Version 3.7.1

Achieved 33% speedup in debug-mode tests.

Removed special casing of calls to RegExp test and exec methods with no
argument.  Now matches new JSC behaviour.  crbug.com/75740.

Return the empty string on cyclic references in toString (ES5
conformance).

Fixed bug triggered by JSBeautifier.  crbug.com/100409.

Made Math.random state per-context instead of per-process (issue 864).

Fixed stack traces to skip native functions.

Make snapshots (new contexts) smaller and faster.

Fixed handling of Function.apply for non-array arguments.

Fixed evaluation order in defineProperties to match FireFox.

Fixed handling of non-object receivers for array builtins,
crbug.com/100702.

Multiple fixes to improve compliance with test262.

Fixed compatibility with older Android releases.

Fixed compilation with gcc-4.5.3.

Improved performance of WriteUtf8, issue 1665.

Made native syntax an early error in the preparser.

Fixed issues 793 and 893 relating to Function.prototype.bind.

Improved let, const, Set and Map support and other Harmony features
(behind the --harmony flag).

Changed evaluation order for > and <= to match ES5 instead of ES3.

Bug fixes and performance improvements on all platforms.
Review URL: http://codereview.chromium.org/8404030

git-svn-id: http://v8.googlecode.com/svn/trunk@9809 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
diff --git a/src/arm/assembler-arm-inl.h b/src/arm/assembler-arm-inl.h
index 93cecf5..7f9f4ce 100644
--- a/src/arm/assembler-arm-inl.h
+++ b/src/arm/assembler-arm-inl.h
@@ -74,10 +74,10 @@
 }
 
 
-void RelocInfo::set_target_address(Address target) {
+void RelocInfo::set_target_address(Address target, WriteBarrierMode mode) {
   ASSERT(IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY);
   Assembler::set_target_address_at(pc_, target);
-  if (host() != NULL && IsCodeTarget(rmode_)) {
+  if (mode == UPDATE_WRITE_BARRIER && host() != NULL && IsCodeTarget(rmode_)) {
     Object* target_code = Code::GetCodeFromTargetAddress(target);
     host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(
         host(), this, HeapObject::cast(target_code));
@@ -103,10 +103,12 @@
 }
 
 
-void RelocInfo::set_target_object(Object* target) {
+void RelocInfo::set_target_object(Object* target, WriteBarrierMode mode) {
   ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
   Assembler::set_target_address_at(pc_, reinterpret_cast<Address>(target));
-  if (host() != NULL && target->IsHeapObject()) {
+  if (mode == UPDATE_WRITE_BARRIER &&
+      host() != NULL &&
+      target->IsHeapObject()) {
     host()->GetHeap()->incremental_marking()->RecordWrite(
         host(), &Memory::Object_at(pc_), HeapObject::cast(target));
   }
@@ -136,11 +138,12 @@
 }
 
 
-void RelocInfo::set_target_cell(JSGlobalPropertyCell* cell) {
+void RelocInfo::set_target_cell(JSGlobalPropertyCell* cell,
+                                WriteBarrierMode mode) {
   ASSERT(rmode_ == RelocInfo::GLOBAL_PROPERTY_CELL);
   Address address = cell->address() + JSGlobalPropertyCell::kValueOffset;
   Memory::Address_at(pc_) = address;
-  if (host() != NULL) {
+  if (mode == UPDATE_WRITE_BARRIER && host() != NULL) {
     // TODO(1550) We are passing NULL as a slot because cell can never be on
     // evacuation candidate.
     host()->GetHeap()->incremental_marking()->RecordWrite(
diff --git a/src/arm/assembler-arm.h b/src/arm/assembler-arm.h
index d19b64d..247479d 100644
--- a/src/arm/assembler-arm.h
+++ b/src/arm/assembler-arm.h
@@ -304,9 +304,9 @@
 const DwVfpRegister d15 = { 15 };
 
 // Aliases for double registers.
-const DwVfpRegister kFirstCalleeSavedDoubleReg = d8;
-const DwVfpRegister kLastCalleeSavedDoubleReg = d15;
-const DwVfpRegister kDoubleRegZero = d14;
+static const DwVfpRegister& kFirstCalleeSavedDoubleReg = d8;
+static const DwVfpRegister& kLastCalleeSavedDoubleReg = d15;
+static const DwVfpRegister& kDoubleRegZero = d14;
 
 
 // Coprocessor register
diff --git a/src/arm/builtins-arm.cc b/src/arm/builtins-arm.cc
index 32b7896..29bf190 100644
--- a/src/arm/builtins-arm.cc
+++ b/src/arm/builtins-arm.cc
@@ -86,12 +86,6 @@
 }
 
 
-// This constant has the same value as JSArray::kPreallocatedArrayElements and
-// if JSArray::kPreallocatedArrayElements is changed handling of loop unfolding
-// below should be reconsidered.
-static const int kLoopUnfoldLimit = 4;
-
-
 // Allocate an empty JSArray. The allocated array is put into the result
 // register. An elements backing store is allocated with size initial_capacity
 // and filled with the hole values.
@@ -101,9 +95,9 @@
                                  Register scratch1,
                                  Register scratch2,
                                  Register scratch3,
-                                 int initial_capacity,
                                  Label* gc_required) {
-  ASSERT(initial_capacity > 0);
+  const int initial_capacity = JSArray::kPreallocatedArrayElements;
+  STATIC_ASSERT(initial_capacity >= 0);
   // Load the initial map from the array function.
   __ ldr(scratch1, FieldMemOperand(array_function,
                                    JSFunction::kPrototypeOrInitialMapOffset));
@@ -153,12 +147,24 @@
   ASSERT_EQ(1 * kPointerSize, FixedArray::kLengthOffset);
   __ str(scratch3, MemOperand(scratch1, kPointerSize, PostIndex));
 
-  // Fill the FixedArray with the hole value.
+  // Fill the FixedArray with the hole value. Inline the code if short.
+  if (initial_capacity == 0) return;
   ASSERT_EQ(2 * kPointerSize, FixedArray::kHeaderSize);
-  ASSERT(initial_capacity <= kLoopUnfoldLimit);
   __ LoadRoot(scratch3, Heap::kTheHoleValueRootIndex);
-  for (int i = 0; i < initial_capacity; i++) {
+  static const int kLoopUnfoldLimit = 4;
+  if (initial_capacity <= kLoopUnfoldLimit) {
+    for (int i = 0; i < initial_capacity; i++) {
+      __ str(scratch3, MemOperand(scratch1, kPointerSize, PostIndex));
+    }
+  } else {
+    Label loop, entry;
+    __ add(scratch2, scratch1, Operand(initial_capacity * kPointerSize));
+    __ b(&entry);
+    __ bind(&loop);
     __ str(scratch3, MemOperand(scratch1, kPointerSize, PostIndex));
+    __ bind(&entry);
+    __ cmp(scratch1, scratch2);
+    __ b(lt, &loop);
   }
 }
 
@@ -173,7 +179,7 @@
 // register elements_array_storage is scratched.
 static void AllocateJSArray(MacroAssembler* masm,
                             Register array_function,  // Array function.
-                            Register array_size,  // As a smi.
+                            Register array_size,  // As a smi, cannot be 0.
                             Register result,
                             Register elements_array_storage,
                             Register elements_array_end,
@@ -181,32 +187,18 @@
                             Register scratch2,
                             bool fill_with_hole,
                             Label* gc_required) {
-  Label not_empty, allocated;
-
   // Load the initial map from the array function.
   __ ldr(elements_array_storage,
          FieldMemOperand(array_function,
                          JSFunction::kPrototypeOrInitialMapOffset));
 
-  // Check whether an empty sized array is requested.
-  __ tst(array_size, array_size);
-  __ b(ne, &not_empty);
-
-  // If an empty array is requested allocate a small elements array anyway. This
-  // keeps the code below free of special casing for the empty array.
-  int size = JSArray::kSize +
-             FixedArray::SizeFor(JSArray::kPreallocatedArrayElements);
-  __ AllocateInNewSpace(size,
-                        result,
-                        elements_array_end,
-                        scratch1,
-                        gc_required,
-                        TAG_OBJECT);
-  __ jmp(&allocated);
+  if (FLAG_debug_code) {  // Assert that array size is not zero.
+    __ tst(array_size, array_size);
+    __ Assert(ne, "array size is unexpectedly 0");
+  }
 
   // Allocate the JSArray object together with space for a FixedArray with the
   // requested number of elements.
-  __ bind(&not_empty);
   STATIC_ASSERT(kSmiTagSize == 1 && kSmiTag == 0);
   __ mov(elements_array_end,
          Operand((JSArray::kSize + FixedArray::kHeaderSize) / kPointerSize));
@@ -226,7 +218,6 @@
   // result: JSObject
   // elements_array_storage: initial map
   // array_size: size of array (smi)
-  __ bind(&allocated);
   __ str(elements_array_storage, FieldMemOperand(result, JSObject::kMapOffset));
   __ LoadRoot(elements_array_storage, Heap::kEmptyFixedArrayRootIndex);
   __ str(elements_array_storage,
@@ -256,14 +247,6 @@
   ASSERT_EQ(0 * kPointerSize, FixedArray::kMapOffset);
   __ str(scratch1, MemOperand(elements_array_storage, kPointerSize, PostIndex));
   STATIC_ASSERT(kSmiTag == 0);
-  __ tst(array_size, array_size);
-  // Length of the FixedArray is the number of pre-allocated elements if
-  // the actual JSArray has length 0 and the size of the JSArray for non-empty
-  // JSArrays. The length of a FixedArray is stored as a smi.
-  __ mov(array_size,
-         Operand(Smi::FromInt(JSArray::kPreallocatedArrayElements)),
-         LeaveCC,
-         eq);
   ASSERT_EQ(1 * kPointerSize, FixedArray::kLengthOffset);
   __ str(array_size,
          MemOperand(elements_array_storage, kPointerSize, PostIndex));
@@ -311,20 +294,20 @@
 static void ArrayNativeCode(MacroAssembler* masm,
                             Label* call_generic_code) {
   Counters* counters = masm->isolate()->counters();
-  Label argc_one_or_more, argc_two_or_more;
+  Label argc_one_or_more, argc_two_or_more, not_empty_array, empty_array;
 
   // Check for array construction with zero arguments or one.
   __ cmp(r0, Operand(0, RelocInfo::NONE));
   __ b(ne, &argc_one_or_more);
 
   // Handle construction of an empty array.
+  __ bind(&empty_array);
   AllocateEmptyJSArray(masm,
                        r1,
                        r2,
                        r3,
                        r4,
                        r5,
-                       JSArray::kPreallocatedArrayElements,
                        call_generic_code);
   __ IncrementCounter(counters->array_function_native(), 1, r3, r4);
   // Setup return value, remove receiver from stack and return.
@@ -339,6 +322,13 @@
   __ b(ne, &argc_two_or_more);
   STATIC_ASSERT(kSmiTag == 0);
   __ ldr(r2, MemOperand(sp));  // Get the argument from the stack.
+  __ tst(r2, r2);
+  __ b(ne, &not_empty_array);
+  __ Drop(1);  // Adjust stack.
+  __ mov(r0, Operand(0));  // Treat this as a call with argc of zero.
+  __ b(&empty_array);
+
+  __ bind(&not_empty_array);
   __ and_(r3, r2, Operand(kIntptrSignBit | kSmiTagMask), SetCC);
   __ b(ne, call_generic_code);
 
@@ -1027,9 +1017,9 @@
     __ ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
 
     // Set up the roots register.
-    ExternalReference roots_address =
-        ExternalReference::roots_address(masm->isolate());
-    __ mov(r10, Operand(roots_address));
+    ExternalReference roots_array_start =
+        ExternalReference::roots_array_start(masm->isolate());
+    __ mov(r10, Operand(roots_array_start));
 
     // Push the function and the receiver onto the stack.
     __ push(r1);
diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc
index 44923a1..412ba00 100644
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -263,7 +263,12 @@
   // [sp + (2 * kPointerSize)]: literals array.
 
   // All sizes here are multiples of kPointerSize.
-  int elements_size = (length_ > 0) ? FixedArray::SizeFor(length_) : 0;
+  int elements_size = 0;
+  if (length_ > 0) {
+    elements_size = mode_ == CLONE_DOUBLE_ELEMENTS
+        ? FixedDoubleArray::SizeFor(length_)
+        : FixedArray::SizeFor(length_);
+  }
   int size = JSArray::kSize + elements_size;
 
   // Load boilerplate object into r3 and check if we need to create a
@@ -283,6 +288,9 @@
     if (mode_ == CLONE_ELEMENTS) {
       message = "Expected (writable) fixed array";
       expected_map_index = Heap::kFixedArrayMapRootIndex;
+    } else if (mode_ == CLONE_DOUBLE_ELEMENTS) {
+      message = "Expected (writable) fixed double array";
+      expected_map_index = Heap::kFixedDoubleArrayMapRootIndex;
     } else {
       ASSERT(mode_ == COPY_ON_WRITE_ELEMENTS);
       message = "Expected copy-on-write fixed array";
@@ -322,6 +330,7 @@
     __ str(r2, FieldMemOperand(r0, JSArray::kElementsOffset));
 
     // Copy the elements array.
+    ASSERT((elements_size % kPointerSize) == 0);
     __ CopyFields(r2, r3, r1.bit(), elements_size / kPointerSize);
   }
 
@@ -3913,7 +3922,7 @@
   }
 
   // Get the prototype of the function.
-  __ TryGetFunctionPrototype(function, prototype, scratch, &slow);
+  __ TryGetFunctionPrototype(function, prototype, scratch, &slow, true);
 
   // Check that the function prototype is a JS object.
   __ JumpIfSmi(prototype, &slow);
@@ -6668,7 +6677,82 @@
 }
 
 
-MaybeObject* StringDictionaryLookupStub::GenerateNegativeLookup(
+void StringDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
+                                                        Label* miss,
+                                                        Label* done,
+                                                        Register receiver,
+                                                        Register properties,
+                                                        Handle<String> name,
+                                                        Register scratch0) {
+  // If names of slots in range from 1 to kProbes - 1 for the hash value are
+  // not equal to the name and kProbes-th slot is not used (its name is the
+  // undefined value), it guarantees the hash table doesn't contain the
+  // property. It's true even if some slots represent deleted properties
+  // (their names are the null value).
+  for (int i = 0; i < kInlinedProbes; i++) {
+    // scratch0 points to properties hash.
+    // Compute the masked index: (hash + i + i * i) & mask.
+    Register index = scratch0;
+    // Capacity is smi 2^n.
+    __ ldr(index, FieldMemOperand(properties, kCapacityOffset));
+    __ sub(index, index, Operand(1));
+    __ and_(index, index, Operand(
+        Smi::FromInt(name->Hash() + StringDictionary::GetProbeOffset(i))));
+
+    // Scale the index by multiplying by the entry size.
+    ASSERT(StringDictionary::kEntrySize == 3);
+    __ add(index, index, Operand(index, LSL, 1));  // index *= 3.
+
+    Register entity_name = scratch0;
+    // Having undefined at this place means the name is not contained.
+    ASSERT_EQ(kSmiTagSize, 1);
+    Register tmp = properties;
+    __ add(tmp, properties, Operand(index, LSL, 1));
+    __ ldr(entity_name, FieldMemOperand(tmp, kElementsStartOffset));
+
+    ASSERT(!tmp.is(entity_name));
+    __ LoadRoot(tmp, Heap::kUndefinedValueRootIndex);
+    __ cmp(entity_name, tmp);
+    __ b(eq, done);
+
+    if (i != kInlinedProbes - 1) {
+      // Stop if found the property.
+      __ cmp(entity_name, Operand(Handle<String>(name)));
+      __ b(eq, miss);
+
+      // Check if the entry name is not a symbol.
+      __ ldr(entity_name, FieldMemOperand(entity_name, HeapObject::kMapOffset));
+      __ ldrb(entity_name,
+              FieldMemOperand(entity_name, Map::kInstanceTypeOffset));
+      __ tst(entity_name, Operand(kIsSymbolMask));
+      __ b(eq, miss);
+
+      // Restore the properties.
+      __ ldr(properties,
+             FieldMemOperand(receiver, JSObject::kPropertiesOffset));
+    }
+  }
+
+  const int spill_mask =
+      (lr.bit() | r6.bit() | r5.bit() | r4.bit() | r3.bit() |
+       r2.bit() | r1.bit() | r0.bit());
+
+  __ stm(db_w, sp, spill_mask);
+  __ ldr(r0, FieldMemOperand(receiver, JSObject::kPropertiesOffset));
+  __ mov(r1, Operand(Handle<String>(name)));
+  StringDictionaryLookupStub stub(NEGATIVE_LOOKUP);
+  __ CallStub(&stub);
+  __ tst(r0, Operand(r0));
+  __ ldm(ia_w, sp, spill_mask);
+
+  __ b(eq, done);
+  __ b(ne, miss);
+}
+
+
+// TODO(kmillikin): Eliminate this function when the stub cache is fully
+// handlified.
+MaybeObject* StringDictionaryLookupStub::TryGenerateNegativeLookup(
     MacroAssembler* masm,
     Label* miss,
     Label* done,
@@ -6927,6 +7011,13 @@
   { r3, r1, r2, EMIT_REMEMBERED_SET },
   // KeyedStoreStubCompiler::GenerateStoreFastElement.
   { r4, r2, r3, EMIT_REMEMBERED_SET },
+  // ElementsTransitionGenerator::GenerateSmiOnlyToObject
+  // and ElementsTransitionGenerator::GenerateSmiOnlyToDouble
+  // and ElementsTransitionGenerator::GenerateDoubleToObject
+  { r2, r3, r9, EMIT_REMEMBERED_SET },
+  // ElementsTransitionGenerator::GenerateDoubleToObject
+  { r6, r2, r0, EMIT_REMEMBERED_SET },
+  { r2, r6, r9, EMIT_REMEMBERED_SET },
   // Null termination.
   { no_reg, no_reg, no_reg, EMIT_REMEMBERED_SET}
 };
@@ -7163,7 +7254,6 @@
   // Fall through when we need to inform the incremental marker.
 }
 
-
 #undef __
 
 } }  // namespace v8::internal
diff --git a/src/arm/code-stubs-arm.h b/src/arm/code-stubs-arm.h
index 3ba75ba..647fc8d 100644
--- a/src/arm/code-stubs-arm.h
+++ b/src/arm/code-stubs-arm.h
@@ -799,7 +799,17 @@
 
   void Generate(MacroAssembler* masm);
 
-  MUST_USE_RESULT static MaybeObject* GenerateNegativeLookup(
+  static void GenerateNegativeLookup(MacroAssembler* masm,
+                                     Label* miss,
+                                     Label* done,
+                                     Register receiver,
+                                     Register properties,
+                                     Handle<String> name,
+                                     Register scratch0);
+
+  // TODO(kmillikin): Eliminate this function when the stub cache is fully
+  // handlified.
+  MUST_USE_RESULT static MaybeObject* TryGenerateNegativeLookup(
       MacroAssembler* masm,
       Label* miss,
       Label* done,
diff --git a/src/arm/codegen-arm.cc b/src/arm/codegen-arm.cc
index 3993ed0..508d830 100644
--- a/src/arm/codegen-arm.cc
+++ b/src/arm/codegen-arm.cc
@@ -30,10 +30,13 @@
 #if defined(V8_TARGET_ARCH_ARM)
 
 #include "codegen.h"
+#include "macro-assembler.h"
 
 namespace v8 {
 namespace internal {
 
+#define __ ACCESS_MASM(masm)
+
 // -------------------------------------------------------------------------
 // Platform-specific RuntimeCallHelper functions.
 
@@ -51,6 +54,252 @@
 }
 
 
+// -------------------------------------------------------------------------
+// Code generators
+
+void ElementsTransitionGenerator::GenerateSmiOnlyToObject(
+    MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- r0    : value
+  //  -- r1    : key
+  //  -- r2    : receiver
+  //  -- lr    : return address
+  //  -- r3    : target map, scratch for subsequent call
+  //  -- r4    : scratch (elements)
+  // -----------------------------------
+  // Set transitioned map.
+  __ str(r3, FieldMemOperand(r2, HeapObject::kMapOffset));
+  __ RecordWriteField(r2,
+                      HeapObject::kMapOffset,
+                      r3,
+                      r9,
+                      kLRHasNotBeenSaved,
+                      kDontSaveFPRegs,
+                      EMIT_REMEMBERED_SET,
+                      OMIT_SMI_CHECK);
+}
+
+
+void ElementsTransitionGenerator::GenerateSmiOnlyToDouble(
+    MacroAssembler* masm, Label* fail) {
+  // ----------- S t a t e -------------
+  //  -- r0    : value
+  //  -- r1    : key
+  //  -- r2    : receiver
+  //  -- lr    : return address
+  //  -- r3    : target map, scratch for subsequent call
+  //  -- r4    : scratch (elements)
+  // -----------------------------------
+  Label loop, entry, convert_hole, gc_required;
+  bool vfp3_supported = CpuFeatures::IsSupported(VFP3);
+  __ push(lr);
+
+  __ ldr(r4, FieldMemOperand(r2, JSObject::kElementsOffset));
+  __ ldr(r5, FieldMemOperand(r4, FixedArray::kLengthOffset));
+  // r4: source FixedArray
+  // r5: number of elements (smi-tagged)
+
+  // Allocate new FixedDoubleArray.
+  __ mov(lr, Operand(FixedDoubleArray::kHeaderSize));
+  __ add(lr, lr, Operand(r5, LSL, 2));
+  __ AllocateInNewSpace(lr, r6, r7, r9, &gc_required, NO_ALLOCATION_FLAGS);
+  // r6: destination FixedDoubleArray, not tagged as heap object
+  __ LoadRoot(r9, Heap::kFixedDoubleArrayMapRootIndex);
+  __ str(r9, MemOperand(r6, HeapObject::kMapOffset));
+  // Set destination FixedDoubleArray's length.
+  __ str(r5, MemOperand(r6, FixedDoubleArray::kLengthOffset));
+  // Update receiver's map.
+
+  __ str(r3, FieldMemOperand(r2, HeapObject::kMapOffset));
+  __ RecordWriteField(r2,
+                      HeapObject::kMapOffset,
+                      r3,
+                      r9,
+                      kLRHasBeenSaved,
+                      kDontSaveFPRegs,
+                      EMIT_REMEMBERED_SET,
+                      OMIT_SMI_CHECK);
+  // Replace receiver's backing store with newly created FixedDoubleArray.
+  __ add(r3, r6, Operand(kHeapObjectTag));
+  __ str(r3, FieldMemOperand(r2, JSObject::kElementsOffset));
+  __ RecordWriteField(r2,
+                      JSObject::kElementsOffset,
+                      r3,
+                      r9,
+                      kLRHasBeenSaved,
+                      kDontSaveFPRegs,
+                      EMIT_REMEMBERED_SET,
+                      OMIT_SMI_CHECK);
+
+  // Prepare for conversion loop.
+  __ add(r3, r4, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+  __ add(r7, r6, Operand(FixedDoubleArray::kHeaderSize));
+  __ add(r6, r7, Operand(r5, LSL, 2));
+  __ mov(r4, Operand(kHoleNanLower32));
+  __ mov(r5, Operand(kHoleNanUpper32));
+  // r3: begin of source FixedArray element fields, not tagged
+  // r4: kHoleNanLower32
+  // r5: kHoleNanUpper32
+  // r6: end of destination FixedDoubleArray, not tagged
+  // r7: begin of FixedDoubleArray element fields, not tagged
+  if (!vfp3_supported) __ Push(r1, r0);
+
+  __ b(&entry);
+
+  // Call into runtime if GC is required.
+  __ bind(&gc_required);
+  __ pop(lr);
+  __ b(fail);
+
+  // Convert and copy elements.
+  __ bind(&loop);
+  __ ldr(r9, MemOperand(r3, 4, PostIndex));
+  // r9: current element
+  __ JumpIfNotSmi(r9, &convert_hole);
+
+  // Normal smi, convert to double and store.
+  __ SmiUntag(r9);
+  if (vfp3_supported) {
+    CpuFeatures::Scope scope(VFP3);
+    __ vmov(s0, r9);
+    __ vcvt_f64_s32(d0, s0);
+    __ vstr(d0, r7, 0);
+    __ add(r7, r7, Operand(8));
+  } else {
+    FloatingPointHelper::ConvertIntToDouble(masm,
+                                            r9,
+                                            FloatingPointHelper::kCoreRegisters,
+                                            d0,
+                                            r0,
+                                            r1,
+                                            lr,
+                                            s0);
+    __ Strd(r0, r1, MemOperand(r7, 8, PostIndex));
+  }
+  __ b(&entry);
+
+  // Hole found, store the-hole NaN.
+  __ bind(&convert_hole);
+  __ Strd(r4, r5, MemOperand(r7, 8, PostIndex));
+
+  __ bind(&entry);
+  __ cmp(r7, r6);
+  __ b(lt, &loop);
+
+  if (!vfp3_supported) __ Pop(r1, r0);
+  __ pop(lr);
+}
+
+
+void ElementsTransitionGenerator::GenerateDoubleToObject(
+    MacroAssembler* masm, Label* fail) {
+  // ----------- S t a t e -------------
+  //  -- r0    : value
+  //  -- r1    : key
+  //  -- r2    : receiver
+  //  -- lr    : return address
+  //  -- r3    : target map, scratch for subsequent call
+  //  -- r4    : scratch (elements)
+  // -----------------------------------
+  Label entry, loop, convert_hole, gc_required;
+
+  __ push(lr);
+  __ Push(r3, r2, r1, r0);
+
+  __ ldr(r4, FieldMemOperand(r2, JSObject::kElementsOffset));
+  __ ldr(r5, FieldMemOperand(r4, FixedArray::kLengthOffset));
+  // r4: source FixedDoubleArray
+  // r5: number of elements (smi-tagged)
+
+  // Allocate new FixedArray.
+  __ mov(r0, Operand(FixedDoubleArray::kHeaderSize));
+  __ add(r0, r0, Operand(r5, LSL, 1));
+  __ AllocateInNewSpace(r0, r6, r7, r9, &gc_required, NO_ALLOCATION_FLAGS);
+  // r6: destination FixedArray, not tagged as heap object
+  __ LoadRoot(r9, Heap::kFixedArrayMapRootIndex);
+  __ str(r9, MemOperand(r6, HeapObject::kMapOffset));
+  // Set destination FixedDoubleArray's length.
+  __ str(r5, MemOperand(r6, FixedDoubleArray::kLengthOffset));
+
+  // Prepare for conversion loop.
+  __ add(r4, r4, Operand(FixedDoubleArray::kHeaderSize - kHeapObjectTag + 4));
+  __ add(r3, r6, Operand(FixedArray::kHeaderSize));
+  __ add(r6, r6, Operand(kHeapObjectTag));
+  __ add(r5, r3, Operand(r5, LSL, 1));
+  __ LoadRoot(r7, Heap::kTheHoleValueRootIndex);
+  __ LoadRoot(r9, Heap::kHeapNumberMapRootIndex);
+  // Using offsetted addresses in r4 to fully take advantage of post-indexing.
+  // r3: begin of destination FixedArray element fields, not tagged
+  // r4: begin of source FixedDoubleArray element fields, not tagged, +4
+  // r5: end of destination FixedArray, not tagged
+  // r6: destination FixedArray
+  // r7: the-hole pointer
+  // r9: heap number map
+  __ b(&entry);
+
+  // Call into runtime if GC is required.
+  __ bind(&gc_required);
+  __ Pop(r3, r2, r1, r0);
+  __ pop(lr);
+  __ b(fail);
+
+  __ bind(&loop);
+  __ ldr(r1, MemOperand(r4, 8, PostIndex));
+  // lr: current element's upper 32 bit
+  // r4: address of next element's upper 32 bit
+  __ cmp(r1, Operand(kHoleNanUpper32));
+  __ b(eq, &convert_hole);
+
+  // Non-hole double, copy value into a heap number.
+  __ AllocateHeapNumber(r2, r0, lr, r9, &gc_required);
+  // r2: new heap number
+  __ ldr(r0, MemOperand(r4, 12, NegOffset));
+  __ Strd(r0, r1, FieldMemOperand(r2, HeapNumber::kValueOffset));
+  __ mov(r0, r3);
+  __ str(r2, MemOperand(r3, 4, PostIndex));
+  __ RecordWrite(r6,
+                 r0,
+                 r2,
+                 kLRHasBeenSaved,
+                 kDontSaveFPRegs,
+                 EMIT_REMEMBERED_SET,
+                 OMIT_SMI_CHECK);
+  __ b(&entry);
+
+  // Replace the-hole NaN with the-hole pointer.
+  __ bind(&convert_hole);
+  __ str(r7, MemOperand(r3, 4, PostIndex));
+
+  __ bind(&entry);
+  __ cmp(r3, r5);
+  __ b(lt, &loop);
+
+  __ Pop(r3, r2, r1, r0);
+  // Update receiver's map.
+  __ str(r3, FieldMemOperand(r2, HeapObject::kMapOffset));
+  __ RecordWriteField(r2,
+                      HeapObject::kMapOffset,
+                      r3,
+                      r9,
+                      kLRHasBeenSaved,
+                      kDontSaveFPRegs,
+                      EMIT_REMEMBERED_SET,
+                      OMIT_SMI_CHECK);
+  // Replace receiver's backing store with newly created and filled FixedArray.
+  __ str(r6, FieldMemOperand(r2, JSObject::kElementsOffset));
+  __ RecordWriteField(r2,
+                      JSObject::kElementsOffset,
+                      r6,
+                      r9,
+                      kLRHasBeenSaved,
+                      kDontSaveFPRegs,
+                      EMIT_REMEMBERED_SET,
+                      OMIT_SMI_CHECK);
+  __ pop(lr);
+}
+
+#undef __
+
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM
diff --git a/src/arm/codegen-arm.h b/src/arm/codegen-arm.h
index 1c0d508..f54231c 100644
--- a/src/arm/codegen-arm.h
+++ b/src/arm/codegen-arm.h
@@ -29,7 +29,6 @@
 #define V8_ARM_CODEGEN_ARM_H_
 
 #include "ast.h"
-#include "code-stubs-arm.h"
 #include "ic-inl.h"
 
 namespace v8 {
diff --git a/src/arm/deoptimizer-arm.cc b/src/arm/deoptimizer-arm.cc
index bb03d74..8505c7d 100644
--- a/src/arm/deoptimizer-arm.cc
+++ b/src/arm/deoptimizer-arm.cc
@@ -100,7 +100,6 @@
     }
   }
 
-
 #ifdef DEBUG
   // Destroy the code which is not supposed to be run again.
   int instructions =
@@ -178,16 +177,13 @@
   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);
+  unoptimized_code->GetHeap()->incremental_marking()->RecordCodeTargetPatch(
+      unoptimized_code, pc_after - 2 * kInstrSize, replacement_code);
 }
 
 
-void Deoptimizer::RevertStackCheckCodeAt(Address pc_after,
+void Deoptimizer::RevertStackCheckCodeAt(Code* unoptimized_code,
+                                         Address pc_after,
                                          Code* check_code,
                                          Code* replacement_code) {
   const int kInstrSize = Assembler::kInstrSize;
@@ -209,8 +205,8 @@
   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);
+  check_code->GetHeap()->incremental_marking()->RecordCodeTargetPatch(
+      unoptimized_code, pc_after - 2 * kInstrSize, check_code);
 }
 
 
@@ -727,7 +723,6 @@
   __ ldr(r3, MemOperand(r2, FrameDescription::frame_size_offset()));
   __ bind(&inner_push_loop);
   __ sub(r3, r3, Operand(sizeof(uint32_t)));
-  // __ add(r6, r2, Operand(r3, LSL, 1));
   __ add(r6, r2, Operand(r3));
   __ ldr(r7, MemOperand(r6, FrameDescription::frame_content_offset()));
   __ push(r7);
@@ -761,8 +756,9 @@
   __ pop(ip);  // remove lr
 
   // Set up the roots register.
-  ExternalReference roots_address = ExternalReference::roots_address(isolate);
-  __ mov(r10, Operand(roots_address));
+  ExternalReference roots_array_start =
+      ExternalReference::roots_array_start(isolate);
+  __ mov(r10, Operand(roots_array_start));
 
   __ pop(ip);  // remove pc
   __ pop(r7);  // get continuation, leave pc on stack
diff --git a/src/arm/full-codegen-arm.cc b/src/arm/full-codegen-arm.cc
index 353ce5b..497a295 100644
--- a/src/arm/full-codegen-arm.cc
+++ b/src/arm/full-codegen-arm.cc
@@ -269,7 +269,10 @@
       // constant.
       if (scope()->is_function_scope() && scope()->function() != NULL) {
         int ignored = 0;
-        EmitDeclaration(scope()->function(), CONST, NULL, &ignored);
+        VariableProxy* proxy = scope()->function();
+        ASSERT(proxy->var()->mode() == CONST ||
+               proxy->var()->mode() == CONST_HARMONY);
+        EmitDeclaration(proxy, proxy->var()->mode(), NULL, &ignored);
       }
       VisitDeclarations(scope()->declarations());
     }
@@ -718,6 +721,8 @@
   // need to "declare" it at runtime to make sure it actually exists in the
   // local context.
   Variable* variable = proxy->var();
+  bool binding_needs_init =
+      mode == CONST || mode == CONST_HARMONY || mode == LET;
   switch (variable->location()) {
     case Variable::UNALLOCATED:
       ++(*global_count);
@@ -729,7 +734,7 @@
         Comment cmnt(masm_, "[ Declaration");
         VisitForAccumulatorValue(function);
         __ str(result_register(), StackOperand(variable));
-      } else if (mode == CONST || mode == LET) {
+      } else if (binding_needs_init) {
         Comment cmnt(masm_, "[ Declaration");
         __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
         __ str(ip, StackOperand(variable));
@@ -763,7 +768,7 @@
                                   EMIT_REMEMBERED_SET,
                                   OMIT_SMI_CHECK);
         PrepareForBailoutForId(proxy->id(), NO_REGISTERS);
-      } else if (mode == CONST || mode == LET) {
+      } else if (binding_needs_init) {
         Comment cmnt(masm_, "[ Declaration");
         __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
         __ str(ip, ContextOperand(cp, variable->index()));
@@ -775,9 +780,13 @@
     case Variable::LOOKUP: {
       Comment cmnt(masm_, "[ Declaration");
       __ mov(r2, Operand(variable->name()));
-      // Declaration nodes are always introduced in one of three modes.
-      ASSERT(mode == VAR || mode == CONST || mode == LET);
-      PropertyAttributes attr = (mode == CONST) ? READ_ONLY : NONE;
+      // Declaration nodes are always introduced in one of four modes.
+      ASSERT(mode == VAR ||
+             mode == CONST ||
+             mode == CONST_HARMONY ||
+             mode == LET);
+      PropertyAttributes attr = (mode == CONST || mode == CONST_HARMONY)
+          ? 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
@@ -787,7 +796,7 @@
         __ Push(cp, r2, r1);
         // Push initial value for function declaration.
         VisitForStackValue(function);
-      } else if (mode == CONST || mode == LET) {
+      } else if (binding_needs_init) {
         __ LoadRoot(r0, Heap::kTheHoleValueRootIndex);
         __ Push(cp, r2, r1, r0);
       } else {
@@ -929,11 +938,17 @@
   __ bind(&done_convert);
   __ push(r0);
 
+  // Check for proxies.
+  Label call_runtime;
+  STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
+  __ CompareObjectType(r0, r1, r1, LAST_JS_PROXY_TYPE);
+  __ b(le, &call_runtime);
+
   // Check cache validity in generated code. This is a fast case for
   // the JSObject::IsSimpleEnum cache validity checks. If we cannot
   // guarantee cache validity, call the runtime system to check cache
   // validity or get the property names in a fixed array.
-  Label next, call_runtime;
+  Label next;
   // Preload a couple of values used in the loop.
   Register  empty_fixed_array_value = r6;
   __ LoadRoot(empty_fixed_array_value, Heap::kEmptyFixedArrayRootIndex);
@@ -1012,9 +1027,16 @@
   __ jmp(&loop);
 
   // We got a fixed array in register r0. Iterate through that.
+  Label non_proxy;
   __ bind(&fixed_array);
-  __ mov(r1, Operand(Smi::FromInt(0)));  // Map (0) - force slow check.
-  __ Push(r1, r0);
+  __ mov(r1, Operand(Smi::FromInt(1)));  // Smi indicates slow check
+  __ ldr(r2, MemOperand(sp, 0 * kPointerSize));  // Get enumerated object
+  STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
+  __ CompareObjectType(r2, r3, r3, LAST_JS_PROXY_TYPE);
+  __ b(gt, &non_proxy);
+  __ mov(r1, Operand(Smi::FromInt(0)));  // Zero indicates proxy
+  __ bind(&non_proxy);
+  __ Push(r1, r0);  // Smi and array
   __ ldr(r1, FieldMemOperand(r0, FixedArray::kLengthOffset));
   __ mov(r0, Operand(Smi::FromInt(0)));
   __ Push(r1, r0);  // Fixed array length (as smi) and initial index.
@@ -1031,18 +1053,23 @@
   __ add(r2, r2, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
   __ ldr(r3, MemOperand(r2, r0, LSL, kPointerSizeLog2 - kSmiTagSize));
 
-  // Get the expected map from the stack or a zero map in the
+  // Get the expected map from the stack or a smi in the
   // permanent slow case into register r2.
   __ ldr(r2, MemOperand(sp, 3 * kPointerSize));
 
   // Check if the expected map still matches that of the enumerable.
-  // If not, we have to filter the key.
+  // If not, we may have to filter the key.
   Label update_each;
   __ ldr(r1, MemOperand(sp, 4 * kPointerSize));
   __ ldr(r4, FieldMemOperand(r1, HeapObject::kMapOffset));
   __ cmp(r4, Operand(r2));
   __ b(eq, &update_each);
 
+  // For proxies, no filtering is done.
+  // TODO(rossberg): What if only a prototype is a proxy? Not specified yet.
+  __ cmp(r2, Operand(Smi::FromInt(0)));
+  __ b(eq, &update_each);
+
   // Convert the entry to a string or (smi) 0 if it isn't a property
   // any more. If the property has been removed while iterating, we
   // just skip it.
@@ -1097,7 +1124,7 @@
       !pretenure &&
       scope()->is_function_scope() &&
       info->num_literals() == 0) {
-    FastNewClosureStub stub(info->strict_mode() ? kStrictMode : kNonStrictMode);
+    FastNewClosureStub stub(info->strict_mode_flag());
     __ mov(r0, Operand(info));
     __ push(r0);
     __ CallStub(&stub);
@@ -1128,7 +1155,7 @@
   Scope* s = scope();
   while (s != NULL) {
     if (s->num_heap_slots() > 0) {
-      if (s->calls_eval()) {
+      if (s->calls_non_strict_eval()) {
         // Check that extension is NULL.
         __ ldr(temp, ContextOperand(current, Context::EXTENSION_INDEX));
         __ tst(temp, temp);
@@ -1141,7 +1168,7 @@
     }
     // If no outer scope calls eval, we do not need to check more
     // context extensions.
-    if (!s->outer_scope_calls_eval() || s->is_eval_scope()) break;
+    if (!s->outer_scope_calls_non_strict_eval() || s->is_eval_scope()) break;
     s = s->outer_scope();
   }
 
@@ -1185,7 +1212,7 @@
 
   for (Scope* s = scope(); s != var->scope(); s = s->outer_scope()) {
     if (s->num_heap_slots() > 0) {
-      if (s->calls_eval()) {
+      if (s->calls_non_strict_eval()) {
         // Check that extension is NULL.
         __ ldr(temp, ContextOperand(context, Context::EXTENSION_INDEX));
         __ tst(temp, temp);
@@ -1224,11 +1251,12 @@
     Variable* local = var->local_if_not_shadowed();
     __ ldr(r0, ContextSlotOperandCheckExtensions(local, slow));
     if (local->mode() == CONST ||
+        local->mode() == CONST_HARMONY ||
         local->mode() == LET) {
       __ CompareRoot(r0, Heap::kTheHoleValueRootIndex);
       if (local->mode() == CONST) {
         __ LoadRoot(r0, Heap::kUndefinedValueRootIndex, eq);
-      } else {  // LET
+      } else {  // LET || CONST_HARMONY
         __ b(ne, done);
         __ mov(r0, Operand(var->name()));
         __ push(r0);
@@ -1266,13 +1294,15 @@
       Comment cmnt(masm_, var->IsContextSlot()
                               ? "Context variable"
                               : "Stack variable");
-      if (var->mode() != LET && var->mode() != CONST) {
+      if (!var->binding_needs_init()) {
         context()->Plug(var);
       } else {
         // Let and const need a read barrier.
         GetVar(r0, var);
         __ CompareRoot(r0, Heap::kTheHoleValueRootIndex);
-        if (var->mode() == LET) {
+        if (var->mode() == LET || var->mode() == CONST_HARMONY) {
+          // Throw a reference error when using an uninitialized let/const
+          // binding in harmony mode.
           Label done;
           __ b(ne, &done);
           __ mov(r0, Operand(var->name()));
@@ -1280,6 +1310,8 @@
           __ CallRuntime(Runtime::kThrowReferenceError, 1);
           __ bind(&done);
         } else {
+          // Uninitalized const bindings outside of harmony mode are unholed.
+          ASSERT(var->mode() == CONST);
           __ LoadRoot(r0, Heap::kUndefinedValueRootIndex, eq);
         }
         context()->Plug(r0);
@@ -1467,13 +1499,19 @@
 
   ZoneList<Expression*>* subexprs = expr->values();
   int length = subexprs->length();
+  Handle<FixedArray> constant_elements = expr->constant_elements();
+  ASSERT_EQ(2, constant_elements->length());
+  ElementsKind constant_elements_kind =
+      static_cast<ElementsKind>(Smi::cast(constant_elements->get(0))->value());
+  Handle<FixedArrayBase> constant_elements_values(
+      FixedArrayBase::cast(constant_elements->get(1)));
 
   __ ldr(r3, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
   __ ldr(r3, FieldMemOperand(r3, JSFunction::kLiteralsOffset));
   __ mov(r2, Operand(Smi::FromInt(expr->literal_index())));
-  __ mov(r1, Operand(expr->constant_elements()));
+  __ mov(r1, Operand(constant_elements));
   __ Push(r3, r2, r1);
-  if (expr->constant_elements()->map() ==
+  if (constant_elements_values->map() ==
       isolate()->heap()->fixed_cow_array_map()) {
     FastCloneShallowArrayStub stub(
         FastCloneShallowArrayStub::COPY_ON_WRITE_ELEMENTS, length);
@@ -1485,8 +1523,14 @@
   } else if (length > FastCloneShallowArrayStub::kMaximumClonedLength) {
     __ CallRuntime(Runtime::kCreateArrayLiteralShallow, 3);
   } else {
-    FastCloneShallowArrayStub stub(
-        FastCloneShallowArrayStub::CLONE_ELEMENTS, length);
+    ASSERT(constant_elements_kind == FAST_ELEMENTS ||
+           constant_elements_kind == FAST_SMI_ONLY_ELEMENTS ||
+           FLAG_smi_only_arrays);
+    FastCloneShallowArrayStub::Mode mode =
+        constant_elements_kind == FAST_DOUBLE_ELEMENTS
+        ? FastCloneShallowArrayStub::CLONE_DOUBLE_ELEMENTS
+        : FastCloneShallowArrayStub::CLONE_ELEMENTS;
+    FastCloneShallowArrayStub stub(mode, length);
     __ CallStub(&stub);
   }
 
@@ -1509,24 +1553,56 @@
     }
     VisitForAccumulatorValue(subexpr);
 
-    // Store the subexpression value in the array's elements.
     __ ldr(r6, MemOperand(sp));  // Copy of array literal.
     __ ldr(r1, FieldMemOperand(r6, JSObject::kElementsOffset));
+    __ ldr(r2, FieldMemOperand(r6, JSObject::kMapOffset));
     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.
+    Label element_done;
+    Label double_elements;
+    Label smi_element;
+    Label slow_elements;
+    Label fast_elements;
+    __ CheckFastElements(r2, r3, &double_elements);
+
+    // FAST_SMI_ONLY_ELEMENTS or FAST_ELEMENTS
+    __ JumpIfSmi(result_register(), &smi_element);
+    __ CheckFastSmiOnlyElements(r2, r3, &fast_elements);
+
+    // Store into the array literal requires a elements transition. Call into
+    // the runtime.
+    __ bind(&slow_elements);
+    __ push(r6);  // Copy of array literal.
+    __ mov(r1, Operand(Smi::FromInt(i)));
+    __ mov(r2, Operand(Smi::FromInt(NONE)));  // PropertyAttributes
+    __ mov(r3, Operand(Smi::FromInt(strict_mode_flag())));  // Strict mode.
+    __ Push(r1, result_register(), r2, r3);
+    __ CallRuntime(Runtime::kSetProperty, 5);
+    __ b(&element_done);
+
+      // Array literal has ElementsKind of FAST_DOUBLE_ELEMENTS.
+    __ bind(&double_elements);
+    __ mov(r3, Operand(Smi::FromInt(i)));
+    __ StoreNumberToDoubleElements(result_register(), r3, r6, r1, r4, r5, r9,
+                                   r7, &slow_elements);
+    __ b(&element_done);
+
+    // Array literal has ElementsKind of FAST_ELEMENTS and value is an object.
+    __ bind(&fast_elements);
+    __ str(result_register(), FieldMemOperand(r1, offset));
+    // Update the write barrier for the array store.
     __ 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);
+    __ b(&element_done);
+
+    // Array literal has ElementsKind of FAST_SMI_ONLY_ELEMENTS or
+    // FAST_ELEMENTS, and value is Smi.
+    __ bind(&smi_element);
+    __ str(result_register(), FieldMemOperand(r1, offset));
+    // Fall through
+
+    __ bind(&element_done);
 
     PrepareForBailoutForId(expr->GetIdForElement(i), NO_REGISTERS);
   }
@@ -1903,8 +1979,9 @@
       }
     }
 
-  } else if (var->mode() != CONST) {
-    // Assignment to var or initializing assignment to let.
+  } else if (!var->is_const_mode() || op == Token::INIT_CONST_HARMONY) {
+    // Assignment to var or initializing assignment to let/const
+    // in harmony mode.
     if (var->IsStackAllocated() || var->IsContextSlot()) {
       MemOperand location = VarOperand(var, r1);
       if (FLAG_debug_code && op == Token::INIT_LET) {
@@ -2784,7 +2861,8 @@
   // ( 1.(20 0s)(32 random bits) x 2^20 ) - (1.0 x 2^20)).
   if (CpuFeatures::IsSupported(VFP3)) {
     __ PrepareCallCFunction(1, r0);
-    __ mov(r0, Operand(ExternalReference::isolate_address()));
+    __ ldr(r0, ContextOperand(context_register(), Context::GLOBAL_INDEX));
+    __ ldr(r0, FieldMemOperand(r0, GlobalObject::kGlobalContextOffset));
     __ CallCFunction(ExternalReference::random_uint32_function(isolate()), 1);
 
     CpuFeatures::Scope scope(VFP3);
@@ -2804,8 +2882,9 @@
     __ mov(r0, r4);
   } else {
     __ PrepareCallCFunction(2, r0);
+    __ ldr(r1, ContextOperand(context_register(), Context::GLOBAL_INDEX));
     __ mov(r0, Operand(r4));
-    __ mov(r1, Operand(ExternalReference::isolate_address()));
+    __ ldr(r1, FieldMemOperand(r1, GlobalObject::kGlobalContextOffset));
     __ CallCFunction(
         ExternalReference::fill_heap_number_with_random_function(isolate()), 2);
   }
@@ -4071,33 +4150,25 @@
         case Token::EQ_STRICT:
         case Token::EQ:
           cond = eq;
-          __ pop(r1);
           break;
         case Token::LT:
           cond = lt;
-          __ pop(r1);
           break;
         case Token::GT:
-          // Reverse left and right sides to obtain ECMA-262 conversion order.
-          cond = lt;
-          __ mov(r1, result_register());
-          __ pop(r0);
+          cond = gt;
          break;
         case Token::LTE:
-          // Reverse left and right sides to obtain ECMA-262 conversion order.
-          cond = ge;
-          __ mov(r1, result_register());
-          __ pop(r0);
+          cond = le;
           break;
         case Token::GTE:
           cond = ge;
-          __ pop(r1);
           break;
         case Token::IN:
         case Token::INSTANCEOF:
         default:
           UNREACHABLE();
       }
+      __ pop(r1);
 
       bool inline_smi_code = ShouldInlineSmiCase(op);
       JumpPatchSite patch_site(masm_);
diff --git a/src/arm/ic-arm.cc b/src/arm/ic-arm.cc
index 6e0badc..18d4a9f 100644
--- a/src/arm/ic-arm.cc
+++ b/src/arm/ic-arm.cc
@@ -382,10 +382,10 @@
 
 // The generated code does not accept smi keys.
 // The generated code falls through if both probes miss.
-static void GenerateMonomorphicCacheProbe(MacroAssembler* masm,
-                                          int argc,
-                                          Code::Kind kind,
-                                          Code::ExtraICState extra_ic_state) {
+void CallICBase::GenerateMonomorphicCacheProbe(MacroAssembler* masm,
+                                               int argc,
+                                               Code::Kind kind,
+                                               Code::ExtraICState extra_state) {
   // ----------- S t a t e -------------
   //  -- r1    : receiver
   //  -- r2    : name
@@ -395,7 +395,7 @@
   // Probe the stub cache.
   Code::Flags flags = Code::ComputeFlags(kind,
                                          MONOMORPHIC,
-                                         extra_ic_state,
+                                         extra_state,
                                          NORMAL,
                                          argc);
   Isolate::Current()->stub_cache()->GenerateProbe(
@@ -464,7 +464,7 @@
 }
 
 
-static void GenerateCallNormal(MacroAssembler* masm, int argc) {
+void CallICBase::GenerateNormal(MacroAssembler* masm, int argc) {
   // ----------- S t a t e -------------
   //  -- r2    : name
   //  -- lr    : return address
@@ -486,10 +486,10 @@
 }
 
 
-static void GenerateCallMiss(MacroAssembler* masm,
-                             int argc,
-                             IC::UtilityId id,
-                             Code::ExtraICState extra_ic_state) {
+void CallICBase::GenerateMiss(MacroAssembler* masm,
+                              int argc,
+                              IC::UtilityId id,
+                              Code::ExtraICState extra_state) {
   // ----------- S t a t e -------------
   //  -- r2    : name
   //  -- lr    : return address
@@ -541,7 +541,7 @@
   }
 
   // Invoke the function.
-  CallKind call_kind = CallICBase::Contextual::decode(extra_ic_state)
+  CallKind call_kind = CallICBase::Contextual::decode(extra_state)
       ? CALL_AS_FUNCTION
       : CALL_AS_METHOD;
   ParameterCount actual(argc);
@@ -553,18 +553,6 @@
 }
 
 
-void CallIC::GenerateMiss(MacroAssembler* masm,
-                          int argc,
-                          Code::ExtraICState extra_ic_state) {
-  // ----------- S t a t e -------------
-  //  -- r2    : name
-  //  -- lr    : return address
-  // -----------------------------------
-
-  GenerateCallMiss(masm, argc, IC::kCallIC_Miss, extra_ic_state);
-}
-
-
 void CallIC::GenerateMegamorphic(MacroAssembler* masm,
                                  int argc,
                                  Code::ExtraICState extra_ic_state) {
@@ -580,27 +568,6 @@
 }
 
 
-void CallIC::GenerateNormal(MacroAssembler* masm, int argc) {
-  // ----------- S t a t e -------------
-  //  -- r2    : name
-  //  -- lr    : return address
-  // -----------------------------------
-
-  GenerateCallNormal(masm, argc);
-  GenerateMiss(masm, argc, Code::kNoExtraICState);
-}
-
-
-void KeyedCallIC::GenerateMiss(MacroAssembler* masm, int argc) {
-  // ----------- S t a t e -------------
-  //  -- r2    : name
-  //  -- lr    : return address
-  // -----------------------------------
-
-  GenerateCallMiss(masm, argc, IC::kKeyedCallIC_Miss, Code::kNoExtraICState);
-}
-
-
 void KeyedCallIC::GenerateMegamorphic(MacroAssembler* masm, int argc) {
   // ----------- S t a t e -------------
   //  -- r2    : name
@@ -718,7 +685,7 @@
   __ JumpIfSmi(r2, &miss);
   __ IsObjectJSStringType(r2, r0, &miss);
 
-  GenerateCallNormal(masm, argc);
+  CallICBase::GenerateNormal(masm, argc);
   __ bind(&miss);
   GenerateMiss(masm, argc);
 }
@@ -1244,6 +1211,47 @@
 }
 
 
+void KeyedStoreIC::GenerateTransitionElementsSmiToDouble(MacroAssembler* masm) {
+  // ---------- S t a t e --------------
+  //  -- r2     : receiver
+  //  -- r3     : target map
+  //  -- lr     : return address
+  // -----------------------------------
+  // Must return the modified receiver in r0.
+  if (!FLAG_trace_elements_transitions) {
+    Label fail;
+    ElementsTransitionGenerator::GenerateSmiOnlyToDouble(masm, &fail);
+    __ mov(r0, r2);
+    __ Ret();
+    __ bind(&fail);
+  }
+
+  __ push(r2);
+  __ TailCallRuntime(Runtime::kTransitionElementsSmiToDouble, 1, 1);
+}
+
+
+void KeyedStoreIC::GenerateTransitionElementsDoubleToObject(
+    MacroAssembler* masm) {
+  // ---------- S t a t e --------------
+  //  -- r2     : receiver
+  //  -- r3     : target map
+  //  -- lr     : return address
+  // -----------------------------------
+  // Must return the modified receiver in r0.
+  if (!FLAG_trace_elements_transitions) {
+    Label fail;
+    ElementsTransitionGenerator::GenerateDoubleToObject(masm, &fail);
+    __ mov(r0, r2);
+    __ Ret();
+    __ bind(&fail);
+  }
+
+  __ push(r2);
+  __ TailCallRuntime(Runtime::kTransitionElementsDoubleToObject, 1, 1);
+}
+
+
 void KeyedStoreIC::GenerateRuntimeSetProperty(MacroAssembler* masm,
                                               StrictModeFlag strict_mode) {
   // ---------- S t a t e --------------
@@ -1559,11 +1567,9 @@
     case Token::LT:
       return lt;
     case Token::GT:
-      // Reverse left and right operands to obtain ECMA-262 conversion order.
-      return lt;
+      return gt;
     case Token::LTE:
-      // Reverse left and right operands to obtain ECMA-262 conversion order.
-      return ge;
+      return le;
     case Token::GTE:
       return ge;
     default:
diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc
index 8495939..5197842 100644
--- a/src/arm/lithium-arm.cc
+++ b/src/arm/lithium-arm.cc
@@ -391,6 +391,12 @@
 }
 
 
+void LTransitionElementsKind::PrintDataTo(StringStream* stream) {
+  object()->PrintTo(stream);
+  stream->Add(" %p -> %p", *original_map(), *transitioned_map());
+}
+
+
 LChunk::LChunk(CompilationInfo* info, HGraph* graph)
     : spill_slot_count_(0),
       info_(info),
@@ -1404,12 +1410,10 @@
 
 
 LInstruction* LChunkBuilder::DoCompareGeneric(HCompareGeneric* instr) {
-  Token::Value op = instr->token();
   ASSERT(instr->left()->representation().IsTagged());
   ASSERT(instr->right()->representation().IsTagged());
-  bool reversed = (op == Token::GT || op == Token::LTE);
-  LOperand* left = UseFixed(instr->left(), reversed ? r0 : r1);
-  LOperand* right = UseFixed(instr->right(), reversed ? r1 : r0);
+  LOperand* left = UseFixed(instr->left(), r1);
+  LOperand* right = UseFixed(instr->right(), r0);
   LCmpT* result = new LCmpT(left, right);
   return MarkAsCall(DefineFixed(result, r0), instr);
 }
@@ -1421,8 +1425,8 @@
   if (r.IsInteger32()) {
     ASSERT(instr->left()->representation().IsInteger32());
     ASSERT(instr->right()->representation().IsInteger32());
-    LOperand* left = UseRegisterAtStart(instr->left());
-    LOperand* right = UseRegisterAtStart(instr->right());
+    LOperand* left = UseRegisterOrConstantAtStart(instr->left());
+    LOperand* right = UseRegisterOrConstantAtStart(instr->right());
     return new LCmpIDAndBranch(left, right);
   } else {
     ASSERT(r.IsDouble());
@@ -1970,6 +1974,26 @@
 }
 
 
+LInstruction* LChunkBuilder::DoTransitionElementsKind(
+    HTransitionElementsKind* instr) {
+  if (instr->original_map()->elements_kind() == FAST_SMI_ONLY_ELEMENTS &&
+      instr->transitioned_map()->elements_kind() == FAST_ELEMENTS) {
+    LOperand* object = UseRegister(instr->object());
+    LOperand* new_map_reg = TempRegister();
+    LTransitionElementsKind* result =
+        new LTransitionElementsKind(object, new_map_reg, NULL);
+    return DefineSameAsFirst(result);
+  } else {
+    LOperand* object = UseFixed(instr->object(), r0);
+    LOperand* fixed_object_reg = FixedTemp(r2);
+    LOperand* new_map_reg = FixedTemp(r3);
+    LTransitionElementsKind* result =
+        new LTransitionElementsKind(object, new_map_reg, fixed_object_reg);
+    return MarkAsCall(DefineFixed(result, r0), instr);
+  }
+}
+
+
 LInstruction* LChunkBuilder::DoStoreNamedField(HStoreNamedField* instr) {
   bool needs_write_barrier = instr->NeedsWriteBarrier();
 
diff --git a/src/arm/lithium-arm.h b/src/arm/lithium-arm.h
index 73c7e45..5733bd0 100644
--- a/src/arm/lithium-arm.h
+++ b/src/arm/lithium-arm.h
@@ -162,6 +162,7 @@
   V(ThisFunction)                               \
   V(Throw)                                      \
   V(ToFastProperties)                           \
+  V(TransitionElementsKind)                     \
   V(Typeof)                                     \
   V(TypeofIsAndBranch)                          \
   V(UnaryMathOperation)                         \
@@ -1260,7 +1261,6 @@
   LOperand* context() { return InputAt(0); }
   LOperand* value() { return InputAt(1); }
   int slot_index() { return hydrogen()->slot_index(); }
-  int needs_write_barrier() { return hydrogen()->NeedsWriteBarrier(); }
 
   virtual void PrintDataTo(StringStream* stream);
 };
@@ -1277,7 +1277,9 @@
 
 
 class LThisFunction: public LTemplateInstruction<1, 0, 0> {
+ public:
   DECLARE_CONCRETE_INSTRUCTION(ThisFunction, "this-function")
+  DECLARE_HYDROGEN_ACCESSOR(ThisFunction)
 };
 
 
@@ -1561,7 +1563,6 @@
   Handle<Object> name() const { return hydrogen()->name(); }
   bool is_in_object() { return hydrogen()->is_in_object(); }
   int offset() { return hydrogen()->offset(); }
-  bool needs_write_barrier() { return hydrogen()->NeedsWriteBarrier(); }
   Handle<Map> transition() const { return hydrogen()->transition(); }
 };
 
@@ -1581,7 +1582,8 @@
   LOperand* object() { return inputs_[0]; }
   LOperand* value() { return inputs_[1]; }
   Handle<Object> name() const { return hydrogen()->name(); }
-  bool strict_mode() { return hydrogen()->strict_mode(); }
+  StrictModeFlag strict_mode_flag() { return hydrogen()->strict_mode_flag(); }
+  bool strict_mode() { return strict_mode_flag() == kStrictMode; }
 };
 
 
@@ -1669,6 +1671,30 @@
 };
 
 
+class LTransitionElementsKind: public LTemplateInstruction<1, 1, 2> {
+ public:
+  LTransitionElementsKind(LOperand* object,
+                          LOperand* new_map_temp,
+                          LOperand* temp_reg) {
+    inputs_[0] = object;
+    temps_[0] = new_map_temp;
+    temps_[1] = temp_reg;
+  }
+
+  DECLARE_CONCRETE_INSTRUCTION(TransitionElementsKind,
+                               "transition-elements-kind")
+  DECLARE_HYDROGEN_ACCESSOR(TransitionElementsKind)
+
+  virtual void PrintDataTo(StringStream* stream);
+
+  LOperand* object() { return inputs_[0]; }
+  LOperand* new_map_reg() { return temps_[0]; }
+  LOperand* temp_reg() { return temps_[1]; }
+  Handle<Map> original_map() { return hydrogen()->original_map(); }
+  Handle<Map> transitioned_map() { return hydrogen()->transitioned_map(); }
+};
+
+
 class LStringAdd: public LTemplateInstruction<1, 2, 0> {
  public:
   LStringAdd(LOperand* left, LOperand* right) {
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 70ef884..4cf7df4 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -410,6 +410,12 @@
 }
 
 
+double LCodeGen::ToDouble(LConstantOperand* op) const {
+  Handle<Object> value = chunk_->LookupLiteral(op);
+  return value->Number();
+}
+
+
 Operand LCodeGen::ToOperand(LOperand* op) {
   if (op->IsConstantOperand()) {
     LConstantOperand* const_op = LConstantOperand::cast(op);
@@ -1705,30 +1711,44 @@
 }
 
 
-void LCodeGen::EmitCmpI(LOperand* left, LOperand* right) {
-  __ cmp(ToRegister(left), ToRegister(right));
-}
-
-
 void LCodeGen::DoCmpIDAndBranch(LCmpIDAndBranch* instr) {
   LOperand* left = instr->InputAt(0);
   LOperand* right = instr->InputAt(1);
   int false_block = chunk_->LookupDestination(instr->false_block_id());
   int true_block = chunk_->LookupDestination(instr->true_block_id());
+  Condition cond = TokenToCondition(instr->op(), false);
 
-  if (instr->is_double()) {
-    // Compare left and right as doubles and load the
-    // resulting flags into the normal status register.
-    __ VFPCompareAndSetFlags(ToDoubleRegister(left), ToDoubleRegister(right));
-    // If a NaN is involved, i.e. the result is unordered (V set),
-    // jump to false block label.
-    __ b(vs, chunk_->GetAssemblyLabel(false_block));
+  if (left->IsConstantOperand() && right->IsConstantOperand()) {
+    // We can statically evaluate the comparison.
+    double left_val = ToDouble(LConstantOperand::cast(left));
+    double right_val = ToDouble(LConstantOperand::cast(right));
+    int next_block =
+      EvalComparison(instr->op(), left_val, right_val) ? true_block
+                                                       : false_block;
+    EmitGoto(next_block);
   } else {
-    EmitCmpI(left, right);
+    if (instr->is_double()) {
+      // Compare left and right operands as doubles and load the
+      // resulting flags into the normal status register.
+      __ VFPCompareAndSetFlags(ToDoubleRegister(left), ToDoubleRegister(right));
+      // If a NaN is involved, i.e. the result is unordered (V set),
+      // jump to false block label.
+      __ b(vs, chunk_->GetAssemblyLabel(false_block));
+    } else {
+      if (right->IsConstantOperand()) {
+        __ cmp(ToRegister(left),
+               Operand(ToInteger32(LConstantOperand::cast(right))));
+      } else if (left->IsConstantOperand()) {
+        __ cmp(ToRegister(right),
+               Operand(ToInteger32(LConstantOperand::cast(left))));
+        // We transposed the operands. Reverse the condition.
+        cond = ReverseCondition(cond);
+      } else {
+        __ cmp(ToRegister(left), ToRegister(right));
+      }
+    }
+    EmitBranch(true_block, false_block, cond);
   }
-
-  Condition cc = TokenToCondition(instr->op(), instr->is_double());
-  EmitBranch(true_block, false_block, cc);
 }
 
 
@@ -2176,9 +2196,6 @@
   __ cmp(r0, Operand(0));  // This instruction also signals no smi code inlined.
 
   Condition condition = ComputeCompareCondition(op);
-  if (op == Token::GT || op == Token::LTE) {
-    condition = ReverseCondition(condition);
-  }
   __ LoadRoot(ToRegister(instr->result()),
               Heap::kTrueValueRootIndex,
               condition);
@@ -2251,13 +2268,19 @@
   __ str(value, FieldMemOperand(scratch, JSGlobalPropertyCell::kValueOffset));
 
   // Cells are always in the remembered set.
-  __ RecordWriteField(scratch,
-                      JSGlobalPropertyCell::kValueOffset,
-                      value,
-                      scratch2,
-                      kLRHasBeenSaved,
-                      kSaveFPRegs,
-                      OMIT_REMEMBERED_SET);
+  if (instr->hydrogen()->NeedsWriteBarrier()) {
+    HType type = instr->hydrogen()->value()->type();
+    SmiCheck check_needed =
+        type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
+    __ RecordWriteField(scratch,
+                        JSGlobalPropertyCell::kValueOffset,
+                        value,
+                        scratch2,
+                        kLRHasBeenSaved,
+                        kSaveFPRegs,
+                        OMIT_REMEMBERED_SET,
+                        check_needed);
+  }
 }
 
 
@@ -2285,13 +2308,18 @@
   Register value = ToRegister(instr->value());
   MemOperand target = ContextOperand(context, instr->slot_index());
   __ str(value, target);
-  if (instr->needs_write_barrier()) {
+  if (instr->hydrogen()->NeedsWriteBarrier()) {
+    HType type = instr->hydrogen()->value()->type();
+    SmiCheck check_needed =
+        type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
     __ RecordWriteContextSlot(context,
                               target.offset(),
                               value,
                               scratch0(),
                               kLRHasBeenSaved,
-                              kSaveFPRegs);
+                              kSaveFPRegs,
+                              EMIT_REMEMBERED_SET,
+                              check_needed);
   }
 }
 
@@ -2312,7 +2340,7 @@
                                                Register object,
                                                Handle<Map> type,
                                                Handle<String> name) {
-  LookupResult lookup;
+  LookupResult lookup(isolate());
   type->LookupInDescriptors(NULL, *name, &lookup);
   ASSERT(lookup.IsProperty() &&
          (lookup.type() == FIELD || lookup.type() == CONSTANT_FUNCTION));
@@ -2778,7 +2806,7 @@
 
 void LCodeGen::DoThisFunction(LThisFunction* instr) {
   Register result = ToRegister(instr->result());
-  __ ldr(result, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
+  LoadHeapObject(result, instr->hydrogen()->closure());
 }
 
 
@@ -3297,21 +3325,36 @@
   }
 
   // Do the store.
+  HType type = instr->hydrogen()->value()->type();
+  SmiCheck check_needed =
+      type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
   if (instr->is_in_object()) {
     __ str(value, FieldMemOperand(object, offset));
-    if (instr->needs_write_barrier()) {
+    if (instr->hydrogen()->NeedsWriteBarrier()) {
       // Update the write barrier for the object for in-object properties.
-      __ RecordWriteField(
-          object, offset, value, scratch, kLRHasBeenSaved, kSaveFPRegs);
+      __ RecordWriteField(object,
+                          offset,
+                          value,
+                          scratch,
+                          kLRHasBeenSaved,
+                          kSaveFPRegs,
+                          EMIT_REMEMBERED_SET,
+                          check_needed);
     }
   } else {
     __ ldr(scratch, FieldMemOperand(object, JSObject::kPropertiesOffset));
     __ str(value, FieldMemOperand(scratch, offset));
-    if (instr->needs_write_barrier()) {
+    if (instr->hydrogen()->NeedsWriteBarrier()) {
       // Update the write barrier for the properties array.
       // object is used as a scratch register.
-      __ RecordWriteField(
-          scratch, offset, value, object, kLRHasBeenSaved, kSaveFPRegs);
+      __ RecordWriteField(scratch,
+                          offset,
+                          value,
+                          object,
+                          kLRHasBeenSaved,
+                          kSaveFPRegs,
+                          EMIT_REMEMBERED_SET,
+                          check_needed);
     }
   }
 }
@@ -3362,9 +3405,18 @@
   }
 
   if (instr->hydrogen()->NeedsWriteBarrier()) {
+    HType type = instr->hydrogen()->value()->type();
+    SmiCheck check_needed =
+        type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
     // Compute address of modified element and store it into key register.
     __ add(key, scratch, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
-    __ RecordWrite(elements, key, value, kLRHasBeenSaved, kSaveFPRegs);
+    __ RecordWrite(elements,
+                   key,
+                   value,
+                   kLRHasBeenSaved,
+                   kSaveFPRegs,
+                   EMIT_REMEMBERED_SET,
+                   check_needed);
   }
 }
 
@@ -3487,6 +3539,48 @@
 }
 
 
+void LCodeGen::DoTransitionElementsKind(LTransitionElementsKind* instr) {
+  Register object_reg = ToRegister(instr->object());
+  Register new_map_reg = ToRegister(instr->new_map_reg());
+  Register scratch = scratch0();
+
+  Handle<Map> from_map = instr->original_map();
+  Handle<Map> to_map = instr->transitioned_map();
+  ElementsKind from_kind = from_map->elements_kind();
+  ElementsKind to_kind = to_map->elements_kind();
+
+  Label not_applicable;
+  __ ldr(scratch, FieldMemOperand(object_reg, HeapObject::kMapOffset));
+  __ cmp(scratch, Operand(from_map));
+  __ b(ne, &not_applicable);
+  __ mov(new_map_reg, Operand(to_map));
+  if (from_kind == FAST_SMI_ONLY_ELEMENTS && to_kind == FAST_ELEMENTS) {
+    __ str(new_map_reg, FieldMemOperand(object_reg, HeapObject::kMapOffset));
+    // Write barrier.
+    __ RecordWriteField(object_reg, HeapObject::kMapOffset, new_map_reg,
+                        scratch, kLRHasBeenSaved, kDontSaveFPRegs);
+  } else if (from_kind == FAST_SMI_ONLY_ELEMENTS &&
+      to_kind == FAST_DOUBLE_ELEMENTS) {
+    Register fixed_object_reg = ToRegister(instr->temp_reg());
+    ASSERT(fixed_object_reg.is(r2));
+    ASSERT(new_map_reg.is(r3));
+    __ mov(fixed_object_reg, object_reg);
+    CallCode(isolate()->builtins()->TransitionElementsSmiToDouble(),
+             RelocInfo::CODE_TARGET, instr);
+  } else if (from_kind == FAST_DOUBLE_ELEMENTS && to_kind == FAST_ELEMENTS) {
+    Register fixed_object_reg = ToRegister(instr->temp_reg());
+    ASSERT(fixed_object_reg.is(r2));
+    ASSERT(new_map_reg.is(r3));
+    __ mov(fixed_object_reg, object_reg);
+    CallCode(isolate()->builtins()->TransitionElementsDoubleToObject(),
+             RelocInfo::CODE_TARGET, instr);
+  } else {
+    UNREACHABLE();
+  }
+  __ bind(&not_applicable);
+}
+
+
 void LCodeGen::DoStringAdd(LStringAdd* instr) {
   __ push(ToRegister(instr->left()));
   __ push(ToRegister(instr->right()));
@@ -4203,10 +4297,15 @@
 
 
 void LCodeGen::DoArrayLiteral(LArrayLiteral* instr) {
+  Handle<FixedArray> constant_elements = instr->hydrogen()->constant_elements();
+  ASSERT_EQ(2, constant_elements->length());
+  ElementsKind constant_elements_kind =
+      static_cast<ElementsKind>(Smi::cast(constant_elements->get(0))->value());
+
   __ ldr(r3, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
   __ ldr(r3, FieldMemOperand(r3, JSFunction::kLiteralsOffset));
   __ mov(r2, Operand(Smi::FromInt(instr->hydrogen()->literal_index())));
-  __ mov(r1, Operand(instr->hydrogen()->constant_elements()));
+  __ mov(r1, Operand(constant_elements));
   __ Push(r3, r2, r1);
 
   // Pick the right runtime function or stub to call.
@@ -4223,7 +4322,9 @@
     CallRuntime(Runtime::kCreateArrayLiteralShallow, 3, instr);
   } else {
     FastCloneShallowArrayStub::Mode mode =
-        FastCloneShallowArrayStub::CLONE_ELEMENTS;
+        constant_elements_kind == FAST_DOUBLE_ELEMENTS
+        ? FastCloneShallowArrayStub::CLONE_DOUBLE_ELEMENTS
+        : FastCloneShallowArrayStub::CLONE_ELEMENTS;
     FastCloneShallowArrayStub stub(mode, length);
     CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
   }
@@ -4315,8 +4416,7 @@
   Handle<SharedFunctionInfo> shared_info = instr->shared_info();
   bool pretenure = instr->hydrogen()->pretenure();
   if (!pretenure && shared_info->num_literals() == 0) {
-    FastNewClosureStub stub(
-        shared_info->strict_mode() ? kStrictMode : kNonStrictMode);
+    FastNewClosureStub stub(shared_info->strict_mode_flag());
     __ mov(r1, Operand(shared_info));
     __ push(r1);
     CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
@@ -4349,8 +4449,9 @@
                                                   false_label,
                                                   input,
                                                   instr->type_literal());
-
-  EmitBranch(true_block, false_block, final_branch_condition);
+  if (final_branch_condition != kNoCondition) {
+    EmitBranch(true_block, false_block, final_branch_condition);
+  }
 }
 
 
@@ -4420,9 +4521,7 @@
     final_branch_condition = eq;
 
   } else {
-    final_branch_condition = ne;
     __ b(false_label);
-    // A dead branch instruction will be generated after this point.
   }
 
   return final_branch_condition;
diff --git a/src/arm/lithium-codegen-arm.h b/src/arm/lithium-codegen-arm.h
index 711e459..b01e496 100644
--- a/src/arm/lithium-codegen-arm.h
+++ b/src/arm/lithium-codegen-arm.h
@@ -86,6 +86,7 @@
                                         SwVfpRegister flt_scratch,
                                         DoubleRegister dbl_scratch);
   int ToInteger32(LConstantOperand* op) const;
+  double ToDouble(LConstantOperand* op) const;
   Operand ToOperand(LOperand* op);
   MemOperand ToMemOperand(LOperand* op) const;
   // Returns a MemOperand pointing to the high word of a DoubleStackSlot.
@@ -139,8 +140,8 @@
   bool is_done() const { return status_ == DONE; }
   bool is_aborted() const { return status_ == ABORTED; }
 
-  int strict_mode_flag() const {
-    return info()->is_strict_mode() ? kStrictMode : kNonStrictMode;
+  StrictModeFlag strict_mode_flag() const {
+    return info()->strict_mode_flag();
   }
 
   LChunk* chunk() const { return chunk_; }
@@ -206,7 +207,7 @@
                                LInstruction* instr);
 
   // Generate a direct call to a known function.  Expects the function
-  // to be in edi.
+  // to be in r1.
   void CallKnownFunction(Handle<JSFunction> function,
                          int arity,
                          LInstruction* instr,
@@ -263,7 +264,6 @@
   static Condition TokenToCondition(Token::Value op, bool is_unsigned);
   void EmitGoto(int block);
   void EmitBranch(int left_block, int right_block, Condition cc);
-  void EmitCmpI(LOperand* left, LOperand* right);
   void EmitNumberUntagD(Register input,
                         DoubleRegister result,
                         bool deoptimize_on_undefined,
@@ -272,8 +272,10 @@
   // Emits optimized code for typeof x == "y".  Modifies input register.
   // Returns the condition on which a final split to
   // true and false label should be made, to optimize fallthrough.
-  Condition EmitTypeofIs(Label* true_label, Label* false_label,
-                         Register input, Handle<String> type_name);
+  Condition EmitTypeofIs(Label* true_label,
+                         Label* false_label,
+                         Register input,
+                         Handle<String> type_name);
 
   // Emits optimized code for %_IsObject(x).  Preserves input register.
   // Returns the condition on which a final split to
diff --git a/src/arm/macro-assembler-arm.cc b/src/arm/macro-assembler-arm.cc
index 918f9eb..cf4258c 100644
--- a/src/arm/macro-assembler-arm.cc
+++ b/src/arm/macro-assembler-arm.cc
@@ -1101,24 +1101,16 @@
   // 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.
   mov(r1, Operand(Handle<JSFunction>(function)));
   ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
 
-  // Invoke the cached code.
-  Handle<Code> code(function->code());
   ParameterCount expected(function->shared()->formal_parameter_count());
-  if (V8::UseCrankshaft()) {
-    // TODO(kasperl): For now, we always call indirectly through the
-    // code field in the function to allow recompilation to take effect
-    // without changing any of the call sites.
-    ldr(r3, FieldMemOperand(r1, JSFunction::kCodeEntryOffset));
-    InvokeCode(r3, expected, actual, flag, NullCallWrapper(), call_kind);
-  } else {
-    InvokeCode(code, expected, actual, RelocInfo::CODE_TARGET, flag, call_kind);
-  }
+  // We call indirectly through the code field in the function to
+  // allow recompilation to take effect without changing any of the
+  // call sites.
+  ldr(r3, FieldMemOperand(r1, JSFunction::kCodeEntryOffset));
+  InvokeCode(r3, expected, actual, flag, NullCallWrapper(), call_kind);
 }
 
 
@@ -1602,6 +1594,7 @@
   ASSERT(!result.is(scratch1));
   ASSERT(!result.is(scratch2));
   ASSERT(!scratch1.is(scratch2));
+  ASSERT(!object_size.is(ip));
   ASSERT(!result.is(ip));
   ASSERT(!scratch1.is(ip));
   ASSERT(!scratch2.is(ip));
@@ -2030,7 +2023,8 @@
 void MacroAssembler::TryGetFunctionPrototype(Register function,
                                              Register result,
                                              Register scratch,
-                                             Label* miss) {
+                                             Label* miss,
+                                             bool miss_on_bound_function) {
   // Check that the receiver isn't a smi.
   JumpIfSmi(function, miss);
 
@@ -2038,6 +2032,16 @@
   CompareObjectType(function, result, scratch, JS_FUNCTION_TYPE);
   b(ne, miss);
 
+  if (miss_on_bound_function) {
+    ldr(scratch,
+        FieldMemOperand(function, JSFunction::kSharedFunctionInfoOffset));
+    ldr(scratch,
+        FieldMemOperand(scratch, SharedFunctionInfo::kCompilerHintsOffset));
+    tst(scratch,
+        Operand(Smi::FromInt(1 << SharedFunctionInfo::kBoundFunction)));
+    b(ne, miss);
+  }
+
   // Make sure that the function has an instance prototype.
   Label non_instance;
   ldrb(scratch, FieldMemOperand(result, Map::kBitFieldOffset));
@@ -3147,8 +3151,10 @@
 #ifdef CAN_USE_ARMV5_INSTRUCTIONS
   clz(zeros, source);  // This instruction is only supported after ARM5.
 #else
-  mov(zeros, Operand(0, RelocInfo::NONE));
+  // Order of the next two lines is important: zeros register
+  // can be the same as source register.
   Move(scratch, source);
+  mov(zeros, Operand(0, RelocInfo::NONE));
   // Top 16.
   tst(scratch, Operand(0xffff0000));
   add(zeros, zeros, Operand(16), LeaveCC, eq);
diff --git a/src/arm/macro-assembler-arm.h b/src/arm/macro-assembler-arm.h
index 8ee468a..90c4b37 100644
--- a/src/arm/macro-assembler-arm.h
+++ b/src/arm/macro-assembler-arm.h
@@ -320,8 +320,11 @@
   }
 
   // Push four registers.  Pushes leftmost register first (to highest address).
-  void Push(Register src1, Register src2,
-            Register src3, Register src4, Condition cond = al) {
+  void Push(Register src1,
+            Register src2,
+            Register src3,
+            Register src4,
+            Condition cond = al) {
     ASSERT(!src1.is(src2));
     ASSERT(!src2.is(src3));
     ASSERT(!src1.is(src3));
@@ -360,6 +363,57 @@
     }
   }
 
+  // Pop three registers.  Pops rightmost register first (from lower address).
+  void Pop(Register src1, Register src2, Register src3, Condition cond = al) {
+    ASSERT(!src1.is(src2));
+    ASSERT(!src2.is(src3));
+    ASSERT(!src1.is(src3));
+    if (src1.code() > src2.code()) {
+      if (src2.code() > src3.code()) {
+        ldm(ia_w, sp, src1.bit() | src2.bit() | src3.bit(), cond);
+      } else {
+        ldr(src3, MemOperand(sp, 4, PostIndex), cond);
+        ldm(ia_w, sp, src1.bit() | src2.bit(), cond);
+      }
+    } else {
+      Pop(src2, src3, cond);
+      str(src1, MemOperand(sp, 4, PostIndex), cond);
+    }
+  }
+
+  // Pop four registers.  Pops rightmost register first (from lower address).
+  void Pop(Register src1,
+           Register src2,
+           Register src3,
+           Register src4,
+           Condition cond = al) {
+    ASSERT(!src1.is(src2));
+    ASSERT(!src2.is(src3));
+    ASSERT(!src1.is(src3));
+    ASSERT(!src1.is(src4));
+    ASSERT(!src2.is(src4));
+    ASSERT(!src3.is(src4));
+    if (src1.code() > src2.code()) {
+      if (src2.code() > src3.code()) {
+        if (src3.code() > src4.code()) {
+          ldm(ia_w,
+              sp,
+              src1.bit() | src2.bit() | src3.bit() | src4.bit(),
+              cond);
+        } else {
+          ldr(src4, MemOperand(sp, 4, PostIndex), cond);
+          ldm(ia_w, sp, src1.bit() | src2.bit() | src3.bit(), cond);
+        }
+      } else {
+        Pop(src3, src4, cond);
+        ldm(ia_w, sp, src1.bit() | src2.bit(), cond);
+      }
+    } else {
+      Pop(src2, src3, src4, cond);
+      ldr(src1, MemOperand(sp, 4, PostIndex), cond);
+    }
+  }
+
   // Push and pop the registers that can hold pointers, as defined by the
   // RegList constant kSafepointSavedRegisters.
   void PushSafepointRegisters();
@@ -672,7 +726,8 @@
   void TryGetFunctionPrototype(Register function,
                                Register result,
                                Register scratch,
-                               Label* miss);
+                               Label* miss,
+                               bool miss_on_bound_function = false);
 
   // Compare object type for heap object.  heap_object contains a non-Smi
   // whose object type should be compared with the given type.  This both
diff --git a/src/arm/regexp-macro-assembler-arm.cc b/src/arm/regexp-macro-assembler-arm.cc
index c876467..b212f9f 100644
--- a/src/arm/regexp-macro-assembler-arm.cc
+++ b/src/arm/regexp-macro-assembler-arm.cc
@@ -1111,6 +1111,11 @@
     frame_entry<const String*>(re_frame, kInputString) = *subject;
     frame_entry<const byte*>(re_frame, kInputStart) = new_address;
     frame_entry<const byte*>(re_frame, kInputEnd) = new_address + byte_length;
+  } else if (frame_entry<const String*>(re_frame, kInputString) != *subject) {
+    // Subject string might have been a ConsString that underwent
+    // short-circuiting during GC. That will not change start_address but
+    // will change pointer inside the subject handle.
+    frame_entry<const String*>(re_frame, kInputString) = *subject;
   }
 
   return 0;
diff --git a/src/arm/simulator-arm.cc b/src/arm/simulator-arm.cc
index 5704202..542cc30 100644
--- a/src/arm/simulator-arm.cc
+++ b/src/arm/simulator-arm.cc
@@ -1268,9 +1268,9 @@
 
 // Returns the limit of the stack area to enable checking for stack overflows.
 uintptr_t Simulator::StackLimit() const {
-  // Leave a safety margin of 256 bytes to prevent overrunning the stack when
+  // Leave a safety margin of 512 bytes to prevent overrunning the stack when
   // pushing values.
-  return reinterpret_cast<uintptr_t>(stack_) + 256;
+  return reinterpret_cast<uintptr_t>(stack_) + 512;
 }
 
 
diff --git a/src/arm/stub-cache-arm.cc b/src/arm/stub-cache-arm.cc
index 4558afe..f9a10c4 100644
--- a/src/arm/stub-cache-arm.cc
+++ b/src/arm/stub-cache-arm.cc
@@ -95,7 +95,63 @@
 // must always call a backup property check that is complete.
 // This function is safe to call if the receiver has fast properties.
 // Name must be a symbol and receiver must be a heap object.
-MUST_USE_RESULT static MaybeObject* GenerateDictionaryNegativeLookup(
+static void GenerateDictionaryNegativeLookup(MacroAssembler* masm,
+                                             Label* miss_label,
+                                             Register receiver,
+                                             Handle<String> name,
+                                             Register scratch0,
+                                             Register scratch1) {
+  ASSERT(name->IsSymbol());
+  Counters* counters = masm->isolate()->counters();
+  __ IncrementCounter(counters->negative_lookups(), 1, scratch0, scratch1);
+  __ IncrementCounter(counters->negative_lookups_miss(), 1, scratch0, scratch1);
+
+  Label done;
+
+  const int kInterceptorOrAccessCheckNeededMask =
+      (1 << Map::kHasNamedInterceptor) | (1 << Map::kIsAccessCheckNeeded);
+
+  // Bail out if the receiver has a named interceptor or requires access checks.
+  Register map = scratch1;
+  __ ldr(map, FieldMemOperand(receiver, HeapObject::kMapOffset));
+  __ ldrb(scratch0, FieldMemOperand(map, Map::kBitFieldOffset));
+  __ tst(scratch0, Operand(kInterceptorOrAccessCheckNeededMask));
+  __ b(ne, miss_label);
+
+  // Check that receiver is a JSObject.
+  __ ldrb(scratch0, FieldMemOperand(map, Map::kInstanceTypeOffset));
+  __ cmp(scratch0, Operand(FIRST_SPEC_OBJECT_TYPE));
+  __ b(lt, miss_label);
+
+  // Load properties array.
+  Register properties = scratch0;
+  __ ldr(properties, FieldMemOperand(receiver, JSObject::kPropertiesOffset));
+  // Check that the properties array is a dictionary.
+  __ ldr(map, FieldMemOperand(properties, HeapObject::kMapOffset));
+  Register tmp = properties;
+  __ LoadRoot(tmp, Heap::kHashTableMapRootIndex);
+  __ cmp(map, tmp);
+  __ b(ne, miss_label);
+
+  // Restore the temporarily used register.
+  __ ldr(properties, FieldMemOperand(receiver, JSObject::kPropertiesOffset));
+
+
+  StringDictionaryLookupStub::GenerateNegativeLookup(masm,
+                                                     miss_label,
+                                                     &done,
+                                                     receiver,
+                                                     properties,
+                                                     name,
+                                                     scratch1);
+  __ bind(&done);
+  __ DecrementCounter(counters->negative_lookups_miss(), 1, scratch0, scratch1);
+}
+
+
+// TODO(kmillikin): Eliminate this function when the stub cache is fully
+// handlified.
+MUST_USE_RESULT static MaybeObject* TryGenerateDictionaryNegativeLookup(
     MacroAssembler* masm,
     Label* miss_label,
     Register receiver,
@@ -138,7 +194,7 @@
   __ ldr(properties, FieldMemOperand(receiver, JSObject::kPropertiesOffset));
 
 
-  MaybeObject* result = StringDictionaryLookupStub::GenerateNegativeLookup(
+  MaybeObject* result = StringDictionaryLookupStub::TryGenerateNegativeLookup(
       masm,
       miss_label,
       &done,
@@ -259,8 +315,10 @@
 // are loaded directly otherwise the property is loaded from the properties
 // fixed array.
 void StubCompiler::GenerateFastPropertyLoad(MacroAssembler* masm,
-                                            Register dst, Register src,
-                                            JSObject* holder, int index) {
+                                            Register dst,
+                                            Register src,
+                                            Handle<JSObject> holder,
+                                            int index) {
   // Adjust for the number of properties stored in the holder.
   index -= holder->map()->inobject_properties();
   if (index < 0) {
@@ -367,9 +425,9 @@
 // may be clobbered.  Upon branch to miss_label, the receiver and name
 // registers have their original values.
 void StubCompiler::GenerateStoreField(MacroAssembler* masm,
-                                      JSObject* object,
+                                      Handle<JSObject> object,
                                       int index,
-                                      Map* transition,
+                                      Handle<Map> transition,
                                       Register receiver_reg,
                                       Register name_reg,
                                       Register scratch,
@@ -395,11 +453,11 @@
   ASSERT(object->IsJSGlobalProxy() || !object->IsAccessCheckNeeded());
 
   // Perform map transition for the receiver if necessary.
-  if ((transition != NULL) && (object->map()->unused_property_fields() == 0)) {
+  if (!transition.is_null() && (object->map()->unused_property_fields() == 0)) {
     // The properties must be extended before we can store the value.
     // We jump to a runtime call that extends the properties array.
     __ push(receiver_reg);
-    __ mov(r2, Operand(Handle<Map>(transition)));
+    __ mov(r2, Operand(transition));
     __ Push(r2, r0);
     __ TailCallExternalReference(
         ExternalReference(IC_Utility(IC::kSharedStoreIC_ExtendStorage),
@@ -409,10 +467,10 @@
     return;
   }
 
-  if (transition != NULL) {
+  if (!transition.is_null()) {
     // Update the map of the object; no write barrier updating is
     // needed because the map is never in new space.
-    __ mov(ip, Operand(Handle<Map>(transition)));
+    __ mov(ip, Operand(transition));
     __ str(ip, FieldMemOperand(receiver_reg, HeapObject::kMapOffset));
   }
 
@@ -467,20 +525,15 @@
 
 void StubCompiler::GenerateLoadMiss(MacroAssembler* masm, Code::Kind kind) {
   ASSERT(kind == Code::LOAD_IC || kind == Code::KEYED_LOAD_IC);
-  Code* code = NULL;
-  if (kind == Code::LOAD_IC) {
-    code = masm->isolate()->builtins()->builtin(Builtins::kLoadIC_Miss);
-  } else {
-    code = masm->isolate()->builtins()->builtin(Builtins::kKeyedLoadIC_Miss);
-  }
-
-  Handle<Code> ic(code);
-  __ Jump(ic, RelocInfo::CODE_TARGET);
+  Handle<Code> code = (kind == Code::LOAD_IC)
+      ? masm->isolate()->builtins()->LoadIC_Miss()
+      : masm->isolate()->builtins()->KeyedLoadIC_Miss();
+  __ Jump(code, RelocInfo::CODE_TARGET);
 }
 
 
 static void GenerateCallFunction(MacroAssembler* masm,
-                                 Object* object,
+                                 Handle<Object> object,
                                  const ParameterCount& arguments,
                                  Label* miss,
                                  Code::ExtraICState extra_ic_state) {
@@ -868,7 +921,26 @@
 // Generate code to check that a global property cell is empty. Create
 // the property cell at compilation time if no cell exists for the
 // property.
-MUST_USE_RESULT static MaybeObject* GenerateCheckPropertyCell(
+static void GenerateCheckPropertyCell(MacroAssembler* masm,
+                                      Handle<GlobalObject> global,
+                                      Handle<String> name,
+                                      Register scratch,
+                                      Label* miss) {
+  Handle<JSGlobalPropertyCell> cell =
+      GlobalObject::EnsurePropertyCell(global, name);
+  ASSERT(cell->value()->IsTheHole());
+  __ mov(scratch, Operand(cell));
+  __ ldr(scratch,
+         FieldMemOperand(scratch, JSGlobalPropertyCell::kValueOffset));
+  __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
+  __ cmp(scratch, ip);
+  __ b(ne, miss);
+}
+
+
+// TODO(kmillikin): Eliminate this function when the stub cache is fully
+// handlified.
+MUST_USE_RESULT static MaybeObject* TryGenerateCheckPropertyCell(
     MacroAssembler* masm,
     GlobalObject* global,
     String* name,
@@ -889,9 +961,32 @@
   return cell;
 }
 
+
 // Calls GenerateCheckPropertyCell for each global object in the prototype chain
 // from object to (but not including) holder.
-MUST_USE_RESULT static MaybeObject* GenerateCheckPropertyCells(
+static void GenerateCheckPropertyCells(MacroAssembler* masm,
+                                       Handle<JSObject> object,
+                                       Handle<JSObject> holder,
+                                       Handle<String> name,
+                                       Register scratch,
+                                       Label* miss) {
+  Handle<JSObject> current = object;
+  while (!current.is_identical_to(holder)) {
+    if (current->IsGlobalObject()) {
+      GenerateCheckPropertyCell(masm,
+                                Handle<GlobalObject>::cast(current),
+                                name,
+                                scratch,
+                                miss);
+    }
+    current = Handle<JSObject>(JSObject::cast(current->GetPrototype()));
+  }
+}
+
+
+// TODO(kmillikin): Eliminate this function when the stub cache is fully
+// handlified.
+MUST_USE_RESULT static MaybeObject* TryGenerateCheckPropertyCells(
     MacroAssembler* masm,
     JSObject* object,
     JSObject* holder,
@@ -902,7 +997,7 @@
   while (current != holder) {
     if (current->IsGlobalObject()) {
       // Returns a cell or a failure.
-      MaybeObject* result = GenerateCheckPropertyCell(
+      MaybeObject* result = TryGenerateCheckPropertyCell(
           masm,
           GlobalObject::cast(current),
           name,
@@ -1027,6 +1122,112 @@
 #define __ ACCESS_MASM(masm())
 
 
+Register StubCompiler::CheckPrototypes(Handle<JSObject> object,
+                                       Register object_reg,
+                                       Handle<JSObject> holder,
+                                       Register holder_reg,
+                                       Register scratch1,
+                                       Register scratch2,
+                                       Handle<String> name,
+                                       int save_at_depth,
+                                       Label* miss) {
+  // Make sure there's no overlap between holder and object registers.
+  ASSERT(!scratch1.is(object_reg) && !scratch1.is(holder_reg));
+  ASSERT(!scratch2.is(object_reg) && !scratch2.is(holder_reg)
+         && !scratch2.is(scratch1));
+
+  // Keep track of the current object in register reg.
+  Register reg = object_reg;
+  int depth = 0;
+
+  if (save_at_depth == depth) {
+    __ str(reg, MemOperand(sp));
+  }
+
+  // Check the maps in the prototype chain.
+  // Traverse the prototype chain from the object and do map checks.
+  Handle<JSObject> current = object;
+  while (!current.is_identical_to(holder)) {
+    ++depth;
+
+    // Only global objects and objects that do not require access
+    // checks are allowed in stubs.
+    ASSERT(current->IsJSGlobalProxy() || !current->IsAccessCheckNeeded());
+
+    Handle<JSObject> prototype(JSObject::cast(current->GetPrototype()));
+    if (!current->HasFastProperties() &&
+        !current->IsJSGlobalObject() &&
+        !current->IsJSGlobalProxy()) {
+      if (!name->IsSymbol()) {
+        name = factory()->LookupSymbol(name);
+      }
+      ASSERT(current->property_dictionary()->FindEntry(*name) ==
+             StringDictionary::kNotFound);
+
+      GenerateDictionaryNegativeLookup(masm(), miss, reg, name,
+                                       scratch1, scratch2);
+
+      __ ldr(scratch1, FieldMemOperand(reg, HeapObject::kMapOffset));
+      reg = holder_reg;  // From now on the object will be in holder_reg.
+      __ ldr(reg, FieldMemOperand(scratch1, Map::kPrototypeOffset));
+    } else {
+      Handle<Map> current_map(current->map());
+      __ ldr(scratch1, FieldMemOperand(reg, HeapObject::kMapOffset));
+      __ cmp(scratch1, Operand(current_map));
+      // Branch on the result of the map check.
+      __ b(ne, miss);
+      // Check access rights to the global object.  This has to happen after
+      // the map check so that we know that the object is actually a global
+      // object.
+      if (current->IsJSGlobalProxy()) {
+        __ CheckAccessGlobalProxy(reg, scratch2, miss);
+      }
+      reg = holder_reg;  // From now on the object will be in holder_reg.
+
+      if (heap()->InNewSpace(*prototype)) {
+        // The prototype is in new space; we cannot store a reference to it
+        // in the code.  Load it from the map.
+        __ ldr(reg, FieldMemOperand(scratch1, Map::kPrototypeOffset));
+      } else {
+        // The prototype is in old space; load it directly.
+        __ mov(reg, Operand(prototype));
+      }
+    }
+
+    if (save_at_depth == depth) {
+      __ str(reg, MemOperand(sp));
+    }
+
+    // Go to the next object in the prototype chain.
+    current = prototype;
+  }
+
+  // Log the check depth.
+  LOG(masm()->isolate(), IntEvent("check-maps-depth", depth + 1));
+
+  // Check the holder map.
+  __ ldr(scratch1, FieldMemOperand(reg, HeapObject::kMapOffset));
+  __ cmp(scratch1, Operand(Handle<Map>(current->map())));
+  __ b(ne, miss);
+
+  // Perform security check for access to the global object.
+  ASSERT(holder->IsJSGlobalProxy() || !holder->IsAccessCheckNeeded());
+  if (holder->IsJSGlobalProxy()) {
+    __ CheckAccessGlobalProxy(reg, scratch1, miss);
+  }
+
+  // If we've skipped any global objects, it's not enough to verify that
+  // their maps haven't changed.  We also need to check that the property
+  // cell for the property is still empty.
+  GenerateCheckPropertyCells(masm(), object, holder, name, scratch1, miss);
+
+  // Return the register containing the holder.
+  return reg;
+}
+
+
+// TODO(kmillikin): Eliminate this function when the stub cache is fully
+// handlified.
 Register StubCompiler::CheckPrototypes(JSObject* object,
                                        Register object_reg,
                                        JSObject* holder,
@@ -1076,12 +1277,13 @@
       ASSERT(current->property_dictionary()->FindEntry(name) ==
              StringDictionary::kNotFound);
 
-      MaybeObject* negative_lookup = GenerateDictionaryNegativeLookup(masm(),
-                                                                      miss,
-                                                                      reg,
-                                                                      name,
-                                                                      scratch1,
-                                                                      scratch2);
+      MaybeObject* negative_lookup =
+          TryGenerateDictionaryNegativeLookup(masm(),
+                                              miss,
+                                              reg,
+                                              name,
+                                              scratch1,
+                                              scratch2);
       if (negative_lookup->IsFailure()) {
         set_failure(Failure::cast(negative_lookup));
         return reg;
@@ -1150,17 +1352,17 @@
   ASSERT(holder->IsJSGlobalProxy() || !holder->IsAccessCheckNeeded());
   if (holder->IsJSGlobalProxy()) {
     __ CheckAccessGlobalProxy(reg, scratch1, miss);
-  };
+  }
 
   // If we've skipped any global objects, it's not enough to verify
   // that their maps haven't changed.  We also need to check that the
   // property cell for the property is still empty.
-  MaybeObject* result = GenerateCheckPropertyCells(masm(),
-                                                   object,
-                                                   holder,
-                                                   name,
-                                                   scratch1,
-                                                   miss);
+  MaybeObject* result = TryGenerateCheckPropertyCells(masm(),
+                                                      object,
+                                                      holder,
+                                                      name,
+                                                      scratch1,
+                                                      miss);
   if (result->IsFailure()) set_failure(Failure::cast(result));
 
   // Return the register containing the holder.
@@ -1168,45 +1370,44 @@
 }
 
 
-void StubCompiler::GenerateLoadField(JSObject* object,
-                                     JSObject* holder,
+void StubCompiler::GenerateLoadField(Handle<JSObject> object,
+                                     Handle<JSObject> holder,
                                      Register receiver,
                                      Register scratch1,
                                      Register scratch2,
                                      Register scratch3,
                                      int index,
-                                     String* name,
+                                     Handle<String> name,
                                      Label* miss) {
   // Check that the receiver isn't a smi.
   __ JumpIfSmi(receiver, miss);
 
   // Check that the maps haven't changed.
-  Register reg =
-      CheckPrototypes(object, receiver, holder, scratch1, scratch2, scratch3,
-                      name, miss);
+  Register reg = CheckPrototypes(
+      object, receiver, holder, scratch1, scratch2, scratch3, name, miss);
   GenerateFastPropertyLoad(masm(), r0, reg, holder, index);
   __ Ret();
 }
 
 
-void StubCompiler::GenerateLoadConstant(JSObject* object,
-                                        JSObject* holder,
+void StubCompiler::GenerateLoadConstant(Handle<JSObject> object,
+                                        Handle<JSObject> holder,
                                         Register receiver,
                                         Register scratch1,
                                         Register scratch2,
                                         Register scratch3,
-                                        Object* value,
-                                        String* name,
+                                        Handle<Object> value,
+                                        Handle<String> name,
                                         Label* miss) {
   // Check that the receiver isn't a smi.
   __ JumpIfSmi(receiver, miss);
 
   // Check that the maps haven't changed.
-  CheckPrototypes(object, receiver, holder, scratch1, scratch2, scratch3, name,
-                  miss);
+  CheckPrototypes(
+      object, receiver, holder, scratch1, scratch2, scratch3, name, miss);
 
   // Return the constant value.
-  __ mov(r0, Operand(Handle<Object>(value)));
+  __ mov(r0, Operand(value));
   __ Ret();
 }
 
@@ -1365,7 +1566,8 @@
       // We found FIELD property in prototype chain of interceptor's holder.
       // Retrieve a field from field's holder.
       GenerateFastPropertyLoad(masm(), r0, holder_reg,
-                               lookup->holder(), lookup->GetFieldIndex());
+                               Handle<JSObject>(lookup->holder()),
+                               lookup->GetFieldIndex());
       __ Ret();
     } else {
       // We found CALLBACKS property in prototype chain of interceptor's
@@ -1416,9 +1618,9 @@
 }
 
 
-void CallStubCompiler::GenerateNameCheck(String* name, Label* miss) {
+void CallStubCompiler::GenerateNameCheck(Handle<String> name, Label* miss) {
   if (kind_ == Code::KEYED_CALL_IC) {
-    __ cmp(r2, Operand(Handle<String>(name)));
+    __ cmp(r2, Operand(name));
     __ b(ne, miss);
   }
 }
@@ -1478,11 +1680,22 @@
 }
 
 
-MaybeObject* CallStubCompiler::GenerateMissBranch() {
-  MaybeObject* maybe_obj =
+void CallStubCompiler::GenerateMissBranch() {
+  Handle<Code> code =
       isolate()->stub_cache()->ComputeCallMiss(arguments().immediate(),
                                                kind_,
-                                               extra_ic_state_);
+                                               extra_state_);
+  __ Jump(code, RelocInfo::CODE_TARGET);
+}
+
+
+// TODO(kmillikin): Eliminate this function when the stub cache is fully
+// handlified.
+MaybeObject* CallStubCompiler::TryGenerateMissBranch() {
+  MaybeObject* maybe_obj =
+      isolate()->stub_cache()->TryComputeCallMiss(arguments().immediate(),
+                                                  kind_,
+                                                  extra_state_);
   Object* obj;
   if (!maybe_obj->ToObject(&obj)) return maybe_obj;
   __ Jump(Handle<Code>(Code::cast(obj)), RelocInfo::CODE_TARGET);
@@ -1490,10 +1703,10 @@
 }
 
 
-MaybeObject* CallStubCompiler::CompileCallField(JSObject* object,
-                                                JSObject* holder,
+Handle<Code> CallStubCompiler::CompileCallField(Handle<JSObject> object,
+                                                Handle<JSObject> holder,
                                                 int index,
-                                                String* name) {
+                                                Handle<String> name) {
   // ----------- S t a t e -------------
   //  -- r2    : name
   //  -- lr    : return address
@@ -1513,12 +1726,11 @@
   Register reg = CheckPrototypes(object, r0, holder, r1, r3, r4, name, &miss);
   GenerateFastPropertyLoad(masm(), r1, reg, holder, index);
 
-  GenerateCallFunction(masm(), object, arguments(), &miss, extra_ic_state_);
+  GenerateCallFunction(masm(), object, arguments(), &miss, extra_state_);
 
   // Handle call cache miss.
   __ bind(&miss);
-  MaybeObject* maybe_result = GenerateMissBranch();
-  if (maybe_result->IsFailure()) return maybe_result;
+  GenerateMissBranch();
 
   // Return the generated code.
   return GetCode(FIELD, name);
@@ -1543,7 +1755,7 @@
 
   Label miss;
 
-  GenerateNameCheck(name, &miss);
+  GenerateNameCheck(Handle<String>(name), &miss);
 
   Register receiver = r1;
 
@@ -1619,7 +1831,7 @@
       __ bind(&with_write_barrier);
 
       __ ldr(r6, FieldMemOperand(receiver, HeapObject::kMapOffset));
-      __ CheckFastSmiOnlyElements(r6, r6, &call_builtin);
+      __ CheckFastObjectElements(r6, r6, &call_builtin);
 
       // Save new length.
       __ str(r0, FieldMemOperand(receiver, JSArray::kLengthOffset));
@@ -1709,11 +1921,11 @@
 
   // Handle call cache miss.
   __ bind(&miss);
-  MaybeObject* maybe_result = GenerateMissBranch();
+  MaybeObject* maybe_result = TryGenerateMissBranch();
   if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
-  return GetCode(function);
+  return TryGetCode(function);
 }
 
 
@@ -1738,7 +1950,7 @@
   Register receiver = r1;
   Register elements = r3;
 
-  GenerateNameCheck(name, &miss);
+  GenerateNameCheck(Handle<String>(name), &miss);
 
   // Get the receiver from the stack
   const int argc = arguments().immediate();
@@ -1798,11 +2010,11 @@
 
   // Handle call cache miss.
   __ bind(&miss);
-  MaybeObject* maybe_result = GenerateMissBranch();
+  MaybeObject* maybe_result = TryGenerateMissBranch();
   if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
-  return GetCode(function);
+  return TryGetCode(function);
 }
 
 
@@ -1831,12 +2043,12 @@
   Label* index_out_of_range_label = &index_out_of_range;
 
   if (kind_ == Code::CALL_IC &&
-      (CallICBase::StringStubState::decode(extra_ic_state_) ==
+      (CallICBase::StringStubState::decode(extra_state_) ==
        DEFAULT_STRING_STUB)) {
     index_out_of_range_label = &miss;
   }
 
-  GenerateNameCheck(name, &name_miss);
+  GenerateNameCheck(Handle<String>(name), &name_miss);
 
   // Check that the maps starting from the prototype haven't changed.
   GenerateDirectLoadGlobalFunctionPrototype(masm(),
@@ -1884,11 +2096,11 @@
   // Restore function name in r2.
   __ Move(r2, Handle<String>(name));
   __ bind(&name_miss);
-  MaybeObject* maybe_result = GenerateMissBranch();
+  MaybeObject* maybe_result = TryGenerateMissBranch();
   if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
-  return GetCode(function);
+  return TryGetCode(function);
 }
 
 
@@ -1917,12 +2129,12 @@
   Label* index_out_of_range_label = &index_out_of_range;
 
   if (kind_ == Code::CALL_IC &&
-      (CallICBase::StringStubState::decode(extra_ic_state_) ==
+      (CallICBase::StringStubState::decode(extra_state_) ==
        DEFAULT_STRING_STUB)) {
     index_out_of_range_label = &miss;
   }
 
-  GenerateNameCheck(name, &name_miss);
+  GenerateNameCheck(Handle<String>(name), &name_miss);
 
   // Check that the maps starting from the prototype haven't changed.
   GenerateDirectLoadGlobalFunctionPrototype(masm(),
@@ -1972,11 +2184,11 @@
   // Restore function name in r2.
   __ Move(r2, Handle<String>(name));
   __ bind(&name_miss);
-  MaybeObject* maybe_result = GenerateMissBranch();
+  MaybeObject* maybe_result = TryGenerateMissBranch();
   if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
-  return GetCode(function);
+  return TryGetCode(function);
 }
 
 
@@ -2001,7 +2213,7 @@
   if (!object->IsJSObject() || argc != 1) return heap()->undefined_value();
 
   Label miss;
-  GenerateNameCheck(name, &miss);
+  GenerateNameCheck(Handle<String>(name), &miss);
 
   if (cell == NULL) {
     __ ldr(r1, MemOperand(sp, 1 * kPointerSize));
@@ -2044,11 +2256,11 @@
 
   __ bind(&miss);
   // r2: function name.
-  MaybeObject* maybe_result = GenerateMissBranch();
+  MaybeObject* maybe_result = TryGenerateMissBranch();
   if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
-  return (cell == NULL) ? GetCode(function) : GetCode(NORMAL, name);
+  return (cell == NULL) ? TryGetCode(function) : TryGetCode(NORMAL, name);
 }
 
 
@@ -2078,7 +2290,7 @@
   if (!object->IsJSObject() || argc != 1) return heap()->undefined_value();
 
   Label miss, slow;
-  GenerateNameCheck(name, &miss);
+  GenerateNameCheck(Handle<String>(name), &miss);
 
   if (cell == NULL) {
     __ ldr(r1, MemOperand(sp, 1 * kPointerSize));
@@ -2192,11 +2404,11 @@
 
   __ bind(&miss);
   // r2: function name.
-  MaybeObject* maybe_result = GenerateMissBranch();
+  MaybeObject* maybe_result = TryGenerateMissBranch();
   if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
-  return (cell == NULL) ? GetCode(function) : GetCode(NORMAL, name);
+  return (cell == NULL) ? TryGetCode(function) : TryGetCode(NORMAL, name);
 }
 
 
@@ -2220,7 +2432,7 @@
   if (!object->IsJSObject() || argc != 1) return heap()->undefined_value();
 
   Label miss;
-  GenerateNameCheck(name, &miss);
+  GenerateNameCheck(Handle<String>(name), &miss);
 
   if (cell == NULL) {
     __ ldr(r1, MemOperand(sp, 1 * kPointerSize));
@@ -2293,11 +2505,11 @@
 
   __ bind(&miss);
   // r2: function name.
-  MaybeObject* maybe_result = GenerateMissBranch();
+  MaybeObject* maybe_result = TryGenerateMissBranch();
   if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
-  return (cell == NULL) ? GetCode(function) : GetCode(NORMAL, name);
+  return (cell == NULL) ? TryGetCode(function) : TryGetCode(NORMAL, name);
 }
 
 
@@ -2322,7 +2534,7 @@
 
   Label miss, miss_before_stack_reserved;
 
-  GenerateNameCheck(name, &miss_before_stack_reserved);
+  GenerateNameCheck(Handle<String>(name), &miss_before_stack_reserved);
 
   // Get the receiver from the stack.
   const int argc = arguments().immediate();
@@ -2347,11 +2559,11 @@
   FreeSpaceForFastApiCall(masm());
 
   __ bind(&miss_before_stack_reserved);
-  MaybeObject* maybe_result = GenerateMissBranch();
+  MaybeObject* maybe_result = TryGenerateMissBranch();
   if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
-  return GetCode(function);
+  return TryGetCode(function);
 }
 
 
@@ -2375,7 +2587,7 @@
 
   Label miss;
 
-  GenerateNameCheck(name, &miss);
+  GenerateNameCheck(Handle<String>(name), &miss);
 
   // Get the receiver from the stack
   const int argc = arguments().immediate();
@@ -2474,18 +2686,18 @@
       UNREACHABLE();
   }
 
-  CallKind call_kind = CallICBase::Contextual::decode(extra_ic_state_)
+  CallKind call_kind = CallICBase::Contextual::decode(extra_state_)
       ? CALL_AS_FUNCTION
       : CALL_AS_METHOD;
   __ InvokeFunction(function, arguments(), JUMP_FUNCTION, call_kind);
 
   // Handle call cache miss.
   __ bind(&miss);
-  MaybeObject* maybe_result = GenerateMissBranch();
+  MaybeObject* maybe_result = TryGenerateMissBranch();
   if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
-  return GetCode(function);
+  return TryGetCode(function);
 }
 
 
@@ -2499,18 +2711,18 @@
 
   Label miss;
 
-  GenerateNameCheck(name, &miss);
+  GenerateNameCheck(Handle<String>(name), &miss);
 
   // Get the number of arguments.
   const int argc = arguments().immediate();
 
-  LookupResult lookup;
+  LookupResult lookup(isolate());
   LookupPostInterceptor(holder, name, &lookup);
 
   // Get the receiver from the stack.
   __ ldr(r1, MemOperand(sp, argc * kPointerSize));
 
-  CallInterceptorCompiler compiler(this, arguments(), r2, extra_ic_state_);
+  CallInterceptorCompiler compiler(this, arguments(), r2, extra_state_);
   MaybeObject* result = compiler.Compile(masm(),
                                          object,
                                          holder,
@@ -2530,15 +2742,16 @@
   // Restore receiver.
   __ ldr(r0, MemOperand(sp, argc * kPointerSize));
 
-  GenerateCallFunction(masm(), object, arguments(), &miss, extra_ic_state_);
+  GenerateCallFunction(masm(), Handle<Object>(object), arguments(), &miss,
+                       extra_state_);
 
   // Handle call cache miss.
   __ bind(&miss);
-  MaybeObject* maybe_result = GenerateMissBranch();
+  MaybeObject* maybe_result = TryGenerateMissBranch();
   if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
-  return GetCode(INTERCEPTOR, name);
+  return TryGetCode(INTERCEPTOR, name);
 }
 
 
@@ -2563,7 +2776,7 @@
 
   Label miss;
 
-  GenerateNameCheck(name, &miss);
+  GenerateNameCheck(Handle<String>(name), &miss);
 
   // Get the number of arguments.
   const int argc = arguments().immediate();
@@ -2585,39 +2798,33 @@
   // Jump to the cached code (tail call).
   Counters* counters = masm()->isolate()->counters();
   __ IncrementCounter(counters->call_global_inline(), 1, r3, r4);
-  ASSERT(function->is_compiled());
   Handle<Code> code(function->code());
   ParameterCount expected(function->shared()->formal_parameter_count());
-  CallKind call_kind = CallICBase::Contextual::decode(extra_ic_state_)
+  CallKind call_kind = CallICBase::Contextual::decode(extra_state_)
       ? CALL_AS_FUNCTION
       : CALL_AS_METHOD;
-  if (V8::UseCrankshaft()) {
-    // TODO(kasperl): For now, we always call indirectly through the
-    // code field in the function to allow recompilation to take effect
-    // without changing any of the call sites.
-    __ ldr(r3, FieldMemOperand(r1, JSFunction::kCodeEntryOffset));
-    __ InvokeCode(r3, expected, arguments(), JUMP_FUNCTION,
-                  NullCallWrapper(), call_kind);
-  } else {
-    __ InvokeCode(code, expected, arguments(), RelocInfo::CODE_TARGET,
-                  JUMP_FUNCTION, call_kind);
-  }
+  // We call indirectly through the code field in the function to
+  // allow recompilation to take effect without changing any of the
+  // call sites.
+  __ ldr(r3, FieldMemOperand(r1, JSFunction::kCodeEntryOffset));
+  __ InvokeCode(r3, expected, arguments(), JUMP_FUNCTION,
+                NullCallWrapper(), call_kind);
 
   // Handle call cache miss.
   __ bind(&miss);
   __ IncrementCounter(counters->call_global_inline_miss(), 1, r1, r3);
-  MaybeObject* maybe_result = GenerateMissBranch();
+  MaybeObject* maybe_result = TryGenerateMissBranch();
   if (maybe_result->IsFailure()) return maybe_result;
 
   // Return the generated code.
-  return GetCode(NORMAL, name);
+  return TryGetCode(NORMAL, name);
 }
 
 
-MaybeObject* StoreStubCompiler::CompileStoreField(JSObject* object,
+Handle<Code> StoreStubCompiler::CompileStoreField(Handle<JSObject> object,
                                                   int index,
-                                                  Map* transition,
-                                                  String* name) {
+                                                  Handle<Map> transition,
+                                                  Handle<String> name) {
   // ----------- S t a t e -------------
   //  -- r0    : value
   //  -- r1    : receiver
@@ -2626,24 +2833,20 @@
   // -----------------------------------
   Label miss;
 
-  GenerateStoreField(masm(),
-                     object,
-                     index,
-                     transition,
-                     r1, r2, r3,
-                     &miss);
+  GenerateStoreField(masm(), object, index, transition, r1, r2, r3, &miss);
   __ bind(&miss);
   Handle<Code> ic = masm()->isolate()->builtins()->StoreIC_Miss();
   __ Jump(ic, RelocInfo::CODE_TARGET);
 
   // Return the generated code.
-  return GetCode(transition == NULL ? FIELD : MAP_TRANSITION, name);
+  return GetCode(transition.is_null() ? FIELD : MAP_TRANSITION, name);
 }
 
 
-MaybeObject* StoreStubCompiler::CompileStoreCallback(JSObject* object,
-                                                     AccessorInfo* callback,
-                                                     String* name) {
+Handle<Code> StoreStubCompiler::CompileStoreCallback(
+    Handle<JSObject> object,
+    Handle<AccessorInfo> callback,
+    Handle<String> name) {
   // ----------- S t a t e -------------
   //  -- r0    : value
   //  -- r1    : receiver
@@ -2670,7 +2873,7 @@
   ASSERT(object->IsJSGlobalProxy() || !object->IsAccessCheckNeeded());
 
   __ push(r1);  // receiver
-  __ mov(ip, Operand(Handle<AccessorInfo>(callback)));  // callback info
+  __ mov(ip, Operand(callback));  // callback info
   __ Push(ip, r2, r0);
 
   // Do tail-call to the runtime system.
@@ -2689,8 +2892,9 @@
 }
 
 
-MaybeObject* StoreStubCompiler::CompileStoreInterceptor(JSObject* receiver,
-                                                        String* name) {
+Handle<Code> StoreStubCompiler::CompileStoreInterceptor(
+    Handle<JSObject> receiver,
+    Handle<String> name) {
   // ----------- S t a t e -------------
   //  -- r0    : value
   //  -- r1    : receiver
@@ -2737,9 +2941,10 @@
 }
 
 
-MaybeObject* StoreStubCompiler::CompileStoreGlobal(GlobalObject* object,
-                                                   JSGlobalPropertyCell* cell,
-                                                   String* name) {
+Handle<Code> StoreStubCompiler::CompileStoreGlobal(
+    Handle<GlobalObject> object,
+    Handle<JSGlobalPropertyCell> cell,
+    Handle<String> name) {
   // ----------- S t a t e -------------
   //  -- r0    : value
   //  -- r1    : receiver
@@ -2757,7 +2962,7 @@
   // cell could have been deleted and reintroducing the global needs
   // to update the property details in the property dictionary of the
   // global object. We bail out to the runtime system to do that.
-  __ mov(r4, Operand(Handle<JSGlobalPropertyCell>(cell)));
+  __ mov(r4, Operand(cell));
   __ LoadRoot(r5, Heap::kTheHoleValueRootIndex);
   __ ldr(r6, FieldMemOperand(r4, JSGlobalPropertyCell::kValueOffset));
   __ cmp(r5, r6);
@@ -2790,9 +2995,9 @@
 }
 
 
-MaybeObject* LoadStubCompiler::CompileLoadNonexistent(String* name,
-                                                      JSObject* object,
-                                                      JSObject* last) {
+Handle<Code> LoadStubCompiler::CompileLoadNonexistent(Handle<String> name,
+                                                      Handle<JSObject> object,
+                                                      Handle<JSObject> last) {
   // ----------- S t a t e -------------
   //  -- r0    : receiver
   //  -- lr    : return address
@@ -2808,15 +3013,8 @@
   // If the last object in the prototype chain is a global object,
   // check that the global property cell is empty.
   if (last->IsGlobalObject()) {
-    MaybeObject* cell = GenerateCheckPropertyCell(masm(),
-                                                  GlobalObject::cast(last),
-                                                  name,
-                                                  r1,
-                                                  &miss);
-    if (cell->IsFailure()) {
-      miss.Unuse();
-      return cell;
-    }
+    GenerateCheckPropertyCell(
+        masm(), Handle<GlobalObject>::cast(last), name, r1, &miss);
   }
 
   // Return undefined if maps of the full prototype chain are still the
@@ -2828,14 +3026,14 @@
   GenerateLoadMiss(masm(), Code::LOAD_IC);
 
   // Return the generated code.
-  return GetCode(NONEXISTENT, heap()->empty_string());
+  return GetCode(NONEXISTENT, factory()->empty_string());
 }
 
 
-MaybeObject* LoadStubCompiler::CompileLoadField(JSObject* object,
-                                                JSObject* holder,
+Handle<Code> LoadStubCompiler::CompileLoadField(Handle<JSObject> object,
+                                                Handle<JSObject> holder,
                                                 int index,
-                                                String* name) {
+                                                Handle<String> name) {
   // ----------- S t a t e -------------
   //  -- r0    : receiver
   //  -- r2    : name
@@ -2874,14 +3072,14 @@
   GenerateLoadMiss(masm(), Code::LOAD_IC);
 
   // Return the generated code.
-  return GetCode(CALLBACKS, name);
+  return TryGetCode(CALLBACKS, name);
 }
 
 
-MaybeObject* LoadStubCompiler::CompileLoadConstant(JSObject* object,
-                                                   JSObject* holder,
-                                                   Object* value,
-                                                   String* name) {
+Handle<Code> LoadStubCompiler::CompileLoadConstant(Handle<JSObject> object,
+                                                   Handle<JSObject> holder,
+                                                   Handle<Object> value,
+                                                   Handle<String> name) {
   // ----------- S t a t e -------------
   //  -- r0    : receiver
   //  -- r2    : name
@@ -2908,7 +3106,7 @@
   // -----------------------------------
   Label miss;
 
-  LookupResult lookup;
+  LookupResult lookup(isolate());
   LookupPostInterceptor(holder, name, &lookup);
   GenerateLoadInterceptor(object,
                           holder,
@@ -2924,15 +3122,16 @@
   GenerateLoadMiss(masm(), Code::LOAD_IC);
 
   // Return the generated code.
-  return GetCode(INTERCEPTOR, name);
+  return TryGetCode(INTERCEPTOR, name);
 }
 
 
-MaybeObject* LoadStubCompiler::CompileLoadGlobal(JSObject* object,
-                                                 GlobalObject* holder,
-                                                 JSGlobalPropertyCell* cell,
-                                                 String* name,
-                                                 bool is_dont_delete) {
+Handle<Code> LoadStubCompiler::CompileLoadGlobal(
+    Handle<JSObject> object,
+    Handle<GlobalObject> holder,
+    Handle<JSGlobalPropertyCell> cell,
+    Handle<String> name,
+    bool is_dont_delete) {
   // ----------- S t a t e -------------
   //  -- r0    : receiver
   //  -- r2    : name
@@ -2943,7 +3142,7 @@
   // If the object is the holder then we know that it's a global
   // object which can only happen for contextual calls. In this case,
   // the receiver cannot be a smi.
-  if (object != holder) {
+  if (!object.is_identical_to(holder)) {
     __ JumpIfSmi(r0, &miss);
   }
 
@@ -2951,7 +3150,7 @@
   CheckPrototypes(object, r0, holder, r3, r4, r1, name, &miss);
 
   // Get the value from the cell.
-  __ mov(r3, Operand(Handle<JSGlobalPropertyCell>(cell)));
+  __ mov(r3, Operand(cell));
   __ ldr(r4, FieldMemOperand(r3, JSGlobalPropertyCell::kValueOffset));
 
   // Check for deleted property if property can actually be deleted.
@@ -2975,9 +3174,9 @@
 }
 
 
-MaybeObject* KeyedLoadStubCompiler::CompileLoadField(String* name,
-                                                     JSObject* receiver,
-                                                     JSObject* holder,
+Handle<Code> KeyedLoadStubCompiler::CompileLoadField(Handle<String> name,
+                                                     Handle<JSObject> receiver,
+                                                     Handle<JSObject> holder,
                                                      int index) {
   // ----------- S t a t e -------------
   //  -- lr    : return address
@@ -2987,7 +3186,7 @@
   Label miss;
 
   // Check the key is the cached one.
-  __ cmp(r0, Operand(Handle<String>(name)));
+  __ cmp(r0, Operand(name));
   __ b(ne, &miss);
 
   GenerateLoadField(receiver, holder, r1, r2, r3, r4, index, name, &miss);
@@ -3024,14 +3223,15 @@
   __ bind(&miss);
   GenerateLoadMiss(masm(), Code::KEYED_LOAD_IC);
 
-  return GetCode(CALLBACKS, name);
+  return TryGetCode(CALLBACKS, name);
 }
 
 
-MaybeObject* KeyedLoadStubCompiler::CompileLoadConstant(String* name,
-                                                        JSObject* receiver,
-                                                        JSObject* holder,
-                                                        Object* value) {
+Handle<Code> KeyedLoadStubCompiler::CompileLoadConstant(
+    Handle<String> name,
+    Handle<JSObject> receiver,
+    Handle<JSObject> holder,
+    Handle<Object> value) {
   // ----------- S t a t e -------------
   //  -- lr    : return address
   //  -- r0    : key
@@ -3040,7 +3240,7 @@
   Label miss;
 
   // Check the key is the cached one.
-  __ cmp(r0, Operand(Handle<String>(name)));
+  __ cmp(r0, Operand(name));
   __ b(ne, &miss);
 
   GenerateLoadConstant(receiver, holder, r1, r2, r3, r4, value, name, &miss);
@@ -3066,7 +3266,7 @@
   __ cmp(r0, Operand(Handle<String>(name)));
   __ b(ne, &miss);
 
-  LookupResult lookup;
+  LookupResult lookup(isolate());
   LookupPostInterceptor(holder, name, &lookup);
   GenerateLoadInterceptor(receiver,
                           holder,
@@ -3081,11 +3281,12 @@
   __ bind(&miss);
   GenerateLoadMiss(masm(), Code::KEYED_LOAD_IC);
 
-  return GetCode(INTERCEPTOR, name);
+  return TryGetCode(INTERCEPTOR, name);
 }
 
 
-MaybeObject* KeyedLoadStubCompiler::CompileLoadArrayLength(String* name) {
+Handle<Code> KeyedLoadStubCompiler::CompileLoadArrayLength(
+    Handle<String> name) {
   // ----------- S t a t e -------------
   //  -- lr    : return address
   //  -- r0    : key
@@ -3094,7 +3295,7 @@
   Label miss;
 
   // Check the key is the cached one.
-  __ cmp(r0, Operand(Handle<String>(name)));
+  __ cmp(r0, Operand(name));
   __ b(ne, &miss);
 
   GenerateLoadArrayLength(masm(), r1, r2, &miss);
@@ -3105,7 +3306,8 @@
 }
 
 
-MaybeObject* KeyedLoadStubCompiler::CompileLoadStringLength(String* name) {
+Handle<Code> KeyedLoadStubCompiler::CompileLoadStringLength(
+    Handle<String> name) {
   // ----------- S t a t e -------------
   //  -- lr    : return address
   //  -- r0    : key
@@ -3117,7 +3319,7 @@
   __ IncrementCounter(counters->keyed_load_string_length(), 1, r2, r3);
 
   // Check the key is the cached one.
-  __ cmp(r0, Operand(Handle<String>(name)));
+  __ cmp(r0, Operand(name));
   __ b(ne, &miss);
 
   GenerateLoadStringLength(masm(), r1, r2, r3, &miss, true);
@@ -3130,7 +3332,8 @@
 }
 
 
-MaybeObject* KeyedLoadStubCompiler::CompileLoadFunctionPrototype(String* name) {
+Handle<Code> KeyedLoadStubCompiler::CompileLoadFunctionPrototype(
+    Handle<String> name) {
   // ----------- S t a t e -------------
   //  -- lr    : return address
   //  -- r0    : key
@@ -3142,7 +3345,7 @@
   __ IncrementCounter(counters->keyed_load_function_prototype(), 1, r2, r3);
 
   // Check the name hasn't changed.
-  __ cmp(r0, Operand(Handle<String>(name)));
+  __ cmp(r0, Operand(name));
   __ b(ne, &miss);
 
   GenerateLoadFunctionPrototype(masm(), r1, r2, r3, &miss);
@@ -3154,33 +3357,29 @@
 }
 
 
-MaybeObject* KeyedLoadStubCompiler::CompileLoadElement(Map* receiver_map) {
+Handle<Code> KeyedLoadStubCompiler::CompileLoadElement(
+    Handle<Map> receiver_map) {
   // ----------- S t a t e -------------
   //  -- lr    : return address
   //  -- r0    : key
   //  -- r1    : receiver
   // -----------------------------------
-  Code* stub;
   ElementsKind elements_kind = receiver_map->elements_kind();
-  MaybeObject* maybe_stub = KeyedLoadElementStub(elements_kind).TryGetCode();
-  if (!maybe_stub->To(&stub)) return maybe_stub;
-  __ DispatchMap(r1,
-                 r2,
-                 Handle<Map>(receiver_map),
-                 Handle<Code>(stub),
-                 DO_SMI_CHECK);
+  Handle<Code> stub = KeyedLoadElementStub(elements_kind).GetCode();
+
+  __ DispatchMap(r1, r2, receiver_map, stub, DO_SMI_CHECK);
 
   Handle<Code> ic = isolate()->builtins()->KeyedLoadIC_Miss();
   __ Jump(ic, RelocInfo::CODE_TARGET);
 
   // Return the generated code.
-  return GetCode(NORMAL, NULL);
+  return GetCode(NORMAL, factory()->empty_string());
 }
 
 
-MaybeObject* KeyedLoadStubCompiler::CompileLoadPolymorphic(
-    MapList* receiver_maps,
-    CodeList* handler_ics) {
+Handle<Code> KeyedLoadStubCompiler::CompileLoadPolymorphic(
+    MapHandleList* receiver_maps,
+    CodeHandleList* handler_ics) {
   // ----------- S t a t e -------------
   //  -- lr    : return address
   //  -- r0    : key
@@ -3192,11 +3391,9 @@
   int receiver_count = receiver_maps->length();
   __ ldr(r2, FieldMemOperand(r1, HeapObject::kMapOffset));
   for (int current = 0; current < receiver_count; ++current) {
-    Handle<Map> map(receiver_maps->at(current));
-    Handle<Code> code(handler_ics->at(current));
-    __ mov(ip, Operand(map));
+    __ mov(ip, Operand(receiver_maps->at(current)));
     __ cmp(r2, ip);
-    __ Jump(code, RelocInfo::CODE_TARGET, eq);
+    __ Jump(handler_ics->at(current), RelocInfo::CODE_TARGET, eq);
   }
 
   __ bind(&miss);
@@ -3204,14 +3401,14 @@
   __ Jump(miss_ic, RelocInfo::CODE_TARGET, al);
 
   // Return the generated code.
-  return GetCode(NORMAL, NULL, MEGAMORPHIC);
+  return GetCode(NORMAL, factory()->empty_string(), MEGAMORPHIC);
 }
 
 
-MaybeObject* KeyedStoreStubCompiler::CompileStoreField(JSObject* object,
+Handle<Code> KeyedStoreStubCompiler::CompileStoreField(Handle<JSObject> object,
                                                        int index,
-                                                       Map* transition,
-                                                       String* name) {
+                                                       Handle<Map> transition,
+                                                       Handle<String> name) {
   // ----------- S t a t e -------------
   //  -- r0    : value
   //  -- r1    : name
@@ -3224,17 +3421,12 @@
   __ IncrementCounter(counters->keyed_store_field(), 1, r3, r4);
 
   // Check that the name has not changed.
-  __ cmp(r1, Operand(Handle<String>(name)));
+  __ cmp(r1, Operand(name));
   __ b(ne, &miss);
 
   // r3 is used as scratch register. r1 and r2 keep their values if a jump to
   // the miss label is generated.
-  GenerateStoreField(masm(),
-                     object,
-                     index,
-                     transition,
-                     r2, r1, r3,
-                     &miss);
+  GenerateStoreField(masm(), object, index, transition, r2, r1, r3, &miss);
   __ bind(&miss);
 
   __ DecrementCounter(counters->keyed_store_field(), 1, r3, r4);
@@ -3242,11 +3434,12 @@
   __ Jump(ic, RelocInfo::CODE_TARGET);
 
   // Return the generated code.
-  return GetCode(transition == NULL ? FIELD : MAP_TRANSITION, name);
+  return GetCode(transition.is_null() ? FIELD : MAP_TRANSITION, name);
 }
 
 
-MaybeObject* KeyedStoreStubCompiler::CompileStoreElement(Map* receiver_map) {
+Handle<Code> KeyedStoreStubCompiler::CompileStoreElement(
+    Handle<Map> receiver_map) {
   // ----------- S t a t e -------------
   //  -- r0    : value
   //  -- r1    : key
@@ -3254,30 +3447,25 @@
   //  -- lr    : return address
   //  -- r3    : scratch
   // -----------------------------------
-  Code* stub;
   ElementsKind elements_kind = receiver_map->elements_kind();
   bool is_js_array = receiver_map->instance_type() == JS_ARRAY_TYPE;
-  MaybeObject* maybe_stub =
-      KeyedStoreElementStub(is_js_array, elements_kind).TryGetCode();
-  if (!maybe_stub->To(&stub)) return maybe_stub;
-  __ DispatchMap(r2,
-                 r3,
-                 Handle<Map>(receiver_map),
-                 Handle<Code>(stub),
-                 DO_SMI_CHECK);
+  Handle<Code> stub =
+      KeyedStoreElementStub(is_js_array, elements_kind).GetCode();
+
+  __ DispatchMap(r2, r3, receiver_map, stub, DO_SMI_CHECK);
 
   Handle<Code> ic = isolate()->builtins()->KeyedStoreIC_Miss();
   __ Jump(ic, RelocInfo::CODE_TARGET);
 
   // Return the generated code.
-  return GetCode(NORMAL, NULL);
+  return GetCode(NORMAL, factory()->empty_string());
 }
 
 
-MaybeObject* KeyedStoreStubCompiler::CompileStorePolymorphic(
-    MapList* receiver_maps,
-    CodeList* handler_stubs,
-    MapList* transitioned_maps) {
+Handle<Code> KeyedStoreStubCompiler::CompileStorePolymorphic(
+    MapHandleList* receiver_maps,
+    CodeHandleList* handler_stubs,
+    MapHandleList* transitioned_maps) {
   // ----------- S t a t e -------------
   //  -- r0    : value
   //  -- r1    : key
@@ -3291,17 +3479,15 @@
   int receiver_count = receiver_maps->length();
   __ ldr(r3, FieldMemOperand(r2, HeapObject::kMapOffset));
   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));
+    __ mov(ip, Operand(receiver_maps->at(i)));
     __ cmp(r3, ip);
-    if (transitioned_maps->at(i) == NULL) {
-      __ Jump(code, RelocInfo::CODE_TARGET, eq);
+    if (transitioned_maps->at(i).is_null()) {
+      __ Jump(handler_stubs->at(i), 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);
+      __ b(ne, &next_map);
+      __ mov(r3, Operand(transitioned_maps->at(i)));
+      __ Jump(handler_stubs->at(i), RelocInfo::CODE_TARGET, al);
       __ bind(&next_map);
     }
   }
@@ -3311,7 +3497,7 @@
   __ Jump(miss_ic, RelocInfo::CODE_TARGET, al);
 
   // Return the generated code.
-  return GetCode(NORMAL, NULL, MEGAMORPHIC);
+  return GetCode(NORMAL, factory()->empty_string(), MEGAMORPHIC);
 }