lithium-codegen-x64.cc

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// Copyright 2013 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
#include "src/v8.h"
 
#if V8_TARGET_ARCH_X64
 
#include "src/base/bits.h"
#include "src/code-factory.h"
#include "src/code-stubs.h"
#include "src/hydrogen-osr.h"
#include "src/ic/ic.h"
#include "src/ic/stub-cache.h"
#include "src/x64/lithium-codegen-x64.h"
 
namespace v8 {
namespace internal {
 
 
// When invoking builtins, we need to record the safepoint in the middle of
// the invoke instruction sequence generated by the macro assembler.
class SafepointGenerator FINAL : 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 OVERRIDE {}
 
  virtual void AfterCall() const OVERRIDE {
    codegen_->RecordSafepoint(pointers_, deopt_mode_);
  }
 
 private:
  LCodeGen* codegen_;
  LPointerMap* pointers_;
  Safepoint::DeoptMode deopt_mode_;
};
 
 
#define __ masm()->
 
bool LCodeGen::GenerateCode() {
  LPhase phase("Z_Code generation", chunk());
  DCHECK(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);
 
  return GeneratePrologue() &&
      GenerateBody() &&
      GenerateDeferredCode() &&
      GenerateJumpTable() &&
      GenerateSafepointTable();
}
 
 
void LCodeGen::FinishCode(Handle<Code> code) {
  DCHECK(is_done());
  code->set_stack_slots(GetStackSlotCount());
  code->set_safepoint_table_offset(safepoints_.GetCodeOffset());
  if (code->is_optimized_code()) RegisterWeakObjectsInOptimizedCode(code);
  PopulateDeoptimizationData(code);
}
 
 
#ifdef _MSC_VER
void LCodeGen::MakeSureStackPagesMapped(int offset) {
  const int kPageSize = 4 * KB;
  for (offset -= kPageSize; offset > 0; offset -= kPageSize) {
    __ movp(Operand(rsp, offset), rax);
  }
}
#endif
 
 
void LCodeGen::SaveCallerDoubles() {
  DCHECK(info()->saves_caller_doubles());
  DCHECK(NeedsEagerFrame());
  Comment(";;; Save clobbered callee double registers");
  int count = 0;
  BitVector* doubles = chunk()->allocated_double_registers();
  BitVector::Iterator save_iterator(doubles);
  while (!save_iterator.Done()) {
    __ movsd(MemOperand(rsp, count * kDoubleSize),
             XMMRegister::FromAllocationIndex(save_iterator.Current()));
    save_iterator.Advance();
    count++;
  }
}
 
 
void LCodeGen::RestoreCallerDoubles() {
  DCHECK(info()->saves_caller_doubles());
  DCHECK(NeedsEagerFrame());
  Comment(";;; Restore clobbered callee double registers");
  BitVector* doubles = chunk()->allocated_double_registers();
  BitVector::Iterator save_iterator(doubles);
  int count = 0;
  while (!save_iterator.Done()) {
    __ movsd(XMMRegister::FromAllocationIndex(save_iterator.Current()),
             MemOperand(rsp, count * kDoubleSize));
    save_iterator.Advance();
    count++;
  }
}
 
 
bool LCodeGen::GeneratePrologue() {
  DCHECK(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
 
    // Sloppy mode functions need to replace the receiver with the global proxy
    // when called as functions (without an explicit receiver object).
    if (info_->this_has_uses() &&
        info_->strict_mode() == SLOPPY &&
        !info_->is_native()) {
      Label ok;
      StackArgumentsAccessor args(rsp, scope()->num_parameters());
      __ movp(rcx, args.GetReceiverOperand());
 
      __ CompareRoot(rcx, Heap::kUndefinedValueRootIndex);
      __ j(not_equal, &ok, Label::kNear);
 
      __ movp(rcx, GlobalObjectOperand());
      __ movp(rcx, FieldOperand(rcx, GlobalObject::kGlobalProxyOffset));
 
      __ movp(args.GetReceiverOperand(), rcx);
 
      __ bind(&ok);
    }
  }
 
  info()->set_prologue_offset(masm_->pc_offset());
  if (NeedsEagerFrame()) {
    DCHECK(!frame_is_built_);
    frame_is_built_ = true;
    if (info()->IsStub()) {
      __ StubPrologue();
    } else {
      __ Prologue(info()->IsCodePreAgingActive());
    }
    info()->AddNoFrameRange(0, masm_->pc_offset());
  }
 
  // Reserve space for the stack slots needed by the code.
  int slots = GetStackSlotCount();
  if (slots > 0) {
    if (FLAG_debug_code) {
      __ subp(rsp, Immediate(slots * kPointerSize));
#ifdef _MSC_VER
      MakeSureStackPagesMapped(slots * kPointerSize);
#endif
      __ Push(rax);
      __ Set(rax, slots);
      __ Set(kScratchRegister, kSlotsZapValue);
      Label loop;
      __ bind(&loop);
      __ movp(MemOperand(rsp, rax, times_pointer_size, 0),
              kScratchRegister);
      __ decl(rax);
      __ j(not_zero, &loop);
      __ Pop(rax);
    } else {
      __ subp(rsp, Immediate(slots * kPointerSize));
#ifdef _MSC_VER
      MakeSureStackPagesMapped(slots * kPointerSize);
#endif
    }
 
    if (info()->saves_caller_doubles()) {
      SaveCallerDoubles();
    }
  }
 
  // Possibly allocate a local context.
  int heap_slots = info_->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
  if (heap_slots > 0) {
    Comment(";;; Allocate local context");
    bool need_write_barrier = true;
    // Argument to NewContext is the function, which is still in rdi.
    if (heap_slots <= FastNewContextStub::kMaximumSlots) {
      FastNewContextStub stub(isolate(), heap_slots);
      __ CallStub(&stub);
      // Result of FastNewContextStub is always in new space.
      need_write_barrier = false;
    } else {
      __ Push(rdi);
      __ CallRuntime(Runtime::kNewFunctionContext, 1);
    }
    RecordSafepoint(Safepoint::kNoLazyDeopt);
    // Context is returned in rax.  It replaces the context passed to us.
    // It's saved in the stack and kept live in rsi.
    __ movp(rsi, rax);
    __ movp(Operand(rbp, StandardFrameConstants::kContextOffset), rax);
 
    // Copy any necessary parameters into the context.
    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.
        __ movp(rax, Operand(rbp, parameter_offset));
        // Store it in the context.
        int context_offset = Context::SlotOffset(var->index());
        __ movp(Operand(rsi, context_offset), rax);
        // Update the write barrier. This clobbers rax and rbx.
        if (need_write_barrier) {
          __ RecordWriteContextSlot(rsi, context_offset, rax, rbx, kSaveFPRegs);
        } else if (FLAG_debug_code) {
          Label done;
          __ JumpIfInNewSpace(rsi, rax, &done, Label::kNear);
          __ Abort(kExpectedNewSpaceObject);
          __ bind(&done);
        }
      }
    }
    Comment(";;; End allocate local context");
  }
 
  // Trace the call.
  if (FLAG_trace && info()->IsOptimizing()) {
    __ CallRuntime(Runtime::kTraceEnter, 0);
  }
  return !is_aborted();
}
 
 
void LCodeGen::GenerateOsrPrologue() {
  // Generate the OSR entry prologue at the first unknown OSR value, or if there
  // are none, at the OSR entrypoint instruction.
  if (osr_pc_offset_ >= 0) return;
 
  osr_pc_offset_ = masm()->pc_offset();
 
  // Adjust the frame size, subsuming the unoptimized frame into the
  // optimized frame.
  int slots = GetStackSlotCount() - graph()->osr()->UnoptimizedFrameSlots();
  DCHECK(slots >= 0);
  __ subp(rsp, Immediate(slots * kPointerSize));
}
 
 
void LCodeGen::GenerateBodyInstructionPre(LInstruction* instr) {
  if (instr->IsCall()) {
    EnsureSpaceForLazyDeopt(Deoptimizer::patch_size());
  }
  if (!instr->IsLazyBailout() && !instr->IsGap()) {
    safepoints_.BumpLastLazySafepointIndex();
  }
}
 
 
void LCodeGen::GenerateBodyInstructionPost(LInstruction* instr) {
  if (FLAG_debug_code && FLAG_enable_slow_asserts && instr->HasResult() &&
      instr->hydrogen_value()->representation().IsInteger32() &&
      instr->result()->IsRegister()) {
    __ AssertZeroExtended(ToRegister(instr->result()));
  }
 
  if (instr->HasResult() && instr->MustSignExtendResult(chunk())) {
    // We sign extend the dehoisted key at the definition point when the pointer
    // size is 64-bit. For x32 port, we sign extend the dehoisted key at the use
    // points and MustSignExtendResult is always false. We can't use
    // STATIC_ASSERT here as the pointer size is 32-bit for x32.
    DCHECK(kPointerSize == kInt64Size);
    if (instr->result()->IsRegister()) {
      Register result_reg = ToRegister(instr->result());
      __ movsxlq(result_reg, result_reg);
    } else {
      // Sign extend the 32bit result in the stack slots.
      DCHECK(instr->result()->IsStackSlot());
      Operand src = ToOperand(instr->result());
      __ movsxlq(kScratchRegister, src);
      __ movq(src, kScratchRegister);
    }
  }
}
 
 
bool LCodeGen::GenerateJumpTable() {
  Label needs_frame;
  if (jump_table_.length() > 0) {
    Comment(";;; -------------------- Jump table --------------------");
  }
  for (int i = 0; i < jump_table_.length(); i++) {
    Deoptimizer::JumpTableEntry* table_entry = &jump_table_[i];
    __ bind(&table_entry->label);
    Address entry = table_entry->address;
    DeoptComment(table_entry->reason);
    if (table_entry->needs_frame) {
      DCHECK(!info()->saves_caller_doubles());
      __ Move(kScratchRegister, ExternalReference::ForDeoptEntry(entry));
      if (needs_frame.is_bound()) {
        __ jmp(&needs_frame);
      } else {
        __ bind(&needs_frame);
        __ movp(rsi, MemOperand(rbp, StandardFrameConstants::kContextOffset));
        __ pushq(rbp);
        __ movp(rbp, rsp);
        __ Push(rsi);
        // 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.
        DCHECK(info()->IsStub());
        __ Move(rsi, Smi::FromInt(StackFrame::STUB));
        __ Push(rsi);
        __ movp(rsi, MemOperand(rsp, kPointerSize));
        __ call(kScratchRegister);
      }
    } else {
      if (info()->saves_caller_doubles()) {
        DCHECK(info()->IsStub());
        RestoreCallerDoubles();
      }
      __ call(entry, RelocInfo::RUNTIME_ENTRY);
    }
  }
  return !is_aborted();
}
 
 
bool LCodeGen::GenerateDeferredCode() {
  DCHECK(is_generating());
  if (deferred_.length() > 0) {
    for (int i = 0; !is_aborted() && i < deferred_.length(); i++) {
      LDeferredCode* code = deferred_[i];
 
      HValue* value =
          instructions_->at(code->instruction_index())->hydrogen_value();
      RecordAndWritePosition(
          chunk()->graph()->SourcePositionToScriptPosition(value->position()));
 
      Comment(";;; <@%d,#%d> "
              "-------------------- Deferred %s --------------------",
              code->instruction_index(),
              code->instr()->hydrogen_value()->id(),
              code->instr()->Mnemonic());
      __ bind(code->entry());
      if (NeedsDeferredFrame()) {
        Comment(";;; Build frame");
        DCHECK(!frame_is_built_);
        DCHECK(info()->IsStub());
        frame_is_built_ = true;
        // Build the frame in such a way that esi isn't trashed.
        __ pushq(rbp);  // Caller's frame pointer.
        __ Push(Operand(rbp, StandardFrameConstants::kContextOffset));
        __ Push(Smi::FromInt(StackFrame::STUB));
        __ leap(rbp, Operand(rsp, 2 * kPointerSize));
        Comment(";;; Deferred code");
      }
      code->Generate();
      if (NeedsDeferredFrame()) {
        __ bind(code->done());
        Comment(";;; Destroy frame");
        DCHECK(frame_is_built_);
        frame_is_built_ = false;
        __ movp(rsp, rbp);
        __ popq(rbp);
      }
      __ 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() {
  DCHECK(is_done());
  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);
}
 
 
Register LCodeGen::ToRegister(LOperand* op) const {
  DCHECK(op->IsRegister());
  return ToRegister(op->index());
}
 
 
XMMRegister LCodeGen::ToDoubleRegister(LOperand* op) const {
  DCHECK(op->IsDoubleRegister());
  return ToDoubleRegister(op->index());
}
 
 
bool LCodeGen::IsInteger32Constant(LConstantOperand* op) const {
  return chunk_->LookupLiteralRepresentation(op).IsSmiOrInteger32();
}
 
 
bool LCodeGen::IsDehoistedKeyConstant(LConstantOperand* op) const {
  return op->IsConstantOperand() &&
      chunk_->IsDehoistedKey(chunk_->LookupConstant(op));
}
 
 
bool LCodeGen::IsSmiConstant(LConstantOperand* op) const {
  return chunk_->LookupLiteralRepresentation(op).IsSmi();
}
 
 
int32_t LCodeGen::ToInteger32(LConstantOperand* op) const {
  return ToRepresentation(op, Representation::Integer32());
}
 
 
int32_t LCodeGen::ToRepresentation(LConstantOperand* op,
                                   const Representation& r) const {
  HConstant* constant = chunk_->LookupConstant(op);
  int32_t value = constant->Integer32Value();
  if (r.IsInteger32()) return value;
  DCHECK(SmiValuesAre31Bits() && r.IsSmiOrTagged());
  return static_cast<int32_t>(reinterpret_cast<intptr_t>(Smi::FromInt(value)));
}
 
 
Smi* LCodeGen::ToSmi(LConstantOperand* op) const {
  HConstant* constant = chunk_->LookupConstant(op);
  return Smi::FromInt(constant->Integer32Value());
}
 
 
double LCodeGen::ToDouble(LConstantOperand* op) const {
  HConstant* constant = chunk_->LookupConstant(op);
  DCHECK(constant->HasDoubleValue());
  return constant->DoubleValue();
}
 
 
ExternalReference LCodeGen::ToExternalReference(LConstantOperand* op) const {
  HConstant* constant = chunk_->LookupConstant(op);
  DCHECK(constant->HasExternalReferenceValue());
  return constant->ExternalReferenceValue();
}
 
 
Handle<Object> LCodeGen::ToHandle(LConstantOperand* op) const {
  HConstant* constant = chunk_->LookupConstant(op);
  DCHECK(chunk_->LookupLiteralRepresentation(op).IsSmiOrTagged());
  return constant->handle(isolate());
}
 
 
static int ArgumentsOffsetWithoutFrame(int index) {
  DCHECK(index < 0);
  return -(index + 1) * kPointerSize + kPCOnStackSize;
}
 
 
Operand LCodeGen::ToOperand(LOperand* op) const {
  // Does not handle registers. In X64 assembler, plain registers are not
  // representable as an Operand.
  DCHECK(op->IsStackSlot() || op->IsDoubleStackSlot());
  if (NeedsEagerFrame()) {
    return Operand(rbp, StackSlotOffset(op->index()));
  } else {
    // Retrieve parameter without eager stack-frame relative to the
    // stack-pointer.
    return Operand(rsp, ArgumentsOffsetWithoutFrame(op->index()));
  }
}
 
 
void LCodeGen::WriteTranslation(LEnvironment* environment,
                                Translation* translation) {
  if (environment == NULL) return;
 
  // The translation includes one command per value in the environment.
  int translation_size = environment->translation_size();
  // The output frame height does not include the parameters.
  int height = translation_size - environment->parameter_count();
 
  WriteTranslation(environment->outer(), translation);
  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:
      DCHECK(translation_size == 1);
      DCHECK(height == 0);
      translation->BeginGetterStubFrame(closure_id);
      break;
    case JS_SETTER:
      DCHECK(translation_size == 2);
      DCHECK(height == 0);
      translation->BeginSetterStubFrame(closure_id);
      break;
    case ARGUMENTS_ADAPTOR:
      translation->BeginArgumentsAdaptorFrame(closure_id, translation_size);
      break;
    case STUB:
      translation->BeginCompiledStubFrame();
      break;
  }
 
  int object_index = 0;
  int dematerialized_index = 0;
  for (int i = 0; i < translation_size; ++i) {
    LOperand* value = environment->values()->at(i);
    AddToTranslation(environment,
                     translation,
                     value,
                     environment->HasTaggedValueAt(i),
                     environment->HasUint32ValueAt(i),
                     &object_index,
                     &dematerialized_index);
  }
}
 
 
void LCodeGen::AddToTranslation(LEnvironment* environment,
                                Translation* translation,
                                LOperand* op,
                                bool is_tagged,
                                bool is_uint32,
                                int* object_index_pointer,
                                int* dematerialized_index_pointer) {
  if (op == LEnvironment::materialization_marker()) {
    int object_index = (*object_index_pointer)++;
    if (environment->ObjectIsDuplicateAt(object_index)) {
      int dupe_of = environment->ObjectDuplicateOfAt(object_index);
      translation->DuplicateObject(dupe_of);
      return;
    }
    int object_length = environment->ObjectLengthAt(object_index);
    if (environment->ObjectIsArgumentsAt(object_index)) {
      translation->BeginArgumentsObject(object_length);
    } else {
      translation->BeginCapturedObject(object_length);
    }
    int dematerialized_index = *dematerialized_index_pointer;
    int env_offset = environment->translation_size() + dematerialized_index;
    *dematerialized_index_pointer += object_length;
    for (int i = 0; i < object_length; ++i) {
      LOperand* value = environment->values()->at(env_offset + i);
      AddToTranslation(environment,
                       translation,
                       value,
                       environment->HasTaggedValueAt(env_offset + i),
                       environment->HasUint32ValueAt(env_offset + i),
                       object_index_pointer,
                       dematerialized_index_pointer);
    }
    return;
  }
 
  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->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(isolate()));
    translation->StoreLiteral(src_index);
  } else {
    UNREACHABLE();
  }
}
 
 
void LCodeGen::CallCodeGeneric(Handle<Code> code,
                               RelocInfo::Mode mode,
                               LInstruction* instr,
                               SafepointMode safepoint_mode,
                               int argc) {
  DCHECK(instr != NULL);
  __ call(code, mode);
  RecordSafepointWithLazyDeopt(instr, safepoint_mode, argc);
 
  // 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, 0);
}
 
 
void LCodeGen::CallRuntime(const Runtime::Function* function,
                           int num_arguments,
                           LInstruction* instr,
                           SaveFPRegsMode save_doubles) {
  DCHECK(instr != NULL);
  DCHECK(instr->HasPointerMap());
 
  __ CallRuntime(function, num_arguments, save_doubles);
 
  RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT, 0);
}
 
 
void LCodeGen::LoadContextFromDeferred(LOperand* context) {
  if (context->IsRegister()) {
    if (!ToRegister(context).is(rsi)) {
      __ movp(rsi, ToRegister(context));
    }
  } else if (context->IsStackSlot()) {
    __ movp(rsi, ToOperand(context));
  } else if (context->IsConstantOperand()) {
    HConstant* constant =
        chunk_->LookupConstant(LConstantOperand::cast(context));
    __ Move(rsi, Handle<Object>::cast(constant->handle(isolate())));
  } 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);
}
 
 
void LCodeGen::RegisterEnvironmentForDeoptimization(LEnvironment* environment,
                                                    Safepoint::DeoptMode mode) {
  environment->set_has_been_used();
  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;
    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);
    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, environment->zone());
  }
}
 
 
void LCodeGen::DeoptimizeIf(Condition cc, LInstruction* instr,
                            const char* detail,
                            Deoptimizer::BailoutType bailout_type) {
  LEnvironment* environment = instr->environment();
  RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
  DCHECK(environment->HasBeenRegistered());
  int id = environment->deoptimization_index();
  DCHECK(info()->IsOptimizing() || info()->IsStub());
  Address entry =
      Deoptimizer::GetDeoptimizationEntry(isolate(), id, bailout_type);
  if (entry == NULL) {
    Abort(kBailoutWasNotPrepared);
    return;
  }
 
  if (DeoptEveryNTimes()) {
    ExternalReference count = ExternalReference::stress_deopt_count(isolate());
    Label no_deopt;
    __ pushfq();
    __ pushq(rax);
    Operand count_operand = masm()->ExternalOperand(count, kScratchRegister);
    __ movl(rax, count_operand);
    __ subl(rax, Immediate(1));
    __ j(not_zero, &no_deopt, Label::kNear);
    if (FLAG_trap_on_deopt) __ int3();
    __ movl(rax, Immediate(FLAG_deopt_every_n_times));
    __ movl(count_operand, rax);
    __ popq(rax);
    __ popfq();
    DCHECK(frame_is_built_);
    __ call(entry, RelocInfo::RUNTIME_ENTRY);
    __ bind(&no_deopt);
    __ movl(count_operand, rax);
    __ popq(rax);
    __ popfq();
  }
 
  if (info()->ShouldTrapOnDeopt()) {
    Label done;
    if (cc != no_condition) {
      __ j(NegateCondition(cc), &done, Label::kNear);
    }
    __ int3();
    __ bind(&done);
  }
 
  Deoptimizer::Reason reason(instr->hydrogen_value()->position().raw(),
                             instr->Mnemonic(), detail);
  DCHECK(info()->IsStub() || frame_is_built_);
  // Go through jump table if we need to handle condition, build frame, or
  // restore caller doubles.
  if (cc == no_condition && frame_is_built_ &&
      !info()->saves_caller_doubles()) {
    DeoptComment(reason);
    __ call(entry, RelocInfo::RUNTIME_ENTRY);
  } else {
    Deoptimizer::JumpTableEntry table_entry(entry, reason, bailout_type,
                                            !frame_is_built_);
    // We often have several deopts to the same entry, reuse the last
    // jump entry if this is the case.
    if (jump_table_.is_empty() ||
        !table_entry.IsEquivalentTo(jump_table_.last())) {
      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, LInstruction* instr,
                            const char* detail) {
  Deoptimizer::BailoutType bailout_type = info()->IsStub()
      ? Deoptimizer::LAZY
      : Deoptimizer::EAGER;
  DeoptimizeIf(cc, instr, detail, bailout_type);
}
 
 
void LCodeGen::PopulateDeoptimizationData(Handle<Code> code) {
  int length = deoptimizations_.length();
  if (length == 0) return;
  Handle<DeoptimizationInputData> data =
      DeoptimizationInputData::New(isolate(), length, TENURED);
 
  Handle<ByteArray> translations =
      translations_.CreateByteArray(isolate()->factory());
  data->SetTranslationByteArray(*translations);
  data->SetInlinedFunctionCount(Smi::FromInt(inlined_function_count_));
  data->SetOptimizationId(Smi::FromInt(info_->optimization_id()));
  if (info_->IsOptimizing()) {
    // Reference to shared function info does not change between phases.
    AllowDeferredHandleDereference allow_handle_dereference;
    data->SetSharedFunctionInfo(*info_->shared_info());
  } else {
    data->SetSharedFunctionInfo(Smi::FromInt(0));
  }
 
  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() {
  DCHECK(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, int argc) {
  if (safepoint_mode == RECORD_SIMPLE_SAFEPOINT) {
    RecordSafepoint(instr->pointer_map(), Safepoint::kLazyDeopt);
  } else {
    DCHECK(safepoint_mode == RECORD_SAFEPOINT_WITH_REGISTERS);
    RecordSafepointWithRegisters(
        instr->pointer_map(), argc, Safepoint::kLazyDeopt);
  }
}
 
 
void LCodeGen::RecordSafepoint(
    LPointerMap* pointers,
    Safepoint::Kind kind,
    int arguments,
    Safepoint::DeoptMode deopt_mode) {
  DCHECK(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 deopt_mode) {
  RecordSafepoint(pointers, Safepoint::kSimple, 0, deopt_mode);
}
 
 
void LCodeGen::RecordSafepoint(Safepoint::DeoptMode deopt_mode) {
  LPointerMap empty_pointers(zone());
  RecordSafepoint(&empty_pointers, deopt_mode);
}
 
 
void LCodeGen::RecordSafepointWithRegisters(LPointerMap* pointers,
                                            int arguments,
                                            Safepoint::DeoptMode deopt_mode) {
  RecordSafepoint(pointers, Safepoint::kWithRegisters, arguments, deopt_mode);
}
 
 
void LCodeGen::RecordAndWritePosition(int position) {
  if (position == RelocInfo::kNoPosition) return;
  masm()->positions_recorder()->RecordPosition(position);
  masm()->positions_recorder()->WriteRecordedPositions();
}
 
 
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) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  DCHECK(ToRegister(instr->result()).is(rax));
  switch (instr->hydrogen()->major_key()) {
    case CodeStub::RegExpExec: {
      RegExpExecStub stub(isolate());
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
      break;
    }
    case CodeStub::SubString: {
      SubStringStub stub(isolate());
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
      break;
    }
    case CodeStub::StringCompare: {
      StringCompareStub stub(isolate());
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
      break;
    }
    default:
      UNREACHABLE();
  }
}
 
 
void LCodeGen::DoUnknownOSRValue(LUnknownOSRValue* instr) {
  GenerateOsrPrologue();
}
 
 
void LCodeGen::DoModByPowerOf2I(LModByPowerOf2I* instr) {
  Register dividend = ToRegister(instr->dividend());
  int32_t divisor = instr->divisor();
  DCHECK(dividend.is(ToRegister(instr->result())));
 
  // Theoretically, a variation of the branch-free code for integer division by
  // a power of 2 (calculating the remainder via an additional multiplication
  // (which gets simplified to an 'and') and subtraction) should be faster, and
  // this is exactly what GCC and clang emit. Nevertheless, benchmarks seem to
  // indicate that positive dividends are heavily favored, so the branching
  // version performs better.
  HMod* hmod = instr->hydrogen();
  int32_t mask = divisor < 0 ? -(divisor + 1) : (divisor - 1);
  Label dividend_is_not_negative, done;
  if (hmod->CheckFlag(HValue::kLeftCanBeNegative)) {
    __ testl(dividend, dividend);
    __ j(not_sign, &dividend_is_not_negative, Label::kNear);
    // Note that this is correct even for kMinInt operands.
    __ negl(dividend);
    __ andl(dividend, Immediate(mask));
    __ negl(dividend);
    if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
      DeoptimizeIf(zero, instr, "minus zero");
    }
    __ jmp(&done, Label::kNear);
  }
 
  __ bind(&dividend_is_not_negative);
  __ andl(dividend, Immediate(mask));
  __ bind(&done);
}
 
 
void LCodeGen::DoModByConstI(LModByConstI* instr) {
  Register dividend = ToRegister(instr->dividend());
  int32_t divisor = instr->divisor();
  DCHECK(ToRegister(instr->result()).is(rax));
 
  if (divisor == 0) {
    DeoptimizeIf(no_condition, instr, "division by zero");
    return;
  }
 
  __ TruncatingDiv(dividend, Abs(divisor));
  __ imull(rdx, rdx, Immediate(Abs(divisor)));
  __ movl(rax, dividend);
  __ subl(rax, rdx);
 
  // Check for negative zero.
  HMod* hmod = instr->hydrogen();
  if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
    Label remainder_not_zero;
    __ j(not_zero, &remainder_not_zero, Label::kNear);
    __ cmpl(dividend, Immediate(0));
    DeoptimizeIf(less, instr, "minus zero");
    __ bind(&remainder_not_zero);
  }
}
 
 
void LCodeGen::DoModI(LModI* instr) {
  HMod* hmod = instr->hydrogen();
 
  Register left_reg = ToRegister(instr->left());
  DCHECK(left_reg.is(rax));
  Register right_reg = ToRegister(instr->right());
  DCHECK(!right_reg.is(rax));
  DCHECK(!right_reg.is(rdx));
  Register result_reg = ToRegister(instr->result());
  DCHECK(result_reg.is(rdx));
 
  Label done;
  // Check for x % 0, idiv would signal a divide error. We have to
  // deopt in this case because we can't return a NaN.
  if (hmod->CheckFlag(HValue::kCanBeDivByZero)) {
    __ testl(right_reg, right_reg);
    DeoptimizeIf(zero, instr, "division by zero");
  }
 
  // Check for kMinInt % -1, idiv would signal a divide error. We
  // have to deopt if we care about -0, because we can't return that.
  if (hmod->CheckFlag(HValue::kCanOverflow)) {
    Label no_overflow_possible;
    __ cmpl(left_reg, Immediate(kMinInt));
    __ j(not_zero, &no_overflow_possible, Label::kNear);
    __ cmpl(right_reg, Immediate(-1));
    if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
      DeoptimizeIf(equal, instr, "minus zero");
    } else {
      __ j(not_equal, &no_overflow_possible, Label::kNear);
      __ Set(result_reg, 0);
      __ jmp(&done, Label::kNear);
    }
    __ bind(&no_overflow_possible);
  }
 
  // Sign extend dividend in eax into edx:eax, since we are using only the low
  // 32 bits of the values.
  __ cdq();
 
  // If we care about -0, test if the dividend is <0 and the result is 0.
  if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
    Label positive_left;
    __ testl(left_reg, left_reg);
    __ j(not_sign, &positive_left, Label::kNear);
    __ idivl(right_reg);
    __ testl(result_reg, result_reg);
    DeoptimizeIf(zero, instr, "minus zero");
    __ jmp(&done, Label::kNear);
    __ bind(&positive_left);
  }
  __ idivl(right_reg);
  __ bind(&done);
}
 
 
void LCodeGen::DoFlooringDivByPowerOf2I(LFlooringDivByPowerOf2I* instr) {
  Register dividend = ToRegister(instr->dividend());
  int32_t divisor = instr->divisor();
  DCHECK(dividend.is(ToRegister(instr->result())));
 
  // If the divisor is positive, things are easy: There can be no deopts and we
  // can simply do an arithmetic right shift.
  if (divisor == 1) return;
  int32_t shift = WhichPowerOf2Abs(divisor);
  if (divisor > 1) {
    __ sarl(dividend, Immediate(shift));
    return;
  }
 
  // If the divisor is negative, we have to negate and handle edge cases.
  __ negl(dividend);
  if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
    DeoptimizeIf(zero, instr, "minus zero");
  }
 
  // Dividing by -1 is basically negation, unless we overflow.
  if (divisor == -1) {
    if (instr->hydrogen()->CheckFlag(HValue::kLeftCanBeMinInt)) {
      DeoptimizeIf(overflow, instr, "overflow");
    }
    return;
  }
 
  // If the negation could not overflow, simply shifting is OK.
  if (!instr->hydrogen()->CheckFlag(HValue::kLeftCanBeMinInt)) {
    __ sarl(dividend, Immediate(shift));
    return;
  }
 
  Label not_kmin_int, done;
  __ j(no_overflow, &not_kmin_int, Label::kNear);
  __ movl(dividend, Immediate(kMinInt / divisor));
  __ jmp(&done, Label::kNear);
  __ bind(&not_kmin_int);
  __ sarl(dividend, Immediate(shift));
  __ bind(&done);
}
 
 
void LCodeGen::DoFlooringDivByConstI(LFlooringDivByConstI* instr) {
  Register dividend = ToRegister(instr->dividend());
  int32_t divisor = instr->divisor();
  DCHECK(ToRegister(instr->result()).is(rdx));
 
  if (divisor == 0) {
    DeoptimizeIf(no_condition, instr, "division by zero");
    return;
  }
 
  // Check for (0 / -x) that will produce negative zero.
  HMathFloorOfDiv* hdiv = instr->hydrogen();
  if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
    __ testl(dividend, dividend);
    DeoptimizeIf(zero, instr, "minus zero");
  }
 
  // Easy case: We need no dynamic check for the dividend and the flooring
  // division is the same as the truncating division.
  if ((divisor > 0 && !hdiv->CheckFlag(HValue::kLeftCanBeNegative)) ||
      (divisor < 0 && !hdiv->CheckFlag(HValue::kLeftCanBePositive))) {
    __ TruncatingDiv(dividend, Abs(divisor));
    if (divisor < 0) __ negl(rdx);
    return;
  }
 
  // In the general case we may need to adjust before and after the truncating
  // division to get a flooring division.
  Register temp = ToRegister(instr->temp3());
  DCHECK(!temp.is(dividend) && !temp.is(rax) && !temp.is(rdx));
  Label needs_adjustment, done;
  __ cmpl(dividend, Immediate(0));
  __ j(divisor > 0 ? less : greater, &needs_adjustment, Label::kNear);
  __ TruncatingDiv(dividend, Abs(divisor));
  if (divisor < 0) __ negl(rdx);
  __ jmp(&done, Label::kNear);
  __ bind(&needs_adjustment);
  __ leal(temp, Operand(dividend, divisor > 0 ? 1 : -1));
  __ TruncatingDiv(temp, Abs(divisor));
  if (divisor < 0) __ negl(rdx);
  __ decl(rdx);
  __ bind(&done);
}
 
 
// TODO(svenpanne) Refactor this to avoid code duplication with DoDivI.
void LCodeGen::DoFlooringDivI(LFlooringDivI* instr) {
  HBinaryOperation* hdiv = instr->hydrogen();
  Register dividend = ToRegister(instr->dividend());
  Register divisor = ToRegister(instr->divisor());
  Register remainder = ToRegister(instr->temp());
  Register result = ToRegister(instr->result());
  DCHECK(dividend.is(rax));
  DCHECK(remainder.is(rdx));
  DCHECK(result.is(rax));
  DCHECK(!divisor.is(rax));
  DCHECK(!divisor.is(rdx));
 
  // Check for x / 0.
  if (hdiv->CheckFlag(HValue::kCanBeDivByZero)) {
    __ testl(divisor, divisor);
    DeoptimizeIf(zero, instr, "division by zero");
  }
 
  // Check for (0 / -x) that will produce negative zero.
  if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero)) {
    Label dividend_not_zero;
    __ testl(dividend, dividend);
    __ j(not_zero, &dividend_not_zero, Label::kNear);
    __ testl(divisor, divisor);
    DeoptimizeIf(sign, instr, "minus zero");
    __ bind(&dividend_not_zero);
  }
 
  // Check for (kMinInt / -1).
  if (hdiv->CheckFlag(HValue::kCanOverflow)) {
    Label dividend_not_min_int;
    __ cmpl(dividend, Immediate(kMinInt));
    __ j(not_zero, &dividend_not_min_int, Label::kNear);
    __ cmpl(divisor, Immediate(-1));
    DeoptimizeIf(zero, instr, "overflow");
    __ bind(&dividend_not_min_int);
  }
 
  // Sign extend to rdx (= remainder).
  __ cdq();
  __ idivl(divisor);
 
  Label done;
  __ testl(remainder, remainder);
  __ j(zero, &done, Label::kNear);
  __ xorl(remainder, divisor);
  __ sarl(remainder, Immediate(31));
  __ addl(result, remainder);
  __ bind(&done);
}
 
 
void LCodeGen::DoDivByPowerOf2I(LDivByPowerOf2I* instr) {
  Register dividend = ToRegister(instr->dividend());
  int32_t divisor = instr->divisor();
  Register result = ToRegister(instr->result());
  DCHECK(divisor == kMinInt || base::bits::IsPowerOfTwo32(Abs(divisor)));
  DCHECK(!result.is(dividend));
 
  // Check for (0 / -x) that will produce negative zero.
  HDiv* hdiv = instr->hydrogen();
  if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
    __ testl(dividend, dividend);
    DeoptimizeIf(zero, instr, "minus zero");
  }
  // Check for (kMinInt / -1).
  if (hdiv->CheckFlag(HValue::kCanOverflow) && divisor == -1) {
    __ cmpl(dividend, Immediate(kMinInt));
    DeoptimizeIf(zero, instr, "overflow");
  }
  // Deoptimize if remainder will not be 0.
  if (!hdiv->CheckFlag(HInstruction::kAllUsesTruncatingToInt32) &&
      divisor != 1 && divisor != -1) {
    int32_t mask = divisor < 0 ? -(divisor + 1) : (divisor - 1);
    __ testl(dividend, Immediate(mask));
    DeoptimizeIf(not_zero, instr, "lost precision");
  }
  __ Move(result, dividend);
  int32_t shift = WhichPowerOf2Abs(divisor);
  if (shift > 0) {
    // The arithmetic shift is always OK, the 'if' is an optimization only.
    if (shift > 1) __ sarl(result, Immediate(31));
    __ shrl(result, Immediate(32 - shift));
    __ addl(result, dividend);
    __ sarl(result, Immediate(shift));
  }
  if (divisor < 0) __ negl(result);
}
 
 
void LCodeGen::DoDivByConstI(LDivByConstI* instr) {
  Register dividend = ToRegister(instr->dividend());
  int32_t divisor = instr->divisor();
  DCHECK(ToRegister(instr->result()).is(rdx));
 
  if (divisor == 0) {
    DeoptimizeIf(no_condition, instr, "division by zero");
    return;
  }
 
  // Check for (0 / -x) that will produce negative zero.
  HDiv* hdiv = instr->hydrogen();
  if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
    __ testl(dividend, dividend);
    DeoptimizeIf(zero, instr, "minus zero");
  }
 
  __ TruncatingDiv(dividend, Abs(divisor));
  if (divisor < 0) __ negl(rdx);
 
  if (!hdiv->CheckFlag(HInstruction::kAllUsesTruncatingToInt32)) {
    __ movl(rax, rdx);
    __ imull(rax, rax, Immediate(divisor));
    __ subl(rax, dividend);
    DeoptimizeIf(not_equal, instr, "lost precision");
  }
}
 
 
// TODO(svenpanne) Refactor this to avoid code duplication with DoFlooringDivI.
void LCodeGen::DoDivI(LDivI* instr) {
  HBinaryOperation* hdiv = instr->hydrogen();
  Register dividend = ToRegister(instr->dividend());
  Register divisor = ToRegister(instr->divisor());
  Register remainder = ToRegister(instr->temp());
  DCHECK(dividend.is(rax));
  DCHECK(remainder.is(rdx));
  DCHECK(ToRegister(instr->result()).is(rax));
  DCHECK(!divisor.is(rax));
  DCHECK(!divisor.is(rdx));
 
  // Check for x / 0.
  if (hdiv->CheckFlag(HValue::kCanBeDivByZero)) {
    __ testl(divisor, divisor);
    DeoptimizeIf(zero, instr, "division by zero");
  }
 
  // Check for (0 / -x) that will produce negative zero.
  if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero)) {
    Label dividend_not_zero;
    __ testl(dividend, dividend);
    __ j(not_zero, &dividend_not_zero, Label::kNear);
    __ testl(divisor, divisor);
    DeoptimizeIf(sign, instr, "minus zero");
    __ bind(&dividend_not_zero);
  }
 
  // Check for (kMinInt / -1).
  if (hdiv->CheckFlag(HValue::kCanOverflow)) {
    Label dividend_not_min_int;
    __ cmpl(dividend, Immediate(kMinInt));
    __ j(not_zero, &dividend_not_min_int, Label::kNear);
    __ cmpl(divisor, Immediate(-1));
    DeoptimizeIf(zero, instr, "overflow");
    __ bind(&dividend_not_min_int);
  }
 
  // Sign extend to rdx (= remainder).
  __ cdq();
  __ idivl(divisor);
 
  if (!hdiv->CheckFlag(HValue::kAllUsesTruncatingToInt32)) {
    // Deoptimize if remainder is not 0.
    __ testl(remainder, remainder);
    DeoptimizeIf(not_zero, instr, "lost precision");
  }
}
 
 
void LCodeGen::DoMulI(LMulI* instr) {
  Register left = ToRegister(instr->left());
  LOperand* right = instr->right();
 
  if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
    if (instr->hydrogen_value()->representation().IsSmi()) {
      __ movp(kScratchRegister, left);
    } else {
      __ movl(kScratchRegister, left);
    }
  }
 
  bool can_overflow =
      instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
  if (right->IsConstantOperand()) {
    int32_t right_value = ToInteger32(LConstantOperand::cast(right));
    if (right_value == -1) {
      __ negl(left);
    } else if (right_value == 0) {
      __ xorl(left, left);
    } else if (right_value == 2) {
      __ addl(left, left);
    } else if (!can_overflow) {
      // If the multiplication is known to not overflow, we
      // can use operations that don't set the overflow flag
      // correctly.
      switch (right_value) {
        case 1:
          // Do nothing.
          break;
        case 3:
          __ leal(left, Operand(left, left, times_2, 0));
          break;
        case 4:
          __ shll(left, Immediate(2));
          break;
        case 5:
          __ leal(left, Operand(left, left, times_4, 0));
          break;
        case 8:
          __ shll(left, Immediate(3));
          break;
        case 9:
          __ leal(left, Operand(left, left, times_8, 0));
          break;
        case 16:
          __ shll(left, Immediate(4));
          break;
        default:
          __ imull(left, left, Immediate(right_value));
          break;
      }
    } else {
      __ imull(left, left, Immediate(right_value));
    }
  } else if (right->IsStackSlot()) {
    if (instr->hydrogen_value()->representation().IsSmi()) {
      __ SmiToInteger64(left, left);
      __ imulp(left, ToOperand(right));
    } else {
      __ imull(left, ToOperand(right));
    }
  } else {
    if (instr->hydrogen_value()->representation().IsSmi()) {
      __ SmiToInteger64(left, left);
      __ imulp(left, ToRegister(right));
    } else {
      __ imull(left, ToRegister(right));
    }
  }
 
  if (can_overflow) {
    DeoptimizeIf(overflow, instr, "overflow");
  }
 
  if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
    // Bail out if the result is supposed to be negative zero.
    Label done;
    if (instr->hydrogen_value()->representation().IsSmi()) {
      __ testp(left, left);
    } else {
      __ testl(left, left);
    }
    __ j(not_zero, &done, Label::kNear);
    if (right->IsConstantOperand()) {
      // Constant can't be represented as 32-bit Smi due to immediate size
      // limit.
      DCHECK(SmiValuesAre32Bits()
          ? !instr->hydrogen_value()->representation().IsSmi()
          : SmiValuesAre31Bits());
      if (ToInteger32(LConstantOperand::cast(right)) < 0) {
        DeoptimizeIf(no_condition, instr, "minus zero");
      } else if (ToInteger32(LConstantOperand::cast(right)) == 0) {
        __ cmpl(kScratchRegister, Immediate(0));
        DeoptimizeIf(less, instr, "minus zero");
      }
    } else if (right->IsStackSlot()) {
      if (instr->hydrogen_value()->representation().IsSmi()) {
        __ orp(kScratchRegister, ToOperand(right));
      } else {
        __ orl(kScratchRegister, ToOperand(right));
      }
      DeoptimizeIf(sign, instr, "minus zero");
    } else {
      // Test the non-zero operand for negative sign.
      if (instr->hydrogen_value()->representation().IsSmi()) {
        __ orp(kScratchRegister, ToRegister(right));
      } else {
        __ orl(kScratchRegister, ToRegister(right));
      }
      DeoptimizeIf(sign, instr, "minus zero");
    }
    __ bind(&done);
  }
}
 
 
void LCodeGen::DoBitI(LBitI* instr) {
  LOperand* left = instr->left();
  LOperand* right = instr->right();
  DCHECK(left->Equals(instr->result()));
  DCHECK(left->IsRegister());
 
  if (right->IsConstantOperand()) {
    int32_t right_operand =
        ToRepresentation(LConstantOperand::cast(right),
                         instr->hydrogen()->right()->representation());
    switch (instr->op()) {
      case Token::BIT_AND:
        __ andl(ToRegister(left), Immediate(right_operand));
        break;
      case Token::BIT_OR:
        __ orl(ToRegister(left), Immediate(right_operand));
        break;
      case Token::BIT_XOR:
        if (right_operand == int32_t(~0)) {
          __ notl(ToRegister(left));
        } else {
          __ xorl(ToRegister(left), Immediate(right_operand));
        }
        break;
      default:
        UNREACHABLE();
        break;
    }
  } else if (right->IsStackSlot()) {
    switch (instr->op()) {
      case Token::BIT_AND:
        if (instr->IsInteger32()) {
          __ andl(ToRegister(left), ToOperand(right));
        } else {
          __ andp(ToRegister(left), ToOperand(right));
        }
        break;
      case Token::BIT_OR:
        if (instr->IsInteger32()) {
          __ orl(ToRegister(left), ToOperand(right));
        } else {
          __ orp(ToRegister(left), ToOperand(right));
        }
        break;
      case Token::BIT_XOR:
        if (instr->IsInteger32()) {
          __ xorl(ToRegister(left), ToOperand(right));
        } else {
          __ xorp(ToRegister(left), ToOperand(right));
        }
        break;
      default:
        UNREACHABLE();
        break;
    }
  } else {
    DCHECK(right->IsRegister());
    switch (instr->op()) {
      case Token::BIT_AND:
        if (instr->IsInteger32()) {
          __ andl(ToRegister(left), ToRegister(right));
        } else {
          __ andp(ToRegister(left), ToRegister(right));
        }
        break;
      case Token::BIT_OR:
        if (instr->IsInteger32()) {
          __ orl(ToRegister(left), ToRegister(right));
        } else {
          __ orp(ToRegister(left), ToRegister(right));
        }
        break;
      case Token::BIT_XOR:
        if (instr->IsInteger32()) {
          __ xorl(ToRegister(left), ToRegister(right));
        } else {
          __ xorp(ToRegister(left), ToRegister(right));
        }
        break;
      default:
        UNREACHABLE();
        break;
    }
  }
}
 
 
void LCodeGen::DoShiftI(LShiftI* instr) {
  LOperand* left = instr->left();
  LOperand* right = instr->right();
  DCHECK(left->Equals(instr->result()));
  DCHECK(left->IsRegister());
  if (right->IsRegister()) {
    DCHECK(ToRegister(right).is(rcx));
 
    switch (instr->op()) {
      case Token::ROR:
        __ rorl_cl(ToRegister(left));
        break;
      case Token::SAR:
        __ sarl_cl(ToRegister(left));
        break;
      case Token::SHR:
        __ shrl_cl(ToRegister(left));
        if (instr->can_deopt()) {
          __ testl(ToRegister(left), ToRegister(left));
          DeoptimizeIf(negative, instr, "negative value");
        }
        break;
      case Token::SHL:
        __ shll_cl(ToRegister(left));
        break;
      default:
        UNREACHABLE();
        break;
    }
  } else {
    int32_t 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) {
          __ rorl(ToRegister(left), Immediate(shift_count));
        }
        break;
      case Token::SAR:
        if (shift_count != 0) {
          __ sarl(ToRegister(left), Immediate(shift_count));
        }
        break;
      case Token::SHR:
        if (shift_count != 0) {
          __ shrl(ToRegister(left), Immediate(shift_count));
        } else if (instr->can_deopt()) {
          __ testl(ToRegister(left), ToRegister(left));
          DeoptimizeIf(negative, instr, "negative value");
        }
        break;
      case Token::SHL:
        if (shift_count != 0) {
          if (instr->hydrogen_value()->representation().IsSmi()) {
            if (SmiValuesAre32Bits()) {
              __ shlp(ToRegister(left), Immediate(shift_count));
            } else {
              DCHECK(SmiValuesAre31Bits());
              if (instr->can_deopt()) {
                if (shift_count != 1) {
                  __ shll(ToRegister(left), Immediate(shift_count - 1));
                }
                __ Integer32ToSmi(ToRegister(left), ToRegister(left));
                DeoptimizeIf(overflow, instr, "overflow");
              } else {
                __ shll(ToRegister(left), Immediate(shift_count));
              }
            }
          } else {
            __ shll(ToRegister(left), Immediate(shift_count));
          }
        }
        break;
      default:
        UNREACHABLE();
        break;
    }
  }
}
 
 
void LCodeGen::DoSubI(LSubI* instr) {
  LOperand* left = instr->left();
  LOperand* right = instr->right();
  DCHECK(left->Equals(instr->result()));
 
  if (right->IsConstantOperand()) {
    int32_t right_operand =
        ToRepresentation(LConstantOperand::cast(right),
                         instr->hydrogen()->right()->representation());
    __ subl(ToRegister(left), Immediate(right_operand));
  } else if (right->IsRegister()) {
    if (instr->hydrogen_value()->representation().IsSmi()) {
      __ subp(ToRegister(left), ToRegister(right));
    } else {
      __ subl(ToRegister(left), ToRegister(right));
    }
  } else {
    if (instr->hydrogen_value()->representation().IsSmi()) {
      __ subp(ToRegister(left), ToOperand(right));
    } else {
      __ subl(ToRegister(left), ToOperand(right));
    }
  }
 
  if (instr->hydrogen()->CheckFlag(HValue::kCanOverflow)) {
    DeoptimizeIf(overflow, instr, "overflow");
  }
}
 
 
void LCodeGen::DoConstantI(LConstantI* instr) {
  Register dst = ToRegister(instr->result());
  if (instr->value() == 0) {
    __ xorl(dst, dst);
  } else {
    __ movl(dst, Immediate(instr->value()));
  }
}
 
 
void LCodeGen::DoConstantS(LConstantS* instr) {
  __ Move(ToRegister(instr->result()), instr->value());
}
 
 
void LCodeGen::DoConstantD(LConstantD* instr) {
  DCHECK(instr->result()->IsDoubleRegister());
  XMMRegister res = ToDoubleRegister(instr->result());
  double v = instr->value();
  uint64_t int_val = bit_cast<uint64_t, double>(v);
  // Use xor to produce +0.0 in a fast and compact way, but avoid to
  // do so if the constant is -0.0.
  if (int_val == 0) {
    __ xorps(res, res);
  } else {
    Register tmp = ToRegister(instr->temp());
    __ Set(tmp, int_val);
    __ movq(res, tmp);
  }
}
 
 
void LCodeGen::DoConstantE(LConstantE* instr) {
  __ LoadAddress(ToRegister(instr->result()), instr->value());
}
 
 
void LCodeGen::DoConstantT(LConstantT* instr) {
  Handle<Object> object = instr->value(isolate());
  AllowDeferredHandleDereference smi_check;
  __ Move(ToRegister(instr->result()), object);
}
 
 
void LCodeGen::DoMapEnumLength(LMapEnumLength* instr) {
  Register result = ToRegister(instr->result());
  Register map = ToRegister(instr->value());
  __ EnumLength(result, map);
}
 
 
void LCodeGen::DoDateField(LDateField* instr) {
  Register object = ToRegister(instr->date());
  Register result = ToRegister(instr->result());
  Smi* index = instr->index();
  Label runtime, done, not_date_object;
  DCHECK(object.is(result));
  DCHECK(object.is(rax));
 
  Condition cc = masm()->CheckSmi(object);
  DeoptimizeIf(cc, instr, "Smi");
  __ CmpObjectType(object, JS_DATE_TYPE, kScratchRegister);
  DeoptimizeIf(not_equal, instr, "not a date object");
 
  if (index->value() == 0) {
    __ movp(result, FieldOperand(object, JSDate::kValueOffset));
  } else {
    if (index->value() < JSDate::kFirstUncachedField) {
      ExternalReference stamp = ExternalReference::date_cache_stamp(isolate());
      Operand stamp_operand = __ ExternalOperand(stamp);
      __ movp(kScratchRegister, stamp_operand);
      __ cmpp(kScratchRegister, FieldOperand(object,
                                             JSDate::kCacheStampOffset));
      __ j(not_equal, &runtime, Label::kNear);
      __ movp(result, FieldOperand(object, JSDate::kValueOffset +
                                           kPointerSize * index->value()));
      __ jmp(&done, Label::kNear);
    }
    __ bind(&runtime);
    __ PrepareCallCFunction(2);
    __ movp(arg_reg_1, object);
    __ Move(arg_reg_2, index, Assembler::RelocInfoNone());
    __ CallCFunction(ExternalReference::get_date_field_function(isolate()), 2);
    __ bind(&done);
  }
}
 
 
Operand LCodeGen::BuildSeqStringOperand(Register string,
                                        LOperand* index,
                                        String::Encoding encoding) {
  if (index->IsConstantOperand()) {
    int offset = ToInteger32(LConstantOperand::cast(index));
    if (encoding == String::TWO_BYTE_ENCODING) {
      offset *= kUC16Size;
    }
    STATIC_ASSERT(kCharSize == 1);
    return FieldOperand(string, SeqString::kHeaderSize + offset);
  }
  return FieldOperand(
      string, ToRegister(index),
      encoding == String::ONE_BYTE_ENCODING ? times_1 : times_2,
      SeqString::kHeaderSize);
}
 
 
void LCodeGen::DoSeqStringGetChar(LSeqStringGetChar* instr) {
  String::Encoding encoding = instr->hydrogen()->encoding();
  Register result = ToRegister(instr->result());
  Register string = ToRegister(instr->string());
 
  if (FLAG_debug_code) {
    __ Push(string);
    __ movp(string, FieldOperand(string, HeapObject::kMapOffset));
    __ movzxbp(string, FieldOperand(string, Map::kInstanceTypeOffset));
 
    __ andb(string, Immediate(kStringRepresentationMask | kStringEncodingMask));
    static const uint32_t one_byte_seq_type = kSeqStringTag | kOneByteStringTag;
    static const uint32_t two_byte_seq_type = kSeqStringTag | kTwoByteStringTag;
    __ cmpp(string, Immediate(encoding == String::ONE_BYTE_ENCODING
                              ? one_byte_seq_type : two_byte_seq_type));
    __ Check(equal, kUnexpectedStringType);
    __ Pop(string);
  }
 
  Operand operand = BuildSeqStringOperand(string, instr->index(), encoding);
  if (encoding == String::ONE_BYTE_ENCODING) {
    __ movzxbl(result, operand);
  } else {
    __ movzxwl(result, operand);
  }
}
 
 
void LCodeGen::DoSeqStringSetChar(LSeqStringSetChar* instr) {
  String::Encoding encoding = instr->hydrogen()->encoding();
  Register string = ToRegister(instr->string());
 
  if (FLAG_debug_code) {
    Register value = ToRegister(instr->value());
    Register index = ToRegister(instr->index());
    static const uint32_t one_byte_seq_type = kSeqStringTag | kOneByteStringTag;
    static const uint32_t two_byte_seq_type = kSeqStringTag | kTwoByteStringTag;
    int encoding_mask =
        instr->hydrogen()->encoding() == String::ONE_BYTE_ENCODING
        ? one_byte_seq_type : two_byte_seq_type;
    __ EmitSeqStringSetCharCheck(string, index, value, encoding_mask);
  }
 
  Operand operand = BuildSeqStringOperand(string, instr->index(), encoding);
  if (instr->value()->IsConstantOperand()) {
    int value = ToInteger32(LConstantOperand::cast(instr->value()));
    DCHECK_LE(0, value);
    if (encoding == String::ONE_BYTE_ENCODING) {
      DCHECK_LE(value, String::kMaxOneByteCharCode);
      __ movb(operand, Immediate(value));
    } else {
      DCHECK_LE(value, String::kMaxUtf16CodeUnit);
      __ movw(operand, Immediate(value));
    }
  } else {
    Register value = ToRegister(instr->value());
    if (encoding == String::ONE_BYTE_ENCODING) {
      __ movb(operand, value);
    } else {
      __ movw(operand, value);
    }
  }
}
 
 
void LCodeGen::DoAddI(LAddI* instr) {
  LOperand* left = instr->left();
  LOperand* right = instr->right();
 
  Representation target_rep = instr->hydrogen()->representation();
  bool is_p = target_rep.IsSmi() || target_rep.IsExternal();
 
  if (LAddI::UseLea(instr->hydrogen()) && !left->Equals(instr->result())) {
    if (right->IsConstantOperand()) {
      // No support for smi-immediates for 32-bit SMI.
      DCHECK(SmiValuesAre32Bits() ? !target_rep.IsSmi() : SmiValuesAre31Bits());
      int32_t offset =
          ToRepresentation(LConstantOperand::cast(right),
                           instr->hydrogen()->right()->representation());
      if (is_p) {
        __ leap(ToRegister(instr->result()),
                MemOperand(ToRegister(left), offset));
      } else {
        __ leal(ToRegister(instr->result()),
                MemOperand(ToRegister(left), offset));
      }
    } else {
      Operand address(ToRegister(left), ToRegister(right), times_1, 0);
      if (is_p) {
        __ leap(ToRegister(instr->result()), address);
      } else {
        __ leal(ToRegister(instr->result()), address);
      }
    }
  } else {
    if (right->IsConstantOperand()) {
      // No support for smi-immediates for 32-bit SMI.
      DCHECK(SmiValuesAre32Bits() ? !target_rep.IsSmi() : SmiValuesAre31Bits());
      int32_t right_operand =
          ToRepresentation(LConstantOperand::cast(right),
                           instr->hydrogen()->right()->representation());
      if (is_p) {
        __ addp(ToRegister(left), Immediate(right_operand));
      } else {
        __ addl(ToRegister(left), Immediate(right_operand));
      }
    } else if (right->IsRegister()) {
      if (is_p) {
        __ addp(ToRegister(left), ToRegister(right));
      } else {
        __ addl(ToRegister(left), ToRegister(right));
      }
    } else {
      if (is_p) {
        __ addp(ToRegister(left), ToOperand(right));
      } else {
        __ addl(ToRegister(left), ToOperand(right));
      }
    }
    if (instr->hydrogen()->CheckFlag(HValue::kCanOverflow)) {
      DeoptimizeIf(overflow, instr, "overflow");
    }
  }
}
 
 
void LCodeGen::DoMathMinMax(LMathMinMax* instr) {
  LOperand* left = instr->left();
  LOperand* right = instr->right();
  DCHECK(left->Equals(instr->result()));
  HMathMinMax::Operation operation = instr->hydrogen()->operation();
  if (instr->hydrogen()->representation().IsSmiOrInteger32()) {
    Label return_left;
    Condition condition = (operation == HMathMinMax::kMathMin)
        ? less_equal
        : greater_equal;
    Register left_reg = ToRegister(left);
    if (right->IsConstantOperand()) {
      Immediate right_imm = Immediate(
          ToRepresentation(LConstantOperand::cast(right),
                           instr->hydrogen()->right()->representation()));
      DCHECK(SmiValuesAre32Bits()
          ? !instr->hydrogen()->representation().IsSmi()
          : SmiValuesAre31Bits());
      __ cmpl(left_reg, right_imm);
      __ j(condition, &return_left, Label::kNear);
      __ movp(left_reg, right_imm);
    } else if (right->IsRegister()) {
      Register right_reg = ToRegister(right);
      if (instr->hydrogen_value()->representation().IsSmi()) {
        __ cmpp(left_reg, right_reg);
      } else {
        __ cmpl(left_reg, right_reg);
      }
      __ j(condition, &return_left, Label::kNear);
      __ movp(left_reg, right_reg);
    } else {
      Operand right_op = ToOperand(right);
      if (instr->hydrogen_value()->representation().IsSmi()) {
        __ cmpp(left_reg, right_op);
      } else {
        __ cmpl(left_reg, right_op);
      }
      __ j(condition, &return_left, Label::kNear);
      __ movp(left_reg, right_op);
    }
    __ bind(&return_left);
  } else {
    DCHECK(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 = double_scratch0();
    __ 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) {
      __ orps(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);
    __ bind(&return_right);
    __ movaps(left_reg, right_reg);
 
    __ bind(&return_left);
  }
}
 
 
void LCodeGen::DoArithmeticD(LArithmeticD* instr) {
  XMMRegister left = ToDoubleRegister(instr->left());
  XMMRegister right = ToDoubleRegister(instr->right());
  XMMRegister result = ToDoubleRegister(instr->result());
  // All operations except MOD are computed in-place.
  DCHECK(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: {
      XMMRegister xmm_scratch = double_scratch0();
      __ PrepareCallCFunction(2);
      __ movaps(xmm_scratch, left);
      DCHECK(right.is(xmm1));
      __ CallCFunction(
          ExternalReference::mod_two_doubles_operation(isolate()), 2);
      __ movaps(result, xmm_scratch);
      break;
    }
    default:
      UNREACHABLE();
      break;
  }
}
 
 
void LCodeGen::DoArithmeticT(LArithmeticT* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  DCHECK(ToRegister(instr->left()).is(rdx));
  DCHECK(ToRegister(instr->right()).is(rax));
  DCHECK(ToRegister(instr->result()).is(rax));
 
  Handle<Code> code =
      CodeFactory::BinaryOpIC(isolate(), instr->op(), NO_OVERWRITE).code();
  CallCode(code, RelocInfo::CODE_TARGET, instr);
}
 
 
template<class InstrType>
void LCodeGen::EmitBranch(InstrType instr, Condition cc) {
  int left_block = instr->TrueDestination(chunk_);
  int right_block = instr->FalseDestination(chunk_);
 
  int next_block = GetNextEmittedBlock();
 
  if (right_block == left_block || cc == no_condition) {
    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));
    if (cc != always) {
      __ jmp(chunk_->GetAssemblyLabel(right_block));
    }
  }
}
 
 
template<class InstrType>
void LCodeGen::EmitFalseBranch(InstrType instr, Condition cc) {
  int false_block = instr->FalseDestination(chunk_);
  __ j(cc, chunk_->GetAssemblyLabel(false_block));
}
 
 
void LCodeGen::DoDebugBreak(LDebugBreak* instr) {
  __ int3();
}
 
 
void LCodeGen::DoBranch(LBranch* instr) {
  Representation r = instr->hydrogen()->value()->representation();
  if (r.IsInteger32()) {
    DCHECK(!info()->IsStub());
    Register reg = ToRegister(instr->value());
    __ testl(reg, reg);
    EmitBranch(instr, not_zero);
  } else if (r.IsSmi()) {
    DCHECK(!info()->IsStub());
    Register reg = ToRegister(instr->value());
    __ testp(reg, reg);
    EmitBranch(instr, not_zero);
  } else if (r.IsDouble()) {
    DCHECK(!info()->IsStub());
    XMMRegister reg = ToDoubleRegister(instr->value());
    XMMRegister xmm_scratch = double_scratch0();
    __ xorps(xmm_scratch, xmm_scratch);
    __ ucomisd(reg, xmm_scratch);
    EmitBranch(instr, not_equal);
  } else {
    DCHECK(r.IsTagged());
    Register reg = ToRegister(instr->value());
    HType type = instr->hydrogen()->value()->type();
    if (type.IsBoolean()) {
      DCHECK(!info()->IsStub());
      __ CompareRoot(reg, Heap::kTrueValueRootIndex);
      EmitBranch(instr, equal);
    } else if (type.IsSmi()) {
      DCHECK(!info()->IsStub());
      __ SmiCompare(reg, Smi::FromInt(0));
      EmitBranch(instr, not_equal);
    } else if (type.IsJSArray()) {
      DCHECK(!info()->IsStub());
      EmitBranch(instr, no_condition);
    } else if (type.IsHeapNumber()) {
      DCHECK(!info()->IsStub());
      XMMRegister xmm_scratch = double_scratch0();
      __ xorps(xmm_scratch, xmm_scratch);
      __ ucomisd(xmm_scratch, FieldOperand(reg, HeapNumber::kValueOffset));
      EmitBranch(instr, not_equal);
    } else if (type.IsString()) {
      DCHECK(!info()->IsStub());
      __ cmpp(FieldOperand(reg, String::kLengthOffset), Immediate(0));
      EmitBranch(instr, not_equal);
    } else {
      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::Types::Generic();
 
      if (expected.Contains(ToBooleanStub::UNDEFINED)) {
        // undefined -> false.
        __ CompareRoot(reg, Heap::kUndefinedValueRootIndex);
        __ j(equal, instr->FalseLabel(chunk_));
      }
      if (expected.Contains(ToBooleanStub::BOOLEAN)) {
        // true -> true.
        __ CompareRoot(reg, Heap::kTrueValueRootIndex);
        __ j(equal, instr->TrueLabel(chunk_));
        // false -> false.
        __ CompareRoot(reg, Heap::kFalseValueRootIndex);
        __ j(equal, instr->FalseLabel(chunk_));
      }
      if (expected.Contains(ToBooleanStub::NULL_TYPE)) {
        // 'null' -> false.
        __ CompareRoot(reg, Heap::kNullValueRootIndex);
        __ j(equal, instr->FalseLabel(chunk_));
      }
 
      if (expected.Contains(ToBooleanStub::SMI)) {
        // Smis: 0 -> false, all other -> true.
        __ Cmp(reg, Smi::FromInt(0));
        __ j(equal, instr->FalseLabel(chunk_));
        __ JumpIfSmi(reg, instr->TrueLabel(chunk_));
      } else if (expected.NeedsMap()) {
        // If we need a map later and have a Smi -> deopt.
        __ testb(reg, Immediate(kSmiTagMask));
        DeoptimizeIf(zero, instr, "Smi");
      }
 
      const Register map = kScratchRegister;
      if (expected.NeedsMap()) {
        __ movp(map, FieldOperand(reg, HeapObject::kMapOffset));
 
        if (expected.CanBeUndetectable()) {
          // Undetectable -> false.
          __ testb(FieldOperand(map, Map::kBitFieldOffset),
                   Immediate(1 << Map::kIsUndetectable));
          __ j(not_zero, instr->FalseLabel(chunk_));
        }
      }
 
      if (expected.Contains(ToBooleanStub::SPEC_OBJECT)) {
        // spec object -> true.
        __ CmpInstanceType(map, FIRST_SPEC_OBJECT_TYPE);
        __ j(above_equal, instr->TrueLabel(chunk_));
      }
 
      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);
        __ cmpp(FieldOperand(reg, String::kLengthOffset), Immediate(0));
        __ j(not_zero, instr->TrueLabel(chunk_));
        __ jmp(instr->FalseLabel(chunk_));
        __ bind(&not_string);
      }
 
      if (expected.Contains(ToBooleanStub::SYMBOL)) {
        // Symbol value -> true.
        __ CmpInstanceType(map, SYMBOL_TYPE);
        __ j(equal, instr->TrueLabel(chunk_));
      }
 
      if (expected.Contains(ToBooleanStub::HEAP_NUMBER)) {
        // heap number -> false iff +0, -0, or NaN.
        Label not_heap_number;
        __ CompareRoot(map, Heap::kHeapNumberMapRootIndex);
        __ j(not_equal, &not_heap_number, Label::kNear);
        XMMRegister xmm_scratch = double_scratch0();
        __ xorps(xmm_scratch, xmm_scratch);
        __ ucomisd(xmm_scratch, FieldOperand(reg, HeapNumber::kValueOffset));
        __ j(zero, instr->FalseLabel(chunk_));
        __ jmp(instr->TrueLabel(chunk_));
        __ bind(&not_heap_number);
      }
 
      if (!expected.IsGeneric()) {
        // We've seen something for the first time -> deopt.
        // This can only happen if we are not generic already.
        DeoptimizeIf(no_condition, instr, "unexpected object");
      }
    }
  }
}
 
 
void LCodeGen::EmitGoto(int block) {
  if (!IsNextEmittedBlock(block)) {
    __ jmp(chunk_->GetAssemblyLabel(chunk_->LookupDestination(block)));
  }
}
 
 
void LCodeGen::DoGoto(LGoto* instr) {
  EmitGoto(instr->block_id());
}
 
 
inline 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::NE:
    case Token::NE_STRICT:
      cond = not_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::DoCompareNumericAndBranch(LCompareNumericAndBranch* instr) {
  LOperand* left = instr->left();
  LOperand* right = instr->right();
  bool is_unsigned =
      instr->is_double() ||
      instr->hydrogen()->left()->CheckFlag(HInstruction::kUint32) ||
      instr->hydrogen()->right()->CheckFlag(HInstruction::kUint32);
  Condition cc = TokenToCondition(instr->op(), is_unsigned);
 
  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) ?
        instr->TrueDestination(chunk_) : instr->FalseDestination(chunk_);
    EmitGoto(next_block);
  } else {
    if (instr->is_double()) {
      // 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, instr->FalseLabel(chunk_));
    } else {
      int32_t value;
      if (right->IsConstantOperand()) {
        value = ToInteger32(LConstantOperand::cast(right));
        if (instr->hydrogen_value()->representation().IsSmi()) {
          __ Cmp(ToRegister(left), Smi::FromInt(value));
        } else {
          __ cmpl(ToRegister(left), Immediate(value));
        }
      } else if (left->IsConstantOperand()) {
        value = ToInteger32(LConstantOperand::cast(left));
        if (instr->hydrogen_value()->representation().IsSmi()) {
          if (right->IsRegister()) {
            __ Cmp(ToRegister(right), Smi::FromInt(value));
          } else {
            __ Cmp(ToOperand(right), Smi::FromInt(value));
          }
        } else if (right->IsRegister()) {
          __ cmpl(ToRegister(right), Immediate(value));
        } else {
          __ cmpl(ToOperand(right), Immediate(value));
        }
        // We commuted the operands, so commute the condition.
        cc = CommuteCondition(cc);
      } else if (instr->hydrogen_value()->representation().IsSmi()) {
        if (right->IsRegister()) {
          __ cmpp(ToRegister(left), ToRegister(right));
        } else {
          __ cmpp(ToRegister(left), ToOperand(right));
        }
      } else {
        if (right->IsRegister()) {
          __ cmpl(ToRegister(left), ToRegister(right));
        } else {
          __ cmpl(ToRegister(left), ToOperand(right));
        }
      }
    }
    EmitBranch(instr, cc);
  }
}
 
 
void LCodeGen::DoCmpObjectEqAndBranch(LCmpObjectEqAndBranch* instr) {
  Register left = ToRegister(instr->left());
 
  if (instr->right()->IsConstantOperand()) {
    Handle<Object> right = ToHandle(LConstantOperand::cast(instr->right()));
    __ Cmp(left, right);
  } else {
    Register right = ToRegister(instr->right());
    __ cmpp(left, right);
  }
  EmitBranch(instr, equal);
}
 
 
void LCodeGen::DoCmpHoleAndBranch(LCmpHoleAndBranch* instr) {
  if (instr->hydrogen()->representation().IsTagged()) {
    Register input_reg = ToRegister(instr->object());
    __ Cmp(input_reg, factory()->the_hole_value());
    EmitBranch(instr, equal);
    return;
  }
 
  XMMRegister input_reg = ToDoubleRegister(instr->object());
  __ ucomisd(input_reg, input_reg);
  EmitFalseBranch(instr, parity_odd);
 
  __ subp(rsp, Immediate(kDoubleSize));
  __ movsd(MemOperand(rsp, 0), input_reg);
  __ addp(rsp, Immediate(kDoubleSize));
 
  int offset = sizeof(kHoleNanUpper32);
  __ cmpl(MemOperand(rsp, -offset), Immediate(kHoleNanUpper32));
  EmitBranch(instr, equal);
}
 
 
void LCodeGen::DoCompareMinusZeroAndBranch(LCompareMinusZeroAndBranch* instr) {
  Representation rep = instr->hydrogen()->value()->representation();
  DCHECK(!rep.IsInteger32());
 
  if (rep.IsDouble()) {
    XMMRegister value = ToDoubleRegister(instr->value());
    XMMRegister xmm_scratch = double_scratch0();
    __ xorps(xmm_scratch, xmm_scratch);
    __ ucomisd(xmm_scratch, value);
    EmitFalseBranch(instr, not_equal);
    __ movmskpd(kScratchRegister, value);
    __ testl(kScratchRegister, Immediate(1));
    EmitBranch(instr, not_zero);
  } else {
    Register value = ToRegister(instr->value());
    Handle<Map> map = masm()->isolate()->factory()->heap_number_map();
    __ CheckMap(value, map, instr->FalseLabel(chunk()), DO_SMI_CHECK);
    __ cmpl(FieldOperand(value, HeapNumber::kExponentOffset),
            Immediate(0x1));
    EmitFalseBranch(instr, no_overflow);
    __ cmpl(FieldOperand(value, HeapNumber::kMantissaOffset),
            Immediate(0x00000000));
    EmitBranch(instr, equal);
  }
}
 
 
Condition LCodeGen::EmitIsObject(Register input,
                                 Label* is_not_object,
                                 Label* is_object) {
  DCHECK(!input.is(kScratchRegister));
 
  __ JumpIfSmi(input, is_not_object);
 
  __ CompareRoot(input, Heap::kNullValueRootIndex);
  __ j(equal, is_object);
 
  __ movp(kScratchRegister, FieldOperand(input, HeapObject::kMapOffset));
  // Undetectable objects behave like undefined.
  __ testb(FieldOperand(kScratchRegister, Map::kBitFieldOffset),
           Immediate(1 << Map::kIsUndetectable));
  __ j(not_zero, is_not_object);
 
  __ movzxbl(kScratchRegister,
             FieldOperand(kScratchRegister, Map::kInstanceTypeOffset));
  __ cmpb(kScratchRegister, Immediate(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
  __ j(below, is_not_object);
  __ cmpb(kScratchRegister, Immediate(LAST_NONCALLABLE_SPEC_OBJECT_TYPE));
  return below_equal;
}
 
 
void LCodeGen::DoIsObjectAndBranch(LIsObjectAndBranch* instr) {
  Register reg = ToRegister(instr->value());
 
  Condition true_cond = EmitIsObject(
      reg, instr->FalseLabel(chunk_), instr->TrueLabel(chunk_));
 
  EmitBranch(instr, true_cond);
}
 
 
Condition LCodeGen::EmitIsString(Register input,
                                 Register temp1,
                                 Label* is_not_string,
                                 SmiCheck check_needed = INLINE_SMI_CHECK) {
  if (check_needed == INLINE_SMI_CHECK) {
    __ 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());
 
  SmiCheck check_needed =
      instr->hydrogen()->value()->type().IsHeapObject()
          ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
 
  Condition true_cond = EmitIsString(
      reg, temp, instr->FalseLabel(chunk_), check_needed);
 
  EmitBranch(instr, true_cond);
}
 
 
void LCodeGen::DoIsSmiAndBranch(LIsSmiAndBranch* instr) {
  Condition is_smi;
  if (instr->value()->IsRegister()) {
    Register input = ToRegister(instr->value());
    is_smi = masm()->CheckSmi(input);
  } else {
    Operand input = ToOperand(instr->value());
    is_smi = masm()->CheckSmi(input);
  }
  EmitBranch(instr, is_smi);
}
 
 
void LCodeGen::DoIsUndetectableAndBranch(LIsUndetectableAndBranch* instr) {
  Register input = ToRegister(instr->value());
  Register temp = ToRegister(instr->temp());
 
  if (!instr->hydrogen()->value()->type().IsHeapObject()) {
    __ JumpIfSmi(input, instr->FalseLabel(chunk_));
  }
  __ movp(temp, FieldOperand(input, HeapObject::kMapOffset));
  __ testb(FieldOperand(temp, Map::kBitFieldOffset),
           Immediate(1 << Map::kIsUndetectable));
  EmitBranch(instr, not_zero);
}
 
 
void LCodeGen::DoStringCompareAndBranch(LStringCompareAndBranch* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  Token::Value op = instr->op();
 
  Handle<Code> ic = CodeFactory::CompareIC(isolate(), op).code();
  CallCode(ic, RelocInfo::CODE_TARGET, instr);
 
  Condition condition = TokenToCondition(op, false);
  __ testp(rax, rax);
 
  EmitBranch(instr, condition);
}
 
 
static InstanceType TestType(HHasInstanceTypeAndBranch* instr) {
  InstanceType from = instr->from();
  InstanceType to = instr->to();
  if (from == FIRST_TYPE) return to;
  DCHECK(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());
 
  if (!instr->hydrogen()->value()->type().IsHeapObject()) {
    __ JumpIfSmi(input, instr->FalseLabel(chunk_));
  }
 
  __ CmpObjectType(input, TestType(instr->hydrogen()), kScratchRegister);
  EmitBranch(instr, BranchCondition(instr->hydrogen()));
}
 
 
void LCodeGen::DoGetCachedArrayIndex(LGetCachedArrayIndex* instr) {
  Register input = ToRegister(instr->value());
  Register result = ToRegister(instr->result());
 
  __ AssertString(input);
 
  __ movl(result, FieldOperand(input, String::kHashFieldOffset));
  DCHECK(String::kHashShift >= kSmiTagSize);
  __ IndexFromHash(result, result);
}
 
 
void LCodeGen::DoHasCachedArrayIndexAndBranch(
    LHasCachedArrayIndexAndBranch* instr) {
  Register input = ToRegister(instr->value());
 
  __ testl(FieldOperand(input, String::kHashFieldOffset),
           Immediate(String::kContainsCachedArrayIndexMask));
  EmitBranch(instr, equal);
}
 
 
// Branches to a label or falls through with the answer in the z flag.
// Trashes the temp register.
void LCodeGen::EmitClassOfTest(Label* is_true,
                               Label* is_false,
                               Handle<String> class_name,
                               Register input,
                               Register temp,
                               Register temp2) {
  DCHECK(!input.is(temp));
  DCHECK(!input.is(temp2));
  DCHECK(!temp.is(temp2));
 
  __ JumpIfSmi(input, is_false);
 
  if (String::Equals(isolate()->factory()->Function_string(), class_name)) {
    // 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.
    __ movp(temp, FieldOperand(input, HeapObject::kMapOffset));
    __ movzxbl(temp2, FieldOperand(temp, Map::kInstanceTypeOffset));
    __ subp(temp2, Immediate(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
    __ cmpp(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.
  __ movp(temp, FieldOperand(temp, Map::kConstructorOffset));
 
  // Objects with a non-function constructor have class 'Object'.
  __ CmpObjectType(temp, JS_FUNCTION_TYPE, kScratchRegister);
  if (String::Equals(class_name, isolate()->factory()->Object_string())) {
    __ j(not_equal, is_true);
  } else {
    __ j(not_equal, is_false);
  }
 
  // temp now contains the constructor function. Grab the
  // instance class name from there.
  __ movp(temp, FieldOperand(temp, JSFunction::kSharedFunctionInfoOffset));
  __ movp(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.
  DCHECK(class_name->IsInternalizedString());
  __ 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();
 
  EmitClassOfTest(instr->TrueLabel(chunk_), instr->FalseLabel(chunk_),
      class_name, input, temp, temp2);
 
  EmitBranch(instr, equal);
}
 
 
void LCodeGen::DoCmpMapAndBranch(LCmpMapAndBranch* instr) {
  Register reg = ToRegister(instr->value());
 
  __ Cmp(FieldOperand(reg, HeapObject::kMapOffset), instr->map());
  EmitBranch(instr, equal);
}
 
 
void LCodeGen::DoInstanceOf(LInstanceOf* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  InstanceofStub stub(isolate(), InstanceofStub::kNoFlags);
  __ Push(ToRegister(instr->left()));
  __ Push(ToRegister(instr->right()));
  CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
  Label true_value, done;
  __ testp(rax, rax);
  __ j(zero, &true_value, Label::kNear);
  __ LoadRoot(ToRegister(instr->result()), Heap::kFalseValueRootIndex);
  __ jmp(&done, Label::kNear);
  __ bind(&true_value);
  __ LoadRoot(ToRegister(instr->result()), Heap::kTrueValueRootIndex);
  __ bind(&done);
}
 
 
void LCodeGen::DoInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr) {
  class DeferredInstanceOfKnownGlobal FINAL : public LDeferredCode {
   public:
    DeferredInstanceOfKnownGlobal(LCodeGen* codegen,
                                  LInstanceOfKnownGlobal* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() OVERRIDE {
      codegen()->DoDeferredInstanceOfKnownGlobal(instr_, &map_check_);
    }
    virtual LInstruction* instr() OVERRIDE { return instr_; }
    Label* map_check() { return &map_check_; }
   private:
    LInstanceOfKnownGlobal* instr_;
    Label map_check_;
  };
 
  DCHECK(ToRegister(instr->context()).is(rsi));
  DeferredInstanceOfKnownGlobal* deferred;
  deferred = new(zone()) DeferredInstanceOfKnownGlobal(this, instr);
 
  Label done, false_result;
  Register object = ToRegister(instr->value());
 
  // A Smi is not an instance of anything.
  __ JumpIfSmi(object, &false_result, Label::kNear);
 
  // 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;
  // Use a temp register to avoid memory operands with variable lengths.
  Register map = ToRegister(instr->temp());
  __ movp(map, FieldOperand(object, HeapObject::kMapOffset));
  __ bind(deferred->map_check());  // Label for calculating code patching.
  Handle<Cell> cache_cell = factory()->NewCell(factory()->the_hole_value());
  __ Move(kScratchRegister, cache_cell, RelocInfo::CELL);
  __ cmpp(map, Operand(kScratchRegister, 0));
  __ j(not_equal, &cache_miss, Label::kNear);
  // Patched to load either true or false.
  __ LoadRoot(ToRegister(instr->result()), Heap::kTheHoleValueRootIndex);
#ifdef DEBUG
  // Check that the code size between patch label and patch sites is invariant.
  Label end_of_patched_code;
  __ bind(&end_of_patched_code);
  DCHECK(true);
#endif
  __ jmp(&done, Label::kNear);
 
  // 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.
  __ CompareRoot(object, Heap::kNullValueRootIndex);
  __ j(equal, &false_result, Label::kNear);
 
  // String values are not instances of anything.
  __ JumpIfNotString(object, kScratchRegister, deferred->entry());
 
  __ bind(&false_result);
  __ LoadRoot(ToRegister(instr->result()), Heap::kFalseValueRootIndex);
 
  __ bind(deferred->exit());
  __ bind(&done);
}
 
 
void LCodeGen::DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,
                                               Label* map_check) {
  {
    PushSafepointRegistersScope scope(this);
    InstanceofStub::Flags flags = static_cast<InstanceofStub::Flags>(
        InstanceofStub::kNoFlags | InstanceofStub::kCallSiteInlineCheck);
    InstanceofStub stub(isolate(), flags);
 
    __ Push(ToRegister(instr->value()));
    __ Push(instr->function());
 
    static const int kAdditionalDelta = kPointerSize == kInt64Size ? 10 : 16;
    int delta =
        masm_->SizeOfCodeGeneratedSince(map_check) + kAdditionalDelta;
    DCHECK(delta >= 0);
    __ PushImm32(delta);
 
    // We are pushing three values on the stack but recording a
    // safepoint with two arguments because stub is going to
    // remove the third argument from the stack before jumping
    // to instanceof builtin on the slow path.
    CallCodeGeneric(stub.GetCode(),
                    RelocInfo::CODE_TARGET,
                    instr,
                    RECORD_SAFEPOINT_WITH_REGISTERS,
                    2);
    DCHECK(delta == masm_->SizeOfCodeGeneratedSince(map_check));
    LEnvironment* env = instr->GetDeferredLazyDeoptimizationEnvironment();
    safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
    // Move result to a register that survives the end of the
    // PushSafepointRegisterScope.
    __ movp(kScratchRegister, rax);
  }
  __ testp(kScratchRegister, kScratchRegister);
  Label load_false;
  Label done;
  __ j(not_zero, &load_false, Label::kNear);
  __ LoadRoot(rax, Heap::kTrueValueRootIndex);
  __ jmp(&done, Label::kNear);
  __ bind(&load_false);
  __ LoadRoot(rax, Heap::kFalseValueRootIndex);
  __ bind(&done);
}
 
 
void LCodeGen::DoCmpT(LCmpT* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  Token::Value op = instr->op();
 
  Handle<Code> ic = CodeFactory::CompareIC(isolate(), op).code();
  CallCode(ic, RelocInfo::CODE_TARGET, instr);
 
  Condition condition = TokenToCondition(op, false);
  Label true_value, done;
  __ testp(rax, rax);
  __ j(condition, &true_value, Label::kNear);
  __ LoadRoot(ToRegister(instr->result()), Heap::kFalseValueRootIndex);
  __ jmp(&done, Label::kNear);
  __ bind(&true_value);
  __ LoadRoot(ToRegister(instr->result()), Heap::kTrueValueRootIndex);
  __ bind(&done);
}
 
 
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(rax);
    __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
    __ CallRuntime(Runtime::kTraceExit, 1);
  }
  if (info()->saves_caller_doubles()) {
    RestoreCallerDoubles();
  }
  int no_frame_start = -1;
  if (NeedsEagerFrame()) {
    __ movp(rsp, rbp);
    __ popq(rbp);
    no_frame_start = masm_->pc_offset();
  }
  if (instr->has_constant_parameter_count()) {
    __ Ret((ToInteger32(instr->constant_parameter_count()) + 1) * kPointerSize,
           rcx);
  } else {
    Register reg = ToRegister(instr->parameter_count());
    // The argument count parameter is a smi
    __ SmiToInteger32(reg, reg);
    Register return_addr_reg = reg.is(rcx) ? rbx : rcx;
    __ PopReturnAddressTo(return_addr_reg);
    __ shlp(reg, Immediate(kPointerSizeLog2));
    __ addp(rsp, reg);
    __ jmp(return_addr_reg);
  }
  if (no_frame_start != -1) {
    info_->AddNoFrameRange(no_frame_start, masm_->pc_offset());
  }
}
 
 
void LCodeGen::DoLoadGlobalCell(LLoadGlobalCell* instr) {
  Register result = ToRegister(instr->result());
  __ LoadGlobalCell(result, instr->hydrogen()->cell().handle());
  if (instr->hydrogen()->RequiresHoleCheck()) {
    __ CompareRoot(result, Heap::kTheHoleValueRootIndex);
    DeoptimizeIf(equal, instr, "hole");
  }
}
 
 
template <class T>
void LCodeGen::EmitVectorLoadICRegisters(T* instr) {
  DCHECK(FLAG_vector_ics);
  Register vector = ToRegister(instr->temp_vector());
  DCHECK(vector.is(VectorLoadICDescriptor::VectorRegister()));
  __ Move(vector, instr->hydrogen()->feedback_vector());
  // No need to allocate this register.
  DCHECK(VectorLoadICDescriptor::SlotRegister().is(rax));
  __ Move(VectorLoadICDescriptor::SlotRegister(),
          Smi::FromInt(instr->hydrogen()->slot()));
}
 
 
void LCodeGen::DoLoadGlobalGeneric(LLoadGlobalGeneric* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  DCHECK(ToRegister(instr->global_object())
             .is(LoadDescriptor::ReceiverRegister()));
  DCHECK(ToRegister(instr->result()).is(rax));
 
  __ Move(LoadDescriptor::NameRegister(), instr->name());
  if (FLAG_vector_ics) {
    EmitVectorLoadICRegisters<LLoadGlobalGeneric>(instr);
  }
  ContextualMode mode = instr->for_typeof() ? NOT_CONTEXTUAL : CONTEXTUAL;
  Handle<Code> ic = CodeFactory::LoadIC(isolate(), mode).code();
  CallCode(ic, RelocInfo::CODE_TARGET, instr);
}
 
 
void LCodeGen::DoStoreGlobalCell(LStoreGlobalCell* instr) {
  Register value = ToRegister(instr->value());
  Handle<Cell> cell_handle = instr->hydrogen()->cell().handle();
 
  // 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()) {
    // We have a temp because CompareRoot might clobber kScratchRegister.
    Register cell = ToRegister(instr->temp());
    DCHECK(!value.is(cell));
    __ Move(cell, cell_handle, RelocInfo::CELL);
    __ CompareRoot(Operand(cell, 0), Heap::kTheHoleValueRootIndex);
    DeoptimizeIf(equal, instr, "hole");
    // Store the value.
    __ movp(Operand(cell, 0), value);
  } else {
    // Store the value.
    __ Move(kScratchRegister, cell_handle, RelocInfo::CELL);
    __ movp(Operand(kScratchRegister, 0), value);
  }
  // Cells are always rescanned, so no write barrier here.
}
 
 
void LCodeGen::DoLoadContextSlot(LLoadContextSlot* instr) {
  Register context = ToRegister(instr->context());
  Register result = ToRegister(instr->result());
  __ movp(result, ContextOperand(context, instr->slot_index()));
  if (instr->hydrogen()->RequiresHoleCheck()) {
    __ CompareRoot(result, Heap::kTheHoleValueRootIndex);
    if (instr->hydrogen()->DeoptimizesOnHole()) {
      DeoptimizeIf(equal, instr, "hole");
    } else {
      Label is_not_hole;
      __ j(not_equal, &is_not_hole, Label::kNear);
      __ LoadRoot(result, Heap::kUndefinedValueRootIndex);
      __ bind(&is_not_hole);
    }
  }
}
 
 
void LCodeGen::DoStoreContextSlot(LStoreContextSlot* instr) {
  Register context = ToRegister(instr->context());
  Register value = ToRegister(instr->value());
 
  Operand target = ContextOperand(context, instr->slot_index());
 
  Label skip_assignment;
  if (instr->hydrogen()->RequiresHoleCheck()) {
    __ CompareRoot(target, Heap::kTheHoleValueRootIndex);
    if (instr->hydrogen()->DeoptimizesOnHole()) {
      DeoptimizeIf(equal, instr, "hole");
    } else {
      __ j(not_equal, &skip_assignment);
    }
  }
  __ movp(target, value);
 
  if (instr->hydrogen()->NeedsWriteBarrier()) {
    SmiCheck check_needed =
      instr->hydrogen()->value()->type().IsHeapObject()
          ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
    int offset = Context::SlotOffset(instr->slot_index());
    Register scratch = ToRegister(instr->temp());
    __ RecordWriteContextSlot(context,
                              offset,
                              value,
                              scratch,
                              kSaveFPRegs,
                              EMIT_REMEMBERED_SET,
                              check_needed);
  }
 
  __ bind(&skip_assignment);
}
 
 
void LCodeGen::DoLoadNamedField(LLoadNamedField* instr) {
  HObjectAccess access = instr->hydrogen()->access();
  int offset = access.offset();
 
  if (access.IsExternalMemory()) {
    Register result = ToRegister(instr->result());
    if (instr->object()->IsConstantOperand()) {
      DCHECK(result.is(rax));
      __ load_rax(ToExternalReference(LConstantOperand::cast(instr->object())));
    } else {
      Register object = ToRegister(instr->object());
      __ Load(result, MemOperand(object, offset), access.representation());
    }
    return;
  }
 
  Register object = ToRegister(instr->object());
  if (instr->hydrogen()->representation().IsDouble()) {
    XMMRegister result = ToDoubleRegister(instr->result());
    __ movsd(result, FieldOperand(object, offset));
    return;
  }
 
  Register result = ToRegister(instr->result());
  if (!access.IsInobject()) {
    __ movp(result, FieldOperand(object, JSObject::kPropertiesOffset));
    object = result;
  }
 
  Representation representation = access.representation();
  if (representation.IsSmi() && SmiValuesAre32Bits() &&
      instr->hydrogen()->representation().IsInteger32()) {
    if (FLAG_debug_code) {
      Register scratch = kScratchRegister;
      __ Load(scratch, FieldOperand(object, offset), representation);
      __ AssertSmi(scratch);
    }
 
    // Read int value directly from upper half of the smi.
    STATIC_ASSERT(kSmiTag == 0);
    DCHECK(kSmiTagSize + kSmiShiftSize == 32);
    offset += kPointerSize / 2;
    representation = Representation::Integer32();
  }
  __ Load(result, FieldOperand(object, offset), representation);
}
 
 
void LCodeGen::DoLoadNamedGeneric(LLoadNamedGeneric* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  DCHECK(ToRegister(instr->object()).is(LoadDescriptor::ReceiverRegister()));
  DCHECK(ToRegister(instr->result()).is(rax));
 
  __ Move(LoadDescriptor::NameRegister(), instr->name());
  if (FLAG_vector_ics) {
    EmitVectorLoadICRegisters<LLoadNamedGeneric>(instr);
  }
  Handle<Code> ic = CodeFactory::LoadIC(isolate(), NOT_CONTEXTUAL).code();
  CallCode(ic, RelocInfo::CODE_TARGET, instr);
}
 
 
void LCodeGen::DoLoadFunctionPrototype(LLoadFunctionPrototype* instr) {
  Register function = ToRegister(instr->function());
  Register result = ToRegister(instr->result());
 
  // Get the prototype or initial map from the function.
  __ movp(result,
         FieldOperand(function, JSFunction::kPrototypeOrInitialMapOffset));
 
  // Check that the function has a prototype or an initial map.
  __ CompareRoot(result, Heap::kTheHoleValueRootIndex);
  DeoptimizeIf(equal, instr, "hole");
 
  // If the function does not have an initial map, we're done.
  Label done;
  __ CmpObjectType(result, MAP_TYPE, kScratchRegister);
  __ j(not_equal, &done, Label::kNear);
 
  // Get the prototype from the initial map.
  __ movp(result, FieldOperand(result, Map::kPrototypeOffset));
 
  // All done.
  __ bind(&done);
}
 
 
void LCodeGen::DoLoadRoot(LLoadRoot* instr) {
  Register result = ToRegister(instr->result());
  __ LoadRoot(result, instr->index());
}
 
 
void LCodeGen::DoAccessArgumentsAt(LAccessArgumentsAt* instr) {
  Register arguments = ToRegister(instr->arguments());
  Register result = ToRegister(instr->result());
 
  if (instr->length()->IsConstantOperand() &&
      instr->index()->IsConstantOperand()) {
    int32_t const_index = ToInteger32(LConstantOperand::cast(instr->index()));
    int32_t const_length = ToInteger32(LConstantOperand::cast(instr->length()));
    if (const_index >= 0 && const_index < const_length) {
      StackArgumentsAccessor args(arguments, const_length,
                                  ARGUMENTS_DONT_CONTAIN_RECEIVER);
      __ movp(result, args.GetArgumentOperand(const_index));
    } else if (FLAG_debug_code) {
      __ int3();
    }
  } else {
    Register length = ToRegister(instr->length());
    // There are two words between the frame pointer and the last argument.
    // Subtracting from length accounts for one of them add one more.
    if (instr->index()->IsRegister()) {
      __ subl(length, ToRegister(instr->index()));
    } else {
      __ subl(length, ToOperand(instr->index()));
    }
    StackArgumentsAccessor args(arguments, length,
                                ARGUMENTS_DONT_CONTAIN_RECEIVER);
    __ movp(result, args.GetArgumentOperand(0));
  }
}
 
 
void LCodeGen::DoLoadKeyedExternalArray(LLoadKeyed* instr) {
  ElementsKind elements_kind = instr->elements_kind();
  LOperand* key = instr->key();
  if (kPointerSize == kInt32Size && !key->IsConstantOperand()) {
    Register key_reg = ToRegister(key);
    Representation key_representation =
        instr->hydrogen()->key()->representation();
    if (ExternalArrayOpRequiresTemp(key_representation, elements_kind)) {
      __ SmiToInteger64(key_reg, key_reg);
    } else if (instr->hydrogen()->IsDehoisted()) {
      // Sign extend key because it could be a 32 bit negative value
      // and the dehoisted address computation happens in 64 bits
      __ movsxlq(key_reg, key_reg);
    }
  }
  Operand operand(BuildFastArrayOperand(
      instr->elements(),
      key,
      instr->hydrogen()->key()->representation(),
      elements_kind,
      instr->base_offset()));
 
  if (elements_kind == EXTERNAL_FLOAT32_ELEMENTS ||
      elements_kind == FLOAT32_ELEMENTS) {
    XMMRegister result(ToDoubleRegister(instr->result()));
    __ movss(result, operand);
    __ cvtss2sd(result, result);
  } else if (elements_kind == EXTERNAL_FLOAT64_ELEMENTS ||
             elements_kind == FLOAT64_ELEMENTS) {
    __ movsd(ToDoubleRegister(instr->result()), operand);
  } else {
    Register result(ToRegister(instr->result()));
    switch (elements_kind) {
      case EXTERNAL_INT8_ELEMENTS:
      case INT8_ELEMENTS:
        __ movsxbl(result, operand);
        break;
      case EXTERNAL_UINT8_ELEMENTS:
      case EXTERNAL_UINT8_CLAMPED_ELEMENTS:
      case UINT8_ELEMENTS:
      case UINT8_CLAMPED_ELEMENTS:
        __ movzxbl(result, operand);
        break;
      case EXTERNAL_INT16_ELEMENTS:
      case INT16_ELEMENTS:
        __ movsxwl(result, operand);
        break;
      case EXTERNAL_UINT16_ELEMENTS:
      case UINT16_ELEMENTS:
        __ movzxwl(result, operand);
        break;
      case EXTERNAL_INT32_ELEMENTS:
      case INT32_ELEMENTS:
        __ movl(result, operand);
        break;
      case EXTERNAL_UINT32_ELEMENTS:
      case UINT32_ELEMENTS:
        __ movl(result, operand);
        if (!instr->hydrogen()->CheckFlag(HInstruction::kUint32)) {
          __ testl(result, result);
          DeoptimizeIf(negative, instr, "negative value");
        }
        break;
      case EXTERNAL_FLOAT32_ELEMENTS:
      case EXTERNAL_FLOAT64_ELEMENTS:
      case FLOAT32_ELEMENTS:
      case FLOAT64_ELEMENTS:
      case FAST_ELEMENTS:
      case FAST_SMI_ELEMENTS:
      case FAST_DOUBLE_ELEMENTS:
      case FAST_HOLEY_ELEMENTS:
      case FAST_HOLEY_SMI_ELEMENTS:
      case FAST_HOLEY_DOUBLE_ELEMENTS:
      case DICTIONARY_ELEMENTS:
      case SLOPPY_ARGUMENTS_ELEMENTS:
        UNREACHABLE();
        break;
    }
  }
}
 
 
void LCodeGen::DoLoadKeyedFixedDoubleArray(LLoadKeyed* instr) {
  XMMRegister result(ToDoubleRegister(instr->result()));
  LOperand* key = instr->key();
  if (kPointerSize == kInt32Size && !key->IsConstantOperand() &&
      instr->hydrogen()->IsDehoisted()) {
    // Sign extend key because it could be a 32 bit negative value
    // and the dehoisted address computation happens in 64 bits
    __ movsxlq(ToRegister(key), ToRegister(key));
  }
  if (instr->hydrogen()->RequiresHoleCheck()) {
    Operand hole_check_operand = BuildFastArrayOperand(
        instr->elements(),
        key,
        instr->hydrogen()->key()->representation(),
        FAST_DOUBLE_ELEMENTS,
        instr->base_offset() + sizeof(kHoleNanLower32));
    __ cmpl(hole_check_operand, Immediate(kHoleNanUpper32));
    DeoptimizeIf(equal, instr, "hole");
  }
 
  Operand double_load_operand = BuildFastArrayOperand(
      instr->elements(),
      key,
      instr->hydrogen()->key()->representation(),
      FAST_DOUBLE_ELEMENTS,
      instr->base_offset());
  __ movsd(result, double_load_operand);
}
 
 
void LCodeGen::DoLoadKeyedFixedArray(LLoadKeyed* instr) {
  HLoadKeyed* hinstr = instr->hydrogen();
  Register result = ToRegister(instr->result());
  LOperand* key = instr->key();
  bool requires_hole_check = hinstr->RequiresHoleCheck();
  Representation representation = hinstr->representation();
  int offset = instr->base_offset();
 
  if (kPointerSize == kInt32Size && !key->IsConstantOperand() &&
      instr->hydrogen()->IsDehoisted()) {
    // Sign extend key because it could be a 32 bit negative value
    // and the dehoisted address computation happens in 64 bits
    __ movsxlq(ToRegister(key), ToRegister(key));
  }
  if (representation.IsInteger32() && SmiValuesAre32Bits() &&
      hinstr->elements_kind() == FAST_SMI_ELEMENTS) {
    DCHECK(!requires_hole_check);
    if (FLAG_debug_code) {
      Register scratch = kScratchRegister;
      __ Load(scratch,
              BuildFastArrayOperand(instr->elements(),
                                    key,
                                    instr->hydrogen()->key()->representation(),
                                    FAST_ELEMENTS,
                                    offset),
              Representation::Smi());
      __ AssertSmi(scratch);
    }
    // Read int value directly from upper half of the smi.
    STATIC_ASSERT(kSmiTag == 0);
    DCHECK(kSmiTagSize + kSmiShiftSize == 32);
    offset += kPointerSize / 2;
  }
 
  __ Load(result,
          BuildFastArrayOperand(instr->elements(), key,
                                instr->hydrogen()->key()->representation(),
                                FAST_ELEMENTS, offset),
          representation);
 
  // Check for the hole value.
  if (requires_hole_check) {
    if (IsFastSmiElementsKind(hinstr->elements_kind())) {
      Condition smi = __ CheckSmi(result);
      DeoptimizeIf(NegateCondition(smi), instr, "not a Smi");
    } else {
      __ CompareRoot(result, Heap::kTheHoleValueRootIndex);
      DeoptimizeIf(equal, instr, "hole");
    }
  }
}
 
 
void LCodeGen::DoLoadKeyed(LLoadKeyed* instr) {
  if (instr->is_typed_elements()) {
    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) {
  Register elements_pointer_reg = ToRegister(elements_pointer);
  int shift_size = ElementsKindToShiftSize(elements_kind);
  if (key->IsConstantOperand()) {
    int32_t constant_value = ToInteger32(LConstantOperand::cast(key));
    if (constant_value & 0xF0000000) {
      Abort(kArrayIndexConstantValueTooBig);
    }
    return Operand(elements_pointer_reg,
                   (constant_value << shift_size) + offset);
  } else {
    // Take the tag bit into account while computing the shift size.
    if (key_representation.IsSmi() && (shift_size >= 1)) {
      DCHECK(SmiValuesAre31Bits());
      shift_size -= kSmiTagSize;
    }
    ScaleFactor scale_factor = static_cast<ScaleFactor>(shift_size);
    return Operand(elements_pointer_reg,
                   ToRegister(key),
                   scale_factor,
                   offset);
  }
}
 
 
void LCodeGen::DoLoadKeyedGeneric(LLoadKeyedGeneric* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  DCHECK(ToRegister(instr->object()).is(LoadDescriptor::ReceiverRegister()));
  DCHECK(ToRegister(instr->key()).is(LoadDescriptor::NameRegister()));
 
  if (FLAG_vector_ics) {
    EmitVectorLoadICRegisters<LLoadKeyedGeneric>(instr);
  }
 
  Handle<Code> ic = CodeFactory::KeyedLoadIC(isolate()).code();
  CallCode(ic, RelocInfo::CODE_TARGET, instr);
}
 
 
void LCodeGen::DoArgumentsElements(LArgumentsElements* instr) {
  Register result = ToRegister(instr->result());
 
  if (instr->hydrogen()->from_inlined()) {
    __ leap(result, Operand(rsp, -kFPOnStackSize + -kPCOnStackSize));
  } else {
    // Check for arguments adapter frame.
    Label done, adapted;
    __ movp(result, Operand(rbp, StandardFrameConstants::kCallerFPOffset));
    __ Cmp(Operand(result, StandardFrameConstants::kContextOffset),
           Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
    __ j(equal, &adapted, Label::kNear);
 
    // No arguments adaptor frame.
    __ movp(result, rbp);
    __ jmp(&done, Label::kNear);
 
    // Arguments adaptor frame present.
    __ bind(&adapted);
    __ movp(result, Operand(rbp, 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) {
  Register result = ToRegister(instr->result());
 
  Label done;
 
  // If no arguments adaptor frame the number of arguments is fixed.
  if (instr->elements()->IsRegister()) {
    __ cmpp(rbp, ToRegister(instr->elements()));
  } else {
    __ cmpp(rbp, ToOperand(instr->elements()));
  }
  __ movl(result, Immediate(scope()->num_parameters()));
  __ j(equal, &done, Label::kNear);
 
  // Arguments adaptor frame present. Get argument length from there.
  __ movp(result, Operand(rbp, StandardFrameConstants::kCallerFPOffset));
  __ SmiToInteger32(result,
                    Operand(result,
                            ArgumentsAdaptorFrameConstants::kLengthOffset));
 
  // Argument length is in result register.
  __ bind(&done);
}
 
 
void LCodeGen::DoWrapReceiver(LWrapReceiver* instr) {
  Register receiver = ToRegister(instr->receiver());
  Register function = ToRegister(instr->function());
 
  // 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;
  Label::Distance dist = DeoptEveryNTimes() ? Label::kFar : Label::kNear;
 
  if (!instr->hydrogen()->known_function()) {
    // Do not transform the receiver to object for strict mode
    // functions.
    __ movp(kScratchRegister,
            FieldOperand(function, JSFunction::kSharedFunctionInfoOffset));
    __ testb(FieldOperand(kScratchRegister,
                          SharedFunctionInfo::kStrictModeByteOffset),
             Immediate(1 << SharedFunctionInfo::kStrictModeBitWithinByte));
    __ j(not_equal, &receiver_ok, dist);
 
    // Do not transform the receiver to object for builtins.
    __ testb(FieldOperand(kScratchRegister,
                          SharedFunctionInfo::kNativeByteOffset),
             Immediate(1 << SharedFunctionInfo::kNativeBitWithinByte));
    __ j(not_equal, &receiver_ok, dist);
  }
 
  // Normal function. Replace undefined or null with global receiver.
  __ CompareRoot(receiver, Heap::kNullValueRootIndex);
  __ j(equal, &global_object, Label::kNear);
  __ CompareRoot(receiver, Heap::kUndefinedValueRootIndex);
  __ j(equal, &global_object, Label::kNear);
 
  // The receiver should be a JS object.
  Condition is_smi = __ CheckSmi(receiver);
  DeoptimizeIf(is_smi, instr, "Smi");
  __ CmpObjectType(receiver, FIRST_SPEC_OBJECT_TYPE, kScratchRegister);
  DeoptimizeIf(below, instr, "not a JavaScript object");
 
  __ jmp(&receiver_ok, Label::kNear);
  __ bind(&global_object);
  __ movp(receiver, FieldOperand(function, JSFunction::kContextOffset));
  __ movp(receiver,
          Operand(receiver,
                  Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)));
  __ movp(receiver, FieldOperand(receiver, GlobalObject::kGlobalProxyOffset));
 
  __ 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());
  DCHECK(receiver.is(rax));  // Used for parameter count.
  DCHECK(function.is(rdi));  // Required by InvokeFunction.
  DCHECK(ToRegister(instr->result()).is(rax));
 
  // Copy the arguments to this function possibly from the
  // adaptor frame below it.
  const uint32_t kArgumentsLimit = 1 * KB;
  __ cmpp(length, Immediate(kArgumentsLimit));
  DeoptimizeIf(above, instr, "too many arguments");
 
  __ Push(receiver);
  __ movp(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.
  __ testl(length, length);
  __ j(zero, &invoke, Label::kNear);
  __ bind(&loop);
  StackArgumentsAccessor args(elements, length,
                              ARGUMENTS_DONT_CONTAIN_RECEIVER);
  __ Push(args.GetArgumentOperand(0));
  __ decl(length);
  __ j(not_zero, &loop);
 
  // Invoke the function.
  __ bind(&invoke);
  DCHECK(instr->HasPointerMap());
  LPointerMap* pointers = instr->pointer_map();
  SafepointGenerator safepoint_generator(
      this, pointers, Safepoint::kLazyDeopt);
  ParameterCount actual(rax);
  __ InvokeFunction(function, actual, CALL_FUNCTION, safepoint_generator);
}
 
 
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());
  __ movp(result, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
}
 
 
void LCodeGen::DoContext(LContext* instr) {
  Register result = ToRegister(instr->result());
  if (info()->IsOptimizing()) {
    __ movp(result, Operand(rbp, StandardFrameConstants::kContextOffset));
  } else {
    // If there is no frame, the context must be in rsi.
    DCHECK(result.is(rsi));
  }
}
 
 
void LCodeGen::DoDeclareGlobals(LDeclareGlobals* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  __ Push(rsi);  // The context is the first argument.
  __ Push(instr->hydrogen()->pairs());
  __ Push(Smi::FromInt(instr->hydrogen()->flags()));
  CallRuntime(Runtime::kDeclareGlobals, 3, instr);
}
 
 
void LCodeGen::CallKnownFunction(Handle<JSFunction> function,
                                 int formal_parameter_count,
                                 int arity,
                                 LInstruction* instr,
                                 RDIState rdi_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();
 
  if (can_invoke_directly) {
    if (rdi_state == RDI_UNINITIALIZED) {
      __ Move(rdi, function);
    }
 
    // Change context.
    __ movp(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
 
    // Set rax to arguments count if adaption is not needed. Assumes that rax
    // is available to write to at this point.
    if (dont_adapt_arguments) {
      __ Set(rax, arity);
    }
 
    // Invoke function.
    if (function.is_identical_to(info()->closure())) {
      __ CallSelf();
    } else {
      __ Call(FieldOperand(rdi, JSFunction::kCodeEntryOffset));
    }
 
    // Set up deoptimization.
    RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT, 0);
  } 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);
  }
}
 
 
void LCodeGen::DoTailCallThroughMegamorphicCache(
    LTailCallThroughMegamorphicCache* instr) {
  Register receiver = ToRegister(instr->receiver());
  Register name = ToRegister(instr->name());
  DCHECK(receiver.is(LoadDescriptor::ReceiverRegister()));
  DCHECK(name.is(LoadDescriptor::NameRegister()));
 
  Register scratch = rbx;
  DCHECK(!scratch.is(receiver) && !scratch.is(name));
 
  // Important for the tail-call.
  bool must_teardown_frame = NeedsEagerFrame();
 
  // The probe will tail call to a handler if found.
  isolate()->stub_cache()->GenerateProbe(masm(), instr->hydrogen()->flags(),
                                         must_teardown_frame, receiver, name,
                                         scratch, no_reg);
 
  // Tail call to miss if we ended up here.
  if (must_teardown_frame) __ leave();
  LoadIC::GenerateMiss(masm());
}
 
 
void LCodeGen::DoCallWithDescriptor(LCallWithDescriptor* instr) {
  DCHECK(ToRegister(instr->result()).is(rax));
 
  LPointerMap* pointers = instr->pointer_map();
  SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
 
  if (instr->target()->IsConstantOperand()) {
    LConstantOperand* target = LConstantOperand::cast(instr->target());
    Handle<Code> code = Handle<Code>::cast(ToHandle(target));
    generator.BeforeCall(__ CallSize(code));
    __ call(code, RelocInfo::CODE_TARGET);
  } else {
    DCHECK(instr->target()->IsRegister());
    Register target = ToRegister(instr->target());
    generator.BeforeCall(__ CallSize(target));
    __ addp(target, Immediate(Code::kHeaderSize - kHeapObjectTag));
    __ call(target);
  }
  generator.AfterCall();
}
 
 
void LCodeGen::DoCallJSFunction(LCallJSFunction* instr) {
  DCHECK(ToRegister(instr->function()).is(rdi));
  DCHECK(ToRegister(instr->result()).is(rax));
 
  if (instr->hydrogen()->pass_argument_count()) {
    __ Set(rax, instr->arity());
  }
 
  // Change context.
  __ movp(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
 
  LPointerMap* pointers = instr->pointer_map();
  SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
 
  bool is_self_call = false;
  if (instr->hydrogen()->function()->IsConstant()) {
    Handle<JSFunction> jsfun = Handle<JSFunction>::null();
    HConstant* fun_const = HConstant::cast(instr->hydrogen()->function());
    jsfun = Handle<JSFunction>::cast(fun_const->handle(isolate()));
    is_self_call = jsfun.is_identical_to(info()->closure());
  }
 
  if (is_self_call) {
    __ CallSelf();
  } else {
    Operand target = FieldOperand(rdi, JSFunction::kCodeEntryOffset);
    generator.BeforeCall(__ CallSize(target));
    __ Call(target);
  }
  generator.AfterCall();
}
 
 
void LCodeGen::DoDeferredMathAbsTaggedHeapNumber(LMathAbs* instr) {
  Register input_reg = ToRegister(instr->value());
  __ CompareRoot(FieldOperand(input_reg, HeapObject::kMapOffset),
                 Heap::kHeapNumberMapRootIndex);
  DeoptimizeIf(not_equal, instr, "not a heap number");
 
  Label slow, allocated, done;
  Register tmp = input_reg.is(rax) ? rcx : rax;
  Register tmp2 = tmp.is(rcx) ? rdx : input_reg.is(rcx) ? rdx : rcx;
 
  // Preserve the value of all registers.
  PushSafepointRegistersScope scope(this);
 
  __ movl(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.
  __ testl(tmp, Immediate(HeapNumber::kSignMask));
  __ j(zero, &done);
 
  __ AllocateHeapNumber(tmp, tmp2, &slow);
  __ jmp(&allocated, Label::kNear);
 
  // 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(rax)) __ movp(tmp, rax);
  // Restore input_reg after call to runtime.
  __ LoadFromSafepointRegisterSlot(input_reg, input_reg);
 
  __ bind(&allocated);
  __ movq(tmp2, FieldOperand(input_reg, HeapNumber::kValueOffset));
  __ shlq(tmp2, Immediate(1));
  __ shrq(tmp2, Immediate(1));
  __ movq(FieldOperand(tmp, HeapNumber::kValueOffset), tmp2);
  __ StoreToSafepointRegisterSlot(input_reg, tmp);
 
  __ bind(&done);
}
 
 
void LCodeGen::EmitIntegerMathAbs(LMathAbs* instr) {
  Register input_reg = ToRegister(instr->value());
  __ testl(input_reg, input_reg);
  Label is_positive;
  __ j(not_sign, &is_positive, Label::kNear);
  __ negl(input_reg);  // Sets flags.
  DeoptimizeIf(negative, instr, "overflow");
  __ bind(&is_positive);
}
 
 
void LCodeGen::EmitSmiMathAbs(LMathAbs* instr) {
  Register input_reg = ToRegister(instr->value());
  __ testp(input_reg, input_reg);
  Label is_positive;
  __ j(not_sign, &is_positive, Label::kNear);
  __ negp(input_reg);  // Sets flags.
  DeoptimizeIf(negative, instr, "overflow");
  __ bind(&is_positive);
}
 
 
void LCodeGen::DoMathAbs(LMathAbs* instr) {
  // Class for deferred case.
  class DeferredMathAbsTaggedHeapNumber FINAL : public LDeferredCode {
   public:
    DeferredMathAbsTaggedHeapNumber(LCodeGen* codegen, LMathAbs* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() OVERRIDE {
      codegen()->DoDeferredMathAbsTaggedHeapNumber(instr_);
    }
    virtual LInstruction* instr() OVERRIDE { return instr_; }
   private:
    LMathAbs* instr_;
  };
 
  DCHECK(instr->value()->Equals(instr->result()));
  Representation r = instr->hydrogen()->value()->representation();
 
  if (r.IsDouble()) {
    XMMRegister scratch = double_scratch0();
    XMMRegister input_reg = ToDoubleRegister(instr->value());
    __ xorps(scratch, scratch);
    __ subsd(scratch, input_reg);
    __ andps(input_reg, scratch);
  } else if (r.IsInteger32()) {
    EmitIntegerMathAbs(instr);
  } else if (r.IsSmi()) {
    EmitSmiMathAbs(instr);
  } else {  // Tagged case.
    DeferredMathAbsTaggedHeapNumber* deferred =
        new(zone()) DeferredMathAbsTaggedHeapNumber(this, instr);
    Register input_reg = ToRegister(instr->value());
    // Smi check.
    __ JumpIfNotSmi(input_reg, deferred->entry());
    EmitSmiMathAbs(instr);
    __ bind(deferred->exit());
  }
}
 
 
void LCodeGen::DoMathFloor(LMathFloor* instr) {
  XMMRegister xmm_scratch = double_scratch0();
  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 if minus zero.
      __ movq(output_reg, input_reg);
      __ subq(output_reg, Immediate(1));
      DeoptimizeIf(overflow, instr, "minus zero");
    }
    __ roundsd(xmm_scratch, input_reg, Assembler::kRoundDown);
    __ cvttsd2si(output_reg, xmm_scratch);
    __ cmpl(output_reg, Immediate(0x1));
    DeoptimizeIf(overflow, instr, "overflow");
  } 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, "NaN");
    __ 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);
      __ testq(output_reg, Immediate(1));
      DeoptimizeIf(not_zero, instr, "minus zero");
      __ Set(output_reg, 0);
      __ jmp(&done);
      __ bind(&positive_sign);
    }
 
    // Use truncating instruction (OK because input is positive).
    __ cvttsd2si(output_reg, input_reg);
    // Overflow is signalled with minint.
    __ cmpl(output_reg, Immediate(0x1));
    DeoptimizeIf(overflow, instr, "overflow");
    __ jmp(&done, Label::kNear);
 
    // Non-zero negative reaches here.
    __ bind(&negative_sign);
    // Truncate, then compare and compensate.
    __ cvttsd2si(output_reg, input_reg);
    __ Cvtlsi2sd(xmm_scratch, output_reg);
    __ ucomisd(input_reg, xmm_scratch);
    __ j(equal, &done, Label::kNear);
    __ subl(output_reg, Immediate(1));
    DeoptimizeIf(overflow, instr, "overflow");
 
    __ bind(&done);
  }
}
 
 
void LCodeGen::DoMathRound(LMathRound* instr) {
  const XMMRegister xmm_scratch = double_scratch0();
  Register output_reg = ToRegister(instr->result());
  XMMRegister input_reg = ToDoubleRegister(instr->value());
  XMMRegister input_temp = ToDoubleRegister(instr->temp());
  static int64_t one_half = V8_INT64_C(0x3FE0000000000000);  // 0.5
  static int64_t minus_one_half = V8_INT64_C(0xBFE0000000000000);  // -0.5
 
  Label done, round_to_zero, below_one_half;
  Label::Distance dist = DeoptEveryNTimes() ? Label::kFar : Label::kNear;
  __ movq(kScratchRegister, one_half);
  __ movq(xmm_scratch, kScratchRegister);
  __ ucomisd(xmm_scratch, input_reg);
  __ j(above, &below_one_half, Label::kNear);
 
  // CVTTSD2SI rounds towards zero, since 0.5 <= x, we use floor(0.5 + x).
  __ addsd(xmm_scratch, input_reg);
  __ cvttsd2si(output_reg, xmm_scratch);
  // Overflow is signalled with minint.
  __ cmpl(output_reg, Immediate(0x1));
  DeoptimizeIf(overflow, instr, "overflow");
  __ jmp(&done, dist);
 
  __ bind(&below_one_half);
  __ movq(kScratchRegister, minus_one_half);
  __ movq(xmm_scratch, kScratchRegister);
  __ ucomisd(xmm_scratch, input_reg);
  __ j(below_equal, &round_to_zero, Label::kNear);
 
  // CVTTSD2SI rounds towards zero, we use ceil(x - (-0.5)) and then
  // compare and compensate.
  __ movq(input_temp, input_reg);  // Do not alter input_reg.
  __ subsd(input_temp, xmm_scratch);
  __ cvttsd2si(output_reg, input_temp);
  // Catch minint due to overflow, and to prevent overflow when compensating.
  __ cmpl(output_reg, Immediate(0x1));
  DeoptimizeIf(overflow, instr, "overflow");
 
  __ Cvtlsi2sd(xmm_scratch, output_reg);
  __ ucomisd(xmm_scratch, input_temp);
  __ j(equal, &done, dist);
  __ subl(output_reg, Immediate(1));
  // No overflow because we already ruled out minint.
  __ jmp(&done, dist);
 
  __ 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)) {
    __ movq(output_reg, input_reg);
    __ testq(output_reg, output_reg);
    DeoptimizeIf(negative, instr, "minus zero");
  }
  __ Set(output_reg, 0);
  __ bind(&done);
}
 
 
void LCodeGen::DoMathFround(LMathFround* instr) {
  XMMRegister input_reg = ToDoubleRegister(instr->value());
  XMMRegister output_reg = ToDoubleRegister(instr->result());
  __ cvtsd2ss(output_reg, input_reg);
  __ cvtss2sd(output_reg, output_reg);
}
 
 
void LCodeGen::DoMathSqrt(LMathSqrt* instr) {
  XMMRegister output = ToDoubleRegister(instr->result());
  if (instr->value()->IsDoubleRegister()) {
    XMMRegister input = ToDoubleRegister(instr->value());
    __ sqrtsd(output, input);
  } else {
    Operand input = ToOperand(instr->value());
    __ sqrtsd(output, input);
  }
}
 
 
void LCodeGen::DoMathPowHalf(LMathPowHalf* instr) {
  XMMRegister xmm_scratch = double_scratch0();
  XMMRegister input_reg = ToDoubleRegister(instr->value());
  DCHECK(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, double-precision
  // -Infinity has the highest 12 bits set and the lowest 52 bits cleared.
  __ movq(kScratchRegister, V8_INT64_C(0xFFF0000000000000));
  __ movq(xmm_scratch, kScratchRegister);
  __ ucomisd(xmm_scratch, input_reg);
  // 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.
 
  Register tagged_exponent = MathPowTaggedDescriptor::exponent();
  DCHECK(!instr->right()->IsRegister() ||
         ToRegister(instr->right()).is(tagged_exponent));
  DCHECK(!instr->right()->IsDoubleRegister() ||
         ToDoubleRegister(instr->right()).is(xmm1));
  DCHECK(ToDoubleRegister(instr->left()).is(xmm2));
  DCHECK(ToDoubleRegister(instr->result()).is(xmm3));
 
  if (exponent_type.IsSmi()) {
    MathPowStub stub(isolate(), MathPowStub::TAGGED);
    __ CallStub(&stub);
  } else if (exponent_type.IsTagged()) {
    Label no_deopt;
    __ JumpIfSmi(tagged_exponent, &no_deopt, Label::kNear);
    __ CmpObjectType(tagged_exponent, HEAP_NUMBER_TYPE, rcx);
    DeoptimizeIf(not_equal, instr, "not a heap number");
    __ bind(&no_deopt);
    MathPowStub stub(isolate(), MathPowStub::TAGGED);
    __ CallStub(&stub);
  } else if (exponent_type.IsInteger32()) {
    MathPowStub stub(isolate(), MathPowStub::INTEGER);
    __ CallStub(&stub);
  } else {
    DCHECK(exponent_type.IsDouble());
    MathPowStub stub(isolate(), MathPowStub::DOUBLE);
    __ CallStub(&stub);
  }
}
 
 
void LCodeGen::DoMathExp(LMathExp* instr) {
  XMMRegister input = ToDoubleRegister(instr->value());
  XMMRegister result = ToDoubleRegister(instr->result());
  XMMRegister temp0 = double_scratch0();
  Register temp1 = ToRegister(instr->temp1());
  Register temp2 = ToRegister(instr->temp2());
 
  MathExpGenerator::EmitMathExp(masm(), input, result, temp0, temp1, temp2);
}
 
 
void LCodeGen::DoMathLog(LMathLog* instr) {
  DCHECK(instr->value()->Equals(instr->result()));
  XMMRegister input_reg = ToDoubleRegister(instr->value());
  XMMRegister xmm_scratch = double_scratch0();
  Label positive, done, zero;
  __ xorps(xmm_scratch, xmm_scratch);
  __ ucomisd(input_reg, xmm_scratch);
  __ j(above, &positive, Label::kNear);
  __ j(not_carry, &zero, Label::kNear);
  ExternalReference nan =
      ExternalReference::address_of_canonical_non_hole_nan();
  Operand nan_operand = masm()->ExternalOperand(nan);
  __ movsd(input_reg, nan_operand);
  __ jmp(&done, Label::kNear);
  __ bind(&zero);
  ExternalReference ninf =
      ExternalReference::address_of_negative_infinity();
  Operand ninf_operand = masm()->ExternalOperand(ninf);
  __ movsd(input_reg, ninf_operand);
  __ jmp(&done, Label::kNear);
  __ bind(&positive);
  __ fldln2();
  __ subp(rsp, Immediate(kDoubleSize));
  __ movsd(Operand(rsp, 0), input_reg);
  __ fld_d(Operand(rsp, 0));
  __ fyl2x();
  __ fstp_d(Operand(rsp, 0));
  __ movsd(input_reg, Operand(rsp, 0));
  __ addp(rsp, Immediate(kDoubleSize));
  __ bind(&done);
}
 
 
void LCodeGen::DoMathClz32(LMathClz32* instr) {
  Register input = ToRegister(instr->value());
  Register result = ToRegister(instr->result());
  Label not_zero_input;
  __ bsrl(result, input);
 
  __ j(not_zero, &not_zero_input);
  __ Set(result, 63);  // 63^31 == 32
 
  __ bind(&not_zero_input);
  __ xorl(result, Immediate(31));  // for x in [0..31], 31^x == 31-x.
}
 
 
void LCodeGen::DoInvokeFunction(LInvokeFunction* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  DCHECK(ToRegister(instr->function()).is(rdi));
  DCHECK(instr->HasPointerMap());
 
  Handle<JSFunction> known_function = instr->hydrogen()->known_function();
  if (known_function.is_null()) {
    LPointerMap* pointers = instr->pointer_map();
    SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
    ParameterCount count(instr->arity());
    __ InvokeFunction(rdi, count, CALL_FUNCTION, generator);
  } else {
    CallKnownFunction(known_function,
                      instr->hydrogen()->formal_parameter_count(),
                      instr->arity(),
                      instr,
                      RDI_CONTAINS_TARGET);
  }
}
 
 
void LCodeGen::DoCallFunction(LCallFunction* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  DCHECK(ToRegister(instr->function()).is(rdi));
  DCHECK(ToRegister(instr->result()).is(rax));
 
  int arity = instr->arity();
  CallFunctionStub stub(isolate(), arity, instr->hydrogen()->function_flags());
  CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
}
 
 
void LCodeGen::DoCallNew(LCallNew* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  DCHECK(ToRegister(instr->constructor()).is(rdi));
  DCHECK(ToRegister(instr->result()).is(rax));
 
  __ Set(rax, instr->arity());
  // No cell in ebx for construct type feedback in optimized code
  __ LoadRoot(rbx, Heap::kUndefinedValueRootIndex);
  CallConstructStub stub(isolate(), NO_CALL_CONSTRUCTOR_FLAGS);
  CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
}
 
 
void LCodeGen::DoCallNewArray(LCallNewArray* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  DCHECK(ToRegister(instr->constructor()).is(rdi));
  DCHECK(ToRegister(instr->result()).is(rax));
 
  __ Set(rax, instr->arity());
  __ LoadRoot(rbx, Heap::kUndefinedValueRootIndex);
  ElementsKind kind = instr->hydrogen()->elements_kind();
  AllocationSiteOverrideMode override_mode =
      (AllocationSite::GetMode(kind) == TRACK_ALLOCATION_SITE)
          ? DISABLE_ALLOCATION_SITES
          : DONT_OVERRIDE;
 
  if (instr->arity() == 0) {
    ArrayNoArgumentConstructorStub stub(isolate(), kind, override_mode);
    CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
  } else if (instr->arity() == 1) {
    Label done;
    if (IsFastPackedElementsKind(kind)) {
      Label packed_case;
      // We might need a change here
      // look at the first argument
      __ movp(rcx, Operand(rsp, 0));
      __ testp(rcx, rcx);
      __ j(zero, &packed_case, Label::kNear);
 
      ElementsKind holey_kind = GetHoleyElementsKind(kind);
      ArraySingleArgumentConstructorStub stub(isolate(),
                                              holey_kind,
                                              override_mode);
      CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
      __ jmp(&done, Label::kNear);
      __ bind(&packed_case);
    }
 
    ArraySingleArgumentConstructorStub stub(isolate(), kind, override_mode);
    CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
    __ bind(&done);
  } else {
    ArrayNArgumentsConstructorStub stub(isolate(), kind, override_mode);
    CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
  }
}
 
 
void LCodeGen::DoCallRuntime(LCallRuntime* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  CallRuntime(instr->function(), instr->arity(), instr, instr->save_doubles());
}
 
 
void LCodeGen::DoStoreCodeEntry(LStoreCodeEntry* instr) {
  Register function = ToRegister(instr->function());
  Register code_object = ToRegister(instr->code_object());
  __ leap(code_object, FieldOperand(code_object, Code::kHeaderSize));
  __ movp(FieldOperand(function, JSFunction::kCodeEntryOffset), code_object);
}
 
 
void LCodeGen::DoInnerAllocatedObject(LInnerAllocatedObject* instr) {
  Register result = ToRegister(instr->result());
  Register base = ToRegister(instr->base_object());
  if (instr->offset()->IsConstantOperand()) {
    LConstantOperand* offset = LConstantOperand::cast(instr->offset());
    __ leap(result, Operand(base, ToInteger32(offset)));
  } else {
    Register offset = ToRegister(instr->offset());
    __ leap(result, Operand(base, offset, times_1, 0));
  }
}
 
 
void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
  HStoreNamedField* hinstr = instr->hydrogen();
  Representation representation = instr->representation();
 
  HObjectAccess access = hinstr->access();
  int offset = access.offset();
 
  if (access.IsExternalMemory()) {
    DCHECK(!hinstr->NeedsWriteBarrier());
    Register value = ToRegister(instr->value());
    if (instr->object()->IsConstantOperand()) {
      DCHECK(value.is(rax));
      LConstantOperand* object = LConstantOperand::cast(instr->object());
      __ store_rax(ToExternalReference(object));
    } else {
      Register object = ToRegister(instr->object());
      __ Store(MemOperand(object, offset), value, representation);
    }
    return;
  }
 
  Register object = ToRegister(instr->object());
  __ AssertNotSmi(object);
 
  DCHECK(!representation.IsSmi() ||
         !instr->value()->IsConstantOperand() ||
         IsInteger32Constant(LConstantOperand::cast(instr->value())));
  if (representation.IsDouble()) {
    DCHECK(access.IsInobject());
    DCHECK(!hinstr->has_transition());
    DCHECK(!hinstr->NeedsWriteBarrier());
    XMMRegister value = ToDoubleRegister(instr->value());
    __ movsd(FieldOperand(object, offset), value);
    return;
  }
 
  if (hinstr->has_transition()) {
    Handle<Map> transition = hinstr->transition_map();
    AddDeprecationDependency(transition);
    if (!hinstr->NeedsWriteBarrierForMap()) {
      __ Move(FieldOperand(object, HeapObject::kMapOffset), transition);
    } else {
      Register temp = ToRegister(instr->temp());
      __ Move(kScratchRegister, transition);
      __ movp(FieldOperand(object, HeapObject::kMapOffset), kScratchRegister);
      // Update the write barrier for the map field.
      __ RecordWriteForMap(object,
                           kScratchRegister,
                           temp,
                           kSaveFPRegs);
    }
  }
 
  // Do the store.
  Register write_register = object;
  if (!access.IsInobject()) {
    write_register = ToRegister(instr->temp());
    __ movp(write_register, FieldOperand(object, JSObject::kPropertiesOffset));
  }
 
  if (representation.IsSmi() && SmiValuesAre32Bits() &&
      hinstr->value()->representation().IsInteger32()) {
    DCHECK(hinstr->store_mode() == STORE_TO_INITIALIZED_ENTRY);
    if (FLAG_debug_code) {
      Register scratch = kScratchRegister;
      __ Load(scratch, FieldOperand(write_register, offset), representation);
      __ AssertSmi(scratch);
    }
    // Store int value directly to upper half of the smi.
    STATIC_ASSERT(kSmiTag == 0);
    DCHECK(kSmiTagSize + kSmiShiftSize == 32);
    offset += kPointerSize / 2;
    representation = Representation::Integer32();
  }
 
  Operand operand = FieldOperand(write_register, offset);
 
  if (instr->value()->IsRegister()) {
    Register value = ToRegister(instr->value());
    __ Store(operand, value, representation);
  } else {
    LConstantOperand* operand_value = LConstantOperand::cast(instr->value());
    if (IsInteger32Constant(operand_value)) {
      DCHECK(!hinstr->NeedsWriteBarrier());
      int32_t value = ToInteger32(operand_value);
      if (representation.IsSmi()) {
        __ Move(operand, Smi::FromInt(value));
 
      } else {
        __ movl(operand, Immediate(value));
      }
 
    } else {
      Handle<Object> handle_value = ToHandle(operand_value);
      DCHECK(!hinstr->NeedsWriteBarrier());
      __ Move(operand, handle_value);
    }
  }
 
  if (hinstr->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,
                        kSaveFPRegs,
                        EMIT_REMEMBERED_SET,
                        hinstr->SmiCheckForWriteBarrier(),
                        hinstr->PointersToHereCheckForValue());
  }
}
 
 
void LCodeGen::DoStoreNamedGeneric(LStoreNamedGeneric* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  DCHECK(ToRegister(instr->object()).is(StoreDescriptor::ReceiverRegister()));
  DCHECK(ToRegister(instr->value()).is(StoreDescriptor::ValueRegister()));
 
  __ Move(StoreDescriptor::NameRegister(), instr->hydrogen()->name());
  Handle<Code> ic = StoreIC::initialize_stub(isolate(), instr->strict_mode());
  CallCode(ic, RelocInfo::CODE_TARGET, instr);
}
 
 
void LCodeGen::DoBoundsCheck(LBoundsCheck* instr) {
  Representation representation = instr->hydrogen()->length()->representation();
  DCHECK(representation.Equals(instr->hydrogen()->index()->representation()));
  DCHECK(representation.IsSmiOrInteger32());
 
  Condition cc = instr->hydrogen()->allow_equality() ? below : below_equal;
  if (instr->length()->IsConstantOperand()) {
    int32_t length = ToInteger32(LConstantOperand::cast(instr->length()));
    Register index = ToRegister(instr->index());
    if (representation.IsSmi()) {
      __ Cmp(index, Smi::FromInt(length));
    } else {
      __ cmpl(index, Immediate(length));
    }
    cc = CommuteCondition(cc);
  } else if (instr->index()->IsConstantOperand()) {
    int32_t index = ToInteger32(LConstantOperand::cast(instr->index()));
    if (instr->length()->IsRegister()) {
      Register length = ToRegister(instr->length());
      if (representation.IsSmi()) {
        __ Cmp(length, Smi::FromInt(index));
      } else {
        __ cmpl(length, Immediate(index));
      }
    } else {
      Operand length = ToOperand(instr->length());
      if (representation.IsSmi()) {
        __ Cmp(length, Smi::FromInt(index));
      } else {
        __ cmpl(length, Immediate(index));
      }
    }
  } else {
    Register index = ToRegister(instr->index());
    if (instr->length()->IsRegister()) {
      Register length = ToRegister(instr->length());
      if (representation.IsSmi()) {
        __ cmpp(length, index);
      } else {
        __ cmpl(length, index);
      }
    } else {
      Operand length = ToOperand(instr->length());
      if (representation.IsSmi()) {
        __ cmpp(length, index);
      } else {
        __ cmpl(length, index);
      }
    }
  }
  if (FLAG_debug_code && instr->hydrogen()->skip_check()) {
    Label done;
    __ j(NegateCondition(cc), &done, Label::kNear);
    __ int3();
    __ bind(&done);
  } else {
    DeoptimizeIf(cc, instr, "out of bounds");
  }
}
 
 
void LCodeGen::DoStoreKeyedExternalArray(LStoreKeyed* instr) {
  ElementsKind elements_kind = instr->elements_kind();
  LOperand* key = instr->key();
  if (kPointerSize == kInt32Size && !key->IsConstantOperand()) {
    Register key_reg = ToRegister(key);
    Representation key_representation =
        instr->hydrogen()->key()->representation();
    if (ExternalArrayOpRequiresTemp(key_representation, elements_kind)) {
      __ SmiToInteger64(key_reg, key_reg);
    } else if (instr->hydrogen()->IsDehoisted()) {
      // Sign extend key because it could be a 32 bit negative value
      // and the dehoisted address computation happens in 64 bits
      __ movsxlq(key_reg, key_reg);
    }
  }
  Operand operand(BuildFastArrayOperand(
      instr->elements(),
      key,
      instr->hydrogen()->key()->representation(),
      elements_kind,
      instr->base_offset()));
 
  if (elements_kind == EXTERNAL_FLOAT32_ELEMENTS ||
      elements_kind == FLOAT32_ELEMENTS) {
    XMMRegister value(ToDoubleRegister(instr->value()));
    __ cvtsd2ss(value, value);
    __ movss(operand, value);
  } else if (elements_kind == EXTERNAL_FLOAT64_ELEMENTS ||
             elements_kind == FLOAT64_ELEMENTS) {
    __ movsd(operand, ToDoubleRegister(instr->value()));
  } else {
    Register value(ToRegister(instr->value()));
    switch (elements_kind) {
      case EXTERNAL_UINT8_CLAMPED_ELEMENTS:
      case EXTERNAL_INT8_ELEMENTS:
      case EXTERNAL_UINT8_ELEMENTS:
      case INT8_ELEMENTS:
      case UINT8_ELEMENTS:
      case UINT8_CLAMPED_ELEMENTS:
        __ movb(operand, value);
        break;
      case EXTERNAL_INT16_ELEMENTS:
      case EXTERNAL_UINT16_ELEMENTS:
      case INT16_ELEMENTS:
      case UINT16_ELEMENTS:
        __ movw(operand, value);
        break;
      case EXTERNAL_INT32_ELEMENTS:
      case EXTERNAL_UINT32_ELEMENTS:
      case INT32_ELEMENTS:
      case UINT32_ELEMENTS:
        __ movl(operand, value);
        break;
      case EXTERNAL_FLOAT32_ELEMENTS:
      case EXTERNAL_FLOAT64_ELEMENTS:
      case FLOAT32_ELEMENTS:
      case FLOAT64_ELEMENTS:
      case FAST_ELEMENTS:
      case FAST_SMI_ELEMENTS:
      case FAST_DOUBLE_ELEMENTS:
      case FAST_HOLEY_ELEMENTS:
      case FAST_HOLEY_SMI_ELEMENTS:
      case FAST_HOLEY_DOUBLE_ELEMENTS:
      case DICTIONARY_ELEMENTS:
      case SLOPPY_ARGUMENTS_ELEMENTS:
        UNREACHABLE();
        break;
    }
  }
}
 
 
void LCodeGen::DoStoreKeyedFixedDoubleArray(LStoreKeyed* instr) {
  XMMRegister value = ToDoubleRegister(instr->value());
  LOperand* key = instr->key();
  if (kPointerSize == kInt32Size && !key->IsConstantOperand() &&
      instr->hydrogen()->IsDehoisted()) {
    // Sign extend key because it could be a 32 bit negative value
    // and the dehoisted address computation happens in 64 bits
    __ movsxlq(ToRegister(key), ToRegister(key));
  }
  if (instr->NeedsCanonicalization()) {
    Label have_value;
 
    __ ucomisd(value, value);
    __ j(parity_odd, &have_value, Label::kNear);  // NaN.
 
    __ Set(kScratchRegister,
           bit_cast<uint64_t>(
               FixedDoubleArray::canonical_not_the_hole_nan_as_double()));
    __ movq(value, kScratchRegister);
 
    __ bind(&have_value);
  }
 
  Operand double_store_operand = BuildFastArrayOperand(
      instr->elements(),
      key,
      instr->hydrogen()->key()->representation(),
      FAST_DOUBLE_ELEMENTS,
      instr->base_offset());
 
  __ movsd(double_store_operand, value);
}
 
 
void LCodeGen::DoStoreKeyedFixedArray(LStoreKeyed* instr) {
  HStoreKeyed* hinstr = instr->hydrogen();
  LOperand* key = instr->key();
  int offset = instr->base_offset();
  Representation representation = hinstr->value()->representation();
 
  if (kPointerSize == kInt32Size && !key->IsConstantOperand() &&
      instr->hydrogen()->IsDehoisted()) {
    // Sign extend key because it could be a 32 bit negative value
    // and the dehoisted address computation happens in 64 bits
    __ movsxlq(ToRegister(key), ToRegister(key));
  }
  if (representation.IsInteger32() && SmiValuesAre32Bits()) {
    DCHECK(hinstr->store_mode() == STORE_TO_INITIALIZED_ENTRY);
    DCHECK(hinstr->elements_kind() == FAST_SMI_ELEMENTS);
    if (FLAG_debug_code) {
      Register scratch = kScratchRegister;
      __ Load(scratch,
              BuildFastArrayOperand(instr->elements(),
                                    key,
                                    instr->hydrogen()->key()->representation(),
                                    FAST_ELEMENTS,
                                    offset),
              Representation::Smi());
      __ AssertSmi(scratch);
    }
    // Store int value directly to upper half of the smi.
    STATIC_ASSERT(kSmiTag == 0);
    DCHECK(kSmiTagSize + kSmiShiftSize == 32);
    offset += kPointerSize / 2;
  }
 
  Operand operand =
      BuildFastArrayOperand(instr->elements(),
                            key,
                            instr->hydrogen()->key()->representation(),
                            FAST_ELEMENTS,
                            offset);
  if (instr->value()->IsRegister()) {
    __ Store(operand, ToRegister(instr->value()), representation);
  } else {
    LConstantOperand* operand_value = LConstantOperand::cast(instr->value());
    if (IsInteger32Constant(operand_value)) {
      int32_t value = ToInteger32(operand_value);
      if (representation.IsSmi()) {
        __ Move(operand, Smi::FromInt(value));
 
      } else {
        __ movl(operand, Immediate(value));
      }
    } else {
      Handle<Object> handle_value = ToHandle(operand_value);
      __ Move(operand, handle_value);
    }
  }
 
  if (hinstr->NeedsWriteBarrier()) {
    Register elements = ToRegister(instr->elements());
    DCHECK(instr->value()->IsRegister());
    Register value = ToRegister(instr->value());
    DCHECK(!key->IsConstantOperand());
    SmiCheck check_needed = hinstr->value()->type().IsHeapObject()
            ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
    // Compute address of modified element and store it into key register.
    Register key_reg(ToRegister(key));
    __ leap(key_reg, operand);
    __ RecordWrite(elements,
                   key_reg,
                   value,
                   kSaveFPRegs,
                   EMIT_REMEMBERED_SET,
                   check_needed,
                   hinstr->PointersToHereCheckForValue());
  }
}
 
 
void LCodeGen::DoStoreKeyed(LStoreKeyed* instr) {
  if (instr->is_typed_elements()) {
    DoStoreKeyedExternalArray(instr);
  } else if (instr->hydrogen()->value()->representation().IsDouble()) {
    DoStoreKeyedFixedDoubleArray(instr);
  } else {
    DoStoreKeyedFixedArray(instr);
  }
}
 
 
void LCodeGen::DoStoreKeyedGeneric(LStoreKeyedGeneric* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  DCHECK(ToRegister(instr->object()).is(StoreDescriptor::ReceiverRegister()));
  DCHECK(ToRegister(instr->key()).is(StoreDescriptor::NameRegister()));
  DCHECK(ToRegister(instr->value()).is(StoreDescriptor::ValueRegister()));
 
  Handle<Code> ic =
      CodeFactory::KeyedStoreIC(isolate(), instr->strict_mode()).code();
  CallCode(ic, RelocInfo::CODE_TARGET, instr);
}
 
 
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;
  __ Cmp(FieldOperand(object_reg, HeapObject::kMapOffset), from_map);
  __ j(not_equal, &not_applicable);
  if (IsSimpleMapChangeTransition(from_kind, to_kind)) {
    Register new_map_reg = ToRegister(instr->new_map_temp());
    __ Move(new_map_reg, to_map, RelocInfo::EMBEDDED_OBJECT);
    __ movp(FieldOperand(object_reg, HeapObject::kMapOffset), new_map_reg);
    // Write barrier.
    __ RecordWriteForMap(object_reg, new_map_reg, ToRegister(instr->temp()),
                         kDontSaveFPRegs);
  } else {
    DCHECK(object_reg.is(rax));
    DCHECK(ToRegister(instr->context()).is(rsi));
    PushSafepointRegistersScope scope(this);
    __ Move(rbx, to_map);
    bool is_js_array = from_map->instance_type() == JS_ARRAY_TYPE;
    TransitionElementsKindStub stub(isolate(), from_kind, to_kind, is_js_array);
    __ CallStub(&stub);
    RecordSafepointWithLazyDeopt(instr, RECORD_SAFEPOINT_WITH_REGISTERS, 0);
  }
  __ bind(&not_applicable);
}
 
 
void LCodeGen::DoTrapAllocationMemento(LTrapAllocationMemento* instr) {
  Register object = ToRegister(instr->object());
  Register temp = ToRegister(instr->temp());
  Label no_memento_found;
  __ TestJSArrayForAllocationMemento(object, temp, &no_memento_found);
  DeoptimizeIf(equal, instr, "memento found");
  __ bind(&no_memento_found);
}
 
 
void LCodeGen::DoStringAdd(LStringAdd* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  DCHECK(ToRegister(instr->left()).is(rdx));
  DCHECK(ToRegister(instr->right()).is(rax));
  StringAddStub stub(isolate(),
                     instr->hydrogen()->flags(),
                     instr->hydrogen()->pretenure_flag());
  CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
}
 
 
void LCodeGen::DoStringCharCodeAt(LStringCharCodeAt* instr) {
  class DeferredStringCharCodeAt FINAL : public LDeferredCode {
   public:
    DeferredStringCharCodeAt(LCodeGen* codegen, LStringCharCodeAt* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() OVERRIDE {
      codegen()->DoDeferredStringCharCodeAt(instr_);
    }
    virtual LInstruction* instr() OVERRIDE { return instr_; }
   private:
    LStringCharCodeAt* instr_;
  };
 
  DeferredStringCharCodeAt* deferred =
      new(zone()) DeferredStringCharCodeAt(this, instr);
 
  StringCharLoadGenerator::Generate(masm(),
                                    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, 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()) {
    int32_t const_index = ToInteger32(LConstantOperand::cast(instr->index()));
    __ Push(Smi::FromInt(const_index));
  } else {
    Register index = ToRegister(instr->index());
    __ Integer32ToSmi(index, index);
    __ Push(index);
  }
  CallRuntimeFromDeferred(
      Runtime::kStringCharCodeAtRT, 2, instr, instr->context());
  __ AssertSmi(rax);
  __ SmiToInteger32(rax, rax);
  __ StoreToSafepointRegisterSlot(result, rax);
}
 
 
void LCodeGen::DoStringCharFromCode(LStringCharFromCode* instr) {
  class DeferredStringCharFromCode FINAL : public LDeferredCode {
   public:
    DeferredStringCharFromCode(LCodeGen* codegen, LStringCharFromCode* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() OVERRIDE {
      codegen()->DoDeferredStringCharFromCode(instr_);
    }
    virtual LInstruction* instr() OVERRIDE { return instr_; }
   private:
    LStringCharFromCode* instr_;
  };
 
  DeferredStringCharFromCode* deferred =
      new(zone()) DeferredStringCharFromCode(this, instr);
 
  DCHECK(instr->hydrogen()->value()->representation().IsInteger32());
  Register char_code = ToRegister(instr->char_code());
  Register result = ToRegister(instr->result());
  DCHECK(!char_code.is(result));
 
  __ cmpl(char_code, Immediate(String::kMaxOneByteCharCode));
  __ j(above, deferred->entry());
  __ movsxlq(char_code, char_code);
  __ LoadRoot(result, Heap::kSingleCharacterStringCacheRootIndex);
  __ movp(result, FieldOperand(result,
                               char_code, times_pointer_size,
                               FixedArray::kHeaderSize));
  __ CompareRoot(result, Heap::kUndefinedValueRootIndex);
  __ 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, 0);
 
  PushSafepointRegistersScope scope(this);
  __ Integer32ToSmi(char_code, char_code);
  __ Push(char_code);
  CallRuntimeFromDeferred(Runtime::kCharFromCode, 1, instr, instr->context());
  __ StoreToSafepointRegisterSlot(result, rax);
}
 
 
void LCodeGen::DoInteger32ToDouble(LInteger32ToDouble* instr) {
  LOperand* input = instr->value();
  DCHECK(input->IsRegister() || input->IsStackSlot());
  LOperand* output = instr->result();
  DCHECK(output->IsDoubleRegister());
  if (input->IsRegister()) {
    __ Cvtlsi2sd(ToDoubleRegister(output), ToRegister(input));
  } else {
    __ Cvtlsi2sd(ToDoubleRegister(output), ToOperand(input));
  }
}
 
 
void LCodeGen::DoUint32ToDouble(LUint32ToDouble* instr) {
  LOperand* input = instr->value();
  LOperand* output = instr->result();
 
  __ LoadUint32(ToDoubleRegister(output), ToRegister(input));
}
 
 
void LCodeGen::DoNumberTagI(LNumberTagI* instr) {
  class DeferredNumberTagI FINAL : public LDeferredCode {
   public:
    DeferredNumberTagI(LCodeGen* codegen, LNumberTagI* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() OVERRIDE {
      codegen()->DoDeferredNumberTagIU(instr_, instr_->value(), instr_->temp1(),
                                       instr_->temp2(), SIGNED_INT32);
    }
    virtual LInstruction* instr() OVERRIDE { return instr_; }
   private:
    LNumberTagI* instr_;
  };
 
  LOperand* input = instr->value();
  DCHECK(input->IsRegister() && input->Equals(instr->result()));
  Register reg = ToRegister(input);
 
  if (SmiValuesAre32Bits()) {
    __ Integer32ToSmi(reg, reg);
  } else {
    DCHECK(SmiValuesAre31Bits());
    DeferredNumberTagI* deferred = new(zone()) DeferredNumberTagI(this, instr);
    __ Integer32ToSmi(reg, reg);
    __ j(overflow, deferred->entry());
    __ bind(deferred->exit());
  }
}
 
 
void LCodeGen::DoNumberTagU(LNumberTagU* instr) {
  class DeferredNumberTagU FINAL : public LDeferredCode {
   public:
    DeferredNumberTagU(LCodeGen* codegen, LNumberTagU* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() OVERRIDE {
      codegen()->DoDeferredNumberTagIU(instr_, instr_->value(), instr_->temp1(),
                                       instr_->temp2(), UNSIGNED_INT32);
    }
    virtual LInstruction* instr() OVERRIDE { return instr_; }
   private:
    LNumberTagU* instr_;
  };
 
  LOperand* input = instr->value();
  DCHECK(input->IsRegister() && input->Equals(instr->result()));
  Register reg = ToRegister(input);
 
  DeferredNumberTagU* deferred = new(zone()) DeferredNumberTagU(this, instr);
  __ cmpl(reg, Immediate(Smi::kMaxValue));
  __ j(above, deferred->entry());
  __ Integer32ToSmi(reg, reg);
  __ bind(deferred->exit());
}
 
 
void LCodeGen::DoDeferredNumberTagIU(LInstruction* instr,
                                     LOperand* value,
                                     LOperand* temp1,
                                     LOperand* temp2,
                                     IntegerSignedness signedness) {
  Label done, slow;
  Register reg = ToRegister(value);
  Register tmp = ToRegister(temp1);
  XMMRegister temp_xmm = ToDoubleRegister(temp2);
 
  // Load value into temp_xmm which will be preserved across potential call to
  // runtime (MacroAssembler::EnterExitFrameEpilogue preserves only allocatable
  // XMM registers on x64).
  if (signedness == SIGNED_INT32) {
    DCHECK(SmiValuesAre31Bits());
    // 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.
    __ SmiToInteger32(reg, reg);
    __ xorl(reg, Immediate(0x80000000));
    __ cvtlsi2sd(temp_xmm, reg);
  } else {
    DCHECK(signedness == UNSIGNED_INT32);
    __ LoadUint32(temp_xmm, reg);
  }
 
  if (FLAG_inline_new) {
    __ AllocateHeapNumber(reg, tmp, &slow);
    __ jmp(&done, kPointerSize == kInt64Size ? Label::kNear : Label::kFar);
  }
 
  // Slow case: Call the runtime system to do the number allocation.
  __ bind(&slow);
  {
    // 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.
    __ Set(reg, 0);
 
    // Preserve the value of all registers.
    PushSafepointRegistersScope scope(this);
 
    // NumberTagIU uses 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.
    __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
    __ CallRuntimeSaveDoubles(Runtime::kAllocateHeapNumber);
    RecordSafepointWithRegisters(
        instr->pointer_map(), 0, Safepoint::kNoLazyDeopt);
    __ StoreToSafepointRegisterSlot(reg, rax);
  }
 
  // Done. Put the value in temp_xmm into the value of the allocated heap
  // number.
  __ bind(&done);
  __ movsd(FieldOperand(reg, HeapNumber::kValueOffset), temp_xmm);
}
 
 
void LCodeGen::DoNumberTagD(LNumberTagD* instr) {
  class DeferredNumberTagD FINAL : public LDeferredCode {
   public:
    DeferredNumberTagD(LCodeGen* codegen, LNumberTagD* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() OVERRIDE {
      codegen()->DoDeferredNumberTagD(instr_);
    }
    virtual LInstruction* instr() OVERRIDE { return instr_; }
   private:
    LNumberTagD* instr_;
  };
 
  XMMRegister input_reg = ToDoubleRegister(instr->value());
  Register reg = ToRegister(instr->result());
  Register tmp = ToRegister(instr->temp());
 
  DeferredNumberTagD* deferred = new(zone()) DeferredNumberTagD(this, instr);
  if (FLAG_inline_new) {
    __ AllocateHeapNumber(reg, tmp, deferred->entry());
  } else {
    __ jmp(deferred->entry());
  }
  __ bind(deferred->exit());
  __ movsd(FieldOperand(reg, HeapNumber::kValueOffset), input_reg);
}
 
 
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());
  __ Move(reg, Smi::FromInt(0));
 
  {
    PushSafepointRegistersScope scope(this);
    // NumberTagD uses 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.
    __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
    __ CallRuntimeSaveDoubles(Runtime::kAllocateHeapNumber);
    RecordSafepointWithRegisters(
        instr->pointer_map(), 0, Safepoint::kNoLazyDeopt);
    __ movp(kScratchRegister, rax);
  }
  __ movp(reg, kScratchRegister);
}
 
 
void LCodeGen::DoSmiTag(LSmiTag* instr) {
  HChange* hchange = instr->hydrogen();
  Register input = ToRegister(instr->value());
  Register output = ToRegister(instr->result());
  if (hchange->CheckFlag(HValue::kCanOverflow) &&
      hchange->value()->CheckFlag(HValue::kUint32)) {
    Condition is_smi = __ CheckUInteger32ValidSmiValue(input);
    DeoptimizeIf(NegateCondition(is_smi), instr, "overflow");
  }
  __ Integer32ToSmi(output, input);
  if (hchange->CheckFlag(HValue::kCanOverflow) &&
      !hchange->value()->CheckFlag(HValue::kUint32)) {
    DeoptimizeIf(overflow, instr, "overflow");
  }
}
 
 
void LCodeGen::DoSmiUntag(LSmiUntag* instr) {
  DCHECK(instr->value()->Equals(instr->result()));
  Register input = ToRegister(instr->value());
  if (instr->needs_check()) {
    Condition is_smi = __ CheckSmi(input);
    DeoptimizeIf(NegateCondition(is_smi), instr, "not a Smi");
  } else {
    __ AssertSmi(input);
  }
  __ SmiToInteger32(input, input);
}
 
 
void LCodeGen::EmitNumberUntagD(LNumberUntagD* instr, Register input_reg,
                                XMMRegister result_reg, NumberUntagDMode mode) {
  bool can_convert_undefined_to_nan =
      instr->hydrogen()->can_convert_undefined_to_nan();
  bool deoptimize_on_minus_zero = instr->hydrogen()->deoptimize_on_minus_zero();
 
  Label convert, load_smi, done;
 
  if (mode == NUMBER_CANDIDATE_IS_ANY_TAGGED) {
    // Smi check.
    __ JumpIfSmi(input_reg, &load_smi, Label::kNear);
 
    // Heap number map check.
    __ CompareRoot(FieldOperand(input_reg, HeapObject::kMapOffset),
                   Heap::kHeapNumberMapRootIndex);
 
    // On x64 it is safe to load at heap number offset before evaluating the map
    // check, since all heap objects are at least two words long.
    __ movsd(result_reg, FieldOperand(input_reg, HeapNumber::kValueOffset));
 
    if (can_convert_undefined_to_nan) {
      __ j(not_equal, &convert, Label::kNear);
    } else {
      DeoptimizeIf(not_equal, instr, "not a heap number");
    }
 
    if (deoptimize_on_minus_zero) {
      XMMRegister xmm_scratch = double_scratch0();
      __ xorps(xmm_scratch, xmm_scratch);
      __ ucomisd(xmm_scratch, result_reg);
      __ j(not_equal, &done, Label::kNear);
      __ movmskpd(kScratchRegister, result_reg);
      __ testq(kScratchRegister, Immediate(1));
      DeoptimizeIf(not_zero, instr, "minus zero");
    }
    __ jmp(&done, Label::kNear);
 
    if (can_convert_undefined_to_nan) {
      __ bind(&convert);
 
      // Convert undefined (and hole) to NaN. Compute NaN as 0/0.
      __ CompareRoot(input_reg, Heap::kUndefinedValueRootIndex);
      DeoptimizeIf(not_equal, instr, "not a heap number/undefined");
 
      __ xorps(result_reg, result_reg);
      __ divsd(result_reg, result_reg);
      __ jmp(&done, Label::kNear);
    }
  } else {
    DCHECK(mode == NUMBER_CANDIDATE_IS_SMI);
  }
 
  // Smi to XMM conversion
  __ bind(&load_smi);
  __ SmiToInteger32(kScratchRegister, input_reg);
  __ Cvtlsi2sd(result_reg, kScratchRegister);
  __ bind(&done);
}
 
 
void LCodeGen::DoDeferredTaggedToI(LTaggedToI* instr, Label* done) {
  Register input_reg = ToRegister(instr->value());
 
  if (instr->truncating()) {
    Label no_heap_number, check_bools, check_false;
 
    // Heap number map check.
    __ CompareRoot(FieldOperand(input_reg, HeapObject::kMapOffset),
                   Heap::kHeapNumberMapRootIndex);
    __ j(not_equal, &no_heap_number, Label::kNear);
    __ TruncateHeapNumberToI(input_reg, input_reg);
    __ jmp(done);
 
    __ bind(&no_heap_number);
    // Check for Oddballs. Undefined/False is converted to zero and True to one
    // for truncating conversions.
    __ CompareRoot(input_reg, Heap::kUndefinedValueRootIndex);
    __ j(not_equal, &check_bools, Label::kNear);
    __ Set(input_reg, 0);
    __ jmp(done);
 
    __ bind(&check_bools);
    __ CompareRoot(input_reg, Heap::kTrueValueRootIndex);
    __ j(not_equal, &check_false, Label::kNear);
    __ Set(input_reg, 1);
    __ jmp(done);
 
    __ bind(&check_false);
    __ CompareRoot(input_reg, Heap::kFalseValueRootIndex);
    DeoptimizeIf(not_equal, instr, "not a heap number/undefined/true/false");
    __ Set(input_reg, 0);
  } else {
    XMMRegister scratch = ToDoubleRegister(instr->temp());
    DCHECK(!scratch.is(xmm0));
    __ CompareRoot(FieldOperand(input_reg, HeapObject::kMapOffset),
                   Heap::kHeapNumberMapRootIndex);
    DeoptimizeIf(not_equal, instr, "not a heap number");
    __ movsd(xmm0, FieldOperand(input_reg, HeapNumber::kValueOffset));
    __ cvttsd2si(input_reg, xmm0);
    __ Cvtlsi2sd(scratch, input_reg);
    __ ucomisd(xmm0, scratch);
    DeoptimizeIf(not_equal, instr, "lost precision");
    DeoptimizeIf(parity_even, instr, "NaN");
    if (instr->hydrogen()->GetMinusZeroMode() == FAIL_ON_MINUS_ZERO) {
      __ testl(input_reg, input_reg);
      __ j(not_zero, done);
      __ movmskpd(input_reg, xmm0);
      __ andl(input_reg, Immediate(1));
      DeoptimizeIf(not_zero, instr, "minus zero");
    }
  }
}
 
 
void LCodeGen::DoTaggedToI(LTaggedToI* instr) {
  class DeferredTaggedToI FINAL : public LDeferredCode {
   public:
    DeferredTaggedToI(LCodeGen* codegen, LTaggedToI* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() OVERRIDE {
      codegen()->DoDeferredTaggedToI(instr_, done());
    }
    virtual LInstruction* instr() OVERRIDE { return instr_; }
   private:
    LTaggedToI* instr_;
  };
 
  LOperand* input = instr->value();
  DCHECK(input->IsRegister());
  DCHECK(input->Equals(instr->result()));
  Register input_reg = ToRegister(input);
 
  if (instr->hydrogen()->value()->representation().IsSmi()) {
    __ SmiToInteger32(input_reg, input_reg);
  } else {
    DeferredTaggedToI* deferred = new(zone()) DeferredTaggedToI(this, instr);
    __ JumpIfNotSmi(input_reg, deferred->entry());
    __ SmiToInteger32(input_reg, input_reg);
    __ bind(deferred->exit());
  }
}
 
 
void LCodeGen::DoNumberUntagD(LNumberUntagD* instr) {
  LOperand* input = instr->value();
  DCHECK(input->IsRegister());
  LOperand* result = instr->result();
  DCHECK(result->IsDoubleRegister());
 
  Register input_reg = ToRegister(input);
  XMMRegister result_reg = ToDoubleRegister(result);
 
  HValue* value = instr->hydrogen()->value();
  NumberUntagDMode mode = value->representation().IsSmi()
      ? NUMBER_CANDIDATE_IS_SMI : NUMBER_CANDIDATE_IS_ANY_TAGGED;
 
  EmitNumberUntagD(instr, input_reg, result_reg, mode);
}
 
 
void LCodeGen::DoDoubleToI(LDoubleToI* instr) {
  LOperand* input = instr->value();
  DCHECK(input->IsDoubleRegister());
  LOperand* result = instr->result();
  DCHECK(result->IsRegister());
 
  XMMRegister input_reg = ToDoubleRegister(input);
  Register result_reg = ToRegister(result);
 
  if (instr->truncating()) {
    __ TruncateDoubleToI(result_reg, input_reg);
  } else {
    Label lost_precision, is_nan, minus_zero, done;
    XMMRegister xmm_scratch = double_scratch0();
    Label::Distance dist = DeoptEveryNTimes() ? Label::kFar : Label::kNear;
    __ DoubleToI(result_reg, input_reg, xmm_scratch,
                 instr->hydrogen()->GetMinusZeroMode(), &lost_precision,
                 &is_nan, &minus_zero, dist);
    __ jmp(&done, dist);
    __ bind(&lost_precision);
    DeoptimizeIf(no_condition, instr, "lost precision");
    __ bind(&is_nan);
    DeoptimizeIf(no_condition, instr, "NaN");
    __ bind(&minus_zero);
    DeoptimizeIf(no_condition, instr, "minus zero");
    __ bind(&done);
  }
}
 
 
void LCodeGen::DoDoubleToSmi(LDoubleToSmi* instr) {
  LOperand* input = instr->value();
  DCHECK(input->IsDoubleRegister());
  LOperand* result = instr->result();
  DCHECK(result->IsRegister());
 
  XMMRegister input_reg = ToDoubleRegister(input);
  Register result_reg = ToRegister(result);
 
  Label lost_precision, is_nan, minus_zero, done;
  XMMRegister xmm_scratch = double_scratch0();
  Label::Distance dist = DeoptEveryNTimes() ? Label::kFar : Label::kNear;
  __ DoubleToI(result_reg, input_reg, xmm_scratch,
               instr->hydrogen()->GetMinusZeroMode(), &lost_precision, &is_nan,
               &minus_zero, dist);
  __ jmp(&done, dist);
  __ bind(&lost_precision);
  DeoptimizeIf(no_condition, instr, "lost precision");
  __ bind(&is_nan);
  DeoptimizeIf(no_condition, instr, "NaN");
  __ bind(&minus_zero);
  DeoptimizeIf(no_condition, instr, "minus zero");
  __ bind(&done);
  __ Integer32ToSmi(result_reg, result_reg);
  DeoptimizeIf(overflow, instr, "overflow");
}
 
 
void LCodeGen::DoCheckSmi(LCheckSmi* instr) {
  LOperand* input = instr->value();
  Condition cc = masm()->CheckSmi(ToRegister(input));
  DeoptimizeIf(NegateCondition(cc), instr, "not a Smi");
}
 
 
void LCodeGen::DoCheckNonSmi(LCheckNonSmi* instr) {
  if (!instr->hydrogen()->value()->type().IsHeapObject()) {
    LOperand* input = instr->value();
    Condition cc = masm()->CheckSmi(ToRegister(input));
    DeoptimizeIf(cc, instr, "Smi");
  }
}
 
 
void LCodeGen::DoCheckInstanceType(LCheckInstanceType* instr) {
  Register input = ToRegister(instr->value());
 
  __ movp(kScratchRegister, FieldOperand(input, HeapObject::kMapOffset));
 
  if (instr->hydrogen()->is_interval_check()) {
    InstanceType first;
    InstanceType last;
    instr->hydrogen()->GetCheckInterval(&first, &last);
 
    __ cmpb(FieldOperand(kScratchRegister, Map::kInstanceTypeOffset),
            Immediate(static_cast<int8_t>(first)));
 
    // If there is only one type in the interval check for equality.
    if (first == last) {
      DeoptimizeIf(not_equal, instr, "wrong instance type");
    } else {
      DeoptimizeIf(below, instr, "wrong instance type");
      // Omit check for the last type.
      if (last != LAST_TYPE) {
        __ cmpb(FieldOperand(kScratchRegister, Map::kInstanceTypeOffset),
                Immediate(static_cast<int8_t>(last)));
        DeoptimizeIf(above, instr, "wrong instance type");
      }
    }
  } else {
    uint8_t mask;
    uint8_t tag;
    instr->hydrogen()->GetCheckMaskAndTag(&mask, &tag);
 
    if (base::bits::IsPowerOfTwo32(mask)) {
      DCHECK(tag == 0 || base::bits::IsPowerOfTwo32(tag));
      __ testb(FieldOperand(kScratchRegister, Map::kInstanceTypeOffset),
               Immediate(mask));
      DeoptimizeIf(tag == 0 ? not_zero : zero, instr, "wrong instance type");
    } else {
      __ movzxbl(kScratchRegister,
                 FieldOperand(kScratchRegister, Map::kInstanceTypeOffset));
      __ andb(kScratchRegister, Immediate(mask));
      __ cmpb(kScratchRegister, Immediate(tag));
      DeoptimizeIf(not_equal, instr, "wrong instance type");
    }
  }
}
 
 
void LCodeGen::DoCheckValue(LCheckValue* instr) {
  Register reg = ToRegister(instr->value());
  __ Cmp(reg, instr->hydrogen()->object().handle());
  DeoptimizeIf(not_equal, instr, "value mismatch");
}
 
 
void LCodeGen::DoDeferredInstanceMigration(LCheckMaps* instr, Register object) {
  {
    PushSafepointRegistersScope scope(this);
    __ Push(object);
    __ Set(rsi, 0);
    __ CallRuntimeSaveDoubles(Runtime::kTryMigrateInstance);
    RecordSafepointWithRegisters(
        instr->pointer_map(), 1, Safepoint::kNoLazyDeopt);
 
    __ testp(rax, Immediate(kSmiTagMask));
  }
  DeoptimizeIf(zero, instr, "instance migration failed");
}
 
 
void LCodeGen::DoCheckMaps(LCheckMaps* instr) {
  class DeferredCheckMaps FINAL : public LDeferredCode {
   public:
    DeferredCheckMaps(LCodeGen* codegen, LCheckMaps* instr, Register object)
        : LDeferredCode(codegen), instr_(instr), object_(object) {
      SetExit(check_maps());
    }
    virtual void Generate() OVERRIDE {
      codegen()->DoDeferredInstanceMigration(instr_, object_);
    }
    Label* check_maps() { return &check_maps_; }
    virtual LInstruction* instr() OVERRIDE { return instr_; }
   private:
    LCheckMaps* instr_;
    Label check_maps_;
    Register object_;
  };
 
  if (instr->hydrogen()->IsStabilityCheck()) {
    const UniqueSet<Map>* maps = instr->hydrogen()->maps();
    for (int i = 0; i < maps->size(); ++i) {
      AddStabilityDependency(maps->at(i).handle());
    }
    return;
  }
 
  LOperand* input = instr->value();
  DCHECK(input->IsRegister());
  Register reg = ToRegister(input);
 
  DeferredCheckMaps* deferred = NULL;
  if (instr->hydrogen()->HasMigrationTarget()) {
    deferred = new(zone()) DeferredCheckMaps(this, instr, reg);
    __ bind(deferred->check_maps());
  }
 
  const UniqueSet<Map>* maps = instr->hydrogen()->maps();
  Label success;
  for (int i = 0; i < maps->size() - 1; i++) {
    Handle<Map> map = maps->at(i).handle();
    __ CompareMap(reg, map);
    __ j(equal, &success, Label::kNear);
  }
 
  Handle<Map> map = maps->at(maps->size() - 1).handle();
  __ CompareMap(reg, map);
  if (instr->hydrogen()->HasMigrationTarget()) {
    __ j(not_equal, deferred->entry());
  } else {
    DeoptimizeIf(not_equal, instr, "wrong map");
  }
 
  __ bind(&success);
}
 
 
void LCodeGen::DoClampDToUint8(LClampDToUint8* instr) {
  XMMRegister value_reg = ToDoubleRegister(instr->unclamped());
  XMMRegister xmm_scratch = double_scratch0();
  Register result_reg = ToRegister(instr->result());
  __ ClampDoubleToUint8(value_reg, xmm_scratch, result_reg);
}
 
 
void LCodeGen::DoClampIToUint8(LClampIToUint8* instr) {
  DCHECK(instr->unclamped()->Equals(instr->result()));
  Register value_reg = ToRegister(instr->result());
  __ ClampUint8(value_reg);
}
 
 
void LCodeGen::DoClampTToUint8(LClampTToUint8* instr) {
  DCHECK(instr->unclamped()->Equals(instr->result()));
  Register input_reg = ToRegister(instr->unclamped());
  XMMRegister temp_xmm_reg = ToDoubleRegister(instr->temp_xmm());
  XMMRegister xmm_scratch = double_scratch0();
  Label is_smi, done, heap_number;
  Label::Distance dist = DeoptEveryNTimes() ? Label::kFar : Label::kNear;
  __ JumpIfSmi(input_reg, &is_smi, dist);
 
  // 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, "not a heap number/undefined");
  __ xorl(input_reg, input_reg);
  __ jmp(&done, Label::kNear);
 
  // Heap number
  __ bind(&heap_number);
  __ movsd(xmm_scratch, FieldOperand(input_reg, HeapNumber::kValueOffset));
  __ ClampDoubleToUint8(xmm_scratch, temp_xmm_reg, input_reg);
  __ jmp(&done, Label::kNear);
 
  // smi
  __ bind(&is_smi);
  __ SmiToInteger32(input_reg, input_reg);
  __ ClampUint8(input_reg);
 
  __ bind(&done);
}
 
 
void LCodeGen::DoDoubleBits(LDoubleBits* instr) {
  XMMRegister value_reg = ToDoubleRegister(instr->value());
  Register result_reg = ToRegister(instr->result());
  if (instr->hydrogen()->bits() == HDoubleBits::HIGH) {
    __ movq(result_reg, value_reg);
    __ shrq(result_reg, Immediate(32));
  } else {
    __ movd(result_reg, value_reg);
  }
}
 
 
void LCodeGen::DoConstructDouble(LConstructDouble* instr) {
  Register hi_reg = ToRegister(instr->hi());
  Register lo_reg = ToRegister(instr->lo());
  XMMRegister result_reg = ToDoubleRegister(instr->result());
  XMMRegister xmm_scratch = double_scratch0();
  __ movd(result_reg, hi_reg);
  __ psllq(result_reg, 32);
  __ movd(xmm_scratch, lo_reg);
  __ orps(result_reg, xmm_scratch);
}
 
 
void LCodeGen::DoAllocate(LAllocate* instr) {
  class DeferredAllocate FINAL : public LDeferredCode {
   public:
    DeferredAllocate(LCodeGen* codegen, LAllocate* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() OVERRIDE {
      codegen()->DoDeferredAllocate(instr_);
    }
    virtual LInstruction* instr() OVERRIDE { 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()->IsOldPointerSpaceAllocation()) {
    DCHECK(!instr->hydrogen()->IsOldDataSpaceAllocation());
    DCHECK(!instr->hydrogen()->IsNewSpaceAllocation());
    flags = static_cast<AllocationFlags>(flags | PRETENURE_OLD_POINTER_SPACE);
  } else if (instr->hydrogen()->IsOldDataSpaceAllocation()) {
    DCHECK(!instr->hydrogen()->IsNewSpaceAllocation());
    flags = static_cast<AllocationFlags>(flags | PRETENURE_OLD_DATA_SPACE);
  }
 
  if (instr->size()->IsConstantOperand()) {
    int32_t size = ToInteger32(LConstantOperand::cast(instr->size()));
    if (size <= Page::kMaxRegularHeapObjectSize) {
      __ Allocate(size, result, temp, no_reg, deferred->entry(), flags);
    } else {
      __ jmp(deferred->entry());
    }
  } else {
    Register size = ToRegister(instr->size());
    __ Allocate(size, result, temp, no_reg, deferred->entry(), flags);
  }
 
  __ bind(deferred->exit());
 
  if (instr->hydrogen()->MustPrefillWithFiller()) {
    if (instr->size()->IsConstantOperand()) {
      int32_t size = ToInteger32(LConstantOperand::cast(instr->size()));
      __ movl(temp, Immediate((size / kPointerSize) - 1));
    } else {
      temp = ToRegister(instr->size());
      __ sarp(temp, Immediate(kPointerSizeLog2));
      __ decl(temp);
    }
    Label loop;
    __ bind(&loop);
    __ Move(FieldOperand(result, temp, times_pointer_size, 0),
        isolate()->factory()->one_pointer_filler_map());
    __ decl(temp);
    __ j(not_zero, &loop);
  }
}
 
 
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.
  __ Move(result, Smi::FromInt(0));
 
  PushSafepointRegistersScope scope(this);
  if (instr->size()->IsRegister()) {
    Register size = ToRegister(instr->size());
    DCHECK(!size.is(result));
    __ Integer32ToSmi(size, size);
    __ Push(size);
  } else {
    int32_t size = ToInteger32(LConstantOperand::cast(instr->size()));
    __ Push(Smi::FromInt(size));
  }
 
  int flags = 0;
  if (instr->hydrogen()->IsOldPointerSpaceAllocation()) {
    DCHECK(!instr->hydrogen()->IsOldDataSpaceAllocation());
    DCHECK(!instr->hydrogen()->IsNewSpaceAllocation());
    flags = AllocateTargetSpace::update(flags, OLD_POINTER_SPACE);
  } else if (instr->hydrogen()->IsOldDataSpaceAllocation()) {
    DCHECK(!instr->hydrogen()->IsNewSpaceAllocation());
    flags = AllocateTargetSpace::update(flags, OLD_DATA_SPACE);
  } else {
    flags = AllocateTargetSpace::update(flags, NEW_SPACE);
  }
  __ Push(Smi::FromInt(flags));
 
  CallRuntimeFromDeferred(
      Runtime::kAllocateInTargetSpace, 2, instr, instr->context());
  __ StoreToSafepointRegisterSlot(result, rax);
}
 
 
void LCodeGen::DoToFastProperties(LToFastProperties* instr) {
  DCHECK(ToRegister(instr->value()).is(rax));
  __ Push(rax);
  CallRuntime(Runtime::kToFastProperties, 1, instr);
}
 
 
void LCodeGen::DoRegExpLiteral(LRegExpLiteral* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  Label materialized;
  // Registers will be used as follows:
  // rcx = literals array.
  // rbx = regexp literal.
  // rax = regexp literal clone.
  int literal_offset =
      FixedArray::OffsetOfElementAt(instr->hydrogen()->literal_index());
  __ Move(rcx, instr->hydrogen()->literals());
  __ movp(rbx, FieldOperand(rcx, literal_offset));
  __ CompareRoot(rbx, Heap::kUndefinedValueRootIndex);
  __ j(not_equal, &materialized, Label::kNear);
 
  // Create regexp literal using runtime function
  // Result will be in rax.
  __ Push(rcx);
  __ Push(Smi::FromInt(instr->hydrogen()->literal_index()));
  __ Push(instr->hydrogen()->pattern());
  __ Push(instr->hydrogen()->flags());
  CallRuntime(Runtime::kMaterializeRegExpLiteral, 4, instr);
  __ movp(rbx, rax);
 
  __ bind(&materialized);
  int size = JSRegExp::kSize + JSRegExp::kInObjectFieldCount * kPointerSize;
  Label allocated, runtime_allocate;
  __ Allocate(size, rax, rcx, rdx, &runtime_allocate, TAG_OBJECT);
  __ jmp(&allocated, Label::kNear);
 
  __ bind(&runtime_allocate);
  __ Push(rbx);
  __ Push(Smi::FromInt(size));
  CallRuntime(Runtime::kAllocateInNewSpace, 1, instr);
  __ Pop(rbx);
 
  __ 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) {
    __ movp(rdx, FieldOperand(rbx, i));
    __ movp(rcx, FieldOperand(rbx, i + kPointerSize));
    __ movp(FieldOperand(rax, i), rdx);
    __ movp(FieldOperand(rax, i + kPointerSize), rcx);
  }
  if ((size % (2 * kPointerSize)) != 0) {
    __ movp(rdx, FieldOperand(rbx, size - kPointerSize));
    __ movp(FieldOperand(rax, size - kPointerSize), rdx);
  }
}
 
 
void LCodeGen::DoFunctionLiteral(LFunctionLiteral* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  // 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(isolate(), instr->hydrogen()->strict_mode(),
                            instr->hydrogen()->kind());
    __ Move(rbx, instr->hydrogen()->shared_info());
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
  } else {
    __ Push(rsi);
    __ Push(instr->hydrogen()->shared_info());
    __ PushRoot(pretenure ? Heap::kTrueValueRootIndex :
                            Heap::kFalseValueRootIndex);
    CallRuntime(Runtime::kNewClosure, 3, instr);
  }
}
 
 
void LCodeGen::DoTypeof(LTypeof* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  LOperand* input = instr->value();
  EmitPushTaggedOperand(input);
  CallRuntime(Runtime::kTypeof, 1, instr);
}
 
 
void LCodeGen::EmitPushTaggedOperand(LOperand* operand) {
  DCHECK(!operand->IsDoubleRegister());
  if (operand->IsConstantOperand()) {
    __ Push(ToHandle(LConstantOperand::cast(operand)));
  } else if (operand->IsRegister()) {
    __ Push(ToRegister(operand));
  } else {
    __ Push(ToOperand(operand));
  }
}
 
 
void LCodeGen::DoTypeofIsAndBranch(LTypeofIsAndBranch* instr) {
  Register input = ToRegister(instr->value());
  Condition final_branch_condition = EmitTypeofIs(instr, input);
  if (final_branch_condition != no_condition) {
    EmitBranch(instr, final_branch_condition);
  }
}
 
 
Condition LCodeGen::EmitTypeofIs(LTypeofIsAndBranch* instr, Register input) {
  Label* true_label = instr->TrueLabel(chunk_);
  Label* false_label = instr->FalseLabel(chunk_);
  Handle<String> type_name = instr->type_literal();
  int left_block = instr->TrueDestination(chunk_);
  int right_block = instr->FalseDestination(chunk_);
  int next_block = GetNextEmittedBlock();
 
  Label::Distance true_distance = left_block == next_block ? Label::kNear
                                                           : Label::kFar;
  Label::Distance false_distance = right_block == next_block ? Label::kNear
                                                             : Label::kFar;
  Condition final_branch_condition = no_condition;
  Factory* factory = isolate()->factory();
  if (String::Equals(type_name, factory->number_string())) {
    __ JumpIfSmi(input, true_label, true_distance);
    __ CompareRoot(FieldOperand(input, HeapObject::kMapOffset),
                   Heap::kHeapNumberMapRootIndex);
 
    final_branch_condition = equal;
 
  } else if (String::Equals(type_name, factory->string_string())) {
    __ JumpIfSmi(input, false_label, false_distance);
    __ CmpObjectType(input, FIRST_NONSTRING_TYPE, input);
    __ j(above_equal, false_label, false_distance);
    __ testb(FieldOperand(input, Map::kBitFieldOffset),
             Immediate(1 << Map::kIsUndetectable));
    final_branch_condition = zero;
 
  } else if (String::Equals(type_name, factory->symbol_string())) {
    __ JumpIfSmi(input, false_label, false_distance);
    __ CmpObjectType(input, SYMBOL_TYPE, input);
    final_branch_condition = equal;
 
  } else if (String::Equals(type_name, factory->boolean_string())) {
    __ CompareRoot(input, Heap::kTrueValueRootIndex);
    __ j(equal, true_label, true_distance);
    __ CompareRoot(input, Heap::kFalseValueRootIndex);
    final_branch_condition = equal;
 
  } else if (String::Equals(type_name, factory->undefined_string())) {
    __ CompareRoot(input, Heap::kUndefinedValueRootIndex);
    __ j(equal, true_label, true_distance);
    __ JumpIfSmi(input, false_label, false_distance);
    // Check for undetectable objects => true.
    __ movp(input, FieldOperand(input, HeapObject::kMapOffset));
    __ testb(FieldOperand(input, Map::kBitFieldOffset),
             Immediate(1 << Map::kIsUndetectable));
    final_branch_condition = not_zero;
 
  } else if (String::Equals(type_name, factory->function_string())) {
    STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
    __ JumpIfSmi(input, false_label, false_distance);
    __ CmpObjectType(input, JS_FUNCTION_TYPE, input);
    __ j(equal, true_label, true_distance);
    __ CmpInstanceType(input, JS_FUNCTION_PROXY_TYPE);
    final_branch_condition = equal;
 
  } else if (String::Equals(type_name, factory->object_string())) {
    __ JumpIfSmi(input, false_label, false_distance);
    __ CompareRoot(input, Heap::kNullValueRootIndex);
    __ j(equal, true_label, true_distance);
    __ CmpObjectType(input, FIRST_NONCALLABLE_SPEC_OBJECT_TYPE, input);
    __ j(below, false_label, false_distance);
    __ CmpInstanceType(input, LAST_NONCALLABLE_SPEC_OBJECT_TYPE);
    __ j(above, false_label, false_distance);
    // Check for undetectable objects => false.
    __ testb(FieldOperand(input, Map::kBitFieldOffset),
             Immediate(1 << Map::kIsUndetectable));
    final_branch_condition = zero;
 
  } else {
    __ jmp(false_label, false_distance);
  }
 
  return final_branch_condition;
}
 
 
void LCodeGen::DoIsConstructCallAndBranch(LIsConstructCallAndBranch* instr) {
  Register temp = ToRegister(instr->temp());
 
  EmitIsConstructCall(temp);
  EmitBranch(instr, equal);
}
 
 
void LCodeGen::EmitIsConstructCall(Register temp) {
  // Get the frame pointer for the calling frame.
  __ movp(temp, Operand(rbp, StandardFrameConstants::kCallerFPOffset));
 
  // Skip the arguments adaptor frame if it exists.
  Label check_frame_marker;
  __ Cmp(Operand(temp, StandardFrameConstants::kContextOffset),
         Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
  __ j(not_equal, &check_frame_marker, Label::kNear);
  __ movp(temp, Operand(temp, StandardFrameConstants::kCallerFPOffset));
 
  // Check the marker in the calling frame.
  __ bind(&check_frame_marker);
  __ Cmp(Operand(temp, StandardFrameConstants::kMarkerOffset),
         Smi::FromInt(StackFrame::CONSTRUCT));
}
 
 
void LCodeGen::EnsureSpaceForLazyDeopt(int space_needed) {
  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();
    if (current_pc < last_lazy_deopt_pc_ + space_needed) {
      int padding_size = last_lazy_deopt_pc_ + space_needed - current_pc;
      __ Nop(padding_size);
    }
  }
  last_lazy_deopt_pc_ = masm()->pc_offset();
}
 
 
void LCodeGen::DoLazyBailout(LLazyBailout* instr) {
  last_lazy_deopt_pc_ = masm()->pc_offset();
  DCHECK(instr->HasEnvironment());
  LEnvironment* env = instr->environment();
  RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
  safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
}
 
 
void LCodeGen::DoDeoptimize(LDeoptimize* instr) {
  Deoptimizer::BailoutType type = instr->hydrogen()->type();
  // TODO(danno): Stubs expect all deopts to be lazy for historical reasons (the
  // needed return address), even though the implementation of LAZY and EAGER is
  // now identical. When LAZY is eventually completely folded into EAGER, remove
  // the special case below.
  if (info()->IsStub() && type == Deoptimizer::EAGER) {
    type = Deoptimizer::LAZY;
  }
  DeoptimizeIf(no_condition, instr, instr->hydrogen()->reason(), type);
}
 
 
void LCodeGen::DoDummy(LDummy* instr) {
  // Nothing to see here, move on!
}
 
 
void LCodeGen::DoDummyUse(LDummyUse* instr) {
  // Nothing to see here, move on!
}
 
 
void LCodeGen::DoDeferredStackCheck(LStackCheck* instr) {
  PushSafepointRegistersScope scope(this);
  __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
  __ CallRuntimeSaveDoubles(Runtime::kStackGuard);
  RecordSafepointWithLazyDeopt(instr, RECORD_SAFEPOINT_WITH_REGISTERS, 0);
  DCHECK(instr->HasEnvironment());
  LEnvironment* env = instr->environment();
  safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
}
 
 
void LCodeGen::DoStackCheck(LStackCheck* instr) {
  class DeferredStackCheck FINAL : public LDeferredCode {
   public:
    DeferredStackCheck(LCodeGen* codegen, LStackCheck* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() OVERRIDE {
      codegen()->DoDeferredStackCheck(instr_);
    }
    virtual LInstruction* instr() OVERRIDE { return instr_; }
   private:
    LStackCheck* instr_;
  };
 
  DCHECK(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;
    __ CompareRoot(rsp, Heap::kStackLimitRootIndex);
    __ j(above_equal, &done, Label::kNear);
 
    DCHECK(instr->context()->IsRegister());
    DCHECK(ToRegister(instr->context()).is(rsi));
    CallCode(isolate()->builtins()->StackCheck(),
             RelocInfo::CODE_TARGET,
             instr);
    __ bind(&done);
  } else {
    DCHECK(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);
    __ CompareRoot(rsp, Heap::kStackLimitRootIndex);
    __ j(below, deferred_stack_check->entry());
    EnsureSpaceForLazyDeopt(Deoptimizer::patch_size());
    __ 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();
 
  // If the environment were already registered, we would have no way of
  // backpatching it with the spill slot operands.
  DCHECK(!environment->HasBeenRegistered());
  RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
 
  GenerateOsrPrologue();
}
 
 
void LCodeGen::DoForInPrepareMap(LForInPrepareMap* instr) {
  DCHECK(ToRegister(instr->context()).is(rsi));
  __ CompareRoot(rax, Heap::kUndefinedValueRootIndex);
  DeoptimizeIf(equal, instr, "undefined");
 
  Register null_value = rdi;
  __ LoadRoot(null_value, Heap::kNullValueRootIndex);
  __ cmpp(rax, null_value);
  DeoptimizeIf(equal, instr, "null");
 
  Condition cc = masm()->CheckSmi(rax);
  DeoptimizeIf(cc, instr, "Smi");
 
  STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
  __ CmpObjectType(rax, LAST_JS_PROXY_TYPE, rcx);
  DeoptimizeIf(below_equal, instr, "wrong instance type");
 
  Label use_cache, call_runtime;
  __ CheckEnumCache(null_value, &call_runtime);
 
  __ movp(rax, FieldOperand(rax, HeapObject::kMapOffset));
  __ jmp(&use_cache, Label::kNear);
 
  // Get the set of properties to enumerate.
  __ bind(&call_runtime);
  __ Push(rax);
  CallRuntime(Runtime::kGetPropertyNamesFast, 1, instr);
 
  __ CompareRoot(FieldOperand(rax, HeapObject::kMapOffset),
                 Heap::kMetaMapRootIndex);
  DeoptimizeIf(not_equal, instr, "wrong map");
  __ 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, Smi::FromInt(0));
  __ j(not_equal, &load_cache, Label::kNear);
  __ LoadRoot(result, Heap::kEmptyFixedArrayRootIndex);
  __ jmp(&done, Label::kNear);
  __ bind(&load_cache);
  __ LoadInstanceDescriptors(map, result);
  __ movp(result,
          FieldOperand(result, DescriptorArray::kEnumCacheOffset));
  __ movp(result,
          FieldOperand(result, FixedArray::SizeFor(instr->idx())));
  __ bind(&done);
  Condition cc = masm()->CheckSmi(result);
  DeoptimizeIf(cc, instr, "no cache");
}
 
 
void LCodeGen::DoCheckMapValue(LCheckMapValue* instr) {
  Register object = ToRegister(instr->value());
  __ cmpp(ToRegister(instr->map()),
          FieldOperand(object, HeapObject::kMapOffset));
  DeoptimizeIf(not_equal, instr, "wrong map");
}
 
 
void LCodeGen::DoDeferredLoadMutableDouble(LLoadFieldByIndex* instr,
                                           Register object,
                                           Register index) {
  PushSafepointRegistersScope scope(this);
  __ Push(object);
  __ Push(index);
  __ xorp(rsi, rsi);
  __ CallRuntimeSaveDoubles(Runtime::kLoadMutableDouble);
  RecordSafepointWithRegisters(
      instr->pointer_map(), 2, Safepoint::kNoLazyDeopt);
  __ StoreToSafepointRegisterSlot(object, rax);
}
 
 
void LCodeGen::DoLoadFieldByIndex(LLoadFieldByIndex* instr) {
  class DeferredLoadMutableDouble FINAL : public LDeferredCode {
   public:
    DeferredLoadMutableDouble(LCodeGen* codegen,
                              LLoadFieldByIndex* instr,
                              Register object,
                              Register index)
        : LDeferredCode(codegen),
          instr_(instr),
          object_(object),
          index_(index) {
    }
    virtual void Generate() OVERRIDE {
      codegen()->DoDeferredLoadMutableDouble(instr_, object_, index_);
    }
    virtual LInstruction* instr() OVERRIDE { return instr_; }
   private:
    LLoadFieldByIndex* instr_;
    Register object_;
    Register index_;
  };
 
  Register object = ToRegister(instr->object());
  Register index = ToRegister(instr->index());
 
  DeferredLoadMutableDouble* deferred;
  deferred = new(zone()) DeferredLoadMutableDouble(this, instr, object, index);
 
  Label out_of_object, done;
  __ Move(kScratchRegister, Smi::FromInt(1));
  __ testp(index, kScratchRegister);
  __ j(not_zero, deferred->entry());
 
  __ sarp(index, Immediate(1));
 
  __ SmiToInteger32(index, index);
  __ cmpl(index, Immediate(0));
  __ j(less, &out_of_object, Label::kNear);
  __ movp(object, FieldOperand(object,
                               index,
                               times_pointer_size,
                               JSObject::kHeaderSize));
  __ jmp(&done, Label::kNear);
 
  __ bind(&out_of_object);
  __ movp(object, FieldOperand(object, JSObject::kPropertiesOffset));
  __ negl(index);
  // Index is now equal to out of object property index plus 1.
  __ movp(object, FieldOperand(object,
                               index,
                               times_pointer_size,
                               FixedArray::kHeaderSize - kPointerSize));
  __ bind(deferred->exit());
  __ bind(&done);
}
 
 
void LCodeGen::DoStoreFrameContext(LStoreFrameContext* instr) {
  Register context = ToRegister(instr->context());
  __ movp(Operand(rbp, StandardFrameConstants::kContextOffset), context);
}
 
 
void LCodeGen::DoAllocateBlockContext(LAllocateBlockContext* instr) {
  Handle<ScopeInfo> scope_info = instr->scope_info();
  __ Push(scope_info);
  __ Push(ToRegister(instr->function()));
  CallRuntime(Runtime::kPushBlockContext, 2, instr);
  RecordSafepoint(Safepoint::kNoLazyDeopt);
}
 
 
#undef __
 
} }  // namespace v8::internal
 
#endif  // V8_TARGET_ARCH_X64