {
   // The compiled code assumes that record write doesn't change the
   // context register, so we check that none of the clobbered
   // registers are cp.
-  ASSERT(!object.is(cp) && !address.is(cp) && !scratch.is(cp));
+  ASSERT(!address.is(cp) && !value.is(cp));
 
   Label done;
 
-  // First, test that the object is not in the new space.  We cannot set
-  // region marks for new space pages.
-  InNewSpace(object, scratch, eq, &done);
+  if (smi_check == INLINE_SMI_CHECK) {
+    ASSERT_EQ(0, kSmiTag);
+    tst(value, Operand(kSmiTagMask));
+    b(eq, &done);
+  }
+
+  CheckPageFlag(value,
+                value,  // Used as scratch.
+                MemoryChunk::kPointersToHereAreInterestingMask,
+                eq,
+                &done);
+  CheckPageFlag(object,
+                value,  // Used as scratch.
+                MemoryChunk::kPointersFromHereAreInterestingMask,
+                eq,
+                &done);
 
   // Record the actual write.
-  RecordWriteHelper(object, address, scratch);
+  if (lr_status == kLRHasNotBeenSaved) {
+    push(lr);
+  }
+  RecordWriteStub stub(object, value, address, remembered_set_action, fp_mode);
+  CallStub(&stub);
+  if (lr_status == kLRHasNotBeenSaved) {
+    pop(lr);
+  }
 
   bind(&done);
 
-  // Clobber all input registers when running with the debug-code flag
+  // Clobber clobbered registers when running with the debug-code flag
   // turned on to provoke errors.
   if (emit_debug_code()) {
-    mov(object, Operand(BitCast<int32_t>(kZapValue)));
-    mov(address, Operand(BitCast<int32_t>(kZapValue)));
-    mov(scratch, Operand(BitCast<int32_t>(kZapValue)));
+    mov(address, Operand(BitCast<int32_t>(kZapValue + 12)));
+    mov(value, Operand(BitCast<int32_t>(kZapValue + 16)));
+  }
+}
+
+
+void MacroAssembler::RememberedSetHelper(Register object,  // For debug tests.
+                                         Register address,
+                                         Register scratch,
+                                         SaveFPRegsMode fp_mode,
+                                         RememberedSetFinalAction and_then) {
+  Label done;
+  if (FLAG_debug_code) {
+    Label ok;
+    JumpIfNotInNewSpace(object, scratch, &ok);
+    stop("Remembered set pointer is in new space");
+    bind(&ok);
+  }
+  // Load store buffer top.
+  ExternalReference store_buffer =
+      ExternalReference::store_buffer_top(isolate());
+  mov(ip, Operand(store_buffer));
+  ldr(scratch, MemOperand(ip));
+  // Store pointer to buffer and increment buffer top.
+  str(address, MemOperand(scratch, kPointerSize, PostIndex));
+  // Write back new top of buffer.
+  str(scratch, MemOperand(ip));
+  // Call stub on end of buffer.
+  // Check for end of buffer.
+  tst(scratch, Operand(StoreBuffer::kStoreBufferOverflowBit));
+  if (and_then == kFallThroughAtEnd) {
+    b(eq, &done);
+  } else {
+    ASSERT(and_then == kReturnAtEnd);
+    Ret(eq);
+  }
+  push(lr);
+  StoreBufferOverflowStub store_buffer_overflow =
+      StoreBufferOverflowStub(fp_mode);
+  CallStub(&store_buffer_overflow);
+  pop(lr);
+  bind(&done);
+  if (and_then == kReturnAtEnd) {
+    Ret();
   }
 }
 
@@ -961,6 +1015,9 @@ void MacroAssembler::InvokeCode(Register code,
                                 InvokeFlag flag,
                                 const CallWrapper& call_wrapper,
                                 CallKind call_kind) {
+  // You can't call a function without a valid frame.
+  ASSERT(flag == JUMP_FUNCTION || has_frame());
+
   Label done;
 
   InvokePrologue(expected, actual, Handle<Code>::null(), code, &done, flag,
@@ -988,6 +1045,9 @@ void MacroAssembler::InvokeCode(Handle<Code> code,
                                 RelocInfo::Mode rmode,
                                 InvokeFlag flag,
                                 CallKind call_kind) {
+  // You can't call a function without a valid frame.
+  ASSERT(flag == JUMP_FUNCTION || has_frame());
+
   Label done;
 
   InvokePrologue(expected, actual, code, no_reg, &done, flag,
@@ -1011,6 +1071,9 @@ void MacroAssembler::InvokeFunction(Register fun,
                                     InvokeFlag flag,
                                     const CallWrapper& call_wrapper,
                                     CallKind call_kind) {
+  // You can't call a function without a valid frame.
+  ASSERT(flag == JUMP_FUNCTION || has_frame());
+
   // Contract with called JS functions requires that function is passed in r1.
   ASSERT(fun.is(r1));
 
@@ -1035,6 +1098,9 @@ void MacroAssembler::InvokeFunction(JSFunction* function,
                                     const ParameterCount& actual,
                                     InvokeFlag flag,
                                     CallKind call_kind) {
+  // You can't call a function without a valid frame.
+  ASSERT(flag == JUMP_FUNCTION || has_frame());
+
   ASSERT(function->is_compiled());
 
   // Get the function and setup the context.
@@ -1090,10 +1156,10 @@ void MacroAssembler::IsObjectJSStringType(Register object,
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
 void MacroAssembler::DebugBreak() {
-  ASSERT(allow_stub_calls());
   mov(r0, Operand(0, RelocInfo::NONE));
   mov(r1, Operand(ExternalReference(Runtime::kDebugBreak, isolate())));
   CEntryStub ces(1);
+  ASSERT(AllowThisStubCall(&ces));
   Call(ces.GetCode(), RelocInfo::DEBUG_BREAK);
 }
 #endif
@@ -1793,13 +1859,127 @@ void MacroAssembler::CompareRoot(Register obj,
 void MacroAssembler::CheckFastElements(Register map,
                                        Register scratch,
                                        Label* fail) {
-  STATIC_ASSERT(FAST_ELEMENTS == 0);
+  STATIC_ASSERT(FAST_SMI_ONLY_ELEMENTS == 0);
+  STATIC_ASSERT(FAST_ELEMENTS == 1);
   ldrb(scratch, FieldMemOperand(map, Map::kBitField2Offset));
   cmp(scratch, Operand(Map::kMaximumBitField2FastElementValue));
   b(hi, fail);
 }
 
 
+void MacroAssembler::CheckFastObjectElements(Register map,
+                                             Register scratch,
+                                             Label* fail) {
+  STATIC_ASSERT(FAST_SMI_ONLY_ELEMENTS == 0);
+  STATIC_ASSERT(FAST_ELEMENTS == 1);
+  ldrb(scratch, FieldMemOperand(map, Map::kBitField2Offset));
+  cmp(scratch, Operand(Map::kMaximumBitField2FastSmiOnlyElementValue));
+  b(ls, fail);
+  cmp(scratch, Operand(Map::kMaximumBitField2FastElementValue));
+  b(hi, fail);
+}
+
+
+void MacroAssembler::CheckFastSmiOnlyElements(Register map,
+                                              Register scratch,
+                                              Label* fail) {
+  STATIC_ASSERT(FAST_SMI_ONLY_ELEMENTS == 0);
+  ldrb(scratch, FieldMemOperand(map, Map::kBitField2Offset));
+  cmp(scratch, Operand(Map::kMaximumBitField2FastSmiOnlyElementValue));
+  b(hi, fail);
+}
+
+
+void MacroAssembler::StoreNumberToDoubleElements(Register value_reg,
+                                                 Register key_reg,
+                                                 Register receiver_reg,
+                                                 Register elements_reg,
+                                                 Register scratch1,
+                                                 Register scratch2,
+                                                 Register scratch3,
+                                                 Register scratch4,
+                                                 Label* fail) {
+  Label smi_value, maybe_nan, have_double_value, is_nan, done;
+  Register mantissa_reg = scratch2;
+  Register exponent_reg = scratch3;
+
+  // Handle smi values specially.
+  JumpIfSmi(value_reg, &smi_value);
+
+  // Ensure that the object is a heap number
+  CheckMap(value_reg,
+           scratch1,
+           isolate()->factory()->heap_number_map(),
+           fail,
+           DONT_DO_SMI_CHECK);
+
+  // Check for nan: all NaN values have a value greater (signed) than 0x7ff00000
+  // in the exponent.
+  mov(scratch1, Operand(kNaNOrInfinityLowerBoundUpper32));
+  ldr(exponent_reg, FieldMemOperand(value_reg, HeapNumber::kExponentOffset));
+  cmp(exponent_reg, scratch1);
+  b(ge, &maybe_nan);
+
+  ldr(mantissa_reg, FieldMemOperand(value_reg, HeapNumber::kMantissaOffset));
+
+  bind(&have_double_value);
+  add(scratch1, elements_reg,
+      Operand(key_reg, LSL, kDoubleSizeLog2 - kSmiTagSize));
+  str(mantissa_reg, FieldMemOperand(scratch1, FixedDoubleArray::kHeaderSize));
+  uint32_t offset = FixedDoubleArray::kHeaderSize + sizeof(kHoleNanLower32);
+  str(exponent_reg, FieldMemOperand(scratch1, offset));
+  jmp(&done);
+
+  bind(&maybe_nan);
+  // Could be NaN or Infinity. If fraction is not zero, it's NaN, otherwise
+  // it's an Infinity, and the non-NaN code path applies.
+  b(gt, &is_nan);
+  ldr(mantissa_reg, FieldMemOperand(value_reg, HeapNumber::kMantissaOffset));
+  cmp(mantissa_reg, Operand(0));
+  b(eq, &have_double_value);
+  bind(&is_nan);
+  // Load canonical NaN for storing into the double array.
+  uint64_t nan_int64 = BitCast<uint64_t>(
+      FixedDoubleArray::canonical_not_the_hole_nan_as_double());
+  mov(mantissa_reg, Operand(static_cast<uint32_t>(nan_int64)));
+  mov(exponent_reg, Operand(static_cast<uint32_t>(nan_int64 >> 32)));
+  jmp(&have_double_value);
+
+  bind(&smi_value);
+  add(scratch1, elements_reg,
+      Operand(FixedDoubleArray::kHeaderSize - kHeapObjectTag));
+  add(scratch1, scratch1,
+      Operand(key_reg, LSL, kDoubleSizeLog2 - kSmiTagSize));
+  // scratch1 is now effective address of the double element
+
+  FloatingPointHelper::Destination destination;
+  if (CpuFeatures::IsSupported(VFP3)) {
+    destination = FloatingPointHelper::kVFPRegisters;
+  } else {
+    destination = FloatingPointHelper::kCoreRegisters;
+  }
+
+  Register untagged_value = receiver_reg;
+  SmiUntag(untagged_value, value_reg);
+  FloatingPointHelper::ConvertIntToDouble(this,
+                                          untagged_value,
+                                          destination,
+                                          d0,
+                                          mantissa_reg,
+                                          exponent_reg,
+                                          scratch4,
+                                          s2);
+  if (destination == FloatingPointHelper::kVFPRegisters) {
+    CpuFeatures::Scope scope(VFP3);
+    vstr(d0, scratch1, 0);
+  } else {
+    str(mantissa_reg, MemOperand(scratch1, 0));
+    str(exponent_reg, MemOperand(scratch1, Register::kSizeInBytes));
+  }
+  bind(&done);
+}
+
+
 void MacroAssembler::CheckMap(Register obj,
                               Register scratch,
                               Handle<Map> map,
@@ -1895,13 +2075,13 @@ void MacroAssembler::TryGetFunctionPrototype(Register function,
 
 
 void MacroAssembler::CallStub(CodeStub* stub, Condition cond) {
-  ASSERT(allow_stub_calls());  // Stub calls are not allowed in some stubs.
+  ASSERT(AllowThisStubCall(stub));  // Stub calls are not allowed in some stubs.
   Call(stub->GetCode(), RelocInfo::CODE_TARGET, kNoASTId, cond);
 }
 
 
 MaybeObject* MacroAssembler::TryCallStub(CodeStub* stub, Condition cond) {
-  ASSERT(allow_stub_calls());  // Stub calls are not allowed in some stubs.
+  ASSERT(AllowThisStubCall(stub));  // Stub calls are not allowed in some stubs.
   Object* result;
   { MaybeObject* maybe_result = stub->TryGetCode();
     if (!maybe_result->ToObject(&result)) return maybe_result;
@@ -1913,13 +2093,12 @@ MaybeObject* MacroAssembler::TryCallStub(CodeStub* stub, Condition cond) {
 
 
 void MacroAssembler::TailCallStub(CodeStub* stub, Condition cond) {
-  ASSERT(allow_stub_calls());  // Stub calls are not allowed in some stubs.
+  ASSERT(allow_stub_calls_ || stub->CompilingCallsToThisStubIsGCSafe());
   Jump(stub->GetCode(), RelocInfo::CODE_TARGET, cond);
 }
 
 
 MaybeObject* MacroAssembler::TryTailCallStub(CodeStub* stub, Condition cond) {
-  ASSERT(allow_stub_calls());  // Stub calls are not allowed in some stubs.
   Object* result;
   { MaybeObject* maybe_result = stub->TryGetCode();
     if (!maybe_result->ToObject(&result)) return maybe_result;
@@ -2022,6 +2201,12 @@ MaybeObject* MacroAssembler::TryCallApiFunctionAndReturn(
 }
 
 
+bool MacroAssembler::AllowThisStubCall(CodeStub* stub) {
+  if (!has_frame_ && stub->SometimesSetsUpAFrame()) return false;
+  return allow_stub_calls_ || stub->CompilingCallsToThisStubIsGCSafe();
+}
+
+
 void MacroAssembler::IllegalOperation(int num_arguments) {
   if (num_arguments > 0) {
     add(sp, sp, Operand(num_arguments * kPointerSize));
@@ -2417,8 +2602,7 @@ void MacroAssembler::CallRuntimeSaveDoubles(Runtime::FunctionId id) {
   const Runtime::Function* function = Runtime::FunctionForId(id);
   mov(r0, Operand(function->nargs));
   mov(r1, Operand(ExternalReference(function, isolate())));
-  CEntryStub stub(1);
-  stub.SaveDoubles();
+  CEntryStub stub(1, kSaveFPRegs);
   CallStub(&stub);
 }
 
@@ -2491,6 +2675,9 @@ MaybeObject* MacroAssembler::TryJumpToExternalReference(
 void MacroAssembler::InvokeBuiltin(Builtins::JavaScript id,
                                    InvokeFlag flag,
                                    const CallWrapper& call_wrapper) {
+  // You can't call a builtin without a valid frame.
+  ASSERT(flag == JUMP_FUNCTION || has_frame());
+
   GetBuiltinEntry(r2, id);
   if (flag == CALL_FUNCTION) {
     call_wrapper.BeforeCall(CallSize(r2));
@@ -2622,14 +2809,20 @@ void MacroAssembler::Abort(const char* msg) {
     RecordComment(msg);
   }
 #endif
-  // Disable stub call restrictions to always allow calls to abort.
-  AllowStubCallsScope allow_scope(this, true);
 
   mov(r0, Operand(p0));
   push(r0);
   mov(r0, Operand(Smi::FromInt(p1 - p0)));
   push(r0);
-  CallRuntime(Runtime::kAbort, 2);
+  // Disable stub call restrictions to always allow calls to abort.
+  if (!has_frame_) {
+    // We don't actually want to generate a pile of code for this, so just
+    // claim there is a stack frame, without generating one.
+    FrameScope scope(this, StackFrame::NONE);
+    CallRuntime(Runtime::kAbort, 2);
+  } else {
+    CallRuntime(Runtime::kAbort, 2);
+  }
   // will not return here
   if (is_const_pool_blocked()) {
     // If the calling code cares about the exact number of
@@ -2930,6 +3123,19 @@ void MacroAssembler::CopyBytes(Register src,
 }
 
 
+void MacroAssembler::InitializeFieldsWithFiller(Register start_offset,
+                                                Register end_offset,
+                                                Register filler) {
+  Label loop, entry;
+  b(&entry);
+  bind(&loop);
+  str(filler, MemOperand(start_offset, kPointerSize, PostIndex));
+  bind(&entry);
+  cmp(start_offset, end_offset);
+  b(lt, &loop);
+}
+
+
 void MacroAssembler::CountLeadingZeros(Register zeros,   // Answer.
                                        Register source,  // Input.
                                        Register scratch) {
@@ -3089,23 +3295,15 @@ void MacroAssembler::SetCallCDoubleArguments(DoubleRegister dreg,
 void MacroAssembler::CallCFunction(ExternalReference function,
                                    int num_reg_arguments,
                                    int num_double_arguments) {
-  CallCFunctionHelper(no_reg,
-                      function,
-                      ip,
-                      num_reg_arguments,
-                      num_double_arguments);
+  mov(ip, Operand(function));
+  CallCFunctionHelper(ip, num_reg_arguments, num_double_arguments);
 }
 
 
 void MacroAssembler::CallCFunction(Register function,
-                                     Register scratch,
-                                     int num_reg_arguments,
-                                     int num_double_arguments) {
-  CallCFunctionHelper(function,
-                      ExternalReference::the_hole_value_location(isolate()),
-                      scratch,
-                      num_reg_arguments,
-                      num_double_arguments);
+                                   int num_reg_arguments,
+                                   int num_double_arguments) {
+  CallCFunctionHelper(function, num_reg_arguments, num_double_arguments);
 }
 
 
@@ -3116,17 +3314,15 @@ void MacroAssembler::CallCFunction(ExternalReference function,
 
 
 void MacroAssembler::CallCFunction(Register function,
-                                   Register scratch,
                                    int num_arguments) {
-  CallCFunction(function, scratch, num_arguments, 0);
+  CallCFunction(function, num_arguments, 0);
 }
 
 
 void MacroAssembler::CallCFunctionHelper(Register function,
-                                         ExternalReference function_reference,
-                                         Register scratch,
                                          int num_reg_arguments,
                                          int num_double_arguments) {
+  ASSERT(has_frame());
   // Make sure that the stack is aligned before calling a C function unless
   // running in the simulator. The simulator has its own alignment check which
   // provides more information.
@@ -3150,10 +3346,6 @@ void MacroAssembler::CallCFunctionHelper(Register function,
   // Just call directly. The function called cannot cause a GC, or
   // allow preemption, so the return address in the link register
   // stays correct.
-  if (function.is(no_reg)) {
-    mov(scratch, Operand(function_reference));
-    function = scratch;
-  }
   Call(function);
   int stack_passed_arguments = CalculateStackPassedWords(
       num_reg_arguments, num_double_arguments);
@@ -3185,6 +3377,185 @@ void MacroAssembler::GetRelocatedValueLocation(Register ldr_location,
 }
 
 
+void MacroAssembler::CheckPageFlag(
+    Register object,
+    Register scratch,
+    int mask,
+    Condition cc,
+    Label* condition_met) {
+  and_(scratch, object, Operand(~Page::kPageAlignmentMask));
+  ldr(scratch, MemOperand(scratch, MemoryChunk::kFlagsOffset));
+  tst(scratch, Operand(mask));
+  b(cc, condition_met);
+}
+
+
+void MacroAssembler::JumpIfBlack(Register object,
+                                 Register scratch0,
+                                 Register scratch1,
+                                 Label* on_black) {
+  HasColor(object, scratch0, scratch1, on_black, 1, 0);  // kBlackBitPattern.
+  ASSERT(strcmp(Marking::kBlackBitPattern, "10") == 0);
+}
+
+
+void MacroAssembler::HasColor(Register object,
+                              Register bitmap_scratch,
+                              Register mask_scratch,
+                              Label* has_color,
+                              int first_bit,
+                              int second_bit) {
+  ASSERT(!AreAliased(object, bitmap_scratch, mask_scratch, no_reg));
+
+  GetMarkBits(object, bitmap_scratch, mask_scratch);
+
+  Label other_color, word_boundary;
+  ldr(ip, MemOperand(bitmap_scratch, MemoryChunk::kHeaderSize));
+  tst(ip, Operand(mask_scratch));
+  b(first_bit == 1 ? eq : ne, &other_color);
+  // Shift left 1 by adding.
+  add(mask_scratch, mask_scratch, Operand(mask_scratch), SetCC);
+  b(eq, &word_boundary);
+  tst(ip, Operand(mask_scratch));
+  b(second_bit == 1 ? ne : eq, has_color);
+  jmp(&other_color);
+
+  bind(&word_boundary);
+  ldr(ip, MemOperand(bitmap_scratch, MemoryChunk::kHeaderSize + kPointerSize));
+  tst(ip, Operand(1));
+  b(second_bit == 1 ? ne : eq, has_color);
+  bind(&other_color);
+}
+
+
+// Detect some, but not all, common pointer-free objects.  This is used by the
+// incremental write barrier which doesn't care about oddballs (they are always
+// marked black immediately so this code is not hit).
+void MacroAssembler::JumpIfDataObject(Register value,
+                                      Register scratch,
+                                      Label* not_data_object) {
+  Label is_data_object;
+  ldr(scratch, FieldMemOperand(value, HeapObject::kMapOffset));
+  CompareRoot(scratch, Heap::kHeapNumberMapRootIndex);
+  b(eq, &is_data_object);
+  ASSERT(kIsIndirectStringTag == 1 && kIsIndirectStringMask == 1);
+  ASSERT(kNotStringTag == 0x80 && kIsNotStringMask == 0x80);
+  // If it's a string and it's not a cons string then it's an object containing
+  // no GC pointers.
+  ldrb(scratch, FieldMemOperand(scratch, Map::kInstanceTypeOffset));
+  tst(scratch, Operand(kIsIndirectStringMask | kIsNotStringMask));
+  b(ne, not_data_object);
+  bind(&is_data_object);
+}
+
+
+void MacroAssembler::GetMarkBits(Register addr_reg,
+                                 Register bitmap_reg,
+                                 Register mask_reg) {
+  ASSERT(!AreAliased(addr_reg, bitmap_reg, mask_reg, no_reg));
+  and_(bitmap_reg, addr_reg, Operand(~Page::kPageAlignmentMask));
+  Ubfx(mask_reg, addr_reg, kPointerSizeLog2, Bitmap::kBitsPerCellLog2);
+  const int kLowBits = kPointerSizeLog2 + Bitmap::kBitsPerCellLog2;
+  Ubfx(ip, addr_reg, kLowBits, kPageSizeBits - kLowBits);
+  add(bitmap_reg, bitmap_reg, Operand(ip, LSL, kPointerSizeLog2));
+  mov(ip, Operand(1));
+  mov(mask_reg, Operand(ip, LSL, mask_reg));
+}
+
+
+void MacroAssembler::EnsureNotWhite(
+    Register value,
+    Register bitmap_scratch,
+    Register mask_scratch,
+    Register load_scratch,
+    Label* value_is_white_and_not_data) {
+  ASSERT(!AreAliased(value, bitmap_scratch, mask_scratch, ip));
+  GetMarkBits(value, bitmap_scratch, mask_scratch);
+
+  // If the value is black or grey we don't need to do anything.
+  ASSERT(strcmp(Marking::kWhiteBitPattern, "00") == 0);
+  ASSERT(strcmp(Marking::kBlackBitPattern, "10") == 0);
+  ASSERT(strcmp(Marking::kGreyBitPattern, "11") == 0);
+  ASSERT(strcmp(Marking::kImpossibleBitPattern, "01") == 0);
+
+  Label done;
+
+  // Since both black and grey have a 1 in the first position and white does
+  // not have a 1 there we only need to check one bit.
+  ldr(load_scratch, MemOperand(bitmap_scratch, MemoryChunk::kHeaderSize));
+  tst(mask_scratch, load_scratch);
+  b(ne, &done);
+
+  if (FLAG_debug_code) {
+    // Check for impossible bit pattern.
+    Label ok;
+    // LSL may overflow, making the check conservative.
+    tst(load_scratch, Operand(mask_scratch, LSL, 1));
+    b(eq, &ok);
+    stop("Impossible marking bit pattern");
+    bind(&ok);
+  }
+
+  // Value is white.  We check whether it is data that doesn't need scanning.
+  // Currently only checks for HeapNumber and non-cons strings.
+  Register map = load_scratch;  // Holds map while checking type.
+  Register length = load_scratch;  // Holds length of object after testing type.
+  Label is_data_object;
+
+  // Check for heap-number
+  ldr(map, FieldMemOperand(value, HeapObject::kMapOffset));
+  CompareRoot(map, Heap::kHeapNumberMapRootIndex);
+  mov(length, Operand(HeapNumber::kSize), LeaveCC, eq);
+  b(eq, &is_data_object);
+
+  // Check for strings.
+  ASSERT(kIsIndirectStringTag == 1 && kIsIndirectStringMask == 1);
+  ASSERT(kNotStringTag == 0x80 && kIsNotStringMask == 0x80);
+  // If it's a string and it's not a cons string then it's an object containing
+  // no GC pointers.
+  Register instance_type = load_scratch;
+  ldrb(instance_type, FieldMemOperand(map, Map::kInstanceTypeOffset));
+  tst(instance_type, Operand(kIsIndirectStringMask | kIsNotStringMask));
+  b(ne, value_is_white_and_not_data);
+  // It's a non-indirect (non-cons and non-slice) string.
+  // If it's external, the length is just ExternalString::kSize.
+  // Otherwise it's String::kHeaderSize + string->length() * (1 or 2).
+  // External strings are the only ones with the kExternalStringTag bit
+  // set.
+  ASSERT_EQ(0, kSeqStringTag & kExternalStringTag);
+  ASSERT_EQ(0, kConsStringTag & kExternalStringTag);
+  tst(instance_type, Operand(kExternalStringTag));
+  mov(length, Operand(ExternalString::kSize), LeaveCC, ne);
+  b(ne, &is_data_object);
+
+  // Sequential string, either ASCII or UC16.
+  // For ASCII (char-size of 1) we shift the smi tag away to get the length.
+  // For UC16 (char-size of 2) we just leave the smi tag in place, thereby
+  // getting the length multiplied by 2.
+  ASSERT(kAsciiStringTag == 4 && kStringEncodingMask == 4);
+  ASSERT(kSmiTag == 0 && kSmiTagSize == 1);
+  ldr(ip, FieldMemOperand(value, String::kLengthOffset));
+  tst(instance_type, Operand(kStringEncodingMask));
+  mov(ip, Operand(ip, LSR, 1), LeaveCC, ne);
+  add(length, ip, Operand(SeqString::kHeaderSize + kObjectAlignmentMask));
+  and_(length, length, Operand(~kObjectAlignmentMask));
+
+  bind(&is_data_object);
+  // Value is a data object, and it is white.  Mark it black.  Since we know
+  // that the object is white we can make it black by flipping one bit.
+  ldr(ip, MemOperand(bitmap_scratch, MemoryChunk::kHeaderSize));
+  orr(ip, ip, Operand(mask_scratch));
+  str(ip, MemOperand(bitmap_scratch, MemoryChunk::kHeaderSize));
+
+  and_(bitmap_scratch, bitmap_scratch, Operand(~Page::kPageAlignmentMask));
+  ldr(ip, MemOperand(bitmap_scratch, MemoryChunk::kLiveBytesOffset));
+  add(ip, ip, Operand(length));
+  str(ip, MemOperand(bitmap_scratch, MemoryChunk::kLiveBytesOffset));
+
+  bind(&done);
+}
+
+
 void MacroAssembler::ClampUint8(Register output_reg, Register input_reg) {
   Usat(output_reg, 8, Operand(input_reg));
 }
@@ -3234,6 +3605,17 @@ void MacroAssembler::LoadInstanceDescriptors(Register map,
 }
 
 
+bool AreAliased(Register r1, Register r2, Register r3, Register r4) {
+  if (r1.is(r2)) return true;
+  if (r1.is(r3)) return true;
+  if (r1.is(r4)) return true;
+  if (r2.is(r3)) return true;
+  if (r2.is(r4)) return true;
+  if (r3.is(r4)) return true;
+  return false;
+}
+
+
 CodePatcher::CodePatcher(byte* address, int instructions)
     : address_(address),
       instructions_(instructions),
diff --git a/deps/v8/src/arm/macro-assembler-arm.h b/deps/v8/src/arm/macro-assembler-arm.h
index 6084fde2d..8ee468a91 100644
--- a/deps/v8/src/arm/macro-assembler-arm.h
+++ b/deps/v8/src/arm/macro-assembler-arm.h
@@ -29,6 +29,7 @@
 #define V8_ARM_MACRO_ASSEMBLER_ARM_H_
 
 #include "assembler.h"
+#include "frames.h"
 #include "v8globals.h"
 
 namespace v8 {
@@ -79,6 +80,14 @@ enum ObjectToDoubleFlags {
 };
 
 
+enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
+enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
+enum LinkRegisterStatus { kLRHasNotBeenSaved, kLRHasBeenSaved };
+
+
+bool AreAliased(Register r1, Register r2, Register r3, Register r4);
+
+
 // MacroAssembler implements a collection of frequently used macros.
 class MacroAssembler: public Assembler {
  public:
@@ -157,40 +166,126 @@ class MacroAssembler: public Assembler {
                  Heap::RootListIndex index,
                  Condition cond = al);
 
+  // ---------------------------------------------------------------------------
+  // GC Support
+
+  void IncrementalMarkingRecordWriteHelper(Register object,
+                                           Register value,
+                                           Register address);
+
+  enum RememberedSetFinalAction {
+    kReturnAtEnd,
+    kFallThroughAtEnd
+  };
+
+  // Record in the remembered set the fact that we have a pointer to new space
+  // at the address pointed to by the addr register.  Only works if addr is not
+  // in new space.
+  void RememberedSetHelper(Register object,  // Used for debug code.
+                           Register addr,
+                           Register scratch,
+                           SaveFPRegsMode save_fp,
+                           RememberedSetFinalAction and_then);
+
+  void CheckPageFlag(Register object,
+                     Register scratch,
+                     int mask,
+                     Condition cc,
+                     Label* condition_met);
+
+  // Check if object is in new space.  Jumps if the object is not in new space.
+  // The register scratch can be object itself, but scratch will be clobbered.
+  void JumpIfNotInNewSpace(Register object,
+                           Register scratch,
+                           Label* branch) {
+    InNewSpace(object, scratch, ne, branch);
+  }
 
-  // Check if object is in new space.
-  // scratch can be object itself, but it will be clobbered.
-  void InNewSpace(Register object,
-                  Register scratch,
-                  Condition cond,  // eq for new space, ne otherwise
-                  Label* branch);
-
+  // Check if object is in new space.  Jumps if the object is in new space.
+  // The register scratch can be object itself, but it will be clobbered.
+  void JumpIfInNewSpace(Register object,
+                        Register scratch,
+                        Label* branch) {
+    InNewSpace(object, scratch, eq, branch);
+  }
 
-  // For the page containing |object| mark the region covering [address]
-  // dirty. The object address must be in the first 8K of an allocated page.
-  void RecordWriteHelper(Register object,
-                         Register address,
-                         Register scratch);
+  // Check if an object has a given incremental marking color.
+  void HasColor(Register object,
+                Register scratch0,
+                Register scratch1,
+                Label* has_color,
+                int first_bit,
+                int second_bit);
 
-  // For the page containing |object| mark the region covering
-  // [object+offset] dirty. The object address must be in the first 8K
-  // of an allocated page.  The 'scratch' registers are used in the
-  // implementation and all 3 registers are clobbered by the
-  // operation, as well as the ip register. RecordWrite updates the
-  // write barrier even when storing smis.
-  void RecordWrite(Register object,
-                   Operand offset,
+  void JumpIfBlack(Register object,
                    Register scratch0,
-                   Register scratch1);
+                   Register scratch1,
+                   Label* on_black);
+
+  // Checks the color of an object.  If the object is already grey or black
+  // then we just fall through, since it is already live.  If it is white and
+  // we can determine that it doesn't need to be scanned, then we just mark it
+  // black and fall through.  For the rest we jump to the label so the
+  // incremental marker can fix its assumptions.
+  void EnsureNotWhite(Register object,
+                      Register scratch1,
+                      Register scratch2,
+                      Register scratch3,
+                      Label* object_is_white_and_not_data);
 
-  // For the page containing |object| mark the region covering
-  // [address] dirty. The object address must be in the first 8K of an
-  // allocated page.  All 3 registers are clobbered by the operation,
-  // as well as the ip register. RecordWrite updates the write barrier
-  // even when storing smis.
-  void RecordWrite(Register object,
-                   Register address,
-                   Register scratch);
+  // Detects conservatively whether an object is data-only, ie it does need to
+  // be scanned by the garbage collector.
+  void JumpIfDataObject(Register value,
+                        Register scratch,
+                        Label* not_data_object);
+
+  // Notify the garbage collector that we wrote a pointer into an object.
+  // |object| is the object being stored into, |value| is the object being
+  // stored.  value and scratch registers are clobbered by the operation.
+  // The offset is the offset from the start of the object, not the offset from
+  // the tagged HeapObject pointer.  For use with FieldOperand(reg, off).
+  void RecordWriteField(
+      Register object,
+      int offset,
+      Register value,
+      Register scratch,
+      LinkRegisterStatus lr_status,
+      SaveFPRegsMode save_fp,
+      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
+      SmiCheck smi_check = INLINE_SMI_CHECK);
+
+  // As above, but the offset has the tag presubtracted.  For use with
+  // MemOperand(reg, off).
+  inline void RecordWriteContextSlot(
+      Register context,
+      int offset,
+      Register value,
+      Register scratch,
+      LinkRegisterStatus lr_status,
+      SaveFPRegsMode save_fp,
+      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
+      SmiCheck smi_check = INLINE_SMI_CHECK) {
+    RecordWriteField(context,
+                     offset + kHeapObjectTag,
+                     value,
+                     scratch,
+                     lr_status,
+                     save_fp,
+                     remembered_set_action,
+                     smi_check);
+  }
+
+  // For a given |object| notify the garbage collector that the slot |address|
+  // has been written.  |value| is the object being stored. The value and
+  // address registers are clobbered by the operation.
+  void RecordWrite(
+      Register object,
+      Register address,
+      Register value,
+      LinkRegisterStatus lr_status,
+      SaveFPRegsMode save_fp,
+      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
+      SmiCheck smi_check = INLINE_SMI_CHECK);
 
   // Push a handle.
   void Push(Handle<Object> handle);
@@ -318,16 +413,6 @@ class MacroAssembler: public Assembler {
             const double imm,
             const Condition cond = al);
 
-
-  // ---------------------------------------------------------------------------
-  // Activation frames
-
-  void EnterInternalFrame() { EnterFrame(StackFrame::INTERNAL); }
-  void LeaveInternalFrame() { LeaveFrame(StackFrame::INTERNAL); }
-
-  void EnterConstructFrame() { EnterFrame(StackFrame::CONSTRUCT); }
-  void LeaveConstructFrame() { LeaveFrame(StackFrame::CONSTRUCT); }
-
   // Enter exit frame.
   // stack_space - extra stack space, used for alignment before call to C.
   void EnterExitFrame(bool save_doubles, int stack_space = 0);
@@ -569,6 +654,13 @@ class MacroAssembler: public Assembler {
                  Register length,
                  Register scratch);
 
+  // Initialize fields with filler values.  Fields starting at |start_offset|
+  // not including end_offset are overwritten with the value in |filler|.  At
+  // the end the loop, |start_offset| takes the value of |end_offset|.
+  void InitializeFieldsWithFiller(Register start_offset,
+                                  Register end_offset,
+                                  Register filler);
+
   // ---------------------------------------------------------------------------
   // Support functions.
 
@@ -608,6 +700,31 @@ class MacroAssembler: public Assembler {
                          Register scratch,
                          Label* fail);
 
+  // Check if a map for a JSObject indicates that the object can have both smi
+  // and HeapObject elements.  Jump to the specified label if it does not.
+  void CheckFastObjectElements(Register map,
+                               Register scratch,
+                               Label* fail);
+
+  // Check if a map for a JSObject indicates that the object has fast smi only
+  // elements.  Jump to the specified label if it does not.
+  void CheckFastSmiOnlyElements(Register map,
+                                Register scratch,
+                                Label* fail);
+
+  // Check to see if maybe_number can be stored as a double in
+  // FastDoubleElements. If it can, store it at the index specified by key in
+  // the FastDoubleElements array elements, otherwise jump to fail.
+  void StoreNumberToDoubleElements(Register value_reg,
+                                   Register key_reg,
+                                   Register receiver_reg,
+                                   Register elements_reg,
+                                   Register scratch1,
+                                   Register scratch2,
+                                   Register scratch3,
+                                   Register scratch4,
+                                   Label* fail);
+
   // Check if the map of an object is equal to a specified map (either
   // given directly or as an index into the root list) and branch to
   // label if not. Skip the smi check if not required (object is known
@@ -830,11 +947,11 @@ class MacroAssembler: public Assembler {
   // return address (unless this is somehow accounted for by the called
   // function).
   void CallCFunction(ExternalReference function, int num_arguments);
-  void CallCFunction(Register function, Register scratch, int num_arguments);
+  void CallCFunction(Register function, int num_arguments);
   void CallCFunction(ExternalReference function,
                      int num_reg_arguments,
                      int num_double_arguments);
-  void CallCFunction(Register function, Register scratch,
+  void CallCFunction(Register function,
                      int num_reg_arguments,
                      int num_double_arguments);
 
@@ -902,6 +1019,9 @@ class MacroAssembler: public Assembler {
   bool generating_stub() { return generating_stub_; }
   void set_allow_stub_calls(bool value) { allow_stub_calls_ = value; }
   bool allow_stub_calls() { return allow_stub_calls_; }
+  void set_has_frame(bool value) { has_frame_ = value; }
+  bool has_frame() { return has_frame_; }
+  inline bool AllowThisStubCall(CodeStub* stub);
 
   // EABI variant for double arguments in use.
   bool use_eabi_hardfloat() {
@@ -1048,10 +1168,12 @@ class MacroAssembler: public Assembler {
 
   void LoadInstanceDescriptors(Register map, Register descriptors);
 
+  // Activation support.
+  void EnterFrame(StackFrame::Type type);
+  void LeaveFrame(StackFrame::Type type);
+
  private:
   void CallCFunctionHelper(Register function,
-                           ExternalReference function_reference,
-                           Register scratch,
                            int num_reg_arguments,
                            int num_double_arguments);
 
@@ -1067,16 +1189,25 @@ class MacroAssembler: public Assembler {
                       const CallWrapper& call_wrapper,
                       CallKind call_kind);
 
-  // Activation support.
-  void EnterFrame(StackFrame::Type type);
-  void LeaveFrame(StackFrame::Type type);
-
   void InitializeNewString(Register string,
                            Register length,
                            Heap::RootListIndex map_index,
                            Register scratch1,
                            Register scratch2);
 
+  // Helper for implementing JumpIfNotInNewSpace and JumpIfInNewSpace.
+  void InNewSpace(Register object,
+                  Register scratch,
+                  Condition cond,  // eq for new space, ne otherwise.
+                  Label* branch);
+
+  // Helper for finding the mark bits for an address.  Afterwards, the
+  // bitmap register points at the word with the mark bits and the mask
+  // the position of the first bit.  Leaves addr_reg unchanged.
+  inline void GetMarkBits(Register addr_reg,
+                          Register bitmap_reg,
+                          Register mask_reg);
+
   // Compute memory operands for safepoint stack slots.
   static int SafepointRegisterStackIndex(int reg_code);
   MemOperand SafepointRegisterSlot(Register reg);
@@ -1084,6 +1215,7 @@ class MacroAssembler: public Assembler {
 
   bool generating_stub_;
   bool allow_stub_calls_;
+  bool has_frame_;
   // This handle will be patched with the code object on installation.
   Handle<Object> code_object_;
 
diff --git a/deps/v8/src/arm/regexp-macro-assembler-arm.cc b/deps/v8/src/arm/regexp-macro-assembler-arm.cc
index cd76edbf1..c87646793 100644
--- a/deps/v8/src/arm/regexp-macro-assembler-arm.cc
+++ b/deps/v8/src/arm/regexp-macro-assembler-arm.cc
@@ -371,9 +371,12 @@ void RegExpMacroAssemblerARM::CheckNotBackReferenceIgnoreCase(
     // Isolate.
     __ mov(r3, Operand(ExternalReference::isolate_address()));
 
-    ExternalReference function =
-        ExternalReference::re_case_insensitive_compare_uc16(masm_->isolate());
-    __ CallCFunction(function, argument_count);
+    {
+      AllowExternalCallThatCantCauseGC scope(masm_);
+      ExternalReference function =
+          ExternalReference::re_case_insensitive_compare_uc16(masm_->isolate());
+      __ CallCFunction(function, argument_count);
+    }
 
     // Check if function returned non-zero for success or zero for failure.
     __ cmp(r0, Operand(0, RelocInfo::NONE));
@@ -611,6 +614,12 @@ Handle<HeapObject> RegExpMacroAssemblerARM::GetCode(Handle<String> source) {
 
   // Entry code:
   __ bind(&entry_label_);
+
+  // Tell the system that we have a stack frame.  Because the type is MANUAL, no
+  // is generated.
+  FrameScope scope(masm_, StackFrame::MANUAL);
+
+  // Actually emit code to start a new stack frame.
   // Push arguments
   // Save callee-save registers.
   // Start new stack frame.
diff --git a/deps/v8/src/arm/simulator-arm.cc b/deps/v8/src/arm/simulator-arm.cc
index 6af535553..570420262 100644
--- a/deps/v8/src/arm/simulator-arm.cc
+++ b/deps/v8/src/arm/simulator-arm.cc
@@ -1618,6 +1618,8 @@ void Simulator::HandleRList(Instruction* instr, bool load) {
   ProcessPUW(instr, num_regs, kPointerSize, &start_address, &end_address);
 
   intptr_t* address = reinterpret_cast<intptr_t*>(start_address);
+  // Catch null pointers a little earlier.
+  ASSERT(start_address > 8191 || start_address < 0);
   int reg = 0;
   while (rlist != 0) {
     if ((rlist & 1) != 0) {
diff --git a/deps/v8/src/arm/stub-cache-arm.cc b/deps/v8/src/arm/stub-cache-arm.cc
index f8565924b..4558afe68 100644
--- a/deps/v8/src/arm/stub-cache-arm.cc
+++ b/deps/v8/src/arm/stub-cache-arm.cc
@@ -431,7 +431,13 @@ void StubCompiler::GenerateStoreField(MacroAssembler* masm,
 
     // Update the write barrier for the array address.
     // Pass the now unused name_reg as a scratch register.
-    __ RecordWrite(receiver_reg, Operand(offset), name_reg, scratch);
+    __ mov(name_reg, r0);
+    __ RecordWriteField(receiver_reg,
+                        offset,
+                        name_reg,
+                        scratch,
+                        kLRHasNotBeenSaved,
+                        kDontSaveFPRegs);
   } else {
     // Write to the properties array.
     int offset = index * kPointerSize + FixedArray::kHeaderSize;
@@ -444,7 +450,13 @@ void StubCompiler::GenerateStoreField(MacroAssembler* masm,
 
     // Update the write barrier for the array address.
     // Ok to clobber receiver_reg and name_reg, since we return.
-    __ RecordWrite(scratch, Operand(offset), name_reg, receiver_reg);
+    __ mov(name_reg, r0);
+    __ RecordWriteField(scratch,
+                        offset,
+                        name_reg,
+                        receiver_reg,
+                        kLRHasNotBeenSaved,
+                        kDontSaveFPRegs);
   }
 
   // Return the value (register r0).
@@ -553,9 +565,10 @@ static void FreeSpaceForFastApiCall(MacroAssembler* masm) {
 }
 
 
-static MaybeObject* GenerateFastApiDirectCall(MacroAssembler* masm,
-                                      const CallOptimization& optimization,
-                                      int argc) {
+static MaybeObject* GenerateFastApiDirectCall(
+    MacroAssembler* masm,
+    const CallOptimization& optimization,
+    int argc) {
   // ----------- S t a t e -------------
   //  -- sp[0]              : holder (set by CheckPrototypes)
   //  -- sp[4]              : callee js function
@@ -591,6 +604,8 @@ static MaybeObject* GenerateFastApiDirectCall(MacroAssembler* masm,
   ApiFunction fun(api_function_address);
 
   const int kApiStackSpace = 4;
+
+  FrameScope frame_scope(masm, StackFrame::MANUAL);
   __ EnterExitFrame(false, kApiStackSpace);
 
   // r0 = v8::Arguments&
@@ -616,9 +631,11 @@ static MaybeObject* GenerateFastApiDirectCall(MacroAssembler* masm,
   ExternalReference ref = ExternalReference(&fun,
                                             ExternalReference::DIRECT_API_CALL,
                                             masm->isolate());
+  AllowExternalCallThatCantCauseGC scope(masm);
   return masm->TryCallApiFunctionAndReturn(ref, kStackUnwindSpace);
 }
 
+
 class CallInterceptorCompiler BASE_EMBEDDED {
  public:
   CallInterceptorCompiler(StubCompiler* stub_compiler,
@@ -794,7 +811,7 @@ class CallInterceptorCompiler BASE_EMBEDDED {
                                         miss_label);
 
     // Call a runtime function to load the interceptor property.
-    __ EnterInternalFrame();
+    FrameScope scope(masm, StackFrame::INTERNAL);
     // Save the name_ register across the call.
     __ push(name_);
 
@@ -811,7 +828,8 @@ class CallInterceptorCompiler BASE_EMBEDDED {
 
     // Restore the name_ register.
     __ pop(name_);
-    __ LeaveInternalFrame();
+
+    // Leave the internal frame.
   }
 
   void LoadWithInterceptor(MacroAssembler* masm,
@@ -820,18 +838,19 @@ class CallInterceptorCompiler BASE_EMBEDDED {
                            JSObject* holder_obj,
                            Register scratch,
                            Label* interceptor_succeeded) {
-    __ EnterInternalFrame();
-    __ Push(holder, name_);
-
-    CompileCallLoadPropertyWithInterceptor(masm,
-                                           receiver,
-                                           holder,
-                                           name_,
-                                           holder_obj);
-
-    __ pop(name_);  // Restore the name.
-    __ pop(receiver);  // Restore the holder.
-    __ LeaveInternalFrame();
+    {
+      FrameScope scope(masm, StackFrame::INTERNAL);
+      __ Push(holder, name_);
+
+      CompileCallLoadPropertyWithInterceptor(masm,
+                                             receiver,
+                                             holder,
+                                             name_,
+                                             holder_obj);
+
+      __ pop(name_);  // Restore the name.
+      __ pop(receiver);  // Restore the holder.
+    }
 
     // If interceptor returns no-result sentinel, call the constant function.
     __ LoadRoot(scratch, Heap::kNoInterceptorResultSentinelRootIndex);
@@ -1228,7 +1247,10 @@ MaybeObject* StubCompiler::GenerateLoadCallback(JSObject* object,
   ApiFunction fun(getter_address);
 
   const int kApiStackSpace = 1;
+
+  FrameScope frame_scope(masm(), StackFrame::MANUAL);
   __ EnterExitFrame(false, kApiStackSpace);
+
   // Create AccessorInfo instance on the stack above the exit frame with
   // scratch2 (internal::Object **args_) as the data.
   __ str(scratch2, MemOperand(sp, 1 * kPointerSize));
@@ -1288,41 +1310,43 @@ void StubCompiler::GenerateLoadInterceptor(JSObject* object,
 
     // Save necessary data before invoking an interceptor.
     // Requires a frame to make GC aware of pushed pointers.
-    __ EnterInternalFrame();
+    {
+      FrameScope frame_scope(masm(), StackFrame::INTERNAL);
 
-    if (lookup->type() == CALLBACKS && !receiver.is(holder_reg)) {
-      // CALLBACKS case needs a receiver to be passed into C++ callback.
-      __ Push(receiver, holder_reg, name_reg);
-    } else {
-      __ Push(holder_reg, name_reg);
-    }
+      if (lookup->type() == CALLBACKS && !receiver.is(holder_reg)) {
+        // CALLBACKS case needs a receiver to be passed into C++ callback.
+        __ Push(receiver, holder_reg, name_reg);
+      } else {
+        __ Push(holder_reg, name_reg);
+      }
 
-    // Invoke an interceptor.  Note: map checks from receiver to
-    // interceptor's holder has been compiled before (see a caller
-    // of this method.)
-    CompileCallLoadPropertyWithInterceptor(masm(),
-                                           receiver,
-                                           holder_reg,
-                                           name_reg,
-                                           interceptor_holder);
-
-    // Check if interceptor provided a value for property.  If it's
-    // the case, return immediately.
-    Label interceptor_failed;
-    __ LoadRoot(scratch1, Heap::kNoInterceptorResultSentinelRootIndex);
-    __ cmp(r0, scratch1);
-    __ b(eq, &interceptor_failed);
-    __ LeaveInternalFrame();
-    __ Ret();
+      // Invoke an interceptor.  Note: map checks from receiver to
+      // interceptor's holder has been compiled before (see a caller
+      // of this method.)
+      CompileCallLoadPropertyWithInterceptor(masm(),
+                                             receiver,
+                                             holder_reg,
+                                             name_reg,
+                                             interceptor_holder);
+
+      // Check if interceptor provided a value for property.  If it's
+      // the case, return immediately.
+      Label interceptor_failed;
+      __ LoadRoot(scratch1, Heap::kNoInterceptorResultSentinelRootIndex);
+      __ cmp(r0, scratch1);
+      __ b(eq, &interceptor_failed);
+      frame_scope.GenerateLeaveFrame();
+      __ Ret();
 
-    __ bind(&interceptor_failed);
-    __ pop(name_reg);
-    __ pop(holder_reg);
-    if (lookup->type() == CALLBACKS && !receiver.is(holder_reg)) {
-      __ pop(receiver);
-    }
+      __ bind(&interceptor_failed);
+      __ pop(name_reg);
+      __ pop(holder_reg);
+      if (lookup->type() == CALLBACKS && !receiver.is(holder_reg)) {
+        __ pop(receiver);
+      }
 
-    __ LeaveInternalFrame();
+      // Leave the internal frame.
+    }
 
     // Check that the maps from interceptor's holder to lookup's holder
     // haven't changed.  And load lookup's holder into |holder| register.
@@ -1556,7 +1580,7 @@ MaybeObject* CallStubCompiler::CompileArrayPushCall(Object* object,
                 DONT_DO_SMI_CHECK);
 
     if (argc == 1) {  // Otherwise fall through to call the builtin.
-      Label exit, with_write_barrier, attempt_to_grow_elements;
+      Label attempt_to_grow_elements;
 
       // Get the array's length into r0 and calculate new length.
       __ ldr(r0, FieldMemOperand(receiver, JSArray::kLengthOffset));
@@ -1571,11 +1595,15 @@ MaybeObject* CallStubCompiler::CompileArrayPushCall(Object* object,
       __ cmp(r0, r4);
       __ b(gt, &attempt_to_grow_elements);
 
+      // Check if value is a smi.
+      Label with_write_barrier;
+      __ ldr(r4, MemOperand(sp, (argc - 1) * kPointerSize));
+      __ JumpIfNotSmi(r4, &with_write_barrier);
+
       // Save new length.
       __ str(r0, FieldMemOperand(receiver, JSArray::kLengthOffset));
 
       // Push the element.
-      __ ldr(r4, MemOperand(sp, (argc - 1) * kPointerSize));
       // We may need a register containing the address end_elements below,
       // so write back the value in end_elements.
       __ add(end_elements, elements,
@@ -1585,14 +1613,31 @@ MaybeObject* CallStubCompiler::CompileArrayPushCall(Object* object,
       __ str(r4, MemOperand(end_elements, kEndElementsOffset, PreIndex));
 
       // Check for a smi.
-      __ JumpIfNotSmi(r4, &with_write_barrier);
-      __ bind(&exit);
       __ Drop(argc + 1);
       __ Ret();
 
       __ bind(&with_write_barrier);
-      __ InNewSpace(elements, r4, eq, &exit);
-      __ RecordWriteHelper(elements, end_elements, r4);
+
+      __ ldr(r6, FieldMemOperand(receiver, HeapObject::kMapOffset));
+      __ CheckFastSmiOnlyElements(r6, r6, &call_builtin);
+
+      // Save new length.
+      __ str(r0, FieldMemOperand(receiver, JSArray::kLengthOffset));
+
+      // Push the element.
+      // We may need a register containing the address end_elements below,
+      // so write back the value in end_elements.
+      __ add(end_elements, elements,
+             Operand(r0, LSL, kPointerSizeLog2 - kSmiTagSize));
+      __ str(r4, MemOperand(end_elements, kEndElementsOffset, PreIndex));
+
+      __ RecordWrite(elements,
+                     end_elements,
+                     r4,
+                     kLRHasNotBeenSaved,
+                     kDontSaveFPRegs,
+                     EMIT_REMEMBERED_SET,
+                     OMIT_SMI_CHECK);
       __ Drop(argc + 1);
       __ Ret();
 
@@ -1604,6 +1649,15 @@ MaybeObject* CallStubCompiler::CompileArrayPushCall(Object* object,
         __ b(&call_builtin);
       }
 
+      __ ldr(r2, MemOperand(sp, (argc - 1) * kPointerSize));
+      // Growing elements that are SMI-only requires special handling in case
+      // the new element is non-Smi. For now, delegate to the builtin.
+      Label no_fast_elements_check;
+      __ JumpIfSmi(r2, &no_fast_elements_check);
+      __ ldr(r7, FieldMemOperand(receiver, HeapObject::kMapOffset));
+      __ CheckFastObjectElements(r7, r7, &call_builtin);
+      __ bind(&no_fast_elements_check);
+
       Isolate* isolate = masm()->isolate();
       ExternalReference new_space_allocation_top =
           ExternalReference::new_space_allocation_top_address(isolate);
@@ -1630,8 +1684,7 @@ MaybeObject* CallStubCompiler::CompileArrayPushCall(Object* object,
       // Update new_space_allocation_top.
       __ str(r6, MemOperand(r7));
       // Push the argument.
-      __ ldr(r6, MemOperand(sp, (argc - 1) * kPointerSize));
-      __ str(r6, MemOperand(end_elements));
+      __ str(r2, MemOperand(end_elements));
       // Fill the rest with holes.
       __ LoadRoot(r6, Heap::kTheHoleValueRootIndex);
       for (int i = 1; i < kAllocationDelta; i++) {
@@ -2713,6 +2766,15 @@ MaybeObject* StoreStubCompiler::CompileStoreGlobal(GlobalObject* object,
   // Store the value in the cell.
   __ str(r0, FieldMemOperand(r4, JSGlobalPropertyCell::kValueOffset));
 
+  __ mov(r1, r0);
+  __ RecordWriteField(r4,
+                      JSGlobalPropertyCell::kValueOffset,
+                      r1,
+                      r2,
+                      kLRHasNotBeenSaved,
+                      kDontSaveFPRegs,
+                      OMIT_REMEMBERED_SET);
+
   Counters* counters = masm()->isolate()->counters();
   __ IncrementCounter(counters->named_store_global_inline(), 1, r4, r3);
   __ Ret();
@@ -3116,7 +3178,7 @@ MaybeObject* KeyedLoadStubCompiler::CompileLoadElement(Map* receiver_map) {
 }
 
 
-MaybeObject* KeyedLoadStubCompiler::CompileLoadMegamorphic(
+MaybeObject* KeyedLoadStubCompiler::CompileLoadPolymorphic(
     MapList* receiver_maps,
     CodeList* handler_ics) {
   // ----------- S t a t e -------------
@@ -3212,9 +3274,10 @@ MaybeObject* KeyedStoreStubCompiler::CompileStoreElement(Map* receiver_map) {
 }
 
 
-MaybeObject* KeyedStoreStubCompiler::CompileStoreMegamorphic(
+MaybeObject* KeyedStoreStubCompiler::CompileStorePolymorphic(
     MapList* receiver_maps,
-    CodeList* handler_ics) {
+    CodeList* handler_stubs,
+    MapList* transitioned_maps) {
   // ----------- S t a t e -------------
   //  -- r0    : value
   //  -- r1    : key
@@ -3227,12 +3290,20 @@ MaybeObject* KeyedStoreStubCompiler::CompileStoreMegamorphic(
 
   int receiver_count = receiver_maps->length();
   __ ldr(r3, FieldMemOperand(r2, HeapObject::kMapOffset));
-  for (int current = 0; current < receiver_count; ++current) {
-    Handle<Map> map(receiver_maps->at(current));
-    Handle<Code> code(handler_ics->at(current));
+  for (int i = 0; i < receiver_count; ++i) {
+    Handle<Map> map(receiver_maps->at(i));
+    Handle<Code> code(handler_stubs->at(i));
     __ mov(ip, Operand(map));
     __ cmp(r3, ip);
-    __ Jump(code, RelocInfo::CODE_TARGET, eq);
+    if (transitioned_maps->at(i) == NULL) {
+      __ Jump(code, RelocInfo::CODE_TARGET, eq);
+    } else {
+      Label next_map;
+      __ b(eq, &next_map);
+      __ mov(r4, Operand(Handle<Map>(transitioned_maps->at(i))));
+      __ Jump(code, RelocInfo::CODE_TARGET, al);
+      __ bind(&next_map);
+    }
   }
 
   __ bind(&miss);
@@ -3454,6 +3525,7 @@ static bool IsElementTypeSigned(ElementsKind elements_kind) {
     case EXTERNAL_FLOAT_ELEMENTS:
     case EXTERNAL_DOUBLE_ELEMENTS:
     case FAST_ELEMENTS:
+    case FAST_SMI_ONLY_ELEMENTS:
     case FAST_DOUBLE_ELEMENTS:
     case DICTIONARY_ELEMENTS:
     case NON_STRICT_ARGUMENTS_ELEMENTS:
@@ -3540,6 +3612,7 @@ void KeyedLoadStubCompiler::GenerateLoadExternalArray(
       }
       break;
     case FAST_ELEMENTS:
+    case FAST_SMI_ONLY_ELEMENTS:
     case FAST_DOUBLE_ELEMENTS:
     case DICTIONARY_ELEMENTS:
     case NON_STRICT_ARGUMENTS_ELEMENTS:
@@ -3880,6 +3953,7 @@ void KeyedStoreStubCompiler::GenerateStoreExternalArray(
       }
       break;
     case FAST_ELEMENTS:
+    case FAST_SMI_ONLY_ELEMENTS:
     case FAST_DOUBLE_ELEMENTS:
     case DICTIONARY_ELEMENTS:
     case NON_STRICT_ARGUMENTS_ELEMENTS:
@@ -3943,6 +4017,7 @@ void KeyedStoreStubCompiler::GenerateStoreExternalArray(
           case EXTERNAL_FLOAT_ELEMENTS:
           case EXTERNAL_DOUBLE_ELEMENTS:
           case FAST_ELEMENTS:
+          case FAST_SMI_ONLY_ELEMENTS:
           case FAST_DOUBLE_ELEMENTS:
           case DICTIONARY_ELEMENTS:
           case NON_STRICT_ARGUMENTS_ELEMENTS:
@@ -4082,6 +4157,7 @@ void KeyedStoreStubCompiler::GenerateStoreExternalArray(
           case EXTERNAL_FLOAT_ELEMENTS:
           case EXTERNAL_DOUBLE_ELEMENTS:
           case FAST_ELEMENTS:
+          case FAST_SMI_ONLY_ELEMENTS:
           case FAST_DOUBLE_ELEMENTS:
           case DICTIONARY_ELEMENTS:
           case NON_STRICT_ARGUMENTS_ELEMENTS:
@@ -4234,8 +4310,10 @@ void KeyedLoadStubCompiler::GenerateLoadFastDoubleElement(
 }
 
 
-void KeyedStoreStubCompiler::GenerateStoreFastElement(MacroAssembler* masm,
-                                                      bool is_js_array) {
+void KeyedStoreStubCompiler::GenerateStoreFastElement(
+    MacroAssembler* masm,
+    bool is_js_array,
+    ElementsKind elements_kind) {
   // ----------- S t a t e -------------
   //  -- r0    : value
   //  -- r1    : key
@@ -4244,7 +4322,7 @@ void KeyedStoreStubCompiler::GenerateStoreFastElement(MacroAssembler* masm,
   //  -- r3    : scratch
   //  -- r4    : scratch (elements)
   // -----------------------------------
-  Label miss_force_generic;
+  Label miss_force_generic, transition_elements_kind;
 
   Register value_reg = r0;
   Register key_reg = r1;
@@ -4277,15 +4355,33 @@ void KeyedStoreStubCompiler::GenerateStoreFastElement(MacroAssembler* masm,
   __ cmp(key_reg, scratch);
   __ b(hs, &miss_force_generic);
 
-  __ add(scratch,
-         elements_reg, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
-  STATIC_ASSERT(kSmiTag == 0 && kSmiTagSize < kPointerSizeLog2);
-  __ str(value_reg,
-         MemOperand(scratch, key_reg, LSL, kPointerSizeLog2 - kSmiTagSize));
-  __ RecordWrite(scratch,
-                 Operand(key_reg, LSL, kPointerSizeLog2 - kSmiTagSize),
-                 receiver_reg , elements_reg);
-
+  if (elements_kind == FAST_SMI_ONLY_ELEMENTS) {
+    __ JumpIfNotSmi(value_reg, &transition_elements_kind);
+    __ add(scratch,
+           elements_reg,
+           Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+    STATIC_ASSERT(kSmiTag == 0 && kSmiTagSize < kPointerSizeLog2);
+    __ add(scratch,
+           scratch,
+           Operand(key_reg, LSL, kPointerSizeLog2 - kSmiTagSize));
+    __ str(value_reg, MemOperand(scratch));
+  } else {
+    ASSERT(elements_kind == FAST_ELEMENTS);
+    __ add(scratch,
+           elements_reg,
+           Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+    STATIC_ASSERT(kSmiTag == 0 && kSmiTagSize < kPointerSizeLog2);
+    __ add(scratch,
+           scratch,
+           Operand(key_reg, LSL, kPointerSizeLog2 - kSmiTagSize));
+    __ str(value_reg, MemOperand(scratch));
+    __ mov(receiver_reg, value_reg);
+    __ RecordWrite(elements_reg,  // Object.
+                   scratch,       // Address.
+                   receiver_reg,  // Value.
+                   kLRHasNotBeenSaved,
+                   kDontSaveFPRegs);
+  }
   // value_reg (r0) is preserved.
   // Done.
   __ Ret();
@@ -4294,6 +4390,10 @@ void KeyedStoreStubCompiler::GenerateStoreFastElement(MacroAssembler* masm,
   Handle<Code> ic =
       masm->isolate()->builtins()->KeyedStoreIC_MissForceGeneric();
   __ Jump(ic, RelocInfo::CODE_TARGET);
+
+  __ bind(&transition_elements_kind);
+  Handle<Code> ic_miss = masm->isolate()->builtins()->KeyedStoreIC_Miss();
+  __ Jump(ic_miss, RelocInfo::CODE_TARGET);
 }
 
 
@@ -4309,15 +4409,15 @@ void KeyedStoreStubCompiler::GenerateStoreFastDoubleElement(
   //  -- r4    : scratch
   //  -- r5    : scratch
   // -----------------------------------
-  Label miss_force_generic, smi_value, is_nan, maybe_nan, have_double_value;
+  Label miss_force_generic, transition_elements_kind;
 
   Register value_reg = r0;
   Register key_reg = r1;
   Register receiver_reg = r2;
-  Register scratch = r3;
-  Register elements_reg = r4;
-  Register mantissa_reg = r5;
-  Register exponent_reg = r6;
+  Register elements_reg = r3;
+  Register scratch1 = r4;
+  Register scratch2 = r5;
+  Register scratch3 = r6;
   Register scratch4 = r7;
 
   // This stub is meant to be tail-jumped to, the receiver must already
@@ -4329,90 +4429,25 @@ void KeyedStoreStubCompiler::GenerateStoreFastDoubleElement(
 
   // Check that the key is within bounds.
   if (is_js_array) {
-    __ ldr(scratch, FieldMemOperand(receiver_reg, JSArray::kLengthOffset));
+    __ ldr(scratch1, FieldMemOperand(receiver_reg, JSArray::kLengthOffset));
   } else {
-    __ ldr(scratch,
+    __ ldr(scratch1,
            FieldMemOperand(elements_reg, FixedArray::kLengthOffset));
   }
   // Compare smis, unsigned compare catches both negative and out-of-bound
   // indexes.
-  __ cmp(key_reg, scratch);
+  __ cmp(key_reg, scratch1);
   __ b(hs, &miss_force_generic);
 
-  // Handle smi values specially.
-  __ JumpIfSmi(value_reg, &smi_value);
-
-  // Ensure that the object is a heap number
-  __ CheckMap(value_reg,
-              scratch,
-              masm->isolate()->factory()->heap_number_map(),
-              &miss_force_generic,
-              DONT_DO_SMI_CHECK);
-
-  // Check for nan: all NaN values have a value greater (signed) than 0x7ff00000
-  // in the exponent.
-  __ mov(scratch, Operand(kNaNOrInfinityLowerBoundUpper32));
-  __ ldr(exponent_reg, FieldMemOperand(value_reg, HeapNumber::kExponentOffset));
-  __ cmp(exponent_reg, scratch);
-  __ b(ge, &maybe_nan);
-
-  __ ldr(mantissa_reg, FieldMemOperand(value_reg, HeapNumber::kMantissaOffset));
-
-  __ bind(&have_double_value);
-  __ add(scratch, elements_reg,
-         Operand(key_reg, LSL, kDoubleSizeLog2 - kSmiTagSize));
-  __ str(mantissa_reg, FieldMemOperand(scratch, FixedDoubleArray::kHeaderSize));
-  uint32_t offset = FixedDoubleArray::kHeaderSize + sizeof(kHoleNanLower32);
-  __ str(exponent_reg, FieldMemOperand(scratch, offset));
-  __ Ret();
-
-  __ bind(&maybe_nan);
-  // Could be NaN or Infinity. If fraction is not zero, it's NaN, otherwise
-  // it's an Infinity, and the non-NaN code path applies.
-  __ b(gt, &is_nan);
-  __ ldr(mantissa_reg, FieldMemOperand(value_reg, HeapNumber::kMantissaOffset));
-  __ cmp(mantissa_reg, Operand(0));
-  __ b(eq, &have_double_value);
-  __ bind(&is_nan);
-  // Load canonical NaN for storing into the double array.
-  uint64_t nan_int64 = BitCast<uint64_t>(
-      FixedDoubleArray::canonical_not_the_hole_nan_as_double());
-  __ mov(mantissa_reg, Operand(static_cast<uint32_t>(nan_int64)));
-  __ mov(exponent_reg, Operand(static_cast<uint32_t>(nan_int64 >> 32)));
-  __ jmp(&have_double_value);
-
-  __ bind(&smi_value);
-  __ add(scratch, elements_reg,
-         Operand(FixedDoubleArray::kHeaderSize - kHeapObjectTag));
-  __ add(scratch, scratch,
-         Operand(key_reg, LSL, kDoubleSizeLog2 - kSmiTagSize));
-  // scratch is now effective address of the double element
-
-  FloatingPointHelper::Destination destination;
-  if (CpuFeatures::IsSupported(VFP3)) {
-    destination = FloatingPointHelper::kVFPRegisters;
-  } else {
-    destination = FloatingPointHelper::kCoreRegisters;
-  }
-
-  Register untagged_value = receiver_reg;
-  __ SmiUntag(untagged_value, value_reg);
-  FloatingPointHelper::ConvertIntToDouble(
-      masm,
-      untagged_value,
-      destination,
-      d0,
-      mantissa_reg,
-      exponent_reg,
-      scratch4,
-      s2);
-  if (destination == FloatingPointHelper::kVFPRegisters) {
-    CpuFeatures::Scope scope(VFP3);
-    __ vstr(d0, scratch, 0);
-  } else {
-    __ str(mantissa_reg, MemOperand(scratch, 0));
-    __ str(exponent_reg, MemOperand(scratch, Register::kSizeInBytes));
-  }
+  __ StoreNumberToDoubleElements(value_reg,
+                                 key_reg,
+                                 receiver_reg,
+                                 elements_reg,
+                                 scratch1,
+                                 scratch2,
+                                 scratch3,
+                                 scratch4,
+                                 &transition_elements_kind);
   __ Ret();
 
   // Handle store cache miss, replacing the ic with the generic stub.
@@ -4420,6 +4455,10 @@ void KeyedStoreStubCompiler::GenerateStoreFastDoubleElement(
   Handle<Code> ic =
       masm->isolate()->builtins()->KeyedStoreIC_MissForceGeneric();
   __ Jump(ic, RelocInfo::CODE_TARGET);
+
+  __ bind(&transition_elements_kind);
+  Handle<Code> ic_miss = masm->isolate()->builtins()->KeyedStoreIC_Miss();
+  __ Jump(ic_miss, RelocInfo::CODE_TARGET);
 }