text: // Copyright 2013 the V8 project authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #include "src/v8.h"
  
  #include "src/arm64/lithium-codegen-arm64.h"
  #include "src/arm64/lithium-gap-resolver-arm64.h"
  #include "src/base/bits.h"
  #include "src/code-factory.h"
  #include "src/code-stubs.h"
  #include "src/hydrogen-osr.h"
  #include "src/ic/ic.h"
  #include "src/ic/stub-cache.h"
  
  namespace v8 {
  namespace internal {
  
  
  class SafepointGenerator FINAL : public CallWrapper {
   public:
    SafepointGenerator(LCodeGen* codegen,
                       LPointerMap* pointers,
                       Safepoint::DeoptMode mode)
        : codegen_(codegen),
          pointers_(pointers),
          deopt_mode_(mode) { }
    virtual ~SafepointGenerator() { }
  
    virtual void BeforeCall(int call_size) const { }
  
    virtual void AfterCall() const {
      codegen_->RecordSafepoint(pointers_, deopt_mode_);
    }
  
   private:
    LCodeGen* codegen_;
    LPointerMap* pointers_;
    Safepoint::DeoptMode deopt_mode_;
  };
  
  
  #define __ masm()->
  
  // Emit code to branch if the given condition holds.
  // The code generated here doesn't modify the flags and they must have
  // been set by some prior instructions.
  //
  // The EmitInverted function simply inverts the condition.
  class BranchOnCondition : public BranchGenerator {
   public:
    BranchOnCondition(LCodeGen* codegen, Condition cond)
      : BranchGenerator(codegen),
        cond_(cond) { }
  
    virtual void Emit(Label* label) const {
      __ B(cond_, label);
    }
  
    virtual void EmitInverted(Label* label) const {
      if (cond_ != al) {
        __ B(NegateCondition(cond_), label);
      }
    }
  
   private:
    Condition cond_;
  };
  
  
  // Emit code to compare lhs and rhs and branch if the condition holds.
  // This uses MacroAssembler's CompareAndBranch function so it will handle
  // converting the comparison to Cbz/Cbnz if the right-hand side is 0.
  //
  // EmitInverted still compares the two operands but inverts the condition.
  class CompareAndBranch : public BranchGenerator {
   public:
    CompareAndBranch(LCodeGen* codegen,
                     Condition cond,
                     const Register& lhs,
                     const Operand& rhs)
      : BranchGenerator(codegen),
        cond_(cond),
        lhs_(lhs),
        rhs_(rhs) { }
  
    virtual void Emit(Label* label) const {
      __ CompareAndBranch(lhs_, rhs_, cond_, label);
    }
  
    virtual void EmitInverted(Label* label) const {
      __ CompareAndBranch(lhs_, rhs_, NegateCondition(cond_), label);
    }
  
   private:
    Condition cond_;
    const Register& lhs_;
    const Operand& rhs_;
  };
  
  
  // Test the input with the given mask and branch if the condition holds.
  // If the condition is 'eq' or 'ne' this will use MacroAssembler's
  // TestAndBranchIfAllClear and TestAndBranchIfAnySet so it will handle the
  // conversion to Tbz/Tbnz when possible.
  class TestAndBranch : public BranchGenerator {
   public:
    TestAndBranch(LCodeGen* codegen,
                  Condition cond,
                  const Register& value,
                  uint64_t mask)
      : BranchGenerator(codegen),
        cond_(cond),
        value_(value),
        mask_(mask) { }
  
    virtual void Emit(Label* label) const {
      switch (cond_) {
        case eq:
          __ TestAndBranchIfAllClear(value_, mask_, label);
          break;
        case ne:
          __ TestAndBranchIfAnySet(value_, mask_, label);
          break;
        default:
          __ Tst(value_, mask_);
          __ B(cond_, label);
      }
    }
  
    virtual void EmitInverted(Label* label) const {
      // The inverse of "all clear" is "any set" and vice versa.
      switch (cond_) {
        case eq:
          __ TestAndBranchIfAnySet(value_, mask_, label);
          break;
        case ne:
          __ TestAndBranchIfAllClear(value_, mask_, label);
          break;
        default:
          __ Tst(value_, mask_);
          __ B(NegateCondition(cond_), label);
      }
    }
  
   private:
    Condition cond_;
    const Register& value_;
    uint64_t mask_;
  };
  
  
  // Test the input and branch if it is non-zero and not a NaN.
  class BranchIfNonZeroNumber : public BranchGenerator {
   public:
    BranchIfNonZeroNumber(LCodeGen* codegen, const FPRegister& value,
                          const FPRegister& scratch)
      : BranchGenerator(codegen), value_(value), scratch_(scratch) { }
  
    virtual void Emit(Label* label) const {
      __ Fabs(scratch_, value_);
      // Compare with 0.0. Because scratch_ is positive, the result can be one of
      // nZCv (equal), nzCv (greater) or nzCV (unordered).
      __ Fcmp(scratch_, 0.0);
      __ B(gt, label);
    }
  
    virtual void EmitInverted(Label* label) const {
      __ Fabs(scratch_, value_);
      __ Fcmp(scratch_, 0.0);
      __ B(le, label);
    }
  
   private:
    const FPRegister& value_;
    const FPRegister& scratch_;
  };
  
  
  // Test the input and branch if it is a heap number.
  class BranchIfHeapNumber : public BranchGenerator {
   public:
    BranchIfHeapNumber(LCodeGen* codegen, const Register& value)
        : BranchGenerator(codegen), value_(value) { }
  
    virtual void Emit(Label* label) const {
      __ JumpIfHeapNumber(value_, label);
    }
  
    virtual void EmitInverted(Label* label) const {
      __ JumpIfNotHeapNumber(value_, label);
    }
  
   private:
    const Register& value_;
  };
  
  
  // Test the input and branch if it is the specified root value.
  class BranchIfRoot : public BranchGenerator {
   public:
    BranchIfRoot(LCodeGen* codegen, const Register& value,
                 Heap::RootListIndex index)
        : BranchGenerator(codegen), value_(value), index_(index) { }
  
    virtual void Emit(Label* label) const {
      __ JumpIfRoot(value_, index_, label);
    }
  
    virtual void EmitInverted(Label* label) const {
      __ JumpIfNotRoot(value_, index_, label);
    }
  
   private:
    const Register& value_;
    const Heap::RootListIndex index_;
  };
  
  
  void LCodeGen::WriteTranslation(LEnvironment* environment,
                                  Translation* translation) {
    if (environment == NULL) return;
  
    // The translation includes one command per value in the environment.
    int translation_size = environment->translation_size();
    // The output frame height does not include the parameters.
    int height = translation_size - environment->parameter_count();
  
    WriteTranslation(environment->outer(), translation);
    bool has_closure_id = !info()->closure().is_null() &&
        !info()->closure().is_identical_to(environment->closure());
    int closure_id = has_closure_id
        ? DefineDeoptimizationLiteral(environment->closure())
        : Translation::kSelfLiteralId;
  
    switch (environment->frame_type()) {
      case JS_FUNCTION:
        translation->BeginJSFrame(environment->ast_id(), closure_id, height);
        break;
      case JS_CONSTRUCT:
        translation->BeginConstructStubFrame(closure_id, translation_size);
        break;
      case JS_GETTER:
        DCHECK(translation_size == 1);
        DCHECK(height == 0);
        translation->BeginGetterStubFrame(closure_id);
        break;
      case JS_SETTER:
        DCHECK(translation_size == 2);
        DCHECK(height == 0);
        translation->BeginSetterStubFrame(closure_id);
        break;
      case STUB:
        translation->BeginCompiledStubFrame();
        break;
      case ARGUMENTS_ADAPTOR:
        translation->BeginArgumentsAdaptorFrame(closure_id, translation_size);
        break;
      default:
        UNREACHABLE();
    }
  
    int object_index = 0;
    int dematerialized_index = 0;
    for (int i = 0; i < translation_size; ++i) {
      LOperand* value = environment->values()->at(i);
  
      AddToTranslation(environment,
                       translation,
                       value,
                       environment->HasTaggedValueAt(i),
                       environment->HasUint32ValueAt(i),
                       &object_index,
                       &dematerialized_index);
    }
  }
  
  
  void LCodeGen::AddToTranslation(LEnvironment* environment,
                                  Translation* translation,
                                  LOperand* op,
                                  bool is_tagged,
                                  bool is_uint32,
                                  int* object_index_pointer,
                                  int* dematerialized_index_pointer) {
    if (op == LEnvironment::materialization_marker()) {
      int object_index = (*object_index_pointer)++;
      if (environment->ObjectIsDuplicateAt(object_index)) {
        int dupe_of = environment->ObjectDuplicateOfAt(object_index);
        translation->DuplicateObject(dupe_of);
        return;
      }
      int object_length = environment->ObjectLengthAt(object_index);
      if (environment->ObjectIsArgumentsAt(object_index)) {
        translation->BeginArgumentsObject(object_length);
      } else {
        translation->BeginCapturedObject(object_length);
      }
      int dematerialized_index = *dematerialized_index_pointer;
      int env_offset = environment->translation_size() + dematerialized_index;
      *dematerialized_index_pointer += object_length;
      for (int i = 0; i < object_length; ++i) {
        LOperand* value = environment->values()->at(env_offset + i);
        AddToTranslation(environment,
                         translation,
                         value,
                         environment->HasTaggedValueAt(env_offset + i),
                         environment->HasUint32ValueAt(env_offset + i),
                         object_index_pointer,
                         dematerialized_index_pointer);
      }
      return;
    }
  
    if (op->IsStackSlot()) {
      if (is_tagged) {
        translation->StoreStackSlot(op->index());
      } else if (is_uint32) {
        translation->StoreUint32StackSlot(op->index());
      } else {
        translation->StoreInt32StackSlot(op->index());
      }
    } else if (op->IsDoubleStackSlot()) {
      translation->StoreDoubleStackSlot(op->index());
    } else if (op->IsRegister()) {
      Register reg = ToRegister(op);
      if (is_tagged) {
        translation->StoreRegister(reg);
      } else if (is_uint32) {
        translation->StoreUint32Register(reg);
      } else {
        translation->StoreInt32Register(reg);
      }
    } else if (op->IsDoubleRegister()) {
      DoubleRegister reg = ToDoubleRegister(op);
      translation->StoreDoubleRegister(reg);
    } else if (op->IsConstantOperand()) {
      HConstant* constant = chunk()->LookupConstant(LConstantOperand::cast(op));
      int src_index = DefineDeoptimizationLiteral(constant->handle(isolate()));
      translation->StoreLiteral(src_index);
    } else {
      UNREACHABLE();
    }
  }
  
  
  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::RegisterEnvironmentForDeoptimization(LEnvironment* environment,
                                                      Safepoint::DeoptMode mode) {
    environment->set_has_been_used();
    if (!environment->HasBeenRegistered()) {
      int frame_count = 0;
      int jsframe_count = 0;
      for (LEnvironment* e = environment; e != NULL; e = e->outer()) {
        ++frame_count;
        if (e->frame_type() == JS_FUNCTION) {
          ++jsframe_count;
        }
      }
      Translation translation(&translations_, frame_count, jsframe_count, zone());
      WriteTranslation(environment, &translation);
      int deoptimization_index = deoptimizations_.length();
      int pc_offset = masm()->pc_offset();
      environment->Register(deoptimization_index,
                            translation.index(),
                            (mode == Safepoint::kLazyDeopt) ? pc_offset : -1);
      deoptimizations_.Add(environment, zone());
    }
  }
  
  
  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) {
    DCHECK(instr != NULL);
  
    Assembler::BlockPoolsScope scope(masm_);
    __ Call(code, mode);
    RecordSafepointWithLazyDeopt(instr, safepoint_mode);
  
    if ((code->kind() == Code::BINARY_OP_IC) ||
        (code->kind() == Code::COMPARE_IC)) {
      // Signal that we don't inline smi code before these stubs in the
      // optimizing code generator.
      InlineSmiCheckInfo::EmitNotInlined(masm());
    }
  }
  
  
  void LCodeGen::DoCallFunction(LCallFunction* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->function()).Is(x1));
    DCHECK(ToRegister(instr->result()).Is(x0));
  
    int arity = instr->arity();
    CallFunctionStub stub(isolate(), arity, instr->hydrogen()->function_flags());
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
    after_push_argument_ = false;
  }
  
  
  void LCodeGen::DoCallNew(LCallNew* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(instr->IsMarkedAsCall());
    DCHECK(ToRegister(instr->constructor()).is(x1));
  
    __ Mov(x0, instr->arity());
    // No cell in x2 for construct type feedback in optimized code.
    __ LoadRoot(x2, Heap::kUndefinedValueRootIndex);
  
    CallConstructStub stub(isolate(), NO_CALL_CONSTRUCTOR_FLAGS);
    CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
    after_push_argument_ = false;
  
    DCHECK(ToRegister(instr->result()).is(x0));
  }
  
  
  void LCodeGen::DoCallNewArray(LCallNewArray* instr) {
    DCHECK(instr->IsMarkedAsCall());
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->constructor()).is(x1));
  
    __ Mov(x0, Operand(instr->arity()));
    __ LoadRoot(x2, Heap::kUndefinedValueRootIndex);
  
    ElementsKind kind = instr->hydrogen()->elements_kind();
    AllocationSiteOverrideMode override_mode =
        (AllocationSite::GetMode(kind) == TRACK_ALLOCATION_SITE)
            ? DISABLE_ALLOCATION_SITES
            : DONT_OVERRIDE;
  
    if (instr->arity() == 0) {
      ArrayNoArgumentConstructorStub stub(isolate(), kind, override_mode);
      CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
    } else if (instr->arity() == 1) {
      Label done;
      if (IsFastPackedElementsKind(kind)) {
        Label packed_case;
  
        // We might need to create a holey array; look at the first argument.
        __ Peek(x10, 0);
        __ Cbz(x10, &packed_case);
  
        ElementsKind holey_kind = GetHoleyElementsKind(kind);
        ArraySingleArgumentConstructorStub stub(isolate(),
                                                holey_kind,
                                                override_mode);
        CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
        __ B(&done);
        __ Bind(&packed_case);
      }
  
      ArraySingleArgumentConstructorStub stub(isolate(), kind, override_mode);
      CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
      __ Bind(&done);
    } else {
      ArrayNArgumentsConstructorStub stub(isolate(), kind, override_mode);
      CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
    }
    after_push_argument_ = false;
  
    DCHECK(ToRegister(instr->result()).is(x0));
  }
  
  
  void LCodeGen::CallRuntime(const Runtime::Function* function,
                             int num_arguments,
                             LInstruction* instr,
                             SaveFPRegsMode save_doubles) {
    DCHECK(instr != NULL);
  
    __ CallRuntime(function, num_arguments, save_doubles);
  
    RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
  }
  
  
  void LCodeGen::LoadContextFromDeferred(LOperand* context) {
    if (context->IsRegister()) {
      __ Mov(cp, ToRegister(context));
    } else if (context->IsStackSlot()) {
      __ Ldr(cp, ToMemOperand(context, kMustUseFramePointer));
    } else if (context->IsConstantOperand()) {
      HConstant* constant =
          chunk_->LookupConstant(LConstantOperand::cast(context));
      __ LoadHeapObject(cp,
                        Handle<HeapObject>::cast(constant->handle(isolate())));
    } else {
      UNREACHABLE();
    }
  }
  
  
  void LCodeGen::CallRuntimeFromDeferred(Runtime::FunctionId id,
                                         int argc,
                                         LInstruction* instr,
                                         LOperand* context) {
    LoadContextFromDeferred(context);
    __ CallRuntimeSaveDoubles(id);
    RecordSafepointWithRegisters(
        instr->pointer_map(), argc, Safepoint::kNoLazyDeopt);
  }
  
  
  void LCodeGen::RecordAndWritePosition(int position) {
    if (position == RelocInfo::kNoPosition) return;
    masm()->positions_recorder()->RecordPosition(position);
    masm()->positions_recorder()->WriteRecordedPositions();
  }
  
  
  void LCodeGen::RecordSafepointWithLazyDeopt(LInstruction* instr,
                                              SafepointMode safepoint_mode) {
    if (safepoint_mode == RECORD_SIMPLE_SAFEPOINT) {
      RecordSafepoint(instr->pointer_map(), Safepoint::kLazyDeopt);
    } else {
      DCHECK(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) {
    DCHECK(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(zone());
    RecordSafepoint(&empty_pointers, deopt_mode);
  }
  
  
  void LCodeGen::RecordSafepointWithRegisters(LPointerMap* pointers,
                                              int arguments,
                                              Safepoint::DeoptMode deopt_mode) {
    RecordSafepoint(pointers, Safepoint::kWithRegisters, arguments, deopt_mode);
  }
  
  
  bool LCodeGen::GenerateCode() {
    LPhase phase("Z_Code generation", chunk());
    DCHECK(is_unused());
    status_ = GENERATING;
  
    // Open a frame scope to indicate that there is a frame on the stack.  The
    // 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() &&
           GenerateJumpTable() && GenerateSafepointTable();
  }
  
  
  void LCodeGen::SaveCallerDoubles() {
    DCHECK(info()->saves_caller_doubles());
    DCHECK(NeedsEagerFrame());
    Comment(";;; Save clobbered callee double registers");
    BitVector* doubles = chunk()->allocated_double_registers();
    BitVector::Iterator iterator(doubles);
    int count = 0;
    while (!iterator.Done()) {
      // TODO(all): Is this supposed to save just the callee-saved doubles? It
      // looks like it's saving all of them.
      FPRegister value = FPRegister::FromAllocationIndex(iterator.Current());
      __ Poke(value, count * kDoubleSize);
      iterator.Advance();
      count++;
    }
  }
  
  
  void LCodeGen::RestoreCallerDoubles() {
    DCHECK(info()->saves_caller_doubles());
    DCHECK(NeedsEagerFrame());
    Comment(";;; Restore clobbered callee double registers");
    BitVector* doubles = chunk()->allocated_double_registers();
    BitVector::Iterator iterator(doubles);
    int count = 0;
    while (!iterator.Done()) {
      // TODO(all): Is this supposed to restore just the callee-saved doubles? It
      // looks like it's restoring all of them.
      FPRegister value = FPRegister::FromAllocationIndex(iterator.Current());
      __ Peek(value, count * kDoubleSize);
      iterator.Advance();
      count++;
    }
  }
  
  
  bool LCodeGen::GeneratePrologue() {
    DCHECK(is_generating());
  
    if (info()->IsOptimizing()) {
      ProfileEntryHookStub::MaybeCallEntryHook(masm_);
  
      // TODO(all): Add support for stop_t FLAG in DEBUG mode.
  
      // Sloppy mode functions and builtins need to replace the receiver with the
      // global proxy when called as functions (without an explicit receiver
      // object).
      if (info_->this_has_uses() &&
          info_->strict_mode() == SLOPPY &&
          !info_->is_native()) {
        Label ok;
        int receiver_offset = info_->scope()->num_parameters() * kXRegSize;
        __ Peek(x10, receiver_offset);
        __ JumpIfNotRoot(x10, Heap::kUndefinedValueRootIndex, &ok);
  
        __ Ldr(x10, GlobalObjectMemOperand());
        __ Ldr(x10, FieldMemOperand(x10, GlobalObject::kGlobalProxyOffset));
        __ Poke(x10, receiver_offset);
  
        __ Bind(&ok);
      }
    }
  
    DCHECK(__ StackPointer().Is(jssp));
    info()->set_prologue_offset(masm_->pc_offset());
    if (NeedsEagerFrame()) {
      if (info()->IsStub()) {
        __ StubPrologue();
      } else {
        __ Prologue(info()->IsCodePreAgingActive());
      }
      frame_is_built_ = true;
      info_->AddNoFrameRange(0, masm_->pc_offset());
    }
  
    // Reserve space for the stack slots needed by the code.
    int slots = GetStackSlotCount();
    if (slots > 0) {
      __ Claim(slots, kPointerSize);
    }
  
    if (info()->saves_caller_doubles()) {
      SaveCallerDoubles();
    }
  
    // Allocate a local context if needed.
    int heap_slots = info()->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
    if (heap_slots > 0) {
      Comment(";;; Allocate local context");
      bool need_write_barrier = true;
      // Argument to NewContext is the function, which is in x1.
      if (heap_slots <= FastNewContextStub::kMaximumSlots) {
        FastNewContextStub stub(isolate(), heap_slots);
        __ CallStub(&stub);
        // Result of FastNewContextStub is always in new space.
        need_write_barrier = false;
      } else {
        __ Push(x1);
        __ CallRuntime(Runtime::kNewFunctionContext, 1);
      }
      RecordSafepoint(Safepoint::kNoLazyDeopt);
      // Context is returned in x0. It replaces the context passed to us. It's
      // saved in the stack and kept live in cp.
      __ Mov(cp, x0);
      __ Str(x0, 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()) {
          Register value = x0;
          Register scratch = x3;
  
          int parameter_offset = StandardFrameConstants::kCallerSPOffset +
              (num_parameters - 1 - i) * kPointerSize;
          // Load parameter from stack.
          __ Ldr(value, MemOperand(fp, parameter_offset));
          // Store it in the context.
          MemOperand target = ContextMemOperand(cp, var->index());
          __ Str(value, target);
          // Update the write barrier. This clobbers value and scratch.
          if (need_write_barrier) {
            __ RecordWriteContextSlot(cp, target.offset(), value, scratch,
                                      GetLinkRegisterState(), kSaveFPRegs);
          } else if (FLAG_debug_code) {
            Label done;
            __ JumpIfInNewSpace(cp, &done);
            __ Abort(kExpectedNewSpaceObject);
            __ bind(&done);
          }
        }
      }
      Comment(";;; End allocate local context");
    }
  
    // Trace the call.
    if (FLAG_trace && info()->IsOptimizing()) {
      // We have not executed any compiled code yet, so cp still holds the
      // incoming context.
      __ CallRuntime(Runtime::kTraceEnter, 0);
    }
  
    return !is_aborted();
  }
  
  
  void LCodeGen::GenerateOsrPrologue() {
    // Generate the OSR entry prologue at the first unknown OSR value, or if there
    // are none, at the OSR entrypoint instruction.
    if (osr_pc_offset_ >= 0) return;
  
    osr_pc_offset_ = masm()->pc_offset();
  
    // Adjust the frame size, subsuming the unoptimized frame into the
    // optimized frame.
    int slots = GetStackSlotCount() - graph()->osr()->UnoptimizedFrameSlots();
    DCHECK(slots >= 0);
    __ Claim(slots);
  }
  
  
  void LCodeGen::GenerateBodyInstructionPre(LInstruction* instr) {
    if (instr->IsCall()) {
      EnsureSpaceForLazyDeopt(Deoptimizer::patch_size());
    }
    if (!instr->IsLazyBailout() && !instr->IsGap()) {
      safepoints_.BumpLastLazySafepointIndex();
    }
  }
  
  
  bool LCodeGen::GenerateDeferredCode() {
    DCHECK(is_generating());
    if (deferred_.length() > 0) {
      for (int i = 0; !is_aborted() && (i < deferred_.length()); i++) {
        LDeferredCode* code = deferred_[i];
  
        HValue* value =
            instructions_->at(code->instruction_index())->hydrogen_value();
        RecordAndWritePosition(
            chunk()->graph()->SourcePositionToScriptPosition(value->position()));
  
        Comment(";;; <@%d,#%d> "
                "-------------------- Deferred %s --------------------",
                code->instruction_index(),
                code->instr()->hydrogen_value()->id(),
                code->instr()->Mnemonic());
  
        __ Bind(code->entry());
  
        if (NeedsDeferredFrame()) {
          Comment(";;; Build frame");
          DCHECK(!frame_is_built_);
          DCHECK(info()->IsStub());
          frame_is_built_ = true;
          __ Push(lr, fp, cp);
          __ Mov(fp, Smi::FromInt(StackFrame::STUB));
          __ Push(fp);
          __ Add(fp, __ StackPointer(),
                 StandardFrameConstants::kFixedFrameSizeFromFp);
          Comment(";;; Deferred code");
        }
  
        code->Generate();
  
        if (NeedsDeferredFrame()) {
          Comment(";;; Destroy frame");
          DCHECK(frame_is_built_);
          __ Pop(xzr, cp, fp, lr);
          frame_is_built_ = false;
        }
  
        __ B(code->exit());
      }
    }
  
    // Force constant pool emission at the end of the deferred code to make
    // sure that no constant pools are emitted after deferred code because
    // deferred code generation is the last step which generates code. The two
    // following steps will only output data used by crakshaft.
    masm()->CheckConstPool(true, false);
  
    return !is_aborted();
  }
  
  
  bool LCodeGen::GenerateJumpTable() {
    Label needs_frame, restore_caller_doubles, call_deopt_entry;
  
    if (jump_table_.length() > 0) {
      Comment(";;; -------------------- Jump table --------------------");
      Address base = jump_table_[0]->address;
  
      UseScratchRegisterScope temps(masm());
      Register entry_offset = temps.AcquireX();
  
      int length = jump_table_.length();
      for (int i = 0; i < length; i++) {
        Deoptimizer::JumpTableEntry* table_entry = jump_table_[i];
        __ Bind(&table_entry->label);
  
        Address entry = table_entry->address;
        DeoptComment(table_entry->reason);
  
        // Second-level deopt table entries are contiguous and small, so instead
        // of loading the full, absolute address of each one, load the base
        // address and add an immediate offset.
        __ Mov(entry_offset, entry - base);
  
        // The last entry can fall through into `call_deopt_entry`, avoiding a
        // branch.
        bool last_entry = (i + 1) == length;
  
        if (table_entry->needs_frame) {
          DCHECK(!info()->saves_caller_doubles());
          if (!needs_frame.is_bound()) {
            // This variant of deopt can only be used with stubs. Since we don't
            // have a function pointer to install in the stack frame that we're
            // building, install a special marker there instead.
            DCHECK(info()->IsStub());
  
            UseScratchRegisterScope temps(masm());
            Register stub_marker = temps.AcquireX();
            __ Bind(&needs_frame);
            __ Mov(stub_marker, Smi::FromInt(StackFrame::STUB));
            __ Push(lr, fp, cp, stub_marker);
            __ Add(fp, __ StackPointer(), 2 * kPointerSize);
            if (!last_entry) __ B(&call_deopt_entry);
          } else {
            // Reuse the existing needs_frame code.
            __ B(&needs_frame);
          }
        } else if (info()->saves_caller_doubles()) {
          DCHECK(info()->IsStub());
          if (!restore_caller_doubles.is_bound()) {
            __ Bind(&restore_caller_doubles);
            RestoreCallerDoubles();
            if (!last_entry) __ B(&call_deopt_entry);
          } else {
            // Reuse the existing restore_caller_doubles code.
            __ B(&restore_caller_doubles);
          }
        } else {
          // There is nothing special to do, so just continue to the second-level
          // table.
          if (!last_entry) __ B(&call_deopt_entry);
        }
  
        masm()->CheckConstPool(false, last_entry);
      }
  
      // Generate common code for calling the second-level deopt table.
      Register deopt_entry = temps.AcquireX();
      __ Bind(&call_deopt_entry);
      __ Mov(deopt_entry, Operand(reinterpret_cast<uint64_t>(base),
                                  RelocInfo::RUNTIME_ENTRY));
      __ Add(deopt_entry, deopt_entry, entry_offset);
      __ Call(deopt_entry);
    }
  
    // Force constant pool emission at the end of the deopt jump table to make
    // sure that no constant pools are emitted after.
    masm()->CheckConstPool(true, false);
  
    // The deoptimization jump table is the last part of the instruction
    // sequence. Mark the generated code as done unless we bailed out.
    if (!is_aborted()) status_ = DONE;
    return !is_aborted();
  }
  
  
  bool LCodeGen::GenerateSafepointTable() {
    DCHECK(is_done());
    // We do not know how much data will be emitted for the safepoint table, so
    // force emission of the veneer pool.
    masm()->CheckVeneerPool(true, true);
    safepoints_.Emit(masm(), GetStackSlotCount());
    return !is_aborted();
  }
  
  
  void LCodeGen::FinishCode(Handle<Code> code) {
    DCHECK(is_done());
    code->set_stack_slots(GetStackSlotCount());
    code->set_safepoint_table_offset(safepoints_.GetCodeOffset());
    if (code->is_optimized_code()) RegisterWeakObjectsInOptimizedCode(code);
    PopulateDeoptimizationData(code);
  }
  
  
  void LCodeGen::PopulateDeoptimizationData(Handle<Code> code) {
    int length = deoptimizations_.length();
    if (length == 0) return;
  
    Handle<DeoptimizationInputData> data =
        DeoptimizationInputData::New(isolate(), length, TENURED);
  
    Handle<ByteArray> translations =
        translations_.CreateByteArray(isolate()->factory());
    data->SetTranslationByteArray(*translations);
    data->SetInlinedFunctionCount(Smi::FromInt(inlined_function_count_));
    data->SetOptimizationId(Smi::FromInt(info_->optimization_id()));
    if (info_->IsOptimizing()) {
      // Reference to shared function info does not change between phases.
      AllowDeferredHandleDereference allow_handle_dereference;
      data->SetSharedFunctionInfo(*info_->shared_info());
    } else {
      data->SetSharedFunctionInfo(Smi::FromInt(0));
    }
  
    Handle<FixedArray> literals =
        factory()->NewFixedArray(deoptimization_literals_.length(), TENURED);
    { AllowDeferredHandleDereference copy_handles;
      for (int i = 0; i < deoptimization_literals_.length(); i++) {
        literals->set(i, *deoptimization_literals_[i]);
      }
      data->SetLiteralArray(*literals);
    }
  
    data->SetOsrAstId(Smi::FromInt(info_->osr_ast_id().ToInt()));
    data->SetOsrPcOffset(Smi::FromInt(osr_pc_offset_));
  
    // Populate the deoptimization entries.
    for (int i = 0; i < length; i++) {
      LEnvironment* env = deoptimizations_[i];
      data->SetAstId(i, env->ast_id());
      data->SetTranslationIndex(i, Smi::FromInt(env->translation_index()));
      data->SetArgumentsStackHeight(i,
                                    Smi::FromInt(env->arguments_stack_height()));
      data->SetPc(i, Smi::FromInt(env->pc_offset()));
    }
  
    code->set_deoptimization_data(*data);
  }
  
  
  void LCodeGen::PopulateDeoptimizationLiteralsWithInlinedFunctions() {
    DCHECK(deoptimization_literals_.length() == 0);
  
    const ZoneList<Handle<JSFunction> >* inlined_closures =
        chunk()->inlined_closures();
  
    for (int i = 0, length = inlined_closures->length(); i < length; i++) {
      DefineDeoptimizationLiteral(inlined_closures->at(i));
    }
  
    inlined_function_count_ = deoptimization_literals_.length();
  }
  
  
  void LCodeGen::DeoptimizeBranch(
      LInstruction* instr, const char* detail, BranchType branch_type,
      Register reg, int bit, Deoptimizer::BailoutType* override_bailout_type) {
    LEnvironment* environment = instr->environment();
    RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
    Deoptimizer::BailoutType bailout_type =
      info()->IsStub() ? Deoptimizer::LAZY : Deoptimizer::EAGER;
  
    if (override_bailout_type != NULL) {
      bailout_type = *override_bailout_type;
    }
  
    DCHECK(environment->HasBeenRegistered());
    DCHECK(info()->IsOptimizing() || info()->IsStub());
    int id = environment->deoptimization_index();
    Address entry =
        Deoptimizer::GetDeoptimizationEntry(isolate(), id, bailout_type);
  
    if (entry == NULL) {
      Abort(kBailoutWasNotPrepared);
    }
  
    if (FLAG_deopt_every_n_times != 0 && !info()->IsStub()) {
      Label not_zero;
      ExternalReference count = ExternalReference::stress_deopt_count(isolate());
  
      __ Push(x0, x1, x2);
      __ Mrs(x2, NZCV);
      __ Mov(x0, count);
      __ Ldr(w1, MemOperand(x0));
      __ Subs(x1, x1, 1);
      __ B(gt, &not_zero);
      __ Mov(w1, FLAG_deopt_every_n_times);
      __ Str(w1, MemOperand(x0));
      __ Pop(x2, x1, x0);
      DCHECK(frame_is_built_);
      __ Call(entry, RelocInfo::RUNTIME_ENTRY);
      __ Unreachable();
  
      __ Bind(&not_zero);
      __ Str(w1, MemOperand(x0));
      __ Msr(NZCV, x2);
      __ Pop(x2, x1, x0);
    }
  
    if (info()->ShouldTrapOnDeopt()) {
      Label dont_trap;
      __ B(&dont_trap, InvertBranchType(branch_type), reg, bit);
      __ Debug("trap_on_deopt", __LINE__, BREAK);
      __ Bind(&dont_trap);
    }
  
    Deoptimizer::Reason reason(instr->hydrogen_value()->position().raw(),
                               instr->Mnemonic(), detail);
    DCHECK(info()->IsStub() || frame_is_built_);
    // Go through jump table if we need to build frame, or restore caller doubles.
    if (branch_type == always &&
        frame_is_built_ && !info()->saves_caller_doubles()) {
      DeoptComment(reason);
      __ Call(entry, RelocInfo::RUNTIME_ENTRY);
    } else {
      Deoptimizer::JumpTableEntry* table_entry =
          new (zone()) Deoptimizer::JumpTableEntry(entry, reason, bailout_type,
                                                   !frame_is_built_);
      // We often have several deopts to the same entry, reuse the last
      // jump entry if this is the case.
      if (jump_table_.is_empty() ||
          !table_entry->IsEquivalentTo(*jump_table_.last())) {
        jump_table_.Add(table_entry, zone());
      }
      __ B(&jump_table_.last()->label, branch_type, reg, bit);
    }
  }
  
  
  void LCodeGen::Deoptimize(LInstruction* instr,
                            Deoptimizer::BailoutType* override_bailout_type,
                            const char* detail) {
    DeoptimizeBranch(instr, detail, always, NoReg, -1, override_bailout_type);
  }
  
  
  void LCodeGen::DeoptimizeIf(Condition cond, LInstruction* instr,
                              const char* detail) {
    DeoptimizeBranch(instr, detail, static_cast<BranchType>(cond));
  }
  
  
  void LCodeGen::DeoptimizeIfZero(Register rt, LInstruction* instr,
                                  const char* detail) {
    DeoptimizeBranch(instr, detail, reg_zero, rt);
  }
  
  
  void LCodeGen::DeoptimizeIfNotZero(Register rt, LInstruction* instr,
                                     const char* detail) {
    DeoptimizeBranch(instr, detail, reg_not_zero, rt);
  }
  
  
  void LCodeGen::DeoptimizeIfNegative(Register rt, LInstruction* instr,
                                      const char* detail) {
    int sign_bit = rt.Is64Bits() ? kXSignBit : kWSignBit;
    DeoptimizeIfBitSet(rt, sign_bit, instr, detail);
  }
  
  
  void LCodeGen::DeoptimizeIfSmi(Register rt, LInstruction* instr,
                                 const char* detail) {
    DeoptimizeIfBitClear(rt, MaskToBit(kSmiTagMask), instr, detail);
  }
  
  
  void LCodeGen::DeoptimizeIfNotSmi(Register rt, LInstruction* instr,
                                    const char* detail) {
    DeoptimizeIfBitSet(rt, MaskToBit(kSmiTagMask), instr, detail);
  }
  
  
  void LCodeGen::DeoptimizeIfRoot(Register rt, Heap::RootListIndex index,
                                  LInstruction* instr, const char* detail) {
    __ CompareRoot(rt, index);
    DeoptimizeIf(eq, instr, detail);
  }
  
  
  void LCodeGen::DeoptimizeIfNotRoot(Register rt, Heap::RootListIndex index,
                                     LInstruction* instr, const char* detail) {
    __ CompareRoot(rt, index);
    DeoptimizeIf(ne, instr, detail);
  }
  
  
  void LCodeGen::DeoptimizeIfMinusZero(DoubleRegister input, LInstruction* instr,
                                       const char* detail) {
    __ TestForMinusZero(input);
    DeoptimizeIf(vs, instr, detail);
  }
  
  
  void LCodeGen::DeoptimizeIfNotHeapNumber(Register object, LInstruction* instr) {
    __ CompareObjectMap(object, Heap::kHeapNumberMapRootIndex);
    DeoptimizeIf(ne, instr, "not heap number");
  }
  
  
  void LCodeGen::DeoptimizeIfBitSet(Register rt, int bit, LInstruction* instr,
                                    const char* detail) {
    DeoptimizeBranch(instr, detail, reg_bit_set, rt, bit);
  }
  
  
  void LCodeGen::DeoptimizeIfBitClear(Register rt, int bit, LInstruction* instr,
                                      const char* detail) {
    DeoptimizeBranch(instr, detail, reg_bit_clear, rt, bit);
  }
  
  
  void LCodeGen::EnsureSpaceForLazyDeopt(int space_needed) {
    if (!info()->IsStub()) {
      // Ensure that we have enough space after the previous lazy-bailout
      // instruction for patching the code here.
      intptr_t current_pc = masm()->pc_offset();
  
      if (current_pc < (last_lazy_deopt_pc_ + space_needed)) {
        ptrdiff_t padding_size = last_lazy_deopt_pc_ + space_needed - current_pc;
        DCHECK((padding_size % kInstructionSize) == 0);
        InstructionAccurateScope instruction_accurate(
            masm(), padding_size / kInstructionSize);
  
        while (padding_size > 0) {
          __ nop();
          padding_size -= kInstructionSize;
        }
      }
    }
    last_lazy_deopt_pc_ = masm()->pc_offset();
  }
  
  
  Register LCodeGen::ToRegister(LOperand* op) const {
    // TODO(all): support zero register results, as ToRegister32.
    DCHECK((op != NULL) && op->IsRegister());
    return Register::FromAllocationIndex(op->index());
  }
  
  
  Register LCodeGen::ToRegister32(LOperand* op) const {
    DCHECK(op != NULL);
    if (op->IsConstantOperand()) {
      // If this is a constant operand, the result must be the zero register.
      DCHECK(ToInteger32(LConstantOperand::cast(op)) == 0);
      return wzr;
    } else {
      return ToRegister(op).W();
    }
  }
  
  
  Smi* LCodeGen::ToSmi(LConstantOperand* op) const {
    HConstant* constant = chunk_->LookupConstant(op);
    return Smi::FromInt(constant->Integer32Value());
  }
  
  
  DoubleRegister LCodeGen::ToDoubleRegister(LOperand* op) const {
    DCHECK((op != NULL) && op->IsDoubleRegister());
    return DoubleRegister::FromAllocationIndex(op->index());
  }
  
  
  Operand LCodeGen::ToOperand(LOperand* op) {
    DCHECK(op != NULL);
    if (op->IsConstantOperand()) {
      LConstantOperand* const_op = LConstantOperand::cast(op);
      HConstant* constant = chunk()->LookupConstant(const_op);
      Representation r = chunk_->LookupLiteralRepresentation(const_op);
      if (r.IsSmi()) {
        DCHECK(constant->HasSmiValue());
        return Operand(Smi::FromInt(constant->Integer32Value()));
      } else if (r.IsInteger32()) {
        DCHECK(constant->HasInteger32Value());
        return Operand(constant->Integer32Value());
      } else if (r.IsDouble()) {
        Abort(kToOperandUnsupportedDoubleImmediate);
      }
      DCHECK(r.IsTagged());
      return Operand(constant->handle(isolate()));
    } else if (op->IsRegister()) {
      return Operand(ToRegister(op));
    } else if (op->IsDoubleRegister()) {
      Abort(kToOperandIsDoubleRegisterUnimplemented);
      return Operand(0);
    }
    // Stack slots not implemented, use ToMemOperand instead.
    UNREACHABLE();
    return Operand(0);
  }
  
  
  Operand LCodeGen::ToOperand32(LOperand* op) {
    DCHECK(op != NULL);
    if (op->IsRegister()) {
      return Operand(ToRegister32(op));
    } else if (op->IsConstantOperand()) {
      LConstantOperand* const_op = LConstantOperand::cast(op);
      HConstant* constant = chunk()->LookupConstant(const_op);
      Representation r = chunk_->LookupLiteralRepresentation(const_op);
      if (r.IsInteger32()) {
        return Operand(constant->Integer32Value());
      } else {
        // Other constants not implemented.
        Abort(kToOperand32UnsupportedImmediate);
      }
    }
    // Other cases are not implemented.
    UNREACHABLE();
    return Operand(0);
  }
  
  
  static int64_t ArgumentsOffsetWithoutFrame(int index) {
    DCHECK(index < 0);
    return -(index + 1) * kPointerSize;
  }
  
  
  MemOperand LCodeGen::ToMemOperand(LOperand* op, StackMode stack_mode) const {
    DCHECK(op != NULL);
    DCHECK(!op->IsRegister());
    DCHECK(!op->IsDoubleRegister());
    DCHECK(op->IsStackSlot() || op->IsDoubleStackSlot());
    if (NeedsEagerFrame()) {
      int fp_offset = StackSlotOffset(op->index());
      if (op->index() >= 0) {
        // Loads and stores have a bigger reach in positive offset than negative.
        // When the load or the store can't be done in one instruction via fp
        // (too big negative offset), we try to access via jssp (positive offset).
        // We can reference a stack slot from jssp only if jssp references the end
        // of the stack slots. It's not the case when:
        //  - stack_mode != kCanUseStackPointer: this is the case when a deferred
        //     code saved the registers.
        //  - after_push_argument_: arguments has been pushed for a call.
        //  - inlined_arguments_: inlined arguments have been pushed once. All the
        //     remainder of the function cannot trust jssp any longer.
        //  - saves_caller_doubles: some double registers have been pushed, jssp
        //     references the end of the double registers and not the end of the
        //     stack slots.
        // Also, if the offset from fp is small enough to make a load/store in
        // one instruction, we use a fp access.
        if ((stack_mode == kCanUseStackPointer) && !after_push_argument_ &&
            !inlined_arguments_ && !is_int9(fp_offset) &&
            !info()->saves_caller_doubles()) {
          int jssp_offset =
              (GetStackSlotCount() - op->index() - 1) * kPointerSize;
          return MemOperand(masm()->StackPointer(), jssp_offset);
        }
      }
      return MemOperand(fp, fp_offset);
    } else {
      // Retrieve parameter without eager stack-frame relative to the
      // stack-pointer.
      return MemOperand(masm()->StackPointer(),
                        ArgumentsOffsetWithoutFrame(op->index()));
    }
  }
  
  
  Handle<Object> LCodeGen::ToHandle(LConstantOperand* op) const {
    HConstant* constant = chunk_->LookupConstant(op);
    DCHECK(chunk_->LookupLiteralRepresentation(op).IsSmiOrTagged());
    return constant->handle(isolate());
  }
  
  
  template <class LI>
  Operand LCodeGen::ToShiftedRightOperand32(LOperand* right, LI* shift_info) {
    if (shift_info->shift() == NO_SHIFT) {
      return ToOperand32(right);
    } else {
      return Operand(
          ToRegister32(right),
          shift_info->shift(),
          JSShiftAmountFromLConstant(shift_info->shift_amount()));
    }
  }
  
  
  bool LCodeGen::IsSmi(LConstantOperand* op) const {
    return chunk_->LookupLiteralRepresentation(op).IsSmi();
  }
  
  
  bool LCodeGen::IsInteger32Constant(LConstantOperand* op) const {
    return chunk_->LookupLiteralRepresentation(op).IsSmiOrInteger32();
  }
  
  
  int32_t LCodeGen::ToInteger32(LConstantOperand* op) const {
    HConstant* constant = chunk_->LookupConstant(op);
    return constant->Integer32Value();
  }
  
  
  double LCodeGen::ToDouble(LConstantOperand* op) const {
    HConstant* constant = chunk_->LookupConstant(op);
    DCHECK(constant->HasDoubleValue());
    return constant->DoubleValue();
  }
  
  
  Condition LCodeGen::TokenToCondition(Token::Value op, bool is_unsigned) {
    Condition cond = nv;
    switch (op) {
      case Token::EQ:
      case Token::EQ_STRICT:
        cond = eq;
        break;
      case Token::NE:
      case Token::NE_STRICT:
        cond = ne;
        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;
  }
  
  
  template<class InstrType>
  void LCodeGen::EmitBranchGeneric(InstrType instr,
                                   const BranchGenerator& branch) {
    int left_block = instr->TrueDestination(chunk_);
    int right_block = instr->FalseDestination(chunk_);
  
    int next_block = GetNextEmittedBlock();
  
    if (right_block == left_block) {
      EmitGoto(left_block);
    } else if (left_block == next_block) {
      branch.EmitInverted(chunk_->GetAssemblyLabel(right_block));
    } else {
      branch.Emit(chunk_->GetAssemblyLabel(left_block));
      if (right_block != next_block) {
        __ B(chunk_->GetAssemblyLabel(right_block));
      }
    }
  }
  
  
  template<class InstrType>
  void LCodeGen::EmitBranch(InstrType instr, Condition condition) {
    DCHECK((condition != al) && (condition != nv));
    BranchOnCondition branch(this, condition);
    EmitBranchGeneric(instr, branch);
  }
  
  
  template<class InstrType>
  void LCodeGen::EmitCompareAndBranch(InstrType instr,
                                      Condition condition,
                                      const Register& lhs,
                                      const Operand& rhs) {
    DCHECK((condition != al) && (condition != nv));
    CompareAndBranch branch(this, condition, lhs, rhs);
    EmitBranchGeneric(instr, branch);
  }
  
  
  template<class InstrType>
  void LCodeGen::EmitTestAndBranch(InstrType instr,
                                   Condition condition,
                                   const Register& value,
                                   uint64_t mask) {
    DCHECK((condition != al) && (condition != nv));
    TestAndBranch branch(this, condition, value, mask);
    EmitBranchGeneric(instr, branch);
  }
  
  
  template<class InstrType>
  void LCodeGen::EmitBranchIfNonZeroNumber(InstrType instr,
                                           const FPRegister& value,
                                           const FPRegister& scratch) {
    BranchIfNonZeroNumber branch(this, value, scratch);
    EmitBranchGeneric(instr, branch);
  }
  
  
  template<class InstrType>
  void LCodeGen::EmitBranchIfHeapNumber(InstrType instr,
                                        const Register& value) {
    BranchIfHeapNumber branch(this, value);
    EmitBranchGeneric(instr, branch);
  }
  
  
  template<class InstrType>
  void LCodeGen::EmitBranchIfRoot(InstrType instr,
                                  const Register& value,
                                  Heap::RootListIndex index) {
    BranchIfRoot branch(this, value, index);
    EmitBranchGeneric(instr, branch);
  }
  
  
  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) {
        resolver_.Resolve(move);
      }
    }
  }
  
  
  void LCodeGen::DoAccessArgumentsAt(LAccessArgumentsAt* instr) {
    Register arguments = ToRegister(instr->arguments());
    Register result = ToRegister(instr->result());
  
    // The pointer to the arguments array come from DoArgumentsElements.
    // It does not point directly to the arguments and there is an offest of
    // two words that we must take into account when accessing an argument.
    // Subtracting the index from length accounts for one, so we add one more.
  
    if (instr->length()->IsConstantOperand() &&
        instr->index()->IsConstantOperand()) {
      int index = ToInteger32(LConstantOperand::cast(instr->index()));
      int length = ToInteger32(LConstantOperand::cast(instr->length()));
      int offset = ((length - index) + 1) * kPointerSize;
      __ Ldr(result, MemOperand(arguments, offset));
    } else if (instr->index()->IsConstantOperand()) {
      Register length = ToRegister32(instr->length());
      int index = ToInteger32(LConstantOperand::cast(instr->index()));
      int loc = index - 1;
      if (loc != 0) {
        __ Sub(result.W(), length, loc);
        __ Ldr(result, MemOperand(arguments, result, UXTW, kPointerSizeLog2));
      } else {
        __ Ldr(result, MemOperand(arguments, length, UXTW, kPointerSizeLog2));
      }
    } else {
      Register length = ToRegister32(instr->length());
      Operand index = ToOperand32(instr->index());
      __ Sub(result.W(), length, index);
      __ Add(result.W(), result.W(), 1);
      __ Ldr(result, MemOperand(arguments, result, UXTW, kPointerSizeLog2));
    }
  }
  
  
  void LCodeGen::DoAddE(LAddE* instr) {
    Register result = ToRegister(instr->result());
    Register left = ToRegister(instr->left());
    Operand right = (instr->right()->IsConstantOperand())
        ? ToInteger32(LConstantOperand::cast(instr->right()))
        : Operand(ToRegister32(instr->right()), SXTW);
  
    DCHECK(!instr->hydrogen()->CheckFlag(HValue::kCanOverflow));
    __ Add(result, left, right);
  }
  
  
  void LCodeGen::DoAddI(LAddI* instr) {
    bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
    Register result = ToRegister32(instr->result());
    Register left = ToRegister32(instr->left());
    Operand right = ToShiftedRightOperand32(instr->right(), instr);
  
    if (can_overflow) {
      __ Adds(result, left, right);
      DeoptimizeIf(vs, instr);
    } else {
      __ Add(result, left, right);
    }
  }
  
  
  void LCodeGen::DoAddS(LAddS* instr) {
    bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
    Register result = ToRegister(instr->result());
    Register left = ToRegister(instr->left());
    Operand right = ToOperand(instr->right());
    if (can_overflow) {
      __ Adds(result, left, right);
      DeoptimizeIf(vs, instr);
    } else {
      __ Add(result, left, right);
    }
  }
  
  
  void LCodeGen::DoAllocate(LAllocate* instr) {
    class DeferredAllocate: public LDeferredCode {
     public:
      DeferredAllocate(LCodeGen* codegen, LAllocate* instr)
          : LDeferredCode(codegen), instr_(instr) { }
      virtual void Generate() { codegen()->DoDeferredAllocate(instr_); }
      virtual LInstruction* instr() { return instr_; }
     private:
      LAllocate* instr_;
    };
  
    DeferredAllocate* deferred = new(zone()) DeferredAllocate(this, instr);
  
    Register result = ToRegister(instr->result());
    Register temp1 = ToRegister(instr->temp1());
    Register temp2 = ToRegister(instr->temp2());
  
    // Allocate memory for the object.
    AllocationFlags flags = TAG_OBJECT;
    if (instr->hydrogen()->MustAllocateDoubleAligned()) {
      flags = static_cast<AllocationFlags>(flags | DOUBLE_ALIGNMENT);
    }
  
    if (instr->hydrogen()->IsOldPointerSpaceAllocation()) {
      DCHECK(!instr->hydrogen()->IsOldDataSpaceAllocation());
      DCHECK(!instr->hydrogen()->IsNewSpaceAllocation());
      flags = static_cast<AllocationFlags>(flags | PRETENURE_OLD_POINTER_SPACE);
    } else if (instr->hydrogen()->IsOldDataSpaceAllocation()) {
      DCHECK(!instr->hydrogen()->IsNewSpaceAllocation());
      flags = static_cast<AllocationFlags>(flags | PRETENURE_OLD_DATA_SPACE);
    }
  
    if (instr->size()->IsConstantOperand()) {
      int32_t size = ToInteger32(LConstantOperand::cast(instr->size()));
      if (size <= Page::kMaxRegularHeapObjectSize) {
        __ Allocate(size, result, temp1, temp2, deferred->entry(), flags);
      } else {
        __ B(deferred->entry());
      }
    } else {
      Register size = ToRegister32(instr->size());
      __ Sxtw(size.X(), size);
      __ Allocate(size.X(), result, temp1, temp2, deferred->entry(), flags);
    }
  
    __ Bind(deferred->exit());
  
    if (instr->hydrogen()->MustPrefillWithFiller()) {
      Register filler_count = temp1;
      Register filler = temp2;
      Register untagged_result = ToRegister(instr->temp3());
  
      if (instr->size()->IsConstantOperand()) {
        int32_t size = ToInteger32(LConstantOperand::cast(instr->size()));
        __ Mov(filler_count, size / kPointerSize);
      } else {
        __ Lsr(filler_count.W(), ToRegister32(instr->size()), kPointerSizeLog2);
      }
  
      __ Sub(untagged_result, result, kHeapObjectTag);
      __ Mov(filler, Operand(isolate()->factory()->one_pointer_filler_map()));
      __ FillFields(untagged_result, filler_count, filler);
    } else {
      DCHECK(instr->temp3() == NULL);
    }
  }
  
  
  void LCodeGen::DoDeferredAllocate(LAllocate* 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.
    __ Mov(ToRegister(instr->result()), Smi::FromInt(0));
  
    PushSafepointRegistersScope scope(this);
    // We're in a SafepointRegistersScope so we can use any scratch registers.
    Register size = x0;
    if (instr->size()->IsConstantOperand()) {
      __ Mov(size, ToSmi(LConstantOperand::cast(instr->size())));
    } else {
      __ SmiTag(size, ToRegister32(instr->size()).X());
    }
    int flags = AllocateDoubleAlignFlag::encode(
        instr->hydrogen()->MustAllocateDoubleAligned());
    if (instr->hydrogen()->IsOldPointerSpaceAllocation()) {
      DCHECK(!instr->hydrogen()->IsOldDataSpaceAllocation());
      DCHECK(!instr->hydrogen()->IsNewSpaceAllocation());
      flags = AllocateTargetSpace::update(flags, OLD_POINTER_SPACE);
    } else if (instr->hydrogen()->IsOldDataSpaceAllocation()) {
      DCHECK(!instr->hydrogen()->IsNewSpaceAllocation());
      flags = AllocateTargetSpace::update(flags, OLD_DATA_SPACE);
    } else {
      flags = AllocateTargetSpace::update(flags, NEW_SPACE);
    }
    __ Mov(x10, Smi::FromInt(flags));
    __ Push(size, x10);
  
    CallRuntimeFromDeferred(
        Runtime::kAllocateInTargetSpace, 2, instr, instr->context());
    __ StoreToSafepointRegisterSlot(x0, ToRegister(instr->result()));
  }
  
  
  void LCodeGen::DoApplyArguments(LApplyArguments* instr) {
    Register receiver = ToRegister(instr->receiver());
    Register function = ToRegister(instr->function());
    Register length = ToRegister32(instr->length());
  
    Register elements = ToRegister(instr->elements());
    Register scratch = x5;
    DCHECK(receiver.Is(x0));  // Used for parameter count.
    DCHECK(function.Is(x1));  // Required by InvokeFunction.
    DCHECK(ToRegister(instr->result()).Is(x0));
    DCHECK(instr->IsMarkedAsCall());
  
    // Copy the arguments to this function possibly from the
    // adaptor frame below it.
    const uint32_t kArgumentsLimit = 1 * KB;
    __ Cmp(length, kArgumentsLimit);
    DeoptimizeIf(hi, instr);
  
    // Push the receiver and use the register to keep the original
    // number of arguments.
    __ Push(receiver);
    Register argc = receiver;
    receiver = NoReg;
    __ Sxtw(argc, length);
    // The arguments are at a one pointer size offset from elements.
    __ Add(elements, elements, 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.
    __ Cbz(length, &invoke);
    __ Bind(&loop);
    __ Ldr(scratch, MemOperand(elements, length, SXTW, kPointerSizeLog2));
    __ Push(scratch);
    __ Subs(length, length, 1);
    __ B(ne, &loop);
  
    __ Bind(&invoke);
    DCHECK(instr->HasPointerMap());
    LPointerMap* pointers = instr->pointer_map();
    SafepointGenerator safepoint_generator(this, pointers, Safepoint::kLazyDeopt);
    // The number of arguments is stored in argc (receiver) which is x0, as
    // expected by InvokeFunction.
    ParameterCount actual(argc);
    __ InvokeFunction(function, actual, CALL_FUNCTION, safepoint_generator);
  }
  
  
  void LCodeGen::DoArgumentsElements(LArgumentsElements* instr) {
    // We push some arguments and they will be pop in an other block. We can't
    // trust that jssp references the end of the stack slots until the end of
    // the function.
    inlined_arguments_ = true;
    Register result = ToRegister(instr->result());
  
    if (instr->hydrogen()->from_inlined()) {
      // When we are inside an inlined function, the arguments are the last things
      // that have been pushed on the stack. Therefore the arguments array can be
      // accessed directly from jssp.
      // However in the normal case, it is accessed via fp but there are two words
      // on the stack between fp and the arguments (the saved lr and fp) and the
      // LAccessArgumentsAt implementation take that into account.
      // In the inlined case we need to subtract the size of 2 words to jssp to
      // get a pointer which will work well with LAccessArgumentsAt.
      DCHECK(masm()->StackPointer().Is(jssp));
      __ Sub(result, jssp, 2 * kPointerSize);
    } else {
      DCHECK(instr->temp() != NULL);
      Register previous_fp = ToRegister(instr->temp());
  
      __ Ldr(previous_fp,
             MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
      __ Ldr(result,
             MemOperand(previous_fp, StandardFrameConstants::kContextOffset));
      __ Cmp(result, Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
      __ Csel(result, fp, previous_fp, ne);
    }
  }
  
  
  void LCodeGen::DoArgumentsLength(LArgumentsLength* instr) {
    Register elements = ToRegister(instr->elements());
    Register result = ToRegister32(instr->result());
    Label done;
  
    // If no arguments adaptor frame the number of arguments is fixed.
    __ Cmp(fp, elements);
    __ Mov(result, scope()->num_parameters());
    __ B(eq, &done);
  
    // Arguments adaptor frame present. Get argument length from there.
    __ Ldr(result.X(), MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
    __ Ldr(result,
           UntagSmiMemOperand(result.X(),
                              ArgumentsAdaptorFrameConstants::kLengthOffset));
  
    // Argument length is in result register.
    __ 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: __ Fadd(result, left, right); break;
      case Token::SUB: __ Fsub(result, left, right); break;
      case Token::MUL: __ Fmul(result, left, right); break;
      case Token::DIV: __ Fdiv(result, left, right); break;
      case Token::MOD: {
        // The ECMA-262 remainder operator is the remainder from a truncating
        // (round-towards-zero) division. Note that this differs from IEEE-754.
        //
        // TODO(jbramley): See if it's possible to do this inline, rather than by
        // calling a helper function. With frintz (to produce the intermediate
        // quotient) and fmsub (to calculate the remainder without loss of
        // precision), it should be possible. However, we would need support for
        // fdiv in round-towards-zero mode, and the ARM64 simulator doesn't
        // support that yet.
        DCHECK(left.Is(d0));
        DCHECK(right.Is(d1));
        __ CallCFunction(
            ExternalReference::mod_two_doubles_operation(isolate()),
            0, 2);
        DCHECK(result.Is(d0));
        break;
      }
      default:
        UNREACHABLE();
        break;
    }
  }
  
  
  void LCodeGen::DoArithmeticT(LArithmeticT* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->left()).is(x1));
    DCHECK(ToRegister(instr->right()).is(x0));
    DCHECK(ToRegister(instr->result()).is(x0));
  
    Handle<Code> code =
        CodeFactory::BinaryOpIC(isolate(), instr->op(), NO_OVERWRITE).code();
    CallCode(code, RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoBitI(LBitI* instr) {
    Register result = ToRegister32(instr->result());
    Register left = ToRegister32(instr->left());
    Operand right = ToShiftedRightOperand32(instr->right(), instr);
  
    switch (instr->op()) {
      case Token::BIT_AND: __ And(result, left, right); break;
      case Token::BIT_OR:  __ Orr(result, left, right); break;
      case Token::BIT_XOR: __ Eor(result, left, right); break;
      default:
        UNREACHABLE();
        break;
    }
  }
  
  
  void LCodeGen::DoBitS(LBitS* instr) {
    Register result = ToRegister(instr->result());
    Register left = ToRegister(instr->left());
    Operand right = ToOperand(instr->right());
  
    switch (instr->op()) {
      case Token::BIT_AND: __ And(result, left, right); break;
      case Token::BIT_OR:  __ Orr(result, left, right); break;
      case Token::BIT_XOR: __ Eor(result, left, right); break;
      default:
        UNREACHABLE();
        break;
    }
  }
  
  
  void LCodeGen::DoBoundsCheck(LBoundsCheck *instr) {
    Condition cond = instr->hydrogen()->allow_equality() ? hi : hs;
    DCHECK(instr->hydrogen()->index()->representation().IsInteger32());
    DCHECK(instr->hydrogen()->length()->representation().IsInteger32());
    if (instr->index()->IsConstantOperand()) {
      Operand index = ToOperand32(instr->index());
      Register length = ToRegister32(instr->length());
      __ Cmp(length, index);
      cond = CommuteCondition(cond);
    } else {
      Register index = ToRegister32(instr->index());
      Operand length = ToOperand32(instr->length());
      __ Cmp(index, length);
    }
    if (FLAG_debug_code && instr->hydrogen()->skip_check()) {
      __ Assert(NegateCondition(cond), kEliminatedBoundsCheckFailed);
    } else {
      DeoptimizeIf(cond, instr);
    }
  }
  
  
  void LCodeGen::DoBranch(LBranch* instr) {
    Representation r = instr->hydrogen()->value()->representation();
    Label* true_label = instr->TrueLabel(chunk_);
    Label* false_label = instr->FalseLabel(chunk_);
  
    if (r.IsInteger32()) {
      DCHECK(!info()->IsStub());
      EmitCompareAndBranch(instr, ne, ToRegister32(instr->value()), 0);
    } else if (r.IsSmi()) {
      DCHECK(!info()->IsStub());
      STATIC_ASSERT(kSmiTag == 0);
      EmitCompareAndBranch(instr, ne, ToRegister(instr->value()), 0);
    } else if (r.IsDouble()) {
      DoubleRegister value = ToDoubleRegister(instr->value());
      // Test the double value. Zero and NaN are false.
      EmitBranchIfNonZeroNumber(instr, value, double_scratch());
    } else {
      DCHECK(r.IsTagged());
      Register value = ToRegister(instr->value());
      HType type = instr->hydrogen()->value()->type();
  
      if (type.IsBoolean()) {
        DCHECK(!info()->IsStub());
        __ CompareRoot(value, Heap::kTrueValueRootIndex);
        EmitBranch(instr, eq);
      } else if (type.IsSmi()) {
        DCHECK(!info()->IsStub());
        EmitCompareAndBranch(instr, ne, value, Smi::FromInt(0));
      } else if (type.IsJSArray()) {
        DCHECK(!info()->IsStub());
        EmitGoto(instr->TrueDestination(chunk()));
      } else if (type.IsHeapNumber()) {
        DCHECK(!info()->IsStub());
        __ Ldr(double_scratch(), FieldMemOperand(value,
                                                 HeapNumber::kValueOffset));
        // Test the double value. Zero and NaN are false.
        EmitBranchIfNonZeroNumber(instr, double_scratch(), double_scratch());
      } else if (type.IsString()) {
        DCHECK(!info()->IsStub());
        Register temp = ToRegister(instr->temp1());
        __ Ldr(temp, FieldMemOperand(value, String::kLengthOffset));
        EmitCompareAndBranch(instr, ne, temp, 0);
      } else {
        ToBooleanStub::Types expected = instr->hydrogen()->expected_input_types();
        // Avoid deopts in the case where we've never executed this path before.
        if (expected.IsEmpty()) expected = ToBooleanStub::Types::Generic();
  
        if (expected.Contains(ToBooleanStub::UNDEFINED)) {
          // undefined -> false.
          __ JumpIfRoot(
              value, Heap::kUndefinedValueRootIndex, false_label);
        }
  
        if (expected.Contains(ToBooleanStub::BOOLEAN)) {
          // Boolean -> its value.
          __ JumpIfRoot(
              value, Heap::kTrueValueRootIndex, true_label);
          __ JumpIfRoot(
              value, Heap::kFalseValueRootIndex, false_label);
        }
  
        if (expected.Contains(ToBooleanStub::NULL_TYPE)) {
          // 'null' -> false.
          __ JumpIfRoot(
              value, Heap::kNullValueRootIndex, false_label);
        }
  
        if (expected.Contains(ToBooleanStub::SMI)) {
          // Smis: 0 -> false, all other -> true.
          DCHECK(Smi::FromInt(0) == 0);
          __ Cbz(value, false_label);
          __ JumpIfSmi(value, true_label);
        } else if (expected.NeedsMap()) {
          // If we need a map later and have a smi, deopt.
          DeoptimizeIfSmi(value, instr);
        }
  
        Register map = NoReg;
        Register scratch = NoReg;
  
        if (expected.NeedsMap()) {
          DCHECK((instr->temp1() != NULL) && (instr->temp2() != NULL));
          map = ToRegister(instr->temp1());
          scratch = ToRegister(instr->temp2());
  
          __ Ldr(map, FieldMemOperand(value, HeapObject::kMapOffset));
  
          if (expected.CanBeUndetectable()) {
            // Undetectable -> false.
            __ Ldrb(scratch, FieldMemOperand(map, Map::kBitFieldOffset));
            __ TestAndBranchIfAnySet(
                scratch, 1 << Map::kIsUndetectable, false_label);
          }
        }
  
        if (expected.Contains(ToBooleanStub::SPEC_OBJECT)) {
          // spec object -> true.
          __ CompareInstanceType(map, scratch, FIRST_SPEC_OBJECT_TYPE);
          __ B(ge, true_label);
        }
  
        if (expected.Contains(ToBooleanStub::STRING)) {
          // String value -> false iff empty.
          Label not_string;
          __ CompareInstanceType(map, scratch, FIRST_NONSTRING_TYPE);
          __ B(ge, &not_string);
          __ Ldr(scratch, FieldMemOperand(value, String::kLengthOffset));
          __ Cbz(scratch, false_label);
          __ B(true_label);
          __ Bind(&not_string);
        }
  
        if (expected.Contains(ToBooleanStub::SYMBOL)) {
          // Symbol value -> true.
          __ CompareInstanceType(map, scratch, SYMBOL_TYPE);
          __ B(eq, true_label);
        }
  
        if (expected.Contains(ToBooleanStub::HEAP_NUMBER)) {
          Label not_heap_number;
          __ JumpIfNotRoot(map, Heap::kHeapNumberMapRootIndex, &not_heap_number);
  
          __ Ldr(double_scratch(),
                 FieldMemOperand(value, HeapNumber::kValueOffset));
          __ Fcmp(double_scratch(), 0.0);
          // If we got a NaN (overflow bit is set), jump to the false branch.
          __ B(vs, false_label);
          __ B(eq, false_label);
          __ B(true_label);
          __ Bind(&not_heap_number);
        }
  
        if (!expected.IsGeneric()) {
          // We've seen something for the first time -> deopt.
          // This can only happen if we are not generic already.
          Deoptimize(instr);
        }
      }
    }
  }
  
  
  void LCodeGen::CallKnownFunction(Handle<JSFunction> function,
                                   int formal_parameter_count,
                                   int arity,
                                   LInstruction* instr,
                                   Register function_reg) {
    bool dont_adapt_arguments =
        formal_parameter_count == SharedFunctionInfo::kDontAdaptArgumentsSentinel;
    bool can_invoke_directly =
        dont_adapt_arguments || formal_parameter_count == arity;
  
    // The function interface relies on the following register assignments.
    DCHECK(function_reg.Is(x1) || function_reg.IsNone());
    Register arity_reg = x0;
  
    LPointerMap* pointers = instr->pointer_map();
  
    // If necessary, load the function object.
    if (function_reg.IsNone()) {
      function_reg = x1;
      __ LoadObject(function_reg, function);
    }
  
    if (FLAG_debug_code) {
      Label is_not_smi;
      // Try to confirm that function_reg (x1) is a tagged pointer.
      __ JumpIfNotSmi(function_reg, &is_not_smi);
      __ Abort(kExpectedFunctionObject);
      __ Bind(&is_not_smi);
    }
  
    if (can_invoke_directly) {
      // Change context.
      __ Ldr(cp, FieldMemOperand(function_reg, JSFunction::kContextOffset));
  
      // Set the arguments count if adaption is not needed. Assumes that x0 is
      // available to write to at this point.
      if (dont_adapt_arguments) {
        __ Mov(arity_reg, arity);
      }
  
      // Invoke function.
      __ Ldr(x10, FieldMemOperand(function_reg, JSFunction::kCodeEntryOffset));
      __ Call(x10);
  
      // Set up deoptimization.
      RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
    } else {
      SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
      ParameterCount count(arity);
      ParameterCount expected(formal_parameter_count);
      __ InvokeFunction(function_reg, expected, count, CALL_FUNCTION, generator);
    }
  }
  
  
  void LCodeGen::DoTailCallThroughMegamorphicCache(
      LTailCallThroughMegamorphicCache* instr) {
    Register receiver = ToRegister(instr->receiver());
    Register name = ToRegister(instr->name());
    DCHECK(receiver.is(LoadDescriptor::ReceiverRegister()));
    DCHECK(name.is(LoadDescriptor::NameRegister()));
    DCHECK(receiver.is(x1));
    DCHECK(name.is(x2));
  
    Register scratch = x3;
    Register extra = x4;
    Register extra2 = x5;
    Register extra3 = x6;
  
    // Important for the tail-call.
    bool must_teardown_frame = NeedsEagerFrame();
  
    // The probe will tail call to a handler if found.
    isolate()->stub_cache()->GenerateProbe(masm(), instr->hydrogen()->flags(),
                                           must_teardown_frame, receiver, name,
                                           scratch, extra, extra2, extra3);
  
    // Tail call to miss if we ended up here.
    if (must_teardown_frame) __ LeaveFrame(StackFrame::INTERNAL);
    LoadIC::GenerateMiss(masm());
  }
  
  
  void LCodeGen::DoCallWithDescriptor(LCallWithDescriptor* instr) {
    DCHECK(instr->IsMarkedAsCall());
    DCHECK(ToRegister(instr->result()).Is(x0));
  
    LPointerMap* pointers = instr->pointer_map();
    SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
  
    if (instr->target()->IsConstantOperand()) {
      LConstantOperand* target = LConstantOperand::cast(instr->target());
      Handle<Code> code = Handle<Code>::cast(ToHandle(target));
      generator.BeforeCall(__ CallSize(code, RelocInfo::CODE_TARGET));
      // TODO(all): on ARM we use a call descriptor to specify a storage mode
      // but on ARM64 we only have one storage mode so it isn't necessary. Check
      // this understanding is correct.
      __ Call(code, RelocInfo::CODE_TARGET, TypeFeedbackId::None());
    } else {
      DCHECK(instr->target()->IsRegister());
      Register target = ToRegister(instr->target());
      generator.BeforeCall(__ CallSize(target));
      __ Add(target, target, Code::kHeaderSize - kHeapObjectTag);
      __ Call(target);
    }
    generator.AfterCall();
    after_push_argument_ = false;
  }
  
  
  void LCodeGen::DoCallJSFunction(LCallJSFunction* instr) {
    DCHECK(instr->IsMarkedAsCall());
    DCHECK(ToRegister(instr->function()).is(x1));
  
    if (instr->hydrogen()->pass_argument_count()) {
      __ Mov(x0, Operand(instr->arity()));
    }
  
    // Change context.
    __ Ldr(cp, FieldMemOperand(x1, JSFunction::kContextOffset));
  
    // Load the code entry address
    __ Ldr(x10, FieldMemOperand(x1, JSFunction::kCodeEntryOffset));
    __ Call(x10);
  
    RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT);
    after_push_argument_ = false;
  }
  
  
  void LCodeGen::DoCallRuntime(LCallRuntime* instr) {
    CallRuntime(instr->function(), instr->arity(), instr);
    after_push_argument_ = false;
  }
  
  
  void LCodeGen::DoCallStub(LCallStub* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->result()).is(x0));
    switch (instr->hydrogen()->major_key()) {
      case CodeStub::RegExpExec: {
        RegExpExecStub stub(isolate());
        CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
        break;
      }
      case CodeStub::SubString: {
        SubStringStub stub(isolate());
        CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
        break;
      }
      case CodeStub::StringCompare: {
        StringCompareStub stub(isolate());
        CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
        break;
      }
      default:
        UNREACHABLE();
    }
    after_push_argument_ = false;
  }
  
  
  void LCodeGen::DoUnknownOSRValue(LUnknownOSRValue* instr) {
    GenerateOsrPrologue();
  }
  
  
  void LCodeGen::DoDeferredInstanceMigration(LCheckMaps* instr, Register object) {
    Register temp = ToRegister(instr->temp());
    {
      PushSafepointRegistersScope scope(this);
      __ Push(object);
      __ Mov(cp, 0);
      __ CallRuntimeSaveDoubles(Runtime::kTryMigrateInstance);
      RecordSafepointWithRegisters(
          instr->pointer_map(), 1, Safepoint::kNoLazyDeopt);
      __ StoreToSafepointRegisterSlot(x0, temp);
    }
    DeoptimizeIfSmi(temp, instr);
  }
  
  
  void LCodeGen::DoCheckMaps(LCheckMaps* instr) {
    class DeferredCheckMaps: public LDeferredCode {
     public:
      DeferredCheckMaps(LCodeGen* codegen, LCheckMaps* instr, Register object)
          : LDeferredCode(codegen), instr_(instr), object_(object) {
        SetExit(check_maps());
      }
      virtual void Generate() {
        codegen()->DoDeferredInstanceMigration(instr_, object_);
      }
      Label* check_maps() { return &check_maps_; }
      virtual LInstruction* instr() { return instr_; }
     private:
      LCheckMaps* instr_;
      Label check_maps_;
      Register object_;
    };
  
    if (instr->hydrogen()->IsStabilityCheck()) {
      const UniqueSet<Map>* maps = instr->hydrogen()->maps();
      for (int i = 0; i < maps->size(); ++i) {
        AddStabilityDependency(maps->at(i).handle());
      }
      return;
    }
  
    Register object = ToRegister(instr->value());
    Register map_reg = ToRegister(instr->temp());
  
    __ Ldr(map_reg, FieldMemOperand(object, HeapObject::kMapOffset));
  
    DeferredCheckMaps* deferred = NULL;
    if (instr->hydrogen()->HasMigrationTarget()) {
      deferred = new(zone()) DeferredCheckMaps(this, instr, object);
      __ Bind(deferred->check_maps());
    }
  
    const UniqueSet<Map>* maps = instr->hydrogen()->maps();
    Label success;
    for (int i = 0; i < maps->size() - 1; i++) {
      Handle<Map> map = maps->at(i).handle();
      __ CompareMap(map_reg, map);
      __ B(eq, &success);
    }
    Handle<Map> map = maps->at(maps->size() - 1).handle();
    __ CompareMap(map_reg, map);
  
    // We didn't match a map.
    if (instr->hydrogen()->HasMigrationTarget()) {
      __ B(ne, deferred->entry());
    } else {
      DeoptimizeIf(ne, instr);
    }
  
    __ Bind(&success);
  }
  
  
  void LCodeGen::DoCheckNonSmi(LCheckNonSmi* instr) {
    if (!instr->hydrogen()->value()->type().IsHeapObject()) {
      DeoptimizeIfSmi(ToRegister(instr->value()), instr);
    }
  }
  
  
  void LCodeGen::DoCheckSmi(LCheckSmi* instr) {
    Register value = ToRegister(instr->value());
    DCHECK(!instr->result() || ToRegister(instr->result()).Is(value));
    DeoptimizeIfNotSmi(value, instr);
  }
  
  
  void LCodeGen::DoCheckInstanceType(LCheckInstanceType* instr) {
    Register input = ToRegister(instr->value());
    Register scratch = ToRegister(instr->temp());
  
    __ Ldr(scratch, FieldMemOperand(input, HeapObject::kMapOffset));
    __ Ldrb(scratch, FieldMemOperand(scratch, Map::kInstanceTypeOffset));
  
    if (instr->hydrogen()->is_interval_check()) {
      InstanceType first, last;
      instr->hydrogen()->GetCheckInterval(&first, &last);
  
      __ Cmp(scratch, first);
      if (first == last) {
        // If there is only one type in the interval check for equality.
        DeoptimizeIf(ne, instr);
      } else if (last == LAST_TYPE) {
        // We don't need to compare with the higher bound of the interval.
        DeoptimizeIf(lo, instr);
      } else {
        // If we are below the lower bound, set the C flag and clear the Z flag
        // to force a deopt.
        __ Ccmp(scratch, last, CFlag, hs);
        DeoptimizeIf(hi, instr);
      }
    } else {
      uint8_t mask;
      uint8_t tag;
      instr->hydrogen()->GetCheckMaskAndTag(&mask, &tag);
  
      if (base::bits::IsPowerOfTwo32(mask)) {
        DCHECK((tag == 0) || (tag == mask));
        if (tag == 0) {
          DeoptimizeIfBitSet(scratch, MaskToBit(mask), instr);
        } else {
          DeoptimizeIfBitClear(scratch, MaskToBit(mask), instr);
        }
      } else {
        if (tag == 0) {
          __ Tst(scratch, mask);
        } else {
          __ And(scratch, scratch, mask);
          __ Cmp(scratch, tag);
        }
        DeoptimizeIf(ne, instr);
      }
    }
  }
  
  
  void LCodeGen::DoClampDToUint8(LClampDToUint8* instr) {
    DoubleRegister input = ToDoubleRegister(instr->unclamped());
    Register result = ToRegister32(instr->result());
    __ ClampDoubleToUint8(result, input, double_scratch());
  }
  
  
  void LCodeGen::DoClampIToUint8(LClampIToUint8* instr) {
    Register input = ToRegister32(instr->unclamped());
    Register result = ToRegister32(instr->result());
    __ ClampInt32ToUint8(result, input);
  }
  
  
  void LCodeGen::DoClampTToUint8(LClampTToUint8* instr) {
    Register input = ToRegister(instr->unclamped());
    Register result = ToRegister32(instr->result());
    Label done;
  
    // Both smi and heap number cases are handled.
    Label is_not_smi;
    __ JumpIfNotSmi(input, &is_not_smi);
    __ SmiUntag(result.X(), input);
    __ ClampInt32ToUint8(result);
    __ B(&done);
  
    __ Bind(&is_not_smi);
  
    // Check for heap number.
    Label is_heap_number;
    __ JumpIfHeapNumber(input, &is_heap_number);
  
    // Check for undefined. Undefined is coverted to zero for clamping conversion.
    DeoptimizeIfNotRoot(input, Heap::kUndefinedValueRootIndex, instr);
    __ Mov(result, 0);
    __ B(&done);
  
    // Heap number case.
    __ Bind(&is_heap_number);
    DoubleRegister dbl_scratch = double_scratch();
    DoubleRegister dbl_scratch2 = ToDoubleRegister(instr->temp1());
    __ Ldr(dbl_scratch, FieldMemOperand(input, HeapNumber::kValueOffset));
    __ ClampDoubleToUint8(result, dbl_scratch, dbl_scratch2);
  
    __ Bind(&done);
  }
  
  
  void LCodeGen::DoDoubleBits(LDoubleBits* instr) {
    DoubleRegister value_reg = ToDoubleRegister(instr->value());
    Register result_reg = ToRegister(instr->result());
    if (instr->hydrogen()->bits() == HDoubleBits::HIGH) {
      __ Fmov(result_reg, value_reg);
      __ Lsr(result_reg, result_reg, 32);
    } else {
      __ Fmov(result_reg.W(), value_reg.S());
    }
  }
  
  
  void LCodeGen::DoConstructDouble(LConstructDouble* instr) {
    Register hi_reg = ToRegister(instr->hi());
    Register lo_reg = ToRegister(instr->lo());
    DoubleRegister result_reg = ToDoubleRegister(instr->result());
  
    // Insert the least significant 32 bits of hi_reg into the most significant
    // 32 bits of lo_reg, and move to a floating point register.
    __ Bfi(lo_reg, hi_reg, 32, 32);
    __ Fmov(result_reg, lo_reg);
  }
  
  
  void LCodeGen::DoClassOfTestAndBranch(LClassOfTestAndBranch* instr) {
    Handle<String> class_name = instr->hydrogen()->class_name();
    Label* true_label = instr->TrueLabel(chunk_);
    Label* false_label = instr->FalseLabel(chunk_);
    Register input = ToRegister(instr->value());
    Register scratch1 = ToRegister(instr->temp1());
    Register scratch2 = ToRegister(instr->temp2());
  
    __ JumpIfSmi(input, false_label);
  
    Register map = scratch2;
    if (String::Equals(isolate()->factory()->Function_string(), class_name)) {
      // Assuming the following assertions, we can use the same compares to test
      // for both being a function type and being in the object type range.
      STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
      STATIC_ASSERT(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE ==
                    FIRST_SPEC_OBJECT_TYPE + 1);
      STATIC_ASSERT(LAST_NONCALLABLE_SPEC_OBJECT_TYPE ==
                    LAST_SPEC_OBJECT_TYPE - 1);
      STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
  
      // We expect CompareObjectType to load the object instance type in scratch1.
      __ CompareObjectType(input, map, scratch1, FIRST_SPEC_OBJECT_TYPE);
      __ B(lt, false_label);
      __ B(eq, true_label);
      __ Cmp(scratch1, LAST_SPEC_OBJECT_TYPE);
      __ B(eq, true_label);
    } else {
      __ IsObjectJSObjectType(input, map, scratch1, false_label);
    }
  
    // Now we are in the FIRST-LAST_NONCALLABLE_SPEC_OBJECT_TYPE range.
    // Check if the constructor in the map is a function.
    __ Ldr(scratch1, FieldMemOperand(map, Map::kConstructorOffset));
  
    // Objects with a non-function constructor have class 'Object'.
    if (String::Equals(class_name, isolate()->factory()->Object_string())) {
      __ JumpIfNotObjectType(
          scratch1, scratch2, scratch2, JS_FUNCTION_TYPE, true_label);
    } else {
      __ JumpIfNotObjectType(
          scratch1, scratch2, scratch2, JS_FUNCTION_TYPE, false_label);
    }
  
    // The constructor function is in scratch1. Get its instance class name.
    __ Ldr(scratch1,
           FieldMemOperand(scratch1, JSFunction::kSharedFunctionInfoOffset));
    __ Ldr(scratch1,
           FieldMemOperand(scratch1,
                           SharedFunctionInfo::kInstanceClassNameOffset));
  
    // The class name we are testing against is internalized since it's a literal.
    // The name in the constructor is internalized because of the way the context
    // is booted. This routine isn't expected to work for random API-created
    // classes and it doesn't have to because you can't access it with natives
    // syntax. Since both sides are internalized it is sufficient to use an
    // identity comparison.
    EmitCompareAndBranch(instr, eq, scratch1, Operand(class_name));
  }
  
  
  void LCodeGen::DoCmpHoleAndBranchD(LCmpHoleAndBranchD* instr) {
    DCHECK(instr->hydrogen()->representation().IsDouble());
    FPRegister object = ToDoubleRegister(instr->object());
    Register temp = ToRegister(instr->temp());
  
    // If we don't have a NaN, we don't have the hole, so branch now to avoid the
    // (relatively expensive) hole-NaN check.
    __ Fcmp(object, object);
    __ B(vc, instr->FalseLabel(chunk_));
  
    // We have a NaN, but is it the hole?
    __ Fmov(temp, object);
    EmitCompareAndBranch(instr, eq, temp, kHoleNanInt64);
  }
  
  
  void LCodeGen::DoCmpHoleAndBranchT(LCmpHoleAndBranchT* instr) {
    DCHECK(instr->hydrogen()->representation().IsTagged());
    Register object = ToRegister(instr->object());
  
    EmitBranchIfRoot(instr, object, Heap::kTheHoleValueRootIndex);
  }
  
  
  void LCodeGen::DoCmpMapAndBranch(LCmpMapAndBranch* instr) {
    Register value = ToRegister(instr->value());
    Register map = ToRegister(instr->temp());
  
    __ Ldr(map, FieldMemOperand(value, HeapObject::kMapOffset));
    EmitCompareAndBranch(instr, eq, map, Operand(instr->map()));
  }
  
  
  void LCodeGen::DoCompareMinusZeroAndBranch(LCompareMinusZeroAndBranch* instr) {
    Representation rep = instr->hydrogen()->value()->representation();
    DCHECK(!rep.IsInteger32());
    Register scratch = ToRegister(instr->temp());
  
    if (rep.IsDouble()) {
      __ JumpIfMinusZero(ToDoubleRegister(instr->value()),
                         instr->TrueLabel(chunk()));
    } else {
      Register value = ToRegister(instr->value());
      __ JumpIfNotHeapNumber(value, instr->FalseLabel(chunk()), DO_SMI_CHECK);
      __ Ldr(scratch, FieldMemOperand(value, HeapNumber::kValueOffset));
      __ JumpIfMinusZero(scratch, instr->TrueLabel(chunk()));
    }
    EmitGoto(instr->FalseDestination(chunk()));
  }
  
  
  void LCodeGen::DoCompareNumericAndBranch(LCompareNumericAndBranch* instr) {
    LOperand* left = instr->left();
    LOperand* right = instr->right();
    bool is_unsigned =
        instr->hydrogen()->left()->CheckFlag(HInstruction::kUint32) ||
        instr->hydrogen()->right()->CheckFlag(HInstruction::kUint32);
    Condition cond = TokenToCondition(instr->op(), is_unsigned);
  
    if (left->IsConstantOperand() && right->IsConstantOperand()) {
      // We can statically evaluate the comparison.
      double left_val = ToDouble(LConstantOperand::cast(left));
      double right_val = ToDouble(LConstantOperand::cast(right));
      int next_block = EvalComparison(instr->op(), left_val, right_val) ?
          instr->TrueDestination(chunk_) : instr->FalseDestination(chunk_);
      EmitGoto(next_block);
    } else {
      if (instr->is_double()) {
        __ Fcmp(ToDoubleRegister(left), ToDoubleRegister(right));
  
        // If a NaN is involved, i.e. the result is unordered (V set),
        // jump to false block label.
        __ B(vs, instr->FalseLabel(chunk_));
        EmitBranch(instr, cond);
      } else {
        if (instr->hydrogen_value()->representation().IsInteger32()) {
          if (right->IsConstantOperand()) {
            EmitCompareAndBranch(instr, cond, ToRegister32(left),
                                 ToOperand32(right));
          } else {
            // Commute the operands and the condition.
            EmitCompareAndBranch(instr, CommuteCondition(cond),
                                 ToRegister32(right), ToOperand32(left));
          }
        } else {
          DCHECK(instr->hydrogen_value()->representation().IsSmi());
          if (right->IsConstantOperand()) {
            int32_t value = ToInteger32(LConstantOperand::cast(right));
            EmitCompareAndBranch(instr,
                                 cond,
                                 ToRegister(left),
                                 Operand(Smi::FromInt(value)));
          } else if (left->IsConstantOperand()) {
            // Commute the operands and the condition.
            int32_t value = ToInteger32(LConstantOperand::cast(left));
            EmitCompareAndBranch(instr,
                                 CommuteCondition(cond),
                                 ToRegister(right),
                                 Operand(Smi::FromInt(value)));
          } else {
            EmitCompareAndBranch(instr,
                                 cond,
                                 ToRegister(left),
                                 ToRegister(right));
          }
        }
      }
    }
  }
  
  
  void LCodeGen::DoCmpObjectEqAndBranch(LCmpObjectEqAndBranch* instr) {
    Register left = ToRegister(instr->left());
    Register right = ToRegister(instr->right());
    EmitCompareAndBranch(instr, eq, left, right);
  }
  
  
  void LCodeGen::DoCmpT(LCmpT* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    Token::Value op = instr->op();
    Condition cond = TokenToCondition(op, false);
  
    DCHECK(ToRegister(instr->left()).Is(x1));
    DCHECK(ToRegister(instr->right()).Is(x0));
    Handle<Code> ic = CodeFactory::CompareIC(isolate(), op).code();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
    // Signal that we don't inline smi code before this stub.
    InlineSmiCheckInfo::EmitNotInlined(masm());
  
    // Return true or false depending on CompareIC result.
    // This instruction is marked as call. We can clobber any register.
    DCHECK(instr->IsMarkedAsCall());
    __ LoadTrueFalseRoots(x1, x2);
    __ Cmp(x0, 0);
    __ Csel(ToRegister(instr->result()), x1, x2, cond);
  }
  
  
  void LCodeGen::DoConstantD(LConstantD* instr) {
    DCHECK(instr->result()->IsDoubleRegister());
    DoubleRegister result = ToDoubleRegister(instr->result());
    if (instr->value() == 0) {
      if (copysign(1.0, instr->value()) == 1.0) {
        __ Fmov(result, fp_zero);
      } else {
        __ Fneg(result, fp_zero);
      }
    } else {
      __ Fmov(result, instr->value());
    }
  }
  
  
  void LCodeGen::DoConstantE(LConstantE* instr) {
    __ Mov(ToRegister(instr->result()), Operand(instr->value()));
  }
  
  
  void LCodeGen::DoConstantI(LConstantI* instr) {
    DCHECK(is_int32(instr->value()));
    // Cast the value here to ensure that the value isn't sign extended by the
    // implicit Operand constructor.
    __ Mov(ToRegister32(instr->result()), static_cast<uint32_t>(instr->value()));
  }
  
  
  void LCodeGen::DoConstantS(LConstantS* instr) {
    __ Mov(ToRegister(instr->result()), Operand(instr->value()));
  }
  
  
  void LCodeGen::DoConstantT(LConstantT* instr) {
    Handle<Object> object = instr->value(isolate());
    AllowDeferredHandleDereference smi_check;
    __ LoadObject(ToRegister(instr->result()), object);
  }
  
  
  void LCodeGen::DoContext(LContext* instr) {
    // If there is a non-return use, the context must be moved to a register.
    Register result = ToRegister(instr->result());
    if (info()->IsOptimizing()) {
      __ Ldr(result, MemOperand(fp, StandardFrameConstants::kContextOffset));
    } else {
      // If there is no frame, the context must be in cp.
      DCHECK(result.is(cp));
    }
  }
  
  
  void LCodeGen::DoCheckValue(LCheckValue* instr) {
    Register reg = ToRegister(instr->value());
    Handle<HeapObject> object = instr->hydrogen()->object().handle();
    AllowDeferredHandleDereference smi_check;
    if (isolate()->heap()->InNewSpace(*object)) {
      UseScratchRegisterScope temps(masm());
      Register temp = temps.AcquireX();
      Handle<Cell> cell = isolate()->factory()->NewCell(object);
      __ Mov(temp, Operand(Handle<Object>(cell)));
      __ Ldr(temp, FieldMemOperand(temp, Cell::kValueOffset));
      __ Cmp(reg, temp);
    } else {
      __ Cmp(reg, Operand(object));
    }
    DeoptimizeIf(ne, instr);
  }
  
  
  void LCodeGen::DoLazyBailout(LLazyBailout* instr) {
    last_lazy_deopt_pc_ = masm()->pc_offset();
    DCHECK(instr->HasEnvironment());
    LEnvironment* env = instr->environment();
    RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
    safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
  }
  
  
  void LCodeGen::DoDateField(LDateField* instr) {
    Register object = ToRegister(instr->date());
    Register result = ToRegister(instr->result());
    Register temp1 = x10;
    Register temp2 = x11;
    Smi* index = instr->index();
    Label runtime, done;
  
    DCHECK(object.is(result) && object.Is(x0));
    DCHECK(instr->IsMarkedAsCall());
  
    DeoptimizeIfSmi(object, instr);
    __ CompareObjectType(object, temp1, temp1, JS_DATE_TYPE);
    DeoptimizeIf(ne, instr);
  
    if (index->value() == 0) {
      __ Ldr(result, FieldMemOperand(object, JSDate::kValueOffset));
    } else {
      if (index->value() < JSDate::kFirstUncachedField) {
        ExternalReference stamp = ExternalReference::date_cache_stamp(isolate());
        __ Mov(temp1, Operand(stamp));
        __ Ldr(temp1, MemOperand(temp1));
        __ Ldr(temp2, FieldMemOperand(object, JSDate::kCacheStampOffset));
        __ Cmp(temp1, temp2);
        __ B(ne, &runtime);
        __ Ldr(result, FieldMemOperand(object, JSDate::kValueOffset +
                                               kPointerSize * index->value()));
        __ B(&done);
      }
  
      __ Bind(&runtime);
      __ Mov(x1, Operand(index));
      __ CallCFunction(ExternalReference::get_date_field_function(isolate()), 2);
    }
  
    __ Bind(&done);
  }
  
  
  void LCodeGen::DoDeoptimize(LDeoptimize* instr) {
    Deoptimizer::BailoutType type = instr->hydrogen()->type();
    // TODO(danno): Stubs expect all deopts to be lazy for historical reasons (the
    // needed return address), even though the implementation of LAZY and EAGER is
    // now identical. When LAZY is eventually completely folded into EAGER, remove
    // the special case below.
    if (info()->IsStub() && (type == Deoptimizer::EAGER)) {
      type = Deoptimizer::LAZY;
    }
  
    Deoptimize(instr, &type, instr->hydrogen()->reason());
  }
  
  
  void LCodeGen::DoDivByPowerOf2I(LDivByPowerOf2I* instr) {
    Register dividend = ToRegister32(instr->dividend());
    int32_t divisor = instr->divisor();
    Register result = ToRegister32(instr->result());
    DCHECK(divisor == kMinInt || base::bits::IsPowerOfTwo32(Abs(divisor)));
    DCHECK(!result.is(dividend));
  
    // Check for (0 / -x) that will produce negative zero.
    HDiv* hdiv = instr->hydrogen();
    if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
      DeoptimizeIfZero(dividend, instr);
    }
    // Check for (kMinInt / -1).
    if (hdiv->CheckFlag(HValue::kCanOverflow) && divisor == -1) {
      // Test dividend for kMinInt by subtracting one (cmp) and checking for
      // overflow.
      __ Cmp(dividend, 1);
      DeoptimizeIf(vs, instr);
    }
    // Deoptimize if remainder will not be 0.
    if (!hdiv->CheckFlag(HInstruction::kAllUsesTruncatingToInt32) &&
        divisor != 1 && divisor != -1) {
      int32_t mask = divisor < 0 ? -(divisor + 1) : (divisor - 1);
      __ Tst(dividend, mask);
      DeoptimizeIf(ne, instr);
    }
  
    if (divisor == -1) {  // Nice shortcut, not needed for correctness.
      __ Neg(result, dividend);
      return;
    }
    int32_t shift = WhichPowerOf2Abs(divisor);
    if (shift == 0) {
      __ Mov(result, dividend);
    } else if (shift == 1) {
      __ Add(result, dividend, Operand(dividend, LSR, 31));
    } else {
      __ Mov(result, Operand(dividend, ASR, 31));
      __ Add(result, dividend, Operand(result, LSR, 32 - shift));
    }
    if (shift > 0) __ Mov(result, Operand(result, ASR, shift));
    if (divisor < 0) __ Neg(result, result);
  }
  
  
  void LCodeGen::DoDivByConstI(LDivByConstI* instr) {
    Register dividend = ToRegister32(instr->dividend());
    int32_t divisor = instr->divisor();
    Register result = ToRegister32(instr->result());
    DCHECK(!AreAliased(dividend, result));
  
    if (divisor == 0) {
      Deoptimize(instr);
      return;
    }
  
    // Check for (0 / -x) that will produce negative zero.
    HDiv* hdiv = instr->hydrogen();
    if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
      DeoptimizeIfZero(dividend, instr);
    }
  
    __ TruncatingDiv(result, dividend, Abs(divisor));
    if (divisor < 0) __ Neg(result, result);
  
    if (!hdiv->CheckFlag(HInstruction::kAllUsesTruncatingToInt32)) {
      Register temp = ToRegister32(instr->temp());
      DCHECK(!AreAliased(dividend, result, temp));
      __ Sxtw(dividend.X(), dividend);
      __ Mov(temp, divisor);
      __ Smsubl(temp.X(), result, temp, dividend.X());
      DeoptimizeIfNotZero(temp, instr);
    }
  }
  
  
  // TODO(svenpanne) Refactor this to avoid code duplication with DoFlooringDivI.
  void LCodeGen::DoDivI(LDivI* instr) {
    HBinaryOperation* hdiv = instr->hydrogen();
    Register dividend = ToRegister32(instr->dividend());
    Register divisor = ToRegister32(instr->divisor());
    Register result = ToRegister32(instr->result());
  
    // Issue the division first, and then check for any deopt cases whilst the
    // result is computed.
    __ Sdiv(result, dividend, divisor);
  
    if (hdiv->CheckFlag(HValue::kAllUsesTruncatingToInt32)) {
      DCHECK_EQ(NULL, instr->temp());
      return;
    }
  
    // Check for x / 0.
    if (hdiv->CheckFlag(HValue::kCanBeDivByZero)) {
      DeoptimizeIfZero(divisor, instr);
    }
  
    // Check for (0 / -x) as that will produce negative zero.
    if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero)) {
      __ Cmp(divisor, 0);
  
      // If the divisor < 0 (mi), compare the dividend, and deopt if it is
      // zero, ie. zero dividend with negative divisor deopts.
      // If the divisor >= 0 (pl, the opposite of mi) set the flags to
      // condition ne, so we don't deopt, ie. positive divisor doesn't deopt.
      __ Ccmp(dividend, 0, NoFlag, mi);
      DeoptimizeIf(eq, instr);
    }
  
    // Check for (kMinInt / -1).
    if (hdiv->CheckFlag(HValue::kCanOverflow)) {
      // Test dividend for kMinInt by subtracting one (cmp) and checking for
      // overflow.
      __ Cmp(dividend, 1);
      // If overflow is set, ie. dividend = kMinInt, compare the divisor with
      // -1. If overflow is clear, set the flags for condition ne, as the
      // dividend isn't -1, and thus we shouldn't deopt.
      __ Ccmp(divisor, -1, NoFlag, vs);
      DeoptimizeIf(eq, instr);
    }
  
    // Compute remainder and deopt if it's not zero.
    Register remainder = ToRegister32(instr->temp());
    __ Msub(remainder, result, divisor, dividend);
    DeoptimizeIfNotZero(remainder, instr);
  }
  
  
  void LCodeGen::DoDoubleToIntOrSmi(LDoubleToIntOrSmi* instr) {
    DoubleRegister input = ToDoubleRegister(instr->value());
    Register result = ToRegister32(instr->result());
  
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      DeoptimizeIfMinusZero(input, instr);
    }
  
    __ TryRepresentDoubleAsInt32(result, input, double_scratch());
    DeoptimizeIf(ne, instr);
  
    if (instr->tag_result()) {
      __ SmiTag(result.X());
    }
  }
  
  
  void LCodeGen::DoDrop(LDrop* instr) {
    __ Drop(instr->count());
  }
  
  
  void LCodeGen::DoDummy(LDummy* instr) {
    // Nothing to see here, move on!
  }
  
  
  void LCodeGen::DoDummyUse(LDummyUse* instr) {
    // Nothing to see here, move on!
  }
  
  
  void LCodeGen::DoFunctionLiteral(LFunctionLiteral* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    // FunctionLiteral instruction is marked as call, we can trash any register.
    DCHECK(instr->IsMarkedAsCall());
  
    // Use the fast case closure allocation code that allocates in new
    // space for nested functions that don't need literals cloning.
    bool pretenure = instr->hydrogen()->pretenure();
    if (!pretenure && instr->hydrogen()->has_no_literals()) {
      FastNewClosureStub stub(isolate(), instr->hydrogen()->strict_mode(),
                              instr->hydrogen()->kind());
      __ Mov(x2, Operand(instr->hydrogen()->shared_info()));
      CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
    } else {
      __ Mov(x2, Operand(instr->hydrogen()->shared_info()));
      __ Mov(x1, Operand(pretenure ? factory()->true_value()
                                   : factory()->false_value()));
      __ Push(cp, x2, x1);
      CallRuntime(Runtime::kNewClosure, 3, instr);
    }
  }
  
  
  void LCodeGen::DoForInCacheArray(LForInCacheArray* instr) {
    Register map = ToRegister(instr->map());
    Register result = ToRegister(instr->result());
    Label load_cache, done;
  
    __ EnumLengthUntagged(result, map);
    __ Cbnz(result, &load_cache);
  
    __ Mov(result, Operand(isolate()->factory()->empty_fixed_array()));
    __ B(&done);
  
    __ Bind(&load_cache);
    __ LoadInstanceDescriptors(map, result);
    __ Ldr(result, FieldMemOperand(result, DescriptorArray::kEnumCacheOffset));
    __ Ldr(result, FieldMemOperand(result, FixedArray::SizeFor(instr->idx())));
    DeoptimizeIfZero(result, instr);
  
    __ Bind(&done);
  }
  
  
  void LCodeGen::DoForInPrepareMap(LForInPrepareMap* instr) {
    Register object = ToRegister(instr->object());
    Register null_value = x5;
  
    DCHECK(instr->IsMarkedAsCall());
    DCHECK(object.Is(x0));
  
    DeoptimizeIfRoot(object, Heap::kUndefinedValueRootIndex, instr);
  
    __ LoadRoot(null_value, Heap::kNullValueRootIndex);
    __ Cmp(object, null_value);
    DeoptimizeIf(eq, instr);
  
    DeoptimizeIfSmi(object, instr);
  
    STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
    __ CompareObjectType(object, x1, x1, LAST_JS_PROXY_TYPE);
    DeoptimizeIf(le, instr);
  
    Label use_cache, call_runtime;
    __ CheckEnumCache(object, null_value, x1, x2, x3, x4, &call_runtime);
  
    __ Ldr(object, FieldMemOperand(object, HeapObject::kMapOffset));
    __ B(&use_cache);
  
    // Get the set of properties to enumerate.
    __ Bind(&call_runtime);
    __ Push(object);
    CallRuntime(Runtime::kGetPropertyNamesFast, 1, instr);
  
    __ Ldr(x1, FieldMemOperand(object, HeapObject::kMapOffset));
    DeoptimizeIfNotRoot(x1, Heap::kMetaMapRootIndex, instr);
  
    __ Bind(&use_cache);
  }
  
  
  void LCodeGen::DoGetCachedArrayIndex(LGetCachedArrayIndex* instr) {
    Register input = ToRegister(instr->value());
    Register result = ToRegister(instr->result());
  
    __ AssertString(input);
  
    // Assert that we can use a W register load to get the hash.
    DCHECK((String::kHashShift + String::kArrayIndexValueBits) < kWRegSizeInBits);
    __ Ldr(result.W(), FieldMemOperand(input, String::kHashFieldOffset));
    __ IndexFromHash(result, result);
  }
  
  
  void LCodeGen::EmitGoto(int block) {
    // Do not emit jump if we are emitting a goto to the next block.
    if (!IsNextEmittedBlock(block)) {
      __ B(chunk_->GetAssemblyLabel(LookupDestination(block)));
    }
  }
  
  
  void LCodeGen::DoGoto(LGoto* instr) {
    EmitGoto(instr->block_id());
  }
  
  
  void LCodeGen::DoHasCachedArrayIndexAndBranch(
      LHasCachedArrayIndexAndBranch* instr) {
    Register input = ToRegister(instr->value());
    Register temp = ToRegister32(instr->temp());
  
    // Assert that the cache status bits fit in a W register.
    DCHECK(is_uint32(String::kContainsCachedArrayIndexMask));
    __ Ldr(temp, FieldMemOperand(input, String::kHashFieldOffset));
    __ Tst(temp, String::kContainsCachedArrayIndexMask);
    EmitBranch(instr, eq);
  }
  
  
  // HHasInstanceTypeAndBranch instruction is built with an interval of type
  // to test but is only used in very restricted ways. The only possible kinds
  // of intervals are:
  //  - [ FIRST_TYPE, instr->to() ]
  //  - [ instr->form(), LAST_TYPE ]
  //  - instr->from() == instr->to()
  //
  // These kinds of intervals can be check with only one compare instruction
  // providing the correct value and test condition are used.
  //
  // TestType() will return the value to use in the compare instruction and
  // BranchCondition() will return the condition to use depending on the kind
  // of interval actually specified in the instruction.
  static InstanceType TestType(HHasInstanceTypeAndBranch* instr) {
    InstanceType from = instr->from();
    InstanceType to = instr->to();
    if (from == FIRST_TYPE) return to;
    DCHECK((from == to) || (to == LAST_TYPE));
    return from;
  }
  
  
  // See comment above TestType function for what this function does.
  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 input = ToRegister(instr->value());
    Register scratch = ToRegister(instr->temp());
  
    if (!instr->hydrogen()->value()->type().IsHeapObject()) {
      __ JumpIfSmi(input, instr->FalseLabel(chunk_));
    }
    __ CompareObjectType(input, scratch, scratch, TestType(instr->hydrogen()));
    EmitBranch(instr, BranchCondition(instr->hydrogen()));
  }
  
  
  void LCodeGen::DoInnerAllocatedObject(LInnerAllocatedObject* instr) {
    Register result = ToRegister(instr->result());
    Register base = ToRegister(instr->base_object());
    if (instr->offset()->IsConstantOperand()) {
      __ Add(result, base, ToOperand32(instr->offset()));
    } else {
      __ Add(result, base, Operand(ToRegister32(instr->offset()), SXTW));
    }
  }
  
  
  void LCodeGen::DoInstanceOf(LInstanceOf* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    // Assert that the arguments are in the registers expected by InstanceofStub.
    DCHECK(ToRegister(instr->left()).Is(InstanceofStub::left()));
    DCHECK(ToRegister(instr->right()).Is(InstanceofStub::right()));
  
    InstanceofStub stub(isolate(), InstanceofStub::kArgsInRegisters);
    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
  
    // InstanceofStub returns a result in x0:
    //   0     => not an instance
    //   smi 1 => instance.
    __ Cmp(x0, 0);
    __ LoadTrueFalseRoots(x0, x1);
    __ Csel(x0, x0, x1, eq);
  }
  
  
  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_);
      }
      virtual LInstruction* instr() { return instr_; }
     private:
      LInstanceOfKnownGlobal* instr_;
    };
  
    DeferredInstanceOfKnownGlobal* deferred =
        new(zone()) DeferredInstanceOfKnownGlobal(this, instr);
  
    Label map_check, return_false, cache_miss, done;
    Register object = ToRegister(instr->value());
    Register result = ToRegister(instr->result());
    // x4 is expected in the associated deferred code and stub.
    Register map_check_site = x4;
    Register map = x5;
  
    // This instruction is marked as call. We can clobber any register.
    DCHECK(instr->IsMarkedAsCall());
  
    // We must take into account that object is in x11.
    DCHECK(object.Is(x11));
    Register scratch = x10;
  
    // A Smi is not instance of anything.
    __ JumpIfSmi(object, &return_false);
  
    // 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.
    __ Ldr(map, FieldMemOperand(object, HeapObject::kMapOffset));
    {
      // Below we use Factory::the_hole_value() on purpose instead of loading from
      // the root array to force relocation and later be able to patch with a
      // custom value.
      InstructionAccurateScope scope(masm(), 5);
      __ bind(&map_check);
      // Will be patched with the cached map.
      Handle<Cell> cell = factory()->NewCell(factory()->the_hole_value());
      __ ldr(scratch, Immediate(Handle<Object>(cell)));
      __ ldr(scratch, FieldMemOperand(scratch, PropertyCell::kValueOffset));
      __ cmp(map, scratch);
      __ b(&cache_miss, ne);
      // The address of this instruction is computed relative to the map check
      // above, so check the size of the code generated.
      DCHECK(masm()->InstructionsGeneratedSince(&map_check) == 4);
      // Will be patched with the cached result.
      __ ldr(result, Immediate(factory()->the_hole_value()));
    }
    __ B(&done);
  
    // The inlined call site cache did not match.
    // Check null and string before calling the deferred code.
    __ Bind(&cache_miss);
    // Compute the address of the map check. It must not be clobbered until the
    // InstanceOfStub has used it.
    __ Adr(map_check_site, &map_check);
    // Null is not instance of anything.
    __ JumpIfRoot(object, Heap::kNullValueRootIndex, &return_false);
  
    // String values are not instances of anything.
    // Return false if the object is a string. Otherwise, jump to the deferred
    // code.
    // Note that we can't jump directly to deferred code from
    // IsObjectJSStringType, because it uses tbz for the jump and the deferred
    // code can be out of range.
    __ IsObjectJSStringType(object, scratch, NULL, &return_false);
    __ B(deferred->entry());
  
    __ Bind(&return_false);
    __ LoadRoot(result, Heap::kFalseValueRootIndex);
  
    // Here result is either true or false.
    __ Bind(deferred->exit());
    __ Bind(&done);
  }
  
  
  void LCodeGen::DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr) {
    Register result = ToRegister(instr->result());
    DCHECK(result.Is(x0));  // InstanceofStub returns its result in x0.
    InstanceofStub::Flags flags = InstanceofStub::kNoFlags;
    flags = static_cast<InstanceofStub::Flags>(
        flags | InstanceofStub::kArgsInRegisters);
    flags = static_cast<InstanceofStub::Flags>(
        flags | InstanceofStub::kReturnTrueFalseObject);
    flags = static_cast<InstanceofStub::Flags>(
        flags | InstanceofStub::kCallSiteInlineCheck);
  
    PushSafepointRegistersScope scope(this);
    LoadContextFromDeferred(instr->context());
  
    // Prepare InstanceofStub arguments.
    DCHECK(ToRegister(instr->value()).Is(InstanceofStub::left()));
    __ LoadObject(InstanceofStub::right(), instr->function());
  
    InstanceofStub stub(isolate(), flags);
    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.
    __ StoreToSafepointRegisterSlot(result, result);
  }
  
  
  void LCodeGen::DoInstructionGap(LInstructionGap* instr) {
    DoGap(instr);
  }
  
  
  void LCodeGen::DoInteger32ToDouble(LInteger32ToDouble* instr) {
    Register value = ToRegister32(instr->value());
    DoubleRegister result = ToDoubleRegister(instr->result());
    __ Scvtf(result, value);
  }
  
  
  void LCodeGen::DoInvokeFunction(LInvokeFunction* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    // The function is required to be in x1.
    DCHECK(ToRegister(instr->function()).is(x1));
    DCHECK(instr->HasPointerMap());
  
    Handle<JSFunction> known_function = instr->hydrogen()->known_function();
    if (known_function.is_null()) {
      LPointerMap* pointers = instr->pointer_map();
      SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
      ParameterCount count(instr->arity());
      __ InvokeFunction(x1, count, CALL_FUNCTION, generator);
    } else {
      CallKnownFunction(known_function,
                        instr->hydrogen()->formal_parameter_count(),
                        instr->arity(),
                        instr,
                        x1);
    }
    after_push_argument_ = false;
  }
  
  
  void LCodeGen::DoIsConstructCallAndBranch(LIsConstructCallAndBranch* instr) {
    Register temp1 = ToRegister(instr->temp1());
    Register temp2 = ToRegister(instr->temp2());
  
    // Get the frame pointer for the calling frame.
    __ Ldr(temp1, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
  
    // Skip the arguments adaptor frame if it exists.
    Label check_frame_marker;
    __ Ldr(temp2, MemOperand(temp1, StandardFrameConstants::kContextOffset));
    __ Cmp(temp2, Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
    __ B(ne, &check_frame_marker);
    __ Ldr(temp1, MemOperand(temp1, StandardFrameConstants::kCallerFPOffset));
  
    // Check the marker in the calling frame.
    __ Bind(&check_frame_marker);
    __ Ldr(temp1, MemOperand(temp1, StandardFrameConstants::kMarkerOffset));
  
    EmitCompareAndBranch(
        instr, eq, temp1, Operand(Smi::FromInt(StackFrame::CONSTRUCT)));
  }
  
  
  void LCodeGen::DoIsObjectAndBranch(LIsObjectAndBranch* instr) {
    Label* is_object = instr->TrueLabel(chunk_);
    Label* is_not_object = instr->FalseLabel(chunk_);
    Register value = ToRegister(instr->value());
    Register map = ToRegister(instr->temp1());
    Register scratch = ToRegister(instr->temp2());
  
    __ JumpIfSmi(value, is_not_object);
    __ JumpIfRoot(value, Heap::kNullValueRootIndex, is_object);
  
    __ Ldr(map, FieldMemOperand(value, HeapObject::kMapOffset));
  
    // Check for undetectable objects.
    __ Ldrb(scratch, FieldMemOperand(map, Map::kBitFieldOffset));
    __ TestAndBranchIfAnySet(scratch, 1 << Map::kIsUndetectable, is_not_object);
  
    // Check that instance type is in object type range.
    __ IsInstanceJSObjectType(map, scratch, NULL);
    // Flags have been updated by IsInstanceJSObjectType. We can now test the
    // flags for "le" condition to check if the object's type is a valid
    // JS object type.
    EmitBranch(instr, le);
  }
  
  
  Condition LCodeGen::EmitIsString(Register input,
                                   Register temp1,
                                   Label* is_not_string,
                                   SmiCheck check_needed = INLINE_SMI_CHECK) {
    if (check_needed == INLINE_SMI_CHECK) {
      __ JumpIfSmi(input, is_not_string);
    }
    __ CompareObjectType(input, temp1, temp1, FIRST_NONSTRING_TYPE);
  
    return lt;
  }
  
  
  void LCodeGen::DoIsStringAndBranch(LIsStringAndBranch* instr) {
    Register val = ToRegister(instr->value());
    Register scratch = ToRegister(instr->temp());
  
    SmiCheck check_needed =
        instr->hydrogen()->value()->type().IsHeapObject()
            ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
    Condition true_cond =
        EmitIsString(val, scratch, instr->FalseLabel(chunk_), check_needed);
  
    EmitBranch(instr, true_cond);
  }
  
  
  void LCodeGen::DoIsSmiAndBranch(LIsSmiAndBranch* instr) {
    Register value = ToRegister(instr->value());
    STATIC_ASSERT(kSmiTag == 0);
    EmitTestAndBranch(instr, eq, value, kSmiTagMask);
  }
  
  
  void LCodeGen::DoIsUndetectableAndBranch(LIsUndetectableAndBranch* instr) {
    Register input = ToRegister(instr->value());
    Register temp = ToRegister(instr->temp());
  
    if (!instr->hydrogen()->value()->type().IsHeapObject()) {
      __ JumpIfSmi(input, instr->FalseLabel(chunk_));
    }
    __ Ldr(temp, FieldMemOperand(input, HeapObject::kMapOffset));
    __ Ldrb(temp, FieldMemOperand(temp, Map::kBitFieldOffset));
  
    EmitTestAndBranch(instr, ne, temp, 1 << Map::kIsUndetectable);
  }
  
  
  static const char* LabelType(LLabel* label) {
    if (label->is_loop_header()) return " (loop header)";
    if (label->is_osr_entry()) return " (OSR entry)";
    return "";
  }
  
  
  void LCodeGen::DoLabel(LLabel* label) {
    Comment(";;; <@%d,#%d> -------------------- B%d%s --------------------",
            current_instruction_,
            label->hydrogen_value()->id(),
            label->block_id(),
            LabelType(label));
  
    __ Bind(label->label());
    current_block_ = label->block_id();
    DoGap(label);
  }
  
  
  void LCodeGen::DoLoadContextSlot(LLoadContextSlot* instr) {
    Register context = ToRegister(instr->context());
    Register result = ToRegister(instr->result());
    __ Ldr(result, ContextMemOperand(context, instr->slot_index()));
    if (instr->hydrogen()->RequiresHoleCheck()) {
      if (instr->hydrogen()->DeoptimizesOnHole()) {
        DeoptimizeIfRoot(result, Heap::kTheHoleValueRootIndex, instr);
      } else {
        Label not_the_hole;
        __ JumpIfNotRoot(result, Heap::kTheHoleValueRootIndex, &not_the_hole);
        __ LoadRoot(result, Heap::kUndefinedValueRootIndex);
        __ Bind(&not_the_hole);
      }
    }
  }
  
  
  void LCodeGen::DoLoadFunctionPrototype(LLoadFunctionPrototype* instr) {
    Register function = ToRegister(instr->function());
    Register result = ToRegister(instr->result());
    Register temp = ToRegister(instr->temp());
  
    // Get the prototype or initial map from the function.
    __ Ldr(result, FieldMemOperand(function,
                                   JSFunction::kPrototypeOrInitialMapOffset));
  
    // Check that the function has a prototype or an initial map.
    DeoptimizeIfRoot(result, Heap::kTheHoleValueRootIndex, instr);
  
    // If the function does not have an initial map, we're done.
    Label done;
    __ CompareObjectType(result, temp, temp, MAP_TYPE);
    __ B(ne, &done);
  
    // Get the prototype from the initial map.
    __ Ldr(result, FieldMemOperand(result, Map::kPrototypeOffset));
  
    // All done.
    __ Bind(&done);
  }
  
  
  void LCodeGen::DoLoadGlobalCell(LLoadGlobalCell* instr) {
    Register result = ToRegister(instr->result());
    __ Mov(result, Operand(Handle<Object>(instr->hydrogen()->cell().handle())));
    __ Ldr(result, FieldMemOperand(result, Cell::kValueOffset));
    if (instr->hydrogen()->RequiresHoleCheck()) {
      DeoptimizeIfRoot(result, Heap::kTheHoleValueRootIndex, instr);
    }
  }
  
  
  template <class T>
  void LCodeGen::EmitVectorLoadICRegisters(T* instr) {
    DCHECK(FLAG_vector_ics);
    Register vector = ToRegister(instr->temp_vector());
    DCHECK(vector.is(VectorLoadICDescriptor::VectorRegister()));
    __ Mov(vector, instr->hydrogen()->feedback_vector());
    // No need to allocate this register.
    DCHECK(VectorLoadICDescriptor::SlotRegister().is(x0));
    __ Mov(VectorLoadICDescriptor::SlotRegister(),
           Smi::FromInt(instr->hydrogen()->slot()));
  }
  
  
  void LCodeGen::DoLoadGlobalGeneric(LLoadGlobalGeneric* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->global_object())
               .is(LoadDescriptor::ReceiverRegister()));
    DCHECK(ToRegister(instr->result()).Is(x0));
    __ Mov(LoadDescriptor::NameRegister(), Operand(instr->name()));
    if (FLAG_vector_ics) {
      EmitVectorLoadICRegisters<LLoadGlobalGeneric>(instr);
    }
    ContextualMode mode = instr->for_typeof() ? NOT_CONTEXTUAL : CONTEXTUAL;
    Handle<Code> ic = CodeFactory::LoadIC(isolate(), mode).code();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
  }
  
  
  MemOperand LCodeGen::PrepareKeyedExternalArrayOperand(
      Register key,
      Register base,
      Register scratch,
      bool key_is_smi,
      bool key_is_constant,
      int constant_key,
      ElementsKind elements_kind,
      int base_offset) {
    int element_size_shift = ElementsKindToShiftSize(elements_kind);
  
    if (key_is_constant) {
      int key_offset = constant_key << element_size_shift;
      return MemOperand(base, key_offset + base_offset);
    }
  
    if (key_is_smi) {
      __ Add(scratch, base, Operand::UntagSmiAndScale(key, element_size_shift));
      return MemOperand(scratch, base_offset);
    }
  
    if (base_offset == 0) {
      return MemOperand(base, key, SXTW, element_size_shift);
    }
  
    DCHECK(!AreAliased(scratch, key));
    __ Add(scratch, base, base_offset);
    return MemOperand(scratch, key, SXTW, element_size_shift);
  }
  
  
  void LCodeGen::DoLoadKeyedExternal(LLoadKeyedExternal* instr) {
    Register ext_ptr = ToRegister(instr->elements());
    Register scratch;
    ElementsKind elements_kind = instr->elements_kind();
  
    bool key_is_smi = instr->hydrogen()->key()->representation().IsSmi();
    bool key_is_constant = instr->key()->IsConstantOperand();
    Register key = no_reg;
    int constant_key = 0;
    if (key_is_constant) {
      DCHECK(instr->temp() == NULL);
      constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
      if (constant_key & 0xf0000000) {
        Abort(kArrayIndexConstantValueTooBig);
      }
    } else {
      scratch = ToRegister(instr->temp());
      key = ToRegister(instr->key());
    }
  
    MemOperand mem_op =
        PrepareKeyedExternalArrayOperand(key, ext_ptr, scratch, key_is_smi,
                                         key_is_constant, constant_key,
                                         elements_kind,
                                         instr->base_offset());
  
    if ((elements_kind == EXTERNAL_FLOAT32_ELEMENTS) ||
        (elements_kind == FLOAT32_ELEMENTS)) {
      DoubleRegister result = ToDoubleRegister(instr->result());
      __ Ldr(result.S(), mem_op);
      __ Fcvt(result, result.S());
    } else if ((elements_kind == EXTERNAL_FLOAT64_ELEMENTS) ||
               (elements_kind == FLOAT64_ELEMENTS)) {
      DoubleRegister result = ToDoubleRegister(instr->result());
      __ Ldr(result, mem_op);
    } else {
      Register result = ToRegister(instr->result());
  
      switch (elements_kind) {
        case EXTERNAL_INT8_ELEMENTS:
        case INT8_ELEMENTS:
          __ Ldrsb(result, mem_op);
          break;
        case EXTERNAL_UINT8_CLAMPED_ELEMENTS:
        case EXTERNAL_UINT8_ELEMENTS:
        case UINT8_ELEMENTS:
        case UINT8_CLAMPED_ELEMENTS:
          __ Ldrb(result, mem_op);
          break;
        case EXTERNAL_INT16_ELEMENTS:
        case INT16_ELEMENTS:
          __ Ldrsh(result, mem_op);
          break;
        case EXTERNAL_UINT16_ELEMENTS:
        case UINT16_ELEMENTS:
          __ Ldrh(result, mem_op);
          break;
        case EXTERNAL_INT32_ELEMENTS:
        case INT32_ELEMENTS:
          __ Ldrsw(result, mem_op);
          break;
        case EXTERNAL_UINT32_ELEMENTS:
        case UINT32_ELEMENTS:
          __ Ldr(result.W(), mem_op);
          if (!instr->hydrogen()->CheckFlag(HInstruction::kUint32)) {
            // Deopt if value > 0x80000000.
            __ Tst(result, 0xFFFFFFFF80000000);
            DeoptimizeIf(ne, instr);
          }
          break;
        case FLOAT32_ELEMENTS:
        case FLOAT64_ELEMENTS:
        case INT32x4_ELEMENTS:
        case FLOAT32x4_ELEMENTS:
        case FLOAT64x2_ELEMENTS:
        case EXTERNAL_FLOAT32_ELEMENTS:
        case EXTERNAL_FLOAT64_ELEMENTS:
        case EXTERNAL_INT32x4_ELEMENTS:
        case EXTERNAL_FLOAT32x4_ELEMENTS:
        case EXTERNAL_FLOAT64x2_ELEMENTS:
        case FAST_HOLEY_DOUBLE_ELEMENTS:
        case FAST_HOLEY_ELEMENTS:
        case FAST_HOLEY_SMI_ELEMENTS:
        case FAST_DOUBLE_ELEMENTS:
        case FAST_ELEMENTS:
        case FAST_SMI_ELEMENTS:
        case DICTIONARY_ELEMENTS:
        case SLOPPY_ARGUMENTS_ELEMENTS:
          UNREACHABLE();
          break;
      }
    }
  }
  
  
  MemOperand LCodeGen::PrepareKeyedArrayOperand(Register base,
                                                Register elements,
                                                Register key,
                                                bool key_is_tagged,
                                                ElementsKind elements_kind,
                                                Representation representation,
                                                int base_offset) {
    STATIC_ASSERT(static_cast<unsigned>(kSmiValueSize) == kWRegSizeInBits);
    STATIC_ASSERT(kSmiTag == 0);
    int element_size_shift = ElementsKindToShiftSize(elements_kind);
  
    // Even though the HLoad/StoreKeyed instructions force the input
    // representation for the key to be an integer, the input gets replaced during
    // bounds check elimination with the index argument to the bounds check, which
    // can be tagged, so that case must be handled here, too.
    if (key_is_tagged) {
      __ Add(base, elements, Operand::UntagSmiAndScale(key, element_size_shift));
      if (representation.IsInteger32()) {
        DCHECK(elements_kind == FAST_SMI_ELEMENTS);
        // Read or write only the smi payload in the case of fast smi arrays.
        return UntagSmiMemOperand(base, base_offset);
      } else {
        return MemOperand(base, base_offset);
      }
    } else {
      // Sign extend key because it could be a 32-bit negative value or contain
      // garbage in the top 32-bits. The address computation happens in 64-bit.
      DCHECK((element_size_shift >= 0) && (element_size_shift <= 4));
      if (representation.IsInteger32()) {
        DCHECK(elements_kind == FAST_SMI_ELEMENTS);
        // Read or write only the smi payload in the case of fast smi arrays.
        __ Add(base, elements, Operand(key, SXTW, element_size_shift));
        return UntagSmiMemOperand(base, base_offset);
      } else {
        __ Add(base, elements, base_offset);
        return MemOperand(base, key, SXTW, element_size_shift);
      }
    }
  }
  
  
  void LCodeGen::DoLoadKeyedFixedDouble(LLoadKeyedFixedDouble* instr) {
    Register elements = ToRegister(instr->elements());
    DoubleRegister result = ToDoubleRegister(instr->result());
    MemOperand mem_op;
  
    if (instr->key()->IsConstantOperand()) {
      DCHECK(instr->hydrogen()->RequiresHoleCheck() ||
             (instr->temp() == NULL));
  
      int constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
      if (constant_key & 0xf0000000) {
        Abort(kArrayIndexConstantValueTooBig);
      }
      int offset = instr->base_offset() + constant_key * kDoubleSize;
      mem_op = MemOperand(elements, offset);
    } else {
      Register load_base = ToRegister(instr->temp());
      Register key = ToRegister(instr->key());
      bool key_is_tagged = instr->hydrogen()->key()->representation().IsSmi();
      mem_op = PrepareKeyedArrayOperand(load_base, elements, key, key_is_tagged,
                                        instr->hydrogen()->elements_kind(),
                                        instr->hydrogen()->representation(),
                                        instr->base_offset());
    }
  
    __ Ldr(result, mem_op);
  
    if (instr->hydrogen()->RequiresHoleCheck()) {
      Register scratch = ToRegister(instr->temp());
      // Detect the hole NaN by adding one to the integer representation of the
      // result, and checking for overflow.
      STATIC_ASSERT(kHoleNanInt64 == 0x7fffffffffffffff);
      __ Ldr(scratch, mem_op);
      __ Cmn(scratch, 1);
      DeoptimizeIf(vs, instr);
    }
  }
  
  
  void LCodeGen::DoLoadKeyedFixed(LLoadKeyedFixed* instr) {
    Register elements = ToRegister(instr->elements());
    Register result = ToRegister(instr->result());
    MemOperand mem_op;
  
    Representation representation = instr->hydrogen()->representation();
    if (instr->key()->IsConstantOperand()) {
      DCHECK(instr->temp() == NULL);
      LConstantOperand* const_operand = LConstantOperand::cast(instr->key());
      int offset = instr->base_offset() +
          ToInteger32(const_operand) * kPointerSize;
      if (representation.IsInteger32()) {
        DCHECK(instr->hydrogen()->elements_kind() == FAST_SMI_ELEMENTS);
        STATIC_ASSERT(static_cast<unsigned>(kSmiValueSize) == kWRegSizeInBits);
        STATIC_ASSERT(kSmiTag == 0);
        mem_op = UntagSmiMemOperand(elements, offset);
      } else {
        mem_op = MemOperand(elements, offset);
      }
    } else {
      Register load_base = ToRegister(instr->temp());
      Register key = ToRegister(instr->key());
      bool key_is_tagged = instr->hydrogen()->key()->representation().IsSmi();
  
      mem_op = PrepareKeyedArrayOperand(load_base, elements, key, key_is_tagged,
                                        instr->hydrogen()->elements_kind(),
                                        representation, instr->base_offset());
    }
  
    __ Load(result, mem_op, representation);
  
    if (instr->hydrogen()->RequiresHoleCheck()) {
      if (IsFastSmiElementsKind(instr->hydrogen()->elements_kind())) {
        DeoptimizeIfNotSmi(result, instr);
      } else {
        DeoptimizeIfRoot(result, Heap::kTheHoleValueRootIndex, instr);
      }
    }
  }
  
  
  void LCodeGen::DoLoadKeyedGeneric(LLoadKeyedGeneric* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->object()).is(LoadDescriptor::ReceiverRegister()));
    DCHECK(ToRegister(instr->key()).is(LoadDescriptor::NameRegister()));
    if (FLAG_vector_ics) {
      EmitVectorLoadICRegisters<LLoadKeyedGeneric>(instr);
    }
  
    Handle<Code> ic = CodeFactory::KeyedLoadIC(isolate()).code();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
  
    DCHECK(ToRegister(instr->result()).Is(x0));
  }
  
  
  void LCodeGen::DoLoadNamedField(LLoadNamedField* instr) {
    HObjectAccess access = instr->hydrogen()->access();
    int offset = access.offset();
    Register object = ToRegister(instr->object());
  
    if (access.IsExternalMemory()) {
      Register result = ToRegister(instr->result());
      __ Load(result, MemOperand(object, offset), access.representation());
      return;
    }
  
    if (instr->hydrogen()->representation().IsDouble()) {
      FPRegister result = ToDoubleRegister(instr->result());
      __ Ldr(result, FieldMemOperand(object, offset));
      return;
    }
  
    Register result = ToRegister(instr->result());
    Register source;
    if (access.IsInobject()) {
      source = object;
    } else {
      // Load the properties array, using result as a scratch register.
      __ Ldr(result, FieldMemOperand(object, JSObject::kPropertiesOffset));
      source = result;
    }
  
    if (access.representation().IsSmi() &&
        instr->hydrogen()->representation().IsInteger32()) {
      // Read int value directly from upper half of the smi.
      STATIC_ASSERT(static_cast<unsigned>(kSmiValueSize) == kWRegSizeInBits);
      STATIC_ASSERT(kSmiTag == 0);
      __ Load(result, UntagSmiFieldMemOperand(source, offset),
              Representation::Integer32());
    } else {
      __ Load(result, FieldMemOperand(source, offset), access.representation());
    }
  }
  
  
  void LCodeGen::DoLoadNamedGeneric(LLoadNamedGeneric* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    // LoadIC expects name and receiver in registers.
    DCHECK(ToRegister(instr->object()).is(LoadDescriptor::ReceiverRegister()));
    __ Mov(LoadDescriptor::NameRegister(), Operand(instr->name()));
    if (FLAG_vector_ics) {
      EmitVectorLoadICRegisters<LLoadNamedGeneric>(instr);
    }
  
    Handle<Code> ic = CodeFactory::LoadIC(isolate(), NOT_CONTEXTUAL).code();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
  
    DCHECK(ToRegister(instr->result()).is(x0));
  }
  
  
  void LCodeGen::DoLoadRoot(LLoadRoot* instr) {
    Register result = ToRegister(instr->result());
    __ LoadRoot(result, instr->index());
  }
  
  
  void LCodeGen::DoMapEnumLength(LMapEnumLength* instr) {
    Register result = ToRegister(instr->result());
    Register map = ToRegister(instr->value());
    __ EnumLengthSmi(result, map);
  }
  
  
  void LCodeGen::DoMathAbs(LMathAbs* instr) {
    Representation r = instr->hydrogen()->value()->representation();
    if (r.IsDouble()) {
      DoubleRegister input = ToDoubleRegister(instr->value());
      DoubleRegister result = ToDoubleRegister(instr->result());
      __ Fabs(result, input);
    } else if (r.IsSmi() || r.IsInteger32()) {
      Register input = r.IsSmi() ? ToRegister(instr->value())
                                 : ToRegister32(instr->value());
      Register result = r.IsSmi() ? ToRegister(instr->result())
                                  : ToRegister32(instr->result());
      __ Abs(result, input);
      DeoptimizeIf(vs, instr);
    }
  }
  
  
  void LCodeGen::DoDeferredMathAbsTagged(LMathAbsTagged* instr,
                                         Label* exit,
                                         Label* allocation_entry) {
    // Handle the tricky cases of MathAbsTagged:
    //  - HeapNumber inputs.
    //    - Negative inputs produce a positive result, so a new HeapNumber is
    //      allocated to hold it.
    //    - Positive inputs are returned as-is, since there is no need to allocate
    //      a new HeapNumber for the result.
    //  - The (smi) input -0x80000000, produces +0x80000000, which does not fit
    //    a smi. In this case, the inline code sets the result and jumps directly
    //    to the allocation_entry label.
    DCHECK(instr->context() != NULL);
    DCHECK(ToRegister(instr->context()).is(cp));
    Register input = ToRegister(instr->value());
    Register temp1 = ToRegister(instr->temp1());
    Register temp2 = ToRegister(instr->temp2());
    Register result_bits = ToRegister(instr->temp3());
    Register result = ToRegister(instr->result());
  
    Label runtime_allocation;
  
    // Deoptimize if the input is not a HeapNumber.
    DeoptimizeIfNotHeapNumber(input, instr);
  
    // If the argument is positive, we can return it as-is, without any need to
    // allocate a new HeapNumber for the result. We have to do this in integer
    // registers (rather than with fabs) because we need to be able to distinguish
    // the two zeroes.
    __ Ldr(result_bits, FieldMemOperand(input, HeapNumber::kValueOffset));
    __ Mov(result, input);
    __ Tbz(result_bits, kXSignBit, exit);
  
    // Calculate abs(input) by clearing the sign bit.
    __ Bic(result_bits, result_bits, kXSignMask);
  
    // Allocate a new HeapNumber to hold the result.
    //  result_bits   The bit representation of the (double) result.
    __ Bind(allocation_entry);
    __ AllocateHeapNumber(result, &runtime_allocation, temp1, temp2);
    // The inline (non-deferred) code will store result_bits into result.
    __ B(exit);
  
    __ Bind(&runtime_allocation);
    if (FLAG_debug_code) {
      // Because result is in the pointer map, we need to make sure it has a valid
      // tagged value before we call the runtime. We speculatively set it to the
      // input (for abs(+x)) or to a smi (for abs(-SMI_MIN)), so it should already
      // be valid.
      Label result_ok;
      Register input = ToRegister(instr->value());
      __ JumpIfSmi(result, &result_ok);
      __ Cmp(input, result);
      __ Assert(eq, kUnexpectedValue);
      __ Bind(&result_ok);
    }
  
    { PushSafepointRegistersScope scope(this);
      CallRuntimeFromDeferred(Runtime::kAllocateHeapNumber, 0, instr,
                              instr->context());
      __ StoreToSafepointRegisterSlot(x0, result);
    }
    // The inline (non-deferred) code will store result_bits into result.
  }
  
  
  void LCodeGen::DoMathAbsTagged(LMathAbsTagged* instr) {
    // Class for deferred case.
    class DeferredMathAbsTagged: public LDeferredCode {
     public:
      DeferredMathAbsTagged(LCodeGen* codegen, LMathAbsTagged* instr)
          : LDeferredCode(codegen), instr_(instr) { }
      virtual void Generate() {
        codegen()->DoDeferredMathAbsTagged(instr_, exit(),
                                           allocation_entry());
      }
      virtual LInstruction* instr() { return instr_; }
      Label* allocation_entry() { return &allocation; }
     private:
      LMathAbsTagged* instr_;
      Label allocation;
    };
  
    // TODO(jbramley): The early-exit mechanism would skip the new frame handling
    // in GenerateDeferredCode. Tidy this up.
    DCHECK(!NeedsDeferredFrame());
  
    DeferredMathAbsTagged* deferred =
        new(zone()) DeferredMathAbsTagged(this, instr);
  
    DCHECK(instr->hydrogen()->value()->representation().IsTagged() ||
           instr->hydrogen()->value()->representation().IsSmi());
    Register input = ToRegister(instr->value());
    Register result_bits = ToRegister(instr->temp3());
    Register result = ToRegister(instr->result());
    Label done;
  
    // Handle smis inline.
    // We can treat smis as 64-bit integers, since the (low-order) tag bits will
    // never get set by the negation. This is therefore the same as the Integer32
    // case in DoMathAbs, except that it operates on 64-bit values.
    STATIC_ASSERT((kSmiValueSize == 32) && (kSmiShift == 32) && (kSmiTag == 0));
  
    __ JumpIfNotSmi(input, deferred->entry());
  
    __ Abs(result, input, NULL, &done);
  
    // The result is the magnitude (abs) of the smallest value a smi can
    // represent, encoded as a double.
    __ Mov(result_bits, double_to_rawbits(0x80000000));
    __ B(deferred->allocation_entry());
  
    __ Bind(deferred->exit());
    __ Str(result_bits, FieldMemOperand(result, HeapNumber::kValueOffset));
  
    __ Bind(&done);
  }
  
  
  void LCodeGen::DoMathExp(LMathExp* instr) {
    DoubleRegister input = ToDoubleRegister(instr->value());
    DoubleRegister result = ToDoubleRegister(instr->result());
    DoubleRegister double_temp1 = ToDoubleRegister(instr->double_temp1());
    DoubleRegister double_temp2 = double_scratch();
    Register temp1 = ToRegister(instr->temp1());
    Register temp2 = ToRegister(instr->temp2());
    Register temp3 = ToRegister(instr->temp3());
  
    MathExpGenerator::EmitMathExp(masm(), input, result,
                                  double_temp1, double_temp2,
                                  temp1, temp2, temp3);
  }
  
  
  void LCodeGen::DoMathFloorD(LMathFloorD* instr) {
    DoubleRegister input = ToDoubleRegister(instr->value());
    DoubleRegister result = ToDoubleRegister(instr->result());
  
    __ Frintm(result, input);
  }
  
  
  void LCodeGen::DoMathFloorI(LMathFloorI* instr) {
    DoubleRegister input = ToDoubleRegister(instr->value());
    Register result = ToRegister(instr->result());
  
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      DeoptimizeIfMinusZero(input, instr);
    }
  
    __ Fcvtms(result, input);
  
    // Check that the result fits into a 32-bit integer.
    //  - The result did not overflow.
    __ Cmp(result, Operand(result, SXTW));
    //  - The input was not NaN.
    __ Fccmp(input, input, NoFlag, eq);
    DeoptimizeIf(ne, instr);
  }
  
  
  void LCodeGen::DoFlooringDivByPowerOf2I(LFlooringDivByPowerOf2I* instr) {
    Register dividend = ToRegister32(instr->dividend());
    Register result = ToRegister32(instr->result());
    int32_t divisor = instr->divisor();
  
    // If the divisor is 1, return the dividend.
    if (divisor == 1) {
      __ Mov(result, dividend, kDiscardForSameWReg);
      return;
    }
  
    // If the divisor is positive, things are easy: There can be no deopts and we
    // can simply do an arithmetic right shift.
    int32_t shift = WhichPowerOf2Abs(divisor);
    if (divisor > 1) {
      __ Mov(result, Operand(dividend, ASR, shift));
      return;
    }
  
    // If the divisor is negative, we have to negate and handle edge cases.
    __ Negs(result, dividend);
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      DeoptimizeIf(eq, instr);
    }
  
    // Dividing by -1 is basically negation, unless we overflow.
    if (divisor == -1) {
      if (instr->hydrogen()->CheckFlag(HValue::kLeftCanBeMinInt)) {
        DeoptimizeIf(vs, instr);
      }
      return;
    }
  
    // If the negation could not overflow, simply shifting is OK.
    if (!instr->hydrogen()->CheckFlag(HValue::kLeftCanBeMinInt)) {
      __ Mov(result, Operand(dividend, ASR, shift));
      return;
    }
  
    __ Asr(result, result, shift);
    __ Csel(result, result, kMinInt / divisor, vc);
  }
  
  
  void LCodeGen::DoFlooringDivByConstI(LFlooringDivByConstI* instr) {
    Register dividend = ToRegister32(instr->dividend());
    int32_t divisor = instr->divisor();
    Register result = ToRegister32(instr->result());
    DCHECK(!AreAliased(dividend, result));
  
    if (divisor == 0) {
      Deoptimize(instr);
      return;
    }
  
    // Check for (0 / -x) that will produce negative zero.
    HMathFloorOfDiv* hdiv = instr->hydrogen();
    if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
      DeoptimizeIfZero(dividend, instr);
    }
  
    // Easy case: We need no dynamic check for the dividend and the flooring
    // division is the same as the truncating division.
    if ((divisor > 0 && !hdiv->CheckFlag(HValue::kLeftCanBeNegative)) ||
        (divisor < 0 && !hdiv->CheckFlag(HValue::kLeftCanBePositive))) {
      __ TruncatingDiv(result, dividend, Abs(divisor));
      if (divisor < 0) __ Neg(result, result);
      return;
    }
  
    // In the general case we may need to adjust before and after the truncating
    // division to get a flooring division.
    Register temp = ToRegister32(instr->temp());
    DCHECK(!AreAliased(temp, dividend, result));
    Label needs_adjustment, done;
    __ Cmp(dividend, 0);
    __ B(divisor > 0 ? lt : gt, &needs_adjustment);
    __ TruncatingDiv(result, dividend, Abs(divisor));
    if (divisor < 0) __ Neg(result, result);
    __ B(&done);
    __ Bind(&needs_adjustment);
    __ Add(temp, dividend, Operand(divisor > 0 ? 1 : -1));
    __ TruncatingDiv(result, temp, Abs(divisor));
    if (divisor < 0) __ Neg(result, result);
    __ Sub(result, result, Operand(1));
    __ Bind(&done);
  }
  
  
  // TODO(svenpanne) Refactor this to avoid code duplication with DoDivI.
  void LCodeGen::DoFlooringDivI(LFlooringDivI* instr) {
    Register dividend = ToRegister32(instr->dividend());
    Register divisor = ToRegister32(instr->divisor());
    Register remainder = ToRegister32(instr->temp());
    Register result = ToRegister32(instr->result());
  
    // This can't cause an exception on ARM, so we can speculatively
    // execute it already now.
    __ Sdiv(result, dividend, divisor);
  
    // Check for x / 0.
    DeoptimizeIfZero(divisor, instr);
  
    // Check for (kMinInt / -1).
    if (instr->hydrogen()->CheckFlag(HValue::kCanOverflow)) {
      // The V flag will be set iff dividend == kMinInt.
      __ Cmp(dividend, 1);
      __ Ccmp(divisor, -1, NoFlag, vs);
      DeoptimizeIf(eq, instr);
    }
  
    // Check for (0 / -x) that will produce negative zero.
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      __ Cmp(divisor, 0);
      __ Ccmp(dividend, 0, ZFlag, mi);
      // "divisor" can't be null because the code would have already been
      // deoptimized. The Z flag is set only if (divisor < 0) and (dividend == 0).
      // In this case we need to deoptimize to produce a -0.
      DeoptimizeIf(eq, instr);
    }
  
    Label done;
    // If both operands have the same sign then we are done.
    __ Eor(remainder, dividend, divisor);
    __ Tbz(remainder, kWSignBit, &done);
  
    // Check if the result needs to be corrected.
    __ Msub(remainder, result, divisor, dividend);
    __ Cbz(remainder, &done);
    __ Sub(result, result, 1);
  
    __ Bind(&done);
  }
  
  
  void LCodeGen::DoMathLog(LMathLog* instr) {
    DCHECK(instr->IsMarkedAsCall());
    DCHECK(ToDoubleRegister(instr->value()).is(d0));
    __ CallCFunction(ExternalReference::math_log_double_function(isolate()),
                     0, 1);
    DCHECK(ToDoubleRegister(instr->result()).Is(d0));
  }
  
  
  void LCodeGen::DoMathClz32(LMathClz32* instr) {
    Register input = ToRegister32(instr->value());
    Register result = ToRegister32(instr->result());
    __ Clz(result, input);
  }
  
  
  void LCodeGen::DoMathPowHalf(LMathPowHalf* instr) {
    DoubleRegister input = ToDoubleRegister(instr->value());
    DoubleRegister result = ToDoubleRegister(instr->result());
    Label done;
  
    // Math.pow(x, 0.5) differs from fsqrt(x) in the following cases:
    //  Math.pow(-Infinity, 0.5) == +Infinity
    //  Math.pow(-0.0, 0.5) == +0.0
  
    // Catch -infinity inputs first.
    // TODO(jbramley): A constant infinity register would be helpful here.
    __ Fmov(double_scratch(), kFP64NegativeInfinity);
    __ Fcmp(double_scratch(), input);
    __ Fabs(result, input);
    __ B(&done, eq);
  
    // Add +0.0 to convert -0.0 to +0.0.
    __ Fadd(double_scratch(), input, fp_zero);
    __ Fsqrt(result, double_scratch());
  
    __ Bind(&done);
  }
  
  
  void LCodeGen::DoPower(LPower* instr) {
    Representation exponent_type = instr->hydrogen()->right()->representation();
    // Having marked this as a call, we can use any registers.
    // Just make sure that the input/output registers are the expected ones.
    Register tagged_exponent = MathPowTaggedDescriptor::exponent();
    Register integer_exponent = MathPowIntegerDescriptor::exponent();
    DCHECK(!instr->right()->IsDoubleRegister() ||
           ToDoubleRegister(instr->right()).is(d1));
    DCHECK(exponent_type.IsInteger32() || !instr->right()->IsRegister() ||
           ToRegister(instr->right()).is(tagged_exponent));
    DCHECK(!exponent_type.IsInteger32() ||
           ToRegister(instr->right()).is(integer_exponent));
    DCHECK(ToDoubleRegister(instr->left()).is(d0));
    DCHECK(ToDoubleRegister(instr->result()).is(d0));
  
    if (exponent_type.IsSmi()) {
      MathPowStub stub(isolate(), MathPowStub::TAGGED);
      __ CallStub(&stub);
    } else if (exponent_type.IsTagged()) {
      Label no_deopt;
      __ JumpIfSmi(tagged_exponent, &no_deopt);
      DeoptimizeIfNotHeapNumber(tagged_exponent, instr);
      __ Bind(&no_deopt);
      MathPowStub stub(isolate(), MathPowStub::TAGGED);
      __ CallStub(&stub);
    } else if (exponent_type.IsInteger32()) {
      // Ensure integer exponent has no garbage in top 32-bits, as MathPowStub
      // supports large integer exponents.
      __ Sxtw(integer_exponent, integer_exponent);
      MathPowStub stub(isolate(), MathPowStub::INTEGER);
      __ CallStub(&stub);
    } else {
      DCHECK(exponent_type.IsDouble());
      MathPowStub stub(isolate(), MathPowStub::DOUBLE);
      __ CallStub(&stub);
    }
  }
  
  
  void LCodeGen::DoMathRoundD(LMathRoundD* instr) {
    DoubleRegister input = ToDoubleRegister(instr->value());
    DoubleRegister result = ToDoubleRegister(instr->result());
    DoubleRegister scratch_d = double_scratch();
  
    DCHECK(!AreAliased(input, result, scratch_d));
  
    Label done;
  
    __ Frinta(result, input);
    __ Fcmp(input, 0.0);
    __ Fccmp(result, input, ZFlag, lt);
    // The result is correct if the input was in [-0, +infinity], or was a
    // negative integral value.
    __ B(eq, &done);
  
    // Here the input is negative, non integral, with an exponent lower than 52.
    // We do not have to worry about the 0.49999999999999994 (0x3fdfffffffffffff)
    // case. So we can safely add 0.5.
    __ Fmov(scratch_d, 0.5);
    __ Fadd(result, input, scratch_d);
    __ Frintm(result, result);
    // The range [-0.5, -0.0[ yielded +0.0. Force the sign to negative.
    __ Fabs(result, result);
    __ Fneg(result, result);
  
    __ Bind(&done);
  }
  
  
  void LCodeGen::DoMathRoundI(LMathRoundI* instr) {
    DoubleRegister input = ToDoubleRegister(instr->value());
    DoubleRegister temp = ToDoubleRegister(instr->temp1());
    DoubleRegister dot_five = double_scratch();
    Register result = ToRegister(instr->result());
    Label done;
  
    // Math.round() rounds to the nearest integer, with ties going towards
    // +infinity. This does not match any IEEE-754 rounding mode.
    //  - Infinities and NaNs are propagated unchanged, but cause deopts because
    //    they can't be represented as integers.
    //  - The sign of the result is the same as the sign of the input. This means
    //    that -0.0 rounds to itself, and values -0.5 <= input < 0 also produce a
    //    result of -0.0.
  
    // Add 0.5 and round towards -infinity.
    __ Fmov(dot_five, 0.5);
    __ Fadd(temp, input, dot_five);
    __ Fcvtms(result, temp);
  
    // The result is correct if:
    //  result is not 0, as the input could be NaN or [-0.5, -0.0].
    //  result is not 1, as 0.499...94 will wrongly map to 1.
    //  result fits in 32 bits.
    __ Cmp(result, Operand(result.W(), SXTW));
    __ Ccmp(result, 1, ZFlag, eq);
    __ B(hi, &done);
  
    // At this point, we have to handle possible inputs of NaN or numbers in the
    // range [-0.5, 1.5[, or numbers larger than 32 bits.
  
    // Deoptimize if the result > 1, as it must be larger than 32 bits.
    __ Cmp(result, 1);
    DeoptimizeIf(hi, instr);
  
    // Deoptimize for negative inputs, which at this point are only numbers in
    // the range [-0.5, -0.0]
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      __ Fmov(result, input);
      DeoptimizeIfNegative(result, instr);
    }
  
    // Deoptimize if the input was NaN.
    __ Fcmp(input, dot_five);
    DeoptimizeIf(vs, instr);
  
    // Now, the only unhandled inputs are in the range [0.0, 1.5[ (or [-0.5, 1.5[
    // if we didn't generate a -0.0 bailout). If input >= 0.5 then return 1,
    // else 0; we avoid dealing with 0.499...94 directly.
    __ Cset(result, ge);
    __ Bind(&done);
  }
  
  
  void LCodeGen::DoMathFround(LMathFround* instr) {
    DoubleRegister input = ToDoubleRegister(instr->value());
    DoubleRegister result = ToDoubleRegister(instr->result());
    __ Fcvt(result.S(), input);
    __ Fcvt(result, result.S());
  }
  
  
  void LCodeGen::DoMathSqrt(LMathSqrt* instr) {
    DoubleRegister input = ToDoubleRegister(instr->value());
    DoubleRegister result = ToDoubleRegister(instr->result());
    __ Fsqrt(result, input);
  }
  
  
  void LCodeGen::DoMathMinMax(LMathMinMax* instr) {
    HMathMinMax::Operation op = instr->hydrogen()->operation();
    if (instr->hydrogen()->representation().IsInteger32()) {
      Register result = ToRegister32(instr->result());
      Register left = ToRegister32(instr->left());
      Operand right = ToOperand32(instr->right());
  
      __ Cmp(left, right);
      __ Csel(result, left, right, (op == HMathMinMax::kMathMax) ? ge : le);
    } else if (instr->hydrogen()->representation().IsSmi()) {
      Register result = ToRegister(instr->result());
      Register left = ToRegister(instr->left());
      Operand right = ToOperand(instr->right());
  
      __ Cmp(left, right);
      __ Csel(result, left, right, (op == HMathMinMax::kMathMax) ? ge : le);
    } else {
      DCHECK(instr->hydrogen()->representation().IsDouble());
      DoubleRegister result = ToDoubleRegister(instr->result());
      DoubleRegister left = ToDoubleRegister(instr->left());
      DoubleRegister right = ToDoubleRegister(instr->right());
  
      if (op == HMathMinMax::kMathMax) {
        __ Fmax(result, left, right);
      } else {
        DCHECK(op == HMathMinMax::kMathMin);
        __ Fmin(result, left, right);
      }
    }
  }
  
  
  void LCodeGen::DoModByPowerOf2I(LModByPowerOf2I* instr) {
    Register dividend = ToRegister32(instr->dividend());
    int32_t divisor = instr->divisor();
    DCHECK(dividend.is(ToRegister32(instr->result())));
  
    // Theoretically, a variation of the branch-free code for integer division by
    // a power of 2 (calculating the remainder via an additional multiplication
    // (which gets simplified to an 'and') and subtraction) should be faster, and
    // this is exactly what GCC and clang emit. Nevertheless, benchmarks seem to
    // indicate that positive dividends are heavily favored, so the branching
    // version performs better.
    HMod* hmod = instr->hydrogen();
    int32_t mask = divisor < 0 ? -(divisor + 1) : (divisor - 1);
    Label dividend_is_not_negative, done;
    if (hmod->CheckFlag(HValue::kLeftCanBeNegative)) {
      __ Tbz(dividend, kWSignBit, &dividend_is_not_negative);
      // Note that this is correct even for kMinInt operands.
      __ Neg(dividend, dividend);
      __ And(dividend, dividend, mask);
      __ Negs(dividend, dividend);
      if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
        DeoptimizeIf(eq, instr);
      }
      __ B(&done);
    }
  
    __ bind(&dividend_is_not_negative);
    __ And(dividend, dividend, mask);
    __ bind(&done);
  }
  
  
  void LCodeGen::DoModByConstI(LModByConstI* instr) {
    Register dividend = ToRegister32(instr->dividend());
    int32_t divisor = instr->divisor();
    Register result = ToRegister32(instr->result());
    Register temp = ToRegister32(instr->temp());
    DCHECK(!AreAliased(dividend, result, temp));
  
    if (divisor == 0) {
      Deoptimize(instr);
      return;
    }
  
    __ TruncatingDiv(result, dividend, Abs(divisor));
    __ Sxtw(dividend.X(), dividend);
    __ Mov(temp, Abs(divisor));
    __ Smsubl(result.X(), result, temp, dividend.X());
  
    // Check for negative zero.
    HMod* hmod = instr->hydrogen();
    if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
      Label remainder_not_zero;
      __ Cbnz(result, &remainder_not_zero);
      DeoptimizeIfNegative(dividend, instr);
      __ bind(&remainder_not_zero);
    }
  }
  
  
  void LCodeGen::DoModI(LModI* instr) {
    Register dividend = ToRegister32(instr->left());
    Register divisor = ToRegister32(instr->right());
    Register result = ToRegister32(instr->result());
  
    Label done;
    // modulo = dividend - quotient * divisor
    __ Sdiv(result, dividend, divisor);
    if (instr->hydrogen()->CheckFlag(HValue::kCanBeDivByZero)) {
      DeoptimizeIfZero(divisor, instr);
    }
    __ Msub(result, result, divisor, dividend);
    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
      __ Cbnz(result, &done);
      DeoptimizeIfNegative(dividend, instr);
    }
    __ Bind(&done);
  }
  
  
  void LCodeGen::DoMulConstIS(LMulConstIS* instr) {
    DCHECK(instr->hydrogen()->representation().IsSmiOrInteger32());
    bool is_smi = instr->hydrogen()->representation().IsSmi();
    Register result =
        is_smi ? ToRegister(instr->result()) : ToRegister32(instr->result());
    Register left =
        is_smi ? ToRegister(instr->left()) : ToRegister32(instr->left()) ;
    int32_t right = ToInteger32(instr->right());
    DCHECK((right > -kMaxInt) || (right < kMaxInt));
  
    bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
    bool bailout_on_minus_zero =
      instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero);
  
    if (bailout_on_minus_zero) {
      if (right < 0) {
        // The result is -0 if right is negative and left is zero.
        DeoptimizeIfZero(left, instr);
      } else if (right == 0) {
        // The result is -0 if the right is zero and the left is negative.
        DeoptimizeIfNegative(left, instr);
      }
    }
  
    switch (right) {
      // Cases which can detect overflow.
      case -1:
        if (can_overflow) {
          // Only 0x80000000 can overflow here.
          __ Negs(result, left);
          DeoptimizeIf(vs, instr);
        } else {
          __ Neg(result, left);
        }
        break;
      case 0:
        // This case can never overflow.
        __ Mov(result, 0);
        break;
      case 1:
        // This case can never overflow.
        __ Mov(result, left, kDiscardForSameWReg);
        break;
      case 2:
        if (can_overflow) {
          __ Adds(result, left, left);
          DeoptimizeIf(vs, instr);
        } else {
          __ Add(result, left, left);
        }
        break;
  
      default:
        // Multiplication by constant powers of two (and some related values)
        // can be done efficiently with shifted operands.
        int32_t right_abs = Abs(right);
  
        if (base::bits::IsPowerOfTwo32(right_abs)) {
          int right_log2 = WhichPowerOf2(right_abs);
  
          if (can_overflow) {
            Register scratch = result;
            DCHECK(!AreAliased(scratch, left));
            __ Cls(scratch, left);
            __ Cmp(scratch, right_log2);
            DeoptimizeIf(lt, instr);
          }
  
          if (right >= 0) {
            // result = left << log2(right)
            __ Lsl(result, left, right_log2);
          } else {
            // result = -left << log2(-right)
            if (can_overflow) {
              __ Negs(result, Operand(left, LSL, right_log2));
              DeoptimizeIf(vs, instr);
            } else {
              __ Neg(result, Operand(left, LSL, right_log2));
            }
          }
          return;
        }
  
  
        // For the following cases, we could perform a conservative overflow check
        // with CLS as above. However the few cycles saved are likely not worth
        // the risk of deoptimizing more often than required.
        DCHECK(!can_overflow);
  
        if (right >= 0) {
          if (base::bits::IsPowerOfTwo32(right - 1)) {
            // result = left + left << log2(right - 1)
            __ Add(result, left, Operand(left, LSL, WhichPowerOf2(right - 1)));
          } else if (base::bits::IsPowerOfTwo32(right + 1)) {
            // result = -left + left << log2(right + 1)
            __ Sub(result, left, Operand(left, LSL, WhichPowerOf2(right + 1)));
            __ Neg(result, result);
          } else {
            UNREACHABLE();
          }
        } else {
          if (base::bits::IsPowerOfTwo32(-right + 1)) {
            // result = left - left << log2(-right + 1)
            __ Sub(result, left, Operand(left, LSL, WhichPowerOf2(-right + 1)));
          } else if (base::bits::IsPowerOfTwo32(-right - 1)) {
            // result = -left - left << log2(-right - 1)
            __ Add(result, left, Operand(left, LSL, WhichPowerOf2(-right - 1)));
            __ Neg(result, result);
          } else {
            UNREACHABLE();
          }
        }
    }
  }
  
  
  void LCodeGen::DoMulI(LMulI* instr) {
    Register result = ToRegister32(instr->result());
    Register left = ToRegister32(instr->left());
    Register right = ToRegister32(instr->right());
  
    bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
    bool bailout_on_minus_zero =
      instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero);
  
    if (bailout_on_minus_zero && !left.Is(right)) {
      // If one operand is zero and the other is negative, the result is -0.
      //  - Set Z (eq) if either left or right, or both, are 0.
      __ Cmp(left, 0);
      __ Ccmp(right, 0, ZFlag, ne);
      //  - If so (eq), set N (mi) if left + right is negative.
      //  - Otherwise, clear N.
      __ Ccmn(left, right, NoFlag, eq);
      DeoptimizeIf(mi, instr);
    }
  
    if (can_overflow) {
      __ Smull(result.X(), left, right);
      __ Cmp(result.X(), Operand(result, SXTW));
      DeoptimizeIf(ne, instr);
    } else {
      __ Mul(result, left, right);
    }
  }
  
  
  void LCodeGen::DoMulS(LMulS* instr) {
    Register result = ToRegister(instr->result());
    Register left = ToRegister(instr->left());
    Register right = ToRegister(instr->right());
  
    bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
    bool bailout_on_minus_zero =
      instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero);
  
    if (bailout_on_minus_zero && !left.Is(right)) {
      // If one operand is zero and the other is negative, the result is -0.
      //  - Set Z (eq) if either left or right, or both, are 0.
      __ Cmp(left, 0);
      __ Ccmp(right, 0, ZFlag, ne);
      //  - If so (eq), set N (mi) if left + right is negative.
      //  - Otherwise, clear N.
      __ Ccmn(left, right, NoFlag, eq);
      DeoptimizeIf(mi, instr);
    }
  
    STATIC_ASSERT((kSmiShift == 32) && (kSmiTag == 0));
    if (can_overflow) {
      __ Smulh(result, left, right);
      __ Cmp(result, Operand(result.W(), SXTW));
      __ SmiTag(result);
      DeoptimizeIf(ne, instr);
    } else {
      if (AreAliased(result, left, right)) {
        // All three registers are the same: half untag the input and then
        // multiply, giving a tagged result.
        STATIC_ASSERT((kSmiShift % 2) == 0);
        __ Asr(result, left, kSmiShift / 2);
        __ Mul(result, result, result);
      } else if (result.Is(left) && !left.Is(right)) {
        // Registers result and left alias, right is distinct: untag left into
        // result, and then multiply by right, giving a tagged result.
        __ SmiUntag(result, left);
        __ Mul(result, result, right);
      } else {
        DCHECK(!left.Is(result));
        // Registers result and right alias, left is distinct, or all registers
        // are distinct: untag right into result, and then multiply by left,
        // giving a tagged result.
        __ SmiUntag(result, right);
        __ Mul(result, left, result);
      }
    }
  }
  
  
  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 result = ToRegister(instr->result());
    __ Mov(result, 0);
  
    PushSafepointRegistersScope scope(this);
    // NumberTagU and NumberTagD use the context from the frame, rather than
    // the environment's HContext or HInlinedContext value.
    // They only call Runtime::kAllocateHeapNumber.
    // The corresponding HChange instructions are added in a phase that does
    // not have easy access to the local context.
    __ Ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
    __ CallRuntimeSaveDoubles(Runtime::kAllocateHeapNumber);
    RecordSafepointWithRegisters(
        instr->pointer_map(), 0, Safepoint::kNoLazyDeopt);
    __ StoreToSafepointRegisterSlot(x0, result);
  }
  
  
  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 = ToDoubleRegister(instr->value());
    Register result = ToRegister(instr->result());
    Register temp1 = ToRegister(instr->temp1());
    Register temp2 = ToRegister(instr->temp2());
  
    DeferredNumberTagD* deferred = new(zone()) DeferredNumberTagD(this, instr);
    if (FLAG_inline_new) {
      __ AllocateHeapNumber(result, deferred->entry(), temp1, temp2);
    } else {
      __ B(deferred->entry());
    }
  
    __ Bind(deferred->exit());
    __ Str(input, FieldMemOperand(result, HeapNumber::kValueOffset));
  }
  
  
  void LCodeGen::DoDeferredNumberTagU(LInstruction* instr,
                                      LOperand* value,
                                      LOperand* temp1,
                                      LOperand* temp2) {
    Label slow, convert_and_store;
    Register src = ToRegister32(value);
    Register dst = ToRegister(instr->result());
    Register scratch1 = ToRegister(temp1);
  
    if (FLAG_inline_new) {
      Register scratch2 = ToRegister(temp2);
      __ AllocateHeapNumber(dst, &slow, scratch1, scratch2);
      __ B(&convert_and_store);
    }
  
    // 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.
    __ Mov(dst, 0);
    {
      // Preserve the value of all registers.
      PushSafepointRegistersScope scope(this);
  
      // NumberTagU and NumberTagD use the context from the frame, rather than
      // the environment's HContext or HInlinedContext value.
      // They only call Runtime::kAllocateHeapNumber.
      // The corresponding HChange instructions are added in a phase that does
      // not have easy access to the local context.
      __ Ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
      __ CallRuntimeSaveDoubles(Runtime::kAllocateHeapNumber);
      RecordSafepointWithRegisters(
        instr->pointer_map(), 0, Safepoint::kNoLazyDeopt);
      __ StoreToSafepointRegisterSlot(x0, dst);
    }
  
    // Convert number to floating point and store in the newly allocated heap
    // number.
    __ Bind(&convert_and_store);
    DoubleRegister dbl_scratch = double_scratch();
    __ Ucvtf(dbl_scratch, src);
    __ Str(dbl_scratch, FieldMemOperand(dst, HeapNumber::kValueOffset));
  }
  
  
  void LCodeGen::DoNumberTagU(LNumberTagU* instr) {
    class DeferredNumberTagU: public LDeferredCode {
     public:
      DeferredNumberTagU(LCodeGen* codegen, LNumberTagU* instr)
          : LDeferredCode(codegen), instr_(instr) { }
      virtual void Generate() {
        codegen()->DoDeferredNumberTagU(instr_,
                                        instr_->value(),
                                        instr_->temp1(),
                                        instr_->temp2());
      }
      virtual LInstruction* instr() { return instr_; }
     private:
      LNumberTagU* instr_;
    };
  
    Register value = ToRegister32(instr->value());
    Register result = ToRegister(instr->result());
  
    DeferredNumberTagU* deferred = new(zone()) DeferredNumberTagU(this, instr);
    __ Cmp(value, Smi::kMaxValue);
    __ B(hi, deferred->entry());
    __ SmiTag(result, value.X());
    __ Bind(deferred->exit());
  }
  
  
  void LCodeGen::DoNumberUntagD(LNumberUntagD* instr) {
    Register input = ToRegister(instr->value());
    Register scratch = ToRegister(instr->temp());
    DoubleRegister result = ToDoubleRegister(instr->result());
    bool can_convert_undefined_to_nan =
        instr->hydrogen()->can_convert_undefined_to_nan();
  
    Label done, load_smi;
  
    // Work out what untag mode we're working with.
    HValue* value = instr->hydrogen()->value();
    NumberUntagDMode mode = value->representation().IsSmi()
        ? NUMBER_CANDIDATE_IS_SMI : NUMBER_CANDIDATE_IS_ANY_TAGGED;
  
    if (mode == NUMBER_CANDIDATE_IS_ANY_TAGGED) {
      __ JumpIfSmi(input, &load_smi);
  
      Label convert_undefined;
  
      // Heap number map check.
      if (can_convert_undefined_to_nan) {
        __ JumpIfNotHeapNumber(input, &convert_undefined);
      } else {
        DeoptimizeIfNotHeapNumber(input, instr);
      }
  
      // Load heap number.
      __ Ldr(result, FieldMemOperand(input, HeapNumber::kValueOffset));
      if (instr->hydrogen()->deoptimize_on_minus_zero()) {
        DeoptimizeIfMinusZero(result, instr);
      }
      __ B(&done);
  
      if (can_convert_undefined_to_nan) {
        __ Bind(&convert_undefined);
        DeoptimizeIfNotRoot(input, Heap::kUndefinedValueRootIndex, instr);
  
        __ LoadRoot(scratch, Heap::kNanValueRootIndex);
        __ Ldr(result, FieldMemOperand(scratch, HeapNumber::kValueOffset));
        __ B(&done);
      }
  
    } else {
      DCHECK(mode == NUMBER_CANDIDATE_IS_SMI);
      // Fall through to load_smi.
    }
  
    // Smi to double register conversion.
    __ Bind(&load_smi);
    __ SmiUntagToDouble(result, input);
  
    __ Bind(&done);
  }
  
  
  void LCodeGen::DoOsrEntry(LOsrEntry* instr) {
    // This is a pseudo-instruction that ensures that the environment here is
    // properly registered for deoptimization and records the assembler's PC
    // offset.
    LEnvironment* environment = instr->environment();
  
    // If the environment were already registered, we would have no way of
    // backpatching it with the spill slot operands.
    DCHECK(!environment->HasBeenRegistered());
    RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
  
    GenerateOsrPrologue();
  }
  
  
  void LCodeGen::DoParameter(LParameter* instr) {
    // Nothing to do.
  }
  
  
  void LCodeGen::DoPreparePushArguments(LPreparePushArguments* instr) {
    __ PushPreamble(instr->argc(), kPointerSize);
  }
  
  
  void LCodeGen::DoPushArguments(LPushArguments* instr) {
    MacroAssembler::PushPopQueue args(masm());
  
    for (int i = 0; i < instr->ArgumentCount(); ++i) {
      LOperand* arg = instr->argument(i);
      if (arg->IsDoubleRegister() || arg->IsDoubleStackSlot()) {
        Abort(kDoPushArgumentNotImplementedForDoubleType);
        return;
      }
      args.Queue(ToRegister(arg));
    }
  
    // The preamble was done by LPreparePushArguments.
    args.PushQueued(MacroAssembler::PushPopQueue::SKIP_PREAMBLE);
  
    after_push_argument_ = true;
  }
  
  
  void LCodeGen::DoReturn(LReturn* instr) {
    if (FLAG_trace && info()->IsOptimizing()) {
      // Push the return value on the stack as the parameter.
      // Runtime::TraceExit returns its parameter in x0.  We're leaving the code
      // managed by the register allocator and tearing down the frame, it's
      // safe to write to the context register.
      __ Push(x0);
      __ Ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
      __ CallRuntime(Runtime::kTraceExit, 1);
    }
  
    if (info()->saves_caller_doubles()) {
      RestoreCallerDoubles();
    }
  
    int no_frame_start = -1;
    if (NeedsEagerFrame()) {
      Register stack_pointer = masm()->StackPointer();
      __ Mov(stack_pointer, fp);
      no_frame_start = masm_->pc_offset();
      __ Pop(fp, lr);
    }
  
    if (instr->has_constant_parameter_count()) {
      int parameter_count = ToInteger32(instr->constant_parameter_count());
      __ Drop(parameter_count + 1);
    } else {
      Register parameter_count = ToRegister(instr->parameter_count());
      __ DropBySMI(parameter_count);
    }
    __ Ret();
  
    if (no_frame_start != -1) {
      info_->AddNoFrameRange(no_frame_start, masm_->pc_offset());
    }
  }
  
  
  MemOperand LCodeGen::BuildSeqStringOperand(Register string,
                                             Register temp,
                                             LOperand* index,
                                             String::Encoding encoding) {
    if (index->IsConstantOperand()) {
      int offset = ToInteger32(LConstantOperand::cast(index));
      if (encoding == String::TWO_BYTE_ENCODING) {
        offset *= kUC16Size;
      }
      STATIC_ASSERT(kCharSize == 1);
      return FieldMemOperand(string, SeqString::kHeaderSize + offset);
    }
  
    __ Add(temp, string, SeqString::kHeaderSize - kHeapObjectTag);
    if (encoding == String::ONE_BYTE_ENCODING) {
      return MemOperand(temp, ToRegister32(index), SXTW);
    } else {
      STATIC_ASSERT(kUC16Size == 2);
      return MemOperand(temp, ToRegister32(index), SXTW, 1);
    }
  }
  
  
  void LCodeGen::DoSeqStringGetChar(LSeqStringGetChar* instr) {
    String::Encoding encoding = instr->hydrogen()->encoding();
    Register string = ToRegister(instr->string());
    Register result = ToRegister(instr->result());
    Register temp = ToRegister(instr->temp());
  
    if (FLAG_debug_code) {
      // Even though this lithium instruction comes with a temp register, we
      // can't use it here because we want to use "AtStart" constraints on the
      // inputs and the debug code here needs a scratch register.
      UseScratchRegisterScope temps(masm());
      Register dbg_temp = temps.AcquireX();
  
      __ Ldr(dbg_temp, FieldMemOperand(string, HeapObject::kMapOffset));
      __ Ldrb(dbg_temp, FieldMemOperand(dbg_temp, Map::kInstanceTypeOffset));
  
      __ And(dbg_temp, dbg_temp,
             Operand(kStringRepresentationMask | kStringEncodingMask));
      static const uint32_t one_byte_seq_type = kSeqStringTag | kOneByteStringTag;
      static const uint32_t two_byte_seq_type = kSeqStringTag | kTwoByteStringTag;
      __ Cmp(dbg_temp, Operand(encoding == String::ONE_BYTE_ENCODING
                               ? one_byte_seq_type : two_byte_seq_type));
      __ Check(eq, kUnexpectedStringType);
    }
  
    MemOperand operand =
        BuildSeqStringOperand(string, temp, instr->index(), encoding);
    if (encoding == String::ONE_BYTE_ENCODING) {
      __ Ldrb(result, operand);
    } else {
      __ Ldrh(result, operand);
    }
  }
  
  
  void LCodeGen::DoSeqStringSetChar(LSeqStringSetChar* instr) {
    String::Encoding encoding = instr->hydrogen()->encoding();
    Register string = ToRegister(instr->string());
    Register value = ToRegister(instr->value());
    Register temp = ToRegister(instr->temp());
  
    if (FLAG_debug_code) {
      DCHECK(ToRegister(instr->context()).is(cp));
      Register index = ToRegister(instr->index());
      static const uint32_t one_byte_seq_type = kSeqStringTag | kOneByteStringTag;
      static const uint32_t two_byte_seq_type = kSeqStringTag | kTwoByteStringTag;
      int encoding_mask =
          instr->hydrogen()->encoding() == String::ONE_BYTE_ENCODING
          ? one_byte_seq_type : two_byte_seq_type;
      __ EmitSeqStringSetCharCheck(string, index, kIndexIsInteger32, temp,
                                   encoding_mask);
    }
    MemOperand operand =
        BuildSeqStringOperand(string, temp, instr->index(), encoding);
    if (encoding == String::ONE_BYTE_ENCODING) {
      __ Strb(value, operand);
    } else {
      __ Strh(value, operand);
    }
  }
  
  
  void LCodeGen::DoSmiTag(LSmiTag* instr) {
    HChange* hchange = instr->hydrogen();
    Register input = ToRegister(instr->value());
    Register output = ToRegister(instr->result());
    if (hchange->CheckFlag(HValue::kCanOverflow) &&
        hchange->value()->CheckFlag(HValue::kUint32)) {
      DeoptimizeIfNegative(input.W(), instr);
    }
    __ SmiTag(output, input);
  }
  
  
  void LCodeGen::DoSmiUntag(LSmiUntag* instr) {
    Register input = ToRegister(instr->value());
    Register result = ToRegister(instr->result());
    Label done, untag;
  
    if (instr->needs_check()) {
      DeoptimizeIfNotSmi(input, instr);
    }
  
    __ Bind(&untag);
    __ SmiUntag(result, input);
    __ Bind(&done);
  }
  
  
  void LCodeGen::DoShiftI(LShiftI* instr) {
    LOperand* right_op = instr->right();
    Register left = ToRegister32(instr->left());
    Register result = ToRegister32(instr->result());
  
    if (right_op->IsRegister()) {
      Register right = ToRegister32(instr->right());
      switch (instr->op()) {
        case Token::ROR: __ Ror(result, left, right); break;
        case Token::SAR: __ Asr(result, left, right); break;
        case Token::SHL: __ Lsl(result, left, right); break;
        case Token::SHR:
          __ Lsr(result, left, right);
          if (instr->can_deopt()) {
            // If `left >>> right` >= 0x80000000, the result is not representable
            // in a signed 32-bit smi.
            DeoptimizeIfNegative(result, instr);
          }
          break;
        default: UNREACHABLE();
      }
    } else {
      DCHECK(right_op->IsConstantOperand());
      int shift_count = JSShiftAmountFromLConstant(right_op);
      if (shift_count == 0) {
        if ((instr->op() == Token::SHR) && instr->can_deopt()) {
          DeoptimizeIfNegative(left, instr);
        }
        __ Mov(result, left, kDiscardForSameWReg);
      } else {
        switch (instr->op()) {
          case Token::ROR: __ Ror(result, left, shift_count); break;
          case Token::SAR: __ Asr(result, left, shift_count); break;
          case Token::SHL: __ Lsl(result, left, shift_count); break;
          case Token::SHR: __ Lsr(result, left, shift_count); break;
          default: UNREACHABLE();
        }
      }
    }
  }
  
  
  void LCodeGen::DoShiftS(LShiftS* instr) {
    LOperand* right_op = instr->right();
    Register left = ToRegister(instr->left());
    Register result = ToRegister(instr->result());
  
    if (right_op->IsRegister()) {
      Register right = ToRegister(instr->right());
  
      // JavaScript shifts only look at the bottom 5 bits of the 'right' operand.
      // Since we're handling smis in X registers, we have to extract these bits
      // explicitly.
      __ Ubfx(result, right, kSmiShift, 5);
  
      switch (instr->op()) {
        case Token::ROR: {
          // This is the only case that needs a scratch register. To keep things
          // simple for the other cases, borrow a MacroAssembler scratch register.
          UseScratchRegisterScope temps(masm());
          Register temp = temps.AcquireW();
          __ SmiUntag(temp, left);
          __ Ror(result.W(), temp.W(), result.W());
          __ SmiTag(result);
          break;
        }
        case Token::SAR:
          __ Asr(result, left, result);
          __ Bic(result, result, kSmiShiftMask);
          break;
        case Token::SHL:
          __ Lsl(result, left, result);
          break;
        case Token::SHR:
          __ Lsr(result, left, result);
          __ Bic(result, result, kSmiShiftMask);
          if (instr->can_deopt()) {
            // If `left >>> right` >= 0x80000000, the result is not representable
            // in a signed 32-bit smi.
            DeoptimizeIfNegative(result, instr);
          }
          break;
        default: UNREACHABLE();
      }
    } else {
      DCHECK(right_op->IsConstantOperand());
      int shift_count = JSShiftAmountFromLConstant(right_op);
      if (shift_count == 0) {
        if ((instr->op() == Token::SHR) && instr->can_deopt()) {
          DeoptimizeIfNegative(left, instr);
        }
        __ Mov(result, left);
      } else {
        switch (instr->op()) {
          case Token::ROR:
            __ SmiUntag(result, left);
            __ Ror(result.W(), result.W(), shift_count);
            __ SmiTag(result);
            break;
          case Token::SAR:
            __ Asr(result, left, shift_count);
            __ Bic(result, result, kSmiShiftMask);
            break;
          case Token::SHL:
            __ Lsl(result, left, shift_count);
            break;
          case Token::SHR:
            __ Lsr(result, left, shift_count);
            __ Bic(result, result, kSmiShiftMask);
            break;
          default: UNREACHABLE();
        }
      }
    }
  }
  
  
  void LCodeGen::DoDebugBreak(LDebugBreak* instr) {
    __ Debug("LDebugBreak", 0, BREAK);
  }
  
  
  void LCodeGen::DoDeclareGlobals(LDeclareGlobals* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    Register scratch1 = x5;
    Register scratch2 = x6;
    DCHECK(instr->IsMarkedAsCall());
  
    ASM_UNIMPLEMENTED_BREAK("DoDeclareGlobals");
    // TODO(all): if Mov could handle object in new space then it could be used
    // here.
    __ LoadHeapObject(scratch1, instr->hydrogen()->pairs());
    __ Mov(scratch2, Smi::FromInt(instr->hydrogen()->flags()));
    __ Push(cp, scratch1, scratch2);  // The context is the first argument.
    CallRuntime(Runtime::kDeclareGlobals, 3, instr);
  }
  
  
  void LCodeGen::DoDeferredStackCheck(LStackCheck* instr) {
    PushSafepointRegistersScope scope(this);
    LoadContextFromDeferred(instr->context());
    __ CallRuntimeSaveDoubles(Runtime::kStackGuard);
    RecordSafepointWithLazyDeopt(
        instr, RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS);
    DCHECK(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_;
    };
  
    DCHECK(instr->HasEnvironment());
    LEnvironment* env = instr->environment();
    // There is no LLazyBailout instruction for stack-checks. We have to
    // prepare for lazy deoptimization explicitly here.
    if (instr->hydrogen()->is_function_entry()) {
      // Perform stack overflow check.
      Label done;
      __ CompareRoot(masm()->StackPointer(), Heap::kStackLimitRootIndex);
      __ B(hs, &done);
  
      PredictableCodeSizeScope predictable(masm_,
                                           Assembler::kCallSizeWithRelocation);
      DCHECK(instr->context()->IsRegister());
      DCHECK(ToRegister(instr->context()).is(cp));
      CallCode(isolate()->builtins()->StackCheck(),
               RelocInfo::CODE_TARGET,
               instr);
      __ Bind(&done);
    } else {
      DCHECK(instr->hydrogen()->is_backwards_branch());
      // Perform stack overflow check if this goto needs it before jumping.
      DeferredStackCheck* deferred_stack_check =
          new(zone()) DeferredStackCheck(this, instr);
      __ CompareRoot(masm()->StackPointer(), Heap::kStackLimitRootIndex);
      __ B(lo, deferred_stack_check->entry());
  
      EnsureSpaceForLazyDeopt(Deoptimizer::patch_size());
      __ Bind(instr->done_label());
      deferred_stack_check->SetExit(instr->done_label());
      RegisterEnvironmentForDeoptimization(env, Safepoint::kLazyDeopt);
      // Don't record a deoptimization index for the safepoint here.
      // This will be done explicitly when emitting call and the safepoint in
      // the deferred code.
    }
  }
  
  
  void LCodeGen::DoStoreCodeEntry(LStoreCodeEntry* instr) {
    Register function = ToRegister(instr->function());
    Register code_object = ToRegister(instr->code_object());
    Register temp = ToRegister(instr->temp());
    __ Add(temp, code_object, Code::kHeaderSize - kHeapObjectTag);
    __ Str(temp, FieldMemOperand(function, JSFunction::kCodeEntryOffset));
  }
  
  
  void LCodeGen::DoStoreContextSlot(LStoreContextSlot* instr) {
    Register context = ToRegister(instr->context());
    Register value = ToRegister(instr->value());
    Register scratch = ToRegister(instr->temp());
    MemOperand target = ContextMemOperand(context, instr->slot_index());
  
    Label skip_assignment;
  
    if (instr->hydrogen()->RequiresHoleCheck()) {
      __ Ldr(scratch, target);
      if (instr->hydrogen()->DeoptimizesOnHole()) {
        DeoptimizeIfRoot(scratch, Heap::kTheHoleValueRootIndex, instr);
      } else {
        __ JumpIfNotRoot(scratch, Heap::kTheHoleValueRootIndex, &skip_assignment);
      }
    }
  
    __ Str(value, target);
    if (instr->hydrogen()->NeedsWriteBarrier()) {
      SmiCheck check_needed =
          instr->hydrogen()->value()->type().IsHeapObject()
              ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
      __ RecordWriteContextSlot(context,
                                target.offset(),
                                value,
                                scratch,
                                GetLinkRegisterState(),
                                kSaveFPRegs,
                                EMIT_REMEMBERED_SET,
                                check_needed);
    }
    __ Bind(&skip_assignment);
  }
  
  
  void LCodeGen::DoStoreGlobalCell(LStoreGlobalCell* instr) {
    Register value = ToRegister(instr->value());
    Register cell = ToRegister(instr->temp1());
  
    // Load the cell.
    __ Mov(cell, Operand(instr->hydrogen()->cell().handle()));
  
    // If the cell we are storing to contains the hole it could have
    // been deleted from the property dictionary. In that case, we need
    // to update the property details in the property dictionary to mark
    // it as no longer deleted. We deoptimize in that case.
    if (instr->hydrogen()->RequiresHoleCheck()) {
      Register payload = ToRegister(instr->temp2());
      __ Ldr(payload, FieldMemOperand(cell, Cell::kValueOffset));
      DeoptimizeIfRoot(payload, Heap::kTheHoleValueRootIndex, instr);
    }
  
    // Store the value.
    __ Str(value, FieldMemOperand(cell, Cell::kValueOffset));
    // Cells are always rescanned, so no write barrier here.
  }
  
  
  void LCodeGen::DoStoreKeyedExternal(LStoreKeyedExternal* instr) {
    Register ext_ptr = ToRegister(instr->elements());
    Register key = no_reg;
    Register scratch;
    ElementsKind elements_kind = instr->elements_kind();
  
    bool key_is_smi = instr->hydrogen()->key()->representation().IsSmi();
    bool key_is_constant = instr->key()->IsConstantOperand();
    int constant_key = 0;
    if (key_is_constant) {
      DCHECK(instr->temp() == NULL);
      constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
      if (constant_key & 0xf0000000) {
        Abort(kArrayIndexConstantValueTooBig);
      }
    } else {
      key = ToRegister(instr->key());
      scratch = ToRegister(instr->temp());
    }
  
    MemOperand dst =
      PrepareKeyedExternalArrayOperand(key, ext_ptr, scratch, key_is_smi,
                                       key_is_constant, constant_key,
                                       elements_kind,
                                       instr->base_offset());
  
    if ((elements_kind == EXTERNAL_FLOAT32_ELEMENTS) ||
        (elements_kind == FLOAT32_ELEMENTS)) {
      DoubleRegister value = ToDoubleRegister(instr->value());
      DoubleRegister dbl_scratch = double_scratch();
      __ Fcvt(dbl_scratch.S(), value);
      __ Str(dbl_scratch.S(), dst);
    } else if ((elements_kind == EXTERNAL_FLOAT64_ELEMENTS) ||
               (elements_kind == FLOAT64_ELEMENTS)) {
      DoubleRegister value = ToDoubleRegister(instr->value());
      __ Str(value, dst);
    } else {
      Register value = ToRegister(instr->value());
  
      switch (elements_kind) {
        case EXTERNAL_UINT8_CLAMPED_ELEMENTS:
        case EXTERNAL_INT8_ELEMENTS:
        case EXTERNAL_UINT8_ELEMENTS:
        case UINT8_ELEMENTS:
        case UINT8_CLAMPED_ELEMENTS:
        case INT8_ELEMENTS:
          __ Strb(value, dst);
          break;
        case EXTERNAL_INT16_ELEMENTS:
        case EXTERNAL_UINT16_ELEMENTS:
        case INT16_ELEMENTS:
        case UINT16_ELEMENTS:
          __ Strh(value, dst);
          break;
        case EXTERNAL_INT32_ELEMENTS:
        case EXTERNAL_UINT32_ELEMENTS:
        case INT32_ELEMENTS:
        case UINT32_ELEMENTS:
          __ Str(value.W(), dst);
          break;
        case FLOAT32_ELEMENTS:
        case FLOAT64_ELEMENTS:
        case INT32x4_ELEMENTS:
        case FLOAT32x4_ELEMENTS:
        case FLOAT64x2_ELEMENTS:
        case EXTERNAL_FLOAT32_ELEMENTS:
        case EXTERNAL_FLOAT64_ELEMENTS:
        case EXTERNAL_INT32x4_ELEMENTS:
        case EXTERNAL_FLOAT32x4_ELEMENTS:
        case EXTERNAL_FLOAT64x2_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 SLOPPY_ARGUMENTS_ELEMENTS:
          UNREACHABLE();
          break;
      }
    }
  }
  
  
  void LCodeGen::DoStoreKeyedFixedDouble(LStoreKeyedFixedDouble* instr) {
    Register elements = ToRegister(instr->elements());
    DoubleRegister value = ToDoubleRegister(instr->value());
    MemOperand mem_op;
  
    if (instr->key()->IsConstantOperand()) {
      int constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
      if (constant_key & 0xf0000000) {
        Abort(kArrayIndexConstantValueTooBig);
      }
      int offset = instr->base_offset() + constant_key * kDoubleSize;
      mem_op = MemOperand(elements, offset);
    } else {
      Register store_base = ToRegister(instr->temp());
      Register key = ToRegister(instr->key());
      bool key_is_tagged = instr->hydrogen()->key()->representation().IsSmi();
      mem_op = PrepareKeyedArrayOperand(store_base, elements, key, key_is_tagged,
                                        instr->hydrogen()->elements_kind(),
                                        instr->hydrogen()->representation(),
                                        instr->base_offset());
    }
  
    if (instr->NeedsCanonicalization()) {
      __ CanonicalizeNaN(double_scratch(), value);
      __ Str(double_scratch(), mem_op);
    } else {
      __ Str(value, mem_op);
    }
  }
  
  
  void LCodeGen::DoStoreKeyedFixed(LStoreKeyedFixed* instr) {
    Register value = ToRegister(instr->value());
    Register elements = ToRegister(instr->elements());
    Register scratch = no_reg;
    Register store_base = no_reg;
    Register key = no_reg;
    MemOperand mem_op;
  
    if (!instr->key()->IsConstantOperand() ||
        instr->hydrogen()->NeedsWriteBarrier()) {
      scratch = ToRegister(instr->temp());
    }
  
    Representation representation = instr->hydrogen()->value()->representation();
    if (instr->key()->IsConstantOperand()) {
      LConstantOperand* const_operand = LConstantOperand::cast(instr->key());
      int offset = instr->base_offset() +
          ToInteger32(const_operand) * kPointerSize;
      store_base = elements;
      if (representation.IsInteger32()) {
        DCHECK(instr->hydrogen()->store_mode() == STORE_TO_INITIALIZED_ENTRY);
        DCHECK(instr->hydrogen()->elements_kind() == FAST_SMI_ELEMENTS);
        STATIC_ASSERT(static_cast<unsigned>(kSmiValueSize) == kWRegSizeInBits);
        STATIC_ASSERT(kSmiTag == 0);
        mem_op = UntagSmiMemOperand(store_base, offset);
      } else {
        mem_op = MemOperand(store_base, offset);
      }
    } else {
      store_base = scratch;
      key = ToRegister(instr->key());
      bool key_is_tagged = instr->hydrogen()->key()->representation().IsSmi();
  
      mem_op = PrepareKeyedArrayOperand(store_base, elements, key, key_is_tagged,
                                        instr->hydrogen()->elements_kind(),
                                        representation, instr->base_offset());
    }
  
    __ Store(value, mem_op, representation);
  
    if (instr->hydrogen()->NeedsWriteBarrier()) {
      DCHECK(representation.IsTagged());
      // This assignment may cause element_addr to alias store_base.
      Register element_addr = scratch;
      SmiCheck check_needed =
          instr->hydrogen()->value()->type().IsHeapObject()
              ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
      // Compute address of modified element and store it into key register.
      __ Add(element_addr, mem_op.base(), mem_op.OffsetAsOperand());
      __ RecordWrite(elements, element_addr, value, GetLinkRegisterState(),
                     kSaveFPRegs, EMIT_REMEMBERED_SET, check_needed,
                     instr->hydrogen()->PointersToHereCheckForValue());
    }
  }
  
  
  void LCodeGen::DoStoreKeyedGeneric(LStoreKeyedGeneric* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->object()).is(StoreDescriptor::ReceiverRegister()));
    DCHECK(ToRegister(instr->key()).is(StoreDescriptor::NameRegister()));
    DCHECK(ToRegister(instr->value()).is(StoreDescriptor::ValueRegister()));
  
    Handle<Code> ic =
        CodeFactory::KeyedStoreIC(isolate(), instr->strict_mode()).code();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
    Representation representation = instr->representation();
  
    Register object = ToRegister(instr->object());
    HObjectAccess access = instr->hydrogen()->access();
    int offset = access.offset();
  
    if (access.IsExternalMemory()) {
      DCHECK(!instr->hydrogen()->has_transition());
      DCHECK(!instr->hydrogen()->NeedsWriteBarrier());
      Register value = ToRegister(instr->value());
      __ Store(value, MemOperand(object, offset), representation);
      return;
    }
  
    __ AssertNotSmi(object);
  
    if (representation.IsDouble()) {
      DCHECK(access.IsInobject());
      DCHECK(!instr->hydrogen()->has_transition());
      DCHECK(!instr->hydrogen()->NeedsWriteBarrier());
      FPRegister value = ToDoubleRegister(instr->value());
      __ Str(value, FieldMemOperand(object, offset));
      return;
    }
  
    Register value = ToRegister(instr->value());
  
    DCHECK(!representation.IsSmi() ||
           !instr->value()->IsConstantOperand() ||
           IsInteger32Constant(LConstantOperand::cast(instr->value())));
  
    if (instr->hydrogen()->has_transition()) {
      Handle<Map> transition = instr->hydrogen()->transition_map();
      AddDeprecationDependency(transition);
      // Store the new map value.
      Register new_map_value = ToRegister(instr->temp0());
      __ Mov(new_map_value, Operand(transition));
      __ Str(new_map_value, FieldMemOperand(object, HeapObject::kMapOffset));
      if (instr->hydrogen()->NeedsWriteBarrierForMap()) {
        // Update the write barrier for the map field.
        __ RecordWriteForMap(object,
                             new_map_value,
                             ToRegister(instr->temp1()),
                             GetLinkRegisterState(),
                             kSaveFPRegs);
      }
    }
  
    // Do the store.
    Register destination;
    if (access.IsInobject()) {
      destination = object;
    } else {
      Register temp0 = ToRegister(instr->temp0());
      __ Ldr(temp0, FieldMemOperand(object, JSObject::kPropertiesOffset));
      destination = temp0;
    }
  
    if (representation.IsSmi() &&
       instr->hydrogen()->value()->representation().IsInteger32()) {
      DCHECK(instr->hydrogen()->store_mode() == STORE_TO_INITIALIZED_ENTRY);
  #ifdef DEBUG
      Register temp0 = ToRegister(instr->temp0());
      __ Ldr(temp0, FieldMemOperand(destination, offset));
      __ AssertSmi(temp0);
      // If destination aliased temp0, restore it to the address calculated
      // earlier.
      if (destination.Is(temp0)) {
        DCHECK(!access.IsInobject());
        __ Ldr(destination, FieldMemOperand(object, JSObject::kPropertiesOffset));
      }
  #endif
      STATIC_ASSERT(static_cast<unsigned>(kSmiValueSize) == kWRegSizeInBits);
      STATIC_ASSERT(kSmiTag == 0);
      __ Store(value, UntagSmiFieldMemOperand(destination, offset),
               Representation::Integer32());
    } else {
      __ Store(value, FieldMemOperand(destination, offset), representation);
    }
    if (instr->hydrogen()->NeedsWriteBarrier()) {
      __ RecordWriteField(destination,
                          offset,
                          value,                        // Clobbered.
                          ToRegister(instr->temp1()),   // Clobbered.
                          GetLinkRegisterState(),
                          kSaveFPRegs,
                          EMIT_REMEMBERED_SET,
                          instr->hydrogen()->SmiCheckForWriteBarrier(),
                          instr->hydrogen()->PointersToHereCheckForValue());
    }
  }
  
  
  void LCodeGen::DoStoreNamedGeneric(LStoreNamedGeneric* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->object()).is(StoreDescriptor::ReceiverRegister()));
    DCHECK(ToRegister(instr->value()).is(StoreDescriptor::ValueRegister()));
  
    __ Mov(StoreDescriptor::NameRegister(), Operand(instr->name()));
    Handle<Code> ic = StoreIC::initialize_stub(isolate(), instr->strict_mode());
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
  }
  
  
  void LCodeGen::DoStringAdd(LStringAdd* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    DCHECK(ToRegister(instr->left()).Is(x1));
    DCHECK(ToRegister(instr->right()).Is(x0));
    StringAddStub stub(isolate(),
                       instr->hydrogen()->flags(),
                       instr->hydrogen()->pretenure_flag());
    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()),
                                      ToRegister32(instr->index()),
                                      ToRegister(instr->result()),
                                      deferred->entry());
    __ Bind(deferred->exit());
  }
  
  
  void LCodeGen::DoDeferredStringCharCodeAt(LStringCharCodeAt* instr) {
    Register string = ToRegister(instr->string());
    Register result = ToRegister(instr->result());
  
    // TODO(3095996): Get rid of this. For now, we need to make the
    // result register contain a valid pointer because it is already
    // contained in the register pointer map.
    __ Mov(result, 0);
  
    PushSafepointRegistersScope scope(this);
    __ Push(string);
    // Push the index as a smi. This is safe because of the checks in
    // DoStringCharCodeAt above.
    Register index = ToRegister(instr->index());
    __ SmiTagAndPush(index);
  
    CallRuntimeFromDeferred(Runtime::kStringCharCodeAtRT, 2, instr,
                            instr->context());
    __ AssertSmi(x0);
    __ SmiUntag(x0);
    __ StoreToSafepointRegisterSlot(x0, 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);
  
    DCHECK(instr->hydrogen()->value()->representation().IsInteger32());
    Register char_code = ToRegister32(instr->char_code());
    Register result = ToRegister(instr->result());
  
    __ Cmp(char_code, String::kMaxOneByteCharCode);
    __ B(hi, deferred->entry());
    __ LoadRoot(result, Heap::kSingleCharacterStringCacheRootIndex);
    __ Add(result, result, FixedArray::kHeaderSize - kHeapObjectTag);
    __ Ldr(result, MemOperand(result, char_code, SXTW, kPointerSizeLog2));
    __ CompareRoot(result, Heap::kUndefinedValueRootIndex);
    __ B(eq, deferred->entry());
    __ Bind(deferred->exit());
  }
  
  
  void LCodeGen::DoDeferredStringCharFromCode(LStringCharFromCode* instr) {
    Register char_code = ToRegister(instr->char_code());
    Register result = ToRegister(instr->result());
  
    // TODO(3095996): Get rid of this. For now, we need to make the
    // result register contain a valid pointer because it is already
    // contained in the register pointer map.
    __ Mov(result, 0);
  
    PushSafepointRegistersScope scope(this);
    __ SmiTagAndPush(char_code);
    CallRuntimeFromDeferred(Runtime::kCharFromCode, 1, instr, instr->context());
    __ StoreToSafepointRegisterSlot(x0, result);
  }
  
  
  void LCodeGen::DoStringCompareAndBranch(LStringCompareAndBranch* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    Token::Value op = instr->op();
  
    Handle<Code> ic = CodeFactory::CompareIC(isolate(), op).code();
    CallCode(ic, RelocInfo::CODE_TARGET, instr);
    InlineSmiCheckInfo::EmitNotInlined(masm());
  
    Condition condition = TokenToCondition(op, false);
  
    EmitCompareAndBranch(instr, condition, x0, 0);
  }
  
  
  void LCodeGen::DoSubI(LSubI* instr) {
    bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
    Register result = ToRegister32(instr->result());
    Register left = ToRegister32(instr->left());
    Operand right = ToShiftedRightOperand32(instr->right(), instr);
  
    if (can_overflow) {
      __ Subs(result, left, right);
      DeoptimizeIf(vs, instr);
    } else {
      __ Sub(result, left, right);
    }
  }
  
  
  void LCodeGen::DoSubS(LSubS* instr) {
    bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
    Register result = ToRegister(instr->result());
    Register left = ToRegister(instr->left());
    Operand right = ToOperand(instr->right());
    if (can_overflow) {
      __ Subs(result, left, right);
      DeoptimizeIf(vs, instr);
    } else {
      __ Sub(result, left, right);
    }
  }
  
  
  void LCodeGen::DoDeferredTaggedToI(LTaggedToI* instr,
                                     LOperand* value,
                                     LOperand* temp1,
                                     LOperand* temp2) {
    Register input = ToRegister(value);
    Register scratch1 = ToRegister(temp1);
    DoubleRegister dbl_scratch1 = double_scratch();
  
    Label done;
  
    if (instr->truncating()) {
      Register output = ToRegister(instr->result());
      Label check_bools;
  
      // If it's not a heap number, jump to undefined check.
      __ JumpIfNotHeapNumber(input, &check_bools);
  
      // A heap number: load value and convert to int32 using truncating function.
      __ TruncateHeapNumberToI(output, input);
      __ B(&done);
  
      __ Bind(&check_bools);
  
      Register true_root = output;
      Register false_root = scratch1;
      __ LoadTrueFalseRoots(true_root, false_root);
      __ Cmp(input, true_root);
      __ Cset(output, eq);
      __ Ccmp(input, false_root, ZFlag, ne);
      __ B(eq, &done);
  
      // Output contains zero, undefined is converted to zero for truncating
      // conversions.
      DeoptimizeIfNotRoot(input, Heap::kUndefinedValueRootIndex, instr);
    } else {
      Register output = ToRegister32(instr->result());
      DoubleRegister dbl_scratch2 = ToDoubleRegister(temp2);
  
      DeoptimizeIfNotHeapNumber(input, instr);
  
      // A heap number: load value and convert to int32 using non-truncating
      // function. If the result is out of range, branch to deoptimize.
      __ Ldr(dbl_scratch1, FieldMemOperand(input, HeapNumber::kValueOffset));
      __ TryRepresentDoubleAsInt32(output, dbl_scratch1, dbl_scratch2);
      DeoptimizeIf(ne, instr, "lost precision or NaN");
  
      if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
        __ Cmp(output, 0);
        __ B(ne, &done);
        __ Fmov(scratch1, dbl_scratch1);
        DeoptimizeIfNegative(scratch1, instr, "minus zero");
      }
    }
    __ 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_, instr_->value(), instr_->temp1(),
                                       instr_->temp2());
      }
  
      virtual LInstruction* instr() { return instr_; }
     private:
      LTaggedToI* instr_;
    };
  
    Register input = ToRegister(instr->value());
    Register output = ToRegister(instr->result());
  
    if (instr->hydrogen()->value()->representation().IsSmi()) {
      __ SmiUntag(output, input);
    } else {
      DeferredTaggedToI* deferred = new(zone()) DeferredTaggedToI(this, instr);
  
      __ JumpIfNotSmi(input, deferred->entry());
      __ SmiUntag(output, input);
      __ Bind(deferred->exit());
    }
  }
  
  
  void LCodeGen::DoThisFunction(LThisFunction* instr) {
    Register result = ToRegister(instr->result());
    __ Ldr(result, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
  }
  
  
  void LCodeGen::DoToFastProperties(LToFastProperties* instr) {
    DCHECK(ToRegister(instr->value()).Is(x0));
    DCHECK(ToRegister(instr->result()).Is(x0));
    __ Push(x0);
    CallRuntime(Runtime::kToFastProperties, 1, instr);
  }
  
  
  void LCodeGen::DoRegExpLiteral(LRegExpLiteral* instr) {
    DCHECK(ToRegister(instr->context()).is(cp));
    Label materialized;
    // Registers will be used as follows:
    // x7 = literals array.
    // x1 = regexp literal.
    // x0 = regexp literal clone.
    // x10-x12 are used as temporaries.
    int literal_offset =
        FixedArray::OffsetOfElementAt(instr->hydrogen()->literal_index());
    __ LoadObject(x7, instr->hydrogen()->literals());
    __ Ldr(x1, FieldMemOperand(x7, literal_offset));
    __ JumpIfNotRoot(x1, Heap::kUndefinedValueRootIndex, &materialized);
  
    // Create regexp literal using runtime function
    // Result will be in x0.
    __ Mov(x12, Operand(Smi::FromInt(instr->hydrogen()->literal_index())));
    __ Mov(x11, Operand(instr->hydrogen()->pattern()));
    __ Mov(x10, Operand(instr->hydrogen()->flags()));
    __ Push(x7, x12, x11, x10);
    CallRuntime(Runtime::kMaterializeRegExpLiteral, 4, instr);
    __ Mov(x1, x0);
  
    __ Bind(&materialized);
    int size = JSRegExp::kSize + JSRegExp::kInObjectFieldCount * kPointerSize;
    Label allocated, runtime_allocate;
  
    __ Allocate(size, x0, x10, x11, &runtime_allocate, TAG_OBJECT);
    __ B(&allocated);
  
    __ Bind(&runtime_allocate);
    __ Mov(x0, Smi::FromInt(size));
    __ Push(x1, x0);
    CallRuntime(Runtime::kAllocateInNewSpace, 1, instr);
    __ Pop(x1);
  
    __ Bind(&allocated);
    // Copy the content into the newly allocated memory.
    __ CopyFields(x0, x1, CPURegList(x10, x11, x12), size / kPointerSize);
  }
  
  
  void LCodeGen::DoTransitionElementsKind(LTransitionElementsKind* instr) {
    Register object = ToRegister(instr->object());
  
    Handle<Map> from_map = instr->original_map();
    Handle<Map> to_map = instr->transitioned_map();
    ElementsKind from_kind = instr->from_kind();
    ElementsKind to_kind = instr->to_kind();
  
    Label not_applicable;
  
    if (IsSimpleMapChangeTransition(from_kind, to_kind)) {
      Register temp1 = ToRegister(instr->temp1());
      Register new_map = ToRegister(instr->temp2());
      __ CheckMap(object, temp1, from_map, &not_applicable, DONT_DO_SMI_CHECK);
      __ Mov(new_map, Operand(to_map));
      __ Str(new_map, FieldMemOperand(object, HeapObject::kMapOffset));
      // Write barrier.
      __ RecordWriteForMap(object, new_map, temp1, GetLinkRegisterState(),
                           kDontSaveFPRegs);
    } else {
      {
        UseScratchRegisterScope temps(masm());
        // Use the temp register only in a restricted scope - the codegen checks
        // that we do not use any register across a call.
        __ CheckMap(object, temps.AcquireX(), from_map, &not_applicable,
                    DONT_DO_SMI_CHECK);
      }
      DCHECK(object.is(x0));
      DCHECK(ToRegister(instr->context()).is(cp));
      PushSafepointRegistersScope scope(this);
      __ Mov(x1, Operand(to_map));
      bool is_js_array = from_map->instance_type() == JS_ARRAY_TYPE;
      TransitionElementsKindStub stub(isolate(), from_kind, to_kind, is_js_array);
      __ CallStub(&stub);
      RecordSafepointWithRegisters(
          instr->pointer_map(), 0, Safepoint::kLazyDeopt);
    }
    __ Bind(&not_applicable);
  }
  
  
  void LCodeGen::DoTrapAllocationMemento(LTrapAllocationMemento* instr) {
    Register object = ToRegister(instr->object());
    Register temp1 = ToRegister(instr->temp1());
    Register temp2 = ToRegister(instr->temp2());
  
    Label no_memento_found;
    __ TestJSArrayForAllocationMemento(object, temp1, temp2, &no_memento_found);
    DeoptimizeIf(eq, instr);
    __ Bind(&no_memento_found);
  }
  
  
  void LCodeGen::DoTruncateDoubleToIntOrSmi(LTruncateDoubleToIntOrSmi* instr) {
    DoubleRegister input = ToDoubleRegister(instr->value());
    Register result = ToRegister(instr->result());
    __ TruncateDoubleToI(result, input);
    if (instr->tag_result()) {
      __ SmiTag(result, result);
    }
  }
  
  
  void LCodeGen::DoTypeof(LTypeof* instr) {
    Register input = ToRegister(instr->value());
    __ Push(input);
    CallRuntime(Runtime::kTypeof, 1, instr);
  }
  
  
  void LCodeGen::DoTypeofIsAndBranch(LTypeofIsAndBranch* instr) {
    Handle<String> type_name = instr->type_literal();
    Label* true_label = instr->TrueLabel(chunk_);
    Label* false_label = instr->FalseLabel(chunk_);
    Register value = ToRegister(instr->value());
  
    Factory* factory = isolate()->factory();
    if (String::Equals(type_name, factory->number_string())) {
      __ JumpIfSmi(value, true_label);
  
      int true_block = instr->TrueDestination(chunk_);
      int false_block = instr->FalseDestination(chunk_);
      int next_block = GetNextEmittedBlock();
  
      if (true_block == false_block) {
        EmitGoto(true_block);
      } else if (true_block == next_block) {
        __ JumpIfNotHeapNumber(value, chunk_->GetAssemblyLabel(false_block));
      } else {
        __ JumpIfHeapNumber(value, chunk_->GetAssemblyLabel(true_block));
        if (false_block != next_block) {
          __ B(chunk_->GetAssemblyLabel(false_block));
        }
      }
  
    } else if (String::Equals(type_name, factory->string_string())) {
      DCHECK((instr->temp1() != NULL) && (instr->temp2() != NULL));
      Register map = ToRegister(instr->temp1());
      Register scratch = ToRegister(instr->temp2());
  
      __ JumpIfSmi(value, false_label);
      __ JumpIfObjectType(
          value, map, scratch, FIRST_NONSTRING_TYPE, false_label, ge);
      __ Ldrb(scratch, FieldMemOperand(map, Map::kBitFieldOffset));
      EmitTestAndBranch(instr, eq, scratch, 1 << Map::kIsUndetectable);
  
    } else if (String::Equals(type_name, factory->symbol_string())) {
      DCHECK((instr->temp1() != NULL) && (instr->temp2() != NULL));
      Register map = ToRegister(instr->temp1());
      Register scratch = ToRegister(instr->temp2());
  
      __ JumpIfSmi(value, false_label);
      __ CompareObjectType(value, map, scratch, SYMBOL_TYPE);
      EmitBranch(instr, eq);
  
    } else if (String::Equals(type_name, factory->boolean_string())) {
      __ JumpIfRoot(value, Heap::kTrueValueRootIndex, true_label);
      __ CompareRoot(value, Heap::kFalseValueRootIndex);
      EmitBranch(instr, eq);
  
    } else if (String::Equals(type_name, factory->undefined_string())) {
      DCHECK(instr->temp1() != NULL);
      Register scratch = ToRegister(instr->temp1());
  
      __ JumpIfRoot(value, Heap::kUndefinedValueRootIndex, true_label);
      __ JumpIfSmi(value, false_label);
      // Check for undetectable objects and jump to the true branch in this case.
      __ Ldr(scratch, FieldMemOperand(value, HeapObject::kMapOffset));
      __ Ldrb(scratch, FieldMemOperand(scratch, Map::kBitFieldOffset));
      EmitTestAndBranch(instr, ne, scratch, 1 << Map::kIsUndetectable);
  
    } else if (String::Equals(type_name, factory->function_string())) {
      STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
      DCHECK(instr->temp1() != NULL);
      Register type = ToRegister(instr->temp1());
  
      __ JumpIfSmi(value, false_label);
      __ JumpIfObjectType(value, type, type, JS_FUNCTION_TYPE, true_label);
      // HeapObject's type has been loaded into type register by JumpIfObjectType.
      EmitCompareAndBranch(instr, eq, type, JS_FUNCTION_PROXY_TYPE);
  
    } else if (String::Equals(type_name, factory->object_string())) {
      DCHECK((instr->temp1() != NULL) && (instr->temp2() != NULL));
      Register map = ToRegister(instr->temp1());
      Register scratch = ToRegister(instr->temp2());
  
      __ JumpIfSmi(value, false_label);
      __ JumpIfRoot(value, Heap::kNullValueRootIndex, true_label);
      __ JumpIfObjectType(value, map, scratch,
                          FIRST_NONCALLABLE_SPEC_OBJECT_TYPE, false_label, lt);
      __ CompareInstanceType(map, scratch, LAST_NONCALLABLE_SPEC_OBJECT_TYPE);
      __ B(gt, false_label);
      // Check for undetectable objects => false.
      __ Ldrb(scratch, FieldMemOperand(map, Map::kBitFieldOffset));
      EmitTestAndBranch(instr, eq, scratch, 1 << Map::kIsUndetectable);
  
    } else {
      __ B(false_label);
    }
  }
  
  
  void LCodeGen::DoUint32ToDouble(LUint32ToDouble* instr) {
    __ Ucvtf(ToDoubleRegister(instr->result()), ToRegister32(instr->value()));
  }
  
  
  void LCodeGen::DoCheckMapValue(LCheckMapValue* instr) {
    Register object = ToRegister(instr->value());
    Register map = ToRegister(instr->map());
    Register temp = ToRegister(instr->temp());
    __ Ldr(temp, FieldMemOperand(object, HeapObject::kMapOffset));
    __ Cmp(map, temp);
    DeoptimizeIf(ne, instr);
  }
  
  
  void LCodeGen::DoWrapReceiver(LWrapReceiver* instr) {
    Register receiver = ToRegister(instr->receiver());
    Register function = ToRegister(instr->function());
    Register result = ToRegister(instr->result());
  
    // 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, done, copy_receiver;
  
    if (!instr->hydrogen()->known_function()) {
      __ Ldr(result, FieldMemOperand(function,
                                     JSFunction::kSharedFunctionInfoOffset));
  
      // CompilerHints is an int32 field. See objects.h.
      __ Ldr(result.W(),
             FieldMemOperand(result, SharedFunctionInfo::kCompilerHintsOffset));
  
      // Do not transform the receiver to object for strict mode functions.
      __ Tbnz(result, SharedFunctionInfo::kStrictModeFunction, &copy_receiver);
  
      // Do not transform the receiver to object for builtins.
      __ Tbnz(result, SharedFunctionInfo::kNative, &copy_receiver);
    }
  
    // Normal function. Replace undefined or null with global receiver.
    __ JumpIfRoot(receiver, Heap::kNullValueRootIndex, &global_object);
    __ JumpIfRoot(receiver, Heap::kUndefinedValueRootIndex, &global_object);
  
    // Deoptimize if the receiver is not a JS object.
    DeoptimizeIfSmi(receiver, instr);
    __ CompareObjectType(receiver, result, result, FIRST_SPEC_OBJECT_TYPE);
    __ B(ge, &copy_receiver);
    Deoptimize(instr);
  
    __ Bind(&global_object);
    __ Ldr(result, FieldMemOperand(function, JSFunction::kContextOffset));
    __ Ldr(result, ContextMemOperand(result, Context::GLOBAL_OBJECT_INDEX));
    __ Ldr(result, FieldMemOperand(result, GlobalObject::kGlobalProxyOffset));
    __ B(&done);
  
    __ Bind(&copy_receiver);
    __ Mov(result, receiver);
    __ Bind(&done);
  }
  
  
  void LCodeGen::DoDeferredLoadMutableDouble(LLoadFieldByIndex* instr,
                                             Register result,
                                             Register object,
                                             Register index) {
    PushSafepointRegistersScope scope(this);
    __ Push(object);
    __ Push(index);
    __ Mov(cp, 0);
    __ CallRuntimeSaveDoubles(Runtime::kLoadMutableDouble);
    RecordSafepointWithRegisters(
        instr->pointer_map(), 2, Safepoint::kNoLazyDeopt);
    __ StoreToSafepointRegisterSlot(x0, result);
  }
  
  
  void LCodeGen::DoLoadFieldByIndex(LLoadFieldByIndex* instr) {
    class DeferredLoadMutableDouble FINAL : public LDeferredCode {
     public:
      DeferredLoadMutableDouble(LCodeGen* codegen,
                                LLoadFieldByIndex* instr,
                                Register result,
                                Register object,
                                Register index)
          : LDeferredCode(codegen),
            instr_(instr),
            result_(result),
            object_(object),
            index_(index) {
      }
      virtual void Generate() OVERRIDE {
        codegen()->DoDeferredLoadMutableDouble(instr_, result_, object_, index_);
      }
      virtual LInstruction* instr() OVERRIDE { return instr_; }
     private:
      LLoadFieldByIndex* instr_;
      Register result_;
      Register object_;
      Register index_;
    };
    Register object = ToRegister(instr->object());
    Register index = ToRegister(instr->index());
    Register result = ToRegister(instr->result());
  
    __ AssertSmi(index);
  
    DeferredLoadMutableDouble* deferred;
    deferred = new(zone()) DeferredLoadMutableDouble(
        this, instr, result, object, index);
  
    Label out_of_object, done;
  
    __ TestAndBranchIfAnySet(
        index, reinterpret_cast<uint64_t>(Smi::FromInt(1)), deferred->entry());
    __ Mov(index, Operand(index, ASR, 1));
  
    __ Cmp(index, Smi::FromInt(0));
    __ B(lt, &out_of_object);
  
    STATIC_ASSERT(kPointerSizeLog2 > kSmiTagSize);
    __ Add(result, object, Operand::UntagSmiAndScale(index, kPointerSizeLog2));
    __ Ldr(result, FieldMemOperand(result, JSObject::kHeaderSize));
  
    __ B(&done);
  
    __ Bind(&out_of_object);
    __ Ldr(result, FieldMemOperand(object, JSObject::kPropertiesOffset));
    // Index is equal to negated out of object property index plus 1.
    __ Sub(result, result, Operand::UntagSmiAndScale(index, kPointerSizeLog2));
    __ Ldr(result, FieldMemOperand(result,
                                   FixedArray::kHeaderSize - kPointerSize));
    __ Bind(deferred->exit());
    __ Bind(&done);
  }
  
  
  void LCodeGen::DoStoreFrameContext(LStoreFrameContext* instr) {
    Register context = ToRegister(instr->context());
    __ Str(context, MemOperand(fp, StandardFrameConstants::kContextOffset));
  }
  
  
  void LCodeGen::DoAllocateBlockContext(LAllocateBlockContext* instr) {
    Handle<ScopeInfo> scope_info = instr->scope_info();
    __ Push(scope_info);
    __ Push(ToRegister(instr->function()));
    CallRuntime(Runtime::kPushBlockContext, 2, instr);
    RecordSafepoint(Safepoint::kNoLazyDeopt);
  }
  
  
  
  } }  // namespace v8::internal
  