lithium-codegen-mips.cc

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// Copyright 2012 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
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//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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#include "v8.h"

#include "mips/lithium-codegen-mips.h"
#include "mips/lithium-gap-resolver-mips.h"
#include "code-stubs.h"
#include "stub-cache.h"

namespace v8 {
namespace internal {


class SafepointGenerator : public CallWrapper {
 public:
  SafepointGenerator(LCodeGen* codegen,
                     LPointerMap* pointers,
                     Safepoint::DeoptMode mode)
      : codegen_(codegen),
        pointers_(pointers),
        deopt_mode_(mode) { }
  virtual ~SafepointGenerator() { }

  virtual void BeforeCall(int call_size) const { }

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

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


#define __ masm()->

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

  CodeStub::GenerateFPStubs();

  // Open a frame scope to indicate that there is a frame on the stack.  The
  // NONE indicates that the scope shouldn't actually generate code to set up
  // the frame (that is done in GeneratePrologue).
  FrameScope frame_scope(masm_, StackFrame::NONE);

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


void LCodeGen::FinishCode(Handle<Code> code) {
  ASSERT(is_done());
  code->set_stack_slots(GetStackSlotCount());
  code->set_safepoint_table_offset(safepoints_.GetCodeOffset());
  PopulateDeoptimizationData(code);
}


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


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

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


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

  ProfileEntryHookStub::MaybeCallEntryHook(masm_);

#ifdef DEBUG
  if (strlen(FLAG_stop_at) > 0 &&
      info_->function()->name()->IsEqualTo(CStrVector(FLAG_stop_at))) {
    __ stop("stop_at");
  }
#endif

  // a1: Callee's JS function.
  // cp: Callee's context.
  // fp: Caller's frame pointer.
  // lr: Caller's pc.

  // Strict mode functions and builtins need to replace the receiver
  // with undefined when called as functions (without an explicit
  // receiver object). r5 is zero for method calls and non-zero for
  // function calls.
  if (!info_->is_classic_mode() || info_->is_native()) {
    Label ok;
    __ Branch(&ok, eq, t1, Operand(zero_reg));

    int receiver_offset = scope()->num_parameters() * kPointerSize;
    __ LoadRoot(a2, Heap::kUndefinedValueRootIndex);
    __ sw(a2, MemOperand(sp, receiver_offset));
    __ bind(&ok);
  }

  __ Push(ra, fp, cp, a1);
  __ Addu(fp, sp, Operand(2 * kPointerSize));  // Adj. FP to point to saved FP.

  // Reserve space for the stack slots needed by the code.
  int slots = GetStackSlotCount();
  if (slots > 0) {
    if (FLAG_debug_code) {
      __ li(a0, Operand(slots));
      __ li(a2, Operand(kSlotsZapValue));
      Label loop;
      __ bind(&loop);
      __ push(a2);
      __ Subu(a0, a0, 1);
      __ Branch(&loop, ne, a0, Operand(zero_reg));
    } else {
      __ Subu(sp, sp, Operand(slots * kPointerSize));
    }
  }

  // Possibly allocate a local context.
  int heap_slots = scope()->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
  if (heap_slots > 0) {
    Comment(";;; Allocate local context");
    // Argument to NewContext is the function, which is in a1.
    __ push(a1);
    if (heap_slots <= FastNewContextStub::kMaximumSlots) {
      FastNewContextStub stub(heap_slots);
      __ CallStub(&stub);
    } else {
      __ CallRuntime(Runtime::kNewFunctionContext, 1);
    }
    RecordSafepoint(Safepoint::kNoLazyDeopt);
    // Context is returned in both v0 and cp.  It replaces the context
    // passed to us.  It's saved in the stack and kept live in cp.
    __ sw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
    // 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.
        __ lw(a0, MemOperand(fp, parameter_offset));
        // Store it in the context.
        MemOperand target = ContextOperand(cp, var->index());
        __ sw(a0, target);
        // Update the write barrier. This clobbers a3 and a0.
        __ RecordWriteContextSlot(
            cp, target.offset(), a0, a3, kRAHasBeenSaved, kSaveFPRegs);
      }
    }
    Comment(";;; End allocate local context");
  }

  // Trace the call.
  if (FLAG_trace) {
    __ CallRuntime(Runtime::kTraceEnter, 0);
  }
  EnsureSpaceForLazyDeopt();
  return !is_aborted();
}


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

    if (emit_instructions) {
      Comment(";;; @%d: %s.", current_instruction_, instr->Mnemonic());
      instr->CompileToNative(this);
    }
  }
  return !is_aborted();
}


bool LCodeGen::GenerateDeferredCode() {
  ASSERT(is_generating());
  if (deferred_.length() > 0) {
    for (int i = 0; !is_aborted() && i < deferred_.length(); i++) {
      LDeferredCode* code = deferred_[i];
      __ bind(code->entry());
      Comment(";;; Deferred code @%d: %s.",
              code->instruction_index(),
              code->instr()->Mnemonic());
      code->Generate();
      __ 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::GenerateDeoptJumpTable() {
  // TODO(plind): not clear that this will have advantage for MIPS.
  // Skipping it for now. Raised issue #100 for this.
  Abort("Unimplemented: GenerateDeoptJumpTable");
  return false;
}


bool LCodeGen::GenerateSafepointTable() {
  ASSERT(is_done());
  safepoints_.Emit(masm(), GetStackSlotCount());
  return !is_aborted();
}


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


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


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


Register LCodeGen::EmitLoadRegister(LOperand* op, Register scratch) {
  if (op->IsRegister()) {
    return ToRegister(op->index());
  } else if (op->IsConstantOperand()) {
    LConstantOperand* const_op = LConstantOperand::cast(op);
    HConstant* constant = chunk_->LookupConstant(const_op);
    Handle<Object> literal = constant->handle();
    Representation r = chunk_->LookupLiteralRepresentation(const_op);
    if (r.IsInteger32()) {
      ASSERT(literal->IsNumber());
      __ li(scratch, Operand(static_cast<int32_t>(literal->Number())));
    } else if (r.IsDouble()) {
      Abort("EmitLoadRegister: Unsupported double immediate.");
    } else {
      ASSERT(r.IsTagged());
      if (literal->IsSmi()) {
        __ li(scratch, Operand(literal));
      } else {
       __ LoadHeapObject(scratch, Handle<HeapObject>::cast(literal));
      }
    }
    return scratch;
  } else if (op->IsStackSlot() || op->IsArgument()) {
    __ lw(scratch, ToMemOperand(op));
    return scratch;
  }
  UNREACHABLE();
  return scratch;
}


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


DoubleRegister LCodeGen::EmitLoadDoubleRegister(LOperand* op,
                                                FloatRegister flt_scratch,
                                                DoubleRegister dbl_scratch) {
  if (op->IsDoubleRegister()) {
    return ToDoubleRegister(op->index());
  } else if (op->IsConstantOperand()) {
    LConstantOperand* const_op = LConstantOperand::cast(op);
    HConstant* constant = chunk_->LookupConstant(const_op);
    Handle<Object> literal = constant->handle();
    Representation r = chunk_->LookupLiteralRepresentation(const_op);
    if (r.IsInteger32()) {
      ASSERT(literal->IsNumber());
      __ li(at, Operand(static_cast<int32_t>(literal->Number())));
      __ mtc1(at, flt_scratch);
      __ cvt_d_w(dbl_scratch, flt_scratch);
      return dbl_scratch;
    } else if (r.IsDouble()) {
      Abort("unsupported double immediate");
    } else if (r.IsTagged()) {
      Abort("unsupported tagged immediate");
    }
  } else if (op->IsStackSlot() || op->IsArgument()) {
    MemOperand mem_op = ToMemOperand(op);
    __ ldc1(dbl_scratch, mem_op);
    return dbl_scratch;
  }
  UNREACHABLE();
  return dbl_scratch;
}


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


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


int LCodeGen::ToInteger32(LConstantOperand* op) const {
  HConstant* constant = chunk_->LookupConstant(op);
  ASSERT(chunk_->LookupLiteralRepresentation(op).IsInteger32());
  ASSERT(constant->HasInteger32Value());
  return constant->Integer32Value();
}


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


Operand LCodeGen::ToOperand(LOperand* op) {
  if (op->IsConstantOperand()) {
    LConstantOperand* const_op = LConstantOperand::cast(op);
    HConstant* constant = chunk()->LookupConstant(const_op);
    Representation r = chunk_->LookupLiteralRepresentation(const_op);
    if (r.IsInteger32()) {
      ASSERT(constant->HasInteger32Value());
      return Operand(constant->Integer32Value());
    } else if (r.IsDouble()) {
      Abort("ToOperand Unsupported double immediate.");
    }
    ASSERT(r.IsTagged());
    return Operand(constant->handle());
  } else if (op->IsRegister()) {
    return Operand(ToRegister(op));
  } else if (op->IsDoubleRegister()) {
    Abort("ToOperand IsDoubleRegister unimplemented");
    return Operand(0);
  }
  // Stack slots not implemented, use ToMemOperand instead.
  UNREACHABLE();
  return Operand(0);
}


MemOperand LCodeGen::ToMemOperand(LOperand* op) const {
  ASSERT(!op->IsRegister());
  ASSERT(!op->IsDoubleRegister());
  ASSERT(op->IsStackSlot() || op->IsDoubleStackSlot());
  int index = op->index();
  if (index >= 0) {
    // Local or spill slot. Skip the frame pointer, function, and
    // context in the fixed part of the frame.
    return MemOperand(fp, -(index + 3) * kPointerSize);
  } else {
    // Incoming parameter. Skip the return address.
    return MemOperand(fp, -(index - 1) * kPointerSize);
  }
}


MemOperand LCodeGen::ToHighMemOperand(LOperand* op) const {
  ASSERT(op->IsDoubleStackSlot());
  int index = op->index();
  if (index >= 0) {
    // Local or spill slot. Skip the frame pointer, function, context,
    // and the first word of the double in the fixed part of the frame.
    return MemOperand(fp, -(index + 3) * kPointerSize + kPointerSize);
  } else {
    // Incoming parameter. Skip the return address and the first word of
    // the double.
    return MemOperand(fp, -(index - 1) * kPointerSize + kPointerSize);
  }
}


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

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

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

  WriteTranslation(environment->outer(),
                   translation,
                   arguments_index,
                   arguments_count);
  int closure_id = *info()->closure() != *environment->closure()
      ? DefineDeoptimizationLiteral(environment->closure())
      : Translation::kSelfLiteralId;

  switch (environment->frame_type()) {
    case JS_FUNCTION:
      translation->BeginJSFrame(environment->ast_id(), closure_id, height);
      break;
    case JS_CONSTRUCT:
      translation->BeginConstructStubFrame(closure_id, translation_size);
      break;
    case JS_GETTER:
      ASSERT(translation_size == 1);
      ASSERT(height == 0);
      translation->BeginGetterStubFrame(closure_id);
      break;
    case JS_SETTER:
      ASSERT(translation_size == 2);
      ASSERT(height == 0);
      translation->BeginSetterStubFrame(closure_id);
      break;
    case ARGUMENTS_ADAPTOR:
      translation->BeginArgumentsAdaptorFrame(closure_id, translation_size);
      break;
  }

  // Inlined frames which push their arguments cause the index to be
  // bumped and a new stack area to be used for materialization.
  if (environment->entry() != NULL &&
      environment->entry()->arguments_pushed()) {
    *arguments_index = *arguments_index < 0
        ? GetStackSlotCount()
        : *arguments_index + *arguments_count;
    *arguments_count = environment->entry()->arguments_count() + 1;
  }

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

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


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


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


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


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

  __ CallRuntime(function, num_arguments);
  RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
}


void LCodeGen::CallRuntimeFromDeferred(Runtime::FunctionId id,
                                       int argc,
                                       LInstruction* instr) {
  __ CallRuntimeSaveDoubles(id);
  RecordSafepointWithRegisters(
      instr->pointer_map(), argc, Safepoint::kNoLazyDeopt);
}


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

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

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

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


void LCodeGen::DeoptimizeIf(Condition cc,
                            LEnvironment* environment,
                            Register src1,
                            const Operand& src2) {
  RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
  ASSERT(environment->HasBeenRegistered());
  int id = environment->deoptimization_index();
  Address entry = Deoptimizer::GetDeoptimizationEntry(id, Deoptimizer::EAGER);
  if (entry == NULL) {
    Abort("bailout was not prepared");
    return;
  }

  ASSERT(FLAG_deopt_every_n_times < 2);  // Other values not supported on MIPS.

  if (FLAG_deopt_every_n_times == 1 &&
      info_->shared_info()->opt_count() == id) {
    __ Jump(entry, RelocInfo::RUNTIME_ENTRY);
    return;
  }

  if (FLAG_trap_on_deopt) {
    Label skip;
    if (cc != al) {
      __ Branch(&skip, NegateCondition(cc), src1, src2);
    }
    __ stop("trap_on_deopt");
    __ bind(&skip);
  }

  // TODO(plind): The Arm port is a little different here, due to their
  // DeOpt jump table, which is not used for Mips yet.
  __ Jump(entry, RelocInfo::RUNTIME_ENTRY, cc, src1, src2);
}


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

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

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

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

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


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


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

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

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

  inlined_function_count_ = deoptimization_literals_.length();
}


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


void LCodeGen::RecordSafepoint(
    LPointerMap* pointers,
    Safepoint::Kind kind,
    int arguments,
    Safepoint::DeoptMode deopt_mode) {
  ASSERT(expected_safepoint_kind_ == 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());
    }
  }
  if (kind & Safepoint::kWithRegisters) {
    // Register cp always contains a pointer to the context.
    safepoint.DefinePointerRegister(cp, 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(RelocInfo::kNoPosition, 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::RecordSafepointWithRegistersAndDoubles(
    LPointerMap* pointers,
    int arguments,
    Safepoint::DeoptMode deopt_mode) {
  RecordSafepoint(
      pointers, Safepoint::kWithRegistersAndDoubles, arguments, deopt_mode);
}


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


void LCodeGen::DoLabel(LLabel* label) {
  if (label->is_loop_header()) {
    Comment(";;; B%d - LOOP entry", label->block_id());
  } else {
    Comment(";;; B%d", label->block_id());
  }
  __ bind(label->label());
  current_block_ = label->block_id();
  DoGap(label);
}


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


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


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


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


void LCodeGen::DoCallStub(LCallStub* instr) {
  ASSERT(ToRegister(instr->result()).is(v0));
  switch (instr->hydrogen()->major_key()) {
    case CodeStub::RegExpConstructResult: {
      RegExpConstructResultStub stub;
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
      break;
    }
    case CodeStub::RegExpExec: {
      RegExpExecStub stub;
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
      break;
    }
    case CodeStub::SubString: {
      SubStringStub stub;
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
      break;
    }
    case CodeStub::NumberToString: {
      NumberToStringStub stub;
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
      break;
    }
    case CodeStub::StringAdd: {
      StringAddStub stub(NO_STRING_ADD_FLAGS);
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
      break;
    }
    case CodeStub::StringCompare: {
      StringCompareStub stub;
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
      break;
    }
    case CodeStub::TranscendentalCache: {
      __ lw(a0, MemOperand(sp, 0));
      TranscendentalCacheStub stub(instr->transcendental_type(),
                                   TranscendentalCacheStub::TAGGED);
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
      break;
    }
    default:
      UNREACHABLE();
  }
}


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


void LCodeGen::DoModI(LModI* instr) {
  Register scratch = scratch0();
  const Register left = ToRegister(instr->left());
  const Register result = ToRegister(instr->result());

  Label done;

  if (instr->hydrogen()->HasPowerOf2Divisor()) {
    Register scratch = scratch0();
    ASSERT(!left.is(scratch));
    __ mov(scratch, left);
    int32_t p2constant = HConstant::cast(
        instr->hydrogen()->right())->Integer32Value();
    ASSERT(p2constant != 0);
    // Result always takes the sign of the dividend (left).
    p2constant = abs(p2constant);

    Label positive_dividend;
    __ Branch(USE_DELAY_SLOT, &positive_dividend, ge, left, Operand(zero_reg));
    __ subu(result, zero_reg, left);
    __ And(result, result, p2constant - 1);
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      DeoptimizeIf(eq, instr->environment(), result, Operand(zero_reg));
    }
    __ Branch(USE_DELAY_SLOT, &done);
    __ subu(result, zero_reg, result);
    __ bind(&positive_dividend);
    __ And(result, scratch, p2constant - 1);
  } else {
    // div runs in the background while we check for special cases.
    Register right = EmitLoadRegister(instr->right(), scratch);
    __ div(left, right);

    // Check for x % 0.
    if (instr->hydrogen()->CheckFlag(HValue::kCanBeDivByZero)) {
      DeoptimizeIf(eq, instr->environment(), right, Operand(zero_reg));
    }

    __ Branch(USE_DELAY_SLOT, &done, ge, left, Operand(zero_reg));
    __ mfhi(result);

    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      DeoptimizeIf(eq, instr->environment(), result, Operand(zero_reg));
    }
  }
  __ bind(&done);
}


void LCodeGen::DoDivI(LDivI* instr) {
  const Register left = ToRegister(instr->left());
  const Register right = ToRegister(instr->right());
  const Register result = ToRegister(instr->result());

  // On MIPS div is asynchronous - it will run in the background while we
  // check for special cases.
  __ div(left, right);

  // Check for x / 0.
  if (instr->hydrogen()->CheckFlag(HValue::kCanBeDivByZero)) {
    DeoptimizeIf(eq, instr->environment(), right, Operand(zero_reg));
  }

  // Check for (0 / -x) that will produce negative zero.
  if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
    Label left_not_zero;
    __ Branch(&left_not_zero, ne, left, Operand(zero_reg));
    DeoptimizeIf(lt, instr->environment(), right, Operand(zero_reg));
    __ bind(&left_not_zero);
  }

  // Check for (-kMinInt / -1).
  if (instr->hydrogen()->CheckFlag(HValue::kCanOverflow)) {
    Label left_not_min_int;
    __ Branch(&left_not_min_int, ne, left, Operand(kMinInt));
    DeoptimizeIf(eq, instr->environment(), right, Operand(-1));
    __ bind(&left_not_min_int);
  }

  __ mfhi(result);
  DeoptimizeIf(ne, instr->environment(), result, Operand(zero_reg));
  __ mflo(result);
}


void LCodeGen::DoMulI(LMulI* instr) {
  Register scratch = scratch0();
  Register result = ToRegister(instr->result());
  // Note that result may alias left.
  Register left = ToRegister(instr->left());
  LOperand* right_op = instr->right();

  bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
  bool bailout_on_minus_zero =
    instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero);

  if (right_op->IsConstantOperand() && !can_overflow) {
    // Use optimized code for specific constants.
    int32_t constant = ToInteger32(LConstantOperand::cast(right_op));

    if (bailout_on_minus_zero && (constant < 0)) {
      // The case of a null constant will be handled separately.
      // If constant is negative and left is null, the result should be -0.
      DeoptimizeIf(eq, instr->environment(), left, Operand(zero_reg));
    }

    switch (constant) {
      case -1:
        __ Subu(result, zero_reg, left);
        break;
      case 0:
        if (bailout_on_minus_zero) {
          // If left is strictly negative and the constant is null, the
          // result is -0. Deoptimize if required, otherwise return 0.
          DeoptimizeIf(lt, instr->environment(), left, Operand(zero_reg));
        }
        __ mov(result, zero_reg);
        break;
      case 1:
        // Nothing to do.
        __ Move(result, left);
        break;
      default:
        // Multiplying by powers of two and powers of two plus or minus
        // one can be done faster with shifted operands.
        // For other constants we emit standard code.
        int32_t mask = constant >> 31;
        uint32_t constant_abs = (constant + mask) ^ mask;

        if (IsPowerOf2(constant_abs) ||
            IsPowerOf2(constant_abs - 1) ||
            IsPowerOf2(constant_abs + 1)) {
          if (IsPowerOf2(constant_abs)) {
            int32_t shift = WhichPowerOf2(constant_abs);
            __ sll(result, left, shift);
          } else if (IsPowerOf2(constant_abs - 1)) {
            int32_t shift = WhichPowerOf2(constant_abs - 1);
            __ sll(result, left, shift);
            __ Addu(result, result, left);
          } else if (IsPowerOf2(constant_abs + 1)) {
            int32_t shift = WhichPowerOf2(constant_abs + 1);
            __ sll(result, left, shift);
            __ Subu(result, result, left);
          }

          // Correct the sign of the result is the constant is negative.
          if (constant < 0)  {
            __ Subu(result, zero_reg, result);
          }

        } else {
          // Generate standard code.
          __ li(at, constant);
          __ Mul(result, left, at);
        }
    }

  } else {
    Register right = EmitLoadRegister(right_op, scratch);
    if (bailout_on_minus_zero) {
      __ Or(ToRegister(instr->temp()), left, right);
    }

    if (can_overflow) {
      // hi:lo = left * right.
      __ mult(left, right);
      __ mfhi(scratch);
      __ mflo(result);
      __ sra(at, result, 31);
      DeoptimizeIf(ne, instr->environment(), scratch, Operand(at));
    } else {
      __ Mul(result, left, right);
    }

    if (bailout_on_minus_zero) {
      // Bail out if the result is supposed to be negative zero.
      Label done;
      __ Branch(&done, ne, result, Operand(zero_reg));
      DeoptimizeIf(lt,
                   instr->environment(),
                   ToRegister(instr->temp()),
                   Operand(zero_reg));
      __ bind(&done);
    }
  }
}


void LCodeGen::DoBitI(LBitI* instr) {
  LOperand* left_op = instr->left();
  LOperand* right_op = instr->right();
  ASSERT(left_op->IsRegister());
  Register left = ToRegister(left_op);
  Register result = ToRegister(instr->result());
  Operand right(no_reg);

  if (right_op->IsStackSlot() || right_op->IsArgument()) {
    right = Operand(EmitLoadRegister(right_op, at));
  } else {
    ASSERT(right_op->IsRegister() || right_op->IsConstantOperand());
    right = ToOperand(right_op);
  }

  switch (instr->op()) {
    case Token::BIT_AND:
      __ And(result, left, right);
      break;
    case Token::BIT_OR:
      __ Or(result, left, right);
      break;
    case Token::BIT_XOR:
      __ Xor(result, left, right);
      break;
    default:
      UNREACHABLE();
      break;
  }
}


void LCodeGen::DoShiftI(LShiftI* instr) {
  // Both 'left' and 'right' are "used at start" (see LCodeGen::DoShift), so
  // result may alias either of them.
  LOperand* right_op = instr->right();
  Register left = ToRegister(instr->left());
  Register result = ToRegister(instr->result());

  if (right_op->IsRegister()) {
    // No need to mask the right operand on MIPS, it is built into the variable
    // shift instructions.
    switch (instr->op()) {
      case Token::SAR:
        __ srav(result, left, ToRegister(right_op));
        break;
      case Token::SHR:
        __ srlv(result, left, ToRegister(right_op));
        if (instr->can_deopt()) {
          DeoptimizeIf(lt, instr->environment(), result, Operand(zero_reg));
        }
        break;
      case Token::SHL:
        __ sllv(result, left, ToRegister(right_op));
        break;
      default:
        UNREACHABLE();
        break;
    }
  } else {
    // Mask the right_op operand.
    int value = ToInteger32(LConstantOperand::cast(right_op));
    uint8_t shift_count = static_cast<uint8_t>(value & 0x1F);
    switch (instr->op()) {
      case Token::SAR:
        if (shift_count != 0) {
          __ sra(result, left, shift_count);
        } else {
          __ Move(result, left);
        }
        break;
      case Token::SHR:
        if (shift_count != 0) {
          __ srl(result, left, shift_count);
        } else {
          if (instr->can_deopt()) {
            __ And(at, left, Operand(0x80000000));
            DeoptimizeIf(ne, instr->environment(), at, Operand(zero_reg));
          }
          __ Move(result, left);
        }
        break;
      case Token::SHL:
        if (shift_count != 0) {
          __ sll(result, left, shift_count);
        } else {
          __ Move(result, left);
        }
        break;
      default:
        UNREACHABLE();
        break;
    }
  }
}


void LCodeGen::DoSubI(LSubI* instr) {
  LOperand* left = instr->left();
  LOperand* right = instr->right();
  LOperand* result = instr->result();
  bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);

  if (!can_overflow) {
    if (right->IsStackSlot() || right->IsArgument()) {
      Register right_reg = EmitLoadRegister(right, at);
      __ Subu(ToRegister(result), ToRegister(left), Operand(right_reg));
    } else {
      ASSERT(right->IsRegister() || right->IsConstantOperand());
      __ Subu(ToRegister(result), ToRegister(left), ToOperand(right));
    }
  } else {  // can_overflow.
    Register overflow = scratch0();
    Register scratch = scratch1();
    if (right->IsStackSlot() ||
        right->IsArgument() ||
        right->IsConstantOperand()) {
      Register right_reg = EmitLoadRegister(right, scratch);
      __ SubuAndCheckForOverflow(ToRegister(result),
                                 ToRegister(left),
                                 right_reg,
                                 overflow);  // Reg at also used as scratch.
    } else {
      ASSERT(right->IsRegister());
      // Due to overflow check macros not supporting constant operands,
      // handling the IsConstantOperand case was moved to prev if clause.
      __ SubuAndCheckForOverflow(ToRegister(result),
                                 ToRegister(left),
                                 ToRegister(right),
                                 overflow);  // Reg at also used as scratch.
    }
    DeoptimizeIf(lt, instr->environment(), overflow, Operand(zero_reg));
  }
}


void LCodeGen::DoConstantI(LConstantI* instr) {
  ASSERT(instr->result()->IsRegister());
  __ li(ToRegister(instr->result()), Operand(instr->value()));
}


void LCodeGen::DoConstantD(LConstantD* instr) {
  ASSERT(instr->result()->IsDoubleRegister());
  DoubleRegister result = ToDoubleRegister(instr->result());
  double v = instr->value();
  __ Move(result, v);
}


void LCodeGen::DoConstantT(LConstantT* instr) {
  Handle<Object> value = instr->value();
  if (value->IsSmi()) {
    __ li(ToRegister(instr->result()), Operand(value));
  } else {
    __ LoadHeapObject(ToRegister(instr->result()),
                      Handle<HeapObject>::cast(value));
  }
}


void LCodeGen::DoJSArrayLength(LJSArrayLength* instr) {
  Register result = ToRegister(instr->result());
  Register array = ToRegister(instr->value());
  __ lw(result, FieldMemOperand(array, JSArray::kLengthOffset));
}


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


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


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

  // Load map into |result|.
  __ lw(result, FieldMemOperand(input, HeapObject::kMapOffset));
  // Load the map's "bit field 2" into |result|. We only need the first byte,
  // but the following bit field extraction takes care of that anyway.
  __ lbu(result, FieldMemOperand(result, Map::kBitField2Offset));
  // Retrieve elements_kind from bit field 2.
  __ Ext(result, result, Map::kElementsKindShift, Map::kElementsKindBitCount);
}


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

  // If the object is a smi return the object.
  __ Move(result, input);
  __ JumpIfSmi(input, &done);

  // If the object is not a value type, return the object.
  __ GetObjectType(input, map, map);
  __ Branch(&done, ne, map, Operand(JS_VALUE_TYPE));
  __ lw(result, FieldMemOperand(input, JSValue::kValueOffset));

  __ bind(&done);
}


void LCodeGen::DoDateField(LDateField* instr) {
  Register object = ToRegister(instr->date());
  Register result = ToRegister(instr->result());
  Register scratch = ToRegister(instr->temp());
  Smi* index = instr->index();
  Label runtime, done;
  ASSERT(object.is(a0));
  ASSERT(result.is(v0));
  ASSERT(!scratch.is(scratch0()));
  ASSERT(!scratch.is(object));

  __ And(at, object, Operand(kSmiTagMask));
  DeoptimizeIf(eq, instr->environment(), at, Operand(zero_reg));
  __ GetObjectType(object, scratch, scratch);
  DeoptimizeIf(ne, instr->environment(), scratch, Operand(JS_DATE_TYPE));

  if (index->value() == 0) {
    __ lw(result, FieldMemOperand(object, JSDate::kValueOffset));
  } else {
    if (index->value() < JSDate::kFirstUncachedField) {
      ExternalReference stamp = ExternalReference::date_cache_stamp(isolate());
      __ li(scratch, Operand(stamp));
      __ lw(scratch, MemOperand(scratch));
      __ lw(scratch0(), FieldMemOperand(object, JSDate::kCacheStampOffset));
      __ Branch(&runtime, ne, scratch, Operand(scratch0()));
      __ lw(result, FieldMemOperand(object, JSDate::kValueOffset +
                                            kPointerSize * index->value()));
      __ jmp(&done);
    }
    __ bind(&runtime);
    __ PrepareCallCFunction(2, scratch);
    __ li(a1, Operand(index));
    __ CallCFunction(ExternalReference::get_date_field_function(isolate()), 2);
    __ bind(&done);
  }
}


void LCodeGen::DoBitNotI(LBitNotI* instr) {
  Register input = ToRegister(instr->value());
  Register result = ToRegister(instr->result());
  __ Nor(result, zero_reg, Operand(input));
}


void LCodeGen::DoThrow(LThrow* instr) {
  Register input_reg = EmitLoadRegister(instr->value(), at);
  __ push(input_reg);
  CallRuntime(Runtime::kThrow, 1, instr);

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


void LCodeGen::DoAddI(LAddI* instr) {
  LOperand* left = instr->left();
  LOperand* right = instr->right();
  LOperand* result = instr->result();
  bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);

  if (!can_overflow) {
    if (right->IsStackSlot() || right->IsArgument()) {
      Register right_reg = EmitLoadRegister(right, at);
      __ Addu(ToRegister(result), ToRegister(left), Operand(right_reg));
    } else {
      ASSERT(right->IsRegister() || right->IsConstantOperand());
      __ Addu(ToRegister(result), ToRegister(left), ToOperand(right));
    }
  } else {  // can_overflow.
    Register overflow = scratch0();
    Register scratch = scratch1();
    if (right->IsStackSlot() ||
        right->IsArgument() ||
        right->IsConstantOperand()) {
      Register right_reg = EmitLoadRegister(right, scratch);
      __ AdduAndCheckForOverflow(ToRegister(result),
                                 ToRegister(left),
                                 right_reg,
                                 overflow);  // Reg at also used as scratch.
    } else {
      ASSERT(right->IsRegister());
      // Due to overflow check macros not supporting constant operands,
      // handling the IsConstantOperand case was moved to prev if clause.
      __ AdduAndCheckForOverflow(ToRegister(result),
                                 ToRegister(left),
                                 ToRegister(right),
                                 overflow);  // Reg at also used as scratch.
    }
    DeoptimizeIf(lt, instr->environment(), overflow, Operand(zero_reg));
  }
}


void LCodeGen::DoMathMinMax(LMathMinMax* instr) {
  LOperand* left = instr->left();
  LOperand* right = instr->right();
  HMathMinMax::Operation operation = instr->hydrogen()->operation();
  Condition condition = (operation == HMathMinMax::kMathMin) ? le : ge;
  if (instr->hydrogen()->representation().IsInteger32()) {
    Register left_reg = ToRegister(left);
    Operand right_op = (right->IsRegister() || right->IsConstantOperand())
        ? ToOperand(right)
        : Operand(EmitLoadRegister(right, at));
    Register result_reg = ToRegister(instr->result());
    Label return_right, done;
    if (!result_reg.is(left_reg)) {
      __ Branch(&return_right, NegateCondition(condition), left_reg, right_op);
      __ mov(result_reg, left_reg);
      __ Branch(&done);
    }
    __ Branch(&done, condition, left_reg, right_op);
    __ bind(&return_right);
    __ Addu(result_reg, zero_reg, right_op);
    __ bind(&done);
  } else {
    ASSERT(instr->hydrogen()->representation().IsDouble());
    FPURegister left_reg = ToDoubleRegister(left);
    FPURegister right_reg = ToDoubleRegister(right);
    FPURegister result_reg = ToDoubleRegister(instr->result());
    Label check_nan_left, check_zero, return_left, return_right, done;
    __ BranchF(&check_zero, &check_nan_left, eq, left_reg, right_reg);
    __ BranchF(&return_left, NULL, condition, left_reg, right_reg);
    __ Branch(&return_right);

    __ bind(&check_zero);
    // left == right != 0.
    __ BranchF(&return_left, NULL, ne, left_reg, kDoubleRegZero);
    // At this point, both left and right are either 0 or -0.
    if (operation == HMathMinMax::kMathMin) {
      __ neg_d(left_reg, left_reg);
      __ sub_d(result_reg, left_reg, right_reg);
      __ neg_d(result_reg, result_reg);
    } else {
      __ add_d(result_reg, left_reg, right_reg);
    }
    __ Branch(&done);

    __ bind(&check_nan_left);
    // left == NaN.
    __ BranchF(NULL, &return_left, eq, left_reg, left_reg);
    __ bind(&return_right);
    if (!right_reg.is(result_reg)) {
      __ mov_d(result_reg, right_reg);
    }
    __ Branch(&done);

    __ bind(&return_left);
    if (!left_reg.is(result_reg)) {
      __ mov_d(result_reg, left_reg);
    }
    __ bind(&done);
  }
}


void LCodeGen::DoArithmeticD(LArithmeticD* instr) {
  DoubleRegister left = ToDoubleRegister(instr->left());
  DoubleRegister right = ToDoubleRegister(instr->right());
  DoubleRegister result = ToDoubleRegister(instr->result());
  switch (instr->op()) {
    case Token::ADD:
      __ add_d(result, left, right);
      break;
    case Token::SUB:
      __ sub_d(result, left, right);
      break;
    case Token::MUL:
      __ mul_d(result, left, right);
      break;
    case Token::DIV:
      __ div_d(result, left, right);
      break;
    case Token::MOD: {
      // Save a0-a3 on the stack.
      RegList saved_regs = a0.bit() | a1.bit() | a2.bit() | a3.bit();
      __ MultiPush(saved_regs);

      __ PrepareCallCFunction(0, 2, scratch0());
      __ SetCallCDoubleArguments(left, right);
      __ CallCFunction(
          ExternalReference::double_fp_operation(Token::MOD, isolate()),
          0, 2);
      // Move the result in the double result register.
      __ GetCFunctionDoubleResult(result);

      // Restore saved register.
      __ MultiPop(saved_regs);
      break;
    }
    default:
      UNREACHABLE();
      break;
  }
}


void LCodeGen::DoArithmeticT(LArithmeticT* instr) {
  ASSERT(ToRegister(instr->left()).is(a1));
  ASSERT(ToRegister(instr->right()).is(a0));
  ASSERT(ToRegister(instr->result()).is(v0));

  BinaryOpStub stub(instr->op(), NO_OVERWRITE);
  CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
  // Other arch use a nop here, to signal that there is no inlined
  // patchable code. Mips does not need the nop, since our marker
  // instruction (andi zero_reg) will never be used in normal code.
}


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


void LCodeGen::EmitBranch(int left_block, int right_block,
                          Condition cc, Register src1, const Operand& src2) {
  int next_block = GetNextEmittedBlock(current_block_);
  right_block = chunk_->LookupDestination(right_block);
  left_block = chunk_->LookupDestination(left_block);
  if (right_block == left_block) {
    EmitGoto(left_block);
  } else if (left_block == next_block) {
    __ Branch(chunk_->GetAssemblyLabel(right_block),
              NegateCondition(cc), src1, src2);
  } else if (right_block == next_block) {
    __ Branch(chunk_->GetAssemblyLabel(left_block), cc, src1, src2);
  } else {
    __ Branch(chunk_->GetAssemblyLabel(left_block), cc, src1, src2);
    __ Branch(chunk_->GetAssemblyLabel(right_block));
  }
}


void LCodeGen::EmitBranchF(int left_block, int right_block,
                           Condition cc, FPURegister src1, FPURegister src2) {
  int next_block = GetNextEmittedBlock(current_block_);
  right_block = chunk_->LookupDestination(right_block);
  left_block = chunk_->LookupDestination(left_block);
  if (right_block == left_block) {
    EmitGoto(left_block);
  } else if (left_block == next_block) {
    __ BranchF(chunk_->GetAssemblyLabel(right_block), NULL,
               NegateCondition(cc), src1, src2);
  } else if (right_block == next_block) {
    __ BranchF(chunk_->GetAssemblyLabel(left_block), NULL, cc, src1, src2);
  } else {
    __ BranchF(chunk_->GetAssemblyLabel(left_block), NULL, cc, src1, src2);
    __ Branch(chunk_->GetAssemblyLabel(right_block));
  }
}


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

  Representation r = instr->hydrogen()->value()->representation();
  if (r.IsInteger32()) {
    Register reg = ToRegister(instr->value());
    EmitBranch(true_block, false_block, ne, reg, Operand(zero_reg));
  } else if (r.IsDouble()) {
    DoubleRegister reg = ToDoubleRegister(instr->value());
    // Test the double value. Zero and NaN are false.
    EmitBranchF(true_block, false_block, ne, reg, kDoubleRegZero);
  } else {
    ASSERT(r.IsTagged());
    Register reg = ToRegister(instr->value());
    HType type = instr->hydrogen()->value()->type();
    if (type.IsBoolean()) {
      __ LoadRoot(at, Heap::kTrueValueRootIndex);
      EmitBranch(true_block, false_block, eq, reg, Operand(at));
    } else if (type.IsSmi()) {
      EmitBranch(true_block, false_block, ne, reg, Operand(zero_reg));
    } else {
      Label* true_label = chunk_->GetAssemblyLabel(true_block);
      Label* false_label = chunk_->GetAssemblyLabel(false_block);

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

      if (expected.Contains(ToBooleanStub::UNDEFINED)) {
        // undefined -> false.
        __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
        __ Branch(false_label, eq, reg, Operand(at));
      }
      if (expected.Contains(ToBooleanStub::BOOLEAN)) {
        // Boolean -> its value.
        __ LoadRoot(at, Heap::kTrueValueRootIndex);
        __ Branch(true_label, eq, reg, Operand(at));
        __ LoadRoot(at, Heap::kFalseValueRootIndex);
        __ Branch(false_label, eq, reg, Operand(at));
      }
      if (expected.Contains(ToBooleanStub::NULL_TYPE)) {
        // 'null' -> false.
        __ LoadRoot(at, Heap::kNullValueRootIndex);
        __ Branch(false_label, eq, reg, Operand(at));
      }

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

      const Register map = scratch0();
      if (expected.NeedsMap()) {
        __ lw(map, FieldMemOperand(reg, HeapObject::kMapOffset));
        if (expected.CanBeUndetectable()) {
          // Undetectable -> false.
          __ lbu(at, FieldMemOperand(map, Map::kBitFieldOffset));
          __ And(at, at, Operand(1 << Map::kIsUndetectable));
          __ Branch(false_label, ne, at, Operand(zero_reg));
        }
      }

      if (expected.Contains(ToBooleanStub::SPEC_OBJECT)) {
        // spec object -> true.
        __ lbu(at, FieldMemOperand(map, Map::kInstanceTypeOffset));
        __ Branch(true_label, ge, at, Operand(FIRST_SPEC_OBJECT_TYPE));
      }

      if (expected.Contains(ToBooleanStub::STRING)) {
        // String value -> false iff empty.
        Label not_string;
        __ lbu(at, FieldMemOperand(map, Map::kInstanceTypeOffset));
        __ Branch(&not_string, ge , at, Operand(FIRST_NONSTRING_TYPE));
        __ lw(at, FieldMemOperand(reg, String::kLengthOffset));
        __ Branch(true_label, ne, at, Operand(zero_reg));
        __ Branch(false_label);
        __ bind(&not_string);
      }

      if (expected.Contains(ToBooleanStub::HEAP_NUMBER)) {
        // heap number -> false iff +0, -0, or NaN.
        DoubleRegister dbl_scratch = double_scratch0();
        Label not_heap_number;
        __ LoadRoot(at, Heap::kHeapNumberMapRootIndex);
        __ Branch(&not_heap_number, ne, map, Operand(at));
        __ ldc1(dbl_scratch, FieldMemOperand(reg, HeapNumber::kValueOffset));
        __ BranchF(true_label, false_label, ne, dbl_scratch, kDoubleRegZero);
        // Falls through if dbl_scratch == 0.
        __ Branch(false_label);
        __ bind(&not_heap_number);
      }

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


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


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


Condition LCodeGen::TokenToCondition(Token::Value op, bool is_unsigned) {
  Condition cond = kNoCondition;
  switch (op) {
    case Token::EQ:
    case Token::EQ_STRICT:
      cond = eq;
      break;
    case Token::LT:
      cond = is_unsigned ? lo : lt;
      break;
    case Token::GT:
      cond = is_unsigned ? hi : gt;
      break;
    case Token::LTE:
      cond = is_unsigned ? ls : le;
      break;
    case Token::GTE:
      cond = is_unsigned ? hs : ge;
      break;
    case Token::IN:
    case Token::INSTANCEOF:
    default:
      UNREACHABLE();
  }
  return cond;
}


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

  Condition cond = TokenToCondition(instr->op(), false);

  if (left->IsConstantOperand() && right->IsConstantOperand()) {
    // We can statically evaluate the comparison.
    double left_val = ToDouble(LConstantOperand::cast(left));
    double right_val = ToDouble(LConstantOperand::cast(right));
    int next_block =
      EvalComparison(instr->op(), left_val, right_val) ? true_block
                                                       : false_block;
    EmitGoto(next_block);
  } else {
    if (instr->is_double()) {
      // Compare left and right as doubles and load the
      // resulting flags into the normal status register.
      FPURegister left_reg = ToDoubleRegister(left);
      FPURegister right_reg = ToDoubleRegister(right);

      // If a NaN is involved, i.e. the result is unordered,
      // jump to false block label.
      __ BranchF(NULL, chunk_->GetAssemblyLabel(false_block), eq,
                 left_reg, right_reg);

      EmitBranchF(true_block, false_block, cond, left_reg, right_reg);
    } else {
      Register cmp_left;
      Operand cmp_right = Operand(0);

      if (right->IsConstantOperand()) {
        cmp_left = ToRegister(left);
        cmp_right = Operand(ToInteger32(LConstantOperand::cast(right)));
      } else if (left->IsConstantOperand()) {
        cmp_left = ToRegister(right);
        cmp_right = Operand(ToInteger32(LConstantOperand::cast(left)));
        // We transposed the operands. Reverse the condition.
        cond = ReverseCondition(cond);
      } else {
        cmp_left = ToRegister(left);
        cmp_right = Operand(ToRegister(right));
      }

      EmitBranch(true_block, false_block, cond, cmp_left, cmp_right);
    }
  }
}


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

  EmitBranch(true_block, false_block, eq, left, Operand(right));
}


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

  EmitBranch(true_block, false_block, eq, left,
             Operand(instr->hydrogen()->right()));
}



void LCodeGen::DoIsNilAndBranch(LIsNilAndBranch* instr) {
  Register scratch = scratch0();
  Register reg = ToRegister(instr->value());
  int false_block = chunk_->LookupDestination(instr->false_block_id());

  // If the expression is known to be untagged or a smi, then it's definitely
  // not null, and it can't be a an undetectable object.
  if (instr->hydrogen()->representation().IsSpecialization() ||
      instr->hydrogen()->type().IsSmi()) {
    EmitGoto(false_block);
    return;
  }

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

  Heap::RootListIndex nil_value = instr->nil() == kNullValue ?
      Heap::kNullValueRootIndex :
      Heap::kUndefinedValueRootIndex;
  __ LoadRoot(at, nil_value);
  if (instr->kind() == kStrictEquality) {
    EmitBranch(true_block, false_block, eq, reg, Operand(at));
  } else {
    Heap::RootListIndex other_nil_value = instr->nil() == kNullValue ?
        Heap::kUndefinedValueRootIndex :
        Heap::kNullValueRootIndex;
    Label* true_label = chunk_->GetAssemblyLabel(true_block);
    Label* false_label = chunk_->GetAssemblyLabel(false_block);
    __ Branch(USE_DELAY_SLOT, true_label, eq, reg, Operand(at));
    __ LoadRoot(at, other_nil_value);  // In the delay slot.
    __ Branch(USE_DELAY_SLOT, true_label, eq, reg, Operand(at));
    __ JumpIfSmi(reg, false_label);  // In the delay slot.
    // Check for undetectable objects by looking in the bit field in
    // the map. The object has already been smi checked.
    __ lw(scratch, FieldMemOperand(reg, HeapObject::kMapOffset));
    __ lbu(scratch, FieldMemOperand(scratch, Map::kBitFieldOffset));
    __ And(scratch, scratch, 1 << Map::kIsUndetectable);
    EmitBranch(true_block, false_block, ne, scratch, Operand(zero_reg));
  }
}


Condition LCodeGen::EmitIsObject(Register input,
                                 Register temp1,
                                 Register temp2,
                                 Label* is_not_object,
                                 Label* is_object) {
  __ JumpIfSmi(input, is_not_object);

  __ LoadRoot(temp2, Heap::kNullValueRootIndex);
  __ Branch(is_object, eq, input, Operand(temp2));

  // Load map.
  __ lw(temp1, FieldMemOperand(input, HeapObject::kMapOffset));
  // Undetectable objects behave like undefined.
  __ lbu(temp2, FieldMemOperand(temp1, Map::kBitFieldOffset));
  __ And(temp2, temp2, Operand(1 << Map::kIsUndetectable));
  __ Branch(is_not_object, ne, temp2, Operand(zero_reg));

  // Load instance type and check that it is in object type range.
  __ lbu(temp2, FieldMemOperand(temp1, Map::kInstanceTypeOffset));
  __ Branch(is_not_object,
            lt, temp2, Operand(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));

  return le;
}


void LCodeGen::DoIsObjectAndBranch(LIsObjectAndBranch* instr) {
  Register reg = ToRegister(instr->value());
  Register temp1 = ToRegister(instr->temp());
  Register temp2 = scratch0();

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

  Condition true_cond =
      EmitIsObject(reg, temp1, temp2, false_label, true_label);

  EmitBranch(true_block, false_block, true_cond, temp2,
             Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE));
}


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

  return lt;
}


void LCodeGen::DoIsStringAndBranch(LIsStringAndBranch* instr) {
  Register reg = ToRegister(instr->value());
  Register temp1 = ToRegister(instr->temp());

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

  Condition true_cond =
      EmitIsString(reg, temp1, false_label);

  EmitBranch(true_block, false_block, true_cond, temp1,
             Operand(FIRST_NONSTRING_TYPE));
}


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

  Register input_reg = EmitLoadRegister(instr->value(), at);
  __ And(at, input_reg, kSmiTagMask);
  EmitBranch(true_block, false_block, eq, at, Operand(zero_reg));
}


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

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

  __ JumpIfSmi(input, chunk_->GetAssemblyLabel(false_block));
  __ lw(temp, FieldMemOperand(input, HeapObject::kMapOffset));
  __ lbu(temp, FieldMemOperand(temp, Map::kBitFieldOffset));
  __ And(at, temp, Operand(1 << Map::kIsUndetectable));
  EmitBranch(true_block, false_block, ne, at, Operand(zero_reg));
}


static Condition ComputeCompareCondition(Token::Value op) {
  switch (op) {
    case Token::EQ_STRICT:
    case Token::EQ:
      return eq;
    case Token::LT:
      return lt;
    case Token::GT:
      return gt;
    case Token::LTE:
      return le;
    case Token::GTE:
      return ge;
    default:
      UNREACHABLE();
      return kNoCondition;
  }
}


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

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

  Condition condition = ComputeCompareCondition(op);

  EmitBranch(true_block, false_block, condition, v0, Operand(zero_reg));
}


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


static Condition BranchCondition(HHasInstanceTypeAndBranch* instr) {
  InstanceType from = instr->from();
  InstanceType to = instr->to();
  if (from == to) return eq;
  if (to == LAST_TYPE) return hs;
  if (from == FIRST_TYPE) return ls;
  UNREACHABLE();
  return eq;
}


void LCodeGen::DoHasInstanceTypeAndBranch(LHasInstanceTypeAndBranch* instr) {
  Register scratch = scratch0();
  Register input = ToRegister(instr->value());

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

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

  __ JumpIfSmi(input, false_label);

  __ GetObjectType(input, scratch, scratch);
  EmitBranch(true_block,
             false_block,
             BranchCondition(instr->hydrogen()),
             scratch,
             Operand(TestType(instr->hydrogen())));
}


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

  __ AssertString(input);

  __ lw(result, FieldMemOperand(input, String::kHashFieldOffset));
  __ IndexFromHash(result, result);
}


void LCodeGen::DoHasCachedArrayIndexAndBranch(
    LHasCachedArrayIndexAndBranch* instr) {
  Register input = ToRegister(instr->value());
  Register scratch = scratch0();

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

  __ lw(scratch,
         FieldMemOperand(input, String::kHashFieldOffset));
  __ And(at, scratch, Operand(String::kContainsCachedArrayIndexMask));
  EmitBranch(true_block, false_block, eq, at, Operand(zero_reg));
}


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

  __ JumpIfSmi(input, is_false);

  if (class_name->IsEqualTo(CStrVector("Function"))) {
    // Assuming the following assertions, we can use the same compares to test
    // for both being a function type and being in the object type range.
    STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
    STATIC_ASSERT(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE ==
                  FIRST_SPEC_OBJECT_TYPE + 1);
    STATIC_ASSERT(LAST_NONCALLABLE_SPEC_OBJECT_TYPE ==
                  LAST_SPEC_OBJECT_TYPE - 1);
    STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);

    __ GetObjectType(input, temp, temp2);
    __ Branch(is_false, lt, temp2, Operand(FIRST_SPEC_OBJECT_TYPE));
    __ Branch(is_true, eq, temp2, Operand(FIRST_SPEC_OBJECT_TYPE));
    __ Branch(is_true, eq, temp2, Operand(LAST_SPEC_OBJECT_TYPE));
  } 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.
    __ GetObjectType(input, temp, temp2);
    __ Subu(temp2, temp2, Operand(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
    __ Branch(is_false, gt, temp2, Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE -
                                           FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
  }

  // Now we are in the FIRST-LAST_NONCALLABLE_SPEC_OBJECT_TYPE range.
  // Check if the constructor in the map is a function.
  __ lw(temp, FieldMemOperand(temp, Map::kConstructorOffset));

  // Objects with a non-function constructor have class 'Object'.
  __ GetObjectType(temp, temp2, temp2);
  if (class_name->IsEqualTo(CStrVector("Object"))) {
    __ Branch(is_true, ne, temp2, Operand(JS_FUNCTION_TYPE));
  } else {
    __ Branch(is_false, ne, temp2, Operand(JS_FUNCTION_TYPE));
  }

  // temp now contains the constructor function. Grab the
  // instance class name from there.
  __ lw(temp, FieldMemOperand(temp, JSFunction::kSharedFunctionInfoOffset));
  __ lw(temp, FieldMemOperand(temp,
                               SharedFunctionInfo::kInstanceClassNameOffset));
  // The class name we are testing against is a symbol because it's a literal.
  // The name in the constructor is a symbol 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 symbols it is sufficient to use an identity
  // comparison.

  // End with the address of this class_name instance in temp register.
  // On MIPS, the caller must do the comparison with Handle<String>class_name.
}


void LCodeGen::DoClassOfTestAndBranch(LClassOfTestAndBranch* instr) {
  Register input = ToRegister(instr->value());
  Register temp = scratch0();
  Register temp2 = ToRegister(instr->temp());
  Handle<String> class_name = instr->hydrogen()->class_name();

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

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

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

  EmitBranch(true_block, false_block, eq, temp, Operand(class_name));
}


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

  __ lw(temp, FieldMemOperand(reg, HeapObject::kMapOffset));
  EmitBranch(true_block, false_block, eq, temp, Operand(instr->map()));
}


void LCodeGen::DoInstanceOf(LInstanceOf* instr) {
  Label true_label, done;
  ASSERT(ToRegister(instr->left()).is(a0));  // Object is in a0.
  ASSERT(ToRegister(instr->right()).is(a1));  // Function is in a1.
  Register result = ToRegister(instr->result());
  ASSERT(result.is(v0));

  InstanceofStub stub(InstanceofStub::kArgsInRegisters);
  CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);

  __ Branch(&true_label, eq, result, Operand(zero_reg));
  __ li(result, Operand(factory()->false_value()));
  __ Branch(&done);
  __ bind(&true_label);
  __ li(result, Operand(factory()->true_value()));
  __ bind(&done);
}


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

   private:
    LInstanceOfKnownGlobal* instr_;
    Label map_check_;
  };

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

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

  ASSERT(object.is(a0));
  ASSERT(result.is(v0));

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

  // This is the inlined call site instanceof cache. The two occurences of the
  // hole value will be patched to the last map/result pair generated by the
  // instanceof stub.
  Label cache_miss;
  Register map = temp;
  __ lw(map, FieldMemOperand(object, HeapObject::kMapOffset));

  Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_);
  __ bind(deferred->map_check());  // Label for calculating code patching.
  // We use Factory::the_hole_value() on purpose instead of loading from the
  // root array to force relocation to be able to later patch with
  // the cached map.
  Handle<JSGlobalPropertyCell> cell =
      factory()->NewJSGlobalPropertyCell(factory()->the_hole_value());
  __ li(at, Operand(Handle<Object>(cell)));
  __ lw(at, FieldMemOperand(at, JSGlobalPropertyCell::kValueOffset));
  __ Branch(&cache_miss, ne, map, Operand(at));
  // We use Factory::the_hole_value() on purpose instead of loading from the
  // root array to force relocation to be able to later patch
  // with true or false.
  __ li(result, Operand(factory()->the_hole_value()), CONSTANT_SIZE);
  __ Branch(&done);

  // The inlined call site cache did not match. Check null and string before
  // calling the deferred code.
  __ bind(&cache_miss);
  // Null is not instance of anything.
  __ LoadRoot(temp, Heap::kNullValueRootIndex);
  __ Branch(&false_result, eq, object, Operand(temp));

  // String values is not instance of anything.
  Condition cc = __ IsObjectStringType(object, temp, temp);
  __ Branch(&false_result, cc, temp, Operand(zero_reg));

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

  __ bind(&false_result);
  __ LoadRoot(result, Heap::kFalseValueRootIndex);

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


void LCodeGen::DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,
                                               Label* map_check) {
  Register result = ToRegister(instr->result());
  ASSERT(result.is(v0));

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

  PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);

  // Get the temp register reserved by the instruction. This needs to be t0 as
  // its slot of the pushing of safepoint registers is used to communicate the
  // offset to the location of the map check.
  Register temp = ToRegister(instr->temp());
  ASSERT(temp.is(t0));
  __ LoadHeapObject(InstanceofStub::right(), instr->function());
  static const int kAdditionalDelta = 7;
  int delta = masm_->InstructionsGeneratedSince(map_check) + kAdditionalDelta;
  Label before_push_delta;
  __ bind(&before_push_delta);
  {
    Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_);
    __ li(temp, Operand(delta * kPointerSize), CONSTANT_SIZE);
    __ StoreToSafepointRegisterSlot(temp, temp);
  }
  CallCodeGeneric(stub.GetCode(),
                  RelocInfo::CODE_TARGET,
                  instr,
                  RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
  LEnvironment* env = instr->GetDeferredLazyDeoptimizationEnvironment();
  safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
  // Put the result value into the result register slot and
  // restore all registers.
  __ StoreToSafepointRegisterSlot(result, result);
}


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

  Handle<Code> ic = CompareIC::GetUninitialized(op);
  CallCode(ic, RelocInfo::CODE_TARGET, instr);
  // On MIPS there is no need for a "no inlined smi code" marker (nop).

  Condition condition = ComputeCompareCondition(op);
  // A minor optimization that relies on LoadRoot always emitting one
  // instruction.
  Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm());
  Label done;
  __ Branch(USE_DELAY_SLOT, &done, condition, v0, Operand(zero_reg));
  __ LoadRoot(ToRegister(instr->result()), Heap::kTrueValueRootIndex);
  __ LoadRoot(ToRegister(instr->result()), Heap::kFalseValueRootIndex);
  ASSERT_EQ(3, masm()->InstructionsGeneratedSince(&done));
  __ bind(&done);
}


void LCodeGen::DoReturn(LReturn* instr) {
  if (FLAG_trace) {
    // Push the return value on the stack as the parameter.
    // Runtime::TraceExit returns its parameter in v0.
    __ push(v0);
    __ CallRuntime(Runtime::kTraceExit, 1);
  }
  int32_t sp_delta = (GetParameterCount() + 1) * kPointerSize;
  __ mov(sp, fp);
  __ Pop(ra, fp);
  __ Addu(sp, sp, Operand(sp_delta));
  __ Jump(ra);
}


void LCodeGen::DoLoadGlobalCell(LLoadGlobalCell* instr) {
  Register result = ToRegister(instr->result());
  __ li(at, Operand(Handle<Object>(instr->hydrogen()->cell())));
  __ lw(result, FieldMemOperand(at, JSGlobalPropertyCell::kValueOffset));
  if (instr->hydrogen()->RequiresHoleCheck()) {
    __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
    DeoptimizeIf(eq, instr->environment(), result, Operand(at));
  }
}


void LCodeGen::DoLoadGlobalGeneric(LLoadGlobalGeneric* instr) {
  ASSERT(ToRegister(instr->global_object()).is(a0));
  ASSERT(ToRegister(instr->result()).is(v0));

  __ li(a2, Operand(instr->name()));
  RelocInfo::Mode mode = instr->for_typeof() ? RelocInfo::CODE_TARGET
                                             : RelocInfo::CODE_TARGET_CONTEXT;
  Handle<Code> ic = isolate()->builtins()->LoadIC_Initialize();
  CallCode(ic, mode, instr);
}


void LCodeGen::DoStoreGlobalCell(LStoreGlobalCell* instr) {
  Register value = ToRegister(instr->value());
  Register cell = scratch0();

  // Load the cell.
  __ li(cell, Operand(instr->hydrogen()->cell()));

  // If the cell we are storing to contains the hole it could have
  // been deleted from the property dictionary. In that case, we need
  // to update the property details in the property dictionary to mark
  // it as no longer deleted.
  if (instr->hydrogen()->RequiresHoleCheck()) {
    // We use a temp to check the payload.
    Register payload = ToRegister(instr->temp());
    __ lw(payload, FieldMemOperand(cell, JSGlobalPropertyCell::kValueOffset));
    __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
    DeoptimizeIf(eq, instr->environment(), payload, Operand(at));
  }

  // Store the value.
  __ sw(value, FieldMemOperand(cell, JSGlobalPropertyCell::kValueOffset));
  // Cells are always rescanned, so no write barrier here.
}


void LCodeGen::DoStoreGlobalGeneric(LStoreGlobalGeneric* instr) {
  ASSERT(ToRegister(instr->global_object()).is(a1));
  ASSERT(ToRegister(instr->value()).is(a0));

  __ li(a2, Operand(instr->name()));
  Handle<Code> ic = (instr->strict_mode_flag() == kStrictMode)
      ? isolate()->builtins()->StoreIC_Initialize_Strict()
      : isolate()->builtins()->StoreIC_Initialize();
  CallCode(ic, RelocInfo::CODE_TARGET_CONTEXT, instr);
}


void LCodeGen::DoLoadContextSlot(LLoadContextSlot* instr) {
  Register context = ToRegister(instr->context());
  Register result = ToRegister(instr->result());

  __ lw(result, ContextOperand(context, instr->slot_index()));
  if (instr->hydrogen()->RequiresHoleCheck()) {
    __ LoadRoot(at, Heap::kTheHoleValueRootIndex);

    if (instr->hydrogen()->DeoptimizesOnHole()) {
      DeoptimizeIf(eq, instr->environment(), result, Operand(at));
    } else {
      Label is_not_hole;
      __ Branch(&is_not_hole, ne, result, Operand(at));
      __ LoadRoot(result, Heap::kUndefinedValueRootIndex);
      __ bind(&is_not_hole);
    }
  }
}


void LCodeGen::DoStoreContextSlot(LStoreContextSlot* instr) {
  Register context = ToRegister(instr->context());
  Register value = ToRegister(instr->value());
  Register scratch = scratch0();
  MemOperand target = ContextOperand(context, instr->slot_index());

  Label skip_assignment;

  if (instr->hydrogen()->RequiresHoleCheck()) {
    __ lw(scratch, target);
    __ LoadRoot(at, Heap::kTheHoleValueRootIndex);

    if (instr->hydrogen()->DeoptimizesOnHole()) {
      DeoptimizeIf(eq, instr->environment(), scratch, Operand(at));
    } else {
      __ Branch(&skip_assignment, ne, scratch, Operand(at));
    }
  }

  __ sw(value, target);
  if (instr->hydrogen()->NeedsWriteBarrier()) {
    HType type = instr->hydrogen()->value()->type();
    SmiCheck check_needed =
        type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
    __ RecordWriteContextSlot(context,
                              target.offset(),
                              value,
                              scratch0(),
                              kRAHasBeenSaved,
                              kSaveFPRegs,
                              EMIT_REMEMBERED_SET,
                              check_needed);
  }

  __ bind(&skip_assignment);
}


void LCodeGen::DoLoadNamedField(LLoadNamedField* instr) {
  Register object = ToRegister(instr->object());
  Register result = ToRegister(instr->result());
  if (instr->hydrogen()->is_in_object()) {
    __ lw(result, FieldMemOperand(object, instr->hydrogen()->offset()));
  } else {
    __ lw(result, FieldMemOperand(object, JSObject::kPropertiesOffset));
    __ lw(result, FieldMemOperand(result, instr->hydrogen()->offset()));
  }
}


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


void LCodeGen::DoLoadNamedFieldPolymorphic(LLoadNamedFieldPolymorphic* instr) {
  Register object = ToRegister(instr->object());
  Register result = ToRegister(instr->result());
  Register object_map = scratch0();

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

  if (map_count == 0 && !need_generic) {
    DeoptimizeIf(al, instr->environment());
    return;
  }
  Handle<String> name = instr->hydrogen()->name();
  Label done;
  __ lw(object_map, FieldMemOperand(object, HeapObject::kMapOffset));
  for (int i = 0; i < map_count; ++i) {
    bool last = (i == map_count - 1);
    Handle<Map> map = instr->hydrogen()->types()->at(i);
    Label check_passed;
    __ CompareMapAndBranch(
        object_map, map, &check_passed,
        eq, &check_passed, ALLOW_ELEMENT_TRANSITION_MAPS);
    if (last && !need_generic) {
      DeoptimizeIf(al, instr->environment());
      __ bind(&check_passed);
      EmitLoadFieldOrConstantFunction(
          result, object, map, name, instr->environment());
    } else {
      Label next;
      __ Branch(&next);
      __ bind(&check_passed);
      EmitLoadFieldOrConstantFunction(
          result, object, map, name, instr->environment());
      __ Branch(&done);
      __ bind(&next);
    }
  }
  if (need_generic) {
    __ li(a2, Operand(name));
    Handle<Code> ic = isolate()->builtins()->LoadIC_Initialize();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
  }
  __ bind(&done);
}


void LCodeGen::DoLoadNamedGeneric(LLoadNamedGeneric* instr) {
  ASSERT(ToRegister(instr->object()).is(a0));
  ASSERT(ToRegister(instr->result()).is(v0));

  // Name is always in a2.
  __ li(a2, Operand(instr->name()));
  Handle<Code> ic = isolate()->builtins()->LoadIC_Initialize();
  CallCode(ic, RelocInfo::CODE_TARGET, instr);
}


void LCodeGen::DoLoadFunctionPrototype(LLoadFunctionPrototype* instr) {
  Register scratch = scratch0();
  Register function = ToRegister(instr->function());
  Register result = ToRegister(instr->result());

  // Check that the function really is a function. Load map into the
  // result register.
  __ GetObjectType(function, result, scratch);
  DeoptimizeIf(ne, instr->environment(), scratch, Operand(JS_FUNCTION_TYPE));

  // Make sure that the function has an instance prototype.
  Label non_instance;
  __ lbu(scratch, FieldMemOperand(result, Map::kBitFieldOffset));
  __ And(scratch, scratch, Operand(1 << Map::kHasNonInstancePrototype));
  __ Branch(&non_instance, ne, scratch, Operand(zero_reg));

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

  // Check that the function has a prototype or an initial map.
  __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
  DeoptimizeIf(eq, instr->environment(), result, Operand(at));

  // If the function does not have an initial map, we're done.
  Label done;
  __ GetObjectType(result, scratch, scratch);
  __ Branch(&done, ne, scratch, Operand(MAP_TYPE));

  // Get the prototype from the initial map.
  __ lw(result, FieldMemOperand(result, Map::kPrototypeOffset));
  __ Branch(&done);

  // Non-instance prototype: Fetch prototype from constructor field
  // in initial map.
  __ bind(&non_instance);
  __ lw(result, FieldMemOperand(result, Map::kConstructorOffset));

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


void LCodeGen::DoLoadElements(LLoadElements* instr) {
  Register result = ToRegister(instr->result());
  Register input = ToRegister(instr->object());
  Register scratch = scratch0();

  __ lw(result, FieldMemOperand(input, JSObject::kElementsOffset));
  if (FLAG_debug_code) {
    Label done, fail;
    __ lw(scratch, FieldMemOperand(result, HeapObject::kMapOffset));
    __ LoadRoot(at, Heap::kFixedArrayMapRootIndex);
    __ Branch(USE_DELAY_SLOT, &done, eq, scratch, Operand(at));
    __ LoadRoot(at, Heap::kFixedCOWArrayMapRootIndex);  // In the delay slot.
    __ Branch(&done, eq, scratch, Operand(at));
    // |scratch| still contains |input|'s map.
    __ lbu(scratch, FieldMemOperand(scratch, Map::kBitField2Offset));
    __ Ext(scratch, scratch, Map::kElementsKindShift,
           Map::kElementsKindBitCount);
    __ Branch(&fail, lt, scratch,
              Operand(GetInitialFastElementsKind()));
    __ Branch(&done, le, scratch,
              Operand(TERMINAL_FAST_ELEMENTS_KIND));
    __ Branch(&fail, lt, scratch,
              Operand(FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND));
    __ Branch(&done, le, scratch,
              Operand(LAST_EXTERNAL_ARRAY_ELEMENTS_KIND));
    __ bind(&fail);
    __ Abort("Check for fast or external elements failed.");
    __ bind(&done);
  }
}


void LCodeGen::DoLoadExternalArrayPointer(
    LLoadExternalArrayPointer* instr) {
  Register to_reg = ToRegister(instr->result());
  Register from_reg  = ToRegister(instr->object());
  __ lw(to_reg, FieldMemOperand(from_reg,
                                ExternalArray::kExternalPointerOffset));
}


void LCodeGen::DoAccessArgumentsAt(LAccessArgumentsAt* instr) {
  Register arguments = ToRegister(instr->arguments());
  Register length = ToRegister(instr->length());
  Register index = ToRegister(instr->index());
  Register result = ToRegister(instr->result());
  // There are two words between the frame pointer and the last argument.
  // Subtracting from length accounts for one of them, add one more.
  __ subu(length, length, index);
  __ Addu(length, length, Operand(1));
  __ sll(length, length, kPointerSizeLog2);
  __ Addu(at, arguments, Operand(length));
  __ lw(result, MemOperand(at, 0));
}


void LCodeGen::DoLoadKeyedFastElement(LLoadKeyedFastElement* instr) {
  Register elements = ToRegister(instr->elements());
  Register result = ToRegister(instr->result());
  Register scratch = scratch0();
  Register store_base = scratch;
  int offset = 0;

  if (instr->key()->IsConstantOperand()) {
    LConstantOperand* const_operand = LConstantOperand::cast(instr->key());
    offset = FixedArray::OffsetOfElementAt(ToInteger32(const_operand) +
                                           instr->additional_index());
    store_base = elements;
  } else {
    Register key = EmitLoadRegister(instr->key(), scratch);
    // Even though the HLoadKeyedFastElement instruction forces the input
    // representation for the key to be an integer, the input gets replaced
    // during bound check elimination with the index argument to the bounds
    // check, which can be tagged, so that case must be handled here, too.
    if (instr->hydrogen()->key()->representation().IsTagged()) {
      __ sll(scratch, key, kPointerSizeLog2 - kSmiTagSize);
      __ addu(scratch, elements, scratch);
    } else {
      __ sll(scratch, key, kPointerSizeLog2);
      __ addu(scratch, elements, scratch);
    }
    offset = FixedArray::OffsetOfElementAt(instr->additional_index());
  }
  __ lw(result, FieldMemOperand(store_base, offset));

  // Check for the hole value.
  if (instr->hydrogen()->RequiresHoleCheck()) {
    if (IsFastSmiElementsKind(instr->hydrogen()->elements_kind())) {
      __ And(scratch, result, Operand(kSmiTagMask));
      DeoptimizeIf(ne, instr->environment(), scratch, Operand(zero_reg));
    } else {
      __ LoadRoot(scratch, Heap::kTheHoleValueRootIndex);
      DeoptimizeIf(eq, instr->environment(), result, Operand(scratch));
    }
  }
}


void LCodeGen::DoLoadKeyedFastDoubleElement(
    LLoadKeyedFastDoubleElement* instr) {
  Register elements = ToRegister(instr->elements());
  bool key_is_constant = instr->key()->IsConstantOperand();
  Register key = no_reg;
  DoubleRegister result = ToDoubleRegister(instr->result());
  Register scratch = scratch0();

  int element_size_shift = ElementsKindToShiftSize(FAST_DOUBLE_ELEMENTS);
  int shift_size = (instr->hydrogen()->key()->representation().IsTagged())
      ? (element_size_shift - kSmiTagSize) : element_size_shift;
  int constant_key = 0;
  if (key_is_constant) {
    constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
    if (constant_key & 0xF0000000) {
      Abort("array index constant value too big.");
    }
  } else {
    key = ToRegister(instr->key());
  }

  if (key_is_constant) {
    __ Addu(elements, elements,
        Operand(((constant_key + instr->additional_index()) <<
                 element_size_shift) +
                FixedDoubleArray::kHeaderSize - kHeapObjectTag));
  } else {
    __ sll(scratch, key, shift_size);
    __ Addu(elements, elements, Operand(scratch));
    __ Addu(elements, elements,
            Operand((FixedDoubleArray::kHeaderSize - kHeapObjectTag) +
                    (instr->additional_index() << element_size_shift)));
  }

  if (instr->hydrogen()->RequiresHoleCheck()) {
    __ lw(scratch, MemOperand(elements, sizeof(kHoleNanLower32)));
    DeoptimizeIf(eq, instr->environment(), scratch, Operand(kHoleNanUpper32));
  }

  __ ldc1(result, MemOperand(elements));
}


MemOperand LCodeGen::PrepareKeyedOperand(Register key,
                                         Register base,
                                         bool key_is_constant,
                                         int constant_key,
                                         int element_size,
                                         int shift_size,
                                         int additional_index,
                                         int additional_offset) {
  if (additional_index != 0 && !key_is_constant) {
    additional_index *= 1 << (element_size - shift_size);
    __ Addu(scratch0(), key, Operand(additional_index));
  }

  if (key_is_constant) {
    return MemOperand(base,
                      (constant_key << element_size) + additional_offset);
  }

  if (additional_index == 0) {
    if (shift_size >= 0) {
      __ sll(scratch0(), key, shift_size);
      __ Addu(scratch0(), base, scratch0());
      return MemOperand(scratch0());
    } else {
      ASSERT_EQ(-1, shift_size);
      __ srl(scratch0(), key, 1);
      __ Addu(scratch0(), base, scratch0());
      return MemOperand(scratch0());
    }
  }

  if (shift_size >= 0) {
    __ sll(scratch0(), scratch0(), shift_size);
    __ Addu(scratch0(), base, scratch0());
    return MemOperand(scratch0());
  } else {
    ASSERT_EQ(-1, shift_size);
    __ srl(scratch0(), scratch0(), 1);
    __ Addu(scratch0(), base, scratch0());
    return MemOperand(scratch0());
  }
}


void LCodeGen::DoLoadKeyedSpecializedArrayElement(
    LLoadKeyedSpecializedArrayElement* instr) {
  Register external_pointer = ToRegister(instr->external_pointer());
  Register key = no_reg;
  ElementsKind elements_kind = instr->elements_kind();
  bool key_is_constant = instr->key()->IsConstantOperand();
  int constant_key = 0;
  if (key_is_constant) {
    constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
    if (constant_key & 0xF0000000) {
      Abort("array index constant value too big.");
    }
  } else {
    key = ToRegister(instr->key());
  }
  int element_size_shift = ElementsKindToShiftSize(elements_kind);
  int shift_size = (instr->hydrogen()->key()->representation().IsTagged())
      ? (element_size_shift - kSmiTagSize) : element_size_shift;
  int additional_offset = instr->additional_index() << element_size_shift;

  if (elements_kind == EXTERNAL_FLOAT_ELEMENTS ||
      elements_kind == EXTERNAL_DOUBLE_ELEMENTS) {
    FPURegister result = ToDoubleRegister(instr->result());
    if (key_is_constant) {
      __ Addu(scratch0(), external_pointer, constant_key << element_size_shift);
    } else {
      __ sll(scratch0(), key, shift_size);
      __ Addu(scratch0(), scratch0(), external_pointer);
    }

    if (elements_kind == EXTERNAL_FLOAT_ELEMENTS) {
      __ lwc1(result, MemOperand(scratch0(), additional_offset));
      __ cvt_d_s(result, result);
    } else  {  // i.e. elements_kind == EXTERNAL_DOUBLE_ELEMENTS
      __ ldc1(result, MemOperand(scratch0(), additional_offset));
    }
  } else {
    Register result = ToRegister(instr->result());
    MemOperand mem_operand = PrepareKeyedOperand(
        key, external_pointer, key_is_constant, constant_key,
        element_size_shift, shift_size,
        instr->additional_index(), additional_offset);
    switch (elements_kind) {
      case EXTERNAL_BYTE_ELEMENTS:
        __ lb(result, mem_operand);
        break;
      case EXTERNAL_PIXEL_ELEMENTS:
      case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
        __ lbu(result, mem_operand);
        break;
      case EXTERNAL_SHORT_ELEMENTS:
        __ lh(result, mem_operand);
        break;
      case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
        __ lhu(result, mem_operand);
        break;
      case EXTERNAL_INT_ELEMENTS:
        __ lw(result, mem_operand);
        break;
      case EXTERNAL_UNSIGNED_INT_ELEMENTS:
        __ lw(result, mem_operand);
        if (!instr->hydrogen()->CheckFlag(HInstruction::kUint32)) {
          DeoptimizeIf(Ugreater_equal, instr->environment(),
              result, Operand(0x80000000));
        }
        break;
      case EXTERNAL_FLOAT_ELEMENTS:
      case EXTERNAL_DOUBLE_ELEMENTS:
      case FAST_DOUBLE_ELEMENTS:
      case FAST_ELEMENTS:
      case FAST_SMI_ELEMENTS:
      case FAST_HOLEY_DOUBLE_ELEMENTS:
      case FAST_HOLEY_ELEMENTS:
      case FAST_HOLEY_SMI_ELEMENTS:
      case DICTIONARY_ELEMENTS:
      case NON_STRICT_ARGUMENTS_ELEMENTS:
        UNREACHABLE();
        break;
    }
  }
}


void LCodeGen::DoLoadKeyedGeneric(LLoadKeyedGeneric* instr) {
  ASSERT(ToRegister(instr->object()).is(a1));
  ASSERT(ToRegister(instr->key()).is(a0));

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


void LCodeGen::DoArgumentsElements(LArgumentsElements* instr) {
  Register scratch = scratch0();
  Register temp = scratch1();
  Register result = ToRegister(instr->result());

  if (instr->hydrogen()->from_inlined()) {
    __ Subu(result, sp, 2 * kPointerSize);
  } else {
    // Check if the calling frame is an arguments adaptor frame.
    Label done, adapted;
    __ lw(scratch, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
    __ lw(result, MemOperand(scratch, StandardFrameConstants::kContextOffset));
    __ Xor(temp, result, Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));

    // Result is the frame pointer for the frame if not adapted and for the real
    // frame below the adaptor frame if adapted.
    __ Movn(result, fp, temp);  // Move only if temp is not equal to zero (ne).
    __ Movz(result, scratch, temp);  // Move only if temp is equal to zero (eq).
  }
}


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

  Label done;

  // If no arguments adaptor frame the number of arguments is fixed.
  __ Addu(result, zero_reg, Operand(scope()->num_parameters()));
  __ Branch(&done, eq, fp, Operand(elem));

  // Arguments adaptor frame present. Get argument length from there.
  __ lw(result, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
  __ lw(result,
        MemOperand(result, ArgumentsAdaptorFrameConstants::kLengthOffset));
  __ SmiUntag(result);

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


void LCodeGen::DoWrapReceiver(LWrapReceiver* instr) {
  Register receiver = ToRegister(instr->receiver());
  Register function = ToRegister(instr->function());
  Register scratch = scratch0();

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

  // Do not transform the receiver to object for strict mode
  // functions.
  __ lw(scratch,
         FieldMemOperand(function, JSFunction::kSharedFunctionInfoOffset));
  __ lw(scratch,
         FieldMemOperand(scratch, SharedFunctionInfo::kCompilerHintsOffset));

  // Do not transform the receiver to object for builtins.
  int32_t strict_mode_function_mask =
                  1 <<  (SharedFunctionInfo::kStrictModeFunction + kSmiTagSize);
  int32_t native_mask = 1 << (SharedFunctionInfo::kNative + kSmiTagSize);
  __ And(scratch, scratch, Operand(strict_mode_function_mask | native_mask));
  __ Branch(&receiver_ok, ne, scratch, Operand(zero_reg));

  // Normal function. Replace undefined or null with global receiver.
  __ LoadRoot(scratch, Heap::kNullValueRootIndex);
  __ Branch(&global_object, eq, receiver, Operand(scratch));
  __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
  __ Branch(&global_object, eq, receiver, Operand(scratch));

  // Deoptimize if the receiver is not a JS object.
  __ And(scratch, receiver, Operand(kSmiTagMask));
  DeoptimizeIf(eq, instr->environment(), scratch, Operand(zero_reg));

  __ GetObjectType(receiver, scratch, scratch);
  DeoptimizeIf(lt, instr->environment(),
               scratch, Operand(FIRST_SPEC_OBJECT_TYPE));
  __ Branch(&receiver_ok);

  __ bind(&global_object);
  __ lw(receiver, GlobalObjectOperand());
  __ lw(receiver,
         FieldMemOperand(receiver, JSGlobalObject::kGlobalReceiverOffset));
  __ bind(&receiver_ok);
}

void LCodeGen::DoApplyArguments(LApplyArguments* instr) {
  Register receiver = ToRegister(instr->receiver());
  Register function = ToRegister(instr->function());
  Register length = ToRegister(instr->length());
  Register elements = ToRegister(instr->elements());
  Register scratch = scratch0();
  ASSERT(receiver.is(a0));  // Used for parameter count.
  ASSERT(function.is(a1));  // Required by InvokeFunction.
  ASSERT(ToRegister(instr->result()).is(v0));

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

  // Push the receiver and use the register to keep the original
  // number of arguments.
  __ push(receiver);
  __ Move(receiver, length);
  // The arguments are at a one pointer size offset from elements.
  __ Addu(elements, elements, Operand(1 * kPointerSize));

  // 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.
  __ Branch(USE_DELAY_SLOT, &invoke, eq, length, Operand(zero_reg));
  __ sll(scratch, length, 2);
  __ bind(&loop);
  __ Addu(scratch, elements, scratch);
  __ lw(scratch, MemOperand(scratch));
  __ push(scratch);
  __ Subu(length, length, Operand(1));
  __ Branch(USE_DELAY_SLOT, &loop, ne, length, Operand(zero_reg));
  __ sll(scratch, length, 2);

  __ bind(&invoke);
  ASSERT(instr->HasPointerMap());
  LPointerMap* pointers = instr->pointer_map();
  RecordPosition(pointers->position());
  SafepointGenerator safepoint_generator(
      this, pointers, Safepoint::kLazyDeopt);
  // The number of arguments is stored in receiver which is a0, as expected
  // by InvokeFunction.
  ParameterCount actual(receiver);
  __ InvokeFunction(function, actual, CALL_FUNCTION,
                    safepoint_generator, CALL_AS_METHOD);
  __ lw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
}


void LCodeGen::DoPushArgument(LPushArgument* instr) {
  LOperand* argument = instr->value();
  if (argument->IsDoubleRegister() || argument->IsDoubleStackSlot()) {
    Abort("DoPushArgument not implemented for double type.");
  } else {
    Register argument_reg = EmitLoadRegister(argument, at);
    __ push(argument_reg);
  }
}


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


void LCodeGen::DoThisFunction(LThisFunction* instr) {
  Register result = ToRegister(instr->result());
  __ lw(result, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
}


void LCodeGen::DoContext(LContext* instr) {
  Register result = ToRegister(instr->result());
  __ mov(result, cp);
}


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


void LCodeGen::DoDeclareGlobals(LDeclareGlobals* instr) {
  __ LoadHeapObject(scratch0(), instr->hydrogen()->pairs());
  __ li(scratch1(), Operand(Smi::FromInt(instr->hydrogen()->flags())));
  // The context is the first argument.
  __ Push(cp, scratch0(), scratch1());
  CallRuntime(Runtime::kDeclareGlobals, 3, instr);
}


void LCodeGen::DoGlobalObject(LGlobalObject* instr) {
  Register result = ToRegister(instr->result());
  __ lw(result, ContextOperand(cp, Context::GLOBAL_OBJECT_INDEX));
}


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


void LCodeGen::CallKnownFunction(Handle<JSFunction> function,
                                 int arity,
                                 LInstruction* instr,
                                 CallKind call_kind,
                                 A1State a1_state) {
  bool can_invoke_directly = !function->NeedsArgumentsAdaption() ||
      function->shared()->formal_parameter_count() == arity;

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

  if (can_invoke_directly) {
    if (a1_state == A1_UNINITIALIZED) {
      __ LoadHeapObject(a1, function);
    }

    // Change context.
    __ lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset));

    // Set r0 to arguments count if adaption is not needed. Assumes that r0
    // is available to write to at this point.
    if (!function->NeedsArgumentsAdaption()) {
      __ li(a0, Operand(arity));
    }

    // Invoke function.
    __ SetCallKind(t1, call_kind);
    __ lw(at, FieldMemOperand(a1, JSFunction::kCodeEntryOffset));
    __ Call(at);

    // Set up deoptimization.
    RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
  } else {
    SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
    ParameterCount count(arity);
    __ InvokeFunction(function, count, CALL_FUNCTION, generator, call_kind);
  }

  // Restore context.
  __ lw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
}


void LCodeGen::DoCallConstantFunction(LCallConstantFunction* instr) {
  ASSERT(ToRegister(instr->result()).is(v0));
  __ mov(a0, v0);
  CallKnownFunction(instr->function(),
                    instr->arity(),
                    instr,
                    CALL_AS_METHOD,
                    A1_UNINITIALIZED);
}


void LCodeGen::DoDeferredMathAbsTaggedHeapNumber(LUnaryMathOperation* instr) {
  Register input = ToRegister(instr->value());
  Register result = ToRegister(instr->result());
  Register scratch = scratch0();

  // Deoptimize if not a heap number.
  __ lw(scratch, FieldMemOperand(input, HeapObject::kMapOffset));
  __ LoadRoot(at, Heap::kHeapNumberMapRootIndex);
  DeoptimizeIf(ne, instr->environment(), scratch, Operand(at));

  Label done;
  Register exponent = scratch0();
  scratch = no_reg;
  __ lw(exponent, FieldMemOperand(input, HeapNumber::kExponentOffset));
  // Check the sign of the argument. If the argument is positive, just
  // return it.
  __ Move(result, input);
  __ And(at, exponent, Operand(HeapNumber::kSignMask));
  __ Branch(&done, eq, at, Operand(zero_reg));

  // Input is negative. Reverse its sign.
  // Preserve the value of all registers.
  {
    PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);

    // Registers were saved at the safepoint, so we can use
    // many scratch registers.
    Register tmp1 = input.is(a1) ? a0 : a1;
    Register tmp2 = input.is(a2) ? a0 : a2;
    Register tmp3 = input.is(a3) ? a0 : a3;
    Register tmp4 = input.is(t0) ? a0 : t0;

    // exponent: floating point exponent value.

    Label allocated, slow;
    __ LoadRoot(tmp4, Heap::kHeapNumberMapRootIndex);
    __ AllocateHeapNumber(tmp1, tmp2, tmp3, tmp4, &slow);
    __ Branch(&allocated);

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

    CallRuntimeFromDeferred(Runtime::kAllocateHeapNumber, 0, instr);
    // Set the pointer to the new heap number in tmp.
    if (!tmp1.is(v0))
      __ mov(tmp1, v0);
    // Restore input_reg after call to runtime.
    __ LoadFromSafepointRegisterSlot(input, input);
    __ lw(exponent, FieldMemOperand(input, HeapNumber::kExponentOffset));

    __ bind(&allocated);
    // exponent: floating point exponent value.
    // tmp1: allocated heap number.
    __ And(exponent, exponent, Operand(~HeapNumber::kSignMask));
    __ sw(exponent, FieldMemOperand(tmp1, HeapNumber::kExponentOffset));
    __ lw(tmp2, FieldMemOperand(input, HeapNumber::kMantissaOffset));
    __ sw(tmp2, FieldMemOperand(tmp1, HeapNumber::kMantissaOffset));

    __ StoreToSafepointRegisterSlot(tmp1, result);
  }

  __ bind(&done);
}


void LCodeGen::EmitIntegerMathAbs(LUnaryMathOperation* instr) {
  Register input = ToRegister(instr->value());
  Register result = ToRegister(instr->result());
  Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_);
  Label done;
  __ Branch(USE_DELAY_SLOT, &done, ge, input, Operand(zero_reg));
  __ mov(result, input);
  ASSERT_EQ(2, masm()->InstructionsGeneratedSince(&done));
  __ subu(result, zero_reg, input);
  // Overflow if result is still negative, i.e. 0x80000000.
  DeoptimizeIf(lt, instr->environment(), result, Operand(zero_reg));
  __ bind(&done);
}


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

  Representation r = instr->hydrogen()->value()->representation();
  if (r.IsDouble()) {
    FPURegister input = ToDoubleRegister(instr->value());
    FPURegister result = ToDoubleRegister(instr->result());
    __ abs_d(result, input);
  } else if (r.IsInteger32()) {
    EmitIntegerMathAbs(instr);
  } else {
    // Representation is tagged.
    DeferredMathAbsTaggedHeapNumber* deferred =
        new(zone()) DeferredMathAbsTaggedHeapNumber(this, instr);
    Register input = ToRegister(instr->value());
    // Smi check.
    __ JumpIfNotSmi(input, deferred->entry());
    // If smi, handle it directly.
    EmitIntegerMathAbs(instr);
    __ bind(deferred->exit());
  }
}


void LCodeGen::DoMathFloor(LUnaryMathOperation* instr) {
  DoubleRegister input = ToDoubleRegister(instr->value());
  Register result = ToRegister(instr->result());
  FPURegister single_scratch = double_scratch0().low();
  Register scratch1 = scratch0();
  Register except_flag = ToRegister(instr->temp());

  __ EmitFPUTruncate(kRoundToMinusInf,
                     single_scratch,
                     input,
                     scratch1,
                     except_flag);

  // Deopt if the operation did not succeed.
  DeoptimizeIf(ne, instr->environment(), except_flag, Operand(zero_reg));

  // Load the result.
  __ mfc1(result, single_scratch);

  if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
    // Test for -0.
    Label done;
    __ Branch(&done, ne, result, Operand(zero_reg));
    __ mfc1(scratch1, input.high());
    __ And(scratch1, scratch1, Operand(HeapNumber::kSignMask));
    DeoptimizeIf(ne, instr->environment(), scratch1, Operand(zero_reg));
    __ bind(&done);
  }
}


void LCodeGen::DoMathRound(LUnaryMathOperation* instr) {
  DoubleRegister input = ToDoubleRegister(instr->value());
  Register result = ToRegister(instr->result());
  Register scratch = scratch0();
  Label done, check_sign_on_zero;

  // Extract exponent bits.
  __ mfc1(result, input.high());
  __ Ext(scratch,
         result,
         HeapNumber::kExponentShift,
         HeapNumber::kExponentBits);

  // If the number is in ]-0.5, +0.5[, the result is +/- 0.
  Label skip1;
  __ Branch(&skip1, gt, scratch, Operand(HeapNumber::kExponentBias - 2));
  __ mov(result, zero_reg);
  if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
    __ Branch(&check_sign_on_zero);
  } else {
    __ Branch(&done);
  }
  __ bind(&skip1);

  // The following conversion will not work with numbers
  // outside of ]-2^32, 2^32[.
  DeoptimizeIf(ge, instr->environment(), scratch,
               Operand(HeapNumber::kExponentBias + 32));

  // Save the original sign for later comparison.
  __ And(scratch, result, Operand(HeapNumber::kSignMask));

  __ Move(double_scratch0(), 0.5);
  __ add_d(double_scratch0(), input, double_scratch0());

  // Check sign of the result: if the sign changed, the input
  // value was in ]0.5, 0[ and the result should be -0.
  __ mfc1(result, double_scratch0().high());
  __ Xor(result, result, Operand(scratch));
  if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
    // ARM uses 'mi' here, which is 'lt'
    DeoptimizeIf(lt, instr->environment(), result,
                 Operand(zero_reg));
  } else {
    Label skip2;
    // ARM uses 'mi' here, which is 'lt'
    // Negating it results in 'ge'
    __ Branch(&skip2, ge, result, Operand(zero_reg));
    __ mov(result, zero_reg);
    __ Branch(&done);
    __ bind(&skip2);
  }

  Register except_flag = scratch;

  __ EmitFPUTruncate(kRoundToMinusInf,
                     double_scratch0().low(),
                     double_scratch0(),
                     result,
                     except_flag);

  DeoptimizeIf(ne, instr->environment(), except_flag, Operand(zero_reg));

  __ mfc1(result, double_scratch0().low());

  if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
    // Test for -0.
    __ Branch(&done, ne, result, Operand(zero_reg));
    __ bind(&check_sign_on_zero);
    __ mfc1(scratch, input.high());
    __ And(scratch, scratch, Operand(HeapNumber::kSignMask));
    DeoptimizeIf(ne, instr->environment(), scratch, Operand(zero_reg));
  }
  __ bind(&done);
}


void LCodeGen::DoMathSqrt(LUnaryMathOperation* instr) {
  DoubleRegister input = ToDoubleRegister(instr->value());
  DoubleRegister result = ToDoubleRegister(instr->result());
  __ sqrt_d(result, input);
}


void LCodeGen::DoMathPowHalf(LUnaryMathOperation* instr) {
  DoubleRegister input = ToDoubleRegister(instr->value());
  DoubleRegister result = ToDoubleRegister(instr->result());
  DoubleRegister temp = ToDoubleRegister(instr->temp());

  ASSERT(!input.is(result));

  // Note that according to ECMA-262 15.8.2.13:
  // Math.pow(-Infinity, 0.5) == Infinity
  // Math.sqrt(-Infinity) == NaN
  Label done;
  __ Move(temp, -V8_INFINITY);
  __ BranchF(USE_DELAY_SLOT, &done, NULL, eq, temp, input);
  // Set up Infinity in the delay slot.
  // result is overwritten if the branch is not taken.
  __ neg_d(result, temp);

  // Add +0 to convert -0 to +0.
  __ add_d(result, input, kDoubleRegZero);
  __ sqrt_d(result, result);
  __ bind(&done);
}


void LCodeGen::DoPower(LPower* instr) {
  Representation exponent_type = instr->hydrogen()->right()->representation();
  // Having marked this as a call, we can use any registers.
  // Just make sure that the input/output registers are the expected ones.
  ASSERT(!instr->right()->IsDoubleRegister() ||
         ToDoubleRegister(instr->right()).is(f4));
  ASSERT(!instr->right()->IsRegister() ||
         ToRegister(instr->right()).is(a2));
  ASSERT(ToDoubleRegister(instr->left()).is(f2));
  ASSERT(ToDoubleRegister(instr->result()).is(f0));

  if (exponent_type.IsTagged()) {
    Label no_deopt;
    __ JumpIfSmi(a2, &no_deopt);
    __ lw(t3, FieldMemOperand(a2, HeapObject::kMapOffset));
    DeoptimizeIf(ne, instr->environment(), t3, Operand(at));
    __ bind(&no_deopt);
    MathPowStub stub(MathPowStub::TAGGED);
    __ CallStub(&stub);
  } else if (exponent_type.IsInteger32()) {
    MathPowStub stub(MathPowStub::INTEGER);
    __ CallStub(&stub);
  } else {
    ASSERT(exponent_type.IsDouble());
    MathPowStub stub(MathPowStub::DOUBLE);
    __ CallStub(&stub);
  }
}


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

  DeferredDoRandom* deferred = new(zone()) DeferredDoRandom(this, instr);
  // Having marked this instruction as a call we can use any
  // registers.
  ASSERT(ToDoubleRegister(instr->result()).is(f0));
  ASSERT(ToRegister(instr->global_object()).is(a0));

  static const int kSeedSize = sizeof(uint32_t);
  STATIC_ASSERT(kPointerSize == kSeedSize);

  __ lw(a0, FieldMemOperand(a0, GlobalObject::kNativeContextOffset));
  static const int kRandomSeedOffset =
      FixedArray::kHeaderSize + Context::RANDOM_SEED_INDEX * kPointerSize;
  __ lw(a2, FieldMemOperand(a0, kRandomSeedOffset));
  // a2: FixedArray of the native context's random seeds

  // Load state[0].
  __ lw(a1, FieldMemOperand(a2, ByteArray::kHeaderSize));
  __ Branch(deferred->entry(), eq, a1, Operand(zero_reg));
  // Load state[1].
  __ lw(a0, FieldMemOperand(a2, ByteArray::kHeaderSize + kSeedSize));
  // a1: state[0].
  // a0: state[1].

  // state[0] = 18273 * (state[0] & 0xFFFF) + (state[0] >> 16)
  __ And(a3, a1, Operand(0xFFFF));
  __ li(t0, Operand(18273));
  __ Mul(a3, a3, t0);
  __ srl(a1, a1, 16);
  __ Addu(a1, a3, a1);
  // Save state[0].
  __ sw(a1, FieldMemOperand(a2, ByteArray::kHeaderSize));

  // state[1] = 36969 * (state[1] & 0xFFFF) + (state[1] >> 16)
  __ And(a3, a0, Operand(0xFFFF));
  __ li(t0, Operand(36969));
  __ Mul(a3, a3, t0);
  __ srl(a0, a0, 16),
  __ Addu(a0, a3, a0);
  // Save state[1].
  __ sw(a0, FieldMemOperand(a2, ByteArray::kHeaderSize + kSeedSize));

  // Random bit pattern = (state[0] << 14) + (state[1] & 0x3FFFF)
  __ And(a0, a0, Operand(0x3FFFF));
  __ sll(a1, a1, 14);
  __ Addu(v0, a0, a1);

  __ bind(deferred->exit());

  // 0x41300000 is the top half of 1.0 x 2^20 as a double.
  __ li(a2, Operand(0x41300000));
  // Move 0x41300000xxxxxxxx (x = random bits in v0) to FPU.
  __ Move(f12, v0, a2);
  // Move 0x4130000000000000 to FPU.
  __ Move(f14, zero_reg, a2);
  // Subtract to get the result.
  __ sub_d(f0, f12, f14);
}

void LCodeGen::DoDeferredRandom(LRandom* instr) {
  __ PrepareCallCFunction(1, scratch0());
  __ CallCFunction(ExternalReference::random_uint32_function(isolate()), 1);
  // Return value is in v0.
}


void LCodeGen::DoMathLog(LUnaryMathOperation* instr) {
  ASSERT(ToDoubleRegister(instr->result()).is(f4));
  TranscendentalCacheStub stub(TranscendentalCache::LOG,
                               TranscendentalCacheStub::UNTAGGED);
  CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
}


void LCodeGen::DoMathTan(LUnaryMathOperation* instr) {
  ASSERT(ToDoubleRegister(instr->result()).is(f4));
  TranscendentalCacheStub stub(TranscendentalCache::TAN,
                               TranscendentalCacheStub::UNTAGGED);
  CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
}


void LCodeGen::DoMathCos(LUnaryMathOperation* instr) {
  ASSERT(ToDoubleRegister(instr->result()).is(f4));
  TranscendentalCacheStub stub(TranscendentalCache::COS,
                               TranscendentalCacheStub::UNTAGGED);
  CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
}


void LCodeGen::DoMathSin(LUnaryMathOperation* instr) {
  ASSERT(ToDoubleRegister(instr->result()).is(f4));
  TranscendentalCacheStub stub(TranscendentalCache::SIN,
                               TranscendentalCacheStub::UNTAGGED);
  CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
}


void LCodeGen::DoUnaryMathOperation(LUnaryMathOperation* instr) {
  switch (instr->op()) {
    case kMathAbs:
      DoMathAbs(instr);
      break;
    case kMathFloor:
      DoMathFloor(instr);
      break;
    case kMathRound:
      DoMathRound(instr);
      break;
    case kMathSqrt:
      DoMathSqrt(instr);
      break;
    case kMathPowHalf:
      DoMathPowHalf(instr);
      break;
    case kMathCos:
      DoMathCos(instr);
      break;
    case kMathSin:
      DoMathSin(instr);
      break;
    case kMathTan:
      DoMathTan(instr);
      break;
    case kMathLog:
      DoMathLog(instr);
      break;
    default:
      Abort("Unimplemented type of LUnaryMathOperation.");
      UNREACHABLE();
  }
}


void LCodeGen::DoInvokeFunction(LInvokeFunction* instr) {
  ASSERT(ToRegister(instr->function()).is(a1));
  ASSERT(instr->HasPointerMap());

  if (instr->known_function().is_null()) {
    LPointerMap* pointers = instr->pointer_map();
    RecordPosition(pointers->position());
    SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
    ParameterCount count(instr->arity());
    __ InvokeFunction(a1, count, CALL_FUNCTION, generator, CALL_AS_METHOD);
    __ lw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
  } else {
    CallKnownFunction(instr->known_function(),
                      instr->arity(),
                      instr,
                      CALL_AS_METHOD,
                      A1_CONTAINS_TARGET);
  }
}


void LCodeGen::DoCallKeyed(LCallKeyed* instr) {
  ASSERT(ToRegister(instr->result()).is(v0));

  int arity = instr->arity();
  Handle<Code> ic =
      isolate()->stub_cache()->ComputeKeyedCallInitialize(arity);
  CallCode(ic, RelocInfo::CODE_TARGET, instr);
  __ lw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
}


void LCodeGen::DoCallNamed(LCallNamed* instr) {
  ASSERT(ToRegister(instr->result()).is(v0));

  int arity = instr->arity();
  RelocInfo::Mode mode = RelocInfo::CODE_TARGET;
  Handle<Code> ic =
      isolate()->stub_cache()->ComputeCallInitialize(arity, mode);
  __ li(a2, Operand(instr->name()));
  CallCode(ic, mode, instr);
  // Restore context register.
  __ lw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
}


void LCodeGen::DoCallFunction(LCallFunction* instr) {
  ASSERT(ToRegister(instr->function()).is(a1));
  ASSERT(ToRegister(instr->result()).is(v0));

  int arity = instr->arity();
  CallFunctionStub stub(arity, NO_CALL_FUNCTION_FLAGS);
  CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
  __ lw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
}


void LCodeGen::DoCallGlobal(LCallGlobal* instr) {
  ASSERT(ToRegister(instr->result()).is(v0));

  int arity = instr->arity();
  RelocInfo::Mode mode = RelocInfo::CODE_TARGET_CONTEXT;
  Handle<Code> ic =
      isolate()->stub_cache()->ComputeCallInitialize(arity, mode);
  __ li(a2, Operand(instr->name()));
  CallCode(ic, mode, instr);
  __ lw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
}


void LCodeGen::DoCallKnownGlobal(LCallKnownGlobal* instr) {
  ASSERT(ToRegister(instr->result()).is(v0));
  CallKnownFunction(instr->target(),
                    instr->arity(),
                    instr,
                    CALL_AS_FUNCTION,
                    A1_UNINITIALIZED);
}


void LCodeGen::DoCallNew(LCallNew* instr) {
  ASSERT(ToRegister(instr->constructor()).is(a1));
  ASSERT(ToRegister(instr->result()).is(v0));

  CallConstructStub stub(NO_CALL_FUNCTION_FLAGS);
  __ li(a0, Operand(instr->arity()));
  CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
}


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


void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
  Register object = ToRegister(instr->object());
  Register value = ToRegister(instr->value());
  Register scratch = scratch0();
  int offset = instr->offset();

  ASSERT(!object.is(value));

  if (!instr->transition().is_null()) {
    __ li(scratch, Operand(instr->transition()));
    __ sw(scratch, FieldMemOperand(object, HeapObject::kMapOffset));
    if (instr->hydrogen()->NeedsWriteBarrierForMap()) {
      Register temp = ToRegister(instr->temp());
      // Update the write barrier for the map field.
      __ RecordWriteField(object,
                          HeapObject::kMapOffset,
                          scratch,
                          temp,
                          kRAHasBeenSaved,
                          kSaveFPRegs,
                          OMIT_REMEMBERED_SET,
                          OMIT_SMI_CHECK);
    }
  }

  // Do the store.
  HType type = instr->hydrogen()->value()->type();
  SmiCheck check_needed =
      type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
  if (instr->is_in_object()) {
    __ sw(value, FieldMemOperand(object, offset));
    if (instr->hydrogen()->NeedsWriteBarrier()) {
      // Update the write barrier for the object for in-object properties.
      __ RecordWriteField(object,
                          offset,
                          value,
                          scratch,
                          kRAHasBeenSaved,
                          kSaveFPRegs,
                          EMIT_REMEMBERED_SET,
                          check_needed);
    }
  } else {
    __ lw(scratch, FieldMemOperand(object, JSObject::kPropertiesOffset));
    __ sw(value, FieldMemOperand(scratch, offset));
    if (instr->hydrogen()->NeedsWriteBarrier()) {
      // Update the write barrier for the properties array.
      // object is used as a scratch register.
      __ RecordWriteField(scratch,
                          offset,
                          value,
                          object,
                          kRAHasBeenSaved,
                          kSaveFPRegs,
                          EMIT_REMEMBERED_SET,
                          check_needed);
    }
  }
}


void LCodeGen::DoStoreNamedGeneric(LStoreNamedGeneric* instr) {
  ASSERT(ToRegister(instr->object()).is(a1));
  ASSERT(ToRegister(instr->value()).is(a0));

  // Name is always in a2.
  __ li(a2, Operand(instr->name()));
  Handle<Code> ic = (instr->strict_mode_flag() == kStrictMode)
      ? isolate()->builtins()->StoreIC_Initialize_Strict()
      : isolate()->builtins()->StoreIC_Initialize();
  CallCode(ic, RelocInfo::CODE_TARGET, instr);
}


void LCodeGen::DeoptIfTaggedButNotSmi(LEnvironment* environment,
                                      HValue* value,
                                      LOperand* operand) {
  if (value->representation().IsTagged() && !value->type().IsSmi()) {
    if (operand->IsRegister()) {
      __ And(at, ToRegister(operand), Operand(kSmiTagMask));
      DeoptimizeIf(ne, environment, at, Operand(zero_reg));
    } else {
      __ li(at, ToOperand(operand));
      __ And(at, at, Operand(kSmiTagMask));
      DeoptimizeIf(ne, environment, at, Operand(zero_reg));
    }
  }
}


void LCodeGen::DoBoundsCheck(LBoundsCheck* instr) {
  DeoptIfTaggedButNotSmi(instr->environment(),
                         instr->hydrogen()->length(),
                         instr->length());
  DeoptIfTaggedButNotSmi(instr->environment(),
                         instr->hydrogen()->index(),
                         instr->index());
  if (instr->index()->IsConstantOperand()) {
    int constant_index =
        ToInteger32(LConstantOperand::cast(instr->index()));
    if (instr->hydrogen()->length()->representation().IsTagged()) {
      __ li(at, Operand(Smi::FromInt(constant_index)));
    } else {
      __ li(at, Operand(constant_index));
    }
    DeoptimizeIf(hs,
                 instr->environment(),
                 at,
                 Operand(ToRegister(instr->length())));
  } else {
    DeoptimizeIf(hs,
                 instr->environment(),
                 ToRegister(instr->index()),
                 Operand(ToRegister(instr->length())));
  }
}


void LCodeGen::DoStoreKeyedFastElement(LStoreKeyedFastElement* instr) {
  Register value = ToRegister(instr->value());
  Register elements = ToRegister(instr->object());
  Register key = instr->key()->IsRegister() ? ToRegister(instr->key()) : no_reg;
  Register scratch = scratch0();
  Register store_base = scratch;
  int offset = 0;

  // Do the store.
  if (instr->key()->IsConstantOperand()) {
    ASSERT(!instr->hydrogen()->NeedsWriteBarrier());
    LConstantOperand* const_operand = LConstantOperand::cast(instr->key());
    offset = FixedArray::OffsetOfElementAt(ToInteger32(const_operand) +
                                           instr->additional_index());
    store_base = elements;
  } else {
    // Even though the HLoadKeyedFastElement instruction forces the input
    // representation for the key to be an integer, the input gets replaced
    // during bound check elimination with the index argument to the bounds
    // check, which can be tagged, so that case must be handled here, too.
    if (instr->hydrogen()->key()->representation().IsTagged()) {
      __ sll(scratch, key, kPointerSizeLog2 - kSmiTagSize);
      __ addu(scratch, elements, scratch);
    } else {
      __ sll(scratch, key, kPointerSizeLog2);
      __ addu(scratch, elements, scratch);
    }
    offset = FixedArray::OffsetOfElementAt(instr->additional_index());
  }
  __ sw(value, FieldMemOperand(store_base, offset));

  if (instr->hydrogen()->NeedsWriteBarrier()) {
    HType type = instr->hydrogen()->value()->type();
    SmiCheck check_needed =
        type.IsHeapObject() ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
    // Compute address of modified element and store it into key register.
    __ Addu(key, store_base, Operand(offset - kHeapObjectTag));
    __ RecordWrite(elements,
                   key,
                   value,
                   kRAHasBeenSaved,
                   kSaveFPRegs,
                   EMIT_REMEMBERED_SET,
                   check_needed);
  }
}


void LCodeGen::DoStoreKeyedFastDoubleElement(
    LStoreKeyedFastDoubleElement* instr) {
  DoubleRegister value = ToDoubleRegister(instr->value());
  Register elements = ToRegister(instr->elements());
  Register key = no_reg;
  Register scratch = scratch0();
  bool key_is_constant = instr->key()->IsConstantOperand();
  int constant_key = 0;
  Label not_nan;

  // Calculate the effective address of the slot in the array to store the
  // double value.
  if (key_is_constant) {
    constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
    if (constant_key & 0xF0000000) {
      Abort("array index constant value too big.");
    }
  } else {
    key = ToRegister(instr->key());
  }
  int element_size_shift = ElementsKindToShiftSize(FAST_DOUBLE_ELEMENTS);
  int shift_size = (instr->hydrogen()->key()->representation().IsTagged())
      ? (element_size_shift - kSmiTagSize) : element_size_shift;
  if (key_is_constant) {
    __ Addu(scratch, elements, Operand((constant_key << element_size_shift) +
            FixedDoubleArray::kHeaderSize - kHeapObjectTag));
  } else {
    __ sll(scratch, key, shift_size);
    __ Addu(scratch, elements, Operand(scratch));
    __ Addu(scratch, scratch,
            Operand(FixedDoubleArray::kHeaderSize - kHeapObjectTag));
  }

  if (instr->NeedsCanonicalization()) {
    Label is_nan;
    // Check for NaN. All NaNs must be canonicalized.
    __ BranchF(NULL, &is_nan, eq, value, value);
    __ Branch(&not_nan);

    // Only load canonical NaN if the comparison above set the overflow.
    __ bind(&is_nan);
    __ Move(value, FixedDoubleArray::canonical_not_the_hole_nan_as_double());
  }

  __ bind(&not_nan);
  __ sdc1(value, MemOperand(scratch, instr->additional_index() <<
      element_size_shift));
}


void LCodeGen::DoStoreKeyedSpecializedArrayElement(
    LStoreKeyedSpecializedArrayElement* instr) {

  Register external_pointer = ToRegister(instr->external_pointer());
  Register key = no_reg;
  ElementsKind elements_kind = instr->elements_kind();
  bool key_is_constant = instr->key()->IsConstantOperand();
  int constant_key = 0;
  if (key_is_constant) {
    constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
    if (constant_key & 0xF0000000) {
      Abort("array index constant value too big.");
    }
  } else {
    key = ToRegister(instr->key());
  }
  int element_size_shift = ElementsKindToShiftSize(elements_kind);
  int shift_size = (instr->hydrogen()->key()->representation().IsTagged())
      ? (element_size_shift - kSmiTagSize) : element_size_shift;
  int additional_offset = instr->additional_index() << element_size_shift;

  if (elements_kind == EXTERNAL_FLOAT_ELEMENTS ||
      elements_kind == EXTERNAL_DOUBLE_ELEMENTS) {
    FPURegister value(ToDoubleRegister(instr->value()));
    if (key_is_constant) {
      __ Addu(scratch0(), external_pointer, constant_key <<
          element_size_shift);
    } else {
      __ sll(scratch0(), key, shift_size);
      __ Addu(scratch0(), scratch0(), external_pointer);
    }

    if (elements_kind == EXTERNAL_FLOAT_ELEMENTS) {
      __ cvt_s_d(double_scratch0(), value);
      __ swc1(double_scratch0(), MemOperand(scratch0(), additional_offset));
    } else {  // i.e. elements_kind == EXTERNAL_DOUBLE_ELEMENTS
      __ sdc1(value, MemOperand(scratch0(), additional_offset));
    }
  } else {
    Register value(ToRegister(instr->value()));
    MemOperand mem_operand = PrepareKeyedOperand(
        key, external_pointer, key_is_constant, constant_key,
        element_size_shift, shift_size,
        instr->additional_index(), additional_offset);
    switch (elements_kind) {
      case EXTERNAL_PIXEL_ELEMENTS:
      case EXTERNAL_BYTE_ELEMENTS:
      case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
        __ sb(value, mem_operand);
        break;
      case EXTERNAL_SHORT_ELEMENTS:
      case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
        __ sh(value, mem_operand);
        break;
      case EXTERNAL_INT_ELEMENTS:
      case EXTERNAL_UNSIGNED_INT_ELEMENTS:
        __ sw(value, mem_operand);
        break;
      case EXTERNAL_FLOAT_ELEMENTS:
      case EXTERNAL_DOUBLE_ELEMENTS:
      case FAST_DOUBLE_ELEMENTS:
      case FAST_ELEMENTS:
      case FAST_SMI_ELEMENTS:
      case FAST_HOLEY_DOUBLE_ELEMENTS:
      case FAST_HOLEY_ELEMENTS:
      case FAST_HOLEY_SMI_ELEMENTS:
      case DICTIONARY_ELEMENTS:
      case NON_STRICT_ARGUMENTS_ELEMENTS:
        UNREACHABLE();
        break;
    }
  }
}

void LCodeGen::DoStoreKeyedGeneric(LStoreKeyedGeneric* instr) {
  ASSERT(ToRegister(instr->object()).is(a2));
  ASSERT(ToRegister(instr->key()).is(a1));
  ASSERT(ToRegister(instr->value()).is(a0));

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


void LCodeGen::DoTransitionElementsKind(LTransitionElementsKind* instr) {
  Register object_reg = ToRegister(instr->object());
  Register new_map_reg = ToRegister(instr->new_map_temp());
  Register scratch = scratch0();

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

  __ mov(ToRegister(instr->result()), object_reg);

  Label not_applicable;
  __ lw(scratch, FieldMemOperand(object_reg, HeapObject::kMapOffset));
  __ Branch(&not_applicable, ne, scratch, Operand(from_map));

  __ li(new_map_reg, Operand(to_map));
  if (IsFastSmiElementsKind(from_kind) && IsFastObjectElementsKind(to_kind)) {
    __ sw(new_map_reg, FieldMemOperand(object_reg, HeapObject::kMapOffset));
    // Write barrier.
    __ RecordWriteField(object_reg, HeapObject::kMapOffset, new_map_reg,
                        scratch, kRAHasBeenSaved, kDontSaveFPRegs);
  } else if (IsFastSmiElementsKind(from_kind) &&
             IsFastDoubleElementsKind(to_kind)) {
    Register fixed_object_reg = ToRegister(instr->temp());
    ASSERT(fixed_object_reg.is(a2));
    ASSERT(new_map_reg.is(a3));
    __ mov(fixed_object_reg, object_reg);
    CallCode(isolate()->builtins()->TransitionElementsSmiToDouble(),
             RelocInfo::CODE_TARGET, instr);
  } else if (IsFastDoubleElementsKind(from_kind) &&
             IsFastObjectElementsKind(to_kind)) {
    Register fixed_object_reg = ToRegister(instr->temp());
    ASSERT(fixed_object_reg.is(a2));
    ASSERT(new_map_reg.is(a3));
    __ mov(fixed_object_reg, object_reg);
    CallCode(isolate()->builtins()->TransitionElementsDoubleToObject(),
             RelocInfo::CODE_TARGET, instr);
  } else {
    UNREACHABLE();
  }
  __ bind(&not_applicable);
}


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


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

  DeferredStringCharCodeAt* deferred =
      new(zone()) DeferredStringCharCodeAt(this, instr);
  StringCharLoadGenerator::Generate(masm(),
                                    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());
  Register scratch = scratch0();

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

  PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
  __ push(string);
  // Push the index as a smi. This is safe because of the checks in
  // DoStringCharCodeAt above.
  if (instr->index()->IsConstantOperand()) {
    int const_index = ToInteger32(LConstantOperand::cast(instr->index()));
    __ Addu(scratch, zero_reg, Operand(Smi::FromInt(const_index)));
    __ push(scratch);
  } else {
    Register index = ToRegister(instr->index());
    __ SmiTag(index);
    __ push(index);
  }
  CallRuntimeFromDeferred(Runtime::kStringCharCodeAt, 2, instr);
  __ AssertSmi(v0);
  __ SmiUntag(v0);
  __ StoreToSafepointRegisterSlot(v0, result);
}


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

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

  ASSERT(instr->hydrogen()->value()->representation().IsInteger32());
  Register char_code = ToRegister(instr->char_code());
  Register result = ToRegister(instr->result());
  Register scratch = scratch0();
  ASSERT(!char_code.is(result));

  __ Branch(deferred->entry(), hi,
            char_code, Operand(String::kMaxAsciiCharCode));
  __ LoadRoot(result, Heap::kSingleCharacterStringCacheRootIndex);
  __ sll(scratch, char_code, kPointerSizeLog2);
  __ Addu(result, result, scratch);
  __ lw(result, FieldMemOperand(result, FixedArray::kHeaderSize));
  __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
  __ Branch(deferred->entry(), eq, result, Operand(scratch));
  __ 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.
  __ mov(result, zero_reg);

  PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
  __ SmiTag(char_code);
  __ push(char_code);
  CallRuntimeFromDeferred(Runtime::kCharFromCode, 1, instr);
  __ StoreToSafepointRegisterSlot(v0, result);
}


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


void LCodeGen::DoInteger32ToDouble(LInteger32ToDouble* instr) {
  LOperand* input = instr->value();
  ASSERT(input->IsRegister() || input->IsStackSlot());
  LOperand* output = instr->result();
  ASSERT(output->IsDoubleRegister());
  FPURegister single_scratch = double_scratch0().low();
  if (input->IsStackSlot()) {
    Register scratch = scratch0();
    __ lw(scratch, ToMemOperand(input));
    __ mtc1(scratch, single_scratch);
  } else {
    __ mtc1(ToRegister(input), single_scratch);
  }
  __ cvt_d_w(ToDoubleRegister(output), single_scratch);
}


void LCodeGen::DoUint32ToDouble(LUint32ToDouble* instr) {
  LOperand* input = instr->value();
  LOperand* output = instr->result();

  FPURegister dbl_scratch = double_scratch0();
  __ mtc1(ToRegister(input), dbl_scratch);
  __ Cvt_d_uw(ToDoubleRegister(output), dbl_scratch, f22);
}


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

  Register src = ToRegister(instr->value());
  Register dst = ToRegister(instr->result());
  Register overflow = scratch0();

  DeferredNumberTagI* deferred = new(zone()) DeferredNumberTagI(this, instr);
  __ SmiTagCheckOverflow(dst, src, overflow);
  __ BranchOnOverflow(deferred->entry(), overflow);
  __ bind(deferred->exit());
}


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

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

  DeferredNumberTagU* deferred = new(zone()) DeferredNumberTagU(this, instr);
  __ Branch(deferred->entry(), hi, reg, Operand(Smi::kMaxValue));
  __ SmiTag(reg, reg);
  __ bind(deferred->exit());
}


void LCodeGen::DoDeferredNumberTagI(LInstruction* instr,
                                    LOperand* value,
                                    IntegerSignedness signedness) {
  Label slow;
  Register src = ToRegister(value);
  Register dst = ToRegister(instr->result());
  FPURegister dbl_scratch = double_scratch0();

  // Preserve the value of all registers.
  PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);

  Label done;
  if (signedness == SIGNED_INT32) {
    // There was overflow, so bits 30 and 31 of the original integer
    // disagree. Try to allocate a heap number in new space and store
    // the value in there. If that fails, call the runtime system.
    if (dst.is(src)) {
      __ SmiUntag(src, dst);
      __ Xor(src, src, Operand(0x80000000));
    }
    __ mtc1(src, dbl_scratch);
    __ cvt_d_w(dbl_scratch, dbl_scratch);
  } else {
    __ mtc1(src, dbl_scratch);
    __ Cvt_d_uw(dbl_scratch, dbl_scratch, f22);
  }

  if (FLAG_inline_new) {
    __ LoadRoot(t2, Heap::kHeapNumberMapRootIndex);
    __ AllocateHeapNumber(t1, a3, t0, t2, &slow);
    __ Move(dst, t1);
    __ Branch(&done);
  }

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

  // TODO(3095996): Put a valid pointer value in the stack slot where the result
  // register is stored, as this register is in the pointer map, but contains an
  // integer value.
  __ StoreToSafepointRegisterSlot(zero_reg, dst);
  CallRuntimeFromDeferred(Runtime::kAllocateHeapNumber, 0, instr);
  __ Move(dst, v0);

  // Done. Put the value in dbl_scratch into the value of the allocated heap
  // number.
  __ bind(&done);
  __ sdc1(dbl_scratch, FieldMemOperand(dst, HeapNumber::kValueOffset));
  __ StoreToSafepointRegisterSlot(dst, dst);
}


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

  DoubleRegister input_reg = ToDoubleRegister(instr->value());
  Register scratch = scratch0();
  Register reg = ToRegister(instr->result());
  Register temp1 = ToRegister(instr->temp());
  Register temp2 = ToRegister(instr->temp2());

  DeferredNumberTagD* deferred = new(zone()) DeferredNumberTagD(this, instr);
  if (FLAG_inline_new) {
    __ LoadRoot(scratch, Heap::kHeapNumberMapRootIndex);
    __ AllocateHeapNumber(reg, temp1, temp2, scratch, deferred->entry());
  } else {
    __ Branch(deferred->entry());
  }
  __ bind(deferred->exit());
  __ sdc1(input_reg, FieldMemOperand(reg, HeapNumber::kValueOffset));
}


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());
  __ mov(reg, zero_reg);

  PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
  CallRuntimeFromDeferred(Runtime::kAllocateHeapNumber, 0, instr);
  __ StoreToSafepointRegisterSlot(v0, reg);
}


void LCodeGen::DoSmiTag(LSmiTag* instr) {
  ASSERT(!instr->hydrogen_value()->CheckFlag(HValue::kCanOverflow));
  __ SmiTag(ToRegister(instr->result()), ToRegister(instr->value()));
}


void LCodeGen::DoSmiUntag(LSmiUntag* instr) {
  Register scratch = scratch0();
  Register input = ToRegister(instr->value());
  Register result = ToRegister(instr->result());
  if (instr->needs_check()) {
    STATIC_ASSERT(kHeapObjectTag == 1);
    // If the input is a HeapObject, value of scratch won't be zero.
    __ And(scratch, input, Operand(kHeapObjectTag));
    __ SmiUntag(result, input);
    DeoptimizeIf(ne, instr->environment(), scratch, Operand(zero_reg));
  } else {
    __ SmiUntag(result, input);
  }
}


void LCodeGen::EmitNumberUntagD(Register input_reg,
                                DoubleRegister result_reg,
                                bool deoptimize_on_undefined,
                                bool deoptimize_on_minus_zero,
                                LEnvironment* env) {
  Register scratch = scratch0();

  Label load_smi, heap_number, done;

  // Smi check.
  __ UntagAndJumpIfSmi(scratch, input_reg, &load_smi);

  // Heap number map check.
  __ lw(scratch, FieldMemOperand(input_reg, HeapObject::kMapOffset));
  __ LoadRoot(at, Heap::kHeapNumberMapRootIndex);
  if (deoptimize_on_undefined) {
    DeoptimizeIf(ne, env, scratch, Operand(at));
  } else {
    Label heap_number;
    __ Branch(&heap_number, eq, scratch, Operand(at));

    __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
    DeoptimizeIf(ne, env, input_reg, Operand(at));

    // Convert undefined to NaN.
    __ LoadRoot(at, Heap::kNanValueRootIndex);
    __ ldc1(result_reg, FieldMemOperand(at, HeapNumber::kValueOffset));
    __ Branch(&done);

    __ bind(&heap_number);
  }
  // Heap number to double register conversion.
  __ ldc1(result_reg, FieldMemOperand(input_reg, HeapNumber::kValueOffset));
  if (deoptimize_on_minus_zero) {
    __ mfc1(at, result_reg.low());
    __ Branch(&done, ne, at, Operand(zero_reg));
    __ mfc1(scratch, result_reg.high());
    DeoptimizeIf(eq, env, scratch, Operand(HeapNumber::kSignMask));
  }
  __ Branch(&done);

  // Smi to double register conversion
  __ bind(&load_smi);
  // scratch: untagged value of input_reg
  __ mtc1(scratch, result_reg);
  __ cvt_d_w(result_reg, result_reg);
  __ bind(&done);
}


void LCodeGen::DoDeferredTaggedToI(LTaggedToI* instr) {
  Register input_reg = ToRegister(instr->value());
  Register scratch1 = scratch0();
  Register scratch2 = ToRegister(instr->temp());
  DoubleRegister double_scratch = double_scratch0();
  FPURegister single_scratch = double_scratch.low();

  ASSERT(!scratch1.is(input_reg) && !scratch1.is(scratch2));
  ASSERT(!scratch2.is(input_reg) && !scratch2.is(scratch1));

  Label done;

  // The input is a tagged HeapObject.
  // Heap number map check.
  __ lw(scratch1, FieldMemOperand(input_reg, HeapObject::kMapOffset));
  __ LoadRoot(at, Heap::kHeapNumberMapRootIndex);
  // This 'at' value and scratch1 map value are used for tests in both clauses
  // of the if.

  if (instr->truncating()) {
    Register scratch3 = ToRegister(instr->temp2());
    DoubleRegister double_scratch2 = ToDoubleRegister(instr->temp3());
    ASSERT(!scratch3.is(input_reg) &&
           !scratch3.is(scratch1) &&
           !scratch3.is(scratch2));
    // Performs a truncating conversion of a floating point number as used by
    // the JS bitwise operations.
    Label heap_number;
    __ Branch(&heap_number, eq, scratch1, Operand(at));  // HeapNumber map?
    // Check for undefined. Undefined is converted to zero for truncating
    // conversions.
    __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
    DeoptimizeIf(ne, instr->environment(), input_reg, Operand(at));
    ASSERT(ToRegister(instr->result()).is(input_reg));
    __ mov(input_reg, zero_reg);
    __ Branch(&done);

    __ bind(&heap_number);
    __ ldc1(double_scratch2,
            FieldMemOperand(input_reg, HeapNumber::kValueOffset));
    __ EmitECMATruncate(input_reg,
                        double_scratch2,
                        single_scratch,
                        scratch1,
                        scratch2,
                        scratch3);
  } else {
    // Deoptimize if we don't have a heap number.
    DeoptimizeIf(ne, instr->environment(), scratch1, Operand(at));

    // Load the double value.
    __ ldc1(double_scratch,
            FieldMemOperand(input_reg, HeapNumber::kValueOffset));

    Register except_flag = scratch2;
    __ EmitFPUTruncate(kRoundToZero,
                       single_scratch,
                       double_scratch,
                       scratch1,
                       except_flag,
                       kCheckForInexactConversion);

    // Deopt if the operation did not succeed.
    DeoptimizeIf(ne, instr->environment(), except_flag, Operand(zero_reg));

    // Load the result.
    __ mfc1(input_reg, single_scratch);

    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      __ Branch(&done, ne, input_reg, Operand(zero_reg));

      __ mfc1(scratch1, double_scratch.high());
      __ And(scratch1, scratch1, Operand(HeapNumber::kSignMask));
      DeoptimizeIf(ne, instr->environment(), scratch1, Operand(zero_reg));
    }
  }
  __ bind(&done);
}


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

  LOperand* input = instr->value();
  ASSERT(input->IsRegister());
  ASSERT(input->Equals(instr->result()));

  Register input_reg = ToRegister(input);

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

  // Let the deferred code handle the HeapObject case.
  __ JumpIfNotSmi(input_reg, deferred->entry());

  // Smi to int32 conversion.
  __ SmiUntag(input_reg);
  __ bind(deferred->exit());
}


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

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

  EmitNumberUntagD(input_reg, result_reg,
                   instr->hydrogen()->deoptimize_on_undefined(),
                   instr->hydrogen()->deoptimize_on_minus_zero(),
                   instr->environment());
}


void LCodeGen::DoDoubleToI(LDoubleToI* instr) {
  Register result_reg = ToRegister(instr->result());
  Register scratch1 = scratch0();
  Register scratch2 = ToRegister(instr->temp());
  DoubleRegister double_input = ToDoubleRegister(instr->value());
  FPURegister single_scratch = double_scratch0().low();

  if (instr->truncating()) {
    Register scratch3 = ToRegister(instr->temp2());
    __ EmitECMATruncate(result_reg,
                        double_input,
                        single_scratch,
                        scratch1,
                        scratch2,
                        scratch3);
  } else {
    Register except_flag = scratch2;

    __ EmitFPUTruncate(kRoundToMinusInf,
                       single_scratch,
                       double_input,
                       scratch1,
                       except_flag,
                       kCheckForInexactConversion);

    // Deopt if the operation did not succeed (except_flag != 0).
    DeoptimizeIf(ne, instr->environment(), except_flag, Operand(zero_reg));

    // Load the result.
    __ mfc1(result_reg, single_scratch);
  }
}


void LCodeGen::DoCheckSmi(LCheckSmi* instr) {
  LOperand* input = instr->value();
  __ And(at, ToRegister(input), Operand(kSmiTagMask));
  DeoptimizeIf(ne, instr->environment(), at, Operand(zero_reg));
}


void LCodeGen::DoCheckNonSmi(LCheckNonSmi* instr) {
  LOperand* input = instr->value();
  __ And(at, ToRegister(input), Operand(kSmiTagMask));
  DeoptimizeIf(eq, instr->environment(), at, Operand(zero_reg));
}


void LCodeGen::DoCheckInstanceType(LCheckInstanceType* instr) {
  Register input = ToRegister(instr->value());
  Register scratch = scratch0();

  __ GetObjectType(input, scratch, scratch);

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

    // If there is only one type in the interval check for equality.
    if (first == last) {
      DeoptimizeIf(ne, instr->environment(), scratch, Operand(first));
    } else {
      DeoptimizeIf(lo, instr->environment(), scratch, Operand(first));
      // Omit check for the last type.
      if (last != LAST_TYPE) {
        DeoptimizeIf(hi, instr->environment(), scratch, Operand(last));
      }
    }
  } else {
    uint8_t mask;
    uint8_t tag;
    instr->hydrogen()->GetCheckMaskAndTag(&mask, &tag);

    if (IsPowerOf2(mask)) {
      ASSERT(tag == 0 || IsPowerOf2(tag));
      __ And(at, scratch, mask);
      DeoptimizeIf(tag == 0 ? ne : eq, instr->environment(),
          at, Operand(zero_reg));
    } else {
      __ And(scratch, scratch, Operand(mask));
      DeoptimizeIf(ne, instr->environment(), scratch, Operand(tag));
    }
  }
}


void LCodeGen::DoCheckFunction(LCheckFunction* instr) {
  Register reg = ToRegister(instr->value());
  Handle<JSFunction> target = instr->hydrogen()->target();
  if (isolate()->heap()->InNewSpace(*target)) {
    Register reg = ToRegister(instr->value());
    Handle<JSGlobalPropertyCell> cell =
        isolate()->factory()->NewJSGlobalPropertyCell(target);
    __ li(at, Operand(Handle<Object>(cell)));
    __ lw(at, FieldMemOperand(at, JSGlobalPropertyCell::kValueOffset));
    DeoptimizeIf(ne, instr->environment(), reg,
                 Operand(at));
  } else {
    DeoptimizeIf(ne, instr->environment(), reg,
                 Operand(target));
  }
}


void LCodeGen::DoCheckMapCommon(Register reg,
                                Register scratch,
                                Handle<Map> map,
                                CompareMapMode mode,
                                LEnvironment* env) {
  Label success;
  __ CompareMapAndBranch(reg, scratch, map, &success, eq, &success, mode);
  DeoptimizeIf(al, env);
  __ bind(&success);
}


void LCodeGen::DoCheckMaps(LCheckMaps* instr) {
  Register scratch = scratch0();
  LOperand* input = instr->value();
  ASSERT(input->IsRegister());
  Register reg = ToRegister(input);
  Label success;
  SmallMapList* map_set = instr->hydrogen()->map_set();
  for (int i = 0; i < map_set->length() - 1; i++) {
    Handle<Map> map = map_set->at(i);
    __ CompareMapAndBranch(
        reg, scratch, map, &success, eq, &success, REQUIRE_EXACT_MAP);
  }
  Handle<Map> map = map_set->last();
  DoCheckMapCommon(reg, scratch, map, REQUIRE_EXACT_MAP, instr->environment());
  __ bind(&success);
}


void LCodeGen::DoClampDToUint8(LClampDToUint8* instr) {
  DoubleRegister value_reg = ToDoubleRegister(instr->unclamped());
  Register result_reg = ToRegister(instr->result());
  DoubleRegister temp_reg = ToDoubleRegister(instr->temp());
  __ ClampDoubleToUint8(result_reg, value_reg, temp_reg);
}


void LCodeGen::DoClampIToUint8(LClampIToUint8* instr) {
  Register unclamped_reg = ToRegister(instr->unclamped());
  Register result_reg = ToRegister(instr->result());
  __ ClampUint8(result_reg, unclamped_reg);
}


void LCodeGen::DoClampTToUint8(LClampTToUint8* instr) {
  Register scratch = scratch0();
  Register input_reg = ToRegister(instr->unclamped());
  Register result_reg = ToRegister(instr->result());
  DoubleRegister temp_reg = ToDoubleRegister(instr->temp());
  Label is_smi, done, heap_number;

  // Both smi and heap number cases are handled.
  __ UntagAndJumpIfSmi(scratch, input_reg, &is_smi);

  // Check for heap number
  __ lw(scratch, FieldMemOperand(input_reg, HeapObject::kMapOffset));
  __ Branch(&heap_number, eq, scratch, Operand(factory()->heap_number_map()));

  // Check for undefined. Undefined is converted to zero for clamping
  // conversions.
  DeoptimizeIf(ne, instr->environment(), input_reg,
               Operand(factory()->undefined_value()));
  __ mov(result_reg, zero_reg);
  __ jmp(&done);

  // Heap number
  __ bind(&heap_number);
  __ ldc1(double_scratch0(), FieldMemOperand(input_reg,
                                             HeapNumber::kValueOffset));
  __ ClampDoubleToUint8(result_reg, double_scratch0(), temp_reg);
  __ jmp(&done);

  __ bind(&is_smi);
  __ ClampUint8(result_reg, scratch);

  __ bind(&done);
}


void LCodeGen::DoCheckPrototypeMaps(LCheckPrototypeMaps* instr) {
  Register temp1 = ToRegister(instr->temp());
  Register temp2 = ToRegister(instr->temp2());

  Handle<JSObject> holder = instr->holder();
  Handle<JSObject> current_prototype = instr->prototype();

  // Load prototype object.
  __ LoadHeapObject(temp1, current_prototype);

  // Check prototype maps up to the holder.
  while (!current_prototype.is_identical_to(holder)) {
    DoCheckMapCommon(temp1, temp2,
                     Handle<Map>(current_prototype->map()),
                     ALLOW_ELEMENT_TRANSITION_MAPS, instr->environment());
    current_prototype =
        Handle<JSObject>(JSObject::cast(current_prototype->GetPrototype()));
    // Load next prototype object.
    __ LoadHeapObject(temp1, current_prototype);
  }

  // Check the holder map.
  DoCheckMapCommon(temp1, temp2,
                   Handle<Map>(current_prototype->map()),
                   ALLOW_ELEMENT_TRANSITION_MAPS, instr->environment());
}


void LCodeGen::DoAllocateObject(LAllocateObject* instr) {
  class DeferredAllocateObject: public LDeferredCode {
   public:
    DeferredAllocateObject(LCodeGen* codegen, LAllocateObject* instr)
        : LDeferredCode(codegen), instr_(instr) { }
    virtual void Generate() { codegen()->DoDeferredAllocateObject(instr_); }
    virtual LInstruction* instr() { return instr_; }
   private:
    LAllocateObject* instr_;
  };

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

  Register result = ToRegister(instr->result());
  Register scratch = ToRegister(instr->temp());
  Register scratch2 = ToRegister(instr->temp2());
  Handle<JSFunction> constructor = instr->hydrogen()->constructor();
  Handle<Map> initial_map(constructor->initial_map());
  int instance_size = initial_map->instance_size();
  ASSERT(initial_map->pre_allocated_property_fields() +
         initial_map->unused_property_fields() -
         initial_map->inobject_properties() == 0);

  // Allocate memory for the object.  The initial map might change when
  // the constructor's prototype changes, but instance size and property
  // counts remain unchanged (if slack tracking finished).
  ASSERT(!constructor->shared()->IsInobjectSlackTrackingInProgress());
  __ AllocateInNewSpace(instance_size,
                        result,
                        scratch,
                        scratch2,
                        deferred->entry(),
                        TAG_OBJECT);

  __ bind(deferred->exit());
  if (FLAG_debug_code) {
    Label is_in_new_space;
    __ JumpIfInNewSpace(result, scratch, &is_in_new_space);
    __ Abort("Allocated object is not in new-space");
    __ bind(&is_in_new_space);
  }

  // Load the initial map.
  Register map = scratch;
  __ LoadHeapObject(map, constructor);
  __ lw(map, FieldMemOperand(map, JSFunction::kPrototypeOrInitialMapOffset));

  // Initialize map and fields of the newly allocated object.
  ASSERT(initial_map->instance_type() == JS_OBJECT_TYPE);
  __ sw(map, FieldMemOperand(result, JSObject::kMapOffset));
  __ LoadRoot(scratch, Heap::kEmptyFixedArrayRootIndex);
  __ sw(scratch, FieldMemOperand(result, JSObject::kElementsOffset));
  __ sw(scratch, FieldMemOperand(result, JSObject::kPropertiesOffset));
  if (initial_map->inobject_properties() != 0) {
    __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
    for (int i = 0; i < initial_map->inobject_properties(); i++) {
      int property_offset = JSObject::kHeaderSize + i * kPointerSize;
      __ sw(scratch, FieldMemOperand(result, property_offset));
    }
  }
}


void LCodeGen::DoDeferredAllocateObject(LAllocateObject* instr) {
  Register result = ToRegister(instr->result());
  Handle<JSFunction> constructor = instr->hydrogen()->constructor();
  Handle<Map> initial_map(constructor->initial_map());
  int instance_size = initial_map->instance_size();

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

  PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
  __ li(a0, Operand(Smi::FromInt(instance_size)));
  __ push(a0);
  CallRuntimeFromDeferred(Runtime::kAllocateInNewSpace, 1, instr);
  __ StoreToSafepointRegisterSlot(v0, result);
}


void LCodeGen::DoArrayLiteral(LArrayLiteral* instr) {
  Handle<FixedArray> literals(instr->environment()->closure()->literals());
  ElementsKind boilerplate_elements_kind =
      instr->hydrogen()->boilerplate_elements_kind();

  // Deopt if the array literal boilerplate ElementsKind is of a type different
  // than the expected one. The check isn't necessary if the boilerplate has
  // already been converted to TERMINAL_FAST_ELEMENTS_KIND.
  if (CanTransitionToMoreGeneralFastElementsKind(
          boilerplate_elements_kind, true)) {
    __ LoadHeapObject(a1, instr->hydrogen()->boilerplate_object());
    // Load map into a2.
    __ lw(a2, FieldMemOperand(a1, HeapObject::kMapOffset));
    // Load the map's "bit field 2".
    __ lbu(a2, FieldMemOperand(a2, Map::kBitField2Offset));
    // Retrieve elements_kind from bit field 2.
    __ Ext(a2, a2, Map::kElementsKindShift, Map::kElementsKindBitCount);
    DeoptimizeIf(ne,
                 instr->environment(),
                 a2,
                 Operand(boilerplate_elements_kind));
  }

  // Set up the parameters to the stub/runtime call.
  __ LoadHeapObject(a3, literals);
  __ li(a2, Operand(Smi::FromInt(instr->hydrogen()->literal_index())));
  // Boilerplate already exists, constant elements are never accessed.
  // Pass an empty fixed array.
  __ li(a1, Operand(isolate()->factory()->empty_fixed_array()));
  __ Push(a3, a2, a1);

  // Pick the right runtime function or stub to call.
  int length = instr->hydrogen()->length();
  if (instr->hydrogen()->IsCopyOnWrite()) {
    ASSERT(instr->hydrogen()->depth() == 1);
    FastCloneShallowArrayStub::Mode mode =
        FastCloneShallowArrayStub::COPY_ON_WRITE_ELEMENTS;
    FastCloneShallowArrayStub stub(mode, length);
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
  } else if (instr->hydrogen()->depth() > 1) {
    CallRuntime(Runtime::kCreateArrayLiteral, 3, instr);
  } else if (length > FastCloneShallowArrayStub::kMaximumClonedLength) {
    CallRuntime(Runtime::kCreateArrayLiteralShallow, 3, instr);
  } else {
    FastCloneShallowArrayStub::Mode mode =
        boilerplate_elements_kind == FAST_DOUBLE_ELEMENTS
            ? FastCloneShallowArrayStub::CLONE_DOUBLE_ELEMENTS
            : FastCloneShallowArrayStub::CLONE_ELEMENTS;
    FastCloneShallowArrayStub stub(mode, length);
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
  }
}


void LCodeGen::EmitDeepCopy(Handle<JSObject> object,
                            Register result,
                            Register source,
                            int* offset) {
  ASSERT(!source.is(a2));
  ASSERT(!result.is(a2));

  // Only elements backing stores for non-COW arrays need to be copied.
  Handle<FixedArrayBase> elements(object->elements());
  bool has_elements = elements->length() > 0 &&
      elements->map() != isolate()->heap()->fixed_cow_array_map();

  // Increase the offset so that subsequent objects end up right after
  // this object and its backing store.
  int object_offset = *offset;
  int object_size = object->map()->instance_size();
  int elements_offset = *offset + object_size;
  int elements_size = has_elements ? elements->Size() : 0;
  *offset += object_size + elements_size;

  // Copy object header.
  ASSERT(object->properties()->length() == 0);
  int inobject_properties = object->map()->inobject_properties();
  int header_size = object_size - inobject_properties * kPointerSize;
  for (int i = 0; i < header_size; i += kPointerSize) {
    if (has_elements && i == JSObject::kElementsOffset) {
      __ Addu(a2, result, Operand(elements_offset));
    } else {
      __ lw(a2, FieldMemOperand(source, i));
    }
    __ sw(a2, FieldMemOperand(result, object_offset + i));
  }

  // Copy in-object properties.
  for (int i = 0; i < inobject_properties; i++) {
    int total_offset = object_offset + object->GetInObjectPropertyOffset(i);
    Handle<Object> value = Handle<Object>(object->InObjectPropertyAt(i));
    if (value->IsJSObject()) {
      Handle<JSObject> value_object = Handle<JSObject>::cast(value);
      __ Addu(a2, result, Operand(*offset));
      __ sw(a2, FieldMemOperand(result, total_offset));
      __ LoadHeapObject(source, value_object);
      EmitDeepCopy(value_object, result, source, offset);
    } else if (value->IsHeapObject()) {
      __ LoadHeapObject(a2, Handle<HeapObject>::cast(value));
      __ sw(a2, FieldMemOperand(result, total_offset));
    } else {
      __ li(a2, Operand(value));
      __ sw(a2, FieldMemOperand(result, total_offset));
    }
  }


  if (has_elements) {
    // Copy elements backing store header.
    __ LoadHeapObject(source, elements);
    for (int i = 0; i < FixedArray::kHeaderSize; i += kPointerSize) {
      __ lw(a2, FieldMemOperand(source, i));
      __ sw(a2, FieldMemOperand(result, elements_offset + i));
    }

    // Copy elements backing store content.
    int elements_length = has_elements ? elements->length() : 0;
    if (elements->IsFixedDoubleArray()) {
      Handle<FixedDoubleArray> double_array =
          Handle<FixedDoubleArray>::cast(elements);
      for (int i = 0; i < elements_length; i++) {
        int64_t value = double_array->get_representation(i);
        // We only support little endian mode...
        int32_t value_low = static_cast<int32_t>(value & 0xFFFFFFFF);
        int32_t value_high = static_cast<int32_t>(value >> 32);
        int total_offset =
            elements_offset + FixedDoubleArray::OffsetOfElementAt(i);
        __ li(a2, Operand(value_low));
        __ sw(a2, FieldMemOperand(result, total_offset));
        __ li(a2, Operand(value_high));
        __ sw(a2, FieldMemOperand(result, total_offset + 4));
      }
    } else if (elements->IsFixedArray()) {
      Handle<FixedArray> fast_elements = Handle<FixedArray>::cast(elements);
      for (int i = 0; i < elements_length; i++) {
        int total_offset = elements_offset + FixedArray::OffsetOfElementAt(i);
        Handle<Object> value(fast_elements->get(i));
        if (value->IsJSObject()) {
          Handle<JSObject> value_object = Handle<JSObject>::cast(value);
          __ Addu(a2, result, Operand(*offset));
          __ sw(a2, FieldMemOperand(result, total_offset));
          __ LoadHeapObject(source, value_object);
          EmitDeepCopy(value_object, result, source, offset);
        } else if (value->IsHeapObject()) {
          __ LoadHeapObject(a2, Handle<HeapObject>::cast(value));
          __ sw(a2, FieldMemOperand(result, total_offset));
        } else {
          __ li(a2, Operand(value));
          __ sw(a2, FieldMemOperand(result, total_offset));
        }
      }
    } else {
      UNREACHABLE();
    }
  }
}


void LCodeGen::DoFastLiteral(LFastLiteral* instr) {
  int size = instr->hydrogen()->total_size();
  ElementsKind boilerplate_elements_kind =
      instr->hydrogen()->boilerplate()->GetElementsKind();

  // Deopt if the array literal boilerplate ElementsKind is of a type different
  // than the expected one. The check isn't necessary if the boilerplate has
  // already been converted to TERMINAL_FAST_ELEMENTS_KIND.
  if (CanTransitionToMoreGeneralFastElementsKind(
          boilerplate_elements_kind, true)) {
    __ LoadHeapObject(a1, instr->hydrogen()->boilerplate());
    // Load map into a2.
    __ lw(a2, FieldMemOperand(a1, HeapObject::kMapOffset));
    // Load the map's "bit field 2".
    __ lbu(a2, FieldMemOperand(a2, Map::kBitField2Offset));
    // Retrieve elements_kind from bit field 2.
    __ Ext(a2, a2, Map::kElementsKindShift, Map::kElementsKindBitCount);
    DeoptimizeIf(ne, instr->environment(), a2,
        Operand(boilerplate_elements_kind));
  }

  // Allocate all objects that are part of the literal in one big
  // allocation. This avoids multiple limit checks.
  Label allocated, runtime_allocate;
  __ AllocateInNewSpace(size, v0, a2, a3, &runtime_allocate, TAG_OBJECT);
  __ jmp(&allocated);

  __ bind(&runtime_allocate);
  __ li(a0, Operand(Smi::FromInt(size)));
  __ push(a0);
  CallRuntime(Runtime::kAllocateInNewSpace, 1, instr);

  __ bind(&allocated);
  int offset = 0;
  __ LoadHeapObject(a1, instr->hydrogen()->boilerplate());
  EmitDeepCopy(instr->hydrogen()->boilerplate(), v0, a1, &offset);
  ASSERT_EQ(size, offset);
}


void LCodeGen::DoObjectLiteral(LObjectLiteral* instr) {
  ASSERT(ToRegister(instr->result()).is(v0));
  Handle<FixedArray> literals(instr->environment()->closure()->literals());
  Handle<FixedArray> constant_properties =
      instr->hydrogen()->constant_properties();

  // Set up the parameters to the stub/runtime call.
  __ LoadHeapObject(t0, literals);
  __ li(a3, Operand(Smi::FromInt(instr->hydrogen()->literal_index())));
  __ li(a2, Operand(constant_properties));
  int flags = instr->hydrogen()->fast_elements()
      ? ObjectLiteral::kFastElements
      : ObjectLiteral::kNoFlags;
  __ li(a1, Operand(Smi::FromInt(flags)));
  __ Push(t0, a3, a2, a1);

  // Pick the right runtime function or stub to call.
  int properties_count = constant_properties->length() / 2;
  if (instr->hydrogen()->depth() > 1) {
    CallRuntime(Runtime::kCreateObjectLiteral, 4, instr);
  } else if (flags != ObjectLiteral::kFastElements ||
      properties_count > FastCloneShallowObjectStub::kMaximumClonedProperties) {
    CallRuntime(Runtime::kCreateObjectLiteralShallow, 4, instr);
  } else {
    FastCloneShallowObjectStub stub(properties_count);
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
  }
}


void LCodeGen::DoToFastProperties(LToFastProperties* instr) {
  ASSERT(ToRegister(instr->value()).is(a0));
  ASSERT(ToRegister(instr->result()).is(v0));
  __ push(a0);
  CallRuntime(Runtime::kToFastProperties, 1, instr);
}


void LCodeGen::DoRegExpLiteral(LRegExpLiteral* instr) {
  Label materialized;
  // Registers will be used as follows:
  // t3 = literals array.
  // a1 = regexp literal.
  // a0 = regexp literal clone.
  // a2 and t0-t2 are used as temporaries.
  int literal_offset =
      FixedArray::OffsetOfElementAt(instr->hydrogen()->literal_index());
  __ LoadHeapObject(t3, instr->hydrogen()->literals());
  __ lw(a1, FieldMemOperand(t3, literal_offset));
  __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
  __ Branch(&materialized, ne, a1, Operand(at));

  // Create regexp literal using runtime function
  // Result will be in v0.
  __ li(t2, Operand(Smi::FromInt(instr->hydrogen()->literal_index())));
  __ li(t1, Operand(instr->hydrogen()->pattern()));
  __ li(t0, Operand(instr->hydrogen()->flags()));
  __ Push(t3, t2, t1, t0);
  CallRuntime(Runtime::kMaterializeRegExpLiteral, 4, instr);
  __ mov(a1, v0);

  __ bind(&materialized);
  int size = JSRegExp::kSize + JSRegExp::kInObjectFieldCount * kPointerSize;
  Label allocated, runtime_allocate;

  __ AllocateInNewSpace(size, v0, a2, a3, &runtime_allocate, TAG_OBJECT);
  __ jmp(&allocated);

  __ bind(&runtime_allocate);
  __ li(a0, Operand(Smi::FromInt(size)));
  __ Push(a1, a0);
  CallRuntime(Runtime::kAllocateInNewSpace, 1, instr);
  __ pop(a1);

  __ 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) {
    __ lw(a3, FieldMemOperand(a1, i));
    __ lw(a2, FieldMemOperand(a1, i + kPointerSize));
    __ sw(a3, FieldMemOperand(v0, i));
    __ sw(a2, FieldMemOperand(v0, i + kPointerSize));
  }
  if ((size % (2 * kPointerSize)) != 0) {
    __ lw(a3, FieldMemOperand(a1, size - kPointerSize));
    __ sw(a3, FieldMemOperand(v0, size - kPointerSize));
  }
}


void LCodeGen::DoFunctionLiteral(LFunctionLiteral* instr) {
  // Use the fast case closure allocation code that allocates in new
  // space for nested functions that don't need literals cloning.
  Handle<SharedFunctionInfo> shared_info = instr->shared_info();
  bool pretenure = instr->hydrogen()->pretenure();
  if (!pretenure && shared_info->num_literals() == 0) {
    FastNewClosureStub stub(shared_info->language_mode());
    __ li(a1, Operand(shared_info));
    __ push(a1);
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
  } else {
    __ li(a2, Operand(shared_info));
    __ li(a1, Operand(pretenure
                       ? factory()->true_value()
                       : factory()->false_value()));
    __ Push(cp, a2, a1);
    CallRuntime(Runtime::kNewClosure, 3, instr);
  }
}


void LCodeGen::DoTypeof(LTypeof* instr) {
  ASSERT(ToRegister(instr->result()).is(v0));
  Register input = ToRegister(instr->value());
  __ push(input);
  CallRuntime(Runtime::kTypeof, 1, instr);
}


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

  Register cmp1 = no_reg;
  Operand cmp2 = Operand(no_reg);

  Condition final_branch_condition = EmitTypeofIs(true_label,
                                                  false_label,
                                                  input,
                                                  instr->type_literal(),
                                                  cmp1,
                                                  cmp2);

  ASSERT(cmp1.is_valid());
  ASSERT(!cmp2.is_reg() || cmp2.rm().is_valid());

  if (final_branch_condition != kNoCondition) {
    EmitBranch(true_block, false_block, final_branch_condition, cmp1, cmp2);
  }
}


Condition LCodeGen::EmitTypeofIs(Label* true_label,
                                 Label* false_label,
                                 Register input,
                                 Handle<String> type_name,
                                 Register& cmp1,
                                 Operand& cmp2) {
  // This function utilizes the delay slot heavily. This is used to load
  // values that are always usable without depending on the type of the input
  // register.
  Condition final_branch_condition = kNoCondition;
  Register scratch = scratch0();
  if (type_name->Equals(heap()->number_symbol())) {
    __ JumpIfSmi(input, true_label);
    __ lw(input, FieldMemOperand(input, HeapObject::kMapOffset));
    __ LoadRoot(at, Heap::kHeapNumberMapRootIndex);
    cmp1 = input;
    cmp2 = Operand(at);
    final_branch_condition = eq;

  } else if (type_name->Equals(heap()->string_symbol())) {
    __ JumpIfSmi(input, false_label);
    __ GetObjectType(input, input, scratch);
    __ Branch(USE_DELAY_SLOT, false_label,
              ge, scratch, Operand(FIRST_NONSTRING_TYPE));
    // input is an object so we can load the BitFieldOffset even if we take the
    // other branch.
    __ lbu(at, FieldMemOperand(input, Map::kBitFieldOffset));
    __ And(at, at, 1 << Map::kIsUndetectable);
    cmp1 = at;
    cmp2 = Operand(zero_reg);
    final_branch_condition = eq;

  } else if (type_name->Equals(heap()->boolean_symbol())) {
    __ LoadRoot(at, Heap::kTrueValueRootIndex);
    __ Branch(USE_DELAY_SLOT, true_label, eq, at, Operand(input));
    __ LoadRoot(at, Heap::kFalseValueRootIndex);
    cmp1 = at;
    cmp2 = Operand(input);
    final_branch_condition = eq;

  } else if (FLAG_harmony_typeof && type_name->Equals(heap()->null_symbol())) {
    __ LoadRoot(at, Heap::kNullValueRootIndex);
    cmp1 = at;
    cmp2 = Operand(input);
    final_branch_condition = eq;

  } else if (type_name->Equals(heap()->undefined_symbol())) {
    __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
    __ Branch(USE_DELAY_SLOT, true_label, eq, at, Operand(input));
    // The first instruction of JumpIfSmi is an And - it is safe in the delay
    // slot.
    __ JumpIfSmi(input, false_label);
    // Check for undetectable objects => true.
    __ lw(input, FieldMemOperand(input, HeapObject::kMapOffset));
    __ lbu(at, FieldMemOperand(input, Map::kBitFieldOffset));
    __ And(at, at, 1 << Map::kIsUndetectable);
    cmp1 = at;
    cmp2 = Operand(zero_reg);
    final_branch_condition = ne;

  } else if (type_name->Equals(heap()->function_symbol())) {
    STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
    __ JumpIfSmi(input, false_label);
    __ GetObjectType(input, scratch, input);
    __ Branch(true_label, eq, input, Operand(JS_FUNCTION_TYPE));
    cmp1 = input;
    cmp2 = Operand(JS_FUNCTION_PROXY_TYPE);
    final_branch_condition = eq;

  } else if (type_name->Equals(heap()->object_symbol())) {
    __ JumpIfSmi(input, false_label);
    if (!FLAG_harmony_typeof) {
      __ LoadRoot(at, Heap::kNullValueRootIndex);
      __ Branch(USE_DELAY_SLOT, true_label, eq, at, Operand(input));
    }
    // input is an object, it is safe to use GetObjectType in the delay slot.
    __ GetObjectType(input, input, scratch);
    __ Branch(USE_DELAY_SLOT, false_label,
              lt, scratch, Operand(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
    // Still an object, so the InstanceType can be loaded.
    __ lbu(scratch, FieldMemOperand(input, Map::kInstanceTypeOffset));
    __ Branch(USE_DELAY_SLOT, false_label,
              gt, scratch, Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE));
    // Still an object, so the BitField can be loaded.
    // Check for undetectable objects => false.
    __ lbu(at, FieldMemOperand(input, Map::kBitFieldOffset));
    __ And(at, at, 1 << Map::kIsUndetectable);
    cmp1 = at;
    cmp2 = Operand(zero_reg);
    final_branch_condition = eq;

  } else {
    cmp1 = at;
    cmp2 = Operand(zero_reg);  // Set to valid regs, to avoid caller assertion.
    __ Branch(false_label);
  }

  return final_branch_condition;
}


void LCodeGen::DoIsConstructCallAndBranch(LIsConstructCallAndBranch* instr) {
  Register temp1 = ToRegister(instr->temp());
  int true_block = chunk_->LookupDestination(instr->true_block_id());
  int false_block = chunk_->LookupDestination(instr->false_block_id());

  EmitIsConstructCall(temp1, scratch0());

  EmitBranch(true_block, false_block, eq, temp1,
             Operand(Smi::FromInt(StackFrame::CONSTRUCT)));
}


void LCodeGen::EmitIsConstructCall(Register temp1, Register temp2) {
  ASSERT(!temp1.is(temp2));
  // Get the frame pointer for the calling frame.
  __ lw(temp1, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));

  // Skip the arguments adaptor frame if it exists.
  Label check_frame_marker;
  __ lw(temp2, MemOperand(temp1, StandardFrameConstants::kContextOffset));
  __ Branch(&check_frame_marker, ne, temp2,
            Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
  __ lw(temp1, MemOperand(temp1, StandardFrameConstants::kCallerFPOffset));

  // Check the marker in the calling frame.
  __ bind(&check_frame_marker);
  __ lw(temp1, MemOperand(temp1, StandardFrameConstants::kMarkerOffset));
}


void LCodeGen::EnsureSpaceForLazyDeopt() {
  // Ensure that we have enough space after the previous lazy-bailout
  // instruction for patching the code here.
  int current_pc = masm()->pc_offset();
  int patch_size = Deoptimizer::patch_size();
  if (current_pc < last_lazy_deopt_pc_ + patch_size) {
    int padding_size = last_lazy_deopt_pc_ + patch_size - current_pc;
    ASSERT_EQ(0, padding_size % Assembler::kInstrSize);
    while (padding_size > 0) {
      __ nop();
      padding_size -= Assembler::kInstrSize;
    }
  }
  last_lazy_deopt_pc_ = masm()->pc_offset();
}


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


void LCodeGen::DoDeoptimize(LDeoptimize* instr) {
  DeoptimizeIf(al, instr->environment(), zero_reg, Operand(zero_reg));
}


void LCodeGen::DoDeleteProperty(LDeleteProperty* instr) {
  Register object = ToRegister(instr->object());
  Register key = ToRegister(instr->key());
  Register strict = scratch0();
  __ li(strict, Operand(Smi::FromInt(strict_mode_flag())));
  __ Push(object, key, strict);
  ASSERT(instr->HasPointerMap());
  LPointerMap* pointers = instr->pointer_map();
  RecordPosition(pointers->position());
  SafepointGenerator safepoint_generator(
      this, pointers, Safepoint::kLazyDeopt);
  __ InvokeBuiltin(Builtins::DELETE, CALL_FUNCTION, safepoint_generator);
}


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


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


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

  ASSERT(instr->HasEnvironment());
  LEnvironment* env = instr->environment();
  // There is no LLazyBailout instruction for stack-checks. We have to
  // prepare for lazy deoptimization explicitly here.
  if (instr->hydrogen()->is_function_entry()) {
    // Perform stack overflow check.
    Label done;
    __ LoadRoot(at, Heap::kStackLimitRootIndex);
    __ Branch(&done, hs, sp, Operand(at));
    StackCheckStub stub;
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
    EnsureSpaceForLazyDeopt();
    __ bind(&done);
    RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
    safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
  } else {
    ASSERT(instr->hydrogen()->is_backwards_branch());
    // Perform stack overflow check if this goto needs it before jumping.
    DeferredStackCheck* deferred_stack_check =
        new(zone()) DeferredStackCheck(this, instr);
    __ LoadRoot(at, Heap::kStackLimitRootIndex);
    __ Branch(deferred_stack_check->entry(), lo, sp, Operand(at));
    EnsureSpaceForLazyDeopt();
    __ bind(instr->done_label());
    deferred_stack_check->SetExit(instr->done_label());
    RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
    // Don't record a deoptimization index for the safepoint here.
    // This will be done explicitly when emitting call and the safepoint in
    // the deferred code.
  }
}


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

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


void LCodeGen::DoForInPrepareMap(LForInPrepareMap* instr) {
  Register result = ToRegister(instr->result());
  Register object = ToRegister(instr->object());
  __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
  DeoptimizeIf(eq, instr->environment(), object, Operand(at));

  Register null_value = t1;
  __ LoadRoot(null_value, Heap::kNullValueRootIndex);
  DeoptimizeIf(eq, instr->environment(), object, Operand(null_value));

  __ And(at, object, kSmiTagMask);
  DeoptimizeIf(eq, instr->environment(), at, Operand(zero_reg));

  STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
  __ GetObjectType(object, a1, a1);
  DeoptimizeIf(le, instr->environment(), a1, Operand(LAST_JS_PROXY_TYPE));

  Label use_cache, call_runtime;
  ASSERT(object.is(a0));
  __ CheckEnumCache(null_value, &call_runtime);

  __ lw(result, FieldMemOperand(object, HeapObject::kMapOffset));
  __ Branch(&use_cache);

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

  __ lw(a1, FieldMemOperand(v0, HeapObject::kMapOffset));
  ASSERT(result.is(v0));
  __ LoadRoot(at, Heap::kMetaMapRootIndex);
  DeoptimizeIf(ne, instr->environment(), a1, Operand(at));
  __ 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);
  __ Branch(&load_cache, ne, result, Operand(Smi::FromInt(0)));
  __ li(result, Operand(isolate()->factory()->empty_fixed_array()));
  __ jmp(&done);

  __ bind(&load_cache);
  __ LoadInstanceDescriptors(map, result);
  __ lw(result,
        FieldMemOperand(result, DescriptorArray::kEnumCacheOffset));
  __ lw(result,
        FieldMemOperand(result, FixedArray::SizeFor(instr->idx())));
  DeoptimizeIf(eq, instr->environment(), result, Operand(zero_reg));

  __ bind(&done);
}


void LCodeGen::DoCheckMapValue(LCheckMapValue* instr) {
  Register object = ToRegister(instr->value());
  Register map = ToRegister(instr->map());
  __ lw(scratch0(), FieldMemOperand(object, HeapObject::kMapOffset));
  DeoptimizeIf(ne, instr->environment(), map, Operand(scratch0()));
}


void LCodeGen::DoLoadFieldByIndex(LLoadFieldByIndex* instr) {
  Register object = ToRegister(instr->object());
  Register index = ToRegister(instr->index());
  Register result = ToRegister(instr->result());
  Register scratch = scratch0();

  Label out_of_object, done;
  __ Branch(USE_DELAY_SLOT, &out_of_object, lt, index, Operand(zero_reg));
  __ sll(scratch, index, kPointerSizeLog2 - kSmiTagSize);  // In delay slot.

  STATIC_ASSERT(kPointerSizeLog2 > kSmiTagSize);
  __ Addu(scratch, object, scratch);
  __ lw(result, FieldMemOperand(scratch, JSObject::kHeaderSize));

  __ Branch(&done);

  __ bind(&out_of_object);
  __ lw(result, FieldMemOperand(object, JSObject::kPropertiesOffset));
  // Index is equal to negated out of object property index plus 1.
  __ Subu(scratch, result, scratch);
  __ lw(result, FieldMemOperand(scratch,
                                FixedArray::kHeaderSize - kPointerSize));
  __ bind(&done);
}


#undef __

} }  // namespace v8::internal