src/ia32/lithium-codegen-ia32.cc

// Copyright 2012 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
//     * Neither the name of Google Inc. nor the names of its
//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include "v8.h"

#if defined(V8_TARGET_ARCH_IA32)

#include "ia32/lithium-codegen-ia32.h"
#include "ic.h"
#include "code-stubs.h"
#include "deoptimizer.h"
#include "stub-cache.h"
#include "codegen.h"

namespace v8 {
namespace internal {


static SaveFPRegsMode GetSaveFPRegsMode() {
  // We don't need to save floating point regs when generating the snapshot
  return CpuFeatures::IsSafeForSnapshot(SSE2) ? kSaveFPRegs : kDontSaveFPRegs;
}


// When invoking builtins, we need to record the safepoint in the middle of
// the invoke instruction sequence generated by the macro assembler.
class SafepointGenerator : public CallWrapper {
 public:
  SafepointGenerator(LCodeGen* codegen,
                     LPointerMap* pointers,
                     Safepoint::DeoptMode mode)
      : codegen_(codegen),
        pointers_(pointers),
        deopt_mode_(mode) {}
  virtual ~SafepointGenerator() { }

  virtual void BeforeCall(int call_size) const {}

  virtual void AfterCall() const {
    codegen_->RecordSafepoint(pointers_, deopt_mode_);
  }

 private:
  LCodeGen* codegen_;
  LPointerMap* pointers_;
  Safepoint::DeoptMode deopt_mode_;
};


#define __ masm()->

bool LCodeGen::GenerateCode() {
  HPhase phase("Z_Code generation", chunk());
  ASSERT(is_unused());
  status_ = GENERATING;

  // Open a frame scope to indicate that there is a frame on the stack.  The
  // MANUAL indicates that the scope shouldn't actually generate code to set up
  // the frame (that is done in GeneratePrologue).
  FrameScope frame_scope(masm_, StackFrame::MANUAL);

  support_aligned_spilled_doubles_ = info()->IsOptimizing();

  dynamic_frame_alignment_ = info()->IsOptimizing() &&
      ((chunk()->num_double_slots() > 2 &&
        !chunk()->graph()->is_recursive()) ||
       !info()->osr_ast_id().IsNone());

  return GeneratePrologue() &&
      GenerateBody() &&
      GenerateDeferredCode() &&
      GenerateJumpTable() &&
      GenerateSafepointTable();
}


void LCodeGen::FinishCode(Handle<Code> code) {
  ASSERT(is_done());
  code->set_stack_slots(GetStackSlotCount());
  code->set_safepoint_table_offset(safepoints_.GetCodeOffset());
  if (FLAG_weak_embedded_maps_in_optimized_code) {
    RegisterDependentCodeForEmbeddedMaps(code);
  }
  PopulateDeoptimizationData(code);
  if (!info()->IsStub()) {
    Deoptimizer::EnsureRelocSpaceForLazyDeoptimization(code);
  }
  info()->CommitDependentMaps(code);

  for (int i = 0 ; i < transition_maps_.length(); i++) {
    transition_maps_.at(i)->AddDependentCode(
        DependentCode::kTransitionGroup, code);
  }
  if (graph()->depends_on_empty_array_proto_elements()) {
    isolate()->initial_object_prototype()->map()->AddDependentCode(
        DependentCode::kElementsCantBeAddedGroup, code);
    isolate()->initial_array_prototype()->map()->AddDependentCode(
        DependentCode::kElementsCantBeAddedGroup, code);
  }
}


void LCodeGen::Abort(const char* reason) {
  info()->set_bailout_reason(reason);
  status_ = ABORTED;
}


void LCodeGen::Comment(const char* format, ...) {
  if (!FLAG_code_comments) return;
  char buffer[4 * KB];
  StringBuilder builder(buffer, ARRAY_SIZE(buffer));
  va_list arguments;
  va_start(arguments, format);
  builder.AddFormattedList(format, arguments);
  va_end(arguments);

  // Copy the string before recording it in the assembler to avoid
  // issues when the stack allocated buffer goes out of scope.
  size_t length = builder.position();
  Vector<char> copy = Vector<char>::New(length + 1);
  OS::MemCopy(copy.start(), builder.Finalize(), copy.length());
  masm()->RecordComment(copy.start());
}


bool LCodeGen::GeneratePrologue() {
  ASSERT(is_generating());

  if (info()->IsOptimizing()) {
    ProfileEntryHookStub::MaybeCallEntryHook(masm_);

#ifdef DEBUG
    if (strlen(FLAG_stop_at) > 0 &&
        info_->function()->name()->IsUtf8EqualTo(CStrVector(FLAG_stop_at))) {
      __ int3();
    }
#endif

    // Strict mode functions and builtins need to replace the receiver
    // with undefined when called as functions (without an explicit
    // receiver object). ecx is zero for method calls and non-zero for
    // function calls.
    if (!info_->is_classic_mode() || info_->is_native()) {
      Label ok;
      __ test(ecx, Operand(ecx));
      __ j(zero, &ok, Label::kNear);
      // +1 for return address.
      int receiver_offset = (scope()->num_parameters() + 1) * kPointerSize;
      __ mov(Operand(esp, receiver_offset),
             Immediate(isolate()->factory()->undefined_value()));
      __ bind(&ok);
    }

    if (support_aligned_spilled_doubles_ && dynamic_frame_alignment_) {
      // Move state of dynamic frame alignment into edx.
      __ mov(edx, Immediate(kNoAlignmentPadding));

      Label do_not_pad, align_loop;
      STATIC_ASSERT(kDoubleSize == 2 * kPointerSize);
      // Align esp + 4 to a multiple of 2 * kPointerSize.
      __ test(esp, Immediate(kPointerSize));
      __ j(not_zero, &do_not_pad, Label::kNear);
      __ push(Immediate(0));
      __ mov(ebx, esp);
      __ mov(edx, Immediate(kAlignmentPaddingPushed));
      // Copy arguments, receiver, and return address.
      __ mov(ecx, Immediate(scope()->num_parameters() + 2));

      __ bind(&align_loop);
      __ mov(eax, Operand(ebx, 1 * kPointerSize));
      __ mov(Operand(ebx, 0), eax);
      __ add(Operand(ebx), Immediate(kPointerSize));
      __ dec(ecx);
      __ j(not_zero, &align_loop, Label::kNear);
      __ mov(Operand(ebx, 0), Immediate(kAlignmentZapValue));
      __ bind(&do_not_pad);
    }
  }

  info()->set_prologue_offset(masm_->pc_offset());
  if (NeedsEagerFrame()) {
    ASSERT(!frame_is_built_);
    frame_is_built_ = true;
    __ push(ebp);  // Caller's frame pointer.
    __ mov(ebp, esp);
    info()->AddNoFrameRange(0, masm_->pc_offset());
    __ push(esi);  // Callee's context.
    if (info()->IsStub()) {
      __ push(Immediate(Smi::FromInt(StackFrame::STUB)));
    } else {
      __ push(edi);  // Callee's JS function.
    }
  }

  if (info()->IsOptimizing() &&
      dynamic_frame_alignment_ &&
      FLAG_debug_code) {
    __ test(esp, Immediate(kPointerSize));
    __ Assert(zero, "frame is expected to be aligned");
  }

  // Reserve space for the stack slots needed by the code.
  int slots = GetStackSlotCount();
  ASSERT(slots != 0 || !info()->IsOptimizing());
  if (slots > 0) {
    if (slots == 1) {
      if (dynamic_frame_alignment_) {
        __ push(edx);
      } else {
        __ push(Immediate(kNoAlignmentPadding));
      }
    } else {
      if (FLAG_debug_code) {
        __ sub(Operand(esp), Immediate(slots * kPointerSize));
        __ push(eax);
        __ mov(Operand(eax), Immediate(slots));
        Label loop;
        __ bind(&loop);
        __ mov(MemOperand(esp, eax, times_4, 0),
               Immediate(kSlotsZapValue));
        __ dec(eax);
        __ j(not_zero, &loop);
        __ pop(eax);
      } else {
        __ sub(Operand(esp), Immediate(slots * kPointerSize));
#ifdef _MSC_VER
        // On windows, you may not access the stack more than one page below
        // the most recently mapped page. To make the allocated area randomly
        // accessible, we write to each page in turn (the value is irrelevant).
        const int kPageSize = 4 * KB;
        for (int offset = slots * kPointerSize - kPageSize;
             offset > 0;
             offset -= kPageSize) {
          __ mov(Operand(esp, offset), eax);
        }
#endif
      }

      if (support_aligned_spilled_doubles_) {
        Comment(";;; Store dynamic frame alignment tag for spilled doubles");
        // Store dynamic frame alignment state in the first local.
        int offset = JavaScriptFrameConstants::kDynamicAlignmentStateOffset;
        if (dynamic_frame_alignment_) {
          __ mov(Operand(ebp, offset), edx);
        } else {
          __ mov(Operand(ebp, offset), Immediate(kNoAlignmentPadding));
        }
      }
    }

    if (info()->saves_caller_doubles() && CpuFeatures::IsSupported(SSE2)) {
      Comment(";;; Save clobbered callee double registers");
      CpuFeatureScope scope(masm(), SSE2);
      int count = 0;
      BitVector* doubles = chunk()->allocated_double_registers();
      BitVector::Iterator save_iterator(doubles);
      while (!save_iterator.Done()) {
        __ movdbl(MemOperand(esp, count * kDoubleSize),
                  XMMRegister::FromAllocationIndex(save_iterator.Current()));
        save_iterator.Advance();
        count++;
      }
    }
  }

  // Possibly allocate a local context.
  int heap_slots = info_->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
  if (heap_slots > 0) {
    Comment(";;; Allocate local context");
    // Argument to NewContext is the function, which is still in edi.
    __ push(edi);
    if (heap_slots <= FastNewContextStub::kMaximumSlots) {
      FastNewContextStub stub(heap_slots);
      __ CallStub(&stub);
    } else {
      __ CallRuntime(Runtime::kNewFunctionContext, 1);
    }
    RecordSafepoint(Safepoint::kNoLazyDeopt);
    // Context is returned in both eax and esi.  It replaces the context
    // passed to us.  It's saved in the stack and kept live in esi.
    __ mov(Operand(ebp, StandardFrameConstants::kContextOffset), esi);

    // Copy parameters into context if necessary.
    int num_parameters = scope()->num_parameters();
    for (int i = 0; i < num_parameters; i++) {
      Variable* var = scope()->parameter(i);
      if (var->IsContextSlot()) {
        int parameter_offset = StandardFrameConstants::kCallerSPOffset +
            (num_parameters - 1 - i) * kPointerSize;
        // Load parameter from stack.
        __ mov(eax, Operand(ebp, parameter_offset));
        // Store it in the context.
        int context_offset = Context::SlotOffset(var->index());
        __ mov(Operand(esi, context_offset), eax);
        // Update the write barrier. This clobbers eax and ebx.
        __ RecordWriteContextSlot(esi,
                                  context_offset,
                                  eax,
                                  ebx,
                                  kDontSaveFPRegs);
      }
    }
    Comment(";;; End allocate local context");
  }

  // Trace the call.
  if (FLAG_trace && info()->IsOptimizing()) {
    // We have not executed any compiled code yet, so esi still holds the
    // incoming context.
    __ CallRuntime(Runtime::kTraceEnter, 0);
  }
  return !is_aborted();
}


bool LCodeGen::GenerateBody() {
  ASSERT(is_generating());
  bool emit_instructions = true;
  for (current_instruction_ = 0;
       !is_aborted() && current_instruction_ < instructions_->length();
       current_instruction_++) {
    LInstruction* instr = instructions_->at(current_instruction_);

    // Don't emit code for basic blocks with a replacement.
    if (instr->IsLabel()) {
      emit_instructions = !LLabel::cast(instr)->HasReplacement();
    }
    if (!emit_instructions) continue;

    if (FLAG_code_comments && instr->HasInterestingComment(this)) {
      Comment(";;; <@%d,#%d> %s",
              current_instruction_,
              instr->hydrogen_value()->id(),
              instr->Mnemonic());
    }

    if (!CpuFeatures::IsSupported(SSE2)) FlushX87StackIfNecessary(instr);

    instr->CompileToNative(this);

    if (!CpuFeatures::IsSupported(SSE2)) {
      ASSERT(!instr->HasDoubleRegisterResult() || x87_stack_depth_ == 1);
      if (FLAG_debug_code && FLAG_enable_slow_asserts) {
        __ VerifyX87StackDepth(x87_stack_depth_);
      }
    }
  }
  EnsureSpaceForLazyDeopt();
  return !is_aborted();
}


bool LCodeGen::GenerateJumpTable() {
  Label needs_frame_not_call;
  Label needs_frame_is_call;
  if (jump_table_.length() > 0) {
    Comment(";;; -------------------- Jump table --------------------");
  }
  for (int i = 0; i < jump_table_.length(); i++) {
    __ bind(&jump_table_[i].label);
    Address entry = jump_table_[i].address;
    Deoptimizer::BailoutType type = jump_table_[i].bailout_type;
    int id = Deoptimizer::GetDeoptimizationId(isolate(), entry, type);
    if (id == Deoptimizer::kNotDeoptimizationEntry) {
      Comment(";;; jump table entry %d.", i);
    } else {
      Comment(";;; jump table entry %d: deoptimization bailout %d.", i, id);
    }
    if (jump_table_[i].needs_frame) {
      __ push(Immediate(ExternalReference::ForDeoptEntry(entry)));
      if (type == Deoptimizer::LAZY) {
        if (needs_frame_is_call.is_bound()) {
          __ jmp(&needs_frame_is_call);
        } else {
          __ bind(&needs_frame_is_call);
          __ push(MemOperand(ebp, StandardFrameConstants::kContextOffset));
          // This variant of deopt can only be used with stubs. Since we don't
          // have a function pointer to install in the stack frame that we're
          // building, install a special marker there instead.
          ASSERT(info()->IsStub());
          __ push(Immediate(Smi::FromInt(StackFrame::STUB)));
          // Push a PC inside the function so that the deopt code can find where
          // the deopt comes from. It doesn't have to be the precise return
          // address of a "calling" LAZY deopt, it only has to be somewhere
          // inside the code body.
          Label push_approx_pc;
          __ call(&push_approx_pc);
          __ bind(&push_approx_pc);
          // Push the continuation which was stashed were the ebp should
          // be. Replace it with the saved ebp.
          __ push(MemOperand(esp, 3 * kPointerSize));
          __ mov(MemOperand(esp, 4 * kPointerSize), ebp);
          __ lea(ebp, MemOperand(esp, 4 * kPointerSize));
          __ ret(0);  // Call the continuation without clobbering registers.
        }
      } else {
        if (needs_frame_not_call.is_bound()) {
          __ jmp(&needs_frame_not_call);
        } else {
          __ bind(&needs_frame_not_call);
          __ push(MemOperand(ebp, StandardFrameConstants::kContextOffset));
          // This variant of deopt can only be used with stubs. Since we don't
          // have a function pointer to install in the stack frame that we're
          // building, install a special marker there instead.
          ASSERT(info()->IsStub());
          __ push(Immediate(Smi::FromInt(StackFrame::STUB)));
          // Push the continuation which was stashed were the ebp should
          // be. Replace it with the saved ebp.
          __ push(MemOperand(esp, 2 * kPointerSize));
          __ mov(MemOperand(esp, 3 * kPointerSize), ebp);
          __ lea(ebp, MemOperand(esp, 3 * kPointerSize));
          __ ret(0);  // Call the continuation without clobbering registers.
        }
      }
    } else {
      if (type == Deoptimizer::LAZY) {
        __ call(entry, RelocInfo::RUNTIME_ENTRY);
      } else {
        __ jmp(entry, RelocInfo::RUNTIME_ENTRY);
      }
    }
  }
  return !is_aborted();
}


bool LCodeGen::GenerateDeferredCode() {
  ASSERT(is_generating());
  if (deferred_.length() > 0) {
    for (int i = 0; !is_aborted() && i < deferred_.length(); i++) {
      LDeferredCode* code = deferred_[i];
      Comment(";;; <@%d,#%d> "
              "-------------------- Deferred %s --------------------",
              code->instruction_index(),
              code->instr()->hydrogen_value()->id(),
              code->instr()->Mnemonic());
      __ bind(code->entry());
      if (NeedsDeferredFrame()) {
        Comment(";;; Build frame");
        ASSERT(!frame_is_built_);
        ASSERT(info()->IsStub());
        frame_is_built_ = true;
        // Build the frame in such a way that esi isn't trashed.
        __ push(ebp);  // Caller's frame pointer.
        __ push(Operand(ebp, StandardFrameConstants::kContextOffset));
        __ push(Immediate(Smi::FromInt(StackFrame::STUB)));
        __ lea(ebp, Operand(esp, 2 * kPointerSize));
        Comment(";;; Deferred code");
      }
      code->Generate();
      if (NeedsDeferredFrame()) {
        Comment(";;; Destroy frame");
        ASSERT(frame_is_built_);
        frame_is_built_ = false;
        __ mov(esp, ebp);
        __ pop(ebp);
      }
      __ jmp(code->exit());
    }
  }

  // Deferred code is the last part of the instruction sequence. Mark
  // the generated code as done unless we bailed out.
  if (!is_aborted()) status_ = DONE;
  return !is_aborted();
}


bool LCodeGen::GenerateSafepointTable() {
  ASSERT(is_done());
  if (!info()->IsStub()) {
    // For lazy deoptimization we need space to patch a call after every call.
    // Ensure there is always space for such patching, even if the code ends
    // in a call.
    int target_offset = masm()->pc_offset() + Deoptimizer::patch_size();
    while (masm()->pc_offset() < target_offset) {
      masm()->nop();
    }
  }
  safepoints_.Emit(masm(), GetStackSlotCount());
  return !is_aborted();
}


Register LCodeGen::ToRegister(int index) const {
  return Register::FromAllocationIndex(index);
}


XMMRegister LCodeGen::ToDoubleRegister(int index) const {
  return XMMRegister::FromAllocationIndex(index);
}


bool LCodeGen::IsX87TopOfStack(LOperand* op) const {
  return op->IsDoubleRegister();
}


void LCodeGen::ReadX87Operand(Operand dst) {
  ASSERT(x87_stack_depth_ == 1);
  __ fst_d(dst);
}


void LCodeGen::PushX87DoubleOperand(Operand src) {
  ASSERT(x87_stack_depth_ == 0);
  x87_stack_depth_++;
  __ fld_d(src);
}


void LCodeGen::PushX87FloatOperand(Operand src) {
  ASSERT(x87_stack_depth_ == 0);
  x87_stack_depth_++;
  __ fld_s(src);
}


void LCodeGen::PopX87() {
  ASSERT(x87_stack_depth_ == 1);
  x87_stack_depth_--;
  __ fstp(0);
}


void LCodeGen::CurrentInstructionReturnsX87Result() {
  ASSERT(x87_stack_depth_ <= 1);
  if (x87_stack_depth_ == 0) {
    x87_stack_depth_ = 1;
  }
}


void LCodeGen::FlushX87StackIfNecessary(LInstruction* instr) {
  if (x87_stack_depth_ > 0) {
    if ((instr->ClobbersDoubleRegisters() ||
         instr->HasDoubleRegisterResult()) &&
        !instr->HasDoubleRegisterInput()) {
      PopX87();
    }
  }
}


Register LCodeGen::ToRegister(LOperand* op) const {
  ASSERT(op->IsRegister());
  return ToRegister(op->index());
}


XMMRegister LCodeGen::ToDoubleRegister(LOperand* op) const {
  ASSERT(op->IsDoubleRegister());
  return ToDoubleRegister(op->index());
}


int LCodeGen::ToInteger32(LConstantOperand* op) const {
  HConstant* constant = chunk_->LookupConstant(op);
  return constant->Integer32Value();
}


Handle<Object> LCodeGen::ToHandle(LConstantOperand* op) const {
  HConstant* constant = chunk_->LookupConstant(op);
  ASSERT(chunk_->LookupLiteralRepresentation(op).IsSmiOrTagged());
  return constant->handle();
}


double LCodeGen::ToDouble(LConstantOperand* op) const {
  HConstant* constant = chunk_->LookupConstant(op);
  ASSERT(constant->HasDoubleValue());
  return constant->DoubleValue();
}


bool LCodeGen::IsInteger32(LConstantOperand* op) const {
  return chunk_->LookupLiteralRepresentation(op).IsSmiOrInteger32();
}


bool LCodeGen::IsSmi(LConstantOperand* op) const {
  return chunk_->LookupLiteralRepresentation(op).IsSmi();
}


Operand LCodeGen::ToOperand(LOperand* op) const {
  if (op->IsRegister()) return Operand(ToRegister(op));
  if (op->IsDoubleRegister()) return Operand(ToDoubleRegister(op));
  ASSERT(op->IsStackSlot() || op->IsDoubleStackSlot());
  return Operand(ebp, StackSlotOffset(op->index()));
}


Operand LCodeGen::HighOperand(LOperand* op) {
  ASSERT(op->IsDoubleStackSlot());
  return Operand(ebp, StackSlotOffset(op->index()) + kPointerSize);
}


void LCodeGen::WriteTranslation(LEnvironment* environment,
                                Translation* translation,
                                int* pushed_arguments_index,
                                int* pushed_arguments_count) {
  if (environment == NULL) return;

  // The translation includes one command per value in the environment.
  int translation_size = environment->values()->length();
  // The output frame height does not include the parameters.
  int height = translation_size - environment->parameter_count();

  // Function parameters are arguments to the outermost environment. The
  // arguments index points to the first element of a sequence of tagged
  // values on the stack that represent the arguments. This needs to be
  // kept in sync with the LArgumentsElements implementation.
  *pushed_arguments_index = -environment->parameter_count();
  *pushed_arguments_count = environment->parameter_count();

  WriteTranslation(environment->outer(),
                   translation,
                   pushed_arguments_index,
                   pushed_arguments_count);
  bool has_closure_id = !info()->closure().is_null() &&
      !info()->closure().is_identical_to(environment->closure());
  int closure_id = has_closure_id
      ? DefineDeoptimizationLiteral(environment->closure())
      : Translation::kSelfLiteralId;
  switch (environment->frame_type()) {
    case JS_FUNCTION:
      translation->BeginJSFrame(environment->ast_id(), closure_id, height);
      break;
    case JS_CONSTRUCT:
      translation->BeginConstructStubFrame(closure_id, translation_size);
      break;
    case JS_GETTER:
      ASSERT(translation_size == 1);
      ASSERT(height == 0);
      translation->BeginGetterStubFrame(closure_id);
      break;
    case JS_SETTER:
      ASSERT(translation_size == 2);
      ASSERT(height == 0);
      translation->BeginSetterStubFrame(closure_id);
      break;
    case ARGUMENTS_ADAPTOR:
      translation->BeginArgumentsAdaptorFrame(closure_id, translation_size);
      break;
    case STUB:
      translation->BeginCompiledStubFrame();
      break;
    default:
      UNREACHABLE();
  }

  // Inlined frames which push their arguments cause the index to be
  // bumped and another stack area to be used for materialization,
  // otherwise actual argument values are unknown for inlined frames.
  bool arguments_known = true;
  int arguments_index = *pushed_arguments_index;
  int arguments_count = *pushed_arguments_count;
  if (environment->entry() != NULL) {
    arguments_known = environment->entry()->arguments_pushed();
    arguments_index = arguments_index < 0
        ? GetStackSlotCount() : arguments_index + arguments_count;
    arguments_count = environment->entry()->arguments_count() + 1;
    if (environment->entry()->arguments_pushed()) {
      *pushed_arguments_index = arguments_index;
      *pushed_arguments_count = arguments_count;
    }
  }

  for (int i = 0; i < translation_size; ++i) {
    LOperand* value = environment->values()->at(i);
    // spilled_registers_ and spilled_double_registers_ are either
    // both NULL or both set.
    if (environment->spilled_registers() != NULL && value != NULL) {
      if (value->IsRegister() &&
          environment->spilled_registers()[value->index()] != NULL) {
        translation->MarkDuplicate();
        AddToTranslation(translation,
                         environment->spilled_registers()[value->index()],
                         environment->HasTaggedValueAt(i),
                         environment->HasUint32ValueAt(i),
                         arguments_known,
                         arguments_index,
                         arguments_count);
      } else if (
          value->IsDoubleRegister() &&
          environment->spilled_double_registers()[value->index()] != NULL) {
        translation->MarkDuplicate();
        AddToTranslation(
            translation,
            environment->spilled_double_registers()[value->index()],
            false,
            false,
            arguments_known,
            arguments_index,
            arguments_count);
      }
    }

    AddToTranslation(translation,
                     value,
                     environment->HasTaggedValueAt(i),
                     environment->HasUint32ValueAt(i),
                     arguments_known,
                     arguments_index,
                     arguments_count);
  }
}


void LCodeGen::AddToTranslation(Translation* translation,
                                LOperand* op,
                                bool is_tagged,
                                bool is_uint32,
                                bool arguments_known,
                                int arguments_index,
                                int arguments_count) {
  if (op == NULL) {
    // TODO(twuerthinger): Introduce marker operands to indicate that this value
    // is not present and must be reconstructed from the deoptimizer. Currently
    // this is only used for the arguments object.
    translation->StoreArgumentsObject(
        arguments_known, arguments_index, arguments_count);
  } else if (op->IsStackSlot()) {
    if (is_tagged) {
      translation->StoreStackSlot(op->index());
    } else if (is_uint32) {
      translation->StoreUint32StackSlot(op->index());
    } else {
      translation->StoreInt32StackSlot(op->index());
    }
  } else if (op->IsDoubleStackSlot()) {
    translation->StoreDoubleStackSlot(op->index());
  } else if (op->IsArgument()) {
    ASSERT(is_tagged);
    int src_index = GetStackSlotCount() + op->index();
    translation->StoreStackSlot(src_index);
  } else if (op->IsRegister()) {
    Register reg = ToRegister(op);
    if (is_tagged) {
      translation->StoreRegister(reg);
    } else if (is_uint32) {
      translation->StoreUint32Register(reg);
    } else {
      translation->StoreInt32Register(reg);
    }
  } else if (op->IsDoubleRegister()) {
    XMMRegister reg = ToDoubleRegister(op);
    translation->StoreDoubleRegister(reg);
  } else if (op->IsConstantOperand()) {
    HConstant* constant = chunk()->LookupConstant(LConstantOperand::cast(op));
    int src_index = DefineDeoptimizationLiteral(constant->handle());
    translation->StoreLiteral(src_index);
  } else {
    UNREACHABLE();
  }
}


void LCodeGen::CallCodeGeneric(Handle<Code> code,
                               RelocInfo::Mode mode,
                               LInstruction* instr,
                               SafepointMode safepoint_mode) {
  ASSERT(instr != NULL);
  LPointerMap* pointers = instr->pointer_map();
  RecordPosition(pointers->position());
  __ call(code, mode);
  RecordSafepointWithLazyDeopt(instr, safepoint_mode);

  // Signal that we don't inline smi code before these stubs in the
  // optimizing code generator.
  if (code->kind() == Code::BINARY_OP_IC ||
      code->kind() == Code::COMPARE_IC) {
    __ nop();
  }
}


void LCodeGen::CallCode(Handle<Code> code,
                        RelocInfo::Mode mode,
                        LInstruction* instr) {
  CallCodeGeneric(code, mode, instr, RECORD_SIMPLE_SAFEPOINT);
}


void LCodeGen::CallRuntime(const Runtime::Function* fun,
                           int argc,
                           LInstruction* instr) {
  ASSERT(instr != NULL);
  ASSERT(instr->HasPointerMap());
  LPointerMap* pointers = instr->pointer_map();
  RecordPosition(pointers->position());

  __ CallRuntime(fun, argc);

  RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);

  ASSERT(info()->is_calling());
}


void LCodeGen::LoadContextFromDeferred(LOperand* context) {
  if (context->IsRegister()) {
    if (!ToRegister(context).is(esi)) {
      __ mov(esi, ToRegister(context));
    }
  } else if (context->IsStackSlot()) {
    __ mov(esi, ToOperand(context));
  } else if (context->IsConstantOperand()) {
    HConstant* constant =
        chunk_->LookupConstant(LConstantOperand::cast(context));
    __ LoadHeapObject(esi, Handle<Context>::cast(constant->handle()));
  } else {
    UNREACHABLE();
  }
}

void LCodeGen::CallRuntimeFromDeferred(Runtime::FunctionId id,
                                       int argc,
                                       LInstruction* instr,
                                       LOperand* context) {
  LoadContextFromDeferred(context);

  __ CallRuntimeSaveDoubles(id);
  RecordSafepointWithRegisters(
      instr->pointer_map(), argc, Safepoint::kNoLazyDeopt);

  ASSERT(info()->is_calling());
}


void LCodeGen::RegisterEnvironmentForDeoptimization(
    LEnvironment* environment, Safepoint::DeoptMode mode) {
  if (!environment->HasBeenRegistered()) {
    // Physical stack frame layout:
    // -x ............. -4  0 ..................................... y
    // [incoming arguments] [spill slots] [pushed outgoing arguments]

    // Layout of the environment:
    // 0 ..................................................... size-1
    // [parameters] [locals] [expression stack including arguments]

    // Layout of the translation:
    // 0 ........................................................ size - 1 + 4
    // [expression stack including arguments] [locals] [4 words] [parameters]
    // |>------------  translation_size ------------<|

    int frame_count = 0;
    int jsframe_count = 0;
    int args_index = 0;
    int args_count = 0;
    for (LEnvironment* e = environment; e != NULL; e = e->outer()) {
      ++frame_count;
      if (e->frame_type() == JS_FUNCTION) {
        ++jsframe_count;
      }
    }
    Translation translation(&translations_, frame_count, jsframe_count, zone());
    WriteTranslation(environment, &translation, &args_index, &args_count);
    int deoptimization_index = deoptimizations_.length();
    int pc_offset = masm()->pc_offset();
    environment->Register(deoptimization_index,
                          translation.index(),
                          (mode == Safepoint::kLazyDeopt) ? pc_offset : -1);
    deoptimizations_.Add(environment, zone());
  }
}


void LCodeGen::DeoptimizeIf(Condition cc,
                            LEnvironment* environment,
                            Deoptimizer::BailoutType bailout_type) {
  RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
  ASSERT(environment->HasBeenRegistered());
  // It's an error to deoptimize with the x87 fp stack in use.
  ASSERT(x87_stack_depth_ == 0);
  int id = environment->deoptimization_index();
  ASSERT(info()->IsOptimizing() || info()->IsStub());
  Address entry =
      Deoptimizer::GetDeoptimizationEntry(isolate(), id, bailout_type);
  if (entry == NULL) {
    Abort("bailout was not prepared");
    return;
  }

  if (FLAG_deopt_every_n_times != 0 && !info()->IsStub()) {
    Handle<SharedFunctionInfo> shared(info()->shared_info());
    Label no_deopt;
    __ pushfd();
    __ push(eax);
    __ push(ebx);
    __ mov(ebx, shared);
    __ mov(eax,
           FieldOperand(ebx, SharedFunctionInfo::kStressDeoptCounterOffset));
    __ sub(Operand(eax), Immediate(Smi::FromInt(1)));
    __ j(not_zero, &no_deopt, Label::kNear);
    if (FLAG_trap_on_deopt) __ int3();
    __ mov(eax, Immediate(Smi::FromInt(FLAG_deopt_every_n_times)));
    __ mov(FieldOperand(ebx, SharedFunctionInfo::kStressDeoptCounterOffset),
           eax);
    __ pop(ebx);
    __ pop(eax);
    __ popfd();
    __ jmp(entry, RelocInfo::RUNTIME_ENTRY);

    __ bind(&no_deopt);
    __ mov(FieldOperand(ebx, SharedFunctionInfo::kStressDeoptCounterOffset),
           eax);
    __ pop(ebx);
    __ pop(eax);
    __ popfd();
  }

  if (FLAG_trap_on_deopt) {
    Label done;
    if (cc != no_condition) {
      __ j(NegateCondition(cc), &done, Label::kNear);
    }
    __ int3();
    __ bind(&done);
  }

  ASSERT(info()->IsStub() || frame_is_built_);
  if (cc == no_condition && frame_is_built_) {
    if (bailout_type == Deoptimizer::LAZY) {
      __ call(entry, RelocInfo::RUNTIME_ENTRY);
    } else {
      __ jmp(entry, RelocInfo::RUNTIME_ENTRY);
    }
  } else {
    // We often have several deopts to the same entry, reuse the last
    // jump entry if this is the case.
    if (jump_table_.is_empty() ||
        jump_table_.last().address != entry ||
        jump_table_.last().needs_frame != !frame_is_built_ ||
        jump_table_.last().bailout_type != bailout_type) {
      Deoptimizer::JumpTableEntry table_entry(entry,
                                              bailout_type,
                                              !frame_is_built_);
      jump_table_.Add(table_entry, zone());
    }
    if (cc == no_condition) {
      __ jmp(&jump_table_.last().label);
    } else {
      __ j(cc, &jump_table_.last().label);
    }
  }
}


void LCodeGen::DeoptimizeIf(Condition cc,
                            LEnvironment* environment) {
  Deoptimizer::BailoutType bailout_type = info()->IsStub()
      ? Deoptimizer::LAZY
      : Deoptimizer::EAGER;
  DeoptimizeIf(cc, environment, bailout_type);
}


void LCodeGen::SoftDeoptimize(LEnvironment* environment) {
  ASSERT(!info()->IsStub());
  DeoptimizeIf(no_condition, environment, Deoptimizer::SOFT);
}


void LCodeGen::RegisterDependentCodeForEmbeddedMaps(Handle<Code> code) {
  ZoneList<Handle<Map> > maps(1, zone());
  int mode_mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT);
  for (RelocIterator it(*code, mode_mask); !it.done(); it.next()) {
    RelocInfo::Mode mode = it.rinfo()->rmode();
    if (mode == RelocInfo::EMBEDDED_OBJECT &&
        it.rinfo()->target_object()->IsMap()) {
      Handle<Map> map(Map::cast(it.rinfo()->target_object()));
      if (map->CanTransition()) {
        maps.Add(map, zone());
      }
    }
  }
#ifdef VERIFY_HEAP
  // This disables verification of weak embedded maps after full GC.
  // AddDependentCode can cause a GC, which would observe the state where
  // this code is not yet in the depended code lists of the embedded maps.
  NoWeakEmbeddedMapsVerificationScope disable_verification_of_embedded_maps;
#endif
  for (int i = 0; i < maps.length(); i++) {
    maps.at(i)->AddDependentCode(DependentCode::kWeaklyEmbeddedGroup, code);
  }
}


void LCodeGen::PopulateDeoptimizationData(Handle<Code> code) {
  int length = deoptimizations_.length();
  if (length == 0) return;
  Handle<DeoptimizationInputData> data =
      factory()->NewDeoptimizationInputData(length, TENURED);

  Handle<ByteArray> translations =
      translations_.CreateByteArray(isolate()->factory());
  data->SetTranslationByteArray(*translations);
  data->SetInlinedFunctionCount(Smi::FromInt(inlined_function_count_));

  Handle<FixedArray> literals =
      factory()->NewFixedArray(deoptimization_literals_.length(), TENURED);
  { AllowDeferredHandleDereference copy_handles;
    for (int i = 0; i < deoptimization_literals_.length(); i++) {
      literals->set(i, *deoptimization_literals_[i]);
    }
    data->SetLiteralArray(*literals);
  }

  data->SetOsrAstId(Smi::FromInt(info_->osr_ast_id().ToInt()));
  data->SetOsrPcOffset(Smi::FromInt(osr_pc_offset_));

  // Populate the deoptimization entries.
  for (int i = 0; i < length; i++) {
    LEnvironment* env = deoptimizations_[i];
    data->SetAstId(i, env->ast_id());
    data->SetTranslationIndex(i, Smi::FromInt(env->translation_index()));
    data->SetArgumentsStackHeight(i,
                                  Smi::FromInt(env->arguments_stack_height()));
    data->SetPc(i, Smi::FromInt(env->pc_offset()));
  }
  code->set_deoptimization_data(*data);
}


int LCodeGen::DefineDeoptimizationLiteral(Handle<Object> literal) {
  int result = deoptimization_literals_.length();
  for (int i = 0; i < deoptimization_literals_.length(); ++i) {
    if (deoptimization_literals_[i].is_identical_to(literal)) return i;
  }
  deoptimization_literals_.Add(literal, zone());
  return result;
}


void LCodeGen::PopulateDeoptimizationLiteralsWithInlinedFunctions() {
  ASSERT(deoptimization_literals_.length() == 0);

  const ZoneList<Handle<JSFunction> >* inlined_closures =
      chunk()->inlined_closures();

  for (int i = 0, length = inlined_closures->length();
       i < length;
       i++) {
    DefineDeoptimizationLiteral(inlined_closures->at(i));
  }

  inlined_function_count_ = deoptimization_literals_.length();
}


void LCodeGen::RecordSafepointWithLazyDeopt(
    LInstruction* instr, SafepointMode safepoint_mode) {
  if (safepoint_mode == RECORD_SIMPLE_SAFEPOINT) {
    RecordSafepoint(instr->pointer_map(), Safepoint::kLazyDeopt);
  } else {
    ASSERT(safepoint_mode == RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
    RecordSafepointWithRegisters(
        instr->pointer_map(), 0, Safepoint::kLazyDeopt);
  }
}


void LCodeGen::RecordSafepoint(
    LPointerMap* pointers,
    Safepoint::Kind kind,
    int arguments,
    Safepoint::DeoptMode deopt_mode) {
  ASSERT(kind == expected_safepoint_kind_);
  const ZoneList<LOperand*>* operands = pointers->GetNormalizedOperands();
  Safepoint safepoint =
      safepoints_.DefineSafepoint(masm(), kind, arguments, deopt_mode);
  for (int i = 0; i < operands->length(); i++) {
    LOperand* pointer = operands->at(i);
    if (pointer->IsStackSlot()) {
      safepoint.DefinePointerSlot(pointer->index(), zone());
    } else if (pointer->IsRegister() && (kind & Safepoint::kWithRegisters)) {
      safepoint.DefinePointerRegister(ToRegister(pointer), zone());
    }
  }
}


void LCodeGen::RecordSafepoint(LPointerMap* pointers,
                               Safepoint::DeoptMode mode) {
  RecordSafepoint(pointers, Safepoint::kSimple, 0, mode);
}


void LCodeGen::RecordSafepoint(Safepoint::DeoptMode mode) {
  LPointerMap empty_pointers(RelocInfo::kNoPosition, zone());
  RecordSafepoint(&empty_pointers, mode);
}


void LCodeGen::RecordSafepointWithRegisters(LPointerMap* pointers,
                                            int arguments,
                                            Safepoint::DeoptMode mode) {
  RecordSafepoint(pointers, Safepoint::kWithRegisters, arguments, mode);
}


void LCodeGen::RecordPosition(int position) {
  if (position == RelocInfo::kNoPosition) return;
  masm()->positions_recorder()->RecordPosition(position);
}


static const char* LabelType(LLabel* label) {
  if (label->is_loop_header()) return " (loop header)";
  if (label->is_osr_entry()) return " (OSR entry)";
  return "";
}


void LCodeGen::DoLabel(LLabel* label) {
  Comment(";;; <@%d,#%d> -------------------- B%d%s --------------------",
          current_instruction_,
          label->hydrogen_value()->id(),
          label->block_id(),
          LabelType(label));
  __ bind(label->label());
  current_block_ = label->block_id();
  DoGap(label);
}


void LCodeGen::DoParallelMove(LParallelMove* move) {
  resolver_.Resolve(move);
}


void LCodeGen::DoGap(LGap* gap) {
  for (int i = LGap::FIRST_INNER_POSITION;
       i <= LGap::LAST_INNER_POSITION;
       i++) {
    LGap::InnerPosition inner_pos = static_cast<LGap::InnerPosition>(i);
    LParallelMove* move = gap->GetParallelMove(inner_pos);
    if (move != NULL) DoParallelMove(move);
  }
}


void LCodeGen::DoInstructionGap(LInstructionGap* instr) {
  DoGap(instr);
}


void LCodeGen::DoParameter(LParameter* instr) {
  // Nothing to do.
}


void LCodeGen::DoCallStub(LCallStub* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  ASSERT(ToRegister(instr->result()).is(eax));
  switch (instr->hydrogen()->major_key()) {
    case CodeStub::RegExpConstructResult: {
      RegExpConstructResultStub stub;
      CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
      break;
    }
    case CodeStub::RegExpExec: {
      RegExpExecStub stub;
      CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
      break;
    }
    case CodeStub::SubString: {
      SubStringStub stub;
      CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
      break;
    }
    case CodeStub::NumberToString: {
      NumberToStringStub stub;
      CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
      break;
    }
    case CodeStub::StringAdd: {
      StringAddStub stub(NO_STRING_ADD_FLAGS);
      CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
      break;
    }
    case CodeStub::StringCompare: {
      StringCompareStub stub;
      CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
      break;
    }
    case CodeStub::TranscendentalCache: {
      TranscendentalCacheStub stub(instr->transcendental_type(),
                                   TranscendentalCacheStub::TAGGED);
      CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
      break;
    }
    default:
      UNREACHABLE();
  }
}


void LCodeGen::DoUnknownOSRValue(LUnknownOSRValue* instr) {
  // Nothing to do.
}


void LCodeGen::DoModI(LModI* instr) {
  if (instr->hydrogen()->HasPowerOf2Divisor()) {
    Register dividend = ToRegister(instr->left());

    int32_t divisor =
        HConstant::cast(instr->hydrogen()->right())->Integer32Value();

    if (divisor < 0) divisor = -divisor;

    Label positive_dividend, done;
    __ test(dividend, Operand(dividend));
    __ j(not_sign, &positive_dividend, Label::kNear);
    __ neg(dividend);
    __ and_(dividend, divisor - 1);
    __ neg(dividend);
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      __ j(not_zero, &done, Label::kNear);
      DeoptimizeIf(no_condition, instr->environment());
    } else {
      __ jmp(&done, Label::kNear);
    }
    __ bind(&positive_dividend);
    __ and_(dividend, divisor - 1);
    __ bind(&done);
  } else {
    Label done, remainder_eq_dividend, slow, both_positive;
    Register left_reg = ToRegister(instr->left());
    Register right_reg = ToRegister(instr->right());
    Register result_reg = ToRegister(instr->result());

    ASSERT(left_reg.is(eax));
    ASSERT(result_reg.is(edx));
    ASSERT(!right_reg.is(eax));
    ASSERT(!right_reg.is(edx));

    // Check for x % 0.
    if (instr->hydrogen()->CheckFlag(HValue::kCanBeDivByZero)) {
      __ test(right_reg, Operand(right_reg));
      DeoptimizeIf(zero, instr->environment());
    }

    __ test(left_reg, Operand(left_reg));
    __ j(zero, &remainder_eq_dividend, Label::kNear);
    __ j(sign, &slow, Label::kNear);

    __ test(right_reg, Operand(right_reg));
    __ j(not_sign, &both_positive, Label::kNear);
    // The sign of the divisor doesn't matter.
    __ neg(right_reg);

    __ bind(&both_positive);
    // If the dividend is smaller than the nonnegative
    // divisor, the dividend is the result.
    __ cmp(left_reg, Operand(right_reg));
    __ j(less, &remainder_eq_dividend, Label::kNear);

    // Check if the divisor is a PowerOfTwo integer.
    Register scratch = ToRegister(instr->temp());
    __ mov(scratch, right_reg);
    __ sub(Operand(scratch), Immediate(1));
    __ test(scratch, Operand(right_reg));
    __ j(not_zero, &slow, Label::kNear);
    __ and_(left_reg, Operand(scratch));
    __ jmp(&remainder_eq_dividend, Label::kNear);

    // Slow case, using idiv instruction.
    __ bind(&slow);

    // Check for (kMinInt % -1).
    if (instr->hydrogen()->CheckFlag(HValue::kCanOverflow)) {
      Label left_not_min_int;
      __ cmp(left_reg, kMinInt);
      __ j(not_zero, &left_not_min_int, Label::kNear);
      __ cmp(right_reg, -1);
      DeoptimizeIf(zero, instr->environment());
      __ bind(&left_not_min_int);
    }

    // Sign extend to edx.
    __ cdq();

    // Check for (0 % -x) that will produce negative zero.
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      Label positive_left;
      Label done;
      __ test(left_reg, Operand(left_reg));
      __ j(not_sign, &positive_left, Label::kNear);
      __ idiv(right_reg);

      // Test the remainder for 0, because then the result would be -0.
      __ test(result_reg, Operand(result_reg));
      __ j(not_zero, &done, Label::kNear);

      DeoptimizeIf(no_condition, instr->environment());
      __ bind(&positive_left);
      __ idiv(right_reg);
      __ bind(&done);
    } else {
      __ idiv(right_reg);
    }
    __ jmp(&done, Label::kNear);

    __ bind(&remainder_eq_dividend);
    __ mov(result_reg, left_reg);

    __ bind(&done);
  }
}


void LCodeGen::DoDivI(LDivI* instr) {
  if (!instr->is_flooring() && instr->hydrogen()->HasPowerOf2Divisor()) {
    Register dividend = ToRegister(instr->left());
    int32_t divisor =
        HConstant::cast(instr->hydrogen()->right())->Integer32Value();
    int32_t test_value = 0;
    int32_t power = 0;

    if (divisor > 0) {
      test_value = divisor - 1;
      power = WhichPowerOf2(divisor);
    } else {
      // Check for (0 / -x) that will produce negative zero.
      if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
        __ test(dividend, Operand(dividend));
        DeoptimizeIf(zero, instr->environment());
      }
      // Check for (kMinInt / -1).
      if (divisor == -1 && instr->hydrogen()->CheckFlag(HValue::kCanOverflow)) {
        __ cmp(dividend, kMinInt);
        DeoptimizeIf(zero, instr->environment());
      }
      test_value = - divisor - 1;
      power = WhichPowerOf2(-divisor);
    }

    if (test_value != 0) {
      // Deoptimize if remainder is not 0.
      __ test(dividend, Immediate(test_value));
      DeoptimizeIf(not_zero, instr->environment());
      __ sar(dividend, power);
    }

    if (divisor < 0) __ neg(dividend);

    return;
  }

  LOperand* right = instr->right();
  ASSERT(ToRegister(instr->result()).is(eax));
  ASSERT(ToRegister(instr->left()).is(eax));
  ASSERT(!ToRegister(instr->right()).is(eax));
  ASSERT(!ToRegister(instr->right()).is(edx));

  Register left_reg = eax;

  // Check for x / 0.
  Register right_reg = ToRegister(right);
  if (instr->hydrogen_value()->CheckFlag(HValue::kCanBeDivByZero)) {
    __ test(right_reg, ToOperand(right));
    DeoptimizeIf(zero, instr->environment());
  }

  // Check for (0 / -x) that will produce negative zero.
  if (instr->hydrogen_value()->CheckFlag(HValue::kBailoutOnMinusZero)) {
    Label left_not_zero;
    __ test(left_reg, Operand(left_reg));
    __ j(not_zero, &left_not_zero, Label::kNear);
    __ test(right_reg, ToOperand(right));
    DeoptimizeIf(sign, instr->environment());
    __ bind(&left_not_zero);
  }

  // Check for (kMinInt / -1).
  if (instr->hydrogen_value()->CheckFlag(HValue::kCanOverflow)) {
    Label left_not_min_int;
    __ cmp(left_reg, kMinInt);
    __ j(not_zero, &left_not_min_int, Label::kNear);
    __ cmp(right_reg, -1);
    DeoptimizeIf(zero, instr->environment());
    __ bind(&left_not_min_int);
  }

  // Sign extend to edx.
  __ cdq();
  __ idiv(right_reg);

  if (!instr->is_flooring()) {
    // Deoptimize if remainder is not 0.
    __ test(edx, Operand(edx));
    DeoptimizeIf(not_zero, instr->environment());
  } else {
    Label done;
    __ test(edx, edx);
    __ j(zero, &done, Label::kNear);
    __ xor_(edx, right_reg);
    __ sar(edx, 31);
    __ add(eax, edx);
    __ bind(&done);
  }
}


void LCodeGen::DoMathFloorOfDiv(LMathFloorOfDiv* instr) {
  ASSERT(instr->right()->IsConstantOperand());

  Register dividend = ToRegister(instr->left());
  int32_t divisor = ToInteger32(LConstantOperand::cast(instr->right()));
  Register result = ToRegister(instr->result());

  switch (divisor) {
  case 0:
    DeoptimizeIf(no_condition, instr->environment());
    return;

  case 1:
    __ Move(result, dividend);
    return;

  case -1:
    __ Move(result, dividend);
    __ neg(result);
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      DeoptimizeIf(zero, instr->environment());
    }
    if (instr->hydrogen()->CheckFlag(HValue::kCanOverflow)) {
      DeoptimizeIf(overflow, instr->environment());
    }
    return;
  }

  uint32_t divisor_abs = abs(divisor);
  if (IsPowerOf2(divisor_abs)) {
    int32_t power = WhichPowerOf2(divisor_abs);
    if (divisor < 0) {
      // Input[dividend] is clobbered.
      // The sequence is tedious because neg(dividend) might overflow.
      __ mov(result, dividend);
      __ sar(dividend, 31);
      __ neg(result);
      if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
        DeoptimizeIf(zero, instr->environment());
      }
      __ shl(dividend, 32 - power);
      __ sar(result, power);
      __ not_(dividend);
      // Clear result.sign if dividend.sign is set.
      __ and_(result, dividend);
    } else {
      __ Move(result, dividend);
      __ sar(result, power);
    }
  } else {
    ASSERT(ToRegister(instr->left()).is(eax));
    ASSERT(ToRegister(instr->result()).is(edx));
    Register scratch = ToRegister(instr->temp());

    // Find b which: 2^b < divisor_abs < 2^(b+1).
    unsigned b = 31 - CompilerIntrinsics::CountLeadingZeros(divisor_abs);
    unsigned shift = 32 + b;  // Precision +1bit (effectively).
    double multiplier_f =
        static_cast<double>(static_cast<uint64_t>(1) << shift) / divisor_abs;
    int64_t multiplier;
    if (multiplier_f - floor(multiplier_f) < 0.5) {
        multiplier = static_cast<int64_t>(floor(multiplier_f));
    } else {
        multiplier = static_cast<int64_t>(floor(multiplier_f)) + 1;
    }
    // The multiplier is a uint32.
    ASSERT(multiplier > 0 &&
           multiplier < (static_cast<int64_t>(1) << 32));
    __ mov(scratch, dividend);
    if (divisor < 0 &&
        instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      __ test(dividend, dividend);
      DeoptimizeIf(zero, instr->environment());
    }
    __ mov(edx, static_cast<int32_t>(multiplier));
    __ imul(edx);
    if (static_cast<int32_t>(multiplier) < 0) {
      __ add(edx, scratch);
    }
    Register reg_lo = eax;
    Register reg_byte_scratch = scratch;
    if (!reg_byte_scratch.is_byte_register()) {
        __ xchg(reg_lo, reg_byte_scratch);
        reg_lo = scratch;
        reg_byte_scratch = eax;
    }
    if (divisor < 0) {
      __ xor_(reg_byte_scratch, reg_byte_scratch);
      __ cmp(reg_lo, 0x40000000);
      __ setcc(above, reg_byte_scratch);
      __ neg(edx);
      __ sub(edx, reg_byte_scratch);
    } else {
      __ xor_(reg_byte_scratch, reg_byte_scratch);
      __ cmp(reg_lo, 0xC0000000);
      __ setcc(above_equal, reg_byte_scratch);
      __ add(edx, reg_byte_scratch);
    }
    __ sar(edx, shift - 32);
  }
}


void LCodeGen::DoMulI(LMulI* instr) {
  Register left = ToRegister(instr->left());
  LOperand* right = instr->right();

  if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
    __ mov(ToRegister(instr->temp()), left);
  }

  if (right->IsConstantOperand()) {
    // Try strength reductions on the multiplication.
    // All replacement instructions are at most as long as the imul
    // and have better latency.
    int constant = ToInteger32(LConstantOperand::cast(right));
    if (constant == -1) {
      __ neg(left);
    } else if (constant == 0) {
      __ xor_(left, Operand(left));
    } else if (constant == 2) {
      __ add(left, Operand(left));
    } else if (!instr->hydrogen()->CheckFlag(HValue::kCanOverflow)) {
      // If we know that the multiplication can't overflow, it's safe to
      // use instructions that don't set the overflow flag for the
      // multiplication.
      switch (constant) {
        case 1:
          // Do nothing.
          break;
        case 3:
          __ lea(left, Operand(left, left, times_2, 0));
          break;
        case 4:
          __ shl(left, 2);
          break;
        case 5:
          __ lea(left, Operand(left, left, times_4, 0));
          break;
        case 8:
          __ shl(left, 3);
          break;
        case 9:
          __ lea(left, Operand(left, left, times_8, 0));
          break;
       case 16:
         __ shl(left, 4);
         break;
        default:
          __ imul(left, left, constant);
          break;
      }
    } else {
      __ imul(left, left, constant);
    }
  } else {
    __ imul(left, ToOperand(right));
  }

  if (instr->hydrogen()->CheckFlag(HValue::kCanOverflow)) {
    DeoptimizeIf(overflow, instr->environment());
  }

  if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
    // Bail out if the result is supposed to be negative zero.
    Label done;
    __ test(left, Operand(left));
    __ j(not_zero, &done, Label::kNear);
    if (right->IsConstantOperand()) {
      if (ToInteger32(LConstantOperand::cast(right)) < 0) {
        DeoptimizeIf(no_condition, instr->environment());
      } else if (ToInteger32(LConstantOperand::cast(right)) == 0) {
        __ cmp(ToRegister(instr->temp()), Immediate(0));
        DeoptimizeIf(less, instr->environment());
      }
    } else {
      // Test the non-zero operand for negative sign.
      __ or_(ToRegister(instr->temp()), ToOperand(right));
      DeoptimizeIf(sign, instr->environment());
    }
    __ bind(&done);
  }
}


void LCodeGen::DoBitI(LBitI* instr) {
  LOperand* left = instr->left();
  LOperand* right = instr->right();
  ASSERT(left->Equals(instr->result()));
  ASSERT(left->IsRegister());

  if (right->IsConstantOperand()) {
    int right_operand = ToInteger32(LConstantOperand::cast(right));
    switch (instr->op()) {
      case Token::BIT_AND:
        __ and_(ToRegister(left), right_operand);
        break;
      case Token::BIT_OR:
        __ or_(ToRegister(left), right_operand);
        break;
      case Token::BIT_XOR:
        __ xor_(ToRegister(left), right_operand);
        break;
      default:
        UNREACHABLE();
        break;
    }
  } else {
    switch (instr->op()) {
      case Token::BIT_AND:
        __ and_(ToRegister(left), ToOperand(right));
        break;
      case Token::BIT_OR:
        __ or_(ToRegister(left), ToOperand(right));
        break;
      case Token::BIT_XOR:
        __ xor_(ToRegister(left), ToOperand(right));
        break;
      default:
        UNREACHABLE();
        break;
    }
  }
}


void LCodeGen::DoShiftI(LShiftI* instr) {
  LOperand* left = instr->left();
  LOperand* right = instr->right();
  ASSERT(left->Equals(instr->result()));
  ASSERT(left->IsRegister());
  if (right->IsRegister()) {
    ASSERT(ToRegister(right).is(ecx));

    switch (instr->op()) {
      case Token::ROR:
        __ ror_cl(ToRegister(left));
        if (instr->can_deopt()) {
          __ test(ToRegister(left), Immediate(0x80000000));
          DeoptimizeIf(not_zero, instr->environment());
        }
        break;
      case Token::SAR:
        __ sar_cl(ToRegister(left));
        break;
      case Token::SHR:
        __ shr_cl(ToRegister(left));
        if (instr->can_deopt()) {
          __ test(ToRegister(left), Immediate(0x80000000));
          DeoptimizeIf(not_zero, instr->environment());
        }
        break;
      case Token::SHL:
        __ shl_cl(ToRegister(left));
        break;
      default:
        UNREACHABLE();
        break;
    }
  } else {
    int value = ToInteger32(LConstantOperand::cast(right));
    uint8_t shift_count = static_cast<uint8_t>(value & 0x1F);
    switch (instr->op()) {
      case Token::ROR:
        if (shift_count == 0 && instr->can_deopt()) {
          __ test(ToRegister(left), Immediate(0x80000000));
          DeoptimizeIf(not_zero, instr->environment());
        } else {
          __ ror(ToRegister(left), shift_count);
        }
        break;
      case Token::SAR:
        if (shift_count != 0) {
          __ sar(ToRegister(left), shift_count);
        }
        break;
      case Token::SHR:
        if (shift_count == 0 && instr->can_deopt()) {
          __ test(ToRegister(left), Immediate(0x80000000));
          DeoptimizeIf(not_zero, instr->environment());
        } else {
          __ shr(ToRegister(left), shift_count);
        }
        break;
      case Token::SHL:
        if (shift_count != 0) {
          __ shl(ToRegister(left), shift_count);
        }
        break;
      default:
        UNREACHABLE();
        break;
    }
  }
}


void LCodeGen::DoSubI(LSubI* instr) {
  LOperand* left = instr->left();
  LOperand* right = instr->right();
  ASSERT(left->Equals(instr->result()));

  if (right->IsConstantOperand()) {
    __ sub(ToOperand(left), ToInteger32Immediate(right));
  } else {
    __ sub(ToRegister(left), ToOperand(right));
  }
  if (instr->hydrogen()->CheckFlag(HValue::kCanOverflow)) {
    DeoptimizeIf(overflow, instr->environment());
  }
}


void LCodeGen::DoConstantI(LConstantI* instr) {
  __ Set(ToRegister(instr->result()), Immediate(instr->value()));
}


void LCodeGen::DoConstantS(LConstantS* instr) {
  __ Set(ToRegister(instr->result()), Immediate(instr->value()));
}


void LCodeGen::DoConstantD(LConstantD* instr) {
  double v = instr->value();
  uint64_t int_val = BitCast<uint64_t, double>(v);
  int32_t lower = static_cast<int32_t>(int_val);
  int32_t upper = static_cast<int32_t>(int_val >> (kBitsPerInt));

  if (!CpuFeatures::IsSafeForSnapshot(SSE2)) {
    __ push(Immediate(lower));
    __ push(Immediate(upper));
    PushX87DoubleOperand(Operand(esp, 0));
    __ add(Operand(esp), Immediate(kDoubleSize));
    CurrentInstructionReturnsX87Result();
  } else {
    CpuFeatureScope scope1(masm(), SSE2);
    ASSERT(instr->result()->IsDoubleRegister());
    XMMRegister res = ToDoubleRegister(instr->result());
    if (int_val == 0) {
      __ xorps(res, res);
    } else {
      Register temp = ToRegister(instr->temp());
      if (CpuFeatures::IsSupported(SSE4_1)) {
        CpuFeatureScope scope2(masm(), SSE4_1);
        if (lower != 0) {
          __ Set(temp, Immediate(lower));
          __ movd(res, Operand(temp));
          __ Set(temp, Immediate(upper));
          __ pinsrd(res, Operand(temp), 1);
        } else {
          __ xorps(res, res);
          __ Set(temp, Immediate(upper));
          __ pinsrd(res, Operand(temp), 1);
        }
      } else {
        __ Set(temp, Immediate(upper));
        __ movd(res, Operand(temp));
        __ psllq(res, 32);
        if (lower != 0) {
          __ Set(temp, Immediate(lower));
          __ movd(xmm0, Operand(temp));
          __ por(res, xmm0);
        }
      }
    }
  }
}


void LCodeGen::DoConstantT(LConstantT* instr) {
  Register reg = ToRegister(instr->result());
  Handle<Object> handle = instr->value();
  AllowDeferredHandleDereference smi_check;
  if (handle->IsHeapObject()) {
    __ LoadHeapObject(reg, Handle<HeapObject>::cast(handle));
  } else {
    __ Set(reg, Immediate(handle));
  }
}


void LCodeGen::DoFixedArrayBaseLength(
    LFixedArrayBaseLength* instr) {
  Register result = ToRegister(instr->result());
  Register array = ToRegister(instr->value());
  __ mov(result, FieldOperand(array, FixedArrayBase::kLengthOffset));
}


void LCodeGen::DoMapEnumLength(LMapEnumLength* instr) {
  Register result = ToRegister(instr->result());
  Register map = ToRegister(instr->value());
  __ EnumLength(result, map);
}


void LCodeGen::DoElementsKind(LElementsKind* instr) {
  Register result = ToRegister(instr->result());
  Register input = ToRegister(instr->value());

  // Load map into |result|.
  __ mov(result, FieldOperand(input, HeapObject::kMapOffset));
  // Load the map's "bit field 2" into |result|. We only need the first byte,
  // but the following masking takes care of that anyway.
  __ mov(result, FieldOperand(result, Map::kBitField2Offset));
  // Retrieve elements_kind from bit field 2.
  __ and_(result, Map::kElementsKindMask);
  __ shr(result, Map::kElementsKindShift);
}


void LCodeGen::DoValueOf(LValueOf* instr) {
  Register input = ToRegister(instr->value());
  Register result = ToRegister(instr->result());
  Register map = ToRegister(instr->temp());
  ASSERT(input.is(result));

  Label done;
  // If the object is a smi return the object.
  __ JumpIfSmi(input, &done, Label::kNear);

  // If the object is not a value type, return the object.
  __ CmpObjectType(input, JS_VALUE_TYPE, map);
  __ j(not_equal, &done, Label::kNear);
  __ mov(result, FieldOperand(input, JSValue::kValueOffset));

  __ bind(&done);
}


void LCodeGen::DoDateField(LDateField* instr) {
  Register object = ToRegister(instr->date());
  Register result = ToRegister(instr->result());
  Register scratch = ToRegister(instr->temp());
  Smi* index = instr->index();
  Label runtime, done;
  ASSERT(object.is(result));
  ASSERT(object.is(eax));

  __ test(object, Immediate(kSmiTagMask));
  DeoptimizeIf(zero, instr->environment());
  __ CmpObjectType(object, JS_DATE_TYPE, scratch);
  DeoptimizeIf(not_equal, instr->environment());

  if (index->value() == 0) {
    __ mov(result, FieldOperand(object, JSDate::kValueOffset));
  } else {
    if (index->value() < JSDate::kFirstUncachedField) {
      ExternalReference stamp = ExternalReference::date_cache_stamp(isolate());
      __ mov(scratch, Operand::StaticVariable(stamp));
      __ cmp(scratch, FieldOperand(object, JSDate::kCacheStampOffset));
      __ j(not_equal, &runtime, Label::kNear);
      __ mov(result, FieldOperand(object, JSDate::kValueOffset +
                                          kPointerSize * index->value()));
      __ jmp(&done);
    }
    __ bind(&runtime);
    __ PrepareCallCFunction(2, scratch);
    __ mov(Operand(esp, 0), object);
    __ mov(Operand(esp, 1 * kPointerSize), Immediate(index));
    __ CallCFunction(ExternalReference::get_date_field_function(isolate()), 2);
    __ bind(&done);
  }
}


void LCodeGen::DoSeqStringSetChar(LSeqStringSetChar* instr) {
  Register string = ToRegister(instr->string());
  Register index = ToRegister(instr->index());
  Register value = ToRegister(instr->value());
  String::Encoding encoding = instr->encoding();

  if (FLAG_debug_code) {
    __ push(value);
    __ mov(value, FieldOperand(string, HeapObject::kMapOffset));
    __ movzx_b(value, FieldOperand(value, Map::kInstanceTypeOffset));

    __ and_(value, Immediate(kStringRepresentationMask | kStringEncodingMask));
    static const uint32_t one_byte_seq_type = kSeqStringTag | kOneByteStringTag;
    static const uint32_t two_byte_seq_type = kSeqStringTag | kTwoByteStringTag;
    __ cmp(value, Immediate(encoding == String::ONE_BYTE_ENCODING
                                ? one_byte_seq_type : two_byte_seq_type));
    __ Check(equal, "Unexpected string type");
    __ pop(value);
  }

  if (encoding == String::ONE_BYTE_ENCODING) {
    __ mov_b(FieldOperand(string, index, times_1, SeqString::kHeaderSize),
             value);
  } else {
    __ mov_w(FieldOperand(string, index, times_2, SeqString::kHeaderSize),
             value);
  }
}


void LCodeGen::DoBitNotI(LBitNotI* instr) {
  LOperand* input = instr->value();
  ASSERT(input->Equals(instr->result()));
  __ not_(ToRegister(input));
}


void LCodeGen::DoThrow(LThrow* instr) {
  __ push(ToOperand(instr->value()));
  ASSERT(ToRegister(instr->context()).is(esi));
  CallRuntime(Runtime::kThrow, 1, instr);

  if (FLAG_debug_code) {
    Comment("Unreachable code.");
    __ int3();
  }
}


void LCodeGen::DoAddI(LAddI* instr) {
  LOperand* left = instr->left();
  LOperand* right = instr->right();

  if (LAddI::UseLea(instr->hydrogen()) && !left->Equals(instr->result())) {
    if (right->IsConstantOperand()) {
      int32_t offset = ToInteger32(LConstantOperand::cast(right));
      __ lea(ToRegister(instr->result()), MemOperand(ToRegister(left), offset));
    } else {
      Operand address(ToRegister(left), ToRegister(right), times_1, 0);
      __ lea(ToRegister(instr->result()), address);
    }
  } else {
    if (right->IsConstantOperand()) {
      __ add(ToOperand(left), ToInteger32Immediate(right));
    } else {
      __ add(ToRegister(left), ToOperand(right));
    }
    if (instr->hydrogen()->CheckFlag(HValue::kCanOverflow)) {
      DeoptimizeIf(overflow, instr->environment());
    }
  }
}


void LCodeGen::DoMathMinMax(LMathMinMax* instr) {
  CpuFeatureScope scope(masm(), SSE2);
  LOperand* left = instr->left();
  LOperand* right = instr->right();
  ASSERT(left->Equals(instr->result()));
  HMathMinMax::Operation operation = instr->hydrogen()->operation();
  if (instr->hydrogen()->representation().IsInteger32()) {
    Label return_left;
    Condition condition = (operation == HMathMinMax::kMathMin)
        ? less_equal
        : greater_equal;
    if (right->IsConstantOperand()) {
      Operand left_op = ToOperand(left);
      Immediate right_imm = ToInteger32Immediate(right);
      __ cmp(left_op, right_imm);
      __ j(condition, &return_left, Label::kNear);
      __ mov(left_op, right_imm);
    } else {
      Register left_reg = ToRegister(left);
      Operand right_op = ToOperand(right);
      __ cmp(left_reg, right_op);
      __ j(condition, &return_left, Label::kNear);
      __ mov(left_reg, right_op);
    }
    __ bind(&return_left);
  } else {
    ASSERT(instr->hydrogen()->representation().IsDouble());
    Label check_nan_left, check_zero, return_left, return_right;
    Condition condition = (operation == HMathMinMax::kMathMin) ? below : above;
    XMMRegister left_reg = ToDoubleRegister(left);
    XMMRegister right_reg = ToDoubleRegister(right);
    __ ucomisd(left_reg, right_reg);
    __ j(parity_even, &check_nan_left, Label::kNear);  // At least one NaN.
    __ j(equal, &check_zero, Label::kNear);  // left == right.
    __ j(condition, &return_left, Label::kNear);
    __ jmp(&return_right, Label::kNear);

    __ bind(&check_zero);
    XMMRegister xmm_scratch = xmm0;
    __ xorps(xmm_scratch, xmm_scratch);
    __ ucomisd(left_reg, xmm_scratch);
    __ j(not_equal, &return_left, Label::kNear);  // left == right != 0.
    // At this point, both left and right are either 0 or -0.
    if (operation == HMathMinMax::kMathMin) {
      __ orpd(left_reg, right_reg);
    } else {
      // Since we operate on +0 and/or -0, addsd and andsd have the same effect.
      __ addsd(left_reg, right_reg);
    }
    __ jmp(&return_left, Label::kNear);

    __ bind(&check_nan_left);
    __ ucomisd(left_reg, left_reg);  // NaN check.
    __ j(parity_even, &return_left, Label::kNear);  // left == NaN.
    __ bind(&return_right);
    __ movsd(left_reg, right_reg);

    __ bind(&return_left);
  }
}


void LCodeGen::DoArithmeticD(LArithmeticD* instr) {
  CpuFeatureScope scope(masm(), SSE2);
  XMMRegister left = ToDoubleRegister(instr->left());
  XMMRegister right = ToDoubleRegister(instr->right());
  XMMRegister result = ToDoubleRegister(instr->result());
  // Modulo uses a fixed result register.
  ASSERT(instr->op() == Token::MOD || left.is(result));
  switch (instr->op()) {
    case Token::ADD:
      __ addsd(left, right);
      break;
    case Token::SUB:
      __ subsd(left, right);
      break;
    case Token::MUL:
      __ mulsd(left, right);
      break;
    case Token::DIV:
      __ divsd(left, right);
      // Don't delete this mov. It may improve performance on some CPUs,
      // when there is a mulsd depending on the result
      __ movaps(left, left);
      break;
    case Token::MOD: {
      // Pass two doubles as arguments on the stack.
      __ PrepareCallCFunction(4, eax);
      __ movdbl(Operand(esp, 0 * kDoubleSize), left);
      __ movdbl(Operand(esp, 1 * kDoubleSize), right);
      __ CallCFunction(
          ExternalReference::double_fp_operation(Token::MOD, isolate()),
          4);

      // Return value is in st(0) on ia32.
      // Store it into the (fixed) result register.
      __ sub(Operand(esp), Immediate(kDoubleSize));
      __ fstp_d(Operand(esp, 0));
      __ movdbl(result, Operand(esp, 0));
      __ add(Operand(esp), Immediate(kDoubleSize));
      break;
    }
    default:
      UNREACHABLE();
      break;
  }
}


void LCodeGen::DoArithmeticT(LArithmeticT* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  ASSERT(ToRegister(instr->left()).is(edx));
  ASSERT(ToRegister(instr->right()).is(eax));
  ASSERT(ToRegister(instr->result()).is(eax));

  BinaryOpStub stub(instr->op(), NO_OVERWRITE);
  CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
  __ nop();  // Signals no inlined code.
}


int LCodeGen::GetNextEmittedBlock() const {
  for (int i = current_block_ + 1; i < graph()->blocks()->length(); ++i) {
    if (!chunk_->GetLabel(i)->HasReplacement()) return i;
  }
  return -1;
}


void LCodeGen::EmitBranch(int left_block, int right_block, Condition cc) {
  int next_block = GetNextEmittedBlock();
  right_block = chunk_->LookupDestination(right_block);
  left_block = chunk_->LookupDestination(left_block);

  if (right_block == left_block) {
    EmitGoto(left_block);
  } else if (left_block == next_block) {
    __ j(NegateCondition(cc), chunk_->GetAssemblyLabel(right_block));
  } else if (right_block == next_block) {
    __ j(cc, chunk_->GetAssemblyLabel(left_block));
  } else {
    __ j(cc, chunk_->GetAssemblyLabel(left_block));
    __ jmp(chunk_->GetAssemblyLabel(right_block));
  }
}


void LCodeGen::DoBranch(LBranch* instr) {
  int true_block = chunk_->LookupDestination(instr->true_block_id());
  int false_block = chunk_->LookupDestination(instr->false_block_id());

  Representation r = instr->hydrogen()->value()->representation();
  if (r.IsSmiOrInteger32()) {
    ASSERT(!info()->IsStub());
    Register reg = ToRegister(instr->value());
    __ test(reg, Operand(reg));
    EmitBranch(true_block, false_block, not_zero);
  } else if (r.IsDouble()) {
    ASSERT(!info()->IsStub());
    CpuFeatureScope scope(masm(), SSE2);
    XMMRegister reg = ToDoubleRegister(instr->value());
    __ xorps(xmm0, xmm0);
    __ ucomisd(reg, xmm0);
    EmitBranch(true_block, false_block, not_equal);
  } else {
    ASSERT(r.IsTagged());
    Register reg = ToRegister(instr->value());
    HType type = instr->hydrogen()->value()->type();
    if (type.IsBoolean()) {
      ASSERT(!info()->IsStub());
      __ cmp(reg, factory()->true_value());
      EmitBranch(true_block, false_block, equal);
    } else if (type.IsSmi()) {
      ASSERT(!info()->IsStub());
      __ test(reg, Operand(reg));
      EmitBranch(true_block, false_block, not_equal);
    } else {
      Label* true_label = chunk_->GetAssemblyLabel(true_block);
      Label* false_label = chunk_->GetAssemblyLabel(false_block);

      ToBooleanStub::Types expected = instr->hydrogen()->expected_input_types();
      // Avoid deopts in the case where we've never executed this path before.
      if (expected.IsEmpty()) expected = ToBooleanStub::all_types();

      if (expected.Contains(ToBooleanStub::UNDEFINED)) {
        // undefined -> false.
        __ cmp(reg, factory()->undefined_value());
        __ j(equal, false_label);
      }
      if (expected.Contains(ToBooleanStub::BOOLEAN)) {
        // true -> true.
        __ cmp(reg, factory()->true_value());
        __ j(equal, true_label);
        // false -> false.
        __ cmp(reg, factory()->false_value());
        __ j(equal, false_label);
      }
      if (expected.Contains(ToBooleanStub::NULL_TYPE)) {
        // 'null' -> false.
        __ cmp(reg, factory()->null_value());
        __ j(equal, false_label);
      }

      if (expected.Contains(ToBooleanStub::SMI)) {
        // Smis: 0 -> false, all other -> true.
        __ test(reg, Operand(reg));
        __ j(equal, false_label);
        __ JumpIfSmi(reg, true_label);
      } else if (expected.NeedsMap()) {
        // If we need a map later and have a Smi -> deopt.
        __ test(reg, Immediate(kSmiTagMask));
        DeoptimizeIf(zero, instr->environment());
      }

      Register map = no_reg;  // Keep the compiler happy.
      if (expected.NeedsMap()) {
        map = ToRegister(instr->temp());
        ASSERT(!map.is(reg));
        __ mov(map, FieldOperand(reg, HeapObject::kMapOffset));

        if (expected.CanBeUndetectable()) {
          // Undetectable -> false.
          __ test_b(FieldOperand(map, Map::kBitFieldOffset),
                    1 << Map::kIsUndetectable);
          __ j(not_zero, false_label);
        }
      }

      if (expected.Contains(ToBooleanStub::SPEC_OBJECT)) {
        // spec object -> true.
        __ CmpInstanceType(map, FIRST_SPEC_OBJECT_TYPE);
        __ j(above_equal, true_label);
      }

      if (expected.Contains(ToBooleanStub::STRING)) {
        // String value -> false iff empty.
        Label not_string;
        __ CmpInstanceType(map, FIRST_NONSTRING_TYPE);
        __ j(above_equal, &not_string, Label::kNear);
        __ cmp(FieldOperand(reg, String::kLengthOffset), Immediate(0));
        __ j(not_zero, true_label);
        __ jmp(false_label);
        __ bind(&not_string);
      }

      if (expected.Contains(ToBooleanStub::SYMBOL)) {
        // Symbol value -> true.
        __ CmpInstanceType(map, SYMBOL_TYPE);
        __ j(equal, true_label);
      }

      if (expected.Contains(ToBooleanStub::HEAP_NUMBER)) {
        // heap number -> false iff +0, -0, or NaN.
        Label not_heap_number;
        __ cmp(FieldOperand(reg, HeapObject::kMapOffset),
               factory()->heap_number_map());
        __ j(not_equal, &not_heap_number, Label::kNear);
        if (CpuFeatures::IsSafeForSnapshot(SSE2)) {
          CpuFeatureScope scope(masm(), SSE2);
          __ xorps(xmm0, xmm0);
          __ ucomisd(xmm0, FieldOperand(reg, HeapNumber::kValueOffset));
        } else {
          __ fldz();
          __ fld_d(FieldOperand(reg, HeapNumber::kValueOffset));
          __ FCmp();
        }
        __ j(zero, false_label);
        __ jmp(true_label);
        __ bind(&not_heap_number);
      }

      // We've seen something for the first time -> deopt.
      DeoptimizeIf(no_condition, instr->environment());
    }
  }
}


void LCodeGen::EmitGoto(int block) {
  if (!IsNextEmittedBlock(block)) {
    __ jmp(chunk_->GetAssemblyLabel(chunk_->LookupDestination(block)));
  }
}


void LCodeGen::DoGoto(LGoto* instr) {
  EmitGoto(instr->block_id());
}


Condition LCodeGen::TokenToCondition(Token::Value op, bool is_unsigned) {
  Condition cond = no_condition;
  switch (op) {
    case Token::EQ:
    case Token::EQ_STRICT:
      cond = equal;
      break;
    case Token::LT:
      cond = is_unsigned ? below : less;
      break;
    case Token::GT:
      cond = is_unsigned ? above : greater;
      break;
    case Token::LTE:
      cond = is_unsigned ? below_equal : less_equal;
      break;
    case Token::GTE:
      cond = is_unsigned ? above_equal : greater_equal;
      break;
    case Token::IN:
    case Token::INSTANCEOF:
    default:
      UNREACHABLE();
  }
  return cond;
}


void LCodeGen::DoCmpIDAndBranch(LCmpIDAndBranch* instr) {
  LOperand* left = instr->left();
  LOperand* right = instr->right();
  int false_block = chunk_->LookupDestination(instr->false_block_id());
  int true_block = chunk_->LookupDestination(instr->true_block_id());
  Condition cc = TokenToCondition(instr->op(), instr->is_double());

  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 {
    if (instr->is_double()) {
      CpuFeatureScope scope(masm(), SSE2);
      // Don't base result on EFLAGS when a NaN is involved. Instead
      // jump to the false block.
      __ ucomisd(ToDoubleRegister(left), ToDoubleRegister(right));
      __ j(parity_even, chunk_->GetAssemblyLabel(false_block));
    } else {
      if (right->IsConstantOperand()) {
        int32_t const_value = ToInteger32(LConstantOperand::cast(right));
        if (instr->hydrogen_value()->representation().IsSmi()) {
          __ cmp(ToOperand(left), Immediate(Smi::FromInt(const_value)));
        } else {
          __ cmp(ToOperand(left), Immediate(const_value));
        }
      } else if (left->IsConstantOperand()) {
        int32_t const_value = ToInteger32(LConstantOperand::cast(left));
        if (instr->hydrogen_value()->representation().IsSmi()) {
          __ cmp(ToOperand(right), Immediate(Smi::FromInt(const_value)));
        } else {
          __ cmp(ToOperand(right), Immediate(const_value));
        }
        // We transposed the operands. Reverse the condition.
        cc = ReverseCondition(cc);
      } else {
        __ cmp(ToRegister(left), ToOperand(right));
      }
    }
    EmitBranch(true_block, false_block, cc);
  }
}


void LCodeGen::DoCmpObjectEqAndBranch(LCmpObjectEqAndBranch* instr) {
  Register left = ToRegister(instr->left());
  int false_block = chunk_->LookupDestination(instr->false_block_id());
  int true_block = chunk_->LookupDestination(instr->true_block_id());

  if (instr->right()->IsConstantOperand()) {
    Handle<Object> right = ToHandle(LConstantOperand::cast(instr->right()));
    __ CmpObject(left, right);
  } else {
    Operand right = ToOperand(instr->right());
    __ cmp(left, right);
  }
  EmitBranch(true_block, false_block, equal);
}


void LCodeGen::DoCmpConstantEqAndBranch(LCmpConstantEqAndBranch* instr) {
  Register left = ToRegister(instr->left());
  int true_block = chunk_->LookupDestination(instr->true_block_id());
  int false_block = chunk_->LookupDestination(instr->false_block_id());

  __ cmp(left, instr->hydrogen()->right());
  EmitBranch(true_block, false_block, equal);
}


Condition LCodeGen::EmitIsObject(Register input,
                                 Register temp1,
                                 Label* is_not_object,
                                 Label* is_object) {
  __ JumpIfSmi(input, is_not_object);

  __ cmp(input, isolate()->factory()->null_value());
  __ j(equal, is_object);

  __ mov(temp1, FieldOperand(input, HeapObject::kMapOffset));
  // Undetectable objects behave like undefined.
  __ test_b(FieldOperand(temp1, Map::kBitFieldOffset),
            1 << Map::kIsUndetectable);
  __ j(not_zero, is_not_object);

  __ movzx_b(temp1, FieldOperand(temp1, Map::kInstanceTypeOffset));
  __ cmp(temp1, FIRST_NONCALLABLE_SPEC_OBJECT_TYPE);
  __ j(below, is_not_object);
  __ cmp(temp1, LAST_NONCALLABLE_SPEC_OBJECT_TYPE);
  return below_equal;
}


void LCodeGen::DoIsObjectAndBranch(LIsObjectAndBranch* instr) {
  Register reg = ToRegister(instr->value());
  Register temp = ToRegister(instr->temp());

  int true_block = chunk_->LookupDestination(instr->true_block_id());
  int false_block = chunk_->LookupDestination(instr->false_block_id());
  Label* true_label = chunk_->GetAssemblyLabel(true_block);
  Label* false_label = chunk_->GetAssemblyLabel(false_block);

  Condition true_cond = EmitIsObject(reg, temp, false_label, true_label);

  EmitBranch(true_block, false_block, true_cond);
}


Condition LCodeGen::EmitIsString(Register input,
                                 Register temp1,
                                 Label* is_not_string) {
  __ JumpIfSmi(input, is_not_string);

  Condition cond = masm_->IsObjectStringType(input, temp1, temp1);

  return cond;
}


void LCodeGen::DoIsStringAndBranch(LIsStringAndBranch* instr) {
  Register reg = ToRegister(instr->value());
  Register temp = ToRegister(instr->temp());

  int true_block = chunk_->LookupDestination(instr->true_block_id());
  int false_block = chunk_->LookupDestination(instr->false_block_id());
  Label* false_label = chunk_->GetAssemblyLabel(false_block);

  Condition true_cond = EmitIsString(reg, temp, false_label);

  EmitBranch(true_block, false_block, true_cond);
}


void LCodeGen::DoIsSmiAndBranch(LIsSmiAndBranch* instr) {
  Operand input = ToOperand(instr->value());

  int true_block = chunk_->LookupDestination(instr->true_block_id());
  int false_block = chunk_->LookupDestination(instr->false_block_id());

  __ test(input, Immediate(kSmiTagMask));
  EmitBranch(true_block, false_block, zero);
}


void LCodeGen::DoIsUndetectableAndBranch(LIsUndetectableAndBranch* instr) {
  Register input = ToRegister(instr->value());
  Register temp = ToRegister(instr->temp());

  int true_block = chunk_->LookupDestination(instr->true_block_id());
  int false_block = chunk_->LookupDestination(instr->false_block_id());

  STATIC_ASSERT(kSmiTag == 0);
  __ JumpIfSmi(input, chunk_->GetAssemblyLabel(false_block));
  __ mov(temp, FieldOperand(input, HeapObject::kMapOffset));
  __ test_b(FieldOperand(temp, Map::kBitFieldOffset),
            1 << Map::kIsUndetectable);
  EmitBranch(true_block, false_block, not_zero);
}


static Condition ComputeCompareCondition(Token::Value op) {
  switch (op) {
    case Token::EQ_STRICT:
    case Token::EQ:
      return equal;
    case Token::LT:
      return less;
    case Token::GT:
      return greater;
    case Token::LTE:
      return less_equal;
    case Token::GTE:
      return greater_equal;
    default:
      UNREACHABLE();
      return no_condition;
  }
}


void LCodeGen::DoStringCompareAndBranch(LStringCompareAndBranch* instr) {
  Token::Value op = instr->op();
  int true_block = chunk_->LookupDestination(instr->true_block_id());
  int false_block = chunk_->LookupDestination(instr->false_block_id());

  Handle<Code> ic = CompareIC::GetUninitialized(isolate(), op);
  CallCode(ic, RelocInfo::CODE_TARGET, instr);

  Condition condition = ComputeCompareCondition(op);
  __ test(eax, Operand(eax));

  EmitBranch(true_block, false_block, condition);
}


static InstanceType TestType(HHasInstanceTypeAndBranch* instr) {
  InstanceType from = instr->from();
  InstanceType to = instr->to();
  if (from == FIRST_TYPE) return to;
  ASSERT(from == to || to == LAST_TYPE);
  return from;
}


static Condition BranchCondition(HHasInstanceTypeAndBranch* instr) {
  InstanceType from = instr->from();
  InstanceType to = instr->to();
  if (from == to) return equal;
  if (to == LAST_TYPE) return above_equal;
  if (from == FIRST_TYPE) return below_equal;
  UNREACHABLE();
  return equal;
}


void LCodeGen::DoHasInstanceTypeAndBranch(LHasInstanceTypeAndBranch* instr) {
  Register input = ToRegister(instr->value());
  Register temp = ToRegister(instr->temp());

  int true_block = chunk_->LookupDestination(instr->true_block_id());
  int false_block = chunk_->LookupDestination(instr->false_block_id());

  Label* false_label = chunk_->GetAssemblyLabel(false_block);

  __ JumpIfSmi(input, false_label);

  __ CmpObjectType(input, TestType(instr->hydrogen()), temp);
  EmitBranch(true_block, false_block, BranchCondition(instr->hydrogen()));
}


void LCodeGen::DoGetCachedArrayIndex(LGetCachedArrayIndex* instr) {
  Register input = ToRegister(instr->value());
  Register result = ToRegister(instr->result());

  __ AssertString(input);

  __ mov(result, FieldOperand(input, String::kHashFieldOffset));
  __ IndexFromHash(result, result);
}


void LCodeGen::DoHasCachedArrayIndexAndBranch(
    LHasCachedArrayIndexAndBranch* instr) {
  Register input = ToRegister(instr->value());

  int true_block = chunk_->LookupDestination(instr->true_block_id());
  int false_block = chunk_->LookupDestination(instr->false_block_id());

  __ test(FieldOperand(input, String::kHashFieldOffset),
          Immediate(String::kContainsCachedArrayIndexMask));
  EmitBranch(true_block, false_block, equal);
}


// Branches to a label or falls through with the answer in the z flag.  Trashes
// the temp registers, but not the input.
void LCodeGen::EmitClassOfTest(Label* is_true,
                               Label* is_false,
                               Handle<String>class_name,
                               Register input,
                               Register temp,
                               Register temp2) {
  ASSERT(!input.is(temp));
  ASSERT(!input.is(temp2));
  ASSERT(!temp.is(temp2));
  __ JumpIfSmi(input, is_false);

  if (class_name->IsOneByteEqualTo(STATIC_ASCII_VECTOR("Function"))) {
    // Assuming the following assertions, we can use the same compares to test
    // for both being a function type and being in the object type range.
    STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
    STATIC_ASSERT(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE ==
                  FIRST_SPEC_OBJECT_TYPE + 1);
    STATIC_ASSERT(LAST_NONCALLABLE_SPEC_OBJECT_TYPE ==
                  LAST_SPEC_OBJECT_TYPE - 1);
    STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
    __ CmpObjectType(input, FIRST_SPEC_OBJECT_TYPE, temp);
    __ j(below, is_false);
    __ j(equal, is_true);
    __ CmpInstanceType(temp, LAST_SPEC_OBJECT_TYPE);
    __ j(equal, is_true);
  } else {
    // Faster code path to avoid two compares: subtract lower bound from the
    // actual type and do a signed compare with the width of the type range.
    __ mov(temp, FieldOperand(input, HeapObject::kMapOffset));
    __ movzx_b(temp2, FieldOperand(temp, Map::kInstanceTypeOffset));
    __ sub(Operand(temp2), Immediate(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
    __ cmp(Operand(temp2), Immediate(LAST_NONCALLABLE_SPEC_OBJECT_TYPE -
                                     FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
    __ j(above, is_false);
  }

  // Now we are in the FIRST-LAST_NONCALLABLE_SPEC_OBJECT_TYPE range.
  // Check if the constructor in the map is a function.
  __ mov(temp, FieldOperand(temp, Map::kConstructorOffset));
  // Objects with a non-function constructor have class 'Object'.
  __ CmpObjectType(temp, JS_FUNCTION_TYPE, temp2);
  if (class_name->IsOneByteEqualTo(STATIC_ASCII_VECTOR("Object"))) {
    __ j(not_equal, is_true);
  } else {
    __ j(not_equal, is_false);
  }

  // temp now contains the constructor function. Grab the
  // instance class name from there.
  __ mov(temp, FieldOperand(temp, JSFunction::kSharedFunctionInfoOffset));
  __ mov(temp, FieldOperand(temp,
                            SharedFunctionInfo::kInstanceClassNameOffset));
  // The class name we are testing against is internalized since it's a literal.
  // The name in the constructor is internalized because of the way the context
  // is booted.  This routine isn't expected to work for random API-created
  // classes and it doesn't have to because you can't access it with natives
  // syntax.  Since both sides are internalized it is sufficient to use an
  // identity comparison.
  __ cmp(temp, class_name);
  // End with the answer in the z flag.
}


void LCodeGen::DoClassOfTestAndBranch(LClassOfTestAndBranch* instr) {
  Register input = ToRegister(instr->value());
  Register temp = ToRegister(instr->temp());
  Register temp2 = ToRegister(instr->temp2());

  Handle<String> class_name = instr->hydrogen()->class_name();

  int true_block = chunk_->LookupDestination(instr->true_block_id());
  int false_block = chunk_->LookupDestination(instr->false_block_id());

  Label* true_label = chunk_->GetAssemblyLabel(true_block);
  Label* false_label = chunk_->GetAssemblyLabel(false_block);

  EmitClassOfTest(true_label, false_label, class_name, input, temp, temp2);

  EmitBranch(true_block, false_block, equal);
}


void LCodeGen::DoCmpMapAndBranch(LCmpMapAndBranch* instr) {
  Register reg = ToRegister(instr->value());
  int true_block = instr->true_block_id();
  int false_block = instr->false_block_id();

  __ cmp(FieldOperand(reg, HeapObject::kMapOffset), instr->map());
  EmitBranch(true_block, false_block, equal);
}


void LCodeGen::DoInstanceOf(LInstanceOf* instr) {
  // Object and function are in fixed registers defined by the stub.
  ASSERT(ToRegister(instr->context()).is(esi));
  InstanceofStub stub(InstanceofStub::kArgsInRegisters);
  CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);

  Label true_value, done;
  __ test(eax, Operand(eax));
  __ j(zero, &true_value, Label::kNear);
  __ mov(ToRegister(instr->result()), factory()->false_value());
  __ jmp(&done, Label::kNear);
  __ bind(&true_value);
  __ mov(ToRegister(instr->result()), factory()->true_value());
  __ bind(&done);
}


void LCodeGen::DoInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr) {
  class DeferredInstanceOfKnownGlobal: public LDeferredCode {
   public:
    DeferredInstanceOfKnownGlobal(LCodeGen* codegen,
                                  LInstanceOfKnownGlobal* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() {
      codegen()->DoDeferredInstanceOfKnownGlobal(instr_, &map_check_);
    }
    virtual LInstruction* instr() { return instr_; }
    Label* map_check() { return &map_check_; }
   private:
    LInstanceOfKnownGlobal* instr_;
    Label map_check_;
  };

  DeferredInstanceOfKnownGlobal* deferred;
  deferred = new(zone()) DeferredInstanceOfKnownGlobal(this, instr);

  Label done, false_result;
  Register object = ToRegister(instr->value());
  Register temp = ToRegister(instr->temp());

  // A Smi is not an instance of anything.
  __ JumpIfSmi(object, &false_result);

  // This is the inlined call site instanceof cache. The two occurences of the
  // hole value will be patched to the last map/result pair generated by the
  // instanceof stub.
  Label cache_miss;
  Register map = ToRegister(instr->temp());
  __ mov(map, FieldOperand(object, HeapObject::kMapOffset));
  __ bind(deferred->map_check());  // Label for calculating code patching.
  Handle<JSGlobalPropertyCell> cache_cell =
      factory()->NewJSGlobalPropertyCell(factory()->the_hole_value());
  __ cmp(map, Operand::Cell(cache_cell));  // Patched to cached map.
  __ j(not_equal, &cache_miss, Label::kNear);
  __ mov(eax, factory()->the_hole_value());  // Patched to either true or false.
  __ jmp(&done);

  // The inlined call site cache did not match. Check for null and string
  // before calling the deferred code.
  __ bind(&cache_miss);
  // Null is not an instance of anything.
  __ cmp(object, factory()->null_value());
  __ j(equal, &false_result);

  // String values are not instances of anything.
  Condition is_string = masm_->IsObjectStringType(object, temp, temp);
  __ j(is_string, &false_result);

  // Go to the deferred code.
  __ jmp(deferred->entry());

  __ bind(&false_result);
  __ mov(ToRegister(instr->result()), factory()->false_value());

  // Here result has either true or false. Deferred code also produces true or
  // false object.
  __ bind(deferred->exit());
  __ bind(&done);
}


void LCodeGen::DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,
                                               Label* map_check) {
  PushSafepointRegistersScope scope(this);

  InstanceofStub::Flags flags = InstanceofStub::kNoFlags;
  flags = static_cast<InstanceofStub::Flags>(
      flags | InstanceofStub::kArgsInRegisters);
  flags = static_cast<InstanceofStub::Flags>(
      flags | InstanceofStub::kCallSiteInlineCheck);
  flags = static_cast<InstanceofStub::Flags>(
      flags | InstanceofStub::kReturnTrueFalseObject);
  InstanceofStub stub(flags);

  // Get the temp register reserved by the instruction. This needs to be a
  // register which is pushed last by PushSafepointRegisters as top of the
  // stack is used to pass the offset to the location of the map check to
  // the stub.
  Register temp = ToRegister(instr->temp());
  ASSERT(MacroAssembler::SafepointRegisterStackIndex(temp) == 0);
  __ LoadHeapObject(InstanceofStub::right(), instr->function());
  static const int kAdditionalDelta = 13;
  int delta = masm_->SizeOfCodeGeneratedSince(map_check) + kAdditionalDelta;
  __ mov(temp, Immediate(delta));
  __ StoreToSafepointRegisterSlot(temp, temp);
  CallCodeGeneric(stub.GetCode(isolate()),
                  RelocInfo::CODE_TARGET,
                  instr,
                  RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
  // Get the deoptimization index of the LLazyBailout-environment that
  // corresponds to this instruction.
  LEnvironment* env = instr->GetDeferredLazyDeoptimizationEnvironment();
  safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());

  // Put the result value into the eax slot and restore all registers.
  __ StoreToSafepointRegisterSlot(eax, eax);
}


void LCodeGen::DoInstanceSize(LInstanceSize* instr) {
  Register object = ToRegister(instr->object());
  Register result = ToRegister(instr->result());
  __ mov(result, FieldOperand(object, HeapObject::kMapOffset));
  __ movzx_b(result, FieldOperand(result, Map::kInstanceSizeOffset));
}


void LCodeGen::DoCmpT(LCmpT* instr) {
  Token::Value op = instr->op();

  Handle<Code> ic = CompareIC::GetUninitialized(isolate(), op);
  CallCode(ic, RelocInfo::CODE_TARGET, instr);

  Condition condition = ComputeCompareCondition(op);
  Label true_value, done;
  __ test(eax, Operand(eax));
  __ j(condition, &true_value, Label::kNear);
  __ mov(ToRegister(instr->result()), factory()->false_value());
  __ jmp(&done, Label::kNear);
  __ bind(&true_value);
  __ mov(ToRegister(instr->result()), factory()->true_value());
  __ bind(&done);
}


void LCodeGen::EmitReturn(LReturn* instr, bool dynamic_frame_alignment) {
  int extra_value_count = dynamic_frame_alignment ? 2 : 1;

  if (instr->has_constant_parameter_count()) {
    int parameter_count = ToInteger32(instr->constant_parameter_count());
    if (dynamic_frame_alignment && FLAG_debug_code) {
      __ cmp(Operand(esp,
                     (parameter_count + extra_value_count) * kPointerSize),
             Immediate(kAlignmentZapValue));
      __ Assert(equal, "expected alignment marker");
    }
    __ Ret((parameter_count + extra_value_count) * kPointerSize, ecx);
  } else {
    Register reg = ToRegister(instr->parameter_count());
    // The argument count parameter is a smi
    __ SmiUntag(reg);
    Register return_addr_reg = reg.is(ecx) ? ebx : ecx;
    if (dynamic_frame_alignment && FLAG_debug_code) {
      ASSERT(extra_value_count == 2);
      __ cmp(Operand(esp, reg, times_pointer_size,
                     extra_value_count * kPointerSize),
             Immediate(kAlignmentZapValue));
      __ Assert(equal, "expected alignment marker");
    }

    // emit code to restore stack based on instr->parameter_count()
    __ pop(return_addr_reg);  // save return address
    if (dynamic_frame_alignment) {
      __ inc(reg);  // 1 more for alignment
    }
    __ shl(reg, kPointerSizeLog2);
    __ add(esp, reg);
    __ jmp(return_addr_reg);
  }
}


void LCodeGen::DoReturn(LReturn* instr) {
  if (FLAG_trace && info()->IsOptimizing()) {
    // Preserve the return value on the stack and rely on the runtime call
    // to return the value in the same register.  We're leaving the code
    // managed by the register allocator and tearing down the frame, it's
    // safe to write to the context register.
    __ push(eax);
    __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
    __ CallRuntime(Runtime::kTraceExit, 1);
  }
  if (info()->saves_caller_doubles() && CpuFeatures::IsSupported(SSE2)) {
    ASSERT(NeedsEagerFrame());
    CpuFeatureScope scope(masm(), SSE2);
    BitVector* doubles = chunk()->allocated_double_registers();
    BitVector::Iterator save_iterator(doubles);
    int count = 0;
    while (!save_iterator.Done()) {
      __ movdbl(XMMRegister::FromAllocationIndex(save_iterator.Current()),
                MemOperand(esp, count * kDoubleSize));
      save_iterator.Advance();
      count++;
    }
  }
  if (dynamic_frame_alignment_) {
    // Fetch the state of the dynamic frame alignment.
    __ mov(edx, Operand(ebp,
      JavaScriptFrameConstants::kDynamicAlignmentStateOffset));
  }
  int no_frame_start = -1;
  if (NeedsEagerFrame()) {
    __ mov(esp, ebp);
    __ pop(ebp);
    no_frame_start = masm_->pc_offset();
  }
  if (dynamic_frame_alignment_) {
    Label no_padding;
    __ cmp(edx, Immediate(kNoAlignmentPadding));
    __ j(equal, &no_padding);

    EmitReturn(instr, true);
    __ bind(&no_padding);
  }

  EmitReturn(instr, false);
  if (no_frame_start != -1) {
    info()->AddNoFrameRange(no_frame_start, masm_->pc_offset());
  }
}


void LCodeGen::DoLoadGlobalCell(LLoadGlobalCell* instr) {
  Register result = ToRegister(instr->result());
  __ mov(result, Operand::Cell(instr->hydrogen()->cell()));
  if (instr->hydrogen()->RequiresHoleCheck()) {
    __ cmp(result, factory()->the_hole_value());
    DeoptimizeIf(equal, instr->environment());
  }
}


void LCodeGen::DoLoadGlobalGeneric(LLoadGlobalGeneric* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  ASSERT(ToRegister(instr->global_object()).is(edx));
  ASSERT(ToRegister(instr->result()).is(eax));

  __ mov(ecx, instr->name());
  RelocInfo::Mode mode = instr->for_typeof() ? RelocInfo::CODE_TARGET :
                                               RelocInfo::CODE_TARGET_CONTEXT;
  Handle<Code> ic = isolate()->builtins()->LoadIC_Initialize();
  CallCode(ic, mode, instr);
}


void LCodeGen::DoStoreGlobalCell(LStoreGlobalCell* instr) {
  Register value = ToRegister(instr->value());
  Handle<JSGlobalPropertyCell> cell_handle = instr->hydrogen()->cell();

  // If the cell we are storing to contains the hole it could have
  // been deleted from the property dictionary. In that case, we need
  // to update the property details in the property dictionary to mark
  // it as no longer deleted. We deoptimize in that case.
  if (instr->hydrogen()->RequiresHoleCheck()) {
    __ cmp(Operand::Cell(cell_handle), factory()->the_hole_value());
    DeoptimizeIf(equal, instr->environment());
  }

  // Store the value.
  __ mov(Operand::Cell(cell_handle), value);
  // Cells are always rescanned, so no write barrier here.
}


void LCodeGen::DoStoreGlobalGeneric(LStoreGlobalGeneric* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  ASSERT(ToRegister(instr->global_object()).is(edx));
  ASSERT(ToRegister(instr->value()).is(eax));

  __ mov(ecx, instr->name());
  Handle<Code> ic = (instr->strict_mode_flag() == kStrictMode)
      ? isolate()->builtins()->StoreIC_Initialize_Strict()
      : isolate()->builtins()->StoreIC_Initialize();
  CallCode(ic, RelocInfo::CODE_TARGET_CONTEXT, instr);
}


void LCodeGen::DoLoadContextSlot(LLoadContextSlot* instr) {
  Register context = ToRegister(instr->context());
  Register result = ToRegister(instr->result());
  __ mov(result, ContextOperand(context, instr->slot_index()));

  if (instr->hydrogen()->RequiresHoleCheck()) {
    __ cmp(result, factory()->the_hole_value());
    if (instr->hydrogen()->DeoptimizesOnHole()) {
      DeoptimizeIf(equal, instr->environment());
    } else {
      Label is_not_hole;
      __ j(not_equal, &is_not_hole, Label::kNear);
      __ mov(result, factory()->undefined_value());
      __ bind(&is_not_hole);
    }
  }
}


void LCodeGen::DoStoreContextSlot(LStoreContextSlot* instr) {
  Register context = ToRegister(instr->context());
  Register value = ToRegister(instr->value());

  Label skip_assignment;

  Operand target = ContextOperand(context, instr->slot_index());
  if (instr->hydrogen()->RequiresHoleCheck()) {
    __ cmp(target, factory()->the_hole_value());
    if (instr->hydrogen()->DeoptimizesOnHole()) {
      DeoptimizeIf(equal, instr->environment());
    } else {
      __ j(not_equal, &skip_assignment, Label::kNear);
    }
  }

  __ mov(target, value);
  if (instr->hydrogen()->NeedsWriteBarrier()) {
    HType type = instr->hydrogen()->value()->type();
    SmiCheck check_needed =
        type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
    Register temp = ToRegister(instr->temp());
    int offset = Context::SlotOffset(instr->slot_index());
    __ RecordWriteContextSlot(context,
                              offset,
                              value,
                              temp,
                              GetSaveFPRegsMode(),
                              EMIT_REMEMBERED_SET,
                              check_needed);
  }

  __ bind(&skip_assignment);
}


void LCodeGen::DoLoadNamedField(LLoadNamedField* instr) {
  HObjectAccess access = instr->hydrogen()->access();
  int offset = access.offset();
  Register object = ToRegister(instr->object());
  if (FLAG_track_double_fields &&
      instr->hydrogen()->representation().IsDouble()) {
    if (CpuFeatures::IsSupported(SSE2)) {
      CpuFeatureScope scope(masm(), SSE2);
      XMMRegister result = ToDoubleRegister(instr->result());
      __ movdbl(result, FieldOperand(object, offset));
    } else {
      PushX87DoubleOperand(FieldOperand(object, offset));
      CurrentInstructionReturnsX87Result();
    }
    return;
  }

  Register result = ToRegister(instr->result());
  if (access.IsInobject()) {
    __ mov(result, FieldOperand(object, offset));
  } else {
    __ mov(result, FieldOperand(object, JSObject::kPropertiesOffset));
    __ mov(result, FieldOperand(result, offset));
  }
}


void LCodeGen::EmitLoadFieldOrConstantFunction(Register result,
                                               Register object,
                                               Handle<Map> type,
                                               Handle<String> name,
                                               LEnvironment* env) {
  LookupResult lookup(isolate());
  type->LookupDescriptor(NULL, *name, &lookup);
  ASSERT(lookup.IsFound() || lookup.IsCacheable());
  if (lookup.IsField()) {
    int index = lookup.GetLocalFieldIndexFromMap(*type);
    int offset = index * kPointerSize;
    if (index < 0) {
      // Negative property indices are in-object properties, indexed
      // from the end of the fixed part of the object.
      __ mov(result, FieldOperand(object, offset + type->instance_size()));
    } else {
      // Non-negative property indices are in the properties array.
      __ mov(result, FieldOperand(object, JSObject::kPropertiesOffset));
      __ mov(result, FieldOperand(result, offset + FixedArray::kHeaderSize));
    }
  } else if (lookup.IsConstantFunction()) {
    Handle<JSFunction> function(lookup.GetConstantFunctionFromMap(*type));
    __ LoadHeapObject(result, function);
  } else {
    // Negative lookup.
    // Check prototypes.
    Handle<HeapObject> current(HeapObject::cast((*type)->prototype()));
    Heap* heap = type->GetHeap();
    while (*current != heap->null_value()) {
      __ LoadHeapObject(result, current);
      __ cmp(FieldOperand(result, HeapObject::kMapOffset),
                          Handle<Map>(current->map()));
      DeoptimizeIf(not_equal, env);
      current =
          Handle<HeapObject>(HeapObject::cast(current->map()->prototype()));
    }
    __ mov(result, factory()->undefined_value());
  }
}


void LCodeGen::EmitPushTaggedOperand(LOperand* operand) {
  ASSERT(!operand->IsDoubleRegister());
  if (operand->IsConstantOperand()) {
    Handle<Object> object = ToHandle(LConstantOperand::cast(operand));
    AllowDeferredHandleDereference smi_check;
    if (object->IsSmi()) {
      __ Push(Handle<Smi>::cast(object));
    } else {
      __ PushHeapObject(Handle<HeapObject>::cast(object));
    }
  } else if (operand->IsRegister()) {
    __ push(ToRegister(operand));
  } else {
    __ push(ToOperand(operand));
  }
}


// Check for cases where EmitLoadFieldOrConstantFunction needs to walk the
// prototype chain, which causes unbounded code generation.
static bool CompactEmit(SmallMapList* list,
                        Handle<String> name,
                        int i,
                        Isolate* isolate) {
  Handle<Map> map = list->at(i);
  // If the map has ElementsKind transitions, we will generate map checks
  // for each kind in __ CompareMap(..., ALLOW_ELEMENTS_TRANSITION_MAPS).
  if (map->HasElementsTransition()) return false;
  LookupResult lookup(isolate);
  map->LookupDescriptor(NULL, *name, &lookup);
  return lookup.IsField() || lookup.IsConstantFunction();
}


void LCodeGen::DoLoadNamedFieldPolymorphic(LLoadNamedFieldPolymorphic* instr) {
  Register object = ToRegister(instr->object());
  Register result = ToRegister(instr->result());

  int map_count = instr->hydrogen()->types()->length();
  bool need_generic = instr->hydrogen()->need_generic();

  if (map_count == 0 && !need_generic) {
    DeoptimizeIf(no_condition, instr->environment());
    return;
  }
  Handle<String> name = instr->hydrogen()->name();
  Label done;
  bool all_are_compact = true;
  for (int i = 0; i < map_count; ++i) {
    if (!CompactEmit(instr->hydrogen()->types(), name, i, isolate())) {
      all_are_compact = false;
      break;
    }
  }
  for (int i = 0; i < map_count; ++i) {
    bool last = (i == map_count - 1);
    Handle<Map> map = instr->hydrogen()->types()->at(i);
    Label check_passed;
    __ CompareMap(object, map, &check_passed);
    if (last && !need_generic) {
      DeoptimizeIf(not_equal, instr->environment());
      __ bind(&check_passed);
      EmitLoadFieldOrConstantFunction(
          result, object, map, name, instr->environment());
    } else {
      Label next;
      bool compact = all_are_compact ? true :
          CompactEmit(instr->hydrogen()->types(), name, i, isolate());
      __ j(not_equal, &next, compact ? Label::kNear : Label::kFar);
      __ bind(&check_passed);
      EmitLoadFieldOrConstantFunction(
          result, object, map, name, instr->environment());
      __ jmp(&done, all_are_compact ? Label::kNear : Label::kFar);
      __ bind(&next);
    }
  }
  if (need_generic) {
    __ mov(ecx, name);
    Handle<Code> ic = isolate()->builtins()->LoadIC_Initialize();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
  }
  __ bind(&done);
}


void LCodeGen::DoLoadNamedGeneric(LLoadNamedGeneric* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  ASSERT(ToRegister(instr->object()).is(edx));
  ASSERT(ToRegister(instr->result()).is(eax));

  __ mov(ecx, instr->name());
  Handle<Code> ic = isolate()->builtins()->LoadIC_Initialize();
  CallCode(ic, RelocInfo::CODE_TARGET, instr);
}


void LCodeGen::DoLoadFunctionPrototype(LLoadFunctionPrototype* instr) {
  Register function = ToRegister(instr->function());
  Register temp = ToRegister(instr->temp());
  Register result = ToRegister(instr->result());

  // Check that the function really is a function.
  __ CmpObjectType(function, JS_FUNCTION_TYPE, result);
  DeoptimizeIf(not_equal, instr->environment());

  // Check whether the function has an instance prototype.
  Label non_instance;
  __ test_b(FieldOperand(result, Map::kBitFieldOffset),
            1 << Map::kHasNonInstancePrototype);
  __ j(not_zero, &non_instance, Label::kNear);

  // Get the prototype or initial map from the function.
  __ mov(result,
         FieldOperand(function, JSFunction::kPrototypeOrInitialMapOffset));

  // Check that the function has a prototype or an initial map.
  __ cmp(Operand(result), Immediate(factory()->the_hole_value()));
  DeoptimizeIf(equal, instr->environment());

  // If the function does not have an initial map, we're done.
  Label done;
  __ CmpObjectType(result, MAP_TYPE, temp);
  __ j(not_equal, &done, Label::kNear);

  // Get the prototype from the initial map.
  __ mov(result, FieldOperand(result, Map::kPrototypeOffset));
  __ jmp(&done, Label::kNear);

  // Non-instance prototype: Fetch prototype from constructor field
  // in the function's map.
  __ bind(&non_instance);
  __ mov(result, FieldOperand(result, Map::kConstructorOffset));

  // All done.
  __ bind(&done);
}


void LCodeGen::DoLoadExternalArrayPointer(
    LLoadExternalArrayPointer* instr) {
  Register result = ToRegister(instr->result());
  Register input = ToRegister(instr->object());
  __ mov(result, FieldOperand(input,
                              ExternalArray::kExternalPointerOffset));
}


void LCodeGen::DoAccessArgumentsAt(LAccessArgumentsAt* instr) {
  Register arguments = ToRegister(instr->arguments());
  Register result = ToRegister(instr->result());
  if (instr->length()->IsConstantOperand() &&
      instr->index()->IsConstantOperand()) {
    int const_index = ToInteger32(LConstantOperand::cast(instr->index()));
    int const_length = ToInteger32(LConstantOperand::cast(instr->length()));
    int index = (const_length - const_index) + 1;
    __ mov(result, Operand(arguments, index * kPointerSize));
  } else {
    Register length = ToRegister(instr->length());
    Operand index = ToOperand(instr->index());
    // There are two words between the frame pointer and the last argument.
    // Subtracting from length accounts for one of them add one more.
    __ sub(length, index);
    __ mov(result, Operand(arguments, length, times_4, kPointerSize));
  }
}


void LCodeGen::DoLoadKeyedExternalArray(LLoadKeyed* instr) {
  ElementsKind elements_kind = instr->elements_kind();
  LOperand* key = instr->key();
  if (!key->IsConstantOperand() &&
      ExternalArrayOpRequiresTemp(instr->hydrogen()->key()->representation(),
                                  elements_kind)) {
    __ SmiUntag(ToRegister(key));
  }
  Operand operand(BuildFastArrayOperand(
      instr->elements(),
      key,
      instr->hydrogen()->key()->representation(),
      elements_kind,
      0,
      instr->additional_index()));
  if (elements_kind == EXTERNAL_FLOAT_ELEMENTS) {
    if (CpuFeatures::IsSupported(SSE2)) {
      CpuFeatureScope scope(masm(), SSE2);
      XMMRegister result(ToDoubleRegister(instr->result()));
      __ movss(result, operand);
      __ cvtss2sd(result, result);
    } else {
      PushX87FloatOperand(operand);
      CurrentInstructionReturnsX87Result();
    }
  } else if (elements_kind == EXTERNAL_DOUBLE_ELEMENTS) {
    if (CpuFeatures::IsSupported(SSE2)) {
      CpuFeatureScope scope(masm(), SSE2);
      __ movdbl(ToDoubleRegister(instr->result()), operand);
    } else {
      PushX87DoubleOperand(operand);
      CurrentInstructionReturnsX87Result();
    }
  } else {
    Register result(ToRegister(instr->result()));
    switch (elements_kind) {
      case EXTERNAL_BYTE_ELEMENTS:
        __ movsx_b(result, operand);
        break;
      case EXTERNAL_PIXEL_ELEMENTS:
      case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
        __ movzx_b(result, operand);
        break;
      case EXTERNAL_SHORT_ELEMENTS:
        __ movsx_w(result, operand);
        break;
      case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
        __ movzx_w(result, operand);
        break;
      case EXTERNAL_INT_ELEMENTS:
        __ mov(result, operand);
        break;
      case EXTERNAL_UNSIGNED_INT_ELEMENTS:
        __ mov(result, operand);
        if (!instr->hydrogen()->CheckFlag(HInstruction::kUint32)) {
          __ test(result, Operand(result));
          DeoptimizeIf(negative, instr->environment());
        }
        break;
      case EXTERNAL_FLOAT_ELEMENTS:
      case EXTERNAL_DOUBLE_ELEMENTS:
      case FAST_SMI_ELEMENTS:
      case FAST_ELEMENTS:
      case FAST_DOUBLE_ELEMENTS:
      case FAST_HOLEY_SMI_ELEMENTS:
      case FAST_HOLEY_ELEMENTS:
      case FAST_HOLEY_DOUBLE_ELEMENTS:
      case DICTIONARY_ELEMENTS:
      case NON_STRICT_ARGUMENTS_ELEMENTS:
        UNREACHABLE();
        break;
    }
  }
}


void LCodeGen::DoLoadKeyedFixedDoubleArray(LLoadKeyed* instr) {
  if (instr->hydrogen()->RequiresHoleCheck()) {
    int offset = FixedDoubleArray::kHeaderSize - kHeapObjectTag +
        sizeof(kHoleNanLower32);
    Operand hole_check_operand = BuildFastArrayOperand(
        instr->elements(), instr->key(),
        instr->hydrogen()->key()->representation(),
        FAST_DOUBLE_ELEMENTS,
        offset,
        instr->additional_index());
    __ cmp(hole_check_operand, Immediate(kHoleNanUpper32));
    DeoptimizeIf(equal, instr->environment());
  }

  Operand double_load_operand = BuildFastArrayOperand(
      instr->elements(),
      instr->key(),
      instr->hydrogen()->key()->representation(),
      FAST_DOUBLE_ELEMENTS,
      FixedDoubleArray::kHeaderSize - kHeapObjectTag,
      instr->additional_index());
  if (CpuFeatures::IsSupported(SSE2)) {
    CpuFeatureScope scope(masm(), SSE2);
    XMMRegister result = ToDoubleRegister(instr->result());
    __ movdbl(result, double_load_operand);
  } else {
    PushX87DoubleOperand(double_load_operand);
    CurrentInstructionReturnsX87Result();
  }
}


void LCodeGen::DoLoadKeyedFixedArray(LLoadKeyed* instr) {
  Register result = ToRegister(instr->result());

  // Load the result.
  __ mov(result,
         BuildFastArrayOperand(instr->elements(),
                               instr->key(),
                               instr->hydrogen()->key()->representation(),
                               FAST_ELEMENTS,
                               FixedArray::kHeaderSize - kHeapObjectTag,
                               instr->additional_index()));

  // Check for the hole value.
  if (instr->hydrogen()->RequiresHoleCheck()) {
    if (IsFastSmiElementsKind(instr->hydrogen()->elements_kind())) {
      __ test(result, Immediate(kSmiTagMask));
      DeoptimizeIf(not_equal, instr->environment());
    } else {
      __ cmp(result, factory()->the_hole_value());
      DeoptimizeIf(equal, instr->environment());
    }
  }
}


void LCodeGen::DoLoadKeyed(LLoadKeyed* instr) {
  if (instr->is_external()) {
    DoLoadKeyedExternalArray(instr);
  } else if (instr->hydrogen()->representation().IsDouble()) {
    DoLoadKeyedFixedDoubleArray(instr);
  } else {
    DoLoadKeyedFixedArray(instr);
  }
}


Operand LCodeGen::BuildFastArrayOperand(
    LOperand* elements_pointer,
    LOperand* key,
    Representation key_representation,
    ElementsKind elements_kind,
    uint32_t offset,
    uint32_t additional_index) {
  Register elements_pointer_reg = ToRegister(elements_pointer);
  int element_shift_size = ElementsKindToShiftSize(elements_kind);
  int shift_size = element_shift_size;
  if (key->IsConstantOperand()) {
    int constant_value = ToInteger32(LConstantOperand::cast(key));
    if (constant_value & 0xF0000000) {
      Abort("array index constant value too big");
    }
    return Operand(elements_pointer_reg,
                   ((constant_value + additional_index) << shift_size)
                       + offset);
  } else {
    // Take the tag bit into account while computing the shift size.
    if (key_representation.IsSmi() && (shift_size >= 1)) {
      shift_size -= kSmiTagSize;
    }
    ScaleFactor scale_factor = static_cast<ScaleFactor>(shift_size);
    return Operand(elements_pointer_reg,
                   ToRegister(key),
                   scale_factor,
                   offset + (additional_index << element_shift_size));
  }
}


void LCodeGen::DoLoadKeyedGeneric(LLoadKeyedGeneric* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  ASSERT(ToRegister(instr->object()).is(edx));
  ASSERT(ToRegister(instr->key()).is(ecx));

  Handle<Code> ic = isolate()->builtins()->KeyedLoadIC_Initialize();
  CallCode(ic, RelocInfo::CODE_TARGET, instr);
}


void LCodeGen::DoArgumentsElements(LArgumentsElements* instr) {
  Register result = ToRegister(instr->result());

  if (instr->hydrogen()->from_inlined()) {
    __ lea(result, Operand(esp, -2 * kPointerSize));
  } else {
    // Check for arguments adapter frame.
    Label done, adapted;
    __ mov(result, Operand(ebp, StandardFrameConstants::kCallerFPOffset));
    __ mov(result, Operand(result, StandardFrameConstants::kContextOffset));
    __ cmp(Operand(result),
           Immediate(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
    __ j(equal, &adapted, Label::kNear);

    // No arguments adaptor frame.
    __ mov(result, Operand(ebp));
    __ jmp(&done, Label::kNear);

    // Arguments adaptor frame present.
    __ bind(&adapted);
    __ mov(result, Operand(ebp, StandardFrameConstants::kCallerFPOffset));

    // Result is the frame pointer for the frame if not adapted and for the real
    // frame below the adaptor frame if adapted.
    __ bind(&done);
  }
}


void LCodeGen::DoArgumentsLength(LArgumentsLength* instr) {
  Operand elem = ToOperand(instr->elements());
  Register result = ToRegister(instr->result());

  Label done;

  // If no arguments adaptor frame the number of arguments is fixed.
  __ cmp(ebp, elem);
  __ mov(result, Immediate(scope()->num_parameters()));
  __ j(equal, &done, Label::kNear);

  // Arguments adaptor frame present. Get argument length from there.
  __ mov(result, Operand(ebp, StandardFrameConstants::kCallerFPOffset));
  __ mov(result, Operand(result,
                         ArgumentsAdaptorFrameConstants::kLengthOffset));
  __ SmiUntag(result);

  // Argument length is in result register.
  __ bind(&done);
}


void LCodeGen::DoWrapReceiver(LWrapReceiver* instr) {
  Register receiver = ToRegister(instr->receiver());
  Register function = ToRegister(instr->function());
  Register scratch = ToRegister(instr->temp());

  // If the receiver is null or undefined, we have to pass the global
  // object as a receiver to normal functions. Values have to be
  // passed unchanged to builtins and strict-mode functions.
  Label global_object, receiver_ok;

  // Do not transform the receiver to object for strict mode
  // functions.
  __ mov(scratch,
         FieldOperand(function, JSFunction::kSharedFunctionInfoOffset));
  __ test_b(FieldOperand(scratch, SharedFunctionInfo::kStrictModeByteOffset),
            1 << SharedFunctionInfo::kStrictModeBitWithinByte);
  __ j(not_equal, &receiver_ok);  // A near jump is not sufficient here!

  // Do not transform the receiver to object for builtins.
  __ test_b(FieldOperand(scratch, SharedFunctionInfo::kNativeByteOffset),
            1 << SharedFunctionInfo::kNativeBitWithinByte);
  __ j(not_equal, &receiver_ok);

  // Normal function. Replace undefined or null with global receiver.
  __ cmp(receiver, factory()->null_value());
  __ j(equal, &global_object, Label::kNear);
  __ cmp(receiver, factory()->undefined_value());
  __ j(equal, &global_object, Label::kNear);

  // The receiver should be a JS object.
  __ test(receiver, Immediate(kSmiTagMask));
  DeoptimizeIf(equal, instr->environment());
  __ CmpObjectType(receiver, FIRST_SPEC_OBJECT_TYPE, scratch);
  DeoptimizeIf(below, instr->environment());
  __ jmp(&receiver_ok, Label::kNear);

  __ bind(&global_object);
  // TODO(kmillikin): We have a hydrogen value for the global object.  See
  // if it's better to use it than to explicitly fetch it from the context
  // here.
  __ mov(receiver, Operand(ebp, StandardFrameConstants::kContextOffset));
  __ mov(receiver, ContextOperand(receiver, Context::GLOBAL_OBJECT_INDEX));
  __ mov(receiver,
         FieldOperand(receiver, JSGlobalObject::kGlobalReceiverOffset));
  __ bind(&receiver_ok);
}


void LCodeGen::DoApplyArguments(LApplyArguments* instr) {
  Register receiver = ToRegister(instr->receiver());
  Register function = ToRegister(instr->function());
  Register length = ToRegister(instr->length());
  Register elements = ToRegister(instr->elements());
  ASSERT(receiver.is(eax));  // Used for parameter count.
  ASSERT(function.is(edi));  // Required by InvokeFunction.
  ASSERT(ToRegister(instr->result()).is(eax));

  // Copy the arguments to this function possibly from the
  // adaptor frame below it.
  const uint32_t kArgumentsLimit = 1 * KB;
  __ cmp(length, kArgumentsLimit);
  DeoptimizeIf(above, instr->environment());

  __ push(receiver);
  __ mov(receiver, length);

  // Loop through the arguments pushing them onto the execution
  // stack.
  Label invoke, loop;
  // length is a small non-negative integer, due to the test above.
  __ test(length, Operand(length));
  __ j(zero, &invoke, Label::kNear);
  __ bind(&loop);
  __ push(Operand(elements, length, times_pointer_size, 1 * kPointerSize));
  __ dec(length);
  __ j(not_zero, &loop);

  // Invoke the function.
  __ bind(&invoke);
  ASSERT(instr->HasPointerMap());
  LPointerMap* pointers = instr->pointer_map();
  RecordPosition(pointers->position());
  SafepointGenerator safepoint_generator(
      this, pointers, Safepoint::kLazyDeopt);
  ParameterCount actual(eax);
  __ InvokeFunction(function, actual, CALL_FUNCTION,
                    safepoint_generator, CALL_AS_METHOD);
}


void LCodeGen::DoDebugBreak(LDebugBreak* instr) {
  __ int3();
}


void LCodeGen::DoPushArgument(LPushArgument* instr) {
  LOperand* argument = instr->value();
  EmitPushTaggedOperand(argument);
}


void LCodeGen::DoDrop(LDrop* instr) {
  __ Drop(instr->count());
}


void LCodeGen::DoThisFunction(LThisFunction* instr) {
  Register result = ToRegister(instr->result());
  __ mov(result, Operand(ebp, JavaScriptFrameConstants::kFunctionOffset));
}


void LCodeGen::DoContext(LContext* instr) {
  Register result = ToRegister(instr->result());
  if (info()->IsOptimizing()) {
    __ mov(result, Operand(ebp, StandardFrameConstants::kContextOffset));
  } else {
    // If there is no frame, the context must be in esi.
    ASSERT(result.is(esi));
  }
}


void LCodeGen::DoOuterContext(LOuterContext* instr) {
  Register context = ToRegister(instr->context());
  Register result = ToRegister(instr->result());
  __ mov(result,
         Operand(context, Context::SlotOffset(Context::PREVIOUS_INDEX)));
}


void LCodeGen::DoDeclareGlobals(LDeclareGlobals* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  __ push(esi);  // The context is the first argument.
  __ push(Immediate(instr->hydrogen()->pairs()));
  __ push(Immediate(Smi::FromInt(instr->hydrogen()->flags())));
  CallRuntime(Runtime::kDeclareGlobals, 3, instr);
}


void LCodeGen::DoGlobalObject(LGlobalObject* instr) {
  Register context = ToRegister(instr->context());
  Register result = ToRegister(instr->result());
  __ mov(result,
         Operand(context, Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)));
}


void LCodeGen::DoGlobalReceiver(LGlobalReceiver* instr) {
  Register global = ToRegister(instr->global());
  Register result = ToRegister(instr->result());
  __ mov(result, FieldOperand(global, GlobalObject::kGlobalReceiverOffset));
}


void LCodeGen::CallKnownFunction(Handle<JSFunction> function,
                                 int formal_parameter_count,
                                 int arity,
                                 LInstruction* instr,
                                 CallKind call_kind,
                                 EDIState edi_state) {
  bool dont_adapt_arguments =
      formal_parameter_count == SharedFunctionInfo::kDontAdaptArgumentsSentinel;
  bool can_invoke_directly =
      dont_adapt_arguments || formal_parameter_count == arity;

  LPointerMap* pointers = instr->pointer_map();
  RecordPosition(pointers->position());

  if (can_invoke_directly) {
    if (edi_state == EDI_UNINITIALIZED) {
      __ LoadHeapObject(edi, function);
    }

    // Change context.
    __ mov(esi, FieldOperand(edi, JSFunction::kContextOffset));

    // Set eax to arguments count if adaption is not needed. Assumes that eax
    // is available to write to at this point.
    if (dont_adapt_arguments) {
      __ mov(eax, arity);
    }

    // Invoke function directly.
    __ SetCallKind(ecx, call_kind);
    if (function.is_identical_to(info()->closure())) {
      __ CallSelf();
    } else {
      __ call(FieldOperand(edi, JSFunction::kCodeEntryOffset));
    }
    RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
  } else {
    // We need to adapt arguments.
    SafepointGenerator generator(
        this, pointers, Safepoint::kLazyDeopt);
    ParameterCount count(arity);
    ParameterCount expected(formal_parameter_count);
    __ InvokeFunction(
        function, expected, count, CALL_FUNCTION, generator, call_kind);
  }
}


void LCodeGen::DoCallConstantFunction(LCallConstantFunction* instr) {
  ASSERT(ToRegister(instr->result()).is(eax));
  CallKnownFunction(instr->hydrogen()->function(),
                    instr->hydrogen()->formal_parameter_count(),
                    instr->arity(),
                    instr,
                    CALL_AS_METHOD,
                    EDI_UNINITIALIZED);
}


void LCodeGen::DoDeferredMathAbsTaggedHeapNumber(LMathAbs* instr) {
  Register input_reg = ToRegister(instr->value());
  __ cmp(FieldOperand(input_reg, HeapObject::kMapOffset),
         factory()->heap_number_map());
  DeoptimizeIf(not_equal, instr->environment());

  Label done;
  Register tmp = input_reg.is(eax) ? ecx : eax;
  Register tmp2 = tmp.is(ecx) ? edx : input_reg.is(ecx) ? edx : ecx;

  // Preserve the value of all registers.
  PushSafepointRegistersScope scope(this);

  Label negative;
  __ mov(tmp, FieldOperand(input_reg, HeapNumber::kExponentOffset));
  // Check the sign of the argument. If the argument is positive, just
  // return it. We do not need to patch the stack since |input| and
  // |result| are the same register and |input| will be restored
  // unchanged by popping safepoint registers.
  __ test(tmp, Immediate(HeapNumber::kSignMask));
  __ j(not_zero, &negative);
  __ jmp(&done);

  __ bind(&negative);

  Label allocated, slow;
  __ AllocateHeapNumber(tmp, tmp2, no_reg, &slow);
  __ jmp(&allocated);

  // Slow case: Call the runtime system to do the number allocation.
  __ bind(&slow);

  CallRuntimeFromDeferred(Runtime::kAllocateHeapNumber, 0,
                          instr, instr->context());

  // Set the pointer to the new heap number in tmp.
  if (!tmp.is(eax)) __ mov(tmp, eax);

  // Restore input_reg after call to runtime.
  __ LoadFromSafepointRegisterSlot(input_reg, input_reg);

  __ bind(&allocated);
  __ mov(tmp2, FieldOperand(input_reg, HeapNumber::kExponentOffset));
  __ and_(tmp2, ~HeapNumber::kSignMask);
  __ mov(FieldOperand(tmp, HeapNumber::kExponentOffset), tmp2);
  __ mov(tmp2, FieldOperand(input_reg, HeapNumber::kMantissaOffset));
  __ mov(FieldOperand(tmp, HeapNumber::kMantissaOffset), tmp2);
  __ StoreToSafepointRegisterSlot(input_reg, tmp);

  __ bind(&done);
}


void LCodeGen::EmitIntegerMathAbs(LMathAbs* instr) {
  Register input_reg = ToRegister(instr->value());
  __ test(input_reg, Operand(input_reg));
  Label is_positive;
  __ j(not_sign, &is_positive);
  __ neg(input_reg);
  __ test(input_reg, Operand(input_reg));
  DeoptimizeIf(negative, instr->environment());
  __ bind(&is_positive);
}


void LCodeGen::DoMathAbs(LMathAbs* instr) {
  // Class for deferred case.
  class DeferredMathAbsTaggedHeapNumber: public LDeferredCode {
   public:
    DeferredMathAbsTaggedHeapNumber(LCodeGen* codegen, LMathAbs* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() {
      codegen()->DoDeferredMathAbsTaggedHeapNumber(instr_);
    }
    virtual LInstruction* instr() { return instr_; }
   private:
    LMathAbs* instr_;
  };

  ASSERT(instr->value()->Equals(instr->result()));
  Representation r = instr->hydrogen()->value()->representation();

  CpuFeatureScope scope(masm(), SSE2);
  if (r.IsDouble()) {
    XMMRegister  scratch = xmm0;
    XMMRegister input_reg = ToDoubleRegister(instr->value());
    __ xorps(scratch, scratch);
    __ subsd(scratch, input_reg);
    __ pand(input_reg, scratch);
  } else if (r.IsInteger32()) {
    EmitIntegerMathAbs(instr);
  } else {  // Tagged case.
    DeferredMathAbsTaggedHeapNumber* deferred =
        new(zone()) DeferredMathAbsTaggedHeapNumber(this, instr);
    Register input_reg = ToRegister(instr->value());
    // Smi check.
    __ JumpIfNotSmi(input_reg, deferred->entry());
    EmitIntegerMathAbs(instr);
    __ bind(deferred->exit());
  }
}


void LCodeGen::DoMathFloor(LMathFloor* instr) {
  CpuFeatureScope scope(masm(), SSE2);
  XMMRegister xmm_scratch = xmm0;
  Register output_reg = ToRegister(instr->result());
  XMMRegister input_reg = ToDoubleRegister(instr->value());

  if (CpuFeatures::IsSupported(SSE4_1)) {
    CpuFeatureScope scope(masm(), SSE4_1);
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      // Deoptimize on negative zero.
      Label non_zero;
      __ xorps(xmm_scratch, xmm_scratch);  // Zero the register.
      __ ucomisd(input_reg, xmm_scratch);
      __ j(not_equal, &non_zero, Label::kNear);
      __ movmskpd(output_reg, input_reg);
      __ test(output_reg, Immediate(1));
      DeoptimizeIf(not_zero, instr->environment());
      __ bind(&non_zero);
    }
    __ roundsd(xmm_scratch, input_reg, Assembler::kRoundDown);
    __ cvttsd2si(output_reg, Operand(xmm_scratch));
    // Overflow is signalled with minint.
    __ cmp(output_reg, 0x80000000u);
    DeoptimizeIf(equal, instr->environment());
  } else {
    Label negative_sign, done;
    // Deoptimize on unordered.
    __ xorps(xmm_scratch, xmm_scratch);  // Zero the register.
    __ ucomisd(input_reg, xmm_scratch);
    DeoptimizeIf(parity_even, instr->environment());
    __ j(below, &negative_sign, Label::kNear);

    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      // Check for negative zero.
      Label positive_sign;
      __ j(above, &positive_sign, Label::kNear);
      __ movmskpd(output_reg, input_reg);
      __ test(output_reg, Immediate(1));
      DeoptimizeIf(not_zero, instr->environment());
      __ Set(output_reg, Immediate(0));
      __ jmp(&done, Label::kNear);
      __ bind(&positive_sign);
    }

    // Use truncating instruction (OK because input is positive).
    __ cvttsd2si(output_reg, Operand(input_reg));
    // Overflow is signalled with minint.
    __ cmp(output_reg, 0x80000000u);
    DeoptimizeIf(equal, instr->environment());
    __ jmp(&done, Label::kNear);

    // Non-zero negative reaches here.
    __ bind(&negative_sign);
    // Truncate, then compare and compensate.
    __ cvttsd2si(output_reg, Operand(input_reg));
    __ cvtsi2sd(xmm_scratch, output_reg);
    __ ucomisd(input_reg, xmm_scratch);
    __ j(equal, &done, Label::kNear);
    __ sub(output_reg, Immediate(1));
    DeoptimizeIf(overflow, instr->environment());

    __ bind(&done);
  }
}

void LCodeGen::DoMathRound(LMathRound* instr) {
  CpuFeatureScope scope(masm(), SSE2);
  Register output_reg = ToRegister(instr->result());
  XMMRegister input_reg = ToDoubleRegister(instr->value());
  XMMRegister xmm_scratch = xmm0;
  XMMRegister input_temp = ToDoubleRegister(instr->temp());
  ExternalReference one_half = ExternalReference::address_of_one_half();
  ExternalReference minus_one_half =
      ExternalReference::address_of_minus_one_half();

  Label done, round_to_zero, below_one_half, do_not_compensate;
  __ movdbl(xmm_scratch, Operand::StaticVariable(one_half));
  __ ucomisd(xmm_scratch, input_reg);
  __ j(above, &below_one_half);

  // CVTTSD2SI rounds towards zero, since 0.5 <= x, we use floor(0.5 + x).
  __ addsd(xmm_scratch, input_reg);
  __ cvttsd2si(output_reg, Operand(xmm_scratch));
  // Overflow is signalled with minint.
  __ cmp(output_reg, 0x80000000u);
  __ RecordComment("D2I conversion overflow");
  DeoptimizeIf(equal, instr->environment());
  __ jmp(&done);

  __ bind(&below_one_half);
  __ movdbl(xmm_scratch, Operand::StaticVariable(minus_one_half));
  __ ucomisd(xmm_scratch, input_reg);
  __ j(below_equal, &round_to_zero);

  // CVTTSD2SI rounds towards zero, we use ceil(x - (-0.5)) and then
  // compare and compensate.
  __ movsd(input_temp, input_reg);  // Do not alter input_reg.
  __ subsd(input_temp, xmm_scratch);
  __ cvttsd2si(output_reg, Operand(input_temp));
  // Catch minint due to overflow, and to prevent overflow when compensating.
  __ cmp(output_reg, 0x80000000u);
  __ RecordComment("D2I conversion overflow");
  DeoptimizeIf(equal, instr->environment());

  __ cvtsi2sd(xmm_scratch, output_reg);
  __ ucomisd(xmm_scratch, input_temp);
  __ j(equal, &done);
  __ sub(output_reg, Immediate(1));
  // No overflow because we already ruled out minint.
  __ jmp(&done);

  __ bind(&round_to_zero);
  // We return 0 for the input range [+0, 0.5[, or [-0.5, 0.5[ if
  // we can ignore the difference between a result of -0 and +0.
  if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
    // If the sign is positive, we return +0.
    __ movmskpd(output_reg, input_reg);
    __ test(output_reg, Immediate(1));
    __ RecordComment("Minus zero");
    DeoptimizeIf(not_zero, instr->environment());
  }
  __ Set(output_reg, Immediate(0));
  __ bind(&done);
}


void LCodeGen::DoMathSqrt(LMathSqrt* instr) {
  CpuFeatureScope scope(masm(), SSE2);
  XMMRegister input_reg = ToDoubleRegister(instr->value());
  ASSERT(ToDoubleRegister(instr->result()).is(input_reg));
  __ sqrtsd(input_reg, input_reg);
}


void LCodeGen::DoMathPowHalf(LMathPowHalf* instr) {
  CpuFeatureScope scope(masm(), SSE2);
  XMMRegister xmm_scratch = xmm0;
  XMMRegister input_reg = ToDoubleRegister(instr->value());
  Register scratch = ToRegister(instr->temp());
  ASSERT(ToDoubleRegister(instr->result()).is(input_reg));

  // Note that according to ECMA-262 15.8.2.13:
  // Math.pow(-Infinity, 0.5) == Infinity
  // Math.sqrt(-Infinity) == NaN
  Label done, sqrt;
  // Check base for -Infinity.  According to IEEE-754, single-precision
  // -Infinity has the highest 9 bits set and the lowest 23 bits cleared.
  __ mov(scratch, 0xFF800000);
  __ movd(xmm_scratch, scratch);
  __ cvtss2sd(xmm_scratch, xmm_scratch);
  __ ucomisd(input_reg, xmm_scratch);
  // Comparing -Infinity with NaN results in "unordered", which sets the
  // zero flag as if both were equal.  However, it also sets the carry flag.
  __ j(not_equal, &sqrt, Label::kNear);
  __ j(carry, &sqrt, Label::kNear);
  // If input is -Infinity, return Infinity.
  __ xorps(input_reg, input_reg);
  __ subsd(input_reg, xmm_scratch);
  __ jmp(&done, Label::kNear);

  // Square root.
  __ bind(&sqrt);
  __ xorps(xmm_scratch, xmm_scratch);
  __ addsd(input_reg, xmm_scratch);  // Convert -0 to +0.
  __ sqrtsd(input_reg, input_reg);
  __ bind(&done);
}


void LCodeGen::DoPower(LPower* instr) {
  Representation exponent_type = instr->hydrogen()->right()->representation();
  // Having marked this as a call, we can use any registers.
  // Just make sure that the input/output registers are the expected ones.
  ASSERT(!instr->right()->IsDoubleRegister() ||
         ToDoubleRegister(instr->right()).is(xmm1));
  ASSERT(!instr->right()->IsRegister() ||
         ToRegister(instr->right()).is(eax));
  ASSERT(ToDoubleRegister(instr->left()).is(xmm2));
  ASSERT(ToDoubleRegister(instr->result()).is(xmm3));

  if (exponent_type.IsSmi()) {
    MathPowStub stub(MathPowStub::TAGGED);
    __ CallStub(&stub);
  } else if (exponent_type.IsTagged()) {
    Label no_deopt;
    __ JumpIfSmi(eax, &no_deopt);
    __ CmpObjectType(eax, HEAP_NUMBER_TYPE, ecx);
    DeoptimizeIf(not_equal, instr->environment());
    __ bind(&no_deopt);
    MathPowStub stub(MathPowStub::TAGGED);
    __ CallStub(&stub);
  } else if (exponent_type.IsInteger32()) {
    MathPowStub stub(MathPowStub::INTEGER);
    __ CallStub(&stub);
  } else {
    ASSERT(exponent_type.IsDouble());
    MathPowStub stub(MathPowStub::DOUBLE);
    __ CallStub(&stub);
  }
}


void LCodeGen::DoRandom(LRandom* instr) {
  class DeferredDoRandom: public LDeferredCode {
   public:
    DeferredDoRandom(LCodeGen* codegen, LRandom* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() { codegen()->DoDeferredRandom(instr_); }
    virtual LInstruction* instr() { return instr_; }
   private:
    LRandom* instr_;
  };

  DeferredDoRandom* deferred = new(zone()) DeferredDoRandom(this, instr);

  CpuFeatureScope scope(masm(), SSE2);
  // Having marked this instruction as a call we can use any
  // registers.
  ASSERT(ToDoubleRegister(instr->result()).is(xmm1));
  ASSERT(ToRegister(instr->global_object()).is(eax));
  // Assert that the register size is indeed the size of each seed.
  static const int kSeedSize = sizeof(uint32_t);
  STATIC_ASSERT(kPointerSize == kSeedSize);

  __ mov(eax, FieldOperand(eax, GlobalObject::kNativeContextOffset));
  static const int kRandomSeedOffset =
      FixedArray::kHeaderSize + Context::RANDOM_SEED_INDEX * kPointerSize;
  __ mov(ebx, FieldOperand(eax, kRandomSeedOffset));
  // ebx: FixedArray of the native context's random seeds

  // Load state[0].
  __ mov(ecx, FieldOperand(ebx, ByteArray::kHeaderSize));
  // If state[0] == 0, call runtime to initialize seeds.
  __ test(ecx, ecx);
  __ j(zero, deferred->entry());
  // Load state[1].
  __ mov(eax, FieldOperand(ebx, ByteArray::kHeaderSize + kSeedSize));
  // ecx: state[0]
  // eax: state[1]

  // state[0] = 18273 * (state[0] & 0xFFFF) + (state[0] >> 16)
  __ movzx_w(edx, ecx);
  __ imul(edx, edx, 18273);
  __ shr(ecx, 16);
  __ add(ecx, edx);
  // Save state[0].
  __ mov(FieldOperand(ebx, ByteArray::kHeaderSize), ecx);

  // state[1] = 36969 * (state[1] & 0xFFFF) + (state[1] >> 16)
  __ movzx_w(edx, eax);
  __ imul(edx, edx, 36969);
  __ shr(eax, 16);
  __ add(eax, edx);
  // Save state[1].
  __ mov(FieldOperand(ebx, ByteArray::kHeaderSize + kSeedSize), eax);

  // Random bit pattern = (state[0] << 14) + (state[1] & 0x3FFFF)
  __ shl(ecx, 14);
  __ and_(eax, Immediate(0x3FFFF));
  __ add(eax, ecx);

  __ bind(deferred->exit());
  // Convert 32 random bits in eax to 0.(32 random bits) in a double
  // by computing:
  // ( 1.(20 0s)(32 random bits) x 2^20 ) - (1.0 x 2^20)).
  __ mov(ebx, Immediate(0x49800000));  // 1.0 x 2^20 as single.
  __ movd(xmm2, ebx);
  __ movd(xmm1, eax);
  __ cvtss2sd(xmm2, xmm2);
  __ xorps(xmm1, xmm2);
  __ subsd(xmm1, xmm2);
}


void LCodeGen::DoDeferredRandom(LRandom* instr) {
  __ PrepareCallCFunction(1, ebx);
  __ mov(Operand(esp, 0), eax);
  __ CallCFunction(ExternalReference::random_uint32_function(isolate()), 1);
  // Return value is in eax.
}


void LCodeGen::DoMathLog(LMathLog* instr) {
  CpuFeatureScope scope(masm(), SSE2);
  ASSERT(instr->value()->Equals(instr->result()));
  XMMRegister input_reg = ToDoubleRegister(instr->value());
  Label positive, done, zero;
  __ xorps(xmm0, xmm0);
  __ ucomisd(input_reg, xmm0);
  __ j(above, &positive, Label::kNear);
  __ j(equal, &zero, Label::kNear);
  ExternalReference nan =
      ExternalReference::address_of_canonical_non_hole_nan();
  __ movdbl(input_reg, Operand::StaticVariable(nan));
  __ jmp(&done, Label::kNear);
  __ bind(&zero);
  __ push(Immediate(0xFFF00000));
  __ push(Immediate(0));
  __ movdbl(input_reg, Operand(esp, 0));
  __ add(Operand(esp), Immediate(kDoubleSize));
  __ jmp(&done, Label::kNear);
  __ bind(&positive);
  __ fldln2();
  __ sub(Operand(esp), Immediate(kDoubleSize));
  __ movdbl(Operand(esp, 0), input_reg);
  __ fld_d(Operand(esp, 0));
  __ fyl2x();
  __ fstp_d(Operand(esp, 0));
  __ movdbl(input_reg, Operand(esp, 0));
  __ add(Operand(esp), Immediate(kDoubleSize));
  __ bind(&done);
}


void LCodeGen::DoMathExp(LMathExp* instr) {
  CpuFeatureScope scope(masm(), SSE2);
  XMMRegister input = ToDoubleRegister(instr->value());
  XMMRegister result = ToDoubleRegister(instr->result());
  Register temp1 = ToRegister(instr->temp1());
  Register temp2 = ToRegister(instr->temp2());

  MathExpGenerator::EmitMathExp(masm(), input, result, xmm0, temp1, temp2);
}


void LCodeGen::DoMathTan(LMathTan* instr) {
  ASSERT(ToDoubleRegister(instr->result()).is(xmm1));
  TranscendentalCacheStub stub(TranscendentalCache::TAN,
                               TranscendentalCacheStub::UNTAGGED);
  CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
}


void LCodeGen::DoMathCos(LMathCos* instr) {
  ASSERT(ToDoubleRegister(instr->result()).is(xmm1));
  TranscendentalCacheStub stub(TranscendentalCache::COS,
                               TranscendentalCacheStub::UNTAGGED);
  CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
}


void LCodeGen::DoMathSin(LMathSin* instr) {
  ASSERT(ToDoubleRegister(instr->result()).is(xmm1));
  TranscendentalCacheStub stub(TranscendentalCache::SIN,
                               TranscendentalCacheStub::UNTAGGED);
  CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
}


void LCodeGen::DoInvokeFunction(LInvokeFunction* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  ASSERT(ToRegister(instr->function()).is(edi));
  ASSERT(instr->HasPointerMap());

  Handle<JSFunction> known_function = instr->hydrogen()->known_function();
  if (known_function.is_null()) {
    LPointerMap* pointers = instr->pointer_map();
    RecordPosition(pointers->position());
    SafepointGenerator generator(
        this, pointers, Safepoint::kLazyDeopt);
    ParameterCount count(instr->arity());
    __ InvokeFunction(edi, count, CALL_FUNCTION, generator, CALL_AS_METHOD);
  } else {
    CallKnownFunction(known_function,
                      instr->hydrogen()->formal_parameter_count(),
                      instr->arity(),
                      instr,
                      CALL_AS_METHOD,
                      EDI_CONTAINS_TARGET);
  }
}


void LCodeGen::DoCallKeyed(LCallKeyed* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  ASSERT(ToRegister(instr->key()).is(ecx));
  ASSERT(ToRegister(instr->result()).is(eax));

  int arity = instr->arity();
  Handle<Code> ic =
      isolate()->stub_cache()->ComputeKeyedCallInitialize(arity);
  CallCode(ic, RelocInfo::CODE_TARGET, instr);
}


void LCodeGen::DoCallNamed(LCallNamed* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  ASSERT(ToRegister(instr->result()).is(eax));

  int arity = instr->arity();
  RelocInfo::Mode mode = RelocInfo::CODE_TARGET;
  Handle<Code> ic =
      isolate()->stub_cache()->ComputeCallInitialize(arity, mode);
  __ mov(ecx, instr->name());
  CallCode(ic, mode, instr);
}


void LCodeGen::DoCallFunction(LCallFunction* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  ASSERT(ToRegister(instr->function()).is(edi));
  ASSERT(ToRegister(instr->result()).is(eax));

  int arity = instr->arity();
  CallFunctionStub stub(arity, NO_CALL_FUNCTION_FLAGS);
  CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
}


void LCodeGen::DoCallGlobal(LCallGlobal* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  ASSERT(ToRegister(instr->result()).is(eax));

  int arity = instr->arity();
  RelocInfo::Mode mode = RelocInfo::CODE_TARGET_CONTEXT;
  Handle<Code> ic =
      isolate()->stub_cache()->ComputeCallInitialize(arity, mode);
  __ mov(ecx, instr->name());
  CallCode(ic, mode, instr);
}


void LCodeGen::DoCallKnownGlobal(LCallKnownGlobal* instr) {
  ASSERT(ToRegister(instr->result()).is(eax));
  CallKnownFunction(instr->hydrogen()->target(),
                    instr->hydrogen()->formal_parameter_count(),
                    instr->arity(),
                    instr,
                    CALL_AS_FUNCTION,
                    EDI_UNINITIALIZED);
}


void LCodeGen::DoCallNew(LCallNew* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  ASSERT(ToRegister(instr->constructor()).is(edi));
  ASSERT(ToRegister(instr->result()).is(eax));

  if (FLAG_optimize_constructed_arrays) {
    // No cell in ebx for construct type feedback in optimized code
    Handle<Object> undefined_value(isolate()->heap()->undefined_value(),
                                   isolate());
    __ mov(ebx, Immediate(undefined_value));
  }
  CallConstructStub stub(NO_CALL_FUNCTION_FLAGS);
  __ Set(eax, Immediate(instr->arity()));
  CallCode(stub.GetCode(isolate()), RelocInfo::CONSTRUCT_CALL, instr);
}


void LCodeGen::DoCallNewArray(LCallNewArray* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  ASSERT(ToRegister(instr->constructor()).is(edi));
  ASSERT(ToRegister(instr->result()).is(eax));
  ASSERT(FLAG_optimize_constructed_arrays);

  __ Set(eax, Immediate(instr->arity()));
  __ mov(ebx, instr->hydrogen()->property_cell());
  ElementsKind kind = instr->hydrogen()->elements_kind();
  bool disable_allocation_sites =
      (AllocationSiteInfo::GetMode(kind) == TRACK_ALLOCATION_SITE);

  if (instr->arity() == 0) {
    ArrayNoArgumentConstructorStub stub(kind, disable_allocation_sites);
    CallCode(stub.GetCode(isolate()), RelocInfo::CONSTRUCT_CALL, instr);
  } else if (instr->arity() == 1) {
    ArraySingleArgumentConstructorStub stub(kind, disable_allocation_sites);
    CallCode(stub.GetCode(isolate()), RelocInfo::CONSTRUCT_CALL, instr);
  } else {
    ArrayNArgumentsConstructorStub stub(kind, disable_allocation_sites);
    CallCode(stub.GetCode(isolate()), RelocInfo::CONSTRUCT_CALL, instr);
  }
}


void LCodeGen::DoCallRuntime(LCallRuntime* instr) {
  CallRuntime(instr->function(), instr->arity(), instr);
}


void LCodeGen::DoInnerAllocatedObject(LInnerAllocatedObject* instr) {
  Register result = ToRegister(instr->result());
  Register base = ToRegister(instr->base_object());
  __ lea(result, Operand(base, instr->offset()));
}


void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
  Representation representation = instr->representation();

  Register object = ToRegister(instr->object());
  HObjectAccess access = instr->hydrogen()->access();
  int offset = access.offset();

  Handle<Map> transition = instr->transition();

  if (FLAG_track_fields && representation.IsSmi()) {
    if (instr->value()->IsConstantOperand()) {
      LConstantOperand* operand_value = LConstantOperand::cast(instr->value());
      if (!IsSmi(operand_value)) {
        DeoptimizeIf(no_condition, instr->environment());
      }
    }
  } else if (FLAG_track_heap_object_fields && representation.IsHeapObject()) {
    if (instr->value()->IsConstantOperand()) {
      LConstantOperand* operand_value = LConstantOperand::cast(instr->value());
      if (IsInteger32(operand_value)) {
        DeoptimizeIf(no_condition, instr->environment());
      }
    } else {
      if (!instr->hydrogen()->value()->type().IsHeapObject()) {
        Register value = ToRegister(instr->value());
        __ test(value, Immediate(kSmiTagMask));
        DeoptimizeIf(zero, instr->environment());
      }
    }
  } else if (FLAG_track_double_fields && representation.IsDouble()) {
    ASSERT(transition.is_null());
    ASSERT(access.IsInobject());
    ASSERT(!instr->hydrogen()->NeedsWriteBarrier());
    if (CpuFeatures::IsSupported(SSE2)) {
      CpuFeatureScope scope(masm(), SSE2);
      XMMRegister value = ToDoubleRegister(instr->value());
      __ movdbl(FieldOperand(object, offset), value);
    } else {
      __ fstp_d(FieldOperand(object, offset));
    }
    return;
  }

  if (!transition.is_null()) {
    if (transition->CanBeDeprecated()) {
      transition_maps_.Add(transition, info()->zone());
    }
    if (!instr->hydrogen()->NeedsWriteBarrierForMap()) {
      __ mov(FieldOperand(object, HeapObject::kMapOffset), transition);
    } else {
      Register temp = ToRegister(instr->temp());
      Register temp_map = ToRegister(instr->temp_map());
      __ mov(temp_map, transition);
      __ mov(FieldOperand(object, HeapObject::kMapOffset), temp_map);
      // Update the write barrier for the map field.
      __ RecordWriteField(object,
                          HeapObject::kMapOffset,
                          temp_map,
                          temp,
                          GetSaveFPRegsMode(),
                          OMIT_REMEMBERED_SET,
                          OMIT_SMI_CHECK);
    }
  }

  // Do the store.
  HType type = instr->hydrogen()->value()->type();
  SmiCheck check_needed =
      type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;

  Register write_register = object;
  if (!access.IsInobject()) {
    write_register = ToRegister(instr->temp());
    __ mov(write_register,
           FieldOperand(object, JSObject::kPropertiesOffset));
  }

  if (instr->value()->IsConstantOperand()) {
    LConstantOperand* operand_value = LConstantOperand::cast(instr->value());
    if (operand_value->IsRegister()) {
      __ mov(FieldOperand(write_register, offset), ToRegister(operand_value));
    } else {
      Handle<Object> handle_value = ToHandle(operand_value);
      ASSERT(!instr->hydrogen()->NeedsWriteBarrier());
      __ mov(FieldOperand(write_register, offset), handle_value);
    }
  } else {
    __ mov(FieldOperand(write_register, offset), ToRegister(instr->value()));
  }

  if (instr->hydrogen()->NeedsWriteBarrier()) {
    Register value = ToRegister(instr->value());
    Register temp = access.IsInobject() ? ToRegister(instr->temp()) : object;
    // Update the write barrier for the object for in-object properties.
    __ RecordWriteField(write_register,
                        offset,
                        value,
                        temp,
                        GetSaveFPRegsMode(),
                        EMIT_REMEMBERED_SET,
                        check_needed);
  }
}


void LCodeGen::DoStoreNamedGeneric(LStoreNamedGeneric* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  ASSERT(ToRegister(instr->object()).is(edx));
  ASSERT(ToRegister(instr->value()).is(eax));

  __ mov(ecx, instr->name());
  Handle<Code> ic = (instr->strict_mode_flag() == kStrictMode)
      ? isolate()->builtins()->StoreIC_Initialize_Strict()
      : isolate()->builtins()->StoreIC_Initialize();
  CallCode(ic, RelocInfo::CODE_TARGET, instr);
}


void LCodeGen::DoBoundsCheck(LBoundsCheck* instr) {
  if (instr->hydrogen()->skip_check()) return;

  if (instr->index()->IsConstantOperand()) {
    int constant_index =
        ToInteger32(LConstantOperand::cast(instr->index()));
    if (instr->hydrogen()->length()->representation().IsSmi()) {
      __ cmp(ToOperand(instr->length()),
             Immediate(Smi::FromInt(constant_index)));
    } else {
      __ cmp(ToOperand(instr->length()), Immediate(constant_index));
    }
    DeoptimizeIf(below_equal, instr->environment());
  } else {
    __ cmp(ToRegister(instr->index()), ToOperand(instr->length()));
    DeoptimizeIf(above_equal, instr->environment());
  }
}


void LCodeGen::DoStoreKeyedExternalArray(LStoreKeyed* instr) {
  ElementsKind elements_kind = instr->elements_kind();
  LOperand* key = instr->key();
  if (!key->IsConstantOperand() &&
      ExternalArrayOpRequiresTemp(instr->hydrogen()->key()->representation(),
                                  elements_kind)) {
    __ SmiUntag(ToRegister(key));
  }
  Operand operand(BuildFastArrayOperand(
      instr->elements(),
      key,
      instr->hydrogen()->key()->representation(),
      elements_kind,
      0,
      instr->additional_index()));
  if (elements_kind == EXTERNAL_FLOAT_ELEMENTS) {
    if (CpuFeatures::IsSafeForSnapshot(SSE2)) {
      CpuFeatureScope scope(masm(), SSE2);
      __ cvtsd2ss(xmm0, ToDoubleRegister(instr->value()));
      __ movss(operand, xmm0);
    } else {
      __ fld(0);
      __ fstp_s(operand);
    }
  } else if (elements_kind == EXTERNAL_DOUBLE_ELEMENTS) {
    if (CpuFeatures::IsSafeForSnapshot(SSE2)) {
      CpuFeatureScope scope(masm(), SSE2);
      __ movdbl(operand, ToDoubleRegister(instr->value()));
    } else {
      __ fst_d(operand);
    }
  } else {
    Register value = ToRegister(instr->value());
    switch (elements_kind) {
      case EXTERNAL_PIXEL_ELEMENTS:
      case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
      case EXTERNAL_BYTE_ELEMENTS:
        __ mov_b(operand, value);
        break;
      case EXTERNAL_SHORT_ELEMENTS:
      case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
        __ mov_w(operand, value);
        break;
      case EXTERNAL_INT_ELEMENTS:
      case EXTERNAL_UNSIGNED_INT_ELEMENTS:
        __ mov(operand, value);
        break;
      case EXTERNAL_FLOAT_ELEMENTS:
      case EXTERNAL_DOUBLE_ELEMENTS:
      case FAST_SMI_ELEMENTS:
      case FAST_ELEMENTS:
      case FAST_DOUBLE_ELEMENTS:
      case FAST_HOLEY_SMI_ELEMENTS:
      case FAST_HOLEY_ELEMENTS:
      case FAST_HOLEY_DOUBLE_ELEMENTS:
      case DICTIONARY_ELEMENTS:
      case NON_STRICT_ARGUMENTS_ELEMENTS:
        UNREACHABLE();
        break;
    }
  }
}


void LCodeGen::DoStoreKeyedFixedDoubleArray(LStoreKeyed* instr) {
  ExternalReference canonical_nan_reference =
      ExternalReference::address_of_canonical_non_hole_nan();
  Operand double_store_operand = BuildFastArrayOperand(
      instr->elements(),
      instr->key(),
      instr->hydrogen()->key()->representation(),
      FAST_DOUBLE_ELEMENTS,
      FixedDoubleArray::kHeaderSize - kHeapObjectTag,
      instr->additional_index());

  if (CpuFeatures::IsSafeForSnapshot(SSE2)) {
    CpuFeatureScope scope(masm(), SSE2);
    XMMRegister value = ToDoubleRegister(instr->value());

    if (instr->NeedsCanonicalization()) {
      Label have_value;

      __ ucomisd(value, value);
      __ j(parity_odd, &have_value);  // NaN.

      __ movdbl(value, Operand::StaticVariable(canonical_nan_reference));
      __ bind(&have_value);
    }

    __ movdbl(double_store_operand, value);
  } else {
    // Can't use SSE2 in the serializer
    if (instr->hydrogen()->IsConstantHoleStore()) {
      // This means we should store the (double) hole. No floating point
      // registers required.
      double nan_double = FixedDoubleArray::hole_nan_as_double();
      uint64_t int_val = BitCast<uint64_t, double>(nan_double);
      int32_t lower = static_cast<int32_t>(int_val);
      int32_t upper = static_cast<int32_t>(int_val >> (kBitsPerInt));

      __ mov(double_store_operand, Immediate(lower));
      Operand double_store_operand2 = BuildFastArrayOperand(
          instr->elements(),
          instr->key(),
          instr->hydrogen()->key()->representation(),
          FAST_DOUBLE_ELEMENTS,
          FixedDoubleArray::kHeaderSize - kHeapObjectTag + kPointerSize,
          instr->additional_index());
      __ mov(double_store_operand2, Immediate(upper));
    } else {
      Label no_special_nan_handling;
      ASSERT(x87_stack_depth_ > 0);

      if (instr->NeedsCanonicalization()) {
        __ fld(0);
        __ fld(0);
        __ FCmp();

        __ j(parity_odd, &no_special_nan_handling);
        __ sub(esp, Immediate(kDoubleSize));
        __ fst_d(MemOperand(esp, 0));
        __ cmp(MemOperand(esp, sizeof(kHoleNanLower32)),
               Immediate(kHoleNanUpper32));
        __ add(esp, Immediate(kDoubleSize));
        Label canonicalize;
        __ j(not_equal, &canonicalize);
        __ jmp(&no_special_nan_handling);
        __ bind(&canonicalize);
        __ fstp(0);
        __ fld_d(Operand::StaticVariable(canonical_nan_reference));
      }

      __ bind(&no_special_nan_handling);
      __ fst_d(double_store_operand);
    }
  }
}


void LCodeGen::DoStoreKeyedFixedArray(LStoreKeyed* instr) {
  Register elements = ToRegister(instr->elements());
  Register key = instr->key()->IsRegister() ? ToRegister(instr->key()) : no_reg;

  Operand operand = BuildFastArrayOperand(
      instr->elements(),
      instr->key(),
      instr->hydrogen()->key()->representation(),
      FAST_ELEMENTS,
      FixedArray::kHeaderSize - kHeapObjectTag,
      instr->additional_index());
  if (instr->value()->IsRegister()) {
    __ mov(operand, ToRegister(instr->value()));
  } else {
    LConstantOperand* operand_value = LConstantOperand::cast(instr->value());
    if (IsInteger32(operand_value)) {
      Smi* smi_value = Smi::FromInt(ToInteger32(operand_value));
      __ mov(operand, Immediate(smi_value));
    } else {
      Handle<Object> handle_value = ToHandle(operand_value);
      __ mov(operand, handle_value);
    }
  }

  if (instr->hydrogen()->NeedsWriteBarrier()) {
    ASSERT(instr->value()->IsRegister());
    Register value = ToRegister(instr->value());
    ASSERT(!instr->key()->IsConstantOperand());
    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.
    __ lea(key, operand);
    __ RecordWrite(elements,
                   key,
                   value,
                   GetSaveFPRegsMode(),
                   EMIT_REMEMBERED_SET,
                   check_needed);
  }
}


void LCodeGen::DoStoreKeyed(LStoreKeyed* instr) {
  // By cases...external, fast-double, fast
  if (instr->is_external()) {
    DoStoreKeyedExternalArray(instr);
  } else if (instr->hydrogen()->value()->representation().IsDouble()) {
    DoStoreKeyedFixedDoubleArray(instr);
  } else {
    DoStoreKeyedFixedArray(instr);
  }
}


void LCodeGen::DoStoreKeyedGeneric(LStoreKeyedGeneric* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  ASSERT(ToRegister(instr->object()).is(edx));
  ASSERT(ToRegister(instr->key()).is(ecx));
  ASSERT(ToRegister(instr->value()).is(eax));

  Handle<Code> ic = (instr->strict_mode_flag() == kStrictMode)
      ? isolate()->builtins()->KeyedStoreIC_Initialize_Strict()
      : isolate()->builtins()->KeyedStoreIC_Initialize();
  CallCode(ic, RelocInfo::CODE_TARGET, instr);
}


void LCodeGen::DoTrapAllocationMemento(LTrapAllocationMemento* instr) {
  Register object = ToRegister(instr->object());
  Register temp = ToRegister(instr->temp());
  __ TestJSArrayForAllocationSiteInfo(object, temp);
  DeoptimizeIf(equal, instr->environment());
}


void LCodeGen::DoTransitionElementsKind(LTransitionElementsKind* instr) {
  Register object_reg = ToRegister(instr->object());

  Handle<Map> from_map = instr->original_map();
  Handle<Map> to_map = instr->transitioned_map();
  ElementsKind from_kind = instr->from_kind();
  ElementsKind to_kind = instr->to_kind();

  Label not_applicable;
  bool is_simple_map_transition =
      IsSimpleMapChangeTransition(from_kind, to_kind);
  Label::Distance branch_distance =
      is_simple_map_transition ? Label::kNear : Label::kFar;
  __ cmp(FieldOperand(object_reg, HeapObject::kMapOffset), from_map);
  __ j(not_equal, &not_applicable, branch_distance);
  if (is_simple_map_transition) {
    Register new_map_reg = ToRegister(instr->new_map_temp());
    Handle<Map> map = instr->hydrogen()->transitioned_map();
    __ mov(FieldOperand(object_reg, HeapObject::kMapOffset),
           Immediate(map));
    // Write barrier.
    ASSERT_NE(instr->temp(), NULL);
    __ RecordWriteForMap(object_reg, to_map, new_map_reg,
                         ToRegister(instr->temp()),
                         kDontSaveFPRegs);
  } else if (FLAG_compiled_transitions) {
    PushSafepointRegistersScope scope(this);
    if (!object_reg.is(eax)) {
      __ push(object_reg);
    }
    LoadContextFromDeferred(instr->context());
    if (!object_reg.is(eax)) {
      __ pop(eax);
    }
    __ mov(ebx, to_map);
    TransitionElementsKindStub stub(from_kind, to_kind);
    __ CallStub(&stub);
    RecordSafepointWithRegisters(
        instr->pointer_map(), 0, Safepoint::kNoLazyDeopt);
  } else if (IsFastSmiElementsKind(from_kind) &&
             IsFastDoubleElementsKind(to_kind)) {
    Register new_map_reg = ToRegister(instr->new_map_temp());
    __ mov(new_map_reg, to_map);
    Register fixed_object_reg = ToRegister(instr->temp());
    ASSERT(fixed_object_reg.is(edx));
    ASSERT(new_map_reg.is(ebx));
    __ mov(fixed_object_reg, object_reg);
    CallCode(isolate()->builtins()->TransitionElementsSmiToDouble(),
             RelocInfo::CODE_TARGET, instr);
  } else if (IsFastDoubleElementsKind(from_kind) &&
             IsFastObjectElementsKind(to_kind)) {
    Register new_map_reg = ToRegister(instr->new_map_temp());
    __ mov(new_map_reg, to_map);
    Register fixed_object_reg = ToRegister(instr->temp());
    ASSERT(fixed_object_reg.is(edx));
    ASSERT(new_map_reg.is(ebx));
    __ mov(fixed_object_reg, object_reg);
    CallCode(isolate()->builtins()->TransitionElementsDoubleToObject(),
             RelocInfo::CODE_TARGET, instr);
  } else {
    UNREACHABLE();
  }
  __ bind(&not_applicable);
}


void LCodeGen::DoStringCharCodeAt(LStringCharCodeAt* instr) {
  class DeferredStringCharCodeAt: public LDeferredCode {
   public:
    DeferredStringCharCodeAt(LCodeGen* codegen, LStringCharCodeAt* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() { codegen()->DoDeferredStringCharCodeAt(instr_); }
    virtual LInstruction* instr() { return instr_; }
   private:
    LStringCharCodeAt* instr_;
  };

  DeferredStringCharCodeAt* deferred =
      new(zone()) DeferredStringCharCodeAt(this, instr);

  StringCharLoadGenerator::Generate(masm(),
                                    factory(),
                                    ToRegister(instr->string()),
                                    ToRegister(instr->index()),
                                    ToRegister(instr->result()),
                                    deferred->entry());
  __ bind(deferred->exit());
}


void LCodeGen::DoDeferredStringCharCodeAt(LStringCharCodeAt* instr) {
  Register string = ToRegister(instr->string());
  Register result = ToRegister(instr->result());

  // TODO(3095996): Get rid of this. For now, we need to make the
  // result register contain a valid pointer because it is already
  // contained in the register pointer map.
  __ Set(result, Immediate(0));

  PushSafepointRegistersScope scope(this);
  __ push(string);
  // Push the index as a smi. This is safe because of the checks in
  // DoStringCharCodeAt above.
  STATIC_ASSERT(String::kMaxLength <= Smi::kMaxValue);
  if (instr->index()->IsConstantOperand()) {
    int const_index = ToInteger32(LConstantOperand::cast(instr->index()));
    __ push(Immediate(Smi::FromInt(const_index)));
  } else {
    Register index = ToRegister(instr->index());
    __ SmiTag(index);
    __ push(index);
  }
  CallRuntimeFromDeferred(Runtime::kStringCharCodeAt, 2,
                          instr, instr->context());
  __ AssertSmi(eax);
  __ SmiUntag(eax);
  __ StoreToSafepointRegisterSlot(result, eax);
}


void LCodeGen::DoStringCharFromCode(LStringCharFromCode* instr) {
  class DeferredStringCharFromCode: public LDeferredCode {
   public:
    DeferredStringCharFromCode(LCodeGen* codegen, LStringCharFromCode* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() { codegen()->DoDeferredStringCharFromCode(instr_); }
    virtual LInstruction* instr() { return instr_; }
   private:
    LStringCharFromCode* instr_;
  };

  DeferredStringCharFromCode* deferred =
      new(zone()) DeferredStringCharFromCode(this, instr);

  ASSERT(instr->hydrogen()->value()->representation().IsInteger32());
  Register char_code = ToRegister(instr->char_code());
  Register result = ToRegister(instr->result());
  ASSERT(!char_code.is(result));

  __ cmp(char_code, String::kMaxOneByteCharCode);
  __ j(above, deferred->entry());
  __ Set(result, Immediate(factory()->single_character_string_cache()));
  __ mov(result, FieldOperand(result,
                              char_code, times_pointer_size,
                              FixedArray::kHeaderSize));
  __ cmp(result, factory()->undefined_value());
  __ j(equal, deferred->entry());
  __ bind(deferred->exit());
}


void LCodeGen::DoDeferredStringCharFromCode(LStringCharFromCode* instr) {
  Register char_code = ToRegister(instr->char_code());
  Register result = ToRegister(instr->result());

  // TODO(3095996): Get rid of this. For now, we need to make the
  // result register contain a valid pointer because it is already
  // contained in the register pointer map.
  __ Set(result, Immediate(0));

  PushSafepointRegistersScope scope(this);
  __ SmiTag(char_code);
  __ push(char_code);
  CallRuntimeFromDeferred(Runtime::kCharFromCode, 1, instr, instr->context());
  __ StoreToSafepointRegisterSlot(result, eax);
}


void LCodeGen::DoStringLength(LStringLength* instr) {
  Register string = ToRegister(instr->string());
  Register result = ToRegister(instr->result());
  __ mov(result, FieldOperand(string, String::kLengthOffset));
}


void LCodeGen::DoStringAdd(LStringAdd* instr) {
  EmitPushTaggedOperand(instr->left());
  EmitPushTaggedOperand(instr->right());
  StringAddStub stub(NO_STRING_CHECK_IN_STUB);
  CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
}


void LCodeGen::DoInteger32ToDouble(LInteger32ToDouble* instr) {
  if (CpuFeatures::IsSupported(SSE2)) {
    CpuFeatureScope scope(masm(), SSE2);
    LOperand* input = instr->value();
    ASSERT(input->IsRegister() || input->IsStackSlot());
    LOperand* output = instr->result();
    ASSERT(output->IsDoubleRegister());
    __ cvtsi2sd(ToDoubleRegister(output), ToOperand(input));
  } else {
    UNREACHABLE();
  }
}


void LCodeGen::DoInteger32ToSmi(LInteger32ToSmi* instr) {
  Register input = ToRegister(instr->value());
  __ SmiTag(input);
  if (!instr->hydrogen()->value()->HasRange() ||
      !instr->hydrogen()->value()->range()->IsInSmiRange()) {
    DeoptimizeIf(overflow, instr->environment());
  }
}


void LCodeGen::DoUint32ToDouble(LUint32ToDouble* instr) {
  CpuFeatureScope scope(masm(), SSE2);
  LOperand* input = instr->value();
  LOperand* output = instr->result();
  LOperand* temp = instr->temp();

  __ LoadUint32(ToDoubleRegister(output),
                ToRegister(input),
                ToDoubleRegister(temp));
}


void LCodeGen::DoNumberTagI(LNumberTagI* instr) {
  class DeferredNumberTagI: public LDeferredCode {
   public:
    DeferredNumberTagI(LCodeGen* codegen, LNumberTagI* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() {
      codegen()->DoDeferredNumberTagI(instr_, instr_->value(), SIGNED_INT32);
    }
    virtual LInstruction* instr() { return instr_; }
   private:
    LNumberTagI* instr_;
  };

  LOperand* input = instr->value();
  ASSERT(input->IsRegister() && input->Equals(instr->result()));
  Register reg = ToRegister(input);

  DeferredNumberTagI* deferred = new(zone()) DeferredNumberTagI(this, instr);
  __ SmiTag(reg);
  __ j(overflow, deferred->entry());
  __ bind(deferred->exit());
}


void LCodeGen::DoNumberTagU(LNumberTagU* instr) {
  class DeferredNumberTagU: public LDeferredCode {
   public:
    DeferredNumberTagU(LCodeGen* codegen, LNumberTagU* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() {
      codegen()->DoDeferredNumberTagI(instr_, instr_->value(), UNSIGNED_INT32);
    }
    virtual LInstruction* instr() { return instr_; }
   private:
    LNumberTagU* instr_;
  };

  LOperand* input = instr->value();
  ASSERT(input->IsRegister() && input->Equals(instr->result()));
  Register reg = ToRegister(input);

  DeferredNumberTagU* deferred = new(zone()) DeferredNumberTagU(this, instr);
  __ cmp(reg, Immediate(Smi::kMaxValue));
  __ j(above, deferred->entry());
  __ SmiTag(reg);
  __ bind(deferred->exit());
}


void LCodeGen::DoDeferredNumberTagI(LInstruction* instr,
                                    LOperand* value,
                                    IntegerSignedness signedness) {
  Label slow;
  Register reg = ToRegister(value);
  Register tmp = reg.is(eax) ? ecx : eax;

  // Preserve the value of all registers.
  PushSafepointRegistersScope scope(this);

  Label done;

  if (signedness == SIGNED_INT32) {
    // There was overflow, so bits 30 and 31 of the original integer
    // disagree. Try to allocate a heap number in new space and store
    // the value in there. If that fails, call the runtime system.
    __ SmiUntag(reg);
    __ xor_(reg, 0x80000000);
    if (CpuFeatures::IsSupported(SSE2)) {
      CpuFeatureScope feature_scope(masm(), SSE2);
      __ cvtsi2sd(xmm0, Operand(reg));
    } else {
      __ push(reg);
      __ fild_s(Operand(esp, 0));
      __ pop(reg);
    }
  } else {
    if (CpuFeatures::IsSupported(SSE2)) {
      CpuFeatureScope feature_scope(masm(), SSE2);
      __ LoadUint32(xmm0, reg, xmm1);
    } else {
      // There's no fild variant for unsigned values, so zero-extend to a 64-bit
      // int manually.
      __ push(Immediate(0));
      __ push(reg);
      __ fild_d(Operand(esp, 0));
      __ pop(reg);
      __ pop(reg);
    }
  }

  if (FLAG_inline_new) {
    __ AllocateHeapNumber(reg, tmp, no_reg, &slow);
    __ jmp(&done, Label::kNear);
  }

  // Slow case: Call the runtime system to do the number allocation.
  __ bind(&slow);

  // TODO(3095996): Put a valid pointer value in the stack slot where the result
  // register is stored, as this register is in the pointer map, but contains an
  // integer value.
  __ StoreToSafepointRegisterSlot(reg, Immediate(0));
  // NumberTagI and NumberTagD use the context from the frame, rather than
  // the environment's HContext or HInlinedContext value.
  // They only call Runtime::kAllocateHeapNumber.
  // The corresponding HChange instructions are added in a phase that does
  // not have easy access to the local context.
  __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
  __ CallRuntimeSaveDoubles(Runtime::kAllocateHeapNumber);
  RecordSafepointWithRegisters(
      instr->pointer_map(), 0, Safepoint::kNoLazyDeopt);
  if (!reg.is(eax)) __ mov(reg, eax);

  // Done. Put the value in xmm0 into the value of the allocated heap
  // number.
  __ bind(&done);
  if (CpuFeatures::IsSupported(SSE2)) {
    CpuFeatureScope feature_scope(masm(), SSE2);
    __ movdbl(FieldOperand(reg, HeapNumber::kValueOffset), xmm0);
  } else {
    __ fstp_d(FieldOperand(reg, HeapNumber::kValueOffset));
  }
  __ StoreToSafepointRegisterSlot(reg, reg);
}


void LCodeGen::DoNumberTagD(LNumberTagD* instr) {
  class DeferredNumberTagD: public LDeferredCode {
   public:
    DeferredNumberTagD(LCodeGen* codegen, LNumberTagD* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() { codegen()->DoDeferredNumberTagD(instr_); }
    virtual LInstruction* instr() { return instr_; }
   private:
    LNumberTagD* instr_;
  };

  Register reg = ToRegister(instr->result());

  bool convert_hole = false;
  HValue* change_input = instr->hydrogen()->value();
  if (change_input->IsLoadKeyed()) {
    HLoadKeyed* load = HLoadKeyed::cast(change_input);
    convert_hole = load->UsesMustHandleHole();
  }

  Label no_special_nan_handling;
  Label done;
  if (convert_hole) {
    bool use_sse2 = CpuFeatures::IsSupported(SSE2);
    if (use_sse2) {
      CpuFeatureScope scope(masm(), SSE2);
      XMMRegister input_reg = ToDoubleRegister(instr->value());
      __ ucomisd(input_reg, input_reg);
    } else {
      __ fld(0);
      __ fld(0);
      __ FCmp();
    }

    __ j(parity_odd, &no_special_nan_handling);
    __ sub(esp, Immediate(kDoubleSize));
    if (use_sse2) {
      CpuFeatureScope scope(masm(), SSE2);
      XMMRegister input_reg = ToDoubleRegister(instr->value());
      __ movdbl(MemOperand(esp, 0), input_reg);
    } else {
      __ fld(0);
      __ fstp_d(MemOperand(esp, 0));
    }
    __ cmp(MemOperand(esp, sizeof(kHoleNanLower32)),
           Immediate(kHoleNanUpper32));
    Label canonicalize;
    __ j(not_equal, &canonicalize);
    __ add(esp, Immediate(kDoubleSize));
    __ mov(reg, factory()->the_hole_value());
    if (!use_sse2) {
      __ fstp(0);
    }
    __ jmp(&done);
    __ bind(&canonicalize);
    __ add(esp, Immediate(kDoubleSize));
    ExternalReference nan =
        ExternalReference::address_of_canonical_non_hole_nan();
    if (use_sse2) {
      CpuFeatureScope scope(masm(), SSE2);
      XMMRegister input_reg = ToDoubleRegister(instr->value());
      __ movdbl(input_reg, Operand::StaticVariable(nan));
    } else {
      __ fstp(0);
      __ fld_d(Operand::StaticVariable(nan));
    }
  }

  __ bind(&no_special_nan_handling);
  DeferredNumberTagD* deferred = new(zone()) DeferredNumberTagD(this, instr);
  if (FLAG_inline_new) {
    Register tmp = ToRegister(instr->temp());
    __ AllocateHeapNumber(reg, tmp, no_reg, deferred->entry());
  } else {
    __ jmp(deferred->entry());
  }
  __ bind(deferred->exit());
  if (CpuFeatures::IsSupported(SSE2)) {
    CpuFeatureScope scope(masm(), SSE2);
    XMMRegister input_reg = ToDoubleRegister(instr->value());
    __ movdbl(FieldOperand(reg, HeapNumber::kValueOffset), input_reg);
  } else {
    __ fst_d(FieldOperand(reg, HeapNumber::kValueOffset));
  }
  __ bind(&done);
}


void LCodeGen::DoDeferredNumberTagD(LNumberTagD* instr) {
  // TODO(3095996): Get rid of this. For now, we need to make the
  // result register contain a valid pointer because it is already
  // contained in the register pointer map.
  Register reg = ToRegister(instr->result());
  __ Set(reg, Immediate(0));

  PushSafepointRegistersScope scope(this);
  // NumberTagI and NumberTagD use the context from the frame, rather than
  // the environment's HContext or HInlinedContext value.
  // They only call Runtime::kAllocateHeapNumber.
  // The corresponding HChange instructions are added in a phase that does
  // not have easy access to the local context.
  __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
  __ CallRuntimeSaveDoubles(Runtime::kAllocateHeapNumber);
  RecordSafepointWithRegisters(
      instr->pointer_map(), 0, Safepoint::kNoLazyDeopt);
  __ StoreToSafepointRegisterSlot(reg, eax);
}


void LCodeGen::DoSmiTag(LSmiTag* instr) {
  LOperand* input = instr->value();
  ASSERT(input->IsRegister() && input->Equals(instr->result()));
  ASSERT(!instr->hydrogen_value()->CheckFlag(HValue::kCanOverflow));
  __ SmiTag(ToRegister(input));
}


void LCodeGen::DoSmiUntag(LSmiUntag* instr) {
  LOperand* input = instr->value();
  Register result = ToRegister(input);
  ASSERT(input->IsRegister() && input->Equals(instr->result()));
  if (instr->needs_check()) {
    __ test(result, Immediate(kSmiTagMask));
    DeoptimizeIf(not_zero, instr->environment());
  } else {
    __ AssertSmi(result);
  }
  __ SmiUntag(result);
}


void LCodeGen::EmitNumberUntagDNoSSE2(Register input_reg,
                                      Register temp_reg,
                                      bool allow_undefined_as_nan,
                                      bool deoptimize_on_minus_zero,
                                      LEnvironment* env,
                                      NumberUntagDMode mode) {
  Label load_smi, done;

  STATIC_ASSERT(NUMBER_CANDIDATE_IS_ANY_TAGGED_CONVERT_HOLE >
                NUMBER_CANDIDATE_IS_ANY_TAGGED);
  if (mode >= NUMBER_CANDIDATE_IS_ANY_TAGGED) {
    // Smi check.
    __ JumpIfSmi(input_reg, &load_smi, Label::kNear);

    // Heap number map check.
    __ cmp(FieldOperand(input_reg, HeapObject::kMapOffset),
           factory()->heap_number_map());
    if (!allow_undefined_as_nan) {
      DeoptimizeIf(not_equal, env);
    } else {
      Label heap_number, convert;
      __ j(equal, &heap_number, Label::kNear);

      // Convert undefined (or hole) to NaN.
      __ cmp(input_reg, factory()->undefined_value());
      if (mode == NUMBER_CANDIDATE_IS_ANY_TAGGED_CONVERT_HOLE) {
        __ j(equal, &convert, Label::kNear);
        __ cmp(input_reg, factory()->the_hole_value());
      }
      DeoptimizeIf(not_equal, env);

      __ bind(&convert);
      ExternalReference nan =
          ExternalReference::address_of_canonical_non_hole_nan();
      __ fld_d(Operand::StaticVariable(nan));
      __ jmp(&done, Label::kNear);

      __ bind(&heap_number);
    }
    // Heap number to x87 conversion.
    __ fld_d(FieldOperand(input_reg, HeapNumber::kValueOffset));
    if (deoptimize_on_minus_zero) {
      __ fldz();
      __ FCmp();
      __ fld_d(FieldOperand(input_reg, HeapNumber::kValueOffset));
      __ j(not_zero, &done, Label::kNear);

      // Use general purpose registers to check if we have -0.0
      __ mov(temp_reg, FieldOperand(input_reg, HeapNumber::kExponentOffset));
      __ test(temp_reg, Immediate(HeapNumber::kSignMask));
      __ j(zero, &done, Label::kNear);

      // Pop FPU stack before deoptimizing.
      __ fstp(0);
      DeoptimizeIf(not_zero, env);
    }
    __ jmp(&done, Label::kNear);
  } else {
    ASSERT(mode == NUMBER_CANDIDATE_IS_SMI);
  }

  __ bind(&load_smi);
  __ SmiUntag(input_reg);  // Untag smi before converting to float.
  __ push(input_reg);
  __ fild_s(Operand(esp, 0));
  __ pop(input_reg);
  __ SmiTag(input_reg);  // Retag smi.
  __ bind(&done);
}


void LCodeGen::EmitNumberUntagD(Register input_reg,
                                Register temp_reg,
                                XMMRegister result_reg,
                                bool allow_undefined_as_nan,
                                bool deoptimize_on_minus_zero,
                                LEnvironment* env,
                                NumberUntagDMode mode) {
  Label load_smi, done;

  STATIC_ASSERT(NUMBER_CANDIDATE_IS_ANY_TAGGED_CONVERT_HOLE >
                NUMBER_CANDIDATE_IS_ANY_TAGGED);
  if (mode >= NUMBER_CANDIDATE_IS_ANY_TAGGED) {
    // Smi check.
    __ JumpIfSmi(input_reg, &load_smi, Label::kNear);

    // Heap number map check.
    __ cmp(FieldOperand(input_reg, HeapObject::kMapOffset),
           factory()->heap_number_map());
    if (!allow_undefined_as_nan) {
      DeoptimizeIf(not_equal, env);
    } else {
      Label heap_number, convert;
      __ j(equal, &heap_number, Label::kNear);

      // Convert undefined (and hole) to NaN.
      __ cmp(input_reg, factory()->undefined_value());
      if (mode == NUMBER_CANDIDATE_IS_ANY_TAGGED_CONVERT_HOLE) {
        __ j(equal, &convert, Label::kNear);
        __ cmp(input_reg, factory()->the_hole_value());
      }
      DeoptimizeIf(not_equal, env);

      __ bind(&convert);
      ExternalReference nan =
          ExternalReference::address_of_canonical_non_hole_nan();
      __ movdbl(result_reg, Operand::StaticVariable(nan));
      __ jmp(&done, Label::kNear);

      __ bind(&heap_number);
    }
    // Heap number to XMM conversion.
    __ movdbl(result_reg, FieldOperand(input_reg, HeapNumber::kValueOffset));
    if (deoptimize_on_minus_zero) {
      XMMRegister xmm_scratch = xmm0;
      __ xorps(xmm_scratch, xmm_scratch);
      __ ucomisd(result_reg, xmm_scratch);
      __ j(not_zero, &done, Label::kNear);
      __ movmskpd(temp_reg, result_reg);
      __ test_b(temp_reg, 1);
      DeoptimizeIf(not_zero, env);
    }
    __ jmp(&done, Label::kNear);
  } else {
    ASSERT(mode == NUMBER_CANDIDATE_IS_SMI);
  }

  // Smi to XMM conversion
  __ bind(&load_smi);
  __ SmiUntag(input_reg);  // Untag smi before converting to float.
  __ cvtsi2sd(result_reg, Operand(input_reg));
  __ SmiTag(input_reg);  // Retag smi.
  __ bind(&done);
}


void LCodeGen::DoDeferredTaggedToI(LTaggedToI* instr) {
  Label done, heap_number;
  Register input_reg = ToRegister(instr->value());

  // Heap number map check.
  __ cmp(FieldOperand(input_reg, HeapObject::kMapOffset),
         factory()->heap_number_map());

  if (instr->truncating()) {
    __ j(equal, &heap_number, Label::kNear);
    // Check for undefined. Undefined is converted to zero for truncating
    // conversions.
    __ cmp(input_reg, factory()->undefined_value());
    __ RecordComment("Deferred TaggedToI: cannot truncate");
    DeoptimizeIf(not_equal, instr->environment());
    __ mov(input_reg, 0);
    __ jmp(&done, Label::kNear);

    __ bind(&heap_number);
    if (CpuFeatures::IsSupported(SSE3)) {
      CpuFeatureScope scope(masm(), SSE3);
      Label convert;
      // Use more powerful conversion when sse3 is available.
      // Load x87 register with heap number.
      __ fld_d(FieldOperand(input_reg, HeapNumber::kValueOffset));
      // Get exponent alone and check for too-big exponent.
      __ mov(input_reg, FieldOperand(input_reg, HeapNumber::kExponentOffset));
      __ and_(input_reg, HeapNumber::kExponentMask);
      const uint32_t kTooBigExponent =
          (HeapNumber::kExponentBias + 63) << HeapNumber::kExponentShift;
      __ cmp(Operand(input_reg), Immediate(kTooBigExponent));
      __ j(less, &convert, Label::kNear);
      // Pop FPU stack before deoptimizing.
      __ fstp(0);
      __ RecordComment("Deferred TaggedToI: exponent too big");
      DeoptimizeIf(no_condition, instr->environment());

      // Reserve space for 64 bit answer.
      __ bind(&convert);
      __ sub(Operand(esp), Immediate(kDoubleSize));
      // Do conversion, which cannot fail because we checked the exponent.
      __ fisttp_d(Operand(esp, 0));
      __ mov(input_reg, Operand(esp, 0));  // Low word of answer is the result.
      __ add(Operand(esp), Immediate(kDoubleSize));
    } else if (CpuFeatures::IsSupported(SSE2)) {
      CpuFeatureScope scope(masm(), SSE2);
      XMMRegister xmm_temp = ToDoubleRegister(instr->temp());
      __ movdbl(xmm0, FieldOperand(input_reg, HeapNumber::kValueOffset));
      __ cvttsd2si(input_reg, Operand(xmm0));
      __ cmp(input_reg, 0x80000000u);
      __ j(not_equal, &done);
      // Check if the input was 0x8000000 (kMinInt).
      // If no, then we got an overflow and we deoptimize.
      ExternalReference min_int = ExternalReference::address_of_min_int();
      __ movdbl(xmm_temp, Operand::StaticVariable(min_int));
      __ ucomisd(xmm_temp, xmm0);
      DeoptimizeIf(not_equal, instr->environment());
      DeoptimizeIf(parity_even, instr->environment());  // NaN.
    } else {
      UNREACHABLE();
    }
  } else if (CpuFeatures::IsSupported(SSE2)) {
    CpuFeatureScope scope(masm(), SSE2);
    // Deoptimize if we don't have a heap number.
    __ RecordComment("Deferred TaggedToI: not a heap number");
    DeoptimizeIf(not_equal, instr->environment());

    XMMRegister xmm_temp = ToDoubleRegister(instr->temp());
    __ movdbl(xmm0, FieldOperand(input_reg, HeapNumber::kValueOffset));
    __ cvttsd2si(input_reg, Operand(xmm0));
    __ cvtsi2sd(xmm_temp, Operand(input_reg));
    __ ucomisd(xmm0, xmm_temp);
    __ RecordComment("Deferred TaggedToI: lost precision");
    DeoptimizeIf(not_equal, instr->environment());
    __ RecordComment("Deferred TaggedToI: NaN");
    DeoptimizeIf(parity_even, instr->environment());  // NaN.
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      __ test(input_reg, Operand(input_reg));
      __ j(not_zero, &done);
      __ movmskpd(input_reg, xmm0);
      __ and_(input_reg, 1);
      __ RecordComment("Deferred TaggedToI: minus zero");
      DeoptimizeIf(not_zero, instr->environment());
    }
  } else {
    UNREACHABLE();
  }
  __ bind(&done);
}


void LCodeGen::DoTaggedToI(LTaggedToI* instr) {
  class DeferredTaggedToI: public LDeferredCode {
   public:
    DeferredTaggedToI(LCodeGen* codegen, LTaggedToI* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() { codegen()->DoDeferredTaggedToI(instr_); }
    virtual LInstruction* instr() { return instr_; }
   private:
    LTaggedToI* instr_;
  };

  LOperand* input = instr->value();
  ASSERT(input->IsRegister());
  Register input_reg = ToRegister(input);
  ASSERT(input_reg.is(ToRegister(instr->result())));

  DeferredTaggedToI* deferred = new(zone()) DeferredTaggedToI(this, instr);

  __ JumpIfNotSmi(input_reg, deferred->entry());
  __ SmiUntag(input_reg);
  __ bind(deferred->exit());
}


void LCodeGen::DoDeferredTaggedToINoSSE2(LTaggedToINoSSE2* instr) {
  Label done, heap_number;
  Register result_reg = ToRegister(instr->result());
  Register input_reg = ToRegister(instr->value());

  // Heap number map check.
  __ cmp(FieldOperand(input_reg, HeapObject::kMapOffset),
         factory()->heap_number_map());
  if (instr->truncating()) {
    __ j(equal, &heap_number, Label::kNear);
    // Check for undefined. Undefined is converted to zero for truncating
    // conversions.
    __ cmp(input_reg, factory()->undefined_value());
    __ RecordComment("Deferred TaggedToI: cannot truncate");
    DeoptimizeIf(not_equal, instr->environment());
    __ xor_(result_reg, result_reg);
    __ jmp(&done, Label::kFar);
    __ bind(&heap_number);
  } else {
    // Deoptimize if we don't have a heap number.
    DeoptimizeIf(not_equal, instr->environment());
  }

  // Surprisingly, all of this crazy bit manipulation is considerably
  // faster than using the built-in x86 CPU conversion functions (about 6x).
  Label right_exponent, adjust_bias, zero_result;
  Register scratch = ToRegister(instr->scratch());
  Register scratch2 = ToRegister(instr->scratch2());
  // Get exponent word.
  __ mov(scratch, FieldOperand(input_reg, HeapNumber::kExponentOffset));
  // Get exponent alone in scratch2.
  __ mov(scratch2, scratch);
  __ and_(scratch2, HeapNumber::kExponentMask);
  __ shr(scratch2, HeapNumber::kExponentShift);
  if (instr->truncating()) {
    __ j(zero, &zero_result);
  } else {
    __ j(not_zero, &adjust_bias);
    __ test(scratch, Immediate(HeapNumber::kMantissaMask));
    DeoptimizeIf(not_zero, instr->environment());
    __ cmp(FieldOperand(input_reg, HeapNumber::kMantissaOffset), Immediate(0));
    DeoptimizeIf(not_equal, instr->environment());
    __ bind(&adjust_bias);
  }
  __ sub(scratch2, Immediate(HeapNumber::kExponentBias));
  if (!instr->truncating()) {
    DeoptimizeIf(negative, instr->environment());
  } else {
    __ j(negative, &zero_result);
  }

  // Get the second half of the double. For some exponents we don't
  // actually need this because the bits get shifted out again, but
  // it's probably slower to test than just to do it.
  Register scratch3 = ToRegister(instr->scratch3());
  __ mov(scratch3, FieldOperand(input_reg, HeapNumber::kMantissaOffset));
  __ xor_(result_reg, result_reg);

  const uint32_t non_int32_exponent = 31;
  __ cmp(scratch2, Immediate(non_int32_exponent));
  // If we have a match of the int32 exponent then skip some logic.
  __ j(equal, &right_exponent, Label::kNear);
  // If the number doesn't find in an int32, deopt.
  DeoptimizeIf(greater, instr->environment());

  // Exponent word in scratch, exponent in scratch2.  We know that 0 <= exponent
  // < 31.
  __ mov(result_reg, Immediate(31));
  __ sub(result_reg, scratch2);

  __ bind(&right_exponent);

  // Save off exponent for negative check later.
  __ mov(scratch2, scratch);

  // Here result_reg is the shift, scratch is the exponent word.
  // Get the top bits of the mantissa.
  __ and_(scratch, HeapNumber::kMantissaMask);
  // Put back the implicit 1.
  __ or_(scratch, 1 << HeapNumber::kExponentShift);
  // Shift up the mantissa bits to take up the space the exponent used to
  // take. We have kExponentShift + 1 significant bits int he low end of the
  // word.  Shift them to the top bits.
  const int shift_distance = HeapNumber::kNonMantissaBitsInTopWord - 1;
  __ shl(scratch, shift_distance);
  if (!instr->truncating()) {
    // If not truncating, a non-zero value in the bottom 22 bits means a
    // non-integral value --> trigger a deopt.
    __ test(scratch3, Immediate((1 << (32 - shift_distance)) - 1));
    DeoptimizeIf(not_equal, instr->environment());
  }
  // Shift down 22 bits to get the most significant 10 bits or the low
  // mantissa word.
  __ shr(scratch3, 32 - shift_distance);
  __ or_(scratch3, scratch);
  if (!instr->truncating()) {
    // If truncating, a non-zero value in the bits that will be shifted away
    // when adjusting the exponent means rounding --> deopt.
    __ mov(scratch, 0x1);
    ASSERT(result_reg.is(ecx));
    __ shl_cl(scratch);
    __ dec(scratch);
    __ test(scratch3, scratch);
    DeoptimizeIf(not_equal, instr->environment());
  }
  // Move down according to the exponent.
  ASSERT(result_reg.is(ecx));
  __ shr_cl(scratch3);
  // Now the unsigned 32-bit answer is in scratch3.  We need to move it to
  // result_reg and we may need to fix the sign.
  Label negative_result;
  __ xor_(result_reg, result_reg);
  __ cmp(scratch2, result_reg);
  __ j(less, &negative_result, Label::kNear);
  __ cmp(scratch3, result_reg);
  __ mov(result_reg, scratch3);
  // If the result is > MAX_INT, result doesn't fit in signed 32-bit --> deopt.
  DeoptimizeIf(less, instr->environment());
  __ jmp(&done, Label::kNear);
  __ bind(&zero_result);
  __ xor_(result_reg, result_reg);
  __ jmp(&done, Label::kNear);
  __ bind(&negative_result);
  __ sub(result_reg, scratch3);
  if (!instr->truncating()) {
    // -0.0 triggers a deopt.
    DeoptimizeIf(zero, instr->environment());
  }
  // If the negative subtraction overflows into a positive number, there was an
  // overflow --> deopt.
  DeoptimizeIf(positive, instr->environment());
  __ bind(&done);
}


void LCodeGen::DoTaggedToINoSSE2(LTaggedToINoSSE2* instr) {
  class DeferredTaggedToINoSSE2: public LDeferredCode {
   public:
    DeferredTaggedToINoSSE2(LCodeGen* codegen, LTaggedToINoSSE2* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() { codegen()->DoDeferredTaggedToINoSSE2(instr_); }
    virtual LInstruction* instr() { return instr_; }
   private:
    LTaggedToINoSSE2* instr_;
  };

  LOperand* input = instr->value();
  ASSERT(input->IsRegister());
  Register input_reg = ToRegister(input);
  ASSERT(input_reg.is(ToRegister(instr->result())));

  DeferredTaggedToINoSSE2* deferred =
      new(zone()) DeferredTaggedToINoSSE2(this, instr);

  // Smi check.
  __ JumpIfNotSmi(input_reg, deferred->entry());
  __ SmiUntag(input_reg);  // Untag smi.
  __ bind(deferred->exit());
}


void LCodeGen::DoNumberUntagD(LNumberUntagD* instr) {
  LOperand* input = instr->value();
  ASSERT(input->IsRegister());
  LOperand* temp = instr->temp();
  ASSERT(temp == NULL || temp->IsRegister());
  LOperand* result = instr->result();
  ASSERT(result->IsDoubleRegister());

  Register input_reg = ToRegister(input);
  bool deoptimize_on_minus_zero =
      instr->hydrogen()->deoptimize_on_minus_zero();
  Register temp_reg = deoptimize_on_minus_zero ? ToRegister(temp) : no_reg;

  NumberUntagDMode mode = NUMBER_CANDIDATE_IS_ANY_TAGGED;
  HValue* value = instr->hydrogen()->value();
  if (value->representation().IsSmi()) {
    mode = NUMBER_CANDIDATE_IS_SMI;
  } else if (value->IsLoadKeyed()) {
    HLoadKeyed* load = HLoadKeyed::cast(value);
    if (load->UsesMustHandleHole()) {
      mode = NUMBER_CANDIDATE_IS_ANY_TAGGED_CONVERT_HOLE;
    }
  }

  if (CpuFeatures::IsSupported(SSE2)) {
    CpuFeatureScope scope(masm(), SSE2);
    XMMRegister result_reg = ToDoubleRegister(result);
    EmitNumberUntagD(input_reg,
                     temp_reg,
                     result_reg,
                     instr->hydrogen()->allow_undefined_as_nan(),
                     deoptimize_on_minus_zero,
                     instr->environment(),
                     mode);
  } else {
    EmitNumberUntagDNoSSE2(input_reg,
                           temp_reg,
                           instr->hydrogen()->allow_undefined_as_nan(),
                           deoptimize_on_minus_zero,
                           instr->environment(),
                           mode);
    CurrentInstructionReturnsX87Result();
  }
}


void LCodeGen::DoDoubleToI(LDoubleToI* instr) {
  LOperand* input = instr->value();
  ASSERT(input->IsDoubleRegister());
  LOperand* result = instr->result();
  ASSERT(result->IsRegister());
  CpuFeatureScope scope(masm(), SSE2);

  XMMRegister input_reg = ToDoubleRegister(input);
  Register result_reg = ToRegister(result);

  if (instr->truncating()) {
    // Performs a truncating conversion of a floating point number as used by
    // the JS bitwise operations.
    __ cvttsd2si(result_reg, Operand(input_reg));
    __ cmp(result_reg, 0x80000000u);
    if (CpuFeatures::IsSupported(SSE3)) {
      // This will deoptimize if the exponent of the input in out of range.
      CpuFeatureScope scope(masm(), SSE3);
      Label convert, done;
      __ j(not_equal, &done, Label::kNear);
      __ sub(Operand(esp), Immediate(kDoubleSize));
      __ movdbl(Operand(esp, 0), input_reg);
      // Get exponent alone and check for too-big exponent.
      __ mov(result_reg, Operand(esp, sizeof(int32_t)));
      __ and_(result_reg, HeapNumber::kExponentMask);
      const uint32_t kTooBigExponent =
          (HeapNumber::kExponentBias + 63) << HeapNumber::kExponentShift;
      __ cmp(Operand(result_reg), Immediate(kTooBigExponent));
      __ j(less, &convert, Label::kNear);
      __ add(Operand(esp), Immediate(kDoubleSize));
      DeoptimizeIf(no_condition, instr->environment());
      __ bind(&convert);
      // Do conversion, which cannot fail because we checked the exponent.
      __ fld_d(Operand(esp, 0));
      __ fisttp_d(Operand(esp, 0));
      __ mov(result_reg, Operand(esp, 0));  // Low word of answer is the result.
      __ add(Operand(esp), Immediate(kDoubleSize));
      __ bind(&done);
    } else {
      Label done;
      Register temp_reg = ToRegister(instr->temp());
      XMMRegister xmm_scratch = xmm0;

      // If cvttsd2si succeeded, we're done. Otherwise, we attempt
      // manual conversion.
      __ j(not_equal, &done, Label::kNear);

      // Get high 32 bits of the input in result_reg and temp_reg.
      __ pshufd(xmm_scratch, input_reg, 1);
      __ movd(Operand(temp_reg), xmm_scratch);
      __ mov(result_reg, temp_reg);

      // Prepare negation mask in temp_reg.
      __ sar(temp_reg, kBitsPerInt - 1);

      // Extract the exponent from result_reg and subtract adjusted
      // bias from it. The adjustment is selected in a way such that
      // when the difference is zero, the answer is in the low 32 bits
      // of the input, otherwise a shift has to be performed.
      __ shr(result_reg, HeapNumber::kExponentShift);
      __ and_(result_reg,
              HeapNumber::kExponentMask >> HeapNumber::kExponentShift);
      __ sub(Operand(result_reg),
             Immediate(HeapNumber::kExponentBias +
                       HeapNumber::kExponentBits +
                       HeapNumber::kMantissaBits));
      // Don't handle big (> kMantissaBits + kExponentBits == 63) or
      // special exponents.
      DeoptimizeIf(greater, instr->environment());

      // Zero out the sign and the exponent in the input (by shifting
      // it to the left) and restore the implicit mantissa bit,
      // i.e. convert the input to unsigned int64 shifted left by
      // kExponentBits.
      ExternalReference minus_zero = ExternalReference::address_of_minus_zero();
      // Minus zero has the most significant bit set and the other
      // bits cleared.
      __ movdbl(xmm_scratch, Operand::StaticVariable(minus_zero));
      __ psllq(input_reg, HeapNumber::kExponentBits);
      __ por(input_reg, xmm_scratch);

      // Get the amount to shift the input right in xmm_scratch.
      __ neg(result_reg);
      __ movd(xmm_scratch, Operand(result_reg));

      // Shift the input right and extract low 32 bits.
      __ psrlq(input_reg, xmm_scratch);
      __ movd(Operand(result_reg), input_reg);

      // Use the prepared mask in temp_reg to negate the result if necessary.
      __ xor_(result_reg, Operand(temp_reg));
      __ sub(result_reg, Operand(temp_reg));
      __ bind(&done);
    }
  } else {
    Label done;
    __ cvttsd2si(result_reg, Operand(input_reg));
    __ cvtsi2sd(xmm0, Operand(result_reg));
    __ ucomisd(xmm0, input_reg);
    DeoptimizeIf(not_equal, instr->environment());
    DeoptimizeIf(parity_even, instr->environment());  // NaN.
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      // The integer converted back is equal to the original. We
      // only have to test if we got -0 as an input.
      __ test(result_reg, Operand(result_reg));
      __ j(not_zero, &done, Label::kNear);
      __ movmskpd(result_reg, input_reg);
      // Bit 0 contains the sign of the double in input_reg.
      // If input was positive, we are ok and return 0, otherwise
      // deoptimize.
      __ and_(result_reg, 1);
      DeoptimizeIf(not_zero, instr->environment());
    }
    __ bind(&done);
  }
}


void LCodeGen::DoDoubleToSmi(LDoubleToSmi* instr) {
  LOperand* input = instr->value();
  ASSERT(input->IsDoubleRegister());
  LOperand* result = instr->result();
  ASSERT(result->IsRegister());
  CpuFeatureScope scope(masm(), SSE2);

  XMMRegister input_reg = ToDoubleRegister(input);
  Register result_reg = ToRegister(result);

  Label done;
  __ cvttsd2si(result_reg, Operand(input_reg));
  __ cvtsi2sd(xmm0, Operand(result_reg));
  __ ucomisd(xmm0, input_reg);
  DeoptimizeIf(not_equal, instr->environment());
  DeoptimizeIf(parity_even, instr->environment());  // NaN.

  if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
    // The integer converted back is equal to the original. We
    // only have to test if we got -0 as an input.
    __ test(result_reg, Operand(result_reg));
    __ j(not_zero, &done, Label::kNear);
    __ movmskpd(result_reg, input_reg);
    // Bit 0 contains the sign of the double in input_reg.
    // If input was positive, we are ok and return 0, otherwise
    // deoptimize.
    __ and_(result_reg, 1);
    DeoptimizeIf(not_zero, instr->environment());
    __ bind(&done);
  }
  __ SmiTag(result_reg);
  DeoptimizeIf(overflow, instr->environment());
}


void LCodeGen::DoCheckSmi(LCheckSmi* instr) {
  LOperand* input = instr->value();
  __ test(ToOperand(input), Immediate(kSmiTagMask));
  DeoptimizeIf(not_zero, instr->environment());
}


void LCodeGen::DoCheckNonSmi(LCheckNonSmi* instr) {
  LOperand* input = instr->value();
  __ test(ToOperand(input), Immediate(kSmiTagMask));
  DeoptimizeIf(zero, instr->environment());
}


void LCodeGen::DoCheckInstanceType(LCheckInstanceType* instr) {
  Register input = ToRegister(instr->value());
  Register temp = ToRegister(instr->temp());

  __ mov(temp, FieldOperand(input, HeapObject::kMapOffset));

  if (instr->hydrogen()->is_interval_check()) {
    InstanceType first;
    InstanceType last;
    instr->hydrogen()->GetCheckInterval(&first, &last);

    __ cmpb(FieldOperand(temp, Map::kInstanceTypeOffset),
            static_cast<int8_t>(first));

    // If there is only one type in the interval check for equality.
    if (first == last) {
      DeoptimizeIf(not_equal, instr->environment());
    } else {
      DeoptimizeIf(below, instr->environment());
      // Omit check for the last type.
      if (last != LAST_TYPE) {
        __ cmpb(FieldOperand(temp, Map::kInstanceTypeOffset),
                static_cast<int8_t>(last));
        DeoptimizeIf(above, instr->environment());
      }
    }
  } else {
    uint8_t mask;
    uint8_t tag;
    instr->hydrogen()->GetCheckMaskAndTag(&mask, &tag);

    if (IsPowerOf2(mask)) {
      ASSERT(tag == 0 || IsPowerOf2(tag));
      __ test_b(FieldOperand(temp, Map::kInstanceTypeOffset), mask);
      DeoptimizeIf(tag == 0 ? not_zero : zero, instr->environment());
    } else {
      __ movzx_b(temp, FieldOperand(temp, Map::kInstanceTypeOffset));
      __ and_(temp, mask);
      __ cmp(temp, tag);
      DeoptimizeIf(not_equal, instr->environment());
    }
  }
}


void LCodeGen::DoCheckFunction(LCheckFunction* instr) {
  Handle<JSFunction> target = instr->hydrogen()->target();
  if (instr->hydrogen()->target_in_new_space()) {
    Register reg = ToRegister(instr->value());
    Handle<JSGlobalPropertyCell> cell =
        isolate()->factory()->NewJSGlobalPropertyCell(target);
    __ cmp(reg, Operand::Cell(cell));
  } else {
    Operand operand = ToOperand(instr->value());
    __ cmp(operand, target);
  }
  DeoptimizeIf(not_equal, instr->environment());
}


void LCodeGen::DoCheckMapCommon(Register reg,
                                Handle<Map> map,
                                LInstruction* instr) {
  Label success;
  __ CompareMap(reg, map, &success);
  DeoptimizeIf(not_equal, instr->environment());
  __ bind(&success);
}


void LCodeGen::DoCheckMaps(LCheckMaps* instr) {
  LOperand* input = instr->value();
  ASSERT(input->IsRegister());
  Register reg = ToRegister(input);

  Label success;
  SmallMapList* map_set = instr->hydrogen()->map_set();
  for (int i = 0; i < map_set->length() - 1; i++) {
    Handle<Map> map = map_set->at(i);
    __ CompareMap(reg, map, &success);
    __ j(equal, &success);
  }
  Handle<Map> map = map_set->last();
  DoCheckMapCommon(reg, map, instr);
  __ bind(&success);
}


void LCodeGen::DoClampDToUint8(LClampDToUint8* instr) {
  CpuFeatureScope scope(masm(), SSE2);
  XMMRegister value_reg = ToDoubleRegister(instr->unclamped());
  Register result_reg = ToRegister(instr->result());
  __ ClampDoubleToUint8(value_reg, xmm0, result_reg);
}


void LCodeGen::DoClampIToUint8(LClampIToUint8* instr) {
  ASSERT(instr->unclamped()->Equals(instr->result()));
  Register value_reg = ToRegister(instr->result());
  __ ClampUint8(value_reg);
}


void LCodeGen::DoClampTToUint8(LClampTToUint8* instr) {
  CpuFeatureScope scope(masm(), SSE2);

  ASSERT(instr->unclamped()->Equals(instr->result()));
  Register input_reg = ToRegister(instr->unclamped());
  Label is_smi, done, heap_number;

  __ JumpIfSmi(input_reg, &is_smi);

  // Check for heap number
  __ cmp(FieldOperand(input_reg, HeapObject::kMapOffset),
         factory()->heap_number_map());
  __ j(equal, &heap_number, Label::kNear);

  // Check for undefined. Undefined is converted to zero for clamping
  // conversions.
  __ cmp(input_reg, factory()->undefined_value());
  DeoptimizeIf(not_equal, instr->environment());
  __ mov(input_reg, 0);
  __ jmp(&done, Label::kNear);

  // Heap number
  __ bind(&heap_number);
  __ movdbl(xmm0, FieldOperand(input_reg, HeapNumber::kValueOffset));
  __ ClampDoubleToUint8(xmm0, xmm1, input_reg);
  __ jmp(&done, Label::kNear);

  // smi
  __ bind(&is_smi);
  __ SmiUntag(input_reg);
  __ ClampUint8(input_reg);
  __ bind(&done);
}


void LCodeGen::DoClampTToUint8NoSSE2(LClampTToUint8NoSSE2* instr) {
  Register input_reg = ToRegister(instr->unclamped());
  Register result_reg = ToRegister(instr->result());
  Register scratch = ToRegister(instr->scratch());
  Register scratch2 = ToRegister(instr->scratch2());
  Register scratch3 = ToRegister(instr->scratch3());
  Label is_smi, done, heap_number, valid_exponent,
      largest_value, zero_result, maybe_nan_or_infinity;

  __ JumpIfSmi(input_reg, &is_smi);

  // Check for heap number
  __ cmp(FieldOperand(input_reg, HeapObject::kMapOffset),
         factory()->heap_number_map());
  __ j(equal, &heap_number, Label::kFar);

  // Check for undefined. Undefined is converted to zero for clamping
  // conversions.
  __ cmp(input_reg, factory()->undefined_value());
  DeoptimizeIf(not_equal, instr->environment());
  __ jmp(&zero_result);

  // Heap number
  __ bind(&heap_number);

  // Surprisingly, all of the hand-crafted bit-manipulations below are much
  // faster than the x86 FPU built-in instruction, especially since "banker's
  // rounding" would be additionally very expensive

  // Get exponent word.
  __ mov(scratch, FieldOperand(input_reg, HeapNumber::kExponentOffset));
  __ mov(scratch3, FieldOperand(input_reg, HeapNumber::kMantissaOffset));

  // Test for negative values --> clamp to zero
  __ test(scratch, scratch);
  __ j(negative, &zero_result);

  // Get exponent alone in scratch2.
  __ mov(scratch2, scratch);
  __ and_(scratch2, HeapNumber::kExponentMask);
  __ shr(scratch2, HeapNumber::kExponentShift);
  __ j(zero, &zero_result);
  __ sub(scratch2, Immediate(HeapNumber::kExponentBias - 1));
  __ j(negative, &zero_result);

  const uint32_t non_int8_exponent = 7;
  __ cmp(scratch2, Immediate(non_int8_exponent + 1));
  // If the exponent is too big, check for special values.
  __ j(greater, &maybe_nan_or_infinity, Label::kNear);

  __ bind(&valid_exponent);
  // Exponent word in scratch, exponent in scratch2. We know that 0 <= exponent
  // < 7. The shift bias is the number of bits to shift the mantissa such that
  // with an exponent of 7 such the that top-most one is in bit 30, allowing
  // detection the rounding overflow of a 255.5 to 256 (bit 31 goes from 0 to
  // 1).
  int shift_bias = (30 - HeapNumber::kExponentShift) - 7 - 1;
  __ lea(result_reg, MemOperand(scratch2, shift_bias));
  // Here result_reg (ecx) is the shift, scratch is the exponent word.  Get the
  // top bits of the mantissa.
  __ and_(scratch, HeapNumber::kMantissaMask);
  // Put back the implicit 1 of the mantissa
  __ or_(scratch, 1 << HeapNumber::kExponentShift);
  // Shift up to round
  __ shl_cl(scratch);
  // Use "banker's rounding" to spec: If fractional part of number is 0.5, then
  // use the bit in the "ones" place and add it to the "halves" place, which has
  // the effect of rounding to even.
  __ mov(scratch2, scratch);
  const uint32_t one_half_bit_shift = 30 - sizeof(uint8_t) * 8;
  const uint32_t one_bit_shift = one_half_bit_shift + 1;
  __ and_(scratch2, Immediate((1 << one_bit_shift) - 1));
  __ cmp(scratch2, Immediate(1 << one_half_bit_shift));
  Label no_round;
  __ j(less, &no_round);
  Label round_up;
  __ mov(scratch2, Immediate(1 << one_half_bit_shift));
  __ j(greater, &round_up);
  __ test(scratch3, scratch3);
  __ j(not_zero, &round_up);
  __ mov(scratch2, scratch);
  __ and_(scratch2, Immediate(1 << one_bit_shift));
  __ shr(scratch2, 1);
  __ bind(&round_up);
  __ add(scratch, scratch2);
  __ j(overflow, &largest_value);
  __ bind(&no_round);
  __ shr(scratch, 23);
  __ mov(result_reg, scratch);
  __ jmp(&done, Label::kNear);

  __ bind(&maybe_nan_or_infinity);
  // Check for NaN/Infinity, all other values map to 255
  __ cmp(scratch2, Immediate(HeapNumber::kInfinityOrNanExponent + 1));
  __ j(not_equal, &largest_value, Label::kNear);

  // Check for NaN, which differs from Infinity in that at least one mantissa
  // bit is set.
  __ and_(scratch, HeapNumber::kMantissaMask);
  __ or_(scratch, FieldOperand(input_reg, HeapNumber::kMantissaOffset));
  __ j(not_zero, &zero_result);  // M!=0 --> NaN
  // Infinity -> Fall through to map to 255.

  __ bind(&largest_value);
  __ mov(result_reg, Immediate(255));
  __ jmp(&done, Label::kNear);

  __ bind(&zero_result);
  __ xor_(result_reg, result_reg);
  __ jmp(&done);

  // smi
  __ bind(&is_smi);
  if (!input_reg.is(result_reg)) {
    __ mov(result_reg, input_reg);
  }
  __ SmiUntag(result_reg);
  __ ClampUint8(result_reg);
  __ bind(&done);
}


void LCodeGen::DoCheckPrototypeMaps(LCheckPrototypeMaps* instr) {
  Register reg = ToRegister(instr->temp());

  ZoneList<Handle<JSObject> >* prototypes = instr->prototypes();
  ZoneList<Handle<Map> >* maps = instr->maps();

  ASSERT(prototypes->length() == maps->length());

  if (!instr->hydrogen()->CanOmitPrototypeChecks()) {
    for (int i = 0; i < prototypes->length(); i++) {
      __ LoadHeapObject(reg, prototypes->at(i));
      DoCheckMapCommon(reg, maps->at(i), instr);
    }
  }
}


void LCodeGen::DoAllocate(LAllocate* instr) {
  class DeferredAllocate: public LDeferredCode {
   public:
    DeferredAllocate(LCodeGen* codegen, LAllocate* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() { codegen()->DoDeferredAllocate(instr_); }
    virtual LInstruction* instr() { return instr_; }
   private:
    LAllocate* instr_;
  };

  DeferredAllocate* deferred =
      new(zone()) DeferredAllocate(this, instr);

  Register result = ToRegister(instr->result());
  Register temp = ToRegister(instr->temp());

  // Allocate memory for the object.
  AllocationFlags flags = TAG_OBJECT;
  if (instr->hydrogen()->MustAllocateDoubleAligned()) {
    flags = static_cast<AllocationFlags>(flags | DOUBLE_ALIGNMENT);
  }
  if (instr->hydrogen()->CanAllocateInOldPointerSpace()) {
    ASSERT(!instr->hydrogen()->CanAllocateInOldDataSpace());
    flags = static_cast<AllocationFlags>(flags | PRETENURE_OLD_POINTER_SPACE);
  } else if (instr->hydrogen()->CanAllocateInOldDataSpace()) {
    flags = static_cast<AllocationFlags>(flags | PRETENURE_OLD_DATA_SPACE);
  }

  if (instr->size()->IsConstantOperand()) {
    int32_t size = ToInteger32(LConstantOperand::cast(instr->size()));
    __ Allocate(size, result, temp, no_reg, deferred->entry(), flags);
  } else {
    Register size = ToRegister(instr->size());
    __ Allocate(size, result, temp, no_reg, deferred->entry(), flags);
  }

  __ bind(deferred->exit());
}


void LCodeGen::DoDeferredAllocate(LAllocate* instr) {
  Register result = ToRegister(instr->result());

  // TODO(3095996): Get rid of this. For now, we need to make the
  // result register contain a valid pointer because it is already
  // contained in the register pointer map.
  __ mov(result, Immediate(Smi::FromInt(0)));

  PushSafepointRegistersScope scope(this);
  if (instr->size()->IsRegister()) {
    Register size = ToRegister(instr->size());
    ASSERT(!size.is(result));
    __ SmiTag(ToRegister(instr->size()));
    __ push(size);
  } else {
    int32_t size = ToInteger32(LConstantOperand::cast(instr->size()));
    __ push(Immediate(Smi::FromInt(size)));
  }

  if (instr->hydrogen()->CanAllocateInOldPointerSpace()) {
    ASSERT(!instr->hydrogen()->CanAllocateInOldDataSpace());
    CallRuntimeFromDeferred(
        Runtime::kAllocateInOldPointerSpace, 1, instr, instr->context());
  } else if (instr->hydrogen()->CanAllocateInOldDataSpace()) {
    CallRuntimeFromDeferred(
        Runtime::kAllocateInOldDataSpace, 1, instr, instr->context());
  } else {
    CallRuntimeFromDeferred(
        Runtime::kAllocateInNewSpace, 1, instr, instr->context());
  }
  __ StoreToSafepointRegisterSlot(result, eax);
}


void LCodeGen::DoToFastProperties(LToFastProperties* instr) {
  ASSERT(ToRegister(instr->value()).is(eax));
  __ push(eax);
  CallRuntime(Runtime::kToFastProperties, 1, instr);
}


void LCodeGen::DoRegExpLiteral(LRegExpLiteral* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  Label materialized;
  // Registers will be used as follows:
  // ecx = literals array.
  // ebx = regexp literal.
  // eax = regexp literal clone.
  // esi = context.
  int literal_offset =
      FixedArray::OffsetOfElementAt(instr->hydrogen()->literal_index());
  __ LoadHeapObject(ecx, instr->hydrogen()->literals());
  __ mov(ebx, FieldOperand(ecx, literal_offset));
  __ cmp(ebx, factory()->undefined_value());
  __ j(not_equal, &materialized, Label::kNear);

  // Create regexp literal using runtime function
  // Result will be in eax.
  __ push(ecx);
  __ push(Immediate(Smi::FromInt(instr->hydrogen()->literal_index())));
  __ push(Immediate(instr->hydrogen()->pattern()));
  __ push(Immediate(instr->hydrogen()->flags()));
  CallRuntime(Runtime::kMaterializeRegExpLiteral, 4, instr);
  __ mov(ebx, eax);

  __ bind(&materialized);
  int size = JSRegExp::kSize + JSRegExp::kInObjectFieldCount * kPointerSize;
  Label allocated, runtime_allocate;
  __ Allocate(size, eax, ecx, edx, &runtime_allocate, TAG_OBJECT);
  __ jmp(&allocated);

  __ bind(&runtime_allocate);
  __ push(ebx);
  __ push(Immediate(Smi::FromInt(size)));
  CallRuntime(Runtime::kAllocateInNewSpace, 1, instr);
  __ pop(ebx);

  __ bind(&allocated);
  // Copy the content into the newly allocated memory.
  // (Unroll copy loop once for better throughput).
  for (int i = 0; i < size - kPointerSize; i += 2 * kPointerSize) {
    __ mov(edx, FieldOperand(ebx, i));
    __ mov(ecx, FieldOperand(ebx, i + kPointerSize));
    __ mov(FieldOperand(eax, i), edx);
    __ mov(FieldOperand(eax, i + kPointerSize), ecx);
  }
  if ((size % (2 * kPointerSize)) != 0) {
    __ mov(edx, FieldOperand(ebx, size - kPointerSize));
    __ mov(FieldOperand(eax, size - kPointerSize), edx);
  }
}


void LCodeGen::DoFunctionLiteral(LFunctionLiteral* instr) {
  ASSERT(ToRegister(instr->context()).is(esi));
  // Use the fast case closure allocation code that allocates in new
  // space for nested functions that don't need literals cloning.
  bool pretenure = instr->hydrogen()->pretenure();
  if (!pretenure && instr->hydrogen()->has_no_literals()) {
    FastNewClosureStub stub(instr->hydrogen()->language_mode(),
                            instr->hydrogen()->is_generator());
    __ push(Immediate(instr->hydrogen()->shared_info()));
    CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
  } else {
    __ push(esi);
    __ push(Immediate(instr->hydrogen()->shared_info()));
    __ push(Immediate(pretenure ? factory()->true_value()
                                : factory()->false_value()));
    CallRuntime(Runtime::kNewClosure, 3, instr);
  }
}


void LCodeGen::DoTypeof(LTypeof* instr) {
  LOperand* input = instr->value();
  EmitPushTaggedOperand(input);
  CallRuntime(Runtime::kTypeof, 1, instr);
}


void LCodeGen::DoTypeofIsAndBranch(LTypeofIsAndBranch* instr) {
  Register input = ToRegister(instr->value());
  int true_block = chunk_->LookupDestination(instr->true_block_id());
  int false_block = chunk_->LookupDestination(instr->false_block_id());
  Label* true_label = chunk_->GetAssemblyLabel(true_block);
  Label* false_label = chunk_->GetAssemblyLabel(false_block);

  Condition final_branch_condition =
      EmitTypeofIs(true_label, false_label, input, instr->type_literal());
  if (final_branch_condition != no_condition) {
    EmitBranch(true_block, false_block, final_branch_condition);
  }
}


Condition LCodeGen::EmitTypeofIs(Label* true_label,
                                 Label* false_label,
                                 Register input,
                                 Handle<String> type_name) {
  Condition final_branch_condition = no_condition;
  if (type_name->Equals(heap()->number_string())) {
    __ JumpIfSmi(input, true_label);
    __ cmp(FieldOperand(input, HeapObject::kMapOffset),
           factory()->heap_number_map());
    final_branch_condition = equal;

  } else if (type_name->Equals(heap()->string_string())) {
    __ JumpIfSmi(input, false_label);
    __ CmpObjectType(input, FIRST_NONSTRING_TYPE, input);
    __ j(above_equal, false_label);
    __ test_b(FieldOperand(input, Map::kBitFieldOffset),
              1 << Map::kIsUndetectable);
    final_branch_condition = zero;

  } else if (type_name->Equals(heap()->symbol_string())) {
    __ JumpIfSmi(input, false_label);
    __ CmpObjectType(input, SYMBOL_TYPE, input);
    final_branch_condition = equal;

  } else if (type_name->Equals(heap()->boolean_string())) {
    __ cmp(input, factory()->true_value());
    __ j(equal, true_label);
    __ cmp(input, factory()->false_value());
    final_branch_condition = equal;

  } else if (FLAG_harmony_typeof && type_name->Equals(heap()->null_string())) {
    __ cmp(input, factory()->null_value());
    final_branch_condition = equal;

  } else if (type_name->Equals(heap()->undefined_string())) {
    __ cmp(input, factory()->undefined_value());
    __ j(equal, true_label);
    __ JumpIfSmi(input, false_label);
    // Check for undetectable objects => true.
    __ mov(input, FieldOperand(input, HeapObject::kMapOffset));
    __ test_b(FieldOperand(input, Map::kBitFieldOffset),
              1 << Map::kIsUndetectable);
    final_branch_condition = not_zero;

  } else if (type_name->Equals(heap()->function_string())) {
    STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
    __ JumpIfSmi(input, false_label);
    __ CmpObjectType(input, JS_FUNCTION_TYPE, input);
    __ j(equal, true_label);
    __ CmpInstanceType(input, JS_FUNCTION_PROXY_TYPE);
    final_branch_condition = equal;

  } else if (type_name->Equals(heap()->object_string())) {
    __ JumpIfSmi(input, false_label);
    if (!FLAG_harmony_typeof) {
      __ cmp(input, factory()->null_value());
      __ j(equal, true_label);
    }
    __ CmpObjectType(input, FIRST_NONCALLABLE_SPEC_OBJECT_TYPE, input);
    __ j(below, false_label);
    __ CmpInstanceType(input, LAST_NONCALLABLE_SPEC_OBJECT_TYPE);
    __ j(above, false_label);
    // Check for undetectable objects => false.
    __ test_b(FieldOperand(input, Map::kBitFieldOffset),
              1 << Map::kIsUndetectable);
    final_branch_condition = zero;

  } else {
    __ jmp(false_label);
  }
  return final_branch_condition;
}


void LCodeGen::DoIsConstructCallAndBranch(LIsConstructCallAndBranch* instr) {
  Register temp = ToRegister(instr->temp());
  int true_block = chunk_->LookupDestination(instr->true_block_id());
  int false_block = chunk_->LookupDestination(instr->false_block_id());

  EmitIsConstructCall(temp);
  EmitBranch(true_block, false_block, equal);
}


void LCodeGen::EmitIsConstructCall(Register temp) {
  // Get the frame pointer for the calling frame.
  __ mov(temp, Operand(ebp, StandardFrameConstants::kCallerFPOffset));

  // Skip the arguments adaptor frame if it exists.
  Label check_frame_marker;
  __ cmp(Operand(temp, StandardFrameConstants::kContextOffset),
         Immediate(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
  __ j(not_equal, &check_frame_marker, Label::kNear);
  __ mov(temp, Operand(temp, StandardFrameConstants::kCallerFPOffset));

  // Check the marker in the calling frame.
  __ bind(&check_frame_marker);
  __ cmp(Operand(temp, StandardFrameConstants::kMarkerOffset),
         Immediate(Smi::FromInt(StackFrame::CONSTRUCT)));
}


void LCodeGen::EnsureSpaceForLazyDeopt() {
  if (!info()->IsStub()) {
    // Ensure that we have enough space after the previous lazy-bailout
    // instruction for patching the code here.
    int current_pc = masm()->pc_offset();
    int patch_size = Deoptimizer::patch_size();
    if (current_pc < last_lazy_deopt_pc_ + patch_size) {
      int padding_size = last_lazy_deopt_pc_ + patch_size - current_pc;
      __ Nop(padding_size);
    }
  }
  last_lazy_deopt_pc_ = masm()->pc_offset();
}


void LCodeGen::DoLazyBailout(LLazyBailout* instr) {
  EnsureSpaceForLazyDeopt();
  ASSERT(instr->HasEnvironment());
  LEnvironment* env = instr->environment();
  RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
  safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
}


void LCodeGen::DoDeoptimize(LDeoptimize* instr) {
  if (instr->hydrogen_value()->IsSoftDeoptimize()) {
    SoftDeoptimize(instr->environment());
  } else {
    DeoptimizeIf(no_condition, instr->environment());
  }
}


void LCodeGen::DoDummyUse(LDummyUse* instr) {
  // Nothing to see here, move on!
}


void LCodeGen::DoDeleteProperty(LDeleteProperty* instr) {
  LOperand* obj = instr->object();
  LOperand* key = instr->key();
  __ push(ToOperand(obj));
  EmitPushTaggedOperand(key);
  ASSERT(instr->HasPointerMap());
  LPointerMap* pointers = instr->pointer_map();
  RecordPosition(pointers->position());
  // Create safepoint generator that will also ensure enough space in the
  // reloc info for patching in deoptimization (since this is invoking a
  // builtin)
  SafepointGenerator safepoint_generator(
      this, pointers, Safepoint::kLazyDeopt);
  __ push(Immediate(Smi::FromInt(strict_mode_flag())));
  __ InvokeBuiltin(Builtins::DELETE, CALL_FUNCTION, safepoint_generator);
}


void LCodeGen::DoDeferredStackCheck(LStackCheck* instr) {
  PushSafepointRegistersScope scope(this);
  __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
  __ CallRuntimeSaveDoubles(Runtime::kStackGuard);
  RecordSafepointWithLazyDeopt(
      instr, RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
  ASSERT(instr->HasEnvironment());
  LEnvironment* env = instr->environment();
  safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
}


void LCodeGen::DoStackCheck(LStackCheck* instr) {
  class DeferredStackCheck: public LDeferredCode {
   public:
    DeferredStackCheck(LCodeGen* codegen, LStackCheck* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() { codegen()->DoDeferredStackCheck(instr_); }
    virtual LInstruction* instr() { return instr_; }
   private:
    LStackCheck* instr_;
  };

  ASSERT(instr->HasEnvironment());
  LEnvironment* env = instr->environment();
  // There is no LLazyBailout instruction for stack-checks. We have to
  // prepare for lazy deoptimization explicitly here.
  if (instr->hydrogen()->is_function_entry()) {
    // Perform stack overflow check.
    Label done;
    ExternalReference stack_limit =
        ExternalReference::address_of_stack_limit(isolate());
    __ cmp(esp, Operand::StaticVariable(stack_limit));
    __ j(above_equal, &done, Label::kNear);

    ASSERT(instr->context()->IsRegister());
    ASSERT(ToRegister(instr->context()).is(esi));
    StackCheckStub stub;
    CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
    EnsureSpaceForLazyDeopt();
    __ bind(&done);
    RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
    safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
  } else {
    ASSERT(instr->hydrogen()->is_backwards_branch());
    // Perform stack overflow check if this goto needs it before jumping.
    DeferredStackCheck* deferred_stack_check =
        new(zone()) DeferredStackCheck(this, instr);
    ExternalReference stack_limit =
        ExternalReference::address_of_stack_limit(isolate());
    __ cmp(esp, Operand::StaticVariable(stack_limit));
    __ j(below, deferred_stack_check->entry());
    EnsureSpaceForLazyDeopt();
    __ bind(instr->done_label());
    deferred_stack_check->SetExit(instr->done_label());
    RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
    // Don't record a deoptimization index for the safepoint here.
    // This will be done explicitly when emitting call and the safepoint in
    // the deferred code.
  }
}


void LCodeGen::DoOsrEntry(LOsrEntry* instr) {
  // This is a pseudo-instruction that ensures that the environment here is
  // properly registered for deoptimization and records the assembler's PC
  // offset.
  LEnvironment* environment = instr->environment();
  environment->SetSpilledRegisters(instr->SpilledRegisterArray(),
                                   instr->SpilledDoubleRegisterArray());

  // If the environment were already registered, we would have no way of
  // backpatching it with the spill slot operands.
  ASSERT(!environment->HasBeenRegistered());
  RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
  ASSERT(osr_pc_offset_ == -1);
  osr_pc_offset_ = masm()->pc_offset();
}


void LCodeGen::DoIn(LIn* instr) {
  LOperand* obj = instr->object();
  LOperand* key = instr->key();
  EmitPushTaggedOperand(key);
  EmitPushTaggedOperand(obj);
  ASSERT(instr->HasPointerMap());
  LPointerMap* pointers = instr->pointer_map();
  RecordPosition(pointers->position());
  SafepointGenerator safepoint_generator(
      this, pointers, Safepoint::kLazyDeopt);
  __ InvokeBuiltin(Builtins::IN, CALL_FUNCTION, safepoint_generator);
}


void LCodeGen::DoForInPrepareMap(LForInPrepareMap* instr) {
  __ cmp(eax, isolate()->factory()->undefined_value());
  DeoptimizeIf(equal, instr->environment());

  __ cmp(eax, isolate()->factory()->null_value());
  DeoptimizeIf(equal, instr->environment());

  __ test(eax, Immediate(kSmiTagMask));
  DeoptimizeIf(zero, instr->environment());

  STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
  __ CmpObjectType(eax, LAST_JS_PROXY_TYPE, ecx);
  DeoptimizeIf(below_equal, instr->environment());

  Label use_cache, call_runtime;
  __ CheckEnumCache(&call_runtime);

  __ mov(eax, FieldOperand(eax, HeapObject::kMapOffset));
  __ jmp(&use_cache, Label::kNear);

  // Get the set of properties to enumerate.
  __ bind(&call_runtime);
  __ push(eax);
  CallRuntime(Runtime::kGetPropertyNamesFast, 1, instr);

  __ cmp(FieldOperand(eax, HeapObject::kMapOffset),
         isolate()->factory()->meta_map());
  DeoptimizeIf(not_equal, instr->environment());
  __ bind(&use_cache);
}


void LCodeGen::DoForInCacheArray(LForInCacheArray* instr) {
  Register map = ToRegister(instr->map());
  Register result = ToRegister(instr->result());
  Label load_cache, done;
  __ EnumLength(result, map);
  __ cmp(result, Immediate(Smi::FromInt(0)));
  __ j(not_equal, &load_cache);
  __ mov(result, isolate()->factory()->empty_fixed_array());
  __ jmp(&done);

  __ bind(&load_cache);
  __ LoadInstanceDescriptors(map, result);
  __ mov(result,
         FieldOperand(result, DescriptorArray::kEnumCacheOffset));
  __ mov(result,
         FieldOperand(result, FixedArray::SizeFor(instr->idx())));
  __ bind(&done);
  __ test(result, result);
  DeoptimizeIf(equal, instr->environment());
}


void LCodeGen::DoCheckMapValue(LCheckMapValue* instr) {
  Register object = ToRegister(instr->value());
  __ cmp(ToRegister(instr->map()),
         FieldOperand(object, HeapObject::kMapOffset));
  DeoptimizeIf(not_equal, instr->environment());
}


void LCodeGen::DoLoadFieldByIndex(LLoadFieldByIndex* instr) {
  Register object = ToRegister(instr->object());
  Register index = ToRegister(instr->index());

  Label out_of_object, done;
  __ cmp(index, Immediate(0));
  __ j(less, &out_of_object);
  __ mov(object, FieldOperand(object,
                              index,
                              times_half_pointer_size,
                              JSObject::kHeaderSize));
  __ jmp(&done, Label::kNear);

  __ bind(&out_of_object);
  __ mov(object, FieldOperand(object, JSObject::kPropertiesOffset));
  __ neg(index);
  // Index is now equal to out of object property index plus 1.
  __ mov(object, FieldOperand(object,
                              index,
                              times_half_pointer_size,
                              FixedArray::kHeaderSize - kPointerSize));
  __ bind(&done);
}


#undef __

} }  // namespace v8::internal

#endif  // V8_TARGET_ARCH_IA32