diff --git a/src/x87/codegen-x87.cc b/src/x87/codegen-x87.cc
new file mode 100644
index 0000000..e33959e
--- /dev/null
+++ b/src/x87/codegen-x87.cc
@@ -0,0 +1,618 @@
+// Copyright 2012 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/v8.h"
+
+#if V8_TARGET_ARCH_X87
+
+#include "src/codegen.h"
+#include "src/heap/heap.h"
+#include "src/macro-assembler.h"
+
+namespace v8 {
+namespace internal {
+
+
+// -------------------------------------------------------------------------
+// Platform-specific RuntimeCallHelper functions.
+
+void StubRuntimeCallHelper::BeforeCall(MacroAssembler* masm) const {
+  masm->EnterFrame(StackFrame::INTERNAL);
+  DCHECK(!masm->has_frame());
+  masm->set_has_frame(true);
+}
+
+
+void StubRuntimeCallHelper::AfterCall(MacroAssembler* masm) const {
+  masm->LeaveFrame(StackFrame::INTERNAL);
+  DCHECK(masm->has_frame());
+  masm->set_has_frame(false);
+}
+
+
+#define __ masm.
+
+
+UnaryMathFunction CreateExpFunction() {
+  // No SSE2 support
+  return &std::exp;
+}
+
+
+UnaryMathFunction CreateSqrtFunction() {
+  // No SSE2 support
+  return &std::sqrt;
+}
+
+
+// Helper functions for CreateMemMoveFunction.
+#undef __
+#define __ ACCESS_MASM(masm)
+
+enum Direction { FORWARD, BACKWARD };
+enum Alignment { MOVE_ALIGNED, MOVE_UNALIGNED };
+
+
+void MemMoveEmitPopAndReturn(MacroAssembler* masm) {
+  __ pop(esi);
+  __ pop(edi);
+  __ ret(0);
+}
+
+
+#undef __
+#define __ masm.
+
+
+class LabelConverter {
+ public:
+  explicit LabelConverter(byte* buffer) : buffer_(buffer) {}
+  int32_t address(Label* l) const {
+    return reinterpret_cast<int32_t>(buffer_) + l->pos();
+  }
+ private:
+  byte* buffer_;
+};
+
+
+MemMoveFunction CreateMemMoveFunction() {
+  size_t actual_size;
+  // Allocate buffer in executable space.
+  byte* buffer =
+      static_cast<byte*>(base::OS::Allocate(1 * KB, &actual_size, true));
+  if (buffer == NULL) return NULL;
+  MacroAssembler masm(NULL, buffer, static_cast<int>(actual_size));
+  LabelConverter conv(buffer);
+
+  // Generated code is put into a fixed, unmovable buffer, and not into
+  // the V8 heap. We can't, and don't, refer to any relocatable addresses
+  // (e.g. the JavaScript nan-object).
+
+  // 32-bit C declaration function calls pass arguments on stack.
+
+  // Stack layout:
+  // esp[12]: Third argument, size.
+  // esp[8]: Second argument, source pointer.
+  // esp[4]: First argument, destination pointer.
+  // esp[0]: return address
+
+  const int kDestinationOffset = 1 * kPointerSize;
+  const int kSourceOffset = 2 * kPointerSize;
+  const int kSizeOffset = 3 * kPointerSize;
+
+  int stack_offset = 0;  // Update if we change the stack height.
+
+  Label backward, backward_much_overlap;
+  Label forward_much_overlap, small_size, medium_size, pop_and_return;
+  __ push(edi);
+  __ push(esi);
+  stack_offset += 2 * kPointerSize;
+  Register dst = edi;
+  Register src = esi;
+  Register count = ecx;
+  __ mov(dst, Operand(esp, stack_offset + kDestinationOffset));
+  __ mov(src, Operand(esp, stack_offset + kSourceOffset));
+  __ mov(count, Operand(esp, stack_offset + kSizeOffset));
+
+  __ cmp(dst, src);
+  __ j(equal, &pop_and_return);
+
+  // No SSE2.
+  Label forward;
+  __ cmp(count, 0);
+  __ j(equal, &pop_and_return);
+  __ cmp(dst, src);
+  __ j(above, &backward);
+  __ jmp(&forward);
+  {
+    // Simple forward copier.
+    Label forward_loop_1byte, forward_loop_4byte;
+    __ bind(&forward_loop_4byte);
+    __ mov(eax, Operand(src, 0));
+    __ sub(count, Immediate(4));
+    __ add(src, Immediate(4));
+    __ mov(Operand(dst, 0), eax);
+    __ add(dst, Immediate(4));
+    __ bind(&forward);  // Entry point.
+    __ cmp(count, 3);
+    __ j(above, &forward_loop_4byte);
+    __ bind(&forward_loop_1byte);
+    __ cmp(count, 0);
+    __ j(below_equal, &pop_and_return);
+    __ mov_b(eax, Operand(src, 0));
+    __ dec(count);
+    __ inc(src);
+    __ mov_b(Operand(dst, 0), eax);
+    __ inc(dst);
+    __ jmp(&forward_loop_1byte);
+  }
+  {
+    // Simple backward copier.
+    Label backward_loop_1byte, backward_loop_4byte, entry_shortcut;
+    __ bind(&backward);
+    __ add(src, count);
+    __ add(dst, count);
+    __ cmp(count, 3);
+    __ j(below_equal, &entry_shortcut);
+
+    __ bind(&backward_loop_4byte);
+    __ sub(src, Immediate(4));
+    __ sub(count, Immediate(4));
+    __ mov(eax, Operand(src, 0));
+    __ sub(dst, Immediate(4));
+    __ mov(Operand(dst, 0), eax);
+    __ cmp(count, 3);
+    __ j(above, &backward_loop_4byte);
+    __ bind(&backward_loop_1byte);
+    __ cmp(count, 0);
+    __ j(below_equal, &pop_and_return);
+    __ bind(&entry_shortcut);
+    __ dec(src);
+    __ dec(count);
+    __ mov_b(eax, Operand(src, 0));
+    __ dec(dst);
+    __ mov_b(Operand(dst, 0), eax);
+    __ jmp(&backward_loop_1byte);
+  }
+
+  __ bind(&pop_and_return);
+  MemMoveEmitPopAndReturn(&masm);
+
+  CodeDesc desc;
+  masm.GetCode(&desc);
+  DCHECK(!RelocInfo::RequiresRelocation(desc));
+  CpuFeatures::FlushICache(buffer, actual_size);
+  base::OS::ProtectCode(buffer, actual_size);
+  // TODO(jkummerow): It would be nice to register this code creation event
+  // with the PROFILE / GDBJIT system.
+  return FUNCTION_CAST<MemMoveFunction>(buffer);
+}
+
+
+#undef __
+
+// -------------------------------------------------------------------------
+// Code generators
+
+#define __ ACCESS_MASM(masm)
+
+
+void ElementsTransitionGenerator::GenerateMapChangeElementsTransition(
+    MacroAssembler* masm,
+    Register receiver,
+    Register key,
+    Register value,
+    Register target_map,
+    AllocationSiteMode mode,
+    Label* allocation_memento_found) {
+  Register scratch = edi;
+  DCHECK(!AreAliased(receiver, key, value, target_map, scratch));
+
+  if (mode == TRACK_ALLOCATION_SITE) {
+    DCHECK(allocation_memento_found != NULL);
+    __ JumpIfJSArrayHasAllocationMemento(
+        receiver, scratch, allocation_memento_found);
+  }
+
+  // Set transitioned map.
+  __ mov(FieldOperand(receiver, HeapObject::kMapOffset), target_map);
+  __ RecordWriteField(receiver, HeapObject::kMapOffset, target_map, scratch,
+                      kDontSaveFPRegs, EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
+}
+
+
+void ElementsTransitionGenerator::GenerateSmiToDouble(
+    MacroAssembler* masm,
+    Register receiver,
+    Register key,
+    Register value,
+    Register target_map,
+    AllocationSiteMode mode,
+    Label* fail) {
+  // Return address is on the stack.
+  DCHECK(receiver.is(edx));
+  DCHECK(key.is(ecx));
+  DCHECK(value.is(eax));
+  DCHECK(target_map.is(ebx));
+
+  Label loop, entry, convert_hole, gc_required, only_change_map;
+
+  if (mode == TRACK_ALLOCATION_SITE) {
+    __ JumpIfJSArrayHasAllocationMemento(edx, edi, fail);
+  }
+
+  // Check for empty arrays, which only require a map transition and no changes
+  // to the backing store.
+  __ mov(edi, FieldOperand(edx, JSObject::kElementsOffset));
+  __ cmp(edi, Immediate(masm->isolate()->factory()->empty_fixed_array()));
+  __ j(equal, &only_change_map);
+
+  __ push(eax);
+  __ push(ebx);
+
+  __ mov(edi, FieldOperand(edi, FixedArray::kLengthOffset));
+
+  // Allocate new FixedDoubleArray.
+  // edx: receiver
+  // edi: length of source FixedArray (smi-tagged)
+  AllocationFlags flags =
+      static_cast<AllocationFlags>(TAG_OBJECT | DOUBLE_ALIGNMENT);
+  __ Allocate(FixedDoubleArray::kHeaderSize, times_8, edi,
+              REGISTER_VALUE_IS_SMI, eax, ebx, no_reg, &gc_required, flags);
+
+  // eax: destination FixedDoubleArray
+  // edi: number of elements
+  // edx: receiver
+  __ mov(FieldOperand(eax, HeapObject::kMapOffset),
+         Immediate(masm->isolate()->factory()->fixed_double_array_map()));
+  __ mov(FieldOperand(eax, FixedDoubleArray::kLengthOffset), edi);
+  __ mov(esi, FieldOperand(edx, JSObject::kElementsOffset));
+  // Replace receiver's backing store with newly created FixedDoubleArray.
+  __ mov(FieldOperand(edx, JSObject::kElementsOffset), eax);
+  __ mov(ebx, eax);
+  __ RecordWriteField(edx, JSObject::kElementsOffset, ebx, edi, kDontSaveFPRegs,
+                      EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
+
+  __ mov(edi, FieldOperand(esi, FixedArray::kLengthOffset));
+
+  // Prepare for conversion loop.
+  ExternalReference canonical_the_hole_nan_reference =
+      ExternalReference::address_of_the_hole_nan();
+  __ jmp(&entry);
+
+  // Call into runtime if GC is required.
+  __ bind(&gc_required);
+  // Restore registers before jumping into runtime.
+  __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
+  __ pop(ebx);
+  __ pop(eax);
+  __ jmp(fail);
+
+  // Convert and copy elements
+  // esi: source FixedArray
+  __ bind(&loop);
+  __ mov(ebx, FieldOperand(esi, edi, times_2, FixedArray::kHeaderSize));
+  // ebx: current element from source
+  // edi: index of current element
+  __ JumpIfNotSmi(ebx, &convert_hole);
+
+  // Normal smi, convert it to double and store.
+  __ SmiUntag(ebx);
+  __ push(ebx);
+  __ fild_s(Operand(esp, 0));
+  __ pop(ebx);
+  __ fstp_d(FieldOperand(eax, edi, times_4, FixedDoubleArray::kHeaderSize));
+  __ jmp(&entry);
+
+  // Found hole, store hole_nan_as_double instead.
+  __ bind(&convert_hole);
+
+  if (FLAG_debug_code) {
+    __ cmp(ebx, masm->isolate()->factory()->the_hole_value());
+    __ Assert(equal, kObjectFoundInSmiOnlyArray);
+  }
+
+  __ fld_d(Operand::StaticVariable(canonical_the_hole_nan_reference));
+  __ fstp_d(FieldOperand(eax, edi, times_4, FixedDoubleArray::kHeaderSize));
+
+  __ bind(&entry);
+  __ sub(edi, Immediate(Smi::FromInt(1)));
+  __ j(not_sign, &loop);
+
+  __ pop(ebx);
+  __ pop(eax);
+
+  // Restore esi.
+  __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
+
+  __ bind(&only_change_map);
+  // eax: value
+  // ebx: target map
+  // Set transitioned map.
+  __ mov(FieldOperand(edx, HeapObject::kMapOffset), ebx);
+  __ RecordWriteField(edx, HeapObject::kMapOffset, ebx, edi, kDontSaveFPRegs,
+                      OMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
+}
+
+
+void ElementsTransitionGenerator::GenerateDoubleToObject(
+    MacroAssembler* masm,
+    Register receiver,
+    Register key,
+    Register value,
+    Register target_map,
+    AllocationSiteMode mode,
+    Label* fail) {
+  // Return address is on the stack.
+  DCHECK(receiver.is(edx));
+  DCHECK(key.is(ecx));
+  DCHECK(value.is(eax));
+  DCHECK(target_map.is(ebx));
+
+  Label loop, entry, convert_hole, gc_required, only_change_map, success;
+
+  if (mode == TRACK_ALLOCATION_SITE) {
+    __ JumpIfJSArrayHasAllocationMemento(edx, edi, fail);
+  }
+
+  // Check for empty arrays, which only require a map transition and no changes
+  // to the backing store.
+  __ mov(edi, FieldOperand(edx, JSObject::kElementsOffset));
+  __ cmp(edi, Immediate(masm->isolate()->factory()->empty_fixed_array()));
+  __ j(equal, &only_change_map);
+
+  __ push(eax);
+  __ push(edx);
+  __ push(ebx);
+
+  __ mov(ebx, FieldOperand(edi, FixedDoubleArray::kLengthOffset));
+
+  // Allocate new FixedArray.
+  // ebx: length of source FixedDoubleArray (smi-tagged)
+  __ lea(edi, Operand(ebx, times_2, FixedArray::kHeaderSize));
+  __ Allocate(edi, eax, esi, no_reg, &gc_required, TAG_OBJECT);
+
+  // eax: destination FixedArray
+  // ebx: number of elements
+  __ mov(FieldOperand(eax, HeapObject::kMapOffset),
+         Immediate(masm->isolate()->factory()->fixed_array_map()));
+  __ mov(FieldOperand(eax, FixedArray::kLengthOffset), ebx);
+  __ mov(edi, FieldOperand(edx, JSObject::kElementsOffset));
+
+  __ jmp(&entry);
+
+  // ebx: target map
+  // edx: receiver
+  // Set transitioned map.
+  __ bind(&only_change_map);
+  __ mov(FieldOperand(edx, HeapObject::kMapOffset), ebx);
+  __ RecordWriteField(edx, HeapObject::kMapOffset, ebx, edi, kDontSaveFPRegs,
+                      OMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
+  __ jmp(&success);
+
+  // Call into runtime if GC is required.
+  __ bind(&gc_required);
+  __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
+  __ pop(ebx);
+  __ pop(edx);
+  __ pop(eax);
+  __ jmp(fail);
+
+  // Box doubles into heap numbers.
+  // edi: source FixedDoubleArray
+  // eax: destination FixedArray
+  __ bind(&loop);
+  // ebx: index of current element (smi-tagged)
+  uint32_t offset = FixedDoubleArray::kHeaderSize + sizeof(kHoleNanLower32);
+  __ cmp(FieldOperand(edi, ebx, times_4, offset), Immediate(kHoleNanUpper32));
+  __ j(equal, &convert_hole);
+
+  // Non-hole double, copy value into a heap number.
+  __ AllocateHeapNumber(edx, esi, no_reg, &gc_required);
+  // edx: new heap number
+  __ mov(esi, FieldOperand(edi, ebx, times_4, FixedDoubleArray::kHeaderSize));
+  __ mov(FieldOperand(edx, HeapNumber::kValueOffset), esi);
+  __ mov(esi, FieldOperand(edi, ebx, times_4, offset));
+  __ mov(FieldOperand(edx, HeapNumber::kValueOffset + kPointerSize), esi);
+  __ mov(FieldOperand(eax, ebx, times_2, FixedArray::kHeaderSize), edx);
+  __ mov(esi, ebx);
+  __ RecordWriteArray(eax, edx, esi, kDontSaveFPRegs, EMIT_REMEMBERED_SET,
+                      OMIT_SMI_CHECK);
+  __ jmp(&entry, Label::kNear);
+
+  // Replace the-hole NaN with the-hole pointer.
+  __ bind(&convert_hole);
+  __ mov(FieldOperand(eax, ebx, times_2, FixedArray::kHeaderSize),
+         masm->isolate()->factory()->the_hole_value());
+
+  __ bind(&entry);
+  __ sub(ebx, Immediate(Smi::FromInt(1)));
+  __ j(not_sign, &loop);
+
+  __ pop(ebx);
+  __ pop(edx);
+  // ebx: target map
+  // edx: receiver
+  // Set transitioned map.
+  __ mov(FieldOperand(edx, HeapObject::kMapOffset), ebx);
+  __ RecordWriteField(edx, HeapObject::kMapOffset, ebx, edi, kDontSaveFPRegs,
+                      OMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
+  // Replace receiver's backing store with newly created and filled FixedArray.
+  __ mov(FieldOperand(edx, JSObject::kElementsOffset), eax);
+  __ RecordWriteField(edx, JSObject::kElementsOffset, eax, edi, kDontSaveFPRegs,
+                      EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
+
+  // Restore registers.
+  __ pop(eax);
+  __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
+
+  __ bind(&success);
+}
+
+
+void StringCharLoadGenerator::Generate(MacroAssembler* masm,
+                                       Factory* factory,
+                                       Register string,
+                                       Register index,
+                                       Register result,
+                                       Label* call_runtime) {
+  // Fetch the instance type of the receiver into result register.
+  __ mov(result, FieldOperand(string, HeapObject::kMapOffset));
+  __ movzx_b(result, FieldOperand(result, Map::kInstanceTypeOffset));
+
+  // We need special handling for indirect strings.
+  Label check_sequential;
+  __ test(result, Immediate(kIsIndirectStringMask));
+  __ j(zero, &check_sequential, Label::kNear);
+
+  // Dispatch on the indirect string shape: slice or cons.
+  Label cons_string;
+  __ test(result, Immediate(kSlicedNotConsMask));
+  __ j(zero, &cons_string, Label::kNear);
+
+  // Handle slices.
+  Label indirect_string_loaded;
+  __ mov(result, FieldOperand(string, SlicedString::kOffsetOffset));
+  __ SmiUntag(result);
+  __ add(index, result);
+  __ mov(string, FieldOperand(string, SlicedString::kParentOffset));
+  __ jmp(&indirect_string_loaded, Label::kNear);
+
+  // Handle cons strings.
+  // Check whether the right hand side is the empty string (i.e. if
+  // this is really a flat string in a cons string). If that is not
+  // the case we would rather go to the runtime system now to flatten
+  // the string.
+  __ bind(&cons_string);
+  __ cmp(FieldOperand(string, ConsString::kSecondOffset),
+         Immediate(factory->empty_string()));
+  __ j(not_equal, call_runtime);
+  __ mov(string, FieldOperand(string, ConsString::kFirstOffset));
+
+  __ bind(&indirect_string_loaded);
+  __ mov(result, FieldOperand(string, HeapObject::kMapOffset));
+  __ movzx_b(result, FieldOperand(result, Map::kInstanceTypeOffset));
+
+  // Distinguish sequential and external strings. Only these two string
+  // representations can reach here (slices and flat cons strings have been
+  // reduced to the underlying sequential or external string).
+  Label seq_string;
+  __ bind(&check_sequential);
+  STATIC_ASSERT(kSeqStringTag == 0);
+  __ test(result, Immediate(kStringRepresentationMask));
+  __ j(zero, &seq_string, Label::kNear);
+
+  // Handle external strings.
+  Label one_byte_external, done;
+  if (FLAG_debug_code) {
+    // Assert that we do not have a cons or slice (indirect strings) here.
+    // Sequential strings have already been ruled out.
+    __ test(result, Immediate(kIsIndirectStringMask));
+    __ Assert(zero, kExternalStringExpectedButNotFound);
+  }
+  // Rule out short external strings.
+  STATIC_ASSERT(kShortExternalStringTag != 0);
+  __ test_b(result, kShortExternalStringMask);
+  __ j(not_zero, call_runtime);
+  // Check encoding.
+  STATIC_ASSERT(kTwoByteStringTag == 0);
+  __ test_b(result, kStringEncodingMask);
+  __ mov(result, FieldOperand(string, ExternalString::kResourceDataOffset));
+  __ j(not_equal, &one_byte_external, Label::kNear);
+  // Two-byte string.
+  __ movzx_w(result, Operand(result, index, times_2, 0));
+  __ jmp(&done, Label::kNear);
+  __ bind(&one_byte_external);
+  // One-byte string.
+  __ movzx_b(result, Operand(result, index, times_1, 0));
+  __ jmp(&done, Label::kNear);
+
+  // Dispatch on the encoding: one-byte or two-byte.
+  Label one_byte;
+  __ bind(&seq_string);
+  STATIC_ASSERT((kStringEncodingMask & kOneByteStringTag) != 0);
+  STATIC_ASSERT((kStringEncodingMask & kTwoByteStringTag) == 0);
+  __ test(result, Immediate(kStringEncodingMask));
+  __ j(not_zero, &one_byte, Label::kNear);
+
+  // Two-byte string.
+  // Load the two-byte character code into the result register.
+  __ movzx_w(result, FieldOperand(string,
+                                  index,
+                                  times_2,
+                                  SeqTwoByteString::kHeaderSize));
+  __ jmp(&done, Label::kNear);
+
+  // One-byte string.
+  // Load the byte into the result register.
+  __ bind(&one_byte);
+  __ movzx_b(result, FieldOperand(string,
+                                  index,
+                                  times_1,
+                                  SeqOneByteString::kHeaderSize));
+  __ bind(&done);
+}
+
+
+#undef __
+
+
+CodeAgingHelper::CodeAgingHelper() {
+  DCHECK(young_sequence_.length() == kNoCodeAgeSequenceLength);
+  CodePatcher patcher(young_sequence_.start(), young_sequence_.length());
+  patcher.masm()->push(ebp);
+  patcher.masm()->mov(ebp, esp);
+  patcher.masm()->push(esi);
+  patcher.masm()->push(edi);
+}
+
+
+#ifdef DEBUG
+bool CodeAgingHelper::IsOld(byte* candidate) const {
+  return *candidate == kCallOpcode;
+}
+#endif
+
+
+bool Code::IsYoungSequence(Isolate* isolate, byte* sequence) {
+  bool result = isolate->code_aging_helper()->IsYoung(sequence);
+  DCHECK(result || isolate->code_aging_helper()->IsOld(sequence));
+  return result;
+}
+
+
+void Code::GetCodeAgeAndParity(Isolate* isolate, byte* sequence, Age* age,
+                               MarkingParity* parity) {
+  if (IsYoungSequence(isolate, sequence)) {
+    *age = kNoAgeCodeAge;
+    *parity = NO_MARKING_PARITY;
+  } else {
+    sequence++;  // Skip the kCallOpcode byte
+    Address target_address = sequence + *reinterpret_cast<int*>(sequence) +
+        Assembler::kCallTargetAddressOffset;
+    Code* stub = GetCodeFromTargetAddress(target_address);
+    GetCodeAgeAndParity(stub, age, parity);
+  }
+}
+
+
+void Code::PatchPlatformCodeAge(Isolate* isolate,
+                                byte* sequence,
+                                Code::Age age,
+                                MarkingParity parity) {
+  uint32_t young_length = isolate->code_aging_helper()->young_sequence_length();
+  if (age == kNoAgeCodeAge) {
+    isolate->code_aging_helper()->CopyYoungSequenceTo(sequence);
+    CpuFeatures::FlushICache(sequence, young_length);
+  } else {
+    Code* stub = GetCodeAgeStub(isolate, age, parity);
+    CodePatcher patcher(sequence, young_length);
+    patcher.masm()->call(stub->instruction_start(), RelocInfo::NONE32);
+  }
+}
+
+
+} }  // namespace v8::internal
+
+#endif  // V8_TARGET_ARCH_X87